Variable speed damper

Abstract

The application discloses a variable-speed damper, which comprises a cylinder and a piston, the piston is slidably arranged in the cylinder, the piston divides the inside of the cylinder into a first cavity and a second cavity, the first cavity and the second cavity are arranged in sequence along the depth direction of the cylinder, and the variable-speed damper is characterized in that: a variable flow channel is arranged, the cross-sectional area of the variable flow channel changes, the variable flow channel is arranged on the inner wall of the cylinder, a flow guide space is formed between the inner wall of the variable flow channel and the radial outer surface of the piston, the flow guide space is used for allowing the fluid to flow from the second cavity to the first cavity; a backflow channel is arranged in the piston, the backflow channel is used for connecting the first cavity and the second cavity; and a control member is arranged in the backflow channel, the control member is used for controlling the one-way flow of the fluid from the first cavity to the second cavity. The application can realize different damping forces, has a simple structure, prolongs the service life, and enables the piston to be quickly reset and then perform buffering work again.

Description

Technical Field

[0001] This invention relates to the technical field of dampers, and particularly to a variable speed damper. Background Technology

[0002] Hydraulic dampers are important components used for buffering the opening and closing of hinges. Existing hydraulic dampers include a cylinder, a piston, and a needle. The piston slides inside the cylinder and divides the cylinder into two oil chambers. The piston has an oil passage hole that connects the two oil chambers. The needle is inserted into the oil passage hole and controls the amount of oil passing through it. A sealing ring is provided on the outer periphery of the piston. The piston slides and seals against the inner wall of the cylinder through the sealing ring to prevent fluid from passing through the gap between the inner wall of the cylinder and the outer periphery of the piston.

[0003] The oil needle is equipped with damping parts of different diameters along its length. The oil passage hole is matched with the damping parts of different diameters to control the fluid flow rate of the oil passage hole. The hydraulic damper can achieve different damping forces when buffering.

[0004] However, existing hydraulic dampers have the following drawbacks:

[0005] 1. The contact and friction between the inner wall of the cylinder and the sealing ring can easily damage the sealing ring, affecting the stability of the oil circuit system and causing the damper to fail.

[0006] 2. Hydraulic dampers have a large number of parts, a complex structure, and are difficult to process and manufacture, as well as difficult to assemble, which greatly increases the cost of the damper.

[0007] 3. The piston of the existing hydraulic damper is difficult to reset quickly. Summary of the Invention

[0008] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a variable speed damper capable of achieving different damping forces, with a simple structure, extended service life, and allowing the piston to quickly reset and resume its buffering function.

[0009] A variable speed damper according to a first aspect of the present invention includes a cylinder and a piston, the piston being slidably disposed inside the cylinder, the piston dividing the interior of the cylinder into a first cavity and a second cavity, the first cavity and the second cavity being arranged sequentially along the depth direction of the cylinder, characterized in that it includes: a variable flow channel, the variable flow channel having a varying cross-sectional area, the variable flow channel being disposed on the inner wall of the cylinder, the inner wall of the variable flow channel forming a guide space between the radial outer surface of the piston, the guide space being used to allow fluid to flow from the second cavity to the first cavity; a return flow channel, the return flow channel being disposed inside the piston, the return flow channel being used to connect the first cavity and the second cavity; and a control element, the control element being disposed within the return flow channel, the control element being used to control the unidirectional flow of fluid from the first cavity to the second cavity.

[0010] A variable speed damper according to an embodiment of the present invention has at least the following beneficial effects:

[0011] 1. This invention, by setting up a variable flow channel with a variable cross-section, utilizes the inner wall of the variable flow channel to cooperate with the radial outer surface of the piston to form a flow guiding space. When the piston moves deeper into the cylinder under the action of external force, the flow rate of the fluid passing through the flow guiding space also changes, thereby changing the damping force of the damper. The damper produces a buffering effect, thus eliminating the need for the traditional method of setting an oil needle to achieve damping force, and eliminating the need for the piston to be connected to the cylinder through a sealing ring. This avoids the situation of the sealing ring being damaged by friction during piston movement, and improves the service life of the damper.

