Research On The Method And System Of Single Point Incremental Forming Of Sheet Metal

Single point incremental forming(SPIF)is a sheet metal plastic forming technology based on the idea of "layered manufacturing",it is suitable for the production demand of single piece of small batch,diversified and complex shape products,In the process of sheet metal forming without special fixture,with high flexibility,forming a small,short product design cycle advantages,and can effectively make up for the traditional stamping products,high cost of development,poor flexibility and other issues.In the process of single point incremental forming,the forming trajectory has a great influence on the quality and forming time of the forming part.With the development of the single point incremental forming technology,the forming trajectory conforming to the incremental forming characteristic is obtained to improve the quality and efficiency of the forming part has important significance.Based on the analysis of the relationship between the residual peak height of the adjacent tool and the surface roughness of the forming element,an adaptive layered trajectory generation algorithm combining the residual crest height with the normal vector of the STL triangular facets is proposed.In order to improve the reliability and hierarchical efficiency of the algorithm,the topological relations between the triangular patches of STL model are analyzed according to the topology theory.The method of recursive stratification is used to realize the rapid stratification of the STL model,and the running speed of the trajectory generation algorithm is improved.A method is proposed to determine the cross-sectional profile of each layer according to a cross-sectional cut’s first triangular facets intersection,to ensure the consistency of all the layered cross-sectional contour.In the stage of using the layered contour to generate the machining trajectory,the problem of the geometrical distortion caused by the local depression,the rupture and the forming direction of the part is analyzed.A new type of mixed layer feed trajectory is developed,and a method for generating helix trajectories is described for forming parts with circular features.In the Qt Creator development platform using C++programming language,prepared a single point incremental tooling trajectory generation system,and an example is used to verify the reliability of the system.In order to make the newly developed forming trajectory suitable for different types of numerical control system,G code program generation module is designed according to the characteristics of single point incremental forming and numerical control system.Using the combination of simulation and experiment,For the single point of incremental molding commonly used in the typical parts,that is,with rectangular features of the square cone and circular features of the cone.The influence of the newly developed forming trajectory on the quality of the forming part,the forming time and the forming force on the axial force of the forming part are verified by using the newly developed forming trajectory and the traditional leveling trajectory.