JPH06115404A - Lid member of air bag device - Google Patents

Abstract

PURPOSE:To provide a synthetic resin made lid member of an air bag device, which neither breaks nor damages an air bag when the air bag is expended, and which can obviate generation of any sink on its surface during its manufacturing process, can be equipped with a reinforcing rib on its back, and can be lightened. CONSTITUTION:A lid member 11 made of synthetic resin covers an air bag 1 folded in an air gag device M, opens when the air bag 1 is expanded, and comprises a reinforcing rib 13 formed on its back. The reinforcing rib 13 is formed in a semicylindrical shape whose section is semicircular, and has a hollow part 13a in its inside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device arranged in front of a passenger seat of a vehicle, a steering wheel or the like, and is made of a synthetic resin for covering an airbag which is expanded at a predetermined time and folded at a normal time. Regarding the lid material.

[0002]

2. Description of the Related Art Conventionally, for example, an airbag device arranged in front of a passenger seat has been disclosed in Japanese Utility Model Laid-Open No. 63-11135.
Known from Japanese Patent No. 3 etc., the lid material for covering the airbag is
It is mainly made of synthetic resin from the viewpoint of weight reduction, and
A metal plate was placed in place for reinforcement.

In this case, from the viewpoint of further weight reduction,
It is conceivable to provide a reinforcing rib integrally formed with the lid member on the back surface side portion of the lid member on which the metal plate is placed without disposing the metal plate.

However, when the air bag is expanded, a large impact force acts on the lid member, so that the reinforcing ribs need to be formed to have a large wall thickness and a high height.

Generally, the reinforcing rib provided on the synthetic resin product has a rectangular cross section, and when the reinforcing rib provided on the lid member of the airbag device is made thicker and higher, The following problems arise.

That is, when the airbag is expanded, the reinforcing ribs interfere with the airbag, which may damage the airbag or break the reinforcing ribs.

Further, sink marks due to molding shrinkage occur on the surface side of the lid member on which the reinforcing ribs are arranged, and the appearance is deteriorated.

Therefore, it has been practically impossible to use synthetic resin for all the lid members of the airbag device.

The present invention is to solve the above-mentioned problems, and provides a reinforcing rib on the back side without breaking the airbag or damaging the airbag when the airbag is opened, and eliminating sink marks generated during manufacturing. Accordingly, it is an object of the present invention to provide a synthetic resin lid member for an airbag device that can be made lighter.

[0010]

The lid member according to the present invention comprises:
As a synthetic resin, cover the folded airbag,
A lid member for an airbag device, which is opened when the airbag is expanded and has a reinforcing rib on the back surface, wherein the reinforcing rib is
It is characterized in that the cross section has a substantially half-cylindrical shape with a hollow portion inside.

The term "substantially half cylinder shape" means not only a half cylinder shape but also a polygonal cylinder shape such as a square cylinder shape with rounded corners or a triangular cylinder shape.

[0012]

In the lid member according to the present invention, the reinforcing rib has a cross section of a substantially half-cylindrical shape having a hollow portion inside.

That is, since the outer peripheral surface of the reinforcing rib is a substantially semi-circular arc surface, there is no risk of damaging the airbag even when it comes into contact with the expanding airbag, and the airbag is hooked. There is no danger of breaking.

Further, the reinforcing rib has a hollow portion even if its width and height are large, and since the wall thickness itself is thin, sink marks are generated on the surface side of the lid material due to molding shrinkage. hard.

The reinforcing rib of the lid member according to the present invention is a so-called gas injection molding (Japanese Patent Publication No. 57-149) in which an inert gas such as nitrogen gas is injected at the time of molding the lid member.
68, Japanese Patent Laid-Open No. 60-24913, etc.).

Therefore, the lid member made of the synthetic resin according to the present invention is provided with the reinforcing rib on the back side without breaking the airbag when the airbag is opened or damaging the airbag, and eliminating the sink marks generated during the production. It is possible to reduce the weight.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the lid member 11 of the embodiment is as follows.
Instrument panel P in front of the passenger seat of the car
It is used for the airbag device M arranged in the opening O of the.

The airbag apparatus M holds a folded airbag 1, a cylindrical inflator 2 for supplying gas for expanding the airbag 1, and a peripheral edge of the opening 1a of the airbag 1. In addition, it is composed of a case 3 that holds both ends of the inflator 2 and a lid 11.

