JP2020082931A - Pedestrian protection device for vehicle - Google Patents

Abstract

To protect a leg of a pedestrian without deteriorating an external appearance.SOLUTION: A bumper 11 has: a bumper front plate part 11a which crosses a cross section in the front of an energy absorption member 6; and a bumper lower plate part 11b which extends backward from a lower end of the bumper front plate part 11a. An air bag 22 is stored above the bumper lower plate part 11b and forward with respect to a projection 17 of an undercover 12 in a contracted state at normal time. A deployment direction of the air bag 22 is set to a direction toward a top face of the bumper lower plate part 11b. A collision determination part of ECU detects collision of a pedestrian with a front face part of a vehicle 1. When an air bag control part of ECU operates an inflator 21, the air bag 22 is deployed and presses the bumper lower plate part 11b from above, the bumper lower plate part 11b deforms without breaking by deployment force of the air bag 22, and inclines lower forward with respect to the bumper front plate part 11a.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a pedestrian protection device for a vehicle.

Patent Document 1 describes a pedestrian protection airbag device that prevents the pedestrian's legs from being caught while securing an approach angle. This pedestrian protection airbag device deploys an airbag to protect a colliding object such as a pedestrian (particularly a leg portion) at the time of a vehicle collision such as when a pedestrian collides with a front bumper of the vehicle. The front bumper includes a bumper cover, a shock absorbing member accommodated in the bumper cover, an under cover connected to the bumper cover and extending below the vehicle and obliquely rearward of the vehicle, and a bumper reinforcement connected to the shock absorbing member. And have. The undercover of the front bumper is arranged along the approach angle line so as to form an approach angle. The inflator and the airbag are attached to a lower portion of the bumper reinforcement so that the airbag deploys forward of the vehicle and obliquely downward of the vehicle upon collision of the vehicle. When the airbag is deployed in front of the vehicle and diagonally below the vehicle, the inflation force of the airbag is applied to the back surface of the undercover, and the inflation force of this airbag presses the undercover of the front bumper, and the hinged door section is opened. Centering on the section, it opens to the front of the vehicle and is in an open state. Of the legs of the pedestrian, the bumper cover of the front bumper should come into contact with the upper side (above the knees) and the lower door (below the knees) should come into contact with the open door of the undercover. This prevents the pedestrian's legs from being caught under the front bumper. It is also disclosed that when the airbag is deployed forward of the vehicle and obliquely downward of the vehicle, the undercover is ruptured along the groove formed in the shape of a single-sided door due to the expansion force of the airbag.

JP, 2008-37246, A

In the pedestrian protection airbag device described in Patent Document 1, a hinge portion that connects the bumper cover and the under cover of the front bumper in order to deploy the airbag attached to the lower portion of the bumper reinforcement below the bumper cover. Or the groove that can be ruptured by the inflation force of the airbag is provided in the under cover, the appearance of the lower part of the front end of the vehicle may deteriorate due to the hinge portion or the groove.

Therefore, an object of the present disclosure is to provide a pedestrian protection device for a vehicle that can protect the legs of a pedestrian without deteriorating the appearance.

In order to solve the above problems, the vehicle pedestrian protection device according to the first aspect of the present invention includes a bumper, an airbag unit, a collision detection unit, and a control unit. The bumper has a bumper front plate portion that extends in the vehicle width direction while intersecting with the front-rear direction of the vehicle, and a bumper lower plate portion that is integrally formed with the bumper front plate portion and extends rearward from the lower end of the bumper front plate portion. , Extends in the vehicle width direction at the lower front end of the vehicle. The airbag unit has an inflator that generates gas and an airbag that is inflated by the gas generated by the inflator, and is arranged behind the bumper front plate part and above the bumper lower plate part and supported on the vehicle body side. To be done. The collision detection means detects a pedestrian's collision with the front surface of the vehicle. The control means actuates the inflator in response to the detection of the collision of the pedestrian by the collision detection means. The deployment direction of the airbag is set so that the lower bumper plate portion can be pressed downward. The bumper lower plate portion is deformed so as to be tilted downward and forward with respect to the bumper front plate portion by the deployment force of the airbag.

