JPH0752738A - Coupling structure of base plate and air bag cover - Google Patents

Abstract

PURPOSE:To dispense with a rivet and suchlike in simplifying a clamping means in terms of structure by forming each U-shaped fitting part in an end edge of a base plate made of high rigid metal material, while installing a rising engaged piece in the opposed wall surface, and setting up the connecting engaged hole in the rising wall of an air bag cover. CONSTITUTION:Plural fitting part fitting and pinching a rising wall part 14a of an almost U-shaped sectional air bag cover 14 are installed in each side wall 12a of four peripheral edge parts of a base plate 12. Each rising engaging piece 13b is formed in its opposed pinching piece 13a. In addition, an engaging hole 14b, where this rising engaging piece 13b is engaged, is formed in the rising wall part 14a of the air bag cover 14. When the base plate 12 and the air bag cover 14 are fitted with each other, the side wall 12a of the base plate 12 is thrust in an inner surface of the rising wall parts 14a of the air bag cover 14, and the rising engaging pieces 13b of the pinching part 13a are pinched and pressed from an outer surface by a pinch-pressing means, thereby engaging and clamping it to the engaging hole 14b of the rising wall part 14a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base plate and an air bag in an air bag device which is installed in front of a passenger seat of an automobile and absorbs the impact of an occupant by instantaneously expanding and expanding when a strong impact is applied to the vehicle. More particularly, the present invention relates to a structure for connecting a base plate and an air bag cover, which has a simple structure, can be easily assembled and can be firmly connected, and can be automated.

[0002]

2. Description of the Related Art In recent years, in order to ensure the safety of passengers,
In addition to the conventional seat belt device, when a large shock is applied to the vehicle, the shock is sensed and gas is introduced into the air bag to instantly inflate it into a balloon shape, which cushions the upper body of the occupant. BACKGROUND ART An air bag device has been put into practical use, which supports the air bag device to significantly reduce the impact force applied to the human body.

As shown in FIG. 8, this type of air bag device includes a metal base plate 2 for air-tightly supporting an air bag 1 made of nylon cloth or the like folded into an appropriate size at the peripheral edge of the opening. An air bag module 5 that accommodates the air bag 1 and has an air bag cover 4 made of a soft synthetic resin in which a peripheral standing wall portion 4a is externally fitted to the peripheral side wall portion 2a of the base plate 2 and fixed by rivets or the like. I have it. An inflator (gas generator) 6 is further attached to the opening of the airbag module 5, and is attached to a boss of a steering wheel in front of a passenger seat.

The airbag 1 is made of nylon cloth or the like. For example, when a vehicle collides, the inflator 6 is ignited in response to a signal from a sensor that detects the impact, and gas that burns rapidly is the same. The air bag 1 is released inside and instantly inflates. The airbag cover 4 is configured such that a part of the airbag cover 4 is ruptured when the airbag 1 is inflated and can be deployed. When the airbag device operates as described above, the airbag cover 4 is inflated by the inflation pressure of the airbag 1. The airbag 1 is ruptured and deployed, and the airbag 1 is expanded from the ruptured opening so that the airbag 1 can be inflated outward and greatly inflated.

The airbag module 5 described above is generally attached to a steering wheel or the like through the following assembling process. That is, after the airbag 1 is airtightly attached to the periphery of the opening of the base plate 2 and the airbag 1 is compactly folded,
The airbag cover 4 is attached to the base plate 2 so as to accommodate the. Installation of this airbag cover 4
In order to fix the positional relationship between the peripheral side wall 2a and the peripheral standing wall 4a after fitting the peripheral side wall 2a of the base plate 2 outside while slightly expanding the peripheral standing wall 4a of the cover 4 outward. Temporarily fixed by temporary fixing means. After that, the base plate 2 and the airbag cover 4 are firmly fixed and integrated with each other by rivets or the like via the contact plate 7. Next, the inflator 6 is attached to the base plate 2 by an appropriate means to form a module 5, and the base plate 2 of the module 5 is attached to a steering wheel (not shown).

Here, when the air bag cover 4 is fitted on the base plate 2 and attached, the reason why they are temporarily fixed and then fixed by rivets is that the air bag 1 attached to the base plate 2 in a folded state.
However, since the airbag cover 4 is pushed up from the inside, the positional relationship between the base plate 2 and the airbag cover 4 is likely to fluctuate, and this can be prevented so that work such as riveting can be performed accurately and reliably.

