165000503 electro-pneumatic

introduction to electropneumatic

1. Introduction to Electro Pneumatics
Contents :-
1.What is Electro-Pneumatics : a definition
2.Electro-Pneumatic Signal Control system
3.Electro-Pneumatics Basic control components
4.Application Example

2. Introduction to Electro Pneumatics
WikiAnswers.com wrote,
Pneumaticsisamethodtotransferenergyfromonepointtoanother
usingactuatorswhicharedrivenbyfluidsunderpressure.
Pneumaticsrestrictsitselftogaseousfluidswhilehydraulicsuses
liquidstotransfertheenergy.
Thetransferringofenergyinpneumaticssuchaspumpingairintoa
pneumaticcylindermustbecontrolled.
Youcancontrolthepressurebymanuallyopeningavalve,
automaticallybydetectingitspressure,orbysendinganelectrical
signal. Thecontrolofpneumaticcomponentsbyelectrical
impulsesisknownaselectro-pneumatics.
1.1 Definition of Electro-Pneumatics

3. Introduction to Electro Pneumatics
Bothpneumatic&electro-pneumaticcontrollershave
apneumaticpowersection.Inanelectro-pneumatics
control,thesignalcontrolsectionismadeupofa
electricalcomponents,suchaselectricalinput
buttons,proximityswitches,relays,ora
programmablelogiccontroller(PLC).
Source : Electropneumatics –A basic, G Prede, D Scholz
Question 1 :
What is your definition for Electro-Pneumatics?
_____________________________________
_____________________________________
[3 marks]
1.2 Other Definition of Electro-Pneumatics

4. Introduction to Electro Pneumatics
Definition :
Electro-pneumatic termisdefinedfromthewordsof
electrowhichmeanselectricalandpneumaticwhich
meansairpressure.
Theelectro-pneumatics equipmentsandsystemis
anintegrationofelectricalandmechanical
componentswithcompressedairsource.
Electropneumaticisapneumaticcontrolsystem
whereairpressureanddirectionofvalveare
controlledbyanelectricalcurrent.
1.3 Our Definition of Electro-Pneumatics

5. Introduction to Electro Pneumatics
Electro pneumatic is integration of two control circuit
1.Pneumatic Circuit
2.Electrical Circuit
1.4 Electro-Pneumatics’ circuit

6. Introduction to Electro Pneumatics
(a)
Pneumatic circuit

7. Introduction to Electro Pneumatics
(b)
Electrical circuit

8. Introduction to Electro Pneumatics
1.5 Combination of Pneumatic circuit and Electrical circuit

9. Introduction to Electro Pneumatics
2.1 A Background –Basic Control system
Command
Execution
Signal
Output
Signal
Processing
Signal
Input
Powercomponent
FinalControlelement
Processingelement
Inputelement

10. Introduction to Electro Pneumatics
2.2 Signal flow and component of an Electro-
Pneumatic control system
Source :
Electropneumatics Basic Level
by G Prede, D Scholz

11. Introduction to Electro Pneumatics
2.3 Pneumatic power section
Directionalcontrolvalvesformtheinterface
betweenthesignalcontrolsection(electrical)and
thepneumaticpowersectioninanElectro-
pneumaticsystem.

12. Introduction to Electro Pneumatics
2.4 Electrical signal control section

13. Introduction to Electro Pneumatics
1.Lesser wear-off parts. Lesser installation jobs.
i.e., Electrical control valve, Electrical switches
2.Replace tube in pneumatic system to electrical
wire in electro-pneumatic
3.Less parts are used Reduce working space.
4.Sensor and Controller (such as PLC) can be included in the system
2.5 Advantages of using Electro-Pneumatics
Push Button
E-260
Electrical signal
input
(switch panel)

14. Introduction to Electro Pneumatics
Question :
List-up (at least) 2 advantages and 2 disadvantages
of Pneumatic system.
2.3 Assignment 1

15. Introduction to Electro Pneumatics
Question :
By using suitable pneumatic circuit, show
pneumatic component classification.
Source: 2009 Sem2 DNT241 Final exam question
This year final exam Question(?)
List-up 4 component classifications in Electro-
pneumatic control system and give 2 example for
each component.
3.0 Introduction to Electro-pneumatic control
component

16. Introduction to Electro Pneumatics
Switches :
There are 3 types of electrical switches used in
design Electro-pneumatic circuit.
1. Normally Open switch
2. Normally Close switch
3. Multiple contact switches
Sensors :
1. Mechanical Position sensor (Limit switch)
2. Proximity sensor
3. Reed switch
3.1 Input Element component

