JP2008082453A - Damping device, and road bridge and pedestrian bridge with superior damping performance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping device, a pedestrian bridge, and a road bridge capable of damping vibration due to vertical shaking generated in a structure caused by passage of vehicles, walking, an earthquake, or the like. <P>SOLUTION: The damping device is comprised of a spring 13 having a weight 14 on a lower end and an upper part attached to an upper member 5 of a body to be damped, and a suspension member 13 suspended from the weight 14. It is characterized by that a lower part of the suspension member 13 contacts an upper face of a component 6 of the body to be damped. An object comprised by connecting a plurality of metal bodies, a metal chain, or a metal wire can be used as the suspension member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration damping device for attenuating vibration generated in a structure such as a road bridge or a footbridge due to passing of a vehicle, an earthquake, or the like, and a road excellent in vibration damping performance provided with the vibration damping device. Regarding bridges and footbridges.

Structures such as road bridges and pedestrian bridges may be swayed due to resonance phenomena caused by wind, earthquake, vehicle running, road vibration caused by walking, and the like. When such shaking occurs, damage such as metal fatigue is likely to occur in the structure due to the shaking, and the damage is promoted. In addition, there is a problem that the life of vertical erection members such as lighting columns, sign columns, and signal columns attached to the structure is shortened due to vibrations generated. There is also a problem that makes people feel uncomfortable.

  Various damping devices for preventing the shaking of the structure due to such a resonance phenomenon have been conventionally developed.

  For example, Patent Literature 1 discloses a vibration damping device that can be attached to a vertical standing member such as an illumination column.

  In other words, a metal chain or metal wire is hung with a free vibration site inside the vertical hollow body, and the distance between the chain or wire and the inner wall of the vertical hollow body is maintained equivalent. It is a vibration device, and this vibration damping device is attached to the outside or the inside of the vertical erection member, thereby attenuating the vibration caused by the lateral vibration applied to the vertical erection member.

  FIG. 7 shows an example of the vibration damping device described in Patent Document 1. (a) is one longitudinal sectional view passing through the axis of the vibration damping device, and (b) is a longitudinal sectional view in a direction rotated by 90 ° with respect to (a).

  The vibration damping device includes a vertical hollow body 32 made of a circular steel pipe and a suspension member of a steel chain 29 suspended therein. The upper end of the steel chain 29 is supported by a fixing hook 31 fixedly attached to an end plate 30 installed on the upper part of the vertical hollow body 32. Therefore, the steel chain 29 forms a free vibration part except for the upper end.

  Here, since the steel chain 29 is suspended vertically at the center of the circular steel pipe, in the absence of vibration, the distance d between the outer surface of the steel chain 29 and the inner wall of the vertical hollow body 32 is a circular steel pipe. Is kept equivalent inside.

  The vibration caused by a resonance phenomenon caused by wind, earthquake, vehicle running, road vibration caused by walking, etc. is transmitted to the vibration damping device, and excitation occurs. At that time, both the vertical hollow body 32 and the steel chain 29 vibrate, but the free vibration part of the steel chain 29 vibrates in a different manner from the vertical hollow body 32, so that the free vibration part of the steel chain 29 is It collides with the inner wall surface of the vertical hollow body 32. As a result, the vibration energy of the vertical hollow body 32 is dissipated, so that the vibration of the vertical hollow body 32 is rapidly attenuated and the vibration is stopped.

  In this way, by suspending the steel chain 29 inside the vertical hollow body 32, it is possible to form a vibration damping device that can attenuate and stop vibration applied to the vertical hollow body.

  When the vertical erection member such as a lighting column is a hollow vertical member, the vibration control device is attached to the outside or the inside of the vertical erection member, thereby causing a vibration applied to the vertical erection member. The vibration can be propagated to the vertical hollow body constituting the vibration damping device, and the vibration can be attenuated in the vertical hollow body to be stopped.

  Patent Document 2 discloses another example of a vibration damping device used for a vertical standing member such as an illumination column.

