Extrusion Forming Technology And Numerical Simulation In Straight-tooth Bevel Gear

As the industry developed rapidly, gear was required strictly in manufacturing and machining. The gear which machined by cold extrusion method has the advantages of good mechanical properties and high production efficiency and saving materials, compared with which machined by traditional process methods. Based on the rapid development of our native manufacturing technology and the project requirement of the "small module gear precision forming technology" that is taken by enterprise, this paper mainly studies on the cold extrusion technique and forming rule of the small module straight-tooth bevel gear.Through reading the national and international literature, the author knew the status of gear forming technology and precision forming technology, analyzed the advantages of precision forming method, compared with traditional process method; introduced the development and status of cold extrusion technology, and some problems in cold extrusion technology; expatiate the importance of numerical simulation, especially the use in plastic forming.Aimed at the cold extrusion technology of gear, introduced the forming principle of cold extruding gear, the process features of cold extrusion method, the law of metal flowing and various influence factors in the forming process, listed the eliminate method of these factor; made an analysis in extruding part's material, shape, dimension accuracy and surface quality, blank size and surface treatment, lubrication and other aspects; designed the mould. Calculated and listed the gear's every technique parameter, modeling the part and mould using "PRO/E" software, obtained the part and mould, which provided reference for forming technology finite-element numerical simulation and analyze.Based on the rigid-plastic finite-element theories, building the spur bevel gear's finite-element analyze model of extruding forming. Based on finite-element analyze software DEFORM-3D, using the three-dimensional rigid-plastic finite-element method simulated the spur bevel gear's extrusion forming process, analyzed and compared the results of forming between two different shape blank. Obtained the metal's flowing status during forming process, the law of effective stress and strain distribution. The gear's forming process, effective stress-strain distribution and nodes velocity distribution were figured out directly by graphics and curves, obtained the law of metal extrusion deformation.Combining the law of gear forming, discussed the mostly failure form of female die, and also analyzed the stress of die cavity, obtained the stress distribution curves. Stress changes were in the range of die material allowed, proving that die structure was available.