| 摘要 |
There is described a device and process for delivering a predetermined quantity of molten metal to a metal casting operation via metal transfer members, such as thermally heated pipes under a positive head to the shot size and delivery system wherein the device has a metal receiving chamber, a hydraulic ram for metal movement and an inert gas sweep capability. The ram chambers has only a nominal relationship to the volume of metal to be used to fill the mold, the true measurement of the volume being a factor of the pressure of the molten metal being delivered to the chamber and the time the molten metal is allowed to flow into the chamber before the ram is activated to force the metal under a definite predetermined pressure into the mold cavity. It is of course to be understood that the molten metal being delivered to the chamber under pressure flows into the mold cavity during the "loading" or "charging" step since there is no resistance to the free flow of the metal until the ram starts it movement and closes off the molten metal inlet. Associated with the chamber is an inert gas source which is introduced through the inert gas inlet positioned such that the gas will flow into the chamber and hence into the mold cavity during the period prior to the introduction of molten metal into the chamber and the mold cavity and throughout the period prior to the ram closing off the molten metal inlet and pressurizing the chamber and the mold cavity to force the metal into the cavity under sufficient pressure to insure the smallest detail of the die is adequately filled with the metal.
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