Energy absorption member and energy absorption structure

Abstract

This energy absorption member has a shape in which a plurality of individual units, each having a projection and a recess, are connected along an extending direction of a predetermined surface. The energy absorption member is configured such that, when a spherical part of an external object collides with the energy absorption member, the individual units that are in contact with the spherical part collapse and expand along the extending direction of the predetermined surface to absorb energy of the collision with the spherical part.

Description

Energy absorbing member and energy absorbing structure

[0001] The present disclosure relates to energy absorbing members and energy absorbing structures.

[0002] Conventionally, an energy absorbing member has been proposed that is interposed between a body component 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 ceiling and four side walls, is hollow, and is in the shape of a truncated quadrangular pyramid with an open base. Furthermore, in the structure, the thickness of a corner connecting two adjacent side walls is thinner than the thickness of each side wall body. In this energy absorbing member, when an impact load is applied, the two adjacent side walls of the structure are torn apart, and each side wall buckles independently.

[0003] Also proposed is an energy absorbing member with multiple protrusions arranged radially (see Patent Document 2). Here, each protrusion has a hexagonal top surface and side pieces extending downward from each side edge of the top surface, with a base portion having a hexagonal shape similar to the top surface. The protrusions are connected to adjacent protrusions by connecting pieces extending from each base edge of the base portion. The connecting pieces are fixed to the roof reinforcement by welding or adhesive. In this energy absorbing member, a compressive load is transmitted from the top surface of each protrusion to each side piece, causing buckling deformation in each side piece, then transmitted from each side piece to each connecting piece, inducing bending deformation, and further transmitted radially to each protrusion via each connecting piece, thereby absorbing the load.

[0004] Japanese Patent No. 3654339 Japanese Patent Application Laid-Open No. 2014-105818

[0005] Incidentally, the Head Injury Criterion (HIC) value is sometimes used as one of the performance evaluations of energy absorbing members. The inventors have confirmed through analysis and other means that the energy absorbing members of Patent Documents 1 and 2 tend to have a relatively high HIC value when colliding with the spherical portion of an external object (e.g., a head dummy (FMH: Free Motion Head Form)). This is thought to be because, over a certain period of time after the start of the collision between the spherical portion and the energy absorbing member, the number of structures (see Patent Document 1) and protrusions (see Patent Document 2) that contact and deform with the spherical portion gradually increases. This makes it easy for the resultant acceleration to remain high for a certain period of time. In other words, the waveform of the resultant acceleration tends to deviate significantly from the ideal waveform (which is initially infinite and then exponentially decreases; see Document A). In light of this, there is a need for an energy absorbing member that can reduce the HIC value. Document A: Mizuno Koji, "Automobile Crash Safety," Nagoya University Press, February 29, 2012, pp. 14-16

[0006] The energy absorbing member and energy absorbing structure of the present disclosure are primarily intended to have a configuration that can reduce the HIC value.

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

[0008] The energy absorbing member of the present disclosure is an energy absorbing member having a shape in which a plurality of unit units having unevenness are connected along the extension direction of a specified surface, and the energy absorbing member is configured such that when a spherical portion of an external object collides with the energy absorbing member, the unit units in contact with the spherical portion crush and expand along the extension direction of the specified surface to absorb the collision energy with the spherical portion.

[0009] In the energy absorbing member of the present disclosure, when a spherical portion of an external object collides with the energy absorbing member, the units in contact with the spherical portion are crushed and expand along the extension direction of the predetermined surface. This reduces the HIC value. The inventors have confirmed this through analysis. Here, the predetermined surface may be a flat surface or a curved surface.

