Damping valve device for a shock absorber of a motor vehicle

Abstract

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) which separates a main control chamber (82; 118) and a pilot control chamber (84; 122), wherein the main control chamber (82; 118) and the pilot control chamber (84; 122) are fluidically connected to one another via a flow passage (86, 136), wherein the main valve (68) has a main valve seat (90), characterized in that a spring assembly (77) is attached to the main piston (76, 120), which spring assembly rests against the main valve seat (90) in the closed position of the main valve (68), wherein one or a plurality of support disks (110) are attached between the spring assembly (77) and the main piston (76, 120), which support disks space the spring assembly (77) from the main piston (76, 120), and wherein the support disk (110) has a smaller diameter than the spring disks (106, 108) of the spring assembly (77).

Description

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

[0002] DE 10 2007 005 288 A1 discloses a vibration damper with a damping valve having a pilot-operated main valve, wherein a spring assembly is applied to the main piston for preloading. DE 10 2020 215 480 A1 discloses a vibration damper with a damping valve device, wherein the damping valve device has a main valve and a pilot valve adjustable via a solenoid coil. Particularly during dynamic operation of the vibration damper, unstable behavior of the damping valve can occur when the main valve opens and closes. In addition, acoustic problems arise during the switching process of the main valve.

[0003] The object of the present invention is therefore to provide a damping valve device for a vibration damper which does not have the above-mentioned disadvantages and can be produced cost-effectively.

[0004] This object is achieved according to the invention by a damping valve device having the features of independent device claim 1. Advantageous further developments emerge from the dependent claims.

[0005] According to a first aspect, a damping valve device for a vibration damper of a motor vehicle comprises a main valve with a main piston that separates a main control chamber and a pilot control chamber from one another. The main valve has a main valve seat, wherein a spring assembly is attached to the main piston, which spring assembly rests against the main valve seat when the main valve is in the closed position. Furthermore, one or a plurality of support disks are attached between the spring assembly and the main piston, which support disks space the spring assembly from the main piston, and wherein the support disk has a smaller diameter than the spring disks of the spring assembly.

[0006] The arrangement of a spring assembly on the main piston dampens the opening and closing of the main piston, thereby minimizing noise. The spring assembly offers the advantage that, particularly under dynamic loads, it can open the main valve even in the soft operating state, thus allowing fluid flow between the main piston and the main valve seat without the main piston moving. In addition, the spring assembly compensates for unevenness on the front side of the main piston, which, without the spring assembly, would interact with the valve seat to form a fluid-tight seal.

[0007] The damping valve device is, for example, a pressure relief valve, which can preferably be directly controlled or pilot-controlled, or a combination of a directly or indirectly controlled pressure relief valve. The main valve with the main piston is preferably designed to close and open the damping valve device, in particular the pressure relief valve. The main piston is preferably axially movable by means of the armature and / or the hydraulic pressure present in the pilot chamber.

[0008] 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 tappet 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 control chamber and the pilot working chamber and fluidically connects them to one another.

[0009] The damping valve device is arranged, for example, 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, for example 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 compensation 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 compensation chamber is partially filled with a gas.

[0010] A working piston connected to a piston rod is preferably arranged within the inner tube in such a way that it is movable within the inner tube, wherein the inner tube is preferably designed as a guide for the working piston. For example, a damping valve device according to the invention is 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 remote from the piston rod.

[0011] The damping valve device is, for example, arranged at least partially outside the outer tube of the vibration damper. With such an external arrangement of the damping valve device, a central tube is optionally arranged coaxially to and between the inner tube and the outer tube within the compensation chamber. The damping valve device is, for example, attached to the central tube. The central tube is preferably attached to the inner tube in a fluid-tight manner, with an annular space being formed between the central tube and the inner tube. The central tube preferably has a flange region for attaching the damping valve device to the central tube, which flange region preferably forms a fluid inlet and / or fluid outlet of the damping valve device. The outer tube preferably has an opening aligned with the flange region for receiving the damping valve device, such that the damping valve device is fluidly connected to the compensation chamber.For example, the vibration damper has a further damping valve device, which is also arranged outside the outer tube, for example. Preferably, the further damping valve device is fluidly connected to the inner tube, in particular to the working chamber remote from the piston rod, by means of an adapter mounted inside the inner tube. The damping valve devices are preferably of identical design.

[0012] The vibration damper preferably has a sealing assembly that fluidically seals the interior of the outer tube on the piston rod side. Opposite the sealing assembly, at the end remote from the piston rod, the interior of the outer tube is preferably fluidically sealed by a base piece. In particular, a base valve is arranged on the base piece, which is attached to the end of the inner tube remote from the piston rod.

