A multi-stage damping force viscous damper

Abstract

This invention relates to the field of damper technology. A multi-stage viscous damper includes a first bushing and a second bushing placed at both ends of a cylinder to form a sealed chamber inside the cylinder; a threaded pressure tube and an ear plate screwed to the cylinder and used to fix the first bushing and the second bushing to the cylinder; a piston rod passing through the central inner hole of the first bushing and the second bushing; a pin head fixed to the end of the piston rod and located outside the damper cylinder; and a viscous fluid damping material filling the damping chamber. The piston rod is mounted on a shaft inside the cylinder, with a fixed piston fixed to the piston rod and a sliding piston loosely fitted on the piston rod shaft. One or more sliding pistons are provided, and piston positioning rings are provided between adjacent sliding pistons and between the last sliding piston and the second bushing. By using the fixed piston and multiple sliding pistons to work in stages, different damping forces are applied in stages according to the displacement, so that the damping force increases stepwise with the increase of displacement.

Description

Technical Field

[0001] This invention relates to the field of damper technology, specifically to a multi-stage damping force viscous damper. Background Technology

[0002] Viscous dampers are important seismic isolation devices, widely used due to their lack of additional stiffness and reusability. They possess a high energy dissipation capacity, entering an energy-dissipating state first during strong earthquakes to consume seismic energy and attenuate the seismic response of the structure, protecting the main structure and components from damage and thus ensuring structural safety during strong earthquakes. Energy-dissipating and seismic isolation structures using viscous dampers can reduce seismic response by 40% to 60% compared to traditional seismic-resistant structures.

[0003] A viscous damper consists of a cylinder, piston, damping orifice, viscous fluid damping material, and piston rod. The piston reciprocates within the cylinder. The piston has damping channels, and the cylinder is filled with viscous fluid damping material.

[0004] Its energy dissipation principle is as follows: When the viscous damper is working, as the piston reciprocates relative to the cylinder, the viscous fluid damping material flows from the high-pressure chamber through the damping channel on the piston to the low-pressure chamber. During the reciprocating flow of the viscous fluid damping material through the damping channel, energy is dissipated due to overcoming factors such as friction and collision.

[0005] The theoretical damping force calculation formula for existing viscous dampers is: F = C|υ| α Sign(υ), where C is the damping coefficient of the damper, α is the damping index of the damper, and υ is the velocity at the displacement point.

[0006] Existing viscous dampers can only provide additional damping to the main structure under seismic loading, serving only as structural reinforcement and contributing nothing to the structure's stiffness. For the safety of the main structure under seismic loading, both structural strength and displacement control are necessary. Excessive displacement exceeding allowable values ​​will lead to shear failure of the main structure. Additional stiffness plays a significant role in controlling structural displacement under seismic loading.

[0007] An ideal seismic damper should operate as follows: under wind-induced vibration and minor earthquakes, it should not provide additional stiffness, making the structure more flexible. This reduces seismic response while simultaneously strengthening the structure using additional damping. By increasing the additional damping ratio, it can achieve higher performance targets while reducing the amount of steel used in the main structure and lowering costs. Under moderate, major, and rare earthquakes, it should provide additional damping and additional stiffness to the main structure, controlling the inter-story drift angle of the main structure under these conditions and protecting it from damage.

[0008] Therefore, it is necessary to invent a multi-stage damping viscous damper that provides low energy consumption with low additional stiffness and damping force under minor earthquakes and wind-induced vibrations, medium energy consumption with low additional stiffness and damping force under moderate earthquakes, and high energy consumption with high additional stiffness, high damping force, and high energy consumption under major earthquakes and rare earthquakes, thereby protecting the main structure from damage from both strength and stiffness improvements. Summary of the Invention

[0009] This invention addresses the shortcomings of existing technologies by providing a multi-stage damping viscous damper. It applies different damping forces in stages according to the displacement magnitude through a fixed piston and multiple sliding pistons working in stages. This achieves a step-like increase in damping force as the displacement increases, effectively adding an additional stiffness to the hysteresis curves under moderate, large, and rare earthquakes. This enhances the damper's displacement control capability under these conditions, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations; moderate energy consumption with low additional stiffness and moderate damping force under moderate earthquakes; and high energy consumption with high additional stiffness and high damping force under large and rare earthquakes. This improves both strength and stiffness, protecting the main structure from damage.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0011] A multi-stage damping viscous damper includes a first bushing and a second bushing placed at both ends of a cylinder to form a sealed chamber inside the cylinder; a threaded pressure tube and an ear plate screwed to the cylinder and used to fix the first bushing and the second bushing to the cylinder; a piston rod passing through the central inner hole of the first bushing and the second bushing; a pin head set outside the damper cylinder and fixed to the end of the piston rod; a viscous fluid damping material filling the damping chamber; a fixed piston and a sliding piston loosely fitted on the piston rod shaft are provided on the shaft of the piston rod placed inside the cylinder; one or more sliding pistons are provided; piston positioning rings are provided between adjacent sliding pistons and between the last sliding piston and the second bushing; the piston positioning rings adopt a split structure and are fixed to the positioning groove on the piston rod after being closed with screws.

[0012] Furthermore, a shaft head with a width of B1 is provided between the fixed piston and the first sliding piston.

[0013] Furthermore, when the fixed piston is at displacement 0, the distance from its end face near the first bushing to the end face of the first bushing is the limit displacement U0 of the damper. The distance from the end face of the piston positioning ring between the last sliding piston and the second bushing to the end face of the second bushing is also the limit displacement U0 of the damper. The end face of the first sliding piston maintains a distance A1 from the piston rod shoulder. The end face of the piston positioning ring between the first sliding piston and the next sliding piston maintains a distance A1 from the end face of the first sliding piston. The end face of the piston positioning ring between the next sliding piston and the previous sliding piston maintains a distance A from the end face of the sliding piston. nThe other end face of the sliding piston maintains a distance A from the end face of the next piston positioning ring. n And A1 is less than A n-1 A n-1 Less than A n A n It is less than the limit displacement U0.

