A damper

Abstract

The application provides a damper capable of completely eliminating or effectively reducing the idle stroke of the damper, comprising an inner cylinder, a liquid storage cylinder, a first sealing assembly, a bottom valve assembly and a piston assembly, wherein the piston assembly comprises a piston rod and a piston assembly. When the piston rod is in the maximum stroke state, the liquid level of the working liquid in the inner cylinder and the liquid level of the working liquid in the liquid storage cylinder are flush, and the liquid level of the working liquid in the inner cylinder is at least flush with the lower surface of the piston assembly; when the piston rod is in the maximum stroke state, the volume of the space above the working liquid level in the liquid storage cavity is a first volume, the volume of the space above the working liquid level in the inner cylinder and not occupied by the piston assembly is a second volume, and the part of the piston assembly above the working liquid level is a first part; when the piston assembly is completely pressed into the bottom of the inner cylinder, the volume of the first part below the working liquid level is less than or equal to the sum of the first volume and the second volume.

Description

Technical Field

[0001] This invention relates to the field of damper technology, and more specifically, to a damper capable of eliminating or reducing free travel. Background Technology

[0002] A damper is a device that provides resistance to motion and dissipates the energy of motion. Because the piston assembly and bottom valve of the damper are equipped with throttling orifices, when the working fluid is subjected to external pressure and passes through the throttling orifice, viscous resistance is generated, which can buffer the external motion and dissipate external energy. Therefore, hydraulic dampers have good buffering and shock absorption and energy dissipation functions, and are currently widely used in the automotive, photovoltaic, aerospace, and military industries.

[0003] In existing twin-cylinder hydraulic dampers on the market, when the piston assembly is compressed into the damper, it enters the damper and occupies the internal space. Therefore, when adding working fluid to the damper, it cannot be filled completely. Otherwise, the piston assembly cannot be compressed into the damper under external pressure, causing the damper to malfunction. Because the space in the damper without working fluid in the existing technology is relatively large, when the piston assembly starts to press into the damper from the initial state of the piston rod being at its maximum extension, the piston assembly cannot receive the resistance applied by the working fluid, resulting in a free stroke in the damper. This reduces the damper's shock absorption and energy dissipation effect, affects the stability of the damper's operation, and may even cause abnormal noise under certain operating conditions. Summary of the Invention

[0004] To address the technical problems in the prior art, this invention provides a damper that improves the structure of existing dampers. The improved damper can effectively reduce or even completely eliminate the damper's free stroke, improve the damper's vibration reduction and energy dissipation capabilities and operational stability, and expand the applicable application scenarios of the damper.

[0005] This invention provides a damper, comprising: an inner cylinder filled with a working fluid; a reservoir coaxially disposed outside the inner cylinder, the region between the inner wall of the reservoir and the outer wall of the inner cylinder forming a reservoir cavity; both ends of the reservoir are sealed; a first sealing assembly disposed at a first end of the inner cylinder for sealing the first end of the inner cylinder; a bottom valve assembly disposed at a second end of the inner cylinder, the bottom valve assembly being switchable between open and closed states to allow the inner cylinder to communicate with or isolate the reservoir cavity; a piston assembly including a piston assembly and a piston rod; the piston assembly being disposed within the inner cylinder and slidingly engaging with the inner wall of the inner cylinder, the piston assembly dividing the inner cylinder into a first chamber and a second chamber along the axial direction of the inner cylinder; the piston assembly including a piston body having a flow channel and a throttle valve assembly fitted with the flow channel; the throttle valve assembly being switchable between closed and open states to isolate the first chamber and the second chamber. Alternatively, it can be connected through the flow channel; the first end of the piston rod is connected to the piston assembly, and the second end of the piston rod extends to the outside of the inner cylinder and the reservoir after passing through the first sealing assembly; when the piston rod is in its maximum extended stroke state, the liquid level of the working liquid in the inner cylinder is flush with the liquid level of the working liquid in the reservoir, and the liquid level of the working liquid in the inner cylinder is at least flush with the lower surface of the piston assembly; wherein, when the piston rod is in its maximum extended stroke state, the volume of the space above the liquid level of the working liquid in the reservoir is the first volume, the volume of the space above the liquid level of the working liquid in the inner cylinder that is not occupied by the piston assembly is the second volume, and the portion of the piston assembly above the liquid level of the working liquid is the first component; when the piston assembly is completely pressed into the bottom of the inner cylinder, the volume of the first component below the liquid level of the working liquid is less than or equal to the sum of the first volume and the second volume.

