Viscous damper with variable damping force

Abstract

The utility model provides a variable damping force viscous damper which comprises a cylinder barrel, bushings connected to the two ends of the cylinder barrel, a piston movably arranged in the cylinder barrel, a piston rod penetrating through the center of the piston, with the two ends penetrating through center holes of the bushings and extending outwards, and damping fluid filled in a closed cavity defined by the cylinder barrel, the bushings, the piston and the piston rod. An annular outer gap is formed between the outer wall of the piston and the inner wall of the cylinder barrel, the variable-diameter guide rod is arranged in an open hole of the piston in a penetrating mode, and the two ends of the variable-diameter guide rod are fixedly arranged on the lining in an inserted mode. The inner diameter of the open hole is larger than the outer diameter of the first rod body and the outer diameter of the second rod body, and when the piston moves to the first rod body and the second rod body, a first annular inner gap and a second annular inner gap which are different in width can be formed between the inner wall of the open hole and the outer wall of the variable-diameter guide rod, so that the overflowing area of a damping liquid flowing channel is changed, and the variable damping force effect is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of viscous dampers, and particularly relates to a variable damping force viscous damper. Background Technique

[0002] A viscous damper is a velocity-related damper in which a piston moves relative to a cylinder barrel. Due to its excellent energy dissipation and shock absorption effects, it is widely used in structural engineering fields such as bridges, equipment, and buildings. When the piston of the viscous damper reciprocates in the cylinder barrel, the viscous damping fluid quickly flows through the gap between the piston and the cylinder barrel or the holes on the piston, generating a damping force, thereby realizing the energy dissipation function of the viscous damper.

[0003] The bridge vehicle-induced vibration generated by vehicles, the vibration of industrial equipment, and the continuous vibration of wind loads have the characteristics of small displacement, high frequency, and long duration. When using a viscous damping device to control vibration, on the one hand, it is necessary for the viscous damper to generate a small damping force in order to achieve the purpose of energy exchange balance between the viscous damper and the external environment, and prevent the risk of the failure of the damping device due to excessive energy accumulation in the closed space of the viscous damper; on the other hand, when encountering large earthquakes and large displacements, it is necessary for the viscous damper to generate a large damping force to consume energy and ensure that the building structure is not damaged.

[0004] In response to this problem, double-stage or multi-stage viscous damper design schemes have emerged on the market. For example, Chinese Patent CN113187842A discloses a multi-stage viscous damper, which uses one or more limiting members to achieve the function of double-stage or multi-stage energy dissipation. Its disadvantages are as follows: ① It is necessary to assemble one or more sliding pistons and fasteners. The multiple pistons connected in series simultaneously make the overall length of the viscous damper longer, occupying too much product installation space and increasing the manufacturing cost of the product; ② Through experimental verification, the hysteresis curve of this type of multi-stage viscous damper is a stepped hysteresis curve symmetric about the origin, which is contrary to the requirement of the axisymmetric hysteresis curve needed by the structural system. Another example is the multi-stage viscous dampers disclosed in Chinese Patents CN116792440A, CN218494085U, and CN114110071A. This type of multi-stage viscous damper mainly changes the gap between the piston and the cylinder barrel by segmentally changing the inner diameter size of the cylinder barrel, so as to achieve the function of double-stage or multi-stage energy dissipation. Its disadvantages are as follows: As the most critical component of the viscous damper, the cylinder barrel has high processing accuracy and requirements. The cost of processing cylinder barrels with various different variable diameter differences is high, and mass production is relatively difficult. Content of the Utility Model

[0005] The purpose of the utility model is to overcome one or more disadvantages in the prior art and provide a variable damping force viscous damper.

[0006] To achieve the above object, the technical solution adopted by the present utility model is a variable damping viscous damper, comprising:

[0007] A cylinder barrel;

[0008] Bushings, the bushings are connected to both ends of the cylinder barrel and seal the openings at both ends of the cylinder barrel;

[0009] A piston, the piston is movably arranged in the cylinder barrel, and an annular outer gap is formed between the outer wall of the piston and the inner wall of the cylinder barrel;

[0010] A piston rod, the middle part of the piston rod passes through the center of the piston and is connected to the piston as a whole, and both ends of the piston rod pass through the central holes of the bushings and extend outwards;

[0011] Damping fluid, the damping fluid is filled in the closed cavity formed by the cylinder barrel, the bushings, the piston and the piston rod;

