Panel components

Abstract

The purpose of the invention is to provide a highly versatile panel member that can be reduced in weight and improved in mechanical strength, and can be used for various applications.　A panel member (100) comprises: a first skin member (1) and a second skin member (2) that are sheet-like and include a thermoplastic resin; and an intermediate member (3) that includes continuous fibers and is disposed between the first skin member (1) and the second skin member (2). The intermediate member (3) has intermediate forming members (M1, M2, M3). The intermediate forming members (M1, M2, M3) respectively include: first portions (M11, M23, M33) joined to the first skin member (1); second portions (M13, M21, M31, M35) joined to the second skin member (2); and third portions (M12, M22, M24, M32, M34) connecting the first portions (M11, M23, M33) and the second portions (M13, M21, M31, M35).

Description

TECHNICAL FIELD

[0001] The present invention relates to a panel member having a skin member containing a thermoplastic resin and an intermediate member containing continuous fibers. BACKGROUND ART

[0002] Panel members are conventionally known in which a low-density intermediate member such as a honeycomb, polymer foam, or corrugated material is sandwiched between sheet-shaped skin members. Such panel members have excellent properties in terms of strength and rigidity. Therefore, such panel members are used in various fields and applications, such as components for aircraft fuselages.

[0003] A panel member having a corrugated intermediate member has superior bending strength compared to a panel member having a honeycomb intermediate member. When such a panel member contains a thermoplastic resin that can be secondarily molded by applying heat, it is advantageous for adopting a shape according to the application. In recent years, among such panel members, those that improve mechanical strength by devising the arrangement of continuous fibers are known (see, for example, Patent Document 1). PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] PATENT DOCUMENT 1 Japanese Unexamined Patent Application Publication No. 2019-130695 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] For the panel member having the skin member containing a thermoplastic resin and the intermediate member containing continuous fibers as described above, it is expected to expand the applicable range (that is, improve versatility) by reducing weight and improving mechanical strength at the same time. As a result of intensive studies, the present inventors have focused on a configuration that can achieve both of these two points at the same time.

[0006] Panel components can be used in a variety of applications, as they offer the potential for both weight reduction and improved mechanical strength. However, achieving both weight reduction and improved mechanical strength simultaneously is not always easy. For example, reducing the area occupied by intermediate components in a panel component can reduce its weight. However, this can easily lead to a decrease in the panel component's strength. For instance, depending on the application of the panel component, the load may not be uniform, and the required strength may differ from part to part. Also, if the panel component is not placed on a flat surface, or if the panel component itself does not have a flat shape, the load may not be evenly distributed across the various parts of the panel component. Considering the various environments in which panel components are used, localized mechanical strength deficiencies can occur. On the other hand, increasing the thickness uniformly to compensate for this deficiency can hinder weight reduction. Therefore, simply having a uniform shape and homogeneous structure in panel components does not mean there is still room for improvement in various aspects of practical application.

[0007] This invention has been made in view of these points, and aims to provide a highly versatile panel member that can be used in a variety of applications, while also enabling weight reduction and improved mechanical strength. [Means for solving the problem]

[0008] The panel member disclosed herein comprises a sheet-like first skin member and a second skin member containing a thermoplastic resin, and an intermediate member containing continuous fibers and disposed between the first skin member and the second skin member. The first skin member has a plurality of first joining portions joined to the intermediate member and a plurality of first non-joining portions not joined to the intermediate member. The second skin member has a plurality of second joining portions joined to the intermediate member and a plurality of second non-joining portions not joined to the intermediate member. The first joining portions and the first non-joining portions are arranged alternately along a first direction. The second joining portions and the second non-joining portions are arranged alternately along the first direction. The intermediate member has a plurality of intermediate forming members. Each of the plurality of intermediate forming members includes a first portion joined to at least a part of the first joining portion of the first skin member, a second portion joined to at least a part of the second joining portion of the second skin member, and a third portion connecting the first portion and the second portion, and not joined to the first joining portion and the second joining portion.

[0009] According to the above panel member, by having a sandwich structure with a corrugated intermediate member, both lightness and sufficient compressive strength can be obtained. Furthermore, since the intermediate member has multiple intermediate forming members, a configuration suitable for the applied product can be obtained by appropriately selecting the intermediate forming members. Therefore, it is highly versatile. For example, when the above panel member is used as a composite curvature surface member (a member having a curved surface with multiple curvatures), the desired strength can be obtained by arranging the intermediate forming members in a position and orientation that matches the overall shape of the composite curvature surface member. Therefore, it can be effectively applied to products of various shapes while possessing the expected lightness and compressive strength.

[0010] At least one of the plurality of intermediate forming members has a first intermediate forming portion in which a first number of continuous fibers are laminated, and a second intermediate forming portion in which a second number of continuous fibers are laminated, and the first number may be greater than the second number. With such a panel member, since the first number is greater than the second number, the first intermediate forming portion has higher strength than the second intermediate forming portion. Strength can be increased in parts where high strength is required locally without increasing the weight of other parts. At least one of the intermediate forming members may have three or more parts with different numbers of laminated continuous fibers.

[0011] The first jointed portion, the first non-jointed portion, the second jointed portion, and the second non-jointed portion may extend in a second direction different from the first direction. The first intermediate forming portion and the second intermediate forming portion may be aligned in the first direction or the second direction.

