JPH10288241A - Vibration damping device for pole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deal with earthquake vibration or even shaking over secondary vibration mode so as to make possible effective vibration damping action by constituting a damping device so that a vessel in which viscous fluid is contained is received in an outside vessel capably of colliding with the inner face and freely moving. SOLUTION: Viscous fluid 4 is received in the vessel 12 of a fluid vibration damping device 3, and the oscillating frequency of the viscous fluid 4 is nearly conformed to the primary natural frequency of a pole 1. Hereby, by oscillating the oscillating mass equivalent of the viscous fluid 4 against earthquake vibration in the same period as the vibration period of the pole 1 and in the timing deviated by one quarter period, large vibration suppression is obtained. Meanwhile, this fluid vibration damping device 3 is hangingly supported with hung nonrigid members 5 while keeping clearance 13 against the inner face 7a, from an outside vessel 7, so as to be oscillatably provided. Consequently, when the pole 1 is oscillated in the distinguished vibration period in the vibration mode over secondary of the pole 1, collision with the outside vessel 7 is repeated, and vibration is restrained by collision energy at the time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pole damping device for a pole such as a power distribution pole, a mobile phone receiving / transmitting pole, an outdoor lighting pole, and the like against earthquakes, winds, and the like.

[0002]

2. Description of the Related Art A pole shakes greatly due to an earthquake, wind or traffic vibration, which may cause plastic deformation or fatigue failure of the pole. Conventionally, the prevention measures can be roughly classified into two. (1) A method in which the weight, shape, and rigidity of the pole are changed to prevent resonance between the natural frequency of the pole and various vibrations serving as excitation sources.

(2) A method in which a vibration damping device having a vibration suppressing function is attached to a pole to reduce a resonance phenomenon. However, in the method of changing the natural frequency in (1), specifically, the design must be changed for each installation location of the pole by changing the cross-sectional shape (thickness, diameter, etc.) of the pole. Not practical.

On the other hand, in the case of using the vibration damping device having the vibration suppression of (2), the vibration damping device is, as in the first conventional example shown in FIG.
A weight body such as a metal ball 101 is provided inside the pole 100 to convert vibration energy when the pole 100 swings in the X-Y direction into collision energy of a plurality of weight bodies and absorb the energy. Conventional example (for example,
No. 6835), water 10
3. Container 102 containing silicon oil, sand, granular iron, etc.
Are provided to absorb vibration. 104 is an attachment part.

[0005]

However, the above (2)
In the former case, since the vibration is absorbed by the collision energy of the metal ball 100 or the like, the number of collisions is large for vibrations in which higher-order vibration modes such as wind are dominant, and the collision energy required for vibration absorption is large. Although it is possible to reduce vibration, it is confirmed that many collisions cannot be expected with relatively small vibration such as seismic motion, and the effect of minimizing large vibration cannot be expected. ing.

In the latter case, damping is added mainly for the purpose of reducing vibrations caused by Karman vortices generated in strong winds. Therefore, the first order of the pole 100 caused by an irregular and large amplitude input such as a seismic motion. The effect of the vibration mode minimizing the outstanding large shaking cannot be expected. Therefore, an object of the present invention is to provide a pole damping device capable of obtaining a large vibration suppression for a seismic motion and obtaining a vibration damping effect even for a shaking in a secondary vibration mode or more. That is.

[0007]

According to a first aspect of the present invention, there is provided a damping device for a pole, comprising a container containing a viscous fluid, wherein the viscous fluid has a swing frequency substantially coincident with the primary natural frequency of the pole. A flow damper, and an outer container provided with a clearance between the container and an inner surface and movably accommodated in the container so as to collide with the inner surface.

