Semi trailer air suspension is a kind of suspension system used in dangerous liquid heavy truck, which is the development trend of dangerous goods tank car. The common fault of the air suspension of semi-trailer is that the air bag is not inflated or the air bag is wrinkled. The causes of the two situations are different, and the treatment methods are also different. In actual situations, they should be treated differently:
The air bag of air suspension has no air.
This situation is relatively simple to check. As long as we know the air circuit structure of the air suspension, we can start from where. The air source of the air suspension is connected from the braking system and stored in the special air reservoir through the pressure protection valve. During operation, it goes through the filter to the core component of the air suspension - height control valve, and then to the left and right airbags.
Reasons for no air in the air suspension airbag:
1. The special air reservoir for air suspension has no air or the pressure is very low. To ensure that the braking system has sufficient pressure, when the trailer air pressure is lower than 0.6 MPA, the pressure protection valve will suspend the air supply to the air suspension air reservoir.
2. The air pipe is blocked or discounted, and the air does not pass.
3. The connecting rod of the height control valve falls off.
4. The height control valve is damaged.
Solution to the problem of no air in the air suspension airbag:
1. Adjust and replace the bent or blocked air pipe.
2. Adjust and install the height control valve connecting rod.
3. Replace the height control valve.
The air bag of the air suspension has air, but the air bag is wrinkled.
Possible causes of airbag wrinkles:
1. When the vehicle is transported and hoisted, the airbag is stretched out a lot and not reset normally, resulting in airbag wrinkles.
2. When the vehicle enters or exits the maintenance workshop or a large slope, it may also cause individual airbags to be overstretched, resulting in airbag wrinkles.
Solution to airbag wrinkle:
Dismantle the connection between the rubber connector under the vertical rod of the height control valve and the axle, lift the rod upward, and install the rod back after all the air bags are fully inflated, so that the air bags can return to normal state. In addition, if such faults often occur during driving, it is necessary to consider adding a limit device between the axle and the frame.
Height adjustment method of air suspension for semi-trailer
1. Park the trailer on level ground and release the hand brake;
2. The crossbar for installing the height valve is loose, adjust the handle, rotate the air bag upward for air intake, and the air bag rises; Rotate the airbag downward to exhaust, and the airbag drops.
3. Note that the adjusting height of the airbag is plus or minus 30mm of the standard height.
