JP2002021919A - Vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damping device capable of further effectively reducing vibration of a columnar structure excited by fluid such as wind. SOLUTION: This vibration damping member 1 is composed of a base part 3 rotatably installed on an outer peripheral surface of a cable stayed bridge cable 2 and a straightening part 4 as a straightening body formed on the outer peripheral surface of the base part 3. An inner peripheral surface of the base part 3 is provided with plural roller members 12 for adjusting rotational resistance to the cable stayed bridge cable 2 of the base part 3 so as to become 0.01 to 2.0. The direction of the straightening body does not change even if wind force and the wind direction change a little by the rotational resistance of the base part, and the direction of the straightening body changes when the wind force becomes large to a certain degree.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cable-stayed bridge cable,
Suspension bridge cables, parallel cables, electric wires, chimneys, struts, street lights, street lights, traffic lights, lightning rods, windmills, road signs, antennas, telephone poles, tower structures, thermometers drawn into the flow in pipes, etc. The present invention relates to a vibration control device for a placed pillar-shaped structure.

[0002]

2. Description of the Related Art As shown in FIG. 9, a pillar-shaped structure 41 placed in air, steam, water or other various fluids generates a resistance against a force received from a fluid in a flow direction. Then, the flow is separated on the surface, and a Karman vortex street 42 is regularly generated on the leeward side, and a lift is generated in a direction perpendicular to the flow, so that the columnar structure 41 is vibrated.

Conventionally, as a method of reducing vibration excited by a fluid, there has been proposed a method in which a rectifying blade is rotatably mounted around a columnar structure such as a duct in a steel tower or various plants (Japanese Patent Application Laid-Open No. Sho. 61-146975). This method is based on the premise that when the wind blows, the rectifying blades flutter toward the leeward side, and the rotational resistance of the rectifying blades is close to zero.

[0004]

However, the wind direction and speed of the actual wind change moment by moment, and when the rotational resistance of the rectifier blade is zero, the wind responds to the strength of the wind and slight changes in the wind direction. There is a problem that the rectifying wings flutter, and the vibration of the structure and the vibration of the rectifying wings resonate to prevent the vibrations, but rather induce the vibrations.

Accordingly, the present invention provides a vibration damping device capable of more effectively reducing vibration of a columnar structure excited by a fluid such as wind.

[0006]

According to a first aspect of the present invention, there is provided a vibration-damping device, comprising: a column-shaped vibration-suppressed body; In a vibration damping device formed with a rectifier extending in a direction orthogonal to the longitudinal direction of the vibration body, the base has a rotation resistance such that the base rotates following the change in the flow direction of the fluid with a delay. And

As shown in FIG. 8, the rotation resistance T (N · m) is a torque generated when the base is rotated with respect to the center O of the vibration-suppressed body. Assuming that the friction coefficient is μ, the clamping force of the base with respect to the damped body is P (N), and the radius of the damped body is r (m), T (N · m) = μ × P (N) × r (m).

According to a second aspect of the present invention, in the vibration damping device, a coefficient of friction of a contact surface between the base and the body to be damped is 0.01 to 2.0.

According to a third aspect of the present invention, in the vibration damping device, a roller member is provided on an inner peripheral surface of the base portion, and the rotation resistance of the base portion is set so as to be delayed in a change in the flow direction of the fluid so that the rectifying member faces the flow direction. Has been adjusted.

In this case, the rotation resistance is adjusted, for example, by adjusting the rotation torque in the rotation of the roller member, and a predetermined friction coefficient μ between the vibration-suppressed body and the base in the rotation resistance T is set. Adjustment is made so as to give the same rotational resistance as in a certain case.

According to a fourth aspect of the present invention, in the vibration damping device, a fixed member fixedly mounted on an outer peripheral surface of a columnar vibration-suppressed body, and a sliding member slidably and rotatably mounted on the outer peripheral surface of the fixed member. A rectifier extending from the sliding member in a direction orthogonal to the longitudinal direction of the columnar vibration-suppressed member, such that the rectifier faces the flow direction with a delay in a change in the flow direction of the fluid. The rotation resistance of the sliding member is adjusted.

