WO2017137185A1

WO2017137185A1 - Steerable twist-beam rear suspension

Info

Publication number: WO2017137185A1
Application number: PCT/EP2017/050295
Authority: WO
Inventors: Benjamin Bäumer; Knut Heidsieck
Original assignee: Zf Friedrichshafen Ag
Priority date: 2016-02-10
Filing date: 2017-01-09
Publication date: 2017-08-17
Also published as: DE102016201994A1

Abstract

The invention relates to a steerable twist-beam rear suspension (1) for a vehicle, comprising two longitudinal control arms (2, 2a) arranged spaced apart from one another, on which one wheel carrier (3, 3a) each is arranged about one steering axle (4, 4a) each in a pivotable manner, a twistable transverse profile (5) that connects the two wheel carriers (3, 3a) to one another, and an adjusting device (6) connected to the wheel carriers (3, 3a) for pivoting the wheel carriers (3, 3a) about the steering axes (4, 4a). The adjusting device (6) has an actuator (7) and two each tie rods (8, 8a) connected to one of the two wheel carriers (3, 3a) in an articulated manner, wherein the tie rods can be actuated by means of the actuator. According to the invention, the actuator (7) is exclusively fastened to the transverse profile (5), and in terms of drive, is connected to the end of each of the tie rods (8, 8a) that is facing away from the respective wheel carrier (3, 3a).

Description

Steerable torsion beam axle

The invention relates to a steerable torsion beam axle for a vehicle,

comprising two spaced-apart trailing arms, on each of which a wheel carrier is pivotally mounted about a respective steering axis, a the two trailing arms interconnecting, twistable transverse profile, and connected to the wheel carriers adjusting device for pivoting the wheel about the steering axes, wherein the adjusting device is an actuator and two each articulated to one of the two wheel carrier tie rods and wherein the tie rods by means of the actuator are actuated.

On small and middle-class vehicles with front-wheel drive, mainly composite beam axles are used as the rear axle. It is a cost-effective and space-saving design that is easy to mount on the vehicle. Twist-beam axes essentially have a cross member suspended from the chassis via support arms with trailing arms formed thereon. A torsionally soft design of the cross member ensures that a defined mutual entanglement of the wheel carrier receiving trailing arm is made possible. Incidentally, the torsionally soft cross member assumes the function of a roll stabilizer with which a high roll stability, ie a desired build-up slope when cornering, can be achieved. Other benefits of

Twist beam axle is a good directional stability and low toe-in changes during compression and rebound of the axle.

From DE 10 2011 082 768 A1 a steerable torsion beam axle for a motor vehicle is known. The steerable torsion beam axle comprises two trailing arms arranged at a distance from one another, on each of which a wheel carrier is arranged so as to be pivotable about a respective steering axle. Furthermore, the steerable torsion beam axle comprises a twistable transverse profile interconnecting the two trailing arms and an adjusting device connected to the wheel carriers for pivoting the wheel carriers around the steering axles. The adjusting device comprises an actuator and an actuatable with the actuator, each articulated to one of the two wheel tie rod. The actuator of the actuator is on attached to one of the two trailing arms and thereby supported on one side of the trailing arm. Using this steerable beam axle as

Rear axle can be created a dynamic four-wheel steering for motor vehicles.

An object of the invention is to provide a steerable torsion beam axle with a reduced number of components and reduced system elasticity.

This is solved by the independent claim. advantageous

Embodiments are in particular in the dependent claims

which, taken alone or in various combinations with each other, may constitute an aspect of the invention.

A steerable torsion beam axle according to the invention for a vehicle comprises two trailing arms arranged at a distance from one another, on each of which a wheel carrier is pivotally mounted about a respective steering axis, a twistable transverse profile connecting the two trailing arms, and an adjusting device connected to the wheel carriers for pivoting the wheel carriers around the wheel steering axles. The adjusting device comprises at least one actuator and two each connected articulated to one of the two wheel tie rods, wherein the tie rods by means of the actuator can be actuated. The actuator is attached to the transverse profile and drivingly connected directly to a remote from the respective wheel carrier end of each of the tie rods.

At the present steerable torsion beam axle, the actuator is mounted on a trailing arm exclusively on the transverse profile instead. In addition, the actuator engages directly on each of the two tie rods, which are fixed with their other ends pivotally mounted on the respective wheel carrier, which is pivoted by a longitudinal movement of the associated tie rod about the respective steering axis. There are no additional components required to guide the tie rod, as proposed for example with DE 10 2011 082 768 A1, or to connect the tie rod indirectly via movable coupling elements with the actuator, as for example with EP 1 538 066 A1 is proposed. Consequently, the steerable beam linkage according to the invention can be manufactured using a smaller number of components and thus lighter weight and cost-effective.

