| 摘要 |
PURPOSE:To perform venting in dies surely by injecting molten metal in the state that the spool valve of a gas exhaust passage is held open, and, upon ending of exhausting of the gas in the cavity, moving the valve onto the axial line with the melt to be injected having entered the cavity thereby shutting off the gas exhaust passage. CONSTITUTION:There is a spool valve 14 at the end part of the venting groove 10 led from the cavity 7 at the releasing plane part of dies 3, 4. This valve 14 moves in its axial line direction. Here, if the valve 14 is opened and molten metal is injected into the cavity 7 through a pouring hole 8, the gas in the cavity 7 is exhausted to the outside of the dies 3, 4 through a vent way 9, a by-pass 15 and a gas exhaust passage 12. Further, when the injection progresses, the molten metal ascends in the venting groove 10, and collides against the under surface of the valve 14, thereby lifting the valve in its axial line direction. At the same time, part of the molten metal enters the by-pass 15, and in due course of time, the ascending of the valve 14 is stopped by a stopper 18, by which the part between the by-pass 15 and the gas exhaust passage 12 is closed and the molten metal is dammed up. During this time, the gas in the by-pass 15 is exhausted as well. |
