DE102014018732A1 - Stabilizer for a chassis of a vehicle, in particular a motor vehicle - Google Patents

Abstract

The invention relates to a stabilizer (10) for a chassis of a vehicle, in particular of a motor vehicle, with a first stabilizer part (12) which can be connected to a first suspension of the running gear, with a second stabilizer part (14) which can be connected to a second wheel suspension of the chassis, with a hydraulic coupling device (18) having a plurality of working chambers (20a-d) which can be acted upon by a hydraulic medium, via which the stabilizer parts (12, 14) can be coupled to one another, and with a valve device (34) which is arranged between one of the working chambers (20a -D) fluidly separated blocking position and at least one the working chambers (20a-d) fluidly coupled to each other open position is adjustable, wherein at least one hydraulic pressure accumulator (38) is provided which is connected via at least one valve in such a way with the hydraulic coupling device (18) that even with temperature fluctuations and b ei in the open position valve device (34) there is a static base pressure in the hydraulic clutch device (18) prevails.

Description

The invention relates to a stabilizer for a chassis of a vehicle, in particular a motor vehicle, according to the preamble of claim 1.

Such a stabilizer for a chassis of a vehicle, especially a motor vehicle such as a passenger car, is already the DE 197 54 539 A1 to be known as known. The stabilizer comprises a first stabilizer part, which is connectable to a first suspension of the chassis. Furthermore, the stabilizer comprises a second stabilizer part, which is connectable to a second suspension of the chassis. The stabilizer further comprises a hydraulic coupling device, via which the stabilizer parts are coupled to one another. The coupling device has a plurality of working chambers, which can be acted upon by a hydraulic medium. By this is meant that the hydraulic medium can be introduced into the working chambers and discharged from the working chambers.

Furthermore, the stabilizer comprises a valve device, which is adjustable between a blocking position and at least one open position. In the blocking position, the working chambers are fluidically separated from each other. In the open position, however, the working chambers are fluidically coupled together. The stabilizer is thus a hydraulically lockable or switchable and unlockable or disengageable stabilizer, which is also referred to as Achsdrehstab, by means of the stabilizer in particular in the locked state against the unlocked state Wankbewegungen a structure, in particular the body of the vehicle can be kept low.

In the locked state, in fact, the wheel suspensions are coupled or more strongly coupled with respect to the unlocked state via the stabilizer, so that rolling movements can be kept at least low. In the unlocked state, the wheel suspensions are decoupled from each other or less strongly coupled to each other than in the locked state, so that a particularly high Wank Verschränkbarkeit the axles of the vehicle can be realized.

In the locked state, an increased roll stiffness is created by the stabilizer compared to the unlocked state, so that the roll-Verkschränkbarkeit the axes is hampered each other compared to the unlocked state by means of the stabilizer. In other words, the structure of the vehicle in the unlocked state can rock more than in the locked state. This is advantageous and desirable, for example, if the vehicle is moved on the ground, that is to say on a substrate with particularly severe unevenness. As a result of the entanglement of the axles, which is increased in the unlocked state compared with the locked state, ground contact of wheels of the vehicle can thus be ensured, so that the vehicle can also be moved off-road or driven over the wheels.

By adjusting the blocking position of the valve device, the hydraulic coupling device is locked or closed. By adjusting the open position, the hydraulic clutch device is opened, so that the stabilizer is ineffective or less effective than when the hydraulic clutch device is closed.

Object of the present invention is to improve a stabilizer of the type mentioned.

