DE102005059113A1 - Actuator for active chassis frame of motor vehicle, has hydraulic or pneumatic adjustable cylinder that is connected in series to body spring and vibration damper, where damper is arranged parallel to body spring - Google Patents

Abstract

An actuator (2) for an active chassis of a motor vehicle is proposed, which comprises a body spring (5), a vibration damper (4) and a hydraulic or pneumatic actuating cylinder, the body spring (5) being designed to be fully load-bearing and the vibration damper (4 ) is connected in parallel to the body spring (5) and the actuating cylinder (3) in series with the body spring (5) and the vibration damper (4).

Description

The The present invention relates to an active chassis actuator Motor vehicle according to the preamble of claim 1

The Design of a conventional chassis for a motor vehicle provides a compromise between driving safety and comfort, as a hard damping ensures a good handling and a soft cushioning increases the comfort. Around to be able to combine both aspects are from the prior art active suspensions to compensate for Rolling and pitching and lifting movements known.

From the DE 196 06 991 A1 a spring-shock absorber device for a motor vehicle is known in which is controlled by a hydraulic unit, the distance of the vehicle body according to the handling of the vehicle relative to the wheels, wherein the spring between a movable element of the hydraulic unit and the damping cylinder of the shock absorber is clamped and the movable element of the hydraulic unit is slidably mounted on the shock absorber such that the displacement takes place exclusively in the region of the piston rod of the shock absorber, whereby the frictional forces during displacement of the movable element are largely reduced.

Furthermore, from the DE 196 04 558 C1 a piston-cylinder unit known, comprising a cylinder in which a piston rod is arranged axially movable, a first connected to the cylinder in operative connection member, a second connecting member, which is in communication with the piston rod, an adjusting cylinder with a pressure medium connection, wherein the adjusting cylinder is in operative connection with one of the connecting members and the supply between the first and the second connecting member is adjustable via supply or discharge from the pressure medium. Here, the adjusting cylinder is arranged in series with the cylinder and the piston rod is a guideway for the adjusting cylinder.

Furthermore, from the DE 195 29 580 A1 an adjustable strut for motor vehicles known which allow a good Legeregelung the sprung motor vehicle parts and should have a defined rule and tunable damping and spring rate. The shock absorber comprises a damper surrounded by a coil spring with a damper cylinder, wherein the coil spring on the one hand by a with the damper cylinder via an outer and an inner, the damper cylinder concentrically surrounding actuator cylinder, connected first spring plate and on the other hand by one in the vicinity of the articulation point of the piston rod Working piston of the damper cylinder with the piston rod connected second spring plate is held and clamped so that when retracting the piston in the damper cylinder, the coil spring is loaded. In this case, the two adjusting cylinders are designed to be telescopically displaceable relative to each other for changing the ground clearance of the body.

At the time of the DE 195 29 580 A1 known construction, the first spring plate is attached to the outer actuating cylinder, wherein the outer actuating cylinder has at its end facing the piston rod means for guiding and sealing the damper cylinder and at the opposite end means for guiding and sealing the inner actuating cylinder. Here, the inner actuating cylinder is attached to the damper cylinder and relative to the outer actuating cylinder by the introduction of a pressure medium in the limited by the adjusting cylinders and the damper cylinder annular interior telescopically.

As part of the DE 100 43 711 A1 an actuator for active suspension control using a torque-generating actuator is described, which is connected to the attached to the wheel and the vehicle body handlebars, wherein the actuator between the vehicle body and handlebar is arranged and a roll and pitch compensation corresponding and / or one Damping the handlebars fluctuations ensures torque to the handlebars. Preferably, the actuator is designed as a swivel motor.

Another actuator for active chassis control is from the DE 103 06 228 A1 known. It comprises an arranged between the wheel and vehicle body actuator, which compensates for pitching and rolling movements and also reduces the lifting movement of the vehicle according to the Skyhook principle. The actuator is designed as a swivel motor and provides between the wheel and the structure in addition to the actuator torque for roll and pitch compensation actuator torque to reduce the build-up stroke ready.

at this known from the prior art constructions is the Energy requirement due to the Fußpunktverstellung the suspension system or the actuation of the actuator in disadvantageous Way up.

Furthermore, under the DE 44 28 605 A1 a hydraulic system for an active chassis, in particular for compensating the roll and pitch movement described, comprising actuators each having a pressure accumulator for a front axle and a rear axle of a motor vehicle, a pump for supplying the actuators, inflow and Drain lines from the actuators to a tank, switching valves to control the actuators and an additional pressure accumulator for each vehicle axle. Here, the additional pressure accumulator is connected at substantially horizontal vehicle body position simultaneously with the actuators of a vehicle axle, separated at a turn from the outside actuator and connected to the inside of the curve actuator. Furthermore, an adjustable damper device is operatively associated with the actuators, to the extent that the curve-inner actuator is connected to the additional memory, the adjustable damper device for the curve-inner actuator is set to a stronger damping.

