JPH05201216A - Suspension for vehicle - Google Patents

Abstract

PURPOSE:To prevent a worsening of return of a steering wheel at the time of its operation by providing a connecting link for transmitting displacement of an assembly at turning of the steering wheel that a front part of a wheel is oriented inward in the car width direction as a rotary motion of a suspension damper corresponding to the direction for displacing an outer end in the car width direction of an upper arm to the rear. CONSTITUTION:A lower set point KD of a virtual king pin axis KP is constituted by an extended intersection outside a car body between a front lower arm 1 and a rear lower arm 2, and an upper set point KU of the virtual king pin axis KP is constituted by a ball joint 23 for an upper arm 21 for connecting a suspension damper 3 to a knuckle 6. And by displacement of the rear lower arm 2 for turning of an outer wheel, the suspension damper 3 is rotated around the axis through the connecting link, and the set point KU is displaced to the rear. By this, a reduction amount of a caster trail is reduced, and deterioration in returning of the steering wheel can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suspension device.

[0002]

2. Description of the Related Art A wheel supporting member for a steered wheel, that is, a knuckle is supported by a vehicle body through at least a lower arm so as to be vertically swingable. The wheels attached to the wheel support member are required to be set so as to have a predetermined wheel alignment, and the kingpin shaft is one of the important factors for determining the wheel alignment.

That is, when viewed from the front (rear) of the vehicle body, the downward extension line of the kingpin shaft is located slightly outward of the widthwise center line of the wheel body so that the wheel may move when braking. It is desired to be in. Further, the kingpin shaft is located slightly inward of the widthwise center line of the wheel inward of the vehicle body at the rotation center height position of the wheel so that the wheel becomes a toe-in when receiving a driving force. It is desirable to do. Such a setting is strongly required especially for the front suspension of an FF vehicle equipped with an engine that generates a large torque.

As can be understood from the above description, the kingpin shaft is required to be set slightly inclined so that it is located toward the outer side of the vehicle body as it goes downward when viewed from the front of the vehicle body. For example, in a strut suspension, the connecting portion between the lower arm and the wheel supporting member constitutes the lower set point, and the connecting portion between the suspension damper and the wheel supporting member constitutes the upper set point, and both of the above setting points are set. The line connecting the points is the kingpin axis.

In order to satisfy the above-mentioned demand for tilting of the kingpin shaft, the lower setting point, that is, the outer end of the lower arm in the vehicle width direction is deeply extended to the inner diameter portion of the wheel, that is, greatly extended outward in the vehicle width direction. However, from the standpoint of preventing interference with break disks, etc.
It is practically difficult to extend the frame to the outer side in the circumferential direction of the vehicle.

In order to position the lower set point of the kingpin shaft to the outer side in the vehicle width direction more sufficiently, the lower arm is divided into a front lower arm and a rear lower arm, and the wheel support member and the lower arm are arranged. A so-called double-pivot type suspension having two connecting portions with the frame has been proposed (see Japanese Patent Publication No. 58-42042). That is, the lower set point of the virtual kingpin axis is to be configured by the intersection point of the front lower arm and the rear lower arm that extends outward of the vehicle body. More specifically, the line connecting the vehicle body side connecting portion of the front lower arm and the wheel supporting member side connecting portion and the line connecting the vehicle body side connecting portion of the rear lower arm and the wheel supporting member side connecting portion By arranging the intersection point on the outer end side in the vehicle width direction with respect to the connecting portion of each lower arm with respect to the wheel support member, the intersection point is substantially configured as a lower set point of the virtual kingpin axis. is there.

[0007]

However, in the structure in which the virtual kingpin shaft is formed by dividing the lower arm into the front lower arm and the rear lower arm, the steering wheel is turned when the steering wheel is steered. It has been found that the caster trail of the wheel on the side of the turning outer wheel becomes smaller and the return of the steering wheel becomes worse.

Explaining this point in detail, when the steering wheel is turned, the outer wheel is steered about the virtual kingpin axis when it is in a straight traveling state. When this steered,
The connecting portions of the front lower arm and the rear lower arm to the wheel supporting member are displaced relatively rearward as compared with the straight traveling state, whereby each lower arm swings rearward of the vehicle body. As a result, the lower set point of the virtual kingpin axis is displaced rearward, resulting in a smaller caster trail and poorer handle return. In particular, the turning outer wheel is the wheel on the side that substantially controls the return of the steering wheel due to the movement of the load on the vehicle body, so the steering wheel return wheel is operated at high speed and at a large steering angle such as during sports driving. The deterioration was considerable, and in extreme cases, the wheels would be steered more than intended.

