| 摘要 |
PURPOSE: A manufacturing method of a piston for a compressor is provided to improve joint strength between a head body part and blocking members manufactured by die casting. CONSTITUTION: A material for manufacturing a single head piston is provided with a body member(162) and the blocking members(164). The body member(162) and blocking members(164) are cast by a pore-free method, and the gas quantity in material is made 5 cc/100 g or less. Each blocking member(164) is fitted into the opening of the body member(162). Both members are rotated while irradiating electron beams on a weld line with an end face(180) of the body member(162) and a shoulder face(194) of the blocking member(164), as welded faces, and a part near the welded faces is fused to joint both members. Since the gas quantity in the material of the body member(162) and blocking member(164) is suppressed low, a welded bead with few blowholes can be obtained. The electron beams are bifurcated halfway, and the irradiation point of each electron beam moves describing a spiral locus. Consequently, even if blowholes are once formed in the welded bead during welding, the blowholes are fused being irradiated again with electron beams. |