In the above structure, the bumper lower plate portion is deformed so as to be tilted downward and forward with respect to the bumper front plate portion by the deployment force of the airbag. Therefore, when the control means actuates the inflator in response to the detection of the collision of the pedestrian by the collision detection means, the airbag is inflated by the gas generated by the inflator, and the bumper lower plate is caused by the deployment force of the airbag. Tilt downward and forward with respect to the section. In this way, when the pedestrian collides with the front part of the vehicle, the lower bumper plate is tilted downward and forward, so when the leg of the pedestrian collides with the bumper, the lower leg of the pedestrian (front bumper plate). The lower part of the bumper lower part) can be brought into contact with the bumper lower plate part, and the lower leg part of the pedestrian can be prevented from slipping under the bumper by the bumper lower plate part. .. Therefore, bending of the legs of the pedestrian can be suppressed, and the legs of the pedestrian can be protected.

Further, the bumper lower plate portion is deformed so as to be tilted downward and forward with respect to the bumper front plate portion by the deployment force of the airbag. In this way, since the bumper is deformed by the deployment force of the airbag to tilt the bumper lower plate portion downward and forward, for example, a groove for breaking the bumper or a hinge for tilting the bumper lower plate portion is provided. Unlike the case of providing such as, it is possible to suppress the deterioration of the appearance.

A second aspect of the present invention is the vehicle pedestrian protection device of the first aspect, which includes a support surface portion. The support surface portion has a rigidity higher than that of the bumper, is arranged at a position spaced apart rearward from the bumper front plate portion, and defines a rear side of a deployment region where the airbag is deployed.

In the above configuration, the supporting surface portion having a rigidity higher than that of the bumper defines the rear side of the deployment region where the airbag is deployed, so that the rearward deployment of the airbag to be deployed can be restricted to the supporting surface portion. That is, the bumper front plate portion stands upright in front of the airbag deployment region, and the support surface portion is provided behind the airbag deployment region, so that the airbag to be deployed is divided into the bumper front plate portion and the support surface portion. It is possible to guide to the lower bumper lower plate portion side by. Therefore, the deploying force of the airbag can be suitably applied to the bumper lower plate portion, and the bumper lower plate portion can be tilted downward and forward.

Further, since the support surface portion is provided behind the deployment area of the airbag, the rearward movement of the deployed airbag can be restricted by the support surface portion. Therefore, when the lower leg of the pedestrian comes into contact with the lower bumper plate that is tilted forward and downward by the deploying force of the airbag, the rearward movement of the lower bumper plate and the airbag is suppressed by the support surface portion. Since it is possible to prevent the lower leg of the pedestrian from diving below the vehicle, the bumper lower plate portion can be suitably suppressed, and the bending of the leg of the pedestrian can be suppressed, so that the leg of the pedestrian can be prevented. Can be protected.

According to the present disclosure, it is possible to protect the legs of a pedestrian without deteriorating the appearance.

1 is a side view of a vehicle to which a pedestrian protection device according to an embodiment of the present invention is applied. It is a schematic side view of the front end part of the vehicle of FIG. It is a block diagram of a pedestrian protection device. FIG. 3 is a schematic side view corresponding to FIG. 2, showing a state in which the airbag is deployed.

An embodiment of the present invention will be described below with reference to the drawings. In each drawing, FR indicates the front of the vehicle, UP indicates the upper side, and IN indicates the inner side in the vehicle width direction. In the following description, the front-rear direction means the front-rear direction of the vehicle, and the left-right direction means the left-right direction when facing the front of the vehicle.

As shown in FIGS. 1 and 2, a vehicle 1 to which the pedestrian protection device 10 according to the present embodiment is applied is, for example, a vehicle with a frame in which a cab 2 is elastically supported by a vehicle body frame 3. The body frame 3 includes a pair of left and right side members 4 (only the left side member 4 is shown in FIG. 1) extending in the front-rear direction on both sides in the vehicle width direction, and extending in the vehicle width direction to the left and right. Is a ladder-shaped frame (ladder frame) having a plurality of cross members (not shown) that connect the side members 4 of each other. A high-rigidity bumper beam 5 formed in a rod shape extending in the vehicle width direction is fixed to the front end portion of the vehicle body frame 3, and a front surface of the bumper beam 5 is formed of a thin metal plate and has a higher rigidity than the bumper beam 5. The energy absorbing member 6 having low rigidity is fixed. When the colliding object collides with the front surface of the vehicle 1, the energy absorbing member 6 is pressed from the front by the colliding object and deformed while being supported by the bumper beam 5 from the rear side to absorb the collision energy.

