FABRICATION OF AIR ENGINE

Submitted in the partial fulfillment of the requirement for the award of

“DIPLOMA IN MECHANICAL ENGINEERING {FOUNDRY}”

SUBMITTED BY:

1. R. VINOTH KUMAR 4. S. SOLOMAN RAJ 2. L. PRAMOSH 5. K. NEDUMARAN 3. C. N. SHANKARAN 6. S. SARAVANAN

Under guidance of

Mr. V.K.RAJENDRAN, M.E

OCTOBER 2008.

DEPARTMENT OF MECHANICAL ENGINEERING{FOUNDRY}

A M K TECHNOLOGICAL POLYTECHNIC COLLEGECHEM BARAMBAKKAM, CHENNAI – 602 103

A M K TECHNOLOGICAL POLYTECHNIC COLLEGECHEM BARAMBAKKAM, CHENNAI – 602 103

BONAFIDE CERTIFICATE

This is to certify that this Project work on

“FABRICATION OF AIR ENGINE ”

submitted by …………………… ……………. Reg. No. ……………

in partial fulfillment for the award of

DIPLOMA IN MECHANICAL ENGINEERING{FOUNDRY}

This is the bonafide record of work carried out by him under our supervision

during the year 2008

Submitted for the Viva-voce exam held on ……………..

HEAD OF THE DEPARTMENT PROJECT GUIDE

INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWLEDGEMENT

ACKNOWLEDGEMENT

At the outset, we would like to emphasize our sincere thanks to the

Principal Mr. R. J. KUMAR, B.E., M.E., MISTE., Ph.D., encouragement

and valuable advice.

we thank our Esquired Head of Department Mr R. RAJKUMAR,

A.M.I.E, M.E., for presenting his felicitations on us.

We are grateful on our Entourages Mr. V.K.RAJENDRAN, M.E.,

for guiding in various aspects of the project making it a grand success.

We also owe our sincere thanks to all staff members of the

Mechanical Engineering (FOUNDRY) Department.

Ultimately, we extend our thanks to all who had rendered their co-

operation for the success of the project.

CONTENTS

CONTENTS

Chapter No. TITLE

1. INTRODUCTION

2. SYNOPSIS

3. CONSTRUCTION

4. WORKING PRINCIPLE

5. ELECTRICAL CIRCUIT DETAILS

6. ELECTRICAL WIRING DIAGRAM

7. PNEUMATIC COMPONENTS DETAILS

8. COST ESTIMATION

9. CONCLUSION

10. BIBILOGRAPHY

INTRODUCTION

INTRODUCTION

In our technical education the project work plays a major role. Every

students is put in to simulated life particularly where the student required to

bring his knowledge, skill and experience of the project work.

It helps how to evolve specifications under given constrains by

systematic approach to the problem a construct a work device. Project work

thus integrates various skills and knowledge attainment during study and

gives orientation towards application.

As the students solve the various problems exposed by the project

work, the students get the confidence to overcome such problems in the

future life. It helps in expanding the thinking and alternatives for future

applications.

abstract

.

ABSTRACT

To increase the productivity and to overcome skilled labour

shortage, most of the manufacturing industries are going for

automation. The main aim for us to select this project work is to

acquire practical knowledge in the field of automation using

Microcontroller.

We selected “FABRICATION OF AIR ENGINE” which utilizes

the pressurized air instead of fuel. In this project ,a single cylinder

two stroke engine is used . The spark plug is removed from the

engine head and through this opening the pressurized air passed.

The pressurized air come from the compressor to the engine

through a 3/2 way directional controlled solenoid operated valve.

This valve is controlled by a electronic control system .

A infra red sensor is mounted on the top of the engine head

which sends the signal to the controller to control (ON/ OFF ) the

valve .

CONSTRUCTION

CONSTRUCTION DETAILS

This project consists of following units

1.Two stroke engine

2. Controller System

3.IR sensor unit

4. solenoid operated DC valve

1.Two stroke engine

In two stroke engine, a mixture of air and fuel or petrol is initially

drawn into crank chamber before transferring it through the transference or

scavenging port to the cylinder and combustion chamber. In order to

lubricate crankshaft connected rod bearing, cylinder wall piston rings and

gudgeon pin etc., the lubricating oil is mixed with the petrol during its filling

as there is no separated lubrication system in two stroke engines.

