JPH10317320A - Damping device for parallel cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently, surely, and uniformly damp vibration in a certain direction, using a minimum facility. SOLUTION: At the opposite positions of a pair of cables 13, 13b extended parallel to each other, two fluid dampers 14, 15 are provided between the pair of cables 13a, 13b. The fluid dampers 14, 15 are placed at a predetermined angle to an axis (x) connecting the pair of cables 13a, 13b, and are placed to cross each other, so that vibration generated in the cables 13a, 13b in a certain direction is efficiently and uniformly damped by the fluid dampers 14, 15, whereby the vibration in a certain direction is efficiently, surely, and uniformly damped using the minimum facility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for suppressing vibration of cables installed in parallel, such as cables for suspension bridges, cable stayed bridges, and power transmission cables.

[0002]

2. Description of the Related Art The essential structure of a cable stayed bridge will be described with reference to FIG. FIG. 15 shows the appearance of the main part of the cable stayed bridge. As shown in the figure, a plurality of cables 3 are installed diagonally across the main tower 1 and the bridge girder 2, and the bridge girder 2 is supported by the plurality of cables 3. The cable 3 vibrates by receiving an external force such as wind, and causes the bridge girder 2 to shake.

Therefore, a cable stayed bridge is provided with a vibration damping device in order to suppress the vibration of the cable 3. As shown in the drawing, a damping wire 4 is arranged between the plurality of cables 3, and the cables 3 are connected to each other by the damping wire 4. The in-plane vibration (in-plane vibration) including the plurality of cables 3 is damped by the damping wire 4, and the shaking of the bridge girder 2 is suppressed.

As shown in FIG. 16 and FIG. 17 showing a view taken along the line XIII-XIII in FIG. 16, one fluid extends in a direction (θ = 90 degrees) perpendicular to the cable 3 over the cable 3 and the bridge girder 2. A vibration damping device provided with a damper 5 is also applied.
Fluid damper 5 attenuates in-plane vibration of cable 3,
The shaking of the bridge girder 2 is suppressed.

However, the cables 3 are connected to each other by the damping wires 4.
In a vibration damping device in which one fluid damper 5 is arranged between the cable 3 and the bridge girder 2, the in-plane vibration of the cable 3 can be suppressed. Vibration (out-of-plane vibration) cannot be suppressed.

Therefore, as shown in FIG.
Is orthogonal to the cable 3 and 90
A vibration damper provided with two fluid dampers 5 forming an angle of degree is used. In the vibration damping device provided with the two fluid dampers 5, the in-plane vibration and the out-of-plane vibration including the vertical and horizontal directions are attenuated, and the shaking of the bridge girder 2 is suppressed. For this reason, a cable-stayed bridge generally uses a vibration damping device provided with two fluid dampers 5.

[0007]

The cable-stayed bridge,
Two cables are respectively installed in parallel on both sides of the bridge girder 2 to form one cable 3. When an external force acts on the cable 3 in which two cables are installed in parallel by wind or the like, different swings are generated in the respective cables. That is, as shown in FIG.
When the wind acts from the side, large in-plane (x-direction) and out-of-plane (y-direction) vibrations are generated in the downstream cable 3b by the influence of the wind disturbed by the upstream cable 3a. Conversely, when wind acts on the other cable 3b side, large vibration is generated in the cable 3a.

However, if a vibration damping device having two fluid dampers 5 is applied to the cable 3 composed of the two cables 3a and 3b, two fluid dampers 5 are required for each of the cables 3a and 3b. Become. For this reason, the number of parts increases, the equipment cost increases, and the work of mounting and adjusting the fluid damper 5 becomes complicated, and the work time is lengthened.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration damping device for a parallel cable which can reliably suppress vibration of cables arranged in parallel with minimum equipment. I do.

[0010]

In order to achieve the above-mentioned object, according to the structure of the present invention, at least one damper is provided at a position facing a pair of cables laid in parallel, between the pair of cables, and at least one damper is provided. At least one is provided at a predetermined angle with respect to an axis connecting the pair of cables. Also, at least one damper is provided between the pair of cables at a position facing the pair of cables laid in parallel, and at least one of the dampers is disposed parallel to an axis connecting the pair of cables. It is characterized by having.

