Reinforcing member, structural member, and method for manufacturing the same

Abstract

To provide a structural member with lightweight and excellent rigidity.SOLUTION: A reinforcing member 14 is made of a fiber-reinforced resin using continuous fibers as reinforcing fibers and has a plate-shaped member 16 having a first side 16a and a second side 16b. The plate-shaped member 16 has a peripheral portion 20 defining an outer edge 18 of the plate-shaped member 16, a convex portion 22 inside the peripheral portion 20 that is convex on the first side 16a, and a plurality of concave portions 24 inside the convex portion 22 that are concave on the first side 16a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a reinforcing member, a structural member, and methods for manufacturing these.

Background Art

[0002] In recent years, for weight reduction of automobiles, aircraft, etc., structural members using fiber-reinforced resins have been increasingly adopted. For example, aircraft parts are formed by heat-press molding a prepreg in which reinforcing fibers are impregnated with resin. In order to press-mold a complex three-dimensional structure from a flat prepreg, a method has been proposed in which partial cut portions are formed in continuous fibers included in the prepreg, and the cut portions are open cut portions in an open state (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above prior art, there is a concern about a decrease in strength due to forming cut portions in continuous fibers.

[0005] The present invention has been made in view of such problems, and an exemplary object thereof is to provide a lightweight and highly rigid structural member.

Means for Solving the Problems

[0006] A reinforcing member according to an aspect of the present invention is composed of a fiber-reinforced resin using continuous fibers as reinforcing fibers, and includes a plate-like member having a first surface and a second surface. The plate-like member includes an outer peripheral portion that defines the outer edge of the plate-like member, a convex portion where the first surface side is convex inside the outer peripheral portion, and a plurality of concave portions where the first surface side is concave inside the convex portion.

[0007] Another aspect of the present invention is a structural member. The structural member includes a reinforcing member in one aspect, and a main body member joined to the outer peripheral portion of the reinforcing member and the bottom of each of the plurality of concave portions, and a cavity is provided between the reinforcing member and the main body member.

[0008] Yet another aspect of the present invention is a manufacturing method. This method includes a step of disposing a prepreg sheet impregnated with resin in continuous fibers on a mold for forming a plate-shaped member including an outer peripheral portion defining the outer edge of a plate-shaped member having a first surface and a second surface, a convex portion having a convex first surface side inside the outer peripheral portion, and a plurality of concave portions having a concave first surface side inside the convex portion, and a step of heating and pressing the prepreg sheet using the mold to form a reinforcing member including a plate-shaped member composed of a fiber-reinforced resin.

[0009] According to an aspect of the present invention, a lightweight and highly rigid structural member can be provided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description, the same reference numerals are given to the same elements, and redundant descriptions are omitted as appropriate. For the sake of understanding the description, the dimensional ratios of the respective components in each drawing do not necessarily match the actual dimensional ratios.

[0012] Fig. 1 is a perspective view schematically showing the configuration of a structural member 10 according to the embodiment. The structural member 10 is a blocker door attached to the outer periphery of an aircraft engine. The blocker door is a movable member for blocking the bypass airflow of the engine and causing reverse injection. In the embodiment, the blocker door is exemplified as the structural member 10, but the use of the structural member 10 according to the present embodiment is not particularly limited. The reinforcing member 14 according to the present embodiment can be applied to structural members of any shape and use.

[0013] The structural member 10 includes a main body member 12 and a reinforcing member 14. The main body member 12 is a plate-shaped member, and has a surface 12a against which the bypass airflow hits during reverse injection, and a back surface 12b on the side opposite to the surface 12a. The main body member 12 has a shape that gently curves as a whole. Since the main body member 12 is a thin plate-shaped member, it is likely to be deformed (for example, bent) by the load applied to the surface 12a. The reinforcing member 14 is attached to the back surface 12b of the main body member 12, suppresses the deformation (for example, bending) of the surface 12a of the main body member 12, and increases the rigidity of the main body member 12. The reinforcing member 14 is a plate-shaped member with irregularities formed thereon, and suppresses deformation (for example, bending) by the irregular shape.

[0014] Conventionally, a sandwich panel having a honeycomb core has been used as a lightweight and high-rigidity structural member. Since the honeycomb core itself is expensive and not easily processed into an arbitrary shape, the processing is costly. In the present embodiment, the main body member 12 and the reinforcing member 14 are made of a fiber-reinforced resin (FRP; Fiber Reinforced Plastics), and by joining the reinforcing member 14 to the main body member 12, a lightweight and high-rigidity structural member 10 is realized without using a honeycomb core.

[0015] Figs. 2 to 5 are diagrams schematically showing the configuration of the reinforcing member 14 according to the embodiment. The reinforcing member 14 is composed of a plate-shaped member 16 with irregularities formed thereon. The plate-shaped member 16 has a first surface 16a and a second surface 16b on the side opposite to the first surface 16a. Fig. 2 is a perspective view when looking at the first surface 16a, Fig. 3 is a perspective view when looking at the second surface 16b, Fig. 4 is a top view when looking at the first surface 16a, and Fig. 5 is a side sectional view corresponding to the cross section taken along the line V-V in Fig. 4.

[0016] In the drawings, the thickness direction of the reinforcing member 14 is defined as the z-direction, the longitudinal direction of the reinforcing member 14 is defined as the x-direction, and the direction orthogonal to the x-direction and the z-direction is defined as the y-direction. These directions are set for facilitating the understanding of the embodiments and do not limit the directions during the manufacturing or use of the structural member 10 and the reinforcing member 14 in any way. Also, in the drawings, solid lines are attached to the bending portions of the concavo-convex shape to clearly show the concavo-convex shape.

[0017] The shape of the outer edge 18 of the plate-like member 16 is, for example, a quadrilateral, for example, a rectangle. The outer edge 18 of the plate-like member 16 has a long side 18a extending in the longitudinal direction (for example, the x-direction), a short side 18b extending in the direction intersecting the longitudinal direction (for example, the y-direction), and a corner portion 18c provided between the long side 18a and the short side 18b. The shape of the outer edge 18 of the plate-like member 16 is not particularly limited and may be a trapezoid, a rhombus, a parallelogram, or any polygon such as a triangle, a pentagon, or a hexagon. The corner portion 18c of the plate-like member 16 may be chamfered. The corner portion 18c may be chamfered linearly or arcuately.

[0018] The plate-like member 16 is configured to have a uniform thickness t (see FIG. 5) as a whole. The thickness t of the plate-like member 16 is not particularly limited, but is, for example, 0.5 mm or more and 10 mm or less, preferably 1 mm or more and 5 mm or less.

[0019] The plate-like member 16 includes an outer peripheral portion 20, a convex portion 22, and a plurality of concave portions 24.

