AIRBAG DEVICE

Abstract

The separation speed of a driver can be easily reduced with the help of an airbag. An airbag device (40) mounted on a vehicle (10) and provided with an airbag (42) that deploys circumferentially around a driver, comprising: a detachment unit (43) that detaches the airbag (42) from the vehicle (10); a detection unit (44C) that detects an elapsed time from the deployment of the airbag (42); and a detachment control unit (44D) that causes the detachment unit (43) to detach the airbag (42) in a case where a predetermined condition is satisfied, including a first condition that the elapsed time detected by the detection unit (44C) exceeds a time threshold.

Description

Technical FieldThe present invention relates to an air bag apparatus.BackgroundThere has been proposed a saddle riding vehicle including an airbag device including an airbag that deploys circumferentially around the rider (e.g., Patent Literature 1). Patent Literature 1 discloses a structure in which an airbag is supported by a slide frame, wherein in the case where the impact is large at the time of the collision, the slide frame slides forward and is separated from a guide rail, so that the rider is separated from the motorcycle while being restrained by the airbag.List of Citer ListsPatent LiteraturePatent Literature 1: JP 10-006901 ASUMMARY OF THE INVENTIONTechnical ProblemIn the prior art configuration, the impact is absorbed by the slide frame, but the speed (separating speed) at which the driver is separated from the vehicle at the time of the impact is not decreased by the airbag.The present invention has been made in view of the above circumstances, and an object of the present invention is to facilitate the reduction of a separation speed of a driver using an airbag.Solution of the ProblemAn airbag device mounted on a vehicle and provided with an airbag deployed circumferentially around a driver includes: a separation unit that separates the airbag from the vehicle; and an airbag control unit that detects an elapsed time from the deployment of the airbag and causes the separation unit to separate the airbag in a case that a predetermined condition including the elapse of a predetermined time is satisfied.Advantageous Effects of the InventionThe separating speed of a driver can be easily reduced with an airbag.Brief Description of the DrawingsFIG. 1 is a side view of a saddle riding vehicle according to an embodiment of the present invention. FIG. 2 is a block diagram of an airbag device. FIG. 3 is a left side view showing a state in which an airbag deploys for protecting a driver. FIG. 4 is a front view showing the state in which the airbag deploys for protecting the driver. FIG. 5 is a flowchart showing the operation of an airbag control unit. FIG. 6 is a flowchart showing an example of the process after step S 2 of the flowchart of FIG. 5. FIG. 7 is a sequence diagram showing the deployment timing of the airbag at least in a frontal impact. FIG. 8 is a sequence diagram showing the deployment timing of the airbag in a rear or side impact. FIG. 9 is a side view showing an airbag device according to a modification example together with a saddle riding vehicle. FIG. 10 is a left side view showing a state in which the airbag shown in FIG. 9 is deployed for protecting a driver. FIG. 11 is a block diagram showing a modification example of the airbag device.DESCRIPTION OF EMBODIMENTSAn embodiment of the present invention will be described below with reference to the drawings. Unless otherwise specified, the directions including front-rear, left-right, and up-down indicated in the specification are the same as those directions with respect to a vehicle body. Reference numerals FR, UP and LH shown in the drawings indicate a front side of the vehicle body, an upper side of the vehicle body and a left side of the vehicle body, respectively.[Embodiment]FIG. 1 is a side view of a saddle riding vehicle 10 according to an embodiment of the present invention.The saddle riding vehicle 10 is a vehicle including a vehicle body frame 11, a drive unit 12 supported on the vehicle body frame 11, a front fork 14 supporting a front wheel 13 in a steerable manner, a swing arm 16 supporting a rear wheel 15, and a seat 17 for a driver.The saddle riding vehicle 10 is a vehicle on which the rider sits astride the seat 17. The seat 17 is provided over a rear part of the vehicle body frame 11.The vehicle body frame 11 includes a head pipe 18 provided at a front end portion of the vehicle body frame 11, a front frame 19 located at a rear side of the head pipe 18, and a rear frame 20 located at a rear side of the front frame 19. A front end portion of the front frame 19 is connected to the head pipe 18.The seat 17 is fixed to the rear frame 20.The front fork 14 is supported on the head pipe 18 so as to be capable of being steered leftward and rightward. The front wheel 13 is supported on an axle 13a disposed at a lower end portion of the front fork 14. A steering handle 21 for steering which the rider grasps is disposed at the upper end portion of the front fork 14.The swing arm 16 is supported on a pivot shaft 22 supported on the vehicle body frame 11. The pivot shaft 22 is a shaft extending horizontally in a vehicle width direction. The pivot shaft 22 passes through a front end portion of the swing arm 16.The rear wheel 15 is supported on an axle 15a disposed at a lower end portion of the swing arm 16.The drive unit 12 is disposed between the front wheel 13 and the rear wheel 15 and is supported on the vehicle body frame 11.The drive unit 12 is an internal combustion engine. The power unit 12 includes a crankcase 23 and a cylinder 24 that receives a reciprocating piston. An exhaust device 25 is connected to an exhaust port of the cylinder 24.An output of the drive unit 12 is transmitted to the rear wheel 15 via a driving force transmission member that connects the drive unit 12 and the rear wheel 15 to each other.The saddle riding vehicle 10 further includes a front fender 26 covering the front wheel 13 from above, a rear fender 27 covering the rear wheel 15 from above, foot pads 28 on which the rider places his or her feet, and a fuel tank 29 storing fuel to be used by the power unit 12.The front fender 26 is attached to the front fork 14. The rear fender 27 and the foot pads 28 are provided at a lower side with respect to the seat 17. The fuel tank 29 is supported on the vehicle body frame 11.The saddle riding vehicle 10 is a scooter type motorcycle having a footrest 28 in front of and below the seat 17. the power unit 12 is a unit swing engine in which the internal combustion engine and the swing arm 16 are integrally formed. The drive unit 12 is disposed immediately below the seat 17 and the rear frame 20.The saddle riding vehicle 10 also includes a body cover 30 that covers the vehicle body, such as the vehicle body frame 11 and the power unit 12.The seat 17 is disposed behind the handlebar 21 and above the rear frame 20. The seat 17 includes a front seat 31 on which a driver R sits, and a rear seat 32 disposed behind the front seat 31.The rear seat 32 is located higher in a step shape than the front seat 31. a passenger (social) may be seated on the rear seat 32, or luggage may be positioned on the rear seat 32.The saddle riding vehicle 10 includes an airbag device 40 that protects the rider R.FIG. 2 is a block diagram of the airbag device 40.The airbag device 40 includes an inflator 41, an airbag 42 inflated with a gas discharged from the inflator 41, a partition unit 43 that partitions the airbag 42 from the saddle riding vehicle 10, an airbag control unit 44 that controls the operation of the airbag device 40, and a storage unit 45.The inflator 41 discharges a gas into the airbag 42 under the control of the airbag control unit 44. The airbag 42 has been formed by sewing a base fabric and inflates and deploys by the pressure of the gas. The airbag 42 is accommodated in an airbag housing unit 33 (FIG. 1 ) in the folded state.The airbag housing unit 33 is located in a rear part of the seat 17 and is disposed behind the front seat 31 and thus behind a seating position 17 aof the driver R. That is, the body support position of the airbag 42 is behind the driver R.The separation unit 43 separates the airbag 42 from the saddle riding vehicle 10. In the example shown in FIG. 1, the separation unit 43 separates an airbag part protecting the rider R by the airbag 42 from the saddle riding vehicle 10. Therefore, in a case where the rider R is separated from the saddle riding vehicle 10, it is expected that the impact acting on the rider R is alleviated after the separation. The separation unit 43 may be used for separating all or part of the airbag 42 in any configuration. The part of the airbag to be separated may include the inflator 41.The airbag control unit 44 controls