In comparison with the present steerable torsion beam axle, the steerable torsion beam axle according to EP 1 538 066 A1 has an adjusting device with a larger number of components connected to one another via elastic bearings. As a result, the steerable torsion beam axle according to EP 1 538 066 A1 has a higher system elasticity than the steerable one according to the invention

Twist-beam axle on. Thus, with the steerable according to the invention

Twist-beam axle or its adjusting device achieves a higher efficiency, a higher track rigidity and an improved transverse rigidity.

The fact that the actuator is drivingly connected directly to the two tie rods, should primarily mean that the power transmission from the actuator to the

Tie rods no movably arranged coupling elements in the form of levers, links or the like are present.

The actuator is preferably designed electromechanically. The actuator can be used to generate the required force with or without a slow

be formed translating gear which is drivingly connected to an electric motor of the actuator. Alternatively, the actuator may be formed hydraulically or pneumatically.

The vehicle may be, for example, a passenger car, in particular a sporty compact vehicle (SUV) or a combination vehicle (station wagon), or a van.

According to an advantageous embodiment, the actuator is arranged approximately, preferably exactly, centrally on the transverse profile. This allows a more even

Weight distribution so as not to affect the properties of the steerable beam steering axle by an asymmetrical arrangement of the actuator on the rest of the steerable beam steering axle. According to an advantageous embodiment, a double-acting actuator of the actuator engages each of the tie rods. This makes it possible, in particular, to drively connect the actuator directly to each of the two tie rods. The actuator may comprise a housing provided with an electromechanical drive or hydraulic cylinder, wherein in the hydraulic cylinder a

double-acting piston provided with two piston rods is arranged. In an electromechanical drive is by an electric motor via a

Spindle nut one spindle adjusted linearly. The two tie rod ends are each articulated at the end of each one of the piston rods or the ends of the spindle.

A further advantageous embodiment provides that the transverse profile is formed by a partially inwardly along its longitudinal extent formed tube and at least partially in cross-section U-shaped, wherein the actuator is attached via at least one fastening unit on the transverse profile, which has a profile section of Encloses transverse profiles and has a shape that is adapted to the shape of the profile section. Preferably is between

Mounting unit and profile section provided an elastic intermediate layer. By this type of attachment of the actuator to the transverse profile are the

Properties, in particular torsion properties, of the transverse profile largely unaffected. On the other hand, the actuator does not need to absorb torsional forces.

Due to the partial U-shaped configuration of the cross section of the transverse profile, the torsion properties of the transverse profile are improved without the required

Reduce bending stiffness of the cross profile. In particular, the transverse profile is torsionally softer than a tubular transverse profile due to the partially U-shaped configuration of the cross section of the transverse profile. The fastening unit encloses the deformed profile section of the transverse profile radially outward. That the shaping of the

Fastening unit is adapted to the shape of the deformed profile section, may mean that a cross-section of the fastening unit in the

Is substantially true to scale enlargement of the cross section of the deformed profile section. The fastening unit can, for example, have two positive, and / or cohesively connectable fasteners. The actuator can also have two or more corresponding ones

Attachment units may be attached to the transverse profile, which may be arranged immediately adjacent or spaced from each other.

Advantageously, between the fastening unit and the deformed profile section at least one elastic, preferably elastomeric,

Damping element arranged. As a result, mechanical vibrations of the transverse profile are transmitted only attenuated to the actuator, and vice versa. This goes in particular with a reduction of operating noise of the steerable

Twist-beam axle accompanied. In addition, the life of the actuator is not affected by excessive mechanical vibrations. The damping element may have a shape in cross section, which is also adapted to the shape of the cross section of the transverse profile or the fastening unit. The damping element, the deformed profile section in the region of

Enclose the fastening unit in a form-fitting manner. This allows the

Mounting unit are mounted on the damping element floating on the cross profile.

According to an alternative further advantageous embodiment, it is provided that the cross-section is at least partially V-shaped in cross-section, is arranged to open in the direction of the actuator and has two in cross section at an angle to each other and interconnected leg, wherein the actuator via at least one Fastener is attached to the legs. As a result of this type of fastening of the actuator to the transverse profile, the properties, in particular torsion properties, of the transverse profile are as far as possible not impaired. By the at least partially V-shaped

Training the transverse profile, the cross-section has good torsional properties and a suitable bending stiffness. Each fastener may be bolted to the respective leg, for example. The actuator may also be attached to at least one of the legs via two or more corresponding fastening elements. Advantageously, at least one fastening element is supported at least partially via at least one elastic, preferably elastomeric,

Damping element on the respective leg from. As a result, mechanical vibrations of the transverse profile are transmitted only attenuated to the actuator, and vice versa. This is associated in particular with a reduction of operating noise of the steerable torsion beam axle. In addition, the life of the

Actuator not affected by excessive mechanical vibrations. The damping element can form a bearing point on the respective leg, so that the respective fastening element is mounted in a floating manner on the respective leg via the damping element.

