JP7746697B2 - Structures and their usage - Google Patents

Description

The present invention relates to a structure and a method for using the same. More specifically, it relates to a fiber-reinforced structure using continuous fibers and a method for using the same.

In recent years, attempts have been made to replace structural materials that have traditionally been made using metal with resin. Among these, fiber-reinforced resins, and in particular carbon fiber-reinforced plastics (CFRP), which use carbon fiber as the reinforcing fiber, have attracted attention. Fiber-reinforced resins are seen as promising because they have excellent strength and rigidity, and can be made lighter than metals. For example, a vehicle seat disclosed in Patent Document 1 below is known as an example of a structure that uses fiber-reinforced resin.

Japanese Patent Application Laid-Open No. 2015-193303

The above-mentioned Patent Document 1 discloses a structure (vehicle seat) in which a reinforcing member 50 protrudes from an occupant seating surface to an opposite surface of a seat shell (back pan 32) through a through-hole 36 communicating with the occupant seating surface side and the opposite surface. The back pan 32 is exemplified by a fiber-reinforced plastic injection-molded composite resin in which carbon fibers having a fiber length of approximately 1 mm are used as a reinforcing material and polypropylene is used as a matrix resin. The reinforcing member 50 is exemplified by a fiber-reinforced plastic in which a woven fabric made of continuous carbon fibers is used as a reinforcing material and polypropylene is used as a matrix resin. While Patent Document 1 provides a high-strength vehicle seat, a greater variety of high-strength structures is desired.
The present invention has been made in view of the above circumstances, and has as its object to provide a high-strength structure with a novel configuration and a method for using the same.

That is, the present invention is as follows.
[1] The structure of the present invention has a structural part integrally formed with one or more bead portions, and a reinforcing band provided along the bead portion,
The bead portion is shaped to have a concave rib on one surface side of the structural portion and a convex rib on the opposite surface side,
the reinforcing band includes continuous fibers bound with a matrix resin and is integrally joined to the bead portion along the concave and/or convex surfaces of the bead portion;
The continuous fibers are laid along the extension direction of the bead portion.
[2] In the structure of the present invention, the reinforcing portion including the reinforcing band may be thicker than the surrounding area of the reinforcing portion not including the reinforcing band.
[3] In the structure of the present invention, the structural part may be made of a fiber-reinforced resin containing dispersed discontinuous fibers and/or a fiber-reinforced resin containing a woven fabric using continuous fibers.
[4] In the structure of the present invention, the reinforcing band may comprise a fiber bundle formed by bundling the continuous fibers, a base fabric to which the fiber bundle is sewn, and the matrix resin impregnated and fixed into the fiber bundle and the base fabric.
[5] In the structure of the present invention, the reinforcing band may have a transition region in the matrix resin on the bonding surface side with the bead portion.
[6] In the structure of the present invention, the bead portion may have a fastening structure for fastening to another structure.
[7] The structure of the present invention may be a back shell of a vehicle seat.
[8] The method of using the structure of the present invention is summarized as follows: the recessed portion of the bead portion is used as a laying space for laying an elongated object.
[9] Another method of using the structure of the present invention is to utilize the grooves in the bead portion as a flow path for fluid.

According to the structure of the present invention, a high-strength structure can be obtained by a novel configuration.
According to the method of using the structure of the present invention, the reinforcing structure can be effectively utilized not only for reinforcement but also for the purpose of obtaining other effects.

The present invention will be further described in the following detailed description, which provides non-limiting examples of exemplary embodiments according to the present invention, and with reference to the mentioned drawings, in which like reference numerals refer to like parts throughout the several views of the drawings.
FIG. 1 is an explanatory diagram showing an example of the structure. FIG. 10 is an explanatory diagram showing another example of the structure. 10A and 10B are explanatory diagrams showing variations of the present structure. FIG. 10 is an explanatory diagram showing yet another example of the structure. FIG. 2 is a perspective view of a seat back frame (assembled state) according to the embodiment. FIG. 2 is a perspective view of a seat back frame (disassembled state). FIG. 6 is a cross-sectional view taken along line III-III in FIG. 5. FIG. 8 is an enlarged view of a main part of FIG. 7 . 1 is a side view of a vehicle seat according to an embodiment; 10A and 10B are explanatory diagrams illustrating variations in the extending direction of the bead portion.

The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of the embodiments of the present invention, with the aim of providing what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this respect, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, and the description, taken together with the drawings, will make clear to those skilled in the art how some aspects of the present invention may be actually embodied.
In this specification, unless otherwise specified, the expression "XX to YY" means "XX or more and YY or less."

[1] Structure The structure (16) of the present invention comprises a structural part (17) having a bead part (30) and a reinforcing band (50) provided along the bead part (30). The bead part (30) is shaped to have a concave ridge on one side (17a) of the structural part (17) and a convex ridge on the opposite side (17b). Furthermore, the bead part (30) is shaped integrally with the structural part (17) and has one or more ridges.
On the other hand, the reinforcing band (50) comprises a matrix resin (51) and continuous fibers (52), and the continuous fibers (52) are contained in the reinforcing band (50) in a state where they are bound by the matrix resin (51). Furthermore, the reinforcing band (50) is integrally joined to the bead portion (30) along the concave surface (30a) and/or the convex surface (30b) of the bead portion (30), and the continuous fibers (52) are laid along the extension direction of the bead portion (30) (see Figures 1 to 4).

By providing the structure 16 with both the bead portion 30 and the reinforcing band 50, the structure 16 can be made to have high strength.
The shape and size of the structure 17 are not limited. The shape of the structure 17 can be, for example, a three-dimensional shape having projections and recesses. Furthermore, it can include a curved shape, a flat shape, etc. These shapes may include only one type, or two or more types at the same time. That is, for example, it can be a three-dimensional shape that includes a composite of a projection and recess shape, a curved shape, and a flat shape. In addition, it can have a cylindrical shape, a polygonal tube shape, etc.
The structural portion 17 is preferably shell-shaped in order to achieve both lightness and strength. The shell shape can be defined as a shape having a generally concave shape that widens toward the center. For example, as described below, a back shell of a vehicle seat can be cited as a typical example.

