Airbag system, its mounting method, and vehicle seat

Abstract

To restrict behavior of an airbag configured to be inflated and deployed by a supplied gas with a tether.SOLUTION: An airbag 21 of an airbag device 19 is fixed to a side edge of a seat back 17 with fixing parts SP1, SP2. Further, a tether 40 in which one end 41 is fastened to a position away from the fixing parts SP1, SP2 and the other end 43 is fastened to the side edge of the seat back 17 is fastened to the airbag 21. Fastening positions of the one end 41 and the other end 43 of the tether 40 are located at positions such that a power point and a point of action of a force applied to the airbag 21 by the tether 40 when the airbag 21 is inflated are located below a first fixing part SP1 which is the highest fixing part in a vertical direction of the seat back 17 and above a second fixing part SP2 which is the lowest fixing part.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to an airbag device, a method for attaching the same, and a vehicle seat.

Background Art

[0002] Various airbag devices have been proposed to ensure the safety of passengers in vehicles such as automobiles. For example, in Patent Document 1 below, when an impact is applied to the side wall near the seat on which the passenger is seated, an airbag is deployed on the side opposite to the side wall side (hereinafter referred to as the far side) as viewed from the seat, and an airbag device for ensuring the safety of the passenger is disclosed. This airbag device aims to enhance the safety of the passenger against an impact from the side wall side.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such an airbag device, the airbag before inflation is folded and stored in the side portion of the seat back. When the airbag device operates, the airbag expands by the gas from the inflator while a part of it remains fixed to the seat. Therefore, in such an airbag device, in addition to the fixing portion that fixes the airbag to the seat, a connecting member (hereinafter referred to as a tether) that connects the airbag and the seat is provided, and it has also been proposed to regulate the behavior of the airbag during deployment and inflation.

[0005] The inventors have studied the relationship between the form of the tether and the behavior of the airbag during deployment in such an airbag device, clarified a way to make the movement of the airbag closer to the desired behavior, and completed the airbag device of the present disclosure. [Means for solving the problem]

[0006] This disclosure can be implemented in the following forms or applications:

[0007] (1) A first embodiment of the present disclosure is an airbag device attached to the seat back of a vehicle seat. The airbag device comprises an airbag having at least two fixing points fixed to the side edge of the seat back, which is inflated by supplying inflation gas from a folded state, and a tether having one end fastened to the airbag at a position away from the fixing points and the other end fastened to the side edge of the seat back. Here, the fastening position of the one end and the other end of the tether is such that the point of force application and the point of application of the force acting on the airbag by the tether when the airbag inflates are below the first fixing point, which is the uppermost fixing point in the vertical direction of the seat back, and above the second fixing point, which is the lowest fixing point. With this airbag device, it is possible to suppress the generation of an undesirable axis of rotation in the inflated airbag, and as a result, the rotation of the airbag can be suppressed. (2) A second embodiment of the present disclosure relates to a method for attaching an airbag to the seat back of a vehicle seat. The method involves fixing the airbag to the side edge of the seat back by at least two fastening points, fastening one end of a tether to the airbag at a position spaced apart from the fastening points, and fastening the other end of the tether to the side edge of the seat back, and when fastening the tether, the fastening position of the one end and the other end of the tether is such that the point of force application and the point of application of the force that the tether exerts on the airbag when the airbag inflates are below the first fastening point, which is the uppermost fastening point in the vertical direction of the seat back, and above the second fastening point, which is the lowest fastening point. This prevents the creation of an undesirable axis of rotation in the inflated airbag and allows the airbag to be easily attached. (3) A third embodiment of the present disclosure is a vehicle seat. This vehicle seat comprises a seat body on which an occupant can sit; an inflator that generates gas when a collision in the vehicle is detected or predicted; an airbag having at least two fixing points fixed to the side edge of the seat back of the seat body, which inflates and deploys from a folded storage state upon receiving gas from the inflator; and a tether, one end of which is fastened to the airbag at a position separated from the fixing points, and the other end of which is fastened to the side edge of the seat back. In this vehicle seat, the fastening position of the one end and the other end of the tether is such that the point of force application and the point of application of the force that the tether exerts on the airbag when the airbag inflates are below the first fixing point, which is the uppermost fixing point in the vertical direction of the seat back, and above the second fixing point, which is the lowest fixing point. This allows the airbag to inflate and deploy from its folded, stored state when a collision is detected or predicted in the vehicle, while also suppressing the creation of an undesirable axis of rotation. As a result, the rotation of the airbag is suppressed, thereby enhancing its ability to protect occupants. [Brief explanation of the drawing]

[0008] [Figure 1] An explanatory diagram showing a part of a vehicle equipped with the airbag measure of the embodiment in a plan view. [Figure 2] An explanatory diagram showing the arrangement of the left and right seats, passengers, and airbag systems in a vehicle, viewed from the front. [Figure 3] A schematic diagram illustrating the stowed state of the airbag device in the seat, viewed from above. [Figure 4] An explanatory diagram showing the configuration of an airbag system attached to a seat, using a side view from inside the vehicle. [Figure 5] A schematic diagram illustrating the deployment of an airbag from a front view inside a vehicle. [Figure 6] Similarly, this is an explanatory diagram showing what the airbag looks like when it is fully inflated. [Figure 7]An explanatory diagram showing the relationship between the airbag fixing position and the tether attachment position in the first embodiment. [Figure 8] A schematic diagram illustrating the mounting position of the tether and the movement of the airbag in the embodiment, viewed from above. [Figure 9] An explanatory diagram illustrating the tether mounting position and airbag movement in the comparative example. [Figure 10] An explanatory diagram showing the relationship between the airbag fixing position and the tether attachment position in the second embodiment. [Figure 11] An explanatory diagram showing the relationship between the airbag fixing position and the tether attachment position in the third embodiment. [Figure 12] An explanatory diagram showing the relationship between the airbag fixing position and the tether attachment position in the fourth embodiment. [Figure 13] A process diagram showing how to install an airbag. [Modes for carrying out the invention]

