Motor vehicle shock absorber with protective tube

Abstract

The invention relates to a shock absorber for a motor vehicle, comprising: a shock absorber cylinder which is closed at at least one axial end thereof by means of a piston rod guide; a piston rod partially protruding through the piston rod guide and axially movable relative to the damper cylinder; the protective tube is connected with the piston rod and surrounds the piston rod in the circumferential direction; and a guide member arranged radially between the damper cylinder and the protective tube and axially guiding the protective tube along the damper cylinder, the guide member comprising a fixed section and an extended section extending axially from the fixed section. The motor vehicle shock absorber is characterized in that the guide component is supported on the shock absorber cylinder in the radial direction by means of the fixing section of the guide component and / or is connected to the shock absorber cylinder in a form-fitting and / or force-fitting and / or material-fitting manner, and the guide component extends axially along the shock absorber cylinder in the installed state, the extension section is arranged at an end of the guide member close to the piston rod guide, and the fixed section is arranged at an end of the guide member away from the piston rod guide.

Description

Field of the Invention

[0001] The present invention relates to a motor vehicle shock absorber according to the preamble of claim 1. Background Art

[0002] This type of shock absorber is well known from the prior art, for example.

[0003] For example, document DE10122796A1 shows a motor vehicle shock absorber which includes a shock absorber cylinder body that is closed at one of its axial ends by a piston rod guide. A piston rod configured to move axially relative to the shock absorber cylinder body passes through the piston rod guide and projects partially out. The piston rod is covered in the circumferential direction by a protective tube, wherein the protective tube is connected to the piston rod.

[0004] A guiding member is arranged radially between the shock absorber cylinder body and the protective tube, and the guiding member axially guides the protective tube along the shock absorber cylinder body.

[0005] The guiding member is substantially configured in a pot shape, wherein the bottom of the pot covers the piston rod guide, and the pot wall extends axially along the shock absorber cylinder body starting from the piston rod guide. In particular, the guiding member is axially supported on the piston rod guide by the bottom of the pot, and the bottom of the pot additionally serves as an impact surface of a shock damper fixedly connected to the piston rod during the retraction movement of the piston rod.

[0006] Since the guiding member is usually made of plastic, the bottom of the pot must be constructed particularly robustly in order to withstand the impact of the shock damper when the piston rod suddenly retracts. When this type of load is above average, premature fatigue of the material and thus rupture of the bottom of the pot cannot be completely excluded. Summary of the Invention

[0007] Therefore, an object of the present invention is to provide a motor vehicle shock absorber that overcomes the above-mentioned drawbacks.

[0008] According to the present invention, the guiding member includes a fixed section and an extension section extending axially from the fixed section, wherein the guiding member is radially supported on the shock absorber cylinder body and / or is in form-fitting connection and / or force-fitting connection and / or material-fitting connection with the shock absorber cylinder body by its fixed section, wherein the guiding member is arranged on the shock absorber cylinder body such that the guiding member extends axially along the shock absorber cylinder body in the installed state, wherein the extension section is arranged at the end of the guiding member close to the piston rod guide, and the fixed section is arranged at the end of the guiding member remote from the piston rod guide.

[0009] The piston rod guide is therefore no longer covered by the guide component and is not subject to the impact of the impact damper. The piston rod guide made of metal can withstand the impact forces of the impact damper. In addition, an additional impact disk made of metal can be used under particularly high loads, which can then be mounted on the end of the piston rod guide of the shock absorber cylinder to additionally protect the piston rod guide.

[0010] A motor vehicle shock absorber of this type usually comprises a spring seat arranged on the shock absorber tube and supporting a support spring. In order to prevent the guide member from sliding axially, it can advantageously be arranged such that it is additionally supported axially on the spring seat with its fixing section.

[0011] The guide member can usually be of essentially tubular design. However, additionally or alternatively, for reasons of reducing material and weight, the extension section can advantageously be formed by a plurality of webs protruding axially from the fixing section, with axially extending gaps between the webs.

[0012] In order to give the guide component a greater rigidity in the region of the extension section, according to an advantageous embodiment variant, at least two connecting pieces are respectively connected to one another at their ends facing away from the fixing section.

[0013] If, furthermore, the guide component is to be connected to the damper cylinder in a fixed, form-fitting manner, it is advantageously possible to design the fastening section as a closed ring.

[0014] If the emphasis is on making the guide component easier to install, its fastening section can be designed as a ring interrupted by at least one interruption point.

[0015] If it is to be avoided that grooves are provided over the entire length of the guide component in order to ensure the radial stability of the component, the interruption can advantageously be arranged in the fixing section between two connecting pieces of the guide component which are connected to one another.

[0016] According to a further advantageous embodiment variant, the fastening section can include a plurality of interruptions which are arranged on the fastening section so that the guide component extends in a meandering manner around the damper cylinder as a whole. This makes it significantly easier to compensate for manufacturing tolerances regarding the diameter of the damper tube. The guide component can thus be mounted on the damper tube significantly easier and any existing diameter differences can be easily compensated.

