EP1474301A1

EP1474301A1 - Stabiliser bar for a motor vehicle

Info

Publication number: EP1474301A1
Application number: EP03704307A
Authority: EP
Inventors: Metin Ersoy; Jens Vortmeyer
Original assignee: ZF Lemfoerder GmbH
Current assignee: ZF Lemfoerder GmbH
Priority date: 2002-02-12
Filing date: 2003-02-11
Publication date: 2004-11-10
Also published as: CN1516650A; WO2003068541A1; US20040169346A1; JP2005517564A; KR20040080330A; DE10205932A1; US7121559B2

Abstract

The invention relates to a stabiliser bar (1') for a motor vehicle, comprising a one-piece torsion bar (5') which is rotatably fixed to a vehicle frame (3) and is connected to two opposing wheel suspensions (4') of the same axis of the vehicle. Said torsion bar comprises a torsion region for the flexible coupling of spring movements of the opposing wheel suspensions (4'). The inventive stabiliser bar (1') also comprises a first torsion tube (8') which surrounds the one-piece torsion bar (5') at least in a first part (B') of its torsion region. The first end (8a') of said torsion tube is connected to the one-piece torsion bar (5') in a rotationally fixed manner, and the second end (8b') of the torsion tube can be connected to the one-piece torsion bar (5') in a selectively rotationally fixed manner by means of a coupling system (9'), in such a way that the torsional rigidity of the stabiliser bar (1') can be modified.

Description

Anti-roll bar for a motor vehicle

description

The present invention relates to a transverse stabilizer for a motor vehicle according to the preamble of patent claim 1.

Transverse stabilizers for motor vehicles are usually used to elastically couple the wheel suspension of a wheel on one side of the motor vehicle to the wheel suspension of the corresponding wheel on the same axis on the other side of the motor vehicle. The coupling is such that when one wheel is deflected, the suspension of the other wheel is also acted on in the direction of spring deflection. As a result, when the motor vehicle is cornering, the lateral inclination of the motor vehicle toward the outside of the curve is reduced because, on the one hand, the wheel suspension of the wheel on the outside of the curve is additionally supported by the suspension of the wheel suspension of the wheel on the inside of the curve and, on the other hand, the wheel suspension of the wheel on the inside of the curve is pushed somewhat in the direction of deflection relative to the vehicle frame.

In contrast, when driving straight ahead, the anti-roll bar should as far as possible not influence the suspension behavior of the vehicle.

However, if the road surface is so uneven that a wheel on one side of the vehicle is pushed in the direction of deflection, while the corresponding wheel on the other side of the vehicle has to be moved in the direction of rebound to maintain the desired contact with the ground, the driving comfort is reduced by Cross stabilizer impaired. The anti-roll bar tends to counteract movements of the wheel suspensions coupled by the anti-roll bar relative to the vehicle body. Thus, a transverse stabilizer when driving straight ahead can undesirably result in vibrations of one wheel being transmitted to the opposite wheel on the same axle, which impairs driving comfort.

This contradiction between safety and comfort requirements for a cross stabilizer can be eliminated if the cross stabilizer is switched off when driving straight ahead and is automatically switched on again when cornering.

Such a system is known for example from DE-AS 11 05 290. DE-AS 11 05 290 describes providing a stabilizer with a split torsion bar, the sections being connected to one another in the manner of a hydraulic clutch which is controlled as a function of the centrifugal force or the vehicle steering. This makes it possible to disable the stabilizer when driving straight ahead by opening the clutch and to switch it on only when cornering. Moreover, it is also known from this document to adjust the sections of the torsion bar relative to one another by means of an actuating motor when cornering in such a way that the vehicle body tilts less far towards the outside of the curve, i.e. an inclination is actively counteracted.

A known actuator for coupling transverse stabilizers with a split torsion bar is known from DE 199 50 244 C2. Further actuators are described in DE 37 4024 C2.

A disadvantage of the known anti-roll bars with a split torsion bar is that the turning on (coupling) of the anti-roll bar must take place automatically and very quickly for safety reasons when cornering, since the vehicle could otherwise become uncontrollable when cornering. The high costs associated with these requirements for the actuator of the known cross stabilizers have led to the fact that switchable cross stabilizers (also under the name "active cross stabilizers" known) in volume models (ie vehicles that are manufactured in large quantities) are not used.

Furthermore, slow, in particular manually switchable, cross stabilizers are known, which are used in particular in the off-road sector. Such transverse stabilizers, for example known from DE 43 07 639 Cl, are only suitable for improving traction when driving slowly through the terrain. For safety reasons, systems of this type are not suitable for switching on or off the cross stabilizer when driving on a normal road, since there is a risk that the cross stabilizer will not be switched on in a curve or not in time, and the vehicle will thus become in an uncontrollable state.

