Patent Application
20250020185
This application claims priority to German Patent Application No. 10 2023 118 618.3, filed Jul. 13, 2023, the content of such application being incorporated by reference herein in its entirety.
The invention relates to a vibration damper having a damper piston, which can be moved back and forth in a main pipe with hydraulic medium in an axial direction relative to the main pipe, wherein the main pipe is arranged in a container pipe, wherein an intermediate pipe is arranged between the main pipe and the container pipe, wherein the main pipe, the intermediate pipe and the container pipe are arranged coaxially in a three-pipe damper, wherein the damper piston is attached to an end of a piston rod, wherein the three-pipe damper is equipped with a hydraulic end position damper and, at its end facing away from the piston rod, has a central valve block with two damper valve devices.
The German publication DE 10 2019 104 714 A1, which is incorporated by reference herein, discloses a motor vehicle shock absorber with an air spring unit, in which work spaces filled with compressed air surround valve receptacles. The German publication DE 10 2013 212 974 A1, which is incorporated by reference herein, discloses a motor vehicle shock absorber with an air spring unit, in which a work space surrounds valve receptacles. The German publication DE 10 2013 113 737 A1, which is incorporated by reference herein, discloses a motor vehicle shock absorber having an air spring unit, in which switching valves are arranged almost entirely within switching volumes of the chambers defining the air spring unit. The German publication DE 197 53 637 A1, which is incorporated by reference herein, discloses a motor vehicle shock absorber with an air spring unit, in which a residual pressure valve is arranged within an air spring piston. The German publication DE 100 14 467 C1, which is incorporated by reference herein, discloses a motor vehicle shock absorber with an air spring unit, in which an unwinding piston surrounds a housing of a variable damper device.
Described herein is a vibration damper having a damper piston, which can be moved back and forth in a main pipe with hydraulic medium in an axial direction relative to the main pipe, wherein the main pipe is arranged in a container pipe, wherein an intermediate pipe is arranged between the main pipe and the container pipe, wherein the main pipe, the intermediate pipe and the container pipe are arranged coaxially in a three-pipe damper, wherein the damper piston is attached to an end of a piston rod, wherein the three-pipe damper is equipped with a hydraulic end position damper and, at its end facing away from the piston rod, has a central valve block with two damper valve devices, in that the central valve block is partially surrounded by an air spring, which comprises an air spring housing that surrounds the central valve block, wherein the three-pipe damper has a gas balance volume at its piston rod end, which is arranged in an annular space between the intermediate pipe and the container pipe. On the one hand, this provides a vibration damper or shock absorber that enables very comfortable operation of a motor vehicle equipped with the vibration damper or shock absorber both at high frequencies and low frequencies. This provides an elegant solution to the installation space conflict resulting from the combination of the gas balance volume and the air spring on the three-pipe damper. At the piston end of the three-pipe damper, the annular space between the intermediate pipe and the container pipe is effectively used to accommodate the gas balance volume. The gas balance volume is advantageously illustrated with a gas bag containing a gas, such as air. The gas bag is formed from a gas-tight flexible material. The gas bag is located between the intermediate pipe and the container pipe and is connected with a bayonet valve. During operation of the vibration damper, the gas bag provides separation between oil and gas. Moreover, the gas bag prevents the oil from foaming. At the end of the three-pipe damper facing away from the piston rod, a sufficiently large air volume may be provided particularly advantageously for the air spring by partially surrounding the central valve block with the air spring. The resulting disadvantage with regard to the connection of hydraulic lines to the central valve block is deliberately accepted. The two damper valve devices advantageously in each case comprise a check valve. One of the damper valve devices also comprises a rebound valve. The other damper valve device advantageously comprises a pressure stage valve in addition to the check valve. The air spring housing surrounding the central valve block allows the air spring chamber represented by the air spring to be maximized very effectively. This results in a significant package advantage. Moreover, the air spring may have a softer design, as more volume may be provided in the air spring housing than with conventional shock absorbers.
A preferred example embodiment of the vibration damper is characterized in that the air spring housing comprises a housing upper part that surrounds the container pipe on the outside. The housing upper part advantageously surrounds a lower end region of the container pipe. The multi-part design of the air spring housing simplifies both the manufacture and assembly of the air spring.
A further preferred example embodiment of the vibration damper is characterized in that the three-pipe damper comprises a bellows that surrounds the outside of the container pipe above the housing upper part. The bellows advantageously serves to enable operational movements of the vibration damper in the installed state and during operation.
A further preferred example embodiment of the vibration damper is characterized in that the housing upper part is polygonal on the outside. The available installation space can thus be exploited optimally. The air spring housing with the housing upper part and the housing lower part is advantageously manufactured as an injection molded part from a suitable plastic material.
A further preferred example embodiment of the vibration damper is characterized in that the air spring housing comprises a housing lower part that surrounds the container pipe on the outside. The housing lower part is preferably detachable, for example by a snap connection or a latch connection, connected to the housing upper part of the air spring housing. This further simplifies the manufacture and assembly of the air spring housing.
A further preferred example embodiment of the vibration damper is characterized in that the housing lower part is polygonal on the outside. This also proved advantageous with regard to the use of the available installation space.
A further preferred example embodiment of the vibration damper is characterized in that the housing lower part has at least one recess for a damper valve block on the central valve block. One end of the damper valve block preferably protrudes outwards beyond the housing lower part. This ensures accessibility of the damper valve block from the outside.
