JP2008044399A - Shock absorbing material of vehicular shock absorbing bumper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shock absorbing material of a vehicular shock absorbing bumper capable of obtaining an excellent shock energy absorbing property which prevents damage when contacting an article, a pedestrian, and the like. <P>SOLUTION: In the shock absorbing material 10 made from foam resin disposed between a front surface 3 of a bumper beam 2 extending in a vehicular width direction and a bumper face 5, a plurality of first front side hollow holes 15 of a bottomed hole shape arranged at intervals in the vehicular width direction and opening to a front surface 11 and first rear side hollow holes 16 of a bottomed hole shape arranged at intervals in the vehicular width direction and opening to a rear surface 14; and a plurality of second front side hollows 17 of a bottomed hole shape arranged at intervals in the vehicular width direction and opening to a front surface 11 and second rear side hollow holes 18 of a bottomed hole shape arranged at intervals in the vehicular width direction and opening to a rear surface 14. The first front side hollow holes 15 and the first rear side hollow holes 16, and the second front side hollow holes 17 and the second rear side hollow holes 18 are alternately arranged so as to be offset in the vehicular width direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an impact absorbing material, and more particularly to an impact absorbing material for an impact absorbing bumper for a vehicle.

  The shock absorbing bumper for a vehicle plays a role of mitigating the impact and preventing the vehicle body from being damaged when the vehicle comes into contact with an external object or a pedestrian. On the other hand, in recent years, bumpers have been developed with an emphasis on pedestrian protection, and the bumpers are required to suppress damage to pedestrians as much as possible. In other words, the shock absorbing bumper is required to have a shock energy absorption property that does not cause damage to the pedestrian's leg so that it cannot be recovered even when it comes into contact with the pedestrian at a relatively high speed. Is done.

  This type of shock absorbing bumper includes, for example, a bumper beam 101 that is disposed at the front of the vehicle body and extends in the vehicle width direction as shown in a cross section in FIG. 11, and a front surface 101 a of the bumper beam 101 along the vehicle width direction. The shock absorbing material 102 disposed on the bumper face 103 and the bumper face 103 covering the shock absorbing material 102 are mainly formed. The shock absorbing material 102 is formed of a foamed resin such as polypropylene, and the bumper face 103 is formed of a resin such as polyurethane or polypropylene.

  Here, the deformation resistance against the impact of the shock absorbing material 102 made of foamed resin such as polypropylene is substantially determined by the foaming ratio of the foamed resin and the deformation stroke amount of the shock absorbing material 102, particularly when the foaming ratio of the foamed resin is low. There is a tendency for the initial deformation drag to rise rapidly and become excessive. However, the expansion ratio of the foamed resin is limited by productivity and marketability, and the desired required deformation resistance characteristic may not be obtained. For example, even if a foamed resin having the maximum expansion ratio that can be produced is used as the shock absorbing material 102, the deformation resistance is high, the initial resistance rises rapidly and becomes excessive, and the desired required impact energy absorbability cannot be achieved. May not be able to protect the person's legs. This drag characteristic, that is, the correlation between the deformation drag and the deformation stroke is shown by a broken line ra in the “deformation drag-deformation stroke correlation diagram” shown in FIG.

  As a countermeasure against this, as shown in FIG. 12, in an impact absorbing bumper 110 in which an impact absorbing material 113 formed of a foamed resin such as polypropylene is disposed between a bumper beam 111 and a bumper face 112 extending in the vehicle width direction. A plurality of groove-like recesses 115 and protrusions 116 that are continuous in the vehicle width direction are alternately formed on the rear surface 114 of the shock absorber 113 that is in contact with the front surface 111a of the bumper beam 111 so as to come into contact with an object or a leg of a pedestrian. At the same time, it is known that the projecting portion 116 is compressed or buckled by the impact load P to suppress a sudden rise and increase in initial drag (see, for example, Patent Document 1).

JP 2004-82957 A

  According to Patent Document 1, even when the foaming ratio of the foamed resin is relatively low, the projecting portion 116 of the shock absorbing material 113 is compressed and deformed by the impact load P when it comes into contact with an object or a leg of a pedestrian. By doing so, it is possible to suppress a sudden rise and increase in initial drag.

  However, since the protruding portion 116 is formed in a thin wall shape continuous in the vehicle width direction, in the process of the compressive deformation of the protruding portion 116 due to the impact load P due to contact with an object or a pedestrian, for example, an imaginary line in FIG. As indicated by 116a, there is a concern about the occurrence of buckling deformation such as opening and folding. When buckling deformation occurs in the process of compressive deformation of the protruding portion 116, as shown by a one-dot chain line rb in FIG. 5, when the buckling deformation occurs, the deformation drag is drastically reduced and the desired impact energy absorption is obtained. Therefore, there is a concern that the object and the leg of the pedestrian cannot be sufficiently protected and a situation in which damage is caused is induced.

  Accordingly, an object of the present invention made in view of such a point is to provide a shock absorbing material for a shock absorbing bumper for a vehicle, which can obtain excellent shock energy absorption without causing damage when contacting an object or a pedestrian. There is to do.

  The invention of a shock absorber for a vehicle shock absorbing bumper according to claim 1, which achieves the above object, is disposed extending in the vehicle width direction between a front surface of the bumper beam extending in the vehicle width direction and the bumper face. In the shock absorbing material made of foamed resin, the shock absorbing member extends in the vehicle width direction with a substantially rectangular cross-sectional shape having a front surface, an upper surface, a lower surface, and a rear surface in contact with the front surface of the bumper beam that are covered by the bumper face. A plurality of first central axes that are formed in a block shape and extend in the longitudinal direction of the vehicle body at intervals on an upper reference line that extends in the vehicle width direction along the extending direction of the shock absorber. A bottomed hole-shaped first front hole that extends and opens to the front surface and has a bottom, and a bottomed hole-shaped first hole that opens to the rear surface and has a bottom facing the bottom of the first front hole. 1 rear hole A plurality of second central axes extending in the longitudinal direction of the vehicle body extending in the longitudinal direction of the vehicle body at intervals on the lower reference line extending in the vehicle width direction below the upper reference line and extending in the longitudinal direction of the vehicle body on the front surface. A bottomed cylindrical second front hole having an opening and a bottom, and a bottomed hole-like second rear hole having a bottom opening to the rear surface and facing the bottom of the second front hole. Front and rear compartments that are continuous in the vehicle width direction between the bottoms of the first front holes and the second front holes and the bottoms of the first rear holes and the second rear holes. And the first central axis and the second central axis are alternately arranged offset from each other in the vehicle width direction.

