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Pneumatics Basic level

Workbook TP 101

With CD-ROM

-MM1

-BG1

-PG1

-PG2

-RZ1

1

1

2 -QM1

2

4

2

14

-KH1 1

1

12

5 2

1

3

1

3

-SJ1

2

-RZ2

-BG1

2

1

3

1

-SJ2

2

3

2

1

3

Festo Didactic 541088 en

Order no.: Revision level: Authors: Editor: Graphics: Layout:

541088 04/2016 Wolfgang Haring, Michel Metzger, Ralph-Christoph Weber Frank Ebel Doris Schwarzenberger 06/2016, Frank Ebel

© Festo Didactic SE, Rechbergstr. 3, 73770 Denkendorf, Germany, 2016 All rights reserved. +49 711 3467-0 +49 711 34754-88500

www.festo-didactic.com [email protected]

The purchaser shall receive a single right of use that is non-exclusive, non-time-limited and limited geographically to the purchaser’s site/location as follows. • The purchaser shall be entitled to use the contents of the documentation to train his staff at the purchaser’s location and shall also be entitled to use parts of the contents of the documentation to create his own training documentation for the training of his staff at the purchaser’s location with acknowledgement of source, and to make copies for this purpose. In the case of schools/technical colleges and training centers, the right of use shall also include use by school pupils, college students and trainees at the purchaser’s location for teaching purposes. • The right of use shall in all cases exclude the right to publish any content or make it available for use on intranet, Internet and LMS platforms and databases such as Moodle, which allow access by a wide variety of users, including those outside of the purchaser’s location. • Entitlement to other rights relating to duplication, copies, adaptations, translations, microfilming and transfer to, as well as storage and processing in electronic systems, either in whole or in part, shall require the prior consent of Festo Didactic.

Note Wherever teachers, trainees etc. are referred to in the masculine form in this manual, the feminine form is, of course, also implied. The use of a single gender form is not intended as gender-specific discrimination, but simply to aid readability and comprehension of the document and the formulations used.

Contents Intended use_____________________________________________________________________________ V Preface _________________________________________________________________________________ VI Introduction _____________________________________________________________________________ IX Work and safety instructions _________________________________________________________________X Pneumatics training package (TP 100) _______________________________________________________ XIII Training aims for the basic level (TP 101) _____________________________________________________ XIV Allocation of learning objectives to exercises__________________________________________________ XV Equipment set for the basic level (TP 101) ___________________________________________________ XVII Allocation of components to exercises _______________________________________________________ XX Notes for the teacher/instructor ____________________________________________________________ XXI Structure of the exercises ________________________________________________________________ XXII Reference designations of the devices ______________________________________________________ XXIII Contents of the CD-ROM _________________________________________________________________ XXIII

Exercises and solutions Exercise 1: Pressing cheeses........................................................................................................................... 3 Exercise 2: Run-on brake on a drive shaft ..................................................................................................... 11 Exercise 3: Clamping boards on a saw machine ............................................................................................ 17 Exercise 4: Loading packages ....................................................................................................................... 23 Exercise 5: Stopping milk bottles .................................................................................................................. 33 Exercise 6: Opening and closing a supply pipe ............................................................................................. 39 Exercise 7: Shutting off using a quick power lockout .................................................................................... 47 Exercise 8: Actuating a shut-off device ......................................................................................................... 53 Exercise 9: Expanding a control system to enable cheese pressing .............................................................. 61 Exercise 10: Clamping a workpiece ............................................................................................................... 69 Exercise 11: Loading mesh baskets .............................................................................................................. 77 Exercise 12: Actuating a sliding door ............................................................................................................ 83 Exercise 13: Feeding in wooden boards ........................................................................................................ 91 Exercise 14: Pressing drinks cans ................................................................................................................. 97 Exercise 15: Stamping valve housings ........................................................................................................ 105 Exercise 16: Mounting locking clips ............................................................................................................ 113 Exercise 17: Labeling paint buckets ............................................................................................................ 121 Exercise 18: Cleaning workpieces ............................................................................................................... 129 Exercise 19: Pressing product labels into place .......................................................................................... 137

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Contents

Exercises and worksheets Exercise 1: Pressing cheeses........................................................................................................................... 3 Exercise 2: Run-on brake on a drive shaft ..................................................................................................... 11 Exercise 3: Clamping boards on a saw machine ............................................................................................ 17 Exercise 4: Loading packages ....................................................................................................................... 23 Exercise 5: Stopping milk bottles .................................................................................................................. 33 Exercise 6: Opening and closing a supply pipe ............................................................................................. 39 Exercise 7: Shutting off using a quick power lockout .................................................................................... 47 Exercise 8: Actuating a shut-off device ......................................................................................................... 53 Exercise 9: Expanding a control system to enable cheese pressing .............................................................. 61 Exercise 10: Clamping a workpiece ............................................................................................................... 69 Exercise 11: Loading mesh baskets .............................................................................................................. 77 Exercise 12: Actuating a sliding door ............................................................................................................ 83 Exercise 13: Feeding in wooden boards ........................................................................................................ 91 Exercise 14: Pressing drinks cans ................................................................................................................. 97 Exercise 15: Stamping valve housings ........................................................................................................ 105 Exercise 16: Mounting locking clips ............................................................................................................ 113 Exercise 17: Labeling paint buckets ............................................................................................................ 121 Exercise 18: Cleaning workpieces ............................................................................................................... 129 Exercise 19: Pressing product labels into place .......................................................................................... 137

IV

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Intended use The training package for basic level pneumatics may only be used: • For its intended purpose in teaching and training applications • When its safety functions are in perfect condition The components included in the training package are designed in accordance with the current state of the art and recognized safety rules. However, life and limb of the user and third parties may be endangered and the components may be impaired if it is used incorrectly. The Festo Didactic learning system has been developed and produced exclusively for basic and further training in the field of automation technology. The training company and/or instructors must ensure that all trainees observe the safety precautions described in this workbook. Festo Didactic hereby excludes any and all liability for damages suffered by trainees, the training company and/or any third parties, which occur during use of the equipment sets in situations that serve any purpose other than training and/or vocational education, unless such damages have been caused by Festo Didactic due to malicious intent or gross negligence.

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Preface Festo Didactic’s learning system for automation and technology is geared towards various educational backgrounds and vocational requirements. The learning system is therefore broken down as follows: • Technology-oriented training packages • Mechatronics and factory automation • Process automation and closed-loop control technology • Mobile robotics • Hybrid learning factories The learning system for automation and technology is continuously updated and expanded in accordance with developments in the field of education, as well as actual professional practice. The training packages deal with various technologies including pneumatics, electropneumatics, closed-loop pneumatics, hydraulics, electrohydraulics, proportional hydraulics, closed-loop hydraulics, mobile hydraulics, programmable logic controllers, sensor technology, electrical engineering, electronics and electric drives.

The modular design of the learning system allows for applications that go above and beyond the limitations of the individual training packages. For example, PLC control of pneumatic, hydraulic and electric drives is possible.

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All training packages feature the following elements: • Hardware • Media • Seminars Hardware The hardware in the training packages is comprised of industrial components and systems that are specially designed for training purposes. The components contained in the training packages are specifically designed and selected for the projects in the accompanying media. Media The media provided for the individual topics consist of a mixture of teachware and software. The teachware includes: • Technical literature and textbooks (standard works for teaching basic knowledge) • Workbooks (practical exercises with supplementary instructions and sample solutions) • Dictionaries, manuals and technical books (for technical information on groups of topics for further exploration) • Transparency sets and videos (for easy-to-follow, dynamic instruction) • Posters (for presenting information in a clear-cut way) The following software programs are available: • Digital training programs (learning content specifically designed for virtual training) • Simulation software • Visualization software • Software for acquiring measurement data • Project engineering and design engineering software • Programming software for programmable logic controllers The teaching and learning media are available in several languages. They are intended for use in classroom instruction, but are also suitable for self-study. Workbook license types We offer the following three license types for workbooks: • Home use license For personal use. You order the workbook online as a PDF file. All of the workbook’s pages are watermarked. You can save the PDF file to your PC, print it out and edit it. The multimedia CD-ROM is not included. • Campus license This is the standard option for commercial use. You order a printed version of the workbook with a multimedia CD-ROM in the language of your choice. The files included on the multimedia CD-ROM can be saved to your PC, printed out and edited.

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•

Enterprise license For large companies and educational institutions with multiple locations. You order either: – A printed version of the workbook in the language of your choice including a multimedia CD-ROM with multilingual content or – A multimedia CD-ROM with multilingual content. The files included on the multimedia CD-ROM can be saved to your PC, printed out and edited.

Note The full rights of use are in compliance with the stipulations included in the legal notice of the purchased workbook.

Do you have tips or suggestions for improving this workbook? If so, please inform us by e-mail at [email protected]. The authors and Festo Didactic look forward to your comments.

Seminars A wide range of seminars covering the contents of the training packages round off the system for basic and further training.

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Introduction This workbook is part of the learning system for automation technology from Festo Didactic. The system provides a solid basis for practice-oriented basic and further training. Training package TP 100 contains only purely pneumatic control systems. The TP 101 basic level is suitable for fundamental training in the field of pneumatic control technology. It provides an understanding of basic physical principles of pneumatics, as well as the function and use of pneumatic components. Simple pneumatic control systems can be set up using the equipment set. The TP 102 advanced level is targeted at further training in the field of pneumatic control technology. The equipment set can be used to build extensive combinational circuits with input and output signal connections, as well as control systems with sequencer modules. Technical prerequisites for setting up the control systems include: • A Learnline or Learntop-S workstation equipped with a Festo Didactic profile plate. The profile plate has 14 parallel T-slots at 50 mm intervals. • A portable, sound-insulated compressor (230 V, max. 800 kPa = 8 bar) is used to supply compressed air.

The working pressure should not exceed p =600 kPa (6 bar).

Ideal operating safety can be achieved by operating the control system at a working pressure of p = 500 kPa (5 bar) without oil. The complete control systems for all 19 exercises are built using the TP 101 basic level equipment set. The theoretical fundamentals for understanding the exercises listed in this workbook are included in the textbook entitled: • Fundamentals of pneumatics and electropneumatics Data sheets for the individual components are also available (cylinders, valves, measuring devices, etc.).

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Work and safety instructions

General • Trainees should only work with the circuits under the supervision of an instructor. • Electrical devices (e.g. power supply units, compressors and hydraulic units) may only be operated in training rooms that are equipped with residual current devices (RCDs). • Observe the specifications included in the technical data for the individual components, and in particular all safety instructions! • Care must be taken to avoid malfunctions that may impair safety. • Wear your personal protective equipment (safety goggles, safety shoes) when working on circuits. Mechanical safety • Switch off the power supply! – Switch off working and control power before working on the circuit. – Only reach into the setup when it is at a complete standstill. – Be aware of the potential overtravel times for the drives. • Mount all of the components on the profile plate securely. • Make sure that limit valves are not actuated from the front. • Risk of injury during troubleshooting! Use a tool such as a screwdriver to actuate the limit valves. • Set all components up in a way that makes it easy to activate the switches and disconnectors. • Follow the instructions regarding positioning of the components. Electrical safety • Disconnect from all sources of electrical power! – Switch off the power supply before working on the circuit. – Please note that electrical energy may be stored in individual components. Further information on this issue is available in the data sheets and operating instructions included with the components. • Use protective extra-low voltage only: max. 24 V DC. • Establishing and disconnecting electrical connections – Electrical connections may only be established in the absence of voltage. – Electrical connections may only be disconnected in the absence of voltage.

X

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• • • • •

Always use connecting cables with safety plugs for electrical connections. When laying connecting cables, make sure they are not kinked or pinched. Do not lay cables over hot surfaces. – Hot surfaces are marked with a corresponding warning symbol. Make sure that connecting cables are not subjected to continuous tensile loads. Always pull on the safety plug when disconnecting connecting cables; never pull the cable.

Pneumatic safety • Depressurize the system! – Switch off the compressed air supply before working on the circuit. – Check the system with pressure gauges to make sure that the entire circuit is fully depressurized. – Please note that energy may be stored in air reservoirs. Further information on this issue is available in the data sheets and operating instructions included with the components. • Do not exceed the maximum permissible pressure of 600 kPa (6 bar). • Do not switch on the compressed air until all tubing connections have been established and secured. • Do not disconnect tubing while under pressure. • Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. • Risk of accident due to advancing cylinders! – Always position pneumatic cylinders so that the piston rod’s working space is unobstructed over the entire stroke range. – Make sure that the piston rod cannot collide with any rigid components of the setup. • Risk of accident due to tubing slipping off! – Use the shortest possible tubing connections. – If tubing slips off: Switch off the compressed air supply immediately. • Pneumatic circuit setup: Connect the devices using plastic tubing with an outside diameter of 4 or 6 mm. Push the tubing into the push-in connector as far as it will go. • Switch the compressed air supply off before dismantling the circuit. • Dismantling the pneumatic circuit Press the blue release ring down so that the tube can be pulled out.

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•

Noise due to escaping compressed air – Noise caused by escaping compressed air may damage your hearing. Reduce the noise by using mufflers, or wear hearing protection if the noise cannot be avoided. – All of the exhaust ports for the components included in the equipment set are equipped with mufflers. Do not remove these mufflers.

