Damper valve device with progressive damping force characteristic

Abstract

Damper valve device (1) for a damper (3), comprising a throttle point (37) which cooperates with a valve element (35), which can be shifted from a through-flow state into a throttled state depending on the flow rate of a damping medium in the throttle point (37), wherein the valve element (35) as a ring element of variable diameter moves in a ring groove (33) of a valve carrier (29) in a closing direction with increasing flow rate of the damping medium, wherein the valve carrier (29) has a valve element (35A, 35B) in the ring groove (33) for each flow direction through the damper valve device (1), respectively, and the ring groove (33) is configured to have two pressure chambers (55A, 55B) which each have at least one inflow opening (57A, 57B) and at least one outflow opening (59, 59A, 59B), wherein the effective inflow opening has a correspondingly greater cross section than the effective outflow opening.

Description

TECHNICAL FIELD

[0001] The invention relates to a damping valve arrangement with a progressive damping force characteristic. BACKGROUND

[0002] The patent document DE 10 2016 210 790 A1 describes a damping valve arrangement for a shock absorber, which damping valve arrangement comprises a first damping valve which transitions into a throughflow operating state with increasing flow rate of the damping medium in a first operating range. The first damping valve is formed, for example, by a piston valve or a bottom valve of the shock absorber. A second operating range of the shock absorber with a progressive damping force characteristic is influenced by a throttle site which acts in conjunction with a valve body which transitions from a throughflow state into a throttling state depending on the flow rate in the throttle site, independently of the stroke position of the piston rod of the shock absorber, wherein the valve body moves in the closing direction with increasing flow rate of the damping medium. An additional damping force is thereby generated which makes it possible to dispense with a conventional pull stop or push stop which is only active at one end position of the piston rod.

[0003] The throttle site and the damping valve are arranged in hydraulic series, wherein the valve body is configured as a diameter-variable annular element which performs a radial closing movement in the direction of the flow guide surface, wherein a defined minimum throughflow cross section is maintained.

[0004] The patent document DE 10 2019 212 966 A1 proposes that the diameter-variable annular element is additionally supported by a pressure in a pressure chamber formed in the annular groove. The function of the pressure chamber is particularly effective if the cross section of the inflow opening of the pressure chamber is greater than the outflow opening. With regard to the damping characteristic of the shock absorber, it is meaningful to use two throttle sites, each for one working direction of the shock absorber.

[0005] However, it is meaningful in terms of costs to limit the damping valve arrangement to one throttle site which is optimally effective for both flow directions. SUMMARY

[0006] It is an object of the invention to solve the problems known from the prior art.

[0007] This object is achieved in that the valve carrier has a valve element for each flow direction of the damping valve arrangement in the annular groove, and the annular groove is configured with two pressure chambers which each have at least one inflow opening and at least one outflow opening, wherein the effective inflow opening has a greater cross section than the effective outflow opening.

[0008] By spatially combining the valve elements in the annular groove, a significant construction space advantage can be achieved. Furthermore, the structure of the shock absorber equipped with such a damping valve arrangement is simplified since there is only one placement site for both valve elements.

[0009] In a further advantageous design, the two pressure chambers are separated from one another by means of a partition wall. The construction type with two pressure chambers makes it possible to adjust the pressure chamber size and thus also indirectly to adjust the pressure acting on the valve elements in the closing direction.

[0010] In a first embodiment, the partition wall is formed by a disk connected to the valve carrier. The disk itself is a very simple component.

[0011] By arranging the partition disk between the two shells of the valve carrier, the fastening of the disk, and thus of the partition wall, can thereby be achieved very easily and still hydraulically sealed.

[0012] Alternatively, it can be provided that the partition wall is formed by the two valve elements by making them slide directly on one another.

[0013] In a further advantageous design, the partition wall has a flow-out opening. The advantage is a simple flow guidance of the damping medium in the valve carrier.

[0014] It can also be provided that the valve elements have a flow-out opening, wherein the valve element standing still when flowing through the damping valve arrangement determines the flow-out cross section.

[0015] The flow-out opening in the valve elements can be configured as an axial channel independently of the construction type of the partition wall. A minimum flow length in the valve carrier is thereby obtained.

[0016] It can also be provided that the flow-out opening is configured as a radial channel. This construction type simplifies the construction type of the partition wall in particular.