[0014] By using a fixed piston and multiple sliding pistons working in stages, different damping forces are applied in stages according to the displacement magnitude. This achieves a stepwise increase in damping force as the displacement increases, effectively adding an additional stiffness to the hysteresis curves under moderate, large, and rare earthquakes. This enhances the damper's displacement control capability under these conditions, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations, moderate energy consumption with low additional stiffness and moderate damping force under moderate earthquakes, and high energy consumption with high additional stiffness and high damping force under large and rare earthquakes. This protects the main structure from damage by improving both strength and stiffness.

[0015] The aforementioned multi-stage damping viscous damper does not provide additional stiffness under wind-induced vibration and minor earthquakes, making the structure more flexible. Thus, while reducing seismic response, it utilizes the principle of structural reinforcement through additional damping to increase the additional damping ratio, thereby achieving higher performance targets while reducing the amount of steel used in the main structure and lowering costs.

[0016] Furthermore, the theoretical damping force calculation formula for the damper is: when the displacement amplitude is less than or equal to A1 When the displacement amplitude is greater than A1 and less than or equal to A2, the displacement during the damper compression process is from -U to -(U-2A1). Displacement - (U-2A1) to segment U During the damper's stretching process, the displacement U reaches the (U-2A1) segment. Displacement (U-2A1) to segment -U When the displacement amplitude is greater than A2 and less than or equal to A3, the displacement during the damper compression process is from -U to -(U-2A1). Displacement from -(U-2A1) to -(U-2A2) segment Displacement - (U-2A2) to segment U During the damper's stretching process, the displacement U to U-2A1 segment Displacement segment U-2A1 to U-2A2 Displacement U-2A2 to -U segment When the displacement amplitude is greater than A3 and less than or equal to A n During the damper compression process, the displacement is from -U to -(U-2A1). Displacement from -(U-2A1) to -(U-2A2) segment Displacement - (U-2A) n-1 ) to -(U-2A n)part Displacement - (U-2A) n (to U segment) During the damper's stretching process, the displacement U to U-2A1 segment Displacement segment U-2A1 to U-2A2 Displacement (U-2A) n-1 ) to U-2A n part Displacement U-2A n to -U segment Where C1 is the damping coefficient of the fixed piston, C2 is the damping coefficient of the first sliding piston, C3 is the damping coefficient of the second sliding piston, and C... n C is the damping coefficient of the (n-1)th sliding piston. n+1 Let α be the damping coefficient of the nth sliding piston, α1 be the damping index of the fixed piston, α2 be the damping index of the first sliding piston, and α3 be the damping index of the second sliding piston. n Let α be the damping exponent of the (n-1)th sliding piston. n+1 Let U be the damping index of the nth sliding piston, U be the displacement amplitude of the damper, A1 be the set sliding displacement amplitude of the first sliding piston, A2 be the set sliding displacement amplitude of the second sliding piston, A3 be the set sliding displacement amplitude of the third sliding piston, and A... n Let υ be the set sliding displacement amplitude of the nth sliding piston, and let υ be the velocity at that displacement point.

[0017] Furthermore, the damping coefficient C1 of the fixed piston, the damping coefficient C2 of the first sliding piston, the damping coefficient C3 of the second sliding piston, and the damping coefficient C of the nth sliding piston are... n+1 They can be equal or unequal.

[0018] Furthermore, the damping index α1 of the fixed piston, the damping index α2 of the first sliding piston, the damping index α3 of the second sliding piston, and the damping index α of the nth sliding piston are... n+1 They can be equal or unequal.

[0019] Furthermore, the outer diameters of the fixed piston, the first sliding piston, the second sliding piston, and the nth sliding piston may be equal or unequal.

[0020] Furthermore, the widths of the fixed piston, the first sliding piston, the second sliding piston, and the nth sliding piston can be equal or unequal.

[0021] Furthermore, the damping orifices on the fixed piston, the first sliding piston, the second sliding piston, and the nth sliding piston can be of equal or unequal size.

[0022] Furthermore, the sealed chamber inside the cylinder is filled with viscous fluid damping material. There is a gap between the outer cylindrical surface of the piston and the inner wall of the cylinder, and a damping hole is provided on the piston. When the viscous damper is working, as the piston reciprocates relative to the cylinder, the viscous fluid damping material flows from the high-pressure chamber through the gap between the piston and the cylinder and the damping hole on the piston to the low-pressure chamber. During the process of the viscous fluid damping material reciprocating through the gap between the piston and the cylinder and the damping hole on the piston, energy is dissipated due to overcoming factors such as friction and collision.

[0023] Furthermore, the sliding piston, which is loosely fitted onto the piston rod shaft, slides freely on the piston rod shaft without participating in the work when the displacement amplitude is less than or equal to A1, and only the fixed piston generates damping force.

[0024] Furthermore, the first sliding piston, which is loosely fitted onto the piston rod shaft, participates in the work of part of the displacement segment after the displacement amplitude is greater than A1 due to the restriction of the shaft shoulder and the piston positioning ring. Therefore, in part of the displacement segment, the damping force is generated jointly by the fixed piston and the first sliding piston.

[0025] Furthermore, the nth sliding piston, which is loosely fitted onto the piston rod shaft, has a displacement amplitude greater than A. n Later, due to the restriction of the piston positioning rings at both ends, it participates in the work of part of the displacement segment. Therefore, in part of the displacement segment, the damping force is generated by the fixed piston and n sliding pistons together.

[0026] Furthermore, guide sleeves are provided at the concentric inner holes connecting the sliding piston and the piston rod to position and guide the sliding piston and reduce sliding resistance.

[0027] Furthermore, piston seals are provided at the concentric inner holes connecting the sliding piston and the piston rod to provide a seal between the sliding piston and the piston rod after the sliding piston is limited, preventing the viscous fluid damping material from leaking from the high-pressure chamber into the low-pressure chamber through the gap between the piston and the piston rod.

[0028] Furthermore, guide sleeves and piston rod seals are provided at the connection points between the first and second bushings and the piston rod.

[0029] Furthermore, both the first and second bushings are provided with static bushing seals at the connection points with the cylinder.

