Protective tube for a vibration damper of a motor vehicle

Abstract

The invention relates to a protective tube for a vibration damper of a motor vehicle. The protective tube extends along a longitudinal axis and comprises a first segment and a second segment, wherein the two segments each have a substantially U-shaped cross section, are connected to one another in an interlocking, frictional or integral manner along their axial longitudinal extent and together form the protective tube, the circumferential extent of which has an angle of 360°. The protective tube is characterised in that the first segment comprises a position sensor fastened thereto and has a circumferential extent which is adapted to the size of the position sensor and an angle of less than 180°, wherein the angle of the circumferential extent of the second segment is the difference between the angle of the circumferential extent of the protective tube and the angle of the circumferential extent of the first segment.

Description

[0001] Protective tube for a vibration damper of a motor vehicle

[0002] The invention relates to a protective tube for a vibration damper of a motor vehicle having features of the preamble of patent claim 1. Furthermore, the present invention relates to a vibration damper having a protective tube which is designed according to patent claim 1.

[0003] Particularly in the automotive sector, vibration dampers are typically used in combination with a suspension in the chassis of a motor vehicle. Such vibration dampers are typically formed by two damper parts that are movable relative to each other, which are axially, hydraulically, or pneumatically damped relative to the longitudinal extent of the vibration damper. It is also known to use a linear sensor system on the vibration damper to detect the relative position of the two damper parts, for example, to determine the current distance of a wheel or axle suspension from the vehicle body.

[0004] For example, the publication DE 102021 213 854 A1 discloses a vibration damper. The vibration damper comprises a damper cylinder and a protective tube, which is indirectly attached to a piston rod, wherein the damper cylinder and the protective tube are arranged to be movable relative to one another in a longitudinal direction. Furthermore, the vibration damper comprises a sensor unit for detecting a relative position in the axial direction between the damper cylinder and the piston rod. The sensor unit comprises at least one signal transmitter and a position sensor for detecting the position of the signal transmitter, wherein the signal transmitter is arranged on the damper tube and the position sensor is arranged on the protective tube.

[0005] The protective tube is adapted to the size and external design of the vibration damper and is thus inextricably linked to the design of the respective vibration damper. However, this circumstance can be seen as a disadvantage when vibration dampers of different sizes and diameters are to be equipped with such a protective tube. This inevitably leads to the need to produce a separate protective tube for each vibration damper type, which requires significant investments in the corresponding tools and machinery and thus drives up manufacturing costs.

[0006] In order to reduce manufacturing costs, it is advisable to use as many identical parts as possible.

[0007] The invention is based on the object of providing an alternative protective tube which can be adapted to different vibration damper sizes and / or vibration damper types.

[0008] This object is achieved according to the invention by a protective tube having the features of patent claim 1 and a vibration damper having the features of patent claim 10. Advantageous embodiments emerge from the dependent claims, the drawings and / or the description.

[0009] A protective tube for a vibration damper of a motor vehicle, designed according to patent claim 1, extends along a longitudinal axis and comprises a first segment and a second segment. Both segments are each substantially U-shaped in cross-section, are connected to one another in a form-fitting, force-fitting, or material-fitting manner, and together form the protective tube, the circumferential extent of which has an angular dimension of 360°. Provision is made for the first segment to comprise a position sensor attached thereto and to have a circumferential extent adapted to the size of the position sensor and having an angular dimension of less than 180°, wherein the angular dimension of the circumferential extent of the second segment is a difference between the angular dimension of the circumferential extent of the protective tube and the angular dimension of the circumferential extent of the first segment.

[0010] This allows the first segment to be used as a common part in a variety of vibration damper variants. To form the protective tube, the second segment can be selected with a suitable circumferential extension and connected to the first segment. According to a further advantageous embodiment, both segments each have at least one corresponding engagement formation, which is designed to form a positive connection between the two segments. This positive connection can be separable and / or inseparable and can prevent or even prevent mutual axial and / or radial and / or circumferential relative movement.

[0011] It can advantageously be provided that the segments have an edge portion radially spaced from the longitudinal axis, having a first edge and a second edge, wherein the edges extend axially over the entire length of the respective segment. The engagement formation of the respective segment can be implemented in a simple manner in the region of at least one edge.

[0012] To simplify the formation of a positive and / or non-positive connection between the two segments, the engagement formation can, according to a further advantageous embodiment, comprise a spring element. The spring element can be integrally formed on at least one of the segments and engage with a corresponding configuration of the other segment. Alternatively, the spring element can be formed as a separate component and connect both segments to one another. The spring element can be made of a metal, an elastomer, or another suitable material.

