JPH0353145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a vehicle steering system that steers both the front wheels and the rear wheels.

The present applicant has previously provided a vehicle steering device in which front wheels and rear wheels can be steered by steering operation of a steering wheel. Basically, such a device connects the front wheel steering mechanism and the rear wheel steering mechanism with a linkage member such as a linkage shaft, and moves the rear wheels in the same direction as the front wheels by operating a small steering angle of the steered wheels. In addition, a steering angle function generating mechanism is configured to steer the vehicle in the opposite direction in the case of a large steering angle operation, or to return the steering angle of the rear wheels to zero in the latter case.

By the way, in this type of vehicle, the rear wheels are independently suspended, and the lower arms that make up the rear wheel suspension mechanism may be lengthened depending on the suspension characteristics. In this case, the bearings of the left and right lower arms are placed near the center line of the vehicle body.
Therefore, the tie rods for steering the left and right rear wheels are also disposed opposite to each other near the center line of the vehicle body, so it is desirable to make the rear wheel steering mechanism more compact, especially in the vertical direction from the viewpoint of the vehicle body structure.

Furthermore, it would be even more preferable if a vibration isolation structure could be realized that satisfies the above requirements and prevents vibrations applied to the rear wheels from being transmitted to the vehicle body via the rear wheel steering mechanism.

The present invention has been made to rationally match the above, and its purpose is to rubber mount the shaft member of the rear wheel steering mechanism, which is connected to the front wheel steering mechanism via a linkage member, on the vehicle body. A vibration isolation structure is constructed on the lever part, and the arm member is connected to a joint member that is loosely fitted to the crank pin of the crank part provided on the shaft member and connects the left and right rear wheel steering tie rods. By pivoting the arm member to a link member suspended from the vehicle body, each component of the rear wheel steering mechanism can be arranged compactly without taking up space in the vertical direction, and furthermore, the arm member and the link member,
A rubber bushing is interposed in each pivot point between the link member and the vehicle body to realize a vibration-proofing structure in such a part, and to provide a steering device for a vehicle which has an excellent vibration-proofing effect in combination with the above-mentioned vibration-proofing structure. It is in.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that FIG. 1 is an explanatory plan view of a four-wheeled vehicle equipped with the steering device of the present invention, and FIGS.
The figures are a side view and a rear view, and FIG. 4 is an enlarged perspective view showing the basic configuration of the main parts according to the present invention.

The steering rotation of the steering wheel 1, which is a steering wheel, is converted to the left and right movement of the tie rods 4, 4 for steering the front wheels 3, 3 via a rack-and-pinion type steering gear 2 equipped with power steering. Knuckle arms 5, 5 connected to the outer ends of
The front wheels 3, 3 are also steered by this rotation.

A linkage member 6 is connected to approximately the center of the steering gear 2, and a linkage shaft 9 is extended to the rear of the vehicle body via a universal joint 8 to a pinion shaft 7 that easily meshes with it, and is further extended to the rear via a universal joint 10. Ring 11,1
A shaft member 12 constituting one steering mechanism is connected.

The shaft member 12 is disposed on the vehicle body center line with its rear part downwardly disposed, and a crank part 13 is provided at its rear end. The pin 14 is shaped to protrude rearward. The shaft member 12 is inserted and supported within a shaft collar 16 that is fixedly integrated with a rear wheel lower arm bracket 15 provided on a cross member of the vehicle body frame.

That is, as shown in FIG. 5, between the shaft collar 16 fixed to the bracket 15 and the shaft holder 17 of the shaft member 12 supported within this 16, there are two front and rear parts as shown in FIG. Rubber bushes 18 and 19 are interposed, and the shaft holder 17 is press-fitted into the shaft collar 16 via these rubber bushes 18 and 19. In this way, the shaft member 12 is rubber-mounted to the vehicle body and is therefore supported in a floating manner.

5 and 6, the direction in which the cross section of the shaft collar 16 is shown is reversed.

A joint member 20 having an approximately inverted T shape in the front is loosely fitted into the crank pin 14 of the crank portion 13 provided on the shaft member 12 with its upper part 21, and protrusions 2 forming lower portions on both left and right sides of this joint member 20.
Rear wheel steering tie rods 23, 23 are provided with ball joints 24, 24 on the upper surfaces 22a, 22a of the wheels 2, 22, respectively.

