DIFFERENTIAL PRESSURE CASTING METHOD

PURPOSE:To quicken filling velocity of molten metal without developing spout flow and to obtain a casting having high strength by filling up the molten metal supplied from plural gate parts into cavity in a die while rotating. CONSTITUTION:By applying the pressurized force into a molten metal holding furnace 8, the molten metal 10 heated in a crucible 7 is supplied into the cavity 6 in the die 2. The pressurized molten metal 10 in the crucible 7 is ascended in a lower stoke 11 and at the time of reaching to intermediate stokes 12 from upper end part of the lower stoke 11, the molten metal 10 is supplied into the cavity 18 at end face of rim part in the die 2 through each gate part 13 while rotating along the shape of the intermediate stokes 12, that is, along spiral shape. At first, after filling up the molten metal 10 to the bottom part of the cavity 18, the molten metal 10 is flowed while rotating toward the same rotating direction on the horizontal plane along wall face at the cavity bottom part and the rim part. Then, the molten metal 10 is shifted upward while rotating as joining the molten metal flows at the bottom part of the cavity 18 of the end face of the rim part and also shifted to center of a disk part and filling-up is completed. By this method, the molten metal is smoothly filled up without enclosure of foreign matter and misrun of the molten metal.