JPH0741639Y2 - Steering wheel with airbag device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a steering wheel of an automobile to which an airbag device is attached, and in particular, the horn can be operated by pressing the airbag device. It relates to the steering wheel.

(Prior Art) An airbag device has come to be used as one of occupant protection devices for restraining an occupant at a sitting position when a vehicle crashes. This airbag device introduces high-pressure gas generated from an inflator into the airbag at the time of a collision of the vehicle, so that the airbag is rapidly inflated and deployed toward the occupant to regulate forward movement of the occupant. Normally, the airbag is folded and stored in an airbag storage body together with an inflator, and is a unit covered with an airbag cover. In the case of an airbag device for the driver's seat, such a unit is generally mounted in the central part of the steering wheel.

By the way, it is necessary to provide a horn switch for operating a horn on a steering wheel of an automobile. An ordinary horn switch is composed of a movable contact and a fixed contact, and the movable contact is brought into pressure contact with the fixed contact by pressing a horn pad. In the case of a normal steering wheel, its horn pad is provided at the center of the steering wheel. Therefore, the horn pad can have a large area.

However, in the case of a steering wheel provided with an airbag device, since the airbag device is installed in the central portion of the steering wheel as described above, the horn pad must be provided in the spoke portion or the like in the peripheral portion. Absent. Therefore, the horn pad cannot be made large, which is disadvantageous in terms of design.

For this reason, in the steering wheel to which the airbag device is attached, it is considered to movably support the airbag device with respect to the steering wheel so that the entire airbag device has a function as a horn pad. Has been. In that case, as the horn switch, one having mechanical contacts similar to the conventional one was used.

(Problems to be solved by the invention) By the way, in the case of a horn switch composed of mechanical contacts, it is necessary to ensure that the movable contact is normally held away from the fixed contact. Moreover, the contacts must be in contact with each other and the horn must be actuated by only lightly pressing the horn pad. Therefore, it is necessary to movably support the horn pad with a soft coil spring and increase the moving stroke of the movable contact.

However, when the airbag device is used as a horn pad, since the airbag device has a weight of about 2 kg, it is difficult to support it with such a soft coil spring. However, it is necessary to add a special support mechanism, which is expensive. In addition, the airbag device vibrates greatly due to the vibration of the steering system and the like, so that the durability of the airbag device also decreases.

Further, since the airbag device has a considerable thickness, in order to move the airbag device with a large stroke, it is necessary to largely project it from the surface of the steering wheel. Therefore, the appearance is impaired.

The present invention has been made in view of such a problem, and an object thereof is to enable actuation of a horn without significantly moving the airbag device.

(Means for Solving the Problem) In order to achieve this object, according to the present invention, a pressure-sensitive horn switch is provided at a portion that is pinched between an airbag device and a steering wheel when the airbag device is pressed. In addition, the airbag device and the steering wheel are connected to each other via a rubber-like elastic member that is deformed by a size corresponding to the operation stroke of the horn switch. The horn switch is
It is composed of a pair of flexible electrode plates and a pressure conductive rubber disposed between the electrode plates, and both surfaces thereof are brought into contact with the airbag device and the steering wheel, respectively. Pressurized conductive rubber normally exhibits insulating properties and becomes conductive when pressed.

(Operation) With this configuration, when the airbag device is pressed, the horn switch is pinched between the airbag device and the steering wheel, and the pressure conductive rubber of the horn switch is mediated by the electrode plate. It is pressurized from both sides. Therefore, conduction is established between the pair of electrode plates, and the horn operates. When the pressing force on the airbag device is removed, the pressure conductive rubber becomes insulative and the gap between the electrode plates is cut off, and the operation of the horn is stopped.

In such a steering wheel, the airbag device may be movably supported by a stroke that can transmit a pressing force to the horn switch. Therefore, it is not necessary to use a complicated support mechanism that allows a large movement stroke.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a steering wheel according to the present invention, FIG. 1 is a front view thereof, and FIG. 2 is an enlarged sectional view of an essential part. Further, FIG. 3 is an illustration of a horn switch attached to the steering wheel.