A further preferred example embodiment of the vibration damper is characterized in that the housing lower part has at least one recess for a connection valve block on the central valve block. This allows hydraulic lines to be connected to the central valve block even when the air spring is mounted.
The invention further relates to a motor vehicle having an active chassis comprising at least one previously described vibration damper. The motor vehicle with the active chassis advantageously comprises four wheels in each case associated with a previously described vibration damper.
The invention further relates to a container pipe, an intermediate pipe, a main pipe, a central valve block, an air spring housing, in particular a housing upper part and/or a housing lower part, for a previously described vibration damper. The aforementioned parts can be purchased separately.
Further advantages, features, and details of the invention arise from the following description, in which various example embodiments of the invention are described in detail with reference to the drawings. The FIGs. show:
The suspension strut 10 with the vibration damper 1, which is designed as a three-pipe damper 2, is part of a hydraulic system that serves in a motor vehicle to represent an active damping control during operation of the motor vehicle. The motor vehicle preferably comprises four wheels, each of which is associated with a vibration damper 1 configured as a three-pipe damper 2. The three-pipe damper or vibration damper is also referred to as a damper for short. The hydraulic damper represents a shock absorber in an active chassis of a motor vehicle.
The three-pipe damper 2 is operated with a hydraulic medium. The hydraulic medium is preferably a hydraulic fluid, which will also be referred to as a hydraulic oil or abbreviated as “oil”. In addition to a hydraulic damper volume, the hydraulic damper comprises a gas balance volume 21.
The active damping control comprises a hydraulic actuator apparatus, which is hydraulically connected to the dampers via the hydraulic lines. The hydraulic actuator apparatus in the active chassis of the motor vehicle is used to stimulate or drive the hydraulic dampers in a targeted manner. To this end, the hydraulic actuator apparatus advantageously comprises a separate hydraulic pump for each damper. Two hydraulic pumps can be combined together in each axle of the motor vehicle into one motor-pump unit. The hydraulic pumps associated with the respective axle are advantageously controllable separately via a common control unit.
In the main pipe 3 of the three-pipe damper 2, a damper piston 6 in
The main pipe 3, the intermediate pipe 4 and the container pipe 5 are arranged coaxially and provided with interstices in the radial direction. An annular space between the main pipe 3 and the intermediate pipe 4 allows the hydraulic medium to pass through, in particular a return line of the hydraulic medium downwards, without extra hydraulic lines. An annular space between the intermediate pipe 4 and the container pipe 5 advantageously serves to receive the gas balance volume 21.
The gas balance volume 21 is illustrated with a gas bag 22, which is received at a piston rod end of the three-pipe damper 2, i.e. in
At its lower end, in
Furthermore, the damper valve device 8 comprises a rebound valve that is hydraulically connected via an annular gap 71 to the annular space between the main pipe 3 and the intermediate pipe 4. In
The central valve block 12 comprises a base block 13, which is configured as a full pipe body, for example. The outside of the base block 13 has the shape of a straight circular cylindrical shell, for example. For example, the base block 13 is configured as a milling part and attached to the lower end of the three-pipe damper 2.
The center valve block 12 further comprises two damper valve blocks 16, 17 that are substantially the design of straight circular cylinders. The two damper valve blocks 16, 17 may be integrally connected to the base block 13. The damper valve blocks 16, 17 serve to receive and/or represent the damper valve devices 8 and 9. The two damper valve blocks 16, 17 are arranged coaxially to each other and transversely to the longitudinal axis of the three-pipe damper 2.
The center valve block 12 further comprises a connection valve block 18. The connection valve block 18 is configured as a separate component and is attached to the base block 13. For example, two screws 73, 74 serve to attach the connection valve block 18 to the base block 13 of the central valve block 12.
The design of the connection valve block 18 as a separate component has the advantage, among other things, that a package-dependent design of the vibration damper is possible with relatively little design effort, in particular when installed in different motor vehicle variants or motor vehicle derivatives. Moreover, the separate connection valve block 18 can be designed and arranged on the base block 13, such that specific crash requirements for a motor vehicle equipped with the vibration damper 1 can be ideally met.
With regard to the package-dependent design of the connection valve block 18, the positioning of hydraulic connections 23, 24 is particularly important. The hydraulic connections 23, 24 at the connection valve block 18 serve to connect hydraulic lines 27, 28, as can be seen in particular in
The motor vehicle 30 indicated in
An additional design effort results from the fact that the vibration damper 1 configured as a three-pipe damper 2 is combined with an air spring 20, as can be seen in
The air spring 20 comprises an air spring housing 50 having a housing upper part 51 and a housing bottom part 52. The air spring housing 50 comprises a single, relatively large air volume. The air spring housing 50 extends around the lower end of the three-pipe damper 2 with the central valve block 12. In the axial direction, the air spring housing 50 is arranged between a bellows 58 and the central valve block 12, which is partially surrounded by the housing bottom 52.
The air spring housing 50, with its housing lower part 52, is supported by an axial support ring 15, which is attached to the lower end of the three-pipe damper 2. The axial support ring 15 is combined with an adapter body 14, which allows the air spring housing 50 to be attached on the outside to the container pipe 5 of the three-pipe damper 2. The air spring housing 50 is attached to the adapter body 14, for example by means of a snap connection or a latch connection.
In
It can be seen in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 118 618.3 | Jul 2023 | DE | national |