[0006] As an improvement to the damper described in this invention, when the piston rod is in its maximum extended stroke state, the liquid level of the working fluid in the inner cylinder is at least flush with the upper surface of the piston assembly.

[0007] As an improvement to the damper described in this invention, the inner cylinder includes a working cylinder and a working cylinder extension that are interconnected and coaxially connected; the working cylinder and the working cylinder extension are integrally formed, or the working cylinder and the working cylinder extension are two independent components; the piston assembly is disposed inside the working cylinder; the area of ​​the end opening of the working cylinder extension near the working cylinder is smaller than the area of ​​the upper surface of the piston assembly, so as to prevent the piston assembly from entering the working cylinder extension, thereby limiting the maximum stroke of the piston rod extending outward.

[0008] As an improvement to the damper described in this invention, the end face of the extension portion of the working cylinder near the working cylinder is a first end face; when the piston rod is in the extended maximum stroke state, the first end face is flush with the liquid level of the working fluid in the inner cylinder.

[0009] As an improvement to the damper described in this invention, when the piston rod is in its maximum extended stroke state, the sum of the volume of the space above the plane where the first end face is located in the reservoir cavity and the volume of the space in the extension of the working cylinder not occupied by the piston rod is equal to the volume of the piston rod in the working cylinder when the piston assembly is completely pressed into the bottom of the inner cylinder.

[0010] As an improvement to the damper described in this invention, the inner wall of the extension of the working cylinder is in close sliding fit with the piston rod, and the volume of the space above the plane of the first end face in the liquid storage cavity is equal to the volume of the piston rod in the working cylinder when the piston assembly is fully pressed into the bottom of the inner cylinder.

[0011] As an improvement of the damper described in this invention, the working cylinder extension is a piston rod guide extension sleeve independent of the working cylinder, and the end of the piston rod guide extension sleeve near the working cylinder is a stop structure for assembly and connection with the corresponding port of the working cylinder.

[0012] As an improvement to the damper described in this invention, the piston assembly further includes a limiting member, which is fixedly disposed on the piston rod and located above the piston assembly. The limiting member is capable of limiting the maximum outward stroke of the piston rod.

[0013] As an improvement to the damper described in this invention, a guide is also included, which is disposed between the first end of the inner cylinder and the first sealing assembly for guiding the piston rod.

[0014] As an improvement to the damper described in this invention, a dust cover is also included. The dust cover is disposed on the outside of the liquid storage cylinder, and the top of the dust cover is fixedly connected to the second end of the piston rod and moves synchronously with the piston rod.

[0015] Compared with the prior art, the damper provided by the present invention has the following beneficial effects:

[0016] 1. In the damper provided by this invention, the internal space and the amount of working fluid are specially designed so that when the piston rod in the damper is in its maximum extended stroke state, the liquid level of the working fluid in the inner cylinder is flush with the liquid level of the working fluid in the reservoir, and the liquid level of the working fluid in the inner cylinder is at least flush with the lower surface of the piston assembly; simultaneously, when the piston assembly is fully pressed into the bottom of the inner cylinder, the volume of the first component in the piston assembly below the liquid level of the working fluid is less than or equal to the sum of the first volume in the reservoir and the second volume in the inner cylinder. Through the aforementioned special design, it can be ensured that the piston rod in the piston assembly can immediately contact the working fluid when it starts to press down from the initial state of maximum extended stroke, thereby generating appropriate resistance to the movement of the piston assembly, reducing the idle stroke of the damper, and at the same time, the inside of the damper can provide sufficient accommodating space for the downward pressing of the piston assembly, so that the piston assembly can be smoothly pressed into the inside of the damper under external pressure.

[0017] 2. In the damper provided by the present invention, when the piston rod is in the extended maximum stroke state, the liquid level of the working fluid in the inner cylinder is at least flush with the upper surface of the piston assembly, so that the piston assembly can be completely immersed in the working fluid. During the process of the piston rod in the piston assembly being pressed into the damper from the initial state of extended maximum stroke, it can always be fully subjected to the resistance exerted by the working fluid, thereby completely eliminating the idle stroke of the damper.

