WO2015055313A1

WO2015055313A1 - Vibration damper having amplitude-dependent damping

Info

Publication number: WO2015055313A1
Application number: PCT/EP2014/002789
Authority: WO
Inventors: Hanno LUCZAK; Andreas Mai; Michael Heyer
Original assignee: Thyssenkrupp Bilstein Gmbh
Priority date: 2013-10-18
Filing date: 2014-10-16
Publication date: 2015-04-23
Also published as: DE102013111502B4; DE102013111502A1

Abstract

The invention relates to a vibration damper having amplitude-dependent damping, comprising a cylindrical tube (1), which contains damping liquid, and a piston arrangement (5), which is guided on a piston rod (2) in the cylindrical tube (1). The piston arrangement has a housing (6), a comfort valve (11), and a chamber (9) having a partition element (10) being arranged in the housing (6), the partition element (10) being arranged between the comfort valve (11) and at least one opening (7a), which opens into a space (3) on the piston rod side, in the chamber (9). The piston arrangement furthermore has a sport valve (15) arranged hydraulically parallel to the comfort valve (11). According to the invention, the sport valve (15) is inserted into the housing (6), wherein a damping liquid space is formed, which is adjacent to a spring washer stack (16) of the sport valve (15) and is connected to the space (3) on the piston rod side via at least one opening (7b), wherein the sport valve (15) is designed to open an extension stage outlet (17) and a compression stage outlet (18) by means of an elastic deformation of the spring washer stack (16) depending on the pressure load.

Description

Vibration damper with amplitude-dependent damping

The invention relates to a vibration damper with amplitude-dependent damping comprising a cylinder tube with damping fluid and a guided in the cylinder bore on a piston rod and the cylinder tube in an axial direction in a piston rod side space and a piston rod remote space piston assembly comprising a housing, wherein in the housing a comfort valve and a chamber is arranged with a longitudinally movable in the chamber separating element, wherein the separating element between the comfort valve and at least one opening into the piston rod side space opening of the chamber is arranged and wherein the piston rod assembly has a hydraulically arranged parallel to the comfort valve sports valve.

In the expansion and tuning of suspension and damping a compromise between the driving comfort on the one hand and the driving safety and agility on the other hand can be found. Against this background, it is known to provide vibration dampers with different flow paths, which act hydraulically parallel to each other and allow a certain modulation of a certain modulation of the damping characteristic. To increase the comfort, it is particularly advantageous if the vibration damper has a soft characteristic in low-amplitude and high-frequency vibrations, whereas, for reasons of driving stability and safety, a harder characteristic is advantageous for large amplitudes.

In order to achieve the described properties, it is known to provide parallel flow paths for the different requirements from a hydraulic point of view, so that a different damping characteristic can be specified.

A comparatively simply constructed as well as effective vibration damper with amplitude-dependent damping is known from DE 103 51 353 B4, wherein in a housing of the piston assembly, a chamber is provided with a longitudinally movable separating piston. In low-amplitude vibrations, the separating piston in the chamber may be low

CONFIRMATION COPY Move resistance so that a soft, comfortable characteristic of the vibration damper results. The separating piston separates the chamber into two sections, one section being connected to a piston rod-side compartment and the other section being connected to a piston rod-distal compartment. Since the mobility of the separating piston is limited by the length of the chamber, the described bypass is only active for oscillations with small amplitude, because otherwise the separating piston abuts the edge of the chamber and thus blocks the bypass. The separating piston is designed with a buffer. A comparable arrangement in its function is also known from DE 10 2006 046 333 B3.

A vibration damper with the features described above is known from DE 10 2005 055 801 B3. As a development of the prior art described above, it is provided that a valve arrangement is provided between the chamber and the piston rod remote space, which is referred to in the context of the present invention, due to its function as a comfort valve. The comfort valve has a pressure relief valve for the rebound and a pressure relief valve for the pressure stage, wherein in each case a spring washer or a spring washer package is provided. This results in the advantage that the characteristic in the corresponding hydraulic path can be precisely matched to the respective requirements by means of the comfort valve.

