Shock absorbing structure and bumper core material

Abstract

The shock absorbing structure includes first and second support portions disposed at intervals from each other, and a plurality of deformation portions connected to the first and second support portions via first and second corresponding connection portions, which are corresponding first and second connection portions. Each of the plurality of deformation portions includes: first and second beam portions extending linearly while being inclined to the same side with respect to a corresponding straight line passing through the first and second corresponding connection portions as the first and second beam portions are separated from the first and second corresponding connection portions; and a third beam section that is connected to the ends of the first and second beam sections on the opposite side from the first and second counterconnection sections, and that extends in a curved shape so as to protrude toward the side close to the counterstraight line.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an impact absorbing structure and a bumper core. BACKGROUND

[0002] In Patent Literature 1, a bumper core composed of a polypropylene resin foam is disclosed. Such a bumper core is provided, for example, in the inner side of a front bumper of a motor vehicle, and deforms in a manner of being crushed by itself when the vehicle collides with an object in front, thereby absorbing the impact energy and protecting the vehicle body and the occupants in the vehicle.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2004-168077 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The bumper core disclosed in Patent Literature 1 is composed of a polypropylene resin foam, and therefore, it is possible to prevent a situation in which a large impact force is generated on a pedestrian in the event of a collision with the pedestrian. On the other hand, since the energy that can be absorbed by deformation of the bumper core itself is small, it is possible that the damage to the vehicle cannot be prevented in the event of a collision of the vehicle with an object. Therefore, in order to achieve both the improvement of the collision safety in the event of a collision of the vehicle with a pedestrian and the further prevention of the damage to the vehicle by absorbing the impact energy, as an impact absorbing structure for a bumper core or the like, it is required to consider an impact absorbing structure that can more ensure the impact energy that can be absorbed while suppressing the reaction force generated in the initial stage of the collision.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] According to a first aspect of the present disclosure, there is provided an impact absorbing structure including first and second support portions arranged at intervals from each other, and a plurality of deformation portions connected to the first and second support portions via corresponding first and second connection portions, respectively. Each of the plurality of deformation portions has first and second beam portions extending in straight lines while inclining toward the same side relative to a corresponding straight line passing through the first and second connection portions as the first and second beam portions move away from the first and second connection portions, and a third beam portion connected to end portions of the first and second beam portions on the side opposite the first and second connection portions and extending in a curved line projecting toward the side closer to the corresponding straight line. At least a portion of the plurality of deformation portions is arranged in a manner in which first and second deformation portions are alternately arranged in any number, the first deformation portion being a deformation portion in which the first and second beam portions extend while inclining toward one side relative to the corresponding straight line as the first and second beam portions move away from the first and second connection portions, and the second deformation portion being a deformation portion in which the first and second beam portions extend while inclining toward the other side relative to the corresponding straight line as the first and second beam portions move away from the first and second connection portions.

[0010] According to a second aspect of the present disclosure, there is provided an impact absorbing structure including first and second support portions arranged at intervals from each other, and a plurality of deformation portions connected to the first and second support portions via corresponding first and second connection portions, respectively. Each of the plurality of deformation portions has first and second beam portions extending in straight lines while inclining toward the same side relative to a corresponding straight line passing through the first and second connection portions as the first and second beam portions move away from the first and second connection portions, and a third beam portion connected to end portions of the first and second beam portions on the side opposite the first and second connection portions and extending in a curved line projecting toward the side closer to the corresponding straight line. Each of the plurality of deformation portions is configured to deform in the order of a first stage and a second stage as a displacement amount of a distance between the first and second support portions increases when a load in the direction of the corresponding straight line is applied to at least one of the first and second support portions, in the first stage, a curvature of the third beam portion decreases while an inclination angle of the first and second beam portions relative to the corresponding straight line increases until a portion of each of the first and second beam portions comes into abutment with the first and second support portions, and in the second stage, the curvature of the third beam portion increases in a state in which the portion of each of the first and second beam portions comes into abutment with the first and second support portions.

[0011] According to a third aspect of this disclosure, an impact-absorbing structure is provided, the impact-absorbing structure having first and second support portions arranged at intervals from each other, and a plurality of deformable portions connected to the first and second support portions respectively via corresponding first and second connecting portions, i.e., first and second corresponding connecting portions. Each of the plurality of deformable portions has a first and a second beam portion that extends in a straight line while being inclined to the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as it leaves the first and second corresponding connecting portions, and a third beam portion that extends in a curved shape at the end of the first and second beam portions opposite to the first and second corresponding connecting portions and protrudes toward the side close to the corresponding straight line. The impact-absorbing structure is configured such that when a load along the direction of the corresponding straight line is applied to at least one of the first and second support portions, it presents a first displacement region with an increased displacement amount while maintaining a first reaction force bandwidth, and a second displacement region with an increased displacement amount while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth.

