Patent ID: 7758946

Claim:
A three-dimensional fiber structure, comprising: a fiber lamination including a plurality of fiber layers laminated on one another, the fiber layers being at least biaxially oriented, each fiber layer being formed of a continuous fiber or a fabric texture, the fiber lamination being a three-dimensional plate, the fiber lamination including a bent portion, a first flat portion, and a second flat portion, the first flat portion and the second flat portion sandwiching the bent portion, and the first flat portion, the bent portion, and the second flat portion are continuous; and a connection yarn arranged to cross the fiber layers, wherein the connection yarn obliquely crosses the fiber layers at the first flat portion, and wherein the connection yarn is perpendicular to the fiber layers at the second flat portion, wherein the bent portion defines a centerline of curvature and an imaginary plane that is perpendicular to the centerline of curvature, wherein the cross-sectional shape of the bent portion at the imaginary plane includes an outer path, which is outside of the bent portion, and an inner path, which is inside of the bent portion, wherein the cross-sectional shape of the first flat portion at the imaginary plane includes a first flat outline connecting with the outer path of the bent portion, and a second flat outline connecting with the inner path of the bent portion, wherein an oblique line is defined to be parallel to the connection yarn at the first flat portion and to cross a boundary between the outer path of the bent portion and the first flat outline, the oblique line crossing the second flat outline of the first flat portion at a sliding point, wherein a length of the outer path of the bent portion is equal to a sum of a length of the inner path of the bent portion and a length of a straight path between the inner path and the sliding portion.