JP3452620B2 - Module cover for airbag device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module cover of an air bag device, and more particularly to a module cover of an air bag device for a driver seat mounted on a steering wheel of an automobile, the module cover being accurately aligned with the tear line when the air bag is deployed. The present invention relates to a module cover improved so as not to be torn and scattered.

[0002]

2. Description of the Related Art An airbag device for a driver's seat of an automobile is installed in a central portion of a steering wheel. The airbag device for a passenger seat has an airbag attached to a mounting plate generally called a retainer. A module cover is attached so as to cover these. And
Generally, a rib (vertical wall) for fixing and fixing the retainer is formed on the back side of the module cover, and the bag can be housed inside the rib.

The module cover is provided with a slit so that it can be split at a predetermined line when the airbag is activated. Generally, in the case of the H shape, the slit is provided in the center of the airbag cover in the vehicle width direction, and in the vehicle front-rear direction along the left and right side edges and ribs of the cover. It is composed of a second slit.

This slit is known to be one in which a groove is continuously formed at the line to be cleaved, a perforation is formed, or the groove is deepened at intervals. There is. In addition, the module cover consists of a hard layer and a soft layer.
In the layered structure, there is also one in which slits are formed in the hard layer along the planned cleavage line.

[0005]

As described above, in the conventional airbag device, when the airbag is deployed, the first slit is first split, and the split is continuously propagated to the second slit. The cover tears open. At this time, there is known a technique in which the wall thickness is made thicker toward the outer peripheral side than the wall thickness of the central portion of the cover so that the cleavage can be performed accurately.

However in the case of the technique of changing the wall thickness, may tear line of the slit portion is Roken apparently, also during <br/> formed shape, there is a large part content and part mold cavity is small Therefore, there is a disadvantage that the fluidity of the resin material is likely to deteriorate.

An object of the present invention is to solve the above-mentioned problems of the conventional technique, and does not reveal the tear line in appearance,
To ensure the fluidity of the molding material at the time of forming the form is to provide a module cover of an airbag device with an improved cleavage of the module cover.

[0008]

A module cover for an airbag apparatus according to claim 1 of the present invention is a module cover for an airbag apparatus for an automobile, which is provided with a slit for tearing the module cover when the airbag is deployed. The slit is configured to continuously propagate from the initial cleavage portion to the final cleavage position in the vicinity of the hinge portion formation position, and between the initial cleavage portion and the final cleavage position, both side groove walls that form the slit. The angle of the small
It is characterized in that it is formed from a state to a large state .

[0009] module cover of the airbag apparatus according to the present claim 2 is the module cover of an automotive airbag device slit is provided for cleaving the module cover upon deployment of the air bag, the slit is opened裂初phase portion It is configured to continuously propagate to the final cleavage position in the vicinity of the formation position of the hinge portion, the slit bottom portion is formed with a rounded shape, and between the initial cleavage portion and the final cleavage position, the cleavage. The radius center distance in the radius shape of the initial portion side is formed into a radius shape shorter than the radius center distance of the radius shape of the final cleavage position side, and from the cleavage initial portion to the final cleavage position, a slit is formed. The gutter wall is characterized in that the angle is changed from a small angle to a large angle.

[0010]

In the invention according to claim 1 of the present application, the angle of the groove walls on both sides forming the slit is formed from a small state to a large state between the initial cleavage portion and the final cleavage position.
Also in this case, the initial cleavage portion side becomes sharper than the final cleavage position side, more susceptible to stress, and the cleavage easily propagates.

In the invention according to claim 2 of the present application, the initial cleavage portion
Minute to the final cleavage position, the slit bottom has an arc.
Is formed in the rounded shape on the initial side of the cleavage.
R-shaped arc whose center distance is near the final cleavage position.
Structure and request made in a round shape shorter than the center distance
This is a case where the configuration according to item 1 is used in combination, and such a configuration makes it easier to receive stress,
A synergistic effect can be produced.

