Airbag device

Abstract

To provide an air bag device which can mitigate damage when colliding with an obstacle.SOLUTION: An air bag device comprises: a plurality of air bags 30C, 30R, 30L which are arranged at a vehicle body front part in a vehicle width direction; a pre-crash determination part 120; an air bag development control part 110 which develops the air bags according to the establishment of the pre-crash determination; and air bag rotation control part in which the air bags 30R, 30L at side end parts are rotatably supported to be shaken out outward and switchable between a rotation restriction state and a rotation allowable state. The air bag rotation control part performs an end side air bag rotation control which lets an air bag arranged at the side where crashing against an obstacle in the vehicle width direction be in the rotation allowable state according to precursory phenomenon of off-set collision with the obstacle or occurrence thereof.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] As a technology relating to an airbag device that deploys on the outside of a vehicle such as an automobile, for example, Patent Document 1 describes an airbag system equipped with multiple external airbags that reduces the impact on the vehicle in the event of a frontal collision. Patent document 2 describes a bag-like structure that holds gas or the like and is provided on the outer surface of a vehicle body, and is configured so that during a collision, the volume of a part of the bag-like structure changes and a fixed portion of the bag-like structure detaches. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-526593 [Patent Document 2] JP 2012-101657 A Summary of the Invention [Problem to be solved by the invention]

[0004] 2. Description of the Related Art Generally, vehicles such as automobiles are designed so that, in the event of a frontal collision, the front structure of the vehicle body is crushed to absorb the collision energy. As described in Patent Document 1 and other documents, even when an airbag is deployed outside the vehicle, the load received by the airbag is usually transferred to the vehicle body structural members, and the collision energy that cannot be absorbed by the airbag is absorbed by the collapse of the vehicle body structure. Such energy absorption is often assumed to occur when the colliding vehicle has a vehicle weight equivalent to that of the subject vehicle and the collision occurs at a relative speed of, for example, approximately several tens of kilometers per hour. However, in reality, there is a possibility of a collision with a vehicle larger than the vehicle itself, a collision with a vehicle traveling faster than the assumed vehicle speed, or a multiple collision in which multiple vehicles collide in succession, and it is also possible that sufficient energy absorption will not be possible due to the collapse of the vehicle body structure alone. For this reason, there is a demand for reducing damage during a collision without relying excessively on the vehicle body structure. In view of the above-mentioned problems, an object of the present invention is to provide an airbag device capable of reducing damage caused by a collision with an object. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the airbag device of the present invention is an airbag device comprising a plurality of airbags arranged in the vehicle width direction and deployed forward from the front of the vehicle body, a pre-crash judgment unit that establishes a pre-crash judgment when the possibility of a collision with an object is equal to or higher than a predetermined value, an airbag deployment control unit that deploys the airbags in response to the establishment of the pre-crash judgment, and a collision type discrimination unit that discriminates the collision type with the object, wherein the airbag arranged at an end in the vehicle width direction is supported so as to be rotatable in a direction in which a front end is swung outward in the vehicle width direction, and has an airbag rotation control unit that can switch between a rotation restricted state in which the rotation is restricted and a rotation permitted state in which the rotation is permitted, and the airbag rotation control unit performs end airbag rotation control to set the airbag at the end on the side that will experience the offset collision in the vehicle width direction to a rotation permitted state when the collision type is an offset collision. According to this, during an offset collision, the airbag at the end on the impact side in the vehicle width direction is rotated in a direction such that the front end is swung outward in the vehicle width direction, so that with the surface of the airbag in close contact with the object, the object is induced by the rotation of the airbag to be displaced outward in the vehicle width direction relative to the vehicle itself. This converts the collision energy of the object into kinetic energy that moves the object away from the vehicle, reducing the amount of collision energy absorbed by the body of the vehicle, and suppressing damage such as damage to the passenger compartment.

