The Study Of Hot Extrusion Technology For Internal Spline Shaft

With the rapid development of motorcycle, automobile, aerospace and other manufacturing industries, the demand for spline shaft is increasing, and the mechanical properties of the spline shaft are increasingly high requirements.Internal spline shaft is a kind of complex structure, which has the characteristics of compact structure, high bearing capacity and good mechanical properties, so it has wide practical demand and application space. Actually, manufacture such internal spline shaft with ladders, mechanical machining methods exists large consumables, low production efficiency and poor mechanical properties defects;Cold extrusion process has large deformation resistance, so it requires large equipment tonnage, which is not economic;Hot extrusion process is a high efficiently, low consumption, simple equipment requirements and high mechanical properties processing method. Therefore, hot extrusion process for internal spline shaft parts has important theoretical significance in the actual production.In this paper, through the analysis of the material and the shape and size of internal spline shaft parts, the drawing of hot extrusion parts was designed;According to the structural characteristics and process requirements of the hot extrusion parts, three kinds of hot extrusion forming scheme were proposed,respectively from the material utilization rate and deformation degree analyzed the contrast, finally, using of hollow billet with hot extrusion process to form internal spline shaft was determined; Established the mechanical model of hollow billet forming internal spline shaft in the hot extrusion process, and with the use of principal stress method to calculate the extrusion force in the process of internal spline shaft forming; In depth analysis of the hot extrusion process,the hot extrusion die of the spline shaft was designed, and the die and billet were modeled by UG6.0; By using DEFORM-3D software numerical simulated the hot extrusion process of internal spline shaft, and the forming process of extrusion pressure, stress and strain field distribution, velocity field distribution and temperature distribution of billet were analyzed, which proved thefeasibility of the process; By controlling variables method, analyzed comparatively the billet heating temperature, preheating temperature of die,friction coefficient and cone angle of the concave die five parameters to the influence of the extrusion pressure in the forming process, eventually determined a set of reasonable parameters: the billet heating temperature is1100?~1200?, the die preheating temperature is 300?, the extrusion speed is10mm/s, the friction coefficient is 0.3, the concave die cone angle is 55°.