零件表面上,由平面与立体相交得到的表面交线称截交线,也可以设想为平面截切立体产生的交线,这个平面称为截平面(图1)。一、圆柱、圆锥、圆球的截交线掌握平面与基本立体截交线的各种情况,是了解零件截交线的基础,这对提高识图和画图能力都是必要的。1.平面与圆柱面相交,截交线有三种情况(表1)。 Parts of the surface, the intersection of the plane and the surface of the intersection of the intersection of the surface intersection line, also can be imagined as the intersection of plane cut truncated lines, this plane is called the cutting plane (Figure 1). First, the cylindrical, conical, spherical cross-sectional line to grasp the plane and the basic three-dimensional cross-sectional line of the situation, is to understand the basis of the cut-off line parts, which enhance the knowledge and drawing capabilities are necessary. 1. Plane and cylindrical intersection, cut line there are three cases (Table 1).