Shock absorbing materials

Abstract

To inexpensively obtain a constitution which is stably and easily broken when receiving an impact load via a connecting member while increasing connecting rigidity with the connecting member, in an impact absorption member.SOLUTION: A first slit forming part 24 and a second slit forming part 25 are joined to each other by a connecting member 12 in a state that the connecting member 12 inserted into a slit 27 is sandwiched by the first slit forming part 24 and the second slit forming part 25. By this constitution, an impact absorption member 20 is integrated with the connecting member 12. When the connecting member 12 located at an input side of an impact load receives the impact load, the impact absorption member 20 receives the impact load via the connecting member 12 from a direction orthogonal to a lamination direction Z. At this time, since the connecting member 12 is inserted into the slit 27, when the impact absorption member 20 receives the impact load via the connecting member 12, the second slit forming part 25 can be made to serve as a start point of breakage.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a shock absorbing member that absorbs impact energy when subjected to an impact load. [Background technology]

[0002] A shock absorbing member is known that is constructed by combining a matrix material with a fiber structure that is a multilayered fabric. The fiber structure that is a multilayered fabric is formed by binding a first yarn layer formed of a first yarn and a second yarn layer formed of a second yarn that crosses the first yarn in a laminated state.

[0003] A connecting member located on the input side of the impact load is connected to such an impact absorbing member so that the impact load is input from a direction perpendicular to the lamination direction of the first thread layer and the second thread layer, as in Patent Document 1. Then, when the impact absorbing member receives the impact load via the connecting member, the impact absorbing member absorbs the impact energy. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-150726 A Summary of the Invention [Problem to be solved by the invention]

[0005] In such an impact absorbing member, it is desirable to realize a configuration at low cost that increases the connection strength with the connecting member while also stably facilitating destruction when subjected to an impact load via the connecting member. [Means for solving the problem]

[0006] The impact absorbing member that solves the above problem is constructed by compounding a matrix material with a fiber structure that is a multilayered fabric in which a first yarn layer formed by a first yarn and a second yarn layer formed by a second yarn intersecting the first yarn are restrained in a stacked state, and a connecting member located on the input side of the impact load is connected so that the impact load is input from a direction perpendicular to the stacking direction of the first yarn layer and the second yarn layer, and the impact absorbing member absorbs impact energy when the impact load is received via the connecting member, and the impact absorbing member includes a general portion in which all of the first yarn layer and the second yarn layer are restrained in the stacking direction, and a connecting member located on the input side of the impact load is connected so that the impact load is input from a direction perpendicular to the stacking direction of the first yarn layer and the second yarn layer. The connecting member has a first slit forming portion and a second slit forming portion that branch off on both sides in the stacking direction and overlap in the stacking direction, and since the first slit forming portion and the second slit forming portion are not constrained to each other in the stacking direction, a slit through which the connecting member is inserted is formed between the first slit forming portion and the second slit forming portion, and with the connecting member inserted into the slit sandwiched between the first slit forming portion and the second slit forming portion, the first slit forming portion and the second slit forming portion are each joined to the connecting member, thereby being integrated with the connecting member.

[0007] According to this, the shock absorbing member is integrated with the connecting member by sandwiching the connecting member inserted into the slit between the first slit forming portion and the second slit forming portion, and then joining the first slit forming portion and the second slit forming portion to the connecting member, respectively. Therefore, the shock absorbing member is joined to the connecting member from both sides in the stacking direction of the first thread layer and the second thread layer. Therefore, compared to a case where the shock absorbing member is joined to the connecting member from one side in the stacking direction of the first thread layer and the second thread layer, for example, the joining area between the shock absorbing member and the connecting member is increased. As a result, the connection strength between the shock absorbing member and the connecting member can be increased.

[0008] When the connection member located on the input side of the impact load receives the impact load, the impact absorbing member receives the impact load through the connection member from a direction perpendicular to the lamination direction of the first thread layer and the second thread layer. At this time, since the connection member is inserted into the slit, at least one of the first slit forming portion and the second slit forming portion can become the starting point of destruction when the impact absorbing member receives the impact load through the connection member. Therefore, destruction of the impact absorbing member can be stably performed.