the units of the airbag device 40 and inputs detection results of a vehicle sensor 10S. The vehicle sensor 10S is a sensor group that detects information indicating front, rear, left, and right accelerations (including decelerations) of the saddle riding vehicle 10, a vehicle speed, an inclination angle, a pitch angle, a yaw angle, and the like. The inclination angle is an inclination angle of the vehicle body with respect to the vertical direction, and the closer the inclination angle is 90°, the closer the side surface of the saddle riding vehicle 10 is to the road surface.The vehicle sensor 10S includes, for example, a vehicle speed sensor, a rotational speed sensor for the front and rear wheels, and an inertial sensor such as an inertial measurement unit (IMU). The inertial sensor detects front, rear, left and right accelerations, a triaxial angular velocity, and the like. By performing a predetermined conversion of the triaxial angular velocity, the roll angle, the pitch angle, and the yaw angle of the saddle-riding vehicle 10 can be determined, and the pitch angle of the saddle-riding vehicle 10 can be determined from the roll angle. The roll angle is, for example, an inclination angle to a road surface, whereas the inclination angle of the saddle riding vehicle 10 is an inclination angle of the saddle riding vehicle 10 to the left and right with respect to the vertical axis.The airbag control unit 44 is composed of a CPU and peripheral circuits, and functions as a collision determination unit 44A, a deployment control unit 44B, a detection unit 44C, and a detachment control unit 44D when the CPU executes a control program stored in the storage unit 45. The collision determination unit 44A determines whether a collision of the saddle riding vehicle 10 has occurred, or determines a collision direction (front collision (also referred to as a front collision), rear collision (also referred to as a rear collision or a rear collision), and side collision (also referred to as a side collision)) based on the detection results (for example, acceleration in the longitudinal direction and acceleration in the lateral direction of the saddle riding vehicle 10) of the vehicle sensor 10S.In a case where the inclination angle and / or angular velocity of the saddle riding vehicle 10 for prediction of a camber satisfies a predetermined condition, the collision determination unit 44A of the present embodiment determines that a camber is predicted.For example, a predetermined condition describing a combination of an inclination angle and an angular velocity in a case where it is assumed that a camber occurs is set, and the collision determination unit 44A performs a process of determining that a camber is predicted in a case where a combination of the detected inclination angle and the angular velocity satisfies the predetermined condition. More specifically, map data in which a threshold value of angular velocity is set for each inclination angle is prepared in advance as a predetermined condition, and the collision determination unit 44A performs a process of determining that a camber is predicted in a case where the detected angular velocity is equal to or greater than the threshold value of angular velocity set from the map data based on the detected inclination angle.The process is not limited to a process using a combination of the inclination angle and the angular velocity. For example, in a case where it is assumed that a fall occurs, a threshold value of an inclination angle, or in a case where it is assumed that a fall occurs, a threshold value of an angular velocity may be set, and the collision determination unit 44A may perform a process of determining that a fall is predicted in the case where the inclination angle or the angular velocity is equal to or greater than the threshold value.The deployment control unit 44B determines whether to operate the inflator 41 based on the determination result of the collision determination unit 44A, and operates the inflator 41 according to the determination result to deploy the airbag 42.The acquisition unit 44C acquires various kinds of information regarding a detachment timing at which the airbag 42 is detached from the saddle riding vehicle 10. The information to be acquired includes an elapsed time TA (hereinafter referred to as "airbag deployment time TA") from deployment of the airbag 42 and a moving distance LA (hereinafter referred to as "driver moving distance LA") of the driver R with respect to the saddle-riding vehicle 10.The detection unit 44C has a time measurement function and detects the airbag deployment time TA by measuring the elapsed time from deployment of the inflator 41.Moreover, the detection unit 44C detects, via the vehicle sensor 10S, front, rear, left, and right accelerations of the saddle-riding vehicle 10, and performs an arithmetic process to estimate the driver's moving distance LA based on the accelerations, thereby detecting the driver's moving distance LA.The method for calculating the moving distance LA of the driver will be described below.The moving distance of the saddle riding vehicle 10 can be calculated by integrating the second-order acceleration measured by the vehicle sensor 10S. In a case where a collision of the saddle riding vehicle 10 does not occur, the saddle riding vehicle 10 and the rider R integrally move.Since the moving distance LA of the driver is used in the current calculation, instead of a constant integral value output of the acceleration sensor detecting the acceleration, an integral value obtained by removing a DC component of the output of the acceleration sensor or an integral value for a certain period of time is used.Meanwhile, in a case where a collision of the saddle riding vehicle 10 occurs, the rider R attempts to continue the inertial movement even when the saddle riding vehicle 10 is decelerated due to the collision, because the rider R is not restrained by the saddle riding vehicle 10. Therefore, it is conceivable that the amount of movement of the driver R approaches the amount of movement of the saddle riding vehicle 10 in a case where no collision with the vehicle body occurs.Therefore, for the driver's moving distance LA, an estimated value can be calculated by calculating the difference in the moving distance of the saddle-riding vehicle 10 between the case where the vehicle does not decelerate without collision and the case where the vehicle decelerates due to the collision, based on the acceleration from the time of the collision. The driver's moving distance LA is a moving distance with respect to the saddle riding vehicle 10 from the time of collision.Based on the detection results of the detection unit 44C and the detection results of the vehicle sensor 10S, the detachment control unit 44D actuates the detachment unit 43 after the deployment of the airbag 42 starts, thereby detaching the airbag 42. In a case where a collision of the saddle riding vehicle 10 occurs, the airbag 42 may be separated and separated from the saddle riding vehicle 10 together with the rider R.FIG. 3 is a left side view showing a state in which the airbag 42 deploys to protect the driver R. FIG. 4 is a front view showing the state in which the airbag 42 deploys to protect the driver R.The airbag 42 includes a vehicle-body-side deployment portion 49 positioned at the time of deployment on the rear side of the driver R, which is the body support position (may also be referred to as the inflator 41 side or the airbag housing unit 33 side), and an opposing deployment portion 50 positioned at the time of deployment on the front side of the driver R, which is the opposing side of the body support position.The vehicle body side deploying portion 49 functions as a rear cover portion that covers the body R 1 of the driver R from behind, and has a shape that extends upward from the airbag housing unit 33. Moreover, the opposing deployment portion 50 functions as a front cover portion that covers the body R 1 from the front, and has a shape that extends upward to the vicinity of a head R 2 of the driver R.The opposing deploying portion 50 includes a front extending portion 51 that extends forward from both side portions of the vehicle body side deploying portion 49 on the vehicle width direction outer side, and an inward bent portion 52 that is bent inward from the front extending portion 51 in the vehicle width direction and extends inward in the vehicle width direction. Further, the opposing deploying portion 50 includes a downward extending portion 53 bent downward from the inward bent portion 52 and extending downward, and a folding portion 54 folded back from the downward extending portion 53 toward the front extending portion 51. The front extension portion 51 covers the body R 1 from the outside under an arm R 3 of the driver R and protects the body