| 摘要 |
PURPOSE:To prevent deterioration of a silicone rubber mold for casting and to enable repetitive use by casting the melt of an Al alloy while passing cooling water to the rear side of the silicone rubber mold for casting. CONSTITUTION:A pattern OA of an impeller is fixed to the center of a master mold constituted of casting molds 1A, 2A and 3A and liquid silicone rubber 4A is poured into the spacing constituted of the master mold and the pattern OA. The pattern OA is pulled upward to form a cavity part 8A of a casting mold after a silicone rubber mold 7A is obtd. upon solidification of the silicone rubber. The mold 1A is then removed and in turn a reinforcing metallic mold 9A worked with a cooling water passage 10A on the surface is mounted in the lower part of the mold 7A. A casting mold 11A for a riser is mounted in place of the mold 3A and while cooling water is passed to the cooling water passage 10A between the mold 7A and the mold 9A, the melt 12A of the Al alloy is poured into the mold. The casting is removed from the mold upon solidification of the melt 12A and when the casting is finished, the Al alloy impeller is obtd. |