[0009] A. First Embodiment: (A1) Overall structure: The configuration of the far-side airbag system in a vehicle according to the first embodiment will now be described. As shown in Figures 1 and 2, in a vehicle 10 as an example of a vehicle, the vehicle width direction is called the X direction, the longitudinal direction of the vehicle 10 is called the Y direction, and the vehicle height direction is called the Z direction. Furthermore, as shown in the figures, the side of the steering wheel 15 of a left-hand drive vehicle (driver's side) is called the +X direction, and the opposite side (passenger side) is called the -X direction. The forward direction of the vehicle 10 is called the +Y direction, the reverse direction is called the -Y direction, the height direction is called the +Z direction, and the direction toward the ground is called the -Z direction. Although these directions are shown as appropriate in each figure, the "+" notation will be omitted in the figures and the following explanation.

[0010] The sides of the vehicle 10 are provided with side walls 11 and 12, consisting of doors and pillars. Between the side walls 11 and 12, there are multiple seats (two in this example) arranged in the X direction of the vehicle 10. The seat bodies 13 and 14 that make up the seats each consist of a seat cushion 16, a seat back 17, and a headrest 18. The seats may also be fitted with armrests and the like. The headrest 18 is optional. The seat cushion 16 and seat back 17 may be separate or integrated.

[0011] The seat cushion 16 is configured to support the lower bodies of passengers P1 and P2. The seat back 17 is configured to stand up from the rear end of the seat cushion 16 to support the upper bodies of passengers P1 and P2. The headrest 18 is provided at the upper end of the seat back 17 and is configured to support the heads T of passengers P1 and P2.

[0012] When an impact is applied from the side to the side wall 11 or side wall 12 of the vehicle 10, passengers P1 and P2 seated in the seat body 13 or 14 on the side furthest from the impacted side wall 11 or 12 will be thrown towards the side wall 11 or 12 that was impacted. For this reason, the vehicle 10 is equipped with a far-side airbag device 19 that restrains and protects passengers P1 and P2 seated in the seat body 13 or 14 on the side furthest from the impacted side wall 11 or 12 when an impact is applied from the side to the side wall 11 or 12.

[0013] (A2) Far-side airbag configuration: As shown in FIG. 2, the far-side airbag device 19 is housed in the seat back 17 of the seat bodies 13 and 14 in the vehicle 10. The structures around the far-side airbag device 19 in the seat body 13 and the seat body 14 are the same except that they are symmetric (left-right symmetric) in the X direction of the vehicle 10. Therefore, hereinafter, the configuration of the far-side airbag device 19 will be described taking the side housed in the seat body 13 as an example. FIG. 3 schematically shows the configuration of the far-side airbag device 19 in the seat body 13 on the driver's seat side in a left-hand drive vehicle in a top view. In the seat body 13, the far-side airbag device 19 is fixed to the -X direction side at the upper part of the frame 20 forming the skeleton of the seat back 17. The far-side airbag device 19 is located immediately below the skin 17a of the seat back 17. The skin 17a is formed to be cleavable by the inflation of the airbag described later.

[0014] The far-side airbag device 19 includes an airbag 21, an inflator 22, and a tether described later. The airbag 21 is fixed to the upper part of the frame 20 in the seat back 17 of the seat body 13 in a folded state. The inflator 22 is a device that supplies inflation gas to the airbag 21 during a collision. The inflator 22 is supported in a state covered by a retainer 23. The retainer 23 is fixed to the frame 20 together with the airbag 21 by bolts 30 and nuts 31 while supporting the inflator 22.

[0015] As shown in FIG. 4, the far-side airbag device 19 includes a control device 24 that controls the supply of inflation gas to the airbag 21 by the inflator 22. An impact sensor 25 composed of an acceleration sensor or the like provided on the side wall portions 11, 12, etc. is electrically connected to the control device 24. The impact sensor 25 detects an impact applied to the side wall portions 11, 12 from the side (Y or -Y direction) of the vehicle 10. The control device 24 operates the inflator 22 based on the detection signal from the impact sensor 25 to supply inflation gas to the airbag 21. The control device 24 is realized by a discrete circuit configuration in order to operate the inflator 22 at the fastest speed upon receiving the signal from the impact sensor 25. Of course, a configuration using a high-speed operable one-chip microcomputer or the like and operating according to a pre-stored program is also acceptable. Instead of the impact sensor 25, a configuration may be adopted in which the control device 24 inputs signals from a video camera, a millimeter-wave radar, or a Lidar, etc., thereby predicting a collision and operating the inflator 22.

[0016] When inflation gas is supplied from the inflator 22 to the airbag 21, the airbag 21 rapidly inflates. One end of the airbag 21 is fixed to the seat back 17 by a fixing portion as will be described later. For this reason, the airbag 21 cleaves the skin 17a while leaving the portion near the inflator 22 inside the seat back 17 and pops out forward from the seat back 17. The airbag 21 that has popped out from the seat back 17 expands and inflates in the Y direction between the seat body 13 and the seat body 14. In FIG. 3, the folded airbag 21 is shown by a solid line, and a part of the deployed and inflated airbag 21 is shown by a two-dot chain line.

