Adjustable damping valve device for shock absorber

Abstract

The invention relates to an adjustable damping valve arrangement for a shock absorber, comprising a damping valve housing in which a primary valve for hydraulically controlling a primary valve is arranged, the damping valve housing being hydraulically coupled to a working space on the piston rod side of a working cylinder of the shock absorber and to a working space remote from the piston rod, the damping valve arrangement has a check valve arrangement for rectifying a control volume flow from the working space of the working cylinder to the primary valve, a first flow connection from the working space on the piston rod side to the primary valve having a greater throttling resistance than from the working space away from the piston rod to a second flow connection of the primary valve.

Description

Technical Field

[0001] The invention relates to an adjustable damping valve arrangement for a shock absorber according to the preamble of patent claim 1 . Background Art

[0002] DE 44 18 972 A1 relates to an adjustable damping valve arrangement comprising a valve housing on the piston rod of a shock absorber. The functional advantage of this damping valve arrangement is that a single primary valve is used to actuate the main stage valve for both inflow from the working space on the piston rod side and from the working space remote from the piston rod.

[0003] To this end, the damping valve arrangement has four check valves. These ensure the flow from the piston rod-side working space and the working space remote from the piston rod to the primary valve, and the outflow from the back space of the primary valve to both working spaces. The check valves for the switching flow are located on or within the main stage valve body.

[0004] The rectification of the volume flow at the primary valve is also relevant to the adaptation of the operating characteristics of the entire damping valve arrangement, since the primary valve also acts on the common main-stage valve. Although it is possible to provide pressure-bearing surfaces of different sizes on the main-stage valve for the two inflow directions from the working space, the damping force ratio achievable in this way in the pull / push direction is insufficient for certain applications. Summary of the Invention

[0005] The object of the present invention is to provide a damping valve arrangement having a primary valve which is effective in both operating directions of the shock absorber, wherein the damping force ratio is sufficiently large when the damping valve arrangement changes the inflow.

[0006] This object is achieved in that a first flow connection from the piston rod-side working space to the primary valve has a greater throttling resistance than a second flow connection from the piston rod-remote working space to the primary valve.

[0007] By relatively simple means, the force acting in the lifting direction of the primary valve can often be influenced by the pressure in the control chamber of the primary valve, depending on the operating direction of the shock absorber. The lifting force at the primary valve, or the associated pressure drop, in turn influences the pressure level in the control chamber of the main-stage valve, thereby controlling the closing force acting on the main-stage valve body.

[0008] In another advantageous embodiment, the first flow connection comprises a first throttle point and a second throttle point connected hydraulically in series. The first throttle point directly influences the closing force level via the pressure in the control chamber of the main-stage valve. The second throttle point determines the lifting force acting on the primary valve, thereby in turn controlling the pressure in the control chamber of the main-stage valve. The second throttle point is crucial for achieving a defined damping force characteristic, whereas the first throttle point is decisive for the maximum achievable closing force at a predetermined flow rate into the damping valve arrangement.

[0009] In order to ensure a simple channel arrangement within the damping valve arrangement, the first flow connection and the second flow connection open into a common control chamber of the primary valve.

[0010] To prevent hydraulic short-circuits within the damping valve arrangement, the hydraulic connection between the two working spaces via the first and second flow connections is blocked by a check valve assembly. The size of the second throttle section has no effect on flow through the second flow connection to the primary valve, as the closed check valve at the first throttle section of the first flow connection prevents damping medium flow at the second throttle section. When flow through the second flow connection to the primary valve, the pressure in the first control chamber of the main-stage valve is the same as the pressure in the control chamber of the primary valve. The hydraulic function of the two flow connections enables different damping force characteristics to be achieved in different operating directions of the shock absorber.

[0011] Preferably, the second flow connection has a check valve chamber, which is arranged upstream of the throttle portion of the second flow connection. The check valve chamber can provide a large volume flow for actuating the check valve that opens in the direction of the primary valve, which large volume flow quickly and reliably opens the check valve.

[0012] In a further advantageous embodiment, the non-return valve chamber accommodates at least one non-return valve disk, which interacts with at least one inflow channel.

