JP2011245910A - Pedestrian collision detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pedestrian collision detector capable of preventing an increase in mass of a vehicle even if a detection area of collision of a pedestrian is expanded outside a vehicle width direction and improving a pedestrian foot protecting performance.SOLUTION: The detector includes an absorber 20 to be deformed between a bumper cover 16 and a bumper reinforcement 14 when the vehicle collides with a pedestrian and a pressure chamber 18. A change in pressure of the pressure chamber 18 is detected by the pressure sensor, and it is determined whether the vehicle collides with a pedestrian on the basis of the output of the pressure sensor. In the bumper reinforcement 14, corner portions 32 disposed on the outside of the vehicle width from a pair of crash boxes 15 on right and left to which the bumper reinforcement 14 is attached are formed to have rigidity lower than that of a general-purpose portion 30 arranged on the inside of the vehicle width from the corner portions 32.

Description

  The present invention relates to a pedestrian collision detection device for detecting a pedestrian collision with a vehicle.

  A collision detection device for a vehicle shown in Patent Document 1 below is provided on the vehicle front side of a bumper reinforcement, and includes an absorber and a pressure chamber that are compressed and deformed between the bumper cover and the bumper reinforcement when the vehicle collides. ing. A pressure change in the pressure chamber is detected by a pressure sensor, and it is determined whether or not the vehicle has collided with a pedestrian based on the output of the pressure sensor.

  In this vehicle collision detection device, the bumper reinforcement, the absorber, and the pressure chamber are greatly extended outward in the vehicle width direction from the side members. Thereby, the detection area of a pedestrian collision is ensured in the wide range of the vehicle width direction.

JP 2009-18734 A

  However, in the vehicle collision detection apparatus as described above, the bumper reinforcement is greatly extended outward in the vehicle width direction from the side member as described above, so that the mass of the vehicle is increased by the extension part (corner part). End up. If the size of the absorber in the longitudinal direction of the vehicle decreases toward the vehicle width direction outside (vehicle width direction end side) corresponding to the shape of the bumper cover constituting the vehicle design, the compression of the absorber The protection performance of the pedestrian leg due to deformation may be lowered at the vehicle width direction end side.

  In consideration of the above facts, the present invention can suppress the increase in the mass of the vehicle even when the detection area of the pedestrian collision is expanded outward in the vehicle width direction and can improve the pedestrian leg protection performance. It is an object to obtain a person collision detection device.

  A pedestrian collision detection device according to the invention described in claim 1 is a bumper reinforcement attached to vehicle longitudinal direction end portions of a pair of left and right vehicle body skeleton members having a longitudinal direction in the vehicle width direction and extending in the vehicle longitudinal direction. The vehicle width direction is the longitudinal direction, and the vehicle is disposed on the outside in the vehicle front-rear direction with respect to the bumper reinforcement, and when a load is input from the vehicle front-rear direction outside, the bumper reinforcement causes a reaction force from the vehicle front-rear direction inside. The shock absorbing member is deformed while receiving, and the vehicle width direction is the longitudinal direction. The bumper reinforcement is disposed on the same side as the shock absorbing member, and the inside is a pressure chamber. Is input to the bumper reinforcement while it is deformed while receiving a reaction force from the inside in the vehicle longitudinal direction. A collision detector that determines whether the vehicle has collided with a pedestrian based on the output of the pressure detector, a pressure detector that outputs a signal corresponding to a pressure change in the pressure chamber, The bumper reinforcement has a lower rigidity than a general part arranged on the inner side in the vehicle width direction with respect to the corner part. Is formed.

  In the pedestrian collision detection device according to claim 1, when a load is input from the vehicle front-rear direction outside to the buffer member and the chamber member, the buffer member and the chamber member react from the vehicle front-rear direction inner side by bumper reinforcement. Deformed while receiving. Thereby, when the pressure of the pressure chamber in the chamber member changes, the pressure detector outputs a signal corresponding to the pressure change, and the collision determination unit collides with the pedestrian based on the output of the pressure detector. It is determined whether or not.

  Here, in the present invention, the bumper reinforcement has a corner portion disposed on the outer side in the vehicle width direction than the pair of left and right vehicle body skeleton members to which the bumper reinforcement is attached, on the inner side in the vehicle width direction with respect to the corner portion. It is formed with low rigidity compared with the arranged general part. For this reason, when the leg part of a pedestrian collides with the corner part side of bumper reinforcement, the said corner part can absorb the collision energy of a pedestrian leg part by deform | transforming with the load from a buffer member. . Thereby, a pedestrian leg protection performance can be improved. In addition, the weight of the corner can be reduced along with the reduction in rigidity of the corner, so the vehicle mass increases even when the corner is extended outward in the vehicle width direction and the pedestrian collision detection area is expanded. Can be suppressed. The “rigidity” described in claim 1 can be specified by using a sectional second moment, Young's modulus, and the like.

  The pedestrian collision detection device according to claim 2 is the pedestrian collision detection device according to claim 1, wherein the corner portion is formed separately from the general portion and is attached to the general portion. It is characterized by being.

  In the pedestrian collision detection device according to claim 2, since the corner portion of the bumper reinforcement is formed separately from the general portion and attached to the general portion, the corner portion is not related to the material of the general portion. The material can be selected. Thereby, the freedom degree of setting about the mass of a corner part, a deformation load, etc. can be improved.

  The pedestrian collision detection device according to the invention described in claim 3 is the pedestrian collision detection device according to claim 1 or 2, wherein the corner portion is provided between the corner portion and the vehicle body skeleton member. Is characterized in that a compression deformation member is disposed that is compressed and deformed between the two when the vehicle body is deformed to the vehicle body skeleton member side by a load from the outside in the vehicle longitudinal direction.

