JP2008024141A - Impact absorbing body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing body capable of retaining a plurality of granulated bodies to desired shapes. <P>SOLUTION: The impact absorbing body 20 absorbs an impact by the plurality of granulated bodies 26... when the impact is applied. The impact absorbing body 20 has a plurality of sheets of granulated body bonding plates 22... formed into plate-like shapes by bonding the plurality of granulated bodies 26... to one another and is made to be the impact absorbing body 20 by superposing the plurality of sheets of the granulated body bonding plates 22... on the respective superposed surfaces 22b..., 22c... in a laminar shape. The granulated bodies 26... are formed to a cube, arranged so that upper surfaces 26a... of the respective granulated bodies 26... become flush with one another and arranged so that lower surfaces 26... of the respective granulated bodies 26... become flush with one another. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an impact absorber, and more particularly to an impact absorber that absorbs an impact with a plurality of particles when the impact is applied.

Automobiles have front and rear bumper beams at the front and rear of the car body so that when the front bumper beam and rear bumper beam are impacted, the front and rear bumper beams are deformed to absorb the impact. It is configured.
The occupant is protected by absorbing the impact with the front and rear bumper beams.

Here, some of the front and rear bumper beams are equipped with an impact buffering member that reduces the impact acting on the low-rigidity object when the automobile collides with a low-rigidity obstacle (object). (For example, refer to Patent Document 1).
JP, 2004-114864, A Since the front and rear bumper beams have similar structures, the front bumper beam will be described as a bumper beam, and the description of the rear bumper beam will be omitted.

The impact buffering member of Patent Document 1 is provided along the longitudinal direction on the front surface of the bumper beam, and the cross-sectional shape is determined so as to be deformed by a relatively small impact.
By determining the cross-sectional shape so as to be deformed with a relatively small impact, when the automobile collides with a low-rigidity object, the shock-absorbing member is deformed to reduce the impact acting on the low-rigidity object.
However, it is relatively difficult to determine the cross-sectional shape of the shock-absorbing member so as to alleviate the impact acting on the low-rigidity object, and the examination time is long.

By the way, it is preferable to apply this shock absorbing member not only to the impact reduction for the low-rigidity object but also to the impact reduction for the occupant.
However, it is more difficult to determine the cross-sectional shape of the shock absorbing member so that the shock absorbing member can be applied to both the impact reduction for the low-rigidity object and the impact reduction for the occupant.

Here, in the impact buffering member, a plurality of solids (particles) are restrained by a restraining tool, and when the impact is applied, the plurality of particles are relatively moved, and the impact is applied by the frictional resistance (friction energy) at that time. What absorbs is known (for example, refer to Patent Document 2).
JP 2000-274471 A

Since the impact buffering member of Patent Document 2 absorbs the impact by the frictional resistance caused by the relative movement of a plurality of particles, the impact can be absorbed more suitably than the impact buffering member of Patent Document 1.
If the shock-absorbing member of Patent Document 2 is provided on the front surface of the bumper beam, it can be realized relatively easily to serve both as an impact relief for a low-rigidity object and an impact relief for an occupant.

By the way, the shock absorbing member of Patent Document 2 uses a flexible film such as a polymer film as a restraint to move the plurality of particles in order to absorb the impact by the frictional resistance caused by the relative movement of the plurality of particles. It is easy to do.
However, when a flexible film is used as a restraining tool, the flexible film is deformed, and it is difficult to hold (bundling) a plurality of particles in a desired shape with the flexible film.

For example, when the shock absorbing member is provided on the front surface of the bumper beam, it is preferable to form the shock absorbing member with a rectangular cross section. However, the shock absorbing member of Patent Document 2 holds a plurality of particles in a rectangular cross section. It is not possible.
Therefore, there has been a demand for practical use of an impact buffering member capable of holding a plurality of particles in a desired shape.

  An object of the present invention is to provide an impact absorber capable of holding a plurality of particles in a desired shape.

