基于工序加工能力的并行公差优化设计

提出一种基于工序加工能力的并行工序公差优化设计方法。在产品的初步结构设计阶段，通过相配零件的加工工艺规划把装配功能公差表示为零件的工序公差，建立以加权制造总成本最小为目标，以并行公差链、标准化的工序公差系数、机床最大经济极限公差为约束的非线性并行公差优化设计模型，求解该模型得到最佳的工序公差。最后给出了并行公差优化设计的一个工程实例，结果表明，所提的方法具有比传统串行等精度方法更合理、工序公差数值更大的优点。

Optimal Concurrent Tolerancing Based on Sequential Process Capabilities

A new method for optimal concurrent process tolerancing is proposed. In the stage of structure design for a product, the information related to the process planning is used. The functional tolerances of the assembly of a product are considered as process tolerances. A nonlinear optimal concurrent process tolerancing model has been established to minimize the total manufacturing cost with different weight factors of the operations for the product. The constraints include concurrent process tolerance chains, the standard coefficient of process tolerance, and the economical maximum tolerance of the machine tool. Optimal process tolerances can be obtained through the use of an appropriate optimization algorithm for the model. Finally, a practical example is introduced. By contrast, the conventional uniform-precision allocation method has also been applied. The comparison of final process tolerances obtained by the two different methods shows that the proposed approach has advantages over the conventional uniform-precision one in rationality and largeness of the assigned process tolerances.