[0012] The first skin member and / or the second skin member has a first skin-forming portion in which a third number of continuous fibers are laminated, and a second skin-forming portion in which a fourth number of continuous fibers are laminated, wherein the third number may be greater than the fourth number. This makes it possible to increase the strength of the portion of the first skin member and / or the second skin member in which locally high strength is required compared to the strength of other portions. The first skin member and / or the second skin member may have three or more portions in which the number of laminated continuous fibers differs.

[0013] The first jointed portion, the first non-jointed portion, the second jointed portion, and the second non-jointed portion may extend in a second direction different from the first direction. The first skin-forming portion and the second skin-forming portion may be aligned in the first direction or the second direction.

[0014] In this way, by having different numbers of layers along each direction, it is possible to create panel components with the necessary strength for each part, according to the shape and application of the product. For example, unlike panel components with uniform thickness and strength, sufficient strength can be obtained in areas where strength is required by increasing the number of continuous fiber layers, and weight reduction can be achieved in areas where fewer layers are sufficient by reducing the number of continuous fiber layers. This makes it possible to create panel components that have flexible strength suitable for practical use and can also be made lighter.

[0015] The first jointed portion, the first non-jointed portion, the second jointed portion, and the second non-jointed portion may extend in a second direction different from the first direction. The panel member may include a cover member attached to the end of the first skin member, the second skin member, and the intermediate member in the second direction or the opposite direction of the second direction, and covering the area partitioned by the first skin member, the second skin member, and the intermediate member. The cover member may have a plurality of fixing surfaces fixed to at least two of the first skin member, the second skin member, and the intermediate member. By providing the cover member with the plurality of fixing surfaces described above, peeling of the intermediate member and the like can be effectively suppressed. As a result, the quality of the panel member can be maintained over a long period of time.

[0016] At least one of the intermediate forming members may have a hat-shaped cross-section. At least one of the intermediate forming members may have a roughly Z-shaped, roughly C-shaped, or roughly U-shaped cross-section.

[0017] At least one of the first skin member and the second skin member may be a composite curvature surface member. Multiple intermediate forming members can be arranged to match the shape of the first skin member and / or the second skin member, which are composite curvature surface members. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a highly versatile panel member that can achieve weight reduction and improved mechanical strength, and can be used in various applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] [Figure 1] Figure 1(a) is a perspective view of the panel member according to the first embodiment, and Figure 1(b) is a cross-sectional view of the panel member viewed in the X1-X1 direction of Figure 1(a). [Figure 2] Figure 2 is an exploded cross-sectional view of the panel member according to the first embodiment. [Figure 3] Figure 3 is a perspective view showing the longitudinal direction of the continuous fibers in the outermost layer of some members of the panel member according to the first embodiment. [Figure 4] Figure 4 is a schematic plan view showing each part of the panel member according to the first embodiment in a divided manner. [Figure 5] Figure 5 is a cross-sectional view of a different example of the panel member according to the first embodiment. [Figure 6] Figure 6(a) is a schematic diagram showing the arrangement of the panel member according to the second embodiment, Figure 6(b) is a rear view of the same panel member, Figure 6(c) is a cross-sectional view taken along line P1-P1 of Figure 6(b), and Figure 6(d) is a cross-sectional view taken along line P2-P2 of Figure 6(b). [Figure 7] Figure 7(a) is a perspective view of the panel member according to the third embodiment, Figure 7(b) is a side view of the same panel member, Figure 7(c) is a cross-sectional view taken along line P3-P3 of Figure 7(b), and Figure 7(d) is a cross-sectional view taken along line P4-P4 of Figure 7(b). DETAILED DESCRIPTION OF EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0020] Hereinafter, embodiments of the panel member will be described with reference to the drawings. Figure 1(a) is a schematic perspective view of the panel member 100 according to the first embodiment. The panel member 100 according to the present embodiment constitutes a part of an aircraft wing. X, Y, and Z shown in the drawings represent three directions orthogonal to each other. In the following description, the Y direction may be referred to as the rear, and the direction opposite to the Y direction may be referred to as the front. In addition, the Z direction may be referred to as the upper side, and the direction opposite to the Z direction may be referred to as the lower side.

[0021] The panel member 100 includes a first skin member 1, a second skin member 2, and an intermediate member 3 disposed between the first skin member 1 and the second skin member 2. Each of the first skin member 1 and the second skin member 2 is a sheet-like member containing a thermoplastic resin. The first skin member 1 and the second skin member 2 are spaced apart from each other in the Z direction. The intermediate member 3 contains continuous fibers.

[0022] The length L1 of the end portion of the panel member 100 in the direction opposite to the X direction is greater than the length L2 of the end portion in the X direction. The lengths L1 and L2 referred to herein are each a length in the Y direction. The first skin member 1 and the second skin member 2 each have a main surface extending in the X direction and the Y direction. The main surfaces of the first skin member 1 and the second skin member 2 are curved and have a plurality of curvatures. The curvatures of the main surfaces of the first skin member 1 and the second skin member 2 differ from part to part. In the panel member 100, the upper main surface (the first skin member 1) and the lower main surface (the second skin member 2) are each a composite curvature surface member having curvature anisotropy.

[0023] As shown in FIG. 1(b), the intermediate member 3 has a corrugated shape that conforms to the composite curvature surfaces of the first skin member 1 and the second skin member 2. The intermediate member 3 extends in the X direction. The first skin member 1, the second skin member 2, and the intermediate member 3 form a sandwich structure in which the intermediate member 3 serves as a core member. The first skin member 1, the second skin member 2, and the intermediate member 3 constitute a structure with high durability against stress changes generated on the main surfaces of the first skin member 1 and the second skin member 2.