[0013] The damping valve device comprises a preferably cylindrical damping valve housing, which has a substantially tubular tube part and a housing upper part attached to the tube part. The housing upper part has, for example, a connection area that has one or more connection contacts for an electrical power supply to the damping valve device. The connection contacts for an electrical power supply are preferably connected to a drive unit. The housing upper part has, for example, a circular-cylindrical cover section, which is adjoined by a hollow cylinder section that, for example, has a smaller diameter.

[0014] The damping valve device preferably has a drive 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 onto which the windings of the coil are wound. The coil preferably at least partially or completely encloses an armature space that extends centrally in the axial direction. An armature is preferably mounted for axial movement within the armature space. The armature is preferably mounted within the armature space so as to be slidable in the axial direction and comprises, for example, a central armature rod, which is, for example, tubular in shape and extends centrally in the axial direction through the armature space.The armature space is preferably delimited by an at least partially hollow cylindrical pole tube, which preferably serves as a guide for the armature.

[0015] The damping valve device preferably comprises a main valve and optionally a pilot valve, as well as, in particular, a valve inlet for admitting hydraulic fluid into the damping valve device and a valve outlet for discharging hydraulic fluid from the damping valve device. The pilot valve is preferably arranged downstream of the main valve. In particular, hydraulic fluid can flow through the damping valve device only in one direction.

[0016] The main valve preferably comprises a main piston arranged to be axially movable within a main working chamber. The main valve optionally comprises a housing part that at least partially delimits the main working chamber and forms an axial guide for the main piston. The main piston is preferably arranged such that it separates a main control chamber and a pilot control chamber from one another, wherein the main piston optionally has a flow passage that extends through the main piston and forms a fluidic connection between the main control chamber and the pilot control chamber. Optionally, the pilot control chamber is fluidically connected to the first or second working chamber of the vibration damper via a flow passage.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 control chamber, which is subjected to the hydraulic pressure of the pilot control chamber. It is also conceivable that the end face of the main piston facing the main control chamber is smaller than the end face of the main piston facing the pilot control chamber.

[0017] During operation of the damping valve device, in particular a pilot-operated pressure relief valve, the hydraulic fluid flows through the valve inlet into the main control chamber, whereby the pressure in the main control chamber applies an opening force to the main piston and moves it 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. At the same time, a partial flow of the hydraulic fluid flows through the flow passage in the main piston to the pilot control chamber and applies a closing force to the main piston in the direction of the main valve seat. The closing force determines the opening width of the main valve, in particular the cross-section of the main flow channel, which determines the damping force of the damping valve device.

[0018] In a pilot-operated pressure relief valve, the closing force is preferably determined by the pressure present in the pilot chamber. The pressure in the pilot chamber is adjusted, in particular, by the pilot valve, with the hydraulic fluid flowing 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 adjusted, in particular predetermined, by means of a solenoid coil.

[0019] In a directly controlled pressure relief valve, the closing force of the main piston is preferably determined by the pressure present in the pilot chamber and / or by the solenoid coil. For example, the main piston is directly connected to the armature, so that the armature applies a force to 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.

[0020] In an external damping valve device arranged outside the outer tube, the valve inlet is formed in particular in a flange region of the damping valve device, 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 in a fluid-tight manner in the closed position of the main valve. In the open position of the main valve, in which the main piston is lifted away from the main valve seat in the axial direction, 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.

[0021] A spring element is preferably attached to the side of the main piston facing away from the valve seat. This spring element is arranged in such a way that it applies a spring force to 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 washers, wherein the spring washers are preferably circular disk-shaped, in particular as a disc spring, spiral spring, wave spring, or flat spring.

[0022] The damping valve device, in particular a pilot-operated pressure relief valve, preferably comprises a connecting channel for connecting the pilot control chamber to a pilot working chamber of the pilot valve. The connecting channel is preferably formed in a housing part or in a region fixedly connected to the housing of the damping valve device and extends in particular centrally and in the axial direction. The connecting channel preferably forms the fluid inlet into the pilot valve.

[0023] The pilot valve preferably comprises a sliding tappet which is arranged so as to be axially movable within the pilot working chamber. The sliding tappet preferably bears against the armature with its end facing away from the main valve, so that the movement of the armature and the sliding tappet are mechanically coupled, at least in the pulling direction. The pilot valve is preferably movable into a closed position, in which the sliding tappet bears against a first valve seat of the pilot valve such that the connecting channel is completely closed by the sliding tappet, so that preferably no fluid flow can flow through the connecting channel into the pilot working chamber. The pilot valve is preferably movable into an open position, in which the sliding tappet is lifted from the first valve seat of the pilot valve, so that the connecting channel is opened by the sliding tappet and a fluid flow occurs between the pilot control chamber of the main valve and the pilot working chamber.