[0012] The variable damping viscous damper further includes a variable diameter guide rod arranged in the cylinder barrel. The variable diameter guide rod passes through the opening of the piston, and both ends of the variable diameter guide rod are inserted and fixed on the bushings. The variable diameter guide rod has a first rod body with a smaller outer diameter and a second rod body with a larger outer diameter. The inner diameter of the opening is larger than the outer diameters of the first rod body and the second rod body. When the piston moves to the positions of the first rod body and the second rod body, a first inner gap and a second inner gap which are annular and have different widths are formed between the inner wall of the opening and the outer wall of the variable diameter guide rod.

[0013] Preferably, the length of the first rod body is one-fourth to one-half of the length of the variable diameter guide rod.

[0014] Preferably, the second rod body is connected to both ends of the first rod body, and the free ends of the second rod body are inserted and fixed on the bushings.

[0015] Preferably, there are multiple variable diameter guide rods, and the multiple variable diameter guide rods are evenly distributed around the axis line of the piston rod.

[0016] Preferably, a static seal and a first dust-proof ring are provided between the outer wall of the bushing and the inner wall of the cylinder barrel, and a dynamic seal and a second dust-proof ring are provided between the outer wall of the piston rod and the inner wall of the central hole.

[0017] Preferably, the variable damping viscous damper further includes a pin head and a connecting ear plate. The pin head is connected to one end of the piston rod, and the connecting ear plate is connected to the end of the cylinder barrel corresponding to the other end of the piston rod.

[0018] Further preferably, spherical plain bearings are provided on both the pin head and the connecting ear plate.

[0019] Further preferably, the bushing near the connecting ear plate is axially inwardly retracted along the cylinder barrel to form a blind hole at the end of the cylinder barrel. The variable-damping viscous damper further includes a connecting pipe. One end of the connecting pipe is connected to the connecting ear plate, and the other end is inserted into the blind hole and abuts against the bushing.

[0020] Further preferably, the length of the connecting pipe is not less than the distance between the two bushings at both ends of the cylinder barrel.

[0021] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0022] The variable-damping viscous damper provided by the present invention includes a cylinder barrel, bushings connected to both ends of the cylinder barrel, a piston movably arranged in the cylinder barrel, a piston rod passing through the center of the piston and having both ends passing through the center holes of the bushings and extending outwards, a damping liquid filled in the closed cavity surrounded by the cylinder barrel, bushings, piston, and piston rod, and a variable-diameter guide rod arranged in the cylinder barrel. An annular outer gap is formed between the outer wall of the piston and the inner wall of the cylinder barrel. The variable-diameter guide rod passes through the opening of the piston, and both ends are inserted and fixed on the bushings. By making the variable-diameter guide rod have a first rod body with a smaller outer diameter and a second rod body with a larger outer diameter, and making the inner diameter of the opening larger than the outer diameters of the first rod body and the second rod body, when the piston moves to the positions of the first rod body and the second rod body, a first inner gap and a second inner gap that are annular and have different widths can be formed between the inner wall of the opening and the outer wall of the variable-diameter guide rod, thereby changing the flow area of the damping liquid flow channel composed of the outer gap, the first inner gap, and the second inner gap, and achieving the effect of variable damping force. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic cross-sectional view of a preferred embodiment of the present invention. At this time, the piston moves to the position of the first rod body.

[0024] Figure 2 is Figure 1 a schematic diagram of the piston moving to the position of the second rod body in

[0025] Figure 3 is Figure 1 a partial enlarged schematic view of part A in

[0026] Figure 4 is Figure 2 a partial enlarged schematic view of part B in

[0027] Figure 5 is a damping force-displacement hysteresis curve diagram of a preferred embodiment of the present invention.

[0028] Wherein: 1. connecting ear plate; 2. spherical plain bearing; 3. connecting pipe; 4. bushing; 5. piston rod; 6. cylinder barrel; 7. static seal; 8. first dust ring; 9. pin head; 10. second dust ring; 11. dynamic seal; 12. damping fluid; 13. piston; 14. variable-diameter guide rod; 15. first rod body; 16. second rod body; 17. outer gap; 18. first inner gap; 19. second inner gap. Detailed implementation mode

[0029] The following further describes the present utility model in conjunction with the embodiments shown in the drawings.

