The gearbox gear of heavy truck is one of the three major products of ZHY Gear. It has been supporting Qingdao heavy truck of FAW Group and Liuzhou heavy truck of FAW Group for a long time. There are three types of gears in the gearbox:
- It is a shaft part. The representative parts are input shaft, intermediate shaft and output shaft. There are various splines on the shaft. It is required to control the size of heat treatment:
- Clutch parts. Most of these parts are complex in shape, mostly thin-walled. They are almost finished products during heat treatment, with high deformation requirements;
- It is meshing gear, which is represented by shift gear with spline combined teeth. After spline heat treatment, it must meet the requirements of finished products and heat treatment control accuracy.
These parts require high-precision carburizing and quenching heat treatment process, which is different from the ordinary carburizing and quenching treatment of ZHY Gear’s traditional marine gearbox products. Therefore, the heat treatment of heavy truck gearbox gear brings us to a new height and brings us new challenges.
At present, the gear steel for the gearbox of ZHY Gear heavy truck is mainly 20CrMnTiH steel, with a small amount of 20mncr5 and 19cn5. The supply of steel mainly comes from domestic special steel mills. At present, designated steel mills have begun to purchase. However, in the actual production, due to the restriction of market channels and prices, the source of materials is still relatively complex, so it is impossible to really achieve fixed-point procurement, which brings unstable factors to heat treatment. In addition, because the scale of ZHY Gear products is far from reaching the mass production of modern production, its production is also affected by other products of the company, and the machining form is often unstable. Therefore, it is quite difficult to stably control the heat treatment deformation of automobile gears for heat treatment.
Therefore, the heat treatment department has been actively coordinating the cold working process, repeatedly studying various process links, continuously testing and improving the process according to the specific conditions of different types of parts, and strive to find a set of effective heat treatment process methods suitable for the production mode of the company to control gear deformation, so as to meet the production needs of our company.