JPH10119789A - Steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make horn operability excellent in a steering wheel with a horn operated by push-down operation of a pad covering an air bag. SOLUTION: In a steering wheel W provided with an air bag device 14 and a horn switch mechanism 16, the air bag device 14 is formed as an assembly A including an inflator 32 and an air bag 34 and assembled to a wheel body 12, and the horn switch mechanism 16 includes a pad 48 and a plurality of self-reset type switch bodies 50, and is assembled to the wheel body 12. The pad 48 includes a top plate part 62 covering the upper part of the air bag 34, and a cylindrical part 64 surrounding the air bag 34. The cylindrical part 64 is reinforced by a reinforcing member provided with a fitting arm part 68 protruded outward from the periphery. The fitting arm part 68 is connected in a vertically movable state integrally with a movable side member 52 of the switch body 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel mounted on a vehicle, and more particularly, to a steering wheel provided with an airbag device and a horn switch mechanism which are assembled at a substantially central portion of a wheel body.

[0002]

2. Description of the Related Art A steering wheel of the type described above is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 2-143834.

[0003] The structure of the airbag device is such that the airbag device is folded and arranged, an inflator for supplying inflation gas to the airbag, a pad for covering the folded airbag, an airbag inflator. And a bag holder for holding the pad.

[0004] A horn switch mechanism has been arranged between the bag holder of the airbag device and the steering wheel body. The horn switch mechanism includes a pair of movable contact plates connected and fixed to the left and right sides of the bag holder, a fixed contact plate fixed to the steering wheel body below each movable contact plate, and a movable contact plate and a fixed contact plate. A coil spring as an urging means for urging the movable contact plate upward together with the airbag device, and separating the movable contact plate from the fixed contact plate by guiding the up and down movement of each movable contact plate And a guide member for regulating the distance.

The opposing movable contact plate and fixed contact plate constitute a switch body. Each movable contact plate is connected to the positive electrode side of a horn operating circuit, and each fixed contact plate is connected to a horn operating circuit. The core metal of the steering wheel body, which is conducted to the negative electrode side, comes into contact with the contact point, and the contact portion is arranged at a position corresponding to each movable contact plate and each fixed contact plate.

When the horn is operated, the pad is pushed, and each movable contact plate together with the airbag device is pushed down against the urging force of the coil spring, so that the contact portion of each movable contact plate becomes the contact portion of each fixed contact plate. The horn was activated by contact.

[0007]

However, in the conventional steering wheel, the entire airbag device is supported by a coil spring of a horn switch mechanism, and the weight of the airbag device itself is heavy. In order to prevent the sudden squeal, the horn stroke until the pad is depressed and the horn is activated is lengthened, and the horn operability is not good.

The present invention has been made to solve the above-mentioned problem, and provides a steering wheel in which a horn is operated by pushing down a horn pad that covers a folded airbag, thereby improving horn operability. The purpose is to:

[0009]

SUMMARY OF THE INVENTION A steering wheel according to the present invention is a steering wheel including an airbag device and a horn switch mechanism which are assembled at a substantially central portion of a wheel body. An airbag in a folded state and assembled to the wheel body, the horn switch mechanism is assembled to the wheel body including a pad and a plurality of spring self-returning switch bodies, and the pad comprises an airbag. A top plate portion that covers the upper part of the airbag, and a tubular portion that is smaller in diameter than the top plate portion and surrounds the periphery of the airbag, wherein the tubular portion is reinforced by a tubular portion reinforcing member, and the tubular portion reinforcing member is A plurality of mounting arms protruding outward from the outer periphery are provided corresponding to the number of switch bodies, and the mounting arms are integrally formed with the movable member of the switch body. Rotatably to be connected, pads, and the assembly of the airbag device, and is capable independent vertical movement, characterized in that.

Here, it is desirable that the outside of the cylindrical portion of the ceiling of the pad be reinforced by a ceiling reinforcing member connected to the cylindrical reinforcing member.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. Here, the four-spoke type will be described as an example, but the same applies to the two-spoke and three-spoke types.

(1) Steering wheel W of the embodiment
1 and 2 includes an airbag device 14 and a horn switch mechanism 16 which are assembled at a substantially central portion of the wheel main body 12 as shown in FIGS.

