Adjustable damping valve device for shock absorber

Abstract

The invention relates to an adjustable damping valve arrangement for a shock absorber, having a pilot valve for hydraulically controlling a main stage valve, said pilot valve being connected to a working chamber on the piston rod side of a working cylinder of the shock absorber and to a working chamber remote from the piston rod, a check valve assembly with at least two check valves is arranged on a main stage valve body of the main stage valve in order to rectify a control volume flow from a working chamber of a working cylinder to the pilot valve, the main stage valve body having at least one first throttle channel with a first check valve disk on a larger pitch circle, the first throttle channel having a second check valve disk on a larger pitch circle, and the second throttle channel having a second check valve disk on a larger pitch circle. A second throttling channel with a second check valve disc is arranged on the smaller pitch circle, and the two check valves are connected to a control chamber for the main-stage valve body in the opening direction.

Description

Technical Field

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

[0002] Document DE 44 18 972 A1 relates to an adjustable damping valve arrangement comprising a valve housing located on the piston rod of a shock absorber. The functional advantage of this damping valve arrangement is that a single pilot valve is used to actuate the main stage valve for flows originating from the piston rod-side working chamber and the working chamber remote from the piston rod.

[0003] To this end, the damping valve arrangement has a total of four non-return valves, which ensure that the volume flows from the working chamber on the piston rod side and the working chamber remote from the piston rod to the pilot valve are rectified, and that the volume flow from the return chamber of the pilot valve flows out to both working chambers. The non-return valves that switch the inflow flow are located on or in the main stage valve body.

[0004] Due to the limited installation space and complex flow path, it is very difficult to arrange the check valve in the damping valve device. Summary of the Invention

[0005] The object of the present invention is to provide a damping valve arrangement having a compact check valve assembly.

[0006] This object is achieved in that the mainstage valve body has at least one first throttle channel with a first non-return valve disk on the larger pitch circle and a second throttle channel with a second non-return valve disk on the smaller pitch circle, wherein both non-return valves are connected in the opening direction to a control chamber for the mainstage valve body.

[0007] Due to the radial arrangement of the two check valves relative to each other, separate throttling channels are provided, which can have different throttling characteristics. In addition, the channel layout is simple and the existing control chamber can be used to guide the fluid to the pilot valve.

[0008] In another advantageous design, the check valve disk of one check valve performs a stopping function relative to the check valve disk of the other check valve, thereby simplifying the structural design of the check valve assembly.

[0009] According to an advantageous dependent claim, the radially outer valve seat surface and the radially inner valve seat surface of one of the check valve disks form an annular groove, into which at least one throttle channel of the check valve opens. In particular, the check valve disk, which forms the stop element, is stably supported by resting on the valve seat surface and prevents unilateral tilting movement. Furthermore, the diameter of the throttle channel has no influence on the dimensions of the pressure-bearing surface of the check valve disk.

[0010] Furthermore, it is provided that the valve seat surface of one annular groove is axially offset relative to the valve seat surface of the other annular groove. The clearance required for the lifting path of one of the non-return valve disks is not achieved by a complex valve assembly of the non-return valve forming the stop, but rather very simply by the axial offset.

[0011] A further measure for a simple structural design of the non-return valve assembly is that the non-return valve disk forming the stop has a profiled portion on the edge side, which, when axially overlapping with another non-return valve disk in its stop position, provides a through cross section between the throttling channel of the open non-return valve and the control chamber of the main stage valve.

[0012] In another advantageous embodiment, the profile of the non-return valve disk forms a guide profile for the non-return valve disk on the main stage valve body. The combination of the two functions of guidance and forming the through-cross section results in an optimal distribution of the functional areas on the non-return valve disk. On the one hand, this results in a large annular sealing area and a similarly large profile area, which in particular leads to a certain advantageous elasticity of the non-return valve disk.

[0013] Preferably, provision is made for both non-return valve disks to be centered on the guide pins of the main stage valve body. This requires only one common guide area, so that this measure also requires a simple construction of the damping valve device.

[0014] The mainstage valve body has an axial stop for limiting the lifting of the check valve disk. In particular, when the profiled area is used in conjunction with the annular guide groove in the mainstage valve body, the check valve disk serving as the stop can be easily assembled, while additional components, such as a retaining ring for axially securing the check valve disk, are not required.

