尺寸链法解算零件定位误差研究

Research on the positioning error of parts by dimension chain

为了能够在机床夹具设计时快速得到定位零件的定位误差值,给夹具的改进、设计提供参数参考依据,针对传统零件定位误差算法的不足,提出一种尺寸链公差法计算零件定位误差。从零件定位误差尺寸链模型的建立、尺寸链中组成环的查找、封闭环的计算入手,通过零件定位误差的尺寸链算法分别对零件外圆、内孔、平面三种定位情况的求解展开论述,并通过传统零件定位误差解算方法进行结果验证。结果表明:零件定位误差的尺寸链公差算法不仅不需要单独分析计算零件的基准不重合误差和基准位移误差,更不需要判明误差的变动方向,使计算变得简捷、明快。

In order to quickly get the positioning error value of the positioning parts in the machine tool fixture design,and provide the parameter reference for the improvement and design of the fixture,in view of the shortcomings of traditional positioning error algorithm,a dimension chain tolerance method was proposed to calculate the positioning error of the parts.Beginning from the establishment of the dimension chain model of the positioning error of the parts,the search of the composition rings in the dimension chain and the calculation of the closed rings,the solution of three kinds of positioning,including the outer circle,the inner hole and the plane of the parts was discussed by using the dimension chain algorithm of part positioning error,and the result was verified by using traditional method of part positioning error.The result shows that the dimension chain tolerance algorithm of part positioning error does not need to analyze and calculate the benchmark misalignment error and datum displacement error separately,and it is not necessary to determine the direction of error change,so that the calculation becomes simple and quick.