JP2016114094A - Energy absorption member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy absorption member capable of forming a trigger part and a general part by change of a fiber structure, and capable of suppressing strength deterioration of the general part.SOLUTION: A fiber structure 11 constituting an energy absorption member 10 has a trigger part 23 and a general part 24. A fiber layer 13 constituting the fiber structure 11 includes a crimp angle increase part 13a that is provided at a position closer to the trigger part 23 than the general part 24 and that has a crimp angle larger than the general part 24.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an energy absorbing member that is configured by impregnating a fiber structure with a resin and absorbs impact energy when subjected to an impact load.

  For example, an energy absorbing member is disposed between the bumper and the vehicle body frame, and when the energy absorbing member receives an excessive impact load, it absorbs the impact energy by breaking. As an energy absorbing member, a fiber reinforced composite material configured by impregnating a fiber structure with a resin is known. In addition, the energy absorbing member has a trigger portion that becomes a starting point of destruction when receiving an excessive impact load.

  For example, in Patent Document 1, the trigger part is formed by shouldering the tip part of the FRP member formed in a cylindrical shape into a tapered shape so as to be tapered with respect to the thickness. However, in the manufacture of the energy absorbing member, the design of the shape that can be the starting point of destruction, the processing for making such a shape, etc. is troublesome, so the trigger portion is changed by changing the fiber structure of the fiber structure. Proposed to manufacture.

  For example, as shown in FIG. 8, the shock absorbing composite structure 80 disclosed in Patent Document 2 is configured by impregnating a resin into a fiber laminate 84 (fiber structure) in which a plurality of reinforcing fiber layers 84a are laminated. Yes. The shock absorbing composite material structure 80 does not improve the interlayer strength of the fiber laminate 84 in the range from the tip in the direction in which the load is applied (hereinafter referred to as the load direction) to the predetermined position along the load direction. Thus, the trigger part 82 is provided. On the other hand, from the predetermined position along the load direction, an interlayer reinforcing region 81 (general portion) in which the interlayer strength is improved by the need ring 83 is used. That is, the trigger portion 82 and the interlayer reinforcing region 81 are manufactured by changing the fiber structure by the needling 83. In such an impact-absorbing composite structure 80, when an excessive impact load is applied, the trigger portion 82 is locally destroyed prior to the interlayer reinforcement region 81 to absorb energy, and the progress of the fracture in the interlayer reinforcement region 81 is achieved. Suppress.

JP-A-7-224874 JP 2004-324814 A

  However, in the impact-absorbing composite structure 80 of Patent Document 2, the needling 83 is performed on the reinforcing fiber layer 84a from the direction orthogonal to the load direction in order to improve the interlayer strength. For this reason, in each of the reinforcing fiber layers 84a, the load direction yarns are crimped (bent) at the intersection of the yarn extending in the load direction (load direction yarn) and the need ring 83 extending in the direction intersecting the yarn. In the places where crimps are generated, the reinforcing fibers cannot exhibit the tensile strength that should be originally expressed. In the impact-absorbing composite structure 80, the distance between the needling 83 becomes narrower as the distance from the trigger portion 82 in the interlayer reinforcing region 81, that is, the closer to the base end of the interlayer reinforcing region 81 is. For this reason, in the interlayer reinforcement area | region 81 which requires the intensity | strength more than the trigger part 82 and also needs the intensity | strength for suppressing progress of destruction, the intensity | strength has fallen to the base end.

  The present invention has been made in view of the above problems, and its purpose is energy that can suppress a decrease in strength of the general part while being able to form the trigger part and the general part by changing the fiber structure. The object is to provide an absorbent member.

  An energy absorbing member for solving the above problems is an energy absorbing member configured to impregnate a fiber structure with a resin and absorbs impact energy when subjected to an impact load, wherein the fiber structure is A plurality of fabric fiber layers are formed by crossing a load direction yarn extending in a direction in which a load is applied and a cross yarn extending in a direction crossing the load direction yarn, and the plurality of fiber layers are subjected to the load. The fiber structure is positioned on one end side in the direction in which the load is applied, and the trigger portion that is a starting point of fracture when receiving an impact load, and the direction in which the load is applied And a general portion that is continuous to the other end side than the trigger portion and has a higher strength in the load direction than the trigger portion and suppresses the progress of breakage, and the load is applied to the fiber layer. Direction If the angle of the load direction yarn to the crimp angle is a crimp angle, at least one of the plurality of fiber layers is a crimp angle in which the crimp angle is larger than the general part at a position closer to the trigger part than the general part. The gist is to provide an increasing portion.