  The invention according to claim 1 is a shock absorber that absorbs an impact with a plurality of granules when an impact is applied, and the plurality of grains formed in a plate shape by joining the plurality of granules together. It has a body bonding plate, and a plurality of granule bonding plates are layered on each overlapping surface to form a shock absorber.

  According to a second aspect of the present invention, the particles are formed in a cube, and one surface of each particle is disposed so as to be flush with each other. A feature is that a mating surface is formed.

  The invention according to claim 3 is characterized in that the plurality of granular material bonding plates are joined at the overlapping surfaces.

  The invention according to claim 4 is provided with a shape holding member for holding the end faces of each of the particle-binding plates in order to prevent the plurality of particle-binding plates from moving along the overlapping surfaces. It is characterized by that.

In the invention according to claim 1, a plurality of particles are bonded to each other to form a plate-shaped particle bonding plate. The shape of the particle | grain coupling | bonding board can be maintained by couple | bonding several particle | grains mutually.
Then, a plurality of granule bonding plates were layered to form an impact absorber. By laminating a plurality of particle-bound plates in a layered manner, the respective particle-bound plates can be kept in a stable state.
In this way, the shape of the particle bonding plate can be maintained, and a plurality of particle bonding plates can be maintained in a layered state, so that an impact absorber formed of a plurality of particles can be obtained. It can be held in a desired shape.

By coupling a plurality of particles together, for example, when the shock absorber collides with a relatively low-rigid rod-shaped object, it is possible to suppress the particles from diffusing (escape) at the initial stage of the collision. Note that the rod-shaped object is, for example, a cylindrical object.
By restraining the diffusion (escape) of the particles at the initial stage of the collision, it is possible to advance the restraint start time of the rod-like object by the shock absorber.

By suppressing the diffusion (escape) of the particles, the particles hitting the rod-like object are pressed by the rod-like object in the width direction and the thickness direction of the shock absorber.
Therefore, the particles hitting the rod-shaped object are released from the connection with the adjacent particles, and slide and move with the pressing force acting on the adjacent particles.

As a result, frictional resistance (friction energy) is generated when the particles hitting the rod-shaped object slide, and the impact force can be absorbed by the generated friction energy.
In addition, kinetic energy is generated by the movement of the particles, and the impact force can be absorbed by the generated kinetic energy.
In this way, by absorbing the impact force with the frictional energy or the kinetic energy, the impact force can be absorbed well and the impact force acting on the rod-like object can be suppressed.

In the invention which concerns on Claim 2, each surface can be formed in a flat surface by forming a granule in a cube. Therefore, a large contact area between adjacent particles can be ensured.
As a result, it is possible to satisfactorily slide the particles that have hit the rod-like object, efficiently generating frictional energy and absorbing the impact force well.

Moreover, the trouble of processing the overlapping surface flat can be saved by forming the overlapping surface of the particle bonding plate on one surface of each particle.
Thus, the productivity of the shock absorber can be increased by eliminating the trouble of processing the overlapping surfaces flatly.

In the invention which concerns on Claim 3, a plurality of granule coupling plates can be integrated by joining a plurality of granule coupling plates at the overlapping surfaces. Therefore, a holding member for integrating a plurality of granular material bonding plates can be eliminated, and the number of parts can be reduced.
Furthermore, by integrating a plurality of granular material bonding plates by bonding, an impact absorber can be easily manufactured, and productivity can be increased.

In the invention which concerns on Claim 4, by holding | maintaining the end surface of a plurality of granule coupling board with a shape holding member, it prevents that each granule coupling board moves along a mutual overlapping surface.
Therefore, when the shock absorber collides with a relatively low-rigid rod-shaped object, it is possible to satisfactorily prevent the particles from diffusing (escape) in the width direction of the shock absorber.
As a result, the granules hitting the rod-shaped object slide and move in a state where the pressing force is suitably applied to the adjacent granules.
Accordingly, the friction energy is suitably generated, and the impact force can be favorably absorbed by the generated friction energy.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. Note that “front”, “rear”, “left”, and “right” indicate Fr as the front, Rr as the rear, L as the left, and R as the right according to the direction viewed from the operator.