[0018] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0019] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0020] Figure 1 This is a longitudinal cross-sectional view of the damper in Embodiment 1 of the present invention;

[0021] Figure 2 for Figure 1 A magnified view of a portion of region A in the middle;

[0022] Figure 3 for Figure 1 A magnified view of a portion of region B in the middle;

[0023] Figure 4 This is a longitudinal cross-sectional view of a damper with another inner cylinder structure used in Example 1;

[0024] Figure 5 This is a longitudinal cross-sectional view of a damper with another inner cylinder structure used in Example 1;

[0025] Figure 6 This is a longitudinal cross-sectional view of the damper in Example 2.

[0026] The correspondence between each mark and the part name is as follows:

[0027] 1-First rod end bearing, 2-Working cylinder extension, 3-Working cylinder, 4-Reservoir, 5-Dust cover, 6-Piston rod, 7-Piston assembly, 8-Bottom valve assembly, 9-Second rod end bearing, 10-Inner cylinder, 11-Piston assembly, 12-Guide, 13-First sealing assembly, 14-Piston body, 15-Flow channel, 16-Throttle valve assembly, 17-Stop, 18-Limiting element. Detailed Implementation

[0028] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0029] Example 1

[0030] See Figure 1-3 As shown, this embodiment provides a damper, specifically including:

[0031] The inner cylinder 10 is filled with a working fluid. Specifically, in this embodiment, the inner cylinder is a cylindrical structure and the working fluid in the damper is silicone oil. Of course, in other embodiments, the inner cylinder can be other suitable mechanisms and the working fluid can be other working fluids that meet the actual needs of the damper. The present invention does not impose any specific limitations.

[0032] The liquid storage cylinder 4 is coaxially disposed on the outside of the inner cylinder 10, and the area between the inner wall of the liquid storage cylinder 4 and the outer wall of the inner cylinder 10 forms a liquid storage cavity; both ends of the liquid storage cylinder 4 are sealed by a sealing assembly; specifically, in this embodiment, the liquid storage cylinder 4 is also a cylindrical structure, the liquid storage cylinder 4 and the inner cylinder 10 are concentrically nested, and the length of the liquid storage cylinder 4 is greater than or equal to the length of the inner cylinder, and the liquid storage cavity is the annular area formed by the inner wall of the liquid storage cylinder 4 and the outer wall of the inner cylinder 10;

[0033] The first sealing component 13 is disposed at the first end of the inner cylinder 10 and is used to seal the first end of the inner cylinder 10. Specifically, in this embodiment, the first sealing component 13 can simultaneously seal the first end of the inner cylinder 10 and the corresponding port of the liquid storage cylinder 4. Of course, in other embodiments, the port sealing of the inner cylinder 10 and the port sealing of the liquid storage cylinder 4 can be achieved by different sealing components. This invention does not impose any restrictions, as long as the sealing effect can be achieved.

[0034] Bottom valve assembly 8 is located at the second end of inner cylinder 10. Bottom valve assembly 8 can switch between open and closed states to connect or isolate inner cylinder 10 from liquid storage chamber. When piston assembly 11 in damper is subjected to external force and slides in inner cylinder 10, if the pressure difference between inner cylinder 10 and liquid storage chamber is greater than a preset threshold, bottom valve assembly 8 opens to connect inner cylinder 10 to liquid storage chamber. If there is no pressure difference between inner cylinder 10 and liquid storage chamber, bottom valve assembly 8 closes to isolate inner cylinder 10 from liquid storage chamber.

[0035] The piston assembly 11 includes a piston assembly 7 and a piston rod 6. The piston assembly 7 is disposed inside the inner cylinder 10 and slides against the inner wall of the inner cylinder 10. The piston assembly 7 divides the inner cylinder 10 into a first chamber and a second chamber along the axial direction of the inner cylinder 10. The piston assembly 7 includes a piston body with a flow channel and a throttle valve assembly that is fitted with the flow channel. The throttle valve assembly can switch between two states: closed and open, so that the first chamber and the second chamber are isolated or connected through the flow channel. The first end of the piston rod 6 is connected to the piston assembly 7, and the second end of the piston rod 6 extends to the outside of the inner cylinder 10 and the reservoir 4 after passing through the first sealing assembly 13. When the piston assembly 11 in the damper is subjected to an external force and slides in the inner cylinder 10, if the pressure difference between the first chamber and the second chamber of the inner cylinder 10 is greater than a preset threshold, the throttle valve assembly on the piston assembly 7 opens to connect the first chamber and the second chamber. If there is no pressure difference between the first chamber and the second chamber, the throttle valve assembly closes to isolate the first chamber and the second chamber.