[0030] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0031] This invention provides a multi-stage damping viscous damper that applies different damping forces in stages according to the displacement by using a fixed piston and multiple sliding pistons working in stages. This achieves a stepwise increase in damping force as the displacement increases, effectively adding an additional stiffness to the hysteresis curves under moderate, large, and rare earthquakes. This improves the damper's displacement control capability under these conditions, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations, moderate energy consumption with low additional stiffness and moderate damping force under moderate earthquakes, and high energy consumption with high additional stiffness and high damping force under large and rare earthquakes. This protects the main structure from damage by improving both strength and stiffness. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a multi-stage damping force viscous damper structure according to the present invention;

[0033] Figure 2 This is a schematic diagram of a single sliding piston structure of a multi-stage damping force viscous damper according to the present invention.

[0034] Figure 3 This is a schematic diagram of the operation of a multi-stage damping force viscous damper in the tensile state when the displacement amplitude is equal to A1.

[0035] Figure 4 This is a schematic diagram of the operation of a multi-stage damping force viscous damper in compression state when the displacement amplitude is equal to A1.

[0036] Figure 5 This is a hysteresis curve of a multi-stage damping force viscous damper of the present invention when the displacement amplitude is less than or equal to A1.

[0037] Figure 6 This is a schematic diagram of the operation of a multi-stage damping force viscous damper in the tensile state when the displacement amplitude is equal to A2.

[0038] Figure 7 This is a schematic diagram of the operation of a multi-stage damping force viscous damper in compression state when the displacement amplitude is equal to A2.

[0039] Figure 8 This is a hysteresis curve of a multi-stage damping force viscous damper of the present invention when the displacement amplitude is less than or equal to A2.

[0040] Figure 9 This is a schematic diagram of the operation of a multi-stage damping force viscous damper in the tensile state when the displacement amplitude is greater than A2.

[0041] Figure 10 This is a schematic diagram of the operation of a multi-stage damping force viscous damper in compression state when the displacement amplitude is greater than A2.

[0042] Figure 11 This is a hysteresis curve of a multi-stage damping force viscous damper of the present invention when the displacement amplitude is greater than A2;

[0043] Figure 12 This is a schematic diagram of the piston positioning ring structure of a multi-stage damping force viscous damper according to the present invention.

[0044] In the figure: 1-Pin head, 2-Piston rod, 3-Threaded pressure tube, 4-First bushing, 4.1-Guide sleeve, 4.2-Bushing static seal, 4.3-Piston rod seal, 5-Fixed piston, 6-Cylinder, 7a-Single sliding piston, 7-First sliding piston, 7.1-Piston guide sleeve, 7.2-Piston seal, 8-Second sliding piston, 9-Second bushing, 10-Ear plate, 11-Piston positioning ring, 11.1-Screw, 12-Viscous fluid damping material. Detailed Implementation

[0045] like Figure 1-12 To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] Example 1

[0047] A multi-stage damping viscous damper includes a first bushing 4 and a second bushing 9 placed at both ends of a cylinder 6 to form a sealed chamber inside the cylinder 6; a threaded pressure tube 3 and an ear plate 10 screwed to the cylinder 6 and used to fix the first bushing 4 and the second bushing 9 to the cylinder 6; a piston rod 2 passing through the central inner hole of the first bushing 4 and the second bushing 9; a pin head 1 disposed outside the damper cylinder 6 and fixed to the end of the piston rod 2; and a viscous fluid damping material 12 filling the damping chamber. The characteristic feature is that a fixed piston 5, which is fixed to the piston rod 2, and a single sliding piston 7a (only one sliding piston is provided in this embodiment) loosely fitted on the shaft of the piston rod 2 inside the cylinder 6 are provided. A piston positioning ring 11 is provided between the single sliding piston 7a and the second bushing 9. When the displacement is 0, the distance from the end face of the piston locating ring 11 between the single sliding piston 7a and the second bushing 9 to the end face of the second bushing 9 is the limit displacement U0 of the damper. The end face of the single sliding piston 7a and the piston rod shoulder maintain a distance A1, and the end face of the single sliding piston 7a and the piston locating ring 11 maintain a distance A1, and A1 is less than the limit displacement U0. The connection between the first bushing 4 and the second bushing 9 and the piston rod 2 is provided with a guide sleeve 4.1 and a piston rod seal 4.3. The connection between the first bushing 4 and the second bushing 9 and the cylinder 6 is provided with a bushing static seal 4.2. The piston locating ring 11 adopts a split structure and is fixed to the locating groove on the piston rod 2 after being closed with screws 11.1.

[0048] A guide sleeve 7.1 is provided at the concentric inner hole where the single sliding piston 7a connects to the piston rod 2. This guide sleeve is used for positioning and sliding guidance of the single sliding piston 7a and to reduce sliding resistance.

[0049] A piston seal 7.2 is provided at the concentric inner hole connecting the single sliding piston 7a and the piston rod 2. After the piston rod 2 shaft head or the piston positioning ring 11 presses against the single sliding piston 7a, a seal is provided between the single sliding piston 7a and the piston rod 2 to prevent the viscous fluid damping material 12 from leaking from the high-pressure chamber through the gap between the single sliding piston 7a and the piston rod 2 into the low-pressure chamber.

[0050] The piston rod 2 has a shaft head with a width of B1 between the fixed piston 5 and the single sliding piston 7a, ensuring that the distance between the end face of the fixed piston 5 and the end face of the single sliding piston 7a is always greater than or equal to B1, and the width of B1 is not less than half of the width B of the fixed piston 5, so as to ensure that the damping coefficient C1 and damping index α1 of the fixed piston 5 do not change under any state.

[0051] The fixed piston 5 and the single sliding piston 7a have the same outer diameter, width, and the same diameter and number of damping holes, so that the fixed piston 5 and the single sliding piston 7a have the same damping coefficient and damping index, which is conducive to the parameter design of the damper and saves the design and testing costs.