It is an object of the present invention to provide an inexpensive anti-roll bar which is sufficiently effective when cornering and evasive maneuvers, and which only slightly impairs the suspension behavior of the vehicle to ensure a high level of driving comfort.

The object is achieved according to the main claim of the invention. The invention is developed in its subclaims.

According to the present invention, a transverse stabilizer for a motor vehicle is proposed which has an undivided torsion bar which is rotatably fastened to a vehicle frame and is connected to two opposite wheel suspensions of the same axis of the vehicle and which has a torsion region for the elastic coupling of suspension movements of the opposite wheel suspensions, the transverse stabilizer furthermore has a first torsion tube surrounding the undivided torsion bar, at least in a first partial area of its torsion area, the first end of which is non-rotatably connected to the undivided torsion bar, and the second end of which is selectively non-rotatably connected to the undivided by means of a coupling arrangement Torsion bar is connectable so that the torsional stiffness of the anti-roll bar can be changed.

Thus, according to the invention, there is no complete decoupling of the suspension movements of the opposite wheel suspensions, but only the torsional rigidity of the anti-roll bar is changed. It is therefore not necessary to design the coupling arrangement for the maximum torsional stiffness of the transverse stabilizer, but only for the torsional stiffness of the torsion tube, as a result of which the coupling arrangement can be made simpler and therefore cheaper. Even in the event of a complete failure of the clutch arrangement, a minimum amount of elastic coupling of the suspension movement of the opposing wheel suspensions is always guaranteed in the anti-roll bar according to the invention.

In a preferred embodiment, the undivided torsion bar has areas of different torsional stiffness, and the torsional stiffness of the undivided torsion bar is lower in a first section than in a second section.

This makes it possible to provide the torsion tube and the coupling arrangement of the anti-roll bar according to the invention specifically at a favorable installation location on the motor vehicle.

The torsional stiffness of the undivided torsion bar is preferably between 20 and 50 percent, and the torsional stiffness of the torsion tube between 80 and 50 percent of the torsional stiffness of the transverse stabilizer, if the second end of the torsion tube is connected to the undivided torsion bar in a rotationally fixed manner by means of the coupling arrangement.

In order to achieve the above-described task of the transverse stabilizer according to the invention as reliably as possible, the coupling arrangement is preferably suitable for turning the second end of the first torsion tube in a rotationally fixed manner with the torsion bar depending on the actual and / or expected transverse acceleration of the vehicle connect. It is thus possible to automatically disengage the anti-roll bar when the vehicle is driving straight ahead, and to re-engage it automatically when cornering.

According to an alternative embodiment, the anti-roll bar according to the invention also has a second torsion tube surrounding the torsion bar in a second partial area of its torsion area, the first end of which can be selectively connected in a rotationally fixed manner to the second end of the first torsion tube by means of the coupling arrangement and the second end of which is non-rotatably connected to the undivided torsion bar connected is.

In such a configuration of the transverse stabilizer according to the invention, the first torsion tube is not coupled directly to the undivided torsion bar, but rather to the second torsion tube. In particular, this enables a freer arrangement of the clutch arrangement on the motor vehicle.

In the alternative embodiment of the transverse stabilizer according to the invention, it is particularly advantageous if the torsional stiffness of the torsionally rigidly connected torsion tubes is between 80 and 50 percent of the torsional rigidity of the transverse stabilizer if the second end of the first torsional tube is connected to the first end of the second torsion tube in a rotationally fixed manner by means of the coupling arrangement ,

In the alternative embodiment as well, it is advantageous if the coupling arrangement is suitable for connecting the second end of the first torsion tube in a rotationally fixed manner to the first end of the second torsion tube depending on the actual and / or expected transverse acceleration of the vehicle. It is thus possible to automatically disengage the anti-roll bar when the vehicle is driving straight ahead, and to re-engage it automatically when cornering.

A coupling arrangement of a transverse stabilizer according to the alternative embodiment can be implemented particularly easily if the first end of the first torsion tube and / or the second end of the second torsion tube is mounted on the torsion bar so that it can rotate so that it can be axially displaced by the coupling arrangement. In order to avoid undesirable twisting of the torsion bar and / or the torsion tubes, it is advantageous if the first and / or the second torsion tube surrounds the undivided torsion bar centrally.

The clutch arrangement can preferably be controlled as a function of the driving speed and the steering angle and / or the steering angle speed and / or the lateral acceleration of the vehicle.

