JP2004291810A - Bumper absorber for pedestrian protection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the initial rise of a load level acting on a pedestrian colliding with a bumper. <P>SOLUTION: A cross sectional shape of the bumper absorber 20 for pedestrian protection is formed in a W-shape as viewed from a direction orthogonal to the longitudinal direction thereof (vehicle width direction). The direction of the W-shape along the longitudinal direction is reversed in predetermined intervals along the vehicle width direction. That is, in the bumper absorber 20 for pedestrian protection, an ordinary part 32 and a reversed part 34 of which directions of the W-shape along the longitudinal direction are opposite are alternately formed along the vehicle width direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bumper absorber for pedestrian protection, and more particularly to a bumper absorber for pedestrian protection for protecting a pedestrian in a vehicle such as an automobile in the event of a collision.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a bumper absorber of a vehicle such as an automobile, an energy absorber made of a foam has a substantially I-shaped cross-sectional shape, aiming at compatibility between pedestrian protection and performance originally required of a bumper. The configuration is known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-60-37457 [0004]
[Problems to be solved by the invention]
However, in this bumper absorber, when a load acts from the front of the vehicle at the time of a collision, the upper wall and the lower wall of the energy absorber having a substantially I-shaped cross section are compressed and deformed in the vehicle front-rear direction. As a result, the rise of the initial load level becomes dull, and the energy absorption amount decreases.
[0005]
An object of the present invention is to provide a bumper absorber for protecting a pedestrian capable of increasing an initial rise of a load level when a pedestrian collides with a bumper in consideration of the above fact.
[0006]
[Means for Solving the Problems]
The present invention according to claim 1 is a pedestrian protection bumper absorber made of a foamed molded body whose longitudinal direction is arranged in the bumper cover along the vehicle width direction and absorbs collision energy,
The cross-sectional shape orthogonal to the longitudinal direction is a W shape having a portion in which a front notch portion cut out from the vehicle front side and a rear notch portion cut out from the vehicle rear side overlap in the vehicle vertical direction. In addition, the front and rear directions of the W shape are reversed at predetermined intervals along the vehicle width direction.
[0007]
Therefore, in the initial stage when a load is applied to the bumper absorber for pedestrian protection, a load is generated in a direction in which one of the W shapes expands, and a load in a direction in which the other W shape narrows. I do. As a result, a shearing force is generated at the connecting portion at the adjacent W-shaped boundary in the opposite direction. Therefore, the initial rise of the load level can be increased.
[0008]
According to a second aspect of the present invention, in the bumper absorber for pedestrian protection according to the first aspect, the opposite W-shaped boundary surface is inclined in a die-cutting direction.
[0009]
Therefore, in addition to the contents described in the first aspect, since the W-shaped boundary surface in the opposite direction is inclined in the die-cutting direction, the die-cutting becomes easy. As a result, even if a slide cam is not used, it can be manufactured with a simple mold shape using a normal upper mold and lower mold.
[0010]
According to a third aspect of the present invention, there is provided a bumper absorber for pedestrian protection, which is disposed in a bumper cover in a longitudinal direction along a vehicle width direction and is made of a foamed molded body that absorbs collision energy.
The cross-sectional shape orthogonal to the longitudinal direction is a zigzag shape having a portion in which a front notch portion cut out from the vehicle front side and a rear notch portion cut out from the vehicle rear side overlap in the vehicle vertical direction. In addition, the zigzag shape in the front-rear direction is reversed at predetermined intervals along the vehicle width direction.
[0011]
Therefore, in the initial stage when a load is applied to the bumper absorber for pedestrian protection, a load is generated in one of the zigzag shapes in a direction in which it spreads, and a load in a direction in which the zigzag shape is reduced in the other direction. I do. As a result, a shearing force is generated at the connecting portion at the adjacent zigzag-shaped boundary in the opposite direction. Therefore, the initial rise of the load level can be increased.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
1st Embodiment of the bumper absorber for pedestrian protection in this invention is described according to FIGS.
[0013]
Note that the arrow UP in the figure indicates the vehicle body upward direction, and the arrow FR in the figure indicates the vehicle body front direction.
[0014]
As shown in FIG. 5, in the present embodiment, a front bumper 12 is disposed below the front end of the vehicle body 10 along the vehicle width direction.
[0015]
As shown in FIG. 3, the bumper reinforcement 14 of the front bumper 12 is disposed along the vehicle width direction, and has a cross section perpendicular to the longitudinal direction, that is, the cross-sectional shape as viewed from the vehicle width direction. The two rectangular closed cross-sections 16 and 18 are connected by a front wall 14A. A pedestrian protection bumper absorber 20 is disposed on the front side surface of the front wall 14A of the bumper reinforcement 14 along the vehicle width direction.
