Air bag device

Abstract

To provide an air bag device advantageous in restraining both the head and the chest that tilt forward during a frontal collision substantially simultaneously and in a well-balanced manner by an air bag.SOLUTION: When an occupant position detected by a seat slide sensor 26 is a position closer to the front of a vehicle and the occupant forward inclination angle φ during a frontal collision is small, a restraint surface angle control portion 50 controls a deployment shape adjustment unit 30 in such a manner that a restraint surface angle θ of an inflating and expanding air bag 14 becomes small. On the other hand, when the occupant position is the position closer to the rear of the vehicle and the occupant forward inclination angle φ during a frontal collision is large, the restraint surface angle control portion 50 controls the deployment shape adjustment unit 30 in such a manner that the restraint surface angle θ of the inflating and expanding air bag 14 becomes large. Thus, both a head 18 and a chest 20 of an occupant 16 tilting forward during a frontal collision are restrained substantially simultaneously and in a well-balanced manner by a restraint surface 1402 of the air bag 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an airbag device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, airbag devices have been known which include an airbag that is mounted on an instrument panel and inflates and deploys toward the front seat in the event of a vehicle collision. Patent Document 1 discloses a technology that limits the amount of airbag inflation based on the front seat's longitudinal position in the vehicle, i.e., based on the occupant's position, allowing the airbag to deploy smoothly even when the occupant moves forward due to braking immediately before a collision, bringing them closer to the instrument panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-88007 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when attention is paid to the behavior of the upper body (head and chest) of a front seat occupant during a frontal collision, the occupant's upper body leans forward with the waist as the center of rotation. The degree to which the occupant's upper body leans forward when restrained by the airbag increases as the occupant's position moves further rearward in the vehicle, and decreases as the occupant's position moves further forward in the vehicle. On the other hand, the inclination of the restraining surface when the airbag is inflated and deployed is uniquely determined by the shape of the base fabric that forms the airbag and the position and length of the tether provided inside the airbag. Therefore, if the occupant leans forward too much relative to the restraining surface when the airbag inflates and deploys, the occupant's head will be restrained by the airbag before the thorax, and conversely, if the occupant leans forward too little relative to the restraining surface when the airbag inflates and deploys, the occupant's chest will be restrained by the airbag before the head. In other words, in either case, there is room for improvement in restraining both the head and chest, which tilt forward during a frontal collision, with the airbag almost simultaneously and in a balanced manner. The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide an airbag device that is advantageous in restraining both the head and chest, which tilt forward during a frontal collision, in a balanced manner at approximately the same time with an airbag. [Means for solving the problem]

