JPH05201348A - Rear axle of a car - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the self-steering state of the rear axle of a vehicle, that is, the running characteristics of the vehicle. A rear wheel 1 of an automobile rear axle according to the present invention is pivotally attached to a vehicle body 3 via a guide arm 21 fixed to a stub shaft that determines a rotation direction of the rear axle. The bearings 5 on the vehicle body side of both guide arms 21 are slidable relative to the vehicle body 3 in order to affect the self-steering state, that is, the running characteristics of the vehicle. The bearings are fixed to a bearing support 6 which is rotatably supported by the vehicle body 3 at a distance from each other.
The axis of rotation 8 of the bearing support lies in at least a substantially vertical longitudinal plane of the vehicle and in this longitudinal plane the actuator 7
Is adjustable between at least a substantially vertical direction and at least a substantially horizontal direction. Both bearings 5,
They are provided at substantially the same distance from the rotation axis 8 of the bearing support 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear axle of an automobile in which rear wheels are pivotally mounted on a vehicle body via guide arms fixed to stub shafts that determine the rotation direction of the rear wheels.

[0002]

BACKGROUND OF THE INVENTION Wheel suspensions on the rear axle of a vehicle so that the rear wheels can be steered at least to a limited extent in order to improve the self-steering condition, that is to say the driving characteristics of the motor vehicle, in particular depending on the driving. It is known to form a device.

In particular, the following automotive rear axle is known, for example from DE-A-3425730. That is, the rear wheels are pivotably attached to the vehicle body via the stub shaft fixed guide arms that determine the rotation direction, respectively, and the vehicle body side bearings of the stub shaft fixed guide arms are supported by a common actuator. , Depending on the driving parameters of the vehicle, for example depending on the steering turning angle of the front wheels, is slidable relative to the vehicle body, whereby an appropriate steering turning angle of the rear wheels is performed like kingpin steering. The rear axle of a car is known.

In the case of this known rear axle, the rear wheel guide arm fixed to the stub shaft is formed as a vertical arm that is oriented at least substantially forward in the vehicle longitudinal direction. The free end of the vertical arm on the vehicle body side is supported by the cross beam.
The cross girder itself is supported by the vehicle body transversely to the traveling direction depending on the steering turning angle of the front wheels. The lateral sliding of the cross beam is performed through a rubber bearing which is soft in the lateral direction and relatively hard in the vertical direction with respect to the traveling direction. This rubber bearing connects the cross girder and the vehicle body.

At the height of the axle, at least one lateral arm is also pivotally attached to the rear end of the guide arm fixed to the stub axle. The other end of this lateral arm is pivotally attached to the vehicle body. In the case of this known motor vehicle rear axle, the lateral sliding of the cross girder, and thus the steering turn of both rear wheels, is effected by a mechanical actuating rod operated by the steering rod of the steerable front wheels or, for example, on the cross girder. It is performed by a hydraulic operation cylinder that can be controlled by any standard.

[0006]

Not only is the problem underlying the present invention relatively low in constructional cost and does not require major modifications to conventional suspensions,
Furthermore, it provides another important possibility to influence and improve the self-steering condition, ie the driving characteristics of the vehicle.
Is to provide a rear axle of a vehicle of the kind described in the generic concept of.

[0007]

According to the invention, the bearings on the vehicle body side are spaced apart from one another and are fixed together on a bearing support rotatably supported on the vehicle body, the axis of rotation of the bearing support body being fixed. Is in at least a substantially vertical vertical plane of the vehicle and is adjustable in this vertical plane by an actuator between at least a substantially vertical direction and at least a substantially horizontal direction, the two bearings each rotating a bearing support. The solution is to be provided at approximately the same distance from the axis. An advantageous embodiment of the invention is described in claim 2.

In the case of the rear axle of a motor vehicle according to the invention,
A bearing support that slides the body-side end of the guide arm fixed to the stub shaft relative to the vehicle body to cause the rear wheel operation turning is provided so that the body-side end of the guide arm moves in the horizontal direction. Not only is it formed so that it can slide in the vertical direction relative to the vehicle body.

Depending on the business situation, the camber of the rear wheels or the steering angle can be easily influenced, if desired, and a mixture of both can occur.

It is advantageous to adjust the opposing camber, for example, which only affects the camber of the wheels when driving on a curve and improves, for example, the stability of the curve. On straight roads and at high speeds, in order to stabilize the straightness of the vehicle, it is advantageous to make only the rear wheel steering turn and also in the reverse steering direction (steering turn in the same direction as the front wheel steering turn). is there. In many cases, when traveling on a curve, the rear wheels are placed in the opposite direction or the same direction as the front wheels depending on whether the self-steering state of the vehicle is affected by oversteer or understeer. It is advantageous to produce some on-coming camber and some steering turning.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the principle and schematic drawings.

