Introduction to Industrial Automation

 

◾

  Introduction to Industrial Automation

  5.5. Objects are moving in opposite directions from two conveyor belts, M

1

 and M

2

, toward a 

central point where a cylinder pushes them onto the conveyor belt M

3

. In your opinion, 

define the correct mode of operation and select the kind and placement of the required 

sensors. The most basic issue you will have to determine is the behavior of the system when 

two objects arrive simultaneously in front of cylinder. After assessing all the conditions of 

operation, design the required automation circuit.

M

1

Cylinder

M

3

M

2

  5.6. Non-symmetrical devices are transported on a conveyor belt system where their direction of 

motion and orientation change through a rotating table. The two cylinders C

1

 and C

2

 push 

in and push out devices on the rotating table correspondingly. The conveyor system starts 

to operate through a two-position rotary switch RS

0-1

 and the two conveyor belts M

1

 and 

M

2

 start to operate simultaneously. When a device reaches in front of proximity switch PS

1

, 

then C

1

, M

0

, and C

2

 must perform the movements defined in the position-step diagram of 

the figure. The proximity switch PS

2

 is energized in each half-rotation of the table M

0

. The 

frequency of the device’s arrival is such that a device has been transferred from M

1

 to M

2

 

before another one reaches in front of PS

1

.

    After selecting the required electro-pneumatic equipment such as kind of cylinders, 

directional valves and additive sensors for detecting the motion of piston rods, design the 

electric automation circuit.

M

1

C

1

M

0

M

2

C

2

PS

1

PS

2

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Elements of Electro-Pneumatic Components 

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187

Cylinder C

1

Steps

1

2

3

4

5

6=1

PS

2

M

0

In

In

Out

Out

Cylinder C

2

  5.7. The double-acting cylinder in the figure has a stroke equal to the distance between limit 

switches a and c. With the help of the limit switch b, it is desired an intermediate position of 

the piston rod. Design the pneumatic and automation circuits so that the piston rod follows 

the position-step diagram.

Limit switches

a

b

c

1

2

3

4

7=1

Steps

5

Out

In

Half out

6

  5.8. The figure shows a conveyor setup for the separation of similar objects into two parallel 

transportation lines, based on the simple alternative placement of objects through the 

moving part of the conveyor. The cylinder A pushes objects on the movable part of the 

conveyor, the placement of which is altered by cylinder B. When the sensor S

1

 or S

2

 detects 

the passing of an object, then the change of the movable part placement can be performed 

according to the position-step diagram. The operation of the conveyor system starts with 

an instant START signal from a button. Similarly, the operation stops with an instant 

STOP signal from a button but only if the procedure is in the pushing phase (cylinder A in 

the extension stage). After selecting the required electro-pneumatic equipment (cylinders 

kind, directional valves, sensors, etc.), design the electric automation circuit by applying 

the state diagram method.

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