  FIG. 8 is a longitudinal sectional view showing an example of a vibration damping device disclosed in Patent Document 2. As shown in FIG. This vibration damping device has a two-dimensional pendulum having a support arm 44 suspended in a case 41 so as to be rotatable in all horizontal two-dimensional directions, and a weight 42 fixed to the lower end thereof. Consists of. This device is installed at the upper end of a vertically erected member such as an illuminating column, and its vibration control mechanism is as follows.

  That is, when vibration due to lateral shaking is applied to a vertical standing member such as a lighting column due to the passing of a vehicle or the like, the weight 2 moves in a direction to suppress this vibration, and one end of the wire 49 is pulled in that direction. It is done. Since the other end of the wire 49 is connected to the damping mechanism 50 including the liquid shock absorber 48 and the spring mechanism 49 via the guide hole between the two pulleys 46, the damping mechanism 50 is displaced when the wire 49 is pulled. Let At this time, the liquid shock absorber 48 in the damping mechanism 50 urges the damping force to attenuate the pendulum movement of the weight 2, so that the vibration of the vertical standing member is also attenuated.

Japanese Patent Publication No. 04-26004 JP 09-264378 A

  However, all of the conventional vibration control devices described above exhibit effective vibration suppression effects against vibration caused by lateral shaking of vertical standing members such as lighting columns. However, they are limited to structures such as road bridges and pedestrian bridges. The vertical vibrations that are generated have no damping effect. Therefore, it was found that it was not possible to deal with vibrations caused by vertical shaking such as structures such as road bridges and footbridges.

  An object of the present invention is to provide a vibration damping device capable of attenuating vertical vibrations generated in structures such as road bridges and pedestrian bridges due to vibrations caused by wind, earthquakes, road vibrations caused by vehicle running and walking, Another object of the present invention is to provide a road bridge and a pedestrian bridge excellent in vibration control.

  The present inventors have obtained the following knowledge (a) to (e) as a result of repeating various experiments and studies in order to develop a device for attenuating vibration caused by vertical vibration generated in a structure.

  (A) When a spring is hung from the controlled body and a weight is attached to the lower end, the vertical vibration generated by the vertical vibration of the controlled body is amplified by the weight through the spring. It is transmitted, and the weight moves up and down.

  (B) When the suspension member is suspended from the weight, the suspension member also moves up and down in conjunction with the vertical movement of the weight every time vertical vibration is applied to the controlled body.

  (C) When the lower part of the suspension member is installed in contact with the upper surface of the structural member of the controlled body, the lower part of the suspension member is once lifted away from the upper surface of the structural member of the controlled body. Since it falls and collides with the upper surface of the structural member of the controlled body, the vibration energy caused by the shaking of the structural member of the controlled body can be dissipated.

  (D) The suspension member suspended from the weight may be suspended from one weight, but may be suspended in a suspended shape between the two weights.

  (E) If this vibration damping device is installed in the main girder or cross girder of a road bridge or pedestrian bridge, a great vibration damping effect can be obtained.

  The vibration damping device and the road bridge and footbridge excellent in vibration damping performance according to the present invention have been completed based on these findings, and the present invention includes the following vibration damping devices (1) to (4) and The main points are (5) the road bridge with excellent vibration control and (6) the footbridge with excellent vibration control.

  (1) A vibration damping device including a spring having a weight at a lower end and an upper part attached to a vibration-damped body and a suspension member suspended from the weight, wherein the lower part of the suspension member is A vibration damping device, wherein the vibration damping device is in contact with a top surface of a constituent member of the vibration-damped body.

  (2) A vibration damping device comprising a plurality of springs having a weight at the lower end and an upper part attached to the vibration-damped body, and a suspension member suspended in a suspended manner between these weights. A vibration damping device, wherein a central portion of the suspension member is in contact with an upper surface of a component member of the vibration control body.

  (3) The suspension member according to (1) or (2) above, wherein the suspension member is made of at least one of a combination of a plurality of metal bodies, a metal chain, and a metal wire. Damping device.

  (4) The vibration damping device according to (1) to (3) above, wherein the weight has a connecting arm for connecting the suspension member.