Of the The present invention is based on the object, an actuator for a Active chassis for active chassis control for influencing of pitching, lifting and rolling movements, indicating the function the level control has. In addition, the actuator of the landing gear according to the invention later be installed in vehicles.

These The object is solved by the features of claim 1. Further Embodiments of the invention and advantages are apparent from the dependent claims.

Therefore becomes an actuator for proposed an active chassis of a motor vehicle, which a body spring and a vibration damper comprising a hydraulic or pneumatic actuating cylinder, wherein the body of the body fully supporting is designed.

at the actuator according to the invention is the damping force for the Rebound and rebound over two per damping cylinder provided damping valves or over a combination of a damping valve and an integrated damping valve system independently adjustable from each other.

According to the invention The static dimensions of the actuator over the same pressure in the two workrooms the adjusting cylinder resulting differential force by the area difference from piston surface and piston rod surface worn, wherein the actuator is the force from the vehicle mass and from the payload and regulates a planned vehicle level. By the actuator according to the invention are the body movements by applying additional Tensile and compressive forces reduced, with the available standing suspension paths are load independent.

The The invention will be explained in more detail below by way of example with reference to the attached figures.

It demonstrate:

1 a schematic representation of an actuator according to the invention for an active chassis;

2 a schematic representation of the arrangement for controlling a hydraulic actuating cylinder of the actuator according to the invention for an active chassis and

3 a schematic representation of another embodiment of the arrangement for controlling a hydraulic actuating cylinder of the actuator according to the invention.

As in 1 illustrates comprises an actuator according to the invention 2 for an active chassis a hydraulic actuating cylinder 3 , a vibration damper 4 and a full-blown bodybuilder 5 ; the construction mass is with 1 and the unsprung wheel masses with 6 designated. Here is the vibration damper 4 parallel to the bodywork spring 5 connected; the actuating cylinder 3 is in series with the bodybuilder 5 and the vibration damper 4 connected. Although the invention will be explained with reference to an embodiment which has a hydraulic actuating cylinder, the actuating cylinder can also be designed pneumatically.

The static composition 1 be from the actuator 2 over the same pressure in the two working spaces of the actuating cylinder 3 resulting differential force carried by the area difference of the piston surface and piston rod surface, wherein the actuator 2 absorbs the force from the vehicle mass and from the payload and regulates an intended vehicle level. By the hydraulic actuator 2 The body movements are reduced by applying additional tensile and compressive forces, the available spring travel are independent of load.

In addition, the actuator compensates 2 the reaction forces from dynamic vehicle state changes that may occur, for example, when starting, when braking, when cornering or when driving road excitations.

By the conception according to the invention the stabilizer and the body of a conventional axle system substituted in an advantageous manner, wherein in the suspension area Space advantages arise because a hydraulic actuator in volltragender execution only slightly builds bigger as a conventional damper. The required ancillaries of the hydraulic actuator are preferably mounted on the vehicle body.

Another advantage is that the actuator of the active suspension according to the invention as an add-on solution subsequently or optionally with relatively little effort in existing axle systems can be integrated. In addition, the actuator is scalable within wide limits and can be used both in micro cars and in commercial trucks and buses.

In the 2 and 3 are two advantageous possibilities of the arrangement for controlling the actuator according to the invention or of the hydraulic rule actuating cylinder shown. Of course, further arrangements known to the person skilled in the art are also possible.

In the arrangement according to 2 can the damping force for the rebound and rebound over the two damping valves 7 per actuating cylinder 3 be set independently, whereby no adjustment of the damping valve for the one direction of movement is required, when the direction of movement reverses. This results in a more accurate and faster adjustment of the damping force, as compared to a system which has a valve for both directions of movement, which must disadvantageously jump in case of change of direction in each case to another control point. How out 2 As can be seen, it is parallel to each damping valve 7 a check valve 13 connected; in front of the valves 7 and 13 is a gas spring 8th connected.

The hydraulic actuator is designed so that the static state in both working spaces of the cylinder 3 Equally high static mean pressure supports the static wheel loads. Due to the different effective areas between the piston surface and piston rod surface creates a differential force, which generates the necessary lifting force.

According to the invention, dynamic wheel load changes in the low-frequency range (eg during normal cornering or sustained acceleration or braking) by changing the average working pressure in the working spaces of the cylinder 3 compensated, wherein a Radlasterhöhung results in an increase in pressure and a Radlastminderung in a pressure reduction. In this case, the pressure change takes place via the switching of the switching valves 9 , In the 2 is the hydraulic supply with 10 , the pressure valve with 11 and the tank for the hydraulic fluid with 12 designated. In the right part of the 2 is another possible embodiment of the switching valve 9 shown.

