JPH10273006A - Horn switch mechanism of steering wheel with air bage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a horn switch without deterioration of the operability and of a horn and also improve the reliability of the horn when an air bag is being inflated. SOLUTION: An air bag device 2 is installed below the pad 1 of a steering wheel W. A membrane switch 11 is provided between an air bag 5, which is folded up, and the pad 11, and this membrane switch 11 is placed on and fixed to a switch plate 13. A ring retainer 6 constituting the air bag device 2 is formed with a tower-like extension retainer 21. In the lower face of the switch plate 13, a locking claw 22 extending downward is formed integrally with the lower face. The retainer 21 is held by the locking claw 22 together with the center section of the air bag 5. In such constitution, the switch plate 13 is locked by the extension retainer 21. While the air bag is being inflated, the locking state is released with ease.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel having an airbag device, and more particularly, to a horn switch mechanism of a steering wheel with an airbag having a membrane switch between a pad and an airbag device. It is.

[0002]

2. Description of the Related Art Conventionally, a steering wheel provided with an airbag device has been known. The airbag device includes a bag holder, an inflator, an airbag, a ring retainer, and the like, and is fixed to a core of a steering wheel. When a predetermined acceleration is applied to the vehicle, nitrogen gas is generated from the inflator,
The airbag breaks the steering wheel pad and inflates and expands.

In a steering wheel provided with an airbag device as described above, a membrane switch is provided between a folded airbag and a pad. The membrane switch is mounted and fixed on a resin switch plate provided so as to cover the airbag device. Further, the membrane switch has a pair of thin plates forming a part of the horn switch circuit. When the thin plates contact each other by pressing the pad, the horn sounds based on the contact.

[0004]

However, in the above prior art, the membrane switch receives a force (reaction force) for inflating the airbag which has been folded and compressed to some extent, and the thin plates contact each other. This may cause the horn to sound without a pressing operation. In this case, it is conceivable to provide a band for firmly holding the airbag. However, in this case, it is necessary to separately provide a band and use the band to firmly hold the airbag. Therefore, problems such as an increase in the number of parts and a decrease in workability at the time of assembly occur.

It is also conceivable that a part of the reaction force is regulated by making the switch plate very rigid. In this case, since the deformation of the base supporting the membrane switch is suppressed, there is also an advantage that the operation load during horn sounding can be easily set to a desired load.

However, if the rigidity of the switch plate is unnecessarily increased in this manner, there is a possibility that the stability when the airbag is inflated may be impaired. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a horn switch mechanism for a steering wheel including an airbag device, without deteriorating the operability of the horn. It is an object of the present invention to provide a horn switch mechanism of a steering wheel with an airbag which can improve the reliability of the steering wheel with an airbag and can also improve the reliability when the airbag is inflated.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a pad provided substantially at the center of a steering wheel, and a bag-shaped air bag located below the pad. A bag, an inflator that generates gas when a predetermined acceleration is applied, a bag holder for fixing the airbag and the inflator to a metal core of a steering wheel, and an opening edge portion of the airbag is fixed to the bag holder. An airbag device having a ring retainer for performing the operation, a switch plate provided below the pad to cover the airbag device, and the switch plate provided at a predetermined distance from the lower surface of the pad. An air bar mounted and fixed on the top and having a membrane switch for sounding the horn by pressing A horn switch mechanism for a steering wheel with a ring, wherein at least one of the ring retainer, the inflator and the bag holder has an extension, and at least one of the extension and the switch plate has an extension. On the other hand, the gist of the invention is to provide a locking mechanism for locking the switch plate together with a part of the airbag.

According to a second aspect of the present invention, in the horn switch mechanism for a steering wheel with an airbag according to the first aspect, the extension portion connects two ends of the ring retainer. Its gist is that it is composed.

According to a third aspect of the present invention, in the horn switch mechanism for a steering wheel with an airbag according to the first or second aspect, the locking mechanism is provided on a lower surface of the switch plate. The gist is to include a locking claw for gripping the extension.

In addition, according to the invention described in claim 4, in the horn switch mechanism for a steering wheel with an airbag according to any one of claims 1 to 3, the locking mechanism is formed in the extension. The gist of the invention is to include a through hole and a projection provided on the lower surface of the switch plate and engaged with the through hole.

