Unified reference system for geometric characteristics dimensional elements of details. Part II. Geometric characteristics of cylindrical elements of parts

Abstract

The unified reference system for the geometric characteristics of the part is the Cartesian rectangular coordinate system, which is materialized by sets of design datums that limit the part to six degrees of freedom: three linear and three angular. ISO standards for geometric tolerances do not use coordinate systems. In this context, research in the field of increasing the accuracy of parts by introducing linear and angular coordinates of part elements is relevant. The paper presents the second part of the article Unified Reference System for Geometric Characteristics of Dimensional Elements of Parts, which focuses on the geometric characteristics of cylindrical elements of parts. It is shown that the datums of cylindrical elements are the axes of cylinders of maximum material capable of restricting four, two and one degrees of freedom for the part depending on the functional purpose of the element. The accuracy of coordinating dimensions should be specified by symmetrical tolerances for linear and angular coordinates of elements.

Keywords

• geometric characteristics
• cylindrical elements of parts
• workpiece coordinate systems
• design bases
• actuating elements
• informativeness of elements
• linear and angular coordinates