[0017] In the event of a collision with the side walls 11 and 12, the inflator 22 activates upon receiving a signal from the control device 24, supplying inflation gas to the airbag 21, and the airbag 21 of the seat body 13 and 14 on the side furthest from the impacted side walls 11 and 12 is ejected from the seat back 17. Figure 5 schematically shows the state in which the far-side airbag device 19 of the seat body 13 is activated. The ejected airbag 21 unfolds with the main protection section 26 and the sub-protection section 27 connected, thereby protecting the area from the chest to the head T of the occupant P1 seated in the seat body 13, which is about to fall towards the side wall 11 on the side that was impacted. If a collision occurs with the opposite side wall 12, the far-side airbag device 19 of the seat body 14 activates, and its airbag 21 unfolds and inflates in the Y direction from the side edge of the seat back 17, restraining and protecting the occupant P2.

[0018] As a result, passengers P1 and P2 seated in the seat bodies 13 and 14 on the side furthest from the side wall 11 and 12 that was impacted are less likely to come into contact with or interfere with other passengers P2 and P1 seated in the seat bodies 14 and 13 on the side closer to the side wall 11 and 12 that was impacted, or with the interior components of the vehicle 10.

[0019] (A3) Airbag configuration and fastening: Next, the structure and fixing of the airbag 21 will be described. As schematically shown in Figure 5, the airbag 21 comprises a bag-shaped main protective section 26 and a bag-shaped sub-protective section 27 that is smaller than the main protective section 26. The sub-protective section 27 has an internal space continuous with that of the main protective section 26. The airbag 21 is formed into a bag shape by folding a single base fabric in half and overlapping it in the thickness direction, and sewing the periphery of the overlapped portion together. The main protective section 26 and the sub-protective section 27 may be sewn separately and then joined together.

[0020] The airbag 21 is secured to the frame 20 inside the seatback 17 by its sewn side. This securing mechanism is shown in Figures 6 and 7. As illustrated, the main protective portion 26 of the airbag 21 has a fixing portion 28 on its sewn side, and is secured to the side edge 17S of the seatback 17, specifically to the frame 20, at two locations: a first fixing portion SP1 and a second fixing portion SP2. In this example, the first fixing portion SP1 is located above the second fixing portion SP2 in the Z direction. Note that there may be three or more fixing points.

[0021] The airbag 21 is equipped with a wide, strip-shaped tether 40. The width Lt of this tether 40 is approximately equal to the range LL from the first fixing part SP1 to the second fixing part SP2, and is at least about 80% of the range LL. One end 41 of the tether 40 is fastened at a position separated from the first and second fixing parts SP1 and SP2 of the airbag 21, and the other end 43 of the tether 40 is fastened to the frame 20 of the side edge 17S of the seat back 17. Specifically, one end 41 of the tether 40 is fastened at two points on the inflated main protective part 26, either at the position furthest from the fixing part 28 on the seat back 17 side, or at a position that wraps around to the back side from the furthest position. The points where it is fastened to the main protective part 26 are called one-end fastening parts CP1 and CP2. On the other hand, the other end 43 of the tether 40 is fastened to the side edge 17S of the seat back 17, below the first fixing part SP1 of the airbag 21 and above the second fixing part SP2. The parts fastened to the seat back 17 are called the other end fastening parts AP1 and AP2. Fastening may be done by rivets or by sewing. Alternatively, it may be done by bonding or welding. The material of the tether 40 may be the same as the material of the airbag 21, for example, an airbag base fabric made of woven nylon 66 that has undergone post-processing, or it may be different. For example, PET may be used as the material. It does not need to be elastic as long as it is in the form of fabric.

[0022] As shown in Figure 7, the fastening portions CP1 and CP2 at one end and the fastening portions AP1 and AP2 at the other end are all located below the first fixing portion SP1 and above the second fixing portion SP2 of the airbag 21. Therefore, the airbag 21 only rotates around the axis connecting the first fixing portion SP1 and the second fixing portion SP2. Figure 8 schematically shows the fastening position relationship of the tether 40 to the main protective portion 26 in a top view. In the figure, the main protective portion 26 at the position assumed when the occupant P1's head T is not pressed against the airbag 21 is drawn with a dashed line, and the main protective portion 26 at the position assumed when the head T pushes the main protective portion 26 in the -X direction is drawn with a solid line. When the occupant P1's head T is pressed against the main protective portion 26, the main protective portion 26 moves with deformation in the -X direction.

[0023] At this time, the distance from the fastening portions CP1, CP2 at one end of the tether 40 to the fastening portions AP1, AP2 at the other end increases by an amount of movement Md1 compared to before the movement. Therefore, a force opposing the movement and deformation of the main protective portion 26 is acted on the main protective portion 26 by the tether 40. Since the deformation and movement of the main protective portion 26 originate from the first fixing portion SP1 and the second fixing portion SP2, for convenience, the fastening portions AP1, AP2 at the other end of the tether 40 are considered as the point of force application, and the fastening portions CP1, CP2 at the one end are considered as the point of application. In this embodiment, a single wide tether 40 is used, but by considering that fastening is performed at two locations at both ends in the width direction of the tether 40, as shown in Figure 7, we can consider a line of force V1 with the fastening portion AP1 at the other end as the point of force application and the fastening portion CP1 at the one end as the point of application, and a line of force V2 with the fastening portion AP2 at the other end as the point of force application and the fastening portion CP2 at the one end as the point of application. Here, the line of force represents the linear path through which the tether 40 exerts force to pull the main protective part 26 back toward the seat back 17 when the main protective part 26 tries to move away from the seat back 17. In this case, assuming that the forces applied to the main protective part 26 by both are combined, the point of force application ap and the point of application cp of the virtual line of force vv will be located below the first fixing part SP1, which is the uppermost fixing part of the seat back 17 in the Z direction, and above the second fixing part SP2, which is the lowest fixing part.

