7 reasons for diesel engine cylinder wear are as follows:
Take 6135 diesel engine as an example, cylinder liner and piston ring, the pair of friction pairs, are working under high temperature, high pressure, alternating load and corrosion, and their friction and wear are particularly complicated. The service life of the domestic cylinder liner is about 5000h according to standard. But in actual use, it often fails to reach this rule. The reasons are mostly used for repair. As a result of misconduct, there are the following points:
The filtration efficiency of the 1 air inlet air filter is reduced, or the air inlet pipe is sealed badly, that is, the dust in the air will be inhaled in a large number of air cylinders, causing serious abrasive wear in the upper cylinder liner. The test shows that a good performance air filter has a filter efficiency of more than 99%. Only 50~70% dust can be separated. About 50h, the cylinder liner may wear out Imm..
2 oil filter filter cleaning effect is poor, because the oil is not clean and contains a large number of hard particles, the inner wall of the cylinder sleeve will be worn down from the bottom to the ground. Some contrast tests show that the filter cleaning effect of the oil filter can make the cylinder liner wear a lot of difference.
The poor quality of the 3 lubricating oil, if the sulfur content of the oil used is too high, causes the first piston ring to corrode strongly at the top stop and produces corrosive wear. Its wear amount is l~2 times larger than that of normal, and the particles that corrode and peel off will lead to serious abrasive wear in the middle of the cylinder liner.
4 cylinder sleeve improper installation of 6135 diesel engine used wet cylinder sleeve, because of the cylinder sleeve installation error, the cylinder center line and crankshaft axis is not vertical, so the cylinder sleeve will cause abnormal wear. The improper installation of cylinder sleeve is caused by the installation error of the waterproof rubber ring on the cylinder sleeve. The correct installation method is the trap. After the groove of the outer wall of the cylinder liner, it should be inserted between the circle and the cylinder liner a few circles, in order to prevent the distortion of the rubber ring and make the surrounding tension uniform. This can strengthen the sealing function of the ring and prevent the rubber ring from pressing the cylinder sleeve when the cylinder sleeve is pressed.
The 5 connecting rod is flexed by the impact of the connecting rod, often resulting in distortion. If it is not corrected in time, it will continue to be used, which may lead to the early wear of the cylinder liner.
6 boring cylinder quality is not high 6135 diesel engine requires cylinder sleeve boring cylinder, the internal and external surface of the different axial degree should not be more than 0.1mm, the wall thickness difference is not more than 0.15mm. if the internal and external surface of the different axial degree of overlimit, that is, the cylinder liner may be early wear.
After the cylinder sleeve boring cylinder, the inner circle of the working face is too smooth, the oil oil film is even below 5um, but it is unfavorable lubrication, it will cause early wear. But the surface is too rough, the lubricating oil is too much and the working performance will deteriorate. So the inner wall of the cylinder sleeve should be grind mesh as good, both for lubrication, and also to reduce wear.
7 the diesel engine which has not been repaired after the time limit is not done well, that is, to run in a hurry, it is also easy to cause the early wear of the cylinder liner to wear.6135 diesel engine as required. In the initial operation of 60H after the overhaul, the power use should be appropriately reduced, preferably not exceeding the rated work rate of 80%..
The cylinder sleeve of the diesel engine has dry and wet types. Taking the Cummins 6BT5.9 and the WD615 diesel engine as an example, the wall thickness of the dry cylinder sleeve is only about 2mm., because the inner hole of the thin-walled cylinder sleeve does not leave the boring allowance, so the cylinder sleeve size must be very accurate. It is necessary to use it. As required, the thin-walled dry cylinder sleeve is usually high out of the upper plane 0.02~0.lOmm of the cylinder body to prevent the air leakage from the cylinder pad. When replacing the cylinder sleeve, a special puller should be used to remove the cylinder sleeve. The cylinder sleeve can be further boring, but the cylinder sleeve can be taken out easily. Boring, so as not to damage the bore of cylinder sleeve.
When the dry cylinder sleeve is replaced, if the cylinder sleeve is tight with the cylinder body, and there is no mechanical equipment, the 6102 diesel engine is used as an example, and the same type of waste piston can be used to make a simple tool. It will be more convenient to disassemble.
When making this tool, the l~2 root ring is installed on the ring groove of the piston, and a circular rod with circular rings is made with round iron around 8mm diameter. (the center distance of two circles is required to be about 50mm longer than the center distance of the connecting rod two L Center), and the old piston pin is mounted on the piston.
When the piston ring exceeds the lower end of the cylinder sleeve, the piston ring will be automatically opened and stuck in the cylinder sleeve. Then the cylinder is lifted up with a rod through the rod, and the cylinder sleeve can be easily removed.
The wet cylinder sleeve of the new diesel engine is mainly divided into two types in structure. One is that the waterproof ring is installed in the ring groove of the outer ring of the cylinder sleeve, the other is in the ring groove of the bottom hole of the cylinder sleeve. As for the maintenance and assembly, the two kinds of cylinder sleeves have their advantages and disadvantages. However, a common key is the assembly quality of the waterproof ring.
The wet cylinder liner of various types of diesel engines is different, the specifications are different, and there are some color differences. For example, the Japanese wild DM100 diesel engine has two different colors of waterproof ring, the black is installed on it, the light brown is installed below. In the maintenance, we should try to meet the technical requirements of the factory. If there is no information, it can be dismantled. Pay attention to the condition of the original.
When the waterproof ring is loaded into the cylinder ring groove, the height outside the convex groove should be checked. The specific size of the diesel engine of various types has specific requirements. For example, Japan's wild DM100 diesel engine usually requires this value of about 0.5mm. If this value is too low, it will leak water. Too high the cylinder sleeve can not be pressed in, or the waterproof ring is crushed. A wet cylinder sleeve is replaced. When waterproofing ring is used, it should also be noted that the waterproof ring can not be reused. If it is removed, it must be replaced.