[0013] As a further measure for the simple design of the invention, both flow connections are formed within the main stage valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be described in more detail with reference to the following drawings, wherein:

[0015] Figure 1 and Figure 2 A cross section of the damping valve arrangement is shown;

[0016] Figure 3 Shown Figure 1 Detailed view of the main stage valve body;

[0017] Figure 4 Shown Figure 1 and Figure 2 The check valve ring as an independent component;

[0018] Figure 5 Shown Figure 1 and Figure 2 The check valve disc as an independent component;

[0019] Figure 6 Shown Figure 1 and Figure 2 Detailed view of the check valve assembly;

[0020] Figure 7 and Figure 8 Shown Figure 6 The cover ring is a separate component. DETAILED DESCRIPTION

[0021] Figure 1 and Figure 2 The adjustable damping valve arrangement 1 of the shock absorber 3 is shown in sections in different planes. In this exemplary embodiment, the damping valve arrangement 1 is shown located in the damping valve housing 5 on the axially movable piston rod 7 within the working cylinder 9 of the shock absorber 1. However, the damping valve housing 5 and therefore the damping valve arrangement 1 can also be arranged spatially outside the shock absorber 1 and, for example, hydraulically connected via a line or hose connection.

[0022] The damping valve arrangement 1 comprises an electromagnetic actuator 11 with a solenoid coil 13 and an armature 15 , which acts on the primary valve body 17 of a primary valve 19 at its end. At least one return spring 21 counteracts the force of the solenoid coil 13 .

[0023] The primary valve 19 serves for hydraulically actuating a main stage valve 23 , via which a piston rod-side working space 25 and a piston rod-remote working space 27 in the working cylinder 9 are connected to one another. Figure 1 The radial connecting channel 29 in the valve housing ring 31, a component of the damping valve housing 5, is shown. This connecting channel connects the piston rod-side working space 25 to the main stage valve 23. For the flow direction of the damping valve arrangement 1, passive damping valves 33 and 35 are arranged between the working space 27 remote from the piston rod and the main stage valve 23. The two passive damping valves 33 and 35 can be used selectively. Regardless of the working direction of the piston rod 7 in the shock absorber 3, the damping force-determining volume flow of the damping medium present in the working cylinder 9 is discharged via the connecting channel 29, the main stage valve 23, and the two passive damping valves 33 and 35. Furthermore, a separating piston 36, as a functional section of the damping valve housing 5, ensures the spatial separation of the two working spaces 25 and 27.

[0024] The main stage valve 23 includes a main stage valve body 37 and a main stage valve seat surface 39 (see Figure 3), the main-stage valve seat surface is formed by the valve ring 41 within the valve housing ring 31. Functionally, the main-stage valve body 37 consists of two parts. The first functional section forms the closing element 37A, which, together with the main-stage valve seat surface 39, determines the throttling cross section of the main-stage valve 23. The second functional section is formed by the separating piston 37B, which is fixedly connected to the closing element 37A and thus performs a synchronous displacement movement. The main-stage valve body 37 is guided axially displaceably within a stepped opening 43 of the valve housing ring 31. The separating piston 37B isolates the inner side surface 43A of the stepped opening 43. The separating piston 37B, a portion of the side surface 43A, and the bottom 43B of the stepped opening 43 form a first control chamber 45. This first control chamber 45 is connected to the radial connecting channel 29 via at least one first throttle 47. Due to the throttling function of the first throttle 47, a pressure drop occurs between the pressure in the connecting channel 29 and the pressure in the first control chamber 45.

[0025] The separating piston 37B has a valve pin 49 pointing toward the primary valve 19 and having a primary valve seat surface 51 on its end for the primary valve body 17. The valve pin 49 is hollow and has at least one radial connecting opening 53 leading to an axial channel 55. The axial channel represents the second control chamber 61 of the mainstage valve body 37. The radial connecting opening 53 is designed as a second throttle, which allows a pressure difference between the first and second control chambers of the mainstage valve body 37. The first throttle 47, the first control chamber 45, and the second throttle 53 form a first flow connection 57 between the piston rod-side working space 25 and the primary valve 19, with the two throttles 47, 53 being arranged hydraulically in series.

