机械零件切削成形的几何学理论和方法体系研究

Study on geometric theory and methods system of cutting forming for mechanical parts

随着社会经济的快速发展,表面采用复杂曲面的机械零件越来越多。传统的基于发生线概念的机械零件切削成形理论和方法体系已经不能满足机床运动分析、运动控制以及加工质量控制等的需要,有必要结合几何学方法建立新的机械零件切削成形理论和方法体系。首先,分析了传统的基于发生线概念的机械零件切削成形理论和方法体系,列举了传统理论和方法体系的不足,论述了传统方法体系不能全面、严谨和精确的阐释机械零件切削成形的本质。然后,提出了一种基于几何学和刀具分类的机械零件切削成形理论和方法体系,包括:(1)使用非旋转刀具,由切削刃曲线的运动扫描形成工件表面;(2)使用旋转刀具,工件表面为刀具曲面运动所形成曲面族的包络。新理论和方法体系能全面、严谨和精确地解释机械零件切削成形的几何学本质,满足应用越来越广泛的数控加工复杂曲面时刀具轨迹控制及工件表面求解的需要。最后,针对球头刀数控铣削曲面,应用共轭曲面原理给出了刀具轨迹和工件曲面的求解方法。

With the great development of social economy,more and more mechanical parts with complex surface are adopted.The traditional theory and methods system of cutting forming for mechanical parts based on concept of generating line can not satisfy the needs of machine tool motion analysis,motion control and processing quality control,so it is necessary to build a new theory and methods system of cutting forming for mechanical parts with geometric methods.Firstly,the traditional theory and methods system of surface cutting forming for mechanical parts based on concept of generating line is analyzed.The shortcomings of the traditional theory and methods system are discussed,and it has pointed out that the traditional theory and methods system can not fully and rigorously and illustrates and precisely the essence of surface cutting forming for mechanical parts.Then,a methods system of surface cutting forming for mechanical parts based on geometry and tool classification is proposed.The new methods system includes:(1)Using a non-rotating tool,the work-piece surface is formed by motion scanning of the cutting edge curve;(2)Using a rotating tool,the surface of the work-piece is the envelope of the surface family formed by the move-ment of the tool surface.The new theory and methods system can fully and rigorously and precisely illustrates the geometry essence of surface cutting forming for mechanical parts.The requirement of tool path control of NC cutting complex surface and solution of work-piece surface is met,it is applied more and more widely.Finally,for NC milling Surface,the solution method of tool path and work-piece surface is given spherical milling tool.