JP3923888B2 - Pole structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pole structure provided with a dynamic vibration absorber for reducing vibrations of a pole body that is provided alongside a road, a railroad, or the like, or is installed in a building, a site, or a mechanical structure.
[0002]
[Prior art]
For example, in poles such as lighting poles, signal poles, power transmission towers attached to roads, railways, etc., resonance phenomena were caused by wind, earthquake, or vibration caused by vehicle traffic, and they were shaken and attached to the poles. Damage to lighting, signal lines, or poles may occur. In order to prevent such resonance of the pole, there is a structure in which a physical pendulum is provided inside the pole body, and the vibration of the pole is reduced by the vibration of the physical pendulum (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-59543
[Problems to be solved by the invention]
However, in the case where a physical pendulum is provided inside the pole, a mechanism such as an oil damper is complicated and requires maintenance. In addition, since it is necessary to previously incorporate a physical pendulum into the pole when the pole is manufactured, it is difficult to apply it to an existing pole that does not employ measures for reducing vibration.
[0005]
An object of the present invention is to provide a pole structure including a dynamic vibration absorber that can be easily attached with a simple structure.
[0006]
[Means for Solving the Problems]
The pole structure of the present invention includes a pole body, a spring member having a high damping capacity of 1% or more in damping ratio, an anisotropic cross-sectional shape thereof, a weight attached to one end portion of the spring member , A dynamic vibration absorber comprising a support member for attaching the other end of the spring member to the pole body, and the two natural modes in which the resonance frequency of the dynamic vibration absorber is substantially orthogonal within the cross section of the spring member. It is characterized by being different .
[0007]
Further, the natural vibration frequency of the dynamic vibration absorber is adjusted by fixing the connection position between the weight and the spring member and adjusting the rotational inertia of the weight .
[0008]
And a dynamic vibration absorber comprising a pole body, a spring member, a weight attached to one end portion of the spring member, and a support member attaching the other end portion of the spring member to the pole body, A plurality of the dynamic vibration absorbers are arranged so that weights are positioned in an annular shape, and adjacent weights arranged in an annular shape are joined by a member that is more flexible than the spring member .
[0009]
And a dynamic vibration absorber comprising a pole body, a spring member, a weight attached to one end of the spring member, and a support member attaching the other end of the spring member to the pole body, A plurality of the dynamic vibration absorbers are arranged so that the weights are located in an annular shape, and adjacent weights arranged in an annular shape are connected by a viscoelastic body, and a spring member attached to each weight is around the pole body. Are attached to one or more support members attached to the pole body .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. FIG. 1 is an explanatory view of a pole structure according to a first embodiment of the present invention, FIG. 1 (a) is a plan view, FIG. 1 (b) is a side view, and FIG. It is explanatory drawing of a vibration direction and natural frequency . In FIG. 1, two dynamic vibration absorbers 11 are attached to a pole body 12. The dynamic vibration absorber 11 is configured by attaching a weight 14 to one end of a spring member 13 with an adjusting tool 15. The other end of the spring member 13 is attached to the pole body by the support member 16. As the spring member 13, a spring member having a damping ratio of 1% or more is used. For example, a manganese copper (Mn—Cu) based alloy is used. In the present invention, a spring member having a damping ratio of 1% or more is referred to as a spring member having a high damping capacity.
[0011]
In the first embodiment, the spring member 13 of the dynamic vibration absorber 11 has a rectangular cross-sectional shape . The support member 16 includes a plate 16a and a support 16b, and is provided in common for the two dynamic vibration absorbers 11. The support member 16b grips the outside of the pole body 12 so that the two dynamic vibration absorbers 11 are provided. It is attached with the attached plate 16a and bolts and nuts. The adjusting tool 15 is for adjusting the mounting position of the weight 14, and the adjusting position is changed by the adjusting tool 15 to adjust the natural frequency of the dynamic vibration absorber 11 by adjusting the distance between the plate 16a and the weight 14. I can do it. Even if the adjustment tool 15 is provided on the plate 16a and the length of the spring member 13 is adjusted, the natural frequency can be similarly adjusted. Further, the natural frequency of the dynamic vibration absorber 11 can be adjusted by appropriately selecting the mass of the weight 14 attached to the spring member 13.