[0017] ​​To facilitate the installation of the guide member on the shock absorber cylinder, the guide member may also advantageously have ribs projecting radially inwards, which ribs extend axially along the fixing section and / or at least partially along the connecting piece. This reduces the contact area of the guide member, which significantly reduces the frictional force generated between the guide member and the shock absorber cylinder during the installation of the guide member. This makes it easier to install the guide member on the shock absorber cylinder and reduces the risk of damaging the surface coating on the shock absorber cylinder.

[0018] In principle, the design of the guide member can be adapted to the construction of a motor vehicle shock absorber. Thus, another advantageous embodiment variant provides that the extension section is divided into a plurality of, but at least two, axially extending sections of different diameters, which axially extending sections are each connected to one another by connecting sections. Of particular importance is to adapt the diameter of the guide member at the end of its extension section close to the piston rod guide, for example, to the dimensions of the impact disc, in order to avoid direct collision of the protective tube with the guide member. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, advantages and effects of the present invention result from the following description of preferred embodiments of the present invention. Shown herein are:

[0020] Figure 1 a perspective view of a first embodiment variant of a motor vehicle shock absorber according to claim 1;

[0021] Figure 2 is according to Figure 1 a view of the motor vehicle shock absorber shown, without the protective tube;

[0022] Figure 3 is according to Figure 1 a longitudinal sectional view of the guide member shown;

[0023] Figure 4 is according to Figure 3 a cross-sectional view of the guide member in cross-section in the fixing section shown;

[0024] Figure 5 a view of another embodiment variant of a motor vehicle shock absorber according to claim 1, without the protective tube;

[0025] Figure 6 is according to Figure 5 a longitudinal sectional view of the guide member shown;

[0026] Figure 7 is according to Figure 6 a cross-sectional view of the guide member in cross-section in the fixing section shown. DETAILED DESCRIPTION

[0027] Figure 1Shows an implementation variant of a motor vehicle shock absorber 1 designed according to the present invention. The motor vehicle shock absorber includes a shock absorber cylinder 2, which is closed at one of its axial ends on the end side by a piston rod guide 3 and covered by a shock plate 19. Further shown is a piston rod 4, which partially protrudes through the piston rod guide 3 and the shock plate 19. The piston rod 4 can move axially relative to the shock absorber cylinder 2 and, under the excitation of bumps on the road traveled during motor vehicle operation, telescopically partially retracts into or protrudes from the shock absorber cylinder 2. If a significant retraction movement of the piston rod 4 occurs, this retraction movement is blocked by an elastic shock damper 18 fixedly connected to the piston rod 4, which contacts the shock plate 19.

[0028] The protective tube 5 is fixedly connected to the piston rod 4 and protects it from external influences. Figure 1 The shown protective tube 5 has a plurality of elastic folds, which extend in the circumferential direction around the protective tube 5 and are distributed over at least one defined length section of the protective tube 5.

[0029] However, Figure 1 The design of the shown protective tube 5 is not intended to limit the present invention, as any other design of the protective tube 5 is equally applicable and effective.

[0030] In order to prevent direct contact between the protective tube 5 and the shock absorber cylinder 2 that may damage the surface coating of the shock absorber cylinder 2, Figure 1 The shown motor vehicle shock absorber 1 further includes a guiding member 6, which is arranged radially between the shock absorber cylinder 2 and the protective tube 5, thus surrounding the shock absorber cylinder 2 in the circumferential direction and axially guiding the protective tube 5 along the shock absorber cylinder 2.

[0031] The guiding member 6 includes a fixed section 7 and an extension section 9 extending axially from the fixed section 7. The fixed section 7 of the guiding member 6 is radially supported on the shock absorber cylinder 2 and / or is in form-fitting connection and / or force-fitting connection and / or material-fitting connection with the shock absorber cylinder 2.

[0032] Here, in the installed state, the guiding member 6 extends axially along the shock absorber cylinder 2, wherein the extension section 9 is arranged at the end of the guiding member 6 close to the piston rod guide, and the fixed section 7 is arranged at the end of the guiding member 6 remote from the piston rod guide.

[0033] Figure 1The external design of the guide component 6 in the embodiment variant shown is adapted to the external design of the damper cylinder 2. The extension section 9 is divided into two axial length sections 14, 15, which are each connected to each other via a connecting section 16. The first axial length section 14 extends axially from the fixing section 7 in the direction of the piston rod and has a smaller diameter than the second axial length section 15 extending to the impact disk 19.

[0034] Figure 1 、 Figure 2 and Figure 5 It is also shown that the motor vehicle shock absorber 1 includes a spring seat 17, which is mainly used to axially support a supporting spring not shown here. The spring seat 17 is arranged on the shock absorber cylinder 2 and is connected to the shock absorber cylinder 2 in an axially fixed and non-rotatable manner. The guide member 6 is axially supported on the spring seat 17 by its fixed section 7. The extension section 9 of the guide member 6 surrounds the shock absorber cylinder 2 in the circumferential direction and is formed by a plurality of connecting plates 10, which protrude axially from the fixed section 7 and extend in the direction of the piston rod guide 3. The individual connecting plates 10 are separated from each other by gaps 11 extending axially along the connecting plates 10. In Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 and Figure 6 In the embodiment variant shown, each two connecting pieces 10 are connected to each other at their ends facing away from the fixing section at the connecting point 12.

