JPH092312A - Steering angle ratio variable device - Google Patents

Abstract

PURPOSE: To provide a simply constructed steering angle ratio variable device. CONSTITUTION: A steering main shaft 16 is coaxially connected to the first rotary member 22 of an Oldham's coupling 28. The second rotary member 24 is rotatably supported in a movable housing 32 which can be shifted in the direction crossing the shaft center of the second rotary member 24 at right angles. The third rotary member 26 of the Oldham's coupling 28 is rotatably and slidably inserted into a groove 50 of a projected part 48 formed on a steering rod 20 crossing the steering main shaft 16. When the amount of eccentricity H between the shaft center of the first rotary member 22 and the shaft center of the third rotary member 26 is changed, the amount of deflection of the third rotary member 26 at the time when a steering wheel is swung, is changed, and thus the stroke of the steering rod 20 engaged with the third rotary member 26 is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering angle ratio variable steering system capable of changing a ratio between an operation angle of a steering wheel and a turning angle of a steering wheel.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a steering angle ratio variable steering device for a vehicle, which is used in a vehicle such as an automobile and can change a ratio between a steering operation angle and a steering wheel turning angle according to various conditions such as a vehicle speed. Japanese Patent Laid-Open No. 6-22
The variable steering angle ratio steering device for a vehicle shown in Japanese Patent No. 7423 can be raised.

As shown in FIG. 4, an input shaft 100 of this variable steering ratio steering device for a vehicle is connected to a steering wheel (not shown), and an output shaft 102 is a pinion (not shown) of a rack and pinion mechanism. Are linked to. Output shaft 1
An eccentric intermediate shaft 104 is provided at the shaft end of 02, and the intermediate shaft 104 is integrally formed with the input shaft 100 via the slider 106.
10 is slidably engaged. The output shaft 102 is rotatably supported by a support member 112 that is moved in a direction orthogonal to the axis of the input shaft 100. By changing the amount of movement of the support member 112, the steering angle ratio can be changed. There is.

[0004]

However, in this vehicle steering angle ratio varying device, since the input shaft 100 and the output shaft 102 are eccentric, when actually applied to a vehicle, the steering wheel and the rack and A crankshaft, an Oldham coupling, and the like that absorb eccentricity are required separately from the pinion mechanism, which increases the size of the device and complicates the configuration.

In view of the above facts, an object of the present invention is to provide a variable steering angle ratio steering device for a vehicle, which has a simple structure and does not need to use a separate component such as a joint even when applied to a vehicle. .

[0006]

A variable steering angle ratio steering apparatus for a vehicle according to the present invention comprises a first rotating member, a second rotating member, and
An Oldham coupling having a third rotating member provided between the first rotating member and the second rotating member, and a steering operation connected to any one of the first rotating member and the second rotating member. Is connected to the other of the first rotating member and the second rotating member, and the eccentric amount between the first rotating member and the second rotating member is variable. And an eccentric means for engaging the third rotating member to take out a predetermined tangential movement of the third rotating member and transmit the tangential movement to an output shaft connected to a steering wheel of a vehicle. And engaging means.

[0007]

The variable steering angle ratio steering apparatus of the present invention uses, for example, the first rotary member connected to the rotary shaft and the third rotary member connected to the output shaft via the engaging means.

When the rotating shaft is rotated by the steering operation, the first rotating member, the second rotating member and the third rotating member are rotated.

When the center of rotation of the first rotary member and the center of rotation of the second rotary member are eccentric by the eccentric means and the first rotary member is rotated by a predetermined angle, the third rotary member swings.
The tangential movement of the swinging third rotating member is taken out by the engaging means and is transmitted to the output shaft, so that the steered wheels of the vehicle turn.

When the eccentric means changes the amount of eccentricity between the rotation center of the first rotary member and the rotation center of the second rotary member, the third rotation when the first rotary member is rotated. It is possible to change the amount of whirling of the member, thereby changing the amount of movement of the output shaft, that is, to change the steering angle ratio (ratio between the steering operation angle and the steering wheel turning angle).

For example, the center of rotation of the first rotating member and the second
When the amount of eccentricity with the rotation center of the rotating member of the
The whirling amount of the third rotating member when rotating the rotating member is increased, and the output shaft can be largely moved even if the angle change of the rotating shaft is small. That is, the direction of the steered wheels can be largely changed with a few steering operations.