  According to this invention, even if the shock absorbing material is made of a foamed resin having a relatively low expansion ratio, for example, the first front hole, the first rear hole, the second front hole, and the second rear hole The deformation drag is suppressed by the arrangement, the initial deformation drag increases slowly when the vehicle contacts an external object or a pedestrian, and the maximum value of the deformation drag is suppressed.

  In addition, an upper projecting portion continuous in the vehicle width direction between each first front hole and first rear hole and the upper surface, the first front hole and first rear hole, and each second front hole. Upper partition protrusions formed between the first front holes and between the first rear holes adjacent to the intermediate protrusions that are continuous in the vehicle width direction between the holes and the second rear holes The lower protrusion and the intermediate protrusion connected in the vehicle width direction between the second front holes and the second rear holes and the lower surface are between the second front holes and the second rear side. Connected by the lower partition wall protrusion formed between the holes, and the bottom of the first front hole and the second front hole and the bottom of the first rear hole and the second rear hole. A front and rear partition portion extending in the vehicle width direction extending in the vehicle width direction is formed between the first front hole, the first rear hole, the second front hole, and the second rear hole. Formed relatively shallowly In combination with this, buckling deformation of each protrusion is prevented, smooth compression deformation is ensured and good impact energy absorption is obtained, and when contacting with an external object or pedestrian, the object or pedestrian The damage to the can be greatly suppressed.

  Furthermore, by arranging the first front holes and the first rear holes and the second front holes and the second rear holes alternately in the vehicle width direction, A difference in deformation drag is suppressed, and a uniform deformation drag can be secured over the entire width in the vehicle width direction.

  In addition, since the first front side hole, the first rear side hole, the second front side hole, and the second rear side hole are formed relatively shallow, the mold used for molding the shock absorber is used. Die removal is easy and the strength of the mold can be easily secured. Thereby, the stable dimensional accuracy and productivity of the impact-absorbing material made of foamed resin can be ensured.

  The invention of a shock absorber for a vehicle shock absorbing bumper according to claim 2, which achieves the above object, is arranged extending in the vehicle width direction between a front surface of the bumper beam extending in the vehicle width direction and the bumper face. In the shock absorbing material made of foamed resin, the shock absorbing material extends in the vehicle width direction with a substantially rectangular cross-sectional shape having a front surface, an upper surface, a lower surface, and a rear surface in contact with the front surface of the bumper beam covered by the bumper face. A plurality of first central axes that are formed in a block shape and extend in the longitudinal direction of the vehicle body at intervals on an upper reference line that extends in the vehicle width direction along the extending direction of the shock absorber. A bottomed hole-shaped first front hole that extends and opens to the front surface and has a bottom portion, and a lower reference line that extends in the vehicle width direction below the upper reference line and that is spaced in the vehicle longitudinal direction. Extending Each of the second center axis of the first side of the vehicle body extends in the front-rear direction of the vehicle body and opens to the front surface, and has a bottomed hole-shaped second front side hole having a bottom, and the front-rear direction of the vehicle body with a space on the upper reference line A plurality of third central axes extending in a direction extending in the longitudinal direction of the vehicle body as the axis, opening in the rear surface and having a bottomed hole-shaped first rear hole, and on the lower reference line A bottomed hole-like second rear sky that extends in the longitudinal direction of the vehicle body with each fourth central axis extending in the longitudinal direction of the vehicle body arranged at intervals and extending in the longitudinal direction of the vehicle body and having a bottom. And each of the first front holes and the second front holes and the bottoms of the first front holes and the second rear holes are continuous in the vehicle width direction. The first central axis and the second central axis are offset from each other in the vehicle width direction. They are alternately arranged, wherein the third center axis, and a fourth center axis is disposed on the second central axis and the first central axis and the same position in the respective vehicle width direction.

  According to the present invention, the first front holes and the first rear holes arranged on the lower reference line are arranged offset in the vehicle width direction, and are arranged on the lower reference line. The second front holes and the respective second rear holes are arranged offset in the vehicle width direction, and the positions of the first front holes and the second rear holes correspond to each other in the vehicle width direction. Since the positions of the rear holes and the second front holes are arranged corresponding to each other, in addition to the invention of claim 1, it is possible to further suppress variation in deformation resistance of each part in the vehicle width direction. That is, the difference in deformation drag between the respective parts in the vehicle width direction is suppressed, and a uniform deformation drag can be ensured over the entire width in the vehicle width direction, so that reduction of damage to pedestrians and the like can be expected.

  According to a third aspect of the present invention, in the shock absorber for the shock absorbing bumper for a vehicle according to the first or second aspect, the first front hole and the second front hole are cross-sectional shapes orthogonal to the extending direction. The first front side has a widened portion having a relatively wide vertical width at the center and a narrowed portion that is continuous with the widened portion and gradually decreases in width in the vehicle width direction from the widened portion. At least a portion of the narrow portion of the hole and the narrow portion of the second front hole overlap each other in the vehicle width direction, and the first rear hole and the second rear hole extend in the respective directions. In the cross-sectional shape orthogonal to the direction, there is a widened portion having a relatively wide vertical width at the center, and a narrowed portion that is continuous with the widened portion and whose width in the vertical direction gradually narrows away from the widened portion in the vehicle width direction. A narrow portion of the first rear hole and a narrow portion of the second rear hole. Even without wherein the partially duplicated in the vehicle width direction.

  According to the present invention, each first front hole and each second front hole are offset from each other in the vehicle width direction, and at least one of the narrow part of the first front hole and the narrow part of the second front hole. Are overlapped in the vehicle width direction, the first rear holes and the second rear holes are offset from each other in the vehicle width direction, and the narrow portion of the first rear holes and the second rear holes Since at least a part of the narrow width portion of the hole overlaps in the vehicle width direction, a difference in deformation resistance of each portion in the vehicle width direction is suppressed, and a uniform deformation drag can be secured over the entire width in the vehicle width direction.