Conventionally, many improvements have been made for that purpose, but one example thereof is a connecting structure of an air bag cover and a base plate disclosed in Japanese Utility Model Laid-Open No. 4-115968. FIG. 8 shows the connection structure,
According to the figure, one of the airbag cover 4 and the base plate 2 projects toward the other member on or near a line connecting a plurality of fixing parts such as rivets between the airbag cover 4 and the base plate 2. It has an engaging means composed of a protrusion (4b) provided and an engaging portion (2c) provided on the other member that engages with the protrusion (4b). When the airbag cover 4 is externally fitted and attached to the base plate 2, a pad plate 7 is usually used in addition to the engaging means as in the conventional case, and the base plate 2, the airbag cover 4 and the pad plate 7 are combined. Once the person is temporarily fixed, the base plate 2 and the airbag cover 4 are firmly connected and fixed by rivets or the like.

[0008]

However, in the structure for connecting the airbag cover and the base plate disclosed in the above publication, the protrusions are made of a metal material when the assembly process is automated and press molding is taken into consideration. It is desirable that it is not formed on the base plate, but is formed on the airbag cover. Therefore, generally, an engaging hole or a concave portion is formed as an engaging means of the base plate, and a projection engaging with the engaging means is formed at a corresponding inner surface position of the airbag cover.

Furthermore, the connection between the air bag cover and the base plate disclosed in the above publication is often done manually by an operator, and the number of assembling steps of the air bag device is often large. And poor productivity. In addition, since a large number of rivets are used for full-scale fixing, the number of parts increases, leading to higher costs.

The present invention has been made in view of the above circumstances, and an object thereof is to adopt a simple mechanism as a fixing means for a base plate and an air bag cover and to simplify the step of connecting and fixing the same. Of the airbag cover and the base plate, which can easily support automation of the above, and which does not require fixing means such as rivets and has a strong fixing function, and can secure a large counter force against the deploying force of the cover. An object is to provide a connection structure and a connection method thereof.

[0011]

That is, the above object of the present invention is a connecting structure for pressing the peripheral side wall portion of the base plate along the inner wall surface of the peripheral standing wall portion of the airbag cover and connecting and fixing the both. The base plate is made of a highly rigid metal material, and a substantially U-shaped fitting portion is formed at the edge of the side wall portion. A deformable cut-and-raised engaging piece is provided, and a vertical wall portion of the airbag cover is provided with an engaging hole into which the cut-and-raised engaging piece of the fitting portion is engaged at the time of connection. This is achieved by the connecting structure of the base plate and the airbag cover.

Further, the above object of the present invention is to have a sandwiching piece which has a substantially U-shaped cross-sectional shape, and which sandwiches the side wall portion of the base plate and the standing wall portion of the airbag cover in an overlapping state in an externally fitted state. The opposing sandwiching piece is provided with a connector having a cut-and-raised engaging piece whose tip is plastically deformed by a sandwiching pressure, and the side wall portion of the base plate and the standing wall portion of the airbag cover are externally fitted and sandwiched by the connector. The present invention is also achieved by a connecting structure of a base plate and an airbag cover, characterized in that engaging holes for respectively cutting and raising the engaging pieces are formed.

In order to connect and fix the base plate and the airbag cover with these connecting structures, the peripheral side wall of the base plate is pushed by a predetermined amount along the inner wall surface of the peripheral standing wall of the airbag cover to form a substantially U-shape. After the fitting by the fitting part having a cross section or the fitting by the connecting tool is completed, the opposing cut-and-raised engaging pieces are pressed and deformed plastically in the direction in which the tips approach each other, and the cut-and-raised engaging pieces correspond. It is achieved by engaging and fixing in the engaging hole. In addition to the usual steel material, spring steel or the like can be used for the material of the base plate and the connecting tool applied to the present invention.

[0014]

When the base plate has a fitting portion having a U-shaped cross section at the end of the side wall portion, when the base plate and the airbag cover are fitted and fixed, the base plate made of a normal steel plate has a bending rigidity. Is large and the elasticity is poor, so when the standing wall of the airbag cover made of a synthetic resin material having an elastic structure is simply fitted into the U-shaped fitting portion, the fitting portion is cut and raised. Not only is the piece obstructed and the fitting is not smoothed, but also the cut-and-raised engaging piece may slide strongly and damage the standing wall.
Therefore, the cut-and-raised engaging piece and the sandwiching piece are placed on the same plane until the base plate and the airbag cover are connected as described above.

