JP2004345424A - Impact energy absorbing device for vehicle bumpers - Google Patents

Abstract

An object of the present invention is to provide a collision energy absorbing device for a vehicle bumper that can improve the efficiency of absorbing collision energy in an extremely limited space and improve the protection performance against pedestrians while keeping the production cost low.
Kind Code: A1 A compression energy absorbing material for absorbing collision energy acting on a bumper facer by compressive deformation and a buckling allowable space for allowing buckling deformation are formed on at least one surface side. A buckling energy absorbing member 11 composed of a plate-shaped member that is arranged in parallel with the compression energy absorbing member 12 with the width direction facing the vehicle front-rear direction and absorbs collision energy acting on the bumper fascia 4 by buckling deformation; A front fixed holding member 15 is provided on the inner surface of the fascia 4 so as to protrude and holds the front ends of the energy absorbing members 11 and 12.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a collision energy absorbing device for a vehicle bumper.
[0002]
[Prior art]
As a collision energy absorbing device for a vehicle bumper, various devices incorporating a collision energy absorbing material in a space between a bumper reinforcement and a bumper fascia have been proposed and put to practical use in order to enhance protection performance against pedestrians. .
[0003]
For example, a collision energy absorbing material made of a polypropylene resin foam is provided between a bumper reinforcing material disposed at a front end of a vehicle and a bumper fascia covering the bumper reinforcing material, and the collision energy absorbing material is compressed and deformed. By doing so, a vehicle bumper configured to absorb the collision energy acting on the bumper (for example, see Patent Literature 1), a hollow portion is formed at the front of the bumper by double front and rear partitions, and the front and rear partitions are formed. A plurality of ribs protruding from one of the partitions are spaced apart from the other partition, and if the bumper collides with an obstacle relatively weakly, the front wall of the bumper flexes and the collision energy is absorbed. In the event of a strong collision, a bumper for a vehicle configured to absorb the collision energy by buckling deformation of the rib has been proposed. For example, see Patent Document 2.).
[0004]
On the other hand, it is known that the collision energy acting on the bumper can be efficiently absorbed by setting the impact force acting on the collision energy absorbing material to be substantially uniform over the entire period of the collision energy absorption period by the bumper. (For example, see Patent Document 3).
[0005]
[Patent Document 1]
JP-A-2002-144989 (page 4, page 5, FIG. 1)
[Patent Document 2]
JP-A-57-37051 (pages 4 to 6, FIGS. 2 and 5)
[Patent Document 3]
See Japanese Patent Application Laid-Open No. 2002-172987 (pages 2 and 3, FIGS. 24 to 28)
[0006]
[Problems to be solved by the invention]
As seen in Patent Literatures 1 and 2, the energy absorbing structure of a conventional bumper is basically formed by compressive deformation of a compression energy absorbing material such as a foamed molded product or buckling energy absorbing material such as a rib. A structure that absorbs collision energy by buckling deformation is adopted. However, as shown in FIG. 5, in the compression energy absorbing material, as the displacement increases, the acting impact force tends to increase, and in the buckling energy absorbing material, in the initial stage where the impact force acts. Then, the acting impact force rapidly increases and reaches a peak value, and thereafter, the impact force tends to rapidly decrease. By the way, in order to enhance the safety performance against pedestrians, it is necessary to set the peak value of the impact force low enough not to cause fatal damage to the human body. However, it is not possible to sufficiently absorb the collision energy in the early stage of the absorption of the collision energy, and the buckling energy absorbing material cannot sufficiently absorb the collision energy in the late stage of the absorption of the collision energy after the impact force reaches a peak value. There is. However, if the amount of displacement of the energy absorbing material can be set large, the amount of absorption of collision energy also increases accordingly.However, when applied to vehicles such as automobiles, the energy is stored in an extremely limited space. Since it is necessary to dispose an absorbing material, it is difficult to sufficiently absorb the collision energy while setting the peak value of the impact force low.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a collision energy absorbing device for a vehicle bumper that can improve the efficiency of absorbing collision energy in an extremely limited space and improve the protection performance against pedestrians while keeping manufacturing costs low. .
[0008]
Means for Solving the Problems and Their Functions
As shown in FIG. 5, as the displacement increases in the compression energy absorbing material, the acting impact force tends to increase, and in the buckling energy absorbing material, it acts in the initial stage when the impact force acts. The impact force rapidly increases and reaches a peak value, and thereafter, the impact force tends to decrease rapidly. On the other hand, in order to enhance pedestrian protection performance, it is necessary to set so that the impact force on the pedestrian does not become excessively large. The present inventors have conducted intensive studies on the configuration of a collision energy absorbing device for a vehicle bumper that can improve the protection performance of pedestrians. As a result, the collision energy absorbing characteristics of the compression energy absorbing material and the collision energy absorbing By combining this with the absorption characteristics, it is possible to maintain the pedestrian protection performance by maintaining the impact force against the collision energy absorption period of both energy absorbing materials at the target value that can protect pedestrians over the entire period. The present invention was completed based on the idea that a collision energy absorbing device for a vehicle bumper capable of maximally absorbing the collision energy can be realized.
