考虑形位公差的二维装配公差分析

2-D Tolerance Analysis of Mechanical Assemblies Including Geometric Tolerances

形位公差是零件形状、位置特征变动的结果。虽然形位特征变动也可对装配的性能产生很大的影响,但是目前装配公差分析的研究主要集中于尺寸公差而很少考虑形位特征变动,迄今为止尚无一种较完善的包括尺寸公差和形位公差的分析方法。本文提出了一种新的基于矢量环装配模型的包括几乎所有形位特征变动的二维装配公差分析的方法。研究的重点是如何在矢量环装配公差分析模型中实现形位特征变动的描述,这种描述有助于考虑所有变动对于装配的影响从而实现包含形位公差在内的二维装配公差分析。最后给出一个工程应用实例,说明所提出的方法的有效性。

Geometric tolerances are the result of variations in the shape,orientation or location of part features.Although geometric feature variations can also contribute significantly to the performance of an assembly and should be considered in any comprehensive analysis,most researches on assembly tolerance analysis have focused on dimensional tolerances without accounting for geometric variations in the assembly.So far,no complete tolerance analysis approach has been developed to include both dimensional and geometric tolerances.A new,generalized approach for including all the geometric feature variations in the tolerance analysis using a vector-loop-based assembly tolerance model is presented.It focuses on how to characterize geometric feature variations in the vector-loop-based assembly tolerance model.The characterization will be used to help combine the effects of all variations within an assembly in order to realize tolerance analysis of mechanical assemblies including geometric tolerances.A practical example is presented to demonstrate the effectiveness of the proposed method.