Oil pressure shock absorber

Abstract

The present disclosure discloses an oil pressure shock absorber comprising: a pressure cylinder having a pressure chamber; the piston assembly is provided with a piston part in sliding fit with the pressure cavity and a piston rod connected with the piston part, the piston part divides the pressure cavity into a front cavity adjacent to the piston rod and a rear cavity away from the piston rod, and a piston one-way valve is arranged on the piston part; the oil storage cylinder is provided with an oil storage cavity, the oil storage cavity is provided with a first side communicated with the front cavity and a second side communicated with the rear cavity, a damping valve is further arranged between the first side and the front cavity, and an oil storage one-way valve is further arranged between the second side and the rear cavity; the filtering assembly is arranged in the oil storage cavity and located between the first side and the second side. The filtering assembly is arranged between the first side and the second side of the oil storage cavity, so that the probability of failure of the damping system caused by oil leakage or unfiltered impurities can be reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to the technical field of shock absorbers. More specifically, the present disclosure relates to an oil hydraulic shock absorber. BACKGROUND

[0002] An oil hydraulic shock absorber is a component that generates damping force by orifice throttling. The diameter of the damping valve hole is generally small, and the size is a key factor in controlling the damping effect. In the process of use, impurities in the oil are prone to block the damping hole due to wear and tear of parts, external pollution, etc., causing damping force failure. There are technical solutions that propose to set a filter device at the damping valve, but such filter devices have small volume and low filtering capacity, and once the filter screen is blocked, the damping force will also fail.

[0003] Patent No. CN110094447A discloses an oil hydraulic shock absorber with a filter device, which comprises an inner cylinder, an oil storage cylinder, a piston, a piston rod, a guide seat and a bottom valve. The inner cylinder is arranged inside the oil storage cylinder, the piston is arranged inside the inner cylinder, one end of the piston rod is connected with the piston, and the other end of the piston rod passes through the inner cylinder and the oil storage cylinder in sequence. One end of the oil storage cylinder is provided with a guide seat, and the other end is provided with a bottom valve. A damping adjustment valve is arranged on the guide seat. A filter device is arranged in the annular sealing area between the inner cylinder and the oil storage cylinder. The filter device is provided with a gap on the outer side of the inner cylinder or the inner side of the oil storage cylinder. The filter device comprises a shell and a filter element arranged in the shell.

[0004] Although the patent relates to the filter device of the oil hydraulic shock absorber, since the filter device is provided with a gap on the outer side of the inner cylinder or the inner side of the oil storage cylinder, most of the oil will not pass through the filter device and enter the oil storage cylinder because the damping force of the oil flowing through the gap is smaller than the resistance of the oil flowing through the filter device. Therefore, it cannot be guaranteed that all impurities will be completely filtered, and there is still a risk that impurities will block the damping hole.

[0005] Therefore, there is an urgent need to provide an oil hydraulic shock absorber to reduce the probability of failure of the damping system caused by oil leakage or unfiltered impurities. SUMMARY

[0006] To at least solve one or more of the above-mentioned technical problems, the present disclosure proposes an oil hydraulic shock absorber.

[0007] The oil pressure shock absorber comprises a pressure cylinder having a pressure cavity, a piston assembly having a piston part in sliding fit with the pressure cavity and a piston rod connected with the piston part, the piston part dividing the pressure cavity into a front cavity adjacent to the piston rod and a rear cavity away from the piston rod, and a piston check valve provided on the piston part; an oil storage cylinder having an oil storage cavity, the oil storage cavity having a first side in communication with the front cavity and a second side in communication with the rear cavity, a damping valve provided between the first side and the front cavity, and an oil storage check valve provided between the second side and the rear cavity; and a filter assembly provided in the oil storage cavity and between the first side and the second side.

[0008] In some embodiments, the filter assembly comprises a bracket, a gasket and a filter screen provided in sequence along the axial direction of the oil storage cavity.

[0009] In some embodiments, the filter screen is made of stainless steel, the inner wall of the oil storage cylinder is provided with at least three positioning protrusions, and the outer peripheral edge of the filter screen is clamped in the positioning protrusions to limit the axial sliding of the filter screen along the oil storage cavity.