[0009]
(Claim 1)
A collision energy absorbing device for a vehicle bumper according to the present invention is a collision energy absorbing device for a vehicle bumper that is installed in a space between a bumper fascia and a bumper reinforcement, and is provided on a front side of the bumper reinforcement. A compression energy absorbing material arranged along the vehicle width direction and absorbing collision energy acting on the bumper fascia by compressive deformation, and at least one surface disposed along the front side of the bumper reinforcement in the vehicle width direction. The buckling deformation is applied to the compression energy absorbing material with the width direction facing the front and rear direction of the vehicle so that a buckling allowable space is formed on the side to allow buckling deformation. Buckling energy absorbing material comprising a plate-like member absorbing by A front fixed holding member that is provided in a protruding manner on the inner surface and holds front ends of both energy absorbing materials, and the collision energy acting on the bumper fascia by cooperation of the compression energy absorbing material and the buckling energy absorbing material. Is to absorb.
[0010]
As described above, in the compression energy absorbing material, the applied impact force tends to increase as the displacement increases. In the buckling energy absorbing material, the applied impact force in the initial stage where the impact force is applied. Rapidly increases and reaches a peak value, after which the impact force tends to decrease rapidly. In contrast, in the collision energy absorbing device for a vehicle bumper according to the present invention, the compression energy absorbing material and the buckling energy absorbing material are combined to absorb the collision energy. It is possible to maintain the impact force on the collision energy absorbing device substantially constant over the period, and it is possible to set the collision energy absorbing characteristic to a substantially ideal form. Therefore, by setting the impact force on the collision energy absorbing device to be a target value capable of protecting the pedestrian, a small installation space for the collision energy absorbing device is ensured while sufficiently securing the pedestrian protection performance. Within, the collision energy can be absorbed as efficiently as possible.
[0011]
In addition, in this collision energy absorbing device, the front end portions of both energy absorbing materials can be fixedly held to the bumper fascia by the front fixed holding member, so that the stability of the posture of both energy absorbing materials is enhanced, and It is possible to prevent the posture of the buckling energy absorbing material from being finely changed due to vibration at the time of collision or the like, and to prevent the occurrence of poor compression or buckling due to a change in the posture of the two energy absorbing materials. In particular, since the buckling energy absorbing material greatly changes the form of buckling deformation due to its posture variation, fixing and holding the front end of the buckling energy absorbing material to the bumper fascia maintains the energy absorption efficiency optimally. Preferred above.
[0012]
Furthermore, a buckling allowable space is formed on at least one surface side of the buckling energy absorbing material, so that the buckling deformed buckling energy absorbing material does not interfere with the compression energy absorbing material. The buckling energy absorbing material can be prevented from being poorly deformed due to contact with the buckling energy absorbing material, and the buckling energy absorbing material can be prevented from interfering with each other, so that the buckling energy does not increase in the longitudinal direction of the vehicle body. By buckling the absorber, the amount of compressive deformation of the compression energy absorber can be set as large as possible.
[0013]
Furthermore, since the buckling energy absorbing material and the compression energy absorbing material are arranged in the vehicle width direction along the front side of the bumper reinforcement, the collision load acting on both energy absorbing materials can be surely secured by the bumper reinforcement. , And even if a collision load acts on an arbitrary position in the vehicle width direction of the bumper fascia, the collision energy can be efficiently absorbed by the two energy absorbing materials.
[0014]
(Claims 2 and 3)
Here, the front fixed holding member can be formed as a separate member from the bumper fascia. However, when integrally formed with the bumper fascia, both the production cost and the manufacturing cost of the collision energy absorbing device can be suppressed. This is preferable because the posture of the energy absorbing material can be stabilized. Further, as the front fixed holding member, a rib-shaped front fixed holding member extending to both upper and lower sides of the respective tip portions of the buckling energy absorbing material and the compression energy absorbing material may be provided on the inner surface of the bumper fascia. This is a preferred embodiment.
[0015]
(Claim 4)
A rear connecting member for connecting the rear part of the buckling energy absorbing material and the rear part of the compressive energy absorbing material is provided. It is preferable to restrict the fluctuation of the energy absorption material so as to more effectively prevent the occurrence of poor compression or poor buckling due to a change in the posture of the two energy absorbing members.
