JP2003191814A - Air bag cover structure for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To radially expand an air bag cover while suppressing a harmful effect by a design body even when the design body is disposed in the substantial center of the air bag cover. <P>SOLUTION: The air bag cover 3 comprises the design body 4 disposed in the substantially central part, a first break line 5 formed so as to extend laterally on both sides of the design body 4 and face to the outer periphery of the design body near the design body, a pair of second break lines 6 formed so as to extend substantially vertically to the first break line 5 on both ends of the first break line 5. The air bag cover 3 also comprises a third break line 7 substantially vertically extending from a place facing to the outer periphery of the first break line 5 toward one of the upside and the downside. A pair of fourth break lines 8 extending in the opposite direction to the extending direction of the third break line 7 are disposed near both sides in the lateral direction of the design body 4 of the first break line 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile air bag cover structure, and more particularly, to an air bag of a vehicle in which the air bag cover can be radially deployed even if the air bag cover has a design body at a substantially central portion. The present invention relates to a back cover structure.

[0002]

2. Description of the Related Art Conventionally, in an automobile air bag cover structure, it is necessary to provide a predetermined breaking line in order to deploy the air bag cover.
The following examples are disclosed in Japanese Patent Laid-Open No. 163156 and Japanese Patent Laid-Open No. 2001-71853. The former discloses an example in which a design body such as a mark is attached to a substantially central portion of the airbag cover, and the airbag cover has a break line portion extending in the horizontal direction at both end sides of the design body. A pair of first rupture line portions extending substantially vertically to both ends of the rupture line portion, a second rupture line portion formed substantially along the outer periphery of the design body, and a lower side from the second rupture line portion And a break line portion extending to the air bag cover. According to such a prior art, the airbag cover can be deployed while avoiding the plate body. The latter discloses an example in which a design body such as a mark is not attached to substantially the center of the airbag cover, and the airbag cover is provided with a cross-shaped break line to deploy the airbag cover. It is like this. According to such a prior art, since the airbag cover can be radially deployed, the airbag can be uniformly deployed, and local impact on the occupant can be mitigated when the airbag is deployed. In addition, a so-called smart airbag is also known as an airbag for a vehicle, in which the deployment pressure of the airbag is variable according to the degree of collision at the time of vehicle collision and the load of an occupant.

[Problems to be Solved by the Invention]

By the way, when the design body is attached to substantially the center of the airbag cover as in the former prior art, there is a problem that the airbag cover does not spread radially.
That is, in the former prior art, since the breaking line for breaking in the left-right direction is not provided on the upper side of the airbag cover, the upper side of the airbag cover does not spread radially. In particular, when the smart airbag is combined with an airbag cover in which a design body is attached to approximately the center of the airbag cover as in the former prior art,
When the deployment pressure of the airbag is low, there arises a problem that the airbag is deployed in the vicinity of the occupant's chin. That is,
As shown in FIG. 1, when the airbag cover is deployed while the occupant's face is approaching the steering wheel, FIG.
First, the upper side piece of the deployed airbag cover collides with the occupant's jaw as shown in FIG. Then, the upper side piece of the airbag cover tries to deploy to the upper side, but if the airbag deployment pressure is low, it remains caught on the occupant's jaw even after deployment, as shown in FIG. 1 (b). Figure 1
As shown in (c), since the airbag deploys with the upper piece of the airbag cover being caught by the occupant's chin, the airbag is centrally deployed toward the vicinity of the occupant's chin, and the airbag is appropriately deployed. Will be hindered. Note that it is conceivable to provide a break line on the upper side of the airbag cover as in the latter prior art, but there is the following concern because the design body is located approximately in the center. (1) The design body falls off from the airbag cover when the airbag cover is deployed. That is, in order to break the airbag on the upper side in the left-right direction, it is necessary to provide a breaking line along the outer periphery on the upper side of the design body and to provide a breaking line extending from the breaking line to the upper side. You will need it. Therefore, a break line is formed over the entire outer circumference of the design body, and the design body is separated from the airbag cover when the airbag cover is deployed. There is a concern that it will be scattered toward. (2) When the design body is integrally formed with the airbag cover,
The airbag cover does not break. That is, when the design body is formed integrally with the airbag cover by making the thickness of only the design body thicker than other portions, the thickness of the design body can be provided even if the design body is provided with a break line. Since it is formed thick, there is a concern that it will not break when the airbag is deployed.

