To prevent considerable heat loss from a preheated mold, to facilitate the treatment of a mold and to improve solidification controllability of molten material by preparing a casting chamber communicating to the bottom of a mold preheating chamber, an annular rotating chill member which is provided within the casting chamber and divides a central opening part, and a mold elevator.
The mold M is arranged within a mold heating furnace 50 and preheated up to a suitable casting temperature. A vacuum casting chamber 22 is evacuated with a vacuum pump P1 before preheating the mold M, the mold preheating chamber 20 which communicates to the vacuum casting chamber 22 via an opened shut-off valve 24 is also evacuated up to the same extent. After heating the mold M up to the casting temperature, the elevator 40 is descended, and the preheated mold is straight carried from the mold heating furnace 50 to the vacuum casting chamber 22. The shut-off valve 24 is closed to isolate the mold preheating chamber 20 from the vacuum casting chamber 22. Inserted material of metal or alloy is molten within a crucible 60. Molten material is poured into a receiving port MP in the preheated mold M which is set on the annular rotating chill member 70.
PRICE ALLEN R