Further, in any of the above cases, since the plate thickness of the module cover is not changed, the tear line is not exposed on the appearance, the fluidity of the molding material at the time of molding is secured, and the tear state of the module cover is improved. Can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.

[0014] FIGS. 1-8 show one embodiment of a steering wheel according to the present invention, FIG. 1 is a front view,
2 is a back view of the airbag cover, and FIG. 3 is AA of FIG.
2 is a sectional view, FIG. 4 is a sectional view taken along line BB in FIG. 2, and FIG.
C sectional view, FIG. 6 is a DD sectional view of FIG. 2, and FIG. 7 is E of FIG.
-E sectional drawing, FIG. 8 is FF sectional drawing of FIG.

As shown in FIG. 1, the steering wheel S of this embodiment has an annular grip portion 10a and four extended grip portions 10b extending inward from the annular grip portion 10a. The airbag device E is disposed inside the extended grip portion 10b. The airbag device E of this example has a bag 1, an inflator 2, a retainer 3, and a module cover 4 as main components.

In the retainer 3 of this embodiment, as shown in FIGS. 7 and 8, the central hole 3 for mounting the inflator 2 in the central portion.
2 is formed, and the peripheral edge of the opening of the bag 1 is held by the retainer 3 and the back ring 35, and is attached together with the inflator 2 and the retainer 3 by a fastener such as a screw, so that the retainer 3, the inflator 2, and the bag 1 are integrated. It is assembled. The bag 1 of this example is stored and held by a known means.

Further, a bent portion 33 bent toward the boss portion 5 side is formed on both end sides of the retainer 3 of this example, and the bent portion 33 has ribs 42 and ribs formed on the module cover 4 at predetermined positions. The boss plate 7 attached to the boss portion 5 and the boss plate 7 are fixed integrally by a fastener 8 such as a screw.

The module cover 4 of the present example, upper surface portion 41
Then, a rib 42 extending downward from the upper surface portion 41 is formed, and the rib 42 is formed so as to surround a range that covers the bag 1, the inflator 2, and the like.

[0019] Then on the back side of the module cover 4 of the present embodiment, as shown in Figure 2, central in the vehicle width direction (lateral direction Figure 2
The first slit 43 is formed in the left-right direction), and the second slit 44 in the direction perpendicular to the first slit 43 is formed inside the base portion of the rib 42 at the end 43a of the first slit 43. Formed on both ends of the slit 43 of the first slit 43 and the second slit 44, 44.
The H-shaped fracture line is formed at. Therefore, the initial cleavage portion is used as the central portion of the cover of the first slit, and is configured to continuously propagate from the second slit 44 to the final cleavage position in the vicinity of the formation position of the hinge portion 45.

As shown in FIGS. 3 and 4, the R1 and R2 are formed at the bottoms of the first slit 43 and the second slit 44. The center distance h1 of the R1 is the center distance h of the R2.
It is formed smaller than 2. That is, the radius center distance h1 in the radius shape on the initial cleavage side is shorter than the radius center distance h2 of the radius shape on the final cleavage position side.

The module cover 4 constructed in this way
In that case, the airbag expands and the module cover 4
When is pressed from the back side, the first slit 43 first starts cleavage, but at this time, the rounded shape R on the initial cleavage side is
No. 1 is sharper than the rounded shape R2 on the final cleavage position side, is more susceptible to stress, and the cleavage easily propagates.

[0022] That is, because it is formed in a state in which it is pointed in the central portion from the terminal 43 direction, stress first slit 4
The first part is applied to the central part which is the initial part of the cleavage of No. 3, and the part is cleaved at the central part, and this cleavage properly advances in the left-right direction toward the rib 42 direction. And this cleavage is the first slit 4
When reaching the end portion of 3, the cleavage surely changes the traveling direction because there is the rib 42 in the forward direction in which the cleavage has progressed, and the cleavage rapidly propagates to the second slit 44 side. Also the end of the first slit 43 and the hinge 4
Since the radius is different in the five directions, they are sequentially propagated.