According to a preferred embodiment, the clutch arrangement has spring assemblies which are designed in such a way that a quick closing of the clutch arrangement is ensured. Thus, there is no need to apply energy to close the clutch assembly, making the system very fault tolerant.

In order to rule out a safety risk in the event of a possible malfunction, the coupling arrangement is preferably designed such that it closes or remains closed automatically in the event of a fault.

In general, the clutch arrangement can be switchable hydraulically or pneumatically, for example.

According to a preferred embodiment, the clutch arrangement has a hydraulic ring cylinder which is suitable for opening the clutch arrangement.

In order to ensure reliable coupling even under difficult conditions (e.g. twisted torsion bar when driving straight ahead as a result of potholes), the coupling arrangement is preferably designed such that an entanglement between the torsion bar and the torsion tube or the two torsion tubes that is permissible when the vehicle is traveling straight ahead cannot be exceeded ,

The permissible entanglement between the torsion bar and the torsion tube or the two torsion tubes can be limited particularly easily via end stops. According to a preferred embodiment, the clutch arrangement is designed in the form of a dog clutch.

The claw teeth of the claw coupling are then preferably designed such that an entanglement between the torsion bar and the torsion tube or the two torsion tubes that is permissible when the vehicle is traveling straight ahead cannot be exceeded when the clutch is open.

It is particularly advantageous if the claw teeth of the claw coupling are further configured such that the spring force of a spring which is suitable for closing the claw coupling is increased via the tooth flanks in order to reliably close the claw coupling even when the torsion bar and torsion tube are entangled or to ensure the two torsion tubes.

According to an alternative preferred embodiment, the coupling arrangement is designed in the form of a driving ball coupling, which has a first element and a second element, the elements being displaceable relative to one another, and pockets for driving balls being introduced into mutually facing sides of the elements, so that the driving balls are arranged between the first and the second element.

The pockets are preferably arranged on a circular ring and are designed in accordance with a rotational ellipsoid segment.

To ensure that the driver ball coupling can be securely closed even when there is an entanglement between the torsion bar and the torsion tube or the two torsion tubes, the pockets preferably have ramps which are designed in such a way that, when the driver ball coupling is open, an admissible entanglement between the torsion bar and the torsion tube or the two torsion tubes cannot be exceeded. The present invention is explained in more detail below with reference to figures. It shows

Figure 1 shows the schematic structure of a motor vehicle frame with anti-roll bars according to the invention;

Figure 2 is a cross-sectional view of the essential elements of the cross stabilizer according to the invention according to a first preferred embodiment;

Figure 3 is a cross-sectional view of the essential elements of the cross stabilizer according to the invention according to a second preferred embodiment;

Figure 4 is a plan view of an essential component of a driver ball coupling;

FIG. 5 shows a cross-sectional view through a closed driver ball coupling; and

Figure 6 is a cross-sectional view through an open driver ball coupling.

In the figures, the same elements are provided with the same reference symbols.

FIG. 1 shows how the transverse stabilizers 1, 1 'according to the invention can be arranged in a motor vehicle. In the exemplary embodiment shown, two different embodiments of the transverse stabilizer 1, 1 'according to the invention are arranged on the front axle 2 and the rear axle 2' of the vehicle. Alternatively, however, it is of course possible and possibly even sensible to arrange the same embodiment of the anti-roll bar according to the invention on the front and rear axles, or to arrange the anti-roll bar according to the invention on only one axis and a conventional anti-roll bar on the other axis. The transverse stabilizer 1, 1 'according to the invention each has an undivided torsion bar 5, 5' which is rotatably attached to a vehicle frame 3 and is connected to two opposite wheel suspensions 4, 4 'of the same axle 2, 2' of the vehicle. The torsion bar 5, 5 'has a torsion area for the elastic coupling of suspension movements of the wheel suspensions 4, 4' lying in pairs. The torsion area extends essentially between the two angled arms 7, 7 'of the respective torsion bar 5, 5'.

The torsion bar 5, 5 'is preferably mounted or articulated on the vehicle frame 3 or the wheel suspensions 4, 4' in such a way that it has to absorb little or no bending moment. The vehicle frame 3 is usually sprung against the wheel suspensions 4, 4 'via springs 6, 6'.

According to a first preferred embodiment of the present invention shown in FIG. 2, a transverse stabilizer, denoted overall by 1 ', has an undivided torsion bar 5' which is arranged in the transverse direction of the vehicle and is rotatably supported in bearings (not shown) fixed to the vehicle. Lever arms (not shown in FIG. 2) are attached to the ends of the undivided torsion bar 5 'facing away from one another. The free ends of the lever arms 7 'are each connected to the wheel suspension 4' (not shown in FIG. 2) of a wheel on the right or left side of the vehicle such that each lever arm 7 'during suspension strokes of the associated wheel about the axis of the undivided torsion bar 5 'swings. Thus, two opposing wheel suspensions of the same axis 2 'of the vehicle are elastically coupled via the torsion bar 5' having a torsion area.

