Patent ID: 9646751
Date: 2017-05-09
CPC Classifications: B22F,B30B,C22C,H01F

Claim:
1. A die apparatus for molding an arcuate magnet having polar-anisotropic orientation in a magnetic field, which comprises a die made of non-magnetic cemented carbide, which is arranged in a parallel magnetic field generated by a pair of opposing magnetic field coils; an arcuate-cross-sectional cavity having an inner arcuate wall, an outer arcuate wall and two side walls, which is disposed in said die, wherein the inner arcuate wall has a length which is shorter than that of the outer arcuate wall; a central ferromagnetic body arranged on the side of the outer arcuate wall of said cavity with distance from said cavity; and a pair of side ferromagnetic bodies symmetrically arranged on both side wall sides of said cavity with distance from said cavity; said cavity being arranged such that its radial direction at a circumferential center thereof is identical with the direction of said parallel magnetic field; the width of said central ferromagnetic body being smaller than the width of said cavity in a direction perpendicular to said parallel magnetic field, when viewed from above; and a pair of said side ferromagnetic bodies being arranged such that said cavity is positioned in a region sandwiched by facing surfaces of a pair of said side ferromagnetic bodies.