[0012]
Further, in the dynamic vibration absorber 11 using the spring member 13 having such a rectangular cross section, as shown in FIG. 1C, two different natural frequencies in two different directions (directions orthogonal to each other). It can have f1 and f2. In this case, the natural frequencies f1 and f2 vary depending on the relationship between the horizontal side a and the vertical side b of the rectangle. The relationship of f1 ≧ f2 holds when a ≧ b, and f1 ≦ f2 holds when a ≦ b. Therefore, by appropriately selecting the sizes of the horizontal side a and the vertical side b, one dynamic vibration absorber 11 can have two natural frequencies. By adjusting the spring constant of the spring member 13 in these two directions, the natural frequency can be changed so that the dynamic vibration absorber is tuned to the two vibration modes of the pole. In the above description, the case where two dynamic vibration absorbers 11 are attached to the pole body 12 has been described. However, one dynamic vibration absorber 11 may be attached to the pole body 12, or three or more dynamic vibration absorbers may be attached. The vessel 11 may be attached to the pole body 12.
[0013]
According to the first embodiment, since one dynamic vibration absorber 11 can have two natural frequencies, one dynamic vibration absorber 11 can be provided with respect to two directions of the pole body 12 that is a vibration control target. The dynamic vibration absorber 11 can serve as a double dynamic vibration absorber that suppresses vibration when vibrating at different natural frequencies f1 and f2. In the above description, the case where the cross-sectional shape of the spring member 13 is rectangular has been described. However, the cross-sectional shape having any n sides may be an anisotropy n-polygon (polygon), or an elliptical shape. It is also good. Further, the cross-sectional shape of the spring member may be a cross-sectional shape having various anisotropies such as an H-shape and a concave-shape so that the torsional vibration is effective at the same time as the translation direction.
[0014]
In the dynamic vibration absorber 11 having such a basic structure, when the two weights 14a and 14b are held by the adjusting tool 15 with the spring member 13 interposed therebetween as shown in FIG. 2A, the rotational inertia of the weight is adjusted. The natural frequency of the dynamic vibration absorber can be adjusted. When the rotational inertia of the weights 14a and 14b is adjusted to the lower side to increase the natural frequency, the two weights 14a and 14b are moved upward (on the support member 16 as shown in FIG. 2B). When the rotation inertia is adjusted to a low side and the natural frequency is lowered, the two weights 14a and 14b are used as shown in FIG. Is rotated downward (in a direction approaching the support position of the support member 16).
[0015]
Now, assuming that the pole body 12 starts to vibrate due to wind or traffic vibration, the vibration is transmitted from the panel 16a of the support member 16 to the weight 14 via the spring member 12. The vibration of the pole body 12 is transmitted to the weight 14 in all vibration directions in the horizontal plane of the pole body 12. Not only the vibration in the translation direction but also the torsional vibration in the circumferential direction of the pole body 12 is transmitted to the weight 14 via the spring member 12. Therefore, if the arrangement of the spring member, the spring length, and the cross-sectional shape of the spring are determined so as to synchronize with the eigenmode of the pole body in each vibration direction, a single vibration damping device can be used in a plurality of vibration directions of the pole body 12. On the other hand, the vibration of the pole body 12 can be suppressed. In the above description, the case where two dynamic vibration absorbers 11 are attached to the pole body 12 has been described. However, one dynamic vibration absorber 11 may be attached to the pole body 12, or three or more dynamic vibration absorbers may be attached. The vessel 11 may be attached to the pole body 12.