[0015] Preferably, the axial stop is formed by a guide pin of the main-stage valve body.

[0016] In an alternative embodiment, the check valve assembly has a separate stop disk for the check valve disk of the throttle channel. Here, the stop disk is also arranged on the main stage valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be explained in more detail based on the following description of the accompanying drawings.

[0018] in:

[0019] Figure 1 A cross section of a damping valve arrangement is shown;

[0020] Figure 2 Shown Figure 1 A cutout section in the region of the main stage valve and pilot valve;

[0021] Figure 3 A detailed view in the area of ​​the main stage valve is shown;

[0022] Figure 4 Shown according to Figure 1-3 Check valve disc shown as a separate component; and

[0023] Figure 5 Shown according to Figure 2-4 Alternative embodiments of the variants shown. DETAILED DESCRIPTION

[0024] Figure 1 A cross section through an adjustable damping valve arrangement 1 for a shock absorber 3 is shown. In this exemplary embodiment, the damping valve arrangement 1 is shown situated in a damping valve housing 5, which is located on an axially displaceable piston rod 7 in a 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 3 and hydraulically connected, for example, via a line or hose connection.

[0025] The damping valve arrangement 1 comprises an electromagnetic actuator 11 with a solenoid coil 13 and an armature 15 , which acts on the front side on a pilot valve body 17 of a pilot valve 19 . The force of the solenoid coil 13 acts in opposition to at least one return spring 21 .

[0026] The pilot valve 19 serves for hydraulically actuating a main stage valve 23 , via which a piston rod-side working chamber 25 and a piston rod-remote working chamber 27 in the working cylinder 9 are connected to one another. Figure 1 The radial connecting channels 29 within the valve housing ring 31, a component of the damping valve housing 5, are shown. These connecting channels connect the piston rod-side working chamber 25 to the main stage valve 23. Passive damping valves 33 and 35 are arranged between the working chamber 27 remote from the piston rod and the main stage valve 23 for each flow direction of the damping valve arrangement 1. Both passive damping valves 33 and 35 are selectively operable. Regardless of the working direction of the piston rod 7 within the shock absorber 3, the damping force-determining volume flow of the damping medium located in the working cylinder 9 is discharged via the connecting channels 29, the main stage valve 23, and the two passive damping valves 33 and 35. Furthermore, a sealing piston 36, as a functional section of the damping valve housing 5, ensures the spatial separation of the two working chambers 25 and 27.

[0027] The main stage valve 23 includes a main stage valve body 37 and a main stage valve seat surface 39 (see Figure 2 ), the main stage valve seat surface is formed by the valve ring 41 in the valve housing ring 31.

[0028] The main-stage valve body 37 is guided axially displaceably within a stepped opening 43 of the valve housing ring 31. The main-stage valve body 37 seals against a side surface 43A on the inside of the stepped opening 43. The main-stage valve body 37, a portion of the side surface 43A, and a bottom 43B of the stepped opening 43 form a control chamber 45 for the main-stage valve 23. This control chamber 45 is connected to the radial interface channel 29 via at least one first throttle channel 47 on a larger pitch circle. Due to the throttling function of the throttle channel 47, a pressure drop exists between the pressure in the interface channel 29 and the pressure in the control chamber 45. The pressure in the control chamber 45 exerts pressure on the main-stage valve body 37, which acts as a closing force for the main-stage valve 23.

[0029] The throttle channel 47 is covered by a first check valve disk 67. On the smaller pitch circle, the mainstage valve body 37 has a second throttle channel 61 with a second check valve disk 69. Two check valves 47; 67 and 61; 69 are connected to the control chamber 45 in the opening direction. The second throttle channel 61 is connected to the connecting chamber 65, which in turn is connected to the piston rod-side working chamber 27 via two passive damping valves. The main function of the two check valves 47; 67 and 61; 69 is to prevent a hydraulic short circuit between the two working chambers 27; 29 via the control chamber 45 of the mainstage valve 23.

