wishbone

Abstract

A wishbone for a wheel suspension comprising a front body-side pivot bearing (2) and a rear body-side pivot bearing (3) and a wheel-side connection point, wherein the pivot bearings (2, 3) define a body-side pivot axis (23), and wherein a front wheel-side pivot bearing (10) and a rear wheel-side pivot bearing (11) are provided at the wheel-side connection point, wherein the front and the rear wheel-side pivot bearings (10, 11) define a wheel-side pivot axis (24), wherein the body-side pivot axis (23) runs parallel to the wheel-side pivot axis (24), characterized in that a front pivot bearing axis (5) of the front body-side pivot bearing (2) and a rear pivot bearing axis (6) of the rear body-side pivot bearing (3) are inclined relative to the body-side pivot axis (23).wherein the front pivot bearing axis (5) is inclined relative to the body-side pivot axis (23) by a first angle (30) with respect to a front vertical axis (25) passing through the center of the front body-side pivot bearing (2) and perpendicular to a principal extension plane defined by the body-side pivot axis (23) and the wheel-side attachment point, and the rear pivot bearing axis (6) is inclined relative to the body-side pivot axis (23) by a second angle (31) with respect to a rear vertical axis (26) passing through the center of the rear body-side pivot bearing (3), wherein the first angle (30) and the second angle (31) have the same magnitude,and wherein the front pivot bearing axis (5) is inclined relative to the body-side pivot axis (23) by a third angle with respect to a front transverse axis (27) extending in the main extension plane and perpendicular to the body-side pivot axis (23) through the center of the front body-side pivot bearing (2), and the rear pivot bearing axis (6) is inclined relative to the body-side pivot axis (23) by a fourth angle with respect to a rear transverse axis (28) extending through the center of the rear body-side pivot bearing, and wherein the third angle and the fourth angle have the same magnitude.

Description

[0001] The present invention relates to a control arm for a wheel suspension according to the preamble of claim 1 and to the use of this control arm in an independent wheel suspension for the unsteered wheels of a motor vehicle, in particular a rear wheel suspension.

[0002] The three essential parameters for determining the position of a motor vehicle wheel are camber and toe. The present invention relates in particular to the control of the toe angle (toe-in control) in the case where a force acting on a wheel is directed essentially backwards in the longitudinal direction of the motor vehicle (backward force), as is generally the case, for example, during a deceleration process of a motor vehicle and in particular during a braking process.

[0003] During deceleration, a resulting backward force acts on the wheel and is transmitted via a wheel carrier connected to the wheel to a wheel-side mounting point of the control arm. This causes the control arm to move rearward relative to the vehicle body, to which it is connected via rubber-elastic bearings, particularly swivel bearings. During this movement, the rubber-elastic bearings, especially the rubber-elastic bushings, are elastically deformed.

[0004] The elastic deformation has both a longitudinal component in the bearing bushings and a radial component in the direction of the bearing bushings. In particular, the backward force acting at the wheel-side mounting point exerts a torque on the body-side bearings, causing the front body-side bearing (viewed in the longitudinal direction of the vehicle) to be loaded radially outwards, i.e., from the front body-side bearing towards the wheel-side mounting point, and the rear body-side bearing (viewed in the longitudinal direction of the vehicle) to be loaded radially inwards, i.e., from the wheel-side mounting point towards the rear body-side bearing.The elastic deformation of the bearing bushings in the radial direction essentially results in the control arm and consequently the wheel connected to it experiencing, in addition to a linear backward movement, a rotational movement when a backward force is applied, which leads to a change in the toe angle of the wheel, reducing the toe-in or increasing the toe-out.

[0005] Control arms of this type are the subject of numerous publications. For example, EP 0 220 851 B1 discloses a control arm which, by means of a toe correction element attached to a pivot bearing on the vehicle body, controls the toe angle of the wheel articulated at the wheel-side mounting point as a function of a force acting on the wheel in the longitudinal direction of the vehicle. The toe correction element is pivotably connected at one end to the control arm itself and at the other end to a pivot pin of the pivot bearing on the vehicle body.

[0006] DE 10 2005 030 810 A1 relates to an independent wheel suspension for the rear wheels of motor vehicles, comprising a wheel carrier articulated to at least one upper and one lower control arm, wherein the lower control arm is articulated to the vehicle body and the wheel carrier via two control arm bearings forming essentially horizontal pivot axes, and a control arm of the wheel carrier is connected to a further control arm, further comprising a leaf spring supported on the vehicle body and the wheel carrier, and a substantially vertically oriented telescopic shock absorber. Viewed from above, the further control arm is essentially arranged in the lower control arm plane and inclined obliquely from the outside inwards to the front such that the intersection of imaginary extensions of the further control arm and the rear pivot points of the lower control arm lies behind the extended wheel center axis.

