JP2020069944A - Pedestrian protection device for vehicle - Google Patents

Abstract

To protect leg parts of a pedestrian by supporting lower leg parts of the pedestrian from the rear side with a simple structure.SOLUTION: An undercover 12 extends to the rear-lower side from a cover upper end part 18 arranged at a position apart to the rear side from a lower end edge of a bumper 11. An air bag 22 is arranged on the upper side of a gap 19 between the bumper 11 and the undercover 12 in the contracting state at the normal time. A collision determination unit of an ECU detects collision of a pedestrian to a front part of a vehicle 1 from image information or the like input from a millimeter wave radar and a vehicle front camera. An air bag control unit of the ECU actuates an inflator 21 when the collision determination unit detects the collision of the pedestrian to the front part of the vehicle 1. When the air bag control unit actuates the inflator 21, the air bag 22 expands to a vehicle outside space 23 on the lower side of the bumper 11 and on the front side of the undercover 12 with the gas generated by the inflator 21.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 housed 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 forward 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 the airbag presses the undercover of the front bumper, and the hinged door is hinged. 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, in order to deploy the airbag attached to the lower portion of the bumper reinforcement below the bumper cover, the under cover is tilted with respect to the bumper cover via the hinge portion. The undercover is provided with a groove that can be freely connected or can be broken by the inflation force of the airbag. For this reason, the structure may be correspondingly complicated and the manufacturing cost may increase.

  Further, in the pedestrian protection airbag device described in Patent Document 1, since the rear of the undercover in the open state is supported by the airbag, the upper side (upper knee) of the leg of the pedestrian is the bumper cover. When touching the lower side of the pedestrian's leg (below the knee), the undercover may move backward together with the airbag when it contacts the single-opening door part of the undercover that has been opened. There is a possibility that the lower part of the knee of a person's leg (hereinafter referred to as the lower leg) cannot be sufficiently supported from the rear, and the leg of a pedestrian cannot be protected.

  Therefore, an object of the present disclosure is to provide a pedestrian protection device for a vehicle, which is capable of supporting the lower leg of a pedestrian from the rear with a simple structure and protecting the pedestrian's leg.

  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 undercover, an airbag unit, a collision detection unit, and a control unit. The bumper extends in the vehicle width direction below the front end of the vehicle. The under cover has a cover upper end that is arranged below the bumper with a gap provided between the lower cover and the lower end, and extends rearward and downward from the cover upper end. 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 and above the under cover. 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 airbag deploys from the gap between the bumper and the upper end of the cover of the under cover to the vehicle exterior space below the bumper and in front of the under cover.

  In the above configuration, when the control means operates the inflator in response to the detection of the collision of the pedestrian by the collision detection means, the airbag inflates into the vehicle exterior space below the bumper and in front of the undercover by the gas generated by the inflator. In this way, since the airbag is deployed below the bumper in response to a pedestrian's collision with the front part of the vehicle, when the leg of the pedestrian collides with the bumper, the lower leg of the pedestrian (collision with the bumper). The airbag can prevent the leg portion below the portion to be sunk from slipping under the bumper. Therefore, bending of the legs of the pedestrian can be suppressed, and the legs of the pedestrian can be protected.

  Further, the airbag deploys from the gap between the bumper and the upper end of the cover of the under cover to the vehicle exterior space below the bumper and in front of the under cover. In this way, since the airbag is deployed to the vehicle exterior space by utilizing the gap between the bumper and the undercover, it is difficult to deploy the airbag to the vehicle exterior space with respect to the undercover and the like (including the bumper). It is not necessary to provide a structure (for example, a structure that tilts the undercover or a structure that breaks the undercover), and deploys the airbag to the exterior space of the vehicle with a simple structure that a gap is provided between the bumper and the undercover. can do.

  Further, since the airbag deploys in the vehicle exterior space in front of the under cover, the airbag in the deployed state can be supported from the rear by the under cover. For this reason, when the lower leg of the pedestrian comes into contact with the airbag in the deployed state, the movement of the airbag to the rear can be restricted by the undercover, so that the lower leg of the pedestrian moves below the undercover. It is possible to suitably prevent the pedestrian from slipping into the air bag, suppress bending of the pedestrian's leg, and protect the pedestrian's leg.

