A shock absorber

Abstract

This invention belongs to the technical field of vehicle parts and relates to a shock absorber, including a bottom valve assembly, a working cylinder assembly, and an external nitrogen storage cylinder. The bottom valve assembly has a damping chamber for reciprocating flow of hydraulic fluid. The external nitrogen storage cylinder includes an outer cylinder and an inner cylinder spaced apart. A floating piston is slidably mounted on the inner cylinder, dividing the inner cylinder cavity into an oil chamber and a gas chamber. An overflow chamber is formed between the outer and inner cylinders. The oil chamber and the overflow chamber are connected through an overflow hole. The overflow chamber is connected to the working cylinder assembly through a return channel. The overflow hole is located at the top of the oil chamber. The shock absorber provided by this invention can solve the technical problem of hydraulic fluid cross-flow in existing nitrogen shock absorbers.

Description

Technical Field

[0001] This invention belongs to the technical field of vehicle parts and relates to a shock absorber. Background Technology

[0002] Nitrogen shock absorbers are widely used in off-road vehicles, high-performance passenger cars, and industrial equipment. Existing nitrogen shock absorbers typically include a working cylinder assembly, an external nitrogen reservoir, and a damping valve system. The working cylinder assembly contains a piston assembly, an upper damping chamber, and a lower damping chamber. The external nitrogen reservoir contains a floating piston that divides the reservoir's interior into an oil chamber and a gas chamber, with the gas chamber filled with high-pressure nitrogen.

[0003] When the shock absorber is working, the oil flows back and forth between the lower damping chamber, the external nitrogen storage cylinder, and the damping valve system. The damping valve system generates damping force, and the compressibility of nitrogen creates a gas spring effect. The oil chamber of the external nitrogen storage cylinder is directly connected to the lower damping chamber. After the oil enters the oil chamber, it pushes the floating piston to compress the gas chamber. During rebound, the floating piston resets under the pressure of the gas chamber, pushing the oil back into the lower damping chamber.

[0004] Although both the upper damping chamber and the lower damping chamber of a shock absorber are sealed cavities, under high pressure, oil in the upper damping chamber may enter the lower damping chamber, and vice versa. This phenomenon is called oil leakage, and it severely affects the performance of the shock absorber. When oil from the upper damping chamber leaks into the lower damping chamber, it increases the amount of oil in the lower damping chamber, thereby reducing the gas chamber space of the external nitrogen storage cylinder, increasing the compression damping of the shock absorber, and making the ride stiffer. When oil from the lower damping chamber leaks into the upper damping chamber, the floating piston of the gas cylinder reaches its bottom, causing air bubbles to form in the lower damping chamber, resulting in larger changes in riding damping. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a shock absorber to solve the technical problem of oil cross-flow in existing nitrogen shock absorbers.

[0006] To solve the above-mentioned technical problems, the objective of this invention is achieved through the following technical solution:

[0007] A shock absorber includes a bottom valve assembly, a working cylinder assembly, and an external nitrogen storage cylinder. The external nitrogen storage cylinder includes an outer cylinder body and an inner cylinder body spaced apart. A floating piston is slidably mounted on the inner cylinder body, dividing the cavity of the inner cylinder body into a cylinder oil chamber and a gas chamber. An oil overflow chamber is formed between the outer cylinder body and the inner cylinder body. The cylinder oil chamber and the oil overflow chamber are connected through an oil overflow hole. The oil overflow chamber is connected to the working cylinder assembly through a return channel. The oil overflow hole is located at the top of the cylinder oil chamber.

[0008] As a further improvement of the present invention, the bottom of the floating piston is provided with an oil chamber sealing ring and the top is provided with an air chamber sealing ring. An annular oil overflow groove is provided in the middle of the inner wall of the inner bottle. The oil overflow hole is opened on the annular oil overflow groove and penetrates the inner bottle. When the floating piston moves to the annular oil overflow groove, a conductive gap is formed between its oil chamber sealing ring and the annular oil overflow groove.