[0013] According to a further advantageous embodiment, it is provided that at least one of the two segments has at least one plastically deformable fastening pin projecting from the edge of the edge section, which pin projects through an opening formed on the other segment and corresponding to the fastening pin, and wherein the connection of the two segments is produced by a plastic deformation of the fastening pin.

[0014] This creates a stable connection between the two segments, which can be implemented comparatively cost-effectively.

[0015] If at least one segment is made of thermoplastic material, for example the segment with fastening pins on it, these can be plastically deformed by thermal action to form a particularly stable connection between the two segments.

[0016] To simplify this connection method, the other segment can be made of a material with a higher melting temperature than the segment with the fastening pins. Thus, it is advantageous if the segments are made of materials with different melting temperatures.

[0017] A further advantageous embodiment provides that the two segments are connected to each other on at least one radial side by a common hinge formed in an edge section. This can be designed as a separable or inseparable hinge, or even as a film hinge.

[0018] According to a further advantageous embodiment, the protective tube comprises a circumferential groove formed in one axial end region, radially dividing the inner surface of the protective tube, which is designed to accommodate a protective tube support component of the vibration damper. This allows a simple, positive connection between the protective tube and the protective tube support component of the vibration damper to be formed.

[0019] Furthermore, an advantageous embodiment of a vibration damper for a motor vehicle comprises a damper cylinder, a piston rod which is guided in the damper cylinder so as to be movable at least in sections in the axial direction with respect to the longitudinal axis, a protective tube support component which is fixed axially to the piston rod, a protective tube which is connected to the protective tube support component in its axial end region facing the protective tube support component and surrounds the piston rod, and a sensor unit for detecting a relative position in the axial direction between the damper cylinder and the piston rod, wherein the sensor unit comprises a signal transmitter and a position sensor for detecting the axial position of the signal transmitter, wherein the signal transmitter is arranged on the damper cylinder and the position sensor is arranged on the protective tube.The vibration damper is characterized in that the protective tube is designed according to at least one of the preceding claims, with at least one advantageous feature explained above. This provides a vibration damper with a protective tube that can advantageously be adapted very easily and cost-effectively to different vibration damper sizes and / or types.

[0020] The invention is explained in more detail using the following exemplary embodiments with reference to the figures. The figures are schematic representations and show:

[0021] Fig. 1 : an exemplary embodiment of a protective tube according to the invention;

[0022] Fig. 2: a protective tube according to Fig. 1 in a disassembled state;

[0023] Fig. 3a: a vibration damper with a protective tube mounted on it;

[0024] Fig. 3b: an alternative vibration damper with a protective tube mounted on it;

[0025] Fig. 4 is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0026] Fig. 5 is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0027] Fig. 6 is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0028] Fig. 7 is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0029] Fig. 8a is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0030] Fig. 8b is a cross-sectional view of a protective tube according to Fig. 8a in the closed state;

[0031] Fig. 9 is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0032] Fig. 10 is a cross-sectional view of another exemplary embodiment of a protective tube according to the invention;

[0033] Fig. 11 is a partially cut-out, shortened side view of a vibration damper with a protective tube according to the invention;

[0034] Fig. 12 shows a further illustration of the vibration damper according to Fig. 11 in a plan view orientation.

[0035] Figures 1 and 2 each show a protective tube 5 for a vibration damper 1 of a motor vehicle, extending along a longitudinal axis L. The illustrated protective tube 5 comprises a first segment 6 and a second segment 7. Both segments 6, 7 have the same length. The two segments 6, 7 are each substantially U-shaped in cross-section and are connected to one another in a form-fitting and / or force-fitting and / or material-fitting manner along their axial longitudinal extent such that they jointly form the protective tube 5, which extends in the circumferential direction over an angular dimension y of 360°.

[0036] The first segment 6 comprises a fastening section for a position sensor 9 and has a circumferential extension adapted to the size of the position sensor 9. Overall, the first segment 6 has an angular dimension a of less than 180°.

[0037] The second segment 7 extends over an angular dimension ß that is greater than 180°. In particular, the angular dimension ß of the circumferential extent of the second segment 7 is a difference between the angular dimension y of the circumferential extent of the protective tube 5 and the angular dimension a of the circumferential extent of the first segment 6.

[0038] The different extensions of the two segments 6 and 7 are particularly clearly visible in Figures 2, 3a and 3b.

[0039] Figures 3a and 3b, taken together, show the flexibility of the possible applications of the protective tube 5. The first segment 6 in both figures 3a and 3b is a so-called “identical part”, whereby the size and design of the second segment 7 is adapted to the respective size and design of the respective vibration damper 1.

