Airbag device

Abstract

To provide an air bag device which suppresses damage of a pedestrian or the like.SOLUTION: An air bag device comprises: an air bag 30 which is developed from a vehicle body front part of a vehicle to a front side; a collision determination part 120 which establishes, when collision possibility is a prescribed threshold value or more, a pre-crash determination; an air bag development control part 110 which instructs an inflator 111 according to the pre-crash determination, and introduces development gas G into the air bag to develop the air bag; a vent control part 112 which opens and closes a vent passage discharging the development gas from the air bag; and an energy absorption state detection part which detects energy absorption state of the air bag. The vent control part lets the vent passage be open at the initial time of collision with a collision object, and then opening of the vent passage is decreased when the energy absorption state detection part detects that a prescribed energy absorption is completed.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] 2. Description of the Related Art In vehicles such as automobiles, it has been proposed to use airbags that deploy to the outside of the vehicle to reduce injury to pedestrians and the like in the event of a collision.

[0003] As an example of technology relating to such external airbag devices, Patent Document 1 describes how an airbag for protecting a cyclist is controlled so that the airbag comes into contact with the cyclist at a height that is symmetrical to the height of the collision position relative to the height of the cyclist's estimated center of gravity, thereby preventing the cyclist from being thrown up or knocked down by the collision with the airbag. Patent Document 2 describes an airbag device for protecting pedestrians in which multiple protective bags are arranged in the vehicle width direction at the front end of the vehicle body, and each protective bag is connected by a control bag that controls the inclination of adjacent protective bags, so that the multiple protective bags deploy to surround the pedestrian. Patent Document 3 describes a vehicle protection device for protecting pedestrians, which pops up the hood in the event of a collision, deploys an airbag toward the front of the vehicle body, and extends the face lower (the lower end of the front bumper face / air dam portion) forward to cause the pedestrian to fall onto the hood. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-218857 A [Patent Document 2] JP 2007-216933 A [Patent Document 3] JP 2020-23281 A Summary of the Invention [Problem to be solved by the invention]

[0005] 2. Description of the Related Art There is a demand for reducing damage to pedestrians and cyclists (hereinafter referred to as pedestrians and the like) in the event of a collision between a vehicle and the pedestrians and the like. An object of the present invention is to provide an airbag device which reduces damage to pedestrians and the like. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, an airbag device of the present invention is an airbag device including an airbag that deploys forward from a front part of a vehicle body, a collision determination unit that establishes a pre-crash determination when a collision possibility is equal to or greater than a predetermined threshold, an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the airbag and deploy the airbag, a vent control unit that opens and closes a vent flow path that discharges the deployment gas from within the airbag, and an energy absorption state detection unit that detects a state of energy absorption by the airbag, wherein the vent control unit opens the vent flow path in the early stage of a collision with an object to be hit, and thereafter reduces the opening of the vent flow path when the energy absorption state detection unit detects that a predetermined amount of energy absorption has been completed. The airbag device further includes a relative velocity detection unit that detects a relative velocity between the collision object and the vehicle body, and the vent control unit reduces the opening of the vent passage in response to the end of a predetermined energy absorption, and then increases the opening of the vent passage when the relative velocity becomes equal to or less than a predetermined threshold. Characterized by . According to this, by opening the vent passage at the beginning of a collision with a collision object (typically a human body such as a pedestrian or a cyclist), the airbag can be contracted while releasing deployment gas from the vent passage, thereby effectively absorbing energy. Thereafter, upon completion of a predetermined amount of energy absorption, the opening of the vent passage is reduced, thereby increasing the internal pressure of the airbag, pushing the impact object forward and accelerating it, thereby reducing the relative speed between the impact object and the vehicle body, and thereby minimizing damage to the impact object. In this specification and the claims, reducing the opening of the vent flow passage includes completely closing the vent flow passage, and reducing the opening of the vent flow passage from its previous state to a state where the vent flow passage is not closed. Also, According to this, after the relative speed between the collision object and the vehicle body becomes sufficiently small, the vent passage is opened to reduce the internal pressure of the airbag and soften the airbag, thereby inducing the collision object to lean against the vehicle body or to ride up onto the hood of the vehicle body.

