Casting die inspection method and casting device

An inspection method of a casting device including a casting mold, wherein:

• the casting mold includes a cavity portion configured to create a cast product, a first gas flow path that includes a first end connected to the cavity portion, and a shut-off valve configured to shut off the first gas flow path;
• and
• the casting device includes a vacuum drawing portion configured to draw a vacuum inside the cavity portion, via the first gas flow path,
• the inspection method comprising:
• acquiring an ultimate pressure inside the cavity portion at a timing when a prescribed vacuum drawing time has passed from when vacuum drawing inside the cavity portion was started;
• acquiring a pressure increase inside the cavity portion, which has occurred during a prescribed stoppage time, at a timing when the prescribed stoppage time has passed from when, after vacuum drawing inside the cavity portion, the vacuum drawing was stopped in a state of the shut-off valve being kept open;
• evaluating a first sealing property of the casting device based on the ultimate pressure;
• and
• evaluating a second sealing property of the casting device based on the pressure increase,
• wherein:
• the casting mold includes:
• a fixed mold,
• a sleeve attached to the fixed mold,
• a plunger arranged inside the sleeve and having a plunger tip at a tip end, and
• a molten metal holding portion formed in the fixed mold, connecting the sleeve to the cavity portion, and configured to hold molten metal to be injected into the cavity portion;
• the inspection method comprises sealing an inside of the cavity portion from outside by inserting a plug member for air-tight sealing into the molten metal holding portion between the plunger tip and the cavity portion, performed before the acquiring of the ultimate pressure;
• the acquiring of the ultimate pressure includes correcting the ultimate pressure based on a difference in internal volume of the molten metal holding portion, the internal volume communicating with the cavity portion, between a timing at which the plug member has been inserted into the molten metal holding portion and a timing at which injection of molten metal into the cavity portion is started without the plug member being inserted into the molten metal holding portion;
• and
• the acquiring of the pressure increase includes correcting the pressure increase based on the difference in internal volume.