CN119508413A - Damping valve device for a shock absorber of a motor vehicle - Google Patents

Abstract

The invention comprises a damping valve device for a shock absorber of a motor vehicle and a shock absorber. The 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 pre-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, and the spring element cooperates with the second valve seat in the fail-safe position of the pilot valve.

Description

Damping valve device for a shock absorber of a motor vehicle

Technical Field

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

DE 10 2020 215 480 A1 discloses a shock absorber with a damper valve device, wherein the damper valve device has a main valve and a pilot valve which can be adjusted by a magnetic winding. In the event of a power failure of the magnetic winding, the pilot valve is moved into a fail-safe position, in which the hydraulic pressure in the pre-control chamber of the main valve is typically relieved via lateral flow channels, which can only flow hydraulic fluid in the fail-safe position. The manufacture of such flow channels is costly.

Disclosure of Invention

The object of the present invention is therefore to provide a damping valve arrangement for a shock absorber which makes it possible to regulate the hydraulic pressure at the main valve even in a fail-safe position and which can be produced cost-effectively.

According to the invention, this object is achieved by a damping valve device having the features of independent device claim 1. Advantageous developments emerge from the dependent claims.

According to a first aspect, a damping valve arrangement for a shock absorber of a motor vehicle comprises a winding, an axially movable magnetic core which is arranged at least partially inside the winding, a main valve with a main piston which fluidically separates the main control chamber and the pre-control chamber, a pilot valve with a pilot working chamber and a slide arranged in the pilot working chamber, which slide is axially movable 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 interconnects the latter, wherein the pilot valve has a first valve seat against which the slide rests in a closed position of the pilot valve, such that the connecting channel is fluidically sealed off by the slide. The pilot valve has a spring element, wherein the pilot valve has a second valve seat, with which the spring element interacts in a fail-safe position of the pilot valve, in which the winding is currentless. Preferably, the spring element is arranged such that it interacts with the second valve seat only in the fail-safe position of the pilot valve. Preferably, the spring element does not co-act with the second valve seat when the winding is energized. The spring element, in particular, rests at least partially or completely against the second valve seat when the pilot valve is in the fail-safe position. Preferably, the spring element cooperates 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 hydraulic fluid from the damping valve arrangement.

The arrangement of the second valve seat in the pilot valve offers the advantage that a controlled outflow of hydraulic fluid from the pilot working chamber can be achieved even in the fail-safe position of the pilot valve and thus that the pressure in the pilot chamber of the main valve can be regulated even when the coil is currentless. Furthermore, costly and expensive lateral outflow channels can be dispensed with.

The damping valve device is arranged, for example, in a shock absorber for a motor vehicle. The damper is, for example, a multi-tube damper, such as a double tube damper. The damper comprises, for example, an outer tube which forms the outer surface of the damper, in particular the housing. Inside the outer tube, an inner tube, also called a damping tube, is arranged coaxially with the outer tube. A compensating space is formed between the outer tube and the inner tube, which is preferably at least partially filled with hydraulic fluid. For example, the compensation space is partially filled with gas.

The working piston connected to the piston rod is preferably arranged inside the inner tube such that the working piston can move in the inner tube, wherein the inner tube is preferably configured as a guide for the working piston. The damping valve device according to the invention is arranged, for example, on the working piston. The working piston divides the inner space of the inner tube, in particular, into a first working space on the piston rod side and a second working space remote from the piston rod.

The damping valve device is for example arranged at least partially outside the outer tube of the shock absorber. With such an external arrangement of the damping valve device, an intermediate tube is optionally arranged inside the compensation space, which is coaxial with and arranged between the inner tube and the outer tube. The damping valve device is mounted, for example, on the intermediate pipe. The intermediate pipe is preferably mounted in a fluid-tight manner on the inner pipe, wherein an annular space is formed between the intermediate pipe and the inner pipe. The intermediate pipe preferably has a flange region for mounting the damper valve arrangement to the intermediate pipe, which flange region is preferably configured as a fluid inlet and/or a fluid outlet of the damper valve arrangement. The outer tube preferably has an opening aligned with the flange region for receiving the damping valve device, so that the damping valve device is fluidically connected to the compensation space. For example, the shock absorber has a further damping valve device, which is for example likewise arranged outside the outer tube. Preferably, the further damping valve device is fluidically 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. These damping valve arrangements are preferably identically constructed.

The shock absorber preferably has a closure assembly which seals the interior space of the outer tube laterally in the piston rod side fluid. Opposite the closure assembly, the interior space of the outer tube is preferably sealed fluid-tightly by means of a base part at the end remote from the piston rod. A base valve is arranged in particular on the base part, which is mounted at the end of the inner tube remote from the piston rod.

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

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

The damping valve means preferably comprises a main valve and a pilot valve, and in particular a valve inlet for introducing hydraulic fluid into the damping valve means and a valve outlet for discharging hydraulic fluid from the damping valve means. The pilot valve is preferably arranged downstream of the main valve. In particular, the damping valve arrangement allows hydraulic fluid to pass through in only one direction.

