Analyse offener und geschlossener Toleranzketten im parametrischen 3DCAD-System

DFX 2014: Proceedings of the 24th Symposium Design for X: Bamburg, Germany 1-2 Oktober 2014

Year: 2014
Editor: Dieter Krause, Kristin Paetzold, Sandro Wartzack
Author: Husung, Stephan; Weber, Christian; Geis, Annika; Oberänder, Axel
Series: DfX
Institution: Technische Universität Ilmenau
Section: Toleranzen und Robust Design
Page(s): 157-168
ISBN: 978-3-941492-79-0

Abstract

The paper deals with the representation of vectorial tolerances in the parametric CAD-model using surface-type specific attribute containers, which are attached to the desired nominal surfaces. A major motivation for their integration into the CAD-model is the similarity of the vectorial tolerance representation to the Boundary representation description in current CAD-systems.
A main focus of the paper is the handling of partially closed tolerance loops. Most of the CAT-systems only handle open tolerance chains. In contrast, a real system, even if the overall tolerance chain can be considered as an open chain, consists of partially closed tolerance loops just in the joints or base frames. The developed approach is based on the statically determined placement of a rigid body on three points, where the resulting line of action of the force - even for several parts - goes through the support triangle.

Keywords: vectorial tolerances; CAD; closed loops; boundary representation