2-STROKE INTERNAL COMBUSTION ENGINE ELEMENTS OF MECHANICAL

ENGINEERING

KAUSHAL PATEL

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SPECIFICATIONS

Type Two stroke, Air cooled, S.I engine

Bore × Stroke, mm 57/57 No. of Cylinder 1 Displacement 145.45 cc Compression ratio 10±0.7:1 Max. Power @ rpm 4.9 kW @ 5000 rpm Max. Torque @ rpm 10.8 N/m @ 3500 rpm Clutch Type Wet multidisc Transmission 4 Forward, 1 Reverse Fuel Bifuel(CNG as main)

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PISTON

Piston is reciprocating part of internal combustion

engine. Piston of this engine consist of two piston rings

one for compression and other for lubrication. One

hemispherical surface is on top of piston. Piston is hollow

from bottom. Below the piston pin one hole for transfer

fresh charge from crank case to combustion chamber.

Connecting rod is connected to the piston pin.

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CRANK AND CRANK SHAFT

Crank is rotating part of an internal combustion engine. It

is mounted on crank shaft. It converts reciprocating

motion of piston in rotating motion. When piston comes

from TOP DEAD CENTRE to BOTTAM DEAD CENTRE crank

rotates 180⁰. Mechanism of crank and crank shaft is

fitted in crank case. Crank case is air tight because fresh

charge has to enter into crank case.

Mechanism of crank and piston

Crank

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CYLINDER

Cylinder is the heart of the engine in which the fuel is

burnt and the power is developed. Cylinder has to

withstand very high pressure and temperature because

the combustion of fuel is carried out within the cylinder.

Therefore cylinder must be cooled. Cylinder of this

engine is air cooled. Cylinder of this engine consists of

transfer port which transfers fresh charge from crank

case to combustion chamber. Volume for cylinder of this

engine is 145.45 cm³.

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CYLINDER HEAD

Cylinder head is fitted at top of

cylinder. Cylinder head is providing

space for spark plug and other

accessories. The inner surface of

cylinder head of this engine is in

completely fitting with top surface

of piston. There is one

hemispherical pit for clearance volume purpose.

SPARK PLUG

Spark plug is important device for

CNG and petrol engine. When

pressure and temperature of fuel

after compression is and this time

spark is produce and combustion of

fuel take place. Power is produce at

this time. Magnetic induction spark

plug is used in this engine. So, there is no requirement of

battery for running engine.

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FLYWHEEL

It is a heavy wheel mounted on the crank shaft of engine.

It is minimize cycle variation of speed by storing the

energy during power stroke, and same is released during

another stroke. Flywheel of this engine is also consist

powerful magnet for produce electrical energy. This

energy is utilized by spark plug and other works like

charging of battery, drive wiper motor, lighting purpose.

MECHNISM FOR SET DELAY IN SPARK PLUG

There is on strip around

flywheel which is in contact

with censor when this strip is

come in contact with censor

spark occurs.

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CLUTCH

Multidisc type clutch is used in power transmission

system of this engine. One clutch wire is connected with

operating lever of this clutch. When clutch operating

lever is pressed disc of clutch is disengages from each

other and transmission of power is stop.

GEARBOX

In gearbox of this engine there

are four spur gears. All gears are

gradually decreases in size.

Largest gear give high amount of

torque and small gear give high amount of speed. There

is one spring in side of gears which is connecting kick.