Lifting and pushing cylinder pneumatic system

Lifting and pushing cylinders pneumatic system:Seminar

Lifting and pushing cylinder pneumaticsystem

1. Introduction in Pneumatics :

Pneumatics has for some considerable time been

used for carrying out the simplest mechanical tasks, but in

more recent times has played a more important role in the

development of pneumatic technology for automation.

In the majority of applications compressed air is used for

one or more of the following functions:

• To determine the status of processors (sensors(

• Information processing (processors(

• Switching of actuators by means of final control

elements

• Carrying out work (actuators(

To be able to control machinery and installations

necessitates the construction of a generally complex logic

interconnection of statuses and switching conditions. This

occurs as a result of the interaction of sensors,

processors, control elements and actuators in pneumatic or

partly pneumatic systems.

The technological progress made in material, design and

production processes has further improved the quality and

diversity of pneumatic components and thereb7 contributed

to their widely spread use in automation.

The pneumatic cylinder has a significant role as a linear

drive unit, due

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to its

• relatively low cost,

• ease of installation,

• simple and robust construction and

• ready availability in various sizes and stroke lengths.

The pneumatic cylinder has the following general

characteristics:

• Diameters 2.5 to 320 mm

• Stroke lengths 1 to 2000 mm

• Available forces 2 to 45000 N at 6 bar

• Piston speed 0.1 to 1.5 m/s

Pneumatic components can perform the following types of

motion:

Linear

Swivel

Rotary

Some industrial applications employing pneumatics are

listed below:

General methods of material handling:

Clamping

Shifting

Positioning

Orienting

Branching of material flow

General applications:

Packaging

Filling

2


Metering

Locking

Driving of axes

Door or chute control

Transfer of materials

Turning and inverting of parts

Sorting of parts

Stacking of components

Stamping and embossing of components

Pneumatics is used in carrying out matching and working

operations.

For example:

Drilling

Turning

Milling

Sawing

Finishing

Forming

Quality control

2. Lifting and pushing cylinder pneumatic system :

2.1. The mechanism and operation circuit :

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This subject provides knowledge and information to

understand the mechanism of transfusion productions

pneumatically with a mechanical, scientific analysis and

description.

2.1.1. Schematic layout of blocking, lifting and pushing cylinders :

The mechanism in side

(Fig. 2.1) consists of

three cylinders to

elevate and pushing the

(pieces) and two chutes

to drop and transfer the

pieces. The pieces comes

from the right chute

dropping to the cylinder

table, once then the

barrier of cylinder (3)

prevent the pieces

dropping down once they

have been lifted into the

table of cylinder (1),

then cylinder (1) elevated

the pieces which are

pushed by cylinder (2) to

the left chute; The

mechanism parts then

4

1

2

3

msinahcem ehT 1.2 .giF


continues operating in a

cyclic order.

3. operation circuit diagrams :

3.1.Displacement-step Diagram :

The displacement-step diagram(Fig 3.1) is used for motion

sequences and represents the operating sequences of

actuators; the displacement is recorded in relation to the

sequence step.

In this case there are three cylinders 1A,2A and 3A.in

step ( 1 )cylinder 3A retracted and then cylinder 1A

extends in step ( 2 ).in step ( 3 ) cylinder 2A extends

and both cylinder 1A and 2A retracted in step (4). in

step ( 5 ) cylinder 3A retracted again to commence the

circulation.

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Fig. 3.1 Displacement-step diagram

3.2. Control chart :

In the control chart, the switching status of the control

element is represented in relation to the steps.

The Control diagram below (Fig. 3.2) show the statuses of

the control components 1V1 for cylinder 1A and

operating valve 0.2 and the status of the limit

switches 2.1 , 3.1 , 3.1 , 1.1 and 1.2.

up1 2 3 4 5 6=1

1A

2A

3A

advance

up

down

return

down

StepsDisplacement

2.1

3.11.2

1.1

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Fig. 3.2 control chart

3.3. Function Diagram :

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1V1

1.1

1.2

2.1

3.1

0.2

1 2 3 4 5 6=1open

closeopen

open

close

close

open

closeopen

closeopen

close

Steps

Status


The function diagram (fig. 3.3) is a combination of the

motion diagram and the control chart. The lines

representing the individual states are referred to as

function lines.

