Sand-mold molding method and sand-mold molding apparatus

Abstract

A sand-mold molding method for producing a molded article obtained by packing foamed sand may include stirring a binder with an aggregate to form foamed sand; forming a cavity via clamping a metallic mold closed; packing the foamed sand into the cavity of the metallic mold and then heating and solidifying the foamed sand; and opening the metallic mold partially to provide a gap in the metallic mold while maintaining the cavity.

1 . A sand-mold molding method for producing a molded article obtained by packing foamed sand, comprising:
 stirring a binder with an aggregate to form foamed sand;   forming a cavity via clamping a metallic mold closed;   packing the foamed sand into the cavity of the metallic mold and then heating and solidifying the foamed sand; and   opening the metallic mold partially to provide a gap in the metallic mold while maintaining the cavity.   
     
     
         2 . The sand-mold molding method according to  claim 1 , wherein opening the metallic mold further includes reducing a mold clamping force of the metallic mold so that the gap is provided in the metallic mold by a counterforce from the metallic mold. 
     
     
         3 . The sand-mold molding method according to  claim 1 , wherein the gap in the metallic mold ranges from 0.22 mm to 0.36 mm. 
     
     
         4 . A sand-mold molding apparatus comprising:
 a metallic mold defining a cavity via clamping the metallic mold closed;   a mold clamping device configured to open and close the metallic mold;   a packing device configured to pack a foamed sand into the cavity, wherein the foamed sand is foamed by stirring a binder with an aggregate; and   a heating device configured to heat the foamed sand within the cavity,   wherein the mold clamping device partially opens the metallic mold after the foamed sand has been packed into the cavity to define a gap in the metallic mold while maintaining the cavity.   
     
     
         5 . The sand-mold molding apparatus according to  claim 4 , wherein the mold clamping device reduces a mold clamping force so that the gap is provided in the metallic mold by a counterforce from the metallic mold. 
     
     
         6 . The sand-mold molding apparatus according to  claim 4 , wherein the gap in the metallic mold ranges from 0.22 mm to 0.36 mm. 
     
     
         7 . The sand-mold molding apparatus according to  claim 5 , wherein the gap in the metallic mold ranges from 0.22 mm to 0.36 mm. 
     
     
         8 . The sand-mold molding apparatus according to  claim 4 , wherein the metallic mold includes a stationary mold and a movable mold. 
     
     
         9 . The sand-mold molding apparatus according to  claim 8 , wherein the mold clamp device clamps and secures the stationary mold to the movable mold. 
     
     
         10 . The sand-mold molding apparatus according to  claim 8 , wherein the mold clamping device includes an air cylinder that drives the movable mold. 
     
     
         11 . The sand-mold molding apparatus according to  claim 10 , further comprising a switch valve configured to regulate a supply of air to the air cylinder. 
     
     
         12 . The sand-mold molding apparatus according to  claim 10 , wherein the air cylinder includes a reciprocating rod driven by an air supply. 
     
     
         13 . The sand-mold molding apparatus according to  claim 8 , wherein the gap in the metallic mold ranges from 0.22 mm to 0.36 mm. 
     
     
         14 . The sand-mold molding apparatus according to  claim 8 , wherein the mold clamping device reduces a mold clamping force so that the gap is provided in the metallic mold by a counterforce from the metallic mold. 
     
     
         15 . The sand-mold molding apparatus according to  claim 14 , wherein the gap in the metallic mold ranges from 0.22 mm to 0.36 mm. 
     
     
         16 . The sand-mold molding apparatus according to  claim 15 , wherein the heating device heats the metallic mold to a temperature ranging from 150° C. to 300° C. 
     
     
         17 . The sand-mold molding apparatus according to  claim 4 , wherein the metallic mold includes at least one discharge passage for discharging fluid from the cavity. 
     
     
         18 . The sand-mold molding apparatus according to  claim 4 , wherein the heating device heats the metallic mold to a temperature ranging from 150° C. to 300° C. 
     
     
         19 . The sand-mold molding method according to  claim 1 , wherein heating and solidifying the foamed sand includes heating the metallic mold to a temperature ranging from 150° C. to 300° C. 
     
     
         20 . The sand-mold molding method according to  claim 2 , wherein the gap in the metallic mold ranges from 0.22 mm to 0.36 mm.