[0006] In the present invention, an airbag deflation control unit may be provided which individually controls the deflation of the plurality of airbags, and the airbag deflation control unit may be configured to deflate the airbag to be rotated prior to the end airbag rotation control, and to perform end airbag deflation control which maintains the deployment of the other airbags. According to this, the airbag is first contracted a predetermined amount to absorb a portion of the collision energy, and then the airbag is rotated to convert the remaining collision energy into kinetic energy, thereby reducing the energy input to the vehicle body structure and suppressing damage while achieving the above-mentioned effects.

[0007] In the present invention, the airbag deflation control unit may be configured to suppress the deflation of the airbag after the deflated airbag has deflated over a predetermined target stroke. According to this, after a predetermined amount of energy has been absorbed by the contraction of the airbag, the contraction of the airbag is suppressed to generate sufficient resistance, thereby making it possible to more effectively obtain the above-mentioned effects.

[0008] In the present invention, the airbag that is put into a rotation-permitted state by the airbag rotation control is attached to the vehicle body by a plurality of support points that are distributed in the vehicle width direction, and the airbag rotation control unit can be configured to put the airbag into a rotation-permitted state by disabling the support points on the inside in the vehicle width direction. According to this, the airbag can be transitioned from the rotation restricted state to the rotation permitted state with a simple configuration.

[0009] In the present invention, the vehicle can be configured to include a yaw moment generating device that generates a yaw moment in the vehicle body, and when the airbag rotation control unit places the airbag at one end in the vehicle width direction in the rotation-permitting state, the yaw moment generating device can generate a yaw moment toward the other side in the vehicle width direction. According to this, by performing the end airbag rotation control and generating a yaw moment that turns the vehicle in a direction to avoid the object, it is possible to more effectively move the host vehicle away from the object. Effect of the Invention

[0010] As described above, according to the present invention, it is possible to provide an airbag device capable of reducing damage caused by a collision with an object. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing a schematic configuration of an embodiment of an airbag device to which the present invention is applied; [Diagram 2] 1 is a block diagram showing a schematic configuration of a system for controlling an airbag device according to an embodiment; [Diagram 3] 5 is a flowchart illustrating an operation of the airbag device of the embodiment during a collision. [Figure 4] 1 is a diagram illustrating an example of a state after a vehicle having an airbag device according to an embodiment collides with another vehicle; [Diagram 5] 11A and 11B are diagrams illustrating another example of a state after a vehicle having the airbag device of the embodiment collides with another vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of an airbag device to which the present invention is applied will be described. The airbag device of the embodiment is provided in the front part of a vehicle body of an automobile such as a passenger car, for example, and aims to reduce damage when the automobile collides with an object such as another vehicle. FIG. 1 is a diagram showing a schematic configuration of an airbag device according to an embodiment. FIG. 1 shows a vehicle having an airbag device according to an embodiment as viewed from above. 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 .

[0013] 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, etc.

[0014] 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 houses the upper part of 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.

[0015] 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 the central airbag 30C, the right airbag 30R, and the left airbag 30L (described later) from an object collided with, via the front side frames 21, to the rear side of the vehicle body.

[0016] 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.

[0017] The airbag device of this embodiment includes a center airbag 30C, a right airbag 30R, and a left airbag 30L. Each airbag is formed into a bag shape by joining panels made of a base fabric such as nylon 66 fabric, and is deployed by blowing in deployment gas generated by an inflator 111 in response to the establishment of a pre-crash determination.

[0018] The central airbag 30C is provided in the center of the vehicle body in the vehicle width direction. The right airbag 30R is provided adjacent to the central airbag 30C on the right side in the vehicle width direction. The left airbag 30L is provided adjacent to the central airbag 30C on the left side in the vehicle width direction. The central airbag 30C, the right airbag 30R, and the left airbag 30L are attached to the bumper beam 22 in a folded state and are housed inside the front bumper 23 under normal circumstances (before the pre-crash determination is established). In the event of a collision, each airbag breaks a weakened portion formed in the front bumper 23 and is deployed toward the front side of the vehicle, and deploys forward relative to the front surface of the front bumper 23.