This object is achieved by a stabilizer having the features of patent claim 1. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

In order to improve a stabilizer specified in the preamble of claim 1 species, according to the invention at least one hydraulic accumulator for storing the hydraulic medium is provided, wherein the hydraulic accumulator is connected via at least one valve, in particular via pressure relief valves and check valves in such a way with the hydraulic coupling device, that even at Temperature fluctuations and in the open position located valve device, a static base pressure in the hydraulic clutch device prevails, the base pressure is substantially 20 bar. In other words, the hydraulic accumulator ensures a constant or at least substantially constant static pressure of 20 bar in the hydraulic coupling device even at changing temperatures and open valve device, so that, for example, in working chambers with negative pressure, the formation of vacuum bubbles can be prevented. Otherwise, unwanted cavitation noises could arise, for example when the valve is open - for example in a comfort straight-ahead driving or when driving off-road - as well as short-term fluctuations in the roll damping behavior of the vehicle since, when the valve device is open, a fundamentally advantageous increased roll damping results due to flow throttling in connection lines. in particular the opened hydraulic coupling device. These Cavitation noise and short-term fluctuations can now be avoided by using the hydraulic accumulator and the overpressure and check valves.

When the valve device is closed, a negative pressure with vacuum bubbles could be created by temperature-induced pressure drop in all working chambers or the effect of the hydraulic coupling device could be affected by gas bubbles, which outgas from the hydraulic medium. These problems can be avoided by the use of hydraulic accumulator and its coupling via the pressure and check valves.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawing shows in:

1 a schematic perspective view of a stabilizer for a chassis of a vehicle, with two stabilizer parts, which are coupled to each other via a hydraulic coupling device;

2 a schematic representation of the stabilizer according to a first embodiment; and

3 a schematic representation of the stabilizer according to a second embodiment.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

1 shows in a schematic perspective view of a stabilizer 10 for a chassis of a vehicle, in particular a motor vehicle and preferably a passenger car. As will be explained below, the stabilizer is 10 designed as a hydraulically lockable stabilizer. The stabilizer 10 comprises a first stabilizer part 12 , which is at least indirectly connectable to a first suspension of the landing gear. The first suspension is also referred to as the first axle suspension on which the stabilizer 10 over the first stabilizer part 12 at least indirectly fastened. The stabilizer 10 also includes a second stabilizer part 14 , which is at least indirectly connectable with a second suspension of the chassis. The second suspension is also referred to as the second axle suspension on which the stabilizer 10 over the second stabilizer part 14 at least indirectly fastened. Both suspensions are assigned to a common axle, so that the oppositely arranged wheel suspensions on the stabilizer 10 connectable to each other or can be coupled.

In 1 are also storage elements in the form of so-called stabilizer back bearings 16 recognizable over which the stabilizer 10 is pivotally mounted on a structure in the form of a body of the vehicle. This means that the stabilizer backbone 16 Swivel bearings are and for pivotal mounting or mounting of the stabilizer 10 to serve on the body. This allows the stabilizer parts 12 and 14 For example, rotate relative to the body about a rotation axis or pivot about respective pivot axes.

The stabilizer 10 moreover comprises a hydraulic coupling device 18 , which is also referred to as a hydraulic clutch. As will be explained in more detail below, the stabilizer parts 12 and 14 Coupled with each other via the hydraulic coupling. In synopsis with 2 and 3 It can be seen that the hydraulic clutch is designed as a swivel rotor system and in this case a plurality of working chambers 20a Having -d, which can be acted upon by a hydraulic medium or a hydraulic fluid. This is understood to mean the hydraulic medium in the working chambers 20a -D useable and out of the working chambers 20a -D is deductible.

2 shows a first embodiment of the stabilizer 10 , How out 2 is recognizable, comprises the hydraulic clutch (hydraulic clutch device 18 ) a housing 22 and a tilting rotor 24 which is in the housing 22 received and about a pivot axis relative to the housing 22 is pivotable. The housing 22 is for example with one of the stabilizer parts 12 and 14 rotatably coupled, wherein the swivel rotor 24 with the other of the stabilizer parts 12 and 14 rotatably coupled. From an inner circumferential side surface 26 of the housing 22 protrude wings 28 in the direction of the pivoting rotor 24 , where the wings 28 relative to the housing 22 are firm. Here are the wings 28 through the housing 22 formed and therefore integral with the housing 22 educated.

