JPH02270616A - Suspension for steering wheel - Google Patents

Abstract

PURPOSE:To smoothly carry out the steering of wheels by providing a rotary damper whose vane is housed in an oil chamber in the connecting part of a suspension arm and a vehicle, so that it is positioned on the opposite side to the wheel with respect to the oscilating central axis of the arm. CONSTITUTION:A front suspension 1 is provided with upper and lower arms 2, 3 arranged nearly parallel to the direction of the width of a vehicle, and a wheel 7 is supported by the ends of respective arms 2, 3 via a wheel support 6. The base end part of the lower arm 3 is oscilatably supported by a supporting shaft 11 to a bracket 13 fitted to a vehicle frame. In this case, a rotary damper 16 is fitted to the base end part of the lower arm 3. The damper 16 is so constituted that it is provided with both a damper case 17 fitted to the lower arm 3 so as to be positioned on the opposite side to the wheel 7 with respect to the oscilating central axis of the arm 3, and a vane 18 integrally connected to the supporting shaft 11, and that the fan-shaped oil chamber 20 inside the damper case 17 is partitioned into upper and lower two chambers by a vane 18.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension used to support a vehicle body by the steering wheels, generally the front wheels, of a vehicle such as an automobile. This invention relates to a steering wheel suspension that uses a rotary damper that generates damping force.

(Prior Art) In automobiles, springs are used in suspensions to alleviate shocks transmitted from the road surface to the vehicle body via the wheels. In order to prevent resonance of the vehicle body caused by the spring, a damper is provided to damp vibrations. Generally, a cylindrical telescopic damper is used as the damper, but since such a damper is long, there is a problem in that the installation position etc. are restricted.

Therefore, Japanese Patent Application Publication No. 59-160609 and Japanese Patent Publication No. 58
As shown in Japanese Patent No. 55923, etc., it has been considered to use a rotary damper that generates a damping force in the rotational direction. This rotary damper consists of a damper case with an oil chamber and a vane that divides the oil chamber into two chambers and rotates relative to the damper case. The vane is provided between the suspension arm and the vehicle body in such a way that the center axis of swing of the supporting suspension arm coincides with the center axis of swing of the suspension arm, and the vane rotates relative to the damper case as the arm swings. It will be done like this. The two oil chambers partitioned by the vanes communicate with each other via an orifice, and resistance is provided to the flow of hydraulic oil in the oil chamber as the vanes rotate. Therefore, a damping force against the swinging of the suspension arm is generated.

By using such a rotary damper, it is possible to reduce the vertical dimension of the suspension.
Space efficiency can be increased.

As shown in the above-mentioned publication, a conventional rotary damper has a damper case having a circular cross section, and an oil chamber and a vane are provided on both sides of the damper case in the diametrical direction.

(Problem to be Solved by the Invention) By the way, in the case of a front suspension of a car, since the wheels are steered, it is necessary to ensure that the suspension does not interfere with the steering. In order to reduce this, the maximum steering angle of the wheel is required to be as large as possible.

However, when a conventional rotary damper having a damper case with a circular cross section is used in the front suspension, the damper case is disposed so that the center axis of the damper coincides with the swing center axis of the suspension arm. It also protrudes largely from the center axis of swing of the suspension arm toward the wheel. Therefore, when attempting to steer the wheels by a large angle, the wheels and the rotary damper will interfere with each other. That is, the maximum steering angle of the wheels is limited by the rotary damper.

The present invention has been made in view of such problems, and its purpose is to obtain a compact suspension for steered wheels that can sufficiently increase the steering angle while using a rotary damper.

(Means for Solving the Problems) In order to achieve this object, the present invention makes the rotary damper asymmetrical in that the oil chamber and vane are provided only on one side of the rotation center axis, and The chamber and the vane are arranged on the opposite side of the wheel with respect to the swing center axis of the suspension arm.

(Function) With this configuration, the rotary damper does not protrude significantly toward the wheel from the pivot axis of the suspension arm, so it does not interfere with wheel steering. Therefore, it becomes possible to ensure a large maximum steering angle.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

The figure shows an embodiment in which the present invention is applied to a front suspension of a front-wheel drive vehicle. Figures 1 and 2 are a plan view and a front view of the suspension, and Figures 3 and 4 are enlarged views of the main parts. They are a cross-sectional plan view and a cross-sectional front view.

