ADJUSTABLE VIBRATION DAMPER

Abstract

An adjustable vibration damper has at least one adjustable damping valve, a piston at a piston rod that divides a cylinder into a work chamber on the piston rod side and a work chamber on the side remote of the piston rod. A hydraulic device is connected via a first line to the at least one adjustable damping valve connected to one of the work chambers and via a second line at least indirectly to the other working chamber.

Claims

1.-10. (canceled)

11. An adjustable vibration damper comprising: a cylinder; at least one adjustable damping valve; a piston rod; a piston at the piston rod that divides the cylinder into two work chambers, a first work chamber on a piston rod side and a second work chamber on a side remote of the piston rod; a first line; a second line; and a hydraulic device connected via the first line to the at least one adjustable damping valve, which is connected to one of the two work chambers, and via the second line at least indirectly to the other of the two work chambers.

12. The adjustable vibration damper according to claim 11, wherein the hydraulic device is connected via the first line to a first adjustable damping valve of the at least one adjustable damping valve and via a second line to a second adjustable damping valve of the at least one adjustable damping valve.

13. The adjustable vibration damper according to claim 11, further comprising: a pipe connection piece having at least one connection opening for the hydraulic device and configured to connect the at least one adjustable damping valve to the cylinder.

14. The adjustable vibration damper according to claim 13, wherein the pipe connection piece is formed of multiple portions, wherein a first pipe portion is configured as a connection to the cylinder and a second pipe portion is configured as an adapter comprising the at least one connection opening.

15. The adjustable vibration damper according to claim 13, wherein the at least one adjustable damping valve is connected to one of the two work chambers via a fluid connection, and wherein the fluid connection comprises an intermediate tube connected to the at least one adjustable damping valve via a connection sleeve which is connected to the at least one connection opening.

16. The adjustable vibration damper according to claim 15, further comprising: an annular channel configured to connect the connection sleeve to the at least one connection opening.

17. The adjustable vibration damper according to claim 13, wherein the at least one connection opening is constructed as a portion of a radial channel.

18. The adjustable vibration damper according to claim 13, wherein one of the at least one connection opening has a greater axial distance from the cylinder than an other of the at least one connection opening.

19. The adjustable vibration damper according to claim 13, wherein the at least one connection opening is arranged to be offset in circumferential direction relative to an electric connection for the at least one adjustable damping valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention will be described in more detail referring to the following description of the figures.

[0019] FIG. 1 is a diagram of an adjustable vibration damper;

[0020] FIGS. 2 and 3 are sectional view of a vibration damper; and

[0021] FIG. 4 is a detail of the vibration damper according to FIGS. 2 and 3.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0022] FIG. 1 shows the equivalent diagram of an adjustable vibration damper 1 with adjustable damping valves 3; 5, respectively, for a movement direction of a piston 7 at a piston rod 9. Reference is made to DE 10 2015 2000 348 A1 as regards the constructional layout of the adjustable damping valves. The two adjustable damping valves 3; 5 are connected to a work chamber 15; 17, respectively, via a fluid connection 11; 13.

[0023] The piston 7 divides a cylinder 19 which is completely filled with damping medium into a work chamber 15 on the piston rod side and a work chamber 17 remote of the piston rod. A compensation space 21 compensates for the damping medium volume displaced by the piston rod 7.

[0024] Hydraulically parallel to the two damping valves 3; 5, the vibration damper 1 has a hydraulic device 23 comprising a pump 25 with two conveying directions and a drive motor 27, preferably an electric motor. The hydraulic device 23 is likewise connected to the two work chambers 15; 17 via two lines 29; 31 and accordingly allows damping medium to be circulated between work chambers 15; 17 to exert additional actuating forces on the piston rod 9.

[0025] FIGS. 2 and 3 show a vibration damper 1 according to the equivalent diagram of FIG. 1. In addition to the cylinder 19, the vibration damper 1 has an intermediate tube 33; 35 connected to one of the work chambers 15; 17 and one of the adjustable damping valves 3; 5. For this purpose, a connection opening 37 that, with the first fluid connection 11, leads to the first adjustable damper 3 is formed in the work chamber 15 on the piston rod side for the first intermediate tube 33. The work chamber 17 remote of the piston rod also has a connection opening 39 of this kind to the second fluid connection 13. Fluid connections 11; 13 are formed, respectively, by the intermediate tubes 33; 35 and the portions of cylinder 19 enclosed by the intermediate tubes 33; 35.