The material of the structural part 17 is also not limited, but resin can be used to achieve both lightness and strength. The type of resin is not limited, and it can be a thermoplastic resin or a curable resin (various curable resins regardless of the curing method), and they can even be used in combination depending on the purpose. That is, for example, a structure can be injection-molded using a thermoplastic resin. Furthermore, the structural part 17 can be formed only from resin, but can also contain reinforcing fibers to improve strength. That is, the structural part 17 can be formed using a fiber-reinforced resin that contains a resin (matrix resin) and reinforcing fibers bound by the resin.

Among the resins that can constitute the structural portion 17 (matrix resins when reinforcing fibers are included), examples of thermoplastic resins include polyolefins, polyesters, polyamides, polycarbonates, acrylic resins, fluorine-containing thermoplastic resins, polyimides, polyamideimides, and even resin alloys (composite resins) containing two or more of these thermoplastic resins. These may be used alone or in combination of two or more. On the other hand, examples of curable resins include epoxy resins, unsaturated polyester resins, phenolic resins, urea resins, melamine resins, diallyl phthalate resins, and vinyl ester resins. These may be used alone or in combination of two or more.

The reinforcing fibers may be continuous or discontinuous, or a combination of both may be used. Continuous fibers typically have a fiber length of 15 mm or more, while discontinuous fibers typically have a fiber length of less than 15 mm. When discontinuous fibers are used, a mixture of resin and discontinuous fibers can be injection molded. The injection-molded structural part 17 becomes a fiber-reinforced resin in which discontinuous fibers are dispersed within the resin. On the other hand, when continuous fibers are used, the resulting fiber-reinforced resin is one in which the continuous fibers are bonded together with the resin. The continuous fibers may be contained in the fiber-reinforced resin in a simply aligned state, or may be contained as a woven fabric, etc.

The material constituting the reinforcing fibers is not limited, and may be inorganic fibers, organic fibers, or a combination of these.
Examples of inorganic fibers include carbon fibers, activated carbon fibers, glass fibers, ceramic fibers (silicates, titanates, alumina, etc.), metal fibers, boron fibers, etc. These may be used alone or in combination of two or more.
Examples of organic fibers include natural fibers and synthetic fibers. These may be used alone or in combination of two or more. Among these, synthetic fibers include fibers formed from synthetic resins. Examples of such synthetic resin fibers include polyamide resin fibers (aliphatic polyamides (such as nylon fibers), aromatic polyamides (such as aramid fibers, trade name "Kevlar")), polyester resin fibers (such as aliphatic polyesters and aromatic polyesters (such as polyethylene terephthalate fibers and polyethylene naphthalate fibers)), polyolefin resin fibers (such as high molecular weight polyolefins (such as "Dyneema")), and polybenzazole resin fibers (such as polyparaphenylene benzobisoxazole fibers (such as "Zylon")).

The reinforcing fibers are preferably fibers having high tensile strength, for example, fibers having a tensile strength of 7 cN/dtex or more (usually 50 cN/dtex) according to JIS L1015.
Furthermore, the form of the reinforcing fiber is not limited, and it may be a spun yarn, a filament yarn, or a combination of these. Furthermore, it may be a monofilament, a multifilament, or a combination of these.

Of the above, carbon fiber is particularly preferred for the present structure 16. There are no limitations on the type of carbon fiber, and examples include PAN (polyacrylonitrile)-based carbon fiber and pitch-based carbon fiber. These may be used alone or in combination of two or more types.
The carbon fibers can be used as filaments or as bundles (tows). The number of carbon fibers constituting the bundle is not limited and can be, for example, 3,000 or more. By having 3,000 or more continuous fibers constituting the bundle, the core material can exhibit excellent strength while being flexible. The number of continuous fibers can be, for example, 3,000 to 100,000, further 5,000 to 70,000, further 7,000 to 50,000, or further 10,000 to 30,000.

The bead portion 30 is a portion shaped to form a concave ridge on one side 17a of the structural portion 17 and a convex ridge on the opposite side 17b. The bead portion 30 is a part of the structural portion 17 and is an integral part shaped integrally with the structural portion 17. By providing the bead portion 30, the strength and rigidity of the structure 16 are improved compared to when the bead portion 30 is not provided. Furthermore, as described above, the bead portion 30 is shaped to form a concave ridge on one side 17a of the structural portion 17 and a convex ridge on the opposite side 17b, so that the bead portion, which is a reinforcing structure, can be made thin. Therefore, significant strength reinforcement can be achieved while minimizing an increase in the weight of the structure 16.
Furthermore, the bead portion 30 may be recessed toward either the front or back side of the structural portion 17, or may protrude toward either side; however, for example, if the structural portion 17 is shell-shaped, it is preferable that the bead portion 30 is also recessed on the side where the general shape of the structural portion 17 is recessed, and that the bead portion 30 is also protruded on the side where the general shape of the structural portion 17 is protruded.