[0010] 1 is a perspective view of an energy absorbing member of an embodiment, as seen from the upper right front. FIG. 1 is a cross-sectional view taken along line A-A in FIG. 1 ; FIG. 1 is a cross-sectional view taken along line B-B in FIG. 1 ; FIG. 2 is an explanatory diagram showing an example of use of an energy absorbing member of an embodiment; FIG. 3 is a perspective view of an energy absorbing member of a first comparative example, as seen from the upper right front. FIG. 4 is a perspective view of an energy absorbing member of a second comparative example, as seen from the lower left rear. FIG. 5 is a perspective view of an energy absorbing member of a second comparative example, as seen from the lower left rear. FIG. 6 is an explanatory diagram showing the state of analysis of an energy absorbing structure of an embodiment; FIG. 7 is an explanatory diagram showing the state of shape in the analysis of an energy absorbing structure of an embodiment; FIG. 8 is an explanatory diagram showing the state of shape in the analysis of an energy absorbing structure of a first comparative example; FIG. 9 is an explanatory diagram showing the state of shape in the analysis of an energy absorbing structure of a second comparative example; FIG. 10 is an explanatory diagram showing the state of shape in the analysis of an energy absorbing structure of a third comparative example; FIG. 11 is an explanatory diagram showing the state of resultant acceleration and HIC value in the analysis of an energy absorbing structure of an embodiment; FIG. 12 is an explanatory diagram showing the state of resultant acceleration and HIC value in the analysis of an energy absorbing structure of a first comparative example; FIG. 13 is an explanatory diagram showing the state of resultant acceleration and HIC value in the analysis of an energy absorbing structure of a second comparative example. 16 is an explanatory diagram showing the state of resultant acceleration and HIC value in the analysis of the energy absorption structure of the third comparative example. FIG. 17 is a perspective view of the energy absorption member of the modified example, seen from the upper right front. FIG. 18 is a cross-sectional view taken along line A-A in FIG. 16. FIG. 19 is a cross-sectional view taken along line B-B in FIG. 16. FIG. 19 is a perspective view of the energy absorption member of the modified example, seen from the upper right front. FIG. 20 is a perspective view of the energy absorption member of the modified example, seen from the upper right front.

[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 an energy absorbing member 10 according to an embodiment of the present disclosure, as viewed from the upper right front. Fig. 2A is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 2B is a cross-sectional view taken along line B-B in Fig. 1. The front-rear direction (first direction), left-right direction (second direction), and up-down direction of the energy absorbing member 10 are as shown in Figs. 1, 2A, and 2B.

[0012] The energy absorbing member 10 of the embodiment is an integrally molded product, and is formed, 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 Figures 1, 2A, and 2B, the energy absorbing member 10 is formed in a shape in which a plurality of units 12 having projections and recesses are connected along the extension direction of a predetermined plane P0. The predetermined plane P0 is a flat surface extending in the front-rear and left-right directions (see Figures 2A and 2B).

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

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

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

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

[0017] Next, an example of use of the energy absorbing member 10 according to the embodiment will be described with reference to FIG. 3 . As shown in the figure, the energy absorbing member 10 according to the embodiment is used as an energy absorbing structure 40. The energy absorbing structure 40 is configured by disposing the energy absorbing member 10 between a first member 42 and a second member 44, with the second leg portion 24 facing the first member 42 and the top surface portion 14 facing the second member 44. The first member 42 and the second member 44 are both plate-shaped and disposed facing each other with a gap therebetween. Note that the shape of the first member 42 need not be plate-shaped, as long as the surface facing the energy absorbing member 10 is flat. Various methods for disposing the energy absorbing member 10 are conceivable. For example, when the first member 42, the second member 44, and the energy absorbing member 10 are disposed so as to extend vertically, the energy absorbing member 10 may be suspended from a third member disposed above them. Furthermore, when the first member 42, the second member 44, and the energy absorbing member 10 are arranged so as to extend horizontally, the energy absorbing member 10 may be placed unfixed on either the first member 42 or the second member 44 which is below the energy absorbing member 10, or may be suspended from the member above the energy absorbing member 10 so as not to hinder deformation of the energy absorbing member 10. In other words, it is sufficient that the energy absorbing member 10 is arranged between the first member 42 and the second member 44 so as not to hinder deformation of the energy absorbing member 10. When the energy absorbing member 10 is used in a vehicle, examples of combinations of the first member 42 and the second member 44 include a pillar and a pillar garnish, a suspension tower and an outer hood, and a roof reinforcement and a roof lining.