As shown in FIGS. 1 to 3, a pedestrian protection device 10 includes a bumper 11, an undercover 12, a vehicle front camera (collision detection means) 13, a millimeter wave radar (collision detection means) 14, and an air. A bag unit 15 and a control unit 16 (hereinafter referred to as an ECU (Electronic Control Unit) 16) are provided.

The bumper 11 is formed of a resin plate-shaped member, is disposed at the lower front end of the vehicle 1, extends in the vehicle width direction in front of the bumper beam 5 and the energy absorbing member 6, and is fixed to the cab 2. The bumper 11 has a bumper front plate portion 11a that crosses the energy absorbing member 6 in the front-rear direction, and a bumper lower plate portion 11b that extends rearward from the lower end of the bumper front plate portion 11a. The bumper front plate portion 11a is fixed to the cab 2 while covering the bumper beam 5 and the energy absorbing member 6 from the front. The bumper lower plate portion 11b is integrally formed with the bumper front plate portion 11a, and is disposed below the energy absorbing member 6 in a state of intersecting with the vertical direction. Below the vehicle body frame 3, behind the bumper front plate portion 11a, and above the bumper lower plate portion 11b, a deployment region 19 in which an airbag 22 of the airbag unit 15 to be described later is deployed is defined. That is, the vehicle body frame 3, the bumper beam 5, and the energy absorbing member 6 partition the upper part of the deployment area 19, and the rear surface of the bumper front plate portion 11a partitions the front of the deployment area 19 and the bumper lower plate portion 11b. The upper surface defines the lower part of the development area 19. The plate thickness of the bumper 11 is set to a plate thickness that can be deformed by the deployment force of the airbag 22. The bumper lower plate portion 11b extends rearward from the lower end of the bumper front plate portion 11a without receiving an external force during normal operation.

The under cover 12 is a cover arranged below the front end of the vehicle 1 to cover and protect the front end of the vehicle 1 from below. The under cover 12 is formed of a metal plate member and is fixed to the vehicle body frame 3. .. The under cover 12 extends rearward and downward from a cover upper end portion 18 arranged behind the bumper lower plate portion 11b, and covers a space 20 behind the bumper 11 from below. In the space 20 behind the bumper 11, the bumper beam 5, the energy absorbing member 6, the front end portion of the vehicle body frame 3, the airbag unit 15 described later, and the like are arranged. The under cover 12 is arranged above a line (in the present embodiment, a tangent line 8 (see FIG. 1) between the lower end of the bumper 11 and the outer periphery of the front tire 7 of the vehicle 1 in this embodiment). .. A projecting portion 17 projecting upward from the upper surface 12a of the under cover 12 is integrally formed near the lower end of the cover upper end portion 18. That is, the protruding portion 17 is formed of a metal plate-shaped member having higher rigidity than the bumper 11. The protruding portion 17 is formed in a plate shape that intersects with the front-rear direction, is spaced apart rearward from the bumper front plate portion 11 a, is disposed rearward of the airbag unit 15, and extends over the left and right sides of the under cover 12, It opposes the front plate portion 11a. A front surface portion (support surface portion) 23 of the protruding portion 17 defines a rear portion of a deployment region 19 of an airbag 22 of the airbag unit 15, which will be described later. In the present embodiment, the undercover 12 is arranged above the line forming the approach angle of the vehicle 1, but the present invention is not limited to this, and the undercover 12 itself forms the approach angle of the vehicle 1. You may.

The vehicle front camera 13 is provided on an upper part of a front window (not shown) of the cab 2, sequentially captures moving images within a predetermined angle range in front of the vehicle 1, and displays still images forming the captured moving images. It is digitally converted and output to the ECU 16 as moving image information.

