DE102010021029A1 - Compensation element for hydraulic roll stabilizer system for axles of motor car, has two active spaces separated from each other via piston, where piston comprises spring loaded piston rods extending opposite from housing - Google Patents

Abstract

The element (44) has two active spaces (32, 38) arranged in a common housing and separated from each other via a piston (46). The piston comprises spring loaded piston rods (48, 50) extending opposite from the housing. The piston rods are designed as hollow bars, which are arranged with a transverse bore in a region of the piston. A valve is introduced between the two active spaces. An axial thrust bearing is arranged between spring elements (34, 40) and a spring seat (56). The spring element is formed from a metal, a gas and a rubber. An independent claim is also included for a hydraulic roll stabilizer system for axles of a motor, comprising landing gear vibration dampers.

Description

The invention relates to a compensating element for a hydraulic roll stabilizer system of a motor vehicle according to the type specified in the preamble of claim 1 and a hydraulic roll stabilizer system according to the specified in the preamble of claim 8 Art.

Hydraulic Wankstabilisatorsysteme for motor vehicles are well known and, for example in the DE 195 105 33 and DE 197 190 29 disclosed.

In this case, an axis between the motor vehicle body and the wheel suspension element arranged cylinder-piston unit is assigned to the opposite wheels, the working chambers are each cross-connected with the interposition of a spring-loaded active space. By the crosswise connection of the respective working chambers of the two cylinder-piston units, a stabilization of the vehicle can be generated in the event of a roll. In Wankfall a spring-loaded active space is filled with hydraulic fluid and the spring element is compressed. This increases the pressure in this hydraulic circuit. The second active space springs out (negative spring travel) and promotes its hydraulic volume in the working chambers of the cylinder-piston units, the pressure in this hydraulic circuit decreases. Because of the different pressure levels in the working chambers of the cylinder-piston units, a path-dependent stabilizing force is generated, which counteracts the compression travel. In a bilateral compression movement, however, the stabilizer is without function. The hydraulic volumes are only pushed from one cylinder-piston unit to the other, without activating the spring-loaded Wirkräume.

The disadvantage here is that according to the prior art two spring-loaded Wirkräume be needed. This has an increased number of components, a large space required and increased friction, due to the use of two pistons result. Precisely because of the high static friction and the resulting poor response (slip stick effect) hydraulic cheek stabilizer systems are only used to a very limited extent. Another disadvantage with the use of two spring-loaded Wirkräumen is that the springs are to be biased in two compensating elements. Only then can the required negative spring travel be generated in the event of a roll. By biasing the springs, a hydraulic bias pressure is generated in both hydraulic circuits, which also increases the system friction due to the greater pressure on the hydraulic seals.

The invention has for its object to provide a compensating element for a hydraulic roll stabilizer system of a motor vehicle according to the type specified in the preamble of claim 1 available, which has a more compact design and lower static friction.

This object is solved by the characterizing features of claim 1 in conjunction with its preamble features.

The dependent claims 2 to 7 form advantageous developments of the invention.

Furthermore, the invention has the object of providing a hydraulic Wankstabilisatorsystem for a motor vehicle according to the specified in the preamble of claim 8 way such that a friction-optimized operation of the hydraulic Wankstabilisatorsystems is possible.

This object is achieved by the characterizing features of claim 8 in conjunction with its preamble features.

The subclaims 9 and 10 form advantageous developments of the invention.

In the compensating element for a hydraulic roll stabilizer system of a motor vehicle according to the invention the two Wirkräume are arranged in a common housing and separated by a piston guided in the housing, wherein the piston guided in the housing in turn has two opposite, projecting out of the housing spring-loaded piston rods.

The inventive integration of the two Wirkräume in a common housing, is now ensured in an advantageous manner that the required space is smaller and a smaller number of components is required. In addition, since only one piston is required in the compensation element according to the invention, the static friction is also significantly reduced in an advantageous manner.

Preferably, the piston rods are formed as a hollow body with a transverse bore arranged in the region of the piston. As a result, an inflow or outflow of hydraulic fluid via the piston rod is made possible in an advantageous manner. Ie. another u. U. again additional space consuming hydraulic connection is not required.

