Airbag device

Abstract

To provide an air bag device which suppresses damage of a pedestrian or the like.SOLUTION: An air bag device comprises: a plurality of air bags which are developed from a vehicle body front part of a vehicle 1 to a front side; a collision determination part 120 which establishes, when collision possibility is a prescribed threshold value or more, a pre-crash determination; and an air bag development control part 110 which instructs inflators 111, 112 according to the pre-crash determination to develop the air bag. The plurality of air bags includes: a first air bag 30; and a second air bag 40 which is developed covering the front face part of the first air bag at the front side of the first air bag. The first air bag has a vent passage to discharge the development gas G according to pressing force from the second air bag.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an airbag device having an airbag that deploys from a front portion of a vehicle body of a vehicle such as an automobile to the outside of the vehicle. [Background technology]

[0002] 2. Description of the Related Art In vehicles such as automobiles, it has been proposed to use airbags that deploy to the outside of the vehicle to reduce injury to pedestrians and the like in the event of a collision. As a technology relating to such an external airbag device, for example, Patent Document 1 describes an airbag device for protecting pedestrians that is provided at the front end of a vehicle body, in which an airbag is divided into upper and lower parts by a bending resistance means and an air vent hole is provided in the upper area. It also describes a configuration in which a first airbag and a second airbag are sequentially arranged in the front-rear direction of the vehicle, and the second airbag protrudes upward behind the first airbag. Patent Document 2 describes a pedestrian protection airbag that deploys from the front end of a vehicle body and is a two-stage bag body with a front inflation section and a rear inflation section, with the capacity at the time of deployment being variable. Patent Document 3 describes an airbag device for protecting pedestrians, etc., which has a front bag body that deploys along the upper part of the front grille, an upper bag body that deploys on the top surface of the hood, and a lower bag body that deploys below the front bag body, and which controls the internal pressure of the expansion chamber with a vent mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-315599 A [Patent Document 2] JP 2007-269169 A [Patent Document 3] JP 2019-209824 A Summary of the Invention [Problem to be solved by the invention]

[0004] 2. Description of the Related Art There is a demand for reducing damage to pedestrians and cyclists (hereinafter referred to as pedestrians and the like) in the event of a collision between a vehicle and the pedestrians and the like. An object of the present invention is to provide an airbag device which reduces damage to pedestrians and the like. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the airbag device of the present invention is an airbag device including a plurality of airbags that deploy forward from a front portion of a vehicle body, a collision determination portion that establishes a pre-crash determination when a collision possibility is equal to or greater than a predetermined threshold, and an airbag deployment control portion that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the plurality of airbags and deploy the plurality of airbags, the plurality of airbags including a first airbag and a second airbag that deploys forward of the first airbag to cover a front portion of the first airbag, and the first airbag has a vent flow path that discharges the deployment gas in response to pressure from the second airbag. The second airbag is attached to the vehicle body via a mounting portion disposed below the first airbag. The second airbag is characterized in that, in response to the contraction of the first airbag, an upper end portion of the second airbag rotates relative to the vehicle body so as to retreat to above a front hood of the vehicle body. . According to this, when an object collides with the second airbag, the second airbag presses against the first airbag, and the first airbag contracts while discharging deployment gas, thereby effectively absorbing the collision energy. In addition, the internal pressure of the second airbag can be maintained at a higher pressure than the internal pressure of the first airbag, which improves the shape stability of the second airbag, stabilizes the contact condition with the object of collision, and improves the reproducibility of behavior after a collision. Also, According to this, in the event of a collision, as the first airbag contracts, the second airbag rotates in a direction in which the front portion rises, so that the object of collision can be raised and thrown upward on the vehicle body, thereby reducing the damage caused by the object. 。 Also, This allows the impact object to be guided so that it falls onto the upper surface of the front hood, and the impact energy is absorbed by the deformation of the front hood, thereby further reducing damage to the impact object.