[0012] 2. By setting up a return channel and a control component, the piston moves towards the first chamber under force, and the control component controls the return channel to open, so that the fluid flows unidirectionally from the first chamber to the second chamber. The fluid pressure in the first chamber decreases and the fluid pressure in the second chamber increases, which can push the piston to move. Thus, the piston moves and resets quickly, thereby allowing the damper to resume its buffering function.

[0013] 3. Compared with existing dampers, this invention achieves the function of buffering speed changes, has a fast piston reset speed, greatly simplifies the damping structure, reduces the number of parts, makes processing and manufacturing easier, simplifies assembly, and greatly extends service life.

[0014] According to some embodiments of the present invention, the variable flow channel includes an oil guide groove and an oil discharge chamber arranged sequentially along the depth direction of the cylinder body. The oil guide groove is used to guide fluid to flow from the second chamber to the first chamber, and the oil discharge chamber is used to discharge fluid from the second chamber to the first chamber. The flow rate of fluid through the oil guide groove is less than the flow rate of fluid through the oil discharge chamber.

[0015] According to some embodiments of the present invention, the variable flow channel further includes an oil-blocking surface, which is located between the oil guide groove and the oil discharge chamber. The oil-blocking surface matches the radial outer surface of the piston. When the oil-blocking surface cooperates with the piston, the flow rate of fluid passing through the oil-blocking surface is less than the flow rate of fluid passing through the oil guide groove.

[0016] According to some embodiments of the present invention, the oil drain chamber has an expansion section, the cross-sectional area of ​​which gradually increases along the depth direction of the cylinder.

[0017] According to some embodiments of the present invention, the inner wall of the cylinder is provided with a positioning surface, the positioning surface matches the radial outer surface of the piston and is located on the side of the oil discharge chamber away from the oil guide groove, the oil discharge chamber has a connecting section, one side of the connecting section is connected to the expansion section, and the other side of the connecting section is connected to the positioning surface.

[0018] According to some embodiments of the present invention, there is one oil drain chamber, which extends circumferentially along the inner wall of the cylinder; or, there are multiple oil drain chambers, which are distributed circumferentially along the inner wall of the cylinder.

[0019] According to some embodiments of the present invention, the return channel has a narrowing position, and the control element is a ball valve. When the fluid pressure in the first chamber is less than the pressure in the second chamber, the ball valve is in the narrowing position to prevent fluid from flowing from the second chamber to the first chamber. When the fluid pressure in the first chamber is greater than the pressure in the second chamber, the ball valve leaves the narrowing position to allow fluid to flow from the first chamber to the second chamber.

[0020] According to some embodiments of the present invention, the return channel has a main flow path and a limiting portion disposed within the main flow path. One end of the main flow path is connected to the second cavity, and the other end of the main flow path is connected to the narrowing position. The ball valve is housed inside the main flow path, and the limiting portion is used to restrict the ball valve from disengaging from the main flow path.

[0021] According to some embodiments of the present invention, the main flow path extends along the axial direction of the piston.

[0022] According to some embodiments of the present invention, a spring is also included, the spring being located inside the cylinder body, the spring being used to drive the piston to move toward the first chamber.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of the structure of a variable speed damper according to an embodiment of the present invention;

[0026] Figure 2 for Figure 1 A schematic diagram of the buffer operation of a variable speed damper is shown.

[0027] Figure 3 for Figure 1 The diagram shown is a schematic of the piston reset structure of a variable speed damper;

[0028] Figure 4 for Figure 1 The diagram shows a schematic of the cylinder block of a variable speed damper.

