JP2532284B2 - Automotive airbag device and method for assembling the same - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile airbag device and a method for assembling the same.

(Prior Art) An airbag device is a safety device against a collision of an automobile. This airbag device comprises an airbag unit equipped with an airbag, a gas generator, etc., which is arranged in an opening formed at a predetermined position on the passenger side of the instrument panel. At the time of a collision, the gas generator is activated to inflate and deploy the airbag, which
It protects the head and chest of an occupant who wants to move forward in the event of a collision.

In such an airbag device, a cover member that is substantially continuous to the other portion of the instrument panel, that is, an air bag grid is provided in the opening portion.
The airbag is automatically opened by the deploying force of the airbag. As a mechanism for opening this air bag grid,
Conventionally, for example, as disclosed in Japanese Utility Model Laid-Open No. Sho 63-176749, a hinge composed of a curved member,
As disclosed in Japanese Patent Publication No. 7055-, a hinge mechanism having a linear pivot axis extending in the vehicle width direction, such as a hinge formed of a plurality of plate members, is used between the instrument panel and the air bag grid, and As a mechanism for holding the air bag grid in a closed state, conventionally, for example, as disclosed in Japanese Utility Model Laid-Open No. 63-176749,
A fitting structure of a protruding member and a hole to which a locking member made of an elastic body is fixed has been used between the air bag grid and the member on the vehicle body side.

(Problems to be solved by the invention) However, in the recent instrument panel designed to be smoothly continuous with the side door to improve the appearance, both sides of the instrument panel, and by extension, the air bag grid are Since it is curved to the rear of the vehicle body, there is a problem that the air bag grid cannot be opened by a conventional hinge mechanism having a linear pivot extending in the vehicle width direction. Further, in the air bag grid closing mechanism including the conventional fitting structure of the projection member and the hole, there is a problem that the projection part may interfere with the occupant when the air bag grid is opened.

Therefore, an object of the present invention is to provide an air bag grid that can be opened even in an instrument panel whose both sides are curved rearward of the vehicle body. Another object of the present invention is to provide a mechanism for holding the air bag grid in a closed state, which does not interfere with an occupant when the air bag grid is opened.
Still another object of the present invention is to provide a method for assembling an airbag device having an airbag bag which can be opened even in an instrument panel whose both sides are curved rearward of the vehicle body, into a vehicle body.

(Means for Solving the Problems) In order to solve the above problems, the invention of claim 1 has an opening formed at a predetermined position on the passenger seat side of the instrument panel, and the airbag is provided at the opening. And an airbag unit having a casing or the like for accommodating the airbag is supported by the vehicle body-side member, and the opening of the instrument panel normally covers the opening and rotates when the airbag is inflated. Assuming an air bag system for an automobile to which an air bag grid that expands while moving is attached, the air bag grid and the vehicle body side member or the airbag unit are connected by a stretchable belt member. Provide a bag device.

Further, according to the invention of claim 4, an opening is formed at a predetermined position on the passenger seat side of the instrument panel, and an airbag unit having an airbag, a casing for accommodating the airbag and the like is provided in the opening portion. An air bag for an automobile, which is provided so as to be supported by a vehicle body-side member, and which has an air bag grid attached to the opening of the instrument panel, which covers the opening in normal times and expands while rotating when the airbag is inflated. On the premise of a back device, the air bag grid and the vehicle body side member or the airbag unit are connected by a belt member, and the belt member is in a normal state and the belt member mounting position of the air bag grid and the vehicle body side. A vehicle air bag having a length longer than the distance between the belt member mounting position of the member or the airbag unit. To provide a grayed apparatus.

Further, according to the invention of claim 7, an instrument panel having an airbag opening preformed at a predetermined position on the passenger side is fixed to the vehicle body with the opening opened, and the airbag unit is provided with the instrument panel. Through the opening for the airbag of the instrument panel, inserted into the opening for the airbag, through the opening for the airbag of the instrument panel, the airbag unit is fixed to the vehicle body, the air bag grid, the air of the instrument panel. An air bag for a vehicle that is attached to the bag opening, closes the air bag grid, closes the air bag opening provided in the instrument panel, and uses an air bag grid closing means to hold the air bag grid closed. A method of assembling a bag device is provided.