[0007] An arm for an independent motor vehicle suspension, for connecting the wheel carrier of a vehicle wheel to the vehicle body, is disclosed in WO 2007 / 113 761 A2. The arm comprises a pair of crossbars connected at their outer ends to the wheel carrier of a vehicle wheel and at their inner ends to the vehicle body, and at least one pair of connecting elements connecting the bars to each other, preferably designed as leaf- or plate-like elements such that their bending stiffness in one plane is higher than their bending stiffness in a direction perpendicular to that plane. The arm is capable of controlling two translational degrees of freedom along the axes of the bars.

[0008] A trailing arm suspension comprising a suspension arm suspended from a suspension element via elastically deformable elements is described in EP 0 070 025 A2. The elastic elements are arranged such that the longitudinal axis of at least one of the elements is inclined with respect to a pivot axis of the suspension arm to allow vertical displacement about this axis. The inclination angle of the element is chosen such that an axis of high stiffness of the elastic element, normal to its longitudinal axis, intersects the axis of high stiffness of the other elastic element at a point behind the pivot axis. The point of intersection of the axes of high stiffness lies behind the pivot axis of the suspension arm and behind and outside the traction point of a road wheel.

[0009] A vehicle suspension mechanism according to US 4,564,213 A comprises a support for a rear wheel rotatably mounted about a pivot axis, a strut assembly whose upper end is connected to a vehicle body and whose lower end is connected to the support, and a pivoting arm pivotally connected to the vehicle body at longitudinally spaced first front and first rear points and to the support at longitudinally spaced second front and second rear points via elastic rubber bushings. These points are arranged such that the distance between the line connecting the first front and first rear points and the line connecting the second front and second rear points increases toward the rear, thereby producing toe-in motion when the arm pivots upward.

[0010] According to JP S59-8511A, one end of the wishbones is mounted to a side bracket of the vehicle body via a bearing. A wheel hub is mounted to the other end of the wishbones via a bearing support consisting of a bushing made of elastic material. A rearward-extending arm is integrally formed with the hub, and a pointed end of the arm is connected to one end of a stabilizer bar via a control rod. Furthermore, the rear end of a forward-extending trailing arm is connected to the hub. When the rod is tilted laterally along the body, with its upper end facing inward and its lower end facing outward, the stabilizing reaction force acts as a vertical component, pushing the arm downward, and a horizontal component, pushing the arm outward. This allows the position of the hub to be changed in the toe-in direction.

[0011] DE 27 29 962 A1 relates to an independent wheel suspension for non-steerable wheels of motor vehicles, in particular passenger cars, with wheel guide elements pivotably mounted on the vehicle body via elastic bearings, wherein the bearing axes are inclined to the pivot axis of the wheel guide elements. The bearing axes are oriented relative to each other such that, when the wheel guide element is moved laterally in the direction of the vehicle, it pivots about the vehicle's vertical and / or longitudinal axis in such a way that the toe-in and / or the roll center is affected.

[0012] An independent strut suspension system for a non-steerable wheel of a road vehicle, according to US 4,046,403 A, consists of a unitary control arm with two body pivot points spaced apart longitudinally along the vehicle and two axle housing pivot points spaced apart longitudinally along the vehicle, an axle housing mounted on the control arm such that it rotates only about an axis between the axle housing pivot points, an axis on the axle housing perpendicular to the longitudinal direction of the vehicle, wherein the body pivot point and the axle housing pivot point are located furthest from the center of the vehicle body along the longitudinal direction of the vehicle, as measured by a horizontal projection on a line parallel to the axis, wherein the body pivot points, when viewed on the horizontal projection, lie on a line at an angle to the axle housing.wherein the body pivot point of this line is parallel to the axis and closer to the vehicle center than the other body pivot point, wherein the axis between the axle housing pivot points, viewed on a horizontal projection, is parallel to the line on which the line between the body pivot points lies, and a support device, one end of which is connected to the axis.

[0013] German patent DE 616 002 A discloses rubber-metal bushings. German patent DE 1 655 653 A also deals primarily with rubber elements.

[0014] The present invention is based on the objective of providing an improved embodiment for a control arm of the generic type, which is in particular structurally simple and suitable for controlling the toe angle of a wheel connectable to the control arm as a function of a longitudinal force acting on this wheel or via this wheel at a wheel-side connection point of the control arm, in particular a backward force.