[0005] In order to achieve the above object, one embodiment of the present invention is an airbag device equipped with an airbag that inflates and deploys during a vehicle collision, and includes an occupant position detection unit that detects the position of a seated occupant in the fore-and-aft direction of the vehicle as the occupant position, a deployment shape adjustment unit that adjusts the restraining surface of the inflated and deployed airbag, and a restraining surface angle control unit that controls the deployment shape adjustment unit to control the restraining surface angle, when the restraining surface angle is the angle formed by a line connecting the point on the restraining surface of the inflated and deployed airbag that restrains the occupant's head and the point on the restraining surface of the inflated and deployed airbag, and a line connecting the vertical direction of the vehicle, and is characterized in that the control of the restraining surface angle by the restraining surface angle control unit is performed so that the restraining surface angle becomes larger the further rearward the occupant position detected by the occupant position detection unit is from the vehicle. In addition, one embodiment of the present invention is characterized in that the airbag device has a housing that houses an airbag and is attached to an instrument panel, and the deployed shape adjustment portion includes a base tether attached to the housing, a head restraint tether connected to the tip of the base tether and connected to a portion of the restraint surface that restrains the occupant's head, a chest restraint tether connected to the tip of the base tether and connected to a portion that restrains the occupant's chest, and a base tether length adjustment portion that changes the length of the base tether depending on the occupant's position. In addition, one embodiment of the present invention is characterized in that the base tether has multiple tethers of different lengths each connected to a pin held by the housing, and the base tether length adjustment unit drops off the pin connected to the base tether of an unused length depending on the occupant position detected by the occupant position detection unit. In addition, one embodiment of the present invention is characterized in that the base tether length adjustment unit includes a reel attached to the housing and around which the base tether is wound, and an actuator that rotates the reel to unwind and reel in the base tether, and the base tether length adjustment unit controls the rotation of the reel by the actuator in accordance with the occupant position detected by the occupant position detection unit. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the restraint surface angle control unit controls the deployment shape adjustment unit so that the restraint surface angle of the inflated and deployed airbag becomes smaller the further forward the occupant position detected by the occupant position detection unit is in the vehicle, and the restraint surface angle of the inflated and deployed airbag becomes larger the further rearward the occupant position detected by the occupant position detection unit is in the vehicle, which is advantageous in restraining both the head and chest of an occupant who leans forward in a frontal collision in a balanced manner almost simultaneously with the restraint surface of the airbag. Furthermore, if the deployment shape adjustment section is composed of a base tether, a head restraint tether, a chest restraint tether, and a base tether length adjustment section that changes the length of the base tether depending on the occupant position, this is advantageous in simplifying the configuration of the airbag device. Furthermore, if the base tether length adjustment unit is configured to drop the pin connected to the base tether of an unused length in accordance with the occupant position detected by the occupant position detection unit, the angle of the restraint surface of the inflating and deploying airbag can be controlled in stages in accordance with the occupant position detected by the occupant position detection unit, which is advantageous in restraining both the head and chest of an occupant who leans forward during a frontal collision in a balanced manner almost simultaneously with the restraint surface of the airbag. Furthermore, if the base tether length adjustment unit controls the rotation of the reel by the actuator in accordance with the occupant position detected by the occupant position detection unit, the angle of the restraint surface of the inflated and deployed airbag can be finely and steplessly controlled in accordance with the occupant position detected by the occupant position detection unit, which is even more advantageous in restraining both the head and chest, which lean forward during a frontal collision, in a balanced manner almost simultaneously with the restraint surface of the airbag. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram of the airbag restraint surface angle θ and the occupant's forward body tilt angle φ. FIG. [Figure 2] 1A and 1B are explanatory diagrams illustrating the operation of the airbag device according to the first embodiment, where (A) shows a case where the occupant is positioned toward the front of the vehicle and the restraint surface angle θ is small, and (B) shows a case where the occupant is positioned toward the rear of the vehicle and the restraint surface angle θ is large. [Figure 3] 1 is a block diagram showing a configuration of an airbag device according to a first embodiment. [Figure 4] 10A and 10B are explanatory diagrams illustrating the operation of an airbag device according to a second embodiment, where (A) shows a case where the occupant is positioned toward the front of the vehicle and the restraint surface angle θ is small, and (B) shows a case where the occupant is positioned toward the rear of the vehicle and the restraint surface angle θ is large. [Figure 5] FIG. 6 is a block diagram showing the configuration of an airbag device according to a second embodiment. [Figure 6] 10 is an explanatory diagram schematically illustrating the restraining surface angle θ, the upper body forward tilt angle φ, and the restraining state of the upper body of the occupant by the airbag. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) Hereinafter, an embodiment of the present invention will be described. In the following drawings, the symbol FR indicates the front of the vehicle, and the symbol UP indicates the top of the vehicle. 1, an airbag device 10A of this embodiment is configured to include an airbag 14 that is provided in an instrument panel 12 and inflates and deploys toward a front seat (not shown) in the event of a vehicle collision (frontal collision). Note that, although this embodiment will be described assuming that the front seat is a passenger seat, the present invention is also applicable to cases where the front seat is a driver's seat. The present invention is applicable to seats other than the front seats, and the airbag 14 may be provided in a location other than the instrument panel 12. Here, the restraining surface angle θ and the forward body tilt angle φ will be explained. As shown in FIG. 1, the restraint surface angle θ is the angle formed by a straight line L1 connecting a point P1 on the restraint surface 1402 of the inflated and deployed airbag 14 that restrains the head 18 of the occupant 16 that leans forward during a frontal collision and a point P2 that restrains the chest 20 of the occupant 16, and a straight line L0 that connects the vertical direction of the vehicle. In addition, the upper body forward tilt angle φ refers to the angle between a line L2 connecting the head 18 of the occupant 16 and the chest 20 of the occupant 16 and a line L0 connecting the vertical direction of the vehicle when the upper body of the occupant 16 seated in the front seat is tilted forward during a frontal collision.

