Energy absorption structure part

Abstract

The configuration enables reduction of the HIC value. 【Solution means】In an energy absorption member having a shape in which a plurality of unit units having unevenness are connected along the extending direction of a predetermined surface, when a spherical portion of an external object collides, the energy absorption member is configured to absorb the collision energy with the spherical portion along with the crushing of the unit unit in contact with the spherical portion and the spread along the extending direction of the predetermined surface.

Description

Technical Field

[0001] The present disclosure relates to an energy absorption member and an energy absorption structure.

Background Art

[0002] Conventionally, an energy absorption member has been proposed which is interposed between a body member and an interior material of a vehicle and includes a base and a plurality of structures regularly distributed on the base (see Patent Document 1). Here, the structure has a truncated square pyramid shape with a hollow interior and an open base, having a ceiling and four side walls. Further, in the structure, the thickness of the corner connecting two adjacent side walls is formed thinner than the thickness of each side wall body. In this energy absorption member, when subjected to an impact load, two adjacent side walls of the structure are torn apart from each other, and each side wall buckles independently.

[0003] Also, an energy absorption member in which a plurality of protrusions are radially arranged has been proposed (see Patent Document 2). Here, the protrusion has a hexagonal top surface and side pieces extending downward following each side of the top surface, and the bottom portion has a hexagonal shape similar to the top surface. Further, the protrusions are connected to adjacent protrusions by connecting pieces extending from each bottom side of the bottom portion. The connecting pieces are fixed to a roof liner by welding or by an adhesive. In this energy absorption member, a compressive load is transmitted from the top surface of the protrusion to each side piece, causing each side piece to buckle and deform, and then transmitted from each side piece to each connecting piece, inducing bending deformation, and further absorbed by being radially transmitted to each protrusion through each connecting piece.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, as one of the performance evaluations of an energy absorption member, a Head Injury Criterion (HIC) value may be used. The inventors have confirmed by analysis and the like that in the energy absorption members of Patent Documents 1 and 2, the HIC value tends to be relatively high when the spherical portion of an external object (for example, a Free Motion Head Form (FMH)) collides. This is because the number of structures (see Patent Document 1) or protrusions (see Patent Document 2) that come into contact with and deform the spherical portion gradually increases over a certain period of time from the start of the collision between the spherical portion and the energy absorption member. Therefore, the combined acceleration tends to plateau over a certain period of time, that is, the waveform of the combined acceleration is likely to deviate significantly from an ideal waveform (a waveform that is infinite at the beginning and then decreases exponentially, see Document A). Based on this, there is a need to devise an energy absorption member capable of reducing the HIC value. Document A: Koji Mizuno, "Automobile Collision Safety", Nagoya University Press, published on February 29, 2012, pp. 14 - 16

[0006] The main object of the energy absorption member and the energy absorption structure of the present disclosure is to have a configuration capable of reducing the HIC value.

Means for Solving the Problems

[0007] The present disclosure has adopted the following means to achieve the above main object.

[0008] The energy absorption member of the present disclosure is an energy absorption member having a shape in which a plurality of unit units having irregularities are connected along the extending direction of a predetermined surface, wherein the energy absorption member is configured to absorb collision energy with the spherical portion along with the crushing of the unit unit in contact with the spherical portion and the spread along the extending direction of the predetermined surface when the spherical portion of an external object collides. This is the gist.

[0009] In the energy absorption member of the present disclosure, when the spherical portion of an external object collides, the unit unit in contact with the spherical portion collapses and spreads along the extending direction of a predetermined surface. Thereby, the HIC value can be reduced. The inventors confirmed this by analysis and the like. Here, the predetermined surface may be a flat surface or a curved surface.

Brief Description of the Drawings

[0010]

Figure 1

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Mode for Carrying Out the Invention

[0011] A mode (embodiment) for carrying out the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view of the energy absorption member 10 of the embodiment of the present disclosure as seen from the upper right front. FIG. 2A is a sectional view taken along line A-A of FIG. 1, and FIG. 2B is a sectional view taken along line B-B of FIG. 1. The front-rear direction (first direction), left-right direction (second direction), and up-down direction of the energy absorption member 10 are as shown in FIGS. 1, 2A, and 2B.

