JP2001219807A - Structure of quarter window garnish portion of vehicle with curtain air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a quarter window garnish portion of a vehicle with a curtain air bag, ensuring development of the curtain air bag to the inside of a car interior without causing a member bent into the car interior during development of the air bag to hit a crew at his head, and offering good design. SOLUTION: This quarter window garnish portion 10 having a quarter window garnish 11 divided into a roof side portion 12 and a general portion 21 comprises an air bag device I arranged between a rear part 24 of he general portion and a quarter inner panel Pi and the curtain air bag A connected to the air bag device and arranged between the roof side portion and the quarter inner panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quarter wind garnish structure of a vehicle having a curtain airbag.

[0002]

2. Description of the Related Art Conventionally, airbags have been provided on the front and side surfaces of a vehicle cabin in order to safely protect an occupant of a vehicle such as an automobile from the impact of a collision. Among them, the curtain airbag provided to prevent the occupant's head from colliding with the side glass or the like in response to the impact from the side of the automobile is housed behind the front pillar garnish and behind the interior member on the roof side, and is mounted on the instrument panel. Gas generated from an airbag device such as an inflator provided in the vicinity inflates the curtain airbag and deploys the curtain airbag in the vehicle interior. Further, since the airbag device operates only at the time of high-speed collision, a rib-shaped energy absorber made of resin may be provided on the back side of the pillar garnish or the like in order to absorb the impact at the time of low-speed collision.

However, if an airbag device such as an inflator is provided near the instrument panel as described above, a great stress is applied to the front pillar garnish, and the garnish is made of a soft material or the like to withstand the stress. However, in this case, the rigidity of the garnish is lost, and there is a quality problem. In addition, when considering the repair (replacement) of the front pillar garnish after the curtain airbag is deployed due to an accident, if the airbag device is installed near the instrument panel, it is necessary to remove the instrument panel at the time of repair However, there is also a problem that the repair work becomes complicated.

In recent years, as shown in FIGS. 7 and 8, an airbag device (inflator) I has a quarter side glass Wq such as a roof side inner 100 at the rear of a vehicle compartment or a hatchback type (wagon type). In a vehicle, the quarter wind garnish 120 surrounding the quarter wind glass Wq has been arranged. As a result, the curtain airbag A housed in the front pillar garnish F is located at the deepest part when viewed from the airbag device I, so that the stress applied to the front pillar garnish F is reduced, and the front pillar garnish F Even when a relatively hard material was selected, the garnish F was less likely to be broken and scattered when the curtain airbag A was inflated. in addition,
Since there is no need to remove the instrument panel N during repair, the work efficiency of repair has increased. The roof side inner 100 may be referred to as a rear pillar garnish depending on the type of vehicle.

When the airbag device I for inflating the curtain airbag A is provided at the rear of the passenger compartment,
The curtain airbag A deploys downward from the ceiling member R as shown by the chain line in the drawing. Also,
When the curtain airbag A is inflated, a part of the front pillar garnish F, the ceiling member R, the roof side inner 100 or the quarter wind garnish 120 is pushed and bent toward the vehicle interior, and the curtain airbag is moved toward the vehicle interior. Deployment is possible. Further, conventionally, the quarter wind garnish 120 has a roof side portion (upper portion) 121, a lower portion 122, and a front portion 12.
3. The rear part 124 is formed of one resin in a series.

When the airbag device I is provided at the rear of the passenger compartment, as shown in FIG. 7, when the vehicle is a sedan type, the airbag device I and the curtain airbag A can be relatively easily mounted without any trouble. 100
Alternatively, it is known that the vehicle can be disposed on the back side of the ceiling member R. On the other hand, as shown in FIG. 8, a vehicle having a quarter wind glass Wq such as a hatchback type (wagon type) has the following disadvantages. I have.

