JPH08150888A - Air bag device - Google Patents

Abstract

PURPOSE: To provide a lightweight air bag device capable of preventing high heat from being transferred from an inflator to a module cover with a simple structure without requiring a special part at a low cost. CONSTITUTION: This air bag device is constituted of at least an air bag 1 protecting an occupant at the time of a collision, a base plate 3 fitted with an inflator 2 for inflating the air bag 1, and a module cover 4 fixed to the base plate 3 and storing the air bag 1 and the inflator 2. A hole or a slit 7 is bored between the inflator opening 11 of the flat plate section 3A of the base plate 3 and a module cover fixed section 5 erected from the flat plate section 3A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a module cover fixing portion of a base plate in an airbag device attached to a steering wheel of an automobile, which is an airbag device attached to a passenger seat, a door, a rear seat or a ceiling. It can also be applied to.

[0002]

2. Description of the Related Art Generally, an airbag in an airbag device is inflated by a high temperature and high pressure gas generated by an inflator. However, since the inflator is kept at a high temperature for a while after the inflation operation of the airbag as well as during the inflation operation of the airbag, the legs of the module cover are exposed to high heat through the base plate to which the inflator is attached. As a result, the legs of the module cover may be deformed or melted. Moreover, in recent years, thermoplastic resins or thermoplastic elastomers that can be easily molded have been adopted as the module cover, and the legs of the module cover of these thermoplastic resins, which have practically no problems in heat resistance, are used after the inflation operation of the airbag. After a while (about 5 minutes), it was found to be deformed or melted by residual heat. Usually, such deformation or melting in the leg portion of the module cover occurs at the time of airbag inflation operation, which has a significant effect on occupant protection performance, only by observing the form after airbag activation. After a while, it was not possible to distinguish whether the problem occurred, which caused a considerable problem in terms of product quality assurance. For this purpose,
As described in Japanese Patent No. 17 and Japanese Utility Model Laid-Open No. 6-35056, those devised to take measures for cutting off the transmission of high heat from the gas generator (inflator) to the module cover have been devised.

Referring to FIG. 11, the actual flat plate 6-1017 is used.
Explaining the conventional example described in the publication, the flange portion 22A of the gas generator 22 is inserted into an opening formed at the center of the flat plate portion of the base plate 23 so that the flange portion 22A of the gas generator 22 is formed.
The flat plate portion 3 is clamped and fixed together with the opening end of the airbag 21 by a ring-shaped retainer 38. On the other hand, a mounting piece portion 24A provided from a part of the cover body 24 is attached to the standing portion formed upright from the base plate 23, and the base plate 23 and the cover body 24 are fixed by the rivets 33 and the like. By interposing a heat insulator 20 such as resin or metal fiber having a low heat conductivity and a high airtightness between the flat plate portion of the base plate 23 and the flange portion 22A of the gas generator 22, the gas generator 22 From base plate 2
High heat is prevented from being transmitted to the mounting piece portion 24A of the cover body through 3.

[0004]

However, in the structure of the module cover fixing portion of the base plate in such a conventional air bag device, as described above, it is necessary to assemble the base plate and the inflator with the heat insulator interposed therebetween. As a result, the number of parts and weight increase, and the number of processes also increases, resulting in a decrease in work efficiency. As a result, the cost was increased, and the increased weight of the airbag device attached to the central portion of the steering wheel of the automobile increased the moment of inertia around the steering, which could lead to deterioration of the steering performance. . In the present invention, various problems in the conventional airbag device as described above are solved, high heat can be prevented from being transmitted from the inflator to the module cover by a simple structure without requiring special parts, and it is lightweight. To provide a low cost airbag device.

[0005]

For this reason, the present invention provides at least an airbag for protecting an occupant in a collision, a base plate for mounting an inflator for inflating the airbag, and the airbag fixed to the base plate. And a module cover for accommodating an inflator and the like, in which a hole or slit is provided between the inflator opening of the flat plate portion of the base plate and the module cover fixing portion provided upright from the flat plate portion. It is characterized by. Further, the present invention comprises at least an airbag for protecting an occupant in a collision, a base plate for mounting an inflator for inflating the airbag, and a module cover fixed to the base plate for accommodating the airbag and the inflator. In this airbag device, the standing side surface of the module cover fixing portion of the base plate is deformed, and a space is provided between the standing side surface and the leg portion of the module cover. Furthermore, the present invention is characterized in that a hole or a slit is provided in the deformed standing side surface.