[0009] As shown in FIG. 3, the airbag device 10A includes a housing 22 (see FIG. 1), an acceleration sensor 24, a seat slide sensor 26, an inflator 28, a deployment shape adjustment section 30, and a control device 32. The housing 22 accommodates the airbag 14 and is attached to the instrument panel 12, and is made of sheet metal. The acceleration sensor 24 detects the acceleration of the vehicle at the time of a frontal collision and supplies the detected acceleration to the control device 32 . The seat slide sensor 26 detects the position of the front seat in the fore-and-aft direction of the vehicle as the occupant position and supplies it to the control device 32. The seat slide sensor 26 constitutes an occupant position detection unit 34 that detects the position of the occupant 16 seated in the front seat in the fore-and-aft direction of the vehicle as the occupant position. The occupant position detector 34 is only required to be able to detect the position of the occupant 16 seated in the front seat in the longitudinal direction of the vehicle, and various conventionally known sensors can be used as the occupant position detector 34 . The inflator 28 supplies inflation gas into the airbag 14 to inflate and deploy the airbag 14.

[0010] The deployed shape adjusting portion 30 adjusts the restraining surface 1402 of the airbag 14 as it inflates and deploys. In this embodiment, the deployed shape adjustment section 30 includes a base tether 36 , a head restraint tether 38 , a chest restraint tether 40 , and a base tether length adjustment section 42 . The base tether 36 includes a first base tether 36A and a second base tether 36B that is longer than the first base tether 36A. The base end of the first base tether 36A is connected to a pin 44 held by an actuator 46, which will be described later. The proximal end of the second proximal tether 36B is attached to the housing 22. The head restraint tether 38 is connected to the tip of the base tether 36 and is connected to a portion of the restraint surface 1402 that restrains the head 18 of the occupant 16 . The chest restraint tether 40 is connected to the tip of the base tether 36 and is connected to a location where the chest 20 of the occupant 16 is restrained.

[0011] The base tether length adjustment unit 42 detaches the pin 44 connected to the base tether 36 of an unused length depending on the occupant position, and in this embodiment, detaches the pin 44 connected to the first base tether 36A. Specifically, the proximal tether length adjustment section 42 includes an actuator 46 that is attached to the housing 22 and that detachably holds the pin 44. In other words, the pin 44 is held in the housing 22 via the actuator 46. The actuator 46 is operated by an actuation signal from the control device 32 to cause the pin 44 to drop off the proximal end of the first proximal tether 36A, thereby separating the proximal end of the first proximal tether 36A from the housing 22.

[0012] The control device 32 includes an airbag control unit 48 and a restraint surface angle control unit 50 . The airbag control unit 48 detects the occurrence of a frontal collision based on the detection signal from the acceleration sensor 24 and supplies an activation signal to the inflator 28, which then activates the inflator 28 and inflates and deploys the airbag 14 from the instrument panel 12 toward the front seats.

[0013] The restraint surface angle control unit 50 controls the restraint surface angle θ by controlling the unfolded shape adjustment unit 30, and the control of the restraint surface angle θ by the restraint surface angle control unit 50 is performed so that the restraint surface angle θ becomes larger the further rearward the occupant position detected by the seat slide sensor 26 (occupant position detection unit 34) is from the vehicle.

[0014] Next, the effects will be described. When the occupant 16 sits in the front seat and sets the position of the front seat in the longitudinal direction of the vehicle, the occupant position is detected by the seat slide sensor 26. When the airbag control unit 48 detects a frontal collision based on the detection signal from the acceleration sensor 24, it supplies an activation signal to the inflator 28 to inflate and deploy the airbag 14. At this time, the restraint surface angle control unit 50 controls the deployment shape adjustment unit 30 so that the restraint surface angle θ increases as the occupant position detected by the seat slide sensor 26 moves further rearward in the vehicle. That is, the base tether length adjustment section 42 of the deployed shape adjustment section 30 changes the length of the base tether 36 in accordance with the occupant position by dropping a pin 44 connected to the first base tether 36, which is the base tether 36 of an unused length, in accordance with the occupant position detected by the seat slide sensor 26.

