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 first air bag 30C which is developed from a vehicle width direction center part at a vehicle body front part to a front side; second air bags 30R, 30L which are developed from the side part of the first air bag to the front side; a pre-crash determination part 120 which establishes a pre-crash determination with an obstacle and discriminates a collision form to be predicted; an air bag development control part 110 which develops at least one of the first air bag and the second air bag according to the establishment of the pre-crash determination; and a collision form prediction part which predicts collision form with an obstacle. The air bag development control part performs, when the predicted collision form is off-set collision, a slope part formation control in which the second air bag is developed after the first air bag is developed and a slope part S is formed where surface parts of the first air bag and the second air bag are spread out at the vehicle rear side in a vehicle width direction outer side in comparison with the vehicle front side.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] As a technology related to an airbag device that deploys to 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 part of the front airbag is deployed for pedestrian protection, and in the parking operation state, only the left and right corner bag parts are deployed to reduce contact damage. Patent Document 2 describes that in order to prevent a pedestrian or the like who has been bounced up from falling and being injured in the head or face due to a collision with the road surface, an airbag bag body arranged on the front side surface of the vehicle body is deployed, and a pedestrian behavior control part formed at the front edge part moves the pedestrian or the like to the side of the vehicle so as not to be bounced up onto the hood. Patent Document 3 describes that in a pedestrian airbag, the weight of a specific pedestrian is predicted from an image obtained by an imaging device, and the airbag deployment conditions are set so as to obtain an optimal spring force, damping force, and deployment timing.

[0003] Also, as a technology related to the determination of the collision form at the time of a collision, for example, Patent Document 4 describes that based on the outputs of first and second acceleration sensors arranged on one side and the other side in the vehicle width direction, the collision form such as a full wrap collision, an offset collision, and an oblique collision is determined. Also, as a technology related to the control of the deployment form of an airbag, for example, Patent Document 5 describes that a plurality of adjacent airbags are deployed in a predetermined order so as to overlap.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] Generally, in vehicles such as automobiles, it is designed in consideration of crushing the front structure of the vehicle body to absorb collision energy during a frontal collision. Even when the airbag is deployed outside the vehicle, usually the load received by the airbag is transmitted to the vehicle body structure member, and the collision energy that cannot be completely absorbed by the airbag is absorbed by the crushing of the vehicle body structure. Such energy absorption is often assumed when the other vehicle as the collision partner has the same vehicle weight as the own vehicle and collides at a relative speed of, for example, several tens of km / h. However, in reality, there is a possibility of a collision with a vehicle larger than the own vehicle, a collision with a vehicle at a speed higher than the assumed vehicle speed, a multiple collision in which the vehicle collides successively with a plurality of vehicles, etc., and it is also assumed that sufficient energy absorption cannot be achieved only by crushing the vehicle body structure. For this reason, there is a demand for reducing damage during a collision without relying too much on the vehicle body structure. In view of the above problems, an object of the present invention is to provide an airbag device capable of reducing damage during a collision with an object. [Means for Solving the Problems

[0006] To solve the above problems, the airbag device of the present invention includes a first airbag that deploys from the center in the vehicle width direction to the front side at the front part of the vehicle body of the vehicle, and the first airbag at the front part of the vehicle bodyBoth left and right a second airbag that expands from the side portion toward the front side, and a pre-crash determination is made when the possibility of a collision with an object is equal to or greater than a predetermined level of the a reclash determination unit, and 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, the airbag device having a collision form prediction unit that predicts a collision form with the object, and the airbag deployment control unit being configured such that when the predicted collision form is specific in the case of an offset collision, after deploying the first airbag, the second airbag is deployed so as to abut against a side surface portion of the first airbag by pressing characterized in that it executes a slope surface formation control for forming a slope surface in which the rear side of the vehicle protrudes outward in the vehicle width direction with respect to the front side of the vehicle by the surface portions of the first airbag and the second airbag. In the specification and claims, the offset collision includes an oblique offset collision (also referred to as an obliquity collision) in which an object collides from a direction inclined with respect to the longitudinal direction of the host vehicle. According to this, since the input from the object to the first and second airbags is transmitted to the vehicle body via the slope surface, a yaw moment for starting a turn is generated toward the side opposite to the side on which the vehicle has received the offset collision. As a result, the vehicle turns toward the side opposite to the collision side with the object, and a part of the collision energy input from the object is converted into kinetic energy. For this reason, the amount of energy absorption due to crushing of the vehicle body structure or the like can be reduced, and the collision damage to the vehicle can be mitigated.

