Method of manufacturing magnetic core, magnetic core, electromagnetic transducer, clock, and electronic device

Abstract

A magnetic core portion 16 , a residual base material portion 42 , and a connecting portion 43 are formed by pressing from a base material 40 . Notches 18 A are formed at a peripheral edge of the magnetic core portion 16 , which is bent in the direction of the plate thickness to form a temporary fixing portion 18 . When base materials 40 are overlapped to cut the magnetic core portions 16 from the connecting portion 43 , the magnetic core portions 16 are pressed in directions toward one another so that the temporary fixing portion 18 is filled between notches 18 A in the other magnetic core portion 16 , to fix temporarily the other magnetic core portions 16 . Since the magnetic core portions 16 are temporarily and simultaneously fixed by pressing in a cutting step normally carried out, the magnetic core portions can be temporarily fixed with ease.

1 . An electromagnetic transducer comprising: 
 a rotor including a permanent magnet;    a magnetic core including, 
 a magnetic core portion being formed in a predetermined shape by pressing a plurality of plate-shaped base materials comprising an amorphous metal, and  
 a temporary fixing portion being configured to fix temporarily said magnetic core portions,  
 said magnetic core portions being laminated to fix temporarily said magnetic core portions by said temporary fixing portion together with said pressing while forming said magnetic core portions, said magnetic core being arranged in a vicinity of said rotor to cause a magnetic flux to flow; and  
   a coil arranged in a vicinity of said magnetic core.    
   
   
       2 . The electromagnetic transducer according to  claim 1 , further comprising 
 a coil conducting substrate to connect said coil to an external circuit,    said substrate arranged on a surface of said magnetic core portion said surface is coated with adhesives.    
   
   
       3 . An electromagnetic transducer comprising: 
 a coil frame having an insulating material and having a recess in a concave shape in cross section formed therein, at least a part of said recess being opened;    a magnetic core including, 
 a magnetic core portion being formed in a predetermined shape by pressing a plurality of plate-shaped base materials comprising an amorphous metal, and  
 a temporary fixing portion being configured to fix temporarily said magnetic core portions,  
 said magnetic core portions being laminated to fix temporarily said magnetic core portions by said temporary fixing portion together with said pressing while forming said magnetic core portions, said magnetic core being accommodated in said recess; and  
   a coil wound around an outer periphery of said coil frame.    
   
   
       4 . The electromagnetic transducer according to  claim 3 , wherein 
 said recess is formed in a substantially rectangular shape having one line segment removed.    
   
   
       5 . The electromagnetic transducer according to  claim 3 , wherein 
 a circuit board on which an electric element is mounted is fixed to said coil frame.    
   
   
       6 . The electromagnetic transducer according to claims  3 ,  
     wherein 
 flanges projecting from said coil frame are formed at positions of the coil frame, corresponding to both ends of the coil.  
 
   
   
       7 . The electromagnetic transducer according to  claim 3 , wherein 
 said coil frame is formed with a plurality of fixing holes to allow screwing said electromagnetic transducer.    
   
   
       8 . An electronic device comprising: 
 an electromagnetic transducer having, 
 a rotor including a permanent magnet,  
 a magnetic core including, 
 a magnetic core portion being formed in a predetermined shape by pressing a plurality of plate-shaped base materials comprising an amorphous metal, and  
 a temporary fixing portion being configured to fix temporarily said magnetic core portions,  
 said magnetic core portions being laminated to fix temporarily said magnetic core portions by said temporary fixing portion together with said pressing while forming said magnetic core portions, said magnetic core being arranged in a vicinity of said rotor to cause a magnetic flux to flow; and  
 
 a coil arranged in a vicinity of said magnetic core.