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

[0019] Figure 4 is a perspective view of an energy absorbing member 10B of the first comparative example, viewed from the upper right front. As shown in Figure 4, the energy absorbing member 10B has a shape in which the multiple bottom surface portions 26 of the energy absorbing member 10 of the embodiment are connected in the front-rear and left-right directions. Hereinafter, the entire portion in which the multiple bottom surface portions 26 are connected in the front-rear and left-right directions will be referred to as the bottom surface portion 26B. In each unit 12, the four connecting portions 20 are connected to one another by the bottom surface portions 26B.

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

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

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

[0023] Figures 8 to 11 are explanatory diagrams showing the deformation behavior of the energy absorption structures 40, 40B, 40C, and 40D in the embodiment and the first, second, and third comparative examples. Figures 12 to 15 are explanatory diagrams showing the resultant acceleration behavior and HIC values ​​in the analysis of the energy absorption structures 40, 40B, 40C, and 40D in the embodiment and the first, second, and third comparative examples. In Figures 8 to 11, (A1) to (A4) show the deformation behavior of the energy absorption structures 40, 40B, 40C, and 40D during the impact of the head dummy, and (B1) to (B4) show the deformation behavior of the energy absorbing members 10, 10B, 10C, and 10D during the impact of the head dummy. In Figures 8 to 11, (A1), (B1), ..., (A4), and (B4) each show the deformation behavior at the same timing. 12 to 15, the resultant acceleration is a composite value of angular accelerations in three mutually orthogonal directions, specifically, the left-right direction, the up-down direction, and the front-to-back direction (the direction penetrating the paper) in FIG. 7. As described in the above-mentioned literature A, the HIC value was calculated as the product of the 2.5th power of the average of the resultant acceleration from time t1 to time t2 and the time interval (t2 - t1). Times t1 and t2 were set so that the HIC value was maximized.

[0024] Analysis of the energy absorption structure 40B of the first comparative example revealed that the energy absorption structure 40B deformed in the order shown in Figures 9(A1) and 9(B1), 9(A2) and 9(B2), 9(A3) and 9(B3), and 9(A4) and 9(B4). In this case, the number of units 12 deformed (crushed) into the spherical portion 52 gradually increased from the start of the collision between the spherical portion 52 and the energy absorption structure 40B. This was because the bottom surface 26B restricted the expansion of the energy absorption member 10B along its extension direction (the front-to-back and left-to-right directions in Figure 4). Furthermore, as shown in Figure 13, the resultant acceleration remained high for a certain period of time after the start of the collision between the spherical portion 52 and the energy absorption structure 40B. That is, the waveform of the resultant acceleration significantly deviated from the ideal waveform (an initial infinite value followed by an exponential decrease; see Reference A), resulting in an HIC value of 1738.

[0025] As a result of the analysis of the energy absorption structure 40C of the second comparative example, the energy absorption structure 40C deformed in the order of Figures 10(A1) and 10(B1), 10(A2) and 10(B2), 10(A3) and 10(B3), and 10(A4) and 10(B4). In this case, the number of units 12 that came into contact with the spherical portion 52 and deformed (crushed) gradually increased from the start of the collision between the spherical portion 52 and the energy absorption structure 40C. This is because the fixation of the lower surfaces of all the bottom portions 26 of the energy absorption member 10C to the first member 42 restricts the expansion of the energy absorption member 10C along its extension direction (the front-rear and left-right directions in Figure 5). Furthermore, as shown in Figure 14, the resultant acceleration remained high for a certain period of time after the start of the collision between the spherical portion 52 and the energy absorption structure 40B, i.e., the waveform of the resultant acceleration deviated significantly from the ideal waveform, and the HIC value was 2316.

[0026] As a result of analysis of the energy-absorbing structure 40D of the third comparative example, the energy-absorbing structure 40D deformed in the order of Figures 11(A1) and 11(B1), 11(A2) and 11(B2), 11(A3) and 11(B3), and 11(A4) and 11(B4). In this case, from the start of the collision between the spherical portion 52 and the energy-absorbing structure 40C, the number of units 12 that came into contact with the spherical portion 52 and deformed (crushed) increased more gradually than in the energy-absorbing member 10C. This is because the fixation of the lower surface of a part of the bottom portion 26 of the energy-absorbing member 10D to the first member 42 loosely restricts the expansion of the energy-absorbing member 10D along its extension direction (the front-rear and left-right directions in Figure 6) compared to the energy-absorbing member 10C. Furthermore, as shown in Figure 15, the resultant acceleration remained high for a certain period of time after the start of the collision between the spherical portion 52 and the energy absorption structure 40B, i.e., the waveform of the resultant acceleration deviated significantly from the ideal waveform, and the HIC value was 1810.

