The development of precision forming technology is extremely important to a country’s industrial development. European and American countries have long listed precision forming technology as a national priority development goal, and China has also listed the development of precision forming technology as a national priority development field.
Gear plays an extremely important role in mechanical transmission. Its production technology level represents the development level of a country’s machinery industry to a certain extent. Due to the low material utilization and production efficiency, the traditional method of producing gears can not meet the growing needs of social production. Using precision forging technology to manufacture gears not only has the characteristics of high production efficiency, high material utilization and less subsequent processing procedures, but also can form metal fiber structure evenly distributed along the tooth profile with less micro defects, so as to significantly improve the mechanical properties of gears. Due to the difficulty of spur gear precision forging technology, especially the problems of insufficient tooth filling, large forming load and serious die wear, the precision forging technology of spur gear has not been applied to the actual production. Therefore, based on the precision forging technology of spur gears at home and abroad, finding a reasonable precision forging technology of spur gears has important theoretical significance and practical value for the development of precision forging technology of spur gears. According to the research status of precision forging technology of spur gears at home and abroad, the main research contents are as follows:
1.Comprehensively analyze the precision plastic forming process methods of spur gears at home and abroad, and put forward to study the forming of spur gears by forward extrusion process.
2.Analyze and determine the cold extrusion forming process and die structure of spur gear.
3.Through the design of orthogonal test, the effects of process parameters – die insertion angle, working belt length, gross diameter coefficient, friction coefficient and extrusion speed on the forward extrusion forming of spur gear are studied, the most important influencing factors and the optimal combination of process parameters are obtained, and simulated and verified.
4.Based on the simulation results of orthogonal test, in order to improve the effective gear length of spur cylindrical gear after forming, the preform design of return material and the optimization design of die structure are carried out, and the measures to improve the extrusion quality of spur cylindrical gear are studied.
5.Study the elastic deformation of the die and the elastic recovery law of the gear after the cold extrusion of spur gear, and get the dimensional deviation of the product. According to the principle of die size compensation, the accurate design of die cavity size is realized.