According to the first aspect of the present invention, the ground vibration is mainly absorbed by the vibration of the viscous fluid, and the wind vibration and the traffic vibration are mainly caused by the collision of the flow damper with the outer container. Absorb vibration. Therefore, with respect to the pole vibration caused by various inputs such as ground vibration, wind, and traffic vibration, the vibration resistance of the pole is improved by reducing the vibration.
Also, the vibration damping effect can be exhibited without being limited to the swing direction of the pole. Furthermore, it has excellent long-term durability and weather resistance and exhibits stable performance over a long period, so that periodic maintenance is unnecessary.

According to a second aspect of the present invention, in the pole damper according to the first aspect, the flow damper is swingably attached to the outer container. According to the pole damping device of the second aspect, the same effect as that of the first aspect is obtained. According to a third aspect of the present invention, in the pole damper according to the second aspect, the flow damper is suspended from a top surface in the outer container by a non-rigid member.

According to the third aspect of the present invention, the same effects as those of the first aspect are obtained. According to a fourth aspect of the present invention, in the pole damping device according to the second aspect, the flow damper has a joint having a substantially hemispherical concave or convex surface formed on a lower surface thereof, and has a substantially hemispherical shape. A pedestal having a convex or concave surface for receiving a concave or convex surface is provided in the outer container.

According to the fourth aspect of the invention, the same effects as those of the first aspect are obtained. According to a fifth aspect of the present invention, in the pole damping device according to the first aspect, the flow damper is installed on a bottom surface of the outer container so as to be movable in a horizontal plane. According to the pole damping device of the fifth aspect, the same effect as that of the first aspect is obtained. According to a sixth aspect of the present invention, in the pole damper according to the fifth aspect, the flow damper is mounted on a bottom surface of the outer container via a bearing.

According to the sixth aspect of the present invention, the same effects as those of the first aspect are obtained. The pole vibration damping device according to claim 7, further comprising: a flow damper having a container containing a viscous fluid, wherein the viscous fluid has a swing frequency substantially equal to a primary natural frequency of the pole; An outer container movably housed therein, and a weight suspended below the container via a rigid connecting rod so as to be able to collide with the inside of the pole.

According to the seventh aspect of the present invention, in addition to the same effects as those of the first aspect, the weight collides with the pole at the position where the amplitude becomes the largest, so that particularly the wind and traffic vibrations are reduced. High vibration suppression effect.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, the pole damping device 2 includes the flow damping device 3 and the outer container 7. The flow system vibration device 3 has a container 12 containing a viscous fluid 4, and the viscous fluid 4 has a swing frequency substantially matching the primary natural frequency of the pole 1. In the embodiment, the flow damper 3 is a device in which a liquid is put as a viscous fluid 4 in a cylindrical container 12.

The outer container 7 has a clearance 13 provided between the container 12 and the inner surface 7a, and accommodates the container 12 movably so as to collide with the inner surface 7a. In the embodiment, a horizontal arm 9 is attached to the upper end of an outdoor lighting pole 1 installed on a base 8 such as the ground, and a lamp 10 is attached to the tip of the arm 9.
And an outer container 7 is attached to the upper end of the pole 1. Also, the outer container 7 is movably accommodated by swingably mounting the flow damper 3, so that the container 12 is suspended from the top surface of the outer container 7 by the non-rigid member 5 which is a suspending member. Next, this pole damping device 2
The operation of will be described. Since the viscous fluid 4 is stored in the container 12 of the flow system vibration device 3, and the oscillation frequency of the viscous fluid 4 is substantially equal to the primary natural frequency of the pole 1, the primary natural vibration of the pole 1 is Oscillation of the oscillating mass (based on the Hausner theory) of the viscous fluid 4 at the same period as the oscillation period of the pole 1 and a phase shift of a quarter period with respect to the predominant number of earthquake motions Thereby, large vibration suppression can be obtained. On the other hand, the flow damping device 3 is suspended and supported by the non-rigid member 5 suspended by the outer container 7 while keeping the inner surface 7a and the clearance 13 therebetween, and constitutes a suspended structure 6 having the flow damping device 3 as a mass point. It is arranged to swing freely. Therefore,
When the secondary or higher vibration mode of the pole 1 such as wind, traffic vibration, and the like, the pole 1 shakes at a remarkable vibration cycle,
The suspended structure 6 also vibrates similarly, and the collision with the outer container 7 is repeated. Vibration suppression can be obtained by the collision energy at this time. In addition, according to this operation, in the case where the primary natural frequency of the pole 1 in which the viscous fluid 4 accommodated in the flow damper 3 fluctuates is a remarkable vibration, in addition to the vibration suppression effect of the flow damper 3 alone, Further, since the effect of the collision energy is also added, greater vibration suppression can be obtained.