[0029] Figure label:

[0030] 100-Cylinder block, 110-First chamber, 120-Second chamber, 130-Positioning surface, 140-Slot;

[0031] 200-Flow channel, 210-Oil guide groove, 220-Oil discharge chamber, 221-Expansion section, 222-Connecting section, 230-Oil blocking surface;

[0032] 300-Piston, 310-Pushrod, 320-Return oil passage, 321-Main flow path, 322-Narrowing position, 323-Limiting part;

[0033] 400 - Control components;

[0034] 500-Spring;

[0035] 600 - Seals;

[0036] 700-Stabilizing Ring;

[0037] 800-Clamping component. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0040] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] A variable speed damper according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0043] Reference Figure 1 A variable speed damper according to an embodiment of the present invention includes a cylinder 100 and a piston 300. The piston 300 is slidably disposed inside the cylinder 100. The piston 300 divides the interior of the cylinder 100 to form a first chamber 110 and a second chamber 120. The first chamber 110 and the second chamber 120 are arranged sequentially along the depth direction of the cylinder 100. A fluid is injected into the cylinder 100, which can be hydraulic oil, water or gas.

[0044] The variable speed damper also includes a variable flow channel 200, which has a variable cross-sectional area. The variable flow channel 200 is disposed on the inner wall of the cylinder 100. A flow guide space is formed between the inner wall of the variable flow channel 200 and the radial outer surface of the piston 300. The flow guide space is used to allow fluid to flow from the second chamber 120 to the first chamber 110.

[0045] In some embodiments of the present invention, the variable flow channel 200 includes an oil guide groove 210 and an oil discharge chamber 220 arranged sequentially along the depth direction of the cylinder block 100. The oil guide groove 210 is used to guide fluid to flow from the second chamber 120 to the first chamber 110, and the oil discharge chamber 220 is used to discharge fluid from the second chamber 120 to the first chamber 110. The flow rate of fluid through the oil guide groove 210 is less than the flow rate of fluid through the oil discharge chamber 220.

[0046] It should be noted that the oil drain chamber 220 has a large space and can hold a large amount of fluid. Under the action of external force, the piston 300 continues to move deeper into the cylinder 100. The oil drain chamber 220 and the radial outer surface of the piston 300 cooperate, and the fluid quickly enters the first chamber through the oil drain chamber 220. The fluid in the first chamber increases rapidly. Under the pressure in the first chamber, the piston 300 obtains a large speed and accelerates instantaneously. This makes it easier for the hinges or latches to close the doors, windows, and flip-tops, or helps the locks of doors and windows to fit into the slots of the door frame, thus solving the problem of incomplete closure.

[0047] Furthermore, the variable flow channel 200 also includes an oil blocking surface 230, which is located between the oil guide groove 210 and the oil discharge chamber 220. The oil blocking surface 230 matches the radial outer surface of the piston 300. When the oil blocking surface 230 is engaged with the piston 300, the flow rate of the fluid passing through the oil blocking surface 230 is less than the flow rate of the fluid passing through the oil guide groove 210.

[0048] It should be noted that the oil-blocking surface 230 and the radial outer surface of the piston 300 are in clearance fit. That is to say, there is a very small gap between the oil-blocking surface 230 and the radial outer surface of the piston 300. Therefore, when the piston 300 moves to the position of the oil-blocking surface 230, only a small amount of fluid passes through the oil-blocking surface 230. At this time, the moving speed of the piston 300 reaches its slowest point, and the damping force of the damper is also the largest. Thus, it can prevent doors, windows, and flip covers from closing too quickly.

[0049] The stroke of piston 300 through oil resistance surface 230 can be flexibly designed according to the actual needs of the damper.

