Electro-pneumatic xy12

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

Introduction to Electro Pneumatics 1.1 Definition of Electro-Pneumatics WikiAnswers.com wrote, Pneumatics is a method to transfer energy from one point to another using actuators which are driven by fluids under pressure. Pneumatics restricts itself to gaseous fluids while hydraulics uses liquids to transfer the energy. The transferring of energy in pneumatics such as pumping air into a pneumatic cylinder must be controlled. You can control the pressure by manually opening a valve, automatically by detecting its pressure, or by sending an electrical signal. The control of pneumatic components by electrical impulses is known as electro-pneumatics.

Introduction to Electro Pneumatics 1.2 Other Definition of Electro-Pneumatics Both pneumatic & electro-pneumatic controllers have a pneumatic power section. In an electro-pneumatics control, the signal control section is made up of a electrical components, such as electrical input buttons, proximity switches, relays, or a programmable logic controller (PLC). Source : Electropneumatics – A basic, G Prede, D Scholz

Question 1 : What is your definition for Electro-Pneumatics? _____________________________________ _____________________________________ [3 marks]

Introduction to Electro Pneumatics 1.3 Our Definition of Electro-Pneumatics Definition :  Electro-pneumatic term is defined from the words of electro which means electrical and pneumatic which means air pressure.  The electro-pneumatics equipments and system is an integration of electrical and mechanical components with compressed air source.  Electro pneumatic is a pneumatic control system where air pressure and direction of valve are controlled by an electrical current.

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

Introduction to Electro Pneumatics (a) Pneumatic circuit

Introduction to Electro Pneumatics (b) Electrical circuit

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

Introduction to Electro Pneumatics 2.1 A Background – Basic Control system Command Execution

Signal Output

Signal Processing

Signal Input

Power component

Final Control element

Processing element

Input element

Introduction to Electro Pneumatics 2.2 Signal flow and component of an ElectroPneumatic control system

Source : Electropneumatics Basic Level by G Prede, D Scholz

Introduction to Electro Pneumatics 2.3 Pneumatic power section

Directional control valves form the interface between the signal control section (electrical) and the pneumatic power section in an Electropneumatic system.

Introduction to Electro Pneumatics 2.4 Electrical signal control section

Introduction to Electro Pneumatics 2.5 Advantages of using 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 E-260 Electrical signal input (switch ) Push Button

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

Introduction to Electro Pneumatics 3.0 Introduction to Electro-pneumatic control component 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 Electropneumatic control system and give 2 example for each component.

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

Introduction to Electro Pneumatics 3.2 Switching and type of actuation

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

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

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)

Introduction to Electro Pneumatics 3.5 Proximity sensor  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

Introduction to Electro Pneumatics 3.5.1 Proximity sensor – Symbol and Sample Circuit

Proximity Sensor

Question :

1.

Name the switch type used for START and STOP button.

2.

What is the different between A1 and A2 in Electrical circuit?

Introduction to Electro Pneumatics 3.6 Reed switch  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 is close (ON).

Introduction to Electro Pneumatics 3.7 Processing element - Relay  Relay is an electrically actuated switch, contains a coil and a or switch or multiples ors.  When power is applied to relay coil, the core magnetizes, drawing the assembly in.  This will change the state of all the s in the relay (i.e., N.O becomes closed or N.C 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)

Introduction to Electro Pneumatics 3.7.1 Sample circuit

E-140

or

Coil

When Toggle switch 1S3 is pressed, power is applied to Relay (K1) coil which result to the all ors in relay change their state (open  close or close  open). Solenoid valve 1Y1 activate to ON

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

Introduction to Electro Pneumatics 3.7.3 Animation (Relay OFF)

Source : UniKL Electro-Pneumatic Lecture Note, 2008

Introduction to Electro Pneumatics 3.7.4 Animation (Relay ON)

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 or using relay with low voltage (i.e. 24V) supplied to a coil. 2. The high current output can be switched ON through a or 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 ors. To control ON and OFF of various outputs sequences using several Relay.

Introduction to Electro Pneumatics 3.8 Final control element – Solenoid DCV

 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

Introduction to Electro Pneumatics 3.8.1 Solenoid DCV 5/2-way Double solenoid valve

5/2-way Solenoid valve with spring return 3/2-way Solenoid valve with spring return

Introduction to Electro Pneumatics 3.8.2 Symbol and sample circuit (Pneumatic) Pilot actuated 5/2-way Directional control valve (Electro-Pneumatic) Solenoid actuated 5/2-way Directional control valve

Pneumatic Power Component --- cylinder

Final Control element --- Solenoid valve

Introduction to Electro Pneumatics 3.8.3 Symbol in Electrical circuit

Solenoid

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.

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).

Introduction to Electro Pneumatics 3.8.5 Solenoid - Structure

Source : UTeM Chapter 4 --- ElectroPneumatic

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

Introduction to Electro Pneumatics

4.1 Self-Latching concept

Self-latching circuit START STOP

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.

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.

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 singleacting cylinder pushes the part off the conveyor belt. When the pushbutton is released, the piston rod returns to the retracted end position.

Introduction to Electro Pneumatics

4.3.1 Pneumatic circuit and Electrical circuit

?

Pneumatic circuit

Electrical circuit

Question : Complete the missing part in Electrical circuit.

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.

Introduction to Electro Pneumatics

4.4.1 Pneumatic circuit

Question : Please design complete Electrical circuit to control above pneumatic circuit.

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

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-  ADisplacement-step Diagram :

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…

Introduction to Electro Pneumatics 5.0 What has been learned in this session?

We should be :

1. Understand what has been called as ElectroPneumatics and can simply describe it. 2. Understand the 5 main components in Electropneumatic 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.

Introduction to Electro Pneumatics 6.0 Answer Application 1

Application 2

Introduction to Electro Pneumatics 6.1 Application 3 Pneumatic circuit

Electrical circuit

Introduction to Electro Pneumatics 6.2 Include Self-latching circuit Pneumatic circuit

Electrical circuit