Transcript
CarburetorCarburetor
OutlinesOutlines
Carburetor Carburetor
Working principle of carburetorWorking principle of carburetor
Function and uses of ChokeFunction and uses of Choke
OverflowOverflow
AcceleratorAccelerator
The function of a The function of a carburetor in a vehicle is carburetor in a vehicle is similar to that of a human similar to that of a human
Heart.Heart.
CarburetorCarburetor
To maintain a small reserve of petrol To maintain a small reserve of petrol at constant headat constant head
To vaporize the petrol by means of To vaporize the petrol by means of engine suction and to produce engine suction and to produce homogenous air fuel mixture homogenous air fuel mixture
To supply the required air & petrol at To supply the required air & petrol at the correct mixture strength the correct mixture strength
Fuel
Air
Carburetor
Engine Cylinde
r
Throttle Valve
Inlet Exhaust
Block diagram of Carburetor
Working principle of Working principle of carburetorcarburetor
ChokeChoke
FunctionFunction
To supply very rich To supply very rich mixture so that the mixture so that the ratio of the air to ratio of the air to vaporized fuel in the vaporized fuel in the cylinder is within the cylinder is within the combustible limitcombustible limit
UsesUses
During winter During winter season, it season, it supplies extra supplies extra fuelfuel
Air-fuel mixtureAir-fuel mixture
Too rich to burn
Combustible range Too lean to burn
9:1 19:115:1
Excess Fuel Excess Air
• Chemically correct mixtureChemically correct mixture• Rich mixtureRich mixture• Lean mixtureLean mixture
OverflowOverflow
When the mixture of air and fuel When the mixture of air and fuel becomes more richer than the becomes more richer than the ratio 9:1 then the condition of ratio 9:1 then the condition of OverflowOverflow occurs. occurs.
Reasons of overflowReasons of overflow
When the choke valve remains closed When the choke valve remains closed for a long time. for a long time.
When the float valve needle does not When the float valve needle does not close the intake of petrol in the float close the intake of petrol in the float chamber and the petrol overflows.chamber and the petrol overflows.
When the vehicle remains tilted to When the vehicle remains tilted to one side for a long period.one side for a long period.
How vehicle can be started How vehicle can be started after overflowafter overflow
Open the spark plug , clean it Open the spark plug , clean it and apply kick several times and apply kick several times so that the overflowed petrol so that the overflowed petrol may be expelled out from the may be expelled out from the engine cylinder.engine cylinder.Put the petrol knob at the Put the petrol knob at the Closed condition, open the Closed condition, open the accelerator to its maximum accelerator to its maximum and apply kicks continuously.and apply kicks continuously.
How accelerator worksHow accelerator works
On applying the accelerator, it opens the On applying the accelerator, it opens the throttle valve and the air-fuel mixture starts throttle valve and the air-fuel mixture starts entering into the engine cylinder in the entering into the engine cylinder in the increased amount continuously so that the increased amount continuously so that the engine gets more power to produce its engine gets more power to produce its power strokes and the output of the engine power strokes and the output of the engine increased and hence the speed of the increased and hence the speed of the vehicle. vehicle.
Thank youThank you