US-12623413-B2 - Reinforcing member, structural member, and method of manufacturing the same

US12623413B2US 12623413 B2US12623413 B2US 12623413B2US-12623413-B2

Abstract

A reinforcing member includes a plate-shaped member that is made of a fiber-reinforced resin in which a continuous fiber is used as a reinforcement fiber and that has a first surface and a second surface. The plate-shaped member includes an outer circumferential portion that defines an outer edge of the plate-shaped member, a convex portion that is convex on a side of the first surface in an area inside the outer circumferential portion, and a plurality of concave portions that are concave on the side of the first surface in an area inside the convex portion.

Inventors

Koichiro Saito
Yuki Hirata
Ryozo OIWA
Keiju OGURI

Assignees

NIKKISO CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20231215
Priority Date: 20221215

Claims (12)

1 . A reinforcing member comprising a plate-shaped member that is made of a fiber-reinforced resin in which a continuous fiber is used as a reinforcement fiber and that has a first surface and a second surface, the plate-shaped member including: an outer circumferential portion that defines an outer edge of the plate-shaped member; a convex portion that is convex on a side of the first surface in an area inside the outer circumferential portion; and a plurality of concave portions that are concave on the side of the first surface in an area inside the convex portion, wherein a radius of curvature of the first surface and the second surface of each of the plurality of concave portions in a cross-sectional view orthogonal to the outer edge is configured to be 20 mm or more.
2 . The reinforcing member according to claim 1 , wherein the plurality of concave portions are arranged in a lattice shape or a radial shape.
3 . The reinforcing member according to claim 1 , wherein an outer edge of the convex portion has a shape in which four corners of a quadrangle are arc-shaped, and wherein an outer edge of each of the plurality of concave portions has a shape in which four corners of a quadrangle are arc-shaped.
4 . The reinforcing member according to claim 3 , wherein a bottom portion of each of the plurality of concave portions has a shape of a quadrangle or a shape produced by rounding four corners of a quadrangle.
5 . The reinforcing member according to claim 1 , including: a continuous fiber sheet formed by weaving a plurality of continuous fibers extending in a first direction and a plurality of continuous fibers extending in a second direction that intersects the first direction.
6 . The reinforcing member according to claim 1 , further comprising: a rib made of a fiber-reinforced resin in which a discontinuous fiber is used as a reinforcement fiber and extending from the first surface or the second surface.
7 . The reinforcing member according to claim 6 , wherein the rib includes a first rib that extends from the first surface in an area inside at least one of the plurality of concave portions.
8 . The reinforcing member according to claim 6 , wherein the rib further includes a second rib that extends from the second surface in an area inside the convex portion.
9 . The reinforcing member according to claim 8 , wherein the second rib connects between a bottom portion of at least one of the plurality of concave portions and the outer circumferential portion.
10 . The reinforcing member according to claim 8 , wherein the second rib connects between bottom portions of two of the plurality of concave portions.
11 . The reinforcing member according to claim 1 , wherein a resin weight content of the fiber-reinforced resin is 50% or less.
12 . A structural member comprising: the reinforcing member according to claim 1 ; and a main body member joined to the outer circumferential portion of the reinforcing member and to a bottom portion of each of the plurality of concave portions, wherein a cavity is provided between the reinforcing member and the main body member.

Description

RELATED APPLICATION Priority is claimed to Japanese Patent Application No. 2022-200051, filed on Dec. 15, 2022, the entire content of which is incorporated herein by reference. BACKGROUND 1. Field of the Disclosure The present disclosure relates to a reinforcing member, a structural member, and a method of manufacturing the same. 2. Description of the Related Art In recent years, structural members in which a fiber-reinforced resin is used have been adopted to reduce the weight of automobiles and aircraft. For example, aircraft parts are formed by heating and pressure molding a prepreg produced by impregnating a reinforcement fiber with a resin. A method is proposed that forms a partial incision in a continuous fiber included in a prepreg to configure an open incision in which the incision is open in order to pressure mold a complex three-dimensional structure from a plate-shaped prepreg (see, for example, JP2020-55447). In the related art described above, there is concern that the strength is reduced by forming an incision in the continuous fiber. SUMMARY The present disclosure addresses the issue described above, and a purpose thereof is to provide a lightweight and highly rigid structural member. A reinforcing member according to an embodiment of the present disclosure includes a plate-shaped member that is made of a fiber-reinforced resin in which a continuous fiber is used as a reinforcement fiber and that has a first surface and a second surface, the plate-shaped member including: an outer circumferential portion that defines an outer edge of the plate-shaped member; a convex portion that is convex on a side of the first surface in an area inside the outer circumferential portion; and a plurality of concave portions that are concave on the side of the first surface in an area inside the convex portion. Another embodiment of the present invention relates to a structural member. The structural member includes: the reinforcing member according to the embodiment; and a main body member joined to the outer circumferential portion of the reinforcing member and to a bottom portion of each of the plurality of concave portions, wherein a cavity is provided between the reinforcing member and the main body member. Still another embodiment of the present invention relates to a manufacturing method. The method includes: providing a prepreg sheet, produced by impregnating a continuous fiber with a resin, on a mold for molding a plate-shaped member, the plate-shaped member including an outer circumferential portion that defines an outer circumference of the plate-shaped member having a first surface and a second surface, a convex portion that is convex on the side of the first surface in an area inside the outer circumferential portion, and a plurality of concave portions that are concave on the side of the first surface in an area inside the convex portion; and heating and pressurizing the prepreg sheet by using the mold to mold the plate-shaped member made of a fiber-reinforced resin. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described, by way of example only, with reference to the accompanying drawings that are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several figures, in which: FIG. 1 is a perspective view schematically showing the configuration of the structural member according to the embodiment; FIG. 2 is a perspective view schematically showing the configuration of the reinforcing member according to the embodiment; FIG. 3 is a perspective view schematically showing the configuration of the reinforcing member according to the embodiment; FIG. 4 is a top view schematically showing the configuration of the reinforcing member according to the embodiment; FIG. 5 is a lateral cross-sectional view schematically showing the configuration of the reinforcing member according to the embodiment; FIG. 6 is a top view schematically showing the lattice frame shape of the apex portion; FIGS. 7A, 7B schematically show a method of forming a prepreg sheet; FIG. 8 schematically shows a method of molding the reinforcing member according to the embodiment; FIGS. 9A, 9B schematically show the orientation direction of the prepreg sheets; FIG. 10 is a top view showing the reinforcing member according to the embodiment; FIG. 11 schematically shows a joint between the main body member and the reinforcing member; FIG. 12 is a perspective view schematically showing the configuration of the reinforcing member according to a variation; FIG. 13 is a perspective view schematically showing the configuration of the reinforcing member according to the variation; FIG. 14 schematically shows a method of molding the reinforcing member according to the variation; and FIG. 15 is a lateral cross-sectional view schematically showing the configuration of a structural member according to another embodiment. DETAILED DESCRIPTION The invention will now be described by reference to the preferred