US-12624739-B2 - Controllable vibration damper

US12624739B2US 12624739 B2US12624739 B2US 12624739B2US-12624739-B2

Abstract

A controllable vibration damper includes a damping force control system, having a damper housing tube. The damper is at least partially filled with a damping medium. A damping valve for damping force control is arranged on and fluidly connected to the damper housing tube. The damper housing tube has an inner tube, which is inserted into the tubular damper housing via a bottom valve element. The vibration damper has a piston rod, which can be moved longitudinally in the inner tube and has a working piston.

Inventors

Juergen Schneider
Michael Sturm

Assignees

THYSSENKRUPP BILSTEIN GMBH
THYSSENKRUPP AG

Dates

Publication Date: 20260512
Application Date: 20210831
Priority Date: 20200914

Claims (16)

1 . A controllable vibration damper having a damping force control system, the controllable vibration damper comprising: a tubular damper housing which is at least partially filled with damping medium, and a damping valve element for damping force control, which is arranged on and fluidly connected to the tubular damper housing; an inner tube, which is inserted into the tubular damper housing via a bottom valve element; a piston rod, which can be moved longitudinally in the inner tube and has a working piston; wherein the bottom valve element divides the tubular damper housing into a low-pressure working chamber and a high-pressure working chamber, which is acted upon by means of the working piston; and a separating piston seated in the tubular damper housing that separates the damping medium in the low-pressure working chamber from a gas volume held in the tubular damper housing; wherein an inlet opening of the damping valve element is fluidly connected to the high-pressure working chamber, and an outlet opening of the damping valve element is fluidly connected to the low-pressure working chamber, such that the damping valve element is connected in parallel with the working piston; wherein the damping valve element can be closed during a rebound stage such that the damping medium can be forced to flow through the working piston and through the bottom valve element without flowing through the damping valve element; wherein the damping valve element can be opened during the rebound stage such that the damping medium can be forced to flow through the working piston, through the bottom valve element, and through the damping valve element.
2 . The controllable vibration damper as claimed in claim 1 , wherein the inner tube is inserted into the tubular damper housing via the bottom valve element in such a way that the bottom valve element is inserted into the tubular damper housing on the inner circumference and forms a hydraulic seal with the inner tube.
3 . The controllable vibration damper as claimed in claim 2 wherein the damping valve element is selectively adjusted continuously between any desired minimum damper characteristic and any desired maximum damper characteristic.
4 . The controllable vibration damper as claimed in claim 3 , wherein the damper valve element has at least one controllable valve unit, by means of which the damper characteristic is selectively switched.
5 . The controllable vibration damper as claimed in claim 4 , wherein the at least one controllable valve unit comprises one of a manually, electrically and electromagnetically adjustable valve for switching the damper characteristic.
6 . The controllable vibration damper as claimed in claim 5 , wherein the at least one controllable valve unit is a first valve unit and the controllable vibration damper further comprises a second valve unit with a defined flow cross section connected one of upstream and downstream of the first valve unit in the flow direction of the damping medium.
7 . The controllable vibration damper as claimed in claim 1 , wherein: the damping valve element can be closed during the rebound stage such that the damping medium is forced to flow through the working piston, from a piston-rod side of the working piston to a region remote from the piston rod, and through the bottom valve element, from the low-pressure working chamber into the high-pressure working chamber, without flowing through the damping valve element, such that no damping force is produced by the damping valve element and a hard characteristic is provided by the controllable vibration damper; and the damping valve element can be opened during the rebound stage such that the damping medium is forced to flow through the working piston, from a piston-rod side of the working piston to a region remote from the piston rod, through the bottom valve element, from the low-pressure working chamber into the high-pressure working chamber, and through the damping valve element, from the high-pressure working chamber into the low-pressure working chamber, such that a damping force is produced by the damping valve element and a soft characteristic is provided by the controllable vibration damper.
8 . The controllable vibration damper as claimed in claim 1 , wherein the inlet opening and the outlet opening are the only openings that fluidly connect the damping valve element to the rest of the controllable vibration damper.
9 . A controllable vibration damper having a damping force control system, the controllable vibration damper comprising: a tubular damper housing which is at least partially filled with damping medium, and a damping valve element for damping force control, which is arranged on and fluidly connected to the tubular damper housing; an inner tube, which is inserted into the tubular damper housing via a bottom valve element; a piston rod, which can be moved longitudinally in the inner tube and has a working piston; wherein the bottom valve element divides the tubular damper housing into a low-pressure working chamber and a high-pressure working chamber, which is acted upon by means of the working piston; and a separating piston seated in the tubular damper housing that separates the damping medium in the low-pressure working chamber from a gas volume held in the tubular damper housing; wherein an inlet opening of the damping valve element is fluidly connected to the high-pressure working chamber, and an outlet opening of the damping valve element is fluidly connected to the low-pressure working chamber, such that the damping valve element is connected in parallel with the working piston; wherein the damping valve element can be closed during a compression stage such that the damping medium can be forced to flow through the working piston and through the bottom valve element without flowing through the damping valve element; wherein the damping valve element can be opened during the compression stage such that the damping medium can be forced to flow through the working piston, through the bottom valve element, and through the damping valve element.
10 . The controllable vibration damper as claimed in claim 9 , wherein the inner tube is inserted into the tubular damper housing via the bottom valve element in such a way that the bottom valve element is inserted into the tubular damper housing on the inner circumference and forms a hydraulic seal with the inner tube.
