Pedestrian protection airbag system

Abstract

To reduce a secondary collision against a pedestrian.SOLUTION: In a pedestrian protection airbag device 10, a front side airbag 20 and a rear side airbag 30 are inflated and unfolded from a side sill 40 to the vehicle width direction outer side and upper side and arranged along a lateral surface of a vehicle V. The upper end part of the front side airbag 20 is arranged on the lower side with respect to the upper end part of the rear side airbag 30, and a step part 30A is formed between the front side airbag 20 and the rear side airbag 30. With this, the upper body of a pedestrian P falling to the vehicle width direction outer side of the vehicle V from the rear end side portion of a hood 78 can be caught from the lower side by the front side airbag 20 and the head of the pedestrian P can be caught from the rear side by the step part 30A. Consequently, a collision of the pedestrian P against a road surface SR can be suppressed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a pedestrian protection airbag device. [Background technology]

[0002] The pedestrian protection device described in Patent Document 1 below includes a right airbag that inflates and deploys between the rear right end of the vehicle hood and the windshield, and a left airbag that inflates and deploys between the rear left end of the vehicle hood and the windshield. The pedestrian protection device also has a collision position detection device that detects the collision position of the pedestrian in the vehicle width direction. When the collision position detection device detects the collision position of the pedestrian, a control unit controls one of the right airbag and the left airbag to inflate and deploy before the other airbag, depending on the collision position of the pedestrian. This improves protection against pedestrians who fall onto the hood. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-177981 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in a collision between a pedestrian and the front of a vehicle, the pedestrian may fall onto the hood, then fall along the side of the vehicle downwards and strike the ground. In other words, in a collision between a pedestrian and the front of a vehicle, a secondary collision of the pedestrian with the vehicle may occur. Therefore, from the perspective of improving pedestrian protection performance, it is desirable for a vehicle to have a structure that can reduce the risk of a secondary collision of the pedestrian.

[0005] In consideration of the above, an object of the present invention is to provide a pedestrian protection airbag device that can reduce the risk of a secondary collision with a pedestrian. [Means for solving the problem]

[0006] One or more embodiments of the present invention include a vehicle exterior front side airbag provided in a front portion of a side sill of a vehicle, which is inflated and deployed along the side of the vehicle by receiving a supply of gas, and a vehicle exterior rear side airbag provided in a rear portion of the side sill of the vehicle, which is inflated and deployed along the side of the vehicle by receiving a supply of gas, wherein an upper end portion of the vehicle exterior front side airbag is located lower than an upper end portion of the vehicle exterior rear side airbag. The side sill is formed with a front bag door that is torn open when the vehicle exterior front side airbag is inflated and deployed, and opens outward in the vehicle width direction from the lower end of the side sill, and a rear bag door that is torn open when the vehicle exterior rear side airbag is inflated and deployed, and opens outward in the vehicle width direction from the lower end of the side sill, and the vehicle exterior rear side airbag is supported from below the vehicle by the rear bag door, and the front bag door is disposed lower than the rear bag door, and the vehicle exterior front side airbag is disposed offset downward with respect to the vehicle exterior rear side airbag. It is a pedestrian protection airbag device.

[0008] One or more embodiments of the present invention are a pedestrian protection airbag device including: a front holding portion connected to the front bag door and holding the front bag door; a rear holding portion connected to the rear bag door and holding the rear bag door; and a holding release portion connected to the front holding portion and operable to release the holding state of the front bag door by the front holding portion and position the front bag door lower than the rear bag door on the vehicle.

[0009] One or more embodiments of the present invention provide a pedestrian protection airbag device that includes a pedestrian collision detection unit that detects a collision of a pedestrian with the vehicle, a collision detection unit that detects a side collision of a colliding object with the vehicle, and a control unit that controls operation of the retention release unit, and detects a collision of a pedestrian with the vehicle based on an output signal from the pedestrian collision detection unit and detects a side collision with the vehicle based on the output signal from the collision detection unit, wherein when the control unit detects a collision of a pedestrian with the vehicle, the control unit activates the retention release unit, and when the control unit detects a side collision of a colliding object, the control unit maintains the retention release unit in a deactivated state, and the vehicle exterior front side airbag is supported from under the vehicle by the front bag door.

