Vehicle impact absorbing structure

Abstract

The present invention provides a vehicle shock-absorbing structure that can achieve the characteristic of maintaining a nearly constant load when an impact is applied. [Solution] A vehicle shock-absorbing structure equipped with a shock-absorbing section, wherein the shock-absorbing section has a rib section, a rib hollow section surrounded only by the rib section, and a peripheral hollow section surrounded by the peripheral section and the rib section inside a peripheral section forming an outer shell, the rib hollow sections are arranged in a plurality in a direction perpendicular to the direction in which the shock load is applied, the peripheral section has a top surface having a surface to which the shock load is applied and a bottom surface having a surface opposite to the top surface, and the number of rib hollow sections configured such that the height of the center of gravity of the rib hollow section from the bottom surface is different from the height of the center of gravity of at least one adjacent rib hollow section or peripheral hollow section from the bottom surface in a direction perpendicular to the direction in which the shock load is applied is 50% or more of the total number of rib hollow sections.

Description

Technical Field

[0001] The present invention relates to a shock absorption structure for vehicles, and particularly to a shock absorption structure for vehicles improved to advantageously absorb input shock energy while effectively achieving weight reduction.

Background Art

[0002] In preparation for contact between a person and a vehicle, particularly an automobile, and frontal, side, and rear collisions between vehicles, it is desirable to provide shock absorption structures at various parts of the vehicle. In such a shock absorption structure for a vehicle, it is required to sufficiently absorb energy. On the other hand, if the impact load exerted on a pedestrian or a passenger is too large, there is a risk of causing injury to the person. Therefore, in order to ensure the energy absorption amount while suppressing the impact load below a certain load, it is desirable to keep the load substantially constant (make the load-displacement diagram during collision a rectangular wave).

[0003] Under such circumstances, there is proposed an energy absorption member including an upper horizontal plate portion and a lower horizontal plate portion spaced apart in the vertical direction, an outer vehicle side vertical plate portion and an inner vehicle side vertical plate portion spaced apart in the vehicle width direction, and a plurality of intermediate vertical plate portions disposed between the outer vehicle side vertical plate portion and the inner vehicle side vertical plate portion, the internal space being divided into a plurality of compartments by the intermediate vertical plate portions, the upper horizontal plate portion and the lower horizontal plate portion including a plurality of compartment forming portions that are portions between adjacent intermediate vertical plate portions in the vehicle width direction, and at least one of the compartment forming portions including a portion where the intermediate portion in the vehicle width direction protrudes to one side in the vertical direction from both ends in the vehicle width direction (Patent Document 1).

[0004] Alternatively, an energy absorption device has been proposed that includes a composite or metal component having three or more walls forming a component channel having a longitudinal length, and a polymer component, the polymer component having two or more walls defining a honeycomb tube and having a honeycomb structure supported within the component channel, the honeycomb tubes being stacked laterally along the longitudinal length of the component channel, the ends of the honeycomb tubes being adjacent to the composite or metal component, and the composite or metal component or the polymer component having a bending stiffness greater than the bending stiffness of the honeycomb structure (Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-25058 [Patent Document 2] Special Publication No. 2022-535402 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, as mentioned above, it is currently difficult to keep the load approximately constant during a collision in order to ensure sufficient energy absorption while keeping the impact load below a certain level.