[0024] Optionally, the pilot valve comprises a preloading element arranged and configured to apply a preload force to the slide plunger. The preloading element is, for example, a spiral spring or a helical spring, which is particularly arranged and configured to apply a preload force to the slide plunger in the direction of the armature. The preloading element, which is configured as a spiral spring, flat spring, and / or helical spring, is preferably arranged coaxially to the slide plunger. Such a preloading element increases operational reliability and ensures that the slide plunger is reliably moved toward the armature and thus reaches the failsafe position in a de-energized operating state.

[0025] According to a first embodiment, the spring assembly comprises at least two or more spring washers. The spring washers, in particular the radially outward-facing region of the spring washers, is preferably elastically deformable. For example, the spring washers have different or identical stiffnesses. The spring washers are preferably arranged parallel and coaxially to one another and in particular bear against one another. The spring washers are in particular circular disk-shaped and preferably bear against the main piston with their radially inward-facing end. The spring washers are preferably fastened to the main piston with their radially inward-facing end, in particular in a fixed position. One of the spring washers preferably bears against the valve seat in the closed position of the main valve.The spring washers are used in particular to compensate for unevenness in the main valve seat and the front surface of the main piston and to improve the dynamic response of the main valve by allowing flow through the main valve even in the soft characteristic.

[0026] According to a further embodiment, at least one spring washer has a bypass opening. Preferably, the spring washer, which bears directly against the main valve seat, has a bypass opening. In the following, the spring washer, which has at least one bypass opening, is referred to as a bypass disc. The bypass opening preferably serves to provide fluid communication between the main control chamber and the valve outlet, even when the main valve is in the closed position. The bypass opening extends in particular from the radially outward-facing edge inwards. The bypass opening preferably extends radially inwards beyond the main valve seat. Preferably, the bypass opening extends across the entire axial width of the bypass disc. When the main valve is in the closed position, the bypass disc bears against the main valve seat, with hydraulic fluid flowing through the bypass opening from the main control chamber to the valve outlet.For example, the bypass disc has a plurality of bypass openings, in particular of identical design.

[0027] A support disc is mounted between the spring assembly and the main piston, spacing the spring assembly from the main piston. The support disc preferably rests against the spring assembly and main piston and serves, in particular, to axially space the spring assembly from the main piston. The support disc preferably defines the opening width of the spring assembly, which can be adjusted by selecting the appropriate thickness of the support disc.

[0028] The support disk has a smaller diameter than the spring disks of the spring assembly. For example, the support disk has a diameter that is 30% to 60% of the diameter of the spring disks. The support disk is preferably circular disk-shaped and arranged coaxially to the spring assembly. For example, the support disk is made of a non-elastically deformable material. In particular, the support disk is fixedly attached to the main piston. The support disk preferably has an axial thickness that is at least equal to or greater than the thickness of the spring assembly. The spring assembly and / or the support disk are preferably firmly attached to the main piston with their radially inner end region, preferably by means of a materially bonded, positively bonded and / or non-positively bonded connection.

[0029] According to a further embodiment, a stop is arranged on the main piston, against which the spring assembly rests. The stop preferably extends from the end face of the main piston in the axial direction, for example in the direction of the valve inlet. The spring assembly, in particular the first spring washer, preferably rests against the stop when the main valve is in a closed position. The stop preferably has an axial extent that corresponds to the thickness of the support washer. The stop is preferably arranged offset outwards in the radial direction relative to the support washer. The stop is, for example, formed integrally or in one piece with the main piston. In particular, the stop is arranged offset radially inwards relative to the valve seat and is preferably spaced apart from it. In addition to the support washer, the stop provides a spacing of the spring assembly from the main piston.

[0030] According to a further embodiment, the spring assembly is fixedly secured to the main piston. Preferably, the spring assembly is fixed in both the axial and radial directions.

[0031] According to a further embodiment, the spring assembly is clamped to the main piston, in particular, firmly clamped to the main piston. According to a further embodiment, the main piston has a recess in which the spring assembly and / or the support disc are mounted. The recess preferably extends in the radial direction and has an axial extent that corresponds to the thickness of the support disc together with the spring assembly. For example, the recess is formed by folding or bending the material of the main piston.

[0032] According to a further embodiment, a fastening ring is attached to the main piston, which is designed and arranged such that it fixes the spring assembly and in particular the support disc in the axial direction. The fastening ring is preferably arranged coaxially with the spring assembly and the support disc and preferably bears with its radially inward-facing side against the main piston, in particular the shaft region of the main piston. The fastening ring preferably bears against the spring assembly, in particular the bypass disc.

[0033] According to a further embodiment, the main piston has an axially protruding shaft portion on which the recess is formed. The recess is preferably annular and preferably extends completely circumferentially around the shaft portion of the main piston.

[0034] According to a further embodiment, the fastening ring is attached to the shaft region. Preferably, the fastening ring is fixedly attached to the shaft region.

