Electropneumatics Text

8/12/2019 Electropneumatics Text

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095011 GB

Fundamentals of Electropneumatics

Collection of Transparencies

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33

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Order No.: 095011Description: EL-PN.FOLIEN-GSDesignation: D:OT-TP201-GBEdition: 02/2000Author: Frank EbelGraphics: Doris SchwarzenbergerLayout: 10.05.2000, Beatrice Huber

Festo Didactic GmbH & Co., D-73770 Denkendorf, 2000Internet: www.festo.com/didactice-mail: [email protected]

The copying, distribution and utilization of this document as well as thecommunication of its contents to others without expressed authorization isprohibited. Offenders will be held liable for the payment of damages. All rightsreserved, in particular the right to carry out patent, utility model or ornamental

design registration.


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Foreword

Festo Didactic GmbH & Co. Electropneumatics

The Collection of Transparencies is conceived for the basic material of the TP200Electropneumatic Technology Package. The transparency collection and technologypackage form part of the The Learning System for Automation from Festo DidacticGmbH & Co.

The transparencies are designed from a didactical and methodological point of view.For each transparency, there is a short accompanying text that provides the speakerwith a quick overview of the contents. More information you will find in the textbookElectropneumatics.

Physical fundamentals of electropneumatics Function and application of electropneumatic components Designation and drawing of electropneumatic symbols Drawing of pneumatic and electrical circuit diagrams in accordance with

standards Presentation of motion sequences and switching conditions Direct and indirect manual controls Direct and indirect direction-dependent controllers Logical AND/OR functions Pressure-dependent controls with pressure switches Troubleshooting in simple electropneumatic control systems

The text pages contain a complete picture of the transparency with some additionalexplanations and items which the speaker can mark on the transparency duringinstruction.

The advantages of this concept are: The speaker can add to the transparencies step-by-step during instruction. Instruction is livelier. The accompanying texts provided reduce preparation time.

The enclosed CD-ROM contains all the overhead transparencies and accompanyingtext of this edition in an electronically presentable form in the filesElectropneumatics _ transparencies.pdf and Electropneumatics _text.pdf. Inaddition to the screen presentation, which can be made in any order, the contentscan be printed out and text and graphics can be used for your own trainingpreparations, insofar as the functionality of the required Adobe

Acrobat

Reader

permits this. This freely distributable software is available on the CD-ROM in thecurrently valid English version for Windows 95/98/NT for installation in the directoryAcrobat_Reader. Please start the file rs405eng.exe and follow the subsequentdialogue.

Syllabus

New!Electronic presentation


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Contents


System ElementsElements of a Control Chain __________________________________ Transparency 1

Pneumatic ComponentsSingle-Acting Cylinder _______________________________________ Transparency 2Double-Acting Cylinder ______________________________________ Transparency 3Non-return, Flow Control and Pressure Control Valves_____________ Transparency 4Pressure Regulating Valve____________________________________ Transparency 5One-Way Flow Control Valve __________________________________ Transparency 6Quick Exhaust Valve_________________________________________ Transparency 7

Electropneumatic ComponentsConversion of Electrical Signals into Pneumatic Signals ___________ Transparency 8Conversion of Pneumatic Signals into Electrical Signals ___________ Transparency 9Switching Symbols for Valves________________________________ Transparency 10Directional Control Valves: Ports and Switching Positions_________ Transparency 11Function Principle of a Solenoid Coil __________________________ Transparency 122/2-Way Solenoid Valve without Pilot Control __________________ Transparency 13Solenoid Valves with Pilot Control ____________________________ Transparency 143/2-Way Single Solenoid Valve with Pilot Control _______________ Transparency 155/2-Way Single Solenoid Valve with Pilot Control _______________ Transparency 16

5/2-Way Double Solenoid Valve with Pilot Control_______________ Transparency 175/3-Way Solenoid Valve ____________________________________ Transparency 18

Electrical ComponentsPower Supply Units ________________________________________ Transparency 19Switching Contacts and Types of Actuation_____________________ Transparency 20Types of Actuation of Switching Elements______________________ Transparency 21Switching Symbols for Solenoid Coils and Relays________________ Transparency 22The Relay ________________________________________________ Transparency 23Magnetic Proximity Switches (Reed Switches) __________________ Transparency 24Electrical Output Devices____________________________________ Transparency 25

