A viscous damper with fire-resistant function

Abstract

A viscous damper with fire-resistant function includes a piston rod, a piston head, a damping orifice, a damping medium containing phase change particles, a main cylinder, a secondary cylinder, a high-temperature resistant sealing ring, a high-temperature resistant spring, and a retractable fireproof cover. A damping orifice is formed on the piston head, and the piston rod is connected to the piston head. The piston rod and piston head surround the main cylinder and the secondary cylinder. The main cylinder is filled with the damping medium containing phase change particles. The phase change material particles undergo a phase change from solid to liquid at high temperatures, absorbing a large amount of heat. The secondary cylinder contains no damping material. One end of the high-temperature resistant spring is welded to the piston rod end, and the other end is welded to the inner wall of the secondary cylinder. The high-temperature resistant sealing ring is installed inside the main cylinder end cap, contacting the piston rod surface. A head connector is connected to the piston rod end, and a tail connector is connected to the secondary cylinder end. One end of the retractable fireproof cover is bolted to the head connector, and the other end is bolted to the main cylinder end cap.

Description

Technical Field

[0001] This utility model relates to the field of building structure vibration reduction technology, specifically to a viscous damper with fireproof function, which is particularly suitable for viscous dampers that need to maintain normal working performance in fire environments. Background Technology

[0002] Viscous dampers are widely used vibration reduction devices in engineering structures such as buildings and bridges. A viscous damper mainly consists of a piston, piston rod, silicone oil, cylinder, and left and right lugs. It achieves vibration reduction and energy dissipation by relying on the damping force generated when fluid damping material passes through damping orifices (or gaps) during relative motion between the piston and cylinder. However, traditional viscous dampers have significant performance defects in fire environments, especially under extreme conditions of fire and earthquake coupling, where their safety and reliability face severe challenges. Increased temperature usually leads to a decrease in the viscosity of the viscous damper, thereby reducing the damping coefficient and maximum output force. High temperatures can also adversely affect the damper's sealing system, leading to performance degradation. In traditional viscous dampers, the piston rod is partially exposed to the external environment when pulled out. During a fire, high temperatures directly act on the exposed piston rod, causing a sharp decrease in its material strength, and even softening and deformation, thus affecting the overall performance of the damper.

[0003] Currently, most fire protection measures for viscous dampers involve externally wrapping them with fire-resistant materials. While this method can mitigate the effects of high temperatures on the damper to some extent, it primarily focuses on protecting the cylinder body and fails to adequately address the exposure of the piston rod in a fire. Because the piston rod needs to frequently extend and retract during damper operation, its exposed portion is highly susceptible to direct exposure to high temperatures in a fire, leading to material degradation and even failure. This design flaw significantly reduces the performance of traditional viscous dampers in fire environments, especially under the combined effects of fire and shock, where piston rod failure can further exacerbate the risk of structural damage. Although some improvement schemes attempt to enhance the fire resistance of the damper by adding an external fire-resistant layer or using high-temperature resistant materials, or by adding a protective cover to the piston rod, these measures often fail to address the piston rod's exposure to fire and can affect the fire protection layout of the cylinder body. Therefore, there is an urgent need for a simple, reliable fire-resistant modification scheme to improve the performance of viscous dampers in fire environments. Utility Model Content

[0004] To address some problems existing in the prior art, the purpose of this utility model is to provide a viscous damper with fire-resistant function. By improving the structure, the piston rod is prevented from being directly exposed to the high-temperature environment in a fire, and the internal structure is optimized, thereby improving the working performance and safety of the damper under the coupled action of fire and earthquake.

[0005] To achieve the above objectives, this utility model provides a viscous damper with fire-resistant function. The viscous damper includes a piston rod, a piston head, a damping orifice, a damping medium containing phase change particles, a main cylinder, a secondary cylinder, and a high-temperature resistant sealing ring. The damping orifice is located on the piston head, and the piston rod is connected to the piston head. The piston rod and piston head surround the main cylinder and the secondary cylinder. The main cylinder is filled with damping medium, while the secondary cylinder contains no damping material. One end of a high-temperature resistant spring is welded to the piston rod end, and the other end is welded to the inner wall of the secondary cylinder. Movement of the piston rod causes the damping medium containing phase change particles in the main cylinder to pass through the damping orifice, generating damping force. The high-temperature resistant sealing ring is installed on the inner side of the main cylinder end cap, contacting the piston rod surface. A head connector is connected to the piston rod end, and a tail connector is connected to the secondary cylinder end. One end of a retractable fireproof cover is connected to the head connector by bolts, and the other end is connected to the main cylinder end cap by end cap bolts. Insert the pin into the self-lubricating radial spherical bearing of the connector, thus connecting the viscous damper to the connector. Finally, connect the connector to the wall using the anchoring assembly.

