Patent ID: 8677608
Filing Date: 2014-03-25
Classification: H02K,Y10T

Abstract:
1. A method for manufacturing an iron core having a structure, in which first split core pieces adjoining one another in the circumferential direction and second split core pieces adjoining one another in the circumferential direction are mutually rotatable, by forming a first annular core member by punching a plurality of first split core pieces in an annular shape out of a sheet of magnetic plate material, the first split core pieces each including: a yoke part which includes a first end of a first shape oriented in a first circumferential direction and a second end of a second shape, which is different from the first shape and is oriented in a second circumferential direction, and which has a rotation uneven part arranged on the surface of the first end; and a tooth part projecting inwardly in the radial direction from the yoke part, such that the first end of the yoke part of each first split core piece comes in contact with the second end of the yoke part of its circumferentially adjoining first split core piece, by forming a second annular core member by punching a plurality of second split core pieces in an annular shape out of a sheet of magnetic plate material, the second split core pieces each including: a yoke part which includes a third end of the second shape oriented in the first circumferential direction and a fourth end of the first shape oriented in the second circumferential direction, and which has a rotation uneven part arranged on the surface of the fourth end; and a tooth part projecting inwardly in the radial direction from the yoke part, such that the third end of the yoke part of each second split core piece comes in contact with the fourth end of the yoke part of its circumferentially adjoining second split core piece, and by concentrically laminating the first annular core member and the second annular core member such that each first end of the first shape is overlaid with its corresponding fourth end of the first shape, and connecting the overlaid portions by the rotation uneven parts, the method comprising: a first process of, on the first annular core member, making cut lines of the first shape or the second shape with respect to the first ends that are at a reference position, and at a position rotated by a predetermined angle from the reference position, and also making cut lines of the first shape with respect to the first ends that are at circumference positions other than the reference position, and the position rotated by the predetermined angle from the reference position; a second process of, on the second annular core member, making cut lines of the first or the second shape with respect to the fourth ends that are at the reference position, and at the position rotated by the predetermined angle from reference position, and also making cut lines of the first shape with respect to the fourth ends that are at circumference positions other than the reference position, and the position rotated by the predetermined angle from the reference position; a third process of forming the rotation uneven parts on the surfaces of the first ends of the yokes of the first annular core member and on the surfaces of the fourth ends of the yokes of the second annular core member, at the circumference positions other than either of the reference position and the position rotated by the predetermined angle from the reference position; and a fourth process of laminating the first annular core member and the second annular core member while rotating the first annular core member or the second annular core member by the predetermined angle such that one of the first ends in the circumferential direction of the first annular core member, the first end having no rotation uneven part processed, is positionally identical in the laminating direction with one of the fourth ends in the circumferential direction of the second annular core member, the fourth end having no rotation uneven part processed.