DE19942890A1 - Adjusting device for wheel angle and wheel suspension for motor vehicles is located between MacPherson strut unit and vehicle body part for moveable bearing of strut unit connection point on body part - Google Patents

Abstract

The device (1) is part of a wheel suspension with MacPherson strut (5), and the wheel angle is dependent upon the rake angle of the strut unit. It is formed to be positioned between the strut unit and a body part (4), and for moveable bearing of the body-sided connection point (A) of the strut unit on the body part. The device is moved during travel to vary the effective length (l) and rake angle of the strut unit. The movement incorporates a directional component (y) in vertical vehicle direction, or a component (x) at right angles to a longitudinal vehicle direction, and a component (y) in vertical vehicle direction.

Description

The invention relates to an adjusting device for the camber angle of a vehicle wheel in a suspension having a shock absorber, the camber angle of the Spread angle of the shock absorber is dependent. The invention further relates to a Wheel suspension with such an adjustment device.

The wheels of a motor vehicle are connected to the vehicle body via a wheel suspension connected, which leads the wheels. The driving behavior depends among other things on the Adjustment of the wheel suspension. The camber angle γ is important.

The camber angle γ is understood to mean the inclination of the plane of rotation of a wheel to the vertical, an inclination towards the vehicle being regarded as a negative angle and away from the vehicle as a positive angle, as is shown in FIG. 2. In principle, a camber angle of 0 ° is aimed for when driving straight ahead, since then the vehicle wheels just stand on the ground and the deformation work on the tires remains low. In practice, the vehicle is usually driven with small negative camber angles. For reasons of clarity, the invention is described below on the basis of a normal position when driving straight ahead with a camber angle of 0 °, where angular deviations are to be understood as related to this normal position, which, as already mentioned, in practice from a 0 ° angle both in can deviate more positively and also in the negative direction.

Fig. 2 shows as a further, driving behavior variable influencing the spread angle σ, ie, the tendency of a shock absorber of the wheel suspension to the vertical.

When driving through a curve, depending on the kinematics of the wheel suspension, there is an increased inclination of the wheels, as can be seen from the solid lines in FIGS . 3a-c, each of which is a left front wheel of a vehicle with a Mc-Pherson wheel suspension demonstrate. In this Figure corresponds. 3c the state at a turning-wise outside wheel when driving through a curve to the right. Due to the effect of centrifugal force, this results in a torque about the roll axis running in the longitudinal direction of the vehicle, which leads to a deflection of the suspension strut of the wheel on the outside of the curve and an outward tilting. This tilting movement is also referred to as rolling, while a rotation about a vehicle transverse axis is referred to as pitching.

With the deflection, in addition to the inclination of the bodywork, a change in the wheel inclination towards the curve is associated, ie a negative, larger amount camber angle γ occurs on the outer wheel, so that the wheel-ground contact is no longer optimal. At the same time, the spreading angle σ increases compared to the normal position shown in FIG. 3a, ie the inclination of the suspension strut increases.

The state of the wheel on the inside of the curve is shown in FIG. 3b by driving through a left curve. The torque around the roll axis leads to a rebound of the strut and a steeper positioning of the strut, which is synonymous with a reduction in the spreading angle σ. As a result of the kinematics of the suspension of the wheel axle, the wheel then moves in the direction of a positive camber angle γ, which on the wheel on the inside of the curve means an inclination into the curve.

Fig. 4a, the impact of the deflection and rebound of the wheels of an axle is on the vehicle body with a relatively strong rolling movement. In addition, the camber angle setting is not optimal.

There are therefore various measures to change the wheel inclination Curving has been proposed, but this leads to a change in the natural frequency of the vehicle body and the damping dimension.

From EP-B1-0 352 178 is an adjustment device for changing the fall during known from driving, in which a wheel hub carrier over a substantially horizontal arranged eccentric disc is mounted on a wishbone. The eccentric is connected via a linkage to the steering of the vehicle, so that its position from Steering angle depends. A change occurs by turning the eccentric disc the inclination of the wheel hub carrier and thus the camber angle in the direction of an erection the plane of rotation of the wheel. With the twist in the horizontal not only one occurs Change in the camber, but also a change in the caster of the wheel. It is also known from EP-B1-0 352 178, the compression of the struts with the To couple eccentrics with a linkage. This is an active roll or pitch compensation however not possible.