[0010] One or more embodiments of the present invention are a pedestrian protection airbag device in which a tether is provided inside the exterior front side airbag that connects the lower end and upper end of the inflated and deployed exterior front side airbag, and when the retention release part is activated, a recess that is opened toward the upper side of the vehicle by the tether is formed at the upper end of the exterior front side airbag, and when the retention release part is not activated, the upper end of the tether is positioned adjacent to the outer side of the side of the vehicle in the vehicle width direction.

[0011] In one or more embodiments of the present invention, the vehicle exterior front side airbag is a pedestrian protection airbag device that includes an upper bag portion that forms an upper portion of the vehicle exterior front side airbag and a lower bag portion that forms a lower portion of the vehicle exterior front side airbag, and in which the internal pressure of the upper bag portion is lower than the internal pressure of the lower bag portion. [Effects of the Invention]

[0012] According to one or more embodiments of the present invention, secondary collisions with pedestrians can be reduced. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a side view seen from the right side of a vehicle to which a pedestrian protection airbag device according to an embodiment of the present invention is applied. [Figure 2] FIG. 1A is a right side view showing the inflated and deployed state of the front side airbag and rear side bag of the pedestrian protection airbag device during a side collision between the vehicle and a collision object, and FIG. 1B is a right side view showing the inflated and deployed state of the front side airbag and rear side bag of the pedestrian protection airbag device during a collision between the vehicle and a pedestrian. [Figure 3] 3 is a cross-sectional view (cross-sectional view taken along line 3-3 in FIG. 2A) seen from the front side, showing the inflated and deployed state of the front side airbag shown in FIG. 2A. [Figure 4] 4 is a cross-sectional view (cross-sectional view taken along line 4-4 in FIG. 2A) seen from the front side, showing the inflated and deployed state of the rear side airbag shown in FIG. 2A. [Figure 5] 5 is a cross-sectional view (cross-sectional view taken along line 5-5 in FIG. 2(B)) seen from the front side, showing the inflated and deployed state of the front side airbag shown in FIG. 2(B). [Figure 6] 1 is an explanatory diagram for explaining the behavior of a pedestrian when a vehicle collides with the pedestrian; DETAILED DESCRIPTION OF THE INVENTION

[0014] The pedestrian protection airbag device 10 according to this embodiment will be described below with reference to the drawings. Note that the arrow FR shown as appropriate in the drawings indicates the front side of the vehicle (automobile) V to which the pedestrian protection airbag device 10 is applied, the arrow UP indicates the upper side of the vehicle, and the arrow RH indicates the right side of the vehicle (one side in the vehicle width direction). In the following description, when the up-down, front-rear, and left-right directions are used, they will refer to the up-down direction of the vehicle, the front-rear direction of the vehicle, and the left-right direction of the vehicle unless otherwise specified.

[0015] The pedestrian protection airbag device 10 is provided on both sides of the vehicle V in the vehicle width direction, and is configured as a pedestrian protection device for protecting a pedestrian P who falls downward along the outer side surface of the vehicle V in the vehicle width direction. The pedestrian protection airbag device 10 is also configured as a side collision airbag device for mitigating the impact with a colliding object in the event of a side collision between the vehicle V and a colliding object. The following description will be given taking as an example a case where the pedestrian protection airbag device 10 is provided on the right side of the vehicle V.

[0016] As shown in Figures 1 to 5, the pedestrian protection airbag device 10 is configured to include an exterior front side airbag 20 (hereinafter simply referred to as the front side airbag 20) as an exterior front side airbag, an exterior rear side airbag 30 (hereinafter simply referred to as the rear side airbag 30) as an exterior rear side airbag, a front inflator 28 provided in the front side airbag 20 and supplying gas to the front side airbag 20, a rear inflator 38 provided in the rear side airbag 30 and supplying gas to the rear side airbag 30, and an ECU (Electronic Control Unit) 60 (see Figure 1) as a control unit for activating the front inflator 28 and the rear inflator 38.

[0017] The pedestrian protection airbag device 10 is disposed inside a side sill 40 (also referred to as a rocker) of the vehicle V. The side sill 40 constitutes the lower end of the right side of the vehicle V, is formed in a generally hollow columnar shape extending in the front-to-rear direction, and is disposed between a front wheel 70 and a rear wheel 72 of the vehicle V. The front side airbag 20 and the front inflator 28 in a folded state are housed in a front portion of the side sill 40, and the rear side airbag 30 and the rear inflator 38 in a folded state are housed in a rear portion of the side sill 40. The front inflator 28 and the rear inflator 38 are formed in a generally cylindrical shape with their axial directions aligned in the front-to-rear direction, and are electrically connected to the ECU 60. When the front inflator 28 (rear inflator 38) is activated by the ECU 60, gas ejected from the front inflator 28 (rear inflator 38) is supplied to the front side airbag 20 (rear side airbag 30), causing the front side airbag 20 (rear side airbag 30) to inflate and deploy.