  A second aspect of the present invention is the vehicle pedestrian protection device of the first aspect, wherein the vehicle has a vehicle body frame and a cab elastically supported by the vehicle body frame. The bumper is supported on the cab side. The under cover is supported on the vehicle body frame side.

  Generally, in a vehicle having a vehicle body frame and a cab elastically supported by the vehicle body frame (hereinafter referred to as a vehicle with a frame), the vehicle body is supported on the vehicle body frame side in order to absorb movement of the cab with respect to the vehicle body frame. A gap is provided between the member and the member supported on the cab side.

  In the above configuration, the undercover is supported on the body frame side, and the bumper is supported on the cab side elastically supported by the body frame.Therefore, the movement of the cab relative to the body frame is prevented between the undercover and the bumper. A gap is provided for absorption. That is, the air bag can be deployed to the space outside the vehicle by utilizing the gap for absorbing the movement of the cab with respect to the vehicle body frame of the vehicle with the frame, so that the structure can be simplified.

  According to the present disclosure, it is possible to protect the pedestrian's leg by supporting the pedestrian's lower leg from the rear with a simple structure.

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 FIG. 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 body frame 3, and a metal thin plate is formed on the front surface of the bumper beam 5 to make it more 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 and downward from the lower end of the bumper front plate portion 11a. The bumper front plate portion 11a covers the bumper beam 5 and the energy absorbing member 6 from the front. The bumper lower plate portion 11b is arranged below the energy absorbing member 6. The lower end edge 17 of the bumper lower plate portion 11b is located in front of the bumper beam 5 and below the bumper beam 5.

  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 rearward from a lower end edge 17 of the bumper 11, 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. A gap 19 is provided between the cover upper end portion 18 of the under cover 12 and the lower end edge 17 of the bumper 11 to absorb movement of the cab 2 with respect to the vehicle body frame 3 when the vehicle 1 is traveling. That is, when the cab 2 moves with respect to the vehicle body frame 3, the interference of the bumper 11 with the under cover 12 can be avoided by the gap 19. The under cover 12 is arranged above a line (in the present embodiment, a tangent line 8 (see FIG. 1) between the lower end edge 17 of the bumper 11 and the outer periphery of the front tire 7 of the vehicle 1 in the present embodiment). To be done. 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 portion 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 of the bumper beam 5 above the under cover 12. Normally, the airbag 22 is disposed above the gap 19 between the bumper 11 and the under cover 12 in a contracted state. When the airbag 22 is deployed under the control of the ECU 16, the airbag 22 does not deform the bumper 11 and the undercover 12 from the gap 19 between the bumper 11 and the undercover 12, and the lower portion of the bumper 11 and the undercover 12 are not deformed. The vehicle is developed toward the front exterior space 23 (hereinafter referred to as the exterior space 23) (see FIG. 4). The airbag 22 in the deployed state extends in the vehicle width direction below the bumper 11 and in front of the under cover 12.

  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. The generated gas causes the airbag 22 to expand into the vehicle exterior space 23 below the bumper 11 and in front of the under cover 12. In this way, the airbag 22 is deployed below the bumper 11 in response to a pedestrian's collision with the front part of the vehicle 1. Therefore, when the pedestrian's leg collides with the bumper 11, the pedestrian's lower leg is The airbag 22 can prevent the (leg portion below the portion that collides with the bumper 11) from slipping under the bumper 11. Therefore, bending of the legs of the pedestrian can be suppressed, and the legs of the pedestrian can be protected.

  In a normal state, the airbag 22 for preventing the lower leg of the pedestrian from slipping under the bumper 11 is arranged above the under cover 12 in a contracted state. That is, since the member (the air bag 22) for preventing the lower leg of the pedestrian from slipping under the bumper 11 is not normally arranged under the bumper 11, the approach angle of the vehicle 1 at the normal time is set. It can be ensured. Therefore, it is possible to reliably secure the approach angle of the vehicle 1 in the normal state, and to prevent the lower leg portion of the pedestrian from getting under the bumper 11 by deploying the airbag 22 when the vehicle 1 collides with the pedestrian.

