CN115585209A

CN115585209A - Vibration damper with adjustable damping valve device

Info

Publication number: CN115585209A
Application number: CN202210593271.7A
Authority: CN
Inventors: A·弗斯特
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2021-07-06
Filing date: 2022-05-27
Publication date: 2023-01-10
Also published as: DE102021207061A1; DE102021207061B4

Abstract

The invention relates to a vibration damper having an adjustable damping valve device, comprising an annular compensation chamber which is partially filled with a damping medium, wherein an outflow channel of the damping valve device opens into a damping medium reservoir of the compensation chamber, and a deflecting element for guiding the flow of the damping medium is arranged spatially between the outflow channel and a damping medium level of the damping medium reservoir, wherein the deflecting element defines a circumferential groove which redirects the damping medium discharged from the outflow channel in the direction of the damping valve device by means of a web which points in the direction of the damping valve device.

Description

Vibration damper with adjustable damping valve device

Technical Field

The invention relates to a vibration damper with an adjustable damping valve device.

Background

A generic type of vibration damper is known from DE10 2015 213 A1, in which the outflow channel of the adjustable damping valve device opens into an annular compensation chamber in the vibration damper. In particular, the outflow channel of the adjustable damping valve device is placed as close as possible to the bottom of the compensation chamber in order to achieve a greater distance from the damping medium level in the compensation chamber. Thereby minimizing foam generation of the damping medium upon discharge from the damping valve device. In DE10 2015 213 A1 a deflecting element is used which is held by the connecting branch of the intermediate pipe and positioned relative to the outlet channel. The deflection element has a pot-like basic shape with a circumferential edge which points in the direction of the inner wall of the outer cylinder (which also defines the compensation chamber). The damping medium discharged from the damping valve device is present at the bottom of the deflection element and is deflected by the circumferential edge in the direction of the inner wall. Thereby, the direct flow path to the damping medium level is at least partially blocked.

The deflecting element is made of plastic or rubber. Due to the position within the vibration damper, the deflection element is subjected to more severe wear due to the damping medium flowing out of the damping valve device via the outflow channel.

US 10 968 975 B2 likewise describes a vibration damper with an adjustable damping valve arrangement and a deflection element in a compensation chamber. Unlike DE10 2015 213 A1, the deflecting element has a plurality of spaced-apart ring elements which point in the direction of the inner wall and thus define the throttle gap. The deflection element is supported on the intermediate tube and need not be rotationally oriented relative to the damper valve arrangement. In this embodiment, too, the damping medium is deflected by the deflection element only to the maximum extent in the direction of the inner wall of the outer cylinder.

Disclosure of Invention

The object of the present invention is to find a simple and universally usable solution for a deflection element.

This object is achieved in that the deflector element defines a circumferential groove which, by means of a web pointing in the direction of the damping valve device, redirects the damping medium emerging from the outflow channel in the direction of the damping valve device.

The groove shape of the deflection element provides the following advantages: on the one hand, it is not necessary to orient the deflection element rotationally relative to the damping valve device, and on the other hand, the deflection element generates a counter flow relative to the volume of damping medium discharged from the damping valve device into the compensation chamber. This reverse flow reduces the tendency for foam to form in the compensation chamber of the vibration damper.

In a further advantageous embodiment, the deflection element is fastened to the cylinder of the vibration damper. For example, a so-called intermediate pipe, which forms a fluid connection between the working chamber and the damping valve device or an outer cylinder, i.e. an inner wall, can be used as a cylinder.

According to the dependent claims, the retaining surface of the cylinder forms the boundary of the groove for fastening the deflection element. The structure of the deflection element is thereby simplified, since at least one second web defining a groove does not have to be implemented at the deflection element.

Preferably, the retaining surface of the cylinder projects radially with respect to the remaining surface of the cylinder, so that, for example, it is not necessary to manufacture the entire cylinder with the precision required for achieving the clamping function and the diameter accuracy required for this purpose.

Optionally, the deflector element may have at least one venting opening which extends hydraulically parallel to an annular gap between the inner wall of the outer cylinder and the web of the deflector element. Even with the most careful assembly and a high quality of the damping medium, the damping medium has a certain amount of gas fraction which can be released from the damping valve device when the damping medium is discharged. The gas portion can rise controllably to the damping medium level through the vent opening.

In a further embodiment, the at least one exhaust opening extends obliquely to the longitudinal axis of the deflector element. The following are mentioned here: the foam generation is minimized by extending the path of the gaseous inclusions to the level of the dampening medium.

Furthermore, it can be proposed that: the groove and the guide sleeve of the deflection element are connected to one another by means of a transitional circular arc, so that the deflection element is fastened. The deflecting element is preferably manufactured as a curved plate. In this case, a sharp bend between the two functional regions is not desirable. The rounding results in a very practical surface area which simplifies the mounting of the deflection element on the holding surface.