8

1 2 3 4 5 6=11

010

1A

2Aِِ

2.1

10

101

010101

0

1

3A

1v1

1.1

1.2

2.1

3.1

0.2


Fig. 3.3

function diagram

3.4. Function Chart :

The function chart (fig. 3.4) gives a clear picture of

action, and reactions in sequences. The diagram describes the following sequence:

Barrier cylinder 3A is retracted (3A-) and limit valve then

operated is 1.1 (3A extend directly with its return

spring). (step 1 )

This limit 1.1 initiates the extension of cylinder 1A

(1A+) and the limit valve 2.1 is operated. (step 2 )

This limit 2.1 initiate the extension of cylinder 2A

(2A+) which actuate the valve 1.2 . (step 3 )

This limit 1.2 initiates the retraction of 1A (1A-). (2A

retracting automatically via roller valve with its

return spring). (step4)

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The full retraction of 1A is indicated by 3.1 and this

is the initial condition required for a new cycle to

commence.

10

0

from step

4

S0.2

1S

3A- 1.11.1

2S

A3+S

A1+ 1.21.2

3S

A2+ 2.12.1

4S

A1- 1.3SA2-

1 pets otgiFtiucric eht fo margaid trahC noitcnuF 4.3 .


4. Pneumatic circuit diagram :

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Fig. 4.1 Circuit diagram

5. Component description:

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5.1. Compressed air supply:

The compressed air supply (fig. 5.1) provides the needed

compressed air. It contains a pressure control valve

that can be adjusted to output the desired operating

pressure. (Note: the compressed air must be filtration,

separated and provides with oil vapors to reduce the

friction due to sliding of moving parts via Air service

unit )

Adjustable parameters:

Operating pressure: 0…..20 bar (6 bar).

5.1.1. Compressed air supply, piston compressor :

The piston compressor (Fig. 5.2) is widely used

. Multi-stage compressors are required

for compressing to high pressure.

The drawn in air is compressed by the first piston,

cooled and then compressed further by the next stage.

5.1.2. Compressed air supply, axial flow compressor :Flow compressors produce large volumes of air

at small increases in stage pressure.

The air is accelerated by the blades of

the compressor but there is only a small

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Fig 5.2 piston compressor

Fig. 5.3 Axial flow compressor

ylppus ria desserpmoC 1.5 .giF


increase in pressure (Fig. 5.3).

5.2. Valves in use :

5.2.1. The operating Valve (manually switching) :

This valve of 3/2-way (Fig. 5.4) change in it's two

position manually it's rod moves left and right and

remain in the actuated position until it actuated

handedly again.

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2

The valve actuatedfrom left to right, the air flow from (1) to(2)so its in an switch on position.

1

The valve actuated from right to left,hence (2) connecting with exit (3) so it’s inan switch off position.

5.2.2. directional control valve:

The 4/2-way directional control valve (Fig. 5.5)

consists of one enter 1 and tow exits 4 and 2,

this valve change it's position by a signal actuates

from side A or B.

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Fig. 5.4 operating Valve (manually switching)


If an air signalactuates from B, the air flow from 1 to 2 and 4 connectswith exit 3.

If an air signal actuates from A, the air flow from 1 to 4 and 2 connects with exit3.

5.2.3. 3/2-way roller lever valve, normally closed:

The roller lever valve (Fig 5.6) is operated by pressing

on the lever, for example through the use of a switching

cam of a cylinder. The flow passes through from 1 to 2.

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Fig 5.5 4/2-way directional control valve


After releasing the lever, the valve returns to its

initial position through the use of a return spring.

Connection 1 is shut.

In the Simulation Mode, the valve can be switched

manually by clicking on the component, thus not

requiring a cylinder to operate the valve

The flow pass from1 to 2.

Connection 1is shut.

5.2.4. 4/2-way roller lever valve, normally closed:

It has the same principle operation of (3/2-way roller

valve ), where The roller lever is operated by pressing

on the lever , The flow passes through from 1 to 4.

After releasing the lever, the valve returns to its

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Fig. 5.6 3/2-way roller valve


initial position through the use of a return spring

(Fig. 5.7).

5.2.5. One-way flow control valve:The one-way flow control valve (Fig. 5.8) is made up of a

throttle valve and a check valve. The check valve stops the

flow from passing in a certain direction. The flow then

passes though the throttle valve. The cross-section of the

throttle is adjustable via a regular screw. In the opposite

direction the flow can pass through the check

valve.Adjustable parameters

The 4/2 valve isactuate, and there is flow from 1to 4 and from 1 to 2.

The 4/2 valve before actuated.

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Fig. 5.7 4/2-way roller valve


Opening level: 0…..100% (100%)

5.3. Cylinders in use:5.3. Cylinders in use:

5.3.1. Single acting cylinder with return spring:

The piston of the single acting cylinder is extended to

its back position by the input of compressed air. When

the compressed air is switched off, a return spring

moves the piston back to its front position (Fig. 5.9).

Adjustable parameters:Max. stroke: 1 … 100 mm (50mm)Piston position: 0 … Max. stroke mm (50mm)Piston Area: 0.07 …. 80 qcm

(3.14 qcm)Piston Ring Area: 0.03 …. 65qcm

(2.27 qcm)

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Fig. 5.8 one-way flow control valve fo noitces tnorF wol f yaw-eno

evlav lortnoc


The piston extend out via the airpressure.

