A two-way damping rear shock absorber

Abstract

The present application discloses a two-way damping rear shock absorber, which includes a working cylinder block, a first piston rod, a second piston rod, an inner piston and an outer piston; the working cylinder block includes a cylindrical inner cylinder block and a cylindrical outer cylinder block coaxially sleeved outside the inner cylinder block; the end of the first piston rod is installed with an inner piston, the side wall of the inner piston abuts against the inner wall of the inner cylinder block, and a first working cylinder is formed inside the inner cylinder block; the end of the second piston rod is connected with an annular outer piston, the inner side wall of the outer piston abuts against the outer wall of the inner cylinder block, the outer side wall of the outer piston abuts against the inner wall of the outer cylinder block, and a second working cylinder is formed between the outer cylinder block and the inner cylinder block; the first working cylinder and the second working cylinder are both filled with hydraulic oil; the upper end of the side wall of the inner cylinder block is provided with a first valve group for communicating the first working cylinder and the second working cylinder; the lower end of the side wall of the inner cylinder block is provided with a second valve group for communicating the first working cylinder and the second working cylinder. The present application solves the problem of poor shock absorption effect caused by the short stroke of the shock absorber in the prior art.

Description

Technical Field

[0001] This application belongs to the technical field of shock absorbers, and particularly relates to a two-way damping rear shock absorber. Background Art

[0002] Shock absorbers are used to suppress the oscillations when the spring rebounds after absorbing shock and the impacts from the road surface. They are widely used in automobiles to accelerate the attenuation of the vibration between the vehicle frame and the body, so as to improve the ride comfort of the vehicle. When passing through an uneven road surface, although the shock-absorbing spring can filter the road vibrations, the spring itself will still have reciprocating movements, and the shock absorber is used to suppress this spring bounce. In the suspension system, due to the shock generated by the elastic element, in order to improve the ride comfort of the vehicle, a shock absorber is installed in parallel with the elastic element in the suspension. To attenuate the vibration, most shock absorbers used in the vehicle suspension system are hydraulic shock absorbers. Its working principle is that when there is relative movement due to the vibration between the vehicle frame (or body) and the axle, the piston in the shock absorber moves up and down, and the hydraulic fluid in the shock absorber cavity repeatedly flows from one cavity through different pores into another cavity. At this time, the friction between the pore wall and the hydraulic fluid and the internal friction between the hydraulic fluid molecules form a damping force on the vibration, converting the vehicle vibration energy into hydraulic fluid heat energy, which is then absorbed by the shock absorber and dissipated into the atmosphere. When the cross-sectional area of the hydraulic fluid passage and other factors remain unchanged, the damping force increases or decreases with the relative movement speed between the vehicle frame and the axle (or wheel), and is related to the viscosity of the hydraulic fluid. The current shock absorbers have a short stroke. When some vehicles encounter a road surface with large bumps, the shock absorption effect of the shock absorber is limited, resulting in problems such as poor shock absorption effect, and thus it is easy to cause discomfort to passengers. Summary of the Invention

[0003] By providing a two-way damping rear shock absorber in the embodiments of this application, the problem of poor shock absorption effect caused by the short stroke of the shock absorber in the prior art is solved.

[0004] An embodiment of the present invention provides a two-way damping rear shock absorber, including a working cylinder block, a first piston rod, a second piston rod, an inner piston, and an outer piston;

[0005] The working cylinder block includes a cylindrical inner cylinder block and a cylindrical outer cylinder block coaxially sleeved outside the inner cylinder block;

[0006] The inner piston is installed at the end of the first piston rod. The first piston rod extends into the inner cylinder block from the top wall of the working cylinder block. The side wall of the inner piston abuts against the inner wall of the inner cylinder block, and a first working cylinder is formed inside the inner cylinder block;

[0007] The end of the second piston rod is connected with the annular outer piston. The second piston rod extends into the outer cylinder from the bottom wall of the working cylinder block. The inner side wall of the outer piston abuts against the outer wall of the inner cylinder, and the outer side wall of the outer piston abuts against the inner wall of the outer cylinder. A second working cylinder is formed between the outer cylinder and the inner cylinder. The first working cylinder and the second working cylinder are both filled with hydraulic oil.