FIG. 1 is a perspective view showing a front bumper beam provided with an impact absorber (first embodiment) according to the present invention.
The vehicle body 10 includes a left front side frame 12 at a left front portion, a right front side frame 13 at a right front portion thereof, and front bumpers at a front end portion 12a of the left front side frame 12 and a front end portion 13a of the right front side frame 13. The beam 15 is bridged, and a shock absorber 20 is provided on the central front surface 16a of the front bumper beam 15.

The shock absorber 20 is attached to the central front surface 16 a of the front bumper beam 15 in a state of being housed in the bag body 21. The bag body 21 is made of, for example, a sheet or woven fabric made of polypropylene (PP) and having a film thickness of 1000 μm.
In order to facilitate understanding of the shock absorber 20, the bag body 21 will be omitted below.

The front bumper beam 15 includes a central portion 16 that extends in the vehicle body width direction, a left bent portion 17 that extends backward from the left end portion of the central portion 16 toward the outside, and an outward direction from the right end portion of the central portion 16. And a right bent part 18 extending in a state inclined rearward.
The front bumper beam 15 has a left bent portion 17 attached to the front end portion 12 a, a right bent portion 18 attached to the front end portion 13 a, and a shock absorber 20 provided on the central front surface 16 a of the central portion 16.

2 is a cross-sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a perspective view showing the shock absorber according to the first embodiment alone.
As an example, the shock absorber 20 has a back surface 20a bonded to the central front surface 16a of the front bumper beam 15 with an adhesive.
The shock absorber 20 includes a shape holding member 24 that superimposes the five granular bonding plates 22 in a layered manner and holds the peripheral surfaces (end surfaces) 22a of the superimposed granular bonding plates 22. .

  The granule coupling plate 22 is formed in a rectangular plate shape by coupling a plurality of granules 26 to each other. The granule bonding plate 22 has an upper overlapping surface (overlapping surface) 22b as an upper surface and a lower overlapping surface (overlapping surface) 22c as a lower surface.

By superposing the upper particle bonding plate 22 in a layered manner on the lower particle bonding plate 22, the lower overlapping surface 22 c of the upper particle bonding plate 22 is overlapped with the upper overlapping surface 22 b of the lower particle bonding plate 22. Are superimposed.
In addition, the back surface 20a of the impact absorber 20 mentioned above is the lower overlapping surface 22c of the particle | grain coupling | bonding board 22 arrange | positioned at the lowest step.

The granule 26 is formed in a cube with flat surfaces of an upper surface (one surface) 26a, a lower surface (one surface) 26b, and first to fourth side surfaces 26c. As the granules 26, for example, a cube made of foamed polypropylene (PP) and having a shape of 10 × 10 × 10 mm is used.
The first to fourth side surfaces 26c are provided with coupling sites 27 along the peripheral edge 26d of the lower surface 26b. The binding sites 27 are sites that are bonded to the four grains 26 adjacent to the first to fourth side surfaces 26c.
As a result, the plurality of granules 26 are joined to each other at the joining sites 27 to form a plate-like grain joining plate 22.

In other words, the granule bonding plate 22 has slits 28 formed in a lattice shape from the upper overlapping surface 22b side to the lower overlapping surface 22c, and has the bonding sites 27 on the lower overlapping surface 22c side. It is.
Here, assuming that the height of the particles 26 is H1, and the height of the binding site 27 is H2, the depth of the slit 28 is (H1-H2).

The granule coupling plate 22 is arranged so that the upper surfaces 26a of the granules 26 are flush with each other, and the upper overlapping surface 22b is formed by the upper surfaces 26a of the granules 26.
Furthermore, the particle | grain coupling | bonding board 22 is arrange | positioned so that the lower surface 26b ... of the particle | grains 26 ... may each be flush | level, and the lower overlapping surface 22c is formed in the lower surface 26b ...