[0024] For the sake of clarity, the fastening points on one end of the tether 40 on the main protective section 26 side and the fastening points on the other end of the tether 40 on the seat back 17 side have been described as two locations each. In reality, it is also possible to sew and fix the fastening points on both ends across the width direction. Even in such cases, it is possible to assume a large number of points of force application and a large number of points of application, and to synthesize the large number of force lines acting from these points of force application to the points of application. In this way, the point of force application ap and the point of application cp of the virtual force line vv will be located below the first fixing part SP1, which is the uppermost fixing part of the seat back 17 in the Z direction, and above the second fixing part SP2, which is the lowest fixing part.

[0025] (A4) Operation and effects of the far-side airbag device 19: If, for example, an impact is applied from the side to the side wall portion 11 of the vehicle 10, the occupant P1 seated in the seat body 13 on the side furthest from the side wall portion 11 will attempt to fall towards the side wall portion 11. At this time, the airbag 21, which is folded and stored inside the seat back 17, on the side edge of the seat back 17 of the seat body 13 that is closer to the side wall portion 11, receives inflation gas supplied from the inflator 22 and deploys and inflates from the seat back 17 in the Y direction.

[0026] As a result, the airbag 21 deploys and inflates with the main protective section 26 laterally corresponding to the area from the occupant P21's chest to its head T, while the sub-protective section 27 deploys and inflates in front of the occupant P1's head T. This causes the occupant P1's head T, which is about to fall towards the side wall 11, to strike the main protective section 26. At this time, the occupant P1 pushes the main protective section 26 towards the side wall 11, and a force acts on the airbag 21 that attempts to rotate it, with the axis connecting the first fixing section SP1 and the second fixing section SP2 of the airbag 21 as the center of rotation. In the far-side airbag device 19 of the first embodiment, the main protective section 26 is fastened by a tether 40, and as shown by the virtual force line vv, the force due to the tether 40 acts between the first fixing section SP1 and the second fixing section SP2, so the rotation of the airbag 21 is sufficiently suppressed.

[0027] This point will be explained with reference to a comparative example. Figure 9 shows the arrangement of the tether 40R as a comparative example. In this comparative example, the fastening part AP on the other end of the tether 40R is located below the first fixing part SP1, which is the uppermost fixing part of the seat back 17 in the Z direction, and above the second fixing part SP2, which is the lowest fixing part. However, the fastening part CP on the one end that fastens the tether 40R to the main protective part 26 is located higher than the first fixing part SP1. Therefore, the line segment L1 connecting the fastening part AP on the other end, which is the point of force application, and the fastening part CP on the one end, which is the point of application, is neither orthogonal nor nearly orthogonal to the line segment L2 connecting the first fixing part SP1 and the second fixing part SP2. As a result, the airbag 21 can rotate around an axis AX that is tilted at an angle θ with respect to the line segment L2. As in this embodiment, if the fastening parts CP1, CP2 at one end and the fastening parts AP1, AP2 at the other end are located in a range LL that is below the first fixing part SP1, which is the uppermost fixing part of the seat back 17 in the Z direction, and above the second fixing part SP2, which is the lowest fixing part, then the inclination of line segment L1 will be within a predetermined range, the inclination of axis AX will be small, and no rotation will occur around axis AX. Therefore, the tether 40 can restrict the movement of the airbag 21 to the range necessary for protecting the occupant P1. In this embodiment, the virtual force line vv can be considered as line segment L1, so the virtual force line vv is approximately perpendicular to line segment L2. As a result, the inclination θ of axis AX is almost zero, so even if force is applied to the airbag 21 by the tether 40, the airbag 21 will not be rotated in an undesirable direction.

[0028] Furthermore, the position of the fastening portions CP1 and CP2 at the end of the wide tether 40 to the airbag 21 is below the first fixing portion SP1 and above the second fixing portion SP2, and the position where the other end of the wide tether 40 is fastened to the side edge of the seat back 17 is below the first fixing portion SP1 and above the second fixing portion SP2. As a result, the force that the tether 40 exerts on the airbag 21 acts approximately parallel to the X direction with respect to the airbag 21, further suppressing the rotation of the airbag 21 around the Y axis by the tether 40. This prevents the upper or lower end of the airbag 21 from rotating and being pulled too far towards the seat body 13.

[0029] Furthermore, in this embodiment, one end 41 of the tether 40 is fastened to the airbag 21 by the one-end fastening parts CP1 and CP2 at the position furthest from the fixing part 28 on the seat back 17 side in the inflated main protective part 26, or at a position that wraps around to the back side from the furthest position. Therefore, when the head T of the occupant P1 is pressed against the inflated airbag 21, the force that the tether 40 exerts in the direction of pulling the airbag 21 can be increased. As a result, the rotation of the airbag 21 can be further suppressed.

