At present, most domestic truck weight limits are distinguished according to the number of truck axles, and the truck weight limits of different axles are inconsistent. China's freight market is complex, and the situation of freight vehicles is uneven. The problem of freight vehicles in China is large weight, few axles, long length, but few junction points. Therefore, the weight of the vehicle is limited by the number of axles.

According to the existing national standard gb1589, the total mass limit of 2-axle truck is 18 tons, that of 3-axle truck is 25 tons, that of 3-axle truck is 27 tons, that of double steering axle 4-axle truck is 31 tons, that of 4-axle truck is 36 tons, that of 5-axle truck is 43 tons, and that of 6-axle truck is 49 tons.

As for the load limit of 7-axle semi-trailer, there is no specific provision, but you can refer to the load limit of 6-axle semi-trailer. Or if you need to pull some overweight goods, you need to go to relevant departments for filing.

The situation of each truck is different, and the load limiting mass is different. It also depends on whether the axle mass of the truck or semi-trailer can pull so many goods. The axle quality of semi-trailer directly affects the driving safety of our truck under full load. How can high-quality semi-trailer axle be manufactured? According to the consulting data, we conclude that the manufacturing of high-quality axle needs at least more than ten manufacturing processes to make a qualified semi-trailer axle.

The production process of qualified axle is as follows:

1. Blanking / raw material cutting: small heat affected area for subsequent processing.

2. Hot rotary rolling: the temperature can reach 1300 ℃, which greatly reduces the plastic resistance and deformation energy consumption of raw materials, improves the processing performance of raw materials, reduces or eliminates casting defects and improves the comprehensive mechanical properties.

3. Shaft head processing: cut the shaft head according to the drawing requirements to ensure that the size of the shaft head meets the requirements.

4. High precision shaft tube forming: one-time cold push square forming, high-precision control extrusion, reduce or avoid workpiece bending, and enhance the mechanical properties of shaft tube.

5. Full automatic medium frequency quenching: digital medium frequency induction quenching machine is adopted, the whole line is processed automatically, the operation accuracy is high, the high temperature setting at 890 ℃, and the stiffness, wear resistance and fatigue strength of the shaft body are enhanced.

6. Integrated shaft tube heat treatment: 480 ℃ shaft body heat treatment to reduce or eliminate quenching internal stress and improve ductility and toughness of shaft body.

7. Shot blasting and derusting: clean the residual oxide scale and oil stain after heat treatment process, polish the surface of shaft pipe, improve the finish, and make the shaft pipe more beautiful and precise.

8. Online straightening: automatic multipoint straightening equipment is adopted, and the accuracy can reach 0.4-0.5mm.

9. CNC precision grinding: finish the shaft body to ensure high precision and improve safety performance.

10. Medium frequency induction treatment: strengthen the key bearing parts of the axle body to improve the safety and stability of the axle to a greater extent.

11. Secondary finishing: further carry out fine processing according to the size and thickness of the medium frequency induction processing area to strictly ensure that the finished products meet the drawing requirements.

12. Complete inspection of axle tube.

13. Automatic gas shielded welding: reduces welding heat input, reduces and avoids welding deformation, has strong weld crack resistance, and further improves axle performance.

14. Painting + electrophoresis process: prolong the paint adhesion life and improve the protection of the shaft.

The above is the treatment process of Darong axle when manufacturing trailer axle. It can be seen how complex the manufacturing process of a qualified axle is. Only through these processes can we meet the stable vehicle performance of trailer under heavy load. Darong axle has been established for more than 20 years, focusing on the production and manufacturing of trailer axles with strong technical strength. At present, the company has built a standardized production workshop of more than 30000 square meters, an industry-leading automatic production line and automatic assembly line to realize the standardization and standardization of products. Let users buy axle products at ease.