Petrol Bbk

PRESENTED BY: STUDENT TRAINER : Mrs RUPALI CLASS : 9TH GROUP LEADER : SUCHLEEN STUDENTS: INDERJEET, NEELAM, KUSUM GOVT. HIGH SCHOOL, BASTI BAWA KHEL,JALANDHAR

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INTRODUCTION PRINCIPLE CONSTRUCTION WORKING RESULT ACKNOWLEDGMENT

INTRODUCTION 

PETROL ENGINE WORKS ON THE PRINCIPLE OF INTERNAL COMBUSTION ENGINE.IN THIS TYPE OF ENGINE,THE COMBUSTION OF FUEL TAKES PLACE INSIDE THE CYLINDER OF THE ENGINE.FOR EXAMPLE:PETRO ENGINE, DIESEL ENGINE.

PRINCIPLE 

In the petrol engine,the fuel is vaporised and mixed with the correct amount of air in the carburater. This mixture of petrol vapours and air is passed into the cylinder fitted with a movable piston.It is then compressed and ignited by an electric sparke from a spark plug. The petrol and air mixture burns rapidly to produce a large volume of hot gases in of the cylinder and therefore high pressure is build up inside the cylinder.

CONSTRUCTION 

A simple internal combustion engine consists of a metal cylinder c fitted with an air tight movable piston,p.There are two holes in the cylinder head which are controlled by two valves v1 &v2. The valve v1 is called intake valve and the fuel mixture of petrol and airenters into the cylinder through this valve.

WORKING 

2. 3. 4. 5.

WORKING IS DIVIDED INTO FOUR STAGES CALLED FOUR STROKES OF THE ENGINE. INTAKE STROKE COMPRESSION STROKE POWER STROKE OR EXPANSION STROKE EXHAUST STROKE

1.INTAKE STROKE 

IN THIS STEP, THE FUEL AIR MIXTURE ENTERS INTO THE CYLINDER. WHEN THE ENGINE STARTS, THE PISTON , P MOVES DOWNWARDS IN THE CYLINDER. AS A RESULT, A REGION OF LOW PRESSURE IS CREATED IN THE CYLINDER ABOVE THE PISTON.THIS STEP IS ALSO CALLED CHARGING STROKE.

DIAGRAM

2.THE COMPRESSION STROKE 

IN THIS STEP, THE FUEL AIR MIXTURE IS HIGHLY COMPRESSED TO SMALL VOLUME.WHEN THE SUFFICIENT AMOUNT OF THE FUEL AIR MIXTURE HAS ENTERED THE CYLINDER, THE INTAKE VALVE GETS CLOSED. THE PISTON IS THEN FORCED TO MOVE UPWARDS WHICH COMPRESSES THE FUEL AIR MIXTURE TO ABOUT 1/8TH OF THE ORIGINAL VOLUME.

3.POWER STROKE OR EXPANSION STROKE 

IN THIS STEP, THE COMPRESSED FUEL –AIR MIXTURE IS IGNITED BY A SPARK FROM THE SPARK PLUG. AS A RESULT ,A LARGE VOLUME OF GASES AND HEAT IS PRODUCED.THE HEAT THUS PRODUCED EXPANDS THE GASES RAPIDLY AND PUSHES THE PISTON DOWNWARDS.THIS STROKE PROVIDES POWER SO CALLED POWER STROKE.

4.EXHAUST STROKE 

IN THIS STEP, THE BURNT GASES ARE EXPELLED OUT OF THE CYLINDER .WHEN THE PISTON HAS MOVED DOWNWARDS BY THE HOT EXPANDING GASES IN THE POWER STROKE, THE EXHAUST VALVE OPENS .DUE TO MOMENTUM GAINED BY THE WHEELS ,THE PISTON MOVES UPWARD AND EXPELS THE BURNT GASES THROUGH THE V2.

RESULT 

THE ENTIRE CYCLE IS COMPLETED IN FOUR STROKE AND RESULTS INTO TWO CRANKSHAFT REVOLUTIONS.THE ENGINED DURING DIFFERENT STROKES ARE SHOWN BY VARIOUS STAGES.

ACKNOWLEDGMENT 

WE ARE THANKFUL TO OUR STUDENT TRAINER MRS RUPALI WHO HELP US IN COMPLETING THIS PROJECT. WE ARE ALSO THANKFUL TO DE-PROGRAM WHO HELPS TO INCREASES OUR KNOWLEDGE. THANKS