[0036] When the piston rod 6 is in the extended maximum stroke state, the liquid level of the working fluid in the inner cylinder 10 is level with the liquid level of the working fluid in the storage cylinder 4, and the liquid level of the working fluid in the inner cylinder 10 is at least level with the lower surface of the piston assembly 7, that is, the liquid level of the working fluid is level with or higher than the lower surface of the piston assembly 7.

[0037] Specifically, when the piston rod 6 is in its maximum extended stroke state, i.e., when the piston rod 6 is extended to the outside of the damper to the maximum extent, the volume of the space above the working fluid surface in the reservoir is the first volume, the volume of the space above the working fluid surface in the inner cylinder 10 that is not occupied by the piston assembly 11 is the second volume, and the portion of the piston assembly 11 above the working fluid surface is the first component. It should be noted that, since the working fluid surface in the inner cylinder 10 is flush with or higher than the lower surface of the piston assembly 7 when the piston rod 6 is in its maximum extended stroke state, when the working fluid surface in the inner cylinder 10 is flush with the lower surface of the piston assembly 7, the first component is the entire piston assembly 11. When the working fluid surface in the inner cylinder 10 is higher than the lower surface of the piston assembly 7, since a part of the piston assembly 11 is submerged in the working fluid and located below the working fluid surface, the first component is only the portion of the piston assembly above the working fluid surface, not the entire piston assembly 11.

[0038] When the piston assembly 7 is fully pressed into the bottom of the inner cylinder 10, that is, when the piston rod 6 is pressed into the damper to the maximum extent, the volume of the first component below the liquid surface of the working fluid is less than or equal to the sum of the first volume and the second volume.

[0039] Through the aforementioned design principles, this invention matches the internal space of the damper, the volume of the piston assembly 11, and the working fluid filling the damper. This ensures that when the piston rod 6 in the piston assembly 11 starts to press down from its maximum extension state, it immediately contacts the working fluid, thereby generating appropriate resistance to the movement of the piston assembly 11 and reducing the idle stroke of the damper. At the same time, the inside of the damper provides sufficient space for the piston assembly 11 to press down, allowing the piston assembly 11 to be smoothly pressed into the damper under external pressure, thus playing a role in buffering, shock absorption, and energy dissipation.

[0040] Furthermore, in this embodiment, the damper also includes a guide 12, which is disposed between the first end of the inner cylinder 10 and the first sealing assembly 13 to guide the piston rod 6. At the same time, in order to prevent external dust and other objects from adhering to the surface of the piston rod 6 and being carried into the interior of the damper by the piston rod 6, a dust cover 5 is also provided in the damper. The dust cover 5 is disposed on the outside of the liquid storage cylinder 4, and the top of the dust cover 5 is fixedly connected to the second end of the piston rod 6 and moves synchronously with the piston rod 6.

[0041] Preferably, when the piston rod 6 is in its maximum extended stroke state, the liquid level of the working fluid in the inner cylinder 10 is at least flush with the upper surface of the piston assembly 7. With this preferred design, when the piston rod 6 is in its maximum extended stroke state, the piston assembly 7 can be completely immersed in the working fluid. As the piston rod 6 in the piston assembly 11 is pressed into the damper from its initial maximum extended stroke state, it is always fully subjected to the resistance exerted by the working fluid, thereby completely eliminating the damper's free stroke and making the damper's operation more stable.

[0042] Furthermore, in this embodiment, the inner cylinder 10 includes a working cylinder 3 and a working cylinder extension 2 that are interconnected and coaxially connected; the piston assembly 7 is disposed inside the working cylinder 3, and the area of ​​the end opening of the working cylinder extension 2 near the working cylinder 3 is smaller than the area of ​​the upper surface of the piston assembly 7, so as to prevent the piston assembly 7 from entering the working cylinder extension 2, thereby limiting the maximum stroke of the piston rod 6 extending outward. At the same time, since the piston assembly 11 will occupy the space originally occupied by the working fluid when it is pressed into the damper, the space in the working cylinder extension 2 and the upper space of the reservoir 4 also provide flow space for the working fluid in the damper.