Logic FunctionsThe AND Logic Function _____________________________________ Transparency 26The OR Logic Function ______________________________________ Transparency 27


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Contents


Electropneumatic Controller Control Chain _____________________________________________ Transparency 28Direct Actuation of a Single-Acting Cylinder ____________________ Transparency 29Indirect Actuation of a Double-Acting Cylinder __________________ Transparency 30Electrical Memory Circuit Dominant Set ______________________ Transparency 31Electrical Memory Circuit Dominant Reset ____________________ Transparency 32Electropneumatic Memory Circuit with Double Solenoid Valve_____ Transparency 33Stroke-Dependent Control___________________________________ Transparency 34Pressure-Dependent Control_________________________________ Transparency 35

Circuit Diagram DesignThe Electropneumatic Circuit Diagram _________________________ Transparency 36Circuit Diagram Structure ___________________________________ Transparency 37Displacement-Step Diagram _________________________________ Transparency 38

Terminal Connection DiagramTerminal Connection Diagram ________________________________ Transparency 39Checklist for the Terminal Connection Diagram__________________ Transparency 40

Special Features with the Connection of Solenoid CoilsProtective Circuits for Inductive Loads_________________________ Transparency 41

Programmable Logic ControllersAlterable Controls__________________________________________ Transparency 42


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1


Elements of a Control Chain

The principle of the control chain is used for the preparation of the circuit diagram.Every element of a control chain has a certain task to perform in the processing andfurther transmission of signals.

This structuring of a system into functional blocks has proven itself in the followingtasks: Arrangement of the elements in the circuit diagram Definition of the nominal sizes, nominal current and nominal voltage of

components Set-up and commissioning of the controller Identification of the components for maintenance work

Electric motorsSolenoidsLinear motors

Power contactorsPower transistorsPower thyristors

SwitchesPush button

actuatorsLimit switchesProgrammoduleSensors

Electrics/Electronics

SwitchesPush button actuatorsLimit switchesProgram moduleSensorsIndicators/generators

ContactorsRelaysElectronic modules

PneumaticsHydraulics

Directionalcontrol valves

Directionalcontrol valvesIsolating valvesPressure valves

Working elements

Control elements

Processingelements

(Control elements)

Input elements

CylindersMotorsComponents


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2


Single-Acting Cylinder

Compressed air is applied to only one side of the single-acting cylinder.

The piston rod side of the cylinder is vented to atmosphere.

Single-acting cylinders can perform work in only in the advance direction of travel.

The piston rod is driven inwards by the force of a built-in spring or by external forces.

Piston

Reset spring

Piston rod

Bearing capEnd cap

Exhaust portSealing ring

Supply port Cylinder barrel


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Double-Acting Cylinder

The double-acting cylinder is actuated in both directions with compressed air.

It can perform work in both directions of movement.

The force transmitted to the piston rod is greater during the advance stroke thanduring the return stroke.

End cap

Piston Piston rod

Bearing cap

Scraper ring

Cylinder barrel


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4


Non-return, Flow Control and Pressure Control Valves

Non-return valves block the flow in one direction and release it in the oppositedirection. A distinction is made between: Non-return valves Shuttle valves (OR) Dual pressure valves (AND) One-way flow control valves Quick exhaust valves

Pressure control valves influence the pressure or are controlled through the size of the pressure. A distinction is made between: Pressure regulating valves Pressure relief valves Pressure sequence valves

Sloping arrow the valve is adjustable

Non-return valves

Flow control valve

Pressure control valve

Non-return valve (check valve)

Flow control valve (throttle valve), adjustable

Non-return valve, spring-loaded

Shuttle valve (OR function)

Quick exhaust valve

One-way flow control valve

Adjustable pressure regulating valve without relief port

Adjustable pressure regulating valve with relief port

Pressure sequence valve with external supply line

Pressure-relief valve

Pressure sequence valve-combination

Dual pressure valve (AND function)

12

3

2

2

2

2

1

1

1

1

3

12

2

1


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Pressure Regulating Valve

Pressure regulators have the function of keeping the output pressure mainlyconstant, independent of variations in the input pressure and the air consumption.

If the pressure rises at the outlet, the diaphragm moves against the spring force andthe flow cross-section at the valve seat is reduced or closed.