[0012] According to a fourth aspect of this disclosure, an impact-absorbing structure is provided, comprising: first and second support portions arranged at intervals in a first direction; and a pair of deformable portions disposed between the first and second support portions. The pair of deformable portions includes: a pair of first straight beam portions extending such that their intervals gradually increase from the first support portion toward the first direction; a pair of second straight beam portions extending such that their intervals gradually increase from the second support portion toward a direction opposite to the first direction; and a pair of arcuate beam portions disposed between the pair of first and second straight beam portions and arranged such that their respective arcuate protrusions face each other. The impact-absorbing structure is configured such that, when a load is applied to the first or second support portion along the first direction, a first displacement region is generated that shifts while maintaining a first reaction force bandwidth, and a second displacement region is generated that shifts while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth.

[0013] Other features and advantages of this disclosure can be understood from the following illustrative and non-exhaustive description and accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a front view showing an impact-absorbing structure according to one embodiment of the present disclosure.

[0015] Figure 2 This shows the diagram above. Figure 1 The graph shows the relationship between the applied load and the displacement of the impact-absorbing structure.

[0016] Figure 3 It is shown Figure 2 The diagram shows the deformation state of the impact-absorbing structure during the characteristic stages of the load displacement curve.

[0017] Figure 4 This is a perspective view showing an example of a bumper core material that includes an embodiment of the impact-absorbing structure of the present disclosure.

[0018] Figure 5 This is a front view illustrating an impact-absorbing structure according to other embodiments of the present disclosure.

[0019] Figure 6 This is a front view illustrating an impact-absorbing structure according to other embodiments of the present disclosure.

[0020] Figure 7 This shows the diagram above. Figure 6 The graph shows the relationship between the applied load and the displacement of the impact-absorbing structure.

[0021] Figure 8 It is shown Figure 7 The diagram shows the deformation state of the impact-absorbing structure during the characteristic stages of the load displacement curve.

[0022] Figure 9 This is a front view illustrating an impact-absorbing structure according to other embodiments of the present disclosure.

[0023] Figure 10 This is a front view illustrating an impact-absorbing structure according to other embodiments of the present disclosure. Detailed Implementation

[0024] The implementation of this disclosure will now be described with reference to the accompanying drawings.

[0025] First, the structure of the impact-absorbing structure 100 according to one embodiment of the present disclosure will be described. Figure 1 This is a front view showing an impact-absorbing structure according to one embodiment of the present disclosure.

[0026] like Figure 1 As shown, the impact-absorbing structure 100 of this embodiment has first and second support portions 110 and 120 arranged at intervals from each other, and first and second deformable portions 130 and 140 disposed between these first and second support portions 110 and 120. The impact-absorbing structure 100 is composed of these components 110-140 forming a single unit. Furthermore, in Figure 1The diagram schematically illustrates the cross-sectional shapes of the components 110-140 appearing on the front side of the impact-absorbing structure 100, these components 110-140 having a thickness and Figure 1 The paper has a depth on the inside side.

[0027] The first and second deformable portions 130 and 140 each have a first straight beam portion (first beam portion) 132, 142, a second straight beam portion (second beam portion) 134, 144, and a first and second arc-shaped beam portion (third beam portion) 136, 146 respectively disposed between the first straight beam portions 132, 142 and the second straight beam portions 134, 144. One end of each of the first straight beam portions 132, 142 is fixed to the first support portion 110 via a first fixing portion (first corresponding connecting portion) 133, 143, and the first straight beam portions 132, 142 extend in such a way that the spacing between them increases as they move away from the first support portion 110. Similarly, one end of each of the second straight beam portions 134 and 144 is fixed to the second support portion 120 via the second fixing portion (second corresponding connecting portion) 135 and 145, extending in a manner that the distance between them increases as they move away from the second support portion 120. The first and second arcuate beam portions 136 and 146 are arranged with their convex sides facing each other. Thus, the first and second deformable portions 130 and 140 are arranged in a manner that makes them mirror images of each other.

