JPH0632223U - Car airbag cover - Google Patents

Abstract

(57) [Summary] [Purpose] By providing a guide groove in addition to the concave groove and the branch groove,
The moment load and tensile load applied to the mounting portion of the cover body are reduced, and the strength can be increased. [Structure] A groove 11 is formed so as to traverse the center of the inner wall surface of the top 10a of the cover body 10, and is formed along both edges of the inner wall surface of the top 10a of the cover body 10 from both ends of this groove 11. In addition to the pair of branch grooves 12 and 12,
While forming a continuous guide groove 13 bent to 2,
The end portions 13a of the guide grooves 13, 13 facing each other are brought close to each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cover for an automobile airbag.

[0002]

[Prior art]

 Airbags are attached to the steering wheel and instrument panel to protect the vehicle occupants from secondary collisions with the steering wheel and instrument panel in the event of a collision.

As such an airbag cover, the one described in Japanese Utility Model Laid-Open No. 2-100961 is known. That is, the one disclosed in Japanese Utility Model Laid-Open No. 2-100961 has a groove formed so as to traverse the central portion of the inner wall surface of the top of the cover body, and a peripheral edge portion of the inner wall surface of the top body from both ends of the groove. A cover for an automobile airbag having a straight groove formed along it, wherein the groove portion formed by the concave groove and the branch groove has an H shape, and the cover body is attached to the gas generator. The portion (end portion on the cover body side) is sandwiched between the retainer and the pressing plate and fastened by rivets.

[0004]

[Problems to be solved by the device]

 In the device described in the above publication, when the airbag is inflated, the cover body is ruptured along the H-shaped groove, but the pressure inside the airbag rises rapidly until just before this rupture. When the rupture started, the rupture proceeded rapidly, and the rupture of the cover body could not be stopped by the branch groove and could reach the side end portion of the cover body. If the breakage of the cover body reaches the side end, bending moment and tensile force are shocked to the cover body attachment portion, causing damage and scattering of the attachment portion, which may impair occupant safety. There was a drawback.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to reduce concentration of stress on a mounting portion for mounting a cover body on a gas generator. However, the present invention intends to provide a cover for an airbag of an automobile, which increases reliability in strength.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, an automobile airbag cover according to the present invention has a groove formed so as to traverse the central portion of the inner wall surface of the top of the cover body, and the inner wall surface of the top body of the cover body from both ends of the groove. In a cover for an airbag of a vehicle having a pair of branch grooves formed along the peripheral edge of the guide groove, the guide grooves are bent to form a continuous guide groove, and the ends of the guide grooves facing each other approach each other. I am allowed. Further, the depth of the guide groove is gradually reduced toward the end portion from the portion continuous with the branch groove. Further, an expanded portion is formed at an end of the guide groove, and an enclosing wall is formed so as to surround the expanded portion.

[0007]

【Example】

 Examples will be described with reference to the drawings. 10 is a cover body made of a thermoplastic elastomer. The cover body 10 includes a top portion 10a and side portions 10b extending downward from the four peripheral edges of the top portion 10a.

A concave groove 11 is formed on the inner wall surface of the cover top portion 10a so as to cross the central portion thereof. At both ends of the groove 11, branch grooves 12 are formed substantially linearly along the peripheral edge of the inner wall surface of the cover top 10a. The concave groove 11 and the branch grooves 12, 12 may be formed in an appropriate shape. The embodiment shown in FIGS. 1 and 2 is applied to four spokes, and in this case, it is formed to have an H-shape. The embodiment shown in FIG. 6 is applied to three spokes.

The recessed grooves 11 and the branch grooves 12, 12 are formed to facilitate breakage of the cover body 10. The thin portion formed by the recessed grooves 11 and the branch grooves 12, 12 is When the airbag is inflated, it is broken and the cover body 10 is deployed outward. The groove depths of the concave groove 11 and the branch grooves 12, 12 may be the same, or the depth of the concave groove 11 may be formed deeper than that of the branch grooves 12, 12 in order to facilitate the first breakage. You may do it.

At both ends of the branch groove 12, guide grooves 13 are formed so as to be bent and continuous with the branch groove 12, respectively. The guide grooves 13 may be formed so as to oppose each other along the peripheral edge of the inner wall surface of the cover body top portion 10a, and the ends thereof may approach each other. This guide groove 13 may be shorter than the length of the branch groove 12. Further, the guide grooves 13 and 13 located at both ends of the branch groove 12 may have the same length in the embodiment applied to the four spokes shown in FIGS. 1 and 2, and may have the same length as the three spokes shown in FIG. The lengths may be different in the applied embodiments.

