SPOT WELDING METHOD OF COMPOSITE METALLIC PLATE

摘要

PURPOSE:To perform spot welding of a composite metallic plate while maintaining satisfactory weld strength without damaging thermally the intermediate layer thereof by interposing a member for current conduction between the composite metallic plate and the other base metal for welding and uniting said plate and base metal to one body by welding. CONSTITUTION:A blind hole 20 arriving at a blank material plate 4b is provided to the desired position of the composite metallic plate 4 by cutting part of one blank material plate 4a and part of the intermediate layer 4c. The member 21 for current conduction consisting of a metal weldable to the base metal is fitted into the hole 20. A similar hole 23 is formed to the other composite metallic plate 3 as well and the length of the member 21 is made equal to or slightly longer than the depth of both holes 20, 23 and is fitted into the hole 23 of the other plate 3 then both plates 4, 3 are superposed on each other in the case of welding the composite metallic plates to each other. Local large current is passed to electrodes while a movable electrode 1 is pressed to weld the contact part by contact resistance. The member 21 is interposed in the same way and the spot welding is executed in the case of welding the plate 4 to the other metallic member 7.