Engine pull cylinder, refers to the cylinder wall in the piston ring within the scope of movement of the apparent longitudinal mechanical scratches and scratches, serious occurrence of melt wear, causing the engine to start difficult or self-flame failure.
The root cause of the cylinder is the cylinder wall and the piston ring, between the piston is difficult to form oil film, resulting in poor lubrication, or even dry friction phenomenon. The specific cause of this situation comes down to roughly three aspects:
Piston group reasons
01 Piston ring clearance is too small
If the piston ring clearance is too small, resulting in the engine piston ring heat expansion stuck, and the cylinder wall pressure is tight, or the piston ring broken, it is easy to pull out the groove in the cylinder wall.
02 Piston pin sprang
As the piston pin spring is not installed or off, broken, the piston pin sprang in the movement, it is easy to pull the cylinder wall, causing the cylinder channeling to the crankcase.
03 Piston with cylinder clearance is too small or too large
Piston material, size, etc. there is a large error or deformation in the assembly, resulting in the cylinder with the cylinder clearance is too small or too large, the piston will be stuck after thermal expansion, and then pull the cylinder wall.
04 The piston ring is heavily coke
Excessive coke caused by the piston ring bonding or bite in the ring groove, while carbon deposition is a hard abrasive, will be in the cylinder wall grinding into a longitudinal groove. The following are the same as the ”
05 Piston serious partial cylinder
Pistons clearly partial cylinder, will accelerate the piston ring, piston and cylinder wall wear, destruction of the formation of oil film.
Cylinder liner reasons
01 Cylinder liner roundness, cylindrical tolerance beyond the allowable range.
So that the piston and cylinder liner greatly reduced the seal, the cylinder of high temperature gas channeling, damage between the piston and the cylinder wall between the oil film, and then cause the cylinder.
02 The cylinder liner is deformed during assembly.
For example: the upper end of the cylinder liner protruding amount is too large, the cylinder head after the cylinder pressure deformation, etc., are likely to cause the cylinder.
01 The air cleaner is not sealed
So that the filter effect worse, the air of dust, sand and other impurities inhaled into the cylinder, the formation of abrasive wear.
02 Running bad
New machine or overhaul after the engine, in the cylinder liner, piston and piston rings and other parts of the surface there are many micro-uneven, lubricating oil film is difficult to form.
03 Often low temperature start
Engine low temperature start, the oil viscosity, poor mobility, in the cylinder wall is difficult to form an effective oil film.
04 The engine is overheated
Excessive machine temperature not only reduces the mechanical strength of the part, but also makes the oil film inside the cylinder can not be formed. Pistons and other parts of the thermal expansion, easy to stuck in the cylinder, the consequences are often pulled inside the cylinder liner was pulled, forcing the engine flameout.
In actual use, the cylinder is often the result of several factors together.
For example, without running the engine cold start immediately after the start into full operation, this time it is prone to pull cylinder accident.
The main measures to prevent the cylinder
1. The new engine and overhaul after the engine, in maintaining good lubrication conditions, in accordance with the speed from low to high, the load from small to large principle, carefully according to the run-in procedures, and then to put the official load operation.
2. Correctly match the gap between the piston skirt and the cylinder liner, the opening clearance of the piston ring and the side clearance. In addition, the repair should also live on the piston cylinder off, while the size of the cylinder liner to ensure the accuracy.
3. Maintain the normal temperature of the cooling water 70 ℃ ~ 95 ℃, to avoid the engine overheating. Preheat measures should be taken before starting in winter.
4. Reasonable operation using the engine, do not overload operation, do not indiscriminate throttle, do not miss the coolant start.
5. Strengthen the air filter maintenance, prevent dust inhalation cylinder.
6. Maintain a good lubrication system to prevent the mechanical impurities and carbon deposition into the oil and increase the wear of the cylinder liner.