WO2009003453A1 - Twist-beam rear axle - Google Patents

Abstract

The problem addressed by the invention is to propose a twist-beam rear axle having improved driving performance, in particular when cornering. For this purpose, a twist-beam rear axle (10) for a vehicle is proposed, wherein the vehicle can be positioned on an underlying surface (9) and has a vehicle longitudinal direction, with two longitudinal control arms (2a, b) having a coupling element (4) which is situated transversely and couples the two longitudinal control arms (2a, b) to each other, and with two wheel mounts (7), wherein the end region of each longitudinal control arm (2a, b) bears one of the wheel mounts (7), characterized by pivoting means which are designed and/or arranged such that, in the installed state of the twist-beam rear axle (10), the wheel mounts (7) are accommodated such that they can be pivoted relative to the respectively assigned longitudinal control arms (2a, b) about pivot axes (8) aligned and/or alignable vertically, in side view, with respect to the underlying surface (9).

Description

 Name of the invention

Beam axle

description

Field of the invention

The invention relates to a torsion beam axle for a vehicle with two trailing arms, with a transverse coupling element, which couples the two trailing arms together, and with two wheel receivers, each trailing arm carries one of the wheel receivers at its end.

The known twist-beam axles usually have a frame, which consists essentially of two torsion-resistant and rigid side members, which are connected to one another via a likewise rigid but torsionally soft profile body. Such torsion beam axles are known since the ^Λ 70s and captivate with a simple, lightweight, space-saving and at the same time cost-effective design.

In the driving application, a good straight-line running behavior of the torsion-beam axle is achieved by the fact that both longitudinal members guide their wheel very rigidly in the longitudinal direction and, in the case of equilateral compression and rebound, with the profile Swing body like a horizontal pendulum around the pivot points on the floor of the vehicle without changing the gauge. In mutual springing, such as in a curve, the profile body twists and compensates for height differences between the two side members, whereby both wheels spring almost independently of each other and keep very good ground contact.

The object of the invention is to propose a torsion beam axle with an improved driving behavior, in particular when cornering.

This object is achieved by a torsion beam axle with the features of claim 1. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the figures.

According to the invention, a torsion beam axle for a vehicle is disclosed, which has two trailing arms, which are preferably designed torsionally and / or rigidly rigid, and are aligned in the installed state in or substantially in the vehicle longitudinal direction. A transverse coupling element, which is aligned in a transverse direction perpendicular to the longitudinal extent and / or parallel to a background of the vehicle, is designed for the particularly rigid and / or torsionally flexible coupling of the two trailing links. Trailing arm and coupling element form a Len- kerrahmen, which is articulated in the region of the coupling element and / or in the coupling element region of the trailing arm on a vehicle and / or articulated. At the free end portions of the trailing arm wheel receivers are provided, which are designed to receive a wheel.

In the context of the invention, pivoting means are proposed, which are designed and / or arranged, so that the wheel receivers are vertically or substantially vertically aligned in side view or top view. directed and / or alignable pivot axes are pivotally received in the end region of the trailing arm relative to the trailing arms. Thus, the pivot axes in a direction perpendicular to the ground and parallel to the vehicle longitudinal extension arranged projection plane are largely aligned vertically aligned or aligned. The pivot means are designed so that they act at least functionally between the wheel and the trailing arms and preferably only allow a small swing angle of magnitude total less than 10 ° for each wheel.

With the embodiment according to the invention, the wheel receivers receive an additional degree of freedom of movement, namely a pivoting possibility about the pivot axis, so that the wheel receivers can be pivoted or adjusted relative to the trailing arms.

In the invention, it was recognized that the known twist-beam axle has a self-steering behavior, especially when cornering, which can lead to oversteer of the vehicle and - in the worst case - to a breaking out of the rear of the vehicle. This self-steering behavior is justified by the fact that the known torsion beam axle is deformed by the side forces acting on cornering in cornering such that a curve outside wheel has a toe and a curve-inside wheel has a toe. Thus, the known twist beam axle is deformed so that the wheels steer in cornering to turn outside.

As a result of the development according to the invention, the connection of the wheel receptacles to the trailing arm is designed such that a pivot axis is arranged which pivots the wheel receptacle about the pivot axis under side force influence and counteracts the deformation-related change in the wheel position relative to the vehicle longitudinal axis and / or this compensates. In this way, a torsion beam axle with passive steering behavior is created, which is the typical oversteer of Twist-beam axles can compensate in curves. The invention preferably converts a parallelogram-like kinematics, the trailing arms forming the guide links and the wheel receivers forming the correction links.