[0007] In the present invention, the airbag deployment control unit may be configured to execute the slope surface formation control when a lap rate predicted at the time of collision with the object is equal to or greater than a predetermined threshold value. Further, in the present invention, the airbag deployment control unit may be configured to execute the slope surface formation control when a component of the relative velocity vector of the object with respect to the vehicle in a direction approaching the center side in the vehicle width direction of the vehicle is equal to or greater than a predetermined value. According to each of these inventions, by performing the inclined surface formation control for a collision mode in which the effect of reducing collision damage by the inclined surface formation control is large, the damage in these collision modes can be effectively suppressed. Further, in other collision modes, it does not prevent performing deployment control of an airbag suitable for the collision mode and the like.

[0008] In the present invention, when the predicted collision mode is a full wrap collision, the airbag deployment control unit without deploying the first airbag can be configured to deploy the left and right second airbags in a state of being in contact with or adjacent to each other at the center in the vehicle width direction. According to this, an object colliding from the front side of the own vehicle can be stably received by the left and right second airbags, and the collision energy can be effectively absorbed by the second airbags.

Effect of the Invention

[0009] As described above, according to the present invention, it is possible to provide an airbag device capable of reducing damage at the time of collision with an object.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of an airbag device to which the present invention is applied will be described. The airbag device according to the embodiment is provided, for example, at the front part of the vehicle body of an automobile such as a passenger car, and aims to reduce damage when colliding with an object such as another vehicle. FIG. 1 is a diagram schematically showing the configuration of the airbag device according to the embodiment. FIG. 1 shows a state of a vehicle having the airbag device according to the embodiment as viewed from above. The vehicle 1 has, for example, a so-called two-box type vehicle shape having an engine compartment 20 that protrudes forward of the passenger compartment 10.

[0012] The passenger compartment 10 is a part having a space where passengers and the like are accommodated. The engine compartment 20 is a part having a space where 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 accommodated. The engine compartment 20 is provided with a front side frame 21, a bumper beam 22, a front bumper 23, and the like.

[0013] The front side frame 21 is a structural member that protrudes forward of the vehicle from a turbo board (not shown) which is a partition provided at the front end of the passenger compartment 10. 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 a strut of a MacPherson strut type front suspension are attached. The front side frame 21 is formed by integrating and welding members formed by press-molding a steel plate, for example, and has a closed cross-section with a rectangular cross-sectional shape when viewed from the vehicle longitudinal direction.

[0014] The bumper beam 22 is a structural member provided at the front part of the vehicle body and extending in the vehicle width direction. The bumper beam 22 is formed in a beam shape with a closed cross-section, for example, by integrating and welding members formed by press-molding a steel plate, or by using an extruded material of an aluminum-based alloy. The middle part of the bumper beam 22 is coupled to the front end parts of the left and right front side frames 21. Both end parts of the bumper beam 22 in the vehicle width direction protrude outward in the vehicle width direction with respect to the front side frame 21. The bumper beam 22 is a load transmission member that transmits the load received by the central airbag 30C, the right side airbag 30R, and the left side airbag 30L, which will be described later, from the object of collision to the rear side of the vehicle body via the front side frame 21.

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

[0016] The airbag device of the embodiment includes a central airbag 30C, a right side airbag 30R, and a left side airbag 30L. Each airbag is formed in a bag shape, for example, by joining a panel made of a base fabric such as nylon 66 fabric, and is deployed by blowing in the deployment gas generated by the inflator 111 in response to the establishment of pre-crash determination. The center airbag 30C is provided at the center of the vehicle body in the vehicle width direction. The center airbag 30C functions as the first airbag of the present invention. The right airbag 30R is provided adjacent to the center airbag 30C on the right side in the vehicle width direction. The left airbag 30L is provided adjacent to the center airbag 30C on the left side in the vehicle width direction. The right airbag 30R and the left airbag 30L function as the second airbag of the present invention. In FIG. 1, while the right airbag 30R and the left airbag 30L are deployed, the center airbag 30C shows an undeployed state.

[0017] The center airbag 30C, the right airbag 30R, and the left airbag 30L are attached to the bumper beam 22 in a folded state and housed inside the front bumper 23 during normal times (before the pre-crash determination is established). At the time of a collision, each airbag breaks through the weak portion formed in the front bumper 23 and is extended toward the front side of the vehicle, and is deployed forward with respect to the front surface of the front bumper 23.

