Trailer axle quality is good, production accuracy is very important

If the quality of a trailer axle is not up to standard, it can not only look at strength and toughness, but also production accuracy is key.

Although the trailer axle looks relatively simple and bulky, it seems that the word "precision" is not quite on the edge, in fact, it is a veritable precision machinery, and the components of a trailer axle are as high as 100. Because of this, it is very important to control the processing accuracy of the trailer axle.

Next, let's take the DARO trailer axle as an example to see which processes in the production process are used to ensure the accuracy of the finished product.

1. Straightening of axle

The straightening process is generally set after heat conditioning treatment and sand blasting to correct various bending caused by the production and processing of the axle.

Although the strength and toughness of the axle have been stimulated to a certain extent after the front hot rolling, hot tempering, sandblasting and other processes, it is still impossible to completely avoid the subtle bending phenomenon of the axle that cannot be recognized by the naked eye during the processing process, especially in the process of hot tempering treatment.

If it is not restored to deformation through the straightening process, it will directly affect the stress distribution of the shaft beam or shaft end parts in use, light will produce body vibration, driving instability, heavy will lead to axle cracks or direct shaft breakage, affecting driving safety.

DARO trailer axle is an automatic multi-point straightening machine, the accuracy can reach 0.4-0.5mm, can automatically correct the various bending phenomena of the axle in the process of processing or heat treatment, providing the basis for the processing accuracy of the finished product.

2, CNC machine tool processing

CNC machine tool processing is set after the primer process, before the intermediate frequency strengthening treatment, mainly for the shaft bore, turning milling, drilling, precision grinding and so on.

CNC machine tool processing is mainly for the shaft head position, to the subsequent shaft head installed hub, bearing, brake drum and other parts to provide the installation basis, is equivalent to the existence of the foundation of a high-rise building, the higher the processing accuracy, the more can lay a good foundation for the subsequent assembly accuracy, to avoid unnecessary friction loss of wheel end parts, improve the reliability of the wheel end system. The longer the maintenance cycle.

Compared with ordinary machine tools, CNC machine tools can write the processing parameters into the numerical control device in a program, such as the trajectory size of the relative movement of the shaft head and the tool, the grinding process parameters and various auxiliary operation information, and then the numerical control device is analyzed and processed, and the signal and instruction corresponding to the program are issued for automatic processing.

In this way, not only the processing efficiency is higher, but more importantly, the stability of the processing is stronger, because the operation of the CNC machine tool is controlled by continuous calculation, output and feedback, which can ensure the accuracy of the relative position of the tool and the shaft head, avoid human error, and the processing quality is more stable.

3, automatic welding

In the production process of the axle, the welding work is much less than that of the trailer production, and it is mainly used in the welding of parts such as the brake floor, spherical bearings, and air chamber seats. After the welding is completed, you can get the axle welding semi-finished product, which is also one of the main products of DARO trailer axle.

The welding process of DARO trailer axle adopts robot automatic welding, and uses laser locating system to track and identify the position of the weld, ensuring the consistency, beauty and firmness of the weld, and more stable welding quality.

4. Finished product assembly

The assembly needs to install the wheel hub, brake drum/brake disc, internal and external bearings and other components on the basis of welding semi-finished products to obtain the finished axle. After the end of the production process, enter the finished product quality inspection link.

The assembly accuracy mainly includes the dimensional accuracy, relative motion accuracy, mutual position accuracy, contact accuracy, etc., among which the dimensional accuracy also includes the matching accuracy and distance accuracy, and the precision control of the assembly process is mainly divided into two points: the accuracy of the parts themselves and the accuracy of the assembly technology.

In order to better ensure the accuracy of parts, DARO trailer axles choose purchased parts, such as bearings, wheels, brake drums, etc. all choose domestic strength brands, which are among the best in their respective fields. On the one hand, these brands have been deeply engaged in the accessories industry for many years, and the quality has been baptized and tested by the market, and has the corresponding quality assurance ability; On the other hand, after the arrival of the accessories, DARO also has to carry out a series of tests on its strength, accuracy, etc., and can be put into use after passing the test, adding a layer of guarantee to the quality.

In terms of assembly technology accuracy, DARO trailer axle selected an automated assembly line, with high-precision guidance, positioning, feed, adjustment, detection and other instruments, in highly repetitive assembly tasks, to ensure the high accuracy and consistency of the assembly process, and fully reduce or reduce the unqualified rate.

In fact, in addition to the previously mentioned hot spin rolling, hot tempering, intermediate frequency strengthening and axle alignment in this period, CNC machine tool processing, automatic welding, finished product assembly, the production process of DARO trailer axle also set up raw material cutting, shaft head preliminary treatment, cold push square, shot blasting, primer spraying, top paint spraying, shaft head accuracy inspection and other processes. They complement each other and cooperate with each other to jointly cast the quality cornerstone of the finished axle.