[0040] Figures 1, 2, and 11 show that the first segment 6 and the second segment 7 each have at least one corresponding engagement formation 14. This can be designed in different ways. For example, the engagement formation 14 can be designed as a type of toothing 23, whereby an axial relative movement of the two segments 6, 7 relative to one another can be prevented. Alternatively or additionally, the engagement formation 14 can have different connecting elements which prevent a radial movement of one segment 6, 7 relative to the other segment 7, 6.

[0041] Overall, the engagement formation 14 serves to connect the two segments 6, 7 separably or inseparably in a form-fitting and / or force-fitting manner.

[0042] The segments 6, 7 have an edge section 11 with a first edge 12 and a second edge 13, wherein the edge section 11 is radially spaced from the longitudinal axis L. The segments 6, 7 are essentially U-shaped in their cross-section, wherein the edges 12, 13 of their edge sections 11 are each arranged at the tips of the "U" and run along the entire length of the respective segment 6, 7. The engagement formation 14 of the respective segment 6, 7 is formed in the region of at least one edge 12, 13 according to all embodiments shown in Figures 1 to 12.

[0043] Figures 1, 2, 5, 6, 7, 8a, 8b, 9, 10 and 11 each show different exemplary embodiments, each of which provides that at least one of the two segments 6, 7 has at least one fastening pin 16 protruding from the edge 12, 13 of the edge section 11, which serves as a connecting element for an inseparable connection of the two segments 6, 7 to one another. The fastening pin 16 projects through an opening 17 on the other segment 7, 6, which corresponds to the fastening pin 16. In addition, the fastening pin 16 can be plastically deformable, as is shown, for example, in the right-hand part of Figure 6. In this case, the connection between the two segments 6, 7 can be produced by plastic deformation of the fastening pin 16.

[0044] The segments 6, 7 can be made of materials with different melting temperatures. Furthermore, at least one segment (6, 7) can be made of a plastic.

[0045] The engagement formation 14 of the embodiment shown in Fig. 4 of the

[0046] The protective tube 5 comprises a spring element 15, which is designed to connect the two segments 6, 7 to one another in a form-fitting and / or force-fitting manner. The spring element 15 is formed on the first segment 6, extends through the opening 17 formed in the second segment 7, and rests against the outer surface of the second segment 7.

[0047] Since Fig. 4 is a purely schematic representation, it is irrelevant at this point on which of the two segments 6, 7 the spring element 15 is formed and on which of the two segments 7, 6 the corresponding opening 17 or another corresponding configuration is formed. Thus, the spring element 15 can be formed on the second segment 7, and the corresponding opening 17 can be formed on the first segment 6.

[0048] Alternatively, the spring element 15 can be designed as a separate component and connect both segments 6, 7 to one another, as shown in Fig. 5. Fig. 5 shows two alternative spring elements 15, each designed as a separate component. On the right side of Fig. 5, for example, a spring element made of a metal is shown, while the left side shows a spring element made of an elastomer or another suitable material.

[0049] Figs. 7, 8a, 8b, 9, and 10 each show that segments 6, 7 can be connected to one another on at least one radial side by a hinge 18 formed in the edge portion 11. Figs. 9 and 10 show a separable or inseparable hinge 18, with a film hinge being depicted in Figs. 7, 8a, and 8b.

[0050] The hinges shown in Figures 7, 8a, and 8b comprise a fastening section 22. If the two segments 6, 7 are made of different materials, the film hinge can be formed on one of the two segments 6, 7 and fastened to the other segment 7, 6 by its fastening section 22. The fastening section 22 can be designed as a so-called "dovetail" and inserted into a corresponding groove. Alternatively, the fastening section 22 can comprise a fastening pin 16, which extends through a corresponding opening 17 and is plastically deformed, creating an inseparable connection between the two segments 6, 7. Figure 11 shows a vibration damper 1 for a motor vehicle. This comprises a damper cylinder 3, a piston rod 2 guided in the damper cylinder 3 for movement at least in sections in the axial direction, and a protective tube 5.A protective tube support component 4 is axially fixed to the piston rod 2 and supports a protective tube, which is connected to the protective tube support component 4 in its axial end region 19 facing the protective tube support component 4 and surrounds the piston rod 2. A position sensor 9 is arranged on the protective tube, with a signal transmitter 10 being axially fixed to the damper cylinder.

[0051] The position sensor 9 and the signal generator 10 together form a sensor unit 8 for detecting a relative position in the axial direction between the damper cylinder 3 and the piston rod 2. This is achieved by the position sensor 9 constantly detecting the axial position of the signal generator 10.

[0052] The protective tube 5 is designed according to at least one feature explained above. Furthermore, the protective tube 5 comprises a circumferential groove 21 formed in one axial end region thereof, which radially divides the inner surface 20 of the protective tube 5. The groove 21 serves to accommodate a protective tube support component 4 of the vibration damper 1, as shown in Figures 11 and 12.

