尺寸链换算引起的超差分析

Dimension Chain Conversion Caused by Error Analysis

缸盖机加工工艺中,零件多数采用一面两销进行定位加工,不同工位加工出现的多次定位需要考虑尺寸链换算,尺寸链是否闭环影响特征精度,从而影响零件装配、发动机燃油经济性以及耐久性和排放。通过尺寸链环关系分析,收严上工序公差或放宽下工序公差,达到尺寸链闭环,从而避免特征超差风险。

In the machining process of cylinder head machine,most parts are positioned and processed with one side two pins. The multiple positioning of different position processing needs to consider the conversion of dimension chain,the close loop of the dimension chain affects the feature precision,which affects the assembly of the parts,the fuel economy of the engine,and the durability and discharge. To analyze and strictly accept the tolerance of the upper process or to relax the tolerance of the next process so as to achieve the closed loop of dimension chain,so as to avoid the risk of characteristic overshoot.