JP7423431B2 - dynamic vibration absorber - Google Patents

Description

The present invention relates to a dynamic vibration absorber.

A dynamic vibration damper (TMD: Tuned Mass Damper) is known as a device that reduces the shaking of structures due to wind or earthquakes.
Dynamic vibration absorbers install a weight supported by a spring mechanism on a structure, and by synchronizing the natural period of this weight and spring mechanism with the natural period of the structure, the response (swaying) of the structure can be greatly reduced. (For example, see Patent Documents 1 and 2). The spring mechanism uses laminated rubber or the restoring force of a pendulum suspended from a weight.

Japanese Patent Application Publication No. 2002-48187 Japanese Patent Application Publication No. 10-266626

If the natural period of a structure is different in two horizontal directions (X direction, Y direction), a weight and a spring mechanism should be installed in each direction in order to tune the dynamic vibration absorber to the natural period in each direction. Or, it is necessary to add a spring or mass that is effective only in one direction. For this reason, when the natural period of the structure is different in two horizontal directions, there is a problem that the dynamic vibration damping device has a complicated structure and is expensive.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a dynamic vibration damping device that can be inexpensive and have a simple configuration.

In order to achieve the above object, a dynamic vibration absorbing device according to the present invention includes a support section installed in a structure, and a pendulum section that is suspended from the support section and makes a pendulum movement, and the pendulum of the pendulum section In a dynamic vibration absorbing device that reduces vibration of the structure by synchronizing a natural period of motion with a natural period of the structure, the pendulum part includes a weight, a hanging member connecting the support part and the weight, The hanging member has an upper hanging member rotatably connected to the supporting portion via a first shaft portion about a first axis extending in a first horizontal direction, and the upper hanging member has the first a lower suspension member connected via a second shaft portion so as to be rotatable about a second axis extending in a second horizontal direction intersecting the horizontal direction, and to which the weight is connected, the lower suspension member of the pendulum portion; 1. A natural period in the horizontal direction is tuned to the natural period in the first horizontal direction of the structure, and a natural period in the second horizontal direction of the pendulum part is adjusted to be the natural period in the second horizontal direction of the structure. The length from the first shaft part to the center of the weight and the length from the second shaft part to the center of the weight are set so as to synchronize the weight .

In the present invention, the natural period of the pendulum portion can be set to different values in the first horizontal direction and the second horizontal direction. As a result, in a structure having different natural periods in the first horizontal direction and the second horizontal direction, the first horizontal direction of the pendulum part is equal to the natural period in the first horizontal direction and the natural period in the second horizontal direction of the structure. By synchronizing the natural period and the natural period in the second horizontal direction, it is possible to reduce the shaking of the structure in the first horizontal direction and the second horizontal direction due to cold, earthquake, etc.
In this manner, in the present invention, the shaking of the structure in the first horizontal direction and the second horizontal direction can be reduced using the same dynamic vibration absorbing device. For this reason, compared to installing dynamic vibration absorbers or installing additional springs or additional masses in response to vibrations of the structure in the first horizontal direction and the second horizontal direction, it is better to use dynamic vibration absorbers. It is possible to have an inexpensive and simple configuration. Furthermore, since the dynamic vibration absorber can have a simple configuration, it is possible to downsize the dynamic vibration absorber and reduce the installation space of the dynamic vibration absorber.

Further, in the dynamic vibration absorbing device according to the present invention, a plurality of the hanging members are provided, and the weight is rotatably joined to the lower hanging member of each of the plurality of hanging members.
With such a configuration, when the weight is supported by a plurality of hanging members, the pendulum part rotates around the first axis, and the upper hanging members of each of the plurality of hanging members rotate around the first axis. At this time, the weight rotates about an axis parallel to the first axis with respect to the plurality of hanging members. As a result, rotation of the upper hanging member about the first axis is not inhibited, and it is possible to suppress generation of a bending moment at the connecting portion between the upper hanging member and the lower hanging member.

Further, the dynamic vibration absorbing device according to the present invention may include a damping device that is provided between the weight and the structure and damps the swing of the weight with respect to the structure.
With such a configuration, the swing (amplitude) of the weight relative to the structure can be appropriately controlled.

According to the present invention, a dynamic vibration damping device can be configured to be inexpensive and simple.

FIG. 1 is a diagram showing an example of the dynamic vibration damping device according to the first embodiment of the present invention as seen from the Y direction. 1 is a diagram showing an example of a dynamic vibration damping device according to a first embodiment of the present invention as seen from the X direction. It is a perspective view of a pendulum part. It is a figure seen from the Y direction showing an example of a dynamic vibration absorption device by a 2nd embodiment of the present invention. It is a figure seen from the X direction showing an example of the dynamic vibration absorption device by a 2nd embodiment of the present invention.

