CLOSURE PACKAGE, VIBRATION DAMPER, AND USE OF A SEAL HOLDER

Abstract

A closure package for a vibration damper may include a base body that is connectable to a damper tube and comprises a first end and a second end. The first end forms an end side of the damper tube and the second end is disposed in the damper tube. A seal for sealing a piston rod may be disposed in the base body. A seal holder may be disposed between the seal and the base body at the first end. The seal holder for axially fixing the seal may be connected to the base body in a form-fitting and/or force-fitting manner. The seal holder may be fusible in an emergency. For releasing the connection to the base body, the seal holder may be thermoplastically deformable upon overheating of the vibration damper.

Claims

1.-9. (canceled)

10. A closure package for a vibration damper, the closure package comprising: a base body that is connectable to a damper tube and includes a first end and a second end, wherein the first end forms an end side of the damper tube and the second end is disposed in the damper tube; a seal, which for sealing a piston rod, is disposed in the base body; and a seal holder that is disposed between the seal and the base body at the first end, wherein the seal holder is for axially fixing the seal and is connected to the base body in at least one of a form-fitting manner or a force-fitting manner, wherein the seal holder is fusible in an emergency, wherein for releasing the connection to the base body the seal holder is thermoplastically deformable upon overheating of the vibration damper.

11. The closure package of claim 10 wherein the seal holder is comprised of a material that has a thermal dimensional stability temperature in a range from 40 C. to +160 C.

12. The closure package of claim 10 wherein the base body comprises a conical holding portion that tapers towards an outside.

13. The closure package of claim 10 wherein at least one of: the seal holder is disposed at least in portions on a circumference of the seal, or the seal holder in an axial direction of the base body at least in portions projects beyond the seal in a direction toward the first end.

14. The closure package of claim 10 wherein the seal is configured in multiple parts and comprises a first rod seal for bearing on the piston rod and a second intermediate seal for sealing the rod seal relative to the base body, wherein the first rod seal and the second intermediate seal are releasably connected.

15. The closure package of claim 10 wherein a guide bush is disposed between the seal and the second end.

16. A vibration damper including a closure package that comprises: a base body that is connectable to a damper tube and includes a first end and a second end, wherein the first end forms an end side of the damper tube and the second end is disposed in the damper tube; a seal, which for guiding and sealing a piston rod, is disposed in the base body; and a seal holder that is disposed between the seal and the base body at the first end, wherein the seal holder is for axially fixing the seal and is connected to the base body in at least one of a form-fitting manner or a force-fitting manner, wherein the seal holder is fusible in an emergency, wherein for releasing the connection to the base body the seal holder is thermoplastically deformable upon overheating of the vibration damper.

17. The vibration damper of claim 16 configured as a single-tube damper.

18. The vibration damper of claim 16 configured as a dual-tube damper.

19. A seal holder that is fusible in an emergency for a closure package of a vibration damper, wherein the seal holder is thermoplastically deformable upon overheating of the vibration damper.

Description

IN SAID DRAWINGS

[0024] FIG. 1 shows a cross section through a closure package as per an exemplary embodiment according to the invention, having a multiple-part seal;

[0025] FIG. 2 shows a cross section through a closure package as per a further exemplary embodiment according to the invention, having a single-part seal; and

[0026] FIG. 3 shows a longitudinal section through a vibration damper having a closure package as per an exemplary embodiment according to the invention.

[0027] A longitudinal section of a vibration damper for the running gear of a motor vehicle is illustrated in FIG. 3. This example is a vibration damper in a single-tube construction mode. Other vibration dampers, for example vibration dampers in a dual-tube construction mode, can likewise be used in conjunction with the invention.

[0028] The vibration damper includes a damper tube 11 in which a working piston 22 is disposed so as to be axially movable. The working piston 22 is fixedly connected, for example, screwed, to a piston rod 16. Damping valves (not illustrated) through which the oil situated in the damper tube can pass for damping vibrations when the working piston 22 is moved in the damper tube 11 are configured in the working piston. The working piston 22 in a manner known per se subdivides the damper tube 11 into a first operating chamber 23 which is disposed on the side of the piston rod, and a second operating chamber 24 which is disposed on the side of the working piston 22 that is remote from the piston rod. In the case of a movement of the working piston 22, the oil situated in the damper tube 11 is moved between the two operating chambers 23, 24.

[0029] The second operating chamber 24 is axially delimited by a separating piston 25 which in a manner known per se closes off a gas chamber 26.

[0030] The guiding of the piston rod 16 and sealing of the latter is performed by a closure package, which is fixedly connected to the damper tube 11.

[0031] The emergency function of the closure package will be described by means of FIGS. 1 and 2, which show two exemplary embodiments of the closure package in the normal state, that is to say when usual operating pressures, for which the vibration damper is conceived, prevail in the vibration damper. By contrast, the closure package according to FIG. 3 is illustrated after the activated emergency function, wherein the oil situated in the damper tube 11 by virtue of overheating and the positive pressures associated therewith has been discharged in a controlled manner.

[0032] The closure packages according to FIGS. 1, 2 are illustrated independently of the vibration damper or the damper tube 11, respectively, are thus claimed per se and are suitable for being connected to the damper tube 11 in the manner shown in FIG. 3.