High frequency wheel load changes (eg in the case of a sudden lane change or the pitching oscillation occurring at the beginning of braking) are caused by the damping valves 7 partially compensated in terms of comfort and can supplement the gain in driving safety and comfort in conjunction with eg CDC valves or ASD valves or similar systems.

In the 3 shown arrangement differs from the arrangement according to 2 in that for adjusting the damping force for the rebound and rebound movement, an integrated damping valve system 14 is provided, which is arranged outside the actuating cylinder and has separate working spaces. The damping valve system can also connect both working spaces of the actuating cylinder and be carried out regulated or unregulated.

Here, the damping force when rebounding alone from the damping valve system 14 determines while damping the wheel, the damping force from a combination of the damping valve system 14 with the damping valve 7 comes to fruition. The damping valve system 14 and the damping valve 7 can be set or regulated independently of each other.

By The present invention is an actuator for an active chassis for disposal asked, which the integration of functions Hub and / or pitch and / or Wank and / or level compensation in an actuator for each wheel allows and substituted a conventional or passive stabilizer. moreover For example, the actuator can be used in any vehicle (e.g., single or dual track with any number of axes).

at Design of the hydraulic actuator to a pressure level of about 150 bar to 180 bar, the space of the conventional damper can be used become. Furthermore, the actuator can be retrofitted in an advantageous manner Vehicles are installed and leaves to combine with all systems of existing dampers (passive Damping, CDC, ASD, Skyhook principles). In addition, a retrofit to a purely passive System conceivable.

Of course, too any constructive training, especially any spatial Arrangement of the components of the actuator according to the invention for an active Chassis and the arrangement for controlling the actuating cylinder in itself and to each other and as far as technically reasonable, among the Scope of the present claims without the function of Actuators as specified in the claims is to influence, even if these training is not explicit are shown in the figures or in the description.

1

body mass

2

actuator

3

hydraulic actuating cylinder

4

vibration

5

body spring

6

unsprung wheel masses

7

damping valve

8th

gas spring

9

switching valve

10

hydraulic supply

11

pressure valve

12

tank

13

check valve

Claims (6)

Actuator for an active chassis of a motor vehicle, comprising a body spring and a vibration damper, characterized in that it comprises a hydraulic or pneumatic actuating cylinder, wherein the body is designed to be fully supporting and wherein the vibration damper ( 4 ) parallel to the mounting spring ( 5 ) and the actuating cylinder ( 3 ) in series with the assembly spring ( 5 ) and the vibration damper ( 4 ) is switched. Actuator for an active chassis of a motor vehicle according to claim 1, characterized in that it is designed such that the static structure ( 1 ) from the actuator ( 2 ) over the same pressure in the two working spaces of the adjusting cylinder ( 3 ) are borne by the surface difference of the piston surface and the piston rod surface of the actuating cylinder, wherein the actuator ( 2 ) absorbs the force from the vehicle mass and from the payload and regulates an intended vehicle level and compensates for the reaction forces from dynamic vehicle state changes. Actuator for an active chassis of a motor vehicle according to claim 1 or 2, characterized in that the actuating cylinder ( 3 ) two damping valves ( 7 ) are assigned such that the damping force for the rebound and rebound over the two damping valves ( 7 ) is independently adjustable, with parallel to each damping valve ( 7 ) a check valve ( 13 ) and in front of the valves ( 7 ) and ( 13 ) a gas spring ( 8th ) is switched. Actuator for an active chassis of a motor vehicle according to claim 1 or 2, characterized in that for adjusting the damping force for the compression and rebound movement, an integrated damping valve system ( 14 ) is provided, which outside of the adjusting cylinder ( 3 ) is arranged and has separate work spaces or both working spaces of the actuating cylinder ( 3 ), wherein it is carried out regulated or unregulated, wherein the rebound damping force alone from the damping valve system ( 14 ), while during compression of the wheel ( 6 ) the damping force from a combination of the damping valve system ( 14 ) with a damping valve ( 7 ) is determined. Actuator for an active chassis of a motor vehicle according to claim 4, characterized in that the damping valve system ( 14 ) and the damping valve ( 7 ) are independently adjustable or controllable. Actuator for an active chassis of a motor vehicle according to one of the preceding claims, characterized in that it comprises a switching valve ( 9 ), wherein in the case of a hydraulic actuating cylinder ( 3 ) whose control is designed such that dynamic Radlaständerungen in the low-frequency range by changing the average working pressure in the working chambers of the cylinder ( 3 ) are compensated, wherein a Radlasterhöhung in an increase in pressure and a Radlastminderung results in a pressure reduction, with higher frequency Radlaständerungen by the damping valves ( 7 ) or the damping valve system ( 14 ) are partially compensated according to comfort considerations.