JP5647816B2 - Vibration control device and standing member with excellent vibration control - Google Patents

Description

  The present invention relates to a vibration damping device and a standing member excellent in vibration damping performance. In particular, the present invention relates to a vibration control device used for a standing member such as an illumination column, a sign column, a signal column, and the like standing on a road or a bridge, and a standing member excellent in vibration damping.

  A standing member such as an illumination column, a sign column, or a signal column installed on a road or a bridge may shake due to a resonance phenomenon caused by a wind, an earthquake, a road surface vibration caused by traveling of a vehicle, or the like. When these standing members swing, the standing members are easily damaged by the swing, and the damage is promoted. In addition, there is a problem that the life of the instrument attached to the standing member is shortened due to the generated vibration. Further, in the case of the illumination column, there is a problem that the illumination light is shaken and the person feels uncomfortable.

In order to prevent the standing member from shaking due to such a resonance phenomenon,
(a) A method of changing the natural frequency by changing the weight, shape and rigidity of the standing member,
(b) A method of providing a physical pendulum and a contact tool inside the standing member and having a vibration damping effect by causing the physical pendulum to collide with the contact tool during vibration,
However, each has already been proposed.

  However, although the method (a) has a damping effect for a specific frequency, it cannot cope with fluctuations in which the excitation cycle and frequency fluctuate variously, such as fluctuations caused by wind. As a result, the degree of freedom in the material design of the standing member is reduced. In addition, in the method (b) above, in addition to not being able to cope with fluctuations in which the excitation cycle and frequency fluctuate variously, in order to increase the vibration damping effect, the physical pendulum and the abutment tool must be larger than a certain size. It is necessary to be safe. For this purpose, a storage space is required, which also reduces the degree of freedom in designing the standing member.

  In Patent Document 1, based on such problems of the prior art, a chain or wire is suspended with a non-fixed free vibration portion inside a vertical hollow body, and the chain or wire and the vertical hollow are suspended. A vibration damping device (hereinafter, referred to as “chain damper”) that responds to fluctuations in the frequency by keeping the distance from the inner wall of the body equivalent is described. When this vibration damping device is attached to the outside or the inside of the vertical erection member, the vibration caused by the vibration applied to the vertical erection member can be attenuated.

Japanese Patent Publication No. 04-26004

  Even when a chain damper is incorporated in standing members such as an illumination column, a sign column, and a signal column, the standing member may be swayed due to a resonance phenomenon caused by wind, earthquake, road surface vibration caused by traveling of the vehicle, or the like. And if these standing members are shaken, the generated vibration shortens the life of the equipment attached to the standing members.Furthermore, in the case of an illumination column, the illumination light is shaken and the person feels uncomfortable. give.

  This is because vibrations caused by wind, earthquakes, road surface vibrations associated with vehicle travel, etc. have a wide frequency range.

  That is, a chain damper that simply suspends a steel chain inside a vertical hollow body cannot cope with vibrations in the entire frequency range. The chain damper has a damping effect for vibrations with a frequency of 6 Hz or more, but it has been found that the damping effect for vibrations with a frequency of 5 Hz or less is insufficient.

  In view of such a situation, the object of the present invention is to provide a damping device that has higher damping performance and is not affected by the direction of vibration, and has excellent damping performance, even in vibrations whose frequency fluctuates over a wide range. It is to provide a standing member.

  As a result of various experiments and examinations, the present inventors have obtained the findings shown in the following (a) to (g).

  (a) A damping device (hereinafter referred to as “granular body”) in which a plurality of granular bodies are accommodated in a container having a curved inner surface at the bottom, and each granular body in the container is movable within the container. "Damper") has a damping effect for vibrations with a low frequency of 1 to 3 Hz, but it has been found that the damping effect for vibrations with a frequency of 4 Hz or more is insufficient.