[0030] As shown in Figure 8, the main protective section 26 moves with deformation in the -X direction. However, if a shorter tether than the tether 40 of this embodiment is used, and one end 41a is fastened to the airbag 21 at a location closer to the seat back 17, then, as shown in the figure, the amount of movement Md2 of this end 41a is smaller than the amount of movement Md1 when the end 41 is fastened to the position furthest from the fixing part 28 on the seat back 17 side in the inflated main protective section 26, or to a position that wraps around to the back from the furthest position. Therefore, in this case, the force trying to pull the airbag 21 back towards the seat back 17 is small. In this embodiment, as shown in Figure 8, one end 41 of the tether 40 is fastened at two locations in the inflated main protective section 26, either at the position furthest from the fixing part 28 on the seat back 17 side, or to a position that wraps further to the back from the furthest position. As a result, the head T of the occupant P1 is pressed against the main protective section 26, and a large tension can be applied to the airbag 21. Therefore, the far-side airbag device 19 of this embodiment can further suppress the rotation of the airbag 21, which consists of a main protective section 26 and a sub-protective section 27.

[0031] B. Second Embodiment: Next, the configuration of the far-side airbag device 19B of the second embodiment will be described. The far-side airbag device 19B of the second embodiment is the same as the first embodiment in terms of its mounting position in the vehicle 10 and the mechanism by which the control device 24 operates the inflator 22, but the configuration of the tether attached to the airbag 21 is different.

[0032] As shown in Figure 10, the far-side airbag device 19B of the second embodiment uses two thin tethers 401 and 402 instead of the single wide tether 40 of the first embodiment. Similar to tether 40, one end 411 and 412 of each tether 401 and 402 are fastened at a position away from the first and second fixing parts SP1 and SP2 of the airbag 21, and the other ends 431 and 432 of each tether 401 and 402 are fastened to the frame 20 on the side edge of the seat back 17. Similar to the first embodiment, the locations where they are fastened to the main protective part 26 are called one-end fastening parts CP1 and CP2. The one-end fastening parts CP1 and CP2 to which the one ends 411 and 412 of the tethers 401 and 402 are fastened are located at the position furthest from the fixing part 28 on the seat back 17 side in the inflated main protective part 26, or at a position that wraps around to the rear side from the furthest position. Furthermore, the fastening portions CP1 and CP2 at one end are located below the first fixing portion SP1 and above the second fixing portion SP2 of the airbag 21 in the Z direction.

[0033] Similarly, the other ends 431 and 432 of the tethers 401 and 402 are fastened to the side edge of the seat back 17, below the first fixing part SP1 of the airbag 21 and above the second fixing part SP2. The points where they are fastened to the seat back 17 are called the other end fastening parts AP1 and AP2. As in the first embodiment, the tethers 401 and 402 may be fastened by rivets or the like, by sewing, or by bonding or welding.

[0034] In the second embodiment, as in the first embodiment, when a collision occurs on the far side of the occupant P1, the main protective section 26 is pushed toward the side wall section 11 by the occupant P1, and a force acts on the airbag 21 at a point separated above the first fixing section SP1. In contrast, in the far-side airbag device 19B of the second embodiment, the main protective section 26 is fastened by tethers 401 and 402, which suppresses rotation of the airbag 21 in an undesirable direction. This is because, assuming a virtual line of force vv derived from the line of force V1 and V2 of the force acting on the airbag 21 by the two tethers 401 and 402, the force due to tethers 401 and 402 acts in the range LL from the first fixing section SP1 to the second fixing section SP2, as shown in Figure 10. Moreover, the virtual line of force vv is approximately perpendicular to the line segment (not shown) connecting the first fixing section SP1 and the second fixing section SP2. Therefore, the rotation of airbag 21 is sufficiently suppressed.

[0035] In the far-side airbag device 19B of the second embodiment, the fastening portions CP1 and CP2 at one end of the tethers 401 and 402 and the main protective portion 26 are positioned at the position furthest from the fixing portion 28 on the seat back 17 side, or at a position that wraps around to the rear side from the furthest position, so as in the first embodiment, the rotation of the airbag 21 can be further suppressed.

[0036] C. Third Embodiment: Next, the configuration of the far-side airbag device 19C of the third embodiment will be described. The far-side airbag device 19C of the third embodiment is the same as the first and second embodiments in terms of its mounting position in the vehicle 10 and the mechanism by which the control device 24 operates the inflator 22, but the configuration of the tether attached to the airbag 21 is different.

[0037] The far-side airbag device 19C of the third embodiment, as shown in Figure 11, uses two thin tethers 441 and 442, similar to the second embodiment. Unlike the tethers 401 and 402 of the second embodiment, which were arranged parallel to each other, the two tethers 441 and 442 are arranged to intersect. One end 451 of tether 441 and one end 452 of tether 442 are fastened at a position away from the first and second fixing parts SP1 and SP2 of the airbag 21, but their positions in the Z direction are reversed compared to the second embodiment. The other ends 471 and 472 of tethers 441 and 442 are fastened to the side edge of the seat back 17, similar to the second embodiment. The locations where one end 451 and 452 of tethers 441 and 442 are fastened to the main protective part 26 are called one-end fastening parts CP1 and CP2. The other ends 471 and 472 of the tethers 441 and 442 are fastened to the side edge of the seat back 17, below the first fixing part SP1 of the airbag 21 and above the second fixing part SP2. The points where they are fastened to the seat back 17 are called the other end fastening parts AP1 and AP2.

