Damping valve device for a shock absorber of a motor vehicle

Abstract

comprising a damping valve device (54a,b,c) for a vibration damper (10) of a motor vehicle, a main valve (68) with a main piston (76; 120) that separates a main control chamber (82; 118) and a pilot chamber (84; 122) from each other, wherein the main control chamber (82; 118) and the pilot control chamber (84; 122) are fluidically connected to each other via a flow passage (86, 136), characterized in that the damping valve device (54a, b) has a sealing element (106) which is designed and arranged such that it seals the main piston (76) to a housing part (80) of the main valve (68), wherein a recess (118) is formed in the main piston (76) and the sealing element (106) is arranged within the recess (118), wherein the recess (118) is formed on a section of the main piston (76) with a continuously tapered outer diameter and wherein the sealing element (76) bears at least partially against the tapered section of the main piston.

Description

[0001] The invention relates to a damping valve device for a shock absorber for motor vehicles, wherein the damping valve device comprises a main valve and a pilot valve.

[0002] DE 10 2020 201 457 A1 discloses a vibration damper with a damping valve assembly having a pilot-operated main valve. DE 10 2020 202 848 A1 discloses an adjustable damping valve assembly for a vibration damper with a main stage valve and a pilot valve, to which an emergency operating valve is functionally connected in series. DE 10 2007 005 288 A1 also discloses a hydraulic vibration damper that has a controllable control valve module with a main valve and a pilot valve assembly, wherein the pressure acting on the main valve can be varied by the pilot valve module. DE 11 2014 005 430 T5 discloses a shock absorber with a damping valve in the main piston, wherein the damping valve has a pilot chamber for setting a pilot pressure.WO 2013 / 068 181 A1 describes a valve assembly for a vibration damper, which also includes a pilot-operated main valve. DE 10 2020 215 480 A1 discloses a vibration damper with a damping valve assembly, which includes a main valve and a pilot valve adjustable via a solenoid coil. Leaks frequently occur, particularly in the pilot chamber of the main valve, allowing hydraulic fluid to flow from the pilot chamber into the low-pressure chamber. Seals for the pilot chamber are already known in the art, but these are very complex to manufacture and install, and therefore expensive. Furthermore, the sealing performance requirements of known seals are not always met, especially under different operating conditions of the vibration damper, and wear-related failure is also common with known seals.

[0003] The object of the present invention is therefore to provide a damping valve device for a vibration damper which has a reliable seal, in particular of the hydraulic chambers of the main valve and the pilot valve, which can be manufactured and assembled cost-effectively.

[0004] This problem is solved according to the invention by a damping valve device with the features of independent device claim 1. Advantageous further developments are described in the dependent claims.

[0005] According to a first aspect, a damping valve assembly for a vibration damper of a motor vehicle comprises a main valve with a main piston that fluidically separates a main control chamber and a pilot chamber from each other.

[0006] The damping valve assembly is, for example, a pressure relief valve, which can preferably be directly controlled or pilot-operated. The main valve with the main piston is preferably designed to close and open the damping valve assembly, in particular the pressure relief valve. The main piston is preferably axially movable by means of the armature and / or the hydraulic pressure applied in the pilot chamber.

[0007] A damping valve device designed as a pilot-operated pressure relief valve preferably comprises, in addition to the main valve, a pilot valve with a pilot working chamber and a sliding plunger arranged in the pilot working chamber, which is axially movable by means of the armature, and a connecting channel which is arranged between the pilot chamber and the pilot working chamber and fluidically connects them.

[0008] For example, the pilot valve has a valve seat against which the sliding plunger rests in a closed position of the pilot valve, so that the connecting channel is fluid-tightly sealed by the sliding plunger. The damping valve assembly has a sealing element that is designed and arranged such that it seals the main piston to a housing part of the main valve, in particular in a fluid-tight manner.

[0009] According to the inventors, leakage occurs between the housing part and the main piston, so a sealing element between these components reliably prevents a leakage flow between the pilot chamber and the valve outlet.

[0010] Furthermore, a recess is formed in the main piston and the sealing element is arranged within the recess, wherein the recess is formed on a section of the main piston with a continuously tapered outer diameter and wherein the sealing element at least partially rests against the tapered section of the main piston.

[0011] The main piston is preferably movable relative to the housing part in the axial direction of the damping valve assembly. In particular, the sealing element is movably mounted relative to the main piston and / or the housing part. The sealing element is, for example, arranged between the inside of the housing part and the outside of the main piston. Specifically, the sealing element bears against the radially outward-facing outer surface of the main piston and the radially inward-facing inner surface of the housing part. The sealing element preferably extends radially between the main piston and the housing part. Preferably, the main piston and the housing part are radially spaced apart, with the sealing element being located within this radial space. The sealing element is preferably annular, and in particular circular.For example, the sealing element comprises two concentrically and coaxially arranged ring sections, whereby the inner ring section can also be designed with interruptions, different diameters, and each, for example, a square, triangular, or, in particular, rectangular cross-section. Modified geometries and cross-sections such as polygons and rounded corners are also possible.

