Automatic Layout And Addendum For NC Incremental Forming

For a long time, the traditional sheet metal forming process, such as stamping, needs to designand manufacture molds. But the time of mold design is long, the cost is high, the lack of flexibility,and when products change all these molds will needed to design and manufacture again. However,with the requirements of customs changing, the demands of single piece and small amount of sheetmetal products is growing, the traditional sheet metal forming process is difficult to fully meet theserequirements. In the1990s, to meet the demands, Japanese scholars put forward NC incremental sheetmetal forming technology. This technology is using Layering Manufacturing. The cutter of NCmilling machine will be changed by tool head. The part will be formed step by step under the controlof CNC system according to the desired trajectory movement. This technology can make verycomplex sheet metal parts without molds. But, the thinning rate of the incremental forming parts isvery high. Some cases can result in local fracture. Therefore, how to predict the occurrence of ruptureand put forward the corresponding method to avoid the fracture is of great significance for thedevelopment of this technology.In the former research achievements, the people made in-depth study on forming limit of theincremental forming technology. But, in many cases, the deformations determined by the certaingeometric feature of the products exceed material forming limit of the material. To this problem, thereis no related research at present. Reference to the method of adjusting the stamping direction, it is asimple and feasible method that changing the space position of products in the NC incrementalforming. This method not only can avoid fracture, but also can reduce the thinning rate of the parts ashigh as possible, and improve the performance of the products.In view of the above question, the main research contents are as follows:(1) Based on UG secondary development basis, it can create a simple module, read the vectors ofthe points from the part, and projection the vectors to the plane of XY,then analyze and calculate, andfinally get the best surface parts for laying off.(2) After determining the lofting surface, this paper puts forward a method of setting theaddendum and some key points in the NC incremental forming process.(3) A complex part will be produces by using the positive NC incremental forming process, toverify the correctness of the above theory.