On the other hand, a link bracket 25 is fixedly hung down from the rear side of the joint member 20 on one side of the floor panel of the vehicle, and a link member 26 is attached to this 25.
is suspended from a pivot. An arm member 27 is pivotally attached to the lower part of the link member 26.
is formed sufficiently long beyond the center line of the vehicle body, and both left and right protrusions 22 of the joint member 20,
The tip portion 27a of the arm member 27 is fixed to the rear surface portions 22b, 22b of the arm member 22 with two bolts 28, 28. As a result, the joint member 20 performs a combined rocking motion of vertical and horizontal movements in conjunction with the crank movement of the crank pin 14.

And link member 26 and link bracket 25
A rubber bushing 29 is interposed at the pivotally connecting portion between the link member 26 and the arm member 27, and a rubber bushing 30 is also interposed at the pivotally connecting portion between the link member 26 and the arm member 27.

That is, as shown in FIG. 7 (cross-sectional view taken along the line 7-7 in FIG. 4), the front and rear hanging pieces 25 of the link bracket 25, which has a horizontal U-shaped cross section, are fixed to the floor panel of the vehicle body.
The upper part of the link member 26 faces between a and 25b, and the link member 26 is pivotally attached to the link bracket 25 with a bolt and nut 33 via a rubber bush 29 that is press-fitted and baked between the large-diameter and small-diameter cylinders 31 and 32. Therefore, it is suspended from the vehicle body in an elastic manner. Furthermore, the lower part of the link member 26 is exposed between the front and rear pieces 27b and 27c forming one end of the arm member 27,
Similarly to the above, the arm member 27 is connected to the link member 2 with the bolt/nut 36 via the rubber bush 30 which is press-fitted and baked between the large diameter and small diameter cylinders 34 and 35.
6, and thus the arm member 27 is also in an elastically supported state.

In the figure, 37 is a knuckle arm connected to the outer end of the tie rod 23 for steering the rear wheels, and 38 is a lower arm for the rear wheels.

Next, the operation of the above steering system will be described.

First, when the steering wheel 1 is in the neutral position when the vehicle is traveling straight, the crank portion 13 is connected to the crank pin 1.
For example, it is in a vertical state with 4 facing downward.

For example, when steering wheel 1 is steered to the right, front wheel 3
is similarly steered to the right, and the shaft member 12 is rotated to the right (clockwise) as seen from the rear of the vehicle via the linkage member 6 consisting of the pinion 7 and linkage shaft 9 led out from the steering gear 2. As a result, the crank pin 14 of the crank portion 13 similarly rotates clockwise, and the joint member 20 loosely fitted onto the pin 14 first swings to the left. Therefore, the tie rods 23, 23 connected to both the left and right protrusions 22, 22 of the joint member 20, which forms a substantially inverted T-shape from the front, move to the left, and the knuckle arm 3
7 and 37 rotate clockwise, and the rear wheel 11 is steered to the right together with the front wheel 3.

The right steering amount of the rear wheel 11 is maximum when the crank pin 14 becomes horizontal to the left, and thereafter the joint member 20 swings to the right until the pin 14 becomes vertically upward. The right steering amount of the wheel 11 is gradually reduced to zero.

When the pin 14 further cranks clockwise, the joint member 20 swings further to the right from the neutral position, and the rear wheel 11 then moves to the left in the opposite direction to the front wheel 3 until the pin 14 becomes horizontal to the right. The steering is performed with a gradually increasing amount of steering.

Then, the joint member 20 swings leftward until the pin 14 reaches the downward vertical position again, exceeding the above-described state in which the left steering amount is at its maximum.
The left steering amount gradually decreases to zero. The left steering is done in the same way.

In this way, small steering angle operation of the steering wheel 1 (up to 180° with the neutral position of the crank pin 14 as 0°)
In this case, the rear wheels 11 can be steered in the same direction as the front wheels 3, and in the case of a large steering angle operation (from 180 degrees to 360 degrees), it can be steered in the opposite direction, or in the latter case, the steering angle of the rear wheels 11 can be returned to zero. A steering angle function generation mechanism that can be used has been constructed.