At least one damper is provided between the pair of cables at a position facing the pair of cables installed in parallel, and at least one of the dampers is perpendicular to an axis connecting the pair of cables. It is characterized by being provided. Further, two dampers are provided between the pair of cables at opposing positions of the pair of cables laid in parallel, and the dampers are disposed at a predetermined angle with respect to an axis connecting the pair of cables, and It is characterized by being arranged crossing.

In addition, two dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel, and one of the dampers is disposed obliquely with respect to an axis connecting the pair of cables. And the other of the dampers is disposed parallel or perpendicular to an axis connecting the pair of cables. Further, two dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel, and one of the dampers is disposed at a right angle to an axis connecting the pair of cables, and The other of the dampers is disposed parallel to an axis connecting the pair of cables.

[0013] Further, three or more dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel, and two of the dampers are provided with respect to an axis connecting the pair of cables. The dampers are arranged at a predetermined angle and intersect with each other, and the other dampers are arranged parallel or perpendicular to an axis connecting the pair of cables.

[0014]

FIG. 1 is a plan view of a bridge provided with a vibration damping device for a parallel cable according to a first embodiment of the present invention, and FIG. 2 shows details of the vibration damping device in FIG. FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a sectional view of the fluid damper. The illustrated first embodiment corresponds to the first and fourth aspects of the present invention.

As shown in FIG. 1, a pair of cables 13a and 13b are provided extending in parallel over the main tower 11 and the bridge girder 12, and a plurality of cables 13a and 13b are installed diagonally. The bridge girder 12 is supported by a plurality of cables 13a and 13b. Two fluid dampers 14 and 15 as dampers are provided between the pair of cables 13a and 13b at opposing positions of the pair of cables 13a and 13b to constitute a vibration damping device. The vibration of the cables 13a and 13b in any direction is damped by the vibration damping device including the two fluid dampers 14 and 15, and the sway of the bridge girder 12 is suppressed.

The details of the vibration damping device will be described with reference to FIGS. As shown in the figure, a mounting bracket 16 is fixed to the outer periphery of the cable 13a, 13b at a position facing the cable 13a, 13b, and the mounting bracket 16 is provided with an upper arm 17 and a lower arm 18. Tip portion 17a of upper arm 17 on one cable 13a side
One fluid damper 14 is provided between the distal end 18b of the lower arm 18 on the other cable 13b side and the distal end 18a of the lower arm 18 on the one cable 13a side and the other cable 13b.
The other fluid damper 15 is provided between the distal ends 17b of the upper arms 17 on the 13b side.

The fluid damper 14 and the fluid damper 15 are disposed at a predetermined angle (30 to 45 degrees) with respect to an axis x connecting the cables 13a and 13b, and the fluid damper 14 and the fluid damper 15 are They are arranged crossing each other. The body of the fluid damper 14 and the fluid damper 15 is supported by the cables 13a and 13b opposite to each other.

The structure of the fluid dampers 14 and 15 will be described with reference to FIG. The fluid dampers 14, 15
Have the same configuration, and the drawing shows a fluid damper 14. The cylinder 21 of the fluid damper 14 is filled with a viscous fluid 22 such as oil, and a piston 23 is slidably fitted to the cylinder 21. Cylinder 2 by piston 23
1 is divided into two chambers, and the two chambers are connected by a fluid passage 24. A flow control valve 25 is provided in the fluid passage 24, and the flow resistance of the fluid passage 24 is adjusted by adjusting the flow control valve 25.

At the tip of the piston 23, a movable mounting portion 2 is provided.
6 is provided, and a mounting portion 27 on the main body side is provided on the cylinder 21 side.
Is provided. Since the mounting portions 26 and 27 are rotatably supported on the distal ends 17a, 17b, 18a and 18b of the upper arm 17 and the lower arm 18 via pins and the like, respectively, the fluid damper 14 connects the pair of cables 13a and 13b. It is provided across. The vibration of the cables 13a and 13b is attenuated by the sliding resistance when the piston 23 slides in the cylinder 21 filled with the viscous fluid 22. At this time, by adjusting the flow resistance of the fluid passage 24 by adjusting the flow control valve 25, the sliding resistance of the piston 23 is adjusted and the damping characteristic is adjusted.