  For this reason, when further examining what has a damping effect on vibrations with a frequency of 4 Hz or more, instead of accommodating a plurality of granular materials in a container, the flexibility of enclosing a liquid such as water inside When one or a plurality of the bags are movably accommodated in the container, they are used as a vibration damping device (hereinafter referred to as “bag damper”) having an excellent vibration damping effect against vibrations with a frequency of 4 Hz or higher. I found that I can do it. At this time, it was also found that the shape of the container that accommodates the bag formed by enclosing the liquid is not limited to the container having the curved inner surface on the bottom surface, but may be a flat inner surface on the bottom surface. It was also found that this bag damper also has the advantage of exhibiting a smooth damping effect against omnidirectional vibration.

  (b) When this bag damper is attached to a structure such as a standing member, when the structure starts to vibrate, the liquid in the bag not only moves with a phase difference from the vibration of the structure, but also inside. Since the flexible bag body, which is made by enclosing a liquid such as water, is movable within the container, the vibration of the structure is attenuated by colliding with the inner wall of the container, thereby suppressing the vibration of the structure. be able to. That is, the vibration damping effect of the bag damper is due to the energy consumption due to the mass movement of the liquid in the bag, the energy consumption due to the viscous resistance of the liquid in the bag itself, and the frictional resistance at the interface between the liquid in the bag and the bag. It is considered that a plurality of factors are combined, such as energy consumption and energy consumption due to collision of the flexible bag formed by enclosing a liquid such as water with the inner surface of the container.

  (c) The material of the bag body used for the bag body damper is that the liquid sealed in the bag body can move freely without leaking from the bag body, and when the liquid moves in the bag body or When the bag body in which the liquid is enclosed is freely moved in the container, the bag body only needs to be flexible so that the shape of the bag body can be freely changed. A thin film of a high molecular weight material. The liquid to be sealed in the bag can be appropriately selected from water, a highly viscous liquid, a high-density liquid, etc., depending on the vibration frequency to be damped. As the shape of the bag body, for example, a spherical body made of polyethylene may be used, or a cylindrical zip rop may be appropriately heat-sealed into a pillow shape. If a zip-flop is used, the volume of a bag body can be easily made into a desired value.

  (d) The volume ratio of the volume of liquid sealed in the bag to the volume in the bag is not particularly limited. However, as shown in FIG. 5 described later, the attenuation performance varies depending on the capacity ratio. In order to obtain a practically satisfactory attenuation constant, this capacity ratio is preferably 50% or more.

  Moreover, the magnitude | size of the bag body accommodated in a container is not specifically limited, What is necessary is just a magnitude | size which can be accommodated in a container. What is necessary is just to select suitably according to the number of bags. However, when the number of the bags accommodated in the container is increased, the frequency having the damping effect tends to shift to a higher frequency as seen in FIG.

  (e) The shape of the container that movably accommodates the bag body in which the liquid is sealed may be, for example, rectangular or spherical. If the bag body does not jump out of the container due to vibration, the container may not be provided with an upper cover, but a flat or hemispherical upper cover may be provided. When the upper lid is provided on the container, energy is consumed when the bag collides with the upper lid. Therefore, it is preferable to provide the upper lid on the container. In addition, a fluororesin film or an oil film may be stretched on the inner surface of the upper lid of the container so that the bag body in which the liquid is sealed is more easily moved in the container.

  The inner surface of the bottom surface of the container may be semispherical, or may be a rectangular parallelepiped shape in which the inner surface of the bottom surface is flat and has a side wall. When the bag body formed by enclosing the liquid moves in the container and collides with the inner surface of the container, energy is consumed correspondingly. Therefore, a container shape in which the bag body can freely move in the container is preferable. And as a material of a container, it is not specifically limited, For example, iron, stainless steel, and a plastic can be mentioned.

  (f) Not only the bag damper, but also a granular damper may be used in combination to constitute the vibration damping device. In this case, the granular body damper may be vertically stacked under the bag body damper, or may be vertically stacked on the bag body damper. Alternatively, the granular body damper and the bag body damper may be arranged side by side. The bag damper is a vibration damping device that has an excellent vibration damping effect with respect to vibrations having a frequency of 4 Hz or higher, but by combining granular dampers having a vibration damping effect with respect to vibrations with a low frequency of 1 to 3 Hz, This is because it is possible to expect a damping effect for vibrations with a low frequency of 3 Hz.

