Research On Hot Forging Process Of Gear Shaft For New Energy Vehicles

Gear shafts are key components in traditional automotive systems.There are many types of shaft components in automotive transmission systems,and their structural characteristics are also different.With the continuous development and promotion of new energy vehicles,higher requirements have been placed on the production of new energy vehicle parts,and traditional machining methods cannot meet their performance requirements.When the gear shaft is working in the transmission system,the load situation is complicated.Therefore,the gear shaft should have good mechanical properties such as impact resistance,wear resistance,high strength and hardness,and good internal organization performance to ensure that it can work fine under high load.However,its metal flow situation during the hot die forging process is more complicated.Defects such as folding and insufficient filling may occur during forming,and the corresponding molds will have severe wear and cracks.In this paper,the gear shaft used on new energy vehicles is taken as the research object,and hot die forging is used to process it.Combined with the plastic forming principle and finite element simulation,the gear shaft forging process is simulated and analyzed.During the research,the following tasks were mainly completed:(1)According to the gear shaft product provided by the enterprise,by consulting relevant standards,forging theoretical design reference books and actual production needs of the enterprise to design the forging drawing of the gear shaft,the related process die drawing,to determine the initial blanking size of the forging,to calculate the main the forming force of the process and choose the equipment of appropriate tonnage.(2)By using to build 3D modeling of each process mold and by importing the corresponding mold into Deform-3D for numerical simulation,and analysing the flow law during the gear shaft hot die forging.During the prediction of the preform flow process,it was found that when the material fills the cavity of the rod part,the filling speed of the two sides is greater than the center,which causes shrinkage holes in the metal confluence and then folding defects.Therefore,by changing the size and thickness of the flange of the preformed forging to add a material holding structure at the center of the flange,the purpose of optimizing the mold structure is achieved,the flow of metal is improved,and the occurrence of folding defects is avoided.(3)Combined with the optimized preform mold,studying the metal flow law and speed field distribution law in different processes of the gear shaft,temperature field distribution,stress and strain field distribution during blank forming,preform mold wear analysis and analysis of mold forming load in four processes.(4)Aiming at the wear of the preform mold,the response surface method and finite element method are used to simulate the forming process under different parameter combinations.Based on the simulation results,a response surface model is established and the response surface and variance are analyzed.Considering the response model and production conditions comprehensively,a set of the best parameters is optimized and simulation tests are performed to verify its feasibility.(5)Finally,through the temperature test,hardness test,impact performance test,tensile test,metallographic structure test and other tests on the forgings,it is found that the test results can verify the reliability of the numerical simulation process and the results,and meet the relevant technical requirements.The production process has some guiding significance.