[0052] The sealed chamber inside the cylinder 6 is filled with viscous fluid damping material 12. A gap is left between the outer cylindrical surface of the piston and the inner wall of the cylinder 6, and a damping hole is provided on the piston. When the viscous damper is working, as the piston reciprocates relative to the cylinder 6, the viscous fluid damping material 12 flows from the high-pressure chamber through the gap between the piston and the cylinder 6 and the damping hole on the piston to the low-pressure chamber. During the process of the viscous fluid damping material 12 reciprocating through the gap between the piston and the cylinder 6 and the damping hole on the piston, energy is dissipated due to overcoming factors such as friction and collision.

[0053] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is less than or equal to A1, the single sliding piston 7a, which is loosely fitted onto the piston rod 2 shaft, remains in a free sliding state and does not participate in the work. Only the fixed piston 5 generates a damping force. At this point, the damper only provides additional damping without providing additional stiffness, making the structure more flexible. Thus, while reducing seismic response, the principle of using additional damping to strengthen the structure is utilized. By increasing the additional damping ratio, higher performance goals are achieved while reducing the amount of steel used in the main structure and lowering the cost.

[0054] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude exceeds A1, the single sliding piston 7a is restricted by the piston positioning ring 11 and the shaft end on the piston rod 2, causing it to participate in the work of part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5 and the single sliding piston 7a jointly generate damping force. During the compression process of the damper, the damping force in the displacement segment from -U to -(U-2A1) is... Displacement - (U-2A1) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to (U-2A1) Displacement (U-2A1) to damping force in segment -U Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the single sliding piston 7a, α1 is the damping index of the fixed piston 5, α2 is the damping index of the single sliding piston 7a, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the single sliding piston 7a, and υ is the velocity at the displacement point. During this process, while providing additional damping, the damper applies different damping forces in stages according to the displacement magnitude through the phased operation of the fixed piston 5 and the single sliding piston 7a. This achieves a stepwise increase in damping force with increasing displacement, effectively providing an additional stiffness equivalent to the hysteresis curve under moderate, large, and rare earthquakes. This improves the damper's displacement control capability under moderate, large, and rare earthquakes, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations, and high energy consumption with high additional stiffness and high damping force under moderate, large, and rare earthquakes. This protects the main structure from damage by improving both strength and stiffness.

[0055] Example 2

[0056] A multi-stage damping viscous damper includes a first bushing 4 and a second bushing 9 placed at both ends of a cylinder 6 to form a sealed chamber inside the cylinder 6; a threaded pressure tube 3 and an ear plate 10 screwed to the cylinder 6 and used to fix the first bushing 4 and the second bushing 9 to the cylinder 6; a piston rod 2 passing through the central inner hole of the first bushing 4 and the second bushing 9; a pin head 1 fixed to the end of the piston rod 2 and disposed outside the damper cylinder 6; and a viscous fluid damping material 12 filling the damping chamber. The characteristic feature is that a fixed piston 5, which is fixed to the piston rod 2, and a first sliding piston 7 and a second sliding piston 8 (in this embodiment, two sliding pistons) are sequentially loosely fitted onto the piston rod 2's shaft. A piston positioning ring 11 is provided between the first sliding piston 7 and the second sliding piston 8, and between the second sliding piston 8 and the second bushing 9. When the fixed piston 5 is at displacement 0, the distance from its end face near the first bushing 4 to the end face of the first bushing 4 is the limit displacement U0 of the damper. The distance from the end face of the piston positioning ring 11 between the second sliding piston 8 and the second bushing 9 to the end face of the second bushing 9 is the limit displacement U0 of the damper. The end face of the first sliding piston 7 maintains a distance A1 from the shoulder of the piston rod 2. The end face of the piston positioning ring 11 between the first sliding piston 7 and the second sliding piston 8 maintains a distance A1 from the end face of the first sliding piston 7. The end face of the piston positioning ring 11 between the first sliding piston 7 and the second sliding piston 8 maintains a distance A2 from the end face of the second sliding piston 8. The end face of the piston positioning ring 11 between the second sliding piston 8 and the second bushing 9 maintains a distance A2 from the end face of the second sliding piston 8. A1 is less than A2 and A2 is less than the limit displacement U0. A guide sleeve 4.1 and a piston rod seal 4.3 are provided at the connection between the first bushing 4 and the second bushing 9 and the piston rod 2. A bushing static seal 4.2 is provided at the connection between the first bushing 4 and the second bushing 9 and the cylinder 6. The piston positioning ring 11 adopts a split structure and is fixed to the positioning groove on the piston rod 2 after being closed with screws 11.1.

[0057] Guide sleeves 7.1 are provided at the concentric inner holes where the first sliding piston 7 and the second sliding piston 8 are connected to the piston rod 2. These sleeves are used for positioning and sliding guidance of the first sliding piston 7 and the second sliding piston 8, and to reduce sliding resistance.

[0058] Piston seals 7.2 are provided at the concentric inner holes where the first sliding piston 7 and the second sliding piston 8 are connected to the piston rod 2. These seals are used to provide a seal between the first sliding piston 7 and the second sliding piston 8 and the piston rod 2 after the first sliding piston 7 and the second sliding piston 8 are limited, so as to prevent the viscous fluid damping material 12 from leaking from the high-pressure chamber through the gap between it and the piston rod 2 into the low-pressure chamber.

[0059] The piston rod 2 has a shaft head with a width of B1 between the fixed piston 5 and the first sliding piston 7, ensuring that the distance between the end face of the fixed piston 5 and the end face of the first sliding piston 7 is always greater than or equal to B1, and the width of B1 is not less than half of the width B of the fixed piston 5, so as to ensure that the damping coefficient C1 and damping index α1 of the fixed piston 5 do not change under any state.

[0060] The fixed piston 5 has the same outer diameter, width, damping hole diameter and number as the first sliding piston 7 and the second sliding piston 8, so that the fixed piston 5 has the same damping coefficient and damping index as the first sliding piston 7 and the second sliding piston 8, which is conducive to the parameter design of the damper and saves the design test cost.