As described above, the bead portion 30 may have a concave rib on one side 17a of the structural portion 17 and a convex rib on the opposite side 17b, and its cross-sectional shape is not limited, but examples include a U-shape, a C-shape, a cup-shape, an arc-shape, a V-shape, etc.
Among these, the U-shape includes a configuration in which the pair of side walls 41 are provided opposite each other and a connecting wall 42 connecting the edges of the pair of side walls 41, the pair of side walls 41 are arranged substantially parallel to each other in a substantially flat plate shape, and the connecting wall 42 is curved so as to be concave inward. Also included is a configuration in which the pair of side walls 41 provided in this U-shape are arranged so that the distance between the side walls 41 increases toward the open end.
The U-shaped configuration also includes a configuration in which the pair of side walls 41 are opposed to each other and a connecting wall 42 that connects the edges of the pair of side walls 41, and the pair of side walls 41 are arranged approximately parallel to each other in a roughly flat plate shape, and the connecting wall 42 is arranged approximately perpendicular to the side walls in a roughly flat plate shape.
Furthermore, the cup shape (see Figures 1 to 4) includes a pair of side walls 41 facing each other and a connecting wall 42 connecting the edges of the pair of side walls 41, and includes an embodiment in which the pair of side walls 41 are arranged non-parallel to each other in a substantially flat plate shape, the side walls 41 are connected to the connecting wall 42 at an angle exceeding 90 degrees, and the pair of side walls 41 are arranged such that the distance between the side walls 41 increases toward the open end.
The arc shape also includes a form in which the arc shape has a pair of side walls and a connecting wall that connects the edges of the pair of side walls, and the side walls and connecting wall are curved so that they are continuously concave inward.
Furthermore, the V-shape also includes a mode in which a pair of substantially flat side walls are connected at their end edges so as to be concave inward.

The size of the bead portion 30 is not limited, but typically, in its cross-sectional shape, the ratio (t4/t3) of the thickness t3 of the structural portion 17 around the bead portion 30 to the depth t4 (maximum depth) of the bead portion 30 can be 0.1 to 50, preferably 0.5 to 25, and more preferably 1 to 10. However, the depth (height) of the bead portion 30 may be constant in the longitudinal direction of the bead portion 30, or may vary.

Furthermore, the bead portions 30 are typically elongated. Therefore, the bead portions 30 can function like beams in the structure 16, reinforcing a wide area, including areas other than the area where the bead portions 30 are formed. For this reason, the bead portions 30 may be provided only in a portion of the structure 17, but it is more preferable that they be provided so as to transversely or longitudinally extend across the structure 17. Examples of such bead portions include a bead portion 30 extending in the width direction of the structure 17, a bead portion 30 extending in the length direction of the structure 17, and a bead portion 30 extending along the outer edge of the structure 17. Furthermore, the bead portions 30 can be arranged so as not to intersect with each other (see FIG. 10( a)). However, from the viewpoint of torsional strength, etc., multiple bead portions 30 can also be arranged so as to intersect with each other (see FIG. 10( b)). For example, a pair of bead portions 30 can be arranged so as to intersect in an X-shape.
In addition, when viewed from above, the bead portion 30 may be formed in a straight line, a curved line, or a composite shape having both straight and curved lines. The number and arrangement of the bead portions are not particularly limited and may be selected appropriately depending on the application, etc.

The reinforcing band 50 includes a matrix resin 51 and continuous fibers 52, and the continuous fibers 52 are contained in the reinforcing band 50 in a state where they are bound by the matrix resin 51. Furthermore, it is preferable that the continuous fibers 52 are continuous fibers 52 that are substantially aligned in the same direction.
The reinforcing band 50 is integrally bonded to the bead portion 30 along the concave surface 30a and/or the convex surface 30b of the bead portion 30, and the continuous fibers 52 are laid along the extension direction of the bead portion 30. Specifically, for example, the reinforcing band 50 may be provided to cover the bottom of the concave surface 30a and/or the top of the convex surface 30b of the bead portion 30. Furthermore, for example, as illustrated in FIG. 3( a), the reinforcing band 50 may be provided to cover substantially the entire convex surface 30b of the bead portion 30. Furthermore, as illustrated in FIG. 3( b), the reinforcing band 50 may be provided to cover only the top surface of the convex surface 30b of the bead portion 30 and the outer surface of one of the side walls 41. Furthermore, as illustrated in FIG. 3( c), the reinforcing band 50 may be provided to cover the bottom surface of the concave surface 30a of the bead portion 30. Furthermore, as illustrated in FIG. 3( d), the reinforcing band 50 may be provided to cover substantially the entire concave surface 30a of the bead portion 30. Furthermore, as illustrated in FIG. 3( e ), a reinforcing band 50 may be provided that covers only the bottom surface of the concave surface 30 a of the bead portion 30 and the inner surface of one of the side walls 41 .
Furthermore, the structural portion 17 may be provided with the reinforcing band 50 so that the thickness thereof is the same as that of the periphery 17s of the structural portion 17 without the reinforcing band 50, but it is preferable to provide the reinforcing band 50 so that the thickness thereof is greater than that of the periphery 17s of the structural portion 17. In this embodiment, a more pronounced reinforcing effect can be obtained. Similarly, when comparing the thickness t1 of the bead portion 30 (i.e., the reinforcing portion) with the reinforcing band 50 with the thickness t2 of the bead portion 30 without the reinforcing band 50, the two may be formed to have the same thickness, but it is preferable to form the thickness t1 so that the thickness t1 is greater. In this embodiment, a more pronounced reinforcing effect can be obtained.

That is, the reinforcing band 50 is provided to lay the continuous fibers 52 along the extension direction of the bead portion 30. By laying the continuous fibers 52 along the extension direction of the bead portion 30, it is possible to obtain superior strength reinforcement compared to the case where only the bead portion 30 is provided.
As mentioned above, this reinforcement is particularly useful when the structural portion 17 (including the bead portion 30) is made of fiber-reinforced resin and the reinforcing fibers are discontinuous or woven. While discontinuous reinforcing fibers allow the structural portion 17 to be molded more easily using methods such as injection molding, if the force applied to the structural portion 17 is widely applied across the upper and lower ends, or across the left and right ends, the structural portion 17 alone cannot have reinforcing fibers extending along the applied force range. In other words, discontinuous fibers are short and oriented in various directions within the structural portion 17, and therefore cannot have the property of contributing strongly to a specific direction. The same is true when the reinforcing fibers are woven; because it is not possible to orient all of the reinforcing fibers in the required direction, some reinforcing fibers will not contribute to reinforcement. This tendency is more pronounced when the structural portion 17 is shell-shaped. In other words, when an external force is applied to the structure 16, if the structural part 17 is shell-shaped, the force applied over a wide area where the bead part 30 is not formed is more likely to be concentrated on the bead part 30, and a greater force may act on the bead part 30.