According to a fifth aspect of the present invention, in the vibration damping device, the rectifying body has any one of a streamlined shape, a wing shape, and an elliptical shape.

According to a sixth aspect of the present invention, in the vibration damping device, the rectifier is a plate member extending in a longitudinal direction of the columnar vibration-suppressed body.

According to a seventh aspect of the present invention, in the vibration damping device, the rectifier is formed of two parallel plate members extending in a longitudinal direction of the columnar damped member.

According to an eighth aspect of the present invention, in the above-mentioned vibration damping device, a stopper is provided on a lower side or both upper and lower sides of the vibration damping device to prevent the mounting position from being shifted.

According to a ninth aspect of the present invention, in the vibration damping device,
It is characterized in that it has a divided surface divided in the longitudinal direction of the columnar vibration-suppressed body.

According to a tenth aspect of the present invention, in the vibration damping device, the divided surfaces of the base portion have a zigzag shape fitted to each other, and the divided surfaces are fitted to each other in a longitudinal direction. A mounting pin is inserted into a hole formed so as to penetrate in the direction, and is attached to the column-shaped vibration-suppressed body.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vibration damping device according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the vibration damping device 1 has a base 3 which is rotatably mounted on an outer peripheral surface 2a of an existing cable-stayed bridge cable 2 as a columnar damped body with a predetermined rotation resistance. And a rectifier 4 as a rectifier.

As shown in the expanded state in FIG. 2A, the base 3 can be opened and closed by a hinge 8 with a substantially cylindrical member divided into three parts in the circumferential direction. It is connected to. Left and right side members (5, 7)
Are divided surfaces (5a, 7) having a zigzag shape fitted to each other.
a), the mounting pins 11 are inserted into and connected to the holes 10 communicating in the longitudinal direction with the divided surfaces (5a, 7a) fitted together. The base 3 can be attached to the existing cable-stayed bridge cable 2 by opening the members (5, 7) on both the left and right sides.

A plurality of roller members 12 are rotatably mounted on the inner peripheral surface of the base 3. The roller member 12 is adjusted so that the base 3 has a predetermined rotation resistance with respect to the cable-stayed bridge cable 2. The adjustment of the rotation resistance is performed by adjusting the rotation torque of the rotation of the roller member 12. That is, in this embodiment, since the inner diameter of the base 3 and the outer diameter of the cable-stayed bridge cable 2 are constant (the tightening force is constant), by adjusting the rotation torque of the roller member 12 to rotate, the base 3 and the cable 3 are controlled. Rotational resistance can be adjusted in the same manner as when a predetermined friction coefficient μ is adjusted between the cable-stayed bridge cable 2 and the vibration body.

The rotational resistance of the base 3 to the cable-stayed bridge cable 2 is adjusted so that the friction coefficient μ between the base 3 and the cable-stayed bridge cable 2 that is a vibration-controlled body is 0.01 to 2.0. I do. Accordingly, when the force applied to the rectifying unit 4 from the wind is weak, the base 3 does not rotate and the direction of the rectifying unit 4 does not change.

That is, when the rotational resistance is not intentionally applied as in the prior art (that is, when the friction coefficient μ is 0.005).
Is less than. ), A predetermined time is required from the change of the wind direction to the follow-up of the direction of the rectifying unit 4 due to the rotational resistance of the base 3, so that the swinging motion of the rectifying unit 4 is affected by the wind and the cable-stayed bridge cable 2 It does not resonate with the vibration excited at the moment. The coefficient of friction μ between the base 3 and the cable-stayed bridge cable 2 is preferably adjusted between 0.05 and 1.5, more preferably between 0.1 and 1.0.