The torsion bar 5 'has three partial areas A', B ', C of different torsional stiffness, the torsional rigidity in the partial areas A' and C in the embodiment shown being essentially the same, and the torsional rigidity in the partial area B 'less than in the partial areas A. 'and C is. The torsional stiffness is essentially constant within the individual regions A ', B' and C. Between the areas A 'and B' and B 'and C there are small transition areas D' and E 'in which the torsional rigidity of the torsion bar 5' is not constant. In the shown Embodiment, the individual areas are formed by appropriate tapering of the torsion bar 5 '.

Furthermore, the transverse stabilizer 1 'according to the invention has a torsion tube 8' which centrally surrounds the undivided torsion bar 5 'essentially in the partial area B' and the transition areas D 'and E' of its torsion area, the first end 8a 'of which is rotationally fixed, for example by welding, soldering or screwing is connected to the partial area C of the undivided torsion bar 5 ', and the second end 8b' thereof can be selectively and non-rotatably connected to the partial area A 'of the undivided torsion bar 5' by means of a coupling arrangement, generally referred to as 9 ', so that the torsional rigidity of the transverse stabilizer 1' as a whole is changeable.

In the embodiment shown in Figure 2, the torsional stiffness of the undivided torsion bar 5 'and the torsion tube 8' is chosen by suitable dimensioning and material selection of the torsion bar 5 'and the torsion tube 8' such that the torsional stiffness of the torsion bar 5 'is thirty percent and the torsional stiffness of the Torsion tube 8 'is seventy percent of the total torsional stiffness of the transverse stabilizer if the second end 8b' of the torsion tube 8 'is connected in a rotationally fixed manner to the partial region A of the undivided torsion bar 5' by means of the coupling arrangement 9 '.

In general, however, it is advantageous if the torsional rigidity of the torsion bar 5 'is between 20 and 50 percent, and the torsional rigidity of the torsion tube 8' is between 80 and 50 percent of the torsional rigidity of the transverse stabilizer 1 'when the second end 8b' of the torsion tube 8 'is by means of the clutch assembly 9 'is rotatably connected to the undivided torsion bar 5'.

The coupling arrangement 9 'is suitable for connecting the second end 8b' of the torsion tube 8 'in a rotationally fixed manner to the partial region A' of the torsion bar 5 'for the transmission of a torque, or of that, depending on the actual and / or expected lateral acceleration of the vehicle To separate section A 'of the torsion bar 5' so that the section A 'of the torsion bar 5' and the second end 8b 'of the torsion tube 8' can rotate independently. For this purpose, the coupling arrangement 9 'is preferably designed as a claw coupling as shown in FIG. 2 and has claw teeth (not specifically shown) which are designed such that an interlocking of the partial region A' of the torsion bar 5 'and the second end when the vehicle is traveling straight ahead 8b 'of the torsion tube 8' cannot be exceeded. Alternatively, such a restriction of the entanglement between the torsion bar and the torsion tube that is permissible when the vehicle is traveling straight ahead can also take place via end stops.

According to a further embodiment, not shown, the claw teeth of the claw coupling are further configured such that the spring force of a spring, which is suitable for closing the claw coupling, is increased via the tooth flanks in order to reliably close the claw coupling even when the torsion bar and torsion tube are entangled to ensure.

The claw coupling 9 'shown in FIG. 2 has an annular chamber 10' essentially formed by the torsion tube 8 'and the torsion bar 5', which is closed by an annular piston 12 'which can be displaced in longitudinal grooves 11'. The longitudinal grooves 11 'are introduced into the partial area A' of the torsion bar 5 '. Thus, the annular piston 12 'is not rotatable with respect to the torsion bar 5', but is axially displaceable and with respect to the second end 8b 'of the torsion tube 8' is arranged both rotatably and axially displaceably. To seal the annular chamber 10 'against the inner wall of the torsion tube 8' and the outer wall of the torsion bar 5 ', the annular piston 12' has seals 13 '.

Claws 14 ', 15', which can come into engagement with one another, are fastened to the displaceable annular piston 12 'and the second end 8b' of the torsion tube 8 ', for example by welding.