(g) As described above, the vibration damping device formed by combining the bag damper or the granular damper has higher damping performance against vibrations whose frequency fluctuates over a wide range, and also depends on the vibration direction. Not. Therefore, by attaching to standing members such as lighting pillars, sign pillars, signal pillars, etc. that are erected on roads and bridges, etc., it has higher damping performance against vibrations whose frequency fluctuates over a wide range, and It is possible to impart vibration damping that is not affected by the direction of vibration.

  The vibration damping device and the standing member excellent in vibration damping performance according to the present invention have been completed based on these findings. The gist of the present invention is the following (1) to (5) damping device and (6) standing member having excellent damping performance. Hereinafter, these may be collectively referred to as the present invention.

(1) one or more bag having a variable shape flexibility formed by movably sealed liquid therein, it is movably housed in the interior of the container, the bag body of the container A vibration control device comprising a bag damper that can collide with an inner wall .

(2) one or more of the bag having a variable shape flexibility formed by movably sealed liquid therein, are movably housed in the interior of the container, the bag body of the container A vibration damping device comprising: a bag damper capable of colliding with an inner wall ; and a granular damper in which a plurality of granular substances are movably accommodated in a container having a curved inner surface at the bottom.

  (3) The vibration damping device according to (1) or (2) above, wherein the container has a rectangular parallelepiped shape having a flat bottom surface and a side wall.

  (4) The vibration damping device according to (1) or (2) above, wherein the inner surface of the bottom surface of the container is semispherical.

  (5) The vibration damping device according to any one of (1) to (4) above, wherein the container has an upper lid.

  (6) A standing member comprising the vibration damping device according to any one of (1) to (5) above.

  According to the present invention, it is possible to provide a vibration damping device that has higher damping performance and is not affected by the direction of vibration, and a standing member that is excellent in vibration damping performance, even for vibrations whose frequency fluctuates over a wide range. .

An example (invention example) is shown when a vibration damping device including a bag damper is attached to a column head of a standing member. An example (comparative example) when the damping device which consists of a granular material damper is attached to the column head of a standing member is shown. An example (example of the present invention) is shown when a vibration damping device using a granular body damper and a bag body damper is attached to a column head of a standing member. It is a graph which shows the damping performance about three damping devices which have an upper cover. It is a comparative graph which shows the relationship between a frequency (Hz) and a damping constant (%) when a free vibration experiment is performed with respect to a steel pipe column. The frequency (Hz) and damping constant (%) when changing the volume ratio of water about a bag body damper are plotted. 2 shows another two examples (examples of the present invention) when a vibration damping device including a bag body damper is attached to a column head of a standing member. The frequency (Hz) and damping constant (%) when free vibration experiment was performed with respect to the steel pipe column about two damping devices which do not have an upper cover are plotted.

  Hereinafter, the present invention will be described with reference to the drawings. Here, the damping effect of the present invention was demonstrated using a small experimental device. The present invention is not limited to the following examples.

  Three examples are shown when a vibration damping device having an upper lid is attached to a column head of a standing member.

  FIG. 1 shows an example (example of the present invention) when a vibration damping device comprising a bag damper is attached to a column head of a standing member.

The standing member 2 such as an illuminating column is formed by standing a steel pipe column 4 having a circular cross section on a foundation 3. The vibration damping device including the bag body damper 11 is a container of a rectangular parallelepiped 25 having a flat bottom surface, a side wall, and a flat top lid (the inner surface dimensions are 180.6 mm width × 111 depth. 6 mm × height 25.3 mm) is a bag damper in which one of the flexible bag bodies 23 formed by enclosing a liquid therein is movably accommodated in the container. Here, the bag body 23 formed by enclosing the liquid is a cylindrical zip-flop (volume: 415 cm ³ ) having a width of 160 mm and a depth of 110 mm, and the capacity of 385 g of water is the total volume in the bag body. It is enclosed so as to occupy 93%. The volume of the cylindrical zipp is obtained by heat-sealing using a clip sealer.