[0018] Furthermore, as the front side airbag 20 and the rear side airbag 30 inflate and deploy, the front side airbag 20 and the rear side airbag 30 open the front bag door 42 and the rear bag door 44 formed on the side sill 40, and the front side airbag 20 and the rear side airbag 30 are inflated and deployed on the right side of the vehicle V. Below, the structures of the front bag door 42 and the rear bag door 44 will be described first, and then the front side airbag 20, the rear side airbag 30, and the ECU 60 will be described.

[0019] (Regarding the front bag door 42 and the rear bag door 44) A tear portion 40A (see FIG. 1) that is torn open by the inflation pressure of the front side airbag 20 is formed in the front portion of the outer wall of the side sill 40 in the vehicle width direction, and the inner portion of the tear portion 40A in the side sill 40 constitutes a front bag door 42. Furthermore, a tear portion 40B (see FIG. 1) that is torn open by the inflation pressure of the rear side airbag 30 is formed in the rear portion of the outer wall of the side sill 40 in the vehicle width direction, and the inner portion of the tear portion 40B in the side sill 40 constitutes a rear bag door 44. When the pedestrian protection airbag device 10 is activated, the front bag door 42 and the rear bag door 44 open so as to tilt outward in the vehicle width direction, and the side sill 40 is opened. Specifically, the front bag door 42 has a hinge portion 42A connected to the side sill 40, and opens to extend outward in the vehicle width direction from the hinge portion 42A (position shown in FIG. 3, hereinafter this position of the front bag door 42 will be referred to as the open position). Similarly, the rear bag door 44 has a hinge portion 44A connected to the side sill 40, and opens to extend outward in the vehicle width direction from the hinge portion 44A (position shown in FIG. 4, hereinafter this position of the rear bag door 44 will be referred to as the open position).

[0020] The front bag door 42 is connected to a front bag door holding portion 50 serving as a front holding portion provided within the side sill 40 (see FIG. 3). The front bag door holding portion 50 is formed of a string-like member, and the front bag door 42 is held in the open position by the front bag door holding portion 50. Similarly to the front bag door 42, the rear bag door 44 is connected to a rear bag door holding portion 52 serving as a rear holding portion provided within the side sill 40 and also formed of a string-like member (see FIG. 4), and the rear bag door 44 is held in the open position by the rear bag door holding portion 52.

[0021] An actuator 54 is provided within the side sill 40 as a retention release unit for releasing the retention state of the front bag door 42 by the front bag door retaining portion 50 (see FIG. 3 ). The actuator 54 is connected to the front bag door retaining portion 50. The actuator 54 includes, for example, a cylinder, a piston housed in the cylinder and connected to the front bag door retaining portion 50, and a gas generation unit provided within the cylinder, and is electrically connected to an ECU 60 (described later). In the event of a collision between the vehicle V and a pedestrian P, the actuator 54 is activated by the ECU 60 to break the front bag door retaining portion 50 with the actuator 54. Specifically, gas generated by the gas generation fills the cylinder, and the piston moves relative to the cylinder due to the gas pressure within the cylinder, thereby breaking the front bag door retaining portion 50. As a result, as shown in FIG. 5 , the retention state of the front bag door 42 by the front bag door retaining portion 50 is released, allowing the front bag door 42 to be opened to a greater extent. When the front bag door holding portion 50 is released from its holding state on the front bag door 42, the front bag door 42 opens further from the open position around the hinge portion 42A and is positioned in an expanded position (see the position shown in Figure 5) that is lower than the open position.