In the above embodiment, an example in which the rounded shape of the bottom of the slit is changed is shown. However, as shown in FIGS. 5 and 6, both side grooves forming the slit are provided from the initial cleavage portion to the final cleavage position. The angle formed by the wall 43 may be gradually increased from a small state. Also in this case is towards the angle a open裂初phase partial side Ri by an angle b of the final cleavage position side, an acute angle, more susceptible to stress, readily cleaved is to propagate.

Further, both the rounded shape of the slit and the angles of both side groove walls forming the slit may be used together. That is, a round shape is formed at the bottom of the slit, and the round center distance in the round shape on the initial cleavage side is shorter than the round center distance of the round shape on the final cleavage position side between the initial cleavage portion and the final cleavage position. In addition to the above, it is also possible to form the slits on both side groove walls from a small state to a large angle between the initial cleavage portion and the final cleavage position.

As a matter of course, the slits may be formed only by the rounded shape, or may be formed only by changing the angles of the groove walls on both sides forming the slits.

[0026]

In the present invention, according to the present invention, since the forming angle of both side groove walls forming the slits from a small state to a large state, towards the open裂初phase portion side becomes sharp than that towards the final cleavage position, stress It becomes easy to receive, and the cleavage easily propagates.

From the initial cleavage portion to the final cleavage position
In the round shape in the round shape on the initial part side of cleavage
The center distance of the radius shape with the center distance at the final cleavage position side
By forming a shorter radius, the initial cleavage
The rounded shape on the minute side is the rounded shape on the final cleavage position side.
The combined use of the sharpened configuration and the angles of the groove walls on both sides forming the slit makes it easier to receive stress, and a synergistic effect can be achieved. Above either case, in order not to change the thickness of the module cover, without Roken the tear line on the appearance to ensure the fluidity of the molding material at the time of forming the shape, favorably improve cleavage state of the module cover You can

[Brief description of drawings]

FIG. 1 is a front view of a steering wheel according to the present invention.

FIG. 2 is a rear view of the airbag cover.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

5 is a sectional view taken along line CC of FIG.

FIG. 6 is a cross-sectional view taken along line DD of FIG.

7 is a sectional view taken along line EE of FIG.

8 is a sectional view taken along line FF of FIG.

[Explanation of symbols]

1 bag 2 inflator 3 retainer 4 module cover 10a annular grip part 10b Extended grip part 32 center hole 33 Bent 35 buckling 41 Upper surface 42 ribs 43 First slit 44 Second slit 45 Hinge part R1 are R2 are h1 center distance of R1 h2 center distance of R2 a Angle of initial cleavage side b Angle at the final cleavage position E Airbag device S steering wheel

Claims (2)

(57) [Claims] 1. A module cover for an automobile airbag apparatus, which is provided with a slit for opening the module cover when the airbag is deployed, wherein the slit is continuous from the initial opening portion and is close to the final position near the hinge formation position. An airbag characterized in that it is configured to propagate to a cleaving position, and between the initial cleaving part and the final cleaving position, the angle of both groove walls forming the slit is formed from a small state to a large state. Device module cover. 2. A module cover of an automobile airbag apparatus, which is provided with a slit for tearing the module cover when the airbag is deployed, wherein the slit is continuous from the initial tearing portion and closes to the hinge formation position. It is configured to propagate to the cleavage position, a round shape is formed in the slit bottom,
Between the cleavage initial portion and the final cleavage position, the radius center distance in the radius shape of the cleavage initial portion side is formed into a radius shape shorter than the radius center distance of the radius shape of the final cleavage position side, and the cleavage initial A module cover for an airbag device, characterized in that the angle of both side groove walls forming the slit is formed from a small state to a large state between the portion and the final cleavage position.