  According to this, in the fiber layer constituting the fiber structure, the larger the crimp angle, the lower the tensile strength of the load direction yarn in the direction in which the load is applied. Conversely, the smaller the crimp angle, the higher the tensile strength of the load direction yarn in the direction in which the load is applied. Therefore, it is possible to form the energy absorbing member having the trigger part and the general part only by adjusting the crimp angle of the fiber layer, that is, by changing the fiber structure. The manufacture of the part becomes easy.

In addition, the fiber structure does not bond the layers of the fiber layer, the crimp in the load direction yarn does not occur due to the interlayer bond, and the strength of the general part does not decrease.
Moreover, about an energy absorption member, you may vary the said crimp angle in the site | part which comprises the said general part in the said fiber layer along the direction where the said load is added.

  According to this, the tensile strength of the general part can be varied along the direction in which the load is applied. For example, if the crimp angle of the general portion is reduced as the distance from the trigger portion increases along the direction in which the load is applied, the tensile strength in the direction in which the load is applied can be increased as the distance from the trigger portion increases. As a result, the closer to the base end (root) of the general part, the easier it is to suppress the progress of destruction.

Moreover, you may manufacture the said general part by braiding about an energy absorption member.
According to this, even if it is the structure which makes the crimp angle in a general part differ, it can manufacture easily by a braiding apparatus. The fiber layer manufactured by the braiding device has a load direction yarn corresponding to the core yarn and an oblique yarn intersecting with the load direction yarn. In the present invention, the fiber layer is manufactured by the braiding device. The fabric also includes a fiber layer formed by crossing the load direction yarn and the skew yarn.

Moreover, about the energy absorption member, in the fiber layer, the load direction yarn may be continuous over a portion constituting the trigger portion and a portion constituting the general portion.
According to this, in a fiber structure, a trigger part and a general part can be made into one, a load can be suitably transmitted from a trigger part to a general part, and progress of destruction can be controlled suitably.

  According to the present invention, it is possible to form the trigger part and the general part by changing the fiber structure, but it is possible to suppress the strength reduction of the general part.

The perspective view which shows the energy absorption member of 1st Embodiment. (A) is a figure which expands and shows the fiber structure of a crimp angle increase part, (b) is a figure which expands and shows the fiber structure of a crimp angle reduction part. (A) is sectional drawing which shows typically the fiber structure of the energy absorption member of 1st Embodiment, (b) is the partial expanded sectional view which shows a crimp angle increase part typically, (c) is a crimp angle reduction part. The partial expanded sectional view which shows typically. (A) is a figure which expands and shows the fiber structure of the trigger part in the energy absorption member of 2nd Embodiment, (b) is a figure which expands and shows the fiber structure of a general part. (A) is a figure which expands and shows the fiber structure of the crimp angle increase part in the energy absorption member of 3rd Embodiment, (b) is a figure which expands and shows the fiber structure of a crimp angle reduction part. Sectional drawing which shows typically the fiber structure of the energy absorption member of 3rd Embodiment. The partial expanded sectional view which shows the other example which changed the crimp angle. The figure which shows background art.

Hereinafter, a first embodiment in which an energy absorbing member is embodied will be described with reference to FIGS.
As shown in FIG. 1, the energy absorbing member 10 is a fiber-reinforced composite material, and is configured by impregnating a tubular fiber structure 11 with a thermosetting resin (not shown) as a matrix resin. . The energy absorbing member 10 absorbs energy by breaking when receiving an excessive impact load along the axial direction of the cylindrical body. Hereinafter, the direction in which a load is applied to the energy absorbing member 10 (the axial direction of the cylinder) is referred to as a load direction Z. In addition, as a thermosetting resin, an epoxy resin is used, for example.

  As shown to Fig.3 (a), in the energy absorption member 10, the fiber structure 11 has multiple fiber layers 13 as a textile fabric, and these fiber layers 13 are laminated | stacked so that it may mutually become parallel. As shown in FIG. 1, in the energy absorbing member 10, the plurality of fiber layers 13 are stacked concentrically around the central axis extending in the load direction Z. Long lap. In the fiber structure 11, the lamination direction X is a direction in which the fiber layers 13 are laminated, and a direction parallel to the radial direction of the fiber structure 11.