[0012] The damping valve assembly is, for example, arranged in a vibration damper for a motor vehicle. The vibration damper is, for example, a single-tube vibration damper or a multi-tube vibration damper, such as a twin-tube vibration damper. The vibration damper comprises, for example, an outer tube that forms an outer surface, in particular a housing, of the vibration damper. An inner tube, also referred to as a damper tube, is arranged coaxially within the outer tube. A compensating chamber is formed between the outer tube and the inner tube, which is preferably at least partially filled with a hydraulic fluid. For example, the compensating chamber is partially filled with a gas.

[0013] Preferably, a working piston connected to a piston rod is arranged within the inner tube such that it is movable within the inner tube, the inner tube preferably serving as a guide for the working piston. A damping valve device according to the invention is, for example, arranged on the working piston. The working piston divides the interior of the inner tube, in particular, into a first working chamber on the piston rod side and a second working chamber further away from the piston rod.

[0014] The damping valve assembly is, for example, at least partially arranged outside the outer tube of the vibration damper. With such an external arrangement of the damping valve assembly, a central tube is optionally arranged coaxially to and between the inner and outer tubes within the compensation chamber. The damping valve assembly is, for example, attached to the central tube. The central tube is preferably fluid-tightly attached to the inner tube, with an annular space formed between the central tube and the inner tube. The central tube preferably has a flanged section for attaching the damping valve assembly to the central tube, which preferably forms a fluid inlet and / or fluid outlet for the damping valve assembly. The outer tube preferably has an opening aligned with the flanged section for receiving the damping valve assembly, so that the damping valve assembly is fluidly connected to the compensation chamber.For example, the vibration damper has a further damping valve assembly, which is also arranged outside the outer tube. Preferably, the further damping valve assembly is fluidically connected to the inner tube, in particular to the working chamber furthest from the piston rod, by means of an adapter located inside the inner tube. The damping valve assemblies are preferably identical.

[0015] The vibration damper preferably has a sealing assembly that fluidly seals the interior of the outer tube on the piston rod side. Opposite the sealing assembly, at the end furthest from the piston rod, the interior of the outer tube is preferably fluidly sealed by means of a bottom piece. A bottom valve is particularly well-proportioned on the bottom piece and is attached to the end of the inner tube furthest from the piston rod.

[0016] The damping valve assembly comprises a preferably cylindrical damping valve housing, which has a substantially tubular tube section and a housing top attached to the tube section. The housing top section has, for example, a connection area with one or more connection contacts for supplying electrical power to the damping valve assembly. Preferably, the connection contacts for the electrical power supply are connected to a drive unit. The housing top section has, for example, a circular cylindrical cover section to which a hollow cylindrical section, which has, for example, a smaller diameter, is attached.

[0017] The damping valve device preferably has an actuator designed as an electromagnet, in particular a coil with a plurality of windings made of a current-conducting wire. The coil is preferably arranged within a housing of the damping valve device and comprises, for example, a coil carrier on which the windings of the coil are wound. Preferably, the coil at least partially or completely encloses an armature chamber that extends centrally in the axial direction. An armature is preferably mounted axially movable within the armature chamber. The armature is preferably mounted so as to slide axially within the armature chamber and comprises, for example, a central armature rod, which is exemplary tubular in shape and extends centrally in the axial direction through the armature chamber.The armature chamber is preferably limited by a pole tube that is at least partially hollow and cylindrical, and which preferably serves as a guide for the armature.

[0018] The damping valve assembly preferably comprises a main valve and optionally a pilot valve, and in particular a valve inlet for introducing hydraulic fluid into the damping valve assembly and a valve outlet for releasing hydraulic fluid from the damping valve assembly. The pilot valve is preferably arranged downstream of the main valve. In particular, the damping valve assembly is designed to allow hydraulic fluid to flow through it in only one direction.

[0019] The main valve preferably comprises a main piston that is axially movable within a main working chamber. The main valve includes a housing part that at least partially delimits the main working chamber and provides axial guidance for the main piston. The main piston is preferably arranged to separate a main control chamber and a pilot chamber, the main piston optionally having a flow passage extending through it and forming a fluidic connection between the main control chamber and the pilot chamber. Optionally, the pilot chamber is fluidically connected to the first or second working chamber of the vibration damper via a flow passage. The housing part is, for example, hollow cylindrical and includes, for example, the valve inlet or the valve outlet.Preferably, the housing part encloses the main valve, in particular the main piston, the main working chamber with the main control chamber and the pilot chamber at least partially or completely in the axial direction and / or in the circumferential direction.

[0020] For example, the main piston is designed such that the end face of the main piston facing the main control chamber, which is subjected to the hydraulic pressure of the main control chamber, is larger than the end face of the main piston facing the pilot chamber, which is subjected to the hydraulic pressure of the pilot chamber.

[0021] During operation of the damping valve assembly, particularly a pilot-operated or direct-operated pressure relief valve, the hydraulic fluid flows through the valve inlet into the main control chamber. The pressure in the main control chamber exerts an opening force on the main piston, causing it to move axially in the opening direction. The main piston lifts off the main valve seat, and the hydraulic fluid flows through the main flow channel to the valve outlet. Simultaneously, a partial flow of the hydraulic fluid passes through the flow passage in the main piston to the pilot chamber, exerting a closing force on the main piston towards the main valve seat. This closing force determines the opening width of the main valve, specifically the cross-section of the main flow channel, which in turn determines the damping force of the damping valve assembly.

