汽车车身部件由薄板冲压件经过层级焊接装配而成，其板材具有较大柔性.在外部载荷作用下产生的变形将直接影响装配偏差的传递与累积，并最终影响装配精度和使用功能.针对车窗升降不平顺问题，考虑外界载荷对车门内板变形及装配偏差的影响，建立包含内板变形的车窗升降三维装配公差分析模型，揭示密封阻力、车门内板变形和刚度对车身部件装配性能的影响.以公差收严的收益比为评价因素，实现了考虑车门内板柔性变形的车窗升降系统公差优化设计.结果表明：在导轨-托架匹配面的面轮廓度收严到0.5mm、玻璃-托架安装孔位置度收严到0.9mm的情况下，车门模型的装配公差符合设定目标，满足升降平顺性要求.
The automobile body is made of sheet metal stamping parts which are welded and assembled hierarchically. The sheet metal of the automobile body has a great flexibility. The deformation caused by external load will directly affect the transmission and accumulation of assembly deviation and finally affect the assembly accuracy and function. This paper focuses on the problem of inconsistency in the window lifting process, and a 3D assembly tolerance analysis model including finite element deformation is established to reveal the influence of sealing resistance and the rigidity of the inner panel of the door on the assembly state of the lifter. Based on the benefit ratio of tolerance optimization as the evaluation indicator to determine the optimization plan, an optimized tolerance design and an improved lifting consistency are realized. The results show that when the surface profile of the matching surface of guide rail and bracket is tightened to 0.5mm and the position of the mounting hole of glass and bracket is tightened to 0.9mm, the assembly tolerance of the door model conforms to the set goal and meets the requirements of lifting smoothness.
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