| 摘要 |
PURPOSE:To make gas venting sure by providing detecting line valves and evacuation line valves to an evacuation path of a cavity, and closing the evacuation line valve by the inertial force of a molten metal, then closing the evacuation line valve with a time delay. CONSTITUTION:The detecting line valve 1 and the evacuation line valve 2 are juxtaposed to the evacuation path of a gas venting device and a valve means 11 is provided to one side part of the detecting valve body 4 so that the valve means 11 makes an opening operation by the closing operation of the detecting valve 3. The valve 3 moves upward and the detecting line valve 1 is closed when the molten metal filled into the cavity 53 collides against a valve head 3a upon arrival at the evacuation path 54. The valve means 11 is then opened and the evacuation line valve 2 is closed with the time delay by air. The inflow of the molten metal into the evacuation line valve 2 is thoroughly prevented by the above-mentioned method, by which the gas venting is smoothly and surely executed. |