[0015] This problem is solved according to the invention by a transverse control arm with the features specified in claim 1.

[0016] A wishbone for a wheel suspension is shown, comprising a front body-side pivot bearing and a rear body-side pivot bearing and a wheel-side connection point, wherein the pivot bearings define a body-side pivot axis, and wherein a front wheel-side pivot bearing and a rear wheel-side pivot bearing are provided at the wheel-side connection point, wherein the front and the rear wheel-side pivot bearings define a wheel-side pivot axis, the body-side pivot axis being parallel to the wheel-side pivot axis. According to the invention, a front pivot bearing axis of the front body-side pivot bearing and a rear pivot bearing axis of the rear body-side pivot bearing are inclined relative to the body-side pivot axis, wherein the front pivot bearing axis is inclined relative to the body-side pivot axis by a first angle with respect to a plane perpendicular to a principal extension plane.which is defined by the body-side pivot axis and the wheel-side attachment point, is inclined by the front vertical axis passing through the center of the front body-side pivot bearing, and the rear pivot bearing axis is inclined relative to the body-side pivot axis by a second angle with respect to a rear vertical axis passing through the center of the rear body-side pivot bearing, wherein the first angle and the second angle have the same magnitude,and wherein the front pivot bearing axis is inclined relative to the body-side pivot axis by a third angle with respect to a front transverse axis extending in the main extension plane and perpendicular to the body-side pivot axis through the center of the front body-side pivot bearing, and the rear pivot bearing axis is inclined relative to the body-side pivot axis by a fourth angle with respect to a rear transverse axis extending through the center of the rear body-side pivot bearing, and wherein the third angle and the fourth angle have the same magnitude.

[0017] Further, particularly advantageous embodiments of the invention are disclosed in the dependent claims. The description further characterizes and specifies the invention, especially in connection with the figures.

[0018] The invention is essentially based on the idea of ​​tilting a front pivot bearing axis of the front body-side pivot bearing and a rear pivot bearing axis of the rear body-side pivot bearing relative to the body-side pivot axis of the control arm defined by the pivot bearings, i.e. the front pivot bearing axis and the rear pivot bearing axis are inclined relative to the body-side pivot axis, or not aligned with it.

[0019] The body-side pivot axis is essentially defined by the connecting line that links the centers of the respective body-side pivot bearings, whereby the center of a pivot bearing is understood to be a point that lies in the middle of the pivot bearing with respect to its width and on the pivot bearing axis of the associated pivot bearing.

[0020] In a preferred embodiment, the pivot bearings on the body side have rubber-elastic bearings which have a lower stiffness, particularly in the axial direction, than in the radial direction, so that the control arm, under the influence of a backward longitudinal force acting at a wheel-side connection point during a deceleration process, in particular a braking process, pivots the wheel connectable to the wheel-side connection point in the direction of toe-in or at least significantly mitigates the toe-out of the wheel caused by the deceleration process, which will be discussed in more detail below.

[0021] For the purposes of this invention, a longitudinal force is understood to be a force that acts essentially along the longitudinal axis of the control arm or parallel to it. The longitudinal axis is essentially defined by the line connecting the centers of the body-side pivot bearings, as explained above to clarify the term "pivot axis." Accordingly, the longitudinal axis of the control arm and the body-side pivot axis run essentially parallel to each other. A longitudinal force is considered to be directed backwards if it acts in a direction from the front body-side pivot bearing towards the rear body-side pivot bearing.

[0022] The rubber-elastic bearings of the control arm according to the invention can be designed in a manner known per se, for example as rubber-metal bearings, in particular as rubber-metal bearing bushings. They can have a wide variety of configurations, provided they are softer, i.e., more compliant, in the axial direction than in the radial direction, or harder, i.e., stiffer and less compliant, in the radial direction than in the axial direction. The axial displacement of the rubber-elastic bearing due to a force acting on it only in an axial direction is thus greater than the radial displacement that the rubber-elastic bearing experiences when a force of the same magnitude acts on it only in a radial direction. It should be mentioned here that the tracking behavior of the control arm according to the invention is, of course, also determined by the elastic properties of the rubber-elastic bearings.

