Introduction to Industrial Automation

 

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  Introduction to Industrial Automation

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Β

Out

Start

S

1

S

2

In

Α

S

1

S

2

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 5.9. A simple robotic mechanism consists of two cylinders C

1

 and C

2

 transferring objects on 

a horizontal surface from position P

1

 to position P

3

 through position P

2

 according to the 

position-step diagram. The proximity switch PS detects the presence of an object in position 

P

1

 and then the transportation of the object starts. The robotic mechanism starts to oper-

ate through a two-position rotary switch RS

0-1

 and transfers objects continuously as long as 

they are placed in position P

1

. The introduction of objects occurs in position P

1

 and they 

are exported in position P

3

 manually. If the switch RS

0-1

 opens in the middle of an object 

transfer phase, the last object has to be integrated and then to be stopped. After selecting the 

required additional electro-pneumatic equipment (cylinders kind, directional valves, sen-

sors, etc.), design the electric automation circuit by applying the state diagram method in 

order for the position-step diagram to be realized iteratively.

C

1

C

2

P

1

P

2

P

2

P

3

 

P

1

C

1

C

2

PS

P

2

P

3

1 2 3 4 5

 5.10. Two double-acting cylinders C

1

 and C

2

 are arranged opposite each other as shown in part 

(a) of the figure, and it is desired to perform a collaborative movement according to the 

position-step diagram shown in part (b) and to transfer an object between the two piston 

rods. At the rest state, the object is in the terminal left position. By pressing a button (move) 

instantly, the object comes to the terminal right position and remains there. By pressing 

the button move again, the object returns to the terminal left position, and so on. The 

pneumatic circuit is shown in part (c) of the figure, where S

1

 and S

2

 are the solenoids of the 

directional valves. The proximity sensors a

1

, a

2

, b

1

, and b

2

 detect the terminal positions of 

the two cylinders. Design the required electric automation circuit.

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Elements of Electro-Pneumatic Components 

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189

a

1

a

2

b

1

b

2

(a)

C

1

C

2

S

1

S

2

C

1

C

2

(c)

In

Out

In

Out

a

1

a

2

b

1

b

2

(b)

C

1

C

2

 5.11. A painting station includes two conveyor belts, the cylinder A for pushing objects on the 

painting table, the painting head B which operates with pressurized air, and the cylinder 

C for removing the painted objects. The conveyor belts operate continuously and transfer 

objects to and from the painting station. Therefore, they don’t affect the automation logic. 

If an object is detected along the dashed line S from a corresponding proximity switch, 

the automation system must realize the position-step diagram shown in the figure. After 

selecting the required additional electro-pneumatic equipment (cylinders kind, directional 

valves, sensors, etc.), design the electric automation circuit.

Α

Β

C

Α

B

S

C

Pressurized

air flow

Paint

spray gun

 5.12. The figure shows an object stamping station which is switched in/out using a standby opera-

tion through two corresponding buttons. The standby operation state is indicated in the 

control panel and means that the station can automatically stamp an object if it is placed in 

position 1. In particular, if the station is in standby mode and an object is placed in position 

1 (signal S

1

), then the object is transferred to position 2 (signal S

2

) through the operation of 

the conveyor belt M. Then, the extraction of the cylinder is energized, the stamping is real-

ized (signal S

5

), and subsequently the retraction of the cylinder begins. Just as the piston rod 

returns (signal S

4

), the object is transferred to position 3 (signal S

3

) and remains there until 

a technician removes it. Suppose that only one object exists at the station each time. After 

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