[0007] For example, Patent Document 1 describes an energy absorbing member comprising two horizontal plate sections extending in a first direction and a second direction perpendicular to the first direction, and spaced apart from each other in a third direction perpendicular to the first and second directions, and three or more vertical plate sections extending in a first direction and a third direction, spaced apart from each other in the second direction, with each of the ends in the third direction joined to each of the two horizontal plate sections, wherein the internal space is divided into a plurality of compartments aligned in the second direction by the vertical plate sections, and the two horizontal plate sections are the compartments that are the parts between adjacent vertical plate sections in the second direction. A structure has been proposed in which the forming portion comprises multiple forming portions, and at least one of the multiple forming portions has a portion in which, when viewed from the first direction, the intermediate portion in the second direction protrudes to one side in the third direction more than the ends in the second direction. As a result, when a compressive load in the second direction is applied to the forming portion, the forming portion with the protruding portion is induced to buckle in a manner that protrudes to the aforementioned one side in the third direction. Therefore, by causing the forming portion to buckle in a desired direction, it is possible to prevent or suppress, for example, the buckled forming portion from coming into contact with other members or other forming portions. However, although the internal space of this energy absorbing member is divided into multiple compartments aligned in the second direction, it is not divided in the third direction. Therefore, when a load is applied from the second direction, the load starts to increase, but when the buckling of the lateral plate portion begins, the deformation progresses rapidly, causing the load to drop rapidly. Therefore, each time the lateral plate buckles after the start of load transmission to each section, a significant vertical movement of the load occurs sequentially. In this structure, it is not possible to expect any effect in suppressing load changes in order to keep the impact load below a certain load during a collision while ensuring energy absorption.

[0008] Patent Document 2 describes an energy absorption device comprising a composite or metal component having three or more walls forming a component channel with a longitudinal length, and a polymer component having a honeycomb structure with multiple polymer walls, the multiple polymer walls defining honeycomb tubes. The polymer component is supported within the component channel, the honeycomb tubes are stacked laterally along the longitudinal length of the component channel, and the ends of the honeycomb tubes face the composite or metal component. Furthermore, the composite or metal component, or the polymer component, has a bending stiffness greater than the bending stiffness of the honeycomb structure, providing back support for the gradual crushing of the honeycomb tubes during a side pole collision with a vehicle. Previously, attempts have been made to provide metal energy-absorbing inserts for automobile vehicles that absorb most of the collision energy during an impact. However, while metal energy-absorbing inserts have good energy absorption properties, they can be relatively heavy in relation to the polymer honeycomb structure, so the polymer honeycomb structure is considered relatively lightweight. However, polymer honeycomb structures may lack sufficient bending stiffness compared to metal energy-absorbing inserts, and the polymer honeycomb structure on the rear support side collapsed, making it insufficient to provide the bending stiffness required to absorb the energy associated with the collision. Therefore, this energy absorption device is designed to exhibit sufficient energy absorption performance when combined with metal components that have high bending stiffness. However, since the longitudinal direction of the honeycomb tubes in this honeycomb structure faces the collision side, the load at the moment of impact is high, allowing for large energy absorption. However, once buckling of the honeycomb tubes occurs, there is no longer a point to support the load, so the load drops sharply. Therefore, this energy absorption device cannot be said to be a structure aimed at keeping the load during energy absorption approximately constant, and it may not actually be possible to achieve this.

[0009] As described above, conventional technology has the problem that it is not possible to obtain a characteristic in which the load remains approximately constant while ensuring energy absorption properties during the deformation process of the structure.

[0010] Therefore, the object of the present invention is to provide a vehicle shock-absorbing structure that can obtain the characteristic of having a substantially constant load when an impact is applied. [Means for solving the problem]

[0011] To solve the above problems, the present invention provides a vehicle impact absorbing structure equipped with an impact absorbing section, wherein the impact absorbing section has a rib section, a rib hollow section surrounded only by the rib section, and a peripheral hollow section surrounded by the peripheral section and the rib section inside a peripheral section forming an outer shell, the rib hollow sections are arranged in a plurality in a direction perpendicular to the direction in which the impact load is applied, the peripheral section has a top surface having a surface to which the impact load is applied and a bottom surface having a surface opposite to the top surface, and the number of rib hollow sections configured such that the height of the center of gravity of the rib hollow section from the bottom surface is different from the height of the center of gravity of at least one adjacent rib hollow section or peripheral hollow section from the bottom surface in a direction perpendicular to the direction in which the impact load is applied is 50% or more of the total number of rib hollow sections.

[0012] In the vehicle impact absorbing structure according to the present invention, it is preferable that the heights from the bottom surface of the center of gravity of adjacent rib hollow portions or peripheral hollow portions in a direction perpendicular to the direction in which the impact load is applied are configured to be three or more different heights.

