Forming Technology Optimization And Precision Mold Cavity Design Method Of The Twin Cone Roll Forging Driven Spiral Bevel Gear

Spiral bevel gear is an important mechanical component,which is widely used in the automotive,tractors,engineering vehicles,military vehicles and other mobile machines' axle.For a long time,the processing method of spiral bevel gear is cutting process which not only has low material utilization rate,but also has low efficiency,high cost and environmental pollution.The twin cone roll forging driven spiral bevel gear is a new technology of plastic forming spiral bevel gears,which has the advantages of energy saving,material saving,high efficiency and so on,compared with the traditional cutting method.But the twin cone roll forging forming technology of spiral bevel gear has the gear filling difficulty,short service life of the die mold cavity,the accuracy is not high,which seriously hampered the promotion and application of this technology.Firstly,the 3D model of the spiral bevel gears was established by utilizing the 3D software Solidworks,and the 3D model of spiral bevel gear forging and die forging was designed at the same time.The law of tooth profile was obtained,and the forming mechanism of double cone roller rolling was revealed by simulating the forming process of spiral bevel gear in DEFORM-3D;The law of tooth filling and the elastic recovery of the spiral bevel gear forging were obtained by studying the elastic recovery behavior of the helical bevel gears.The results showed: the tooth height of spiral bevel gear forging was increased gradually with the increasing of rolling temperature;Spiral bevel gear forgings tooth profile concave and convex elastic resilience of deviation from the heel to the small end gradually decreased,and the top of the tooth elastic recovery was minimal,the root of the elastic recovery was the largest.Secondly,the stress of cavity tooth root was analyzed by using the method of point tracking and analysis of unbalanced stress,and the stress distribution characteristics of the cavity tooth root were obtained,and the unbalanced stress in different segments of cavity tooth root was calculated and analyzed,and the middle part of the root cavity prone to plastic deformation or rupture was found.The research results can provide reference for the long life design of the die of twin cone roll forging driven spiral bevel gear.Again,the paper made a three factors and three levels orthogonal experimental design selecting the rolling temperature,the feed rate of the lower die,the friction coefficient in the forming process as the experimental factors and selecting the equivalent stress of the model cavity and the tooth height of forming gear tooth as the experimental index to process the optimization of forming process of spiral bevel gear with double cone roller.The results showed that the influence degree of the process parameters on the die stress and the gear forging height was the order of the forming temperature > the feed rate of the mold cavity > the friction factor.Lastly,the mold cavity of the twin cone rolling spiral bevel gear was precisely designed by using the reverse stack correction method,which used the Matlab software for data processing,and the elastic deformation of the cavity and the elastic recovery of the driven spiral bevel gear forgings were inverted to the mold cavity.