Tilting Gravity Casting Method for manufacturing Knuckle

Abstract

A tilting gravity casting apparatus, a die includes a ladle that stores a molten metal and the molten metal is poured through a pouring gate into a cavity of the die when the die is tilted. The cavity accommodates a cylindrical protrusion for forming a closed-end hole in a bearing support portion of a knuckle, and the cavity has a pressing boss portion located along an axial line of the cylindrical protrusion. Before a die tilt step of tilting the die is completed, a press step of pressing the molten metal in the pressing boss portion by using a pressing pin and a pouring gate block step of blocking the pouring gate with a block member are initiated.

1 . A tilting gravity casting method for manufacturing a knuckle by using a tilting gravity casting apparatus in which a die includes a ladle that stores a molten metal and the molten metal is poured through a pouring gate into a cavity of the die when the die is tilted,
 with the cavity accommodating a cylindrical protrusion for forming a closed-end hole in a bearing support portion of the knuckle, and   with the cavity having a pressing boss portion located along an axial line of the cylindrical protrusion,   the method comprising:   a die tilt step of tilting the die;   a press step of pressing the molten metal in the pressing boss portion by using a pressing pin; and   a pouring gate block step of blocking the pouring gate with a block member,   wherein the press step and the pouring gate block step are initiated before the die tilt step is completed.   
     
     
         2 . The tilting gravity casting method according to  claim 1 ,
 wherein after the press step is initiated, the pouring gate block step is initiated.   
     
     
         3 . The tilting gravity casting method according to  claim 1 ,
 wherein the molten metal is a semi-solidified slurry made of an aluminum alloy, and   a solid phase ratio of the semi-solidified slurry in the ladle ranges from 5 to 10%.   
     
     
         4 . The tilting gravity casting method according to  claim 2 ,
 wherein the molten metal is a semi-solidified slurry made of an aluminum alloy, and   a solid phase ratio of the semi-solidified slurry in the ladle ranges from 5 to 10%.   
     
     
         5 . A tilting gravity casting apparatus for manufacturing a knuckle, in which a die includes a ladle that stores a molten metal and the molten metal is poured through a pouring gate into a cavity of the die when the die is tilted, the apparatus comprising:
 a block member that blocks the pouring gate; and   a pressing pin that presses the molten metal,   wherein the cavity accommodates a cylindrical protrusion for forming a closed-end hole in a bearing support portion of the knuckle,   the cavity has a pressing boss portion located along an axial line of the cylindrical protrusion, and   the pressing pin presses the molten metal in the pressing boss portion.