Casting unit and casting method

Abstract

The casting unit solves problems of a conventional casting unit, in which a non-consumable sprue is connected to a lost foam gate attached to a core, such as troublesome assembly and post-treatment after casting. In the casting unit, a plurality of cores having molten metal inlets, which open into the surfaces of the cores and through which a molten metal is caused to flow into cavities formed in the cores, and a lost foam pattern, which forms a sprue between each of the molten metal inlets and a sprue cup, in which a molten metal is poured, and which has a peripheral surface coated with a refractory mold coating agent, are embedded in dry sand except for the sprue cup, and the cores, which are adjacent to each other, are connected to each other so that the plurality of cores are integrated.

1 . A casting unit, comprising: a plurality of cores having molten metal inlets, which open into the surfaces of the cores and through which a molten metal is caused to flow into cavities formed in the cores; and a lost foam pattern forming a sprue between each of the molten metal inlets and a sprue inlet, in which a molten metal is poured, the lost foam pattern having a peripheral surface coated with a refractory mold coating agent, wherein the cores and the lost foam pattern are embedded in dry sand except for the sprue inlet,
 the casting unit is characterized in that the cores, which are adjacent to each other, are connected to each other so that the plurality of cores are integrated.   
     
     
         2 . The casting unit according to  claim 1 , wherein the cores, which are adjacent to each other, are connected to each other by an adhesive or concavo-convex engagement. 
     
     
         3 . The casting unit according to  claim 1 , wherein each of the cores is constituted by a pair of core molds. 
     
     
         4 . The casting unit according to  claim 1 , wherein the cores are constituted by shell molds, self-hardening molds or combination of the both. 
     
     
         5 . The casting unit according to  claim 4 , wherein the cores are constituted by the shell molds, and
 wherein the cores, which are adjacent to each other, are connected to each other by bringing softened layers of the shell molds, in which resin included in the shell sand is softened, into tight contact with each other and hardening the softened layers.   
     
     
         6 . The casting unit according to  claim 1 , wherein inner wall faces of the cavities formed in the cores are coated with a refractory mold coating agent. 
     
     
         7 . The casting unit according to  claim 1 , wherein the cores, the sprue, the sprue inlet and the dry sand are inserted in a metal flask, and a tubular member having a plurality of through-holes, whose diameter is smaller than a grain diameter of the dry sand, is inserted in the dry sand so as to collect and discharge a decomposition gas, which is generated by contact between the cores, the lost foam pattern and the molten metal. 
     
     
         8 . A casting method being performed in the casting die of any one of  claims 1 - 7 , said method comprising the steps of: plasticizing the dry sand, by applying vibration, after pouring the molten metal into the sprue inlet; and
 pulling a cast body, in which runners, which are formed by filling the sprue formed by the lost foam pattern with the molten metal, and products, which are formed by filling the cavities of the cores with the molten metal, are integrated, out from the dry sand.