[0018] When only the right airbag 30R and the left airbag 30L are deployed, the inner ends of each airbag in the vehicle width direction abut or are adjacent to each other at the center in the vehicle width direction. In this state, the center airbag 30C is disposed opposite to the region where the right airbag 30R and the left airbag 30L abut or are adjacent to each other at the rear side of the right airbag 30R and the left airbag 30L with a space in the front-rear direction.

[0019] FIG. 2 is a block diagram schematically showing the configuration of a system for controlling the airbag device according to the embodiment. The system for controlling the airbag device includes 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 and a ROM, an input / output interface, and a bus for connecting these components. Also, each unit is connected, for example, via an in-vehicle LAN such as a CAN communication system or directly, enabling mutual communication.

[0020] The airbag control unit 110 gives 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 deployed state. The airbag control unit 110 functions as the airbag deployment control unit of the present invention. The inflator 111 is a chemical (gunpowder type) gas generator that generates deployment gas for deploying each airbag in response to a command from the airbag control unit 110. The inflator 111 is provided independently for the right airbag 30R, the center airbag 30C, and the left airbag 30L, and can individually control the presence or absence of deployment and the timing of starting deployment of the right airbag 30R, the center airbag 30C, and the left airbag 30L.

[0021] The vent control valve 112 is provided for the right airbag 30R, the center airbag 30C, and the left airbag 30L respectively, and opens and closes a vent flow path (not shown) for discharging gas (for example, releasing to the atmosphere) from within each airbag. The vent control valve 112 has a function of independently opening and closing the vent flow paths of the right airbag 30R, the center airbag 30C, and the left airbag 30L, for example, in response to a command from the airbag control unit 110. The vent control valve 112 can be configured to have, for example, an electromagnetic valve.

[0022] A pressure sensor 113 is provided in the airbag control unit 110. The pressure sensor 113 has the function of detecting the internal pressures of the right airbag 30R, the center airbag 30C, and the left airbag 30L, respectively. The airbag control unit 110 can detect the input state of the load to each airbag based on the output of the pressure sensor 113.

[0023] The environment recognition unit 120 recognizes the environment around the host vehicle based on the outputs of various sensors. The environment recognition unit 120 has a function of recognizing various objects such as other vehicles, pedestrians, buildings, trees, terrain, etc. around the vehicle 1 (the host vehicle), and road shapes (lane shapes), etc. When a collision with an object such as another vehicle is inevitable (when the possibility of collision is equal to or greater than a predetermined value), the environment recognition unit 120 functions as a pre-crash determination unit that causes a pre-crash determination to hold. Connected to the environment recognition unit 120 are a stereo camera device 121, a millimeter-wave radar device 122, a laser scanner device 123, etc.

[0024] The stereo camera device 121 has a pair of cameras arranged at a predetermined interval (baseline length), and has a function of recognizing objects such as other vehicles, pedestrians, and bicycle riders, and detecting the relative position of the object 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 the captured image. For example, when the object is another vehicle, it has a function of recognizing the size of the other vehicle (such as whether it is a large vehicle that is significantly heavier than the vehicle 1, such as a truck, a bus, or a large SUV).

[0025] 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. The laser scanner device (LIDAR) 123 irradiates, for example, near-infrared laser light in pulses to scan the periphery of the vehicle 1, and has a function of 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 can recognize, for example, the collision form with an object (for example, the speed vector of the object with respect to the vehicle 1, the collision position with respect to the vehicle 1, etc.) and the attributes of the object (for example, when it is a vehicle, the vehicle type, vehicle shape, size, etc.) when a collision with an object such as another vehicle is inevitable (when the pre-crash determination is established). The environment recognition unit 120 has a function as a collision form prediction unit.

[0026] Next, the operation of the airbag device according to the embodiment will be described. FIG. 3 is a flowchart for explaining the operation at the time of collision of the airbag device according to the embodiment. Hereinafter, each step will be described in order.

[0027] <Step S 1 1: Pre-crash determination establishment judgment> The environment recognition unit 120 estimates the possibility of a collision with another vehicle (an example of an object in the present invention) approaching from the front of the vehicle 1 using known pre-crash determination logic, and determines whether the estimated possibility is equal to or greater than a preset threshold. If the possibility of a collision is equal to or greater than the threshold, the pre-crash determination is established assuming that the collision is inevitable, and the process proceeds to step S 1 2, and in other cases, a series of processes are terminated (returned).

