Conventional trailer suspension structures are mostly found in leaf springs, airbag suspensions, and a rare type of rubber suspension. In terms of economy and loadability, of course, leaf spring suspensions have more advantages, and balance beams and axle pins are leaf springs. Part of the suspension structure, let’s introduce each of their functions and damage symptoms.
(1) Balance beam: The trailer balance beam is located in the middle of the front and rear two sets of leaf springs. Its working principle is like a “seesaw”. As the fixed point of the steel plate floating frame, it also balances the bearing capacity between the axles. , So that when the vehicle is driving on an undulating road, the force of each axle is more even.
Generally, balance beams are not easily damaged. Many of them are caused by excessive load, which leads to excessive wear of the steel plate floating frame and the top of the balance beam. All forces are exerted on the axle pin, and this axle pin is like a “traction pin”. “It has the same effect, combining the steel plate support with the balance beam.
Common balance beam damage occurs on heavy-duty vehicles, and the solder joints are cracked directly on the top of the balance beam. After all, this is a fixed part of the chassis structure, which has been welded before the trailer leaves the factory. If the vehicle type is loaded, it will be replaced almost for life, as long as the axle pin and bearing hole are welded and replaced.
(2) Axle pin: In fact, from a structural point of view, the axle pin and the balance beam should be integrated. The reason why the two are introduced separately here is precisely because you need to pay attention to when replacing, if the balance beam is not the base worn Too serious, the bearing hole cannot be repaired by welding, only the shaft pin needs to be replaced, and its appearance looks like a round shaft body.
When working, the axle pin serves to combine and limit the movement range of the balance beam and the steel plate floating frame. Even if it is a cylinder, I believe everyone has heard a saying, “As long as the work is deep, the iron rod is ground into a needle”, it will not be used for a long time. Maintenance and replacement, this axle pin will also lose round due to wear, thus losing the role of balance.
If it is standard-load transportation, high-speed road conditions are the main operating conditions, and national road conditions are supplemented The butter plays a role in protecting the shaft pin. You can also check the gap between the shaft pin and the bearing hole of the balance beam when applying butter. If it is loose, it means that the replacement cycle has been reached.
The safe replacement cycle for both of the above operating conditions is one year or 200,000 kilometers. The balance beam bearing hole and axle pin are replaced as a whole, so as to avoid tire eating and strong bounce of brake tires. If the trailer has ABS , It will also affect the effect of ABS.
The first thing that brings is the difference in the bearing capacity between the axles. When you can’t associate the brake system with the suspension system, it is their “insufficient coordination that caused the failure.” The ordinary three-axle trailer is in the air When the vehicle is under load or heavy load, the load distribution of the three axles is uneven. When the vehicle is braking, the wheel with a smaller bearing capacity is more likely to lock up.
When the vehicle is in an emergency slowdown, the trailer wheels will be locked up and there will be crazy bounces. Even if the brakes are adjusted to the same three axles, it will be useless. There will always be an uneven braking force on the axle, which will easily wear the tires. Reduce the braking force, if the domestic ABS anti-lock brake system is installed, then the problem is even more serious.
The four-channel ABS anti-lock braking system is directly out of control. The principle is that when the wheel with small bearing capacity is locked, the other wheels that are not locked will be misjudged by the ABS system to actively reduce the braking force, which will eventually lead to the entire vehicle. The emergency braking distance is greatly extended, which is especially dangerous in rain, fog, ice and snow.
Therefore, when the wheel has the above-mentioned tire eating, abnormal locking and performance failure of the ABS anti-lock braking system, in-depth inspection of the balance beam bearing hole, axle pin and steel plate floating frame on the suspension structure, combined with the actual operating conditions, is appropriate Reduce the cycle of buttering and overall replacement to prevent excessive wear of the trailer suspension structure.
Again, the vehicle is composed of countless parts and components. Failure of any one component will cause the vehicle to be unable to drive. Therefore, to maintain a car, you must not only be able to drive, but also maintain and inspect the vehicle. When a vehicle is faulty, find out early. , Repair as soon as possible to avoid major damage caused by minor faults, so as to obtain greater profits in the era of small profits.