17. Introduction to Electro Pneumatics
3.2 Switching Contact and type of actuation

18. Introduction to Electro Pneumatics
3.3.1 Normally Open (N.O) and Normally Close (N.C)
In pneumatic circuit :
For example : 3/2-way Push button (valve)
Normally Open Normally Close
In electrical circuit :
For example : Push button switch
Normally Open Normally Close

19. Introduction to Electro Pneumatics
3.3.2 Normally Open (N.O) and Normally Close (N.C)

20. Introduction to Electro Pneumatics
3.4 Mechanical Position sensor
(Pneumatic)
3/2-way N.C valve with roller (Limit switch)
(Electro-Pneumatic)
Mechanical Position sensor (Limit switch)

21. Introduction to Electro Pneumatics
Proximity sensor contain a transistor which
conducts and switches (trigger ON) when something
comes near to the sensors.

Some of the proximity sensor only work with steel
material components －Inductive proximity sensor
3.5 Proximity sensor

22. Introduction to Electro Pneumatics
Question :
1.Name the switch type used for START and STOP button.
2.What is the different between A1 and A2 in Electrical circuit?
3.5.1 Proximity sensor –Symbol and Sample Circuit
Proximity Sensor

23. Introduction to Electro Pneumatics
Reed switch is one of the sensor which is operated
by the magnetic field.
Usually fit directly onto cylinder with clips.
The piston of the cylinder has a magnet built into it
and when the piston comes close to the reed
switch, the contact is close (ON).
3.6 Reed switch

24. Introduction to Electro Pneumatics
Relay is an electrically actuated switch, contains a coil
and a contactor switch or multiples contactors.
When power is applied to relay coil, the core
magnetizes, drawing the contact assembly in.
This will change the state of all the contacts in the relay
(i.e., N.O contact becomes closed or N.C contact
becomes open).
Relay uses small amount of power to control switching
(advantage). The voltage applied to the coil doesn’t
have to be the same as that in control circuit.
Relay is used to allow low voltage control systems to
switch large current/ high voltage
(function / advantage)
3.7 Processing element -Relay

25. Introduction to Electro Pneumatics
3.7.1 Sample circuit
Coil
When Toggle switch 1S3 is pressed, power is applied to
Relay (K1) coil which result to the all contactors in relay
change their state (open close or close open).
Solenoid valve 1Y1 activate to ON
E-140
Contactor

26. Introduction to Electro Pneumatics
3.7.2 N.O and N.C wire connection
Normally Close (N.C)
Example : Pin 21 22
Normally Open (N.O)
Example : Pin 41 44

27. Introduction to Electro Pneumatics
3.7.3 Animation (Relay OFF)
Source : UniKL Electro- Pneumatic Lecture Note, 2008

28. Introduction to Electro Pneumatics
3.7.4 Animation (Relay ON)

29. Introduction to Electro Pneumatics
3.7.5 More about Relays
Relay has a few functions as a safety device:
1.The high voltage output (i.e. 240V) can be switched ON
through a contactor using relay with low voltage (i.e.
24V) supplied to a coil.
2.The high current output can be switched ON through a
contactor using relay with low current supplied to a coil.
3.Functioned as Safety control circuit for emergency
power cut- off (EMERGENCY START and STOP button)
to the whole circuit.
Use in automation process  Switching more than one
outputs simultaneously using relay with a coil and multiple
contactors.
To control ON and OFF of various outputs sequences using
several Relay.

30. Introduction to Electro Pneumatics
Solenoid valve is an electro-mechanical device that
built-in with a coil (solenoid) and a pneumatic
Directional control valve.
Solenoid actuated Directional control valve (DCV)
convert electrical signals to pneumatic signals.
They are used to start, to stop and/or to change
the direction of air flow.
There 3 main types of solenoid valve.
1.3/2-way Solenoid valve with spring return
2.5/2-way Solenoid valve with spring return
3.5/2-way Double solenoid valve
3.8 Final control element –Solenoid DCV

31. Introduction to Electro Pneumatics
5/2-way Solenoid valve with
spring return
3/2-way Solenoid valve with
spring return
3.8.1 Solenoid DCV
5/2-way Double solenoid valve

32. Introduction to Electro Pneumatics
3.8.2 Symbol and sample circuit
(Pneumatic)
Pilot actuated 5/2-way Directional control valve
(Electro-Pneumatic) Solenoidactuated 5/2-way Directional control valve
Pneumatic Power Component ---cylinder
Final Control element ---Solenoid valve

33. Introduction to Electro Pneumatics
3.8.3 Symbol in Electrical circuit
When Pushbutton switch (SW1) is pressed, power is
applied to Solenoid S1 which then change the electrical
signal to pneumatic signal and allow air flow to cylinder
A (single acting with spring return) for rod to extend.
Solenoid

34. Introduction to Electro Pneumatics
3.8.4 Sample Circuit connection
Red cable is connection
from 24V line.
Blue cable is connection to
GND (0 V).