As is clear from Fig. 1.2, this front suspension 1 is a wishbone type suspension,
It includes an upper arm 2 and a lower arm 3 as suspension arms. These arms 2 and 3 are arranged almost parallel to each other in the left and right direction of the vehicle body (left side in Figure 1), and their base ends on the center side of the vehicle body (right side in Figure 2) are arranged in the front and rear direction by the vehicle body. is supported so as to be able to swing around a horizontal axis. Further, a wheel support 6 is attached to its tip via upper and lower ball joints 4.5. A wheel 7, which is a steered wheel, is rotatably supported by a wheel support 6, and is rotationally driven by a drive shaft 8 connected via a constant velocity joint.

The wheel support 6 is provided with a knuckle arm 9 that projects rearward, and by driving the tie rod 10 connected to the knuckle arm 9 in the left-right direction of the vehicle body, the wheel support 6 is moved to the upper and lower ball joints 4. .5, and the wheels 7 are steered.

The lower arm 3 is longer than the upper arm 2, and its base end portion is relatively thick in the vertical direction. Also,
The base end portion of the lower arm 3 is made wider in the front and back direction, and has a pair of legs 3a, 3a separated from each other in the front and back. The leg portion 3a extends slightly toward the center of the vehicle body.

As shown in Fig. 3.4, the pair of legs 3a, 3a of the lower arm 3 is rotatable via a bearing 12.12 by a support shaft 11 installed horizontally in the longitudinal direction of the vehicle body. Supported. The support shaft 11 is fixed to a pair of brackets 13.13 attached to a cross member of the vehicle body. In this way, the lower arm 3 is placed on the horizontal support shaft 1.
The wheels 7 are connected to the vehicle body so as to be swingable up and down about the center axis of the wheels 7, and the wheels 7 are allowed to move up and down.

The support shaft 11 is shaped like a hollow vibrator, and a torsion bar 14 serving as a suspension spring is inserted through the inside thereof. The torsion bar 14 is arranged on the center axis of the support shaft 11, that is, on the swing center axis of the lower arm 3. One end of the anchor arm is fitted into a boss 15 of an anchor arm integrally connected to the lower arm 3 via serrations. Moreover, the other end is the support shaft 11
It extends rearward through the front end and is fixed to the vehicle body at a position sufficiently rearward from the front end. In this way, when the lower arm 3 swings in the vertical direction, the torsion bar 14 is twisted between its both ends.

A rotary damper 16 is provided between a pair of legs 3a, 3a at the base end of the lower arm 3.

As is clear from FIGS. 3 and 4, the damper 16 is composed of a damper case 17 attached to the lower arm 3 and a vane 8 integrally connected to the support shaft 1. The vane 18 is a single vane that extends relatively horizontally from the outer peripheral surface of the support shaft 11 toward the center of the vehicle body, that is, toward the opposite side from the wheels 7. Also,
The damper case 17 has an asymmetrical shape including a cylindrical portion 17a surrounding the outer surface of the support shaft 11 and a fan-shaped cylindrical portion 17b extending from the cylindrical portion 17a toward the center of the vehicle body. Cylindrical portion 1 of the damper case 17
A sealing member 19 is provided between the inner circumferential surface of 7a and the outer circumferential surface of the support shaft 11.
．． It is sealed by 19.

Lower arms 3 are provided on both end surfaces of the damper case 17.
A pair of leg portions 3a, 3a are tightly coupled, and the space between them is oil-tightly sealed.

Thus, inside the damper case 17, the fan-shaped cylindrical portion 17b, the support shaft 11, and the leg portions 3a, 3 of the lower arm 3 are included.
An oil chamber 20 surrounded by a is formed. The oil chamber 20 has a substantially fan-shaped cross-sectional shape centered on the central axis of the support shaft 11, and is located on the vehicle body center side with respect to the central axis of the support shaft 11, that is, the swing center axis of the lower arm 3, that is, the wheel 7. It is located on the opposite side.

The central angle of the fan-shaped cross section of the oil chamber 2.0 is relatively small;
The damper case 17 is prevented from protruding above and below the leg portion 3a of the lower arm 3.