According to a particularly advantageous embodiment of the invention, a valve is introduced between the two Wirkräumen. The valve can z. B. in which the two Wirkräume separating Be introduced piston. It is also conceivable that the valve is arranged outside of the compensation element and the two, the Wirkräume crosswise interconnecting hydraulic lines together. The additional attachment of the valve, the two Wirkräume and thus the hydraulic circuits connected to each other and thus the stabilizer function are temporarily switched off. This can be used advantageously for off-road use, if large axle misalignments are needed without a stabilizer, or for active chassis control. Thus, when driving straight ahead by opening the valve, the stabilizer function can be switched off and a softer body suspension as well as less copying of the road bumps can be achieved. At the beginning of cornering, this valve can be closed again and the stabilizer can be reactivated.

According to a further advantageous embodiment of the invention, in each case a throttle valve is arranged in the entrance to the two Wirkräumen. Advantageously, a roll damping of the system is realized by the integration of the throttle valve.

To realize the required spring preload of the piston rod, a spring plate is disposed according to an embodiment respectively at the reaching out of the housing end of the piston rod and the housing is formed a corresponding spring support, wherein in each case between spring plate and spring support a coil spring is arranged. This embodiment proves advantageous because of its constructive simplicity.

Preferably, a thrust bearing is arranged between spring plate and coil spring or between coil spring and spring support. This ensures in an advantageous manner that during compression of the spring whose associated rotation can be done with the least possible resistance, that is, that the spring friction is reduced.

It is also conceivable that instead of the coil spring another spring element, for. B. gas or elastomeric spring is used.

The invention further relates to a hydraulic roll stabilizer system for an axle of a motor vehicle, comprising a first and second cylinder-piston unit, each associated with a wheel of the axle, arranged between the motor vehicle body and a wheel suspension element, whose working chambers are cross-connected to one another via hydraulic lines. According to the invention, the hydraulic lines are interconnected crosswise with the interposition of a single compensating element. The use of a single compensating element proves to be particularly advantageous, since in this way space and static friction are significantly reduced in the manner already described. Another advantage is that despite a bias of the springs to achieve the required negative spring travel no unnecessarily high biasing pressure is generated in the two hydraulic circuits, since the biasing forces of the springs on the piston cancel each other and so the frictional forces on the seals are additionally reduced.

Preferably, a control / regulating unit is provided, via which the valve in the piston or the throttle valves of the compensating element can be actively activated. By actively controlling the valve in the piston, it is possible to use this also for driving dynamics control. Controlled switching on and off of the stabilizers on the front and rear axles and the resulting wheel load shifting can influence the self-steering behavior of the vehicle. The function of the Electronic Stability Program (ESP) can thus be further extended and improved. By actively controlling the throttle valves, a desired roll damping can be realized in an advantageous manner as a function of the driving situation.

According to a further advantageous embodiment, the suspension vibration dampers are used as a cylinder-piston unit, each working chamber in its hydraulic line, a damping throttle and a parallel thereto, the outflow from the respective working chamber blocking check valve is assigned. By using the suspension vibration dampers as cylinder-piston units further components can be saved in an advantageous manner.

By these measures, the suspension vibration damper can be used as a cylinder-piston unit, that is, more components can be saved.

Further advantages, features and applications of the present invention will become apparent from the following description taken in conjunction with the embodiments illustrated in the drawings.

The invention will be described below with reference to the embodiments illustrated in the drawings.

In the description, in the claims, in the abstract and in the drawing, the terms and associated reference numerals used in the list of reference numerals below are used.

In the drawing:

1 A schematic representation of a hydraulic roll stabilizer system according to the prior art;

2 a schematic representation of a hydraulic roll stabilizer system using a compensation element according to the invention;

3 the hydraulic roll stabilizer system 2 with an optimized compensation element with additional valve in the piston head;

4 the hydraulic roll and stabilizer system 2 with an optimized compensation element with integrated anti-roll valves, and

5 a schematic representation of a hydraulic roll stabilizer system using the chassis vibration damper as cylinder-piston units.

In the following description and in the figures, to avoid repetition, the same components and components are identified by the same reference numerals, unless further differentiation is necessary or expedient.

1 shows a schematic representation of a total with the reference numerals 10 designated hydraulic roll stabilizer system for an axle of a motor vehicle according to the prior art.

The roll stabilizer system 10 includes a first and a second cylinder piston unit 12 . 14 , The first and second cylinder-piston unit are each associated with a wheel of the axle and arranged in a known manner each between a motor vehicle body and a suspension element. On a representation of the axis, the wheels of the axle, the motor vehicle body and the suspension elements has been omitted here for reasons of clarity.