[0013] Furthermore, in the vehicle impact absorbing structure according to the present invention as described above, it is preferable that the shape of the rib hollow portion or the surrounding hollow portion is rectangular, but the shape of the rib hollow portion or the surrounding hollow portion may be polygonal.

[0014] Furthermore, the shape of the rib hollow portion or the surrounding hollow portion may be circular.

[0015] Furthermore, the material constituting one or both of the peripheral portion and the rib portion in the present invention is not particularly limited and can be made of, for example, a thermoplastic resin or a thermosetting resin. From the viewpoint of ease of molding, a thermoplastic resin is more preferable.

[0016] Alternatively, the material constituting one or both of the peripheral portion and the rib portion may be composed of a thermoplastic resin composition or a thermosetting resin composition. In this case, it is particularly preferable that the resin composition is composed of a fiber-reinforced resin composition containing at least one fiber-reinforcement material, such as glass fibers, carbon fibers, or metal fibers. [Effects of the Invention]

[0017] According to the vehicle impact absorption structure of the present invention, it is possible to obtain load characteristics in which the load remains substantially constant when an impact is applied, thereby enabling highly efficient impact energy absorption characteristics while suppressing the maximum load. [Brief explanation of the drawing]

[0018] [Figure 1] The image shows a vehicle impact absorbing structure according to one embodiment of the present invention, where (A) is a schematic perspective view, (B) is a side view, and (C) is a front view. [Figure 2] This is a schematic diagram of the front of an automobile showing an example of the installation of the vehicle impact absorbing structure according to the present invention onto an automobile. [Figure 3] Figure 2 is an enlarged view of the vehicle impact absorbing structure when installed. [Figure 4] Figure 1 is a schematic explanatory diagram showing the state of a drop weight test on a vehicle impact absorption structure, where (A) shows the state before the weight contacts the top surface of the structure, (B) shows the state when the weight contacts the top surface, (C) shows the state when the top of the structure is deformed and fracture has begun, and (D) shows the state when the deformation of the structure and fracture of the top have progressed. [Figure 5] As a comparative example, a conventional vehicle impact absorbing structure is shown in which the rib thickness of the rib section is uniform, and the ribs are arranged in a grid pattern at equal intervals, so that the height from the bottom surface of the center of gravity of adjacent rib hollow sections or surrounding hollow sections in a direction perpendicular to the direction in which the impact load is applied is the same. (A) is a schematic perspective view, (B) is a side view, and (C) is a front view. [Figure 6]It is an explanatory view schematically showing the state of a drop weight test on the vehicle impact absorbing structure shown in FIG. 5, where (A) shows the state before the weight contacts the top surface of the structure, (B) shows the state where the weight contacts the top surface, (C) shows the state where the top of the structure is deformed and destruction starts, and (D) shows the state where the deformation of the structure and the destruction of the top progress, respectively. [Figure 7] It is a graph schematically showing the load - displacement characteristics when a drop weight test is performed on each of the vehicle impact absorbing structures shown in FIG. 1 and the vehicle impact absorbing structure shown in FIG. 5. [Figure 8] It is a schematic perspective view of a vehicle impact absorbing structure according to an embodiment of the present invention, in which the height from the bottom surface of the center of gravity of the rib hollow part or the peripheral hollow part adjacent in the direction orthogonal to the direction in which the impact load is input is composed of three or more different heights. [Figure 9] It is a schematic perspective view of a vehicle impact absorbing structure in which a part of the ribs of the vehicle impact absorbing structure shown in FIG. 1 is deleted, and the height from the bottom surface of the center of gravity of the rib hollow part or the peripheral hollow part adjacent in the direction orthogonal to the direction in which the impact load of the hollow part is input is composed of three or more different heights. [Figure 10] It is a schematic perspective view of a vehicle impact absorbing structure according to an embodiment of the present invention, in which the shape of the hollow part is composed of a polygon. [Figure 11] It is a schematic perspective view of a vehicle impact absorbing structure according to an embodiment of the present invention, in which the shape of the hollow part is circular.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a vehicle impact absorbing structure according to an embodiment of the present invention. In FIG. 1, 100 indicates a vehicle impact absorbing structure. The vehicle impact absorbing structure 100 is preferably used, for example, at the front part of an automobile body as shown in FIG. 2, so as to absorb the collision energy 200 input during a collision. However, this structure can also be preferably used at the rear part or the side part other than the front part of the vehicle body, and is not limited to being used only at the front part of the automobile body.

