基于特征的公差表示方法与实现

Feature-based tolerance representation and its implementation

公差的存储表示是公差分析和公差综合的基础 ,提出一种几何公差的计算机辅助表示方法。利用特征的几何公差结构块 ,建立各种公差带的空间表示函数 ,并计算其三维空间中相应自由度的允许变动量。通过图论方法给出公差图的形式化定义 ,设计公差图的数据结构 ,可实现零件公差的计算机存储表示。最后给出零件实例来验证所提出的方法。

Representation of tolerances is a basis for tolerance analysis and synthesis.Proposes a computer-aided representation method to represent geometric tolerances.Through utilizing the geometric tolerance structure blocks(GTSB),the functions of specific zones of geometric tolerance are established and their allowable variations of degree of freedom in the corresponding directions in three-dimensional space are computed.Representation of geometric tolerance information is implemented by giving the formal definition of all sorts of geometric tolerances through using of graphic theory and by designing the data structure of geometric tolerances.Finally,a case study is given to validate the proposed method.