In this way, by forming the upper overlapping surface 22b of the particle coupling plate 22 on the upper surfaces 26a of the particles 26, the trouble of processing the upper overlapping surface 22b to be flat can be saved. Further, by forming the lower overlapping surface 22c of the particle coupling plate 22 on the lower surfaces 26b of the particles 26, it is possible to save the trouble of processing the lower overlapping surface 22c flatly.
The productivity of the shock absorber 20 can be improved by eliminating the trouble of processing the upper and lower overlapping surfaces 22b and 22c flatly.
This granule-binding plate 22 is formed so that the dimensions of length × width × thickness are 600 × 100 × 10 mm, for example, by arranging the granules 26.

The shape-retaining member 24 is arranged so as to prevent the plurality of granule bonding plates 22... From moving along the overlapping surfaces 22 b. It is wound around the surface (end surface) 22a.
Thereby, the shape retaining member 24 holds the circumferential surfaces 22a of the overlapped particle body coupling plates 22.
As the shape holding member 24, for example, a film made of low foam polypropylene (PP) and having a film thickness of 100 μm is used.

In the shock absorber 20, the shape of the particles 26 is 10 × 10 × 10 mm, the shape of the particle bonding plate 22 is 600 × 100 × 10 mm, and five particle bonding plates 22 are overlapped.
Therefore, the shock absorber 20 has a length × width × thickness of 600 × 100 × 50 mm, for example.

As described above, according to the shock absorber 20, the plurality of particles 26 are bonded to each other to form the plate-shaped particle bonding plate 22. The shape of the particle | grain coupling | bonding board 22 is maintainable by couple | bonding several particle | grains 26 ... mutually.
Then, a plurality of the granular material bonding plates 22... By laminating a plurality of the particle bonding plates 22 in a layered manner, the respective particle bonding plates 22 can be kept in a stable state.
In this way, the shape of the particle-binding plates 22 can be maintained, and the plurality of particle-binding plates 22 can be maintained in a layered state. The formed shock absorber 20 can be held in a desired shape.

Next, a method for manufacturing the shock absorber will be described with reference to FIGS.
FIGS. 4A and 4B are views for explaining an example of forming the grain-boundary plate according to the first embodiment.
In (a), the raw material 31 of the granule coupling plate 22 is molded. As an example, the material 31 is a plate material made of expanded polypropylene (PP) and having a shape of length × width × thickness 600 × 100 × 10 mm.

A cutter device 32 having a shape slightly larger than the material 31 is prepared.
The cutter device 32 includes a rectangular frame 33 that is slightly larger than the material 31, and includes a lattice-shaped cutter unit 34 in the internal space of the rectangular frame 33.
In the cutter unit 34, a plurality of vertical blades 35 and a plurality of horizontal blades 36 are arranged in a lattice shape, a blade edge 35 a is formed at the lower part of the vertical blade 35, and a blade edge 36 a is formed at the lower part of the horizontal blade 36. .
The cutter device 32 is lowered from above the material 31 toward the material 31 as indicated by an arrow.

In (b), the rectangular frame 33 of the cutter device 32 is fitted into the outer periphery of the material 31 (see (a)), and the cutter device 32 is pushed down as shown by an arrow.
As a result, the slits 28 shown in FIG. 5A are formed in a lattice shape in the material 31 by the vertical blades 35 and the horizontal blades 36 of the cutter unit 34.
After the slits 28 are formed in the material 31 by the cutter device 32, the cutter device 32 is removed from the material 31.

FIGS. 5A and 5B are diagrams for explaining an example in which the particle-binding plates according to the first embodiment are overlapped.
In (a), a plurality of granules 26 are formed by forming slits 28 in a lattice shape in a material 31 (see FIG. 4A). Thereby, the particle | grain combination board 22 is obtained from the raw material 31. FIG.
As described above, in the granule 26, the coupling portion 27 is coupled to the adjacent granules 26... By setting the depth of the slit 28 to H 1 -H 2.

  In (b), five granule bonding plates 22 are overlapped. In this state, the upper overlapping surfaces 22b of the lower particle-binding plates 22 and the lower overlapping surfaces 22c of the upper particle-binding plates 22 are in contact with each other so as to face each other.