In two stroke engines, fresh charges of fuel is induced into the crank

chamber and he transferred in fuel in compressed in combustion chamber

with the movement of piston from BDC go to TDC. A spark is provided by

spark plug to ignite the compressed air fuel mixture when the piston reaches

near TDC. The power impulse provided by the expanding gases due to

iginition drive the piston downward from TDC towards BDC. Fresh air fuel

mixture is transferred from crank chamber to the combustion while the burnt

gases will escape to the atmosphere through the exhaust port and silencer

during the downward stroke from TDC to BDC.

There are no valves and value operating mechanism in case of two

stroke engines. Instead only ports which are opened and closed during up

and down movement of the pison are provided.

2. MICRO CONTROLLER SYSTEM:

This system monitors the engine condition by using PIC 16F870 (28

pin IC Package) micro controller. The pin details of micro controller are

shown in figure.

The circuit diagram for this micro controller board is shown below,

the I R sensor is connected to PORTB (i.e)pin no 7.The pin no 1 is

RESET switch..The valve is connected to port C .

3.IR SENSOR UNIT;

To count the jobs for the packing an I.R. sensor is used..The I.R. sensor is

fixed at the side of the cross rail which is held in taper between the two

conveyors. The jobs are passed through the IR transmitter &receiver and is

shown in fig.

4.Solenoid operated 3/2 way directional control valve;

The pressurized air passed through the Solenoid operated 3/2 way

directional control valve to the two stroke engine. This valve is controlled

ON/ OFF by the microcontroller when the IR sensor gives the signal to the

controller.

WORKING PRINCIPLE

WORKING PRINCIPLE

This project consists of Two stroke engine , Controller System,

IR sensor unit, solenoid operated DC valve .In this project, AIR

ENGINE which utilizes the pressurized air instead of fuel.

In this project ,a single cylinder two stroke engine is used . The

spark plug is removed from the engine head and through this opening

the pressurized air passed.

The pressurized air come from the compressor to the engine

through a 3/2 way directional controlled solenoid operated valve.

This valve is controlled by a electronic control system .

A infra red sensor is mounted on the top of the engine head

which sends the signal to the controller to control (ON/ OFF ) the

valve . When the piston in the cylinder reaches the TDC , the sensor

gives the signal to the controller which activates the solenoid valve.

The solenoid valve allows the pressurized air and hence

the piston moves to the BDC . Due to the inertia of force, the piston

moves to TDC and again the same process repeated. Once the

piston just moves from the TDC , the sensor sends the signal to the

controller which switch off solenoid valve .

ELECTRICAL CIRCUIT DETAILS

ELECTRICAL CIRCUIT DETAIL

1. Micro controller system

2. Interface Circuit

3. Power supply (230V A.C. to 12 V and 5V DC)

MICRO CONTROLLER SYSTEM:

This system monitors the engine condition by using PIC 16F870 (28

pin IC Package) micro controller. The pin details of micro controller are

shown in figure.

The circuit diagram for this micro controller board is shown below,

the LDR sensor is connected to PORTA (i.e)pin no 2&5.The pin no 1 is

RESET switch..The bulbs are connected to port B .

POWER SUPPLY UNIT

INTRODUCTION:

All the electronic components starting from diode to Intel IC’s only

work with a DC supply ranging from +5V to +12V. We are utilizing for the

same, the cheapest and commonly available energy source of 230V-50Hz

and stepping down, rectifying, filtering and regulating the voltage.

STEP DOWN TRANSFORMER:

When AC is applied to the primary winding of the power transformer,

it can either be stepped down or stepped up depending on the value of DC

needed. In our circuit the transformer of 230V/15-0-15V is used to perform

the step down operation where a 230V AC appears as 15V AC across the

secondary winding. Apart from stepping down voltages, it gives isolation

between the power source and power supply circuitries.