[0035] Figures 1 to 4 shows an embodiment variant of a motor vehicle shock absorber, which provides that the fastening section 7 is constructed as a closed ring. In contrast, Figures 5 to 7 An alternative embodiment is shown, according to which the substantially annular fixing section 7 is designed to be interrupted by at least one interruption 8. The interruption 8 is arranged here between two connecting pieces 10 of the guide component 6 that are connected to each other.

[0036] Especially Figure 7 It is shown that the fixing section 7 can also include a plurality of interruptions 8. These interruptions can be arranged at the fixing section 7 so that the guide component 6 extends in a meandering manner around the shock absorber cylinder 2 as a whole.

[0037] According to Figure 3 、 Figure 4 、 Figure 6 and Figure 7 In the embodiment shown, the guide member 6 may have a rib 13 protruding radially inward. The rib 13 extends axially along the fixing section 7 and / or at least partially along the connecting piece 10.

[0038] List of reference numerals:​​

[0039] 1 Motor vehicle shock absorber

[0040] 2 Shock absorber cylinder block

[0041] 3 Piston rod guiding part

[0042] 4 Piston rod

[0043] 5 Protection tube

[0044] 6 Guiding member

[0045] 7 Fixed section

[0046] 8 Interrupted part

[0047] 9 Extension section

[0048] 10 Connecting piece

[0049] 11 Gap

[0050] 12 Connection part

[0051] 13 Rib

[0052] 14 First axial length section

[0053] 15 Second axial length section

[0054] 16 Connection section

[0055] 17 Spring seat

[0056] 18 Impact damper

[0057] 19 Impact disc

[0058] L Longitudinal axis.

Claims

1. A motor vehicle shock absorber (1), comprising: a damper cylinder (2) which is closed at at least one of its axial ends by means of a piston rod guide (3), a piston rod (4) which partially protrudes through the piston rod guide (3) and is axially movable relative to the shock absorber cylinder (2), - a protective tube (5), which is connected to the piston rod (4) and surrounds the piston rod (4) in the circumferential direction, and a guide member (6) which is arranged radially between the damper cylinder (2) and the protective tube (5) and guides the protective tube (5) axially along the damper cylinder (2), wherein the guide member (6) comprises a fixing section (7) and an extension section (9) extending axially from the fixing section (7), It is characterized in that the guide member (6) is radially supported on the shock absorber cylinder (2) by means of its fixing section (7) and / or is connected to the shock absorber cylinder (2) in a form-fitting and / or force-fitting and / or material-fitting manner, and wherein the guide member (6) extends axially along the shock absorber cylinder (2) in the installed state, wherein the extension section (9) is arranged at the end of the guide member (6) close to the piston rod guide, and the fixing section (7) is arranged at the end of the guide member (6) away from the piston rod guide.

2. The motor vehicle shock absorber (1) according to claim 1, characterized in that The motor vehicle shock absorber (1) comprises a spring seat (17) arranged on the shock absorber cylinder (2), wherein the guide component (6) is supported axially on the spring seat (17) with its fastening section (7).

3. A motor vehicle shock absorber (1) according to at least one of claims 1 or 2, characterized in that The extension section (9) of the guide member (6) is formed by a plurality of connecting pieces (10) protruding in the axial direction from the fixing section (7).

4. The motor vehicle shock absorber (1) according to claim 3, characterized in that At least two of the connecting pieces (10) are connected to each other at their ends facing away from the fixing section.

5. A motor vehicle shock absorber (1) according to at least one of the preceding claims, characterized in that The fastening section (7) is designed as a closed ring.

6. Motor vehicle shock absorber (1) according to at least one of the preceding claims, characterized in that The fastening section (7) is designed as a ring interrupted by at least one interruption point (8).

7. The motor vehicle shock absorber (1) according to claim 6, characterized in that The interruption point (8) is arranged on the fastening section (7) between two connecting pieces (10) of the guide component part (6) which are connected to each other.

8. The motor vehicle shock absorber (1) according to claim 7, characterized in that The fixing section (7) comprises a plurality of interruption points (8) which are arranged on the fixing section (7) so that the guide component (6) extends in a meandering manner around the damper cylinder (2) as a whole.

9. Motor vehicle shock absorber (1) according to at least one of the preceding claims, characterized in that The guide component (6) has a rib (13) protruding radially inwards, the rib extending axially along the fixing section (7) and / or at least partially along the connecting piece (10).

10. Motor vehicle shock absorber (1) according to at least one of the preceding claims, characterized in that The extension section (9) is divided into at least two axial length sections (14, 15) of different diameters, and the axial length sections are respectively connected to each other via a connecting section (16).

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