The piston back to its frontposition

via a return spring .

Fig. 5.9 Single acting cylinder with return spring

5.3.2. Double acting cylinder

The piston rod of a double acting cylinder is operated by

the reciprocal input of compressed air at the front and

back of the cylinder. The end position damping is

adjustable via two regular screws (Fig. 5.10). The piston

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of the cylinder contains a permanent solenoid which can be

used to operate a proximity switch.

Adjustable parameters

Max. stroke: 1 ... 5000 mm (100 mm)

Piston position: 0 … Max. stroke mm (0 mm)

Piston Area: 0.25 … 810 qcm (3.14 qcm)Piston Ring Area: 0.1 … 750 qcm

(2.27 qcm)

Cushioning in double acting cylinderIf large masses are moved by a cylinder, cushioning is used

in the end positions. Before reaching the end position, a

cushioning piston interrupts the direct flow of air to the

outside. For the last part of the stroke the speed is

slowed to reduce impact on the cylinder.

21Fig .5.10 double acting cylinder in a reciprocal input of

compressed air


5.4. Distance ruleThe distance rule (Fig. 5.11) is a device for attaching

switches at the cylinder. The labels at the distance rule

define links to the actual proximity switches or limit

switches in the electrical circuit

6. Pneumatic system software:

FluidSIM-P is a teaching tool for simulating pneumatics

basics and runs using Microsoft Windows ©. It can be used

in combination with the Festo Didactic GmbH & Co. KG

training hardware, but also independently. FluidSIM was

developed as a joint venture between the University of

Paderborn, Festo Didactic GmbH & Co. KG, and Art Systems

Software GmbH, Paderborn.

A major feature of FluidSIM is its close connection with

CAD (Computer Aided Design) functionality and simulation.

FluidSIM allows DIN-compliant drawing of electro-pneumatic

circuit diagrams and can perform realistic simulations of

the drawing based on physical models of the components.

Simply stated, this eliminates the gap between the drawing

of a circuit diagram and the simulation of the related

pneumatic system.

The CAD functionality of FluidSIM has been specially

tailored for fluidics. For example, while drawing

, the program will check whether or not certain connections

between components are permissible.

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Fig 5.11 distance

rule


Another feature of FluidSIM results from its well thought-

out didactic concept: FluidSIM supports learning,

educating, and visualizing pneumatic knowledge. Pneumatic

components are explained with textual descriptions,

figures, and animations that illustrate underlying working

principles; exercises and educational films mediate

knowledge about both important circuits and the usage of

pneumatic components.

The following steps below illustrate how the mechanism of

lifting and pushing cylinder run by FluidSIM-P:

6.1. Pneumatic circuit diagram for the three actuator :

23 The Circuit before operating High pressure flow. Low pressure flow.


If the emergency valve switched handily, then the piston rod of the cylinder 3A retracted. (Note: This cylinder extends by its return spring).

When the cylinder 3A reaches its retracted end position,

the limit switch 1.1 is actuated and the piston of

cylinder 1A advances (note the actuating of limiting 1.1

actuated by the ensure of the piece dropping not by 3A).

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The Circuit before operating High pressure flow. Low pressure flow.

3A retracts

3A reaches the end position and 1.1

actuated

1A advanced, 3A advanced


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When the cylinder 1A reaches its forward end position,

the limit switch 2.1 is actuated and the piston rod of

cylinder 2A advances. (Note: cylinder 1A maintained at

its forward position).

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1A reaches the end position and 2.1

actuated

1A remains in its position and 2A

advanced


When the cylinder 2A reaches its forward end position,

the limit switch 1.2 is actuated and both two cylinders

1A and 2A retracted to their initial position. (Note:

cylinder 2A retracted automatically via roller lever

valve with its return spring).

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2A reaches its end position and 1.2

actuated

Both 1A, 2A retracted


When the cylinder 1A reaches its retracted end position,

the limit switch 3.1 is actuated and hence the piston

rod of the cylinder 3A retracted and the limiting 1.1

actuated by the ensure of the piece dropping to

commence cyclic motion.

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1A reaches its end position and 3.1

actuated


The signal for advancing is designated using a '+' and

the signal for retracting using a '-' .

The sequence 3A- 1A+ 2A+ 1A- 2A- is to be read as:

cylinder 3A retracts, cylinder 1A advances, cylinder 2A

advances, cylinder 1A retracts and cylinder 2A retracts.

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3A retracted until it reach its initial position;continues operating in acyclic order.


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Lifting and pushing cylinder pneumatic system

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