  According to a fourth aspect of the present invention, in the shock absorber for a shock absorber for a vehicle according to any one of the first to third aspects, a distance in the vehicle width direction between the adjacent first central axis and the second central axis is the same. In the compression test apparatus for compressing and imparting to the shock absorbing material, it is characterized in that it is set smaller than the outer diameter of the cylindrical impactor having the outer diameter assuming the size of a human shin.

  According to the present invention, by setting the distance between the first central axis and the second central axis in the vehicle width direction to be smaller than the outer diameter of the impactor, the difference in deformation drag against the impactor of each part in the vehicle width direction is suppressed. The variation in deformation resistance of each part in the vehicle width direction can be suppressed. That is, since the outer diameter of the impactor is set on the assumption of the size of a human shin, it is possible to secure stable deformation resistance characteristics for the leg portions of each part in the vehicle width direction of the shock absorber, and to ensure that the pedestrian leg portions Damage to the can be suppressed.

  According to the shock absorbing material for the shock absorbing bumper for a vehicle of the present invention, the first front side hole, the first rear side hole, the second front side hole, and the second rear side hole are provided, so that the vehicle is an external object. The increase in deformation resistance when touching a pedestrian or a pedestrian is moderate, the maximum value of the deformation resistance is suppressed, buckling deformation is prevented, smooth compression deformation is ensured, and good impact energy absorption is obtained. Damage to external objects and pedestrians can be suppressed.

  Furthermore, by arranging the first front holes and the first rear holes and the second front holes and the second rear holes alternately in the vehicle width direction, A difference in deformation drag is suppressed, and a uniform deformation drag can be secured over the entire width in the vehicle width direction.

(First embodiment)
A first embodiment of a shock absorbing material for a vehicle shock absorbing bumper according to the present invention will be described below with reference to FIGS. In each figure, an arrow F indicates the vehicle front direction, and an arrow W indicates the vehicle width direction.

  FIG. 1 is a cross-sectional perspective view showing a main part of an outline of a shock absorbing bumper 1 for a vehicle. The shock absorbing bumper 1 is disposed at the front of the vehicle body and extends in the vehicle width direction along the bumper beam 2 that extends in the vehicle width direction, the bumper face 5 that forms the outer surface of the bumper 1, and the front surface 3 of the bumper beam 2. And an impact absorbing material 10 which is covered by the bumper face 5.

  The bumper beam 2 has a substantially hollow rectangular cross-sectional shape and extends in the vehicle width direction. Both ends of the bumper beam 2 are supported by brackets at the front ends of vehicle body frames such as left and right side members extending in the vehicle longitudinal direction (not shown). The bumper beam 2 is formed of a steel plate or the like having excellent rigidity, and the front surface 3 is formed in a substantially rectangular shape that is long in the vehicle width direction. The bumper face 5 is formed of a resin such as polyurethane or polypropylene, and the impact absorbing material 10 is formed of a foamed resin such as polypropylene having a relatively low expansion ratio that is excellent in productivity and ensures product shape accuracy.

  The shock absorber 10 has a substantially rectangular cross-sectional shape having a front surface 11, an upper surface 12, a lower surface 13 and a rear surface 14 in contact with the front surface 3 of the bumper beam 2 covered by the bumper face 5, and extends in the vehicle width direction. The front surface 11, the upper surface 12, the lower surface 13, and the rear surface 14 are formed in a substantially rectangular shape that is long in the vehicle width direction.

  The shock absorber 10 will be described in detail with reference to FIGS. 2 is a partially enlarged view of the front surface 11 of the shock absorber 10, FIG. 3 is a cross-sectional view taken along line II in FIG. 2, and FIG. 4 is a cross-sectional view taken along line II-II in FIG. 3 and 4, the bumper beam 2 is indicated by a virtual line.

  The shock absorber 10 extends on the upper reference line L1 extending in the vehicle width direction along the extending direction thereof and extends in the vehicle front-rear direction with the first central axis 19a extending in the vehicle front-rear direction as an axis. A bottomed hole-shaped first front hole 15 that is open at the rear surface 14 side and closed by the bottom portion 15 a, and a bottom portion 16 a that opens to the rear surface 14 and faces the front surface 11 side to the bottom surface 15 a of the first front hole 15. The closed bottomed first rear air holes 16 are arranged in a plurality of rows at equal intervals in the vehicle width direction.

  Similarly, on the lower reference line L2 extending in the vehicle width direction below the upper reference line L1, the second central axis 19b extending in the vehicle longitudinal direction extends in the vehicle longitudinal direction and opens in the front surface 11. In addition, a bottomed hole-like second front hole 17 whose rear surface 14 side is closed by a bottom portion 17 a and a front surface 11 side which is open to the rear surface 14 and is opposed to a bottom portion 17 a of the second front hole 17 are closed. A plurality of bottom-hole-shaped second rear air holes 18 are provided at equal intervals in the vehicle width direction.

  The first center axis 19a on the upper reference line L1 and the second center axis 19b on the lower reference line L2 are alternately arranged in the vehicle width direction and are alternately arranged. The rear holes 16 and the second front holes 17 and the second rear holes 18 are alternately arranged offset in the vehicle width direction. That is, the first front holes 15 and the first rear holes 16, the second front holes 17 and the second rear holes 18 are alternately arranged over the entire width of the shock absorber 10 in the vehicle width direction. Yes.

  A plurality of first front air holes 15 and first rear air holes 16 are arranged at equal intervals on the upper reference line L1, and a plurality of second front air holes 17 at equal intervals on the lower reference line L2. By arranging the second rear holes 18, the bottom portions 15 a of the first front holes 15 and the bottom portions 17 a of the second front holes 17, the bottom portions 16 a of the first rear holes 16 and the second rear holes 16 are provided. A front / rear partition 20 extending in the vehicle width direction is formed between the side hole 18 and the bottom 18a.

