| 摘要 |
PURPOSE:To execute welding of triplex base metals with one process and to maintain adequately the quality and strength of a weld zone by pressing reinforcing and auxiliary base metals which are thick and are different in thickness to the respective surfaces of a thin basic base metal by shifting the welding projections thereof and welding the base metals. CONSTITUTION:The respective welding projections 6, 4 of the auxiliary base metal 5 and the reinforcing base metal 3 are disposed to the top and bottom surfaces of the basic base metal 1 in contact therewith in the case of subjecting, for example, the inlet pipe coupling part of a fuel tank for a vehicle to projection welding. The projections 4, 6 are positioned in the state of shifting the same by a size L from each other. Electrodes for the purpose of projection welding are disposed above and below the contact parts of the base metals 1, 3, 5 and a specified value of pressurizing force is exerted continuously, then electricity is conducted thereto at and for a required current value and time, for instance, three times including, two pauses. |