  (5) A road bridge excellent in vibration damping, characterized in that the vibration damping devices (1) to (4) are attached to a main beam or a horizontal beam.

  (6) A pedestrian bridge excellent in vibration damping characteristics, wherein the vibration damping device of (1) to (4) is attached to a main girder or a horizontal girder.

  The vibration damping device according to the present invention exerts a large vibration damping effect against vibration caused by vertical vibration generated in structures such as road bridges and footbridges, and prevents metal fatigue of structural members. it can.

  In addition, since the structure is simple, the manufacturing cost is low and the construction is easy, and it is possible to secure comfortable traffic and safety by attaching to a road bridge or a footbridge.

  Hereinafter, a vibration control device according to the present invention, and a road bridge and a footbridge excellent in vibration control performance will be described with reference to the drawings.

  FIG. 1 is a front view showing an example of a vibration damping device according to the present invention.

  The vibration damping device according to the present invention includes a spring 13 having a weight 14 at a lower end, and a hanging portion 15 suspended from the weight 14. The upper end of the spring 13 is attached to the upper cross member 5 of the vibration controlled body via a connecting wire 18 and a hook 17. A single suspension member 15 is suspended from the weight 14 via a connecting arm 16, and the length L of the lower portion of the suspension member is the upper surface of the lower cross member 6 of the vibration control body. Touching.

  FIG. 2 is a front view showing another example of the vibration damping device according to the present invention.

  The vibration damping device according to the present invention includes a spring 13 having a weight 14 at its lower end and a hanging portion 15 suspended from the weight 14, and the upper end of the spring 13 is connected via a connecting wire 18 and a hook 17. Although it is the same as that of the vibration damping device shown in FIG. 1 in that the vibration damping body is attached to the upper cross member 5, two suspension members 15 are suspended from the weight 14 via the connecting arm 16. It is. The length L of the lower part of the suspension member is in contact with the upper surface of the lower cross member 6 of the controlled body.

  FIG. 3 is a front view showing another example of the vibration damping device according to the present invention.

  The vibration damping device according to the present invention includes two springs 13 each having a weight 14 at a lower end, and one suspension member 15 suspended in a suspended manner between the respective weights 14 of the spring. The upper ends of the two springs 13 are respectively attached to the upper cross member 5 of the vibration-damping body via a connecting wire 18 and a hook 17. Then, one suspension member 15 is suspended in a suspended shape via coupling arms 16 at both ends so as to connect these two weights 14, and the length L of the central portion of the suspension member Is in contact with the upper surface of the lower cross member 6 of the vibration-damped body.

  By adopting the above-described configuration, the vibration damping device according to the present invention prevents vertical vibration generated in the vibration-damped body due to wind, earthquake, vehicle running, road vibration caused by walking, and the like. The weight is transmitted to the weight attached to the lower end of the spring via the spring attached to the damping body, and the weight moves up and down. This amplified vertical movement is transmitted to the suspension member via a connecting arm attached to the weight, and the suspension member also moves up and down in conjunction with the vertical movement of the weight.

  When the suspension member is installed in a state where the lower part of the suspension member is in contact with the upper surface of the component member of the controlled body, the lower part of the suspension member is once lifted away from the upper surface of the component member of the controlled body, Since it falls and collides with the upper surface of the structural member of a vibration body, the vibration energy resulting from the shaking of the structural member of a to-be-damped body can be dissipated.

  Thus, by repeating the collision by the vertical movement of the suspending member, the vibration in the vertical direction of the controlled body is dissipated and attenuated.

  Hereinafter, each component of the vibration damping device according to the present invention will be described in detail.

(1) Spring A coil spring is suitable as the spring. When a plurality of springs are used in one device, it is preferable to use springs having the same spring constant so that the vibrations of the springs are uniform. Although the specifications of the spring are not limited, it is necessary to decide what kind of spring to use depending on the size of the vibration-damped body and the weight of the weight to be used. A spring may be designed to amplify the vibration generated in the vibration-damped body and transmit it to the weight and the suspension member.