  Further, upper protrusions 21 that are continuous in the vehicle width direction are formed between the first front holes 15 and the first rear holes 16 and the upper surface 12, and the first front holes 15 and the first rear side are formed. Intermediate protrusions 22 that are continuous in the vehicle width direction are formed between the air holes 16 and the second front air holes 17 and the second rear air holes 18, and between the second front air holes 18 and the lower surface 13. The lower protrusion 23 is formed continuously in the vehicle width direction. Further, the upper protrusions 21 and the intermediate protrusions 22 are connected at equal intervals by the upper partition protrusions 24 formed between the adjacent first front holes 15 and between the first rear holes 16, respectively. Similarly, the intermediate protrusions 22 and the lower protrusions 23 are connected at equal intervals by the lower partition wall protrusions 25 formed between the adjacent second front holes 17 and the second rear holes 18. Is done.

  In addition, each first center axis 19a on the upper reference line L1 and each second center axis 19b on the lower reference line L2 are alternately offset from each other in the vehicle width direction so that each adjacent first front side The upper partition wall protrusions 24 formed between the holes 15 and between the first rear holes 16, and between the adjacent second front holes 17 and between the second rear holes 18 are formed. The lower partition wall projections 25 are alternately arranged offset in the vehicle width direction. That is, each of the upper partition wall projections 24 and the lower partition wall projections 25 are arranged offset from each other in the vehicle width direction, and the first front hole 15, the second front hole 17, the first rear hole 16, and the first The two rear holes 18 are formed to overlap each other in the vehicle width direction, that is, overlap each other.

  The shock absorber 10 in which the first front holes 15 and the first rear holes 16 and the second front holes 17 and the second rear holes 18 are alternately arranged in the vehicle width direction is provided. For example, a resin foam particle impregnated with a vapor-type foaming agent using a resin such as a polypropylene resin in advance is manufactured, and the resin foam particle is filled in the mold and heated with steam to fuse the particles. It can be manufactured by an existing molding method such as a foaming method.

  In particular, each dimension a from the front surface 11 to the bottom 15a of the first front hole 15 and the bottom 17a of the second front hole 17, and the bottom 16a and second rear hole of the first rear hole 16 from the rear surface 14. 18 is set to be relatively small, in other words, the depth a of the first front hole 15 and the second front hole 7, the first rear hole 16 and the second rear hole. Since the depth b of 18 is formed to be relatively shallow, it is easy to remove the mold used for molding the shock absorber 10, and the mold strength can be easily secured. Accordingly, stable dimensional accuracy and productivity of the shock absorber 10 made of foamed resin can be ensured.

  As shown in FIG. 1, the shock absorber 10 formed in this way is disposed in the vehicle width direction along the front surface 3 of the bumper beam 2 with the rear surface 14 coming into contact with the front surface 3 of the bumper beam 2. 12 and the lower surface 13 are covered with a bumper face 5 and disposed between the bumper beam 2 and the bumper face 5.

  Next, the operation of the shock absorbing bumper 1 configured as described above will be described.

  When a vehicle equipped with the impact bumper 1 comes into contact with an external object or a leg of a pedestrian, for example, a pedestrian, and an impact load P from the front is applied to the bumper 1, the bumper face 5 passes through the front surface 11. A compressive load is input to the shock absorber 10. When a compression load is input and the shock absorber 10 is compressed in the front-rear direction, the first front hole 15, the first rear hole 16, the second front hole 17, and the second rear hole 18 are formed. The deformation resistance of each of the projecting portions of the upper projecting portion 21, the intermediate projecting portion 22, the lower projecting portion 23, the upper partition wall projecting portion 24, and the lower partition wall projecting portion 25 is set lower than that of the front and rear partition portions 20. Therefore, the upper protruding portion 21, the intermediate protruding portion 22, the lower protruding portion 23, the upper partition wall protruding portion 24, and the lower partition wall protruding portion 25 are mainly compressed and deformed, and deformation resistance is generated along with the compression deformation. To do.

  The deformation drag r and the deformation stroke due to compression deformation of the upper protrusion 21, the intermediate protrusion 22, the lower protrusion 23, the upper partition protrusion 24, the lower partition protrusion 25, and the like are shown by solid lines in FIG. The deformation drag r gradually increases with the deformation stroke, but the deformation drag r is formed by the formation of the first front hole 15, the first rear hole 16, the second front hole 17, and the second rear hole 18. Since r is set low, the increase in the deformation force r in the initial contact is moderate, the maximum value of the deformation force r is suppressed, and an effective deformation stroke is increased, resulting in good impact energy absorption. This ensures the damage to the pedestrian's legs.

  When the upper projecting portion 21, the intermediate projecting portion 22, the lower projecting portion 23, the upper partition projecting portion 24, the lower partition projecting portion 25 and the like are compressed and deformed, the upper projecting portion 21 and the intermediate projecting portion extending in the vehicle width direction. 22 are connected to each other at equal intervals by a plurality of upper partition protrusions 24 extending in the vertical direction, and the intermediate protrusions 22 and the lower protrusions 23 are connected by a plurality of lower partition protrusions 25 extending in the vertical direction. Are connected to each other at intervals, and the front-rear direction intermediate portions of the upper protruding portion 21, the intermediate protruding portion 22, the lower protruding portion 23, the upper partition protruding portion 24, and the lower partition protruding portion 25 are connected to each other by the front and rear partition portions 20, and Combined with the fact that the depth a of the first front hole 15 and the second front hole 17 and the depth b of the first rear hole 16 and the second rear hole 18 are set relatively shallow. Smooth and stable deformation with restrained occurrence of buckling deformation such as mouth opening Force characteristic is good impact energy absorbent can be secured is obtained, damage to the pedestrian can be suppressed.

  Further, the first front holes 15 and the second front holes 17 and the first rear holes 16 and the second rear holes 18 are alternately arranged in the vehicle width direction, so that in the vehicle width direction. Variation in deformation resistance of each part, in other words, the difference in deformation resistance in each part in the vehicle width direction is suppressed, and uniform deformation resistance can be secured over the entire width in the vehicle width direction, and the object when contacting with other objects or pedestrians Can reduce damage to pedestrians and pedestrians.

(Second Embodiment)
Hereinafter, a second embodiment of the shock absorbing material for a vehicle shock absorbing bumper according to the present invention will be described with reference to FIG. In FIG. 6, parts corresponding to those in FIGS. 1 to 4 are given the same reference numerals, and detailed description thereof is omitted, and different parts are mainly described. FIG. 6 is an enlarged front view of the shock absorber 10 corresponding to FIG.

