WO2016151015A1

WO2016151015A1 - Vibration damper having a reduced structural length

Info

Publication number: WO2016151015A1
Application number: PCT/EP2016/056380
Authority: WO
Inventors: Daniel ADAEV; Andreas Lehnen; Joachim Frey
Original assignee: Thyssenkrupp Bilstein Gmbh; Thyssenkrupp Ag
Priority date: 2015-03-25
Filing date: 2016-03-23
Publication date: 2016-09-29
Also published as: DE102015104494A1

Abstract

The invention relates to an oil-filled vibration damper (1) comprising a damper tube (10) in which a damper piston (11) is guided along a vibration damper (1) longitudinal axis (12) in a reciprocally-movable manner, separating a first working chamber (A) from a second working chamber (B) within said damper tube (10) and comprising a piston rod (13) that is connected to said damper piston (11) and fed out of said damper tube (10) in a sealed manner, a gas-filled equaliser chamber (14) being provided which is separated from the second working chamber (B) by means of a dividing piston (15). According to the invention, the equaliser chamber (14) is designed in a guide tube (17) that extends along a tube longitudinal axis (16), said dividing piston (15) being guided within said guide tube (17) along the tube longitudinal axis (16) in a reciprocally-movable manner, and said tube longitudinal axis (16) being aligned perpendicularly to the longitudinal axis (12) of the damper tube (10).

Description

Vibration damper with shortened overall length B e s c o rp e c tio n

The present invention relates to a vibration damper with an oil-filled damper tube, in which a damper piston is guided in a liftable manner in a longitudinal axis of the vibration damper and a first working space separates from a second working space in the damper tube. The vibration damper further comprises a piston rod which is connected to the damper piston and is led out of the damper tube sealed. Also provided is a compensating space filled with a gas, which is separated from the second working space by means of a separating piston.

STATE OF THE ART

DE 43 10 341 Cl shows a vibration damper of a type of interest here, and the compensation chamber is arranged in the longitudinal axis direction below the second working space and separated by the separating piston. The expansion chamber is filled with gas, and the separating piston separates the filled with oil second working space of the gas-filled compensation chamber.

The compensation chamber is used to compensate for the displacement of the oil in the work spaces in the damper tube when the piston rod enters the damper tube, so that the separating piston performs a movement in the longitudinal axis direction and reduces the compensation space. If the piston rod moves out of the damper tube again, the expansion chamber increases again due to a relaxation of the gas. For this, the compensation chamber must be under pressure.

The vibration damper further comprises a damping valve system, which is arranged as an external module laterally on the vibration damper. The damping valve system consists of two in a cylindrical valve housing coaxial with each other arranged damping valves, each with a pressure-dependent valve and an electromagnetically controllable, cooperating with at least one flow, axially movable spool. The damping valve system serves to control damping forces in the rebound and compression stages of the shock absorber.

Due to the adjoining in the longitudinal axis direction of the work spaces in the damper tube compensation space, the vibration damper has an increased overall length, installation situations are known which require a vibration damper as short as possible. It would therefore be desirable to form the compensation chamber outside the damper tube, such that the compensation chamber does not lead to an extension of the overall length of the vibration damper in the longitudinal axis direction.

Known are so-called two-pipe vibration dampers, such as DE 10 2009 016 225 B4 shows. When designing a vibration damper with an external damping valve system, however, such a two-pipe damper can not be combined with a corresponding damper valve system, since the expansion chamber is formed in the annular space between the outer sheath and the actual damper tube, and a fluidic coupling of the damping valve system to the vibration damper is no longer possible without further ado.

Vibration damper having an external compensation space, such as DE 696 03 324 T2 shows, have a cylinder body which extends parallel to the longitudinal axis of the damper tube. With simultaneous design of the vibration damper with a damping valve system, which is also included in an external, for example, cylindrical module tube, as known from DE 43 10 341 Cl, for space reasons, depending on the installation situation, another external module with a compensation chamber in a parallel to the longitudinal axis aligned Extension not be arranged in addition to the damping valve system laterally on the damper tube.

DISCLOSURE OF THE INVENTION

The object of the invention is the development of a vibration damper with an improved arrangement of a compensation chamber. In particular, the overall length of the vibration damper should be minimized, the space around the damper tube should remain free at least in its essential extension length. Furthermore, the vibration damper should allow in relation to its overall length large spring travel. This object is achieved on the basis of a vibration damper according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous developments of the invention are specified in the dependent claims.

The invention includes the technical teaching that the compensation chamber is formed in a guide tube extending along a tube longitudinal axis, wherein the separating piston in the guide tube along the tube longitudinal axis is guided hubbeweglich and wherein the tube longitudinal axis is aligned perpendicular to the longitudinal axis of the damper tube.