RECTIFIER UNIT:

In the power supply unit, rectification is normally achieved using a

solid state diode. Diode has the property that will let the electron flow easily

in one direction at proper biasing condition. As AC is applied to the diode,

electrons only flow when the anode and cathode is negative. Reversing the

polarity of voltage will not permit electron flow. A commonly used circuit

for supplying large amounts of DCpower is the bridge rectifier. A bridge

rectifier of four diodes (4 x IN4007) are used to achieve full wave

rectification. Two diodes will conduct during the negative cycle and the

other two will conduct during the positive half cycle, and only one diode

conducts. At the same time one of the other two diodes conducts for the

negative voltage that is applied from the bottom winding due to the forward

bias for that diode. In this circuit due to positive half cycle D1 & D2 will

conduct to give 0.8V pulsating DC. The DC output has a ripple frequency

of 100Hz. Since each alteration produces a resulting output pulse, frequency

= 2 x 50 Hz. The output obtained is not a pure DC and therefore filtration

has to be done.

The DC voltage appearing across the output terminals of the bridge

rectifier will be somewhat less than 90% of the applied rms value. Normally

one alteration of the input voltage will reverse the polarities. Opposite ends

of the transformer will therefore always be 180 degree out of phase with

each other. For a positive cycle, two diodes are connected to the positive

voltage at the top winding.

FILTERING CIRCUIT:

Filter circuits which is usually capacitor acting as a surge arrester

always follow the rectifier unit. This capacitor is also called as a decoupling

capacitor or a bypassing capacitor, is used not only to ‘short’ the ripple with

frequency of 120Hz to ground but also to leave the frequency of the DC to

appear at the output. A load resistor R1 is connected so that a reference to

the ground is maintained. C1, R1 is for bypassing ripples. C2, R2 is used as

a low pass filter, i.e. it passes only low frequency signals and bypasses high

frequency signals. The load resistor should be 1% to 2.5% of the load.

1000f/25V : for the reduction of ripples from the pulsating

10f/25V : for maintaining the stability of the voltage at the load side.

0.1f : for bypassing the high frequency disturbances

BLOCK DIAGRAM FOR POWER SUPPLY

STEP DOWN BRIDGE POSITIVETRANSFORMER RECTIFIER CHARGE

CAPACITOR

5V 12V REGULATOR REGULATOR

MOTHER DISPLAY BOARD BOARD RELAY

VOLTAGE REGULATOR:

The voltage regulators play an important role in any power supply

unit. The primary purpose of a regulator is to aid the rectifier and filter

circuit in providing a constant DC voltage to the device. Power supplies

without regulators have an inherent problem of changing DC voltage values

due to variations in the load or due to fluctuations in the AC linear voltage.

With a regulator connected to the DC output, the voltage can be maintained

within a close tolerant region of the desired output. IC7812 and 7912 is

used in this project for providing +12V and 12V DC supply.

SPECIFICATION:

Resistors R1 and R2 maintain line load regulation.

At the secondary side of the transformer, applied vlltage = 15V

Conducting drop across the diodes = 2 * 0.6 = 1.2V

Without capacitor:

Vavg = (15-1.2)V = 13.8c pulsating DC

Frequency = 100Hz

With capacitor:

V = Vavg * 1.414 (form factor) = 19.51V

Frequency = 0 Hz

with 7812 voltage regulator:

V0 = +12V

with 7912 voltage regulator: V0 = -12V

DESCRIPTIONOF PNEUMATIC

COMPONENTS

PNEUMATIC COMPONENTS

In engineering field, many machines make use of fluid for developing

a force to move or hold an object. A number of fluid can be used in

devices and system. Two commonly used fluids are oil and compressed

air. A system which is operated by compressed air. A system which is

operated by compressed air is know as pneumatic system.

AIR COMPRESSOR

Compressor is a device which gets air fro the atmosphere and

compresses it for increasing the pressure of air. Thus the compressed air.

Thus the compressed air used for many application.

The compression process requires work in put. Hence a compressor is

driven by a prime mover. Generally an electric motor is used as prime

mover. The compressed air from compressor is stored in vessel called

reservoir. Fro reservoir it be conveyed to the desired place through pipe

lines.

2. FLTER

In pneumatic system, an air filter is used to remove all foreign matter.