The case 3 is a lower case 4 made of sheet metal.
And the upper case 5.

The lower case 4 is provided with a flange portion 4b having a plurality of mounting holes 4c extending outward in the horizontal direction and formed on an upper portion of a peripheral wall 4a having a bottomed and substantially square tube shape. On the peripheral wall 4a of the lower case 4, a tongue piece 4d whose upper side is separated from the peripheral wall 4a is fixed near the flange portion 4b. Further, the lower case 4 includes a bracket (not shown), and the bracket (not shown) is configured to attach and fix the airbag apparatus M to the vehicle body.

The inflator 2 has its both ends
It is inserted into both side surfaces (not shown) of the peripheral wall 4 a of the lower case 4 and held by the lower case 4.

In the upper case 5, a flange portion 5b extending inward in the horizontal direction and provided with a plurality of mounting holes 5c is formed in the lower portion of the peripheral wall 5a having a substantially rectangular tube shape. The tongue portion 5 extending downward is provided at the tip of the flange portion 5b of the upper case 5.
d is formed.

Then, while inserting the tongue portion 5d between the peripheral wall 4a and the tongue piece 4d, the flange portion 5b is placed on the flange portion 4b, and the opening portion 1a of the airbag 1 is placed on the flange portion 5b.
The lower case 4 and the upper case 5 are integrated and the airbag 1 is held by the case 3 by disposing the retainer 6 having the bolt 6a and fixing the retainer 6 with the nut 7 at the periphery.

Further, the peripheral wall 5a of the upper case 5 has a bracket 5 having bolts 5f and 5h on two predetermined outer surfaces.
e. 5g is fixed. The bracket 5e is for attaching the hinge portion 14 of the lid member 11 described later, and the bracket 5g is for attaching the breakaway portion 15 of the lid member 11 described later.

The lid member 11 is made of a synthetic resin such as PPO-PA alloy, and as shown in FIGS. 1 to 3, the lid body 12 has a substantially rectangular plate shape, and the lid body 12 has two sides in the longitudinal direction. The hinge portion 14 arranged on the back surface on one side and the two breakaway portions 15 arranged on the back surface on the other side.

The hinge portion 14 is formed with a predetermined number of mounting holes 14a into which the bolts 5f of the bracket 5e of the upper case 5 are inserted. The hinge portion 14 is attached to the bracket 5e by inserting each bolt 5f into a predetermined attachment hole 14a, interposing the contact plate 8 and screwing a nut 9 into each bolt 5f.
A reinforcing net 16 made of aramid fiber or the like is embedded at the intersection of the lid body 12 and the hinge portion 14. By the way, the insert 16 of the embodiment is the lid body 1
It also extends to the tip side of 2 and is buried.

Each breakaway portion 15 allows the lid body 12 to be separated from the case 3 (upper case 5) when the airbag 1 is expanded and a predetermined load is applied to the lid body 12. Is provided on the upper case 5
The mounting hole 15a into which each bolt 5h of the bracket 5g is inserted, and the slit 15b connected from the lower end to the mounting hole 15a are provided.

The slits 15b are provided so that the lid body 12 can be separated from the upper case 5, that is, the bolts 5h can be separated from the assembling holes 15a. In addition, in the case of the embodiment, in addition to the slit 15b, a thin wall portion 15c is formed at a portion of each breakaway portion 15 that is connected to the lid body 12, and the thin wall portion 15c is formed.
The lid body 12 can be separated from the lower case 5 even by breaking.

Then, on the back surface of the lid main body 12 of the embodiment,
Reinforcing ribs 13 are formed near the periphery of the three sides excluding the portion where the hinge portion 14 is arranged.
Is formed integrally with the lid main body 12 and has a hollow portion 13a inside and has a substantially half-cylindrical cross section.

In this reinforcing rib 13, as shown in FIGS. 4 and 5, the rib 13A on the long side of the lid main body 12 which opposes the hinge portion 14 has a wide width and a low height. The ribs 13B and 13B on the short side of the lid body 12 are configured to have a narrow width dimension and a high height.

The reinforcing ribs 13 are formed by gas injection molding for forming the hollow portion 13a by injecting an inert gas such as nitrogen gas when the lid material 11 is molded.

The lid member 11 having the above structure is attached to the contact plate 8
The airbag device M can be manufactured by attaching the airbag 1 and the inflator 2 to the case 3 in which the airbag 1 and the inflator 2 are assembled in advance using the nuts 9 and 10.