[0020] The outer peripheral portion 20 is a portion that defines the outer edge 18 of the plate-like member 16. The outer peripheral portion 20 has a frame shape or a closed-loop shape along the outer edge 18 of the plate-like member 16. The outer peripheral portion 20 is a portion with less shape change in the thickness direction compared to the convex portion 22 and the plurality of concave portions 24. The outer peripheral portion 20 is a portion joined to the back surface 12b of the main body member 12 and has a shape along the back surface 12b of the main body member 12. If the back surface 12b of the main body member 12 has a gently curved shape, the outer peripheral portion 20 has a gently curved shape as a whole. If the back surface 12b of the main body member 12 is flat, the outer peripheral portion 20 has a flat shape as a whole.

[0021] The convex portion 22 is formed inside the outer peripheral portion 20. The convex portion 22 is formed in a region inside the region where the outer peripheral portion 20 is formed in a plan view of the first surface 16a (see FIG. 4). The convex portion 22 is a portion that protrudes in the thickness direction with respect to the outer peripheral portion 20. The convex portion 22 protrudes toward the first surface 16a and is formed such that the first surface 16a is convex and the second surface 16b is concave. The convex portion 22 is formed, for example, so as to occupy most of the plate-like member 16. The area S1 surrounded by the outer edge 26 of the convex portion 22 is 50% or more of the area S surrounded by the outer edge 18 of the plate-like member 16, preferably 70% or more or 80% or more.

[0022] The outer edge 26 of the convex portion 22 has a first section 26a extending in the longitudinal direction (e.g., the x direction) along the long side 18a, a second section 26b extending in a direction intersecting the longitudinal direction (e.g., the y direction) along the short side 18b, and a third section 26c extending in an arc shape between the first section 26a and the second section 26b. The radius of curvature of the third section 26c is larger than the radius of curvature of the corner 18c of the plate-like member 16. In the illustrated example, the outer edge 26 of the convex portion 22 has a shape with the four corners of a quadrilateral made into an arc shape.

[0023] The top 28 of the convex portion 22 is configured such that the height h1 in the thickness direction from the outer peripheral portion 20 (see FIG. 5) is constant. When the outer peripheral portion 20 is flat, the top 28 is also configured to be flat. When the outer peripheral portion 20 gently curves, the top 28 is also configured to gently curve. The height h1 in the thickness direction from the outer peripheral portion 20 to the top 28 is preferably 50 mm or less, and more preferably 30 mm or less. The height h1 in the thickness direction from the outer peripheral portion 20 to the top 28 is preferably greater than the thickness t of the plate-like member 16, for example, 5 mm or more, and for example, 10 mm or more.

[0024] An outer inclined portion 30 (see FIG. 5) is provided between the outer peripheral portion 20 and the top 28. The outer inclined portion 30 is formed such that the height increases monotonically from the outer peripheral portion 20 toward the top 28. The outer inclined portion 30 is formed such that the inclination does not change abruptly from the outer peripheral portion 20 toward the top 28, and is preferably formed only by a smooth curved surface. The outer inclined portion 30 is configured by a smooth curve having a curvature radius of, for example, 20 mm or more or 30 mm or more in a cross-sectional view orthogonal to the outer edge 18 of the plate-like member 16.

[0025] The plurality of concave portions 24 are formed inside the convex portion 22. The plurality of concave portions 24 are formed in a region inside the outer edge 26 of the convex portion 22 in a plan view of the first surface 16a (see FIG. 4). The plurality of concave portions 24 are formed, for example, in a region inside the outer edge of the top 28 in a plan view of the first surface 16a (see FIG. 4). The plurality of concave portions 24 are formed to be recessed in the thickness direction with respect to the top 28. The plurality of concave portions 24 protrude toward the second surface 16b side, and are formed such that the first surface 16a is concave and the second surface 16b is convex. The plurality of concave portions 24 are arranged in a lattice pattern at the top 28. The plurality of concave portions 24 are arranged in the longitudinal direction (for example, the x direction) of the plate-like member 16 and are also arranged in a direction (for example, the y direction) intersecting the longitudinal direction. The plurality of concave portions 24 may be arranged radially at the top 28.

[0026] The outer edge 32 (see FIG. 4) of each of the plurality of recesses 24 has a first section 32a extending in the longitudinal direction (e.g., the x-direction) along the long side 18a, a second section 32b extending in a direction intersecting the longitudinal direction (e.g., the y-direction) along the short side 18b, and a third section 32c extending in an arc shape between the first section 32a and the second section 32b. The radius of curvature of the third section 32c is larger than the radius of curvature of the corner 18c of the plate-like member 16. In the illustrated example, the outer edge 32 of the recess 24 has a shape in which the four corners of a quadrilateral are rounded. The outer edges 32 of each of the plurality of recesses 24 have substantially the same size in the longitudinal direction (e.g., the x-direction) and the size in the direction intersecting the longitudinal direction (e.g., the y-direction). That is, the length of the first section 32a is substantially the same as the length of the second section 32b, for example, about 0.8 times to 1.2 times the length of the second section 32b.

[0027] The bottom 34 of each of the plurality of recesses 24 is a portion joined to the back surface 12b of the main body member 12. The bottom 34 is configured such that the depth h2 (see FIG. 5) in the thickness direction from the top 28 is constant. When the outer peripheral portion 20 is flat, the bottom 34 of each of the plurality of recesses 24 is configured to be located on a virtual plane B (see FIG. 5) defined by the outer peripheral portion 20. When the outer peripheral portion 20 is gently curved, the bottom 34 of each of the plurality of recesses 24 is configured to be located on the curved surface defined by the outer peripheral portion 20. The height h2 in the thickness direction from the top 28 to the bottom 34 is preferably 50 mm or less, and more preferably 30 mm or less. The height h2 in the thickness direction from the top 28 to the bottom 34 is, for example, 5 mm or more and, for example, 10 mm or more.

[0028] The bottom 34 of each of the plurality of recesses 24 has a quadrilateral shape or a shape in which the four corners of a quadrilateral are rounded. By making the bottom 34 have a shape approximated to a quadrilateral or a quadrilateral, the area occupied by the bottom 34 can be increased compared to the case where the bottom 34 is circular. Thereby, the joint area between the main body member 12 and the top 28 can be increased, and the joint strength between the main body member 12 and the reinforcing member 14 can be enhanced.

[0029] Between the top portion 28 and the bottom portion 34, an inner inclined portion 36 (see FIG. 5) is provided. The inner inclined portion 36 is formed such that the height monotonically increases from the bottom portion 34 toward the top portion 28. The inner inclined portion 36 is formed such that the inclination does not change abruptly from the bottom portion 34 toward the top portion 28, and is preferably formed only by a smooth curved surface. The inner inclined portion 36 is configured by a smooth curve having a radius of curvature of, for example, 20 mm or more or 30 mm or more in a cross-sectional view orthogonal to the outer edge 18 of the plate-like member 16.