R 1 from the outside. Therefore, the opposing deployment region 50 covers the body R 1 of the driver R from the front, as well as from the left and right.Since the deploying airbag 42 circumferentially covers the driver R, the driver R can be protected from the front as well as from the left, right, and rear. The airbag 42 is mounted on the saddle riding vehicle 10 behind the rider R. Accordingly, in a case where a front impact occurs, that is, in a case where an inertial force F (FIG. 3 ) that moves the driver R toward the front of the saddle riding vehicle 10 is generated as shown in the example in FIG. 3, the forward movement speed of the driver R with a tension FT of the airbag 42 can be reduced by delaying the separation of the airbag 42.Moreover, even in a case where an inertial force F is generated that moves the rider R to the saddle riding vehicle 10 side, the lateral moving speed of the rider R can be reduced to some extent with a tension FT of the airbag 42. Since the airbag 42 covers the rider R also from behind, even in a case where an inertial force F is generated that urges the rider R toward the rear of the saddle riding vehicle 10, the rearward movement speed of the rider R can be reduced with a tension FT of the airbag 42 to some extent.As described above, in a case where the rider R moves back and forth and right and left, the rider R and the saddle riding vehicle 10 are connected via the airbag 42, so that the relative movement of the rider R with respect to the saddle riding vehicle 10 is suppressed, and the moving speed of the rider R can thus be reduced. Also, since the moving speed of the rider R is reduced, the separating speed can be reduced in a case where the rider R is separated from the saddle riding vehicle 10.FIG. 5 is a flowchart showing the operation of the airbag control unit 44.As shown in FIG. 5, the airbag control unit 44 causes the collision determination unit 44A to determine whether a collision or a fall is predicted based on the detection results of the vehicle sensor 10S (step S 1).When neither a collision nor a fall is predicted (step S 1: NO), the airbag control unit 44 ends the flowchart shown in FIG. 5. This flow chart is repeatedly executed at predetermined intervals, wherein it is continuously monitored whether a collision or a fall is predicted.In a case where a collision or a camber is predicted (step S 1: YES), that is, in a case where a calculated acceleration of the saddle riding vehicle 10 is equal to or greater than a predetermined threshold or at least the inclination angle or the angular velocity satisfies a predetermined condition for the prediction of a camber, the airbag control unit 44 causes the deployment control unit 44B to operate the inflator 41 (step S 2). In the case of a light impact or a low-speed impact in which the air bag 42 does not function effectively, the inflator 41 is not operated as before. In the context of the present invention, impact and fall means an impact and fall in which, unless otherwise described, the airbag 42 functions effectively.Next, the airbag control unit 44 causes the detachment control unit 44D to determine whether a preset condition for early detachment is satisfied (step S 3). The early separation condition is a condition indicating a situation in which it is desirable to separate the airbag 42 earlier than a case in which the airbag 42 is separated by the maximum deceleration separation process to be described later. The early separation condition may also be referred to as a condition describing a situation where it is desirable to separate the airbag 42 before the airbag 42 fully deploys with a necessary and sufficient capacity.The state in which the airbag 42 is fully deployed is a state in which the airbag 42 is deployed to the maximum capacity.In the present embodiment, the early separation condition represents a condition indicating a state in which the saddle-riding vehicle 10 is likely to crash or a state in which the saddle-riding vehicle 10 is immediately in a high-speed traveling state. The early separation condition is stored in the storage unit 45 as information specifying ranges and combinations of the vehicle speed, the acceleration, the inclination angle (roll angle), the pitch angle, the yaw angle, and / or the angular speed as information for specifying each state.The state in which the saddle riding vehicle 10 is likely to crash includes a state in which the inclination angle from the state in which the saddle riding vehicle 10 is inclined leftward and rightward and is turning is equal to or greater than a predetermined inclination threshold, and may be indicated by the inclination angle of the saddle riding vehicle 10 or the like.That is, the separation control unit 44D acquires vehicle information such as the vehicle speed, the acceleration, the inclination angle, and the like of the saddle riding vehicle 10 via the vehicle sensor 10S, and determines whether the early separation condition is satisfied based on the acquired vehicle information.When the early separation condition is satisfied (step S 3: YES), the airbag control unit 44 performs an early separation process (step S 31). At the time of the early separation, the airbag control unit 44 causes the separation control unit 44D to separate the airbag 42 early.More specifically, in a case where the inclination angle and / or the angular velocity of the saddle riding vehicle 10 satisfies a predetermined condition for prediction of a fall, the detachment control unit 44D causes the detachment unit 43 to detach the airbag 42 without waiting until the airbag 42 is fully deployed (during the deployment of the airbag 42). Therefore, in a state where the saddle riding vehicle 10 is liable to crash, the airbag 42 is quickly separated in a state where it has deployed to a predetermined state, and the airbag 42 does not interfere with the transition of the driver R to sliding on the road surface. Moreover, in a case where the airbag 42 has deployed as far as is required for the protection of the driver R, a protection effect for the driver by the airbag 42 is also expected.More specifically, in a case where the saddle riding vehicle 10 is in a high-speed running state, in a case where the speed at the time of the collision or immediately before the collision is equal to or greater than a preset speed threshold, the airbag control unit 44 causes the detachment unit 43 to detach the airbag 42 without waiting until the airbag 42 is fully deployed (during the deployment of the airbag 42).In the collision in the high-speed running state, there is a high possibility that the rider R is separated from the saddle riding vehicle 10 before the airbag 42 is fully deployed. By performing the early separation, the airbag 42 can be caused to follow the rider R separated from the saddle riding vehicle 10 in a short time, so that an effect of mitigating the impact applied to the rider R after the separation is expected.When the early separation condition is not satisfied (step S 3: NO), the airbag control unit 44 causes the separation control unit 44D to determine whether a predetermined separation condition is satisfied (step S 4). The predetermined separation condition is a condition indicating a state in which it is desirable to separate the airbag 42 earlier than a case in which the airbag 42 is separated by a maximum deceleration separation process to be described later.The predetermined separation condition corresponds to the "predetermined state" of the present invention.In the present embodiment, the airbag 42 is fixed to the saddle riding vehicle 10 behind the rider R. Accordingly, in a case where the driver R moves forward with respect to the saddle riding vehicle 10, the forward movement speed of the driver R can be effectively reduced by delaying the cut-off timing of the airbag 42.In the present embodiment, in a case where the driver R does not move forward with respect to the saddle riding vehicle 10, such as a rear impact and a side impact, it is difficult to effectively reduce the separation speed of the driver R even if the separation timing of the airbag 42 is delayed.The detachment control unit 44D acquires vehicle information of the saddle riding vehicle 10 via the acquisition unit 44C, and in a case where it is determined that a predetermined deceleration condition is satisfied based on the acquired vehicle information (step S 4: YES), the detachment control unit 44D performs a detachment process for detaching the airbag 42 at a predetermined timing (step S 41).Meanwhile, in a case where it is determined that the predetermined deceleration condition is not satisfied (step S 4: NO), the separation control unit 44D performs a maximum deceleration separation process (step S 5). The maximum deceleration separation process is a process for separating the airbag 42 by