| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing in which an impeller having high quality and high reliability can stably be formed by preventing the generation of a casting defect, in the case of cast-forming the impeller by a suction casting process using a gypsum mold. SOLUTION: In the method for manufacturing the impeller, a cavity having a space-shape corresponding to the impeller-shape is demarcated with the gypsum member having gas-permeability and a chiller; and the gypsum mold having a sprue part at the position faced to the chiller is introduced in a chamber, with which the outer periphery at the portion demarcating blade part of the impeller-shape in the gypsum mold becomes the reduced-pressure space; and while controlling the pressure with a reduced-pressure controlling part set in the chamber, the pressure in this cavity is reduced through the gypsum mold by reducing the pressure in the reduced-pressure space; and the casting is performed into the cavity by sucking the molten metal from the sprue part. COPYRIGHT: (C)2009,JPO&INPIT
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