[0020] In the case where the vehicle impact absorbing structure 100 shown in Figure 1 is installed at the front of the vehicle, more specifically, as shown in Figure 3, the vehicle impact absorbing structure 100 is connected to other vehicle members 302. In Figure 3, reference numeral 300 indicates collision energy, and reference numeral 301 indicates the bumper.

[0021] The peripheral portion 101 and rib portion 102 that form the outer casing of the vehicle impact absorbing structure 100 in Figure 1 are configured to absorb impact energy 120 by deformation or fracture from the end on the impact load input side when an impact load is applied. In this embodiment, the peripheral portion 101 and rib portion 102 are made of resin, and the peripheral portion 101 has a rib portion 102 inside, a rib hollow portion 103 surrounded only by the rib portion 102, and a peripheral hollow portion 104 surrounded by the peripheral portion 101 and the rib portion 102.

[0022] Furthermore, the rib hollow sections 103 are arranged in a direction perpendicular to the direction in which the impact load 120 is applied, with the surface of the peripheral section 101 to which the impact load 120 is applied being the top surface 105, and the surface opposite to the top surface 105 being the bottom surface 106, and the number of rib hollow sections 103 configured such that the height of the center of gravity of the rib hollow section 103 from the bottom surface 106 is different from the height of the center of gravity of at least one adjacent rib hollow section 103 or peripheral hollow section 104 from the bottom surface 105 in the direction perpendicular to the direction in which the impact load 120 is applied is 50% or more of the total number of rib hollow sections 103. This is because, when an impact load is applied, the peripheral portion 101 and the rib portion 102 deform as the load increases, being pushed outward from the end on the impact load application side, gradually transmitting the load to the rib portion 102. The peripheral portion 101 and the rib portion 102, separated by the rib hollow portion 103 or the rib peripheral portion 104, then break sequentially from the top surface portion 105 side, thereby preventing abrupt load rise and vibration, and enabling efficient energy absorption. Furthermore, it is also possible to combine rib hollow sections 103 configured to have the same height as at least one adjacent rib hollow section 103 or peripheral hollow section 104, with rib hollow sections 103 configured to have the same height as the center of gravity of the surrounding hollow section 103. However, this reduces the effect of preventing abrupt load rise and vibration. Therefore, the number of rib hollow sections 103 configured to have a different height from the center of gravity of at least one adjacent rib hollow section 103 or peripheral hollow section 104 is configured to be 50% or more of the total number of rib hollow sections 103.

[0023] Furthermore, as shown in the vehicle impact absorption structures 800 and 900 in Figures 8 and 9, more preferably, by making the heights of the adjacent rib hollow section 103 or surrounding hollow section 104 from the bottom surface 106 of the center of gravity in a direction perpendicular to the direction in which the impact load 120 is applied to the rib hollow section 103 differ by three or more heights, it becomes possible to cause the rib section 102 to break in stages from the end on the impact load application side, further reducing the abrupt fluctuation of the load, and thus an increase in energy absorption can be expected. Figure 8 shows a schematic perspective view of a vehicle impact absorption structure according to one embodiment of the present invention, in which the heights of the adjacent rib hollow section or surrounding hollow section from the bottom surface of the center of gravity in a direction perpendicular to the direction in which the impact load is applied differ by three or more heights. Figure 9 shows a schematic perspective view of a vehicle impact absorption structure in which some ribs of the vehicle impact absorption structure shown in Figure 1 are removed, and the heights of the adjacent rib hollow section or surrounding hollow section from the bottom surface of the center of gravity in a direction perpendicular to the direction in which the impact load is applied to the hollow section differ by three or more heights.