[0017] In order to avoid an undefined leakage, the valve elements are preloaded onto the partition wall with a cover side. BRIEF DESCRIPTION OF DRAWINGS

[0018] The application is further explained with reference to the subsequent drawing description. In which:

[0019] Figure 1 A cross section of a shock absorber in the region of the damping valve arrangement is shown;

[0020] Figure 2 A detailed illustration of the damping valve arrangement according to Figure 1 is shown; and

[0021] Figure 3 and Figure 4 Alternative variants of the embodiment of the damping valve arrangement are shown. DETAILED DESCRIPTION

[0022] Figure 1 A damping valve device 1 for a shock absorber 3 of arbitrary construction type is shown, the shock absorber being shown only partially. The shock absorber 3 comprises, in addition to the damping valve device 1, a first damping valve 5 having a damping valve body configured as a piston 7, which is fastened on a piston rod 9.

[0023] The damping valve body 7 divides a cylinder 11 of the shock absorber into a working chamber 13 on the piston rod side and a working chamber 15 remote from the piston rod, both of which are filled with a damping medium. Through-paths 17, 19 for the respective flow-through direction are configured in the damping valve body 7 on different graduation circles. The design of the through-paths 17, 19 is merely exemplary. The outlet side of the through-paths 17, 19 is at least partially covered by at least one valve disc 21, 23.

[0024] Furthermore, the shock absorber has a pull stop 25, which abuts against a cylinder-side stop face, for example a cylinder-side stop face of a piston rod guide 27, from a defined displacement movement of the piston rod 9.

[0025] The pull stop 25 comprises a valve carrier 29, which is fixed directly at the piston rod by a form-fit connection. An annular elastomer element 31 is placed on the upper side of the valve carrier 29, which is held by a slight radial preloading even in the event of a vibration movement of the piston rod 9. Starting from the stop point at the stop face, the elastomer element 31 acts as an additional support spring.

[0026] The valve carrier 29 has a surrounding annular groove 33, in which two valve elements 35A, 35B of variable diameter are guided. The basic structure of the valve elements, for example an annular element or a multipart valve element, is subordinate to the considerations of the function of the invention. The valve elements 35A, 35B are movable in the radial direction or are elastic in the radial direction and form as part of the damping valve device 1 a valve body for the throttle point 37. The valve elements 35A, 35B form with the inner wall 39 of the cylinder 11 an effective throttle point 37, wherein the inner wall 39 is a flow guide face. In principle, the invention can also be implemented in the valve carrier 29 independently of the pull stop.

[0027] As shown in particular in the enlarged view in Figure 2 On the cover side, each valve element 35A, 35B carries a separate return spring 41A, 41B. Between the inner wall 39 and the respective outer circumference 43A, 43B of the valve elements 35A, 35B there is a variable throttle cross section 45, which generates an additional damping force.

[0028] When the piston rod speed is in the first operating range, for example less than 1 m / s, the throttle point 37 is completely open. The damping force is then generated exclusively by the throughflow channels 17, 19 in conjunction with the valve discs 21, 23. In the flow direction to the valve discs 21, 23, the valve discs 21, 23 are lifted from their valve seat faces 47, 49. This lifting movement is in turn defined by the support discs 51, 53.

[0029] In the second operating range of the piston rod speed, which is greater than the limit speed of the first operating range, i.e. greater than the exemplarily given 1 m / s, the valve elements 35A, 35B, which are active depending on the flow direction of the damper valve, are transferred into a throttling state and perform a closing movement here in the direction of the flow guide face 39. Due to the high flow speed of the damping medium in the throttle point 37, which is formed as an annular gap, a negative pressure is formed, which causes the corresponding activated valve element 35A, 35B to expand radially. However, in order to never occur an occlusion of the throttle point 37, a defined minimum flow cross section is maintained by the return springs 41A, 41B or the expansion movement of the corresponding valve element is limited by a mechanical stop, for example at the valve carrier, and thus determines the minimum flow cross section. This operating characteristic is independent of the flow direction of the damper valve device 1.

[0030] Figure 2 An enlarged view of the damper valve device 1 according to Figure 1 is shown, which is fastened at the piston rod 9 by different technologies. It can be seen in this enlarged view that the annular groove 33 and thus the damper valve device 1 is configured for two flow-through directions. For this purpose, the valve carrier 29 has for each flow-through direction a corresponding valve element 35A, 35B in the annular groove 33.

[0031] Furthermore, the valve carrier 29 has two pressure chambers 55A, 55B, which each have at least one inflow opening 57A, 57B and at least one outflow opening 59A, 59B, wherein the effective inflow opening each has a greater cross section than the effective outflow opening. The inflow openings 57A, 57B in the valve carrier 29 are coupled to the working chamber 13.

