A positive pressure adjustable cylindrical friction damper

Abstract

The present invention discloses a positive pressure adjustable cylindrical friction damper, which belongs to the technical field of structural shock absorption. The piston outer tube and the friction assembly generate friction force, which can quickly reduce the vibration amplitude of the structure and consume the input vibration energy. The inner tube is provided with a piston inner tube and a piston outer tube. The friction assembly is fixed in the middle of the inner tube and wraps the piston outer tube. The piston outer tube has two axial slits. After the piston inner tube with a variable cross-section shape is screwed into the piston outer tube, the piston outer tube is stretched outward, so that the positive pressure between the piston outer tube and the friction assembly is increased. When the friction damper is relatively displaced, the piston outer tube and the friction assembly rub against each other to generate a stable and reliable friction force, which better plays the role of seismic isolation and shock absorption. The present invention has a simple structure and can be used for pressure regulation. All parts and accessories can be prefabricated in the factory, which can ensure that its hysteresis curve is stable, the shock absorption protection effect is better, the safety factor is high, the structure is durable, and it can be used for a long time.

Description

Technical Field

[0001] The invention relates to the technical field of structural shock absorption, in particular to a positive pressure adjustable cylindrical friction damper. Background Art

[0002] In recent years, earthquakes have occurred frequently and have great destructive power. In addition to directly causing the collapse of houses and landslides, ground fissures, sand liquefaction, sand blasting and water seepage, they can also cause secondary disasters such as fires, explosions, the spread of toxic gases, floods, landslides, mudslides, plagues, etc. Its own destructiveness and the secondary disasters it causes seriously threaten human survival and development. With the acceleration of urban modernization and the increase and density of population, the casualties and economic losses caused by earthquakes are becoming more and more serious. How to provide new technical means for engineering structures located in earthquake zones, especially high-intensity zones, to resist strong earthquakes is an important issue that needs to be solved urgently.

[0003] At the same time, with the substantial improvement of the national economic level, the construction industry in my country has higher and higher requirements for the seismic performance of building structures. Friction dampers can effectively reduce the seismic response of structures. When an earthquake occurs, the friction characteristics lead to an increase in structural damping, and the damper consumes most of the energy to protect the main structure.

[0004] Friction damper is a damper that uses the principle of solid friction to provide the required energy dissipation. Friction refers to the sliding friction resistance and energy loss caused by the interaction of two contact surfaces. Its essence is to convert mechanical energy into heat energy and follow the law of conservation of energy. Similar to the brake device of a car, when the car brakes, the friction provided by the brake lining stops the inertia of the vehicle, so that it stops moving forward. The friction damper also uses the principle of tribology to dissipate the energy input into the structure due to vibration, slow down the movement of the building, and thus achieve the effect of energy dissipation and shock absorption. The basic formula of the friction damper is: F = μN, where F is the friction force, N is the normal pressure of the contact surface, and μ is the friction coefficient. It can be seen from the formula that the friction force is proportional to the size of the positive pressure acting on the contact surface, and its positive pressure directly affects the energy dissipation performance of the damper.

[0005] However, this method mainly relies on the friction between the steel plate surface and the friction component. The positive pressure generated by simply assembling the steel plate and the friction component in the ordinary way is small, resulting in small friction, so it is difficult to generate efficient friction. Therefore, it cannot play a good role in seismic isolation and shock reduction under large earthquakes.

[0006] Chinese utility model patent No. CN 208934172 U discloses an amplified displacement friction damper, which includes a top plate and a base, wherein a plurality of friction webs are arranged between the top plate and the base, wherein the friction webs include a first friction diagonal web bar and a second friction diagonal web bar arranged crosswise with each other. The damper forms a displacement-related damper, but the damping force generated by the damper is small and cannot be adjusted, and the energy dissipation of the damper cannot be effectively improved. Therefore, the device has great defects in structure and design, and cannot meet the needs of modern production. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a cylindrical friction damper with simple structure and adjustable positive pressure. The piston is nested by rotating the thread, forcing the piston diameter to increase, thereby increasing the positive pressure between the piston and the friction assembly. The piston and the friction assembly rub against each other to generate a stable and reliable friction force, which better plays the role of seismic isolation and shock absorption. It has high energy consumption efficiency and small energy loss, which can not only improve the effect of shock absorption and energy dissipation, but also improve the safety and durability of the structure.

