Adjustable damping valve device for a vibration damper

Abstract

An adjustable damping valve device for a vibration damper, comprising a damping valve housing in which a pilot valve is arranged for hydraulically controlling a main stage valve, wherein the damping valve housing is hydraulically connected to a piston rod-side and a piston rod-remote working chamber of a working cylinder of the vibration damper, wherein the damping valve device has at least four check valves for rectifying a control volume flow of the pilot valve, wherein each check valve releases a control volume flow inflow from one of the working chambers to the pilot valve and each check valve releases a control volume flow outflow from the pilot valve into one of the two working chambers, wherein the damping valve housing comprises a valve housing ring having a channel system for the control volume flow outflow from the pilot valve into at least one of the two working chambers,wherein the two check valves switching the control volume flow outflow have a common check valve ring as a stationary valve body, separate from the valve housing ring.

Description

The invention relates to an adjustable damping valve device for a vibration damper according to the preamble of claim 1.DE 44 18 972 A1 relates to an adjustable damping valve device which comprises a valve housing on a piston rod of a vibration damper. The functional advantage of this damping valve device consists in the use of a single pre-stage valve for controlling a main stage valve in the event of an inflow proceeding from a working space on the piston rod side and from a working space remote from the piston rod.For this purpose, the damping valve device has a total of four check valves which are designed for rectifying a volume flow starting from the working chamber on the piston rod side and the working chamber remote from the piston rod to the pre-stage valve and for the outflow from the back chamber of the pre-stage valve to the two working chambers. The check valves which switch the inflow are embodied on or in the main stage valve body. In the damping valve device according to DE 10 2015 218 292 A1 and EP 0 364 757 A2, this rectification principle for the pre-stage valve is likewise implemented.The check valves which switch the outflow from the return chamber are each arranged at the end side on a valve housing ring. Within the valve housing ring, the main stage valve body slides within a tubular main stage valve body which additionally forms a longitudinal section of a return path body for the magnetic actuator. This results in an overall complex valve structure which was charged for the sake of a simpler damping valve device according to DE 198 22 448 A1, wherein this damping valve device only has a pilot valve function when there is an inflow starting from the working chamber on the piston rod side.The object of the present invention is to realize a damping valve device having a pre-stage valve which acts for both working directions of the vibration damper, wherein the structural design of the damping valve device is to be simplified in comparison with the prior art.The object is achieved by the features of claim 1.The check valve ring enables simplified component boundaries, so that essential components of the damping valve device can be made simpler and more robust. Furthermore, both check valves switching the control volume flow outlet can be arranged close to the pre-stage valve, so that only low throttle resistances can become effective for the damping medium until the two check valves are reached.During assembly, the check valve ring only has to be threaded onto the valve housing ring.According to an advantageous dependent claim, the check valve ring centers itself on the valve housing ring.For a simple flow guidance of the damping medium proceeding from the pre-stage valve, the check valve ring has an annular trench which in turn has connection openings to the channel system in the valve housing ring.Furthermore, the check valve ring has an annular connecting channel to a back chamber of the pre-stage valve. During assembly, care does not have to be taken to mount the check valve ring in a position-oriented manner in the circumferential direction.As a further measure for a simple flow guidance, the connecting channel is connected to the annular trench via at least one radial channel. Due to the open channel guidance within the check valve ring, it can be designed very easily as a sintered component.With regard to a simple embodiment of the check valves, the check valve ring is equipped on both sides with at least one check valve disk.Preferably, the at least one check valve disk centers itself on the valve housing ring. As a result, the check valve disk can be made larger in cross section than if the check valve disk were to be centered on the check valve ring. In addition, the geometry of the check valve ring is simplified, since no centering region is necessary.The check valve ring preferably comprises a cover ring, by means of which the check valve ring is axially fixed within the damping valve housing. As a result, the internal geometry of the damping valve housing can be kept simple.The cover ring also serves for the flow guidance, in that the cover ring has at least one connecting channel for the connection between the return chamber of the pre-stage valve and the connection channel in the check valve ring.Like the check valve body, the cover ring also centers itself on the valve housing ring.In order to avoid misalignment errors of the components which form the check valves, the valve housing ring has a centering shoulder at least for the check valve ring, on which the cover ring and the check valve disks can also center.The simplified valve housing ring compared to the prior art offers the possibility that the valve housing ring forms the housing of the main stage valve, wherein a main stage valve body is guided in a sealed manner axially displaceably within the valve housing ring.The invention will be explained in more detail with reference to the following description of the figures.It shows: FIGS. 1 and 2 are sectional views of the damping valve device FIG. 3 shows a detailed illustration of the main stage valve body in relation to FIG. 3. 