METHOD FOR OPERATING HOLDING FURNACE FOR PRESS FEEDING OF MOLTEN METAL

摘要

PURPOSE:To prevent the oxidation of a low melting metal by charging the heat resistant oil of the volume required for covering the front surface of the low melting metal in a furnace body into the furnace body so that the contact of the front surface of the low melting metal with air is prevented. CONSTITUTION:A heater 2 is mounted to the furnace body 3 and a heat insulating material 1 is applied thereon. The low melting metal S of the molten state is supplied into the furnace body 3 up to the upper position of a pressurizing cylinder 5 and the heat resistant oil O completely covers the front surface. An extrusion cylinder 10 is actuated to lower a pressurizing piston 12 by which the molten metal is press fed into a pressurizing cylinder 5, from which the molten metal is press fed via a nozzle 8 into a metallic mold 7 on the outside of the machine. The molten metal is held for a prescribed period of time to cast a core made of the low melting metal. The molten metal is introduced into the pressurizing cylinder and the above-mentioned operation is repeated when the pressurizing piston is reset to the home position by reverse actuating the extrusion cylinder. The oxidation of the low melting metal is prevented in this way and the weight loss thereof is obviated.