The main valve preferably comprises a main piston which is arranged axially displaceably inside the main working chamber. The main valve optionally comprises a housing part which at least partially delimits the main working chamber and which forms an axial guide for the main piston. The main piston is preferably arranged such that it separates the main control chamber and the pre-control chamber from each other, wherein the main piston optionally has a flow through opening which extends through the main piston and which forms a fluid connection of the main control chamber and the pre-control chamber. Alternatively, the pre-control chamber is fluidically connected to the first or second working chamber of the shock absorber via a flow through opening.

For external damping valve devices 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 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 formed, for example, on the flange region and against 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, the main piston is lifted from the main valve seat in the axial direction, in which position 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 outlet and the valve inlet, in particular with the main control chamber.

On the side of the main piston remote from the valve seat, a spring element is preferably mounted, which is arranged such that it exerts a spring force on the main piston in the direction of the main valve seat. The spring element is, for example, a pretensioned spring with one or at least two spring washer groups, wherein the spring washer groups are preferably configured as a disk, in particular as a disk spring.

The damping valve arrangement preferably comprises a connecting channel for connecting the pre-control chamber with the pilot working chamber of the pilot valve. The connecting channel is preferably formed in the housing part or in a region which 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.

The pilot valve preferably comprises a slide which is arranged axially movably inside the pilot working chamber. The end of the slide facing away from the main valve preferably bears against the magnetic core, so that the movements of the magnetic core and the slide are 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 in such a way 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 established between the pilot control chamber and the pilot working chamber of the main valve.

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

According to the first embodiment, the second valve seat of the pilot valve is configured on the slider. The slider preferably has a second valve seat on its side facing the magnetic core, against which a spring element, in particular a spring washer, can rest. The valve seat is, for example, designed as a flat surface, so that the spring washer preferably rests flat against the valve seat. The construction 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.

According to a further embodiment, the pilot valve has a fluid channel for fluidically connecting the pilot working chamber with the valve outlet, wherein the spring element is constructed and arranged on the fluid channel such that it releases the fluid flow in a fail-safe position of the pilot valve and prevents the fluid flow in a position of the pilot valve which is different from the fail-safe position. The pilot working chamber is preferably fluidically connected to an outflow channel, through which hydraulic fluid can flow from the pilot working chamber into the valve outlet, in particular into the first or second working chamber.

The pilot working chamber is fluidically separated from the outflow channel, in particular by means of a closing washer, wherein the closing washer preferably has a cutout through which the slide extends. For example, the first valve seat of the pilot valve is formed on the closing washer and cooperates with the slide. For example, the second valve seat of the pilot valve is likewise formed on a closing washer, on which the spring element is mounted. In particular, the closing washer has at least one or more fluid channels for connecting the pilot working chamber with the outflow channel. The spring element is arranged and constructed, for example, in such a way that it at least partially or completely closes the fluid channel when the hydraulic pressure inside the pilot working chamber is below a certain value. If the hydraulic pressure in the pilot working chamber exceeds a specific pressure, in particular the opening pressure of a spring element in the form of a spring washer, the spring element lifts off from the second valve seat and at least partially releases the fluid channel. The spring element is preferably designed such that the opening pressure is lower than the set hydraulic pressure in the pilot chamber during no-current operation. Preferably, the opening pressure is greater than the hydraulic pressure prevailing inside the pilot chamber during normal operation, so that the spring element is configured such that it opens only during fail-safe operation.

According to a further 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 stiffness. The spring washers are preferably arranged parallel and coaxially to each other and in particular lie against each other.

According to a further embodiment, the spring element, in particular at least one or all of the spring washers, has a central circular cutout, which is arranged coaxially to the slider and/or the magnetic core in such a way that the magnetic core can be moved axially through the cutout. The spring element is preferably arranged in a fixed position, wherein the magnetic core and the slider are mounted in a movable manner relative to the spring element. It is thereby achieved that the spring element only rests against the valve seat in a specific axial position of the slide and that no or only very little influence is exerted on the flow of hydraulic fluid in the remaining position of the slide, preferably in the remaining position reached in normal operation of the damping valve device.

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

According to a further embodiment, the slide is arranged radially offset with respect to the central cutout. Preferably, the central longitudinal axes of the slider 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 chamber.

According to a further embodiment, the second valve seat of the pilot valve has a control edge with which the spring element interacts, and wherein the control edge is configured as an axial projection. The control edge is preferably the region of the valve seat against which the spring element, in particular the spring washer, can rest. The control edge, which is configured as an axial projection, for example, extends in the axial direction relative to the magnetic core and is optionally configured as a ring, for example as a partial circle or as a complete circle. The axial height of the control edge is preferably designed such that the spring element rests in a relaxed or preloaded manner against the control edge in the fail-safe position of the pilot valve. The slide has, for example, a diameter smaller than the diameter of the pilot working chamber, wherein the control edge is arranged on a radially outwardly directed region of the slide.