[0012] The energy absorption member 10 of the embodiment is an integrally molded product, and is integrally molded, for example, by injection molding, blow molding, extrusion molding, 3D printing, etc. of a resin material, or by casting, forging, pressing, cutting, extrusion molding, 3D printing, etc. of a metal material. As shown in FIGS. 1, 2A, and 2B, the energy absorption member 10 is formed in a shape in which a plurality of unit units 12 having unevenness are connected along the extending direction of a predetermined surface P0. The predetermined surface P0 is a plane extending along the front-rear direction and the left-right direction (see FIGS. 2A and 2B).

[0013] The plurality of unit units 12 are arranged side by side in the front - rear direction and the left - right direction. Two adjacent unit units 12 in the front - rear direction are connected, and two adjacent unit units 12 in the left - right direction are connected. Each unit unit 12 has a top surface portion 14 and four connecting portions 20, respectively.

[0014] The top surface portion 14 extends along the first surface P1 and is formed in a quadrilateral shape (specifically, a square shape) having four side portions 16. The first surface P1 is a plane parallel to the predetermined surface P0 (see FIGS. 2A and 2B). Two of the four side portions 16 that face each other extend in the front - rear direction, and the remaining two that face each other extend in the left - right direction. Therefore, the side portions 16 of two adjacent unit units 12 in the front - rear direction that face each other both extend in the left - right direction and are parallel to each other. Also, the side portions 16 of two adjacent unit units 12 in the left - right direction that face each other both extend in the front - rear direction and are parallel to each other.

[0015] The four connecting parts 20 each have a first leg part 22 and a second leg part 24. The first leg part 22 extends from the corresponding side part 16 and extends downward from the first surface P1 to reach the second surface P2. The angle formed between the top surface part 14 and each first leg part 22 is an obtuse angle. The second surface P2 is a plane parallel to the predetermined surface P0 and the first surface P1 (see FIGS. 2A and 2B). The second leg part 24 extends from the end part (lower end part) on the side opposite to the side part 16 of the first leg part 22 and extends along the second surface P2 to the second leg part 24 side of the adjacent unit unit 12 in the front-back direction or the left-right direction. The second leg part 24 of the connecting part 20 is connected only to the second leg part 24 of the adjacent connecting part 20 in the front-back direction or the left-right direction. That is, in the front-back direction and the left-right direction, the corresponding connecting parts 20 of two adjacent unit units 12 are connected only to each other (one-to-one) at the end parts on the side opposite to the first leg part 22 of the second leg part 24. Hereinafter, the part formed by the second leg parts 24 of two adjacent unit units 12 is referred to as a bottom surface part 26. Each bottom surface part 26 extends along the second surface P2 respectively.

[0016] In the unit unit 12 configured in this way, unevenness is formed by the four connecting parts 20 (the first leg part 22 and the second leg part 24) and the top surface part 14. Further, in the energy absorption member 10 in which a plurality of unit units 12 are connected, the upper surface of the top surface part 14 becomes the upper surface of the energy absorption member 10, and the lower surface of the bottom surface part 26 becomes the lower surface of the energy absorption member 10.

[0017] Next, a usage example of the energy absorption member 10 of the embodiment will be described with reference to FIG. 3. As shown in the drawing, the energy absorption member 10 of the embodiment is used as the energy absorption structure portion 40. The energy absorption structure portion 40 is configured by arranging the energy absorption member 10 between the first member 42 and the second member 44 such that the second leg portion 24 is on the first member 42 side and the top surface portion 14 is on the second member 44 side. Both the first member 42 and the second member 44 are plate-shaped and are arranged to face each other with a space therebetween. Note that the shape of the first member 42 only needs to be such that the surface on the energy absorption member 10 side is a flat surface, and it does not have to be plate-shaped. Various methods of arranging the energy absorption member 10 can be considered. For example, when the first member 42, the second member 44, and the energy absorption member 10 are arranged to extend in the vertical direction, respectively, the energy absorption member 10 may be suspended by a third member arranged above it. Also, when the first member 42, the second member 44, and the energy absorption member 10 are arranged to extend in the horizontal direction, respectively, the energy absorption member 10 may be non-fixedly placed on the member on the lower side of the energy absorption member 10 among the first member 42 or the second member 44, or may be suspended by the member on the upper side of the energy absorption member 10 so as not to prevent the deformation of the energy absorption member 10. That is, the energy absorption member 10 only needs to be arranged between the first member 42 and the second member 44 so that its deformation is not hindered. When the energy absorption member 10 is used in a vehicle, examples of the combination of the first member 42 and the second member 44 include a pillar and a pillar garnish, a suspension tower and an outer hood, a roof rain hose mount and a roof lining, and the like.