  As shown in FIGS. 2A and 2B, the fiber layer 13 is a woven fabric in which a plurality of warps 14 and a plurality of wefts 15 are combined. A plurality of warp yarns 14 as load direction yarns are arranged in the circumferential direction of the fiber structure 11 and extend in the load direction Z. A plurality of wefts 15 as intersecting yarns that intersect with the warp yarns 14 are arranged in the load direction Z in a state of intersecting the warp yarns 14 at a predetermined angle (90 degrees in this embodiment). The warp yarns 14 and the weft yarns 15 are all composed of untwisted fiber bundles made of the same kind of material. In this embodiment, untwisted fiber bundles made of carbon fibers are used for the warp 14 and the weft 15. In the carbon fiber bundle, hundreds to tens of thousands of fine carbon fibers are bundled to form one fiber bundle, and the fiber bundle having the number of fibers suitable for the required performance is selected.

  As shown in FIG. 1, in the energy absorbing member 10, the fiber structure 11 has a first end surface 11 a on a tip surface that is an end surface to which a load is first applied among both ends in the load direction Z, and the other end. It has the 2nd end surface 11b in the base end surface which is an end surface. Further, the fiber structure 11 has a trigger portion 23 at the tip including the first end surface 11a in the load direction Z. Moreover, the fiber structure 11 has the general part 24 in the 2nd end surface 11b side rather than the trigger part 23. FIG. In the length along the load direction Z, the general portion 24 is longer than the trigger portion 23. And in the fiber structure 11, the trigger part 23 is a site | part used as the starting point of destruction, when an impact load is received. Further, the general portion 24 is continuous to the base end side (the second end surface 11b side) from the trigger portion 23 in the load direction Z, has a higher strength in the load direction than the trigger portion 23, and suppresses the progress of breakage. It is a part.

  The trigger portion 23 is formed by a crimp angle increasing portion 13a included in all the fiber layers 13 constituting the fiber structure 11, and the general portion 24 is a crimp angle decreasing included in all the fiber layers 13 constituting the fiber structure 11. It is formed by the part 13b. That is, the fiber layer 13 includes a crimp angle increasing portion 13a in which the crimp angle is increased at a position closer to the trigger portion 23 than the general portion 24.

  As shown in FIGS. 2A and 3, in the fiber layer 13, a portion constituting the trigger portion 23 in the process in which the warp yarn 14 extends from the first end surface 11 a toward the second end surface 11 b along the load direction Z. Then, the warps 14 are folded back along the outer surface of each weft 15.

  More specifically, the warp yarn 14 is folded inward in the stacking direction X along the outer surface of one weft 15, and then the warp yarn 14 in the stacking direction X along the outer surface of the adjacent weft 15 in the load direction Z. Wrapped outward. Thus, every time the warp 14 intersects with the weft 15, the warp 14 is bent in a direction opposite to the weft 15 adjacent in the load direction Z, and the warp 14 is crimped by the bending.

  As shown in FIG. 3 (a) or 3 (b), in the fiber layer 13, the surface on which the surfaces of the warp 14 and the weft 15 are present is defined as a surface 13c, and both surfaces 13c are connected in the shortest distance. The direction along the stacking direction X is the thickness direction of the fiber layer 13. The surface 13c of the fiber layer 13 is parallel to the load direction Z. In the fiber layer 13, the wefts 15 adjacent to each other in the load direction Z are arranged in a state shifted in the thickness direction due to the tension in the load direction Z of the warp 14. The warp 14 is crimped due to the displacement of the wefts 15 in the thickness direction. Here, in a state where the warp yarn 14 extends toward the weft yarn 15, an acute angle θ1 formed between the axis M of the warp yarn 14 and the surface 13c (load direction Z) of the fiber layer 13 is defined as a crimp angle. To do.

  As shown in FIG. 3B, the crimp angle is larger in the portion constituting the trigger portion 23 than in the crimp angle reduction portion 13b. In the crimp angle increasing portion 13a, the warps 14 meander so as to bend in the opposite directions for each weft 15, and the crimp angle is larger than the other portions. For this reason, in the trigger part 23 comprised by the crimp angle increase part 13a, intensity | strength is not fully exhibited.

