| 摘要 |
PURPOSE:To prevent the development of micro porosity and shrinkage cavity by filling up molten metal into a cavity, narrowing the middle part in a gate as shifting a pressurizing punch arranged to each gate and also generating the pressurized molten metal flow toward the cavity. CONSTITUTION:The molten metal filled up into the cavity is held to under higher pressure than the pressure during filling, and by working a hydraulic cylinder 54 of the lower die 11, each pressurizing punch 52 is held to the ascending position. The middle part in each gate 16 is narrowed, and also the pressurized molten metal flow (b) toward the first cavity C1 is generated, and after that the molten metal is perfectly solidified. In this way, thermal conducting action to the molten metal, which exists in the first cavity C1 side of each gate 16, from a runner 15 side is almost intercepted, and so the development of micro porosity at the connecting through part of the gate for a cylinder block material is prevented. At the same time, by generation of the pressurized molten metal flow (b), the molten metal at the first cavity C1 side of the gate 16 is pressurized, to prevent the development of shrinkage cavity.
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