Hydraulic oil is sealed inside the oil chamber 20. and,
The oil chamber 20 has two upper and lower chambers 20a,
It is divided into 20b. The vane 18 has two chambers 20a, 2 in its center via valves 21.21.
A pair of orifices 22, 22 are provided to communicate between the ob. Furthermore, rubber stoppers 23.degree. 23 are attached to both sides of the vane 18, which come into contact with the upper and lower walls of the damper case 17 when the vane 18 rotates largely relative to the damper case 17.

Furthermore, inside the damper case 17, a valve is placed closer to the center of the vehicle body than the oil chamber 20 to absorb volume changes due to temperature of the hydraulic oil in the oil chamber 20, to prevent cavitation occurring on the negative pressure side, and to prevent leakage. A reservoir 24 is provided for replenishing hydraulic oil.

Next, the front suspension 1 configured in this way will be explained.
The effect of this will be explained.

The weight of the vehicle body is transmitted to the wheels 7 via the upper arm 2 and lower arm 3. Therefore, these arms 2
．． 3 rotates relatively upward around its base end.

When the lower arm 3 rotates, a torsion bar 14 whose one end is fixedly connected to the lower arm 3 is twisted. The vehicle body is supported by the wheels 7 at a position where the elastic force of the torsion bar 14 and the vehicle weight are balanced.

During running, when the wheels 7 go over unevenness on the road surface, the load applied to the wheels 7 changes, so the amount of twist of the torsion bar 14 changes and the lower arm 3 swings in the vertical direction. Therefore, the wheels 7 move up and down relative to the vehicle body. In this way, the vehicle body is elastically supported by the wheels 7 via the torsion bars 14, and the impact transmitted from the wheels 7 to the vehicle body is absorbed.

When the lower arm 3 swings in the vertical direction in this manner, the lower arm 3 then swings in the opposite direction due to the elastic restoring force of the torsion bar 14, so that the lower arm 3 tends to vibrate. However, the vibrations are immediately damped by the rotary damper 16.

That is, when the lower arm 3 swings clockwise in FIG. 4, for example, the damper case 17 fixed to the arm 3 rotates integrally about its swing center axis. On the other hand, the vane 18 is fixed to the vehicle body via the support shaft 11. Therefore, when the arm 3 swings clockwise, the vane 18 rotates counterclockwise relative to the damper case 17 about the swing axis of the arm 3 . As a result, the volume of the chamber 20a above the vane air 8 of the oil chamber 20 in the damper case 17 is reduced, and the volume of the chamber 20b below is expanded. When the oil pressure in the upper chamber 2Oa rises in this way, one valve 21 opens,
The hydraulic oil in the upper chamber 2Oa flows through one orifice 22 to the lower chamber 20b. The orifice 22 provides resistance to the flow of hydraulic oil. Therefore, a damping force against the swinging of the lower arm 3 is generated.

A damping force is similarly generated when the lower arm 3 swings in the opposite direction.

In this way, the rocking vibration of the lower arm 3 is damped,
Vehicle body vibration is prevented.

In this way, in this front suspension 1, the torsion bar 14 is used as a spring, and the rotary damper 16 is used as a damper.
An extremely compact suspension with small vertical dimensions can be achieved. Moreover, the rotary damper 1
6, the vane 18 and the oil chamber 20 are provided only on the center side of the vehicle body with respect to the swing center axis of the lower arm 3, that is, the rotation center axis of the damper 16, that is, on the opposite side from the wheels 7. 16 hardly protrudes toward the wheel 7 side. Therefore, lower arm 3
The proximal end portion of the is bifurcated, and the branched leg portion 3
Even if the rotary damper 16 is arranged between a and 3a, its branching portion can be brought sufficiently close to the swing center axis of the lower arm 3, and the branching portion can be prevented from protruding largely toward the wheel 7 side. can do. As a result, it becomes possible to rotate the wheels 7 to the position shown by the imaginary line in FIG. 1, and the maximum steering angle can be made sufficiently large.

In addition, by bifurcating the base end portion of the lower arm 3 and supporting it at two points on the vehicle body via a pair of legs 3a, 3a separated from each other in the front and back, it is possible to support the wheels 7 in the front and rear direction. Support rigidity against loads can be sufficiently increased.