[0038] In the third embodiment, as in the first embodiment, when a collision occurs on the far side of the occupant P1, the main protective section 26 is pushed toward the side wall section 11 by the occupant P1, and a force acts on the airbag 21 at a point separated above the first fixing section SP1. In contrast, in the far-side airbag device 19C of the third embodiment, the main protective section 26 is fastened by tethers 441 and 442, which suppresses rotation of the airbag 21 in an undesirable direction. This is because, assuming a virtual line of force vv derived from the line of force V1 and V2 of the force acting on the airbag 21 by the two intersecting tethers 441 and 442, the force due to the tethers 441 and 442 acts in the range LL from the first fixing section SP1 to the second fixing section SP2, as shown in Figure 11. Furthermore, although the line of force V1 from tether 441 and the line of force V2 from tether 442 intersect, the virtual line of force vv is approximately perpendicular to the line segment (not shown) connecting the first fixed part SP1 and the second fixed part SP2. Therefore, the rotation of the airbag 21 is sufficiently suppressed.

[0039] In the far-side airbag device 19C of the third embodiment, the fastening portions CP1 and CP2 between the tethers 441 and 442 and the main protective portion 26 are positioned at the furthest point from the fixing portion 28 on the seat back 17 side, or at a position that wraps around to the rear side from the furthest point, similar to the first and second embodiments.

[0040] D. Fourth Embodiment: Next, the configuration of the far-side airbag device 19D of the fourth embodiment will be described. The mounting position of the far-side airbag device 19D in the vehicle 10, the mechanism of operation of the inflator 22 by the control device 24, and the configuration using two tethers are the same as in the second and third embodiments. The far-side airbag device 19D of the fourth embodiment differs from the second and third embodiments in the configuration of attaching the tether to the airbag 21.

[0041] The far-side airbag device 19D of the fourth embodiment uses two thin tethers 501 and 502, as shown in Figure 12. However, it differs from the second embodiment in that the two tethers 501 and 502 are not parallel, and from the third embodiment in that they do not intersect. In the fourth embodiment, one end 511 and 512 of the two tethers 501 and 502 are fastened at a position separated from the first and second fixing parts SP1 and SP2 of the airbag 21, while the other ends 531 and 532 of the tethers 501 and 502 are fastened to the side edge of the seat back 17. As in the other embodiments, the locations where the tethers 501 and 502 are fastened to the main protective part 26 are called one-end fastening parts CP1 and CP2. The end fastening portions CP1 and CP2 to which the ends 511 and 512 of the tethers 501 and 502 are fastened are located in the inflated main protective portion 26 at the position furthest from the fixing portion 28 on the seat back 17 side, or at a position that wraps around to the back side from the furthest position. In addition, in the Z direction, the end fastening portion CP1 is located above the first fixing portion SP1 of the airbag 21, and the end fastening portion CP2 is located below the second fixing portion SP2.

[0042] On the other hand, the other ends 531 and 532 of the tethers 501 and 502 are fastened to the side edge of the seat back 17, below the first fixing part SP1 of the airbag 21 and above the second fixing part SP2. The points where they are fastened to the seat back 17 are called the other end fastening parts AP1 and AP2. As with other embodiments, the tethers 501 and 502 may be fastened by rivets, sewing, or by adhesive or welding.

[0043] In the fourth embodiment, as in the first embodiment, when a collision occurs on the far side of the occupant P1, the main protective section 26 is pushed toward the side wall section 11 by the occupant P1, and a force acts on the airbag 21 at a point separated above the first fixing section SP1. In contrast, in the far-side airbag device 19D of the fourth embodiment, the main protective section 26 is fastened by tethers 501 and 502, which suppresses rotation of the airbag 21 in an undesirable direction. This is because, assuming a virtual line of force vv derived from the line of force V1 and V2 of the force acting on the airbag 21 by the two non-parallel tethers 501 and 502, the force due to the tethers 501 and 502 acts in the range LL from the first fixing section SP1 to the second fixing section SP2, as shown in Figure 12. Furthermore, although the lines of force V1 from tether 501 and the lines of force V2 from tether 502 are non-parallel, the virtual line of force vv is approximately perpendicular to the line segment (not shown) connecting the first fixed part SP1 and the second fixed part SP2. Therefore, the rotation of the airbag 21 is sufficiently suppressed.

[0044] Furthermore, in the far-side airbag device 19D of the fourth embodiment, the fastening portions CP1 and CP2 at one end of the tethers 501 and 502 and the main protective portion 26 are positioned at the position furthest from the fixing portion 28 on the seat back 17 side, or at a position that wraps around to the rear side from the furthest position, so as with the other embodiments, the rotation of the airbag 21 can be further suppressed.

[0045] Although the above embodiments were described using a far-side airbag system 19, etc., as an example to protect an occupant P1 seated in the driver's seat body 13 of a left-hand drive vehicle 10, the same applies to right-hand drive vehicles and to an occupant P2 seated in the passenger seat body 14.

[0046] E. Other embodiments: (1) Another embodiment is an airbag device attached to the seat back of a vehicle seat. This airbag device comprises an airbag that is inflated from a folded state by the supply of inflation gas and has at least two fixing points fixed to the side edge of the seat back, and a tether that has one end fastened away from the fixing points of the airbag and the other end fastened to the side edge of the seat back. Here, the fastening position of the one end and the other end of the tether is such that the point of force application and the point of application of the force that acts on the airbag by the tether when the airbag inflates are below the first fixing point, which is the uppermost fixing point in the vertical direction of the seat back, and above the second fixing point, which is the lowest fixing point.