In this embodiment, the flow structure vibration device 3
Is shown suspended by four non-rigid members 5, but any number may be used as long as the suspended state of the flow damper 3 can be stabilized. According to this embodiment, the vibration resistance of the pole 1 is improved by reducing the vibration of the pole 1 caused by various inputs such as ground vibration, wind, and traffic vibration. The vibration damping effect can be exhibited without being limited to the swing direction of the pole 1. It has excellent long-term durability and weather resistance and exhibits stable performance over a long period of time, so regular maintenance is unnecessary.

FIG. 4 shows a second embodiment of the present invention. That is, in the first embodiment, the pole 1 has a square cross section, and the container 1 of the flow damper 3 is adjusted accordingly.
2 is formed in a rectangular cylindrical shape, and the outer container 7 is also formed in a rectangular cylindrical shape. The flow system vibration device 3 containing the viscous fluid 4 is a pole 1
According to Hausner's theory, the larger the inner dimension of the shape of the container 12, the lower the oscillation frequency, and as a result, as in the case of the pole 1 having a square cross section, depending on the vibration direction. Even when the natural frequency is different and the natural frequency is smaller in the 45 ° direction than in the XY direction, the vibration suppression effect can be obtained.

The other points are the same as in the first embodiment. FIG. 5 shows a third embodiment of the present invention. That is, in the first embodiment, the flow damper 3 has a joint 15 having a substantially hemispherical convex surface on the lower surface,
A base 16 having a substantially hemispherical concave surface that receives the convex surface of the joint 15 is provided on the bottom surface of the outer container 7.

Since the viscous fluid 4 is stored in the flow vibration device 3 and the oscillation frequency of the viscous fluid 3 is substantially equal to the primary natural frequency of the pole 1, the primary natural vibration of the pole 1 is Oscillating mass equivalent to vibrating fluid 4 (based on Hausner theory) at the same period as the oscillation period of pole 1 and at a timing shifted by a quarter period with respect to the predominant number of earthquake motions Thereby, large vibration suppression can be obtained. On the other hand, the flow damper 3 has a joint 15 having a hemispherical convex surface at the bottom and an outer container 7.
And a pedestal 16 having a hemispherical concave surface provided on the bottom surface of
The structure 6 is mounted so as to be swingable with an inner surface 7 a of the outer container 7 and a clearance 13. Therefore, when the pole 1 sways at a predominant vibration cycle of secondary or higher vibration modes of the pole 1 such as wind and traffic vibration,
The structure 6 also oscillates, and the collision with the outer container 7 is repeated. Vibration suppression can be obtained by the collision energy at this time. Further, according to this action, when the primary natural frequency of the pole 1 such that the viscous fluid 4 accommodated in the flow damper 3 oscillates is excellent, the flow damper 3
Since the effect due to the collision energy is added in addition to the independent vibration suppression effect, a larger vibration suppression can be obtained together.

The other points are the same as in the first embodiment. In this embodiment, the form of the pole 1 having a round cross section is shown, and the container 12 of the flow damper 3 is also cylindrical.
Needless to say, the container 12 and the outer container 7 for the pole 1 having a square cross section as in the second embodiment may have a container shape substantially similar to the cross-sectional shape.

A hemispherical convex surface may be formed on the base 16 side, and a hemispherical concave surface may be formed on the joint 15. FIG. 6 shows a fourth embodiment of the present invention. That is, in the first embodiment, the flow damper 3 is installed on the bottom surface of the outer container 12 so as to be movable in a horizontal plane. In the embodiment, the flow damper 3 includes a plurality of bearings 17. It is placed on the bottom surface of the outer container 7 through the middle.

