Damping valve device for shock absorber of motor vehicle

Abstract

The invention relates to a damping valve device for a shock absorber of a motor vehicle and to a shock absorber. A damping valve device for a shock absorber of a motor vehicle comprises: a winding; an axially movable magnetic core arranged at least partially inside the winding; a main valve having a main piston which fluidically separates the main control chamber from the pre-control chamber; the pilot valve is provided with a pilot working chamber and a sliding block arranged in the pilot working chamber, and the sliding block can move axially by means of a magnetic core; and a connecting channel which is arranged between the main control chamber and the pilot working chamber and fluidically connects the main control chamber and the pilot working chamber to each other, the pilot valve having a first valve seat on which the slide rests in the closed position of the pilot valve such that the connecting channel is closed in a fluid-tight manner by means of the slide. The pilot valve has a spring element, the pilot valve has a second valve seat, and the spring element interacts with the second valve seat in a fail-safe position of the pilot valve.

Description

Technical Field

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

[0002] DE 10 2020 215 480 A1 discloses a shock absorber having a damping valve arrangement, wherein the damping valve arrangement has a main valve and a pilot valve adjustable by a magnetic winding. When the magnetic winding is de-energized, the pilot valve moves into a fail-safe position, wherein the hydraulic pressure usually in the pilot control chamber of the main valve is released via lateral flow channels, which allow hydraulic fluid to flow only in the fail-safe position. The production of such flow channels is complex and therefore very costly. Summary of the invention

[0003] It is therefore an object of the present invention to provide a damping valve arrangement for a shock absorber which allows the hydraulic pressure at the main valve to be adjusted even in the fail-safe position and which can be produced cost-effectively.

[0004] This object is achieved according to the invention by a damping valve arrangement having the features of the independent device claim 1. Advantageous developments are revealed in the dependent claims.

[0005] According to a first aspect, a damping valve device for a shock absorber of a motor vehicle comprises: a winding; an axially movable magnetic core, which is at least partially arranged inside the winding; a main valve with a main piston, which fluidically separates a main control chamber and a pilot control chamber; a pilot valve, which has a pilot working chamber and a slider arranged in the pilot working chamber, which slider can be axially moved by means of the magnetic core; and a connecting channel, which is arranged between the main control chamber and the pilot working chamber and fluidically connects the two to each other, wherein the pilot valve has a first valve seat, on which the slider rests in the closed position of the pilot valve, so that the connecting channel is closed by the slider in a fluid-tight manner. The pilot valve has a spring element, wherein the pilot valve has a second valve seat, with which the spring element cooperates in a fail-safe position of the pilot valve, in which the winding is de-energized. Preferably, the spring element is arranged in such a way that it cooperates with the second valve seat only in the fail-safe position of the pilot valve. Preferably, the spring element does not interact with the second valve seat when the winding is energized. When the pilot valve is in the fail-safe position, the spring element in particular at least partially or completely rests on the second valve seat. Preferably, the spring element interacts with the second valve seat in such a way that the spring element determines the flow of hydraulic fluid between the pilot working chamber and the valve outlet for discharging the hydraulic fluid from the damping valve arrangement.

[0006] The arrangement of the second valve seat in the pilot valve provides the advantage that even in the fail-safe position of the pilot valve, a controlled outflow of hydraulic fluid from the pilot working chamber is possible and thus the pressure in the pilot control chamber of the main valve can be adjusted even when the coil is de-energized. In addition, complex and expensive lateral outflow channels can be omitted.

[0007] The damping valve arrangement is arranged, for example, in a shock absorber for a motor vehicle. The shock absorber is, for example, a multi-tube shock absorber, such as a twin-tube shock absorber. The shock absorber comprises, for example, an outer tube, which forms the outer surface of the shock absorber, in particular the housing. Inside the outer tube, an inner tube is arranged coaxially with the outer tube, which inner tube is also referred to as a damping tube. A compensation space 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 space is partially filled with a gas.

[0008] Inside the inner tube, a working piston connected to the piston rod is preferably arranged so that the working piston can move in the inner tube, wherein the inner tube is preferably configured as a guide for the working piston. For example, a damping valve device according to the present invention is arranged on the working piston. The working piston divides the inner chamber of the inner tube into a first working chamber on the piston rod side and a second working chamber away from the piston rod.

[0009] The damping valve device is, for example, at least partially arranged outside the outer tube of the shock absorber. When the damping valve device is arranged outside in this way, an intermediate tube can be optionally arranged inside the compensation space, which is coaxial with the inner tube and the outer tube and is arranged between the two. The damping valve device is, for example, mounted on the intermediate tube. The intermediate tube is preferably mounted on the inner tube in a fluid-tight manner, wherein an annular space is constructed between the intermediate tube and the inner tube. The intermediate tube preferably has a flange area for mounting the damping valve device on the intermediate tube, and the flange area is preferably constructed as a fluid inlet and / or fluid outlet of the damping valve device. The outer tube preferably has an opening aligned with the flange area, which is used to accommodate the damping valve device so that the damping valve device is connected to the compensation space in terms of fluid technology. For example, the shock absorber has another damping valve device, which is, for example, also arranged outside the outer tube. Preferably, the other damping valve device is connected to the inner tube, especially to the working chamber away from the piston rod, in terms of fluid technology by means of an adapter installed inside the inner tube. These damping valve devices are preferably constructed identically.

[0010] The shock absorber preferably has a closure assembly which seals the interior of the outer tube fluidically on the piston rod side. Opposite the closure assembly, the interior of the outer tube is fluidically sealed at the end remote from the piston rod, preferably by means of a bottom part. In particular, a bottom valve is arranged on the bottom part, which is mounted at the end of the inner tube remote from the piston rod.

[0011] The damping valve device comprises a preferably cylindrical damping valve housing having a substantially tubular tube part and a housing upper part mounted on the tube part. The housing upper part has, for example, a connection area with one or more connection contacts for supplying current to the damping valve device. Preferably, the connection contacts for supplying current are connected to the drive unit. The housing upper part has, for example, a cylindrical cover section, to which a hollow cylindrical section is connected, which hollow cylindrical section has, for example, a smaller diameter.

