Aluminum casting method and mold

Abstract

An aluminum casting method is for pouring an aluminum molten metal ( 12 ) pumped up by an electromagnetic pump ( 20 ) into a die ( 50 ). A thickness of a powder demolding agent applied to the die ( 50 ) is set to be thinner than that of a demolding agent for a gravity die casting. A temperature of the die immediately before the molten metal is poured is controlled so as to fall within a range that is between 110° C. to 250° C. A temperature of the molten metal when poured is controlled to be a value obtained by adding 20° C. to 55° C. to a liquidus-line temperature of the aluminum.

1 - 2 . (canceled) 
     
     
         3 . A die utilized for an aluminum casting of pouring an aluminum molten metal pumped up by an electromagnetic pump into the die,
 wherein a thickness of a powder demolding agent applied to the die is set to be thinner than a demolding agent for a gravity die casting,   wherein a temperature of the die immediately before the molten metal is poured is controlled so as to fall within a range that is between 110° C. to 250° C., and   wherein a temperature of the molten metal when poured is controlled to be a value obtained by adding 20° C. to 55° C. to a liquidus-line temperature of the aluminum,   the die being for casting a cast that comprises:   a center portion;   a first projecting portion projecting from the center portion; and   a second projection portion projecting from the center portion in an opposite direction to the first projecting portion,   the die comprising:   a pouring gate provided at a bottom surface;   a main sprue runner extended upright from the pouring gate;   a first sprue runner branched from the main sprue runner;   a first cavity to which a molten metal is supplied from the first sprue runner, and which forms the first projection portion;   a second sprue runner branched from the main sprue runner;   a second cavity to which the molten metal is supplied from the second sprue runner and which forms the second projecting portion;   a column portion that is extended so as to go through the first cavity and the second cavity; and   a conical portion which is connected to a tip of the column portion and which has a vertex, wherein an outer diameter of a bottom surface off the conical portion and an outer diameter of a tip surface of the column portion are designed so as to be consistent with each other,   wherein the molten metal that passes through the main sprue runner is divided into, at the vertex, the first sprue runner and the second sprue runner along a conical surface of the conical portion and the column portion, and   wherein:   the cast is a knuckle;   the center portion is an axle portion provided with an axle hole;   and   the axle hole is formed by the column portion in the casting.   
     
     
         4 . The die according to  claim 3 , the die comprising a degassing portion to discharge a gas remaining in a cavity,
 wherein the degassing portion is provided with a vent hole with a dimension that is between 30 μm to 80 μm.   
     
     
         5 . The die according to  claim 4 , wherein:
 the degassing portion is a cylindrical body fitted in the die;   the cylindrical body comprises a bottom portion that faces the cavity; and   the bottom portion is provided with the vent hole.   
     
     
         6 . The die according to  claim 5 , wherein the vent hole is a slit with a width that is between 30 μm to 80 μm. 
     
     
         7 . The die according to  claim 6 , wherein a plurality of the slits is provided in the bottom portion so as to be in parallel with each other. 
     
     
         8 . The die according to  claim 5 , wherein the cylindrical body also serves as a product extrusion pin to separate a cast from the die.