Vacuum-assisted counter gravity casting apparatus with valve to prevent flow of melt from mold

摘要

Casting apparatus for the vacuum-assisted, countergravity casting of a melt comprises a porous, gas permeable casting mold including a mold cavity and a melt inlet communicating the mold cavity to a lower mold portion adapted to engage an underlying source of melt and a vacuum box defining a vacuum chamber confronting the casting mold for evacuating the mold cavity when the lower mold portion and the underlying source of the melt are engaged. A valve member is disposed on the mold in an open position relative to the melt inlet to permit the melt to be drawn upwardly therethrough into the mold cavity when the lower mold portion and the source are engaged with the mold cavity evacuated and is movable to a closed position relative to the melt inlet after the mold cavity is filled with the melt to close off the melt inlet to prevent the melt from flowing out of the mold cavity when the lower mold portion and the source are subsequently disengaged. The valve member is movable from the open position to the closed position by a valve moving mechanism carried on the vacuum box. The mold is engaged with the melt source only long enough to fill the mold cavity with the melt to thereby provide a significant reduction in the overall casting cycle time.