JP6918040B2 - Airbag device - Google Patents

Description

The present invention relates to an airbag device that protects an occupant in a passenger seat of a vehicle.

It is well known that vehicles are equipped with one or more airbags to protect occupants in the event of a vehicle accident. Airbags are, for example, so-called driver airbags that inflate from near the center of the steering wheel of an automobile to protect the driver, and passenger airbags that inflate from the instrument panel to protect passengers in the passenger seat. Also, on the side of the seat to protect the occupants in the event of a lateral impact, rollover, or overturn accident of the vehicle by deploying downward inside the window of the automobile. There are various forms such as side airbags to be deployed. The present invention relates to an airbag device for a passenger seat.

By the way, in the case of a so-called oblique collision in which an impact is applied to the vehicle from diagonally forward, the occupant may enter the deployed airbag at an irregular angle and the occupant's head may rotate. Since the injury value tends to increase when the head rotates, a structure that suppresses the rotation of the occupant's head has been proposed.

For example, the airbag device described in Patent Document 1 below suppresses the rotation of the occupant's head by providing bulging portions on the left and right sides of the airbag on the occupant's side. However, the device described in Patent Document 1 may not be able to sufficiently suppress the rotation of the occupant's head.

Japanese Unexamined Patent Publication No. 2013-14176

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an airbag device capable of effectively suppressing the rotation of the head of an occupant in the passenger seat of a vehicle. ..

Specifically, one of the objects of the present invention is to provide an airbag device including an airbag in which the tension of the surfaces facing the occupants can be adjusted.

Hereinafter, means for solving the above problems will be described. In the specification, claims and drawings of the present application, "front" means the front (direction of travel) of the vehicle, and "rear" means the rear of the vehicle. (The side opposite to the direction of travel), "right" means the right side in the direction of travel, "left" means the left side in the direction of travel, and "vehicle width direction" means the left-right direction.

In order to solve the above problems, the present invention is an airbag device that is housed in an instrument panel of a vehicle and protects a passenger in a passenger seat, and is an inflator that generates an expansion gas; and a gas released from the inflator. It is equipped with an airbag that expands and expands toward the occupant side. The airbag has a front protection portion located in front of the occupant when deployed; and a pair of side protrusions located on the vehicle width direction side portion of the front protection portion and protruding toward the occupant side from the front protection portion. Has. Inside the airbag, a central tether having a front end connected to the vicinity of the front of the airbag and a rear end connected to the front protective portion; a pair of left and right provided so as to branch from the central tether. A branch tether is provided. Here, the front end portion of the branch tether is connected by the branch portion of the intermediate portion in the longitudinal direction of the central tether, and the rear end portion is connected to the front protection portion. Then, when the airbag is fully deployed, the rear side of the central tether from the branch portion is slackened.

As described above, when arranging a plurality of tethers extending in the deployment direction of the airbag, by providing a branch tether branched from one central tether, not only the manufacturing process can be simplified but also the mounting accuracy can be achieved. There is a merit that the variation of is reduced.

Further, when the airbag is fully deployed, the rear side of the central tether, that is, the occupant side is in a slackened state, so that the front protective portion is not pulled forward by the central tether. As a result, the radius of curvature of the front protection portion of the fully deployed airbag becomes large (close to flat), and it becomes possible to receive the occupant in a wide range.

In addition, "a state in which the rear side of the central tether is loosened from the branch portion" means that the front protective portion is not pulled forward (tether side) at the connecting portion with the central tether to form a recess. It means a state having a low degree of tension.

It is preferable that the front protection portion is pulled forward by the central tether when an occupant enters the airbag from an oblique direction.
If an occupant enters the fully deployed airbag from an oblique direction, the branch tether that receives pressure will loosen, but on the other hand, tension will be applied to the central tether, and the central tether will move the front protection part forward. Pulled by. As a result, when viewed from the occupant side, the connecting portion with the central tether on the front protective portion is in a recessed state, and the radius of curvature of the front protective portion in the portion becomes small, so that the occupant's head can be flexibly received. It becomes possible.

By making the length of the rear portion of the central tether from the branch portion longer than the total length of the branch tether, the radius of curvature of the front protection portion, that is, the tension can be set to an appropriate level while having a simple structure. It becomes.

The front end of the central tether can be connected around the inflator. For example, the front end portion of the central tether can be connected to a fixed portion such as a housing accommodating an inflator.

