数控车床经常用于加工一些轮廓比较复杂的工件。一些工件中常见的结构是，其轮廓是由许多线段和圆弧光滑连接起来的。归纳起来，大致分为三类：第一类为直线与直线，直线与圆弧，圆弧与圆弧间用半径已知的圆弧光滑连接（简称修圆）；第二类为圆弧与圆弧间用一公共切线光滑... CNC lathes are often used to machine some of the more complex parts. The common structure in some workpieces is that the outline is smoothly connected by many segments and arcs. To sum up, roughly divided into three categories: the first category is straight and straight lines, straight lines and arcs, circular arcs and arcs with a radius between the known arc smooth connection (referred to as rounding); the second category arc Between the arc with a common tangent smooth ...