[0008] At the upper end of the side wall of the inner cylinder, a first valve group for communicating the first working cylinder and the second working cylinder is provided. The first valve group includes a first circulation valve, a first extension valve, a first compression valve, and a first compensation valve.

[0009] At the lower end of the side wall of the inner cylinder, a second valve group for communicating the first working cylinder and the second working cylinder is provided. The second valve group includes a second circulation valve, a second extension valve, a second compression valve, and a second compensation valve.

[0010] In a possible implementation manner, the upper end of the inner cylinder is connected to the top wall of the outer cylinder, and the lower end of the inner cylinder is connected to the bottom wall of the outer cylinder.

[0011] In a possible implementation manner, a first oil seal is provided at the position where the first piston rod passes through the top wall of the working cylinder block, and a second oil seal is provided at the position where the second piston rod passes through the bottom wall of the working cylinder block.

[0012] In a possible implementation manner, inner limiting rings for blocking the inner piston are provided at both the upper end and the lower end of the inner wall of the inner cylinder.

[0013] First outer limiting rings for blocking the outer piston are provided at both the upper end and the lower end of the outer wall of the inner cylinder. Second outer limiting rings for blocking the outer piston are provided at both the upper end and the lower end of the inner wall of the outer cylinder.

[0014] The inner limiting rings, the first outer limiting rings, and the second outer limiting rings are arranged at the same height of the working cylinder block.

[0015] In a possible implementation manner, the first valve group is located at the side wall between the top of the inner cylinder and the inner limiting ring at the upper end of the inner cylinder.

[0016] The second valve group is located at the side wall between the bottom of the inner cylinder and the inner limiting ring at the lower end of the inner cylinder.

[0017] In a possible implementation manner, the number of the second piston rods is two, and the two second piston rods are respectively located on both sides of the first working cylinder.

[0018] In a possible implementation, the first piston rod and the inner piston are connected by a first compression nut, and the second piston rod and the outer piston are connected by a second compression nut.

[0019] In a possible implementation, it further includes a first dust cover and a second dust cover;

[0020] The first dust cover is sleeved on the upper end of the working cylinder block. The first piston rod is connected to the top wall of the first dust cover, and an upper suspension ring is provided at the upper end of the first dust cover;

[0021] The second dust cover is sleeved on the lower end of the first dust cover. The second piston rod is connected to the bottom wall of the second dust cover, a lower suspension ring is provided at the lower end of the second dust cover, and a sealing ring is provided at the end of the inner wall of the second dust cover.

[0022] In a possible implementation, a first airbag is provided at the lower end of the inner piston, and a second airbag is provided at the upper end of the outer piston. The second airbag is of an annular structure.

[0023] In a possible implementation, both the first airbag and the second airbag are filled with nitrogen.

[0024] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0025] The embodiments of the present invention provide a two-way damping rear shock absorber. When the shock absorber is installed on the wheel of a vehicle, when the vehicle encounters bumps or vibrations, the shock absorber generates a damping force on the spring, thereby suppressing the oscillation when the spring rebounds after absorbing shock and the impact from the road surface; the shock absorber of the present invention realizes the function of two-way damping. By setting the first piston rod and the second piston rod, and the corresponding first working cylinder and second working cylinder, when the vehicle encounters large bumps or vibrations, the first piston rod and the second piston rod can extend simultaneously and generate a certain damping force, thereby effectively damping the vehicle and greatly improving the riding comfort of passengers. Therefore, the shock absorber of the present invention can meet the shock absorption requirements of existing vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments of the present invention. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of the two-way damping rear shock absorber provided by the embodiments of the present invention.

[0028] Icons: 1 - First piston rod; 2 - Second piston rod; 3 - Inner piston; 4 - Outer piston; 5 - Inner cylinder block; 6 - Outer cylinder block; 7 - First working cylinder; 8 - Second working cylinder; 9 - First oil seal; 10 - Second oil seal; 11 - Inner limit ring; 12 - First outer limit ring; 13 - First dust cover; 14 - Second dust cover; 15 - Upper hanging ring; 16 - First airbag; 17 - Second airbag; 18 - First valve group; 19 - Second valve group; 20 - Working cylinder block; 21 - Lower hanging ring. Detailed implementation mode

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that in the embodiments of the present invention, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. The terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0031] As Figure 1 shown, the two-way damping rear shock absorber provided by the embodiment of the present invention includes a working cylinder block 20, a first piston rod 1, a second piston rod 2, an inner piston 3, and an outer piston 4.

