Study On Calculation Method Of Non-interference Cutter Pass For Complex Surfaces With NC Machining

With the development of aviation, automobile, shipbuilding and tool marking, more and more complex surfaces are used in these areas. Because the forming principle, precision assurance and machining for complex surface are difficult, CNC automatic programming system is adopted in CNC processing. In this thesis, through the research and exploration, we expand the scope of the tool path calculation of pre-processing technology in CNC system for complex surfaces, to consummate the processor of numeric control automatic programming for complex surfaces.Firstly, the general models are built for the workpieces and cutters in this thesis. For workpieces, the parameter equations and discrete data input are used. For parametric surfaces, we first make it discrete to reconstruct new surfaces with Ferguson bicubic surfaces and build uniform workpiece model. At the same time, the calculation method of boundary information matrix and the creation of the boundary condition are thoroughly studied. For cutters, we set up general cutter model with two conical surfaces and round surface by colligating geometrical characteristic of all kinds of milling cutter. At the same time, parametric equation of every surface and the law vector equation of the general cutter are given, the actual model of typical milling cutters are analyzed, and the interface of tool choice and friendly parameter input approach are provided. These lay foundation for the calculating software of non-interference cutter pass.In this thesis, the principle of minimal orientation-distance, optimizing method at five points and the tool interference checking algorithm based on genetic algorithms that is improved for some practical reasons are introduced. We have developed the module of generating cutter pass and interference checking through numeric control self-programming for complex surfaces.Finally, basing on the thought of software engineering, VB is used to programming and operational interface is generated, so the practical advanced processor of automatic programming system for complex surface is, and the manipulation simple and man-machine interactive interface is actualized. At the same time, the function and usage of the pre-processing of CAM system for complex surfaces are introduced briefly.