JPH05170107A - Steering wheel mechanism - Google Patents

Abstract

PURPOSE:To expand and protrude an air bag toward a driver regardless of the rotational position of a steering wheel and surely protect the driver by invariably directing the air bag in one and same direction without rotating it when the steering wheel is operated and rotated. CONSTITUTION:Multiple planetary gears 12 are rotatably fitted to a steering wheel 15, one end side 12a of the planetary gears 12 is engaged with the internal gear 11b of a fixed lower ring gear 11, the other end side 12b is engaged with the internal gear of an upper ring gear 13, thus the upper ring gear 13 is made stationary and invariably directed in the fixed direction when the steering wheel 15 is rotated, and an air bag 14 is fitted to the portion integral with the upper ring gear 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel mechanism for a vehicle, and particularly when the steering wheel is operated and rotated, the airbag does not rotate but always faces in the same direction. At the time of operation, regardless of the rotational position of the steering wheel, the airbag is inflated and projected toward the driver, that is, it is deployed so that the driver can be reliably protected. The present invention relates to a steering wheel mechanism suitable for a cab-over type vehicle such as a truck or a bus that is mounted in a substantially horizontal state.

[0002]

2. Description of the Related Art As a conventional air bag, as shown in FIG. 5, the air bag 3 is mounted on the spokes 1a of a steering wheel 1 so that when a vehicle 2 collides, the air bag 3 extends in the axial direction of the steering shaft 4 (direction of arrow A). In the conventional airbag, particularly in the airbag 3 on the driver's seat side such as a truck or a bus, the tilt angle of the steering shaft 4 is large and the steering wheel 1 is almost horizontal. Since the airbag 3 is mounted, the airbag 3 expands upward, and depending on the driving posture of the driver 5, the driver cannot be effectively protected, and the chest 5a and the abdomen 5b of the driver 5 are attached to the steering wheel 1. Could collide. Therefore, there is a drawback that the airbag 3 must be made large in order to eliminate such a drawback.

As another method for eliminating the above drawbacks,
Like deploying the airbag toward the driver,
It is also proposed to attach an airbag to a steering wheel toward a driver. However, according to this device, when the steering wheel is operated and rotated, the airbag rotates with the steering wheel and the deployment direction also rotates. However, there is a drawback in that the airbag cannot be deployed in a desired direction and the driver 5 cannot be effectively protected.

In order to eliminate this drawback, the actual Kaihei 1-141351 is provided with a plurality of straps inside the airbag, and only the predetermined straps are effectively operated in accordance with the operation of the steering wheel so that the shape of the airbag when inflated. Although what deforms into a desired shape is disclosed,
The airbag device has a drawback that the structure is complicated and that only a predetermined strap needs to be engaged with the stopper, so that the operation is somewhat uncertain.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to mount a plurality of planetary gears on a steering wheel in a freely rotatable manner. , By engaging one end side of the planetary gear with the fixed lower ring gear and further engaging the other end side with the upper ring gear so that the upper ring gear does not rotate even when the steering wheel is rotated so that it is stationary. That is.

Another object of the present invention is to fix and mount an airbag on a portion integrated with the upper ring gear so that the airbag is always deployed in a predetermined direction regardless of the rotational position of the steering wheel, that is, the steering angle. In order to allow it to be deployed to the driver, even when the steering wheel is installed in a state that is almost horizontal, such as in a cab-over truck or bus, this will The bag is surely inflated and projected toward the driver so that the driver can be protected surely.

[0007]

SUMMARY OF THE INVENTION In short, the present invention is directed to a lower ring gear fixed to a base for rotatably supporting a steering shaft via a bearing member and having an internal gear formed on an inner peripheral surface thereof, and a steering wheel. A plurality of planetary gears that penetrate through holes formed in the spokes of the wheel and are rotatably attached to the spokes and that mesh with the lower ring gear at one end side, and mesh with the other end side of the planetary gear at the inner peripheral surface. And an upper ring gear that is formed to have an internal gear and that is stationary even when the steering wheel is rotated, and an airbag is mounted on a portion integrated with the upper ring gear. Is to

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. 1 to 3, a steering wheel mechanism 10 according to the present invention includes a lower ring gear 11, a planetary gear 12, and an upper ring gear 13.