According to a fifth aspect of the present invention, in the horn switch mechanism for a steering wheel with an airbag according to any one of the first to fourth aspects, the switch plate has a certainty when the airbag is inflated. The gist of the invention is that it is divided into a plurality of parts for the purpose, or has a mechanism that can be easily divided.

According to the first aspect of the present invention, when a predetermined acceleration is applied, gas is generated from the inflator, and the bag-shaped airbag is inflated. Due to this inflation, the pad provided substantially at the center of the tearing wheel is deployed, and the airbag further inflates.

A membrane switch is mounted and fixed on a switch plate provided below the pad so as to cover the airbag device, and the horn sounds when the membrane switch is pressed.

According to the present invention, in the airbag device, at least one of the ring retainer, the inflator and the bag holder is provided with an extension. The switch plate is locked to the extension together with a part of the airbag by a locking mechanism provided on at least one of the extension and the switch plate.

Accordingly, even if the switch plate receives a reaction force from the airbag, the reaction force is received by the locking mechanism, and the switch plate and, consequently, the membrane switch mounted and fixed thereon are deformed. I won't. For this reason, the horn does not end up except when the horn is operated. Further, since the switch plate and the like are not deformed, the initially set operation load can be maintained.

Further, since the above operation is achieved, it is not necessary to increase the rigidity of the switch plate. Therefore, when the airbag is inflated, the switch plate will also be split or expanded accordingly.
Stability during inflation of the airbag is also ensured.

According to a second aspect of the present invention, in addition to the operation of the first aspect, the extension portion is formed by connecting two ends of the ring retainer. I have. For this reason, an extension part can be constituted easily and reliably.

In addition, according to the third aspect of the present invention,
In addition to the effects of the first and second aspects of the present invention, the locking mechanism includes a locking claw provided on the lower surface of the switch plate and gripping the extension. Therefore, the switch plate can be locked to the extension together with a part of the airbag only by the action of causing the extension claw on the lower surface of the switch plate to be gripped by the extension.

In addition, according to the fourth aspect of the present invention,
In addition to the functions of the invention according to claims 1 to 3, the locking mechanism is provided on a through hole formed in the extension portion, and a projection provided on a lower surface of the switch plate and engaged with the through hole. And Therefore, the switch plate can be locked to the extension together with a part of the airbag only by engaging the projection on the lower surface of the switch plate with the through hole formed in the extension.

According to a fifth aspect of the present invention, in addition to the functions of the first to fourth aspects, the switch plate is divided into a plurality of parts or is easily divided. Has a mechanism. Therefore, when the airbag is inflated, the locking state of the locking mechanism is released, and the switch plate is divided and separated. Therefore, when the airbag is inflated, the inflation is not hindered by the presence of the switch plate.

[0021]

As described above in detail, according to the horn switch mechanism of the steering wheel with an airbag of the present invention, the reliability of the horn switch can be improved without deteriorating the operability of the horn. In addition to this, there is an excellent effect that the reliability at the time of inflation of the airbag can be improved.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. Figure 1
As shown in FIG. 3, a pad 1 made of an elastic synthetic resin material such as polyurethane is provided substantially at the center of the steering wheel W. Below the pad 1, an airbag device 2 is provided. The airbag device 2 includes:
As is well known, a bag holder 3, an inflator 4, an airbag 5, a ring retainer 6, and the like are provided. The metal bag holder 3 is fixed to a metal core (not shown) of the steering wheel. At the opening of the bag holder 3, an inflator 4 in which a gas generating agent is stored is disposed. An airbag 5 made of cloth and a ring retainer 6 made of metal are attached to the upper surface of the bag holder 3 (or the inflator 4). More specifically, a plurality of legs 7 projecting downward are integrally formed on the ring retainer 6. These legs 7 are inserted into the through holes of the airbag 5, the bag holder 3 and the inflator 4, and the nut 8 is fastened to a screw portion of the leg 7 projecting from the lower side of the inflator 4. The inflator 4, the airbag 5 and the ring retainer 6 are attached and fixed to the bag holder 3.

When a predetermined acceleration is applied to the vehicle, nitrogen gas is generated from the inflator 4, and the airbag 5 breaks the pad 1 and expands and expands. The pad 1 has a flat surface H to facilitate the expansion of the pad 1 when the airbag 5 is inflated.
A letter-shaped notch 9 is formed.