[0007] In order to solve the above-mentioned problems, the airbag device of the present invention is an airbag device including a plurality of airbags that deploy forward from a front portion of a vehicle body, a collision determination portion that establishes a pre-crash determination when a collision possibility is equal to or greater than a predetermined threshold, and an airbag deployment control portion that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the plurality of airbags and deploy the plurality of airbags, the plurality of airbags including a first airbag and a second airbag that deploys forward of the first airbag to cover a front portion of the first airbag, and the first airbag has a vent flow path that discharges the deployment gas in response to pressure from the second airbag. The airbag device further includes a vent control unit that controls the opening degree of the vent passage, and the collision determination unit has a function of estimating a parameter that correlates with the energy of the collision object when the pre-crash determination is established, and the vent control unit varies the opening degree of the vent passage depending on the estimated parameter. Characterized by . According to this, when an object collides with the second airbag, the second airbag presses against the first airbag, and the first airbag contracts while discharging deployment gas, thereby effectively absorbing the collision energy. In addition, the internal pressure of the second airbag can be maintained at a higher pressure than the internal pressure of the first airbag, which improves the shape stability of the second airbag, stabilizes the contact condition with the object of collision, and improves the reproducibility of behavior after a collision. Also,According to this, by varying the opening degree of the vent passage depending on the weight of the impact object (for example, the size of a pedestrian) and the relative speed at the time of collision, the first airbag can be appropriately deflated regardless of variations in the energy of the impact object, thereby improving the accuracy of the second airbag's control of the behavior of the impact object.

[0008] In order to solve the above-mentioned problems, the airbag device of the present invention is an airbag device including a plurality of airbags that deploy forward from a front portion of a vehicle body, a collision determination portion that establishes a pre-crash determination when a collision possibility is equal to or greater than a predetermined threshold, and an airbag deployment control portion that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the plurality of airbags and deploy the plurality of airbags, the plurality of airbags including a first airbag and a second airbag that deploys forward of the first airbag to cover a front portion of the first airbag, and the first airbag has a vent flow path that discharges the deployment gas in response to pressure from the second airbag. The airbag device further includes a third airbag provided above the first airbag and a communication passage that connects the first airbag and the third airbag, and the third airbag is discharged when the first airbag is deflated. The above The first airbag is deployed upward by the deployment gas. Characterized by . According to this, when an object collides with the second airbag, the second airbag presses against the first airbag, and the first airbag contracts while discharging deployment gas, thereby effectively absorbing the collision energy. In addition, the internal pressure of the second airbag can be maintained at a higher pressure than the internal pressure of the first airbag, which improves the shape stability of the second airbag, stabilizes the contact condition with the object of collision, and improves the reproducibility of behavior after a collision. Also, With this, as the first airbag is pushed by the second airbag and contracts, the third airbag deploys so as to protrude upward and catches the object of impact that is thrown upward by the second airbag, thereby preventing the object of impact from directly colliding with the front hood of the vehicle body, etc. Effect of the Invention

[0009] As described above, according to the present invention, it is possible to provide an airbag device that reduces injury to pedestrians and the like. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a first embodiment of an airbag device to which the present invention is applied, in which a vehicle is viewed from above when an airbag is deployed. [Diagram 2] FIG. 2 is a view taken along the line II-II of FIG. [Diagram 3] 1 is a block diagram showing a schematic configuration of a system for controlling an airbag device according to a first embodiment. [Figure 4]5 is a flowchart illustrating an operation of the airbag device of the first embodiment during a collision. [Diagram 5] 1 is a diagram showing a schematic diagram of a state immediately after a vehicle having an airbag device of a first embodiment collides with a pedestrian. [Figure 6] FIG. 2 is a diagram showing a state in which a vehicle having the airbag device of the first embodiment collides with a pedestrian and the first airbag has completed contraction. [Figure 7] FIG. 11 is a diagram showing a schematic configuration of a second embodiment of an airbag device to which the present invention is applied, showing a state in which the front part of a vehicle is viewed from the side when the airbag is deployed. [Figure 8] FIG. 11 is a diagram showing a schematic view of a state after a vehicle having an airbag device according to a second embodiment collides with a pedestrian. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment Hereinafter, a first embodiment of an airbag device to which the present invention is applied will be described. The airbag device of the first embodiment is provided, for example, in the front of a vehicle such as a passenger car, and is intended to provide protection (reduction of damage) in the event of a collision with a human body such as a pedestrian or a bicycle rider. FIG. 1 is a diagram showing a schematic configuration of an airbag device according to a first embodiment, and shows a state in which a vehicle is viewed from above when an airbag is deployed. FIG. 2 is a view taken along the line II-II of FIG. The vehicle 1 has, for example, a so-called two-box vehicle shape having an engine compartment 20 that protrudes forward from a passenger compartment 10 .

