Pouring method, device, and cast in vacuum molding process

• US 7,757,746 B2
• Filed: 12/22/2008
• Issued: 07/20/2010
• Est. Priority Date: 04/01/2004
• Status: Active Grant

• Current Assignee: Sintokogio Limited
• Original Assignee: Sintokogio Limited
• Inventors: Suzuki, Hiroaki, Inoue, Takao, Makino, Hiroyasu, Oba, Takafumi, Tomita, Taketoshi, Takeda, Shizuo, Enomoto, Yoshinobu, Ando, Toshiaki, Mizuno, Kenji
• Primary Examiner(s): LIN, KUANG Y
• Application Number:
  US12/318,098
• Publication Number:
  US 20090114362A1
• Time in Patent Office: 575 Days
• Field of Search: 164 71- 72, 164/160.1, 164/160.2, 164/348
• US Class Current: 164/160.2
• CPC Class Codes: B22C 21/01 for vacuum-sealed moulding
• CPC Class Codes: B22C 9/03 formed by vacuum-sealed moulding
• CPC Class Codes: B22D 18/04 Low pressure casting, i.e. making use of pressures up to a few bars to fill the mould
• CPC Class Codes: B22D 23/06 Melting-down metal, e.g. metal particles, in the mould

Abstract

A pouring method and a device in a vacuum sealed process to produce a thin-wall cast by using a mold framing for the a vacuum sealed process, and a as-cast product using the pouring method are provided. The pouring method comprises 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 a mold half that has a molding surface; forming another 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 the negative pressure in the mold framing to take out a as-cast product, and further comprises the step of decompressing the molding cavity before pouring molten metal in the mated mold.

Claims

1. A molding device used in a vacuum sealed process, comprising:

upper and lower framings for receiving fills therein that act as upper and lower mold halves defining a molding cavity, each framing having an annular inner cavity in side walls thereof, the lower framing being mounted on a surface plate;

evacuating means located outside the upper and lower framings and connected in fluid communication with the annular inner cavities for evacuating the annular inner cavities;

a pair of annular cooling chambers formed in the annular inner cavities that surround matching planes of the upper and lower framings;

air nozzles detachably connected to the annular cooling chambers for spraying compressed air thereinto;

an air nozzle located under the surface plate at or near a center thereof for spraying compressed air onto an underside thereof;

means for measuring a degree of pressure reduction for at least one of the upper and lower framings during a period between a start and an end of the pouring; and

a controller for adjusting degrees of pressure reduction in the inside of the at least one framing mold half and in the molding cavity when the controller receives the detected degree of pressure reduction.