  When the steel pipe column 4 constituting the standing member 2 such as an illumination column starts to vibrate, not only the liquid in the bag moves with a phase difference from the vibration of the structure, but also the bag itself collides with the inner wall of the container. Therefore, it is possible to attenuate the vibration of the structure and thereby suppress the vibration of the structure.

  FIG. 2 shows an example (comparative example) when a vibration damping device made of a granular damper is attached to a column head of a standing member.

  The standing member 2 such as an illuminating column is formed by standing a steel pipe column 4 having a circular cross section on a foundation 3. In the vibration damping device comprising the granular damper 12, a plurality of granular bodies 22 move in a container (inner surface size is 197 mm inner diameter × 100 mm height) whose inner and outer surfaces are hemispherical. The upper lid 21 is covered with a planar shape after being accommodated so as to be freely arranged.

  When the steel pipe column 4 constituting the standing member such as the illumination column starts to vibrate, the plurality of granular bodies 22 in the container start to vibrate. Since the plurality of granular bodies 22 are movable in the container, the frictional force between the granular bodies or between the granular bodies and the inner wall of the container, or the plurality of granular bodies vibrate in the opposite phase to the structure. An inertial force is generated, and the vibration of the steel pipe column 4 is damped, thereby suppressing the vibration of the structure.

  FIG. 3 shows an example (example of the present invention) when a vibration damping device using a granular body damper and a bag body damper together is attached to a column head of a standing member.

The standing member 2 such as an illuminating column is formed by standing a steel pipe column 4 having a circular cross section on a foundation 3. Then, a plurality of granular bodies 22 are accommodated in a container (inner surface size is 197 mm inner diameter × 100 mm height) so that the inner and outer surfaces of the bottom surface are hemispherical. A container of a rectangular parallelepiped 25 having a flat top lid, a granule damper 12 having a top lid 21 in shape, and a flat inner surface on the bottom surface and a side wall on the bottom is provided. , Width 180.6 mm × depth 111.6 mm × height 25.3 mm), and one flexible bag body 23 in which a liquid is sealed is accommodated movably in the container. It is a bag damper. Here, the bag body 23 formed by enclosing a liquid is a zip-flop (volume: 415 cm ³ ) having a width of 160 mm and a depth of 110 mm. In this, 385 g of water is 93% of the total volume in the bag body. It is enclosed so as to occupy. The volume of the cylindrical zipprop can be easily set to a desired value by heat-sealing at a desired position using a clip sealer.

  When the steel pipe column 4 constituting the standing member such as the illumination column starts to vibrate, first, the plurality of granular bodies 22 in the container of the granular damper 12 starts to vibrate. Since the plurality of granular bodies 22 are movable in the container, the frictional force between the granular bodies or between the granular bodies and the inner wall of the container, or the plurality of granular bodies vibrate in the opposite phase to the structure. An inertial force is generated, and the vibration of the steel pipe column 4 is damped, thereby suppressing the vibration of the structure. Furthermore, not only the liquid in the bag moves with a phase difference from the vibration of the structure, but also the bag itself collides with the inner wall of the container, so that the vibration of the structure is damped, thereby suppressing the vibration of the structure. Can do.

  FIG. 4 is a comparative graph showing the relationship between the frequency (Hz) and the damping constant (%) when a free vibration experiment is performed on a steel pipe column to which the above three damping devices having an upper lid are attached. It is.

  It can be seen that the bag body damper (example of the present invention) has a remarkable damping effect against vibrations in a wide range of frequencies (4 to 9 Hz). It can be seen that the granular damper (comparative example) only has a damping effect on vibrations in a narrow range (1 to 3 Hz). And it turns out that the vibration damping effect which uses the granular material damper 12 and the bag body damper 11 together is remarkable with respect to the vibration of the frequency of a still wider range (1-9Hz).

