Research On Bending Deformation Of Spline Shaft In Cold Extrusion

Spline shaft is the common parts in the power-transmission device of automobile andmotorcycle. Now this kind of parts mostly is formed by cold-extrusion, and formingquality requirements are increasing. Because of the influence of many factors in theprocess of cold forging, extrusion-parts easily cause bending deformation and can notreach the request of accuracy. So, It is a burning question that how to decrease bendingdeformation in cold-extrusion of spline shaft.The underlying reason for result in bending deformation of spline shaft isinhomogeneous flow of metal. So this paper analyzed the metal flow and the admissiblevelocity fields in the forming process of spline shaft, determined gave coaxality of dies、bearing length、concave die semiangle、friction coefficient and billet diameter，which wereimportant parameters influencing the bending deformation of spline shaft，and it had theguiding significance for parameter selection in numerical simulation.In accordance with the cold-extrusion process of CG125motorcycle’s main spindle,using finite element numerical simulation software DEFORM-3D, the forming process wassimulated with changing different parameters, the regulation of the bending deformationwas obtained, and the optimizing value of each parameter was given.Base on the result of the numerical simulation, the cold-extrusion technology test forCG125motorcycle’s main spindle was carried out, the test showed that the optimizingparameters could significantly decrease bending deformation of spline shaft, the radicalrun-out of specimen matched the designing requirement of extrusion part. And it had acertain guiding significance for actual production.