The piston top is a component of the combustion chamber, and is often made into different shapes. Gasoline engines often use a flat or concave top to make the combustion chamber structure compact, with a small heat dissipation area, and a simple manufacturing process. The convex piston is commonly used in two-stroke gasoline engines. The piston crown of diesel engines is often made into various pits.

The piston head is the part above the piston pin seat. The piston head is equipped with a piston ring to prevent high-temperature and high-pressure gas from entering the crankcase and oil from entering the combustion chamber; Most of the heat absorbed by the top of the piston is also transmitted to the cylinder through the piston head, and then through the cooling medium.

Technical Requirements Editing Broadcast

1. It should have sufficient strength, stiffness, small mass, and light weight to ensure the minimum inertial force.

2. Good thermal conductivity, high temperature resistance, high pressure, corrosion resistance, sufficient heat dissipation ability, and small heating area.

3. There should be a small coefficient of friction between the piston and the piston wall.

4. When the temperature changes, the size and shape changes should be small, and the minimum gap between them and the cylinder wall should be maintained.

5. Small coefficient of thermal expansion, small specific gravity, good antiwear property and thermal strength. [2]