Then, after fixing the airbag device M to a predetermined position below the instrument panel P of the automobile, when the airbag 1 is expanded by the gas from the inflator 2, the respective breakaway parts 15 are assembled. The bolt 5h comes off from the attaching hole 15a through the slit 15c, or the thin portion 15c is broken, and the lid body 12 of the lid member 11 rotates around the intersection of the hinge portion 14 and the lid body 12. The airbag 1 is expanded and the airbag 1 is greatly expanded.

At this time, since the reinforcing rib 13 has an outer peripheral surface which is a substantially semi-circular arc surface, the airbag 1 is expanded.
Even if the airbag 1 comes into contact with the airbag 1, there is no risk of damaging the airbag 1, and since the airbag 1 is not caught, there is no risk of breaking.

Particularly, in the reinforcing rib 13 of the embodiment, the rib 13A at a portion that is rubbed with the airbag 1 a lot.
However, since the height is reduced, the above effect is further promoted.

Further, the reinforcing rib 13 is provided with the hollow portion 13a even if its width and height are increased,
Since the wall thickness itself is thin, it is difficult to cause sink marks on the surface side of the lid member 12 due to molding shrinkage, and the same effects as those described in the section of the operation and effect of the invention described above are achieved.

In the embodiment, the reinforcing ribs 13 to be arranged on the lid body 12 are provided on three sides except the side on which the hinge portion 14 is arranged. However, the reinforcing rib 1
The portion where 3 is arranged is set according to the portion to be reinforced, and like the lid member 21 as shown in FIG. 6, the reinforcing portion provided with the hollow portion 23a only on the short side of the lid body 22. The ribs 23 may be provided.

By the way, like the lid members 11 and 21, in the direction orthogonal to the rotating central axis X of the lid bodies 12 and 22 (direction in which the hinge portion 14 is formed, see FIGS. 2 and 6), and Reinforcing ribs 13 are provided near the breakaway portion 15.
When B.23 is arranged, the force to deploy the lid bodies 12 and 22 along with the expansion of the airbag 1 (rotational force of the lid bodies 12 and 22 around the hinge portion 14). ) Can be smoothly transmitted to each breakaway portion 15.

Further, in the lid material 11, the reinforcing ribs 13 are provided.
Are arranged on three sides of the lid main body 12 excluding the portion where the hinge portion 14 is arranged, and the strength of shape retention of the peripheral edge of the lid main body 12 (that is, the peripheral edge of the lid main body 12 against bending moment). The strength for maintaining the square plate shape is increased, and when the lid body 12 is unfolded, the two breakaway parts 1
The expanding force of the airbag 1 can be easily exerted on 5 simultaneously and evenly, and the strength of the breakaway portion 15 and the hinge portion 14 can be easily set.

The reinforcing ribs 13 and 23 are attached to the lid main body 12.
It is not desirable to form only in the lateral direction of the center of 22. This is because the central strength of the lid bodies 12 and 22 is increased, and the impact force that the airbag 1 is instantly expanded causes the lid body 12 before the breakaway portions 15 on both sides are actuated.
This is because the center of 22 may be broken.

Further, in the embodiment, the breakaway unit 1
Although the lid members 11 and 21 used for the passenger seat airbag apparatus M having the fifth embodiment have been described, it goes without saying that not only the airbag apparatus for the passenger seat, which does not include the breakaway portion 15, but also the steering wheel The present invention can be applied to the pad of the airbag device arranged on the wheel.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mode of use of an airbag device in which a lid member according to an embodiment of the present invention is arranged.

FIG. 2 is a perspective view of the lid member of the embodiment viewed from above.

FIG. 3 is a perspective view of the lid member of the embodiment as viewed from below.

4 is a cross-sectional view taken along the line IV-IV in FIG.

5 is a cross-sectional view taken along the line VV in FIG.

FIG. 6 is a perspective view showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Airbag, 11 * 21 ... Lid material, 13 * 23 ... Reinforcing rib, 13a * 23a ... Hollow part, M ... Airbag apparatus.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Kuriyama 1 Ochiai, Nagachi, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd. Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A lid member for an airbag device, which is made of synthetic resin, covers a folded airbag, opens when the airbag is expanded, and has a reinforcing rib on a back surface thereof. However, the lid member of the airbag device is characterized in that its cross section is formed into a substantially half-cylindrical shape having a hollow portion inside.