1 FIG. 4 shows a check valve ring to FIGS. 1 and 2 as an individual part FIG. 5 shows the check valve disk of FIGS. 1 and 2 as an individual part FIG. 6 shows a detailed illustration of the check valve arrangement of FIGS. 1 and. 2 FIGS. 7 and 8 show cover rings from FIG. 6 as individual partsFIGS. 1 and 2 show in different planes a section through an adjustable damping valve device 1 for a vibration damper 3, respectively. The damping valve housing 5 and thus also the damping valve device 1 can however also be arranged spatially outside the vibration damper 1 and be hydraulically connected, for example, via a pipe or hose connection.The damping valve device 1 comprises an electromagnetic actuator 11 with a magnetic coil 13 and an armature 15, which acts on the end side on a pre-stage valve body 17 of a pre-stage valve 19. The force of the magnet coil 13 acts against at least one restoring spring 21.The pre-stage valve 19 serves for the hydraulic control of a main stage valve 23, via which a working chamber 25 on the piston rod side and a working chamber 27 remote from the piston rod are connected to one another within the working cylinder 9. FIG. 1 shows radial connecting channels 29 within a valve housing ring 31 as a component of the damping valve housing 5, which connect the working chamber 25 on the piston rod side to the main stage valve 23. Between the working chamber 27 remote from the piston rod and the main stage valve 23, a passive damping valve 33; 35 is arranged for a respective flow direction of the damping valve device 1. The two passive damping valves 33; 35 are optionally used. Regardless of the working direction of the piston rod 7 within the vibration damper 3, the volume flow of the damping medium located in the working cylinder 9 that determines the damping force is displaced via the connection channels 29, the main stage valve 23 and the two passive damping valves 33; 35. Otherwise, a sealed piston 36 as a functional section of the damping valve housing 5 ensures a spatial separation of the two working spaces 25; 27.The main stage valve 23 includes a main stage valve body 37 and a main stage valve seat surface 39 (see FIG. 3 ) formed by a valve ring 41 inside the valve housing ring 31. Functionally, the main stage valve body 37 is constructed in two parts. A first functional section forms a closing body 37A, which, together with the main stage valve seat surface 39, determines the throttle cross section of the main stage valve 23. A second functional section is formed by a separating piston 37B, which is fixedly connected to the closing body 37A and consequently performs a synchronous displacement movement. The main stage valve body 37 is guided axially displaceably within a stage opening 43 of the valve housing ring 31. In this case, the separating piston 37B is sealed off from an inner lateral surface 43A of the stepped opening 43. The separating piston 37B, a part of the jacket surface 43A and a bottom 43B of the stepped opening 43 form a first control chamber 45. this first control chamber 45 is connected via at least one first throttle channel 47 to the radial connecting channels 29, wherein a pressure drop between the pressure in the connecting channels 29 and the first control chamber 45 is present as a result of the throttle function of the throttle channel 47.The separating piston 37B has a valve pin 49 which points in the direction of the pre-stage valve 19 and which has a pre-stage valve seat surface 51 for the pre-stage valve body 17 on the end side. The valve pin 49 is hollow and has at least one radial connection opening 53 to an axial channel 55 as part of the first control chamber 45 which has a second throttle channel 59 inside an intermediate wall 57 in the flow direction to the pilot valve 19. A second control chamber space 61 relative to the main stage valve body extends between the intermediate wall 57 and the pilot valve 19, and the radial connection opening can be designed as a throttle, so that a pressure difference is possible between the first and the second control chamber of the main stage valve body 37.At least one axial channel 63 runs within the closing body 37A of the main stage valve body 37, if required with a throttle function similar to the first throttle channel 47, which connects a connection chamber 65 of the damping valve device 1 to the first control chamber 45 and to the second control chamber 61, in that the at least one axial channel 63 opens into the axial channel 55 of the valve pin 49. Both the first throttle channel 47 and the axial channel 63 between the connection chamber 65 and the first control chamber 45 are equipped with a check valve 67; 69, which opens in the inflow direction into the first control chamber 45. As a result, a hydraulic short circuit of the pre-stage valve 19 via the first control chamber 45 is ruled out.By way of the stroke of the pre-stage valve body 17 from the pre-stage valve seat surface 51, a throttle cross section is defined which in turn determines the pressure level both in the first and in the second control chamber 45; 61. The pressures in the two control chambers 45; 61 multiplied by the axially pressurized surfaces on the separating piston 37B result in a closing force which acts on the main stage valve body 37 and which determines the damping force of the vibration damper 3 for a predefined working movement of the vibration damper 3.The damping medium that passes through the pre-stage valve 19 reaches a back space 71 of the pre-stage valve between the bottom of the valve housing ring 31 and the actuator 11, which is connected to a check valve arrangement 73 that comprises a check valve ring 75 that is equipped on both sides with at least one check valve disk 77; 79 (FIG. 5 ). The check valve ring 75 represents a component which is separate and replaceable from the valve housing ring 31. The check valve disks 77; 79 on both sides in combination with the check valve ring 75 form two check valves 81; 83 for controlling the control volume outflow from the pre-stage valve 19 into the two working chambers 25; 27 of the working cylinder 9. In the flow direction starting from the check valve arrangement 73 in the direction of the working chamber 25 on the piston rod side, the damping valve housing 5 has at least one, in this example, radial connecting opening 85. for the connection of the pre-stage valve 19 to the working chamber 27 remote from the piston rod, the valve housing ring 31 has a channel