If the pressure drops at the outlet, the spring presses against the diaphragm and thepassage cross-section at the valve seat is enlarged or opened.

The output pressure is adjustable.

The input pressure must be higher than the output pressure.

P1 P2 P1 P2

1

3

2


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6


One-Way Flow Control Valve

The check element blocks the flow of air in one direction, so that it flows across anadjustable throttle in this direction.

The air flow from the opposite direction lifts the seal of the check element from theseat. The compressed air can flow almost unrestricted in this direction.

The valve should be installed as close as possible to the cylinder.

4

5

2

1Y1 1Y2

31

1A

1V2 1V3

1V1


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Quick Exhaust Valve

Quick exhaust valves are used to achieve the maximum advance and retract speedof pneumatic cylinders.

To increase the effectiveness of the valve, it should be mounted directly on thecylinder or in the immediate vicinity of the supply or exhaust ports of the cylinder.

2

3

2

1Y1

1 3

1A

1

1V2

1V1 1V1

2

3

1Y2

13

1A

1

1V2

4

5

2

2

1

3

2

1

3


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Conversion of Electrical Signals into Pneumatic Signals

If control systems are using compressed air and electricity as working mediums,converter systems must be used.

Solenoid valves convert electrical signals into pneumatic signals.

Solenoid valves consist of: A pneumatic valve A coil which switches the valve

2

1 3

unactuated actuated

33

11

22


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Conversion of Pneumatic Signals into Electrical Signals

The PE converter is actuated with compressed air. When the pressure reaches apreset value, an electric signal is generated.

The pressure of a pneumatic signal works against an adjustable spring.

If the pressure working against the diaphragm overcomes the spring force, a stemactuates an electrical switch contact.

The electrical switching element can be normally closed, normally open orchangeover contact.

14

1414

unactuatedactuated


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Switching Symbols for Valves

Pneumatic components are normally shown in the deenergized condition in circuitdiagrams.

Valve switching positions are represented by a square.

The number of squares corresponds to the number of switching positions.

Functions and modes of operation are drawn inside the square: Lines indicate the flow paths. Arrows indicate the flow direction. Closed ports are represented by two lines drawn at right angles to one another.

The connecting lines are drawn outside on the square.

The valve switching position is shown by a square.

The number of squares corresponds to the number of switching positions.

Lines indicate the flow paths, arrows indicate the direction of flow.

Closed ports are shown by two lines drawn at right angles to one another.

The connecting lines for supply and exhaust air are drawn outside the square.


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11


Directional Control Valves: Ports and Switching Positions

Information about the type of valve can be established from the following features: Number of ports Number of switching positions Port numbering

The following applies to the numbering of the ports: Air supply port 1 Exhaust ports 3, 5 Working or outlet ports 2, 4

2/2-way valve, normally open position

4/2-way valve flow from 1 2 and from 4 3

5/2-way valve flow from 1 2 and from 4 5

5/3-way valve, mid-position closed

3/2-way valve, normally closed position

3/2-way valve, normally open position

Number of switching positionsNumber of ports

4

4

4

2

2

2

2

2

2

3

3

3

3

3

1

1

1

1

1

1

5

5


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13


2/2-Way Solenoid Valve without Pilot Control

Normally-closed position, spring return

Solenoid coil deenergized Port 1 is blocked. Port 2 is blocked. Exhausting is not possible.

Solenoid coil energized The armature is raised. Compressed air flows from port 1 to port 2.

2

1

1 12 2


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Solenoid Valves with Pilot Control

Solenoid valves with pilot control consist of: An electromagnetically-actuated pilot control valve. A pneumatically-actuated main valve.

In comparison with solenoid valves without a pilot control, solenoid valves with apilot control are distinguished by: Lower force required to actuate the armature. Smaller dimensions of the coil head. Lower power consumption. Less heat generated.

An electrical signal isapplied to the solenoidcoil

The solenoid coilactuates the pilotcontrol valve

The pilot controlactuates the valve


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3/2-Way Single Solenoid Valve with Pilot Control

Normally-closed position, spring return, manual override

Solenoid coil deenergized Port 1 is blocked. Port 2 is vented to port 3. The pilot control channel is blocked by the armature seal on the valve side. The space above the valve piston is vented through the armature guide tube.