[0024] The distance between the first skin member 1 and the second skin member 2 decreases towards the front and towards the rear. A solid (e.g., solid rod-shaped) rear edge member 4 is provided at the rear end of the panel member 100. A spar member 5 is provided at the front end of the panel member 100. The rear edge member 4 and the spar member 5 extend in the X direction. In this specification, extending in the X, Y, and Z directions includes not only extending in directions that strictly coincide with the X, Y, and Z directions, respectively, but also extending in directions that are slightly inclined from those directions. The spar member 5 has a substantially C-shaped cross-section. The contact portions of these members 1, 2, 3, 4, and 5 are welded together.

[0025] As shown in Figure 1(a), multiple cover members 6 are provided at the ends of the panel member 100 opposite to the X direction. The cover members 6 support the first skin member 1, the second skin member 2, the intermediate member 3, the trailing edge member 4, and the spar member 5. The cover members 6 also divide the panel member 100 into an inner region and an outer region. The rearmost cover member 6 is a filler member 6a that covers the region S1 (see Figure 1(b)) surrounded by the trailing edge member 4, the intermediate member 3, and the second skin member 2. This filler member 6a, like the other cover members 6, provides support for the panel member 100.

[0026] As shown in Figure 1(b), the first skin member 1 is used as the upper skin member of the panel member 100. The first skin member 1 is a carbon fiber reinforced composite material containing carbon fibers (e.g., PAN-based carbon fibers) in a thermoplastic resin (e.g., polyphenylene sulfide or ketone-based resin). Similarly, the second skin member 2 is also a carbon fiber reinforced composite material containing carbon fibers in a thermoplastic resin. The intermediate member 3 has a corrugated structure with multiple protrusions arranged in the Y direction. The intermediate member 3, like the first skin member 1 and the second skin member 2, is a carbon fiber reinforced composite material containing carbon fibers in a thermoplastic resin. Because the panel member 100 according to this embodiment is formed from the above-mentioned composite material, it is lightweight and has excellent strength and rigidity. Furthermore, because the panel member 100 contains carbon fibers, it also has excellent flame retardancy.

[0027] The first skin member 1 has joint portions C11, C12, C13 joined to the intermediate member 3, and non-joint portions NC11, NC12, NC13 not joined to the intermediate member 3. The intermediate member 3 is fixed to the joint portions C11, C12, C13 by welding. The non-joint portions NC11, NC12, NC13 are spaced apart from the intermediate member 3. The joint portions C11, C12, C13 and the non-joint portions NC11, NC12, NC13 are arranged alternately and continuously along the curved main surface of the first skin member 1. The joint portions C11, C12, C13 and the non-joint portions NC11, NC12, NC13 are arranged side by side in the Y direction. Both the joint portions C11, C12, C13 and the non-joint portions NC11, NC12, NC13 extend in the X direction (see Figure 1(a)). The thickness of the first skin member 1 is not uniform but varies partially in both the parallel installation direction (Y direction) and the stretching direction (X direction). Although not particularly limited, the thickness of the first skin member 1 is approximately 0.4 to 2.2 mm in this case.

[0028] The second skin member 2 has non-jointed portions NC21, NC22, NC23 that are not joined to the intermediate member 3, and joined portions C21, C22, C23 that are joined to the intermediate member 3. The intermediate member 3 is fixed to the joined portions C21, C22, C23 by welding. The non-jointed portions NC21, NC22, NC23 are spaced apart from the intermediate member 3. The joined portions C21, C22, C23 and the non-jointed portions NC21, NC22, NC23 are arranged alternately and continuously along the curved main surface of the second skin member 2. The joined portions C21, C22, C23 and the non-jointed portions NC21, NC22, NC23 are arranged side by side in the Y direction. Both the joined portions C21, C22, C23 and the non-jointed portions NC21, NC22, NC23 extend in the X direction. The thickness of the second skin member 2 is not uniform but varies partially in both the parallel installation direction and the stretching direction. Although not particularly limited, the thickness of the second skin member 2 is approximately 0.4 to 2.2 mm.

[0029] The intermediate member 3 has multiple separate members (hereinafter referred to as intermediate forming members). In this embodiment, the intermediate member 3 has three intermediate forming members M1, M2, and M3. The intermediate forming members M1, M2, and M3 are separately molded members and have different shapes from each other. As shown in Figure 1(b), the intermediate forming members M1, M2, and M3 each have lengths LM1, LM2, and LM3 along the main surface of the second skin member 2. Each of the intermediate forming members M1, M2, and M3 has a portion that contacts the first skin member 1 and a portion that contacts the second skin member 2. For example, the rearmost intermediate forming member M1 includes a portion M1a that contacts the joint portion C11 of the first skin member 1 (first skin contact surface portion), a portion M1c that contacts the joint portion C21 of the second skin member 2 (second skin contact surface portion), and a portion M1b that connects these two portions M1a and M1c and is not joined to the joint portions C11 and C21 (inclined surface portion). The above portion M1b is inclined in the Y direction and the Z direction.

