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

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