[0024] Furthermore, it is preferable that the shape of the rib hollow portion 103 or the surrounding hollow portion 104 be rectangular. This is because the direction of the formation structure of the rib portion 102 can be aligned with the direction in which the impact load 120 is applied, and thus it is expected that the impact energy 120 received can be absorbed efficiently. In addition, the design is simplified because the thickness of the rib portion 102 can be kept constant and the rib hollow portion 103 and the surrounding rib portion 104 can be arranged without waste.

[0025] Furthermore, as shown in the vehicle impact absorption structure 1000 in Figure 10, the shape of the rib hollow portion 103 or the surrounding hollow portion 104 may be polygonal. By making it polygonal, the rib portion 102 can be aligned with multiple directions in which the impact load 120 is applied, and thus it is expected to efficiently absorb the impact energy 120 received from various directions.

[0026] Furthermore, as shown in the vehicle impact absorption structure 1100 in Figure 11, the shape of the rib hollow portion 103 or the peripheral hollow portion 104 may be circular. By making it circular, the thickness of the rib portion 102 will not be constant, which will increase the difficulty of design and molding. However, since the rib hollow portion 103 or the peripheral hollow portion 104 can be arranged as densely as possible inside the peripheral portion 101, it is possible to cause fracture to occur gradually from the end on the impact load input side and further reduce sudden fluctuations in load, so it is expected that the amount of energy absorbed will increase.

[0027] The effect of the vehicle impact absorbing structure according to the present invention will be explained based on the results of a drop weight test simulation using the finite element method for the embodiment shown in Figure 1. In this test, the dimensions of the vehicle impact absorbing structure 100 are 40 mm × 123 mm, with a height of 103 mm. The plate thickness of the peripheral portion 101 and the rib portion 102 is 3 mm. In this test, as shown in Figure 4(A), the vehicle impact absorbing structure 100 is erected and placed on a base plate 402 as a fixing surface. A predetermined weight 401 is dropped from above in the direction of the impact energy 400, and the vehicle impact absorbing structure 100 is crushed in the axial direction. The conditions for this drop weight test were a weight of 200 kg and a drop weight height of 2 m. The compressive deformation behavior of the vehicle impact absorbing structure 100 was observed, and the displacement from the start of the compressive deformation of the vehicle impact absorbing structure 100 and the load generated by this compressive deformation were output. The resin used in the vehicle impact-absorbing structure 100 was glass fiber reinforced nylon manufactured by Toray Industries, Inc. (elastic modulus: 6.3 GPa, strength: 225 MPa).

[0028] Regarding the simulation of the drop weight test described above, first, as shown in Figure 6, a comparative example was performed in which the thickness of the peripheral portion 501 and the rib portion 502 were unified to 3 mm so that the weight was approximately the same as that of the vehicle impact absorbing structure 100 of the above embodiment shown in Figure 5, and the ribs were arranged in a grid pattern at equal intervals, and the height from the bottom surface portion 506 of the center of gravity of adjacent rib hollow portions 503 or peripheral hollow portions 504 in a direction perpendicular to the direction in which the impact load is applied was the same. The resin used for the vehicle impact absorbing structure 500 of the comparative example was glass fiber reinforced nylon manufactured by Toray Industries, Inc. (elastic modulus: 6.3 GPa, strength: 225 MPa). Figure 6 shows the state before the weight 401 contacts the top surface 505 of the vehicle impact absorption structure 500 (A), the state when the weight 401 contacts the top surface 505 of the structure 500 (B), the state when the top of the structure 500 is deformed and fracture has begun (C), and the state when the deformation of the structure 500 and fracture of the top have progressed (D). As a result, a load-displacement diagram as shown by the reference numeral 700 in Figure 7 was obtained. The load increases sharply immediately after deformation. At this time, because the height from the bottom surface 506 of the center of gravity of adjacent rib hollow sections 503 or peripheral hollow sections 504 in a direction perpendicular to the direction in which the impact load is applied is the same, fracture of the peripheral section 501 and rib section 502 around the rib hollow section 503 or peripheral hollow section 504 at the same height occurs at once, and because the time when the weight 400 and rib section 502 are no longer in contact is long, the load drops sharply after reaching the peak load. After passing the fracture zone, the weight 400 continues to fall, and as the rib tip of the fractured rib section 502 begins to contact other rib sections 502, the load increases again, and then drops sharply at the moment of fracture, repeating this phenomenon. In this comparative example, the height from the bottom surface 506 of the center of gravity of adjacent rib hollow sections 503 or surrounding hollow sections 504 in a direction perpendicular to the direction in which the impact load is applied is the same, causing the load to fluctuate significantly, and the generated load does not remain approximately constant around the target load.

