Study On Multistage Cold Precision Forging Process And Die Of The Shaft In Gear-box

The shaft used in gear-box is a kind of important parts of the car, in recent years, with the rapid development of automobile, there is a much stricter demand for shaft's manufacturing. The shaft has a great variety with the simple shape characters; its principal characters are tenuous, multi-step and highly requested quality. Multistage cold precision forging of shaft with a lot of advantages comparing to conventional shaft shaping, such as material saving, better mechanical properties and higher productivity etc, multistage cold precision forging has become the developing trend of manufacturing shafts. Based on the rapid development of our native car's manufacture and the project requirements of the"Development on multistage cold precision forging process and equipment of the shaft in gear-box"which is taken by our research team, this paper mostly discussed the multistage cold precision forging process and die of the shaft used in gear-box.Through reading the national and the international literatures, the author got to know the connotation and types of precision plastic forming process, status and the developing trend of cold precision forging technology. Besides, the author analyzed and knew the status and the developing trend of shaft forming technology.According to the given shaft used in gear-box, cold precision process has been analyzed. Based on the forming rang of the ironing process and principle of the heading process, the author has set down multistage process picture sheet of the given shaft, calculated and confirmed the processing parameter, researched the matching relations of processing parameter among every step.The multistage cold precision process of input shaft and output shaft were simulated using rigid-plastic finite element method, so that the change rule of the distributions of the stress, strain, damage and the stroke-load curve etc have been researched.The five-stage cold precision forging die were designed according to the multistage process picture sheet, further more, the principle and method of designing multistage cold precision die have been put forward. Based on the above-mentioned theoretical study, the multistage cold precision forging process of trail draw ring in the car has been researched with the gaining of the qualified forging part, which was taken as the physical simulation of the multistage cold precision forging of input shaft and output shaft according to the similar geometry and uniformity processing among the draw ring shaft and input shaft and output shaft, one purpose is to verify the effect of FEM simulation, the other is to optimize the multistage cold precision forging processing parameter of input shaft and output shaft.