system 87 which opens into the connecting chamber 65. When the check valve arrangement 73 is supplied with flow starting from one of the two working spaces 25; 27, the check valve 81; 83 supplied with flow directly, i.e. bypassing the pre-stage valve 19, is closed.The check valve ring 75 is centered on the valve housing ring 31 via its central through-opening 89. As FIG. 4 shows, the check valve ring 75 has an annular groove 91 in the direction of the rear chamber 71, which groove in turn comprises axial connection openings 93 to the channel system 87 in the valve housing ring 31. The annular groove 91 is radially delimited by two annular supporting surfaces 95; 97 for the nonreturn valve disc 77. An inner support surface 97 is interrupted by at least one radial channel 99, which connects the annular trench 91 to a radially inner connection channel 101. The connection channel 101 is connected directly to the back chamber 71 of the pre-stage valve 19.The two check valve disks 77; 79 are also preferably centered on the valve housing ring 31. In principle, it would also be conceivable for at least one valve disk 77; 79 to be centered on the check valve ring 75. The check valve disks 77; 79 preferably have the basic design according to FIG. 5 with inner centering webs 103, which allow an unhindered flow of damping medium from the back chamber 71 into the connection channel 101.The downward stroke movement of the check valve disk 79 for the channel system 87 in the valve housing ring 31 is limited by the valve housing ring 31. A cover ring 103 serves for the downward stroke movement of the check valve disk 77 on the upper side of the check valve ring 75, which additionally axially fixes the check valve ring 75 within the damping valve housing 5. FIGS. 7 and 8 show the cover ring 103 as an individual part, which likewise has at a central passage opening 105 at least one connecting channel 107 for the connection between the rear chamber 71 of the pre-stage valve 19 and the connection channel 101 in the check valve ring 75. The cover ring 103 is also centered on the valve housing ring 31, which for this purpose has a central centering projection 109, on which the check valve ring 75 and the check valve disks 77; 79 are also centered. For limiting the lifting movement of the check valve disk 77, a support surface 111 of the cover ring 103 is used.When the damping valve device 1 is supplied with an inflow proceeding from a compression of the working chamber 27 remote from the piston rod, the damping medium passes the passive damping valve 35 and ensures, within the connection chamber 65, a pressurization of the main stage valve body 37 within a pressurization surface bounded by the main stage valve seat surface 39. A control volume flow reaches the first control chamber 45 via the axial channel 63 and via the opened check valve 69, and further reaches the second control chamber 61 via the connection opening 53. The control volume flow flows via the pre-stage valve 19 and the non-return valve disk 77, which is lifted from the non-return valve ring 75, through the connecting opening 85 into the working chamber 25 on the piston rod side.The damping medium acting on the nonreturn valve 83 via the duct system 87 in the valve housing ring 31 closes this nonreturn valve 83, and the nonreturn valve 67 in the separating piston 37B of the main stage valve body 37 is also closed in this inflow situation of the damping valve device 1.When the damping valve device 1 is supplied with flow from the working chamber 25 on the piston rod side, the displaced damping medium abuts an 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 which extends inside the lateral surface 43A of the valve housing ring 31. This pressing force also causes a lift-off force to act on the main stage valve body. Hydraulically in parallel, the first control chamber 45 is also pressurized via the first throttle channel 47, whereupon a pressure increase is also established in the second control chamber 61, which pressure increase, together with the pressure increase in the first control chamber 45, brings about a closing force on the main stage valve body 37. The control volume flow flowed out into the rear chamber 71 through the pre-stage valve 19 then likewise reaches the connection channel 101, reaches the annular trench 91 via the at least one radial channel 99 and can then flow out into the connection chamber 65 via the connection openings 93 in combination with the channel system 87 and then further through the passive damping valve 33 into the working chamber 27 remote from the piston rod. Here, too, the check valve 81 is closed in the direction of the piston rod-side working chamber 25 by the opposite inflow from the piston rod-side working chamber 25, so that by using the total of four check valves 67; 69; 81; 83 used, rectification of the control volume flow by the pre-stage valve 19 is achieved.Reference numerals denote reference numerals1 Adjustable damping valve device 3 Vibration damper 5 Damping valve housing 7 Piston rod 9 Working cylinder 11 Actuator 13 Solenoid 15 Armature 17 Pilot stage valve body 19 Pilot stage valve 21 Restoring spring 23 Main stage valve 25 Piston rod-side working chamber 27 Piston rod-remote working chamber 29 Radial connecting passage 31 Valve housing ring 33 Passive damping valve 35 Passive damping valve 37 Main stage valve body 37A Closing body of the main stage valve body 37B Separating piston of the main stage valve body 39 Main stage valve seat surface 41 Valve ring 43 Stage opening of the valve housing ring 43A Lateral surface of the stage opening 43B Base of the stage opening 45 First control chamber 47 First throttle passage 49 Valve pin 51 Pilot stage valve seat surface 53 Connecting opening 55 Axial passage 57 Intermediate wall 59 Second throttle passage 61 Second control chamber 63 Axial passage 65 Connecting chamber 67 Nonreturn valve 69 Nonreturn valve 71 Rear chamber 73 Nonreturn valve arrangement 75 Nonreturn valve ring 77 Nonreturn valve disk 79 Nonreturn valve disk 81 Nonreturn valve 83 Nonreturn valve 85 Connecting opening 87 Channel system 89 Passage opening 91 Annular trench 93 Connecting opening 95 Supporting surface 97 Supporting surface 99 Radial channel 101 Connecting channel 103 Cover ring 105 Passage opening 107 Axial connecting channel 109 Centring shoulder 111 Supporting surface