[0027] As a result of analysis of the energy absorption structure 40 of the embodiment, the energy absorption structure 40 deformed in the order of Figures 8(A1) and 8(B1), 8(A2) and 8(B2), 8(A3) and 8(B3), and 8(A4) and 8(B4). In this case, from the start of the collision between the spherical portion 52 and the energy absorption structure 40C, the units 12 that contacted the spherical portion 52 expanded in the extension direction of the energy absorbing member 10D (the front-rear and left-right directions in Figure 1) while being crushed, thereby suppressing an increase in the number of units 12 that were deformed (crushed) upon contact with the spherical portion 52. This is because, unlike the energy absorbing members 10B, 10C, and 10C, the expansion of the energy absorbing member 10D in the extension direction is not restricted. 12, the resultant acceleration increased sharply and then decreased rapidly, i.e., the waveform of the resultant acceleration approached the ideal waveform compared to 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 compared to the energy absorption structures 40B, 40C, and 40C.

[0028] In the energy absorbing member 10 of the embodiment described above, a plurality of unit units 12 having irregularities are connected together along the extension direction of the predetermined plane P0. Each unit unit 12 has a rectangular top surface 14 that extends along the first plane P1 and has four sides 16, and four connecting portions 20 that extend from the four sides 16 and away from the first plane P1, forming irregularities. The four connecting portions 20 and the top surface 14 form irregularities. The corresponding connecting portions 20 of two adjacent unit units 12 are connected only to each other (one-to-one) at positions different from the first plane P1. In this way, the energy absorbing member 10 is configured to absorb the collision energy with the spherical portion 52 of the head dummy 50 when the spherical portion 52 collides with the unit unit 12 by crushing the unit units 12 in contact with the spherical portion 52 and expanding along the extension direction of the predetermined plane P0. This prevents an increase in the number of units 12 that come into contact with the spherical portion 52 and are deformed (crushed), and prevents the resultant acceleration from remaining high for a certain period of time, thereby reducing the HIC value.

[0029] Furthermore, in the energy absorbing member 10, the angle formed between the top surface 14 of each unit 12 and each first leg 22 is an obtuse angle. This makes it easier for the unit 12 that comes into contact with the spherical portion 52 and deforms (crushes) to spread along the predetermined plane P0, compared to when the angle formed between the top surface 14 of each unit 12 and each first leg 22 is a right angle or an acute angle. As a result, it is possible to prevent an increase in the number of unit 12 that comes into contact with the spherical portion 52 and deforms (crushes).

[0030] In the above-described embodiment, as shown in FIG. 2, the predetermined surface P0, the first surface P1, and the second surface P2 of the energy absorbing member 10 are flat surfaces parallel to one another, but they may also be curved surfaces parallel to one another.

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

[0032] In the above-described embodiment, as shown in Figures 1, 2A, and 2B, each unit 12 of the energy absorbing member 10 has a top surface 14 formed in a quadrangular shape with four sides 16 and has four connecting portions 20 extending from each of the four sides 16, but this is not limiting. Figure 18 is a perspective view of a modified energy absorbing member 210 as viewed from the upper right front. Figure 19 is a perspective view of a modified energy absorbing member 310 as viewed from the upper right front.

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

[0034] 19 , in the modified energy absorbing member 310, each unit 312 has a top surface 314 formed in a hexagonal shape having six sides 316, and has six connecting portions 320 extending from the six sides 316. Each connecting portion 320 has a first leg 322 and a second leg 324, similar to how connecting portion 20 has first leg 22 and second leg 24. The connecting portions 320 of two adjacent units 312 are connected to each other only (one-to-one) at the ends of the second legs 324 opposite to the first legs 322.