[0023] By deliberately tilting the front and rear pivot bearing axes of the respective body-side pivot bearings relative to the pivot axis defined by these pivot bearings, it is possible to superimpose the toe-out rotational movement, which, as described above, is caused by the torque resulting from the backward force on the pivot bearings, with a second toe-in rotational movement. The front and rear pivot bearing axes are expediently tilted relative to the pivot axis in this manner.It is assumed that the linear backward movement of the control arm along the pivot bearing axes, caused by the backward force, results in an inward movement of the front body-side pivot bearing, i.e., a movement directed essentially from the wheel-side mounting point to the front body-side pivot bearing, and / or an outward movement of the rear body-side pivot bearing, i.e., a movement directed essentially from the rear body-side pivot bearing to the wheel-side mounting point. This inward and / or outward movement of the body-side pivot bearings results, with respect to the control arm, in the aforementioned advantageous second rotational movement oriented in a toe-in direction.

[0024] Depending on the predetermined inclination angle of the front pivot bearing axis and / or the predetermined inclination angle of the rear pivot bearing axis relative to the pivot axis, as well as depending on the acting reverse force, the control arm according to the invention consequently enables targeted toe-in control of the wheel that can be connected to the wheel-side mounting point. The control arm according to the invention offers the significant advantage that additional components for correcting the wheel alignment, such as tie rods or toe correction elements connected to or supported by the control arm, or other devices provided for this purpose, can be omitted. The control arm according to the invention achieves the toe-angle correcting effect solely with the means, in particular the body-side pivot bearings, with which a control arm is always equipped. Thus, the design of the control arm according to the invention is simplified.Furthermore, the elimination of additional components reduces the installation space required for a control arm according to the invention and consequently also its weight. All the aforementioned advantages apply equally to a wheel suspension in which the control arm according to the invention can be used.

[0025] As previously mentioned, the front pivot bearing axis is inclined relative to the pivot axis by a first angle with respect to a front vertical axis perpendicular to a principal extension plane defined by the pivot axis and the wheel-side mounting point, passing through the center of the front body-side pivot bearing. The rear pivot bearing axis is inclined relative to the pivot axis by a second angle with respect to a rear vertical axis passing through the center of the rear body-side pivot bearing. Thus, the front and rear pivot bearing axes are rotated about their respective front and rear vertical axes by a first and second angle, respectively, and are therefore inclined relative to the pivot axis. The front and rear vertical axes (= axes of rotation) are defined by the principal extension plane of the control arm and the centers of the respective body-side pivot bearings.

[0026] When the front and / or rear pivot bearing axis rotates around its respective front or rear vertical axis, the pivot bearing axes essentially lie in the main plane of extension and are inclined in a transverse direction relative to the pivot axis. The transverse direction here is essentially understood to be the direction resulting from the line connecting the wheel-side mounting point and the pivot axis, with the connecting line intersecting the pivot axis at a right angle.

[0027] The first and second angles can be specified without any particular restriction, provided that both have the same magnitude. According to the invention, the first angle is understood to be the angle formed by the front pivot bearing axis and the body-side pivot axis of the control arm when the front pivot bearing axis, viewed from a top view of the control arm, is rotated counterclockwise (i.e., in the mathematically positive sense) about the front vertical axis. According to the invention, the second angle is understood to be the angle formed by the rear pivot bearing axis and the body-side pivot axis of the control arm when the rear pivot bearing axis, viewed from a top view of the control arm, is rotated clockwise (i.e., in the mathematically negative sense) about the rear vertical axis.

[0028] The rotation of the front pivot bearing axis around the front vertical axis and / or the rotation of the rear pivot bearing axis around the rear vertical axis offers the advantage of particularly efficient toe angle control. Any linear movement of the control arm along the pivot bearing axes results, due to the front and / or rear pivot axis being inclined laterally relative to the pivot axis, directly in a rotational movement of the control arm around an axis of rotation parallel to the front and rear vertical axes. This, in turn, changes the toe angle of a wheel connected via the wheel-side mounting point. The base of this axis of rotation of the control arm, that is, the point where the axis of rotation intersects the main plane of extension of the control arm and thus the center of rotation of the control arm, can be changed by means of the first and / or the second angle and can therefore be adapted to the respective design requirements.

[0029] In particular, the control arm according to the invention allows for toe-in steering if the first and / or second angles each form an acute angle, i.e., an angle greater than 0° and less than 90°. For toe-out steering, obtuse angles must be selected for the first and / or second angles, i.e., angles greater than 90° and less than 180°.

[0030] For a particularly favorable toe-in control of the control arm according to the invention, it is advantageous if the first angle is preferably selected from the range of greater than 0° to about 25°, particularly preferably about 5° to about 20° and most preferably about 10° and / or the second angle is preferably selected from the range of greater than 0° to about 25°, particularly preferably about 5° to about 20° and most preferably about 10°.