[0019] The right airbag 30R and the left airbag 30L are attached to the vehicle body at an inner attachment portion 31 and an outer attachment portion 32. The inner attachment portion 31 is provided near the inner end portion in the vehicle width direction of the rear end portion of the right airbag 30R and the left airbag 30L. The outer attachment portions 32 are provided near the outer ends of the rear ends of the right airbag 30R and the left airbag 30L in the vehicle width direction. The outer attachment portion 32 supports the right airbag 30R and the left airbag 30L so as to be rotatable (swingable) about an axis along the vertical direction. The inner mounting portion 31 is deactivated (disengaged) by a mounting portion disabling actuator 114 (described later) in response to a command from the airbag control unit 110, making it possible to detach the right airbag 30R and the left airbag 30L from the bumper beam 22 and the front bumper 23. The inner mounting portion 31 is a support point that supports the right airbag 30R and the left airbag 30L to at least one of the bumper beam 22 and the front bumper 23, and is deactivated when its supported state is changed to an unsupported state by the mounting portion disabling actuator 114 (for example, the inner mounting portion 31 is configured as an engagement portion that is movable in the vertical direction by the mounting portion disabling actuator 114 and engages with the bumper beam 22 or the front bumper 23 when its vertical position is at a predetermined position, and is driven by the mounting portion disabling actuator 114 to a position other than the predetermined position, thereby releasing the engagement with the bumper beam 22 or the front bumper 23). When the inner mounting portion 31 is disabled, the right airbag 30R and the left airbag 30L change from a rotation restricted state in which rotation is restricted to a rotation permitted state in which the front end portions can be rotated around a vertical axis passing through the outer mounting portion 32 so as to swing outward in the vehicle width direction.

[0020] FIG. 2 is a block diagram showing a schematic configuration of a system for controlling the airbag device of the embodiment. The system for controlling the airbag device is configured to include an airbag control unit 110, an environment recognition unit 120, a behavior control unit 130, 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.

[0021] The airbag control unit 110 issues commands to an inflator 111 and a vent control valve 112, and controls these to inflate the right airbag 30R, the central airbag 30C, and the left airbag 30L, and to control the state of their deployment. The airbag control unit 110 functions as the airbag deployment control unit of the present invention. Additionally, the airbag control unit 110 cooperates with the vent control valve 112 to function as the airbag deflation control unit of the present invention. The airbag control unit 110 also has a function of controlling a mounting portion disabling actuator 114 that disables the inner mounting portions 31 of the right airbag 30R and the left airbag 30L. This point will be explained in more detail later.

[0022] The inflator 111 is a chemical (pyrotechnic) gas generating device that generates deployment gas for deploying each airbag in response to a command from the airbag control unit 110. The inflators 111 are provided independently for the right airbag 30R, the central airbag 30C, and the left airbag 30L, respectively, and are capable of individually controlling whether or not the right airbag 30R, the central airbag 30C, and the left airbag 30L are to be deployed, and the timing at which the deployment begins.

[0023] The vent control valves 112 are provided in the right airbag 30R, the central airbag 30C, and the left airbag 30L, respectively, and serve to open and close vent flow paths (not shown) that exhaust gas from within each airbag (eg, open to the atmosphere). The vent control valve 112 has a function of independently opening and closing the vent flow paths of the right airbag 30R, the central airbag 30C, and the left airbag 30L in response to a command from the airbag control unit 110, for example. The vent control valve 112 may, for example, comprise a solenoid valve.

[0024] The airbag control unit 110 is provided with a pressure sensor 113 . The pressure sensor 113 has a function of detecting the internal pressure of each of the right airbag 30R, the central airbag 30C, and the left airbag 30L. The airbag control unit 110 is capable of determining, based on the output of the pressure sensor 113, a state of load input from another vehicle or the like to the right airbag 30R, the central airbag 30C, and the left airbag 30L.

