| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a permanent magnet, capable of efficiently manufacturing a permanent magnet excellent in magnetic anisotropy.SOLUTION: In a method for manufacturing a permanent magnet, a mandrel is inserted into a through hole of an extrusion mold from the other opening, and a preform filled in the through hole from one opening is pressed by inserting a pressing punch into the through hole from the one opening, and the preform is extruded into a filling space between an outer face of the mandrel and an inner face of the through hole to mold a primary molding having a bottomed portion, and the bottomed portion is cut out from the primary molding to obtain a square cylindrical secondary molding 24 opened on front and back sides in an extrusion direction, and when the secondary molding 24 receives force in a direction opposite to a pair of stress-concentrated portions 28, the secondary molding 24 is divided at four stress-concentrated portions 28 into four permanent magnets 18 each having a rectangular cross section. |