According to a further embodiment, the control edge is arranged radially inwards relative to the through-flow opening in the slide. This achieves an optimal interaction of the spring element with the control edge of the second valve seat.

According to another embodiment, the pilot valve has an axial stop for the slider to rest against in a fail-safe position of the pilot valve. This achieves an optimal positioning of the slider in the fail-safe position of the pilot valve.

According to a further embodiment, the axial stop is formed by a magnetic core and/or a spring element. According to a further embodiment, the spring element is arranged such that, in a fail-safe position of the pilot valve, the spring element rests against the second valve seat in a position that is pretensioned in the direction of the second valve seat. For example, the axial stop is formed by a magnetic core, which is spaced apart from the spring element in the axial direction in such a way that the spring element is preloaded by the slide in the fail-safe position.

According to a further embodiment, the pilot valve comprises a pre-tightening element which is arranged and constructed such that it applies a pre-tightening force to the slide. The prestressing element is, for example, a helical spring or a spiral spring, which is arranged and constructed in particular such that the prestressing element applies a prestressing force to the slider in the direction of the magnetic core. Preferably, the pretensioning element in the form of a spiral spring or coil spring is arranged coaxially to the slider. Such a pretensioning element increases the operational safety and ensures that the slider is reliably moved toward the magnetic core and thus reaches a fail-safe position in the currentless operating state.

According to a further embodiment, a bypass channel is formed in the slide, in particular in the control edge, or in the spring element, which connects the pilot working chamber to the valve outlet for discharging hydraulic fluid from the damping valve device. In this way, even in the closed position, in which the spring element rests against the second valve seat of the pilot valve, a flow of hydraulic fluid to the valve outlet is additionally achieved.

The invention also includes a shock absorber having a damping valve arrangement as described above, wherein the damping valve arrangement is arranged, for example, on the working piston and/or at least partially outside the outer tube.

Drawings

The invention is explained in detail below with reference to the drawings by means of several embodiments.

Fig. 1 shows a schematic view of a shock absorber according to one embodiment in a longitudinal section.

Fig. 2 shows a schematic view of a damping valve device according to another embodiment in a longitudinal section.

Fig. 3a, 3b and 3c show schematic diagrams of pilot valves of damping valve arrangements according to other embodiments in longitudinal sectional views, respectively.

Fig. 4 shows a schematic view of a shock absorber according to one embodiment in a longitudinal section.

Fig. 5 shows a schematic view of a damping valve device according to another embodiment in a longitudinal section.

Fig. 6a and 6b show schematic diagrams of a pilot valve of a damping valve device according to another embodiment in longitudinal sectional views, respectively.

Fig. 7 shows a partial schematic view of a damping valve device according to another embodiment in a longitudinal sectional view.

Detailed Description

Fig. 1 shows a damper 10, wherein the damper 10 is a multi-tube damper, such as a dual tube damper. Shock absorber 10 has an outer tube 12 that forms an outer surface, particularly a shell, of shock absorber 10. Inside the outer tube 12, an inner tube 14 is arranged coaxially with the outer tube, which may also be referred to as a damping tube. Between the outer tube 12 and the inner tube 14, a compensation space 16 is formed, which is preferably at least partially filled with hydraulic fluid. For example, the compensating space 16 is partially filled with gas.

The working piston 18 connected to the piston rod 20 is arranged inside the inner tube 14 in such a way that it 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, an intermediate tube 26 is arranged between the inner tube 14 and the outer tube 12 coaxially therewith.

The interior of the outer tube 12 is sealed on the piston rod side by means of a closure assembly 34 in a fluid-tight manner. Opposite the closure assembly 34, the interior of the outer tube 12 is sealed fluid-tightly by means of a bottom part 36 at the end remote from the piston rod. A foot valve 38 is arranged, for example, on the bottom part 36, which foot valve is mounted in particular on the end of the inner tube 14 remote from the piston rod. The bottom valve 38 is, for example, a check valve that is capable of allowing fluid to pass through in two directions or only in one direction. Second working chamber 24 is preferably fluidically connected to compensating space 16 via a base valve 38. The ends of the inner tube 14 and the outer tube 12 on the piston rod side are preferably fastened to the closure assembly 34.

The intermediate tube 26 is preferably fluid-tightly mounted on the inner tube 14. An annular space 28 is formed between the intermediate tube and the inner tube 14. At least one through-hole 30 is formed in inner tube 14, which through-hole 30 fluidically connects first working chamber 22 with annular space 28.

The intermediate pipe 26 illustratively has a flange region 32 for mounting the damper valve assembly 54a on the intermediate pipe 26. The flange region 32 forms a receptacle for the damper valve arrangement 54a, and the flange region 32 forms, in particular, a fluid inlet and/or a fluid outlet of the damper valve arrangement 54 a. The flange region 32 connects the annular space 28 with a damping valve device 54a, for example. The outer tube 12 preferably has an opening aligned with the flange region 32 for receiving the damping valve device 54a, so that the damping valve device 54a is fluidically connected to the compensation space 16.

