JP7737232B2 - Airbag device - Google Patents

Description

The present invention relates to an airbag device having an airbag that deploys from the front of a vehicle body to the outside of the vehicle, such as an automobile.

As a technology relating to an airbag device that is deployed on the outside of a vehicle such as an automobile, for example, Patent Document 1 describes that when a collision with a pedestrian is predicted, the front portion of the front airbag is deployed to protect the pedestrian, and when parking, only the left and right corner bag portions are deployed to reduce contact damage.
Patent Document 2 describes that in order to prevent a pedestrian or other person who has been thrown up from falling and colliding with the road surface and suffering injuries to the head or face, an airbag positioned on the front side of the vehicle body is deployed, and a pedestrian behavior control unit formed on the front edge moves the pedestrian or other person to the side of the vehicle, preventing them from being thrown up onto the hood.
Patent Document 3 describes a method for predicting the weight of a specific pedestrian from an image obtained by an imaging device, and setting the airbag deployment conditions to provide optimal spring force, damping force, and deployment timing for a pedestrian airbag.

Furthermore, as a technology for determining the type of collision when a collision occurs, for example, Patent Document 4 describes a method for determining the type of collision, such as a full-overlap collision, an offset collision, or an oblique collision, based on the outputs of first and second acceleration sensors arranged on one and the other side of the vehicle width.
Furthermore, as a technique for controlling the deployment mode of airbags, for example, Patent Document 5 describes a technique for deploying a plurality of adjacently arranged airbags in a predetermined order so that they overlap each other.

Japanese Patent Application Laid-Open No. 2006-88893 Japanese Patent Application Laid-Open No. 2006-219119 Japanese Patent Application Laid-Open No. 2007-296941 JP 2019-162983 A Special table 2017-516702 publication

2. Description of the Related Art Generally, vehicles such as automobiles are designed so that the front structure of the vehicle body will collapse to absorb the collision energy in the event of a frontal collision.
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 any 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 vehicle being hit has a weight equivalent to that of the subject vehicle and the collision occurs at a relative speed of, for example, several tens of kilometers per hour.
However, in reality, there is a possibility that 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 one after the other may occur, and it is also possible that sufficient energy absorption may not be possible due to the crushing of the vehicle body structure alone.
For this reason, there is a demand for reducing damage in the event of a collision without excessively relying on the vehicle body structure.
In view of the above-mentioned problems, an object of the present invention is to provide an airbag device that can reduce damage in the event of a collision with an object.

In order to solve the above-mentioned problems, an airbag device according to a first aspect of the present invention is an airbag device including: a first airbag that deploys forward from a center in a vehicle width direction at a front part of a vehicle body; second airbags that deploy forward from both left and right sides of the first airbag at the front part of the vehicle body; a pre-crash determination unit that makes a pre-crash determination when the possibility of a collision with an object is equal to or greater than a predetermined value; and an airbag deployment control unit that deploys at least one of the first airbag and the second airbag in accordance with the pre-crash determination being made, the airbag device having a collision type prediction unit that predicts a type of collision with the object, and the airbag deployment control unit that determines whether the predicted collision type is a specific offset. In the case of a collision involving a vehicle offset, the left and right second airbags are deployed so that their inner ends in the vehicle width direction are in contact with or adjacent to each other at the vehicle width center, and then the first airbag is deployed so that it is in contact with the rear surface of the deployed second airbag, and airbag swing control is executed to swing or deform the second airbag so that the front end of the second airbag near the vehicle width center is displaced outward in the vehicle width direction, and the specific offset collision is an offset collision in which the overlap ratio between the vehicle and the object is equal to or less than a predetermined value and the inward component in the vehicle width direction of the relative velocity vector of the object with respect to the vehicle is equal to or less than a predetermined threshold.
According to this, by executing airbag swing control, an object that collides with the front of the second airbag can be guided outward in the vehicle width direction relative to the vehicle by swinging the second airbag, etc., thereby generating a behavior in which the object and the vehicle pass each other.
This allows collision energy to be converted into kinetic energy, reducing the energy input to the vehicle body and absorbed by the crushing of the vehicle body structure, thereby mitigating collision damage.

