Optimization Of Clutch Block Cold Extrusion Process And Combine Die Based On Finite Element Method

Cold extrusion is a near net shape technology, it is their metal forming at certaintemperatures that gives cold extrusion their main advantage over many other machiningprocesses, such as the streamline uniformity, high precision and good surface quality,excellence mechanical performance, and high productivity. Because the superiority of coldextrusion, the clutch block is produced by optimization of multi-phases cold extrusionprocesses which combined the technological experience with numerical simulationtechniques. In this paper, there are discussed two things.1. Development and optimization of cold extrusion processes. The material, whichused in the clutch block, is GB-15CrMo, and the geometry of clutch block is complex, it iscontained three parts: the two sidestep, the ring groove and the inside herringbone teeth.How to arrange the forming of three parts is significant and the cold extrusion process ofclutch block is determined by that. However, the finite element method is the best choice inthis metal forming. And the software package DEFORM2D&3D is introduced in thispaper, with this software package, we have analyzed the root cause for the top die crackand establishing an appropriate solution of quality extrusion process. What’s more,numerical simulation for every case also discussed in this study, through analyzing theparameters in every simulation, finally, the optimal cold extrusion process of clutch blockis carried out, and verification by experiment in company. The final extrusion process is asfollow: the two sidesteps have been forward extruded firstly; second, the ring and theinside herringbone teeth are formed by combined extrusion, during the second phase, themandrel in the extrusion die should be removed.2. Optimization of shrink fit magnitude and diameter ratio. The extrusion die withtwo shrink rings are modeled based on the finite element methods, one of the key problemsis contact problems in the design of extrusion die with two shrink rings, however, thecontact problem is discussed with the finite element analysis in this study, the force among the shrink rings is transform from one to another and die insert is significant. During the optimization of shrink fit magnitude and diameter ratio, uniform design, which is statistical theory of mathematical model, is introduced. The two-dimensional and three-dimensional problems in the finite element method is carried out, the result shows that the shrink fit magnitude in the die insert and middle shrink ring should be larger than the magnitude between the middle shrink ring and outer shrink ring, and1.1times to2.4times will be better in designing. The best extrusion diameter ratio is4.6, and the diameter of die insert and the two shrink rings are066.2mm,(?)110.0mm,(?)207mm, respectively, and the shrink fit magnitude is0.4mm and0.35mm, respectively.