Patent Application
20240317011
This application claims priority to German Patent Application No. 10 2023 107 020.7, filed Mar. 21, 2023, the content of such application being incorporated by reference herein in its entirety.
The present invention relates to 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. The invention also relates to a motor vehicle having such a damping system.
EP 3 357 722 A1, which is incorporated by reference herein, discloses a passive 2-valve damper, in which a differential pressure between a pressure line and a suction line is controlled by means of a differential pressure valve.
U.S. Pat. No. 11,448,283 B2, which is incorporated by reference herein, discloses a further passive 2-valve damper, this time with a boost valve, by means of which a damping is adjustable. The boost valve is arranged separately from the piston of the damper.
EP 2 937 596 B1, which is incorporated by reference herein, discloses a damper, in which a damping force variation is enabled by means of a damping controller. The damping controller is in this case arranged within a piston.
EP 2 165 089 B1, which is incorporated by reference herein, discloses a damper having a damper cylinder, in which a piston ram is guided via a piston rod, wherein, for adjusting damper characteristics, the flow of a damper fluid is controllable via control means arranged within the damper cylinder, and wherein the control means control the flow of the damper fluid in a first flow direction with first adjustment means and in a second flow direction with second adjustment means. The first and second adjustment means are respectively designed as at least one spring element, wherein, for specifying a damping behavior, the spring rate of at least one of the spring elements is adjustable via corresponding specification means. By maintaining the proven leaf spring principle of a passive damper, a specification of the damping behavior is to be achieved through the adjustability of the spring rate of a spring-loaded throttle opening of the piston ram.
DE 11 2010 003 954 T5, which is incorporated by reference herein, discloses a damper having a digital valve, wherein a damping force variation is adjustable by means of a damping controller. The damper comprises a plurality of digital valves. The damping controller comprises a passive valve, which is arranged within a piston, and an active digital valve, which is arranged within a piston rod.
EP 3 015 736 B1, which is incorporated by reference herein, discloses a shock absorber, in which a piston is arranged within a cylinder and a controllable 2-way valve is arranged in the piston. In addition, an inlet check valve and an outlet check valve for the outflow of a working fluid are provided on the piston.
U.S. Pat. No. 2,016,263 960 A1, which is incorporated by reference herein, discloses a shock absorber with an adjustable valve in the piston so that a working fluid can controllably flow through the piston.
DE 10 2015 211 556 B4, which is incorporated by reference herein, discloses a damper valve device, wherein a controllable throttle valve and a damper valve having two passage direction openings (suction and pressure) are provided. The throttle valve is in this case arranged on the cylinder.
It is disadvantageous in the damping systems known from the prior art that, with them, a damping force variation at low damper speeds is not possible or only possible to an extremely limited extent.
The present invention therefore relates to the problem of specifying an improved or at least an alternative embodiment for a damping system of the generic type, which embodiment in particular overcomes the disadvantages known from the prior art.
The present invention relates to the general idea of increasing or decreasing a damping force variation at low damper speeds in that, in an active shock absorber with two throttle check valves, an additional two-way straight-through and controllable throttling device is arranged in a piston of the actively controllable shock absorber. As a result, in particular at low damper speeds, i.e., with a slow retraction and extension, the damper force can be adjusted or influenced without any problems. This controls the force gradient in the force build-up and force reduction, which can significantly improve the target conflict of driving comfort and driving dynamics. The mechanically predetermined and thus non-adjustable force gradient of the shock absorber very often does not correspond to the one that is required for the required build-up or the wheel damping. If the latter is too large, overdamping results; if it is too small, underdamping results. The damping system according to aspects of the invention has the aforementioned actively controllable shock absorber having a first working space and a second working space, which are separated from one another by the piston, and wherein the piston rod of the piston extends through the second working space. Also provided is a hydraulic pump for conveying a hydraulic medium via a corresponding main line into the first or the second working space. The hydraulic pump can in this case be operated forward or in reverse, whereby a comparatively fast adjustment of a damping behavior of the actively controllable shock absorber can be achieved. According to aspects of the invention, the first working space is now communicatively connected to a hydraulic reservoir via a first controllable throttle check valve, just like the second working space is communicatively connected to the hydraulic reservoir via a second controllable throttle check valve. The two throttle check valves are also communicatively connected to one another. According to aspects of the invention, the aforementioned two-way straight-through and controllable throttling device, which connects the first and the second working space, is now arranged in the piston. By means of this controllable throttling device, it is possible to achieve a comparatively fast adjustment of a damping force at low damper speeds, whereby a significantly improved adjustment of the overall damping behavior is enabled. This can in particular achieve a significantly more comfortable driving behavior. Through the arrangement of the controllable throttling device in the piston, the latter can also be arranged in a more installation space-saving and at the same time protected manner.
