JPH0579224A - Vibration control device - Google Patents

Abstract

PURPOSE:To cause a vibration control device to exhibit high damping effects with a small amount of liquid stored in a tank so as to minuaturize the tank by providing in the liquid of the tank actuators each of which moves and drives an attenuation means in opposite directions within the perpendicular of the tank. CONSTITUTION:Even when vibration of a structure 1 caused by small earthquakes or wind is small, a liquid 5 is forcibly vibrated by hydraulic actuators 7A, 7B and thereby vibration of the structure 1 is effectively attenuated. When the wave motion of the liquid 5 is increased more than predetermined magnitude, a vibration controller 10 stops its vibrating action performed via the actuators 7A, 7B. A tank 3 stops rotating in the directions of the arrows C, D and only the liquid 5 flows within the tank 3 via an attenuating plate 6 in the directions of the arrows A, B and the wave motion of the liquid 5 is attenuated by the attenuating plate 6 so as to prevent the wave motion from becoming excessive and obstructing the damping action. The magnitude of the wave motion of the liquid 5 can be freely adjusted by proper setting of e. g. the stroke of movement of each actuator 7A, 7B and so even when the amount of the liquid 5 in the tank 3 is small, generation of large wave motion is possible and high damping effects can be exhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device suitable for attenuating vibration generated in a structure such as a building due to an earthquake or wind.

[0002]

2. Description of the Related Art Recently, a vibration damping device consisting of a tank storing a liquid such as water having a rocking frequency matching the natural frequency of the structure has been installed on the upper part of the structure, and vibration generated in the structure has been installed. It has been proposed to absorb the wave energy of the liquid in the tank.

[0003]

However, in order to generate sufficient wave energy to absorb the vibration of the structure by such a method, the amount of liquid to be stored inside the tank is large, and the tank is inevitably inevitable. Therefore, it is inevitable that the vibration damping device becomes large. However, since this type of vibration damping device is often installed in a place with a limited space, such as a rooftop of a structure, a large size of the vibration damping device is an obstacle to installation of other equipment such as an elevator. Inconvenience occurs.

In view of the above circumstances, it is an object of the present invention to provide a vibration damping device which can exert a large vibration damping effect even with a small amount of liquid and requires a small installation space.

[0005]

That is, according to the present invention, a tank (3) is provided on an upper portion of a structure so as to be rotatable in forward and reverse directions in a vertical plane through the tank bottom portion (3j). A liquid (5) is stored in the tank so as to form an open liquid surface (5a), and a damping means (6) is provided in the liquid in the tank,
An actuator (7A, 7B) for moving and driving the tank in the normal direction in the vertical plane is provided between the tank and the structure. It should be noted that the numbers in parentheses indicate the corresponding elements in the drawings for the sake of convenience, and thus the present description is not limited to the description in the drawings.
The same applies to the section "(e). Action" below.

[0006]

With the above structure, the present invention provides the tank (3).
The liquid (5) therein acts so as to be forcibly excited together with the tank by the actuator.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of a vibration damping device according to the present invention. FIG. 2 is a front view showing another embodiment of the vibration damping device according to the present invention.

As shown in FIG. 1, a vibration damping device 2 according to the present invention is arranged on the upper surface 1a of the roof of the structure 1, and the vibration damping device 2 is a tank having a rectangular planar shape. Have three. The longitudinal direction of the tank 3 is set to the left-right direction in the figure, and the tank 3 has the bottom surface 3 of the tank 3.
It is swingably supported in the directions of arrows C and D in a vertical plane via a swing bearing 3g provided at j. The liquid 5 is stored inside the tank 3 in a form forming an open liquid surface 5a. At the center of the tank 3, a damping plate 6 made of a porous material such as a mesh is provided so as to be submerged in the liquid 5 so as to be movable in the horizontal direction in the figure, that is, in the longitudinal direction of the tank 3. Hydraulic actuators 7A and 7B are provided between the left and right side surfaces of the tank 3 in the drawing and the structure 1. Also, the structure 1
A vibration sensor 9 is provided on the upper surface 1a of the above, and the vibration control device 10 to which the above-mentioned hydraulic actuators 7A and 7B are connected is connected to the vibration sensor 9.

