基于新一代产品的几何技术规范,分析了装配体的几何信息构成,给出了基于自由度分析的变动域建模原理和变动域-SDT(small displacement torsor)映射关系,采用齐次坐标变换描述了特征几何变动在装配体中的传播和累积,建立了包含零件公差信息和装配间隙信息的装配公差累积模型;构建了公差回路的矩阵表达式,用两个简单装配公差分析实例说明了零件可装配性条件及分析过程;最后以一个工程计算分析实例验证了方法的正确性。
Based on new generation GPS(geometrical product specification and verification), the compostion of geometrical information of assembly was analyzed. The modeling method based on DOF (degree of freedom) analysis and mapping relations between variation zone and SDT (small displacement torsor) were studied. The propagation and accumulation of characteristic geometrical deviation were described using HTM (homogeneous transformation matrix), and the assembly tolerance accumulation model including tolerance information of part and gap information of assembly was established. Then,matrix equation of tolerance loop was put forward. Two simple examples were used to explain the condition of part assembly feasibility and assembly tolerance analysis process. Lastly, an example of engineering analyzing and computing was presented.