[0031] Furthermore, the first and second angles each have the same value for a particularly simple design of the control arm. In particular, this design offers the advantage of simplifying the design of a wheel suspension in which the control arm according to the invention can be used, due to the symmetry properties of the control arm.

[0032] As mentioned above, the front pivot bearing axis is inclined relative to the pivot axis by a third angle with respect to a front transverse axis running in the main extension plane and perpendicular to the pivot axis through the center of the front body-side pivot bearing, while the rear pivot bearing axis is inclined relative to the pivot axis by a fourth angle with respect to a rear transverse axis running through the center of the rear body-side pivot bearing. In this configuration, the front pivot bearing axis and the rear pivot bearing axis are therefore rotated by a third and fourth angle, respectively, about the front and rear transverse axes and thus inclined relative to the pivot axis.The front and rear transverse axes (= pivot axes) run in the main extension plane of the control arm and are perpendicular to the body-side pivot axis and each pass through the center of the front body-side pivot bearing and the rear body-side pivot bearing, respectively.

[0033] When the front and / or rear pivot bearing axis is rotated around the respective front or rear transverse axis, the pivot bearing axes therefore run essentially transversely to the main extension plane and are inclined relative to the pivot axis in a direction perpendicular to the main extension plane.

[0034] The third and fourth angles can be specified without any particular restriction, provided that both have the same magnitude. According to the invention, the third angle is understood to be the angle formed by the front pivot bearing axis and the body-side pivot axis of the control arm when the front pivot bearing axis is rotated counterclockwise (i.e., in the mathematically positive sense) about the front transverse axis in a side view from the wheel-side mounting point to the front body-side pivot bearing. According to the invention, the fourth angle is understood to be the angle formed by the rear pivot bearing axis and the body-side pivot axis of the control arm when the rear pivot bearing axis is rotated clockwise (i.e., in the mathematically negative sense) about the rear transverse axis in a side view from the wheel-side mounting point to the rear body-side pivot bearing.

[0035] The rotation of the front pivot bearing axis about the front transverse axis and / or the rotation of the rear pivot bearing axis about the rear transverse axis offers the advantage of an additional degree of freedom in the design of the movement of the control arm according to the invention.

[0036] Preferably, the third angle is selected from the range of greater than 0° to about 25°, particularly preferably from about 5° to about 20°, and most preferably from about 6°. Preferably, the fourth angle is selected from the range of greater than 0° to about 25°, particularly preferably from about 5° to about 20°, and most preferably from about 6°.

[0037] Furthermore, the third and fourth angles each have the same value for a particularly simple design of the control arm. In particular, this design offers the advantage of simplifying the design of a wheel suspension in which the control arm according to the invention can be used, due to the symmetry properties of the control arm.

[0038] Particularly advantageous is that the rubber-elastic bearings exhibit a significantly lower axial stiffness than radial stiffness. Specifically, the axial to radial stiffness ratio is preferably approximately 1:10. This enables targeted toe-in control by utilizing the axial displacement in the rubber-elastic bearings when a force acts on them primarily in the longitudinal direction, i.e., in the axial direction.

[0039] Furthermore, the rubber-elastic bearings of the front and rear body-side pivot bearings can be designed differently with respect to their axial and / or radial stiffness. Thus, the tracking behavior of the control arm according to the invention can be varied over a wide range by specifying the elastic properties of the rubber-elastic bearings.

[0040] The control arm according to the invention is particularly advantageous due to its simple design, making it suitable for use in a wheel suspension for unsteered wheels of a motor vehicle, especially a rear wheel suspension. For this purpose, a front wheel-side pivot bearing and a rear wheel-side pivot bearing are provided at the wheel-side connection point. The front wheel-side pivot bearing and the rear wheel-side pivot bearing define a wheel-side pivot axis. A wheel carrier can be pivotally connected to the wheel-side pivot bearings.

[0041] The use of the control arm according to the invention in a rear wheel suspension of a motor vehicle offers the great advantage that the toe-in correcting property of the control arm according to the invention counteracts an oversteering tendency of the rear axle in the event of deceleration.

[0042] Further advantageous details and effects of the invention are explained in more detail below with reference to a preferred embodiment illustrated in the drawing, which is not to be understood as limiting. The drawing shows: Fig. 1 a perspective view of a preferred embodiment of the control arm according to the invention, Fig. 2 a top view of the wishbone Fig. 1, Fig. 3 a rear view of the wishbone Fig. 1, Fig. 4A and Fig. 4B a schematic representation of the effect of a longitudinal force acting on a wheel on a prior art control arm compared to the control arm according to the invention, and Fig. 5 a diagram showing the effect of rotation around the vertical axis during braking.