On the other hand, if the amount of eccentricity between the rotation center of the first rotating member and the rotation center of the second rotating member is reduced, the whirling amount of the third rotating member when the first rotating member is rotated. Can be reduced, and the amount of movement of the output shaft with respect to changes in the angle of the rotating shaft can be suppressed. That is, it is possible to suppress the change in the direction of the steered wheels due to the steering operation to be small.

As described above, in the vehicle steering angle ratio variable steering apparatus of the present invention, the whirling caused by changing the eccentric amount of the Oldham coupling is utilized, and the whirling is converted into the movement of the output shaft in the axial direction. By doing so, steering can be performed. Therefore, it is not necessary to use a separate component such as a joint, and the structure is simple. Further, since the steering angle ratio is only changed, the neutral point of the steering wheel does not change.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the vehicle steering angle ratio variable steering system 10 includes a steering housing 12.
A steering main shaft 16 as a rotating shaft connected to a steering wheel 14 of the vehicle is rotatably supported in the steering housing 12 via a ball bearing 18.

Further, the steering housing 12 includes
The steering rod 20 is slidably supported in the direction of the arrow D in the direction of the axis of the steering main shaft 16 through a slide bearing (not shown) in the front-back direction of the paper surface of FIG. 1 (direction of arrow L and direction of arrow R in FIG. 2). Has been done.

Inside the steering housing 12,
An Oldham coupling 28 including a first rotating member 22, a second rotating member 24, and a third rotating member 26 provided between the first rotating member and the second rotating member is arranged. The first rotating member 22, the second rotating member 24, and the third rotating member 26 are each formed in a disc shape.

As shown in FIGS. 1 and 2, the first rotating member 22 is coaxially connected to the steering main shaft 16.

The third rotary member 26 has a first convex portion 2 which extends axially on the first rotary member 22 side and extends in the radial direction.
6A is provided, and the second protrusion 26B extends in the direction orthogonal to the protrusion 26A, passing through the axis on the second rotating member side.
Is provided.

The first rotating member 22 is provided with a first recess 22A which passes through the axial center and extends in the radial direction.
The first convex portion 26A of the third rotating member 26 is slidably engaged with the first concave portion 22A.

Further, the second rotary member 24 is provided with a second recess 24A passing through the axial center and extending in the radial direction. The second recess 24A has a second recess 24A of the third rotary member. Two
The convex portion 26B is engaged slidably.

As shown in FIG. 1, a movable housing 32 as an eccentric means is housed inside the steering housing 12 on the arrow F direction side. Movable housing 3
A ball bearing 30 is attached to 2.

A support shaft 31 is rotatably supported by the ball bearing 30, and a second rotating member 24 is coaxially connected to one end of the support shaft 31. That is, the second rotating member 24 is rotatably supported by the movable housing 32 via the ball bearing 30.

A slide shaft 34 is fixed to the end of the movable housing 32 on the arrow U direction side, and a slide shaft 36 is fixed to the end of the movable housing 32 on the arrow D direction side. The slide shaft 34 and the slide shaft 36 are orthogonal to the steering main shaft 16.

The slide shaft 34 and the slide shaft 36 are inserted into a slide bearing 38 provided in the steering housing 12, whereby the movable housing 32 is supported by the steering housing 12 so as to be slidable in the arrow U direction and the arrow D direction. Has been done.

A plurality of teeth 40 are formed on a part of the slide shaft 34 along the axial direction at a predetermined pitch.
A worm gear 42 meshes with the teeth 40.
The worm gear 42 is rotated by a motor 46 whose rotation is controlled by the control device 44. The control device 44
For example, a vehicle speed sensor or the like is connected to the.

A protrusion 48 as an engaging means is formed on the side surface of the steering rod 20 on the arrow D direction side, and a groove 50 is formed in the center of the protrusion 48. The third rotating member 26 of the Oldham's joint 28 is rotatably and slidably inserted in the groove 50 in the arrow U direction and the arrow D direction.

In this embodiment, when the steering wheel 14 is in the neutral state, the first rotating member 22 is
The first recess 22A is parallel to the steering rod 20. Further, the axis of the second rotating member 24 and the axis of the first rotating member 22 are set in an eccentric state in advance.

