The Warm-cold-precision Forging Technology And Mechanism For Tripod Universal Joint Housing

warm-cold-precision forging technology combines the advantages of different precision forging technology,what’s more,it can improve the work efficiency and save the manufacturing cost,which will be the developmental trend of precision plastic forming technology in the future.This paper took tripod universal joint housing as the research object,and created the parameter forming process and mold design rule for it.Besides,the paper studied the metal flow line through numerical analysis technology,the wear mechanism and prolonging life technology for warm backward extrusion through production practices.The main research contents and conclusions are as follows:According to the structure and size characteristics of the part,the paper created the process and mold design rules based on deformation quantity,size distribution technology and compensate technology by parameter method.The whole forming process and metal flow line of tripod universal joint housing were analyzed by numerical analysis software.In addition,the paper studied the effects of forward extrusion technique,punch shape and size of backward extrusion,friction and extrusion speed on metal flow line.Finally,the paper optimized the metal flow line and given the best forging scheme.Aiming at the defect of quick wearing and short service life of H13 warm extrusion punch,the effects of mould preheat temperature,mould surface hardness and friction on wear rate for warm backward extrusion mould were studied,moreover,the main failure modes and mechanism of warm backward extrusion mould were obtained.Furthermore,three method for prolonging the mould serve life was put forward.Finally,the paper practiced the production experiment and compared the mould life for different prolonging mold life methods.The results showed that the metal flow line can be optimized by good forging process,better mould design and strict process control parameters.In addition,triangular punch had the best guidance for metal flow line among trapezoidal punch and flat punch.In the premise of the channel size,the greater the bottom inclined angle of triangular punch,the top arc radius and bottom diameter of guidance cone,the better the metal flow.The bigger the friction,the worse the metal flow line,and the extrusion speed had little effect on the metal flow line.Besides,the mould surface hardness had the biggest effect for mould wear rate among mould preheat temperature and friction.Compared with the non-laser shock processing mould,wear resistance of the mould after laser shock processing was promoted and the surface hardness increased about 12.5%,as well as the first service life was increased about 60.4%.