[0018] Next, a comparison will be made between the energy absorption structure 40 including the energy absorption member 10 of the embodiment and the energy absorption structures 40B, 40C, and 40D each including the energy absorption members 10B, 10C, and 10D of the first, second, and third comparative examples. Similar to the energy absorption structure 40 of the embodiment, the energy absorption structures 40B, 40C, and 40D of the first, second, and third comparative examples are configured such that the energy absorption members 10B, 10C, and 10D are disposed between the first member 42 and the second member 44 (arranged in the same manner as in FIG. 3) (all are not shown).

[0019] FIG. 4 is a perspective view of the energy absorption member 10B of the first comparative example as viewed from the upper right front. As shown in FIG. 4, the energy absorption member 10B has a shape in which a plurality of bottom surfaces 26 in the energy absorption member 10 of the embodiment are connected in the front-rear direction and the left-right direction. Hereinafter, the entire portion connecting the plurality of bottom surfaces 26 in the front-rear direction and the left-right direction is referred to as the bottom surface 26B. By the bottom surface 26B, in each unit unit 12, the four connecting portions 20 are connected to each other.

[0020] FIG. 5 is a perspective view of the energy absorption member 10C of the second comparative example as viewed from the lower left rear. As shown in FIG. 5, the energy absorption member 10C is configured identically to the energy absorption member 10 of the embodiment. In the energy absorption structure 40C including the energy absorption member 10C, the entire lower surface of the energy absorption member 10C, specifically, the lower surfaces of all the bottom surfaces 26 (see the hatched portion in FIG. 5) are fixed to the first member 42.

[0021] FIG. 6 is a perspective view of the energy absorption member 10D of the third comparative example as viewed from the lower left rear. As shown in FIG. 6, the energy absorption member 10D is configured identically to the energy absorption member 10 of the embodiment. In the energy absorption structure 40D including the energy absorption member 10D, a part of the lower surface of the energy absorption member 10D, specifically, the lower surfaces of every other bottom surface 26 in the front-rear direction and the left-right direction (see the hatching in FIG. 6) are fixed to the first member 42.

[0022] Next, an analysis of the energy absorption structure parts 40, 40B, 40C, 40D each including the energy absorption member 10 of the embodiment and the energy absorption members 10B, 10C, 10D of the first, second, and third comparative examples will be described. FIG. 7 is an explanatory diagram showing the state of the analysis of the energy absorption structure part 40 of the embodiment. The same applies to the energy absorption structure parts 40B, 40C, 40D of the first, second, and third comparative examples. In this analysis, the energy absorption members 10, 10B, 10C, 10D are all formed of the same material, specifically, polypropylene. Further, in the analysis, a head dummy (FMH) 50 having a spherical part 52 was collided with the second member 44 side at an initial velocity of 24 km / h against the energy absorption structure parts 40, 40B, 40C, 40D. In the analysis, gravity was ignored.