FIGS. 6A and 6B are diagrams illustrating an example in which a shape holding member is wound around the circumferential surface of the overlapped granular material binding plates according to the first embodiment.
In (a), the shape-retaining member 24 is wound around the circumferential surfaces 22a of the overlapped granule coupling plates 22.
In (b), the shape-holding member 24 is wound around the peripheral surfaces 22a of the overlapped particle-binding plates 22 so that the overlapped particle-bonding plates 22 are integrally held by the shape-holding member 24. .
Thus, the impact-absorbing body 20 is obtained by holding the granule coupling plates 22.

Next, the operation of the shock absorber will be described with reference to FIGS.
First, an example in which the shock absorber collides with the rod-like object will be described with reference to FIGS.
FIGS. 7A and 7B are diagrams illustrating an example in which the shock absorber according to the first embodiment collides with a rod-like object.
In (a), when the vehicle body 10 moves as indicated by an arrow A, the shock absorber 20 moves together with the front bumper beam 15 toward the rod-like object 41 as indicated by an arrow A.

  In (b), the shock absorber 20 collides with the rod-like object 41. Since the rod-shaped object 41 is a cylindrical object having a relatively small outer diameter, a part of the shock absorber 20 (for example, the central portion) collides with the rod-shaped object 41.

Here, the plurality of particles 26 are coupled to each other. Therefore, at the initial stage of the collision, it is possible to prevent the particles 26... From diffusing (escaping) on both sides of the rod-like object 41.
In addition, the peripheral surfaces 22 a (see FIG. 3) of the granule coupling plates 22 are held by the shape holding member 24. Each particle | grain coupling | bonding plate 22 ... is prevented from moving along the mutual overlapping surfaces 22b and 22c. Therefore, at the initial stage of the collision, it is possible to more effectively suppress the particles 26...
By restraining the diffusion (escape) of the particles 26 at the initial stage of the collision, the restraint start time of the rod-like object 41 by the shock absorber 20 can be advanced.
In this state, the abutted shock absorber 20 continuously moves as indicated by an arrow A.

FIGS. 8A and 8B are diagrams illustrating an example in which an impact force acting on a rod-like object is absorbed by the impact absorber according to the first embodiment.
In (a), by suppressing the diffusion (escape) of the particles 26..., The particles 26 hitting the rod-shaped object 41 are the rod-shaped object 41 in the width direction (vehicle body width direction) and thickness of the shock absorber 20. It is pressed in the direction (vehicle longitudinal direction) as shown by arrow B.

Therefore, the particles 26... Hitting the rod-shaped object 41 are sheared at the bonding sites 27 and the bonds with the adjacent particles 26 are released.
As a result, the granules 26 that hit the rod-like object 41 slide and move while pressing force is applied to the adjacent granules 26.

Here, the peripheral surfaces 22a (see FIG. 3) of the granule coupling plates 22 are held by the shape holding member 24. Therefore, the granule 26 that has hit the rod-like object 41 can be slid in a state where the pressing force is suitably applied to the adjacent granule 26.
In addition, the particles 26 are formed in a cube, and the upper surface 26a, the lower surface 26b, and the first to fourth side surfaces 26c (see FIG. 3) are formed on a flat surface. Therefore, it is possible to secure a large contact area between the adjacent particles 26..., And the particles 26 that have come into contact with the rod-like object 41 can be favorably slid.
Thus, frictional energy can be efficiently generated by sliding the particles 26 in a state where the pressing force is suitably applied to the adjacent particles 26 in this manner.

The impact force is absorbed by the shear energy generated when the binding sites 27 are sheared and the friction energy generated when the particles 26 are slid.
In this state, the abutted shock absorber 20 continuously moves as indicated by an arrow A.
The bonding sites 27 are sheared and the granules 26 are individually independent. Therefore, as the shock absorber 20 moves in the direction of the arrow A, the individual individual particles 26 are pushed out to both sides of the rod-like object 41 as indicated by the arrow C.

