WO2014030633A1

WO2014030633A1 - Three-dimensional fiber-reinforced composite

Info

Publication number: WO2014030633A1
Application number: PCT/JP2013/072159
Authority: WO
Inventors: 良平辻; 雅彦安江; 都築　誠; 神谷　隆太; 俊久野
Original assignee: 株式会社豊田自動織機
Priority date: 2012-08-21
Filing date: 2013-08-20
Publication date: 2014-02-27

Abstract

This three-dimensional fiber-reinforced composite is provided with: a laminate having a plurality of fiber-bundle layers laminated in a laminating direction, the fiber-bundle layers including first and second outermost layer; a matrix resin; a retaining yarn; and a binding yarn. The binding yarn has a folded-back section folded back so as to pass through the outside of the retaining yarn in the laminating direction, a first traverse yarn section and a second traverse yarn section that are continuous with the folded-back section and extend in the laminating direction through inside the laminate, and a surface-layer yarn section that extends in a direction substantially orthogonal to the retaining yarn along the surface of the second outermost layer on the surface of the second outermost layer. The surface-layer yarn section has bifurcated sections extending in opposite directions from the first traverse yarn section and the second traverse yarn section on the surface of the second outermost layer. The laminate includes a holding layer positioned close to the bifurcated sections in the laminating direction.

Description

3D fiber reinforced composite

The present disclosure relates to a three-dimensional fiber reinforced composite material formed by impregnating a matrix resin in a laminate bonded in a laminating direction by a binding yarn.

A three-dimensional fiber reinforced composite material is used as a lightweight and high-strength material. The three-dimensional fiber reinforced composite material has a laminate formed by binding a plurality of fiber bundle layers with binding yarns in a matrix resin. For this reason, the three-dimensional fiber reinforced composite material is preferable as a structural component because it is superior in mechanical properties (mechanical properties) compared to a material containing only a matrix resin. In addition, the three-dimensional fiber reinforced composite material has improved strength in the stacking direction due to the binding yarn as compared with the two-dimensional fiber reinforced composite material.

Examples of this type of three-dimensional fiber reinforced composite material include those disclosed in Patent Document 1. As shown in FIG. 5, the three-dimensional fiber reinforced composite material 80 of Patent Document 1 has a flat three-dimensional woven fabric 86, and the three-dimensional woven fabric 86 includes a plurality of warp yarns 81 and a plurality of weft yarns 82. The in-plane direction yarn 83, the plurality of out-of-plane direction yarns 84 orthogonal to the reference plane of the in-plane direction yarn 83, and the ear yarn 85 that fixes the out-of-plane direction yarn 84. The three-dimensional woven fabric 86 is impregnated with resin, and the resin is cured to form a three-dimensional fiber reinforced composite material 80.

JP 2007-152672 A

By the way, in the three-dimensional fiber reinforced composite material 80, when the out-of-plane direction yarn 84 is inserted into the three-dimensional woven fabric 86 and the sewing proceeds, the out-of-plane direction yarn 84 is pulled in a direction along the surface of the three-dimensional woven fabric 86. It is done. For this reason, a large gap is formed by pulling in a portion where the out-of-plane direction yarn 84 extends in the opposite direction (a portion that is bifurcated). When the three-dimensional woven fabric 86 is impregnated with resin, the resin remains in the gap and a resin reservoir 87 is formed. This resin reservoir 87 is a portion where the mechanical strength of the three-dimensional fiber reinforced composite material 80 is low because it does not contain fibers. Therefore, it is desired to make the resin reservoir 87 small.

An object of the present disclosure is to provide a three-dimensional fiber reinforced composite material that can reduce a resin reservoir at a bifurcated portion.

A three-dimensional fiber reinforced composite material for achieving the above object is a laminate having a plurality of fiber bundle layers laminated in a lamination direction, and the fiber bundle layer includes first and second outermost layers. The laminated body, a matrix resin impregnated in the laminated body, a retaining thread extending along the surface of the first outermost layer, and a binding thread that binds the fiber bundle layer in the laminating direction. The binding yarn is a folded portion that is folded back so as to pass outside of the retaining yarn in the stacking direction, and a first transverse yarn portion and a second transverse yarn that are continuous with the folded portion and extend in the stacking direction in the stacked body. And a surface layer yarn portion extending in a direction substantially orthogonal to the retaining yarn along the surface of the second outermost layer on the surface of the second outermost layer. The surface layer yarn portion has a bifurcated portion extending in a direction opposite to the first transverse yarn portion and the second transverse yarn portion on the surface of the second outermost layer. The laminate includes a holding layer positioned near the bifurcated portion in the lamination direction.