In a preferred embodiment of the invention, the pivot means are formed and / or arranged so that the wheel receivers are positively guided about the pivot axes. In particular, the pivot axis is fixed relative to the associated trailing arm, so that changes depending on the deflection of the trailing arm of the vertical angle of the pivot axis in the vehicle longitudinal direction and sets a different behavior of the wheel when occurring lateral forces.

In a particularly preferred embodiment, the pivot means are coupled to an elastic means for sprung and / or resilient pivoting. In particular, the elastic device is designed as a spring-damper element which counteracts the lateral forces, that is to say the actuating force of the pivot axis. The elastic device and / or the spring-damper element can also be used to tune the characteristics of the pivoting means and thus the torsion beam axle.

The pivot means are preferably designed so that in a neutral position of the trailing arm, the pivot axis passes through the Radaufstandspunkt. Alternatively, the pivot axis extends in a projection in a projection plane parallel to the vehicle longitudinal extension and perpendicular to the ground through the wheel contact point, so that the pivot axis can optionally be inclined towards the vehicle center or away (spread). Likewise, the pivot axis at the same time or independently of the above spread have a caster or lead angle. In a preferred development of the invention, the torsion-beam axle is designed in such a way that, in a deflected position of the trailing arm, the assigned pivot axis in the forward driving direction pierces the ground behind the wheel contact point, referred to below as track point, so that the track point is arranged behind the wheel contact point. This situation occurs, for example, when the outside wheel cushions during cornering and is due to the inclination of the pivot axis in advance. The occurring lateral force engages due to the position of the pivot axis in the forward direction in front of the pivot axis on the wheel and pushes the wheel "in" the curve, thus ensuring a Mitlenken.

Further, it is preferred that in an extended position of the trailing arm, the pivot axis in the forward direction pierces the ground in front of the Radaufstandspunkt so that the track point is located in front of Radaufstandspunkt. This situation arises for example when cornering at the inside wheel, which rebounds and shows a caster. In this situation, the side force in the forward direction behind the pivot axis attacks and pushes the wheel "out" of the curve.

In particular, the torsion beam axle is designed so that when cornering due to the self-steering behavior of the inside and the outside wheel a toe is achieved, that is, the distance of the rim inner edges of the wheels in height of the wheel center in the forward direction at the front wheel is smaller than at the Radhinterseite.

In one possible embodiment, the pivot means are designed so that the pivot axis always, in particular in each Einfederungslage the trailing arm or the wheels, passes through the center of a wheel bearing of the wheel. In this case, the torsion beam axle is designed so that each intersect the pivot axis and the axis of rotation of a wheel. In one possible embodiment, the wheel receptacle is formed as an outer ring of a rolling bearing, which is connected to the trailing arm via elastic means or joints. This possible embodiment has the advantage that the structure is simple and uncomplicated.

However, since it can not be ruled out due to the kinematics that in the described arrangement, the wheels in a cornering go in an adverse fall, that is, the outside wheel enters a positive and the inside wheel into a negative fall, it is alternatively proposed that the pivot axis of the pivot means always runs outside the center of a wheel bearing of the wheel. In particular, the torsion-beam axle is designed in such a way that, in the extension direction of the longitudinal member, the pivot axis extends in the forward direction behind the center of the wheel bearing of the wheel receptacle.

This development, wherein the pivot axis extends behind the center of the wheel and is inclined in a vertical angle in the vehicle longitudinal direction relative to the vertical (caster angle), has the advantage that due to the resulting from the arrangement caster when cornering for the outside wheel a stronger ins Negative walking fall sets.

Since a negative camber would also be better for the driving wheel due to the caster angle in this development, a positive camber would also be optionally proposed for all embodiments as an option to block or accomodate the elastic device for suspension of the wheel receptacle on the inside wheel stiffen. As a criterion for blocking or stiffening the elasticity, the transverse displacement of the trailing arm under side force influence or the angular difference of the deflection of the trailing arm can be used. Likewise, the elastic device may be blocked or stiffened when driving straight ahead and be activated while cornering on the outside wheel.