[0025] The mounting portion disabling actuator 114 disables the inner mounting portions 31 of the right airbag 30R and the left airbag 30L in response to a command from the airbag control unit 110. When the inner mounting portion 31 is disabled, the areas around the inner mounting portion 31 of the right airbag 30R and the left airbag 30L are separated (fall off) from the front bumper 23. Various actuators such as a chemical type (explosive type) or an electromagnetic type can be used as the attachment portion disabling actuator 114. The airbag control unit 110 and the attachment portion disabling actuator 114 work together to function as the airbag rotation control unit of the present invention.

[0026] 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 other vehicles, pedestrians, buildings, trees, and terrain around the vehicle 1 (host vehicle), as well as road shapes (lane shapes), and the like. The environment recognition unit 120 functions as a pre-crash determination section that establishes a pre-crash determination when a collision with an object such as another vehicle is unavoidable (when the possibility of a collision is equal to or greater than 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.

[0027] The stereo camera device 121 has a pair of cameras arranged at a predetermined distance (baseline length) apart, and has the function of recognizing objects such as other vehicles, pedestrians, and cyclists, and detecting the relative position of the objects with respect to the vehicle 1 by known stereo image processing. The stereo camera device 121 has a function of recognizing the attributes of an object by pattern recognition of a captured image, etc. For example, when the object is another vehicle, the stereo camera device 121 has a function of recognizing the size of the other vehicle (whether it is a large vehicle such as a truck, bus, or large SUV that is significantly heavier than the vehicle 1, etc.). 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 a function of detecting the presence or absence of an object and the relative position of the object with respect to the vehicle 1.

[0028] The laser scanner device (LIDAR) 123 has a function of, for example, scanning the periphery of the vehicle 1 by emitting pulsed near-infrared laser light, and detecting the presence or absence of an object, the relative position of the object with respect to the vehicle 1, the shape of the object, etc., based on the presence or absence of reflected light and the time difference until the reflected light returns. The environment recognition unit 120 is capable of recognizing the collision mode with the object (e.g., the object's velocity vector relative to vehicle 1, the collision position relative to vehicle 1, etc.) and the attributes of the object (e.g., in the case of a vehicle, the type, shape, size, etc.) when a collision with an object such as another vehicle is unavoidable (when a pre-crash judgment is made). The environment recognition unit 120 has a function as a collision type discrimination unit.

[0029] The behavior control unit 130 has a function of controlling the braking force of each wheel in a hydraulic service brake device (not shown) to perform vehicle behavior control for suppressing oversteer or understeer of the vehicle, anti-lock brake control, etc. The behavior control unit 130 is connected to a vehicle speed sensor 131, an acceleration sensor 132, a yaw rate sensor 133, and the like. The vehicle speed sensor 131 is provided, for example, adjacent to a hub bearing portion that rotatably supports a wheel, and outputs a vehicle speed signal having a frequency proportional to the rotation speed of the wheel. The behavior control unit 130 has a function of calculating the traveling speed (vehicle speed) of the vehicle based on the vehicle speed signal. The acceleration sensor 132 detects the longitudinal acceleration and lateral acceleration acting on the vehicle body. The yaw rate sensor 133 detects the yaw rate of the vehicle body. In addition, the behavior control unit 130 functions as a yaw moment generating device that generates a braking force difference between the left and right wheels when executing the end airbag rotation control described later, thereby generating a yaw moment that turns the vehicle in the opposite direction to the collision side (the side to avoid other vehicle V).

[0030] Next, the operation of the airbag device of the embodiment will be described. FIG. 3 is a flowchart illustrating the operation of the airbag device of the embodiment during a collision. Each step will be explained in order below.

