DE102009029059A1 - Method for adjusting vibration damper in chassis for motor vehicle, involves carrying vibration damper at only one axle - Google Patents

Abstract

The method involves carrying vibration damper at only one axle. The adjustment carries the speed of the structure movement and the change per time unit. A front axle (5) and a rear axle (7) is provided in the vehicle, where a vibration damper (9,13) is arranged at each axle. An independent claim is also included for a vibration damper with an electronic unit.

Description

The invention relates to a method for adjusting adjustable vibration damper in a chassis according to the preamble of claim 1.

Suspensions with adjustable damping force are widely used in top-of-the-range vehicles, as the additional costs compared to a conventional vibration damper are accepted by the customer. Also in the vehicle middle class are adjustable vibration dampers as an option on offer. In small cars, which are often used as a second vehicle, there is currently no significant spread of an electrically adjustable vibration damper, since there the cost pressure is significantly greater. It should be noted that in the course of the vehicle life is a replacement of the worn vibration damper pending, and a vibration damper with adjustable damping force can not be easily replaced by a conventional design because z. B. via the control unit an error message would be signaled.

Nevertheless, in order to achieve a good ride comfort in conjunction with safe driving characteristics, partially mechanically adjustable vibration dampers, such as displacement-dependent adjustable or amplitude-dependent vibration dampers, are used.

The object of the present invention is to provide a cost-effective solution for a chassis, which should also meet increased demands in terms of comfort and driving safety.

According to the invention, the object is achieved in that the setting for adjustable vibration damper takes place on only one axis, wherein the adjustment takes place in dependence on the speed of the body movement and the change per unit time.

By multiple evaluation of a signal representing the body movement, a very good result can be achieved with simple means, in particular in comparison to a method in which only the speed of the body movement flows into a regulation.

In a further advantageous embodiment, the signal for adjusting the damping force can be modulated several times. So there is z. B. the possibility that enters the setting a signal representing the roadway quality and / or the adjustment of the vibration damper in response to the driving speed.

Furthermore, one can detect the direction of movement of the vehicle body and incorporate it into the setting of the vibration damper.

In view of low system costs, the sensor system is formed by an acceleration sensor, which is arranged in an electronic unit for the adjustable vibration dampers. This spatially very small unit can preferably be assigned to the rear axle.

A preferred attachment point is in the vicinity of the vibration damper attachment. It only needs a short wiring, so that the possibility of retrofitting in a previously conventional suspension is possible.

According to an advantageous subclaim, at least one vibration damper with a hydraulic-mechanical damping force adjustment that is independent of the sensor system is arranged on a second vehicle axle.

In a very rapid change of the damping force setting from a soft damping force curve to a hard damping force curve, the vehicle can make a pitching motion about a vehicle transverse axis. The hydraulic-mechanical damping force adjustment counteracts this effect with simple means. So z. B. vibration damper with tensile or pressure stops are used. Exemplary is on the DE 198 29 765 A1 directed.

The vibration damper may alternatively have a path-dependent Dämpfkrafseinstellung on the second vehicle axle, such. B. from the DE 196 18055 C1 is known.

In one embodiment, the vibration damper on the second vehicle axle may have a damping valve which, in the case of a larger stroke movement, transitions from a passage position into a closed position. Such a construction is z. B. from the EP 1 538 367 B1 known.

The invention will be explained in more detail with reference to the following description.

1 Schematic representation of a vehicle with adjustable damping force on a vehicle axle

2 System description for the method for adjusting the damping force on a vehicle axle

The 1 shows a schematic representation of a motor vehicle 1 with a vehicle body 3 that of a front axle 5 and a rear axle 7 will be carried. The front axle 5 has at least one vibration damper 9 Conventional design, ie that the vibration damper 9 follows a single damping force characteristic. In the front area is a vehicle engine 11 arranged. Also the rear axle 7 has at least one vibration damper 13 on. At only one of the two vehicle axles are vibration absorbers 13 arranged with adjustable damping force. By way of example, a vibration damper according to the designs according to the DE 36 09 862 A1 directed. These vibration dampers or adjustable damping valves 15 are with an electronics unit 17 connected. The electronics unit receives signals from an acceleration sensor 19 that is preferred within the electronics unit 17 in the immediate vicinity of the connection of the adjustable vibration damper 13 to the vehicle body 3 ,

In the present embodiment, the vehicle axle 5 , in the vicinity of the vehicle engine 11 is arranged with not arbitrarily adjustable vibration dampers 9 equipped. Preferably, the vibration damper on this vehicle axle 5 with one of the sensors 19 independent hydraulic-mechanical Dämpfkraftverstellung executed. Thus, the vibration damper on the second vehicle axle having a path-dependent Dämpfkrafseinstellung or a damping valve, which merges at a higher stroke speed, starting from a passage position into a closed position.

