The Mechanism And Experimental Research Of Two Points Semmetry Incremental Forming

Sheet metal dieless incremental forming is a method through local accumulatingdeformation to achieve the overall forming. It has overcome the characteristics of a die, whichis long manufacturing cycle, high cost, lack of flexibility and so on, and particularly suited tonew product research and development and the production of varied samples and small batch.Incremental multi-point forming technology is a new type of sheet metal dieless formingtechnology, which combined with single point incremental forming technology and MPFtechnology. This technology not only makes full use of the advantages of high precision fromsingle point incremental forming and high efficiency from MPF, but also improves theforming efficiency and quality of workpieces.Two-point incremental forming technology is aform of incremental multi-point forming technology. Through the experimental research oftwo-point incremental forming, the result was used to carry on comparison analysis withsingle point incremental forming.Main research results of this paper:(1)For the characteristics of the "hierarchical processing" of sheet metal incrementalforming, stress analysis was carried out on the general forming force in incremental formingprocess, and it was broken into horizontal and longitudinal force later. According to differentstrains which was produced in the process of each layer and reasonable assumptions andsimplification, the expression of horizontal and longitudinal force was deduced when layer1and layer2(the rest of the layers were the same to the second layer) was processed, whichwas called the expression of local forming force in the incremental forming and was verifiedby experiments.(2)On the basis of having established model of local forming force, stress analysis wascarried out on the rotary parts which was processed by two tool heads distributedsymmetricaly, then the whole dynamic balance equation was listed and the expression ofoverall forming force was deduced. At the same time, the numerical solution was carried out,and the graph which reflected relationship between forming force and the time was drawn byMatlab. In the end, the processing characteristics were found out in the aspect of formingforce, stress and strain between two point forming and single point forming.(3)Analysis and validation of experiment. The auther used two-point forming tooldistributed symmetrically to manufacture rotative box parts on the CNC lathe and detected the forming force and compared with the forming force model which was deduced, and verifiedthe correctness of the model. According to comparing with single point incremental forming,forming force in two-point incremental forming processing was less than single pointincremental forming, and that two-point incremental forming can effectively improve theforming quality of the boundary and the surface quality in the forming technology.