The present invention has been made in consideration of the above circumstances, and in which the front lower arm and the rear lower arm constitute the lower set point of the virtual kingpin shaft, the handle is returned. An object of the present invention is to provide a vehicle suspension device that can reduce deterioration.

[0010]

To achieve the above object, the present invention has the following configuration. That is, a wheel supporting member for steered wheels is swingably supported in a vertical direction on a vehicle body via a front lower arm and a rear lower arm, and the vehicle body including the front lower arm and the rear lower arm. In a vehicle suspension device in which a downward set point of a virtual kingpin axis is constituted by an outward extension intersection, a suspension damper and the wheel support member are connected to each other, and the suspension damper is vertically swingable with respect to the suspension damper. The suspension damper is connected to an assembly of an upper arm that can rotate integrally with the suspension damper around the axis of the suspension damper and the front and rear lower arms and a wheel support member. The displacement of the assembly that occurs when the wheel is steered so that the front portion of the wheel faces the inner side in the vehicle width direction is described as follows. A connecting link transmitting a rotational movement of the suspension damper corresponding to the direction of displacement rearward, a configuration equipped with.

The lower end of the suspension damper can be connected to the assembly, for example, the front lower arm, through a ball joint.

[0012]

According to the present invention, the outer end of the steered turning outer wheel for the turning outer wheel in the vehicle width direction is displaced rearward, and as a result, the connecting portion between the upper arm and the wheel supporting member, that is, the virtual portion, is virtual. The upper set point of the kingpin axis is displaced rearward,
Compared to the case where the upper set point is not displaced rearward, the reduction amount of the caster trail is smaller, and the deterioration of the steering wheel return is prevented. Further, the camber control has a high degree of freedom by providing the upper arm.

By connecting the suspension damper to the front lower arm via the ball joint as described in claim 4, the supporting rigidity of the suspension damper is increased and the suspension damper is supported about its axis. The suspension damper, that is, the upper arm can be smoothly rotated. Preferred embodiments of the invention and their advantages will be apparent from the description of the examples below.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings, as an example in the case of being applied to a front suspension of an FF vehicle. 1 to 4, 1 is a front lower arm, 2 is a rear lower arm, and 3 is a suspension damper.

The front lower arm 1 extends substantially parallel to the vehicle width direction, and its inner end in the vehicle width direction is rotatably attached to the vehicle body via a bush 4, and its rotation axis is approximately the front and rear of the vehicle body. Aligned with the direction. An outer end portion of the front lower arm 1 in the vehicle width direction is attached to a lower end portion of a knuckle 6 as a wheel supporting member via a ball joint 5.

The lower end of the suspension damper 3 is connected to the intermediate portion of the front lower arm 1 via a mounting member 7. This mounting member 7 is used for the suspension damper 3
A cylindrical portion 7a fitted and integrated with the outer periphery of the lower end of the cylindrical portion 7a.
It has a pair of leg portions 7b which are bifurcated in the front-rear direction from the lower end portion of a. The pair of legs 7b forming a fork shape are connected to the front lower arm 1 via a bush 8 with the front lower arm 1 sandwiched in the front-rear direction. This bush 8 is, as will be described later, substantially a ball.
The suspension damper 3 is swingable in the vehicle width direction and is made up of a suspension joint 3.
Is rotatable about the axis. A drive shaft (not shown) is inserted between the pair of legs 7b.

The rear lower arm 2 is set so as to have a substantially L shape as shown in FIG. After this, the inner end of the lower arm 2 in the vehicle width direction is connected to the vehicle body via a bush 10, and the axis of rotation thereof substantially coincides with the vehicle longitudinal direction. Further, from the vicinity of the middle of the rear lower arm 2, a slight inclination is set so as to gradually move forward toward the outer side in the vehicle width direction, and the outer end in the vehicle width direction forms the ball joint 11. The ball joint 11 is connected to the lower end of the knuckle 6 via the knuckle 6, and the position of the ball joint 11 is located right after the ball joint 5 for the front lower arm 1.

The mounting member 7, that is, the suspension damper 3 and the upper end portion of the knuckle 6 are connected to each other via an upper arm 21. The upper arm 21 has a substantially U-shape that opens toward the inner side of the vehicle body and holds the tubular portion 7a of the mounting member 7 in the front-back direction.
It is connected to the mounting member 7 so as to be swingable in the vertical direction, that is, rotatable about an axis extending substantially in the front-rear direction of the vehicle body.