As is apparent from FIG. 1, the steering wheel 1 is provided with an airbag device 2 at the center thereof. As shown in FIG. 2, the airbag device 2 includes an airbag 3 and an inflator 4.
The airbag 3 is stored in an airbag storage body 5 together with the inflator 4 in a tightly folded state.
The surface of the storage body 5 facing the driver's seat is covered with an airbag cover 6 that is easily broken when the airbag 3 is inflated and deployed. The airbag cover 6 is made of a hard resin, and the peripheral portion of the airbag cover 6 is fixed to the flange 5a around the storage body 5. Thus, the airbag device 2 is a unit independent of the steering wheel 1.

The airbag housing 5 is made of a steel plate, and a bracket 7 that is inclined outward is welded to the back surface thereof. On the other hand, on the steering wheel 1 side, the bracket 7
A mounting plate 8 that is in sliding contact with is fixed. The bracket 7 and the mounting plate 8 are surrounded by a rubber grommet 9
Are connected to each other by bolts 10 mounted with.

In this way, the airbag device 2 is supported by the steering wheel 1 via the rubber grommet 9 which is an elastic member, and can move with a small stroke with respect to the steering wheel 1.

At the center of the steering wheel 1, there is formed a supporting surface 1a which faces the flange 5a of the airbag housing 5 at a small interval when the airbag device 2 is thus mounted. Then, a strip-shaped horn switch 11 is provided between the flange 5a and the support surface 1a such that both surfaces thereof contact the flange 5a and the support surface 1a, respectively. As shown in FIG. 3, this horn switch 11 has a strip-shaped pressure conductive rubber 13 sandwiched between a pair of electrode plates 12, 12, and the outer periphery of the horn switch 11 is made of silicon rubber or the like, which is flame-retardant and highly elastic. It is covered with an insulating material 14 having. The electrode plate 12 is formed by flat knitting a large number of ultrafine copper wires, and has flexibility. The pressure conductive rubber 13 is made of silicon rubber mixed with metal fine particles and normally has an insulating property, but becomes conductive when pressed. Such a strip-shaped switch 11 is commercially available as a "cord switch". The electrode plates 12 and 12 are connected to a horn circuit including a power supply 15 and a horn 16.

In the steering wheel 1 thus configured, when the driver presses the airbag cover 6, the pressing force is transmitted to the rubber grommet 9 via the airbag housing 5 and the bracket 7, and the rubber grommet 9 is deformed. As a result, the entire airbag device 2 slightly advances with respect to the steering wheel 1. As a result, the horn switch 11 is pinched between the flange 5a of the airbag container 5 and the support surface 1a of the steering wheel 1. Then, the clamping force is transmitted to the pressurizing conductive rubber 13 via the elastic coating insulating material 14 and the flexible electrode plates 12, 12, and the conductive rubber 13 is pressed from both sides. Therefore, the pressure conductive rubber 13 becomes conductive, the electrode plates 12 and 12 are electrically connected, and the horn 16 operates.

When the pressing force on the airbag device 2 is removed, the elasticity of the rubber grommet 9 and the covering insulating material 14 of the horn switch 11 restores the airbag device 2 to its original state, and the pressure applied to the pressure conductive rubber 13 is removed. . Therefore, the conductive rubber 13 becomes insulating, the electrode plates 12 and 12 are cut off from each other, and the operation of the horn 16 is stopped.

In this way, the steering wheel 1 using the airbag device 2 as a horn pad can be obtained.

The horn switch 11 using such a pressure conductive rubber 13 as a switch element operates with an extremely small stroke of 1 mm or less. Therefore, the airbag device 2 may be movably supported by a simple elastic member such as the rubber grommet 9. As a result, the airbag device 2 can be easily attached to the steering wheel 1 and maintenance can be facilitated. Further, since the vibration of the airbag device 2 can be suppressed to be small, durability and reliability are increased.

Further, such a belt-shaped horn switch 11 operates even if only a part thereof is pressurized. Therefore, the airbag device 2 may tilt when the airbag cover 6 is pressed. That is, the horn 16 operates even if any part of the airbag cover 6 is pressed, and the operability becomes extremely good.

Further, such a horn switch 11 can be made as thin as several mm. Therefore, even if such a horn switch 11 is provided between the airbag device 2 and the steering wheel 1, the airbag device 2 does not significantly project. Moreover, since the movement stroke of the airbag device 2 may be extremely small as described above, the clearance between the airbag device 2 and the steering wheel 1 for allowing the movement can be reduced. Further, it is not necessary to provide a small horn pad on the spoke portion or the like of the steering wheel 1. As a result, the degree of freedom in designing the steering wheel 1 is increased, and the appearance can be improved.

