Advanced Iterative Approach To Locating Point Layout For Computer Aided Fixture Design

摘要

In the machining process, the parts dimension, geometric shape and the formation of the relative position between the surfaces, depended on the position of the workpiece related to the cutting tool in cutting motion process, while the realization of this mutual position relationship is through locating points layout restricts parts DOFs. For this reason, this paper presents the conceptions of theoretical constrained DOFs and Practical constrained DOFs, at the same time the paper innovatively presents locating points layout determination algorithm for complex parts. Firstly, established the DOFs limit model according to the condition that parts of absolute velocity is zero in the machining precision requirements, theoretical constrained DOFs is expressed as the function relation of machining precision requirements. Secondly, establishing the model of locating points layout according to the constraint condition that parts of normal absolute velocity is zero in the position of locating points, and describing Prctical constrained DOFs as the function relation between the position of locating points and normal vector. Then, according to the relationships between theoretical constrained DOFs and solves the model of locating points layout, constructed the automatic design algorithm of locating points layout. Finally, according to the proposed design algorithm, developed design and analysis modules of locating points layout by VC6.0 in the UG environment.