[0026] At least one inlet channel 63 extends within the closing body 37A of the main stage valve body 37, which connects the connecting chamber 65 of the damping valve arrangement 1 with the check valve chamber 59. The check valve chamber 59 is hydraulically connected upstream of a throttle valve 64 located in an intermediate wall 66 between the check valve chamber 59 and the axial channel 55. Figure 3At least one inflow channel 63, the check valve chamber 59, and the throttle valve 64 leading to the axial channel 55 form a second flow connection 68, which connects the working space 27 remote from the piston rod with the primary valve 19. The first flow connection 57, with its two throttle valves 47 and 53, achieves a greater throttling resistance than the second flow connection 68, with its single throttle valve 64. Both flow connections 57 and 68 lead to the second control chamber 61 of the main-stage valve 23, which also functionally forms a common control chamber for the primary valve 19 for both flow directions from the working spaces 25 and 27. The second control chamber 61 extends relative to the main-stage valve body 37 between the intermediate wall 66 and the primary valve 19. Therefore, both flow connections 57 and 68 are designed within the main-stage valve body 37 to lead to the primary valve 19. The at least one inflow channel 63 is also connected to the first control chamber 45 via the second throttle valve 53. The first throttle 47 and at least one inflow channel 63 between the throttle 64 in the connecting chamber 65 and the second flow connection 68 are each equipped with check valves 67 and 69. Both check valves 67 and 69 open in the direction of flow toward the primary valve 19 and close during return flow from the axial channel 55 into the working spaces 25 and 27. A check valve disk 67S is movably mounted in the first control chamber 45. This prevents a hydraulic short-circuit of the primary valve 19 via the first control chamber 45. The check valve chamber 59 accommodates at least one check valve disk 69S, which is lifted from a check valve seat surface 69V formed on the closing body 37A by damping medium flowing into the check valve chamber 59 via the at least one inflow channel. The bottom of the separating piston 37B of the main stage valve body 37 forms a lift limiter for the check valve disk 69S.

[0027] The lift of the primary valve body 17 from the primary valve seat surface 51 determines the throttling cross section, which in turn determines the pressure levels in the first control chamber 45 and the second control chamber 61. The pressures in the two control chambers 45 and 61 multiplied by the axial pressure-bearing area at the separating piston 37B generate a closing force acting on the main-stage valve body 37. This closing force determines the damping force of the shock absorber 3 under a given working motion of the shock absorber 3.

[0028] The damping medium passing through the primary valve 19 reaches the back space 71 of the primary valve between the bottom of the valve housing ring 31 and the actuator 11. The back space is connected to a check valve assembly 73, which includes a check valve ring 75, which is equipped with at least one check valve disc 77, 79 on both sides. Figure 5The check valve ring 75 is a separate and replaceable component from the valve housing ring 31. The check valve discs 77 and 79 on both sides, combined with the check valve ring 75, form two check valves 81 and 83 for controlling the control volume flow from the primary valve 19 into the two working spaces 25 and 27 of the working cylinder 9. In the flow direction from the check valve assembly 73 toward the working space 25 on the piston rod side, the damping valve housing 5 has at least one connecting opening 85, which is radial in this example. In order to connect the primary valve 19 to the working space 27 remote from the piston rod, the valve housing ring 31 has a channel system 87 leading to the connecting chamber 65. When flow from one of the two working spaces 25 and 27 flows to the check valve assembly 73, the check valve 81 and 83 to which the flow is directed, i.e., bypassing the primary valve 19, is closed.

[0029] The check valve ring 75 is centered relative to the valve housing ring 31 via its central through hole 89. Figure 4 As shown, the non-return valve ring 75 has an annular groove 91 facing the back space 71, which in turn includes an axial connection opening 93 leading to the channel system 87 in the valve housing ring 31. The annular groove 91 is radially delimited by two annular support surfaces 95, 97 for the non-return valve disk 77. The inner support surface 97 is interrupted by at least one radial channel 99, which connects the annular groove 91 to a radially inner connection channel 101. The connection channel 101 is directly connected to the back space 71 of the primary valve 19.