In this configuration, when the binding thread is sewed into the laminate, the binding thread is pulled in a direction along the surface of the laminate, but the shape of the bifurcated portion is retained by the holding layer and the bifurcated portion is prevented from spreading. can do. Therefore, even if the resin resin reservoir is formed by impregnating the bifurcated portion with the matrix resin, the size of the resin reservoir can be reduced as compared with the case where the holding layer is not provided.

Further, the holding layer may be the second outermost layer.

According to this, the holding layer can be brought closest to the bifurcated portion, and the spread of the bifurcated portion when the binding yarn is pulled can be efficiently suppressed.

The holding layer is a plurality of first yarns that are fiber bundles and arranged in parallel to each other, and a plurality of first yarns that are fiber bundles and arranged in parallel to each other, and extend in a direction intersecting with the first yarns. And a second woven fabric provided with the second yarn.

According to this, since the first yarn and the second yarn of the holding layer are interlaced with each other, the interval between the first and second yarns is prevented from spreading. Further, even if the binding yarn is pulled and the holding layer is pulled, a frictional resistance is generated at the intersection of the first yarn and the second yarn in the holding layer, and the holding layer is difficult to spread due to this frictional resistance. As a result, even if the binding yarn is pulled, it is possible to prevent the bifurcated portion from spreading by the holding layer.

In addition, a plurality of retaining yarns are arranged to extend in parallel with each other at intervals, and the pair of the folded portion and the first and second transverse yarn portions continuous thereto are each provided in the plurality of retaining yarns. The first yarn extends in the same direction as the retaining yarn and is arranged at intervals in a direction orthogonal to the retaining yarn, and in a direction along the surface of the laminate. In the direction orthogonal to the retaining yarn, the pair of the first and second transverse yarn portions may be arranged at an interval equal to or greater than the arrangement interval of the first yarn.

According to this, as the pitch between the first yarns or the second yarns in the holding layer is narrower, the intersection between the first yarn and the second yarn existing per unit area increases, and frictional resistance is generated. More places. Therefore, even when the binding yarn is pulled, the shape of the bifurcated portion can be retained by the retaining layer, and the bifurcated portion can be prevented from spreading.

Further, the fiber bundle layer, the retaining yarn, the binding yarn, and the holding layer may be formed of carbon fibers.

According to this, the laminate is formed of only a carbon material. Therefore, the strength reduction of the three-dimensional fiber reinforced composite material due to the mixture of materials other than the carbon material can be eliminated.

The holding layer may be a layer formed of satin weave or twilled fibers, or a layer including a nonwoven fabric or a resin film.

The disassembled perspective view which shows the laminated body of the three-dimensional fiber reinforced composite material of embodiment. The perspective view which shows the three-dimensional fiber reinforced composite material of embodiment. Sectional drawing which shows the three-dimensional fiber reinforced composite material of FIG. Sectional drawing which shows the state before compressing a laminated body. Sectional drawing which shows the state which compressed the laminated body. The figure which shows background art.

Hereinafter, an embodiment of a three-dimensional fiber reinforced composite material will be described with reference to FIGS.

As shown in FIGS. 2 and 3, the three-dimensional fiber reinforced composite material 10 includes a laminate 20 and a matrix resin 30. The laminate 20 is formed by laminating a plurality of fiber bundle layers in the form of a sheet, that is, the first to fourth reinforcing fiber bundle layers 11 to 14 and the holding layer 15, and the first to fourth reinforcing fiber bundles. The layers 11 to 14 and the holding layer 15 are formed by bonding using the bonding yarn 21 and the retaining yarn 22. The matrix resin 30 is formed by impregnating the laminate 20 with a resin.

