Vibration Damper for a Vehicle

Abstract

A vibration damper is provided for a vehicle, preferably for a motor vehicle, having a wheel carrier made of metal for rotatably receiving a wheel, a damper tube arrangement at least partly made of a fiber-reinforced plastic for forming a damper fluid volume, a piston which is guided in the damper tube arrangement and includes a piston rod. The damper tube arrangement is rigidly connected to the wheel carrier and the piston rod can be connected to a body of the vehicle. A wheel carrier fluid volume is formed in the wheel carrier and which is connected to the damper fluid volume. The fluid in the wheel carrier fluid volume is in direct contact with the metal of the wheel carrier in order to transfer heat.

Claims

1. A vibration damper for a vehicle, comprising: a wheel carrier, made of metal, that rotatably receives a wheel; a damper tube arrangement, made at least in part of fiber-reinforced plastic, that forms a damper fluid volume; a piston guided in the damper tube arrangement, the piston having a piston rod and the damper tube arrangement being fixedly connected to the wheel carrier, wherein the piston rod is connectable to a body of the vehicle; a wheel carrier fluid volume, the wheel carrier fluid volume being formed in the wheel carrier and being connected to the damper fluid volume, wherein fluid in the wheel carrier fluid volume is in direct contact with the metal of the wheel carrier in order to transfer heat.

2. The vibration damper according to claim 1, wherein the damper tube arrangement is open at an end face so that the damper fluid volume transitions directly into the wheel carrier fluid volume.

3. The vibration damper according to claim 1, wherein the wheel carrier fluid volume constitutes an extension of the damper tube arrangement so that the piston, depending on position, is moved through the damper fluid volume or the wheel carrier fluid volume.

4. The vibration damper according to claim 1, wherein at least one tube of the damper tube arrangement is shorter than a maximum damper path of the piston.

5. The vibration damper according to claim 1, further comprising: a base valve arranged in the wheel carrier fluid volume.

6. The vibration damper according to claim 1, wherein the damper tube arrangement comprises an outer tube and an inner tube, a compensation fluid volume is formed between the outer tube and the inner tube, and the inner tube extends further into the wheel carrier than the outer tube so that an outer wall of the compensation fluid volume is formed, in part, by the wheel carrier.

7. The vibration damper according to claim 6, further comprising: cooling ribs arranged in the compensation fluid volume, wherein the cooling ribs are integral parts of the wheel carrier.

8. The vibration damper according to claim 6, wherein the outer tube is adhesively bonded to the wheel carrier.

9. The vibration damper according to claim 6, wherein one or more of the inner tube and the outer tube are: made completely of fiber-reinforced plastic, metal tubes around which are wound fiber-composite material, or plastic tubes around which are wound fiber-composite material.

10. The vibration damper according to claim 1, wherein the damper tube arrangement comprises only one individual tube, and at least one compensation fluid volume is formed in the wheel carrier, the fluid for the heat transfer is in direct contact with the metal of the wheel carrier in the compensation fluid volume.

11. The vibration damper according to claim 10, further comprising: cooling ribs are arranged in the compensation fluid volume, wherein the cooling ribs are integral parts of the wheel carrier.

12. The vibration damper according to claim 10, wherein the individual tube is adhesively bonded to the wheel carrier.

13. The vibration damper according to claim 10, wherein the individual tube is: made completely of fiber-reinforced plastic, a metal tube around which is wound fiber-composite material, or a plastic tube around which is wound fiber-composite material.

14. The vibration damper according to claim 1, wherein the vibration damper is a motor vehicle vibration damper.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a cross-sectional view of a vibration damper according to the invention in accordance with a first exemplary embodiment.

[0026] FIG. 2 shows the sectional view A-A indicated in FIG. 1.

[0027] FIG. 3 is a cross-sectional view of a vibration damper according to the invention in accordance with a second exemplary embodiment, and

[0028] FIG. 4 is a cross-sectional view of a vibration damper according to the invention in accordance with a third exemplary embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] Three exemplary embodiments of a vibration damper 1 will be explained hereinafter on the basis of FIGS. 1 to 4. Like or functionally alike components are provided in all exemplary embodiments with the same reference signs. The illustrations in the drawings are schematically simplified and show merely the components relevant to the invention.

[0030] The vibration damper 1 according to FIG. 1 comprises a wheel carrier 2. The wheel carrier 2 is made of metal, in particular die-cast aluminum. The wheel carrier 2 serves to rotatably receive a wheel of a vehicle, in particular of a motor vehicle. A wheel bearing 3 is therefore arranged in or on the wheel carrier 2. The wheel carrier 2 is, in particular, formed as a pivot bearing of a front axle.

[0031] The vibration damper 1 further comprises a damper tube arrangement 4 having a piston 5. The piston 5 is connected to a piston rod 6. A lower end of the damper tube arrangement 4 is fixedly connected to the wheel carrier 2. The piston rod 6 is connected to a body of the vehicle.

[0032] In the first exemplary embodiment what is known as the two-tube damper principle is shown. For this purpose, the damper tube arrangement 4 comprises an outer tube 7 and an inner tube 8. The piston 5 is guided in the inner tube 8.

[0033] The outer tube 7 is made of fiber-reinforced plastic. The inner tube 8 is made of metal.

[0034] A base valve 9 is disposed in the lower region of the inner tube 8. The damper tube arrangement 4 projects into a pocket of the wheel carrier 2. The base valve 9 is thus disposed within the wheel carrier 2.

