Research On Machining Tool-path Interactive Modification And Optimization Of Sheet Metal Incremental Forming

Sheet metal incremental forming technology is a flexible manufacturing technology, it originates in the principle of layered manufacture in rapid prototyping technology. The characteristics of this process are: at first designing the three-dimensional numerical model of the part, and building the tool-path according to the model, finally using the tool-path to drive the incremental forming machine and process. The tool-path has huge impact to the incremental forming during the process, if the partial tool-path of difficult forming doesn't match the principle of the incremental forming, the defects, such as breaches, dents, and so on, will occur. Usually the modification of the partial tool-path is on the CAD software, by modifying the three-dimensional numerical model. This paper studies modifying the tool-path interactively, achieves fast-response in machining process of the sheet metal incremental forming.In order to decrease the breaches and tents occurred in machining process, a new method named machining tool-path interactive modification and optimization based on NURBS is provided in this paper. Based on the knowledge of NURBS, the paper studies the NURBS curves approximation algorithm to constrained discrete points, the modification of NURBS curves, the smoothness and fairness of NURBS curves, the approaching algorithm to NURBS curves with lines and arcs, the examination of NC path. According to the characteristic of NC Sheet Metal Incremental Forming technology, the suitable algorithm is chosed and the software mould is designed with Visual C++6.0.Based on the machining tool-path interactive modification and optimization, author improve on the traditional techniques of Sheet Metal Incremental Forming, carry out the method of non-anticipation machining tool-path, carry out the function of forming the specify layer, ameliorate the method of forming vertical wall parts, realize the interactive modification and optimization of breaches and tents. By abundant of experiments, author validates the superiority of the ameliorative techniques.