基于统计公差的尺寸链与力耦合分析方法的研究

Analysis Method of Dimensional Chain and Force Coupling Based on Statistical Tolerance for Circuit Breaker

功能设计法是一种针对客户需求,定义功能条件并分析功能条件的方法。该方法在设计中,采用统计学的分布理论,在保证功能需求的前提下,找出关键因子。机构设计中,除了尺寸外,力也是关键因子。机构设计中尺寸及力都存在公差,而且它们的影响往往耦合在一起。笔者从功能设计方法入手,定义了断路器的关键功能条件,构建其力与尺寸耦合的新的公差链模型。定量分析了力及尺寸耦合的公差对机构性能的影响。统计结果显示,该方法与实际情况吻合。这种方法明显提高了机构设计效率,提高了产品质量稳定性,在考虑加工能力前提下,将严酷的公差带进行合理分配,从而也降低了生产成本。

In the function design method, both dimension and force are the key parameters. Tolerances exist in thetwo parameters in mechanism design. In this paper, the function design method is adopted to define the keyfunction conditions of a circuit breaker, and a new tolerance chain model of dimension and force coupling isestablished. Then the tolerance impact of the dimension and force coupling chain on the circuit breaker mechanismis analyzed quantitatively. Test result shows the analysis is consistent with the actual situation. The proposedmethod can increase design efficiency and quality stability of the mechanism, reasonably distribute strict toleranceband, and reduce production cost.