The swivel rotor 24 has more wings 30 on, which integral with the tilting rotor 24 formed and therefore about the pivot axis with the pivot rotor 24 with swivel. This means that the wings 30 relative to the wings 28 can be pivoted about the pivot axis. Furthermore, it is off 2 recognizable that the working chambers 20a -D through the housing 22 and the tilting rotor 24 especially through the wings 28 and 30 , are limited. Thus, respective volumes of the working chambers 20a -D by pivoting the pivot rotor 24 relative to the housing 22 variable. Will the swivel rotor 24 for example, based on the image plane of 2 clockwise relative to the housing 22 pivoted, so are the volumes of the working chambers 20b and 20c reduced, which with a respective increase in the volumes of the working chambers 20a -D goes along.

Will the swivel rotor 24 counterclockwise relative to the housing 22 pivoted, so are the working chambers 20a and 20d or their volumes reduced, and the working chambers 20b and 20c or their volumes are increased. Because the wings 28 relative to the housing 22 and the wings 30 relative to the swivel rotor 24 are fixed, the respective reduction of the respective volumes takes place to the same extent as the respective magnification of the respective volumes.

Out 2 It can also be seen that the stabilizer 10 a hydraulic switching device 32 comprising, which a valve device 34 having. In the first embodiment, the valve device comprises 34 exactly one switching valve 36 which is also called a check valve. In other words, the valve device 34 in the first embodiment by the switching valve 36 educated. In contrast, the valve device comprises 34 at an in 3 shown second embodiment, two switching valves 36 and 37 ,

The valve device 34 is between one of the working chambers 20a and 20d from the working chambers 20c and 20b separating blocking position and at least one of the working chambers 20a and 20d with the working chambers 20c and 20b fluidically coupling open position adjustable. In the blocking position is the hydraulic coupling device 18 closed, so the stabilizer 10 locked and thus activated or turned on. In the open position is the hydraulic coupling device 18 open, leaving the stabilizer 10 unlocked and thus deactivated or switched off. In the blocking position, namely the stabilizer parts 12 and 14 via the hydraulic coupling device 18 more strongly coupled together than in the open position, so that by means of acting as Achsdrehstab stabilizer 10 Rolling movements of the body can be suppressed or more suppressed in the locked position than in the open position.

The switching valve 36 respectively 37 is designed as an electric valve and thus as an electrically switchable valve, so that the respective switching valve 36 and 37 and thus the valve device 34 can be adjusted as needed between the open position and the locked position. In particular, it is possible in the second embodiment, the switching valves 36 and 37 independently adjustable between the respective open position of the respective blocking position, so that, for example, the switching valve 36 can be in the open position while the switching valve 37 in the locked position and vice versa.

Basically or technically conditioned, it can in the swivel rotor system, which is also referred to as swing-wing turntable, leaks in particular between the respective working chambers 20a Come so that preferably a high-viscosity hydraulic fluid is used as the hydraulic medium. This is particularly advantageous when the swivel rotor system is designed as a passive swing-wing turntable or as a passive swivel plate, otherwise the case of a long cornering of the vehicle by the stabilizer 10 provided stabilization to suppress wall movements of the body would decrease excessively.

Overall, the stabilizer allows 10 the presentation of a cost-effective and switchable stabilization with either high stabilization with closed valve device 34 that is, when it is in its locked position, or less strong stabilization when the valve device is open 34 That is, when this is in the open position. In the open position, the suspension can interlock particularly strong, so that the vehicle can be moved particularly advantageous in rough terrain. For comfort purposes, the valve device 34 be opened, for example, even when driving straight ahead of the vehicle.

Order now with open valve device 34 To avoid unwanted cavitation noise and short-term unwanted fluctuations, as well as with closed valve device 34 To prevent the formation of vacuum bubbles or gas bubbles in the hydraulic clutch, for example, designed as a gas storage hydraulic pressure accumulator 38 provided for storing the hydraulic medium, wherein the hydraulic pressure accumulator 38 via pressure relief valves 40 and 42 and check valves 44 and 46 with the hydraulic coupling device 18 so connected is that even with temperature fluctuations and in the open position located valve device 34 a static base pressure of at least substantially 20 bar prevails in the hydraulic clutch. The hydraulic switching device 32 includes, for example, the pressure relief valves 40 and 42 and the check valves 44 and 46 as well as the hydraulic pressure accumulator 38 , wherein the hydraulic switching device 32 over the hydraulic pressure accumulator 38 a pressure supply of the working chambers 20a -D with the hydraulic medium represents. The hydraulic switching device 32 with the pressure supply can be in the case 22 be integrated with the hydraulic clutch or have a separate housing which, for example, attached to the body and flexible hose lines in particular with the hydraulic coupling device 18 connected is.