[0016]
(Claim 5)
As the rear connecting member, a plurality of columnar members may be provided at intervals. In this case, the stability of the posture of the two energy absorbing members can be further improved. Moreover, since a plurality of pillar-shaped rear connecting members are arranged at an interval from each other, compression deformation of the compression energy absorbing material is somewhat hindered in a portion where the rear connecting members are disposed. Between the rear connecting members, substantially the entire width of the compression energy absorbing member in the vehicle longitudinal direction is compressed and deformed, so that the collision energy can be effectively absorbed. In other words, at the position where the rear connecting member is provided, the rear connecting member is arranged between the bumper fascia and the bumper reinforcement, and the rear connecting member also tends to deform in the vehicle front-rear direction. The compression energy absorbing material is less likely to be compressed and deformed by the thickness of the connecting member, but since there is no obstacle between the rear connecting members, almost all the width of the compressed energy absorbing material in the vehicle longitudinal direction is compressed and deformed. Thus, the collision energy can be effectively absorbed.
[0017]
(Claim 6)
The rear connection member can be formed as a separate member from the buckling energy absorbing material or the compression energy absorbing material.However, in order to reduce the number of components of the collision energy absorbing device, the rear connecting member is compressed. It is preferable to provide the energy absorbing material or the buckling energy absorbing material integrally.
[0018]
(Claim 7)
In order to improve the stability of the buckling energy absorber immediately before or at the time of the collision and to prevent poor buckling of the buckling energy absorber, rear connection members are provided on both upper and lower sides of the buckling energy absorber, It is preferable to provide the rear connection member on the upper surface side and the rear connection member on the lower surface side of the buckling energy absorbing member so as to be continuous in the vehicle body vertical direction with the buckling energy absorbing member interposed therebetween.
[0019]
(Claim 8)
When the compression energy absorbing material is formed in a plate shape, it is possible to easily obtain the combined characteristics of the collision energy absorbing characteristics of the two energy absorbing materials, and the design of the collision energy absorbing device is facilitated.
[0020]
(Claim 9)
In order to set the collision energy absorption characteristics of the collision energy absorption device in a well-balanced manner, a plurality of at least one of the compression energy absorber and the buckling energy absorber can be provided.
[0021]
(Claim 10)
In order to reliably receive the load acting on the buckling energy absorbing material at the rear of the vehicle body in the event of a collision with the bumper reinforcement and buckle and deform the buckling energy absorbing material, the buckling energy absorbing material is used as a bumper reinforcement. Preferably, it is provided substantially perpendicular to the front surface.
[0022]
(Claim 11)
The buckling energy absorbing material and the compression energy absorbing material can be provided substantially in parallel. In this case, since the deformation amounts of the two energy absorbing materials are substantially the same, it is possible to easily obtain the combined characteristics of the collision energy absorbing characteristics of the two energy absorbing materials, and the design of the collision energy absorbing device is facilitated. .
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 3, a pair of left and right front side frames 2 extending in the front-rear direction of the vehicle body is provided at a front portion of the vehicle body 1. The bumper reinforcement 3 is connected to the bumper reinforcement 3, and a bumper fascia 4 is provided on the front side of the bumper reinforcement 3. The collision energy absorbing device 10 for a vehicle bumper according to the present invention includes the bumper reinforcement 3 and the bumper reinforcement 3. It is assembled in a space 5 between the upper portions of the shears 4. A front cross member 6 extending in the vehicle width direction is provided below and slightly behind the bumper reinforcement 3, and a lower cushioning member 7 extending to near the bumper fascia 4 is provided on the front cross member 6. The lower cushioning member 7 is for preventing a pedestrian or the like from being caught in the lower side of the vehicle body, and is not directly related to the present invention. Further, the collision energy absorbing device 10 can be similarly applied to a rear bumper.
[0024]
The front bumper 8 includes a bumper fascia 4, a collision energy absorbing device 10, and a bumper reinforcement 3. A collision load at the time of a frontal collision is transmitted to the collision energy absorbing device 10 via the bumper fascia 4, When both are deformed, the bumper reinforcement 3 is received. When a larger collision load is applied, a collision load is applied to the bumper reinforcement 3 and the bumper reinforcement 3 is deformed.
[0025]
As shown in FIGS. 1 to 4, the collision energy absorbing device 10 includes a plate-shaped buckling energy absorber 11 that absorbs the collision energy acting on the front bumper 8 by buckling deformation, and a collision energy acting on the front bumper 8. A plate-shaped compression energy absorbing material 12 that absorbs by compressive deformation, and front ends of the two energy absorbing materials 11 and 12 are provided in a protruding manner on the inner surface of the bumper fascia 4 in order to fix and hold the same to the bumper fascia 4. A part fixing holding member 15 and a rear connecting member 13 provided at intervals in the vehicle width direction to fix and hold the rear end of the buckling energy absorbing material 11 to the rear end of the compression energy absorbing material 12. Have.