According to a further advantageous embodiment, the steerable

Twist-beam axle at least one at least partially within one

Actuator facing arranged, V-shaped recess of the

Cross profile extending and connected to the trailing arms

Stabilizing element. As a result, the bending stiffness and the

Torsional stiffness of the steerable beam axle increased.

It is further advantageous if the stabilizing element is tubular. As a result, the stabilizing element is given a high flexural rigidity and a desired torsional rigidity. This can do that

Stabilizing element with lower material requirements, so be made lighter than a stabilizing element with a shape, the stabilizing element a lower bending stiffness and a lower

Gives torsional rigidity.

The invention is not limited to the specified combination of the features of

independent claim and the dependent claims limited. In addition, there are further possibilities of combining individual features, in particular if they result from the patent claims, the following description of the exemplary embodiments or directly from the figures. Preferred embodiments of the invention will be explained in more detail with reference to the accompanying figures. These show:

Fig. 1 is a schematic and perspective view of a first

Embodiment of a steerable according to the invention

Beam axle;

2 shows a cross section through a cross member of an embodiment of a steerable torsion beam axle according to the invention; in which the cross member is designed as a U-shaped profile,

Fig. 3 is a schematic, detailed perspective view of a

Embodiment of a steerable according to the invention

Beam axle; in which the cross member is likewise designed as a U-shaped profile,

Fig. 4 is a schematic and perspective view of a second

Embodiment of a steerable according to the invention

Beam axle;

Fig. 5 shows a cross section through a cross member schematic sectional view of another embodiment of a steerable according to the invention

Beam axle; wherein the cross member is formed as a V-shaped profile, and

Fig. 6 is a schematic, detailed perspective view of a

Embodiment, which substantially with that of Figure 5

matches.

In the figures, the same or functionally identical components with the same

Provided with reference numerals. 1 shows a schematic and perspective illustration of an exemplary embodiment of a steerable torsion beam axle 1 according to the invention for a vehicle, not shown. The steerable torsion beam axle 1 should be steerable

Rear axle of the vehicle to be used.

The steerable torsion beam axle 1 comprises two trailing arms 2 and 2a which are arranged at a distance from each other and which serve as a cross member

Cross profile 5 are connected to each other. In addition, a respective wheel carrier 3 and 3a is pivotally mounted on the respective trailing arm 2 and 2a via a respective steering axis 4 and 4a. The two steering axles 4 and 4a extend at an angle to the vertical axis and thus give a spread and thus a camber when wheels are rotatably mounted on the wheel. The twistable cross-section 5 assumes the function of a roll stabilizer. The cross-section 5 may be formed by a partially inwardly along its longitudinal extent formed tube and formed at least partially in cross-section U-shaped.

In addition, the steerable torsion beam axle 1 comprises an adjusting device 6 connected to the wheel carriers 3 and 3a for pivoting the wheel carriers 3 and 3a about the steering axles 4 and 4a. The adjusting device 6 comprises an actuator 7 and two actuatable with the actuator 7, each articulated to one of the two wheel carrier 3 and 3a tie rods 8 and 8a. The actuator 7 is fixed to the transverse profile 5 and drivingly connected directly to each of the two tie rods 8 and 8a. In particular, the actuator 7 is arranged centrally on the transverse profile 5. At each tie rod 8 and 8a engages a not shown, double-acting

Actuator 7 of the actuator.

The actuator 7 is fastened to the transverse profile 5 via two fastening units 9 and 9a. Each fastening unit 9 and 9a encloses a profile section of the transverse profile 5 and has a shape that corresponds to a shape of the

Profile section is adjusted. Between the respective fastening unit 9 and 9a on the one hand and the profile section on the other hand is an elastomeric

Damping element 10 is arranged. Each fastening unit 9 and 9a has a clamp 11 or 11a, which surrounds the profile section of the transverse profile 5. Fig. 2 shows a schematic sectional view of another

Embodiment of a steerable beam steering axle 1 according to the invention for a vehicle, not shown. This steerable twist beam axle 1 may be a particular embodiment of the steerable beam steering shaft shown in FIG.

