Air spring with protective sleeve for ventilation

Abstract

The invention relates to an air spring for a motor vehicle, comprising a first connecting part and a second connecting part, between which an elastomeric bladder is fastened in a pressure-tight manner to the first and second connecting parts, thereby defining a pressure chamber of an elastic volume, the first connecting part is mounted in a rotatable manner relative to the connecting part of the motor vehicle via a torsion bearing ring, the torsion bearing ring is arranged between the bearing race and the first connecting part, the bearing race is connected to the connecting part of the motor vehicle, and the protective sleeve is connected to the first connecting part and the second connecting part. In this way, the airbag is protected from contamination by means of a protective sleeve, which delimits a variable volume space around the airbag, and a ventilation path for ventilating the protective sleeve opens into the space surrounded by the protective sleeve from the surroundings of the air spring through the bearing race and through the first connecting part.

Description

Technical Field

[0001] The present invention relates to an air spring for a motor vehicle according to the preamble of claim 1 of the patent claim. Background Art

[0002] Air springs or air spring struts are known in a large number of embodiments, which are supported between the chassis and the body of a motor vehicle and have an airbag, which in turn is fastened between a cover and a rolling piston. During operation, the air spring is subjected to an internal positive pressure, and the airbag rolls on the outer surface of the concentric rolling piston during spring movement, forming rolling folds. To limit expansion, the airbag is surrounded by a sleeve-shaped outer guide.

[0003] DE 10 2013 211 644 A1 discloses an air spring strut for a motor vehicle, in which the airbag, in particular its rolling folds, is protected from contamination by a protective sleeve, wherein the protective sleeve is attached on the one hand to the lower end of the outer guide and on the other hand to the support device for the rolling piston. Due to the spring movement of the air spring, the volume of the space surrounded by the protective sleeve changes, and as a result, a vacuum may occur in this space, which may cause the protective sleeve to implode or be damaged. Therefore, the air enclosed by the protective sleeve must be exchanged with the ambient air. However, the ambient air contains dust particles. This exchange allows these dust particles to enter the interior of the protective sleeve space, thereby damaging the rolling folds. For this reason, a ventilation channel is provided in the support device, which connects the surrounding environment to the protective sleeve space. The ventilation channel allows air to enter the protective sleeve space from the outside and to flow out again. As a result, no negative pressure exists in the protective sleeve space during the compression and rebound movements of the air spring strut. Summary of the Invention

[0004] The object of the present invention is to provide an air spring for a motor vehicle, in which another type of ventilation of the space defined by the protective sleeve is specified.

[0005] The object on which the present invention is based is achieved by an air spring for a motor vehicle according to the features of claim 1.

[0006] The air spring is used in an air spring system of a motor vehicle. Brief Description of the Drawings

[0007] Preferred embodiments of the present invention result from the dependent claims and the description of an exemplary embodiment with reference to the following drawings.

[0008] In the drawings:

[0009] Figure 1 An air spring according to an example is shown,

[0010] Figure 2 shows a bearing seat ring for an air spring, and

[0011] Figure 3 shows the lower part of the bearing seat ring. Detailed implementation

[0012] Figure 1 shows an air spring 1 according to an example and its main components. The rolling piston 2 serves as a first connection part connected to the vehicle body. The cover 3 serves as a second connection part for connecting to the wheel support. The air spring 1 shown here is in a so-called "upside-down position". The longitudinal axis of the air spring 1 is marked with L.

[0013] The airbag 4 is clamped between the rolling piston 2 and the cover 3 in a pressure-sealed manner. Together with these connection parts, the airbag defines a pressure chamber 5 with an elastic volume, which is filled with compressed air. The first end of the tubular airbag 4 is attached to the rolling piston 2, and the second end is attached to the cover 3. The fastening of the airbag end can be implemented by vulcanizing to the connection parts 2, 3, or by pressing the airbag end into the corresponding clamping bases of the connection parts 2, 3 with a clamping ring. In addition, the airbag 4 rolls on the rolling piston 2, forming a rolling fold 6. Another fold 7 is formed on the cover 3. The airbag 4 is provided with strength supports extending in the transverse direction and / or the axial direction.

[0014] Furthermore, the air spring 1 is rotatably movably connected to a fastening part of the vehicle body or the wheel support of a motor vehicle via a torsion support 15. In this example, this fastening part is the connection part 18 of the vehicle body. The bearing seat ring 19 is concentrically pressed under the connection part 18. Further, the torsion support 15 is assembled into the bearing seat ring 19, and the rolling piston 2 is supported on the bearing seat ring for rotatable movement mounting. According to the example, the torsion support 15 is designed as a roller support. The torsion support is arranged axially between the bearing seat ring 19 and the rolling piston 2. As a result, the rolling piston 2 is rotatably movably mounted relative to the connection part 18. In order to reduce vibrations entering the vehicle body, a damping element 21 is provided, which is arranged between the connection part 18 and the bearing seat ring 19.

[0015] Figure 1 The shown air spring 1 is in a pressure-filled operating state. Therefore, the airbag 4 is at least partially surrounded by a sleeve-shaped outer guide 8. The outer guide 8 is attached to the airbag 4 by means of a clamping ring 9 located in the pressure chamber 5. The outer guide 8 serves as a support sheath and restricts the lateral expansion of the airbag 4. The airbag 4 mainly abuts against the inner side of the outer guide 8 with its outer side, where the rolling fold 6 and the fold 7 are exposed in the normal position.