A further measure for increasing the deflection function of the deflection element consists in that the bottom of the groove of the deflection element is rounded off in the flow direction of the damping medium, starting from the outflow channel. Thus, there is a relatively large surface area for a continuous deflection function.

Drawings

The invention is explained in detail below with the aid of the following description of the figures.

In the drawings:

FIG. 1 shows a cross-sectional illustration through a vibration damper with an adjustable damper valve arrangement;

fig. 2 shows a detail illustration in the region of the deflection element according to fig. 1;

fig. 3 and 4 show the deflection element according to fig. 2 as a part;

fig. 5 shows an alternative embodiment of the deflection element.

Detailed Description

Fig. 1 shows an adjustable damping valve device 3 in each working direction; 5, vibration damper 1. In the inner cylinder 7, the piston rod 9 is guided axially movably with a piston 11. The piston 11 divides the inner cylinder 7 into a working chamber on the piston rod side and a working chamber 13 remote from the piston rod; 15. the entire inner cylinder 7 is filled with hydraulic damping medium.

The outer cylinder 17 completely surrounds the inner cylinder 7. The piston rod guide 19 closes the inner and outer cylinders 7 at the end sides; 17.

at the end opposite the piston rod guide 19, the bottom 21 forms a closure for the outer cylinder 17. On the bottom 21, a bottom valve body 23 is supported, which in turn delimits the working chamber 15 in the inner cylinder 7, remote from the piston rod.

An annular compensation chamber 25 extends between the inner cylinder 7 and the outer cylinder 17. The damping medium reservoir 27 compensates the volume of the piston rod 9 retracted and extended into the inner cylinder 7 in the compensation chamber 25. Above the damping medium level 29 of the damping medium reservoir there is a gas filling 31, which may have an ambient pressure, but may also have a system pressure above it.

The first damping valve device 3 is connected to the working chamber 15 remote from the piston rod by means of a first intermediate pipe 33. The first intermediate pipe 33 is guided on the outer surface of the inner cylinder 7 and has a pipe connection 35 which engages into the damping valve device 3. The specific structural design of the damping valve device 3 is not critical to the invention, and reference is made to the design of the damping valve device according to DE10 2013 218 658 A1, the contents of which are part of the description of the present figure.

A first connecting opening 37 is embodied in the inner cylinder 7 close to the bottom, which connects the working chamber 15 remote from the piston rod to a first fluid portion 39 which leads to the damping valve device 3. The damping medium which is forced out of the working chamber 15 remote from the piston rod flows into the first damping valve device 3 during the retraction movement of the piston rod 9 and via the outflow channel 40 into the damping medium reservoir 27 in the compensation chamber 25. When the pressure is above the peak pressure, a pressure relief valve 41 in the bottom valve body 23 can be opened and the bypass to the compensation chamber 25 released.

The inner cylinder 7 also carries a second intermediate pipe 43, which forms a second fluid connection 45 with the inner cylinder 7 between a second connection opening 47 in the piston-rod-side working chamber 13 above the maximum extension position of the piston 11 and a second damping valve device 5 for damping a piston-rod extension movement.

As can be seen immediately from fig. 1, the distance between the outflow channel 40 of the first damping valve device 3 and the damping medium level 29 is significantly greater than the distance between the outflow channel 49 of the second damping valve device 5 and the damping medium level 29. The first damping valve device 3 is therefore not critical with regard to the generation of foam by the damping medium in the compensation chamber 25.

In connection with the second damping valve device 5, a deflection element 51 is therefore used in the compensation chamber 25 or in the damping medium reservoir 27, which deflection element stabilizes the damping medium entering the compensation chamber 23 from the outflow channel 49 by deflection and thus suppresses the formation of foam.

As can be seen in the enlarged illustration according to fig. 2, the deflecting element 51 defines a circumferential groove 53 which, by means of a web 55 pointing in the direction of the damping valve device 5, redirects the damping medium discharged from the outflow channel 49 in the direction of the second damping valve device 5.

The deflection element 51 is fastened to the cylinder of the vibration damper 1, in this case to the second intermediate tube 43. The retaining surface 57 for fastening the intermediate tube 43 of the deflection element 51 forms the boundary of the groove 53. The deflection element 51 can be connected to the intermediate tube 43, for example, by means of a press-fit or material-fit connection. For simple assembly of the deflection element 51, the retaining surface 57 of the intermediate tube 43 projects radially with respect to the remaining surface of the intermediate tube 43. As a result, the intermediate tube 43 only has to be machined more precisely in the region of the holding surface 57.

