| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas vent valve device for a casting mold which can be rapidly closed. SOLUTION: The device is provided with a valve housing 2, a gas vent chamber 6 in the housing 2, a gas vent hole communicating with the chamber 6 in the housing 2, and a gas vent valve having a valve closing member 20 in the housing 2. The member 20 can move between an opening position at which the chamber 6 communicates with an ambient air by the hole 7 and a closing position at which the chamber 6 is sealed from the ambient air by the hole 7. In a hydraulic pressure chamber 13 having a wall portion 14, the portion 14 is elastically deformed with an excessive pressure generated inside the chamber 13 so that the member 20 is locked at the opening position thereof by friction. At this time, since an air pressure is applied to a valve plate member 23 connected to the member 20 to press the member 20 in its closing direction, a sensor 30 senses a casting material entering into the hole 7, and reducing the excessive pressure in the chamber 13 a little enables to close the valve 1 rapidly.
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