PURPOSE: To obtain a high quality cast product having high strength and toughness without developing hot cracking and shrinkage hole by pulsatively and alternately applying the metal pressurizing force composed of high pressure and low pressure to molten metal elolidified in a cavity.
CONSTITUTION: Hydraulic pressure acted to a hydraulic cylinder 12a is controlled according to the deviation between a locus of the metal pressurizing force preset with the prescribed pressure variation width and the pressure variation frequency and the metal pressurizing force measured with a load cell 25 so that the metal pressurizing force follows the preset pressure locus. In a pressure model part 27, the metal pressurizing force composed of the prescribed high pressure and the prescribed low pressure having comparatively smaller in comparison with this high pressure to the molten metal 13 solidified in the cavity 6 are made to be alternately and periodically applied in the short time interval. For this purpose, the pressure variation width and the pressure variation frequency composed of the high pressure, low pressure and the intentional fixed value are set as a time-metal pressurizing force diagram or numeric values, and an output signal P according with these conditions is outputted.
YOSHIDA ATSUSHI
HIRAIZUMI ITSUKI
TONO TOORU
ADACHI MITSURU
