A limited friction damper

Abstract

The present invention relates to the technical field of energy dissipation and shock absorption of building structures, and discloses a limited friction damper, including a friction plate, a ball screw, an equal-width cam mechanism and a limit frame; the equal-width cam mechanism includes a driven frame and a cam arranged in the driven frame, the friction plate is arranged on both sides of the driven frame and is tightly attached to the driven frame, the limit frame is buckled on the periphery of the driven frame to limit the movement of the driven frame in the vertical direction and the linear movement of the friction plate in the horizontal direction, the ball screw passes through the cam, and the ball nut on the ball screw is connected to the cam. Its beneficial effect is that the device can slide during a small earthquake, solving the problem that the traditional friction damper does not work during a small earthquake, and the friction stroke is always within the eccentricity of the cam, and the device will not fail due to excessive stroke, solving the problem that the traditional friction damper is prone to failure due to excessive displacement under a large earthquake.

Description

Technical Field

[0001] The invention relates to the technical field of energy dissipation and shock absorption of building structures, and in particular to a position-limiting friction damper. Background Art

[0002] In order to reduce the damage caused by earthquakes to building structures, seismic isolation technology is being used more and more widely. There are many types of dampers based on passive seismic isolation technology, which are widely used in energy dissipation and shock absorption structures. However, most existing dampers are difficult to fully play their role under small earthquakes and have poor energy dissipation capacity. Under the action of an unexpected large earthquake, the damper displacement is likely to exceed the limit displacement and fail. If a damper with a larger stroke is used, the cost is too high, which is not conducive to promotion and application.

[0003] Therefore, it is very necessary to develop a damper that can work under small earthquakes and does not fail under large earthquakes. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above prior art and to provide a limited friction damper which has a reasonable structure, can dissipate energy by friction under small earthquakes, and does not fail in displacement under large earthquakes.

[0005] The objective of the present invention is achieved through the following technical solutions: a limit friction damper, comprising a friction plate, a ball screw, an equal-width cam mechanism and a limit frame; the equal-width cam mechanism comprises a driven frame and a cam arranged in the driven frame, the friction plate is arranged on both sides of the driven frame and is tightly attached to the driven frame, the limit frame is buckled on the periphery of the driven frame to limit the movement of the driven frame in the vertical direction and the movement of the friction plate in the horizontal direction, the ball screw passes through the cam, and the ball nut on the ball screw is connected to the cam.

[0006] Furthermore, the friction plates are arranged on both sides of the upper end of the driven frame and / or on both sides of the lower end of the driven frame.

[0007] Furthermore, the driven frame is surrounded by an upper frame, a lower frame and two side frames, the cam is arranged in the driven frame, and the outer periphery of the cam abuts against the two side frames, the upper frame and the lower frame are provided with strip slide grooves running through both sides along their length directions, and friction plates are provided on both sides of the strip slide groove of the upper frame and the strip slide groove of the lower frame, and pre-tightening bolts are passed through the friction plate and the strip slide groove to make the friction plate close to the driven frame.

[0008] Furthermore, the lengths of both ends of the friction plate extending out of the driven frame are greater than the eccentricity of the cam.

[0009] Furthermore, the limit frame includes a driven frame baffle and a friction plate baffle, the driven frame baffle is fixedly connected between the two friction plate baffles and covers the top ends of the two friction plate baffles, the inner side of the driven frame baffle abuts against the upper end surface of the driven frame, and the two friction plate baffles respectively abut against the two ends of the friction plate.

[0010] Furthermore, the limit frame also includes a front baffle and a rear baffle, the front baffle is installed on the front side of the driven frame baffle and connected to the two friction plate baffles, the rear baffle is installed on the rear side of the driven frame baffle and connected to the two friction plate baffles, and the ball screw passes through the front baffle, cam and rear baffle in sequence.

[0011] Furthermore, the limiting frame also includes stiffening ribs, and the stiffening ribs are respectively connected to the front baffle and the rear baffle to support the front baffle and the rear baffle.

[0012] Furthermore, one end of the ball screw is provided with a latch assembly for connecting with a building structure or a bridge structure.

[0013] Furthermore, it also includes a base, the equal-width cam mechanism is arranged on the base, and the base cooperates with the limit frame to limit the movement of the driven frame in the vertical direction and limit the movement of the friction plate in the horizontal direction.

[0014] Furthermore, the base is provided with a plurality of mounting holes.