  In the pedestrian collision detection device according to claim 3, when the corner portion of the bumper reinforcement is deformed to the vehicle body skeleton member side by a load from the vehicle front-rear direction outer side (side where the buffer member and the chamber member are arranged), The compression deformation member disposed therebetween is compressed and deformed. Therefore, collision energy can be absorbed well by this compression deformation. Moreover, since the compression deformation member is supported by the vehicle body skeleton member, the reaction force received by the corner portion from the compression deformation member can be ensured satisfactorily.

  The pedestrian collision detection device according to a fourth aspect of the present invention is the pedestrian collision detection device according to any one of the first to third aspects, wherein the corner portion supports the chamber member. Is formed with a lower rigidity than a portion that supports the buffer member.

  In the pedestrian collision detection device according to claim 4, the corner portion of the bumper reinforcement is formed with a lower rigidity than a portion where the reaction force is applied to the chamber member than a portion where the reaction force is applied to the buffer member. For example, the thickness dimension in the vehicle front-rear direction of the portion that applies the reaction force to the chamber member can be reduced. Thereby, the weight reduction and size reduction of a corner part can be achieved.

  The pedestrian collision detection device according to a fifth aspect of the present invention is the pedestrian collision detection device according to the second aspect, wherein the corner portion has a vehicle rear side portion at an inner end in the vehicle width direction. Is opposed to the vehicle width direction outside, and is compressed and deformed while being supported from the vehicle width direction inside by the vehicle body skeleton member when a load is input from the vehicle front-rear direction outside. Yes.

  In the pedestrian collision detection device according to claim 5, when a collision load is input from the vehicle longitudinal direction outside to the corner portion of the bumper reinforcement, the corner portion is supported from the vehicle width direction inside by the vehicle body skeleton member. Since it is compressed and deformed, the corner portion can be stably compressed and deformed, and the collision energy can be absorbed well. Further, since the corner portion can be made of, for example, a foam material, it is also suitable for reducing the weight of the vehicle.

  The pedestrian collision detection device according to a sixth aspect of the present invention is the pedestrian collision detection device according to the fifth aspect, wherein the corner portion is formed integrally with the buffer member. .

  In the pedestrian collision detection device according to the sixth aspect, since the corner portion of the bumper reinforcement is formed integrally with the buffer member, the manufacturing efficiency of the corner portion and the buffer member can be improved. Further, the work of attaching the corner portion and the buffer member to the vehicle body can be facilitated.

  The pedestrian collision detection device according to a seventh aspect of the present invention is the pedestrian collision detection device according to any one of the first to sixth aspects, wherein the corner portion is made of a material having different rigidity. It is characterized by being laminated in the direction.

  In the pedestrian collision detection device according to the seventh aspect of the invention, the corner portions of the bumper reinforcement are formed by laminating materials having different rigidity in the vehicle longitudinal direction. For this reason, for example, the reaction force applied to the buffer member and the chamber member from the corner portion can be quickly started up with a highly rigid material. Further, after the material having high rigidity enters the plastic deformation region, the reaction force can be controlled by the deformation load of the material having low rigidity. Therefore, the degree of freedom in setting the reaction force can be improved.

  As described above, the pedestrian collision detection device according to claim 1 can suppress an increase in the mass of the vehicle even when the detection area of the pedestrian collision is expanded outward in the vehicle width direction, and the pedestrian leg portion. Protection performance can be improved.

  In the pedestrian collision detection device according to the second aspect, it is possible to improve the degree of freedom in setting the corner portion mass, deformation load, and the like.

  In the pedestrian collision detection device according to the third aspect, the collision energy can be satisfactorily absorbed by the compression deformation of the compression deformation member, and the reaction force received by the corner portion from the compression deformation member can be sufficiently ensured. .

  In the pedestrian collision detection device according to the fourth aspect, the corner portion can be reduced in weight and size.

  In the pedestrian collision detection device according to the fifth aspect, the corner portion can be stably compressed and deformed, and the collision energy can be favorably absorbed.

  In the pedestrian collision detection device according to the sixth aspect, the manufacturing efficiency of the corner portion and the buffer member can be improved, and the corner portion and the buffer member can be easily attached to the vehicle body.

  In the pedestrian collision detection device according to the seventh aspect, the degree of freedom in setting the reaction force that the corner portion applies to the buffer member and the chamber member can be improved.

It is a cross-sectional view which shows the structure of the front bumper to which the collision body discrimination | determination system which concerns on 1st Embodiment of this invention was applied. It is an expanded sectional view which shows the cut surface along the F2-F2 line | wire of FIG. It is a disassembled perspective view which shows the partial structure of the bumper reinforcement which comprises the front bumper shown by FIG. It is a cross-sectional view which shows the structure of the front bumper which concerns on a comparative example. It is a diagram which shows the collision simulation result to the corner part of the front bumper shown by FIG. 4, (A) is a simulation result in case a collision body is a small pedestrian, (B) is a collision. It is a simulation result in case a body is a pedestrian with a big physique. It is a diagram for demonstrating the relationship between the collision load added to the corner part of the bumper reinforcement shown by FIG. 1, and time. It is a top view which shows the partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 2nd Embodiment of this invention. It is a diagram for demonstrating the relationship between the collision load added to the corner part of the bumper reinforcement shown by FIG. 7, and time. It is a top view which shows the partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 3rd Embodiment of this invention. The partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 4th Embodiment of this invention is shown, (A) is a front view, (B) is a top view. It is a top view which shows the partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 5th Embodiment of this invention. It is a top view which shows the partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 6th Embodiment of this invention. It is a top view which shows the partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 7th Embodiment of this invention. The partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 8th Embodiment of this invention is shown, (A) is a front view, (B) is a top view. It is a top view which shows the partial structure of the bumper reinforcement which is a structural member of the collision body discrimination | determination system which concerns on 9th Embodiment of this invention. It is a top view which shows the structure of the front bumper to which the collision body discrimination | determination system which concerns on 10th Embodiment of this invention was applied. It is an expanded sectional view which shows the cut surface along the F17-F17 line | wire of FIG. It is a longitudinal cross-section of the vehicle width direction end side part of the front bumper to which the collision body discrimination | determination system which concerns on 11th Embodiment of this invention was applied.