In addition, the hydraulic switching device includes 32 Frequency-selective high-pass valves 48 and 50 , by means of which in the open position of the valve device 34 Movements of stabilizer parts 12 and 14 and thus rolling movements of the body are to be damped.

There are also the frequency-selective high-pass valves 48 and 50 Part of the hydraulic switching device 32 , When the valve device is open 34 If necessary, hydraulic damping ensures increased roll damping, in particular in conjunction with the frequency-selective high-pass valves 48 and 50 , which dampen high-frequency vibrations comfortable low only very low. The additional roll damping, which may be used in conjunction with the frequency-selective high-pass valves 48 and 50 is used. Thus, even when the hydraulic clutch is open, it allows a stable driving behavior during straight-ahead driving. This additional roll damping with open valve device 34 is present by throttle valves 52 and 54 the hydraulic switching device 32 realized.

It can be with open valve device 34 a particularly high driving comfort by means of the frequency-selective high-pass valves 48 and 50 realize whose flow resistance, for example, at increased excitation frequencies in the range of the wheel natural frequency by about 15 hertz (Hz) remains reduced, wherein in the region of the superstructure roll frequency of about 1 Hz, the respective, acting as a high-pass switching valve frequency-selective high-pass valve 48 and 50 locks and ensures a high low-frequency roll damping for the purpose of effective stabilization of the vehicle or the body despite unlocked stabilizer 10 , The longer-term locking of the stabilizer 10 , that is, the longer-term closure of the hydraulic clutch takes place for a correct driving behavior basically in the middle position of the hydraulic clutch device 18 and thus the stabilizer parts 12 and 14 , Advantageously, a sensor device is provided for this purpose, by means of which at least one rotation of the stabilizer parts 12 and 14 mutually characterizing measured variable can be detected.

In this case, the valve device 34 adjustable in dependence on the detected measured variable between the open position and the blocking position. The sensor device comprises, for example, at least one rotation sensor which, for example, on the housing 22 the hydraulic clutch is arranged. By means of such a rotation sensor, respective rotations of the stabilizer parts 12 and 14 be detected to each other. Alternatively or additionally, it is possible to associate the respective wheel suspension with at least one spring travel sensor. By means of such a spring travel sensor, a compression and rebound of the respective wheel can be detected. In other words, it can be detected by means of such a spring travel sensor how far or around which path the respective wheel is springing. Based on the respective Einfederzustands the respective wheel can then on the rotation of the stabilizer parts 12 and 14 be inferred to each other.

Is for example with twisted stabilizer 10 or with twisted stabilizer parts 12 and 14 , For example, for driving dynamics reasons, a locking of the stabilizer 10 and thus a closing of the hydraulic clutch required, thus the valve device 34 closed immediately in a twisted position. After decay of this immediate need, the valve device 34 open again and then closed on reaching the middle position then long term.

In the second embodiment with the two switching valves 36 and 37 the initial blocking as well as the subsequent center adjustment takes place by actuation of the switching valves 36 and 37 successively. In the first embodiment, the first blockage and the subsequent center adjustment takes place with a respective opening and closing of exactly one switching valve 36 ,

Further, it is possible, the hydraulic clutch when leaving the center position due to leaks, for example, long-term cornering, to readjust the center position - after exceeding an allowable turning limit - on a suitable short opening the valve device 34 to adjust again in the middle.

