Bumper cover for damper

Abstract

This invention discloses a damper cover for a damper, the damper comprising an outer tube having a tube end. A rod extends through the tube end. The damper includes a damping fluid, such as hydraulic oil, capable of moving within the damper in response to movement of the rod to provide a damping effect. The damper cover has a cup-shaped body having sidewalls and a base, the sidewalls having an inner surface and an outer surface, the inner surface being sized to press-fit onto the outer tube. The base of the damper cover has a through-hole located within the base, the through-hole being configured to allow the rod to pass through therethrough. The base has at least one fluid channel extending away from the through-hole, the at least one fluid channel being in fluid communication with a fluid reservoir in the sidewall.

Description

[0001] Cross-reference to related applications

[0002] This patent application claims priority and all benefits to U.S. Patent Application No. 17 / 088,382, filed November 3, 2020, the entire contents of which are incorporated herein by reference. Background Technology

[0003] A damper typically comprises a piston and rod arrangement located within a tube. This tube contains hydraulic fluid that resists the movement of the rod, thus providing a damping effect. A tube with a guide rod oil seal may lose its function due to natural wear, piston rod damage, or any potential damage to the guide rod. The purpose of the guide rod seal is to supply hydraulic fluid within the damper. The guide rod seal or piston rod may also malfunction due to environmental influences such as dust contamination. Where the guide rod seal or rod malfunctions, hydraulic fluid leakage may occur. Prior art provides a damper cover, typically cup-shaped, that slides on top of the damper to protect the guide rod oil seal. These prior art damper covers include ribs on their inner surface to facilitate mounting the damper cover to the end of the damper.

[0004] The damper can also exhibit static oil leakage, where a small amount of oil continuously flows through the guide rod seal due to holes in the rod surface. For example, in the case where the rod surface is chrome-plated, chrome is known to include micropores. Hydraulic oil can be trapped in the holes, and when the rod leaves the damper, the oil can exit the holes and drip down the rod as it passes through the space between the ribs on the damper cover and the damper. Although the amount of oil escaping from the damper due to the holes in the rod is small, it still gives the false impression that the oil is leaking from the damper, because the hydraulic oil released from the holes in the rod can flow down the outside of the damper. The prior art provides a damper cover that traps hydraulic oil from the holes in the rod. An improved damper cover is needed. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of a representative vehicle with multiple dampers.

[0006] Figure 2 This is a representative view of the damper.

[0007] Figure 3 This is a perspective view of a damper with a buffer cover.

[0008] Figure 4 This is a cross-sectional view of a damper with a buffer cover.

[0009] Figure 5 This is a perspective view of the buffer cover.

[0010] Figure 6This is an end view of the buffer cover.

[0011] Figure 7 It is the cross-section of the buffer cover including the oil-absorbing material. Detailed Implementation

[0012] This disclosure relates to a damper cover for a damper. The damper includes a rod and a piston capable of movement within a tube. The damper may include an outer tube and an inner tube. The tube contains a damping fluid, typically oil, such as hydraulic oil, which resists the movement of the rod and piston, thereby producing a damping effect, as known in the art. Damper types vary, including single-tube dampers, two-tube dampers, semi-active dampers, and fully active dampers. Oil can be trapped in holes on the surface of the rod as the rod moves into and out of the outer tube. During use and over time, small amounts of oil can be trapped on the surface of the rod, giving the false impression that the damper is leaking. This document discloses a cup-shaped damper cover that traps oil that may escape from the damper due to static leakage. The disclosed damper cover can be press-fitted onto the outer tube at the end of the rod and provides an integrated fluid reservoir that traps oil that can be trapped and drip from the surface of the rod. The fluid reservoir is located in the sidewall of the damper cover. The disclosed buffer cover includes a base having a fluid channel in fluid communication with the base of the disclosed buffer cover.

[0013] refer to Figure 1 The image shows a vehicle 12 with a suspension system 10 and a body. The suspension system 10 includes a damper 20 and a coil spring 22. The damper 20 can be passive, semi-active, or active. Active and semi-active dampers can have a damping level controlled by an electronic control unit (ECU) 24.

[0014] refer to Figure 2 A partial cross-sectional view of an exemplary damper 20 is shown. The damper 20 includes an outer tube 26 and an inner tube 28 disposed within the outer tube 26. As shown, the inner tube 26 and the outer tube 28 are concentric. The damper 20 includes a hydraulic fluid, such as hydraulic oil, capable of moving within the damper to provide a damping effect.