[0015] The present invention has the following advantages over the prior art:

[0016] 1. The present invention has a good force amplification effect by setting an equal-width cam mechanism, a limit frame, a friction plate and a ball screw. By reasonably designing the size parameters of the cam mechanism such as the pitch of the ball screw, the radius of the cam, the size of the eccentricity, etc., the force amplification multiple can be adjusted to several times or even dozens of times, so that a large friction force can be provided by a small preload. Reasonable adjustment of the preload can solve the problem that the traditional friction damper cannot slide in a small earthquake; and because of the amplification effect brought by the rotation effect, the device applies a small preload, which has the effect of a large-tonnage friction damper after amplification, and has obvious economic effects.

[0017] 2. The outstanding feature of the present invention is that it can perform multiple cycles of reciprocating friction, and the friction stroke is always within the eccentric distance of the cam, which effectively avoids the phenomenon that the traditional friction damper fails due to excessive stroke when the structure encounters rare or even extremely rare earthquakes.

[0018] 3. The present invention has a good mass amplification effect. Under the action of earthquake force, the ball nut and the cam produce a great acceleration rotation and dissipate a certain amount of energy. Moreover, the greater the acceleration, the more mass energy dissipated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 It shows a schematic structural diagram of a limit friction damper according to the present invention;

[0021] Figure 2 It shows a schematic structural diagram of the connection between the equal-width cam mechanism and the ball screw according to the present invention;

[0022] Figure 3 A schematic structural diagram showing the connection between the equal-width cam mechanism and the friction plate according to the present invention is shown.

[0023] In the figure, 1 is a friction plate; 2 is a ball screw; 3 is a limit frame; 4 is a driven frame; 5 is a cam; 6 is an upper frame; 7 is a lower frame; 8 is a side frame; 9 is a strip slide; 10 is a driven frame baffle; 11 is a friction plate baffle; 12 is a front baffle; 13 is a stiffening rib; 14 is a latch assembly; 15 is a base; 16 is a ball nut; 17 is a common bolt; 18 is a rear baffle; and 19 is a pre-tightening bolt. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1 and Figure 2 The limit friction damper shown comprises a friction plate 1, a ball screw 2, an equal-width cam mechanism and a limit frame 3; the equal-width cam mechanism comprises a driven frame 4 and a cam 5 arranged in the driven frame 4, the friction plate 1 is arranged on both sides of the driven frame 4 and is tightly attached to the driven frame 4, the installation direction of the friction plate 1 is perpendicular to the ball screw 2, the limit frame 3 is buckled on the periphery of the driven frame 4 to limit the movement of the driven frame 4 in the vertical direction and the movement of the friction plate 1 in the horizontal direction, the ball screw 2 passes through the cam 5, and the ball nut 16 on the ball screw 2 is connected to the cam 5. When the building structure or bridge structure is displaced and drives the ball screw 2 to move, the ball screw 2 drives the ball nut 16 to rotate and then drives the cam 5 to rotate. Due to the restraining effect of the limit frame 3, the driven frame 4 only performs horizontal reciprocating motion within the stroke of the eccentric distance of the cam 5. At the same time, the driven frame 4 and the friction plate 1 generate friction, and the friction energy consumption is used to achieve the effect of shock absorption. The moving direction of the driven frame 4 is perpendicular to the ball screw 2. By adjusting the closeness of the friction plate 1 and the driven frame 4, the magnitude of the friction between the two is controlled, so that the damper can dissipate energy by friction under small earthquakes. The left and right moving distance of the driven frame is limited by the eccentricity of the cam 5, so that the damper does not fail to move under large earthquakes.

[0026] The friction plate 1 is arranged on both sides of the upper end of the driven frame 4 and / or on both sides of the lower end of the driven frame 4. In specific implementation, the friction plate 1 can be installed on both sides of the upper end of the driven frame 4, or on both sides of the lower end of the driven frame 4. In order to improve the shock absorption effect of the device, it is preferred that the friction plate 1 is installed on both sides of the upper end and the lower end of the driven frame 4.

