| 摘要 |
PURPOSE:To cast a thin-walled casting having thick walled parts stably without a defect, by forming the thick walled part of a cavity of a casting mold which is enclosed with hermetically closing members and has heat retaining property and air permeability, and a chiller and charging molten metal into the cavity while evacuating the inside of the mold. CONSTITUTION:A casting mold 10 which has a casting port 22, is enclosed by hermetic members such as a flask body 32, metallic foil 36 and the like, consists of gypsum materials or the like and has heat retaining property and air permeability, forms a cavity 16 consisting of thin walled parts 18 and a thick walled part 20, and forms a part of the thick walled part 20 of a chiller 12. The inside of said mold 10 is connected to an evacuating device (not shown) through evacuating holes 26 formed in the chiller 12, an evacuating vessel 14 and a nozzle 30. With such constitution, molten metal is charged through the port 22 while the air is evacuated from the vessel 14. When the port 22 is closed, the inside of the cavity is evacuated quickly and the molten metal is filled instantaneously and surely into the parts 18. In the part 20, the molten metal is solidified directionally by the chiller 12, and the generation of shrinkage defects is obviated. |