[0030] As Figures 1 to 4 shown, the variable-damping force viscous damper provided by the present utility model includes: cylinder barrel 6, bushing 4, piston 13, piston rod 5, damping fluid 12, variable-diameter guide rod 14. Among them, the bushing 4 is connected to both ends of the cylinder barrel 6 and seals the openings at both ends of the cylinder barrel 6; the piston 13 is movably arranged in the cylinder barrel 6, and an annular outer gap 17 is formed between the outer wall of the piston 13 and the inner wall of the cylinder barrel 6; the middle part of the piston rod 5 penetrates through the center of the piston 13 and is connected with the piston 13 as a whole, and both ends of the piston rod 5 penetrate through the central holes of the bushing 4 and extend outwards; the damping fluid 12 is filled in the closed cavity surrounded by the cylinder barrel 6, the bushing 4, the piston 13, and the piston rod 5; the variable-diameter guide rod 14 is arranged in the cylinder barrel 6, the variable-diameter guide rod 14 passes through the opening in the piston 13, and both ends of the variable-diameter guide rod 14 are inserted and fixed on the bushing 4. The variable-diameter guide rod 14 has a first rod body 15 with a smaller outer diameter and a second rod body 16 with a larger outer diameter. The inner diameter of the opening in the piston 13 is greater than the outer diameters of the first rod body 15 and the second rod body 16. When the piston 13 moves to the positions of the first rod body 15 and the second rod body 16, a first inner gap 18 and a second inner gap 19 which are annular and have different widths are formed between the inner wall of the opening in the piston 13 and the outer wall of the variable-diameter guide rod 14, so as to change the flow area of the damping fluid flow channel composed of the outer gap 17, the first inner gap 18, and the second inner gap 19, and achieve the effect of variable damping force.

[0031] Preferably, the length of the first rod body 15 is one-fourth to one-half of the length of the variable-diameter guide rod 14, and there are multiple variable-diameter guide rods 14, and the multiple variable-diameter guide rods 14 are evenly distributed around the axis line of the piston rod 5.

[0032] In this embodiment, the second rod body 16 is connected to both ends of the first rod body 15, and the free ends of the second rod body 16 are inserted and fixed on the bushing 4.

[0033] In this embodiment, a static seal 7 and a first dust ring 8 are provided between the outer wall of the bushing 4 and the inner wall of the cylinder barrel 6, and a dynamic seal 11 and a second dust ring 10 are provided between the outer wall of the piston rod 5 and the inner wall of the central hole of the bushing 4.

[0034] In this embodiment, the variable-damping viscous damper further includes a pin head 9 and a connecting ear plate 1. One end of the pin head 9 is connected to one end of the piston rod 5, and the connecting ear plate 1 is connected to the end of the cylinder barrel 6 corresponding to the other end of the piston rod 5. Specifically, the pin head 9 and the piston rod 13 are connected by a threaded type. When an inter-story displacement of the building structure occurs due to an earthquake or vibration, the piston rod 5 can drive the piston 13 to move back and forth along the axis direction of the cylinder barrel 6. Further, spherical plain bearings 2 are provided on both the pin head 9 and the connecting ear plate 1, and the connecting ear plate 1 and the pin head 9 are respectively pivotally connected to the upper and lower layers of the building structure through the spherical plain bearings 2 and a pin.

[0035] In this embodiment, the bushing 4 near the connecting ear plate 1 is shrunk inward along the axial direction of the cylinder barrel 6 to form a blind hole at the end of the cylinder barrel 6. The variable-damping viscous damper further includes a connecting pipe 3. One end of the connecting pipe 3 is connected to the connecting ear plate 1, and the other end is inserted into the blind hole and abuts against the bushing 4. Further, the length of the connecting pipe 3 is not less than the difference between the distance between the two bushings 4 at both ends of the cylinder barrel 6 and the width of the piston 13.

[0036] In this embodiment, both ends of the variable-diameter guide rod 14 (the free ends of the second rod body 16) are directly inserted into the reserved holes on the bushing 4 and fixedly installed.

[0037] The adjustment of the damping force magnitude of the variable-damping viscous damper can be achieved by adjusting the widths of the outer gap 17, the first inner gap 18, and the second inner gap 19. The displacement corresponding to the damping force of the variable-damping viscous damper can be satisfied by adjusting the position of the first rod body 15 on the variable-diameter guide rod 14 to meet the design requirements. The number of variable-diameter guide rods 14 in the variable-damping viscous damper can be determined according to the design requirements and the installation space size of the variable-damping viscous damper.