[0035] According to a further embodiment, the end face of the main piston facing toward the main valve seat is flat. For example, the end face extends exclusively in the radial direction, orthogonal to the central axis. The end face is preferably the end face extending in the radial direction from the axially protruding shaft region of the main piston.

[0036] According to a further embodiment, the damping valve device comprises a coil and an axially movable armature which is arranged at least partially within the coil, a pilot valve with a pilot working chamber and a sliding tappet 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 control chamber and the pilot working chamber and fluidically connects them to one another.

[0037] According to a further embodiment, the damping valve device comprises a coil and an axially movable armature which is arranged at least partially within the coil, wherein the armature is connected to the main piston so that it applies a closing force thereto.

[0038] The invention also includes a vibration damper with a damping valve device as 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

[0039] The invention is explained in more detail below using several embodiments with reference to the accompanying figures. Fig. 1 shows a schematic representation of a vibration damper in a longitudinal sectional view according to an embodiment. Fig. 2 shows a schematic representation of a damping valve device in a longitudinal section according to a further embodiment. Fig. 3 shows a section of a schematic representation of the main valve seat of a damping valve device according to Fig. 2 in a longitudinal section according to further embodiments. Fig. Figure 4 shows a schematic longitudinal sectional view of a vibration damper according to an embodiment. Fig. Figure 5 shows a schematic longitudinal sectional view of a damping valve device according to a further embodiment. Fig. Figure 6 shows a section of a schematic illustration of the main valve seat of a damping valve device according to Fig. Figure 5 in a longitudinal sectional view according to further embodiments.

[0040] Fig. 1 shows a vibration damper 10, wherein the vibration damper 10 is a multi-tube vibration damper, for example a two-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. An inner tube 14, which can also be referred to as a damper tube, is arranged coaxially within the outer tube 12. Between the outer tube 12 and the inner tube 14, a compensation chamber 16 is formed, which is preferably at least partially filled with a hydraulic fluid. For example, the compensation chamber 16 is partially filled with a gas.

[0041] 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, wherein the inner tube is preferably designed as a guide for the working piston 18. The working piston 18 has, for example, a valve device (not shown). The working piston 18 divides the interior of the inner tube 14 into a first working chamber 22, which is arranged on the piston rod side, and a second working chamber 24, which is arranged remote 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.

[0042] The interior of the outer tube 12 is fluidically sealed on the piston rod side by means of a closure assembly 34. Opposite the closure assembly 34, at the end remote from the piston rod, the interior of the outer tube 12 is fluidically sealed by means of a base piece 36. A base valve 38, for example, is arranged on the base piece 36 and is attached in particular to the end of the inner tube 14 remote from the piston rod. The base valve 38 is, for example, a check valve through which flow can occur in both directions or only in one direction. The second working chamber 24 is preferably fluidically connected to the compensation chamber 16 via the base valve 38. The piston rod-side end of the inner tube 14 and the outer tube 12 is preferably attached to the closure assembly 34.

[0043] The central tube 26 is preferably attached to the inner tube 14 in a fluid-tight manner. 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 fluidically connects the first working chamber 22 to the annular space 28.

[0044] The central tube 26 has, for example, a flange region 30 for attaching a damping valve device 54a to the central tube 26. The flange region 32 forms a receptacle for the damping valve device 54a; in particular, the flange region 32 forms a fluid inlet and / or fluid outlet of the damping valve device 54a. The flange region 32 connects, for example, the annular space 28 to the damping valve device 54a. The outer tube 12 preferably has an opening aligned with the flange region 32 for receiving the damping valve device 54a, such that the damping valve device 54a is fluidly connected to the compensation chamber 16.

[0045] The vibration damper 10 comprises, for example, a further damping valve device 54b, which is fluidly connected to the inner tube 14, in particular to the working chamber 24 remote from the piston rod, by means of an adapter 40 mounted within the inner tube 14. The outer tube 12 and the central tube 26 preferably have openings aligned with the adapter for receiving the damping valve device 54a. The damping valve devices 54a, b are, for example, identically designed. For example, the damping valve devices 54a, b are designed as directly controlled or pilot-operated pressure relief valves.

[0046] The piston rod 20 has, for example, an optional pull stop which is subjected to a spring force via a spring element 42 during a movement in the pulling direction Z.

[0047] Fig. 2 shows an exemplary damping valve device 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 device 54a, b is designed, for example, as a pilot-operated pressure relief valve and comprises a preferably cylindrical damping valve housing, which has a Fig. 1, and a housing upper part 44 attached to the tubular part 45. The housing upper part 44 has, for example, a connection area 46 that has one or more connection contacts for an electrical power supply to the damping valve device 54a, b. The connection contacts for an electrical power supply are preferably connected to a drive unit. The housing upper part 44 has, for example, a circular-cylindrical cover section 56, which is adjoined by a hollow cylinder section 58 that, for example, has a smaller diameter.

