GB/T1182和ISO1101形位公差标准的两个主要特征之一是采用几何区域即所谓公差带来限制几何要素的形状、方向、位置误差.本文将阐述这两个标准中有关几何公差带的若干问题.
一、公差带形状的决定要素
ISO 1101:2000 第4.4条称"Accor...GB/T1182和ISO1101形位公差标准的两个主要特征之一是采用几何区域即所谓公差带来限制几何要素的形状、方向、位置误差.本文将阐述这两个标准中有关几何公差带的若干问题.
一、公差带形状的决定要素
ISO 1101:2000 第4.4条称"According to the characteristic which shall be tolerated and the manner in which it is dimensioned, the tolerance zone is one of the following",即"由公差所控制(几何)特征和相应的误差测量方法所决定的公差带形状将如下列之一".示意公差带形状将取决于形位公差代号框格里的几何特征符号和相应形位误差测量方法.其实不然--形位公差带的形状只取决于被测要素的几何性质和公差代号框格里的公差带形状符号(见表1)有关,而与几何特征符号、形位误差测量方法无关.展开更多
Recent development in computer-based manufacturing and inspection has necessitated extended knowledge and usage of geometric tolerances as carriers of design intent. The aim of applying geometrical tolerances in desig...Recent development in computer-based manufacturing and inspection has necessitated extended knowledge and usage of geometric tolerances as carriers of design intent. The aim of applying geometrical tolerances in design is to provide function-oriented precise description of part geometry where the conventional size tolerance system fails to address. In view of the current development of computer-aided systems, applying geometric tolerances opens a new research front. This article examines the challenges in applying geometric tolerance information to carry the design intent to other downstream manufacturing processes and intelligently integrate the whole system. Based on the observed practical capabilities and literature studies, it is concluded that the current computer-aided design （CAD） systems cannot effectively provide the appropriate use of geometric tolerances. This article highlights the existing challenges and proposes a scheme of algorithm development for appropriate use of tolerance symbols and conditions at the design specification stage. This, in the long run, enables the CAD model to carry the design intent and opens a window of opportunity for intelligently integrating manufacturing systems.展开更多
文摘GB/T1182和ISO1101形位公差标准的两个主要特征之一是采用几何区域即所谓公差带来限制几何要素的形状、方向、位置误差.本文将阐述这两个标准中有关几何公差带的若干问题.
一、公差带形状的决定要素
ISO 1101:2000 第4.4条称"According to the characteristic which shall be tolerated and the manner in which it is dimensioned, the tolerance zone is one of the following",即"由公差所控制(几何)特征和相应的误差测量方法所决定的公差带形状将如下列之一".示意公差带形状将取决于形位公差代号框格里的几何特征符号和相应形位误差测量方法.其实不然--形位公差带的形状只取决于被测要素的几何性质和公差代号框格里的公差带形状符号(见表1)有关,而与几何特征符号、形位误差测量方法无关.
文摘Recent development in computer-based manufacturing and inspection has necessitated extended knowledge and usage of geometric tolerances as carriers of design intent. The aim of applying geometrical tolerances in design is to provide function-oriented precise description of part geometry where the conventional size tolerance system fails to address. In view of the current development of computer-aided systems, applying geometric tolerances opens a new research front. This article examines the challenges in applying geometric tolerance information to carry the design intent to other downstream manufacturing processes and intelligently integrate the whole system. Based on the observed practical capabilities and literature studies, it is concluded that the current computer-aided design （CAD） systems cannot effectively provide the appropriate use of geometric tolerances. This article highlights the existing challenges and proposes a scheme of algorithm development for appropriate use of tolerance symbols and conditions at the design specification stage. This, in the long run, enables the CAD model to carry the design intent and opens a window of opportunity for intelligently integrating manufacturing systems.
