JPH08128230A - U shaped damping tank type vibration damping device - Google Patents

Abstract

PURPOSE: To actively adjust natural frequency of a vibration damping device in the same damping device by a U shaped damping tank. CONSTITUTION: Closed air chambers 2, 2 respectively formed on left and right upper surfaces of a U shaped damping tank 1 are connected to each other by an air communicating pipe 3, a windmill 4 to rotate by movement of air in the air communicating pipe 3 is provided, and a DC servo motor as an actuator 6 is directly connected to the windmill 4. In the meantime, a damping effect is improved by way of matching natural frequency of the whole of a vibration damping device with frequency of a structure 5 by transmitting the frequency of the structure 5 detected by a displacement gauge 7 installed on the structure 5 and forcibly adjusting movement of the air in the air communicating pipe 3 by means of controlling the actuator 6 by a control device 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a U-shaped vibration control tank type vibration control device, and more particularly to a U-shaped vibration control tank type vibration control device capable of actively adjusting the natural frequency of the vibration control device. Regarding the device.

[0002]

2. Description of the Related Art As a vibration damping device for structures such as buildings, a vibration damping device having a U-shaped vibration damping tank as shown in FIGS. 5 and 6 has been proposed. That is, as shown in FIGS. 5 and 6, the conventional damping device has a U-shaped damping tank 1
And a closed air chamber 2 formed on the left and right upper surfaces of the vibration damping tank 1, respectively, and the vibration frequency of the liquid (water W) in the U-shaped vibration damping tank 1 is attached to the vibration damping device. By synchronizing with the natural frequency of the (building), the liquid in the vibration damping device can absorb and damp the vibration of the structure.

[0003]

With the increase in the height and length of structures, there is a problem that the structure becomes flexible and slender, and is easily shaken by wind, traffic vibration, earthquakes, or the like.
In the conventional U-shaped vibration damping tank type vibration damping device, as described above, the natural frequency of the vibration damping device is tuned around the frequency of the structure, and the vibration of the vibration damping device is greatly shaken by the mass (copper weight or fluid). It absorbs energy and damps vibrations to suppress the shaking of the structure. The vibration damping device having such a principle is called a "passive vibration damping device".

On the other hand, an attempt is made to obtain a higher damping effect by actively changing the frequency of the vibration damping device in accordance with any frequency component of the vibration of the structure and synchronizing it with the vibration. A vibration control device based on such a principle is called "active vibration control device").

By the way, in such an active type vibration damping device, when the vibration damping device is large, the actuator for moving the mass becomes large, and its energy source, noise, installation space, etc. become a problem. It is an object of the present invention to provide an active U-shaped vibration damping tank type vibration damping device that solves such problems.

[0006]

In order to achieve the above-mentioned object, a U-shaped vibration damping tank type vibration damping device according to claim 1 is provided.
In a U-shaped damping tank type vibration damping device attached to a structure, a U-shaped damping tank filled with a liquid is formed in each of the upper left and right sides to form a closed air chamber. The communication pipe, adjusting means for forcibly adjusting the movement of the air inside the air communication pipe in accordance with the frequency of the structure, and the adjusting means to control the natural frequency of the vibration damping device. It is characterized in that a control device for making the frequency of the structure substantially match is provided.

According to a second aspect of the present invention, there is provided a U-shaped vibration damping tank type vibration damping device according to the first aspect, wherein the adjusting means is provided in the air communication pipe. And a natural frequency of the damping device by controlling the rotational force of the wind turbine by the control device according to the frequency of the structure. Is configured to substantially match the frequency of the structure.

Further, the U-shaped vibration damping tank type vibration damping device according to claim 3 is the U-shaped vibration damping tank type vibration damping device according to claim 1 or 2, wherein the adjusting means is provided in the air communicating pipe. It is characterized in that it is provided with a flow control valve or a sluice valve provided, and the control device can adjust the opening degree of the air communication pipe by the flow control valve or the sluice valve.