(Operation) In the first to third aspects of the present invention, the air bag grid is connected to the vehicle body side member or the like by the stretchable belt. Furthermore, claim 4 to claim 6
In the invention of, the air bag grid, in normal times, the belt member mounting position of the air bag grid,
A belt member having a length longer than the distance between the vehicle body side member and the belt member mounting position is connected to the vehicle body side member. Therefore, when the airbag is deployed, the airbag bag pivots around the belt attachment portion of the airbag bag with the belt member fully extended or in a fully extended state. That is, the center of rotation of the air bag grid when the airbag is deployed is located closer to the vehicle compartment than the instrument panel.

Further, in the inventions of claims 7 to 9, in a state where an airbag opening formed in advance in the instrument panel is opened, the airbag unit is inserted into the opening through the opening, and the airbag unit is inserted into the vehicle body through the opening. Since the air bag unit is attached, the air bag unit can be attached while confirming the relative positional relationship between the opening and the air bag unit.

(Embodiment) FIG. 1 is a view showing an instrument panel of an automobile in which an airbag device according to an embodiment of the present invention is incorporated, and FIG. 2 is taken along line AA of FIG. FIG.

In FIGS. 1 and 2, reference numeral 1 indicates an instrument panel of an automobile, and the instrument panel 1 is provided at a predetermined portion on the passenger side of the instrument panel.
An opening 1a elongated in the vehicle width direction is formed between the top deck 1b and the sidewall 1c, and the airbag device 2 according to the embodiment of the present invention is incorporated in the opening 1a.

The structure of the vehicle body in which the airbag device 2 is incorporated is almost as follows.

That is, as shown in FIG. 2, the dash upper panel 4 is joined to the upper end of the dash lower panel 3 located at the rear end of the engine room, and the cowl upper panel 5 is attached to the upper end of the dash upper panel 4. Joined at the edges. Further, although not shown, a cowl front panel is joined between the front end of the cowl upper panel 5 and the dash upper panel 4 to form a cowl box 6 having a cowl closed cross section extending in the vehicle width direction. ing.

A windshield 7 is fixed to a predetermined portion of the cowl upper panel 5 with an adhesive 8.

Further, a cleaning unit 9 as an air conditioner is disposed in the internal space of the instrument panel 1 below the dash upper panel 4 and behind the dash lower panel 3. A defroster nozzle 10 is provided on the lower surface of the top deck 1b of the instrument panel 1 to blow warm air from the cleaning unit 9 to the front windshield 7 through a differential door to prevent the front windglass 7 from being fogged. Has been. At the rear position of the cleaning unit 9, the glove tray 11, the glove lid 12, and the glove pocket 13 are provided.
There is provided a glove box 14 provided with.

A steering support member 15 is disposed on the upper rear side of the cleaning unit 9. The steering support member 15 extends in the vehicle width direction, and both ends of the steering support member 15 are hinge pillars (not shown) on both sides via brackets 15a.
It is connected to. The steering support member 15 and the instrument panel 1 are connected to each other by a fastening member (not shown).

A bracket 16 is fixed to the steering support member 15, and the airbag unit 20 of the airbag device 2 is attached to the bracket 16 by a front mounting method.

The airbag unit 20 is, as shown in FIG.
Seat side, that is, a casing 21 having an opening 21a opening toward the opening 1a side of the instrument panel and a flange 21b surrounding the opening 21a, an airbag 22 accommodated in a folded state in a casing 21, this airbag Gas generator 2 for generating gas to be introduced into 22
3. The upper lid 24a and the lower lid 24b, which are cover members for covering the opening 1a of the instrument panel, are formed.

As shown in FIG. 3 which is a BB arrow view of FIG. 2 with the lids 24a, 24b open, the airbag unit 20
The flange portion 21b of the casing 21 is attached to the bracket 16 by the bolts and nuts 25 at both ends in the vehicle width direction.
By being fastened to the steering support member 15
It is fixed to.

