JPH03144137A - Vertical vibration absorbing device for structure - Google Patents

Abstract

PURPOSE:To enable the simple constitution and enlarge the application range by installing a weight which is movable in the vertical direction by a supporting pillar and has a fluid hole in the vertical direction in a container which is fixed on a structure and filled with liquid and arranging each spring for providing a restoration force in the reverse direction to the shift direction at the upper and lower positions. CONSTITUTION:A container 1 is fixed on a structure and the inside is charged with liquid 2, and a weight 3 which is supported in movable manner in the vertical direction by a supporting pillar 4 is accommodated. A fluid hole 3b in the vertical direction is formed on the weight 3, and each spring 5 is arranged at the upper and lower edge positions, and a restoration force in the reverse direction to the shift direction is generated. Accordingly, the small constitution is obtained by the damping effect around the weight 3 and the parallel relation of the weight 3, and the structure is made simple, and application to a variety of structure is permitted.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is mainly used for civil engineering and structures installed inside building structures to absorb vertical vibrations of floors, roofs, etc. generated by walking or equipment machinery. The present invention relates to a vertical vibration absorbing device.

(Problem to be solved by the invention) Conventional dynamic vibration absorbers that reduce the vertical vibration of structures in the field of architecture and civil engineering are mainly intended for civil engineering structures, such as road bridges, and are designed to reduce the resonance caused by automobiles passing through them. The purpose is to prevent an increase in shaking due to
Vibration reduction measures for elevated bridges (Part 1) to (Part 3)”
(Kajiyo, Okino.

Yoshikawa et al.) 43rd Annual Academic Conference of the Japan Society of Civil Engineers, ``Countermeasures using dynamic vibration absorbers for low-frequency noise generated from road bridges'' (Shirai 1
Ishino, Tanabe) Proceedings of the Japan Noise Control Engineering Technology Conference (
(See 1981).

This type of dynamic vibration absorber consists of a weight that moves up and down with the vibration of the bridge, a spring that supports it, and an oil damper that acts as a damper. The structure has a natural frequency that matches the frequency of the bridge, and the weight resonates with the bridge to reduce the vibrations of the bridge when it vibrates due to passing cars.

In the case of architectural structures, especially long-span buildings that are prone to vibration disturbances, it is generally necessary to increase the rigidity of the floor or increase its weight in order to suppress the discomfort caused by vibration to pedestrians. However, the installation of a device aimed at reducing this microvibration has not been considered in the past.

The minute vibrations that occur in architectural structures are caused by moving loads, which is similar to that of road bridges, so installing the above-mentioned dynamic vibration absorbers can be considered, but in the dynamic vibration absorbers used in road bridges, the horizontal Because directional stability is maintained by springs as in the vertical direction, it is difficult to insulate friction from the minute vibrations that are unique to buildings. Since the weight is connected in series with the weight, the structure of the device is high, and the installation location is limited, making it difficult to apply to buildings.

This invention was made in light of this background, and aims to propose a new vibration absorber that has a small precept, is suitable for buildings, and can be applied to a variety of structures.

(Means for Solving the Problems) In the present invention, a container is filled with liquid, and the liquid is made to flow when a weight also stored in the container moves relative to the container, and during this flow, the liquid is caused to move against the weight. By using the acting viscous resistance as a damper, the device is constructed with a weight and damper arranged in parallel, which simplifies the structure and at the same time
Aim to downsize the device.

The weight is restrained in the horizontal direction by a column that passes vertically through it and is fixed to the container, ensuring horizontal stability, and smooth vertical movement due to the liquid filled in the container. When the friction is insulated.

The device consists of a container that is fixed to a structure, a liquid filled in the container, and a column that is fixed vertically within the container at a distance from the top and bottom ends of the container and moves vertically relative to the container. It consists of a weight that is stored in a ready state, and springs that are placed at the upper and lower ends of the weight and apply a restoring force in the opposite direction to the movement direction of the weight when it moves, so that the weight resonates with the structure. This absorbs the vibrations of the structure, and at the same time, the weight receives viscous resistance due to the movement of the liquid and is immediately damped.

(Example) The present invention will be explained below based on the drawings showing one embodiment.