That is, an airbag device I is disposed on the back side of the quarter wind garnish 120, and the curtain airbag A connected to the airbag device I is mounted on the back side of the ceiling member R (generally, the quarter wind garnish 12).
When the curtain airbag A is inflated, a lower tension acts on the curtain airbag A as shown in FIG. 9 showing a section 9-9 in FIG. The airbag A is composed of the quarter inner panel Pi and the quarter wind garnish 120 (the roof side part 1).
21), there is a possibility that the airbag A does not deploy properly into the vehicle interior. Reference numeral 13 in FIG.
Reference numeral 0 denotes a bracket provided on the surface of the quarter inner panel Pi for accommodating the folded curtain airbag, 131 denotes a locking member for fixing the bracket 130 to the quarter inner panel Pi, and 132 denotes a rib-shaped energy absorber. , M are occupants.

In order to prevent the curtain airbag from being poorly deployed, if the position of the curtain airbag A is moved toward the ceiling member (toward the interior of the vehicle) as shown in FIG. The bent ceiling member R may hit the head Ma of the occupant M. FIG.
As shown in FIG. 1, when the dividing line (boundary line) L between the ceiling member R and the quarter wind garnish 120 is lowered and the roof side portion 121 of the quarter wind garnish 120 is reduced, the quarter wind garnish 120
There is a disadvantage that the appearance as a window frame becomes poor.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been developed in consideration of the above circumstances. A member in which a curtain airbag is reliably deployed in a vehicle interior and a member bent into the vehicle interior when the airbag is deployed. The present invention provides a structure of a quarter wind garnish portion of a vehicle with a curtain airbag, which does not cause a problem such as hitting an occupant's head and has good design.

[0010]

The quarter wind garnish surrounding the quarter wind glass of the vehicle and attached to the quarter inner panel so as to cover the curtain airbag is characterized in that the quarter wind garnish is provided in the quarter wind garnish. The roof side portion is disposed on the ceiling member side end side so as to cover the upper side portion of the glass, and is divided into a general portion disposed so as to cover other three side portions other than the upper side portion of the quarter wind glass. The airbag device is disposed between the rear portion of the general portion and the quarter inner panel, and the curtain airbag connected to the airbag device is folded between the roof side portion and the quarter inner panel. The roof side portion is pushed by the inflation of the curtain airbag and bent toward the vehicle interior. Is, the curtain air bag according to the structure of the quarter window garnish portion of the curtain airbag with the vehicle, characterized in that it is configured to deploy to the vehicle interior side.

According to a second aspect of the present invention, in the first aspect, the folded curtain airbag is housed in a bracket which is provided on a quarter inner panel portion facing the back side of the roof side portion and which opens in the vehicle interior side. In addition, a fixing wall portion is provided upright on the ceiling member side on the back surface of the roof side portion, and the roof side portion is fixed to the bracket via the fixing wall portion.

According to a third aspect of the present invention, in the second aspect, a fixing claw portion bent outward is formed on the ceiling member side of the bracket, and the fixing claw portion is formed on a fixing wall portion of the roof side portion. Characterized in that it is configured to be inserted and hooked into the opening.

According to a fourth aspect of the present invention, in the third aspect, a positioning boss having a hole is formed on an outer wall surface of the bracket at the opening end on the ceiling member side, and a positioning boss having a hole is formed on the back side of the roof side portion on the ceiling member side. Is characterized in that a positioning claw portion which can be inserted into a hole of the positioning boss is formed in addition to the fixing wall portion.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a fixing rib is provided upright on a back surface of the general portion of the quarter wind garnish near a boundary with the roof side portion. The general portion is locked and fixed to the quarter inner panel through the intermediary portion.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic view showing a state of a vehicle interior having a quarter wind garnish portion according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a sectional view taken along line 3-3 of FIG. FIG. 4 is a sectional view showing a main part of a quarter wind garnish portion according to another embodiment, FIG. 5 is a perspective view showing a roof side portion and an airbag accommodating bracket of the quarter wind garnish of the embodiment, and FIG. 5
FIG. 4 is an enlarged cross-sectional view showing a state of a main part when the roof side portion of the quarter wind garnish and the airbag housing bracket are fixed.

A quarter wind garnish portion 10 according to one embodiment of the present invention is provided on a side surface of a rear portion of a vehicle C having a quarter wind glass Wq, such as a hatchback type (wagon type) shown in FIGS. Has been deployed. In the quarter wind garnish unit 10,
A quarter wind garnish 11 is attached to the quarter inner panel Pi so as to surround the quarter wind glass Wq and cover the curtain airbag A. In addition, the code | symbol R in a figure is a ceiling member, Po is a quarter outer panel.