[0015] In detail, as shown in FIG. 2(A), when the occupant position detected by the seat slide sensor 26 is near the front of the vehicle and the occupant forward tilt angle φ during a frontal collision is small, the restraint surface angle control unit 50 controls the deployment shape adjustment unit 30 so that the restraint surface angle θ of the inflated and deployed airbag 14 becomes smaller, thereby bringing the restraint surface angle θ closer to the occupant forward tilt angle φ. Specifically, the attitude of the airbag 14 is controlled by connecting the head restraint tether 38 and the chest restraint tether 40 to the housing 22 via the short first base tether 36A, and the restraint surface angle θ of the inflated and deployed airbag 14 is controlled to be small. In this case, the second base tether 36B, which is longer than the first base tether 36A, is slack and does not function. As a result, when the restraint surface angle θ approaches the occupant's forward tilt angle φ during a frontal collision (in other words, when the restraint surface angle θ matches or nearly matches the occupant's forward tilt angle φ), both the head 18 and chest 20 of the occupant 16 are restrained in a balanced manner by the restraint surface 1402 of the airbag 14 almost simultaneously.

[0016] On the other hand, as shown in Figure 2(B), when the occupant is positioned toward the rear of the vehicle and the occupant's forward tilt angle φ during a frontal collision is large, the restraint surface angle control unit 50 controls the deployment shape adjustment unit 30 so that the restraint surface angle θ of the inflated and deployed airbag 14 becomes larger, thereby bringing the restraint surface angle θ closer to the occupant's forward tilt angle φ. Specifically, by activating the actuator 46 of the base tether length adjustment section 42 of the deployed shape adjustment section 30 and causing the pin 44 to drop off from the base end of the unused first base tether 36A, the unused first base tether 36A is detached from the housing 22, and the head restraint tether 38 and the chest restraint tether 40 are connected to the housing 22 via the longer second base tether 36B, thereby controlling the attitude of the airbag 14 and controlling the restraint surface angle θ of the inflated and deployed airbag 14 to be larger. As a result, both the head 18 and chest 20 of the occupant 16 who leans forward in a state where the restraining surface angle θ approaches the occupant forward tilt angle φ during a frontal collision are restrained in a balanced manner by the flat restraining surface 1402 of the airbag 14 at approximately the same time.

[0017] That is, as shown in FIG. 6, by controlling the restraint surface angle θ to be small when the upper body forward tilt angle φ is small, and by controlling the restraint surface angle θ to be large when the upper body forward tilt angle φ is large, the restraint surface angle θ becomes close to the occupant forward tilt angle φ, and both the head 18 and chest 20, which tilt forward during a frontal collision, are restrained in a balanced manner by the restraint surface 1402 of the airbag 14 almost simultaneously. Therefore, as shown in Figure 6, this is advantageous in avoiding the situation where the head 18 is restrained by the airbag 14 before the chest 20 due to a small restraint surface angle θ despite a large upper body forward tilt angle φ, or the situation where the head 18 is restrained by the airbag 14 before the chest 20 due to a large restraint surface angle θ despite a small upper body forward tilt angle φ.

[0018] Furthermore, in this embodiment, the deployed shape adjustment section 30 is composed of a base tether 36, a head restraint tether 38, a chest restraint tether 40, and a base tether length adjustment section 42 that changes the length of the base tether 36 depending on the occupant position, which is advantageous in simplifying the configuration of the airbag device 10A.