[0009] Here, for example, consider a configuration in which a connecting member is connected to an impact absorbing member that has only a general portion. In this case, in order to ensure that the impact absorbing member is destroyed stably, it is necessary to form in advance by machining a portion in the impact absorbing member that will be the starting point of destruction when the impact absorbing member receives an impact load through the connecting member. Therefore, a separate process is required to form the portion that will be the starting point of destruction in the impact absorbing member, which results in a problem of increased manufacturing costs.

[0010] On the other hand, when manufacturing an impact absorbing member having a general portion, a first slit forming portion, and a second slit forming portion, the weaving structure is simply changed in the weaving process of the multilayer fabric. Therefore, for example, the manufacturing cost is almost the same as that of the weaving process of the multilayer fabric when manufacturing an impact absorbing member having only the general portion. Therefore, a separate process for forming a portion that becomes the starting point of destruction in the impact absorbing member is not required. Therefore, it is possible to realize at low cost a configuration in which destruction is easily and stably performed when an impact load is received through the connecting member in the impact absorbing member. As described above, it is possible to realize at low cost a configuration in which destruction is easily and stably performed when an impact load is received through the connecting member while increasing the connection strength with the connecting member in the impact absorbing member.

[0011] In the above-mentioned impact absorbing member, the fiber structure is cylindrical, the first slit formation portion is located outwardly of the second slit formation portion, the first slit formation portion overlaps the general portion in the axial direction of the fiber structure, and the second slit formation portion does not overlap the general portion in the axial direction of the fiber structure and protrudes inwardly from the general portion.

[0012] According to this, since the first slit forming portion overlaps with the general portion in the axial direction of the fiber structure, it is easily supported by the general portion when the shock absorbing member receives an impact load via the connecting member. On the other hand, since the second slit forming portion does not overlap with the general portion in the axial direction of the fiber structure, it is difficult for the shock absorbing member to be supported by the general portion when the shock absorbing member receives an impact load via the connecting member. Therefore, when the shock absorbing member receives an impact load via the connecting member, the second slit forming portion is likely to become the starting point of destruction. Therefore, destruction of the shock absorbing member is likely to occur stably.

[0013] In the above shock absorbing member, the connecting member made of a metallic material may be inserted into the slit. In this way, even if the connecting member is made of a metallic material, the connection strength between the impact absorbing member and the connecting member can be increased. Effect of the Invention

[0014] According to this invention, it is possible to realize at low cost a configuration in an impact absorbing member that increases the connection strength with the connecting member while also making it easier for destruction to occur stably when subjected to an impact load via the connecting member. [Brief description of the drawings]

[0015] [Figure 1] 2 is a cross-sectional view for explaining a shock absorbing member in the embodiment. FIG. [Diagram 2] FIG. 4 is an exploded perspective view showing the relationship between the impact absorbing member and the connecting member. [Diagram 3] FIG. 2 is a diagram showing a schematic diagram of a fiber structure. [Figure 4] FIG. 2 is an enlarged partial perspective view showing a part of the impact absorbing member. [Diagram 5] 4 is a cross-sectional view showing a schematic state in which the impact absorbing member is subjected to an impact load. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of the impact absorbing member will be described below with reference to Figs. 1 to 5. The impact absorbing member of this embodiment is used in a vehicle. The impact absorbing member is disposed between the front bumper and front side member of the vehicle. In the following description, "front", "rear", "left", "right", "upper", and "lower" refer to the state in which the driver of the vehicle faces forward (forward travel). The left-right direction coincides with the vehicle width direction.

[0017] <Vehicle 10> As shown in Fig. 1, a vehicle 10 includes a front bumper 11, a connecting member 12, and an impact absorbing member 20. The front bumper 11 extends in the vehicle width direction. The connecting member 12 is a bracket that supports the impact absorbing member 20 on the front bumper 11. The impact absorbing member 20 is supported by the front bumper 11 via the connecting member 12.

[0018] An impact load applied to the front bumper 11 is transmitted to the impact absorbing member 20 via the connecting member 12. Therefore, the connecting member 12 is located on the input side of the impact load with respect to the impact absorbing member 20. Therefore, the connecting member 12 located on the input side of the impact load is connected to the impact absorbing member 20. Then, the impact absorbing member 20 absorbs impact energy when it receives the impact load via the connecting member 12.