[0010] In some embodiments, the bracket is provided with a plurality of oil passing holes penetrating through the thickness direction thereof, the inner peripheral surface and the outer peripheral surface of the bracket are respectively provided with rectangular ring grooves, and O-shaped sealing rings are respectively embedded in the rectangular ring grooves and abut against and seal the inner wall of the oil storage cylinder and the outer wall of the pressure cylinder.

[0011] In some embodiments, the gasket is made of metal material and clamped between the bracket and the filter screen to form a closed buffer cavity between the bracket and the filter screen.

[0012] In some embodiments, the filter hole diameter of the filter screen is 0.3 mm.

[0013] In some embodiments, the three positioning protrusions are distributed at equal angles along the circumferential direction of the inner wall of the oil storage cylinder.

[0014] In some embodiments, the valve hole diameter of the damping valve ranges from 0.3 mm to 1.0 mm.

[0015] In some embodiments, the filter screen is a double-layer stainless steel screen structure, and the two layers of filter screens are fixedly connected with each other.

[0016] In some embodiments, the filter screen is detachably connected with the inner wall of the oil storage cylinder, the lower end of the filter screen is provided with a plurality of positioning grooves, and the positioning grooves are matched with the positioning protrusions.

[0017] Through the oil pressure shock absorber provided above, the filter assembly provided between the first side and the second side of the oil storage cavity can reduce the probability of failure of the damping system caused by oil leakage or unfiltered impurities. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other objects, features and advantages of the disclosed example embodiments will become more apparent from the following detailed description read in conjunction with the accompanying drawings, in which: Figure 1 An exemplary sectional view of an oil hydraulic shock absorber is shown illustrating some embodiments of the present disclosure; Figure 2 An exemplary front view of a bracket of an oil hydraulic shock absorber is shown illustrating some embodiments of the present disclosure; Figure 3 An exemplary front view of a screen of an oil hydraulic shock absorber is shown illustrating some embodiments of the present disclosure. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present disclosure will be apparently and completely described below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of, rather than all of, the embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present disclosure.

[0020] It should be understood that the terms "comprise" and "comprising" used in the specification and claims of the present disclosure indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0021] It should also be understood that the terminology used in the specification of the present disclosure is merely for the purpose of describing particular embodiments and is not intended to limit the present disclosure. As used in the specification and claims of the present disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "and / or" as used in the specification and claims of the present disclosure, mean any one or more of the associated listed items, as well as combinations of any of the associated listed items.

[0022] As used in the specification and claims, the term "if' can be interpreted as meaning "when" or "once" or "in response to a determination" or "in response to a detection" depending on the context. Similarly, the phrase "if determined" or "if detected [the described condition or event]" can be interpreted as meaning "once determined" or "in response to a determination" or "once detected [the described condition or event]" or "in response to a detection [the described condition or event]" depending on the context.

[0023] The oil pressure shock absorber provided by the embodiments of the present disclosure can reduce the probability of failure of the damping system caused by oil leakage or unfiltered impurities by arranging a filter assembly between the first side and the second side of the oil storage cavity.

[0024] The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0025] Referring to Figure 1 , Figure 1 An exemplary cross-sectional view of an oil pressure shock absorber according to some embodiments of the present disclosure is shown. In this embodiment, an oil pressure shock absorber includes a pressure cylinder 10, a piston assembly 20, an oil storage cylinder 30, and a filter assembly 40. The pressure cylinder 10 has a pressure cavity. The piston assembly 20 has a piston portion 21 in sliding fit with the pressure cavity and a piston rod 22 connected to the piston portion 21, the piston portion 21 divides the pressure cavity into a front cavity 118 adjacent to the piston rod 22 and a rear cavity 119 away from the piston rod 22, and a piston check valve 25 is arranged on the piston portion 21. The oil storage cylinder 30 has an oil storage cavity 31, the oil storage cavity 31 has a first side 311 in communication with the front cavity 118 and a second side 312 in communication with the rear cavity 119, and a damping valve 38 is further arranged between the first side 311 and the front cavity 118, and an oil storage check valve 39 is further arranged between the second side 312 and the rear cavity 119. The filter assembly 40 is arranged in the oil storage cavity 31 and between the first side 311 and the second side 312.