[0061] The sealed chamber inside the cylinder 6 is filled with viscous fluid damping material 12. A gap is left between the outer cylindrical surface of the piston and the inner wall of the cylinder 6, and a damping hole is provided on the piston. When the viscous damper is working, as the piston reciprocates relative to the cylinder 6, the viscous fluid damping material 12 flows from the high-pressure chamber through the gap between the piston and the cylinder 6 and the damping hole on the piston to the low-pressure chamber. During the process of the viscous fluid damping material 12 reciprocating through the gap between the piston and the cylinder 6 and the damping hole on the piston, energy is dissipated due to overcoming factors such as friction and collision.

[0062] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is less than or equal to A1, the first sliding piston 7 and the second sliding piston 8, which are loosely fitted onto the piston rod 2 shaft, remain in a free sliding state and do not participate in the work. Only the fixed piston 5 generates a damping force. At this point, the damper only provides additional damping without providing additional stiffness, making the structure more flexible. Thus, while reducing seismic response, the principle of using additional damping to strengthen the structure is utilized. By increasing the additional damping ratio, higher performance goals are achieved while reducing the amount of steel used in the main structure and lowering the cost.

[0063] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is greater than A1 and less than or equal to A2, the first sliding piston 7's free-slip amplitude is limited by the piston positioning ring 11 and the shaft end on the piston rod 2, causing it to participate in the work of part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5 and the first sliding piston 7 jointly generate damping force. During the damper compression process, the damping force in the displacement segment from -U to -(U-2A1) is... Displacement - (U-2A1) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to (U-2A1) Displacement (U-2A1) to damping force in segment -U Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the first sliding piston 7, α1 is the damping index of the fixed piston 5, α2 is the damping index of the first sliding piston 7, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the first sliding piston 7, and υ is the velocity of the displacement point.

[0064] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is greater than A2, in addition to the first sliding piston 7 participating in part of the displacement segment, the piston positioning rings 11 at both ends of the second sliding piston 8 limit the free sliding amplitude of the second sliding piston 8, causing it to also participate in part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5, the first sliding piston 7, and the second sliding piston 8 jointly generate damping force. During the compression process of the damper, the damping force in the displacement segment from -U to -(U-2A1) is... Damping force in the displacement segment from (U-2A1) to (U-2A2) Displacement - (U-2A2) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to U-2A1. Damping force in the displacement segment U-2A1 to U-2A2 Damping force in the displacement U-2A2 to -U segment Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the first sliding piston 7, C3 is the damping coefficient of the second sliding piston 8, α1 is the damping index of the fixed piston 5, α2 is the damping index of the first sliding piston 7, α3 is the damping index of the second sliding piston 8, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the first sliding piston 7, A2 is the set sliding displacement amplitude of the second sliding piston 8, and υ is the velocity at the displacement point.

[0065] During this process, while providing additional damping, the damper applies different damping forces in stages according to the displacement magnitude through the phased operation of the fixed piston 5, the first sliding piston 7, and the second sliding piston 8. This achieves a step-like gradual increase in damping force as the displacement increases, effectively providing an additional stiffness equivalent to the hysteresis curve under moderate, large, and rare earthquakes. This enhances the damper's displacement control capability under moderate, large, and rare earthquakes, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations, moderate energy consumption with low additional stiffness and moderate damping force under moderate earthquakes, and high energy consumption with high additional stiffness and high damping force under large and rare earthquakes. This protects the main structure from damage by improving both strength and stiffness.

[0066] Example 3

[0067] A multi-stage damping viscous damper includes a first bushing 4 and a second bushing 9 placed at both ends of a cylinder 6 to form a sealed chamber inside the cylinder 6; a threaded pressure tube 3 and an ear plate 10 screwed to the cylinder 6 and used to fix the first bushing 4 and the second bushing 9 to the cylinder 6; a piston rod 2 passing through the central inner hole of the first bushing 4 and the second bushing 9; a pin head 1 fixed to the end of the piston rod 2 and disposed outside the damper cylinder 6; and a viscous fluid damping material 12 filling the damping chamber. The characteristic feature is that a fixed piston 5, which is fixed to the piston rod 2, and a first sliding piston 7 and a second sliding piston 8 (in this embodiment, two sliding pistons) are sequentially loosely fitted onto the piston rod 2's shaft. A piston positioning ring 11 is provided between the first sliding piston 7 and the second sliding piston 8, and between the second sliding piston 8 and the second bushing 9. When the fixed piston 5 is at displacement 0, the distance from its end face near the first bushing 4 to the end face of the first bushing 4 is the limit displacement U0 of the damper. The distance from the end face of the piston positioning ring 11 between the second sliding piston 8 and the second bushing 9 to the end face of the second bushing 9 is the limit displacement U0 of the damper. The end face of the first sliding piston 7 maintains a distance A1 from the shoulder of the piston rod 2. The end face of the piston positioning ring 11 between the first sliding piston 7 and the second sliding piston 8 maintains a distance A1 from the end face of the first sliding piston 7. The end face of the piston positioning ring 11 between the first sliding piston 7 and the second sliding piston 8 maintains a distance A2 from the end face of the second sliding piston 8. The end face of the piston positioning ring 11 between the second sliding piston 8 and the second bushing 9 maintains a distance A2 from the end face of the second sliding piston 8. A1 is less than A2 and A2 is less than the limit displacement U0. A guide sleeve 4.1 and a piston rod seal 4.3 are provided at the connection between the first bushing 4 and the second bushing 9 and the piston rod 2. A bushing static seal 4.2 is provided at the connection between the first bushing 4 and the second bushing 9 and the cylinder 6. The piston positioning ring 11 adopts a split structure and is fixed to the positioning groove on the piston rod 2 after being closed with screws 11.1.

[0068] Guide sleeves 7.1 are provided at the concentric inner holes where the first sliding piston 7 and the second sliding piston 8 are connected to the piston rod 2. These sleeves are used for positioning and sliding guidance of the first sliding piston 7 and the second sliding piston 8, and to reduce sliding resistance.

