关键词: 基准参考框架, 构造元素, 基准要素, 通用化

Abstract: To general and automatic establish Datum Reference Frame (DRF) in tolerance analysis and geometric features measurement,an automatic and general construction method of DRF was proposed.DRF was regarded as the composition of three constructing elements with specific positional relations: the origin,an axis and a coordinate plane.The geometric forms of both DRF and datum features were unified by utilizing this classification,which was convenient for establishing DRF.By researching the formation of point,line and plane,the corresponding relationship between DRF and datum features was built,and the combination of datum features in the datum system of geometric tolerance was mastered.The computation rules of datum feature simulator were given according to the datum order and datum embodiment principle.According to the geometric characteristic of the constructing elements and the datum precedence and datum geometry,the construction methods of the constructing element of DRF were established.The proposed method was applied in assembly tolerance analysis software prototype system,and the result showed that this method was consistent with the tolerancing standard,and had stronger operability than other existing methods.

Key words: datum reference frame, constructing elements, datum features, generalization