[0026] Specifically, the pressure cylinder 10 and the oil storage cylinder 30 are coaxially nested, an annular oil storage cavity 31 is formed between the outer wall of the pressure cylinder 10 and the inner wall of the oil storage cylinder 30, a wear-resistant sealing ring can be arranged on the outer circumferential surface of the piston portion 21 to achieve a precise fit with the inner wall of the pressure cylinder 10, and the piston check valve 25 is fixedly arranged on the piston portion 21 to control the one-way flow of oil in the thickness direction of the piston portion 21. The first side 311 of the oil storage cavity 31 is in communication with the front cavity 118 through an oil passage, the second side 312 is in communication with the rear cavity 119 through an oil passage, and the damping valve 38 and the oil storage check valve 39 are fixedly arranged at the ports of the corresponding oil passages by screw connection or other methods. The first side 311 may, for example, be the upper part of the oil storage cavity 31, and the second side 312 may, for example, be the lower part of the oil storage cavity 31, and the filter assembly 40 is arranged at a position close to the lower part of the oil storage cylinder 30 and is completely immersed in the oil.

[0027] Thus, the precise fit of the piston portion 21 can prevent oil leakage inside the pressure cylinder 10, the fixed connection of the oil passage with the check valve or the damping valve 38 can ensure the stability of the oil passage, and the filter assembly 40 can ensure that the oil can completely flow through the filter assembly 40 during both the extension and compression strokes, thereby reducing the probability of failure of the damping system caused by oil leakage or unfiltered impurities.

[0028] In this embodiment, the filter assembly 40 includes a bracket 41, a gasket 42 and a filter screen 43 arranged in sequence along the axial direction of the oil storage cavity 31. The bracket 41, the gasket 42 and the filter screen 43 are all substantially annular, and their central axes coincide with the central axis of the oil storage cavity 31. They are all arranged on the radial outer side of the pressure cylinder 10. The upper end surface of the gasket 42 is attached to the lower end surface of the bracket 41, and the upper end surface of the filter screen 43 is attached to the lower end surface of the gasket 42. The three are axially compressed and fixed by the positioning structure of the inner wall of the oil storage cylinder 30. Thus, a coaxial and sequentially assembled filter structure is formed between the three, which allows the oil to flow through each component in the axial direction, avoiding turbulence in the oil flow process due to assembly deviation. At the same time, the sequentially attached connection mode can ensure the integrity of the filter path, prevent internal leakage of oil through the gap between the components, and thus improve the filtering effect.

[0029] Further or alternatively, with reference to Figures 1 to 3 , Figure 2 An exemplary front view of a bracket of an oil hydraulic shock absorber is shown, Figure 3 An exemplary front view of a filter screen of an oil hydraulic shock absorber is shown. The filter screen 43 is made of stainless steel, and the inner wall of the oil storage cylinder 30 is provided with at least three positioning protrusions 37. The outer peripheral edge of the filter screen 43 is clamped to the positioning protrusions 37 to limit the axial sliding of the filter screen 43 along the oil storage cavity 31. The positioning protrusions 37 are arc-shaped protrusions integrally formed on the inner wall of the oil storage cylinder 30 by stamping process, and the height of the protrusions can be set to 0.8-1mm. The outer peripheral edge of the filter screen 43 can be provided with a clamping structure adapted to the positioning protrusions 37, and the depth of the clamping structure can be set to be consistent with the height of the positioning protrusions 37. After the filter screen 43 is clamped to the inner wall of the oil storage cylinder 30 by means of the clamping structure, the end surface of the filter screen 43 is perpendicular to the inner wall of the oil storage cylinder 30. The stainless steel material has excellent oil resistance and wear resistance, which can avoid corrosion or wear caused by long-term contact with oil. The integrally formed positioning protrusions 37 have high structural strength and accurate positioning. The clamping adaptation of the filter screen 43 can effectively limit the axial displacement of the filter screen 43, prevent the filter screen 43 from sliding out of position due to oil impact during the operation of the shock absorber, and ensure that the filter screen 43 always stays in the preset filtering position, maintaining a stable filtering area. By making the end surface of the filter screen 43 perpendicular to the inner wall of the oil storage cylinder 30 and making the outer diameter of the filter screen 43 fit the size of the inner wall of the oil storage cylinder 30, the assembly gap between the filter screen 43 and the oil storage cylinder 30 can be further reduced, and the effective filtering area during oil filtration can be improved.