[0012] The damping valve device preferably has a drive device configured as an electromagnet, in particular a winding having a plurality of coils made of an electrically conductive wire. The winding is preferably arranged inside the housing of the damping valve device and comprises, for example, a winding frame on which the coils of the winding are wound. Preferably, the winding at least partially or completely surrounds a magnetic core chamber, which extends centrally in the axial direction. A magnetic core is preferably supported axially movably inside the magnetic core chamber. The magnetic core is preferably slidably mounted inside the magnetic core chamber in the axial direction and, for example, comprises a central magnetic core rod, which is, for example, tubular and extends centrally in the axial direction through the magnetic core chamber. The magnetic core chamber is preferably delimited by an at least partially hollow cylindrical pole tube, which preferably serves as a guide for the magnetic core.

[0013] The damping valve device preferably comprises a main valve and a pilot valve, and in particular a valve inlet for introducing 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, the damping valve device allows hydraulic fluid to pass only in one direction.

[0014] The main valve preferably comprises a main piston, which is arranged axially displaceably within the main working chamber. The main valve optionally comprises a housing component, which at least partially delimits the main working chamber and forms an axial guide for the main piston. The main piston is preferably arranged in such a way that the main piston separates the main control chamber and the pilot control chamber from one another, wherein the main piston optionally has a flow through-hole, which extends through the main piston and forms a fluid 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 shock absorber via the flow through-hole.

[0015] For an external damping valve device arranged outside the outer tube, the valve inlet is particularly configured in the flange area of ​​the damping valve device, wherein the flange area is preferably connected to the outer tube, the inner tube, and / or the intermediate tube of the shock absorber. The main valve preferably has a main valve seat, which is configured on the flange area, for example, and the main piston rests on the main valve seat in a fluid-tight manner in the closed position of the main valve. In the open position of the main valve, the main piston is lifted from the main valve seat in the axial direction, in which position a main flow channel is preferably configured between the main piston and the valve seat. The main flow channel preferably forms a fluid connection between the valve outlet and the valve inlet, in particular with the main control chamber.

[0016] On the side of the main piston away from the valve seat, a spring element is preferably mounted, which is arranged so that it loads the main piston with a spring force in the direction of the main valve seat. The spring element is, for example, a preloaded spring having one or at least two spring washer groups, wherein the spring washer group is preferably configured in a disk shape, in particular as a disk spring.

[0017] The damping valve device preferably comprises a connecting channel for connecting the pilot control chamber to the pilot working chamber of the pilot valve. The connecting channel is preferably configured in a housing component or in an area that is fixedly connected to the housing of the damping valve device and extends in particular centrally and in the axial direction. Preferably, the connecting channel forms a fluid inlet into the pilot valve.

[0018] The pilot valve preferably comprises a slide which is axially movable within the pilot working chamber. The slide preferably bears against the magnetic core with its end facing away from the main valve, so that the movement of the magnetic core and the slide is mechanically coupled at least in the pulling direction. The pilot valve is preferably movable into a closed position, in which the slide bears against the first valve seat of the pilot valve so that the connecting channel is completely closed by the slide, 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 slide is lifted from the first valve seat of the pilot valve, so that the connecting channel is released by the slide and a fluid flow is formed between the pilot control chamber of the main valve and the pilot working chamber.

[0019] The pilot valve preferably has a spring element, which is arranged in a fixed position in the pilot valve of the damping valve device and, for example, comprises a spring washer or a plurality of spring washers. The spring washer is preferably configured in a disc shape and is, in particular, arranged coaxially with the slide and / or the magnetic core. The disc-shaped spring washer is preferably connected to the pilot housing part of the pilot valve at a radially outer region, in particular fixed thereto. The radially inwardly directed region of the spring washer is preferably elastically deformable.

[0020] According to a first embodiment, the second valve seat of the pilot valve is formed on the slide. Preferably, the slide has a second valve seat on its side facing the magnetic core, against which the spring element, in particular the spring washer, can rest. The valve seat is, for example, formed as a flat surface, so that the spring washer preferably rests flatly on the valve seat. The formation of the valve seat on the slide is a space-saving solution, wherein an additional component for producing the second valve seat is omitted inside the pilot valve.

[0021] According to another embodiment, the pilot valve has a fluid channel for fluidically connecting the pilot working chamber to the valve outlet, wherein the spring element is designed and arranged on the fluid channel in such a way that the spring element releases the fluid flow in the fail-safe position of the pilot valve and blocks the fluid flow in a position of the pilot valve that differs from the fail-safe position. The pilot working chamber is preferably fluidically connected to an outflow channel through which the hydraulic fluid can flow from the pilot working chamber into the valve outlet, in particular into the first or second working chamber.

[0022] The pilot working chamber is separated from the outflow channel in fluid technology, in particular by means of a closing gasket, wherein the closing gasket preferably has a cutout through which the slider extends. For example, the first valve seat of the pilot valve is constructed on the closing gasket and acts together with the slider. For example, the second valve seat of the pilot valve is also constructed on the closing gasket, wherein the spring element is mounted on the closing gasket. In particular, the closing gasket has at least one or more fluid channels, which are used to connect the pilot working chamber to the outflow channel. The spring element is arranged and constructed, for example, so that when the hydraulic pressure inside the pilot working chamber is lower than a specific value, the spring element at least partially or completely closes the fluid channel. If the hydraulic pressure in the pilot working chamber exceeds a specific pressure, in particular the opening pressure of the spring element constructed as a spring gasket, the spring element is lifted from the second valve seat and at least partially releases the fluid channel. The spring element is preferably constructed so that the opening pressure is less than the hydraulic pressure set in the pilot working chamber in the currentless operation. Preferably, the opening pressure is greater than the hydraulic pressure prevailing within the pilot working chamber during normal operation, so that the spring element is designed in such a way that it opens only during fail-safe operation.

[0023] According to another embodiment, the spring element has at least one spring washer. Preferably, the spring element has a plurality of spring washers, which have, for example, different stiffnesses. The spring washers are preferably arranged parallel to each other and coaxially, and in particular abut against each other.