An air filter dry clean air to flow without resistance various materials are

used for the filter element. The air may be passed thorugh a piece metal, a

pours stone felt resin impregnated paper. In some filters centrifugal action

or cyclone action is used to remove foreign matters.

3. PRESSURE REGULATOR

Constant pressure level is required for the trouble free operation of a

pneumatic control., A pressure regulator is fitted downstream of the

compressed air filter. It provides a constant set pressure at the outlet of the

outlet of the regulator. The pressure regulator is also called as pressure

reducing valve or pressure regulating valve.

4. LUBRICATOR

The purpose of an air lubricator is to provide the pneumatic

components with sufficient lubricant. These lubricants must reduce the wear

of the moving parts reduce frictional forces and protect the equipment from

corrosion.

Care should be taken to ensure that sufficient lubrication is provided.

But excessive lubrication should be avoided. .

5. FLR Package (or) FRL Package

The air service unit is a combination of following units.

1. Compressed air filter

2. Compressed air regulator

3. Compressed air lubricator

Air Filter, regulator and lubricator are connected together with close

nipples as one package. This unit is know as FLR (Filter, regulator,

lubricator.)

1. Double acting air cylinder with piston arrangement.

2. Spool valve (2 position 5 ports valve)

3. Pneumatic fittings

a. Bulk head union

b. Flexible hoses

c. Air compressors

DOUBLE ACTING AIR CYLINDER WITH PISTON

ARRANGEMENT:

It consists of a piston inside a cylindrical housing called a

barrel. Attached to one end of the piston is a rod which the rod end

has one port. This rod end port is used for entrance of air and

extends outside one end of the cylinder. At another end is a port for

exit of air.

Double acting cylinder can be extended and retracted

pneumatically. The smallest bore size of an double acting cylinder is

1 1/8 inch. The piston, which is made of ductile Iron, contains u-cup

packing to seal against leakage between the piston and barrel. The

ports are located in the end caps, which are secured to the barrel by

bolts and nuts.

DIRECTING CONTROL VALVES:

A direction control valve is used to change the direction of air

flow as and when required by the system for reversing the machine

tool devices. A direction control valve may be classified, according to

the construction of the internal moving parts, as

1. Rotary spool Type.

2. Sliding Spool Type.

3. Solenoid operated valves

SOLENOID OPERATED VALVES:

Solenoid valves are electromechanical devices like relays and

contractors. A solenoid valve is used to obtain mechanical movement in

machinery by utilizing fluid or air pressure. The fluid or air pressure is

applied to the cylinder piston through a valve operated by a cylindrical

electrical coil. The electrical coil along with its frame and plunger is known

as the solenoid and the assembly of solenoid and mechanical valve is known

as solenoid valve. The solenoid valve is thus another important

electromechanical device used in control of machines. Solenoid valves are

of two types,

1. Single solenoid spring return operating valve,(5/2)

2. Double solenoid operating valve.

In fig 1 is shown a single solenoid spring return valve in its de-energized

condition. The symbol for the solenoid and the return are also shown. The

solenoid valve is shown connected to the cylinder to help readers understand

the solenoid valve action.

In the de energized condition, the plunger and the valve spool position as

shown in figure 1.

In this position of spool, port P is connected to port A and port B is

connected to tank or exhaust (i.e. atmosphere) if air is used. Spring pressure

(S) keeps the spool in this condition as long as the coil is de energized.

Fluid pressure from port P through port A is applied to the left side of the

cylinder piston. Thus the cylinder piston moves in the right direction.

Now when the solenoid coil is energized, plunger is attracted and it pushes

the spool against spring pressure.

The new position of plunger and spool are shown in fig 2.

In this position of spool, port A gets connected to tank and port P

gets connected to port B. Thus pressure is applied to the cylinder

piston from right and moves the piston rod to the left. At the same

time fluid in the other side is drained out to the tank. When the

solenoid coil is again de energized, the spring (S) will move the spool

to its original position as shown in figure 1. Thus, normally when the

solenoid coil is de energized the piston rod remains extended.

PNEUMATICFITTING

PNEUMATIC FITTINGS:

There are no nuts to tighten the tube to the fittings as in the

conventional type of metallic fittings. The tube is connected to the fitting by

a simple push ensuring leak proof connection and can be released by

pressing the cap and does not require any special tooling like spanner to

connect (or) disconnect the tube from the fitting.