[0032] The working cylinder block 20 includes a cylindrical inner cylinder block 5 and a cylindrical outer cylinder block 6 coaxially sleeved outside the inner cylinder block 5.

[0033] The end of the first piston rod 1 is installed with an inner piston 3. The first piston rod 1 extends into the inner cylinder block 5 from the top wall of the working cylinder block 20. The side wall of the inner piston 3 abuts against the inner wall of the inner cylinder block 5, and a first working cylinder 7 is formed inside the inner cylinder block 5.

[0034] The end of the second piston rod 2 is connected with an annular outer piston 4. The second piston rod 2 extends into the outer cylinder 6 from the bottom wall of the working cylinder block 20. The inner side wall of the outer piston 4 abuts against the outer wall of the inner cylinder 5, and the outer side wall of the outer piston 4 abuts against the inner wall of the outer cylinder 6. A second working cylinder 8 is formed between the outer cylinder 6 and the inner cylinder 5; both the first working cylinder 7 and the second working cylinder 8 are filled with hydraulic oil.

[0035] At the upper end of the side wall of the inner cylinder 5, there is a first valve group 18 for communicating the first working cylinder 7 and the second working cylinder 8. The first valve group 18 includes a first circulation valve, a first extension valve, a first compression valve and a first compensation valve; the first circulation valve, the first extension valve, the first compression valve and the first compensation valve can be arranged at the same height, thereby being able to shorten the length of the shock absorber of the present invention. In this embodiment, the first circulation valve, the first extension valve, the first compression valve and the first compensation valve are divided into two groups and are respectively arranged on the left and right side walls of the inner cylinder 5.

[0036] At the lower end of the side wall of the inner cylinder 5, there is a second valve group 19 for communicating the first working cylinder 7 and the second working cylinder 8. The second valve group 19 includes a second circulation valve, a second extension valve, a second compression valve and a second compensation valve. The second circulation valve, the second extension valve, the second compression valve and the second compensation valve can be arranged at the same height. In this embodiment, the second circulation valve, the second extension valve, the second compression valve and the second compensation valve are divided into two groups and are respectively arranged on the left and right side walls of the inner cylinder 5.

[0037] The valves of the first valve group 18 and the second valve group 19 are independently arranged and will not affect each other during operation.

[0038] It should be noted that the hydraulic oil in the inner cylinder 5 and the outer cylinder 6 is not filled completely, leaving a certain amount of space, thereby facilitating the flow of the hydraulic oil and realizing the damping function of the shock absorber.

[0039] The springs arranged in the first circulation valve, the first compensation valve, the second circulation valve and the second compensation valve are relatively soft. Therefore, when the oil pressure in the shock absorber is relatively low, that is, when the shock absorber is subjected to a relatively small pressure or tensile force, the first circulation valve, the first compensation valve, the second circulation valve or the second compensation valve opens for the flow of the hydraulic oil, thereby generating a relatively small damping force when the shock absorber extends or contracts. The springs arranged in the first extension valve, the first compression valve, the second extension valve and the second compression valve are relatively hard. Only when the oil pressure in the shock absorber is relatively high, that is, when the shock absorber is subjected to a relatively large pressure or tensile force, the first extension valve, the first compression valve, the second extension valve or the second compression valve will open for the flow of the hydraulic oil.

[0040] The shock absorber in the embodiment of the present invention needs to cooperate with a spring to achieve a buffering effect. After the shock absorber is installed on the wheel of a vehicle, when the vehicle encounters bumps or vibrations, the shock absorber generates a damping force on the spring, thereby suppressing the oscillation when the spring rebounds after absorbing shock and the impact from the road surface.