An airbag device according to a second aspect of the present invention is an airbag device including: a first airbag that deploys forward from a center portion in a vehicle width direction at a front portion of a vehicle body; second airbags that deploy forward from both left and right sides of the first airbag at the front portion of the vehicle body; a pre-crash determination unit that makes a pre-crash determination when the possibility of a collision with an object is equal to or greater than a predetermined value; and an airbag deployment control unit that deploys at least one of the first airbag and the second airbag in accordance with the pre-crash determination being made, wherein the airbag deployment control unit has a collision type prediction unit that predicts a collision type with the object, and when the predicted collision type is an offset collision, deploys the left and right second airbags so that inner ends of the second airbags in the vehicle width direction abut or are adjacent to each other at the center portion in the vehicle width direction. and an airbag swinging control for deploying the first airbag after the first airbag is deployed so that the first airbag abuts against a rear portion of the deployed second airbag near the center in the vehicle width direction , and swinging or deforming the second airbag so that the front end of the second airbag is displaced outward in the vehicle width direction; or an inclined surface forming control for deploying the left and right second airbags after the first airbag is deployed so that the second airbags press against and abut against side portions of the first airbag, and forming inclined surfaces with the surface portions of the first airbag and the second airbag such that the rear side of the vehicle protrudes outward in the vehicle width direction relative to the front side of the vehicle, and selecting whether to execute the airbag swinging control or the inclined surface forming control based on at least one of a relative velocity vector of the object with respect to the vehicle and an overlap rate predicted at the time of a collision.
In the slope formation control, the input from the object to the first and second airbags is transmitted to the vehicle body via the slope, generating a yaw moment that causes the vehicle to begin turning in the opposite direction from the side that experienced the offset collision.
This causes the vehicle to turn away from the impacted side while carrying the object, converting part of the impact energy from the object into kinetic energy, thereby reducing the amount of energy absorbed by the vehicle body structure due to crushing and other causes, and mitigating damage caused by the vehicle collision.
In addition, by selecting and executing either airbag swing control or slope formation control based on at least one of the object's relative velocity vector with respect to the vehicle and the overlap ratio, it is possible to effectively mitigate collision damage appropriate for the type of offset collision.

In the invention according to the second aspect, the airbag deployment control unit may be configured to execute the inclined surface formation control when the overlap ratio is equal to or greater than a predetermined threshold value.
In addition, in the invention relating to the second aspect, the airbag deployment control unit can be configured to execute the slope portion formation control when the overlap ratio is less than a predetermined threshold value and the relative velocity vector of the object with respect to the vehicle has a predetermined or greater component in a direction approaching the center of the vehicle in the vehicle width direction.
According to this, by performing slope portion formation control for offset collision types in which the effect of slope portion formation control in reducing collision damage is large, damage in these collision types can be effectively suppressed, and in other offset collisions, damage can be reduced by airbag oscillation control.

In each of the above inventions, the airbag deployment control unit can be configured to not deploy the first airbag when the predicted collision type is a full-wrap collision, but to deploy the left and right second airbags in abutting or adjacent state in the center of the vehicle width direction.
With this, the left and right second airbags can stably catch an object colliding from the front side of the vehicle, and the second airbags can effectively absorb the collision energy.

As described above, the present invention provides an airbag device that can reduce damage during a collision with an object.