[0022] In a pilot-operated pressure relief valve, the closing force is preferably determined by the pressure in the pilot chamber. The pressure in the pilot chamber is set, in particular, by the pilot valve, whereby the hydraulic fluid flows from the pilot chamber through the connecting channel into the pilot working chamber, which is opened by the sliding plunger. The opening width of the connecting channel depends on the axial position of the sliding plunger, which is set, in particular predetermined, by means of a solenoid coil.

[0023] In a directly controlled pressure relief valve, the closing force of the main piston is preferably determined by the pressure in the pilot chamber and / or by means of the solenoid coil. For example, the main piston is directly connected to the armature, so that the armature exerts a force on the main piston in the axial direction, particularly in the closing direction. The directly controlled pressure relief valve preferably does not have a pilot valve.

[0024] In an external damping valve assembly arranged outside the outer tube, the valve inlet is formed, in particular, in a flange region of the damping valve assembly, wherein the flange region is preferably connected to an outer tube, inner tube, and / or central tube of the vibration damper. The main valve preferably has a main valve seat, which is formed, for example, on the flange region and on which the main piston rests fluid-tight in the closed position of the main valve. In the open position of the main valve, in which the main piston is lifted axially from the main valve seat, a main flow channel is preferably formed between the main piston and the valve seat. The main flow channel preferably forms a fluid connection between the valve inlet, in particular the main control chamber, and the valve outlet.

[0025] A spring element is preferably attached to the side of the main piston facing away from the valve seat, arranged such that it exerts a spring force on the main piston in the direction of the main valve seat. The spring element is, for example, a preload spring with one or at least two spring disc assemblies, the spring disc assemblies preferably being circular disc-shaped, particularly as a disc spring.

[0026] The damping valve assembly, in particular a pilot-operated pressure relief valve, preferably comprises a connecting channel for linking the pilot chamber to a pilot working chamber of the pilot valve. The connecting channel is preferably formed in a housing part or in a region fixed to the housing of the damping valve assembly and extends, in particular, centrally and axially. Preferably, the connecting channel forms the fluid inlet to the pilot valve.

[0027] The pilot valve preferably comprises a sliding plunger that is axially movable within the pilot working chamber. The sliding plunger preferably rests against the armature at its end furthest from the main valve, so that the movement of the armature and the sliding plunger are mechanically coupled, at least in the direction of pull. The pilot valve is preferably movable into a closed position in which the sliding plunger rests against a first valve seat of the pilot valve such that the connecting channel is completely closed by the sliding plunger, so that preferably no fluid flow can pass through the connecting channel into the pilot working chamber. The pilot valve is preferably movable into an open position in which the sliding plunger is lifted from the first valve seat of the pilot valve, so that the connecting channel is opened by the sliding plunger and a fluid flow occurs between the pilot chamber of the main valve and the pilot working chamber.For example, the pilot valve has a fluid channel for the fluidic connection of the pilot working chamber to the valve outlet. The pilot working chamber is preferably fluidically connected to a flow channel through which the hydraulic fluid can flow from the pilot working chamber into a valve outlet, in particular into the first or second working chamber.

[0028] Optionally, the pilot valve includes a preload element arranged and configured to apply a preload force to the slide plunger. This preload element is, for example, a coil spring or a helical spring, arranged and configured to apply a preload force to the slide plunger in the direction of the armature. Preferably, the preload element, which may be a coil spring, flat spring, and / or helical spring, is arranged coaxially with the slide plunger. Such a preload element increases operational reliability and ensures that the slide plunger is reliably moved in the direction of the armature and thus reaches the failsafe position in a de-energized operating state.

[0029] According to a first embodiment, the sealing element has an elastic preload. Preferably, the sealing element is preloaded by means of the hydraulic pressure, in particular the hydraulic pressure present in the pilot chamber, and preferably subjected to a radial outward force. The sealing element is preferably arranged in an elastically deformed state between the housing part and the main piston. Such a state ensures optimal sealing.

[0030] According to a further embodiment, the sealing element has a total cross-section comprising at least two distinct cross-sectional areas. By way of example, the sealing element has a total cross-section comprising at least or exclusively two cross-sectional areas.

[0031] According to a further embodiment, the first cross-sectional area has a larger cross-sectional area than the second. In particular, the first and second cross-sectional areas are each substantially quadrilateral, especially rectangular. The overall cross-section of the sealing element preferably comprises at least one rounded area, which is preferably formed between the first and second cross-sectional areas, particularly at the transition from the first to the second. The first cross-sectional area is, for example, a radially outer cross-sectional area that extends, for example, in the axial direction beyond the second cross-sectional area. The second cross-sectional area is preferably a radially inner cross-sectional area that extends in the radial direction, particularly from the first cross-sectional area to the outer surface of the main piston.

[0032] In the elastically prestressed state of the sealing element, the second cross-sectional area is preferably elastically deformed. In particular, the second cross-sectional area is elastically deformed such that its end face points towards the spring element or the pilot valve. Preferably, the second cross-sectional area is elastically deformed such that the first cross-sectional area is subjected to a force directed radially outwards, particularly towards the housing part.

[0033] According to a further embodiment, the overall cross-section of the sealing element has a symmetrical profile. In particular, the overall cross-section is symmetrical or asymmetrical with respect to an axis of symmetry running radially through the center of the overall cross-section. Specifically, the overall cross-section has a T-shaped profile. A sealing element with a symmetrical profile is easy and inexpensive to manufacture and can be installed in the damping valve assembly.