Shock absorber 10 comprises, for example, a further damping valve device 54b which is fluidically connected to inner tube 14, in particular to working chamber 24 remote from the piston rod, by means of an adapter 40 mounted inside inner tube 14. Preferably, the outer tube 12 and intermediate tube 26 have openings aligned with the adapter for receiving the damper valve assembly 54a. The damping valve devices 54a, 54b are, for example, identically constructed.

The piston rod 20 has, for example, an optional pull stop which is acted upon by a spring force by the spring element 42 when the piston rod is moved in the pull direction Z.

Fig. 2 shows exemplary damping valve arrangements 54a, 54b, which are preferably provided as external valves, at least partially arranged outside the outer tube 12 of the shock absorber 10. The damper valve arrangement 54a, 54b comprises a preferably cylindrical damper valve housing having a substantially tubular pipe part 45 shown in fig. 1 and a housing upper part 44 mounted on the pipe part 45. The housing upper part 44 has, for example, a connection region 46 with one or more connection contacts for supplying the damping valve arrangement 54a, 54b with current. Preferably, the connection contacts for supplying power are connected to the drive unit. The housing upper part 44 has, for example, a cylindrical top cover section 56, to which a hollow cylindrical section 58 is connected, which has, for example, a smaller diameter.

Damping valve arrangements 54a, 54b have, for example, a drive region 48 and a valve region 50. The drive region 48 is arranged, for example, in an upper region of the damping valve arrangement 54a, 54b, which is oriented toward the housing upper part 44, and is preferably arranged essentially above the valve region 50. The drive region 48 preferably comprises a drive device configured as an electromagnetic device. The electromagnetic device includes a winding 52 having a plurality of coils made of electrically conductive wire. The windings 52 are preferably inside the tube part 45 and are arranged concentrically with the tube part. The winding 52 is arranged, for example, inside a hollow cylindrical section 58 of the housing upper part 44 and in particular rests against the inner wall of the housing upper part 44. The housing upper part 44 is constructed, for example, from plastic, in particular from a non-magnetic or only very magnetically small material, preferably a magnetic insulator, or a material with a high magnetic resistance. The winding 52 comprises, for example, a winding frame on which the coils of the winding are wound. The winding 52 at least partially or completely encloses a core chamber 60 which extends centrally in the axial direction. The core 62 is axially movably supported inside the core chamber 60. The magnetic core 62 is preferably configured cylindrically and has a diameter slightly smaller than the diameter of the magnetic core chamber 60, so that the magnetic core 62 is preferably slidably mounted in the axial direction. For example, the core 62 comprises a central core rod 65, which is for example of tubular design and extends centrally in the axial direction through the core chamber 60. 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 designed to open in the direction of the valve region 50. The pole tube 64 is preferably constructed from magnetizable or magnetic material and has, for example, magnetic barriers, not shown.

The windings 52 are preferably configured and arranged such that, when a current is applied, they form a magnetic field having magnetic field lines which preferably run in the core chamber 60 essentially in the axial direction. The core 62 is preferably constructed of magnetizable or magnetic material and moves in the axial direction in response to the polarity of the magnetic field formed by the windings 52.

In the hollow cylindrical region of the pole tube 64, pole tube elements are connected 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 constructed in multiple parts, in one piece or in one piece. The pole tube 64 has an upper tubular region, which has a particularly constant inner diameter, is preferably configured as a hollow cylinder and extends from the housing upper part 44 in the axial direction beyond the magnetic core 62. At the upper hollow-cylindrical region, a lower region with an enlarged diameter is connected in the axial direction, wherein the outer surface of the pole tube 64 preferably extends onto the tube part 45 shown in fig. 1 and at least partially rests on the tube part and is fluid-tight with respect to the tube part 45 by means of the sealing element 66. The pole tube 64 at least partially encloses the valve region 50, which valve region 50 will be explained in more detail in the following description.

The valve area 50 comprises, for example, a main valve 68 and a pilot valve 70, a valve inlet 72 for introducing hydraulic fluid into the damping valve arrangement 54a, 54b, and a valve outlet 74 for discharging hydraulic fluid from the damping valve arrangement 54a, 54 b. During operation of the damping valve, hydraulic fluid, particularly pilot flow, preferably flows from the valve inlet 72 into the main valve 68, then into the pilot valve 70, and then to the valve outlet 74. The main valve 68 comprises a main piston 76 which is arranged axially movable inside a main working chamber 78. The main valve 68 further includes, for example, a housing member 80 at least partially defining the main working chamber 78 and configured for axially guiding the main piston 76. The master piston 76 is preferably inside the housing member 80 and is arranged concentrically with the housing member 80. The main piston 76 preferably divides the main working chamber 78 into a main control chamber 82 and a pre-control chamber 84, wherein the main piston 76 has, in particular, a flow bore 86 which extends through the main piston 76 and forms a fluid connection of the main control chamber 82 to the pre-control chamber 84.