[0030] As shown in Figure 1(b), the region enclosed by the first skin member 1, the second skin member 2, the trailing edge member 4, and the spar member 5 is divided into six regions S1, S2, S3, S4, S5, and S6 by three intermediate forming members M1, M2, and M3. The cover member 6 (see Figure 1(a)) has a first cover member 6a, a second cover member 6b, a third cover member 6c, a fourth cover member 6d, a fifth cover member 6e, and a sixth cover member 6f, each covering one of these regions S1 to S6. The foremost region S6 is provided with the sixth cover member 6f. The sixth cover member 6f has a vertical surface whose main surface is the YZ plane, and four fixed surface sections that are bent toward the front side (opposite direction to the X direction) in Figure 1(b) relative to this vertical surface. The vertical surface section has a shape that substantially matches the shape of region S6 shown in Figure 1(b). Each of the four fixed surfaces faces and is in contact with the non-jointed portion NC13 of the first skin member 1, the inclined surface portion M34 of the intermediate forming member M3, the jointed portion C23 of the second skin member 2, and the vertical surface portion 53 of the spar member 5. These four fixed surfaces are fixed to each of the facing portions by welding or via fasteners. The sixth cover member 6f covers region S6 by being fixed to multiple different portions in this way. By providing the six cover members (first to sixth cover members 6a to 6f) for the six regions S1 to S6, it is possible to suppress the peeling of the components of the panel member 100 (first skin member 1, second skin member 2, and intermediate member 3). In the panel member 100 according to this embodiment, as described above, the filler member 6a is used as the first cover member. However, depending on the size and shape of the region, the first cover member 6a may be configured similarly to at least one of the other cover members 6b to 6f.

[0031] As described above, the panel member 100 according to this embodiment has a composite curvature surface member, and the lengths L1 and L2 of the ends in the X direction and the opposite direction are different from each other. Therefore, the strength and other properties required of the panel member 100 differ from part to part. In this embodiment, intermediate forming members M1 to M3 are provided as shown in the schematic cross-sectional view of Figure 2 so as to conform to the shape of the panel member 100.

[0032] As described above, the first intermediate forming member M1 has a first upper surface portion M11 that contacts the joint portion C11, a first lower surface portion M13 that contacts the joint portion C21, and a first inclined surface portion M12 that connects the first upper surface portion M11 and the first lower surface portion M13. The first intermediate forming member M1 has a roughly Z-shaped cross-section. The first upper surface portion M11 is welded to the first skin member 1, and the first lower surface portion M13 is welded to the second skin member 2. In addition, the rear ends of the first skin member 1, the second skin member 2, and the first intermediate forming member M1 are welded to the rear edge member 4.

[0033] The second intermediate forming member M2 has a second rear lower surface portion M21 that contacts the joint portion C21, a second upper surface portion M23 that contacts the joint portion C12, a second front lower surface portion M25 that contacts the joint portion C22, a second rear inclined surface portion M22 that connects the second rear lower surface portion M21 and the second upper surface portion M23, and a second front inclined surface portion M24 that connects the second upper surface portion M23 and the second front lower surface portion M25. In this embodiment, the second rear lower surface portion M21 is spaced apart from the first lower surface portion M13, and a gap is formed between the second rear lower surface portion M21 and the first lower surface portion M13. The second intermediate forming member M2 has a hat-shaped cross-section. The second rear lower portion M21 and the second front lower portion M25 are welded to the second skin member 2, and the second upper portion M23 is welded to the first skin member 1.

[0034] The third intermediate forming member M3 has a third rear lower surface portion M31 that contacts the joint portion C22, a third upper surface portion M33 that contacts the joint portion C13, a third front lower surface portion M35 that contacts the joint portion C23, a third rear inclined surface portion M32 that connects the third rear lower surface portion M31 and the third upper surface portion M33, and a third front inclined surface portion M34 that connects the third upper surface portion M33 and the third front lower surface portion M35. In this embodiment, the third rear lower surface portion M31 is spaced apart from the second front lower surface portion M25, and a gap is formed between the third rear lower surface portion M31 and the second front lower surface portion M25. The third intermediate forming member M3 has a hat-shaped cross-section. The third rear lower portion M31 and the third front lower portion M35 are welded to the second skin member 2, and the third upper portion M33 is welded to the first skin member 1. A spur member 5 is interposed between the third front lower portion M35 and the first skin member 1. The first skin member 1, the second skin member 2, and the third intermediate forming member M3 are supported by the spur member 5.

[0035] In the panel member 100 having a composite curvature surface member as in this embodiment, the intermediate member 3 has portions that contact the first skin member 1 and the second skin member 2 (i.e., an upper surface portion and a lower surface portion), as well as a connecting portion (i.e., an inclined surface portion) that connects these portions. As a result, the panel member 100 can have the desired strength against compressive loads. Furthermore, by combining multiple intermediate forming members M1, M2, and M3, the panel member 100 can be made into a desired shape, and strength that matches its overall shape can be obtained. In this embodiment, the intermediate forming member M1 has a roughly Z-shaped cross-section, and the intermediate forming members M2 and M3 have hat-shaped cross-sections, but the combination of the cross-sectional shapes of the intermediate forming members M1 to M3 can be changed as appropriate, and it is also possible to match them to only one of the shapes. Naturally, if a similar effect is achieved, the intermediate forming members M1 to M3 may have other cross-sectional shapes (for example, a roughly C-shaped or roughly U-shaped cross-section). Also, the number of intermediate forming members can be changed as appropriate to match the overall shape of the panel member 100. For example, the configuration may not only consist of multiple intermediate forming members having a hat-shaped cross-section spaced apart from one another, but also of multiple intermediate forming members arranged continuously without gaps to match the overall shape of the panel member 100.

[0036] Next, the orientation of the carbon fibers (continuous fibers) in the panel member 100 will be explained using Figure 3. Here, the third intermediate forming member M3 will be used as a representative example. Figure 3 is an exploded perspective view of the first skin member 1, the third intermediate forming member M3, and the second skin member 2.