[0023] FIGS. 8 to 11 are explanatory diagrams showing the state of deformation in the analysis of the energy absorption structure parts 40, 40B, 40C, 40D of the embodiment and the first, second, and third comparative examples. FIGS. 12 to 15 are explanatory diagrams showing the state of the resultant acceleration and the HIC value in the analysis of the energy absorption structure parts 40, 40B, 40C, 40D of the embodiment and the first, second, and third comparative examples. In FIGS. 8 to 11, (A1) to (A4) show the state of deformation of the energy absorption structure parts 40, 40B, 40C, 40D at the time of collision of the head dummy, and (B1) to (B4) show the state of deformation of the energy absorption members 10, 10B, 10C, 10D at the time of collision of the head dummy. In FIGS. 8 to 11, (A1) and (B1),..., (A4) and (B4) show the state of deformation at the same timing, respectively. In FIGS. 12 to 15, the resultant acceleration is the combined value of the angular accelerations in three directions orthogonal to each other, specifically, the left-right direction, the up-down direction, and the front-back direction (the direction penetrating the paper surface) in FIG. 7. The HIC value was calculated as the product of the 2.5th power of the average value of the resultant acceleration from time t1 to time t2 and the time interval (t2 - t1) as described in the above-mentioned Document A. The times t1 and t2 were set so that the HIC value became maximum.

[0024] As a result of the analysis of the energy absorption structure 40B of the first comparative example, the energy absorption structure 40B was deformed in the order of FIGS. 9(A1) and 9(B1), FIGS. 9(A2) and 9(B2), FIGS. 9(A3) and 9(B3), FIGS. 9(A4) and 9(B4). In this case, from the start of the collision between the spherical portion 52 and the energy absorption structure 40B, the number of unit units 12 that deform (collapse) into the spherical portion 52 gradually increased. This is because the spread along the extending direction (the front-rear direction and the left-right direction in FIG. 4) of the energy absorption member 10B is restricted by the bottom surface portion 26B. Also, as shown in FIG. 13, the resultant acceleration remained high for a certain period of time from the start of the collision between the spherical portion 52 and the energy absorption structure 40B, that is, the waveform of the resultant acceleration deviated greatly from the ideal waveform (a waveform that is infinite at the initial stage and then decreases exponentially, see Document A), and the HIC value was 1738.

[0025] As a result of the analysis of the energy absorption structure 40C of the second comparative example, the energy absorption structure 40C was deformed in the order of FIGS. 10(A1) and 10(B1), FIGS. 10(A2) and 10(B2), FIGS. 10(A3) and 10(B3), FIGS. 10(A4) and 10(B4). In this case, from the start of the collision between the spherical portion 52 and the energy absorption structure 40C, the number of unit units 12 that come into contact with and deform (collapse) into the spherical portion 52 gradually increased. This is because the spread along the extending direction (the front-rear direction and the left-right direction in FIG. 5) of the energy absorption member 10C is restricted by the fixing of the lower surfaces of all the bottom surface portions 26 of the energy absorption member 10C and the first member 42. Also, as shown in FIG. 14, the resultant acceleration remained high for a certain period of time from the start of the collision between the spherical portion 52 and the energy absorption structure 40B, that is, the waveform of the resultant acceleration deviated greatly from the ideal waveform, and the HIC value was 2316.

[0026] As a result of the analysis of the energy absorption structure 40D of the third comparative example, the energy absorption structure 40D was deformed in the order of FIGS. 11(A1) and 11(B1), FIGS. 11(A2) and 11(B2), FIGS. 11(A3) and 11(B3), and FIGS. 11(A4) and 11(B4). In this case, from the start of the collision between the spherical portion 52 and the energy absorption structure 40C, the number of unit units 12 that come into contact with and deform (collapse) the spherical portion 52 increased gently as compared with the energy absorption member 10C. This is because the spread along the extending direction (the front-rear direction and the left-right direction in FIG. 6) of the energy absorption member 10D is restricted more gently than that of the energy absorption member 10C due to the fixing of the lower surface of a part of the bottom surface portion 26 of the energy absorption member 10D and the first member 42. Further, as shown in FIG. 15, the resultant acceleration remained high for a certain period of time from the start of the collision between the spherical portion 52 and the energy absorption structure 40B, that is, the waveform of the resultant acceleration deviated greatly from the ideal waveform, and the HIC value was 1810.