Next, the operation of this embodiment will be described with reference to FIGS. In the vehicle steering angle ratio variable steering device 10 of this embodiment, when the steering main shaft 16 is rotated by the operation of the steering wheel 14, the Oldham coupling 28 is rotated correspondingly. In the Oldham coupling 28, the shaft center of the first rotating member 22 and the shaft center of the second rotating member 24 are set in an eccentric state in advance, so that the third rotating member 26 has the steering main shaft 16 When it rotates, it swings. The tangential movement of the swinging third rotating member 26 is transmitted to the steering rod 20 via the protrusion 48, and the steered wheels of the vehicle are steered.

In this vehicle steering angle ratio variable steering device 10,
The stroke of the steering rod 20 corresponding to the turning angle of the steering wheel can be changed by the amount H (see FIG. 1) of the eccentricity between the axis of the first rotating member 22 and the axis of the third rotating member 26. . To change the eccentricity H,
This is performed by rotating the motor 46 and sliding the movable housing 32 in the arrow U direction or the arrow D direction.

Below, the steering wheel turning angle θ
An example in which is set to 45 ° will be described.

With the steering wheel 14 in the neutral state, as shown in the upper left of the drawing of FIG. 3, the movable housing 32 is moved relatively little in the direction of the arrow U, and the axis of the first rotating member 22 and the third rotation are rotated. When the amount of eccentricity H of the member 26 with respect to the shaft center is set to be relatively small, the steering wheel 14 is rotated clockwise by 4 as shown in the upper right of FIG.
The stroke S when cut by 5 ° is relatively small,
When the eccentric amount H is increased as shown in the lower left of FIG.
Turn the steering wheel 14 45 °
The stroke S when cut is greater than when the eccentric amount H is reduced.

That is, if the amount of eccentricity H is increased, the direction of the steered wheels can be largely changed with a small amount of steering operation, and if the amount of eccentricity H is decreased, the change in the direction of the steered wheels with respect to the steering operation becomes small.

For example, when the vehicle is traveling at a high speed, the eccentricity amount H is set small. As a result, the change in the direction of the steered wheels with respect to the steering operation is reduced, and the running stability can be improved.

On the other hand, when the vehicle is running at a low speed, the eccentric amount H is set to a large value. As a result, the change in the direction of the steered wheels with respect to the steering operation becomes large, the steering operation amount is small when the vehicle is put in the garage, and the garage is easily put in.

Since the vehicle steering angle ratio variable steering apparatus 10 of this embodiment is configured to only change the steering angle ratio, the neutral point of the steering wheel does not change.

The eccentricity H may be changed by the control device 44 by judging the running state of the vehicle (vehicle speed, acceleration / deceleration, lateral G, shift lever position, etc.), and switch operation by the driver. It may be changed by.

[0038]

As described above, the vehicle steering angle ratio variable steering system of the present invention utilizes the whirling caused by changing the eccentricity of the Oldham coupling as described above, and the whirling is performed in the axial direction of the output shaft. Since it is configured to perform steering by converting the movement into the movement of the vehicle, it is not necessary to separately use a separate component such as a joint unlike the conventional vehicle steering angle ratio variable steering device, and the number of components is small, and the configuration is It has an excellent effect that it becomes simple.

[Brief description of drawings]

FIG. 1 is a sectional view of a vehicle steering angle ratio variable steering system according to an embodiment of the present invention.

2 is a perspective view of the Oldham coupling shown in FIG. 1. FIG.

FIG. 3 is an explanatory diagram for explaining the movement of the Oldham coupling portion.

FIG. 4 is a cross-sectional view of a conventional vehicle steering angle ratio variable steering device.

[Explanation of symbols]

 10 Vehicle Steering Angle Ratio Variable Steering Device 16 Steering Main Shaft (Rotating Shaft) 22 First Rotating Member 24 Second Rotating Member 26 Third Rotating Member 28 Oldham Joint 32 Movable Housing (Eccentric Means) 48 Projecting Part (Means)

Claims (1)

[Claims] 1. A first rotating member, a second rotating member, and
An Oldham coupling including a third rotating member provided between the first rotating member and the second rotating member, and a steering operation connected to either one of the first rotating member and the second rotating member. And a rotation shaft that is driven to rotate according to the first rotation member and the other of the first rotation member and the second rotation member, and the amount of eccentricity between the first rotation member and the second rotation member is variable. And an eccentric means for engaging the third rotating member to take out a predetermined tangential movement of the third rotating member and transmit the tangential movement to an output shaft connected to a steering wheel of a vehicle. A steering angle ratio variable steering device for a vehicle, comprising: engagement means;