The front end portion of the branch tether can be connected to a position near the center in the longitudinal direction of the central tether, in front of or behind the center. By adjusting the connection position of the branch tether with respect to the central tether, the radius of curvature of the front protection portion, that is, the tension can be adjusted.

The rear end portion of the central tether can be connected near the center of the front surface protection portion.

On the front protection portion, the connecting portion with the central tether and the connecting portion with the pair of branch tethers can be arranged so as to be displaced in the vertical direction. For example, it is preferable that the connecting portion with the central tether is arranged so as to be displaced upward from the connecting portion with the pair of branch tethers.

When the occupant's head enters the front protection portion from an oblique direction, the heavy head usually moves downward (diagonally downward). Therefore, if the first front-rear tether located on the outside is displaced downward, the branch tether below the central tether when the occupant's head slides from the central protrusion and slides toward the lateral protrusion. It is possible to reliably and flexibly receive the occupant's head at the protruding portion (the portion having a small radius of curvature) formed by the above.

The central tether and / or the branch tether can be formed into a tapered strip shape in which the width increases from the front end portion to the rear end portion. By widening the width of the rear end side (connecting part with the front protection part) of each tether, the deployment shape and deployment posture of the airbag can be reliably controlled, and the tension adjustment range of the front protection part should be widened. Therefore, the effectiveness of the tension adjustment function due to the change in the radius of curvature can be enhanced.

FIG. 1 is a side view showing a deployed state of the passenger seat airbag device according to the present invention. FIG. 2 is a schematic view showing the configuration of the panel and the tether constituting the airbag corresponding to the cross section in the AA direction of FIG. 1, and for convenience, the connecting portion between the panel and the tether is shown separately. FIG. 3 is a schematic view showing the dimensions, shape, position of the connecting portion, and the like of the panel and the tether constituting the airbag, corresponding to the cross section in the AA direction of FIG. 1 as in FIG. FIG. 4 is a front view showing a deployed state of the passenger seat airbag device according to the present invention, and shows a state seen from the occupant side. FIG. 5 is a plan view showing the shape of a panel constituting the airbag according to the present invention, in which (A) and (B) are side panels and (C) is a front panel. 6 (A) and 6 (B) are plan views showing a part of the front panel constituting the airbag according to the present invention, and show the connection position with each tether. FIG. 7 is a plan view showing the shape of the tether constituting the airbag according to the present invention and the connection position between the front panel and the tether. FIG. 8 is a schematic view showing a deployed state of the passenger seat airbag device according to the present invention, and corresponds to a cross section in the AA direction of FIG. In FIG. 8, (A) shows the initial stage of deployment, and (B) shows the deployment of the airbag when the occupant enters the airbag from an oblique direction (oblique direction) after the state of (A). Shows (deformation) behavior.

Hereinafter, the passenger seat airbag device according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the occupant P is based on the experimental dummy, but the actual occupant also functions in the same manner.

FIG. 1 is a side view showing a deployed state of the airbag 14 of the passenger seat airbag device according to the present embodiment. FIG. 2 is a schematic view showing the configuration of the tether constituting the airbag 14 corresponding to the cross section in the AA direction of FIG. 1, and the connecting portions of the tether are shown apart in order to clearly distinguish each member. ing. FIG. 3 is a schematic view showing the dimensions, shape, position of the connecting portion, and the like of the panel and the tether constituting the airbag 14, corresponding to the cross section in the AA direction of FIG. 1 as in FIG. In FIG. 3, the white circle indicates the sewn portion (connecting portion). FIG. 4 is a front view showing the deployed state of the airbag 14, and shows a state seen from the occupant side.

As shown in FIG. 1, the airbag device according to the present embodiment is housed in the instrument panel 10 of the vehicle and protects the passenger P in the passenger seat, and the inflator 12 and the inflator 12 that generate expansion gas. It is provided with an airbag 14 that expands and expands toward the occupant P side by the gas released from the occupant P.

The airbag 14 is located on the front protection portion 16 located in front of the occupant P when deployed, and on the vehicle width direction side portion of the front protection portion 16, and is a pair of sides protruding toward the occupant P side from the front protection portion 16. It is provided with direction protrusions 18L and 18R (see FIG. 2).

