基于构造元素的基准参考框架通用建立方法

General approach to establish datum reference frame based on constructing elements

为了在公差分析方法和几何要素检测过程中通用和自动建立基准参考框架,提出一个建立基准参考框架的通用化和自动化方法,将基准参考框架分解为点、过点的直线、过直线的平面三个构造元素,使得基准参考框架与基准要素的几何组成相同,从而便于基准参考框架的建立。通过研究点、线、面的形成规律,建立了基准参考框架和基准要素的对应关系,并掌握了几何公差基准体系中基准要素的全部组合情况。根据基准次序和基准体现原则建立了模拟基准要素的确定规则,根据构造元素的性质和基准次序与基准几何,建立了构造元素的确定方法。最后,将所提方法应用在装配公差自动分析软件原型系统中,结果表明,该方法完全符合公差标准规定,且比现有方法具有更强的可操作性。

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.