[0043] In specific implementation, such as Figure 4 and Figure 5 As shown, the working cylinder 3 and the working cylinder extension 2 are integrally formed, or the working cylinder 3 and the working cylinder extension 2 are two independent components. When the working cylinder 3 and the working cylinder extension 2 are integrally formed, the following specific implementation methods can be adopted: (1) such as Figure 5 As shown, the working cylinder 3 and the working cylinder extension 2 are two continuous pipe sections with different diameters in the same pipe fitting, and the diameter of the working cylinder extension 2 is smaller than that of the working cylinder 3 to prevent the piston assembly 7 from entering the working cylinder extension 2 from the working cylinder 3; (2) as Figure 4 As shown, the working cylinder 3 and the working cylinder extension 2 are two continuous pipe sections with the same diameter in the same pipe fitting, but a stop 17 is provided at the connection of the two pipe sections to prevent the piston assembly 7 from entering the working cylinder extension 2 from the working cylinder 3. When the working cylinder 3 and the working cylinder extension 2 are two independent components, the following specific implementation methods can be adopted: (1) As Figure 1 and Figure 5 As shown, the working cylinder 3 and the working cylinder extension 2 are two independent pipes, which are connected by a suitable joining method such as welding or snap-fitting. The diameter of the working cylinder extension 2 is smaller than that of the working cylinder 3 to prevent the piston assembly 7 from entering the working cylinder extension 2 from the working cylinder 3; (2) as Figure 4As shown, the working cylinder 3 and the working cylinder extension 2 are two independent pipe fittings with the same diameter. They are connected by a suitable joining method such as welding or snap-fitting. However, a stop 17 is provided at the connection point of the two pipe fittings to prevent the piston assembly 7 from entering the working cylinder extension 2 from the working cylinder 3. It should be noted that the above-listed implementation methods are not exhaustive. In other embodiments, other implementation methods that can realize the concept of the present invention may also be used.

[0044] Furthermore, in this embodiment, the end face of the working cylinder extension 2 near the working cylinder 3 is the first end face; when the piston rod 6 is in its maximum extended stroke state, the first end face is flush with the liquid level of the working fluid in the inner cylinder 10. When the piston rod 6 is in its maximum extended stroke state, the sum of the volume of the space above the plane of the first end face in the liquid storage chamber and the volume of the space in the working cylinder extension 2 not occupied by the piston rod 6 is equal to the volume of the piston rod in the working cylinder 3 when the piston assembly is fully pressed into the bottom of the inner cylinder 10. This design eliminates the damper's idle stroke while minimizing the amount of working fluid filled inside the damper, reducing the reserved space inside the damper, and improving the overall compactness of the damper while reducing costs.

[0045] Preferably, in this embodiment, the inner wall of the working cylinder extension 2 is in close sliding fit with the piston rod 6, and the volume of the space above the plane of the first end face in the liquid storage cavity is equal to the volume of the piston rod in the working cylinder when the piston assembly is fully pressed into the bottom of the inner cylinder. Specifically, in this embodiment, the working cylinder extension 2 is a piston rod guide extension sleeve independent of the working cylinder 3, and the end of the piston rod guide extension sleeve near the working cylinder 3 is a stop structure for assembly connection with the corresponding port of the working cylinder 3. Setting the working cylinder extension 2 as a piston rod guide extension sleeve can, on the one hand, limit the stroke of the piston rod 6 extending outward from the damper, and on the other hand, extend the guiding distance of the piston rod 6, improve the stability when the piston rod 6 extends or retracts, and thus improve the overall operational stability of the damper.

[0046] Furthermore, a first rod end bearing 1 is fixedly installed at the second end of the piston rod 6, and a second rod end bearing 9 is fixedly installed at the end of the damper away from the second end of the piston rod. By installing the first rod end bearing 1 and the second rod end bearing 9, the connection between the damper and external components can be facilitated.

[0047] Example 2

[0048] like Figure 6 As shown, this embodiment provides a damper, specifically including:

[0049] Inner cylinder 10, which is filled with working fluid;

[0050] The liquid storage cylinder 4 is coaxially disposed on the outside of the inner cylinder 10, and the area between the inner wall of the liquid storage cylinder 4 and the outer wall of the inner cylinder 10 forms a liquid storage cavity; both ends of the liquid storage cylinder 4 are sealed.

[0051] The first sealing component 13 is disposed at the first end of the inner cylinder 10 and is used to seal the first end of the inner cylinder 10.

[0052] The bottom valve assembly 8 is located at the second end of the inner cylinder 10. The bottom valve assembly 8 can switch between open and closed states to allow the inner cylinder 10 to communicate with or isolate the liquid storage chamber.

