Damping valve assembly for a vibration damper, vibration damper with the damping valve assembly and method for equipping a vibration damper

Abstract

The invention relates to a damping valve assembly (4) for arrangement on an axial end of an axially movable piston rod (2) of a vibration damper (1), with a traction stage damping valve (8) which acts in the traction direction (101) of the piston rod (2), wherein the traction stage damping valve (8) has a traction stage valve body (10) and at least one traction stage valve disc (12), wherein the traction stage valve body (10) has at least one or a group of traction stage main channels (20), which are covered by the traction stage valve disc (12) in order to influence a flow through the traction stage main channels (20) during a traction movement of the piston rod (2), with a compression stage damping valve (9) which acts in the compression direction (102) of the piston rod (2), wherein the compression stage damping valve (9) has a compression stage valve body (11) and at least one compression stage valve disc (13), wherein the compression stage valve body (11) has at least one or a group of compression stage main channels (21), which are covered by the compression stage valve disc (13) in order to influence a flow through the compression stage main channels (21) during a compression movement of the piston rod (2), wherein the traction stage damping valve (8) and the compression stage damping valve (9) are each designed as a self-retaining structural unit, wherein the at least one traction stage valve disc (12) is fixed to the traction stage valve body (10) and the at least one compression stage valve disc (13) is fixed to the compression stage valve body (11).

Description

[0001] Damping valve arrangement for a vibration damper and vibration damper with the damping valve arrangement and method for equipping a vibration damper

[0002] The invention relates to a valve arrangement having the features of the preamble of claim 1. Furthermore, the invention relates to a vibration damper having the damping valve arrangement and a method for equipping a vibration damper with the damping valve arrangement.

[0003] Particularly in the automotive sector, vibration dampers are usually used in combination with a suspension in the chassis of a vehicle. Such vibration dampers are usually formed by at least one damper tube and a relatively movable piston rod, which are hydraulically damped relative to each other via a piston valve. The piston valve is located at the lower end of the piston rod and divides the interior of the damper tube into two working chambers. To adjust the damping characteristics, there are a variety of different piston valve configurations, which usually have to be assembled manually on the assembly line in series production.

[0004] The document EP 3 739234 A1 discloses a damper assembly with a housing arranged on a central axis, which defines a fluid chamber for receiving a working fluid; with a piston which is slidably arranged in the fluid chamber and divides the fluid chamber into a compression chamber and a rebound chamber; with a piston rod which is arranged on the central axis and to which the piston is attached in order to move the piston between a compression stroke and a rebound stroke; wherein the piston has a first and a second section, the first section and the second section being spaced from each other and defining a first perforation extending between the first section and the second section; with an outer sleeve having an outer surface and an inner surface which extends around the central axis between the first section and the second section and covers the first perforation;and wherein the piston has a first inlet valve and a second inlet valve disposed in the piston and coupled to the piston to prevent the working fluid from flowing into the piston, the first inlet valve being disposed adjacent to the first portion and the second inlet valve being disposed adjacent to the second portion;

[0005] The object of the invention is to create a valve arrangement of the type mentioned at the outset, which is characterized by simplified assembly and improved operating behavior.

[0006] This object is achieved according to the invention by a valve arrangement having the features of claim 1, a vibration damper having the features of claim 13 and a method having the features of claim 14. Advantageous embodiments emerge from the subclaims, the drawings and / or the description.

[0007] The subject matter of the invention is a valve arrangement which is designed and / or suitable for a vibration damper. The valve arrangement is preferably used for speed- and / or frequency-dependent damping force generation. The vibration damper has at least one damper cylinder and a piston rod which is axially movable in the damper cylinder in a tensile direction and in a compressive direction. The damping valve arrangement is designed and / or suitable for arrangement at an axial end of the piston rod, wherein the damping valve arrangement, in an assembled state, divides an interior of the damper cylinder into a rebound chamber and a compression chamber. In particular, the damping valve arrangement is motion-coupled to the piston rod, so that the damping valve arrangement is moved along with a movement of the piston rod in the tensile and compressive directions.Preferably, the rebound chamber is to be understood as a working chamber on the piston rod side and the compression chamber as a working chamber remote from the piston rod.

[0008] The damping valve arrangement has a valve that is effective in the pulling direction of the piston rod.

[0009] Rebound damping valve having a rebound valve body and at least one or more rebound valve discs for influencing the flow resistance of a rebound main volume flow. The rebound valve body has at least one or a group of rebound main channels covered by the rebound valve discs in order to influence the flow through the rebound main channels during a rebound movement of the piston rod at a base speed. In other words, the damping force during the rebound movement can be influenced and / or controlled by the at least one rebound valve disc. Preferably, the at least one rebound valve disc is designed to change and / or limit the free opening cross-section of the rebound main channels.For this purpose, the rebound main volume flow flows largely or primarily through the rebound main channels during a rebound movement of the piston rod at the base speed. Specifically, the at least one rebound valve disc covers the rebound main channels such that they are opened during the rebound movement and closed during a compression movement. In particular, the at least one rebound valve disc is formed by a spring disc. Optionally, the rebound damping valve comprises several rebound valve discs, preferably several spring discs, which are combined into a common disc package.

