Study On The Key Technologies Of The High-performance Of CNC Machining For Complex Curves

With the rapid development of science and technology, the requiring of CNC machining technology of products with complex curves and curved surfaces in industry becomes higher and higher. In recent years, the critical techniques of machining complex curves and curved surfaces are high-speed, high-precision, stability in machining and fairness of tool-path. The design of tool-path in the processing of CNC machining directly affects the properties of products.Taking the research of tool-path interpolation for the complex curve with Gl continuity type as a starting point, the "frame interpolation" used in the existing three-axis CNC machining is provided, which is based on the principles of circular interpolation and linear interpolation.First, based on B-spline curve, the paper proposed a new interpolation method for tool-path, "frame interpolation". This new spline fitting method is easy to program and calculation. Taking the machining worktable rotate factors in the influence of the quality of products into account, this method provides a new Tool Path Generation Algorithm.Second, according to the principles of errors generated in processing, the "equal-chord recursive deviation fitting algorithm" is given, a method based on B-spline tool edge of step length. It can help the "frame interpolation" to achieve high-speed and simplicity in CNC machining.Then, the paper discussed the phenomenon of the NC machining tool wear and tool for transformation caused by the processing sites. By using the compensation principle of cutting tool, machining cutting error caused by "frame interpolation"can be effectively compensated.Finally, by analyzing a practical case using "frame interpolation" method,, the feasibility of high-precision in fitting data for machining complex curves and curved surfaces is verified. Compared with the other interpolation methods, the "frame interpolation" has superiority and practicability in several aspects such as fitting precision, computational efficiency, computational stability.