[0048] The damping valve device 54a, b has, for example, a drive region 48 and a valve region 50. The drive region 48 is arranged, for example, in the upper region of the damping valve device 54a, b facing the upper housing part 44 and preferably substantially above the valve region 50. The drive region 48 preferably comprises a drive 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 tubular part 45 and concentrically therewith. For example, the coil 52 is arranged within the hollow cylindrical section 58 of the upper housing part 44 and in particular rests against the inner wall of the upper housing part 44.The upper housing part 44 is made, for example, from a plastic, in particular a non-magnetic or only very slightly magnetic material, preferably a magnetic insulator or a material with a high magnetic resistance. The coil 52 comprises, for example, a coil carrier on which the windings of the coil are wound. The coil 52 at least partially or completely encloses an armature chamber 60 that extends centrally in the axial direction. An armature 62 is mounted for axial movement 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, such that the armature 62 is preferably mounted so as to be slidable in the axial direction. For 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 delimited by an at least partially hollow-cylindrical pole tube 64. The pole tube 64 preferably has a bottom and is open, in particular, in the direction of the valve region 50. The pole tube 64 is preferably formed from a magnetizable or magnetic material and, for example, has a magnetic separation (not shown).

[0049] The coil 52 is preferably designed and arranged such that, when energized, it creates a magnetic field having magnetic field lines that preferably extend substantially in the axial direction within the armature chamber 60. The armature 62 is preferably formed from a magnetizable or magnetic material and is movable in the axial direction according to the polarity of the magnetic field created by the coil 52.

[0050] The hollow cylindrical region of the pole tube 64 is adjoined in the axial direction and coaxially thereto by a pole tube element, which together form the pole tube 64, wherein the pole tube 64 is in particular designed in several parts, in one piece or in one piece. The pole tube 64 has an upper tubular region with in particular a constant inner diameter, which is preferably designed as a hollow cylinder and extends from the upper housing part 44 in the axial direction up to beyond the armature 62. The upper hollow cylindrical region is adjoined in the axial direction by a lower region with an enlarged diameter, wherein the outer surface of the pole tube 64 preferably extends up to the Fig. 1, extends and at least partially abuts the tube part 45 and is sealed fluid-tight to the tube part 45 via a sealing element 66. The pole tube 64 at least partially encloses a valve region 50, which will be explained in more detail in one of the following sections.

[0051] The valve region 50 comprises, for 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 device 54a, b and a valve outlet 74 for discharging hydraulic fluid from the damping valve device 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 comprises a main piston 76, which is arranged to be axially movable within a main working chamber 78. The main valve 68 also comprises, for 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 therewith.The main piston 76 preferably divides the main working chamber 78 into a main control chamber 82 and a pilot control 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 control chamber 84.

[0052] The valve inlet 72 is formed in particular in a flange region 88 of the damping valve device 54a, b, wherein the flange region 88 is preferably connectable to an outer tube 12, inner tube 14, and / or center tube 26 of the vibration damper 10. A main valve seat 90 is formed on the flange region 88. A spring assembly 77 is attached to the main piston 76, which spring assembly rests against the main valve seat 90 in the closed position of the main valve 68.

[0053] 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 and the spring assembly 77 are 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.

[0054] The main piston 76 has a particularly central recess on its surface facing toward the drive region 48, so that the main piston 76 has a hollow cylindrical region. The recess of the main piston 76, in particular the interior of the hollow cylindrical region, preferably at least partially delimits the pilot chamber 84. On the side of the main piston 76 facing away from the main valve seat 90, a spring element 94 is attached, which is arranged such that it applies a spring force to 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 disk packs, in particular spring disks, wherein the spring disk packs are preferably circular disk-shaped, in particular as a disc spring.The spring element 94 preferably extends over the entire diameter of the pilot chamber 84, in particular to the inner wall of the housing part 80.

[0055] 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 arranged, for example, in the pilot control chamber 84 and is supported on the housing part 80 or is fixedly connected thereto. A connecting channel 98 is preferably formed in the central block 96 for connecting the pilot control chamber 84 to a pilot working chamber 100 of the pilot valve 70. The connecting channel 98 preferably extends centrally and in the axial direction through the central block 96. The connecting channel 98 preferably forms the fluid inlet into the pilot valve 70.