[0030] The top portion 28 has a lattice frame shape surrounding the outer edges 32 of the plurality of recesses 24 when the plurality of recesses 24 are arranged in a lattice pattern. FIG. 6 is a top view schematically showing the lattice frame shape of the top portion 28, and the lattice frame shape of the top portion 28 is schematically shown by a thick line. The top portion 28 includes a plurality of first beams 38a, 38b extending in the longitudinal direction (for example, the x direction), a plurality of second beams 40a, 40b extending in a direction intersecting the longitudinal direction (for example, the y direction), and a plurality of corner portions 42 extending in an arc shape. The plurality of first beams 38a, 38b include an outer first beam 38a located outside the plurality of recesses 24 and an inner first beam 38b located between the plurality of recesses 24. The plurality of second beams 40a, 40b include an outer second beam 40a located outside the plurality of recesses 24 and an inner second beam 40b located between the plurality of recesses 24. The outer first beam 38a and the outer second beam 40a are connected by a corner portion 42 extending in an arc shape. Both ends of the inner first beam 38b are connected to the outer second beam 40a. Both ends of the inner second beam 40b are connected to the outer first beam 38a. By having the lattice frame shape formed by the first beams 38a, 38b, the second beams 40a, 40b, and the corner portions 42, the top portion 28 can cope with load changes in both the longitudinal direction (for example, the x direction) and the direction intersecting the longitudinal direction (for example, the y direction).

[0031] The reinforcing member 14 is made of a fiber-reinforced resin, for example, a thermoplastic fiber-reinforced resin. The reinforcing member 14 is formed by heating and pressing a prepreg sheet formed by impregnating reinforcing fibers with a resin in a mold for shaping. As the reinforcing fibers, carbon fibers, glass fibers, or aramid fibers can be used. The reinforcing fibers are preferably continuous fibers without joints or cuts, and it is preferable to use reinforcing fibers that continuously extend along the uneven shape of the plate-like member 16. As the thermoplastic resin impregnated into the reinforcing fibers, engineering plastics such as polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) can be used. Note that the main body member 12 can also be made of the same fiber-reinforced resin as the reinforcing member 14, and can be made of the same thermoplastic fiber-reinforced resin as the reinforcing member 14. The main body member 12 or the reinforcing member 14 may be made of a thermosetting fiber-reinforced resin. In this case, an epoxy resin or the like can be used as the thermosetting resin impregnated into the reinforcing fibers.

[0032] Figs. 7(a) and (b) are diagrams schematically showing a method for forming a prepreg sheet. Fig. 7(a) shows a prepreg tape 50 used for forming the prepreg sheet. The prepreg tape 50 is obtained by impregnating a plurality of reinforcing fibers 52 oriented in a single direction with a thermoplastic resin 54. The plurality of reinforcing fibers 52 are oriented so as to extend in the longitudinal direction A of the prepreg tape 50. The thermoplastic resin 54 fills the gaps between the plurality of reinforcing fibers 52 and fixes the fiber bundle composed of the plurality of reinforcing fibers 52 so that the relative positions of the plurality of reinforcing fibers 52 do not change. The width w of the prepreg tape 50 is not particularly limited, but is, for example, 1 mm or more and 20 mm or less, and for example, 2 mm or more and 10 mm or less. The length L of the prepreg tape 50 is larger than the outer dimension of the reinforcing member 14, and is, for example, 0.5 m or more or 1 m or more. The thickness of the prepreg tape 50 is, for example, 0.1 mm or more and 2 mm or less, and for example, 0.2 mm or more and 1 mm or less.

[0033] FIG. 7(b) shows a prepreg sheet 60 formed using the prepreg tape 50. The prepreg sheet 60 is formed by braiding a plurality of first prepreg tapes 56 extending in the first direction A1 and a plurality of second prepreg tapes 58 extending in a second direction A2 intersecting the first direction A1. Each of the first prepreg tape 56 and the second prepreg tape 58 is configured in the same manner as the prepreg tape 50 shown in FIG. 7(a). In the prepreg sheet 60 shown in FIG. 7(b), the first direction A1 and the second direction A2 are orthogonal. That is, when the first direction A1 is the 0-degree direction, the second direction A2 is the 90-degree direction.

[0034] There is a first gap d1 between the plurality of first prepreg tapes 56. The first gap d1 is smaller than the width w1 of the first prepreg tape 56. The first gap d1 is, for example, 1% or more and 50% or less of the width w1 of the first prepreg tape 56, preferably 5% or more and 25% or less. Similarly, there is a second gap d2 between the plurality of second prepreg tapes 58. The second gap d2 is smaller than the width w2 of the second prepreg tape 58. The second gap d2 is, for example, 1% or more and 50% or less of the width w2 of the second prepreg tape 58, preferably 5% or more and 25% or less. The width w1 of the first prepreg tape 56 may be the same as or different from the width w2 of the second prepreg tape 58. The first gap d1 may be the same as or different from the second gap d2.

[0035] The prepreg sheet 60 is not fixed between the first prepreg tape 56 and the second prepreg tape 58 that intersect each other. Therefore, the plurality of first prepreg tapes 56 are displaceable in the second direction A2 with respect to each other, and are configured such that the first gap d1 is variable. Similarly, the plurality of second prepreg tapes 58 are displaceable in the first direction A1 with respect to each other, and are configured such that the second gap d2 is variable.

[0036] The resin weight content (wt%) of the prepreg sheet 60 is 50% or less, for example, 40% or less, 35% or less, 30% or less, or 25% or less. By reducing the resin weight content of the prepreg sheet 60, the rigidity of the reinforcing member 14 can be increased. The resin weight content (wt%) of the prepreg tape 50 forming the prepreg sheet 60 may be equivalent to the resin weight content of the prepreg sheet 60, and is 50% or less, for example, 40% or less, 35% or less, 30% or less, or 25% or less.

[0037] In the prepreg sheet 60 shown in FIG. 7(b), the first prepreg tape 56 and the second prepreg tape 58 are woven so as to form a twill weave. The method of weaving the prepreg sheet is not limited to twill weave, and the prepreg sheet may be formed using any other weaving method such as plain weave or satin weave. Further, the prepreg sheet may be woven using prepreg tapes extending in three or more directions. For example, a plurality of first prepreg tapes extending in a first direction (for example, 0-degree direction), a plurality of second prepreg tapes extending in a second direction (for example, +60-degree direction) intersecting the first direction, and a plurality of third prepreg tapes extending in a third direction (for example, -60-degree direction) intersecting the first and second directions may be used for weaving.

[0038] The prepreg sheet may be woven without using a prepreg tape in which resin is impregnated into single-direction fibers. The prepreg sheet may be formed, for example, by impregnating a thermoplastic resin throughout a continuous fiber sheet woven using continuous fibers. For example, a plurality of first continuous fibers extending in a first direction (for example, 0-degree direction) and a plurality of second continuous fibers extending in a second direction (for example, 90-degree direction) intersecting the first direction may be woven by plain weave, twill weave, satin weave, etc. to form a continuous fiber sheet. The prepreg sheet may be formed by impregnating such a continuous fiber sheet with a thermoplastic resin. In this case, the space between the first continuous fiber and the second continuous fiber intersecting each other in the prepreg sheet is fixed with resin.