  The shock absorber 10 opens on the front surface 11 with the first central axis 19a extending in the longitudinal direction of the vehicle body as an axis on the upper reference line L1 extending in the vehicle width direction along the extending direction of the shock absorber 10. The bottomed hole-shaped first front holes 15 and the bottomed cylindrical first rear holes 16 opened in the rear surface 14 are arranged in a plurality of rows at equal intervals in the vehicle width direction, and the vehicle body is positioned on the lower reference line L2. A bottomed hole-shaped second front air hole 17 opening in the front surface 11 and a bottomed cylindrical second rear air hole 18 opening in the rear surface 14 having a second central axis 19b extending in the front-rear direction as an axis as a vehicle width. A plurality of rows are arranged at equal intervals in the direction.

  The first front hole 15 extends in the vehicle width direction via the first center line 19a in a cross-sectional shape orthogonal to the first central axis 19a, that is, in a cross-sectional shape orthogonal to the extending direction of the first front hole 15. The upper edge 15c and the lower edge 15d are substantially oval with a linear upper edge 15c and a lower edge 15d, and arc-shaped side edges 15e connecting the ends of the upper edge 15c and the lower edge 15d. A widened portion 15A having a relatively wide vertical width is formed at the center by 15d, and as it moves to the end 15f side that is continuous with the widened portion 15A by each side edge 15e and away from the first central axis 19a, A narrow portion 15B whose width gradually decreases is formed.

  Similarly, the first rear hole 16 has a vehicle width via the first center line 19a in a cross-sectional shape orthogonal to the first central axis 19a, that is, a cross-sectional shape orthogonal to the extending direction of the first front hole 15. A substantially oval shape having linear upper and lower edges 16c and 16d extending in the opposite direction and arcuate side edges 16e connecting the ends of the upper and lower edges 16c and 16d. 16c and the lower edge 16d form a widened portion 16A having a relatively wide vertical width at the center, and each side edge 16e continues to the widened portion 16A and moves to the end 16f side away from the first central axis 19a. Accordingly, a narrow portion 16B is formed in which the vertical width gradually decreases.

  The second front air hole 17 extends in the vehicle width direction via the second central axis 19b in a cross-sectional shape orthogonal to the second central axis 19b, that is, a cross-sectional shape orthogonal to the extending direction of the second front air hole 17. The upper edge 17c and the lower edge 17d, which are opposed to each other, are substantially oval having arcuate side edges 17e that connect the ends of the upper edge 17c and the lower edge 17d. A widened portion 17A having a relatively wide vertical width is formed in the central portion by the edge 17d, and the vertical direction as the side edge 17e continues to the widened portion 17A and moves toward the end portion 17f away from the second central axis 19b. A narrow portion 17B is formed in which the width of each of the portions gradually decreases.

  The first center axis lines 19a on the upper reference line L1 and the second center axis lines 19b on the lower reference line L2 are alternately arranged offset in the vehicle width direction, and each first front hole 15 and each second The front holes 17 are offset from each other in the vehicle width direction, and at least a part of the narrow width portion 15B of the first front hole 15 and the narrow width portion 17B of the second front hole 17 are overlapped in the vehicle width direction, that is, overlapped. Arrange. Similarly, the first rear air holes 16 arranged on the upper reference line L1 and the second rear air holes 18 arranged on the lower reference line L2 are offset from each other in the vehicle width direction. At the same time, at least a part of the narrow portion 16B of the first rear hole 16 and the narrow portion 18B of the second rear hole 18 are overlapped in the vehicle width direction, that is, overlapped in the vehicle width direction.

The narrow portion 15 B of the first front hole 15, the narrow portion 17 B of the second front hole 17, the narrow portion 16 B of the first rear hole 16, and the narrow portion 18 B of the second rear hole 18. The upper projection 21, the middle projection 22, the lower projection 23, the upper partition projection 24, the lower partition projection 25, and the like in each longitudinal section in the vehicle width direction Variation in the overall area of the part is suppressed. For example, the occupation area of the protrusions such as the upper protrusion 21, the intermediate protrusion 22, the lower protrusion 23, the upper partition protrusion 24, and the lower partition protrusion 25 in the III-III line section, and the upper side in the IV-IV line section. The difference in the occupied area of the projecting parts such as the projecting part 21, the intermediate projecting part 22, the lower projecting part 23, the upper partition projecting part 24 and the lower partition projecting part 25 is suppressed, and the deformation resistance of each part in the vehicle width direction is reduced. Variations can be suppressed. In other words, in addition to the first embodiment, the difference in deformation drag of each part in the vehicle width direction is suppressed, and a uniform deformation drag can be secured over the entire width in the vehicle width direction, thereby reducing damage to the pedestrian's legs. Can be expected.

  The cross-sectional shapes of the first front hole 15, the first rear hole 16, the second front hole 17, and the second front hole 18 are not limited to the shape shown in FIG. Other cross-sectional shapes having a wide portion having a relatively wide vertical width, and having a narrow width portion that is continuous with the wide width portion and gradually narrows in the vertical direction as the distance from the wide width portion in the vehicle width direction, for example, circular, It can be changed to an ellipse, rhombus, etc.

(Third embodiment)
Hereinafter, a third embodiment of the shock absorbing material for a vehicle shock absorbing bumper according to the present invention will be described with reference to FIGS. 7 and 8, the same reference numerals are given to the portions corresponding to those in FIGS. 1 to 4, and the detailed description thereof will be omitted.

  FIG. 7 is a partially enlarged view of the front surface 11 of the shock absorber 10 corresponding to FIG. 2, and the shock absorber 10 has an upper reference line L1 extending in the vehicle width direction along its extending direction. A bottomed hole-shaped first front hole 15 extending in the vehicle front-rear direction and opening in the front surface 11 with a first central axis 19a extending in the vehicle body longitudinal direction as an axis and a bottomed hole-shaped first hole opening in the rear surface 14 are provided. The rear holes 16 are arranged in a plurality of rows at equal intervals in the vehicle width direction, and extend in the vehicle front-rear direction with the second central axis 19b extending in the vehicle front-rear direction on the lower reference line L2 as the axis. A plurality of bottomed hole-like second front holes 17 opening in the rear and a bottomed hole-like second rear hole 18 opening in the rear surface 14 are arranged in a plurality of rows at equal intervals in the vehicle width direction. The first central axis 19a arranged on the upper reference line L1 and the second central axis 19b arranged on the lower reference line L2 are alternately arranged offset in the vehicle width direction. The holes 15 and the first rear holes 16 and the second front holes 17 and the second rear holes 18 are alternately arranged offset in the vehicle width direction.