[0037] The first skin member 1 has multiple layers stacked in the Z direction. Carbon fibers 11 are contained in each layer of the first skin member 1. As shown in Figure 3, the uppermost layer of the first skin member 1 contains multiple carbon fibers 11 extending in the Y direction. The curvature of the first skin member 1 differs from part to part. The number of layers of the first skin member 1 differs from part to part so that the first skin member 1 has a desired shape that conforms to the overall shape of the panel member 100. For example, in the area shown in Figure 3, the part that will become the non-jointed part NC13 (see Figure 1(b)) has 12 layers. In the multiple stacked layers, for example, the carbon fibers 11 are oriented in a pattern such as 45 degrees, 0 degrees, -45 degrees, 90 degrees, 90 degrees, -45 degrees, 0 degrees, and 45 degrees. The first skin member 1 has multiple layers stacked in a pseudo-isotropic manner. The part that will become the jointed part C13 has 6 layers. Similarly, in these six layers, the carbon fibers 11 are appropriately oriented to form a pseudo-isotropic laminate. The non-bonded portion NC12 has nine layers. In these layers as well, the carbon fibers 11 are oriented to form a pseudo-isotropic laminate. The longitudinal direction of the carbon fibers 11 in the uppermost layer of the first skin member 1 is 45 degrees. In this embodiment, the carbon fiber content of the first skin member 1 is 60% by mass, but it can be appropriately changed between 40% and 70% by mass, with 55% to 70% by mass being particularly preferred. The orientation of the carbon fibers 11 in the multiple layers may be in combinations other than those described above. Furthermore, even with the combinations of angles described above, the order in which they are laminated may differ from those described above.

[0038] The second skin member 2 has multiple layers stacked in the Z direction. Carbon fibers 12 are contained in every layer of the second skin member 2. Similar to the first skin member 1, the number of layers in the second skin member 2 varies from section to section. For example, in the area shown in Figure 3, the section that becomes the joint C23 has eight layers. In these layers, the carbon fibers 12 are oriented at 45 degrees, 0 degrees, -45 degrees, 90 degrees, 90 degrees, -45 degrees, 0 degrees, and 45 degrees. The second skin member 2 has multiple layers stacked in a pseudo-isotropic manner. The section that becomes the non-joined section NC23 has 12 layers. In these layers as well, the carbon fibers 12 are oriented in a pseudo-isotropic manner. The section that becomes the joint C22 has four layers, and the carbon fibers 12 are similarly oriented in these layers. The longitudinal direction of the carbon fibers 12 in the bottommost layer of the second skin member 2 is 45 degrees. The carbon fiber content of the second skin member 2 is 60% by mass, but can be appropriately changed between 40% and 70% by mass, with 55% to 70% by mass being particularly preferred. Regarding the orientation of the carbon fibers 12 in the multiple layers, combinations other than those described above are acceptable. Furthermore, even with the combinations of angles described above, the stacking order may differ from those described above.

[0039] The uppermost layer of the intermediate member 3 contains multiple carbon fibers 13 extending in the Y direction. Similar to the first skin member 1 and the second skin member 2, the number of layers in the intermediate member 3 varies from section to section. For example, in the area shown in Figure 3, the third rear lower surface M31 of the third intermediate forming member M3 has 4 layers, the third rear inclined surface M32 has 8 layers, the third upper surface M33 has 4 layers, the third front inclined surface M34 has 8 layers, and the third front lower surface M35 has 4 layers. In each of the surfaces M31 to M35, the longitudinal direction of the carbon fibers 13 in the uppermost layer is 45 degrees. In each of the surfaces M31 to M35, multiple layers are laminated in a pseudo-isotropic manner. The intermediate member 3 according to this embodiment has multiple hat-shaped members and Z-shaped members, each having multiple layers laminated in a pseudo-isotropic manner. This allows the panel member 100 to exhibit high strength against external compression. In particular, aircraft wings require suitable performance against compressive stress, bending stress, shear stress, and tensile stress not only in one direction but in multiple directions. The intermediate member 3 according to this embodiment is suitable in that it provides suitable performance in these areas. The carbon fiber 13 content in the intermediate member 3 is 60 mass%, but can be appropriately changed between 40 and 70 mass%, with 55 to 70 mass being particularly preferred. Similar to the first skin member 1 and the second skin member 2, the orientation of the carbon fibers 13 in the multiple layers of the intermediate member 3 may be in combinations other than the angles described above. Furthermore, even with the combinations of angles described above, the stacking order may differ from the stacking order described above.

[0040] As described above, the first skin member 1, the second skin member 2, and the intermediate member 3 each have multiple layers with different numbers of layers in each section. The first skin member 1, the second skin member 2, and the intermediate member 3 can be formed by creating a desired number of laminates of carbon fibers 11, 12, and 13 in each section and impregnating the spatial regions formed between the carbon fibers 11, 12, and 13 with a thermoplastic resin.

[0041] In the production of the first skin member 1 and the second skin member 2, base materials with different numbers of carbon fiber layers 11 and 12 in each section are prepared, and sheet materials are formed by impregnating these base materials with thermoplastic resin. Then, the sheet materials are molded as needed. In the production of the intermediate forming members M1, M2, and M3 of the intermediate member 3, base materials with different numbers of carbon fiber layers 13 in each section are prepared, and sheet materials are formed by impregnating these base materials with thermoplastic resin. Then, these sheet materials are molded into the shapes described above using a press machine.