[0039] FIG. 8 is a diagram schematically showing a method for molding the reinforcing member 14 according to the embodiment. A mold 62 for molding the reinforcing member 14 is prepared, and a plurality of prepreg sheets 60a, 60b, 60c are laminated and arranged between the upper mold 64 and the lower mold 66 of the mold 62. The upper mold 64 has a concavo-convex shape corresponding to the first surface 16a of the plate-like member 16, and the lower mold 66 has a concavo-convex shape corresponding to the second surface 16b of the plate-like member 16. Note that the vertical relationship between the upper mold 64 and the lower mold 66 does not matter, and they may be used with the vertical direction reversed.

[0040] Each of the plurality of prepreg sheets 60a to 60c is configured in the same manner as the prepreg sheet 60 shown in FIG. 7(b). The plurality of prepreg sheets 60a to 60c include a first prepreg sheet 60a, a second prepreg sheet 60b, and an intermediate prepreg sheet 60c. The first prepreg sheet 60a is a sheet that contacts the upper mold 64 and constitutes the first surface 16a of the plate-like member 16. The second prepreg sheet 60b is a sheet that contacts the lower mold 66 and constitutes the second surface 16b of the plate-like member 16. The intermediate prepreg sheet 60c is disposed between the first prepreg sheet 60a and the second prepreg sheet 60b. In the example of FIG. 8, five prepreg sheets are laminated, and one first prepreg sheet 60a, one second prepreg sheet 60b, and three intermediate prepreg sheets 60c are laminated. Note that the number of laminated prepreg sheets is not particularly limited, and it may be four or less, or six or less. The number of laminated prepreg sheets can be appropriately set according to the thickness of the prepreg sheet and the thickness t of the reinforcing member 14 to be molded.

[0041] The plurality of prepreg sheets 60a to 60c may be arranged such that the orientation directions of the prepreg tapes constituting the prepreg sheets 60a to 60c are different from each other. FIGS. 9(a) and (b) are diagrams schematically showing the orientation directions of the prepreg sheets 60a to 60c. FIG. 9(a) shows the orientation directions of the first prepreg sheet 60a and the second prepreg sheet 60b. In the first prepreg sheet 60a and the second prepreg sheet 60b, the orientation directions A1 and A2 of the first prepreg tape 56 and the second prepreg tape 58 are at an angle of 45 degrees with respect to the longitudinal direction (for example, the x direction) of the reinforcing member 14. FIG. 9(b) shows the orientation direction of the intermediate prepreg sheet 60c. In the intermediate prepreg sheet 60c, the orientation direction A1 of the first prepreg tape 56 coincides with the longitudinal direction (for example, the x direction) of the reinforcing member 14. Therefore, the orientation directions A1 and A2 of the intermediate prepreg sheet 60c are rotated by 45 degrees with respect to the orientation directions A1 and A2 of the first prepreg sheet 60a and the second prepreg sheet 60b.

[0042] By heating and pressurizing the plurality of prepreg sheets 60a to 60c between the upper mold 64 and the lower mold 66 shown in FIG. 8, the plate-like member 16 can be formed. The plurality of prepreg sheets 60a to 60c in FIG. 8 are heated to a temperature equal to or higher than the melting point of the thermoplastic resin 54 by the upper mold 64 and the lower mold 66 provided with heaters. The plurality of prepreg sheets 60a to 60c are integrated by heating and pressurizing with the mold 62 and are formed into the plate-like member 16. Then, by taking out the plate-like member 16 from the mold 62, the plate-like member 16 is completed. After the forming by the mold 62, the unnecessary portions as the reinforcing member 14 may be cut from the plate-like member 16, or the first surface 16a or the second surface 16b of the plate-like member 16 may be polished.

[0043] FIG. 10 is a top view showing the reinforcing member 14 according to the embodiment. The reinforcing member 14 shown in FIG. 10 shows a case where carbon fiber is used as the reinforcing fiber, PEEK is used as the thermoplastic resin, and the prepreg sheets 60a, 60b, and 60c shown in FIGS. 9(a) and 9(b) are used. As shown in FIG. 10, it can be seen that a plate-like member 16 having a complex concavo-convex shape including convex portions 22 and a plurality of concave portions 24 is formed. In particular, since there is almost no shift in the weave of the prepreg tape extending in the ±45-degree direction over the entire plate-like member 16, the reinforcing member 14 can have high rigidity over the entire plate-like member 16. Also, it can be seen that the bottom 34 of each of the plurality of concave portions 24 has a shape close to a quadrangle.

[0044] FIG. 11 is a diagram schematically showing the joint portion 44 between the main body member 12 and the reinforcing member 14. The reinforcing member 14 is joined to the back surface 12b of the main body member 12. The reinforcing member 14 is joined to the main body member 12 by a plurality of joint portions 44. The plurality of joint portions 44 are provided between the back surface 12b of the main body member 12 and the second surface 16b of the reinforcing member 14. The plurality of joint portions 44 are provided on the outer peripheral portion 20 and the bottom 34 of the reinforcing member 14. A cavity 48 is provided between the main body member 12 and the reinforcing member 14.

[0045] The main body member 12 and the reinforcing member 14 can be joined by fusing the thermoplastic resins constituting the main body member 12 and the reinforcing member 14. In this case, the plurality of joint portions 44 are constituted by the thermoplastic resins constituting the main body member 12 and the reinforcing member 14, and are constituted by, for example, PEEK or PEKK. For example, after heating the joint portion of the main body member 12 and the reinforcing member 14 by irradiation with laser light or by ultrasonic vibration, the heated portion is brought into contact and pressurized and cooled to form the joint portion 44. The plurality of joint portions 44 may be an adhesive. For example, after applying an adhesive to the main body member 12 or the reinforcing member 14 or attaching an adhesive tape, the joint portion 44 may be formed by bringing the portion provided with the adhesive into contact and pressurizing. The adhesive may be the same resin material as the thermoplastic resin constituting the main body member 12 and the reinforcing member 14, or may be a different material.

[0046] The body member 12 and the reinforcing member 14 may be joined using fastening members such as bolts and rivets. For example, through holes may be provided in the body member 12 and the reinforcing member 14 at positions corresponding to the plurality of joining portions 44, and fastening members such as bolts and rivets may be inserted through the through holes, and the body member 12 and the reinforcing member 14 may be mechanically joined using the fastening members. Joining by the fastening members may be used instead of the joining portion 44 formed of a fusion part or an adhesive, or may be used in combination with the joining portion 44 formed of a fusion part or an adhesive.