The upper arm 21 is rotated integrally with the suspension damper 3 in a substantially horizontal plane as the suspension damper 3 is rotated about its axis. The outer end portion of the upper arm 21 in the vehicle width direction is provided with a knuckle 6 via a ball joint 23.
Is connected to the upper end of. Such an upper arm 2
1 is set to have a sufficiently shorter length in the vehicle width direction than the lower arms 1 and 2.

As shown in FIG. 2, the line connecting the center of the bush 4 for the front lower arm 1 and the center of the ball joint 5 is L1, and the center of the bush 10 of the rear lower arm 2 is the same. The line connecting the center of the ball joint 11 is L2. The lines L1 and L2 are connected to the ball joints 5 and 1, respectively.
They intersect on the outer side in the vehicle width direction than 1, and the intersection is indicated by KD.

A line connecting the intersection KD and the center KU of the ball joint 23 for the upper arm 21 constitutes a virtual kingpin axis KP (see FIG. 3). That is,
The center of the lu-joint 23 constitutes the upper set point of the virtual kingpin axis KP, and the intersection KD constitutes the lower set point of the virtual kingpin axis.

The attachment member 7, that is, the suspension damper 3 and the rear lower arm 2 are connected by a connecting link 25. The connecting link 25 is located on the outer side in the vehicle width direction with respect to the suspension damper 3 and extends substantially in the front-rear direction, but is slightly inclined so as to be gradually located on the outer side in the vehicle width direction toward the rear. There is. And
The front end of the connecting link 25 is connected to the front leg 7b via a ball joint 26, and the rear end of the connecting link 25 is connected via a ball joint 27 to the ball joint 1.
It is connected to the rear lower arm 2 in the vicinity of 1.

The connecting link 25 displaces the rear lower arm 2 rearward at the time of steering such that the front part of the wheel faces the inner side in the vehicle width direction, that is, when the wheel becomes a turning outer wheel. 2 is transmitted as a clockwise rotational movement of the suspension damper 3 in FIG. 2, and its connecting position is selected so that such transmission is effectively performed. Of course, the above clockwise rotation of the suspension damper 3
A ball joint 2 which serves as an outer end portion in the vehicle width direction of the upper arm 21, that is, an upper set point KU of the virtual kingpin axis KP.
3 is moved to the rear.

The bush 8 is constructed as shown in FIG. The bush 8 includes an outer cylinder 31 fitted in the mounting hole 1a of the front lower arm 1, an inner cylinder 32 into which a shaft to which the leg portion 7b is mounted is inserted, and both cylinders 31 and 32. The elastic material 33 such as rubber is filled in the gap.

A spherical portion 32a is formed on the outer peripheral surface of the inner cylinder 32, and the spherical portion 32a is connected to the outer cylinder 31 via an elastic member 33. As a result, the mounting member 7, that is, the suspension damper 3 is allowed to move in a direction of 360 degrees with respect to the front lower arm 1, and the bush 8 rotates about the axis of the front lower arm 1 as well as the suspension damper. It is also possible to rotate by a substantial angle around the substantially axis line of 3.

The operation of the present invention configured as described above will be described with reference to FIGS. 6 and 7. In the following description, reference symbol W is a wheel and O is a rotation center of the wheel. First,
In FIG. 6, the state of the wheel W1 and the lower arms 1 and 2 when the wheel W is in a straight traveling state is shown by a solid line,
The lower set point of the virtual kingpin axis KP is indicated by KD.
Note that FIG. 8 is exaggerated for easy understanding.

The state of the wheel W, which is the outer wheel for turning when steered from this straight traveling state, is shown by a broken line. During this steering, the wheel W is steered about the kingpin axis KP in the straight traveling state, while the steering position of the lower arms 1 and 2 with respect to the knuckle 6, that is, the wheel, is caused by the steering of the wheel W. -Le joints 5, 11 move backwards.

When the ball joints 5 and 11 move rearward, the states of the lower arms 1 and 2 when the lower arms 1 and 2 swing rearward about the vehicle body side connecting portion are described. The lower set point of the virtual kingpin axis at this time is KD1 and is displaced rearward from the original lower set point KD, and the caster trail is considerably reduced.

On the other hand, in FIG. 7, when the wheels W are viewed from the outside of the vehicle body, the virtual kingpin axis KP is set so as to be positioned forward as it goes downward, and the caster tray when the wheels are in a straight traveling state. Is indicated by T1.
Now, while the upper set point KU of the virtual kingpin axis KP is not displaced, the lower set point KD is displaced rearward and the above-mentioned KD
If the position is set to 1, the caster trail becomes small as indicated by T2, and the return of the steering wheel when turning is poor.