[0030] Further or alternatively, the support 41 is provided with a plurality of oil passing holes 415 penetrating through the thickness direction thereof, and the inner and outer circumferential surfaces of the support 41 are respectively provided with rectangular ring grooves, and O-shaped sealing rings 417 are respectively embedded in the rectangular ring grooves, and the O-shaped sealing rings 417 are respectively in abutting sealing with the inner wall of the oil storage cylinder 30 and the outer wall of the pressure cylinder 10. The oil passing holes 415 are uniformly distributed along the circumferential direction of the support 41. By uniformly distributing a plurality of oil passing holes 415 along the circumferential direction of the support 41, the oil can be uniformly distributed and passed through the support 41, thereby reducing the pressure loss caused by the excessively high local flow rate. The O-shaped sealing rings 417 installed in the rectangular ring grooves of the inner and outer circumferential surfaces of the support 41 can realize the gapless sealing between the support 41 and the oil storage cylinder 30 and the pressure cylinder 10, prevent the oil from directly flowing through the gap between the support 41 and the cylinder body without being filtered, and make the oil entering the oil storage cavity 31 all filtered by the filter screen 43.

[0031] In addition, the gasket 42 is made of a metal material, the gasket 42 is clamped between the support 41 and the filter screen 43, and a closed buffer cavity is formed between the support 41 and the filter screen 43. The gasket 42 can be made of any metal material, and the outer diameter of the gasket 42 is the same as the outer diameter of the support 41, so that the gasket 42 and the support 41 can be stably supported on the inner wall of the oil storage cavity 31. The closed buffer cavity can temporarily store oil and impurities, avoid the filter screen 43 being blocked due to the instantaneous accumulation of impurities, and make the oil flow at a buffer speed in the cavity, so that the impurities have sufficient time to be intercepted by the filter screen 43, thereby significantly improving the filtering efficiency.

[0032] In this embodiment, the filter screen 43 has a filter hole diameter of 0.3 mm. The filter holes of the filter screen 43 can be formed by laser drilling or other processes, or can be formed by interlacing metal wires. In the case of using laser drilling or other processes, the hole diameter can be accurately machined, the position distribution is uniform, and there is no defect of excessive hole diameter deviation. The precise hole diameter is matched with the hole of the damping valve 38, so as to accurately intercept various impurities larger than 0.3 mm in the oil, avoid the impurities entering the damping valve 38 to cause the valve hole to be blocked, ensure the stable throttling effect of the damping valve 38, and further ensure that the damping force of the shock absorber is always in the normal working range.

[0033] At the same time, when the oil contains air bubbles, the air bubbles will be squeezed and broken when flowing through the filter screen 43 with a hole diameter of 0.3 mm, the oil passes through the filter screen, and the air is left outside, avoiding the air bubbles entering the second side 312 of the oil storage cylinder and further entering the rear cavity 119 of the pressure cylinder to affect the damping force.

[0034] In addition, the filter screen 43 with a hole diameter of 0.3 mm will not cause the oil to flow through the throttle to cause the internal pressure of the oil storage cylinder to rise, thereby avoiding the influence on the damping force.

[0035] Further or alternatively, the three positioning protrusions 37 are distributed at equal angles along the inner wall of the oil storage cylinder 30. The three positioning protrusions 37 can be arranged at an interval of 120° from each other, i.e., at 0°, 120° and 240° positions along the inner wall of the oil storage cylinder 30. The arc profile of the protrusions can be designed to match the curvature of the outer peripheral edge profile of the filter screen 43, and the force receiving surface area of each protrusion is the same. The equal angle distribution design makes the positioning force acting on the filter screen 43 in the axial direction uniform and symmetrical, avoiding excessive local stress that may cause the filter screen 43 to deform or shift, while ensuring that the gap between the filter screen 43 and the inner wall of the oil storage cylinder 30 is uniform, and the oil can enter the filtering area uniformly in the axial direction, preventing excessive local filtering load due to the deflection of the filter screen 43, and improving the overall filtering effect and service life of the filter screen 43.