[0050] Understandably, referring to Figure 2As the piston 300 moves deeper into the cylinder 100 under the action of external force, the inner wall of the oil guide groove 210 engages with the radial outer surface of the piston 300. At this time, the oil guide groove 210 can guide the fluid to flow from the second chamber 120 to the first chamber 110. At this time, the piston 300 moves at a relatively slow speed. Next, the oil blocking surface 230 engages with the radial outer surface of the piston 300. The oil blocking surface 230 can restrict the fluid from flowing from the second chamber 120 to the first chamber 110. Only a small amount of fluid passes through the oil blocking surface 230. At this time, the piston 300 moves at its slowest speed. Finally, the inner wall of the oil discharge chamber 220 engages with the radial outer surface of the piston 300. The oil discharge chamber 220 discharges the fluid from the second chamber 120 to the first chamber 110. At this time, the piston 300 instantly gains a large speed, thereby enabling the hinge or latch to close.

[0051] Specifically, the oil guide groove 210 is at least one of the following: a straight groove extending linearly along the depth direction of the cylinder body 100, a spiral groove extending circumferentially along the inner wall of the cylinder body 100, and a straight groove and a spiral groove connected to each other.

[0052] Preferably, the oil guide groove 210 is a spiral groove extending circumferentially along the inner wall of the cylinder body 100 (e.g., Figure 4 The spiral groove is radially fitted with the piston 300. The fluid flows through the spiral groove to the first chamber 110. The spiral groove is curved and long. The inner wall of the spiral groove can generate a large resistance to the fluid, which helps to generate a large resistance to the fluid, thereby making the damper generate a large damping force.

[0053] Then, depending on the actual design requirements, the oil guide groove 210 can be designed as a straight groove extending in a straight line along the depth direction of the cylinder body 100, or it can be designed as a form in which the above straight groove and spiral groove are connected to each other.

[0054] It should be noted that, referring to Figure 4 There is one oil discharge chamber 220, which extends circumferentially along the inner wall of the cylinder 100. This allows the oil discharge chamber 220 to have a larger space and can hold a larger amount of fluid. The fluid is discharged from the second chamber 120 to the first chamber 110 through the oil discharge chamber 220, which can instantly increase the moving speed of the piston 300.

[0055] Of course, depending on the required amount of oil discharge, there can be multiple oil discharge chambers 220, which are distributed circumferentially along the inner wall of the cylinder block 100.

[0056] In a further embodiment of the present invention, the oil drain chamber 220 has an expansion section 221, the cross-sectional area of ​​which gradually increases along the depth direction of the cylinder block 100.

[0057] It is understandable that the shape of the expansion segment 221 is a conical surface, or the shape of the expansion segment 221 is a curved surface.

[0058] Preferably, the expansion section 221 is tapered, which makes the oil discharge chamber 220 easier to process.

[0059] Therefore, as the piston 300 moves deeper into the cylinder 100 from the oil discharge chamber 220, the oil discharge volume of the oil discharge chamber 220 gradually increases, which makes the piston 300 move faster. This makes it easier for the hinge or latch to close the door, window, or flip cover, or helps the door or window lock to engage in the slot of the door frame.

[0060] In a further embodiment of the present invention, the inner wall of the cylinder 100 is provided with a positioning surface 130, which matches the radial outer surface of the piston 300 and is located on the side of the oil discharge chamber 220 away from the oil guide groove 210. The oil discharge chamber 220 has a connecting section 222, one side of the connecting section 222 is connected to the expansion section 221, and the other side of the connecting section 222 is connected to the positioning surface 130.

[0061] When piston 300 moves to the position of oil discharge chamber 220, positioning surface 130 can stabilize piston 300, prevent piston 300 from wobbling, and ensure normal movement of piston 300.

[0062] The variable speed damper also includes a return channel 320 and a control element 400. The return channel 320 is disposed inside the piston 300 and is used to connect the first chamber 110 and the second chamber 120. The control element 400 is disposed inside the return channel 320 and is used to control the unidirectional flow of fluid from the first chamber 110 to the second chamber 120.