As described above, the function of the comfort valve is limited by the arranged in the chamber separating piston to small amplitudes. For larger amplitudes of the separating piston abuts the edges of the associated chamber, so that the corresponding bypass path is blocked with the comfort valve and a hydraulically arranged in parallel valve device is active, which is also referred to as a sports valve in the invention due to their function.

The assignment of the terms comfort valve and sports valve is based on the function of the respective valve device and is essentially an easy distinction. Depending on the design of the valves but no strict functional separation before. Finally, the entire shock absorber may also be equipped with further flow paths, by-pass valves, electronically controlled valves or the like.

According to DE 10 2005 055 801 B3, the chamber with the separating piston is arranged in a housing, which constitutes an extension of the piston rod. Below the housing, ie in the direction of the piston rod remote space a subsequent to the housing hollow shaft is provided, on which the sports valve is attached.

From DE 20 2012 103 981 U1 a damping valve for a shock absorber comprising a main body and one or more valve disks is known, wherein the valve disks separate a first damping fluid chamber from a second damping fluid chamber, wherein the valve spring discs are supported via an inner and an outer edge support on the base body and controlling a passage of damping fluid in both directions by resiliently deflecting the valve spring discs from either the inner or outer edge support. In order to be able to set the force-speed behavior of the rebound stage as well as the pressure stage of a shock absorber separately, the valve disk or the valve disks are arranged on a retaining ring which is prestressed by a further spring disk package.

Based on a vibration damper with the features described above, the present invention seeks to provide an embodiment which is characterized by a compact design.

The invention relates to the sports valve is inserted into the housing, wherein an adjacent to a compression spring package of the sports valve damping fluid space is formed within the housing, which by at least one opening with the piston rod side space is connected, wherein the sports valve is adapted to by an elastic deformation of the compression spring disk package between the compression spring disk package and a first mating surface adjoining in the direction of the piston rod a Zugstufen- passage and at a pressurization of the sports valve in the opposite direction between the compression spring disk package and a subsequent in the direction of the piston rod remote space second mating surface release a Druckstufendurchlass. While according to the prior art in a generic embodiment, the sports valve or main valve is arranged on a hollow, adjacent to the housing pin, the present invention teaches in the integration of the sports valve in the housing, including a fundamentally different structural design is provided. Thus, first of all, the housing must be lengthened and designed such that sufficient space for integrating the sports valve is possible. In addition, the seal between the piston rod remote space and the piston rod side space also takes place directly on an outer periphery of the housing.

According to the invention, the sports valve furthermore has a spring disk pack which is clamped in such a way that, depending on the direction of pressurization, it releases a compression passage radially outwards and a rebound passage radially inward. Such a two-way effective spring disk package can be achieved in the invention, a particularly compact design, in a particularly advantageous manner, a central region of the sports valve in the direction of the piston rod remote space is open, so that this area as inlet and outlet channel can be used for the comfort valve.

In order to be able to influence the force-speed behavior for the pressure stage and the rebound stage separately from each other in the sports valve or main valve, the spring disk package of the sports valve can be acted upon with an additional clamping device, while then the design of the spring disk package is decisive for the compression stage takes place the opening of the Zugstufendurchlasses against the force of the spring washer package and the additional clamping device. So it is conceivable, for example, usually composed of rings spring disk package in its interior To apply area with a coil spring or the like. According to a particularly preferred embodiment, however, it is provided that the sports valve has an inner annular, radially open retaining ring and a radially outer control edge ring, wherein the retaining ring carries on its side facing the piston rod the spring disk package and on its opposite side the tensioning device. In particular, the clamping device may be formed by a tension spring package, wherein the tension spring assembly is clamped between the retaining ring and the control edge ring and wherein the control edge ring forms the second counter surface for the spring disk package of the sports valve. By using a tension spring package as a clamping device further minimization of the installation space is possible.