On the other hand, in the case of the present invention, the upper arm 21 for the wheel W on the turning outer wheel side at the time of turning.
Ball joint 23, that is, virtual kingpin axis KP
The upper set point KU of is KU1 displaced rearward as already described. As a result, the virtual kingpin axis is KU1.
And KD1 are connected, and the caster trail at this time is indicated by T3. And this T3 is the above-mentioned T2
The deterioration of the steering wheel return caused by the reduction of the caster trail is suppressed.

FIG. 8 shows another embodiment of the present invention.
The same components as those of the above-described embodiment are designated by the same reference numerals, and the duplicated description will be omitted. This FIG. 8 corresponds to FIG. 2 and is shown as a skeleton diagram for simplification.

This embodiment differs from the above-mentioned embodiment only in the mounting position of the connecting link. That is, the connection link 55 corresponding to the connection link 25 in the above embodiment.
Are arranged so as to pass through the suspension damper 3 on the outer side in the vehicle width direction, and are set to be inclined so as to be located on the inner side in the vehicle width direction toward the rear. The rear end of the connecting link 55 is connected to the rear leg 7b via the ball joint 56, and the front end of the connecting link 55 is connected to the front end of the knuckle 6 via the ball joint 57 ( The ball joint 5 is connected to the front position).
The action itself of the connecting link 55 is the same as that of the connecting link 25 in the above-mentioned embodiment, and therefore its explanation is omitted.

Although the embodiments have been described above, the present invention can be similarly applied to a rear wheel suspension, particularly for a so-called 4WS vehicle in which rear wheel steering is performed. Also,
In the embodiment, a so-called negative camber having a negative scrub radius is shown, but the same applies to a zero scrub or positive camber. Of course, it can be applied not only for the drive wheels but also as a suspension for the driven wheels.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view showing front and rear lower arm portions.

FIG. 3 is a rear view of the lower arm portion as viewed from the rear.

FIG. 4 is a side view of front and rear lower arms as viewed from the inside of the vehicle body.

FIG. 5 is a cross-sectional view showing an example of a bush used in a connecting portion between a suspension damper and a front lower arm.

FIG. 6 is an explanatory view showing a manner in which a lower set point of a virtual kingpin shaft for a turning outer wheel is displaced rearward.

FIG. 7 is an explanatory view for explaining the influence of the present invention on the change of the caster trail while comparing the operation of the present invention with the conventional one.

FIG. 8 shows another embodiment of the present invention.
Skeleton diagram corresponding to.

[Explanation of symbols]

 1: Front lower arm 2: Rear lower arm 3: Suspension damper 6: Knuckle (wheel support member) 7: Mounting member 21: Upper arm 23: Ball joint 25: Connection link 55: Connection link KP: Virtual Kingpin axis KU: Upper set point KD: Lower set point KU1: Upper set point during steering (invention) KD1: Lower set point during steering T2: Castor trail (conventional) T3: Castor trail (present invention) )

Claims (4)

[Claims] 1. A wheel support member for steered wheels is supported by a vehicle body through a front lower arm and a rear lower arm so as to be vertically swingable, and the front lower arm and the rear lower arm are supported. In a vehicle suspension device in which a virtual kingpin axis lower set point is configured by an intersection point on the outside of the vehicle with, a suspension damper and the wheel support member are connected,
An upper arm which is swingable in the vertical direction with respect to the suspension damper and is capable of integrally rotating together with the suspension damper around a substantially axial line of the suspension damper, and the front and rear lower arms and wheel supports. The suspension damper is connected to an assembly with a member, and the displacement of the assembly that occurs during steering such that the front portion of the wheel faces the inner side in the vehicle width direction, the vehicle width of the upper arm A suspension device for a vehicle, comprising: a connection link that transmits as a rotational movement of the suspension damper corresponding to a direction in which an outer end portion in the direction is displaced rearward. 2. The connection link according to claim 1, wherein the connecting link is arranged so as to pass through an outer side of the suspension damper in the vehicle width direction, and the outer ends of the suspension damper and the rear lower arm in the vehicle width direction. The one that connects with. 3. The connection link according to claim 1, wherein the connection link is arranged so as to pass through an outer side in the vehicle width direction of the suspension damper, and connects the suspension damper and a front portion of the wheel support member. thing. 4. The front damper according to claim 1, wherein the lower end portion of the suspension damper is the front lower
It is connected to the frame via a ball joint.