The present invention has been made in consideration of the above problems, and an object thereof is to suppress the adverse effect of the design body even when the design body is provided in the approximate center of the airbag cover. Another object of the present invention is to provide an airbag cover that can be deployed radially.

[0005]

In order to achieve the above object, the present invention has the following means for solving the problem. That is, the first configuration of the present invention is an airbag cover that is mounted on a steering wheel of an automobile and has a design body in a substantially central portion, and the design body is interposed between the airbag covers. A first rupture line which is formed so as to extend in the left-right direction while sandwiching it and which is formed along the outer periphery of the design body in the vicinity of the design body, and is formed on both ends of the first rupture line so as to extend in a direction substantially perpendicular to the first rupture line A pair of second rupture lines, and a third rupture line extending substantially vertically from a position along the outer circumference of the inner design body of the first rupture line to either the upper side or the lower side. In the airbag cover structure for an automobile, in the first breaking line, in the vicinity of both left and right ends of the design body, a pair of fourth breaking lines extends in a direction opposite to the extending direction of the third breaking line. It is configured such that the cross-sectional line is provided. According to the first configuration of the present invention, since the pair of fourth rupture lines is provided in the vicinity of both ends of the lateral direction of the design body, when the airbag cover is deployed, the fourth rupture line causes the upper side of the design body or One of the lower side airbag covers is divided into three parts in the left-right direction. Therefore, since the state in which the design body is attached to the airbag cover at the center of the three parts is maintained, it is possible to prevent the design body from falling off. Further, the airbag cover on either the upper side or the lower side of the design body is divided into three parts in the left-right direction, the area of the airbag cover is reduced, and its resistance can be reduced, so that the airbag deployment pressure is low. However, the airbag cover can be deployed radially.

In the second structure of the present invention, the airbag cover has a curved surface shape in the left-right direction, and the third breaking line is extended to the lower side of the design body. Moreover, the fourth breaking line is configured to extend above the design body. Since the airbag cover is mounted on the steering wheel, the surface shape of the airbag cover is curved in the left-right direction so that its appearance quality (look) does not deteriorate. However,
Since the bending rigidity of the airbag cover is increased by such curved formation, when the airbag cover collides with the occupant's jaw, the airbag cover cannot be easily deployed. According to the second configuration of the present invention, since the airbag cover on the upper side of the design body is horizontally divided into three, the bending rigidity of the central airbag cover that collides with the chin of the occupant can be reduced, The back cover can be deployed radially.

In the third aspect of the present invention, the fourth aspect described above is used.
The break line is configured to be fragile with respect to the second break line. According to the third configuration of the present invention, since the fourth breaking line is weakened with respect to the second breaking line, the airbag cover is radially arranged even when the airbag expanding pressure is set low. Can be deployed to.

[0008]

According to the present invention, even when the design body is provided substantially in the center of the air bag cover, it is possible to deploy the air bag cover in a radial manner while suppressing the adverse effect of the design body.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 2 is a front view of the airbag device 1.
In the above, the airbag device 1 is arranged at the center of a steering wheel (not shown) for an occupant to grip and steer, and the airbag device 1 is provided at two places on the left and right sides and one place on the lower side. Are connected to the spokes 2 of the steering wheel (in FIG. 2, only one on the right side of the drawing is disclosed). In the airbag device 1, an airbag cover 3 accommodates an airbag, an inflator for ejecting gas into the airbag, and an acceleration sensor (both not shown). The inflator is provided with a gas generating agent and an igniter for each of the compartments, and the number of igniting chambers is changed according to the magnitude of the acceleration detected by the acceleration sensor to change the gas pressure (airbag). It is configured to change the deployment pressure).

