A study on a method of dividing machine-parts into functional groups for technical illustrations

The authors previously presented a computer generation method of technical illustrations of a machine from its CAD model. However, parts of complicated structures in a machine are more comprehensible when they are expressed in the form of TIs which consist of several illustrations representing functional subgroups of a machine than in a picture containing the total massive structures. There arises a problem of how to divide a machine into functional parts. The authors attempt to provide an answer to it by means of processing a specific graph derived from a CAD model of a given machine. The authors propose a method based on a directed graph representing a few structural aspects of a machine. The graph represents two kinds of relations, namely inserting a part to another part and connecting parts by a gear, by directional arcs, and also the shapes of parts by distinguishably shaped nodes. The basic idea is to describe a kind of semantics by structural features of a machine in a symbolic way based on the above-mentioned mechanical relations and the shapes of parts reflecting functions of parts