Mounting technology The mounting boards for the devices are equipped with mounting variant A, B, C or D: • Variant A, snap-in system Lightweight devices that cannot be subjected to loads (e.g. directional control valves). Simply clip the devices into the slots on the profile plate. Release the devices by turning the blue lever. • Variant B, rotary system Devices with medium load capacity (e.g. drives). These devices are clamped to the profile plate with Thead bolts. The blue knurled nut is used for clamping and loosening. • Variant C, screw system For devices that will be subject to heavy loads and that will rarely need to be removed from the profile plate (e.g. on-off valve with filter regulating valve). The devices are secured with socket head screws and T-head nuts. • Variant D, plug-in system Lightweight devices with lock pins that cannot be subjected to loads (e.g. indicator units). These are secured using plug-in adapters. Necessary accessories A stopwatch is required to assess the constructed circuits. The stopwatch is used for the following tasks: • To ensure that the advancing and retracting times of the cylinders in one-way flow control valves comply with the specifications • To set pneumatic timers

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Pneumatics training package (TP 100) The TP 100 training package consists of a multitude of individual training materials and seminars. The subject matter of this package is strictly pneumatic control systems. Individual elements included in training package TP 100 may also be included in other packages. Important TP 100 components • Permanent workstation with Festo Didactic profile plate • Equipment set or individual components (e.g. cylinders, directional control valves, preset counters, stepper modules, logic components, pneumatic proximity sensors) • Optional training aids (e.g. optical displays, 5/3-way valve, pulling/pushing load) • Complete set of laboratory equipment Media The teachware for the TP 100 training package consists of a textbook and workbooks. The textbook provides basic physical and technical knowledge regarding pneumatics and electropneumatics. The workbooks include exercise sheets for each exercise, the solutions to each individual worksheet and a CD-ROM. A set of ready-to-use exercise sheets and worksheets is included in each workbook for all of the exercises. Data sheets for the hardware components are supplied with the equipment set. Media Text book

Fundamentals of pneumatics and electropneumatics

Workbooks

Pneumatics, Basic level (TP 101) Pneumatics, Advanced level (TP 102)

Optional teachware

Basic pneumatic control systems – practical knowledge Simulation software FluidSIM® Pneumatics WBT Pneumatics Set of cutaway models with storage case

Available software for use in combination with training package TP 100 includes FluidSIM® P and the Pneumatics digital training program. FluidSIM® P aids with the preparation of the lessons. Pneumatic control systems can be set up and simulated. The Pneumatics digital training program provides knowledge regarding the fundamentals of pneumatic control systems. With the help of examples based on actual industrial practice, learners work through the fundamentals of pneumatics and become familiar with components used in pneumatic systems. Further training materials can be found in our catalogs and on the Internet. The learning system for automation and technology is continuously updated and expanded. The transparency sets, videos, CDROMs, DVDs and textbooks are available in several languages.

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Training aims for the basic level (TP 101)

• • • • • • • • •

• • • • • • • •

Circuits Be able to recognize and sketch the various types of actuation used for directional control valves. Be able to explain and set up direct actuation. Be able to analyze and evaluate circuits. Be able to explain and set up indirect actuation. Become familiar with the difference between a signaling element and a control element. Be able to distinguish between flow control methods and use them in accordance with specifications. Become familiar with a way of storing signals in pneumatic control systems. Become familiar with the logic operations AND/OR/NOT and be able implement them. Be able to explain and set up latching circuits. Become familiar with a way of sensing the end positions of cylinders. Be able to combine logic operations. Be able to distinguish between 5/2-way valves, and select and use them in accordance with specifications. Be able to develop existing circuits further. Be able to set up pressure-dependent control systems. Be able to analyze existing circuits and optimize them in accordance with specifications. Be able to set up circuits with oscillating movements. Be able to use pneumatic timers in accordance with parameters. Be able to set up time-dependent control systems. Be able to create the GRAFCET for a process. Be able to analyze and set up circuits with two cylinders.

• •

Measurements, settings and calculations Be able to measure the pressure in pneumatic control systems. Be able to set the advancing and retracting speeds of cylinders.

• • • • • • • • • • • •

XIV

Components Become familiar with the setup and function of a single-acting cylinder. Become familiar with the setup and function of a double-acting cylinder. Become familiar with the setup and function of a 3/2-way valve. Become familiar with the setup and function of a 5/2-way valve. Become familiar with the function of a pneumatically activated 5/2-way valve. Become familiar with the setup and function of a magnetic proximity sensor. Become familiar with the setup and function of a pressure sequence valve. Become familiar with the setup and function of a pressure regulator. Become familiar with the setup and function of a pneumatic timer.

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Allocation of learning objectives to exercises Exercise

1

2

3

and function of a single-acting cylinder.

•

•

•

Become familiar with the setup and function of a 3/2-way valve.

•

•

•

•

•

•

•

•

•

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

Training aims Become familiar with the setup

Be able to recognize and sketch the various types of actuation used for directional control valves. Be able to explain and set up direct actuation. Be able to analyze and evaluate circuits.

•

•

•

Become familiar with the setup and function of a double-acting cylinder.

•

Become familiar with the setup

•

and function of a 5/2-way valve. Be able to explain and set up indirect actuation.

• •

•

Become familiar with the difference between a signaling element and a control element. Be able to measure the pressure in pneumatic control systems.

• •

Be able to distinguish between flow control methods and use them in accordance with specifications. Be able to set the advancing and retracting speeds of cylinders.

•

•

•

•

Become familiar with a way of storing signals in pneumatic control systems.

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•

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Exercise

1

2

3

4

5

6

7

8

9

10

11

12

13

•

•

•

•

•

•

•

14

15

16

17

•

•

•

18

19

Learning objectives Become familiar with the logic operations AND/OR/NOT and be able implement them. Be able to explain and set up latching circuits.

•

Become familiar with a way of

•

sensing the end positions of cylinders. Be able to combine logic operations. Become familiar with the setup

•

and function of a magnetic proximity sensor. Be able to distinguish between 5/2-way valves, and select and

•

use them in accordance with specifications. Be able to develop existing circuits further.

•

•

Become familiar with the setup and function of a pressure sequence valve.

•

Be able to set up pressure-

•

dependent control systems. Become familiar with the setup and function of a pressure regulator.

•

Become familiar with the setup and function of a pneumatic timer.

•

Be able to create the GRAFCET

•

for a process. Be able to set up circuits with oscillating movements.

•

Be able to use pneumatic timers in accordance with parameters.

•

Be able to analyze and set up circuits with two cylinders.

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Equipment set for the basic level (TP 101) This equipment set has been put together for basic training in the field of pneumatic control technology. It includes all of the elements necessary for achieving the specified learning objectives, and can be supplemented with any other equipment sets. A profile plate and a source of compressed air are also required in order to set up functional control systems.

Equipment set for the basic level (TP 101), order no. 540710 Quantity

Designation

Order no.

2

3/2-way valve with pushbutton actuator, normally closed

152860

1

3/2-way valve with pushbutton actuator, normally open

152861

1

3/2-way valve with selector switch, normally closed

152863

2

3/2-way roller-actuated valve, normally closed

152866

1

3/2-way valve, pneumatically actuated, one side

576302

1

5/2-way valve with selector switch

152862

1

5/2-way valve, pneumatically actuated, one side

576307

3

5/2-way bistable valve, pneumatically actuated, both sides

576303

1

Single-acting cylinder

152887

1

Double-acting cylinder

152888

2

Proximity sensor, pneumatic, with cylinder attachment

2764815

2

One-way flow control valve

193967

1

Quick-exhaust valve

539772

2

Pressure gauge

152865

1

Pressure regulator with gauge

539756

1

Pressure sequence valve

152884

1

OR valve

539771

2

AND valve

539770

1

Pneumatic timer, normally closed

540694

1

On-off valve with filter regulating valve

540691

1

Distributor block

152896

10

Push-in sleeve

153251

10

T-plug connector

153128

2

Plastic tubing, 4 x 0.75, silver, 10 m

151496

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Equipment set symbols Component 3/2-way valve with

Symbol

Component

Symbol

Single-acting cylinder

pushbutton actuator, normally closed

3/2-way valve with

Double-acting cylinder

pushbutton actuator, normally open

3/2-way valve with selector

Pneumatic proximity

switch

sensor

3/2-way roller-actuated

One-way flow control valve

valve, normally closed

3/2-way valve,

Quick-exhaust valve

pneumatically actuated, one side

XVIII

5/2-way valve with selector switch

Pressure gauge

OR valve

Pressure regulator with gauge

AND valve

Pneumatic timer, normally closed

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Component

Symbol

5/2-way valve, pneumatically actuated, one side

5/2-way bistable valve, pneumatically actuated, both sides

Pressure sequence valve

On-off valve with filter regulating valve

Distributor block

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Allocation of components to exercises Exercise

1

2

3

1

1

1

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

Component Cylinder, single-acting Cylinder, double-acting

1 1

1

One-way flow control valve

1

1

1

1

1

1

1

1

1

1

1

1

1

2

1

1

2

2

2

2

2

2

2

1

2

2

1

1

1

1

2

2

1

1

1

1

Quick-exhaust valve

1

Pressure gauge 3/2-way valve with pushbutton actuator, normally closed

1

2

1

1

3/2-way valve with pushbutton

1

2

2 2

2

1

1 1

2

1

2

2

1

1

1

actuator, normally open 3/2-way valve with selector switch, normally closed

1

1

1

3/2-way roller-actuated valve, normally closed

1

1

Pneumatic proximity sensor

2

3/2-way pneumatic valve

2

2

1

1

2

2

1

3/2-way pneumatic bistable valve 5/2-way valve with selector switch

1

5/2-way pneumatic valve

1

1

1

1

5/2-way pneumatic bistable valve

1

1

1

OR valve

1 1

AND valve

1 1

1 2

1

1

1

1

1 2

1

1

1

2

Pressure sequence valve

1

1

1

Pressure regulator with gauge

1

2

1

Pneumatic timer, normally closed

1

2 1

1 1

1

Distributor block

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

On-off valve with filter regulating

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

valve

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Notes for the teacher/instructor Training aims The basic learning objectives for the book of exercises are the systematic drafting of circuit diagrams, as well as the practical setup of the control system on the profile plate. This direct interaction involving both theory and practice ensures faster progress and longer-lasting learning. The more specific training aims are documented in the matrix. Concrete, individual training aims are assigned to each exercise. Required time The time required for working through the exercises depends on the student’s previous knowledge of the subject matter. For a skilled laborer in the field of metalworking or electrical installation, the time required is approx. 2 weeks. For a technician or engineer, it is approx. 1 week. Equipment set components The textbook, workbook and equipment set are designed to be used together. All 19 exercises can be completed using the components from one TP 101 equipment set. Each exercise can be set up on a profile plate with a width of at least 700 mm. Standards The following standards apply to this workbook: ISO 1219-1: Fluid power systems and components – Graphic symbols and circuit diagrams – Symbols EN 81346-2: Industrial systems, installations and equipment and industrial products – Structuring principles and reference designations Identification of solutions Solutions and additions in graphics or diagrams appear in red. Identification in the worksheets Texts that require completion are identified with blank lines or gray table cells. Graphics and diagrams that require completion include a grid. Training notes This section provides additional information regarding the individual components and the completed control systems. These notes are not included in the worksheets.

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Solutions The solutions provided in this workbook are the results of test measurements. The results of your measurements may deviate from these. Fields of learning The allocation of the field of learning offered by vocational schools to the subject matter of “fluid power” is provided below for selected vocational apprenticeships. Vocational apprenticeship

Topic

Electronics engineer for automation technology

Analyzing and adapting control systems

Systems implementation and safety testing Industrial mechanic

Installing and commissioning control systems

Mechatronics technician

Examination of the flow of energy and information in electrical, pneumatic and hydraulic assemblies Implementation of mechatronic subsystems

Structure of the exercises All 19 exercises have the same structure and are broken down into: • Title • Training aims • Description of the problem • Layout • Parameters • Work assignments • Work aids • Worksheets The workbook includes the solution for each of the worksheets for all 19 exercises.

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Reference designations of the devices The reference designations in the circuit diagrams are in compliance with EN 81346-2:2010-05, Industrial systems, installations and equipment and industrial products – Structuring principles and reference designations – Part 2: Classification of objects and codes for classes. The product-related aspect of the devices is taken into consideration, which is why all reference designations begin with a dash. Codes are assigned depending on the device. If several devices within a circuit have the same code, consecutive numbers are assigned to them as well. Cylinders: Valves: Sensors: Signal inputs: Accessories:

-MM1, -MM2... -QM1, -QM2, -KH1, -KH2, -RM1, -RZ1, … -BG1, -BG2, -BF1, -BP1, ... -SF1, -SF2, -SJ1, -SJ2, ... -AZ1, -AZ2, -XM1, -XM2, -PG1, …

Contents of the CD-ROM For the Campus and Enterprise license types, a multimedia CD-ROM is supplied with the workbook. The entire workbook is included on the CD-ROM as a PDF file. The CD-ROM also provides you with additional media. The CD-ROM includes the following folders: • Operating instructions • Images • FluidSIM® circuit diagrams • Presentations • Videos Operating instructions Operating instructions are provided for various devices included in the training package. These instructions are helpful when using and commissioning the devices. Images Photos and graphics of components and industrial applications are provided. These can be used to illustrate individual tasks or to supplement project presentations. FluidSIM® circuit diagrams The FluidSIM® circuit diagrams for all of the exercises included in the training package are contained in this directory.

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Presentations This directory contains short presentations for the devices included in the training package. These can be used to create project presentations, for example. Videos Finally, there are several short videos of industrial applications in their actual environments.

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© Festo Didactic 541088

Contents Exercises and solutions Exercise 1: Pressing cheeses........................................................................................................................... 3 Exercise 2: Run-on brake on a drive shaft ..................................................................................................... 11 Exercise 3: Clamping boards on a saw machine ............................................................................................ 17 Exercise 4: Loading packages ....................................................................................................................... 23 Exercise 5: Stopping milk bottles .................................................................................................................. 33 Exercise 6: Opening and closing a supply pipe ............................................................................................. 39 Exercise 7: Shutting off using a quick power lockout .................................................................................... 47 Exercise 8: Actuating a shut-off device ......................................................................................................... 53 Exercise 9: Expanding a control system to enable cheese pressing .............................................................. 61 Exercise 10: Clamping a workpiece ............................................................................................................... 69 Exercise 11: Loading mesh baskets .............................................................................................................. 77 Exercise 12: Actuating a sliding door ............................................................................................................ 83 Exercise 13: Feeding in wooden boards ........................................................................................................ 91 Exercise 14: Pressing drinks cans ................................................................................................................. 97 Exercise 15: Stamping valve housings ........................................................................................................ 105 Exercise 16: Mounting locking clips ............................................................................................................ 113 Exercise 17: Labeling paint buckets ............................................................................................................ 121 Exercise 18: Cleaning workpieces ............................................................................................................... 129 Exercise 19: Pressing product labels into place .......................................................................................... 137

© Festo Didactic 541088

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Contents

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© Festo Didactic 541088

Exercise 1: Pressing cheeses Training aims After completing this exercise, you will: • Be familiar with the setup and function of a single-acting cylinder. • Be able to calculate the piston force of a single-acting cylinder. • Be familiar with the setup and function of a 3/2-way valve, normally closed. • Be able to recognize and sketch the various types of actuation used for directional control valves. • Be able to explain and set up direct actuation.

Description of the problem In cheese manufacturing, pneumatic cylinders are used to press the cheese into molds. Develop a control system that can be used to carry out this process.

Layout

Cheese manufacturing – press

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Exercise 1: Pressing cheeses

3. 4. 5.

Description of the process The cheese is inserted in the press by hand. When a pushbutton actuator is pressed, the piston rod on the cylinder advances and presses the lid onto the mold. The pushbutton actuator is held down until the pressing procedure is complete. When the pushbutton actuator is released, the piston rod retracts again, allowing access to the mold. The cheese can then be removed.