[0016]
According to the first embodiment, since the spring member 13 having a high damping capacity serves as both the spring element and the damper element of the dynamic vibration absorber 11, the number of constituent members can be reduced and a simple structure can be achieved. Therefore, the support member 16 can also be configured simply and can be easily attached to the pole body 12. Further, the vibration of the pole body 12 can be suppressed with respect to a plurality of vibration directions of the pole body 12, for example, the translational direction and the twisting direction. Further, the natural frequency of the dynamic vibration absorber 11 can be changed by appropriately selecting the mass of the weight 14 attached to the spring member 13 or adjusting the attachment position and the rotational inertia of the weight 14 with the adjusting tool 15. Therefore, it can be applied to the pole body 12 having various dimensions. Further, since the dynamic vibration absorber 11 can be easily attached to and detached from the pole body 12 by the support member 16, it can be easily applied to the existing pole body 12.
[0017]
Further, the spring member 13 may be made of, for example, Mn− as a damping material having a high damping capacity.
Cu-based alloy, Mg alloy, high damping capacity cast iron, Ni-Ti alloy, Fe-Mn alloy, Zn-Al alloy, damping steel plate, nylon 6, PBT, PE and other materials exhibiting damping capacity of 1% or more Is used.
[0018]
In general, since structures are designed with a damping ratio of 1% or less, a significant vibration suppressing effect can be expected by setting the damping ratio of the dynamic vibration absorber to 1% or more. In particular, the pole is a structure having a slightly small attenuation ratio, so that the effect is great. Further, when the attenuation ratio of the pole is extremely small, the effect may be obtained even if the attenuation of the dynamic vibration absorber is 1% or less.
[0019]
FIG. 3 is an explanatory diagram in which the dynamic vibration absorber 11 shown in FIG. 1 is applied to a streetlight as an example of the pole structure according to the first embodiment of the present invention . In FIG. 3 , one or a plurality of the dynamic vibration absorbers 11 shown in FIG. 1 are attached to the outside of the column portion 12a of the pole body 12 or the outside of the arm portion 12b of the pole body 12.
[0020]
According to FIG. 3 , when the pole body 12 resonates due to wind, traffic vibration, or the like, vibration can be appropriately suppressed with respect to horizontal and vertical vibrations. Moreover, since the dynamic vibration absorber 11 can be attached to the outside of the pole, it can be easily attached and detached, and can be easily attached to an existing road light to perform vibration control. Moreover, since the dynamic vibration absorber 11 is covered and protected by the protective cover 17, deterioration can be prevented.
[0021]
Next, a second embodiment of the present invention will be described. FIG. 4 is an explanatory view of a pole structure according to the second embodiment of the present invention, FIG. 4 (a) is a side view of the pole body 12 attached to the pole body 12, and FIG. 4 (b) is FIG. 4) is a partially cutaway vertical sectional view of a C portion, and FIG. 4C is a horizontal sectional view of the C portion of FIG. In this second embodiment, weights 14 of a plurality of dynamic vibration absorbers 11 are arranged in an annular shape, and adjacent weights 14 arranged in an annular shape are coupled by a viscoelastic body 18. The attached spring members 13 are each attached to one support member 16 that surrounds the periphery of the pole body 12 and is disposed above the weight 14, thereby constituting a pole structure.
[0022]
As shown in FIG.4 (c) , the weight 14 of the four dynamic vibration absorbers 11 is formed in circular arc shape, and is arrange | positioned at annular | circular shape. Then, adjacent arc-shaped weights 14 arranged in an annular shape are coupled by a viscoelastic body 18. One end of the spring member 13 is attached to substantially the center of each of the weights 14 formed in an arc shape, and the other end of each spring member 13 is inclined upward as shown in FIG. Attached to the common support member 16. One support member 16 is attached so as to surround the support 12 a of the pole body 12. As the viscoelastic body 18, for example, a material such as resin or rubber is used.
[0023]
Here, since the arcuate weight 14 is suspended by the spring member 13, the arcuate weight 14 may fall off when the spring member 13 is damaged. It may be arranged side by side. In this case, the drop-off preventing member is attached so as not to affect the function of the spring member 13. For example, a fiber member, a chain, etc. are slackened and the circular weight 14 is suspended. Similarly, a detachment preventing member for preventing the detachment of the viscoelastic body 18 provided between the adjacent arcuate weights 14 arranged in an annular shape may be provided. For example, the arc-shaped weight 14 and the viscoelastic body 18 are covered with a resin, and a cover or a film is integrally wound thereon to form a cover. Also in this case, the function of the viscoelastic body 18 is not affected. Further, a plurality of dynamic vibration absorbers 11 may be covered and protected by the protective cover 17.