[0028] More specifically, the first and second modified portions 130 and 140 are as described below. The first and second modified portions 130 and 140 in... Figure 1 The first deformable part 130 is the first and second straight beam parts 132 and 134, which, as they leave the first and second fixing parts 133 and 135, are positioned relative to the corresponding straight line L1 passing through the first and second fixing parts 133 and 135 (see reference). Figure 1 The single-dot dashed line) to the same side ( Figure 1 The deformed portion extending obliquely to the left side, the first arc-shaped beam portion 136 is connected to the end of the first and second straight beam portions 132, 134 on the side opposite to the first and second fixing portions 133, 135 and is oriented towards the side approaching the corresponding straight line L1. Figure 1 (Right side) A convex arc-shaped extension. The second deformable portion 140 is the first and second straight beam portions 142, 144 that, as they leave the first and second fixing portions 143, 145, extend relative to the corresponding straight line L2 passing through the first and second fixing portions 143, 145 (see reference). Figure 1 The double-dotted line) is to the same side ( Figure 1The deformed portion extending obliquely to the right side, the second arc-shaped beam portion 146 is connected to the end of the first and second straight beam portions 142, 144 on the side opposite to the first and second fixing portions 143, 145 and is oriented toward the side approaching the corresponding straight line L2. Figure 1 The left side of the curve extends in a convex arc shape. The corresponding straight lines L1 and L2 are parallel to each other. The first and second straight beams 132 and 134 of the first deformed part 130 and the first and second straight beams 142 and 144 of the second deformed part 140 are all straight lines of the same length and with the same inclination relative to the corresponding straight lines L1 and L2. The first and second arc-shaped beams 136 and 146 extend in an arc shape with the same curvature. In addition, the first and second arc-shaped beams 136 and 146 are not limited to arc shape as long as they are curved; for example, they can also be elliptical arcs, sine waves, etc.

[0029] In each of the deformable portions 130 and 140, it is preferable that the first straight beam portions 132 and 142, the second straight beam portions 134 and 144, and the first and second arc-shaped beam portions 136 and 146 between the first straight beam portions 132 and 142 and the second straight beam portions 134 and 144 are integrally formed. More preferably, each deformable portion 130 and 140 is also integrally formed with the first and second support portions 110 and 120. The impact-absorbing structure 100 of this embodiment can be configured as an integrally formed component, for example, by injection molding, blow molding, extrusion molding, 3D printing of resin materials, or casting, forging, pressing, cutting, extrusion molding, 3D printing, etc. of metal materials. Alternatively, regarding the impact-absorbing structure 100 of this embodiment, the beams in each of the deformable parts 130 and 140 can be joined or fastened to each other by any fastening connection means such as adhesive, welding, bolt fastening, or riveting. Furthermore, each of the deformable parts 130 and 140 can be joined or fastened to the first and second support parts 110 and 120 by the same means.

[0030] Figure 2 This shows the diagram above. Figure 1 The graph shows the relationship between the load (reaction force of the impact-absorbing structure 100) applied to the impact-absorbing structure 100 and the displacement of the impact-absorbing structure 100 (the displacement of the distance between the first and second support portions 110 and 120). Figure 3 It is shown Figure 2 A diagram showing the deformation state of the impact-absorbing structure 100 in a characteristic stage of the load displacement curve.

[0031] Here, a specific embodiment of the shock-absorbing structure 100 of this embodiment will be described. In this embodiment, as an example, the shock-absorbing structure 100 is configured according to the following elements.

[0032] (Material)

[0033] Polycarbonate

[0034] (size)

[0035] • Overall dimensions of structure 100: Horizontal (left-right direction in the diagram) 33.4mm, Depth (paper direction in the diagram) 150mm, Height (vertical direction in the diagram) 80mm

[0036] • Thickness of each component (110~140): 2.5mm

[0037] • Length of straight beam sections 132, 134; 142, 144: 29.1mm

[0038] • Radius of the arc-shaped beams 136 and 146 • Arc length: radius 13.8mm, arc length 30.8mm

[0039] • The spacing between the first straight beams 132 and 142 at the connection point where they connect to the first support 110 (distance between the centers of each beam): 6mm

[0040] • The spacing between the second straight beams 134 and 144 at the connection point where they connect to the second support 120 (distance between the centers of each beam): 6mm

[0041] Figure 2 and Figure 3 The results are simulations of the load (reaction force) and displacement in the vertical direction of the impact-absorbing structure 100 when a load is applied from above to the impact-absorbing structure 100 constructed according to the above-described requirements. The simulation results confirm that the impact-absorbing structure 100 deforms in the following sequence: Stage 1, Stage 2.