[0008] The positive pressure adjustable cylinder friction damper proposed by the present invention is composed of an outer cylinder, an inner cylinder, a piston inner tube, a piston outer tube, a friction assembly, bolts, and a left connecting earring and a right connecting earring. The inner cylinder is nested inside the outer cylinder, and the inner cylinder and the outer cylinder are provided with a piston inner tube and a piston outer tube. The right side of the piston outer tube is welded and fixed to the outer cylinder, and the piston inner tube is nested in the piston outer tube by thread rotation. The friction assembly is fixed to the inner cylinder, and its inner wall is nested with the outer surface of the piston outer tube. The inner cylinder is welded and fixed to the left connecting earring, and the outer cylinder is fixed to the right connecting earring by bolts.

[0009] The main body of the outer cylinder is a steel round tube, which is welded to a round steel end plate as a whole. The end plate is fixed to the right connecting earring by bolts. The installation method is simple and convenient. The inner diameter of its cross section is 2 to 4 mm larger than the outer diameter of the inner cylinder cross section, which is convenient for the inner cylinder to be nested therein. The right end plate of the outer cylinder has a hole, and the diameter of the hole is 2 to 4 mm larger than the cross section diameter of the piston outer tube, so that the inner tube of the piston can be passed through the end plate hole. The piston outer tube is fixed to the outer cylinder by welding, and the cross section of the piston outer tube and the hole of the right end plate of the outer cylinder are concentric circles. The outer cylinder is fixed to the right connecting earring by bolts. The outer cylinder plays the role of dustproof, waterproof, guiding and protecting the internal structure.

[0010] The piston outer tube is a non-closed round tube with an internal thread inside. There are two slits in the same direction as the axis of the piston outer tube. The internal thread is a variable cross-section transitioning from a small diameter to a large diameter. The small diameter is 10mm to 20mm smaller than the large diameter. The diameter difference between the small diameter and the large diameter allows the piston outer tube to be opened by the piston inner tube. The large diameter is designed to allow the piston inner tube to be screwed in. As the depth of the piston inner tube screwing into the piston outer tube increases, the slit also increases. When the slit increases, the cross-sectional area of ​​the piston outer tube increases. The piston outer tube serves as the friction object of the friction component.

[0011] The inner tube of the piston is a steel variable-section cylinder with an external thread on the surface. The inner tube of the piston is divided into a variable-section part and a constant-section part. The variable-section part allows the inner tube of the piston to be easily screwed into the outer tube of the piston. The cross section of the variable-section part transitions from a small diameter to a large diameter, and the cross section of the constant-section part is always a large diameter. The small diameter is 5mm to 10mm smaller than the large diameter. The difference in diameter affects the size of the cross-sectional area of ​​the outer tube of the piston. The size of the large diameter is obtained by the maximum damping force design of the friction damper. The inner tube of the piston enters the outer tube of the piston from the opening of the end plate on the right side of the outer tube and is screwed in through the thread. As the screwing depth increases, the degree of expansion of the outer tube of the piston increases accordingly, providing positive pressure for the friction component. The function of the inner tube of the piston is to expand the outer tube of the piston through threaded rotation, provide adjustable positive pressure for the friction component, and increase friction.

[0012] The friction component is a non-closed circular tube with a slit in the same direction as the axis of the friction component. The inner diameter of the inner tube is Rmm, the inner diameter of the friction component is Rmm, and the outer diameter is (R+20)mm. The difference between the inner and outer diameters is twice the height of the inner tube groove. The reason for the slit is to facilitate the installation of the friction component in the groove inside the inner tube. The outer circle arc length of the slit gap is 50πmm, of which the outer circle arc length is set with a controllable margin of about 10πmm. When installing, the friction component is squeezed into the groove of the inner tube. The friction component is made of friction brake material with a high friction coefficient. When the outer tube of the piston moves, it displaces with the friction component to generate friction, thereby dissipating and absorbing the seismic energy of the structure to reduce the seismic vibration response of the structure.

[0013] The inner cylinder is nested in the outer cylinder. The main body is a steel round tube and is welded to a round steel end plate as a whole. The end plate is welded and fixed to the left connecting earring. A groove is provided on the inner cylinder. The groove is 10 mm high and has the same width as the friction assembly. The friction assembly is fixed in this groove. The groove can ensure the stability of the friction assembly when it rubs against the outer tube of the piston.