[0008] In order to solve the above-mentioned problems, an airbag device of the present invention is an airbag device including an airbag that deploys forward from a front part of a vehicle body, a collision determination unit that establishes a pre-crash determination when a collision possibility is equal to or greater than a predetermined threshold, an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the airbag and deploy the airbag, a vent control unit that opens and closes a vent flow path that discharges the deployment gas from within the airbag, and an energy absorption state detection unit that detects a state of energy absorption by the airbag, wherein the vent control unit opens the vent flow path in the early stage of a collision with an object to be hit, and thereafter reduces the opening of the vent flow path when the energy absorption state detection unit detects that a predetermined amount of energy absorption has been completed. The inflator additionally supplies the deployment gas to the inside of the airbag after the vent control unit reduces the opening of the vent passage in response to the end of a predetermined energy absorption. Characterized by . According to this, by opening the vent passage at the beginning of a collision with a collision object (typically a human body such as a pedestrian or a cyclist), the airbag can be contracted while releasing deployment gas from the vent passage, thereby effectively absorbing energy. Thereafter, upon completion of a predetermined amount of energy absorption, the opening of the vent passage is reduced, thereby increasing the internal pressure of the airbag, pushing the impact object forward and accelerating it, thereby reducing the relative speed between the impact object and the vehicle body, and thereby minimizing damage to the impact object. Also, This can increase the internal pressure of the airbag to enhance the effect of accelerating the object of collision, thereby enhancing the above-mentioned effects.

[0009] In the present invention, the vent control unit can reduce the opening degree of the vent passage compared to the opening degree at the initial stage of the collision, after the pre-crash determination is established and until the deployment of the airbag is completed. Typically, the vent passages can be closed until airbag deployment is complete. According to this, by reducing the opening of the vent passage during deployment of the airbag to suppress the outflow of deployment gas, the deployment of the airbag can be completed quickly. Effect of the Invention

[0010] As described above, according to the present invention, it is possible to provide an airbag device that reduces injury to pedestrians and the like. [Brief description of the drawings]

[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, in which a vehicle is viewed from above when an airbag is deployed; FIG. [Diagram 2] FIG. 2 is a view taken along the line II-II of FIG. [Diagram 3] 1 is a block diagram showing a schematic configuration of a system for controlling an airbag device according to an embodiment; [Figure 4] 5 is a flowchart illustrating an operation of the airbag device of the embodiment during a collision. [Diagram 5] 1 is a diagram showing a schematic diagram of a state immediately after a vehicle having an airbag device according to an embodiment collides with a pedestrian; [Figure 6] 1 is a diagram showing a state immediately after a vehicle having an airbag device according to an embodiment collides with a pedestrian and energy absorption is completed; [Figure 7] 1 is a diagram showing a state after a vehicle having an airbag device according to an embodiment collides with a pedestrian and the relative speed between the pedestrian and the vehicle body becomes equal to or lower than a predetermined threshold. FIG. 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, for example, in the front of a vehicle such as a passenger car, and is intended to provide protection (reduction of damage) in the event of a collision with a human body such as a pedestrian or a bicycle rider. FIG. 1 is a diagram showing a schematic configuration of an airbag device according to an embodiment, and shows a state in which an airbag is deployed as viewed from above a vehicle. FIG. 2 is a view taken along the line II-II of FIG. The vehicle 1 has, for example, a so-called two-box vehicle shape having an engine compartment 20 that protrudes forward from a passenger compartment 10 .

[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, a front hood 24, 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 accommodates a strut of a MacPherson strut type front suspension are attached. The front side frame 21 is formed by assembling and welding members formed by press-molding steel plates, for example, so that its cross-sectional shape when viewed from the vehicle front-rear direction is a rectangular closed cross-section.

[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 an airbag 30 (described later) from a human body or object that it collides with, via the front side frames 21, to the rear side of the vehicle body.

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

[0018] The airbag device of the embodiment includes an airbag 30 which will be described below. The airbag 30 is formed into a bag shape by joining panels made of a base fabric such as nylon 66 fabric. The airbag 30 is deployed and further inflated by introduction of deployment gas generated by an inflator 111 in response to the establishment of a pre-crash determination, which will be described later.

[0019] The airbag 30 is normally stored inside the front bumper 23 in a folded state (before the pre-crash determination is established). In the event of a collision, the airbag 30 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.

[0020] The airbag 30 is provided with a vent hole 31. The vent hole 31 is a vent passage that releases the deployment gas G from the inside of the airbag 30 to the outside. The opening degree of the vent hole 31 can be controlled by a vent control valve 112 which will be described later.

[0021] FIG. 3 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 comprises an airbag control unit 110, an environment recognition unit 120, a braking 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.

[0022] The airbag control unit 110 issues commands to and controls an inflator 111 and a vent control valve 112 to inflate the airbag 30 and control the state of the airbag 30 being inflated. The airbag control unit 110 functions as the airbag deployment control unit of the present invention. The inflator 111 is a chemical (pyrotechnic) gas generating device that generates a deployment gas G for deploying the airbag 30 in response to a command from the airbag control unit 110. The inflator 111 is a so-called multi-stage inflator that can generate the deployment gas G multiple times in response to a command from the airbag control unit 110.