[0035] The damper tube arrangement 4 outside the wheel carrier 2 constitutes a damper fluid volume 10. Within the wheel carrier 2, this damper fluid volume 10 transitions into a wheel carrier fluid volume 11. Depending on the actual position, the piston 5 moves in the damper fluid volume 10 or in the wheel carrier fluid volume 11. The fluid, in particular oil, in the wheel carrier fluid volume 11 is in direct contact with the metal surface of the wheel carrier 2, whereby a very good exchange of heat takes place.

[0036] The inner tube 8 is distanced from the outer tube 7, whereby a compensation fluid volume 12 is produced between the inner tube 8 and the outer tube 7. The inner tube 8 projects further into the wheel carrier 2 than the outer tube 7. The outer surface of the compensation fluid volume 12 is thus formed in part by the outer tube 7 and in part by the material of the wheel carrier 2. The compensation fluid volume 12 is partially part of the damper fluid volume 10, specifically outside the wheel carrier 2, and partially part of the wheel carrier fluid volume 11, specifically within the wheel carrier 2. In this exemplary embodiment the fluid is in direct contact with the wheel carrier 2 both via the base 14 and via the outer wall 13 of the compensation fluid volume 12.

[0037] The fluid flows into the compensation fluid volume 12 and out from the compensation fluid volume 12 via the base valve 9 in the wheel carrier fluid volume 11. This is necessary since, as the piston 5 moves, fluid is displaced by the piston rod 6.

[0038] An annular step 15 is formed in the wheel carrier 2. The outer tube 7 rests on this annular step 15. An adhesive bond 16 is also provided between the outer tube 7 and the wheel carrier 2.

[0039] The right half of FIG. 1 shows a variant of the first exemplary embodiment. In this variant, cooling ribs 17 are provided in the compensation fluid volume 12. In particular, the section A-A in FIG. 2 shows the design of the cooling ribs 17. In FIG. 2, the variant of the first exemplary embodiment is also shown again in the right half. The cooling ribs 17 are integral parts of the wheel carrier 2 and are therefore also made of metal. The heat-transfer area is decidedly increased by the cooling ribs 17.

[0040] FIG. 3 shows the vibration damper 1 in accordance with the second exemplary embodiment, formed in accordance with the single-tube damper principle.

[0041] The damper tube arrangement 4 here comprises an individual tube 18. The individual tube 18 rests in the wheel carrier 2 on the annular step 15. The damper fluid volume 10 again transitions directly into the wheel carrier fluid volume 11, whereby the piston 5, depending on position, moves in the damper fluid volume 10 or in the wheel carrier fluid volume 11.

[0042] In the wheel carrier fluid volume 11 the fluid is in direct contact with the metal of the wheel carrier 2 not only at the base 14, but also at the cylindrical wall surface.

[0043] The compensation fluid volume 12 is formed in the second exemplary embodiment by forming separate cavities in the wheel carrier 2. A ventilation channel 20 for this cavity is preferably provided.

[0044] The compensation fluid volume 12 extends in the second exemplary embodiment both in part below the base 14 and to the side of the wheel carrier fluid volume 11.

[0045] FIG. 4, with the third exemplary embodiment, shows a simpler embodiment of the compensation fluid volume 12. A bore with uniform diameter is provided in the wheel carrier 2 in the third exemplary embodiment. This bore is divided by the base valve 9 into the chamber in which the piston 5 moves and the compensation fluid volume 12 arranged therebelow.

[0046] In the second and third exemplary embodiment, the inner tube 18 is formed by a metal tube or plastic tube, around which there is again wound a fiber-composite material. However, the individual tube 18 can also be made completely from fiber-reinforced plastic in the second or third exemplary embodiment.

[0047] Equally, provision is made in the first exemplary embodiment for the outer tube 7 to be made not from pure fiber-reinforced plastic, but for a metal or plastic tube to be used in this case as well, around which there is again wound a fiber composite. The inner tube 8 according to the first exemplary embodiment can instead be made of metal, plastic, or fiber-reinforced plastic.

[0048] As shown by the three exemplary embodiments, a certain heat transfer area is always provided by the formation of the wheel carrier fluid volume 11 directly in the wheel carrier 2, at which heat transfer area the fluid is in direct contact with the metal material. The drawings show a diameter 21 of the piston 5. A cross-sectional area of the piston 5 is calculated in accordance with this diameter 21. The heat transfer area within the wheel carrier 2 advantageously corresponds to at least 1501 of this cross-sectional area.

[0049] To summarize, it should be noted that, by means of the vibration damper according to the invention in hybrid design, specifically composed of metal and plastic, and by means of the resultant omission of screw-connection interfaces, a very lightweight arrangement is produced. Furthermore, due to the omission of the outer tube 7 and therefore a use of an individual tube damper principle, significant installation space and weight can be saved. The conventional problem of heat dissipation arising in the case of fiber-composite design is solved by the local cooling within the wheel carrier 2, in particular in the region of the base valve. A further advantage results from the significant cost savings caused by the omission of pre-assembly steps.

LIST OF REFERENCE SIGNS:

[0050] 1 vibration damper [0051] 2 wheel carrier [0052] 3 wheel bearing [0053] 4 damper tube arrangement [0054] 5 piston [0055] 6 piston rod [0056] 7 outer tube [0057] 8 inner tube [0058] 9 base valve [0059] 10 damper fluid volume [0060] 11 wheel carrier fluid volume [0061] 12 compensation fluid volume [0062] 13 outer wall [0063] 14 base [0064] 15 step [0065] 16 adhesive bond [0066] 17 cooling ribs [0067] 18 individual tube [0068] 19 external winding [0069] 20 ventilation channel [0070] 21 diameter

[0071] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.