Abstract : This paper introduces the method of arc polygonization in the die CAD system, and processes the non-circular punch and die shape. A method for automatically generating the main view based on the top view is proposed. I. Introduction When designing a stamping die, if the shape of the punch and die of the die is a simple shape such as a circle or a rectangle, the punch and the die are relatively easy to design, and the calculation of the edge size is also very simple. However, not all stamping die and die edge shapes are regular, and many stamping die punches and die have irregular edge shapes. They are composed of multiple segments or multiple segments. It consists of multiple arcs or is composed entirely of multiple arcs. The calculation and design of the edges of these punches and dies are troublesome. Due to the complicated shape of the non-circular punch and the non-circular die, in order to facilitate the processing, the inner cavity of the non-circular punch and the non-circular die are designed into a straight column at the time of design, which is convenient for automatic design using a computer. If a computer is used to realize the automatic generation of such punches and dies, and combined with CAM, not only can the designer's labor intensity be reduced, but also the design and processing efficiency and quality of the mold can be greatly improved. Second, the automatic generation of non-circular punches Various non-circular punches can be divided into two cases: the first type, the top view of the non-circular punch is completely composed of line segments; the second type, the top view of the non-circular punch is composed of line segments and arcs or completely by arc composition. For the second case, before the main view of the punch is generated, the arc in the top view must be properly processed, that is, according to the case of the arc, the projection effect of the arc in the main view is considered, and one or several segments are used. Instead of the arc in the top view, this method is called "arc polygonization." 1. Polygonization of an arc Analysis of various types of arcs, according to the projection principle, the replacement of arcs can be divided into three cases: (1) If there is a circular arc segment AB, as long as there is no intersection between the circular arc and the horizontal diameter of the circle, the arc segment AB can be replaced by the linear segment AB, as shown in Fig. 1a. (2) If there is a circular arc segment AB, as long as there are two intersection points C and D in the horizontal diameter of the circular arc and the circle, the arc segment AB can be replaced by three line segments AC, CD, DB, as shown in Fig. 1b. (3) If there is a circular arc segment AB, as long as there is an intersection point C between the circular arc and the horizontal diameter of the circle, the two arc segments AC and CB can be used instead of the arc AB, as shown in Fig. 1c. Figure 1 Arc Multilateralization Next page