[0012] The vehicle interior 10 is a portion having a space in which passengers and the like are accommodated. The engine compartment 20 is a portion having a space in which power train components such as an engine, a transmission, and in the case of an electric vehicle, a motor generator and its control devices are housed. The engine compartment 20 is provided with a front side frame 21, a bumper beam 22, a front bumper 23, a front hood 24, etc.

[0013] The front side frame 21 is a structural member that protrudes forward from a toe board (not shown), which is a partition wall provided at the front end of the passenger compartment 10, toward the front of the vehicle. The front side frame 21 functions as a base to which, for example, a power train, a cross member to which a front suspension is attached, and a strut housing that accommodates a strut of a MacPherson strut type front suspension are attached. The front side frame 21 is formed by assembling and welding members formed by press-molding steel plates, for example, so that its cross-sectional shape when viewed from the vehicle front-rear direction is a rectangular closed cross-section.

[0014] The bumper beam 22 is a structural member provided at the front of the vehicle body and extending in the vehicle width direction. The bumper beam 22 is formed into a beam shape with a closed cross section by, for example, assembling and welding members formed by press-molding steel plates, or by using an extruded aluminum alloy material. The bumper beam 22 has a middle portion connected to the front end portions of the left and right front side frames 21 . Both ends of the bumper beam 22 in the vehicle width direction protrude outward in the vehicle width direction relative to the front side frames 21. The bumper beam 22 is a load transmitting member that transmits the load received by an airbag 30 (described later) from a human body or object that it collides with, via the front side frames 21, to the rear side of the vehicle body.

[0015] The front bumper 23 is an exterior member provided at the front end of the vehicle body, and is configured by attaching a bumper face constituting a skin portion formed of, for example, a PP-based resin to the vehicle body with brackets or the like (not shown). The front portion of the front bumper 23 is curved so that the front side of the vehicle 1 is convex when the vehicle 1 is viewed from above. The bumper beam 22 is formed in an arc shape that is convex toward the front of the vehicle so as to follow the curvature of the front portion of the front bumper 23 when the vehicle 1 is viewed from above.

[0016] The front hood 24 is a lid-like body that is provided on the upper part of the engine compartment 20 in an openable and closable manner. The front hood 24 is formed by press-molding a panel made of, for example, mild steel or an aluminum alloy, and is provided with a frame-like stiffening structure on the rear (lower) side. The front hood 24 has a function of absorbing energy by plastic deformation when a pedestrian or the like that collides with the vehicle 1 hits the upper surface thereof, thereby suppressing injury.

[0017] The airbag device of the embodiment includes a first airbag 30 and a second airbag 40, which will be described below. The first airbag 30 and the second airbag 40 are formed into a bag shape by joining panels made of a base fabric such as nylon 66 fabric. The first airbag 30 is deployed and further inflated by the introduction of deployment gas generated by the first inflator 111 in response to the establishment of a pre-crash determination, which will be described later. The second airbag 40 is deployed and further inflated by the introduction of deployment gas generated by the second inflator 112 in response to the establishment of the pre-crash determination.

[0018] The first airbag 30 and the second airbag 40 are normally stored inside the front bumper 23 in a folded state (before the pre-crash determination is established). In the event of a collision, the first airbag 30 and the second airbag 40 break weak portions formed in the front bumper 23 and are projected forward of the vehicle, and are deployed forward relative to the front surface of the front bumper 23.

[0019] The first airbag 30 deploys, for example, from an upper portion of the front bumper 23 toward the front side of the vehicle. The second airbag 40 deploys, for example, from the lower part of the front bumper 23 toward the front side of the vehicle. The main body of the second airbag 40 is curved in an arc shape that protrudes toward the front side of the vehicle when viewed in the vehicle width direction. The second airbag 40 passes under the first airbag 30 and deploys forward of the first airbag 30 so as to cover the front portion of the first airbag 30. As shown in FIG. 2, an upper end portion 40a of the second airbag 40 is located at a higher position than an upper end portion of the first airbag 30 when the deployment of each airbag is complete and before a collision occurs.

