Development Of Three Axis Numerical Control Program Software For Compound Surface

Compound surface parts have been widely used in aircraft,automobile,ship and mold manufacturing industries.How to generate continuous tool-path planning on a compound surface without topological relationship is the key to the production of enterprises.According to the actual needs of enterprises,this paper studies on tool path planning for shoe last compound surface and the method of calculating cross-border tool path.Finally,tool-path planning method and cross-border algorithm are embedded in NC programming software.Then the experiment is carried out with tool path,the test and analysis of the research results are completed.Firstly,this paper uses IGES compound surface data of shoe last.The surface and clipping information are extracted.The B-spline surface is constructed by the algorithms of interpolation.After setting guide points from the helix and using iteration algorithm,Helix projection method is used to calculate the projection points of the guide points on the surface along the helix radius direction.The problem of different normal vector directions is solved by the angle restriction algorithm.According to the principle of projection method,a projection point encryption algorithm is developed to solve the problem of sparse projection points in some parts.Secondly,surface boundary conditions are classified.Different methods and cross-boundary algorithms are proposed for different conditions.A point selection algorithm is proposed for trimmed surfaces.This algorithm uses ray method to screen projection points in parameter domain.After the final projection points calculated,the tool path is generated according to the machining tool and normal vector.Thirdly,the NC programming function of composite surfaces is embedded in the MFC application program of VC platform developed by C++ programming language.In the software,IGES file reading,displaying and NC programming are completed.According to the needs of enterprises,the human-computer interaction function is developed,and the realization algorithm of each function is given.Finally,the post-processing algorithm of NC program is given according to processing mode.The numerical control program is simulated by VERICUT.After verification,the experiment is completed by using laboratory machine tools,which verifies the correctness of the research content in this paper.