SPECIFICATION OF THE FITTING:

Body Material - Plastic

Collect/Thread Nipple - Brass

Seal - Nitrate Rubber

Fluid Used - Air

Max. Operating Pressure - 7 Bar

Tolerance on OD of the tubes - 1 mm

Min. Wall thickness of tubes - 1 mm.

FLEXIBLE HOSES:

The Pneumatic hoses, which is used when pneumatic components

such as actuators are subjected to movement. Hose is fabricated in layer of

Elastomer or synthetic rubber, which permits operation at high pressure.

The standard outside diameter of tubing is 1/16 inch. If the hose is subjected

to rubbing, it should be encased in a protective sleeve.

ADVANTAGES AND LIMITATIONS

ADVANTAGES:

The Pneumatic arm is more efficient in the technical field

Quick response is achieved

Simple in constructions

Easy to maintain and repair

Cost of the unit is less when compared to other robotics

No fire hazard problem due to over loading

Comparatively the operation cost is less

The operation of arm is faster because the media to operate is air

Continuous operation is possible without stopping.

LIMITATIONS:

High torque cannot be obtained.

Load Carrying capacity of this unit is not very high (3 – 5 kg/s)

Silencer may be used, to reduce the noise of compressed air

APPLICATION

1) DISCHARGE OF WORKPIECE:

The arm fed has wide application in low cost automation. It can be

used in automated assembly lines to pick-up the finished product from

workstation and place them in the bins. It can also be used to pick-up the

raw material and place them on the conveyor belts and vice versa.

2) JOB CLAMPING:

This unit can also be used in clamping operations in certain areas of

mass productions where clamping and unclamping have to be done at high

speeds. The application of this unit is limited to operations, which involves

moderate clamping forces.

3) TRANSFER OF JOBS BETWEEN WORK STATIONS:

The gripping method used in a low cost automation to move the work

piece from one workstation to another. The combination of an angular

rotary motion is the principle behind this method. The gripper holds the

work rigidly. The to and fro motion is achieved by means of the actuating

cylinder.

4) TOOL CHANGING APPLICATION:

When the pneumatic arms are made smaller in size they can be used

in automatic tool changer in CNC turning and drilling machines, by

attaching suitable tool holding device to the rotary cylinder.

SPARE PARTS AND ASSEMBLY DRAWING

ADVANTAGES

COST ESTIMATION

COST ESTIMATION

1. Microprocessor control Board ---------------------- 3000.00

2. DC. Solenoid valve (1 No)-------------------- 1500.00

3. IR sensor ----------------------------------------------- 600.00

4. Push button, Wires, & Jack Connectors------------ 200.00

5. Two stroke engine --------------------- 1600.00

6. Valve connectors 3 nos--------------- 300.00

7. brass nipple for air inlet to engine---------- 100.00

8. M.S. Fabricated stand --------------------- 600.00

9. Primer and Enamel paint ---1/2 litres------ 200.00

_______________

Total 8100.00

_______________

CONCLUSION

CONCLUSION

We make this project entirely different from other projects. Since

concepts involved in our project is entirely different that a single unit is used

to various purposes, which is not developed by any of other team members.

By doing this project we gained the knowledge of pneumatic system

and how automation can be effectively done with the help of pneumatic

system.

It is concluded that any automation system can be done with the help

of micro controller & pneumatic system.

We have successfully completed the project work on using pneumatic

control at our Institute.

By doing this project work, we understood the working principle and

uses of various controls, switches, relays etc.

It will be of no doubt that pneumatic system will be an integrated part

of any automation process in any industry.

Once again we express our sincere thanks to our staff members.

BIBILOGRAPHY

BIBILOGRAPHY

1. Low cost automation with pneumatics - FESTO

2. Electro pneumatics - FESTO

3. Hydraulics & pneumatics for Power Production - Harry L – Stewart

4. Basic pneumatics - FESTO

5. www.google.com

6. Workshop Technology - Hajra Chowdry

7. Production Technology -R.S. Khurmi

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