(First embodiment)
Hereinafter, a dynamic vibration damping device according to a first embodiment of the present invention will be described based on FIGS. 1 to 3.
As shown in FIGS. 1 and 2, the dynamic vibration damping device 1 according to the first embodiment is installed on a structure 2 such as a building, and is configured to reduce vibrations caused by wind or earthquakes. In the following, two intersecting horizontal directions will be referred to as the X direction (direction of arrow X in the drawing, second horizontal direction) and the Y direction (direction of arrow Y in the drawing, first horizontal direction). In the drawings, the vertical direction is indicated by the direction of arrow Z. The X direction and the Y direction are orthogonal directions.
In this embodiment, the natural period of the structure 2 is different in the X direction and the Y direction. The natural period in the X direction is T _x , the natural period in the Y direction is T _y , and T _x >T _y .

The dynamic vibration absorbing device 1 includes a support section 3 installed on a structure 2, and a pendulum section 4 suspended from the support section 3 and making a pendulum movement. The dynamic vibration absorbing device 1 is configured to synchronize the natural period of the pendulum motion of the pendulum portion 4 with the natural period of the structure 2, and reduce the vibration of the structure 2.
The support portion 3 includes a plurality of pillar members 31 installed at intervals in the X direction and the Y direction, and a beam member 32 constructed between the upper end portions of the pillar members 31. The beam members 32 may be installed between the beam members 32 installed on the pillar members 31. In this embodiment, the support portion 3 is a turret.

As shown in FIGS. 1 to 3, the pendulum portion 4 is suspended from a beam member 32. As shown in FIGS. The pendulum portion 4 includes a weight 5 and a hanging member 6 that connects the beam member 32 and the weight 5. The weight 5 has a predetermined mass.
The hanging material 6 includes an upper hanging material 61 and a lower hanging material 62. The upper hanging member 61 and the lower hanging member 62 are each formed into a plate shape or a rod shape.

The upper hanging member 61 has one end (referred to as a first end 61a, see FIG. 3) connected to the beam member 32 via a first shaft portion 71, and the other end (referred to as a second end 61b). (see FIG. 3) is located further away from the beam member 32 than the first end portion 61a.
The lower hanging member 62 has one end (referred to as a first end 62a, see FIG. 3) connected to the second end 61b of the upper hanging member 61 via the second shaft portion 72, and the other end. The second end 62b (see FIG. 3) is located further away from the upper hanging member 61 than the first end 62a. A weight 5 is connected to the second end 62b of the lower hanging member 62.

The first shaft portion 71 is fixed to the beam member 32 and supports the upper hanging member 61 so as to be rotatable around a first axis 71a extending in the Y direction. The first shaft portion 71 is composed of, for example, a rotating pin.
In the initial state when the pendulum part 4 is stationary, the upper hanging member 61 is installed in such a direction that the first end 61a is on the upper side and the second end 61b is on the lower side. The upper hanging member 61 is configured not to rotate other than around the first axis 71a with respect to the structure 2 (support portion 3).
The second shaft portion 72 is fixed to the second end 61b of the upper hanging member 61, and supports the lower hanging member 62 so as to be rotatable around a second axis 72a extending in the X direction. The second shaft portion 72 is composed of, for example, a rotating pin.
In the initial state when the pendulum part 4 is stationary, the lower hanging member 62 is installed in such a direction that the first end 62a is on the upper side and the second end 62b is on the lower side. The lower hanging member 62 is configured not to rotate other than around the second axis 72a.
If the length from the first shaft part 71 to the center of the weight 5 in the initial state is _L1 , and the length from the second shaft part 72 to the center of the weight 5 is _L2 , then _L1 > _L2 .

The weight 5 is joined to the second end 62b of the lower hanging member 62. In this embodiment, the weight 5 and the lower hanging member 62 are rigidly connected and integrated. One weight 5 is joined to and supported by one hanging member 6.
In this embodiment, a damping device 8 such as an oil damper is provided between the weight 5 and the structure 2.

In the pendulum portion 4, when an external force in the X direction acts on the weight 5 and the weight 5 is displaced in the X direction, the weight 5 rotates (swings) around the first shaft portion 71. The upper hanging member 61 rotates around the first shaft portion 71. The lower hanging member 62 rotates around the first shaft portion 71 together with the upper hanging member 61 . At this time, the pendulum length of the weight 5 is _L1 .
In the pendulum portion 4, when an external force in the Y direction acts on the weight 5 and the weight 5 is displaced in the Y direction, the weight 5 rotates around the second shaft portion 72. The lower hanging member 62 rotates around the second shaft portion 72 . The upper hanging member 61 is not displaced. At this time, the pendulum length of the weight 5 is _L2 .

