DAMPING SYSTEM FOR MOTOR VEHICLE

Abstract

A damping system with an actively controllable shock absorber having a first working space and a second working space, which are separated from one another by a piston. A hydraulic pump conveys a hydraulic medium into the first working space or into the second working space. In order to dampen fast compression or rebound movements, the first working space is communicatively connected to a hydraulic reservoir via a first controllable throttle check valve, the second working space is communicatively connected to the hydraulic reservoir via a second controllable throttle check valve, and a two-way straight-through and controllable throttling device, which connects the first working space to the second working space in the open state, is arranged in the piston.

Claims

1. A damping system for a motor vehicle, said damping system comprising: an actively controllable shock absorber having a first working space and a second working space that are separated from one another by a piston, wherein a piston rod of the piston extends through the second working space, a hydraulic pump for conveying a hydraulic medium into either the first working space or the second working space, a first controllable throttle check valve communicatively connecting the first working space to a hydraulic reservoir, a second controllable throttle check valve communicatively connecting the second working space to the hydraulic reservoir, and a two-way straight-through and controllable throttling device arranged in the piston and which, in an open state of the throttling device, connects the first working space to the second working space.

2. The damping system according to claim 1, wherein the first throttle check valve and the second throttle check valve are arranged in a secondary line, wherein the first throttle check valve is oriented opposite to the second throttle check valve.

3. The damping system according to claim 2, wherein the hydraulic reservoir is communicatively connected to the secondary line.

4. The damping system according to claim 2, wherein the hydraulic pump is arranged in a main line connecting the first and second working spaces, wherein the secondary line is connected upstream and downstream of the hydraulic pump to the main line.

5. The damping system according to claim 1, wherein (i) the first controllable throttle check valve comprises a controllable first throttle and a first check valve arranged in parallel thereto, and/or (ii) the second controllable throttle check valve comprises a controllable second throttle and a second check valve arranged in parallel thereto.

6. A motor vehicle having the damping system according to claim 1.

7. The motor vehicle according to claim 6, wherein the motor vehicle is an electric or hybrid vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following are shown schematically:

[0025] FIG. 1 is a representation of a damping system according to aspects of the invention in a motor vehicle according to aspects of the invention, and

[0026] FIG. 2 is a speed-force diagram for illustrating the mode of action of the damping system according to aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0027] According to FIG. 1, a damping system 1 according to aspects of the invention in a motor vehicle 2, in particular in an electric or hybrid vehicle, comprises an actively controllable shock absorber 3 having a first working space 4 and a second working space 5. The two working spaces 4, 5 are separated from one another by a piston 6, wherein a piston rod 7 extends through the second working space 5. The size of the two working spaces 4, 5, of course, depends on the position of the piston 6 and is consequently variable. Furthermore provided is a hydraulic pump 8, which conveys hydraulic medium into the first working space 4 or the second working space 5, depending on the conveying direction. The hydraulic pump 8 is used for active damping force support of the shock absorber 3 and can convey the hydraulic medium in both directions. The hydraulic pump 8 is in this case integrated into a main line 9, which connects the hydraulic pump 8 to both the first working space 4 and the second working space 5.

[0028] The first working space 4 is communicatively connected to a hydraulic reservoir 11 via a first controllable throttle check valve 10, while the second working space 5 is communicatively connected to the hydraulic reservoir 11 via a second controllable throttle check valve 12. The first throttle check valve 10 comprises a controllable first throttle 13 and a first check valve 14 arranged in parallel thereto, wherein the second throttle check valve 12 additionally or alternatively comprises a controllable second throttle 15 and a second check valve 16 arranged in parallel thereto. The first throttle check valve 10 and the second throttle check valve 12 are arranged in a secondary line 17 and are arranged in parallel to the hydraulic pump 8 arranged in the main line 9. The secondary line 17 is communicatively connected upstream and downstream of the hydraulic pump 8 to the main line 9.

[0029] According to aspects of the invention, a two-way straight-through and controllable throttling device 18, which connects the first working space 4 to the second working space 5 in the open state, is now arranged in the piston 6. The two-way straight-through passage is symbolized by the two arrows. A variation of the damping force F.sub.D at small damper speeds V.sub.D can be achieved via the controllable throttling device 18, as shown in FIG. 2. Thus, if, for example, the controllable throttling device 18 is opened, the slope of the damping force straight line F.sub.D decreases from F.sub.D with the throttling device 18 not open to F.sub.DZ with the throttling device 18 fully open. With the throttling device 18 not open, the slope corresponds to that of a semi-active 2-valve damper 19 without hydraulic pump 8 and without throttling device 18. With the throttling device 18 open, the damping force F.sub.DZ also decreases at low damper speeds V.sub.D, for example at a damper speed V.sub.D1 from F.sub.1 to F.sub.2, wherein the following relationship applies according to the representation in FIG. 2:

F.sub.2?3 F.sub.1.

[0030] Of course, depending on the design of the controllable throttling device 18, other ratios can also be represented.

[0031] All in all, with the damping system 1 according to aspects of the invention and the motor vehicle 2 according to aspects of the invention, a significantly improved variation of the damping force F.sub.D can thus be achieved even at low damper speeds v.sub.D.

[0032] At low damper speeds, the non-variable damping gradient fixedly predetermined by the two control valves can thus be adjusted to the force requirement, and overdamping or underdamping in the range of small damper speeds can be prevented. This applies in particular during the change of the damper speed from the suction direction to the pressure direction.