Outer core manufacturing method, outer core, and reactor

Abstract

When an outer core that is to be mounted on a reactor is seen in plan, the outer core is a compact that has a plan-view shape in which a side of the outer core that is opposite to a facing side of the outer core, which faces the inner cores, has a smaller dimension in a width direction, which is parallel to a facing surface, than the facing side of the outer core. A method of manufacturing such an outer core includes a preparing step and a compacting step. In the preparing step, coated soft magnetic powder including multiple coated soft magnetic particles formed by coating soft magnetic particles with insulating coated films is prepared as raw-material powder of the outer core. In the compacting step, a compacting space, which is defined by a pillar-like lower punchand a tubular dieA, is filled with the coated soft magnetic powder and then the coated soft magnetic powder in the compacting spaceis compacted by the lower punchand a pillar-like upper punch, the lower punchand the tubular dieA being movable relative to each other. In the compacting step, the facing surface of the outer core is pressed by the upper punch