• •

Parameters Use a single-acting cylinder. The cylinder must be pneumatically controlled using a manually operated valve.

1. 2. 3. 4. 5. 6. 7. 8.

Work assignments Describe the setup and function of a single-acting cylinder. Calculate the piston force of a single-acting cylinder. Describe the setup and function of a 3/2-way valve, normally closed. Complete the pneumatic circuit diagram for the press. Create an equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

1. 2.

Safety instructions • •

4

For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 1: Pressing cheeses

1. Setup and function of a single-acting cylinder

Single-acting cylinder – circuit symbol and cutaway view

a) Compare the circuit symbol shown above with the schematic diagram of the single-acting cylinder. Determine whether or not the two diagrams match. The two diagrams match. The diagram shows a single-acting cylinder. In the normal position, the piston rod is kept retracted by the spring return. A permanent magnet is mounted on the piston for position sensing purposes.

b) Assign the corresponding number to each component in the drawing above. Component

Designation

4

Cylinder barrel

1

End cap

8

Bearing cap

6

Piston rod

10

Piston

3

Ring magnet

11

Piston seal

9

Spring return

2

Compressed air supply port

7

Guide bushing

5

Exhaust hole

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Exercise 1: Pressing cheeses

c)

Describe the setup and function of a single-acting cylinder. The compressed air flows into the cylinder’s piston chamber. Pressure is built up in the chamber and force is applied to the surface of the piston as a result. When this force exceeds the static friction, the piston advances. The full operating pressure is not reached until the piston is fully advanced. When the pressure drops, the built-in spring return pushes the piston back to its start position. The spring force is not great enough to move heavy loads on the piston rod. As such, single-acting cylinders only work in one direction.

2. Calculating the piston force of a single-acting cylinder Information The theoretical piston force is calculated using the following formula: Fth = A ∙ p Fth Theoretical piston force (N)

A

Useful piston area (m2) D2 ⋅ π ( ) 4

p

D

Cylinder diameter (m)

Working pressure (Pa)

In practice, it is the effective piston force Feff that is important. When calculating this, the frictional resistance must be taken into consideration. Under normal operating conditions (pressure range: 400 to 800 kPa/4 to 8 bar), the friction forces (FR) can be assumed as being approx. 10% of the theoretical piston force. The effective piston force of a single-acting cylinder is calculated as follows: Feff = A ( p – (FR + FF) Feff Effective piston force (N) FR Friction force (approx. 10% of Fth) (N) FF Spring return force (N)

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© Festo Didactic 541088

Exercise 1: Pressing cheeses

–

Calculate the effective piston force during the forward stroke for the cylinder in question at a working pressure of 600 kPa (6 bar). Calculating the piston area and piston force (Cylinder diameter in m, working pressure in Pa) A= (

0.022 ⋅ 3.14 ) = 0.000314 m2 4

Calculating the piston area and piston force (Cylinder diameter in cm, working pressure in bar) A= (

22 ⋅ 3.14 ) = 3.14 cm2 4

Feff = 0.9 ⋅ A ⋅ p – FF

Feff = 0.9 ⋅ A ⋅ p – FF

Feff = 0.9 ⋅ 0.000314 m2 ⋅ 600,000 Pa – 13.6 N

Feff = 0.9 ⋅ 3.14 cm2 ⋅ 60

Feff = 169.56 N – 13.6 N = 155.96 N

Feff = 169.56 N – 13.6 N = 155.96 N

N cm2

– 13.6 N

Note Consult the cylinder data sheet for the necessary data. Training note For the cylinder in question, the piston diameter is 20 mm and the spring return force is 13.6 N.

3. How a 3/2-way valve, normally closed, works a) Complete the circuit symbol of a manually operated, normally closed 3/2-way valve with spring return.

3/2-way valve, manually operated, with spring return, normally closed – circuit symbol and cutaway view

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Exercise 1: Pressing cheeses

b) Describe how the 3/2-way valve works. A 3/2-way valve has 3 ports and 2 switching positions. It is shown here in its normal position. "Normally closed" means that the compressed air cannot flow through the valve. When the pushbutton actuator is pressed, the 3/2-way valve opens up the air flow. The piston chamber of a connected cylinder is pressurized and the piston rod advances.

4. Completing the pneumatic circuit diagram –

8

Complete the pneumatic circuit diagram for the press. Add any incomplete circuit symbols. Label the individual components and enter the missing port designations.

© Festo Didactic 541088

Exercise 1: Pressing cheeses

5. Creating the equipment list –

Create the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

6. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

7. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to the level specified in the exercise instructions. • Allow the control system to run through several complete cycles.

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Exercise 1: Pressing cheeses

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

8. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position In its initial position, the 3/2-way valve -SJ1 is closed. The piston rod on cylinder -MM1 is retracted. Step 1-2 When the pushbutton actuator for the 3/2-way valve -SJ1 is pressed, compressed air flows into the piston chamber of cylinder -MM1 and the piston rod advances. Step 2-3 When the pushbutton actuator is released, the 3/2-way valve -SJ1 is exhausted and the piston rod of cylinder -MM1 is pushed back to its initial position by the spring return.

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© Festo Didactic 541088

Exercise 2: Run-on brake on a drive shaft Training aims After completing this exercise, you will: • Be familiar with the setup and function of a 3/2-way valve, normally open. • Be able to recognize and sketch the various types of actuation used for directional control valves. • Be able to explain and set up direct actuation.

Description of the problem An older engine plant has been retrofitted with a brake. The brake is designed to reduce the length of time for which the drive shaft runs on when the engine comes to a stop after the clutch is disengaged. The brake force is generated by the spring return in the cylinder. The brake is actuated via a pushbutton actuator on the machine control console.

Layout

Run-on brake

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Exercise 2: Run-on brake on a drive shaft

Description of the process 1. When the pushbutton actuator is pressed, the piston rod on the cylinder retracts due to the force of the spring return. 2. The pushbutton actuator is held down for as long as the drive shaft needs to be braked. 3. When the pushbutton actuator is released, the piston rod advances again, releasing the brake.

• •

Parameters Use a single-acting cylinder. The cylinder must be pneumatically controlled using a manually operated valve.

1. 2. 3. 4. 5. 6.

Work assignments Answer the questions on the 3/2-way valve with pushbutton actuator, normally open. Complete the pneumatic circuit diagram for the run-on brake control system. Change the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

Safety instructions • •

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For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 2: Run-on brake on a drive shaft

1. How a 3/2-way valve works a) Complete the circuit symbol for the 3/2-way valve. It must possess the following functions: manually operated, spring return, normally open.

3/2-way valve, manually operated, with spring return, normally open – circuit symbol and cutaway view

b) Explain how a 3/2-way valve, normally open, works. A 3/2-way valve, normally open, has 3 ports and 2 switching positions. It is shown here in its normal position. This variant of the valve is normally open. This means that the compressed air flows through the valve to the cylinder, holding the cylinder's piston rod in the advanced end position. When the pushbutton actuator is pressed, the 3/2-way valve closes, shutting off the compressed air. The cylinder's piston chamber can exhaust via the 3/2-way valve, and the piston rod retracts.

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Exercise 2: Run-on brake on a drive shaft

2. Completing the pneumatic circuit diagram –

Complete the pneumatic circuit diagram for the run-on brake. Add any incomplete circuit symbols. Label the individual components and enter the missing port designations.

Note Control systems can be shown in their initial positions.

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Exercise 2: Run-on brake on a drive shaft

3. Changing the equipment list –

Change the equipment list below to match the requirements for this control system.

Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Equipment list, template

Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

1

-SJ1

3/2-way valve with pushbutton actuator, normally open

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Modified equipment list

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar).

© Festo Didactic 541088

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Exercise 2: Run-on brake on a drive shaft

• • • •

Switch on the compressed air supply at the service unit. Check that the control system is working correctly. Increase the pressure to the level specified in the exercise instructions. Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The 3/2-way valve is open in the "allow flow" direction, and the piston chamber is pressurized. The piston rod of cylinder -MM1 is advanced. Step 1-2 When the pushbutton actuator of valve -SJ1 is pressed, the piston chamber is exhausted via the 3/2-way valve and the piston rod of cylinder -MM1 retracts. Step 2-3 When the pushbutton actuator is released again, the spring pushes the 3/2-way valve into its normal position, the piston chamber is pressurized and the piston rod of cylinder -MM1 advances again.

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© Festo Didactic 541088

Exercise 3: Clamping boards on a saw machine Training aims After completing this exercise, you will: • Be able to recognize and sketch the various types of actuation used for directional control valves. • Be able to explain and set up direct actuation. • Be able to analyze and evaluate control systems.

Description of the problem A circular saw is used to cut boards to length. They are inserted in the saw machine by hand. The awing process itself is controlled using a dedicated control console. To this end, the boards are clamped on the saw table. For the test build, the control system will be set up with only one cylinder.

Layout

Saw machine

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Exercise 3: Clamping boards on a saw machine

1. 2. 3. 4.

Description of the process A board is placed on the saw table by hand. When a switch is pressed, the cylinder's piston rod advances to hold the board in place. The piston rod remains in this position when the switch is released. When the switch is reset, the piston rod moves to the retracted end position and remains there until the switch is pressed again.

• •

Parameters Use the control system from one of the previous tasks and adapt it to deal with this problem. For example, you could use just one single-acting cylinder to develop the control system.

1. 2. 3. 4. 5. 6.

Work assignments Read about the different types of actuation used for directional control valves. Complete the pneumatic circuit diagram for the clamping device. Change the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

Safety instructions • •

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For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 3: Clamping boards on a saw machine

1. Types of actuation used for directional control valves Information The type of actuation used for the directional control valves depends on the system requirements. The following types of actuation are possible: • Manually operated • Mechanically actuated • Pneumatically actuated • Combined types of actuation A complete description of a directional control valve in the pneumatic circuit diagram includes: • The basic type of actuation method • The return control used for the valve • The pilot control (where applicable) • Additional types of actuation (where applicable) Each actuation symbol is drawn on the side of the switching position that corresponds to its direction of action.

Function

Symbol

Manual operation Pressing

Turning

Lever operation

Mechanical actuation With plunger

With roller plunger

With roller lever

Pneumatic actuation Using compressed air

Pneumatic spring return

Mechanical components Spring return

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Exercise 3: Clamping boards on a saw machine

2. Completing the pneumatic circuit diagram a) Complete the circuit diagrams below by entering the required type of actuation for the directional control valve in question.

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Exercise 3: Clamping boards on a saw machine

b) Select the right control system and explain your choice. The correct answer is a). Reason The cylinder's piston rod must be in the retracted end position when the selector switch on the 3/2way valve is not actuated.

3. Changing the equipment list –

Change the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

1

-SJ1

3/2-way valve with selector switch, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Modified equipment list

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

© Festo Didactic 541088

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Exercise 3: Clamping boards on a saw machine

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to the level specified in the exercise instructions. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The "allow flow" direction in the 3/2-way valve is blocked. The cylinder’s piston rod is retracted. Step 1-2 When the selector switch on the 3/2-way valve -SJ1 is actuated, compressed air flows into the piston chamber of cylinder -MM1 and the piston rod advances. Step 2-3 When the selector switch is reset, the 3/2-way valve is exhausted and the piston rod of cylinder -MM1 is pushed back to its initial position by the spring return.

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© Festo Didactic 541088

Exercise 4: Loading packages Training aims After completing this exercise, you will: • Be familiar with the setup and function of a double-acting cylinder. • Be able to calculate the piston force of a double-acting cylinder for the forward and return strokes. • Be familiar with the setup and function of a 5/2-way valve.

Description of the problem On a loading station, packages are separated out and sorted into transport containers by hand. When the containers are full, they are shipped out and replaced with new, empty containers. During the changeover, the flow of materials needs to be paused, though the conveyor belt keeps running. The packages are stopped from moving by a mechanical block (locking blade). This needs to be operated from the loading station.

Layout

Loading station

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Exercise 4: Loading packages

Description of the process 1. When the selector switch is pressed, the piston rod on the cylinder advances and pushes the locking blade into the flow of materials. 2. The piston rod remains in this position when the selector switch is released, so the flow of materials cannot continue. 3. When the selector switch is released, the piston rod moves to the retracted end position, allowing the flow of materials to continue. The piston rod remains retracted until the selector switch is actuated again.

•

Parameters Since work needs to be carried out on both the forward and the return strokes, you will need to use a double-acting cylinder.

1. 2. 3. 4. 5. 6. 7. 8.

Work assignments Describe the setup and function of a double-acting cylinder. Calculate the piston force of a double-acting cylinder for the forward and return strokes. Describe how a 5/2-way valve works. Complete the pneumatic circuit diagram for the loading station. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

Safety instructions • •

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For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 4: Loading packages

1. Setup and function of a double-acting cylinder

Double-acting cylinder – circuit symbol and cutaway view

a) Match up the numbers from the schematic drawing to the individual components of the double-acting cylinder. Component

Designation

4

Cylinder barrel

1

End cap

7

Bearing cap

9

Piston rod

13

Piston

3

Ring magnet

14

Piston seal

2

Compressed air supply port for piston chamber

6

Compressed air supply port for piston rod chamber

5

Seal

8

Seal and dirt wiper

10

Guide bushing

12

Damping piston

11, 15

Adjustable end-position cushioning

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Exercise 4: Loading packages

b) Compare the circuit symbol shown above with the schematic diagram of the double-acting cylinder. Determine whether or not the two diagrams match. The two diagrams match. The diagram shows a double-acting cylinder. A permanent magnet is mounted on the piston for position sensing purposes. The cylinder has adjustable end-position cushioning on both sides.

c)

Write down the similarities and differences between single-acting and double-acting cylinders. Both types of cylinder comprise a cylinder barrel, a piston and a piston rod. The double-acting cylinder does not have a spring return. The double-acting cylinder has two supply ports.

d) Describe how a double-acting cylinder works. The double-acting cylinder has a higher air consumption than the single-acting cylinder. Due to the different surface areas on the piston and piston rod sides, there are different effective forces at the same pressure. Forward stroke The compressed air flows through the piston chamber supply port and into the cylinder. Pressure is built up in the chamber and force is applied to the surface of the piston as a result. When this force exceeds the static friction, the piston advances – and as a result, so does the piston rod. The air in the piston rod chamber escapes through the port on the piston rod side. The full operating pressure is not reached until the piston is fully advanced. Return stroke On reversal, the air flows into the piston rod chamber supply port, where it builds up the pressure until the piston moves back. The air escapes from the piston chamber via the piston chamber port.