[0016] A protective sleeve 10 is provided to protect the rolling folds 6 and 7 from contamination and damage. The protective sleeve 10 is attached on the one hand to the rolling piston 2 and on the other hand to the cover 3. The corresponding protective sleeve ends are fastened to the outward-facing collars of the corresponding connecting parts via a form-fitting connection. Thus, the protective sleeve 10 delimits a space 11 relative to the airbag 4, the rolling piston 2 and the cover 3. The volume of this space 11 changes with the compression and rebound of the air spring 1, which is why this space must be ventilated.

[0017] Accordingly, in the example, a ventilation path 12 is provided which leads from the surroundings of the air spring 1 via the bearing seat ring 19 and the rolling piston 2 into the space 11 of the protective sleeve 10. This ventilation path 12 is realized by forming one or more channels (not visible) in the bearing seat ring 19 leading to cavities 17 in the rolling piston 2 and by forming one or more openings 16 in the rolling piston which establish a connection to the space 11 of the protective sleeve 10. Thus, a plurality of openings 16 are formed in the circumferential direction in the hollow cylindrical part of the rolling piston 2, which hollow cylindrical part represents the cavity 17. Use Figure 2 and Figure 3 to describe the channels in the bearing seat ring 19.

[0018] Figure 2 The bearing seat ring 19 is shown which includes a first part 13 and a second part 14. The first part 14 is shown transparently so that the ventilation path 12 can be seen. The ventilation path 12 is mainly shown by a plurality of channels 20 in the second part 14, as can be learned from Figure 3 . The second part 14 is designed such that a plurality of channels 20 with corresponding inlet orifices 22 and outlet orifices 23 are realized. Each channel 20 includes an inlet orifice 22 formed radially on the outside of the second part 14 and an outlet orifice 23 formed axially on the inside of the part 14. Starting from the respective inlet orifice 22, the channel 20 is formed by a meander 24 leading towards the outlet orifice 23. The meander 24 extends inwards, outwards and inwards again. This makes it more difficult for dust particles to enter the interior. For ease of implementation, the channels 20 are only formed at the top of the second part 14 and are covered in a lid-like manner by the first part.

[0019] List of reference numerals:

[0020] 1 Air spring

[0021] 2 First connecting part / rolling piston

[0022] 3 Second connecting part / cover

[0023] 4 Airbag

[0024] 5 Pressure chamber

[0025] 6 Scroll Fold

[0026] 7 Fold

[0027] 8 Outer Guide

[0028] 9 Clamping Ring

[0029] 10 Protective Sleeve

[0030] 11 Space

[0031] 12 Ventilation Path

[0032] 13 First Part

[0033] 14 Second Part

[0034] 15 Torsion Support Ring

[0035] 16 One Opening / Multiple Openings

[0036] 17 Cavity

[0037] 18 Connection Part

[0038] 19 Support Seat Ring

[0039] 20 One Channel / Multiple Channels

[0040] 21 Vibration Damping Element

[0041] 22 Inlet Orifice

[0042] 23 Outlet Orifice

[0043] 24 Zigzag Portion

[0044] L Longitudinal Axis

Claims

1. An air spring (1) for a motor vehicle, comprising a first connecting part (2) and a second connecting part (3), between which an elastomeric airbag (4) is fastened in a pressure-tight manner to the first connecting part and the second connecting part (3), thereby defining a pressure chamber (5) of elastic volume, the first connecting part (2) being mounted via a torsion support ring (15) so as to be rotatable relative to a connecting part (18) of the motor vehicle, the torsion support ring (15) for being rotatably mounted being arranged between a bearing race (10) and the first connecting part (2), the bearing race being connected to the connecting part (18) of the motor vehicle, a protective sleeve (10) being connected to the first connecting part (2) and the second connecting part (3), whereby the airbag (4) is protected from contamination by the protective sleeve (10), the protective sleeve (10) defining a space (11) of varying volume around the airbag (4), characterized in that A ventilation path (12) for ventilating the protective sleeve (10) leads from the surroundings of the air spring (1) through the support ring (19) and through the first connecting part (2) into a space (11) surrounded by the protective sleeve (10).

2. The air spring (1) according to claim 1, characterized in that The bearing race (10) includes a channel (20) or a plurality of channels (20).

3. The air spring (1) according to claim 1 or 2, characterized in that The bearing race (19) comprises a first portion (13) which abuts against a connecting portion (18) of the motor vehicle and a second portion (14) which abuts against the torsion support ring (15).

4. The air spring (1) according to claim 2 and 3, characterized in that The channel (20) or the channels (20) are formed in the second part (14), and the first part (13) rests on the second part (14) in a cover-like manner.

5. The air spring (1) according to any one of claims 2 to 4, characterized in that The channel (20) or channels (20) comprise respective inlet orifices (22) arranged on the outside of the second portion (14) and respective outlet orifices (23) arranged on the inside of the second portion (14).

6. The air spring (1) according to claim 5, characterized in that The channel (20) or the channels (20) comprise respective tortuosity (24) from respective inlet orifices (22) to respective outlet orifices (23).

7. The air spring (1) according to any one of claims 2 to 6, characterized in that The first connecting part (2) comprises a cavity (17) into which the passage (20) or the passages (20) of the bearing race (19) open.

8. The air spring (1) according to any one of claims 1 to 7, characterized in that An opening (16) or a plurality of openings (16) are formed in the wall of the cavity (17) of the first connecting part (2), and the opening or the plurality of openings lead to the space (11) of the protective sleeve (10).

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