  Here, the shock absorber 20 is accommodated in a sheet or cloth bag 21 (see FIG. 1). Therefore, when the individual individual particles 26 are pushed out to both sides of the rod-like object 41 as indicated by the arrow C, the particles 26 are kept in the bag body 21.

In (b), the independent individual particles 26 are pushed out to both sides of the rod-like object 41 as indicated by the arrow C, so that the impact force is absorbed by the kinetic energy of the independent individual particles 26.
In addition, when the individual individual particles 26 are pushed out to both sides of the rod-like object 41 as indicated by an arrow C, the particles 26 on both sides of the shock absorber 20 are crushed as illustrated.

Thus, when the shock absorber 20 collides with the rod-shaped object 41, the diffusion (escape) of the particles 26 is suppressed, and the impact force is absorbed by shear energy, friction energy, and kinetic energy.
Thereby, the impact force can be absorbed well and the impact force acting on the rod-like object 41 can be suppressed.

Next, an example in which the shock absorber collides with the wall-like object will be described with reference to FIGS.
FIGS. 9A and 9B are diagrams illustrating an example in which the shock absorber according to the first embodiment collides with a wall-like object.
In (a), when the vehicle body 10 moves as indicated by an arrow D, the shock absorber 20 moves toward the wall-like object 43 integrally with the front bumper beam 15 as indicated by an arrow D.

In (b), the shock absorber 20 collides with the wall-like object 43. Since the wall-like object 43 is a wide object, the entire surface of the shock absorber 20 collides with the wall-like object 43.
The plurality of granules 26 are coupled to each other, and the peripheral surfaces 22a of the granule coupling plates 22 are held by the shape holding member 24. Therefore, at the initial stage of the collision, it is possible to prevent the particles 26... From diffusing (escaping) on both sides of the wall-like object 43.
By suppressing the diffusion (escape) of the particles 26 at the initial stage of the collision, it is possible to advance the restraint start time of the wall-like object 43 by the shock absorber 20.
In this state, the abutting shock absorber 20 continuously moves as indicated by an arrow D.

FIGS. 10A and 10B are diagrams illustrating an example in which the impact force acting on the vehicle body is absorbed by the impact absorber according to the first embodiment.
In (a), when the shock absorber 20 collides with the wall-like object 43, the particles 26 are crushed.

In (b), the impact force is absorbed by the compressive strain energy generated when the granules 26 of the impact absorber 20 are crushed.
Thereby, the impact force can be absorbed well and the impact force acting on the vehicle body can be suppressed.

Next, the shock absorption amount of the shock absorber 20 will be described based on the graphs of FIGS. 11 and 12.
FIGS. 11A and 11B are graphs for explaining the relationship between the displacement and the absorption load in the shock absorber according to the first embodiment.
(A) shows an example in which the shock absorber collides with the rod-like object 41 (see FIG. 7A), and (b) shows an example in which the shock absorber collides with the wall-like object 43 (see FIG. 9A). Indicates. The vertical axis represents the absorption load (Kgf), and the horizontal axis represents the displacement (mm).
In the graphs (a) and (b), GL1 and graph GL3 indicate examples, and GL2 and graph GL4 indicate comparative examples.

An example is the shock absorber 20 of the first embodiment, and a comparative example is a conventional shock absorber 100 (see (a)).
The conventional shock absorber 100 is made of, for example, polypropylene (PP) having a substantially U-shaped cross section.

As shown to (a), according to graph GL1, an Example can ensure a large absorption load by the displacement of the shock absorber 20 increasing.
In the embodiment, when the shock absorber 20 collides with the rod-like object 41 (see FIG. 7A), the diffusion (escape) of the particles 26 is suppressed, and as described with reference to FIG. Absorb impact force with kinetic energy.
Thereby, a large absorption load can be secured according to the displacement of the shock absorber 20.