The operation of the above-described vibration damping device will be described. When an external force such as wind acts on the cable 13a or the cable 13b or a pair of cables 13a and 13b, vibrations in the direction of the axis x connecting the cables 13a and 13b or in a direction crossing the axis x occur. 15 attenuated.
Since the fluid dampers 14 and 15 are disposed at a predetermined angle with respect to the axis x and are disposed so as to intersect with each other, the fluid dampers 14 and 15 may be disposed in any direction including the direction of the axis x and the direction orthogonal to the axis x. A damping action is generated against the vibration.

For this reason, in the above-described vibration damping device, the vibration in any direction can be efficiently and evenly attenuated with the minimum equipment, and the sway of the bridge girder 12 can be reliably suppressed, and the equipment cost can be reduced. The work of mounting and adjusting the fluid dampers 14 and 15 can be simplified, and the working time can be shortened.

A second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a sectional view of the vibration damping device according to the second embodiment of the present invention, and FIG. 6 is a view taken along line VI-VI in FIG. Note that the same members as those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and redundant description is omitted. The second embodiment corresponds to the first aspect of the present invention.

As shown in the drawing, a lower arm 18 is provided on a mounting bracket 16 of one cable 13a at a position facing the cables 13a and 13b, and an upper arm 17 is provided on a mounting bracket 16 of the other cable 13b. ing. Then, the distal end portion 17a of the upper arm 17 of the cable 13a and the other cable
A fluid damper 1 is provided between the distal ends 18b of the lower arms 18 of the lower arm 13b.
A mounting portion 26 of the fluid damper 14 is rotatably supported by a tip 17b of the upper arm 17 via a pin or the like, and a mounting portion 27 is provided with a pin or the like at the tip 18a of the lower arm 18 by a pin. It is supported rotatably through the. Fluid damper 1
Reference numeral 4 denotes a state where the reference numeral 4 is arranged at a predetermined angle (30 to 45 degrees) with respect to an axis x connecting the cables 13a and 13b.

The mounting portion 26 of the fluid damper 14 is rotatably supported on the distal end 18a of the lower arm 18 via a pin or the like, and the mounting portion 27 is mounted on the distal end 17b of the upper arm 17 via a pin or the like. It may be rotatably supported. Also, the upper arm 17 is attached to the mounting bracket 16 of one of the cables 13a.
It is also possible to provide a lower arm 18 on the mounting bracket 16 of the other cable 13b to support the fluid damper 14 in a state opposite to that shown by 180 °.

The operation of the above-described vibration damping device will be described. When an external force such as wind acts on the cable 13a or the cable 13b or a pair of cables 13a and 13b, vibrations in the direction of the axis x connecting the cables 13a and 13b or in a direction crossing the axis x occur, the vibration is generated by the fluid damper 14. Attenuated. Since the fluid damper 14 is arranged to be inclined at a predetermined angle with respect to the axis x, a damping action is generated against vibration in any direction including the direction of the axis x and the direction orthogonal to the axis x.

For this reason, the above-mentioned vibration damping device can attenuate vibration in an arbitrary direction by extremely simple equipment to suppress the shaking of the bridge girder 12, and can be applied at a low cost to a portion where relatively small vibration occurs. can do.

A third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a sectional view of the vibration damping device according to the third embodiment of the present invention, and FIG. 8 is a view taken along line VIII-VIII in FIG. Note that the same members as those shown in FIGS. 5 and 6 are denoted by the same reference numerals, and redundant description is omitted. The third embodiment is described in claim 1, claim 2, and claim 5.
Corresponding to the invention of

As shown in the drawing, the vibration damping device of the third embodiment is different from the vibration damping device of the second embodiment shown in FIGS. 5 and 6 in addition to an axis x connecting the cables 13a and 13b. The fluid damper 15 is arranged in parallel. That is, the cable
A support member 31 is fixed to a portion of the mounting bracket 16 on the axis x of the mounting brackets 13a and 13b.
The mounting portion 26 of the fluid damper 15 is rotatably supported by a pin or the like, and the supporting member 31 on the other cable 13b side rotatably supports the mounting portion 27 of the fluid damper 15 by a pin or the like. .

