Research On Ball Spinning Flanging Technology And Design Of Special Equipment

The flange hole is a common structure in the rocket fuel tank and is currently processed mainly through stamping.Due to material and process limitations,the use of stamping flanging process to achieve a single pass small flanging coefficient flanging is likely to occur border cracking problem,the need for multi-pass stamping flanging or other technology can be achieved,the process is more complex.Ball spinning is a incremental forming process,can improve the sheet metal forming limit,the workpiece surface roughness is good,the method is simple.In order to improve the plasticity,forming limit and flanging coefficient of aluminum alloy,this study attempts to use the ball spinning process instead of the traditional rocket fuel box flanging hole processing technology,and the ball spinning forming process to explore the study.Firstly,the forming process of the round hole of the ball spinning is analyzed theoretically,and the analytical model of the ball spinning pressure is established.According to the characteristics of the forming area,the contact deformation between the ball and the plate is divided into the thinning deformation zone and the flanging deformation zone.The contact stress of the two regions is calculated by the projection method,and the contact stress of the two regions is calculated,on this basis,the force of the ball spinning is precisely calculated.Besides,the influence of each process parameter is briefly analyzed,and the selection principle of process parameters is preliminarily determined.Secondly,a finite element model of ball screw hole was established.The simulation results are compared with the results of the analytical model,and the accuracy of the spin pressure analysis model is verified.The effects of feed rate,ball diameter and thinning rate on the force of the ball spinning,stress and strain were analyzed by simulating under different process parameters.Which provides a basis for rational selection and optimization of process parameters.Thirdly,the data generation of the multi-parameter spatial sample data was carried out by using the optimal Latin supercubic test design method.The RBF radial basis neuralnetwork approximation model is constructed.The multi-objective genetic algorithm NSGA-II is used to optimize the approximate model,and the Pareto optimal solution set is obtained.Finally,the feeding force and the motor power required for the pitching of the balls are determined.The basic structure of spinning equipment such as spinning head,feed device and rack is designed.Static analysis and modal analysis of the structure are carried out.For the follow-up research done pave the way.