[0006]

According to the present invention, at least the airbag 1 for protecting the occupant in the event of a collision, the base plate 3 to which the inflator 2 for inflating the airbag 1 is attached, and the airbag 1 and the inflator fixed to the base plate 3 are provided. In an airbag device including a module cover 4 for housing 2 and the like, an inflator opening 11 of a flat plate portion 3A of the base plate 3 and a flat plate portion 3 are provided.
By forming a hole or slit 7 between the module cover fixing portion 5 provided upright from A,
Not only when the airbag is inflated and deployed, but also when a high heat due to residual heat is transmitted from the inflator 2 to the module cover 4 for a while after the operation, the high heat is efficiently radiated from the holes or the slits 7. The heat transmitted to the leg portion 4A of the module cover through the module cover fixing portion 5 in 3 is reduced, and the module cover 4 is not deformed or melted. Therefore, there is no need for an extra member, and the module cover 4 is not deformed or melted not only when the airbag is inflated but also when the airbag is inflated and the residual heat is generated. It is possible to use a module cover made of a thermoplastic resin, which is easy to mold and is easy to mold. Moreover, the base plate is made lighter by the holes or slits formed in the base plate, and the leg portion of the module cover may be simply fixed to the base plate that has been separately drilled into the base plate. This will greatly contribute to cost reduction.

Further, the standing side surface 6 of the module cover fixing portion 5 in the base plate 3 is deformed so that a space S is formed between the standing side surface 6 and the leg portion 4A of the module cover.
Since the holes are not formed in the case where the space is provided, the space S between the upright side surface 6 of the module cover fixing portion 5 in the base plate 3 and the leg portion 4A of the module cover is maintained while maintaining the strength. The high heat transmitted by can be effectively dissipated. Moreover, in order to provide the space S, the module cover fixing portion 5 on the base plate 3 is provided.
When the standing side surface 6 is deformed, the deformed portion forms a reinforcing rib of the standing side surface 6, which contributes to the improvement of strength.

Further, if holes or slits 7 are formed in the deformed standing side surface 6, more efficient heat dissipation of the transferred heat can be realized, and holes or slits 7 are formed to reduce the weight. In the above, the strength is not lowered.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a sectional view showing an airbag device, and FIG. 2 shows a base plate. As is clear from the overall view of the airbag device in FIG. 1, the flat plate portion 3A of the metal base plate 3 is shown.
The inflator 2 is inserted into the inflator opening 11 at the center of the inflator 2, and the flange portion of the inflator 2 holds the opening edge of the flat plate portion 3A of the base plate 3 together with the opening end of the airbag 1 by the ring-shaped retainer 18. Both are tightened and fixed. On the other hand, the leg portion 4A of the module cover 4 made of a thermoplastic resin or an elastomer which is easy to mold is fixed to the module cover fixing portion 5 formed upright from the flat plate portion 3A of the base plate. In the present embodiment, the module cover fixing portion 5 causes the standing side surface 6 that is bent downward from the flat plate portion 3A of the base plate 3, that is, in the direction opposite to the occupant, to be folded back so as to surround the lower end portion of the leg portion 4A of the module cover and to be sandwiched. Further, a crimping metal fitting is formed by crimping the end portion folded back downward in the drawing so as to be locked in a groove formed on the outer surface of the leg portion 4A.
It should be noted that the module cover fixing portion 5 serving as the caulking portion is sufficient if the module cover leg portion 4A does not come out of the base plate 3, and the folded portion of the standing side surface 6 attaches the leg portion 4A to the module cover leg portion 4A. In addition to including a caulking state in which the module cover is bent to the extent of deformation, the module cover fixing portion 5 is in a state of being sandwiched between the module cover leg portion 4A without excess or deficiency, and a sandwiching state in which there is some margin between them. It includes. In the airbag device configured as described above, in this example, a large number of slits 7 are formed in the standing side surface 6 provided upright from the flat plate portion 3A of the base plate 3 and attached to the leg portion 4A of the module cover 4. It is installed and provided. As can be seen in FIG. 2, the inner side surface of the leg portion 4A of the module cover of the module cover fixing portion 5 is formed by bending the flat plate portion 3A of the base plate 3 from the four sides in the direction opposite to the occupant and further folding back. Slits 7 are formed in a row in a row on each standing side surface 6 in contact with each other at substantially equal intervals. Accordingly, not only when the airbag is inflated and deployed, but also when a high heat due to residual heat is transmitted from the inflator 2 to the module cover 4 for a while after the operation, the high heat is efficiently radiated from the slit 7, The heat transferred to the leg portions 4A of the module cover through the module cover fixing portion 5 of the base plate 3 is reduced, and the module cover 4 is not deformed or melted. Moreover, the weight of the base plate 3 is reduced by the large number of slits 7 formed in the standing side surface 6, and the leg portion 4A of the module cover may be simply fixed to the base plate 3 after the slit 7 is formed. This can greatly contribute to improving the productivity and reducing the cost of parts.