Expediently, 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. Through the opposite orientation of the two throttle check valves, both compression movements and rebound movements can be dampened. Even if the hydraulic pump fails, the damping system still functions as a semi-active 2-valve damper.
In an advantageous development, the hydraulic reservoir is communicatively connected to the secondary line. For example, the hydraulic reservoir is connected between the first and second throttle check valves to the secondary line, whereby a supply of the damping system with hydraulic medium can be achieved independently of a compression or rebound process.
In a further advantageous embodiment of the damping system according to aspects of the invention, the hydraulic pump is arranged in a main line connecting the two working spaces, wherein the secondary line is connected upstream and downstream of the hydraulic pump to the main line. The secondary line with the two throttle check valves and the main line with the hydraulic pump are thus connected in parallel. This can achieved that, in normal operation, the first and second throttle check valves as well as the controllable throttling device only insignificantly intervene. Only with a desired or required adjustment of the damper force does the controllable throttling device intervene and adjusts the damping force without any problems even at low damper speeds. The main line with the hydraulic pump is in this case communicatively connected to the first working space.
In a further advantageous embodiment of the damping system according to aspects of the invention, the first throttle check valve comprises a controllable first throttle and a first check valve arranged in parallel thereto. Additionally, or alternatively, the second throttle check valve can comprise a controllable second throttle and a second check valve arranged in parallel thereto. Through the controllability of the first and/or the second throttle in the respectively associated first or second throttle check valves, a re-refined control of the damping system or an adjustment of the damper force can be achieved. Provided for this purpose is, for example, a control device that receives corresponding values for controlling the damping system, via corresponding sensors, e.g., pressure sensors and/or speed sensors.
The present invention furthermore relates to the general idea of equipping a motor vehicle with such a damping system and thereby creating an active wheel suspension, which enables a variation of the damping force without any problems even at low damper speeds.
The controllable throttling device is in this case two-way straight-through and thus, in the open state, acts in a damping force-reducing manner at low damper speeds.
In a further advantageous embodiment of the motor vehicle according to aspects of the invention, the latter is designed as an electric or hybrid vehicle. Particularly in electric vehicles, due to the inherently lower noise levels in these vehicles, other factors, such as anxious driving behavior, are noticed more strongly by a driver and are more quickly perceived as unpleasant. The damping system according to aspects of the invention can thus offer a significant enhancement in comfort, in particular in electric vehicles.
Further important features and advantages of the invention arise from the claims, from the drawing, and from the associated figure description with reference to the drawing.
It is understood that the aforementioned features and the features yet to be explained below are usable not only in the respectively specified combination but also in other combinations, or on their own, without departing from the scope of the invention as defined by the claims. The aforementioned components and the components to be mentioned below of a higher-level unit, such as a device, an apparatus, or an assembly, which are designated separately, can constitute separate components of this unit, or integral regions or sections of this unit, even if shown differently in the drawing.
Preferred exemplary embodiments of the invention are shown in the drawing and explained in further detail in the following description, wherein identical reference numbers refer to identical, similar, or functionally identical components.
The following are shown schematically:
According to
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.
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 FD at small damper speeds VD can be achieved via the controllable throttling device 18, as shown in
F
2≈3 F1.
Of course, depending on the design of the controllable throttling device 18, other ratios can also be represented.
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 FD can thus be achieved even at low damper speeds vD.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 107 020.7 | Mar 2023 | DE | national |