[0010] Furthermore, the damping valve arrangement has a pressure-stage damping valve that acts in the compression direction of the piston rod, said valve having a pressure-stage valve body and at least one or precisely one pressure-stage valve disc for influencing a flow resistance of a pressure-stage main volume flow. The pressure-stage valve body has at least one or a group of pressure-stage main channels that are covered by the pressure-stage valve disc in order to influence a flow through the pressure-stage main channels during a compression movement of the piston rod at the base speed. In other words, the damping force during the compression movement can be influenced and / or controlled by the at least one pressure-stage valve disc. Preferably, the at least one pressure-stage valve disc is designed to change and / or limit the free opening cross-section of the pressure-stage main channels.For this purpose, the pressure stage main volume flow flows largely or primarily through the pressure stage main channels during a compressive movement of the piston rod at the base speed. Specifically, the at least one pressure stage valve disc covers the pressure stage main channels such that they are opened during the compressive movement and closed during the retractive movement. In particular, the at least one pressure stage valve disc is formed by a spring disc. Optionally, the pressure stage damping valve comprises several of the pressure stage valve discs, preferably several of the spring discs, which are combined to form a common disc package.

[0011] Within the scope of the invention, it is proposed that the rebound and compression damping valves are each designed as a self-retaining structural unit.

[0012] For this purpose, at least one rebound valve disc is fixed to the rebound valve body, and at least one compression valve disc is fixed to the compression valve body. In particular, "self-retaining" is to be understood to mean that all components of the rebound or compression damping valve are held captively on the respective associated valve body in a disassembled state. In other words, all valve discs and / or tilting discs, etc., associated with the rebound or compression damping valve are fixed to the respective associated valve body. For this purpose, all components of the damping valves can preferably be pre-assembled on the respective associated valve body in an assembly process.

[0013] The invention is based on the finding that a multitude of different assembly variants exist for different damping valve arrangements, which must be assembled manually on the assembly line in series production. Due to the high number of different components and the monotonous work, assembly errors can occur, which increases the subsequent rework and the associated cycle time. Known piston valves usually consist of a rebound stage and an additional compression stage assembly, with each of these stages comprising at least three components for three different speed ranges (normal, low-frequency, and high-frequency excitation). A combination of these three speed ranges in two directional ranges each (tension and compression direction) is the reason for the large number of different assembly variants.

[0014] The advantage of the invention lies in the fact that by separating the three components of the rebound and compression stage assembly with regard to the directional ranges and, if applicable, the speed ranges, a modular design of the damping valve arrangement is enabled and, at the same time, the number of different assembly variants is significantly reduced. This significantly shortens production changeover times and thus the cycle time. By combining the damping valves into pre-assembled units, handling during assembly can be improved and assembly reliability increased. A further advantage is that, thanks to the modular design, the pre-assembled damping valves can be pre-tested before final assembly.

[0015] In a specific embodiment, it is provided that the rebound valve body has a rebound fastening section to which the at least one rebound valve disc is fixed via a rebound fastening means. Furthermore, the compression valve body has a compression fastening section to which the compression valve disc is fixed via a compression fastening means. In particular, the valve discs are at least indirectly braced against one another in the axial direction at the respectively associated fastening section between the respective fastening means and the respective valve body. The fastening section can be designed as a cylindrical, preferably hollow-cylindrical extension through which the piston rod is guided on the inside and the valve discs are mounted on the outside. In the assembled state, the two valve bodies can be supported against one another in the axial direction via the fastening sections.Particularly preferably, the fastening means is secured to the associated fastening section in a form-fitting and / or force-fitting manner in the axial direction, preferably via a screw connection. Specifically, the fastening means is mounted detachably and / or adjustably on the fastening section, so that a preload force acting on the valve disc can be adjusted by tightening or loosening the fastening means. In its simplest form, the fastening means can be designed as a screw nut. Optionally, the fastening means can have a support disc contour, which serves to support the at least one valve disc during maximum deflection or tilting.A damping valve arrangement is thus proposed which is characterized by a simple, preferably automated, assembly of the damping valves, wherein the valve discs are held in a simple manner on the valve body to form a structural unit via the fastening means.

[0016] In a further specific embodiment, it is provided that the rebound valve body has at least one or a group of rebound auxiliary channels and that the compression valve body has at least one or a group of compression auxiliary channels, wherein a pressure chamber is formed between the rebound valve body and the compression valve body, which is separated from the rebound chamber and the compression chamber and into which the rebound main channels and the rebound auxiliary channels as well as the compression main channels and the compression auxiliary channels open. The pressure chamber preferably has the function of changing a flow velocity and / or a flow direction of the main volume flow and / or of generating an additional flow resistance downstream of the respective damping valve. For this purpose, the rebound and compression valve discs are preferably arranged within the pressure chamber.In other words, the rebound valve disc covers the at least one rebound main channel and the compression valve disc covers the at least one compression main channel within the pressure chamber. The pressure chamber is preferably understood to be an annular space surrounding the main axis, which is delimited from the rebound chamber and the compression chamber. In particular, the rebound or compression main channels each lie on a first common pitch circle and the rebound or compression secondary channels each lie on a second common pitch circle, wherein the first and second pitch circles have different pitch circle diameters. The first pitch circle preferably has a smaller pitch circle diameter than the second pitch circle.Alternatively, or optionally in addition, the first pitch circle of the rebound and compression main channels each have the same pitch circle diameter, and / or the second pitch circle of the rebound and compression secondary channels each have the same pitch circle diameter. Preferably, the secondary channels extend parallel and / or in the same direction to the main channels.