[0019] <Connection member 12> As shown in Figs. 1 and 2, the connection member 12 is made of a metal material. The connection member 12 is formed of, for example, iron. The connection member 12 has a plate-shaped end wall 12a and a cylindrical peripheral wall 12b. The peripheral wall 12b extends cylindrically from the outer periphery of the end wall 12a. The connection member 12 is supported by the front bumper 11 by joining a surface of the end wall 12a opposite to the peripheral wall 12b to the front bumper 11. The connection member 12 is connected to the impact absorbing member 20 by joining the peripheral wall 12b to the impact absorbing member 20. The axial direction of the peripheral wall 12b coincides with the front-rear direction of the vehicle 10.

[0020] <Impact absorbing member 20> As shown in Fig. 2, the impact absorbing member 20 has a fiber structure 21. The fiber structure 21 is cylindrical. The impact absorbing member 20 is formed by combining the fiber structure 21 with a matrix material 22. For example, an epoxy resin, which is a thermosetting resin, is used as the matrix material 22. The impact absorbing member 20 is a fiber reinforced composite material. In Fig. 2, the matrix material 22 is indicated by dot hatching.

[0021] The textile structure 21 has a plurality of warp yarns 31 and a plurality of weft yarns 32. The warp yarns 31 are first yarns whose first main yarn axis direction L1 extends linearly. The first main yarn axis direction L1 is the axial direction of the textile structure 21. The weft yarns 32 are second yarns whose second main yarn axis direction L2 extends in a direction intersecting with the warp yarns 31. The second main yarn axis direction L2 is the circumferential direction of the textile structure 21.

[0022] The warp yarns 31 and the weft yarns 32 are fiber bundles formed by bundling reinforcing fibers. As the reinforcing fibers, organic fibers or inorganic fibers may be used, or different types of organic fibers, different types of inorganic fibers, or mixed fibers in which organic fibers and inorganic fibers are mixed may be used. Examples of the organic fibers include aramid fibers, poly-p-phenylene benzobisoxazole fibers, and ultra-high molecular weight polyethylene fibers, while examples of the inorganic fibers include carbon fibers, glass fibers, and ceramic fibers.

[0023] As shown in Fig. 3, the fiber structure 21 has a plurality of warp layers 41 and a plurality of weft layers 42. The warp layer 41 is formed by arranging a plurality of warp threads 31 side by side in the second main thread axis direction L2. Therefore, the warp layer 41 is a first thread layer formed by the warp threads 31, which are first threads. The weft layer 42 is formed by arranging a plurality of weft threads 32 side by side in the first main thread axis direction L1. Therefore, the weft layer 42 is a second thread layer formed by the weft threads 32, which are second threads.

[0024] The fiber structure 21 is a multi-layered fabric in which a plurality of warp layers 41 and a plurality of weft layers 42 are bound in a stacked state. In the following description, the "stacking direction of the warp layers 41 and the weft layers 42" may be simply referred to as the "stacking direction Z". The "stacking direction of the warp layers 41 and the weft layers 42" refers to the direction in which the warp layers 41 and the weft layers 42 are stacked. The stacking direction Z is also the thickness direction of the impact absorbing member 20.

[0025] The outermost layers located at both ends of the stacking direction Z in the fiber structure 21 are weft layers 42. The fiber structure 21 is stacked in the order of weft layers 42 and warp layers 41 from both ends of the stacking direction Z toward the center of the stacking direction Z. Then, in the center of the stacking direction Z in the fiber structure 21, the weft layers 42 are stacked adjacent to each other in the stacking direction Z. Therefore, the multiple warp layers 41 and the multiple weft layers 42 are arranged symmetrically in the stacking direction Z with respect to the center of the stacking direction Z.

[0026] 3 and 4, the fiber structure 21 has a general portion 23, a first slit forming portion 24, and a second slit forming portion 25. Therefore, the impact absorbing member 20 includes the general portion 23, the first slit forming portion 24, and the second slit forming portion 25.

[0027] The fiber structure 21 has a plurality of restraining yarns 26. The plurality of restraining yarns 26 are aligned in the second yarn main axis direction L2. Each restraining yarn 26 is a fiber bundle of reinforcing fibers. As the reinforcing fibers, organic fibers or inorganic fibers may be used, or different types of organic fibers, different types of inorganic fibers, or mixed fibers in which organic fibers and inorganic fibers are mixed may be used. The plurality of restraining yarns 26 are aligned approximately parallel to each warp yarn 31.

