Abstract: This paper takes the rear end quality as the research object, in order to solve the gap and transition issues in the trunk lid assembly, taillight assembly and rear bumper assembly, so that the one-time delivery pass rate in assembly shop can be increased. To solve the rear end quality issues in assembly shop systematically, counter measures like optimizing the dimension of the body-in-white, controlling the dimension of the incoming parts and adjusting the assembly process. Propose the concept of "manufacturing tolerance" for assembly and welding, and develop more than 30 dimensional control tolerances suitable for the final assembly requirements of the body-in-white. A standard gun change process has been formulated, in order to minimize the dimension fluctuation of the rear bumper bracket-welding nail caused by the gun change, and control the fluctuation from issue source. A closed-loop control of dimension fluctuation is formed, including issue detection, dimensional optimization and verification of final assembly status. Through all these measures, the final rework time can be reduced by 2 000 h per year, and the one-time delivery pass rate of final can be increased by 15.4% in assembly-shop.

Key words: Trunk lid assembly; Tail lamp assembly; Rear bumper assembly; Gap and transition; Body rear end; Composite quality issue

摘要： 文章以某车后部装配质量为研究对象，旨在解决后备箱装配、尾灯装配以及后杠装配 存在的间隙、平顺度复合问题，提升总装一次交验合格率；通过对白车身尺寸进行调整，对 来件尺寸进行控制以及对装配工艺进行调整等措施，系统解决后部装配质量问题。提出装焊 “制造公差”概念，制定了适合总装装配需求的白车身尺寸控制公差 30 余项；制定了标准换 枪流程，将换枪后造成的后保险杠支架焊钉的尺寸波动，从尺寸波动的源头激发问题，检测、 调整、验证到最终总装反馈，形成尺寸波动闭环控制；每年可降低总装返修工时 2 000 h，总 装一次交验合格率提升 15.4%。

关键词: 背箱装配；尾灯装配；后杠装配；间隙平顺度；车身后端；复合质量问题