[0028] <Step S 1 2: Collision form recognition> The airbag control unit 110 recognizes the collision form of the predicted other vehicle with respect to the vehicle 1. The recognition of the collision form can be performed, for example, based on information from the environment recognition unit 120. For example, based on the results of monitoring the relative position of another vehicle with respect to vehicle 1 before and after a collision by a stereo camera device 121, a millimeter-wave radar device 122, and a laser scanner device 123, the collision position of the other vehicle with respect to vehicle 1 (the range in which vehicle 1 receives the collision of the other vehicle), and the speed vector of the other vehicle with respect to vehicle 1 immediately before the collision are recognized. This speed vector includes information regarding the relative speed of the other vehicle with respect to vehicle 1 and the collision direction (angle). After that, step S 1 Proceeds to 3.

[0029] <Step S 1 3: Offset collision determination> The airbag control unit 110 determines whether the collision form recognized in step S 1 2 is a specific offset collision (including an oblique offset collision (oblique collision)) in which the reduction of collision damage is possible by the oblique surface formation control described later. For example, when the wrap rate is equal to or greater than a preset value, or when the relative speed vector of the other vehicle V with respect to vehicle 1 has a speed component equal to or greater than a preset value in the inward direction in the vehicle width direction of vehicle 1 (the direction approaching the center in the vehicle width direction of vehicle 1), it can be determined that it is a specific offset collision. If it is determined that it is a specific offset collision, proceed to step S 1 4, and in other cases, proceed to step S 1 5.

[0030] <Step S 1 4: Oblique surface formation control> The airbag control unit 110 executes an oblique surface formation control to form an oblique surface that is inclined with respect to the longitudinal direction of the vehicle body of vehicle 1 so as to gradually protrude outward in the vehicle width direction from the front side to the rear side of vehicle 1 by the surface of an airbag group including one of the right airbag 30R and the left airbag 30L and the center airbag 30C. The specific content of the oblique surface formation control will be described in detail later. After that, a series of processes are terminated.

[0031] <Step S1 5: Deployment of left and right airbags> The airbag control unit 110 deploys the right airbag 30R and the left airbag 30L. At this time, the center airbag 30 remains in the undeployed state. Also, the vent control valve 112 opens the vent flow paths of the right airbag 30R and the left airbag 30L. After that, a series of processes are terminated.

[0032] Hereinafter, the state and the operation and effect of the airbag device of the embodiment in each of the above-described airbag control modes will be described. FIG. 4 is a diagram schematically showing a state after a vehicle having the airbag device of the embodiment has collided with another vehicle in a full wrap collision. When the pre-crash determination is satisfied and the predicted collision mode is a full wrap collision, as shown in FIG. 1, the right airbag 30R and the left airbag 30L are deployed, and the center airbag 30C is in the undeployed state. Also, the vent flow paths of the right airbag 30R and the left airbag 30L are opened. As shown in FIG. 4, the other 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 exhausting the internal gas from the vent flow path, and absorb the collision energy.

[0033] Next, the specific content of the inclined surface portion formation control will be described. FIG. 5 is a diagram schematically showing a state immediately before a vehicle having the airbag device of the embodiment has collided with another vehicle in an oblique offset collision. When the pre-crash determination is satisfied and the predicted collision mode is a specific offset collision, the airbag control unit 110 first deploys only the center airbag 30C as shown in FIG. 5. The center airbag 30C passes through between the undeployed right airbag 30R and left airbag 30L and deploys and inflates toward the front side of the vehicle.

[0034] After the central airbag 30C is deployed, at a predetermined time interval, the airbag control unit 110 deploys the right airbag 30R and the left airbag 30L. FIG. 6 is a diagram schematically showing a state after a vehicle having the airbag device of the embodiment obliquely offset-collides with another vehicle and performs obliquely-facing portion formation control. The portions on the inner side in the vehicle width direction of the right airbag 30R and the left airbag 30L abut against the side surface portions of the central airbag 30C and press them, causing the side surface portions of the central airbag 30C to be recessed and the central airbag 30 to sink inward. The central airbag 30 is pressed by the right airbag 30R and the left airbag 30L at the intermediate portion in the front-rear direction and is recessed, thereby increasing the internal pressure. As a result, the front portion of the central airbag 30C expands so as to wrap around the front surface portion sides of the right airbag 30R and the left airbag 30L. At this time, the side surface portions at the front portion of the central airbag 30C, and the front surface portions and the side surface portions on the outer side in the vehicle width direction of the right airbag 30R and the left airbag 30L form an obliquely-facing portion S that is inclined with respect to the front-rear direction of the vehicle 1 so as to gradually protrude outward in the vehicle width direction from the front side to the rear side of the vehicle 1.