On the lower side of the base 3, a stopper 13 for preventing a displacement of the vibration damping device 1 is mounted. The stopper 13 is a divided circular ring-shaped member, and is a bolt 14 that is attached to the cable-stayed bridge cable 2 and connects the divided portions.
And is fixed to the cable-stayed bridge cable 2. The stoppers 13 may be provided on both upper and lower sides of the base 3.

The rectifying section 4 is connected to the cable-stayed bridge cable 2 from the base 3.
The cable-stayed bridge extends in a direction perpendicular to the longitudinal direction of the cable-stayed bridge and acts to regulate the flow of wind around the cable-stayed bridge cable 2 and suppresses the generation of Karman vortices on the leeward side. The force (drag) received from the wind and the force (lift) in the direction perpendicular to the wind can be reduced, and the vibration excited by the wind can be suppressed.

As the shape of the rectification unit 4, various shapes other than the streamline shape can be adopted. Examples of the vibration damping device according to the present invention in which the rectifying unit 4 is replaced with another shape include those shown in FIGS. The vibration damping device 21 shown in FIG. 3 includes an oval rectifying portion 22 extending from the base 3 in a direction perpendicular to the longitudinal direction of the cable-stayed bridge cable 2. Damping device 23 shown in FIG.
Has a wing-shaped rectifying portion 24 extending from the base 3 in a direction perpendicular to the longitudinal direction of the cable-stayed bridge cable 2. The vibration damping device 25 shown in FIG. 5 includes a plate-shaped rectifying portion 26 extending from the base 3 in a direction perpendicular to the longitudinal direction of the cable-stayed bridge cable 2. Further, the vibration damping device 27 shown in FIG. 6 includes a rectification unit 28 in which two plate-shaped members extending in a direction perpendicular to the longitudinal direction of the cable-stayed bridge cable 2 from the base extend in parallel. . According to the experiment, as shown in FIG. 1, by making the shape of the rectifying section 4 streamlined, the drag is reduced to 1/20 of that in the case of a circular cross section.
And the best result is obtained.

The material of the vibration damping device main body including the base 3 and the rectifying portion 4 may be either a metal or non-metallic material, and is preferably a lightweight material such as plastic or FRP.

Further, the base 3 may be replaced with a member provided with a roller member to have a sliding pair structure. For example, FIG.
(A) As shown in (b), a fixed member 31 fixedly mounted on the outer peripheral surface of the cable-stayed bridge cable 2, a sliding member 32 slidably mounted on the outer peripheral surface of the fixed member 31, Moving member 3
The cable-stayed bridge cable 2 may be provided with a streamline rectifying portion 33 extending in a direction perpendicular to the longitudinal direction of the cable-stayed bridge cable 2. The sliding member 32 is a substantially cylindrical member that can be attached to the fixed member 31. The sliding member 32 opens a split slit 34 formed in the longitudinal direction, fits the fixed member 31, and uses a bolt 35 disposed between the split slits 34. It can be connected to and attached to the fixing member 31 with a predetermined tightening force. The rotation resistance of the sliding member 32 with respect to the fixed member 31 can be adjusted by adjusting the tightening force of the sliding member 32 with respect to the fixed member 31 with the bolt 35. The rotation resistance of the sliding member 32 is
1 and the sliding member 32 have a friction coefficient μ of 0.01 to 2.
As 0, the tightening force between the fixed member 31 and the sliding member 32 is adjusted. The coefficient of friction μ between the fixing member 31 and the sliding member 32 is preferably adjusted between 0.05 and 1.5, and more preferably between 0.1 and 1.0. In the above embodiment, the outer peripheral surface of the cable-stayed bridge cable 2 may be used as a fixing member, and the sliding member 32 may be directly attached to the outer peripheral surface of the cable-stayed bridge cable 2.