[0043] In the different figures, identical parts are always provided with the same reference symbols, so that they are usually only described once.

[0044] In the Fig. 1, Fig. 2 to Fig. Figure 3 shows an embodiment of a control arm 1 according to the invention in different views. The control arm 1 has a front pivot bearing 2 and a rear pivot bearing 3 on the body side. Rubber-elastic elements 4, in particular cylindrical rubber-elastic bushings 4, for example rubber-metal bushings, are received in the pivot bearings 2 and 3. The control arm 1 can be pivotally connected to a vehicle body or subframe (not shown in the figures) via the rubber-elastic bushings 4 or via the pivot bearings 2 and 3.

[0045] The longitudinal axis of the rubber-elastic bushing 4 of the front pivot bearing 2 defines the front pivot bearing axis 5 and the longitudinal axis of the rubber-elastic bushing 4 of the rear pivot bearing 2 defines the rear pivot bearing axis 6 ( Fig. 2) The rubber-elastic bushings 4 are soft in the axial direction and hard in the radial direction. In particular, the rubber-elastic bushings 4 are significantly softer in the axial direction than in the radial direction, so that their stiffness ratio axial to radial is approximately 1:10.

[0046] In its central section, the control arm 1 has mounting means for a coil spring 8 and a damping element 9. The coil spring 8 and the damping element 9 can be connected at their ends facing away from the control arm 1 to a vehicle body or subframe (not shown).

[0047] On the wheel side, the control arm 1 is provided with a front wheel-side pivot bearing 10 and a rear wheel-side pivot bearing 11. In the illustrated embodiment, the wheel-side pivot bearings 10 and 11 form the wheel-side connection point of the control arm 1. The pivot bearings 10 and 11 typically accommodate similar rubber-elastic bushings as those in the pivot bearings 2 and 3. A control arm 1 designed in this way is also referred to as a trapezoidal control arm.

[0048] The pivot bearing axes of the wheel-side pivot bearings 10, 11 are essentially aligned with one another and pivotably support a front connecting leg 13 and a rear connecting leg 14 of a wheel carrier 12, respectively. The wheel carrier 12 is also pivotably supported at its upper connecting leg 15 on an upper, essentially U-shaped link 16. The link 16 is pivotably connected at its end furthest from the wheel carrier 12 to the vehicle body (not shown) or the subframe. A [missing information - likely a component or element] is connected to the wheel carrier 12 in the Fig. 4A and Fig. The wheel 17 of a motor vehicle shown in Figure 4B can be rotatably connected. It is of course possible to arrange the aforementioned coil spring 8 and the damping element 9 on the wheel carrier 12.

[0049] In Fig. Figure 2 shows the pivot axis 23 of the control arm 1, which runs through the centers of the front and rear body-side pivot bearings 2, 3. In the illustrated embodiment, the front pivot bearing axis 5 forms a first angle 30 with the pivot axis 23. The front pivot bearing axis 5 runs essentially in the Fig. 3 recognizable main extension level 22 and is also in Fig. The visible front vertical axis 25 is rotated counterclockwise and thus inclined relative to the pivot axis 23. Similarly, the rear pivot bearing axis 6 is rotated clockwise about the rear vertical axis 26 and thus forms a second angle 31 with the pivot axis 23. The rear pivot bearing axis 6 also runs in the main extension plane 22 of the control arm 1 and is only inclined relative to the pivot axis 23 with respect to the rear vertical axis 26.

[0050] In the Fig. In the embodiment of the control arm 1 shown in Figure 2, the first angle 30 and the second angle 31 have the same magnitude. The extensions of their respective pivot bearing axes 5, 6 intersect at a point which, viewed from above, is laterally offset from the wheel axis 18.

[0051] Since the pivot bearing axes 5, 6 essentially run in the main extension plane 22, as already described above, it follows for the illustrated embodiment of the control arm 1 that the third and fourth angles (not shown) preferably have a value of 0°. However, the pivot bearing axes 5, 6 can also be angled about the angle shown in Fig. The transverse axes 27 and 28 shown in Figure 2 are rotated from the main extension plane 22 and are also inclined in this direction relative to the pivot axis 23. The invention advantageously makes it possible to position the pivot bearings with their pivot bearing axes 5, 6, or the rubber-elastic bushings 4, at the first and second angles 30, 31 and / or at the third and fourth angles relative to the pivot bearing axis 23.

