Study On Ball Spinning Of Tubular Parts With Longitudinal Inner Rib

High-precision and high-intension cylindrical workpieces are widely applied in industrial production, especially in highly technical fields, such as aeronautics, aerospace and weapon industries. Power-spinning is the most effective method in obtaining the cylindrical workpieces. With rapid development of aeronautics, aerospace and weapon industries, some complicated and sophisticated spinned parts are required urgently. Thin-walled tubular parts with longitudinal inner rib can satisfy the demand. Ball spinning plays a key role in forming of thin-walled tubular parts as a new spinning process. In process of manufacture, many process parameters affect the qualities of the spinned parts, engineers have to establish process parameters by trial-and-error approach, which lead to poor economy.Based on the deep analysis of finite element method(FEM) and process characteristics of ball spinning of thin-walled tubular parts with longitudinal inner rib, the boundary condition and the determination of load type are disposed effectively, and the blank and mandrel, ball are discreted respectively, the 3D FEM model of the tube parts backward spinning, which fit well with the process of tube spinning, is founded through FEA software.Through simulation, the flow rules of metal are obtained during the steady deformation of ball spinning, it coincides with results of experiment. Using the rules, drawbacks which power spinning is simpled as plane problem in simulating are pointed out. The distribution draws of stress and strain are obtained in steady forming, the results can well interpret forming mechanism and reasons of deflection of piling, enlarging, reducing of diameter, etc.Different technological parameters of ball spinning are simulated. The rules which various parameters influence spinning force and equivalent stress are obtained and its provide theoretical evidence for choosing the optimal parameters.Several quality defect are studied when thin-walled tubular parts with longitudinal inner rib is spinning, phenomenon of oval port, superficial peel-off and pilling are interpreted. In the end, through adjusting of parameters, tubular parts with qualified inner rib and appropriate matching parameters are achieved.