[0024]
According to the second embodiment, when the pole body 12 resonates due to some external force, the dynamic vibration absorber in each vibration direction vibrates even when the vibration vibrates in any direction within the horizontal plane. By virtue of the above, or when the plurality of dynamic vibration absorbers vibrate in cooperation, the vibration of the plurality of vibration modes of the pole body 12 can be suppressed. Further, since the four weights 14 are connected in an annular shape by the viscoelastic body 18, when the weights vibrate separately, the damping corresponding to the relative speed between the weights occurs, so that the vibration damping is performed. The effect is increased. When the viscoelastic body 18 does not require a damping function, a soft material having a low damping capacity may be used. In the above description, the pole structure is configured by the four dynamic vibration absorbers 11. However, any number of the dynamic vibration absorbers 11 may be used.
[0025]
Next, a third embodiment of the present invention will be described. FIG. 5 is an explanatory view of a pole structure according to a third embodiment of the present invention. FIG. 5 (a) is a side view of the pole body 12 attached to the pole body 12, and FIG. ) Is a partially cutaway vertical sectional view of a D portion, and FIG. 5C is a horizontal sectional view of the D portion of FIG. In this third embodiment, weights 14 of a plurality of dynamic vibration absorbers 11 are arranged in an annular shape, adjacent weights 14 arranged in an annular shape are connected by viscoelastic bodies 18, and each weight 14 is connected to each weight 14. The attached spring members 13 are attached to two support members 16 which surround the pole body 12 and are arranged above and below the weight 14, respectively.
[0026]
As shown in FIG. 5C , the eight weights 14 are formed in a clip shape and sandwich one end of the two spring members 13 in common. The clip-shaped weights 14 are arranged in an annular shape, and the adjacent clip-shaped weights 14 arranged in an annular shape are connected by a viscoelastic body 18. Then, as shown in FIG. 5B , the other end of each spring member 13 is inclined upward and downward and attached to two common support members 16. The two support members 16 are attached so as to surround the support 12 a of the pole body 12.
[0027]
In the above description, the case where eight weights 14 are used is shown, but any number of weights 14 may be used. Further, similarly to the second embodiment, a drop-off prevention member may be provided along with the spring member 13, or a removal prevention member for preventing the viscoelastic body 18 from being detached may be provided. good. Further, a plurality of dynamic vibration absorbers 11 may be covered and protected by the protective cover 17.
[0028]
According to the third embodiment, when the pole body 12 is resonated by some external force, the dynamic vibration absorption is in the vibration direction regardless of the direction in which the column 12a of the pole body 12 vibrates in the horizontal plane. The vibration absorber 11 or the plurality of dynamic vibration absorbers 11 vibrate in cooperation. Therefore, the vibration of the plurality of vibration modes of the pole body 12 can be suppressed. Since the spring member 13 of the dynamic vibration absorber 11 is supported by the upper and lower support members 16, the dynamic vibration absorber 11 is effectively prevented from falling.
[0029]
Next, a fourth embodiment of the present invention will be described. 6A and 6B are explanatory views of a pole structure according to the fourth embodiment of the present invention. FIG. 6A is a side view of the pole body 12 attached to the pole body 12, and FIG. FIG. 6C is a horizontal sectional view of the E portion of FIG. 6A. In the third embodiment, a spherical weight 14 is used in place of the arc-shaped weight 14 and the number thereof is n, compared to the second embodiment shown in FIG. The same elements as those of the second embodiment shown in FIG.
[0030]
As shown in FIG. 6C , the n weights 14 are formed in a spherical shape and are arranged in an annular shape. Then, adjacent arc-shaped weights 14 arranged in an annular shape are coupled by a viscoelastic body 18. One end of each spring member 13 is attached to each weight 14 formed in a spherical shape, and the other end of each spring member 13 is inclined upward as shown in FIG. It is attached to the member 16. One support member 16 is attached so as to surround the support 12 a of the pole body 12.