In contrast, if a bead portion 30 requiring reinforcement is provided and a reinforcing band 50 is provided with continuous fibers 52 laid along the extension direction of the bead portion 30, the entire amount of laid continuous fibers 52 can be used as a reinforcing element to resist the force applied to the bead portion 30. In other words, because the bead portion 30 is a reinforcing structure that is attached with a fixed installation direction, the reinforcement provided by the bead portion 30 is in the extension direction of the bead portion 30. Therefore, the reinforcement path is clear in the bead portion 30, and the reinforcing effect of the reinforcing band 50 can be obtained extremely significantly.

The reinforcing band 50 may comprise a matrix resin 51 and continuous fibers 52, but may also comprise other components. Specifically, it may comprise a base fabric 54, sewing thread, etc. (See FIGS. 1 and 2). That is, as mentioned above, it is easier to obtain the effect of paralleling the continuous fibers 52 when they are bundled together rather than when they are used individually. For this reason, it is preferable to use the continuous fibers 52 as bundled fiber bundles 53. When using fiber bundles 53, it is preferable to use a base material to fix the orientation direction of the fibers, and the base fabric 54 can be used as this base material.
The base fabric 54 can function to gather the plurality of fiber bundles 53 together for easy handling. The fiber bundles 53 may be fixed to the base fabric 54 in any manner, but can be fixed in particular by sewing. In this case, the fiber bundles 53 can be sewn and fixed to the base fabric 54 using sewing thread.
In this way, in a core material formed by sewing together fiber bundles 53 using sewing thread, it is easy to impregnate the core material with matrix resin 51, which is advantageous for compounding as fiber reinforced resin.

That is, for example, the reinforcing band 50 can include fiber bundles 53 made of continuous fibers 52, a base fabric 54 in which the fiber bundles 53 are arranged, and a matrix resin 51 impregnated and fixed into the fiber bundles 53 and the base fabric 54.
The fiber bundle 53 may or may not be twisted. The fiber bundle 53 may also include fibers (non-reinforcing fibers) other than the continuous fibers 52 (reinforcing fibers).
The fiber bundle 53 may be bundled in any manner. For example, the bundled state may be realized by simply pulling together a plurality of continuous fibers 52. Alternatively, the bundled state may be realized by binding a plurality of continuous fibers 52 together using a thread (bundling thread). Alternatively, the bundled state may be realized by binding the continuous fibers 52 together using other agents such as an adhesive, a pressure-sensitive adhesive, or a thermal adhesive.

The material of the continuous fibers 52 constituting the reinforcing band 50 is not limited, but the same material as the continuous fibers 52 used when the structural portion 17 is formed from fiber-reinforced resin can be used. Of the above, carbon fiber is particularly preferred. The type of carbon fiber is not limited, and examples include PAN (polyacrylonitrile)-based carbon fiber and pitch-based carbon fiber. These may be used alone or in combination of two or more types.
Carbon fibers can be used as filaments. However, when carbon fibers are used as fiber bundles 53 as described above, the number of continuous fibers 52 constituting one fiber bundle 53 is not particularly limited. This number can be, for example, 3,000 or more. When the number of continuous fibers 52 constituting one fiber bundle 53 is 3,000 or more, the fiber bundle 53 can exhibit excellent strength as a core material while being flexible. The number of continuous fibers 52 can be, for example, 3,000 to 100,000, 5,000 to 70,000, 7,000 to 50,000, or 10,000 to 30,000.
The continuous fibers 52 usually have a fiber length of 15 mm or more.

For the fiber bundle 53, a fiber bundle 53 (thick bundle) in which the number of continuous fibers 52 constituting each fiber can be increased can also be used. When using a thick bundle, the number of continuous fibers 52 can be, for example, 30,000 or more, even 40,000 or more, or even 60,000 or more. On the other hand, when using a thick bundle, the number of continuous fibers 52 can be, for example, 1,500,000 or less, or even 1,000,000 or less.

The fiber bundles 53 may be arranged on the base fabric 54 in one layer, or in two or more layers (see FIG. 2).
From the viewpoint of suppressing stress concentration, etc., it is possible to provide on both sides in the width direction of the reinforcing band 50 portions where the number of layers of the fiber bundles 53 is smaller or the spacing between adjacent fiber bundles 53 is larger than on the intermediate side sandwiched between the two sides. These portions can be gradually changing portions where the number of layers of the fiber bundles 53 gradually decreases or the spacing between adjacent fiber bundles 53 gradually increases from the intermediate side in the width direction of the reinforcing band 50 toward both sides.

There are no particular limitations on the material of the base fabric 54. Examples of materials that can be used for the base fabric 54 include a fiber assembly (woven fabric, knitted fabric, nonwoven fabric, etc.), a metal sheet (foil, plate, etc.), and a resin sheet (film, plate, etc.). These may be used alone or in combination of two or more types.
The method for fixing the fiber bundles 53 to the base fabric 54 is not particularly limited. Examples of such fixing methods include sewing, adhesive bonding, and fusion bonding. Among these fixing methods, sewing is preferred. An advantage of sewing is that the fiber bundles 53 can be fixed to the base fabric 54 without crimping. Another advantage of sewing is that the degree of restraint of the fiber bundles 53 can be freely controlled by the tension of the sewing thread (not shown). For example, when the fiber bundles 53 are sewn to the base fabric 54, the fiber bundles 53 can be firmly fixed to the base fabric 54 while ensuring the mobility of the fiber bundles 53 (mobility relative to the base fabric and/or mobility between the fiber bundles 53). Furthermore, ensuring the mobility of the fiber bundles 53 imparts flexibility to the reinforcing band 50.