[0029] Next, a simulation of the vehicle impact absorption structure 100 according to an embodiment of the present invention was performed. Figure 4 shows the state before the weight 401 and the top surface 105 of the vehicle impact absorption structure 100 come into contact (A), the state when the weight 401 comes into contact with the top surface 105 of the structure 100 (B), the state when the top of the structure 100 deforms and fracture begins (C), and the state when the deformation of the structure 100 and fracture of the top surface have progressed (D). As a result, a load-displacement diagram as shown by reference numeral 701 in Figure 7 was obtained. Immediately after deformation, the peripheral portion 101 and the rib portion 102 on the impact load input side support the load and the load increases. As the deformation progresses, fracture occurs in the rib portion 102 around the peripheral hollow portion 104 close to the top surface 105. At this time, there is a period when the contact between the weight 401 and the rib portion 102 is lost, and the load decreases after reaching the peak load. However, because the height of the center of gravity of the rib hollow section 103 from the bottom surface 106 is configured to be different from the height of the center of gravity of the adjacent rib hollow section 103 or surrounding hollow section 104 from the bottom surface 106 in a direction perpendicular to the direction in which the impact load 400 is applied, the timing at which contact between the weight 401 and the rib section 102 is lost can be minimized, thereby preventing a sudden drop in load after reaching the peak load. After passing the fracture zone, as the weight 400 falls further and the tip of the fractured rib section 102 begins to contact the rib sections 102 of the lower rib hollow sections 103 and surrounding hollow sections 104, the load will rise again, but because a similar structure is provided, a sudden increase in load above the target load can also be suppressed. This is evident from the changes in the load-displacement diagrams for 700 and 701 in Figure 7. It is clear that 701, which moves around the target load, exhibits a greater effect than 700 in that the load remains approximately constant while maintaining energy absorption characteristics during the deformation process.

[0030] Here, as a method to evaluate the effect of making the load approximately constant in more detail, the amount of excess energy is compared by looking at the load-displacement diagram, comparing the integral of the difference between the load that has reached or exceeded the target load and the target load, and the amount of displacement. In Figure 7, the area of ​​region 710 above the target load in the load-displacement diagram 700 of the comparative example represents the excess energy of the comparative example, and the area of ​​region 711 above the target load in the load-displacement diagram 701 of the embodiment of the present invention represents the excess energy in the embodiment of the present invention. When the target load is 35kN, the amount of excess energy in area 710 of the comparative example is 1320J, while the amount of excess energy in the embodiment of the present invention is 520J, showing an effect of reducing the load by approximately 60%.