[0027] As a result of the analysis of the energy absorption structure 40 of the embodiment, the energy absorption structure 40 was deformed in the order of FIGS. 8(A1) and 8(B1), FIGS. 8(A2) and 8(B2), FIGS. 8(A3) and 8(B3), and FIGS. 8(A4) and 8(B4). In this case, from the start of the collision between the spherical portion 52 and the energy absorption structure 40 the number of unit units 12 that come into contact with the spherical portion 52 and collapse while spreading in the extending direction (the front-rear direction and the left-right direction in FIG. 1) of the energy absorption member 10 was suppressed. This is because the energy absorption member 10, unlike the energy absorption members 10B, 10C, 10D is not restricted in its spread along the extending direction. Further, as shown in FIG. 12, the resultant acceleration increased steeply and then decreased rapidly, that is, the waveform of the resultant acceleration approached the ideal waveform as compared with the first, second, and third comparative examples, and the HIC value was 846.5. Therefore, as a result of the analysis, it was confirmed that the HIC value of the energy absorption structure 40 was reduced as compared with the energy absorption structures 40B, 40C, 40D .

[0028] In the energy absorption member 10 of the embodiment described above, the unit units 12 having unevenness are formed in a shape in which a plurality of them are connected along the extending direction of the predetermined surface P0. Further, each unit unit 12 has a rectangular top surface portion 14 that extends along the first surface P1 and has four side portions 16, and four connecting portions 20 that extend from the four side portions 16 and extend so as to be separated from the first surface P1. The four connecting portions 20 and the top surface portion 14 form unevenness. Furthermore, the connecting portions 20 corresponding to each other in two adjacent unit units 12 are connected only to each other (one-to-one) at positions different from the first surface P1. In this way, when the spherical portion 52 of the head dummy 50 collides, the energy absorption member 10 is configured to absorb the collision energy with the spherical portion 52 along with the crushing of the unit unit 12 in contact with the spherical portion 52 and the spread along the extending direction of the predetermined surface P0. Thereby, it is possible to suppress an increase in the number of unit units 12 that come into contact with the spherical portion 52 and deform (crush), and it is possible to suppress the synthetic acceleration from staying high for a certain period of time. As a result, the HIC value can be reduced.

[0029] Further, in the energy absorption member 10, the angle formed by the top surface portion 14 and each first leg portion 22 in each unit unit 12 is an obtuse angle. Thereby, compared with the case where the angle formed by the top surface portion 14 and each first leg portion 22 in each unit unit 12 is a right angle or an acute angle, it is possible to facilitate the spread along the predetermined surface P0 of the unit unit 12 that comes into contact with the spherical portion 52 and deforms (crushes). As a result, it is possible to suppress an increase in the number of unit units 12 that come into contact with the spherical portion 52 and deform (crush).

[0030] In the above-described embodiment, as shown in FIG. 2, in the energy absorption member 10, the predetermined surface P0, the first surface P1, and the second surface P2 are parallel planes to each other, but they may be parallel curved surfaces.

[0031] In the above-described embodiments, as shown in FIGS. 1, 2A, and 2B, in each unit unit 12 of the energy absorption member 10, each connecting portion 20 has a first leg portion 22 and a second leg portion 24, respectively, but the present invention is not limited thereto. FIG. 16 is a perspective view of a modified energy absorption member 110 as viewed from the upper right front. FIG. 17A is a cross-sectional view taken along line A-A of FIG. 16, and FIG. 17B is a cross-sectional view taken along line B-B of FIG. 16. As shown in FIGS. 16, 17A, and 17B, in each unit unit 112 of the modified energy absorption member 110, each connecting portion 120 has only the first leg portion 22 without having the second leg portion 24. In this case, in the front-rear direction and the left-right direction, the connecting portions 120 of two adjacent unit units 112 are connected only to each other (one-to-one) at the ends (lower end portions) on the side opposite to the side portion 16 of the first leg portion 22.

[0032] In the above-described embodiments, as shown in FIGS. 1, 2A, and 2B, each unit unit 12 of the energy absorption member 10 is formed in a rectangular shape in which the top surface portion 14 has four side portions 16, and has four connecting portions 20 extending from the four side portions 16, respectively, but the present invention is not limited thereto. FIG. 18 is a perspective view of a modified energy absorption member 210 as viewed from the upper right front. FIG. 19 is a perspective view of a modified energy absorption member 310 as viewed from the upper right front.

