Damper having gas-filled envelope

Abstract

The invention relates to a vibration damper having a gas-filled enclosure, comprising a working cylinder filled with a damping medium, which working cylinder forms a fluid channel with an outer side and an intermediate tube arranged on the side, said working cylinder forming an annular space with an outer container tube, which annular space acts as a compensation space, the intermediate pipe has an annular space, in which an enclosure having a gas filling is arranged, the pipe body of the intermediate pipe being held on the working cylinder by means of the guide-seal assembly, the intermediate pipe being embodied with an installation protection, which is formed by a chamber ring as a component of the guide-seal assembly, the chamber ring has an end face facing the mounting direction of the encapsulation body and an axial projection with respect to the tube body, which axial projection is provided with a sliding profile for the encapsulation body.

Description

Field of the Invention

[0001] The present invention relates to a shock absorber having an inflatable envelope as described in the preamble of claim 1 of the patent Background Art

[0002] Adjustable shock absorbers are known from the patent document DE 10 2020 201 457 A1, which have an intermediate tube that forms a fluid connection between the working space on the piston rod side and an adjustable damping valve device together with the cylinder body. The intermediate tube has an end-side guiding section with a chamber seal, wherein the intermediate tube is frictionally fixed to the cylinder body via the guiding section.

[0003] Such shock absorbers are also equipped with an inflatable envelope according to the embodiment of the patent document DE 10 2015 218 296 A1. The production and installation of such an intermediate tube have disadvantages. Additionally, great care must be taken when installing the envelope in the compensation space so as not to damage its relatively thin envelope part.

[0004] In the later patent document DE 10 2022 205 562 A1, this installation problem is solved by an installation protection part separated from the intermediate tube, which has the function of an end-side closed structural unit for fluid connection and is fixed to the end face of the intermediate tube. Therefore, the installation protection part is preferably made of plastic. Summary of the Invention

[0005] The object of the present invention is to further simplify the use of the inflatable envelope in the shock absorber.

[0006] This object is achieved in that the intermediate tube is implemented to have an installation protection part formed by a chamber ring which is a component of a guiding-sealing assembly, wherein the chamber ring has an end face facing the installation direction of the envelope and an axial protrusion relative to the tube body, and the axial protrusion is provided with a sliding profile for the envelope.

[0007] The main advantage is that, compared with the hitherto known intermediate tubes without an installation protection part, no additional components are required to achieve the desired protection function.

[0008] In another design, the chamber ring has a maximum outer diameter at least as large as the outer diameter of the tube body. In this variant, the aim is to have the chamber ring completely cover the cross-section surrounded by the tube body, such that a semi-finished product that is only simply machined on the end side can even be used as the tube body if necessary.

[0009] According to an advantageous dependent claim, the chamber ring has an axial support surface for the tube body of the intermediate tube. This basically defines the axial position of the chamber ring.

[0010] Advantageously, the guide section of the chamber ring is axially joined to the tube body of the intermediate tube. As a result, the available installation space in the shock absorber is optimally utilized, and a large guide length of the chamber ring on the working cylinder is achieved here.

[0011] In an embodiment, the outer diameter of the tube body is greater than the maximum outer diameter of the chamber ring, wherein a transition region between the end face of the tube body facing the chamber ring and the outer side forms a surface region of the sliding profile. Thereby, the volume of the chamber ring can be optimized, especially for an intermediate tube with a large outer diameter.

[0012] Furthermore, the chamber ring may also have an annular groove for receiving the end of the tube body. Here, it is also possible to select an unprocessed cut surface on the end side of the tube body, which is completely covered by the chamber ring.

[0013] In all variants, the chamber ring can be axially held on the side facing away from the fluid channel by a locking ring that is inserted into the sliding profile. The locking ring according to DIN 9925 has a round wire body that can be embedded in the sliding profile.

[0014] An alternative variant is characterized in that the chamber ring is axially held on the side facing away from the fluid channel by a locking ring that has an axial distance not only from the end face but also from the end face facing the direction of the fluid channel. This configuration provides optimal conditions for the design of the sliding profile.

[0015] To facilitate the installation of the guide-seal assembly, the position of the annular seal in the direction of the fluid channel is directly restricted by the locking ring. The locking ring can be removed during the operation of the shock absorber, but at least the unintentional sliding of the annular seal can be restricted during installation.