[0030] The main stage valve body 37 has a guide pin 49 pointing in the direction of the pilot valve 19 and having a pilot valve seat surface 51 at its end for the disk-shaped pilot valve body 17. The guide pin 49 is hollow and has at least one radial connection opening 53 leading to an axial channel, in which the pressure is the same as the pressure in the first control chamber 45. The radial connection opening can also serve as a second throttle connected in series with the throttle channel 47; 61.

[0031] The axial channel forms a second control chamber 55 for the main stage valve, which has a second closing force on the main stage valve body 37. For the pilot valve 19, the axial channel forms a control chamber 57 which has a pressure component in the lifting direction of the pilot valve 19.

[0032] The damping medium expelled through the pilot valve 19 reaches the return chamber 71 of the pilot valve 19, located between the bottom 43B of the valve housing ring 31 and the actuator 11. This return chamber is connected to a check valve assembly 73, which comprises a check valve ring 75 equipped with at least one check valve disk 77, 79 on both sides. The check valve ring 75 is a separate and replaceable component from the valve housing ring 31. The check valve disks 77, 79, combined with the check valve ring 75, form two check valves 81, 83 to control the control volume flow from the pilot valve 19 into the two working chambers 25, 27 of the working cylinder 9. The damping valve housing 5 has at least one connecting opening 85, which, in this example, is radial in the direction of flow from the check valve assembly 73 toward the piston rod-side working chamber 25. In order to connect the pilot valve 19 to the working chamber 27 remote from the piston rod, the valve housing ring 31 has a channel system 87 that opens into the connection chamber 65. When flow flows from one of the two working chambers 25; 27 to the non-return valve assembly 73, the non-return valve 81; 83 that is directly impacted (i.e., bypassing the pilot valve 19) is closed.

[0033] The non-return valve ring 75 is centered on the valve housing ring 31 via its central through-hole 89 . The non-return valve ring 75 has a meandering channel 91 toward the return chamber 71 , which in turn comprises an axial connection opening 93 to the channel system 87 in the valve housing ring 31 .

[0034] Figures 2 to 4 The overview shows the structural design of the check valves 47; 67 and 61; 69.

[0035] The radially outer valve seat surface 95; 101 and the radially inner valve seat surface 97; 103 of one of the check valve disks 67; 69 each form an annular groove 99; 105, into which the at least one throttle channel 47; 61 of the check valve opens. The valve seat surface 95; 97 of one annular groove has an axial offset 107 relative to the valve seat surface 101; 103 of the other annular groove.

[0036] The larger-diameter check valve disc 67 of one check valve acts as a stop for the smaller-diameter check valve disc 69 of the other check valve. The annular grooves 99 and 105, or the axial offset 107 between the valve seat surfaces, provide the necessary clearance for the lifting movement of the check valve disc 69 when the check valves 47 and 67 are closed. In principle, this clearance could also be achieved by assembling the valve discs of the check valves 47 and 67 in a different manner, but this would involve significantly greater assembly effort.

[0037] The non-return valve disk 67 forming the stop has a profile 109 on the edge side (here at the inner diameter) which, when axially superposed on the other non-return valve disk 69 in its stop position, provides a through-cross section 111 between the throttle channel 69 of the open non-return valve and the control chamber 45 of the main stage valve 23. The profile 109 is formed by elastic fingers 113, each of which defines a T-shaped slot whose maximum radial extent is greater than the outer diameter of the non-return valve disk 69.

[0038] The profile 109 of the non-return valve disc 67 forms a guide profile 115 of the non-return valve disc 67 on the main stage valve body 37, wherein the inner diameter of the guide profile 115 is adapted to the guide section 117 of the guide pin 49. Figure 3 ) The guide profile 115 forms a clearance fit with the guide section 117 , which ensures a smaller displacement force for moving the check valve disk 67 on the guide pin 49 .

[0039] In the present example, both check valve discs 67 and 69 are centered on the guide pin 49 of the main-stage valve body. The guide diameter for the check valve disc 69 on the guide section 117 is slightly larger than the guide diameter for the check valve disc 67. This is because the main-stage valve body 37 has an axial stop 119 for limiting the lifting of the check valve disc 67. This axial stop is formed by the guide pin 49 of the main-stage valve body. To this end, the guide pin has an annular groove 121 for accommodating the profile 109 of the check valve disc 67. Axially above the annular groove 121, the guide pin 49 has a shorter conical profile 123. This conical profile slightly widens the inner diameter of the profile 109 during the assembly movement of the check valve disc 67, so that the groove flanks of the annular groove 121 form the axial stop 119 for the check valve disc.