Inside the airbag 14, a central tether 20 having a front end connected to the vicinity of the front of the airbag and a rear end connected to a front protective portion 16; left and right provided so as to branch off from the central tether 20. A pair of branch tethers 22R and 22L are provided. Here, the front end portion of the central tether 20 can be connected to the periphery of the inflator 12. For example, the front end portion of the central tether 20 can be connected to a fixed portion such as a housing accommodating the inflator 12 (see FIG. 1).

The front end portions of the branch tethers 22L and 22R are connected by the branch portion 21 of the intermediate portion in the longitudinal direction of the central tether 20, and the rear end portion is connected to the front protection portion 16. Then, when the airbag 14 is fully deployed, the rear side 20a of the central tether 20 is configured to be in a loosened state.

5A and 5B are plan views showing the shapes of the panels constituting the airbag 14 according to the present embodiment, in which the side panels 50R and 50L are shown in (A) and (B) and the front panel 54 is shown in (C). 6 (A) and 6 (B) are plan views showing a part of the front panel 54, and show the connection positions with the tethers 20, 22R, and 22L.

As shown in FIG. 5, the airbag 14 according to this embodiment is formed from two side panels 50L and 50R and one center panel 54. The side panels 50L and 50R are panels having the same shape located on both the left and right sides when viewed from the occupant P side, and include arc-shaped curved portions 52L and 52R forming the lateral protrusions 18L and 18R. On the other hand, the front panel 54 includes an elliptical or substantially circular region (58L, 58R) forming the front protective portion 16 of the airbag 14 and a strip-shaped region 60. Then, the arcuate curved portions 58L, 58R of the front panel 54 and the curved portions 52L, 52R of the side panels 50L, 50R are connected by sewing, and the other edge portions of the side panels 50L, 50R are connected to the strip-shaped region of the front panel 54. The airbag 14 is formed by connecting to both edges of the 60 by sewing.

As shown in FIG. 6A, the connecting portion (sewing position) of the central tether 20 to the front protective portion 16 of the front panel 54 is 64, and is located near the center of the front protective portion 16. Further, the connecting portions (sewing points) with the branch tethers 22L and 22R are 62L and 62R. In this example, all the connecting portions 62L, 62R, 64L are arranged in parallel and symmetrically, but even if they are not completely parallel, it seems that either the top or bottom is open like a "C" character. It is also possible to arrange and shape in various ways.

The characteristic feature of the example shown in FIG. 6 (A) is that the connecting portion 64 with the central tether 20 is displaced downward from the connecting portions 62L and 62R with the branch tethers 22L and 22R on the front protection portion 16. To be placed.

As a variation different from FIG. 6A, as shown in FIG. 6B, the connecting portions 64, 62R, 62L of the tethers 20, 22R, 22L on the front protection portion 16 have the same height in the vertical direction. It can also be placed in.

FIG. 7 is a plan view showing the shapes of the tethers 20, 22R and 22L and the connecting positions of the front panel 54 and the tethers 20, 22R and 22L. The central tether 20 and the branched tethers 22L and 22R are formed in a tapered band shape in which the width increases from the front end portion to the rear end portion.

In FIG. 7, the portion (62L, 62R, 64, 66, 72, 74, 76, 80) indicated by the broken line rectangle indicates the region connected by sewing. In addition, the parts that are sewn and connected to each other are connected by thin lines. For convenience of explanation, only one branch tether (22R, 22L) is shown, but there are actually two.

As shown in FIG. 7, the effective length L2 of the portion rearward from the branch portion 21 of the central tether 20 is longer than the total length L3 of the branch tethers 22L and 22R. Further, the branch portion 21 of the central tether 20 is slightly displaced rearward from the center in the longitudinal direction of the central tether 20, and has an effective length L1> L2. Regarding the relationship between the lengths L1 and L2, L1 = L2 or L1 <L2 can be set. By adjusting the connection positions 78 (21) of the branch tethers 22L and 22R with respect to the central tether 20 in this way, the radius of curvature of the front protection portion 16, that is, the tension can be adjusted.

(Operation of the embodiment)
Hereinafter, the overall operation of the embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic view showing a deployed state of the passenger seat airbag device according to the present invention, and corresponds to a cross section in the AA direction of FIG. In FIG. 8, (A) shows the initial stage of deployment, and (B) shows the airbag when the occupant enters the airbag from an oblique direction (oblique direction) after the state of (A). The unfolding (deformation) behavior of 14 is shown.