The annular chamber 10 'is connected via an inlet opening 16' to a pressure source, not shown, in order to act upon the annular chamber 10 'with a pressurized hydraulic or pneumatic medium. The pressure forces of the medium are chosen so that they the ring piston 12 'with the claws arranged thereon 14 'away from the claws 15' arranged at the second end 8b 'of the torsion tube 8', so that it is selectively possible to decouple the section A 'of the torsion bar 5' from the second end 8b 'of the torsion tube 8'. Usual ranges for the pressure force are 120 to 170 bar and preferably 150 bar.

In order to create a system which, in the event of a fault (for example in the event of failure of a hydraulic pump controlling the clutch arrangement 9 '), ensures that the clutch arrangement 9' closes safely and automatically, or keeps the clutch arrangement 9 'closed, the annular piston 12' is closed by springs 17 '. (preferably disc springs) in the closing direction of the clutch assembly 9 'and thus biased in the direction of the annular chamber 10'.

Thus, in the absence of a corresponding counterpressure of the medium in the annular chamber 10 ', the claws 14' arranged on the annular piston 12 'in a rotationally fixed manner come into engagement with the claws 15' arranged on the second end 8b 'of the torsion tube 8' in a rotationally fixed manner, so that the claws 14 'and 15' and thus also the subsection A 'of the torsion bar 5' and the second end 8b 'of the torsion tube 8' of the transverse stabilizer 1 'are coupled to one another in a force-locking manner.

Consequently, the torsional stiffness of the transverse stabilizer 1 'according to the invention in the coupled state results in this embodiment as the sum of the torsional stiffnesses of the torsion bar 5' and the torsion tube 8 '.

When a corresponding pressure force of the medium in the annular chamber 10 'occurs, the above-mentioned non-positive connection is interrupted, so that the torsional stiffness of the transverse stabilizer 1' according to the invention in the uncoupled state results only as the torsional stiffness of the torsion bar 5 '.

Instead of the annular chamber 10 'and the annular piston 12', a plurality of chambers with a circular cross section or the like can also be arranged for a correspondingly large number of individual pistons, which are actuated simultaneously. FIG. 3 shows the essential elements of a second preferred embodiment of the transverse stabilizer 1 according to the invention.

The second embodiment shown in FIG. 3 differs in principle from the first embodiment shown in FIG. 2 in that, according to the second embodiment, the torsional stiffness of the undivided torsion bar 5 of the transverse stabilizer 1 according to the invention is essentially constant over its entire torsion range, and in that the transverse stabilizer 1 according to the invention has two torsion tubes 81, 82 surrounding the undivided torsion bar 5 in two adjacent partial areas F, G of its torsion area, the ends of the torsion tubes 81, 82 facing away from one another being connected in a rotationally fixed manner to opposite areas of the undivided torsion bar 5, and the mutually facing ends of the torsion bars 81, 82 can be selectively connected in a rotationally fixed manner by means of a coupling arrangement 9.

For this purpose, the ends of the first and second torsion tubes 81, 82 are mounted on the torsion bar 5 so that they rotate in a manner fixed against relative rotation so that they can be axially displaced. Such an axially displaceable mounting is not absolutely necessary, but can be advantageous under certain conditions. Since the bearings 91, 92 of the opposite ends of the first and second torsion tubes 81, 82 correspond to one another in accordance with the second embodiment, only the bearing 91 of the first end 81a of the first torsion tube 81 is shown in FIG.

The first end 81a of the first torsion tube 81 is connected in a rotationally fixed manner to a sliding element 191 with its first end 81a facing away from the second torsion tube 82. The sliding element 191 is in engagement with longitudinal grooves 111, which are introduced into the torsion bar 5, and is thus rotatably displaceable in the longitudinal direction of the torsion bar 5. For sealing against the torsion bar 5, the sliding element 191 has a seal 131. The first torsion tube 81 is prestressed in the direction of the second torsion tube 82 via the sliding element 191 by means of a spring arrangement 171, which preferably has disc springs. The mutually facing ends 81b, 82a of the torsion tubes 81, 82 are displaceably arranged in a pressure-resistant sleeve 18 such that an annular chamber 10 is formed by the first and second torsion tubes 81, 82, each closed with a sliding element 191, the torsion bar 5 and the sleeve 18 becomes. To seal the annular chamber 10 against the outer walls of the first and second torsion tubes 81, 82, the sleeve 18 has seals 132.

Furthermore, claws 151, 152, which can come into engagement with one another, are each fixed in a rotationally fixed manner to the mutually facing ends 81b, 82a of the torsion tubes 81, 82.

