| 摘要 |
This invention relates to a delivery assembly for delivering molten metal, to a die-casting machine. The system includes a die-casting liquid metal injector with an operative piston having a cylindrical shuttle valve within the assembly and providing for a lower end portion of the assembly to communicate directly to a reservoir of molten metal, particularly corrosive molten metal such as liquid aluminum or the like. In that respect, the injector surface having contact with the corrosive liquid metal are preferably made of a fine ceramic or composite thereof and in the preferred embodiment by partially stabilized Zirconia. The piston, during its molten metal charging stroke, moves the shuttle away from closing off the inflow conduit which communicates to the liquid metal reservoir supply and the internal cavity defined by the assembly is charged with liquid metal. On the compressive stroke of the piston, the shuttle first moves forward to close off the inflow channel insuring no leakage of molten metal back to the supply reservoir and at the same time, the metal within the piston chamber now communicates with an outflow orifice directly to a nozzle which injects liquid metal directly into a mold cavity. A fixed charge for the cavity is achieved. |