[0031] <Step S01: Pre-crash determination result determination> The environment recognition unit 120 uses known pre-crash judgment logic to estimate the possibility of a collision with another vehicle (an example of an object as referred to in the present invention) approaching from the front of the vehicle 1, and determines whether the estimated possibility is equal to or exceeds a preset threshold value. 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 is ended (returned).

[0032] <Step S02: Deploy all airbags> The airbag control unit 110 issues an activation command to the inflator 111 to inflate the right airbag 30R, the central airbag 30C, and the left airbag 30L. At this time, the vent control valve 112 closes the vent passage of each airbag. Then, proceed to step S03.

[0033] <Step S03: Collision type recognition> The airbag control unit 110 recognizes the manner in which another vehicle hits the vehicle 1. The type of collision can be recognized based on the internal pressure of each airbag detected by the pressure sensor 113, for example. For example, when the internal pressure of a part of the airbags increases more than the internal pressure of the other airbags, it can be recognized that another vehicle is in contact with only that airbag. In particular, when the internal pressure increase of either the right airbag 30R or the left airbag 30L is greater than the internal pressure increase of the central airbag 30C and there is no significant change in the internal pressure of the other of the right airbag 30R or the left airbag 30L, it can be recognized as an offset collision in which the other vehicle mainly hits either the right airbag 30R or the left airbag 30L. Further, instead of using the pressure sensor 113 to recognize the collision type, the airbag control unit 110 may recognize the collision type based on the output of the environment recognition unit 120 or the behavior control unit 130. For example, an offset collision or the like may be determined based on the results of monitoring the relative position of another vehicle with respect to the vehicle 1 before and after the collision using the stereo camera device 121 or the like. Further, an offset collision or the like may be determined based on the vehicle behavior detected by the acceleration sensor 132 and the yaw rate sensor 133. Then, proceed to step S04.

[0034] <Step S04: Offset collision determination> The airbag control unit 110 determines whether the collision type recognized in step S03 is a specific offset collision in which the collision damage can be mitigated by end airbag rotation control, which will be described later. For example, when another vehicle collides with vehicle 1 in a state where the overlap ratio with respect to vehicle 1 is, for example, equal to or less than a predetermined value, the other vehicle is in contact with the central airbag 30 and either the right airbag 30R or the left airbag 30L, and the velocity vector of the other vehicle relative to the vehicle itself is within a predetermined angle range, it can be determined that a specific offset collision has occurred. Such a determination can be made based on, for example, the output of the pressure sensor 113, the environment recognition unit 120, and the like. In this specification and the claims, the offset collision also includes an oblique offset collision (so-called oblique collision) in which an object such as another vehicle collides in a direction inclined with respect to the longitudinal direction of the vehicle itself. If it is determined that the collision is a specific offset collision, the process proceeds to step S06, and in other cases (for example, a full-lap collision or an offset collision in which the overlap rate is outside a predetermined range) the process proceeds to step S05.

[0035] <Step S05: Open all airbag vent control valves> The airbag control unit 110 commands the vent control valve 112 to open the vent passages in all of the right airbag 30R, center airbag 30C, and left airbag 30L. As a result, in the event of a full-wrap collision, for example, all of the airbags can be deflated and contracted in response to the collision, thereby absorbing the maximum amount of energy that can be achieved by the airbag device. Such airbag deflation can be suppressed, for example, by closing the vent control valve 112 after the airbag has deflated over a preset, predetermined stroke (which here refers to the amount of deflation in the front-rear direction). Also, the vent control valve 112 may be configured to be held open after a collision. Then, the series of processes ends (returns).

[0036] <Step S06: Opening the collision side airbag vent control valve> The airbag control unit 110 issues a command to the vent control valve 112 to open the vent passage of one of the right airbag 30R and the left airbag 30L on the side where a collision with another vehicle has occurred, thereby performing end airbag contraction control to exhaust gas from within the airbag and contract it in the forward and backward directions. At this time, the vent passages of the other airbags are maintained in a closed state, thereby maintaining the deployed state of the other airbags. Then, proceed to step S07.