[0041] The specific working process of the shock absorber is as follows: When the shock absorber is compressed by force, the first piston rod 1 moves downward and the second piston rod 2 moves upward. The downward movement of the first piston rod 1 causes the chamber volume in the upper part of the first working cylinder 7 to increase and the chamber volume in the lower part of the first working cylinder 7 to decrease, and the oil pressure in the lower chamber is higher than that in the upper chamber. The upward movement of the second piston rod 2 causes the chamber volume in the upper part of the second working cylinder 8 to decrease and the chamber volume in the lower part of the second working cylinder 8 to increase, and the oil pressure in the upper chamber is higher than that in the lower chamber. As a result, the oil in the lower chamber of the first working cylinder 7 flows into the lower chamber of the second working cylinder 8 through the second flow valve, and the oil in the upper chamber of the second working cylinder 8 flows into the upper chamber of the first working cylinder 7 through the first flow valve. Since the first piston rod 1 extends into and occupies part of the chamber volume in the upper part of the first working cylinder 7, and the second piston rod 2 extends into and occupies part of the chamber volume in the lower part of the second working cylinder 8, the oil cannot all flow to adapt to the volume occupied by the first piston rod 1 and the second piston rod 2. At this time, when the first piston rod 1 and the second piston rod 2 continue to move, the damping force increases, and the oil in the lower chamber of the first working cylinder 7 flows into the lower chamber of the second working cylinder 8 through the second compression valve, and the oil in the upper chamber of the second working cylinder 8 flows into the upper chamber of the first working cylinder 7 through the first compression valve. The flow areas of these valves are small, so a certain damping force is generated.

[0042] When the shock absorber is stretched by force, the first piston rod 1 moves upward and the second piston rod 2 moves downward. The upward movement of the first piston rod 1 causes the chamber volume in the upper part of the first working cylinder 7 to decrease and the chamber volume in the lower part of the first working cylinder 7 to increase, and the oil pressure in the lower chamber is less than that in the upper chamber. The downward movement of the second piston rod 2 causes the chamber volume in the upper part of the second working cylinder 8 to increase and the chamber volume in the lower part of the second working cylinder 8 to decrease, and the oil pressure in the upper chamber is less than that in the lower chamber. As a result, the oil in the lower chamber of the second working cylinder 8 flows into the lower chamber of the first working cylinder 7 through the second extension valve, and the oil in the upper chamber of the second working cylinder 8 flows into the upper chamber of the first working cylinder 7 through the first extension valve. Since the upward movement of the first piston rod 1 creates a certain degree of vacuum in the lower chamber of the first working cylinder 7, and the downward movement of the second piston rod 2 creates a certain degree of vacuum in the upper chamber of the second working cylinder ⑧, the oil in the lower chamber of the second working cylinder 8 flows into the lower chamber of the first working cylinder 7 through the second compensation valve, and the oil in the upper chamber of the first working cylinder 7 flows into the upper chamber of the second working cylinder 8 through the first compensation valve. The oil passes through these valves and thereby generates a certain damping force.

[0043] The two-way damping rear shock absorber provided by the embodiment of the present invention omits the structure of the oil storage chamber compared with the existing shock absorber. Therefore, under the condition of the first working cylinder 7 and the second working cylinder 8 of the same specification, the cross-sectional area of the channels of the valves in the first valve group 18 and the second valve group 19 of the present invention should be smaller, so as to ensure that the shock absorber can generate the same damping force. This shock absorber is suitable for vehicles with small installation space and large shock absorption amplitude. By setting two groups of working cylinders, it can meet the shock absorption requirements of existing vehicles with a large amplitude. Since the present invention omits the structure of the oil storage chamber, and the upper chambers of the first working cylinder 7 and the second working cylinder 8 are connected by valves, and the lower chambers of the first working cylinder 7 and the second working cylinder 8 are connected by valves, the present invention can also cancel the first extension valve, the first compression valve, the second extension valve and the second compression valve with a relatively hard spring, and only retain the first flow valve, the first compensation valve, the second flow valve and the second compensation valve. By selecting the first flow valve, the first compensation valve, the second flow valve and the second compensation valve suitable for the shock absorber structure of the embodiment of the present invention, the oil can generate a set damping force when passing through the first flow valve, the first compensation valve, the second flow valve and the second compensation valve, so as to meet the shock absorption requirements of existing vehicles. The first extension valve, the first compression valve, the second extension valve and the second compression valve with a relatively hard spring adopted in the embodiment of the present invention can make the working state of the shock absorber more stable.