The millimeter-wave radar 14 is provided below the front surface of the cab 2 and repeatedly emits a transmission wave, which is a continuous electromagnetic wave in the millimeter-wave band, toward the front within a range of a predetermined angle at predetermined time intervals, and in front of the vehicle 1. Received waves that are reflected waves from an object (object (pedestrian, etc.)) existing in the. The millimeter wave radar 14 sequentially detects the distance from the front surface of the cab 2 to the target object, the elevation/depression angle, and the azimuth angle based on the front-rear direction, and outputs a signal including the detected information to the ECU 16.

As shown in FIGS. 2 and 4, the airbag unit 15 includes an inflator 21 that generates gas under the control of the ECU 16, and an airbag 22 that inflates and expands due to the gas generated by the inflator 21. It is fixed to the lower surface portion of the bumper beam 5 above the bumper lower plate portion 11b and in front of the protruding portion 17 of the under cover 12. The airbag 22 is housed in the airbag unit 15 above the bumper lower plate portion 11b and in front of the protruding portion 17 of the under cover 12 in a normally contracted state. The deployment direction of the airbag 22 is set to the direction toward the upper surface of the bumper lower plate portion 11b (lower front in this embodiment). The size of the airbag 22 is such that the airbag 22 extends in the vehicle width direction below the front end portion of the vehicle body frame 3 in the expanded state, and can push the bumper lower plate portion 11b from above and tilt it to the lower front. Is set.

The ECU 16 includes a CPU (Central Processing Unit) 24, a storage unit (RAM (Random Access Memory), ROM (Read Only Memory), etc.) 25, and the like. The CPU 24 functions as a collision determination unit (collision detection unit) 26 and an airbag control unit (control unit) 27 by executing various programs stored in the storage unit 25. The storage unit 25 has a temporary storage area for various received information, a temporary storage area for the calculation result of the CPU 24, and the like.

Whether the collision determination unit 26 cannot avoid a collision with a pedestrian from the signal input from the millimeter wave radar 14 and the image information (hereinafter referred to as image information) input from the vehicle front camera 13 Determine whether or not. For example, the collision determination unit 26 acquires the distance and the relative speed of the pedestrian in front of the vehicle 1 from the image information and the like, and divides the distance by the relative speed to predict the collision between the vehicle 1 and the pedestrian. A state in which a collision with a pedestrian cannot be avoided when the time (TTC (Time To Collision)) is calculated, the predicted collision time is compared with a preset threshold, and the predicted collision time is lower than the threshold. It is determined that When it is determined that the collision with the pedestrian cannot be avoided, the collision determination unit 26 determines that the pedestrian collides with the front surface of the vehicle 1 and detects the collision of the pedestrian with the front surface of the vehicle 1. To do. That is, the collision determination unit 26, the millimeter wave radar 14, and the vehicle front camera 13 function as a collision detection unit that detects a collision of a pedestrian on the front surface of the vehicle 1.

The airbag control unit 27 operates the inflator 21 of the airbag unit 15 when the collision determination unit 26 detects a pedestrian's collision with the front surface of the vehicle 1.

In the pedestrian protection device 10 configured as described above, when the collision determination unit 26 detects a pedestrian collision on the front surface of the vehicle 1 and the airbag control unit 27 operates the inflator 21, the inflator 21 is generated. Due to the gas, the airbag 22 deploys in the deployment area 19 toward the upper surface of the bumper lower plate portion 11b. The frontward deployment of the airbag 22 is regulated by the bumper front plate portion 11a, and the rearward deployment of the airbag 22 is regulated by the front surface portion 23 of the protruding portion 17 of the under cover 12 and the upward airbag 22. Is restricted by the body frame 3, the bumper beam 5, and the energy absorbing member 6. When the deploying airbag 22 presses the bumper lower plate portion 11b from above, the bumper lower plate portion 11b is deformed by the deploying force of the airbag 22 without breaking and tilts forward and downward with respect to the bumper front plate portion 11a. (See FIG. 4). In this way, since the bumper lower plate portion 11b is tilted downward and forward in response to a pedestrian's collision with the front surface of the vehicle 1, the pedestrian's lower leg portion collides with the bumper 11 when the pedestrian's leg portion collides with the bumper 11. It is possible to bring the lower part of the pedestrian into the lower part of the bumper 11 by allowing the lower part of the pedestrian to come into contact with the lower part of the bumper 11b. It can be suppressed by the portion 11b. Therefore, bending of the legs of the pedestrian can be suppressed, and the legs of the pedestrian can be protected.