[0030] The two non-return valve discs 77, 79 are likewise preferably centered relative to the valve housing ring 31. In principle, it is also conceivable that at least one valve disc 77, 79 is centered relative to the non-return valve ring 75. The non-return valve discs 77, 79 preferably have a Figure 5 , which has an inner centering web 103 , which allows an unhindered flow of damping medium from the rear space 71 into the connecting channel 101 .

[0031] The lifting movement of the non-return valve disc 79 for the channel system 87 in the valve housing ring 31 is limited by the valve housing ring 31. For the lifting movement of the non-return valve disc 77 on the upper side of the non-return valve ring 75, a cover ring 103 is used, which additionally fixes the non-return valve ring 75 axially in the damping valve housing 5. Figure 7 、 Figure 8The cover ring 103 is shown as a separate component. It also has at least one connecting channel 107 at the central through-hole 105 for connecting the back space 71 of the primary valve 19 to the connecting channel 101 in the non-return valve ring 75. The cover ring 103 is also centered relative to the valve housing ring 31. To this end, it has a central centering projection 109, relative to which the non-return valve ring 75 and the non-return valve disks 77, 79 are also centered. The support surface 111 of the cover ring 103 serves to limit the lifting movement of the non-return valve disk 77.

[0032] When the damping medium flows toward the damping valve arrangement 1 due to compression away from the working space 27 of the piston rod, it flows through the passive damping valve 35 and, in the connecting chamber 65, pressurizes the mainstage valve body 37 within the pressure-bearing surface defined by the mainstage valve seat surface 39. The control volume flow passes through the inlet channel 63 and the open check valve 69 to the check valve chamber 59. On the further flow path, it flows through the throttle 64 of the second flow connection 68. Starting from the control chamber 61 of the primary valve 19, a closing pressure is built up in the first control chamber 45 via the connecting opening 53. For this inflow direction of the damping valve arrangement 1, the connecting opening 53 does not act as a throttle, as no damping medium flows into the first control chamber 45. The check valve 67 prevents damping medium from flowing out of the control chamber, and therefore no damping medium can flow in. The pressure in both control chambers 45, 61 exerts a hydraulic closing force on the mainstage valve body 37. The control volume flow flows via the primary valve 19 and the non-return valve disk 77 lifted from the non-return valve ring 75 , through the connecting opening 85 into the piston rod-side working space 25 .

[0033] Damping medium acting on the non-return valve 83 via the channel system 87 in the valve housing ring 31 closes the non-return valve 83. Under this inflow of the damping valve arrangement 1, the non-return valve 67 in the separating piston 37B of the main stage valve body 37 is also closed.

[0034] When the damping medium flows from the piston rod-side working space 25 into the damping valve arrangement 1, the displaced damping medium acts on the annular surface of the main-stage valve body 37, which extends radially outside the main-stage valve seat surface 39 of the main-stage valve 23 and within the side surface 43A of the valve housing ring 31. This pressure also generates a lifting force on the main-stage valve body 37. Similarly, the first control chamber 45 is hydraulically pressurized in parallel via the first throttle 47. This, in interaction with the second throttle 53, also generates a pressure increase in the second control chamber 61. This pressure increase, together with the pressure increase in the first control chamber 45, generates a closing force on the main-stage valve body 37. At this time, the control volume flow flowing through the primary valve 19 into the back space 71 also reaches the connecting channel 101, enters the annular groove 91 through at least one radial channel 99, and can then flow through the connecting opening 93 integrated with the channel system 87 into the connecting chamber 65. From there, it flows through the passive damping valve 33 into the working space 27 remote from the piston rod. Here, the check valve 81 in the direction of the working space 25 on the piston rod side is also closed by the reverse flow from the working space 25 on the piston rod side, thereby achieving rectification of the control volume flow through the primary valve 19 by using a total of four check valves 67, 69, 81, 83.