  As shown in FIG. 2A, in the crimp angle increasing portion 13a constituting the trigger portion 23, the wefts 15 extending in the circumferential direction of the fiber structure 11 are each one of the warp yarns 14 arranged in the circumferential direction. It is alternately folded along the outer surface of the book and crossed with each warp 14. For this reason, each weft 15 is bent at a place where it intersects with each warp 14. Therefore, in the weft 15, a crimp that bends along the warp 14 occurs at the intersection 20 with the warp 14.

  As shown in FIGS. 2B and 3A, in the fiber layer 13, in the process in which the warp yarn 14 extends from the crimp angle increasing portion 13a toward the second end surface 11b, the portion constituting the general portion 24, In the crimp angle reducing portion 13b, the warp 14 is folded along the outer surface of the weft 15 every time the four wefts 15 are straddled. For this reason, compared with the case where the warp 14 straddles the weft 15 one by one, the crimp angle which is the acute angle θ1 formed between the axis M of the warp 14 and the surface 13c of the fiber layer 13 is small.

  In the intersecting portion 20 where the warp yarns 14 are folded, the warp yarns 14 are not bent as much as the crimp angle increasing portions 13a, but some crimps are generated. In the crimp angle reducing portion 13b, the warp yarn 14 has a straight portion 14a in the portion sandwiched between the intersecting portions 20 where the warp yarn 14 is folded back in the load direction Z. The crimp angle of the straight portion 14a is the crimp angle. It is smaller than the increase part 13a. In the general portion 24, a plurality of straight portions 14a are provided along the load direction Z, and all the straight portions 14a have the same length.

  Further, as shown in FIG. 3C, in the crimp angle reducing portion 13b, the wefts 15 extending in the circumferential direction of the fiber structure 11 are along the outer surface of each warp yarn 14 arranged in the circumferential direction. They are folded back alternately. In the straight line portion 14a, all the wefts 15 straddling the straight line portion 14a are arranged together outside or inside in the stacking direction X with respect to the straight line portion 14a. For this reason, no crimp is generated in the straight portion 14a.

  In the fiber layer 13, the warp yarn 14 extends over the entire load direction Z, and the warp yarn 14 is continuous over the crimp angle increasing portion 13a and the crimp angle decreasing portion 13b. Therefore, in the fiber structure 11, the trigger portion 23 and the general portion 24 are connected in the load direction Z.

  And the energy absorption member 10 is thermosetting to the fiber structure 11 which has the trigger part 23 comprised by laminating | stacking the crimp angle increase part 13a, and the general part 24 comprised by laminating | stacking the crimp angle decrease part 13b. Manufactured by impregnating and curing resin. The resin is impregnated and cured by an RTM (resin transfer molding) method.

Next, the operation of the energy absorbing member 10 will be described.
In the energy absorbing member 10 in which the fiber structure 11 having the trigger part 23 and the general part 24 is used as the reinforcing fiber, when the first end surface 11a receives an excessive impact load along the load direction Z, the trigger part 23 Absorbs impact energy by causing local destruction. Thereafter, the general part 24 suppresses the progress of destruction.

According to the above embodiment, the following effects can be obtained.
(1) In the fiber structure 11, a crimp angle increasing portion 13 a is provided in each fiber layer 13 continuously to the crimp angle decreasing portion 13 b, and the crimp angle of the warp 14 is formed by the crimp angle increasing portion 13 a and the crimp angle decreasing portion 13 b The trigger part 23 is made larger than the general part 24. The greater the crimp angle of the warp 14, the lower the tensile strength of the warp 14 in the load direction Z. Therefore, the trigger part 23 and the general part 24 can be formed in the fiber structure 11 simply by adjusting the crimp angle of the warp yarn 14, that is, only by changing the fiber structure. It can be carried out.

  (2) The crimp angle of the warp 14 is larger at the trigger portion 23 than at the general portion 24. The smaller the crimp angle of the warp 14 is, the higher the tensile strength of the warp 14 in the load direction Z is. Therefore, the trigger part 23 and the general part 24 can be formed in the fiber structure 11 only by adjusting the crimp angle of the warp 14, that is, by changing the fiber structure.

(3) Since the fiber structure 11 does not bond the layers of the fiber layer 13 and does not cause crimping due to interlayer bonding, the strength of the general portion 24 is not reduced.
(4) In the fiber structure 11, the size of the crimp angle is the same in the general portion 24 even if the general portion 24 moves away from the trigger portion 23 along the load direction Z and approaches the base end (root). For this reason, it can be set as the same intensity | strength in the whole general part 24 along the load direction Z.