[0017] The invention is further based on the realization that, in the wake of increasing noise requirements due to electrification, particularly in commercial vehicles for passenger transport, components such as shock absorbers are increasingly becoming the focus of noise optimization. The basic design of hydraulic dampers converts kinetic energy into heat through shearing, which can result in flow noise depending on the characteristics of the damper characteristic. By enclosing the damping valves, noises caused by pressure differences inside the pressure chamber can be reduced before they are emitted outward toward the damper cylinder.

[0018] In a further specific implementation, it is provided that the rebound valve body has a rebound piston skirt section and the compression valve body has a compression piston skirt section, wherein the rebound and compression piston skirt sections engage with each other in a form-fitting manner at least in the radial direction. In particular, the two valve bodies are axially guided via the piston skirt sections within the damper cylinder. Preferably, the rebound and compression piston skirt sections each have a seal receptacle on the outer circumference, which is each designed and / or suitable for receiving a sealing ring, in particular a piston sealing ring. In particular, the piston skirt sections each extend in the axial direction in the same direction as the respectively associated fastening section.Particularly preferably, one piston skirt section has a positive-locking contour and the other piston skirt section has a complementary mating contour, via which the two piston skirt sections engage with each other in a positive-locking manner. For example, the positive-locking contour and the mating contour can be formed by two annular shoulders that are complementary to one another. Thus, a damping valve arrangement is proposed that is characterized by simple assembly and a particularly robust design. The positive locking between the two valve bodies ensures a particularly stable connection between the two valve bodies when mounted on the piston rod.

[0019] In a further specification, it is provided that the pressure chamber is radially delimited by the rebound and compression stage piston skirt sections. In particular, the pressure chamber is completely delimited from the damper cylinder by the two intermeshing piston skirt sections. For this purpose, the piston skirt sections are preferably supported on one another in a form-fitting manner in the axial direction and / or arranged to overlap one another. It is particularly preferably provided that a joint formed between the two piston skirt sections is arranged in the axial direction between the sealing rings. The pressure chamber can thus be delimited in a radial direction by the two piston skirt sections relative to the damper cylinder.In an installation situation, the two engaged piston skirt sections prevent the main volume flow escaping after the damping valves from directly impacting the cylinder wall of the damper cylinder, thereby achieving further noise reduction.

[0020] In a further development, it is provided that the rebound and compression damping valves are and / or can be connected to one another via the rebound and compression piston skirt sections to form a common, in particular self-retaining, structural unit. In particular, the two valve bodies can be connected to one another via the two piston skirt sections in an axial direction in a form-fitting and / or force-fitting manner, for example via a press fit, in order to connect the two damping valves to one another. Thus, the two damping valves can be easily connected to one another before mounting on the piston rod, so that they can be pre-assembled and handled as a single unit.

[0021] In a further embodiment, the damping valve arrangement comprises a rebound throttle plate acting in the pulling direction of the piston rod, covering the main rebound channels within the rebound chamber and having one or more rebound throttle openings to throttle flow through the main rebound channels during a pulling movement of the piston rod at a speed increased relative to the base speed. Furthermore, the damping valve arrangement comprises a compression throttle plate acting in the pushing direction of the piston rod, covering the main compression channels within the compression chamber and having one or more compression throttle openings to throttle flow through the main compression channels during a pushing movement of the piston rod at the increased speed.In particular, the throttle plates serve to adjust the damping force during high-frequency excitation of the vibration damper, whereby the damping force can be influenced by the number and / or dimensioning of the throttle opening. For example, a high-frequency excitation corresponds to a frequency of more than 2 Hz, preferably more than 10 Hz, especially more than 20 Hz. In principle, the rebound and compression throttle plates are identical in construction and / or interchangeable. For example, the rebound and / or compression throttle plates can be replaced by different throttle plates of a throttle plate set, whereby the throttle plates are designed differently with regard to the number and / or dimensioning of the throttle openings. The rebound throttle plate is preferably arranged or clamped in the axial direction between the rebound valve body and the piston rod.The compression throttle plate is preferably arranged or clamped axially between the compression valve body and the piston rod, in particular a retaining element mounted on the piston rod. Thus, a damping valve arrangement is proposed that is characterized by enhanced modularity and thus by a customized design of the damping characteristics. Furthermore, it is possible to select the rebound and compression throttle plates independently of each other. Alternatively, the throttle plate can also be designed so that the main channels are only partially covered.

[0022] In a further embodiment, the damping valve arrangement comprises a rebound cover plate which covers the rebound auxiliary channels within the rebound chamber in order to prevent or restrict the flow of the rebound main volume flow through the rebound auxiliary channels during the rebound movement. Furthermore, the damping valve arrangement comprises a compression cover plate which covers the compression auxiliary channels within the compression chamber in order to prevent or restrict the flow of the compression main volume flow through the compression auxiliary channels during the compression movement. In particular, the cover plates prevent an unwanted and / or uncontrolled inflow of damper fluid into the compression chamber via the auxiliary channels. More precisely, the rebound cover plate prevents flow through the rebound auxiliary channels during the rebound movement and allows flow through the rebound auxiliary channels during the compression movement.The same applies to the compression cover plate in reverse order. The rebound cover plate is preferably arranged or clamped in the axial direction between the rebound valve body, in particular the rebound throttle plate, and the piston rod. The compression cover plate is arranged or clamped in the axial direction between the compression valve body, in particular the compression throttle plate, and the piston rod, in particular the securing means. The cover plates are preferably designed to have low opening resistance in order to ensure the chambering of the pressure chamber.