In order to enable a simple mounting of the sports valve, it is provided according to a preferred embodiment of the invention that the housing is open in the direction of the piston rod remote space, wherein the sports valve is inserted from the open side of the housing. The sports valve can in particular be fixed in the housing, that the control edge ring is screwed into the housing. In addition to a simple and reliable installation can optionally also be adjusted by the depth of engagement, the bias for the rebound and the rear stage of the sports valve.

The separating element is preferably a separating piston guided longitudinally movably in the housing. According to the prior art embodiments of the separating piston may have elastic stop buffer or a core of elastic material to prevent hard abutment at the edges of the housing. Additionally or alternatively, the separating piston can also be supported on both sides by springs, but in addition, other embodiments of the separating element, for example as a membrane, are possible.

For manufacturing reasons, it is advantageous if the housing is manufactured separately from the piston rod. For this purpose, the housing having a threaded bore for receiving the piston rod, in which case a simple cylindrical member may be provided as a piston rod, which is provided only at its end or at its ends with a thread.

According to a further, independent aspect of the present invention is provided starting from a generic vibration damper, that the housing is composed of an adjoining the piston rod upper housing part and a lower housing part, wherein the separating element is arranged in the upper housing part and wherein the comfort valve is inserted into the lower housing part , In the housing composed of two parts, a particularly simple and compact arrangement of the various components is possible. In particular, the upper housing part and the lower housing part can be screwed together, whereby a particularly simple connection is made possible. Particularly preferably, the housing upper part has an external thread, which is screwed into an internal thread of the housing lower part. In the context of such an embodiment, the upper housing part projects in the region of the screwing inwards over the lower housing part. It is possible to use the comfort valve in the lower housing part and then fix by screwing to the upper part in the axial direction in a positive connection. In particular, the comfort valve can be fixed between an end face of the housing upper part and an inwardly projecting collar of the housing lower part. By tightening the screw at the same time the reliable and correct position arrangement of the comfort valve, without the need for additional fasteners are required. The comfort valve may for example have a rigid base body with through openings, on each of which a spring washer package for the pressure stage and for the rebound stage is provided on both sides.

Between the collar of the housing base and the main body of the comfort valve and a further intermediate ring can be arranged, which then also forms the first mating surface for the spring disk package of the sports valve according to a particularly preferred embodiment of the invention. The invention will be explained in the following with reference to a drawing showing only one exemplary embodiment. The single FIGURE shows a section of a vibration damper according to the invention.

The vibration damper according to the invention with amplitude-dependent damping comprises a cylinder tube 1 with damping fluid and a guided in the cylinder tube 1 on a piston rod 2 and the cylinder tube 1 in an axial direction x in piston rod side space 3 and a piston rod remote space 4 piston assembly. 5

The piston assembly 5 comprises a housing 6 with an upper housing part 6a and a lower housing part 6b. Both the upper housing part 6 a and the lower housing part 6 b are provided with openings 7 a, 7 b, which open into the piston rod side space 3.

The assignment of the terms upper housing part 6a and lower housing part 6b refers to the usual orientation of a built-vibration damper in a motor vehicle, wherein the piston rod 2 is led up out of the cylinder tube 1. Of course, the vibration damper can also be mounted in a different orientation.

The piston assembly 5 is sealed at a lower end of the housing with a seal 8 against the inner wall of the cylinder tube 1, whereby the piston rod side space 3 is separated from the piston rod remote space 4.

Through the openings 7a in the upper housing part 6a on the one hand and the openings 7b in the lower housing part 6b on the other hand, two different flow paths for both the compression and the rebound are provided, which are arranged hydraulically parallel to each other to allow an amplitude-dependent damping. For this purpose, a chamber 9 is formed in the housing 6, which is bounded in the direction of the piston rod 2 and in the radial direction by the upper housing part 6a. Inside the chamber 9 a separating element 10 is arranged in the form of a separating piston, wherein in the direction of the piston rod distant space 4, a comfort valve 11 connects to the chamber 9. The comfort valve 11 comprises a main body 12 with passage openings 13a, 13b for the compression stage and rebound, wherein on both sides of the base body 12 each have a spring washer package 14a, 14b and a spring washer of the comfort valve 11 is arranged.

