	US 7,500,507 B2
	Method and device for pouring molten metal in vacuum molding and casting
Hiroyasu Makino, Toyokawa (Japan); Taketoshi Tomita, Toyokawa (Japan); Takafumi Oba, Toyokawa (Japan); Hiroaki Suzuki, Toyokawa (Japan); Kenji Mizuno, Toyokawa (Japan); Toshiaki Ando, Toyokawa (Japan); Yoshinobu Enomoto, Toyokawa (Japan); Takao Inoue, Toyokawa (Japan); and Shizuo Takeda, Toyokawa (Japan)
Assigned to Sintokogio, Ltd., Aichi (Japan)
Appl. No. 11/547,541 PCT Filed Apr. 01, 2005, PCT No. PCT/JP2005/006481 § 371(c)(1), (2), (4) Date Oct. 02, 2006, PCT Pub. No. WO2005/095022, PCT Pub. Date Oct. 13, 2005.
Claims priority of application No. 2004-108911 (JP), filed on Apr. 01, 2004; application No. 2004-132681 (JP), filed on Apr. 28, 2004; and application No. 2005-028325 (JP), filed on Feb. 04, 2005.
Prior Publication US 2007/0209771 A1, Sep. 13, 2007
Int. Cl. B22C 9/03 (2006.01)

U.S. Cl. 164—7.2 [164/160.2]

2 Claims

1. A pouring method in a vacuum sealed process comprising the steps of:

sealingly covering the surface of a pattern plate by a shielding member;

placing a mold framing on the shielding member and then putting a fill that does not include any binder in the mold framing;

sealingly covering an upper surface of the fill and then evacuating an inside of the mold framing to suck the shielding member to the fill to shape the shielding member;

removing the pattern plate from the shielding member, thereby forming an upper mold half that has a molding surface;

forming a plurality of apertures in a part of the shielding member that contacts with the molding surface of the upper mold half;

forming a lower mold half in a similar way and mating the mold halves to define a molding cavity;

pouring molten metal in the molding cavity;

and releasing a negative pressure in the mold framing to take out an as-cast product,

wherein the method further comprises the steps of:

measuring a degree of pressure reduction for at least one of the upper and lower mold halves during a period between the start and end of the pouring of the molten metal in the molding cavity; and decompressing one mold half and the the molding cavity so that Pm=1-75 KPa, Pc=4.95 KPa, and Pc−Pm=3-94 Kpa, where Pm and Pc are a pressure within the one mold half and a pressure in the molding cavity, respectively.