[0037] <Step S07: Determine whether or not the target stroke has been reached> The airbag control unit 110 determines whether the airbag, which has opened the vent passage in step S06, has contracted while venting gas due to input from another vehicle, and whether the dimension in the front-rear direction has decreased by a predetermined target stroke (shock absorption stroke). The target stroke can be set to be large according to, for example, an increase in the size of the other vehicle V recognized by the environment recognition unit 120 (an increase in the estimated weight of the other vehicle). Also, the target stroke can be set to be large according to an increase in the relative speed between the vehicle 1 and the other vehicle V recognized by the environment recognition unit 120, for example. This makes it possible to increase the amount of energy absorbed by each airbag when the collision energy is large. If the amount of contraction in the front-rear direction of the airbag that has opened the vent passage reaches the target stroke, the process proceeds to step S08; otherwise, step S07 is repeated.

[0038] <Step S08: Close the vent control valve> The airbag control unit 110 issues a command to the vent control valve 112 to close the vent passage that was opened in step S06. This causes the airbag to be in a state where it can generate resistance in response to input from another vehicle V. Then, proceed to step S09.

[0039] <Step S09: Disable the end airbag inner mounting part> The airbag control unit 110 issues a command to the mounting portion disabling actuator 114 to perform end airbag rotation control to disable the inner mounting portion 31 of the right airbag 30R or the left airbag 30L on the side where a collision is occurring (the side on which the vent passage was opened in step S06). As a result, the airbag rotates with the outer mounting portion 32 as a fulcrum in a direction in which the front end portion is swung outward in the vehicle width direction, and guides the other vehicle V in a direction away from the vehicle 1 (to pass by it). At this time, the behavior control unit 130 can control the braking force of the brake devices provided on each wheel to generate a braking force difference between the left and right wheels, thereby performing control to generate a yaw moment so that the vehicle 1 turns in the opposite direction to the other vehicle V. Then, the series of processes ends.

[0040] In this embodiment, as described above, in response to the establishment of the pre-crash determination by the environment recognition unit 120, first, the right airbag 30R, the central airbag 30C, and the left airbag 30L are all deployed as shown in FIG. At this time, the inner mounting portions 31 of the right airbag 30R and the left airbag 30L are not deactivated, and each airbag is in a rotation restricted state.

[0041] FIG. 4 is a diagram showing an example of a state after a vehicle having the airbag device of the embodiment collides with another vehicle. In the example shown in FIG. 4, another vehicle V collides from the front side of the vehicle 1 over almost the entire front areas of the central airbag 30C and the left airbag 30L, resulting in an offset collision with a relatively large overlap ratio. In this case, since it is difficult to turn the other vehicle V by controlling the rotation of the end airbags, the airbag control unit 110 opens the vent flow paths of all the airbags using the vent control valve 112 and maintains the right airbag 30R and the left airbag 30L in a rotation restricted state. In this case, as shown in FIG. 4, the center airbag 30C and the left airbag 30L collided with by the other vehicle V contract in the front-rear direction while discharging the deployment gas from the vent passages, thereby absorbing the collision energy.

[0042] FIG. 5 is a diagram showing a schematic diagram of another example of a state after a vehicle having the airbag device of the embodiment collides with another vehicle. In the example shown in Figure 5, another vehicle V is in contact with the front side of the vehicle 1 mainly against the left airbag 30L, and is in a specific offset collision (a collision in which damage can be mitigated by end airbag rotation control) with an overlap rate below a predetermined value. In this case, the airbag control unit 110 first issues a command to the vent control valve 112 to open the vent passage of the left airbag 30L, and causes the left airbag 30L to contract to a predetermined target stroke to absorb the collision energy. At this time, the mounting portion disabling actuator 114 maintains the left airbag 30 in a rotation restricted state.