[0035] Reference Signs List

[0036] 1 Adjustable damping valve device

[0037] 3 shock absorbers

[0038] 5 Damping valve housing

[0039] 7 Piston rod

[0040] 9 working cylinders

[0041] 11 Actuator

[0042] 13. Electromagnetic coil

[0043] 15 Armature

[0044] 17 Primary valve body

[0045] 19 Primary valve

[0046] 21 Return spring

[0047] 23 Main stage valve

[0048] 25 Working space on the piston rod side

[0049] 27 Working space away from piston rod

[0050] 29 Radial connecting channel

[0051] 31 Valve housing ring

[0052] 33 Passive Damping Valve

[0053] 35 Passive Damping Valve

[0054] 36 pistons

[0055] 37 Main stage valve body

[0056] 37A Main stage valve body closing body

[0057] 37B Main stage valve body release piston

[0058] 39 Main stage valve seat surface

[0059] 41 valve ring

[0060] 43 Stepped opening of valve housing ring

[0061] 43A Side surface of stepped opening

[0062] 43B Bottom of stepped opening

[0063] 45 First Control Room

[0064] 47 First throttle section

[0065] 49 Valve pin

[0066] 51 Primary valve seat surface

[0067] 53 connection opening (second throttle portion)

[0068] 55 Axial channel

[0069] 57 First-stream connection

[0070] 59 Check valve chamber

[0071] 61 Second control chamber of main stage valve / control chamber of primary valve

[0072] 63 inflow channel

[0073] 64 throttle portion in the second flow connection

[0074] 65 Connection Room

[0075] 66 Middle wall

[0076] 67 Check valve

[0077] 67S Check Valve Disc

[0078] 67V check valve seat surface

[0079] 68 Second flow connection

[0080] 69 Check valve

[0081] 69S Check Valve Disc

[0082] 71 back space

[0083] 73 Check valve assembly

[0084] 75 Check valve ring

[0085] 77 Check valve disc

[0086] 79 Check valve disc

[0087] 81 Check valve

[0088] 83 Check valve

[0089] 85 connection opening

[0090] 87-channel system

[0091] 89 through holes

[0092] 91 annular groove

[0093] 93 connection opening

[0094] 95 support surface

[0095] 97 Support surface

[0096] 99 radial channels

[0097] 101 Connection Channel

[0098] 103 Cover Ring

[0099] 105 through hole

[0100] 107 Axial connecting channel

[0101] 109 Centering protrusion

[0102] 111Support surface.

Claims

1. An adjustable damping valve arrangement (1) for a shock absorber (3), comprising a damping valve housing (5), in which a primary valve (19) for hydraulically controlling a main stage valve (23) is arranged, wherein: The damping valve housing (5) is hydraulically connected to a working space (25) on the piston rod side and a working space (27) remote from the piston rod of a working cylinder (9) of the shock absorber (3), wherein the damping valve device (1) has a check valve assembly for rectifying a control volume flow from the working space (25, 27) of the working cylinder (9) to the primary valve (19), characterized in that a first flow connection (57) from the working space (25) on the piston rod side to the primary valve (19) has a greater throttling resistance than a second flow connection (68) from the working space (27) remote from the piston rod to the primary valve (19).

2. The adjustable damping valve device (1) according to claim 1, characterized in that: The first flow connection (57) comprises a first throttle point (47) and a second throttle point (53) which are hydraulically connected in series.

3. The adjustable damping valve device (1) according to claim 1 or 2, characterized in that: The first flow connection (57) and the second flow connection (68) open into a common control chamber (61) of the primary valve (19).

4. The adjustable damping valve arrangement (1) according to at least one of claims 1 to 3, characterized in that The hydraulic connection between the two working spaces (25, 27) via the first flow connection (57) and the second flow connection (68) is blocked by the non-return valve assembly (47, 67, 64, 69).

5. The adjustable damping valve arrangement (1) according to at least one of claims 1 to 4, characterized in that The second flow connection (68) has a check valve chamber (59) which is connected upstream of the throttle (64) of the second flow connection (68).

6. The adjustable damping valve device (1) according to claim 5, characterized in that: The non-return valve chamber (59) accommodates at least one non-return valve disc (69S), which interacts with at least one inflow channel (63).

7. The adjustable damping valve arrangement (1) according to at least one of claims 1 to 6, characterized in that Both flow connections (57, 68) are designed in the main stage valve body (37).

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