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© Festo Didactic 541088

Exercise 4: Loading packages

e) What requirements must a directional control valve fulfill in order to be able to actuate a double-acting cylinder? Compressed air must be available in both switching positions, as the double-acting cylinder cannot retract without it. It must be possible to exhaust the opposite cylinder chamber at all times. f)

Explain why the actuation function for the directional control valve needs to be performed by a switch. A switch needs to be used because a button cannot be held down for the entire time it takes to change the containers.

2. Calculating the piston force of a double-acting cylinder for the forward and return strokes Information The theoretical piston force is calculated using the following formula: Fth = A ⋅ p For double-acting cylinders, the following applies: Forward stroke Feff = (A ⋅ p) – FR Return stroke Feff Effective piston force (N) A Useful piston area (m2) D2 ⋅ π ( ) 4 p D

Working pressure (Pa) Piston diameter (m)

© Festo Didactic 541088

Feff = (A' ⋅ p) – FR

A'

Useful piston ring area (m2) (D2 − d 2 ) ⋅ π 4

FR d

Friction force (approx. 10% of Fth) (N) Piston rod diameter (m)

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Exercise 4: Loading packages

–

Calculate the effective piston force during the return stroke for the cylinder in question at a working pressure of 600 kPa (6 bar). Calculating the piston area (Cylinder diameter in m)

Calculating the piston ring area

(0.022 m 2 - 0.0082 m 2 ) ⋅ π 0.022 m 2 ⋅ π = A (= ) 0.0002639 m 2 ) 0.000314 = A' (= m2 4 4

(Cylinder diameter in cm) 2.02 cm 2 ⋅ π (2.02 cm 2 - 0.82 cm 2 ) ⋅ π 2 = A' (= = A (= ) 3.14 cm ) 2.639 cm 2 4 4

Calculating the piston force, forward stroke (Working pressure in Pa)

Calculating the piston force, return stroke

Feff = (A ⋅ p) – FR Feff = 0.9 ⋅ A ⋅ p Feff = 0.9 ⋅ 0.000314 m2 ⋅ 600,000 Pa Feff = 169.56 N

Feff = (A' ⋅ p) – FR Feff = 0.9 ⋅ A' ⋅ p Feff = 0.9 ⋅ 0.0002639 m2 ⋅ 600,000 Pa Feff = 142.51 N

(Working pressure in bar) Feff = (A ⋅ p) – FR Feff = 0.9 ⋅ A ⋅ p Feff = 0.9 ⋅ 3.14 cm2 ⋅ 60 Feff = 169.56 N

Feff = (A' ⋅ p) – FR Feff = 0.9 ⋅ A' ⋅ p N 2

cm

Feff = 0.9 ⋅ 2.639 cm2 ⋅ 60

N cm2

Feff = 142.51 N

Note Consult the cylinder data sheet for the necessary data. Training note For the cylinder in question, the piston diameter is 20 mm and the piston rod diameter is 8 mm.

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© Festo Didactic 541088

Exercise 4: Loading packages

3. How a 5/2-way valve works a) Complete the circuit symbol of a manually operated 5/2-way valve with locking function and spring return, designating the ports.

5/2-way valve, manually operated, with locking function and spring return – circuit symbol and cutaway view

b) Describe how a 5/2-way valve works when port 2 of the valve is connected to the piston rod side of a double-acting cylinder and port 4 to the piston side. How a 5/2-way valve, unactuated, works When the 5/2-way valve is not actuated, the spring return holds the control piston valve in its initial position. The piston rod side of a connected double-acting cylinder is pressurized and the piston rod retracts. How a 5/2-way valve, actuated, works When the 5/2-way valve is actuated, the control piston is pushed against the valve's spring return. In this state, the supply port is connected to the piston side of the cylinder via the valve, while the piston rod side is exhausted via the valve. The pressure that builds up on the piston side causes the piston rod to advance. As soon as the piston rod reaches its advanced end position, the maximum operating pressure builds up on the piston side of the cylinder. Actuation with a switch If the valve is actuated with a switch, the valve position remains unchanged until the switch is switched back.

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Exercise 4: Loading packages

4. Completing the pneumatic circuit diagram –

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Complete the pneumatic circuit diagram for the loading station. Label the individual components and enter the missing port designations.

© Festo Didactic 541088

Exercise 4: Loading packages

5. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-SJ1

5/2-way valve with selector switch

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

6. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

7. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to the level specified in the exercise instructions. • Allow the control system to run through several complete cycles.

© Festo Didactic 541088

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Exercise 4: Loading packages

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

8. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position In its initial position, the 5/2-way valve -SJ1 is not actuated. The piston chamber of cylinder -MM1 is exhausted. The piston rod chamber of cylinder -MM1 is pressurized. The piston rod is retracted. Step 1-2 When the selector switch on the 5/2-way valve -SJ1 is actuated, compressed air flows into the piston chamber (left-hand port (piston side)) of double-acting cylinder -MM1, and the piston rod chamber (right-hand port (piston rod side)) is exhausted. The piston rod advances. Step 2-3 When the selector switch on the 5/2-way valve -SJ1 is reset, the piston chamber of double-acting cylinder -MM1 is exhausted and compressed air flows into the piston rod chamber. The piston rod is retracted.

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Exercise 5: Stopping milk bottles Training aims After completing this exercise, you will: • Be able to explain and set up indirect actuation. • Be familiar with the function of a pneumatically activated 5/2-way valve. • Be familiar with the difference between a signaling element and a control element.

Description of the problem A bottling system is used to fill bottles with milk. The bottles are fed in and stopped under the bottling machine by a conveyor belt. This task is performed with the aid of a pneumatic cylinder. A test setup of the stopping system will be used to check the positioning accuracy of the stopping process. The stopping procedure needs to be started from the system's control console.

Layout

Bottling system for milk

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Exercise 5: Stopping milk bottles

Description of the process 1. When a selector switch is actuated, the piston rod on the cylinder advances and pushes the locking blade into the flow of materials, stopping the milk bottles in place. 2. When the selector switch is released, the piston rod moves to the retracted end position, allowing the flow of materials to continue. 3. The piston rod remains retracted until the selector switch is actuated again.

• • •

Parameters It must be possible to stop the flow of materials from a central control console. Since the control console can be used to access compressed air, a pneumatic solution is required. The control valve for the cylinder should be actuated pneumatically.

1. 2. 3. 4. 5.

Work assignments Complete the pneumatic circuit diagram for the materials blocking system. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

Additional exercise • Explain the term "indirect actuation."

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

Safety instructions • •

34

For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 5: Stopping milk bottles

1. Completing the pneumatic circuit diagram –

Complete the pneumatic circuit diagram for the stopping system. Add any incomplete circuit symbols. Label the individual components and enter the missing port designations.

2. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-QM1

5/2-way valve, pneumatic, with spring return

1

-SJ1

3/2-way valve with selector switch, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

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Exercise 5: Stopping milk bottles

3. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

4. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to the level specified in the exercise instructions. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

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Exercise 5: Stopping milk bottles

5. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The piston rod on cylinder -MM1 is retracted. The selector switch on the 3/2-way valve -SJ1 is not actuated. Step 1-2 When the selector switch on the 3/2-way valve -SJ1 is actuated, the pneumatic pilot port 14 on the 5/2-way valve -QM1 is pressurized with compressed air. This switches the 5/2-way valve. The lefthand port (piston side) of the double-acting cylinder is pressurized with compressed air, and the righthand port (piston rod side) is exhausted. The cylinder’s piston rod advances. Step 2-3 When the selector switch is reset, the compressed air in the 3/2-way valve is shut off. Pilot port 14 on the 5/2-way valve is exhausted. The spring return pushes the valve piston back into its initial position. This exhausts the piston side of the cylinder and pressurizes the piston rod side with compressed air. The piston rod on the cylinder moves to the retracted end position.

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Exercise 5: Stopping milk bottles

6. Additional exercise: "Indirect actuation" –

Explain the term "indirect actuation." Indirect actuation Cylinders with a large piston diameter require a high air rate. A control element with a high nominal flow rate is required to actuate them. If the force required to actuate the valve is too great for manual operation, an indirect actuation system will need to be set up. In this system, a second, smaller valve generates a signal that provides the force necessary to switch the control element.

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Exercise 6: Opening and closing a supply pipe Training aims After completing this exercise, you will: • Be able to measure the pressure in pneumatic control systems. • Be familiar with the setup and function of a one-way flow control valve. • Be able to distinguish between flow control methods and use them in accordance with specifications.

Description of the problem Find a way to open and close the locking blade in a pipe. Use a valve with a selector switch for the actuation. Use a double-acting cylinder as the drive.

Layout

Shut-off device with spool valve

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Exercise 6: Opening and closing a supply pipe

Description of the process 1. When the selector switch is actuated, the piston rod on the cylinder advances to allow the air to flow through. 2. When the selector switch is reset, the piston rod returns to its normal position and the locking blade closes.

• •

Parameters The locking blade must open and close slowly in order to ensure that the pipe is not subjected to excessive loads (there should be no wave formation). The speed of the forward and return strokes must be adjustable. Each forward and return stroke should take 1 s.

1. 2. 3. 4. 5. 6. 7.

Work assignments Describe how a pressure gauge works. Describe how a one-way flow control valve works. Complete the pneumatic circuit diagram. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

•

Safety instructions • •

40

For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 6: Opening and closing a supply pipe

1. How a pressure gauge works

Bourdon pressure gauge – circuit symbol and cutaway view

–

Describe how a Bourdon pressure gauge works. A Bourdon pressure gauge consists essentially of a C-shaped, bent metal tube, which is sealed at one end and rigidly connected to the connecting flange at the other. The pressure that needs to be measured is generated in the tube, and ambient pressure prevails outside of the tube as a reference value. If the measured pressure is lower than the atmospheric pressure, the metal tube’s curvature increases. If the measured pressure is greater than the atmospheric pressure, the metal tube straightens out. A measuring mechanism is attached to the sealed end of the tube so that its displacement can be indicated on a scale. The scale is linear, and can show both overpressure and partial vacuum (negative values).

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Exercise 6: Opening and closing a supply pipe

2. How a one-way flow control valve works

One-way flow control valve – circuit symbol and cutaway views

a) Describe how a one-way flow control valve works. In a one-way flow control valve, the air flow is controlled in one direction only. The check valve shuts off the air flow in one direction so that the air can only flow via the set cross section. Air flows freely in the reverse direction through the open check valve. These valves are used primarily to regulate the speed of pneumatic cylinders. One-way flow control valves can be used to control the speed of the piston rod by regulating the flow rate.

b) Describe the two types of flow control used in a double-acting cylinder. Supply air flow control With supply air flow control, the one-way flow control valves are installed in such a way that the air flow to the cylinder is controlled. The exhaust air can escape freely on the outlet side via the check valve. The smallest fluctuations in load at the piston rod, e.g. when the rod passes a proximity sensor, result in erratic feed speeds. A load in the cylinder's direction of movement accelerates the cylinder above the set value.

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Exercise 6: Opening and closing a supply pipe

Exhaust air flow control With exhaust air flow control, the supply air flows freely to the cylinder and the flow control valve in the outflow pipe offers resistance to the outward flow. The piston is clamped between two air cushions that build up due to the pressure of the supply air and the resistance of the flow control valve for the exhaust air. This configuration of one-way flow control valves helps greatly to improve the feed behavior. Exhaust air flow control should be used with double-acting cylinders.

3. Completing the pneumatic circuit diagram a) Complete the circuit diagram for the shut-off device. Complete any incomplete circuit symbols, and add any that are missing. Label the individual components and enter the missing port designations.

Note The on-off valve with filter regulating valve and the distributor block are not shown. These components are required to set up the control system.

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Exercise 6: Opening and closing a supply pipe

b) What type of flow control does this control system provide? This control system provides exhaust air flow control. The supply air flows freely to the cylinder via the check valve. The exhaust air flows through the flow control valve.

4. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

2

-PG1, -PG2

Pressure gauge

2

-RZ1, -RZ2

One-way flow control valve

1

-SJ1

5/2-way valve with selector switch

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

5. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

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Exercise 6: Opening and closing a supply pipe

6. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to the level specified in the exercise instructions. • Set the one-way flow control valve to match the specified retraction and advancing times. Use a stopwatch to do this. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

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Exercise 6: Opening and closing a supply pipe

7. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position In its initial position, the piston rod on cylinder -MM1 is retracted. The piston chamber is exhausted via the 5/2-way valve -SJ1. Step 1-2 When the 5/2-way valve -SJ1 is switched, the piston chamber of cylinder -MM1 is pressurized via the one-way flow control valve. The piston rod on the cylinder moves to the advanced end position. Step 2-3 When the selector switch is reset, the piston rod chamber of cylinder -MM1 is pressurized via the oneway flow control valve and the 5/2-way valve. The piston rod on the cylinder is retracted. The retracting time is set via the one-way flow control valve. Use a stopwatch to do this.

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Exercise 7: Shutting off using a quick power lockout Training aims After completing this exercise, you will: • Be able to set the advancing and retracting speeds of cylinders. • Be able to distinguish between flow control methods and use them accordingly.

Description of the problem A bottling system is used to fill bottles with milk. The pipes through which the milk flows are opened and closed using a knife gate valve. In order to prevent the milk from spilling over at the start of the filling process, the opening process needs to be executed slowly. The closing process needs to be executed quickly.

Layout

Filling milk bottles

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Exercise 7: Shutting off using a quick power lockout

Description of the process 1. When a selector switch is actuated, a knife gate valve is opened slowly. 2. When the selector switch is reset, the knife gate valve closes quickly.

•

Prerequisites The speed regulation should allow the valve to open at an even speed.

1. 2. 3. 4. 5. 6.

Work assignments Select the appropriate flow control method. Complete the pneumatic circuit diagram for the shut-off device. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

Safety instructions • •

48

For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 7: Shutting off using a quick power lockout

1. Selecting the flow control method –

Decide whether supply air flow control or exhaust air flow control is most appropriate for solving this problem. Write down the reasoning behind your decision. Exhaust air flow control is the most suitable type of flow control for this problem. Exhaust air flow control guarantees an even speed on the forward stroke, and is not affected by load.

2. Completing the pneumatic circuit diagram –

Complete the circuit diagram below. Observe the specified parameters.

Note The on-off valve with filter regulating valve and the distributor block are not shown. These components are required to set up the control system.

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Exercise 7: Shutting off using a quick power lockout

3. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-RZ1

One-way flow control valve

1

-SJ1

5/2-way valve with selector switch

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to the level specified in the exercise instructions. • Allow the control system to run through several complete cycles.

