JPH04105233U - Vibration damping device - Google Patents

Abstract

(57) [Summary] [Purpose] Equipped with a pair of rigid tanks and a horizontal tank that is installed between the same pair of rigid tanks and communicates with each of the rigid tanks, and the inside is filled with liquid and communicates in a U-shape. To lower the natural frequency of a vibration damping device constituting a tank without enlarging its main body. [Structure] A partition wall is provided between each vertical tank and a horizontal tank to prevent direct communication, and the lower part of each vertical tank and the lower part of the horizontal tank adjacent to the same rigid tank are connected downwardly. It was communicated via a detour route that was extended to and communicated with.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention can be used to damp the vibrations of the superstructure of ships and land structures such as buildings and large steel structures. The present invention relates to a suitable vibration damping device.

0002

[Conventional technology]

Dynamic vibration absorbers have been known as one type of vibration isolating means for structures. The basic configuration of the dynamic vibration absorber is shown in FIG. It is determined by If the mass of the vibrator 10 and the rigidity of the spring 11 are appropriately selected to match the natural frequency of the dynamic vibration absorber with the frequency f _o of the structure, the structure will be The vibration changes from the characteristic shown by the solid line to that shown by the broken line, and a vibration reduction effect can be obtained.

0003 In addition, the vibration damping device used for ship vibration damping measures is as shown in the vertical section in Figure 5. It uses water from a shape-shaped communication tank. The water in the tank moves in the direction of the arrow and its natural circumference The period (natural frequency) is uniquely determined once the size of the tank is determined. In this case as well, By matching the natural frequency of the vibration damping device to the vibration frequency of the ship, the dynamic vibration damping device can be You can get the same vibration reduction effect as a container.

0004

[Problem that the idea aims to solve]

The above-mentioned dynamic vibration reducer has the following problems. (a) The amplitude of the vibrator increases and there is concern about the strength of the spring. (b) It is difficult to design and manufacture the spring mechanism for large dynamic vibration absorbers. (c) To adjust the frequency, it is necessary to change the mass and spring stiffness of the vibrator, especially for large ones. This cannot be done easily.

[0005] On the other hand, in order to lower the natural frequency of a U-shaped communication tank, the size of the tank must be Modeling is required.

[0006] The present invention eliminates the drawbacks of the conventional vibration damping devices mentioned above and has the advantage of not using springs. Based on the U-shaped communication tank, it has a low natural frequency without increasing the size. The purpose of this invention is to provide a vibration damping device that

[0007]

[Means to solve the problem]

This invention solves the above problem, and consists of a pair of rigid tanks and an identical pair of rigid tanks. A horizontal tank is installed between the vertical tanks and communicates with each vertical tank. In a vibration damping device whose body is filled to constitute a U-shaped communication tank, each of the rigid tanks and a horizontal tank, each of which has a partition wall that prevents direct communication between the vertical tank and the horizontal tank. and the lower part of the horizontal tank adjacent to the same rigid tank extend downward, respectively. relates to a vibration damping device characterized in that the vibration damping device is connected via a detour path that is connected to the vibration damping device; It is something to do.

[0008]

[Effect]

In a U-shaped communication tank, if the equivalent length between the liquid levels of both vertical tanks is increased, The natural frequency can be reduced. In this invention, the main body of the U-shaped communication tank By providing an extended detour at the bottom without increasing the dimensions, the equivalent length can be substantially increased. This reduces the natural frequency.

[0009]

【Example】

FIG. 1 is a sectional view of an embodiment of the present invention. In the figure, 4a and 4b are respectively Rigid tank, 1 is a horizontal tank that communicates the above two rigid tanks, 2 is a tank that is filled with the above tank. The liquids 13a and 13b are directly adjacent to each vertical tank and horizontal tank. Partition walls 3a and 3b are provided to prevent communication, and extend below the partition walls. A long detour that bypasses a section blocked by a partition wall. Department. 6a and 6b are the air chambers at the top of the rigid tank, and 5a and 5b are the air chambers that communicate with each other. A communication pipe 5 supplies air to the air chambers 6a and 6b and changes the air chamber pressure. The air supply pipe 7 is a valve for shutting off the flow of the pipe 5. 9 8 is an air vent valve for venting residual air in the horizontal tank 1, and 8 is a mounting base. Also L is the equivalent length measured along the direction of liquid movement between the liquid levels of both rigid tanks. . The device as a whole constitutes a U-shaped communication tank.

0010 The natural frequency f of the U-shaped communication tank is expressed by the following formula when valve 7 is open. .

[0011]

[Math 1]

0012 however, g: gravitational acceleration L: equivalent length In other words, increasing the equivalent length L will decrease the natural frequency (increase the vibration period). be able to. This example is implemented by providing a detour extending below the rigid tank. Therefore, the equivalent length can be increased, so the main body of the conventional U-shaped communication tank can be If the length, width and depth dimensions of (excluding the detour) are the same, the It is possible to reduce the natural frequency (increase the period). Therefore, the U-shaped communication It is possible to provide a damping device with a low natural frequency without increasing the size of the main body of the link. can.

[0013]

[Effect of the idea]

In the vibration damping device of the present invention, there is a direct connection between each vertical tank and the horizontal tank. The lower part of each rigid tank and the horizontal area adjacent to the same rigid tank have a partition wall to prevent the passage of water. The lower part of the tank communicates with each other via a detour that extends downward and communicates with the lower part of the tank. Therefore, it is possible to create a control system with a low natural frequency without increasing the size of the U-shaped communication tank. A shaking device can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a diagram comparing the effects of the above embodiment and a conventional U-shaped damping tank.

FIG. 3 is an explanatory diagram of the action of the dynamic vibration absorber.

FIG. 4 is a sectional view of a dynamic vibration absorber as a first example of a conventional vibration damping device.

FIG. 5 is a sectional view of a U-shaped restriction tank as a second example of a conventional vibration damping device.

[Explanation of symbols]

1 horizontal tank 2 liquid 3a, 3b Detour 4a, 4b Rigid tank 5 Air supply piping 5a, 5b communication piping 6a, 6b air chamber 7 Valve 8 Installation stand 9 Air vent valve 10 Oscillator 11 Spring 12 Support stand 13a, 13b partition wall

Claims (1)

[Scope of utility model registration request] Claim 1: A pair of rigid tanks, and a horizontal tank provided between the same pair of rigid tanks and communicating with each of the rigid tanks, the interior of which is filled with liquid to form a U-shaped communication tank. The vibration damping device includes a partition wall that prevents direct communication between each of the rigid tanks and the horizontal tank, and the lower part of each of the rigid tanks and the lower part of the horizontal tank adjacent to the same rigid tank. A vibration damping device characterized in that the two are connected to each other via detours extending downward and communicating with each other.