11 . The controllable vibration damper as claimed in claim 10 wherein the damping valve element is selectively adjusted continuously between any desired minimum damper characteristic and any desired maximum damper characteristic.
12 . The controllable vibration damper as claimed in claim 11 , wherein the damper valve element has at least one controllable valve unit, by means of which the damper characteristic is selectively switched.
13 . The controllable vibration damper as claimed in claim 12 , wherein the at least one controllable valve unit comprises one of a manually, electrically and electromagnetically adjustable valve for switching the damper characteristic.
14 . The controllable vibration damper as claimed in claim 13 , wherein the at least one controllable valve unit is a first valve unit and the controllable vibration damper further comprises a second valve unit with a defined flow cross section connected one of upstream and downstream of the first valve unit in the flow direction of the damping medium.
15 . The controllable vibration damper as claimed in claim 9 , wherein: the damping valve element can be closed during the compression stage such that the damping medium is forced to flow through the working piston, from a region remote from the piston rod to a piston-rod side of the working piston, and through the bottom valve element, from the high-pressure working chamber into the low-pressure working chamber, without flowing through the damping valve element, such that no damping force is produced by the damping valve element and a hard characteristic is provided by the controllable vibration damper; and the damping valve element can be opened during the compression stage such that the damping medium is forced to flow through the working piston, from a region remote from the piston rod to a piston-rod side of the working piston, through the bottom valve element, from the high-pressure working chamber into the low-pressure working chamber, and through the damping valve element, from the high-pressure working chamber into the low-pressure working chamber, such that a damping force is produced by the damping valve element and a soft characteristic is provided by the controllable vibration damper.
16 . The controllable vibration damper as claimed in claim 9 , wherein the inlet opening and the outlet opening are the only openings that fluidly connect the damping valve element to the rest of the controllable vibration damper.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Stage Entry of International Patent Application Serial Number PCT/EP2021/074007, filed Aug. 31, 2021, which claims priority to German Patent Application No. DE 10 2020 211 490.0, filed Sep. 14, 2020, the entire contents of which are incorporated herein by reference. FIELD The present disclosure generally relates to a controllable vibration damper having a damping force control system and a damper housing tube. BACKGROUND The prior art discloses vibration dampers in which two control valves arranged hydraulically in parallel with the working piston are provided, through one of which the damping medium flows in the compression stage, during the retraction movement of the piston rod, and through the other of which it flows in the rebound stage, during the extension movement of the piston rod. For this purpose, EP 1 538 399 A1 provides control valves, each accommodated in separate housings. DE 10 2008 015 412 A1 describes a solution in which the two control valves are accommodated in a common housing and are flowed through by suitable inflow in the compression stage or rebound stage. These vibration dampers are constructed as a 2-tube configuration, with an inner tube and a tubular damper housing surrounding the latter. Furthermore, vibration dampers are known which operate according to the “uniflow” principle and are constructed in a 3-tube configuration. In this case, only one control valve is provided, through which the flow is always unidirectional as a result of the uniflow principle, irrespective of the compression stage and rebound stage. While it would therefore be desirable, for the sake of simplification, in the case of vibration dampers of 2-tube configuration, to provide just one control valve, it would be desirable in the case of vibration dampers based on the uniflow principle to embody this in a 2-tube configuration. Thus a need exists to provide a vibration damper which, as outlined above, makes use of both embodiments. The present disclosure provides a controllable vibration damper having a damping force control system, comprising a damper housing tube, which is at least partially filled with damping medium, and a damping valve for damping force control, which is arranged on and fluidly connected to the damper housing tube, an inner tube, which is inserted into the tubular damper housing via a bottom valve element, a piston rod, which can be moved longitudinally in the inner tube and has a working piston, wherein according to the invention a separating piston seated in the tubular damper housing separates the damping medium in the low-pressure region from a gas volume held in the tubular damper housing, and the bottom valve element divides the tubular damper housing into a low-pressure working chamber and a high-pressure working chamber, which is acted upon by means of the working piston, and an inlet opening of the damping valve element is fluidly connected to the high-pressure working chamber, and an outlet opening of the damping valve element is fluidly connected to the low-pressure region, such that the damping valve element is connected in parallel with the working piston. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic illustration of a vibration damper according to one example of the present disclosure. FIG. 2 is a vibration damper according to FIG. 1 shown in the rebound stage and with a damping valve element in the closed position. FIG. 3 is a vibration damper according to FIG. 1 shown in the rebound stage and with a damping valve element in the open position. FIG. 4 is a vibration damper according to FIG. 1 shown in the compression stage and with a damping valve element in the closed position. FIG. 5 is a vibration damper according to FIG. 1 shown in the compression stage and with a damping valve element in the closed position. FIG. 6 is an alternative embodiment of the damping valve element. DETAILED DESCRIPTION Although certain example methods and apparatus have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents. Moreover, those having ordinary skill in the art will understand that reciting “a” element or “an” element in the appended claims does not restrict those claims to articles, apparatuses, systems, methods, or the like having only one of that element, even where other elements in the same claim or different claims are preceded by “at least one” or similar language. Similarly, it should be understood that the steps of any method claims need not necessarily be performed in the order in which they are recited, unless so required by the context of the claims. In addition, all references to one skilled in the art shall be understood to refer to one having ordinary skill in