[0022] (Regarding front side airbags 20) 2, 3, and 5, the front side airbag 20 is formed into a bag shape by sewing together the outer peripheries of a plurality of base fabrics, for example. Specifically, when the front side airbag 20 is inflated and deployed, the front side airbag 20 is formed into a substantially rectangular bag shape when viewed from the right side, with the thickness direction being the left-right direction. The front side airbag 20 also includes a lower bag portion 22 that forms a lower portion of the front side airbag 20, and an upper bag portion 24 that forms an upper portion of the front side airbag 20. The upper bag portion 24 has a substantially inverted U-shaped cross section that is open downward in a cross section viewed from the front-rear direction, and the lower opening of the upper bag portion 24 is joined to the upper end of the lower bag portion 22 by sewing or the like, with the lower opening folded inward in the thickness direction. The upper end of the lower bag portion 22, where it is sewn to the upper bag portion 24, forms a partition wall 22A, and a plurality of communication holes 22B (see FIGS. 3 and 5) are formed through the partition wall 22A and are aligned in the front-to-rear direction. This allows the lower bag portion 22 and the upper bag portion 24 to communicate with each other through the communication holes 22B. The upper bag portion 24 also has a vent hole 24A (see FIGS. 2A and 2B) formed therein, so that the internal pressure of the upper bag portion 24 is lower than that of the lower bag portion 22.

[0023] When supplied with gas from the front inflator 28, the front side airbag 20 is inflated and deployed from the front of the side sill 40 outward and upward in the vehicle width direction, and is positioned along the outer surface of the lower part of the front side door 74 of the vehicle V. More specifically, when the front bag door 42 is in the open position, the lower end of the lower bag portion 22 is positioned outward in the vehicle width direction of the side sill 40 and is supported from below by the front bag door 42 (see FIG. 3). On the other hand, when the front bag door 42 is in the expanded position, the lower end of the lower bag portion 22 is positioned diagonally below the right side of the side sill 40 and abuts against the road surface SR, thereby being supported from below by the road surface SR (see FIG. 5). That is, when the front bag door 42 is in the expanded position, the front side airbag 20 is positioned lower than when the front bag door 42 is in the open position. More specifically, when the front bag door 42 is in the expanded position, the upper end of the front side airbag 20 is positioned below the hood 78 of the vehicle V and is configured to receive from below the head and upper body of a pedestrian P who falls onto the right side of the vehicle V (see Figure 2(B)).

[0024] Furthermore, a plurality of tethers 26 are provided inside the front side airbag 20, connecting the lower end and the upper end of the front side airbag 20. The tethers 26 are formed in a generally long string shape, with one end (lower end) of the tethers 26 being connected to a position on the lower bag portion 22 that generally corresponds to the tip of the front bag door 42, and the other end (upper end) of the tethers 26 being connected to the upper end portion of the upper bag portion 24. When the front bag door 42 is in the expanded position, the tethers 26 restrict the vertical position of the upper end of the front side airbag 20, and a recess 20A that is open upward is formed in the upper end of the front side airbag 20 (see FIG. 5). On the other hand, when the front bag door 42 is in the open position, the other end (upper end) of the tether 26 is disposed adjacent to the outer side of the front side door 74 of the vehicle V in the vehicle width direction, and is configured to pull the front side airbag 20 toward the front side door 74 by the tether 26, thereby maintaining a good positioning posture of the front side airbag 20. The tether 26 is inserted through the communication hole 22B of the front side airbag 20, and connects the lower end and upper end of the front side airbag 20 together.

[0025] (Regarding rear side airbags 30) 2, 4, and 5, the rear side airbag 30 has the same configuration as the front side airbag 20. That is, when the rear side airbag 30 is inflated and deployed, the rear side airbag 30 is formed in a generally rectangular bag shape when viewed from the right side, with the thickness direction extending in the left-right direction. The rear side airbag 30 also includes a lower bag portion 32 that forms the lower part of the rear side airbag 30, and an upper bag portion 34 that forms the upper part of the rear side airbag 30, and the lower end of the upper bag portion 34 is joined to the upper end of the lower bag portion 32 by sewing or the like. The rear end of the upper bag portion 34 of the rear side airbag 30 protrudes rearward beyond the upper bag portion 34 in correspondence with the wheelhouse of the vehicle V. A plurality of communication holes 32B (see FIG. 4) are formed through a partition wall 32A at the upper end of the lower bag portion 32. Furthermore, a vent hole 34A (see Figures 2(A) and (B)) is formed in the upper bag portion 34, and the internal pressure of the upper bag portion 34 is configured to be lower than the internal pressure of the lower bag portion 32.

[0026] In addition, multiple tethers 36 (see Figure 4) that connect the lower end and upper end of the rear side airbag 30 are provided inside the rear side airbag 30, and the tethers 36 are inserted through the communication holes 32B of the rear side airbag 30.