Solenoid coil energized The armature is lifted and the armature seal on the coil side blocks the vent hole

in the armature guide tube, while the armature seal on the valve side opens thepilot control channel.

Compressed air from port 1 flows through the pilot control channel and actuatesthe valve piston.

Port 3 is blocked. Compressed air flows from port 1 to port 2.

2

1 3

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5/2-Way Single Solenoid Valve with Pilot Control

Spring returned, manual override

Solenoid coil deenergized Compressed air flows from port 1 to 2. Port 4 is vented to 5. Port 3 is blocked. The pilot control channel is blocked. The space above the valve piston is vented through the armature guide tube.

Solenoid coil energized The armature is lifted and the armature seal on the coil side blocks the vent in

the armature guide tube, while the armature seal on the valve side opens thepilot control channel.

Compressed air from port 1 flows through the pilot control channel and actuatesthe valve piston.

Port 5 is blocked. Compressed air flows from port 1 to port 4. Port 2 is vented to port 3.

4

4

2

2

1

1

14

14

3

3

5

5

84

84

3

3

2

2

1

1

4

4

5

5

84

84

14

14


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5/2-Way Double Solenoid Valve with Pilot Control

Manual override

Solenoid coil Y1 energized, solenoid coil Y2 deenergized The valve switches over. Port 3 is blocked. Compressed air flows from Port 1 to Port 2. Port 4 is vented to Port 5.

Both solenoid coils deenergized The valve retains its previous switching position.

Solenoid coil Y2 energized, solenoid coil Y1 deenergized The valve switches over. Port 5 is blocked. Compressed air flows from port 1 to port 4. Port 2 is vented to port 3.

4

4

2

2

1

1

14

14

12

12

3

3

5

5

84

84

82

82

3214584 82

14 12

3214584 82

14 12


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5/3-Way Solenoid Valve

The three switching positions of an electrically-actuated pilot-controlled5/3-way valve:

1. In the normal position, the solenoid coils are deenergized and the piston iscentered in its mid-position by the two springs. Ports 2 and 3 as well as 4 and 5are connected. Port 1 is blocked.

2. If current is applied to the lefthand solenoid coil, the piston moves to the right.Ports 1 and 4 as well as 2 and 3 are connected with each other.

3. If current flows through the righthand solenoid coil, the piston moves to the left.In this position, Ports 1 and 2 as well as 4 and 5 are connected.

Each of the two actuated switching positions is held as long as current flows throughthe corresponding solenoid coil. If the flow of current is interrupted, the pistonswitches back to the mid-position.

4

4

2

2

5

5

3

3

1

1

12

12

14

14

84

84

82

82

4 2

5 31

1214

84 82

3

3

3

2

2

2

1

1

1

4

4

4

5

5

5

84

84

84

82

82

82

14

14

14

12

12

12


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Power Supply Units

It is necessary to distinguish between an alternating current and a direct currentpower supply.

Is supplied from the mains 3-phase or single-phase form Sinusoidal-shaped voltage of fixed frequency Relatively constant amplitude Voltage change through transformers

Is supplied by power supply devices

Modules of direct current power supply devices Mains transformer Rectifier Stabilization

Batteries and rechargeable batteries Used for buffering in case of mains failure. Used in portable devices.

+

Transformer StabilizerRectifier

Power supply unit

Alternating current Direct current Battery

Alternating current

Direct current


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Switching Contacts and Types of Actuation

The following switch contact designs are used as input and processing elements: Normally-open contact Normally-closed contact Changeover contact

Types of actuation for switching elements are: Manual Mechanical Relay Magnet field

Normally-opencontacts

Changeoverswitch

Mechanically connectedcontacts

Rotary switch withnormally open contactsmanually actuatedby turning

Push-button withnormally open contactsmanually actuatedby pushing

Limit switch with normally openor normally closed contacts,mechanically actuated

Normally-closedcontacts


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Switching Symbols for Solenoid Coils and Relays

In electropneumatics, the solenoid coil is the element that switches the valves.

Identifying letters in electrical circuit diagrams: Y (Y1, Y2, ...)

A relay switches 1, 2 or more contacts. The relay can also be a time or temperature-controlled element.

Identifying letters in electrical circuit diagrams: K (K1, K2, ...)

