Chapter 6continue Introduction to ElectroPneumatic PREPARED BY MOHD

Chapter 6…continue Introduction to Electro-Pneumatic PREPARED BY: MOHD SHAHRIL SHARIFF

Example 6. 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.

Solution Example 6. 1 Pneumatic circuit Electrical circuit

Example 6. 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. Design pneumatic and electrical circuit of electro pneumatic system below

Solution Example 6. 2 Pneumatic circuit Electrical circuit

Example 6. 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. Design complete Pneumatic circuit. Design complete Electrical circuit.

Solution Example 6. 3 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- ADisplacement-step Diagram :

Solution Example 6. 3 (cont. ) (1 st method) Pneumatic circuit Electrical circuit

Solution Example 6. 3 (cont. ) (2 nd method) 1. 2. 3. 4. Identify sequence of movement Divide sequence into groups Identify limit switch status Identify number of conductor line ( = number of group) 5. Identify number of reversing switch (= number of group)

Solution Example 6. 3 (cont. ) (2 nd method) • • • Sequence : Groups: limit switch status : Conductor Line: Reversing Switch: A+, B+, K 1 : A 1 B 1 L 1 : S 1 : B-, AK 2 B 0 A 0 L 2 S 2

Solution Example 6. 3 (cont. ) 2 reversing switch 2 conductor line

Solution Example 6. 3 (cont. ) Start + A 0 A+

Solution Example 6. 3 (cont. ) A 1 B+

Solution Example 6. 3 (cont. ) B 1 B-

Solution Example 6. 3 (cont. ) B 0 A-

Solution Example 6. 3 (cont. ) Electro. Pneumatic Circuit

Include Self-Latching Circuit Pneumatic circuit OFF Dominant ON Dominant Electrical circuit

Other Sequences App. 1 : A+ B+ A- , B-

Other Sequences App. 3 : A+ B+ A- B- Direct In. Direct