[0009] As a further improvement of the present invention, the annular oil overflow groove includes an upper conical groove, a cylindrical groove and a lower conical groove arranged sequentially from top to bottom, and the oil overflow hole is opened on the cylindrical groove or simultaneously on the cylindrical groove and the upper conical groove; specifically, the radial dimension of the upper conical groove gradually increases from top to bottom, and the radial dimension of the lower conical groove gradually increases from bottom to top, and the upper conical groove and the lower conical groove smoothly transition with the inner wall of the inner bottle and the cylindrical groove, respectively.

[0010] As a further improvement of the present invention, there are two or more overflow holes, which are located at the same axial position in the annular overflow groove and are evenly distributed along the circumference.

[0011] As a further improvement of the present invention, the bottom valve assembly is provided with a stepped gas cylinder mounting seat, the outer cylinder body and the inner cylinder body are respectively adapted to their respective stepped mounting structures, and the outer cylinder body and the inner cylinder body are coaxially arranged; specifically, the inner cylinder body and the outer cylinder body are concentrically assembled, and the outer cylinder body and the bottom valve assembly are fastened together by threads.

[0012] As a further improvement of the present invention, the top of the inner wall of the outer bottle is provided with an inwardly extending first protruding ring, and the top of the inner bottle is provided with an outwardly extending second protruding ring. The second protruding ring is sealed to the inner wall of the outer bottle and abuts against the bottom of the first protruding ring. The middle of the inner bottle is provided with an outwardly extending third protruding ring, and an oil overflow sealing ring that is sealed to the inner wall of the outer bottle is fitted on the third protruding ring. The third protruding ring, the outer bottle, and the inner bottle form the oil overflow cavity.

[0013] As a further improvement of the present invention, the working cylinder assembly is provided with a damping upper chamber and a damping lower chamber. The damping lower chamber is formed by a first cylinder, a second cylinder and a third cylinder arranged coaxially, and includes a working chamber inside the third cylinder, an oil storage chamber between the third cylinder and the second cylinder, and an oil return chamber between the second cylinder and the first cylinder. A piston assembly is slidably arranged inside the working cylinder assembly. The damping upper chamber is connected to the working chamber through a one-way oil seal, the oil storage chamber is connected to the top of the working chamber, the oil return chamber is connected to the damping upper chamber, and the return flow channel is connected to the oil return chamber.

[0014] As a further improvement of the present invention, a guide sleeve is fixed to the top of the second cylinder, the piston assembly is slidably disposed in the guide sleeve, the one-way oil seal is disposed between the guide sleeve and the piston assembly, and the guide sleeve is clearance-fitted with the first cylinder.

[0015] As a further improvement of the present invention, the return channel is opened in the bottom valve assembly, with one end connected to the bottom of the overflow chamber and the other end connected to the bottom of the return chamber.

[0016] As a further improvement of the present invention, the bottom valve assembly is provided with a compression damping chamber and a rebound damping chamber. A compression damping valve is provided in the compression damping chamber and a rebound damping valve is provided in the rebound damping chamber. The inlet end of the compression damping valve is connected to the working chamber and the outlet end is connected to the outlet end of the rebound damping valve. The inlet end of the rebound damping valve is connected to the oil storage chamber and the outlet end is connected to the gas cylinder oil chamber.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. This invention provides a shock absorber that utilizes a double-layered cylinder structure within an external nitrogen storage cylinder. An overflow chamber and an overflow hole connect the cylinder's oil chamber to the working cylinder assembly's return oil chamber, thus partially connecting the upper damping chamber and the lower damping chamber. Oil from the lower damping chamber enters the cylinder's oil chamber and overflows through the top overflow hole to the overflow chamber, then returns to the upper damping chamber via a return channel, forming a complete oil balance circuit. This design fundamentally suppresses oil cross-contamination, preventing oil from flowing inside the working cylinder and significantly improving the shock absorber's performance consistency and long-term reliability.