The loading of the vehicle interior, in particular a trunk 21 caused load, is on the engine-side vehicle axle 5 relative to the rear axle 7 significantly lower, so that on this axis 5 a comfortable driving behavior can be achieved with a single damping force characteristic of a conventional vibration damper. The Dämpfkraftkennlinie is dependent on the load of the vehicle front axle 5 clearly progressive designed, as already above to the vibration 9 executed.

Overall, a cost-effective compromise can be achieved with this simple solution. Due to the single-axis arrangement, one can also use the computer power of the electronics unit 17 reduce in comparison to a two-axis arrangement, so that there is also a savings potential on this module.

The 2 intended the method of adjusting the vibration damper 13 clarify. In the electronics unit 17 becomes a vertical acceleration signal a of the vehicle body 3 and a vehicle speed signal v is input. The vertical acceleration signal a and the vehicle speed signal v are directly a computing device 23 fed. Furthermore, from the vertical acceleration signal a in a first module 25 generates a lane signal a _Str . In a parallel process step is in an integrating module 27 from the vertical acceleration a, the vertical body speed a _v determined. With the help of a differentiation module 29 the change of the body acceleration a _{R is} determined. The two last-mentioned detected signals a _v ; A _{R also} go into the computer module 23 directly. The change in body acceleration a _R signal serves to more accurately detect and predict the vehicle body movement characteristics such that the change in vehicle body movement speed in the adjustment of the damping valves 15 to the vibration damper 13 received.

From the output signal of the vertical acceleration a of the sensor 19 can be the direction of movement of the vehicle body 3 determine. These directional vertical _{acceleration signals} a _v1 ; a _v2 are each with the signal v of the driving speed in a proportional module 31 ; 33 connected. These driving speed-influenced signals a _vv1 , a _vv2 , are then in modules 35 ; 37 with an output signal A _{R of} the computer unit 23 connected. This is followed by a module 39 the connection of the respective signal a _vvAR1 , a _vvAR2 with the roadway signal a _Str . Possibly. can still another interface 41 for another input signal, z. B. over a target of the driver with regard to the tendency of suspension tuning as hard or soft, are used. The output signal I _D stands for a desired current, with which the valve or the adjustable valves 15 be applied to achieve the desired Dämpfkrafseinstellung. The signal for the desired current I _D is, in order to close the control loop, the computer unit 23 fed.

LIST OF REFERENCE NUMBERS

1

motor vehicle

3

vehicle body

5

Front

7

rear axle

9

vibration

11

vehicle engine

13

adjustable vibration damper

15

adjustable damping valve

17

electronics unit

19

sensors

21

trunk

23

computer unit

25

module

27

integration module

29

Differentiating module

31; 33

proportional module

35-39

module

41

interface

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 19829765 A1 [0012]
• DE 19618055 C1 [0013]
• EP 1538367 B1 [0014]
• DE 3609862 A1 [0018]

Claims (9)

Method for adjusting adjustable vibration dampers ( 9 ) in a chassis for a motor vehicle ( 1 ) with at least one front axle ( 5 ) and at least one rear axle ( 7 ), wherein on each vehicle axle ( 5 ; 7 ) at least one vibration damper ( 9 ; 13 ) is arranged and the setting due to vehicle dynamics parameters of the motor vehicle ( 1 ), which by means of a sensor ( 19 ), characterized in that the setting for vibration dampers ( 13 ) on only one axis ( 7 ), wherein the adjustment is made as a function of the speed (v) of the body movement and its change (a _R ) per unit of time. Method according to Claim 1, characterized in that a signal (a _Str ) representing the roadway quality is included in the setting. A method according to claim 1, characterized in that the adjustment of the vibration damper ( 13 ) takes place as a function of the driving speed (v). A method according to claim 1, characterized in that the direction of movement of the vehicle body ( 3 ) and in the adjustment of the vibration damper ( 13 ). Vibration damper for a method according to claim 1, characterized in that the sensors ( 19 ) is formed by an acceleration sensor, which in an electronic unit ( 17 ) for the adjustable vibration dampers ( 13 ) is arranged. Vibration damper according to claim 5, characterized in that the sensors ( 19 ) is disposed in the vicinity of the vibration damper attachment. Vibration damper according to claim 5, characterized in that on a second vehicle axle ( 5 ) at least one vibration damper ( 9 ) with one of the sensors ( 19 ) is arranged independent hydraulic-mechanical Dämpfkraftverstellung. Vibration damper according to claim 7, characterized in that the vibration damper ( 13 ) on the second vehicle axle ( 5 ) has a path-dependent damping force setting. Vibration damper according to claim 7 or 8, characterized in that the vibration damper ( 9 ) on the second vehicle axle ( 7 ) has a damping valve, which merges at a larger stroke movement, starting from a passage position into a closed position.

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