[0043] Thereafter, when the left airbag 30L contracts to the target stroke, the airbag control unit 110 issues a command to the vent control valve 112 to close the vent flow path of the left airbag 30L to suppress the contraction, and further issues a command to the mounting portion disabling actuator 114 to disable the inner support portion 31, transitioning the left airbag 30L to a rotation-permitting state. As a result, the left airbag 30L is rotated by the force received from the other vehicle V in a direction in which the front end portion is swung outward in the vehicle width direction. The other vehicle V is guided to the left in the vehicle width direction as viewed from the vehicle 1 by the rotation of the left airbag 30L while being in close contact with the left airbag 30L, and is deflected in a direction away from the vehicle 1 as shown by the dashed arrow. At this time, the vehicle 1 starts turning to the left due to the yaw moment generated by the behavior control unit 130, as shown by the dashed-dotted arrow, in order to avoid the other vehicle V.

[0044] As described above, according to this embodiment, the following effects can be obtained. (1) In the event of an offset collision with another vehicle V in a specified manner, airbag rotation control is performed to rotate the right airbag 30R or the left airbag 30L in a direction such that the front end is swung outward in the vehicle width direction. With the surface of the airbag in close contact with the other vehicle V, the other vehicle V is guided by the rotation of the airbag and displaced outward in the vehicle width direction relative to vehicle 1. This allows the collision energy of the other vehicle V to be converted into kinetic energy that moves the other vehicle V away from the vehicle 1, reducing the amount of collision energy absorbed by the vehicle 1 and suppressing damage. (2) Prior to the airbag rotation control, the right side airbag 30R or the left exterior airbag 30L to be rotated is deflated, and end airbag deflation control is performed to maintain the deployment of the other airbags. This makes it possible to first deflate the right side airbag 30R or the left exterior airbag 30L to absorb a portion of the collision energy, and then rotate the airbag to convert the remaining collision energy into kinetic energy. This makes it possible to obtain the above-mentioned effects while reducing the energy input to the vehicle body structure and suppressing damage. (3) In the airbag contraction control, after the right airbag 30R or the left exterior airbag 30L to be contracted has contracted over a predetermined target stroke, the contraction of the airbag is suppressed (the vent is closed). After the airbag contracts to absorb a predetermined amount of energy, the contraction of the airbag is suppressed to generate sufficient resistance, thereby making it possible to more effectively obtain the above-mentioned effects. (4) The right side airbag 30R and the left side exterior airbag 30L are attached to the vehicle body by the inner support parts 31 and the outer support parts 32 arranged in a distributed manner in the vehicle width direction. By disabling the inner support parts 31 with the mounting part disabling actuator 114 to set the airbags in a rotation-permitted state, the right side airbag 30R and the left side airbag 30L can be transitioned from a rotation-restricted state to a rotation-permitted state with a simple configuration. (5) When the right airbag 30R or the left airbag 30L is allowed to rotate, the behavior control unit 130 generates a yaw moment toward the other side in the vehicle width direction (in the direction to avoid the other vehicle V), thereby turning the vehicle 1 in the direction to avoid the other vehicle V, and more effectively moving the vehicle 1 away from the other vehicle V.