By an approximately perpendicular projecting extension of the guide tube to form the compensation chamber from the actual damper tube of the vibration results in an L-shape of the shock absorber with the external compensation space, and the space around the damper tube space above the essential extension length of the damper tube remains free. The guide tube takes on the separating piston in the same way as a separating piston, which is accommodated in the longitudinal axis direction of the damper tube movable in this.

The direction of movement of the separating piston takes place in the tube longitudinal axis direction of the guide tube, and the function of the "breathing" compensation chamber can be implemented in the same way as a compensation chamber, which adjoins the second working space in the longitudinal axis direction The longitudinal axis of the damper tube may include a right angle, wherein in principle a longitudinal axis aligned pipe axis can already lead to the desired result of shortening the length of the vibration damper Advantageously, the guide tube may be mounted in the lower region of the damper tube on the outside of the vibration damper, the lower portion is formed at the end of the vibration damper, which is opposite to the lead-out piston rod.

According to a particular embodiment of the vibration damper, this has a cladding tube which at least partially encloses the damper tube to form an annular gap between the outside of the damper tube and the inside of the cladding tube, wherein the guide tube is arranged at least indirectly on the cladding tube. In the annular gap between the cladding tube and the damper tube but no compensation space is formed, which fulfills the above function. Thus, despite a double-walled design of the vibration damper, the operating principle of Vibration damper designed as a single-tube vibration damper. The advantage of the cladding tube is in particular that the arrangement of the guide tube does not have to be made directly to the damper tube, in which the damper piston is guided and must meet special accuracy requirements. In particular, can communicate through the fluidic communication of the working space with the annular gap of the compensation chamber in a simple manner with the second working space above the separating piston. It can be provided that the annular gap is fluidly connected to the second working space and that before the separating piston in the guide tube an antechamber is formed, which is fluidly connected to the annular gap. Consequently, the vestibule is fluidly connected to the second working space and filled with oil. During a "breathing" of the external compensation chamber of the separating piston moves orthogonal to the longitudinal axis of the damper tube and increases and decreases the antechamber in the guide tube.

In the context of the present invention, however, there is also the possibility that the vibration damper is designed as a single-tube vibration damper and operates according to the so-called single-chamber operating principle. Thus, the guide tube can also be arranged at least indirectly on the outside of the damper tube and communicate fluidly with the second working space on the rod side facing away from the piston rod. In particular, the vibration damper, regardless of the design with or without an externally arranged damping valve system with an external compensation chamber in perpendicular projecting design be executed, in particular also regardless of whether the vibration damper is designed as a single-tube vibration damper or as a two-tube vibration damper.

According to a further particularly advantageous embodiment of the vibration damper, the guide tube projecting substantially at right angles from the jacket tube is designed to be closed at its free end, wherein independently of the closed design of the guide tube a flange element can be provided at the open end with which the guide tube is arranged on the outside of the jacket tube , The one-sided closed guide tube can be fastened in a simple manner on the flange, and the flange can be arranged outside holding the guide tube.

For fluidic communication of the antechamber with the second working space, the flange element may have a fluid channel which is at least partially brought into coincidence with an opening made in the cladding tube. Consequently, the opening and Oil is flowed through the fluid channel when the piston rod enters and exits the damper tube.

The guide tube has an open receiving end opposite the free, closed end, wherein the flange element is inserted at least partially into the open receiving end, so that the guide tube encloses the flange element at least over a partial length. The guide tube can consequently be pushed onto the flange element, and with particular advantage the guide tube can be connected in a form-fitting manner to the flange element by means of the receiving end in the tube longitudinal axis.

Advantageously, the positive connection between the receiving end of the guide tube and the flange element may be formed by a plastic curling a peripheral bead in a groove externally provided on the flange element groove. Alternatively, isolated caulkings can be provided on the circumference, which also produces the positive connection between the guide tube and the flange element. With a corresponding wall thickness of the guide tube, the plastic molding into undercuts, recesses, grooves or notches in the outer peripheral surface of the flange element is particularly advantageous, so that a mechanically high loadable connection between the guide tube and the flange element can be generated in a simple manner. Alternatively, a welded connection between the guide tube and the flange element may be provided, wherein it is also conceivable that the guide tube is screwed with its open receiving end on the outside of the flange.

In a particularly simple manner, the connection between the flange element and the outside of the cladding tube can be produced by a welded connection, and the flange element can have a contact surface which has a concave curvature and which is brought into conformity with the curvature of the outside of the cladding tube.

Finally, the vibration damper on the outside of the cladding tube may have an external damping valve system for adjusting the damping force of the vibration damper. It can be formed between the damper tube and the cladding tube fluid channels between the damping valve system and the annulus, so that the damping valve system fluidly communicates at least with the annulus. PREFERRED EMBODIMENT OF THE INVENTION

Further, measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. It shows:

Fig. 1 is a cross-sectional view of a vibration damper with an inventively designed compensation space and

Fig. 2 is an enlarged view of the connection of a guide tube to a

Cladding tube of the vibration damper.