In this embodiment, a membrane switch 11 is provided between the folded airbag 5 and the pad 1 as shown in FIGS. The membrane switch 11 is mounted and fixed on a switch plate 13 provided so as to cover the airbag device 2. The switch plate 13 is made of thermoplastic polyolefin, and is fixed to the bag holder 3 or the like.

The membrane switch 11 has a pair of thin plates (not shown) forming a part of a horn switch circuit. A large number of printing spacers (not shown) are formed on the pair of thin plates so as to secure a certain gap, so that the thin plates do not contact each other except during a pressing operation. When the thin plates contact each other by pressing the pad 1, the horn sounds based on the contact.

Next, a characteristic portion of the present embodiment will be described. As shown in FIGS. 1, 2, 5, the ring retainer 6 is formed with an extension retainer 21 as an extension extending to the highest position among the ring retainer 6, the inflator 4 and the bag holder 3. The extension retainer 21 is formed in a scalloped shape by connecting two opposite ends of the ring retainer 6 to each other. Further, both sides in the width direction of the extension retainer 21 are curved.

On the other hand, a groove 13a is formed in the switch plate 13 so as to correspond to the central notch 9. On the lower surface of the switch plate 13, locking claws 22 extending downward are integrally formed at predetermined intervals. Then, the extension retainer 21 is gripped by the retaining claw 22 together with the central portion (one piece of cloth) of the airbag 5, whereby the switch plate 13 is retained by the extension retainer 21. That is,
In the present embodiment, a locking mechanism is configured by the locking claw 22 and the extension retainer 21. However, the locking mechanism is configured so that the locked state can be easily released when the airbag 5 is inflated.

The membrane switch 11 includes:
A flat H-shaped slit 12 is formed corresponding to the notch 9. As an aside, the airbag 5 in the present embodiment is folded as follows. That is, as shown in the upper part of FIG. 4, the airbag 5 is first bent several times at the two edge portions while the opening is directed downward. next,
As shown in the middle part of FIG. 4, the airbag 5 has the remaining two edge portions bent several times in the direction opposite to the above. By being folded in this manner, as shown in the lower part of FIG. 4, a portion that is locked and held by the locking claw 22 together with the switch plate 13 with respect to the extended retainer 21 of the ring retainer 6 (in a dotted pattern in the drawing). (Portions shown).

Next, the operation and effect of this embodiment will be described. In this embodiment, when the pad 1 is pressed, the thin plates of the membrane switch 11 come into contact with each other. This causes the horn to sound. Here, an extended retainer 21 is formed on the ring retainer 6, and
The extension retainer 21 is gripped by the locking claw 22 provided on the lower surface of the switch plate 13 together with the central portion (one piece of cloth) of the airbag 5. The switch plate 13 is locked to the extension retainer 21 by the locking mechanism.

Therefore, even if the switch plate 13 receives the reaction force from the folded airbag 5, the reaction force is received by the above-mentioned locking mechanism, and the switch plate 13, and furthermore, is placed and fixed thereon. The deformed membrane switch 11 is not deformed. Therefore, the horn does not ring except during the operation of the horn. As a result, the reliability of the horn switch can be improved.

Further, since the switch plate 13 and the like are not deformed, the initially set operation load can be maintained. Therefore, horn operability is not degraded, and the reliability of the horn switch can be further improved.

Further, since the above-described effects are obtained, it is not necessary to increase the rigidity of the switch plate 13 unnecessarily. Therefore, as shown in FIG. 6, when the airbag 5 is inflated, the switch plate 13 is also easily expanded with the hinge plate as a center.
Therefore, stability at the time of inflation of the airbag 5 can also be secured.

In addition, in the present embodiment, the locking mechanism comprises a locking claw 22 or the like so as to easily release the locked state when the airbag 5 is inflated.
Therefore, the operation and effect that the above-described stability at the time of inflation of the airbag 5 can be ensured is more reliably achieved.

In addition, in the present embodiment, the extension retainer 21 is formed in the shape of a scoop by connecting two ends of the ring retainer 6 to each other. For this reason, the locking mechanism can be easily and reliably formed, and the above-described respective effects can be obtained.

According to the present embodiment, the locking claw 22 is provided on the lower surface of the switch plate 13 and
To hold the extension retainer 21. Therefore,
The locking mechanism can be configured only by causing the locking claw 22 to be gripped by the extension retainer 21, that is, only by fitting the switch plate 13. As a result, there is no trouble in assembling, and the workability can be dramatically improved. Further, since there is no need to provide a band as described in the related art, it is possible to reduce the cost without increasing the number of parts.