Fig. 3 and the third with the lids 24a, 24b closed
As shown in FIG. 4 which is a cross-sectional view taken along the line CC in the drawing, one end of the top plate 21c of the casing 21 in the vehicle width direction is connected to the other end by the fastening members 26a extending in the vehicle width direction. Is a belt 27a which is fixed to the upper lid 24a so as to be rotatable about the longitudinal axis of the fastening member 26a and which can be expanded and contracted in the vehicle longitudinal direction.
Are connected to both ends of the upper lid 24a facing each other. Similarly, both ends of the bottom plate 21d of the casing 21 in the vehicle width direction are rotatable about the longitudinal axis of the fastening member 26b by the fastening member 26b extending in the vehicle width direction at one end to the bottom plate 21d and the other end to the lower lid 24b. The fixed lower lid 24b that faces the front and rear direction of the vehicle by the fixed belt 27b.
Are connected to both ends of each. As shown in FIG. 4, the belt 27a is formed to be sufficiently longer than the distance between the belt attachment positions of the casing top plate 21c and the lid 24a when the lid 24a is closed, and the belt 27b is formed by the lid 2a.
It is formed to be sufficiently longer than the distance between the belt attachment positions of the casing bottom plate 21d and the lid 24b when the 4b is closed.

Fig. 3 and the third with the lids 24a, 24b closed
As shown in FIG. 5 which is a cross-sectional view taken along line D-D in the figure, closure fasteners 28a and 28b are provided at both ends of the lids 24a and 24b in the vehicle width direction.
28a and 28b are engagement holes 29a formed in the receiving member 29 fixed to the flange portion 21b of the casing 21 by the bolts and nuts 25 at both ends in the vehicle width direction when the lids 24a and 24b are closed. , 29b, respectively. As shown in FIG. 5a, which is a view taken along the line FF of FIG. 5, the closing fastener 28a is offset in the vehicle width direction, and as a result, the fragile portion 28a ₁ is formed in the fastener 28a. Similarly, the fastener 28b has a fragile portion.

Fig. 3 and the third with the lids 24a, 24b closed
As shown in FIG. 6 which is a cross-sectional view taken along the line EE in the figure, closing clips 30a and 30b are respectively provided at the upper edge of the lid 24a and the lower edge of the lid 24b at both ends in the vehicle width direction. The clips 30a, 30b are arranged on the lids 24a, 24b.
Instrument panel top deck 1b when closed
Lower edge 1b ₁ , instrument panel sidewall 1
It is adapted to respectively engage with the upper edge portion 1c _{1 of} c.

The airbag device 2 according to the present embodiment having the above structure
In, when a car collides, a collision sensor (not shown) detects this collision, ignites a chemical substance contained in the gas generator 23 by an igniter (not shown), and the gas generated from the chemical substance is introduced into the airbag 22. When introduced, the airbag 22 is inflated and deployed, thereby protecting the head and chest of the occupant who wants to move forward during a collision.

At this time, due to the deploying force of the airbag 22 at the initial stage of deployment, as shown in FIG.
The fragile portion 28a ₁ is broken, and then the engagement between the closing clip 30a and the lower edge portion 1b ₁ of the instrument panel top deck 1b is released. As a result, the upper lid 2 connected to the top plate 21c of the casing 21 by the sufficiently long belt 27a.
4a, when the airbag 22 is deployed, as shown by the alternate long and short dash line in FIG. 4, from the closed state in which the instrument panel 1 is engaged, the engagement is released, and the vehicle temporarily moves rearward in parallel. After that, it rotates counterclockwise around the upper edge as the center of rotation and rides on the instrument panel top deck 1b. Similarly, as the airbag 22 is deployed, the lower lid 24b is disengaged from the closed state in which it is engaged with the instrument panel 1 as shown by the alternate long and short dash line in FIG. Then, the vehicle moves in parallel with, and then rotates clockwise around the lower edge as the center of rotation to ride on the instrument panel sidewall 1c. In this way, when the airbag 22 is deployed, the engagement between the lids 24a, 24b and the instrument panel 1 is released, so that both sides of the instrument panel 1, and by extension, the lids 24a, 24b are curved toward the rear of the vehicle body. However, the lids 24a and 24b can be easily opened.

Further, since the belts 27a and 27b are capable of expanding and contracting in the vehicle front-rear direction, when the lids 24a and 24b are opened as the airbag 22 is deployed, the fastening members 26a and 26b, and eventually the casing top plate 21.
c, casing bottom plate 21d, fastening members 26 such as lids 24a, 24b
No excessive force is applied to the parts near a and 26b.

Further, as shown in FIG. 5b, the closure fastener 28
In the initial stage of the deployment of the airbag 22, the a is fragile due to its deployment force, the fragile portion 28a ₁ is broken, and is divided into the lid 24a side portion and the receiving member 29 side portion. The fastener 28a does not exist. Therefore, when the upper lid 24a is opened as the airbag 22 is deployed, there is no possibility that the fastener 28a as such a protrusion interferes with the passenger in the passenger seat. The same applies to the closure fastener 28b.