<First Embodiment>
Hereinafter, the collision object discrimination system 10 as the pedestrian collision detection device according to the first embodiment of the present invention will be described with reference to FIGS. In these drawings, an arrow FR appropriately shown indicates the vehicle front side, an arrow UP indicates the vehicle upper side, and an arrow IN indicates the vehicle width direction inner side.

  As shown in FIGS. 1 and 2, the collision object discrimination system 10 is applied to a front bumper 12 disposed at the front end of the automobile, and identifies a collision object to the front bumper 12.

  The front bumper 12 includes a bumper reinforcement 14 as a bumper skeleton member. The bumper reinforcement 14 is configured as a skeleton member arranged with the vehicle width direction as a longitudinal direction. The bumper reinforcement 14 is attached to the front ends of a pair of left and right front side members 17 via a pair of left and right crash boxes 15. The crash box 15 and the front side member 17 constitute a vehicle body skeleton member extending in the vehicle front-rear direction. The crash box 15 is set to have a lower proof strength against the axial compression load than the front side member 17. Thereby, at the time of a collision with the front bumper 12, the crash box 15 is configured to be subjected to axial compression deformation between the bumper reinforcement 14 and the front side member 17, thereby absorbing the collision energy.

  The front bumper 12 includes a bumper cover 16 that covers the bumper reinforcement 14 from the outside in the vehicle front-rear direction (here, the front side). The bumper cover 16 is made of a resin material or the like, and is fixedly supported to the vehicle body at a portion (not shown) so that a space is formed between the bumper cover 16 and the bumper reinforcement 14. A chamber member 18 and an absorber 20 as a buffer member are disposed in a space between the bumper reinforcement 14 and the bumper cover 16 in the front bumper 12. The chamber member 18 is configured as a hollow structure that is long in the vehicle width direction, and is fixedly attached to the upper portion of the front surface of the bumper reinforcement 14. The chamber member 18 has substantially the same positions at both ends in the longitudinal direction as the positions of both ends of the bumper reinforcement 14.

  Further, the chamber member 18 has rigidity capable of maintaining its shape (cross-sectional shape shown in FIG. 2), and has a communication hole communicating with the atmosphere at a position not shown. Therefore, normally (statically), the internal pressure of the pressure chamber 24 which is the internal space of the chamber member 18 is set to atmospheric pressure. The chamber member 18 is compressed and deformed while receiving a reaction force from the rear side of the vehicle by the bumper reinforcement 14 when receiving a compressive load from the front side of the vehicle. In this case, the chamber member 18 is crushed while allowing air to escape from the communication hole, and the volume of the pressure chamber 24 is reduced.

  Furthermore, the collision object discrimination system 10 includes a pressure sensor 22 as a pressure detector that outputs a signal corresponding to the pressure in the pressure chamber 24. The pressure sensor 22 is configured to output a signal corresponding to the pressure in the pressure chamber 24 to the ECU 26 described later. The pressure sensor 22 is configured to output a signal corresponding to the atmospheric pressure in addition to a signal corresponding to the pressure in the pressure chamber 24 to the ECU 26.

  On the other hand, the absorber 20 is formed in a long shape by, for example, polypropylene foam as a foam material, and is arranged with the vehicle width direction as a longitudinal direction. The absorber 20 is fixedly attached to the lower front portion of the bumper reinforcement 14 independently of the chamber member 18, and includes an absorber main body 20 </ b> A disposed in parallel below the chamber member 18, and the front of the chamber member 18. And a spacer portion 20 </ b> B disposed on the surface. The absorber main body 20 </ b> A has positions at both ends in the longitudinal direction substantially coincident with positions at both ends of the bumper reinforcement 14, and a rear end surface is fixed (contacted) to the front surface of the bumper reinforcement 14. Further, the absorber main body 20A has a dimension along the vehicle front-rear direction that is larger on the vehicle width direction center side than the vehicle width direction end side.

  When the collision load is input from the vehicle front side, the above-described absorber body 20A is compressed and deformed while receiving the reaction force from the vehicle rear side by the bumper reinforcement 14 to absorb the collision energy. On the other hand, the spacer portion 20B of the absorber 20 is provided only on the center side in the vehicle width direction of the absorber main body 20A, and is configured to mainly transmit the collision load to the chamber member 18. Thereby, the chamber member 18 is compressed and deformed so that the volume of the pressure chamber 24 is reduced as the absorber body 20A is compressed and deformed.

  Moreover, this collision object discrimination system 10 is provided with ECU26 as a collision determination part. The ECU 26 is electrically connected to the pressure sensor 22 and detects a pressure change ΔP (generated pressure) in the pressure chamber 24 based on a signal from the pressure sensor 22. Further, the ECU 26 is electrically connected to a collision speed sensor 28 that outputs a signal corresponding to the collision speed with the collision body, and the collision speed V between the vehicle and the collision body based on the signal from the collision speed sensor 28. Is detected. The collision speed sensor 28 can be configured using, for example, a vehicle speed sensor. Further, as the output of the collision speed sensor 28, a time-differentiated output of the output of a distance sensor such as a millimeter wave radar may be used.

