Cylinder liner working environment is very bad, there are many causes of the wear and tear. Usually due to structure allows for normal wear and tear, but use and maintenance is undeserved, can cause abnormal wear and tear. 1 structural causes of wear and tear
1), and the bad lubrication condition to make the upper cylinder liner wear is serious. Cylinder liner upside adjacent chamber, high temperature, lubrication condition is very poor. Fresh air and evaporation of fuel dilution and scouring, exacerbated by the upper conditions worse, make on the cylinder is in dry friction or half dry friction condition, this is the cause of the upper cylinder wear.
2) the upper pressure big, make the cylinder wear with under the heavy weight. Piston ring in its tension and compression under the influence of the back pressure in the cylinder wall, the positive pressure, the greater the lubricating film formation and keep the more difficult, mechanical wear. In the work schedule, with the piston downward, the positive pressure to reduce gradually, and cylinder wear presented under the heavy weight.
3) mineral acids and organic acids make cylinder surface spalling corrosion. Combustible mixture in the cylinder after combustion, produce the water vapour and acidic oxides, they generate mineral acid soluble in water, and generated in the combustion of organic acid, a corrosive effect on the surface of a cylinder, corrosion, piston ring in friction gradually be scraped off, cause deformation of cylinder liner.
4) into the mechanical impurities, and the central cylinder wear. The dust in the air, the impurity in the lubricating oil and so on, into the abrasive wear between piston and cylinder wall. Dust or impurities with the piston in the cylinder reciprocating motion, because the speed of movement of the largest in the central cylinder position, therefore, intensified in central cylinder wear.
2 use undeserved cause wear and tear
1) the lubricating oil filter filtration effect is poor. If the operation of the lubricating oil filter oil can not get effective filtering, contains a lot of hard particles in lubricating oil must make wall inside the cylinder liner wear.
2) air filter filtration efficiency is low. The effect of air filter is to clear the air into the cylinder in the dust and sand, in order to reduce the wear of cylinder, piston and piston ring parts. Experimental results show that the engine without air filter, air cylinder wear will be increased by 6-8 times. Air filter for a long time without cleaning and maintenance, poor filtration effect, will speed up the cylinder liner wear.
3) temperature operation for a long time. Temperature operation over a long period of time, it is caused by poor combustion, carbon deposition started from the upper cylinder and the cylinder liner top produce serious abrasive wear; Second, the electrochemical corrosion.
4) often use inferior oil. Some owners to short-cut to save money, often at the booth or illegal oil to buy inferior oil use, resulting in strong corrosion of the upper cylinder liner, its wear is 1 to 2 times larger than normal.
3 the wear and tear of improper maintenance
1) cylinder liner improper installation location. Installation error when installing a cylinder liner, if present, the center line of the cylinder and crankshaft axis is not perpendicular, will cause abnormal wear cylinder.
2) connecting rod copper set of hole deviation. In repair, the ream connecting rod small copper sleeve, reamer tilt caused by copper connecting rod set of hole deviation, and the center line of the piston pin do not parallel with the center line of the connecting rod little head, forcing the piston tilt to one side of the cylinder liner, can also cause abnormal wear cylinder.
3) the connecting rod bending deformation. Due to accident or other reasons, the impact of the connecting rod will produce bending deformation, if not timely correction and continue to use, also can accelerate the cylinder liner wear.