JPH0434187A - Damping device using fluid - Google Patents

Abstract

PURPOSE:To restrain a vibration by providing a porous intermediate plate in a vessel at the intermediate position thereof in a height direction, and filling the vessel with liquid in such a way as to form a liquid level on the intermediate plate for enabling the sloshing liquid to move vertically. CONSTITUTION:An intermediate plate 11 comprising a porous body is laid horizontally within a box type vessel 10, and this vessel 10 is filled with liquid 12 like water in such a way as to form a liquid level WL on the intermediate plate 11. Then, the liquid of H1 depth formed with the liquid level WL and the intermediate plate 11 is made to slosh against a vibration having a long period. Thereafter, the liquid of depth H formed with the liquid level WL and the bottom plate 15 of the vessel 10 is made to slosh against a vibration having a short period. According to the aforesaid construction, vibrations having even different frequencies can be restrained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vibration damping device using a liquid, and more particularly to a vibration damping device using a liquid used to suppress vibrations of high-rise buildings. It is.

[Conventional technology]

BACKGROUND ART In recent years, vibration damping devices have been installed in high-rise buildings being constructed to suppress vibrations of the buildings due to wind, earthquakes, etc.

As shown in FIG. 4, this vibration damping device has conventionally been used to store a liquid 3 such as water in a container 2 placed on a part of a high-rise building 1 where the amplitude is greatest, for example on the roof, at a liquid level 3a (free surface). It is constructed by filling it to form a . When the high-rise building 1 experiences shaking due to wind, earthquakes, etc., the shaking is reduced by the pressure generated as a result of the sloshing of the liquid 3.

[Problem to be solved by the invention]

However, there are problems with vibration damping devices such as those described above. That is, in such a vibration damping device, the sloshing frequency fn is expressed by the following: The length of the container 2 and the height H of the liquid level 3a
Therefore, the sloshing frequency fn is limited.

However, the wind and seismic forces that act on structures contain components in a wide frequency range, and since the bones of actual high-rise buildings are multi-mass points, higher-order modes exist, and prominent vibrations occur at multiple frequencies. It turns out. Therefore, in order to suppress vibrations with different periods, it is necessary to provide a plurality of damping devices with different sloshing frequencies, which not only requires a large installation area but also increases construction costs.

[Means to solve the problem]

The present invention has been made in order to solve the above-mentioned conventional problems, and includes providing a porous intermediate plate in the middle part of the container in the height direction, and forming a liquid level on the upper surface of the intermediate plate. This is a vibration damping device that uses a liquid that is filled with liquid and that allows the sloshing liquid to move up and down via the intermediate plate.

A plurality of porous intermediate plates may be provided vertically apart as required.

Furthermore, this intermediate plate is formed of a semi-permeable member such as a net or a perforated plate.

[For production]

According to a vibration damping device with such a configuration, when vibrations with a large period act on a high-rise building, sloshing vibration occurs in the liquid above the intermediate plate that exists in the middle of the liquid depth, and the high-rise building Suppress the vibration of objects. Furthermore, when vibrations with a small period act, the liquid in the lower layer of the intermediate plate also acts to suppress the vibrations.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vibration damping device using a liquid according to the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of the vibration damping device.

In these figures, inside a box-shaped container 10, an intermediate plate 11 made of a porous material is stretched in the lateral direction (particularly in the horizontal direction). This container 10 is filled with a liquid 12 such as water so that the liquid level WL is above the intermediate plate 11.

Specifically, the length of the container 10 and the depth H of the liquid 12 from the liquid surface to the intermediate plate 11 are such that the sloshing frequency corresponds to the high-frequency vibrations occurring in the high-rise building 1 installed in advance. is set to

The intermediate plate 11 is formed, for example, from a perforated metal plate with a large number of holes 13, as shown in FIG.

The distance H2 between this intermediate plate 11 and the bottom plate 15 of the container 10 is
High-rise buildings are selected to have sloshing vibrations that correspond to relatively small period vibrations.

Specifically, in response to long-period vibrations, sloshing is generated in the fluid at the liquid depth HI, which is formed between the liquid surface and the intermediate plate.
In response to short-period vibrations, sloshing occurs in the fluid at depth H formed between the liquid surface and the bottom plate.

In FIG. 3, two intermediate plates 11a with holes 13a and 11b with holes 13b are used together, and the mutual positions of holes 13a and 13b in intermediate plates 11a and llb are By adjusting the amount of fluid passing through the intermediate plate 11, it is possible to adjust the attenuation of the fluid (adjusting the magnitude of sloshing).

As shown in FIG. 3, two intermediate plates 11a and 11b with openings of the same diameter are stacked, one intermediate plate 11b is fixed, and the other intermediate plate 11b is moved by a device not shown. The aperture ratio of the hole penetrating both 13a and 13b changes. That is, by changing the aperture ratio of the intermediate plate 11 made of a porous material, the attenuation of sloshing can be changed. Further, since the damping of the fluid changes depending on the magnitude of vibration, it is important from the viewpoint of the damping effect to adjust the damping of the fluid depending on the magnitude of the vibration of the structure.

Therefore, when a predicted external force such as a typhoon acts on the high-rise building 1, the aperture ratio of the intermediate plate 11 may be changed in advance according to the expected magnitude of vibration. In the case of vibration caused by vibration, a vibration sensor installed in the high-rise building 1 detects the frequency and amplitude and automatically moves one intermediate plate of the intermediate plate 11 of a multi-plate configuration to adjust the attenuation of sloshing. Configure it as follows.

The intermediate plate 11 is made of a porous material, which can provide flow resistance with a squeezing effect when the lower layer moves toward the upper layer, especially when the lower layer moves toward the upper layer. is necessary. Therefore, it is best for the intermediate plate 11 to be formed of a thin plate material, but depending on the case, it is also possible to use a net.

〔Effect of the invention〕

As is clear from the above description, the vibration damping device using liquid according to the present invention has a porous intermediate plate provided in the middle part of the container in the height direction, and the liquid is The sloshing liquid is configured to be able to move up and down via the intermediate plate.

Therefore, according to the vibration damping device of the present invention, the sloshing frequency can be changed by an extremely simple means of placing an intermediate plate made of a porous material under the liquid surface in a container filled with liquid. Therefore, it is possible to suppress vibrations of different frequencies in high-rise buildings, and as a result, the installation space for the vibration damping device can be saved, and construction costs can be reduced.

[Brief explanation of drawings]

1 to 3 show an embodiment of a vibration damping device using a liquid according to the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a front view of an intermediate plate, and FIG. FIG. 3 is a side sectional view of an intermediate plate having the structure of FIG. FIG. 4 is a side view of a conventional vibration damping device installed on a high-rise building. 1.12... Container 3... Liquid level 13... Intermediate plate 2.14... Liquid 11... Vibration damping device 15... Bottom plate.

Claims (1)

[Claims] A porous intermediate plate is provided in the middle part of the container in the height direction, and the liquid is filled to form a liquid level on the upper surface of the intermediate plate, so that the sloshing liquid can move up and down via the intermediate plate. A vibration damping device that uses liquid.