[0014] The working process 1 of the above-mentioned positive pressure adjustable cylindrical friction damper is as follows:

[0015] When the left connecting earring 6 and the right connecting earring 7 move in the same direction, the left connecting earring 6 moves to the right, driving the inner tube 2 to move to the right, thereby further driving the friction assembly 3 to move to the right. The right connecting earring 7 moves to the left, driving the outer tube 1 to move to the left, thereby further driving the piston outer tube 5 to move to the left. At this time, the friction assembly 3 and the piston outer tube 5 move in the same direction, generating friction.

[0016] The working process 2 of the above-mentioned positive pressure adjustable cylindrical friction damper is as follows:

[0017] When the left connecting earring 6 and the right connecting earring 7 generate reverse movement, the left connecting earring 6 moves to the left, driving the inner tube 2 to move to the left, thereby further driving the friction assembly 3 to move to the left. The right connecting earring 7 moves to the right, driving the outer tube 1 to move to the right, thereby further driving the piston outer tube 5 to move to the right. At this time, the friction assembly 3 and the piston outer tube 5 generate reverse movement, generating friction.

[0018] In addition, the damper has a regular structure, and all parts and accessories can be prefabricated in the factory, which is economical and reasonable. The use of this positive pressure adjustable cylindrical friction damper can ensure that its damping force is greatly increased, the shock absorption protection effect is better, the sealing is easy to handle, the safety factor is higher, the structure is durable, and it can be used for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the technical description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of a positive pressure adjustable cylindrical friction damper;

[0021] Figure 2 It is the left section schematic diagram of the friction damper;

[0022] Figure 3 It is a schematic diagram of the connection between the inner tube and the left connecting earring;

[0023] Figure 4 It is a schematic diagram of the connection between the piston outer tube and the outer cylinder;

[0024] Figure 5 It is a schematic diagram of the connection between the outer tube and the right connecting earring;

[0025] Figure 6 It is a schematic diagram of the inner cylinder groove;

[0026] Figure 7 It is a schematic diagram of the friction component;

[0027] Figure 8 It is a schematic diagram of the process of nesting the piston inner tube and the piston outer tube;

[0028] Fig. 9 Schematic diagram of the movement direction of the piston and the friction component in working process 1;

[0029] Fig.10 Schematic diagram of the movement direction of the piston and friction component in working process 2.

[0030] exist Figures 1 to 10 In the figure, 1 is an outer tube; 2 is an inner tube; 3 is a friction assembly; 4 is a piston inner tube; 5 is a piston outer tube; 6 is a left connecting earring; and 7 is a right connecting earring. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0032] Figure 1 Schematic diagram of the overall structure of the positive pressure adjustable cylindrical friction damper according to the present invention. Figure 1 As shown, the positive pressure adjustable cylinder friction damper mainly includes an outer cylinder 1, an inner cylinder 2, a friction assembly 3, a piston inner tube 4, a piston outer tube 5, a left connecting earring 6, a right connecting earring 7, a bolt 8, etc., wherein the piston inner tube 4 is threadedly embedded into the piston outer tube 5, so that the positive pressure generated by the piston outer tube 5 on the friction assembly 3 is increased. In view of the problem that the positive pressure of various friction dampers in the prior art is small and cannot be adjusted, resulting in the problem that the damping force generated by friction cannot be adjusted, the present invention provides an improved method for a traditional friction damper to achieve controllable adjustment of the positive pressure in the damper, characterized in that its construction steps are as follows:

[0033] (1) The outer cylinder 1 and the inner cylinder 2 are made of steel pipes. The inner diameter of the outer cylinder 1 is 2-4 mm larger than the outer diameter of the inner cylinder 2, so that the inner cylinder 2 can be easily nested therein. The inner diameter of the inner cylinder 2 is R mm, and a groove is provided inside the inner cylinder 2. The depth of the groove is 10 mm, and its width is the same as that of the friction component 3;

[0034] (2) The main body of the inner tube 2 is welded to a circular steel end plate, and then the end plate is welded to the left connecting earring 6. Figure 3 ;

[0035] (3) A hole is made on the right end plate of the outer cylinder 1, the diameter of which is 2 to 4 mm larger than the cross-sectional diameter of the piston outer tube 5, and the piston outer tube 5 is welded to the outer cylinder 1, and the cross-sectional area of ​​the piston outer tube 5 and the hole on the right end plate of the outer cylinder 1 are concentric circles, such as Figure 4 ;

[0036] (4) The friction material is welded into a ring with a diameter of (R+20) mm. The friction component 3 is provided with a slit with an arc length of 50πmm. The slit is pinched and squeezed into the groove of the inner tube 2 with pliers, such as Figure 6 , 7 ;

[0037] (5) The threads on the outside of the piston inner tube 4 and the inside of the piston outer tube 5 are prefabricated in the factory, and then the piston inner tube 4 is inserted into the piston outer tube 5 from the opening of the right end plate of the outer tube 1 and screwed in through the threads. As the screwing depth increases, the expansion degree of the piston outer tube 5 increases accordingly. Figure 8 ;

[0038] (6) Fix the outer tube 1 and the right connecting earring 7 with bolts 8, as shown in FIG. Figure 5 .