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Exercise 7: Shutting off using a quick power lockout

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

Note This control system uses exhaust air flow control. Use a stopwatch to set the required time. The setting can be fixed using a lock nut.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position In its initial position, the piston rod on cylinder -MM1 is retracted. The piston chamber is exhausted via the 5/2-way valve -SJ1. Step 1-2 When the 5/2-way valve -SJ1 is switched, the piston chamber of cylinder -MM1 is pressurized with compressed air. The piston rod chamber is exhausted via the one-way flow control valve -RZ1 and the 5/2-way valve -SJ1. The piston rod on the cylinder moves slowly to the advanced end position. The advancing time is set using the one-way flow control valve. Step 2-3 When the selector switch is reset, the piston rod chamber of the cylinder is pressurized without flow control via the one-way flow control valve and the 5/2-way valve. The piston chamber is exhausted via the 5/2-way valve -SJ1. The piston rod on the cylinder moves to the retracted end position.

© Festo Didactic 541088

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Exercise 7: Shutting off using a quick power lockout

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© Festo Didactic 541088

Exercise 8: Actuating a shut-off device Training aims After completing this exercise, you will: • Be familiar with a way of storing signals in pneumatic control systems. • Be able to set the advancing and retracting speeds of cylinders.

Description of the problem The ball valve of a filling system for plastic granulate needs to be closed quickly, but opened slowly.

Layout

Shut-off device with ball valve

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Exercise 8: Actuating a shut-off device

Description of the process 1. When a pushbutton actuator is pressed, a shut-off device (ball valve) is opened slowly. 2. When a second pushbutton actuator is pressed, the shut-off device closes quickly.

• •

Parameters Use a double-acting cylinder. The closing process should be carried out using the return stroke of the cylinder.

1. 2. 3. 4. 5. 6. 7.

Work assignments Describe how a quick-exhaust valve works. Describe how a 5/2-way bistable valve works. Complete the pneumatic circuit diagram for the shut-off device. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

Safety instructions • •

54

For this exercise, limit the pressure on the filter regulating valve (service unit) to max. 350 kPa (3.5 bar). If tubing slips off: switch off the compressed air supply immediately.

© Festo Didactic 541088

Exercise 8: Actuating a shut-off device

1. How a quick-exhaust valve works

Quick-exhaust valve – circuit symbol and cutaway views

–

Describe how a quick-exhaust valve works. Quick-exhaust valves can be used to achieve higher piston speeds on the return stroke of single and double-acting cylinders. The quick-exhaust valve reduces the flow resistance of the exhaust air during the movement. Compressed air flows from the control valve and via the quick-exhaust valve to the cylinder. This closes exhaust port 3. When the pressure at port 1 falls, exhaust flow occurs from port 2 to port 3. In order to allow optimum quick exhausting, the valve must be mounted directly on the cylinder's air connection.

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Exercise 8: Actuating a shut-off device

2. How a 5/2-way bistable valve works

5/2-way bistable valve – circuit symbol and cutaway view

a) Describe how the 5/2-way bistable valve works. A 5/2-way bistable valve has 5 working ports and 2 switching positions. The valve is equipped with a latching function, and a short signal (pulse) at the pilot ports suffices for reversal. When a compressed air pulse is generated at one of the two pilot ports (12/14), the valve piston is moved to the opposite switching position. The compressed air from the working port holds the valve piston in this position until a compressed air pulse on the opposite side switches the valve back to the previous position. If there are signals at both pilot ports, the one that arrives first takes precedence. A pneumatic signal at pilot port 12 results in flow from port 1 to port 2. A pneumatic signal at pilot port 14 results in flow from port 1 to port 4.

b) Describe how the valve shown above behaves when port 14 is briefly pressurized with compressed air. When pilot port 14 is pressurized with compressed air, the valve piston is moved to the right. The compressed air flows from port 1 to port 4. Port 2 is exhausted via port 3. When pilot port 14 is depressurized again, the valve remains in the same position.

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Exercise 8: Actuating a shut-off device

3. Completing the pneumatic circuit diagram a) Complete the circuit diagram below for the shut-off device. Add any incomplete circuit symbols. Label the individual components and enter the missing port designations.

Note The on-off valve with filter regulating valve and the distributor block are not shown. These components are required to set up the control system.

b) How do you set the speed of the advancing movement? The advancing time is set via the one-way flow control valve -RZ1. The setting on the one-way flow control valve can be fixed using a lock nut.

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Exercise 8: Actuating a shut-off device

4. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-PG1

Pressure gauge

1

-RZ1

One-way flow control valve

1

-KH1

Quick-exhaust valve

1

-QM1

5/2-way bistable valve

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

5. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

6. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit.

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Exercise 8: Actuating a shut-off device

• • • •

Check that the control system is working correctly. Increase the pressure to the level specified in the exercise instructions. Set the one-way flow control valve to maintain an advancing time of approx. 1 s. Use a stopwatch to do this. Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

7. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position In its initial position, the piston rod should be retracted. The piston chamber is exhausted via the 5/2-way bistable valve -QM1, and the piston rod chamber pressurized. If the piston rod is in the advanced end position, it must be moved to the retracted end position by actuating the 3/2-way valve -SJ2. Step 1-2 When the 3/2-way valve -SJ1 is actuated, the 5/2-way bistable valve –QM1 is switched and the piston chamber of cylinder –MM1 is pressurized via the quick-exhaust valve –KH1. The piston rod chamber is exhausted via the one-way flow control valve –RZ1. The piston rod on the double-acting cylinder -MM1 moves to the advanced end position. The piston then remains in this position, even when the pushbutton actuator for the 3/2-way valve -SJ1 is released again.

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Exercise 8: Actuating a shut-off device

Step 2-3 When the 3/2-way valve -SJ2 is actuated, the 5/2-way bistable valve –QM1 is switched back again. The piston rod chamber of cylinder -MM1 is pressurized via the one-way flow control valve –RZ1. The piston chamber of cylinder –MM1 is exhausted via the quick-exhaust valve –KH1 and the 5/2-way bistable valve –QM1. The piston rod on the cylinder -MM1 moves quickly to the retracted end position. Advancing time The advancing time is set using the one-way flow control valve -RZ1. Use a stopwatch to do this. This setting can be fixed using a lock nut.

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Exercise 9: Expanding a control system to enable cheese pressing Training aims After completing this exercise, you will: • Be able to expand an existing control system. • Be able to analyze a proposed solution. • Be able to implement an OR operation.

Description of the problem In cheese manufacturing, pneumatic cylinders are used to press the cheese into molds. The pressing procedure is operated using a pushbutton actuator. You now need to implement a system that also allows operation to be carried out using 2 pushbutton actuators so that the pressing procedure can be operated from the loading side or the unloading side. A solution variant for this purpose exists, but it does not possess the piston force required to press the cheese.

Layout

Cheese manufacturing – press

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Exercise 9: Expanding a control system to enable cheese pressing

3. 4. 5.

Description of the process The cheese is inserted in the press by hand. When a pushbutton actuator on either the loading or the unloading side of the system is pressed, the piston rod on the cylinder advances and presses the lid onto the device. The pushbutton actuator is held down until the pressing procedure is complete. When the pushbutton actuator is released, the piston rod retracts again, allowing access to the device. The cheese can then be removed.

• •

Parameters The cylinder must be pneumatically controlled using a second manually operated valve. It should be possible to operate the process using either of the two valves.

1. 2. 3. 4. 5. 6. 7.

Work assignments Analyze the proposed solution variants for the pneumatic circuit diagram. Describe how an OR valve works. Complete the pneumatic circuit diagram for the press. Update the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

1. 2.

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Exercise 9: Expanding a control system to enable cheese pressing

1. Analyzing the pneumatic circuit diagram The control system shown below has been used to expand the function as required. However, we have determined that it does not possess the piston force required to press the cheese. The piston force was only sufficient when both pushbuttons were pressed at the same time.

Proposed solution – pneumatic circuit diagram

Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Equipment list for proposed solution

–

Analyze the control system above and explain why it was not able to provide the required piston force. The piston force was not sufficient because part of the operating pressure escaped through the exhaust port of the valve that was not in use.

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Exercise 9: Expanding a control system to enable cheese pressing

2. How an OR valve works

OR valve – circuit symbol and cutaway views

–

Describe how an OR valve works. The OR valve has two inputs (1) and one output (2). When the left-hand input (1) is pressurized with compressed air, it seals off the piston for the righthand input (1). The compressed air flows from the left-hand input (1) to the output (2). When the compressed air from the right-hand input (1) reaches the output (2), the left-hand input (1) is shut off. When the compressed air flows back, the pressure conditions hold the piston in position. This valve is also called an OR gate. If a cylinder or a control element needs to be actuated from two or more locations, one or more OR valves must always be used. If there are signals at both inputs, the signal that arrives first or has the higher pressure will reach the output.

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Exercise 9: Expanding a control system to enable cheese pressing

3. Completing the pneumatic circuit diagram –

Complete the circuit diagram below for the press. Add any incomplete circuit symbols. Enter the missing port designations.

4. Updating the device list a) The device list for the original control system (see Exercise 1) must be changed in order to document the current status of the control system. Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Existing equipment list

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Exercise 9: Expanding a control system to enable cheese pressing

b) Update the equipment list. Enter the quantity, identification and designation of the required components in the table below. Quantity

Identification

Designation

1

-MM1

Cylinder, single-acting

1

-KH1

OR valve

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Updated equipment list

5. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

6. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to 600 kPa (6 bar). • Allow the control system to run through several complete cycles.

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Exercise 9: Expanding a control system to enable cheese pressing

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

7. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position In their initial positions, the 3/2-way valves -SJ1 and-SJ2 are closed. The piston rod on cylinder -MM1 is retracted. Step 1-2 When the pushbutton actuator for 3/2-way valve -SJ1 or -SJ2 is pressed, compressed air flows through the OR valve -KH1 and into the piston chamber of cylinder -MM1, causing the piston rod to advance. Step 2-3 When the pushbutton actuators are released, the 3/2-way valves -SJ1 and/or -SJ2 exhaust. The piston rod of cylinder -MM1 is pushed back to its initial position by the spring return.

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Exercise 9: Expanding a control system to enable cheese pressing

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Exercise 10: Clamping a workpiece Training aims After completing this exercise, you will: • Be able to implement an AND operation. • Be familiar with a way of sensing the end positions of cylinders. • Be able to draw the displacement-step diagram.

Description of the problem In a production plant, an automatic rotary indexing machine is used to feed in workpieces. The workpieces must be clamped in the individual workholders for machining. A test setup needs to be built to develop and test a clamping device.

Layout

Rotary indexing machine

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Exercise 10: Clamping a workpiece

Description of the process 1. The piston rod on the double-acting clamping cylinder must only advance when a pushbutton actuator is pressed AND the piston rod is in the retracted end position, otherwise it will not be possible to insert a workpiece for machining. 2. The clamping cylinder needs to remain in the advanced end position until the machining of the workpiece is complete. The machining time can vary. 3. The workpiece is released again when a second pushbutton actuator is pressed.

• • • •

1. 2. 3. 4. 5. 6. 7. 8.

Parameters The clamping process must not begin unless the cylinder's piston rod is in the retracted end position. When a second pushbutton actuator is pressed, the piston rod returns to the retracted end position and releases the workpiece. The retracting and advancing times for the piston rod should be approx. 1 s each. A pressure gauge should be mounted between the one-way flow control valve and the cylinder at each port to allow the operator to read the pressure.

Work assignments Describe how an AND valve works. Describe how a 3/2-way roller-actuated valve works. Complete the pneumatic circuit diagram. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system. Create the displacement-step diagram.

Additional exercise • What effect does moving the 3/2-way roller-actuated valve have on the system?

• • • • •

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Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

© Festo Didactic 541088

Exercise 10: Clamping a workpiece

1. How an AND valve works

AND valve – circuit symbol and cutaway views

–

Describe how an AND valve works. The AND valve has two inputs (1) and one output (2). The air can only flow through it when both input signals are present. If there is only an input signal at one of the two inputs, the flow will be shut off due to the differential forces at the piston spool. If there is a time delay between the two input signals, but they both have the same inlet pressure, the last signal that arrives reaches the output. If there is a difference in pressure between the two signals, the signal with the higher pressure closes the valve while the signal with the lower pressure reaches the output (2). The AND valve is used mainly for locking control systems, monitoring functions and AND logic operations. This valve is also called an AND gate.

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Exercise 10: Clamping a workpiece

2. How a 3/2-way roller-actuated valve works

3/2-way roller-actuated valve – circuit symbol and cutaway views; left: unactuated, right: actuated

a) Describe how a 3/2-way roller-actuated valve works. A 3/2-way roller-actuated valve has 3 working ports and 2 switching positions. The roller plunger can be actuated in a number of ways, e.g. by the trip cam of a cylinder. Thanks to the pilot control, a reduced actuating force is generated.

b) Describe how the pilot stage works. A duct with a small diameter connects supply port 1 with the pilot valve. When the pilot valve opens, the compressed air flows to the diaphragm and moves the valve disc of the main valve downward. When the pilot valve is closed, exhausting takes place along the guide bushing of the plunger. On directional control valves with a spring return, the valve disc of the main valve is returned to its normal position by the spring return.

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Exercise 10: Clamping a workpiece

3. Completing the pneumatic circuit diagram a) Complete the circuit diagram below for the clamping device. Add any incomplete circuit symbols. Label the individual components and enter the missing port designations.

b) Describe how the 3/2-way roller-actuated valve needs to be mounted in order to ensure that the control system works correctly. The 3/2-way roller-actuated valve must be mounted in such a way that it is actuated when the piston is in the retracted end position (piston rod retracted). If the valve is mounted in front of or below the cylinder cam, the roller plunger will not be actuated, and the valve will be unable to perform the AND function. The control system will not start up.

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Exercise 10: Clamping a workpiece

4. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-BG1

3/2-way roller-actuated valve, normally closed

1

-PG1, -PG2

Pressure gauge

1

-RZ1, -RZ2

One-way flow control valve

1

-QM1

5/2-way bistable valve

1

-KH1

AND valve

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

5. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

6. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Align the 3/2-way roller-actuated valve and check that the control system is working properly. • Increase the pressure to 600 kPa (6 bar).