The viscous fluid 4 is housed in the flow damper 3, and the oscillation frequency of the viscous fluid 3 is substantially equal to the primary natural frequency of the pole 1. Oscillating mass equivalent to vibrating fluid 4 (based on Hausner theory) at the same period as the oscillation period of pole 1 and at a timing shifted by a quarter period with respect to the predominant number of earthquake motions Thereby, large vibration suppression can be obtained. On the other hand, the flow damper 3 is provided with a structure 6 movably mounted in a horizontal plane with a clearance 13 and an inner surface 7a of the outer container 7 via a bearing 17 disposed on the bottom surface of the outer container 7. Make up. Therefore, when the pole 1 sways at a predominant vibration cycle of the secondary or higher vibration mode of the pole 1 such as wind and traffic vibration, the structure 6 also oscillates and the collision with the outer container 7 is repeated. . Vibration suppression can be obtained by the collision energy at this time. In addition, according to this function, in the case where the primary natural frequency of the pole 1 in which the viscous fluid 4 housed in the flow damper 3 fluctuates is a remarkable vibration, in addition to the vibration suppression effect of the flow damper 3 alone, Further, since the effect of the collision energy is also added, greater vibration suppression can be obtained.

In this embodiment, the form of the pole 1 having a round cross section is shown, and the vessel 12 of the flow damper 3 is also cylindrical. However, as in the second embodiment, the pole 1 having a square cross section is used. On the other hand, it goes without saying that the container 12 and the outer container 7 may have container shapes substantially similar to their cross-sectional shapes. Others are the same as in the first embodiment.

FIG. 7 shows a fifth embodiment of the present invention. That is, in the third embodiment, the flow damper 3 suspends the weight 19 below the container 12 via the rigid connecting rod 11, and these are positioned in the pole 1. Since the viscous fluid 4 is housed in the flow system vibration device 3 and the oscillation frequency of the viscous fluid 3 is substantially equal to the primary natural frequency of the pole 1, the primary natural frequency of the pole 1 is predominant. The vibration mass equivalent to the vibrating fluid 4 (based on the Hausner theory) fluctuates at a timing that is the same as the vibration period of the pole 1 and is out of phase by a quarter period in response to the seismic motion. Vibration suppression can be obtained. On the other hand, the flow damper 3 has a connecting rod 11 rigidly connected to a hemispherical convex joint 15 provided on the bottom surface of the outer container 7 and a weight 19 attached to the tip thereof.
The structure 6 is configured to be swingably mounted with a clearance 13 and an inner surface 7a of the outer container 7 on a pedestal 16 having a hemispherical concave surface provided on the bottom surface of the outer container 7. . Therefore, when the pole 1 sways at a predominant vibration cycle of the secondary or higher vibration mode of the pole 1 such as wind or traffic vibration, the structure 6 also oscillates and the weight 19 via the connecting rod 11. And the inside of the pole 1 is repeated. The collision energy at this time is 2
The next or higher vibration mode acts at the position where the amplitude becomes the largest in the outstanding vibration, so it is reasonable to suppress the vibration.

The other points are the same as in the third embodiment.
In this embodiment, the form of the pole 1 having a round cross section is shown, and the container 12 of the flow damper 3 is also cylindrical.
Needless to say, the container 12 and the outer container 7 for the pole 1 having a square cross section as in the embodiment described above may have a container shape substantially similar to the cross sectional shape.

Although the connecting rod 11 and the weight 19 are provided in the third embodiment, they may be provided in other first embodiments and the like. Further, in the fifth embodiment, the weight 19 collides with the pole 1.
2 may not collide with the inner surface 7a of the outer container 7 or may collide with the inner surface 7a. Further, the weight 19 may not collide with the pole 1 and only the container 12 may collide.