In a preferred structural implementation of the torsion beam axle, the pivot means are formed as an integral part of a wheel bearing. Also preferably, the pivot means are realized as a hinge. The pivoting of the pivot axis is preferably via elastically deformable elements or via hinge elements, such. Ball heads, sliding bushes or rolling bearings.

In a preferred embodiment of the pivotable wheel receiving the pivot axis is defined by two spaced pivoting means.

For suspension, either the elasticity of the hinge elements and / or spring elements based on steel and / or rubber elements are used.

Likewise, the components used anyway can serve as eistische elements.

The required damping of the system can be realized via separate damper elements or via the damping properties of the components used.

In a preferred embodiment, an outer ring of the wheel bearing is realized as a wheel flange. In this way, the improved torsion beam axle can be formed by inserting into a conventional or adapted twist beam axle a novel wheel bearing which provides the pivot axis as additional functionality. Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention. Showing:

Figure 1, 2 a torsion beam axle according to the prior art for illustrating the self-steering behavior of such Achsverbünde;

FIG. 3 shows a first exemplary embodiment of a torsion-beam axle according to the invention in a schematic plan view and schematic side view in different injection states;

FIG. 4 shows the torsion beam axle in FIG. 3 in a representation analogous to FIG. 2;

Figure 5 shows a second embodiment of a torsion beam according to the invention in the same representation as in Figure 3;

FIG. 6 shows the torsion beam axle in FIG. 5 in plan view for illustrating the mode of operation;

FIG. 7 shows a schematic 3D representation of the torsion-beam axle in FIG. 3 in a neutral position and in one

Cornering;

Figure 8 is a schematic 3D representation of the torsion beam axle in Figure 5 in a neutral position and in cornering. Corresponding or identical parts are each provided with the same reference numerals in the figures. In FIGS. 4 and 6, analogous to FIG. 2, a kinematic reversal has been inserted for the sake of simplicity. The pivot axis is shown geometrically analogous to the neutral position; the forces are each shifted to the kinematic required location.

FIG. 1 shows a torsion-beam axle 1, as known from the prior art. The torsion beam axle 1 has two trailing arms 2 a, b, which are connected to a vehicle, not shown, via a joint 3. In the transverse direction to the vehicle, not shown, a coupling element in the form of a Torsionsprofils 4, which is connected to the trailing arms 2 a, b extends. In each case at the free ends of the trailing arm two wheel receivers for wheels 5 a, b are arranged.

FIG. 2 shows the torsion-beam axle 1 in FIG. 1 during cornering in a right-hand curve according to arrow 6, the dynamic deformations being illustrated in an exaggerated manner. Due to the effective lateral forces FSA on the outside wheel and F _S ι on the inside wheel, the trailing arms 2 a, b are deflected in the direction of the center of the curve about the joints 3. Since trailing arm 2 a, b and wheels 5 a, b are torsionally stiff to each other, the lateral forces or the deflection of the trailing arm 2 a, b cause the on the outside wheel 5a Nachspur and on the inside wheel 5 b toe sets, so that the wheels 5 a, b steer to the outside of the curve and oversteer the vehicle.

The aim of the new torsion beam axle is to avoid the described oversteer by balancing the tracking error resulting from the compliance of the torsion beam axle. 3 shows a schematic representation of a first embodiment of the invention in the form of a torsion beam axle 10, which is shown in the figure 3 in sections in the upper region in plan view. Schematically, in this illustration, a joint 3 for articulating the connecting link axle 10 on a vehicle, not shown, and a trailing arm 2 is shown, which carries at its free end a wheel mount 7 with a wheel 5. Also only indicated is a torsion profile 4, which connects the trailing arm 2 shown with a trailing arm, not shown, rigid and torsionally soft.

The wheel receiver 7 and thus the wheel 5 are pivotally mounted relative to the trailing arm 2 about a pivot axis 8, wherein the pivot axis 8 is perpendicular or substantially perpendicular to a substrate 9 on which the vehicle or the wheels 5 run arranged. The pivot axis 8 is fixed relative to the trailing arm 2, so that the wheel 5 or the wheel receptacle 7 relative to the trailing arm 2 via the pivot axis 8 is pivotally suspended and resiliently via elastic means 11.