[0069] Piston seals 7.2 are provided at the concentric inner holes where the first sliding piston 7 and the second sliding piston 8 are connected to the piston rod 2. These seals are used to provide a seal between the first sliding piston 7 and the second sliding piston 8 and the piston rod 2 after the first sliding piston 7 and the second sliding piston 8 are limited, so as to prevent the viscous fluid damping material 12 from leaking from the high-pressure chamber through the gap between it and the piston rod 2 into the low-pressure chamber.

[0070] The piston rod 2 has a shaft head with a width of B1 between the fixed piston 5 and the first sliding piston 7, ensuring that the distance between the end face of the fixed piston 5 and the end face of the first sliding piston 7 is always greater than or equal to B1, and the width of B1 is not less than half of the width B of the fixed piston 5, so as to ensure that the damping coefficient C1 and damping index α1 of the fixed piston 5 do not change under any state.

[0071] The fixed piston 5 has the same outer diameter as the first sliding piston 7 and the second sliding piston 8, but their widths are not equal. The width of the second sliding piston 8 is greater than the width of the first sliding piston 7, and the width of the first sliding piston 7 is greater than the width of the fixed piston 5. By setting C3>C2>C1, the damping force variation gradient is increased, and a greater equivalent stiffness is obtained.

[0072] The fixed piston 5 has a different diameter than the damping hole on the first sliding piston 7 and the second sliding piston 8. The diameter of the damping hole on the second sliding piston 8 is larger than the diameter of the damping hole on the first sliding piston 7. The diameter of the damping hole on the first sliding piston 7 is larger than the diameter of the damping hole on the fixed piston 5, so that the fixed piston 5 has the same damping index as the first sliding piston 7 and the second sliding piston 8.

[0073] The sealed chamber inside the cylinder 6 is filled with viscous fluid damping material 12. A gap is left between the outer cylindrical surface of the piston and the inner wall of the cylinder 6, and a damping hole is provided on the piston. When the viscous damper is working, as the piston reciprocates relative to the cylinder 6, the viscous fluid damping material 12 flows from the high-pressure chamber through the gap between the piston and the cylinder 6 and the damping hole on the piston to the low-pressure chamber. During the process of the viscous fluid damping material 12 reciprocating through the gap between the piston and the cylinder 6 and the damping hole on the piston, energy is dissipated due to overcoming factors such as friction and collision.

[0074] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is less than or equal to A1, the first sliding piston 7 and the second sliding piston 8, which are loosely fitted onto the piston rod 2 shaft, remain in a free sliding state and do not participate in the work. Only the fixed piston 5 generates a damping force. At this point, the damper only provides additional damping without providing additional stiffness, making the structure more flexible. Thus, while reducing seismic response, the principle of using additional damping to strengthen the structure is utilized. By increasing the additional damping ratio, higher performance goals are achieved while reducing the amount of steel used in the main structure and lowering the cost.

[0075] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is greater than A1 and less than or equal to A2, the first sliding piston 7's free-slip amplitude is limited by the piston positioning ring 11 and the shaft end on the piston rod 2, causing it to participate in the work of part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5 and the first sliding piston 7 jointly generate damping force. During the damper compression process, the damping force in the displacement segment from -U to -(U-2A1) is... Displacement - (U-2A1) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to (U-2A1) Displacement (U-2A1) to damping force in segment -U Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the first sliding piston 7, α1 is the damping index of the fixed piston 5, α2 is the damping index of the first sliding piston 7, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the first sliding piston 7, and υ is the velocity of the displacement point.

[0076] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is greater than A2, in addition to the first sliding piston 7 participating in part of the displacement segment, the piston positioning rings 11 at both ends of the second sliding piston 8 limit the free sliding amplitude of the second sliding piston 8, causing it to also participate in part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5, the first sliding piston 7, and the second sliding piston 8 jointly generate damping force. During the compression process of the damper, the damping force in the displacement segment from -U to -(U-2A1) is... Damping force in the displacement segment from (U-2A1) to (U-2A2) Displacement - (U-2A2) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to U-2A1. Damping force in the displacement segment U-2A1 to U-2A2 Damping force in the displacement U-2A2 to -U segment Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the first sliding piston 7, C3 is the damping coefficient of the second sliding piston 8, α1 is the damping index of the fixed piston 5, α2 is the damping index of the first sliding piston 7, α3 is the damping index of the second sliding piston 8, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the first sliding piston 7, A2 is the set sliding displacement amplitude of the second sliding piston 8, and υ is the velocity at the displacement point.

[0077] During this process, while providing additional damping, the damper applies different damping forces in stages according to the displacement magnitude through the phased operation of the fixed piston 5, the first sliding piston 7, and the second sliding piston 8. This achieves a step-like gradual increase in damping force as the displacement increases, effectively providing an additional stiffness equivalent to the hysteresis curve under moderate, large, and rare earthquakes. This enhances the damper's displacement control capability under moderate, large, and rare earthquakes, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations, moderate energy consumption with low additional stiffness and moderate damping force under moderate earthquakes, and high energy consumption with high additional stiffness and high damping force under large and rare earthquakes. This protects the main structure from damage by improving both strength and stiffness.

