What is Piston in IC engine?
The piston is one of the engine main components that help to convert pressure energy into mechanical work.
The Piston reciprocates inside of the cylinder to continuously change the volume enclosed by the cylinder and piston that is required for various functions as given below:-
- For suction stroke, the piston increases the volume by moving from TDC to BDC.
- For compression stroke, the piston decreases the volume by moving from BDC to TDC.
- For power stroke, the piston increases the volume by moving from TDC to BDC.
- For exhaust stroke, the piston decreases the volume by moving from BDC to TDC.
The Piston also helps to seal the space enclosed by a cylinder and Piston by means of piston rings. In some engines, the piston also helps for the cooling of the engine by means of circulating engine oil inside of the piston.
Function of piston in IC engine:
Following are some of the major functions of the piston that are useful in engine operation.
1] Convert pressure energy into useful work: It is the major function performed by the piston in the IC engine. The Piston helps to convert high-pressure energy that results due to the combustion into useful work.
2] Compress the air-fuel mixture: The Piston helps to compress the air-fuel mixture taken into the cylinder by the use of energy stored in the flywheel.
3] Creates negative pressure for suction: During the suction stroke, the Piston moves from TDC to BDC which results in creating negative pressure inside the cylinder. This negative pressure helps to suck the air-fuel mixture inside the cylinder.
4] Helps to expel out exhaust gas: During the exhaust stroke when the exhaust valves are open, the Piston moves from BDC to TDC to remove exhaust gases from the cylinder.
5] Sealing of the combustion chamber: The Piston rings help to seal the enclosure formed by the Piston and cylinder. therefore the gases inside the combustion chamber are unable to leak from the gap between piston and cylinder.