In addition, in this embodiment, the membrane switch 11 and the switch plate 13 are provided with the flat H-shaped slit 12 and the groove 13a corresponding to the notch 9. Therefore, the airbag 5
In the case of the expansion, the membrane switch 11 and the switch plate 13 do not hinder the expansion.

In addition, in this embodiment, both sides in the width direction of the extension retainer 21 are formed to be curved. For this reason, when a part of the airbag 5 is gripped by the locking claws 22, no damage is caused by both sides in the width direction of the extension retainer 21. As a result, more stable inflation of the airbag 5 can be secured.

In the present embodiment, a part of the airbag 5 is gripped so that the extension retainer 21 is sandwiched between the locking claws 22. For this reason, the airbag 5
As shown in FIG. 1, it is only necessary to bend not two-dimensionally but two-dimensionally. Therefore, wrinkles are hardly generated in the airbag 5, and the gripping state is also stable.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. However, in the present embodiment, the first
Since the embodiment and the basic configuration are the same, the same members are denoted by the same reference numerals and the description thereof will be omitted, and the following description will focus on the differences.

As shown in FIGS. 7 to 9, a ring-shaped extension retainer 31 as an extension is formed in the ring retainer 6 in a direction orthogonal to the extension retainer 21 of the first embodiment. ing. In this extension retainer 31,
Two through holes 32 and 33 are formed.

On the other hand, the switch plate 13 is composed of two divided pieces 13A and 13B in advance with a line corresponding to the central notch 9 as a boundary. Locking projections 34 and 35 extending downward are integrally formed on the lower surface of the switch plate 13. Then, the locking projections 34 and 35, together with the central portion (one piece of cloth) of the airbag 5, are provided with the through holes 32 and 3 of the extension retainer 31.
3 so that the switch plate 1
3 is locked to the extension retainer 31. That is, in the present embodiment, the locking mechanism is constituted by the locking projections 34 and 35 and the through holes 32 and 33 of the extension retainer 31. However, this locking mechanism is also configured such that the locking state can be easily released when the airbag 5 is inflated, that is, the locking projections 34 and 35 are easily removed from the through holes 32 and 33. I have.

In this embodiment, basically, the same operation and effect as those of the first embodiment can be obtained. That is, the switch plate 13 is locked to the extension retainer 31 by a locking mechanism constituted by the locking protrusions 34 and 35 and the through holes 32 and 33 of the extension retainer 31. Therefore, even if the switch plate 13 receives a reaction force from the folded airbag 5, the reaction force is received by the locking mechanism. Therefore, the horn does not ring except at the time of the horn operation, and the reliability of the horn switch can be improved.

Further, since the switch plate 13 and the like are not deformed, the operability of the horn is not deteriorated, and the reliability of the horn switch can be further improved.

Further, in this embodiment, when the airbag 5 is inflated, the locking state is easily released as shown in FIG.
Easily come out of the through holes 32 and 33. Therefore, stability at the time of inflation of the airbag 5 can be ensured.

In addition, as described above, the switch plate 1
3 can be locked and fixed, so that the switch plate 13 is previously divided into the divided pieces 13A and 13B as in the present embodiment.
Even if it comprises, the divided pieces 13A and 13B do not deform or move, and the operability of the horn does not deteriorate. By previously configuring the switch plate 13 with the divided pieces 13A and 13B, the switch plate 13 shown in FIG.
As shown at 0, when the airbag 5 is inflated, the locked state of the locking mechanism is released, and the switch plate 13 is quickly divided and separated. Therefore, when the airbag 5 is inflated, the switch plate 13 does not hinder the inflation, so that more stable inflation can be ensured.

It should be noted that the present invention is not limited to the above-described embodiments, but may be implemented as follows, with a part of the configuration being appropriately changed without departing from the spirit of the invention. (1) In the second embodiment, the switch plate 1
3 is composed of two divided pieces 13A and 13B,
It may be constituted by one or more divided pieces. Further, the groove 13a may be formed as in the first embodiment so as to be easily divided when the airbag 5 is inflated without being divided in advance. Further, a slit or the like may be formed in addition to the groove.