[0036] In addition, in this embodiment, the valve hole diameter of the damping valve 38 ranges from 0.3 mm to 1.0 mm. The valve hole diameter of the damping valve 38 can be selected within the range of 0.3-1.0 mm according to the rated damping force requirement of the shock absorber, and the valve hole and the valve core of the damping valve 38 are in clearance fit. This diameter range design can meet the damping force adjustment requirements of the shock absorber under different working conditions, and the precise fit of the valve hole and the valve core can ensure the stability of the throttling effect. In the case where the filter hole diameter of the filter screen 43 is 0.3 mm, the valve hole diameter in combination with the precise filtering of the filter screen 43 can effectively avoid the problem of sudden change of damping force caused by blockage of the valve hole by impurities. Further or alternatively, the filter screen 43 is a double-layer stainless steel screen structure, and the two layers of filter screens 43 are fixedly connected to each other. The materials of the two layers of filter screens 43 can be 304 stainless steel, and the screen holes are aligned. The two layers of filter screens 43 are fixed to each other by circumferential spot welding or the like. The double-layer filter screen 43 structure can improve the impurity interception rate by more than one time compared with the single-layer filter screen 43, effectively intercepting fine impurities, while the double-layer fixed connection enhances the overall structural strength of the filter screen 43, avoiding damage to the filter screen 43 caused by oil impact or impurity accumulation, ensuring the long-term reliability of the filtering function, and reducing the maintenance frequency of the shock absorber.

[0037] In addition, in some embodiments not shown, the filter screen 43 is detachably connected with the inner wall of the oil storage cylinder 30, the lower end of the filter screen 43 is provided with a plurality of positioning grooves matched with the positioning protrusions 37. The number of the positioning grooves is consistent with the positioning protrusions 37, the cross-sectional shape of the grooves is arc-shaped matched with the positioning protrusions 37, the filter screen 43 is assembled with the positioning protrusions 37 in an axial clamping manner, and after clamping, the filter screen 43 cannot rotate relative to the oil storage cylinder 30, and the filter screen 43 can be removed by moving it in the opposite direction when disassembled. The detachable connection structure facilitates cleaning or replacement of the filter screen 43 in the later period, without the need to disassemble the entire shock absorber, thereby reducing the maintenance difficulty and cost. The arc-shaped matching design of the positioning grooves and the positioning protrusions 37 can ensure the positioning accuracy after assembly, and the rotary locking mode can ensure that the filter screen 43 does not loosen during the working process, thereby maintaining the structural stability and filtering effect of the filtering assembly 40.

[0038] The oil pressure shock absorber provided by the embodiments of the present disclosure sets the filtering assembly between the first side and the second side of the oil storage cavity, so that the oil entering the oil storage cylinder passes through the filtering assembly during both the extension stroke and the compression stroke, thereby synchronously purifying the oil in the shock absorber during the working process of the shock absorber, and reducing the probability of failure of the damping system caused by oil leakage or unfiltered impurities. At the same time, the filtering assembly is arranged at the lower part of the oil storage cylinder and is completely immersed in the oil, thereby avoiding the oil directly impacting the filtering assembly to generate bubbles. The filtering assembly plays a role in oil-gas separation, and the bubbles in the oil are adsorbed and broken when the oil passes through the filtering assembly, thereby avoiding the risk of bubbles entering the lower cavity of the oil storage cylinder and the pressure cylinder.