[0024] According to another embodiment, the spring element, in particular at least one or all spring washers, has a central circular cutout, which is arranged coaxially to the slide and / or the magnet core in such a way that the magnet core can be axially moved through the cutout. The spring element is preferably arranged in a fixed position, wherein the magnet core and the slide are mounted so as to be movable relative to the spring element. This ensures that the spring element rests on the valve seat only in a specific axial position of the slide and has no or only a very small influence on the flow of the hydraulic fluid in the remaining positions of the slide, preferably in the remaining positions reached during normal operation of the damping valve arrangement.

[0025] According to another embodiment, the slide of the pilot valve has at least one or more through-holes, which extend through the slide in the axial direction and form a flow channel for the hydraulic fluid through the slide, and wherein the spring element extends radially beyond the through-holes, so that the spring element at least partially or completely covers, in particular closes, the through-holes in the fail-safe position of the pilot valve. Preferably, the slide is designed such that it closes the entire diameter of the pilot working chamber in a fluid-tight manner, so that the hydraulic fluid can flow, in particular, only through the through-holes. This arrangement can damp the fluid flow in the fail-safe position of the pilot valve.

[0026] According to another embodiment, the slide is arranged radially offset relative to the central cutout. Preferably, the central longitudinal axes of the slide and the central cutout are arranged parallel to each other and spaced apart from each other. This enables a space-saving arrangement of the slide inside the pilot working chamber.

[0027] According to another embodiment, the second valve seat of the pilot valve has a control edge, the spring element cooperates with the control edge, and wherein the control edge is configured as an axial projection. The control edge is preferably a region of the valve seat, on which the spring element, in particular the spring washer, can rest. The control edge configured as an axial projection extends, for example, in the axial direction relative to the magnetic core, and is optionally configured as a circular ring, for example, as a partial circle or a full circle. The axial height of the control edge is preferably configured so that the spring element rests on the control edge in a relaxed or prestressed manner in the fail-safe position of the pilot valve. The slider, for example, has a diameter that is smaller than the diameter of the pilot working chamber, wherein the control edge is arranged on a region of the slider that points radially outward.

[0028] According to another embodiment, the control edge is arranged radially inwardly relative to the through-opening in the slide. This enables an optimal interaction of the spring element with the control edge of the second valve seat.

[0029] According to another embodiment, the pilot valve has an axial stop for the slide to abut against in the fail-safe position of the pilot valve. This enables an optimal positioning of the slide in the fail-safe position of the pilot valve.

[0030] According to another embodiment, the axial stop is formed by a magnetic core and / or a spring element. According to another embodiment, the spring element is arranged such that in the fail-safe position of the pilot valve, the spring element bears against the second valve seat in a position prestressed in the direction of the second valve seat. For example, the axial stop is formed in this case by a magnetic core which is spaced apart from the spring element in the axial direction such that the spring element is prestressed by the slide in the fail-safe position.

[0031] According to another embodiment, the pilot valve comprises a preload element, which is arranged and constructed in such a way that it applies a preload force to the slide. The preload element is, for example, a helical spring or a disc spring, which is particularly arranged and constructed in such a way that the preload element applies a preload force to the slide in the direction of the magnetic core. Preferably, the preload element, which is designed as a helical spring or a disc spring, is arranged coaxially with the slide. Such a preload element increases operational safety and ensures that the slide moves reliably toward the magnetic core and thus reaches a fail-safe position in a currentless operating state.

[0032] According to another embodiment, a bypass channel is formed in the slide, in particular in the control edge or in the spring element, which bypass channel connects the pilot working chamber to the valve outlet for discharging hydraulic fluid from the damping valve device. As a result, even in the closed position in which the spring element bears against the second valve seat of the pilot valve, an additional flow of hydraulic fluid to the valve outlet is achieved.

[0033] The invention also includes a shock absorber having an aforementioned damping valve arrangement, wherein the damping valve arrangement is arranged, for example, on the working piston and / or at least partially outside the outer tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention is explained in more detail below with reference to a number of exemplary embodiments and with reference to the accompanying drawings.

[0035] Figure 1 A schematic diagram of a vibration absorber according to an exemplary embodiment is shown in a longitudinal section.

[0036] Figure 2 A schematic illustration of a damping valve arrangement according to a further exemplary embodiment is shown in a longitudinal section.

[0037] Figure 3a , 3b and Figure 3c Schematic diagrams of pilot valves of damping valve arrangements according to other exemplary embodiments are shown in longitudinal sectional views, respectively.

[0038] Figure 4 A schematic diagram of a vibration absorber according to an exemplary embodiment is shown in a longitudinal section.

[0039] Figure 5A schematic illustration of a damping valve arrangement according to a further exemplary embodiment is shown in a longitudinal section.

[0040] Figure 6a and Figure 6b Schematic diagrams of a pilot valve of a damping valve arrangement according to another exemplary embodiment are shown in longitudinal sections, respectively.

[0041] Figure 7 A schematic diagram of a detail of a damping valve arrangement according to a further exemplary embodiment is shown in a longitudinal section. DETAILED DESCRIPTION

[0042] Figure 1 A shock absorber 10 is shown, wherein the shock absorber 10 is a multi-tube shock absorber, for example a twin-tube shock absorber. The shock absorber 10 has an outer tube 12, which forms the outer surface of the shock absorber 10, in particular the housing. An inner tube 14 is arranged coaxially with the outer tube inside the outer tube 12, which inner tube can also be referred to as a damping tube. A compensation space 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 space 16 is partially filled with a gas.

[0043] The working piston 18 connected to the piston rod 20 is arranged inside the inner tube 14 so that the working piston can move inside the inner tube 14, wherein the inner tube is preferably configured 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 inner cavity of the inner tube 14 into a first working chamber 22 arranged on the piston rod side and a second working chamber 24 arranged away from the piston rod. Inside the compensation space 16, the intermediate tube 26 is arranged coaxially between the inner tube 14 and the outer tube 12.

[0044] The inner chamber 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, the inner chamber of the outer tube 12 is fluidically sealed on the end remote from the piston rod by means of a bottom part 36. A bottom valve 38 is arranged, for example, on the bottom part 36, which is particularly mounted on the end of the inner tube 14 remote from the piston rod. The bottom valve 38 is, for example, a non-return valve which can allow fluid to pass through in both directions or only in one direction. The second working chamber 24 is preferably fluidically connected to the compensation space 16 via the bottom valve 38. The ends of the inner tube 14 and the outer tube 12 on the piston rod side are preferably fixed to the closure assembly 34.