The quarter wind garnish 11
Is a roof side portion 12 disposed on the side end of the ceiling member R so as to cover the upper side portion Wq1 of the quarter window glass Wq, and three other side portions Wq2 other than the upper side portion Wq1 of the quarter window glass Wq. , Wq3, and Wq4.

Between the roof side portion 12 and the quarter inner panel Pi, a curtain airbag A connected to an airbag device I described later is disposed in a folded state. In this embodiment, a bracket B having a substantially U-shaped cross section is provided in a portion of the quarter inner panel Pi facing the back side of the roof side portion 12 and opened in the vehicle interior side direction, and a curtain folded in the bracket B is provided. The airbag A is housed. Here, it is preferable to minimize the gap S between the general portion side opening end Ba of the bracket B and the general portion 21. Then, when the curtain airbag A described later is inflated, it becomes more difficult for the curtain airbag A to enter the back side of the general portion 21. In addition, the bracket B in the embodiment is not only on the back side of the roof side portion 12,
The curtain airbag A, which is located on the rear side of the ceiling member R and extends to the upper end position of the front pillar garnish F behind the ceiling member R, is also accommodated in the bracket B. In the embodiment, the front end A1 of the curtain airbag A is fixed at a substantially middle position of the front pillar garnish F.
Reference numeral k1 in the drawing denotes a locking member such as a bolt or a clip for fixing the bracket B to the quarter inner panel Pi.

Further, in this embodiment, the roof member side end 12a of the roof side portion 12 is
Of the ceiling member R
Is fixed to a side end Ra by a locking member (clip in the illustrated example) k2 such as a clip or a bolt. Here, the roof side portion 12 is preferably made of a resin having excellent impact resistance, such as a polyolefin-based thermoplastic elastomer (TPO). Then, it is possible to prevent the roof side portion 12 from being damaged by an impact due to the inflation of the curtain airbag A, and to prevent scattering.

The general portion 21 includes a front portion 22 covering the front side portion Wq2 of the quarter window glass Wq, a lower portion 23 covering the lower side portion Wq3 of the quarter window glass Wq, and a rear portion 24 covering the rear side portion Wq4 of the quarter window glass Wq. It is composed of In the embodiment, the components 22, 23, 2
4 is made of the same resin and is formed in a series.
The general portion 21 is preferably made of a resin having higher rigidity than the roof side portion 12, for example, a hard resin such as polypropylene. Then, the deformation due to the pressing from the vehicle interior side can be made hard to occur, and the workability of attaching the general part 21 can be improved. And
Rear part 24 of general part 21 and quarter inner panel P
Between i, an airbag device I such as an inflator and a base A2 of a curtain airbag A connected to the airbag device I are disposed obliquely forward.

Further, the general portion 21 of this embodiment is fixed to the quarter inner panel Pi of the vehicle body by a locking member k3 such as a clip or a bolt (clip in the figure).
In the embodiment, the fixing ribs 25 are provided near the boundaries between the front side 22 and the rear side 24 of the general part 21 and the roof side part 12.
And a locking member k3 is attached to the fixing rib 25, and the locking member k3 is fitted into a locking hole (not shown) formed in the quarter inner panel Pi, whereby a general portion is formed. 21 is fixed to the quarter inner panel Pi. When the general portion 21 is locked and fixed to the quarter inner panel Pi near the boundary with the roof side portion 12 in this way, the quarter inner panel Pi near the boundary is fixed.
And the general portion 21 can be prevented from coming off the quarter inner panel Pi near the boundary with the roof side portion 12 when the airbag is inflated. The opening of the bend becomes smooth. Of course, the general portion 21 may be fixed to the quarter inner panel Pi by a locking member such as a clip at another position.

Further, in this embodiment, the energy absorber is provided on both the rear side of the general portion 21 and / or the rear side of the ceiling member R, in the illustrated example, to absorb the impact at the time of low-speed collision. 26 are provided. Examples of the energy absorber 26 include a resin or rib-shaped or lattice-shaped energy absorber or foam.