[0047] Such airbag systems include far-side airbags, far-center airbags, and side airbags, which protect occupants in the event of a collision on the far side (the side furthest from the occupant). Regardless of the name of the airbag system, it can be implemented as an airbag that is attached to the seat back and whose behavior is controlled by a tether. The seats to which the airbag system is attached can be of any type, including semi-packet seats, full-packet seats, and comfort seats. The vehicles can be any type of vehicle, not limited to multi-wheeled passenger cars with three or more wheels, but also including trucks, buses, and tractors. The vehicles can be any type of vehicle, not limited to those that can move under their own power, but also including towed vehicles. The seats in which occupants sit are not limited to the driver's seat where the driver and other occupants sit, but can also include the passenger seat and rear seats.

[0048] (2) In the configuration of (1) above, the fastening position between one end of the tether and the other end may further be such that the line segment connecting the point of force application and the point of application is approximately perpendicular to the line segment connecting the first fixing part and the second fixing part. Approximately perpendicular means ±10 degrees from perpendicular (90 degrees), that is, in the range of 80 degrees to 100 degrees. Even outside this range, if the fastening position between one end of the tether and the other end satisfies the conditions of (1) above, the rotation of the airbag will be suppressed, but if the line segment connecting the point of force application and the point of application is approximately perpendicular to the line segment connecting the first fixing part and the second fixing part, the rotation of the airbag will be further suppressed.

[0049] (3) In the configuration of (1) above, the tether is a single wide tether having a width approximately equal to the distance from the first fixing part to the second fixing part, and the position where one end of the wide tether is fastened to the airbag is below the first fixing part and above the second fixing part, and the position where the other end of the wide tether is fastened to the side edge of the seat back is below the first fixing part and above the second fixing part. This allows for a single tether and simplifies the configuration. Approximately equal width means a range of up to ±20% of the distance from the first fixing part to the second fixing part. Even if the width of the tether is outside this range, if the fastening position of one end of the tether to the other end satisfies the conditions of (1) above, the rotation of the airbag will be suppressed, but if the tether is a single wide tether having a width approximately equal to the distance from the first fixing part to the second fixing part, the rotation of the airbag will be suppressed even further. Furthermore, the width of the wide tether may be constant throughout its entire length, or it may not be constant, with some sections being wider and others narrower.

[0050] (4) In the configuration of (1) above, the tether may consist of multiple tethers, each having one end and the other end. This allows for greater flexibility in the position and combination of tethers to be attached. It is easier to realize a configuration that suits the shape of the airbag. The number of tethers may be two, three, or more. If the attachment direction of the multiple tethers is aligned from the first fixing part SP1 to the second fixing part SP2, it is easier to restrict the rotation of the airbag. When multiple tethers are arranged in parallel, the multiple tethers may be arranged adjacent to each other, spaced apart, or partially overlapping.

[0051] (5) In the above configuration, the multiple tethers may be arranged in parallel or intersecting, and the point of force application and the point of application of the force acting on the airbag may be the point of force application and the point of application of the force applied by each of the multiple tethers being combined. This makes it easier to restrict the rotation of the airbag. When multiple tethers are arranged in intersecting directions, the tethers may be fastened together at the point of intersection or not. When there are three or more tethers, some of the tethers may be arranged to intersect and the rest not to intersect, or all of the tethers may be arranged to intersect. When there are three or more tethers, one tether may intersect with another tether, or with two or more other tethers.

[0052] (6) In the above configuration, the position where one end of each of the multiple tethers is fastened to the airbag may be below the first fixing point and above the second fixing point, and the position where the other end of each of the multiple tethers is fastened to the side edge of the seat back may be below the first fixing point and above the second fixing point. In this way, the multiple tethers make the point of force application and the point of force acting on the airbag when the airbag inflates located below the first fixing point, which is the highest fixing point in the vertical direction of the seat back, and above the second fixing point, which is the lowest fixing point. As a result, it is possible to suppress the generation of an undesirable axis of rotation in the inflated airbag, and consequently, the rotation of the airbag can be suppressed.

[0053] (7) In the configurations of (1) to (6) above, one end of the tether may be fastened to the inflated airbag at the position furthest from the fixing point in the direction from the point of force application to the point of application, or at a position beyond that point along the surface of the airbag. This allows the tether to receive a large force against the movement of the airbag, further suppressing the rotation of the airbag.

[0054] (8) Another embodiment is a method of attaching an airbag to the seat back of a vehicle seat. This method is as shown in Figure 13, [1] Step T1, which involves fixing the airbag to the side edge of the seat back by at least two fixing points. [2] Step T2, adjusting the fastening position of one end of the tether to the other end such that the point of force application and the point of application of the force that acts on the airbag by the tether when the airbag inflates are below the first fixing part, which is the uppermost fixing part in the vertical direction of the seat back, and above the second fixing part, which is the lowest fixing part. [3] Step T3 involves fastening one end of the tether to a location away from the airbag mounting point, and fastening the other end of the tether to the side edge of the seatback. The method comprises the following: Here, process T2 may be incorporated into process T3. Such methods can be implemented in the various vehicles and their seats described above. This mounting method may be used when manufacturing vehicles such as cars, or when installing airbags in vehicles or their seats that have already been manufactured or sold.