[0016] Optionally, the annular seal can be formed by at least one cladding of the chamber ring. Thereby, the errors resulting from the lack of an annular seal are eliminated, and the installation space required to seal the fluid channel at the chamber ring is smaller than that of a conventional seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be explained in more detail with the following description of the drawings. Among them:

[0018] Figure 1 A cross-sectional view of a shock absorber according to the present invention is shown;

[0019] Figure 2 And Figure 3 A detailed view of the installation process is shown;

[0020] Figure 4 And Figure 5 An alternative variant of the chamber ring is shown;

[0021] Figure 6and Figure 7 shows an alternative variant for sealing at the chamber ring;

[0022] Figure 8 shows an alternative arrangement of the locking ring for the chamber ring. DETAILED DESCRIPTION

[0023] Figure 1 Exemplarily shown is a shock absorber 1 having a working cylinder 3 filled with a damping medium. In the working cylinder 3, a piston rod 5 having a piston 7 is guided in an axially movable manner. The piston 7 divides the working cylinder 3 into a working space 9 on the piston rod side and a working space 11 remote from the piston rod. Depending on the desired function of the shock absorber 1, the piston 7 can be designed as a closed squeezer having at least one overpressure valve or having known damping valves. The working space 9 on the piston rod side is closed at the end side by a piston rod guide 13.

[0024] The outer side 15 of the working cylinder 3 and an intermediate tube 17 arranged on this side 15 form a fluid channel 19. The fluid channel 19 has at least one connection opening 21 and can be used as a flow connection between the working space 9 on the piston rod side and an adjustable damping valve device 23, and also for connection to the working space 11 remote from the piston rod or a bottom valve not shown. For the present invention, the specific function of the fluid channel 19 is not important.

[0025] Furthermore, the working cylinder 3 and an external container tube 25 form an annular space, which serves as a compensation space 27 for the volume of the damping medium squeezed by the piston rod 5. The piston rod guide 13 also closes the compensation space 27 at the end side and is sealingly connected to the container tube 25.

[0026] The compensation space 27 is filled with a volume of damping medium and additionally houses an encapsulation body 29 with a gas filling 31. The gas filling 31 keeps the volume of the damping medium under a pressure preload in order to minimize foaming of the damping medium.

[0027] The intermediate tube 17 includes a rigid tube body 33, which is implemented such that the end of the opening facing the direction of the piston rod guide 13 is closed by a guide-seal assembly 35 and held at the working cylinder 3. Due to the operating pressure occurring, the intermediate tube 17 is usually made of a metallic material. However, for the present invention, the choice of material is equally unimportant.

[0028] Figure 2 shows a section of the shock absorber 1 in the installed state Figure 1 where the encapsulation body 29 has not yet reached its final position according to Figure 1 the provisions. The structural configuration of the guide-seal assembly 35 can be clearly identified in this enlarged view.

[0029] The intermediate tube 17 as a complete component includes a chamber ring 37 within the guide-seal assembly 35, which chamber ring has an end face 39 facing the installation direction of the encapsulation body 29 and an axial projection 41 relative to the tube body 33 of the tube. The axial projection has a sliding profile 43 for the encapsulation body 29 on the side thereof facing away from the working cylinder 3, and thus forms an installation protection portion for the encapsulation body 29 that is separated from the tube body 33 of the intermediate tube 17.

[0030] In the simplest embodiment, the chamber ring 37 has a maximum outer diameter that is at least as large as the outer diameter of the tube body 33. Thus, the chamber ring 37 covers the entire cross-sectional profile of the tube body 33, wherein the sliding profile 43 extends from the end face 45 of the tube body 33 until the inner diameter of the chamber ring 37. A small axial gap may exist between the end face 45 and the chamber ring 37, but the axial gap is narrow enough that it will never have a negative impact on the installation process.

[0031] Additionally, the chamber ring 37 has an axial support surface 47 for the tube body 33 of the intermediate tube 17. This support surface 47 can be used, for example, to connect the working cylinder 3 to the intermediate tube 17 and the end-side bottom group 49 ( Figure 1 ) by a form-fit connection.

[0032] The guide section 51 of the chamber ring 37 axially engages into the tube body 33 of the intermediate tube 17 and centers the tube body 33 relative to the working cylinder 3 with its outer side surface. The support surface 47 limits the axial insertion depth of the chamber ring 37 in the tube body 33.