[0042] In the first stage of deformation of the impact-absorbing structure 100, such as Figure 3 (A) ~ Figure 3As shown in (c), due to the deformation of the first straight beam portions 132, 142, the second straight beam portions 134, 144, and the first and second arc-shaped beam portions 136, 146, the inclination angles of the first straight beam portions 132, 142 and the second straight beam portions 134, 144 relative to the corresponding straight lines L1, L2 gradually increase, while the curvature of the first and second arc-shaped beam portions 136, 146 gradually decreases. A portion of each of the first straight beam portions 132, 142 abuts against the first support portion 110, and a portion of each of the second straight beam portions 134, 144 abuts against the second support portion 120. In this first stage of deformation, as... Figure 2 As shown, in the region with a displacement of 0 mm to approximately 10 mm, the load (reaction force) and displacement gradually increase in a roughly linear manner as the displacement increases. In the region with a displacement of approximately 10 mm to 42 mm, even as the displacement increases, the load is pushed by 1800 N to 2500 N.

[0043] In the second stage of deformation of the impact-absorbing structure 100, such as Figure 3 (C) ~ Figure 3 As shown in (E), with a portion of each of the first straight beam portions 132 and 142 abutting against the first support portion 110 and a portion of each of the second straight beam portions 134 and 144 abutting against the second support portion 120, the curvature of the first and second arcuate beam portions 136 and 146 gradually increases due to the deformation of the first and second arcuate beam portions 136 and 146. In this second stage of deformation, as... Figure 2 As shown, in the region with a displacement of approximately 42 mm to approximately 50 mm, the load (reaction force) and displacement gradually increase in a roughly linear manner as the displacement increases. In the region with a displacement of approximately 50 mm to approximately 60 mm, even with an increase in displacement, the load is shifted to approximately 5500 N to 6000 N.

[0044] Furthermore, if the deformation of the impact-absorbing structure 100 intensifies further and reaches a so-called bottoming-out state where it no longer deforms, the displacement will not increase but only the load will increase.

[0045] Thus, according to the impact-absorbing structure 100 of this embodiment, a first displacement region is generated that shifts while maintaining a first reaction force bandwidth that is substantially low relative to the load. Figure 2 The middle region is approximately 10mm to approximately 42mm, and the second displacement region (in the area where the second reaction force bandwidth is maintained at approximately the higher reaction force against the load) shifts. Figure 2The load displacement characteristics of the deformation zone (approximately 50mm to 60mm in the middle) are observed in two stages. Therefore, it is possible to suppress the reaction force in the first displacement zone while absorbing more collision energy in the second displacement zone. That is, it is possible to suppress the reaction force generated in the initial stage of a collision while ensuring greater absorption of collision energy. Therefore, when the impact-absorbing structure 100 is used in the bumper core material of a vehicle, the impact on pedestrians is suppressed in the first displacement zone due to the smaller reaction force, and more collision energy of the vehicle is absorbed in the second displacement zone. As a result, it is possible to simultaneously improve the collision safety of people in the event of a vehicle-pedestrian collision and further protect the vehicle and its occupants by absorbing collision energy.

[0046] Figure 4 This is a perspective view showing an example of a bumper core material 200 including the impact-absorbing structure 100 of this embodiment.

[0047] like Figure 4 As shown, the bumper core material 200 has a configuration in which the impact-absorbing structures 100 of this embodiment are arranged side by side in a row. The bumper core material 200 has a first side portion 210 and a second side portion 220, which also serve as the first and second support portions 110 and 120 of the impact-absorbing structures 100. By placing the bumper core material 200 configured in this way on the inside of the vehicle's bumper, as described above, the collision safety of people in the event of a collision between the vehicle and a person can be improved, and the collision energy can be absorbed to protect the vehicle and the occupants inside the vehicle.

[0048] In the above implementation methods, such as Figure 1 As shown in the shock-absorbing structure 100, the first and second deformed portions 130 and 140 are arranged in the order of left side of the figure, but this is not a limitation. For example, it may also be as follows: Figure 5 , Figure 6 The shock-absorbing structures shown are constructed as in 100B and 100C.

[0049] Figure 5 The impact spherical structure 100B shown is relative to Figure 1 The shock-absorbing structure 100 shown differs from the shock-absorbing structure 100 in that the left-right arrangement of the first and second deformable portions 130 and 140 in the illustration is swapped. That is, in the shock-absorbing structure 100B, the second and first deformable portions 140 and 130 are arranged in the order of left to right in the illustration. The shock-absorbing structures 100 and 100B are identical except for the swapped left-right arrangement in the illustration; therefore, the shock-absorbing structure 100B can achieve the same effect as the shock-absorbing structure 100.

[0050] Figure 6 The shock-absorbing structure 100C shown is relative to Figure 1 The shock-absorbing structure 100 shown differs from the shock-absorbing structure 100 in that the first deformed portion 130 is replaced by a second deformed portion 140. That is, in the shock-absorbing structure 100C, the two second deformed portions 140 are arranged in the left-right direction as shown in the figure. Furthermore, when the shock-absorbing structure 100C is viewed from the inside, it can be said that the two first deformed portions 130 are arranged in the left-right direction as shown in the figure.