When the weight 5 rotates in the X direction (rotates around the first shaft portion 71), the natural period T1 of the pendulum portion ₄ is expressed by the following equation (1), where g is the gravitational acceleration.

When the weight 5 rotates in the Y direction (rotates around the second shaft portion 72), the natural period T2 of the pendulum portion ₄ is expressed by the following equation (2), where g is the gravitational acceleration.

In this way, the pendulum section 4 has different natural periods in the X direction and the Y direction.
In this embodiment, since L ₁ >L ₂ holds, the natural period T ₁ of the pendulum portion 4 has a value larger than the natural period T ₂ (T ₁ >T ₂ ).
The natural period T ₁ of the pendulum part 4 in the X direction is tuned to the natural period T _x of the structure 2 in the X direction, and the natural period T ₂ of the pendulum part 4 in the Y direction is tuned to the natural period T _y of the structure 2 in the Y direction. Set the lengths of L ₁ and L ₂ so that they are tuned to . Thereby, the dynamic vibration damping device 1 can tune to the natural period of the structure 2 and reduce vibrations caused by wind or earthquakes occurring in the structure 2.

Next, the functions and effects of the dynamic vibration damping device 1 according to the first embodiment will be explained.
In the dynamic vibration absorbing device 1 according to the first embodiment, the natural period of the pendulum portion 4 can be set to different values in the X direction and the Y direction, so that the It is possible to reduce vibrations in both the direction and the Y direction with one unit. Therefore, compared to installing multiple dynamic vibration absorbers 1 corresponding to shaking in the X direction and Y direction, or installing additional springs or additional masses, the dynamic vibration absorber 1 can be configured at a lower cost and simpler. It can be done. Moreover, the dynamic vibration damping device 1 can be made into a compact device.

In the dynamic vibration absorption device 1 according to the first embodiment, by providing a damping device 8 such as an oil damper between the weight 5 and the structure 2, the vibration (amplitude) of the structure 2 and the weight 5 can be appropriately controlled. Can be done.
Note that this optimal attenuation amount can be set using fixed point theory or the like.

(Second embodiment)
Next, a second embodiment will be described based on the attached drawings, and the same or similar members and parts as those in the first embodiment will be designated by the same reference numerals and explanations will be omitted. Different configurations will be explained.
In the dynamic vibration absorber 1 of the first embodiment shown in FIGS. 1 and 2, one weight 5 is connected to the support part 3 via one hanging member 6. On the other hand, as shown in FIGS. 4 and 5, in the dynamic vibration absorber 1B of the second embodiment, one weight 5 is connected to the support part 3 via two hanging members 6.
Also in the second embodiment, when an external force in the X direction acts on the weight 5 and the weight 5 is displaced in the X direction, the pendulum length of the weight 5 is L ₁ , and an external force in the Y direction acts on the weight 5. The pendulum length of the weight 5 when the weight 5 is displaced in the Y direction is _L2 .
The weight 5 is rotatably joined to the lower end of the lower hanging member 62 of each of the two hanging members 6. In order to rotatably join the weight 5 to the lower suspension member 62, it is preferable to use a universal joint, a short wire, or the like that does not restrict rotation around the X-axis and the Y-axis. Thereby, the weight of the weight 5 is smoothly transmitted to the hanging member 6.
Since the weight 5 is in a state where it is rotatable relative to the lower hanging member 62, it is rotatably displaced relative to the lower hanging member 62 along with displacement in the X direction or the Y direction.

The dynamic vibration damping device 1B according to the second embodiment described above has the same effects as the first embodiment.
In the dynamic vibration absorber 1B according to the second embodiment, the weight 5 is rotatably joined to the two lower hanging members 62. As a result, when the pendulum part 4 rotates around the first axis 71a and the upper hanging members 61 of the two hanging members 6 rotate around the first axis 71a, the weight 5 moves against the two lower hanging members 62. can be rotated around an axis parallel to the first axis 71a. As a result, rotation of the two upper hanging members 61 around the first axis rotation 71a is not blocked, and bending moment is suppressed from acting on the connecting portion between the upper hanging members 61 and the lower hanging members 62. Can be done. Note that when the pendulum part 4 is displaced around the second axis 72a, the weight 5 rotates with respect to the lower hanging member 62, so that the second axis 72a is attached to the connection part between the upper hanging member 61 and the support part 3. Although a bending moment acts around it, since the angle of inclination of the hanging member 6 with respect to the vertical direction is small, the bending moment is also small. Therefore, it is easy to design the joint between the upper suspension member 61 and the beam member 32 to accommodate the bending moment about the second axis 72a.
Furthermore, since one weight 5 can be supported by a plurality of hanging materials 6, it is only necessary to change the quantity of the hanging materials 6 according to the weight and shape of the weight 5, and there is no need to change the strength or structure of the hanging materials 6. .