[0034] According to a further embodiment, the first cross-sectional area rests against the housing part and the second cross-sectional area against the main piston. The first cross-sectional area rests, for example, against the housing part with one side surface. The housing part is preferably stationary within the damping valve assembly, with the main piston being movably mounted relative to the housing part. The second cross-sectional area preferably rests against the main piston with one side surface. Preferably, the first cross-sectional area, with its side surface opposite the housing part, also rests at least partially against the main piston. The overall cross-section of the sealing element is preferably designed such that it tapers from the housing part towards the main piston, in particular continuously or in steps. The sealing element is preferably formed in one piece.

[0035] A recess is formed in the main piston, and the sealing element is arranged within this recess. The recess preferably extends circumferentially and radially inwards from the outer surface. In particular, the recess is formed at the end region of the main piston facing the spring element. The recess is preferably located between the main piston and the housing part, with the sealing element positioned within the recess. For example, starting from the end of the main piston on the spring element side and extending towards the main control chamber, the recess comprises a section with a constant outer diameter of the main piston and a subsequent section with a continuously increasing outer diameter of the main piston.

[0036] The recess is formed on a section of the main piston with a continuously tapered outer diameter, with the sealing element bearing at least partially against the tapered section of the main piston. The sealing element preferably bears at least partially against the section of the main piston with a continuously changing outer diameter, particularly one that tapers towards the pilot valve. The main piston preferably has a first section with a constant outer diameter in the axial direction, which preferably abuts the inner diameter of the housing part. The end region of the main piston on the spring element side preferably has a second section with a constant outer diameter in the axial direction, which is smaller than the outer diameter of the first section.Preferably, a section with a continuously decreasing outer diameter is formed directly between the first and second sections, against which the sealing element in particular rests.

[0037] During operation of the damping valve device, the pressure of the pilot chamber is preferably applied to the area of ​​the sealing element pointing towards the pilot valve and exerts a hydraulic force on the sealing element, causing it to deform elastically, for example, so that it fits flush against the main piston, in particular the section with the tapered outer diameter, thus forming an optimal seal between the main piston and the pipe section.

[0038] According to another embodiment, the sealing element is movably mounted within the recess. Preferably, the sealing element is movable relative to the main piston and / or housing part.

[0039] According to another embodiment, the sealing element is arranged within the pilot chamber of the main valve.

[0040] According to a further embodiment, the sealing element is subjected to a radial preload force. This ensures optimal sealing in every position of the sealing element. Preferably, the overall cross-section of the sealing profile has a radial width that is greater than the width of the recess, in particular greater than the radial distance between the main piston and the housing part.

[0041] According to a further embodiment, the sealing element is manufactured by a machining process, in particular turning. The sealing element is preferably made of polytetrafluoroethylene (PTFE) or an elastically deformable material. In particular, the sealing element is designed and arranged such that the second cross-sectional area is elastically deformable relative to the first cross-sectional area. For example, the second cross-sectional area has a lower modulus of elasticity than the first cross-sectional area. Alternatively, both cross-sectional areas may have the same modulus of elasticity. Due to the geometry, preferably one cross-sectional area is more elastically deformable than the other.

[0042] According to a further embodiment, the damping valve device comprises a coil and an axially movable armature, which is at least partially arranged inside the coil, a pilot valve with a pilot working chamber and a sliding plunger arranged in the pilot working chamber, which is axially movable by means of the armature, and a connecting channel that is arranged between the pilot chamber and the pilot working chamber and fluidically connects them.

[0043] According to another embodiment, the damping valve device comprises a coil and an axially movable armature, which is at least partially arranged inside the coil, wherein the armature is connected to the main piston so that it exerts a closing force on it.

[0044] The invention also includes a vibration damper with a damping valve device described above, wherein the damping valve device is arranged, for example, on the working piston and / or at least partially outside the outer tube. Description of the drawings

[0045] The invention is explained in more detail below with reference to several exemplary embodiments and the accompanying figures. Fig. Figure 1 shows a schematic representation of a vibration damper in a longitudinal sectional view according to an exemplary embodiment. Fig. Figure 2 shows a schematic representation of a damping valve device in a longitudinal section view according to a further embodiment. Fig. Figure 3 shows a schematic representation of a section of the damping valve assembly in a longitudinal section view according to a further embodiment.

[0046] Fig. Figure 1 shows a vibration damper 10, wherein the vibration damper 10 is a multi-tube vibration damper, for example a 2-tube vibration damper. The vibration damper 10 has an outer tube 12, which forms an outer surface, in particular a housing, of the vibration damper 10. Inside the outer tube 12, an inner tube 14, which can also be referred to as a damper tube, is arranged coaxially to it. A compensation chamber 16 is formed between the outer tube 12 and the inner tube 14, which is preferably at least partially filled with a hydraulic fluid. For example, the compensation chamber 16 is partially filled with a gas.

[0047] Within the inner tube 14, a working piston 18 connected to a piston rod 20 is arranged such that it is movable within the inner tube 14, the inner tube preferably serving as a guide for the working piston 18. The working piston 18 may, for example, have a valve assembly (not shown). The working piston 18 divides the interior of the inner tube 14 into a first working chamber 22, located towards the piston rod, and a second working chamber 24, located further away from the piston rod. Within the compensation chamber 16, a central tube 26 is arranged coaxially to and between the inner tube 14 and the outer tube 12.