[0045] (Modification) The present invention is not limited to the above-described embodiment, 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 embodiment, 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 contents of various controls, are not limited to the 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 embodiment, and may be modified as appropriate. (3) In the embodiment, for example, three airbags are arranged in the vehicle width direction, but the present invention is not limited to this, and for example, a configuration in which four or more airbags are arranged may be used. In addition, in the embodiment, one airbag each at the left and right ends in the vehicle width direction is made rotatable, but a plurality of airbags may be made rotatable at each end. (4) In the embodiment, the target stroke in the end airbag deflation control is set according to the size and relative speed of the colliding object, but the target stroke may be set based on other information. For example, if the object is another vehicle and the vehicle type can be identified by image recognition or the like, the weight of the other vehicle may be estimated and the target stroke may be set according to the estimated weight. (5) In the embodiment, a target stroke is set and the deflation of the airbag is terminated when the target stroke is reached. However, instead of this, the airbag deflation may be terminated, for example, after a certain time has elapsed after the start of venting. Also, the deflation of the airbag may be terminated based on the transition of the internal pressure of the deflated airbag. (6) The mounting structure of the rotating airbag to the vehicle body and the method of switching between the rotation restricted state and the rotation permitted state are not limited to the configurations of the above-described embodiments and may be modified as appropriate. (7) In the embodiment, the airbag at the side end is switched from the rotation restricted state to the rotation permitted state after an offset collision actually occurs. However, this is not limited to this. For example, if it is recognized that there is a high possibility of an offset collision when a pre-crash judgment is made, the airbag may be put into the rotation permitted state prior to the collision (in response to a precursor to the offset collision). (8) In the embodiment, a yaw moment is generated to turn the vehicle body toward the side opposite the collision side (to avoid the collision) by using the braking force difference between the left and right wheels, but the method of generating the yaw moment is not limited to this and other methods may be used. For example, a steering device that turns the steered wheels may be controlled to steer the vehicle toward the side opposite the collision side. Also, a torque vectoring device may be used to generate a driving force difference between the left and right wheels. [Explanation of symbols]

[0046] 1 car 10 compartments 20 Engine compartment 21 Front side frame 22 Bumper beam 23 Front bumper 30R Right side airbag 30C Center airbag 30L Left side airbag 31 Inner mounting portion 32 Outer mounting portion 110 Airbag control unit 111 Inflator 112 Vent control valve 113 Pressure sensor 114 Mounting Disable Actuator 120 Environment Recognition Unit 121 Stereo Camera Device 122 Millimeter wave radar equipment 123 Laser scanner equipment 130 behavior control unit 131 vehicle speed sensor 132 Acceleration sensor 133 Yaw rate sensor V Other vehicles

Claims

1. A plurality of airbags arranged in a vehicle width direction and deployed forward from a front part of a vehicle body; a pre-crash determination unit that establishes a pre-crash determination when the possibility of a collision with an object is equal to or higher than a predetermined value; an airbag deployment control unit that deploys the airbag in response to the establishment of the pre-crash determination; a collision type discrimination unit that discriminates a collision type with the object; An airbag device comprising: The airbag disposed at the end in the vehicle width direction is supported so that a front end portion of the airbag can be rotated in a direction to be swung outward in the vehicle width direction, an airbag rotation control unit that is switchable between a rotation restricted state in which the rotation is restricted and a rotation permitted state in which the rotation is permitted, The airbag rotation control unit performs an end airbag rotation control for allowing the airbag at the end on the side where the offset collision occurs in the vehicle width direction to rotate when the collision type is an offset collision. An airbag device comprising:

2. an airbag deflation control unit that individually controls the deflation of the plurality of airbags; The airbag contraction control unit performs an end airbag contraction control for contracting the airbag to be rotated and maintaining the deployment of the airbags in other portions prior to the end airbag rotation control.

2. The airbag device according to claim 1,

3. The airbag deflation control unit suppresses the deflation of the airbag after the deflated airbag has deflated over a predetermined target stroke.

3. The airbag device according to claim 2, wherein:

4. The airbag that is set in the rotation-permitted state by the airbag rotation control is attached to the vehicle body by a plurality of support points that are distributed in a vehicle width direction, The airbag rotation control unit disables the support point on the inner side in the vehicle width direction to allow the airbag to rotate.

4. The airbag device according to claim 1, wherein:

5. the vehicle includes a yaw moment generating device that generates a yaw moment on a vehicle body, When the airbag rotation control unit places the airbag at one end in a vehicle width direction in the rotation permitted state, the yaw moment generating device generates a yaw moment toward the other side in the vehicle width direction.

5. The airbag device according to claim 1, wherein:

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