In the center of FIG. 3, the torsion beam axle 10 is shown in a neutral position 12 relative to the base 9, the trailing arm 2 being aligned parallel or substantially parallel to the ground 9. In this neutral position 12, the pivot axis 8 extends through the center of the wheel receptacle 7 or wheel bearing and by a Radaufstandspunkt 13, which denotes the point of contact between the wheel 5 and 9 base.

Arranged above is a representation of the same construction, but with the wheel 5 being compressed, as occurs, for example, in the case of a curve-outside wheel 5a. The fact that the pivot axis 8 is rigidly connected to the trailing arm 2 a, this is pivoted together with the trailing arm 2 a to the joint 3, so that the pivot axis 8 while still through the center or center of rotation of the wheel 7 and the wheel bearing runs, but the ground 9 in the forward direction 14 behind the Radaufstandspunkt 13 in track point 15 pierces. A side or lateral force F _SA acting in the curve engages in the forward direction 14 in front of the pivot axis 8, so that the wheel 5 a is pressed into the curve.

In the lower portion of Figure 3, the structure is shown in the same representation with a spring-loaded wheel 5, as it occurs, for example, as a curve-inner wheel 5 b. In this situation, the pivot axis 8 - as in all situations - passes through the center of the wheel bearing or the wheel 7, but pierces the ground 9 in forward direction 14 in front of the wheel contact point 13 in the track point 15. Here now acts a lateral or lateral force F _S ι on the wheel 5 b, it engages behind the pivot axis 8 and pushes the wheel out of the curve.

As a result, when cornering, the wheels 5 a, b are brought into a toe, so that the vehicle stabilizes on the torsion beam axle 10.

FIG. 4 shows the torsion beam axle in FIG. 3 in a schematic plan view similar to the torsion beam axle 1 in FIG. 2 during cornering. From this representation it can be seen that the wheels 5 a, b are pivoted about the pivot axes 8 due to the lateral forces acting, so that the toe-in is adjusted in the manner described.

FIG. 5 shows, in the same representation as FIG. 3, a second exemplary embodiment of a torsion beam axle 10, which differs substantially from the torsion beam axle 10 in FIG. 3 in that the pivot axle 8 extends in the forward direction 14 behind the center of the wheel mount 7. This arrangement, in contrast to the arrangement of Figure 3 has the advantage that the fall of the wheels 5 a, b is formed cheaper, since in the arrangement of Figure 3, the outside wheel 5 a positive and the inside wheel a negative camber occupies. As can be seen from FIG. 5, the pivot axis 8 extends in the neutral position 12 behind the center of the wheel bearing and penetrates the base 9 in the wheel contact point 13. In contrast to the embodiment in FIG. 3, however, the embodiment in FIG. 4 shows a caster angle alpha.

In the case of the outer wheel 5 a this is analogous to the embodiment in Figure 3 in advance, so that the wheel 5 a is pressed by the side force in the curve. In contrast to the variant in FIG. 3, however, the caster angle alpha leads to a more negative fall.

The inside wheel 5 b is also pressed out of the curve and thus provides in conjunction with the outside wheel 5 for the toe already described.

FIG. 6 shows the torsion beam axle 10 in FIG. 5 in a plan view, wherein the kinematics is again visualized. In a starting position or neutral position 12 trailing arm 2 a, b and wheels 5 a, b to each other at a predetermined angle, in particular arranged parallel to each other. The wheels 5 a, b are each connected via one of the pivot axes 8 and one of the elastic means 11 with the corresponding trailing arm 2 a, b. When cornering according to arrow 6, the trailing arm 2 a, b are deflected in the direction of the curve inside around the joints 3. The side forces F _S A and F _S acting on the wheels 5 engage the outside wheel 5 a in the forward direction 14 in front of the pivot axis 8, whereas in the case of the inside wheel 5 b the lateral force F _S ι in the forward direction 14 behind the pivot axis 8 acts, so that explained in connection with the figure 5 self-steering hold is generated.

FIGS. 7 and 8 again show the torsion beam axle 10 in FIGS. 3 and 5 in a schematic 3D representation, the dotted lines showing the torsion beam axle 10 in neutral position 12 and the solid lines in cornering when cornering according to arrow 6. to Explanation is made to the above illustration. Optionally, the lintel behavior of the respective inner wheel 5 b is improved by the fact that the inside wheel 5 b is actively prevented from swinging.