[0047] According to the present embodiment, since the reinforcing member 14 can be composed of only the single plate-like member 16, the structure of the reinforcing member 14 can be simplified compared with the case of using a honeycomb core. Further, since the reinforcing member 14 can be formed by the shaping by molding using the mold 62, the manufacturing process of the reinforcing member 14 can be simplified compared with the case of using a honeycomb core. Since the reinforcing member 14 includes the top portion 28 having a lattice frame shape including beams extending in the longitudinal direction (for example, the x direction) of the reinforcing member 14 and the direction (for example, the y direction) intersecting the longitudinal direction, it is possible to cope with loads in both the longitudinal direction and the direction intersecting the longitudinal direction. As a result, the reinforcing member 14 can suitably suppress the deformation of the body member 12.

[0048] According to the present embodiment, since the reinforcing member 14 can be constituted by continuous reinforcing fibers over the entire reinforcing member 14, the rigidity of the reinforcing member 14 can be improved compared with the case where a cut portion is provided in the middle of the reinforcing fibers. According to the present embodiment, since the outer inclined portion 30 and the inner inclined portion 36 are configured to gently curve, it is possible to suppress the deviation of the stitches of the prepreg tape formed of continuous fibers, and the overall rigidity of the reinforcing member 14 can be improved.

[0049] FIG. 12 is a perspective view schematically showing the configuration of the reinforcing member 70 according to the modified example, and shows a view when the reinforcing member 70 is viewed from the first surface 16a. The reinforcing member 70 is different from the above-described embodiment in that it further includes a first rib 72 provided on the first surface 16a of the plate-like member 16. The plate-like member 16 is configured in the same manner as in the above-described embodiment.

[0050] The reinforcing member 70 includes a plate-like member 16 and a first rib 72. The first rib 72 is provided on the first surface 16a of the plate-like member 16 and extends in the thickness direction from the first surface 16a. The first rib 72 is provided inside at least one of the plurality of recesses 24. In the example of FIG. 12, the first rib 72 is provided inside the central recess 24 in the longitudinal direction (for example, the x direction). Note that the first rib 72 can be provided inside any two or more of the plurality of recesses 24, or can be provided inside all of the plurality of recesses 24. The upper surface of the first rib 72 is configured to be flush with the top 28, for example.

[0051] The first rib 72 includes a first horizontal rib 74 extending in the longitudinal direction (for example, the x direction) and a first vertical rib 76 extending in a direction intersecting the longitudinal direction (for example, the y direction). Both ends of the first horizontal rib 74 are connected to the outer edge 32 of the recess 24. Both ends of the first vertical rib 76 are connected to the outer edge 32 of the recess 24. The first horizontal rib 74 and the first vertical rib 76 intersect and are connected at the position of the bottom 34 of the recess 24. The first rib 72 may further include a first diagonal rib (not shown) extending in a diagonal direction (for example, the ±45-degree direction) with respect to the first horizontal rib 74 or the first vertical rib 76. The first rib 72 can include any one or more selected from the group including the first horizontal rib 74, the first vertical rib 76, and the first diagonal rib.

[0052] FIG. 13 is a perspective view schematically showing the configuration of the reinforcing member 70 according to the modified example, and shows a view when the reinforcing member 70 is viewed from the second surface 16b. The reinforcing member 70 further includes a second rib 82 provided on the second surface 16b of the plate-like member 16. The lower surface of the second rib 82 is configured to be flush with each of the outer peripheral portion 20 and the bottom 34 of the plurality of recesses 24. The lower surface of the second rib 82 is configured to be located on the virtual plane B shown in FIG. 5, for example.

[0053] The second rib 82 is provided on the second surface 16b of the plate-like member 16 and extends in the thickness direction from the second surface 16b. The second rib 82 is provided inside the convex portion 22. The second rib 82 includes second horizontal ribs 84a and 84b extending in the longitudinal direction (for example, the x direction), second vertical ribs 86a and 86b extending in a direction intersecting the longitudinal direction (for example, the y direction), and second diagonal ribs 88a and 88b extending in an oblique direction (for example, the ±45-degree direction).

[0054] The second horizontal ribs 84a and 84b include a second outer horizontal rib 84a connecting between the outer peripheral portion 20 and the bottom portion 34, and a second inner horizontal rib 84b connecting between the two bottom portions 34. The second vertical ribs 86a and 86b include a second outer vertical rib 86a connecting between the outer peripheral portion 20 and the bottom portion 34, and a second inner vertical rib 86b connecting between the two bottom portions 34. The second diagonal ribs 88a and 88b include a second outer diagonal rib 88a connecting between the outer peripheral portion 20 and the bottom portion 34, and a second inner diagonal rib 88b connecting between the two bottom portions 34. The second rib 82 can include any one or more selected from the group consisting of the second outer horizontal rib 84a, the second inner horizontal rib 84b, the second vertical rib 86a, the second inner vertical rib 86b, the second outer diagonal rib 88a, and the second inner diagonal rib 88b.

[0055] The first rib 72 and the second rib 82 are made of a fiber-reinforced resin. The first rib 72 and the second rib 82 may be made of the same thermoplastic fiber-reinforced resin or thermosetting fiber-reinforced resin as the plate-like member 16, or may be made of a thermoplastic fiber-reinforced resin or thermosetting fiber-reinforced resin of a material different from that of the plate-like member 16. As the reinforcing fibers constituting the first rib 72 and the second rib 82, carbon fibers, glass fibers, or aramid fibers can be used. As the resin constituting the first rib 72 and the second rib 82, engineering plastics such as thermoplastic resins such as PEEK and PEKK, and thermosetting resins such as epoxy resins can be used. The first rib 72 and the second rib 82 may be constituted by, for example, reinforcing fibers that are not continuous with the reinforcing fibers constituting the plate-like member 16.

[0056] FIG. 14 is a diagram schematically showing a method of forming the reinforcing member 70 according to the modified example. The mold 92 for forming the reinforcing member 70 in the modified example is different from the mold 62 according to the above-described embodiment in that it includes groove portions 98 and 100 for forming the first rib 72 and the second rib 82. The upper mold 94 has an uneven shape corresponding to the first surface 16a of the plate-like member 16 and has a first groove portion 98 for forming the first rib 72. The lower mold 96 has an uneven shape corresponding to the second surface 16b of the plate-like member 16 and has a second groove portion 100 for forming the second rib 82.

[0057] The first groove portion 98 is filled with the prepreg 90a, and the second groove portion 100 is filled with the prepreg 90b. The prepregs 90a and 90b filled in the groove portions 98 and 100 are, for example, chopped materials obtained by cutting the prepreg tape 50 or the prepreg sheet 60. The size (width and length) of the prepregs 90a and 90b is not particularly limited. The width of the prepregs 90a and 90b is 1 mm or more and 20 mm or less, for example, 2 mm or more and 10 mm or less. The length of the prepregs 90a and 90b is 5 mm or more and 50 mm or less, for example, 10 mm or more and 30 mm or less.