[0023] The opening resistance creates additional internal pressure in the pressure chamber, which ensures that the fluid pressure drops to an intermediate pressure after passing through the respective damping valve. This intermediate pressure is higher than the fluid pressure of the downstream rebound or compression chamber. The multi-stage pressure reduction thus proposes a damping valve arrangement whose flow noise is significantly reduced at all damper speeds.

[0024] In a further specification, it is provided that the rebound cover plate has and / or helps form at least one or exactly one rebound flow opening in order to enable a constant flow through the rebound auxiliary channels during a rebound movement of the piston rod at a speed reduced to the basic speed. Furthermore, it is provided that the compression cover plate has and / or helps form at least one or exactly one compression flow opening in order to enable a constant flow through the compression auxiliary channels during a compressive movement of the piston rod at a speed reduced to the basic speed. In particular, the cover plates thus also serve to adjust the damping force during low-frequency excitation of the vibration damper, wherein the damping force can be influenced by the number and / or dimensioning of the flow openings.For example, a low-frequency excitation corresponds to a frequency of less than 2 Hz, preferably less than 0.5 Hz, and especially less than 0.1 Hz. In principle, the rebound and compression cover plates are identical in design and / or interchangeable. For example, the rebound and / or compression cover plates can be replaced with different cover plates from a cover plate set, whereby the cover plates are designed differently with regard to opening resistance and / or the number and / or dimensioning of the flow openings. Preferably, the two damping valves, the two throttle plates, and the two cover plates can be combined with one another as desired. This makes it possible to specify a number of rebound and compression stages that are sensibly graduated.

[0025] In a first possible embodiment, the rebound and / or compression stage cover plates are each designed as a pre-opening plate, with the flow opening being formed by at least one pre-opening formed in the cover plate. For example, the pre-opening can be formed by a radial opening, cutout, bore, indentation, or the like in the cover plate. By designing the cover plates as pre-opening plates, a defined selection of different cover plates from an existing valve kit can be used.

[0026] In an alternative or optionally supplementary development, it is provided that the rebound and / or compression valve body has a circumferential valve seat surface for the cover plate, wherein the flow opening is formed by at least one or precisely one recess in the valve seat surface. For example, the recess can be formed by a groove, notch, cutout, bore, or the like in the valve seat surface. Due to the arrangement of the recess in the valve seat surface of the respective valve body, this has no influence on the disc thickness of the cover plates and thus on the damping characteristics.In a specific implementation, the main rebound volume flow during the rebound movement runs from the rebound chamber via the rebound damping valve into the compression chamber and from the compression chamber via the compression auxiliary channel into the compression chamber, with the flow rate of the main rebound volume flow from the compression chamber to the compression chamber being limited or controlled by the rebound throttle plate. Accordingly, the main compression volume flow during the compression movement runs from the compression chamber via the compression damping valve into the compression chamber and from the pressure chamber via the rebound auxiliary channel into the rebound chamber, with the flow rate of the main compression volume flow from the pressure chamber to the rebound chamber being limited or controlled by the compression throttle plate.Optionally, the main rebound flow can flow at least partially or completely through the rebound flow opening into the compression chamber during a rebound movement at reduced speed, or the main compression flow can flow at least partially or completely through the compression flow opening into the compression chamber during a compression movement at reduced speed. In other words, flow openings serve to bypass the rebound or compression valve disc at low vibration damper speeds. In particular, the flow openings can ensure a constant flow from the rebound or compression chamber into the compression chamber, which allows the vibration damper to be wound up manually.

[0027] A further subject matter of the invention relates to a vibration damper with the valve arrangement as already described above or according to one of claims 1 to 12. The vibration damper is preferably designed and / or suitable for damping vibrations. The vibration damper can be designed, for example, as a hydraulic damper. In particular, the vibration damper can be designed and / or suitable for a chassis of a vehicle. Preferably, the vehicle is designed as a commercial vehicle, specifically for passenger transport, such as a bus. A further subject matter of the invention relates to a method for equipping a vibration damper with the valve arrangement as already described above or according to one of claims 1 to 12, in which:

[0028] - the rebound damping valve is pre-assembled by fixing at least one rebound valve disc to the rebound valve body;

[0029] - the compression damping valve is pre-assembled by fixing at least one compression valve disc to the compression valve body;

[0030] - the pre-assembled rebound valve and the pre-assembled compression damping valve are mounted on the axial end of the piston rod.

[0031] In particular, the rebound and compression damping valves can be pre-assembled separately, preferably automatically. This reduces the cycle time for assembling the vibration damper in series production. Furthermore, it is possible to purchase and / or store the damping valves pre-assembled. The throttle plates and / or cover plates can be pre-positioned on the respective valve body during the subsequent assembly process or mounted directly on the piston rod. The throttle plates and / or cover plates can be selected independently of one another in the rebound and compression directions from the corresponding modular system, allowing the vibration damper to be tuned in the low and high speed ranges, as well as in the rebound and compression directions.

[0032] In a further intermediate step, the pre-assembled rebound damping valve and the pre-assembled compression damping valve can be connected to form a single unit before installation on the piston rod. To this end, the two damping valves are connected to each other via the two piston skirt sections, preferably with a force fit. The two damping valves can then be mounted together as a single unit on the piston rod. This further simplifies the assembly process.