[0028] In most of the fiber structure 21, each of the restraining yarns 26 is folded back so as to pass through the outer surface of the weft 32 of the weft layer 42 located at one end of the stacking direction Z. Then, each of the restraining yarns 26 penetrates the fiber structure 21 in the stacking direction Z and is folded back so as to pass through the outer surface of the weft 32 of the weft layer 42 located at the other end of the stacking direction Z. Thus, in most of the fiber structure 21, each of the restraining yarns 26 is engaged with each of the wefts 32 of the weft layers 42 located at both ends of the stacking direction Z. Therefore, in most of the fiber structure 21, all of the warp layers 41 and weft layers 42 are restrained in the stacking direction Z by the multiple restraining yarns 26. In the fiber structure 21, the portion where all of the warp layers 41 and weft layers 42 are restrained in the stacking direction Z by the multiple restraining yarns 26 is the general portion 23. In this way, the general portion 23 is formed by restraining all of the warp layers 41 and weft layers 42 in the stacking direction Z by the multiple restraining yarns 26.

[0029] In the portion of the fiber structure 21 excluding the general portion 23, at the center of the stacking direction Z of the fiber structure 21, the warp layer 41 and the weft layer 42 are restrained in the stacking direction Z by a plurality of restraining yarns 26 with the weft layers 42 adjacent to each other in the stacking direction Z spaced apart in the stacking direction Z. The portion of the fiber structure 21 where the warp layer 41 and the weft layer 42 existing from the center of the stacking direction Z to one end of the stacking direction Z are restrained in the stacking direction Z by the plurality of restraining yarns 26 is the first slit forming portion 24. The portion of the fiber structure 21 where the warp layer 41 and the weft layer 42 existing from the center of the stacking direction Z to the other end of the stacking direction Z are restrained in the stacking direction Z by the plurality of restraining yarns 26 is the second slit forming portion 25.

[0030] The first slit forming portion 24 and the second slit forming portion 25 branch off from the general portion 23 to both sides in the stacking direction Z and overlap in the stacking direction Z. The first slit forming portion 24 and the second slit forming portion 25 branch off from the general portion 23 to both sides in the stacking direction Z at the center of the stacking direction Z in the fiber structure 21 by separating adjacent weft layers 42 in the stacking direction Z in the stacking direction Z.

[0031] The first slit forming portion 24 is a portion excluding the general portion 23, and is formed by constraining the warp layer 41 and the weft layer 42 present in the fiber structure 21 from the center of the stacking direction Z to one end of the stacking direction Z by a plurality of constraining yarns 26 in the stacking direction Z. Each of the constraining yarns 26 constraining the warp layer 41 and the weft layer 42 constituting the first slit forming portion 24 engages with the weft yarns 32 of the weft layer 42 located at both ends of the stacking direction Z of the first slit forming portion 24. Each of the constraining yarns 26 constraining the warp layer 41 and the weft layer 42 constituting the first slit forming portion 24 is continuous with the constraining yarns 26 constraining the warp layer 41 and the weft layer 42 constituting the general portion 23.

[0032] The second slit forming portion 25 is a portion excluding the general portion 23, and is formed by constraining the warp layer 41 and the weft layer 42 existing from the center of the stacking direction Z of the fiber structure 21 to the other end of the stacking direction Z by a plurality of constraining yarns 26 in the stacking direction Z. Each of the constraining yarns 26 constraining the warp layer 41 and the weft layer 42 constituting the second slit forming portion 25 engages with the weft 32 of the weft layer 42 located at both ends of the stacking direction Z of the second slit forming portion 25. Each of the constraining yarns 26 constraining the warp layer 41 and the weft layer 42 constituting the second slit forming portion 25 is continuous with the constraining yarn 26 constraining the warp layer 41 and the weft layer 42 constituting the general portion 23. In this way, the fiber structure 21 of this embodiment is a multilayer fabric in which a plurality of warp layers 41 and a plurality of weft layers 42 are stacked and constrained by a plurality of constraining yarns 26.

[0033] The first slit forming portion 24 and the second slit forming portion 25 are not restrained by the restraining thread 26. Since the first slit forming portion 24 and the second slit forming portion 25 are not restrained from each other in the stacking direction Z, a slit 27 is formed between the first slit forming portion 24 and the second slit forming portion 25. The connecting member 12 is inserted into the slit 27. Specifically, the peripheral wall 12b of the connecting member 12 is inserted into the slit 27. Therefore, the connecting member 12 made of a metallic material is inserted into the slit 27.