In this state, the side wall of the base plate is pushed along the inner surface of the standing wall of the air bag cover so that the air bag is housed inside the air bag cover. At the time of this pushing, the standing wall of the airbag cover is cut and raised, and is smoothly fitted into the fitting portion having the inverted U-shaped cross section formed on the side wall without being obstructed by the engaging piece. Then, the cut-and-raised engaging pieces facing each other of the sandwiching portion are pressed by an appropriate pressing means from the outer surface to be plastically deformed, and the cut-and-raised engaging pieces are attached to the standing wall of the airbag cover. It is fixed to the hole by almost penetrating.

According to the connection structure of the present invention obtained in this way, the engagement between the cut-and-raised engagement piece of the base plate and the engagement hole of the airbag cover is as strong as the connection by the rivet. In addition to this, since the airbag cover is clamped by the clamping portion of the base plate, the drag force when the airbag cover is ruptured and deployed by the internal pressure generated when the airbag is inflated with gas is sufficiently retained.

Further, the step of connecting the base plate and the air bag cover is not only required to reduce the number of parts such as a large number of rivets but also requires two steps of the step of pushing the base plate against the air bag cover and the step of pinching. This makes it easy to realize the automatic assembly of the airbag device and also leads to cost reduction.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A connecting structure for a base plate and an airbag cover according to the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing an example of a connecting structure of an airbag cover and a base plate, which is a typical embodiment of the present invention.

The airbag module 15 according to this embodiment.
Is a base plate 12, an airbag cover 14 that also serves as a center pad of a steering wheel, an airbag 11 that is folded and accommodated in a storage space formed by the base plate 12 and the airbag cover 14, and an inflator 16 that is also the same. And is fixed to the boss portion 17 of the steering wheel via a fixing bracket (not shown) as in the conventional case.

As shown in FIG. 1, the base plate 12
Consists of a rectangular metal box having a circular opening 12c at the center of the bottom surface, and supports the opening end of the airbag 11 that is stored in a folded state at the peripheral edge of the circular opening 12c. Inflator 1 after attaching the bag
The flange portion 16a of 6 is supported by the circular opening 12c. Then, in the four peripheral portions of the base plate 12,
Each has a side wall 12a which is one of the features of the first invention. The base plate 12 having such a configuration is
It is manufactured by pressing an ordinary steel plate.

The point to be noted in this embodiment is that the upper wall of the side wall 12a of the base plate 12 is fitted with the standing wall portion 14a of the airbag cover 14 having a plurality of substantially U-shaped cross sections at predetermined intervals. The fitting portion 13 for holding and sandwiching is formed so as to project, and the opposing sandwiching piece 13a has a structure shown in FIG.
Cut-and-raised engaging piece 13 having a shape as illustrated in FIG.
The point b is formed by press working. The shape of the cut-and-raised engaging piece 13b is appropriately determined,
For example, as shown in FIG. 2, the tips are formed in a hook shape and intersect each other, or as shown in FIG. 3, they are formed as simple rectangular pieces and intersect each other. These cut-and-raised engaging pieces 13b are on the same plane as the sandwiching pieces 13a as shown in FIG. 2, for example, until the base plate 12 and the airbag cover 14 are connected.

The one airbag cover 14 is made of a synthetic resin material such as thermoplastic elastomer and has a box shape having standing walls 14a at four peripheral edges of a substantially rectangular surface portion. The standing wall 14a is thicker than other portions and has a predetermined rigidity, and the standing wall 1 of the airbag cover 14 fitted to the fitting portion 13 of the base plate 12 is provided.
4a is located at a position facing the cut-and-raised engaging piece 13b when the upright wall 14a is completely fitted to the fitting portion 13,
An engaging hole 14b is formed in which the cut-and-raised engaging piece 13b is engaged. The engagement hole 14b is preferably rectangular as shown in FIG.

Base plate 1 constructed as described above
When fitting and fixing the airbag 2 and the airbag cover 14, the base plate 12 made of a normal steel plate has large bending rigidity and poor elasticity, so that the fitting portion 13 bent in a U shape is provided with an elastic structure. When the upright wall 14a of the airbag cover 14 made of the synthetic resin material is simply fitted, not only the cut-and-raised engaging piece 13b of the fitting portion 13 interferes with the fitting, but the fitting is not smooth, and The raised engaging piece 13b may come into strong sliding contact with the standing wall 14a and damage it. Therefore, the cut-and-raised engaging piece 13b and the sandwiching piece 13a are on the same plane until the base plate 12 and the airbag cover 14 are connected as described above.