By arranging the rotary damper 16 between the legs 3a, 3a, the dead space can be used effectively, and space efficiency can be improved.

Furthermore, in this suspension 1, since the rotary damper 16 is provided on the long lower arm 3 side, even when the vertical movement stroke of the wheel 7 is large, the vane 18 of the damper 16 remains in position with respect to the damper case 17. It is only necessary to relatively rotate by a small angle. Therefore, the central angle of the fan-shaped cross section of the oil chamber 20 that accommodates the vane 18 can be made small, and the damper 16 as a whole can be made flat and small in vertical dimension. As a result, the rotation center axis of the damper 16 can be brought sufficiently close to the lower surface of the vehicle body, and the installation space can be further reduced. Further, since the rotary damper 16 is flat, the vane 18 can be extended relatively long toward the center of the vehicle body, and the area of the vane 18 can be increased. Therefore, even if the rotary damper 16 has only a single vane 18 and an oil chamber 20, sufficient damping force can be generated.

Since the damper case 17 of the rotary damper 16 is fixed to the lower arm 3 and the vane 18 is fixed to the vehicle body side, even when the lower arm 3 swings in the vertical direction, the damper case 17 is fixed to the lower arm 3. Therefore, the damper 16 is protected by the arm 3, and the damper 16 is prevented from being damaged by obstacles on the road.

In the above embodiment, the wishbone type front suspension 1 was explained as an example, but the present invention is not limited to this, and the present invention is not limited to this. The same can be applied to a suspension that supports wheels. In such a case, a coil spring may be used as the suspension spring.

Further, the present invention is not limited to a front suspension, but can also be applied to a rear suspension when the rear wheels are steered.

(Effects of the Invention) As is clear from the above description, according to the present invention, since a rotary damper is used as a damper for damping vertical vibration, a compact suspension with small vertical dimensions can be achieved. can do. and,
The rotary damper has a single vane and oil chamber,
Since they are arranged on the opposite side of the wheel with respect to the central axis of swing of the suspension, suspension parts such as dampers can be prevented from protruding significantly toward the wheel. Therefore, it is possible to prevent interference between the wheels and the suspension components even when the wheels are steered through a large angle, and it is possible to obtain a suspension for a steered wheel that can allow large angle steering.

Furthermore, since the rotary damper does not protrude significantly toward the wheel, the degree of freedom in designing the suspension arm and the like increases, and it is therefore possible to obtain a steering wheel suspension with excellent suspension characteristics.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of a steering wheel suspension according to the present invention, FIG. 2 is a front view of the suspension, and FIG. 3 is a view of the suspension seen from the line ■-■ in FIG. FIG. 4 is an enlarged sectional front view of the rotary damper portion of the suspension taken along line IV-IV in FIG. 1. FIG. 1...Front suspension (steering wheel suspension) 3...Lower arm (suspension arm) 7...
Wheel (steering wheel) 9...knuckle arm 11...
Support shaft 14...Torsion bar 16...
Rotary damper 17... Damper case 18... Vane 20... Oil chamber Fig. 2

Claims (3)

[Claims] (1) A suspension arm whose base end is connected so as to be swingable around an axis substantially horizontal to the vehicle body, and a wheel to be steered is attached to the distal end, and a suspension arm provided at the connection portion between the suspension arm and the vehicle body; When the arm swings,
A suspension comprising: a rotary damper that generates a damping force in the swinging direction of the suspension arm by rotating a vane that divides an oil chamber in the damper case into two chambers relative to the damper case; The rotary damper has an oil chamber and a vane only on one side of its rotational center axis, and the oil chamber and vane of the rotary damper are oriented with respect to the swinging center axis of the suspension arm. A suspension for a steered wheel, wherein the rotary damper is arranged so as to be located on the opposite side of the wheel. (2) The steering wheel suspension according to claim 1, wherein a torsion bar is fixed to the suspension arm, and the torsion bar is disposed on the rotation center axis of the rotary damper. (3) The steering wheel suspension according to claim 1, wherein a damper case of the rotary damper is fixed to the suspension arm, and a vane of the damper is fixed to the vehicle body.