What is the reason why the automobile accelerator clamp spring falls off?

The reason is: 1 The tolerance of cylinder liner roundness and cylindricity exceeds the allowable range: the sealing between piston and cylinder liner is greatly reduced, and the high-temperature gas in the cylinder runs down, destroying the oil film between piston and cylinder wall, and then causing cylinder pulling.

2. The cylinder liner is deformed during assembly: for example, the upper end face of the cylinder liner protrudes too much, and the cylinder liner is compressed after the cylinder head is installed; The water stop ring of cylinder liner is too thick, which will deform the cylinder liner after being pressed into the engine block, and it is easy to cause cylinder pulling.

The reason for the piston group.

1. Piston ring clearance is too small: if the opening clearance, side clearance or back clearance of the piston ring is too small, the piston ring will be stuck due to thermal expansion when the engine is working, or tightly pressed against the cylinder wall, or the piston ring will collapse, so it is easy to pull grooves on the cylinder wall.

2. Piston pin comes out: because the piston pin circlip is not installed or falls off and breaks, the piston pin comes out during the movement, which is easy to strain the inner wall of the cylinder and cause the cylinder to come out to the axle box.

3. The gap between the piston and the cylinder is too large or too small: if the piston is made of poor material, the manufacturing dimension error is too large, or the piston is deformed after assembling the piston pin, it is agreed that the gap between the piston and the cylinder is too small, and the piston is stuck after being heated and expanded, and then the cylinder wall is pulled.

4. Serious carbon deposition on the piston ring: too much carbon deposition causes the piston ring to get stuck in the bad groove. At the same time, carbon deposit is a hard abrasive, which will grind longitudinal grooves on the cylinder wall.

5. Serious eccentricity of the piston: due to the bending and torsion deformation of the connecting rod, the shaft stiffness of the connecting rod and the large deviation of the parallelism and coaxiality of the piston pin seat, the piston is obviously eccentric, which will accelerate the wear of the piston ring, piston and cylinder wall and destroy the formation of oil film.