Study On The Simulation Of Upsetting Process And Optimization Of Technology Of Spline Hub Of Heavy Truck

The spline hub,also known as sliding sleeve,is an important part of the drive shaft assembly of heavy truck,which is connected with the universal joint fork and shaft fork.It bears complex alternating stress,and its quality affects vehicle driving safety directly.The traditional upsetting process of spline hub is poor in quality and the die life is low,so it is difficult to meet the development needs of the heavy truck market.In this paper,the upsetting process of spline hub was studied mainly from the optimization design of the spline hub upsettting die,the numerical simulation of forming process,the influence of process parameters and optimization.In this paper,three kinds of open upsetting die were put forward by analyzing the forging process of spline hub.The 3D model of the open upsetting process of spline hub was established by Creo software.Then two schemes of separable die structure were simulated by using the finite element method.The important parameters such as effective stress,effective strain,forging damage and forging load were obtained during the forming process.Based on the comparative analysis of two separable die structures,the separable die insert whose parting position is 5mm from the front surface was selected.On the basis of determining the die structure,in order to reduce the forming load and obtain the better forming quality,the influences of different process parameters on forming quality were analyzed and studied in the process of simulation.With the increase of initial billet temperature,the forming load decreases obviously,but the maximum values of effective stress,effective strain and forging damage decrease firstly and then increase gradually,and the effective stress distribution is more uniform,and the deformation uniformity is enhanced,and when the initial billet temperature is at 1200?,the front end of spline hub will be folded;With the increase of die temperature,the forming load does not change obviously,but the maximum value of forming load decreases gradually,and the maximum values of effective stress,effective strain and forging damage decrease gradually;With the increase of friction coefficient,the forming load changes obviously at the later stage of upsetting process and the maximum value increases gradually,and the maximum values of effective stress,effective strain and forging damage increase gradually.The influence of process parameters on maximum forming load and forging damage were obtained by the orthogonal test.The order of forgings damage is the friction coefficient,initial billet temperature and die temperature;The order of forming load is the initial billet temperature,friction coefficient and die temperature;Linear weighted analysis of multiple targets was carried out to get the combination of process parameters with better forming quality.Finally,the production verification of the optimal die structure and combination of optimal process parameters showed that: The open upsetting die structure with separable die insert whose parting position is 5mm from front surface can solve the existing problems in the traditional upsetting process of spline hub effectively.The experimental and simulation results of the combination of optimal process parameters are in good agreement with each other,and the correctness of the finite element analysis is verified.After optimizing the process,the forged state grain of spline hub is refined obviously,and the die life is improved.The finite element simulation and orthogonal experimental method were applied to the optimization of the upsetting process of spline hub in this paper,which optimized the final forging die structure and upsetting process parameters of spline hub,and improved the die life and forming quality.The research in this paper can not only provide theoretical suppoort for the actual upsetting process of spline hub,but also provide theoretical suppoort for the upsetting process and optimization of other similar forgings.