  (5) In the fiber layer 13, the crimp angle increasing portion 13a and the crimp angle decreasing portion 13b are formed by weaving the warp yarn 14 and the weft yarn 15. And the warp 14 continues over the crimp angle increase part 13a and the crimp angle decrease part 13b, and the crimp angle increase part 13a and the crimp angle decrease part 13b are connected. For this reason, for example, compared with the case where the crimp angle increasing portion 13a and the crimp angle decreasing portion 13b are separately manufactured and joined to form the fiber layer 13, the strength near the boundary between the trigger portion 23 and the general portion 24 is obtained. Can be improved.

(Second Embodiment)
Next, a second embodiment in which the energy absorbing member is embodied will be described with reference to FIG. In the second embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIG. 4A and FIG. 4B, the energy absorbing member 30 of the second embodiment is similar to the energy absorbing member 10 of the first embodiment. The fiber structure 31 is a laminate in which a plurality of fiber layers 32 as woven fabrics are laminated. The fiber layer 32 includes a crimp angle increasing portion 32a and a crimp angle decreasing portion 32b, and the fiber structure 31 is a stack of a trigger portion 33 that is a laminate of the crimp angle increasing portion 32a and a crimp angle decreasing portion 32b. And a general part 34 which is a body. The fiber structure 31 according to the second embodiment is a braided structure manufactured using a braiding device. The fiber structure 31 has a first end face (not shown) on one end face in the load direction Z and a second end face (not shown) on the other end face.

  The fiber layer 32 of the fiber structure 31 is formed of a plurality of first skew yarns 35, a plurality of second skew yarns 36, and a plurality of load direction yarns 37 that are core yarns. The first skew yarn 35 and the second skew yarn 36 correspond to cross yarns extending in a direction crossing the load direction yarn 37. In the fiber layer 32, the first skew yarns 35 are arranged in a direction intersecting with the axial direction of the load direction yarn 37 at an angle θ, and the second skew yarns 36 are arranged with respect to the axial direction of the load direction yarn 37. Are arranged at an angle −θ opposite to the angle θ at which the first skew yarn 35 intersects the axial direction of the load direction yarn 37. In this embodiment, the angle θ is 45 °. Further, the load direction threads 37 are arranged in parallel to the load direction Z. The load direction yarn 37 is arranged so as to correspond to all the intersecting portions 38 of the first skewed yarn 35 and the second skewed yarn 36.

  As shown in FIG. 4A, in the crimp angle increasing portion 32a constituting the trigger portion 33, the load direction yarn 37 includes a first skewed yarn 35 and a second skew yarn arranged along the load direction Z. Every other crossing portion 38 of the row yarns 36 is folded back toward the outside or the inside in the stacking direction X. More specifically, in the process in which the load direction yarn 37 extends from the first end surface toward the second end surface, the load direction yarn 37 is folded back toward the inner side in the stacking direction X along the outer surface of one intersection portion 38. Next, it is folded toward the outside in the stacking direction X along the outer surface of the intersecting portion 38 adjacent to the load direction Z. In this way, each time the load direction yarn 37 intersects with the intersection portion 38, the load direction yarn 37 is bent in a direction opposite to the intersection portion 38 adjacent to the load direction Z, and the load direction yarn 37 is crimped by the bending. . That is, in the crimp angle increasing portion 32a, each load direction thread 37 meanders so as to bend in the opposite direction for each crossing portion 38. For this reason, in the trigger part 33 which laminated | stacked the crimp angle increase part 32a, intensity | strength is not fully exhibited.

  Further, in the crimp angle increasing portion 32a, the first skew yarn 35 and the second skew yarn 36 are folded back along the outer surface of each of the load direction yarns 37 arranged in the circumferential direction. It intersects with the load direction thread 37. For this reason, the first skewed yarn 35 and the second skewed yarn 36 are bent at a place where they intersect with the load direction yarns 37. Therefore, in the first skewed yarn 35 and the second skewed yarn 36, a crimp is generated at the intersection 38 with the load direction yarn 37.

  As shown in FIG. 4B, in the fiber layer 32, in the crimp angle decreasing portion 32b constituting the general portion 34, the load direction yarn 37 extends from the crimp angle increasing portion 32a toward the second end surface. The directional yarn 37 is folded along the outer surface of the crossing portion 38 every time the four crossing portions 38 are straddled. After being folded, the load direction yarn 37 straddles the next four intersecting portions 38 on the opposite side to the intersecting portion 38 straddled previously.