the separating unit 43 after the airbag 42 is fully deployed. In the separation process in step S 41, the airbag 42 may also be separated by the separation unit 43 after the airbag 42 is fully deployed according to the deceleration condition.FIG. 6 is a flowchart showing an example of the flow after step S 2 of the flowchart of FIG. 5.As shown in FIG. 6, in a case where the inflator 41 is operated according to step S 2, the airbag control unit 44 determines whether the airbag deployment time TA has exceeded a preset time threshold DT (step S 1A).The time threshold DT controls a time equal to or longer than a lower limit value SB (referred to as a "necessary and sufficient deployment state SB") of a necessary and sufficient deployment state in which the airbag 42 can sufficiently protect the driver R, and controls a deployment time until the airbag 42 is deployed to 70%, for example. Preferably, the necessary and sufficient deployment state SB is a state in which the impact force acting between the airbag 42 and the driver R can be alleviated, and in a case where the driver R separated from the saddle riding vehicle 10 is brought into contact with the road surface, the impact force acting between the driver R and the road surface can be mitigated, and a state in which the airbag 42 is deployed into a state in which it includes the driver R.However, the necessary and sufficient deployment state SB may be a state set by a manufacturer of the saddle riding vehicle 10 or the like, and is controlled by a deployment time TT (FIG. 7 ) from the start of deployment.In a case where the airbag deployment time TA has exceeded the time threshold DT (step S 1A; YES), the airbag control unit 44 causes the collision determination unit 44A to determine whether a falling state or a falling is predicted (step S 2A). When a falling state or a fall is predicted (step S 2A: YES), the airbag control unit 44 performs a separation process for falling mitigation (step S 1B).The separation process that captures a fall is a process for separating the airbag 42 at an appropriate time when a fall occurs. For example, the airbag 42 is disconnected after waiting until the necessary and sufficient deployment state SB is reached, so that the airbag 42 is disconnected after waiting until the airbag 42 inflates to the extent required for surrounding the driver. Accordingly, the driver R can be quickly separated together with the airbag 42 when the fall occurs.The separation process that captures the fall may be performed later than at a time corresponding to the necessary and sufficient deployment state SB. The time of separation may be appropriately set by a manufacturer of the saddle riding vehicle 10 or the like. Moreover, in a fall-absorbing separation process using the angular velocity or the inclination angle, a threshold value may be provided for determining whether there is a margin before the impact, and in the case that there is a margin before the impact, a process for separating the airbag 42 may be performed after waiting until the airbag 42 fully deploys.In a case where the determination result in step S 2 is NO (step S 2; NO), the airbag control unit 44 determines whether the saddle riding vehicle 10 has been in a high-speed traveling state, and specifically determines whether the saddle riding vehicle 10 has been in a high-speed traveling state immediately before the prediction of a collision or a fall (step S 3A).In a case where the saddle riding vehicle 10 has been in a high-speed running state (step S 3A; YES), the airbag control unit 44 performs a separation process that prioritizes the tracking of the driver (step S 1C).The separation process that prioritizes the tracking of the driver is a process for separating the airbag 42 without waiting until the airbag 42 is fully deployed when the airbag 42 has inflated to the extent necessary for surrounding the driver, because the separation of the driver R is predicted until the airbag 42 is fully deployed. The state in which the airbag 42 inflates by the amount required for the rider to be surrounded is controlled by a timing set by the manufacturer of the saddle riding vehicle 10 or the like, that is, a deployment time from the start of the deployment.Therefore, the airbag control unit 44 disconnects the airbag 42 at a time when the airbag deployment time TA detected by the detection unit 44C reaches the deployment time. In the present embodiment, even before the elapse of the necessary and sufficient deployment state SB in FIG. 7 described later, the airbag 42 is separated in a case where the airbag 42 is deployed to a predetermined state. The airbag 42 can be separated at a time when it has a necessary and sufficient deployment state SB.In a case where the saddle riding vehicle 10 is not in a high-speed running state (step S 3A; YES), the airbag control unit 44 determines whether the driver moving distance LA detected by the detection unit 44C reaches a preset distance threshold DL (step S 4A).The distance threshold DL is set to a value within a range of the driver moving distance LA that can reduce the moving speed of the driver R. Therefore, the moving speed of the driver R is reduced using the voltage FT of the airbag 42 shown in FIG. 3 until the driver moving distance LA reaches the distance threshold DL.When the driver's moving distance LA does not reach the distance threshold DL (step S 4A; NO), the airbag control unit 44 determines whether the airbag release time TA has exceeded a preset maximum delay time DM (step S 5A).When the airbag release time TA has not exceeded the maximum delay time DM (step S 5A; NO), the airbag control unit 44 proceeds to the process of step S 4A.In a case where the moving distance LA of the driver reaches the distance threshold DL (step S 4A; YES) or the airbag deployment time TA has exceeded the maximum delay time DM (step S 5A; YES), the airbag control unit 44 performs a process of separating the airbag 42 (step S 6A).The maximum delay time DM is set at a time point at which the separation of the airbag 42 is ensured after the time point of the complete deployment of the airbag 42. Therefore, even in a case where the moving distance LA of the driver does not reach the distance threshold DL, the airbag 42 is reliably disconnected for a limited period of time, so that the driver R can be easily disconnected from the saddle riding vehicle 10 together with the airbag 42. The maximum delay time DM may be set to an appropriate time by a manufacturer of the saddle riding vehicle 10 or the like.FIG. 7 is a sequence diagram showing the deployment timing of the airbag 42 at least in a frontal impact. In FIG. 7, the "X integral value" indicates a forward moving distance LA of the driver R, the "Y integral value" indicates a lateral moving distance LA of the driver R, the "integral value of the XY synthesis G" indicates a synthesis value of the X integral value and the Y integral value, and the horizontal axis indicates time.For convenience of description, a variation characteristic of the "X integral value" is indicated by a reference numeral fx, illustrating a case where the driver R moves forward. The variation characteristic of the "Y integral value" is indicated by reference numerals fy 1, fy 2 and fy 3, illustrating a case where the amount of lateral movement of the driver R increases in the order of the variation characteristics fy 1, fy 2 and fy 3. A change characteristic of the "integral value of the XY synthesis G" indicates a change characteristic fxy of the synthesis of the change characteristics fx and fy.The distance threshold DL is set for each of the X integral value and the Y integral value, and in FIG. 7, the distance threshold DL of the X integral value is indicated by "distance threshold DL(X)", and the distance threshold DL of the Y integral value is indicated by "distance threshold DL(Y)".The distance threshold DL(X) corresponds to a "first distance threshold" of the present invention, and the distance threshold DL(Y) corresponds to a "second distance threshold" of the present invention.In FIG. 7, the time T1 is the time of collision, the time T2 is the time of inflation device deployment (start of deployment), and the time T3 is the time of reaching a necessary and sufficient deployment state SB. The deployment time TTfrom the inflation device T 2 being deployed to the required and sufficient deployment state SBis a constant value.A collision occurs, and in cases where the change characteristic fx of the X integral value and the change characteristic fy 1 of the Y integral value at a time Ta reaches the distance threshold DL(X), the change characteristic fy 1 at the time Ta is smaller than the distance threshold DL(Y). Since the timing Ta exceeds the timing T3 of the necessary and sufficient deployment state SB (the airbag deployment time TA exceeds the timing