Reserch On Precise Forming Technology And Die For Vehicle Sleeve Gear With Spline

The vehicle sleeve gear with spline which this project researched is the key part ofreverse gear institution; the part contains two parts with a spur gears and rectangular spline.Which is also mass-produced parts. Its traditional chip processing methods material haslow utilization and productivity and high production costs. The part strength and servicelife of metal are reduced because of the cut flow lines, with the increasing requirements ofthe vehicle parts quality of the vehicle industry, chip processing the forming process is notsuitable for the production of the parts. The cold extrusion is a less/cutting process, anadvanced technology to forming the vehicle sleeve gear, but the toothed sufficientdissatisfaction and spline upsetting the defects easily generate in the cold extrusion ofvehicle sleeve gear. So analysis the cold extrusion process and parameters helps to avoidthe generation of various defects in the production, improve the quality of the mold design,shorten the cycle of the mold design, mold design cost and improve the parts coldextrusion quality has important practical significance.The cold extrusion material model of20CrMnTi was firstly established onDEFORM-3D to improve simulation accuracy, which improved the accuracy of thenumerical simulation compared with the commonly used approximation of alternativematerials.Through the analysis of the cold extrusion forming process of the vehicle sleeve gearthe processing was divided into two working steps: one was to forming the wheel gear andthe flange plate, another one was to forming the spline. In the first work step, forming thewheel gear and the flange plate of sleeve gear with spline, due to the powerful formingforce, the teeth discontent filling and easy to grow injury and other defects with the firstscenario, we proposed the second project. The second project mainly increases a bossconstruction in the upper mold and a ladder flash to the structure of the die part combinesthe law of minimum resistance and control the flow of forming techniques (FCF). Bothstructure is benefit to billet flow to the gear tooth parts; and the ladder flash increases theflowing resistance of the billet to the flash, which promotes billet flow to the gear toothparts. In the processing of forming spline part, the spline often grow the defects ofupsetting into the die mouth, the end socket teeth of spline discontent filling and tooth rootcracking. So we analyzed the parameters that affect these defects firstly, then analyzed thevarious factors by the finite element simulation combined with the orthogonal experimental to make sure each factor of the influence to spline.The physics mould was designed on the basis of the numerical simulation, andobtained sleeve gear spline with filling full tooth shape, no defects and high-precision,which shows that the numerical simulation has an important role in guiding the practiceproduction. The microstructure of the sleeve gear spline became denser, and the hardnesswas also improved after forming, which showed that cold extrusion technology canimprove the mechanical properties of the parts, and the technology is an advancedprocessing method to forming the sleeve gear spline.