Figure 1 shows in a cross-sectional view a vibration damper 1 with a damper tube 10 which extends around a longitudinal axis 12 and is filled with oil. In the damper tube 10, a damper piston 11 is received in the longitudinal axis 12 hubbeweglich performed so that is formed by the damper piston 11 formed in the damper tube 10, filled with oil space in a first working space A and in a second working space B. Furthermore, the vibration damper 1 has a piston rod 13, which is connected within the damper tube 10 with the damper piston 11 and which is guided out of the damper tube 10 sealed by means of a closure package 32. The possible end positions of the damper piston 11 are marked with 1 Γ, wherein a first end position of the damper piston 1 Γ is shown adjacent to the closure package 32 at fully extended piston rod 13, and a further end position of the damper piston 1 Γ is shown in the opposite bottom region, to the one Connector 31 of the vibration damper 1 is arranged.

The vibration damper 1 further has a cladding tube 18 which encloses the damper tube 10 between the outside of the damper tube 10 and the inside of the cladding tube 18 to form an annular gap 19. On the outside of the cladding tube 18, a damping valve system 29 is mounted, which communicates fluidically with the annular space 19 and over which the damping forces in the tension and compression stage are adjustable or controllable.

On the outside of the cladding tube 18, a flange 22 is disposed, and on the flange 22, a guide tube 17 is received. The free end 21 of the guide tube 17 is executed closed and the opposite receiving end 25 of the guide tube 17 is made open. In this case, the guide tube 17 is pushed with the receiving end 25 on the flange 22 on the outside and arranged on this holding.

In the guide tube 17, a separating piston 15 is guided in a liftable manner along a pipe longitudinal axis 16 of the guide tube 17 and subdivides an anteroom 20 of a compensation chamber 14. The compensation chamber 14 is filled with gas and forms a buffer space for displaced oil volume during retraction and extension of the piston rod 13 in the Damper tube 10. The annular gap 19 is in fluid communication with the second working space B, and in the region of the arrangement of the flange 22, an opening 24 is introduced in the cladding tube 18, which is in register with a fluid channel 23 in the flange 22. Thus, a separated from the separating piston 15 vestibule 20 in the external guide tube 17 communicate with the annular gap 19 and consequently with the second working space B, so that during retraction and extension of the piston rod 13 in and out of the damper tube 10 of the separating piston 15 under compression and expansion of the gas in the compensation chamber 14 can perform its lifting movement along the pipe axis 16.

The tube longitudinal axis 16 is aligned so that it is perpendicular to the longitudinal axis 12, so that the separating piston 15 performs a lifting movement, which is aligned transversely to the lifting movement of the piston rod 13 with the damper piston 11.

The vibration damper 1 is thus adapted in an advantageous manner to a required installation situation, in which an external guide tube 17 is provided, and in which the compensation chamber 14 is arranged, so that the vibration damper 1 despite the compensation chamber 14 in its longitudinal axis 12 need not be extended. However, the essential peripheral region of the damper tube 10 or of the jacket tube 18 remains free, since this free space is necessary for the corresponding installation situation of the vibration damper 1.

Figure 2 shows a detailed view of the lower end of the vibration damper 1 in the region of the connecting piece 31, with which the vibration damper 1 can be connected, for example, to an axle of a vehicle. The connecting piece 31 is attached to the cladding tube 18, which surrounds the damper tube 10 to form an annular gap 19. The illustration shows the damper piston in an end position 1 Γ, wherein the in the annular gap 19 passing end of the damper tube 10 is made open, so that the annular gap 19 communicates fluidically with the working space in the damper tube 10.

On the outside of the cladding tube 18, the flange 22 is attached by means of a weld 33, so that in addition to the retaining arrangement of the flange 22 on the outside of the cladding tube 18 and a pressure-tight connection is made so that flowing through the fluid channel 23 oil flowing through a gap between the Flange member 22 and the outside of the cladding tube 18 can escape.

The contact surface 28 of the flange element 22 facing the cladding tube 18 may have a curvature which is adapted to the curvature of the outside of the cladding tube 18.

For form-closing reception of the guide tube 17 on the outside of the flange 22, the flange 22 has a groove 27 into which a material region of the guide tube 17 is rolled to form a peripheral bead 26. In order to additionally perform pressure-tight connection between the flange 22 and the guide tube 17, a sealing element 30 is provided, which is designed as an O-ring and is seated in a groove on the outside in the flange.