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• •

Set the one-way flow control valves to match the specified retraction and advancing times of approx. 1 s. Use a stopwatch to do this. Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

7. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The system is pressurized. The 3/2-way roller-actuated valve -BG1 is actuated. The piston chamber of the double-acting cylinder -MM1 is exhausted; the piston rod chamber is pressurized. The piston rod of the cylinder -MM1 is in the retracted end position. Step 1-2 When the pushbutton actuator of the 3/2-way valve -SJ1 is pressed, there is compressed air at both inputs of the AND valve -KH1, and also at its output. The 5/2-way bistable valve -QM1 is reversed by the signal at pilot port 14. This reverses the cylinder and causes the piston rod to advance. The 3/2-way roller-actuated valve -BG1 switches to its normal position and the output signal at the AND valve is switched off. The latching function of the 5/2-way bistable valve -QM1 causes the cylinder's piston rod to remain in the advanced end position.

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Exercise 10: Clamping a workpiece

Step 2-3 When the pushbutton actuator for the 3/2-way valve -SJ2 is pressed, the 5/2-was bistable valve -QM1 is reversed again (signal at pilot port 12). The piston rod chamber of the cylinder is pressurized. The piston rod on the cylinder moves to the retracted end position. The 3/2-way roller-actuated valve -BG1 is actuated again.

8. Creating the displacement-step diagram –

Draw the displacement-step diagram with signal lines for the process described above.

9. The effect of moving the 3/2-way roller-actuated valve –

Describe the effect that moving the 3/2-way roller-actuated valve has on the control system. If the switching cam on the cylinder does not actuate the 3/2-way roller-actuated valve, the circuit will no longer work, as the condition -SJ1 AND -BG1 is not fulfilled. It will not be possible to start the process.

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Exercise 11: Loading mesh baskets Training aims After completing this exercise, you will: • Be able to build a latching circuit with an OR operation.

Description of the problem In a loading station, mesh baskets are loaded with packages. In order to ensure that the continuous flow of materials does not need to be paused at any time, the mesh baskets are placed at two output points on a conveyor. When a mesh basket is full, the packages are directed to the opposite output point by a deflector so that they can be transported away and a new mesh basket can be moved into position.

Layout

Loading station

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Exercise 11: Loading mesh baskets

1. 2. 3. 4.

• •

78

Description of the process When the pushbutton actuator is pressed, the piston rod on the cylinder advances and pushes the deflector into the flow of materials. The piston rod remains in this position when the pushbutton actuator is released, and the flow of materials is redirected. When a second pushbutton actuator is pressed, the piston rod moves back to the retracted end position, allowing the flow of materials to return to the original output point. The piston rod remains in this position until the first pushbutton actuator is pressed again.

Parameters The flow of materials needs to be controlled by two valves with pushbutton actuators: one pushbutton actuator each for blocking and one pushbutton actuator each for allowing flow. Since the signals from the pushbutton actuators are only issued for a short time, a control system the stores the signal statuses is required.

1. 2. 3. 4. 5.

Work assignments Complete the pneumatic circuit diagram. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe how the latching circuit works.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

© Festo Didactic 541088

Exercise 11: Loading mesh baskets

1. Completing the pneumatic circuit diagram –

Develop the latching circuit required for the task and add it to the circuit diagram below. Label the individual components.

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Exercise 11: Loading mesh baskets

2. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

2

-RZ1, -RZ2

One-way flow control valve

1

-QM2

5/2-way valve, pneumatic, with spring return

1

-QM1

3/2-way valve, pneumatic, normally closed

1

-KH1

OR valve

1

-SJ2

3/2-way valve with pushbutton actuator, normally open

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

3. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

4. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to 600 kPa (6 bar). • Allow the control system to run through several complete cycles.

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Exercise 11: Loading mesh baskets

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

5. How a latching circuit works –

Describe how the latching circuit works. A latching circuit is used to convert a brief signal into a continuous one. This type of latching circuit is used in the valve group -SJ1, -SJ2, -KH1 and -QM1. When the pushbutton actuator -SJ1 is pressed briefly, a continuous signal is sent to the output of valve -QM1. When the pushbutton actuator for the 3/2-way valve -SJ1 is pressed, the OR valve -KH1 opens to allow compressed air through. Since the 3/2-way valve -SJ2 is normally open, the compressed air actuates the control port 12 on the 3/2-way valve -QM1. This in turn actuates control port 14 on the 5/2-way valve -QM2. The directional control valve –QM2 switches and the piston rod on cylinder -MM1 advances. At the same time, the return line to the OR valve -KH1 ensures that valve -QM1 remains actuated. When 3/2-way valve -SJ2 is actuated, the self-latching loop is broken. There is no longer a signal at control port 12 on valve -QM1; the valve switches to its normal position, and control port 14 on 5/2way valve -QM2 and the return line to the OR valve are exhausted. Valve -QM2 switches to its normal position and the piston rod returns to its initial position. If both pushbutton actuators -SJ1 and -SJ2 are pressed at the same time, there will likewise be no signal at the output.

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Exercise 11: Loading mesh baskets

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Exercise 12: Actuating a sliding door Training aims After completing this exercise, you will: • Be able to combine logic operations. • Be familiar with the setup and function of a pneumatic proximity sensor. • Be able to distinguish between 5/2-way valves, and select and use them in accordance with specifications.

Description of the problem It needs to be possible to open and close a pneumatically driven sliding door from two different rooms using pushbutton actuators. In order to prevent operational errors in emergencies, there must be only one pushbutton actuator on each side of the door.

Layout

Sliding door

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Exercise 12: Actuating a sliding door

Description of the process 1. When the sliding door is in a defined end position, it can be moved to the other end position by pressing the pushbutton actuator. This opens or closes the door. 2. If the sliding door is not in one of the end positions, it is not possible to begin the opening or closing procedures.

• •

Parameters It must not be possible to start either of the processes unless the door is in one of the end positions. For safety reasons (to prevent risk of crushing), the pressure must be restricted to 300 kPa (3 bar).

1. 2. 3. 4. 5. 6.

Work assignments Describe how a pneumatic proximity sensor works. Complete the pneumatic circuit diagram for the sliding door control system. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

Additional exercise • What happens if the compressed air supply fails during a forward or return movement?

• • • • •

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Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

© Festo Didactic 541088

Exercise 12: Actuating a sliding door

1. How a pneumatic proximity sensor works

Pneumatic proximity sensor – circuit symbol and cutaway view

–

Describe how the pneumatic proximity sensor works. A 3/2-way stem-actuated valve is actuated by a switching jack with a spring return and a built-in permanent magnet. The ring magnet, which is mounted on the piston of a cylinder, reverses the direction of the switching jack. The 3/2-way stem-actuated valve switches and a control signal is generated at port 2 of the valve. Pneumatic proximity sensors sense the positions of the cylinder pistons. They are only used in pure pneumatic control systems. Pneumatic proximity sensors are mounted directly on the cylinder barrel.

Information Aligning the pneumatic proximity sensor 1. Move the cylinder to its end position. 2. Supply compressed air to port 1 until the pressure reaches 200 to 600 kPa (2 to 6 bar). 3. Move the proximity sensor until it reaches the switching point (compressed air signal at port 2). 4. Attach the proximity sensor to the cylinder.

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Exercise 12: Actuating a sliding door

2. Completing the pneumatic circuit diagram –

86

Complete the circuit diagram below for the sliding door. Add any missing circuit symbols. Label the individual components and enter the port designations.

© Festo Didactic 541088

Exercise 12: Actuating a sliding door

3. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

2

-BG1, -BG2

Proximity sensor, pneumatic

1

-RZ1, -RZ2

One-way flow control valve

1

-QM1

5/2-way bistable valve

1

-KH1

OR valve

2

-KH2, -KH3

AND valve

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • On the service unit, set the pressure to the level specified in the exercise instructions and switch on the compressed air supply. • Align the pneumatic proximity sensor and check that the control system is working properly. • Set the one-way flow control valves to match the specified retraction and advancing times of approx. 1 s. Use a stopwatch to do this. • Allow the control system to run through several complete cycles.

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Exercise 12: Actuating a sliding door

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The cylinder’s piston rod is retracted. Pneumatic proximity sensor -BG1 is actuated. There is a compressed air signal at one of the inputs of the AND valve -KH2. Step 1-2 When one of the two pushbutton actuators is pressed, the OR valve -KH1 issues an output signal. Thanks to AND valve -KH2, there is a signal at pilot port 14 on the 5/2-way bistable valve -QM1; the valve reverses direction. The cylinder’s piston rod advances. If the piston rod is in the advanced end position, pneumatic proximity sensor -BG2 is actuated. There is a compressed air signal at one of the inputs of the AND valve -KH3. Step 2-3 When one of the two pushbutton actuators is pressed, the OR valve -KH1 issues an output signal. Thanks to AND valve -KH3, there is a signal at pilot port 12 on the 5/2-way bistable valve -QM1; the valve reverses direction. The piston rod on the cylinder is retracted. If the piston rod is in the retracted end position, pneumatic proximity sensor -BG1 is actuated.

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Exercise 12: Actuating a sliding door

7. Additional exercise: Malfunction due to compressed air failure Information The control system's compressed air supply fails during a forward or return movement of the sliding door. What happens next? How can the control system be made operational again?

–

Describe the results of the compressed air failure. How can the control system be made operational again? The sliding door remains in its current position. When the compressed air supply is re-established, the sliding door continues moving in the direction it was moving in before the failure. This is because the signal is stored in the 5/2-way bistable valve -QM1. It is not possible to determine which direction the door was moving in. Care must be taken to ensure that the door's movement range is not obstructed before the compressed air is switched back on.

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Exercise 12: Actuating a sliding door

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Exercise 13: Feeding in wooden boards Training aims After completing this exercise, you will: • Be familiar with the NOT logic operation. • Be able to combine logic operations. • Be able to develop existing control systems further.

Description of the problem Wooden boards need to be fed into a machining process from a magazine. If the removal area is not clear, the system must prevent further wooden boards from being pushed out.

Layout

Stacking magazine

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Exercise 13: Feeding in wooden boards

Description of the process 1. The pushing out process can be started with a pushbutton actuator when the cylinder is in the retracted end position. The pushing cylinder only pushes a wooden board out of the magazine if the rolleractuated valve in the removal area signals that the removal position is NOT occupied. 2. If the removal area is clear, the piston rod on the cylinder moves to the advanced end position with controlled exhaust air, pushes the wooden board out and then immediately moves back to the retracted end position, again with controlled exhaust air.

•

Parameters A roller-actuated valve is used to check mechanically whether there is a wooden board in the removal area. The cylinder's exhaust air is controlled during advancing and retraction.

1. 2. 3. 4. 5.

Work assignments Complete the pneumatic circuit diagram. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

•

Additional exercise • What changes would you need to make to the control system if it were only permitted to start the pushing out process when there is at least one wooden board in the magazine AND the removal position is clear?

• • • • •

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Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

© Festo Didactic 541088

Exercise 13: Feeding in wooden boards

1. Completing the pneumatic circuit diagram –

Complete the circuit diagram below for the stacking magazine. Add any missing circuit symbols. Label the individual components and enter the port designations.

Training note As an alternative, you can use a 3/2-way valve with selector switch in the control system if you wish to simulate whether or not the removal area is clear.

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Exercise 13: Feeding in wooden boards

2. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

2

-BG1, -BG2

Proximity sensor, pneumatic

2

-RZ1, -RZ2

One-way flow control valve

1

-QM1

5/2-way bistable valve

2

-KH1, -KH2

AND valve

1

-BG3

3/2-way roller-actuated valve, normally open

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

3. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

4. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • For the first test run, reduce the pressure on the filter regulating valve (service unit) to 350 kPa (3.5 bar). • Switch on the compressed air supply at the service unit. • Check that the control system is working correctly. • Increase the pressure to 600 kPa (6 bar). • Allow the control system to run through several complete cycles.

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Exercise 13: Feeding in wooden boards

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

5. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position Compressed air is present. The piston on the cylinder is in the retracted end position. Pneumatic proximity sensor -BG1 is actuated and switched to the "allow flow" position. The piston rod chamber is pressurized. Step 1-2 If there is a wooden board in the removal area, the 3/2-way roller-actuated valve -BG3 is actuated. The AND valve -KH1 does not issue an output signal indicating that the direction of the 5/2-way bistable valve -QM1 cannot be reversed. If the removal area is clear, the 3/2-way roller-actuated valve -BG3 is not actuated. The AND valve -KH1 issues an output signal. When the pushbutton actuator for the 3/2-way valve -SJ1 is pressed, the AND valve -KH2 issues an output signal. There is a signal at pilot port 14 on the 5/2-way bistable valve -QM1. The 5/2-way bistable valve reverses direction; the cylinder’s piston rod advances.

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Exercise 13: Feeding in wooden boards

Step 2-3 Pneumatic proximity sensor -BG2 is actuated and switches to the "allow flow" position. There is a signal at pilot port 12 on the 5/2-way bistable valve. The 5/2-way bistable valve -QM1 reverses direction; the cylinder’s piston rod retracts. Pneumatic proximity sensor -BG1 is actuated and switches to the "allow flow" position. Step 3-1 As Step 1.

6. Additional exercise: Adapting the control system –

The control system needs to be modified so that the pushing out process can only start when there are wooden boards in the magazine AND the removal position is clear at the same time. Describe the modifications required to the control system in order to fulfill this requirement. An extra sensor (e.g. a roller-actuated valve) needs to be used in order to sense the wooden boards in the magazine. The "Wooden boards found" output signal from this sensor is linked to the "Removal position clear" output signal from the 3/2-way roller-actuated valve -BG3 by a second AND valve. The output signal from this AND valve is sent to one input on AND valve -KH1.

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Exercise 14: Pressing drinks cans Training aims After completing this exercise, you will: • Be familiar with the setup and function of a pressure sequence valve. • Be able to set up pressure-dependent control systems.

Description of the problem At a recycling plant, drinks cans are pressed into small packages to save on storage space. The pressing process is triggered by a pushbutton actuator. The return stroke can be triggered by another pushbutton actuator. The pressing process should only begin if there is sufficient pressure in the system.

Layout

Can press

Note Protective grilles that are required in actual practice are not shown here.

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Exercise 14: Pressing drinks cans

1. 2.

3.

4. 5.

• • • •

98

Description of the process The drinks cans are inserted in the press by hand. When the preset pressure is reached, a pressure sequence valve switches and releases the compressed air into the control system. The control system must not be able to function at pressures below 450 kPa (4.5 bar). It must be impossible to start the pressing process unless the pressing cylinder is in the top end position. When this is the case, it must be possible to start the pressing process using a start button. The piston rod on the pressing cylinder moves to the advanced end position, or up to the stop point defined by the material. The return stroke is triggered by either another proximity sensor or a pushbutton actuator. The pressed drinks cans are pushed out of the system at the side by a second cylinder.

