Computer Simulation Of High Weld Neck Flange Precision Ring Rolling Process Optimization

Rings are widely used in petrolic industry, metallurgy, shipbuilding, aviation, armament industry. At present, the traditional manufacturing technique of rings with the die method, has many disadvantages, such as material-wasted, low productivity and high production cost. With the development of market requirements for high quality and low cost of ring, the traditional manufacturing technique will not meet all such demands. The existing tradition method of manufacturing ring should be improved. But the relative studies about ring rolling have not been expanded completely. This is limited by several conditions, such as the research of complicated deformation law with many coupling factors and the development of advanced facility without the help of computer. The development of peripheral techniques such as FEM and CNC make the net-shape possible in ring rolling. So the research of precision ring rolling is becoming focused on.The main contents of this paper include:(1) With the method of finite element numerical simulation, forming process of big caliber flange (JB/T4700-2000) was analyzed. After studying the relationship between the immobility and the shape of primary roller, the optimizing primary roller which change the deformation law of blank in its entrance was brought forward. The immobility, due to local aberrance of blank which can not match the shape of primary roller was avoided.(2) After analyzed the principle of declination and its effect on the precision of work pieces, frictional torsion is regarded as one of the reasons that caused declination. Considering the disadvantages of present project, the author designed two advanced projects. They are compared with FEM in the deformation process, the method of blank making, the working situation of spindle and etc. Finally, the author gives the better project of both.(3) The relationship between the filling order of blank and the speed of spindle and their influence on the precision of work pieces were studied. The rational values within a scope of axial clearance and radial clearance weredefined with the method of simulation. Otherwise, how to reach agreement among the speed of the spindle, axial allowanceAh and the growing speed of blank diameter is a emphases of this thesis. At last the author put forward a new minimum remnant method which can optimize the speed of spindle for better growing speed of blank diameter and high accurate ring rolling work pieces...