The operation of the above-described vibration damping device will be described. When an external force such as wind acts on the cable 13a or the cable 13b or a pair of cables 13a and 13b, vibrations in the direction of the axis x connecting the cables 13a and 13b or in a direction crossing the axis x occur, the vibration is generated by the fluid damper 14. Attenuated. Since the fluid damper 14 is arranged to be inclined at a predetermined angle with respect to the axis x, a damping action is generated against vibration in any direction including the direction of the axis x and the direction orthogonal to the axis x. Further, the vibration in the direction parallel to the axis x connecting the cables 13a and 13b is reliably attenuated by the fluid damper 15.

Therefore, in the above-described vibration damping device, vibration in an arbitrary direction can be attenuated with minimum equipment,
Vibration in the direction parallel to the axis x connecting the cables 13a and 13b is reliably attenuated, and the sway of the bridge girder 12 can be suppressed reliably, and in places where vibration in the direction parallel to the axis x connecting the cables 13a and 13b is severe. Can be applied at low cost.

A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a sectional view of a vibration damping device according to a fourth embodiment of the present invention, and FIG. 10 is a view taken along line XX in FIG. Note that the same members as those shown in FIGS. 5 and 6 are denoted by the same reference numerals, and redundant description is omitted.
The fourth embodiment corresponds to the invention according to claims 1, 3 and 5.

As shown in the drawing, the vibration damping device of the fourth embodiment is different from the vibration damping device of the second embodiment shown in FIGS. 5 and 6 in addition to an axis x connecting the cables 13a and 13b. The fluid damper 15 is arranged at right angles. That is, the L-shaped arm 3 is provided above the mounting bracket 16 of one cable 13a.
3 and the L-shaped arm 33 is connected to the cables 13a and 13b.
And a portion 34 parallel to the axis x connecting the two, and the tip 34a of the portion 34 is located at the center between the cables 13a and 13b. An L-shaped arm 35 is provided below the mounting bracket 16 of the other cable 13b.
a, 13b and a portion 36 parallel to the axis x.
Is located at the center between the cables 13a and 13b.

A mounting portion 26 of the fluid damper 15 is rotatably supported by a pin or the like at a distal end 34a of a portion 34 of the arm 33, and a mounting portion 27 of the fluid damper 15 is mounted on a distal end 36a of the portion 36 of the arm 34. Are rotatably supported by pins or the like, and the fluid damper 15 is supported at right angles to the axis x connecting the cables 13a and 13b.

The operation of the above-described vibration damping device will be described. When an external force such as wind acts on the cable 13a or the cable 13b or a pair of cables 13a and 13b, vibrations in the direction of the axis x connecting the cables 13a and 13b or in a direction crossing the axis x occur, the vibration is generated by the fluid damper 14. Attenuated. Since the fluid damper 14 is arranged to be inclined at a predetermined angle with respect to the axis x, a damping action is generated against vibration in any direction including the direction of the axis x and the direction orthogonal to the axis x. Further, the vibration in the direction perpendicular to the axis x connecting the cables 13a and 13b is reliably attenuated by the fluid damper 15.

For this reason, in the above-described vibration damping device, vibration in an arbitrary direction is attenuated with minimum equipment,
Vibration in the direction perpendicular to the axis x connecting the cables 13a and 13b is reliably attenuated, and the sway of the bridge girder 12 can be suppressed reliably, and vibrations in the direction perpendicular to the axis x connecting the cables 13a and 13b are severe. Can be applied at low cost.

A fifth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a sectional view of a vibration damping device according to a fifth embodiment of the present invention, and FIG.
I-XII view is shown. Note that the same members as those shown in FIGS. 7 and 8 are denoted by the same reference numerals, and redundant description is omitted. The fifth embodiment corresponds to the sixth aspect of the present invention.