Y1

K1

Electro-magneticallyactuated on both sides

Electro-magneticallyactuated,with pilot control

Contactor or relay with3 normally open contactsand 1 normally closed contact

Electro-magneticallyactuated on one side,with spring return

Representation inelectrical circuitdiagrams


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The Relay

In practice, the construction of a relay can be very different, but the function isnevertheless the same in principle: When a voltage is applied to the relay coil through contacts A1 and A2, an

electric current flows through the windings. A magnetic field is built up and pullsthe armature against the core of the coil.

Switch contact 1 is connected with switch contact 4. After removing the voltage, the armature is brought back into its initial position

by a spring. Switching contact 1 is connected with switching contact 2.

A relay can have multiple switching contacts which can be actuated simultaneously.

There are the following types, for example: Polarised relay Current impulse relay Time relay Thermal relay

124A1 A2

A1

A2

221412 24

11 21

Coil core

Insulation

Contact

Return springRelay coil

Armature


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Magnetic Proximity Switches (Reed Switches)

Reed switches are actuated through a magnetic field. In industrial applications, mostreed switches are used with LED displays.

The illustration shows a three-wire reed switch. It has three connections: One connection for the positive power supply One connection for the negative power supply One signal or switch output

The reed switch is attached directly to the body of a cylinder. It is actuated by amagnetic ring on the cylinder piston.

When the magnetic ring moves past the reed switch, the switching contacts areclosed as a result of the magnetic field and thus provide an output signal.

Identifying letters in electrical circuit diagrams: B (B1, B2, ...)

BN

BK

BU

+24V

0V


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Electrical Output Devices

Supply acoustic signals: For example, horns, sirens Identifying letters in electrical circuit diagrams: H (H1, H2, ...)

Supply optical signals: For example, lamps, LEDs Identifying letters in electrical circuit diagrams: H (H1, H2, ...)

Do work: For example, electric motors Identifying letters in electrical circuit diagrams: M (M1, M2, ...)

M

gna ng dev ce

Motors

Audible indicator:

Illuminatingindicators:

Horn

DC motor

Lamp Light emitting diode (LED)

Siren Bell


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The AND Logic Function

The AND logic function consists of at least two switching elements connected inseries: The AND logic function can have two or more inputs. A combination of switches

and sensors may be involved. The function is represented through a logic symbol with two inputs and one

output. Both input signals must be present to switch the output.

&

+24V

0V

S2

H1

S1

1

Output(lamp H1)Input 2

(S2)

Input 1(S1)


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The OR Logic Function

The OR logic function consists of at least two switching elements connected inparallel: The OR logic function can have two or more inputs. A combination of switches

and sensors may be involved. The function is represented through a logic symbol with two inputs and one

output. Only one input signal needs to be present to switch the output.

1

+24V

0V

H1

S1 S2

1 2

Output(lamp H1)Input 2

(S2)

Input 1(S1)


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Control Chain

The structure of the control chain supports: The allocation of components with comparable functions to a group of elements. The avoidance of lines crossing each other in pneumatic and electrical circuit

diagrams. The preparation of clearly structured and uniformly designed circuit diagrams.

The principle of the control chain should be understood as being only a guideline.The signal flow of the control system defines the structure of the control chain: In the pneumatic circuit diagram, the signal flow is represented from bottom to

top. In the electrical circuit diagram, the signal flow is represented from top to

bottom.

+24V

Signalinput

S i g n a

l f l o w

S i g n a

l f l o w

Signalprocessing

Signaloutput

0V

S1

S2

K1K1

1Y1

2

1 2

4

5

2

1Y1

31

1A

1V1


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Direct Actuation of a Single-Acting Cylinder

After actuating S1, current flows through the coil 1Y1, which switches the valve 1.1.

Compressed air flows from port 1 to port 2, and the piston rod advances.

If S1 is no longer actuated, there is no current through coil 1Y1. Valve 1.1 switchesback into the initial position.

The cylinder is vented through port 3 of valve 1.1, and the piston rod retracts.

