关键词: 自攻螺钉；扭矩；折叠缺陷；工艺优化

Abstract: Self-tapping screw is a fastener that does not require pre-tapping internal threads, in the self-tapping screw is screwed in by self-extrusion to form threads. In this paper, for the production process, self-tapping screws in the automatic tightening of frequent tightening not in place, jamming, overflow buckle and other failure problems, combined with the actual production of tightening equipment and process, the size of the screw and screw defect analysis. Through the optimization of the structure of the tightening gun, tightening programs, reduce the tightening defect rate. Through the screw processing mode and the composition of the screw thread analysis, to determine the root cause of the tightening failure, and screw thread processing process improvement. Through the full verification of the actual production process, after the change of the program and the improvement of screws to meet the actual production requirements. Process defects are almost completely eliminated in the tightening process, which improves the quality of the car body and production efficiency.

Key words: self-tapping screws; torque; folding defects; process optimization