[0040] according to Figure 5 The embodiment described with Figures 1 to 3Compared to the very similar damping valve arrangement 1, the check valve assembly for the check valve disks 61 and 69 of the throttle channels 47 and 67 differs in that it features a separate stop disk 125, which is positioned on the guide pin 47 of the mainstage valve body 37. The check valve disks 67 and 69 are designed as simple, profile-free annular disks, with the larger check valve disk 67 centered on the annular wall 37R of the mainstage valve body 37, while the smaller valve disk is centered on the guide pin 47. Two closing springs 127 and 129 ensure that the check valve disks 67 and 69 are in a defined position, for example, when the damping medium flow within the damping valve arrangement 1 is at rest. In this case, the valve disks 67 and 69 also rest on the valve seat surfaces 95 and 97, 101 and 103, so that the excess pressure in the control chamber 45 always supports the check valve disk currently resting on the valve seat surface in performing its closing function. The stop disk 125 has, for example, openings 131 extending in the circumferential direction, which ensure a connection between the control chamber 45 and the connection opening when the non-return valve disk 67 ; 69 is in the stop position.

[0041] Regardless of the design of the check valve 47; 67; 61; 69, the damping medium passes through the passive damping valve 35 when it flows into the damping valve device 1 due to compression in the working chamber 27 away from the piston rod, and ensures that the main stage valve body 37 is loaded with pressure in the pressure-bearing surface defined by the main stage valve seat surface 39 in the interface chamber 65.

[0042] The pressure in the two control chambers 45; 55 exerts a hydraulic closing force on the main stage valve body 37. The control volume flows via the pilot 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 chamber 27.

[0043] 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. In this case of inflow into the damping valve arrangement 1, the non-return valve 67 in the main stage valve body 37 is also closed.

[0044] When damping medium flows from the piston rod-side working chamber 25 into the damping valve arrangement 1, the displaced damping medium accumulates at the annular surface of the main-stage valve body 37, which extends radially outward from 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. The first control chamber 45 of the main-stage valve 23 is also hydraulically pressurized in parallel via the first throttle passage 47, causing a pressure increase in the second control chamber 55 of the main-stage valve 23. 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.

[0045] The control volume flow flowing through the pilot valve 19 into the return chamber 71 then also reaches the connection channel 101, enters the meandering channel 91 via at least one radial channel 99, and can then flow out into the connection chamber 65 via the connection opening 93 in conjunction with the channel system 87, and then further out through the passive damping valve 35 into the working chamber 27 remote from the piston rod. In this case, the check valve 81 is also closed in the direction of the piston rod-side working chamber 25 due to the reverse flow from the piston rod-side working chamber 25, so that the control volume flow through the pilot valve 19 is rectified by the use of a total of four check valves 67; 69; 81; 83.

[0046] List of reference numerals:

[0047] 1 Adjustable damping valve device

[0048] 3 shock absorbers

[0049] 5 Damping valve housing

[0050] 7 Piston rod

[0051] 9 working cylinders

[0052] 11 Actuator

[0053] 13 Excitation coil

[0054] 15 Armature

[0055] 17 Pilot valve body

[0056] 19 Pilot valve

[0057] 21 Return spring

[0058] 23 Main stage valve

[0059] 25 Working chamber on the piston rod side

[0060] 27 Working chamber away from the piston rod

[0061] 29 radial interface channels

[0062] 31 Valve housing ring

[0063] 33 Passive Damping Valve

[0064] 35 Passive Damping Valve

[0065] 36 pistons

[0066] 37 Main stage valve body

[0067] 37R main stage valve body annular wall

[0068] 39 Main stage valve seat surface

[0069] 41 valve ring

[0070] 43 Stepped opening of valve housing ring

[0071] 43A Side surface of stepped opening

[0072] 43B stepped opening bottom

[0073] 45 First control chamber

[0074] 47 First throttle channel

[0075] 49 guide pin

[0076] 51 Pilot valve seat surface

[0077] 53 interface opening

[0078] 55 Second control chamber of the main stage valve

[0079] 57 Control chamber of pilot valve

[0080] 61 Second throttle channel

[0081] 65 Interface chamber

[0082] 67 Check valve disc

[0083] 69 Check valve disc

[0084] 71 Reflow Chamber

[0085] 73 Check valve assembly

[0086] 75 Check valve ring

[0087] 77 Check valve disc

[0088] 79 Check valve disc

[0089] 81 Check valve

[0090] 83 Check valve

[0091] 85 connection opening

[0092] 87-channel system

[0093] 89 through opening

[0094] 91 Bend Channel

[0095] 93 interface opening

[0096] 95 External valve seat surface

[0097] 97 Inner valve seat surface

[0098] 99 Annular groove

[0099] 101 outer valve seat surface

[0100] 103 inner valve seat surface

[0101] 105 annular groove

[0102] 107 axial offset

[0103] 109 Special Shape Department

[0104] 111 through cross section

[0105] 113 finger-like parts

[0106] 115 guide special-shaped part

[0107] 117 boot sector

[0108] 119 axial stop

[0109] 121 annular groove

[0110] 123 conical special-shaped part

[0111] 125 stop plate

[0112] 127 closing spring

[0113] 129 closing spring

[0114] 131 Opening in the stop disc.

Claims

1. An adjustable damping valve arrangement (1) for a shock absorber (3), comprising a pilot valve (19) for hydraulically controlling a main stage valve (23), wherein: The pilot valve (19) is connected to a working chamber (25) on the piston rod side of the working cylinder (9) of the shock absorber (3) and a working chamber (27) remote from the piston rod, wherein at least two check valves (47; 67; 61; 69) are arranged on the main stage valve body (37) of the main stage valve (23) to rectify the control volume flow flowing from the working chamber (25; 27) of the working cylinder (9) to the pilot valve (19), characterized in that the main stage valve body (37) has at least one first throttling channel (47) with a first check valve disk (67) on a larger pitch circle and a second throttling channel (61) with a second check valve disk (69) on a smaller pitch circle, wherein the two check valves (47; 67; 61; 69) are connected in the opening direction to the control chamber (45) for the main stage valve body (37).

2. The adjustable damping valve device (1) according to claim 1, characterized in that: The check valve disc (67) of one check valve performs a stopping function for the check valve disc (69) of the other check valve.

3. The adjustable damping valve device (1) according to claim 1 or 2, characterized in that: The radially outer valve seat surface (95; 101) and the radially inner valve seat surface (97; 103) for one of the non-return valve disks (67; 69) respectively form an annular groove (99; 105), into which at least one throttling channel (47; 61) of the non-return valve respectively opens.

4. The adjustable damping valve device (1) according to claim 3, characterized in that: The valve seat surface (95; 97) of one of the annular grooves (99) is axially offset relative to the valve seat surface (101; 103) of the other annular groove (105).

5. The adjustable damping valve arrangement (1) according to at least one of claims 1 to 4, characterized in that The non-return valve disk (67) forming the stop has a profile (109) on the edge side, which, when axially overlapping with the other non-return valve disk (69) in its stop position, provides a through-cross section (111) between the throttle channel (61) of the open non-return valve (61; 69) and the control chamber (45) of the main stage valve (23).

6. The adjustable damping valve device (1) according to claim 5, characterized in that: The profiled portion (119) of the check valve disc is a guide profiled portion of the check valve disc on the main stage valve body.

7. The adjustable damping valve device (1) according to claim 6, characterized in that: Two non-return valve discs (67; 69) are centered on guide pins (47) of the main stage valve body (37).

8. The adjustable damping valve device (1) according to claim 6, characterized in that: The main stage valve body (37) has an axial stop (119) for limiting the lifting of the check valve disc (67).

9. The adjustable damping valve device (1) according to claim 7 or 8, characterized in that: The axial stop (119) is formed by a guide pin (49) of the main stage valve body (37).

10. The adjustable damping valve device (1) according to claim 1, characterized in that: The non-return valve assembly with the non-return valve disk (67; 69) and the throttle channel (47; 61) has a separate stop disk (125).

11. The adjustable damping valve device (1) according to claim 10, characterized in that: The stop disk (125) is arranged on the main stage valve body (37).

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