1Y1

2

1Y1

1A

1V1

+24V

0V

S1

1

1 3


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Indirect Actuation of a Double-Acting Cylinder

The use of indirect actuation depends upon: The force which is required for the actuation of the positioner The complexity of the circuit The switching power of the contacts Whether or not the system is remote controlled

K1 1Y1

1A+24V

0V

S1 K1

1 2

4

5

2

1Y1

3

13

A1

A2

13

14 14

1

1V1


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Electrical Memory Circuit Dominant Set

A relay can be held in the switched condition if a holding current path is switched inparallel to the ON pushbutton through an internal normally-open contact in therelay.

An OFF pushbutton must be built into the memory circuit. The installed position of the OFF pushbutton determines the function of the memory circuit.

A memory circuit in which a pushbutton (S2, normally-closed) is connected in serieswith a relay holding contact (normally-open) is a dominating set memory circuit.

In this dominating set memory circuit, the pushbutton S1 dominates the pushbuttonS2.

If S1 and S2 are pressed simultaneously, current flows through the relay coil K1.

+24V

0V

S1

S2

K1 K1

2

3

1 2 3

13 23

14 24

K1 H1


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Electropneumatic Memory Circuit with Double Solenoid Valve

Double solenoid valves are also called bistable valves or memory valves: The valve illustrated is actuated by two solenoid coils. The valve retains the switched position brought about through energising one of

the coils, even when the signal to switch the valve is cancelled. The switched position is reversed only when a signal is applied to the opposite

coil or a manual override is operated. To reverse the switched position, a signal only needs to be applied to one coil.

1A 1S2

4

5

2

1Y1 1Y2

31

1V1

1Y1 1Y2

+24V

0V

S1

1 32 4

1S2 K1 K2

K1 K2

3 4


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34


Stroke-Dependent Control

Limit switches with roller lever actuation are frequently used to check the position of pneumatic actuators in simple circuits.

The use of limit sensors in a control depends upon the required accuracy of thesensor.

Decisive factors are: The reliability The safety The complexity of the circuit

1A 1S21S1

4

5

2

1Y1 1Y2

31

1V1

1Y1 1Y2

+24V

0V

S1

1S1

1 32 4

1S2 K1 K2

K1 K2

3 4


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35


Pressure-Dependent Control

A pneumatic-electric signal converter measures the air pressure in the supply line of cylinder 1A and compares it with a preset value.

As soon as this value is reached, the signal converter generates an electrical signal.

1A

4

5

2

p

1Y1

1B1

1Y2

31

1V1

1Y1 1Y2

+24V

0V

S1

1 6 7

K1 K2

K3

K1

5 6 6

1B2

1B2 1B1

p

2 43 5

K2 K3


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The Electropneumatic Circuit Diagram

The pneumatic and electrical parts of an electropneumatic circuit diagram areprepared separately, but their contents are closely related.

In the pneumatic part, signal flow is presented from bottom to top.

In the electrical part, signal flow is presented from top to bottom.

In the electrical circuit diagram, the current paths are numbered consecutively fromleft to right.

The common circuit diagram elements form the interfaces between the pneumaticand the electrical circuits. In this case, they are the coils 1Y1 and 2Y1, as well as thelimit sensors 1B1, 1B2, 2S1 and 2S2.

44

55

22

2Y11Y1

33 11

2A1A

2V11V1

2S21B21B1

2S1

1Y1 2Y1

+24V

0V

Start 2S1

K6 K5

1B1 1B2

1 3 5 6 8 10 12 13117 92 4

2S2K3 K4 K5 K3 K4K2

K1

K3 K4 K5

K1 K2 K3 K4 K5 K6

5 7 67

12

89

13

1011

13 5


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Circuit Diagram Structure

The electropneumatic circuit diagram consists of two parts: Pneumatic Electrical

The arrangement of the components follows the signal flow accordingly frombottom to top.

Cylinders and valves are drawn horizontally. The outward travel motion of cylinders should be from left to right.

The arrangement of the components follows the signal flow accordingly from topto bottom.

The electrical circuit diagram can be subdivided into a control part and a powerpart.

1A

1V2

0Z

1S2

4

5

2

1Y1 1Y2

31

1V1

1Y1 1Y2

+24V

Contro l sec tion Power sec tion

0V

S1

K2

1 32 4

1S2 K1 K2

K1 K2

3 4

Pneumatic

Electrical


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Displacement-Step Diagram

In a displacement-step diagram, the motion sequences of an actuator in a controlsystem are presented graphically: Movements of the cylinder within a step are represented by a line moving

diagonally upwards (advancing) or downwards (retracting). Horizontal lines represent the position of the cylinder in the advanced or

retracted end position. If the movements of several actuators are to be represented, they are arranged

under each other for every individual step. This arrangement clarifies the relationship between the movements of the

individual actuators in every step.