[0053] Reference symbol

[0054] 1 vibration damper

[0055] 2 piston rod

[0056] 3 damper cylinders

[0057] 4 Protective tube support component

[0058] 5 Protective tube

[0059] 6 segments

[0060] 7 segments

[0061] 8 Sensor unit

[0062] 9 Position sensor

[0063] 10 signal generators

[0064] 11 Edge section

[0065] 12 edge

[0066] 13 edge

[0067] 14 Intervention formation

[0068] 15 Spring element

[0069] 16 fixing pin

[0070] 17 Breakthrough

[0071] 18 Hinge

[0072] 19 axial end area

[0073] 20 interior surface

[0074] 21 grooves

[0075] 22 Fastening section

[0076] 23 Gearing

[0077] L Longitudinal axis a Angle ß Angle

[0078] Y angle measure

Claims

Patent claims 1. A protective tube (5) for a vibration damper (1) of a motor vehicle, wherein the protective tube (5) extends along a longitudinal axis (L) and comprises a first segment (6) and a second segment (7), wherein the two segments (6, 7) are each substantially U-shaped in cross-section, are connected to one another in a form-fitting, force-fitting, or material-fitting manner along their axial longitudinal extent, and together form the protective tube (5), the circumferential extent of which has an angular dimension (y) of 360°, characterized in that the first segment (6) comprises a position sensor (9) attached thereto and has a circumferential extent which is adapted to the size of the position sensor (9) and has an angular dimension (a) of less than 180°,wherein the angular dimension (ß) of the circumferential extent of the second segment (7) is a difference between the angular dimension (y) of the circumferential extent of the protective tube (5) and the angular dimension (a) of the circumferential extent of the first segment (6).

2. Protective tube (5) according to claim 1, characterized in that the first segment (6) and the second segment (7) each have at least one mutually corresponding engagement formation (14) which is designed to connect the two segments (6, 7) to one another in a separable or inseparable manner in a form-fitting manner.

3. Protective tube (5) according to claim 2, characterized in that the segments (6, 7) have an edge section (11) which is radially spaced from the longitudinal axis (L) and has a first edge (12) and a second edge (13), wherein the edges (12, 13) extend axially over the entire length of the respective segment (6, 7) and wherein the engagement formation (14) of the respective segment (6, 7) is formed in the region of at least one edge (12, 13).

4. Protective tube (5) according to at least one of the preceding claims, characterized in that the engagement formation (14) is a spring element (15) which is designed to connect the two segments (6, 7) to one another in a form-fitting and / or force-fitting manner.

5. Protective tube (5) according to at least one of the preceding claims, characterized in that at least one of the two segments (6, 7) has at least one plastically deformable fastening pin (16) projecting from the edge (12, 13) of the edge section (11), which projects through an opening (17) formed on the other segment (7, 6) in a manner corresponding to the fastening pin (16), and wherein the connection between the two segments (6, 7) is produced by a plastic deformation of the fastening pin (16).

6. Protective tube (5) according to at least one of the preceding claims, characterized in that at least one segment (6, 7) is made of plastic.

7. Protective tube (5) according to at least one of the preceding claims, characterized in that the two segments (6, 7) are connected to one another on at least one radial side by a hinge (18) formed in the edge section (11).

8. Protective tube (5) according to at least one of the preceding claims, characterized in that the segments (6, 7) are formed from materials with different melting temperatures.

9. Protective tube (5) according to at least one of the preceding claims, characterized in that the protective tube (5) comprises a circumferential groove (21) formed in one axial end region thereof, radially dividing the inner surface (20) of the protective tube (5), for receiving a protective tube support component (4) of the vibration damper (1).

10. Vibration damper (1) for a motor vehicle comprising: a damper cylinder (3), a piston rod (2) which is guided in the damper cylinder (3) so as to be movable at least in sections in the axial direction with respect to the longitudinal axis (L), a protective tube support component (4) which is fixed axially to the piston rod (2), a protective tube (5) which is connected to the protective tube support component (4) in its axial end region (19) facing the protective tube support component (4) and surrounds the piston rod (2), a sensor unit (8) for detecting a relative position in the axial direction between the damper cylinder (3) and the piston rod (2), wherein the sensor unit (8) comprises a signal transmitter (10) and a position sensor (9) for detecting the position of the signal transmitter (10), wherein the signal transmitter (10) is arranged on the damper cylinder (3) and the position sensor (9) is arranged on the protective tube (5), characterized in that the protective tube (5) is designed according to at least one of the preceding claims.

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