Claims

Adjustable damping valve device (1) for a vibration damper (3), comprising a damping valve housing (5) in which a preliminary stage valve (19) for the hydraulic control of a main stage valve (23) is arranged, wherein the damping valve housing (5) is hydraulically connected to a working chamber (25; 27), on the piston rod side and remote from the piston rod, of a working cylinder (9) of the vibration damper (3), wherein the damping valve device (1) has at least four check valves (67; 69; 81; 83) for rectifying a control volume flow of the preliminary stage valve (19), wherein in each case one check valve (67; 69) has a control volume inflow proceeding from one of the working chambers (25; 27) to the preliminary stage valve (19) and in each case one check valve (81; 83) has a control volume flow outflow from the preliminary stage valve (19) into one of the two working chambers (25; 27), wherein the damping valve housing (5) comprises a valve housing ring (31) which has a channel system (87) for the control volume flow outflow from the pre-stage valve (19) into one of the two working spaces (25; 27), characterized in that the two check valves (81; 83) which switch the control volume flow outflow have, as a stationary valve body, a common check valve ring (75) which is separate from the valve housing ring (31) and is supported axially on the valve housing ring (31).Adjustable damping valve device (1) according to Claim 1, characterized in that the nonreturn valve ring (75) is centred on the valve housing ring (31).Adjustable damping valve device (1) according to one of Claims 1 or 2, characterized in that the nonreturn valve ring (75) has an annular trench (91) which has connection openings (93) to the duct system (87) in the valve housing ring (31).Adjustable damping valve device (1) according to one of Claims 1 to 3, characterized in that the nonreturn valve ring (75) has an annular connecting duct (101) to a rear space (71) of the preliminary stage valve (19).Adjustable damping valve device (1) according to Claim 4, characterized in that the connecting duct (101) is connected to the annular trench (91) via at least one radial duct (99).Adjustable damping valve device (1) according to one of Claims 1 to 5, characterized in that the nonreturn valve ring (75) is fitted on both sides with at least one nonreturn valve disc (77; 79).Adjustable damping valve device (1) according to Claim 6, characterized in that the at least one nonreturn valve disc (77; 79) is centred on the valve housing ring (31).Adjustable damping valve device (1) according to one of Claims 1 to 7, characterized in that the nonreturn valve ring (75) comprises a cover ring (103), by means of which the nonreturn valve ring (75) is axially fixed within the damping valve housing (5).Adjustable damping valve device (1) according to Claim 8, characterized in that the cover ring (103) has at least one connecting duct (107) for the connection between the rear space (71) of the pre-stage valve (19) and the connection duct (101) in the check valve ring (75).Adjustable damping valve device (1) according to Claim 8 or 9, characterized in that the cover ring (103) is centred on the valve housing ring (31).Adjustable damping valve device (1) according to one of Claims 1 to 10, characterized in that the valve housing ring (31) has a centring shoulder (109) at least for the nonreturn valve ring (75).Adjustable damping valve device (1) according to one of Claims 1 to 11, characterized in that the valve housing ring (31) forms the housing of the main stage valve (23), a main stage valve body (37) being guided in a sealed manner axially displaceably within the valve housing ring (31).

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