The fixed member 31 and the sliding member 32 are, for example,
Materials such as copper, white metal, stainless steel, lead, zinc, silver, nickel, molybdenum, kermet, magnolia, phosphor bronze, copper, nylon, Teflon (registered trademark), and FRP are selected so that a desired friction coefficient can be selected. Just choose.

Although the embodiment of the present invention has been described above, the vibration damping device of the present invention is not limited to the above embodiment.

The structure to which the vibration damping device is mounted is not limited to the cable-stayed bridge cable, but can be mounted to various pillar-shaped structures. If the cross-sectional shape of the columnar vibration-suppressed body to which the vibration damping device is to be mounted is not circular, a cylindrical member having a circular cross-section on the outer peripheral surface is mounted on the outer peripheral surface of the vibration-suppressed body, and its outer periphery is mounted. It is advisable to mount the above-mentioned vibration damping device on the surface.

The shape of the rectifying section is not limited to the above embodiment, but various shapes can be adopted.

[0033]

According to a first aspect of the present invention, there is provided a vibration damping device comprising: a base portion rotatably mounted in a circumferential direction on an outer peripheral surface of a columnar vibration-suppressed body;
In a vibration damping device comprising a rectifier extending from the base in a direction perpendicular to a longitudinal direction of the columnar vibration-suppressed body, the base rotates following a change in a flow direction of a fluid with a delay. With such a rotational resistance, the rotational resistance of the base portion causes the direction of the rectifier to change with a delay with respect to a change in the flow direction of the fluid. Can be effectively reduced. Further, since the movement of the rectifier is slowed down in this manner, the rectifier and the columnar damped body do not resonate, and vibration of a structure excited by a fluid such as wind can be reduced more effectively.

In the vibration damping device according to the second aspect, the friction coefficient between the contact surface of the base and the object to be damped is set to 0.01 to 2.0. The direction of the rectifier does not change even if it changes to, and the direction of the rectifier changes when the wind power increases to some extent.

According to a third aspect of the present invention, in the vibration damping device, a roller member is provided on an inner peripheral surface of the base, and the rotation resistance of the base is delayed so as to delay the change in the flow direction of the fluid so that the rectifier faces the flow direction. By adjusting the rolling resistance of the roller member, the rotation resistance of the base can be adjusted, and the adjustment of the rotation resistance of the base can be easily performed.

In the vibration damping device according to the fourth aspect, a fixed member fixedly mounted on an outer peripheral surface of a columnar vibration-suppressed body, and a sliding member slidably mounted on the outer peripheral surface of the fixed member. A rectifier extending from the sliding member in a direction orthogonal to the longitudinal direction of the columnar vibration-suppressed member, such that the rectifier faces the flow direction with a delay in a change in the flow direction of the fluid. Since the rotational resistance of the sliding member is adjusted, the rotational resistance of the sliding member causes the direction of the rectifier to change with a delay with respect to the change in the flow direction of the fluid. Vibration generated in the vibrating body can be effectively reduced. Also,
Since the movement of the rectifier becomes dull in this manner, the rectifier and the columnar vibration-suppressed body do not resonate, and vibration of a structure excited by a fluid such as wind can be reduced more effectively.

According to a fifth aspect of the present invention, since the flow regulating body has any one of a streamlined shape, an airfoil shape, and an elliptical shape, the separation of fluid from the surface can be reduced. .

In the vibration damping device according to the sixth aspect, since the straightening body is a plate extending in the longitudinal direction of the columnar vibration-damping body, the separation of the fluid from the surface can be reduced.

According to a seventh aspect of the present invention, in the vibration damping device, since the straightening member is formed of two parallel plate members extending in the longitudinal direction of the columnar damped member, separation of fluid from the surface is reduced. can do.

In the vibration damping device according to the present invention, since the stopper for preventing the mounting position from being shifted below or above and below the vibration damping device is provided, the position of the vibration damping device does not shift.