[0019] In addition, in this embodiment, the base tether 36 consists of two pieces, the first base tether 36A and the second base tether 36B, and the pin 44 connected to the unused length of the base tether 36 (first base tether 36A) is dropped depending on the occupant position detected by the occupant position detection unit 34. This makes it possible to control the restraint surface angle θ in stages (two stages), which is advantageous in restraining both the head 18 and chest 20 of the occupant 16 in a balanced manner almost simultaneously with the restraint surface 1402 of the airbag 14 when the restraint surface angle θ approaches the occupant forward tilt angle φ during a frontal collision.

[0020] In addition, N (N is a natural number greater than or equal to 3) base tethers 36 of different lengths and N actuators 46 may be provided as base tethers 36, each connected to a pin 44 held by each actuator 46, and the base tether length adjustment unit 42 may drop the pin 44 connected to the base tether 36 of an unused length from among the N base tethers 36 depending on the occupant position. In this case, the restraining surface angle θ of the inflating airbag 14 can be precisely controlled in N stages according to the occupant position detected by the occupant position detection unit 34, which is more advantageous in that the restraining surface 1402 of the airbag 14 can restrain both the head 18 and chest 20, which tilt forward when the restraining surface angle θ approaches the occupant forward tilt angle φ during a frontal collision, in a balanced manner at almost the same time.

[0021] (Second embodiment) Next, an airbag device 10B according to a second embodiment will be described with reference to FIGS. In the following embodiments, parts and members similar to those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the differences. The second embodiment differs from the first embodiment in that there is only one proximal tether 36 and in the configuration of the proximal tether length adjustment section 42. As shown in FIGS. 4(A), (B) and 5, the base tether length adjustment section 42 includes a reel 52 and a motor 54 as an actuator. Reel 52 is attached to housing 22 and is where proximal tether 36 is wound. The motor 54 rotates the reel 52 to unwind and reel in the base tether 36 . The base tether length adjustment unit 42 controls the rotation of the reel 52 by the motor 54 in accordance with the occupant position.

[0022] Next, the effects will be described. In the second embodiment, when an occupant 16 sits in the front seat and sets the position of the front seat in the fore-and-aft direction of the vehicle, the occupant position is detected by the seat slide sensor 26, and at this time, the restraint surface angle control unit 50 controls the deployment shape adjustment unit 30 so that the restraint surface angle θ increases as the occupant position detected by the seat slide sensor 26 moves further rearward in the vehicle. That is, the base tether length adjustment section 42 of the deployed shape adjustment section 30 adjusts the length of the base tether 36 according to the occupant position, in other words, each time the occupant position changes, by controlling the rotation of the reel 52 by the motor 54.

[0023] In detail, as shown in Figure 4(A), when the occupant position detected by the seat slide sensor 26 is near the front of the vehicle and the occupant forward tilt angle φ during a frontal collision is small, the restraint surface angle control unit 50 controls the deployment shape adjustment unit 30 to reduce the restraint surface angle θ of the inflated and deployed airbag 14, thereby bringing the restraint surface angle θ closer to the occupant forward tilt angle φ. Specifically, the base tether 36 is shortened by rotating the reel 52 in the winding direction using the motor 54 of the base tether length adjustment unit 42 of the deployed shape adjustment unit 30, and the head restraint tether 38 and the chest restraint tether 40 are connected to the housing 22 via the shortened base tether 36, thereby controlling the attitude of the airbag 14 and controlling the restraint surface angle θ of the inflated and deployed airbag 14 to be smaller. When the airbag control unit 48 detects a frontal collision based on the detection signal from the acceleration sensor 24, it sends an activation signal to the inflator 28 to inflate and deploy the airbag 14, so that both the head 18 and chest 20 of the occupant 16, who leans forward during a frontal collision with the restraint surface angle θ approaching the occupant forward tilt angle φ, are restrained in a balanced manner by the restraint surface 1402 of the airbag 14 almost simultaneously.

