| 摘要 |
PURPOSE:To provide an extremely high surface magnetic flux density to a magnetic body by passing the magnetic fluxes generated in magnetizing coils through the ferromagnetic material without intervention of a nonmagnetic material thereby rendering directly surface multipolar anisotropy to the magnetic powder material and orienting the particles thereof. CONSTITUTION:A die 2 consists of a ferromagnetic material and is cut with the grooves of the number equal to the number of poles. Magnetizing coils 6 are embedded in the grooves and are shrinkage-fitted and fixed by means of nonmagnetic materials 7 to the die 2. A ferromagnetic powder material 5 is packed in the space formed of a top punch 3, a bottom punch 4 and a core 8. While electric current is conducted to the coils 6, the inside volume of said space is pressurized and compressed by the punch 3 and the punch 4, by which the inside volume is reduced and the material 5 is molded.
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