[0033] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. Figure 1 shows a sectional view of a vibration damper as an embodiment of the invention;

[0034] Fig. 2 is an exploded view of a damping valve arrangement for the vibration damper according to Fig. 1;

[0035] Fig. 3 is a perspective view of the damping valve arrangement in an alternative embodiment;

[0036] Fig. 4 is a sectional view of the damping valve arrangement according to Fig. 3;

[0037] Fig. 5 is a perspective view of a damping valve of the damping valve arrangement in a further alternative embodiment;

[0038] Fig. 6 is a sectional view of the damping valve arrangement according to Fig. 5;

[0039] Fig. 7 is a perspective view of a damping valve of the damping valve arrangement.

[0040] Figure 1 shows a sectional view of a vibration damper 1, which is designed and / or suitable, for example, for a vehicle. The vibration damper 1 has a piston rod 2 and at least one damper cylinder 3, wherein the piston rod 2 is arranged in the damper cylinder 3 so as to be movable along a main axis 100 in a tensile direction 101 and a compressive direction 102.

[0041] For example, during a vehicle compression process, the piston rod 2 undergoes a compressive movement in the compressive direction 102, whereby the vibration damper 1 is compressed. During a vehicle rebound process, the piston rod 2 undergoes a tensile movement in the tensile direction 101, whereby the vibration damper 1 is pulled apart.

[0042] The vibration damper 1 has a damping valve arrangement 4, which is mounted at the end of a support section 5 of the piston rod 2 and divides an interior of the damper cylinder 3 in the axial direction with respect to the main axis 100 into a rebound chamber 6 and a compression chamber 7. The damping valve arrangement 4 is motion-coupled to the piston rod 2 via the support section 5 and is thus displaceable within the damper cylinder 3 in the rebound direction 101 or in the compression direction 102 upon movement of the piston rod 2.

[0043] The damping valve arrangement 4 has a rebound damping valve 8 effective during the rebound movement and a compression damping valve 9 effective during the compression movement. The rebound and compression chambers 6, 7 are hydraulically connected to one another via the two damping valves 8, 9, with the rebound damping valve 8 delimiting the rebound chamber 6 and the compression damping valve 9 delimiting the compression chamber 7.

[0044] The two damping valves 8, 9 each have a valve body 10, 11 and a plurality of valve discs 12, 13 attached to the respective valve body 10, 11. For this purpose, the two valve bodies 10, 11 each have a fastening section 14, 15, to which the respective valve discs 12, 13 are held via a respective fastening means 16, 17. For example, the valve discs 12, 13 are each designed as spring washers, which are combined to form a spring washer package. A tilting disc 18, 19 is arranged between the fastening means 16, 17 and the valve discs 12, 13 in order to enable the valve discs 12, 13 to tilt when pressure is applied.The rebound and compression damping valves 8, 9 are each designed as a self-retaining structural unit, wherein the valve discs 12, 13 and the tilting disc 18, 19 are each held captively by the associated fastening means 16, 17 on the respective fastening section 14, 15 in a removed state of the damping valves 8, 9 and are pre-tensioned if necessary.

[0045] The rebound valve body 10 has a plurality of rebound main channels 20 and a plurality of rebound sub-channels 22, and the compression valve body 11 has a plurality of compression main channels 21 and a plurality of compression sub-channels 23, all of which open into a common pressure chamber 24. The pressure chamber 24 is formed between the two valve bodies 10, 11 and is separated from the rebound and compression chambers 6, 7. The rebound main channels 20 are covered within the pressure chamber 24 by the rebound valve discs 12 in the rebound direction 101, and the compression main channels 21 are covered within the pressure chamber 24 by the compression valve discs 13 in the rebound direction 102.

[0046] The two valve bodies 10, 11 each have a piston skirt section 25, 26, which are positively connected to one another at least in the radial direction with respect to the main axis 100. The two piston skirt sections 25, 26 engage with one another in such a way that the pressure chamber 24 is completely bounded in the radial direction by the two piston skirt sections 25, 26. For example, the rebound piston skirt section 25 has an annular shoulder on the inner circumference, and the compression piston skirt section 26 has a complementary annular shoulder on the outer circumference, via which the two piston skirt sections 25, 26 are positively engaged with one another. Furthermore, the fastening sections 14, 15 of the two damping valves 8, 9 are supported on one another in the axial direction with respect to the main axis 100 in such a way that the pressure chamber 24 is completely delimited in the radially opposite direction by the two fastening sections 14, 15.In other words, the pressure chamber 24 is chambered off from the rebound and compression chambers 6, 7.

[0047] The two piston skirt sections 25, 26 each have a seal receptacle 27, 28, in which a respective sealing ring 29, 30 is arranged. The two seal receptacles 27, 28 are arranged spaced apart from one another in the axial direction, with a joint formed between the two piston skirt sections 25, 24 being arranged between the two seal receptacles 27, 28 and the two sealing rings 29, 30.

[0048] The damping valve arrangement 4 further comprises a rebound and a compression throttle plate 31, 32, wherein the rebound throttle plate 31 is arranged in the rebound chamber 6 and the compression throttle plate 32 is arranged in the compression chamber 7. The rebound throttle plate 31 covers the rebound main channels 20 on an opposite side of the rebound valve plates 12, and the compression throttle plate 32 covers the compression main channels 21 on an opposite side of the compression valve plates 13. The two throttle plates 31, 32 each have one or more throttle openings 33, 34, via which a throttling ("hole damping") of a flow through the main channels 20, 21 is generated upon high-frequency excitation of the vibration damper 1.The smaller the number and / or the smaller the opening diameter of the throttle openings 33, 34, the higher the “hole damping” and thus the damping forces at high speeds of the piston rod 2 relative to the damper cylinder 3.