1 is a diagram schematically illustrating a configuration of a first embodiment of an airbag device to which the present invention is applied; 1 is a block diagram schematically illustrating a configuration of a system for controlling an airbag device according to a first embodiment. 5 is a flowchart illustrating an operation of the airbag device of the first embodiment during a collision. 1 is a diagram schematically illustrating a state after a vehicle having an airbag device according to a first embodiment has undergone a full-overlap collision with another vehicle; 1 is a diagram schematically illustrating a state after a vehicle having an airbag device according to a first embodiment has collided with another vehicle in an offset manner and airbag oscillation control has been performed; 1 is a diagram schematically illustrating a state immediately before a vehicle having an airbag device according to a first embodiment collides with another vehicle in an oblique offset manner; 10A and 10B are diagrams illustrating a state after a vehicle having the airbag device of the first embodiment has collided with another vehicle in an oblique offset manner and slope portion formation control has been performed; 10 is a flowchart illustrating an operation of an airbag device according to a second embodiment of the present invention at the time of a collision.

First Embodiment
A first embodiment of an airbag device to which the present invention is applied will now be described.
The airbag device of the first embodiment is provided in the front part of the body of an automobile such as a passenger car, for example, and is intended to reduce damage when the automobile collides with an object such as another vehicle.
FIG. 1 is a diagram schematically illustrating the configuration of an airbag device according to a first embodiment.
FIG. 1 shows a vehicle having an airbag device according to a first 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 .

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 for accommodating power train components such as an engine, a transmission, and, in the case of an electric vehicle, a motor generator and its control devices.
The engine compartment 20 is provided with a front side frame 21, a bumper beam 22, a front bumper 23, and the like.

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 .
The front side frame 21 functions as a base to which components such as a power train, a cross member to which a front suspension is attached, and a strut housing that houses a strut of a McPherson strut type front suspension are attached.
The front side frame 21 is formed by assembling and welding together members formed by press-molding steel plates, for example, so that its cross-sectional shape when viewed from the front-rear direction of the vehicle is a rectangular closed cross-section.

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-like shape with a closed cross section, for example, by assembling and welding together members formed by press-molding steel plates, or by using an extruded aluminum alloy material.
The bumper beam 22 has its middle portion joined 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 transmission member that transmits the load received by the central airbag 30C, right airbag 30R, and left airbag 30L (described later) from an object that they collide with to the rear side of the vehicle body via the front side frame 21.

The front bumper 23 is an exterior component provided at the front end of the vehicle body, and is configured by attaching a bumper face, which is made of, for example, a PP-based resin and forms the surface portion, 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 is convex when the vehicle 1 is viewed from above.
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 curve of the front portion of the front bumper 23.

The airbag device of the first 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 judgment.
The central airbag 30C is provided in the center of the vehicle body in the vehicle width direction.
The center airbag 30C functions as the primary airbag of the present invention.
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 right airbag 30R and the left airbag 30L function as a second airbag of the present invention.
In FIG. 1, the right airbag 30R and the left airbag 30L are shown deployed, while the central airbag 30C is shown undeployed.

The central airbag 30C, the right airbag 30R, and the left airbag 30L are normally (before a pre-crash determination is made) attached to the bumper beam 22 in a folded state and housed inside the front bumper 23.
In the event of a collision, each airbag breaks a weakened portion formed in the front bumper 23 and is deployed forward of the vehicle, deploying forward in front of the front bumper 23 .

When only the right airbag 30R and the left airbag 30L are deployed, the inner ends of the airbags in the vehicle width direction abut against or are adjacent to each other at the center in the vehicle width direction.
In this state, the central airbag 30C is positioned rearward of the right airbag 30R and the left airbag 30L, facing the areas in contact or adjacent to the right airbag 30R and the left airbag 30L at a distance in the front-to-rear direction.

FIG. 2 is a block diagram that schematically shows the 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 ROM, an input/output interface, and a bus connecting these.
Furthermore, the units are connected to each other via an in-vehicle LAN such as a CAN communication system or directly, and are capable of communicating with each other.

The airbag control unit 110 issues commands to the inflator 111 and the vent control valve 112, and controls them to deploy the right airbag 30R, the center airbag 30C, and the left airbag 30L, and to control the deployment state.
The airbag control unit 110 functions as an airbag deployment control unit of the present invention.
The inflator 111 is a chemical (pyrotechnical) gas generator that generates gas for inflating 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 they start to be deployed.

