JPH0239062Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a dynamic vibration absorber for absorbing vibrations of structures.

Conventional configuration Conventionally, dynamic vibration absorbers for structures include, for example,
There is one that can be found in Japanese Patent Application Laid-Open No. 59-50243.
This device has a long support handle that is cantilevered and vibratingly attached to a vibrated object that is subjected to forced vibration, and a support handle that is movable to change the distance from the fulcrum of the support handle. It is composed of a weight that is attached and can increase or decrease the natural frequency of the support shaft vibration system as the weight moves, and means for moving the weight in accordance with changes in the frequency of the vibrated body. be.

Problems to be Solved by the Invention According to the above-mentioned conventional configuration, the vibration direction in which the target structure is absorbed is limited to the vibration direction of the support handle. However, since the vibrations that act on structures usually include vibrations with various directional components,
The conventional vibration absorber described above did not have a sufficient vibration absorption effect.

Therefore, an object of the present invention is to provide a dynamic vibration absorber that can solve the above problems.

Means for Solving the Problems In order to solve the above problems, the dynamic vibration absorber of the present invention fixes a support body having an air chamber inside inside a container, and also provides space inside and outside the space chamber around the lower part of the support body. A liquid is placed in the container, and at least three threaded rods are installed at equal angles and radially around the support at a position above the surface of the liquid, and each of the threaded rods is provided with a , weights are screwed into the liquid so that their positions can be adjusted, and fluid resistance objects are suspended from each of the weights into the liquid.

Function First, a vibration absorber is placed and fixed on a vibrating structure. Next, the positions of the weights are adjusted so that the natural frequency of each vibration system consisting of the threaded rod, weight, and fluid resistance object matches the frequency of the structure. At this time, if the vibration of the structure has a single frequency, it is sufficient to adjust the positions of all the weights to the same place, and if the vibration has multiple frequencies, the threaded rod, The natural frequency of each vibration system consisting of a weight and a fluid resistance object is made to match the frequency of the directional component of vibration corresponding to that vibration system. Then, the vibration of the structure is transmitted to the threaded rod through the container and the support, and the vibration is damped by the resistance of the weight and the fluid resistance object. Furthermore, the damping liquid is also transmitted between the space chamber and the container through the passage. Although it moves freely, the air pressure in the air chamber and the throttling effect when passing through the passage create the function of a fluid damper, and the overall damping effect is very good.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Reference numeral 1 denotes a circular container capable of containing a damping liquid, which can be placed and fixed on a vibrating structure 2. Reference numeral 3 denotes a cylindrical support erected at the center of the bottom surface of the container 1. A space chamber 4 is formed inside the support 3, and space chambers 4 are formed at multiple locations (for example, 3 locations) around the lower part of the support 3. A passage 5 is formed that communicates the container 4 with the container 1 side.
Reference numeral 6 denotes a through hole formed in the upper part of the support body 3 for communicating the air chamber 4 to the atmospheric pressure side, and a pressure gauge 7 and a stop valve (not shown) are attached to the through hole. Reference numeral 8 denotes eight vibrating threaded rods that are mounted radially in the horizontal direction at equal angles around the upper part of the support body 3. The attachment is carried out by screwing the vibrating screw rod 8 into the screw hole 3a of the support 3 and then fixing it with a fixing nut 9. Reference numeral 10 denotes an annular weight screwed onto the vibrating threaded rod 8, and its position can be adjusted by rotating the weight 10. 11 is a nut for fixing the same.
Reference numeral 12 is a fluid resistance object hanging downwardly into the container 1 from each of the weights 10, and is composed of a rod 13 directly fixed to the weight 10, and a circular horizontal plate 14 fixed to the lower end of this rod 13. There is. In this configuration, a damping liquid A is placed in the container 1. Note that the amount of liquid is determined by the fluid resistance object 12.
It is assumed that the horizontal plate 14 is touched but the weight 10 is not touched. Also, at this time, the air B is made to remain in the space chamber 4.

Next, the effect will be explained.

First, the vibration absorber is fixed to the structure 2 which is vibrating at a predetermined frequency via bolts or the like. Next, the natural frequency of each vibration system consisting of the vibrating threaded rod 8, the weight 10, and the fluid resistance object 12 is determined by the structure 2.
Adjust the position of the weight 10 so that it matches the frequency of the vibration. At this time, if the vibration of the structure 2 has a single frequency, it is sufficient to adjust the positions of all the weights 10 to the same place, and if the vibration has multiple frequencies, the vibration threaded rod 8,
The natural frequency of each vibration system consisting of the weight 10 and the fluid resistance object 12 is made to match the frequency of the directional component of vibration corresponding to that vibration system. Then, the vibration of the structure 2 is transmitted to the vibrating screw rod 8 via the container 1 and the support 3, and the weight 10 and the liquid resistor 1
The vibration is damped by the resistance of 2, and the damping liquid A also moves freely within the space chamber 4 and the container 1 through the passage 5, but when the air pressure in the air chamber 4 and the passage 5 pass through the passage 5. Due to the throttling action of the fluid damper, the damping effect as a whole is very good. Of course, since the vibrating screw rods 8 are provided at equal angles around the entire periphery, it is possible to cope with each direction component of the vibration acting on the structure 2, and
Various vibration frequencies can also be handled.

Note that the structures may include general building structures, devices installed in ships, general equipment installed on the ground, and the like.

In addition, the vibration absorber above has a horizontal vibration direction,
It can be used in all cases, including vertical and torsional directions.

Effects of the invention According to the configuration of the invention described above, by adjusting the position of the weights of each threaded rod provided around the support, it is possible to attenuate vibrations in each direction component of vibrations acting on the structure. In addition, even if the vibration frequencies of each direction component are different, by adjusting the position of the weight accordingly, it is possible to exert a damping effect on each vibration frequency. The damper function due to the movement between the space chamber and the container has an excellent damping effect on the structure as a whole.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway overall front view, and FIG. 2 is an overall plan view. 1... Container, 2... Structure, 3... Support, 4
... Space chamber, 5 ... Passage, 8 ... Vibrating screw rod, 9
... Nut, 10 ... Weight, 12 ... Fluid resistance object, 13 ... Rod body, 14 ... Horizontal plate.

Claims (1)

[Scope of utility model registration request] A support body having an air chamber inside is fixed in a container, and a passage communicating between the inside and outside of the space chamber is formed around the lower part of the support body, and a liquid is put into the container and a position above the surface of the liquid is formed. At least three threaded rods are installed around the support at equal angles and radially, weights are screwed into each of the threaded rods so that the position can be adjusted, and a fluid resistance object is inserted into the liquid from each of the weights. A dynamic vibration absorber characterized by hanging.