As shown in FIG. 1, the first to fourth reinforcing fiber bundle layers 11 to 14 include a plurality of first to fourth reinforcing fiber bundles 11a to 14a extending in the same direction in each layer. The “reinforcing fiber bundle” means a matrix of the three-dimensional fiber reinforced composite material 10 when the first to fourth reinforcing fiber bundle layers 11 to 14 are used as the fiber base material of the three-dimensional fiber reinforced composite material 10. The fiber bundle which plays the role which reinforces resin 30 is meant. In this embodiment, carbon fibers are used as the reinforcing fibers. In the following description, among the directions along the surface of the three-dimensional fiber reinforced composite material 10, a direction along one side of the three-dimensional fiber reinforced composite material 10 is defined as an X direction, and a direction orthogonal to the X direction is defined as a Y direction. Further, in the three-dimensional fiber reinforced composite material 10, the direction in which the first to fourth reinforcing fiber bundle layers 11 to 14 are stacked perpendicular to the X direction and the Y direction is defined as a stacking direction.

As shown in FIG. 1, the first reinforcing fiber bundle layer 11 is formed of first reinforcing fiber bundles 11 a that are arranged in parallel to each other and extend straight. The first reinforcing fiber bundle 11a has a flat cross section. The first reinforcing fiber bundle 11 a extends at an angle of 90 degrees with respect to the X direction of the three-dimensional fiber reinforced composite material 10. The plurality of first reinforcing fiber bundles 11a are connected by an auxiliary yarn 11b extending in the arrangement direction of the first reinforcing fiber bundles 11a.

The second reinforcing fiber bundle layer 12 is formed of second reinforcing fiber bundles 12a that are arranged in parallel to each other and extend straight. The second reinforcing fiber bundle 12a has a flat cross section. The second reinforcing fiber bundle 12 a extends in the X direction of the three-dimensional fiber reinforced composite material 10. The plurality of second reinforcing fiber bundles 12a are connected by auxiliary yarns 12b extending in the arrangement direction of the second reinforcing fiber bundles 12a.

The third reinforcing fiber bundle layer 13 is formed of third reinforcing fiber bundles 13a that are arranged in parallel to each other and extend straight. The third reinforcing fiber bundle 13a has a flat cross section. The third reinforcing fiber bundle 13 a extends at an angle of +45 degrees with respect to the X direction of the three-dimensional fiber reinforced composite material 10. The plurality of third reinforcing fiber bundles 13a are connected by an auxiliary yarn 13b extending in the arrangement direction of the third reinforcing fiber bundles 13a.

The fourth reinforcing fiber bundle layer 14 is formed of fourth reinforcing fiber bundles 14a that are arranged in parallel to each other and extend straight. The fourth reinforcing fiber bundle 14a has a flat cross section. The fourth reinforcing fiber bundle 14 a extends at an angle of −45 degrees with respect to the X direction of the three-dimensional fiber reinforced composite material 10. The plurality of fourth reinforcing fiber bundles 14a are connected by auxiliary yarns 14b extending in the arrangement direction of the fourth reinforcing fiber bundles 14a.

The holding layer 15 is a plain weave in which a plurality of warps 15a (first yarn) and a plurality of wefts 15b (second yarn) are alternately woven one by one. The plurality of warps 15a are each made of a fiber bundle, arranged in parallel to each other, and extend in the Y direction. Each of the plurality of wefts 15b is also made of a fiber bundle, arranged in parallel to each other, and extends in a direction (X direction) intersecting (orthogonal) with the warp 15a. The fiber bundle of the warp yarn 15a and the weft yarn 15b is formed of carbon fiber. As shown in FIG. 3, an interval between adjacent warps 15a is defined as a pitch P1. In the present specification, “interval between adjacent warps 15a (arrangement interval or pitch P1)” means an interval between adjacent warps 15a on one side of one weft 15b. This is the interval between the warp yarns 15a arranged every other.

As shown in FIGS. 2 and 3, the laminate 20 is formed by laminating the laminated first to fourth reinforcing fiber bundle layers 11 to 14 and the holding layer 15 with a plurality of binding yarns 21 in the laminating direction. ing. On the surface of the fourth reinforcing fiber bundle layer 14 that is the first outermost layer of the two outermost layers in the stacking direction of the stacked body 20, a plurality of first retaining threads 22 are attached to each other along the Y direction. They extend in parallel and are spaced apart in the X direction.