The wheel body 12 includes a wheel core 18.
However, except for the boss portion 20 and the spoke portion 22 from the center side, that is, the airbag device 14 and the horn switch mechanism 1
6 and a wheel covering portion 24 covered with plastic such as urethane resin. In the illustrated example, the boss 20
Is a split cylindrical shape to which the steering shaft 26 can be fastened by the screw means 28. In addition, 30 is a lower cover.

The airbag device 14 includes an inflator 32
And an airbag 34 in a folded state, and is assembled to the wheel body 12 as an assembly body A. Specifically, the airbag 34 is fastened to the flange portion 34 of the inflator 32 by a bag holder (base plate) 38 and screw means (bolts 40, nuts 41) to form an assembly A of the airbag device 14. I have. The assembly A is fixed to the spoke portion 22 of the wheel body 12 by screw means (bolts 42, nuts 43). In the above description, the spokes may be widened or the flange of the inflator may be long, so that the assembly composed of the airbag and the inflator may be directly attached to the wheel body without using the bag holder. In the illustrated example, reference numeral 44 denotes a retainer, and reference numeral 46 denotes a protection film for maintaining and protecting the folded airbag 34 until the airbag device is activated.

The horn switch mechanism 16 includes a pad 48 and a plurality of (three in the illustrated example) switch bodies 5 of a spring self-return type.
0 and is assembled to the wheel body 12.

Here, the switch body 50 includes a movable member 52 and a fixed member 54 each having a contact on the opposite surface.
Are configured to be capable of contacting and separating via a coil spring 56, and include screw means (a stepped bolt 58, a nut 5
9) is attached to the bag holder 38.
Although not shown, the contact of the movable side member 52 is connected to a lead wire connected to the positive side of the battery.
The contact point of the fixed member 54 is grounded to the vehicle body via the base plate 38, the wheel core 18 and the steering shaft 26. The configuration of the switch body 50 is not limited to the illustrated example, and may be a built-in type such as a leaf spring body.

The pad 48 has a top plate 62 that covers the upper part of the airbag 34, and a smaller diameter airbag 3 than the top plate 62.
4 and a cylindrical portion 64 surrounding the periphery of the second member 4. The tubular portion 64 is reinforced by a tubular portion reinforcing member 66a. The tubular portion reinforcing member 66a is provided with a plurality of mounting arms 68 projecting outward from the outer periphery corresponding to the number of switch bodies 60 (three in the illustrated example). As in the conventional case, when the airbag is inflated, an H-shaped breakable portion 49 is formed which breaks to form an airbag pop-out opening.

In the illustrated example, the pad 48 is separated from the wheel covering portion 24. However, the pad 48 may be integrally formed with the wheel covering portion 24 connected by an integral hinge portion.

The mounting arm 68 is connected to the movable member 52 of the switch body 50 so as to be able to move up and down integrally. As a result, the pad 48 is connected to the airbag device 14.
And the assembly A can be independently moved up and down.

Although not inevitable, from the viewpoint of improving the horn operability, the ceiling portion 62 of the pad 48 is provided with a ceiling reinforcement in which the outer and inner portions of the cylindrical portion 64 are connected to the cylindrical reinforcing member 66a. It is reinforced by the member 66b. In this case, the horn operability can be improved only by the outer portion. The reinforcing member 66 is usually integrated by insert molding when the horn pad 48 is formed, but a separate molded body may be attached later. The material of the reinforcing member 66 is usually
It is made of metal, but may be made of rigid plastic.

(2) Next, an assembling mode of the above embodiment will be described.

First, the assembly A of the airbag device 34 (comprised of the airbag 34, the inflator 32, and the bag holder 38) is screwed and fixed to a substantially central portion of the wheel core 18 from below. At this time, the nut 43 is welded to the upper surface side of the bag holder 38 so that the bolt 42 can be screwed in from below.

Next, the pad 48 is supported by the switch body 50 and screwed. That is, the switch body 50 is mounted on the upper surface side of the bag holder 38 by a clip or the like (not shown), and then is mounted on the movable member 54 of the switch body 50 so as to protrude toward the outer peripheral side of the pad 48. 68, and fix it with screws from below. At this time, the nut 59 is welded to the upper surface side of the mounting arm portion 68, and the stepped bolt 58 is screwed from below, so that the mounting arm portion 68 can be fixed without play.

Subsequently, the lower cover 30 is fixed by screwing, clipping, or the like, and the assembly of the steering wheel W of this embodiment is completed.

