The Geometric Description and Data Structure for Bent Parts in a CAD/CAM System of Dies

In the CAD/CAM system of dies, it is very important to describe the geometric shape of parts. It is the basis of block development, process planning design, die parameter computation, die structure design and die draft output. In this paper, the geometric shape of the typical bent parts are emphatically discussed. Their structure is represented by "bending trees", and geometric and topologic information are described by surface model.