Valve inlet 72 is formed in particular in a flange region 88 of damping valve arrangement 54a, 54b, wherein flange region 88 can be preferably connected to outer tube 12, inner tube 14 and/or intermediate tube 26 of shock absorber 10. A main valve seat 90 is formed on the flange region 88, the main piston 76 bearing in a fluid-tight manner against this main valve seat 90 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, lifting the main piston 76 from the main valve seat 90 such that a main flow passage 92 is formed between the main piston 76 and the main valve seat 90. The main flow passage 92 establishes a fluid connection between the valve inlet 72, and in particular the main control chamber 82, and the valve outlet 74.

The main piston 76 has a particularly central recess on its face which is directed in the direction of the drive region 48, so that the main piston 76 has a hollow-cylindrical region. The recess of the master piston 76, particularly the interior of the hollow cylindrical region, preferably at least partially defines a pre-control chamber 84. On the side of the main piston 76 facing away from the main valve seat 90, a spring element 94 is mounted, which is arranged such that it exerts a spring force on the main piston 76 in the direction of the main valve seat 90. The spring element 94 is, for example, a pretensioned spring having at least one or two spring washer groups, wherein the spring washer groups are preferably configured as a disk, in particular as disk springs. The spring element 94 preferably extends over the entire diameter of the pre-control chamber 84, in particular to the inner wall of the housing part 80.

The spring element 94 preferably rests against a central block 96, which is fixedly connected to the housing part 80. The center block 96 is disposed, for example, in the pre-control chamber 84 and is supported on the housing component 80 or fixedly connected thereto. In the center block 96, a connecting channel 98 is preferably configured for connecting the pilot chamber 84 with 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. Preferably, the connecting passage 98 forms a fluid inlet that communicates into the pilot valve 70.

The pilot valve 70 comprises, for example, a slide 102, which is arranged axially movable inside the pilot working chamber 100. The end of the slide 102 facing away from the main valve 68 preferably bears against the magnetic core 62, 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 slider 102 preferably rests against the central block 96 in the closed position of the pilot valve 70 in such a way that the connecting channel 98 is completely closed by the slider 102. In the open position of the pilot valve 70, the slider 102 is lifted from the center block 96 such that the connecting passage 98 is released through the slider 102 and a fluid flow is created between the pilot control chamber 84 and the pilot working chamber 100 of the main valve 68. The pilot valve 70 preferably has a pilot housing part 104 which is arranged in a stationary manner and which, for example, rests on the housing part 80 or is fixedly connected thereto. The pilot working chamber 100 is formed inside a pilot housing part 104, the inner wall of which is formed as a preferably fluid-tight contact surface with the slide 102. The pilot housing part 104 is preferably configured as an axial guide of the slide 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 a second region 105 facing the magnetic core 62, which has a larger cross section than the first region. The second region preferably extends over the entire cross-section of pilot working chamber 100.

Fig. 3a and 3b show detailed views of the pilot valve 70, respectively. In fig. 3a, the pilot valve 70 is shown in a closed position, wherein the slider 102 completely closes the connecting channel. Preferably, the slide 102 rests in the closed position 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 slider 102 rests in the closed position of the pilot valve 70. Preferably, the slider 102 rests with its first region 103 on a first valve seat 106.

Furthermore, the pilot valve 70 preferably has a spring element 108, which is arranged in a stationary manner in the pilot valve 70 of the damping valve arrangement 54a, 54 b. The spring element 108 is, for example, a spring washer or a plurality of spring washers. The spring washer is preferably configured in a disk shape and is arranged coaxially with the slider 102. The disk-shaped spring washer is preferably connected to the pilot housing part 104, in particular fastened thereto, in a radially outer region. The radially inwardly directed region of the spring washer is preferably elastically deformable. Preferably, the spring element 108 has a central, circular cutout 110, which is arranged coaxially to the slide 102 in such a way that the magnetic core 62 can be moved axially through the cutout. The spring element 108 is clamped, for example, between the pole tube 64 and the pilot housing part 104.

The slide 102 of the pilot valve 70 preferably has at least one or more through-flow holes 112 extending through the slide 102 in the axial direction and forming a flow passage for hydraulic fluid through the slide 102. The through-flow aperture 112 extends, for example, only through the second region 105 of the slider 102, which faces the spring element 108. Preferably, the spring element 108 extends radially beyond the through-flow aperture 112, such that the spring element 108 covers said through-flow aperture in the radial direction. The slider 102 is preferably movable in the axial direction towards the spring element 108 until the slider abuts against the spring element 108. The spring element 108 extends radially beyond the through-openings 112, so that the spring element 108 covers these through-openings in the radial direction. The through-flow orifice 112 is preferably fluidly connected to the valve outlet 74, which is disposed downstream of the through-flow orifice 112.

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 maximum displacement in the axial direction, the slide 102, in particular the second valve seat 114 of the pilot valve 70, preferably rests against the spring element 108. The slider 102 is preferably only in such a position when there is no current in the winding 52 and the core 62 has a maximum displacement in the axial direction relative to the winding 52. This position is referred to in the generic term as a "fail-safe" position, in particular a fail-safe position of the pilot valve 70.

