Common faults and maintenance of shock absorber in large class of automobile maintenance
  • Automotive

In order to reduce the vibration of the frame and body quickly, improve the ride comfort and comfort of the car, the vehicle suspension system is usually equipped with shock absorbers. At present, a two-way action cylinder type shock absorber is widely used in the automobile. Shock absorbers are vulnerable parts in the process of automobile use. The work and quality of the shock absorbers will directly affect the stability of the vehicle and the life of other parts. Therefore, we should make the shock absorber always in good working condition. The following methods can be used to check whether the shock absorber works well. 1. make the car stop after 10km on the road with poor road conditions and touch the shock absorber shell with hand. If it is not hot enough, it shows that there is no resistance inside the shock absorber and the shock absorber does not work. At this time, the proper lubricating oil can be added to the test. If the shell is heated, the oil is deficient inside the shock absorber, and the oil should be added; otherwise, the shock absorber is invalid. 2. press down the bumper and then release it. If the car has a 2~3 jump, it will indicate that the shock absorber works well. 3. when the car is running slowly and emergency braking, if the vehicle vibration is more intense, it shows that there is a problem with the shock absorber. 4. remove the shock absorber and hold it upright and clamp the lower end connecting ring on the table forceps and pull the damper several times. At this time, the resistance should be stable. The drag of the upward pull (recovery) should be greater than the downward pressure resistance, such as the instability of the resistance or the no resistance, may be the damage of the oil or valve parts inside the shock absorber, and should be repaired. Replace or replace parts. After determining the problem or failure of the shock absorber, check whether the shock absorber is leaking oil or has traces of old oil leakage. The oil seal washer and the sealing washer are broken and damaged, and the nut of the oil cylinder cover is loose. It may be the damage of oil seal and sealing washer. New seals should be replaced. If the oil leakage is still not eliminated, the shock absorber should be pulled out. If there is a hairpin or light weight, further check whether the gap between the piston and cylinder is too large, the piston rod of the shock absorber is bent, the piston rod surface and cylinder have scratches or scratches. If the shock absorber has no oil leakage, check whether there is any damage, welding, breakage, or shedding of the shock absorber connection pin, connecting rod, connecting hole, rubber bushing, etc. If the above inspection is normal, the shock absorber should be further decomposed to check whether the clearance gap between the piston and the cylinder is too large, the cylinder is pulled, the valve is sealed well, the valve and the valve seat are closely fitted, and whether the extension spring of the shock absorber is soft or broken, and repairs or replacement is taken according to the condition. . In addition, the shock absorber will have a sound failure in actual use, which is mainly due to the impact of the shock absorber with the steel plate spring, the frame or the axle, the damage or shedding of the rubber cushion, the deformation of the shock absorber tube and the insufficiency of the oil, and the reason should be found out. When the shock absorber is checked and repaired, the performance test should be carried out on the special test bed. When the resistance frequency is 100 + 1mm, the resistance of the extension stroke and the compression stroke should be in accordance with the regulations. For example, the maximum resistance of the emancipation CAl091 is 2156~2646N, the maximum resistance of the compression stroke is 392~588N, the maximum resistance of the extension stroke of the Dongfeng car is 2450~3038N, and the maximum resistance of the compression stroke is 490~686N. If there is no test conditions, we can also use an experience, that is to use an iron rod into the lower end ring of the shock absorber, tread on both ends with two feet, hold the ring and pull the ring back and forth 2~4 times with both hands. When pulling up, the drag is very heavy, the downward pressure does not feel laborious, and the tensile resistance is restored to some extent compared with that before the repair. There is no sense of air distance, which indicates that the shock absorber is basically normal.