[0051] Figure 7 This shows the diagram above. Figure 6 The graph shows the relationship between the applied load and the displacement of the impact-absorbing structure 100C. Figure 8 It is shown Figure 7 The diagram shows the deformation state of the impact-absorbing structure 100C in a characteristic stage of the load displacement curve. In one embodiment, as an example, the impact-absorbing structure 200B is constructed according to the same elements as the impact-absorbing structure 100 described above.

[0052] Figure 7 and Figure 8 The results are simulations of the load (reaction force) and displacement in the vertical direction of the impact-absorbing structure 100C when a load is applied from above to the impact-absorbing structure 100C, which is constructed according to the same components as the impact-absorbing structure 100. Figure 2 and Figure 7 Compare and Figure 3 and Figure 8 When comparing the results, it can be seen that stages 1 and 2 in the simulation results for impact-absorbing structure 100 correspond to stages 1 to 4 and 2 in the simulation results for impact-absorbing structure 100C. Figure 3 (A) ~ Figure 3 (E) and Figure 8 (A) ~ Figure 8 (E) Corresponding to each other. Therefore, even Figure 6 The shock-absorbing structure 100C shown can also play a role similar to Figure 1 The shock-absorbing structure 100 shown has the same effect.

[0053] The impact-absorbing structure 100C has two second deformation parts 140 (which are first deformation parts 130 when viewed from the inside), but it may also have three or more.

[0054] In the above implementation methods, such as Figure 1 , Figure 5As shown in the impact-absorbing structures 100 and 100B, a first deformable portion 130 and a second deformable portion 140 are arranged in a mirror image of each other, but this is not a limitation. For example, it may also be as follows: Figure 9 Like the shock-absorbing structure 100D shown, multiple (in) Figure 9 The first deformable part 130 (3 in total) and the second deformable part 140 of the same number are arranged in a mirror image of each other. In addition, the number of the first deformable part 130 and the number of the second deformable part 140 may be different.

[0055] In the above implementation methods, such as Figure 1 , Figure 5 As shown in the impact-absorbing structures 100 and 100B, each has one set of first and second deformed portions 130 and 140, but this is not a limitation. For example, multiple sets of the first and second deformed portions 130 and 140 of the impact-absorbing structure 100 may also be arranged (see [reference]). Figure 4 Furthermore, multiple sets of the first and second deformable portions 130 and 140 of the impact-absorbing structure 100B can be arranged. Moreover, n1 (n1≥1) sets of the first and second deformable portions 130 and 140 of the impact-absorbing structure 100 and n2 (n2≥1) sets of the first and second deformable portions 130 and 140 of the impact-absorbing structure 100B can be arranged in any order. At least one of n3 (n3≥1) first deformable portions 130 and n4 (n4≥1) second deformable portions 140 can also be added to them.

[0056] In the above implementation methods, such as Figure 1 , Figure 5 , Figure 6 , Figure 9 As shown in the impact-absorbing structures 100, 100B, 100C, 100D, etc., the first deformable portion 130 and / or the second deformable portion 140 are arranged in the left-right direction as illustrated. However, the first deformable portion 130 and / or the second deformable portion 140 may also be arranged in the direction through the paper, etc., based on or instead of this arrangement.

[0057] In the above implementation methods, such as Figure 1 , Figure 5 , Figure 6 As shown in the impact-absorbing structures 100, 100B, 100C, etc., the first and second support portions 110 and 120 are both straight (flat) and the distance between them is constant, but not limited to this. For example, the first and second support portions 110 and 120 can also be curved (see [reference]). Figure 4 Alternatively, the distance between the first and second support portions 110 and 120 may not be fixed. For example, it could be achieved by means such as... Figure 10As shown in the impact-absorbing structure 100E, the second support portion 120 has a step, so that the distance between the first and second support portions 110 and 120 is not constant.

[0058] The present disclosure has been described above through the disclosed embodiments and examples, but the above embodiments and examples do not limit the invention of the claims. Furthermore, combinations of the features described in the embodiments and examples of the present disclosure may also be included within the technical scope of the present disclosure.

