To solve the problem that a low-pressure metal casting furnace needs very high running cost for using a large quantity of expensive inert gas and exhausting the inert gas from the low-pressure metal casting furnace for every time when completing the pour of molten metal into a metallic mold.
In the low-pressure metal casting furnace, in which a pressurizing chamber 2 is adjacently set and communicatable with a molten metal holding chamber 1 and a molten metal shut-down valve 4 is arranged at a portion allowing the molten metal holding chamber 1 to communicate with the pressurizing chamber 2 and a communicating tube 6 for allowing the tip end part at downstream side of the pressurizing chamber 2 to communicate with a molten metal discharging hole 5, a float 10 vertically moved by an electric motor type cylinder 9 for changing the rotating movement of a servo-motor 7 into a straight line movement through a screw mechanism 8 is arranged to be virtically movable in the inner part of the pressurizing chamber 2 and further, an introducing tube 11 for supplying inert gas by exhausting the air in this pressurizing chamber 2, is faced to the upper part of the pressurizing chamber 2.
SHIOSE FUMIKAZU
MURATA YUTAKA
