关键词: 白车身；螺柱焊接；螺栓脱落；扭矩检测；内饰件

Abstract: In view of the frequent falling off of a M5 steel stud on the body in assembly shop, this paper analyzes the fracture phenomenon of the body and the falling off stud. Also the welding process and assembly process of the M5 stud near the issue stud and the shape of the assembly hole of the interior trim are compared. And carries out a large number of tests with different tightening torques and different tightening methods in body shop. The result analysis shows that the root cause of frequent falling off of M5 welding stud is that the selection of stud and the matching of interior trim mounting holes are unreasonable. Due to the excessive depth of the internal groove of the mounting hole and the thin plate, the plate is overstretched and deformed during the tightening process, and finally the plate is tear and the studs fall off. Two solutions are proposed, such as changing the type of stud and changing the depth of recessed groove of interior trim mounting hole. The two solutions can almost completely avoid the occurrence of bolt detachment in the assembly shop and greatly improving the quality of the body in white. It provides new ideas for stud type selection and welding process quality control of white body stud welding.

Key words: Body in white; Stud welding; Stud fall off; Torque detection; Interior trim