The airbag cover 3 is formed in a substantially hexagonal shape, and a symbol mark 4 (design body) which is a separate body is attached to the approximate center thereof. In addition, as shown in FIG. 2 which is a view taken in the direction of arrow A of FIG. 1, the airbag cover 3 has a surface shape 3a in the left-right direction which is close to the horizontal line L extending most in the left-right direction near the symbol mark 4, The curved shape is formed so as to move away from the horizontal line L as the distance from 4 increases.

Further, the airbag cover 3 has a first breaking line 5 which extends in the left-right direction with the symbol mark 4 interposed therebetween and which is formed along the outer periphery of the lower side of the symbol mark 4 in the vicinity of the symbol mark 4, and the first breaking line 5. The upper side (upper side in the drawing) of each of the first breaking lines 5 extends in a substantially vertical direction, and the lower side (lower side of the drawing) of each of the first breaking lines 5 extends. A pair of second break lines 6 formed to be curved in the left-right direction, and a substantially vertical direction extending downward from a position along the outer periphery of the first break line 5 on the lower side of the inner symbol mark 4 and thereafter. A third rupture line 7 is formed so as to branch in the left-right direction. In the present embodiment, the pair of fourth break lines 8 extending from the left and right ends of the symbol mark 4 toward the upper side of the symbol mark 4.
Are formed. The fourth breaking line 8 extends substantially parallel to the second breaking line 6 toward the upper side of the symbol mark 4 and has a length shorter than that of the second breaking line 6. Further, the fourth break line 8 is formed such that the depth of the break line is deeper than that of the first break line 5, the second break line 6, and the third break line 7 (the thickness of the airbag cover 6 is thin. ), It is fragile so that it can be broken even if the airbag deployment pressure is low.

Next, the operation and effect of this embodiment based on the above configuration will be described. When a vehicle sudden deceleration state is detected by the acceleration sensor, a control unit (not shown in the figure) equipped with the number of ignited chambers among a plurality of chambers filled with the gas generating agent according to the acceleration (deceleration) is detected. ), The ignition is performed by each of the ignition devices having the determined number of chambers. As a result, the gas generating agent burns to generate gas, which is then introduced into the airbag. As a result, the airbag expands, and when the inflation pressure acting on the airbag cover 3 reaches or exceeds a predetermined value, the airbag cover 3 is broken along the breaking lines 5-8. In particular,
An upper side portion 3b divided by the rupture of the first rupture line 5 and the second rupture line 6, an upper left side portion 3c, an upper right side portion 3d divided left and right by the rupture of the second rupture line 6, Due to the rupture of the third rupture line, the airbag cover 3 below the symbol mark 4 is divided into five parts, that is, a lower left part 3e and a lower right part 3f which are developed left and right.

Further, according to the first embodiment, the upper portion 3b is divided into three by the break of the fourth break line 8 and is expanded. Hereinafter, the operation and effect of the fourth break line 8 will be described in detail with reference to FIG. When the inflation pressure acting on the airbag cover 3 reaches or exceeds a predetermined value while the occupant's face is close to the steering wheel, the airbag cover 3 starts to fracture along the first fracture line 5 and the second fracture line 6. , The first breaking line 5 as shown in FIG.
The upper side portion 3b of the airbag cover 3, which is divided by breaking the second breaking line 6 and the second breaking line 6, expands toward the occupant's lower jaw. At this time, if the deployment pressure of the airbag is low,
The upper portion 3b of the airbag cover 3 remains hooked on the occupant's jaw, but the upper portion 3b of the airbag cover 3 along the fourth breaking line 8 weakened against the other breaking lines 5-7. The side portion 3b is broken, and the first upper piece 3g located on the left side in FIG. 1 and the second upper piece 3 located in the center.
h, and the third upper piece 3i located on the right side is divided into three.
Therefore, as shown in FIG. 4B, the first upper piece 3g and the third upper piece 3i which are not directly hooked on the chin of the occupant expand to the upper side. As a result, as shown in FIG.
The area of the upper side portion 3b of the airbag cover 3 is reduced by the amount of the first upper piece 3g and the third upper piece 3i, the resistance is reduced, and the bending rigidity of the airbag cover 3 is reduced. The piece 3h can be deployed on the upper side, and the airbag cover 3 is radially deployed. As a result, it is possible to prevent the airbag from being concentratedly deployed near the occupant's lower jaw. Further, when the upper side portion 3b of the airbag cover 3 is broken along the fourth breaking line 8, the symbol mark 4 is kept attached to the second upper piece 3h and falls off from the airbag cover 3. Is suppressed.