[0049] Furthermore, the damping valve arrangement 4 has a rebound stage and a compression stage cover plate 35, 36, wherein the rebound stage cover plate 35 is arranged in the rebound stage chamber 6 and the compression stage cover plate 36 is arranged in the compression stage chamber 7. The rebound stage cover plate 35 covers the rebound stage secondary channels 22 in such a way that, during the rebound movement, a flow from the rebound stage chamber 6 into the compression chamber 24 via the rebound stage secondary channels 22 is prevented or significantly reduced, and during the compression movement, a flow from the compression chamber 24 into the rebound stage chamber 6 is released. Accordingly, the compression stage cover plate 36 covers the compression stage secondary channels 23 in such a way that during the compression movement, a flow from the compression stage chamber 7 into the pressure chamber 24 via the compression stage secondary channels 23 is prevented or significantly reduced, and during the tension movement, a flow from the pressure chamber 24 into the compression stage chamber 7 is released.

[0050] The two damping valves 8, 9, the two throttle discs 31, 32 and the two cover discs 35, 36 are arranged coaxially with respect to the main axis 100 on the support section 5 and are secured by a securing means 37 or clamped to the piston rod 2.

[0051] In a properly assembled state, the damper cylinder 3 is filled with a damper fluid, e.g., oil. During a pulling movement of the piston rod 2 in the pulling direction 101, a rebound main volume flow I thus flows from the rebound chamber 6 via the rebound throttle plate 31 and the rebound damping valve 8 into the compression chamber 24, and from the pressure chamber 24 via the compression cover plate 36 into the compression chamber 7. During a pushing movement of the piston rod 2 in the pushing direction 102, a compression main volume flow II flows from the compression chamber 7 via the compression throttle plate 32 and the compression damping valve 9 into the pressure chamber 24, and from the pressure chamber 24 via the rebound cover plate 35 into the rebound chamber 6.

[0052] The valve discs 12, 13 of the damping valves 8, 9 serve to influence, in particular to throttle, the respective main volume flow I, II during normal excitation or at an average speed of the piston rod 2. The cover discs 35, 36 are designed such that they have a slight opening resistance in order to ensure the chambering of the pressure chamber 24. During the retraction movement, the compression stage cover disc 36 tilts and thus allows the rebound stage main volume flow I to flow from the pressure chamber 24 into the compression stage chamber 7. During the compression movement, however, the rebound stage cover disc 35 tilts and thus allows the compression stage main volume flow II to flow from the pressure chamber 24 into the rebound stage chamber 6.The opening resistance creates a fluid pressure in the pressure chamber 24, which ensures that the fluid pressure is highest before passing through the damping valves 8, 9, reaches an intermediate level in the pressure chamber 24, and can only drop further after the corresponding cover plate 35, 36 opens. This multi-stage pressure reduction leads to a reduction in the noise of the damping valve assembly 4.

[0053] Furthermore, the two cover disks 35, 36 prevent any undesired inflow of damper fluid into the pressure chamber 24 via the secondary channels 22, 23 if no pre-opening is desired or present. In the event of high-frequency excitation or an increasing speed of the piston rod 2, the main volume flows I, II are increasingly influenced or throttled by the respective throttle disk 31, 32. Figure 2 shows the damping valve arrangement 4 in an exploded view. During an assembly process, the two damping valves 8, 9 are automatically pre-assembled separately from one another. For this purpose, the valve disks 12, 13 and the tilting disks 18, 19 are mounted on the fastening section 14, 15 and then secured by the respective fastening means 16, 17 or clamped against the associated valve body 10, 11.The two damping valves 8, 9 can be combined with each other as desired, allowing a small number of rebound and compression stages to be defined, which are sensibly graduated (damping force level). Since the same damping forces can be achieved with different configurations, the valve configuration of the two damping valves 8, 9 with the smallest damping force dispersion can be selected. Furthermore, pre-assembling the two damping valves 8, 9 can reduce the cycle times for assembling the vibration damper 1 in series production.

[0054] In the further assembly process, the throttle discs 31, 32 and the cover discs 35, 36 can be selected from a valve kit according to the desired damping characteristics. The throttle discs 31, 32 and the cover discs 35, 36 can be pre-positioned on the respective valve body 10, 11 before assembly on the support section 5. Alternatively, however, the cover discs 35, 36, the throttle discs 31, 32, and the damping valves 8, 9 can be pushed onto the support section 5 one after the other, as shown in Figure 2, and then secured against loss by the securing means 37.

[0055] Alternatively, however, it can also be provided that the two damping valves 8, 9 are joined to form a common unit via the piston skirt sections 25, 26 prior to assembly. For this purpose, the compression piston skirt section 26 can be arranged within the rebound piston skirt section 25 in a force-locking manner, e.g., via a press fit.

[0056] As can be seen from Figures 3 and 4, the two cover plates 35, 36 each have two diametrically opposed flow openings 38, 39, which enable a constant flow from the rebound chamber 6 or the compression chamber 7 into the pressure chamber 24 during low-frequency excitation of the vibration damper 1. In other words, the rebound main volume flow I, not shown, runs exclusively or largely from the rebound chamber 6 via the rebound flow openings 38 and the rebound secondary channels 22 into the pressure chamber 24 during low-frequency excitation or when the piston rod 2 has a low speed in the rebound direction 101. Accordingly, the compression main volume flow II, not shown, runs exclusively or largely from the rebound chamber 6 via the rebound flow openings 38 and the rebound secondary channels 22 into the pressure chamber 24 during low-frequency excitation or when the piston rod 2 has a low speed in the rebound direction 101.at a low speed of the piston rod 2 in the pressure direction 102 exclusively or largely from the pressure stage chamber 7 via the pressure stage flow openings 39 and the pressure stage secondary channels 23 into the pressure chamber 24. The cover disks 35, 36 are each designed as pre-opening disks, wherein the two cover disks 35, 36 each have two diametrically opposed pre-openings, for example radially introduced cutouts, to form the flow openings.