[0023] The vent control valve 112 opens and closes the vent hole 31 for discharging the deployment gas G from within the airbag 30 (for example, opening it to the atmosphere) in response to a command from the airbag control unit 110. The vent control valve 112 may, for example, comprise a solenoid valve. The vent control valve 112 has a function of varying the opening degree of the vent hole 31 continuously or stepwise in response to a command from the airbag control unit 110 . Airbag control unit 110 and vent control valve 112 cooperate to function as the vent control portion of the present invention.

[0024] The airbag control unit 110 is provided with a pressure sensor 113 . The pressure sensor 113 has a function of detecting the pressure (internal pressure) of the deployment gas G inside the airbag 30. The airbag control unit 110 can detect the state of the load input to the airbag 30 and the state of the absorption of the collision energy based on the output of the pressure sensor 113. The airbag control unit 110 cooperates with the pressure sensor 113 to function as an energy absorption state detection unit of the present invention.

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

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

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

[0028] The brake control unit 130 controls the braking force of the hydraulic service brakes provided on each wheel of the vehicle 1 . A hydraulic control unit 131 is connected to the brake control unit 130 . The hydraulic control unit 131 has a function of individually controlling the wheel cylinder hydraulic pressure that generates the braking force for each wheel. The hydraulic control unit 131 is configured to have, for example, an electric pump that pressurizes the brake fluid, and electromagnetic valves such as a pressure increase valve, a pressure reduction valve, and a pressure maintenance valve that control the hydraulic pressure of each wheel cylinder.

[0029] The brake control unit 130 has functions to perform, for example, anti-lock brake control that periodically reduces the wheel cylinder hydraulic pressure of a locked wheel when the brakes are locked to restore rotation of the wheel, and behavior control that generates a yaw moment that generates a braking force difference between the left and right wheels to suppress each behavior when understeer or oversteer behavior occurs. Furthermore, the brake control unit 130 has a function of automatically generating a braking force to decelerate the vehicle 1 and reduce collision damage when the environment recognition unit 120 establishes a pre-crash determination.

[0030] Next, the operation of the airbag device of the embodiment will be described. FIG. 4 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> The environment recognition unit 120 uses known pre-crash judgment logic to estimate the possibility of a collision between the vehicle 1 and a collision object approaching from the front of the vehicle 1, such as a pedestrian or a cyclist, and determines whether the estimated possibility is equal to or exceeds a preset threshold. If the possibility of a collision occurring is equal to or greater than the threshold, it is determined that a collision is unavoidable, a pre-crash determination is established, and the process proceeds to step S02; otherwise, the series of processes ends.

[0032] <Step S02: Airbag deployment begins / vent control valve close> The airbag control unit 110 issues a command to the inflator 111 to generate and introduce the deployment gas G into the airbag 30, thereby starting the deployment of the airbag 30. At this time, the airbag control unit 110 closes the vent control valve 112 in order to quickly deploy the airbag 30. Then, proceed to step S03.

[0033] <Step S03: Pre-crash brake activation> In response to the establishment of the pre-crash determination, the brake control unit 130 causes the hydraulic control unit 131 to generate wheel cylinder hydraulic pressure in each wheel, and starts braking and decelerating the vehicle 1 using the service brakes. This braking can continue, for example, until the vehicle 1 comes to a stop. Then, proceed to step S04.

[0034] <Step S04: Determining whether airbag deployment is complete> The airbag control unit 110 determines whether the airbag 30 has expanded to a predetermined volume based on the output of the pressure sensor 113 or the like. If it is determined that the airbag 30 has been deployed to the predetermined volume, it is assumed that the deployment of the airbag 30 has been completed and the process proceeds to step S05; otherwise, step S04 is repeated.

[0035] <Step S05: Open the vent control valve> The airbag control unit 110 issues a command to the vent control valve 112 to open the vent hole 31 . As a result, when a collision occurs and a colliding object (such as a pedestrian) presses against the airbag 30, the airbag 30 contracts while discharging the deployment gas G from the vent hole 31, thereby absorbing the energy of the collision. Then, proceed to step S06.