[0056] The pilot valve 70 comprises, for example, a sliding tappet 102 which is arranged to be axially movable within the pilot working chamber 100. The sliding tappet 102 preferably bears against the armature 62 with its end facing away from the main valve 68, so that the movement of the armature 62 and the sliding tappet 102 are coupled, at least when the armature 62 moves in the direction of the sliding tappet 102. In a closed position of the pilot valve 70, the sliding tappet 102 preferably bears against the central block 96 such that the connecting channel 98 is completely closed by the sliding tappet 102. In an open position of the pilot valve 70, the sliding tappet 102 is lifted off the central block 96, so that the connecting channel 98 is exposed by the sliding tappet 102 and a fluid flow occurs between the pilot control 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 arranged in a fixed position and, for example, rests against the housing part 80 or is firmly connected thereto. The pilot working chamber 100 is formed within the pilot housing part 104, wherein the inner wall of the pilot housing part forms a preferably fluid-tight contact surface with the sliding tappet 102. The pilot housing part 104 preferably forms an axial guide for the sliding tappet 102. The sliding tappet 102 has, for example, a T-shaped longitudinal section, wherein the sliding tappet 102 has a first region facing the connecting channel 98 with a cross-section that is larger than the cross-section of the connecting channel 98 and a second region 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.

[0057] In the closed position, the sliding tappet 102 preferably abuts a first valve seat formed in the central block 96. The sliding tappet 102 of the pilot valve 70 preferably has at least one or a plurality of passage bores 112 that extend axially through the sliding tappet 102 and form a flow channel for hydraulic fluid through the sliding tappet 102.

[0058] During operation of the damping valve device 54a, b, the hydraulic fluid flows through the valve inlet 72 into the main control chamber 82, wherein the pressure in the main control chamber 82 applies an opening force to the main piston 76 and moves it axially upward. 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. At the same time, a partial flow of the hydraulic fluid flows through the flow passage 86 in the main piston 76 to the pilot control chamber 84, applying a closing force to the main piston in the direction of the main valve seat 90. The closing force determines the opening width of the main valve 68, in particular the cross-section of the main flow channel 92, which determines the damping force of the damping valve device 54a, b.The pressure in the pilot control chamber 84 is adjusted by the pilot valve 70, with the hydraulic fluid flowing from the pilot control chamber 84 through the connecting channel 98 into the pilot working chamber 100, which is opened by the sliding tappet 102. The opening width of the connecting channel 98 depends on the axial position of the sliding tappet 102, which is adjusted, in particular predetermined, by means of a solenoid coil 54. In the closed position of the pilot valve 70, the sliding tappet 102 preferably completely closes the connecting channel 98, so that the hydraulic pressure in the pilot control chamber 84 rises to a maximum value and the main valve 68 is closed by pressing the main piston 76 onto 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 tappet 102, so that a hydraulic flow flows through the passage bores 112 in the sliding tappet 102 and flows to the valve outlet 74 via a flow channel arranged downstream of the passage bores 112.

[0059] Fig. 3 shows a section of a damping valve device 54a, b according to Fig. 2, wherein the main valve seat 90 is shown. The main valve seat 90 is preferably a component mounted stationary within the damping valve device 54a, b. Preferably, the main valve seat 90 is attached to the flange region 88 or formed integrally therewith. Fig. 3 shows the closed position of the main valve 68, with the spring assembly 77 resting against the main valve seat 90. The spring assembly 77 comprises, for example, two spring washers, a first spring slide 106 and a second spring washer 108. For example, the spring washers 106, 108 are circular disk-shaped and are mounted on the main piston 76, in particular coaxially therewith.

[0060] The second spring washer 108 is preferably arranged such that it rests against the main valve seat 90 in the closed position of the main valve 68. The spring washers 106 and 108 are preferably mounted parallel to one another and bear directly against one another. The spring washers 106 and 108 are preferably formed from an elastically deformable material. In particular, the second, lower spring washer 108 has a bypass opening which Fig. 3 is not shown. The bypass opening preferably extends radially from the outside to the inside, in particular from the radially outward-facing edge to the inside. The bypass opening preferably extends radially inward beyond the main valve seat 90. The bypass opening preferably extends across the entire axial width of the second spring washer 108.

[0061] In the closed position of the main valve 68, the second spring washer 108, also referred to as the bypass washer 108, rests against the valve seat 90, with hydraulic fluid flowing through the bypass opening from the main control chamber 82 to the valve outlet 74. For example, the second spring washer 108 has a plurality of bypass openings, in particular identically designed ones. The first, upper spring washer 106 preferably has no bypass openings.

[0062] A support disk 110 is preferably mounted between the spring assembly 77 and the main piston 76. The support disk 110 preferably abuts the first spring disk 106 and the main piston 76. For example, the support disk 110 has a smaller diameter than the spring disks 106, 108 of the spring assembly 77. The support disk 110 is arranged, in particular, coaxially to the spring assembly 77 and is preferably fixedly attached to the main piston 76. The support disk 110 preferably has a diameter that corresponds to 30% to 60% of the diameter of the spring assembly 77 and / or the main piston 76. The support disc 110 preferably has an axial thickness that is at least equal to or greater than the thickness of the spring assembly 77. The support disc 110 preferably spaces the spring assembly 77 from the main piston 76, in particular the end face of the main piston 76.