[0033] The chamber ring 37 is axially held on the side facing away from the fluid channel 19 by a locking ring 53, which is inserted into the end face 39 and thus into the sliding profile 43. The sliding profile 43 can have a spherical or conical profile trend. Ultimately, the goal is to achieve as continuous a transition as possible between the outer side surface 15 of the working cylinder 3 and the outer side surface 54 of the tube body 33 so that no edges that could damage the encapsulation body 29 are created.

[0034] In the direction of the fluid channel 19, the annular seal 55 is at least indirectly axially supported at the chamber ring 37. In this embodiment, a support ring 57 is placed between the chamber ring 37 and the annular seal 55, which support ring prevents the annular seal 55 from being squeezed into a possible gap due to manufacturing tolerances between the chamber ring 37 and the inner wall 58 of the tube body 33. On the other hand, the position of the annular seal 55 in the direction of the fluid channel 19 is also directly limited by a second locking ring 59. This second locking ring 59 is only used to basically position the annular seal 55 on the working cylinder 3 during the installation process.

[0035] Figure 3The shock absorber 1 in its final installed state is shown, where the encapsulation body 29 axially overlaps with the tube body 33 and the chamber ring 37, and the inner side of the encapsulation body 29 does not necessarily come into direct contact with the intermediate tube 17. During installation, the encapsulation body 29 within the compensation space 27 can be pushed onto the sliding profile 43, which performs a ramp function and thus guides the encapsulation body.

[0036] Figure 4 A variant based on the illustration according to Figure 2 is shown, where the outer diameter of the tube body 33 is greater than the maximum outer diameter of the chamber ring 37. Here, the transition region 61 between the end face 45 of the tube body 33 facing the chamber ring 37 and the outer side face 54 forms the surface area of the sliding profile 43. The tube body 33 is thus an integral part of the sliding profile 43 and can therefore, if necessary, effect an axial shortening of the chamber ring 37 or an axial lengthening of the sliding profile 43.

[0037] The basic structure of the intermediate tube 17 corresponds to the embodiment described above. The difference is that the chamber ring 37 has an annular groove 63 for receiving the end of the tube body 33 in the variant according to Figure 5 . This variant is particularly suitable for tube bodies 33 with a small wall thickness and thus a very narrow end face that can only be shaped to a limited extent.

[0038] Figure 6 A particularly compact configuration of the guide - seal assembly 35 with the chamber ring 37 is shown, which has two annular seal parts 55I, 55A that seal the chamber ring 37 and the fluid passage 19 by abutting against the side face 15 of the working cylinder 3 on one side and against the inner wall 58 of the tube body 33 on the other side, respectively. Thus, the end - side annular seal part 55 can be omitted, and in particular, the second locking ring 59 can also be omitted.

[0039] By Figure 7 , the principle of the guide - seal assembly 35 according to Figure 6 is again achieved. An alternative sealing solution is shown differently, which includes a partial cladding of the chamber ring 37 having an annular seal part 55 with a U - shaped cross - section. This cladding abuts against the side face 15 of the working cylinder with its inner annular seal part 55I and against the inner wall 58 of the tube body with its outer annular seal part 55A. Optionally, the end face of the chamber ring facing the fluid passage 19 can also have an annular seal part 55S via which the two annular seal parts 55I, 55A are connected to each other. This variant requires at least slightly less sealing - part installation space than the configuration according to Figure 6 .

[0040] According to Figure 8An embodiment of the guide - seal assembly 35 shows a locking ring 53 that is guided within an annular groove 65 of the chamber ring 37. The annular groove is axially spaced not only from the end face 39 in the direction towards the compensation space 27 but also from the end face in the direction towards the fluid channel 19. Thus, the sliding profile 43 can be designed without considering the requirements of the locking ring 53. The annular groove 65 in the chamber ring 37 and the annular groove 67 in the working cylinder 3 both qualitatively have mirror - image inlet slopes. The locking ring 53 has a slight pre - load in the direction of the working cylinder 3. For installation, the locking ring 53 is radially expanded within the annular groove 65 of the chamber ring 37 and is pushed onto the working cylinder 3 together with it. When the locking ring 53 snaps into the annular groove 67 of the working cylinder in a predetermined end position, the chamber ring 37 is then axially fixed. The working pressure present in the fluid channel 19 is generally greater than the pressure in the compensation space 27, such that the chamber ring 37 reliably holds the locking ring 53 during the operation of the shock absorber.