[0052] As further in Fig. As can be seen in Figure 2, the front body-side pivot bearing 2, viewed in the longitudinal direction 20, is located further away from the wheel axle 18 than the front wheel-side pivot bearing 10. Furthermore, the rear body-side pivot bearing 3, viewed in the longitudinal direction 20, is located further away from the wheel axle 18 than the rear wheel-side pivot bearing 11. In addition, the body-side pivot axis 23 runs essentially parallel to the wheel-side pivot axis 24.

[0053] The Fig. 4A and Fig. Figure 4B schematically illustrates the effect of a longitudinal force 33 acting on the wheel 17, in particular a reverse braking force, both for a control arm 34 that does not have the features according to the invention and for the control arm 1 according to the invention. The in Fig. The control arm 34 shown in 4A differs from the one in Fig. The control arm 1 according to the invention, as shown in Figure 4B, differs in the orientation of its front body-side pivot bearing 35 and its rear body-side pivot bearing 36. In contrast to the control arm 1 according to the invention, the front pivot bearing axis 37 and the rear pivot bearing axis 38 of the control arm 34 are aligned with the pivot axis 23. All other features of the control arm 34 are otherwise identical to those of the control arm shown in Figure 4B. Fig. 1, Fig. 2 to Fig. 3 described embodiment of the control arm according to the invention 1.

[0054] Both the pivot bearings 2, 3 and the pivot bearings 10 and 11 of the control arm 1, as well as the pivot bearings 35, 36 of the control arm 34, have rubber-elastic bushings 4. The rubber-elastic bushings 4 also exhibit the elastic properties already described above, particularly with regard to their axial and radial stiffness; that is, they are significantly stiffer in the radial direction than in the axial direction.

[0055] If now, as in Fig. As shown schematically in Figure 4A, when a braking force 33 acts on the wheel 17 in the direction of the arrow, the front body-side pivot bearing 35 is pulled radially outwards and the rear body-side pivot bearing 36 is pushed radially inwards, as indicated by the corresponding arrows on the respective pivot bearings 35 and 36. Furthermore, the body-side pivot bearings 35 and 36 move rearwards along the pivot axis 23, as also indicated by the corresponding arrows. The radial load on the pivot bearings 35 and 36, and thus on the rubber-elastic bushings 4, leads to a rotational movement of the control arm 34, which is oriented counterclockwise in the plane of the drawing, and thus to a toe angle adjustment 39 of the wheel 17 in the toe-out direction.

[0056] In Fig. 4B is the same delay process as in Fig. 4A schematically illustrated. Because, in the control arm 1 according to the invention, the front body-side pivot bearing 2 and the rear body-side pivot bearing 3 are inclined relative to the pivot axis 23, as already shown in the Fig. 1, Fig. 2 to Fig. As explained in section 3, when braking force 33 acts on wheel 17, the front pivot bearing 2 moves essentially rearward and inward along its pivot bearing axis 5, as indicated by a corresponding arrow on the front pivot bearing 2. The rear pivot bearing 3, on the other hand, moves rearward and outward, as also shown by a corresponding arrow. This axial movement along the pivot bearing axes 5 and 6 of the pivot bearings 2 and 3 results in a rotational movement of the control arm 1, which is oriented clockwise in the plane of the drawing. This rotational movement leads to a toe-in adjustment of the wheel 17. This toe-in rotation is superimposed on the toe-out rotation resulting from the Fig. This is already known from the case described in 4A, since the front body-side pivot bearing 2 is also pressed radially outwards and the rear body-side pivot bearing 3 is pressed radially inwards. Overall, this results in the following in Fig. In the case shown in 4B, a corrected toe angle adjustment 40 of the wheel 17, which is at least smaller than the uncorrected toe angle adjustment 39 of the wheel shown in Fig. 4A shown control arm 34. By suitable design of the elastic properties of the rubber-elastic bushings 4 and by suitable specification of the first and second angles 30, 31, a rotational movement in the toe direction of the control arm 1 in the Fig. The deceleration case shown in 4B can be achieved, which more than compensates for the rotational movement in the toe-out direction and thus leads to a toe angle adjustment of the wheel 17 in toe-in.

[0057] With the in the Fig. 1, Fig. 2, Fig. 3 to Fig. The tracking behavior of the wheel 17 can be varied in a wide range by specifying the first and second angles 30, 31 and the elastic properties of the rubber-elastic bushings 4, as shown in Figure 4 of the control arms 1.

[0058] In a preferred embodiment, the control arm 1 is designed as a lower trapezoidal link of a wheel suspension for the unsteered wheels of a motor vehicle, in particular a rear wheel suspension.

