Study On The Forming Method And Optimization Of Multi-Pass Die-less Spinning

As a kind of plastic forming process,spinning is widely used in processing complex curved manufacturing process of high precision,light weight,and high stability.At present the more widely used is the general spinning technology,as a focus of mandreal spinning,but as the high-cost and the manufacturing of mandreal of complex curved parts,there are some challenges with the mandrel spinning.Die-less spinning,as a non-mandrel continuous local metal plastic forming technology,embodies many advantages.The study on the forming method of multi-pass positive return shows that it can effectively control the wall thickness reduction of spinning parts,however,this method is less involved in the multi-pass die-less spinning of complex curved parts.In view of wide range of applications of this approach in the general spinning multi-pass forming,in this paper,the forming method is applied to die-less spinning,its forming precision needs to be further studied.In this paper,some research on this issue has been carried out,the research contents include:Point out the research background of this paper,then summarize the current situation of forming method and track shape of common spinning and die-less spinning.Put forward The problem of accuracy of different forming methods of die-less spinning and optimization of forming method.And introduce the main contents of the study on the forming method and optimization of multi die-less spinning.Established the geometrical model and simulation model of two forming methods of multi-pass die-less spinning.In view of the conclusion of the multi-pass of general spinning,both of the positive and return curves of segmented forming use the involute trajectory that maintains a better wall thickness.Then,deduce the formation equation of involute,and introduce the method of design the segmented trajectory in detail.Design the segmented trajectories of different target curves,then build the finite element simulation model of the dynamic simulation platform based on ANSYS/LS-DYNA,and validates the effectiveness of the simulation mode.Then discussion the forming precision of different forming methods of different target profile curves with experiment method.The experimental platform used in this paper is a multi-functional composite plate spinning machine designed independently by the project team,on the basis of the equipment and experimental conditions,then design the experimental scheme and carry out the spinning experiment,then measure the thickness with an ultrasonic thickness gauge and measure the profile of the formed part with a profile measuring instrument.Then analyze the results,and obtain the best forming method for different target profile.Propose the method of incremental-segmentation forming of complex curve.Then design the trajectory of three kinds of incremental-segmentation forming method.Design the experimental scheme and verified experimentally for the convex-concave curve and the concavo-convex curve.And obtain the optimal incremental-segmentation method of wall thickness effect and shape effect.Carry out the optimization of forming method and the improvement of forming quality based on feed ratio optimization.In order to improve the surface quality,improve the forming accuracy,come up with the method combination of final-pass-gradual method and the former-pass-progressive,and the method of mixed forming of progressive Segmentation and progressive forming.And use the method of variable feed to optimize the forming quality.