The guide groove 13 is provided to prevent the cover body 10 from breaking at this portion when the airbag is inflated, and is gradually grooved from a portion continuous with the branch groove 12 toward the end 13 a. It is formed to have a shallow depth. In addition, in order to prevent the cover body 10 from being broken further, an extended portion 13b is formed at a portion of the inner wall surface of the cover body 10 corresponding to the end portion 13a of the guide groove 13, and at the same time, the extended portion 13b is formed. A surrounding wall 14 is formed so as to surround the expansion portion 13b.

Thus, when the airbag is inflated, the breakage of the cover body 10 along the concave groove 11 and the branch groove 12 can be stopped at the portion of the guide groove 13, and the cover body 10 can be stopped. It is possible to reduce the concentration of stress on the attachment portion 15 (the lower end portion of the cover body side portion 10b) attached to the 20, and to increase the reliability in strength.

Reference numeral 16 is a mounting hole provided in the mounting portion 15. The cover body 10 has a mounting portion 15 and a retainer 21 fastened together by rivets 22. In the present invention, it is possible to reduce the concentration of stress on the mounting portion 15 when the airbag is inflated, so that it is not necessary to use a pressing plate.

[0014]

[Action]

 When the airbag 23 is inflated at the time of a collision of an automobile or the like, the portion of the cover body 10 in which the concave groove 11 is formed is first broken, and then is broken along the branch grooves 12, 12 in a chain. Then, the break along the branch groove 12 is guided to the guide groove 13.

The guide grooves 13 are formed so as to face each other along the peripheral edge portion of the inner wall surface of the cover body top portion 10a, and since the end portions 13a thereof are close to each other, the cover body 10 is The guide groove 13 is easily bent between the opposite end portions 13a due to the hinge effect, the bending moment acting on the mounting portion 15 of the cover body 10 is reduced, and the tensile force applied to the mounting portion 15 is also reduced. Further, since the groove depth is formed so as to gradually become shallower toward the end portion 13a from the portion continuous with the branch groove 12, the resistance against breakage is larger than that at the other end portions. Further, since the expanded portion 13b is formed at the end 13a of the guide groove 13 and the surrounding wall 14 is formed so as to surround the expanded portion 13b, the stress is dispersed in the expanded portion 13b, and the guide groove 13 is formed. Breaks made along the edges are hard to reliably stop at their ends 13a. As a result, the fractured shape of the cover body 10 is stabilized, and as a result, the expanded shape of the airbag 23 is also stabilized.

[0016]

[Effect of device]

 The present invention is configured as described above, and in addition to the concave groove and the branch groove, the guide groove which is bent and continuous to the branch groove is provided in the cover body, and the ends of the guide grooves facing each other are close to each other. The moment effect and the tensile load applied to the cover body mounting portion when the airbag is inflated can be reduced by the hinge effect. In addition, since the groove depth of the guide groove is made to become gradually shallower toward the end than the part that is continuous with the branch groove, the moment load and tensile load applied to the cover mounting part due to the larger breaking resistance. Becomes smaller, and the strength reliability against these loads can be increased. Furthermore, since the expanded portion is formed at the end of the guide groove and the surrounding wall is formed so as to surround the expanded portion, breakage at this end can be prevented with certainty. As a result, the cover body can be attached to the retainer without using the pressing plate, the assembly is easy, the weight can be reduced, and a great economic effect can be achieved.

[Brief description of drawings]

FIG. 1 is a front view of a cover body.

FIG. 2 is a partial rear view of the cover body.

FIG. 3 is a partial cross-sectional view of a cover body.

FIG. 4 is a vertical sectional view of a cover body.

FIG. 5 is a sectional view of a guide groove end portion.

FIG. 6 is a rear view of the main part of another embodiment.

FIG. 7 is a cross-sectional view showing a mounted state of a cover body.

[Explanation of symbols]

 10 Cover Body 10a Cover Body Top 11 Recessed Groove 12 Branch Groove 13 Guide Groove 13a Guide Groove End 13b Extension 14 Surrounding Wall

Claims (3)

[Scope of utility model registration request] 1. A concave groove formed so as to cross a central portion of a top inner wall surface of the cover body, and a pair of branch grooves formed along both ends of the concave groove along a peripheral edge portion of the top inner wall surface of the cover body. The airbag cover for an automobile, wherein the guide groove is formed by bending the branch groove to form a continuous guide groove, and the ends of the guide grooves facing each other are close to each other. 2. The cover for an automobile airbag according to claim 1, wherein the guide groove has a groove depth that gradually decreases toward an end portion from a portion continuous with the branch groove. 3. The cover for an automobile airbag according to claim 1, wherein an expanded portion is formed at an end of the guide groove, and an enclosing wall is formed so as to surround the expanded portion.