The ECU 26 integrates the pressure change ΔP described above with a predetermined determination time t _j and determines whether or not a value D obtained by dividing the integrated value by the collision speed V exceeds a preset (stored) threshold value T. to decide. In this case, the above-described determination time t _j is set based on the time from when the pedestrian's leg collides with the front bumper 12 until the pedestrian's head contacts the engine hood. By comparing the division value D and the threshold value T, it is determined whether the collision body is a pedestrian or a road fixed body such as a roadside marker pole.

  That is, in the case of a collision with the roadside marker pole, the front bumper 12 (automobile) is relatively displaced in the direction away from the roadside marker pole by the reaction force after the collision, so the duration of the pressure change ΔP is shortened. On the other hand, in the case of a collision with a pedestrian, since the pedestrian is relatively displaced so as to fall down to the engine hood side, the input duration to the front bumper 12 becomes longer, and the time integral value of the pressure change ΔP is the value of the roadside marker pole. It becomes a high value compared with the case. Further, by dividing the time integral value of the pressure change ΔP by the collision speed V, the influence due to the difference in the peak value of the generated pressure due to the collision speed V can be eliminated. Thus, the ECU 26 is configured to determine that the collision object is a pedestrian when the division value D exceeds the threshold value T.

  When the ECU 26 determines that the collision body is a pedestrian, for example, a signal corresponding to the collision body being a pedestrian, for a pedestrian safety ECU for controlling a pedestrian safety device. Is output. Note that the ECU 26 can also serve as a pedestrian safety ECU.

  Next, the main part of this embodiment will be described.

  As shown in FIG. 1, in the present embodiment, the bumper reinforcement 14 described above is configured by a general portion 30 and corner portions 32 disposed on both sides of the general portion 30 in the vehicle width direction. The general part 30 is formed in a long shape with a highly rigid material such as a metal material (for example, iron or aluminum), and is arranged with the vehicle width direction as the longitudinal direction. The general portion 30 is attached to the crash boxes 15 in a state of being spanned between the front ends of the pair of left and right crash boxes 15. The end portion in the longitudinal direction of the general portion 30 protrudes slightly outward in the vehicle width direction from the crash box 15 and is slightly bent toward the vehicle rear side.

  As shown in FIGS. 2 and 3, the general portion 30 has a hollow rectangular cross section (shape of cross section), and a pair of upper and lower ribs are provided inside. The general portion 30 has the same cross-sectional shape throughout the longitudinal direction, and three rectangular openings 30A (see FIG. 3) arranged vertically are formed on the end surface of the general portion 30 in the longitudinal direction. Is formed.

  On the other hand, the corner portion 32 constitutes a portion on the outer side in the vehicle width direction with respect to the crash box 15 in the bumper reinforcement 14. These corner portions 32 are formed in a long shape with a material having a lower Young's modulus than the material of the general portion 30 (for example, rubber, resin, etc.), and are formed with lower rigidity than the general portion 30. ing. At one end in the longitudinal direction of the corner portion 32 (inner end in the vehicle width direction), a press-fit portion 32A that is press-fitted into the inside of the general portion 30 through the three openings 30A is provided. Thereby, the corner part 32 is attached to the longitudinal direction end part of the general part 30. The corner portion 32 is disposed so as to be inclined with respect to the vehicle width direction, and retracts toward the vehicle rear side as it goes toward the vehicle width direction outer side (the other end in the longitudinal direction). This corresponds to the shape of the bumper cover 16 constituting the design of the vehicle, and the chamber member 18 and the absorber 20 described above are inclined so that both ends in the vehicle width direction are along the corner portion 32. Thereby, the chamber member 18 and the absorber 20 are in contact with the bumper reinforcement 14 in the entire region in the longitudinal direction.

  Next, the operation and effect of the first embodiment will be described.

  In the collision object discriminating system 10 configured as described above, when a collision object collides with the front bumper 12 from the front side of the vehicle, a collision load acts on the collision portion in the rearward direction of the vehicle. For this reason, the absorber 20 is compressed and deformed by an amount corresponding to the collision load while receiving a reaction force from the rear side of the vehicle by the bumper reinforcement 14. Thereby, the collision energy of a collision body is absorbed. On the other hand, the chamber member 18 is crushed in the vehicle front-rear direction with almost no reaction force while receiving the reaction force from the rear side of the vehicle by the bumper reinforcement 14. As a result, the pressure in the pressure chamber 24 changes.

A signal corresponding to the pressure change ΔP of the pressure chamber 24 is input from the pressure sensor 22 to the ECU 26, and a signal corresponding to the collision speed V is input from the collision speed sensor 28. The ECU 26 integrates the pressure change ΔP with a predetermined determination time t _j and determines that the collision object is a pedestrian when a value D obtained by dividing the integrated value by the collision speed V exceeds a predetermined threshold T. To do.

  Here, in the collision object discrimination system 10, the corner portion 32 of the bumper reinforcement 14 is formed with a lower rigidity than the general portion 30 on the inner side in the vehicle width direction with respect to the corner portion 32. For this reason, when the leg part of a pedestrian collides with the corner part 32 side of the bumper reinforcement 14 (see arrow C in FIG. 1), the corner part 32 is deformed to the rear side of the vehicle by the load from the absorber 20. Thus, the collision energy of the pedestrian leg can be absorbed. Thereby, the pedestrian leg part protection performance in the vehicle width direction end side of the front bumper 12 can be improved.

  That is, since the size of the absorber 20 in the vehicle front-rear direction is set smaller on the vehicle width direction end side of the front bumper 12 than on the vehicle width direction center side, the amount of impact energy absorbed by the compression deformation of the absorber 20 is reduced. Although it is relatively low, in this embodiment, the amount of impact energy absorbed can be increased by deforming the corner portion 32.