[0033] As shown in FIG. 18, in the modified energy absorption member 210, each unit unit 212 is formed in a triangular shape in which the top surface portion 214 has three side portions 216, and has three connecting portions 220 extending from the three side portions 216, respectively. Each connecting portion 220 has a first leg portion 222 and a second leg portion 224, respectively, in the same manner as the connecting portion 20 having the first leg portion 22 and the second leg portion 24. The connecting portions 220 of two adjacent unit units 212 are connected only to each other (one-to-one) at the ends on the side opposite to the first leg portion 222 of the second leg portion 224.

[0034] As shown in FIG. 19, in the energy absorption member 310 of the modified example, each unit unit 312 is formed in a hexagonal shape in which the top surface portion 314 has six side portions 316, and has six connecting portions 320 extending from the six side portions 316, respectively. Each connecting portion 320 has a first leg portion 322 and a second leg portion 324, just as the connecting portion 20 has the first leg portion 22 and the second leg portion 24. The connecting portions 320 of two adjacent unit units 312 are connected only to each other (one-to-one) at the ends on the side opposite to the first leg portion 322 of the second leg portion 324.

[0035] In the energy absorption member 210, each connecting portion 220 of each unit unit 212 has only the first leg portion 222 without having 224, and the connecting portions 220 of two adjacent unit units 212 may be connected only to each other (one-to-one) at the ends (lower end portions) on the side opposite to the side portion 216 of the first leg portion 222. The same applies to the energy absorption member 310.

[0036] In the above-described embodiment, although not described, the energy absorption member 10 may be a predetermined low-friction member. Here, the predetermined low-friction member includes a member manufactured from a predetermined low-friction material and a member having a predetermined low-friction treatment applied to its surface. Examples of the predetermined low-friction material include resins with a low friction coefficient (e.g., polytetrafluoroethylene, polyacetal, monomer cast polyamide, ultra-high molecular weight polyethylene, etc.). Examples of the predetermined low-friction treatment include a treatment of applying lubricating oil to the surface of the energy absorption member 10, a treatment of coating the surface of the energy absorption member 10 by polytetrafluoroethylene processing, etc. Thereby, when used as the energy absorption structure portion 40 including the energy absorption member 10, the first member 42, and the second member 44, the frictional force between the energy absorption member 10, the first member 42, and the second member 44 is further reduced, and smoother deformation of the energy absorption member 10 becomes possible. The same applies to the energy absorption members 110, 210, and 310.

[0037] In addition, in the energy absorption structure portion 40, at least one of the energy absorption member 10, the first member 42, and the second member 44 may be a predetermined low-friction member. Even in this case, the frictional force between the energy absorption member 10, the first member 42, and the second member 44 is further reduced, and smoother deformation of the energy absorption member 10 becomes possible. The same applies to the energy absorption structure portion including any one of the energy absorption members 110, 210, and 310, the first member 42, and the second member 44.

[0038] Furthermore, in the energy absorption structure portion 40, a predetermined low-friction member may be disposed between the energy absorption member 10 and the first member 42, and between the energy absorption member 10 and the second member 44, respectively. The predetermined low-friction member in this case may be a thin-film (film-like) member made of the above-described predetermined low-friction material, or may be a thin-film member having a predetermined low-friction treatment applied to its surface. Even in this case, the frictional force between the energy absorption member 10, the first member 42, and the second member 44 is further reduced, and smoother deformation of the energy absorption member 10 becomes possible. The same applies to the energy absorption structure portion including any one of the energy absorption members 110, 210, and 310, the first member 42, and the second member 44.

[0039] In the above-described embodiment, the energy absorption member 10 is assumed to be an integrally formed product, but it may be configured by joining a plurality of parts to each other. The same applies to the energy absorption members 110, 210, and 310.

[0040] It should be noted that the correspondence relationship between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems is an example for specifically explaining the mode for carrying out the invention described in the column of means for solving the problems in the embodiment. Therefore, it does not limit the elements of the invention described in the column of means for solving the problems. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the column of means for solving the problems.