A rear wheel 1 of an automobile rear axle according to the present invention, which is exemplarily shown in the drawings, is pivotally attached to a vehicle body 3 (not shown in detail) via tilting arms 2 and 2a. In this case, in order to simultaneously show different examples, differently formed triangular tilt arms 2, 2a are shown in the left and right parts of the principle drawing, respectively.

The two wheels 1 are pivotally mounted, in particular, via stub shaft fixed guide arms 21 which determine the direction of rotation. The guide arm is fixed to the stub shaft of the wheel 1 or the wheel support 11 at a constant angle. The guide arms are each part of a tilted arm structure 2 or 2a pivotally mounted on the vehicle body 3 in two spaced apart arm bearings 4 and 5, respectively. In the case of the structure shown in the right part of the figure, this guide arm is an integral part of the rigid integral triangular tilt arm 2a shown therein. On the other hand, in the case of the tilted arm structure 2 shown on the left side of the drawing, the guide arm is formed by a separate support member having rigidity extending obliquely. The support member forms a tilting arm with spring struts 22 which are oriented in the longitudinal direction of the vehicle and can bend around its vertical axis. The wheel 1 can be pivotally mounted via a vertical arm structure as shown, instead of a tilted arm structure. In the case of this vertical arm structure, the arm bearings 4, 5 are mounted on the same transverse line.

While the arm bearings 4 on the outside of each of the tilted arm structures 2 and 2a are formed by being fixed to the vehicle body, respectively, the arm bearings on the inside, that is, the guide arm 21 (or the right side) fixed to the stub shaft are formed. The bearing 5 on the vehicle body side (corresponding part of the integral tilt arm 2a) of the vehicle body is not fixed to the vehicle body, but is mounted on a special bearing support rotatably supported on the vehicle body 3, that is, a kind of rotating disc 6. It is fixed. Thereby, the arm bearings are actuated by a common actuator acting on the bearing support 6, i.e. in the illustrated embodiment a hydraulic operating cylinder 7, depending on any vehicle or operating parameter, for example the turning angle of the front wheels and / or the axial load. It is slidable relative to the vehicle body depending on the traveling speed, the acceleration or the deceleration of the braking, the lateral acceleration or the load change.

The two bearings 5 on the vehicle body side of the guide arm 21 fixed to the stub shaft are fixed to the bearing support 6 at intervals from each other and at substantially equal intervals from the rotation axis 8 of the bearing support. Both bearings are in particular formed by means of rubber-elastic elements, so that the guide arm pivotally mounted on it can perform a spherical movement.

The axis of rotation of the bearing support 6 lies in at least a substantially vertical longitudinal plane of the vehicle. The rotation shaft is connected to the vehicle body in the following manner by a method not shown. That is, the actuator whose rotation axis is not shown
Adjustable as required, ie depending on certain desired driving parameters of the vehicle, between the at least substantially vertical direction shown in FIGS. 1 and 2 and the at least substantially horizontal direction shown in FIG. As is, and of course, controllable to any intermediate position between both extreme positions.

As shown in FIGS. 1 and 2, when the rotary shaft 8 is oriented in the vertical direction, the bearing support 6 is rotated around the rotary shaft 8 and the inner arm bearing, that is, both guide arms 21. The bearing 5 swings relative to the vehicle body 3 in the horizontal plane. In the rest position shown in FIG. 1, the inner two arm bearings 5 are located on the same virtual imaginary axis extending laterally with respect to the vehicle longitudinal direction. Starting from this rest position, the arm bearings move relative to the vehicle body in the longitudinal direction of the vehicle in opposition to one another, i.e. further forward or further rearward, as can be seen in FIG. 2, when the bearing support rotates. This sliding of the inner arm bearing will result in a steering turn of the rear wheel 1. At that time, the rear wheels swing around the rotation point D, which is schematically shown in FIG. 2, like the kingpin steering.

In the case of the tilting arm structure shown in the left part of the figure, this rocking of the rear wheel is correspondingly effected by a longitudinal support member 22 of the tilting arm which is formed so that it can bend around the vertical axis. It is possible by deforming. On the contrary,
In the case of the tilt arm structure shown on the right side of the figure, the steering swing of the right rear wheel 1 or the rocking motion of the triangular integral tilt arm 2a for that purpose is performed by the arm bearings 4 on the outside of this tilt arm. This is possible by including a rubber-elastic element that is appropriately dimensioned, that is to say relatively soft in the lateral direction of the vehicle, which element allows the necessary rocking movement of the tilting arm.