FIG. 3 is a cross-sectional view showing an airbag device according to a second embodiment of the present invention. The positions where the slits 7 for radiating heat are formed are the same as those in the first embodiment shown in FIG. However, in this example, as the module cover fixing portion 5 for fixing the leg portion 4A of the module cover 4 covering the airbag 1 to the base plate 3, the flat plate portion 3A of the base plate 3 is used.
The "rivet type" fixing portion is adopted in which the leg portion 4A of the module cover is attached to the standing side surface 6 raised from the peripheral edge portion of the module cover and pressed by the contact plate 12, and these are pierced and fixed by the rivet 13.

FIG. 4 is a side view of each base plate showing each modification of the first embodiment. In each of the examples shown here, the base plate 3 of the first embodiment is provided by being pierced on the standing side surface 6. In (A), a horizontally long rectangular slit 7 having a relatively large area is formed in the upper portion of the upright side surface 6, and is rapidly formed in the upper portion of the contact surface between the leg portion 4A of the module cover and the upright side surface 6 of the base plate. Has a heat dissipation effect. (B) has a large number of narrow slits 7 with a narrow width and a large height, and it is possible to radiate heat widely from the upper part to the lower part of the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate. Is.
(C) is a slightly smaller vertically elongated slit 7 formed in the upper portion of the standing side surface 6, and is a leg portion 4A of the module cover.
There is a slightly slower heat radiation effect at the upper part of the contact surface between the base plate and the upright side surface 6. (D) is small hole 7
Since A is provided in the upper portion of the standing side surface 6, there is a slow heat dissipation effect in the upper portion of the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, an inflator opening 11 of the flat plate portion 3A of the base plate 3 and a module cover fixing portion 5 provided upright from the flat plate portion 3A are shown. In between, when a large number of slits 7 (or holes) are formed in the vicinity of the peripheral edge of the flat plate portion 3A, the cut-and-raised pieces 10 are used as fins for enhancing the cooling effect. As a result, high heat from the inflator is effectively dissipated before reaching the standing side surface 6 that constitutes the fixing portion 5 of the module cover leg portion 4A. It is needless to say that forming the cut-and-raised pieces 10 when the slit 7 or the hole 7A is formed to obtain the radiation fin can be adopted in any of the other embodiments of the present invention.

FIG. 6 shows a fourth embodiment of the present invention, in which the upright side surface 6 of the module cover fixing portion 5 of the base plate 3 is deformed so that the upright side surface 6 and the leg portion 4A of the module cover are disposed. A space S is provided. In this example, the space S is provided by forming the inclined portion 8 in which the upper portion of the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate is isolated. As a result, the high heat transferred from the inflator 2 through the base plate 3 is the space S above the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate.
In, a rapid heat dissipation effect can be obtained.

FIG. 7 shows a fifth embodiment of the present invention. In this embodiment, the standing side surface 6 is located above the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate. When viewed from the side of the leg portion 4A, it is deformed into an arcuate cross section so as to form a concave portion,
And a space S penetrating in the width direction is provided between the leg portion 4A of the module cover and the leg portion 4A of the module cover. As a result, the high heat from the inflator 2 provides an effective heat dissipation effect in the space S above the contact surface between the leg portion 4A of the module cover and the upright side surface 6 of the base plate, and the deformed concave portion of the upright side surface 6 is effective. To form reinforcing ribs,
It contributes to strength improvement.

FIG. 8 shows a sixth embodiment of the present invention. In this embodiment, like the fifth embodiment, the upper part of the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate is shown. The leg portion 4A of the module cover so as to form the communication passage space S penetrating in the zigzag shape in the lateral direction.
The communication passage rib 9A is provided so as to project in the direction away from (right side in the drawing). As a result, an effective heat dissipation effect can be obtained in the space S above the contact surface between the leg portion 4A of the module cover and the upright side surface 6 of the base plate, and the zigzag communication passage rib 9A is resistant in both vertical and horizontal directions. Will be formed, and the strength will be further improved.

FIG. 9 shows a seventh embodiment of the present invention. In this embodiment, a horizontally elongated slit 7 is formed in a recess 9 provided in the standing side surface 6 of the base plate 3 in the fifth embodiment of FIG. Is drilled. As a result, the high heat from the inflator 2 causes the space S above the contact surface between the leg portion 4A of the module cover and the upright side surface 6 of the base plate.
Further, the slit 7 provides a more effective heat dissipation effect, and the deformed concave portion 9 forms the reinforcing rib of the standing side surface 6, so that there is no reduction in strength due to the slit drilling.