[0057] Furthermore, Figure 3 shows that the cover disks 35, 36 are each secured between the respective valve body 10, 11 and the piston rod 2 or the securing means 37 via one or more spring sections 40. The spring sections 40 apply the opening resistance to the cover disks 35, 36, allowing them to spring upwards from the respective valve body 10, 11 to allow flow from the pressure chamber 24 through the respective secondary channel 22, 23.

[0058] As can be seen from Figures 5 and 6, the flow openings 38, 39 are each provided in a circumferential valve seat surface 41 of the respective valve body 10, 11 instead of in the cover disks 35, 36. For this purpose, the flow openings 38, 39 are each formed by one or more recesses, for example radially introduced grooves, made in the valve seat surface 41. In an assembled state, the cover disks 35, 36 rest against the respective associated valve seat surface 41, so that the flow openings 38, 39 are delimited or co-formed by the cover disks 35, 36. Figure 7 shows one of the damping valves 8, 9 in a perspective view from below with the mounted fastening means 16, 17. The fastening means 16, 17 is designed as a screw nut which can be screwed onto an external thread arranged on the fastening section 14, 15.The fastening means 16, 17 each have an integrated support disk contour 42, which serves to support the respective associated valve disks 12, 13 at maximum deflection, i.e. at high-frequency excitation or at high speeds of the piston rod 2.

[0059] In general, the at least one rebound main channel 20, compression main channel 21, rebound secondary channel 22, and compression secondary channel 23 can be designed such that it opens into a circumferential annular groove at its at least one axial end section, which in this case can be covered by a corresponding respective rebound valve disc 12 and / or a corresponding respective compression valve disc 13.

[0060] It should also be mentioned that the valve assembly of the compression damping valve 9 is arranged in a mirror image to the valve assembly of the rebound damping valve 8, whereby the two damping valves 8, 9 can thus be designed essentially identically. This also allows the incoming compression stage main volume flow II, as described in Figure 1, to be optimized in its flow direction. This results in a further reduction in noise during the compression stage. Furthermore, it is no longer necessary - as was previously the case - to design the pitch circle of the compression stage main channels 21 to be larger than the pitch circle of the rebound stage main channels 20 in order to be able to continue to manufacture the valve bodies 10, 11 using sintering technology.

[0061] Reference symbol

[0062] Vibration damper Piston rod Damper cylinder Damping valve arrangement Support section Rebound chamber Compression chamber

[0063] Rebound damping valve Compression damping valve

[0064] Rebound valve body

[0065] Compression valve body Rebound valve disc

[0066] compression valve disc

[0067] Rebound mounting section Compression mounting section Rebound mounting means Compression mounting means Rebound tilting discs Compression tilting discs Rebound main channels Compression main channels Rebound sub-channels

[0068] Pressure stage side channels pressure chamber

[0069] Rebound piston skirt section Compression piston skirt section Rebound seal retainer Compression seal retainer Rebound seal ring Compression seal ring Rebound throttle plate Compression throttle plate

[0070] Rebound throttle openings Compression throttle openings Rebound cover plate Compression cover plate

[0071] Security measures

[0072] Rebound flow ports

[0073] Pressure stage flow openings

[0074] Spring sections

[0075] Valve seat surface

[0076] Support disc contour

[0077] Main axis

[0078] Direction of pull

[0079] Print direction

[0080] Rebound main volume flow

[0081] Pressure stage main volume flow

Claims

Patent claims 1 . Damping valve arrangement (4) for arrangement at an axial end of a piston rod (2) of a vibration damper (1) which is axially movable in a damper cylinder (3) in a tensile direction (101) and in a compression direction (102), wherein the damping valve arrangement (4) in an assembled state divides an interior of the damper cylinder (3) into a rebound chamber (6) and a compression chamber (7), with a rebound damping valve (8) acting in the tensile direction (101) of the piston rod (2), wherein the rebound damping valve (8) has a rebound valve body (10) and at least one rebound valve disc (12), wherein the rebound valve body (10) has at least one or a group of rebound main channels (20) which are covered by the rebound valve disc (12) in order to ensure a flow through to influence the rebound main channels (20) during a pulling movement of the piston rod (2) at a basic speed,with a pressure stage damping valve effective in the pressure direction (102) of the piston rod (2)! (9), wherein the compression damping valve (9) has a compression valve body (11) and at least one compression valve disc (13), wherein the compression valve body (11) has at least one or a group of compression main channels (21) which are covered by the compression valve disc (13) in order to influence a flow through the compression main channels (21) during a compression movement of the piston rod (2) at the basic speed, characterized in that the rebound damping valve (8) and the compression damping valve (9) are each designed as a self-retaining unit, wherein the at least one rebound valve disc (12) is fixed to the rebound valve body (10) and the at least one compression valve disc (13) is fixed to the compression valve body (11).