[0034] 4, the first slit formation portion 24 is located outside the second slit formation portion 25. The first slit formation portion 24 overlaps with the general portion 23 in the axial direction of the fiber structure 21. The second slit formation portion 25 does not overlap with the general portion 23 in the axial direction of the fiber structure 21, and protrudes inward from the inner circumferential surface 23a of the general portion 23.

[0035] 1, in a state where the connecting member 12 inserted into the slit 27 is sandwiched between the first slit forming portion 24 and the second slit forming portion 25, the first slit forming portion 24 and the second slit forming portion 25 are each joined to the connecting member 12. In this way, the shock absorbing member 20 is integrated with the connecting member 12. Specifically, in a state where the peripheral wall 12b of the connecting member 12 is inserted into the slit 27, the fiber structure 21 is impregnated with the matrix material 22. Then, the matrix material 22 hardens, thereby integrating the shock absorbing member 20 and the connecting member 12. In this way, the shock absorbing member 20 and the connecting member 12 are integrated by insert molding.

[0036] The thickness direction of the peripheral wall 12b coincides with the stacking direction Z. The impact absorbing member 20 is joined to the peripheral wall 12b of the connecting member 12 from both sides in the stacking direction Z of the warp layer 41 and the weft layer 42. The axial direction of the peripheral wall 12b is the front-rear direction of the vehicle 10, which is the direction in which the impact load is input. Therefore, the connecting member 12 located on the input side of the impact load is connected to the impact absorbing member 20 so that the impact load is input from a direction perpendicular to the stacking direction Z.

[0037] [Operation of the embodiment] Next, the operation of this embodiment will be described. The impact absorbing member 20 is joined to the connecting member 12 from both sides in the lamination direction Z of the warp layer 41 and the weft layer 42. Therefore, for example, compared with a case where the impact absorbing member 20 is joined to the connecting member 12 from one side in the lamination direction Z of the warp layer 41 and the weft layer 42, the joint area between the impact absorbing member 20 and the connecting member 12 is increased. As a result, the connection strength between the impact absorbing member 20 and the connecting member 12 is increased.

[0038] As shown in FIG. 5, when the connection member 12 located on the input side of the impact load receives an impact load, the impact absorbing member 20 receives the impact load through the connection member 12 from a direction perpendicular to the stacking direction Z. At this time, since the first slit forming portion 24 overlaps with the general portion 23 in the axial direction of the fiber structure 21, when the impact absorbing member 20 receives an impact load through the connection member 12, the first slit forming portion 24 is easily supported by the general portion 23. On the other hand, since the second slit forming portion 25 does not overlap with the general portion 23 in the axial direction of the fiber structure 21, when the impact absorbing member 20 receives an impact load through the connection member 12, the second slit forming portion 25 is not easily supported by the general portion 23. Therefore, when the impact absorbing member 20 receives an impact load through the connection member 12, the second slit forming portion 25 is likely to be the starting point of destruction. In this way, since the connection member 12 is inserted into the slit 27, when the impact absorbing member 20 receives an impact load through the connection member 12, the second slit forming portion 25 can be the starting point of destruction. Therefore, the destruction of the impact absorbing member 20 can be easily and stably carried out.

[0039] [Effects of the embodiment] The above embodiment can provide the following effects. (1) In a state where the connecting member 12 inserted into the slit 27 is sandwiched between the first slit forming portion 24 and the second slit forming portion 25, the first slit forming portion 24 and the second slit forming portion 25 are each joined to the connecting member 12. As a result, the shock absorbing member 20 is integrated with the connecting member 12. Therefore, the shock absorbing member 20 is joined to the connecting member 12 from both sides in the lamination direction Z of the warp layer 41 and the weft layer 42. Therefore, compared to a case where the shock absorbing member 20 is joined to the connecting member 12 from one side in the lamination direction Z of the warp layer 41 and the weft layer 42, for example, the joining area between the shock absorbing member 20 and the connecting member 12 is increased. As a result, the connection strength between the shock absorbing member 20 and the connecting member 12 can be increased.

[0040] When the connecting member 12 located on the input side of the impact load receives the impact load, the impact absorbing member 20 receives the impact load through the connecting member 12 from a direction perpendicular to the lamination direction Z of the warp layer 41 and the weft layer 42. At this time, since the connecting member 12 is inserted into the slit 27, when the impact absorbing member 20 receives the impact load through the connecting member 12, the second slit forming portion 25 can become the starting point of destruction. Therefore, destruction of the impact absorbing member 20 is likely to occur stably.