Since the vibration damping device 2 has the above-described structure, the structure 1 does not vibrate in a normal state.
The liquid surface 5a of the liquid 5 stored in the tank 3 is held in a horizontal state as shown in FIG. (In this state, the tank 3 is kept horizontal by the actuators 7A and 7B.) Next, if the structure 1 vibrates in the horizontal arrows A and B due to an earthquake or wind, The vibration sensor 9 detects the vibration and outputs the vibration detection signal S1 to the vibration control device 1
Output to 0. In response to this, the vibration control device 10 drives the hydraulic actuators 7A and 7B in the directions of the arrows C and D in such a manner that the rods 7a and 7a reverse their forward and backward movements in a form adapted to the vibration cycle of the structure 1. To do. Then, the tank 3 swings around the swing bearing 3g in the directions of arrows C and D, and the liquid 5 stored in the tank 3 is swung and driven as shown by the solid line in the figure. In the tank longitudinal direction,
That is, the wave starts in the directions of arrows A and B. Since the vibration mode of the liquid 5 is controlled by the vibration control device 10 so as to cancel the vibration generated in the structure 1, the vibration of the structure 1 is quickly attenuated. As soon as the structure 1 starts to vibrate, the vibration sensor 9 detects the vibration, and the vibration control device 10 forcibly vibrates the liquid 5 together with the tank 3 via the hydraulic actuators 7A and 7B. It is possible to generate a wave having a predetermined amplitude in a short time rather than waiting for the liquid 5 in the tank 3 to start a natural wave due to the vibration of the object 1, and it is possible to exhibit the vibration damping effect in a short time. Becomes

Further, even if the vibration of the structure 1 is small due to a vibration such as a small earthquake or wind, the hydraulic actuator 7A,
Since the liquid 6 is forcibly excited by 7B, the structure 1
Vibrations are effectively dampened. Further, when the wave of the liquid 5 exceeds a predetermined magnitude, the vibration control device 10 stops the vibration operation via the actuators 7A and 7B.
Then, the tank 3 stops rotating in the directions of arrows C and D, and only the liquid 5 flows through the damping plate 6 in the tank 3 in the directions of arrows A and B. The wave is damped, and the wave is prevented from becoming excessive and becoming an obstacle to the vibration damping operation. The magnitude of the wave of the liquid 5 can be arbitrarily adjusted by appropriately setting the moving stroke of the actuators 7A and 7B, so that the amount of the liquid 5 in the tank 3 is at least large. It becomes possible and can exert a high damping effect.

[0011]

As described above, according to the present invention, the tank 3 is provided on the upper part of the structure so as to be rotatable in the forward and reverse directions in the vertical plane via the bottom portion such as the tank bottom surface 3j. The liquid 5 is stored in the tank so as to form an open liquid surface 5a, and a damping means such as a damping plate 6 is provided in the liquid of the tank so that the tank is located between the tank and a structure in the vertical plane. Hydraulic actuators 7A, 7 driven to move forward and backward by
Since the actuators such as B are provided and configured, the tank 3
Since the liquid 5 inside is forcibly shaken together with the tank by the actuator, it is possible to generate a large wave even with a small amount of liquid, and the amount of liquid 5 to be stored inside can be maintained while maintaining the damping effect. It is possible to reduce the size of the tank and reduce the size of the tank, and it is possible to significantly reduce the installation area of the vibration damping device. Further, even if the vibration of the structure 1 is small, the vibration of the structure 1 can be effectively damped in a short time by forcibly exciting the liquid 5 together with the tank by the actuator, so that the wind or a small earthquake It is extremely effective in this regard.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a vibration damping device according to the present invention.

FIG. 2 is a front view showing another embodiment of the vibration damping device according to the present invention.

[Explanation of symbols]

 1 ... Structure 2 ... Damping device 3 ... Tank 5a ... Liquid level 6 ... Damping means (damping plate) 7A, 7B ... Actuator (hydraulic actuator)

Claims (1)

[Claims] 1. A tank is provided on an upper part of a structure so as to be rotatable in forward and reverse directions in a vertical plane through the tank bottom, and a liquid is stored in the tank so as to form an open liquid surface. A damping device, wherein damping means is provided in the liquid in the tank, and an actuator for moving and driving the tank in forward and backward directions in the vertical plane is provided between the tank and a structure.