FIG. 5c shows another embodiment of the closing fastener.
In the embodiment of the 5c view, fastener 28a 'is U-shaped portion 28a _1' provided with a, is, bend 28a ₂ of the U-shaped 'form a fragile portion. Even in the present embodiment, as can be seen from FIG. 5d, the closing fastener 28a ′ has a weakened portion due to its deployment force at the initial stage of deployment of the airbag 22.
Since the 28a ₂ ′ is broken and divided into a lid 24a side portion and a receiving member 29 side portion, the upper lid 24a no longer has the fastener 28a ′ as a protrusion.

Next, a first method of assembling the airbag device according to the present invention will be described.
A description will be given based on FIG. 3, FIG. 5, and FIG.

The assembly of the airbag device 2 to the vehicle body is performed in the following procedure.

The instrument panel 1 to which the steering support member 15 is attached in advance is fixed to the vehicle body by connecting both end brackets 15a of the steering support member 15 to hinge pillars (not shown) on both sides of the vehicle body (first
Figure).

Although the lids 24a and 24b are shown in FIG.
At this stage, the lids 24a and 24b are not yet attached to the instrument panel 1.

In the opening 1a of the instrument panel 1, the belt 27
Insert the airbag unit 20 (excluding the lids 24a and 24b) to which a and 27b are preliminarily attached, and support both ends of the casing flange portion 21b in the vehicle width direction with the receiving member 29 by the bolts and nuts 25 to support the steering. It is fastened to the bracket 16 fixed to the member 15. As a result, the airbag unit 20 is fixed to the instrument panel 1 (Fig. 7).

The belt 27a is fastened to the upper lid 24a to which the closing fastener 28a and the closing clip 30a are attached in advance.
26a, the belt 27b is attached to the lower lid with the closing fastener 28b and the closing clip 30b attached in advance.
It is attached to 24b using the fastening member 26b (Fig. 3).

The closing clip 30a of the upper lid 24a to the lower edge 1b ₁ of the instrument panel top deck 1b, the lower lid 24b
Closing clip 30b respectively engaged engaged to the upper edge 1c ₁ of the instrument panel side walls 1c and the upper lid 24a in the clockwise direction as viewed in FIG. 6, by rotating respectively the lower lid 24b in the counterclockwise direction, Closure fasteners 29a, 29b
Are fitted into the engaging holes 29a and 29b of the receiving member 29 (FIGS. 5 and 6).

Through the above steps, the assembling of the airbag device 2 to the instrument panel 1 is completed.

According to this assembling method, after mounting the instrument panel 1 in which the steering support member 15 is incorporated in advance on the vehicle body, the airbag unit 20 is attached to the steering support member 1 through the opening 1a of the instrument panel 1.
Since it is fixed to the bracket 16 fixed to, the position of the airbag unit 20 and the opening 1a of the instrument panel can be easily and accurately aligned, and the assembly of the airbag unit 20 can be easily and accurately performed.

FIG. 8 shows another embodiment of the airbag device according to the present invention. FIG. 8 is a first part of an airbag device according to the present invention.
5 is a drawing corresponding to FIG. 5 in the embodiment of FIG. In the airbag device according to this embodiment, the lids 24a ′, 24
In b ′, the closing fastener, the closing clip, and the receiving member of the closing fastener are not arranged, but instead, the hemispherical projections 24 for positioning are provided at both ends in the vehicle width direction.
a ₁ ', 24b _1' and, closing cord 31a, and the 31b are disposed respectively. On the other hand, the protrusions 24a ₁ ′, 2 are provided at both ends in the vehicle width direction of the flange portion 21b ′ of the airbag unit casing.
4b ₁ 'projections 24a ₁ at a position facing the' 24b ₁ are the forms' and the positioning hemispherical recess 21b ₁ complementary shape ', also in the vehicle width direction end portion and the both end portions of the flange portion 21b' A hole 32a for passing the closing string 31a and a hole 32b for passing the closing string 31b are formed through the supporting bracket 16 '. The airbag device according to the present embodiment has the same configuration as the airbag device according to the first embodiment except for the above points.

