Report: Pneumatic UTM

7/29/2019 Report: Pneumatic UTM

1/14

1

TOPIC

Pneumatics

INTRODUCTION

Pneumatics is the science of mechanical properties of elastic fluids. In industry, Pneumatic

generally refers to use of compressed air to transmit power and/or motion.

OBJECTIVES

1. Understand the basic principle of pneumatics and its application.2. Describe and identify the different types andfunctions of pneumatics components.3. Read and construct simple pneumatics circuits.

ADVANTAGES OF PNEUMATICS1. Air is available everywhere in unlimited quantities.2. Air can be easily transported tin pipelines, even over large distance3. Compressed air can be stored in reservoir and removed as required.4.

Compressed air is relatively insentive to temperature fluctuations. This ensures reliableoperation, even under extreme conditions.

5. Compresses air offers no risk of explosion or fire6. Unlubricated exhaust is clean. Any unlubricated air which escapes through leaking pipes

or components does not cause contamination.

7. Compressed air is very fast working medium.8. Pneumatic tools and operating components can be loaded to the point of stopping and

therefore overload safe.

DISADVANTAGES OF PNEUMATICS1. Compressed air required good preparation. Dirt and condensate should not be present.2. It is always possible to achieve uniform and constant piston speeds with compressed air.3. Compressed air is economical up to a certain force requirement. Under the normal

working pressure of 600 to 700 kPa and dependent on the travel and speed, the outputlimit os between 40000 and 50000N.

4. The exhaust air is loud. This problem has now, however been largely solved due to thedevelopment of sound absorption material and silencers.

Types Of Pneumatic :

1. Manual pneumatic.2. Electro-pneumatic.3. PLC (Program Logic Controller).


2/14

2

Types Of Valves :

1. DCV (Direction Controlled Valve).- Units that provide full or restricted flow by opening or closing of one or more

paths(one or several squares).

Flow Paths

One flow path

Two closed ports

Two flow paths

Two flow paths and one closed port

Two flow paths with cross connection

One flow path in a bypass position, two closed ports

Non-throttling directional control valve

Two position would have distinct circuit conditions shown in

each square

Three position would have distinct circuit conditions shown in

each square

Transitory position significant position passed through while

switching positions optionally shown by dashed lines

Directional control valve 2/2

Manual control directional control valve with 2 ports and 2distinct postions.

Controlled by pressure operating against a spring (ex. airunloading valve)directional control valve with 2 ports and 2

distinct postions.


Controlled by pressure in both directions directional control

valve with 3 ports and 2 distinct postions.

Controlled by solenoid with spring return (showing transitory

position)directional control valve with 3 ports and 2 distinct

postions.


3/14

3


Detailed Pic- directional control valve with 4 ports and 2 distinct

postions controlled by pressure in both directions by means ofpilot valve (with single solenoid and spring return)

Simplified Pic- directional control valve with 4 ports and 2

distinct postions controlled by pressure in both directions by

means of pilot valve (with single solenoid and spring return)


Controlled by pressure in both directions- directional control

valve with 5 ports and 2 distinct postions

Throttling directional controlTwo extreme positions- unit has 2 extreme positions and an

infinite number of intermediate conditions with varying degrees

of throttle)

Shows the extreme positions and a central(neutral) position-

Two ports(one throttling orifice) ex. -tracer valve plunger

operated against a return spring

Three ports(two throttling orifices) ex. -directional control valve

controlled by pressure against a spring return

Four ports(four throttling orifices)- ex. --tracer valve plungeroperated against a return spring

Electro-hydraulic servo valve

Single-stage direct operation unit which accepts an analog signal

and provides a similar analog fluid power output

Two-stage with mechnical feedback indirect pilot operation unitwhich accepts an analog signal and provides a similar analog

fluid power output

Two-stage with hydraulic feedback indirect pilot operation unit

which accepts an analog signal and provides a similar analogfluid power output


4/14

4

2. PCV (Pressure Controlled Valve).

Pressure Control Valve

One normally closed throttling orifice (general

symbol)

One normally open throttling orifice (general symbol)

Two normally closed throttling orifices (general

symbol)

Pressure Relief Valve(safety valve)

Inlet pressure is controlled by opening the exhaust portto the reservoir or to atmosphere against an opposing

force (for example a spring).

With remote pilot control the pressure at the inlet port

is limited to the setting of a pilot control

Proportional Pressure Relief

Inlet pressure is limited to a value proportional to the

pilot pressure

Sequence Valve

When the inlet pressure overcomes the opposing force

of the spring, the valve opens permitting flow from the

outlet port

Pressure regulator or Reducing valve

A unit which , with a pressure variable inlet pressure,gives substantially constant output pressure provided

that the inlet pressure remains higher than the required

outlet pressure

Without relief port

Without relief port with remote control but the outletpressure is dependent on the pressure control

With relief port

With relief port with remote control but the outlet

pressure is dependent on the pressure control


5/14

5

Differential pressure regulator

The outlet pressure is reduced by a fixed amount with

respect to the inlet pressure

Proportional pressure regulator

The outlet pressure is reduced by a fixed ratio with

respect to the inlet pressure

3. FCV (Flow Controlled Valve).

Throttle valve

Simplified symbol (doesn't show the control method or state ofvalve)

With manual control detailed(shows control method)

With mechanical control against a spring return detailed(showscontrol method) ex.-(braking valve)