Parameters The initial position of the pressing cylinder is the retracted end position. The pushing cylinder for the pressed packages is not taken into account. The pressing procedure should not start until the system pressure exceeds 450 kPa (4.5 bar). The return stroke can be triggered by hand if the pressing cylinder cannot reach its advanced end position due to the number of drinks cans it has pressed.

1. 2. 3. 4. 5. 6.

Work assignments Describe how a pressure sequence valve works. Complete the pneumatic circuit diagram for the can press. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

© Festo Didactic 541088

Exercise 14: Pressing drinks cans

1. How a pressure sequence valve works

Pressure sequence valve – circuit symbol and cutaway view

a) Describe how a pressure sequence valve works. When the pressure at pilot port 12 exceeds a predefined level, the actuated 3/2-way valve switches; there is compressed air at working port 2. The 3/2-way valve switches back when the pressure at pilot port 12 drops below the set level.

b) What applications is the pressure sequence valve used for? The pressure sequence valve is used when a pressure-dependent signal is required to switch a control system again. Examples of applications: • Building up a clamping pressure for cylinders • Dropping below the operating pressure

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Exercise 14: Pressing drinks cans

2. Completing the pneumatic circuit diagram –

100

Complete the circuit diagram below for the can press. Add any incomplete circuit symbols.

© Festo Didactic 541088

Exercise 14: Pressing drinks cans

3. Completing the equipment list –

Complete the equipment list. Enter the quantity and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-BG1, -BG2

Proximity sensor, pneumatic

1

-RZ1, -RZ2

One-way flow control valve

1

-QM1

5/2-way bistable valve

1

-KH1

AND valve

1

-KH2

OR valve

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-QN1

Pressure sequence valve

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • Switch on the compressed air supply at the service unit. • Align the pneumatic proximity sensors. • Set the pressure sequence valve so that it switches at the required operating pressure.

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Exercise 14: Pressing drinks cans

• •

Set the one-way flow control valves to match the specified retraction and advancing times of approx. 1 s. Use a stopwatch to do this. Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position Compressed air is present. The required pressure is preset at the pressure regulator on the service unit. The required pressure is set at the pressure sequence valve. The double-acting cylinder is retracted. Pneumatic proximity sensor -BG1 is actuated. Step 1-2 The pushbutton actuator for the 3/2-way valve -SJ1 is pressed. This fulfills the condition for the AND valve -KH1. The 5/2-way bistable valve -QM1 is switched. The piston rod on the double-acting cylinder -MM1 advances.

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Exercise 14: Pressing drinks cans

Step 2-3 Pneumatic proximity sensor -BG2 is actuated. The 5/2-way bistable valve -QM1 is switched back by the OR valve -KH2. Alternatively, this procedure can be triggered by the pushbutton actuator for the 3/2-way valve -SJ2. The 5/2-way bistable valve is switched back by the OR valve -KH2. The piston rod on the double-acting cylinder moves back to its initial position. The process is complete when the pneumatic proximity sensor -BG1 is actuated when the pushbutton actuator for the 3/2-way valve -SJ1 has already been released.

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Exercise 14: Pressing drinks cans

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Exercise 15: Stamping valve housings Training aims After completing this exercise, you will: • Be familiar with the setup and function of a pressure regulator. • Be able to set up pressure-dependent control systems.

Description of the problem Prototypes of aluminum valve housings need to be stamped with identification codes. The housings are inserted in the stamping machine by hand. The operating pressure must be at least 400 kPa (4 bar) in order to ensure that the identification codes are easily legible. However, the pressure at the stamping cylinder must not exceed 500 kPa (5 bar) otherwise the housing may be damaged during stamping. There is one pushbutton actuator each to actuate the forward and return strokes. The stamping cylinder's retracted end position is sensed by a pneumatic proximity sensor.

Layout

Note Safety devices that are required in actual practice are not shown. Stamping machine

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Exercise 15: Stamping valve housings

1. 2. 3. 4. 5.

•

Parameters The procedure can only begin if the cylinder's piston rod is in the retracted end position. In addition to this, the control system should not start up until the operating pressure exceeds 400 kPa (4 bar). The return stroke is triggered manually.

1. 2. 3. 4. 5. 6. 7.

Work assignments Describe how a pressure regulator works. Complete the pneumatic circuit diagram for the stamping machine. Complete the equipment list. Set up the control system. Check the setup of the control system. Describing the control system sequence Describe how the one-way flow control valve installed parallel to the pressure regulator works.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

• •

106

Description of the process The valve housing is inserted in the stamping machine by hand. When the preset pressure is reached, a pressure sequence valve switches and releases the compressed air into the control system. The stamping procedure begins when the stamping cylinder is in the retracted end position and a pushbutton actuator is pressed. The cylinder’s piston rod advances and remains in this position. The procedure is ended by pressing a second pushbutton actuator, after which the piston rod on the cylinder moves back to the retracted end position. The stamped valve housing is removed by hand.

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Exercise 15: Stamping valve housings

1. How a pressure regulator works

Pressure regulator – circuit symbol and cutaway views

–

Describe how a pressure regulator works. The inlet pressure (primary pressure) at the pressure regulator must always be higher than the outlet pressure (secondary pressure). The pressure regulation itself is performed by a diaphragm. The outlet pressure acts on one side of the diaphragm, the force of a spring on the other. The spring force can be set using an adjusting screw. If the pressure on the secondary side increases, e.g. during a load change at the cylinder, the diaphragm is pressed against the spring and the outlet cross-sectional area at the valve seat is reduced or closed. The valve seat of the diaphragm opens and the compressed air can escape into the atmosphere through the relief ports in the housing. If the pressure on the secondary side decreases, the spring force opens the valve. Regulating the air pressure to the preset operating pressure therefore means constantly opening and closing the valve seat. This is done by the air volume flowing through the regulator.

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Exercise 15: Stamping valve housings

2. Completing the pneumatic circuit diagram –

108

Complete the pneumatic circuit diagram below for the stamping machine. Add any missing circuit symbols. Label the individual components and enter the port designations.

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Exercise 15: Stamping valve housings

3. Completing the equipment list –

Create an equipment list by entering the required devices in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-BG1

Proximity sensor, pneumatic

1

-RZ1, -RZ2

One-way flow control valve

1

-QN2

Pressure regulator

1

-QM1

5/2-way bistable valve

1

-KH1

AND valve

1

-QN1

Pressure sequence valve

2

-SJ1, -SJ2

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

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Exercise 15: Stamping valve housings

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • Switch on the compressed air supply at the service unit. • Align the pneumatic proximity sensor. • Set the maximum pressure for the stamping cylinder using the pressure regulator. • Set the pressure sequence valve so that it switches at the required operating pressure. • Set the one-way flow control valve to maintain an advancing time of approx. 1 s. Use a stopwatch to do this. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The double-acting cylinder -MM1 is in the retracted end position. Pneumatic proximity sensor -BG1 is actuated. The pressure sequence valve -QN1 switches at an operating pressure of 400 kPa (4 bar). The maximum pressure for the cylinder is limited to 500 kPa (5 bar) on the pressure regulator -QN2. Step 1-2 The pushbutton actuator for the 3/2-way valve -SJ1 is pressed, thus fulfilling the conditions for the AND valve -KH1 and switching the 5/2-way bistable valve -QM1. The piston rod on cylinder -MM1 advances at low pressure.

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Exercise 15: Stamping valve housings

Step 2-3 When the pushbutton actuator for the 3/2-way valve -SJ2 is pressed, the 5/2-way bistable valve -QM1 switches back. The piston rod on cylinder -MM1 is retracted at full operating pressure. If the retracted end position, pneumatic proximity sensor -BG1 is actuated. The system has returned to its initial position.

7. How the one-way flow control valve installed parallel to the pressure regulator works –

Describe how the one-way flow control valve installed parallel to the pressure regulator works. The one-way flow control valve -RZ1 is used as a bypass for the pressure regulator. The flow control valve is screwed completely shut. The compressed air can flow through the check valve when the cylinder is being retracted; pressure regulator -QN2 is bypassed in this direction of flow.

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Exercise 15: Stamping valve housings

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Exercise 16: Mounting locking clips Training aims After completing this exercise, you will: • Be able to set up pressure-dependent control systems. • Be able to analyze and optimize existing control systems.

Description of the problem An automatic assembly machine is used to mount locking clips on plug connector housings. Up until now, the pressure has been set using a pressure regulator on the automatic assembly machine. This method repeatedly caused malfunctions in the mounting process. A test setup needs to be built to investigate the mounting process. Each mounting procedure is triggered manually. The control system needs to be modified so that it only works when the pressure exceeds a certain level.

Layout

Automatic assembly machine for plug connector housings – Feeding in locking clips

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Exercise 16: Mounting locking clips

1. 2. 3. 4.

• • •

Description of the process The procedure should begin at the push of a pushbutton actuator when the mounting cylinder's piston rod is in the retracted end position. The piston rod needs to move to the advanced end position with minimal force. When it reaches this position, the piston rod will actuate a limit valve. Once it has done this, the piston rod needs to return to the retracted end position.

Parameters The pressure at the working port of the mounting cylinder must be 300 kPa (3.0 bar) in order to ensure that the locking clips are mounted securely. I must be impossible to start the procedure if the pressure is above 400 kPa (4.0 bar). The return stroke of the mounting cylinder starts automatically after it has reached its advanced end position.

1. 2. 3. 4. 5. 6.

Work assignments Analyze the pneumatic circuit diagram for the automated assembly machine. Complete the pneumatic circuit diagram. Take the parameters into consideration. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

1. Analyzing the pneumatic circuit diagram –

Analyze the following circuit diagram and check whether it is suitable for the problem described above. The circuit diagram is not suitable. For example, the return stroke does not start automatically. There is also a risk of the working pressure in the cylinder supply air being set incorrectly on pressure regulator -QN3, which would result in damage to the clips.

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Exercise 16: Mounting locking clips

Pneumatic circuit diagram

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Exercise 16: Mounting locking clips

2. Completing the pneumatic circuit diagram –

116

Complete the pneumatic circuit diagram for the automated assembly machine. Take all the specified parameters into consideration. Label the individual components and enter the missing port designations.

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Exercise 16: Mounting locking clips

3. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

1

-BG1

Proximity sensor, pneumatic

2

-RZ1, -RZ2

One-way flow control valve

1

-QM2

5/2-way bistable valve

1

-BG2

Proximity sensor, pneumatic

1

-QM1

3/2-way valve, normally open

2

-KH1, -KH2

AND valve

1

-QN2

Pressure sequence valve

1

-QN1

Pressure regulator

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

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Exercise 16: Mounting locking clips

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • Switch on the compressed air supply at the service unit. • Align the pneumatic proximity sensor. • Set the pressure regulator. • Set the pressure sequence valve so that it switches at the required operating pressure. • Set the one-way flow control valve to maintain an advancing time of approx. 1 s. Use a stopwatch to do this. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The piston rod on the double-acting cylinder is in the retracted end position. Pneumatic proximity sensor -BG1 is actuated. Compressed air is present. The required pressure is set at the pressure regulator and the pressure sequence valve. Step 1-2 The pushbutton actuator for the 3/2-way valve -SJ1 is pressed and the pneumatic proximity sensor BG1 is actuated, thus fulfilling the conditions for the first AND valve -KH1. •

118

If the pressure is lower than the pressure threshold set at the pressure sequence valve -QN2, the 3/2-way valve -QM1 is normally open. The conditions for the second AND valve -KH2 are fulfilled, and the 5/2-way bistable valve -QM2 switches to the operating position. The piston rod on the double-acting cylinder advances.

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Exercise 16: Mounting locking clips

•

If the pressure is higher than the pressure threshold set at the pressure sequence valve -QN2, the 3/2-way valve -QM1 switches to the operating position. The conditions for the second AND valve -KH2 are not fulfilled, and the 5/2-way bistable valve -QM2 does not switch to the operating position. The piston rod on the double-acting cylinder does not advance.

Step 2-3 Pneumatic proximity sensor -BG2 is actuated and switches to the operating position. The 5/2-way bistable valve -QM2 is switched. The piston rod on the double-acting cylinder returns to the initial position. The procedure is complete when pneumatic proximity sensor -BG1 is actuated.

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Exercise 16: Mounting locking clips

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Exercise 17: Labeling paint buckets Training aims After completing this exercise, you will: • Be familiar with the setup and function of a pneumatic timer. • Be able to set up time-dependent control systems. • Be able to create and describe the GRAFCET.

Description of the problem A gluing machine is used to label paint buckets. The gluing procedure is triggered when a pushbutton actuator on the machine is pressed. The label must be pressed on for 10 seconds in order for the adhesive to take effect. The system is ready to start when the piston on the pressing cylinder is in the retracted end position.

Layout

Labeling machine

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Exercise 17: Labeling paint buckets

1. 2. 3. 4.

• • •

Parameters Since the label needs to be glued to the paint bucket with minimal force, the working pressure needs to be adjustable. The cylinder's piston rod must be retracted as quickly as possible. The working pressure must be adjustable within a range of between 300 and 600 kPa (3 and 6 bar). The pressure needs to be displayed on a pressure gauge upstream of the cylinder.

1. 2. 3. 4. 5. 6. 7.

Work assignments Describe how a pneumatic timer works. Complete the pneumatic circuit diagram. Create an equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system. Create the GRAFCET for the process.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

•

122

Description of the process The procedure should begin at the push of a pushbutton actuator when the cylinder's piston rod is in the retracted end position. The piston rod needs to move to the advanced end position with minimal force and speed, then remain there for a set period of time. Once it has done this, the piston rod needs to return quickly to the retracted end position. The advancing pressure needs to be displayed on a pressure gauge.

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Exercise 17: Labeling paint buckets

1. How a pneumatic timer works

Pneumatic time – circuit symbol and photo

–

Describe how a pneumatic timer works and enter the most important technical data for it in the table. The pneumatic timer switches the inlet pressure at port 1 to 2 after a set period of time. If the compressed air supply at port 1 is interrupted, working port 2 is depressurized again. The pneumatic timer is reset automatically after 200 ms. The time delay can be adjusted steplessly using an adjusting knob.

Technical data Pressure range

200 to 600 kPa (2 to 6 bar)

Switch-on pressure

>160 kPa (1.6 bar)

Standard nominal flow rate

50 l/min

Time delay

2 to 30 s (adjustable)

Setting accuracy

±0.6 s

Resetting interval

>200 ms

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Exercise 17: Labeling paint buckets

2. Completing the pneumatic circuit diagram –

124

Complete the circuit diagram below. Add any incomplete circuit symbols. Enter the missing port designations.