[0042] The impregnated thermoplastic resin facilitates the joining of the skin member 1 to the intermediate member 3, and the joining of the skin member 2 to the intermediate member 3. A mold suitable for the shape of the desired panel member 100 is placed above the first skin member 1 and below the second skin member 2, and a pressing process is performed using this mold. During this pressing process, the mold is subjected to heating and cooling processes. For the intermediate member 3, contact members (cores) suitable for the shape of each region S1 to S6 (see Figure 1(b)) are placed in regions S1 to S6, and the above joining process is performed. In particular, in this embodiment, the intermediate forming members M1, M2, and M3 each have different shapes. Furthermore, each intermediate forming member M1, M2, and M3 has different shapes, number of layers, and thickness in different parts. Therefore, multiple contact members suitable for each part are placed. The extraction of the contact members is performed individually for each.

[0043] As shown in the plan view of Figure 4, the first skin member 1 has multiple divided parts such as parts S11, S12, S13, ..., S31, S32, S33, ..., S61, S62, S63, ..., and each part has a desired number of layers. The first skin member 1 has at least two parts with different numbers of layers in the direction (X direction) in which the joined parts C11, C12, C13 and the non-jointed parts NC11, NC12, NC13 are arranged side by side. Furthermore, the first skin member 1 has at least two parts with different numbers of layers in the direction (Y direction) in which the joined parts C11, C12, C13 and the non-jointed parts NC11, NC12, NC13 are extended. The number of layers in a predetermined part of the first skin member 1 is greater than the number of layers in other predetermined parts. Although not shown in the diagram, the second skin member 2 and the intermediate member 3 also have at least two or more sections with different numbers of layers in the parallel arrangement direction and / or the extension direction. However, the number and size of the sections of the second skin member 2 and the intermediate member 3 differ from those of the first skin member 1.

[0044] The carbon fibers 11, 12, and 13 are continuous fibers (long fibers) that extend in one direction. For example, when continuous fibers are included in a panel member with a constant surface curvature or a panel member with the same length at both ends, the intersection angle of the carbon fibers remains constant and does not change from section to section. On the other hand, the panel member 100 according to this embodiment has anisotropy, and the lengths L1 and L2 at the ends are different (see Figure 1(a)). Therefore, the intersection angles of the carbon fibers are not uniform, and differences occur from section to section. However, the intermediate member 3 has multiple intermediate forming members M1, M2, and M3. Since the orientation and position of the intermediate forming members M1, M2, and M3 can be flexibly set, the effects of the above-mentioned differences in intersection angles can be suppressed. Specifically, the variation in the above-mentioned intersection angles from section to section can be made substantially uniform. Differences in the above-mentioned intersection angles caused by differences in surface curvature can be suppressed. Alternatively, the intermediate forming members M1, M2, and M3 can be set to different states so that the difference in intersection angles is of a predetermined size, in accordance with the desired shape and strength of the panel member 100. In other words, each intermediate forming member M1, M2, and M3 can be positioned according to the desired strength and required panel shape. The orientation and position of each intermediate forming member M1, M2, and M3 can be adjusted as appropriate.

[0045] Furthermore, since the intermediate forming members M1, M2, and M3 are arranged individually, their shape, size, and number of layers can be set individually. It is easy to appropriately vary the number of layers in the extension direction of the intermediate forming members M1, M2, and M3. As shown in Figure 4, by setting the number of layers for each part of the first skin member 1, the second skin member 2, and the intermediate member 3 to the appropriate number of layers, the panel member 100 including the composite curvature surface member can be made into a desired shape and the desired strength can be met. In addition, the variations can be diversified (generalized). The desired strength is set according to the suitability of the composite curvature surface member to the curvature and the suitability based on the connection structure to the main wing section.

[0046] Figure 5 shows different examples of intermediate forming members. As shown in Figure 5, the intermediate member 3 may include intermediate forming members M10, M20, and M30 that are butted against each other. Intermediate forming members M10 and M20 are in contact with each other, and intermediate forming members M20 and M30 are in contact with each other. Although not shown in the figure, the intermediate member 3 may also include intermediate forming members that are butted against each other and intermediate forming members that are spaced apart from each other (see Figure 1(a)). By cleverly combining multiple intermediate forming members, a suitable panel member 100 that satisfies various application and shape requirements can be realized.

[0047] The panel member 100 according to this embodiment has high durability against out-of-plane compression. When a pressure load is applied to the first skin member 1 from above, the panel member 100 is compressed in its thickness direction (Z direction). In this case, since the carbon fibers 11, which are continuous fibers, are oriented as described above, high durability can be achieved. Furthermore, the first skin member 1 is subjected to compressive loads from various directions. The intermediate member 3, which has a pseudo-isotropic laminated structure, supports the first skin member 1, and the effect of improving durability is significantly demonstrated. In addition, various concentrated stresses may occur in the corner portions of the intermediate member 3 (for example, as shown in Figure 1(b), portions R1, R2, etc., where the part that is joined to the first skin member 1 changes to a part that is not joined) in response to pressure loads from various directions. However, the pseudo-isotropic laminated structure functions suitably against these concentrated stresses. As a result, the shape of the first skin member 1 is stably maintained over a long period of time. Furthermore, the overall shape of the panel member 100 is well maintained. Therefore, the strength against out-of-plane compression as described above is improved. The laminated layers contain carbon fibers 11, 12, and 13 oriented at 45 degrees. This improves the strength against shear force within the panel surface. The panel member 100 exhibits the same effect even when subjected to a pressure load from below on the second skin member 2. The orientation of the panel member 100 can be changed as appropriate. The panel member 100 can be effectively applied to specifications and applications where a pressure load is applied to the first skin member 1, and / or where a pressure load is applied to the second skin member 2. In other words, the panel member 100 according to this embodiment is a highly versatile panel member.

