Enhanced definition and required examples of common datum imposed by ISO standard

2017 International Conference on Material Engineering and Advanced Manufacturing Technology

Yan, Yiqing^1 ; Bohn, Martin^1

Tolerancing and Dimensioning Body-in-White, Mercedes-Benz Cars, Daimler AG, Sindelfingen, Germany^1

关键词: Common datum;    Geometrical product specification;    New approaches;    Orientation constraint;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/282/1/012016/pdf
DOI  :  10.1088/1757-899X/282/1/012016

来源: IOP

【 摘 要 】

According to the ISO Geometrical Product Specifications (GPS), the establishment and definition of common datum for geometrical components are not fully defined. There are two main limitations of this standard. Firstly: the explications of ISO examples of common datums are not matched with their corresponding definitions, and secondly: a full definition of common datum is missing. This paper suggests a new approach for an enhanced definition and concrete examples of common datum and proposes a holistic methodology for establishment of common datum for each geometrical component. This research is based on the analysis of physical behaviour of geometrical components, orientation constraints and invariance classes of datums. This approach fills the definition gaps of common datum based on ISO GPS, thereby eliminating those deficits. As a result, an improved methodology for a fully functional defined definition of common datum was formulated.