[0024] On the other hand, as shown in Figure 4(B), when the occupant is positioned toward the rear of the vehicle and the occupant's forward tilt angle φ during a frontal collision is large, the restraint surface angle control unit 50 controls the deployment shape adjustment unit 30 to increase the restraint surface angle θ of the inflated and deployed airbag 14, thereby bringing the restraint surface angle θ closer to the occupant's forward tilt angle φ. Specifically, the base tether 36 is lengthened by rotating the reel 52 in the unwinding direction using the motor 54 of the base tether length adjustment unit 42 of the deployed shape adjustment unit 30, and the head restraint tether 38 and the chest restraint tether 40 are connected to the housing 22 via the lengthened base tether 36, thereby controlling the posture of the airbag 14 and increasing the restraint surface angle θ of the inflated and deployed airbag 14. When the airbag control unit 48 detects a frontal collision based on the detection signal from the acceleration sensor 24, it sends an activation signal to the inflator 28 to inflate and deploy the airbag 14, so that both the head 18 and chest 20 of the occupant 16, who leans forward during a frontal collision with the restraint surface angle θ approaching the occupant forward tilt angle φ, are restrained in a balanced manner by the restraint surface 1402 of the airbag 14 almost simultaneously.

[0025] In the second embodiment, as in the first embodiment, it goes without saying that the effect of both the head 18 and the chest 20, which tilt forward during a frontal collision, being restrained by the restraining surface 1402 of the airbag 14 at approximately the same time in a balanced manner is achieved. In addition, in the second embodiment, the restraining surface angle θ of the inflated and deployed airbag 14 can be finely and steplessly controlled in accordance with the occupant position detected by the seat slide sensor 26, which is even more advantageous in that both the head 18 and the chest 20, which tilt forward during a frontal collision, are restrained by the restraining surface 1402 of the airbag 14 at approximately the same time in a balanced manner. [Explanation of symbols]

[0026] 10A, 10B Airbag device 12 Instrument panel 14 Airbags 1402 Restraint surface 16 crew members 18 head 20 Chest 22 Housing 24 Acceleration sensor 26 Seat slide sensor 28 Inflator 30 Expanded shape adjustment section 32 Control device 34 Occupant position detection unit 36 Proximal Tether 36A First base tether 36B Second base tether 38 Head Restraint Tether 40 Chest Restraint Tether 42 Base tether length adjustment part 44 pin 46 Actuator 48 Airbag control unit 50 Constraint surface angle control section 52 reels 54 Motor L0: A straight line connecting the top and bottom of the vehicle L1: A straight line connecting the point where the occupant's head is restrained and the point where the occupant's chest is restrained L2: A straight line connecting the occupant's head and chest

Claims

1. An airbag device including an airbag that inflates and deploys during a vehicle collision, an occupant position detection unit that detects the position of a seated occupant in the vehicle front-rear direction as an occupant position; a deployment shape adjusting unit that adjusts a restraining surface of the inflated and deployed airbag; a restraint surface angle control unit that controls the deployment shape adjustment unit to control the restraint surface angle, where the angle formed by a line connecting a portion of the restraint surface of the inflated and deployed airbag that restrains the head of the occupant and a portion that restrains the chest of the occupant and a line connecting the vehicle vertical direction is defined as the restraint surface angle, The restraint surface angle control unit controls the restraint surface angle so that the restraint surface angle increases as the occupant position detected by the occupant position detection unit moves further rearward of the vehicle. An airbag device characterized by:

2. The airbag device has a housing that houses an airbag and is attached to an instrument panel, The deployed shape adjustment unit includes a base tether attached to the housing, a head restraint tether connected to the tip of the base tether and connected to a portion of the restraint surface that restrains the occupant's head, a chest restraint tether connected to the tip of the base tether and connected to a portion that restrains the occupant's chest, and a base tether length adjustment unit that changes the length of the base tether depending on the occupant's position.

2. The airbag device according to claim 1.

3. The base tether is provided with a plurality of tethers of different lengths each connected to a pin held by the housing, the base tether length adjustment unit drops off a pin connected to the base tether of an unused length in accordance with the occupant position detected by the occupant position detection unit.

3. The airbag device according to claim 2.

4. the base tether length adjustment unit includes a reel attached to the housing and around which the base tether is wound, and an actuator that rotates the reel to unwind and reel in the base tether, the base tether length adjustment unit controls the rotation of the reel by the actuator in accordance with the occupant position detected by the occupant position detection unit.

3. The airbag device according to claim 2.

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