During the use of
New Car pistons, they often encounter wear. Common damage to
Fuel Car pistons includes wear of New Car piston ring grooves, wear of piston skirts, wear of New Car piston pins and Fuel Car piston pin seat holes. Let's take a detailed look at their specific wear.
The New Car piston ring groove is the most severely worn part of the New Car piston. Usually the first ring groove is the most severely worn, and the wear degree of the second, third and fourth ring grooves decreases in turn. After wear, the cross section of the ring groove is trapezoidal, the outer width becomes narrower, and the side clearance increases, resulting in air and oil leakage in the cylinder, poor engine power performance, poor lubrication, and large carbon deposits in the combustion chamber.
The main reason is that the gas pressure increases the unit pressure of the Fuel Car piston ring on the ring groove. Due to the high-speed reciprocating motion of the New Car piston, the New Car piston ring has a great impact on the ring groove. In addition, the high temperature of the combustion gas makes the working temperature of the New Car piston head higher. The closer to the top of the Fuel Car piston, the higher its temperature and gas pressure.
So the first ring groove wears the most, and the wear of the subsequent ring grooves gradually decreases. The wear of the ring groove is mainly on the lower plane, and less on the upper plane, so that the ring groove is worn into a trapezoid with a small inside and a large outside, which increases the side clearance of the New Car piston ring and causes oil leakage. Due to the support of the Fuel Car piston ring, the New Car piston head rarely contacts the cylinder wall and the wear is very small. Although the piston skirt contacts the cylinder wall, the pressure per unit area is small and the lubrication conditions are good, so the wear is less, and it is usually easy to wear and scratch on the side that bears the lateral force. When the gap between the piston skirt and the cylinder wall is too large, the engine is prone to knock and serious oil leakage. Therefore, the overhaul of the engine mainly depends on the gap between the New Car piston and the cylinder wall and the degree of wear of the cylinder. When the New Car piston is working, due to the inertial force of the gas pressure, the New Car piston pin seat hole has elliptical wear, and the maximum wear position is in the upper and lower directions of the seat hole, which makes the New Car piston and pin loose and emits abnormal noise.