  Further, the airbag 22 deploys from the gap 19 between the bumper 11 and the cover upper end portion 18 of the under cover 12 to the vehicle exterior space 23 below the bumper 11 and in front of the under cover 12. In this manner, the air bag 22 is deployed to the vehicle exterior space 23 by utilizing the gap 19 between the bumper 11 and the under cover 12, so that the air bag 22 is removed from the vehicle exterior with respect to the under cover 12 and the like (including the bumper 11). It is not necessary to provide a complicated structure (for example, a structure for tilting the undercover 12 or a structure for breaking the undercover 12) for expanding the space 23. That is, the airbag 22 can be deployed to the vehicle exterior space 23 with a simple structure in which the gap 19 is provided between the bumper 11 and the under cover 12.

  Further, since the airbag 22 is deployed in the vehicle exterior space 23 in front of the under cover 12, the deployed airbag 22 can be supported from the rear by the under cover 12. For this reason, when the lower leg of the pedestrian comes into contact with the airbag 22 in the deployed state, the movement of the airbag 22 to the rear can be restricted by the undercover 12, so that the lower leg of the pedestrian is undercovered. It is possible to suitably prevent the pedestrian from diving below 12 by the airbag 22, suppress bending of the pedestrian's leg, and protect the pedestrian's leg.

  The vehicle 1 is a vehicle with a frame in which the cab 2 is elastically supported by the vehicle body frame 3, and includes a cover upper end portion 18 of the under cover 12 supported by the vehicle body frame 3 side and a bumper 11 supported by the cab 2 side. A gap 19 for absorbing movement of the cab 2 with respect to the vehicle body frame 3 when the vehicle 1 is traveling is provided between the lower end edge 17 and the lower edge 17. Then, the airbag 22 deploys into the vehicle exterior space 23 from the gap 19 between the bumper 11 and the under cover 12. As described above, it is not necessary to provide a dedicated gap or the like for deploying the airbag 22 into the vehicle exterior space 23, and the gap 19 for absorbing the movement of the cab 2 with respect to the vehicle body frame 3 of the vehicle with a frame is utilized. Since the bag 22 is deployed in the vehicle exterior space 23, a simple structure can be obtained.

  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 bumper 11 is formed of a resin plate member, but the material of the bumper 11 is not limited to this. Further, in the present embodiment, the bumper 11 has the bumper front plate portion 11a and the bumper lower plate portion 11b, but the shape of the bumper 11 is not limited to this.

  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 cover upper end portion 18 of the under cover 12 is arranged at a position spaced apart rearward from the lower end edge 17 of the bumper 11 to provide the gap 19 between the under cover 12 and the bumper 11. , But is not limited to this. For example, a gap 19 may be provided between the undercover 12 and the bumper 11 by arranging the cover upper end portion 18 of the undercover 12 at a position separated from the lower end edge 17 of the bumper 11 upward or downward.

  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 this embodiment, the airbag 22 is deployed from the gap 19 between the bumper 11 and the cover upper end portion 18 of the undercover 12 to the vehicle exterior space 23 without deforming the bumper 11 and the undercover 12. It is not limited to. For example, when the airbag 22 deploys from the gap 19 between the bumper 11 and the cover upper end portion 18 of the undercover 12 into the vehicle exterior space 23, the bumper lower plate portion 11b of the bumper 11 is lowered by the deployment force of the airbag 22. It may be transformed into

  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 2: Cab 3: Body frame 10: Pedestrian protection device 11: Bumper 12: Undercover 13: Vehicle front camera (collision detection means)
14: Millimeter wave radar (collision detection means)
15: Airbag unit 18: Cover upper end 19: Gap 21: Inflator 22: Airbag 23: Vehicle exterior space 26: Collision determination unit (collision detection means)
27: Airbag control unit (control means)

Claims (2)

A bumper extending in the vehicle width direction at the lower front end of the vehicle,
An undercover that has a cover upper end portion that is arranged below the bumper in a state where a gap is provided between the bumper and a lower end, and extends rearward and downward from the cover upper end portion;
An inflator that generates gas and an airbag that is inflated by the gas generated by the inflator, and an airbag unit that is disposed behind the bumper and above the under cover,
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 pedestrian protection device for a vehicle, wherein the airbag is deployed from a gap between the bumper and an upper end portion of the cover of the under cover to a vehicle exterior space below the bumper and in front of the under cover. . The pedestrian protection device for a vehicle according to claim 1,
The vehicle has a body frame and a cab elastically supported by the body frame,
The bumper is supported on the cab side,
The pedestrian protection device for a vehicle, wherein the undercover is supported on the vehicle body frame side.

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