The vent control valves 112 are provided in the right airbag 30R, the center airbag 30C, and the left airbag 30L, respectively, and open and close vent flow paths (not shown) that discharge gas from inside each airbag (for example, 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 be configured to include, for example, an electromagnetic valve.

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 center airbag 30C, and the left airbag 30L.
The airbag control unit 110 can detect the load input state to each airbag based on the output of the pressure sensor 113 .

The environment recognition unit 120 recognizes the environment around the vehicle based on the outputs of various sensors.
The environment recognition unit 120 has the function of recognizing, for example, various objects around the vehicle 1 (host vehicle), such as other vehicles, pedestrians, buildings, trees, and terrain, as well as road shapes (lane shapes).
The environment recognition unit 120 functions as a pre-crash determination section that makes a pre-crash determination when a collision with an object such as another vehicle is unavoidable (when the possibility of collision is greater than or equal to a predetermined value).
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.

The stereo camera device 121 has a pair of cameras arranged at a predetermined distance (baseline length) apart, and is capable of recognizing objects such as other vehicles, pedestrians, and cyclists, and detecting the relative position of the objects with respect to the vehicle 1 using 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, if 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 that is significantly heavier than the vehicle 1, such as a truck, bus, or large SUV).

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 an object and the relative position of the object with respect to the vehicle 1.
The laser scanner device (LIDAR) 123 has the function of scanning the area around the vehicle 1 by emitting, for example, pulsed near-infrared laser light, and detecting the presence or absence of an object, the relative position of the object 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 type of collision 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 vehicle 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 functions as a collision type prediction unit that predicts the type of collision with an object.

Next, the operation of the airbag device of the first embodiment will be described.
FIG. 3 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.

<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 defined in the present invention) approaching from the front of the vehicle 1, and determines whether the estimated possibility is greater than or equal to a preset threshold value.
If the possibility of a collision is equal to or greater than the threshold, a collision is deemed unavoidable, a pre-crash determination is made, and the process proceeds to step S02; otherwise, the series of processes is ended (returned).

<Step S02: Collision Type Recognition>
The airbag control unit 110 recognizes the predicted mode of collision of the other vehicle with the vehicle 1 .
The collision type can be recognized based on information from the environment recognition unit 120, for example.
For example, the collision position of the other vehicle with respect to vehicle 1 (the range of subject vehicle 1 that will be hit by the other vehicle) and the velocity vector of the other vehicle with respect to subject vehicle 1 immediately before the collision are recognized based on the results of monitoring the relative position of the other vehicle with respect to vehicle 1 before and after the collision using the stereo camera device 121, millimeter wave radar device 122, and laser scanner device 123. This velocity vector includes information regarding the relative velocity of the other vehicle with respect to vehicle 1 and the collision direction (angle).
Then, proceed to step S03.

<Step S03: Offset Collision Determination>
The airbag control unit 110 determines whether the collision type recognized in step S02 is an offset collision (including an oblique offset collision) in which an object collides with an area biased to either the left or right side of the front of the vehicle body.
If it is determined that the collision is an offset collision, the process proceeds to step S04, and otherwise the process proceeds to step S08.

<Step S04: Determining Offset Rate>
The airbag control unit 110 determines whether the overlap ratio (the ratio of the collision area to the width of the front end of the vehicle body) expected in the event of a collision is equal to or greater than a preset threshold value.
If the overlap rate is equal to or greater than the threshold, the process proceeds to step S06, and if the overlap rate is less than the threshold, the process proceeds to step S05.