[0044] The shock absorber provided by the embodiment of the present invention realizes the function of two-way damping. By setting the first piston rod 1 and the second piston rod 2, and the corresponding first working cylinder 7 and the second working cylinder 8, when the vehicle encounters large bumps or vibrations, the first piston rod 1 and the second piston rod 2 can extend or shorten simultaneously, and generate a certain damping force, thereby effectively damping the vehicle and greatly improving the riding comfort of passengers. Therefore, the shock absorber of the present invention can meet the shock absorption requirements of existing vehicles.

[0045] In this embodiment, the upper end of the inner cylinder body 5 is connected to the top wall of the outer cylinder body 6, and the lower end of the inner cylinder body 5 is connected to the bottom wall of the outer cylinder body 6. Furthermore, the running reliability of the inner cylinder body 5 and the outer cylinder body 6 can be ensured.

[0046] In this embodiment, a first oil seal 9 is provided at the position where the first piston rod 1 passes through the top wall of the working cylinder body 20, and a second oil seal 10 is provided at the position where the second piston rod 2 passes through the bottom wall of the working cylinder body 20.

[0047] It should be noted that the first oil seal 9 and the second oil seal 10 can prevent oil leakage and ensure the working pressure in the first working cylinder 7 and the second working cylinder 8. The oil seal seals through lubricating oil. It is a mechanical component used to seal grease. It isolates the components that need lubrication in the transmission components from the output components, so as to prevent the leakage of lubricating oil. The first oil seal 9 and the second oil seal 10 of the present invention both adopt dynamic seals to better achieve reciprocating motion. The first oil seal 9 and the second oil seal 10 of the present invention are made of nitrile rubber material. Nitrile rubber has good heat resistance and wear resistance, and is resistant to various lubricating oils, greases, oil-gas mixtures, etc. The applicable temperature is -30 to 120 degrees Celsius, and its performance is stable in gasoline and mineral oils with a low aniline point.

[0048] In this embodiment, inner limiting rings 11 for blocking the inner piston 3 are provided at both the upper end and the lower end of the inner wall of the inner cylinder body 5.

[0049] First outer limiting rings 12 for blocking the outer piston 4 are provided at both the upper end and the lower end of the outer wall of the inner cylinder body 5; second outer limiting rings for blocking the outer piston 4 are provided at both the upper end and the lower end of the inner wall of the outer cylinder body 6.

[0050] The inner limiting rings 11, the first outer limiting rings 12 and the second outer limiting rings are arranged at the same height of the working cylinder body 20.

[0051] In this embodiment, the first valve group 18 is located at the side wall between the top of the inner cylinder body 5 and the inner limiting ring 11 at the upper end of the inner cylinder body 5; the second valve group 19 is located at the side wall between the bottom of the inner cylinder body 5 and the inner limiting ring 11 at the lower end of the inner cylinder body 5.

[0052] It should be noted that the inner limiting ring 11 can limit the movement range of the inner piston 3 and prevent the inner piston 3 from touching the first valve group 18 or the second valve group 19 installed on the side wall of the inner cylinder body 5.

[0053] The first outer limiting ring 12 and the second outer limiting ring can limit the movement range of the outer piston 4 and prevent the outer piston 4 from touching the first valve group 18 or the second valve group 19 installed on the side wall of the inner cylinder body 5. At the same time, the setting of the first outer limiting ring 12 and the second outer limiting ring can improve the running reliability of the outer piston 4 when the shock absorber absorbs shock.

[0054] In this embodiment, the number of the second piston rods 2 is two, and the two second piston rods 2 are respectively located on both sides of the first working cylinder 7.

[0055] It should be noted that the two second piston rods 2 are symmetrically arranged on both sides of the first working cylinder 7. The setting of the two second piston rods 2 can make the movement of the outer piston 4 more stable and prevent problems such as tilting of the outer piston 4.

[0056] In this embodiment, the first piston rod 1 and the inner piston 3 are connected by a first compression nut, and the second piston rod 2 and the outer piston 4 are connected by a second compression nut.

[0057] It should be noted that the threaded section provided at the end of the first piston rod 1 passes through the hole in the center of the inner piston 3 and is then connected to the first compression nut, and the first compression nut is arranged in the groove provided on the inner piston 3.