In this state, the airbag 11 is housed inside the airbag cover 14, so that the side wall 12a of the base plate 12 and the standing wall 14a of the airbag cover 14 are accommodated.
Push along the inner surface of. At the time of this pushing, the standing wall 14a of the airbag cover 14 is smoothly fitted into the fitting portion 13 having the inverted U-shaped cross section formed on the side wall 12a without being cut and raised and hindered by the engaging piece 13b. Next, the cut-and-raised engaging pieces 13b facing each other are clamped from the outer surface by a not-shown pressing means, and are plastically deformed so as to approach each other, and the cut-and-raised engaging pieces 13b are air-pressed. The bag cover 14 is engaged and fixed in the engaging hole 14b formed in the standing wall 14a.

According to the connection structure of the present invention thus obtained, the cut-and-raised engaging piece 13b of the base plate 12 and the engaging hole 14b of the airbag cover 14 are firmly attached to each other as if they were joined by rivets. In addition to this, since the airbag cover 14 is clamped by the clamping portion 13a of the base plate 12 in addition to this, the drag force when the airbag cover ruptures and deploys due to the internal pressure generated during gas inflation of the airbag 11 is exerted. Holds well.

Also, in the step of connecting the base plate 12 and the airbag cover 14, the number of parts such as a large number of rivets is reduced, and the step of pushing the base plate 12 into the airbag cover 14 and the step of pinching with a hammer or the like are performed. Since only two steps are required, it becomes easy to realize the automatic assembly of the airbag device and the cost can be reduced.

FIG. 4 shows a modification of the connecting structure of the present invention. As is clear from a comparison between FIG. 4 and FIG. 2, the starting ends of the cut and raised engaging pieces 13b are upside down.
Further, the tip of the sandwiching piece 13a is bent outward so that the standing wall 14a of the airbag cover 14 can be easily introduced into the fitting portion 13. FIG. 5 shows a deformation mode when the cut-and-raised engaging piece 13b is deformed by pinching, and FIG.
Shows an example of pinching and deforming the inside of the engaging hole 14b of the airbag cover 14 until the tips of the opposite cut-and-raised engaging pieces 13b are butted against each other, and FIG. An example is shown in which the pieces 13b are bent substantially at right angles until they are in a superposed state, and in these examples, it is not necessary to cut and raise the facing cut-and-raised engaging pieces 13b in a crossed state as shown in FIG. Further, FIG. 7C shows an example in which the facing cut-and-raised engaging pieces 13b are bent inwardly in a V shape, and FIG. 7D shows the facing cut-and-raised engaging pieces 13b in an intersecting state. This is an example of deforming by pinching and can be adopted when deforming the cut-and-raised engaging piece 13b shown in FIGS. 1 and 2.

FIG. 6 shows a typical embodiment of the second invention. According to the invention, a dedicated connector 20 is used to connect the base cover 12 and the airbag cover 14. The connector 20 is made of a normal steel plate having high rigidity or a spring steel plate having elasticity, and has a substantially concave cross-sectional shape. The side wall 12 a of the base plate 12 and the standing wall portion 14 a of the airbag cover 14 are connected to each other. A pair of front and rear clamping pieces 21 for external fitting and sandwiching in a superposed state are provided, and the opposing clamping pieces 21a are cut-and-raised engaging pieces that plastically deform their tips in the approaching direction by the clamping pressure as in the first invention. 21b. The connecting member 2 is attached to the side wall 12a of the one base plate 12 and the standing wall 14a of the airbag cover 14.
The engaging holes 12 into which the cut-and-raised engaging pieces 21b that are deformed by pinching are engaged and fixed in a penetrating state after 0 is fitted.
Only b and 14b are formed respectively, and no other special processing is performed. Also, in the second invention, the cut-and-raised engaging piece 21b and the sandwiching piece 21a are on the same plane until the connector 20 is fitted to the side wall 12a and the standing wall 14a, as in the first invention. .

In this state, the side wall 12 of the base plate 12
a is pushed along the inner surface of the standing wall 14a of the airbag cover 14 to bring the side wall 12a and the standing wall 14a into a superposed state. In the pushing operation at this time, the connector 20 is smoothly fitted into the side wall 12a and the standing wall 14a from the outside without being hindered by the cut and raised engaging pieces 21b of the sandwiching pieces 21a facing each other. Next, using a clamping means such as a hammer (not shown), the opposing cut-and-raised engaging pieces 21b of the sandwiching pieces 21a are pressed from the outside, and are plastically deformed in a direction in which they approach each other. Put the piece 13b on the airbag cover 1
The fixing holes 14b formed in the vertical wall 14a of FIG.

