| 摘要 |
The movable upper portion of a mould is positioned in a first position. Molten metal is forced upwardly into the mould cavity through an opening in a stationary lower mould portion. The upper portion is lowered to a position below the first position to force molten metal into all regions of the mould cavity and to force excess metal back into the furnace. A stop is moved downwardly through an upper opening defined in the upper mould portion to close the lower opening. The upper portion is lowered to a second position, and an external downward force is applied on the upper portion to compress the metal within the mould. The method is particularly suitable for forming vehicle wheel rim castings with reduced subsequent surface processing.
|
