The engine cylinder liner and piston ring are a pair of friction pairs operating under high temperature, high pressure, alternating load and corrosion. Long term work in complex and changeable conditions results in the wear and tear of cylinder liner, which affects the power, economy and service life of the engine. It is very important to analyze the causes of the wear and deformation of the cylinder liner for improving the economical use of the engine.
I. Analysis of the causes of the wear of the cylinder liner
The working environment of cylinder liner is very bad, and there are many reasons for wear. Regular wear is normally allowed for structural reasons, but improper wear and tear will result in abnormal wear.
1 wear caused by structural reasons
1) the lubrication condition is bad, so that the upper part of the 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 evaporated fuel intensifies the deterioration of the upper conditions, causing the cylinders to be either dry or semi dry friction, which is responsible for the severe wear on the upper part of the cylinder.
2) the upper part to bear the pressure is big, causes the cylinder to wear upward. 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 stroke, as the piston down, the positive pressure gradually decreases, so the cylinder wear is heavy, light down.
3) mineral acids and organic acids cause the surface of the cylinder to corrode and flake. 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) to enter the mechanical impurities, so that the middle of the cylinder wear increased. 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, the wear in the middle of the cylinder is aggravated due to the maximum speed of movement in the middle part of the cylinder.
2 wear caused by improper use
1) 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 cause the abrasion of the inner sleeve of the cylinder liner.
2) beiben V3 accessories air filter filtration efficiency is low. The function of the air filter is to remove dust and sand from the air entering the cylinder to reduce wear of the cylinders, pistons, and piston rings. Experiments have shown that if the engine is not equipped with air filter, the cylinder will be increased by 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 time low temperature operation, the first cause poor combustion, carbon deposition from the upper part of the cylinder liner began to spread, so that the upper part of the cylinder liner serious abrasive wear; two is caused by electrochemical corrosion.
4) the use of inferior lubricants is often used. Some owners of the road to save money, often in roadside shops or to unscrupulous oil traders buy inferior lubricating oil use, resulting in the upper part of the cylinder liner strong corrosion, its wear and tear than the normal value of 1-2 times larger.
3 wear caused by improper maintenance
1) improper installation of cylinder sleeves. When installing the cylinder fittings of the North V3 fittings, if the installation error is in place, the center line of the cylinder and the crankshaft axis are not vertical, which will cause abnormal wear of the cylinder liner.
2) copper sleeve hole deviation 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.
3) bending deformation of connecting rod. Due to car accidents or other reasons, the connecting rod of the impact will produce bending deformation. If it is not corrected in time, it will also accelerate the wear of the cylinder liner.
4) north running V3 fittings, crankshaft, connecting rod journal and spindle neck are not parallel. Because of engine burning, tile and so on, will cause the crankshaft due to severe impact and deformation, if not corrected in time and continue to use, will also accelerate cylinder liner wear.
Two, to reduce the wear of cylinder liner measures
1. proper starting and starting
Cold start, due to low temperature, oil viscosity, poor mobility, so that the oil pump oil shortage. 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, the engine should be a few laps, until the friction surface lubrication, and then start. 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.
2. choose lubricating oil correctly
It is necessary to select the best viscosity value according to the season and the engine performance. It is not possible to buy inferior lubricating oil at will, and check and maintain the quantity and quality of the lubricant frequently.
3. strengthen the filter
Keeping the air filter, oil filter and fuel filter in good working condition is very important for reducing 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. Some drivers are absolutely wrong not to install air filters to save fuel.
4. maintain normal working temperature
The normal operating temperature of the engine shall be at 80-