The invention is based on the object, in particular in relation to the driving behavior in the curve improved adjustment device for the camber angle To create vehicle wheel.

This object is achieved by an adjusting device of the type mentioned at the beginning, wherein the adjustment device for arrangement between a vehicle body section and the strut and for the movable mounting of the body-side articulation point of the Strut is formed on the vehicle body section, the Adjustment device for changing the effective length of the shock absorber and Spreading angle is movable during driving, and wherein the movement is a Direction component in the vertical direction of the vehicle or a direction component transverse to a vehicle longitudinal axis and a direction component in the vehicle vertical direction includes.

This arrangement in the upper suspension strut bearing enables a targeted adjustment of the Spreading angle and thus the camber of the wheel in question with simultaneous roll and / or pitch compensation. By changing the effective length of the strut, i.e. H. the distance of the body support point from the wheel hub axis can the body better kept horizontal by swaying and nodding below certain driving conditions, e.g. B. is reduced when cornering.

This can be done by moving the adjustment device vertically Articulation point alone, because this already changes not only the effective length of the struts in the sense of compensation of the deflection or rebound, but also a correction of the spread with respect to the normal position.

A greater scope for adjustment, for example through a stronger correction or The spread angle can be enlarged compared to the normal position by the additional directional component of the movement transverse to the vehicle's longitudinal axis realize.

In both cases there is no change in the wake. The frequency behavior as well the level of damping is not increased or decreased by the body influenced and remain constant during the adjustment.  

The two directional components are preferably positively coupled to one another. As a result, both the camber and a correction can be corrected by a single adjustment also the horizontal position of the vehicle body. This solution is special simple and therefore inexpensive to manufacture.

In an advantageous embodiment, the articulation point is guided along a movement path, which can be designed as an axis in a particularly simple embodiment. The Movement path or axis is arranged so that when the strut rebounds a movement of the pivot point in the direction of a lowering in the vertical below Shortening the effective length of the shock absorber and increasing the Spreading angle takes place.

It is also preferable to improve the driving behavior on the outside wheel the articulation point is guided along a movement path which is arranged such that at a compression of the strut a movement of the pivot point in the direction of Elevation in the vertical while increasing the effective length of the shock absorber and the The spreading angle is increased. This measure is preferably carried out with the connected above.

According to a further embodiment, there is a movement when the shock absorber rebounds towards a lowering in the vertical with a movement across Longitudinal vehicle axis coupled to the vehicle. This shortens the effective length of the shock absorber and an increase in the spread angle. So that can Behavior on the inside wheel can be improved.

According to a further embodiment, there is a movement when the shock absorber is deflected towards an elevation in the vertical with a movement across Longitudinal vehicle axis coupled to the vehicle, to increase the effective length of the Shock absorber and increasing the spreading angle. So that the behavior on the outside wheel to be improved.

The adjusting device preferably has an integral adjusting element Coupling of motion on, as a unit at the location of the upper pivot point of the shock absorber to be ordered. Modifications in the vicinity of the wheel are not necessary for this.

According to a further embodiment, the integral setting element is not susceptible to faults mechanically trained.  

Preferably, the integral adjustment element is a rotatable one on which Vehicle body section attachable eccentric formed on which the The pivot point of the spring strut is provided eccentrically to the axis of rotation thereof. However are here also other mechanical constructions, for example in the form of a slide guide possible.

In an alternative embodiment, the integral setting element is hydraulic and / or pneumatically and / or electrically trained.

According to a further advantageous embodiment, the adjustment device has Actuator on that with the integral adjustment element for adjusting the same is coupled, the actuator depending on the vehicle steering and / or driving state parameters causes an adjustment. This can be another Refinement of the adjustment of the camber setting and the roll or pitch behavior achieve, for example, taking into account the vehicle speed, so to enable intelligent wheel suspension.

In a simple embodiment, the actuator is mechanical with one Steering angle of the vehicle representative element of the vehicle steering coupled.

To optimize the adaptation to different driving conditions that are not based on the The cornering device preferably has a device for recording driving condition parameters including a steering angle and a these parameters processing device for determining a camber angle in Dependency of the detected parameters on which the actuator the one determined Camber angle provides appropriate information. This information, for example a Electrical, hydraulic or pneumatic signal can be with the Actuator transferred to the integral adjuster that while driving an adjustment of the upper pivot point of the shock absorber in the desired manner makes.