[0016]
As shown in FIG. 1, the cross-sectional shape of the pedestrian protection bumper absorber 20 viewed from a direction (vehicle width direction) orthogonal to the longitudinal direction is W-shaped, and the front-rear direction of the W shape is the vehicle width direction. At predetermined intervals along. That is, in the pedestrian protection bumper absorber 20, the general portion 32 having a length P1 along the vehicle width direction and the reversing portion 34 having a length P2 along the vehicle width direction are alternately arranged along the vehicle width direction. Is formed.
[0017]
As shown in FIG. 3, in the general portion 32 of the bumper absorber 20 for pedestrian protection, the cross-sectional shape viewed from the vehicle width direction has a front notch portion 22 cut out from the vehicle front side, and a cross-sectional shape from the vehicle rear side. The cutout upper rear notch 24 and the lower rear notch 26 have a W shape having a portion overlapping in the vehicle vertical direction. The front notch 22, the upper rear notch 24, and the lower rear The overlap length with the notch 26 is L.
[0018]
On the other hand, as shown in FIG. 4, in the reversing portion 34 of the pedestrian protection bumper absorber 20, a cross-sectional shape viewed from the vehicle width direction has a rear notch portion 23 cut out from the vehicle rear side, and a vehicle front side. The upper front notch 25 and the lower front notch 27 cut out from have a W shape having a portion overlapping in the vehicle vertical direction, and the rear notch 23, the upper front notch 25, The overlap length with the lower front notch 27 is L.
[0019]
The pedestrian protection bumper absorber 20 is made of a material having high compressive strength and bending strength, for example, a synthetic resin foam molded article such as a polystyrene resin, a polyethylene resin, a polypropylene resin, a polyester resin, and a styrene-modified polyethylene resin. And absorbs collision energy. In particular, an in-mold molded article of a styrene-modified polyethylene resin (styrene component 50 to 70% by weight) bead foam is preferred.
[0020]
As shown in FIG. 3 and FIG. 4, the bumper reinforcement 14 and the pedestrian protection bumper absorber 20 are covered with a bumper cover 36, and the front wall portion 36 </ b> A of the bumper cover 36 and the pedestrian protection bumper absorber 20. The front wall portion 20A is opposed. Also, the rear wall 20B of the bumper absorber 20 for pedestrian protection abuts on the front wall 14A of the bumper reinforcement 14, and the upper wall 20C and the lower wall 20D of the bumper absorber 20 for pedestrian protection are different from each other. , W-shaped upper and lower portions.
[0021]
Next, the operation of the present embodiment will be described.
[0022]
In the present embodiment, when a pedestrian collides with the front bumper 12, a load acts on the pedestrian protection bumper absorber 20 from the front of the vehicle via the front wall portion 36A of the bumper cover 36. At this time, in the initial stage when the load acts on the pedestrian protection bumper absorber 20, as shown in FIG. A load is generated in a direction (the direction of the arrow A in FIG. 1) in which the and the lower wall 20D spread. On the other hand, a load is generated in the general portion 32 of the pedestrian protection bumper absorber 20 in the direction in which the upper wall portion 20C and the lower wall portion 20D are narrowed (the direction of arrow B in FIG. 1).
[0023]
As a result, as shown in FIG. 2, the intersection of the general portion 32 and the reversing portion 34 of the pedestrian protection bumper absorber 20, that is, the connecting portion S (FIG. (A portion indicated by oblique lines) generates a shearing force.
[0024]
For this reason, in this embodiment, as shown by the solid line in FIG. 6, the initial rise of the load level when an impact load acts on the pedestrian protection bumper absorber 20 from the front of the vehicle is shown by a two-dot broken line in FIG. When the front-rear direction of the W shape shown is not reversed at a predetermined interval along the vehicle width direction, that is, when the pedestrian protection bumper absorber 20 is entirely the general portion 32 along the vehicle width direction. Can be increased, and a decrease in the amount of energy absorption can be prevented.
[0025]
In the latter stage of the deformation, the connecting portion S is broken by the shearing force and the W shape is expanded, so that the remaining thickness of the crushed portion is reduced. For this reason, the timing at which the bottomed load occurs can be delayed, and the rise of the impact load acting on the pedestrian colliding with the bumper can be suppressed.
[0026]
Next, a second embodiment of the bumper absorber for pedestrian protection according to the present invention will be described with reference to FIGS.
[0027]
The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0028]
As shown in FIG. 7, in the present embodiment, the boundary wall portion 40 between the general portion 32 and the reversing portion 34 of the pedestrian protection bumper absorber 20 has the die-cutting direction (the arrow C direction and the arrow D direction in FIG. 7). It is inclined.
[0029]
As shown in FIG. 8, the boundary wall portion 40 of the pedestrian protection bumper absorber 20 has an inclination angle θ1 with respect to the forward die-cutting direction (the direction of arrow C in FIG. 7), and the die is moved forward. A hole is not formed near the boundary wall portion 40 when it is pulled out. Further, the boundary wall portion 40 has an inclination angle θ2 (θ1 = θ2) with respect to the rearward die-cutting direction (the direction of arrow D in FIG. 7). There is no hole in the vicinity.