The lower ring gear 11 is the planetary gear 1.
A base 2 for rotatably driving the steering wheel 2, which rotatably supports a steering shaft 18 fixed to a spoke 15a of a steering wheel 15 by a nut 16 via a ball bearing 19 which is an example of a bearing member.
0 is integrally formed at the upper end of 0 and has a cup shape with an open upper side, and an internal gear 11b is formed over the entire circumference on its inner peripheral surface 11a having the same axis as the steering shaft 18, The planetary gear 12 is attached to the internal gear 11b.
Are configured to revolve while meshing and rolling.

The planetary gear 12 is the upper ring gear 1.
When 3 is viewed from the planetary gear, it is rotationally driven relatively, and as a result, fixed coordinates, that is, stationary with respect to the vehicle body of the vehicle 28, despite the rotational movement of the steering wheel 15, To keep the upper ring gear 13 stationary with respect to the vehicle body,
The two sets of gears, which are formed as gears having the same number of teeth that are long in the axial direction and are rotatably supported by the shaft 19, are spokes 15.
The steering shaft 18 passes through the hole 15b formed in a.
Are arranged on the same circumference of the axis.

The shaft 19 is fixed to a substantially U-shaped support plate 22 made of a metal plate fixed to the spokes 15a with screws 20. One end side 12a of the planetary gear 12 that protrudes below the spoke 15a meshes with the internal gear 11b formed on the lower ring gear 11.
When the steering wheel 15 is rotated, the internal gear 1
It is driven by 1b to rotate about a shaft 19 and revolve around the axis of the steering shaft 18 together with the spoke 15a.

Like the planetary gear 12, it is rotatably mounted around a shaft 24 supported by a support plate 23 fixed to the spokes 15a, and is provided so as to penetrate through holes 15b formed in the spokes 15a. One end 25a of the rubber roller 25 is in contact with the inner peripheral surface 11a of the lower ring gear 11, and when the steering wheel 15 is rotated,
Steering shaft 1 while rotating around shaft 24
It revolves around the axis of 8.

The upper ring gear 13 is for supporting the airbag 14 so as not to change the deployment direction thereof, and is the ring-shaped bearing portion 1 fixed to the spokes 15a.
5c is rotatably fitted, and the E-ring 26 prevents the ring-shaped bearing portion 15c from coming off. Also, the upper ring gear 13 having the same axis as the steering shaft 18
An internal gear 13b is formed over the entire circumference on the inner peripheral surface 13a of the planetary gear 1b.
The planetary gear 12 meshes with the other end side 12b of the second spoke 15a protruding upward, and is relatively driven to rotate by the planetary gear 12 when viewed from the planetary gear.

Further, the other end 25b of the rubber roller 25 is in contact with the inner peripheral surface 13a of the upper ring gear 13, and when the steering wheel 15 is rotated, the planetary gear 1
While absorbing the backlash between 2 and the internal gear 13b by the elastic force of rubber, it revolves around the axis of the steering shaft 18 while rotating around the shaft 24.

The airbag 14 generates gas from the inflator 26 at the time of collision of the vehicle 28, expands and deploys gas by the gas, restrains the driver 29, absorbs the shock, and damages the body of the driver 29. The upper ring gear 13 is mounted on the upper end of the upper ring gear 13 while being inclined from the axis of the steering shaft 18 toward the driver 29. When the vehicle 28 collides, the airbag 14
Is inflated and projected toward the driver 29 to prevent the driver 29 from colliding with the steering wheel 15 and being damaged.

The present invention is configured as described above,
The operation will be described below. 1 to 4, when the steering wheel 15 is rotated clockwise, for example, it is rotatably supported by the spokes 15a.
The planetary gear 12 and the rubber roller 25 of the set make an orbital motion around the axis of the steering shaft 18 in the clockwise direction together with the spoke 15a.

At this time, the planetary gear 12 meshes with the internal gear 11b of the fixed ring gear 11, and the rubber roller 25 is in contact with the inner peripheral surface 11a.
Rotate counterclockwise around 9 and 24.
That is, the planetary gear 12 and the rubber roller 25 perform the revolution movement in the clockwise direction while performing the rotation movement in the counterclockwise direction.