[0078] Example 4

[0079] A multi-stage damping viscous damper includes a first bushing 4 and a second bushing 9 placed at both ends of a cylinder 6 to form a sealed chamber inside the cylinder 6; a threaded pressure tube 3 and an ear plate 10 screwed to the cylinder 6 and used to fix the first bushing 4 and the second bushing 9 to the cylinder 6; a piston rod 2 passing through the central inner hole of the first bushing 4 and the second bushing 9; a pin head 1 fixed to the end of the piston rod 2 and disposed outside the damper cylinder 6; and a viscous fluid damping material 12 filling the damping chamber. The characteristic feature is that a fixed piston 5, which is fixed to the piston rod 2, and a first sliding piston 7 and a second sliding piston 8 (in this embodiment, two sliding pistons) are sequentially loosely fitted onto the shaft of the piston rod 2. A piston positioning ring 11 is provided between the first sliding piston 7 and the second sliding piston 8, and between the second sliding piston 8 and the second bushing 9. When the fixed piston 5 is at displacement 0, the distance from its end face near the first bushing 4 to the end face of the first bushing 4 is the limit displacement U0 of the damper. The distance from the end face of the piston positioning ring 11 between the second sliding piston 8 and the second bushing 9 to the end face of the second bushing 9 is the limit displacement U0 of the damper. The end face of the first sliding piston 7 maintains a distance A1 from the shoulder of the piston rod 2. The end face of the piston positioning ring 11 between the first sliding piston 7 and the second sliding piston 8 maintains a distance A1 from the end face of the first sliding piston 7. The end face of the piston positioning ring 11 between the first sliding piston 7 and the second sliding piston 8 maintains a distance A2 from the end face of the second sliding piston 8. The end face of the piston positioning ring 11 between the second sliding piston 8 and the second bushing 9 maintains a distance A2 from the end face of the second sliding piston 8. A1 is less than A2 and A2 is less than the limit displacement U0. A guide sleeve 4.1 and a piston rod seal 4.3 are provided at the connection between the first bushing 4 and the second bushing 9 and the piston rod 2. A bushing static seal 4.2 is provided at the connection between the first bushing 4 and the second bushing 9 and the cylinder 6. The piston positioning ring 11 adopts a split structure and is fixed to the positioning groove on the piston rod 2 after being closed with screws 11.1.

[0080] Guide sleeves 7.1 are provided at the concentric inner holes where the first sliding piston 7 and the second sliding piston 8 are connected to the piston rod 2. These sleeves are used for positioning and sliding guidance of the first sliding piston 7 and the second sliding piston 8, and to reduce sliding resistance.

[0081] Piston seals 7.2 are provided at the concentric inner holes where the first sliding piston 7 and the second sliding piston 8 are connected to the piston rod 2. These seals are used to provide a seal between the first sliding piston 7 and the second sliding piston 8 and the piston rod 2 after the first sliding piston 7 and the second sliding piston 8 are limited, so as to prevent the viscous fluid damping material 12 from leaking from the high-pressure chamber through the gap between it and the piston rod 2 into the low-pressure chamber.

[0082] The piston rod 2 has a shaft head with a width of B1 between the fixed piston 5 and the first sliding piston 7, ensuring that the distance between the end face of the fixed piston 5 and the end face of the first sliding piston 7 is always greater than or equal to B1, and the width of B1 is not less than half of the width B of the fixed piston 5, so as to ensure that the damping coefficient C1 and damping index α1 of the fixed piston 5 do not change under any state.

[0083] The diameter and width of the second sliding piston 8 are both greater than the diameter and width of the first sliding piston 7, and the diameter and width of the first sliding piston 7 are both greater than the diameter and width of the fixed piston 5. This increases the damping force gradient and achieves greater equivalent stiffness.

[0084] The damping hole diameters on the fixed piston 5, the first sliding piston 7, and the second sliding piston 8 are not equal, and the damping hole diameter on the second sliding piston 8 is larger than the damping hole diameter on the first sliding piston 7. The damping hole diameter on the first sliding piston 7 is larger than the damping hole diameter on the fixed piston 5. Let α3>α2>α1 to increase the damping force variation gradient and obtain a larger equivalent stiffness.

[0085] The sealed chamber inside the cylinder 6 is filled with viscous fluid damping material 12. A gap is left between the outer cylindrical surface of the piston and the inner wall of the cylinder 6, and a damping hole is provided on the piston. When the viscous damper is working, as the piston reciprocates relative to the cylinder 6, the viscous fluid damping material 12 flows from the high-pressure chamber through the gap between the piston and the cylinder 6 and the damping hole on the piston to the low-pressure chamber. During the process of the viscous fluid damping material 12 reciprocating through the gap between the piston and the cylinder 6 and the damping hole on the piston, energy is dissipated due to overcoming factors such as friction and collision.

[0086] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is less than or equal to A1, the first sliding piston 7 and the second sliding piston 8, which are loosely fitted onto the piston rod 2 shaft, remain in a free sliding state and do not participate in the work. Only the fixed piston 5 generates a damping force. At this point, the damper only provides additional damping without providing additional stiffness, making the structure more flexible. Thus, while reducing seismic response, the principle of using additional damping to strengthen the structure is utilized. By increasing the additional damping ratio, higher performance goals are achieved while reducing the amount of steel used in the main structure and lowering the cost.

[0087] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is greater than A1 and less than or equal to A2, the first sliding piston 7's free-slip amplitude is limited by the piston positioning ring 11 and the shaft end on the piston rod 2, causing it to participate in the work of part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5 and the first sliding piston 7 jointly generate damping force. During the damper compression process, the damping force in the displacement segment from -U to -(U-2A1) is... Displacement - (U-2A1) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to (U-2A1) Displacement (U-2A1) to damping force in segment -U Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the first sliding piston 7, α1 is the damping index of the fixed piston 5, α2 is the damping index of the first sliding piston 7, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the first sliding piston 7, and υ is the velocity of the displacement point.

[0088] During the reciprocating motion of the fixed piston 5 relative to the cylinder 6, when the displacement amplitude is greater than A2, in addition to the first sliding piston 7 participating in part of the displacement segment, the piston positioning rings 11 at both ends of the second sliding piston 8 limit the free sliding amplitude of the second sliding piston 8, causing it to also participate in part of the displacement segment. Therefore, in part of the displacement segment, the fixed piston 5, the first sliding piston 7, and the second sliding piston 8 jointly generate damping force. During the compression process of the damper, the damping force in the displacement segment from -U to -(U-2A1) is... Damping force in the displacement segment from (U-2A1) to (U-2A2) Displacement - (U-2A2) to U-segment damping force Damping force during the stretching process of the damper, from displacement U to U-2A1. Damping force in the displacement segment U-2A1 to U-2A2 Damping force in the displacement U-2A2 to -U segment Where C1 is the damping coefficient of the fixed piston 5, C2 is the damping coefficient of the first sliding piston 7, C3 is the damping coefficient of the second sliding piston 8, α1 is the damping index of the fixed piston 5, α2 is the damping index of the first sliding piston 7, α3 is the damping index of the second sliding piston 8, U is the displacement amplitude of the damper, A1 is the set sliding displacement amplitude of the first sliding piston 7, A2 is the set sliding displacement amplitude of the second sliding piston 8, and υ is the velocity at the displacement point.