The quarter wind garnish portion 10 having the above-described structure allows the gas to enter the curtain air bag A by the operation of an airbag device (inflator) I disposed at the rear portion 24 of the general portion 21 of the quarter wind garnish 11 at the time of a vehicle collision. The air bag A is inflated sequentially from the rear side of the general portion 21 by press-fitting. Then, due to the inflation of the curtain airbag A housed on the back side of the roof side portion 12, the roof side portion 12 is pushed and bent toward the vehicle interior as shown by a chain line in FIG. The curtain airbag A is deployed toward the vehicle interior from the gap between the side portion 12 and the general portion 21 or the quarter window glass Wq, and the portion of the airbag A accommodated on the back side of the ceiling member R and the back side of the front pillar garnish F is described. Due to the inflation, the ceiling member R and the front pillar garnish F are pushed and bent toward the interior of the vehicle, and the curtain airbag A is formed from the gap between the bent and bent ceiling member R and the front pillar garnish F and an inner panel (not shown). Deployed to the passenger compartment side, mainly occupants M
To protect the head Ma.

As described above, in the quarter wind garnish portion 10 disclosed herein, the quarter wind garnish 11 is divided into the roof side portion 12 and the general portion 21, and when the curtain air bag A is inflated, the air bag A The roof side portion 12 is pushed and bent, and the airbag A is reliably deployed in the vehicle cabin from the gap between the roof side portion 12 and the general portion 21 or the quarter window glass Wq. 9, the problem of poor deployment of the airbag A can be solved. In addition, since the fulcrum of the roof side portion 12 at the time of bending and opening is the ceiling member side end portion 12a (strictly speaking, a portion fixed to the ceiling member R), the range of the portion to be bent and opened is compared with the conventional case. As a result, the airbag A is correctly deployed downward. As a result, the head Ma of the occupant M is held by the roof side portion 12 that is bent and opened when the airbag is deployed.
The occurrence of troubles such as hitting can be avoided. Further, in the above structure, the dividing line (boundary) between the ceiling member R and the quarter wind garnish 11 does not need to be lowered, so that the appearance of the quarter wind garnish 11 as a window frame is good.

FIG. 4 shows the structure of a quarter wind garnish portion 10A according to another embodiment of the present invention. The quarter wind garnish unit 10
The configuration of A is substantially the same as the configuration of the quarter wind garnish section 10 of the above embodiment. In the drawing, the same members as those of the quarter wind garnish section 10 are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, portions different from the above embodiment will be described.

In the quarter wind garnish section 10A of this embodiment, the ceiling member R side (upper side) on the back side of the roof side section 12 of the quarter wind garnish 11.
An appropriate number (three in the example shown) of fixing wall portions 13 are erected on the roof side portion 12 via the fixing wall portion 13.
It is fixed to a bracket B for accommodating a curtain airbag A. In the illustrated example, the fixing wall portion 13 is integrally formed from the back surface of the roof side portion 12.

The structure for fixing the roof side portion 12 to the bracket B will be described in detail. As will be better understood from FIG.
On the side (upper side), fixing nails B1 bent outward at the ceiling member side opening end Bb in the drawing are formed in accordance with the position and number of the fixing wall portions 13 of the roof side portion 12, and An opening 14 for a claw portion is formed in the fixing wall portion 13, and as shown in FIG.
The fixing claw portion B of the bracket B is inserted into the claw portion opening portion 14 of FIG.
1, the roof side portion 12 is fixed to the bracket B by hooking. In this way, the workability of fixing the roof side portion 12 to the bracket B is extremely simple, and the connection between the roof side portion 12 and the bracket B is sufficient. Of course, the fixing of the fixing wall portion 13 of the roof side portion 12 to the bracket B is not limited to the above example.
Can be fixed to the outer wall of the bracket B by a locking member such as a bolt or a clip.