[0039] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A positive pressure adjustable cylindrical friction damper, characterized in that: The invention comprises an outer cylinder (1) and an inner cylinder (2), wherein the inner cylinder (2) is nested inside the outer cylinder (1), wherein a piston inner tube (4) and a piston outer tube (5) are arranged inside the outer cylinder (1) and the inner cylinder (2), wherein the right side of the piston outer tube (5) is welded and fixed to the outer cylinder (1), and the piston inner tube (4) is nested in the piston outer tube (5) by means of a threaded rotation, and the piston inner tube (4) enters the piston outer tube (5) from the opening of the right end plate of the outer cylinder (1) and is screwed in by means of a threaded rotation, and as the screwing depth increases, the piston The degree of expansion of the outer tube (5) increases accordingly, providing positive pressure for the friction component (3). The friction component (3) is fixed on the inner tube (2), and its inner wall is nested with the outer surface of the piston outer tube (5). During installation, the friction component (3) is squeezed and pressed into the groove of the inner tube (2). When the piston outer tube (5) moves, it shifts with the friction component (3) to generate friction. The inner tube (2) is fixed to the left connecting earring (6) by welding, and the outer tube (1) is fixed to the right connecting earring (7) by bolts (8).

2. A positive pressure adjustable cylindrical friction damper according to claim 1, characterized in that: The main body of the outer cylinder (1) is a steel round tube, and is welded to a round steel end plate to form a whole. The end plate is fixed to the right connecting earring (7) by bolts (8). The inner diameter of the cross section of the end plate is 2 to 4 mm larger than the outer diameter of the cross section of the inner cylinder (2), and the inner cylinder (2) is nested therein. The right end plate of the outer cylinder (1) has a hole, and the diameter of the hole is 2 to 4 mm larger than the inner diameter of the cross section of the piston outer tube (5). The piston outer tube (5) is fixed to the outer cylinder (1) by welding, and the cross section of the piston outer tube (5) and the hole of the right end plate of the outer cylinder (1) are concentric circles.

3. A positive pressure adjustable cylindrical friction damper according to claim 1, characterized in that: The piston outer tube (5) is a non-closed circular tube, the interior of the circular tube is an internal thread, and there are two slits in the same direction as the axis of the piston outer tube (5). The internal thread is a variable cross-section that transitions from a small diameter to a large diameter. The small diameter is 10 mm to 20 mm smaller than the large diameter, and the size of the large diameter is designed to allow the piston inner tube (4) to be screwed in. As the depth of the piston inner tube (4) being screwed into the piston outer tube (5) increases, the slit also increases.

4. A positive pressure adjustable cylindrical friction damper according to claim 1, characterized in that: The piston inner tube (4) is a steel variable-section cylinder with an external thread on the surface. The piston inner tube (4) is divided into a variable-section part and a constant-section part. The cross section of the variable-section part transitions from a small diameter to a large diameter, and the cross section of the constant-section part is always the large diameter. The small diameter is 5 mm to 10 mm smaller than the large diameter. The size of the large diameter is obtained by designing the maximum damping force of the friction damper.

5. The positive pressure adjustable cylindrical friction damper according to claim 1, characterized in that: The friction component (3) is a non-closed circular tube having a slit in the same direction as the axis of the friction component (3). The inner diameter of the inner tube (2) is R mm, the inner diameter of the friction component (3) is R mm, and the outer diameter is (R+20) mm. The friction component (3) is made of a friction brake material with a high friction coefficient, and the outer circle arc length of the slit notch is 50π mm.

6. The positive pressure adjustable cylindrical friction damper according to claim 1, characterized in that: The inner cylinder (2) is nested in the outer cylinder (1), and its main body is a steel round tube, which is welded to a round steel end plate to form a whole. The end plate is welded and fixed to the left connecting earring (6). A groove is provided on the inner cylinder (2). The groove is 10 mm high and has the same width as the friction component (3). The friction component (3) is fixed in the groove.

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