The annular chamber 10 is connected via an inlet opening 16 to a pressure source, not shown, in order to act upon the annular chamber 10 with a pressurized hydraulic or pneumatic medium. The pressure forces of the medium are suitable for pushing apart the first and the second torsion tubes 81, 82 with the claws 151, 152 arranged thereon on request, so that it is possible to decouple the first torsion tube 81 from the second torsion tube 82.

Consequently, the torsional rigidity of the transverse stabilizer 1 according to the invention in the coupled state results in the sum of the torsional rigidity of the torsion bar 5 and the first and second torsion tubes 81, 82. It is particularly advantageous if the torsional rigidity of the torsionally connected torsion tubes 81, 82 contributes between 80 and 50 percent to the torsional stiffness of the anti-roll bar.

In the uncoupled state, however, the torsional rigidity of the transverse stabilizer 1 according to the invention is based only on the torsional rigidity of the undivided torsion bar 5.

In the embodiments described above, the clutch arrangement 9, 9 'is preferably controlled hydraulically by means of a computer-controlled actuating unit (not shown). Of course, the control can also be done pneumatically or via a servomotor. The actuating unit has a motor, for example a pump driven by an electric motor, the suction side of which is connected to a reservoir for a hydraulic medium and the pressure side of which is connected via a pressure line to a pressure accumulator and via a pressure relief valve to the reservoir and via a control valve to the clutch arrangement 9, 9 ' are connectable.

If, for example, the control valve designed as a slide valve is actuated in the sense of an opening of the clutch arrangement 9, 9 ', the pressure line is connected to the inlet opening 16, 16' of the clutch arrangement 9, 9 '. H. the clutch arrangement 9, 9 'is acted upon by the pressure of the pump and is accordingly opened or kept open.

If the control valve is switched to its other position, the connection between the pressure line and the inlet opening 16, 16 'of the coupling arrangement 9, 9' is blocked and at the same time a connection is established between the inlet opening 16, 16 'and the reservoir. Accordingly, the clutch assembly 9, 9 'is relieved of the hydraulic pressure, and the clutch assembly 9, 9' is closed and kept closed by the spring force of the springs 171, 17 '.

The control valve is preferably controlled by means of a computer, also not shown, which has sensors on the input side for the respective steering angle and the respective driving speed and / or possibly with further transmitters for additional data, for example data for the steering angle speed, the lateral acceleration of the vehicle, properties of the tires or the state of loading of the vehicle is connected. From the data obtained, the computer can calculate the actual and / or an expected value of the lateral acceleration of the vehicle.

As soon as the actual or expected lateral acceleration exceeds a predefinable threshold value, the control valve is activated to lock the clutch arrangement 9, 9 '. Thus, according to the first embodiment described above, the section A 'of the torsion bar 5' with the second end 8b 'of the torsion tube 8', or according to the second embodiment described above, the second end 81b of the first torsion tube 81 is coupled to one another with the first end 82a of the second torsion tube 82, so that the torsional rigidity of the transverse stabilizer 1, 1 'according to the invention is maximally effective, and a different insertion or Suspension of the opposing wheel suspensions 4, 4 'connected to it and of the vehicle wheels of the same axle 2, 2' of the vehicle counteracts with maximum elasticity.

When driving straight ahead or when the computer determines low or negligible values for the lateral acceleration of the vehicle, the control valve is actuated to open the clutch arrangement, so that, according to the first embodiment described above, the section A 'of the torsion bar 5' and the second end 8b 'of the Torsion tube 8 ', or according to the second embodiment described above, the second end 81b of the first torsion tube 81 and the first end 82a of the second torsion tube 82 are decoupled from one another, and the transverse stabilizer 1, 1' according to the invention for these values of the lateral acceleration of the vehicle only in The torsional stiffness of the respective undivided torsion bar 5, 5 'is effective, so that it only elastically counteracts a relative movement of the wheel suspensions 4, 4' of the vehicle wheels of the same axle 2, 2 '.

A further particularly preferred embodiment of the clutch arrangement 9, 9 'is described below with reference to FIGS. 4, 5 and 6.

According to this particularly preferred embodiment, the coupling arrangement 9; 9 'in the form of a driver ball coupling. The driver ball coupling has a first and a second element 51, 52, the elements 51, 52 being displaceable relative to one another, and pockets 531, 532 for driver balls 54 being introduced into mutually facing sides of the elements 51, 52.

An element 51 with pockets 531 and driver balls 54 is shown in a top view in FIG. 4. The second element 52, not shown in FIG. 4, preferably has the same structure as the first element 51. As shown in Fig. 4, the pockets are 531 are preferably arranged on a circular ring and have an essentially elliptical circumferential line.

As can be seen from FIGS. 5 and 6, the first element 51 and the second element 52 are arranged such that the driver balls 54 are arranged between the first element 51 and the second element 52.

