The most popular way out of the misunderstanding o

Get out of the misunderstanding of maintenance of construction machinery

1 new products are not selected and matched

when replacing the cylinder liner piston, the size grouping code of the standard cylinder liner and piston must be checked, and the installed cylinder liner and piston must have the same size grouping code, so as to ensure the standard fit clearance

2 the cylinder clearance measurement is inaccurate. If there is looseness, the clearance in the direction of the long axis of the ellipse shall prevail during the measurement, That is, measure the clearance of the piston skirt perpendicular to the direction of the piston pin hole. This measurement is more convenient and accurate

3 piston heated by open fire

the piston is directly heated by open fire. The thickness of each part of the piston is uneven, and the degree of thermal expansion and contraction is different, which is easy to cause deformation. If it reaches a certain high temperature, the metal structure will be damaged after natural cooling, which will reduce the wear resistance of the surface quality of modified polypropylene material, and the service life will be greatly shortened

4 abrasive cloth grinding bearing bush

in order to increase the contact surface between the Bush and the shaft, many maintenance workers grind the bearing bush with abrasive cloth. Because the sand particles are hard and the alloy is soft, the sand during grinding is mainly power lithium-ion battery and super capacitor particles, which are easy to be embedded in the alloy. When the engine is working, it accelerates the wear of the bearing bush and shortens the service life of the crankshaft

5 engine oil is only added and not changed.

there are a lot of mechanical impurities left in the used oil. Even if it is discharged completely, there are still impurities in the oil pan and oil circuit

6 messy use of lubricating grease

some repairmen like to apply a layer of lubricating grease on the cylinder gasket when installing the cylinder gasket. The cylinder gasket not only requires strict sealing of the high-temperature and high-pressure gas generated in the cylinder, but also seals the cylinder head and the cold water with a certain pressure and flow rate in the cylinder body. It is widely used in the material industry to neutralize engine oil, and apply lubricating grease on the cylinder gasket. When the cylinder head bolts are tightened, Part of the lubricating grease will be squeezed into the cylinder water channel and oil channel. When the cylinder is working, the high-temperature and high-pressure gas is easy to impact from here, damaging the cylinder pad and causing air leakage. In addition, when the grease is at high temperature for a long time, carbon deposition will occur, causing premature aging and deterioration of the cylinder gasket

7 bolts are tightened too tightly

too much preload will cause screws and bolts to break or thread slippage, etc

8 too high tire pressure

too high or too low tire pressure will affect its service life, but also detrimental to safe driving

9 the water tank "boils" and suddenly adds cold water

sudden adding cold water will cause the cylinder head and cylinder block to "burst" due to excessive temperature difference. Therefore, once the water tank is found to be "boiling", emergency measures should be taken to ensure that the engine cooling water cools down by itself