As shown in the figure, a fluid damper 15 is disposed in parallel with an axis x connecting the cables 13a and 13b.
A fluid damper 14 is disposed at right angles to an axis x connecting 13a and 13b. That is, the mounting bracket 16 of the one cable 13a
An L-shaped arm 41 is provided below the L-shaped arm 41. The L-shaped arm 41 has a portion 42 parallel to the axis x connecting the cables 13a and 13b, and a distal end 42a of the portion 42 is connected to the cables 13a and 13b.
It is located in the middle between. An L-shaped arm 43 is provided above the mounting bracket 16 of the other cable 13b. The L-shaped arm 43 has a portion 44 parallel to the axis x connecting the cables 13a and 13b. Portion 44a is cable 13
It is located in the center between a and 13b.

A mounting portion 27 of the fluid damper 14 is rotatably supported by a pin or the like at a distal end 42a of a portion 42 of the arm 41, and a mounting portion 26 of the fluid damper 14 is mounted on a distal end 44a of a portion 44 of the arm 43. Are rotatably supported by pins or the like, and the fluid damper 14 is supported at right angles to the axis x connecting the cables 13a and 13b.

The operation of the above-described vibration damping device will be described. When an external force such as wind acts on the cable 13a or the cable 13b or a pair of cables 13a and 13b, vibrations in the direction of the axis x connecting the cables 13a and 13b or in a direction crossing the axis x occur. 15 attenuated.
Since the fluid damper 14 is disposed at a right angle to the axis x and the fluid damper 15 is disposed parallel to the axis x, any direction including the direction of the axis x and the direction orthogonal to the axis x can be used. Two fluid dampers 14, 1 for vibration in the direction
5 causes a damping effect. Also, cables 13a and 13b
The vibration in the direction perpendicular to the axis x connecting the cables 13a and 13b is reliably damped by the fluid damper 14, and the vibration in the direction parallel to the axis x connecting the cables 13a and 13b is reliably damped by the fluid damper 15.

For this reason, in the above-described vibration damping device, vibration in an arbitrary direction can be attenuated with minimum equipment,
Vibration in directions parallel and perpendicular to the axis x connecting the cables 13a and 13b can be reliably attenuated, and swaying of the bridge girder 12 can be suppressed reliably, and vibrations in directions parallel and perpendicular to the axis x connecting the cables 13a and 13b can be obtained. Can be applied at a low cost in places where the intensity is high.

A sixth embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a sectional view of the vibration damping device according to the sixth embodiment of the present invention, and FIG.
V-XIV Viewed from the arrow. Note that the same members as those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and redundant description is omitted. The sixth embodiment corresponds to a seventh aspect of the present invention.

As shown in the figure, the fluid damper 14 and the fluid damper 15 are disposed at a predetermined angle (30 to 45 degrees) with respect to an axis x connecting the cables 13a and 13b. The fluid damper 14 and the fluid damper 15 are arranged to cross each other. A fluid damper 52 is provided in parallel with the axis x connecting the cables 13a and 13b. That is, a supporting member 51 is fixed to a portion of the mounting bracket 16 of the cables 13a and 13b on the axis x, and a supporting member 51 of the one cable 13a is provided with a fluid damper 52 having the same configuration as the fluid damper 14 (15). The mounting portion 53 is rotatably supported by a pin or the like, and the mounting portion 54 of the fluid damper 52 is rotatably supported by the support member 51 on the other cable 13b side by a pin or the like. The mounting portion 53 is provided on the piston side (corresponding to the mounting portion 26), and the mounting portion 54 is provided on the main body side (corresponding to the mounting portion 27).

The operation of the above-described vibration damping device will be described. When an external force such as wind acts on the cable 13a or the cable 13b or a pair of cables 13a and 13b, vibrations in the direction of the axis x connecting the cables 13a and 13b or in a direction crossing the axis x occur. 15 attenuated.
Since the fluid dampers 14 and 15 are disposed at a predetermined angle with respect to the axis x and are disposed so as to intersect with each other, the fluid dampers 14 and 15 may be disposed in any direction including the direction of the axis x and the direction orthogonal to the axis x. A damping action is generated against the vibration. Also, cable 13
Vibration in the direction parallel to the axis x connecting a, 13b
2 reliably attenuates.