  A compression test for inspecting the deformation resistance characteristic of the shock absorber 10 will be described with reference to FIG. 8A is a side view of the test apparatus 50, and FIG. 8B is a plan view.

  The compression test method is performed by compressing the impact absorbing material 10 at a preset test speed using an impactor made of a rigid pipe as a compression jig under conditions of preset temperature and relative humidity. The outer diameter D of the impactor 51 assumes the size of a human shin.

  In FIG. 8, 10 is an impact absorbing material to be a test piece, 51 is an impactor made of a rigid pipe having an outer diameter D of 70 mm, 52 is a holding base for a test piece made of a rigid body extending in the horizontal direction, 53 Is a compression device to which the impactor 51 is attached.

  The support base 52 is installed extending in the horizontal direction assuming the height of the bumper beam 2 of the bumper 1 mounted on the vehicle. The shock absorbing material 10 serving as a test piece is installed with the rear surface 14 facing the front surface 52a of the support base 52 and extending in the horizontal direction. As shown in FIGS. 8A and 8B, the compression device 53 assumes that the bumper 1 mounted on the vehicle contacts a pedestrian, that is, a standing person, from the front surface 11 side of the shock absorber 10. Further, the impactor 51 is compressed in the front-rear direction from the front surface 11 side of the shock absorber 10 so that the axial direction of the impactor 51 is perpendicular to the length direction (vehicle width direction) of the shock absorber 10 (ie, the vehicle width direction). Perform a compression test.

  Each shock absorber 10 is subjected to a compression test until a compression strain set in advance, for example, 70% or more, that is, a deformation stroke is generated, and a compression load at each deformation stroke, that is, a deformation drag is measured from a compression curve. To do.

  Here, the first central axis 19a serving as the axis of each first front hole 15 and the first rear hole 16 in the vehicle width direction, and the axis of the second front hole 17 and the second rear hole 18, respectively. By setting the interval L4 of the second central axis 19b to be smaller than the outer diameter D of the impactor 51 (L4 <D), the upper projecting portion 21 by the impactor 51 in each portion in the longitudinal direction of the impact absorbing member 10 and the middle Variations in the projected area of the protrusion 22, the lower protrusion 23, the upper partition protrusion 24, and the lower partition protrusion 25 are suppressed. That is, the difference in deformation resistance of each part with respect to the impactor 51 in the vehicle width direction is suppressed, and variation in deformation resistance of each part in the vehicle width direction can be suppressed. In other words, since the diameter D of the impactor 51 is set on the assumption of the size of a human shin, stable deformation resistance characteristics can be secured and damage to the pedestrian can be suppressed.

  In the present embodiment also, as in the second embodiment, the cross-sectional shapes of the first front hole 15, the first rear hole 16, the second front hole 17, and the second rear hole 18 are the same. Has a widened portion having a relatively wide width in the vertical direction of the central portion, a shape having a narrowed portion that is continuous with the widened portion and has a gradually narrowing width in the vertical direction as it is separated from the widened portion in the vehicle width direction. As a result, the deformation resistance difference in the vehicle width direction is suppressed, a uniform deformation resistance can be secured over the entire width in the vehicle width direction, and reduction of damage to the pedestrian's legs can be expected.

(Fourth embodiment)
Hereinafter, a fourth embodiment of the shock absorbing material for a vehicle shock absorbing bumper according to the present invention will be described with reference to FIGS. 9 and 10, the same reference numerals are given to the portions corresponding to those in FIGS. 1 to 4, and the detailed description thereof will be omitted.

  9 is a partially enlarged view of the front surface 11 of the shock absorber 10 corresponding to FIG. 2, FIG. 10 (a) is a cross-sectional view taken along line VV of FIG. 9, and FIG. FIG.

  The shock absorber 10 extends on the upper reference line L1 extending in the vehicle width direction along the extending direction thereof and extends in the vehicle front-rear direction with the first central axis 19a extending in the vehicle front-rear direction as an axis. A plurality of first front-side air holes 15 having a bottomed hole shape whose rear surface 14 side is closed by a bottom portion 15a are provided at equal intervals in the vehicle width direction.

  Similarly, on the lower reference line L2 extending in the vehicle width direction below the upper reference line L1, the second central axis 19b extending in the vehicle longitudinal direction extends in the vehicle longitudinal direction and opens in the front surface 11. Also, a plurality of rows of bottomed hole-like second front holes 17 whose rear surface 14 side is closed by the bottom portion 17a are provided at equal intervals.

  Furthermore, it extends in the front-rear direction with the third center axis 19c extending in the front-rear direction as a center at a position on the upper reference line L1 and in the same position as the second center axis 19b in the vehicle width direction, and opens in the rear surface 14. In addition, a plurality of bottomed hole-shaped first rear holes 16 whose front surface 11 side is closed by a bottom portion 16a are arranged at equal intervals in the vehicle width direction. Similarly, on the lower reference line L2 and at the same position as the first central axis 19a in the vehicle width direction, the fourth central axis 19d extending in the front-rear direction extends in the front-rear direction and extends to the rear surface 14. A plurality of rows of bottomed hole-like second rear holes 18 that are open and closed on the front surface 11 side by a bottom portion 18a are arranged at equal intervals in the vehicle width direction.

  In other words, the first central axis lines 19a and the second central axis lines 19b are alternately arranged with an offset in the vehicle width direction, and the third central axis line 19c and the fourth central axis line 19d are respectively a second center in the vehicle width direction. The first front air holes 15 and the first rear air holes 16 arranged on the upper reference line L1 are offset in the vehicle width direction and are arranged at the same positions as the axis 19b and the first central axis 19a. The second front air holes 17 and the second rear air holes 18 arranged on the lower reference line L2 are arranged offset in the vehicle width direction, and the first front air holes are arranged in the vehicle width direction. 15 corresponds to the positions of the second rear holes 18, and the positions of the first rear holes 16 and the second front holes 17 correspond to each other.