[0045] The central tube 26 is preferably mounted in a fluid-tight manner on the inner tube 14. An annular space 28 is formed between the central tube and the inner tube 14. At least one through-hole 30 is formed in the inner tube 14, which connects the first working chamber 22 to the annular space 28 in a fluid-tight manner.

[0046] The intermediate tube 26 has, by way of example, a flange region 32 for mounting the damping valve device 54a on the intermediate tube 26. The flange region 32 forms a receptacle for the damping valve device 54a, in particular forming a fluid inlet and / or a fluid outlet of the damping valve device 54a. The flange region 32 connects the annular space 28 to the damping valve device 54a, for example. The outer tube 12 preferably has an opening aligned with the flange region 32 for accommodating the damping valve device 54a, so that the damping valve device 54a is fluidically connected to the compensation space 16.

[0047] The shock absorber 10 comprises, for example, another damping valve device 54b, which is fluidically 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 inside the inner tube 14. Preferably, the outer tube 12 and the intermediate tube 26 have openings aligned with the adapter for accommodating the damping valve device 54a. The damping valve devices 54a, 54b are, for example, identically constructed.

[0048] The piston rod 20 has, for example, an optional tension stop which, during a movement of the piston rod in the tension direction Z, is acted upon by a spring force via a spring element 42 .

[0049] Figure 2 An exemplary damping valve arrangement 54a, 54b is shown, which is preferably arranged as an external valve at least partially outside the outer tube 12 of the shock absorber 10. The damping valve arrangement 54a, 54b comprises a preferably cylindrical damping valve housing having a Figure 1 4 and 5. The substantially tubular tube part 45 shown in the figure and the housing upper part 44 mounted on the tube part 45. The housing upper part 44 has, for example, a connection area 46, which has one or more connection contacts for supplying current to the damping valve device 54a, 54b. Preferably, the connection contacts for power supply are connected to the drive unit. The housing upper part 44 has, for example, a cylindrical cover section 56, to which a hollow cylindrical section 58 is connected, which hollow cylindrical section has, for example, a smaller diameter.

[0050] The damping valve device 54a, 54b has, for example, a drive region 48 and a valve region 50. The drive region 48 is, for example, arranged in the upper region of the damping valve device 54a, 54b, facing the housing upper part 44, and is preferably arranged substantially above the valve region 50. The drive region 48 preferably includes a drive device configured as an electromagnetic device. The electromagnetic device includes a winding 52, which has a plurality of coils made of conductive wire. The winding 52 is preferably inside the tube part 45 and is arranged concentrically with the tube part. The winding 52 is, for example, arranged inside the hollow cylindrical section 58 of the housing upper part 44, and is particularly close to the inner wall of the housing upper part 44. The housing upper part 44 is, for example, constructed of plastic, in particular of a non-magnetic or only very small magnetic material, preferably a magnetic insulator, or a material with high magnetic resistance. The winding 52, for example, includes a winding frame, on which the coils of the winding are wound. The winding 52 at least partially or completely surrounds a core chamber 60, which extends in the central axial direction. The core 62 is supported in the core chamber 60 so that it can move axially. The core 62 is preferably cylindrical and has a diameter slightly smaller than the diameter of the core chamber 60, so that the core 62 is preferably mounted slidably in the axial direction. For example, the core 62 includes a central core rod 65, which is, for example, tubular and extends through the core chamber 60 in the central axial direction. The core 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, in particular, configured to be open in the direction of the valve area 50. The pole tube 64 is preferably constructed of a magnetizable or magnetic material and, for example, has a magnetic barrier that is not shown.

[0051] The winding 52 is preferably designed and arranged in such a way that, when a current is applied to it, it forms a magnetic field having magnetic field lines which preferably run substantially in the axial direction in the magnetic core chamber 60. The magnetic core 62 is preferably made of a magnetizable or magnetic material and moves in the axial direction in accordance with the polarity of the magnetic field formed by means of the winding 52.

[0052] Pole tube elements are connected to the hollow cylindrical region of the pole tube 64 in the axial direction and coaxially to the hollow cylindrical region, which together form the pole tube 64, wherein the pole tube 64 is in particular designed in multiple parts, in one piece or in one piece. The pole tube 64 has an upper tubular region with an in particular constant inner diameter, which is preferably designed as a hollow cylinder and extends from the housing upper part 44 in the axial direction to beyond the magnetic core 62. The upper hollow cylindrical region is connected in the axial direction by a lower region with an enlarged diameter, wherein the outer surface of the pole tube 64 preferably extends to Figure 14 and at least partially bears against the tube part 45 and is fluid-tight relative to the tube part 45 via a sealing element 66. The pole tube 64 at least partially surrounds a valve region 50, which will be explained in more detail in the following description.

[0053] The valve area 50 comprises, for example, a main valve 68 and a pilot valve 70, as well as a valve inlet 72 for introducing hydraulic fluid into the damping valve devices 54a, 54b, and a valve outlet 74 for discharging hydraulic fluid from the damping valve devices 54a, 54b. 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 into the valve outlet 74. The main valve 68 comprises a main piston 76, which is arranged in an axially movable manner inside a main working chamber 78. The main valve 68 further comprises, for example, a housing component 80, which at least partially defines the main working chamber 78 and is configured for axially guiding the main piston 76. The main piston 76 is preferably inside the housing component 80 and is arranged concentrically with the housing component 80. 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 has in particular a flow through-opening 86 which extends through the main piston 76 and forms a fluid connection between the main control chamber 82 and the pilot control chamber 84 .

[0054] The valve inlet 72 is formed in particular in a flange region 88 of the damping valve device 54a, 54b, wherein the flange region 88 can preferably be connected to the outer tube 12, the inner tube 14 and / or the intermediate tube 26 of the shock absorber 10. A main valve seat 90 is formed on the flange region 88, against which the main piston 76 rests in a fluid-tight manner in the closed position of the main valve 68. In the open position of the main valve 68, the main piston moves away from the main valve seat 90 in the axial direction, so that 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.