[0048] The interior of the outer tube 12 is fluidly sealed on the piston rod side by means of a sealing assembly 34. Opposite the sealing assembly 34, at the end furthest from the piston rod, the interior of the outer tube 12 is fluidly sealed by means of a bottom piece 36. A bottom valve 38 is arranged on the bottom piece 36, for example, and is preferably attached to the end of the inner tube 14 furthest from the piston rod. The bottom valve 38 is, for example, a check valve that allows flow in both directions or only in one direction. The second working chamber 24 is preferably fluidly connected to the compensation chamber 16 via the bottom valve 38. The piston rod end of the inner tube 14 and the outer tube 12 is preferably attached to the sealing assembly 34.

[0049] The central tube 26 is preferably fluid-tightly attached to the inner tube 14. An annular space 28 is formed between the central tube and the inner tube 14. At least one passage opening 30 is formed in the inner tube 14, which fluidly connects the first working chamber 22 to the annular space 28.

[0050] The central tube 26 has, for example, a flange region 32 for attaching a damping valve assembly 54a to the central tube 26. The flange region 32 forms a receptacle for the damping valve assembly 54a; in particular, the flange region 32 forms a fluid inlet and / or fluid outlet of the damping valve assembly 54a. The flange region 32 connects, for example, the annular space 28 to the damping valve assembly 54a. The outer tube 12 preferably has an opening aligned with the flange region 32 for receiving the damping valve assembly 54a, so that the damping valve assembly 54a is fluidically connected to the compensation chamber 16.

[0051] The vibration damper 10 includes, by way of example, a further damping valve assembly 54b, which is fluidly connected to the inner tube 14, in particular to the working chamber 24 furthest from the piston rod, by means of an adapter 40 located inside the inner tube 14. Preferably, the outer tube 12 and the central tube 26 have openings aligned with the adapter for receiving the damping valve assembly 54a. The damping valve assemblies 54a, b are, by way of example, identical in design. For example, the damping valve assemblies 54a, b are designed as directly controlled or pilot-operated pressure relief valves.

[0052] The piston rod 20 has, by way of example, an optional pull stop which is subjected to a spring force via a spring element 42 during movement in the pull direction Z.

[0053] Fig. Figure 2 shows an exemplary damping valve assembly 54a, b, which is preferably arranged as an external valve at least partially outside the outer tube 12 of the vibration damper 10. The damping valve assembly 54a, b is exemplary designed as a pilot-operated pressure relief valve and comprises a preferably cylindrical damping valve housing which includes a Fig. Figure 1 shows a substantially tubular pipe section 45 and a housing upper part 44 attached to the pipe section 45. The housing upper part 44 has, for example, a connection area 46 which has one or more connection contacts for an electrical power supply to the damping valve device 54a, b. Preferably, the connection contacts for an electrical power supply are connected to a drive unit. The housing upper part 44 has, for example, a circular cylindrical cover section 56, to which a hollow cylindrical section 58 is attached, which, for example, has a smaller diameter.

[0054] The damping valve assembly 54a, b exemplarily comprises an actuator section 48 and a valve section 50. The actuator section 48 is exemplarily arranged in the upper region of the damping valve assembly 54a, b, facing the upper housing part 44, and preferably substantially above the valve section 50. The actuator section 48 preferably comprises an actuator designed as an electromagnet. The electromagnet comprises a coil 52 with a plurality of windings made of a current-conducting wire. The coil 52 is preferably arranged within the tube section 45 and concentrically to it. By way of example, the coil 52 is arranged within the hollow cylinder section 58 of the upper housing part 44 and is in particular in contact with the inner wall of the upper housing part 44.The upper housing part 44 is, for example, made of a plastic, in particular a non-magnetic or only very slightly magnetic material, preferably a magnetic insulator or a material with high magnetic resistance. The coil 52 comprises, for example, a coil support on which the windings of the coil are wound. The coil 52 at least partially or completely encloses an armature chamber 60, which extends centrally in the axial direction. An armature 62 is mounted axially movable within the armature chamber 60. The armature 62 is preferably cylindrical and has a diameter that is slightly smaller than the diameter of the armature chamber 60, so that the armature 62 is preferably mounted to slide axially. By way of example, the armature 62 comprises a central armature rod 65, which is, for example, tubular and extends centrally in the axial direction through the armature chamber 60.The armature chamber 60 is preferably bounded by a pole tube 64 that is at least partially hollow and cylindrical. The pole tube 64 preferably has a bottom and is, in particular, open in the direction of the valve area 50. The pole tube 64 is preferably made of a magnetizable or magnetic material and, for example, has a magnetic separation (not shown).

[0055] The coil 52 is preferably designed and arranged such that, when energized, it generates a magnetic field with magnetic field lines that preferably run substantially axially in the armature chamber 60. The armature 62 is preferably made of a magnetizable or magnetic material and is movable axially according to the polarity of the magnetic field generated by the coil 52.