[0009]

In the above-described U-shaped vibration damping tank type vibration damping device of the present invention, when the structure is shaken by an external force above a certain level such as an earthquake, wind, or traffic vibration, liquid (water) in the U-shaped vibration damping tank Following this, the swaying is repeated, and the swaying causes the liquid in the vertical rising portion of the vibration damping tank to move up and down, whereby the air in the closed air chamber and the air communication pipe reciprocates left and right. At this time, the control device receives the vibration signal of the structure and controls the adjusting means so as to forcibly adjust the movement of the air in the air communication pipe, whereby the natural frequency of the vibration damping device is changed. The action is made to approximately match.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A U as an embodiment of the present invention will now be described with reference to the drawings.
The character-shaped vibration damping tank type vibration damping device will be described. FIG. 1 is a schematic side sectional view of the first embodiment, and FIG. 2 is a block diagram of the control device. 3 is a schematic side sectional view of the second embodiment, and FIG. 4 is a schematic side sectional view of the third embodiment. 1 to 4, the same reference numerals as those in FIGS. 5 and 6 indicate almost the same members.

As shown in FIGS. 1 and 2, the first embodiment also includes a U-shaped damping tank 1 and closed air chambers 2 formed on the upper and left upper surfaces of the damping tank 1, respectively. Both closed air chambers 2 and 2 are connected by an air communication pipe 3. Further, a wind turbine 4 that is rotated by air moving in the air communication pipe 3 is installed in the air communication pipe 3. The wind turbine 4 has a closed structure against the outside air so that the air pressure inside the vibration damping device does not fluctuate.

Reference numeral 5 denotes a structure to which a vibration damping device is attached, and a displacement gauge 7 for detecting the frequency of the structure is attached to the structure 5. Reference numeral 8 indicates a control device, and according to the frequency of the structure 5 detected by the displacement gauge 7,
A control signal for adjusting the rotational force of the wind turbine 4 is output to the actuator 6 so that the damping effect of the damping device is maximized.

The actuator 6 is composed of a DC servomotor which is directly connected to the rotating shaft of the wind turbine 4 and is installed outside the air communication pipe 3. The actuator 6 has an optimum rotation speed calculated by the controller 8. 4 can be rotated. Further, the vibrometer 9 may be attached to the structure 5 and used together with the displacement gauge 7. In FIG. 2, reference numeral 10 is a direct current amplifier, reference numeral 11 is an A / D converter, reference numeral 12 is a CPU, reference numeral 13 is a controller (mighty servo), and reference numeral 14 is an encoder. 2 are connected as shown in FIG.

In the above-mentioned structure, when the structure 5 is swayed by a certain external force such as wind, traffic vibration, and earthquake (reciprocating movement in the direction of arrow x), the water W (in the U-shaped vibration control tank 1) The mass repeats the oscillation (reciprocating movement in the direction of the arrow Y) following it. This shaking causes the water in the vertical rising portion of the damping tank 1 to move up and down, which causes the closed air chamber 2,
The air in the air communication pipe 3 moves back and forth between left and right. The movement of the air in the left and right air communication pipes 3 causes the wind turbine 4 to rotate.

Here, the vibration frequency of the structure 5 is detected at any time by the displacement meter 7 or the vibrometer 9 installed on the structure 5.
The control device 8 controls the actuator 6 to forcibly adjust the rotational force of the wind turbine so that the damping effect is maximized.
That is, the movement of the air between the left and right closed air chambers 2, 2 is forcibly adjusted, and the frequency of the vibration damping device is controlled to substantially match the frequency of the structure 5. In this way, the vibration frequency of the vibration damping device can be tuned to the structure 5 vibrating in a certain frequency range at any time, whereby a high vibration damping effect is exhibited.

As described above, in the first embodiment,
Corresponding to all frequencies of the vibrating structure 5, the frequency of the vibration damping device can be changed at any time to substantially match the frequency of the structure 5, and a high damping effect can be obtained over a wide range of vibrations. You can In this case, since the mass of the vibration damping device, that is, the water itself is not actively moved, a large actuator is not required. In the second embodiment shown in FIG. 3, in the device of the first embodiment, a flow rate adjusting valve 16 is provided in the middle of the air communication pipe 3, and
An encoder 15 is provided which receives a control signal from the controller 8 and controls the opening of the flow rate adjusting valve 16.