[0006] In this technical solution, the retractable fireproof cover is a galvanized sleeve with a thickness of 1.0-1.5 mm, which is fixed around the piston rod with bolts. In the event of a fire, it can protect the piston rod and prevent it from being directly exposed to the fire.

[0007] In this technical solution, the retractable fireproof cover is not connected to the main cylinder body, but is fixed to the main cylinder end cover. This is beneficial for the application of the external fireproof coating of the viscous damper, and will not affect the surface coating during operation.

[0008] As an improvement of this utility model, the retractable fireproof cover has a double-layer structure, including an outer fireproof cover, a middle layer of phase change material, and an inner fireproof cover. The phase change material of the middle layer of the retractable fireproof cover is paraffin wax, which undergoes a phase change from solid to liquid at high temperatures, absorbing a large amount of heat.

[0009] In this technical solution, the high-temperature resistant spring material is heat-resistant spring steel, which has a high stiffness coefficient and can be used in environments above 300℃. The high-temperature resistant spring provides a restoring force when the piston rod extends or retracts, and compensates for the thermal expansion displacement of the piston rod through elastic deformation in a fire environment.

[0010] As another improvement of this utility model, the damping medium containing phase change particles contains phase change material particles, the phase change material is paraffin, and the particle size range is 10-100 μm. The phase change material particles undergo a phase change from solid to liquid at high temperature, absorb a large amount of heat, reduce the temperature fluctuation of the damping medium, and maintain its viscosity stability.

[0011] In this technical solution, the sealing ring is a high-temperature resistant sealing ring, which is made of polytetrafluoroethylene (PTFE) coated stainless steel spring, with a temperature resistance range of -50°C to 300°C.

[0012] In this technical solution, the outer surface of the main cylinder is coated with a fire-retardant coating with a thickness of 1.0-2.0 mm; the fire-retardant coating expands at high temperature to form a porous heat insulation layer, reducing thermal conductivity. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of a viscous damper;

[0014] Figure 2 This is a front view of a viscous damper;

[0015] Figure 3 This is a top view of a viscous damper;

[0016] Figure 4 This is a schematic diagram of a viscous damper after stretching;

[0017] Figure 5 This is a 1-1 cross-sectional view of the viscous damper;

[0018] Figure 6 This is a 2-2 cross-sectional view of the viscous damper.

[0019] In the diagram: The viscous damper includes 1. Piston rod, 2. Piston head, 3. Damping orifice, 4. Damping medium containing phase change particles, 5. Main cylinder, 6. Auxiliary cylinder, 7. High-temperature resistant sealing ring, 8. High-temperature resistant spring, 9. Main cylinder end cap, 10. Head connector, 11. Tail connector, 12. Telescopic fireproof cover, 13. Bolt, 14. End cap bolt, 15. Connecting seat, 16. Pin, 17. Self-lubricating radial spherical bearing, 18. Anchoring assembly, 19. Wall, 20. Intermediate phase change material, 21. Outer fireproof cover, 22. Inner fireproof cover. Detailed Implementation

[0020] An embodiment of the present invention will be further described below with reference to the accompanying drawings:

[0021] like Figures 1 to 6As shown, a viscous damper with fire-resistant function includes a piston rod 1, a piston head 2, a damping orifice 3, a damping medium 4 containing phase change particles, a main cylinder 5, a secondary cylinder 6, and a high-temperature resistant sealing ring 7. The damping orifice 3 is located on the piston head 2, and the piston rod 1 is connected to the piston head 2. The piston rod 1 and piston head 2 surround the main cylinder 5 and the secondary cylinder 6. The main cylinder 5 is filled with the damping medium 4 containing phase change particles, while the secondary cylinder 6 contains no damping material. One end of a high-temperature resistant spring 8 is welded to the end of the piston rod 1, and the other end is welded to the inner wall of the secondary cylinder 6. The movement of the piston rod 1 causes the damping medium 4 containing phase change particles in the main cylinder 5 to pass through the damping orifice 3, generating a damping force. The high-temperature resistant sealing ring 7 is installed on the inner side of the main cylinder end cap 9 and contacts the surface of the piston rod 1. A head connector 10 is connected to the end of the piston rod 1, and a tail connector 11 is connected to the end of the secondary cylinder 6. One end of the retractable fireproof cover 12 is connected to the head connector 10 via bolt 13, and the other end is connected to the main cylinder end cover 9 via end cover bolt 14. A pin 16 is inserted into the self-lubricating radial spherical bearing 17 of the connecting seat 15, connecting the viscous damper to the connecting seat 15. Finally, the connecting seat 15 is connected to the wall 19 via the anchoring assembly 18.