[0059] [Postscript]

[0060] [1] The first impact-absorbing structure of this disclosure includes first and second support portions arranged at intervals from each other, and a plurality of deformable portions connected to the first and second support portions respectively via corresponding first and second connecting portions, i.e., first and second corresponding connecting portions. The key point is that each of the plurality of deformable portions has a first and second beam portion that extends linearly while being inclined to the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as it moves away from the first and second corresponding connecting portions, and a first and second beam portion that is connected to the first and second beam portion and the first and second corresponding connecting portions. The third beam portion extends in a curved shape from the end opposite to the connecting portion, protruding towards the side close to the corresponding straight line. At least a portion of the plurality of deformable portions are arranged in an alternating manner with the first deformable portion and the second deformable portion in any number. The first deformable portion is the deformable portion of the first and second beam portions that extends obliquely to one side relative to the corresponding straight line as they leave the first and second corresponding connecting portions. The second deformable portion is the deformable portion of the first and second beam portions that extends obliquely to the other side relative to the corresponding straight line as they leave the first and second corresponding connecting portions.

[0061] In the first impact-absorbing structure disclosed herein, each of the plurality of deformable portions has a first and a second beam portion that extends linearly while inclining to the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as they leave the first and second corresponding connecting portions, and a third beam portion that extends in a curved shape from the end of the first and second beam portions on the side opposite to the first and second corresponding connecting portions, protruding towards the side approaching the corresponding straight line. Furthermore, at least a portion of the plurality of deformable portions is arranged such that the first and second deformable portions are arranged alternately in any number, wherein the first deformable portion is the deformable portion of the first and second beam portions that extends inclining to one side relative to the corresponding straight line as they leave the first and second corresponding connecting portions, and the second deformable portion is the deformable portion of the first and second beam portions that extends inclining to the other side relative to the corresponding straight line as they leave the first and second corresponding connecting portions. Thus, it is possible to suppress the reaction force generated in the initial stage of a collision while further ensuring the amount of impact energy that can be absorbed. The inventors have confirmed the above through simulations and the like.

[0062] [2] In the first impact-absorbing structure of this disclosure (the impact-absorbing structure described in [1] above), the plurality of deformable portions may have the same number of first deformable portions and second deformable portions as each other. The first deformable portion is a deformable portion in which the first and second beam portions extend obliquely to one side relative to the corresponding straight line as they leave the first and second corresponding connecting portions. The second deformable portion is a deformable portion in which the first and second beam portions extend obliquely to the other side relative to the corresponding straight line as they leave the first and second corresponding connecting portions.

[0063] [3] The second impact-absorbing structure of this disclosure includes first and second support portions arranged at intervals from each other, and a plurality of deformable portions connected to the first and second support portions respectively via corresponding first and second connecting portions, i.e., first and second corresponding connecting portions. The key point is that each of the plurality of deformable portions has a first and second beam portion that extends linearly while inclining to the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as it moves away from the first and second corresponding connecting portions, and an end portion connected to the first and second beam portion on the side opposite to the first and second corresponding connecting portions that extends in a curved shape convex toward the side approaching the corresponding straight line. The third beam portion, wherein the plurality of deformable portions are respectively configured such that, when a load along the corresponding straight line is applied to at least one of the first and second support portions, deformation occurs in the order of a first stage and a second stage as the displacement of the distance between the first and second support portions increases. In the first stage, the curvature of the third beam portion decreases as the inclination angle of the first and second beam portions relative to the corresponding straight line increases until a portion of each of the first and second beam portions abuts against the first and second support portions. In the second stage, the curvature of the third beam portion increases while a portion of each of the first and second beam portions abuts against the first and second support portions.

[0064] In the second impact-absorbing structure disclosed herein, each of the plurality of deformable portions has a first and a second beam portion that extend in a straight line while being inclined to the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as they leave the first and second corresponding connecting portions, and a third beam portion that extends in a curved shape at the end of the first and second beam portions on the side opposite to the first and second corresponding connecting portions and protrudes toward the side close to the corresponding straight line. Furthermore, the multiple deformable parts are configured such that when a load along a corresponding straight line is applied to at least one of the first and second support portions, deformation occurs sequentially in stages 1 and 2 as the displacement between the first and second support portions increases. In the first stage, the curvature of the third beam portion decreases while the inclination angle of the first and second beam portions relative to the corresponding straight line increases until a portion of each of the first and second beam portions abuts against the first and second support portions. In the second stage, the curvature of the third beam portion increases while a portion of each of the first and second beam portions abuts against the first and second support portions. This allows for the suppression of reaction forces generated in the initial stage of a collision while further ensuring the absorption of collision energy. The inventors confirmed this through simulations and other methods.