The fail-safe position of the pilot valve 70 is shown in fig. 3 b. 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 throughflow bore 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 lifts from the second valve seat 114 and the pilot valve 70 is in the open position.

In operation of the damping valve arrangement 54a, 54b, hydraulic fluid flows through the valve inlet 72 into the main control chamber 82, wherein the main piston 76 is acted upon by an opening force by the pressure in the main control chamber 82 and is moved axially upward. At this time, the main piston 76 is lifted from the main valve seat 90, and hydraulic fluid flows through the main flow passage 92 toward the valve outlet 74. At the same time, the split flow of hydraulic fluid flows through the flow bore 86 in the master piston 76 to the pre-control chamber 84 and applies a closing force to the master piston toward the master valve seat 90. By means of this closing force, 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 arrangement 54a, 54b, is determined. The pressure in the pre-control chamber 84 is regulated by the pilot valve 70, wherein hydraulic fluid flows from the pre-control chamber 84 into the pilot working chamber 100 via the connecting channel 98, which is released by the slide 102. The opening width of the connecting channel 98 is dependent on the axial position of the slide 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 pre-control chamber 84 rises 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 passage 98 is at least partially released by the slider 102 such that hydraulic flow flows through a through-flow orifice 112 in the slider 102 and to the valve outlet 74 via a flow passage arranged downstream of the through-flow orifice 112. In the currentless operation of the damping valve arrangement 54a, 54b, the position of the slide 102 of the pilot valve 70 is not preset by the winding 52, so that it is in the fail-safe position and the pilot valve 70 is in the fail-safe position. In the fail-safe position of the embodiment of fig. 3a and 3b, the through-flow aperture 112 in the slider 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 likewise moved into the closed position. If the hydraulic pressure in pilot working chamber 100 rises above the closing force of spring element 108, spring element 108 lifts from second valve seat 114 and opens through-flow bore 112.

It is also contemplated that pilot valve 70 is not in a closed position in the fail-safe position and that through-flow orifice 112 is at least partially released from spring element 108 such that main valve 68 is also in an open position. In the fail-safe position of the pilot valve, the slide 102 preferably rests against the spring element 108 in such a way that the through-flow opening 112 is closed or partially released.

Fig. 3c shows a further embodiment of a damping valve arrangement 54a, 54b, wherein this embodiment essentially corresponds to that shown in fig. 3a and 3 b. Unlike the pilot valve of fig. 3a and 3b, the pilot valve 70 of fig. 3c additionally has a pretension element 138. The prestressing element 138 is, for example, a spiral spring or a coil spring, which is arranged and constructed in particular such that it exerts a prestressing force on the slider 102 in the direction of the magnetic core 62. For example, the pretensioning element 138 bears with its end against the central block 96 and with its opposite end against the slide 102, in particular against the second region 105 of the slide 102. Preferably, the pretensioning element 138, which is configured as a spiral spring or coil spring, is arranged coaxially with the slider 102. Such a pre-tensioning element 138 increases the operational safety and ensures that the slide 102 is reliably moved in the direction of the magnetic core 62, and thus reaches a fail-safe position in the currentless operating state.

Fig. 4 shows a shock absorber 10 which essentially corresponds to the shock absorber of fig. 1, wherein a damping valve device 54c is arranged on the working piston 18. Unlike fig. 1, shock absorber 10 of fig. 4 does not have intermediate and peripheral damping valve arrangements 54a, 54b.

Fig. 5 shows a detailed view of the damping valve device 54 c. Damping valve arrangement 54c likewise comprises a drive region 48, which drive region 48 has a winding 52 and a core 62 which is axially movable therein, as described with reference to fig. 2. The damper valve arrangement 54c likewise has a valve area 50 with a main valve 68 and a pilot valve 70. For example, damping valve arrangement 54c has two main valves 68a, 68b, which are each arranged on one side of working piston 18, so that main valve 68a or 69b is active in the pull-out phase or push-in phase of shock absorber 10, respectively.

The working piston 18 has a fluid through bore 116 that opens into a main control chamber 118 of the main valve 68. The master piston 120 fluidly separates the master control chamber 118 from the pre-control chamber 122. On the working piston 18, or on a component fixedly connected thereto, a main valve seat 124 is formed, against which the main piston 120 rests in the closed position of the respective main valve 68. For example, a spring washer is disposed on the main piston 120 that directly abuts against the main valve seat 124. It is also conceivable for the main piston 120 to rest 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 prevailing in the pre-control chamber 122. For example, the pilot chambers 122 of the two main valves 68a, 68b are connected to one another by flow channels, so that preferably the same pressure exists in the pilot chambers 122 of the main valves 68a, 68 b. The pressure present in the two pre-control chambers 122 can preferably be regulated by the pilot valve 70. The pilot valve 70 has a slide 126 which is mounted so as to be axially movable and which, in the closed position of the pilot valve 70, rests against a first valve seat of the pilot valve 70. These pilot 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 slider 126, wherein the slider 126 rests against a first valve seat 128 of the pilot valve 70. The movement of the slider 126 is preferably coupled to the magnetic core 62 in at least one direction of movement and, as described with reference to fig. 1 to 3, is moved axially by the winding 52.