2. Damping valve arrangement (4) according to claim 1, characterized in that the at least one rebound valve disc (12) is fixed via a rebound fastening means (16) to a rebound fastening section (14) formed on the rebound valve body (10); and in that the at least one compression valve disc (13) is fixed via a compression fastening means (17) to a compression fastening section (15) formed on the compression valve body (11).

3. Damping valve arrangement (4) according to claim 1 or 2, characterized in that the rebound valve body (10) has at least one or a group of rebound secondary channels (22) and that the compression valve body (11) has at least one or a group of compression secondary channels (23), wherein between the rebound valve body (10) and the compression valve body (11) a pressure chamber (24) is formed which is separated from the rebound chamber (6) and the compression chamber (7), into which pressure chamber the rebound main channels (20) and the rebound secondary channels (22) as well as the compression main channels (21) and the compression secondary channels (23) open.

4. Damping valve arrangement (4) according to one of the preceding claims, characterized in that the rebound valve body (10) has a rebound piston skirt section (25) and the compression valve body (11) has a compression piston skirt section (26), wherein the rebound and compression piston skirt sections (25, 26) are in positive engagement with one another at least in the radial direction.

5. Damping valve arrangement (4) according to claim 4, characterized in that the pressure chamber (24) is radially delimited by the rebound stage and the compression stage piston skirt section (25, 26).

6. Damping valve arrangement (4) according to claim 4 or 5, characterized in that the rebound and compression damping valves (8, 9) are connected to one another via the rebound and compression piston skirt sections (25, 26) to form a common structural unit.

7. Damping valve arrangement (4) according to one of the preceding claims, characterized by a rebound throttle disc (31) acting in the pulling direction (101) of the piston rod (2), which covers the rebound main channels (20) within the rebound chamber (6) and has at least one or more rebound throttle openings (33) in order to prevent a flow through the rebound main channels (20) during a pulling movement of the piston rod (2) at a speed which is higher than the basic speed increased speed; and a pressure stage throttle disc (32) acting in the pressure direction (102) of the piston rod (2), which covers the pressure stage main channels (21) within the pressure stage chamber (7) and has at least one or more pressure stage throttle openings (34) in order to throttle a flow through the pressure stage main channels (21) during a pressure movement of the piston rod (2) at the speed increased to the basic speed.

8. Damping valve arrangement (4) according to one of claims 3 to 7, characterized by a rebound cover plate (35) which covers the rebound auxiliary channels (22) within the rebound chamber (6) in order to prevent or throttle a flow of a rebound main volume flow (I) through the rebound auxiliary channels (22) during the rebound movement; and a compression cover plate (36) which covers the compression auxiliary channels (23) within the compression chamber (7) in order to prevent or throttle a flow of a compression main volume flow (II) through the compression auxiliary channels (23) during the compression movement.

9. Damping valve arrangement (4) according to claim 8, characterized in that the rebound stage cover plate (35) has and / or co-forms at least one rebound stage flow opening (38) in order to enable a constant flow through the rebound stage auxiliary channels (22) during a rebound movement of the piston rod (2) at a speed reduced to the basic speed; and the compression stage cover plate (36) has and / or co-forms at least one compression stage flow opening (39) in order to enable a constant flow through the compression stage auxiliary channels (23) during a compression movement of the piston rod (2) at the speed reduced to the basic speed.

10. Damping valve arrangement (4) according to claim 9, characterized in that the rebound stage and / or compression stage cover disc (35, 36) is designed as a pre-opening disc, wherein the flow opening (38, 39) is formed by at least one pre-opening introduced into the cover discs (35, 36).

11. Damping valve arrangement (4) according to claim 9 or 10, characterized in that the rebound stage and / or compression stage valve body (10, 11) have a circumferential valve seat surface (41) for the cover discs (35, 36), wherein the flow opening (38, 39) is formed by at least one recess introduced into the valve seat surfaces (41).

12. Damping valve arrangement (4) according to one of claims 8 to 11, characterized in that the rebound stage main volume flow (I) during the rebound movement runs from the rebound stage chamber (6) via the rebound stage damping valve (8) into the pressure chamber (24) and from the pressure chamber (24) via the pressure stage secondary channel (23) into the compression stage chamber (7), wherein the flow rate of the rebound stage main volume flow (I) from the pressure chamber (24) into the compression stage chamber (7) is limited by the rebound stage throttle plate (31); and that the compression stage main volume flow (II) during the pressure movement runs from the compression stage chamber (7) via the compression stage damping valve (9) into the pressure chamber (24) and from the pressure chamber (24) via the rebound stage secondary channel (22) into the rebound stage chamber (6), wherein the flow rate of the compression stage main volume flow (II) from the pressure chamber (24) into the rebound stage chamber (6) is limited by the compression stage throttle plate (32).

13. Vibration damper (1) with the damping valve arrangement (4) according to one of the preceding claims.

14. A method for equipping a vibration damper (1) with the damping valve arrangement (4) according to one of claims 1 to 12, in which: - the rebound damping valve (8) is pre-assembled by fixing the rebound valve disc (12) to the rebound valve body (10); - the compression damping valve (9) is pre-assembled by fixing the compression valve disc (13) to the compression valve body (11); - the pre-assembled rebound damping valve (8) and the pre-assembled compression damping valve (9) are mounted on one axial end of a piston rod (2).

15. Method according to claim 14, characterized in that the rebound damping valve and the compression damping valve (8, 9) are connected to one another to form a common structural unit before assembly on the piston rod (2).

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