[0041] List of reference numerals

[0042] 1 Shock absorber

[0043] 3 Working cylinder

[0044] 5 Piston rod

[0045] 7 Piston

[0046] 9 Working space on the piston - rod side

[0047] 11 Working space away from the piston - rod

[0048] 13 Piston - rod guide

[0049] 15 Side

[0050] 17 Intermediate tube

[0051] 19 Fluid channel

[0052] 21 Connecting opening

[0053] 23 Damping valve device

[0054] 25 Container tube

[0055] 27 Compensation space

[0056] 29 Envelope

[0057] 31 Gas filling

[0058] 33 Tube body of the intermediate tube

[0059] 35 Guide - seal assembly

[0060] 37 Chamber ring

[0061] End face of the 39 - chamber ring

[0062] Axial protrusion of the 41 - chamber ring

[0063] 43 - sliding profile

[0064] End face of the 45 - tube body

[0065] 47 - axial support surface

[0066] 49 - bottom group

[0067] 51 - guiding section

[0068] 53 - locking ring

[0069] Side surface of the 54 - tube body

[0070] 55 - annular seal

[0071] 55I - inner annular seal

[0072] 55A - outer annular seal

[0073] 55S - annular seal at the end side

[0074] 57 - support ring

[0075] Inner wall of the 58 - tube body

[0076] 59 - second locking ring

[0077] 61 - transition region

[0078] Annular groove of the 63 - tube body

[0079] Annular groove in the 65 - chamber ring for the locking ring

[0080] Annular groove in the 67 - working cylinder for the locking ring

Claims

1. A vibration absorber (1), comprising a working cylinder (3) filled with a damping medium, wherein an outer side surface (15) of the working cylinder and an intermediate tube (17) arranged on the outer side surface (15) form a fluid channel (19), wherein: The working cylinder (3) forms an annular space with the external container tube (25), the annular space serving as a compensation space (27), and an enclosure (29) having a gas filling portion (31) is arranged in the annular space, wherein the tube body of the intermediate tube is held at the working cylinder by a guide-seal assembly (33), characterized in that the intermediate tube (17) is implemented to have an installation protection portion, which is formed by a chamber ring (37) as a component of the guide-seal assembly (35), wherein the chamber ring (35) has an end face (39) facing the installation direction of the enclosure (29) and an axial protrusion (41) relative to the tube body (33), and the axial protrusion is provided with a sliding contour (43) for the enclosure (29).

2. The vibration absorber (1) according to claim 1, characterized in that The chamber ring (35) has a maximum outer diameter which is at least as large as the outer diameter of the tubular body (33).

3. The vibration absorber (1) according to at least one of claims 1 or 2, characterized in that The chamber ring (37) has an axial support surface (47) for the tube body (33) of the intermediate tube (17).

4. The vibration absorber (1) according to at least one of claims 1 to 3, characterized in that The guide section (51) of the chamber ring (37) engages axially in the tube body (33) of the central tube (17).

5. The vibration absorber (1) according to at least one of claims 1, 3 or 4, characterized in that The outer diameter of the tubular body (33) is greater than the maximum outer diameter of the chamber ring (37), wherein a transition area (61) between an end face (45) of the tubular body (33) pointing in the direction of the chamber ring (37) and an outer side face (54) forms a surface area of ​​the sliding contour (43).

6. The vibration absorber (1) according to at least one of claims 1, 3 or 4, characterized in that The chamber ring (37) has an annular groove (63) for receiving the end of the tube (33).

7. The vibration absorber (1) according to at least one of claims 1 to 6, characterized in that The chamber ring (37) is axially held on the side facing away from the fluid channel (19) by a locking ring (53) which is inserted into the sliding contour (43).

8. The vibration absorber (1) according to at least one of claims 1 to 6, characterized in that The chamber ring (37) is axially held on the side facing away from the fluid channel (19) by a locking ring (53), which has an axial distance not only from the end face (39) but also from the end face pointing in the direction of the fluid channel (19).

9. The vibration absorber (1) according to at least one of claims 1 to 8, characterized in that An annular seal (55) is at least indirectly axially supported on the chamber ring (37), wherein the position of the annular seal (55) in the direction of the fluid channel (19) is directly limited by a locking ring (59).

10. The vibration absorber (1) according to at least one of claims 1 to 8, characterized in that The annular seal (55) is formed by at least one coating (55A, 55I, 55S) of the chamber ring (37).

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