The steerable torsion beam axle 1 comprises two spaced apart, not shown trailing arm, which are connected to a cross-section shown in cross section, serving as a cross member 5. The twistable cross-section 5 assumes the function of a roll stabilizer. The transverse profile 5 is formed by a partially inwardly along its longitudinal extent deformed tube and is at least partially formed in cross-section U-shaped.

In addition, the steerable torsion beam axle 1 includes a not shown

Wheel carriers of the twist beam axle 1 connected adjusting device 6 for

Swiveling the wheel carriers around one steering axle each. The adjusting device 6 comprises an actuator 7 and two with the actuator 7 operable, each articulated to one of the two wheel carrier connected tie rods 8a, of which a tie rod in Fig. 2 is covered by the actuator 7. The actuator 7 is attached to the transverse profile 5 and drivingly connected directly to each of the two tie rods 8a. In particular, the actuator 7 is arranged centrally on the transverse profile 5. At each tie rod 8a engages a not shown, double-acting actuator of the actuator 7 at.

The actuator 7 is fastened to the transverse profile 5 via two fastening units 9a, only one fastening unit 9a being shown in FIG. 2, while the other fastening unit in FIG. 2 is covered by the fastening unit 9a. Each fastening unit 9a encloses a profile section of the transverse profile 5 and has a shape which is adapted to a shape of the profile section. Between the respective fastening unit 9a on the one hand and the profile section on the other hand, an elastomeric damping element 10 is arranged. Each fastening unit 9a has a two-part clamp 11a, which the

Profile section of the transverse profile 5 encloses. Each clamp 11a includes a

Fastener 12 and a fastener 13. The fasteners 12 and 13 of each clamp 11a are connected by screw 22 together. The actuator 7 is connected via the screw 22 with the clamps 11 a.

Incidentally, the steerable torsion beam axle 1 may be formed in accordance with the embodiment shown in Fig. 1, so reference is made to avoid repetition of the above description to Fig. 1.

3 shows a schematic and perspective detailed representation of a further exemplary embodiment of a steerable torsion beam axle 1 according to the invention for a vehicle, not shown. This steerable twist beam axle 1 differs essentially from that shown in FIGS. 1 and 2

Embodiments that the actuator 7 of the adjusting device 6 is arranged in a different relative position to the transverse profile 5. Of the transverse profile 5, only a central, U-shaped deformed profile section is shown. The tie rods,

Trailing arm and wheel of the steerable beam axle 1 are not shown in Fig. 3.

The clamps 11 and 11a are made in two parts. Each clamp 11 or 11a comprises a fastening element 12 and a fastening element 13

Fasteners 12 and 13 of each clamp 11 and 11 a are over a

Screw 22 connected together. The actuator 7 is over the

Screw 22 connected to the clamps 11 and 11a.

Incidentally, the steerable torsion beam axle 1 may be formed in accordance with the embodiments shown in Figs. 1 and 2, so reference is made to avoid repetition of the above description to Fig. 1 and Fig. 2. 4 shows a schematic and perspective illustration of a further exemplary embodiment of a steerable torsion beam axle 1 according to the invention for a vehicle, not shown. This steerable twist beam axle 1 differs in particular by the configuration of the attachment of the actuator 7 on the transverse profile 5 of the embodiments shown in FIGS. 1 to 3.

The actuator 7 is fastened via two fastening elements 17 and 18 to the transverse profile 5. The fastening elements 17 and 18 are each fastened to the transverse profile 5 via two, for example common, screw connections 19. The

Fastening elements 17 and 18 are connected to each other via two arcuate portions 23, wherein the actuator 7 is held by the arcuate portions 23.

Otherwise, the torsion-beam axle 1 is designed in accordance with the exemplary embodiment shown in FIG. 1, for which reason reference is made here to FIG. 1 to avoid repetition in the above description.

Fig. 5 shows a schematic sectional view of another

Exemplary embodiment of a steerable torsion beam axle 1. This

Twist beam axle 1 may be a special embodiment of the steerable beam steering axle shown in FIG.

The actuator 7 is fastened via two fastening elements 17 and 18 to the transverse profile 5. The fasteners 17 and 18 are each over two

Screw 19 fixed to the cross profile 5, wherein in Fig. 5 only one screw 19 is shown, while other screw are arranged concealed. The fastening elements 17 and 18 are directly connected to the actuator 7. Furthermore, in FIG. 5, a track rod 8a connected directly to the actuator 7 can be seen.