[0065] [4] The third impact-absorbing structure of this disclosure includes first and second support portions arranged at intervals from each other and a plurality of deformable portions connected to the first and second support portions respectively via corresponding first and second connecting portions, i.e., first and second corresponding connecting portions. The key point is that each of the plurality of deformable portions has a first and second beam portion that extends in a straight line while being inclined to the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as it leaves the first and second corresponding connecting portions, and a third beam portion that extends in a curved shape and is connected to the end of the first and second beam portions on the side opposite to the first and second corresponding connecting portions and protrudes towards the side close to the corresponding straight line. The impact-absorbing structure is configured such that when a load along the direction of the corresponding straight line is applied to at least one of the first and second support portions, a first displacement region with an increased displacement amount while maintaining a first reaction force bandwidth and a second displacement region with an increased displacement amount while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth.

[0066] In the third impact-absorbing structure disclosed herein, each of the plurality of deformable portions has a first and a second beam portion that extend linearly while inclining towards the same side relative to the corresponding straight line passing through the first and second corresponding connecting portions as they move away from the first and second corresponding connecting portions, and a third beam portion that extends in a curved shape from the end of the first and second beam portions on the side opposite to the first and second corresponding connecting portions, protruding towards the side approaching the corresponding straight line. Furthermore, the impact-absorbing structure is configured such that when a load along the corresponding straight line is applied to at least one of the first and second supporting portions, a first displacement region exhibits a first displacement region where the displacement amount increases while maintaining a first reaction force bandwidth, and a second displacement region where the displacement amount increases while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth. Thus, it is possible to suppress the reaction force generated in the initial stage of a collision while further ensuring the amount of impact energy that can be absorbed. The inventors have confirmed the above through simulations and the like.

[0067] [5] In any of the first to third impact-absorbing structures of this disclosure (the impact-absorbing structures described in any of the above [1] to [4]), the impact-absorbing structure may also be integrally formed.

[0068] [6] The key point of the bumper core material of this disclosure is that it has any one of the first to third impact-absorbing structures of this disclosure (the impact-absorbing structures described in any one of [1] to [5] above). Therefore, it can achieve the same effect as the impact-absorbing structures of the first to third impact-absorbing structures of this disclosure.

[0069] [7] The fourth impact-absorbing structure of this disclosure includes first and second support portions arranged at intervals in a first direction and a pair of deformable portions disposed between the first support portion and the second support portion. The key point is that the pair of deformable portions has: a pair of first straight beam portions extending in a manner in which the interval between them gradually increases from the first support portion toward the first direction; a pair of second straight beam portions extending in a manner in which the interval between them gradually increases from the second support portion toward a direction opposite to the first direction; and a pair of arcuate beam portions disposed between the pair of first straight beam portions and the pair of second straight beam portions and arranged in a manner in which the protrusions of their respective arcs face each other. The impact-absorbing structure is configured such that when a load is applied to the first support portion or the second support portion along the first direction, a first displacement region is generated that shifts while maintaining a first reaction force bandwidth, and a second displacement region is generated that shifts while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth.

[0070] In the fourth impact-absorbing structure disclosed herein, a pair of deformable portions includes: a pair of first straight beam portions extending such that their spacing gradually increases from the first support portion toward a first direction; a pair of second straight beam portions extending such that their spacing gradually increases from the second support portion toward a direction opposite to the first direction; and a pair of arc-shaped beam portions disposed between the pair of first straight beam portions and the pair of second straight beam portions and arranged such that their respective arcuate protrusions face each other. Furthermore, the impact-absorbing structure is configured such that, when a load is applied to the first support portion or the second support portion along the first direction, a first displacement region is generated that shifts while maintaining a first reaction force bandwidth, and a second displacement region is generated that shifts while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth. Thus, it is possible to more adequately ensure the absorption of impact energy while suppressing the reaction force generated in the initial stage of a collision. The inventors have confirmed the above through simulations and the like.

[0071] [8] In the fourth shock-absorbing structure of this disclosure (the shock-absorbing structure described in [7] above), the shock-absorbing structure may also be integrally formed.

Claims

1. An impact-absorbing structure, comprising: The first support portion and the second support portion are arranged at intervals from each other; and Multiple deformable parts are respectively connected to the first support part and the second support part via corresponding first connecting parts and second connecting parts, i.e., first corresponding connecting parts and second corresponding connecting parts. in, Each of the plurality of deformable parts has: The first beam portion and the second beam portion extend in a straight line while being inclined to the same side relative to the corresponding straight line passing through the first corresponding connecting portion and the second corresponding connecting portion, respectively, as they leave the first corresponding connecting portion and the second corresponding connecting portion; and The third beam portion connects to the end of the first beam portion and the second beam portion on the opposite side of the corresponding first and second connecting portions, and extends in a curved shape protruding towards the side that is close to the corresponding straight line. At least a portion of the plurality of deformable portions are arranged in an alternating manner with a first deformable portion and a second deformable portion in any number. The first deformable portion is a deformable portion in which the first beam portion and the second beam portion extend obliquely to one side relative to the corresponding straight line as they leave the first corresponding connecting portion and the second corresponding connecting portion. The second deformable portion is a deformable portion in which the first beam portion and the second beam portion extend obliquely to the other side relative to the corresponding straight line as they leave the first corresponding connecting portion and the second corresponding connecting portion.