In order to have a desired influence on the self-steering state, that is, the running characteristics of the vehicle, a relatively small steering turning angle of the rear wheel 1 is generally required. In general, a maximum steering angle α of the order of plus or minus 3 ° is sufficient, so that the required deformation of the longitudinally oriented spring struts 22 or the required elasticity of the arm bearing 4 on the outside of the right-hand tilting arm 2a. Limited.

When the axis of rotation 8 of the bearing support 6 swings backwards from FIG. 1 about the pivot point 5 in the preselected vertical longitudinal plane of the vehicle, the rotation of the bearing support about the axis of rotation 8 At the same time, or exclusively as shown in FIG. 3, it affects the camber of the rear wheels. Therefore, the opposite camber can be easily adjusted when traveling on a curve. As shown in FIG.
If the rotation axis 8 of the bearing support is oriented substantially horizontally, for example, the rotation of the bearing support about the rotation axis 8 causes the inner arm bearings, that is, the bearing 5 on the vehicle body side of the guide arm 21 to move in the opposite direction. On the one hand, it goes up strongly and, on the other hand, it goes down strongly, ie it moves further towards the roadway. This raising and lowering of the inner arm bearing will correspondingly change the inclination of the wheel 1 by the angle β, which will change the camber of the wheel.

Any desired combination of the steering turning angle α and the camber β of the rear wheel 1 can be easily adjusted by changing the direction of the rotation axis 8 in order to affect the self-steering state and the running characteristics of the vehicle. Is.

The rear wheels of the motor vehicle according to the invention may be formed as an undriven or driven shaft. In FIGS. 1 and 2, the driven rear wheel differential is designated by the reference numeral 9 and is indicated by a dashed line. In this case, instead of bearing the bearing support 6 rotatable around the rotary shaft 8 on the lower surface of the vehicle body, the bearing support 6 or the rear axle differential device 9 can be supported. In this case, the cardan shaft can extend below or above the bearing support 6.

[0023]

As described above, in the rear axle of the automobile according to the present invention, the bearing for sliding the end of the guide arm fixed to the stub shaft on the vehicle body side relative to the vehicle body in order to cause the rear wheel to be turned. Since the support body is formed so that the end portion of the guide arm on the vehicle body side can slide relative to the vehicle body not only in the horizontal direction but also in the vertical direction as required, It is possible to affect only the steering angle, only the steering angle, or both. Therefore, the self-steering state, that is, the traveling characteristic of the vehicle is improved.

[Brief description of drawings]

1 is a plan view of the rear axle of a motor vehicle according to the invention with the guide arm in the neutral or rest position, FIG.

FIG. 2 is a plan view of a rear axle on which the rear wheels turn to steer.

FIG. 3 is a diagram showing a rear axle in a traveling direction in which a rear wheel camber is adjusted.

[Explanation of symbols]

 1 Wheel 3 Car Body 5 Bearing 6 Bearing Support 7 Actuator 8 Rotation Axis 21 Guide Arm

Claims (2)

[Claims] 1. A rear wheel (1) is pivotably attached to a vehicle body (3) via a guide arm (21) fixed to a stub shaft, which determines the rotation direction of the rear wheel (1).
In the rear axle of the vehicle, the bearing (5) on the vehicle body side of 1) is slidable relative to the vehicle body (3) by one common actuator (7), for example, depending on the steering turning angle of the front wheels. The bearings (5) on the vehicle body side are fixed together with a bearing support (6) rotatably supported on the vehicle body (3) with a space therebetween, and a rotation axis (8) of the bearing support
Is in at least a substantially vertical vertical plane of the vehicle and is adjustable in this vertical plane by an actuator (7) between at least a substantially vertical direction and at least a substantially horizontal direction, and both bearings (5) are respectively A rear axle of a motor vehicle, wherein the rear axle is provided at substantially the same distance from the axis of rotation (8) of the bearing support (6). 2. A stub shaft fixed guide arm (21) is provided with two arm bearings (4, 4) spaced apart from each other.
5) is a part of a tilted arm or a vertical arm structure (2, 2 ') pivotally attached to the vehicle body (3) in a swingable manner, and the outer arm bearings (4) are fixed to the vehicle body, respectively. Rear axle of a motor vehicle according to claim 1, characterized in that the inner arm bearings are formed by bearings (5) fixed to respective rotatable bearing supports (6).