[0027]

According to the first aspect of the present invention, the ground vibration is mainly absorbed by the vibration of the viscous fluid, and the wind and the traffic vibration are mainly absorbed by the collision of the flow damper with the outer container. Absorb vibrations caused by Therefore, with respect to the pole vibration caused by various inputs such as ground vibration, wind, and traffic vibration, the vibration resistance of the pole is improved by reducing the vibration.
Also, the vibration damping effect can be exhibited without being limited to the swing direction of the pole. Furthermore, it has excellent long-term durability and weather resistance and exhibits stable performance over a long period, so that periodic maintenance is unnecessary.

According to the pole damping device of the second aspect, the same effect as that of the first aspect is obtained. According to the pole damping device of the third aspect, the same effect as that of the first aspect is obtained.
According to the pole damping device of the fourth aspect, the same effect as that of the first aspect is obtained. According to the pole damping device of the fifth aspect, the same effect as that of the first aspect is obtained. According to the pole damping device of the sixth aspect, the same effect as that of the first aspect is obtained.

According to the pole damping device of the seventh aspect, in addition to the same effects as those of the first aspect, the weight collides with the pole at the position where the amplitude becomes the largest, so that particularly the wind and traffic vibrations are reduced. High vibration suppression effect.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a first embodiment of the present invention.

FIG. 2 is a partially enlarged side view thereof.

FIG. 3 is a plan view of FIG. 1;

FIGS. 4A and 4B show a second embodiment, wherein FIG. 4A is a schematic partial cross-sectional side view, FIG. 4B is a plan view, and FIG.

FIGS. 5A and 5B show a third embodiment, wherein FIG. 5A is a schematic partial cross-sectional side view, FIG. 5B is a plan view, and FIG.

6A and 6B show a fourth embodiment, in which FIG. 6A is a schematic partial cross-sectional side view, FIG. 6B is a plan view, and FIG.

FIGS. 7A and 7B show a fifth embodiment, wherein FIG. 7A is a schematic partial cross-sectional side view, FIG. 7B is a plan view, and FIG.

FIG. 8 is an explanatory diagram illustrating a collision of a metal ball of the first conventional example.

9A and 9B are explanatory views of a second conventional example, in which FIG. 9A is a partial side view of a pole, FIG. 9B is a cross-sectional view thereof, and FIG. 9C is a cross-sectional view of a container.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pole 2 Pole damping device 3 Flow damping device 4 Viscous fluid 5 Non-rigid member 7 Outer container 7a Inner surface 11 Connecting rod 12 Container 13 Clearance 15 Joint 16 Base 17 Bearing 19 Weight

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Fumihiro Komatsubara 1048 Kazumasa Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd.

Claims (7)

[Claims] 1. A vibration damping device having a container containing a viscous fluid, the viscous fluid having a swing frequency substantially matching the primary natural frequency of a pole, and a clearance between the container and an inner surface. And an outer container which is provided so as to be movable so as to be able to collide with the outer container. 2. The pole vibration damping device according to claim 1, wherein the flow damping device is swingably attached to the outer container. 3. The damping device for a pole according to claim 2, wherein the flow damping device is suspended from a top surface in the outer container by a non-rigid member. 4. The flow damping device has a joint having a substantially hemispherical concave or convex surface formed on a lower surface thereof, and a base having a substantially hemispherical surface and having a convex or concave surface receiving the concave or convex surface. The pole damping device according to claim 2, wherein the pole damping device is provided in the outer container. 5. The damping device for a pole according to claim 1, wherein the flow damper is movably installed on a bottom surface of the outer container in a horizontal plane. 6. The pole vibration damping device according to claim 5, wherein said flow damping device is mounted on a bottom surface of said outer container via a bearing. 7. A flow damper having a container containing a viscous fluid, wherein the viscous fluid has a swing frequency substantially equal to a primary natural frequency of a pole, and an outer container movably housing the container. And a weight suspended below the container so as to collide with the pole via a rigid connecting rod.