[0020] The second airbag 40 is provided with a vent hole 41 . The vent hole 41 is closed during the deployment of the second airbag 40 until the deployment is completed, and is configured to rupture and open when the internal pressure of the second airbag 40 thereafter exceeds a predetermined value, thereby discharging the deployment gas inside the second airbag 40 (releasing it to the atmosphere). The operation of the first airbag 30 and the second airbag 40 in the event of a collision with a pedestrian P or the like will be described in detail later.

[0021] FIG. 3 is a block diagram that illustrates a schematic configuration of a system that controls the airbag device of the first embodiment. The system for controlling the airbag device comprises an airbag control unit 110, an environment recognition unit 120, and the like. Each of these units can be configured as a microcomputer having, for example, an information processing unit (processor) such as a CPU, a storage unit such as a RAM or a ROM, an input / output interface, and a bus connecting these. In addition, each unit is connected directly or via an in-vehicle LAN such as a CAN communication system, so that they can communicate with each other.

[0022] The airbag control unit 110 issues commands to and controls the first inflator 111, the second inflator 112, and the vent control valve 113 to inflate the first airbag 30 and the second airbag 40 and to control the state of deployment. The airbag control unit 110 functions as the airbag deployment control unit of the present invention. The first inflator 111 is a chemical (pyrotechnic) gas generating device that generates deployment gas G for deploying the first airbag 30 in response to a command from the airbag control unit 110. The second inflator 112 is a chemical (pyrotechnic) gas generating device that generates deployment gas G for deploying the second airbag 40 in response to a command from the airbag control unit 110.

[0023] The vent control valve 113 opens and closes a vent passage (not shown) for discharging the deployment gas G from within the first airbag 30 (for example, opening it to the atmosphere) in response to a command from the airbag control unit 110. The vent control valve 113 may, for example, be configured to include an electromagnetic valve. The vent control valve 113 has a function of varying the opening degree of the vent passage continuously or stepwise in response to a command from the airbag control unit 110 .

[0024] The airbag control unit 110 is provided with a pressure sensor 114 . The pressure sensor 114 has a function of detecting the pressure of the deployment gas G inside the first airbag 30 (internal pressure). The airbag control unit 110 can detect the input state of the load to the first airbag 30 based on the output of the pressure sensor 114.

[0025] The environment recognition unit 120 recognizes the environment around the vehicle based on the outputs of various sensors. The environment recognition unit 120 has a function of recognizing, for example, various objects such as pedestrians, cyclists, and other human bodies around the vehicle 1 (host vehicle), other vehicles, buildings, trees, and terrain, road shapes (lane shapes), and the like. The environment recognition unit 120 functions as a collision judgment section that makes a pre-crash judgment when a collision with a human body, such as a pedestrian, a cyclist, or a motorcycle rider, or an object other than a human body, such as another vehicle, is unavoidable (when the possibility of collision is greater than or equal to a predetermined level). The environment recognition unit 120 is connected to a stereo camera device 121, a millimeter wave radar device 122, a laser scanner device 123, and the like.

[0026] The stereo camera device 121 has a pair of cameras arranged at a predetermined distance (baseline length) apart, and has the function of recognizing, for example, human bodies such as pedestrians and cyclists, and objects such as other vehicles and buildings, and also detecting the relative positions of human bodies, objects, etc. with respect to the vehicle 1 by known stereo image processing. The stereo camera device 121 has a function of recognizing the attributes of a subject by, for example, pattern recognition of a captured image. For example, in the case of a human body such as a pedestrian, the system has a function for recognizing the physique, estimated weight, posture, and the like.

[0027] The millimeter wave radar device 122 is a radar device that uses radio waves in a frequency band of, for example, 30 to 300 GHz, and has the function of detecting the presence or absence of a human body, object, etc., and the relative position of the human body, object, etc. with respect to the vehicle 1. The laser scanner device (LIDAR) 123 has the function of scanning the surroundings of the vehicle 1, for example by emitting pulsed near-infrared laser light, and detecting the presence or absence of human bodies, objects, etc., and the relative positions and shapes of human bodies, objects, etc. in relation to the vehicle 1 based on the presence or absence of reflected light and the time difference until the reflected light returns. The environmental recognition unit 120 is capable of recognizing the type of collision with a human body, object, etc. (e.g., the velocity vector of the collision object relative to vehicle 1, the collision position relative to vehicle 1, etc.) and the attributes of the collision object (the physique of the human body, the model of the other vehicle, etc.) when a collision with a human body such as a pedestrian or an object such as another vehicle is unavoidable (when a pre-crash judgment is established).