The transverse profile 5 is V-shaped in cross-section and is arranged to open in the direction of the actuator 7. The transverse profile 5 comprises two legs 15 and 16, which are arranged at an angle to one another and are connected to one another at an angle. wherein the actuator 7 is fastened via a respective fastening element 17 or 18 to the legs 15 and 16 respectively. Each fastening element 17 or 18 is supported via an elastomeric damping element 21 on the respective leg 15 or 16, wherein the respective damping element 21 forms a bearing point.

Furthermore, the torsion-beam axle 1 comprises a V-shaped recess 20 of the transverse profile 5, which is arranged facing away from the actuator 7 and connected to the trailing arms, not shown

Stabilizing element 14. The stabilizing element 14 is tubular and integrally connected to the trailing arms.

Incidentally, the torsion beam axle 1 may be formed according to the embodiment shown in Fig. 4, which is why here to avoid

References to the above description to Fig. 4 is referenced.

6 shows a schematic and perspective detailed representation of a further exemplary embodiment of a steerable torsion beam axle 1 for a vehicle, not shown here. This torsion beam axle 1 corresponds to the insignificant differences in the embodiments of the actuator 7 to the embodiments shown in FIGS. 4 and 5. Of the cross-sectionally V-shaped cross-section 5 only a central profile section is shown. The tie rods, trailing arm and wheel carrier of the steerable beam axle 1 are not shown in Fig. 6. To avoid repetition, reference is made here to the above description of FIGS. 4 and 5.

Reference numeral steerable torsion beam axle

Trailing arm

a trailing arm

wheel carrier

a wheel carrier

steering axle

a steering axle

cross Section

setting device

actuator

tie rod

a tie rod

fixing unit

a fixing unit

0 damping element

1 clamp

1a clamp

2 fastener of 11, 11a 3 fastener of 11, 11a4 stabilizing element

5 thighs of 5

6 thighs of 5

7 fastening element

8 fastener

9 screw connection

0 recess of 5

1 damping element

2 screw connection

3 arcuate section

Claims

claims

1. Steerable torsion beam axle (1) for a vehicle, comprising two spaced-apart trailing arm (2, 2a), on each of which a wheel carrier (3, 3a) about a respective steering axis (4, 4a) is pivotally mounted, one of the two trailing arms (2, 2a) interconnecting, twistable transverse profile (5), and connected to the wheel carriers (3, 3a) adjusting means (6) for

Pivoting the wheel carrier (3, 3a) about the steering axles (4, 4a), wherein the

Adjusting device (6) has an actuator (7) and two respectively articulated to one of the two wheel carrier (3, 3a) connected to tie rods (8, 8a), and wherein the

Tie rods (8, 8a) by means of the actuator (7) are actuated, characterized

in that the actuator (7) is fastened exclusively to the transverse profile (5) and is directly connected to an end of each of the track rods (8, 8a) facing away from the respective wheel carrier (3, 3a).

2. Steerable torsion beam axle (1) according to claim 1, characterized in that the actuator (7) is arranged approximately, preferably exactly centered on the transverse profile (5).

3. Steerable torsion beam axle (1) according to claim 1 or 2, characterized in that a double-acting actuator of the actuator (7) on each of the tie rods (8, 8a) engages.

4. steerable torsion beam axle (1) according to one of claims 1 to 3, characterized in that the transverse profile (5) is preferably formed by a partially along its longitudinal extent inwardly formed tube and at least partially in cross-section U-shaped, wherein the Actuator (7) via at least one fastening unit (9, 9a) on the transverse profile (5) is fixed, which encloses a profile section of the transverse profile (5) and has a shape which is adapted to a shape of the profile section.

5. Steerable torsion beam axle (1) according to claim 4, characterized in that between the fastening unit (9, 9 a) and the profile section at least partially at least one elastic, preferably elastomeric, damping element (10) is arranged.

6. Steerable torsion beam axle (1) according to one of claims 1 to 3, characterized in that the transverse profile (5) is at least partially V-shaped in cross-section, in the direction of the actuator (7) is designed to be open and two angularly in cross-section having mutually arranged and interconnected legs (15, 16), wherein the actuator (7) via at least one

Fixing element (17, 18) on the legs (15, 16) is attached.

7. Steerable torsion beam axle (1) according to claim 6, characterized in that at least one fastening element (17, 18) at least partially via at least one elastic, preferably elastomeric, damping element (21) on the respective legs (15, 16) is supported.

8. Steerable torsion beam axle (1) according to claim 6 or 7, characterized by at least one at least partially within a the actuator (7) facing arranged, V-shaped recess (20) of the transverse profile (5) extending and with the trailing arms (2, 2a) connected

Stabilizing element (14).

9. Steerable torsion beam axle (1) according to claim 8, characterized in that the stabilizing element (14) is tubular.