[0026]
The compression energy absorbing material 12 is formed of an elongated plate-shaped member made of a synthetic resin foam molded body, and is provided in a space 5 formed by the bumper reinforcement 3 and the bumper facer 4 in front of the bumper reinforcement 3. The bumper is provided substantially horizontally along the entire length thereof, and is arranged substantially perpendicular to the front surface of the bumper reinforcement 3. The compression energy absorbing material 12 may be formed in a shape other than the plate shape, and may be formed in a shape that is compatible with the space 5 formed by the bumper reinforcement 3 and the bumper facer 4, for example.
[0027]
A pair of compression energy absorbing members 12 are provided at an interval in the up-down direction, and a locking member such as a pin, an uneven fitting portion, an adhesive, a double-sided tape, or a combination thereof is provided on the front surface of the bumper reinforcement 3. That has been fixed. The length of the compression energy absorbing material 12 in the vehicle width direction is set to be substantially the same as the length of the bumper reinforcement 3, and the length in the front-rear direction of the vehicle body is adapted to the gap between the bumper reinforcement 3 and the bumper fascia 4. Set to length. The front end of the compression energy absorbing material 12 is formed in a gentle curved shape along the inner surface of the bumper fascia 4, and the front end of the compression energy absorbing material 12 is disposed in close proximity to the bumper fascia 4 with almost no gap. It is configured so that the collision energy can be absorbed by effectively utilizing the space. The front end of the compression energy absorbing material 12 is fixedly held to the bumper fascia 4 as described later, so that the rear end does not necessarily need to be fixed to the bumper reinforcement 3.
[0028]
As the compression energy absorbing material 12, any material such as a synthetic resin material or a synthetic rubber material can be used as long as it can absorb collision energy by compressive deformation. Specifically, it can be formed of a foamed molded body made of a polystyrene resin, a polyolefin resin such as a polyethylene resin or a polypropylene resin, or a copolymer of these synthetic resins.
[0029]
When the compression energy absorbing material 12 is formed by the bead method, since the material itself has flexibility, for example, ethylene propylene random polypropylene resin, ethylene propylene block polypropylene resin, homopolypropylene ethylene propylene butene random terpolymer, linear Polyolefin resins such as linear low density polyethylene (LLDPE) and crosslinked low density polyethylene (crosslinked LDPE) can be suitably used. The expansion ratio of the foamed molded product depends on the material of the raw material beads, but is preferably in the range of 3 to 150 times. Specifically, when using pre-expanded beads made of a polyolefin-based synthetic resin material, if the expansion ratio is too low, it is difficult to compressively deform, and the impact force becomes large. Since the collision energy cannot be absorbed, the energy should be twice or more and 90 or less, and preferably two or more and 60 or less.
[0030]
The buckling energy absorbing member 11 is formed of a solid and elongated plate-shaped member made of a synthetic resin material, and is provided substantially horizontally along the front side of the bumper reinforcement 3 over substantially the entire length thereof. It is arranged substantially perpendicular to the front surface. The buckling energy absorbing member 11 is provided at a substantially middle position between the upper and lower compressive energy absorbing members 12 and substantially in parallel with the compressive energy absorbing member 12. Are integrally connected to the compression energy absorbing material 12 of the first embodiment. The planar shape of the buckling energy absorbing material 11 is formed to be substantially the same shape as the compression energy absorbing material 12, the rear end thereof is disposed substantially along the bumper reinforcement 3, and the front end thereof is formed of the bumper fascia 4. It is arranged along the inner surface without any gap.
[0031]
A pair of upper and lower buckling allowable spaces 14 is formed between the upper and lower compression energy absorbing members 12 and the buckling energy absorbing members 11, and the buckling energy absorbing members 11 buckle in the buckling allowable spaces 14. Interference between the buckled energy absorbing material 11 and the compressed energy absorbing material 12 that are buckled is avoided, and the buckling energy absorbing material 11 is configured to be smoothly and reliably buckled. Since the buckling energy absorbing member 11 smoothly and reliably buckles in this way and prevents bulking in the longitudinal direction of the vehicle body due to poor buckling, the amount of compressive deformation of the compressive energy absorbing member 13 is set large accordingly. it can. Further, poor compression deformation of the compression energy absorbing material 13 due to the contact of the buckling energy absorbing material 11 with the compression energy absorbing material 13 is prevented. In order to obtain such an effect, the height of the buckling allowable space 14 (the interval between the buckling energy absorbing material 11 and the compression energy absorbing material 12) is set to one of the length of the buckling energy absorbing material 11 in the vehicle longitudinal direction. It is preferable to set the height to / 3 or more. The buckling allowable space 14 may be provided on both the upper and lower sides of the buckling energy absorbing material 11 as described above, but is provided only on the bent side of the buckling energy absorbing material 11 after buckling as described later. This is preferable for effectively utilizing the space 5 formed by the bumper reinforcement 3 and the bumper fascia 4.