When the fiber bundles 53 are sewn to the base fabric 54, it is preferable to use a fiber aggregate as the material for the base fabric 54. That is, when a fiber aggregate is used for the base fabric 54, it is easy to sew the fiber bundles 53 and it is also possible to impart flexibility to the reinforcing band 50. The fiber aggregate may be any of woven fabric, knitted fabric, and nonwoven fabric. Of these, woven fabric is preferable. Advantages of woven fabric include that it is easy to achieve a balance between flexibility and rigidity and that the binding force of the sewing thread used for sewing is high.
The weave of the woven fabric is not particularly limited, but is preferably a flat weave such as 1x1, 2x2, or 3x3. The flat weave is preferably a weave finer than 5x5, more preferably a weave of 4x4 or finer, even more preferably a weave of 3x3 or finer, and particularly preferably a weave of 2x2 or finer.
The constituent yarns of the fiber assembly are not particularly limited. The constituent yarns may be the same fibers as the continuous fibers 52 constituting the fiber bundles 53, or different fibers may be used. Specifically, the constituent yarns may be various resin fibers, plant fibers, etc. Specific examples of resins constituting the resin fibers include polyamides (aliphatic polyamides, aromatic polyamides, etc.), polyesters (polyesters having structural units derived from aromatic dicarboxylic acids, etc.), etc. Specific examples of plant fibers include cotton fibers, hemp fibers, etc. The fineness of the constituent yarns is not particularly limited. It is preferable that the fineness be smaller than that of the fiber bundles 53.

The reinforcing band 50 is formed by arranging fiber bundles 53 in parallel on one surface of the base fabric 54. The form of the reinforcing band 50 is not particularly limited. For example, this form may be a structure in which the fiber bundles 53 are arranged over the entire surface of the base fabric 54, or a structure in which the fiber bundles 53 are arranged only in necessary portions of one surface of the base fabric 54.
The reinforcing band 50 may be composed of only one fiber bundle 53, or may be composed of multiple fiber bundles 53. When the reinforcing band 50 is composed of only one fiber bundle 53, it can be realized by folding and arranging the single fiber bundle 53 so as to fill one surface of the base fabric 54. In this case, the folding shape of the fiber bundle 53 is not particularly limited. Examples of such folding shapes include an accordion-like shape and a spiral shape (circular spiral, polygonal spiral, etc.) in a plan view. Furthermore, when the reinforcing band 50 is composed of multiple fiber bundles 53, it can be realized by arranging the multiple fiber bundles 53 in a line so as to fill one surface of the base fabric 54. Furthermore, one layer of the reinforcing band 50 can be formed so as to fill one surface of the base fabric 54 by folding and arranging one fiber bundle 53 and arranging the other multiple fiber bundles 53 in a line.

Because the reinforcing band 50 is not formed by weaving or knitting the fiber bundles 53, the fiber bundles 53 can be arranged in a flat plane without crimping. In other words, the reinforcing band 50 suppresses the orientation of the fiber bundles 53 in the thickness direction, thereby increasing the flatness of the fiber bundles 53. As a result, the transmission of force via the orientation of the fiber bundles 53 in the thickness direction is suppressed, allowing for excellent shock absorption.

The reinforcing band 50 may be arranged, for example, so that the base fabric 54 faces the structural portion 17, or so that the fiber bundles 53 face the structural portion 17. The reinforcing band 50 may have only one layer, or may have multiple layers stacked together. Furthermore, when multiple reinforcing bands 50 are used, the fiber bundles 53 of each reinforcing band 50 may be arranged parallel to each other in areas where multiple bead portions 30 do not intersect, and may intersect in areas where multiple bead portions 30 intersect. This intersecting angle is preferably greater than 0 degrees and less than or equal to 90 degrees (0 degrees < θ ≦ 90 degrees).

When a reinforcing band 50 has multiple layers, it is preferable that the base fabrics 54 of the reinforcing bands 50 are stacked so that they face each other. This is because the propagation of force in the thickness direction of the reinforcing band 50 can be more accurately controlled. That is, the fiber bundles 53, which do not have crimps, can highly suppress the propagation of force in the thickness direction. On the other hand, in layers and between layers where the base fabrics 54 are arranged facing each other, the two layers of base fabrics 54 are arranged side by side, which has the effect of increasing the propagation of force in the layer direction between the layers of base fabrics 54. In other words, by making it easier to form cracks in the layer direction, impact forces applied in the thickness direction can be efficiently dispersed in the layer direction, thereby reducing the magnitude of the impact force in the thickness direction.
Furthermore, the reinforcing bands 50 are not limited to being configured so that the base fabrics 54 of each band are stacked facing each other, but can also be configured so that the fiber bundles 53 of each band are stacked facing each other, or so that the base fabric 54 of one reinforcing band 50 and the fiber bundles 53 of the other reinforcing band 50 are stacked facing each other.

The matrix resin 51 is a resin that serves as the base material of the reinforcing band 50. That is, the matrix resin 51 is a resin that is impregnated and fixed (cured if it is a curable resin, or solidified if it is a thermoplastic resin) so as to permeate the interior of the fiber bundles 53 and the base fabric 54. As a method for impregnating and fixing the matrix resin 51, various conventionally known methods can be used.
The matrix resin 51 constituting the reinforcing band 50 is similar to the resin that can constitute the structural portion 17 (the matrix resin when it contains reinforcing fibers).
When both the structural part 17 and the reinforcing band 50 are made of fiber-reinforced resin, the matrix resins used for them may be different, but are preferably the same, and more preferably the same resin. When the matrix resins are the same, the bonding strength at the interface between the structural part 17 and the reinforcing band 50 can be improved, and a stronger reinforced structure can be obtained.
The term "homogeneous" refers to cases where both matrix resins are polyolefins, polyamides, polyesters, or epoxy resins. That is, cases where the resin types are the same are included. On the other hand, cases where the resins are the same include cases where the specific resin itself is the same, such as when both polypropylenes are used or when both polyamide 6s are used.