[0089] During this process, while providing additional damping, the damper applies different damping forces in stages according to the displacement magnitude through the phased operation of the fixed piston 5, the first sliding piston 7, and the second sliding piston 8. This achieves a step-like gradual increase in damping force as the displacement increases, effectively providing an additional stiffness equivalent to the hysteresis curve under moderate, large, and rare earthquakes. This enhances the damper's displacement control capability under moderate, large, and rare earthquakes, achieving low energy consumption with low damping force and no additional stiffness under minor earthquakes and wind-induced vibrations, moderate energy consumption with low additional stiffness and moderate damping force under moderate earthquakes, and high energy consumption with high additional stiffness and high damping force under large and rare earthquakes. This protects the main structure from damage by improving both strength and stiffness.

[0090] Although the invention has been described herein with reference to several illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter arrangement within the scope of the disclosure, drawings, and claims. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A multi-stage damping force viscous damper, comprising a first bushing (4) and a second bushing (9) placed at both ends of a cylinder (6) to form a sealed chamber inside the cylinder (6), a threaded pressure tube (3) screwed to the cylinder (6) and used to fix the first bushing (4) and the second bushing (9) to the cylinder (6), a piston rod (2) passing through the central inner hole of the first bushing (4) and the second bushing (9), a pin (1) disposed outside the damper cylinder (6) and fixed to the end of the piston rod (2), and a viscous fluid damping material (12) filling the damping chamber, characterized in that: The piston rod (2) is placed inside the cylinder (6) and has a fixed piston (5) fixed to the piston rod (2) and a sliding piston loosely fitted on the piston rod (2) shaft. There are one or more sliding pistons. A piston positioning ring (11) is provided between adjacent sliding pistons and between the last sliding piston and the second bushing (9). The piston positioning ring (11) adopts a split structure and is fixed to the positioning groove on the piston rod (2) after being closed with screws (11.1). A shaft head with a width of B1 is provided between the fixed piston (5) and the first sliding piston (7). A guide sleeve (7.1) and a piston seal (7.2) are provided at the concentric inner hole where the sliding piston connects to the piston rod (2). When the fixed piston (5) is at displacement 0, the distance from the end face of the fixed piston (5) closest to the first bushing (4) to the end face of the first bushing (4) is the limit displacement U0 of the damper. The distance from the end face of the piston positioning ring (11) between the last sliding piston and the second bushing (9) to the end face of the second bushing (9) is the limit displacement U0 of the damper. The end face of the first sliding piston (7) maintains a distance A1 from the shoulder of the piston rod (2). The end face of the piston positioning ring (11) between the first sliding piston (7) and the next sliding piston maintains a distance A1 from the end face of the first sliding piston (7). The end face of the piston positioning ring (11) between the next sliding piston and the previous sliding piston maintains a distance A from the end face of the sliding piston. n The other end face of the sliding piston maintains a distance A from the end face of the next piston positioning ring (11). n And A1 is less than A n-1 A n-1 Less than A n A n Less than the limit displacement U0; The theoretical damping force calculation formula for a damper is: when the displacement amplitude is less than or equal to A. When the displacement amplitude is greater than A1 and less than or equal to A2, the displacement during the damper compression process is from -U to -(U-2A1). Displacement - (U-2A1) to segment U During the damper's stretching process, the displacement U reaches the (U-2A1) segment. Displacement (U-2A1) to segment -U When the displacement amplitude is greater than A2 and less than or equal to A3, the displacement during the damper compression process is from -U to -(U-2A1). Displacement from -(U-2A1) to -(U-2A2) segment Displacement - (U-2A2) to segment U During the damper's stretching process, the displacement U to U-2A1 segment Displacement segment U-2A1 to U-2A2 Displacement U-2A2 to -U segment When the displacement amplitude is greater than A3 and less than or equal to A n During the damper compression process, the displacement ranges from -U to -(U-2A1). Displacement from -(U-2A1) to -(U-2A2) segment Displacement - (U-2A) n-1 ) to -(U-2A n )part Displacement - (U-2A) n (to U segment) During the damper's stretching process, the displacement U to U-2A1 segment Displacement segment U-2A1 to U-2A2 Displacement (U-2A) n-1 ) to U-2A n part Displacement U-2A n to -U segment Where C1 is the damping coefficient of the fixed piston (5), C2 is the damping coefficient of the first sliding piston (7), C3 is the damping coefficient of the second sliding piston (8), and C... n C is the damping coefficient of the (n-1)th sliding piston. n+1 Let α be the damping coefficient of the nth sliding piston, α1 be the damping index of the fixed piston (5), α2 be the damping index of the first sliding piston (7), and α3 be the damping index of the second sliding piston (8). n Let α be the damping exponent of the (n-1)th sliding piston. n+1 Let U be the damping index of the nth sliding piston, U be the displacement amplitude of the damper, A1 be the set sliding displacement amplitude of the first sliding piston (7), A2 be the set sliding displacement amplitude of the second sliding piston (8), A3 be the set sliding displacement amplitude of the third sliding piston, and A... n Let υ be the set sliding displacement amplitude of the nth sliding piston, and υ be the velocity at the displacement point. The damping coefficient C1 of the fixed piston (5), the damping coefficient C2 of the first sliding piston (7), the damping coefficient C3 of the second sliding piston (8), and the damping coefficient C of the nth sliding piston. n+1 They can be equal or unequal; the damping index α1 of the fixed piston (5), the damping index α2 of the first sliding piston (7), the damping index α3 of the second sliding piston (8), and the damping index α of the nth sliding piston. n+1 The outer diameters of the fixed piston (5), the first sliding piston (7), the second sliding piston (8), and the nth sliding piston can be equal or unequal. The widths of the fixed piston (5), the first sliding piston (7), the second sliding piston (8), and the nth sliding piston can be equal or unequal; The damping holes on the fixed piston (5), the first sliding piston (7), the second sliding piston (8), and the nth sliding piston can be of equal or unequal size.

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