[0022] A calculation model for the damping force of a viscous damper is established based on the constitutive relation of a power-law fluid. The viscous damping force F provided by the viscous damper is... C It is related to the relative velocity V of the piston. For a viscous damper with damping coefficient C and damping exponent α, the magnitude of its damping force is F. C =CV ɑ After a horizontal force is applied to the damper, not only does the damping medium absorb the horizontal force generated by the external earthquake or wind load, but due to the presence of the high-temperature spring, the elastic deformation of the spring can also generate an elastic force F. k For a spring with stiffness coefficient k, if a relative deformation of u occurs, the resulting elastic force F k =ku. When the viscous damper is working, the total resistance F is the viscous damping force F. C With elastic force F k The resultant force: F = F C +F k =CV ɑ +ku.

[0023] In an example, the damping force under seismic loading is calculated as follows:

[0024] Assume the damping coefficient C of the viscous damper is 500 N / (m / s). a The damping index α is 0.5. Under seismic action, the relative velocity of the piston is V = 0.5 m / s, the spring stiffness is k = 3000 N / mm, and the relative deformation u is 20 mm.

[0025] Viscous damping force FC =CV ɑ =500·(0.5) 0.5 ≈354N.

[0026] Spring elastic force F k =ku=3000·0.02=60N.

[0027] Total resistance F = F C +F k =354+60=414N.

Claims

1. A viscous damper with fire-resistant function, comprising a piston rod (1), a piston head (2), a damping orifice (3), a damping medium containing phase change particles (4), a main cylinder (5), a secondary cylinder (6), and a high-temperature resistant sealing ring (7), characterized in that: The damping hole (3) is located on the piston head (2), and the piston rod (1) is connected to the piston head (2); the piston rod (1) and the piston head (2) surround the main cylinder (5) and the auxiliary cylinder (6), the main cylinder (5) is filled with damping medium (4), and the auxiliary cylinder (6) has no damping material; one end of the high-temperature resistant spring (8) is welded to the end of the piston rod (1), and the other end is welded to the inner wall of the auxiliary cylinder (6); through the movement of the piston rod (1), the damping medium (4) containing phase change particles in the main cylinder (5) passes through the damping hole (3) to generate damping force; the high-temperature resistant sealing ring (7) is installed on the end cap of the main cylinder. (9) is inside the piston rod (1) and contacts the surface of the piston rod (1). The head connector (10) is connected to the end of the piston rod (1), and the tail connector (11) is connected to the end of the auxiliary cylinder (6). One end of the telescopic fireproof cover (12) is connected to the head connector (10) by bolt (13), and the other end is connected to the end cap (9) of the main cylinder by end cap bolt (14). The pin (16) is inserted into the self-lubricating radial joint bearing (17) of the connecting seat (15) so that the viscous damper is connected to the connecting seat (15). Finally, the connecting seat (15) is connected to the wall (19) by the anchoring assembly (18).

2. The viscous damper with fireproof function according to claim 1, characterized in that: The retractable fireproof cover (12) is a galvanized sleeve with a thickness of 1.0-1.5 mm. It is fixed around the piston rod with bolts. In the event of a fire, it can protect the piston rod and prevent it from being directly affected by the fire.

3. The viscous damper with fireproof function according to claim 1, characterized in that: The retractable fireproof cover (12) is not connected to the main cylinder (5) body, but is fixed on the main cylinder end cover (9). This is beneficial for the coating of the external fireproof coating of the viscous damper. During operation, it will not affect the surface coating.

4. The viscous damper with fireproof function according to claim 1, characterized in that: The retractable fireproof cover (12) has a double-layer structure, including an outer fireproof cover (21), a middle layer of phase change material (20), and an inner fireproof cover (22).

5. The viscous damper with fireproof function according to claim 4, characterized in that: The phase change material (20) is paraffin wax, which undergoes a phase change from solid to liquid at high temperatures, absorbing a large amount of heat.

6. The viscous damper with fireproof function according to claim 1, characterized in that: The high-temperature spring (8) is made of heat-resistant spring steel with a high stiffness coefficient and can be used in environments above 300°C. The high-temperature spring (8) provides a restoring force when the piston rod (1) extends or retracts, and compensates for the thermal expansion offset of the piston rod (1) through elastic deformation in a fire environment.

7. A viscous damper with fire-resistant function according to claim 1, characterized in that: The damping medium (4) containing phase change particles contains phase change material particles. The phase change material is paraffin, and the particle size range is 10-100 μm. The phase change material particles undergo a phase change from solid to liquid at high temperature, absorbing a large amount of heat, reducing the temperature fluctuation of the damping medium (4), and maintaining its viscosity stability.

8. The viscous damper with fireproof function according to claim 1, characterized in that: The high-temperature resistant sealing ring (7) is made of polytetrafluoroethylene-coated stainless steel spring, with a temperature range of -50°C to 300°C.

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