The binding yarn 21 and the retaining yarn 22 are made of carbon fiber. Each of the plurality of binding yarns 21 is inserted into the laminated body 20 from the surface of the holding layer 15 that is the second outermost layer, penetrates the laminated body 20 in the laminating direction, and then the surface of the fourth reinforcing fiber bundle layer 14 And is looped back through the outside in the stacking direction of the retaining thread 22. Further, the binding yarn 21 is inserted into the laminated body 20 from the surface of the fourth reinforcing fiber bundle layer 14, penetrates the laminated body 20 in the laminating direction, and is drawn out to the surface of the holding layer 15. The binding yarn 21 drawn to the surface of the holding layer 15 extends along the surface of the holding layer 15 in a direction opposite to the binding yarn 21 that has already been drawn to the holding layer 15, and then the laminate again. 20 is inserted. Therefore, the single binding yarn 21 is repeatedly folded back on the surface of the fourth reinforcing fiber bundle layer 14 and repeatedly inserted and drawn out on the surface of the holding layer 15. Therefore, one binding thread 21 joins the laminate 20 at a plurality of locations.

As shown in FIG. 4, in a state where the binding yarn 21 is passed through the laminated body 20, the binding yarn 21 includes a folded portion 21 a that is a portion that is folded outside the retaining yarn 22 in the stacking direction. The binding yarn 21 includes a transverse portion that is a portion that is continuous with the folded portion 21a and extends in the stacking direction in the stacked body 20. The crossing portion includes a pair of a first crossing yarn portion 21 b and a second crossing yarn portion 21 c that extend in parallel with each other from both sides of the retaining yarn 22. Further, the binding yarn 21 includes a surface layer yarn portion 21 d that is a portion extending in a direction orthogonal to the retaining yarn 22 on the surface of the holding layer 15. A portion of the surface layer yarn portion 21d extending in the opposite direction from the first and second

transverse yarn portions

21b and 21c on the surface of the holding layer 15 forms a bifurcated portion 21e. The folded portion 21a, the first transverse yarn portion 21b, the second transverse yarn portion 21c, and the bifurcated portion 21e are arranged so as to overlap each retaining yarn 22 when viewed from the stacking direction, and X similarly to the retaining yarn 22 They are arranged at intervals along the direction.

As shown in FIG. 3, in the laminated body 20, an interval between adjacent transverse portions (that is, a pair of adjacent first and second

transverse yarn portions

21 b and 21 c), in other words, a center of adjacent bifurcated portions 21 e. The pitch P2, which is the distance between the two, is constant. The pitch P2 is wider than the pitch P1 between the warps 15a. For this reason, at least one warp 15a exists between the adjacent bifurcated portions 21e.

As shown in FIG. 4, the thickness in the stacking direction of the laminate 20 at the stage where the laminate 20 is formed (before the matrix resin 30 is impregnated) is defined as t. A position where the binding yarn 21 starts to bend from the surface yarn portion 21d toward the holding layer 15 is defined as a start end E. Further, a position where the binding yarn 21 has been bent from the transverse portion to the surface layer yarn portion 21d on the surface of the holding layer 15 is defined as a termination F. The length from the start end E of the binding yarn 21 to the outermost end G of the folded portion 21a and the length from the outermost end G to the end F of the folded portion 21a are defined as L. Further, the radius of the portion extending in the arc shape at the folded portion 21a is R1, and the radius of the portion extending in the arc shape from the start end E and the end F to the surface of the holding layer 15 is R2. In this case, the length 2L from the start end E to the end F of the binding yarn 21 is expressed by the following equation (1).

2L = 2t + 2πR1 / 2 + 2πR2 / 2-2R2 Formula (1)
Since the portions extending in an arc shape are portions of the same binding yarn 21, they are bent and deformed with substantially the same curvature. Therefore, approximately R1 = R2 = R. In this case, the formula (1) is 2L = 2t + 2R (π−1)
Is converted. Since π−1 is approximately 2.14, the equation (2) is obtained.

L = t + 2.14R ... Formula (2)
Therefore, by making the length L longer than the total of the thickness t of the laminate 20 and the length of the arcuately extending portion of the folded portion 21a and the bifurcated portion 21e multiplied by 2.14, The laminate 20 can be passed through the laminate 20 with a slack.

