Numerical Simulation And Precision Mold Cavity Design Method Research Of Straight Bevel Gear Precision Forging Technology

The precision forging forming technology is a net or near net shape forming technology which can get forge pieces with intricately shape, high precision and nearly non margin. As it can improve the quality of forge pieces, reduce subsequent machining, decrease manufacturing cost, recently, it has raised universal high attention. With the increasing of car production and competition in auto parts enterprises, utilizing the precision forging forming technology to produce gear parts shows superiorities in costs and properties than traditional machining. To level up the forming precision and simplify the forging processing have became the main routes to make further efforts to lower the cost. The tooth profile cavity size of mold has direct influences on the accuracy of final precision forging gear tooth profile. Thus there are significant theoretical importance and practical value in researching the precise design method of bevel gear precision forging mold cavity, enhancing the design level of bevel gear forming mold and promoting the further development of gear precision forging technology and its advantages.Firstly, this paper determined the forming technology and the technological parameters of closed-die cold precision forging, utilized UG software to finish the straight bevel gear parts drawing, forging drawing and the3D mold modeling. According to the orthogonal experimental design, the paper made a four factors and three levels orthogonal table, then used DEFORM-3D software to perform numerical simulations on the forging processing. Based on the forming load, the thesis got the influence degree of four mainly effective factors (punching recess thickness, downside blind hole height, terrace die movement velocity, friction coefficient) on the straight bevel gear closed-die precision forging forming quality and the influence rule on forming load, the paper also determined the optimal processing parameters, detail analysed the velocity field, strain, stress, forming load and filling ability, under the optimal processing parameters’ circumstance. As the forming load of closed-die forging is relatively high, internal pressure of workpiece must lead to large elastic deformation in downside die cavity, at the same time, the gear forge piece is especially prone to have elastic recovery after depanning, these two factors have severe negative effects on straight bevel gear forming quality. In this paper, the elastic deformation data of die and workpiece was got through DEFORM-3D software analysis under the optimal processing parameters’ circumstance of the precision forging. And the overall trend was that the downside die expanded through the forging processing and the forge piece would increase its size after depanning. At last, utilize the MATLAB software to reverse add the die elastic deformation data and forge piece elastic recovery data to compensate the ideal mold cavity design, therefore, the thesis finish the precision forging die cavity design of straight bevel gear closed-die cold precision forging forming processing.