In principle, a decoupling of the movement components of the upper one Articulation point possible, which results in a more complex construction, but the as far as possible to adapt the suspension to individual Includes driving conditions.  

In an advantageous embodiment, the steering angle is used as a guide parameter Determination of the camber angle used by further driving condition parameters is modified. For example, a speed-dependent correction of the Spread, the camber angle and the horizontal orientation can be realized.

The actuating member is preferably a hydraulic and / or pneumatic one Actuator trained. An electrical actuator is also possible.

The above object is further achieved by suspension with a Vehicle body section and a strut mounted on this, and one in Articulation point of the shock absorber arranged on the vehicle body section Adjustment device which is designed in the manner described above.

The invention is illustrated below with the aid of one in the drawing Embodiment explained in more detail. The drawing shows in

Figure 1 shows a wheel suspension with an adjusting device according to the embodiment.

Fig. 2 γ a definition of a camber angle occurring at the wheel suspension, and a spread angle σ;

3a shows the effect of the adjustment on the camber angle and the altitude of the vehicle-side articulation point of the spring strut at a left front vehicle wheel in the normal position when driving straight.

FIG. 3b shows the arrangement of Figure 3a when driving through a left turn, ie on the inside of the curve wheel.

FIG. 3c shows the arrangement of Figure 3a when driving through a curve to the right, ie, at the turning-wise outside wheel.

4a shows the position of a vehicle body with a conventional wheel suspension when cornering. and

Fig. 4b, the position of a vehicle body with a wheel suspension according to the embodiment when cornering to illustrate the leveling of the vehicle body.

The exemplary embodiment in FIG. 1 shows a McPherson wheel suspension on a vehicle body section 4 with a strut 5 mounted thereon, which is designed as a parallel connection of a spring 6 and a damper 7 . The upper end of the spring strut 5 is conventionally articulated at a pivot point A to the body section 4 . According to the invention, an adjusting device 1 is provided at this point, which enables the articulation point A to be displaced in order to influence the spreading angle σ and to improve the leveling of the vehicle body. The movement in the exemplary embodiment comprises a direction component in the vehicle vertical direction y and a direction component x transversely to a vehicle longitudinal axis.

A wheel carrier with a wheel hub 10 is provided on the spring strut 5 in the area near the wheel, about whose axis N a wheel 9 is rotatably mounted. The kinematics are designed in such a way that a change in the spreading angle causes a change in the camber angle. An increase in the spread angle σ is always associated with a change in the wheel position in the direction of a negative camber γ.

The change in the spreading angle σ takes place by means of an integral adjusting element which is mounted on the vehicle body section 4 and which is designed here as a mechanical component and in particular as an eccentric disk 2 . This eccentric disc 2 is coupled via a hinge pin 3 to an eye 8 at the upper end of the spring strut 5 or the damper 7 . The bearing of the bolt 3 always represents the effective articulation point A of the strut 5 on the vehicle body.

As can also be seen in FIG. 1, the axis of rotation of the eccentric element in the installed state runs essentially horizontally in a wheel suspension, so that the element 2 designed as a disc is arranged essentially upright here. In addition, the axis of rotation is arranged parallel to the longitudinal axis of the vehicle. Rotation of the eccentric element leads to a displacement of the articulation point A in the vertical y and in a direction x transversely to the vehicle without a noticeable shift in the direction of a parallel of the longitudinal axis of the vehicle.

From Fig. 1 there is further characterized in that at the same time a displacement in the vertical y occurs with a shift of the location of the bolt 3 in the x-direction, since both movements are compulsively coupled together. The displacement results in a change in the spread σ of the strut 5 and thus an adjustment of the camber angle γ on the wheel 9 . With the adjustment in the y direction, depending on the movement of the articulation point A, the vehicle body is raised or lowered on the wheel.

It is apparent to the person skilled in the art that an adjustment of the articulation point A in the vertical y with a change in the spreading and therefore the camber angle connected is. By means of a movement component also across the vehicle however achieve larger angle corrections.

