基于工序切削体的三维公差模型"

3-D Tolerance Model Based on Operation Removal Model

在工序特征识别的基础上,提出了一种基于工序切削体的三维公差建模方法。该方法视毛坯模型为零件模型和工序切削体集合的装配体,利用小位移旋量描述零件和工序切削体的公差旋量,计算各旋量的变动约束;构建工序切削体集合的公差网络图,探讨设计公差在工序公差网络中的传播机制,建立工序公差累积模型,为工序公差设计提供基础。最后,通过实例验证该方法的有效性,并说明基于该建模理论的工序公差分配方法。

A method of 3-D tolerance modeling and analysis for operation removal model was proposed based on operation feature recognition. The roughcast was considered as the assembly of part model and operation removal models. Small displacement torsor （SDT） theory was used to describe design and process tolerances while the changeable constrains of tolerance torsors were calculated. The tolerance network graph of the operation removal models was constructed and the tolerance propagation mechanism in the tolerance network was discussed. Then the process tolerance stack-up models were achieved, which was the basis of process tolerance allocation. Finally, a case was analyzed to verify the validity of the proposed theory. The process tolerance allocating method based on the proposed theory was mentioned briefly.