Introduction to Industrial Automation

10.29   An Electro-Pneumatic System for Pickup 

and Lay Down of Plastic Containers

Figure 10.29 shows a pickup and lay down mechanism of plastic cheese storage containers. The 

mechanism includes a special swivel bracket M

1

 that initially is in a horizontal position, a pneu-

matic valve V for creating suction (vacuum), two proximity switches that detect the horizontal 

Bulk material silo

Run

Standby

Full

Stop

Start

Level

switch

Motor

PC

Knife gate valve

+24 V DC

+24 V DC

Moto

r

Ru

n

St

andby

Full barr

el

Va

lv

e

coil

Start

Stop

PC

Level

switch

0 V

0 V

PLC

I1.0

Q4.0

Q5.0

Q6.1 Q6.2 Q6.3

I1.1

I2.0

I3.0

Inputs

Outputs

Figure 10.28  Barrel-filling machine for dry bulk material.

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Industrial Applications 

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407

and vertical position of the bracket M

1

, and the conveyor belt M

2

 for deposition and removal of 

container stacks. The sequence of evolved operations is as follows:

 

◾

With the bracket in horizontal position and by pressing the START button, a vacuum is 

created (V=On).

 

◾

The plastic container is sucked from the injection molding machine. Following a delay of 1 s, 

the bracket (M

1

) moves downward, and once detected by PS

2

, the vacuum stops (V=Off).

 

◾

Following a delay of 1 s, the bracket moves upwards.

 

◾

Once detected by the PS

1

 the vacuum is activated again (V=On), and the same process is 

repeated 10 times.

Inje

ctio

n

moldin

g

machine

FE

TA

V

M2

M1

PS

1

PS

2

M1

M2

One second delay, time interval which must be

measured in order for the next logic action to take place

PS

1

Ten

containers

PS

2

FETA

FETA

FETA

Start

1st container fell

10th container fell

Suction

Down

motion

Up

motion

Re

pe

at

10 times

V

ON

OFF

ON

OFF

3 s

+24 V DC

+24 V DC

0 V

Start

Stop

PS

1

M

1

M

1

M

2

V

Down

Up

0 V

PS

2

PLC

I0.1

Inputs

Outputs

Q2.1

Q2.2

Q3.0

Q4.0

I0.2

I3.1

I3.2

Figure 10.29  Electro-pneumatic system for pickup and lay down of plastic containers.

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408

 

◾

  Introduction to Industrial Automation

 

◾

The conveyor belt M

2

 operates for a time window of 3 s, removing the stack of 10 plastic 

containers that has been created.

 

◾

After 3 s passes, the entire process is repeated to create the second stack of containers and 

so on.

 

◾

After pressing the STOP button, at any current stage of the operation, the mechanism stops 

and the bracket comes to a horizontal position.

The exact sequence of the individual actions is illustrated in detail in the diagram shown in 

Figure 10.29. It is recommended that the required PLC program be written in Boolean or IL 

language.

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