The space below the comfort valve 11 is open in the direction of the piston rod remote space 4.

The movement of the separating element 10 in the form of a separating piston is limited by the length of the chamber 9 in the axial direction x. If the separating piston strikes the comfort valve 11 during a pull on the piston rod 2, no further flow through the corresponding flow path is possible. The same applies if the separating piston abuts the upper housing part 6a at a pressure on the piston rod 2 at the upper edge of the chamber 9. By the described embodiment, it is possible that in vibrations with small amplitude, preferably only a weak damping effecting comfort valve 11 is active, so that these vibrations are not transmitted to the chassis of the vehicle when used in a motor vehicle.

In order to simultaneously allow a sufficiently rigid behavior of the shock absorber at greater amplitudes, based on the hydraulic separation between the piston rod side space 3 and piston rod remote space 4, a sports valve 15 and main valve arranged parallel to the chamber 9 with the separating element 10 and the comfort valve 11, wherein the openings 7b in the lower housing part 6b are associated with the sports valve 15.

According to the invention, the sports valve is inserted into the lower housing part 6b, wherein the sports valve 15 comprises a spring disk pack 16, which is formed from rings and is adapted to a rebound passage 17 by an elastic deformation between the spring disk pack 16 and a first counter surface following in the direction of the piston rod 2 and at one Pressurization of the sports valve 15 in the opposite direction between the spring disk package 16 and a subsequent in the direction of the piston rod distal space 4 second mating surface a Druckstufend urchlass 18 release. Such acting in two directions spring washer package 16 can be particularly space-saving integrated into the housing 6.

The spring disk package 16 of the sports valve 15 is received by projections of a retaining ring 19, wherein the retaining ring 19 is radially open and thus allows a pressure on the piston rod 2, a flow around the bottom of the spring disk package 16.

In the illustrated embodiment, a Spannfederscheibenpaket 20 is disposed on the retaining ring 19 opposite the spring disk package 16 which is clamped between the retaining ring 19 and a control edge ring 21, wherein the control edge ring 21 forms the second mating surface for the spring disk package 16 of the sports valve 15.

As already described above, the parallel to the sports valve 15 arranged comfort valve 11 is active for low amplitude oscillations.

Is pulled on the piston rod 2 in the axial direction x, the housing 6 moves in the cylinder tube 1 upwards. As a result, the damping fluid flows into the openings 7a of the upper housing part 6a, whereby the separating element 10 moves downward in the chamber 9, whereby the damping fluid displaced from the chamber 9 below the separating element 10 via the comfort valve 11 through the corresponding through hole 13a and the corresponding spring disk package 14a flows into the piston rod remote space 4.

In the opposite direction, ie at a pressure on the piston rod 2, results in a corresponding behavior, so that when vibrations with small amplitude, the comfort valve 11 is active. In the case of oscillations of greater amplitude, the comfort valve 11 locks in that the separating element 10 abuts as described above, so that then the sports valve 15 becomes active. In the rebound then flows the damping fluid through the openings 7b of the housing base 6b in the direction of the spring disk package 16 of the sports valve 15, wherein the spring disc package 16 against the own bias and the bias of the clamping disk package 20 in. By the pressure difference between the piston rod side space 3 and the piston rod remote 4 a radially inward area is pressed down, whereby the Zugstufendurchlass 17 is released. The damping characteristic can be adjusted in particular by the clamping disk package 20 and by the geometry of the retaining ring 19 and the control edge ring 21.

In the illustrated embodiment, the control edge ring 21 is screwed into the lower housing part 6b, so that the bias of the spring disk package 16 and the clamping screw 20 of the sports valve 15 is adjustable by the depth of engagement.

The characteristic of the sports valve 15 in the compression stage, however, is determined solely by the spring disk package 16 and its bias.