[0063] Because the gap between the oil-blocking surface 230 and the radial outer surface of the piston 300 is small, when the piston 300 moves towards the first chamber 110 under force, the fluid has difficulty passing through the oil-blocking surface 230. The control component 400 controls the return channel 320 to be open, and the fluid flows unidirectionally from the first chamber 110 to the second chamber 120. The fluid pressure in the first chamber 110 decreases, and the fluid pressure in the second chamber 120 increases, which can push the piston 300 to move, thereby enabling the piston 300 to move and reset quickly.

[0064] In some embodiments of the present invention, reference is made to... Figure 3 The return channel 320 has a narrowing position 322, and the control element 400 is a ball valve. When the fluid pressure in the first chamber 110 is less than the pressure in the second chamber 120, the ball valve is in the narrowing position 322 to prevent fluid from flowing from the second chamber 120 to the first chamber 110. When the fluid pressure in the first chamber 110 is greater than the pressure in the second chamber 120, the ball valve leaves the narrowing position 322 to allow fluid to flow from the first chamber 110 to the second chamber 120.

[0065] Understandably, when piston 300 moves toward the second chamber 120, the fluid pressure in the second chamber 120 increases. The pressure generated by the fluid causes the ball valve to be in the narrowed position 322, blocking the return passage 320. When piston 300 moves toward the first chamber 110, the fluid in the first chamber 110 exerts a thrust on the ball valve, causing the ball valve to leave the narrowed position 322. At this time, the return passage 320 is open, and the fluid can flow from the first chamber 110 to the second chamber 120. The opening and closing of the return passage 320 is simple, the control component 400 has a simple structure, and the manufacturing cost is low.

[0066] In a further embodiment of the present invention, the return channel 320 has a main channel 321 and a limiting part 323 disposed in the main channel 321. One end of the main channel 321 is connected to the second cavity 120, and the other end of the main channel 321 is connected to the narrowing part 322. The ball valve is housed inside the main channel 321, and the limiting part 323 is used to restrict the ball valve from leaving the main channel 321.

[0067] Therefore, by using the main flow path 321 to restrict the movement path of the ball valve, the ball valve can smoothly enter or leave the narrowed position 322. At the same time, the limiting part 323 can prevent the ball valve from deviating from the specific movement path.

[0068] It is understandable that the return channel 320 has a branch path, one end of which is connected to the narrowing position 322, and the other end of which is connected to the first cavity 110.

[0069] In a further embodiment of the present invention, the main flow path 321 extends along the axial direction of the piston 300, which is beneficial to the piston 300 being uniformly subjected to the pressure of the fluid, thus ensuring that the piston 300 moves smoothly.

[0070] In some embodiments of the present invention, a spring 500 is also included, which is located inside the cylinder 100 and is used to drive the piston 300 to move toward the first chamber 110.

[0071] Therefore, even without external force acting on piston 300, spring 500 can drive piston 300 to move and reset.

[0072] In some embodiments of the present invention, the piston 300 is provided with a push rod 310, and a seal 600 is fitted on the radial outer surface of the push rod 310. The push rod 310 is sealed to the inner wall of the cylinder 100 through the seal 600, thereby preventing fluid leakage inside the cylinder 100.

[0073] In a further embodiment of the invention, a stabilizing ring 700 is also included. The stabilizing ring 700 is located on the side of the seal 600 away from the piston 300. The stabilizing ring 700 is fitted onto the radial outer surface of the push rod 310, so that the push rod 310 is stabilized within the cylinder 100.

[0074] Therefore, by using the stabilizing ring 700 fitted on the radial outer surface of the push rod 310, and matching the inner surface of the cylinder 100, the push rod 310 is stabilized within the cylinder 100.

[0075] In a further embodiment of the present invention, a clamping member 800 is also included. The clamping member 800 is located on the side of the stabilizing ring 700 away from the seal 600. A groove 140 is provided on the inner wall of the cylinder body 100. The clamping member 800 is engaged with the groove 140 to prevent the stabilizing ring 700 from dislodging from the inside of the cylinder body 100.