The webs 55 of the deflecting element 51 form an annular gap 59 with the inner wall of the outer cylinder 17, which allows an unrestricted throughflow of the damping medium.

In fig. 3 and 4, a deflection element 51 is shown as a part. The deflection element has a guide sleeve 61, the inner diameter of which is adapted to the size of the retaining surface 57 at the intermediate tube 43. The transition arc 63 is connected to the base 65 of the groove 53, which in turn has a circumferential web 55 on the outside. Overall, there are stepped curved plate parts of relatively simple design which have no recesses and can therefore be produced simply.

The deflector element 51 has at least one air outlet opening 67, which extends hydraulically parallel to the annular gap 59 between the inner wall of the outer cylinder 17 and the web 55 of the deflector element 51. The size of the exhaust opening 67 is relatively small, e.g. 1mm ² So that the flow along the base 65 and the rearward facing web 55 obtains a certain swirl and thus a longer flow path is implemented in the damping medium reservoir 27.

Fig. 4 shows that the at least one exhaust opening 67 extends obliquely with respect to the longitudinal axis 71 of the deflecting element 51. The at least one air outlet opening 67 is preferably located at the transition arc 63 between the groove 53 and the guide sleeve 61 of the deflector element 51 and thus at a higher flow point in the groove 53, which point originates from the outflow channel 49. Thereby, the inlet opening of the exhaust opening 67 is oriented close to the intermediate pipe 43.

The embodiment of the deflecting element 51 according to fig. 5 corresponds to many details of the embodiment according to fig. 3 and 4. The difference lies in that: the bottom 65 of the groove 53 of the deflection element is rounded in the flow direction of the damping medium from the outflow channel 49. Furthermore, the outlet opening of the at least one exhaust opening 67 is oriented in the direction of the guide sleeve 61, so that the guide sleeve 61 forms an impact surface 69 for gaseous inclusions and a small amount of discharged damping medium flowing through the exhaust opening 67.

List of reference numerals

1. Vibration damper

3. Damping valve device

5. Damping valve device

7. Inner cylinder body

9. Piston rod

11. Piston

13. Piston-rod-side working chamber

15. Working chamber far away from piston rod

17. Outer cylinder body

19. Piston rod guide

21. Bottom part

23. Bottom valve body

25. Compensation chamber

27. Damping medium reservoir

29. Damping medium level

31. Gas filling part

33. First intermediate pipe

35. Pipe joint

37. First connecting opening

39. First fluid connection

40. Outflow channel

41. Pressure relief valve

43. Second intermediate pipe

45. Second fluid connection

47. Second connecting opening

49. Outflow channel

51. Deflection element

53. Groove

55. Tab

57. Holding surface

59. Annular gap

61. Guide sleeve

63. Transition arc part

65. Bottom of the trench

67. Exhaust opening

69. Impact surface

71. Longitudinal axis

Claims

1. A vibration damper (1) having an adjustable damping valve device (5), comprising an annular compensation chamber (25) which is partially filled with a damping medium, wherein an outflow channel (49) of the damping valve device (5) opens into a damping medium reservoir (27) of the compensation chamber (25), and a deflecting element (51) for guiding a flow of the damping medium is spatially arranged between the outflow channel (49) and a damping medium level (29) of the damping medium reservoir (27), characterized in that the deflecting element (51) defines a circumferential groove (53) which, by means of a web (55) pointing in the direction of the damping valve device, redirects the damping medium which is discharged from the outflow channel (49) in the direction of the damping valve device (5).

2. The vibration damper according to claim 1, characterized in that the deflecting element is fastened on a cylinder (43) of the vibration damper (1).

3. The vibration damper according to claim 2, characterized in that a retaining surface (57) of the cylinder (43) for fastening the deflecting element (51) constitutes a boundary of the groove (53).

4. A vibration damper according to claim 3, characterized in that the retaining surface (57) of the cylinder (43) protrudes radially with respect to the remaining surface of the cylinder (43).

5. The vibration damper according to any of claims 1 to 4, characterized in that the deflector element (51) has at least one exhaust opening (67) which extends hydraulically parallel to an annular gap (59) between the inner wall of the outer cylinder (17) and the tab (55) of the deflector element (51).

6. The vibration damper according to claim 5, characterized in that the at least one exhaust opening (67) extends obliquely with respect to a longitudinal axis (71) of the deflecting element (51).

7. The vibration damper according to any of claims 1 to 4, characterized in that the groove (53) of the deflecting element (51) and the guide sleeve (61) are connected to each other by means of a transitional circular arc (63) in order to achieve a fastening of the deflecting element.

8. The vibration damper according to any of claims 1 to 4, characterized in that the groove (53) bottom (65) of the deflecting element (51) is rounded in the flow direction of the damping medium from the outflow channel (49).