The main piston 120 is preferably arranged movably relative to the stationary flange region 134. In the flange region 134, flow openings 136 are formed, which connect the pre-control chamber 122 to the respective working chambers 22, 24 of the shock absorber 10. The flow openings 136 are preferably each connected to a check valve, so that hydraulic flow can only pass from the respective working chamber 22, 24 into the respective pre-control chamber 122 and not back.

When the working piston 18 moves in the pressing direction D, hydraulic fluid flows, for example, from the working chamber 24 remote from the piston rod into one of the pre-control chambers 122 via the flow opening 136 of the main valve 68b, so that the same pressure prevails in both pre-control chambers by the hydraulic connection of the pre-control chambers 122. By the position of the slide 126 relative to the first valve seat 128, the discharge of hydraulic fluid is determined by the pilot valve 70 and, in turn, the set pressure in the pre-control chamber 122. The pilot working chamber 132 of the embodiment of fig. 5 is preferably fluidically connected to an outflow channel 148, through which hydraulic fluid can flow from the pilot working chamber 132 into the first or second working chamber 22, 24.

Fig. 6a shows a detailed view of the pilot valve 70 of the damping valve arrangement 54 c. Fig. 6a shows the fail-safe position of the pilot valve 70 as described previously. The pilot valve 70 of fig. 6 substantially corresponds to the pilot valve of fig. 3. The pilot valve 70 likewise has a spring element 140, which spring element 140 comprises, for example, at least one or more spring washers. The spring element 140 is preferably configured in a disk shape, 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 with respect to the central longitudinal axis of the slide 126. As described with reference to fig. 1 to 3, the spring element 140 is arranged in a stationary manner and is fixed in a radially outer region. The pilot valve 70 of fig. 6 likewise has a second valve seat 144, which is formed on the side of the slide 126 facing the core and against which the spring element 140 can rest. Unlike fig. 3, the slider 126 of fig. 6a has a diameter smaller than the diameter of the pilot working chamber 132, such that when the pilot valve 70 is in the open position, hydraulic fluid is able to flow through the slider 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 a 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 between the slide 126 and the spring element 140 reaches the valve outlet. For example, the spring element 140 rests against 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 pilot chamber 132 rises above the opening pressure of spring element 140, the spring element lifts from second valve seat 144 and preferably cooperates with second valve seat 144 such that at least a small amount of hydraulic fluid can flow from pilot chamber 132 to valve outlet 74.

The second valve seat 114, 144 of the pilot valve 70 of the embodiment of fig. 3 or 6 has, for example, a control edge against which the spring element 140 rests. The control edge is in particular configured as an axial projection and preferably extends in the direction of the magnetic core 62. For example, the control edge is formed as a part-annular or full-circular axial projection. Preferably, the spring elements 108, 140 rest only on the control edges. Thereby preventing the spring element from sticking or sticking to the slider 126. The control edge is arranged radially inward, for example, with respect to the through-flow opening 112 in the slide 102.

The pilot working chamber 132 is fluidically separated from the outflow channel 148, for example, by means of a closing washer 150, wherein the first valve seat 128 of the pilot valve 70 is embodied, for example, in the closing washer 150 and interacts with the slide 126. The closing gasket 150 preferably has a cutout through which the slider 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 sliding blocks 126, 144 to rest thereon. The axial stop is formed, for example, by the magnetic core 62 and/or the spring elements 108, 140.

For example, a bypass channel, not shown in the figures, is formed in the slide 126, 144, in particular in the control edge, or in the spring element 108, 140, which connects the pilot working chamber with the valve outlet. Such a bypass passage is advantageous in that there may be bypass flow even when the pilot valve 70 is closed in a fail-safe position of the pilot valve, and thus a preferably slight damping is achieved.

The spring elements 108, 140 preferably have a stiffness that varies, in particular increases, as a function of the stroke. For example, the spring element 108, 140 is arranged such that in a fail-safe position of the pilot valve 70, the spring element rests against the second valve seat 114/144 in a position that is pretensioned in the direction towards the second valve seat 114/144.

Fig. 6b shows another embodiment of a pilot valve 70 of a damping valve arrangement 54 c. Unlike the pilot valve 70 of fig. 6a, the second valve seat 144 of the pilot valve 70 is constructed on a closing gasket 150. On the closing washer 150, for example, a spring element 140 is mounted, which is preferably embodied as a spring washer. In particular, the closing shim 150 has at least one or more fluid passages 152 for connecting the pilot working chamber 132 with the outflow passage 148. The spring element 140 is arranged and configured such that it at least partially or completely closes the fluid channel 152 when the hydraulic pressure inside the pilot working chamber 132 is below a certain value. If the hydraulic pressure in pilot working chamber 132 exceeds a specific pressure, in particular the opening pressure of spring element 140 in the form of a spring washer, this spring element lifts off second valve seat 144 and at least partially releases fluid channel 152.