[0032]
As the buckling energy absorbing material 11, a material made of a synthetic resin material, a high-density foam, a metal material, or the like can be adopted as long as it can absorb collision energy by buckling deformation. Specifically, a synthetic resin material composed of a polystyrene resin, a polyolefin resin such as a polyethylene resin or a polypropylene resin, a copolymer of these synthetic resins, or a high-density foam thereof can be suitably used. In the case of using a high-density foam, it is preferable to set the expansion ratio to 20 times or less so that the buckling energy absorbing material 11 buckles reliably. The buckling energy absorbing material 11 made of such a high-density foam can be formed by the bead method similarly to the compression energy absorbing material 12 described above.
[0033]
As the buckling energy absorbing material 11, besides using the flat plate-shaped member as described above, ribs extending in at least one of the upper and lower surfaces in the longitudinal direction of the vehicle body for the purpose of preventing buckling failure. It is also possible to use one having a projection in the shape of a wave, or one having a wavy shape that oscillates in the vertical direction of the vehicle body. If the buckling energy absorbing material 11 is arranged substantially perpendicular to the front surface of the bumper reinforcement 3, it is not always necessary to arrange the buckling energy absorbing material 11 horizontally. You may let it.
[0034]
When selecting the two energy absorbing materials 11 and 12, from the viewpoint of recycling, it is preferable that both the compression energy absorbing material 12 and the buckling energy absorbing material 11 are made of a polypropylene resin.
[0035]
Next, a front fixed holding member and a rear connecting member for fixing and holding the energy absorbing members 11 and 12 to the vehicle body will be described.
The front fixed holding member 15 is made of a rib-shaped member formed to protrude rearward from the inner surface of the bumper fascia 4, and at positions corresponding to the upper and lower sides of the front end of the energy absorbing materials 11 and 12, The energy absorbing members 11 and 12 are provided substantially horizontally over substantially the entire length of the vehicle in the vehicle width direction, and the front end portions of the energy absorbing members 11 and 12 are fitted and mounted between upper and lower front fixed holding members 15, respectively. It is fixed and held on the bumper fascia 4 by an external adhesive or the like.
[0036]
The front fixed holding member 15 is preferably formed integrally with the bumper fascia 4 in order to reduce the number of parts as much as possible and to reduce the manufacturing cost of the collision energy absorbing device 10, but it is preferable to form the front fixed holding member 15 as a separate member. It may be fixed to the inner surface of the bumper fascia 4 with an adhesive or the like. In addition, although it is preferable to form them continuously in the vehicle width direction, they may be formed intermittently. Further, it is preferable to provide the upper and lower front fixing holding members 15 on both upper and lower sides of each of the energy absorbing members 11 and 12, but both may be omitted. Further, as the front fixed holding member, a plurality of rod-shaped members projecting rearward from the vehicle body at regular intervals in the vehicle width direction may be provided on the inner surface of the bumper fascia 4.
[0037]
The rear connecting member 13 is formed of a columnar member integrally formed with the compression energy absorbing material 12, and these three buckling energy absorbing materials 11 are fixedly held at substantially intermediate positions between the upper and lower compression energy absorbing materials 12. The two energy absorbing members 12, 12, 11 are integrally connected, and a plurality of energy absorbing members are formed at the rear of the compressed energy absorbing member 12 so as to protrude vertically in the vehicle width direction at intervals of, for example, 100 to 300 mm. I have. The front end of the rear connecting member 13 is fixed to the buckling energy absorbing material 11 via an adhesive or the like, whereby the rear portions of the upper and lower compression energy absorbing materials 12 and the rear portion of the buckling energy absorbing material 11 are integrally connected. Thus, the unstable behavior of the buckling energy absorbing material 11 immediately before or at the time of the collision is restricted.
[0038]
The rear connecting member 13 can be formed in any cross-sectional shape such as a square, a circle, or an ellipse, and its horizontal cross-sectional area is buckled so that buckling deformation of the buckling energy absorbing material 11 is smooth. The length in the front-rear direction of the vehicle body is set to be as short as possible so that the coupling strength between the energy absorbing material 11 and the compressive energy absorbing material 12 is as small as possible and the compression deformation of the compressive energy absorbing material 12 is not hindered. Is preferred.