[0055] The main piston 76 has a particularly central recess on its surface pointing in the direction of 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 control chamber 84. A spring element 94 is mounted on the side of the main piston 76 that faces away from the main valve seat 90, and the spring element is arranged in such a way that the spring element loads the main piston 76 with a spring force in the direction of the main valve seat 90. The spring element 94 is, for example, a preloaded spring having at least one or two spring washer groups, wherein the spring washer group is preferably configured in the shape of a disk, in particular as a disk spring. The spring element 94 preferably extends over the entire diameter of the pilot control chamber 84, in particular to the inner wall of the housing part 80.

[0056] The spring element 94 preferably rests on a central block 96 that is fixedly connected to the housing component 80. The central block 96 is, for example, arranged in the pilot control chamber 84 and supported on the housing component 80 or fixedly connected to the housing component. In the central block 96, a connecting channel 98 is preferably configured, which is used to connect the pilot control chamber 84 with the pilot working chamber 100 of the pilot valve 70. The connecting channel 98 preferably extends through the central block 96 in the center and in the axial direction. Preferably, the connecting channel 98 forms a fluid inlet connected to the pilot valve 70.

[0057] The pilot valve 70 comprises, for example, a slide 102, which is arranged axially movably inside the pilot working chamber 100. The slide 102 preferably rests on the magnetic core 62 with its end remote from the main valve 68, so that the movement of the magnetic core 62 and the slide 102 is coupled at least in the movement of the magnetic core 62 toward the slide 102. The slide 102 preferably rests on the central block 96 in the closed position of the pilot valve 70 so that the connecting channel 98 is completely closed by the slide 102. In the open position of the pilot valve 70, the slide 102 is lifted from the central block 96, so that the connecting channel 98 is released by the slide 102, and a fluid flow is generated 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 on the housing part 80 or is fixedly connected thereto. The pilot working chamber 100 is constructed inside the pilot housing component 104, wherein the inner wall of the pilot housing component is constructed as a contact surface preferably fluid-tight with the slider 102. The pilot housing component 104 is preferably constructed as an axial guide for the slider 102. The slider 102 has, for example, a T-shaped longitudinal section, wherein the slider 102 has a first region 103 facing the connecting channel 98, which has a larger cross section than the cross section of the connecting channel 98; and also has a second region 105 facing the magnetic core 62, which has a larger cross section than the cross section of the first region. The second region preferably extends over the entire cross section of the pilot working chamber 100.

[0058] Figure 3a and Figure 3b Detailed views of the pilot valve 70 are shown respectively. Figure 3a , the pilot valve 70 is shown in the closed position, wherein the slide 102 completely closes the connecting channel. Preferably, the slide 102 in the closed position abuts against a first valve seat 106, which is formed in the central block 96. The pilot valve 70 preferably has a first valve seat 106, against which the slide 102 abuts in the closed position of the pilot valve 70. Preferably, the slide 102 abuts against the first valve seat 106 with its first region 103.

[0059] In addition, the pilot valve 70 preferably has a spring element 108, which is arranged in a fixed position in the pilot valve 70 of the damping valve device 54a, 54b. The spring element 108 is, for example, a spring washer or a plurality of spring washers. The spring washer is preferably configured in a disc shape and is arranged coaxially with the slider 102. The disc-shaped spring washer is preferably connected to the pilot housing component 104 on the radially outer area, especially fixed on the pilot housing component. The radially inwardly directed area of ​​the spring washer is preferably elastically deformable. Preferably, the spring element 108 has a central, circular cutout 110, which is arranged coaxially with the slider 102 so that the magnetic core 62 can move axially through the cutout. The spring element 108 is, for example, clamped between the pole tube 64 and the pilot housing component 104.

[0060] The slide 102 of the pilot valve 70 preferably has at least one or more through-holes 112, which extend through the slide 102 in the axial direction and constitute a flow channel for the hydraulic fluid to pass through the slide 102. The through-hole 112, for example, only extends through the second region 105 of the slide 102 facing the spring element 108. Preferably, the spring element 108 extends radially beyond the through-hole 112, so that the spring element 108 covers the through-hole in the radial direction. The slide 102 is preferably movable in the axial direction toward the spring element 108 until the slide abuts against the spring element 108. The spring element 108 extends radially beyond the through-hole 112, so that the spring element 108 covers these through-holes in the radial direction. The through-hole 112 is preferably connected to the valve outlet 74 in terms of fluid technology, which is arranged downstream of the through-hole 112.

[0061] Preferably, the pilot valve 70 has a second valve seat 114, which is formed on the slide 102 and against which the spring element 108 rests in at least one position of the slide 102. When the pilot valve 70, in particular the slide 102, is in a position with a maximum displacement in the axial direction, the slide 102, in particular the second valve seat 114 of the pilot valve 70, preferably rests on the spring element 108. The slide 102 is preferably in such a position only when there is no current in the winding 52 and the magnetic core 62 has a maximum displacement in the axial direction relative to the winding 52. This position is referred to in professional terms as a "fail-safe" position, in particular a fail-safe position of the pilot valve 70.

[0062] The fail-safe position of the pilot valve 70 is Figure 3b . In the fail-safe position of the pilot valve 70, the slide 102, in particular the second valve seat 114, rests against the spring element 108. Preferably, the spring element 108, in particular the spring washer, is arranged such that the spring washer at least partially or completely closes the through-hole 112 in the fail-safe position of the pilot valve 70. When the pressure in the pilot working chamber 100 rises above the closing force of the spring element 108, the spring element 108 is lifted from the second valve seat 114, and the pilot valve 70 is in the open position.