(2) In each of the above embodiments, the extension retainer 21 and the locking claw 22, and the through-hole 3 of the extension retainer 31
Although the locking mechanism is configured by the locking projections 34 and 35 and the locking projections 34 and 35, the locking mechanism may be configured by another structure (for example, a cantilever locking claw or the like).

(3) The number of the locking claws 22 and the locking projections 3
The numbers such as 4, 35 and the like are not limited to those in the above embodiment. (4) In each of the above embodiments, the extension retainers 21 and 31 of the ring retainer 6 are provided. However, the extension retainers 21 and 31 may be provided on at least one of the ring retainer 6, the inflator 4 and the bag holder 3. Further, the extension portion is not limited to a round shape like the extension retainers 21 and 31, and may have any other shape.

(5) In the above embodiment, the steering wheel W is embodied as a type having four spokes. However, the steering wheel W may be embodied as a type having two, three, or five or more spokes. Can also.

The technical idea which is not described in each claim of the claims and can be grasped from the above embodiment will be described below together with its effects. (A) The horn switch mechanism for a steering wheel with an airbag according to any one of claims 1 to 6,
The extension extends to the highest position among the ring retainer, the inflator and the bag holder.

With this configuration, the configuration of the locking mechanism can be simplified.

[Brief description of the drawings]

FIG. 1 is a diagram showing pads and the like for explaining a horn switch mechanism according to a first embodiment, and is a cross-sectional view taken along line JJ of FIG. 3;

FIG. 2 is a sectional view taken along line KK of FIG.

FIG. 3 is a plan view of a steering wheel.

FIG. 4 is a perspective view schematically showing a procedure for folding the airbag.

FIG. 5 is an exploded perspective view showing a locking relationship between an extension retainer and a switch plate. However, the airbag is omitted.

FIG. 6 is a partial cross-sectional view illustrating an operation of the airbag when inflated.

FIG. 7 is a view showing pads and the like for explaining a horn switch mechanism according to the second embodiment, and is a cross-sectional view taken along line LL of FIG. 3;

FIG. 8 is a sectional view taken along the line MM of FIG. 3;

FIG. 9 is an exploded perspective view showing a locking relationship between the extension retainer and the switch plate. However, the airbag is omitted.

FIG. 10 is a partial cross-sectional view illustrating an operation of the airbag when inflated.

[Explanation of symbols]

W: steering wheel, 1: pad, 2: airbag device, 3: bag holder, 4: inflator, 5: airbag, 6: ring retainer, 11: membrane switch, 13: switch plate, 21, 31: extension Extension retainer, 22 ... locking claw, 32, 33 ... through hole, 34, 35 ... locking projection.

Claims (5)

[Claims] A pad provided substantially at the center of a steering wheel; a bag-shaped airbag located below the pad; an inflator for generating gas when a predetermined acceleration is applied;
An airbag device having a bag holder for fixing the airbag and the inflator to a core metal of a steering wheel, and an airbag device having a ring retainer for fixing an opening edge portion of the airbag to the bag holder; A switch plate provided so as to cover the airbag device; and a membrane switch mounted and fixed on the switch plate at a predetermined distance from a lower surface of the pad, and for sounding a horn by pressing. A horn switch mechanism for a steering wheel with an airbag, comprising: an extension portion provided in at least one of the ring retainer, the inflator, and the bag holder, and at least one of the extension portion and the switch plate. The switch for the extension Horn switch mechanism of a steering wheel with an air bag, characterized in that the rate provided a locking mechanism for locking together with a part of the air bag. 2. The extension of the ring retainer, wherein:
The horn switch mechanism for a steering wheel with an airbag according to claim 1, wherein the horn switch mechanism is configured by connecting two end portions. 3. The steering according to claim 1, wherein the locking mechanism includes a locking claw provided on a lower surface of the switch plate and gripping the extension. Horn switch mechanism for wheels. 4. The locking mechanism includes a through hole formed in the extension portion, and a projection provided on a lower surface of the switch plate and engaged with the through hole. A horn switch mechanism for a steering wheel with an airbag according to any one of claims 1 to 3. 5. The device according to claim 1, wherein the switch plate is divided into a plurality of parts to ensure reliability when the airbag is inflated.
The horn switch mechanism for a steering wheel with an airbag according to any one of claims 1 to 4, further comprising a mechanism that is easily divided.