Characterized in that the housing 6 is composed of the upper housing part 6a and the lower housing part 6b, a particularly simple arrangement of the comfort valve is possible. The upper housing part 6a is screwed with an external thread into an internal thread of the lower housing part 6b, so that the upper housing part projects inwards over the inner wall of the housing lower part 6b. An end face of the upper housing part 6a presses on the main body 12 of the comfort valve 11, wherein the base body 12 is supported on the opposite side via an intermediate ring 22 on an inwardly projecting collar 23 of the lower housing part 6b. The intermediate ring 22 also forms the first mating surface for the spring disk package 16 of the sports valve 15.

Claims

claims

A vibration damper with amplitude-dependent damping comprising a cylinder tube (1) with damping fluid and a cylinder tube (1) guided on a piston rod (2) and the cylinder tube (1) in an axial direction in a piston rod side space (3) and a piston rod remote space (4) separating piston assembly with a housing (6), wherein in the housing (6) a comfort valve (11) and a chamber (9) with a in the chamber (9) movable separating element (10) are arranged, wherein the separating element ( 10) between the comfort valve and at least one in the piston rod side space (3) opening opening of the chamber (9) is arranged and wherein the piston assembly has a hydraulically arranged parallel to the comfort valve sports valve (15), characterized in that the sports valve (15) in the housing is inserted and that a damping liquid adjacent to a compression spring disk package (16) of the sports valve (15) its space is formed, which is connected by at least one opening with the piston rod side space (3), wherein the sports valve (15) is adapted, by an elastic deformation of the compression spring disk package (16) between the compression spring disk package (16) and one in the direction of the piston rod (2) subsequent to a first mating surface a Zugstufendurch- let-off (17) and between the compression spring disk package (16) and a subsequent in the direction of the piston rod remote space second mating surface release a pressure stage passage.

2. Vibration damper according to claim 1, characterized in that the comfort valve (11) has two oppositely effective flow paths for a compression stage and a rebound, each having through holes and a spring washer package (16).

3. Vibration damper according to claim 1 or 2, characterized in that the sports valve (15) has an inner annular, radially open retaining ring (19) and a radially outer control edge ring, wherein the retaining ring (19) on its the piston rod (2) facing side, the compression spring disk package (16) and carries on its opposite side a Zugfederscheibenpaket, wherein the Zugfederscheibenpaket between the retaining ring (19) and the control edge ring (21) is clamped and wherein the second mating surface of the control edge ring (21) is formed.

4. Vibration damper according to claim 3, characterized in that the housing (6) in the direction of the piston rod remote space (4) is open, wherein the sports valve (15) from the open side into the housing (6) is inserted.

5. Vibration damper according to claim 3 or 4, characterized in that the control edge ring (21) is screwed into the housing.

6. Vibration damper according to one of claims 1 to 5, characterized in that the separating element (10) in the housing (6) is longitudinally movably guided separating piston.

7. Vibration damper according to one of claims 1 to 6, characterized in that the housing (6) has a threaded bore for receiving the piston rod (2).

8. Vibration damper according to one of claims 1 to 7, characterized in that the housing (6) from a piston rod to the (2) adjoining housing upper part (6 a) and a lower housing part (6 b) is composed, wherein the separating element (10) in the Housing upper part (6a) is arranged and wherein the comfort valve (11) in the housing lower part (6b) is inserted.

9. Vibration damper according to claim 8, characterized in that the housing upper part (6 a) is screwed with an external thread in an internal thread of the housing lower part (6 b).

10. Vibration damper according to claim 8 or 9, characterized in that the comfort valve (11) is held between an end face of the upper housing part (6 a) and an inwardly projecting collar of the housing lower part (6 b) .in an axial positive fit.

11. Vibration damper according to claim 10, characterized in that between the collar (23) and a base body of the comfort valve (11) an intermediate ring (22) is arranged.

12. Vibration damper according to claim 11, characterized in that the intermediate ring (22) forms the first mating surface for the compression spring disk package (16) of the sports valve (15).