[0028] Next, the operation of the airbag device of the first embodiment will be described. FIG. 4 is a flowchart illustrating the operation of the airbag device of the first embodiment during a collision. Each step will be explained in order below.

[0029] <Step S01: Pre-crash determination> The environment recognition unit 120 uses known pre-crash judgment logic to estimate the possibility of a collision between the vehicle 1 and a collision object approaching from the front of the vehicle 1, such as a pedestrian or a cyclist, and determines whether the estimated possibility is equal to or exceeds a preset threshold. If the possibility of a collision occurring is equal to or greater than the threshold, it is determined that a collision is unavoidable, a pre-crash determination is established, and the process proceeds to step S02; otherwise, the series of processes ends.

[0030] <Step S02: Airbag deployment begins / vent control valve close> The airbag control unit 110 issues commands to the first inflator 111 and the second inflator 112 to generate deployment gas G and introduce it into the first airbag 30 and the second airbag 40, thereby starting the deployment of the first airbag 30 and the second airbag 40. At this time, the airbag control unit 110 closes the vent control valve 113 in order to quickly deploy the first airbag 30. Then, proceed to step S03.

[0031] <Step S03: Determining whether airbag deployment is complete> The airbag control unit 110 determines whether or not the first airbag 30 has been deployed to a predetermined volume based on the output of the pressure sensor 114 and the like. If it is determined that the first airbag 30 has been deployed to the predetermined volume, the deployment of the first airbag 30 is deemed to be complete and the process proceeds to step S04; otherwise, step S03 is repeated.

[0032] <Step S04: Estimation of energy of colliding object> The environment recognition unit 120 estimates parameters that correlate with the collision energy of an object colliding with the vehicle 1, based on the outputs of various sensors such as the stereo camera device 121. As a parameter correlated with the collision energy, for example, when the collided object is a human body such as a pedestrian or a cyclist, an approximate value of the body size (weight) is estimated. Furthermore, the relative speed of the collision object with respect to the vehicle 1 in the longitudinal direction of the vehicle can also be used as a parameter correlated with the collision energy. Then, proceed to step S05.

[0033] <Step S05: Setting the vent control valve opening> The airbag control unit 110 opens the vent control valve 113 and sets the opening degree of the vent control valve 113 in accordance with the magnitude of the parameter correlated with the collision energy of the object of collision determined in step S04. For example, as the size of the impact object (pedestrian, etc.) decreases, or as the relative speed between the impact object and the vehicle 1 decreases, the opening of the vent control valve 113 can be increased, thereby promoting the contraction of the first airbag 30 during a collision even when the collision energy is small. Then, the series of processes ends.

[0034] Hereinafter, a state transition during a pedestrian collision in the airbag device of the first embodiment, as well as functions and effects will be described. First, in response to the establishment of a pre-crash determination with respect to a pedestrian or the like, the first airbag 30 and the second airbag 40 are deployed in the states shown in Figs. After deployment to this state, the vent control valve 113 is opened to the opening degree set in step S04. At this time, the internal pressure of the first airbag 30 is set to be lower than the internal pressure of the second airbag 40 .

[0035] FIG. 5 is a schematic diagram showing a state immediately after a vehicle having the airbag device of the first embodiment collides with a pedestrian. When the pedestrian P collides with the front portion of the second airbag 40, the second airbag 40 moves backward with respect to the vehicle body and presses the front portion of the first airbag 30. The first airbag 30, which is pressed by the second airbag 40, discharges the deployment gas G from the vent control valve 113 and contracts while absorbing the collision energy of the pedestrian P. As the first airbag 30 contracts, the second airbag 40 rotates toward the rear of the vehicle around the vicinity of the portion where the second airbag 40 is attached to the vehicle body (the lower portion of the front bumper 23). This rotation causes the front portion of the second airbag 40 to rise. At this time, the pedestrian P in contact with the front portion of the second airbag 40 rises while rotating so that the head is displaced toward the rear of the vehicle relative to the legs.

