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Engine.ppt - 1 of 20

Product Dissection 04/07/98 GIVEN BY A.RAHUL T.SUNIL MECH(VIGNAN)GUNTUR

DIFFERENT TYPES OF ENGINES


Product Dissection 04/07/98

Engine Dissection

You are dissecting a 3.5 HP single cylinder, 4 cycle engine, made by Briggs and Stratton in Milwaukee, Wisconsin

These engines are typically used in lawn mowers, snow blowers, go-carts, etc



Engine Module Contents

References History Engine Classifications Complementary Technologies Engine Operation Principles Fuel Delivery (carburetors and fuel injection) Ignition Systems Manufacture and Materials Issues (under construction)



References

1) “Why Internal Combustion ?”, Rudi Volti, Invention and Technology, Fall 1990, pp 42-47

2) Briggs and Stratton Service and Repair Instructions for single cylinder 4-cycle engines, 1992

3) Internal Combustion Engines and Air Pollution, Edward Obert, Intext Education Publishers, New York, 1973

4) Introduction to Internal Combustion Engines, Richard Stone, Macmillan, 1985.



Classification of Engines

External vs Internal Combustion Spark Ignition SI or Compression Ignition CI Configuration Valve Location 2 Stroke or 4 Stroke



Engine Configurations

Radial (Aircraft)

V(Automobile)

In Line(Automobile)

Horizontally Opposed (Subaru)

Opposed Piston (crankshafts geared

together)



Valve Location

L Head(Briggs)

I Head(typical automobile engine)



History of IC Engines

1860 Lenoir’s engine (a converted steam engine) combusted natural gas in a double acting piston, using electric ignition



History

1876 Nikolaus Otto patented the 4 cycle engine, it used gaseous fuel

1882 Gottlieb Daimler, an engineer for Daimler, left to work on his own engine. His 1889 twin cylinder V was the first engine to be produced in quantities. Used liquid fuel and Venturi type carburetor, engine was named “Mercedes” after the daughter of his major distributor

1893 Rudolf Diesel built successful CI engine which was 26% efficient (double the efficiency of any other engine of its time)



Complementary Technologies for IC Engine-powered Automobiles

Pneumatic tires (1888, Dunlop) Cheap liquid fuels (Oil industry born in PA 1859) Venturi effect carburetor (1892, Willi Maybach) Variable mechanical transmission (primitive type by

Levassor, 1891) Electric starter (Kettering 1912)



Parts of an IC Engine

Air cleaner

Choke

Throttle

Intake manifold

Exhaust manifold

Piston ringsPiston

Wrist pinCylinder blockConnecting rod

Oil gallery to pistonOil gallery to head

Crankcase

Crankpin

Crankshaft

Cylinder head

Breather cap

Rocker armValve spring

Valve guidePushrod

Sparkplug

Combustion chamber

Tappet

Dipstick

Cam

Camshaft

Water jacket

Wet liner

Connecting rod bearing

Main bearing

Oil pan or sump



4 Cycle Process

Intake StrokeIntake valve opens,

admitting fuel and air.Exhaust valve closed

for most of stroke

Compression StrokeBoth valves closed,Fuel/air mixture is

compressed by rising piston. Spark ignitesmixture near end of

stroke.

IntakeManifold

Spark PlugCylinder

Piston

Connecting Rod Crank

Power StrokeFuel-air mixture burns,increasing temperature

and pressure, expansionof combustion gases

drives piston down. Bothvalves closed - exhaust valve opens near end

of stroke

1 2 3 4

Exhaust StrokeExhaust valve open,exhaust products are

displaced from cylinder.Intake valve opens near end of stroke.

Crankcase

ExhaustManifold

Exhaust ValveIntake Valve



Intake



Compression



Power Stroke



Exhaust Stroke



2 Stroke Process

Compression(ports closed)Air Taken Into

Crankcase

Combustion(ports closed)

Exhaust(intake port closed)

Air compressed in crankcase

Scavengingand Intake

(ports open)



Rotary “Wankel” Engine



Venturi-type Carburetor

P+1/2 V2 = Constant

Bernoulli Effect:

Constant level is maintained in bowl -as float moves down, valve stem moves down, allowing more fuel into bowl, float moves up and closes valve

Valve StemFuel Inlet

Float

Metering Orifice

Throttle Plate

Air/Fuel Mixture To Engine

Choke Plate

Fuel Nozzle

Inlet Air

Bowl

Atomized Fuel

Venturi



Fuel Injection (electronic, multi-port)

50 psi typical

Monitored Engine Operating Conditions:

Manifold PressureEngine Speed

Air TemperatureCoolant Temperature

Acceleration

COMPUTERTRIGGER

INJECTOR DRIVE UNIT

Pressure Regulator FuelFilter

Fuel Pump

FUEL TANK

Injectors



ANY QURIES??????????????

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