Also according to the connecting structure of the second invention thus obtained, the cut-and-raised engaging piece 21b of the connecting tool 20 and the engaging holes 12b and 14b formed in the base plate 12 and the airbag cover 14 can be engaged with each other. Since it becomes as strong as the connection by the rivet, the internal pressure generated when the airbag 11 inflates the gas sufficiently holds the drag force when the airbag cover ruptures and deploys, and prevents the airbag 11 from being fixed again by the rivet or the like. Make it unnecessary.

FIG. 7 shows another modification of the cut-and-raised engaging pieces 13b and 21b of the first and second inventions. As shown in the drawing, both configurations have the same form in both inventions. A part of each sandwiching piece 13a, 21a is cut and raised in a substantially U-shape and bent at a right angle so that the base plate 12 and the airbag cover 14 are separated from each other. It is firmly connected. As described above, the cut-and-raised engaging pieces 13b and 14b described above can be variously modified.

[0032]

As is apparent from the above description, according to the connecting structure of the base plate and the airbag cover in the airbag apparatus of the present invention, it is formed on the side wall portion of the base plate as a fixing means for the base plate and the airbag cover. The cut-and-raised engaging pieces formed on the respective holding pieces of the U-shaped fitting portion or the dedicated connecting tool having the U-shaped cross section are directed toward the inside of the engaging hole of the other side at the time of connection. Since it is deformed by pinching and fixed by engagement, not only the connecting process is shortened and automation can be easily coped with, but also the fixing means such as rivets is eliminated to reduce the number of parts, resulting in significant cost reduction. It is possible to reduce the number of pieces, and since the cut-and-raised engaging piece is attached to the engaging hole of the other side in a substantially penetrating state, a strong fixing function is exhibited. Even repulsive force due to the air bag acts on the base plate, it is possible to firmly consolidated in the number of small steps without going through the temporary fixing process, the productivity is significantly improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an airbag device showing a connection structure example of a base plate and a cover, which is a typical embodiment of the first invention.

FIG. 2 is an exploded perspective view showing an enlarged example of the structure of a fitting portion of the base plate.

FIG. 3 is a perspective view showing an enlarged example of another fitting structure of the base plate.

FIG. 4 is an enlarged perspective view showing still another fitting structure example of the base plate.

FIG. 5 is an explanatory view showing a modified mode of the cut-and-raised engaging piece at the time of connection.

FIG. 6 is a perspective view showing a connection structure example of a base plate and a cover, which is a typical embodiment of the second invention.

FIG. 7 is a cross-sectional view showing a modified embodiment of another cut-and-raised engaging piece in the first and second inventions.

FIG. 8 is an exploded perspective view showing an example of a conventional airbag device.

[Explanation of symbols]

 11 Airbag 12 Base plate 12a Side wall 12c Opening 13 Fitting 13a Holding piece 13b Cut and raised engaging piece 14,114 Airbag cover 14a, 114a Standing wall 14b Attachment hole 15 Airbag module 16 Inflator 16a Flange 17 Boss 20 Connecting tool 21, 21a Clamping piece 21b Cut-and-raised engaging piece

Claims (2)

[Claims] 1. A connection structure for pressing a peripheral side wall portion of a base plate along an inner wall surface of a peripheral standing wall portion of an airbag cover to connect and fix the both, wherein the base plate is made of a highly rigid metal material, A substantially U-shaped fitting portion is formed at an end edge of the side wall portion, and a cut-and-raised engaging piece for plastically deforming a tip end by pressing is provided on an opposing wall surface of the fitting portion, the airbag. A structure for connecting a base plate and an airbag cover, wherein the standing wall portion of the cover has an engaging hole into which the cut-and-raised engaging piece of the fitting portion is engaged at the time of connection. 2. A connecting structure for fitting and fixing a peripheral side wall portion of a base plate along an inner wall surface of a peripheral standing wall portion of an airbag cover, the connecting structure having a substantially U-shaped cross-section. The side wall portion and the standing wall portion of the airbag cover are provided with a sandwiching piece for externally sandwiching and sandwiching them, and the opposing sandwiching piece is provided with a connector having a cut-and-raised engaging piece for plastically deforming the tip by pressing. The side wall portion of the base plate and the standing wall portion of the airbag cover are formed with engaging holes for engaging the cut-and-raised engaging pieces when the fitting is held by the connecting tool. Base plate and airbag cover connection structure.