When the airbag 14 is deployed due to a vehicle collision, in the initial stage, as shown in FIG. 8A, the expansion gas applies tension to the branch tethers 22L and 22R in the front-rear direction (deployment direction), and these branch tethers 22L. , The front protection portion 16 is attracted to the front of the vehicle (on the inflator 21 side) at the connecting portion with the 22R.

As shown in FIG. 8A, when the airbag 14 is fully deployed, the rear side of the central tether 20 from the branch portion 21, that is, the occupant P side is in a slackened state. Therefore, the front protection portion 16 is not pulled forward by the central tether 20. As a result, the radius of curvature of the front protective portion 16 of the fully deployed airbag 14 becomes large (close to flat), and the occupant P can be received in a wide range.

In addition, "a state in which the rear side of the central tether 20 is loosened from the branch portion 21" means that the front protective portion 16 is pulled forward (tether side) at the connecting portion with the central tether 20 to form a recess. It means a state having a low tension to the extent that there is no such thing.

After that, as shown in FIG. 8B, for example, when the occupant P enters the fully deployed airbag 14 diagonally forward to the left, the branch on the side that receives pressure from the head of the occupant P. The tension of the tether 22L decreases and the tether 22L becomes loose. At this time, tension is applied to the central tether 20 as the front protection portion 16 moves, and the central tether 20 pulls the front protection portion 16 forward. As a result, when viewed from the occupant P side, the connecting portion with the central tether 20 on the front protective portion 16 is in a recessed state, and a region 100 having a small radius of curvature is formed in the front protective portion 16. This makes it possible to flexibly receive the head of the occupant P and suppress the rotation of the head.

Note that FIG. 8B shows a case where the occupant P enters diagonally forward to the left, but it goes without saying that the same operation occurs when the occupant P enters diagonally forward to the right.

(Interpretation of the technical scope of the present invention)
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be appropriately modified within the scope of the technical idea expressed in the claims.

Claims (12)

An airbag device that is housed in the instrument panel of the vehicle and protects the passenger seat occupants.
With an inflator that generates expansion gas;
It is equipped with an airbag that expands and expands toward the occupant side by the gas released from the inflator.
The airbag has a front protection portion located in front of the occupant when deployed; and a pair of side protrusions located on the vehicle width direction side portion of the front protection portion and protruding toward the occupant side from the front protection portion. Have,
Inside the airbag, a central tether having a front end connected to the vicinity of the front of the airbag and a rear end connected to the front protective portion; a pair of left and right provided so as to branch from the central tether. Branch tether and is provided,
The front end portion of the branch tether is connected by the branch portion of the intermediate portion in the longitudinal direction of the central tether, and the rear end portion is connected to the front protection portion.
An airbag device characterized in that, when the airbag is fully deployed, the rear side of the central tether is slackened from the branch portion. The airbag device according to claim 1, wherein the front protection portion is pulled forward by the central tether when an occupant enters the airbag from an oblique direction. The airbag device according to claim 1 or 2, wherein the length of the portion rear of the branch portion of the central tether is longer than the total length of the branch tether. The airbag device according to any one of 1 to 3, wherein the front end portion of the central tether is connected to the periphery of the inflator. The airbag device according to any one of 1 to 4, wherein the front end portion of the branch tether is connected to the vicinity of the center in the longitudinal direction of the central tether. The airbag device according to any one of 1 to 4, wherein the front end portion of the branch tether is connected to a position in front of the center in the longitudinal direction of the central tether. The airbag device according to any one of 1 to 4, wherein the front end portion of the branch tether is connected to a position rearward of the center in the longitudinal direction of the central tether. The airbag device according to any one of 1 to 7, wherein the rear end portion of the central tether is connected to the vicinity of the center of the front protection portion. One of claims 1 to 8, wherein the connecting portion with the central tether and the connecting portion with the pair of branch tethers are arranged so as to be displaced in the vertical direction on the front protection portion. The airbag device described in. The airbag device according to claim 9, wherein the connecting portion with the central tether is arranged on the front protective portion so as to be displaced upward from the connecting portion with the pair of branch tethers. The airbag device according to any one of claims 1 to 10, wherein the central tether is formed in a tapered band shape in which the width increases from the front end portion to the rear end portion. The airbag device according to any one of 1 to 11, wherein the branch tether is formed in a tapered band shape in which the width increases from the front end portion to the rear end portion.

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