<Step S05: Determining an Inward Oblique Collision of the Own Vehicle>
The airbag control unit 110 acquires information about the relative velocity vector of the object relative to the host vehicle immediately before the collision from the environment recognition unit 120, and determines whether the inward velocity component in the vehicle width direction of the host vehicle (the direction approaching the center of the vehicle width direction of the vehicle 1) is greater than or equal to a predetermined value.
If the inward velocity component is equal to or greater than a predetermined value, it is determined that the collision is an oblique offset collision from the outside in the vehicle width direction, and the process proceeds to step S06; otherwise, the process proceeds to step S07.

<Step S06: Slope portion formation control>
The airbag control unit 110 executes slope formation control to form a slope that is inclined relative to the fore-and-aft direction of the vehicle body 1 so that the surface of the airbag group consisting of the right airbag 30R, one of the left airbags 30L, and the central airbag 30C gradually protrudes outward in the vehicle width direction from the front to the rear of the vehicle 1.
The specific contents of the slope portion formation control will be explained in detail later.
Then, the series of processes ends.

<Step S07: Airbag oscillation control>
The airbag control unit 110 executes airbag swing control to swing the right airbag 30R and the left airbag 30L in a direction in which the front ends of the right airbag 30R and the left airbag 30L are displaced outward in the vehicle width direction (spreading to the left and right).
The specific contents of the airbag swing control will be explained in detail later.
Then, the series of processes ends.

<Step S08: Deploying left and right airbags>
The airbag control unit 110 deploys the right airbag 30R and the left airbag 30L.
At this time, the central airbag 30 is maintained in an undeployed state.
Additionally, the vent control valve 112 opens the vent passages of the right airbag 30R and the left airbag 30L.
Then, the series of processes ends.

The states, functions and effects of the airbag device of the first embodiment in each of the above-described airbag control modes will now be described.
FIG. 4 is a diagram schematically showing a state after a vehicle equipped with the airbag device of the first embodiment has undergone a full-overlap collision with another vehicle.
If the pre-crash determination is established and the predicted collision type is a full-overlap collision, the right airbag 30R and the left airbag 30L are deployed, and the central airbag 30C is left undeployed, as shown in FIG.
Additionally, the vent passages of the right airbag 30R and the left airbag 30L are opened.
As shown in FIG. 4, another vehicle V collides with the front portions of the right airbag 30R and the left airbag 30L.
At this time, the right airbag 30R and the left airbag 30L contract while discharging gas from the inside through the vent passages, thereby absorbing the collision energy.

Next, the airbag swing control will be described in detail.
FIG. 5 is a diagram schematically showing a state after a vehicle equipped with the airbag device of the first embodiment has collided with another vehicle in an offset manner and airbag swing control has been performed.
When the pre-crash determination is established and the predicted collision type is an offset collision with a relatively small overlap ratio, the right airbag 30R and the left airbag 30L are first deployed, as shown in FIG. 1, while the central airbag 30C is left undeployed.
Additionally, the vent passages of the right airbag 30R and the left airbag 30L are closed.

Thereafter, another vehicle V collides with the front portion of either the right airbag 30R or the left airbag 30L.
FIG. 5 illustrates a case where another vehicle collides with the left airbag 30L.
When another vehicle V collides with the left airbag 30L, the pressure sensor 113 detects an increase in the internal pressure of the left airbag 30L.
When the internal pressure of the left airbag 30L increases to or exceeds a predetermined value, the airbag control unit 110 issues a command to the inflator 111 to inflate the central airbag 30C.
The central airbag 30C deploys while pushing forward the rear portions of the right airbag 30R and the left airbag 30L near the center in the vehicle width direction.
As a result, the right airbag 30R and the left airbag 30L are deformed so that their front ends swing and collapse in a direction widening in the vehicle width direction, with the attachment points to the vehicle body (bumper beam 22, etc.) as fulcrums.
Due to this deformation, the collision energy of the other vehicle V is converted into kinetic energy, and the other vehicle V turns so as to be displaced to the left in the vehicle width direction as seen from the vehicle 1, and is guided to pass the other vehicle 1. (The state shown by the dashed line transitions to the state shown by the solid line.)

