| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing apparatus of a radial anisotropic ring magnet in which magnetic field gradient in the axial direction of a cavity is reduced and deflection of magnetic powder is reduced during orientation. <P>SOLUTION: A manufacturing apparatus of a radial anisotropic ring magnet includes: a pair of coils 10A and 10B which generates magnetic fields opposing to each other in an axial direction; and a mold 20 which is arranged between the pair of coils 10A and 10B and has a core 22 and a die 21 arranged around the core 22 and in which a cavity 28 to which magnetic powder is supplied is formed between the core 22 and the die 21. The core 22 consists of a ferromagnetic body, an insulator and a non-magnetic body, a portion 22A, in which the magnetic resistance of an area corresponding to an area from the core portion thereof to the central portion of the cavity 28 in the axial direction is smaller than the magnetic resistance of areas corresponding to the both end portions of the cavity 28 in the axial direction, is provided, and cavity length is made longer than the axial length of the area of the core 22 having a small magnetic resistance. <P>COPYRIGHT: (C)2012,JPO&INPIT |