35. Introduction to Electro Pneumatics
3.8.5 Solenoid -Structure
Source : UTeM Chapter 4 ---ElectroPneumatic

36. Introduction to Electro Pneumatics
4.0 Supply / Power component
In Electro-Pneumatic system, the supply or power
source component is divided into two, based on the
system component.
1. Pneumatic －Compressor
2. Electrical －AC / DC power supply
Symbol for 24V DC
IEC Standard JIC Standard

37. Introduction to Electro Pneumatics
4.1 Self-Latching concept
Self-latching will enable the automation system to run in automatic
mode after the START button is pressed and the system repeats until
STOP button is pressed.
The advantage of having self-latching in the system is that it can be
used as power switching and emergency button.
START
STOP
Self-latching
circuit

38. Introduction to Electro Pneumatics
4.2 Electro-Pneumatic Application
In this section, we will learn some of the actual
application for Electro-pneumatic system.
1. Single-acting cylinder (with spring return)
2. Double-acting cylinder (1 unit)
3. Double-acting cylinder (2 units)
Based on the system / operation given, the students
should capable to :
a) Understand the system’s operation and draw /
sketch Displacement-step diagram
b) Design Pneumatic circuit and Electrical circuit for
the system.

39. Introduction to Electro Pneumatics
4.3 Application 1
Using a sorting device, parts are to be transferred from conveyor
belt. By pressing the pushbutton switch, the piston rod of a single-
acting cylinder pushes the part off the conveyor belt. When the
pushbutton is released, the piston rod returns to the retracted end
position.

40. Introduction to Electro Pneumatics
4.3.1 Pneumatic circuit and Electrical circuit
Question :
Complete the missing part in Electrical circuit.
Pneumatic circuit
Electrical circuit
?

41. Introduction to Electro Pneumatics
4.4 Application 2
Wooden planks are to be pushed along from a gravity feed magazine
to a clamping device. By pressing a pushbutton switch one plank is
pushed by the slide out of the gravity feed magazine. After the slide
has reached the forward end position it is returned to its start
position.

42. Introduction to Electro Pneumatics
4.4.1 Pneumatic circuit
Question :
Please design complete Electrical circuit to control above pneumatic
circuit.

43. Introduction to Electro Pneumatics
4.5 Application 3
Using a transfer station blocks are to be transferred from a magazine to a
processing station.
The blocks are pushed out of the magazine by cylinder A and transferred to
the processing station by cylinder B. The piston rod of cylinder A may only
return when the piston rod of cylinder B has reached the retracted end
position. The magazine is monitored by means of limit switches. If there
are no more blocks in the magazine, it is not possible to start the cycle.
This is indicated by means of push button to act as a sensor. The control is
to be operated in single cycle.
Cylinder A
Cylinder B

44. Introduction to Electro Pneumatics
4.5.1 Displacement-step Diagram
1.The blocks are pushed out of the magazine by cylinder A and
transferred to the processing station by cylinder B.
2.The piston rod of cylinder A may only return when the piston rod of
cylinder B has reached the retracted end position.
3.The magazine is monitored by means of limit switches. If there are no
more blocks in the magazine, it is not possible to start the cycle. This is
indicated by means of push button to act as a sensor, named as
‘Part_detect’ sensor.
4.The control is to be operated in single cycle.
Abbreviation notation : A+ B+ B-A-
Displacement-step Diagram :

45. Introduction to Electro Pneumatics
4.6 Other components in Electro-Pneumatic
1.AND / OR Logic
2.Timer ON / Timer OFF.
3.Pressure Switch.
4.Counter
5.LED
Etc…

46. Introduction to Electro Pneumatics
We should be :
1.Understand what has been called as Electro-
Pneumatics and can simply describe it.
2.Understand the 5 main components in Electro-
pneumatic control system
3.Understand the name and symbol of each
component and how its working in the electrical
circuit (function).
4.Understand on how to design Pneumatic and
Electrical circuit based on the given applications.
5.Can demonstrate the theories learning in class to
practical.
5.0 What has been learned in this session?

47. Introduction to Electro Pneumatics
Application 1
6.0 Answer
Application 2

48. Introduction to Electro Pneumatics
Pneumatic circuit
6.1 Application 3
Electrical circuit

49. Introduction to Electro Pneumatics
Pneumatic circuit
6.2 Include Self-latching circuit
Electrical circuit