Next, the specific contents of the slope portion formation control will be described.
FIG. 6 is a diagram schematically showing a state immediately before a vehicle equipped with the airbag device of the first embodiment collides obliquely with another vehicle at an offset.
When the pre-crash determination is established and the predicted collision type is an offset collision with a relatively large overlap ratio with respect to the time of airbag swing control, or when it is an inward oblique offset collision (oblique collision) with a relative velocity vector pointing inward toward the host vehicle, the airbag control unit 110 first deploys only the center airbag 30C, as shown in FIG. 6.
The central airbag 30C passes between the undeployed right airbag 30R and left airbag 30L and deploys and inflates toward the front of the vehicle.

After a predetermined time interval has elapsed since the central airbag 30C was deployed, the airbag control unit 110 deploys the right airbag 30R and the left airbag 30L.
FIG. 7 is a diagram schematically showing a state after a vehicle having the airbag device of the first embodiment has collided with another vehicle at an oblique offset and the inclined surface formation control has been performed.
The inner portions of the right airbag 30R and the left airbag 30L in the vehicle width direction come into contact with and press the side portions of the central airbag 30C, causing the side portions of the central airbag 30C to become depressed and sink into the interior of the central airbag 30.
The central airbag 30 is pressed and depressed at its intermediate portion in the front-rear direction by the right airbag 30R and the left airbag 30L, thereby increasing the internal pressure.
As a result, the front portion of the central airbag 30C is inflated so as to wrap around the front portions of the right airbag 30R and the left airbag 30L.
At this time, the side portions at the front of the central airbag 30C, and the front portions and outer side portions in the vehicle width direction of the right airbag 30R and the left airbag 30L form a sloped portion S that is inclined in the fore-and-aft direction of the vehicle 1 so as to gradually protrude outward in the vehicle width direction from the front to the rear of the vehicle 1.

When a load F is input to the sloped surface S due to a collision with another vehicle V, a yaw moment is generated that turns the vehicle 1 to the side opposite the collision side (to the right if the collision occurs from the left side of the vehicle 1 as shown in FIG. 7 ). This yaw moment causes the vehicle 1 to start turning to the right as shown by the dashed arrow.
At this time, the other vehicle V starts turning to the left as shown by the dashed arrow, and transitions from the state shown by the solid line to the state shown by the dashed line.
Thereafter, the vehicle 1 and the other vehicle V move forward side by side with their front bodies in contact with each other. For example, in the example shown in FIG. 7, the vehicles move upward in FIG.

As described above, according to the first embodiment, the following effects can be obtained.
(1) In the case of an offset collision with a relatively small overlap ratio, by executing airbag swing control, another vehicle V that has collided with the front of the right airbag 30R or the left airbag 30L can be guided outward in the vehicle width direction relative to vehicle 1 by the swing of the right airbag 30R or the left airbag 30L, thereby generating a behavior in which the other vehicle V and vehicle 1 pass each other.
This converts the collision energy into kinetic energy, reducing the energy input to the vehicle body and mitigating collision damage.
(2) In the case of an offset collision or an oblique offset collision (oblique collision) with a relatively large overlap ratio, by performing slope formation control, the input from the other vehicle V to each airbag is transmitted to the vehicle body via the slope, generating a yaw moment that causes the vehicle 1 to begin turning in the opposite direction from the side that was hit by the offset collision.
As a result, vehicle 1 turns to the opposite side of the collision side while accompanying other vehicle V, converting part of the collision energy input from other vehicle V into kinetic energy, thereby reducing the amount of energy absorbed by the body structure, etc., and mitigating collision damage to vehicle 1.
(3) By selecting and executing either airbag swing control or slope formation control based on the relative velocity vector of the other vehicle V with respect to vehicle 1 and the overlap ratio, it is possible to effectively mitigate collision damage appropriate for the type of offset collision.
(4) When the overlap ratio is equal to or greater than a predetermined threshold, if the relative velocity vector of the other vehicle V with respect to the vehicle 1 has a component in the direction approaching the center of the vehicle in the vehicle width direction, by executing slope formation control, damage in these collision types can be effectively suppressed, and in other offset collisions, damage can be reduced by airbag swing control.
(5) In the event of a full-overlap collision, etc., the right airbag 30R and the left airbag 30L are deployed in a state of abutting or adjacent to each other in the center of the vehicle width direction, so that the right airbag 30R and the left airbag 30L can stably receive another vehicle V colliding from the front side of the vehicle 1, and the right airbag 30R and the left airbag 30L can effectively absorb the collision energy.