Therefore, in the above-described vibration damping device, vibrations in any direction can be efficiently and evenly attenuated with minimum equipment, and vibrations in a direction parallel to the axis x connecting the cables 13a and 13b are reliably attenuated. However, the swing of the bridge girder 12 can be reliably suppressed, and the bridge girder 12 can be applied at a low cost to a place where vibration in a direction parallel to the axis x connecting the cables 13a and 13b is particularly severe. The fluid damper 52 may be disposed in a direction perpendicular to the axis x connecting the cables 13a and 13b, and the fluid damper 52 may be applied to a place where vibration in the direction perpendicular to the axis x is particularly severe.

[0045]

According to the vibration damping device for a parallel cable according to the present invention, at least one damper is provided between the pair of cables at a position facing the pair of cables installed in parallel. Since at least one of the cables is disposed at a predetermined angle with respect to an axis connecting the pair of cables, vibrations generated in the cables in arbitrary directions are attenuated by the dampers. As a result, vibrations in any direction can be reliably attenuated with a minimum of equipment, making it possible to reduce the equipment cost, simplify the work of installing and adjusting the damper, and further reduce the work time. Become.

According to a second aspect of the present invention, there is provided a vibration damping device for a parallel cable, wherein at least one damper is provided between the pair of cables at a position facing the pair of cables installed in parallel, and at least one of the dampers is provided. One is arranged in parallel with the axis connecting the pair of cables, so that the vibration in the direction generated in parallel between the cables is attenuated by the damper. As a result, the vibration in the direction parallel to the cable can be reliably attenuated with minimum equipment.

According to a third aspect of the present invention, there is provided a vibration damping device for a parallel cable, wherein at least one damper is provided between the pair of cables at a position facing the pair of cables installed in parallel, and at least one of the dampers is provided. One is disposed at right angles to the axis connecting the pair of cables, so that the vibration in the direction generated orthogonally between the cables is attenuated by the damper. As a result, it is possible to reliably attenuate the vibration in the direction perpendicular to the space between the cables with minimum equipment.

According to a fourth aspect of the present invention, in the vibration damping device for a parallel cable according to the present invention, two dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel, and the dampers are connected to the pair of cables. Since the cables are arranged at a predetermined angle with respect to the axis connecting the cables and are arranged so as to cross each other, vibrations in arbitrary directions generated in the cables are efficiently and uniformly attenuated by the dampers. As a result, vibrations in any direction can be efficiently and reliably attenuated with a minimum amount of equipment, reducing equipment costs, simplifying the work of mounting and adjusting the damper, and further reducing the working time. It becomes possible to shorten.

According to a fifth aspect of the present invention, there is provided a vibration damping device for a parallel cable, wherein two dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel, and one of the dampers is provided with the damper. Since the other of the dampers is disposed obliquely with respect to an axis connecting the pair of cables and the other of the dampers is disposed parallel or perpendicular to the axis connecting the pair of cables, any direction generated in the cables Is attenuated by one damper, and the vibration in a direction that is generated between the cables in a parallel or perpendicular direction is attenuated by the other damper. As a result, vibrations in any direction and in a direction parallel or perpendicular to the cable can be attenuated with minimum equipment.

According to a sixth aspect of the present invention, there is provided a vibration damping device for a parallel cable according to the present invention, wherein two dampers are provided between the pair of cables at opposite positions of a pair of cables installed in parallel, and one of the dampers is provided with the damper. Since the damper is disposed at right angles to the axis connecting the pair of cables and the other of the dampers is disposed parallel to the axis connecting the pair of cables, vibrations in any direction generated in the cables may occur. Vibration in directions that occur parallel and at right angles between the cables is attenuated by each damper, while being attenuated by the two dampers. As a result, vibrations in any direction can be attenuated with minimum equipment, and vibrations in directions parallel and perpendicular to the cables can be reliably attenuated.