  Regarding the damping device (example of the present invention) composed of a bag damper, the relationship between the water volume ratio and the damping performance was examined.

  The volume of water in the bag damper shown in FIG. 1 was variously changed and sealed as follows. The volume ratio of the water volume to the bag volume is 104 g (25%), 208 g (50%), 311 g (75%), 385 g (93%) and 415 g (100%). Free vibration experiments were performed on steel pipe columns to which vibration damping devices of various capacities (volume ratios) were attached.

  FIG. 5 is a plot of the frequency (Hz) and damping constant (%) when the volume ratio of water is changed for this bag damper. It turns out that it is preferable to make the volume ratio of water into 50% or more practically.

  Two examples are shown when a damping device without an upper lid is attached to the column head of the standing member.

  FIG. 6 shows another two examples (examples of the present invention) when a vibration damping device comprising a bag damper is attached to the column head of the standing member.

  In FIG. 6A, the standing member 2 such as a lighting column is formed by standing a steel pipe column 4 having a circular cross section on a foundation 3. The vibration damping device including the bag body damper 11 includes a bag body 23 in which a liquid is sealed in a container whose inner and outer surfaces are hemispherical (inner surface dimensions are 127 mm inside diameter x 62 mm height). It is a bag body damper which accommodates one piece. Here, a bag damper containing one bag containing liquid is sealed in 195 g of water in a polyethylene ball having a diameter of 79 mm so that its capacity occupies 93% of the total volume in the bag. It is a thing.

  In FIG. 6 (b), the standing member 2 such as a lighting column is formed by standing a steel pipe column 4 having a circular cross section on a foundation 3. The vibration damping device including the bag body damper 11 includes a bag body 23 in which a liquid is sealed in a container whose inner and outer surfaces are hemispherical (inner surface dimensions are 127 mm inside diameter x 62 mm height). It is a bag body damper which accommodates three pieces. Here, each of the bag dampers containing three bags enclosing a liquid, each containing 65 g of water in a polyethylene ball having a diameter of 51 mm occupies 93% of the total volume in the bag. So that it is sealed.

  FIG. 7 is a plot of frequency (Hz) and damping constant (%) when a free vibration experiment is performed on a steel pipe column with respect to the above two vibration control devices.

  It can be seen that the bag damper (example of the present invention) in FIG. 6 (a) has a remarkable damping effect on vibrations in a wide range of frequencies with a peak at a frequency of 5 Hz. Moreover, it can be seen that the bag damper (example of the present invention) in FIG. 6B has a remarkable damping effect on vibrations in a wide range of frequencies with a peak at a frequency of 8 Hz. From these, it can be seen that the damping effect shifts to a high frequency when the bag body formed by enclosing the liquid is small.

  As described above, according to the present invention, there is provided a vibration damping device that has higher damping performance against vibrations whose frequency fluctuates over a wide range and is not affected by the vibration direction, and a standing member that has excellent vibration damping properties. can do.

2 Standing Member 3 Foundation 4 Steel Pipe Pillar 11 Bag Damper 12 Granular Damper 21 Container Top Cover 22 Granular Body 23 Bag Body 24 Mounting Tool 25 Rectangular Solid

Claims (6)

One or a plurality of flexible bags having a shape that is movably sealed inside are movably accommodated inside the container , and the bags collide with the inner wall of the container. Damping device consisting of a bag damper that can do . One or a plurality of flexible bags having a shape that is movably sealed inside are movably accommodated inside the container , and the bags collide with the inner wall of the container. A damping device comprising a bag body damper and a granular body damper in which a plurality of granular bodies are movably accommodated in a container having a curved inner surface at the bottom.   3. The vibration damping device according to claim 1, wherein the container has a rectangular parallelepiped shape with a flat bottom surface and a side wall. 4.   The vibration damping device according to claim 1 or 2, wherein the inner surface of the bottom surface of the container is a semi-spherical shape.   5. The vibration damping device according to claim 1, wherein the container has an upper lid.   A standing member to which any one of the vibration damping devices according to claim 1 is attached.

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