In recent years, with the rapid development of China's logistics industry and construction industry, the load of heavy vehicles has gradually increased. In order to reduce the axle load and at the same time to improve driving safety and stability, heavy-duty vehicles increasingly use dual front axle steering mechanisms. Compared with the single front axle car, the double front axle car is more prone to wear on the front tires, because the parallelism of the double front axle will directly affect the tire wear. Regarding the parallelism of the front axle assembly, we occasionally found that the car in front drove skewed like a crab, because the arrangement of the front and rear axles was inconsistent. Of course, under normal circumstances, it is difficult to see that the car is skewed, but it will cause the problem of severe tire wear. Especially on double front axle heavy goods vehicles, the parallelism of the front axle has a great influence on the abnormal wear of the front wheels. Since the parallelism will have a great effect on the abnormal wear of the tires and it is impossible to keep the two front axles completely parallel, then what requirements should the parallelism be assembled and checked during the assembly process?
1. Straightedge adjustment method: Use a straightedge with reference plane flatness ≥0.02, first put its reference surface against the left hub surface of the first front axle to make it completely contact with no gap. Then, by adjusting the length of the auxiliary straight rod, the left hub surface of the second front axle is also completely in contact with the ruler reference surface. Because it is an assembly process, in order to improve the accuracy and ease of operation of the vehicle, as long as there is no gap between the reference surface of the ruler and the hub surface. If this method is used to check the parallelism of the vehicle, the rim surface of the first front axle and the ruler reference surface are closely attached, and then the gap surface is used to check the left hub surface of the second front axle and the clearance.
2. Laser instrument adjustment method: A set of laser emitters are used, which are fixed on the hub surface of the second axle through a magnet base and irradiate toward the direction of the first axle. On the first axle, a set of reflecting devices (the main body is an optical mirror) is fixed with a magnet holder to reflect the laser beam back. A scale panel is installed on the transmitter panel, and a scale mark is provided on the scale panel, and the parallelism of the 2 axles is judged according to the position where the reflected laser beam falls on the scale panel. If it is not parallel, adjust the auxiliary straight rod according to the position of the laser beam until it is parallel.
The parallelism of the front axle assembly of the double front axle heavy truck has a very important influence on the wear resistance of the tire, and the wear resistance of the tire directly affects the customer's judgment on the quality of the vehicle and the safety performance of the car, thus affecting the entire Word of mouth in the market. Therefore, ensuring the parallelism of the front axle is a very important link in the assembly process of the vehicle. Careful calculation and review should be made to ensure the accuracy and method of parallelism to ensure the parallelism of the front axle when the vehicle is off the assembly line.