[0041] Here, for example, consider a configuration in which the connecting member 12 is connected to the shock absorbing member 20 having only the general portion 23. In this case, in order to ensure that the shock absorbing member 20 is destroyed stably, it is necessary to form in advance by machining a portion in the shock absorbing member 20 that will be the destruction starting point when the shock absorbing member 20 receives an impact load via the connecting member 12. Therefore, a separate process is required to form the portion in the shock absorbing member 20 that will be the destruction starting point, which poses a problem of increased manufacturing costs.

[0042] On the other hand, when manufacturing the shock absorbing member 20 having the general portion 23, the first slit forming portion 24, and the second slit forming portion 25, the weaving structure is merely changed in the weaving process of the multilayer fabric. Therefore, for example, the manufacturing cost is almost the same as that of the weaving process of the multilayer fabric when manufacturing the shock absorbing member 20 having only the general portion 23. Therefore, a separate process for forming a portion that becomes the starting point of destruction in the shock absorbing member 20 is not required. Therefore, in the shock absorbing member 20, a configuration that makes it easy to cause destruction stably when an impact load is applied through the connecting member 12 can be realized at low cost. As described above, in the shock absorbing member 20, a configuration that increases the connection strength with the connecting member 12 and makes it easy to cause destruction stably when an impact load is applied through the connecting member 12 can be realized at low cost.

[0043] (2) Since the first slit forming portion 24 overlaps with the general portion 23 in the axial direction of the fiber structure 21, the first slit forming portion 24 is easily supported by the general portion 23 when the shock absorbing member 20 receives an impact load via the connecting member 12. On the other hand, since the second slit forming portion 25 does not overlap with the general portion 23 in the axial direction of the fiber structure 21, the second slit forming portion 25 is less likely to be supported by the general portion 23 when the shock absorbing member 20 receives an impact load via the connecting member 12. Therefore, when the shock absorbing member 20 receives an impact load via the connecting member 12, the second slit forming portion 25 is likely to become the starting point of destruction. Therefore, destruction of the shock absorbing member 20 is more likely to occur stably.

[0044] (3) The connecting member 12 made of a metallic material is inserted into the slit 27. In this way, even if the connecting member 12 is made of a metallic material, the connection strength between the impact absorbing member 20 and the connecting member 12 can be increased.

[0045] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0046] In the embodiment, for example, the first slit formation portion 24 may not overlap the general portion 23 in the axial direction of the fiber structure 21, and may protrude outward beyond the outer circumferential surface of the general portion 23. The second slit formation portion 25 may overlap the general portion 23 in the axial direction of the fiber structure 21.

[0047] According to this, since the second slit forming portion 25 overlaps with the general portion 23 in the axial direction of the fiber structure 21, it is easily supported by the general portion 23 when the shock absorbing member 20 receives an impact load via the connecting member 12. On the other hand, since the first slit forming portion 24 does not overlap with the general portion 23 in the axial direction of the fiber structure 21, it is difficult to be supported by the general portion 23 when the shock absorbing member 20 receives an impact load via the connecting member 12. Therefore, when the shock absorbing member 20 receives an impact load via the connecting member 12, the first slit forming portion 24 is likely to become the starting point of destruction. Therefore, destruction of the shock absorbing member 20 is likely to occur stably.

[0048] In the embodiment, for example, a portion of the first slit forming portion 24 may not overlap with the general portion 23 in the axial direction of the fiber structure 21 and may protrude outward from the outer circumferential surface of the general portion 23. Furthermore, for example, a portion of the second slit forming portion 25 may not overlap with the general portion 23 in the axial direction of the fiber structure 21 and may protrude inward from the inner circumferential surface 23a of the general portion 23.

[0049] According to this, when the shock absorbing member 20 receives an impact load via the connecting member 12, a part of the first slit forming portion 24 and a part of the second slit forming portion 25 are unlikely to be supported by the general portion 23. Therefore, when the shock absorbing member 20 receives an impact load via the connecting member 12, both the first slit forming portion 24 and the second slit forming portion 25 are likely to become the starting points of destruction. Therefore, destruction of the shock absorbing member 20 is likely to occur stably.

[0050] In this way, since the connecting member 12 is inserted into the slit 27, when the shock absorbing member 20 receives an impact load through the connecting member 12, at least one of the first slit forming portion 24 and the second slit forming portion 25 can become the starting point of destruction. Therefore, destruction of the shock absorbing member 20 can be stably performed.