[0027] like Figure 3 As shown, the driven frame 4 is surrounded by an upper frame 6, a lower frame 7 and two side frames 8, the cam 5 is arranged in the driven frame 4, and the periphery of the cam 5 abuts against the two side frames 8, the upper frame 6 and the lower frame 7 are both provided with strip chute 9 running through both sides thereof along their length direction, and both sides of the strip chute 9 of the upper frame 6 and the strip chute 9 of the lower frame 7 are provided with friction plates 1, and the friction plates 1 on both sides are connected with the strip chute 9 by pre-tightening bolts 19, so that the friction plates 1 are closely attached to the upper frame 6 and the lower frame 7 of the driven frame. The upper frame 6 and the lower frame 7 are connected with the friction plates 1 by pre-tightening bolts 19, and the pre-tightening bolts 19 can generate pre-tightening force, and the magnitude of the pre-tightening force can be adjusted by the pre-tightening bolts 19, thereby adjusting the degree of closeness between the friction plates 1 and the driven frame 4, and controlling the magnitude of the friction force on the driven frame 4, which can solve the problem that the transmission friction damper cannot slide in a small earthquake. By providing the strip chute 9, the movement of the driven frame 4 will not be affected by the pre-tightening bolts 19. The driven frame 4 is rectangular. In order to improve the stability of the limit friction damper, the top of the friction plate 1 located on both sides of the upper frame 6 is flush with the top of the upper frame 6, and the bottom of the friction plate 1 located on both sides of the lower frame 7 is flush with the bottom of the lower frame 7, and the friction plates located on both sides of the lower frame 7 are also fixedly connected to the base. The driven frame 4 reciprocates under the drive of the cam 5 and rubs against the friction plate 1, using friction energy consumption to achieve the effect of shock absorption.

[0028] The length of the two ends of the friction plate 1 extending out of the driven frame 4 is greater than the eccentricity of the cam 5. The driven frame 4 follows the cam 5 to make reciprocating motion, and the maximum stroke of the driven frame 4 to one side is the eccentricity of the cam. Through this arrangement, the driven frame 4 can maintain friction with the friction plate 1 during the reciprocating motion, which can effectively improve the shock absorption effect.

[0029] The limit frame 3 includes a driven frame baffle 10 and a friction plate baffle 11. The driven frame baffle 10 is fixedly connected between the two friction plate baffles 11 and covers the top ends of the two friction plate baffles 11. The inner side of the driven frame baffle 10 abuts against the upper end surface of the driven frame 4. The two friction plate baffles 11 abut against the two ends of the friction plate 1 respectively. It also includes a base 15. The bottom ends of the two friction plate baffles 11 are fixed on the base 15, and the bottom end of the driven frame 4 is placed on the base 15. By setting the driven frame baffle 10 to limit the movement of the driven frame in the vertical direction, the two ends of the friction plate 1 need to be limited by the friction plate baffle 11 to limit its displacement and limit its movement with the driven frame 4, so that the friction plate 1 is in a stationary state during the movement of the driven frame 4, so that the moving driven frame 4 and the friction plate 1 generate friction, achieving the effect of friction energy consumption.

[0030] The limit frame 3 also includes a front baffle 12 and a rear baffle 18. The front baffle 12 is installed on the front side of the driven frame baffle 10 and connected to the two friction plate baffles 11. The rear baffle 18 is installed on the rear side of the driven frame baffle 10 and connected to the two friction plate baffles 11. The ball screw 2 passes through the front baffle 12, the cam 5 and the rear baffle 18 in sequence. Among them, the front baffle 12, the cam 5 and the rear baffle 18 are all provided with through holes that match the ball screw 2. When the ball screw moves, it will not affect the front baffle 12 and the rear baffle 18. The front baffle 12, the rear baffle 18 are connected to the driven frame baffle 10 and the friction plate baffle 11 by ordinary bolts 17. The limit frame 3 cooperates with the base 15 to form a closed space set on the periphery of the equal-width cam mechanism, which can prevent external interference such as dust and moisture from affecting the durability and shock absorption effect of the limit friction damper.

[0031] The limiting frame also includes stiffening ribs, which are respectively connected to the front baffle plate and the rear baffle plate to support the front baffle plate and the rear baffle plate.

[0032] One end of the ball screw 2 is provided with a latch assembly 14 for connecting with a building structure or a bridge structure. In actual use, the latch assembly is connected to the building structure or the bridge structure through a universal joint to ensure that when an earthquake occurs, the ball screw only reciprocates in one direction without shaking. When the building structure or the bridge structure is displaced by an earthquake, the latch assembly 14 can drive the ball screw 2 to move together, and the movement of the ball screw 2 can drive the ball nut 16 to rotate, and then drive the cam 5 to rotate, so that the driven frame 4 performs horizontal reciprocating motion perpendicular to the movement direction of the ball screw 2, and its maximum stroke is the eccentricity of the cam 5.

[0033] The base 15 has a plurality of mounting holes, which are reserved for connection with beams or walls of building structures and piers of bridge structures, so that the limit friction damper and the building structure or bridge structure remain relatively still, while the ball screw 2 moves relatively.