  Thereby, between the bottom 15a of each first front hole 15 and the bottom 17a of the second front hole 17, and the bottom 16a of the first rear hole 16 and the bottom 18a of the second rear hole 18 are provided. A front and rear partition 20 extending in the vehicle width direction is formed. Further, upper protrusions 21 that are continuous in the vehicle width direction are formed between the first front holes 15 and the first rear holes 16 and the upper surface 12, and the first front holes 15 and the first rear side are formed. Intermediate protrusions 22 that are continuous in the vehicle width direction are formed between the air holes 16 and the second front air holes 17 and the second rear air holes 18, and between the second front air holes 18 and the lower surface 13. The lower protrusion 23 is formed continuously in the vehicle width direction.

  Further, the upper protrusions 21 and the intermediate protrusions 22 are connected at equal intervals by the upper partition protrusions 24 formed between the adjacent first front holes 15 and between the first rear holes 16, respectively. Similarly, the intermediate protrusions 22 and the lower protrusions 23 are connected at equal intervals by the lower partition wall protrusions 25 formed between the adjacent second front holes 17 and the second rear holes 18. .

  The first front holes 15 and the first rear holes 16 arranged on the upper reference line L1 and the second front holes 17 and the second rear side arranged on the lower reference line L2. The upper partition wall protrusions 24 formed between the adjacent first front holes 15 and the first rear holes 16 by alternately disposing the holes 18 in the vehicle width direction are alternately arranged. And the lower partition protrusions 25 formed between the adjacent second front holes 17 and between the second rear holes 18 are alternately arranged in the vehicle width direction. That is, each of the upper partition wall projections 24 and the lower partition wall projections 25 are arranged offset from each other in the vehicle width direction, and the first front hole 15, the second front hole 17, the first rear hole 16, and the first The two rear holes 18 are formed to overlap each other in the vehicle width direction, that is, overlap each other.

  Furthermore, the front upper partition wall protrusion 24a formed between the adjacent first front holes 15 and the first rear hole 16 offset in the vehicle width direction with respect to the front upper partition protrusion 24a. An upper partition wall projection 24 connecting the upper projection 21 and the intermediate projection 22 is formed by the rear upper partition projection 24a formed between the upper projection 21a and the rear projection 24a. On the other hand, the front side lower partition wall protruding portion 25a formed between the adjacent second front side holes 17 and the front side lower partition wall protruding portion 25a are offset in the vehicle width direction and are offset in the second rear side space. A lower partition protrusion 25 that connects the intermediate protrusion 22 and the lower protrusion 23 is formed by a rear lower partition protrusion 25 a formed between the holes 18.

  Further, the first front axis line 19a arranged on the upper reference line L1 and the second central axis line 19b arranged on the lower reference line L2 are arranged offset from each other in the vehicle width direction, so that the first front side The air holes 15 and the second front air holes 17 are overlapped with each other in the vehicle width direction, that is, overlapped with each other, and are arranged on the third central axis 19c and the lower reference line L2 arranged on the upper reference line L1. By disposing the fourth central axis lines 19d provided so as to be offset from each other in the vehicle width direction, the first rear hole 16 and the second rear hole 18 overlap each other in the vehicle width direction, that is, overlap each other. Formed.

  In this way, the first front holes 15 and the first rear holes 16 arranged on the lower reference line L2 are offset in the vehicle width direction and arranged on the lower reference line L2. The second front air holes 17 and the second rear air holes 18 that are arranged are arranged offset in the vehicle width direction, and the first front air holes 15 and the second rear air holes are arranged in the vehicle width direction. 18 is arranged at the same position, and the first rear air hole 16 and the second front air hole 17 are arranged at the same position, so that the upper side in each longitudinal section in the vehicle width direction as compared with the first embodiment. The upper partition protrusion 24, the front lower partition protrusion 25a, and the rear side, including the protrusion 21, the intermediate protrusion 22, the lower protrusion 23, the front upper partition protrusion 24a, and the rear upper partition protrusion 24b. The variation in the total area of the lower partition wall projection 25 composed of the lower partition wall projection 25b is further suppressed, and the vehicle Variations in the deformation resistance force of each part in the direction can be suppressed.

  That is, in addition to the first embodiment, the difference in deformation drag in the vehicle width direction is suppressed, and a uniform deformation drag can be ensured over the entire width in the vehicle width direction. Reduction can be expected.

  In the present embodiment, as in the second embodiment, the cross-sectional shapes of the first front hole 15, the first rear hole 16, the second front hole 17, and the second rear hole 18 are the same. The center portion has a widened portion having a relatively wide width in the vertical direction, and has a narrow width portion that is continuous with the widened portion and gradually decreases in width in the vertical direction away from the widened portion in the vehicle width direction. Thus, the deformation resistance difference of each part in the vehicle width direction is further suppressed, and a uniform deformation resistance can be ensured over the entire width in the vehicle width direction, and reduction of damage to the pedestrian's legs can be expected.

  Further, as in the third embodiment, the distance L4 between each first center axis 19a and each second center axis 19b in the vehicle width direction can be set smaller than the outer diameter D of the impactor 51 of the test apparatus 50. . As a result, the difference in deformation drag of each part in the vehicle width direction with respect to the impactor 51 is suppressed, and variation in the deformation drag of each part in the vehicle width direction can be suppressed, and the diameter D of the impactor 51 assumes the size of a human shin. Therefore, stable deformation resistance characteristics can be secured and damage to the pedestrian's legs can be suppressed.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in each of the above-described embodiments, the upper reference line L1 and the lower side extending in the vehicle width direction through the first front hole 15, the first rear hole 16, the second front hole 17, and the second rear hole 18. Although an example in which the reference lines L2 are arranged in two rows has been described, for example, holes can be arranged in other rows such as three rows or four rows.