[0058] Between the upper mold 94 filled with the prepreg 90a in the first groove portion 98 and the lower mold 96 filled with the prepreg 90b in the second groove portion 100, a plurality of prepreg sheets 60a, 60b, and 60c are laminated and arranged. The plurality of prepreg sheets 60a, 60b, and 60c are the same as those in the above-described embodiment.

[0059] By heating and pressing a plurality of prepreg sheets 60a to 60c and prepregs 90a and 90b between the upper mold 94 and the lower mold 96 shown in FIG. 14, a reinforcing member 70 in which a first rib 72 and a second rib 82 are formed on the plate-like member 16 can be molded. The plurality of prepreg sheets 60a to 60c and prepregs 90a and 90b are heated to a temperature equal to or higher than the melting point of the thermoplastic resin 54 by the upper mold 94 and the lower mold 96 provided with heaters. The plurality of prepreg sheets 60a to 60c and prepregs 90a and 90b are integrated by heating and pressing with the mold 92 and are formed into the reinforcing member 70. Thereafter, by taking out from the mold 92, the reinforcing member 70 is completed.

[0060] According to this modified example, since the first rib 72 is formed on the first surface 16a of the plate-like member 16 and the second rib 82 is formed on the second surface 16b of the plate-like member 16, the rigidity of the reinforcing member 70 can be further improved.

[0061] The reinforcing member 70 according to this modified example can be joined and used with the main body member 12. For example, in addition to the outer peripheral portion 20 and the bottom portion 34 of the reinforcing member 70, the lower surface of the second rib 82 can be joined to the back surface 12b of the main body member 12. The reinforcing member 70 can be joined to the main body member 12 by the same method as in the above-described embodiment. The structural member 10 can include the main body member 12 and the reinforcing member 70 according to this modified example.

[0062] In a further modified example, the reinforcing member 70 may include only one of the first rib 72 and the second rib 82. The reinforcing member 70 may include only the first rib 72 and not include the second rib 82. The reinforcing member 70 may include only the second rib 82 and not include the first rib 72.

[0063] FIG. 15 is a side sectional view schematically showing the configuration of a structural member 110 according to another embodiment. The structural member 110 according to this embodiment has a so-called sandwich panel structure. The structural member 110 includes a first main body member 112, a second main body member 114, a first reinforcing member 116, and a second reinforcing member 118.

[0064] The first main body member 112 and the second main body member 114 are members corresponding to the skins of the sandwich panel. Each of the first main body member 112 and the second main body member 114 can be configured in the same manner as the main body member 12 according to the above-described embodiment. The first reinforcing member 116 and the second reinforcing member 118 are members corresponding to the core of the sandwich panel. Each of the first reinforcing member 116 and the second reinforcing member 118 can be configured in the same manner as the reinforcing member 14 according to the above-described embodiment or the reinforcing member 70 according to the modified example.

[0065] The first reinforcing member 116 includes a first outer peripheral portion 120, a first top portion 122, and a plurality of first bottom portions 124. The first reinforcing member 116 is joined to the first main body member 112 via a plurality of first joining portions 126. The first main body member 112 is joined to the first outer peripheral portion 120 and the plurality of first bottom portions 124 via the plurality of first joining portions 126. A first cavity 128 is provided between the first main body member 112 and the first reinforcing member 116.

[0066] The second reinforcing member 118 includes a second outer peripheral portion 130, a second top portion 132, and a plurality of second bottom portions 134. The second reinforcing member 118 is joined to the second main body member 114 via a plurality of second joining portions 136. The second main body member 114 is joined to the second outer peripheral portion 130 and the plurality of second bottom portions 134 via the plurality of second joining portions 136. A second cavity 138 is provided between the second main body member 114 and the second reinforcing member 118.

[0067] The first reinforcing member 116 is joined to the second reinforcing member 118 via a third joining portion 140. The third joining portion 140 is provided between the first top portion 122 and the second top portion 132. A third cavity 142 is provided between the first reinforcing member 116 and the second reinforcing member 118.

[0068] Each of the first joint portion 126, the second joint portion 136, and the third joint portion 140 can be configured in the same manner as the joint portion 44 according to the above-described embodiment. Each of the first joint portion 126, the second joint portion 136, and the third joint portion 140 may be formed by fusing a thermoplastic resin by laser heating or ultrasonic heating, or may be formed by any adhesive. Each of the first joint portion 126, the second joint portion 136, and the third joint portion 140 may be joined by fastening members such as bolts and rivets.

[0069] According to the present embodiment, a sandwich panel structure can be realized by combining four plate-like members. According to the present embodiment, compared with the case of using a honeycomb core, the structure of the structural member 110 can be simplified, and the manufacturing process of the structural member 110 can be simplified.

[0070] As described above, the present invention has been described based on the examples. It is understood by those skilled in the art that the present invention is not limited to the above-described embodiment, various design changes are possible, various modifications are possible, and such modifications are also within the scope of the present invention.

[0071] Hereinafter, some aspects of the present invention will be described.

[0072] The first aspect of the present invention includes a plate-like member made of a fiber-reinforced resin using continuous fibers as reinforcing fibers and having a first surface and a second surface. The plate-like member includes an outer peripheral portion that defines an outer edge of the plate-like member, a convex portion where the first surface side is convex inside the outer peripheral portion, and a plurality of concave portions where the first surface side is concave inside the convex portion. According to the first aspect, by providing a convex portion inside the outer peripheral portion and a concavo-convex structure in which a plurality of concave portions are provided inside the convex portion, deformation such as bending can be suitably suppressed against loads in both the longitudinal direction of the reinforcing member and the direction intersecting the longitudinal direction. Further, by adopting a structure in which the plate-like member has concavo-convexities, the plate-like member can be constituted by a fiber-reinforced resin using continuous fibers as reinforcing fibers, and a lightweight and high-rigidity reinforcing member can be realized.

[0073] The second aspect of the present invention is the reinforcing member according to the first aspect, wherein the plurality of recesses are arranged in a lattice pattern or radially. According to the second aspect, by arranging the plurality of recesses in a lattice pattern or radially, deformation against a load in the direction in which the plurality of recesses are arranged can be suitably suppressed.

[0074] The third aspect of the present invention is the reinforcing member according to the first or second aspect, wherein the outer edge of the convex portion has a shape in which the four corners of a quadrilateral are rounded, and the outer edge of each of the plurality of recesses has a shape in which the four corners of a quadrilateral are rounded. According to the third aspect, by approximating the outer edge of each of the convex portion and the plurality of recesses to a quadrilateral, deformation against a load in the direction along the side of the quadrilateral can be suitably suppressed. Further, by forming the four corners of the outer edge of each of the convex portion and the plurality of recesses into an arc shape, it becomes easy to uniformly arrange continuous fibers along the surfaces of the convex portion and the plurality of recesses, and the rigidity of the entire reinforcing member can be improved.

