关键词: CAD，特征造型，特征，参考线

Abstract: Feature modeling is the key technique in CAl)system, and topological entity naming is one of the essential issues of feature modeling. A feature-based method was proposed to name the surfaces of feature entities, then name edges and vertices of feature entities. Because of invariance of feature name in process of modeling, topological entities can be correctly recorded and maintained in model editing. The conception of reference line and its definition principle were proposed to solve topological edge splitting and multiple intersecting curves generated by two surfaces, which can identify and refer the splitting edges and multi-intersections efficiently.

Key words: CAD, Feature modeling, Feature, Reference line