At this time, the ring gear 13 is supposed to rotate clockwise due to the clockwise revolution movement of the planetary gear 12, but is actually stationary. This is because the planetary gear 12 is simultaneously returned in the counterclockwise direction by the counterclockwise rotation of the planetary gear 12 at the same peripheral speed as the clockwise peripheral speed of the revolution movement.

This will be described in more detail. With regard to the planetary gear 12, the peripheral speed due to the clockwise revolution movement and the peripheral speed due to the counterclockwise rotation movement are offset, and the internal gear of the ring gear 13 of the planetary gear 12 is cancelled. 1
The peripheral velocity at the meshing point on the pitch circle with 3b is fixed coordinate, that is, 0 with respect to the vehicle body.

As a result, the upper ring gear 13 does not rotate even if the steering wheel 15 is operated and rotated,
It is completely stationary and retains its initial position. This action is the same regardless of the steering angle of the steering wheel 15, the upper ring gear 13 does not rotate, and even in the cab-over type vehicle in which the steering wheel 15 is mounted in a nearly horizontal state, a predetermined level is always maintained. Since the air bag 14 is directed to the direction, the airbag 14 attached to the portion integrated with the upper ring gear 13 can always inflate and project toward the driver 29 in the arrow B direction when the airbag 14 is deployed.

And in the unlikely event that the vehicle 28 collides,
Gas is generated from the inflator 26 to cause the airbag 14
Can be inflated and expanded toward the driver 29 in the direction of arrow B to absorb the shock and protect the driver 29.

In the above embodiment, the vehicle 28
Has been described as a cab-over type vehicle in which the steering wheel 15 is mounted almost horizontally, but the vehicle 28 is not limited to the cab-over type vehicle.
Obviously, it can be applied to passenger cars and the like.

[0023]

As described above, according to the present invention, a plurality of planetary gears are rotatably mounted on the steering wheel as described above, one end side of the planetary gears is meshed with the fixed lower ring gear, and the other end side is the upper ring gear. Since there is meshing with the above, there is an effect that the upper ring gear does not rotate even when the steering wheel is rotated, so that the upper ring gear remains stationary.

Further, since the air bag is fixedly attached to the portion integral with the upper ring gear, the driver always regulates the air bag deployment direction to a predetermined direction regardless of the rotational position of the steering wheel, that is, the steering angle. As a result, even if the steering wheel is installed in a state where the steering wheel is close to horizontal as in a cab-over type truck or bus, the airbag should be directed toward the driver. The excellent effect that the driver can be surely protected by inflating and protruding is obtained.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention, and FIG. 1 is a vertical cross-sectional side view of a steering wheel mechanism.

FIG. 2 is a front view of a steering wheel mechanism.

FIG. 3 is an exploded perspective view of a main part of a steering wheel mechanism.

FIG. 4 is a side view showing a state in which the airbag inflates and projects toward the driver to protect the driver.

FIG. 5 is a side view showing a state in which the airbag is inflated and projected upward and cannot sufficiently protect the driver according to the conventional example.

[Explanation of symbols]

 10 Steering Wheel Mechanism 11 Lower Ring Gear 11a Inner Surface 11b Internal Gear 12 Planetary Gear 12a One End Side 12b Other End 13 Upper Ring Gear 13a Inner Surface 13b Internal Gear 14 Airbag 15 Steering Wheel 15a Spoke 15b Hole 18 Steering Shaft 19 Ball bearing 20 base which is an example of bearing member

Claims (1)

[Claims] A lower ring gear fixed to a base rotatably supporting a steering shaft via a bearing member and having an internal gear formed on an inner peripheral surface thereof, and a hole formed in a spoke of a steering wheel. A plurality of planetary gears that are rotatably attached to the spokes and that mesh with the lower ring gear at one end side; and an internal gear that meshes with the other end side of the planetary gears on the inner peripheral surface of the steering wheel. A steering wheel mechanism, comprising: an upper ring gear configured to be stationary even when rotated, and an airbag being mounted on a portion integrated with the upper ring gear.