of the time threshold DT), the airbag 42 is disconnected at the timing Ta.Since the airbag 42 is disconnected only when the X integral value (longitudinal driver moving distance LA) reaches the distance threshold value DL(X), it is possible to protect the driver R by the airbag 42 being deployed more than necessary and sufficiently (deployed state SB) while effectively reducing the moving speed of the driver R by the airbag 42.In the case of the change characteristic fx of the X integral value and the change characteristic fy 2 of the Y integral value, the change characteristic fy 2 reaches the distance threshold value DL(Y) at a time Tb. This time Tb is earlier than the time Ta at which the change characteristic fx reaches the distance threshold DL(X), and goes beyond the time T 3 of the necessary and sufficient release state SB. Therefore, the airbag 42 is separated at time Tb.The airbag 42 is disconnected only when the Y integral value (driver lateral movement distance LA) has reached the distance threshold value DL(Y). Therefore, it is possible to protect the driver R by the airbag 42 deployed more than necessary and sufficiently (deployed state SB) while effectively reducing the speed of lateral movement of the driver R by the airbag 42.Further, for example, in a case where the degree of the side collision is strong, the change characteristic fy 3 of the Y integral value is displayed. In this case, the change characteristic fy 3 reaches the distance threshold DL(Y) at a time Tc. This time Tc is before the time T3 of the necessary and sufficient triggering state SB. Therefore, the airbag 42 is not disconnected at time Tc. The airbag 42 is disconnected at a time after the time T3 of the necessary and sufficient deployment state SB has elapsed.Even in a case where the Y integral value (driver lateral movement distance LA) reaches the distance threshold DL(Y), the airbag 42 is not disconnected until the necessary and sufficient deployment state SB is reached. Therefore, it is possible to protect the driver R by the airbag 42 deployed more than necessary and sufficiently (deployed state SB) while effectively reducing the speed of lateral movement of the driver R by the airbag 42.FIG. 8 is a sequence diagram showing the time of separation of the airbag 42 in a rear or side impact. In FIG. 8, a distance threshold DL (corresponding to a first distance threshold) of the X integral value is indicated by "distance threshold DL(+X)" in a deceleration direction and "distance threshold DL(-X)" in an acceleration direction.The "distance threshold DL(+X)" in a deceleration direction corresponds to a threshold in a vehicle front-rear direction direction in which the driver R is located with respect to the vehicle support position of the airbag 42. The "distance threshold DL(-X)" in the acceleration direction corresponds to a threshold in the other direction opposite to the one direction. Since the one direction is a direction in which the airbag 42 can most suppress the movement of the driver R, the "distance threshold DL(+X)" is set to a value larger than the "distance threshold DL(-X)" and a distance threshold DL (corresponding to a second distance threshold) of the Y integral value.The distance threshold DL of the Y integral value includes a "distance threshold DL(+Y)" in the right direction and a "distance threshold DL(-Y)" in the left direction.In the case of a rear collision including, as shown in FIG. 8, a change characteristic fx 2 of the X integral value and a change characteristic fy 4 of the Y integral value, the change characteristic fx 2 reaches the distance threshold value DL(-X) at a time Te. Since the time Te is earlier than the time T 3 of the necessary and sufficient deployment state SB, the airbag 42 is not disconnected at the time Te. The airbag 42 is cut at a timing after the timing T 3 of the necessary and sufficient deployment state SB.In a rear impact, the driver R may be separated by rapidly separating the airbag 42 from the vehicle started from behind. Therefore, the distance threshold DL(-X) is set to a small value so that the airbag 42 can be quickly separated, thereby separating the airbag 42 at the time of the necessary and sufficient deployment state SB in a rear collision.In a case where a collision occurs only on the side and the change characteristic fy 4 of the Y integral value is displayed, the change characteristic fy 4 reaches the distance threshold value DL(-Y) at a time Tf. Since the time Tf is after the time T 3 of the necessary and sufficient deployment state SB, the airbag 42 is disconnected at the time Tf.The airbag 42 is disconnected only when the Y integral value (lateral driver movement distance LA) reaches the distance threshold value DL(Y). Therefore, it is possible to protect the driver R by the airbag 42 deployed more than necessary and sufficiently (deployed state SB) while effectively reducing the speed of lateral movement of the driver R by the airbag 42.As described above, the airbag device 40 includes the separation unit 43 that separates the airbag 42 deploying around the driver R from the saddle-riding vehicle 10, the detection unit 44C that detects an elapsed time (airbag deployment time TA or the like) from the time of deploying the airbag 42, and the separation control unit 44D that causes the separation unit 43 to separate the airbag 42 in a case where a separation condition (predetermined condition) including a first condition, namely, the elapsed time detected by the detection unit 44C exceeds the time threshold DT is satisfied.According to this configuration, by delaying the release timing of the airbag 42 in consideration of the time elapsed from the deployment of the airbag 42, the separation speed of the driver R using the airbag 42 is decreased, thereby making it easier to decrease the separation speed of the driver R.Moreover, the time threshold DT is larger than the time until the airbag 42 is deployed to a predetermined state (necessary and sufficient deployment state SB). According to this configuration, the time of separation of the airbag 42 is delayed, whereby the protection effect of the airbag 42 when the rider R is separated from the saddle riding vehicle 10 can be very easily achieved.Moreover, the detection unit 44C performs an arithmetic process to estimate the driver moving distance LA corresponding to the moving distance of the driver R with respect to the saddle riding vehicle 10 based on the acceleration of the saddle riding vehicle 10. The detachment condition further includes a second condition that the driver moving distance LA exceeds the preset distance threshold DL, and the detachment control unit 44D causes the detachment unit 43 to detach the airbag 42 in a case where at least the first condition and the second condition are satisfied. According to this configuration, the separation timing of the airbag 42 can be delayed in consideration of the driver moving distance LA, and the separation speed of the driver R can be reduced by using the airbag 42, thereby making it easier to reduce the separation speed of the driver R.In addition, since the existing acceleration sensor of the saddle riding vehicle can be used, the cost and the number of components can be reduced as compared with using another sensor to detect the driver moving distance LA.Moreover, the acquisition unit 44C acquires an acceleration in the vehicle front-rear direction and an acceleration in the vehicle front-rear direction, estimates a moving distance (X integral values in FIGS. 7 and 8 ) of the driver R in the vehicle front-rear direction with respect to the saddle-riding vehicle 10 based on the acceleration in the vehicle front-rear direction, and estimates a moving distance (Y integral values in FIGS. 7 and 8 ) of the driver R in the vehicle front-rear direction with respect to the saddle-riding vehicle 10 based on the acceleration in the vehicle front-rear direction. The distance threshold DL includes the first distance threshold (the distance threshold DL(X) in FIG. 7 and the distance threshold DL(+X) and the distance threshold DL(-X) in FIG. 8 ) which is a distance threshold in the longitudinal direction of the vehicle, and the second distance threshold (the distance threshold DL(Y) in FIG. 7 and the distance threshold DL(+Y) and the distance threshold DL(-Y) in FIG. 8 ) which is a distance threshold in the lateral direction of the vehicle.The detection unit 44C determines that the second condition is satisfied when either one of the case where the moving distance of the driver R in the longitudinal direction of the vehicle exceeds the first distance threshold value or the case where the moving distance of the driver R in the lateral direction of the vehicle exceeds the second distance threshold value is satisfied.According to this configuration, the moving speed of the driver R by the