According to a ninth aspect of the present invention, in the vibration damping device,
Since a columnar vibration-suppressed body is provided with a divided surface in the longitudinal direction, it can be attached to an existing object such as a cable-stayed bridge cable.

According to a tenth aspect of the present invention, in the vibration damping device, the divided surfaces of the base have a zigzag shape that fits each other, and the divided surfaces are fitted to each other in a longitudinal direction of the columnar vibration-suppressed body. Since the mounting pin is inserted into the hole formed so as to penetrate in the direction, and is mounted on the columnar vibration-suppressed body, the mounting surface can be mounted with the divided surface open, and the vibration-damping device can be easily mounted.

[Brief description of the drawings]

FIG. 1 is a perspective view of a vibration damping device according to an embodiment of the present invention.

FIG. 2A is a developed view of a vibration damping device according to an embodiment of the present invention, and FIG. 2B is a diagram showing a mounted state of the vibration damping device.

FIG. 3 is a perspective view of a vibration damping device according to another embodiment of the present invention.

FIG. 4 is a perspective view of a vibration damping device according to another embodiment of the present invention.

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

FIG. 6 is a perspective view of a vibration damping device according to another embodiment of the present invention.

7A is a perspective view showing a vibration damping device provided with a base composed of a sliding pair, and FIG. 7B is a longitudinal sectional view of the vibration damping device.

FIG. 8 is a diagram showing the concept of a rotational resistance in the present invention.

FIG. 9 is a diagram showing Karman vortex streets generated in a columnar structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Damping member 2 Cable-stayed bridge cable 3 Base 4 Rectifier 8, 9 Dividing surface 11 Mounting pin

Claims (10)

[Claims] A base extending from the base in a direction perpendicular to the longitudinal direction of the columnar vibration-suppressed body, the base being rotatably mounted on the outer peripheral surface of the columnar vibration-suppressed body in the circumferential direction. A damping device comprising a fluid, wherein the base has a rotational resistance such that the flow body is oriented in the flow direction with a delay in a change in the flow direction of the fluid. 2. The vibration damping device according to claim 1, wherein a coefficient of friction of a contact surface between the base and the damped body is 0.01 to 2.0. 3. A roller member is provided on the inner peripheral surface of the base, and the rotation resistance of the base is adjusted so that the flow regulating body is oriented in the flow direction with a delay in a change in the flow direction of the fluid. The vibration damping device according to claim 1. 4. A fixed member fixedly mounted on an outer peripheral surface of a columnar vibration-suppressed body, a sliding member slidably and rotatably mounted on an outer peripheral surface of the fixed member, and A rectifying body extending in a direction orthogonal to the longitudinal direction of the columnar vibration-suppressed body; and a rotation resistance of the sliding member so that the rectifying body faces the flow direction with a delay in a change in the flow direction of the fluid. The vibration damping device characterized by having adjusted. 5. The vibration damping device according to claim 1, wherein said straightening body has any one of a streamlined shape, an airfoil shape, and an elliptical shape. 6. The vibration damping device according to claim 1, wherein the straightening body is a plate member extending in a longitudinal direction of the columnar vibration damping body. 7. The vibration damping device according to claim 1, wherein the straightening body is two parallel plate members extending in the longitudinal direction of the columnar vibration damping body. 8. The vibration damping device according to claim 1, further comprising a stopper provided on a lower side or upper and lower sides of the vibration damping device to prevent the mounting position from being shifted. Damping device. 9. The vibration damping device according to claim 1, wherein the base has a dividing surface which is divided in a longitudinal direction of the columnar vibration damping body. 10. A hole having a zigzag shape in which divided surfaces of said base are fitted to each other, and formed so that said divided surfaces penetrate in a longitudinal direction of a columnar vibration-suppressed body in a state where said divided surfaces are fitted. The vibration damping device according to claim 9, wherein a mounting pin is inserted through the vibration damping member, and the vibration damping device is mounted on the columnar vibration-suppressed body.