Next, an example of a method for manufacturing the three-dimensional fiber reinforced composite material 10 will be described.

First, the laminate 20 is manufactured. On the holding layer 15, the first reinforcing fiber bundle layer 11, the second reinforcing fiber bundle layer 12, the third reinforcing fiber bundle layer 13, and the fourth reinforcing fiber bundle layer 14 are laminated. A retaining thread 22 is disposed on the surface of the fourth reinforcing fiber bundle layer 14. Then, the binding yarn 21 is sewn in the X direction while passing in a direction orthogonal to each layer, and the layers 20 are joined while being folded back outside in the stacking direction of the retaining yarn 22 to manufacture the laminate 20.

As shown in FIG. 4, the stacked body 20 at the stage where the stacked body 20 is formed has a thickness t in the stacking direction. Further, the length L of the binding yarn 21 in the stacking direction is larger than the value obtained by adding 2.14R to the thickness t of the stacked body 20. For this reason, the folding | returning part 21a is in the loose state. Then, the laminate 20 is accommodated in a molding die used in a resin transfer molding (RTM) method, and a thermosetting resin is injected into the molding die while the laminate 20 is compressed in the laminating direction. The reinforcing fiber bundle layers 11 to 14, the holding layer 15, the binding yarn 21, and the retaining yarn 22 of the body 20 are impregnated. Thereafter, the thermosetting resin is cured by heating to form the matrix resin 30. Then, the matrix resin 30 is cured around each of the reinforcing fiber bundle layers 11 to 14, the holding layer 15, the binding yarn 21, and the retaining yarn 22, and the three-dimensional fiber reinforced composite material 10 is formed.

As shown in FIG. 5, the thickness t <b> 1 in the stacking direction of the laminate 20 in the three-dimensional fiber reinforced composite material 10 is thinner than the thickness t of the laminate 20 before forming the matrix resin 30. In addition, when the laminated body 20 is compressed during the production of the three-dimensional fiber reinforced composite material 10, the folded portion 21a of the binding yarn 21 is crushed and spread in the X direction. Similarly, the bifurcated portion 21e is also crushed, and the gap (dent) formed by the bifurcated portion 21e is narrower than before compression.

Next, the action of the three-dimensional fiber reinforced composite material 10 will be described.

In the laminate 20, the outermost layer facing the bifurcated portion 21e is a holding layer 15 that is a plain weave. Furthermore, the pitch P <b> 2 between the adjacent transverse portions is wider than the pitch P <b> 1 between the warps 15 a in the holding layer 15. For this reason, when the binding thread 21 is sewn to the laminated body 20, even if the binding thread 21 is pulled in a direction along the surface of the laminated body 20, due to the frictional resistance between the warp 15a and the weft 15b in the holding layer 15, The bifurcated portion 21e is prevented from spreading.

According to the above embodiment, the following effects can be obtained.

(1) In the laminate 20 bonded in the stacking direction by the bonding yarn 21, the holding layer 15 is provided near the bifurcated portion 21e of the bonding yarn 21, and the holding layer 15 is also provided with the first to fourth reinforcing fibers by the bonding yarn 21. Bonded to bundle layers 11-14. The bifurcated portion 21 e of the binding yarn 21 is positioned near the holding layer 15 and is held by the holding layer 15. The holding layer 15 is formed so as to be able to hold its own shape. Therefore, when the binding thread 21 is sewn forward, even if the binding thread 21 is pulled in a direction along the surface of the laminate 20, the shape of the bifurcated portion 21e is maintained by maintaining the shape of the holding layer 15. The bifurcated portion 21e is prevented from spreading. As a result, even if the bifurcated portion 21e is impregnated with the matrix resin 30 to form a resin reservoir, the size of the resin reservoir is smaller than when the holding layer 15 is not provided, and the fiber volume of the three-dimensional fiber reinforced composite material 10 is contained. The rate can be increased. Therefore, it is possible to prevent the mechanical strength of the three-dimensional fiber reinforced composite material 10 from being lowered.

