スポット溶接の溶接条件の最適化

抄録

Spot welding is widely used for welding steel plates in the automobile body manufacturing process. During spot welding, melted metal sparks fly due to overheating and to variations in process conditions; these sparks lead to many losses in the manufacturing process. To prevent sparks, the present study attacked the problem of spot welding parameter design, taking process condition variations as noise, without pursuing quality characteristics. A feature of this study was that it evaluated cumulative energy supplied to the welding material per hour instead of evaluating weld quality by Hooke's law. In a confirmation experiment carried out under the optimum conditions obtained as a result, the gain of the S/N ratio was improved by the large value of 16.04 db,and estimates of robust noise-resistant welding conditions were obtained. Major effects of the reduction of sparks included increased weld area (improved weld strength), less rework, and reduced energy consumption.