[0056] A pole tube element adjoins the hollow cylindrical section of the pole tube 64 in the axial direction and coaxially thereto, together forming the pole tube 64, wherein the pole tube 64 is preferably designed as a multi-part, one-piece, or single-piece assembly. The pole tube 64 has an upper tubular section with a particularly constant inner diameter, which is preferably designed as a hollow cylinder and extends from the upper housing part 44 in the axial direction beyond the armature 62. A lower section with an enlarged diameter adjoins the upper hollow cylindrical section in the axial direction, wherein the outer surface of the pole tube 64 preferably extends to the Fig. Figure 1 shows the pipe section 45 extending and at least partially abutting it and being fluid-tightly sealed to the pipe section 45 by a sealing element 66. The pole tube 64 at least partially encloses a valve area 50, which will be explained in more detail in one of the following sections.

[0057] The valve assembly 50 includes, by way of example, a main valve 68 and a pilot valve 70, as well as a valve inlet 72 for admitting hydraulic fluid into the damping valve assembly 54a, b and a valve outlet 74 for discharging hydraulic fluid from the damping valve assembly 54a, b. During operation of the damping valve, the hydraulic fluid, in particular the pilot flow, preferably flows from the valve inlet 72 into the main valve 68, then into the pilot valve 70 and subsequently to the valve outlet 74. The main valve 68 includes a main piston 76, which is arranged to be axially movable within a main working chamber 78. The main valve 68 also includes, by way of example, a housing part 80, which at least partially delimits the main working chamber 78 and forms an axial guide for the main piston 76. The main piston 76 is preferably arranged within the housing part 80 and concentrically with it.The main piston 76 preferably divides the main working chamber 78 into a main control chamber 82 and a pilot chamber 84, wherein the main piston 76 in particular has a flow passage 86 which extends through the main piston 76 and forms a fluidic connection between the main control chamber 82 and the pilot chamber 84.

[0058] The valve inlet 72 is formed in particular in a flange region 88 of the damping valve assembly 54a, b, wherein the flange region 88 is preferably connectable to an outer tube 12, inner tube 14 and / or central tube 26 of the vibration damper 10. A main valve seat 90 is formed on the flange region 88, on which the main piston 76 rests fluid-tight in the closed position of the main valve 68. In the open position of the main valve 68, in which the main piston is moved axially away from the main valve seat 90, the main piston 76 is lifted from the main valve seat 90, so that a main flow channel 92 is formed between the main piston 76 and the main valve seat 90. The main flow channel 92 forms a fluid connection between the valve inlet 72, in particular the main control chamber 82, and the valve outlet 74.

[0059] The main piston 76 has a recess, particularly centrally located, on its surface facing the drive area 48, such that the main piston 76 has a hollow cylindrical section. The recess of the main piston 76, and in particular the interior of the hollow cylindrical section, preferably delimits the pilot chamber 84, at least partially. A spring element 94 is attached to the side of the main piston 76 facing away from the main valve seat 90, and is arranged such that it exerts a spring force on the main piston 76 in the direction of the valve seat 90. The spring element 94 is, for example, a preload spring with at least one or two spring disc assemblies, wherein the spring disc assemblies are preferably disc-shaped, in particular as a disc spring. The spring element 94 preferably extends over the entire diameter or a portion thereof of the pilot chamber 84, in particular to the inner wall of the housing part 80.

[0060] The spring element 94 preferably rests against a central block 96 that is fixedly connected to the housing part 80. The central block 96 is, for example, arranged in the pilot chamber 84 and is supported by or fixedly connected to the housing part 80. A connecting channel 98 is preferably formed in the central block 96 to connect the pilot chamber 84 with a pilot working chamber 100 of the pilot valve 70. The connecting channel 98 preferably extends centrally and axially through the central block 96. Preferably, the connecting channel 98 forms the fluid inlet to the pilot valve 70.

[0061] The pilot valve 70 includes, by way of example, a sliding plunger 102 which is arranged to be axially movable within the pilot working chamber 100. The sliding plunger 102 preferably rests against the armature 62 at its end facing away from the main valve 68, so that the movement of the armature 62 and the sliding plunger 102 are coupled, at least when the armature 62 moves in the direction of the sliding plunger 102. Preferably, in a closed position of the pilot valve 70, the sliding plunger 102 rests against the central block 96 such that the connecting channel 98 is completely closed by the sliding plunger 102. In an open position of the pilot valve 70, the sliding plunger 102 is lifted from the central block 96, so that the connecting channel 98 is opened by the sliding plunger 102 and a fluid flow occurs between the pilot chamber 84 of the main valve 68 and the pilot working chamber 100.The pilot valve 70 preferably has a pilot housing part 104, which is fixed in position and, for example, rests against or is rigidly connected to the housing part 80. The pilot working chamber 100 is formed within the pilot housing part 104, the inner wall of the pilot housing part forming a preferably fluid-tight contact surface with the sliding plunger 102. The pilot housing part 104 preferably forms an axial guide for the sliding plunger 102. The sliding plunger 102 has, for example, a T-shaped longitudinal section, wherein the sliding plunger 102 has a first region 103 facing the connecting channel 98 with a cross-section larger than the cross-section of the connecting channel 98, and a second region 105 facing the armature 62 with a larger cross-section than the first region. The second region preferably extends over the entire cross-section of the pilot working chamber 100.

[0062] The sliding plunger 102 of the pilot valve 70 preferably has at least one or a plurality of through-bores 112 extending axially through the sliding plunger 102 and forming a flow channel for hydraulic fluid through the sliding plunger 102. The through-bores 112 are preferably fluidically connected to the valve outlet 74, which is arranged downstream of the through-bores 112.

