Introduction to Industrial Automation

Figure 5.26  An object’s classification arrangement and pneumatic circuit with three cylinders.

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Elements of Electro-Pneumatic Components 

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  3. When an object passes from the corresponding sensor in one of the three final conveyor 

belts, this sensor signal is utilized for energizing the retraction of the C cylinder, in order to 

allow the feeding of new objects, and thus a new cycle starts again.

For the pneumatic circuit, four-way, two-position valves have been selected, each with two 

operational solenoids or coils, one for each of the switching states. The most common type of valve 

is with one coil and return spring; however, we are selecting two coils in order to demonstrate how 

easily an industrial automation circuit becomes quite complex. In Figure 5.27, the automation 

circuit is presented, which is set into operation by classical START-STOP push buttons.

Problems

  5.1. Design an arrangement for the separation of similar objects in two parallel transportation 

lines as shown in the figure. The objects’ separation is based on their simple alternative place-

ment through the moving part of the conveyor. In particular, select and design:

 

a.  The required electro-pneumatic equipment (cylinder, directional valve, sensors, etc.)

 

b.  The required pneumatic circuit

 

c.  The required electric automation circuit

Note:

 The frequency of objects’ arrival is such that one object can arrive in the separation point 

before the previous one reaches one of the two parallel conveyors. This means that in such a case, 

the motor M must stop as long as needed.

N

R

START

STOP

Coil A

2

a

b

a

 

d

0

d

0

d

1

d

1

d

2

Coil A

1

d

2

a

b

d

3

Coil B

2

d

3

d

0

Coil B

1

b

d

4

d

4

Coil C

1

a

d

5

d

5

b

Coil C

2

c

d

6

d

6

d

e

1

2

1'

2'