(2) The holding layer 15 was a woven fabric formed by plain weaving warps 15a and wefts 15b. For this reason, when the connecting yarn 21 is pulled, the spread of the bifurcated portion 21e can be suppressed by the frictional resistance generated at the intersection of the warp yarn 15a and the weft yarn 15b.

(3) The retaining layer 15 is a woven fabric formed by plain weaving warps 15a and wefts 15b. For this reason, the warp yarn 15a and the weft yarn 15b suppress an increase in the interval defined by the warp yarn 15a and the weft yarn 15b. Therefore, even if the binding yarn 21 is pulled, the holding layer 15 itself does not spread and the bifurcated portion 21e. Can be prevented from spreading.

(4) The pitch P2 between the adjacent transverse portions is made wider than the pitch P1 of the warp 15a. For this reason, there is always at least one warp 15a between adjacent transverse portions. Since each warp 15a is prevented from unwinding the fiber bundle by the weft 15b, even if the binding yarn 21 is pulled, the movement of the surface layer yarn portion 21d is suppressed by the warp yarn 15a and the bifurcated portion 21e is prevented from spreading. can do. As the pitch P1 of the warp 15a in the holding layer 15 is narrower, the number of crossed portions of the warp 15a and the weft 15b existing per unit area increases, and the number of places where frictional resistance is generated increases. Therefore, even if the binding yarn 21 is pulled, the shape of the bifurcated portion 21e can be reliably held by the holding layer 15, and the bifurcated portion 21e can be prevented from spreading. In addition, as shown in FIG. 3, when the 1st and 2nd

crossing thread parts

21b and 21c penetrate the warp 15a, the shape of the bifurcated part 21e can be more reliably hold | maintained by the holding layer 15. FIG.

(5) The laminated body 20 is compressed in the laminating direction so that the thickness t of the laminated body 20 before forming the matrix resin 30 is thicker than the thickness t1 of the laminated body 20 after forming the matrix resin 30. Thus, a three-dimensional fiber reinforced composite material 10 was formed. For this reason, when the laminated body 20 is compressed, the length of the bonding yarn 21 in the laminating direction becomes longer than the thickness t of the laminated body 20, and becomes loose in the outermost layer of the laminated body 20. When the stacked body 20 is compressed, the folded portion 21a and the bifurcated portion 21e are crushed, and the gap formed by the bifurcated portion 21e is narrowed. Therefore, the resin pool of the bifurcated portion 21e can be reduced.

(6) The holding layer 15 is disposed on the outermost side of the stacked body 20. Therefore, the holding layer 15 is closest to the bifurcated portion 21e and can efficiently suppress the spread of the bifurcated portion 21e when the binding yarn 21 is pulled.

(7) The first to fourth reinforcing fiber bundle layers 11 to 14, the holding layer 15, the binding yarn 21, and the retaining yarn 22 were formed of carbon fibers. For this reason, the laminated body 20 is formed only with a carbon material. Therefore, the strength reduction of the three-dimensional fiber reinforced composite material 10 due to the mixture of materials other than the carbon material can be eliminated.

(8) Since the holding layer 15 is a plain weave, there are a large number of crossing portions of the warp yarn 15a and the weft yarn 15b. Therefore, when the binding yarn 21 is pulled, frictional resistance generated at the intersection of the warp yarn 15a and the weft yarn 15b is also generated at a number of locations. Thereby, the shape of the retention layer 15 is retained, and the spread of the bifurcated portion 21e can be suppressed.

Note that the above embodiment may be modified as follows.

The fibers constituting the binding yarn 21, the retaining yarn 22, and the first to fourth reinforcing fiber bundles 11a to 14a are not limited to carbon fibers. Each fiber is, for example, a high-strength organic material selected from aramid fiber, poly-p-phenylenebenzobisoxazole fiber, ultrahigh molecular weight polyethylene fiber, and the like according to the physical properties required for the three-dimensional fiber reinforced composite material 10. Inorganic fibers selected from fibers, glass fibers, ceramic fibers, and the like may be used.

In the embodiment, the warp 15a is the first yarn and the weft 15b is the second yarn, but the warp 15a may be the second yarn and the weft 15b may be the first yarn.

The holding layer 15 may be formed of glass fiber. When the three-dimensional fiber reinforced composite material 10 is used in contact with an aluminum member, electrolytic corrosion can be suppressed by the holding layer 15 that is located on the outermost side of the laminate 20 and is formed of glass fibers.

