Research And Application Of Through-type Cold-extrusion Method For Spline Spindle Of Truck Transmission

In recent years,with the rapid development of the automobile industry in China and other countries,the demand for spline shafts what is the key parts of automobile transmissions,has also increased.For truck transmission spline shafts,traditional cutting processing is currently mainly used in China,but the production efficiency is relatively low.The cold-extrusion forming process of truck transmission spline shaft studied in this subject is currently facing the main problem: the blank of truck transmission spline shaft will bear a large forming force during the process of cold-extrusion,and it is prone to upsetting instability,bending deformation and other forming defects.Therefore,how to effectively reduce the bending deformation and reduce the forming force during the cold-extrusion process of the spline shaft is the key problem to be solved in the research of cold-extrusion process.At the same time,for such kind of long spline spindle,if the traditional open-die cold-extrusion is adopted,the requirements for the opening height of the equipment will be higher,and the production efficiency and material utilization rate are relatively low.Therefore,it is necessary to propose a new cold-extrusion process scheme for the spline shaft of the truck transmission.This subject takes the truck transmission spline spindle that a company intends to develop as the object of research,analyzes the traditional open-die cold-extrusion forming scheme of the spline shaft,and develops the through-type cold-extrusion forming scheme according to the structural characteristics of this type of spline spindle;Combined with the analysis of the metal flow of the spline shaft in the cold-extrusion process and the upper bound limit method,the main factors affecting the forming quality of parts and forming load of the spline shaft and the metal flow characteristics during the spline forming process are obtained;At the same time,the finite element software is used for the simulation the forming process.According to the numerical simulation results,we analyzes the influence of the process parameters on the bending deformation and forming load during the spline shaft through cold extrusion process;And the orthogonal test method has be used to perform the process.After the orthogonal test,the parameters will be optimized and the best combination of process parameters will be determined.Finally,according to the results after parameter optimization,a process test was carried out on the through-type cold-extrusion forming process of the spline spindle of the truck transmission,and the size of the extruded part was tested.The process test results show that the forming quality and dimensional accuracy of the spline main shaft extrusion of truck transmission can meet the design requirements after the through-type cold-extrusion is performed with the best process parameter combination.