[0036] <Step S06: Determining the End of Initial Energy Absorption (EA)> The airbag control unit 110 detects the contraction state of the airbag 30 based on, for example, the change in the internal pressure of the airbag 30 detected by the pressure sensor 113, and determines whether or not a predetermined initial energy absorption by the airbag 30 has been completed. The contracted state of the airbag 30 at which it is determined that initial energy absorption has ended can be set, for example, taking into consideration that when the vent hole 31 is closed by the vent control valve 112 and the internal pressure of the airbag 30 is increased to push a pedestrian, etc., toward the front of the vehicle, the pedestrian, etc. will not suffer significant injury and will not be thrown toward the front of the vehicle by the rebound force of the airbag 30. If the airbag 30 has deflated to such an extent that it can be determined that the initial energy absorption has been completed, the process proceeds to step S07; otherwise, step S06 is repeated.

[0037] <Step S07: Close the vent control valve> The airbag control unit 110 issues a command to the vent control valve 112 to close the vent hole 31 . As a result, the airbag 30 is pressed and compressed by the pedestrian or the like, and the internal pressure increases. At this time, if the internal pressure of the airbag 30 detected by the pressure sensor 113 is equal to or lower than a predetermined value, the expansion gas G may be additionally supplied from the multi-stage inflator 111 to increase the internal pressure of the airbag 30. Then, proceed to step S08.

[0038] <Step S08: Collision object-vehicle relative speed determination> The environment recognition unit 120 detects the behavior of the collision object relative to the vehicle 1 (particularly, the relative speed with respect to the vehicle body) by using, for example, a stereo camera device 121 or the like. The airbag control unit 110 determines whether or not the relative speed of the object to be hit with respect to the vehicle body detected by the environment recognition unit 120 is equal to or lower than a preset threshold value. If the relative speed becomes equal to or less than the threshold (typically immediately before the ground speed of the collision object becomes equal to the traveling speed of the vehicle 1), the process proceeds to step S09, and otherwise step S08 is repeated.

[0039] <Step S09: Open the vent control valve> The airbag control unit 110 issues a command to the vent control valve 112 to open the vent hole 31 . As a result, the airbag 30 contracts while releasing the deployment gas G from the vent hole 31. Then, the series of processes ends.

[0040] Hereinafter, a state transition during a pedestrian collision and the operation and effect of the airbag device of the embodiment will be described. First, in response to the establishment of a pre-crash determination with respect to a pedestrian or the like, the airbag 30 deploys to the state shown in FIG. 1 and FIG. After deployment to this state, the vent hole 31 is opened by the vent control valve 112.

[0041] FIG. 5 is a schematic diagram showing a state immediately after a vehicle having the airbag device of the embodiment collides with a pedestrian. In the early stage of the collision, a collision with a pedestrian P occurs and the airbag 30 is compressed, causing a part of the deployment gas G inside the airbag 30 to be released to the outside through the vent hole 31. As a result, the airbag 30 absorbs a portion of the collision energy input from the pedestrian P while contracting. Thereafter, when it is determined that a predetermined amount of initial energy absorption has been completed, the vent hole 31 is closed by the vent control valve 112 .

[0042] FIG. 6 is a diagram showing a state immediately after a vehicle having the airbag device of the embodiment collides with a pedestrian and energy absorption is completed. In FIG. 6, the outline of the airbag 30 before it is deflated is shown by a dashed line. In this state, the vent hole 31 is closed by the vent control valve 112, and the internal pressure of the airbag 30 is increased by introducing additional deployment gas G from the inflator 111 as required. The airbag 30 presses the pedestrian P toward the front of the vehicle, accelerating the ground speed of the pedestrian P. On the other hand, since the vehicle 1 is decelerated by the pro-crash brake control, in this state the relative speed between the pedestrian P and the vehicle body gradually decreases. Thereafter, when the relative speed becomes equal to or lower than a predetermined threshold value, the vent hole 31 is opened by the vent control valve 112 .

[0043] FIG. 7 is a diagram showing a state after a vehicle having the airbag device of the embodiment collides with a pedestrian and the relative speed between the pedestrian and the vehicle body becomes equal to or lower than a predetermined threshold. By opening the vent hole 31, the airbag 30 contracts while releasing the deployment gas G from the vent hole 31. As a result, the pedestrian P leans against the vehicle body and is then scooped up onto the front hood 24.

