Patent ID: 8922323
Filing Date: 2014-12-30
Classification: H01F,Y10T

Abstract:
1. An outer core manufacturing method by which an outer core for a reactor is manufactured by performing compacting, the reactor including a coil, a pair of inner cores, and a pair of outer cores, the coil being formed by connecting a pair of coil elements to each other that are arranged side by side, the coil elements being formed by helically winding a wire, the pair of inner cores being individually disposed inside the coil elements, the pair of outer cores being exposed outside the coil, the pair of outer cores being connected to the inner cores to form an annular core together with the inner cores, the outer cores each having a facing surface that includes a connection area connected to the inner cores, the facing surface of one of the outer cores facing the other outer core with the inner cores interposed therebetween, each of the outer cores having the facing surface and an opposite surface, wherein the opposite surface is placed opposite to the facing surface and the opposite surface has a smaller area than the facing surface area, the method comprising: a preparing step of preparing coated soft magnetic powder as raw-material powder of the outer core, the coated soft magnetic powder including a plurality of coated soft magnetic particles formed by coating soft magnetic particles with insulating coated films; and a compacting step of filling a compacting space, which is defined by a pillar-like first punch and a tubular die, with the coated soft magnetic powder and then compacting the coated soft magnetic powder in the compacting space by using the first punch and a pillar-like second punch that is disposed so as to face the first punch, the first punch and the die being movable relative to each other, wherein, in the compacting step, the facing surface of the outer core is pressed by the second punch and the opposite surface of the outer core is pressed by the first punch, and the tubular die has a through hole in which the dimension in the width direction of the tubular die on a first-punch side of the tubular die is smaller than that on a second-punch side of the tubular die.