Geometric relationships between toleranced features

摘要

The design for a mechanical part often includes tolerance information. Tolerances can be defined with tolerance zones and datums. A tolerance zone is a region of space in which a portion of the surface of a real part must lie. A datum is a point, an infinite line or an infinite plane. This paper shows how a toleranced part can be represented as a network of tolerance zones and datums connected by arcs to which inequality constraints are attached. The network can be extended to deal with assemblies of parts. The work can be applied in computer-aided design where a tolerance specification needs to be checked.