Wound core

A wound core comprising:

• a hollow portion in a center;
• and
• a portion in which grain-oriented electrical steel sheets are stacked in a sheet thickness direction, the grain-oriented electrical steel sheets each having flat portions and bent portions continuing alternately in a longitudinal direction,
• the wound core formed into a rectangular shape having four corner portions including the bent portions, by stacking the grain-oriented electrical steel sheets, each obtained by folding, in layers and assembling the grain-oriented electrical steel sheets into a wound state in which a plurality of the grain-oriented electrical steel sheets are connected to each other via at least one joint portion for each winding and a total of bending angles of the bent portions in each of the four corner portions is 90 degrees, wherein
• corresponding bent portions of the grain-oriented electrical steel sheets are stacked in layers in the sheet thickness direction to form one bent region,
• in a side view of the wound core, in at least one arbitrary bent region in the four corner portions, when P represents, in an innermost grain-oriented electrical steel sheet in a plurality of the grain-oriented electrical steel sheets stacked in layers, an intersection point of an extending line extending along an inner surface of a flat portion to a corner portion and an extending line extending along an inner surface of a flat portion between bent portions forming the corner portion, Q represents, in an outermost grain-oriented electrical steel sheet in a plurality of the grain-oriented electrical steel sheets stacked in layers, an intersection point of an extending line extending along an outer surface of a flat portion to the corner portion and an extending line extending along an outer surface of a flat portion between bent portions forming the corner portion, and R represents a point where a straight line, the straight line passing through the intersection point represented by P and extending in a direction perpendicular to an extending direction of each of the plurality of the grain-oriented electrical steel sheets to the corner portion, intersects the outer surface of the outermost grain-oriented electrical steel sheet, an angle θ formed by a straight line PQ and a straight line PR satisfies 23°≤θ≤50°.