[0039]
Although the stability of the buckling energy absorbing member 11 is slightly reduced, omitting the rear connecting member 13 as in the collision energy absorbing device 10A shown in FIG. 6 is also within the scope of the present invention. Further, the rear connecting members 13 are formed at regular intervals in the vehicle width direction in order to sufficiently secure the amount of compressive deformation of the compression energy absorbing material 12, but they may be formed in a continuous plate shape in the vehicle width direction. It is. Further, the rear connecting member 13 can be formed as a separate member from the compression energy absorbing material 12 and the buckling energy absorbing material 11, or can be formed integrally with the buckling energy absorbing material 11. is there. In this case, by connecting the buckling energy absorbing members 11 to each other by the rear connecting member, the plurality of buckling energy absorbing members 11 can be arranged in parallel without sandwiching the compression energy absorbing members 12 therebetween. . Further, as shown in FIG. 2, the rear connecting members 13 provided on the upper and lower compression energy absorbing members 12 may be set at the same position in plan view, but may be set at different positions. It is.
[0040]
Next, the operation of the collision energy absorbing device 10 will be described.
In the conventional collision energy absorbing device, when a collision load acts on the front bumper, as shown in FIG. 5, in the case of the compression energy absorbing material alone, the impact force acting increases as the displacement increases. In the case of a buckling energy absorbing material alone, the impact force acting rapidly increases and reaches a peak value at the initial stage when a collision load is applied, and thereafter the impact force tends to decrease rapidly Will be shown. However, in this collision energy absorbing device 10, since the compression energy absorbing material 12 and the buckling energy absorbing material 11 are provided side by side, the impact force to both energy absorbing materials 11, 12 is combined as shown in FIG. Thus, the impact force on the collision energy absorbing device 10 becomes substantially uniform over substantially the entire period of the collision energy absorbing device 10 absorbing the collision energy, and the collision energy absorbing characteristics can be set to a substantially ideal form. For this reason, by setting the impact force on the collision energy absorbing device 10 to be a target value capable of protecting the pedestrian, it is possible to sufficiently secure the protection performance of the pedestrian and to reduce the slight impact of the collision energy absorbing device 10. In the installation space, it is possible to absorb the collision energy as efficiently as possible.
[0041]
When designing the collision energy absorbing device 10, it is necessary to set the materials and shapes of both energy absorbing materials 11 and 12, the expansion ratio, and the size of each part so as to obtain such a collision energy absorbing characteristic. Become. Further, by setting the expansion ratio, the material, the shape, and the size of each part of the two energy absorbing materials 11 and 12, the collision energy absorption characteristics of the collision energy absorbing device 10, that is, the energy absorption curve (the “synthetic” curve in FIG. 5) can be freely set. It becomes possible to design.
[0042]
For example, the length of the two energy absorbing members 11 and 12 in the front-rear direction of the vehicle body 1 is adjusted so that the two energy absorbing members 11 and 12 start the energy absorbing deformation at substantially the same timing with respect to the collision load. Alternatively, the energy absorbing members 11 and 12 may be set to start the energy absorbing deformation at different timings with respect to the collision load. More specifically, when using the buckling energy absorbing material 11 having a large displacement amount up to buckling, the tip of the buckling energy absorbing material 11 is projected forward from the compression energy absorbing material 12, By setting the start timing of the energy absorption deformation by the buckling energy absorber 11 to be earlier than the start timing of the energy absorption deformation by the compression energy absorber 12, substantially the entire energy absorption period of the collision energy absorber 10 is set. The setting is made so that the impact force on the collision energy absorbing device 10 becomes substantially uniform over the period.
[0043]
The number of the buckling energy absorbing members 11 and the compression energy absorbing members 12 and the vertical positional relationship can be set arbitrarily. For example, the buckling energy absorbing members 11 and the compression energy absorbing members 12 may be arranged alternately. Then, a plurality of buckling energy absorbing members 11 may be arranged between the upper and lower compression energy absorbing members 12. More specifically, like a collision energy absorbing device 10B shown in FIG. 7, two buckling energy absorbing members 11 are provided between the compression energy absorbing members 12 and between adjacent buckling energy absorbing members 11. Are provided with compression energy absorbing members 12B having rear connecting members 13 protruding on both upper and lower sides, and three compression energy absorbing members 12 and 12B and two buckling energy absorbing members 11 are provided. When three or more buckling energy absorbers 11 are provided between the upper and lower compression energy absorbers 12, the compression energy absorbers 12B are arranged between the adjacent buckling energy absorbers 11, respectively. The bending energy absorbing material 11 and the compression energy absorbing materials 12, 12B are integrally connected.