Further, in the present embodiment, since the corner portion 32 is formed of a material having a low Young's modulus than the general portion 30, the corner portion 32 is broken in the middle of the determination time t _j (broken) can be prevented. Thereby, sensing performance can be improved. Hereinafter, a specific description will be given based on FIGS.

  FIG. 4 is a schematic plan view showing a conventional front bumper 200 according to a comparative example. In the front bumper 200, the general portion 204 and the corner portion 206 of the bumper reinforcement 202 are integrally formed of a metal material or the like, but the other configuration is the same as that of the present embodiment (see FIG. 4). Then, for convenience of explanation, the same reference numerals are given to the same configurations as in the present embodiment).

  5 (A) and 5 (B) are diagrams showing simulation results when a collision object collides with the corner portion 206 of the front bumper 200 according to the comparative example. 5A and 5B, the relationship between the pressure change ΔP of the pressure chamber 24 and the time t is shown by a solid line, and the relationship between the collision load F applied to the corner portion 206 and the time t is shown. It is indicated by a two-dot chain line. 5A is a simulation result when the collision body is a pedestrian (child) having a small physique, and FIG. 5B is a case where the collision body is a pedestrian (adult) having a large physique. This is a simulation result. Further, the hatched area in FIGS. 5A and 5B is an area necessary for the ECU to determine that the collision body is a pedestrian (ON determination) (time integration of the pressure change ΔP). Value).

Here, as shown in FIGS. 5 (A) and 5 (B), the maximum value of the pressure change ΔP in the pressure chamber 24 is almost the same between the child and the adult. This is because the chamber member 18 is almost crushed at the collision site regardless of whether the collision body is a child or an adult. On the other hand, when the collision object is an adult, the collision load F applied to the corner portion 206 greatly increases at the initial stage of the collision (see the maximum load F _max shown in FIG. 5B).

  For this reason, in the bumper reinforcement 202 (comparative example) in which the corner portion 206 is formed of a metal material or the like in the same manner as the general portion 204, the rigidity of the corner portion 206 is lowered corresponding to the leg protection performance for children. In this case, when an adult collides with the corner portion 206 of the bumper reinforcement 202, the corner portion 206 cannot withstand the maximum load P and breaks. In this case, the pressure change ΔP of the pressure chamber 22 cannot be maintained, and the ECU cannot determine the collision of the pedestrian (the ECU erroneously determines that the collision is with the roadside marker pole or the like). End up).

In this regard, in the present embodiment, the corner portion 32 of the bumper reinforcement 14 is formed of a material having a Young's modulus lower than that of the general portion 30, so that the collision load F applied to the corner portion 32 is thicker in FIG. 6. It gradually increases (linearly) as indicated by the solid line. Thus, it is possible to prevent the corner portion 32 is broken in the middle of the determination time t _j. In addition, the corner portion 32 continues to apply a reaction force to the chamber member 18 and the absorber 20, whereby the pressure change ΔP in the pressure chamber 24 can be maintained. Thereby, since the erroneous determination of the ECU 26 as described above can be prevented, the sensing performance can be improved.

  In addition, in this embodiment, the corner portion 32 can be reduced in weight as the corner portion 32 is reduced in rigidity. That is, since the corner portion 32 can be formed lightly with a rubber material, a resin material, or the like, even if the corner portion 32 is extended outward in the vehicle width direction to expand the detection area of the pedestrian collision, the mass of the vehicle Can be prevented from increasing.

  Furthermore, in the present embodiment, since the corner portion 32 is formed with low rigidity, when the corner portion 32 is deformed to the vehicle rear side (not shown) and hits a front tire (not shown) due to a light collision with the corner portion 32. However, it can prevent the front tire from being damaged. In addition, since the corner portion 32 hits the front tire, it is possible to prevent the steering operation from becoming impossible or difficult, and therefore, it is preferable that the vehicle does not prevent the vehicle from traveling after a light collision.

  Next, another embodiment of the present invention will be described. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol as the said 1st Embodiment is provided, and the description is abbreviate | omitted.

<Second Embodiment>
FIG. 7 is a plan view showing a partial configuration of a bumper reinforcement 40 that is a constituent member of a collision object discrimination system (pedestrian collision detection device) according to a second embodiment of the present invention.

  This embodiment has basically the same configuration as the first embodiment, and the bumper reinforcement 40 includes a general portion 30 and corner portions 42 attached to both ends of the general portion 30 in the vehicle width direction. It is constituted by. The corner portion 42 is formed with lower rigidity than the general portion 30 as in the first embodiment.

  However, the corner portion 42 is formed by laminating materials having different rigidity in two layers in the vehicle front-rear direction, and the front portion 44 disposed on the vehicle front side is disposed on the vehicle rear side. Further, the rear portion 46 is made of a material having higher rigidity. As a material of these front part 44 and rear part 46, a resin material or a rubber material can be applied.

  Also in this embodiment, since the corner part 42 is formed with low rigidity as compared with the general part 30, the same operational effects as the first embodiment can be obtained. However, in this embodiment, since the front portion 44 of the corner portion 42 is made of a material having higher rigidity than the rear portion 46 as described above, when a collision body collides with the corner portion 42 side from the front side of the vehicle. The collision load F applied to the corner portion 42 rises linearly at an early stage due to the rigidity of the front portion 44 (see FIG. 8). Thereby, the internal pressure of the pressure chamber 24 (illustration omitted in FIG. 7) of the chamber member 18 can be raised at an early stage. Then, after the front portion 44 enters the plastic deformation region (after t1 in FIG. 8), the rear portion 46 is bent and deformed, and the front portion 44 is supported by the bending rigidity, whereby a collision load F applied to the corner portion 42 is obtained. Can be made to be non-linear and substantially horizontal. Thereby, the pressure change ΔP of the pressure chamber 24 can be maintained. Therefore, also in this embodiment, the sensing performance for pedestrian discrimination can be improved.