Moreover, the vehicle steering system of the present invention capable of generating the above-mentioned steering angle function uses a small-sized joint member 20 that is installed upright on the crank portion 13 and loosely fitted to the crank pin 14 that is eccentric to the shaft member 12. Projections 22, 22, which have a substantially inverted T-shape from the front, loosely fit into the pin 14 with the upper part 21, and constitute the lower left and right sides of the joint member 20.
Rear wheel steering tie rods 23, 23 are connected to the upper surface parts 22a, 22a, respectively, and the protrusions 22, 22
An arm member 27 is tied to the rear surface portions 22b, 22b, and the arm member 27 is pivotally supported by a link member 26 hanging biased toward the rear part of the joint member 20 on one side of the floor panel of the vehicle. It was configured as follows.

Therefore, the lower arm 38 that constitutes the rear wheel suspension mechanism
is made longer depending on the suspension characteristics, so the bearings of the left and right lower arms 38, 38 are placed near the center line of the vehicle body,
Along with this, tie rods 23, 23 for rear wheel steering
They can also be compacted and placed facing each other near the centerline of the vehicle body, and compactness in the vertical direction, which is particularly desirable from the standpoint of vehicle body structure, can be achieved.

Moreover, since the shaft member 12, link member 26, and arm member 27 supported by the vehicle body are mounted or pivotally supported through rubber bushings 18, 19, 29, and 30, respectively, vibrations applied to the rear wheels 11, 11, etc. This can prevent vibrations from being transmitted to the vehicle body through the rear wheel steering mechanism, making it an excellent steering device with excellent anti-vibration measures.

In particular, since the link member 26 is suspended from the floor panel of the vehicle body, it is desirable that the link member 26 be elastically supported at this portion, and it is possible to effectively meet the demand that the spring constant be as low as possible.

By the way, the joint member 20 according to the present invention is constituted by a small component having an approximately inverted T shape from the front, and an arm member 2 is a member that ensures the rocking of the joint member 20.
7 is pivotally supported from the vehicle body to the joint member 20 and a link member 26 that is hung from one side with a bias toward the rear, so the joint member 20 requires great strength.
It is possible to reliably achieve downsizing, and a large load is not applied to the arm member 27, which is a large component.
Therefore, it is possible to achieve a thinner wall without increasing the strength, and the weight of the entire device can also be reduced.

As is clear from the above description, according to the present invention, each component of the rear wheel steering mechanism can be arranged in a compact manner without taking up space in the vertical direction, and an excellent vibration damping effect can be exhibited. It has many advantages such as being able to

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory plan view of a vehicle equipped with the steering system of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a rear view of the same, and FIG.
The figure is an enlarged perspective view showing the basic configuration of the main parts according to the present invention, FIG. 5 is a vertical sectional side view of the shaft collar attachment part, FIG. 6 is a partially cutaway side view of the shaft member assembly part, and FIG. It is a sectional view taken along the line 7-7 in FIG. 4. In the drawing, 1 is a steering wheel, 3 is a front wheel, 11 is a rear wheel,
12 is a shaft member, 13 is a crank portion, 14 is a crank pin, 18 and 19 are rubber bushings, 20
2 is a joint member, 23 is a rear wheel steering tie rod, 26 is a link member, 27 is an arm member, 2
9 and 30 are rubber bushings.

Claims (1)

[Claims] 1. In a vehicle steering device in which the rear wheels are steered together with the front wheels by the steering operation of the steering wheel, a shaft member that rotates in conjunction with the steering wheel is rubber-mounted on the vehicle body, and the shaft member is provided on the shaft member. An arm member is connected to a joint member that is loosely fitted to a crank pin that stands on the crank part and is eccentric to the shaft member, and that connects left and right rear wheel steering tie rods, and a rubber bush is interposed between the arm member and the joint member. A steering device for a vehicle, characterized in that the link member is pivotally attached to a link member, and the link member is pivotally suspended from a vehicle body via a rubber bushing.