PROJECTION WELDING OF AN ALUMINUM SHEET

摘要

A projection coined onto a metal sheet (52), preferably an aluminum sheet, for projection welding the sheet to an adjacent metal sheet. The projection has a thickness greater than the thickness of the sheet on which it is formed. The wall (55) of the projection surrounds a first recess (1) and a second recess (63) is formed in a side of the sheet opposite the projection from which the metal cold flows to form the projection. A welding gun assembly having an improved low interia, fast response to the collapse of the projection welding the sheet having the projection to the adjacent sheet.