[0053] The piston assembly 11 includes a piston assembly 7 and a piston rod 6. The piston assembly 7 is disposed inside the inner cylinder 10 and slides against the inner wall of the inner cylinder 10. The piston assembly 7 divides the inner cylinder 10 into a first chamber and a second chamber along the axial direction of the inner cylinder 10. The piston assembly 7 includes a piston body with a flow channel and a throttle valve assembly that is fitted with the flow channel. The throttle valve assembly can switch between two states, a closed state and an open state, so that the first chamber and the second chamber are isolated or connected through the flow channel. The first end of the piston rod 6 is connected to the piston assembly 7, and the second end of the piston rod 6 extends to the outside of the inner cylinder 10 and the liquid storage tank 4 after passing through the first sealing assembly 13.

[0054] When the piston rod 6 is in the extended maximum stroke state, the liquid level of the working fluid in the inner cylinder 10 is level with the liquid level of the working fluid in the storage cylinder 4, and the liquid level of the working fluid in the inner cylinder 10 is at least level with the lower surface of the piston assembly 7, that is, the liquid level of the working fluid is level with or higher than the lower surface of the piston assembly 7.

[0055] Specifically, when the piston rod 6 is in its maximum extended stroke state, i.e., when the piston rod 6 is extended to the outside of the damper to the maximum extent, the volume of the space above the working fluid surface in the reservoir is the first volume, the volume of the space above the working fluid surface in the inner cylinder 10 that is not occupied by the piston assembly 11 is the second volume, and the portion of the piston assembly 11 above the working fluid surface is the first component. It should be noted that, since the working fluid surface in the inner cylinder 10 is flush with or higher than the lower surface of the piston assembly 7 when the piston rod 6 is in its maximum extended stroke state, when the working fluid surface in the inner cylinder 10 is flush with the lower surface of the piston assembly 7, the first component is the entire piston assembly 11. When the working fluid surface in the inner cylinder 10 is higher than the lower surface of the piston assembly 7, since a part of the piston assembly 11 is submerged in the working fluid and located below the working fluid surface, the first component is only the portion of the piston assembly above the working fluid surface, not the entire piston assembly 11.

[0056] When the piston assembly 7 is fully pressed into the bottom of the inner cylinder 10, that is, when the piston rod 6 is pressed into the damper to the maximum extent, the volume of the first component below the liquid surface of the working fluid is less than or equal to the sum of the first volume and the second volume.

[0057] Preferably, when the piston rod 6 is in its maximum extended stroke state, the liquid level of the working fluid in the inner cylinder 10 is at least flush with the upper surface of the piston assembly 7. With this preferred design, when the piston rod 6 is in its maximum extended stroke state, the piston assembly 7 can be completely immersed in the working fluid. As the piston rod 6 in the piston assembly 11 is pressed into the damper from its initial maximum extended stroke state, it is always fully subjected to the resistance exerted by the working fluid, thereby completely eliminating the damper's free stroke and making the damper's operation more stable.

[0058] Specifically, in this embodiment, such as Figure 6 As shown, both the inner cylinder 10 and the liquid storage cylinder 4 are complete circular tubular structures with uniform inner diameters. The piston assembly 11 also includes a limiting member 18, which is fixedly disposed on the piston rod and located above the piston assembly. The limiting member 18 can limit the maximum stroke of the piston rod extending outward. By providing a limiting member 18 on the piston rod 6 and setting the distance between the upper end face of the limiting member 18 and the piston assembly according to actual needs, when the piston rod 6 is in its maximum extended stroke state, the limiting member 18 can restrict the position of the piston assembly 7 in the inner cylinder 10. This ensures that the piston assembly 7 can be completely immersed in the working fluid or that the lower surface of the piston assembly 7 is flush with the liquid surface of the working fluid. At the same time, sufficient space is reserved above the liquid surface of the working fluid in the reservoir 4 and the inner cylinder 10 to accommodate the working fluid displaced when the piston assembly 11 is pressed into the bottom of the inner cylinder 10. This allows the piston assembly 11 to be smoothly pressed into the damper, ensuring the normal operation of the damper. It also effectively reduces or eliminates the idle stroke in the damper. Specifically, in this embodiment, the limiting member 18 is a wing fixedly mounted on the piston rod 6. Of course, in other embodiments, the limiting member can also be other structures, as long as it can restrict the position of the piston assembly 7 in the inner cylinder 10 according to actual needs.