[0044]
【The invention's effect】
(Claim 1)
ADVANTAGE OF THE INVENTION According to the collision energy absorption apparatus of the bumper for vehicles which concerns on this invention, with the simple structure of absorbing a collision energy by the combination of a compression energy absorption material and a buckling energy absorption material, the collision energy absorption characteristic is substantially ideal. Can be set in any form. Therefore, by setting the impact force on the collision energy absorbing device to be a target value capable of protecting the pedestrian, a small installation space for the collision energy absorbing device is ensured while sufficiently securing the pedestrian protection performance. Within, the collision energy can be absorbed as efficiently as possible.
[0045]
In addition, in this collision energy absorbing device, the front end portions of both energy absorbing materials can be fixedly held to the bumper fascia by the front fixed holding member, so that the stability of the posture of both energy absorbing materials is enhanced, and It is possible to prevent the posture of the buckling energy absorbing material from being finely changed due to vibration at the time of collision or the like, and to prevent the occurrence of poor compression or buckling due to a change in the posture of the two energy absorbing materials. In particular, since the buckling energy absorbing material greatly changes the form of buckling deformation due to its posture variation, fixing and holding the front end of the buckling energy absorbing material to the bumper fascia maintains the energy absorption efficiency optimally. Preferred above.
[0046]
Furthermore, since the buckling allowable space for allowing buckling deformation is formed on at least one surface side of the buckling energy absorbing material, the buckling deformed buckling energy absorbing material interferes with the compression energy absorbing material. To prevent compression deformation failure of the compression energy absorbing material due to contact with the buckling energy absorbing material, and prevent interference between the buckling energy absorbing materials, so that the buckling does not become bulky in the longitudinal direction of the vehicle body. By buckling the energy absorbing material, the amount of compressive deformation of the compressed energy absorbing material can be set as large as possible.
[0047]
Furthermore, since the buckling energy absorbing material and the compression energy absorbing material are arranged in the vehicle width direction along the front side of the bumper reinforcement, the collision load acting on both energy absorbing materials can be surely secured by the bumper reinforcement. , And even if a collision load acts on an arbitrary position in the vehicle width direction of the bumper fascia, the collision energy can be efficiently absorbed by the two energy absorbing materials.
[0048]
(Claim 2)
Here, if the front fixed holding member is formed integrally with the bumper fascia, it is possible to stabilize the posture of both energy absorbing members while suppressing the manufacturing cost of the collision energy absorbing device.
[0049]
(Claim 3)
As the front fixed holding member, provided on the inner surface of the bumper fascia are rib-shaped front fixed holding members extending to the upper and lower sides of respective distal ends of the buckling energy absorbing material and the compression energy absorbing material, It is possible to provide a front fixed holding member without lowering the moldability of the front part.
[0050]
(Claim 4)
A rear connecting member for connecting the rear part of the buckling energy absorbing material and the rear part of the compressive energy absorbing material is provided. It is preferable to restrict the fluctuation of the energy absorption material so as to more effectively prevent the occurrence of poor compression or poor buckling due to a change in the posture of the two energy absorbing members.
[0051]
(Claim 5)
When a plurality of columnar members are provided at an interval from each other as the rear connection member, the collision of the compression energy absorbing material by providing the rear connection member while further improving the stability of the posture of both energy absorbing materials. It is possible to suppress a decrease in the energy absorbing action as much as possible.
[0052]
(Claim 6)
When the rear connection member is provided integrally with the compression energy absorbing material or the buckling energy absorbing material, the number of components of the collision energy absorbing device can be reduced, the manufacturing cost can be reduced, and the number of assembly steps can be reduced. .
[0053]
(Claim 7)
A rear connecting member is provided on both the upper and lower sides of the buckling energy absorbing material, and the rear connecting member on the upper surface side and the rear connecting member on the lower surface of the buckling energy absorbing material are connected vertically in the vehicle body with the buckling energy absorbing material interposed therebetween. With such a configuration, the stability of the buckling energy absorbing material immediately before or at the time of the collision can be improved, and poor buckling of the buckling energy absorbing material can be prevented.
[0054]
(Claim 8)
When the compression energy absorbing material is formed in a plate shape, it is possible to easily obtain the combined characteristics of the collision energy absorbing characteristics of the two energy absorbing materials, and the design of the collision energy absorbing device is facilitated.
[0055]
(Claim 9)
By providing a plurality of at least one of the compression energy absorbing material and the buckling energy absorbing material, the collision energy absorbing characteristics of the collision energy absorbing device can be set in a well-balanced manner.