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 to designate parts common to the first embodiment, and explanations thereof will be omitted, and differences will be mainly described.
In the second embodiment, the inclined surface formation control in the first embodiment is not performed, and only the airbag swing control is executed in the event of an offset collision.
FIG. 8 is a flowchart illustrating the operation of the airbag device of the second embodiment in the event of a collision.
Each step will be explained in order below.

<Step S11: Pre-crash Determination Establishment Determination>
If the environment recognition unit 120 determines that the pre-crash has occurred, the process proceeds to step S12, otherwise the process ends (returns).

<Step S12: Collision Type Recognition>
The airbag control unit 110 recognizes the predicted mode of collision of the other vehicle with the vehicle 1 based on information from the environment recognition unit 120 .
Then, proceed to step S13.

<Step S13: Offset Collision Determination>
The airbag control unit 110 determines whether the collision type recognized in step S12 is a specific offset collision in which the collision damage can be mitigated by airbag swing control.
For example, if the expected overlap ratio is below a predetermined value and the relative velocity vector of the other vehicle with respect to vehicle 1 does not contain a component directed inward in the vehicle width direction of vehicle 1 (or if the inward velocity component is below a predetermined threshold), it can be determined that a specific offset collision has occurred.
If it is determined that the collision is a specific offset collision, the process proceeds to step S14, otherwise the process proceeds to step S15.

<Step S14: Airbag oscillation control>
The airbag control unit 110 executes airbag swing control.
Then, the series of processes ends.

<Step S15: Deploying left and right airbags>
The airbag control unit 110 deploys the right airbag 30R and the left airbag 30L.
At this time, the central airbag 30 is maintained in an undeployed state.
Additionally, the vent control valve 112 opens the vent passages of the right airbag 30R and the left airbag 30L.
Then, the series of processes ends.

In the second embodiment described above, the control logic is simpler than in the first embodiment, and the same collision damage mitigation effect as in the first embodiment can be achieved through airbag swing control in offset collisions with a relatively small overlap ratio.

(Modification)
The present invention is not limited to the above-described embodiments, and various modifications and variations are possible, and these are also within the technical scope of the present invention.
(1) The configurations of the airbag device and the vehicle are not limited to those of 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 contents of various controls, are not limited to the embodiments and can be changed as appropriate.
(2) The method for making a pre-crash determination and the method for determining the type of collision are not limited to the methods described in the respective embodiments and may be modified as appropriate.
(3) The method of swinging the airbag in each embodiment is merely an example and can be modified as appropriate.
For example, in the embodiment, the front ends of the right and left airbags are swung in the expanding direction by deformation of the right and left airbags, but the bases of the airbags may be attached to the vehicle body so as to be rotatable.
(4) The method for forming the sloped surface in the first embodiment is an example and can be modified as appropriate.
For example, the shape, positional relationship, number of airbags, etc. of the group of airbags that make up the slope portion can be changed as appropriate.