The invention is not limited to the use of the eccentric disk shown or a mechanical adjusting element. Rather, this can also be designed pneumatically, hydraulically or electrically, but there is always an adjustment of the camber angle γ and an adjustment of the height of the articulation point A in the vertical. The adjusting element always remains directly integrated between the upper end of the spring strut 5 and the associated vehicle body section 4 .

The operation of the exemplary embodiment will now be described with reference to FIGS . 3a to 3c, FIG. 3a showing a normal position of the wheel suspension when driving straight ahead in the unsprung state, while FIG. 3b shows driving in a left-hand curve and FIG. 3c shows driving in a right-hand curve . Here, only the wheel suspension of a left front wheel 9 is shown, which rolls on a roadway level F.

To simplify the explanation, a camber angle γ ₀ of 0 ° is assumed in FIG. 3a. The kinematics of the wheel suspension then require a spread angle σ ₀ . In its starting position A _{0, the} upper articulation point is approximately in the 9 o'clock position. The spring-damper arrangement 6/7 occupies a central position so that an effective output strut length l ₀ as the distance between the pivot point A ₀ and N of the hub axle sets. Furthermore, the instantaneous pole MP is shown, around which the wheel 9 rotates on the indicated arc line when deflected.

When driving in a left turn, the inside wheel 9 rebounds, as shown in Fig. 3b, ie the effective length of the strut is increased compared to the initial length l ₀ , so that the height of the pivot point A _{1 is} greater. This leads to the vehicle tilting or swaying outward about the roll axis in the vehicle longitudinal direction in the vehicle center plane M. At the same time, the wheel 9 tilts into the curve, with a steeper and thus smaller spreading angle σ _{1 being} established. The wheel camber angle γ changes in the direction of a positive angle.

In order to reduce the inclination of the curve of the wheel 9 on the inside of the curve, the articulation point A _{1 is} shifted with the adjusting device 1 to A ₁ *, ie moved from the 9 o'clock position towards a 6 o'clock position or towards the vehicle and down. The strut 5 then assumes the position shown in dashed lines, in which the spread angle σ ₁ * is greater than σ ₁ , so that the wheel 9 is more upright. At the same time, the effective length of the spring strut 5 is shortened, as a result of which a leveling effect is achieved and thus swaying or nodding is compensated.

When driving through a right-hand curve, the wheel suspension shown in FIG. 3c of the wheel 9 on the outside of the curve then springs in. The deflection of the associated shock absorber 5 leads to an inclined position of the latter, so that a larger spreading angle σ ₂ and, due to the suspension kinematics, a negative camber angle γ ₂ with an inclination of the outside wheel 9 into the curve is established compared to the normal position. The associated lowering of the articulation point A ₂ leads to an inclination of the vehicle body as shown in FIG. 4a. To compensate for the inclination, the associated adjusting device 1 is actuated in the direction of an increase in the vertical y and an inward movement x, so that the improved position indicated by the dashed lines is achieved with the articulation point A ₂ *, in which an optimization the position of the wheel 9 in the curve and again a leveling of the vehicle body. The latter can be seen particularly well from FIG. 4b which, like FIG. 4a, shows a vehicle in a right-hand curve, but in contrast to FIG. 4a with adjustment devices 1 provided in the wheel suspensions. The correction movement of the articulation point for the outside wheel 9 corresponds to a rotation of the eccentric disc from the 9 o'clock position towards a 12 o'clock position.

The correction effects of FIGS . 3b and 3c could indeed be provided by an appropriate design of the adjusting element alone. However, it is recommended to use both correction effects together to optimize the leveling.

The adjustment of the integral setting element can be done in any way by a mechanical, electrical, pneumatic or hydraulic actuator. An example of this would be a linkage coupled to an element of the steering, the one specifies steering angle-dependent control signal. For the purpose of chassis optimization In addition to the steering angle as a reference variable, other driving condition parameters such as for example, include a vehicle speed, for which purpose corresponding Detection devices such. B. sensors are provided. The determined by these Signals then enable the camber angle to be specified depending on the driving state and thus an optimally adjusted coordination of the wheel suspension. In addition, everyone can Wheel suspensions of a vehicle can be coordinated with each other in order to achieve an optimal Nick and roll compensation.  