[0063] Fig. Figure 2 shows the pilot valve 70 in an exemplary closed position, with the sliding plunger 102 completely closing the connecting channel. Preferably, in the closed position, the sliding plunger 102 rests against a valve seat formed in the central block 96.

[0064] During operation of the damping valve assembly 54a, b, the hydraulic fluid flows through the valve inlet 72 into the main control chamber 82. The pressure in the main control chamber 82 exerts an opening force on the main piston 76, causing it to move axially upwards. The main piston 76 lifts off the main valve seat 90, and the hydraulic fluid flows through the main flow channel 92 to the valve outlet 74. Simultaneously, a partial flow of the hydraulic fluid flows through the flow passage 86 in the main piston 76 to the pilot chamber 84, exerting a closing force on the main piston in the direction of the main valve seat 90. This closing force determines the opening width of the main valve 68, and in particular the cross-section of the main flow channel 92, which determines the damping force of the damping valve assembly 54a, b.The pressure in the pilot chamber 84 is set by the pilot valve 70, whereby the hydraulic fluid flows from the pilot chamber 84 through the connecting channel 98 into the pilot working chamber 100, which is opened by the sliding plunger 102. The opening width of the connecting channel 98 depends on the axial position of the sliding plunger 102, which is set, and in particular predetermined, by means of a solenoid coil 54. In the closed position of the pilot valve 70, the sliding plunger 102 preferably closes the connecting channel 98 completely, so that the hydraulic pressure in the pilot chamber 84 rises to a maximum value and the main valve 68 is closed, in which the main piston 76 is pressed against the main valve seat 90.In an open position of the pilot valve 70, the connecting channel 98 is at least partially released by the sliding plunger 102, so that a hydraulic flow passes through the through-bores 112 in the sliding plunger 102 and flows via a flow channel arranged downstream of the through-bores 112 to the valve outlet 74.

[0065] Fig. Figure 3 shows a section of the damping valve assembly 54a, b of the Fig. 2, wherein identical elements are provided with the same reference numerals. The damping valve assembly 54a, b has a sealing element 106 which is designed and arranged such that it provides a fluid-tight seal between the main piston 76 and the housing part 80 of the main valve 68. The sealing element 106 is preferably annular, in particular circular. By way of example, the sealing element 106 comprises two concentrically and coaxially arranged ring sections with different diameters and each, for example, a square, in particular rectangular, cross-section.

[0066] By way of example, the sealing element 106 has an overall cross-section that comprises at least or exclusively two cross-sectional areas 108, 110. The first cross-sectional area 108 preferably has a larger cross-sectional area than the second cross-sectional area 110. In particular, the first cross-sectional area 108 and the second cross-sectional area 110 are each substantially quadrilateral, especially rectangular. By way of example, the overall cross-section of the sealing element has a symmetrical profile. In particular, the overall cross-section is symmetrical about an axis of symmetry running radially through the center of the overall cross-section. The overall cross-section of the sealing element 106 preferably includes at least one rounded area, which is preferably formed between the first cross-sectional area 108 and the second cross-sectional area 110, in particular at the transition from the first to the second cross-sectional area 108, 110.

[0067] The first cross-sectional area 108, for example, abuts the housing part 80 with one side surface. The housing part 80 is preferably stationary within the damping valve assembly 54a, b, with the main piston 76 being movably mounted relative to the housing part 80. The second cross-sectional area 110 preferably abuts the main piston 76 with one side surface. Preferably, the first cross-sectional area 108, with its side surface opposite the housing part 80, also abuts the main piston 76 at least partially. The overall cross-section of the sealing element 106 is preferably designed such that it tapers from the housing part 80 towards the main piston 76, in particular continuously or in stages. The sealing element 106 is preferably formed in one piece.

[0068] The sealing element 106 is preferably made of an elastically deformable material, such as polytetrafluoroethylene (PTFE). In particular, the sealing element 106 is designed and arranged such that the second cross-sectional area 110 is elastically deformable relative to the first cross-sectional area 108. For example, the second cross-sectional area 110 has a lower modulus of elasticity than the first cross-sectional area 108.

[0069] The main piston 76 has, by way of example, a recess 118. The recess 118 preferably extends circumferentially and radially inwards from the outer surface. In particular, the recess 118 is formed at the end region of the main piston 76 facing the spring element 94. The recess 118 is arranged between the main piston 76 and the housing part 80, with the sealing element 106 being located within the recess 118. By way of example, the recess 118 extends from the spring element-side end of the main piston 76 towards the main control chamber 82 through a section with a constant outer diameter of the main piston 76 and a subsequent section with a continuously increasing outer diameter of the main piston 76.

[0070] The sealing element 106 preferably rests at least partially against the section of the main piston 76 with a continuously changing outer diameter, in particular tapering towards the pilot valve.

[0071] Preferably, the sealing element 76 is arranged such that it seals the pilot chamber 84 from the valve outlet 74. During operation of the damping valve device 54a, b, the pressure of the pilot chamber 84 is preferably applied to the area of ​​the sealing element 106 facing the pilot valve 70 and exerts a hydraulic force on the sealing element 106, causing it to deform elastically, for example, so that it fits flush against the main piston, in particular the section with the tapered outer diameter, thus forming an optimal seal between the main piston and the pipe section 80.For example, even after wear or, in particular, temperature-dependent deformation, the sealing element is forced outwards against the housing by the hydraulic pressure of the pilot chamber, whereby the hydraulic pressure in the pilot chamber exerts a downward force on the sealing element 106 and, through the narrowing in the outer wall of the main piston 76, the sealing element is subjected to an axial, in particular in . Fig. 3 downward force is applied.