[0026] The two adjustable damping valves 3; 5 are only shown as equivalent diagrams. However, to make it easier to distinguish between them a hydraulic connection 41; 43 is shown, which forms the connection between the fluid connection and the connected adjustable damping valve.

[0027] Further, it can be seen from FIG. 2 that the hydraulic device 23 is connected to the adjustable damping valve 3 of the work chamber 15 on the piston rod side via the first line 29 and is connected to the adjustable damping valve of the work chamber 17 remote of the piston rod via the second line 31. In this specific example, the two work chambers 15; 17 have a fluid connection 11; 13 to an adjustable damping valve 3; 5, respectively, and the hydraulic device 23 is connected via its lines 29; 31, respectively, to one of the damping valves 3; 5.

[0028] The compensation space 21 extends completely concentric to cylinder 19 and is radially limited by an outer reservoir tube. The reservoir tube serves as a support for the two adjustable damping valves 3; 5 and possibly for the hydraulic device 23.

[0029] FIG. 4 shows a detail from FIG. 2 from which it is apparent that the adjustable damping valves 3; 5 are connected to the cylinder 19 via a pipe connection piece 45. The pipe connection piece 45 is part of an outer reservoir tube 47 and is welded to the latter. Optionally, the pipe connection piece 47 can also be formed integral with the reservoir tube 47. The pipe connection piece 47 has a connection opening for the hydraulic device 23. Two preferred embodiments are shown in FIG. 4.

[0030] The pipe connection piece 45 for the damping valve 5 connected to the work chamber 17 remote of the piston rod, for example, is formed of multiple parts. A first pipe portion 53 forms the connection to the cylinder 19 and is fixedly connected to the reservoir tube 47. A further pipe portion 55 is arranged in this pipe portion 53 and forms an adapter with the connection opening 51. The further pipe portion 55 can be oriented rotationally in any desired manner with respect to the pipe portion 53 on the reservoir tube side.

[0031] For example, the adjustable damping valve 3 of the work chamber 15 on the piston rod side is likewise connected via fluid connection 11 to work chamber 15, and the fluid connection is formed by the intermediate tube 33, which is connected to the adjustable damping valve 3 via a connection sleeve 57 connected to the connection opening 49. The connection sleeve 57 provides for an installation space for arranging the connection opening 49. In this construction mode, the connection sleeve 57 can also have any orientation in circumferential direction, since the connection sleeve 57 is connected to the connection opening 49 via an annular channel 59. The connection sleeve 57 can also be a seat surface for a check valve 63; 65, which is usable in a particularly meaningful manner when the two adjustable damping valves 3; 5 are connected to a common compensation space 21. The check valves 63; 65 always open when the work chamber 15; 17 associated with the damping valve 3; 5 becomes larger as a result of a piston movement. Damping medium can then flow out of the compensation space 31 in the work chamber 15; 17 via the check valve 15; 17. When there is incident flow from the work chamber 15; 17 into the fluid connection 11; 13, the check valve closes and the damping medium flows on into a space between the check valve 63; 65 and inlet opening 67 into the adjustable damping valve 3; 5. The flow from the damping valve 3; 5 into the compensation space of the pipe connection piece 45 takes place radially offset to the inlet opening 67.

[0032] In both embodiment forms, the connection opening 49; 51 is part of a radial channel 69 which the distance between an outer lateral surface of the pipe connection piece 45 and of the hydraulic connection 41; 43 of the fluid connection to the adjustable damping valve. The two variants are shown in combination in this view. In principle, however, one of the two construction forms could also be provided for both connection openings 49; 51.

[0033] FIG. 4 illustrates that one of the connection openings 49; 51 can have a greater axial distance from cylinder 19 than the other connection opening. The lines 29; 31 can accordingly be installed in different planes with respect to the reservoir tube 47.

[0034] Lines 29; 31 run in an installation space, which will possibly also be needed for lines 71; 51 of an electric connection 75; 77 of the adjustable damping valves. The electric connection 75; 77 serves, inter alia, for the power supply of a coil, not shown. It will likewise be apparent from FIG. 4 that the connection opening 49; 51 can be arranged to be offset in circumferential direction relative to an electric connection 75; 77 for the adjustable damping valve 3; 5.

[0035] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design