关键词: 多色集合, 进给系统, 公差信息, 表示模型, 装配公差, 小位移旋量理论

Abstract: To compensate for the shortage of precision in the mechanical assembly process,a product assembly precision modeling based on polychromatic sets theory was proposed,which provided an efficient assembly precision intelligent calculation methods for designers in the initial design stage of product.A set of computer-aided automatic generation process of assembly precision was provided by this model,the assembly constraint matrix,assembly surface features constraint contour relation matrix,assembly tolerances type contour boolean matrix and assembly spatial relationships contour boolean matrix were constructed.The adjacency matrix was used to storage the information in computer.Thus the whole process mapping from part assembly surface feature extraction and feature constraints to assembly whole precision was realized.The model contained the extrinsic constraint conditions of product functional requirements,geometry features,tolerance criteria and tolerance allocation rule,which could illustrate the accuracy and practicality of the model.The effectiveness of model was proved by CNC machine tool feed system application.

Key words: polychromatic sets theory, feed system, tolerance information, representation model, assembly tolerances, small displacement torsor