The structure 16 can also be constructed by arranging a structural portion 17, which includes a bead portion 30 with a reinforcing band 50, facing a similar structural portion 48, which is also made of wire-reinforced resin, with a core layer 47 provided in the gap between the two. In this case, weight can be reduced by using a foamed resin for the core layer 47.

Furthermore, the reinforcing band 50 can have a transition region within the matrix resin 51 on the bonding surface side with the bead portion 30. By having a transition region, the bonding strength between the bead portion 30 and the reinforcing band 50 can be improved. Specifically, a transition region between the two constituent materials can be mentioned. That is, for example, if the structural portion 17 is made of a fiber-reinforced resin using discontinuous fibers, the region where the discontinuous fibers are contained at the interface of the reinforcing band 50 can be the transition region. Alternatively, the region where the two matrix resins are mixed can be the transition region.

The bead portion 30 may also have a fastening structure with another structure 18 (see FIG. 3 ). Examples of the other structure 18 include metal parts. The function, shape, size, etc. of the metal parts are not particularly important. Examples of the metal parts include metal fittings for connecting, fastening, welding, etc. the structural portion 17 to another member. Examples of such metal fittings include hinge fittings that allow rotation relative to another member, connecting fittings such as bracket fittings and joint fittings that are fixed to another member, stay fittings that are supported by another member, angle fittings that are fixed at a predetermined angle to another member, and fastening fittings that are fastened to another member.
Furthermore, the material constituting the metal parts is not limited, and examples thereof include iron, steel, aluminum, aluminum alloy, copper, and stainless steel.
Furthermore, examples of the joining method for the metal component to the structural part 17 include fastening using fasteners 64 such as screws and rivets, insert molding, bonding with an adhesive, laser welding, vibration welding, etc. Among these, fastening using fasteners 64 is preferable from the viewpoint of joining strength, etc.

The use of the present structure is not particularly limited. For example, the present structure can be used as an automobile part. Examples of automobile parts include automobile exterior materials, automobile interior materials, automobile structural materials, automobile shock absorbing materials, and engine room parts.
Specific examples include bumpers, spoilers, cowlings, front grilles, garnishes, bonnets, trunk lids, cowl louvers, fender panels, rocker moldings, door panels, roof panels, instrument panels, center clusters, door trims, quarter trims, roof linings, pillar garnishes, deck trims, tonneau boards, package trays, dashboards, console boxes, kicking plates, switch bases, seat backboards, seat frames, armrests, sun visors, intake manifolds, engine head covers, engine under covers, oil filter housings, housings for automotive electronic components (ECUs, TV monitors, etc.), energy absorbers such as air filter boxes and rush boxes, and body shell components such as front end modules.

In addition to automotive parts, examples of the structure include interior, exterior, and structural materials for buildings and furniture. Examples include door covering materials, door structural materials, covering materials and structural materials for various types of furniture (desks, chairs, shelves, chests, etc.), as well as modular baths and septic tanks. Other examples include packaging, containers (trays, etc.), protective materials, and partition members. Also included are molded articles such as housings and structures for home appliances (flat-screen TVs, refrigerators, washing machines, vacuum cleaners, mobile phones, portable game consoles, laptop computers, etc.).

[2] Method of Using the Structure In the structure 16 described above, the recesses of the bead portion 30 can be used as a space for laying long objects. Examples of such long objects include functional parts such as harnesses (electrical wiring, etc.) and tubes (pump tubes, etc.). These may be used alone or in combination of two or more types.
Furthermore, in the structure 16 described above, the grooves of the bead portion 30 can be used as flow paths for fluids. Examples of such fluids include gases and liquids. More specifically, examples include gases such as cold air and warm air. In other words, they can be used for ventilation. Examples of liquids include refrigerants.

<Vehicle seats>
The vehicle seat according to this embodiment includes a seatback frame configured with the structure according to the above embodiment. This seatback frame can include, for example, a seatback shell configured with the structural portion and an upper arm configured with the metal part.

Note that the reference symbols for each component described in the above embodiment indicate their corresponding relationship to the specific components described in the following examples.

The present invention will be specifically described below by way of examples with reference to the drawings.
In this embodiment, a seat back frame of a vehicle seat is exemplified as the "structure" according to the present invention (see FIG. 5).

As shown in FIG. 9 , the vehicle seat 1 according to this embodiment includes a seat cushion 2, which serves as a seating area for the seated occupant, and a seat back 3, which serves as a backrest for the seated occupant. The seat cushion 2 includes a seat cushion frame 5, which forms the framework of the seat cushion. A cushion pad 6 and a leather cover 7 are attached to the seat cushion frame 5. The seat cushion frame 5 also includes a pair of left and right side frames 11, a front pipe 12 connecting the front ends of the side frames 11, and a rear pipe 13 connecting the rear ends of the side frames. Each side frame 11 is provided with a lower arm portion 14, which is used to connect the cushion frame 5 to a seat back frame 16 (described below). The lower arm portion 14 is formed by projecting upward in a semicircular disk shape from the upper edge of the rear end of the side frame 11.

The seatback 3 includes a seatback frame 16 that forms the framework. The seatback frame 16 includes a seatback shell 17 (exemplified as a "structural part" according to the present invention) and a pair of left and right upper arms 18 (exemplified as "metal parts" according to the present invention) (see FIG. 5). A back pad 21 and a leather cover 22 are attached to the seatback shell 17 (see FIG. 7). The seatback shell 17 is formed into a concave, three-dimensional shape that conforms to the outer shape of the rear of the occupant's upper body to enhance the sense of support when leaning back. The upper arms 18 are provided at both left and right ends of the seatback shell 17 in the width direction, protruding downward from the lower end of the seatback shell 17. The upper arms 18 are metal fittings (e.g., iron fittings) used to connect the seat cushion frame 5 and the seatback frame 16, and are fastened to the seatback shell 17.