[0027] When the rear inflator 38 is activated, the rear side airbag 30 is inflated and deployed from the rear of the side sill 40 outward and upward in the vehicle width direction, and is disposed along the outer surface of the rear side door 76 of the vehicle V and adjacent to the rear side airbag 20. The lower end of the lower bag portion 32 of the rear side airbag 30 is disposed outward in the vehicle width direction from the side sill 40 and is supported from below by the rear bag door 44 in the open position. Furthermore, when the front bag door 42 is disposed in the expanded position, the upper end of the rear side airbag 30 is disposed higher than the upper end of the front side airbag 20, forming a step 30A between the front side airbag 20 and the rear side airbag 30 (see FIGS. 2(B) and 5). This allows the step 30A to catch a pedestrian P falling onto the front side airbag 20 and prevent the pedestrian P from moving rearward. As with the front side airbag 20, the tether 36 of the rear side airbag 30 is positioned adjacent to the outer side of the rear side door 76 of the vehicle V in the vehicle width direction, and is configured to pull the rear side airbag 30 toward the rear side door 76 by the tether 36, thereby maintaining the rear side airbag 30 in a good position.

[0028] (About ECU60) 1, the front inflator 28, the rear inflator 38, and the actuator 54 are electrically connected to the ECU 60. The front inflator 28, the rear inflator 38, and the actuator 54 are activated by the control of the ECU 60.

[0029] The ECU 60 is also electrically connected to a collision detection sensor 62 and a collision prediction sensor 64 as a collision detection unit provided in the vehicle V, and a pedestrian collision detection sensor 66 as a pedestrian collision detection unit.

[0030] The collision detection sensor 62 is composed of an acceleration sensor and the like, and is provided on the outer periphery of the vehicle V. The collision detection sensor 62 measures acceleration and the like input to the vehicle V and outputs the measurement data to the ECU 60. The collision prediction sensor 64 is composed of a stereo camera and the like. The collision prediction sensor 64 photographs the surroundings of the vehicle V and detects an object colliding with the vehicle V. The collision prediction sensor 64 also measures the distance to the detected object, the relative speed between the vehicle V and the object, and the like, and outputs the measurement data to the ECU 60. The ECU 60 then detects a collision with the vehicle V, such as a frontal collision or a side collision, based on the output signals from the collision detection sensor 62 and the collision prediction sensor 64.

[0031] The pedestrian collision detection sensor 66 is provided in front of a bumper beam (not shown) of a front bumper 80 located at the front end of the vehicle V. This pedestrian collision detection sensor 66 includes a substantially elongated pressure tube whose longitudinal direction is the vehicle width direction, and pressure sensors provided at both longitudinal ends of the pressure tube. A signal corresponding to a change in pressure inside the pressure tube is output from the pedestrian collision detection sensor 66 to the ECU 60, and the ECU 60 determines whether the object that has collided with the front of the vehicle V is a pedestrian or an obstacle other than a pedestrian.

[0032] Furthermore, when the ECU 60 detects a side collision between the vehicle V and a colliding object based on output signals from the collision detection sensor 62 and the collision prediction sensor 64, the ECU 60 activates the front inflator 28 and the rear inflator 38. When the ECU 60 detects a collision between the front of the vehicle V and a pedestrian based on output signals from the collision detection sensor 62, the collision prediction sensor 64, and the pedestrian collision detection sensor 66, the ECU 60 activates the front inflator 28, the rear inflator 38, and the actuator 54. That is, in the event of a side collision of the vehicle V, the actuator 54 does not activate and the front bag door 42 opens to the open position, and in the event of a collision between the vehicle V and a pedestrian P, the actuator 54 activates and the front bag door 42 opens to the expanded position due to the inflation pressure of the front side airbag 20.

[0033] (Action and effect) Next, the behavior of the pedestrian P when the pedestrian P collides with the vehicle V near the front right corner and the operation of the pedestrian protection airbag device 10 will be explained, while the operation and effect of this embodiment will be explained.