In other words, it can be provided in the second embodiment that in If necessary, the necessary for the immediate pressure build-up of the switching valves 36 and 37 immediately closes while the other of the switching valves 36 and 37 but still remains open and thus a reverse rotation of the stabilizer parts 12 and 14 allows up to the middle position, whereupon then the other switching valve 36 respectively 37 locked or closed.

This means that centering logic are provided, by means of which both after a ride with an open hydraulic clutch and after a long cornering and resulting adjustment of the stabilizer parts 12 and 14 to each other, the middle position of the stabilizer parts 12 and 14 is adjustable. Adjusting the stabilizer parts 12 and 14 during prolonged cornering occurs, for example, because of unavoidable internal leakage of rugged and multi-part swing-wing seals at long-lasting one-sided stabilizer moments, the hydraulic clutch from the middle position adjusted. These center-centering logics receive their center signal either from the mentioned rotation angle sensor, for example, on the housing 22 and in particular at the two mechanically always connected stabilizer parts striking each other in the hydraulic clutch 12 and 14 is arranged, or from the spring travel sensors, which are also referred to as Radwegsensoren.

The second embodiment is due to the two switching valves 36 and 37 more complicated than the first embodiment, however, allows the advantage of a clearer switching logic, so that the control electronics can be made simpler and fail-safe, which is particularly advantageous for each decentralized control electronics directly to each hydraulic coupling.

LIST OF REFERENCE NUMBERS

10

stabilizer

12

first stabilizer part

14

second stabilizer part

16

Stabilizer bearing backs

18

Hydraulic coupling device

20a-d

working chamber

22

casing

24

tiltrotor

26

Inner peripheral side surface

28

wing

30

wing

32

hydraulic switching device

34

valve means

36

switching valve

37

switching valve

38

Hydraulic accumulator

40

Pressure relief valve

42

Pressure relief valve

44

check valve

46

check valve

48

Frequency-selective high-pass valve

50

Frequency-selective high-pass valve

52

throttle valve

54

throttle valve

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19754539 A1 [0002]

Claims (8)

Stabilizer ( 10 ) for a chassis of a vehicle, in particular of a motor vehicle, with a first stabilizer part connectable to a first suspension of the chassis ( 12 ), with a connectable to a second suspension of the landing gear, second stabilizer part ( 14 ), with a plurality of pressurizable with a hydraulic medium working chambers ( 20a -D) having hydraulic coupling device ( 18 ) over which the stabilizer parts ( 12 . 14 ) are coupled together, and with a valve device ( 34 ), which between one of the working chambers ( 20a -D) fluidly separated blocking position and at least one of the working chambers ( 20a D) fluidically coupling open position is adjustable, characterized in that at least one hydraulic pressure accumulator ( 38 ) is provided, which via at least one valve ( 40 . 42 . 44 . 46 ) in such a way with the hydraulic coupling device ( 18 ), that even with temperature fluctuations and in the open position located valve device ( 34 ) a static basic pressure in the hydraulic coupling device ( 18 ) prevails. Stabilizer ( 10 ) according to claim 1, characterized in that at least one frequency-selective high-pass valve ( 48 . 50 ) is provided, by means of which in the open position of the valve device ( 34 ) Movements of at least one of the stabilizer parts ( 12 . 14 ) are to be damped. Stabilizer ( 10 ) according to claim 1 or 2, characterized in that a sensor device is provided, by means of which at least one rotation of the stabilizer parts ( 12 . 14 ) measurable to each other measured variable is detected. Stabilizer ( 10 ) according to claim 3, characterized in that the valve device ( 34 ) is adjustable in dependence on the detected measured variable between the open position and the blocking position. Stabilizer ( 10 ) according to claim 3, characterized in that the at least one valve ( 40 . 42 . 44 . 46 ) a pressure relief valve ( 40 . 42 ) and / or a check valve ( 44 . 46 ). Stabilizer ( 10 ) according to claim 3, characterized in that the static base pressure is at least 20 bar or substantially 20 bar. Method for operating a stabilizer ( 10 ) according to any one of the preceding claims. Vehicle, in particular motor vehicle, with at least one stabilizer ( 10 ) according to one of claims 1 to 4.

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