Inspection method for failure of shock absorber
Failure inspection method
(1) Vibration test: park the vehicle at a stable place, press the front of the vehicle (the hood of the vehicle) with force and let go suddenly. It is normal if the vehicle body swings up and down within three times when it bounces. If it shakes up and down continuously, the shock absorber may lose its function. The more serious the vibration phenomenon is, the more serious the damage level of the shock absorber will be. In order to improve the accuracy of discrimination, it can be compared with normal vehicles of the same model.
(2) Manual inspection: remove the shock absorber from the vehicle, place the shock absorber vertically, pull and press the piston rod of the shock absorber with hand at a constant speed to determine whether the damping force of the shock absorber is abnormal. If there is no obvious resistance, it can be determined as failure. Compared with the normal shock absorber, if there is obvious free travel, clamping stagnation, etc., the shock absorber is damaged. To judge whether the shock absorber has free travel, the shock absorber must be placed vertically, and the determination shall be stopped after repeated tension and compression.
⑶ Visual comparison method: check the tire runout from another vehicle, and compare with other normal vehicles to determine the damping force attenuation of the shock absorber. The visual inspection can also check the oil leakage of the shock absorber.

The time allowance given by the thermal capacity of the motor shall be considered for the above three modes. It is difficult to make it consistent with the thermal capacity characteristics of the motor in a single way. Therefore, it is necessary to select a method that can act reliably according to the cause of overload - combined composite mode to achieve comprehensive overload protection. The mine explosion-proof pneumatic butterfly valve motor has a thermostat embedded in the winding with the same insulation level as the motor. When the rated temperature is reached, the motor control circuit will be cut off. The thermal capacity of the thermostat itself is small, and its time limiting characteristics are determined by the thermal capacity characteristics of the motor, so this is a reliable method.