It is a principal part section perspective view showing an outline of a shock absorption bumper for vehicles concerning a 1st embodiment of the present invention. It is a partially enlarged view of the front surface of the shock absorber. It is the II sectional view taken on the line of FIG. It is the II-II sectional view taken on the line of FIG. It is a deformation drag-deformation stroke correlation diagram. It is a partial enlarged view of the front surface of the shock absorbing material showing an outline of the shock absorbing bumper for vehicles according to the second embodiment of the present invention. It is a partial enlarged view of the front surface of the shock absorbing material of the shock absorbing bumper for vehicles according to the third embodiment of the present invention. It is explanatory drawing which shows the outline | summary of the compression test method of an impact-absorbing material, (a) is a side view of a compression test apparatus, (b) is a top view. It is a partial enlarged view of the front surface of the shock absorbing material showing the outline of the shock absorbing bumper for vehicles according to the fourth embodiment of the present invention. (A) is the VV sectional view taken on the line of FIG. 9, (b) is the VI-VI sectional view taken on the line of FIG. It is sectional drawing of the conventional impact-absorbing bumper. It is sectional drawing of the conventional impact-absorbing bumper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle shock absorption bumper 2 Bumper beam 5 Bumper face 10 Shock absorber 11 Front surface 12 Upper surface 13 Lower surface 14 Rear surface 15 1st front side hole 15A Wide part 15B Narrow part 16 1st back side hole 16A Wide part 16B Narrow part 17 2nd front side hole 17A Wide part 17B Narrow part 18 2nd back side hole 18A Wide part 18B Narrow part 19a-19d 1st-4th center axis line 20 Front and rear partition part 21 Upper protrusion part 22 Intermediate protrusion part 23 Lower protrusion 24 Upper partition protrusion 25 Lower partition protrusion 50 Test device 51 Impactor D Impactor outer diameter L1 Upper reference line L2 Lower reference line L4 The first central axis and the second central axis in the vehicle width direction interval

Claims (4)

In the shock absorber made of a foamed resin that extends in the vehicle width direction between the front surface of the bumper beam extending in the vehicle width direction and the bumper face,
The shock absorbing member is formed in a block shape extending in the vehicle width direction with a substantially rectangular cross-sectional shape having a front surface, an upper surface, a lower surface and a rear surface in contact with the front surface of the bumper beam, which are covered by the bumper face.
The front surface extends in the vehicle longitudinal direction with a plurality of first central axes extending in the vehicle longitudinal direction at intervals on an upper reference line extending in the vehicle width direction along the extending direction of the shock absorber. A bottomed hole-shaped first front hole having a bottom and a bottom, and a bottomed hole-shaped first rear hole having a bottom that opens to the rear surface and faces the bottom of the first front hole; ,
A plurality of second central axes extending in the longitudinal direction of the vehicle body and extending in the longitudinal direction of the vehicle body at intervals on the lower reference line extending in the vehicle width direction below the upper reference line and extending in the longitudinal direction of the vehicle body and opening in the front surface And a bottomed cylindrical second front hole having a bottom and a bottomed hole-like second rear hole having a bottom that opens to the rear surface and faces the bottom of the second front hole. And
A front and rear partition section that is continuous in the vehicle width direction is provided between each bottom portion of each of the first front holes and second front holes and each bottom portion of each of the first rear holes and second rear holes. A shock absorbing material for a vehicle shock absorbing bumper, wherein the first central axis and the second central axis are alternately arranged offset in the vehicle width direction. In the shock absorber made of a foamed resin that extends in the vehicle width direction between the front surface of the bumper beam extending in the vehicle width direction and the bumper face,
The shock absorber is formed in a block shape extending in the vehicle width direction in a substantially rectangular cross-sectional shape having a front surface, an upper surface, a lower surface and a rear surface in contact with the front surface of the bumper beam, which are covered by the bumper face.
The front surface extends in the vehicle longitudinal direction with a plurality of first central axes extending in the vehicle longitudinal direction at intervals on an upper reference line extending in the vehicle width direction along the extending direction of the shock absorber. A bottomed hole-shaped first front hole having a bottom and an opening,
A plurality of second central axes extending in the longitudinal direction of the vehicle body at intervals on a lower reference line extending in the vehicle width direction below the upper reference line extend in the longitudinal direction of the vehicle body and open to the front surface. And a bottomed hole-like second front hole having a bottom portion,
A bottomed hole-shaped first rear that extends in the longitudinal direction of the vehicle body with a plurality of third central axes extending in the longitudinal direction of the vehicle body at intervals on the upper reference line and that opens in the rear surface and has a bottom portion. Side vacancies,
A bottomed hole-like shape having a plurality of fourth central axes extending in the longitudinal direction of the vehicle body that are arranged at intervals on the lower reference line and extending in the longitudinal direction of the vehicle body and opening in the rear surface and having a bottom portion A second rear side hole,
A front and rear partition section that is continuous in the vehicle width direction is provided between each bottom portion of each of the first front holes and second front holes and each bottom portion of each of the first rear holes and second rear holes. In addition, the first central axis and the second central axis are alternately arranged offset in the vehicle width direction, and the third central axis and the fourth central axis are respectively arranged in the vehicle width direction. A shock absorbing material for a shock absorbing bumper for a vehicle, wherein the shock absorbing material is disposed at the same position as the first central axis. The first front side hole and the second front side hole are connected to the widened part having a relatively wide vertical width at the center part in the cross-sectional shape orthogonal to the extending direction and the widened part, and from the widened part to the vehicle. A narrow width portion whose width in the up-down direction gradually narrows with increasing distance from the width direction, and at least a part of the narrow width portion of the first front side hole and the narrow width portion of the second front side hole are mutually in the vehicle width direction Duplicated in
The first rear side hole and the second rear side hole have a widened portion having a relatively wide vertical width at the center and a widened portion at the center in a cross-sectional shape orthogonal to the extending direction. A narrow width portion whose width in the up-down direction gradually decreases as the distance from the vehicle width direction increases, and at least part of the narrow width portion of the first rear hole and the narrow width portion of the second rear hole is The shock absorbing material for a vehicle shock absorbing bumper according to claim 1 or 2, wherein the shock absorbing material overlaps with each other in the vehicle width direction. The distance between the adjacent first central axis and the second central axis in the vehicle width direction of the cylindrical impactor having an outer diameter assuming the size of a human shin in a compression test apparatus that compresses and applies to the shock absorber. The shock absorbing material for a vehicle shock absorbing bumper according to any one of claims 1 to 3, wherein the shock absorbing material is set smaller than an outer diameter.

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