<Third Embodiment>
FIG. 9 is a plan view showing a partial configuration of a bumper reinforcement 50 that is a component of a collision object discrimination system (pedestrian collision detection device) according to a third embodiment of the present invention. This embodiment has basically the same configuration as the second embodiment, and the corner portion 52 of the bumper reinforcement 50 is formed by laminating materials having different rigidity in two layers in the vehicle longitudinal direction. The front portion 54 arranged on the vehicle front side is made of a material having higher rigidity than the rear portion 56 arranged on the vehicle rear side.

  However, in this embodiment, the front portion 54 of the corner portion 52 is formed integrally with the general portion 30. In other words, the general portion 30 of the bumper reinforcement 50 is extended outward in the vehicle width direction, the rear side of the extended portion is removed by, for example, cutting or the like, and the rear portion 56 that is a separate member is attached to the removed portion. It has become. This embodiment also has basically the same operational effects as the second embodiment.

<Fourth Embodiment>
FIG. 10A is a front view showing a partial configuration of a bumper reinforcement 60 that is a constituent member of a collision object discrimination system (pedestrian collision detection device) according to a fourth embodiment of the present invention. ing. FIG. 10B shows a partial configuration of the bumper reinforcement 60 in a plan view. This embodiment has basically the same configuration as the first embodiment. However, in the bumper reinforcement 60 according to this embodiment, the general portion 30 and the corner portion 62 are integrally formed of a highly rigid material such as a metal material, and the corner portion 62 is connected to the vehicle in the vehicle. A plurality of holes 64 penetrating in the front-rear direction are formed. Thereby, the corner part 62 is formed in low rigidity compared with the general part 30 (the corner part 62 is weakened). The method for weakening the corner portion 62 is not limited to the hole 62, and other methods such as reduction of the plate thickness may be employed.

  Furthermore, in this embodiment, a compression deformation member 66 formed of a foam material similar to the absorber 20 is disposed between the corner portion 62 and the crash box 15. The compression deformation member 66 is formed in a substantially trapezoidal shape when viewed from the vehicle vertical direction, and the dimension in the vehicle front-rear direction decreases toward the outer side in the vehicle width direction. The compression deformation member 66 has a surface facing the front side of the vehicle in contact with the rear surface of the corner portion 62, and a surface facing inward in the vehicle width direction contacts the side surface of the crash box 15 (surface in the vehicle width direction outer side). For example, it is joined to the corner 62 and the crash box 15 by means such as adhesion.

  In this embodiment, when a collision object collides with the corner portion 42 from the front side of the vehicle, the collision load F applied to the corner portion 42 is early due to the rigidity of the corner portion 62 formed integrally with the general portion 30. Stands up linearly. Thereby, the internal pressure of the pressure chamber 24 of the chamber member 18 (not shown) can be raised at an early stage. After the corner portion 62 enters the plastic deformation region, the compressive deformation member 66 applies a reaction force to the corner portion 62 while being compressed and deformed between the corner portion 62 and the crash box 15. As a result, the collision load F applied to the corner portion 62 can be changed in a non-linear and substantially horizontal manner, and the pressure change ΔP in the pressure chamber 24 can be maintained. Therefore, also in this embodiment, the sensing performance for pedestrian discrimination can be improved. In addition, in this embodiment, since the compression deformation member 66 is supported by the crash box 15, the reaction force that the corner portion 62 receives from the compression deformation member 66 can be stably secured.

<Fifth Embodiment>
FIG. 11 is a plan view showing a partial configuration of a bumper reinforcement 70 that is a constituent member of a collision object discrimination system (pedestrian collision detection device) according to a fifth embodiment of the present invention. This embodiment has basically the same configuration as that of the first embodiment, and the bumper reinforcement 70 includes a general portion 30 and corner portions 72 attached to both ends in the longitudinal direction of the general portion 30. It is configured. The corner portion 72 is formed of the same foam material as that of the absorber 20, and is formed with lower rigidity than the general portion 30. Further, the corner portion 72 is formed in a substantially trapezoidal shape when viewed from the vehicle vertical direction, and the dimension in the vehicle front-rear direction decreases toward the outside in the vehicle width direction.

  An illustration is shown in which the corner portion 72 is press-fitted into the general portion 30 through three openings 30A (see FIG. 3) formed in the end surface in the longitudinal direction of the general portion 30 on the front side of the vehicle width direction inner end portion. A press-fitting part is provided, and the corner part 72 is attached to the general part 30 by this. Further, the rear side of the corner 72 in the vehicle width direction inner end is disposed in contact with the side surface (end surface in the vehicle width direction) of the crash box 15. That is, in this embodiment, the corner portion 72 is configured to be integrally formed with the compression deformation member 66 according to the fourth embodiment.

  Also in this embodiment, since the corner part 72 is formed with a lower rigidity than the general part 30 by the foam material, the same operational effects as the first embodiment are obtained. In addition, when the corner portion 72 is compressed and deformed by the collision load, the corner portion 72 is supported by the crash box 15, and thus the reaction force of the corner portion 72 can be stably secured. Furthermore, since the corner portion 72 is formed of a foam material, the mass of the vehicle can be significantly reduced.

<Sixth Embodiment>
FIG. 12 is a plan view showing a partial configuration of a bumper reinforcement 80 that is a constituent member of a collision object discrimination system (pedestrian collision detection device) according to a sixth embodiment of the present invention. This embodiment has basically the same configuration as the fifth embodiment. However, in this embodiment, the corner part 72 is formed integrally with the absorber 20, and the corner part 72 is attached to the general part 30 of the bumper reinforcement 80 by attaching the absorber 20 to the general part 30 of the bumper reinforcement 80. It is supported by.

