关键词: 公差分配, 尺寸公差, 形位公差, 成本—公差函数

Abstract: To solve assembly optimal-tolerance allocation for composite dimensional and geometric tolerances, a tolerance optimal allocation method was presented. Based on the cost-tolerance function and the relationships between dimensional and geometric tolerances, a nonlinear optimal tolerance allocation model was established aiming to minimize the total manufacturing cost. Constraints included functional requirement of assembly dimension chain and the machining capability. Optimal dimensional and geometric tolerances could be obtained by an appropriate optimization algorithm for the model. Finally, the tolerance optimal allocation method for composite dimensional and geometric tolerances and the conventional method were applied to allocate tolerances for an example. Results indicated that the proposed approach was better than the conventional method.

Key words: tolerance allocation, dimensional tolerance, geometric tolerance, cost-tolerance function