[0035] When a load F is input to the obliquely-facing portion S due to the collision of the other vehicle V, due to the inclination of the obliquely-facing portion S, a yaw moment is generated that turns the vehicle 1 to the side opposite to the collision side (the right side when the vehicle 1 is collided from the left side as shown in FIG. 7). Due to this yaw moment, the vehicle 1 starts to turn to the right as shown by the broken-line arrow. At this time, the other vehicle V starts to turn to the left as shown by the broken-line arrow and transitions from the state shown by the solid line to the state shown by the broken line. Thereafter, the vehicle 1 and the other vehicle V proceed while approaching each other with the front portions of their vehicle bodies in contact with each other. For example, in the example shown in FIG. 6, they proceed upward in FIG. 6.

[0036] As described above, according to the present embodiment, the following effects can be obtained. (1) By performing the inclined surface formation control prior to the occurrence of the offset collision, the input load F from the other vehicle V to each airbag is transmitted to the vehicle body via the inclined surface portion S, so that a yaw moment is generated to start turning the vehicle 1 to the side opposite to the side where the vehicle 1 has received the offset collision. As a result, the vehicle 1 turns to the side opposite to the collision side while accompanying the other vehicle V (the state of being close to each other), converts a part of the collision energy input from the other vehicle V into kinetic energy, reduces the amount of energy absorbed by the vehicle body structure, etc., and can reduce the collision damage of the vehicle 1. (2) When the lap rate predicted at the time of collision with the other vehicle V is equal to or higher than a predetermined threshold value, or when the relative velocity vector of the other vehicle V with respect to the vehicle 1 has a component in the direction approaching the center side in the vehicle width direction of the vehicle 1, by performing the inclined surface formation control, it is possible to effectively suppress the collision damage in a collision mode in which the collision damage reduction effect by the inclined surface formation control is large. In addition, in other collision modes, it does not prevent performing the deployment control of the airbag suitable for the collision mode. (3) In the case of a full lap collision or the like, by deploying the right airbag 30R and the left airbag 30L in a state of being in contact with or adjacent to each other at the center in the vehicle width direction, the other vehicle V colliding from the front side of the vehicle 1 can be stably received by the right airbag 30R and the left airbag 30L, and the collision energy can be effectively absorbed by the right airbag 30R and the left airbag 30L.

[0037] (Modification example) The present invention is not limited to the embodiments described above, and various modifications and changes 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 the above-described embodiments and can be changed as appropriate. For example, the structure, shape, material, manufacturing method, arrangement, number of each member and component constituting these, and the specific content of various controls are not limited to the embodiments and can be changed as appropriate. (2) The method for performing the pre-crash determination and the method for discriminating the collision mode are not limited to the methods of the embodiments and can be changed as appropriate. (3) The method of forming the inclined surface portion in the embodiment is an example and can be appropriately changed. For example, the shape, positional relationship, number of airbags, etc. that make up the inclined surface portion can be appropriately changed.

Explanation of Signs

[0038] 1 Vehicle 10 Passenger Compartment 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 Inclined Surface Portion

Claims

1. A first airbag that expands forward from the center in the vehicle width direction at the front of the vehicle body of the vehicle, A second airbag that expands forward from both left and right sides of the first airbag at the front of the vehicle body, A pre-crash determination unit that makes a pre-crash determination when the possibility of collision with an object is equal to or greater than a predetermined level, 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 An airbag device comprising: Having a collision form prediction unit that predicts the form of collision with the object, When the predicted collision form is a specific offset collision having a component in a direction in which the relative velocity vector of the object with respect to the vehicle approaches the center side in the vehicle width direction by a predetermined amount or more, the airbag deployment control unit deploys the first airbag and then deploys the second airbag so as to press and contact the side surface portion of the first airbag, and executes inclined surface portion formation control for forming an inclined surface portion in which the rear side of the vehicle protrudes outward in the vehicle width direction with respect to the front side of the vehicle by the surface portions of the first airbag and the second airbag An airbag device characterized by the above.

2. When the predicted collision form is a full wrap collision, the airbag deployment control unit does not deploy the first airbag and deploys the left and right second airbags in a state of being in contact with or adjacent to each other at the center in the vehicle width direction The airbag device according to claim 1, characterized by the above.

3. The specific offset collision is an oblique collision The airbag device according to claim 1 or claim 2, characterized by the above.

Images