Casting method and casting mold

Abstract

A casting method and casting mold able to easily produce a casting having an island and connecting portion at a high quality. A casting ( 1 ) having a body ( 11 ), a opening ( 12 ) provided so as to pass through the body, an island ( 121 ) arranged separated from the body in the opening, and a connecting portion ( 22 ) joining the island and body is cast using a casting mold ( 2 ). The casting mold is provided with a body gate ( 311 ) connected to a body cavity for forming the body and a opening gate ( 321 ) connected to an island/connecting portion cavity ( 32 ) for forming the island and the connecting portion. The body gate and opening gate are connected to a runner ( 33 ) through body pin gates ( 312 ) and opening pin gates ( 322 ).

1 . A casting method for casting a product having a body, a opening provided so as to pass through the body, an island provided separated from the body in the opening, and a connecting portion joining the island and body using a mold having a cavity corresponding to the shape of the product, 
 the mold being provided with a body gate connected to a body cavity for forming the body in the cavity and a opening gate connected to an island/connecting portion cavity for forming the island and connecting portion in the opening in the cavity;    the body gate and opening gate being connected to a runner for introducing a melt into them; and    the melt fed into the runner being filled in the cavity through the body gate and the opening gate.    
     
     
         2 . A casting method as set forth in  claim 1 , wherein: 
 the mold has a three-part structure of a fixed mold, intermediate mold, and movable mold;    the fixed mold and the intermediate mold are provided between them with said runner;    the intermediate mold and movable mold are provided between them with said cavity, said body gate, and said opening gate;    the intermediate mold is provided with a body pin gate connecting the runner and the body gate and a opening pin gate connecting the runner and the opening gate; and    the melt sent into the runner is filled in the cavity through the body pin gate and body gate and through the opening pin gate and opening gate.    
     
     
         3 . A casting method as set forth in  claim 2 , comprising: 
 filling the melt, then moving said intermediate mold and movable mold to separate said fixed mold and said intermediate mold;    moving said movable mold to separate said intermediate mold and movable mold, cutting a runner casting formed in said runner from pin gate castings formed in said body pin gate and said opening pin gate, and releasing said pin gate castings from said intermediate mold;    then releasing the casting from said movable mold in the state with the pin gate castings attached.    
     
     
         4 . A casting method as set forth in  claim 2  or  3 , wherein said intermediate mold and said movable mold have between them a balance runner provided at least at part of the section between said body pin gate and said body gate and at least at part of the section between said opening pin gate and said opening gate and wherein at least part of said melt is supplied from said body pin gate through said balance runner to said body gate and from said opening pin gate through said balance runner to said opening gate.  
     
     
         5 . A casting method as set forth in any one of  claims 1  to  4 , wherein said casting is a front end panel for an automobile and has a body having a surround, a opening formed inside said surround, a part mount as an island arranged in said opening, and stays supporting said part mount as said connecting portion.  
     
     
         6 . A casting method as set forth in  claim 5 , wherein said part mount mounts a motor, fan, or pulley.  
     
     
         7 . A casting mold for casting a product having a body, a opening provided so as to pass through the body, an island provided separated from the body in the opening, and a connecting portion joining the island and body, 
 the mold having a three-part structure of a fixed mold, intermediate mold, and movable mold;    the intermediate mold and movable mold being provided between them with a cavity having a body cavity for forming the body and an island/connecting portion cavity for forming the island and the connecting portion in the opening, a body gate connected to the body cavity, and a opening cavity connected to the island/connecting portion cavity;    the fixed mold and the intermediate mold being provided between them with a runner for introducing melt into the body gate and the opening gate;    the intermediate mold being provided with a body pin gate connecting the runner and the body gate and a opening pin gate connecting the runner and the opening gate; and    the melt sent into the runner being filled in the cavity through the body pin gate and body gate and through the opening pin gate and opening gate.    
     
     
         8 . A casting mold as set forth in  claim 7 , wherein a plurality of at least one of said body gate and said opening gate are provided.  
     
     
         9 . A casting mold as set forth in  claim 7  or  8 , wherein said body pin gate and/or said opening pin gate is reversely tapered to expand in channel area from said fixed mold toward said movable mold or from said movable mold toward said fixed mold.  
     
