Virtual Machining of High Speed Mechining and Its Application to Machining System

高速切削是一种具有高经济性和高质量的加工技术。此外，它还有望成为一种无需研磨或抛光就能完成产品的技术。然而，高速加工可能仅在某些特定的加工领域有效。高速切削加工的性能评价需要借助计算机仿真技术进行有效的虚拟加工，这对优化加工工艺具有潜在的意义。本文研究了不同刀具和切屑形态下，由于工件材料和切削条件的不同组合而引起的各种切削变形，首先发展了澄清加工现象，使用不同的形式和有限差分法的有限元方法。所考虑的切屑形成是连续的、不连续的和锯齿状的。在二维加工中，刀具类型为平面刀具和槽形刀具，在三维加工中，刀具类型为单刃刀具和立铣刀。在此应用中，刀具几何形状对刀具磨损、刀具破损和切屑控制的影响通过使用切削温度、刀具面上的应力、刀具变形和切屑变形和破损来阐明。确定了给定切削条件下的最优刀具几何形状和给定刀具几何形状下的最优切削条件。研究了通过虚拟加工方法实现切削状态监测与切削操作规划的集成。

High speed machining is one of promising technologies that will yield high economical production and high quality of the machined elements. Moreover, it is expected as a technology which can finish the product without the processes of grinding or polishing. However, high speed machining may be effective only in some particular areas of machining. No strategy for exploring such areas has been proposed and found. Thus the performances of high speed machining should be effectively evaluated by the virtual machining with the aid of computer simulation, which has a potential for optimizing machining operations.In this research the various types of modiling of machining with different tools and chip formations, which caused by different combinations of work materials and cutting conditions, were first developed for clarifying the machining phenomena using finite element methods with different formations and finite difference method. The chip formations considered are continuous, discontinuous and serrated. The types of tools are flat and grooved in two dimensional machining, while a single point tool and an endmill are considered in three dimensional cutting.Next the virtual machining methods are applied to the optimization of tool geometry. In this application the influences of tool geometry on tool wear, tool breakage and chip control were clarified by using cutting temperature, stresses on the tool face, tool deformation, and chip deformation and breakage. Then the optimized tool geometry for given cutting conditions and the optimized cutting conditions for given tool geometry were determined. The integration of cutting condition monitoring and cutting operation planning through the virtual machining method was investigated.