As can further be seen from FIGS. 5 and 6, the pockets 531 and 532 are each designed in accordance with the shape of a rotational ellipsoid segment and have ramps with respect to the mutually facing side surfaces of the two elements 51, 52 which form an angle α, γ include the side faces of members 51 and 52. In this preferred embodiment, the ramps are designed by a suitable choice of the angles α, γ in such a way that, when the coupling is open, a permissible entanglement of preferably 7 to 10 ° between the torsion bar 5 'and the torsion tube 8' or the two torsion tubes 81, 82 is not exceeded can. For this, the angles are α; γ between 55 ° and 65 °, and preferably 60 °.

It is particularly advantageous about the driver ball coupling described above that, in the opened state, it allows a precisely definable restriction between the torsion bar 5 'and the torsion tube 8' or the two torsion tubes 81, 82, and, as is clear from FIG. 6, for example can be reliably closed in the entangled state.

Thus, according to the present invention, an inexpensive anti-roll bar is proposed, which is sufficiently effective when cornering and evasive maneuvers, and otherwise only slightly affects the suspension behavior of the vehicle, so that a high level of driving comfort is ensured. LIST OF REFERENCE NUMBERS

1, 1 'anti-roll bar

2, 2 'axis

3 vehicle frames

4, 4 'wheel suspension

5, 5 'torsion bar

A ', B', C partial areas of the torsion bar 5 '

F, G sections of the torsion bar 5

6, 6 'spring

7, 7 'arm

8 'torsion tube

8a 'first end of the torsion tube 8'

8b 'second end of the torsion tube 8'

9, 9 'clutch assembly

10, 10 'ring chamber

11 'longitudinal groove

12 'ring piston

13 'seal

14 'Claw

15 'claw

16, 16 'inlet opening

17 'spring

18 sleeve

81, 82 torsion tube

81a end of the torsion tube 81

81b end of the torsion tube 81

82a end of the torsion tube 82

91, 92 storage 111 longitudinal groove

131,132 seal

151.152 claw

171 spring arrangement

191 sliding element

51.52 element

531,532 bag

54 Driving ball α, γ angle

Claims

Transverse stabilizer for a motor vehicle patent claims

Transverse stabilizer (1; 1 ') for a motor vehicle, comprising an undivided torsion bar (5; 5) which is rotatably attached to a vehicle frame (3) and is connected to two opposite wheel suspensions (4; 4') of the same axis (2; 2 ') of the vehicle '), which has a torsion area for the elastic coupling of suspension movements of the opposite wheel suspensions (4; 4'), characterized in that the transverse stabilizer (1; 1 ') furthermore an undivided torsion bar (5; 5') at least in a first partial area (F; B ') of its torsion area surrounding first torsion tube (81; 8'), the first end (81a; 8a ') of which is connected in a rotationally fixed manner to the undivided torsion bar (5; 5'), and the second end (81b; 8b ') can be selectively and non-rotatably connected to the undivided torsion bar (5; 5') by means of a coupling arrangement (9; 9 '), so that the torsional stiffness of the transverse stabilizer (1; 1') can be changed.

Transverse stabilizer (1 ') according to claim 1, characterized in that the undivided torsion bar (5') has areas (A ', B', C) of different torsional stiffness and the torsional stiffness of the undivided torsion bar (5 ') in a first partial area (B' ) is less than in a second partial area (A ', C).

3. transverse stabilizer (1 ') according to claim 1 or 2, characterized in that the torsional rigidity of the undivided torsion bar (5') between 20 and 50 percent, and the torsional rigidity of the torsion tube (8 ') between 80 and 50 percent of the torsional rigidity of the transverse stabilizer (1 ') is when the second end (8b') of the torsion tube (8 ') is non-rotatably connected to the undivided torsion bar (5') by means of the coupling arrangement (9 ').

4. anti-roll bar (1 ') according to any one of the preceding claims, characterized in that the coupling arrangement (9') is suitable for the second end (8b ') of the first torsion tube (8') depending on the actual and / or expected Connect the lateral acceleration of the vehicle to the torsion bar (5 ') so that it cannot rotate.

5. transverse stabilizer (1) according to one of the preceding claims, characterized in that the transverse stabilizer (1) further comprises a torsion bar (5) in a second partial area (G) of its torsion area surrounding second torsion tube (82), the first end (82a ) can be selectively and non-rotatably connected to the second end (81b) of the first torsion tube (81) by means of the coupling arrangement (9), and the second end of which is non-rotatably connected to the undivided torsion bar (5).