[0034] The working principle of the limited friction damper is as follows: when an earthquake occurs, the building or bridge structure drives the ball screw 2 to move together through the bolt assembly 14, and the ball screw 2 moves horizontally while the ball nut 16 rotates, thereby driving the cam 5 to rotate. Due to the eccentric rotation of the cam 5 and the vertical constraint of the limit frame 3 on the driven frame 4, the driven frame 4 will perform horizontal reciprocating motion perpendicular to the direction of the ball screw 2, and the motion stroke is always within the eccentric distance of the cam 5. Because the driven frame 4 and the friction plate 1 are connected together by the pre-tightening bolts 19, the friction plate 1 is constrained by the friction plate baffle 11, so the driven frame 4 generates friction with the friction plate while moving, achieving the purpose of energy consumption. And because the strip slide 9 reserved in the driven frame 4 allows the pre-tightening bolts 19 to connect the driven frame 4 and the friction plate 1 without hindering their movement. Finally, the front baffle 12 and the rear baffle 18 are added, and the baffles are connected into a whole with ordinary bolts 17 to form a closed space, which can prevent external interference such as dust and moisture from affecting the durability and shock absorption effect of the device.

[0035] The present limited friction damper has a good friction force amplification effect due to the rotation effect. By reasonably setting the size parameters of the device, such as the size of the ball screw pitch, the cam radius, the size of the eccentricity, etc., the force can be amplified several times or even dozens of times. By applying a very small preload force, the shock-absorbing effect of a large-tonnage damper can be produced, saving the cost; and the size of the preload force can be further adjusted so that the present limited friction damper can slide during a small earthquake, thereby solving the problem that the traditional friction damper does not work during a small earthquake; due to the working mechanism of the equal-width cam mechanism, the movement stroke of the driven frame is always within the eccentricity of the cam. Due to this limiting effect, the present limited friction damper will never fail due to excessive stroke, thereby solving the problem that the traditional friction damper is prone to fail due to excessive displacement during a large earthquake.

[0036] The above specific implementation modes are preferred embodiments of the present invention and cannot be used to limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. A limited friction damper, characterized in that: It comprises a friction plate, a ball screw, an equal-width cam mechanism and a limit frame; the equal-width cam mechanism comprises a driven frame and a cam arranged in the driven frame, the friction plate is arranged on both sides of the driven frame and is tightly attached to the driven frame, the limit frame is buckled on the periphery of the driven frame to limit the movement of the driven frame in the vertical direction and the movement of the friction plate in the horizontal direction, the ball screw passes through the cam, and the ball nut on the ball screw is connected to the cam; The friction plates are arranged on both sides of the upper end of the driven frame and / or on both sides of the lower end of the driven frame; The driven frame is surrounded by an upper frame, a lower frame and two side frames, the cam is arranged in the driven frame, and the periphery of the cam abuts against the two side frames, the upper frame and the lower frame are provided with strip-shaped slide grooves running through both sides thereof along their length direction, friction plates are arranged on both sides of the strip-shaped slide groove of the upper frame and the strip-shaped slide groove of the lower frame, and the pre-tightening bolts pass through the friction plates and the strip-shaped slide grooves to make the friction plates close to the driven frame; The limit frame includes a driven frame baffle and a friction plate baffle, the driven frame baffle is fixedly connected between the two friction plate baffles and covers the top ends of the two friction plate baffles, the inner side of the driven frame baffle abuts against the upper end surface of the driven frame, and the two friction plate baffles abut against the two ends of the friction plate respectively; The limit frame also includes a front baffle and a rear baffle, the front baffle is installed on the front side of the driven frame baffle and connected to the two friction plate baffles, the rear baffle is installed on the rear side of the driven frame baffle and connected to the two friction plate baffles, and the ball screw passes through the front baffle, the cam and the rear baffle in sequence.

2. The limited friction damper according to claim 1, characterized in that: The limiting frame also includes stiffening ribs, which are respectively connected to the front baffle plate and the rear baffle plate to support the front baffle plate and the rear baffle plate.

3. The limited friction damper according to claim 1, characterized in that: The lengths of the two ends of the friction plate extending out of the driven frame are greater than the eccentricity of the cam.

4. The limited friction damper according to claim 1, characterized in that: One end of the ball screw is provided with a latch assembly for connecting with a building structure or a bridge structure.

5. The limited friction damper according to claim 1, characterized in that: It also includes a base, the equal-width cam mechanism is arranged on the base, and the base cooperates with the limit frame to limit the movement of the driven frame in the vertical direction and the movement of the friction plate in the horizontal direction.

6. The limited friction damper according to claim 5, characterized in that: The base is provided with a plurality of mounting holes.

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