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

[0036] Although not described in the above-described embodiment, the energy absorbing member 10 may be a predetermined low-friction member. Here, the predetermined low-friction member includes a member made of a predetermined low-friction material or a member whose surface has been subjected to a predetermined low-friction treatment. 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 applying a lubricant to the surface of the energy absorbing member 10 or coating the surface of the energy absorbing member 10 with polytetrafluoroethylene. This further reduces the friction between the energy absorbing member 10 and the first and second members 42 and 44, enabling smoother deformation of the energy absorbing member 10. The same applies to the energy absorbing members 110, 210, and 310.

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

[0038] Furthermore, in the energy absorbing structure 40, predetermined low-friction members may be disposed between the energy absorbing member 10 and the first member 42, and between the energy absorbing member 10 and the second member 44. In this case, the predetermined low-friction members may be thin-film-like members made of the predetermined low-friction material described above, or thin-film-like members whose surfaces have been subjected to a predetermined low-friction treatment. Even in this case, the frictional force between the energy absorbing member 10 and the first member 42 and the second member 44 is further reduced, allowing for smoother deformation of the energy absorbing member 10. The same applies to energy absorbing structures including any of the energy absorbing members 110, 210, and 310 and the first member 42 and the second member 44.

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

[0040] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0041] The above describes the forms for implementing the present disclosure using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be implemented in various forms within the scope that does not deviate from the gist of the present disclosure.

[0042] [Notes] [1] The energy absorbing member of the present disclosure is an energy absorbing member having a shape in which a plurality of unit units having unevenness are connected along the extension direction of a predetermined surface, and the energy absorbing member is configured so that when a spherical portion of an external object collides with the energy absorbing member, the unit units in contact with the spherical portion are crushed and expand along the extension direction of the predetermined surface to absorb the collision energy with the spherical portion.

[0043] In the energy absorbing member of the present disclosure, when a spherical portion of an external object collides with the energy absorbing member, the units in contact with the spherical portion are crushed and expand along the extension direction of the predetermined surface. This prevents an increase in the number of units that are deformed by contact with the spherical portion, and prevents the resultant acceleration from remaining 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 above-described energy absorbing member (the energy absorbing member described in [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, the unevenness may be formed by the plurality of connecting portions and the top surface portion, and the corresponding connecting portions of two adjacent unit units may be connected only to each other at a position different from the first surface. Here, the first surface may be parallel to a predetermined plane.

[0045] [3] In the energy absorbing member described in [2], the angles formed between the top surface portion of each unit and the connecting portion of each unit may be obtuse angles. This makes it easier for the unit to expand along the predetermined plane when it comes into contact with the spherical portion and deforms, and prevents an increase in the number of unit units that come into contact with the spherical portion and deforms.

[0046] [4] In the above-mentioned energy absorbing member (the energy absorbing member described in [2] or [3]), the connecting portion of each of the unit units may have a first leg extending from the corresponding side portion and extending away from the first surface, and a second leg extending from an end 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, and the corresponding connecting portions of two adjacent unit units may be connected to each other only by the second leg. Here, the second surface may be parallel to a predetermined surface and / or the first surface.

[0047] [5] In the above-mentioned energy absorption member (the energy absorption member described in any one of [2] to [4]), two adjacent units may be arranged so that the opposing sides are parallel to each other.

[0048] [6] In the above-mentioned energy absorbing member (the energy absorbing member according to any one of [2] to [5]), the polygonal shape may be any one of a triangular shape, a rectangular shape, and a hexagonal shape.

[0049] [7] In the above-mentioned energy absorption member (the energy absorption member described in any one of [2] to [5]), the polygonal shape may be a quadrilateral shape, and the plurality of unit units may be arranged so that the top surface portions of the respective unit units are spaced apart in a first direction and a second direction that are perpendicular to each other on the first surface, and two adjacent unit units in the first direction may be connected, and two adjacent unit units in the second direction may be connected.

[0050] [8] In the above-mentioned energy absorbing member (the energy absorbing member according to any one of [1] to [7]), the energy absorbing member may be an integrally molded product.