The first cylinder-piston unit 12 has a first working chamber 16 , a second working chamber 18 and one, the two working chamber 18 . 20 separating, guided in the cylinder-piston unit pistons 20 on. Accordingly, the second cylinder-piston unit also has 14 a first working chamber 22 , a second working chamber 24 and a piston 26 on.

The working chambers 16 . 18 . 22 . 24 are by means of hydraulic lines 28 . 30 crosswise connected. That is, the first working chamber 16 the first cylinder-piston unit 12 is over the hydraulic line 28 with the second working chamber 24 the second cylinder-piston unit 14 connected and the second working chamber 18 the first cylinder-piston unit 12 is via hydraulic line 30 with the first working chamber 22 the second cylinder-piston unit 14 connected is.

In order to generate the required pressures to stabilize the vehicle, the first hydraulic line 28 first effective space 32 with a means of a spring element 34 preloaded piston 36 , as well as the second hydraulic line 30 a second effective space 38 with a means of a spring element 40 preloaded piston 42 assigned.

Due to the two pistons 36 . 42 The system according to the prior art has a relatively high degree of friction. In particular, due to the high static friction and the resulting poor response (slip stick effect) hydraulic Wankstabilisatorsysteme are still used only conditionally. Another disadvantage is that the two spring elements 34 . 40 be biased, as only so the required negative travel can be generated in the event of a roll. By the necessary biasing of the spring elements 34 . 40 will be in both hydraulic lines 28 . 30 generates a hydraulic biasing pressure, which also increases the system friction due to the greater pressure on the hydraulic seals.

How out 2 it can be seen now to avoid the above-mentioned disadvantages only as a compensation element 44 designated component provided via which the working chambers 16 . 24 respectively. 18 . 22 by means of hydraulic lines 28 respectively. 30 are interconnected crosswise.

In the compensation element 44 are the two Wirkräume 36 . 38 over a piston 46 separated. The piston 46 in turn has two opposite, out of the housing of the compensation element 44 reaching out piston rods 48 . 50 on. At the ends of the piston rods 48 . 50 each is a spring plate 52 . 54 mounted on the one spring element 34 . 40 rests. The other ends of the spring elements 34 . 40 lie directly on one on the housing of the compensation element 44 trained spring pad 56 on.

As the compensation element according to the invention 44 now only one piston 46 has significantly reduced friction. Another advantage is that, despite the bias of the two spring elements 34 . 40 to achieve the required negative spring travel in the two hydraulic lines 28 . 30 no additional unnecessary biasing pressure in addition to the usual in the shock absorbers Standard pressures is generated because the biasing forces of the spring elements on the piston 46 cancel each other out.

As 2 it can be seen further, the two piston rods 48 . 50 as a hollow body, formed with a arranged in the region of the piston transverse bore, so that a structurally favorable filling of Wirkräume 32 . 38 is possible.

At the in 3 illustrated embodiment is in the piston 46 of the compensation element 44 a valve 58 brought in. By means of the valve 58 can the two Wirkräume 32 . 38 connected together and thus the stabilizer function are turned off.

As 4 it can be seen in this embodiment at the inputs of the compensating element 44 each throttle valves 60 . 62 intended. As a result, a roll damping is possible in a simple manner.

A particularly advantageous embodiment of a hydraulic roll stabilizer system using the compensation element according to the invention 44 is in 5 shown. As a cylinder-piston unit now the suspension vibration damper 64 . 66 used. To the dampers 64 . 66 To use this, are the hydraulic lines 28 . 30 in the area of each working chamber 16 . 18 . 22 . 24 one damping throttle each 68 as well as one parallel to each damping throttle 68 arranged, the outflow from the respective working chamber 16 . 18 . 22 . 24 locking check valve 70 provided in order to avoid unnecessarily hard damping in bilateral compression by the flow through two series-connected throttles.

In Wankfall, so with different input / Ausfederwegen at two wheels of an axle, the hydraulic volume of a hydraulic circuit 28 . 30 after flowing through the respective damper throttle 68 in the compensation element 44 repressed. The hydraulic fluid, which at the same time from the compensation element 44 in the working chambers 16 . 18 . 22 . 24 the damper 64 . 66 the throttle can be transported 68 with the help of check valves 70 flow around so as not to create additional damping. In the case of equilateral compression or rebound, the hydraulic volume of a damper 64 crosswise in the other damper 66 repressed. The hydraulic fluid would be the throttle points 68 flow through both dampers. In order to maintain the desired damper characteristic here too, the check valves are also used here 70 for flowing around the unwanted damping throttle 68 needed.