[0036] FIG. 6 is a diagram showing a state in which a vehicle having the airbag device of the first embodiment collides with a pedestrian and the first airbag has completed contraction. At this time, the upper end portion of the second airbag 40 is in contact with or adjacent to the surface portion of the front hood 24. The pedestrian P is thrown upwardly above the front hood 24. The second airbag 40 is sandwiched between the pedestrian P and the front hood 24 and compressed, causing the internal pressure to increase. When the internal pressure of the second airbag 40 increases to or above a predetermined level, the vent hole 41 breaks and opens, and the deployment gas G within the second airbag 40 is released (opened to the atmosphere). As a result, the second airbag 40 contracts and further absorbs the collision energy of the pedestrian P. After the second airbag 40 has deflated, the remaining collision energy of the pedestrian P is absorbed by the plastic deformation of the front hood 24 or the like.

[0037] As described above, according to the first embodiment, the following effects can be obtained. (1) When a pedestrian P or the like collides with the second airbag 40, the second airbag 40 presses against the first airbag 30, and the first airbag 30 contracts while discharging the deployment gas G, thereby effectively absorbing the collision energy. In addition, the internal pressure of the second airbag 40 can be maintained at a higher pressure than the internal pressure of the first airbag 30, thereby improving the shape stability of the second airbag 40, stabilizing the contact condition with a pedestrian P, etc., and improving the reproducibility of behavior after a collision. (2) Since the second airbag 40 is attached to the vehicle body via a mounting portion located below the first airbag 30, when a collision occurs, the second airbag 40 rotates in a direction in which the front portion rises in response to the contraction of the first airbag 30, thereby lifting a pedestrian P, etc., and bouncing them upward toward the upper side of the vehicle body. (3) In response to the contraction of the first airbag 30, the second airbag 40 rotates relative to the vehicle body so that the upper end 40a retreats to above the front hood 24, thereby guiding the pedestrian P, etc. to fall onto the upper surface of the front hood 24. The deformation of the front hood 24 absorbs the collision energy, thereby further reducing injury to the pedestrian P, etc. (4) By varying the opening degree of the vent control valve 113 depending on the size of the pedestrian P, etc. and the relative speed at the time of collision, the first airbag 30 can be appropriately deflated regardless of the variation in the collision energy of the pedestrian P, etc., and the accuracy of the behavior control of the pedestrian P, etc. by the rotation of the second airbag 40 can be improved.

[0038] <Second embodiment> Next, a second embodiment of the airbag device to which the present invention is applied will be described. In the second embodiment, the same reference numerals are used for the parts common to the first embodiment described above, and the description will be omitted, and the differences will be mainly described. FIG. 7 is a diagram showing a schematic configuration of an airbag device according to a second embodiment of the present invention, and shows a state in which the front part of a vehicle is viewed from the side when the airbag is deployed. In the second embodiment, a third airbag 50 is provided above the first airbag 30. The third airbag 50 is separated from the first airbag 30 by a partition wall 31 provided on the upper part of the first airbag 30 . The third airbag 50 receives the deployment gas G from the first airbag 30 through a vent hole 32 provided in the partition wall 31 .

[0039] The vent hole 32 is initially closed, and when the internal pressure difference between the first airbag 30 and the third airbag 50 reaches or exceeds a predetermined pressure, the weakened portion breaks and the vent hole 32 is opened. The vent hole 32 is maintained in a closed state when the first airbag 30 is deployed by the first inflator 111, and thereafter, when a collision with a pedestrian P or the like occurs and the first airbag 30 is pressed against the second airbag 40, the vent hole 32 is set to transition to an open state in response to an increase in the internal pressure of the first airbag 30.

