The engine cylinder sleeve and the piston ring are a pair of friction pairs in the case of high temperature, high pressure, alternating load and corrosion. Long term in the complex and changeable situation, the result is caused by the cylinder liner wear deformation, which affects the engine power, economy and service life. It is very important to analyze the reason of the cylinder liner wear deformation and to improve the economic performance of the engine.
One, the reason of the cylinder liner wear analysis of the working environment of the cylinder liner is very bad, there are many reasons for the wear and tear. Usually due to structural reasons allow normal wear and tear, but improper use and maintenance, it will cause non normal wear and tear.
1, structural causes of wear
1) lubrication condition is not good, make the cylinder liner wear serious. The upper part of the cylinder jacket is adjacent to the combustion chamber, the temperature is very high, and the lubrication condition is very poor. The fresh air and fuel evaporation of scour and dilution, worsen the condition of the bad, the cylinder is in the dry or semi dry friction state, which is caused by Baotou North Benz parts of the upper part of the cylinder wear serious reason.
2) the upper bearing pressure, so that the cylinder wear and tear on the weight of light. 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. In the process of work, with the piston down, the pressure is gradually reduced, and thus the cylinder wear is heavy and light.
3) mineral acids and organic acids to cause corrosion and spalling of the surface of the cylinder. The combustible mixture in cylinder combustion, produce water vapor and acid oxide dissolved in water, they generate mineral acid, organic acid generated in combustion and the corrosive effect on the cylinder surface, corrosion gradually by the piston ring scrape in friction, resulting in deformation of the cylinder sets.
4) into the mechanical impurities, so that the central cylinder wear. The dust in the air, the impurity in the lubricating oil, into the piston and cylinder wall caused by abrasive wear. The dust or impurities in the piston in the cylinder reciprocating motion, due to the central position in the central position of the largest movement, it is exacerbated by the middle of the cylinder wear.
2, improper use of wear
1) oil filter filtration effect is poor. If the oil filter does not work properly, the lubricating oil are not effectively filter, lubricating oil contains a lot of hard particle will make the cylinder wear is intensified.2) Baotou Benz parts air filter filtration efficiency is low. The air filter is to remove the dust and sand from the air entering the cylinder to reduce the wear of the cylinder, piston and piston rings. Experiments show that if the engine does not contain air filter, the wear of the cylinder will increase 6-8 times. The air cleaner is not a long-term cleaning and maintenance, cleaning effect is poor, the cylinder liner wear will accelerate.
3) long time low temperature operation. Long period of low temperature operation, one is caused by poor combustion, carbon accumulation from the upper part of the cylinder jacket began to spread, so that the upper part of the cylinder liner to produce serious abrasive wear; two is caused by electrochemical corrosion.
4) often use inferior lubricating oil. Some owners to save money, often at the roadside shop to buy or sell illegal oil inferior oil, resulting in strong corrosion of the upper cylinder, the wear volume is 1-2 times larger than the normal value.
3, improper maintenance caused by wear and tear
1), the installation position of the cylinder liner is improper. When installing the cylinder liner, if there is an error, the cylinder center line and the crankshaft axis is not perpendicular, will cause the cylinder liner is not normal wear and tear.
2), connecting rod copper sleeve hole deviation. In the process of repair, reaming connecting rod copper sleeve, reamer tilt caused by deflection of connecting rod copper sleeve hole, piston ring with the center line of the connecting rod center line is not parallel, forcing the piston to the cylinder liner a side tilt, can also cause abnormal wear cylinder liner. 3) bending deformation of connecting rod. Because of the car accident or other reasons, the impact of the connecting rod will produce bending deformation, if not timely correction and continue to use, will accelerate the wear of the cylinder liner.
3, Baotou in the north of the crankshaft connecting rod journal and the main axis of the neck is not parallel. Because of burning tile and other reasons, the crankshaft will be deformed due to severe impact, if not timely correction and continue to use, the same will accelerate the cylinder liner wear. Two, the measures to reduce the cylinder liner wear 1 correct start and start the engine cold start, due to the low temperature, oil viscosity, poor mobility, so that the shortage of oil pump. 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, the initial start, should first make the engine idling a few laps to get lubrication friction surface after starting. 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.
4, the correct choice of lubricating oil to be strictly according to season and engine performance requirements of the best choice of the value of the viscosity of the lubricant, can not be purchased with poor quality lubricating oil, and often check and maintain the quantity and quality of lubricating oil.
5), strengthen the maintenance of the filter so that the air filter, oil filter and fuel filter to maintain a good working state, to reduce the wear of the cylinder liner is essential. 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. In order to save fuel, some drivers don’t install the air filter.
6), maintain the normal operating temperature of engine operating temperature should be at 80-90. 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. Experiments show that when the cylinder temperature from 90 degrees to 50 degrees, cylinder wear for 4 times at 90. The temperature is too high, the strength of the cylinder will be reduced and increased wear and tear, and even may cause excessive expansion of the piston caused by “cylinder” accident.
7), to improve the quality of warranty in the use of the process, timely detection of problems in a timely manner to be excluded, at any time to replace or repair damage and deformation of the parts. Installation of cylinder liner to be strictly according to the technical requirements of inspection and assembly. In guarantee for ring assignments, to choose the proper elasticity piston ring, tension is too small, so that the gas into the crankcase blow down the walls of the cylinder oil, increasing cylinder wall wear; elastic is too large, directly aggravate the wear of the cylinder walls, or because of the cylinder wall oil film is destroyed and aggravate the wear.