Generally speaking, the precision forging technology of spiral bevel gear has been greatly developed in theoretical research, process test, engineering application and so on. However, due to the characteristics of large size, complex structure and high material strength of automobile rear axle driven spiral bevel gear, the following problems still need to be solved in its precision forging process:
(1) low material utilization rate. The driven spiral bevel gear has a large outer diameter and a through hole with a large diameter in the middle. Using the traditional blank making method, the material utilization rate is very low. Therefore, it is necessary to put forward a reasonable forming process route according to the structural characteristics of the driven spiral bevel gear, so as to maximize the material utilization rate.
(2) The filling of tooth profile is not full. Due to the complex structure of spiral bevel gear, it is often difficult to fill the corners of gear teeth in the forging process, resulting in unqualified products. The primary task of precision forging is to design a reasonable pre forming process scheme, improve the flow filling ability of metal and ensure the forming quality.
(3) Low forming accuracy. Ensuring the tooth profile accuracy is a challenge to the forging production process of spiral bevel gear. The die cavity determines the accuracy of the gear. Due to the complex thermal deformation and elastic deformation of the die in the forming process, it has an important impact on the accuracy of the formed parts. How to effectively improve the gear assembly through die design and process selection Shape accuracy is an urgent problem to be solved in precision forging process.
(4)The forming load is high and the die life is low. The shape of spiral bevel gear is complex and it is difficult to fill the corners. At the end of the precision forging process, great forming force is often required to ensure the complete filling of the cavity. Under the action of extremely high stress and temperature load, the die life is low. Reducing the forming load and improving the die life are also spiral bevel gears One of the key problems to be solved in precision forging of wheel.