Study On Quality Control Of Multi-procedure Impact Forging Forming Of Asymmetric Multi-wedge Belt Pulley

Multi-wedge wheel with asymmetric structure is an important transmission part ofautomobile engine.Under the background of the development of automobile lightweight,the parts are required to have good mechanical properties and service life.The traditional casting and tailor-welding forming of such transmission parts have the disadvantages of low material utilization rate,high equipment input and poor mechanical properties,so it is difficult to meet the requirements of asymmetric multi-wedge wheel.The forming quality of the asymmetric multi-wedge wheel preform is related to the forming effect of the whole multi-wedge wheel.Therefore,in this paper,a multi-pass punching forging process is proposed for a multi-wedge wheel preform with asymmetric structure.This paper analyzes the structure size of the asymmetric multi-wedge wheel pre-blank,calculates and determines the reasonable size of the slab and the punch and die structure of each pass,and determines the reasonable forming conditions and technological parameters,so as to work out the optimal forming process scheme of the parts.The finite element model of multi-pass punching forging was established and simulated by using the finite element analysis software DRFORM.According to the simulation results,the rheological behavior of materials,the stress-strain distribution state and the forming load in the punching forging process were analyzed.Based on the simulation results,by adjusting the punch feed speed and friction coefficient,it is found that smaller punch feed speed and friction coefficient are beneficial to ensure the uniformity of deformation,reduce the forming load and improve the forming quality.In addition,the influences of the punch fillet radius ratio r _P/t₀,the die fillet radius ratio r_d/t₀,the punch feed speed and friction coefficient on the forming quality of the first two passes were analyzed.It is found that when the value of r_p/t₀ is between 1.6 and 2.4 and the value of r_d/t₀ is between 2 and 3,the minimum wall thickness of the workpiece will reach a peak value,and the region where the wall thickness fluctuates greatly at this time is also the minimum,that is,the forming quality is the best,which provides guidance for the actual production.Based on the grey system theory,the ratio of the punch feed speed,friction coefficient and the punch fillet radius to the slab thickness is taken as the independent variables,the forming load and the slab thinning degree are taken as the objective function,and the correlation coefficient and correlation degree are calculated.The optimal combination of multi-objective optimized forming process parameters was obtained,namely,the feed speed of the punch was 150 mm/s,the friction coefficient was 0.12,and the ratio of the fillet radius of the punch to the thickness of the slab was 2.4.Combined with the optimization results,a multi-pass punching forging test was carried out on a 200-ton RZU200HF hydraulic press with asymmetric structure and a qualified sample was produced to meet the design requirements of the parts.