airbag 42 can be reduced until the driver R reaches one of the longitudinal and transverse distance threshold values DL. Therefore, the moving speed of the rider R in the longitudinal direction and the lateral direction is suppressed, whereby separation from the saddle riding vehicle 10 can be easily performed.As shown in FIG. 8, the first distance threshold includes the distance threshold DL(+X) corresponding to a threshold in one direction (forward direction) in the longitudinal direction of the vehicle in which the driver R is positioned with respect to the vehicle support position in which the airbag 42 is supported by the saddle riding vehicle 10, and the distance threshold DL(-X) corresponding to a threshold in the other direction (rearward direction). A part (opposing deployment portion 50) of the airbag 42 is deployed for the driver R at least in one direction, and in one direction, a threshold value (distance threshold value DL(+X)) is set to a value larger than a threshold value (distance threshold value DL(-X)) in the other direction and the second distance threshold value (distance threshold value DL(+Y) and distance threshold value DL(-Y)).According to this configuration, the airbag 42 is deployed around the driver R in a direction, so that the airbag 42 smoothly reduces the moving speed of the driver R in one direction. With respect to the movement of the driver R in one direction, the airbag 42 effectively reduces the movement speed of the driver R, and with respect to the movement of the driver R in other directions, the airbag 42 is quickly separated, so that the driver R is easily and early separated from the saddle riding vehicle 10 together with the airbag 42.Moreover, in a case where the inclination angle and / or the angular velocity of the saddle-riding vehicle 10 for prediction of a camber satisfy a predetermined condition, the airbag control unit 44 separates the airbag 42 when the airbag 42 is deployed to a predetermined state even before the driver moving distance LA exceeds the distance threshold DL (which corresponds to a case where the second condition is not satisfied).According to this configuration, in a case where a fall is predicted, the driver R is smoothly and quickly separated. For example, in the event of a camber in a curve, the force acting on the driver R is relatively low, which is why the separation of the driver R can take place with priority.Moreover, in a case where a collision is detected, the airbag 42 is deployed, and in a preset high-speed running state, when a collision is detected, the detachment control unit 44D detaches the airbag 42 in a case where the airbag 42 is deployed to a predetermined state even before the driver moving distance LA exceeds the distance threshold DL (equivalent to a case where the second condition is not satisfied). According to this configuration, in a high-speed traveling state, the rider R is quickly separated from the saddle riding vehicle 10 while being protected by the airbag 42, whereby collision of the rider with other vehicles and the like can be avoided.Note that the above embodiment is merely an aspect of the present invention, and the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the case where the vehicle support position of the airbag 42 is behind the driver R has been described, but the present invention is not limited thereto. For example, the vehicle support position may be located in front of the driver R.FIG. 9 is a side view showing an airbag device 40 according to a modification example together with a saddle riding vehicle 10. FIG. 10 is a left side view showing a state in which the airbag 42 shown in FIG. 9 deploys to protect a driver R. Similar configurations are denoted by the same reference numerals, and redundant description is omitted.The airbag device 40 according to the modification example includes an airbag 42 that is supported by the saddle riding vehicle 10 in front of the rider R and deploys in regions including the rear of the rider R.Specifically, as shown in FIG. 9, an airbag housing unit 33 is disposed at a rear end portion of a fuel tank 29, and the airbag 42 is accommodated in the airbag housing unit 33 in a folded state. Similarly to a front wheel 13, the airbag 42 is disposed at the center in the vehicle width direction.As shown in FIG. 10, the airbag 42 includes a vehicle-body-support-side deploying portion 49 positioned at the time of deployment on the front side of the driver R, which is the vehicle-body-support-position side (may also be referred to as the inflator 41 side or the airbag housing unit 33 side), and an opposing deploying portion 50 positioned at the time of deployment on the rear side of the driver R, which is the vehicle-body-support-position opposing side.The vehicle body support side deploying portion 49 functions as a front cover portion that covers the body R 1 of the driver R from the front and has a shape that extends upward from the airbag housing unit 33. Moreover, the opposing deployment portion 5 ofunctions as a rear cover portion that covers the body R 1 from behind and has a shape that extends upward to near a head R 2 of the driver R.The opposing deploying portion 50 includes a front extending portion 51 that extends rearward from both side portions of the vehicle body support side deploying portion 49 on the vehicle width direction outer side, and an inward bent portion 52 that is bent inward from the front extending portion 51 in the vehicle width direction and extends inward in the vehicle width direction. Further, the opposing deploying portion 50 includes a downward extending portion 53 bent downward from the inward bent portion 52 and extending downward, and a folding portion 54 folded back from the downward extending portion 53 toward the front extending portion 51. The front extension portion 51 covers the body R 1 from the outside under an arm R 3 of the driver R and protects the body R 1 from the outside. Therefore, the opposing deployment portion 50 covers the body R 1 of the driver R from behind, as well as from left and right.Since the deploying airbag 42 circumferentially covers the driver R, the driver R can be protected from front, left, right, and rear. The airbag 42 is fixed to the saddle riding vehicle 10 in front of the rider R. Accordingly, in a case where a rear impact occurs, that is, in a case where an inertial force F that moves the driver R toward the rear of the saddle riding vehicle 10 is generated as shown in the example in FIG. 10, the rearward movement speed of the driver R with a tension FT of the airbag 42 can be reduced by delaying the separation of the airbag 42.Moreover, even in a case where an inertial force F moving the rider R to the saddle riding vehicle 10 side is generated, the lateral moving speed of the rider R can be reduced to some extent with a tension FT of the airbag 42. Since the airbag 42 covers the rider R also from the front, even in the case where an inertial force F moving the rider R to the front of the saddle riding vehicle 10 is generated, the forward movement speed of the rider R can be reduced with a tension FT of the airbag 42 to some extent.By also providing, in this airbag device 40, an airbag control unit 44 that detects an elapsed time (airbag deployment time TA or the like) from the deployment of the airbag 42 and causes the detachment unit 43 to detach the airbag 42 in a case where a detachment condition (predetermined condition) including the elapse of a predetermined time (corresponding to a time threshold DT) is satisfied, it is possible to achieve various effects of the above-described embodiment, such as reducing the detachment speed of the driver R using the airbag 42 and facilitating the reduction of the detachment speed of the driver R.Moreover, in the above-described embodiment, the case where the driver moving distance LA, i.e., the moving distance of the driver R with respect to the saddle riding vehicle 10, is estimated based on the acceleration of the saddle riding vehicle 10, and the release timing of the airbag 42 is delayed in consideration of the moving distance LA of the driver has been illustrated, but the present invention is not limited to this configuration.For example, as shown in FIG. 11, the airbag control unit 44 is provided with a load detection unit 144C that detects a tension FT with which the airbag 42 is pulled by the movement of the driver R. The disconnection condition further includes a third condition that the voltage FT exceeds a preset voltage threshold, and the disconnection control unit 44D causes the disconnection unit 43 to disconnect the airbag 42 in a case where at least the first condition and the third condition are satisfied. Therefore, the cut-off timing of the airbag 42 can be delayed until the voltage FT exceeds the voltage threshold, and the cut-off speed of the