[0015] The damper 20 includes a piston and a rod 30. The piston is housed in an inner tube 28, and the rod 30 extends to the outside of an outer tube 26 via a guide rod oil seal 32. During operation, the rod 30 slides in and out of the damper 20 during the compression and rebound strokes. A damper cover 40 is fitted onto the outer tube 28 to protect the guide rod oil seal 32. As described below, the damper cover 40 also traps hydraulic oil that may escape from the damper due to static oil leakage.

[0016] In the example shown, rod 30 is chromium-plated. The chromium plating includes micropores into which hydraulic fluid can be trapped, creating a static oil leak. In a static oil leak, when rod 30 is outside damper 20, hydraulic fluid from the orifices may seep out and drip onto the outside of damper 20 over time, potentially giving the operator the false impression that the damper is leaking. This false impression could lead to unnecessary service requests.

[0017] refer to Figure 3 An external perspective view of a damper 20 with a buffer cover 40 is shown.

[0018] refer to Figure 4 The diagram shows a cross-section of a buffer cover mounted on a damper 20. The buffer cover has a generally cup-shaped body and is press-fitted onto the top or end of the damper 20. The buffer cover includes a base 42 and continuous sidewalls 44.

[0019] The buffer cover 40 includes a top rod hole 46 through which the rod 30 passes. In an exemplary embodiment, a small gap is provided between the rod 30 and the rod hole 46, such that the buffer cover 40 does not mechanically interfere with the rod 30. It should be understood that... Figure 4 The rod or guide rod is not shown.

[0020] The base 42 includes at least one fluid passage 48 fluidly connected to at least one fluid reservoir 50 in the sidewall 44. When hydraulic oil escapes from the bore of the rod 30 due to static oil leakage, the hydraulic oil enters the fluid passage 48 and flows into the fluid reservoir 50 on the sidewall 44. The ability to capture fluid trapped in the rod bore can be increased by adding more fluid passages and more fluid reservoirs, or by making the sidewall relatively thicker or longer.

[0021] A vent 52 may be provided at the junction of the base 42 and the sidewall 44. The base 42 has at least one fluid channel 48 extending radially outward from the rod hole 46, and has four fluid channels as shown in the exemplary figures. Each fluid channel 48 is fluidly connected to a fluid reservoir 50 located in the sidewall 44. It should be understood that any number of fluid channels 48 and fluid reservoirs 50 may be provided, and the four channels 48 shown are exemplary. As shown, each fluid channel has a corresponding fluid reservoir. Figure 4 As shown, each fluid passage in the base includes an associated vent 52. When the fluid reservoir 50 is full, hydraulic oil can enter the environment through the vent 52. The volume of the fluid reservoir 50 can be determined to have a value corresponding to the static oil leakage that the damper 20 can accommodate, with some dampers capable of accommodating a larger static oil leakage than others.

[0022] Vent 42 may be located at the junction of base 42 and sidewall 44. As shown, vent 52 is larger in base 42 than in sidewall 44. Vent 52 ensures that all captured hydraulic oil resides in the sidewall of buffer cover 40. The sidewall 44 of buffer cover 40 may be extended in length to provide more usable space for fluid reservoir 50.

[0023] During operation, as oil is trapped in the bore of rod 30 and transported from the outside to damper 20, it falls from the bore into the fluid passage 48 of base 42, as indicated by arrow 54. The oil then falls into the fluid reservoir 50 in sidewall 44, as indicated by arrow 56. In this way, the small amount of hydraulic oil escaping from damper 20 does not provide the false impression of hydraulic fluid leakage from damper 20. - If the fluid reservoir 50 is full, oil can escape from damper cover 40 through vent 52, as indicated by dashed arrow 58.

[0024] refer to Figure 5 The figure shows a perspective view of the buffer cover 40. It can be seen that the fluid passage 48 can be accessed adjacent to the rod hole 46. As shown, a recess 62 is provided adjacent to the vent 58. The width of the recess 62 is smaller than that of the vent 58. When the oil reaches the capacity of the fluid reservoir 50, the oil will escape from the recess 62.

[0025] refer to Figure 6 The image shows an end view of the buffer cover 40. The buffer cover 40 includes a substantially smooth inner surface 60, the dimensions of which are set to facilitate press-fitting the buffer cover 40 onto the damper 20. By press-fitting the buffer cover 40 onto the damper 20, there is substantially no gap between the buffer cover 40 and the outer wall 26 of the damper, and hydraulic oil cannot escape between the buffer cover 40 and the outer wall 26 of the damper.