LIST OF REFERENCE NUMBERS

10

Wankstabilisatorsystem

12

first cylinder-piston unit

14

second cylinder-piston unit

16

first working chamber of the first cylinder-piston unit

18

second working chamber of the first cylinder-piston unit

20

Piston of the first cylinder-piston unit

22

first working chamber of the second cylinder-piston unit

24

second working chamber of the second cylinder-piston unit

26

Piston of the second cylinder-piston unit

28

hydraulic line

30

hydraulic line

32

first effective space

34

Spring element of the first effective space

36

Piston of the first effective space

38

second effective space

40

Spring element of the second effective space

42

Piston of the second effective space

44

compensation element

46

Piston of the compensation element

48

piston rod

50

piston rod

52

spring plate

54

spring plate

56

spring Plate

58

Valve

60

throttle valve

62

throttle valve

64

chassis vibration

66

chassis vibration

68

damping throttle

70

check 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 19510533 [0002]
• DE 19719029 [0002]

Claims (10)

Compensation element ( 44 ) for a hydraulic roll stabilizer system of a motor vehicle, in which the opposite wheels of one axle each have a cylinder-piston unit (located between the motor vehicle body and the wheel suspension element (US Pat. 12 . 14 ), whose working chambers ( 16 . 18 . 22 . 24 ) in each case with the interposition of a spring-loaded active space ( 32 . 38 ) are cross-connected, characterized in that the two Wirkräume ( 32 . 38 ) arranged in a common housing and via a guided in the housing piston ( 46 ) are separated from each other, and the piston ( 46 ) two opposing, projecting from the housing, spring-loaded piston rods ( 48 . 50 ) having. Compensation element according to claim 1, characterized in that the piston rods ( 48 . 50 ) as hollow rods with one in the region of the piston ( 46 ) arranged transverse bore are formed. Compensation element according to claim 1 or 2, characterized in that between the two Wirkräumen ( 32 . 38 ) a valve ( 58 ) is introduced. Compensation element according to one of claims 1 to 3, characterized in that in the entrance to the two Wirkräumen ( 32 . 38 ) each a throttle valve ( 60 . 62 ) is arranged. Compensation element according to one of the preceding claims, characterized in that extending beyond the housing end of the piston rod ( 48 . 50 ) each a spring plate ( 52 . 54 ) and on the housing a spring support ( 56 ) is formed, and that between spring plate ( 52 . 54 ) and spring support ( 56 ) each have a spring element ( 34 . 40 ) is arranged. Compensation element according to claim 5, characterized in that between the spring element ( 34 . 40 ) and spring plate ( 52 . 54 ) or between spring element ( 34 . 40 ) and spring support ( 56 ) An axial bearing is arranged. Compensation element according to claim 5, characterized in that the spring element ( 34 . 40 ) is formed as a metal, gas, or elastomeric spring. Hydraulic roll stabilizer system ( 10 ) for an axle of a motor vehicle, comprising a respective one wheel of the axle associated, arranged between the motor vehicle body and a suspension element, first and second cylinder-piston unit ( 12 . 14 ) whose working chambers ( 16 . 18 . 22 . 24 ) via hydraulic lines ( 28 . 30 ) are cross-connected, characterized in that the hydraulic lines ( 28 . 30 ) with the interposition of a single compensating element ( 44 ) according to any one of claims 1 to 8 are interconnected crosswise. Hydraulic Wankstabilisatorsystem according to claim 8, characterized in that as a cylinder-piston unit, the suspension vibration damper ( 64 . 66 ), each working chamber ( 16 . 18 . 22 . 24 ) in its hydraulic line ( 28 . 30 ) a damping throttle ( 68 ) and a parallel thereto, the outflow from the respective working chamber ( 16 . 18 . 22 . 24 ) non-return valve ( 70 ), assigned. Hydraulic roll stabilizer system according to claim 8 or 9, characterized in that a control / regulating unit is provided, via which the valve ( 58 ) and / or the throttle valves ( 60 . 62 . 68 ) are actively controllable.

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