On the other hand, according to the graph GL2, in the comparative example, even if the displacement of the shock absorber 100 increases, it is difficult to ensure a large absorption load compared to the graph GL1.
In the comparative example, when the impact absorber 100 collides with the rod-like object 41, the impact force is absorbed only by the shape deformation energy having a substantially U-shaped cross section.
For this reason, even if the displacement of the shock absorber 100 increases, it is difficult to ensure a large absorption load as in the graph GL1.

As shown in (b), according to the graph GL3, in the embodiment, the displacement of the shock absorber 20 is increased, so that a relatively large absorption load can be secured.
In the embodiment, when the shock absorber 20 collides with the wall-like object 43 (see FIG. 9A), the diffusion (escape) of the particles 26 is suppressed, and the impact force is reduced by the compressive strain energy of the particles 26. It is possible to absorb.
Thereby, a large absorption load can be secured according to the displacement of the shock absorber 20.

On the other hand, according to the graph GL4, in the comparative example, it is difficult to ensure a large absorption load compared to the graph GL3 even if the displacement of the shock absorber 100 increases.
In the comparative example, when the impact absorber 100 collides with the wall-like object 43, the impact force is absorbed only by the shape deformation energy having a substantially U-shaped cross section.
For this reason, even if the displacement of the shock absorber 100 increases, it is difficult to ensure a large absorption load as in the graph GL3.

FIGS. 12A and 12B are graphs for explaining the relationship between the acceleration acting when the shock absorber according to the first embodiment collides with the rod-like object and time.
FIG. 11A shows the shock absorber 20 of the first embodiment (see FIG. 11A) as an example by a graph GL5, and FIG. 11B shows a conventional shock absorber 100 (see FIG. 11A). A graph GL6 is shown as a comparative example. The vertical axis represents acceleration (G), and the horizontal axis represents time.

As shown in (a), according to the graph GL5, the restraint start time of the rod-like object 41 by the shock absorber can be advanced by suppressing the diffusion (escape) of the particles in the initial stage of the collision.
Thereby, the acceleration G1 of a suitable magnitude | size can be made to act on the rod-shaped object 41 (refer Fig.7 (a)) in the collision initial stage.

In addition, when the impact absorber 20 collides with the rod-like object 41, the impact force is absorbed by the shear energy, friction energy, and kinetic energy of the particles 26.
Thereby, it becomes possible to apply a relatively uniform acceleration to the rod-like object 41 from the beginning of the collision, and the maximum acceleration G2 acting on the rod-like object 41 can be kept small.

As shown in FIG. 6B, according to the graph GL6, when the shock absorber 100 collides with the rod-like object 41 (see FIG. 7A), the impact force is obtained only by the shape deformation energy having a substantially U-shaped cross section. Absorb.
For this reason, it is difficult to apply a relatively uniform acceleration to the rod-like object 41 from the beginning of the collision, and it is difficult to reduce the maximum acceleration G3 acting on the rod-like object 41.

Next, a second embodiment will be described.
In addition, in the structure of 2nd Embodiment, the same code | symbol is attached | subjected about the same / similar member as the shock absorber 20 of 1st Embodiment, and description is abbreviate | omitted.
FIG. 13 is a perspective view showing a shock absorber (second embodiment) according to the present invention alone.
The shock absorber 50 of the second embodiment is obtained by joining the particle-binding plates 22... With an adhesive instead of the shape holding member 24, and the other configuration is the same as that of the shock absorber 20 of the first embodiment. It is.

Specifically, when the shock absorber 50 overlaps the five particle bonding plates 22..., The upper overlapping surface 22b of the lower particle bonding plate 22 and the upper particle bonding plate 22 The overlapping surface 22c (see FIG. 2) is bonded with an adhesive.
Thereby, the shape holding member 24 for integrating the granule bonding plates 22 can be eliminated, and the number of parts can be reduced.
Further, by integrating the particle body bonding plates 22 by bonding of an adhesive, the shock absorber 50 can be easily manufactured, and productivity can be increased.

  In the above-described embodiment, the example in which the shock absorbers 20 and 50 are applied to the front bumper beam 15 has been described. However, the present invention is not limited to this, and can be applied to other parts such as a rear bumper beam and a front pillar. It is.

