Insert-molding method and and device therefor

Abstract

The present invention relates to a method of producing an insert-molding product in which an insert product 2 is covered with a synthetic resin by arranging the insert product 2 in a cavity 11 of a mold 10, holding the insert product by a holding pin 12, pouring a molten synthetic resin 3 into the cavity 11, and retracting the holding pin 12. The moving pin 13 is provided adjacent to the holding pin 12. After the cavity 11 is filled with the synthetic resin 3, the holding pin 12 is retracted and the moving pin 13 is moved in the direction of the cavity 11 to extrude and introduce the synthetic resin 3 into the space where the holding pin 12 used to be positioned.

1 . An insert-molding method in which an insert product is arranged in a cavity of a mold and held by at least one holding pin, a molten synthetic resin is poured into said cavity, and said holding pin is retracted to obtain an insert-molding product which said insert product is covered with said synthetic resin, wherein said holding pin is retracted after said cavity is filled with said synthetic resin which is extruded and introduced into space where said holding pin was located.  
     
     
         2 . An insert-molding method according to  claim 1 , wherein at least one moving pin is placed adjacent to said holding pin, and said moving pin is moved in the direction of the cavity to extrude and fill said synthetic resin into the space where said holding pin used to be located.  
     
     
         3 . An insert-molding method according to  claim 2 , wherein said moving pin is arranged to surround said holding pin and to be concentric therewith.  
     
     
         4 . An insert-molding method according to  claim 2 , wherein said moving pin is arranged parallel with said holding pin.  
     
     
         5 . An insert-molding method according to  claim 2 , wherein said moving pin is arranged at right angles with said holding pin.  
     
     
         6 . An insert-molding method according to  claim 2 , wherein said holding pin contains a heater.  
     
     
         7 . An insert-molding method according to  claim 2 , wherein said mold has a guide hole for guiding said moving pin in the direction of the cavity, an end of said moving pin is located on the inside of an open end of said guide hole when said cavity is being filled with said synthetic resin, and after said cavity is filled with said synthetic resin, said moving pin is moved in the direction of the cavity while retracting said holding pin.  
     
     
         8 . A molding device, for producing an insert-molding product in which an insert product is covered with a synthetic resin, comprising a mold having a cavity for molding, and a holding pin retractably provided in said mold to hold the insert product, wherein said mold has a moving pin that retractably moves in the direction of the cavity adjacent to said holding pin.  
     
     
         9 . A molding device according to  claim 8 , wherein said moving pin is arranged to surround said holding pin and to be concentric therewith.  
     
     
         10 . A molding device according to  claim 8 , wherein said moving pin is arranged parallel with said holding pin.  
     
     
         11 . A molding device according to  claim 8 , wherein said moving pin is arranged at right angles with said holding pin.  
     
     
         12 . A molding device according to  claim 8 , wherein said holding pin contains a heater.  
     
     
         13 . A molding device according to  claim 8 , wherein said mold has a guide hole for guiding said moving pin in the direction of the cavity.