关键词: 产品几何技术规范, 拟合配合表面, 工作载荷, 修正矩阵, 公差模型

Abstract: On the premise of the rigid body hypothesis,the traditional tolerance model could not consider mechanical system's deformation under working load.Actually the performance of mechanical system had close relationship with parts'deformation under working load.Based on the idea of certificated surface model of Geometrical Product Specification (GPS),a modified tolerance model was proposed,which could consider the influence of complex deformation on tolerance analysis and forecast the end space of system function accurately.A traditional tolerance model was built using Small Displacement Torsor (SDT) and Homogeneous Transformation Matrix (HTM).The concept of fitted matting surface was proposed to consider the part deformation under working condition.According to the space relationship of actual deformed surface,fitted matting surface and ideal design surface,the modified method for traditional tolerance model was proposed.The procedure to obtain the modified matrix was discussed,and the modified model was built.Under the tolerance analysis of working load,the distribution of closed loop dimension was obtained.A tailstock was taken as an example to verify the feasibility of proposed method.

Key words: geometrical product specification, fitted matting surface, working load, modified matrix, tolerance model