     
         10 . A casting mold as set forth in any one of  claims 7  to  9 , wherein said body pin gate and/or said opening pin gate is provided at an cavity insert detachably inserted in an cavity insert setting hole provided in said intermediate mold.  
     
     
         11 . A casting mold as set forth in any one of  claims 7  to  10 , wherein a draft of at least part of an inner wall of said cavity at said movable mold side is not more than 1°.  
     
     
         12 . A casting mold as set forth in any one of  claims 7  to  11 , wherein said movable mold is provided with a plurality of ejector pins for pushing out the casting formed in the cavity from said cavity.  
     
     
         13 . A casting mold as set forth in  claim 12 , wherein said ejector pins are provided to abut against said casting near body pin gates and/or opening pin gates.  
     
     
         14 . A casting mold as set forth in any one of  claims 7  to  11 , wherein said intermediate mold and said movable mold have between them a balance runner provided at least at part of the section between said body pin gate and said body gate and at least at part of the section between said opening pin gate and said opening gate.  
     
     
         15 . A casting mold as set forth in  claim 14 , wherein said movable mold is provided with a plurality of ejector pins for pushing out the casting formed in the cavity from said cavity and wherein said ejector pins are provided to abut against said balance runner near the positions of body pin gates connected to said balance runner.  
     
     
         16 . A casting mold as set forth in  claim 15 , wherein a projection projecting out in the direction of the intermediate mold is provided near a joining portion of said body pin gate and/or opening pin gate and said balance runner.  
     
     
         17 . A casting mold as set forth in any one of  claims 7  to  16 , wherein an end part formed at said movable mold in said body pin gate and/or opening pin gate is provided with a distributer projecting out toward an inlet of said body pin gate and/or said opening pin gate.  
     
     
         18 . A casting mold as set forth in  claim 17 , wherein said distributer is shaped with a draft of at least part of not more than 1°.  
     
     
         19 . A casting mold as set forth in any one of  claims 7  to  18 , wherein a portion where said body pin gate and/or said opening pin gate connects with said runner is provided with a constricted part reduced in channel area.  
     
     
         20 . A casting mold as set forth in any one of  claims 7  to  19 , wherein said runner is branched into a body runner for introducing said melt into said body pin gate and a opening runner for introducing said melt into said opening pin gate.  
     
     
         21 . A casting mold as set forth in  claim 20 , wherein said body runner and said opening runner are adjusted in inside diameter so that the rates of filling said melt in them become substantially equal.  
     
     
         22 . A casting mold as set forth in  claim 20  or  21 , wherein said opening runner has a shape similar to the shape of said island.  
     
     
         23 . A casting mold as set forth in any one of  claims 7  to  22 , wherein said cavity is connected to a pressure reducing means for reducing the pressure in said cavity.  
     
     
         24 . A casting mold as set forth in any one of  claims 7  to  23 , wherein said casting is a front end panel for an automobile and has a body having a surround, a opening formed inside said surround, a part mount as an island arranged in said opening, and stays supporting said part mount as said connecting portion.  
     
     
         25 . A casting mold as set forth in  claim 24 , wherein said part mount mounts a motor, fan, or pulley.  
     
     
         26 . A casting method for casting a product having a body, a opening provided so as to pass through the body, an island provided separated from the body in the opening, and a connecting portion joining the island and body using a mold having a cavity corresponding to the shape of the product, 
 the mold having a body cavity for forming the body in the cavity, an island/connecting portion cavity for forming the island and the connecting portion in the opening in the cavity, and a opening gate connected to the island/connecting portion cavity, the opening gate being connected to a runner introducing melt into it;    the melt fed into the runner being filled in the cavity through the opening gate.    
     
     
         27 . A casting mold for casting a product having a body, a opening provided so as to pass through the body, an island provided separated from the body in the opening, and a connecting portion joining the island and body, 
 the mold having a three-part structure of a fixed mold, intermediate mold, and movable mold;    the intermediate mold and movable mold being provided between them with a cavity having a body cavity for forming the body and an island/connecting portion cavity for forming the island and the connecting portion in the opening and a opening cavity connected to the island/connecting portion cavity;    the fixed mold and the intermediate mold being provided between them with a runner for introducing melt into the opening gate;    the intermediate mold being provided with a opening pin gate connecting the runner and the opening gate; and    the melt sent into the runner being filled in the cavity through the opening pin gate and opening gate.