[0059] In Fig.Figure 5 illustrates the effect of rotation about the vertical axis during braking, achievable with the invention, as an example CAE simulation. This represents brake force steering as a function of the rotation of the inner pivot bearings 2 and 3. The X-axis represents the rotation of the bushings or pivot bearings about the vertical axis (angle of attack) in [°]. Both bushings or pivot bearings were changed by the same amount. The Y-axis represents the tracking behavior during braking (brake force steering) in [° / kN]. It can be shown that the rotation has an advantageous effect and that there is an optimal angle of approximately 11° (arrow 41), where arrow 42 represents "less oversteer." The exemplary optimal value applies to a fixed distance between the pivot bearings 2 and 3, as well as to the distance between the pivot axes 23 and 24. Changing these geometric relationships will result in a slightly different optimal angle.The effect shown in accordance with the invention remains.

[0060] It is in accordance with the invention if the front and rear wheel-side pivot bearings 10 and 11, respectively, are adjusted accordingly to achieve the effects achievable with the invention. Therefore, either the rear pivot bearings 2 and 3 can be adjusted in coordination with the wheel-side pivot bearings 10 and 11, respectively, or the respective pivot bearings 2 and 3 or 10 and 11 can be adjusted independently. Reference symbol list: 1 wishbone 2 Front body-side swivel bearing 3 Rear body-side swivel bearing 4 rubber-elastic bushings 5 Front swivel bearing axle 6 Rear swivel bearing axle 7 8 coil springs 9 damping element 10 Front wheel-side swivel bearing 11 Rear wheel-side swivel bearing 12 bike carriers 13 Front attachment leg 14 Rear attachment leg 15 Upper attachment leg 16 Upper control arm 17-inch wheel 18 wheel axle 19 20 Longitudinal direction 21 Transverse direction 22 Main extent level 23 Body-side swivel axis 24 Wheel-side swivel axle 25 Front vertical axis 26 Rear vertical axis 27 Front transverse axis 28 Rear transverse axle 29 30 First Angle 31 Second Angle 32 33 Longitudinal force, braking force 34 Second wishbone 35 Front body-side swivel bearing 36 Rear body-side swivel bearing 37 Front swivel bearing axle 38 Rear swivel bearing axle 39 Uncorrected toe angle adjustment 40 Corrected toe angle adjustment 41 Arrow (example, optimal angle of attack) 42 Arrow “less oversteer”

Claims

[1] A wishbone for a wheel suspension comprising a front body-side pivot bearing (2) and a rear body-side pivot bearing (3) and a wheel-side attachment point, wherein the pivot bearings (2, 3) define a body-side pivot axis (23), and wherein a front wheel-side pivot bearing (10) and a rear wheel-side pivot bearing (11) are provided at the wheel-side attachment point, wherein the front and the rear wheel-side pivot bearings (10, 11) define a wheel-side pivot axis (24), wherein the body-side pivot axis (23) is parallel to the wheel-side pivot axis (24), characterized by, that a front pivot bearing axis (5) of the front body-side pivot bearing (2) and a rear pivot bearing axis (6) of the rear body-side pivot bearing (3) are inclined relative to the body-side pivot axis (23), wherein the front pivot bearing axis (5) is inclined relative to the body-side pivot axis (23) by a first angle (30) with respect to a front vertical axis (25) passing through the center of the front body-side pivot bearing (2) and perpendicular to a principal extension plane defined by the body-side pivot axis (23) and the wheel-side attachment point, and the rear pivot bearing axis (6) is inclined relative to the body-side pivot axis (23) by a second angle (31) with respect to a rear vertical axis (26) passing through the center of the rear body-side pivot bearing (3), wherein the first angle (30) and the second angle (31) have the same magnitude,and wherein the front pivot bearing axis (5) is inclined relative to the body-side pivot axis (23) by a third angle with respect to a front transverse axis (27) extending in the main extension plane and perpendicular to the body-side pivot axis (23) through the center of the front body-side pivot bearing (2), and the rear pivot bearing axis (6) is inclined relative to the body-side pivot axis (23) by a fourth angle with respect to a rear transverse axis (28) extending through the center of the rear body-side pivot bearing, and wherein the third angle and the fourth angle have the same magnitude. [2] Control arm according to claim 1, characterized by , that the first angle (30) and / or the second angle (31) are acute angles. [3] Control arm according to any one of the preceding claims, characterized byrubber-elastic bushings (4) whose axial stiffness is significantly smaller than their radial stiffness, wherein the stiffness ratio axial to radial is preferably about 1:

10. [4] Use of the control arm according to one of the preceding claims in an independent wheel suspension for the unsteered wheels of a motor vehicle, in particular a rear wheel suspension.

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