[0034] FIG. 6 illustrates, in chronological order, the behavior of pedestrian P when pedestrian P collides with the front right corner of vehicle V. As shown in (1) to (3) of FIG. 6, in the early stage of the collision between vehicle V and pedestrian P, the front bumper 80 at the front end of vehicle V flips up the legs of pedestrian P, causing pedestrian P to fall onto the right side (right end) of the hood 78 of vehicle V. Then, as shown in (4) to (6) of FIG. 6, in the later stage of the collision between vehicle V and pedestrian P, pedestrian P, who has fallen onto the right side (right end) of the hood 78 of vehicle V, falls from the rear end of the hood 78 of vehicle V outward in the vehicle width direction of the front side door 74 of vehicle V. As a result, pedestrian P slides down along the outer surface of front side door 74 of vehicle V (see the arrow in FIG. 2(B)), which may result in pedestrian P colliding with road surface SR. Although not shown in the figure, in the event of a collision between pedestrian P and vehicle V, the rear end of hood 78 is lifted and a pedestrian protection hood airbag is inflated and deployed from between hood 78 and windshield glass 82 toward front pillar 84, thereby protecting pedestrian P who falls onto hood 78.

[0035] In the event of a collision between the vehicle V and the pedestrian P, the ECU 60 activates the front inflator 28 and the rear inflator 38 of the pedestrian protection airbag device 10 based on output signals from the collision detection sensor 62, the collision prediction sensor 64, and the pedestrian collision detection sensor 66. As a result, gas is supplied to the front side airbag 20 by the front inflator 28, and the front side airbag 20 is inflated and deployed outward and upward in the vehicle width direction from the side sill 40, and is disposed along the outer surface of the front side door 74. In addition, gas is supplied to the rear side airbag 30 by the rear inflator 38, and the rear side airbag 30 is inflated and deployed outward and upward in the vehicle width direction from the side sill 40, and is disposed along the outer surface of the rear side door 76. Furthermore, at this time, the actuator 54 is activated by the ECU 60. As a result, the front bag door holding portion 50 is broken, and the front bag door 42 opens to the expanded position. As a result, the upper end of the front side airbag 20 is disposed lower than the upper end of the rear side airbag 30, and a step 30A is formed between the front side airbag 20 and the rear side airbag 30.

[0036] As a result, when the pedestrian P falls from the rear end portion of the hood 78 of the vehicle V outward in the vehicle width direction of the front side door 74, the upper body of the pedestrian P is received from below by the front side airbag 20, and the head of the pedestrian P is received by the step portion 30A between the front side airbag 20 and the rear side airbag 30 (see FIG. 5 ). At this time, the lower bag portion 22 of the front side airbag 20 abuts against the road surface SR, and the front side airbag 20 is supported from below by the road surface SR. As a result, an upward reaction force acts on the front side airbag 20 from the road surface SR, and the pedestrian P can be well received by the front side airbag 20. Therefore, the pedestrian protection airbag device 10 of this embodiment can prevent the pedestrian P from falling from the rear end portion of the hood 78 outward in the vehicle width direction of the front side door 74 of the vehicle V from colliding with the road surface SR. In other words, the secondary collision of the pedestrian P can be reduced.

[0037] Further, a front bag door 42 and a rear bag door 44 are formed on the side sill 40. When the rear side airbag 30 is inflated and deployed, the rear bag door 44 opens to the open position, and the rear side airbag 30 is supported from below by the rear bag door 44 in the open position. Similarly, when the front side airbag 20 is inflated and deployed, the front bag door 42 opens outward in the vehicle width direction. Here, in the event of a collision with a pedestrian P, the front bag door 42 is disposed lower than the rear bag door 44, and the lower end of the front side airbag 20 is disposed lower than the lower end of the rear side airbag 30. As a result, by making the opening amount of the front bag door 42 larger than the opening amount of the rear bag door 44, the entire front side airbag 20 can be disposed offset below the rear side airbag 30, and a step portion 30A can be formed between the front side airbag 20 and the rear side airbag 30.

[0038] Further, a front bag door holding portion 50 connected to the front bag door 42 is provided inside the side sill 40, and the front bag door 42 is held in an open position by the front bag door holding portion 50. Further, a rear bag door holding portion 52 connected to the rear bag door 44 is provided inside the side sill 40, and the rear bag door 44 is held in an open position by the rear bag door holding portion 52. Furthermore, an actuator 54 is connected to the front bag door holding portion 50 for releasing the holding state of the front bag door 42 by the front bag door holding portion 50. When the actuator 54 is activated, the front bag door holding portion 50 breaks, and the holding state of the front bag door 42 by the front bag door holding portion 50 is released. As a result, in the event of a collision with a pedestrian P, by operating the actuator 54, the front side airbag 20 can be shifted downward relative to the rear side airbag 30, and a step portion 30A can be formed between the front side airbag 20 and the rear side airbag 30.