[0063] During the operation of the damping valve device 54a, 54b, the hydraulic fluid flows into the main control chamber 82 through the valve inlet 72, wherein the main piston 76 is loaded with an opening force by the pressure in the main control chamber 82, and the main piston is moved axially upward. At this time, the main piston 76 is lifted from the main valve seat 90, and the hydraulic fluid flows to the valve outlet 74 through the main flow channel 92. At the same time, the hydraulic fluid flows to the pilot control chamber 84 through the flow through hole 86 in the main piston 76, and exerts a closing force on the main piston toward the main valve seat 90. The opening width of the main valve 68, in particular the cross section of the main flow channel 92, is determined by the closing force, and the cross section determines the damping force of the damping valve device 54a, 54b. The pressure in the pilot control chamber 84 is adjusted by the pilot valve 70, wherein the hydraulic fluid flows from the pilot control chamber 84 through the connecting channel 98 into the pilot working chamber 100, and the connecting channel is released by the slide 102. The opening width of the connecting channel 98 depends on the axial position of the slider 102, which is adjusted, in particular preset, by means of the magnetic winding 52. In the closed position of the pilot valve 70, the slider 102 preferably completely closes the connecting channel 98, so that the hydraulic pressure in the pilot control chamber 84 increases to a maximum value and closes the main valve 68, wherein the main piston 76 is pressed onto the main valve seat 90. In the open position of the pilot valve 70, the connecting channel 98 is at least partially released by the slider 102, so that the hydraulic flow flows through the flow hole 112 in the slider 102 and flows to the valve outlet 74 via the flow channel arranged downstream of the flow hole 112. In the current-free operation of the damping valve devices 54a, 54b, the position of the slider 102 of the pilot valve 70 is not preset by the winding 52, so that the slider is in a fail-safe position and the pilot valve 70 is in a fail-safe position. Figure 3a and Figure 3b In the fail-safe position of the embodiment of the embodiment, the through-hole 112 in the slide 102 is closed by the spring element 108, so that the pilot valve 70 is in the closed position, and the main piston 76 is also moved into the closed position. If the hydraulic pressure in the pilot working chamber 100 increases beyond the closing force of the spring element 108, the spring element 108 is lifted from the second valve seat 114 and the through-hole 112 is opened.

[0064] It is also conceivable that the pilot valve 70 is not in the closed position in the fail-safe position and the through-opening 112 is at least partially released from the spring element 108, so that the main valve 68 is also in the open position. In the fail-safe position of the pilot valve, the slide 102 preferably rests on the spring element 108 in such a way that the through-opening 112 is closed or partially released.

[0065] Figure 3c A further embodiment of a damping valve arrangement 54a, 54b is shown, wherein this embodiment corresponds substantially to Figure 3a and3b As shown in . Figure 3a and Figure 3b The pilot valve is different in that Figure 3c The pilot valve 70 additionally has a preload element 138. The preload element 138 is, for example, a helical spring or a disk spring, which is particularly arranged and constructed in such a way that it applies a preload force to the slider 102 in the direction of the magnetic core 62. For example, the preload element 138 rests with its end on the center block 96 and with its opposite end on the slider 102, in particular on the second region 105 of the slider 102. Preferably, the preload element 138 constructed as a helical spring or a disk spring is arranged coaxially with the slider 102. Such a preload element 138 improves operational safety and ensures that the slider 102 reliably moves in the direction of the magnetic core 62 and thus reaches a fail-safe position in a current-free operating state.

[0066] Figure 4 A vibration damper 10 is shown, which is substantially similar to Figure 1 The damping valve device 54c is arranged on the working piston 18. Figure 1 The difference is, Figure 4 The shock absorber 10 does not have an intermediate pipe and external damping valve devices 54 a , 54 b .

[0067] Figure 5 The damping valve device 54c also comprises a drive region 48 having a winding 52 and a magnetic core 62 which is axially movable in the winding, as shown in FIG. Figure 2 The damping valve device 54c also has a valve region 50, which has a main valve 68 and a pilot valve 70. For example, the damping valve device 54c has two main valves 68a, 68b, which are each arranged on one side of the working piston 18, so that the main valve 68a or 69b is respectively effective in the pulling phase or the pushing phase of the shock absorber 10.

[0068] The working piston 18 has a fluid through-hole 116, which leads into the main control chamber 118 of the main valve 68. The main piston 120 separates the main control chamber 118 from the pre-control chamber 122 in terms of fluid technology. A main valve seat 124 is constructed on the working piston 18 or on a component fixedly connected to the working piston, against which the main piston 120 abuts in the closed position of the corresponding main valve 68. For example, a spring washer is arranged on the main piston 120, which abuts directly on the main valve seat 124. It is also conceivable that the main piston 120 abuts directly on the main valve seat 124. 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 pre-control chamber 122. For example, the pre-control chambers 122 of the two main valves 68a, 68b are connected to each other via a flow channel, so that preferably the same pressure exists in the pre-control chambers 122 of the main valves 68a, 68b. The pressure prevailing in the two pilot control chambers 122 can preferably be adjusted by means of the pilot valve 70. The pilot valve 70 has a slide 126 which is mounted axially movable and which, in the closed position of the pilot valve 70, bears against a first valve seat of the pilot valve 70. The pilot control chambers 122 are hydraulically connected to a pilot working chamber 132, for example, via a connecting channel 130. The flow cross section of the connecting channel 130 can be at least partially or completely closed by means of the slide 126, wherein the slide 126 bears against a first valve seat 128 of the pilot valve 70. The movement of the slide 126 is preferably coupled to the magnetic core 62 at least in one direction of movement, and as described with reference to Figure 1 As described with reference to FIG. 3 , the slider is moved axially by the winding 52 .

[0069] The primary piston 120 is preferably arranged movably relative to a fixed flange area 134. A flow through hole 136 is formed in the flange area 134, which connects the pilot control chamber 122 to the corresponding working chamber 22, 24 of the shock absorber 10. The flow through holes 136 are preferably connected to a check valve in each case, so that the hydraulic flow can only flow from the corresponding working chamber 22, 24 into the corresponding pilot control chamber 122, but not in the opposite direction.

[0070] When the working piston 18 moves in the thrust direction D, the hydraulic fluid flows, for example, from the working chamber 24 remote from the piston rod via the flow through hole 136 of the main valve 68b into one of the pilot control chambers 122, so that the same pressure is present in the two pilot control chambers through the hydraulic connection of the pilot control chambers 122. The discharge of the hydraulic fluid is determined by the position of the slide 126 relative to the first valve seat 128 via the pilot valve 70 and thus the set pressure in the pilot control chamber 122. Figure 5 The pilot working chamber 132 of the exemplary embodiment of 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 .