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Exercise 17: Labeling paint buckets

3. Completing the equipment list –

Complete the equipment list. Enter the identification of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

2

-BG1, -BG2

Proximity sensor, pneumatic

1

-PG1

Pressure gauge

1

-QM2

Quick-exhaust valve

1

-RZ1

One-way flow control valve

1

-QM1

5/2-way bistable valve

1

-KH1

AND valve

1

-KH2

Timer, pneumatic

1

-QN1

Pressure regulator

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Equipment list

4. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

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Exercise 17: Labeling paint buckets

5. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • Switch on the compressed air supply at the service unit. • Align the pneumatic proximity sensors. • Set the maximum pressure for the pressing cylinder using the pressure regulator. • Set the pressing time using the pneumatic timer. • Set the one-way flow control valve to maintain an advancing time of approx. 1 s. Use a stopwatch to do this. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

6. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The double-acting cylinder -MM1 is in the retracted end position. Pneumatic proximity sensor -BG1 is actuated. Compressed air is present. The working pressure is set on the pressure regulator -QN1. Step 1-2 The pushbutton actuator for the 3/2-way valve -SJ1 is pressed. This fulfills the conditions for the AND valve -KH1, and the 5/2-way bistable valve -QM1 switches to the operating position. The piston rod on the double-acting cylinder -MM1 advances with flow control.

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Exercise 17: Labeling paint buckets

Step 2-3 Pneumatic proximity sensor -BG2 is actuated. As such, compressed air is supplied to the pneumatic timer -KH2, and it switches after a preset time. The 5/2-way bistable valve -QM1 is switched back. The piston rod on the double-acting cylinder -MM1 returns to the initial position without flow control. The piston chamber is exhausted via the quick-exhaust valve –QM2. The process is complete when the pneumatic proximity sensor -BG1 is actuated and the pushbutton actuator for the 3/2-way valve -SJ1 has been released.

7. Creating a GRAFCET for the process a) Create a GRAFCET chart for process described above.

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Exercise 17: Labeling paint buckets

b) Describe the steps and the transition conditions. Step 1 is the starting step. The transition condition from starting step 1 to step 2 is fulfilled when the proximity sensor -BG1 is actuated AND pushbutton -SJ1 is pressed. As soon as step 2 is active, the drive -MM1 is actuated. Even when step 2 is no longer active, the drive remains actuated until the actuation command is rescinded by another action. The transition condition from step 2 to step 3 is fulfilled when proximity sensor -BG2 is actuated. As soon as step 3 is active, the specified time of 10 seconds starts to count down. The transition condition from step 3 to step 4 is fulfilled when this time period has elapsed. As soon as step 4 is active, the actuation command for the drive -MM1 is rescinded. The transition condition from step 4 to step 1 is fulfilled when proximity sensor -BG1 is actuated. The line with the upward pointing arrow indicates the return to the starting step.

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Exercise 18: Cleaning workpieces Training aims After completing this exercise, you will: • Be able to set up control systems with oscillating movements. • Be able to use a time delay valve in accordance with parameters.

Description of the problem A mesh basket of workpieces needs to be raised and lowered in the cleaning bath. The procedure is started by pressing a pushbutton actuator.

Layout

Automatic washing system

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Exercise 18: Cleaning workpieces

Description of the process 1. The procedure begins when a pushbutton actuator is pressed and the lifting cylinder's piston rod is retracted. 2. The piston rod on the cylinder of the lifting system advances to its advanced end position. The piston rod then moves back to the mid-position, and then back to the advanced end position. This movement continues until the pneumatic timer interrupts the procedure. 3. When this happens, the cylinder's piston rod moves back to the retracted end position.

130

• • •

Parameters A roller-actuated valve must be used to sense the retracted end position. The advancing and retracting speeds of the piston rod must be adjustable. The time for the cleaning procedure should be set to 20 seconds.

1. 2. 3. 4. 5. 6. 7.

Work assignments Convert a 5/2-way bistable valve to make a 3/2-way bistable valve. Set the retracting and advancing speeds for the cylinder. Complete the pneumatic circuit diagram for the automatic cleaning system. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system.

• • • • •

Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

© Festo Didactic 541088

Exercise 18: Cleaning workpieces

1. Converting a 5/2-way bistable valve

Circuit symbol for a 5/2-way bistable valve

–

Convert a 5/2-way bistable valve to make a 3/2-way bistable valve. Describe what you need to do. Output 4 needs to be sealed using a blanking plug.

2. Setting the retracting and advancing speeds –

The speed of the piston can be adjusted using supply air flow control, exhaust air flow control or a combination of both. The cylinder in the washing system works with the piston rod moving vertically downwards; the load is a pulling load. What type of flow control should you use? Exhaust air flow control on the piston side delays the escape of the exhaust air. The cylinder piston only moves when the force on the piston rod side of the cylinder is greater than the force on the piston surface plus the weight force of the load. Exhaust air flow control only acts as a time delay in this situation. To enable the piston to move out of its end position earlier in this configuration, no one-way flow control valve is installed on the piston side. However, supply air flow control is additionally used on the piston rod side so that the retracting speed can still be adjusted.

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Exercise 18: Cleaning workpieces

3. Completing the pneumatic circuit diagram –

132

Complete the circuit diagram below. Add any missing circuit symbols. Label the individual components and enter the port designations.

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Exercise 18: Cleaning workpieces

4. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-MM1

Cylinder, double-acting

2

-RZ1, -RZ2

One-way flow control valve

1

-QM2

5/2-way bistable valve, pneumatic

1

-QM1

3/2-way bistable valve, pneumatic

2

-BG2, -BG3

Proximity sensor, pneumatic

1

-BG1

3/2-way roller-actuated valve, normally closed

1

-SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-KH1

Time delay valve

1

-KH2

OR valve

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Note A pneumatic 5/2-way bistable valve is converted to make a pneumatic 3/2-way bistable valve.

5. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

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Exercise 18: Cleaning workpieces

6. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • Switch on the compressed air supply at the service unit. • Align the pneumatic proximity sensors. • Set the cleaning time using the pneumatic timer. • Check that the control system is working correctly. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

7. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The piston rod of the cylinder -MM1 is in the retracted end position and actuates the 3/2-way rolleractuated valve -BG1. The 5/2-way bistable valve -QM2 is in the right-hand switching position. The 3/2way bistable valve -QM1 (signal latch) is in the left-hand switching position. The pneumatic timer is set to 20 s as specified. Step 1-2 The pushbutton actuator -SJ1 is pressed, switching the signal latch -QM1. There is compressed air at the input of the pneumatic timer -KH1. The actuated 3/2-way roller-actuated valve -BG1 and the OR valve -KH2 switch the 5/2-way bistable valve -QM2; the piston rod on the cylinder advances. Nothing happens when the cylinder moves over the mid-position pneumatic proximity sensor -BG3, as this actuates the same control port on the actuator.

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Exercise 18: Cleaning workpieces

Step 2-3 When the advanced end position is reached, pneumatic proximity sensor-BG2 is actuated. The actuator (5/2-way bistable valve) switches. The piston rod is retracted and actuates the mid-position pneumatic proximity sensor -BG3. Step 3-4 The actuation of the mid-position pneumatic proximity sensor -BG3 reverses the direction of the piston rod again. The switching procedure takes just a few milliseconds, so the rod does not move over the trip cam at pneumatic proximity sensor -BG3. Step 4-5 See step 2-3. Oscillating movement The piston rod oscillates back and forth between pneumatic proximity sensors -BG2 and -BG3 until the set time on the pneumatic timer -KH1 elapses. Steps n-2 to n Once the pneumatic timer has switched, the signal latch -QM1 is switched back. The pneumatic proximity sensor -BG3 and the 3/2-way roller-actuated valve -BG1 are no longer supplied with compressed air. The piston rod moves to its initial position (retracted end position). The process is complete when the 3/2-way roller-actuated valve -BG1 is actuated and the pushbutton actuator for valve -SJ1 has been released.

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Exercise 18: Cleaning workpieces

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Exercise 19: Pressing product labels into place Training aims After completing this exercise, you will: • Be able to analyze and set up control systems with two cylinders.

Description of the problem Product labels are pressed into valve housings at a machining station. First, the product labels are placed in recesses in the valve housing. A pressing cylinder then presses them into place. The valve housing clamping procedure is triggered by a pushbutton actuator. Once clamping is complete, the pressing procedure begins. Once the pressing cylinder has reached its advanced end position, both cylinders should return.

Layout

Note Safety devices that are required in actual practice are not shown. Pressing system for product labels

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Exercise 19: Pressing product labels into place

1. 2. 3. 4. 5.

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Parameters A single-acting cylinder must be used to clamp the valve housing. The clamping pressure must be at least 400 kPa (4 bar). A roller-actuated valve must be used to sense whether the piston rod on the clamping cylinder has reached its advanced end positions. A double-acting cylinder must be used as the pressing cylinder. The forward stroke speeds of both the clamping and the pressing cylinders must be adjustable.

1. 2. 3. 4. 5. 6.

Work assignments Complete the pneumatic circuit diagram for the pressing system. Complete the equipment list. Set up the control system. Check the setup of the control system. Describe the working sequence for the control system. Describe how the failure of a proximity sensor signal would affect the control system.

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Work aids Books of tables Textbook: Fundamentals of pneumatics and electropneumatics Component data sheets FluidSIM® P design and simulation software WBT: Pneumatics

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Description of the process A product label is placed in the recess. The clamping and pressing procedure is started by pressing a pushbutton actuator. A limit valve should be used to sense whether the piston rod on the clamping cylinder has reached the correct position. The piston rod on the pressing cylinder must not advance until the piston rod on the clamping cylinder has reached its advanced end position and the clamping pressure has built up to the required level. Once the product label has been pressed into place, the piston rods on both cylinders retract.

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Exercise 19: Pressing product labels into place

1. Completing the pneumatic circuit diagram –

Complete the circuit diagram below. Add any missing circuit symbols. Label the individual components and enter the port designations.

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Exercise 19: Pressing product labels into place

2. Completing the equipment list –

Complete the equipment list. Enter the quantity, identification and designation of the required components in the table below.

Quantity

Identification

Designation

1

-H1MM1

Cylinder, double-acting

1

-U1MM1

Cylinder, single-acting

2

-U1RZ1, -H1RZ1

One-way flow control valve

1

-H1QM1

5/2-way bistable valve, pneumatic

1

-U1QM1

3/2-way bistable valve, pneumatic

2

-H1BG1, -H1BG2

Proximity sensor, pneumatic

1

-U1BG1

3/2-way roller-actuated valve, normally closed

1

-U1SJ1

3/2-way valve with pushbutton actuator, normally closed

1

-U1QN1

Pressure sequence valve

2

-U1KH1, -H1KH1

AND valve

1

-XM1

Distributor block

1

-AZ1

On-off valve with filter regulating valve

1

—

Compressed air source

Training notes A function must be assigned to each of the circuits in a system. This information – e.g. clamping, mounting, drilling or transporting – is represented by a code letter in front of the circuit designation. In this pressing system, the "clamping" circuit has been assigned the identification "U" and the "pressing" circuit the identification "H".

Note A pneumatic 5/2-way bistable valve is converted to make a pneumatic 3/2-way bistable valve.

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3. Setting up the control system Observe the following points when setting up the control system: • Use the circuit diagram. • Designate the components. • Lay the compressed air tubing using the shortest routes possible. • Push the compressed air tubing into the push-in connector as far as it will go. • Mark the connected compressed air tubing on the circuit diagram.

4. Double-checking the control system setup Observe the following points when commissioning the control system: • Check all the tubing connectors. • Switch on the compressed air supply at the service unit. • Align the pneumatic proximity sensors. • Set the pressure sequence valve. • Set the one-way flow control valves to an advancing time of approx. 1 s. Use a stopwatch to do this. • Check that the control system is working correctly. • Allow the control system to run through several complete cycles.

Risk of injury when switching on the compressed air! Cylinders may advance and retract automatically. Risk of injury if compressed air tubing slips off! If compressed air tubing slips off, shut off the compressed air supply immediately.

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Exercise 19: Pressing product labels into place

5. Describing the control system sequence –

Describe the individual steps of the control system sequence. Initial position The system is pressurized. In the initial position, the piston rods on both cylinders are in their retracted end positions. The piston on the double-acting cylinder -H1MM1 actuates the pneumatic proximity sensor -H1BG1, causing it to switch into the "allow flow" direction. The actuators -U1QM1 and -H1QM1 (3/2-way and 5/2-way bistable valves) move to the right-hand switching position. Step 1-2 When the pushbutton actuator -U1SJ1 is pressed, the condition for the AND valve -U1KH1 is fulfilled. The 3/2-way bistable valve -U1QM1 switches. The piston rod on the single-acting cylinder -U1MM1 advances with supply air control. Step 2-3 When the piston rod on single-acting cylinder -U1MM1 reaches its advanced end position, the rolleractuated valve -U1BG1 is actuated. When the required clamping pressure is reached, the pressure sequence valve -U1QN1 issues an output signal. The condition for the AND valve -H1KH1 is fulfilled. The 5/2-way bistable valve -H1QM1 switches. The piston rod on the double-acting cylinder -H1MM1 moves to the advanced end position with exhaust air control, thus actuating the pneumatic proximity sensor -H1BG2. Step 3-4 The 5/2-way bistable valve -H1QM1 and the 3/2-way bistable valve -U1QM1 switch. The piston rods on both cylinders retract. The procedure is complete when the piston on the double-acting cylinder -H1MM1 actuates the pneumatic proximity sensor -H1BG1.

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Exercise 19: Pressing product labels into place

Note The piston rod on the single-acting cylinder -U1MM1 returns slightly earlier than that of the doubleacting cylinder -H1MM1. This is because the control signals at pilot ports 14 and 12 on the 5/2-way bistable valve -H1QM1 overlap. The 5/2-way bistable valve -H1QM1 cannot switch until the singleacting cylinder -U1MM1 has left its advanced end position and the 3/2-way roller-actuated valve -U1BG1 is no longer actuated, because the AND valve -H1KH1 will then no longer switch.

6. Failure of a proximity sensor signal –

What happens if the pneumatic proximity sensor -H1BG2 on the pressing cylinder fails or is knocked out of alignment? Write down the results of these events. The pneumatic proximity sensor -H1BG2 is not actuated, so the 5/2 and 3/2-way bistable valves are not reset. The piston rod on the cylinder does not move back to the retracted end position. As a result, the proximity sensor -H1BG1 is not actuated, and it becomes impossible to start up the control system.

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