[0039] Further, in some embodiments of the present disclosure, the filtering device completely divides the oil storage cylinder into two parts through the sealing of the O-ring, and all the oil must pass through the filter screen to enter the oil storage cylinder, thereby improving the filtering efficiency and reliability. At the same time, the pore size of 0.3 mm can filter impurities larger than the pore size of the damping hole, on the other hand, it also makes the oil flow relatively unobstructed and does not affect the pressure distribution inside the oil storage cylinder. In addition, the filter screen type can adsorb and break the bubbles in the oil at the filter screen, thereby preventing the bubbles from entering the pressure cylinder to affect the damping force, and has a certain gas-liquid separation effect. At the same time, the filtering device has a compact structure and has little effect on the total volume of the shock absorber, and does not affect the volume of the oil.

[0040] While several embodiments of the disclosure have been shown and described herein, it is to be understood that the embodiments are merely exemplary. Numerous changes, substitutions and equivalents can occur to those skilled in the art without departing from the spirit and scope of the disclosure. It should be understood that various alternatives to the embodiments of the disclosure described herein can be employed in practicing the disclosure. It is intended that the following claims define the scope of the disclosure and that methods equivalent to those claims recited herein are within the scope and spirit of the disclosure. Therefore, the disclosure is not limited to the specific embodiments described herein, but only by the claims.

Claims

1. A hydraulic shock absorber, characterized in that, include: Pressure cylinder (10) having a pressure chamber (11); The piston assembly (20) has a piston portion (21) that slides with the pressure chamber (11) and a piston rod (22) connected to the piston portion (21). The piston portion (21) divides the pressure chamber (11) into a front chamber (118) adjacent to the piston rod (22) and a rear chamber (119) away from the piston rod (22). A piston check valve (25) is provided on the piston portion (21). An oil reservoir (30) has an oil reservoir (31) having a first side (311) communicating with the front cavity (118) and a second side (312) communicating with the rear cavity (119). A damping valve (38) is provided between the first side (311) and the front cavity (118), and an oil reservoir check valve (39) is provided between the second side (312) and the rear cavity (119). A filter assembly (40) is disposed in the oil storage chamber (31) and located between the first side (311) and the second side (312).

2. The hydraulic shock absorber according to claim 1, characterized in that, The filter assembly (40) includes a bracket (41), a washer (42), and a filter screen (43) arranged sequentially along the axial direction of the oil storage chamber (31).

3. The hydraulic shock absorber according to claim 2, characterized in that, The filter screen (43) is made of stainless steel. The inner wall of the oil storage cylinder (30) is provided with at least three positioning protrusions (37). The outer peripheral edge of the filter screen (43) is engaged with the positioning protrusions (37) to restrict the filter screen (43) from sliding axially along the oil storage cavity (31).

4. The hydraulic shock absorber according to claim 2, characterized in that, The bracket (41) is provided with several oil passage holes (415) that pass through its thickness direction. The inner and outer circumferential surfaces of the bracket (41) are respectively provided with rectangular annular grooves. O-ring seals (417) are respectively embedded in the rectangular annular grooves. The O-ring seals (417) abut against and seal with the inner wall of the oil storage cylinder (30) and the outer wall of the pressure cylinder (10).

5. The hydraulic shock absorber according to claim 2, characterized in that, The washer (42) is made of metal material and is sandwiched between the support (41) and the filter (43) to form a closed buffer cavity between the support (41) and the filter (43).

6. The hydraulic shock absorber according to claim 2, characterized in that, The filter screen (43) has a filter hole (435) diameter of 0.3 mm.

7. The hydraulic shock absorber according to claim 3, characterized in that, The three positioning protrusions (37) are distributed at equal angles along the inner wall of the oil reservoir (30).

8. The hydraulic shock absorber according to any one of claims 1 to 7, characterized in that, The valve orifice diameter of the damping valve (38) ranges from 0.3 mm to 1.0 mm.

9. The hydraulic shock absorber according to any one of claims 2 to 7, characterized in that, The filter screen (43) is a double-layer stainless steel mesh structure, and the two layers of filter screen (43) are fixedly connected to each other.

10. The hydraulic shock absorber according to any one of claims 2 to 7, characterized in that, The filter screen (43) is detachably connected to the inner wall of the oil storage cylinder (30). The lower end of the filter screen (43) is provided with multiple positioning grooves, which cooperate with the positioning protrusion (37).

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