Casting Method

Abstract

[OBJECT] To provide a method for casting with a gas permeable mold by gravity pouring, wherein melt is injected into only an intended cavity portion of a casting mold cavity and solidified. [MEANS FOR ATTAINING THE OBJECT] After pouring the melt having the volume substantially equal to that of the intended cavity portion to be filled with the melt, compressed gas is supplied from a sprue to inject the melt into the intended cavity portion and solidify the melt. The cavity may be decompressed before or after pouring according to need.

1 . A casting method for pouring melt having the weight volume ratio γ into a gas permeable mold, characterized by filling an intended cavity portion with the melt with supply of a compressed gas from a sprue and solidifying the melt after initiation of pouring of the melt having the volume substantially equal to that of the cavity portion intended to be filled with the melt in a cavity of said gas permeable mold. 
   
   
       2 . The casting method set forth in  claim 1 , characterized by supplying the compressed gas from the sprue to fill the intended cavity portion with the melt and solidifying the melt while maintaining the supply of said compressed gas. 
   
   
       3 . The casting method set forth in  claim 1 , wherein the applied pressure of the compressed gas is no less than the melt static pressure γH determined by the height H from a cavity inlet for introducing the melt into the intended cavity portion to the uppermost of said intended cavity portion. 
   
   
       4 . The casting method set forth in  claim 1 , wherein by filling the intended cavity portion with the melt with supply of the compressed gas from the sprue and using interrupting means so as to prevent the melt filled therein from flowing back from the vicinity of the boundary between said intended cavity portion and the other cavity portion. 
   
   
       5 . The casting method set forth in  claim 4 , further characterized by using means for cooling the vicinity of the boundary as the interrupting means so as to prevent the melt filled therein from flowing back. 
   
   
       6 . The casting method set forth in  claim 4 , further characterized by using means for mechanically blocking the vicinity of the boundary as the interrupting means so as to prevent the melt filled therein from flowing back. 
   
   
       7 . The casting method set forth in  claim 1 , wherein by decompressing the intended cavity portion to be filled with said melt before pouring the melt or after initiation of pouring of the melt. 
   
   
       8 . The casting method set forth in  claim 1  wherein the degree of decompression in the intended cavity portion to be filled with said melt is determined before pouring the melt or after initiation of pouring of the melt so as to bring the intended cavity portion into a decompressed state of a pressure no less than the absolute value of the melt static pressure γH determined by the height H from a cavity inlet for introducing the melt into the intended cavity portion to the uppermost of said intended cavity portion. 
   
   
       9 . The casting method set forth in  claim 1 , wherein the degree of decompression in the intended cavity portion to be filled with said melt is determined before pouring the melt or after initiation of pouring of the melt so as to bring the intended cavity portion into a decompressed state of a pressure less than the absolute value of the melt static pressure γH determined by the height H from a cavity inlet for introducing the melt into the intended cavity portion to the uppermost of the intended cavity portion.