[0056]
(Claim 10)
When the buckling energy absorbing material is provided substantially perpendicular to the front surface of the bumper reinforcement, the rearward load on the vehicle body acting on the buckling energy absorbing material at the time of a collision is reliably received by the bumper reinforcement and buckled. The energy absorbing material can be buckled.
[0057]
(Claim 11)
When the buckling energy absorbing material and the compression energy absorbing material are provided substantially in parallel, the amount of deformation of the two energy absorbing materials becomes substantially the same, so that it is easy to obtain the combined characteristics of the collision energy absorbing characteristics of the two energy absorbing materials. And the design of the collision energy absorbing device is facilitated.
[Brief description of the drawings]
FIG. 1 is a plan view of a collision energy absorbing device assembled to a vehicle body front part. FIG. 2 is a front view of a collision energy absorbing device assembled to a vehicle body front part. FIG. FIG. 4 is an exploded perspective view of the collision energy absorbing device. FIG. 5 is a graph showing the relationship between the displacement of the compression energy absorbing material and the buckling energy absorbing material and the impact force. FIG. 6 is a compression energy absorbing device having another configuration. FIG. 7 is a bottom view of the material. FIG. 7 is a longitudinal sectional view of a collision energy absorbing device having another configuration and its vicinity.
DESCRIPTION OF SYMBOLS 1 Body 2 Front side frame 3 Bumper reinforcement 4 Bumper fascia 5 Space 6 Front cross member 7 Lower cushioning material 8 Front bumper 10 Impact energy absorbing device 11 Buckling energy absorbing material 12 Compressed energy absorbing material 13 Rear connecting member 14 Buckling Allowable space 15 Front fixed holding member 10A Collision energy absorber 12A Compressed energy absorber 10B Collision energy absorber 12B Compressed energy absorber

Claims (11)

A collision energy absorbing device for a vehicle bumper assembled in a space between a bumper fascia and a bumper reinforcement,
A compression energy absorbing material arranged in the vehicle width direction along the front side of the bumper reinforcement and absorbing collision energy acting on the bumper fascia by compressive deformation,
The width direction is oriented in the vehicle longitudinal direction so that a buckling allowance space that allows buckling deformation is formed on at least one surface side and is arranged in the vehicle width direction along the front side of the bumper reinforcement. A buckling energy absorber made of a plate-shaped member that is arranged in parallel with the compression energy absorber and absorbs collision energy acting on the bumper fascia by buckling deformation;
A front fixed holding member that is provided in a protruding manner on the inner surface of the bumper fascia and holds front ends of both energy absorbing materials,
A bumper collision energy absorbing device for a vehicle bumper that includes a compression energy absorbing material and a buckling energy absorbing material to absorb collision energy acting on a bumper fascia. The collision energy absorbing device for a vehicle bumper according to claim 1, wherein the front fixed holding member is formed integrally with a bumper fascia. The rib-shaped front fixed holding member which extends to the upper and lower sides of the respective front ends of the buckling energy absorbing material and the compression energy absorbing material is provided on the inner surface of the bumper fascia as the front fixed holding member. 3. The collision energy absorbing device for a vehicle bumper according to 2. 3. The collision energy absorbing device for a vehicle bumper according to claim 1, further comprising a rear connecting member that connects a rear portion of the buckling energy absorbing material and a rear portion of the compression energy absorbing material. 5. The collision energy absorbing device for a vehicle bumper according to claim 4, wherein a plurality of columnar members are provided at an interval from each other as the rear connecting member. The collision energy absorbing device for a vehicle bumper according to claim 4 or 5, wherein the rear connecting member is provided integrally with a compression energy absorbing material or a buckling energy absorbing material. Rear connecting members are provided on both upper and lower sides of the buckling energy absorbing material, and the upper connecting member on the upper surface side and the lower connecting member on the lower surface of the buckling energy absorbing device are connected in the vertical direction of the vehicle body with the buckling energy absorbing material interposed therebetween. The collision energy absorbing device for a vehicle bumper according to any one of claims 4 to 6, wherein the collision energy absorbing device is provided as described above. The collision energy absorbing device for a vehicle bumper according to any one of claims 1 to 7, wherein the compression energy absorbing material is formed in a plate shape. The collision energy absorbing device for a vehicle bumper according to any one of claims 1 to 8, wherein a plurality of at least one of the compression energy absorbing material and the buckling energy absorbing material is provided. The collision energy absorbing device for a vehicle bumper according to any one of claims 1 to 9, wherein the buckling energy absorbing material is provided substantially perpendicular to a front surface of the bumper reinforcement. The collision energy absorbing device for a vehicle bumper according to any one of claims 1 to 10, wherein the buckling energy absorbing material and the compression energy absorbing material are provided substantially in parallel.

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