2. The impact-absorbing structure according to claim 1, wherein, The plurality of deformable portions have the same number of first deformable portions and second deformable portions as each other. The first deformable portion is a deformable portion in which the first beam portion and the second beam portion extend obliquely to one side relative to the corresponding straight line as they leave the first corresponding connecting portion and the second corresponding connecting portion. The second deformable portion is a deformable portion in which the first beam portion and the second beam portion extend obliquely to the other side relative to the corresponding straight line as they leave the first corresponding connecting portion and the second corresponding connecting portion.

3. An impact-absorbing structure, comprising: The first support portion and the second support portion are arranged at intervals from each other; and Multiple deformable parts are respectively connected to the first support part and the second support part via corresponding first connecting parts and second connecting parts, i.e., first corresponding connecting parts and second corresponding connecting parts. in, Each of the plurality of deformable parts has: The first beam portion and the second beam portion extend in a straight line while being inclined to the same side relative to the corresponding straight line passing through the first corresponding connecting portion and the second corresponding connecting portion, respectively, as they leave the first corresponding connecting portion and the second corresponding connecting portion; and The third beam portion connects to the end of the first beam portion and the second beam portion on the opposite side of the corresponding first and second connecting portions, and extends in a curved shape protruding towards the side that is close to the corresponding straight line. The plurality of deformable parts are respectively configured as follows: When a load along the corresponding straight line is applied to at least one of the first support portion and the second support portion, deformation occurs in the order of the first stage and the second stage as the displacement of the distance between the first support portion and the second support portion increases. In the first stage, as the inclination angles of the first beam and the second beam relative to the corresponding straight line increase, the curvature of the third beam decreases until a portion of each of the first beam and the second beam abuts against the first support portion and the second support portion. In the second stage, the curvature of the third beam increases while a portion of each of the first beam and the second beam is in contact with the first support and the second support.

4. An impact-absorbing structure, comprising: The first support portion and the second support portion are arranged at intervals from each other; and Multiple deformable parts are respectively connected to the first support part and the second support part via corresponding first connecting parts and second connecting parts, i.e., first corresponding connecting parts and second corresponding connecting parts. in, Each of the plurality of deformable parts has: The first beam portion and the second beam portion extend in a straight line while being inclined to the same side relative to the corresponding straight line passing through the first corresponding connecting portion and the second corresponding connecting portion, respectively, as they leave the first corresponding connecting portion and the second corresponding connecting portion; and The third beam portion connects to the end of the first beam portion and the second beam portion on the opposite side of the corresponding first and second connecting portions, and extends in a curved shape protruding towards the side that is close to the corresponding straight line. The impact-absorbing structure is configured such that when a load along the corresponding straight line is applied to at least one of the first support portion and the second support portion, it presents a first displacement region with an increased displacement amount while maintaining a first reaction force bandwidth, and a second displacement region with an increased displacement amount while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth.

5. The impact-absorbing structure according to any one of claims 1, 3, and 4, wherein, The impact-absorbing structure is integrally formed.

6. A bumper core material comprising the impact-absorbing structure as described in any one of claims 1, 3, and 4.

7. An impact-absorbing structure, comprising: The first support portion and the second support portion are arranged at a distance from each other in the first direction; and A pair of deformable portions are disposed between the first support portion and the second support portion. in, The pair of deformable portions have: A pair of first straight beam portions extend in such a manner that the spacing between them gradually increases as they move from the first support portion toward the first direction; A pair of second straight beam portions extend in a manner that gradually increases in spacing from the second support portion toward a direction opposite to the first direction; and A pair of arc-shaped beam portions are disposed between the pair of first straight beam portions and the pair of second straight beam portions, and are arranged such that their respective arc-shaped protrusions face each other. The impact-absorbing structure is configured such that when a load is applied to the first support portion or the second support portion along the first direction, a first displacement region is generated that shifts while maintaining a first reaction force bandwidth, and a second displacement region is generated that shifts while maintaining a second reaction force bandwidth larger than the first reaction force bandwidth.

8. The impact-absorbing structure according to claim 7, wherein, The impact-absorbing structure is integrally formed.

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