[0041] As described above, the embodiments for carrying out the present disclosure have been described using the embodiments. However, the present disclosure is not limited to such embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist thereof.

[0042] [Appendix] [1] The energy absorption member of the present disclosure is an energy absorption member having a shape in which a plurality of unit units having irregularities are connected along the extending direction of a predetermined surface. When a spherical portion of an external object collides, the energy absorption member is configured to absorb the collision energy with the spherical portion along with the crushing of the unit unit in contact with the spherical portion and the spreading along the extending direction of the predetermined surface. The gist is that.

[0043] In the energy absorption member of the present disclosure, when a spherical portion of an external object collides, the unit unit in contact with the spherical portion collapses and spreads along the extending direction of the predetermined surface. As a result, it is possible to suppress an increase in the number of unit units that deform in contact with the spherical portion, and to suppress the synthetic acceleration from staying high for a certain period of time. As a result, the HIC value can be reduced. Here, the predetermined surface may be a flat surface or a curved surface.

[0044] [2] In the energy absorption member described above (the energy absorption member described in [1]), the unit unit has a polygonal top surface portion that extends along a first surface and has a plurality of side portions, and extends from the plurality of side portions so as to be separated from the first surface. And a plurality of connecting portions that extend, and the unevenness is formed by the plurality of connecting portions and the top surface portion, and the connecting portions corresponding to each other of two adjacent unit units may be connected to each other only at a position different from the first surface. Here, the first surface may be parallel to the predetermined surface.

[0045] [3] In the above-described energy absorption member (the energy absorption member described in [2]), the angles formed between the top surface portion in the unit unit and each of the connecting portions may all be obtuse angles. By doing so, it becomes easier to spread along a predetermined surface of the unit unit that contacts and deforms against the spherical portion, and it is possible to suppress an increase in the unit unit that contacts and deforms against the spherical portion.

[0046] [4] In the above-described energy absorption member (the energy absorption member described in [2] or [3]), each of the connecting portions of the unit unit includes a first leg portion that extends from the corresponding side portion and extends so as to be spaced apart from the first surface, and a second leg portion that extends from an end portion of the first leg portion on the side opposite to the side portion and extends along a second surface different from the first surface toward the connecting portion side of the adjacent unit unit. The connecting portions corresponding to each other in two adjacent unit units may be connected only to each other by the second leg portions. Here, the second surface may be parallel to the predetermined surface and / or the first surface.

[0047] [5] In the above-described energy absorption member (the energy absorption member described in any one of [2] to [4]), two adjacent unit units may be arranged such that the side portions facing each other are parallel.

[0048] [6] In the above-described energy absorption member (the energy absorption member described in any one of [2] to [5]), the polygon may be any one of a triangle, a quadrilateral, and a hexagon.

[0049] [7] In the above-described energy absorption member (the energy absorption member described in any one of [2] to [5]), the polygon is a quadrilateral, and a plurality of the unit units are arranged such that the top surface portions of the respective unit units are arranged at intervals in a first direction and a second direction orthogonal to each other on the first surface, and two adjacent unit units in the first direction are connected and two adjacent unit units in the second direction are also connected.

[0050] [8] In the energy absorption member described above (the energy absorption member described in any one of [1] to [7]), the energy absorption member may be an integrally formed product.

[0051] [9] In the energy absorption member described above (the energy absorption member described in any one of [1] to [8]), the energy absorption member may be disposed between the first member and the second member so as to allow expansion along the extending direction of the surface of the energy absorption member.

[0052]

[10] In the energy absorption member described above (the energy absorption member described in [9]), the energy absorption member may be a predetermined low-friction member. By doing so, the frictional force between the energy absorption member and the first member and the second member can be further reduced, and smoother deformation of the energy absorption member becomes possible.

[0053]

[11] The gist of the energy absorption structure part of the present disclosure is that it includes the energy absorption member described above (the energy absorption member described in any one of [1] to [8]), and the first member and the second member that are disposed on both sides sandwiching the energy absorption member and allow expansion along the extending direction of the surface of the energy absorption member.