Further, at a normal time, the airbag 22 is stored in a state of being contracted upward from the bumper lower plate portion 11b, and the bumper lower plate portion 11b extends rearward from the lower end of the bumper front plate portion 11a without tilting forward and downward. Therefore, the approach angle of the vehicle 1 at the normal time can be reliably ensured. Therefore, while normally ensuring the approach angle of the vehicle 1, when the vehicle collides with a pedestrian, the bumper lower plate portion 11b is tilted downward and forward by the deploying force of the airbag 22 and the pedestrian below the bumper 11 is inflated. It is possible to prevent the lower leg part from slipping in.

Further, the bumper lower plate portion 11b is deformed with respect to the bumper front plate portion 11a by the deployment force of the airbag 22 and tilts downward and forward. Thus, the bumper 11 is deformed by the deployment force of the airbag 22 and the bumper lower plate portion 11b is tilted downward and forward. Therefore, for example, a groove for breaking the bumper 11 or the bumper lower plate portion 11b is Unlike the case where a hinge or the like for tilting is provided, it is possible to suppress deterioration of the external appearance of the lower front end of the vehicle 1.

Further, the frontward deployment of the airbag 22 is restricted by the bumper front plate portion 11a, and the rearward deployment of the airbag 22 is restricted by the front surface portion 23 of the projecting portion 17 of the undercover 12, and the upward airflow is controlled. The deployment of the bag 22 is restricted by the vehicle body frame 3, the bumper beam 5, and the energy absorbing member 6. In this way, the rearward deployment of the airbag 22 is regulated by the front surface portion 23 of the protruding portion 17 of the under cover 12 having a higher rigidity than the bumper 11, so that the deployed airbag 22 is disposed on the bumper lower plate portion 11b side. The bumper lower plate portion 11b can be tilted downward and forward by appropriately applying the deploying force of the airbag 22 to the bumper lower plate portion 11b.

Further, since the front surface portion 23 of the protruding portion 17 of the under cover 12 is provided behind the deployment area 19 of the airbag 22, the lower leg portion of the pedestrian comes into contact with the bumper lower plate portion 11b tilted downward and forward. At this time, the rearward movement of the bumper lower plate portion 11b and the airbag 22 can be suppressed by the front surface portion 23 of the protruding portion 17 of the under cover 12. Therefore, the bumper lower plate portion 11b can suitably prevent the lower leg portion of the pedestrian from going under the vehicle 1, and suppress the bending of the leg portion of the pedestrian so that the leg portion of the pedestrian can be prevented. Can be protected.

Further, when the colliding object collides with the front surface of the vehicle 1, the energy absorbing member 6 is pressed from the front by the colliding object to be deformed while being supported by the bumper beam 5 from the rear side, and absorbs the collision energy. When the leg of the pedestrian collides with the bumper 11, the energy absorbing member 6 can absorb the collision energy, and the leg of the pedestrian can be protected.

Therefore, according to this embodiment, the lower leg of the pedestrian can be supported from the rear with a simple structure to protect the leg of the pedestrian.

In the present embodiment, the undercover 12 is provided with the protruding portion 17 and the front surface (supporting surface portion) 23 of the protruding portion 17 partitions the rear of the deployment region 19 of the airbag 22, but the present invention is not limited to this. Instead, for example, another member separate from the under cover 12 may be provided with a support surface portion that partitions the rear of the deployment region 19 of the airbag 22. Further, in the present embodiment, the projecting portion 17 (member having the supporting surface portion) is formed of a metal plate-shaped member, but the present invention is not limited to this, and the member having the supporting surface portion has higher rigidity than the bumper 11. Should have.