[0039] Furthermore, when the ECU 60 detects a collision between the pedestrian P and the vehicle V, it activates the actuator 54 to release the front bag door 42 from its holding state by the front bag door holding portion 50. On the other hand, when the ECU 60 detects a side collision between the vehicle V and a colliding object, it maintains the actuator 54 in a deactivated state. This allows the pedestrian protection airbag device 10 to be used both as an airbag device for pedestrian protection and as an airbag device for a side collision. That is, as described above, in the event of a collision between the pedestrian P and the vehicle V, the front side airbag 20 is positioned by shifting it downward, so that the front side airbag 20 can receive the pedestrian P from below, and the step portion 30A between the front side airbag 20 and the rear side airbag 30 can receive the pedestrian P from behind. On the other hand, in the event of a side collision of the vehicle V, the area of ​​the front side airbag 20 covering the front side door 74 can be increased to mitigate the impact with the colliding object.

[0040] Furthermore, a tether 26 is provided inside the front side airbag 20, connecting the lower end and the upper end of the front side airbag 20. When the actuator 54 is activated, a recessed portion 20A that is open toward the upper side of the vehicle is formed at the upper end of the front side airbag 20 by the tether 26. That is, when the vehicle V collides with a pedestrian P, the recessed portion 20A is formed at the upper end of the front side airbag 20. As a result, the shoulders and head of the pedestrian P who falls upward into the front side airbag 20 can be wrapped around and received by the recessed portion 20A. Furthermore, by forming the recessed portion 20A, the thickness of the upper bag portion 24 of the front side airbag 20 in the left-right direction can be increased. Therefore, a pedestrian who falls downward on the outer side of the vehicle V in the vehicle width direction can be well received by the upper bag portion 24 of the front side airbag 20.

[0041] Furthermore, when the actuator 54 is not activated, the upper end of the tether 26 is disposed adjacent to the outer side of the side of the vehicle V (front side door 74) in the vehicle width direction. This allows the front side airbag 20 to be disposed so as to be pulled toward the front side door 74 by the tether 26. Therefore, in the event of a side collision between the vehicle V and a colliding object, the front side airbag 20 can be disposed well along the outer surface of the front side door 74.

[0042] The front side airbag 20 is configured to include an upper bag portion 24 that forms the upper portion of the front side airbag 20 and a lower bag portion 22 that forms the lower portion of the front side airbag 20, and the internal pressure of the upper bag portion 24 is set lower than the internal pressure of the lower bag portion 22. As a result, the support performance of the front side airbag 20 is ensured by the lower bag portion 22, and the upper bag portion 24 can effectively absorb the collision energy of a pedestrian P that falls into the front side airbag 20 from above.

[0043] In the pedestrian protection airbag device 10 of this embodiment, the front bag door 42 is released from the state in which the front bag door holding portion 50 holds the front bag door 42, thereby positioning the upper end of the front side airbag 20 lower than the upper end of the rear side airbag 30 and forming the stepped portion 30A. Alternatively, the front bag door 42 may be held in the open position by the front bag door holding portion 50, and the position of the upper end of the front side airbag 20 may be set in advance to be lower than in this embodiment, thereby forming the stepped portion 30A between the front side airbag 20 and the rear side airbag 30.

[0044] Furthermore, in the pedestrian protection airbag device 10, the communication hole 22B (communication hole 32B) is formed in the lower bag portion 22 (lower bag portion 32) of the front side airbag 20 (rear side airbag 30) to communicate between the lower bag portion 22 (lower bag portion 32) and the upper bag portion 24 (upper bag portion 34), but the configuration for communicating between the lower bag portion 22 (lower bag portion 32) and the upper bag portion 24 (upper bag portion 34) is not limited to this. For example, the upper end of the lower bag portion 22 (lower bag portion 32) may be left open, and the upper end of the lower bag portion 22 (lower bag portion 32) and the lower end of the upper bag portion 24 (upper bag portion 34) may be connected by a plurality of tethers.

