| 摘要 |
PROBLEM TO BE SOLVED: To weld stacked works by forming a gap between the works without using inserted members. SOLUTION: A holding mechanism 18 is composed of an upper roller part 96 and a lower roller part 98, the upper roller part 96 is provided with a first roller 102 and a second roller 104, and the lower roller part 98 is provided with a third roller 112 and a fourth roller 114. The first roller 102 is tapered toward the outer side of the radial direction and the tip part 103 of the roller is cuspidate. The first roller 102, the second roller 104, the third roller 112, and the fourth roller 114 are so formed that a relation d2+d4<d1+d3 is satisfied, where d1, d2, d3 and d4 stand for the diameters of the first roller 102, the second roller 104, the third roller 112 and the fourth roller 114, respectively. |