[0033] The closure package according to FIG. 1 comprises a base body 10 which, as is illustrated in FIG. 3, can be connected to the damper tube 11. The base body 10 is configured as a rotationally symmetrical component, the external circumference thereof being adapted to the (internal) diameter of the damper tube 11. The base body 10 comprises two axial ends 12, 13, wherein the first end 12 in the assembled state forms the end side 14 of the damper tube 11, as can be seen in FIG. 3. The first end 12 of the base body 10 is thus disposed on the external side of the damper tube 11. The second opposite end 13 in the assembled state is disposed in the damper tube 11, and delimits the first operating chamber 23 in the axial direction.

[0034] The base body 10 is sealed in relation to the damper tube 11 by two annular seals 29, 30.

[0035] The base body 10 comprises a centric recess in which a seal 15 is disposed. The seal 15 is provided for sealing the piston rod 16, as can be seen in FIG. 3. The seal 15 can be configured in multiple parts, as is illustrated in FIG. 1. To this end, the seal 15 can comprise a rod seal 19 which in use bears on the piston rod 16 and seals the latter in relation to the oil situated in the damper tube 11. The seal 15 furthermore comprises an intermediate seal 20 which in a sealing manner connects the rod seal 19 to the base body 10. The intermediate seal 20 is disposed on the circumference of the rod seal 19. The intermediate seal 20 comprises a larger diameter than the rod seal 19. The intermediate seal 20 and the rod seal 19 are releasably connected to one another.

[0036] The rod seal 19 per se can again be configured in multiple parts and comprise an annular seal 27 which is closed by a seal cap 28. The invention is not limited to a special shape of the seal.

[0037] The seal 19 is axially fixed by a seal holder 17, on the one hand, and by a bush holder 31 in the base body 10, on the other hand. The bush holder 31 comprises a centric bore in which a guide bush 21 is fixedly disposed. The guide bush 21 and the seal 19 are mutually aligned. The seal 15 is held in the axial direction in the base body 10 by the seal holder 17.

[0038] The seal 17 is disposed on the first end 12 of the base body 10 and in use is situated on the external side of the damper tube 11.

[0039] The connection between the seal holder 17 and the base body 10 is performed in a form-fitting and/or force-fitting manner. To this end, the base body 10 comprises a conical holding portion 18 which toward the outside tapers off in the axial direction. The seal holder 17 comprises a corresponding external contour such that holding forces are transmitted to the seal 15. In other words, the external shape of the seal holder 17 corresponds to the internal contour of the base body 10 which is profiled such that the seal holder 17 is held in the axial direction. FIGS. 1 and 2 show the normal state in which the seal holder 17 comprises the thermal dimensional stability thereof.

[0040] The embodiment according to FIG. 2 is constructed in a manner similar to that of the embodiment according to FIG. 1, wherein the seal holder 17 projects beyond the seal 19 predominantly in the axial direction. The functional mode is the same as in the initial embodiment according to FIG. 1. The seal holder 17 fixes the seal 15 in the base body 10.

[0041] The seal holder 17 is a seal holder which is fusible in an emergency. The term seal holder which is fusible in an emergency means that the seal holder is composed of a material, or includes such a material, which at specific temperatures which exceed the normal operating temperatures loses the thermal dimensional stability of the material. These limit temperatures are set such that the pressures to be expected at these limit temperatures do not lead to the vibration damper exploding or being damaged in an uncontrolled manner. The invention is not limited to a specific limit temperature. Said limit temperature in any case is above the operating temperature of the vibration damper. In other words, the limit temperature corresponds to the thermal dimensional stability temperature of the material of the seal holder 17.

[0042] The thermal dimensional stability temperature is generally the temperature at which the seal holder 17 is thermoplastically deformed such that said seal holder 17 is moved out of the base body 10. The form-fitting connection between the base body 10 and the seal holder 17 is cancelled herein.

[0043] The fused, or at least plastically deformed, seal holder 17 can then comprise the shape illustrated in FIG. 3, at which the seal holder 17 is released from the conical holding portion 18 of the base body 10. It can be readily seen in FIG. 3 that the seal 15 is moved out of the sealing position in the base body 10. It is indicated by two arrows that the oil situated in the damper tube 11 can leak through the annular gap between the piston rod 16 and the base body 10, said annular gap being exposed by the seal 15.

[0044] The invention is not limited to the seal holder consisting entirely of a material which is fusible in an emergency. In the case of a corresponding shape of the seal holder it may be sufficient for the seal holder to be composed only partially of the thermoplastic material which loses the shape thereof at a specific limit temperature.

LIST OF REFERENCE SIGNS

[0045] 10 Base body

[0046] 11 Damper tube

[0047] 12 First end

[0048] 13 Second end

[0049] 14 End side of the damper tube

[0050] 15 Seal

[0051] 16 Piston rod

[0052] 17 Seal holder

[0053] 18 Holding portion

[0054] 19 Rod seal

[0055] 20 Intermediate seal

[0056] 21 Guide sleeve

[0057] 22 Working piston

[0058] 23 First operating chamber

[0059] 24 Second operating chamber

[0060] 25 Separating piston

[0061] 26 Gas chamber

[0062] 27 Annular seal

[0063] 28 Seal cap

[0064] 29 Annular seal

[0065] 30 Annular seal

[0066] 31 Bush holder