Five taboos for daily maintenance of match oil mac

Five taboos for daily maintenance of diesel engine

one taboo is to replace the cylinder gasket without removing the residual cylinder gasket. At present, some cylinder gaskets are graphite products, which have strong adhesion and good sealing, and can only be used once. When removing the graphite cylinder gasket, the residual old cylinder gasket adhered to the plane of the machine body and cylinder head must be removed. Because the sundries adhered to the contact surface of the engine body and the cylinder head are uneven, the cylinder pad is not compacted after installing the cylinder head, which can not withstand the impact of high-temperature and high-pressure gas when the diesel engine is working, and it is easy to damage the cylinder pad again

second, do not install the piston pin without heating the piston. The aluminum piston expands greatly when heated, and the piston pin should have a certain tightness when installed into the piston pin hole at room temperature. During installation, the piston should be heated to about 90 ℃ in oil or water in advance, and then take out the piston. When it is hot, the piston pin can be smoothly pushed into the piston pin hole by hand (pay attention to the assembly direction)

three taboos: replace the valve without grinding. In order to ensure the tightness of the valve, when replacing the valve and valve seat, first use the valve reamer with appropriate angle to cut, then apply the grinding paste between the valve and valve seat, and grind with the valve grinder or manually until a 1 ~ 1.5mm wide, neat and dark gray continuous ring belt is grinded. The method to check the valve sealing: after cleaning the valve assembly, reinstall it on the cylinder head according to the original position, pour gasoline into the inlet and exhaust passages respectively, and observe that there is no leakage at the joint of the valve and the valve seat after 1 ~ 2 minutes, which indicates that the sealing is good

four taboos: pad iron sheet or paper on the back of bearing bush. The wear of crankshaft journal and bearing bush exceeds a certain range, which increases the clearance. In the work, due to oil leakage, no wonder Langsheng company is planning to build an advanced glass fiber production plant. The oil pressure is reduced, resulting in poor lubrication, increased wear, and abnormal knocking sound. Repair method: the crankshaft should be removed and sent to the repair shop for grinding with a crankshaft grinder, and then the thickened bearing bush with appropriate size should be equipped to restore its original performance. If the iron sheet or paper is padded on the back of the bearing bush, it can not reduce the gap between the shaft and the Bush, but also deform the bearing bush when the crankshaft is under pressure, damaging the original gap, especially causing great changes. The paper padded can greatly reduce the heat transfer performance

five taboos: replace the oil indicator with a peg. After the diesel engine is started, the oil indicator rises, which not only marks that the diesel engine is well lubricated, but also exposes the oil spray hole, so that the oil can be sprayed out from the hole, lubricate the back shaking mechanism, and make the diesel engine work normally. However, some operators found that the oil indicator was damaged, pulled it out and threw it away, smashing it into the peg. The peg will block the oil spray hole, and the back rocking mechanism will not be lubricated by oil. Accelerating the wear of parts is the maximum acceptable limit of the host