[0055] (9) Another embodiment is a vehicle seat. This vehicle seat comprises a seat body on which an occupant can sit, an inflator that generates gas when a collision in the vehicle is detected or predicted, an airbag that has at least two fixing points fixed to the side edge of the seat back of the seat body and inflates and deploys from a folded storage state upon receiving gas from the inflator, and a tether with one end fastened to a position away from the fixing points of the airbag and the other end fastened to the side edge of the seat back. In this vehicle seat, the fastening position of one end and the other end of the tether is such that the point of force application and the point of application of the force that acts on the airbag by the tether when the airbag inflates are below the first fixing point, which is the highest fixing point in the vertical direction of the seat back, and above the second fixing point, which is the lowest fixing point. Such vehicle seats (seats) can be of any type, such as semi-packet seats, full-packet seats, or comfort type. Vehicle seats are not limited to seats installed in multi-wheeled passenger cars with three or more wheels; they can also be used as seats in trucks, buses, tractors, and other vehicles. They can be used in vehicles capable of self-propulsion, as well as in towed vehicles. They are not limited to driver's seats where the driver or other occupants sit; they can also be used as passenger seats, rear seats, and other similar positions.

[0056] (10) In each of the above embodiments, some of the configurations implemented by hardware may be replaced with software. At least some of the configurations implemented by software can also be implemented by discrete circuit configurations. Furthermore, if some or all of the functions of this disclosure are implemented by software, the software (computer program) may be provided in the form of being stored on a computer-readable recording medium. "Computer-readable recording medium" is not limited to portable recording media such as flexible disks and CD-ROMs, but also includes various internal storage devices in a computer such as RAM and ROM, and external storage devices fixed to a computer such as hard disks. In other words, "computer-readable recording medium" has a broad meaning that includes any recording medium on which data packets can be fixed rather than temporary.

[0057] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]

[0058] 10...Vehicle, 11...Side wall, 12...Side wall, 13,14...Seat body, 15...Steering wheel, 16...Seat cushion, 17...Seat back, 17a...Surface, 18...Headrest, 19,19B~19D...Far side airbag device, 20...Frame, 21...Airbag, 22...Inflator, 23...Retainer, 24...Control device, 25...Impact sensor, 26...Main protective part, 27...Sub protective part, 28...Fixing part, 30...Bolt, 31...Nut, 4 0, 40R, 401, 402, 441, 442, 501, 502… Tether, 41, 41a, 411, 412, 451, 452, 511, 512… One end, 43, 431, 432, 471, 472, 531, 532… Other end, AP, AP1, AP2… Other end fastening part, ap… Point of force, AX… Axis, CP, CP1, CP2… One end fastening part, cp… Point of application, P1, P2… Occupant, SP1… First fixing part, SP2… Second fixing part, T… Head, vv… Virtual force line

Claims

1. An airbag device that is attached to the seat back of a vehicle seat, An airbag having at least two fixing points that are fixed to the side edge of the seat back, which is inflated by supplying inflation gas from a folded state, A tether is fastened with one end to a position separated from the fixing portion of the airbag and the other end to the side edge of the seatback, Equipped with, An airbag device in which the fastening position of the one end and the other end of the tether is such that the point of force application and the point of application of the force that acts on the airbag by the tether when the airbag inflates are located below the first fixing part, which is the uppermost fixing part in the vertical direction of the seat back, and above the second fixing part, which is the lowest fixing part.

2. The airbag device according to claim 1, wherein the fastening position between the one end and the other end of the tether is further such that the line segment connecting the point of force application and the point of application is substantially perpendicular to the line segment connecting the first fixing part and the second fixing part.

3. The tether is a single wide tether having a width approximately equal to the distance from the first fixing part to the second fixing part. The position at which one end of the wide tether is fastened to the airbag is below the first fixing portion and above the second fixing portion. The position where the other end of the wide tether is fastened to the side edge of the seat back is below the first fastening portion and above the second fastening portion. The airbag device according to claim 1.

4. The airbag device according to claim 1, wherein the tether is composed of a plurality of tethers, each having one end and the other end.

5. The aforementioned multiple tethers are arranged in parallel or intersecting directions. The point of force application and the point of application of the force acting on the airbag are the point of force application and the point of application of the force applied by each of the plurality of tethers, respectively. The airbag device according to claim 4.

6. The position where one end of each of the plurality of tethers is fastened to the airbag is below the first fixing part and above the second fixing part, and The position where the other end of each of the plurality of tethers is fastened to the side edge of the seat back is below the first fixing part and above the second fixing part. The airbag device according to claim 4.

7. The airbag device according to any one of claims 1 to 6, wherein one end of the tether is fastened in the inflated airbag at a position furthest from the fixing portion in the direction from the point of force to the point of application, or at a position beyond that position along the surface of the airbag.

8. A method for installing an airbag in the seatback of a vehicle seat, The airbag is fixed to the side edge of the seatback by at least two fixing points. One end of the tether is fastened to a position separated from the fixing portion of the airbag, and the other end of the tether is fastened to the side edge of the seatback. When fastening the tether, the fastening position between the one end and the other end of the tether is such that the point of force application and the point of application of the force that acts on the airbag by the tether when the airbag inflates are below the first fixing part, which is the uppermost fixing part in the vertical direction of the seat back, and above the second fixing part, which is the lowest fixing part. How to install an airbag.

9. A seat body in which a passenger can sit, An inflator that generates gas when a collision in a vehicle is detected or predicted, The airbag has at least two fixing points that are fixed to the side edge of the seat back of the seat body, and inflates and deploys from a folded storage state upon receiving gas supply from the inflator, A tether is fastened with one end to a position separated from the fixing portion of the airbag and the other end to the side edge of the seatback, Equipped with, The fastening position between the one end and the other end of the tether is such that the point of force application and the point of application of the force exerted on the airbag by the tether when the airbag inflates are located below the first fixing part, which is the uppermost fixing part in the vertical direction of the seatback, and above the second fixing part, which is the lowest fixing part. Vehicle seats.

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