If the roof side portion 12 is fixed to the bracket portion B via the fixing wall portion 13 erected on the back side of the roof side portion 12 as described above, the roof side portion is inflated by the inflation of the curtain airbag A. The strength against a large amount of stress acting on the ceiling member side end portion 12b of the portion 12 becomes sufficient, and the roof side portion 12 can be prevented from scattering when the curtain airbag A is inflated. In addition, since there is no locking member such as a clip on the design side of the roof side portion 12, there is an advantage that the aesthetic appearance is excellent.

In this embodiment, as shown in FIG. 5, an appropriate number of positioning bosses B2 having holes B3 are provided on the outer wall surface of the opening end Bb on the ceiling member side of the bracket B (in FIG. 2) so as to be located between the fixing claw portions B1, and the roof side portion 12
On the back surface, in addition to the fixing wall portion 13, a positioning claw 15 that can be inserted into the hole B3 of the positioning boss B2 is formed. For this reason, when the roof side portion 12 is mounted, if the positioning claw portion 15 is inserted into the hole B3 of the positioning boss B2 of the bracket B as shown in FIG. The roof side portion 12 of the wind garnish 11 can be mounted at a correct position. In the illustrated example, the tip 16 of the positioning claw 15 has an enlarged shape. In this way, even after the positioning claw 15 is inserted into the hole B3 of the positioning boss B2, even if a force in the pullout direction is applied to the positioning claw 15, the distal end 16 of the enlarged shape is positioned. The boss B2 is caught by the periphery of the hole B3 on the side of the quarter inner panel of the quarter inner panel, so that the roof side portion 12 is more difficult to be scattered when the airbag A is inflated.

Further, in this embodiment, as shown in FIG. 4, a general side end 12b of the roof side portion 12 is provided.
However, it has a bifurcated shape so as to sandwich the upper end 21 a of the general part 21, and the general part side end 12 b is locked to the upper end 21 a of the general part 21. As a result, it is possible to prevent generation of abnormal noise and rattling during vibration of the vehicle.
Note that the forked shape of the roof side portion 12 at the general portion side end portion 12b must be set so as not to hinder the bending and opening of the roof side portion 12 when the airbag is inflated.

[0031]

As shown and described above, in the structure of the quarter wind garnish of the vehicle with the curtain airbag according to the present invention, the quarter wind garnish covers the upper side of the quarter wind glass and the quarter wind glass. The roof side portion is divided into a general portion covering the other three sides, and the roof side portion is inflated by a curtain airbag disposed in a state of being folded between the roof side portion and the quarter wind inner panel at the time of a vehicle collision. Since it can be pushed and bent to the interior of the car,
The curtain airbag can be reliably deployed toward the vehicle interior. In addition, since the range of the bent portion of the roof side portion is smaller than before, the curtain airbag is correctly deployed in the downward direction, and a member which is bent into the passenger compartment when the airbag is deployed is a member of the occupant's head. Inconvenience such as hitting the part is hard to occur. Furthermore, in the structure of the quarter wind garnish portion, it is not necessary to move the dividing line between the ceiling member and the quarter wind garnish downward,
It looks good as a quarter wind garnish window frame.

In addition, in the present invention, the quarter wind garnish only needs to be made of a soft resin having excellent impact resistance, such as a polyolefin thermoplastic elastomer, only in the roof side portion, and the other general portions are made of polypropylene or the like. Can be made of a hard resin having high rigidity. As a result, the rigidity of the quarter wind garnish as a whole is sufficient, the workability of assembling the quarter wind garnish is not deteriorated, and the curtain airbag and the airbag device can be easily assembled.

Further, the folded curtain airbag is housed in a bracket provided in a quarter inner panel portion facing the back side of the roof side portion, and the bracket is attached to the bracket by the bracket. If the part is fixed via the fixing wall part erected on the ceiling member side on the back surface, the strength against the stress received from the curtain airbag on the roof side part will be sufficient, and when the airbag is deployed. It is possible to prevent the roof side portion from scattering. In addition, since there is no locking member such as a clip on the design side of the roof side portion, the appearance is excellent. In particular, a fixing claw bent outwardly is formed on the ceiling member side of the bracket, and the fixing claw is inserted into an opening formed in the fixing wall of the roof side portion. If the roof side portion is hooked, the strength of the roof side portion against stress received from the curtain airbag can be further increased, and the roof side portion can be fixed to the bracket extremely easily. Further, if positioning means is formed on the roof side portion and the bracket as in the invention of claim 4, the roof side portion can be attached to a correct position very easily.