[0076] Therefore, the clamping component 800 can be a retaining ring. By clamping the retaining ring with the retaining groove 140, the stabilizing ring 700 and the sealing ring can be prevented from dislodging from the cylinder body 100, thus making the damper assembly simpler and the disassembly and maintenance easier.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0078] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A variable speed damper, comprising a cylinder (100) and a piston (300), the piston (300) being slidably disposed inside the cylinder (100), the piston (300) dividing the interior of the cylinder (100) into a first cavity (110) and a second cavity (120), the first cavity (110) and the second cavity (120) being arranged sequentially along the depth direction of the cylinder (100), characterized in that, include: A variable flow channel (200) is provided with a variable cross-sectional area. The variable flow channel (200) is provided on the inner wall of the cylinder (100). A flow guide space is formed between the inner wall of the variable flow channel (200) and the radial outer surface of the piston (300). The flow guide space is used to allow fluid to flow from the second chamber (120) to the first chamber (110). A return channel (320) is disposed inside the piston (300) and the return channel (320) is used to connect the first chamber (110) and the second chamber (120). A control element (400) is disposed in the return channel (320) and is used to control the unidirectional flow of fluid from the first chamber (110) to the second chamber (120); The variable flow channel (200) includes an oil guide groove (210) and an oil discharge chamber (220) arranged sequentially along the depth direction of the cylinder block (100). The oil guide groove (210) is used to guide fluid from the second chamber (120) to the first chamber (110), and the oil discharge chamber (220) is used to discharge fluid from the second chamber (120) to the first chamber (110). The flow rate of fluid through the oil guide groove (210) is less than the flow rate of fluid through the oil discharge chamber (220). The variable flow channel (200) also includes an oil blocking surface (230), which is located between the oil guide groove (210) and the oil discharge chamber (220). The oil blocking surface (230) matches the radial outer surface of the piston (300). When the oil blocking surface (230) is engaged with the piston (300), the flow rate of fluid passing through the oil blocking surface (230) is less than the flow rate of fluid passing through the oil guide groove (210). The oil discharge chamber (220) has an expansion section (221), the cross-sectional area of ​​which gradually increases along the depth direction of the cylinder (100). The inner wall of the cylinder (100) is provided with a positioning surface (130), which matches the radial outer surface of the piston (300) and is located on the side of the oil discharge chamber (220) away from the oil guide groove (210). The oil discharge chamber (220) has a connecting section (222), one side of which is connected to the expansion section (221), and the other side of which is connected to the positioning surface (130).

2. The variable speed damper according to claim 1, characterized in that, The oil drain chamber (220) is one, and the oil drain chamber (220) extends circumferentially along the inner wall of the cylinder (100); or, the oil drain chamber (220) is multiple, and the multiple oil drain chambers (220) are distributed circumferentially along the inner wall of the cylinder (100).

3. A variable speed damper according to claim 1, characterized in that, The return channel (320) has a narrowing position (322), and the control element (400) is a ball valve. When the fluid pressure in the first chamber (110) is less than the pressure in the second chamber (120), the ball valve is in the narrowing position (322) to prevent fluid from flowing from the second chamber (120) to the first chamber (110). When the fluid pressure in the first chamber (110) is greater than the pressure in the second chamber (120), the ball valve leaves the narrowing position (322) to allow fluid to flow from the first chamber (110) to the second chamber (120).

4. A variable speed damper according to claim 3, characterized in that, The return channel (320) has a main flow path (321) and a limiting part (323) disposed in the main flow path (321). One end of the main flow path (321) is connected to the second cavity (120), and the other end of the main flow path (321) is connected to the narrowing part (322). The ball valve is housed inside the main flow path (321), and the limiting part (323) is used to restrict the ball valve from leaving the main flow path (321).

5. A variable speed damper according to claim 4, characterized in that, The main path (321) extends along the axial direction of the piston (300).

6. A variable speed damper according to claim 1, characterized in that, It also includes a spring (500) located inside the cylinder (100) and used to drive the piston (300) to move toward the first chamber (110).

Images