When the airbag device 2 is operated, high-pressure gas is ejected from the inflator 4, and the airbag 3 is inflated and deployed to contact the driver. At that time, the reaction force acts on the airbag storage body 5. However, the reaction force is supported not only on the connecting portion between the bracket 7 and the mounting plate 8 but also on the support surface 1a of the steering wheel 1 through the horn switch 11 from the flange 5a of the housing body 5. Therefore,
It is possible to obtain sufficient reliability.

Furthermore, the operating pressure of such a horn switch 11 can be arbitrarily adjusted by appropriately setting the elasticity and the like of the covering insulating material 14. Therefore, the horn 16 does not operate due to normal vibration or the like, and when the airbag device 2 is pressed, the horn 16 can be operated with a relatively small pressing force.

In the above embodiment, the belt-shaped horn switch 11 is provided between the flange 5a of the airbag housing 5 and the support surface 1a of the steering wheel 1. However, the switch 11 is provided on the back surface of the inflator 4. Any portion such as a portion between the mounting plate 8 of the steering wheel 1 and the member on the side of the steering wheel 1 when the airbag device 2 is pressed can be arbitrarily provided. it can. In that case, the horn switch
The 11 can also have a planar shape or the like instead of the strip shape.

Further, the rubber-like elastic member that connects the airbag device 2 to the steering wheel 1 is not limited to the rubber grommet 9 as in the above embodiment, but a support base-shaped rubber block or the like may be used.

Further, although the airbag cover 6 is made of a hard resin in the above-mentioned embodiment, the present invention can be applied to the case where the airbag cover 2 has flexibility. That is, since the airbag 3 is tightly housed on the back side of the airbag cover 6, even if the airbag cover 6 has flexibility, the pressing force applied to the cover 6 will not affect the airbag. It is transmitted to the airbag storage body 5 through the inflator 3 and the inflator 4. Therefore,
The horn switch 11 can be clamped between the airbag device 2 and the steering wheel 1.

(Effect of the Invention) As is apparent from the above description, according to the present invention, since the airbag device is used as the horn pad, the horn pad is provided in the central portion of the steering wheel and has a large area. It becomes possible.
Therefore, the operability is improved, the degree of freedom in designing the steering wheel is increased, and the appearance can be improved.

Further, since the pressure sensitive horn switch using the pressure conductive rubber is provided between the airbag device and the steering wheel, the horn can be operated without moving the airbag device largely. It will be possible.
Therefore, the airbag device only needs to be connected to the steering wheel via a relatively hard rubber-like elastic member that can be deformed by a size corresponding to the operation stroke of the horn switch, and the airbag device can be mounted. It becomes easy and the durability and reliability can be improved. Moreover, it is possible to eliminate an extra clearance between the airbag device and the steering wheel. Further, since the movement stroke of the airbag device is suppressed to be small, the entire steering wheel including the airbag device can be compactly assembled, so that the degree of freedom in design can be further increased.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of a steering wheel equipped with an airbag device according to the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is an enlarged sectional view of FIG. 3, and FIG. 3 is an explanatory diagram of a horn switch attached to the steering wheel. 1 …… Steering wheel 2 …… Airbag device 9 …… Rubber grommet (elastic member) 11 …… Horn switch, 12 …… Electrode plate 13 …… Pressurized conductive rubber, 16 …… Horn

Claims (1)

[Scope of utility model registration request] 1. A steering wheel in which an airbag device is installed in a central portion; A pair of flexible members are provided at a portion between the airbag device and the steering wheel when the airbag device is pressed. Sex electrode plate and arranged between the electrode plates,
Normally, the electrode plates are held in an insulated state, but a horn switch made of a pressure conductive rubber that conducts between the electrode plates when pressure is applied, and both sides of the horn switch are respectively attached to the airbag device and the steering wheel. The airbag device is provided so as to be in contact with the steering wheel, and the airbag device is connected to the steering wheel via a rubber-like elastic member that is deformed by a size corresponding to an operation stroke of the horn switch. A steering wheel equipped with an airbag device.