[0071] Figure 6a A detailed view of the pilot valve 70 of the damping valve arrangement 54 c is shown. Figure 6a The fail-safe position of the pilot valve 70 described above is shown. The pilot valve 70 of FIG. 6 corresponds essentially to the pilot valve of FIG. 3 . The pilot valve 70 likewise has a spring element 140 which, for example, comprises at least one or more spring washers. The spring element 140 is preferably designed in the form of a disk, so that it has a central cutout 142. Unlike the pilot valve 70 of FIG. 3 , the cutout 142 in the spring element 140 is not arranged coaxially with the slide 126, but is arranged radially offset relative to the central longitudinal axis of the slide 126. As shown in FIG. Figure 1 As described in FIG. 3 , the spring element 140 is arranged in a fixed position and fixed in the radially outer region. The pilot valve 70 of FIG. 6 also has a second valve seat 144, which is constructed on the side of the slider 126 facing the magnetic core and on which the spring element 140 can be abutted. Different from FIG. 3 , Figure 6a The slide 126 has a diameter that is smaller than the diameter of the pilot working chamber 132, so that when the pilot valve 70 is in the open position, the hydraulic fluid can flow through the slide 126, in particular to the outflow channel 148 and thus to the valve outlet. In the fail-safe position of the pilot valve 70, the spring element 140 interacts with the second valve seat 144 formed in the slide 126 in such a way that, for example, no hydraulic flow or only a limited hydraulic flow reaches the valve outlet between the slide 126 and the spring element 140. For example, the spring element 140 rests on the second valve seat 144 in such a way that no hydraulic fluid can flow to the valve outlet 74. If the hydraulic pressure in the pilot working chamber 132 rises above the opening pressure of the spring element 140, the spring element is lifted from the second valve seat 144 and preferably interacts with the second valve seat 144 in such a way that at least a small amount of hydraulic fluid can flow from the pilot working chamber 132 to the valve outlet 74.

[0072] The second valve seat 114, 144 of the pilot valve 70 of the embodiment of FIG. 3 or FIG. 6 has, for example, a control edge, on which the spring element 140 abuts. The control edge is particularly configured as an axial projection and preferably extends in the direction of the magnetic core 62. For example, the control edge is configured as a partially annular or fully circular axial projection. Preferably, the spring elements 108, 140 abut only on the control edge. This prevents the spring element from sticking or adhering to the slider 126. The control edge is, for example, arranged radially inwardly relative to the through-hole 112 in the slider 102.

[0073] The pilot working chamber 132 is separated from the outflow channel 148 in terms of fluid technology, for example, by means of a closing disk 150, wherein the first valve seat 128 of the pilot valve 70 is, for example, configured in the closing disk 150 and cooperates with the slide 126. The closing disk 150 preferably has a cutout through which the slide 126 extends. The pilot valve 70 preferably has an axial stop, in particular in the fail-safe position of the pilot valve 70, for the slides 126, 144 to abut against it. The axial stop is configured, for example, by the magnetic core 62 and / or the spring elements 108, 140.

[0074] For example, a bypass channel (not shown in the drawings) is formed in the slider 126, 144, in particular in the control edge, or in the spring element 108, 140, which connects the pilot working chamber to the valve outlet. Such a bypass channel is advantageous in that even when the pilot valve 70 is closed in the fail-safe position of the pilot valve, a bypass flow can exist and thus preferably a slight damping is achieved.

[0075] The spring elements 108, 140 preferably have a stiffness that varies, in particular increases, depending on the stroke. For example, the spring elements 108, 140 are arranged so that in the fail-safe position of the pilot valve 70, the spring elements abut against the second valve seat 114 / 144 in a position prestressed in the direction of the second valve seat 114 / 144.

[0076] Figure 6b Another embodiment of the pilot valve 70 of the damping valve device 54c is shown. Figure 6a Unlike the pilot valve 70 of the embodiment of the present invention, the second valve seat 144 of the pilot valve 70 is constructed on a closing gasket 150. A spring element 140 is mounted on the closing gasket 150, for example, and the spring element is preferably constructed as a spring gasket. In particular, the closing gasket 150 has at least one or more fluid channels 152, which are used to connect the pilot working chamber 132 with the outflow channel 148. The spring element 140 is arranged and constructed in such a way that when the hydraulic pressure inside the pilot working chamber 132 is lower than a specific value, the spring element at least partially or completely closes the fluid channel 152. If the hydraulic pressure in the pilot working chamber 132 exceeds a specific pressure, especially the opening pressure of the spring element 140 constructed as a spring gasket, the spring element is lifted from the second valve seat 144 and at least partially releases the fluid channel 152.

[0077] In the de-energized operating state of the pilot valve 70, the slide 126 is preferably moved in the direction of the magnet core 62 by means of the hydraulic pressure in the pilot working chamber 132 or the preload element 138, so that the slide 126 rests against the magnet core and in particular against stationary parts of the pilot valve 70 in a fluid-tight manner, so that no hydraulic fluid can flow through the slide 126 into the outflow channel 148. The spring element 140 is preferably designed in such a way that the opening pressure is less than the hydraulic pressure set in the pilot working chamber 132 in the de-energized operation. Preferably, the opening pressure is greater than the hydraulic pressure prevailing within the pilot working chamber 132 during normal operation, so that the spring element 140 is opened only in the fail-safe operation.

[0078] Figure 7 Show according to Figure 5 Another embodiment of a damping valve device 54c is shown, wherein only a partial view of the damping valve device 54c is shown. Figure 5 The difference between the damping valve device in the embodiment of the present invention is the preload element 138, which is arranged and constructed so that according to the reference Figure 3c According to the described principle of action, the preload element applies a preload force to the slide 126 in the direction of the magnet core 62 .