Of the airbag device according to the present embodiment having the above configuration,
The method of assembling to the instrument panel is the same as the method of assembling the airbag apparatus according to the first embodiment up to the steps, but the steps are different. Ie belt 27
After connecting a and 27b to the lids 24a 'and 24b', respectively,
The strings 31a and 31b are passed through the holes 32a and 32b, respectively, and a hand is inserted into the instrument panel 1 from below the instrument panel 1, and the strings are passed through the guide rollers 33a and 33b provided in the instrument panel 1. 31a and 31b are pulled downward inside the instrument panel 1. As a result, the lid 24a ', 24b' are positioning hemispherical recess whose vehicle transverse direction both end portions positioning hemispherical projections 24a ₁ formed in ', 24b _1' is formed in the flange portion 21b of the airbag unit casing ' closed with fitted state 21b ₁ '. In this state, the ends of the strings 31a and 31b are fixed to the spring 34 attached to the vehicle body side, and the lids 24a 'and 24b' are kept closed under the urging force of the spring 34.

When deploying the airbag, at the initial stage of deploying the airbag, the deploying force causes the strings 31a and 31b to break,
As a result, as the airbag expands, the lids 24a 'and 24b' are opened in the same manner as the airbag device according to the first embodiment.

In the airbag device according to the present embodiment, since there are no protruding members for closing the lid such as fasteners and clips, further safety is ensured when the airbag is deployed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims. Nor. For example, one ends of the belts 27a and 27b may be connected to the vehicle body side member instead of the airbag unit casing 21.

(Effect) As described above, in the present invention, the opening is formed at the predetermined position on the passenger side of the instrument panel,
An air bag unit having an air bag and a casing for accommodating the air bag is provided in the opening portion so as to be supported by a vehicle body side member, and the opening of the instrument panel covers the opening. In an automobile airbag device provided with an air bag grid, since the vehicle body side member or the air bag unit and the air bag grid are connected by a belt member, when the air bag is opened, the air bag grid is not engaged with the instrument panel. It is released and then opens with the deployment of the airbag. Therefore, the air bag grid can be opened even if the instrument panel and thus the air bag grid is curved rearward of the vehicle body.

Further, in the present invention, the member for holding the air bag grid provided in the air bag device in a closed state is provided with the air bag grid when the air bag grid is opened as the air bag is deployed. Since it does not protrude from the grid, there is no risk of interference with the occupant when the air bag grid is opened. Further, in particular, by using a string-like member for holding the air bag grid in the closed state, it is possible to completely eliminate the possibility of interfering with an occupant.

In the present invention, the airbag unit is attached to the vehicle body side member through an opening formed at a predetermined position on the passenger side of the instrument panel, and an air bag grid covering the opening is opened. Since the airbag device is assembled to the vehicle body by mounting it on the vehicle body side member or the airbag unit, closing the airbag bag, and holding the airbag bag in the closed state, the airbag unit and the opening of the instrument panel are aligned. The air bag device can be assembled easily and accurately.

Therefore, the present invention provides an air bag grid that can be opened even in an instrument panel whose both sides are curved rearward of the vehicle body. Further, according to the present invention, a mechanism for holding the air bag grid in a closed state,
A mechanism is provided that does not interfere with an occupant when the air bag grid opens. Further, according to the present invention, there is provided a method of mounting an airbag device having an airbag bag, which can be opened even in an instrument panel whose both sides are curved rearward of a vehicle body, on a vehicle body.

[Brief description of drawings]