[0063] The spring assembly 77 and in particular the support disk 110 are preferably fixedly attached to the main piston 76 with their radially inner end region, preferably by means of a materially bonded, positively locking, and / or non-positively locking connection. In particular, the spring assembly 77 and the support disk 110 are clamped to the main piston 76. The main piston 76 preferably has a shaft region 114 that forms a central, axial projection relative to the end face of the main piston 76. In the shaft region 114 there is a radial recess 113 in which the radial end regions of the spring assembly 77 and / or the support disk 110 are attached, in particular fastened, preferably firmly clamped. The spring assembly 77 and the support disk 110 are preferably fixed within the recess 113 in the main piston 76 in the radial and axial directions.

[0064] For example, a stop 115 is formed on the main piston 76, which extends in the axial direction from the end face of the main piston 76. The spring assembly 77, in particular the first spring washer 106, bears against the stop 115. The stop preferably has an axial extension that corresponds to the thickness of the support washer 110. The stop 115 is preferably arranged offset radially outwardly from the support washer 110. In particular, the stop 115 is arranged offset radially inwardly from the valve seat 90 and preferably spaced apart from it.

[0065] Fig. 4 shows a vibration damper 10 which essentially corresponds to the Fig. 1, wherein a damping valve device 54c is arranged on the working piston 18. In contrast to the Fig. 1, the vibration damper 10 of the Fig. 4 no center tube and no external damping valve devices 54a, b.

[0066] Fig. 5 shows a detailed view of the damping valve device 54c. The damping valve device 54c also includes a drive portion 48 with a coil 52 and an armature 62 axially movable therein, as described with reference to Fig. 2. The damping valve device 54c also has a valve region 50 with a main valve 68 and a pilot valve 70. For example, the damping valve device 54c has two main valves 68a, b, each arranged on one side of the working piston 18, so that one main valve 68a or b is active in the rebound stage or the compression stage of the vibration damper 10.

[0067] The working piston 18 has a fluid passage 116 that opens into a main control chamber 118 of the main valve 68. The main piston 120 fluidically separates the main control chamber 118 from the pilot control chamber 122. The main valve seat 124, against which the main piston 120 rests when the respective main valve 68 is in a closed position, is formed on the working piston 18 or a component rigidly connected thereto. The closing force acting on the main piston 120 in the direction of the main valve seat 124 is determined by the hydraulic pressure present in the pilot control chamber 122. For example, the pilot control chambers 122 of the two main valves 68a, b are connected to one another via a flow channel, so that the same pressure is preferably present in the pilot control chambers 122 of the main valves 68a, b. The pressure present in the two pilot control chambers 122 is preferably adjustable via the pilot valve 70.The pilot valve 70 has a sliding tappet 126 which is mounted so as to be axially movable and, in a closed position of the pilot valve 70, rests on a first valve seat of the pilot valve 70. The pilot control chambers 122 are hydraulically connected, for example, via a connecting channel 130 to the pilot working chamber 132. The flow cross-section of the connecting channel 130 can be closed at least partially or completely by means of the sliding tappet 126, wherein the sliding tappet 126 rests against the first valve seat 128 of the pilot valve 70. The movement of the sliding tappet 126 is preferably coupled to the armature 62 at least in one direction of movement and, as described with reference to FIG. Fig. 1 to 3, is moved axially via the coil 52.

[0068] The main piston 120 is preferably arranged to be movable relative to a fixed flange region 134. A flow passage 136 is formed in the flange region 134, which connects the pilot chamber 122 to the respective working chamber 22, 24 of the vibration damper 10. The flow passages 136 are preferably each connected to a check valve, so that hydraulic flow is permitted exclusively from the respective working chamber 22, 24 into the respective pilot chamber 122 and not vice versa.

[0069] When the working piston 18 moves in the pressure direction D, hydraulic fluid flows, for example, from the working chamber 24 remote from the piston rod via the flow passage 136 of the main valve 68b into one of the pilot control chambers 122, so that the same pressure is present in the pilot control chambers 122 due to the hydraulic connection. The position of the sliding tappet 126 relative to the first valve seat 128 determines the outflow of the hydraulic fluid via the pilot valve 70 and thus the resulting pressure in the pilot control chamber 122. The pilot working chamber 132 of the embodiment of the Fig. 5 is preferably fluidically connected to an outflow channel 148 through which the hydraulic fluid can flow from the pilot working chamber 132 into the first or second working chamber 22, 24.