The particular advantage of the embodiment shown for the formation of the compensation chamber 14 outside the damper tube 10 and in particular outside the cladding tube 18 is that the tube longitudinal axis 16 extends approximately perpendicular to the longitudinal axis 12. Consequently, the vibration damper 1 can be made shorter in the longitudinal axis direction, wherein not in addition to the damping valve system 29, a further external module parallel to the damper tube 10 and the cladding tube 18 adjacent thereto must be arranged. The area in which the guide tube 17 protrudes from the cladding tube 18 is made non-binding in many installation situations of a vibration damper 1 for forming a strut for a motor vehicle without the protruding design of the guide tube 17 would structurally interfere with the formation of the compensation chamber 14. The structural design of the vibration damper 1 thus enables new installation situations for vibration damper 1 in motor vehicle construction, while at the same time a valve damping system 29 can be arranged externally on the damper tube 10 and the cladding tube 18 as an external module. With a compensation space according to the present invention, which is not connected or connected in or on the axle-side connection end of the vibration damper, and with a short overall length, a design which is possible according to the invention results in a particularly advantageous manner, according to which the damper piston retracts in its end position Piston rod has only a very short distance to a connector at the axle-side end of the vibration damper. The remaining dead volume in the second working space, which faces the axle-side end of the vibration damper, can be minimized when the piston rod is fully retracted.

The invention is not limited in its execution to the above-mentioned preferred embodiment. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use. All of the claims, the description or the drawings resulting features and / or advantages, including structural details or spatial arrangements may be essential to the invention both in itself and in various combinations.

C o m p a n c ia l e s t e s

1 vibration damper

10 damper tube

11.11 'damper piston

12 longitudinal axis

13 piston rod

14 compensation room

15 separating piston

16 pipe longitudinal axis

17 guide tube

18 cladding tube

19 annular gap

20 anteroom

21 free end

22 flange element

23 fluid channel

24 opening

25 recording end

26 peripheral bead

27 groove

28 contact area

29 damping valve system

30 sealing element

31 connector

32 closure package

33 weld

A first workspace

B second workspace

Claims

Patent claims

1. Vibration damper (1) with an oil-filled damper tube (10) in which a damper piston (11) in a longitudinal axis (12) of the vibration damper (1) is guided in a liftable manner and a first working space (A) of a second working space (B ) in the damper tube (10), further comprising a piston rod (13) which is connected to the damper piston (11) and sealed out of the damper tube (10), and wherein a gas filled with a compensation space (14) is provided, which is separated from the second working space (B) by means of a separating piston (15),

characterized in that the compensation chamber (14) in a along a tube longitudinal axis (16) extending guide tube (17) is formed, wherein the separating piston (15) in the guide tube (17) along the tube longitudinal axis (16) is guided in a liftable manner and wherein the tube longitudinal axis (16) is aligned perpendicular to the longitudinal axis (12) of the damper tube (10).

2. Vibration damper (1) according to claim 1, characterized in that a cladding tube (18) is provided, the damper tube (10) to form an annular gap (19) between the outside of the damper tube (10) and the inside of the cladding tube (18 ) at least partially surrounds, wherein the guide tube (17) is arranged at least indirectly on the cladding tube (18).

3. Vibration damper (1) according to claim 2, characterized in that the annular gap (19) is fluidically connected to the second working space (B) and wherein before the separating piston (15) in the guide tube (17) an antechamber (20) is formed, which is fluidically connected to the annular gap (19).

4. Vibration damper (1) according to claim 2 or 3, characterized in that from the cladding tube (18) substantially perpendicular projecting guide tube (17) is formed closed at its free end (21) and / or wherein a flange (22) provided is, with which the guide tube (17) on the outside of the cladding tube (18) is arranged.

5. Vibration damper (1) according to one of claims 2 to 4, characterized in that the flange element (22) has a fluid channel (23) which is at least partially brought into coincidence with an opening in the jacket tube (18) opening (24).

6. Vibration damper (1) according to one of claims 4 or 5, characterized in that the flange element (22) in a the free end (21) opposite receiving end (25) of the guide tube (17) is at least partially inserted, so that the guide tube ( 17) encloses the flange element (22) at least over a partial length.

7. Vibration damper (1) according to claim 6, characterized in that the guide tube (17) by means of the receiving end (25) in the tube longitudinal axis (16) is positively connected to the flange member (22).

8. Vibration damper (1) according to claim 7, characterized in that the positive connection between the receiving end (25) of the guide tube (17) and the flange (22) by a plastic curling a peripheral bead (26) in an outer circumference on the flange (22) introduced groove (27) is formed.

9. Vibration damper (1) according to one of claims 4 to 8, characterized in that the flange element (22) is welded to the outside of the cladding tube (18), for which the flange member (22) has a contact surface (28) which is a concave Has curvature and which is brought into conformity with the curvature of the outside of the cladding tube (18).

10. Vibration damper (1) according to any one of the preceding claims, characterized in that on the outside of the cladding tube (18) an external damping valve system (29) for adjusting the damping force of the vibration damper (1) is arranged.