FIG. 1 is a view showing an instrument panel of an automobile in which an airbag device according to an embodiment of the present invention is incorporated, and FIG. 2 is a sectional view taken along the line AA in FIG. . 3 is a BB arrow view of FIG. 2 with the air bag grid open, FIG. 4 is a cross-sectional view taken along the line CC of FIG. 3, and FIG. 3 is a sectional view taken along the line DD of FIG. 3, and FIG. 6 is a sectional view taken along the line EE of FIG. 5a is a view taken along the line FF of FIG. 5, and FIG. 5b is a view taken along the line FF of FIG. 5 when the air bag grid is opened. 5c and 5d are views corresponding to FIGS. 5a and 5b, respectively, showing another embodiment of the lid closing fastener. FIG. 7 is a view showing an assembled state when fixing the airbag unit (excluding the airbag bag) to the steering support member. FIG. 8 is a view showing another embodiment of the airbag device according to the present invention. 1 ... Instrument panel, 1a ... Opening, 1b ... Top deck, 1c ... Sidewall, 2 ... Airbag device, 20 ... Airbag unit, 21 ... Casing,
21a ... Opening, 21b ... Flange, 21b '... Flange, 21b ₁ ' ... Positioning hemispherical recess, 21c ... Casing top plate, 21d ... Casing bottom plate, 22 ... Airbag, 23 ... Gas generator, 24a, 24b ... Air bag grid, 24a ', 24b' ... Air bag grid, 24a ₁ ', 24
b ₁ ′ …… positioning hemispherical protrusion, 25 …… bolt / nut, 26a, 26b …… lid fastening member, 27a, 27b …… belt, 28a, 28b …… lid closing fastener, 28a ₁ …… fragile part , 28a ′ …… Lid closure fastener, 28a ₁ ′ ……
U-shaped part, 28a ₂ '... weak part, 29 ... receiving member, 29
a, 29b ... Engagement hole, 30a, 30b ... Lid closing clip, 31a, 31b ... Lid closing string, 32a, 32b ... Hole, 33
a, 33b …… Guide roller, 34 …… Spring.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisao Muramoto 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References: 63-111353 (JP, U) 5-33421 (JP, Y2) US Patent 3708179 (US, A) US Patent 3966227 (US, A) US Patent 3822894 (US, A)

Claims (9)

(57) [Claims] 1. An opening is formed at a predetermined position on the passenger seat side of an instrument panel, and an airbag unit having an airbag and a casing for accommodating the airbag is formed in a vehicle body side member at the opening. In an airbag device of a vehicle, which is provided so as to be supported, the opening of the instrument panel covers the opening in a normal state, and an air bag grid which is expanded while rotating when the airbag is inflated is attached, The air bag grid and the vehicle body side member or the airbag unit are connected by a stretchable belt member,
An airbag device for an automobile, which is characterized by the following. 2. A member for holding the air bag grid in a closed state, wherein the member does not project from the air bag grid when the air bag grid is opened as the airbag is deployed. 2. The air bag grid is provided on the air bag grid.
The airbag device described in. 3. A member for holding the air bag grid in a closed state, wherein the member does not project from the air bag grid when the air bag grid is opened as the airbag is deployed. Is a string-like member that breaks under a predetermined load.
The airbag device described in. 4. An instrument panel is provided with an opening at a predetermined position on the passenger side, and an airbag unit having an airbag, a casing for accommodating the airbag, and the like is formed in a vehicle body side member at the opening. In an airbag device of a vehicle, which is provided so as to be supported, the opening of the instrument panel covers the opening in a normal state, and an air bag grid which is expanded while rotating when the airbag is inflated is attached, The air bag grid and the vehicle body side member or the air bag unit are connected by a belt member, and the belt member has a belt member mounting position of the air bag grid and the vehicle body side member or the air bag unit in normal times. The vehicle has a length longer than a distance between the belt member mounting position and the belt member mounting position. A bag device. 5. A member for holding the air bag grid in a closed state, wherein the member does not project from the air bag grid when the air bag grid is opened as the airbag is deployed. 5. The air bag grid is provided on the air bag grid.
The airbag device described in. 6. A member for holding the air bag grid in a closed state, wherein the member does not project from the air bag grid when the air bag grid is opened as the airbag is deployed. Is a cord-like member that breaks under a predetermined load.
The airbag device described in. 7. An instrument panel having an airbag opening formed in advance at a predetermined position on the passenger seat side is fixed to a vehicle body with the opening open, and an airbag unit is attached to the airbag of the instrument panel. Through the opening for the bag, inserted into the opening for the airbag, through the opening for the airbag of the instrument panel, to fix the airbag unit to the vehicle body, the air bag grid to the opening for the airbag of the instrument panel. Attaching, closing the air bag grid to close the air bag opening provided in the instrument panel, and using the air bag grid closing means to hold the air bag grid in a closed state. Assembly method. 8. The air bag lid closing means is a member which does not project from the air bag grid when the air bag lid is opened as the air bag is deployed. 7. The method for assembling the airbag device according to 7. 9. The member, which does not project from the air bag grid when the air bag grid is opened as the airbag is deployed, is a string-like member that breaks under a predetermined load. The air bag grid is closed from the back side of the instrument panel by using, and the air bag grid is held in a closed state.