[0019] 2. The damping lower chamber of this invention adopts a three-cylinder structure. A working chamber is formed within the third cylinder, an oil storage chamber connecting the working chamber is formed between the second and third cylinders, and a return oil chamber connecting the upper damping chamber is formed between the first and second cylinders. When oil flows through the upper chamber, the oil returns precisely to the upper damping chamber via the overflow hole, overflow chamber, return channel, and return oil chamber, maintaining a total oil balance. The oil storage chamber and return oil chamber of this invention are physically separated, ensuring that oil flow does not interfere with each other. This results in more stable damping force during compression and rebound strokes. The three cylinders are coaxially stacked, with clear functional partitions and reliable assembly. Attached Figure Description

[0020] Figure 1 This is the front view of the present invention;

[0021] Figure 2 This is an axial sectional view of the present invention;

[0022] Figure 3 yes Figure 2 Enlarged view of point A;

[0023] Figure 4 yes Figure 2 Enlarged view of point B;

[0024] Figure 5 This is an axial sectional view of the external nitrogen storage cylinder of the present invention;

[0025] Figure 6 yes Figure 5 Enlarged view of point C;

[0026] Figure 7 This is a structural diagram of the base valve assembly of the present invention;

[0027] Figure 8 yes Figure 7 A sectional view;

[0028] Reference numerals: 1. Bottom valve assembly; 11. Return channel; 12. Compression damping chamber; 13. Rebound damping chamber; 14. Compression damping valve; 15. Rebound damping valve; 16. Gas cylinder mounting base; 2. Working cylinder assembly; 20. Upper damping chamber; 21. First cylinder body; 22. Second cylinder body; 23. Third cylinder body; 24. Working chamber; 25. Oil reservoir; 26. Return oil chamber; 27. Piston assembly; 28. One-way oil seal; 29. ​​Guide sleeve; 3. 31. External nitrogen storage cylinder; 32. Outer cylinder body; 33. First convex ring; 34. Inner cylinder body; 35. Second convex ring; 36. Third convex ring; 37. Oil overflow sealing ring; 38. Floating piston; 39. Oil chamber sealing ring; 30. Gas chamber sealing ring; 31. Gas cylinder oil chamber; 32. Gas chamber; 33. Oil overflow chamber; 34. Oil overflow hole; 35. Annular oil overflow groove; 36. Upper conical groove; 37. Columnar groove; 38. Lower conical groove. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-8 :

[0030] This embodiment provides a shock absorber. For example... Figure 1 and attached Figure 2 As shown, the shock absorber includes a bottom valve assembly 1, a working cylinder assembly 2, and an external nitrogen storage cylinder 3.

[0031] like Figure 3 As shown, the bottom valve assembly 1 is provided with a compression damping chamber 12 and a rebound damping chamber 13. A compression damping valve 14 is provided in the compression damping chamber 12, and a rebound damping valve 15 is provided in the rebound damping chamber 13. The inlet end of the compression damping valve 14 is connected to the working chamber 24, and the outlet end is connected to the outlet end of the rebound damping valve 15. The inlet end of the rebound damping valve 15 is connected to the oil storage chamber 25, and the outlet end is connected to the gas cylinder oil chamber 34.

[0032] like Figure 5As shown, the external nitrogen storage cylinder 3 includes an outer cylinder body 31 and an inner cylinder body 32 spaced apart. The outer cylinder body 31 and the inner cylinder body 32 are coaxially arranged, forming a radial gap between them. A floating piston 33 is slidably disposed within the inner cylinder body 32. The floating piston 33 divides the cavity of the inner cylinder body 32 into a lower oil chamber 34 and an upper gas chamber 35. The gas chamber 35 is filled with high-pressure nitrogen to provide a gas spring effect. An oil chamber sealing ring 331 is provided at the bottom of the floating piston 33, and a gas chamber sealing ring 332 is provided at the top. The oil chamber sealing ring 331 and the gas chamber sealing ring 332 are used for oil-gas separation.