[0058] The working principle of the first compression nut and the second compression nut is to use the friction between the compression nut and the bolt for self-locking. The present invention takes anti-loosening measures at the connection of the piston rod to ensure the reliability of the nut locking. Therefore, when fixing the inner piston 3 and the outer piston 4 through the first compression nut and the second compression nut, the reliability is higher and it is not easy to loosen.

[0059] In this embodiment, it further includes a first dust cover 13 and a second dust cover 14; the first dust cover 13 is sleeved on the upper end of the working cylinder block 20, the first piston rod 1 is connected to the top wall of the first dust cover 13, and the upper end of the first dust cover 13 is provided with an upper suspension ring 15.

[0060] The second dust cover 14 is sleeved on the lower end of the first dust cover 13, the second piston rod 2 is connected to the bottom wall of the second dust cover 14, the lower end of the second dust cover 14 is provided with a lower suspension ring 21, and a sealing ring is provided at the end of the inner wall of the second dust cover 14.

[0061] It should be noted that when the shock absorber works, the first dust cover 13 and the first piston rod 1 move simultaneously, the second dust cover 14 and the second piston rod 2 move simultaneously. The first dust cover 13 and the second dust cover 14 can protect the first piston rod 1 and the second piston rod 2 from damage, prevent dust from entering the working cylinder block 20, and at the same time can also guide the movement trajectories of the first piston rod 1 and the second piston rod 2, improving the stability of the first piston rod 1 and the second piston rod 2 during movement. The sealing ring can further prevent dust from entering the working cylinder block 20.

[0062] In this embodiment, a first airbag 16 is provided at the lower end of the inner piston 3, and a second airbag 17 is provided at the upper end of the outer piston 4. The second airbag 17 is of an annular structure. The first airbag 16 is of a cylindrical structure with an arc-shaped top.

[0063] In this embodiment, both the first airbag 16 and the second airbag 17 are filled with nitrogen.

[0064] It should be noted that the first airbag 16 is arranged at the center of the inner piston 3 and is spaced from the edge of the inner piston 3 to prevent the first airbag 16 from touching the inner limit ring 11; the space at the end of the first working cylinder 7 can accommodate the first airbag 16. The second airbag 17 is arranged at the center of the outer piston 4 and is spaced from both the inner edge and the outer edge of the outer piston 4 to prevent the second airbag 17 from touching the first outer limit ring 12 and the second outer limit ring; the space at the end of the second working cylinder 8 can accommodate the second airbag 17.

[0065] The first airbag 16 or the second airbag 17 can provide a certain damping force when the first piston rod 1 and the second piston rod 2 are in the extreme positions. When the shock absorber leaks oil, shakes violently, or changes its orientation, i.e., is placed horizontally or tilted, the first working cylinder 7 or the second working cylinder 8 may be short of hydraulic fluid. In this case, the internal pressure of the first working cylinder 7 or the second working cylinder 8 lacking hydraulic fluid decreases, and the first airbag 16 or the second airbag 17 expands, enabling the hydraulic fluid to continue to fill the first working cylinder 7 or the second working cylinder 8, thus avoiding the problem that the shock absorber cannot provide damping force when it needs to absorb shock at this time.

[0066] Install the shock absorber provided by the embodiment of the present invention on the vehicle wheel. When the vehicle encounters bumps or vibrations, the shock absorber generates a damping force on the spring, thereby suppressing the oscillation when the spring rebounds after absorbing shock and the impact from the road surface; the shock absorber of the present invention realizes the function of bidirectional damping. By setting the first piston rod and the second piston rod, as well as the corresponding first working cylinder and the second working cylinder, when the vehicle encounters large bumps or vibrations, the first piston rod and the second piston rod can extend simultaneously and generate a certain damping force, thereby effectively damping the vehicle and greatly improving the riding comfort of passengers. Therefore, the shock absorber of the present invention can meet the shock absorption requirements of existing vehicles.

[0067] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. The key points of each embodiment are the differences from other embodiments.

[0068] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application.