  Moreover, in the said embodiment, although the example which formed the particle | grain coupling | bonding board 22 with the some particle | grain 26 ... by putting the grid-like slit 28 ... in the raw material 31 was demonstrated, it is not restricted to this, Individual It is also possible to form the particle bonding plate 22 by bonding the particles 26 with an adhesive.

  Furthermore, in the said embodiment, although the impact-absorbing bodies 20 and 50 which used 5 sheets as the several sheet | seat coupling | bonding plate 22 were illustrated, the number of the particle | grain coupling | bonding board 22 is not restricted to five sheets, For example, It is possible to arbitrarily select from two or more sheets.

  In the above-described embodiment, the example in which the shock absorbers 20 and 50 are bonded to the front bumper beam 15 with an adhesive has been described. However, the present invention is not limited thereto, and the shock absorbers 20 and 50 are bonded to the mounting bracket with an adhesive. The mounting bracket can be attached to the front bumper beam 15 with clips or bolts.

  Furthermore, although the said 1st Embodiment demonstrated the example which wraps the shape holding member 24 around the surrounding surface 22a ... of a plurality of granule coupling plates 22 ..., and hold | maintains the granule coupling plates 22 ..., it is not restricted to this. Instead, the bag body 21 that houses the shock absorber 20 can also serve as the shape holding member 24.

  The shock absorber of the present invention is particularly suitable for application to an automobile equipped with a front bumper beam, a rear bumper beam, and the like.

It is a perspective view which shows the front bumper beam provided with the shock absorber (1st Embodiment) which concerns on this invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a perspective view which shows the shock absorber which concerns on 1st Embodiment alone. It is a figure explaining the example which forms the granule coupling plate which concerns on 1st Embodiment. It is a figure explaining the example which overlaps the granule coupling plate which concerns on 1st Embodiment. It is a figure explaining the example which winds a shape maintenance member around the peripheral surface of the piled-up particle | grain coupling plate which concerns on 1st Embodiment. It is a figure explaining the example which the impact-absorbing body which concerns on 1st Embodiment collides with a rod-shaped object. It is a figure explaining the example which absorbs the impact force which acts on a rod-shaped object with the impact absorber which concerns on 1st Embodiment. It is a figure explaining the example which the impact-absorbing body which concerns on 1st Embodiment collides with a wall-shaped object. It is a figure explaining the example which absorbs the impact force which acts on a vehicle body with the impact absorber which concerns on 1st Embodiment. It is a graph explaining the relationship between the displacement and absorption load in the shock absorber according to the first embodiment. It is a graph explaining the relationship between the acceleration which acts when the shock absorber which concerns on 1st Embodiment collides with a rod-shaped object, and time. It is a perspective view which shows the shock absorber (2nd Embodiment) based on this invention alone.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle body, 15 ... Front bumper beam, 20, 50 ... Shock absorber, 22 ... Granule coupling plate, 22a ... Peripheral surface (end surface), 22b ... Upper overlapping surface (overlapping surface), 22c ... Lower overlapping surface (Overlapping surface), 24 ... shape retaining member, 26 ... granule, 26a ... upper surface (one surface), 26b ... lower surface (one surface), 27 ... binding site.

Claims (4)

In the shock absorber that absorbs the impact with a plurality of particles when the impact acts,
Having a plurality of granule bonding plates formed in a plate shape by bonding the plurality of granules together,
A shock absorber characterized in that a plurality of granule bonding plates are layered on each overlapping surface to form a shock absorber. The grains are formed into cubes, and one side of each grain is arranged to be flush with each other,
2. The impact absorber according to claim 1, wherein the overlapping surface is formed on one surface of each of the grains arranged so as to be flush with each other.   The shock absorber according to claim 1 or 2, wherein the plurality of granule bonding plates are joined at the overlapping surfaces.   2. A shape holding member for holding an end surface of each of the particle-binding plates is provided to prevent the plurality of particle-binding plates from moving along their overlapping surfaces. The impact absorber according to any one of -3.

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