REFERENCE SIGN LIST

1

Adjustment device

2nd

Eccentric element

3rd

Hinge pin

4th

Vehicle body section

5

Shock absorber

6

damper

7

feather

8th

eye

9

wheel

10th

wheel hub
γ camber angle
σ spread angle
A pivot point
N hub axle
M middle plane
MP current pole

Claims (17)

1. Adjusting device for the camber angle of a vehicle wheel in a suspension having a suspension strut ( 5 ), the camber angle (γ) being dependent on the spreading angle (σ) of the suspension strut, characterized in that the adjustment device ( 1 ) is arranged between a vehicle body section ( 4 ) and the suspension strut ( 5 ) and for the movable mounting of the articulation point (A) of the suspension strut ( 5 ) on the vehicle body section ( 4 ), the adjusting device ( 1 ) for changing the effective length (l) of the suspension strut ( 5 ) and the spreading angle (σ) is movable during driving, the movement comprising a directional component (y) in the vehicle vertical direction or a directional component (x) transverse to a vehicle longitudinal axis and a directional component (y) in the vehicle vertical direction. 2. Device according to claim 1, characterized in that the articulation point (A) is guided along a movement path which is arranged such that when the spring strut ( 5 ) rebounds, a movement of the articulation point in the direction of a lowering in the vertical while shortening the effective length of the shock absorber ( 5 ) and increasing the spread angle (σ). 3. Apparatus according to claim 1 or 2, characterized in that the articulation point (A) is guided along a movement path which is arranged such that when the spring strut ( 5 ) deflects, a movement of the articulation point in the direction of an increase in the vertical under The effective length of the shock absorber ( 5 ) and the spreading angle (σ) are increased. 4. Device according to one of claims 1 to 3, characterized in that the two directional components (x, y) are forcibly coupled with each other. 5. Device according to one of claims 1 to 4, characterized in that the wheel suspension kinematics is designed such that when the spring strut ( 5 ) rebounds, a movement in the direction of a lowering in the vertical is coupled with a movement transverse to the longitudinal axis of the vehicle , to shorten the effective length (l ₀ ) of the shock absorber ( 5 ) and to increase the spreading angle (σ). 6. Device according to one of claims 1 to 5, characterized in that the wheel suspension kinematics is designed such that when the spring strut ( 5 ) is deflected, a movement in the direction of an increase in the vertical is coupled with a movement transversely to the longitudinal axis of the vehicle , to increase the effective length (l ₀ ) of the shock absorber ( 5 ) and to increase the spreading angle (σ). 7. Device according to one of claims 1 to 6, characterized in that the Adjusting device has an integral adjusting element for coupling motion. 8. The device according to claim 7, characterized in that the integral Adjusting element is designed mechanically. 9. Apparatus according to claim 7 or 8, characterized in that the integral adjusting element is designed as a rotatable eccentric element ( 2 ) which can be attached to the vehicle body section and on which the articulation point (A) of the strut is provided eccentrically to the eccentric element axis of rotation. 10. The device according to claim 7, characterized in that the integral Adjusting element is designed hydraulically and / or pneumatically. 11. The device according to one of claims 7 to 10, characterized in that the Adjusting device has an actuator that with the integral Adjustment element for adjusting the same is coupled, the actuator in Depending on the vehicle steering and / or driving condition parameters Adjustment causes. 12. The device according to one of claims 7 to 11, characterized in that the Actuator mechanically with a steering angle of the vehicle representative element of the vehicle steering is coupled. 13. The device according to one of claims 7 to 12, characterized in that the Adjustment device a device for recording driving state parameters including a steering angle and a device processing these parameters for determining a camber angle depending on the detected parameters,  that the actuator corresponding to the specific camber angle Feeds information. 14. Device according to one of claims 11 to 13, characterized in that the Actuator is designed as a hydraulic and / or pneumatic actuator. 15. The device according to one of claims 11 to 13, characterized in that the Actuator is designed as an electrical actuator. 16. The device according to one of claims 11 to 15, characterized in that the Steering angle is the guide parameter for determining the camber angle, which is determined by the Driving state parameter is modified. 17. Wheel suspension for a vehicle, comprising a vehicle body section ( 4 ) and a suspension strut ( 5 ) mounted thereon, and an adjusting device ( 1 ) arranged in the articulation point of the suspension strut on the vehicle body section for the camber angle of a vehicle wheel according to one of claims 1 to 16.