  In the crossing portion 38 where the load direction yarn 37 is folded back, the load direction yarn 37 is not bent like the crimp angle increasing portion 32a, but is crimped. And in the crimp angle reduction | decrease part 32b, the crimp angle formed in the part extended between the adjacent intersection parts 38 becomes smaller than the crimp angle increase part 32a.

  In the crimp angle reducing portion 32 b, the first skewed yarn 35 and the second skewed yarn 36 that intersect the load direction yarn 37 are one of the load direction yarns 37 arranged in the circumferential direction of the fiber structure 31. It is folded along the outer surface of one book.

Therefore, according to the second embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(4) In the energy absorbing member 30 of the second embodiment, the fiber structure 31 can be manufactured using a braiding device, and the cylindrical energy absorbing member 30 can be easily manufactured.

(Third embodiment)
Next, a third embodiment in which the energy absorbing member is embodied will be described with reference to FIGS. In the third embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  Similar to the energy absorbing member 10 of the first embodiment, the energy absorbing member 40 of the third embodiment has a cylindrical fiber structure 41, and the fiber structure 41 is a stack of a plurality of fiber layers 42. Is the body. The fiber layer 42 includes a crimp angle increasing portion 42a and a crimp angle decreasing portion 42b, and the fiber structure 41 is a stack of a trigger portion 43 that is a laminate of the crimp angle increasing portion 42a and a crimp angle decreasing portion 42b. And a general part 44 which is a body. The fiber structure 41 has a first end face 41a on one end face in the load direction Z, and a second end face 41b on the other end face. The fiber structure 41 is a laminate of a plurality of fiber layers 42.

  The fiber layer 42 is formed of a woven fabric in which a plurality of warp yarns 45 as load direction yarns and a plurality of weft yarns 46 are combined. As shown in FIG. 5A, the crimp angle increasing portion 42a constituting the trigger portion 43 has the same configuration as the crimp angle increasing portion 13a of the first embodiment, and the warp yarn 45 is in the load direction Z. Each weft 46 is meandering so as to bend in opposite directions.

  On the other hand, as shown in FIGS. 5B and 6, in the crimp angle reducing portion 42 b constituting the general portion 44, there are a plurality of continuous straight portions 45 a straddling the two wefts 46 in the load direction Z. In addition, there are a plurality of linear portions 45b continuously straddling the three wefts 46 in the load direction Z. Further, in the crimp angle reducing portion 42b, a plurality of straight portions 45c straddling the four wefts 46 are continuously provided in the load direction Z continuously to the straight portions 45b straddling the three wefts 46. Each linear part 45a, 45b, 45c is located between the crossing parts 48 where the warp yarn 45 is folded back, respectively. Therefore, in the crimp angle reduction part 42b, the number of the wefts 46 which a linear part straddles gradually increases with 2, 3, 4, and continuously. Therefore, the crimp angle of the warp 45 is gradually decreased toward the base end (root) of the fiber structure 41 along the load direction Z.

Therefore, according to the third embodiment, the following effects can be obtained in addition to the effects described in the first embodiment.
(5) In the energy absorbing member 40 of the third embodiment, the crimp angle gradually becomes smaller toward the proximal end (root) of the fiber structure 41 along the load direction Z. That is, the strength in the general part 44 gradually increases toward the base of the general part 44. For this reason, the impact load can be suitably absorbed by the general portion 44.

In addition, you may change the said embodiment as follows.
In the third embodiment, the number of straight portions having the same length may be changed as appropriate.
In the second embodiment, the interval at which the load direction thread 37 is folded back at the crimp angle reduction portion 32b (general portion 34) may be appropriately changed.

  In the second embodiment, in the crimp angle reduction portion 32b (general portion 34), the interval at which the load direction thread 37 is folded back is gradually increased as it goes toward the root of the fiber structure 31 along the load direction Z. The crimp angle may be gradually reduced. When configured in this manner, the fiber layer 32 (fiber structure 31) of the second embodiment can be manufactured by using a braiding device, and therefore, even if the fiber layer 32 has different crimp angles, it is easy. Can be manufactured.

  In the first and third embodiments, the wefts 15 and 46 are alternately folded one by one with respect to the plurality of warp yarns 14 and 45 arranged in the circumferential direction. , 45 may be changed as appropriate.