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

[0052]

[10] In the energy absorbing member described in [9], the energy absorbing member may be a predetermined low-friction member. This further reduces the frictional force between the energy absorbing member and the first and second members, allowing for smoother deformation of the energy absorbing member.

[0053]

[11] The energy absorption structure of the present disclosure comprises the above-mentioned energy absorption member (the energy absorption member described in any one of [1] to [8]), and a first member and a second member arranged on either side of the energy absorption member and allowing the energy absorption member to expand along the extension direction of the surface.

[0054] The energy absorbing structure of the present disclosure includes the above-described energy absorbing member, and therefore achieves the same effects as those achieved by the above-described energy absorbing member, such as the effect of being able to reduce the HIC value.

[0055]

[12] In the energy absorbing structure described in

[11] , at least one of the energy absorbing member and the first and second members may be a predetermined low-friction member. This reduces the friction between the energy absorbing member and the first and second members, allowing for smoother deformation of the energy absorbing member.

[0056]

[13] The above-mentioned energy absorbing structure (the energy absorbing structure described in

[11] ) may further include 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. This further reduces the friction force between the energy absorbing member and the first member and between the energy absorbing member and the second member, and enables smoother deformation of the energy absorbing member.

[0057] 10, 110, 210, 310 Energy absorbing member, 12, 112, 212, 312 Unit, 14, 214, 314 Top surface portion, 20, 120, 220, 320 Connecting portion, 22 First leg portion, 24 Second leg portion.

Claims

1. An energy absorbing member having a shape in which a plurality of unitary units having concave and convex portions are connected along the extension direction of a specified surface, wherein the energy absorbing member is configured such that when a spherical portion of an external object collides with the energy absorbing member, the unitary units in contact with the spherical portion crush and expand along the extension direction of the specified surface to absorb the collision energy with the spherical portion.

2. An energy absorbing member as set forth in claim 1, wherein the unit has a polygonal top surface portion that extends along a first surface and has a plurality of sides, and a plurality of connecting portions that extend from the plurality of sides and away from the first surface, the plurality of connecting portions and the top surface portion forming the unevenness, and the corresponding connecting portions of two adjacent unit units are connected only to each other at positions different from the first surface.

3. An energy absorbing member according to claim 2, wherein the angles formed between the top surface of each of the units and each of the connecting portions are all obtuse angles.

4. An energy absorbing member as set forth in claim 2 or 3, wherein the connecting portion of each of the unit units has a first leg extending from the corresponding side portion and extending away from the first surface, and a second leg extending from an end of the first leg opposite the side portion and extending toward the connecting portion of the adjacent unit unit along a second surface different from the first surface, and the corresponding connecting portions of two adjacent unit units are connected to each other only by the second legs.

5. An energy absorbing member according to claim 2 or 3, wherein two adjacent units are arranged so that the opposing sides are parallel to each other.

6. An energy absorbing member according to claim 2 or 3, wherein the polygonal shape is one of a triangular shape, a rectangular shape, and a hexagonal shape.

7. An energy absorbing member according to claim 2 or 3, wherein the polygonal shape is a quadrangle, and the plurality of unit units are arranged so that the top surface portions of the respective unit units are spaced apart in a first direction and a second direction that are perpendicular 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 connected.

8. An energy absorbing member according to any one of claims 1 to 3, wherein the energy absorbing member is an integrally molded product.

9. An energy absorbing member according to any one of claims 1 to 3, wherein the energy absorbing member is disposed between a first member and a second member so as to allow expansion along the extending direction of the surface of the energy absorbing member.

10. An energy absorbing member according to claim 9, wherein said energy absorbing member is a predetermined low friction member.

11. An energy absorbing structure comprising: an energy absorbing member according to any one of claims 1 to 3; and a first member and a second member arranged on either side of the energy absorbing member, which allow the energy absorbing member to expand in the extension direction of the surface of the energy absorbing member.

12. An energy absorbing structure according to claim 11, wherein at least one of the energy absorbing member and the first and second members is a predetermined low friction member.

13. An energy absorbing structure according to claim 11, further comprising predetermined low-friction members provided between the energy absorbing member and the first member, and between the energy absorbing member and the second member.

Images