REFERENCE SIGNS LIST 1 Vehicle 10 Vehicle interior 20 Engine compartment 21 Front side frame 22 Bumper beam 23 Front bumper 30R Right airbag 30C Center airbag 30L Left airbag 110 Airbag control unit 111 Inflator 112 Vent control valve 113 Pressure sensor 120 Environment recognition unit 121 Stereo camera device 122 Millimeter wave radar device 123 Laser scanner device V Other vehicle S Slope portion

Claims (7)

a first airbag that deploys forward from a center portion in a vehicle width direction at a front portion of a vehicle body of the vehicle;
a second airbag that deploys forward from both left and right sides of the first airbag in the front portion of the vehicle body;
a pre-crash determination unit that makes a pre-crash determination when the possibility of a collision with an object is equal to or greater than a predetermined value;
an airbag deployment control unit that deploys at least one of the first airbag and the second airbag in response to the establishment of the pre-crash determination,
a collision type prediction unit that predicts a collision type with the object,
When the predicted collision type is a specific offset collision, the airbag deployment control unit deploys the left and right second airbags so that inner ends of the second airbags in the vehicle width direction abut or are adjacent to each other at a center portion in the vehicle width direction, and then deploys the first airbag so that it abuts on a rear surface portion of the deployed second airbag, and executes airbag swing control to swing or deform the second airbag so that a front end of the second airbag in the vicinity of the center portion in the vehicle width direction is displaced outward in the vehicle width direction,
The specific offset collision is an offset collision that occurs when an overlap ratio between the vehicle and the object is equal to or less than a predetermined value, and an inward component of a relative velocity vector of the object with respect to the vehicle in a vehicle width direction is equal to or less than a predetermined threshold. a first airbag that deploys forward from a center portion in a vehicle width direction at a front portion of a vehicle body of the vehicle;
a second airbag that deploys forward from both left and right sides of the first airbag in the front portion of the vehicle body;
a pre-crash determination unit that makes a pre-crash determination when the possibility of a collision with an object is equal to or greater than a predetermined value;
an airbag deployment control unit that deploys at least one of the first airbag and the second airbag in response to the establishment of the pre-crash determination,
a collision type prediction unit that predicts a collision type with the object,
and an airbag deployment control unit that, when the predicted collision type is an offset collision, executes one of the following: airbag swinging control, in which the airbag deployment control unit deploys the left and right second airbags so that inner ends of the second airbags in the vehicle width direction abut or are adjacent to each other at a center portion in the vehicle width direction, and then deploys the first airbag so that it abuts against a rear surface portion of the deployed second airbag near the center portion in the vehicle width direction, thereby swinging or deforming the second airbag so that a front end of the second airbag is displaced outward in the vehicle width direction; or slope portion formation control, in which, after the first airbag is deployed, the airbag deployment control unit deploys the left and right second airbags so that they press against side portions of the first airbag and abut against each other, thereby forming slope portions with surface portions of the first airbag and the second airbag that protrude outward in the vehicle width direction with respect to the front side of the vehicle, and selects whether to execute the airbag swinging control or the slope portion formation control based on at least one of a relative velocity vector of the object with respect to the vehicle and an overlap ratio predicted at the time of the collision. The airbag device according to claim 2, wherein the airbag deployment control unit executes the inclined surface formation control when the overlap ratio is equal to or greater than a predetermined threshold value. 4. The airbag device according to claim 3, wherein the airbag deployment control unit executes the slope portion formation control when the overlap ratio is less than a predetermined threshold and a relative velocity vector of the object with respect to the vehicle has a predetermined or greater component in a direction approaching a center of the vehicle in a vehicle width direction. 5. The airbag device according to claim 1, wherein the airbag deployment control unit does not deploy the first airbag, and deploys the left and right second airbags in abutting or adjacent state at a center portion in the vehicle width direction, when the predicted collision type is a full-overlap collision. the first airbag has a first vent control valve that opens and closes a vent passage that discharges gas from the first airbag;
6. The airbag device according to claim 1, wherein the second airbag has a second vent control valve that opens and closes a vent passage that discharges gas from the second airbag. 7. The airbag device according to claim 1, further comprising a pressure sensor for detecting the internal pressure of the first airbag and the second airbag.