[0040] FIG. 8 is a schematic diagram showing a state after a vehicle having an airbag device according to the second embodiment collides with a pedestrian. When the second airbag 40 collides with the pedestrian P and moves backward, it presses the first airbag 30, causing the internal pressure of the first airbag 30 to increase and the vent hole 32 to open. As a result, the deployment gas G flows from the first airbag 30 to the third airbag 50. As the deployment gas G is introduced, the third airbag 50 deploys so as to protrude upward from an upper portion of the first airbag 30. After deployment, the upper end of the third airbag 50 protrudes upward beyond the upper end of the second airbag 40. The third airbag 50 has a function of receiving a pedestrian P or the like thrown upward by the second airbag 40 toward the upper side of the front hood 24 and absorbing the collision energy. According to the second embodiment described above, as the first airbag 30 is pushed by the second airbag 40 and contracts, the third airbag 50 deploys so as to protrude upward, and receives the pedestrian P, etc., who is thrown upward by the second airbag 40, thereby preventing the pedestrian P, etc., from directly colliding with the front hood 24, etc.

[0041] (Modification) The present invention is not limited to the above-described embodiments, and various modifications and variations are possible, which are also within the technical scope of the present invention. (1) The configurations of the airbag device and the vehicle are not limited to the above-described embodiments and may be modified as appropriate. For example, the structure, shape, material, manufacturing method, arrangement, and number of each member and part that constitutes these, as well as the specific content of various controls, are not limited to those in the respective embodiments and can be changed as appropriate. (2) The method of performing the pre-crash determination and the method of determining the type of collision are not limited to the methods described in the respective embodiments and may be modified as appropriate. (3) The shapes and arrangements of the first to third airbags are not limited to those in the above-described embodiments and may be modified as appropriate. In addition to these airbags, additional airbags may be provided. Furthermore, there are no particular limitations on the arrangement of the vent holes, vent control valves, etc., or on the conditions for transition between the open state and the closed state. [Explanation of symbols]

[0042] 1 car 10 compartments 20 Engine compartment 21 Front side frame 22 Bumper beam 23 Front bumper 24 Front hood 30 First airbag 31 Partition wall 32 Vent hole 40 Second airbag 40a Upper end 41 Vent hole 50 3rd airbag 110 Airbag control unit 111 First inflator 112 Second inflator 113 Vent control valve 114 Pressure sensor 120 Environmental Awareness Unit 121 Stereo camera device 122 Millimeter wave radar device 123 Laser scanner device G Gas for deployment P Pedestrian

Claims

1. A vehicle comprising: a plurality of airbags that deploy forward from a front portion of a vehicle body; a collision determination unit that establishes a pre-crash determination when the possibility of a collision is equal to or greater than a predetermined threshold; an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the plurality of airbags and deploy the plurality of airbags; An airbag device comprising: the plurality of airbags include a first airbag and a second airbag that is deployed forward of the first airbag to cover a front portion of the first airbag, the first airbag has a vent passage for discharging the deployment gas in response to pressure from the second airbag, the second airbag is attached to the vehicle body via a mounting portion disposed below the first airbag, The second airbag rotates relative to the vehicle body so that an upper end portion of the second airbag moves back to above a front hood of the vehicle body in response to the contraction of the first airbag. An airbag device comprising:

2. A plurality of airbags that deploy forward from a front portion of a vehicle body; a collision determination unit that establishes a pre-crash determination when the possibility of a collision is equal to or greater than a predetermined threshold; an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the plurality of airbags and deploy the plurality of airbags; An airbag device comprising: the plurality of airbags include a first airbag and a second airbag that is deployed forward of the first airbag to cover a front portion of the first airbag, the first airbag has a vent passage for discharging the deployment gas in response to pressure from the second airbag, The airbag device further includes a vent control unit that controls an opening degree of the vent passage, the collision determination unit has a function of estimating a parameter correlated with the energy of a collision object when the pre-crash determination is established, The vent control unit varies an opening degree of the vent passage in accordance with the estimated parameter. An airbag device comprising:

3. A plurality of airbags that deploy forward from a front portion of a vehicle body; a collision determination unit that establishes a pre-crash determination when the possibility of a collision is equal to or greater than a predetermined threshold; an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the plurality of airbags and deploy the plurality of airbags; An airbag device comprising: the plurality of airbags include a first airbag and a second airbag that is deployed forward of the first airbag to cover a front portion of the first airbag, the first airbag has a vent passage for discharging the deployment gas in response to pressure from the second airbag, the airbag device further includes a third airbag provided above the first airbag, and a communication passage that communicates the first airbag with the third airbag, The third airbag is deployed above the first airbag by the deployment gas discharged when the first airbag is deflated. An airbag device comprising:

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