Pressurizing control method and pressurizing control system for low-pressure casting

摘要

In a low-pressure casting in which molten metal is introduced into a cavity of a casting mold under a pressure applied to the surface of the molten metal according to a preset reference pressurizing pattern, the reference pressurizing pattern is corrected when that the cavity has been filled with molten metal is detected and the pressure applied to the molten metal surface is controlled according to the reference pressurizing pattern after the correction. The pressure difference between a set pressure at a predetermined time in the reference pressurizing pattern after the correction and a set pressure at the corresponding time in the reference pressurizing pattern before the correction, is calculated and a set pressure for the period up to the time the cavity is filled with molten metal in the reference pressurizing pattern for the next casting cycle is corrected on the basis of the calculated pressure difference.