Claims

1. A two-way damping rear shock absorber, characterized in that: It includes a working cylinder block (20), a first piston rod (1), a second piston rod (2), an inner piston (3), and an outer piston (4); The working cylinder block (20) includes a cylindrical inner cylinder block (5) and a cylindrical outer cylinder block (6) coaxially sleeved outside the inner cylinder block (5); The inner piston (3) is installed at the end of the first piston rod (1). The first piston rod (1) extends into the inner cylinder block (5) from the top wall of the working cylinder block (20). The side wall of the inner piston (3) abuts against the inner wall of the inner cylinder block (5), and a first working cylinder (7) is formed inside the inner cylinder block (5); The end of the second piston rod (2) is connected with the annular outer piston (4). The second piston rod (2) extends into the outer cylinder block (6) from the bottom wall of the working cylinder block (20). The inner side wall of the outer piston (4) abuts against the outer wall of the inner cylinder block (5), and the outer side wall of the outer piston (4) abuts against the inner wall of the outer cylinder block (6). A second working cylinder (8) is formed between the outer cylinder block (6) and the inner cylinder block (5); The first working cylinder (7) and the second working cylinder (8) are both filled with hydraulic oil; At the upper end of the side wall of the inner cylinder block (5), there is a first valve group (18) for communicating the first working cylinder (7) and the second working cylinder (8). The first valve group (18) includes a first circulation valve, a first extension valve, a first compression valve, and a first compensation valve; At the lower end of the side wall of the inner cylinder block (5), there is a second valve group (19) for communicating the first working cylinder (7) and the second working cylinder (8). The second valve group (19) includes a second circulation valve, a second extension valve, a second compression valve, and a second compensation valve; At the upper end and the lower end of the inner wall of the inner cylinder block (5), there are inner limiting rings (11) for blocking the inner piston (3); The first valve group (18) is located at the side wall between the top of the inner cylinder block (5) and the inner limiting ring (11) at the upper end of the inner cylinder block (5); The second valve group (19) is located at the side wall between the bottom of the inner cylinder block (5) and the inner limiting ring (11) at the lower end of the inner cylinder block (5); The number of the second piston rods (2) is two, and the two second piston rods (2) are respectively located on both sides of the first working cylinder (7).

2. The bi-directional damping rear shock absorber according to claim 1, wherein: The upper end of the inner cylinder block (5) is connected to the top wall of the outer cylinder block (6), and the lower end of the inner cylinder block (5) is connected to the bottom wall of the outer cylinder block (6).

3. The bi-directional damping rear shock absorber according to claim 2, wherein: At the position where the first piston rod (1) passes through the top wall of the working cylinder block (20), there is a first oil seal (9), and at the position where the second piston rod (2) passes through the bottom wall of the working cylinder block (20), there is a second oil seal (10).

4. The two-way damping rear shock absorber according to claim ①, characterized in that: At the upper end and the lower end of the outer wall of the inner cylinder block (5), there are first outer limiting rings (12) for blocking the outer piston (4); At the upper end and the lower end of the inner wall of the outer cylinder block (6), there are second outer limiting rings for blocking the outer piston (4); The inner limit ring (11), the first outer limit ring (12) and the second outer limit ring are arranged at the same height of the working cylinder block (20).

5. The bi-directional damping rear shock absorber according to claim 1, wherein: The first piston rod (1) and the inner piston (3) are connected by a first compression nut, and the second piston rod (2) and the outer piston (4) are connected by a second compression nut.

6. The bi-directional damping rear shock absorber according to claim 1, wherein: It further includes a first dust cover (13) and a second dust cover (14); The first dust cover (13) is sleeved on the upper end of the working cylinder block (20), the first piston rod (1) is connected to the top wall of the first dust cover (13), and a hanging ring (15) is provided at the upper end of the first dust cover (13); The second dust cover (14) is sleeved on the lower end of the first dust cover (13), the second piston rod (2) is connected to the bottom wall of the second dust cover (14), a lower hanging ring (21) is provided at the lower end of the second dust cover (14), and a sealing ring is provided at the end of the inner wall of the second dust cover (14).

7. The bi-directional damping rear shock absorber according to claim 1, wherein: A first airbag (16) is arranged at the lower end of the inner piston (3), a second airbag (17) is arranged at the upper end of the outer piston (4), and the second airbag (17) is of an annular structure.

8. The bi-directional damping rear shock absorber according to claim 7, wherein: Both the first airbag (16) and the second airbag (17) are filled with nitrogen.

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