[0031] Furthermore, it is preferable that the vehicle shock-absorbing structure 100 is composed of a thermoplastic resin, a thermosetting resin, a thermoplastic resin composition, or a thermosetting resin composition, as this provides better weight reduction and shock absorption. Examples of thermoplastic resins include polyamide, polycarbonate, polyarylene sulfides such as polyoxymethylene and polyphenylene sulfide, polyesters such as polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polystyrene, polymethyl methacrylate, acrylonitrile / styrene copolymer, and acrylonitrile / butadiene / styrene copolymer. Two or more of these may be included. Among these, polyamide, polybutylene terephthalate, and polycarbonate are preferred from the viewpoint of mechanical properties and heat resistance. Other examples of polyamides include PA6 (also known as polycaproamide, polycaprolactam, or poly-ε-caprolactam), PA26 (polyethylene adipamide), PA46 (polytetramethylene adipamide), PA66 (polyhexamethylene adipamide), PA69 (polyhexamethylene azeramide), PA610 (polyhexamethylene sevacamide), PA611 (polyhexamethylene undecamide), PA612 (polyhexamethylene dodecamide), PA11 (polyundecamide), PA12 (polydodecamamide), and PA121. Examples include 2 (polydodecamethylene dodecamide), PA6T (polyhexamethylene terephthalamide), PA6I (polyhexamethylene isophthalamide), PA912 (polynonameethylene dodecamide), PA1012 (polydecamethylene dodecamide), PA9T (polynonameethylene terephthalamide), PA10T (polydecamethylene terephthalamide), PA11T (polyundecamethylene terephthalamide), PA12T (polydodecamethylene terephthalamide), and polyamide MXD6 (polymetaxylylene adipamide). Two or more of these may be included.

[0032] Furthermore, it is even more preferable that the vehicle impact-absorbing structure 100 be made of a fiber-reinforced resin composition obtained by mixing a thermoplastic resin or thermosetting resin with at least one fiber-reinforcement material such as glass fiber, carbon fiber, or metal fiber, as this can effectively handle situations such as high target loads. [Industrial applicability]

[0033] The vehicle impact-absorbing structure of the present invention can be applied to any part of a vehicle where impact absorption is desired, and is particularly suitable for application to the rear and side parts of the automobile body, in addition to the front part. [Explanation of symbols]

[0034] 100: Impact-absorbing structure for vehicles 101, 501: Peripheral area 102, 502: Rib section 103, 503: Rib hollow section 104, 504: Peripheral hollow section 105, 505: Top section 106, 506: Bottom part 200, 300: Collision energy 301: Bumper 302: Other vehicle components 400: Impact energy 401: Weight 402: Surface plate as a fixed surface 500: Vehicle impact absorbing structure related to comparative example 700: Load-displacement diagram in comparative example 701: Load-displacement diagram in an embodiment of the present invention 710: Region exceeding the target load in the comparative example 711: Region above the target load in the embodiment of the present invention 800, 900, 1000, 1100: Impact absorbing structures for vehicles

Claims

1. An impact-absorbing structure for a vehicle, comprising an impact-absorbing section, wherein the impact-absorbing section has, inside a peripheral section forming an outer shell, a rib section, a rib hollow section surrounded only by the rib section, and a peripheral hollow section surrounded by the peripheral section and the rib section, wherein a plurality of rib hollow sections are arranged in a direction perpendicular to the direction in which the impact load is applied, and the peripheral section has a top surface having a surface to which the impact load is applied and a bottom surface having a surface opposite to the top surface, wherein the number of rib hollow sections configured such that the height of the center of gravity of the rib hollow section from the bottom surface is different from the height of the center of gravity of at least one adjacent rib hollow section or peripheral hollow section from the bottom surface in a direction perpendicular to the direction in which the impact load is applied is 50% or more of the total number of rib hollow sections.

2. The vehicle impact absorbing structure according to claim 1, wherein the heights from the bottom surface of the center of gravity of the adjacent rib hollow portion or peripheral hollow portion in a direction perpendicular to the direction in which the impact load is applied are configured to be three or more different heights.

3. The vehicle impact absorbing structure according to claim 1, wherein the shape of the rib hollow portion or the surrounding hollow portion is rectangular.

4. The vehicle impact absorbing structure according to claim 1, wherein the shape of the rib hollow portion or the surrounding hollow portion is polygonal.

5. The vehicle impact absorbing structure according to claim 1, wherein the shape of the rib hollow portion or the surrounding hollow portion is circular.

6. The vehicle impact absorbing structure according to any one of claims 1 to 5, wherein the peripheral portion and the rib portion are made of a thermoplastic resin or a thermosetting resin.

7. The vehicle impact absorbing structure according to any one of claims 1 to 5, wherein the peripheral portion and the rib portion are made of a fiber-reinforced resin containing at least one fiber of glass fiber, carbon fiber, or metal fiber.

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