1

0

1

0

1

Step

2 3 4 5=1

1A

2A


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Terminal Connection Diagram

The terminal connection diagram shows the physical implementation of the currentcircuit.

The identifications used in the circuit diagram are used in the terminal connectiondiagram.

The terminal points and the cables are numbered. This facilitates the setting-up of the controller as well as troubleshooting and maintenance.

X1-1 X1-2

3 1

11 11

21

4 2

14 14

24

X1-3 X1-4

X1-9 X1-12 X1-14

X1

X1 14

15

14

20

13

19

12

18

11

17

10

16

9

8

7

6

54

3

2

1

1Y1

K1 114

3

+24V

K2 21

X1 110V

K1 A2

K2 A2

X1 17

1B1 X1 1+

1B1

1S2

K1

K2

A1

24

1B1

1S2

X1

X1

5

8

1Y1

X1 2S1

X1 31

S1

K2 112

9

12X1

4

5

2

1Y1

31

1A

1V1

1S21B1

1Y1

+24V

0V

S1 1S21B1

1 3 4 52

K1 K2

K2

K1 K2

3 45

X1-11

X1-16

X1-10

A1 A1

A2 A2

X1-5 X1-8X1-6 X1-7

X1- 13 X1-15

X1-17

C o n n e c t i o n

c o

d e

C o m p o n e n t

c o

d e

C o m p o n e n

t

c o d e

C o n n e c t i o n

c o

d e

T e r m

i n a

l n o

. X 1

J u m p e r

T a r g e

t

T a r g e

t

Machine Control cab inet


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Checklist for the Terminal Connection Diagram

In the preparation of a terminal connection diagram, the structure of the controlshould be checked once again: Is every current path connected to the positive +24V bus bar through a terminal? Is every current path connected to the negative 0 V bus bar through a terminal? Are all external components, such as switches, sensors and valve coils connected

with one terminal per connection to the current circuit? Are all connections to the +24 V and 0 V shown in the terminal connection

diagram? Are all external components included in the terminal connection diagram

provided with their connection identifications? Check all current paths systematically and complete the terminal connection

diagram. Note that not all connections such as the relay contacts, for example must be

included in the terminal connection diagram.

Enter all external components with thedesignation of the connection in theterminal connection diagram.

Systematically check all current pathsand complete the wiring diagram.

Not all of the connections have to beentered in the wiring diagram(e.g. relay connections are exempt).

Note:

Each current path must be connectedto the positive +24 V rail via a terminal.

Each current path must be connectedto the negative 0 V rail via a terminal.

External components, such as switches,sensors and solenoids are eachconnected via one terminal per unit.

Identify the connection point for +24 Vand 0 V in the wiring diagram.


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Protective Circuits for Inductive Loads

If the current flowing to an inductive load, for example, a solenoid coil, isinterrupted, the magnetic field collapses.

A high induction voltage can be generated which can have the following effects: Damage to the coil insulation Burning of contacts

This can be avoided through protective circuits using diodes.

I1 I = 01

I = IM 1 IMI = 0D I = ID M

+24V +24V0V 0V


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Alterable Controls

Relay-controlled systems are hard wired. The relay control can be replaced in wholeor in part by a programmable controller.

The structure of a system that is controlled via a programmable logic controller (PLC)is similar to that of a relay-controlled system. Both systems can be subdivided asfollows: Signal input Signal processing Signal output

The signal processing part is the part that can be hard wired or freely programmable.

Switch

Inputs

Signalinput

Signaloutput

Signal processing

Relays Contacts

Outputs

Program:

WHEN

THENOTHERWISE

WHEN

THENOTHERWISE

E0.1E0.2

A0.1A0.1

E0.3E0.4

A0.2A0.2

RESET

RESET

AND

SET

AND

SET

Processor

S1

S2

S3

S4

K1

K2

K3

K4

H1

H2

K1 K2

K3 K4

+ +

S1

S2

S3

S4

E1

E2

E3

E4

H1

H2

A1

A2

+ +

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