[0059] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A damper characterized by, The application relates to a piston pump, which comprises the following components: an inner cylinder filled with working liquid; a liquid storage cylinder coaxially arranged outside the inner cylinder, a region between the inner wall of the liquid storage cylinder and the outer wall of the inner cylinder being formed into a liquid storage cavity; both ends of the liquid storage cylinder being sealed; a first sealing assembly arranged at the first end of the inner cylinder and used for sealing the first end of the inner cylinder; a bottom valve assembly arranged at the second end of the inner cylinder, the bottom valve assembly being capable of being switched between an open state and a closed state so as to make the inner cylinder communicate with or be isolated from the liquid storage cavity; a piston assembly comprising a piston component and a piston rod; the piston component is arranged in the inner cylinder and is in sliding fit with the inner wall of the inner cylinder; the piston component divides the inner cylinder into a first chamber and a second chamber along the axial direction of the inner cylinder; the piston component comprises a piston body provided with a flow channel and a throttle valve assembly assembled with the flow channel; the throttle valve assembly is capable of being switched between a closed state and an open state so as to make the first chamber and the second chamber be isolated or communicate through the flow channel; the first end of the piston rod is connected with the piston component, and the second end of the piston rod extends to the outside of the inner cylinder and the liquid storage cylinder after passing through the first sealing assembly; when the piston rod is in the state of extending to the maximum stroke, the liquid level of the working liquid in the inner cylinder is flush with the liquid level of the working liquid in the liquid storage cylinder, and the liquid level of the working liquid in the inner cylinder is at least flush with the lower surface of the piston component; wherein, when the piston rod is in the state of extending to the maximum stroke, the volume of the space in the liquid storage cavity above the liquid level of the working liquid is a first volume, the volume of the space in the inner cylinder above the liquid level of the working liquid and not occupied by the piston assembly is a second volume, and the part of the piston assembly above the liquid level of the working liquid is a first part; when the piston component is completely pressed into the bottom of the inner cylinder, the volume of the part below the liquid level of the working liquid is less than or equal to the sum of the first volume and the second volume; the inner cylinder comprises a working cylinder and a working cylinder extension which are coaxially and continuously arranged; the working cylinder and the working cylinder extension are integrally formed, or the working cylinder and the working cylinder extension are two independent components; the piston component is arranged in the working cylinder; the area of the end opening of the working cylinder extension close to the working cylinder is smaller than the area of the upper surface of the piston component, so as to prevent the piston component from entering the working cylinder extension and further limit the maximum stroke of the piston rod extending outward; a guide is further arranged between the first end of the inner cylinder and the first sealing assembly and used for guiding the piston rod; the working cylinder extension is a piston rod guide extension sleeve which is independent of the working cylinder; one end of the piston rod guide extension sleeve close to the working cylinder is a stop opening structure used for assembling and connecting with the corresponding port of the working cylinder.

2. A damper according to claim 1, wherein when the piston rod is in the state of extending to the maximum stroke, the liquid level of the working liquid in the inner cylinder is at least flush with the upper surface of the piston component.

3. A damper according to claim 1, wherein The end face of the working cylinder extension part near the working cylinder is a first end face; when the piston rod is in the maximum stroke state, the first end face is flush with the liquid level of the working liquid in the inner cylinder.

4. A damper according to claim 3, wherein When the piston rod is in the maximum stroke state, the sum of the volume of the space in the liquid storage cavity above the plane where the first end face is located and the volume of the space in the working cylinder extension part not occupied by the piston rod is equal to the volume of the piston rod located in the working cylinder when the piston assembly is completely pressed into the bottom of the inner cylinder.

5. A damper according to claim 4, wherein The inner wall of the working cylinder extension part is in close sliding fit with the piston rod, and the volume of the space in the liquid storage cavity above the plane where the first end face is located is equal to the volume of the piston rod located in the working cylinder when the piston assembly is completely pressed into the bottom of the inner cylinder.

6. A damper according to claim 1 or 2, characterised in that The piston assembly further comprises a limiting piece, which is fixedly arranged on the piston rod, and the limiting piece is located above the piston assembly, and the limiting piece can limit the maximum stroke of the piston rod.

7. The damper of claim 1, wherein Further comprising a dust cover, which is covered outside the liquid storage cylinder, and the top of the dust cover is fixedly connected with the second end of the piston rod and moves synchronously with the piston rod.

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