According to a seventh aspect of the present invention, in the vibration damping device for a parallel cable, three or more dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel. Are disposed at a predetermined angle with respect to an axis connecting the pair of cables and are disposed so as to cross each other, and the other dampers are parallel or perpendicular to the axis connecting the pair of cables. Because of the arrangement, vibrations in any direction generated in the cable are attenuated by the two dampers, and vibrations generated in a direction parallel or perpendicular to the cables are attenuated by the other dampers. As a result, vibrations in any direction can be efficiently and reliably attenuated with minimum equipment, and vibrations in the direction parallel or perpendicular to the cables can be reliably attenuated.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a bridge provided with a parallel cable damping device according to a first embodiment of the present invention.

FIG. 2 is a view taken along line II-II in FIG.

FIG. 3 is a view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view of a fluid damper.

FIG. 5 is a sectional view of a vibration damping device according to a second embodiment of the present invention.

FIG. 6 is a view taken along line VI-VI in FIG. 5;

FIG. 7 is a sectional view of a vibration damping device according to a third embodiment of the present invention.

FIG. 8 is a view taken along line VIII-VIII in FIG. 7;

FIG. 9 is a sectional view of a vibration damping device according to a fourth embodiment of the present invention.

FIG. 10 is a view taken along line XX in FIG. 9;

FIG. 11 is a sectional view of a vibration damping device according to a fifth embodiment of the present invention.

FIG. 12 is a view taken in the direction of arrows XII-XII in FIG. 11;

FIG. 13 is a sectional view of a vibration damping device according to a sixth embodiment of the present invention.

FIG. 14 is a view taken in the direction of arrows XIV-XIV in FIG. 13;

FIG. 15 is an external view of a main part of a cable-stayed bridge.

FIG. 16 is an explanatory diagram of a conventional vibration damping device.

FIG. 17 is a diagram along line XIII-XIII in FIG. 16;

FIG. 18 is an explanatory view of a conventional vibration damping device.

FIG. 19 is an explanatory diagram showing a state of vibration.

[Explanation of symbols]

 11 Main tower 12 Bridge girder 13a, 13b Cable 14, 15 Fluid damper 16 Mounting bracket 17 Upper arm 17a, 17b Tip 18a, 18b Tip 18 Lower arm 21 Cylinder 22 Viscous fluid 23 Piston 24 Fluid passage 25 Flow control valves 26, 27 Mounting part 31 Support member 33, 35 Arm 34, 36 Site 34a, 36a Tip 41, 43 Arm 42, 44 Site 51 Support member 52 Fluid damper 53, 54 Mounting part

Claims (7)

[Claims] At least one damper is provided between said pair of cables at a position opposite to a pair of cables installed in parallel, and at least one of said dampers has a predetermined position with respect to an axis connecting said pair of cables. A vibration damping device for a parallel cable, which is arranged at an angle. 2. At least one damper is provided between the pair of cables at a position facing the pair of cables installed in parallel, and at least one of the dampers is parallel to an axis connecting the pair of cables. A parallel cable damping device, which is provided. 3. At least one damper is provided between the pair of cables at a position facing the pair of cables installed in parallel, and at least one of the dampers is perpendicular to an axis connecting the pair of cables. A parallel cable damping device, which is provided. 4. A pair of cables installed in parallel, two dampers are provided between the pair of cables at opposing positions, and the dampers are disposed at a predetermined angle with respect to an axis connecting the pair of cables. A vibration damping device for a parallel cable, wherein the vibration damping device is arranged to cross each other. 5. A damper is provided at a position opposite to a pair of cables laid in parallel between said pair of cables, and one of said dampers is disposed obliquely with respect to an axis connecting said pair of cables. A damping device for a parallel cable, wherein the other of the dampers is disposed parallel or perpendicular to an axis connecting the pair of cables. 6. A damper is provided at a position opposed to a pair of cables laid in parallel between said pair of cables, and one of said dampers is disposed at right angles to an axis connecting said pair of cables. The other damper is disposed in parallel with an axis connecting the pair of cables. 7. At least three dampers are provided between the pair of cables at opposing positions of the pair of cables installed in parallel, and two of the dampers are provided with respect to an axis connecting the pair of cables. Wherein the dampers are arranged at a predetermined angle and intersect with each other, and the other dampers are arranged in parallel or at right angles to an axis connecting the pair of cables. Shaking device.