As shown in FIGS. 1 and 2, the vertical vibration absorbing device A of the present invention includes a container 1 fixed to a structure, a liquid 2 filled in the container, and a container 1 that is housed in a vertically movable manner. weight 3
It is composed of a column 4 that guides the vertical movement of the weight 3, and a spring 5 that returns the weight 3 when it moves, and absorbs vibrations of the structure.

The mass m of the weight 3 is adjusted within the range of 1/200 to 1150 of the mass M of the structure, which is most likely to resonate without affecting the weight of the structure, and the natural circular frequency ω is tuned to the structure. It is set to a value that satisfies the relationship ω=Ω/(1+m/M), which takes the optimum tuning by setting the natural circular frequency of the structure to Ω.

As shown in the figure, there are weights 3 in the vertical direction at multiple locations in the container 1.
A column 4 is fixed to restrain the horizontal movement of the column, and a spring 5 is wound around each end of the column to return the weight 3 to its original position when the weight 3 moves. It is inserted into the support column 4 through the hole 3a, and is housed inside the container 1 at a distance from the upper and lower ends with the upper and lower ends sandwiched between the springs 5.5.

The weight 3 also has a small cross-section flow hole 3 that passes through it in the vertical direction.
A plurality of flow holes 3b are opened, and the liquid 2 passes through these flow holes 3b as the weight 3 moves relative to each other.

When the liquid 2 passes through the flow hole 3b, it is subjected to viscous resistance corresponding to its velocity, and this resistance is conversely applied to the weight 3, causing the weight 3 to
to stand still.

The flow hole 3b and the insertion hole 3a through which the support column 4 is inserted are arranged in a drum-like shape from the center so that the weight 3 can smoothly respond even to minute vibrations of the structure. It has a cross-sectional shape with a curvature that gradually expands in diameter toward the top and bottom ends.

When the structure vibrates, the weight 3 vibrates while moving relative to the container 1, which vibrates together with the structure, and resonates with the structure according to the circular frequency set as described above. Vibration of the structure is absorbed by this resonance, and at the same time, the liquid 2 existing on the moving direction side of the weight 3 passes through the flow hole 3b of the weight 3, and as described above, a viscous resistance corresponding to the moving speed at that time is generated. It acts on the weight 3, and the vibration of the weight 3 is immediately damped. The arrow in Figure 2 indicates the liquid 2 when the weight 3 rises relative to the container l.
The flow is shown below.

The viscous resistance caused by the passage of the liquid 2 through the flow holes 3b functions as a damper as a vibration absorber.

The amount of attenuation is adjusted by changing the area of the minimum cross section of the flow hole 3b or by placing porous plates above and below the flow hole 3b, and the optimal amount of attenuation is given by the following formula. .

The weight 3, which has come to rest due to the flow of the liquid 2, is immediately returned to its original position by the spring 5, and repeats the vibration.

The weight 3 is made of a material that has a high specific gravity relative to the liquid 2, such as a steel plate, and a material whose viscosity coefficient is not susceptible to temperature fluctuations, such as silicone oil, is suitable for the liquid 2.

(Effects of the Invention) The present invention is as described above, and is configured by filling the liquid acting as a damper around the weight that serves as the main body of the dynamic vibration absorber, so that the weight and the damper are connected. They are in a parallel relationship and can be kept small, making the scale smaller and at the same time making it possible to greatly simplify the structure as a dynamic vibration absorber.

As a result, the construction, including the ceiling and under the floor of the building,
It can be installed in any relatively small space in all types of civil engineering structures, and in particular, it can respond smoothly to minute vibrations due to the flow holes in the curved weight, making it ideal for buildings and other structures. Unpleasant vibrations on the floor of a pedestrian bridge can be effectively eliminated.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the configuration of the present invention, Figure 2-1,
II are sectional views taken along lines X-X and Y-Y, respectively. A... Vertical vibration absorber, 1... Container, 2... Liquid, 3... Weight, 3a...
...Insertion hole, 3b...Flow hole, 4...
...Strut, 5...Spring.

Claims (1)

[Claims] (1) A container that is fixed to a structure, a liquid that is filled in the container, and a column that is placed at a distance from the top and bottom ends of the container and that is vertically fixed inside the container to move the container up and down with respect to the container. It consists of a weight that is stored in a movable state, and springs that are placed at the upper and lower ends of the weight and provide a restoring force in the opposite direction to the movement direction of the weight when the weight moves. 1. A vertical vibration absorbing device for a structure, characterized by having flow holes through which water can pass.