Vacuum casting apparatus and method using the same

A vacuum casting method comprising the steps of:

• (a) disposing a mold having a runner and a mold cavity communicating with said runner in a vacuum vessel having at least one opening at the bottom thereof so that an opening of said runner is positioned under said opening of said vacuum vessel;
• (b) disposing a suction recess having an opening on the top surface of said mold in a vicinity of a portion of said mold cavity which is most distant from said opening of said runner and which is lastly filled with a melt of casting material so that a distance between the bottom of said suction recess and said portion of said mold cavity is smaller than a distance between the outer surface of said mold and any other portions of said mold cavity;
• and
• (c) evacuating said mold by operating a vacuum means connected to said vacuum vessel thereby rapidly filling said mold cavity with said melt.

A vacuum casting apparatus comprising:

• (a) a vacuum vessel having at least one opening at the bottom thereof;
• (b) a mold disposed within said vacuum vessel and having a mold cavity formed therein, a runner having an opening under said opening of said vacuum vessel and extending along at least partially the side of said mold cavity, said mold cavity communicating with said runner through a plurality of filling passages, and a suction recess having an opening on the top surface of said mold and disposed in a vicinity of a portion of said mold cavity which is most distant from said opening of said runner and which is lastly filled with a melt of casting material;
• and
• (c) a vacuum means communicating with said vacuum vessel;
• whereby said mold cavity is evacuated through said suction recess by operating said vacuum means more rapidly than mold portions other than said mold cavity to rapidly fill said mold cavity with said melt.

A vacuum casting method comprising the steps of:

• (a) disposing in a vacuum vessel having at least one opening at the bottom thereof a mold having a mold cavity formed therein and a runner extending along at least partially the side of said mold cavity, said mold cavity communicating with said runner through a plurality of filling passages, so that an opening of said runner is positioned under said opening of said vacuum vessel;
• (b) disposing a suction recess having an opening on the top surface of said mold in a vicinity of a portion of said mold cavity which is most distant from said opening of said runner and which is lastly filled with a melt of casting material so that a distance between the bottom of said suction recess and said portion of said mold cavity is smaller than a distance between the outer surface of said mold and any other portions of said mold cavity;
• and
• (c) evacuating said mold by operating a vacuum means connected to said vacuum vessel thereby rapidly filling said mold cavity with said melt.