With the configuration described above, in the second embodiment, the pressure of the air flowing through the air communication pipe 3 can be controlled by controlling the opening degree of the flow rate adjusting valve 16, and in cooperation with the rotation speed control of the wind turbine 4. The ease of air flow in the air communication pipe 3 can be adjusted more finely, and the natural frequency of the vibration damping device can be finely adjusted. In the second embodiment, it is possible to remove the wind turbine 4 and adjust the frequency only by the flow rate adjusting valve 16, but in this case, the frequency adjustment becomes slightly rough.

Next, in a third embodiment shown in FIG. 4, a sluice valve (orifice) is used instead of the flow rate adjusting valve 16 in the second embodiment.
18 are provided. The sluice valve 18 is vertically driven by a hydraulic cylinder 17 operated by a signal from the control device 8 to adjust the opening of the air communication pipe 3 and adjust the air pressure in the air communication pipe 3. Also in this third embodiment, it is possible to obtain substantially the same operational effects as those of the above-mentioned second embodiment.

When the structure 5 (building) shakes due to an earthquake, wind, traffic vibration, etc., the water in the damping tank 1 resonates and shakes considerably, but the amount of wind that can rotate the windmill 4 In order to reliably move the air in the air communication pipe 3, the area ratio between the closed air chamber 2 and the air communication pipe 3 is set to 20: 1.
It is desirable to set to ~ 40: 1.

[0020]

As described in detail above, according to the U-shaped vibration damping tank type vibration damping device of the present invention, the following effects and advantages are obtained. (1) The vibration frequency of the vibration damping device can be made to substantially match the vibration frequency of the structure according to all frequency components of the vibrating structure, and a high vibration damping device can be expected over a wide range. (2) Unlike the method in which the mass of the vibration damping device itself is actively moved, a large actuator is not required. (3) Since a large actuator is not used, problems such as securing a drive source, noise, and securing an installation space are alleviated compared to the conventional method.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a U-shaped vibration damping tank type vibration damping device as a first embodiment of the present invention.

FIG. 2 is a block diagram of the control device.

FIG. 3 is a schematic side sectional view of a U-shaped vibration damping tank type vibration damping device as a second embodiment of the present invention.

FIG. 4 is a schematic side sectional view of a U-shaped vibration damping tank type vibration damping device as a third embodiment of the present invention.

FIG. 5 is a perspective view of a conventional U-shaped vibration damping tank type vibration damping device.

FIG. 6 is a sectional view taken along the line AA of FIG. 5;

[Explanation of symbols]

 1 U-shaped damping tank 2 Closed air chamber 3 Air communication pipe 4 Wind turbine 5 Structure 6 Actuator 7 Displacement meter 8 Control device 9 Vibrometer 10 DC amplifier 11 A / D converter 12 CPU 13 Controller (Mighty servo) 14, 15 Encoder 16 Flow control valve 17 Hydraulic cylinder 18 Gate valve (orifice)

Claims (3)

[Claims] 1. A U-shaped vibration-damping tank type vibration damping device attached to a structure, comprising a U-shaped vibration-damping tank filled with liquid so as to form a sealed air chamber in each of the left and right upper parts, and the above-mentioned sealed air An air communication pipe that communicates with the chamber, an adjusting unit that forcibly adjusts the movement of the air inside the air communication pipe in accordance with the frequency of the structure, and a vibration damping device that controls the adjusting unit. A U-shaped vibration damping tank type vibration damping device, which is provided with a control device for making the natural frequency substantially match the vibration frequency of the structure. 2. The U-shaped vibration damping tank type vibration damping device according to claim 1, wherein the adjusting means is provided in the air communication pipe and is rotated by an aerodynamic force moving inside the air communication pipe. The control device controls the rotational force of the wind turbine according to the frequency of the structure so that the natural frequency of the vibration damping device substantially matches the frequency of the structure. A U-shaped vibration control tank type vibration control device. 3. The U-shaped vibration damping tank type vibration damping device according to claim 1, wherein the adjusting means includes a flow rate control valve or a sluice valve provided in the air communication pipe, A U-shaped vibration damping tank type vibration damping device, characterized in that the flow control valve or the sluice valve can adjust the opening of the air communication pipe.