[0045] Furthermore, the pedestrian protection airbag device 10 is configured so that the front inflator 28 supplies gas to the front side airbag 20, and the rear inflator 38 supplies gas to the rear side airbag 30. In other words, the pedestrian protection airbag device 10 has two inflators. Alternatively, the pedestrian protection airbag device 10 may be configured with a single inflator, and gas may be supplied from that inflator to the front side airbag 20 and the rear side airbag 30. [Explanation of symbols]

[0046] 10 Pedestrian protection airbag device 20 Exterior front side airbags (exterior front side airbags) 20A recess 22 Lower bag section 24 Upper Bag Section 26 Tether 30 Exterior rear side airbags (exterior rear side airbags) 40 Side sill 42 Front bag door 44 Rear bag door 50 Front bag door holding portion (front holding portion) 52 Rear bag door holding portion (rear holding portion) 54 Actuator (hold release part) ECU (control unit) 60 Collision detection sensor 62 (collision detection unit) 64 Collision prediction sensor (collision detection section) 66 Pedestrian collision detection sensor (pedestrian collision detection section) P Pedestrian V vehicle

Claims

1. an exterior front side airbag provided in a front portion of a side sill of the vehicle and inflated and deployed along the side of the vehicle by receiving gas supply; an exterior rear side airbag provided at the rear of the vehicle's side sill and inflated and deployed along the side of the vehicle by receiving gas supply; Equipped with an upper end portion of the vehicle exterior front side airbag is disposed lower than an upper end portion of the vehicle exterior rear side airbag, The side sill is formed with a front bag door that is torn open when the vehicle exterior front side airbag is inflated and deployed, and opens outward in the vehicle width direction from a lower end of the side sill, and a rear bag door that is torn open when the vehicle exterior rear side airbag is inflated and deployed, and opens outward in the vehicle width direction from a lower end of the side sill, the rear bag door supports the exterior rear side airbag from below the vehicle; The front bag door is disposed lower than the rear bag door, and the vehicle exterior front side airbag is disposed lower than the vehicle exterior rear side airbag.

2. A front holding portion connected to the front bag door and holding the front bag door; a rear holding portion connected to the rear bag door and holding the rear bag door; a hold release portion that is connected to the front holding portion and that, when activated, releases the hold of the front bag door by the front holding portion and positions the front bag door lower than the rear bag door; 2. The pedestrian protection airbag device according to claim 1, comprising:

3. A pedestrian collision detection unit that detects a collision of a pedestrian with a vehicle; a collision detection unit that detects a side collision of a collision object with a vehicle; a control unit that controls the operation of the hold release unit, detects a collision of a pedestrian with a vehicle based on an output signal from the pedestrian collision detection unit, and detects a side collision with the vehicle based on an output signal from the collision detection unit; Equipped with When the control unit detects a collision of a pedestrian with a vehicle, the control unit activates the hold release unit, 3. The pedestrian protection airbag device according to claim 2, wherein when the control unit detects a side collision of a collision object, the control unit maintains the retention release unit in an inactivated state, and the front bag door supports the exterior front side airbag from below the vehicle.

4. A tether is provided inside the exterior front side airbag, connecting the lower end and upper end of the inflated and deployed exterior front side airbag, When the holding release portion is activated, a recessed portion that is opened toward the upper side of the vehicle by the tether is formed at an upper end portion of the exterior front side airbag, 4. The pedestrian protection airbag device according to claim 3, wherein when the retention release portion is not activated, the upper end of the tether is disposed adjacent to the outer side of the side of the vehicle in the vehicle width direction.

5. The vehicle exterior front side airbag is an upper bag portion that constitutes an upper portion of the exterior front side airbag; a lower bag portion constituting a lower portion of the vehicle exterior front side airbag; It is composed of 5. The pedestrian protection airbag device according to claim 1, wherein the internal pressure of the upper bag portion is lower than the internal pressure of the lower bag portion.

6. An exterior front side airbag provided in front of a vehicle's side sill and inflated and deployed along the side of the vehicle by receiving gas supply; an exterior rear side airbag provided at the rear of the vehicle's side sill and inflated and deployed along the side of the vehicle by receiving gas supply; Equipped with an upper end portion of the vehicle exterior front side airbag is disposed lower than an upper end portion of the vehicle exterior rear side airbag, The vehicle exterior front side airbag is configured to include an upper bag portion that forms an upper portion of the vehicle exterior front side airbag and a lower bag portion that forms a lower portion of the vehicle exterior front side airbag, and the internal pressure of the upper bag portion is lower than the internal pressure of the lower bag portion.

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