[0048] Regarding this out-of-plane compression, the shapes of the intermediate forming members M1, M2, and M3 also contribute to the improvement of strength. For example, each of the intermediate forming members M1, M2, and M3 has at least a portion that joins to the first skin member 1 (upper surface), a portion that joins to the second skin member 2 (lower surface), and a portion that connects both portions (inclined surface). These three portions are integrally molded. Therefore, the intermediate forming members M1, M2, and M3 can easily change shape in response to pressure loads. The intermediate forming members M1, M2, and M3 can exhibit high durability when subjected to the above-mentioned pressure loads. In particular, since these three portions contain a common continuous carbon fiber 13, their durability is improved.

[0049] The panel member 100 is equipped with a corrugated intermediate member 3, which provides strong compressive strength during flight and minimal deterioration over time. In the panel member 100, the thickness of each member 1, 2, and 3 can be flexibly set as appropriate depending on the combination of the first skin member 1, the second skin member 2, and the intermediate member 3. The optimal combination of each member 1, 2, and 3 can be achieved for the panel member 100 as a whole. When the panel member 100 is used as an aileron connected to the main wing, it can appropriately address the need to ensure a predetermined strength for the connecting member. In this embodiment, each of the first skin member 1, the second skin member 2, and the intermediate member 3 has the above-mentioned pseudo-isotropic laminated structure, and a synergistic effect can be achieved based on the characteristics of each. Furthermore, this synergistic effect is further enhanced by the panel member 100 having a composite curvature surface member, which is preferable. However, depending on various design conditions, only one of the first skin member 1, the second skin member 2, and the intermediate member 3 may have a pseudo-isotropic laminated structure. These features and effects represent significant differences compared to panel members with uniform thickness or single-curvature surface members. Panel member 100 offers greater design flexibility and improved versatility.

[0050] Furthermore, since the intermediate member 3 is welded to the first skin member 1 and the second skin member 2 of the panel member 100, the smoothness of the outer surface can be ensured. Moreover, because of its high durability against out-of-plane compression, its smoothness can be maintained over a long period of time. In addition, the provision of the cover member 6 described above improves the peel strength of the panel member 100 assembled by welding.

[0051] The effects are not limited to the configurations and shapes described above, and similar effects can be obtained with other configurations and shapes. For example, in the above embodiment, the shapes of the intermediate forming members M1, M2, and M3 are all different, but they may all be the same shape if it is possible to achieve the desired shape, strength, or durability performance for the panel member 100. Also, only some of the multiple intermediate forming members may have the same shape as each other. Another embodiment will be described using Figure 6. The following description will mainly focus on the differences from the above embodiment.

[0052] Figure 6(a) is a schematic diagram showing a panel member 200 according to a second embodiment. The panel member 200 is used in a pressure bulkhead located on the rear side of an aircraft. The panel member 200 has a dome-shaped surface containing a thermoplastic resin.

[0053] Figure 6(b) is a rear view of the panel member 200 as seen from the rear. The panel member 200 has a first skin member 201 that forms the outer surface, a second skin member 202 that forms the inner surface, and an intermediate member 203 interposed between them and containing continuous fibers. The first skin member 201 and the second skin member 202 have curved main surfaces with multiple curvatures. Multiple intermediate members 203 are provided along their main surfaces.

[0054] In this embodiment, the intermediate member 203 has seven radially arranged intermediate forming members 2031, 2032, 2033, 2034, 2035, 2036, and 2037 (see Figure 6(b)). The first intermediate forming member 2031 is the longest member. The second intermediate forming member 2032 and the third intermediate forming member 2033 are provided so as to intersect with the first intermediate forming member 2031. The fourth intermediate forming members 2034 to the seventh intermediate forming members 2037 are provided between the first intermediate forming member 2031 and the second intermediate forming member 2032, and between the first intermediate forming member 2031 and the third intermediate forming member 2033. Each intermediate forming member 2031 to 2037 has a hat-shaped cross-section, as can be seen from Figures 6(c) and 6(d).

[0055] The panel members disclosed herein are suitable for composite curvature surface members. Panel member 200 is used in pressure bulkheads and helps maintain stable air pressure inside an aircraft. In particular, panel member 200 has high durability against out-of-plane pressure, so it can suppress aging and is suitable as a member that can maintain stable performance over a long period of time.

[0056] As described above, the panel members 100 and 200 according to the first and second embodiments have been explained. The type of thermoplastic resin included in the first skin members 1 and 201 and the second skin members 2 and 202 is not particularly limited, and polyphenylene sulfide, ketone resin, or other resins can be used. Thermoplastic resins mainly use materials with high melting points. Materials with high melting points are excellent in terms of forming resins with high strength. However, thermoplastic resins are not limited to these materials, and other materials may be used. The same type of thermoplastic resin may also be used for the intermediate member 3 and 203.

[0057] Examples of carbon fibers used include PAN-based carbon fibers and PITCH-based carbon fibers. However, the application is not limited to the above-mentioned carbon fibers; continuous fibers such as glass fibers (e.g., E-glass fibers) can also be used. The longitudinal direction of these continuous fibers may coincide with the X or Y direction. Note that "coinciding with the X and Y directions" includes not only cases where the fibers are exactly aligned with the X and Y directions, but also cases where they are slightly tilted from the X and Y directions, respectively. Even with a slight tilt, the same effect can be obtained.