[0026] refer to Figure 7 The diagram illustrates a buffer cover 40 comprising an oil-absorbing material 64 within an oil reservoir 50. This disclosure provides the ability to place an oil-absorbing material 64 within a fluid reservoir 50. The oil-absorbing material 64 can be in the form of foam, chemical, or ceramic. One advantage of certain ceramic materials is their ability to absorb oil without absorbing water. By using certain oil-absorbing materials, this disclosure provides a method for draining water from an oil reservoir. By including a water-draining material, the unintentional possibility of the oil reservoir 50 being partially filled with water, leading to accidental exposure to water, such as when launching a ship at a ramp, can be reduced.

[0027] The preferred construction of the buffer cover is by injection molding it as a single piece from a polypropylene copolymer. Other suitable polymers may also be used.

[0028] This disclosure has been described in an illustrative manner, and it should be understood that the terminology used is intended to be descriptive rather than limiting. Based on the above teachings, many modifications and variations of this disclosure are possible, and this disclosure can be practiced in ways other than those specifically described.

Claims

1. A buffer cover for a damper, the damper including an outer tube having an end, the damper including a rod extending through the end of the outer tube, the damper including a damping fluid capable of moving within the damper in response to movement of the rod, the buffer cover comprising: A cup-shaped body has sidewalls and a base. The sidewalls have an inner surface and an outer surface. The dimensions of the inner surface are set to press-fit onto the outer tube. The base has a through hole configured to allow the rod to pass through it. The base has at least one fluid channel extending away from the through hole; The sidewall has at least one fluid reservoir in fluid communication with the fluid channel, the at least one fluid reservoir being radially located between the inner and outer surfaces of the sidewall.

2. The buffer cover according to claim 1, wherein the buffer cover further comprises at least one vent located between the fluid channel and the fluid reservoir.

3. The buffer cover according to claim 2, wherein the vent is located at the corner where the base intersects the sidewall.

4. The buffer cover according to claim 1, wherein the buffer cover comprises at least four fluid channels and four fluid reservoirs, each fluid channel being in fluid communication with one of the fluid reservoirs.

5. The buffer cover according to claim 4, wherein the buffer cover includes at least four vents.

6. The buffer cover according to any one of claims 1-5, wherein the buffer cover is injection molded from a polymer.

7. The buffer cover according to claim 6, wherein the inner surface of the sidewall is smooth and abuts against the outer tube.

8. The buffer cover according to any one of claims 1-5, wherein the oil-absorbing material is located in the fluid reservoir.

9. The buffer cover according to claim 8, wherein the oil-absorbing material is ceramic.

10. A damper, the damper comprising: An outer tube having an end; the outer tube having a rod extending through the end in the outer tube. The damper includes a damper fluid that is capable of moving within the damper in response to the movement of the rod; A cup-shaped buffer cover, configured to fit onto the end of the outer tube, the buffer cover having a through hole through which the rod passes. The buffer cover has sidewalls and a base. The sidewalls have inner and outer surfaces. The inner surface is sized to press-fit onto the outer tube. The base has a through-hole configured to allow the rod to pass through it. The base has at least one fluid channel extending away from the through hole; The sidewall has at least one fluid reservoir in fluid communication with the fluid channel, the at least one fluid reservoir being radially located between the inner and outer surfaces of the sidewall.

11. The damper of claim 10, wherein the damper cover further comprises at least one vent located between the fluid passage and the fluid reservoir.

12. The damper of claim 10, wherein the damper cover further comprises at least four fluid channels and four fluid reservoirs, each fluid channel being in fluid communication with one of the fluid reservoirs.

13. The damper of claim 12, wherein the buffer cover further comprises at least four vents.

14. The damper of claim 13, wherein the vent is located at the corner where the base intersects the sidewall.

15. The damper of claim 10, wherein the rod comprises a chrome-plated surface.

16. The damper according to any one of claims 10-15, wherein the buffer cover is injection molded from a polymer.

17. The damper of claim 16, wherein the inner surface of the sidewall is smooth and abuts against the outer tube.

18. The damper according to any one of claims 10-15, wherein the damper cover comprises an oil-absorbing material located in the fluid reservoir.

19. The damper according to claim 18, wherein the oil-absorbing material is ceramic.

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