[0079] Description of Reference Numerals

[0080] 10. Shock absorber

[0081] 12 outer tube

[0082] 14 Inner tube

[0083] 16 Compensation space

[0084] 18 Working piston

[0085] 20 piston rod

[0086] 22 First / piston rod side working chamber

[0087] 24 Second / working chamber away from the piston rod

[0088] 26 Intermediate pipe

[0089] 28 Ring Space

[0090] 30 through holes

[0091] 32 Flange area

[0092] 34 closed components

[0093] 36 bottom parts

[0094] 38 foot valve

[0095] 40 Adapter

[0096] 42 Spring element

[0097] 44 Shell upper part

[0098] 45 pipe parts

[0099] 46 Wiring area

[0100] 48 drive area

[0101] 50 valve area

[0102] 52 Winding

[0103] 54a, 54b, 54c Damping valve device

[0104] 56 Top cover section

[0105] 58 hollow cylindrical section

[0106] 60 core chamber

[0107] 62 core

[0108] 64 diodes

[0109] 65 magnetic core rod

[0110] 66 Sealing element

[0111] 68 Main valve

[0112] 70 pilot valve

[0113] 72 valve inlet

[0114] 74 valve outlet

[0115] 76 / 120 main piston

[0116] 78 Main working chamber

[0117] 80 Shell parts

[0118] 82 / 118 Main control chamber

[0119] 84 / 122 Pre-control chamber

[0120] 86 / 136 Flow Through Hole

[0121] 88 / 134 flange area

[0122] 90 / 124 main valve seat

[0123] 92 Main flow channel

[0124] 94 Spring element

[0125] 96 center block

[0126] 98 / 130 connection channel

[0127] 100 / 132 pilot working chamber

[0128] 102 / 126 Slide

[0129] 103 The first area of ​​the slider

[0130] 104 pilot housing parts

[0131] 105 The second area of ​​the slider

[0132] 106 / 128 First valve seat of pilot valve 70

[0133] 108 / 140 Spring element

[0134] 110 / 142 Cutout in spring element 108

[0135] 112 Through hole

[0136] 114 / 144 Second valve seat of pilot valve 70

[0137] 116 Fluid passage hole in working piston 18

[0138] 118 Main control chamber

[0139] 136 Flow Through Holes

[0140] 138 preload element

[0141] 148 Outflow channel

[0142] 150 closed gasket

[0143] 152 Fluid Channels

Claims

1. A damping valve device (54a, 54b, 54c) for a shock absorber (10) of a motor vehicle, comprising: Winding (52), an axially movable magnetic core (62) arranged at least partially inside the winding (52), A main valve (68) having a main piston (76; 120) which fluidically separates a main control chamber (82; 118) and a pilot control chamber (84; 122) from one another, A pilot valve (70) having a pilot working chamber (100, 132) and a slider (102; 126) arranged in the pilot working chamber (100; 132), the slider being axially movable by means of a magnetic core (62), and A connecting channel (98; 130) is arranged between the pilot control chamber (84; 122) and the pilot working chamber (100; 132) and connects the two to each other in terms of fluid technology, in, The pilot valve (70) has a first valve seat (106; 128), against which the slide (102; 126) bears in the closed position of the pilot valve (70), so that the connecting channel (98; 130) is closed in a fluid-tight manner by the slide (102; 126). It is characterized in that The pilot valve (70) has a spring element (108, 140), and The pilot valve (70) has a second valve seat (114, 144), with which the spring element (108; 140) interacts, in particular in a fail-safe position of the pilot valve (70) in which the winding (52) is de-energized.

2. The damping valve device (54a, 54b, 54c) according to claim 1, characterized in that A second valve seat (114, 144) of the pilot valve (70) is configured on the slide (102; 126).

3. The damping valve device (54c) according to any one of the preceding claims, characterized in that The pilot valve (70) has a fluid channel (152) for fluidically connecting a pilot working chamber (132) to a valve outlet, and wherein a spring element (140) is constructed and arranged on the fluid channel (152) in such a way that the spring element releases the fluid flow in a fail-safe position of the pilot valve (70) and blocks the fluid flow in a position of the pilot valve (70) that is different from the fail-safe position.

4. The damping valve device (54a, 54b, 54c) according to any one of the preceding claims, characterized in that The spring element (108, 140) has at least one spring washer.

5. The damping valve device (54a, 54b, 54c) according to any one of the preceding claims, characterized in that The spring element (108, 140) has a central cutout (110; 142) through which the magnetic core (62) can move in the axial direction.

6. The damping valve arrangement (54a, 54b) according to any one of the preceding claims, characterized in that The slide (102) of the pilot valve (70) has at least one or more flow holes (112), which extend through the slide (102) in the axial direction and constitute a flow channel for hydraulic fluid to pass through the slide (102), and wherein the spring element (108) extends radially beyond the flow hole (112) so that the flow hole can be at least partially or completely closed by the spring element (108) in the fail-safe position of the pilot valve (70).

7. The damping valve device (54c) according to claim 5, characterized in that The slide block (126) is arranged radially offset relative to the central cutout (110; 142).

8. The damping valve device (54a, 54b, 54c) according to any one of the preceding claims, characterized in that A second valve seat (114, 144) of a pilot valve (70) has a control edge with which a spring element (108, 140) interacts, wherein the control edge is designed as an axial projection.

9. The damping valve device (54a, 54b, 54c) according to any one of claims 6 to 8, characterized in that The control edge is arranged radially inwardly relative to a through-opening (112) in the slide (102).

10. The damping valve arrangement (54a, 54b, 54c) according to any one of the preceding claims, characterized in that The pilot valve (70) has an axial stop, which serves to cause a slide (126, 144) to abut against it in a fail-safe position of the pilot valve (70).

11. The damping valve device (54a, 54b, 54c) according to claim 10, characterized in that The axial stop is formed by the magnetic core (62) and / or the spring element (108; 140).

12. The damping valve device (54a, 54b, 54c) according to any one of the preceding claims, characterized in that The spring element (108, 140) is arranged in such a way that in the fail-safe position of the pilot valve (70), the spring element is prestressed in the direction of the second valve seat (114; 144).

13. The damping valve device (54a, 54b, 54c) according to any one of the preceding claims, characterized in that The pilot valve (70) comprises a preload element (138) which is arranged and designed in such a way that it applies a preload force to the slide (102; 126).

14. The damping valve device (54a, 54b, 54c) according to any one of the preceding claims, characterized in that A bypass channel is formed in the slide (102, 126), in particular in the control edge, or in the spring element (108, 140), which connects the pilot working chamber (100; 132) to the valve outlet (74), thereby discharging hydraulic fluid from the damping valve device (54a, 54b, 54c).

15. A shock absorber (10) for a motor vehicle, comprising: An outer tube (12), an inner tube (14) arranged coaxially with the outer tube, and a working piston (18) arranged axially movable inside the inner tube (14), the working piston dividing the inner cavity of the inner tube (14) into a working cavity (22) on the piston rod side and a working cavity (24) away from the piston rod, It is characterized in that The shock absorber has a damping valve arrangement (54a, 54b, 54c) according to any of the preceding claims.

Images