[0070] Fig. 6 shows a detailed view of the main valve seat 124, wherein a spring assembly 77 is attached to the main piston 120, which is essentially the same as the spring assembly 77 of the Fig. 3 and wherein like elements are provided with like reference numerals. The main piston 120 of the Fig. 6 also has a shaft portion 114. A fastening ring 150 is attached to the shaft portion 114, which is arranged coaxially with the spring assembly 77 and the support disk 110 and rests with its radially inward-facing side against the shaft portion 114 of the main piston 120. The fastening ring 150 preferably rests against the spring assembly 77, in particular the second spring disk 108. The fastening ring 150 is preferably arranged and designed such that it fixes the spring assembly 77 and the support ring 110 in the axial direction. List of reference symbols 10 vibration dampers 12 Outer tube 14 inner tube 16 Compensation room 18 working pistons 20 piston rod 22 first / piston rod side working chamber 24 second / piston rod remote working chamber 26 Middle pipe 28 annular space 30 passage opening 32 flange area 34 closure package 36 floor pieces 38 bottom valve 40 adapters 42 spring element 44 Upper housing part 45 Pipe part 46 Connection area 48 drive range 50 valve range 52 coil 54a, b, c Damping valve device 56 cover section 58 Hollow cylinder section 60 anchor room 62 anchors 64 Pole tube 65 anchor rod 66 Sealing element 68 Main valve 70 pilot valve 72 valve inlet 74 Valve outlet 76 / 120 main piston 77 spring package 78 Main workroom 80 Housing part 82 / 118 Main control room 84 / 122 Pre-control room 86 / 136 flow passage 88 / 134 flange area 90 / 124 main valve seat 92 Main flow channel 94 spring element 96 Central Block 98 / 130 connecting channel 100 / 132 Pilot workroom 102 / 126 sliding tappet 104 Pilot housing part 106 first spring washer 108 second spring washer / bypass washer 110 support disc 112 through hole 113 Recess 114 Main piston skirt area 76 115 stop 116 Fluid passage in the working piston 18 118 Main control room 128 first valve seat 136 Flow passage 138 Preloading element 148 outflow channel 150 mounting ring

Claims

[1] 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) which separates a main control chamber (82; 118) and a pilot control chamber (84; 122), wherein the main control chamber (82; 118) and the pilot control chamber (84; 122) are fluidically connected to one another via a flow passage (86, 136), wherein the main valve (68) has a main valve seat (90), characterized by , that a spring assembly (77) is attached to the main piston (76, 120), which spring assembly rests against the main valve seat (90) in the closed position of the main valve (68), wherein one or a plurality of support disks (110) are attached between the spring assembly (77) and the main piston (76, 120), which support disks space the spring assembly (77) from the main piston (76, 120), and wherein the support disk (110) has a smaller diameter than the spring disks (106, 108) of the spring assembly (77). [2] Damping valve device (54a, b, c) according to claim 1, wherein the spring assembly (77) comprises at least two or more spring washers (106, 108). [3] Damping valve device (54a, b, c) according to claim 2, wherein at least one spring washer has a bypass opening. [4] Damping valve device (54c) according to one of the preceding claims, wherein a stop (115) is arranged on the main piston (76, 120), against which the spring assembly (77) rests. [5] Damping valve device (54a, b, c) according to one of the preceding claims, wherein the spring assembly (77) is fixed in position to the main piston (76, 120). [6] Damping valve device (54a, b, c) according to one of the preceding claims, wherein the spring assembly (77) is clamped to the main piston (76, 120). [7] Damping valve device (54a, b) according to one of the preceding claims, wherein the main piston (76, 120) has a recess (113) in which the spring assembly (77) and / or the support disc (110) is mounted. [8] Damping valve device (54c) according to one of the preceding claims, wherein a fastening ring (150) is attached to the main piston (120), which is designed and arranged such that it fixes the spring assembly (77) in the axial direction. [9] Damping valve device (54a, b) according to claim 7, wherein the main piston (76; 120) has an axially projecting shaft portion (114) on which the recess (113) is formed. [10] Damping valve device (54c) according to claim 8 or 9, wherein the main piston (76; 120) has an axially projecting shaft portion (114) to which the mounting ring (150) is attached. [11] Damping valve device (54c) according to one of the preceding claims, wherein the end face of the main piston (76, 120) pointing in the direction of the main valve seat (90) is flat. [12] Damping valve device (54a, b, c) according to one of the preceding claims, comprising a coil (52), an axially movable armature (62) arranged at least partially within 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 pilot control chamber (84; 122) and the pilot working chamber (100; 132) and fluidically connects them to one another. [13] Damping valve device (54a, b, c) according to one of claims 1 to 11 comprising a coil (52), an axially movable armature (62) arranged at least partially within the coil (52), the armature (62) being connected to the main piston (76, 120) so as to apply a closing force thereto. [14] Vibration damper (10) for a motor vehicle comprising an outer tube (12) and an inner tube (14) arranged coaxially thereto 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) remote from the piston rod, wherein the vibration damper comprises a damping valve device (54a, b, c) according to one of the preceding claims.

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