Further, in the present embodiment, the under cover 12 is formed of a metal plate member, but the material of the under cover 12 is not limited to this. For example, the under cover 12 may be made of a material such as resin or foam.

Further, in the present embodiment, the energy absorbing member 6 is formed of a thin metal plate, but the material of the energy absorbing member 6 is not limited to this. For example, the energy absorbing member 6 may be made of a material such as resin or foam.

Further, in the present embodiment, the deploying direction of the airbag 22 is set to the front lower side, but the present invention is not limited to this, and it may be any direction capable of pressing the bumper lower plate portion 11b downward. For example, even if the deploying direction of the airbag 22 is set to the front and the deploying airbag 22 contacts the bumper front plate portion 11a and then inflates downward, the bumper lower plate portion 11b is pressed downward. Good.

Further, in the present embodiment, the airbag unit 15 is fixed to the lower surface portion of the bumper beam 5, but the present invention is not limited to this, and it is rearward of the bumper front plate portion 11a and higher than the bumper lower plate portion 11b. May be fixed to other members as long as they are arranged in.

In addition, in the present embodiment, when the collision determination unit 26 determines that the collision with the pedestrian cannot be avoided, it is determined that the pedestrian collides with the front surface portion of the vehicle 1 and the front surface portion of the vehicle 1 is determined. Although the collision of the pedestrian is detected, the method of detecting the collision of the pedestrian on the front surface of the vehicle 1 is not limited to this. For example, the bumper 11 may be provided with an acceleration sensor, a pressure sensor, or the like, and an actual collision with the bumper 11 may be detected to detect a pedestrian's collision with the front portion of the vehicle 1.

Further, in the present embodiment, the undercover 12 is fixed to the body frame 3 side and the bumper 11 is fixed to the cab 2 side. However, the present invention is not limited to this, and for example, both the bumper 11 and the undercover 12 are fixed. It may be fixed to the body frame 3 side.

The present invention has been described above based on the above embodiment, but the present invention is not limited to the contents of the above embodiment, and can of course be appropriately modified without departing from the present invention. That is, it goes without saying that all other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are included in the scope of the present invention.

For example, the pedestrian protection device 10 according to the present disclosure may be applied to vehicles other than a vehicle with a frame.

The pedestrian protection device according to the present disclosure can be widely applied to various vehicles.

1: Vehicle 10: Pedestrian protection device 11: Bumper 11a: Bumper front plate part 11b: Bumper lower plate part 12: Under cover 13: Vehicle front camera (collision detection means)
14: Millimeter wave radar (collision detection means)
15: Airbag unit 17: Undercover protrusion 19: Airbag deployment region 21: Inflator 22: Airbag 23: Front face of the undercover protrusion (support surface)
26: Collision determination unit (collision detection means)
27: Airbag control unit (control means)

Claims (2)

A bumper front plate portion that extends in the vehicle width direction while intersecting with the vehicle front-rear direction; and a bumper lower plate portion that is integrally molded with the bumper front plate portion and extends rearward from the lower end of the bumper front plate portion, A bumper extending in the vehicle width direction at the lower front end of the vehicle,
It has an inflator that generates gas and an airbag that is deployed by the gas that the inflator generates, and is arranged behind the bumper front plate portion and above the bumper lower plate portion and is supported on the vehicle body side. An airbag unit,
Collision detection means for detecting a collision of a pedestrian on the front part of the vehicle,
Control means for operating the inflator according to detection of a collision of a pedestrian by the collision detection means,
The deployment direction of the airbag is set to a direction in which the bumper lower plate portion can be pressed downward,
The pedestrian protection device for a vehicle, wherein the bumper lower plate portion is deformed so as to be tilted downward and forward with respect to the bumper front plate portion by a deployment force of the airbag. The pedestrian protection device for a vehicle according to claim 1,
A vehicle having a supporting surface portion that has a rigidity higher than that of the bumper, is disposed at a position spaced apart rearward from the bumper front plate portion, and defines a rear side of a deployment region in which the airbag deploys. Pedestrian protection device.

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