[0032] Each pressure chamber 55A, 55B is formed by the inner peripheral face 61A, 61B of the valve element 35A, 35B, the annular groove side faces 63, 65 of the valve carrier 29 and the common annular groove base face 67. The pressure chambers 55A, 55B, which are each acted upon by the flow, generate a radially outwardly directed force component, which expands the valve element 35A, 35B, which supports the case of a negative pressure existing in the throttle point 37.

[0033] The two pressure chambers 55A, 55B are separated from one another by means of a partition wall 69. In the illustrated starting position of the damper valve device 1, the valve elements 35A, 35B lie in a large-area, sealingly abutting manner at the annular groove base face 65. The two valve elements 35A, 35B thus alternately form the partition wall.

[0034] Valve elements 35A and 35B have effective outflow openings 59A and 59B, which are formed, for example, by a groove in the inner circumferential surface of valve elements 35A and 35B and an annular groove base surface 65. Thus, the outflow openings 59A and 59B in the partition wall 69 are constructed between the two valve elements 35A and 35B. According to... Figure 2 In this embodiment, the outflow openings 59A and 59B in the valve element are configured as axial channels. The cross-sections of the outflow openings 59A and 59B in the two valve elements do not necessarily have to be configured to be the same size.

[0035] As can be clearly seen in the enlarged view, the two valve elements 35A and 35B have individual reset elastic elements 41A and 41B. These reset elastic elements 41A and 41B do not necessarily have the same structure; that is, they can have different reset forces. The axial extensions of the inner circumferential surfaces 61A and 61B of valve elements 35A and 35B can also be dimensionally different to generate different pressures on valve elements 35A and 35B. However, it is particularly advantageous for assembly if the damping valve device is constructed symmetrically with respect to the central axis of the lateral extension of the valve carrier 29.

[0036] When the damping valve device 1 is subjected to incoming flow, the damping medium flows into the pressure chamber 55A of the valve element 35A through the opening 57A in the valve carrier 29 in the first flow direction, causing a pressure rise that leads to the expansion movement of the valve element 35A. The inflow opening 57A in the valve carrier 29 is multiple times larger than the axial passage 59A in the valve element 35B. The axial passage in the stationary valve element serves as the outflow opening 59A. The flow of the damping medium through the second pressure chamber 55B and the opening 57B in the valve carrier 29 does not change the operating characteristics of the valve element 35A, and therefore does not change the operating characteristics of the damping valve device 1. The other valve element 35B remains in the position shown because the axial passage 59A of the pressure chamber 59B for the valve element 35B also serves as the inflow opening. Thus, a significant pressure difference exists between the pressure chamber 55A of the valve element 35A and the pressure chamber 55B of the valve element 35B. Due to the pressure drop relative to the pressure chamber 55A, the pressure in the pressure chamber 55B is insufficient to apply a significant pressure. Additionally, the reset elastic element 41B causes the valve element 35B to retain or fix at the annular groove base surface 65.

[0037] The damping valve device exhibits virtually the same operating characteristics when subjected to incoming flow during the retraction movement of piston rod 9 (i.e., via the opening). At this time, valve element 35A remains in its maximum channel position as shown, and the axial channel 59B in valve element 35A serves as an outflow opening for the pressure chamber 55B of valve element 35B.

[0038] according to Figure 3 The variant scheme follows the followingFigure 1 and Figure 2 The functional principle described is different in that the partition wall 69 is formed by a separate disk which is connected to the valve carrier 29. The partition wall 69 is arranged fixedly between the two housings 29A, 29B of the valve carrier 29.

[0039] Due to the inner peripheral surface which is inclined towards the annular groove base surface, the valve elements are preloaded with the cover side onto the partition wall.

[0040] The outflow opening 59 is in this configuration in the separate partition wall 69 and likewise connects the two pressure chambers 55A, 55B. There is a radial distance between the inner peripheral surface 61A, 61B of the valve elements 35A, 35B and the annular groove base surface 67, so that a free annular area of the disk is available for arranging the outflow opening 59. It can nevertheless be provided that the valve elements 35A, 35B overlap with the outflow opening 59 with their cover side facing the partition wall 69 in order to control the outflow cross section depending on the direction.