(Second Embodiment) FIG. 5 is a front view of an airbag device 1 according to the second embodiment, which is the same as the first embodiment except that the position of the fourth breaking line 8 is different.
The fourth breaking lines 8a and 8b in the second embodiment are extended to the upper side of the symbol mark 4 from the outer peripheral portion on the upper side of the symbol mark 4 slightly apart from the left and right ends of the symbol mark 4 or from the first breaking line. Has been done.
Although both the fourth break lines 8a and 8b are shown in FIG. 5, either one may be provided. In the second embodiment as well, as in the first embodiment, the upper portion 3b of the airbag cover 3 is divided into three parts, so the airbag cover 3
Is reduced and the bending rigidity of the airbag cover 3 is reduced, so that the second upper side portion 3h can be expanded to the upper side, and the airbag cover 3 is expanded radially. As a result, it is possible to prevent the airbag from being concentratedly deployed near the chin of the occupant. Also, the fourth
When the upper side portion 3b of the airbag cover 3 is broken along the breaking line 8, the symbol mark 4 indicates the second upper piece 3a.
The state of being attached to h is maintained, and falling off from the airbag cover 3 is suppressed.

In this embodiment, the third break line 7 is formed so as to extend below the symbol mark 4 and the fourth break line 8 is formed so as to extend above the symbol mark 4. On the contrary, the third breaking line 7 may be formed above the symbol mark 4 and the fourth breaking line 8 may be formed below the symbol mark 4 so that the airbag cover 3 is radially expanded. Further, in the present embodiment, the example in which the symbol mark 4 is attached separately from the airbag cover 3 is shown, but it may be formed integrally with the airbag cover 3. In this case, the thickness of the airbag cover 3 in the portion of the symbol mark 4 becomes thicker, but the fourth break line 8 is formed near the left and right ends of the symbol mark 4 while avoiding the symbol mark 4, so that the airbag cover 3 is formed. 3 is surely broken.

[Brief description of drawings]

FIG. 1 is an operation explanatory view for explaining a conventional problem.

FIG. 2 is a front view of an airbag according to the first embodiment.

FIG. 3 is a view on arrow A in FIG.

FIG. 4 is an operation explanatory view of the present embodiment.

FIG. 5 is a front view of an airbag according to the second embodiment.

[Explanation of symbols]

1: Airbag device 3: Airbag cover 4: Symbol mark (design body) 5: First breaking line 6: Second break line 7: Third breaking line 8: Fourth breaking line

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazutaka Ishikura             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation (72) Inventor Masayuki Furuya             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation F term (reference) 3D054 AA02 AA13 BB02 DD28 EE14                       EE30

Claims (3)

[Claims] 1. An airbag cover which is mounted on a steering wheel of an automobile and which is provided with a design body at a substantially central portion thereof. The airbag cover is arranged in the left-right direction with the design body interposed therebetween. A first rupture line which is formed to extend along the outer periphery of the design body in the vicinity of the design body, and a pair of first rupture lines formed on both ends of the first rupture line so as to respectively extend in a direction substantially perpendicular to the first rupture line. An airbag for an automobile provided with two break lines and a third break line extending substantially vertically from a position along the outer periphery of the inner design body of the first break line to either the upper side or the lower side. In the cover structure, a pair of fourth break lines extending in a direction opposite to the extending direction of the third break line is provided in the vicinity of both left and right ends of the design body within the first break line. The structure of the air bag cover of the automobile characterized by 2. The airbag cover has a curved surface shape in the left-right direction, the third breaking line is extended to the lower side of the design body, and the fourth breaking line is the design. The airbag cover structure for an automobile according to claim 1, wherein the airbag cover structure is extended to the upper side of the body. 3. The airbag cover structure for an automobile according to claim 1, wherein the fourth breaking line is weakened with respect to the second breaking line.