The pitch P2 may be the same as the pitch P1.

The holding layer 15 may be satin weave or twill weave.

The holding layer 15 may be formed of a nonwoven fabric or a resin film.

In the embodiment, the holding layer 15 is provided on the outermost side of the stacked body 20. However, if the holding layer 15 is positioned closer to the bifurcated portion 21 e than the retaining thread 22 in the stacking direction of the stacked body 20, the holding layer 15 is The outermost layer of the stacked body 20 may be provided on the inner side in the stacking direction.

In the embodiment, the first to fourth reinforcing fiber bundle layers 11 to 14 are connected by the auxiliary yarns 11b to 14b, respectively, but the present invention is not limited to this. For example, the reinforcing fiber bundles 11a to 14a may be connected by fusion yarns provided on one side of the first to fourth reinforcing fiber bundle layers 11 to 14. Further, in the first to fourth reinforcing fiber bundle layers 11 to 14, pins are provided at both ends in the axial direction of the reinforcing fiber bundles 11a to 14a, and the connecting yarns are hooked on the pins to attach the reinforcing fiber bundles 11a to 14a. You may connect.

In the embodiment, a thermosetting resin is used as the matrix resin 30, but other types of resins may be used.

Only one binding thread 21 and retaining thread 22 may be used.

The laminate 20 may have two or three reinforcing fiber bundle layers, or may have five or more reinforcing fiber bundle layers.

The method for producing the three-dimensional fiber reinforced composite material 10 composed of the laminate 20 and the matrix resin 30 is not limited to the RTM method.

Claims

A laminate having a plurality of fiber bundle layers laminated in a lamination direction, wherein the fiber bundle layer includes first and second outermost layers; and
A matrix resin impregnated in the laminate,
A retaining thread extending along the surface of the first outermost layer;
A binding yarn for binding the fiber bundle layer in the stacking direction,
The binding yarn is
A folded portion that is folded back so as to pass outside in the stacking direction of the retaining thread;
A first transverse yarn portion and a second transverse yarn portion that are continuous with the folded portion and extend in the lamination direction in the laminated body;
A surface layer yarn portion extending in a direction substantially perpendicular to the retaining yarn along the surface of the second outermost layer on the surface of the second outermost layer;
The surface layer yarn portion has a bifurcated portion extending in a direction opposite to the first transverse yarn portion and the second transverse yarn portion on the surface of the second outermost layer,
The laminated body is a three-dimensional fiber reinforced composite material including a holding layer located near the bifurcated portion in the lamination direction.
The three-dimensional fiber-reinforced composite material according to claim 1, wherein the holding layer is positioned closer to the bifurcated portion than the retaining thread in the stacking direction of the laminate.
The three-dimensional fiber reinforced composite material according to claim 1 or 2, wherein the holding layer is the second outermost layer.
The holding layer is a plurality of first yarns that are fiber bundles and arranged in parallel to each other, and a plurality of first yarns that are fiber bundles and arranged in parallel to each other, and extend in a direction intersecting with the first yarns. The three-dimensional fiber-reinforced composite material according to any one of claims 1 to 3, which is a woven fabric having two yarns.
A plurality of retaining yarns are arranged so as to extend in parallel with each other at intervals, and the pair of the folded portion and the first and second transverse yarn portions continuous thereto correspond to each of the plurality of retaining yarns. Provided,
The first yarn extends in the same direction as the retaining yarn, and is arranged at intervals in a direction perpendicular to the retaining yarn,
In the direction along the surface of the laminate and in the direction perpendicular to the retaining yarn, the pair of the first and second transverse yarn portions are arranged at an interval equal to or greater than the arrangement interval of the first yarn. The three-dimensional fiber-reinforced composite material according to claim 4.
The three-dimensional fiber-reinforced composite material according to any one of claims 1 to 5, wherein the fiber bundle layer, the retaining yarn, the binding yarn, and the holding layer are formed of carbon fibers.
The three-dimensional fiber reinforced composite according to any one of claims 1 to 3, wherein the holding layer is a layer formed of satin weave or twilled fibers, or a layer including a nonwoven fabric or a resin film. Wood.