[0072] Fig.Figure 4 shows the sealing element in an installed, and in particular elastically prestressed, state, wherein the second cross-sectional area 110 is elastically deformed. For example, the second cross-sectional area 110 is elastically deformed such that its end face points towards the spring element 94 or the pilot valve 70. The elastic deformation of the second cross-sectional area 110 causes a prestressing of the first cross-sectional area 108 towards the inner wall of the housing part 80. Preferably, the second cross-sectional area 110 is elastically deformed such that the first cross-sectional area 108 is subjected to a force directed radially outwards, in particular towards the housing part 80. Reference symbol list 10 vibration dampers 12 Outer pipe 14 inner tube 16 compensation area 18 working pistons 20 piston rod 22 first / piston rod-side working space 24 second / piston rod-remote working space 26 center tube 28 annular space 30 Passage opening 32 Flange area 34 closure pack 36 bottom pieces 38 Bottom valve 40 adapters 42 Spring element 44 Housing top 45 pipe section 46 Connection area 48 Drive area 50 valve range 52 Coil 54a, b Damping valve device 56 Cover section 58 Hollow cylinder section 60 Anchor space 62 anchors 64 Polar tube 65 Anchor rod 66 Sealing element 68 Main valve 70 Pilot valve 72 Valve intake 74 Valve outlet 76 main pistons 78 Main workroom 80 Housing part 82 Main control room 84 Input tax room 86 Flow passage 88 Flange area 90 Main valve seat 92 Main flow channel 94 Spring element 96 Central Block 98 connection channel 100 pilot workspace 102 sliding plungers 103 first area of ​​the sliding plunger 104 Pilot housing part 105 second area of ​​the sliding plunger 106 Sealing element 108 first cross-sectional area 110 second cross-sectional area 112 Through hole 114 Recess in the main piston 118 recess

Claims

[1] comprising a damping valve device (54a,b,c) for a vibration damper (10) of a motor vehicle, a main valve (68) with a main piston (76; 120) that separates a main control chamber (82; 118) and a pilot chamber (84; 122) from each other, wherein the main control chamber (82; 118) and the pilot control chamber (84; 122) are fluidically connected to each other via a flow passage (86, 136), characterized by , that the damping valve device (54a, b) has a sealing element (106) which is designed and arranged such that it seals the main piston (76) to a housing part (80) of the main valve (68), wherein a recess (118) is formed in the main piston (76) and the sealing element (106) is arranged within the recess (118), wherein the recess (118) is formed on a section of the main piston (76) with a continuously tapered outer diameter and wherein the sealing element (76) bears at least partially against the tapered section of the main piston. [2] Damping valve device (54a, b) according to claim 1, wherein the sealing element (106) has an elastic preload. [3] Damping valve device (54a, b) according to claim 1 or 2, wherein the sealing element (106) has a total cross-section comprising at least two different cross-sectional areas (108, 110). [4] Damping valve device (54a, b) according to claim 3, wherein the first cross-sectional area (108) has a larger cross-sectional area than the second cross-sectional area (110). [5] Damping valve device (54a, b) according to one of the preceding claims, wherein the overall cross-section has a symmetrical, in particular T-shaped, shape. [6] Damping valve device (54a, b) according to one of claims 3 to 5, wherein the first cross-sectional area (108) is located on the housing part (80) and the second cross-sectional area (110) is located on the main piston (76). [7] Damping valve device (54a, b) according to the preceding claims, wherein the sealing element (76) is movably mounted within the recess (118). [8] Damping valve device (54a, b) according to one of the preceding claims, wherein the sealing element (76) is arranged within the pilot chamber (84) of the main valve (68). [9] Damping valve device (54a, b) according to one of the preceding claims, wherein the sealing element (76) is subjected to a radial preload force. [10] Damping valve device (54a, b) according to one of the preceding claims, wherein the sealing element (76) is manufactured by a machining process, in particular turning. [11] comprising a damping valve device (54a,b,c) according to one of the preceding claims a coil (52), an axially movable armature (62) which is arranged at least partially inside the coil (52), a pilot valve (70) with a pilot working chamber (100, 132) and a sliding plunger (102; 126) arranged in the pilot working chamber (100; 132), which is axially movable by means of the armature (62), and a connecting channel (98; 130) which is arranged between the pre-control room (84; 122) and the pilot work room (100; 132) and connects them fluidically. [12] comprising a damping valve device (54a,b,c) according to any one of claims 1 to 11 a coil (52), an axially movable armature (62) which is at least partially arranged inside the coil (52), wherein the armature (62) is connected to the main piston (76, 120) so that it exerts a closing force on it. [13] Vibration damper (10) for a motor vehicle comprising an outer tube (12) and an inner tube (14) arranged coaxially to it and a working piston (18) arranged axially movable within the inner tube (14), which divides the interior of the inner tube (14) into a working chamber (22) on the piston rod side and a working chamber (24) away from the piston rod, wherein the vibration damper comprises a damping valve device (54a, b) according to one of the preceding claims.

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