Method for manufacturing a core mold for foam-molding and the core mold

Abstract

The invention provides a method for manufacturing a core mold for foam-molding by which a vivid design pattern can be formed on a foam-molded article and manufacturing costs can be lowered, and the core mold manufactured by such a method. A method for manufacturing a core mold for foam-molding 1 , provided with a concavo-convex pattern 5 on its mold surface 1 a for forming a design pattern 4 on the surface 3 a of a foam-molded article 3 , comprises the steps of forming a reverse concavo-convex pattern 7 that is reverse of the concavo-convex pattern 5 on the surface 6 a of a core mold making model 6 made of a conductive material having the same shape as the mold surface 1 a , and transferring the reverse concavo-convex pattern 7 by electric discharge machining to the mold surface 1 a , so as to form the concavo-convex pattern 5.

What is claimed is:  
     
         1 ) A method for manufacturing a core mold for foam-molding provided with a concavo-convex pattern on its mold surface for forming a design pattern on the surface of a foam-molded article, comprising the steps of: 
 forming a reverse concavo-convex pattern that is reverse of said concavo-convex pattern, on the surface of a core mold making model made of a conductive material having the same shape as said mold surface; and    transferring said reverse concavo-convex pattern by electric discharge machining to said mold surface, so as to form said concavo-convex pattern.    
     
     
         2 ) A method for manufacturing a core mold for foam-molding as set forth in  claim 1 , further comprising the step of executing a plurality of times said transference by electric discharge machining, each time changing relative positions of said core mold making model against said mold surface.  
     
     
         3 ) A method for manufacturing a core mold for foam-molding as set forth in  claim 1  or  2 , wherein said core mold making model is made of graphite.  
     
     
         4 ) A core mold for foam-molding manufactured by the method as set forth in  claim 1 , comprising a steam path disposed through a convex portion of said concavo-convex pattern.  
     
     
         5 ) The core mold for foam-molding comprising a plurality of adjoining components, wherein a core mold for foam-molding manufactured by the method as set forth in  claim 1  and/or the core mold for foam-molding as set forth in  claim 4  are employed as said components.  
     
     
         6 ) The core mold for foam-molding as set forth in  claim 5 , further comprising a steam path disposed at a joint of said components.