  Also in this embodiment, the corner portion 72 provides the same operational effects as the fifth embodiment. Moreover, since the corner portion 72 is formed integrally with the absorber 20, the configuration can be made extremely simple. Moreover, since the corner part 72 and the absorber 20 can be attached to the general part 30 by one attachment operation | work, the efficiency of attachment operation | work can be improved.

<Seventh Embodiment>
FIG. 13 is a plan view showing a partial configuration of a bumper reinforcement 90 that is a constituent member of a collision object discrimination system (pedestrian collision detection device) according to a seventh embodiment of the present invention. This embodiment has basically the same configuration as that of the fifth embodiment, and includes a corner portion 92 that has basically the same configuration as the corner portion 72 according to the fifth embodiment. However, the corner portion 92 is formed of two types of foam materials having different rigidity (hardness), and the front portion 94 disposed on the vehicle front side is more rigid than the rear portion 96 disposed on the vehicle rear side. Is made of high material. The front portion 94 extends on an extension of the general portion 30. The rear portion 96 is formed in a triangular shape when viewed from the vehicle vertical direction, and is disposed so as to fill a gap between the front portion 94 and the crash box 15.

  Also in this embodiment, since the configuration is basically the same as that of the fifth embodiment, the same effects as the fifth embodiment are obtained. In addition, in this embodiment, when a load is input to the corner portion 92 from the front side of the vehicle, the front portion 94 formed of a hard foam material is in a bending deformation mode, thereby forming the soft foam material. The rear portion 96 is compressed and deformed by the front portion 94. That is, since the soft rear portion 96 is pushed by the front portion 94 and is compressed and deformed as a whole, the compression load absorption of the soft rear portion 96 can be used efficiently.

<Eighth Embodiment>
FIG. 14 (A) is a front view showing a partial configuration of a bumper reinforcement 100 that is a component of a collision object discrimination system (pedestrian collision detection device) according to an eighth embodiment of the present invention. ing. FIG. 14B shows a partial configuration of the bumper reinforcement 100 in a plan view. The bumper reinforcement 100 has basically the same configuration as the bumper reinforcement 14 according to the first embodiment, but the mounting structure of the corner portion 32 to the general portion 30 is different from the first embodiment. Is different. In this embodiment, a plate-shaped corner portion attachment piece 30 </ b> B is provided at the outer end portion of the general portion 30 in the vehicle width direction. The corner portion attachment piece 30 </ b> B extends from the front edge of the vehicle width direction outer end portion of the general portion 30 toward the vehicle width direction outer side.

  Further, in this embodiment, the press-fit portion 32A of the corner portion 32 is omitted, and the inner end portion of the corner portion 32 in the vehicle width direction is overlapped and arranged on the rear side of the corner portion attachment piece 30B. The overlapping portion of the corner portion 32 is provided with a pair of upper and lower protrusions 32B (claws) protruding toward the vehicle front side (corner portion attachment piece 30B side). These protrusions 32B are formed in a columnar shape having a short axial dimension, and are fitted into a pair of upper and lower circular fitting holes 30C formed in the corner portion attachment piece 30B.

  In this embodiment, when a collision load is input to the corner portion 32 from the front side of the vehicle (see arrow C in FIG. 14B), the corner portion 32 rotates about the protrusion 32B toward the rear side of the vehicle. Therefore, the protrusion 32B is caught by the hole edge portion of the fitting hole 30C, and the inadvertent withdrawal of the protrusion 32B from the fitting hole 30C is prevented or suppressed. Thereby, inadvertent drop-off of the corner part 32 from the general part 30 can be prevented or suppressed. In addition, the corner portion 32 can be attached to the general portion 30 simply by fitting the protrusion 32B into the fitting hole 30C, so that the operation of attaching the corner portion to the general portion 30 can be facilitated. The shapes of the protrusions and the fitting holes can be changed as appropriate.

<Ninth Embodiment>
FIG. 15 is a plan view showing a partial configuration of a bumper reinforcement 110 that is a component of a collision object discrimination system (pedestrian collision detection device) according to a ninth embodiment of the present invention. The bumper reinforcement 110 has basically the same configuration as the bumper reinforcement 14 according to the first embodiment. In this embodiment, the outer end surface of the general portion 30 in the vehicle width direction is in the vehicle front-rear direction. The body of the corner portion 32 is slightly inclined with respect to the press-fit portion 32A.

  In this embodiment, when a collision load is input to the corner portion 32 from the front side of the vehicle (see arrow C in FIG. 15), it is difficult to generate a component force in a direction in which the press-fit portion 32A comes out of the general portion 30. Inadvertent drop-off of the corner portion 32 from the general portion 30 can be prevented or suppressed.

<Tenth Embodiment>
FIG. 16 shows a front bumper 120 constituting a collision object discrimination system (pedestrian collision detection device) according to the tenth embodiment of the present invention in a cross-sectional view. FIG. 17 is an enlarged vertical sectional view showing a cut surface along the line F17-F17 in FIG. This embodiment is basically configured similarly to the first embodiment, but in the bumper reinforcement 122 of the front bumper 120 according to this embodiment, the general portion 30 and the corner portion 124 are made of a metal material. It is integrally formed. The general part 30 has the same configuration as that of the general part 30 according to the first embodiment, and has a cross-sectional shape shown in FIG. On the other hand, as shown in FIG. 17, the corner portion 124 is formed with a plate-like upper portion 126 that supports the pressure chamber 18 from the vehicle rear side, and a lower portion 128 that supports the absorber body 20A from the vehicle rear side. It is formed in a rectangular hollow shape. In other words, in this embodiment, the corner portion 124 is made lower in rigidity than the general portion 30 by forming the upper portion 126 of the corner portion 124 into a thin plate shape by cutting or the like.