  In each embodiment, the crimp angle increasing portion may be provided in only one of the plurality of fiber layers 13, 32, 42 constituting the fiber structures 11, 31, 41, or not all of the plurality of sheets. You may provide a crimp angle increase part only in the fiber layers 13, 32, and 42. FIG.

  In each embodiment, if the crimp angle of the crimp angle increasing portions 13a, 32a, 42a is larger than the crimp angle of the crimp angle decreasing portions 13b, 32b, 42b, the crimp angle at the crimp angle increasing portions 13a, 32a, 42a is set. , And may vary along the load direction Z.

  In each embodiment, if the crimp angle of the crimp angle increasing portions 13a, 32a, 42a is larger than the crimp angle of the crimp angle decreasing portions 13b, 32b, 42b, the crimp angle increasing portions 13a, 32a, 42a and the crimp angle decreasing The fiber structure may be different between the portions 13b, 32b, and 42b.

In the first and second embodiments, the number of wefts 15 and 46 that the straight portions 14a and 37a straddle may be changed as appropriate.
In each embodiment, if the crimp angle of the crimp angle increasing portions 13a, 32a, 42a is larger than the crimp angle of the crimp angle decreasing portions 13b, 32b, 42b, the fiber layers 13, 32, 42 are formed separately. The crimp angle increasing portions 13a, 32a, 42a and the crimp angle decreasing portions 13b, 32b, 42b may be connected and integrated.

  In each embodiment, the crimp angles of the crimp angle increasing portions 13a, 32a, 42a and the crimp angle decreasing portions 13b, 32b, 42b are set as shown in FIG. You may change it by increasing the thickness of.

In each embodiment, the thermosetting resin is used as the matrix resin, but other types of resins may be used.
In each embodiment, the number of fiber layers 13, 32, and 42 to be stacked may be arbitrarily changed.

  The warp yarns 14 and 45, the weft yarns 15 and 46, the first skew yarn 35, the second skew yarn 36, and the load direction yarn 37 are not limited to carbon fibers. For example, each yarn may be changed as appropriate in accordance with physical properties required for the energy absorbing members 10, 30, and 40. Specific examples of the yarn include aramid fiber, poly-p-phenylenebenzobisoxazole fiber, ultrahigh molecular weight polyethylene fiber, glass fiber, ceramic fiber, and the like.

  The shape of the fiber structures 11, 31 and 41 may not be cylindrical, and may be a columnar shape or a plate shape in which the load direction yarn extends in the load direction Z.

  Z ... load direction, 10, 30, 40 ... energy absorbing member, 11, 31, 41 ... fiber structure, 13, 32, 42 ... fiber layer, 13a, 32a, 42a ... crimp angle increasing part, 14, 45 ... load Warp yarn as directional yarn, 15, 46 ... Weft yarn as cross yarn, 23, 33, 43 ... Trigger portion, 24, 34, 44 ... General portion, 35 ... First skew yarn as cross yarn, 36 ... Cross Second skew yarn as a yarn, 37... Load direction yarn.

Claims (4)

An energy absorbing member constructed by impregnating a fiber structure with resin and absorbing impact energy when subjected to an impact load,
The fiber structure includes a plurality of fabric fiber layers formed by crossing a load direction yarn extending in a direction in which a load is applied and a cross yarn extending in a direction intersecting the load direction yarn, and a plurality of fibers. The layers are stacked so as to be parallel to the direction in which the load is applied,
The fiber structure is located on one end side in the direction in which the load is applied, and a trigger portion that becomes a starting point of destruction when receiving an impact load;
In the direction in which the load is applied, it has a general part that is continuous to the other end side than the trigger part, and has a higher strength in the load direction than the trigger part and suppresses the progress of breakage,
In the fiber layer, when the angle of the load direction thread relative to the direction in which the load is applied is a crimp angle,
At least one of the plurality of fiber layers includes a crimp angle increasing portion in which the crimp angle is larger than that of the general portion at a position closer to the trigger portion than the general portion.   The energy absorbing member according to claim 1, wherein in the fiber layer, the crimp angle at a portion constituting the general portion is varied along a direction in which the load is applied.   The energy absorbing member according to claim 2, wherein the general part is manufactured by braiding.   In the said fiber layer, the said load direction thread | yarn is continuing over the site | part which comprises the said trigger part, and the site | part which comprises the said general part, The energy as described in any one of Claims 1-3. Absorbing member.