US 9,808,858 B2
Method to improve riser feedability for semi-permanent mold casting of cylinder heads
Qigui Wang, Rochester Hills, MI (US); and Christopher D. Cogan, Clarkston, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM Global Technology Operations LLC, Detroit, MI (US)
Filed on Oct. 15, 2015, as Appl. No. 14/884,259.
Prior Publication US 2017/0106434 A1, Apr. 20, 2017
Int. Cl. B22C 9/08 (2006.01)
CPC B22C 9/088 (2013.01) 10 Claims
OG exemplary drawing
 
1. A method of improving riser feedability in semi-permanent mold casting, the method comprising:
providing a first receptacle fluidly connected to a mold cavity;
providing a second receptacle fluidly connected to a riser;
delivering molten metal to the first receptacle;
conveying the molten metal that has been delivered to the first receptacle into the mold cavity through a sprue;
terminating delivery of the molten metal to the first receptacle when the mold cavity reaches a predetermined fill level;
delivering molten metal to the second receptacle upon terminating delivery of molten metal to the first receptacle; and conveying the molten metal that has been delivered to the second receptacle into the riser via a spillway.