[0058] Regarding the thermoplastic resin and continuous fibers in the first skin member 1,201, the second skin member 2,202, and the intermediate member 3,203, different materials may be used for some of the members or for all of the members. In the above embodiment, the first skin member 1,201 and the intermediate member 3,203 are welded together. Also, the second skin member 2,202 and the intermediate member 3,203 are welded together. Therefore, a major feature is that these members are formed from the same type of material. According to the above embodiment, it is possible to achieve high recyclability and shorten the manufacturing lead time, and the effect increases as the same type of material (identical material) is used.

[0059] Furthermore, the panel members disclosed herein are not limited to the panel members 100 and 200 of the above embodiment used as components of ailerons and pressure bulkheads, but can also be applied to other aircraft components, such as the outer skin of the fuselage F as shown in Figure 7. The outer skin of the fuselage F is composed of annular panel members 300. The annular panel members 300 have high strength (rigidity) against out-of-plane compression. The panel members 300 have an outer skin member 301, an inner skin member 302, and a corrugated intermediate member 303 as shown in the figure, resulting in weight reduction and reduced manufacturing costs compared to conventional fuselages due to the reduction in the number of components. In addition, since the panel members 300 have two types of skin members, an outer skin member (first skin member) 301 and an inner skin member (second skin member) 302, it can exhibit a pressurization fail-safe function. Furthermore, the intermediate member 303 has multiple intermediate forming members, similar to other embodiments. This makes it possible to create an aircraft fuselage F with uniform strength in an annular shape. By appropriately setting the shape and number of layers of the intermediate forming member (note that different numbers of layers result in different thicknesses), and the number of layers of the outer skin member 301 and inner skin member 302, it is possible to create a configuration in which desired parts have different strengths than other parts. Therefore, the strength and other properties can be flexibly set according to the specifications required for the aircraft fuselage F. This improves the durability and weight reduction of the aircraft fuselage F, increasing its versatility. Furthermore, it can also be applied to other aircraft components, such as the upper surface skin of the main wing. The panel members disclosed herein have high compressive strength during flight, resulting in weight reduction and reduced manufacturing costs. Moreover, the panel members disclosed herein can similarly demonstrate significant effects not only in aircraft but also in other fields, such as vehicles, railways, or underwater moving objects, as well as structures such as offshore wind power generation and disaster prevention infrastructure equipment such as shelters, particularly in fields where composite curvature surface members are required. [Explanation of Symbols]

[0060] 1. First skin member 2. Second skin member 3 Intermediate members 4. Rear edge member 5 Spar members 6 Cover component C11,C12,C13 joint part (first joint part) NC11,NC12,NC13 Non-joint part (1st non-joint part) C21,C22,C23 joint part (second joint part) NC21,NC22,NC23 Non-joint part (2nd non-joint part) M1,M2,M3 Intermediate forming parts 11,12,13 Carbon fiber 100 Panel components

Claims

1. A sheet-like first skin member and a second skin member containing a thermoplastic resin, The device comprises an intermediate member containing continuous fibers and disposed between the first skin member and the second skin member, The first skin member has a plurality of first joining portions joined to the intermediate member and a plurality of first non-joining portions not joined to the intermediate member, The second skin member has a plurality of second joining portions joined to the intermediate member and a plurality of second non-joining portions not joined to the intermediate member, The first joint portion and the first non-joint portion are arranged alternately along the first direction. The second joint portion and the second non-joint portion are arranged alternately along the first direction, The aforementioned intermediate member has a plurality of intermediate forming members, Each of the plurality of intermediate forming members includes a first portion joined to at least a part of the first joining portion of the first skin member, a second portion joined to at least a part of the second joining portion of the second skin member, and a third portion connecting the first portion and the second portion, and not joined to the first joining portion and the second joining portion. At least one of the plurality of intermediate forming members is a panel member having a hat-shaped cross-section.

2. At least one of the plurality of intermediate forming members has a first intermediate forming portion in which the continuous fibers are stacked a first number of times, and a second intermediate forming portion in which the continuous fibers are stacked a second number of times, The panel member according to claim 1, wherein the first number is greater than the second number.

3. The first jointed portion, the first non-jointed portion, the second jointed portion, and the second non-jointed portion extend in a second direction different from the first direction. The panel member according to claim 2, wherein the first intermediate forming portion and the second intermediate forming portion are arranged in the first direction or the second direction.

4. The first skin member and / or the second skin member has a first skin-forming portion in which a third number of continuous fibers are laminated, and a second skin-forming portion in which a fourth number of continuous fibers are laminated, The panel member according to claim 1, wherein the third number is greater than the fourth number.

5. The first jointed portion, the first non-jointed portion, the second jointed portion, and the second non-jointed portion extend in a second direction different from the first direction. The panel member according to claim 4, wherein the first skin-forming portion and the second skin-forming portion are aligned in the first direction or the second direction.

6. The first jointed portion, the first non-jointed portion, the second jointed portion, and the second non-jointed portion extend in a second direction different from the first direction. The first skin member, the second skin member, and the intermediate member are attached to the ends in the second direction or the opposite direction of the second direction, and include a cover member that covers the area partitioned by the first skin member, the second skin member, and the intermediate member. The panel member according to claim 1, wherein the cover member has a plurality of fixing surfaces that are fixed to at least two of the first skin member, the second skin member, and the intermediate member.

7. The panel member according to claim 1, wherein at least one of the first skin member and the second skin member is a composite curvature surface member.

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