In addition, when the general portion of the quarter wind garnish is fixed to the quarter inner panel near the boundary with the roof side portion as in the invention of claim 5, it is possible to prevent the general problem when the airbag is inflated. Part can be prevented from coming off near the boundary with the roof side part,
As a result, the roof side portion is smoothly bent and opened to the vehicle interior side.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state of a vehicle interior having a quarter wind garnish portion according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a cross-sectional view illustrating a main part of a quarter wind garnish portion according to another embodiment.

FIG. 5 is a perspective view showing a roof side portion and an airbag accommodating bracket of the quarter wind garnish of the embodiment.

6 is an enlarged cross-sectional view showing a state of a main part when the roof side portion of the quarter wind garnish of FIG. 5 and a bracket for holding an airbag are fixed.

FIG. 7 is a schematic view showing an example of a state of a cabin of a conventional sedan type vehicle.

FIG. 8 is a schematic view showing an example of a state in a vehicle cabin of a conventional hatchback type vehicle having a quarter wind garnish portion.

9 is a sectional view taken along line 9-9 in FIG. 8;

FIG. 10 is a cross-sectional view showing a main part of a quarter wind garnish portion of another example in the related art.

FIG. 11 is a cross-sectional view showing a main part of a quarter wind garnish portion of still another example in the related art.

[Explanation of symbols]

 10, 10A Quarter wind garnish portion 11 Quarter wind garnish 12 Roof side portion 13 Roof side fixing wall portion 14 Roof side fixing wall portion claw opening portion 15 Roof side portion positioning claw portion 21 General Part 24 Rear part of general part 25 Fixing rib C Vehicle A Curtain airbag I Airbag device Wq Quarter window glass Pi Quarter inner panel B Bracket B1 Bracket fixing claw B2 Bracket positioning boss B3 Bracket positioning boss Hole

Claims (5)

[Claims] 1. A quarter wind garnish that surrounds a quarter wind glass of a vehicle and is attached to a quarter inner panel so as to cover a curtain airbag, so that an upper side of the quarter wind glass covers an upper side of the quarter wind glass. And a general part disposed so as to cover the other three sides other than the upper side of the quarter window glass, between the rear part of the general part and the quarter inner panel. An airbag device is disposed in the roof side portion, and a curtain airbag connected to the airbag device is disposed between the roof side portion and the quarter inner panel in a folded state. The roof side part is pushed and bent toward the vehicle interior, and the curtain airbag is deployed toward the vehicle interior. Structure quota window garnish portion of the curtain airbag with the vehicle, characterized by being configured to. 2. The folded curtain airbag is housed in a bracket which is provided in a quarter inner panel facing a back side of the roof side portion and which opens in a vehicle interior side direction, and a back surface of the roof side portion. The quarter of a vehicle with a curtain airbag according to claim 1, wherein a fixing wall portion is provided upright on the ceiling member side, and a roof side portion is fixed to the bracket via the fixing wall portion. Structure of wind garnish part. 3. A fixing claw portion bent outward on the ceiling member side of the bracket is formed, and the fixing claw portion is inserted into an opening formed in the fixing wall portion of the roof side portion and hooked. The structure of the quarter wind garnish portion of the vehicle with a curtain airbag according to claim 2, wherein 4. A positioning boss having a hole is formed on an outer wall surface of an opening end on a ceiling member side of the bracket, and the fixing member is provided on the ceiling member side on the back surface of the roof side in addition to the fixing wall. 4. A positioning claw that can be inserted into a hole of the positioning boss.
Structure of a quarter wind garnish part of a vehicle with a curtain airbag described in the above. 5. A fixing rib is erected on the back surface of the general portion of the quarter wind garnish near the boundary with the roof side portion, and the general portion is locked and fixed to the quarter inner panel via the fixing rib. The structure of a quarter wind garnish portion of a vehicle with a curtain airbag according to any one of claims 1 to 4, wherein: