The Technology Research On Cold Extrusion Deformation For Sleeve Parts Based On Finite Element Simulation

With the advancement of science and technology, the research and development of new materials for die steel, the replacement of extrusion equipment and the increasing rationalization of mold design, the cold extrusion processing has become an important means of machining and has been rapidly developed and widely used in manufacturing industry. From the current researches, we know what scholars in and abroad have focused on are applying cold extrusion technology to the external construction of parts, but the application to the internal structure of parts is relatively small. As a result, it is of great significance to research the application to the internal structure of parts. The main research contents of this paper are as following:1,The traditional manufacturing manner of sleeve parts which have internal step is achieved by machining and cutting out excess metal material using bar or pipe blanks. This method wastes a lot of raw materials and processing time. To solve this problem, this paper presented a method. In the new way, the parts can be got by cold extrusion directly by using a kind of tubing whose size is close to the size of these pats and cutting can be avoided.2,The important guarantee for the success of cold extrusion is the mold with reasonable structure. According to the simulation, the face sharp of the male mould was constantly modified in this paper and the matching mode between male mould and support mould was adjusted in order to form the material in pre-deformation way. For the sake of easily disassembly after the extrusion, the support mould was designed with quadrate lifting lug. Furthermore, a set of fasteners was proposed to fixe the work pieces.3,The finite element software DEFORM-3D was used to simulate the cold extruding forming process of the sleeve parts with internal step. The simulation results show that the metal flow and the stress and strain accord with the general rules of cold extrusion in our cold extrusion process, and calculate value of the unit extrusion pressure required for formation meet the allowable range of extrusion pressure., Suitable parameters for our cold extrusion process were obtained via simulation. The analysis indicates that once much smaller extrusion deformation will result in incomplete forming and burr, and that much higher extrusion speed and much bigger friction factor will make stress concentration of cold extrusion and burr will occur on the surface of work pieces.