6. The transverse stabilizer (1) according to claim 5, characterized in that the torsional rigidity of the torsionally connected torsion tubes (81, 82) is between 80 and 50 percent of the torsional rigidity of the transverse stabilizer (1) when the second end (81b) of the first torsion tube ( 81) is connected in a rotationally fixed manner to the first end (82a) of the second torsion tube (82) by means of the coupling arrangement (9).

7. Transverse stabilizer (1) according to one of claims 5 or 6, characterized in that the coupling arrangement (9) is suitable for the second end (81b) of the first torsion tube (81) as a function of the actual and / or expected transverse acceleration of the To connect the vehicle in a rotationally fixed manner to the first end (82a) of the second torsion tube (82).

8. transverse stabilizer (1) according to any one of the preceding claims, characterized in that the first end (81a) of the first torsion tube (81) and / or the second end of the second torsion tube (82) is rotatably mounted on the torsion bar (5) that it is axially displaceable through the coupling arrangement (9).

9. transverse stabilizer (1; 1 ') according to any one of the preceding claims, characterized in that the first and / or the second torsion tube (81, 82; 8') surrounds the undivided torsion bar (5; 5 ') centrally.

10. anti-roll bar (1; 1 ') according to any one of the preceding claims, characterized in that the clutch arrangement (9; 9') is controllable in dependence on the driving speed and the steering angle and / or the steering angle speed and / or the lateral acceleration of the vehicle.

11. The anti-roll bar (1; 1 ') according to one of the preceding claims, characterized in that the clutch arrangement (9; 9') has spring assemblies (171; 17 ') which are designed so that the clutch arrangement (9; 9 ') is guaranteed.

12. anti-roll bar (1; 1 ') according to any one of the preceding claims, characterized in that the coupling arrangement (9; 9') is designed so that it automatically closes or remains closed in the event of a fault.

13. Transverse stabilizer (1; 1 ') according to one of the preceding claims, characterized in that the coupling arrangement (9; 9') can be switched hydraulically or pneumatically.

14. Transverse stabilizer (1; 1 ') according to claim 13, characterized in that the coupling arrangement (9; 9') has a hydraulic ring cylinder (10; 10 ') which is suitable for opening the coupling arrangement (9; 9').

15. Transverse stabilizer (1; 1 ') according to one of the preceding claims, characterized in that the coupling arrangement (9; 9') is designed such that an entanglement between the torsion bar (5 ') and the torsion tube (8') permitted when the vehicle is traveling straight ahead. ) or the two torsion tubes (81, 82) cannot be exceeded.

16. Cross stabilizer (1; 1 ') according to claim 15, characterized in that the limitation of the permissible entanglement between the torsion bar (5') and the torsion tube (8 ') or the two torsion tubes (81, 82) takes place via end stops.

17. anti-roll bar (1; 1 ') according to any one of the preceding claims, characterized in that the coupling arrangement (9; 9') is designed in the form of a dog clutch.

18. Anti-roll bar (1; 1 ') according to claim 17, characterized in that the claw teeth of the claw coupling are designed such that a permissible entanglement between the torsion bar (5') and the torsion tube (8 ') or the two torsion tubes when the vehicle is traveling straight ahead (81, 82) cannot be exceeded.

19. The transverse stabilizer according to one of claims 17 or 18, characterized in that the claw teeth of the claw coupling are designed such that the spring force of a spring (171; 17 ') which is suitable for closing the claw coupling is increased via the tooth flanks, in order to ensure reliable closing of the claw coupling even in the case of an entanglement between the torsion bar (5 ') and the torsion tube (8') or the two torsion tubes (81, 82).

20. Transverse stabilizer (1; 1 ') according to any one of claims 1 to 16, characterized in that the coupling arrangement (9; 9') is designed in the form of a driver ball coupling which has a first element (51) and a second element ( 52), the elements (51, 52) being displaceable relative to one another, and pockets (531, 532) for driving balls (54) being introduced into mutually facing sides of the elements (51, 52), so that the driving balls (54) between the first and the second element (51, 52) are arranged.

21. Transverse stabilizer (1; 1 ') according to claim 20, characterized in that the pockets (531, 532) are arranged on a circular ring.

22. Transverse stabilizer according to one of claims 20 or 21, characterized in that the pockets (531, 532) are designed in accordance with a rotational ellipsoid segment.

3. Anti-roll bar according to one of claims 20, 21 or 22, characterized in that the pockets (531, 532) have ramps which are designed such that, when the driver ball coupling is open, a permissible entanglement between the torsion bar (5 ') and the torsion tube ( 8 ') or the two torsion tubes (81, 82) cannot be exceeded.