[0051] In the embodiment, the impact absorbing member 20 and the connecting member 12 are integrated by insert molding, but this is not limited thereto. For example, before inserting the peripheral wall 12b of the connecting member 12 into the slit 27, the fiber structure 21 is impregnated with the matrix material 22 and the matrix material 22 is cured to form the impact absorbing member 20. Thereafter, the peripheral wall 12b of the connecting member 12 may be inserted into the slit 27, and the connecting member 12 and the first slit forming portion 24 and the connecting member 12 and the second slit forming portion 25 may be bonded with an adhesive. In this manner, the first slit forming portion 24 and the second slit forming portion 25 may be joined to the connecting member 12, respectively, so that the impact absorbing member 20 is integrated with the connecting member 12.

[0052] In the above-described embodiment, the connection member 12 is not limited to being made of a metal material and may be made of other materials. In the embodiment, the multiple warp layers 41 and the multiple weft layers 42 are arranged symmetrically in the stacking direction Z with respect to the center of the stacking direction Z, but this is not limited to this, and the stacking order of the multiple warp layers 41 and the multiple weft layers 42 is not particularly limited.

[0053] In the above embodiment, the fiber structure 21 has a cylindrical shape. However, the shape is not limited to this. For example, the fiber structure 21 may have a rectangular or triangular cylindrical shape. In the embodiment, the fiber structure 21 does not have to be cylindrical, and may have an open cross-sectional shape, such as a U-shape or a hat-shape.

[0054] In the embodiment, the textile structure 21 does not have a plurality of restraining yarns 26, and for example, the warp yarns 31 may be used as restraining yarns. Thus, the textile structure 21 may be a multilayer fabric in which a plurality of warp layers 41 and a plurality of weft layers 42 are restrained by a plurality of warp yarns 31 in a stacked state. In short, the textile structure 21 may be any multilayer fabric in which a plurality of warp layers 41 and a plurality of weft layers 42 are restrained in a stacked state.

[0055] In some embodiments, the matrix material 22 may be, for example, ceramic. In the above-mentioned embodiment, the impact absorbing member 20 may be disposed, for example, between the rear bumper and the rear side member. In other words, the position at which the impact absorbing member 20 is disposed on the vehicle 10 is not particularly limited.

[0056] In the above-described embodiment, the impact absorbing member 20 may be used in a device other than the vehicle 10 . [Explanation of symbols]

[0057] 12...connecting member, 20...shock absorbing member, 21...fibrous structure, 22...matrix material, 23...general part, 24...first slit forming part, 25...second slit forming part, 27...slit, 31...warp yarn which is first yarn, 32...weft yarn which is second yarn, 41...warp layer which is first yarn layer, 42...weft layer which is second yarn layer.

Claims

1. The fiber structure is a multi-layered fabric in which a first yarn layer formed by a first yarn and a second yarn layer formed by a second yarn intersecting the first yarn are bound in a stacked state, and a matrix material is compounded with the fiber structure; a connecting member located on an input side of an impact load is connected so that the impact load is input from a direction perpendicular to a lamination direction of the first yarn layer and the second yarn layer, and the impact absorbing member absorbs impact energy when the impact load is received via the connecting member, a general portion in which all of the first yarn layer and the second yarn layer are constrained in the lamination direction; a first slit forming portion and a second slit forming portion branched from the general portion to both sides in the stacking direction and overlapping each other in the stacking direction, Since the first slit formation portion and the second slit formation portion are not constrained from each other in the stacking direction, a slit into which the connection member is inserted is formed between the first slit formation portion and the second slit formation portion, An impact absorbing member characterized in that the connecting member inserted into the slit is sandwiched between the first slit forming portion and the second slit forming portion, and the first slit forming portion and the second slit forming portion are each joined to the connecting member, thereby integrating the connecting member with the connecting member.

2. The fiber structure is cylindrical, The first slit forming portion is located outside the second slit forming portion, the first slit formation portion overlaps with the general portion in the axial direction of the fiber structure, The impact absorbing member according to claim 1 , wherein the second slit forming portion does not overlap with the general portion in the axial direction of the fiber structure and protrudes inward from the general portion.

3. 3. The impact absorbing member according to claim 1, wherein the connecting member made of a metallic material is inserted into the slit.

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