[0044] As described above, according to this embodiment, the following effects can be obtained. (1) By opening the vent hole 31 at the beginning of a collision with a collision object such as a pedestrian P, the airbag 30 can be contracted while releasing the deployment gas G from the vent hole 31, thereby effectively absorbing energy. Thereafter, upon completion of a predetermined amount of initial energy absorption, the vent hole 31 is closed, thereby increasing the internal pressure of the airbag 30 and pushing the pedestrian P, etc. forward, accelerating the pedestrian P, etc., thereby reducing the relative speed between the pedestrian P, etc. and the vehicle body, thereby minimizing damage to the pedestrian P, etc. (2) After the relative speed between the pedestrian P, etc. and the vehicle body becomes sufficiently small, the vent hole 31 is opened to reduce the internal pressure of the airbag 30 and soften the airbag 30, thereby inducing the pedestrian P, etc. to lean against the vehicle body or climb onto the front hood 24 of the vehicle body. (3) When the airbag 30 is used to push a pedestrian P, etc., forward and accelerate the pedestrian P, by additionally supplying the deployment gas G from the inflator 111, the internal pressure of the airbag 30 can be increased, thereby enhancing the effect of accelerating the object of collision, and thus promoting the above-mentioned effects. (4) After the pre-crash determination is made, the vent hole 31 is kept closed until the deployment of the airbag 30 is completed. This prevents the outflow of the deployment gas G during the deployment of the airbag 30, thereby enabling the airbag 30 to quickly complete deployment.

[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 embodiments and may be modified as appropriate. For example, the structure, shape, material, manufacturing method, arrangement, and number of each member and part that constitutes these, as well as the specific content of various controls, are not limited to those in the respective embodiments and can be changed as appropriate. (2) The method of performing the pre-crash determination and the method of determining the type of collision are not limited to the methods described in the respective embodiments and may be modified as appropriate. (3) In the embodiment, the end of the predetermined energy absorption by the airbag is determined based on the internal pressure of the airbag, but the determination may be made by other methods. For example, the end of the predetermined energy absorption may be determined based on the contraction stroke of the airbag after the occurrence of a collision or the elapsed time after the occurrence of a collision. For example, the behavior of the impact object after the impact with the airbag may be monitored to recognize the state of energy absorption. (4) In the embodiment, the vent passage (vent hole) is controlled to be opened and closed sequentially after the collision, but the present invention is not limited to this. For example, the vent passage may be opened and the opening degree may be increased or decreased. For example, instead of closing the vent passage, the vent passage may be opened and opened to a low degree. [Explanation of symbols]

[0046] 1 car 10 compartments 20 Engine compartment 21 Front side frame 22 Bumper beam 23 Front bumper 24 Front hood 30 Airbag 31 Vent Hole 110 Airbag Control Unit 111 Inflator 112 Vent control valve 113 Pressure sensor 120 Environmental recognition unit 121 Stereo camera device 122 Millimeter wave radar device 123 Laser scanner device 130 Brake control unit 131 Hydraulic control unit G Deployment gas P Pedestrian

Claims

1. An airbag that deploys forward from a front part of a vehicle body, a collision determination unit that establishes a pre-crash determination when the possibility of a collision is equal to or greater than a predetermined threshold; an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the airbag and deploy the airbag; a vent control unit that opens and closes a vent passage that discharges the deployment gas from within the airbag; an energy absorption state detection unit that detects an energy absorption state of the airbag; An airbag device comprising: the vent control unit opens the vent passage at an early stage of a collision with a collision object, and thereafter reduces an opening degree of the vent passage when the energy absorption state detection unit detects that a predetermined amount of energy absorption has been completed; The airbag device further includes a relative speed detection unit that detects a relative speed between the collision object and a vehicle body, The vent control unit reduces the opening degree of the vent passage in response to completion of a predetermined energy absorption, and then increases the opening degree of the vent passage when the relative speed becomes equal to or lower than a predetermined threshold value. An airbag device comprising:

2. An airbag that deploys forward from a front part of a vehicle body, a collision determination unit that establishes a pre-crash determination when the possibility of a collision is equal to or greater than a predetermined threshold; an airbag deployment control unit that issues a command to an inflator in response to the pre-crash determination to supply deployment gas to the airbag and deploy the airbag; a vent control unit that opens and closes a vent passage that discharges the deployment gas from within the airbag; an energy absorption state detection unit that detects an energy absorption state of the airbag; An airbag device comprising: the vent control unit opens the vent passage at an early stage of a collision with a collision object, and thereafter reduces an opening degree of the vent passage when the energy absorption state detection unit detects that a predetermined amount of energy absorption has been completed; The inflator additionally supplies the deployment gas to the inside of the airbag after the vent control unit reduces the opening of the vent passage in response to completion of a predetermined energy absorption. An airbag device comprising:

3. The vent control unit reduces the opening of the vent passage from the establishment of the pre-crash determination until the completion of deployment of the airbag to the opening at the initial stage of the collision.

3. The airbag device according to claim 1 or 2,

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