LIST OF REFERENCE NUMBERS

1 known twist beam axle

2 a, b trailing arm 3 joint

4 torsion profile

5 a, b wheels

6 arrow

7 Radaufnahme 8 pivot axis

9 underground

10 torsion beam axle according to the invention

11 elastic device

12 neutral position 13 wheel contact point

14 forward direction

15 track point (puncture point pivot axis - roadway)

Claims

claims 1. Twist beam axle (10) for a vehicle, wherein the vehicle is positionable on a substrate (9) and has a vehicle longitudinal direction, with two trailing arms (2 a, b), with a transverse coupling element (4), which the two trailing arms (2 a, b) coupled to each other, and with two wheel receivers (7), each trailing arm (2 a, b) at its end portion of the Rad- receptacles (7) carries, characterized by Pivoting means, which are formed and / or arranged, so that in an installed state of the torsion beam axle (10) the wheel receivers (7) in side view vertically to the ground (9) aligned and / or alignable pivot axes (8) relative to the respective associated trailing arms (2 a, b) are pivotally received. 2. Twist-beam axle (10) according to claim 1, characterized in that the pivot means are formed and / or arranged so that the wheel receivers (7) are forcibly guided about the pivot axis (8). 3. Twist-beam axle (10) according to claim 1 or 2, characterized in that the pivot means are coupled to an elastic means (11) for spring-loaded pivoting. 4. Twist-beam axle (10) according to claim 2, characterized in that the elastic means (11) is sprung harder in a pivoting direction than in the other pivoting direction. 5. Twist-beam axle (10) according to one of the preceding claims, characterized in that in a neutral position (12) of the Trailing arm (2 a, b), wherein the trailing arm (2 a, b) are aligned to the substrate (9) such that the pivot axes (8) of the pivot means through or outside the Radaufstandspunkte (13). 6. Twist-beam axle (10) according to one of the preceding claims, characterized in that in a sprung position of the trailing arm (2 a), the pivot axis (8) of the pivot means in the forward direction (14) behind the Radaufstandspunkt (13) is arranged. 7. Twist-beam axle (10) according to one of the preceding claims, characterized in that in a rebounded position of the trailing arm (2 b), the pivot axis (8) in the forward direction (14) in front of the wheel contact point (13) is arranged. 8. Twist-beam axle (10) according to one of the preceding claims, characterized in that the pivot axis (8) of the pivot means always through the center of a wheel bearing of the wheel (7) extends. 9. twist beam axle (10) according to one of claims 1 to 6, characterized in that the pivot axis (8) of the pivot means always outside the center of a wheel bearing of the wheel (7) extends. 10. Twist-beam axle (10) according to one of claims 1 to 6, characterized in that the pivot axis (8) of the pivot means an angle to the perpendicular to the road surface describes, in particular a pre-, caster and / or spread angle describes. 11. Twist-beam axle according to claim 8 or claim 9, characterized in that the pivot axis (8) of the pivot means in the extension direction of the longitudinal member (2 a, b) in the forward direction direction (14) behind the center of the wheel bearing is arranged. 12. Twist-beam axle (10) according to one of the preceding claims, characterized in that the pivot means are formed as an integral part of a wheel bearing or as an integral part of the longitudinal handlebars of the torsion beam axle. 13. Twist-beam axle (10) according to claim 11, characterized in that an outer ring of the wheel bearing is formed as a wheel flange. 14. Twist-beam axle (10) according to one of the preceding claims, characterized in that adjusts a negative fall at lateral force on the outside wheel. 15. Twist-beam axle (10) according to one of the preceding claims, characterized in that adjusts the lateral force toe-in on the rear wheels. 16. Twist-beam axle (10) according to one of the preceding claims, characterized in that adjusts a lateral toe and a negative camber on the outside wheel at the same time. 17. Twist-beam axle (10) according to one of the preceding claims, characterized in that the elastic means (11) is blocked or stiffened to the suspension of the wheel on the inside wheel wheel. 18. twist beam axle (10) according to the preceding claim, characterized in that is used as a criterion for blocking or stiffening the elasticity of the transverse displacement of the trailing arm under side force influence or the angular difference of the deflection of the trailing arm. 19. Twist-beam axle (10) according to one of the preceding claims, characterized in that the elastic means (11) is blocked or stiffened when driving straight ahead and / or is activated when cornering on the outside wheel.