1. Compression: The primary function of the piston is to compress the air-fuel mixture in the cylinder. As the piston moves upward during the compression stroke, it reduces the volume of the combustion chamber, increasing the pressure and temperature of the air-fuel mixture. This high pressure and temperature are essential for initiating the combustion process.
2. Power Generation: During the power stroke, the ignited air-fuel mixture rapidly expands and generates high pressure within the cylinder. This pressure forces the piston downward, transmitting the force to the crankshaft through the connecting rod. The reciprocating motion of the piston converts the linear motion into rotational motion, which is then transmitted to the rest of the driveline.
3. Sealing the Combustion Chamber: The piston and the cylinder walls form a seal that prevents the compressed air-fuel mixture from leaking out during the compression and power strokes. The piston rings, located in grooves on the piston, are responsible for maintaining this seal.
4. Heat Transfer: The piston also plays a vital role in heat transfer. During combustion, a significant amount of heat is generated, which can cause damage to engine components. The piston helps dissipate this heat by transferring it to the cylinder walls and the cooling system.
5. Lubrication: The piston relies on a thin film of oil for lubrication to reduce friction and wear between the piston and the cylinder walls. It helps to ensure smooth movement of the piston and extends the engine's life.
Overall, the piston's functions in a diesel engine are crucial for efficient and reliable operation. It is a critical part of the engine's combustion process, power generation, and overall performance.