[0075] The fourth aspect of the present invention is the reinforcing member according to the third aspect, wherein the bottom of each of the plurality of recesses has a shape of a quadrilateral or a quadrilateral with rounded corners. According to the fourth aspect, by approximating the bottom of each of the plurality of recesses to a quadrilateral, deformation against a load in the direction along the side of the quadrilateral can be suitably suppressed.

[0076] The fifth aspect of the present invention is the reinforcing member according to any one of the first to fourth aspects, wherein the curvature radii of the first surface and the second surface in a cross-sectional view perpendicular to the outer edge of the plate-like member are configured to be 20 mm or more. According to the fifth aspect, by setting the curvature radii of the first surface and the second surface to 20 mm or more, it becomes easy to uniformly arrange continuous fibers along the first surface and the second surface, and the rigidity of the entire reinforcing member can be improved.

[0077] The sixth aspect of the present invention is the reinforcing member according to any one of the first to fifth aspects, wherein the fiber-reinforced resin includes a continuous fiber sheet formed by braiding a plurality of continuous fibers extending in a first direction and a plurality of continuous fibers extending in a second direction intersecting the first direction. According to the sixth aspect, by using a continuous fiber sheet formed by braiding a plurality of continuous fibers extending in the first direction and the second direction intersecting each other, deformation such as bending can be suitably suppressed against loads in both the longitudinal direction of the reinforcing member and the direction intersecting the longitudinal direction.

[0078] The seventh aspect of the present invention is the reinforcing member according to any one of the first to sixth aspects, which is composed of a fiber-reinforced resin and further includes ribs extending from the first surface or the second surface. According to the seventh aspect, by providing ribs on the first surface or the second surface of the plate-like member, the rigidity of the reinforcing member can be further improved.

[0079] The eighth aspect of the present invention is the reinforcing member according to the seventh aspect, wherein the rib includes a first rib extending from the first surface inside at least one of the plurality of recesses. According to the eighth aspect, by providing the first rib inside the recess, deformation of the recess can be more suitably suppressed, and the rigidity of the reinforcing member can be further improved.

[0080] The ninth aspect of the present invention is the reinforcing member according to the seventh or eighth aspect, wherein the rib further includes a second rib extending from the second surface inside the convex portion. According to the ninth aspect, by providing the second rib inside the convex portion, deformation of the convex portion can be more suitably suppressed, and the rigidity of the reinforcing member can be further improved.

[0081] The tenth aspect of the present invention is the reinforcing member according to the ninth aspect, wherein the second rib connects between at least one bottom portion of the plurality of recesses and the outer peripheral portion. According to the tenth aspect, by providing the second rib connecting between the bottom portion and the outer peripheral portion, deformation of the bottom portion with respect to the outer peripheral portion can be more suitably suppressed, and the rigidity of the reinforcing member can be further improved.

[0082] The 11th aspect of the present invention is the reinforcing member according to the 9th or 10th aspect, wherein the second rib connects between the bottoms of two of the plurality of recesses. According to the 11th aspect, by providing the second rib that connects between the two bottoms, deformation of the bottom can be more suitably suppressed, and the rigidity of the reinforcing member can be further improved.

[0083] The 12th aspect of the present invention is the reinforcing member according to any one of the 1st to 11th aspects, wherein the resin weight content of the fiber-reinforced resin is 50% or less. According to the 12th aspect, by setting the resin weight content of the fiber-reinforced resin to 50% or less, the rigidity of the reinforcing member can be further improved.

[0084] The 13th aspect of the present invention is a structural member including the reinforcing member according to any one of the 1st to 12th aspects and a main body member joined to the outer peripheral portion of the reinforcing member and the bottom of each of the plurality of recesses, and a cavity is provided between the reinforcing member and the main body member. According to the 13th aspect, by joining the reinforcing member to the main body member, deformation of the main body member can be suppressed by the reinforcing member, and a structural member excellent in rigidity can be provided. Further, since a cavity is provided between the reinforcing member and the main body member, a lightweight and high-rigidity structural member can be provided.

[0085] A fourteenth aspect of the present invention is a mold for forming a plate-like member including an outer peripheral portion defining an outer edge of a plate-like member having a first surface and a second surface, a convex portion where the first surface side is convex inside the outer peripheral portion, and a plurality of concave portions where the first surface side is concave inside the convex portion. A step of disposing a prepreg sheet in which continuous fibers are impregnated with resin, and a step of heating and pressing the prepreg sheet using the mold to form a reinforcing member including the plate-like member composed of a fiber-reinforced resin. According to the fourteenth aspect, since the reinforcing member can be manufactured by shaping the prepreg sheet using a mold, the manufacturing process of the reinforcing member can be simplified. Further, by using a prepreg sheet in which continuous fibers are impregnated with resin, the work of arranging the prepregs can be simplified compared to the case of using small-cut prepregs, and the rigidity of the formed reinforcing member can be improved.

[0086] A fifteenth aspect of the present invention is the manufacturing method according to the fourteenth aspect, wherein the prepreg sheet is formed by knitting a plurality of first prepreg tapes extending in a first direction and a plurality of second prepreg tapes extending in a second direction intersecting the first direction, and each of the plurality of first prepreg tapes and the plurality of second prepreg tapes is formed by impregnating the resin into a plurality of continuous fibers extending in a single direction. According to the fifteenth aspect, since the gap between the prepreg tapes becomes variable according to the uneven shape of the mold during the shaping process, it becomes easy to arrange the prepreg tapes more uniformly along the uneven shape of the mold. As a result, a reinforcing member in which the prepreg tapes are uniformly arranged can be formed, and the rigidity of the reinforcing member can be improved.

[0087] The 16th aspect of the present invention is the manufacturing method according to the 14th aspect, wherein the prepreg sheet is formed by impregnating a continuous fiber sheet woven with a plurality of first continuous fibers extending in a first direction and a plurality of second continuous fibers extending in a second direction intersecting the first direction with the resin. According to the 16th aspect, by using a continuous fiber sheet woven with a plurality of continuous fibers extending in the first direction and the second direction intersecting each other, the rigidity of the formed reinforcing member can be improved.

[0088] The 17th aspect of the present invention is the manufacturing method according to any one of the 14th to 16th aspects, further comprising a step of filling a groove portion provided in the mold for forming a rib extending from the first surface or the second surface with a prepreg, and heating and pressing the prepreg sheet and the prepreg using the mold to form the reinforcing member in which the rib made of a fiber-reinforced resin is joined to the first surface or the second surface of the plate-like member. According to the 17th aspect, since a rib can be formed on the reinforcing member, the rigidity of the formed reinforcing member can be further improved. By filling the groove portion of the mold with a prepreg, a reinforcing member in which the plate-like member and the rib are integrated can be easily manufactured.

[0089] The 18th aspect of the present invention is the manufacturing method according to any one of the 14th to 17th aspects, further comprising a step of joining the outer peripheral portion of the reinforcing member and the bottom of each of the plurality of concave portions to the surface of the main body member to form a structural member. According to the 18th aspect, by joining the reinforcing member to the surface of the main body member, a lightweight and high-rigidity structural member can be easily manufactured.