(3) The steering wheel is mounted on an actual vehicle and used in the same manner as in the prior art.

When the horn is blown, the horn pad 48 is pressed, and the movable side member 52 of the switch body 50 is
The pressing force is transmitted via the cylindrical reinforcing member 66a and the mounting arm portion 68, and the movable member 52 is lowered against the spring force, the switch body 50 becomes conductive, and the horn blows.

The coil spring 56 of each switch body 50 does not support the entire airbag device but supports only the lightweight pad 48. Therefore, a coil spring having a small spring force can be used, and the horn operation load is reduced. As the size decreases, the horn stroke for preventing unexpected noise can also be set to a small value.

If the gap α between the airbag 34 and the pad 48 is made larger than the horn stroke as shown in the figure, when the pad 48 is pressed, the back surface of the pad 48 comes into contact with the airbag 34. Therefore, it is possible to prevent an increase in the pressing force at the time of operating the horn.

When the airbag device is operated, the pad 4
8 receives an upward force, but the mounting arm 68 of the reinforcing member 66 is screwed down with a stepped bolt 58 that engages with the airbag holder 38 on the lower surface without looseness, and the pad is substantially fixed. It is not different from the case. For this reason,
As in the conventional case, the airbag 34 protrudes from the opening formed by breaking the rupture expected portion 49 of the pad 48.

[0030]

In the steering wheel according to the present invention, the pad includes a top plate that covers the upper portion of the airbag, and a tubular portion that is smaller in diameter than the top plate and surrounds the periphery of the airbag. The portion is reinforced by a tubular portion reinforcing member, and the tubular portion reinforcing member includes a plurality of mounting arms protruding outward and corresponding to the number of switch bodies, and the mounting arm section is movable with the switch body. The following operations and effects are achieved by a configuration in which the pad is connected to the contact so as to be vertically movable and the pad can be vertically moved independently of the assembly body of the airbag device.

When the pad is pressed, the pad is lowered against the spring force, and the contact portion on the pad side is brought into contact with the contact portion on the bag holder side, so that the horn can be operated.

At this time, since the spring body of the switch body supports only a lightweight (horn pad), a spring body of a self-returning type switch body having a small spring force can be used. The horn stroke for preventing unexpected noise can be reduced.

Therefore, in the steering wheel of the present invention, horn operability can be improved in the steering wheel in which the horn is operated by pressing down the pad covering the folded airbag.

When the outer portion of the cylindrical portion in the ceiling portion of the pad is reinforced by the ceiling reinforcing member connected to the cylindrical reinforcing member, the escape when the horn is operated, that is, when the pad is pressed, is prevented. It can be prevented reliably, and the horn operability is further improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a steering wheel according to an embodiment of the present invention (a section taken along line 1-1 in FIG. 2).

FIG. 2 is a schematic plan cross-sectional view of a half cutaway in which an airbag is omitted.

[Explanation of symbols]

 12: Wheel body, 14: Airbag device, 16: Horn switch mechanism, 18: Wheel core 32: Inflator, 38: Bag holder (base plate), 48: Pad, 50: Switch body, 52: Fixed side of switch body 56, a coil spring (spring body), 58, a movable side member of a switch body, 62, a top plate portion of a pad, 64, a tubular portion of a pad, 66, a reinforcing member of a tubular portion, 68, a mounting arm portion,

Claims (2)

[Claims] 1. A steering wheel provided with an airbag device and a horn switch mechanism that is assembled at a substantially central portion of a wheel body, wherein the airbag device includes an assembly including an inflator and a folded airbag. The horn switch mechanism is assembled to the wheel body including a pad and a plurality of spring self-returning switch body, the pad is a top plate portion that covers the upper part of the airbag, A cylindrical portion that is smaller in diameter than the top plate portion and surrounds the periphery of the airbag, the cylindrical portion is reinforced by a cylindrical portion reinforcing member, and the cylindrical portion reinforcing member protrudes outward from the outer periphery. A mounting arm portion is provided corresponding to the number of the switch bodies, and the mounting arm portion is connected to a movable side member of the switch body so as to be integrally movable up and down. Steering wheel head is said The assembly of the airbag device, and is capable independent vertical movement, characterized in that. 2. The steering wheel according to claim 1, wherein an outer portion of the cylindrical portion in a ceiling portion of the pad is reinforced by a ceiling reinforcing member connected to the cylindrical reinforcing member.