[0041] Figure 4 A variant of the damping valve device according to Figure 3 is likewise shown. The difference is that the outflow openings 59A, 59B are configured as radial passages in the valve elements 35A, 35B. In the starting position of the valve elements 35A, 35B, the radial passages are closed in the direction of the flow guide surface 39 and in the direction of the working chamber 13 on the one hand by the valve elements 35A, 35B and due to the valve elements being supported on the disk, more precisely the partition wall 69. The disk between the two valve elements 35A, 35B is fixed as a closed annular disk, so that there is no hydraulic connection between the two pressure chambers 55A, 55B.

[0042] When the damping valve device is acted upon, for example, by a flow through the inflow opening 57B, damping medium flows into the pressure chamber 55B and the radial passage 59B. A negative pressure is formed in the throttle point 37 and thereby an expansion force for the valve element 35B. The other valve element 35A is moved in the direction of the flow guide surface 39 or the inner wall of the cylinder body 11 only by the force of the negative pressure of the throttle point 37. The expansion force at the valve element 35A is therefore significantly lower. The damping force is thus always determined by the valve element which bears the greater expansion force.

[0043] Damping medium flows out of the pressure chamber through the radial passage 59B on the outside of the outer peripheral surface 43A of the valve element 35A and the partition wall 69. If the damping valve device 1 is flowed into via the inflow opening 57A, a mirror-symmetrical operating characteristic of the valve elements 35A, 35B occurs.

[0044] List of reference signs

[0045] 1 damping valve device

[0046] 3 damper

[0047] 5 first damping valve

[0048] 7 damping valve body

[0049] 9 piston rod

[0050] 11 cylinder

[0051] 13 working chamber on the piston rod side

[0052] 15 working chamber remote from the piston rod

[0053] 17 through channel

[0054] 19 through channel

[0055] 21 valve disc

[0056] 23 valve disc

[0057] 25 pull stop

[0058] 27 piston rod guide

[0059] 29 valve carrier

[0060] 31 elastomer element

[0061] 33 annular groove

[0062] 35A valve element

[0063] 35B valve element

[0064] 37 throttle point

[0065] 39 inner wall

[0066] 41A return spring

[0067] 41B return spring

[0068] 43A peripheral surface

[0069] 43B peripheral surface

[0070] 45 throttle cross section

[0071] 47 valve seat surface

[0072] 49 valve seat surface

[0073] 51 support disc

[0074] 53 support disc

[0075] 55A pressure chamber

[0076] 55B pressure chamber

[0077] 57A inflow opening

[0078] 57B inflow opening

[0079] 59 outflow opening

[0080] 59A outflow opening

[0081] 59B outflow opening

[0082] 61A inner peripheral surface

[0083] 61B inner peripheral surface

[0084] 63 annular groove side surface

[0085] 65 annular groove side surface

[0086] 67 annular groove base surface

[0087] 69 partition wall

Claims

1. Damper valve arrangement (1) for a shock absorber (3), comprising a throttle point (37) which cooperates with a valve element (35), which can be shifted from a throughflow state into a throttled state depending on the flow rate of the damping medium in the throttle point (37), wherein, The valve element (35) as a ring element of variable diameter moves in the ring groove (33) of the valve carrier (29) in the closing direction with increasing flow rate of the damping medium, characterized in that the valve carrier (29) has a valve element (35A, 35B) in the ring groove (33) for each flow direction through the damping valve device (1) respectively, and the ring groove (33) is configured to have two pressure chambers (55A, 55B) with at least one inflow opening (57A, 57B) and at least one outflow opening (59, 59A, 59B) respectively, wherein the effective inflow opening has a correspondingly larger cross section than the effective outflow opening.

2. The damping valve device according to claim 1, characterized in that The two pressure chambers (55A, 55B) are separated from one another by means of a partition wall (69).

3. The orifice valve device of claim 2, wherein, The partition wall (69) is formed by a disk connected to the valve carrier (29).

4. The orifice valve device of claim 3, wherein, The partition wall (69) is arranged between two housings (29A, 29B) of the valve carrier.

5. The orifice valve device of claim 2, wherein, The partition wall (69) is formed by two valve elements (35A, 35B).

6. The orifice valve device of claim 2, wherein, The partition wall (69) has the outflow openings (59).

7. The orifice valve device of claim 5, wherein, The valve elements (35A, 35B) have outflow openings (59A, 59B).

8. The orifice valve device of claim 7, wherein, The outflow openings (59A, 59B) in the valve elements (35A, 35B) are configured as axial passages.

9. The orifice valve device of claim 7, wherein, The outflow openings (59A, 59B) are configured as radial passages.

10. The damper valve device according to any one of claims 2 to 9, characterized in that, The valve elements (35A, 35B) are preloaded onto the partition wall (69) with a cover side.

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