PRESSURIZED CASTING METHOD

PURPOSE:To hardly develop casting defect and to make close of metallurgical structure in the obtd. casting by causing pressurized gas to flow into fine gap formed at between molten metal filled up in cavity and coating material layer on the cavity surface and pressurizing and cooling molten metal from surface side. CONSTITUTION:After filling up the molten metal in the cavity 15, at the time of storing the molten metal in pouring basin part 10c in a fixed sand mold 10, the pressurizing cover 12 is descended to seal the sprue 10b. Successively, by introducing the pressurized gas into inner part of the pressurizing cover 12 from a pressurized gas introducing passage in the pressurizing cover 12, the molten metal surface is pressurized and on the other hand, the pressurized gas is supplied into recessed part 14d in a movable sand mold 14 from a pressurized gas supplying passage 18. The molten metal in the cavity 15 is pressed to both cavity surfaces 10a, 14c with the pressurized force of gas. On the other hand, the pressurized gas applied to the recessed part 14d in the movable sand mold 14 is caused to flow upward to the fine gap formed at between the coating material layer 16 on the cavity surface 14c in the movable sand mold 14 and the molten metal, and further, caused to flow downward to the fine gap formed at between the coating material layer 11 on the cavity surface 10a in the fixed sand mold 10.