A recliner mechanism 24 (gear mechanism) is mounted between the upper arm 18 and the lower arm portion 14, rotatably connecting the seatback frame 16 to the seat cushion frame 5. When this recliner mechanism 24 is operated by a reclining motor 25, the seatback frame 16 is rotated relative to the seat cushion frame 5, and the backrest angle can be adjusted to any angle. Furthermore, the left and right recliner mechanisms 24 are connected by a shaft 15 (see Figure 6).

As shown in Figures 5 to 7, the seatback shell 17 has a three-dimensional shell shape with a concave surface facing the front side. The back pad 21 is disposed on the front side of the seatback shell 17 (see Figure 7). The seatback shell 17 also has holes 63a and 64a through which fasteners 63 and 64 (described later) are inserted (see Figure 6). The seatback shell 17 is made of a fiber-reinforced resin (e.g., epoxy resin) containing dispersed discontinuous fibers (e.g., carbon fibers) and/or a fiber-reinforced resin (e.g., epoxy resin) containing a woven fabric made of continuous fibers (e.g., carbon fibers). When the vehicle seat 1 is installed in the vehicle, the front side of the seatback shell 17 typically faces the front of the vehicle, and the back side of the seatback shell 17 typically faces the rear of the vehicle.
5 indicates a hole that penetrates the front and back of the seatback shell 17. Furthermore, the reference numeral 29 in FIG.

The seat back shell 17 has a plurality of bead portions 30A, 30B, 30C, and 30D (see FIG. 6). Each of the bead portions 30A to 30D has a pair of opposing side walls 41 and a connecting wall 42 connecting the tips of the pair of side walls 41.
The dashed arrows in FIG. 6 indicate the extension directions of the bead portions 30A to 30D.

The bead portion 30A (also referred to as the "wide bead") is arranged to extend in the width direction A of the seatback shell 17. More specifically, the bead portion 30A is arranged to connect the portions of the seatback shell 17 that support the shoulders and back of the seat occupant. The bead portion 30B (also referred to as the "main bead") is arranged to extend in the length direction B (up-down direction) of the seatback shell 17, intersecting in an X-shape. More specifically, the bead portion 30B is arranged to connect the portions of the seatback shell 17 that support the waist, back, and head of the seat occupant. The bead portion 30C (also referred to as the "side bead") is arranged to extend along the left and right edges of the seatback shell 17. The bead portion 30D (also referred to as the "connecting bead") is arranged to extend along the lower edge of the seatback shell 17. More specifically, the bead portion 30D is positioned so as to connect the left and right hollow cross-sectional portions 70, which will be described later.

The bead portions 30A, 30B, and 30D are formed so as to form concave ridges on the front side 17a of the seatback shell 17 and convex ridges on the back side 17b (see Figure 1). A pair of side walls 41 of each bead portion 30A, 30B, and 30D is raised from the back side of the surface portion of the seatback shell 17 that supports the backpack 22. The concave surfaces 30a of the bead portions 30A, 30B, and 30D form hollow portions 40. Furthermore, the height of the convex ridges of the bead portion 30D is higher than the height of the convex ridges of the bead portion 30B (see Figure 6). In other words, the bead portion 30D protrudes farther toward the back side of the seatback shell 17 than the bead portion 30B. Therefore, the intersection of the bead portions 30B and 30D forms a step portion 43.

The bead portion 30C is formed as a concave rib on the back side 17b of the seatback shell 17 and as a convex rib on the front side 17a. This bead portion 30C is located closer to the front side of the seatback shell 17 than the other bead portions 30A, 30B, and 30D. The inner side wall 41 of the bead portion 30C is continuous with the side edge of the seatback shell 17. The outer side wall 41 of the bead portion 30C is formed with an extension portion 44 that extends toward the back side of the lower part of the seatback shell 17.

Each of the bead portions 30A-30D is integrally provided with a reinforcing band 50 containing continuous fibers (e.g., carbon fibers) 52 bound with a matrix resin 51 (e.g., epoxy resin) and laid along the extension direction of the bead portions 30A-30D (see Figure 1). This reinforcing band 50 is arranged along the connecting walls 42 of the bead portions 30A, 30B, and 30D. Furthermore, the reinforcing band 50 is arranged along the extension portion 44 together with the outer side wall 41 and connecting wall 42 of the bead portion 30C.

As shown in FIG. 1, the reinforcing band 50 comprises fiber bundles 53 formed by bundling continuous fibers 52, a base fabric (e.g., woven fabric) 54 in which the fiber bundles 53 are arranged, and a matrix resin 51 impregnated and fixed into the fiber bundles 53 and base fabric 54. The fiber bundles 53 are sewn onto the base fabric 54 in a single layer and arranged along the extension direction of the bead portions 30A-30D. The fiber bundles 53 are also arranged to form holes 63a, 64a (see FIG. 6) in the seatback shell 17 (portion including the reinforcing band 50). Furthermore, in the seatback shell 17, the thickness t1 of the reinforcing portion including the reinforcing band 50 is greater than the thickness t3 of the periphery 17s of the reinforcing portion without the reinforcing band 50.

The fiber bundles 53 may be arranged in two or more layers on the base fabric 54 by sewing (see Figure 2). In this case, from the perspective of suppressing stress concentration, it is preferable that regions 56 be provided on both sides of the reinforcing band 50 in the width direction, where the number of layers of fiber bundles 53 is fewer than in the middle region sandwiched between the two sides.

As shown in Figures 5 to 7, the upper arms 18 are disposed on both the left and right sides of the lower portion of the seatback shell 17 in the width direction A. The upper arms 18 have a first surface 61 and a second surface 62 that intersect with each other. The first surface 61 has a hole 63b through which a fastener 63 is inserted, and the second surface 62 has a hole 64b through which a fastener 64 is inserted (see Figure 6).

