計算機輔助幾何公差表示法之發展

Abstract

Tolerance analysis is one of the bottlenecks in the accuracy evaluation of precision machinery. To perform the analysis, it is necessary to develop a systematical tolerance representation scheme and to computerize it as a tool for computer-aided tolerance design. This paper is focused on the development of a systematical tolerance representation scheme, including the construction of the representation architecture; the classification of geometric elements: geometric features, constraints, and tolerances, as well as the representation of dimensions, tolerances, and mating conditions. The developed scheme is implemented as a graph, called the Tolerance Network, in a computer-aided tolerance design system. The network is established using object-oriented design methodology to construct the data structure, objects and its associated properties and methods. The developed scheme is capable to support tolerance analysis and synthesis by reasoning about the network.

公差分析是精密機械精度分析的瓶頸之一，然而欲進行此分析，首先須要建立一套系統化的表示法架構，進而使之計算機化，以作為公差設計的基礎。本文描述所發展之一套系統化的公差表示法理論，並將之計算機化，該理論是以圖象表示法為基礎，其主要成果在於建立產品架構與公差網路理論，並以公差網路來表示產品零件之間公差配合的關係以及零件特徵之間幾何拘束與幾何公差的關係。上述理論同時以物件導向設計方法建構其資料結構、物件之型態、特性與方法、以及物件之連結方法，發展成一套計算機輔助公差設計系統之表示法模組。