Description of Reference Numerals

[0090] 10... Structural member, 12... Body member, 14... Reinforcing member, 16... Plate-like member, 16a... First surface, 16b... Second surface, 18... Outer edge, 20... Outer peripheral part, 22... Protrusion, 24... Recess, 26... Outer edge, 28... Top part, 30... Outer inclined part, 32... Outer edge, 34... Bottom part, 36... Inner inclined part, 50... Prepreg tape, 52... Reinforcing fiber, 54... Thermoplastic resin, 56... First prepreg tape, 58... Second prepreg tape, 60... Prepreg sheet, 62... Mold.

Claims

1. A reinforcing member comprising a plate-like member made of a fiber-reinforced resin using continuous fibers as reinforcing fibers and having a first surface and a second surface, wherein the plate-like member includes: an outer peripheral portion defining the outer edge of the plate-like member; a convex portion where the first surface side is convex inside the outer peripheral portion; a plurality of concave portions where the first surface side is concave inside the convex portion; and each of the plurality of concave portions is configured such that, in a cross-sectional view perpendicular to the outer edge of the plate-like member, there is no portion where the radii of curvature of the first surface and the second surface are less than 20 mm.

2. The reinforcing member according to claim 1, wherein the plurality of concave portions are arranged in a lattice pattern or a radial pattern.

3. The outer edge of the convex portion has a shape in which the four corners of a quadrilateral are arc-shaped. The reinforcing member according to claim 1, wherein the outer edge of each of the plurality of concave portions has a shape in which the four corners of a quadrilateral are arc-shaped.

4. The reinforcing member according to claim 3, wherein the bottom of each of the plurality of concave portions has a shape of a quadrilateral or a quadrilateral with rounded corners.

5. The height from the outer peripheral portion to the top of the convex portion is 5 mm or more and 50 mm or less. The reinforcing member according to claim 1, wherein the height from the top of the convex portion to the bottom of each of the plurality of concave portions is 5 mm or more and 50 mm or less.

6. The reinforcing member according to claim 1, wherein the fiber-reinforced resin includes a continuous fiber sheet formed by braiding a plurality of continuous fibers extending in a first direction and a plurality of continuous fibers extending in a second direction intersecting the first direction.

7. A reinforcing member comprising a plate-like member made of a fiber-reinforced resin using continuous fibers as reinforcing fibers and having a first surface and a second surface, wherein the plate-like member includes: an outer peripheral portion defining the outer edge of the plate-like member; a convex portion where the first surface side is convex inside the outer peripheral portion; a plurality of concave portions where the first surface side is concave inside the convex portion; and a reinforcing member made of a fiber-reinforced resin and further including ribs extending from the first surface or the second surface.

8. The reinforcing member according to claim 7, wherein the rib includes a first rib extending from the first surface inside at least one of the plurality of concave portions.

9. The reinforcing member according to claim 7, wherein the rib further includes a second rib extending from the second surface inside the convex portion.

10. The reinforcing member according to claim 9, wherein the second rib connects between the bottom of at least one of the plurality of concave portions and the outer peripheral portion.

11. The second rib is the reinforcing member according to claim 9 that connects between the bottoms of two of the plurality of recesses.

12. It is composed of a fiber-reinforced resin using continuous fibers as reinforcing fibers, and includes a plate-like member having a first surface and a second surface. The plate-like member an outer peripheral portion that defines the outer edge of the plate-like member, a convex portion where the first surface side is convex inside the outer peripheral portion, and a plurality of recesses where the first surface side is concave inside the convex portion. The plate-like member is formed by heating and pressing a prepreg sheet formed by knitting a plurality of first prepreg tapes extending in a first direction and a plurality of second prepreg tapes extending in a second direction intersecting the first direction. Each of the plurality of first prepreg tapes and the plurality of second prepreg tapes is a reinforcing member formed by impregnating a plurality of continuous fibers extending in a single direction with resin.

13. The reinforcing member according to any one of claims 1 to 12, and a main body member joined to each of the outer peripheral portion of the reinforcing member and the bottoms of the plurality of recesses. A structural member in which a cavity is provided between the reinforcing member and the main body member.

14. A step of disposing a prepreg sheet impregnated with resin on continuous fibers on a mold for forming a plate-like member including an outer peripheral portion that defines the outer edge of the plate-like member having a first surface and a second surface, a convex portion where the first surface side is convex inside the outer peripheral portion, and a plurality of recesses where the first surface side is concave inside the convex portion; a step of heating and pressing the prepreg sheet using the mold to form a reinforcing member including the plate-like member composed of a fiber-reinforced resin. Each of the plurality of recesses is configured such that in a cross-sectional view orthogonal to the outer edge of the plate-like member, there is no portion where the curvature radii of the first surface and the second surface are less than 20 mm.

15. The height from the outer peripheral portion to the top of the convex portion is 5 mm or more and 50 mm or less, The manufacturing method according to claim 14, wherein the height from the top of the convex portion to the bottom of each of the plurality of recesses is 5 mm or more and 50 mm or less.

16. A step of disposing a prepreg sheet in which continuous fibers are impregnated with resin on a mold for forming a plate-shaped member including an outer peripheral portion defining an outer edge of the plate-shaped member having a first surface and a second surface, a convex portion having the first surface side convex inside the outer peripheral portion, and a plurality of concave portions having the first surface side concave inside the convex portion; A step of heating and pressing the prepreg sheet using the mold to form a reinforcing member including the plate-shaped member made of a fiber-reinforced resin; The prepreg sheet is formed by braiding a plurality of first prepreg tapes extending in a first direction and a plurality of second prepreg tapes extending in a second direction intersecting the first direction; A manufacturing method in which each of the plurality of first prepreg tapes and the plurality of second prepreg tapes is formed by impregnating a plurality of continuous fibers extending in a single direction with the resin.

17. A step of disposing a prepreg sheet in which continuous fibers are impregnated with resin on a mold for forming a plate-shaped member including an outer peripheral portion defining an outer edge of the plate-shaped member having a first surface and a second surface, a convex portion having the first surface side convex inside the outer peripheral portion, and a plurality of concave portions having the first surface side concave inside the convex portion; A step of heating and pressing the prepreg sheet using the mold to form a reinforcing member including the plate-shaped member made of a fiber-reinforced resin; The mold includes a groove portion for forming a rib extending from the first surface or the second surface; Further comprising a step of filling the groove portion of the mold with prepreg; A manufacturing method of forming the reinforcing member in which the rib made of a fiber-reinforced resin is joined to the first surface or the second surface of the plate-shaped member by heating and pressing the prepreg sheet and the prepreg using the mold.

18. The manufacturing method according to any one of claims 14 to 17, further comprising a step of joining each of the outer peripheral portion of the reinforcing member and the bottom portions of the plurality of concave portions to the surface of the body member to form a structural member.

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