[0038] The damping force-displacement hysteresis curve of the variable-damping viscous damper is as Figure 5 shown, and the coordinate points -U y1 ~0 and 0~U y1 reach the displacement of the first stage of the variable-damping viscous damper, and the corresponding damping force at the same loading frequency is F y1 (the positive or negative sign is related to the velocity direction); when the displacement exceeds U y1 , as Figure 5 shown, the coordinate points -U y2 ~-U y1 and U y1 ~U y2 reach the displacement of the second stage of the variable-damping viscous damper, and the corresponding damping force at the same loading frequency is F y2 (the positive or negative sign is related to the velocity direction).

[0039] The damping force-displacement hysteresis curve of the variable-damping viscous damper is distributed in a dumbbell shape symmetrical about the x and y axes, which can meet the service requirements of the structural system.

[0040] The above embodiments are only used to illustrate the technical concept and characteristics of the present utility model. The purpose is to enable those skilled in the art to understand the content of the present utility model and implement it accordingly, and it should not be used to limit the protection scope of the present utility model. Any equivalent changes or modifications made according to the spirit of the present utility model should be covered within the protection scope of the present utility model.

Claims

1. A variable damping force viscous damper, comprising: A cylinder barrel; A bushing, which is connected to both ends of the cylinder barrel and seals the openings at both ends of the cylinder barrel; A piston, which is movably arranged in the cylinder barrel, and an annular outer gap is formed between the outer wall of the piston and the inner wall of the cylinder barrel; A piston rod, the middle part of which passes through the center of the piston and is connected to the piston as a whole, and both ends of the piston rod pass through the central holes of the bushings and extend outwards; A damping liquid, which is filled in the enclosed cavity formed by the cylinder barrel, the bushing, the piston and the piston rod; Characterized in that: The variable damping force viscous damper further includes a variable diameter guide rod arranged in the cylinder barrel. The variable diameter guide rod passes through the opening of the piston, and both ends of the variable diameter guide rod are inserted and fixed on the bushing. The variable diameter guide rod has a first rod body with a smaller outer diameter and a second rod body with a larger outer diameter. The inner diameter of the opening is larger than the outer diameters of the first rod body and the second rod body. When the piston moves to the positions of the first rod body and the second rod body, a first inner gap and a second inner gap which are annular and have different widths are formed between the inner wall of the opening and the outer wall of the variable diameter guide rod.

2. The variable-damping viscous damper according to claim 1, wherein: The length of the first rod body is one-fourth to one-half of the length of the variable diameter guide rod.

3. The variable-damping viscous damper according to claim 1, wherein: The second rod body is connected to both ends of the first rod body, and the free ends of the second rod body are inserted and fixed on the bushing.

4. The variable-damping viscous damper according to claim 1, characterized in that: There are multiple variable diameter guide rods, and the multiple variable diameter guide rods are evenly distributed around the axis of the piston rod.

5. The variable damping force viscous damper according to claim 1, characterized in that: A static seal and a first dust-proof ring are arranged between the outer wall of the bushing and the inner wall of the cylinder barrel, and a dynamic seal and a second dust-proof ring are arranged between the outer wall of the piston rod and the inner wall of the central hole.

6. The variable-damping viscous damper according to claim 1, characterized in that: The variable damping force viscous damper further includes a pin head and a connecting ear plate. The pin head is connected to one end of the piston rod, and the connecting ear plate is connected to the end of the cylinder barrel corresponding to the other end of the piston rod.

7. The variable damping force viscous damper according to claim 6, wherein: Joint bearings are arranged on both the pin head and the connecting ear plate.

8. The variable damping force viscous damper according to claim 6, characterized in that: The bushing near the connecting ear plate shrinks inwards along the axial direction of the cylinder barrel to form a blind hole at the end of the cylinder barrel. The variable damping force viscous damper further includes a connecting pipe. One end of the connecting pipe is connected to the connecting ear plate, and the other end is inserted into the blind hole and abuts against the bushing.

9. The variable-damping viscous damper according to claim 8, wherein: The length of the connecting pipe is not less than the distance between the two bushings at both ends of the cylinder barrel.

Images