driver R can be effectively reduced.The tension threshold value may be set to an appropriate value by a manufacturer of the saddle riding vehicle 10 or the like, and is set to, for example, an upper limit or a value near the upper limit of the tension at which the airbag 42 does not tear.In this case, the saddle-riding vehicle 10 may be provided with a load sensor that detects the voltage FT as one of the vehicle sensors 10S, and the load detection unit 144C may detect a detection result of the load sensor. For example, the load detection unit 144C has a configuration in which the function related to the driver moving distance LA is removed from the detection unit 44C, and a function related to the voltage FT is added instead. However, the present invention is not limited to this configuration, and thus the load sensing unit 144C may have a configuration in which a function related to the voltage FT is added to the sensing unit 44C to delay the cut-off timing of the airbag 42 in consideration of both the voltage FT and the driver moving distance LA.In the above-described embodiment, the case where, in addition to the driver moving distance LA (corresponding to the X integral value) in the longitudinal direction, the driver moving distance LA (corresponding to the Y integral value) in the lateral direction is calculated has been described. However, a configuration in which the driver moving distance LA in the lateral direction is not calculated may also be used.For example, in a case where the acceleration in the lateral direction or the acceleration in the other direction (forward direction in FIG. 3, rearward direction in FIG. 4 ) exceeds a predetermined threshold value before the moving distance (corresponding to the X integral value) of the driver R in one direction (forward direction in FIG. 3, rearward direction in FIG. 4 ) with respect to the saddle riding vehicle 10 exceeds the first distance threshold value (the distance threshold value DL(X) in FIG. 7 ) and the acceleration in the lateral direction or the acceleration in the other direction (forward direction in FIG. 3, rearward direction in FIG. 4 ) exceeds a predetermined threshold value, the airbag control unit 44 may disconnect the airbag 42, before the moving distance (corresponding to the X integral value) in one direction exceeds the first distance threshold. Instead of the moving distance calculated by second-order integration, a speed calculated by first-order integration may be used instead of the acceleration.That is, the separation condition includes a fourth condition that, before the moving distance (corresponding to the X integral value) in one direction in the longitudinal direction of the vehicle in which the driver R is positioned with respect to the vehicle support position in which the airbag 42 is supported by the saddle-riding vehicle 10 exceeds the first distance threshold, the following condition is satisfied: the acceleration in the lateral direction of the vehicle and / or the acceleration in the other direction opposite to the one direction and / or the speed in the lateral direction of the vehicle and / or the speed in the other direction opposite to the one direction exceeds a predetermined threshold. The detachment control unit 44D may cause the detachment unit 43 to detach the airbag 42 when the first condition and the fourth condition are satisfied.According to this configuration, the airbag 42 can be easily and quickly separated in a side collision. In addition, since the airbag 42 can be separated at the time of a side collision without calculation of a moving distance in the lateral direction and the like, it is possible to reduce the processing capacity required for the airbag control unit 44, which is advantageous in terms of cost.Although the case where the present invention is applied to the airbag device 40 for the driver R has been described, the present invention may be applied to an airbag device for a driver including a passenger.Although the case where the present invention is applied to the airbag device 40 of the motorcycle shown in FIG. 1 and the like has been described, the present invention is not limited thereto, and thus the present invention can be applied to an airbag device of a vehicle such as other bicycles and saddle-type vehicles including three-wheel types and four-wheel types.[Configuration Supported by Above Embodiments]The above embodiments support the following configurations.(Configuration 1) An airbag device mounted on a vehicle and provided with an airbag deployed circumferentially around a driver, the airbag device including: a detachment unit that separates the airbag from the vehicle; a detection unit that detects an elapsed time from the deployment of the airbag; and a detachment control unit that causes the detachment unit to detach the airbag in a case where a predetermined condition including a first condition, namely, the elapsed time detected by the detection unit exceeds a time threshold, is satisfied.According to this configuration, by delaying the separation timing of the airbag in consideration of the elapsed time from the deployment of the airbag, the separation speed of the driver using the airbag is reduced, thereby making it easier to reduce the separation speed of the driver.(Configuration 2) The airbag device according to Configuration 1, in which the time threshold is greater than the time until the airbag ( 42) is deployed to a predetermined state.According to this configuration, a protective effect of separating the driver from the vehicle by the airbag is easily achieved.(Configuration 3) The airbag device according to Configuration 1 or 2, wherein the acquisition unit performs an arithmetic process to estimate a moving distance of the driver with respect to the vehicle based on acceleration of the vehicle, the predetermined condition further includes a second condition that the moving distance exceeds a preset distance threshold, and the detachment control unit causes the detachment unit to detach the airbag in a case where at least the first condition and the second condition are satisfied.According to this configuration, the airbag detachment timing can be delayed in consideration of the driver's moving distance with respect to the vehicle. Since the acceleration sensor of the vehicle can be used, it is easier to reduce the cost and the number of components, as compared with using another sensor for detecting the moving distance.(Configuration 4) The airbag device according to Configuration 3, wherein the detection unit detects an acceleration in the longitudinal direction of the vehicle and an acceleration in the lateral direction of the vehicle, estimates a moving distance of the driver in the longitudinal direction of the vehicle with respect to the vehicle based on the acceleration in the longitudinal direction of the vehicle, and estimates a moving distance of the driver in the lateral direction of the vehicle with respect to the vehicle based on the acceleration in the lateral direction of the vehicle, the distance threshold includes a first distance threshold that is a distance threshold in the longitudinal direction of the vehicle and a second distance threshold that is a distance threshold in the lateral direction of the vehicle, and it is determined that the second condition is determined in a case where either the moving distance of the driver in the longitudinal direction of the vehicle exceeds the first distance threshold, or the moving distance of the driver in the lateral direction of the vehicle exceeds the second distance threshold.According to this configuration, the moving speed of the driver through the airbag can be reduced until the driver reaches one of the distance thresholds set for the longitudinal direction and the lateral direction. Therefore, the moving speed of the driver in the longitudinal and transverse directions is suppressed, whereby separation from the vehicle can be easily performed.(Configuration 5) The airbag device according to Configuration 4, wherein the first distance threshold includes a threshold in one direction and a threshold in another direction in the longitudinal direction of the vehicle in which the driver is positioned with respect to a vehicle support position in which the airbag is supported by the vehicle, a part of the airbag is deployed to the driver at least in the one direction, and the threshold in one direction is larger than the threshold in the other direction and the second distance threshold.According to this configuration, since the airbag deploys in one direction, it can easily reduce the moving speed of the driver in one direction. With respect to the movement of the driver in one direction, the airbag effectively reduces the speed of movement of the driver, and with respect to the movement of the driver in other directions, the airbag can be quickly disconnected, so that the driver can be easily disconnected from the vehicle together with the airbag.