The working environment of cylinder liner is very bad, and there are many reasons for wear. Normally wear is allowed due to structural reasons, but improper use and maintenance will result in abnormal wear.
01 wear caused by structural reasons
The lubrication condition is bad, so that the upper part of cylinder liner is worn seriously. The upper part of the cylinder liner is adjacent to the combustion chamber. The temperature is very high and the lubrication condition is very poor. The erosion and dilution of fresh air and non evaporating fuel intensifies the deterioration of upper conditions, causing dry friction or semi dry friction on the cylinder, which is the cause of the serious wear on the upper part of the cylinder.
The upper part bears great pressure and makes the cylinder wear up and down. In the spring and back pressure under the action of pressure in the cylinder wall tight piston ring is more pressure, oil film formation and maintenance more difficult, mechanical wear.
Mineral acid and organic acid make the cylinder surface corrode and peel off. The combustible mixture in cylinder combustion, produce water vapor and acid oxide dissolved in water, they generate mineral acids, have a corrosive effect on the cylinder surface, corrosion gradually by the piston ring scrape in friction, resulting in deformation of the cylinder sets.
Enter the mechanical impurities, so that the central part of the cylinder wear intensifies. The dust in the air, the impurity in the lubricating oil, into the piston and cylinder wall caused by abrasive wear. When the dust or impurity moves back and forth with the piston in the cylinder, because of the maximum velocity in the middle part of the cylinder, the wear of the middle part of the cylinder is aggravated.
02 wear caused by improper use
Oil filter filtration effect is poor. If the lubricating oil filter is not working properly, the lubricating oil can not be effectively filtered, and the lubricating oil containing a large number of hard particles will inevitably aggravate the abrasion of the cylinder liner.
The air filter filtration efficiency is low. The function of the air filter is to remove dust and sand from the air entering the cylinder, so as to reduce the wear of the parts such as the cylinder, piston and piston ring.
Long time low temperature operation. Long time low temperature operation, one is caused by poor combustion, carbon deposition from the upper part of the cylinder liner spread, so that the upper part of the cylinder liner produces serious abrasive wear; two is caused by electrochemical corrosion.
Often use inferior lubricating oil. Some owners for easy save money, often in the roadside shop or to illegal oil vendors buy inferior lubricating oil use, resulting in strong corrosion on the top of the cylinder sleeve, its wear than the normal value of 1-2 times.
03 wear caused by improper maintenance
Improper installation of cylinder sleeve. When installing the cylinder liner, if there is installation error, the center line of the cylinder and the crankshaft axis are not vertical, it will cause abnormal wear of the cylinder liner.
Copper sleeve hole deflection of connecting rod. In the process of repair, reaming connecting rod copper sleeve, reamer tilt caused by deflection of connecting rod copper sleeve hole, a piston pin connecting rod center line and the center line is not parallel, forcing the piston to the cylinder liner a side tilt, can also cause abnormal wear cylinder liner.
Bending deformation of connecting rod. Because of the car accident or other reasons, the connecting rod of the impact will produce bending deformation, if not corrected in time and continue to use, it will accelerate the wear of the cylinder liner.
The crankshaft connecting rod journal and spindle neck are not parallel. Because of engine burning tile and other reasons, the crankshaft will be distorted due to severe impact, if not corrected in time and continue to use, the same will accelerate the cylinder liner wear.
Measures for reducing wear of cylinder liner
01 start and start correctly
When the engine cold starting, because of low temperature, big oil viscosity, poor mobility, the oil supply of the oil pump is insufficient. At the same time, the original wall of oil in the parking along the cylinder walls dirty, so in the starting moment of lubrication is not the normal work as well, resulting in the starting cylinder wear increase greatly. Therefore, when the initial start, the engine should be idling several laps, after the friction surface lubrication, restart. After starting the heating should be idle, no Meng oil outlet, start again until the oil temperature reached 40 degrees; the start should adhere to hang low gear and sequential each gear driving a mileage, until the temperature is normal, can be turned into normal running.
02 correct selection of lubricating oil
It is necessary to select the best viscosity value according to the season and the engine performance requirements. The inferior lubricating oil can not be purchased at will, and the quantity and quality of the lubricating oil are often checked and maintained.
03 strengthen the maintenance of filter
Keeping the air filter, oil filter and fuel filter in good working condition is very important to reduce the wear of the cylinder liner. Strengthen the "three" maintenance, is to prevent the mechanical impurities into the cylinder, reduce cylinder wear, prolong the service life of the engine is one of the important measures, is particularly important in rural and wind areas. It's absolutely wrong for some drivers to save fuel without air filters.
04 maintain engine normal operating temperature
The normal working temperature of the engine should be kept at 80-90 degrees while maintaining the normal working temperature of the engine. The temperature is too low, can't keep good lubrication, will increase the wear of the cylinder wall, cylinder water vapor condenses into water, acidic gas molecules dissolved in waste gas, formation of acidic substances, so that the cylinder subjected to corrosive wear. The test results show that when the cylinder wall temperature is decreased from 90 to 50, the wear rate of the cylinder is 4 times as much as 90 degrees centigrade. If the temperature is too high, the cylinder strength will decrease and the wear will be aggravated, and even the piston will expand excessively, which will result in "bulge" accident.
05 improve the quality of warranty
In the process of using, timely find out the problems, timely remove, replace or repair damaged and deformed parts at any time. Installation of the cylinder liner should be strictly according to the technical requirements for inspection and assembly. In the maintenance ring changing operation, the piston ring with proper elasticity should be used, and the elastic force is too small to make the gas