FIG. 10 shows an eighth embodiment of the present invention. This embodiment is above the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate in the fourth embodiment of FIG. A space S is provided by forming a slanted portion 8 whose parts are separated from each other, and a large number of slits 7 are formed in the slanted portion 8. Figure 10
In FIG. 10A, a number of slightly smaller vertically elongated slits are provided as the slit 7, and in FIG.
A large number of triangular slits 7 are formed in a zigzag pattern. In (A), there is a slightly slower heat dissipation effect in the upper space S of the contact surface between the leg portion 4A of the module cover and the standing side surface 6 of the base plate. In (B),
Since a large number of triangular slits 7 are formed in a zigzag pattern, there is a portion overlapping the slits in the width direction, and cooling is more effectively performed.

The inventors conducted an airbag deployment test, and in the conventional airbag device, 5 to 10 after deployment.
It was confirmed that the module cover of the thermoplastic elastomer melted in a minute, and a part of the base plate became extremely hot for a long time. Thereafter, when the airbag apparatus according to the present invention was tested by the same method, no melting of the module cover was observed, and in any type of example, the temperature at the same point was about 20 ° C. A decline was recorded.

Although the respective embodiments of the present invention have been described above, the shapes of the slits or holes, the positions of the holes or holes, the shape of the inclined portions for forming the spaces S, and the shapes of the slits or holes are within the scope of the spirit of the present invention. It goes without saying that the shape of the recess, the shape of the communication passage rib, the shape of the module cover fixing portion in the base plate, the fixing form of the base plate and the module cover leg portion, and the like can be appropriately adopted.

[0020]

As described above in detail, in the present invention, a hole or slit is formed between the inflator opening of the flat plate portion of the base plate and the module cover fixing portion provided upright from the flat plate portion. As a result, not only when the airbag is inflated and deployed, but also when high heat due to residual heat is transmitted from the inflator to the module cover for a while after the operation, the high heat is efficiently dissipated from the holes or slits. The heat transmitted to the leg portions of the module cover through the module cover fixing portion in is reduced, and the module cover is not deformed or melted. Therefore, without requiring an extra member, there is no fear that the module cover will be deformed or melted not only when the airbag is inflated but also by the residual heat after the inflation operation. It is possible to use a thermoplastic resin module cover that is easy to mold without any worry. Moreover, the base plate is lightened by the holes or slits formed in the base plate,
Since it is only necessary to fix the legs of the module cover to the base plate that has been separately drilled into the base plate,
This can greatly contribute to improvement of workability and reduction of parts cost. In addition, when the standing side surface of the module cover fixing portion in the base plate is deformed to provide a space between the standing side surface and the leg portion of the module cover, holes or the like are not formed. The high heat transmitted by the space between the upright side surface of the module cover fixing portion of the base plate and the leg portion of the module cover can be effectively dissipated while holding the above. Moreover, when the standing side surface of the module cover fixing portion of the base plate is deformed to provide the space, the deforming portion forms a reinforcing rib of the standing side surface,
It contributes to strength improvement. Further, if holes or slits are formed in the deformed standing side surface, more efficient heat dissipation of the transferred heat can be realized, and holes or slits are formed to reduce the weight and reduce the strength. Never invite. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an airbag device according to a first embodiment of the present invention.

FIG. 2 is a view showing a base plate according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing an airbag device according to a second embodiment of the present invention.

FIG. 4 is a side view of each base plate showing a modification of the first embodiment of the present invention.

FIG. 5 is a side view of a base plate according to a third embodiment of the present invention.

FIG. 6 is a side view of a base plate according to a fourth embodiment of the present invention.

FIG. 7 is a side view of a base plate according to a fifth embodiment of the present invention.

FIG. 8 is a side view of a base plate according to a sixth embodiment of the present invention.

FIG. 9 is a side view of a base plate according to a seventh embodiment of the present invention.

FIG. 10 is a side view of a base plate according to an eighth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a conventional airbag device.

[Explanation of symbols]

 1 Airbag 2 Inflator 3 Base plate 3A Flat plate part 4 Module cover 4A Leg part 5 Module cover fixing part 6 Standing side surface 7 Slit 7A hole 8 Inclined part 9 Recessed part 10 Cut and raised piece (fin) 11 Inflator opening 12 Abutting plate 13 Rivet 18 retainer

Claims (3)

[Claims] 1. An airbag for protecting an occupant at the time of a collision, a base plate for mounting an inflator for inflating the airbag, and a module cover fixed to the base plate for accommodating the airbag, the inflator and the like. In the airbag device, the airbag device is characterized in that a hole or a slit is provided between an inflator opening of the flat plate portion of the base plate and a module cover fixing portion provided upright from the flat plate portion. 2. An airbag for protecting an occupant at the time of a collision, a base plate for mounting an inflator for inflating the airbag, and a module cover fixed to the base plate for accommodating the airbag, the inflator and the like. The airbag device according to claim 1, wherein the standing side surface of the module cover fixing portion of the base plate is deformed, and a space is provided between the standing side surface and the leg portion of the module cover. 3. The airbag device according to claim 2, wherein a hole or a slit is provided in the deformed standing side surface.