[0031]
Also in the case of the fourth embodiment, as in the second embodiment, a drop-off prevention member may be provided along with the spring member 13, and the detachment for preventing the viscoelastic body 18 from detaching. A prevention member may be provided. Further, a plurality of dynamic vibration absorbers 11 may be covered and protected by the protective cover 17.
[0032]
According to the fourth embodiment, even when resonance occurs in the pole body 12 due to some external force and the column portion 12a of the pole body 12 vibrates in an arbitrary direction in the horizontal plane, the dynamic vibration absorber 11 is in the vibration direction. Or the vibration of the several vibration mode of the pole main body 12 can be suppressed because the some dynamic vibration absorber 11 vibrates in cooperation. Further, the n weights 14 can vibrate the n dynamic vibration absorbers 11 in the circumferential direction even when torsional vibration occurs in the pole body 12. Therefore, it also has a damping effect against torsional vibration.
[0033]
The pole structure of the present invention is a pole attached to a road or a railway, for example, a structure such as a support pole or a power pole such as an illumination lamp, a signal lightning display panel, a sign, a camera, a speed measuring device, etc. This also applies to the pole structure. For example, the present invention can be applied to a pole-shaped antenna such as a mobile phone relay antenna installed on a rooftop of a building or an antenna in a radio station site.
[0034]
【The invention's effect】
As described above, according to the present invention, the structure is simple, the adjustment of the natural frequency of the dynamic vibration absorber is easy, and the vibration suppression effect is provided for a plurality of vibration modes and arbitrary vibration directions. It is possible to provide a pole structure having a dynamic vibration absorber that can be easily installed even for various types of existing poles.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a pole structure according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram for adjusting the rotational inertia of the dynamic vibration absorber according to the first embodiment of the present invention.
FIG. 3 is an explanatory diagram when the dynamic vibration absorber according to the first embodiment of the present invention is applied to a streetlight .
FIG. 4 is an explanatory diagram of a pole structure according to a second embodiment of the present invention.
FIG. 5 is an explanatory diagram of a pole structure according to a third embodiment of the present invention.
FIG. 6 is an explanatory diagram of a pole structure according to a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Dynamic vibration absorber, 12 ... Pole main body, 12a ... Support | pillar part, 12b ... Arm part, 13 ... Spring member, 14 ... Weight, 15 ... Adjustment tool, 16 ... Support member, 17 ... Protective cover,
18 ... Viscoelastic body

Claims (4)

Wherein the pawl body, the other end of the cross-sectional shape having at least 1% of a high damping capacity is a spring member having anisotropy in damping ratio and weight attached to one end of the spring member and the spring member And a dynamic vibration absorber having a support member attached to the pole body , wherein the resonance frequency of the dynamic vibration absorber is different in two eigenmodes substantially orthogonal within the cross section of the spring member. object. The pole structure according to claim 1 , wherein the natural frequency of the dynamic vibration absorber is adjusted by fixing a connection position between the weight and the spring member and adjusting a rotational inertia of the weight . A dynamic vibration absorber comprising a pole body, a spring member, a weight attached to one end portion of the spring member, and a support member attaching the other end portion of the spring member to the pole body, and the weight A pole structure characterized in that a plurality of the dynamic vibration absorbers are arranged so as to be positioned in an annular shape, and adjacent weights arranged in an annular shape are joined by a member softer than the spring member . A dynamic vibration absorber comprising a pole body, a spring member, a weight attached to one end portion of the spring member, and a support member attaching the other end portion of the spring member to the pole body, and the weight A plurality of the dynamic vibration absorbers are arranged so as to be positioned in an annular shape, and adjacent weights arranged in an annular shape are connected by a viscoelastic body, and a spring member attached to each weight surrounds the periphery of the pole body A pole structure attached to one or more support members attached to the pole body .

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