  In this embodiment, when a collision load is input from the vehicle front side to the corner portion 124 side of the bumper reinforcement 14 (see arrow C in FIG. 16), the absorber 20 is moved to the vehicle by the rigidity of the lower portion 128 of the corner portion 124. It can be supported from the rear side. That is, since the reaction force from the collision body is supported by the absorber 20, only the deformation load of the lower portion 128 that supports the absorber 20 is controlled, and the upper portion 126 that supports the chamber member 18 is the minimum necessary for crushing the chamber member 18. Limited rigidity (thickness). Accordingly, the weight of the corner portion 124 can be reduced, the size of the corner portion 124 can be reduced, and the installation space of the corner portion 124 can be reduced.

<Eleventh embodiment>
FIG. 18 is a longitudinal sectional view showing an outer portion in the vehicle width direction of the front bumper 130 constituting the collision object discrimination system (pedestrian collision detection device) according to the eleventh embodiment of the present invention. This embodiment is configured based on the same concept as the tenth embodiment, but the bumper reinforcement 132 is a plate-shaped main body 134 and a reinforcing portion attached to the vehicle rear side of the main body 134. 136. The main body part 134 is formed in a long plate shape with a metal material or the like, and extends over substantially the entire region in the vehicle width direction in a state where the longitudinal direction is along the vehicle width direction and the plate thickness direction is along the vehicle front-rear direction. It is extended.

  On the other hand, the reinforcing portion 136 is formed in a long plate shape by, for example, a foam material, and is attached to the rear surface of the main body portion 134 in a laminated state. The height of the reinforcing portion 136 is set to be equal to that of the main body portion 134 at the vehicle width direction center side (general portion) of the bumper reinforcement 132 (see the two-dot chain line in FIG. 18). On the other hand, in the corner portion 138 disposed outside the crash box 15 (not shown in FIG. 18) in the vehicle width direction, the upper side is omitted as shown by a solid line in FIG. Thus, the corner portion 138 is formed such that the upper portion that supports the chamber member 18 from the vehicle rear side is less rigid than the lower portion that supports the absorber body 20A from the vehicle rear side. Therefore, this embodiment also has basically the same effects as the tenth embodiment.

  In the first embodiment, the general portion 30 of the bumper reinforcement 14 is formed of a metal material or the like, and the corner portions 32, 42, 52, 62, 72, and 92 are formed of a rubber material, a resin material, a foam material, or the like. However, the invention according to claims 1 to 6 is not limited thereto, and the materials of the general part and the corner part can be changed as appropriate.

  In addition, the present invention can be implemented with various modifications without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiments.

10 Collision detection system (pedestrian collision detection device)
14 Bumper reinforcement 15 Crash box (body frame)
17 Front side member (body frame member)
18 Chamber member 20 Absorber (buffer member)
22 Pressure sensor (pressure detector)
24 pressure chamber 26 ECU (collision judgment unit)
30 general part 32 corner part 40 bumper reinforcement 42 corner part 50 bumper reinforcement 52 corner part 60 bumper reinforcement 62 corner part 70 bumper reinforcement 72 corner part 80 bumper reinforcement 90 bumper reinforcement 92 corner part 100 bumper reinforcement 110 Bumper reinforcement 122 Bumper reinforcement 124 Corner part 132 Bumper reinforcement 138 Corner part

Claims (7)

A bumper reinforcement attached to the vehicle longitudinal direction ends of a pair of left and right vehicle body skeleton members having a longitudinal direction in the vehicle width direction and extending in the longitudinal direction of the vehicle;
The vehicle width direction is the longitudinal direction, and the vehicle is disposed on the outside in the vehicle front-rear direction with respect to the bumper reinforcement. A cushioning member that is deformed while receiving,
The vehicle width direction is the longitudinal direction, the bumper reinforcement is disposed on the same side as the buffer member, the inside is a pressure chamber, and when a load is input from the vehicle front-rear direction outer side, the bumper reinforcement A chamber member that is deformed while receiving a reaction force from the inside in the vehicle longitudinal direction by the
A pressure detector that outputs a signal corresponding to a pressure change in the pressure chamber;
A collision determination unit that determines whether the vehicle has collided with a pedestrian based on the output of the pressure detector;
With
The bumper reinforcement is formed such that a corner portion arranged on the outer side in the vehicle width direction than the pair of vehicle body skeleton members has a lower rigidity than a general portion arranged on the inner side in the vehicle width direction with respect to the corner portion. Pedestrian collision detection device.   The pedestrian collision detection device according to claim 1, wherein the corner portion is formed separately from the general portion and attached to the general portion.   A compression deformation member is disposed between the corner portion and the vehicle body skeleton member. The compression deformation member is compressed and deformed between the corner portion and the vehicle body skeleton member when the corner portion is deformed toward the vehicle body skeleton member by a load from the outside in the vehicle front-rear direction. The pedestrian collision detection device according to claim 1 or 2, wherein the pedestrian collision detection device is provided.   The corner portion is formed such that a portion for applying a reaction force to the chamber member has a lower rigidity than a portion for applying a reaction force to the buffer member. The pedestrian collision detection device according to item 1.   The corner portion is arranged such that the vehicle rear side portion of the inner end portion in the vehicle width direction is opposed to the vehicle body skeleton member from the outer side in the vehicle width direction, and when a load is input from the outer side in the vehicle front-rear direction. The pedestrian collision detection device according to claim 2, wherein the pedestrian collision detection device is compressed and deformed while being supported from the vehicle width direction inner side by the vehicle body skeleton member.   The pedestrian collision detection device according to claim 5, wherein the corner portion is formed integrally with the buffer member.   The pedestrian collision detection device according to any one of claims 1 to 5, wherein the corner portion is formed by laminating materials having different rigidity in a vehicle longitudinal direction.

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