[0054] In the energy absorption structure part of the present disclosure, since it includes the energy absorption member described above, it exhibits the same effects as those exhibited by the energy absorption member described above, for example, the effect of reducing the HIC value.

[0055]

[12] In the energy absorption structure part described above (the energy absorption structure part described in

[11] ), at least one of the energy absorption member, the first member, and the second member may be a predetermined low-friction member. By doing so, the frictional force between the energy absorption member and the first member and the second member can be further reduced, and smoother deformation of the energy absorption member becomes possible.

[0056]

[13] In the above-described energy absorption structure part (the energy absorption structure part described in

[11] ), a predetermined low-friction member may be further provided between the energy absorption member and the first member, and between the energy absorption member and the second member. By doing so, the frictional force between the energy absorption member and the first and second members can be further reduced, enabling smoother deformation of the energy absorption member.

Explanation of Reference Numerals

[0057] 10, 110, 210, 310 energy absorption members, 12, 112, 212, 312 unit units, 14, 214, 314 top surface parts, 20, 120, 220, 320 connecting parts, 22 first leg parts, 24 second leg parts.

Claims

1. An energy absorbing structure including an energy absorbing member having a shape in which a plurality of unit units having projections and recesses are connected along an extending direction of a predetermined surface, and a first member and a second member disposed on either side of the energy absorbing member, the first member and the second member are allowed to expand along two directions perpendicular to each other in an extension direction of the predetermined surface of the energy absorbing member, The energy absorbing member is configured to absorb the collision energy with the spherical portion of an external object by crushing the unit unit in contact with the spherical portion and expanding along the two directions when the unit unit collides with the spherical portion. Energy absorbing structure.

2. 2. The energy absorbing structure of claim 1, The unit has a polygonal top surface portion extending along a first surface and having a plurality of sides, and a plurality of connecting portions extending from the plurality of sides and extending away from the first surface, and the unevenness is formed by the plurality of connecting portions and the top surface portion, The connecting portions of the two adjacent units corresponding to each other are connected to each other only at positions different from the first surface. Energy absorbing structure.

3. 3. The energy absorbing structure of claim 2, The angles formed between the top surface portion of the unit and each of the connecting portions are all obtuse angles. Energy absorbing structure.

4. 4. The energy absorbing structure according to claim 2 or 3, The connecting portion of each of the unit units has a first leg portion extending from the corresponding side portion and extending away from the first surface, and a second leg portion extending from an end portion of the first leg opposite the side portion and extending along a second surface different from the first surface toward the connecting portion of the adjacent unit unit, The corresponding connecting portions of two adjacent units are connected to each other only via the second leg portions. Energy absorbing structure.

5. 4. The energy absorbing structure according to claim 2 or 3, Two adjacent units are arranged such that the sides facing each other are parallel to each other. Energy absorbing structure.

6. 4. The energy absorbing structure according to claim 2 or 3, The polygonal shape is any one of a triangular shape, a rectangular shape, and a hexagonal shape. Energy absorbing structure.

7. 4. The energy absorbing structure according to claim 2 or 3, The polygonal shape is a quadrilateral shape, The plurality of unit units are arranged such that the top surface portions of the respective unit units are spaced apart from each other in a first direction and a second direction perpendicular to each other on the first surface, and two of the unit units adjacent to each other in the first direction are connected to each other, and two of the unit units adjacent to each other in the second direction are connected to each other. Energy absorbing structure.

8. 4. An energy absorbing structure according to any one of claims 1 to 3, comprising: The energy absorbing member is an integrally molded product. Energy absorbing structure.

9. 4. An energy absorbing structure according to any one of claims 1 to 3, comprising: The energy absorbing member is a predetermined low friction member. Energy absorbing structure.

10. 4. An energy absorbing structure according to any one of claims 1 to 3, comprising: At least one of the energy absorbing member, the first member, and the second member is a predetermined low friction member. Energy absorbing structure.

11. 4. An energy absorbing structure according to any one of claims 1 to 3, comprising: a predetermined low-friction member provided between the energy absorbing member and the first member, and between the energy absorbing member and the second member; The energy absorbing structure further comprises:

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