In the currentless operating state of the pilot valve 70, the slide 126 is preferably moved by means of the hydraulic pressure in the pilot working chamber 132 or the pretensioning element 138 in the direction of the magnetic core 62, so that the slide 126 rests in a fluid-tight manner on the magnetic core and in particular on the stationary part of the pilot valve 70, so that no hydraulic fluid can flow through the slide 126 into the outflow channel 148. Spring element 140 is preferably designed such that the opening pressure is lower than the hydraulic pressure in pilot chamber 132, which is set in the current-free operation. Preferably, the opening pressure is greater than the hydraulic pressure prevailing inside the pilot working chamber 132 during normal operation, so that the spring element 140 is only opened during fail-safe operation.

Fig. 7 shows a further embodiment of a damping valve device 54c according to fig. 5, wherein only a partial view of the damping valve device 54c is shown. The damping valve device 54c differs from the damping valve device in fig. 5 by a pretensioning element 138, which is arranged and designed such that it applies a pretensioning force to the slide 126 in the direction of the magnetic core 62, according to the principle of action described with reference to fig. 3 c.

Description of the reference numerals

10 Vibration damper

12 Outer tube

14 Inner tube

16 Compensation space

18 Working piston

20 Piston rod

22 First/piston rod side working chamber

24 Second/distal working chamber to piston rod

26 Intermediate pipe

28 Annular space

30 Through holes

32 Flange area

34 Closure assembly

36 Bottom piece

38 Bottom valve

40 Adapter

42 Spring element

44 Housing upper part

45 Pipe component

46 Wiring area

48 Drive zone

50 Valve area

52 Winding

54A, 54b, 54c damper valve arrangement

56 Roof section

58 Hollow cylindrical section

60 Magnetic core chamber

62 Magnetic core

64-Pole tube

65 Magnetic core rod

66 Sealing element

68 Main valve

70 Pilot valve

72 Valve inlet

74 Valve outlet

76/120 Main piston

78 Main working chamber

80 Housing part

82/118 Main control chamber

84/122 Pre-control chamber

86/136 Flow through holes

88/134 Flange area

90/124 Main valve seat

92 Main flow channel

94 Spring element

96 Center block

98/130 Connection channel

100/132 Pilot working chamber

102/126 Slider

103 First region of the slider

104 Pilot housing part

105 Second region of the slider

First valve seat of 106/128 pilot valve 70

108/140 Spring element

110/142 Cut-outs in the spring element 108

112 Through-flow hole

Second valve seat of 114/144 pilot valve 70

116 Fluid through bore in the working piston 18

118 Main control chamber

136 Flow through holes

138 Pretensioning element

148 Outflow channel

150 Sealing gasket

152 Fluid passage

Claims (15)

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, 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 arrangement (54a, 54b, 54c) according to claim 1, characterized in that the second valve seat (114, 144) of the pilot valve (70) is configured on the slide (102; 126). 3. A damping valve device (54c) according to any of the above claims, characterized in that the pilot valve (70) has a fluid channel (152) for fluidically connecting the pilot working chamber (132) to the valve outlet, and wherein the 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 arrangement (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 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. A damping valve device (54a, 54b) according to any of the above claims, characterized in that the slider (102) of the pilot valve (70) has at least one or more flow holes (112), which extend through the slider (102) in the axial direction and constitute a flow channel for the hydraulic fluid to pass through the slider (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 arrangement (54c) according to claim 5, characterized in that the slide (126) is arranged radially offset relative to the central cutout (110; 142). 8. A damping valve device (54a, 54b, 54c) according to any of the above claims, characterized in that the second valve seat (114, 144) of the pilot valve (70) has a control edge, the spring element (108, 140) cooperates with the control edge, and wherein the control edge is constructed as an axial protrusion. 9. The damping valve arrangement (54a, 54b, 54c) according to any one of claims 6 to 8, characterized in that the control edge is arranged radially inwardly relative to the 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 is used to make the slide (126, 144) abut against it in the fail-safe position of the pilot valve (70). 11. The damping valve arrangement (54a, 54b, 54c) according to claim 10, characterized in that the axial stop is formed by the magnet core (62) and/or the spring element (108; 140). 12. A damping valve arrangement (54a, 54b, 54c) according to any of the preceding claims, characterized in that the spring element (108, 140) is arranged such that it is prestressed in the direction of the second valve seat (114; 144) in the fail-safe position of the pilot valve (70). 13. A damping valve device (54a, 54b, 54c) according to any of the above claims, characterized in that the pilot valve (70) includes a preload element (138), which is arranged and constructed in such a way that it applies a preload force to the slide (102; 126). 14. A damping valve device (54a, 54b, 54c) according to any of the above claims, characterized in that a bypass channel is constructed in the slider (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 the 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, The invention is characterized in that the shock absorber has a damping valve device (54a, 54b, 54c) according to any of the preceding claims.