JPS6422489A - Method for welding hollow cylindrical members - Google Patents

Abstract

PURPOSE:To prevent a weld crack taking place on a weld bead by fitting members to be welded one of which at least is hollow cylindrical on the fitting surface and forming the abutting surface on the tapered surfaces each other and sticking these fast to each other to weld the tapered surfaces together with the high energy heat source. CONSTITUTION:One member 1 to be welded at least of two members 1 and 2 to be welded is formed to the hollow cylindrical member and both the members 1 and 2 formed to the hollow cylindrical member and both the members 1 and 2 to be welded are fitted on the fitting surface 12 and butted on the abutting surface 13. At this time, the abutting surface 13 is formed to a taper in the direction to approach the outside surface as it proceeds to the edge 14 of the member 1 to be welded. Both the tapered surfaces 13 of both the members 1 and 2 to be welded are butted so as to be stuck to each other. Next, a laser beam 3 from the high energy density heat source such as the laser beam, etc., is projected on a welding surface zone made of the tapered surfaces 13 and the members 1 and 2 to be welded close to the welding surface are molten and solidified and both the members to be welded are joined at the tapered surface 13 part. The weld bead 15 with the depth of penetration and bead width of relatively small sizes is formed and the thermal contraction stress to act on the bead at the time of solidifying is relaxes and averaged and the occurrence of the weld crack can be reduced by forming the welding surface to the tapered surfaces 13.