Although the embodiments of the dynamic vibration damping device according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit thereof.
For example, in the above embodiment, a damping device 8 such as an oil damper is provided between the weight 5 and the structure 2, but the damping device 8 may not be provided. In this case, a displacement limiting mechanism such as a stopper is separately added to prevent the displacement of the weight 5 from becoming excessive. Further, the damping device 8 may be installed at a location other than the above, such as between the pillar 31 of the support portion 3 and the weight 5.

In the above embodiment, the natural period in the X direction is T _x and the natural period in the Y direction is larger than T _y ; however, the natural period in the Y direction is T _y and the natural period in the X direction is larger than T _x . It's okay. In such a case, change the directions of the dynamic vibration absorbers 1 and 1B in the X and Y directions so that the natural period T ₂ of the pendulum section 4 in the Y direction is larger than the natural period T ₁ of the pendulum section 4 in the X direction. I will make it happen.

In the above embodiment, the dynamic vibration absorbers 1 and 1B are installed on the structure 2, but this does not necessarily mean that they are installed on the top of the structure 2. The dynamic vibration absorbers 1 and 1B may be installed on the top (rooftop) of a structure 2 such as a high-rise building, but they may also be installed inside the building on a mid-floor of the structure 2. However, since the dynamic vibration absorbers 1 and 1B are vibration damping devices that utilize the vibration of the weight 5 due to acceleration at the installation location, the vibration damping effect is better when installed on higher floors than on lower floors where the shaking is small. It is necessary to set the installation location keeping in mind that it is expensive.

In the first embodiment described above, one weight 5 is connected to the support part 3 through one hanging material 6, and in the second embodiment, one weight 5 is connected to the support part 3 through two hanging materials 6. is connected to. On the other hand, one weight 5 may be connected to the support part 3 via three or more hanging members 6.
In the above embodiment, the support part 3 is a tower made of the pillar material 31 and the beam material 32, but it may have a structure other than the above as long as it is supported by the structure 2 and can support the pendulum part 4. It's okay.

In the above embodiment, the first horizontal direction in which the first axis 71a extends is the Y direction, the second horizontal direction in which the second axis 72a extends is the X direction, and the first horizontal direction and the second horizontal direction are orthogonal. However, the first horizontal direction and the second horizontal direction do not necessarily have to be orthogonal.
In addition, in this embodiment, since the X direction and the Y direction, which are the main axes in the horizontal plane of a general building, are perpendicular to each other, the first horizontal direction and the second horizontal direction are defined as the X direction and the Y direction of the building. By doing so, the natural period of the pendulum part can be tuned to the natural period of the building in the X direction and the Y direction.

In the first embodiment described above, the weight 5 and the lower suspension member 62 are rigidly joined, but may be rotatably joined.

1, 1B Dynamic vibration absorber 2 Structure 3 Support part 4 Pendulum part 5 Weight 6 Hanging member 8 Damping device 61 Upper hanging member 62 Lower hanging member 71a First axis 72a Second axis

Claims (3)

a support installed in the structure;
a pendulum part that is suspended from the support part and makes a pendulum movement,
A dynamic vibration absorber that reduces vibrations of the structure by synchronizing the natural period of the pendulum motion of the pendulum part with the natural period of the structure,
The pendulum part is
A weight and
a hanging member connecting the support part and the weight,
The hanging material is
an upper hanging member rotatably connected to the support portion via a first shaft portion about a first axis extending in a first horizontal direction;
A lower hanging member is connected to the upper hanging member via a second shaft part so as to be rotatable about a second axis extending in a second horizontal direction intersecting the first horizontal direction, and the lower hanging member is connected to the weight. death,
The natural period in the first horizontal direction of the pendulum part is tuned to the natural period in the first horizontal direction of the structure, and the natural period in the second horizontal direction of the pendulum part is tuned to the natural period in the second horizontal direction of the structure. Dynamic vibration absorption characterized in that the length from the first shaft part to the center of the weight and the length from the second shaft part to the center of the weight are set so as to be synchronized with the natural period in the horizontal direction. Device. A plurality of the hanging materials are provided,
The dynamic vibration absorbing device according to claim 1, wherein the weight is rotatably joined to the lower hanging member of each of the plurality of hanging members. 3. The dynamic vibration absorption device according to claim 1, further comprising a damping device provided between the weight and the structure to damp vibration of the weight with respect to the structure.

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