As shown in FIG. 8, the first surface portion 61 is fastened with fasteners (specifically, screws and nuts) 63 to an extension portion 61 extending from the outer side wall 41 of the bead portion 30C. This first surface portion 61 is provided with an interlocking portion (specifically, a hole) 66 onto which an interlocking portion (specifically, a hook portion) 22a provided on the upholstery cover 22 that covers the surface of the seatback shell 17 is hooked. This interlocking portion 66 is located at a bent portion 67 formed by hemming on the outer edge of the upper arm 18. This bent portion 67 is thicker than the portion of the first surface portion 61 that is connected to it.

In this embodiment, the seatback shell 17 has bead portions 30B and 30D, and the upper arm 18 is fastened to the bead portions 30B and 30D. As a result, the bead portions 30B and 30D reinforce the fastening portion between the seatback shell 17 and the upper arm 18, further improving strength and rigidity.
In particular, in this embodiment, the upper arm 18 has a step portion 69 that is applied to the intersection (step portion 43) of the bead portions 30B, 30D whose ridge heights are different, and is fastened to each of the bead portions 30B, 30D on both sides across the step portion 69. As a result, the step portion 69 further reinforces the area between the fastening portion of the seatback shell 17 and the upper arm 18.

In addition, in this embodiment, the bead portions 30B, 30D are integrally provided with reinforcing bands 50 containing continuous fibers 52 bound by matrix resin 51 and laid along the extension direction of the bead portions 30B, 30D. This provides stronger reinforcement to the fastening portion between the seatback shell 17 and the upper arm 18 by the reinforcing bands 50.

In addition, in this embodiment, the upper arms 18 are disposed on both the left and right sides of the seatback shell 17 in the width direction A, and are fastened to bead portions 30D that connect the hollow cross-sectional portions 70 formed on both the left and right sides of the seatback shell 17 in the width direction A. This provides stronger reinforcement between the fastening portions of the seatback shell 17 and the upper arms 18 by the bead portions 30D.

Furthermore, in this embodiment, the upper arm 18 is provided with a latching portion 66 onto which the latching portion 22a provided on the skin cover 22 is latched. This allows the upper arm 18 to be used to form a latching structure for the skin cover 22.

Furthermore, in this embodiment, the seatback shell 18 is made of fiber-reinforced resin, which allows for further weight reduction without sacrificing strength and rigidity.

The present invention is not limited to the above-described embodiment, but may be modified in various ways within the scope of the present invention depending on the purpose and application.
Figure 10(b) is an explanatory diagram showing a simplified plan view of the bead portions 30A, 30B, and 30D shown in Figure 6, and shows a state in which two bead portions 30B intersect in the gaps between two bead portions 30A. In contrast, Figure 10(a) shows a modified example, and is an explanatory diagram showing a simplified plan view of the bead portions 30A, 30B, and 30D, and shows a state in which two bead portions 30B intersect with two bead portions 30A without intersecting each other.

The foregoing examples are for illustrative purposes only and are not to be construed as limiting the invention. While the invention has been described with reference to exemplary embodiments, the words used in describing and illustrating the invention are understood to be descriptive and exemplary, rather than limiting. As detailed herein, changes may be made within the purview of the appended claims without departing from the scope or spirit of the invention in its form. While the description of the invention has referred to specific structures, materials, and examples, it is not intended that the invention be limited to the disclosures therein; rather, the invention is intended to cover all functionally equivalent structures, methods, and uses within the scope of the appended claims.

The present invention is not limited to the embodiments detailed above, and various modifications and variations are possible within the scope of the claims of the present invention.

This invention has wide application as a technology related to structures in which metal parts are joined to structural members. It is particularly suitable for use as a seatback frame for vehicle seats.

16: Structure (seat back frame),
17; structural part (seat back shell), 17a; one side (surface side), 17b; opposite side (back side), 17s; periphery,
30; bead portion, 30A, 30B, 30C, 30D; bead portion,
30a; concave surface; 30b; convex surface;
41: side wall, 42: connecting wall,
50: Reinforcing band, 51: Matrix resin, 52: Continuous fiber.

Claims (9)

A structural portion integrally formed with one or more bead portions and a reinforcing band provided along the bead portion,
The bead portion is shaped to have a concave rib on one surface side of the structural portion and a convex rib on the opposite surface side,
the reinforcing band includes continuous fibers bound with a matrix resin and is integrally joined to the bead portion along the concave and/or convex surfaces of the bead portion;
The continuous fibers are laid along the extension direction of the bead portion,
the bead portion includes a pair of side walls and a connecting wall connecting end edges of the side walls,
A structure characterized in that the reinforcing band is provided only on the connecting wall of the ridge. The structure described in claim 1, wherein the reinforcing portion including the reinforcing band is thicker than the surrounding area of the reinforcing portion without the reinforcing band. The structure described in claim 1 or 2, wherein the structural portion is made of a fiber-reinforced resin containing dispersed discontinuous fibers and/or a fiber-reinforced resin containing a woven fabric made of continuous fibers. 4. The structure according to claim 1, wherein the reinforcing band comprises a fiber bundle formed by bundling the continuous fibers, a base fabric to which the fiber bundle is sewn, and the matrix resin impregnated and fixed into the fiber bundle and the base fabric. 5. The structure according to claim 1, wherein the reinforcing band has a transition region in the matrix resin on a surface thereof that is bonded to the bead portion. 6. The structure according to claim 1, wherein the cross-sectional shape of the bead portion is U-shaped, U-shaped, and/or cup-shaped. The structure according to claim 1 , wherein the bead portion has a fastening structure for fastening to another structure. 8. A method for using the structure according to claim 1, wherein the recessed portion of the bead portion is used as a laying space for laying an elongated object. 8. A method for using the structure according to claim 1, wherein the grooves of the bead portion are used as flow paths for fluids.