[0030]
Therefore, in the present embodiment, it is possible to manufacture a simple mold using a normal upper mold and lower mold without using a slide cam. Therefore, the manufacturing cost can be reduced.
[0031]
In the above, the present invention has been described in detail with respect to a specific embodiment, but the present invention is not limited to such an embodiment, and various other embodiments are possible within the scope of the present invention. Some will be apparent to those skilled in the art. For example, in the second embodiment, the inclination angles θ1 and θ2 are equal (θ1 = θ2), but the inclination angles θ1 and θ2 may be different angles (θ1 ≠ θ2).
[0032]
In each of the above embodiments, the cross-sectional shape of the pedestrian protection bumper absorber 20 as viewed from a direction (vehicle width direction) orthogonal to the longitudinal direction (vehicle width direction) is W-shaped. The cross-sectional shape viewed from a direction perpendicular to the vehicle (vehicle width direction) is not limited to the W shape, but may be another zigzag shape including the V shape.
[0033]
【The invention's effect】
The present invention according to claim 1 is a pedestrian protection bumper absorber that is disposed in a bumper cover in a longitudinal direction along a vehicle width direction and is made of a foam molded body that absorbs collision energy, and is orthogonal to the longitudinal direction. The cross-sectional shape is a W shape having a portion where a front notch portion cut out from the front side of the vehicle and a rear notch portion cut out from the rear side of the vehicle overlap in the vehicle vertical direction. Since the direction is reversed at predetermined intervals along the vehicle width direction, there is an excellent effect that the initial rise of the load level when a pedestrian collides with the bumper can be increased.
[0034]
According to the second aspect of the present invention, in the pedestrian protection bumper absorber according to the first aspect, since the opposite W-shaped boundary surface is inclined in the die-cutting direction, it can be manufactured with a simple die shape. It has an excellent effect.
[0035]
According to a third aspect of the present invention, there is provided a bumper absorber for pedestrian protection, comprising a foam molded body having a longitudinal direction arranged along a vehicle width direction in a bumper cover and absorbing collision energy, wherein the bumper absorber is orthogonal to the longitudinal direction. The cross-sectional shape is a zigzag shape having a portion in which the front notch portion cut out from the front side of the vehicle and the rear notch portion cut out from the rear side of the vehicle overlap in the vertical direction of the vehicle, and the front and rear of the zigzag shape. Since the direction is reversed at predetermined intervals along the vehicle width direction, there is an excellent effect that the initial rise of the load level when a pedestrian collides with the bumper can be increased.
[Brief description of the drawings]
FIG. 1 is a perspective view of a pedestrian protection bumper absorber according to a first embodiment of the present invention, as viewed obliquely from the front of a vehicle.
FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG.
FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG.
FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 5;
FIG. 5 is a perspective view showing the vehicle body to which the bumper absorber for pedestrian protection according to the first embodiment of the present invention is applied, as viewed obliquely from the front of the vehicle.
FIG. 6 is a graph showing load characteristics of a pedestrian protection bumper absorber.
FIG. 7 is a perspective view showing a pedestrian protection bumper absorber according to a second embodiment of the present invention, as viewed obliquely from the front of the vehicle.
FIG. 8 is an enlarged sectional view taken along line 8-8 in FIG. 7;
[Explanation of symbols]
12 front bumper 14 bumper reinforcement 20 pedestrian protection bumper absorber 22 front notch 23 of pedestrian protection bumper absorber rear notch 24 upper upper notch 25 of pedestrian protection bumper absorber Upper front notch 26 of pedestrian protection bumper absorber Lower rear notch 27 of pedestrian protection bumper absorber Lower front notch 32 of pedestrian protection bumper absorber General part 34 of pedestrian protection bumper absorber Reversing part of pedestrian protection bumper absorber

Claims (3)

A pedestrian protection bumper absorber made of a foamed molded body whose longitudinal direction is arranged in the bumper cover along the vehicle width direction and absorbs collision energy,
The cross-sectional shape orthogonal to the longitudinal direction is a W shape having a portion in which a front notch portion cut out from the vehicle front side and a rear notch portion cut out from the vehicle rear side overlap in the vehicle vertical direction. A pedestrian protection bumper absorber characterized in that the front and rear directions of the W shape are reversed at predetermined intervals along the vehicle width direction. The bumper absorber for pedestrian protection according to claim 1, wherein the inverted W-shaped boundary surface is inclined in a die-cutting direction. A pedestrian protection bumper absorber made of a foamed molded body whose longitudinal direction is arranged in the bumper cover along the vehicle width direction and absorbs collision energy,
The cross-sectional shape orthogonal to the longitudinal direction is a zigzag shape having a portion in which a front notch portion cut out from the vehicle front side and a rear notch portion cut out from the vehicle rear side overlap in the vehicle vertical direction. A zigzag front-rear direction of the zigzag shape is reversed at predetermined intervals along the vehicle width direction.

Images