Research On Cold Forging Technology Of Spur Gear And Simulation

Spur gears with complicated shapes are important drive parts applied widely in the automobile and mechanical industry. Therefore, high material quality, dimension precision, surface quality and combination mechanical properties should be attended. In this paper, taken the spur-gear's cold forging as the research subject, the forming technology and the numerical simulation of the forming process are studied, which is important to enrich and develop the theory and technique of the cold forging and improve the forming design level of spur-gear parts' cold-and-precise forging.The cold forging of the spur gear is a complicated three-dimensional forming, and its process and precision are influenced by many factors. The elastic-plastic finite-element analysis application software ANSYS is used to numerically simulate the forming process, analyze and study the influence of divided-flow mouth diameter size on the forming force and the gear filling property. Then, the concept of end-face shape function of male punch is presented, and the impact of end-face shape function on the gear filling property and the material non-uniformity of forming were analyzed. Furthermore, the stress field, strain field, displacement field and metal's flowing state were obtained; the forming regularity and the impact of main factors on the forming process and precision of the gear were studied, which play a leading role in the forming process and die design for the spur-gear cold forging.Based on the analytic results of the numerical simulation and applying the precise plastic forming theory, the forming process and the mould structure for the spur-gear cold forging were designed properly. And it pointed out that applying forging divided-flow theory is an effective method to decrease the working load and using a rake-angle male punch may greatly improve the radial filling property during the forging of the gear.Finally, by the coordinate-mesh method, the flowing state of metal forming during forming process was tested and verified, which illustrated the feasibility and rationality of the forming process.