[0033] An oil overflow chamber 36 is formed between the outer cylinder body 31 and the inner cylinder body 32. The gas cylinder oil chamber 34 and the oil overflow chamber 36 are connected through an oil overflow hole 37. The oil overflow hole 37 is located at the top of the gas cylinder oil chamber 34. The oil overflow chamber 36 is connected to the working cylinder assembly 2 through a return channel 11. An annular oil overflow groove 38 is formed in the middle of the inner wall of the inner cylinder body 32. The oil overflow hole 37 is formed on the annular oil overflow groove 38 and penetrates the inner cylinder body 32. When the floating piston 33 moves to the position of the annular oil overflow groove 38, a conductive gap is formed between the oil chamber sealing ring 331 and the annular oil overflow groove 38.

[0034] like Figure 6 As shown, in a preferred embodiment, the annular oil overflow groove 38 includes an upper conical groove 381, a cylindrical groove 382, ​​and a lower conical groove 383 arranged sequentially from top to bottom. The oil overflow hole 37 is formed on the cylindrical groove 382, ​​or simultaneously on both the cylindrical groove 382 and the upper conical groove 381. Specifically, the radial dimension of the upper conical groove 381 gradually increases from top to bottom, and the radial dimension of the lower conical groove 383 gradually increases from bottom to top. The upper conical groove 381 and the lower conical groove 383 smoothly transition with the inner wall of the inner bottle 32 and the cylindrical groove 382, ​​respectively. This structural design allows the oil chamber sealing ring 331 to smoothly pass through the upper conical groove 381 and enter the cylindrical groove 382 when the floating piston 33 moves upward into the overflow area, reducing impact and wear; when the floating piston 33 returns to its original position downward, the lower conical groove 383 also serves as a smooth transition. There can be two or more overflow holes 37, which are located at the same axial position of the annular overflow groove 38 and are evenly distributed along the circumference to ensure the uniformity of oil flow during overflow.

[0035] like Figure 2 As shown, the external nitrogen storage cylinder 3 is installed via a stepped cylinder mounting seat 16 mounted on the bottom valve assembly 1. Specifically, the bottom valve assembly 1 is provided with a stepped cylinder mounting seat 16, and the outer cylinder body 31 and the inner cylinder body 32 are respectively adapted to their corresponding stepped mounting structures, thereby achieving coaxial positioning and fixation of the outer cylinder body 31 and the inner cylinder body 32. The inner cylinder body 32 and the outer cylinder body 31 are concentrically assembled, and the outer cylinder body 31 is fastened to the bottom valve assembly 1 by threads.

[0036] The specific assembly structure of the outer bottle body 31 and the inner bottle body 32 is as follows: A first protruding ring 311 extending inward is provided at the top of the inner wall of the outer bottle body 31. A second protruding ring 321 extending outward is provided at the top of the inner bottle body 32. The second protruding ring 321 is sealed to the inner wall of the outer bottle body 31 and abuts against the bottom of the first protruding ring 311, thereby achieving axial positioning and top sealing of the inner bottle body 32. A third protruding ring 322 extending outward is provided in the middle of the inner bottle body 32. An oil overflow sealing ring 323, which is sealed to the inner wall of the outer bottle body 31, is fitted onto the third protruding ring 322. The third protruding ring 322, the outer bottle body 31, and the inner bottle body 32 form an oil overflow cavity 36.

[0037] like Figure 3 and Figure 4 As shown, the working cylinder assembly 2 is provided with a damping upper chamber 20 and a damping lower chamber. The damping lower chamber is surrounded by a first cylinder body 21, a second cylinder body 22, and a third cylinder body 23 arranged coaxially. It includes a working chamber 24 in the third cylinder body 23, an oil storage chamber 25 between the third cylinder body 23 and the second cylinder body 22, and an oil return chamber 26 between the second cylinder body 22 and the first cylinder body 21. A piston assembly 27 is slidably disposed in the working cylinder assembly 2. The damping upper chamber 20 is connected to the working chamber 24 by a one-way oil seal 28, the oil storage chamber 25 is connected to the top of the working chamber 24, the oil return chamber 26 is connected to the damping upper chamber 20, and the return channel 11 is connected to the oil return chamber 26. As a preferred embodiment, such as Figure 7 and Figure 8 As shown, the return channel 11 is opened in the bottom valve assembly 1. One end of it is connected to the bottom of the overflow chamber 36, and the other end is connected to the bottom of the return chamber 26. This arrangement is conducive to the smooth return of the oil in the overflow chamber 36 to the return chamber 26.