Flow Control valve

With fixed output (variations in inlet pressure do not affect rate of

flow)

With fixed output and relief port to reservoir with relief forexcess flow (variations in inlet pressure do not affect rate offlow)

With variable output

With variable output and relief port to reservoir

Flow dividing valve

The flow is divided into two flow in a fixed ratio substanially

independent or pressure variations


6/14

6

Introduction of Symbol :

P (1)Pressure port A (4) and B (2)Signals output Z (14) and Y (12)Pilot line opens flow R (3) and S (5)Exhaust port

Example of symbols of pneumatic :

2/2 Valve; 2 Ports, 2

Positions


Positions


Positions

4/3 Valve; 4 Ports, 3Positions



Accumulator Air DryerAir Motor (One

Directional Flow)

Air Motor (Two

Directional Flows)

Check Valve (Spring

Loaded)Compressor


7/14

7

Cylinder (Spring

Return)

Cylinder DoubleActing

(Double Rod)

Cylinder Double Acting

(Single Fixed Cushion)

Cylinder Double

Acting

(Two AdjustableCushions)

Differential Pressure Direction of Flow

Exhaust Line or

Control Line Filters and Regulators

Filter (Automatic

Drain)

Filter (Manual Drain) Fixed Restriction Flexible Line

Flow Control Valve Flow Gauge Lever

Lines Connected Lines Crossing Lubricator

Muscular Control

One Bypass Flow

Path andTwo Closed Ports

One Flow Path

Pedal or Treadle Pilot Pressure(External)

Pilot Pressure (Internal)

Plugged PortPlunger or Position

Indicator PinPneumatic


8/14

8

Pressure Actuated

Electric Switch

Pressure Gauge Pressure Regulator

(Adjustable, Non-Relieving)

Pressure Regulator

(Adjustable, Self-

Relieving)

Pushbutton Quick Acting Coupling

Roller Roller (One-Way) Shuttle Valve

Silencer Single SquareSolenoid and Pilot;

Manual Override and

Pilot

Solenoid (Single

Winding)Spring Two Closed Ports

Two DistinctPositions and

One Transitory

(Center) Position

Two Flow PathsTwo Flow Paths and

One Closed Port

Two Flow Paths with

Cross ConnectionVacuum Pump Variable Restriction

Working Line


9/14

9

Components Used In Building Circuit

Components Symbol Fuction

Single Acting Cylinder Push out when

compressed air go

into and returnedby spring force.

Double Acting Cylinder Single piston rod,

require fluid to

extend and retract.

Push Button Directional ControlValve3/2

Change the wayof flow by click

on the button

Mechanical Directional ControlValve3/2

Change the wayof flow by clickon the switch.


10/14

10

Directional Control Valve4/2

Recycle the

exhausted gas.

(Due to the

workshop lack ofdirectional control

valve 4/2, we usea tee-shapeconnector to

connect two pipe

as figure shown)

Directional Control Valve5/2 Control the flowof fluid entering

and exiting.

Adjustable Flow Control Valve /

Throttle Valve

Control the flow

enter and pass

through.

Timer As the countdown

device to control

times of flow

Distributor Distribute the

source of fluid to

many parts.


11/14

11

Tee-Shaped Connector Connect three

pipe together.

Shuttle Valve Allow only a

direction of flow

at one time

Pipe Allow the flow of

fluid.


12/14

12

INSTALLATION OF PNEUMATIC CIRCUIT

Type of control

1. Direct control

The 1st

circuit is just a simple circuit. When the push button is pressed, the cylinder rod of singleacting cylinder will pushed out. And when the push button is released, the cylinder rod will

return back by extended by spring inside.

2. Indirect control

When the start push button is pressed, the cylinder rod will pushed out, but the cylinder rod won't

returned back itself. When the stop push button is pressed, the cylinder rod will returned back.

3. Single cycle processSingle cycle process means that the functional steps sequence of any machine will be

perform only when the machine starts.

4. Multiple cycle processMultiple cycle process means that the functional steps of any machine will be performed

continuosly when the machine starts.


13/14

13

CIRCUIT

This is a single Actuator with introducing the roller limit switch(Automation movement).It

consist a cylinder rod,2 censors, a 5/2 way directional control valve and a push button. The

cylinder rod wil push out when push button is pressed. Cylinder rod will automatically returned

back and stop when it touched the censors.

DISCUSSION1. When connecting the pipe with the ports, the pipe must be confirmed push into tightly.

That is because if the pipes are not connected tightly, the pressure of the flow is not

enough high. The actuator will not completely function if the minimum pressure of flowdo not reach.

2. when want to unplug the pipes from the devices, the source of the fluid has to cut offbefore. If the source do not cut off first, when the pipes disconnected, the pipes will fliedrandomly.


14/14

14

CONCLUSION

Pneumatics are very important in industrial uses. In industry, many hard work need to do,such as clamping,transferring,shifting,stamping,pressing and embossing.

In daily life, we can also see the tools using hydraulics or pneumatics system. Such as

forklift that can be seen at the building stage. So, fluid power is now become more important. Infuture, fluid power may be integrated with the daily life.

REFERENCES

www.pdf-search-engine.com/

Date post:	04-Apr-2018
Category:	Documents
Upload:	adibah-ismail
View:	213 times
Download:	0 times

Report: Pneumatic UTM

Documents