(Configuration 6) The airbag device according to Configuration 1 or 2, in which a load detection unit that detects a tension with which the airbag is pulled by the driver's movement is provided, the predetermined condition further including a third condition that the tension exceeds a preset tension threshold, and the detachment control unit causes the detachment unit to detach the airbag in a case where the first condition and the third condition are satisfied.According to this configuration, the airbag cut-off timing can be delayed in consideration of the tension with which the airbag is pulled by the driver's movement, thereby making it easier to efficiently reduce the driver's movement speed by the airbag.(Configuration 7) The airbag device according to Configuration 3, in which the predetermined condition includes a fourth condition that, before a moving distance of the driver with respect to the vehicle in a direction in a longitudinal direction of the vehicle in which the driver is positioned with respect to a vehicle support position in which the airbag is supported by the vehicle exceeds the distance threshold, the following condition is satisfied: an acceleration in a lateral direction of the vehicle and / or an acceleration in another direction opposite to the one direction and / or a speed in the lateral direction of the vehicle and / or a speed in the other direction opposite to the one direction exceeds a predetermined threshold, wherein the detachment control unit causes the detachment unit to detach the airbag in a case where the first condition and the fourth condition are satisfied.According to this configuration, the airbag can be easily and quickly separated in a side collision. In addition, since the airbag can be separated at a side impact without the calculation of a moving distance in the lateral direction and the like, it is possible to reduce the processing capacity required for the airbag control unit, which is advantageous in terms of cost.(Configuration 8) The airbag device according to any one of Configurations 3 to 5, wherein, in a case where the inclination angle and / or angular velocity of the vehicle satisfy a predetermined condition, the detection unit shuts off the airbag when the airbag is deployed in a predetermined state even in a case where the second condition is not satisfied.According to this configuration, in a case where a fall is predicted, the driver is easily and quickly separated.(Configuration 9) The airbag device according to any one of Configurations 3 to 5 and 8, in which the airbag is deployed in a case where a collision of the vehicle is detected, and when the collision is detected in a preset high-speed running state, even in a case where the second condition is not satisfied, the detachment control unit detaches the airbag without deceleration when the airbag is deployed in a predetermined state.According to this configuration, in a high-speed running state, the driver is quickly separated from the vehicle while being protected by the airbag, whereby collision of the driver with other vehicles and the like can be avoided.List of reference characters10 Saddle riding vehicle 40 Airbag device 41 Inflator 42 Airbag 43 Detachment unit 44 Airbag control unit 44A Collision determination unit 44B Deployment control unit 44C Detection unit 44D Detachment control unit 45 Storage unit 144C Load detection unit LA Driver movement distance R Driver SB Necessary and Sufficient Deployment StateReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 10-006901 A

[0003]

Claims

An airbag device mounted on a vehicle (10) and provided with an airbag (42) that deploys circumferentially around a driver, the airbag device comprising: a detachment unit (43) that separates the airbag (42) from the vehicle (10); a detection unit (44C) that detects an elapsed time from deployment of the airbag (42); and a detachment control unit (44D) that causes the detachment unit (43) to detach the airbag (42) in a case where a predetermined condition including a first condition, namely, the elapsed time detected by the detection unit (44C) exceeds a time threshold, is satisfied.The airbag device of claim 1, wherein the time threshold is higher than the time until the airbag (42) is deployed to a predetermined state.The airbag device according to claim 1 or 2, wherein the detection unit (44C) performs an arithmetic process to estimate a moving distance of the driver with respect to the vehicle (10) based on acceleration of the vehicle (10), the predetermined condition further includes a second condition that the moving distance exceeds a preset distance threshold, and the detachment control unit (44D) causes the detachment unit (43) to detach the airbag (42) in a case where at least the first condition and the second condition are satisfied.The airbag device according to claim 3, wherein the detection unit (44C) detects acceleration in a longitudinal direction of the vehicle and acceleration in a lateral direction of the vehicle, estimates a moving distance of the driver in the longitudinal direction of the vehicle with respect to the vehicle (10) based on the acceleration in the longitudinal direction of the vehicle, and estimates a moving distance of the driver in the lateral direction of the vehicle with respect to the vehicle (10) based on the acceleration in the lateral direction of the vehicle, the distance threshold includes a first distance threshold that is a distance threshold in the longitudinal direction of the vehicle and a second distance threshold that is a distance threshold in the lateral direction of the vehicle, and it is determined that the second condition is satisfied in a case where one of the cases, in which the moving distance of the driver in the longitudinal direction of the vehicle exceeds the first distance threshold value, and in which the moving distance of the driver in the lateral direction of the vehicle exceeds the second distance threshold value is satisfied.The airbag device according to claim 4, wherein the first distance threshold includes a threshold in one direction and a threshold in another direction in the longitudinal direction of the vehicle in which the driver is located with respect to a vehicle support position in which the airbag (42) is supported by the vehicle, a part of the airbag (42) is deployed for the driver at least in the one direction, and the threshold in one direction is higher than the threshold in the other direction and the second distance threshold.The airbag device according to claim 1 or 2, wherein a load detection unit (144C) that detects a tension with which the airbag (42) is pulled by the driver's movement is provided, the predetermined condition further includes a third condition that the tension exceeds a preset tension threshold, and the disconnection control unit (44D) causes the disconnection unit (43) to disconnect the airbag (42) in a case where the first condition and the third condition are satisfied.The airbag device according to claim 3, wherein the predetermined condition includes a fourth condition that before a moving distance of the driver with respect to the vehicle (10) in a direction in a longitudinal direction of the vehicle in which the driver is positioned with respect to a vehicle support position in which the airbag (42) is supported by the vehicle exceeds the distance threshold, the following condition is satisfied: an acceleration in a lateral direction of the vehicle and / or an acceleration in another direction opposite to the one direction and / or a speed in the lateral direction of the vehicle and / or a speed in the other direction opposite to the one direction exceeds a predetermined threshold, and the detachment control unit (44D) causes the detachment unit (43) to detach the airbag (42) in a case, in which the first condition and the fourth condition are satisfied.The airbag device according to any one of claims 3 to 5, wherein in a case where an inclination angle and / or an angular velocity of the vehicle (10) satisfy a predetermined condition, the detection unit (44C) shuts off the airbag (42) when the airbag (42) is deployed to a predetermined state even in a case where the second condition is not satisfied.The airbag device according to any one of claims 3 to 5 and 8, wherein the airbag (42) is deployed in a case where a collision of the vehicle (10) is detected, and in a preset high-speed running state, when the collision is detected, even in a case where the second condition is not satisfied, the detachment control unit (44D) detaches the airbag (42) without deceleration when the airbag (42) is deployed to a predetermined state.

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