[0038] Furthermore, a guide sleeve 29 is fixed to the top of the second cylinder 22, the piston assembly 27 is slidably disposed within the guide sleeve 29, the one-way oil seal 28 is disposed between the guide sleeve 29 and the piston assembly 27, and the guide sleeve 29 is clearance-fitted with the first cylinder 21.

[0039] The working principle of the shock absorber in this embodiment will be explained below. Specifically, the working process of the shock absorber is divided into two stages: compression stroke and rebound stroke.

[0040] Compression Stroke: When the shock absorber is subjected to a compressive load, the piston assembly 27 moves downward relative to the working cylinder assembly 2. Oil is compressed and damped by the compression damping valve 14 within the bottom valve assembly 1, and a portion of the oil flows back to the working chamber 24 via the oil reservoir 25. Since the piston assembly 27 enters the working chamber 24 and occupies part of its volume, excess oil is discharged to the external nitrogen storage cylinder 3. This portion of oil enters the cylinder's oil chamber 34 via the bottom valve assembly 1, pushing the floating piston 33 upward and compressing the nitrogen in the gas chamber 35.

[0041] During normal compression stroke, since the floating piston 33 is located below the annular overflow groove 38, the oil chamber sealing ring 331 is in sealing contact with the inner wall of the inner bottle 32, the overflow hole 37 is closed, and the oil in the gas cylinder oil chamber 34 cannot enter the overflow chamber 36.

[0042] When oil leakage occurs in the shock absorber, the oil in the upper shock absorber chamber 20 enters the lower damping chamber. During the compression stroke, the amount of oil entering the gas cylinder oil chamber also increases, thereby pushing the floating piston 33 to produce a larger displacement. At this time, the floating piston 33 is pushed up to the position of the annular overflow groove 38, and a conductive gap is formed between the oil chamber sealing ring 331 and the annular overflow groove 38. The oil leakage from the gas cylinder oil chamber 34 enters the annular overflow groove 38 through this gap, then overflows to the overflow chamber 36 through the overflow hole 37, then flows into the return oil chamber 26 through the return channel 11, and then returns to the upper shock absorber chamber 20 through the gap between the guide sleeve 29 and the first cylinder 21.

[0043] Rebound Stroke: When the shock absorber rebounds, the piston assembly 27 moves upward relative to the working cylinder assembly 2. After the oil generates rebound damping force through the rebound damping valve 15, it flows to the working chamber 24. Simultaneously, as the piston assembly 27 retracts from the working chamber 24, the total volume within the working chamber 24 increases, requiring oil replenishment. At this time, the compressed nitrogen gas in the gas chamber 35 expands, pushing the floating piston 33 downward to reset, pumping the oil in the gas cylinder oil chamber 34 back to the bottom valve assembly 1, flowing back to the working chamber 24.

[0044] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A shock absorber, comprising a bottom valve assembly (1), a working cylinder assembly (2), and an external nitrogen storage cylinder (3), characterized in that, The external nitrogen storage cylinder (3) includes an outer cylinder body (31) and an inner cylinder body (32) spaced apart. The inner cylinder body (32) is slidably provided with a floating piston (33). The floating piston (33) divides the cavity of the inner cylinder body (32) into a cylinder oil cavity (34) and a gas cavity (35). An overflow cavity (36) is formed between the outer cylinder body (31) and the inner cylinder body (32). The cylinder oil cavity (34) and the overflow cavity (36) are connected through an overflow hole (37). The overflow cavity (36) is connected to the working cylinder assembly (2) through a return channel (11). The overflow hole (37) is located at the top of the cylinder oil cavity (34). The bottom of the floating piston (33) is provided with an oil chamber sealing ring (331) and the top is provided with an air chamber sealing ring (332). The inner wall of the inner bottle (32) is provided with an annular oil overflow groove (38). The oil overflow hole (37) is opened on the annular oil overflow groove (38) and penetrates the inner bottle (32). When the floating piston (33) moves to the annular oil overflow groove (38), a conductive gap is formed between its oil chamber sealing ring (331) and the annular oil overflow groove (38). The working cylinder assembly (2) is provided with a shock-absorbing upper chamber (20) and a damping lower chamber. The damping lower chamber is surrounded by a first cylinder (21), a second cylinder (22) and a third cylinder (23) arranged coaxially. It includes a working chamber (24) in the third cylinder (23), an oil storage chamber (25) between the third cylinder (23) and the second cylinder (22), and an oil return chamber (26) between the second cylinder (22) and the first cylinder (21). A piston assembly (27) is slidably arranged in the working cylinder assembly (2). The shock-absorbing upper chamber (20) and the working chamber (24) are connected by a one-way oil seal (28), the oil storage chamber (25) is connected to the top of the working chamber (24), the oil return chamber (26) is connected to the shock-absorbing upper chamber (20), and the return channel (11) is connected to the oil return chamber (26).

2. A shock absorber according to claim 1, wherein The annular oil overflow groove (38) includes an upper conical groove (381), a cylindrical groove (382) and a lower conical groove (383) arranged sequentially from top to bottom, and the oil overflow hole (37) is opened on the cylindrical groove (382).

3. A shock absorber according to claim 1, wherein The annular oil overflow groove (38) includes an upper conical groove (381), a cylindrical groove (382) and a lower conical groove (383) arranged sequentially from top to bottom, and the oil overflow hole (37) is opened on both the cylindrical groove (382) and the upper conical groove (381).

4. A shock absorber according to claim 1, wherein There are two or more overflow holes (37), which are located at the same axial position of the annular overflow groove (38) and are evenly distributed along the circumference.

5. A shock absorber according to claim 1, characterized in that, The bottom valve assembly (1) is provided with a stepped gas cylinder mounting seat (16). The outer cylinder body (31) and the inner cylinder body (32) are respectively adapted to their respective stepped mounting structures. The outer cylinder body (31) and the inner cylinder body (32) are coaxially arranged.

6. A shock absorber according to claim 5, wherein The top of the inner wall of the outer bottle (31) is provided with an inwardly extending first protruding ring (311), and the top of the inner bottle (32) is provided with an outwardly extending second protruding ring (321). The second protruding ring (321) is sealed to the inner wall of the outer bottle (31) and abuts against the bottom of the first protruding ring (311). The middle of the inner bottle (32) is provided with an outwardly extending third protruding ring (322). An oil overflow sealing ring (323) that is sealed to the inner wall of the outer bottle (31) is fitted on the third protruding ring (322). The third protruding ring (322), the outer bottle (31) and the inner bottle (32) form the oil overflow cavity (36).

7. A shock absorber according to claim 1, wherein The top of the second cylinder (22) is fixed with a guide sleeve (29), the piston assembly (27) is slidably disposed in the guide sleeve (29), the one-way oil seal (28) is disposed between the guide sleeve (29) and the piston assembly (27), and the guide sleeve (29) is clearance-fitted with the first cylinder (21).

8. A shock absorber according to claim 1, wherein The return channel (11) is located inside the bottom valve assembly (1), with one end connected to the bottom of the overflow chamber (36) and the other end connected to the bottom of the return chamber (26).

9. A shock absorber according to claim 1, characterized in that, The bottom valve assembly (1) is provided with a compression damping chamber (12) and a rebound damping chamber (13). The compression damping chamber (12) is provided with a compression damping valve (14), and the rebound damping chamber (13) is provided with a rebound damping valve (15). The inlet end of the compression damping valve (14) is connected to the working chamber (24), and the outlet end is connected to the outlet end of the rebound damping valve (15). The inlet end of the rebound damping valve (15) is connected to the oil storage chamber (25), and the outlet end is connected to the gas cylinder oil chamber (34).

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