(2) Weight The material of the weight is not particularly limited, but a material having a high density such as steel is preferable. The appropriate value of the weight of the weight is affected by the size of the damping body, the specifications of the spring used, the weight of the suspension member, and the like. What is necessary is to design the weight so that the vibration generated in the vibration-damped body is converted into a vertical movement of the weight and transmitted to the suspension member. The shape is not particularly limited.

(3) Suspension member It is preferable to use at least one of a suspension member, a metal chain, a metal chain, and a metal wire. Since this member needs to follow the movement of the weight, it may be a flexible member.

  As the metal chain, it is preferable to use a steel chain having a chain diameter of 6 to 25 mm, a link size of 30 to 125 mm, a width of 21 to 88 mm, a total length of 80 to 220 cm, and a total weight of 600 to 31000 g. A steel chain is preferable from the viewpoint of strength and durability. From the viewpoint of rust prevention, it is preferable to use a stainless steel chain or to use a steel chain subjected to rust prevention treatment such as hot dip galvanization.

  A combination of a plurality of metal bodies is preferably a combination of spherical metal bodies, but the shape is not particularly limited and may be a rectangular parallelepiped. In order to connect the metal bodies together, a hook may be provided on the metal bodies by welding or screws, and the metal bodies may be connected by a wire or a chain. For example, 5 to 61 metal balls having a diameter of 21 to 99 mm may be connected by a steel wire having a length of 15 to 74 mm and an outer diameter of 2 to 6 to 9 mm. As a material for the metal sphere, stainless steel or aluminum is used in addition to steel. A preferable suspension member having a large damping effect is a metal chain and a steel ball connected by a wire. In addition, since the suspension member repeatedly collides with the inner surface of the hollow body and generates a loud collision sound, it is preferable to coat the outer surface with rubber or the like when it is desired to suppress the collision sound.

  In addition, when the suspension member is suspended in a suspended shape by connecting a plurality of weights 14, there is no possibility that the suspension member is detached from the vibration control body. When suspended from a single weight, in order to prevent the suspension member from being detached from the controlled body, it is preferable that a part of the suspended member is fixed to the controlled body. . Of course, even when the suspension member is suspended in a suspended shape by connecting a plurality of weights 14, it is important to fix a part of the suspension member to the vibration control body. I do not care.

  A part of the suspension member is brought into contact with the vibration control body when the suspension member moves up and down in conjunction with the vertical movement of the weight. This is for the purpose of causing the vibration to be dropped on the upper surface of the component of the vibration-damped body after being lifted away from it, and by the collision at this time, the vibration energy in the vertical direction of the vibration-damped body is dissipated, and the vibration damping effect It can be expressed. Therefore, it is necessary for the suspension member to come into contact with the upper surface of the constituent member of the vibration control body.

The lower part of the suspension member is in contact with the upper surface of the lower cross member 6 of the vibration-damped body by a length L. The length L of the contact portion is appropriately determined according to the vibration mode of the vibration-damped body. You only have to set it.
(4) Connecting means for members constituting the vibration damping device FIG. 4 shows connecting portions of the members constituting the vibration damping device. (A) is a hook periphery for attaching a spring to a vibration-damped body, (b) is both ends of the spring, and (c) is a longitudinal sectional view of a weight.

  One end of the hook 17 is passed from below through the through hole 28 provided in the upper cross member 5 of the vibration control body, and the end thereof is fixed to the upper cross member 5 of the vibration control body by a nut 19. A connecting wire 18 is hung on the hook 17. The upper and lower ends of the connecting wire 18 are ring-shaped, and are hooked on the hook 17 and the hook 20a provided at the upper end of the spring, respectively. A fitting 21 having a ring-shaped tip is screwed onto the weight 14 and hung on a hook 20b provided at the lower end of the spring.

  Next to the weight 14, a connecting arm 16 is screwed in the horizontal direction. The tip of the connecting arm is a ring, and the end of the suspension member is connected to the ring.

  Although the connecting arm can be omitted and the suspension member can be directly screwed onto the weight, etc., if the connection arm is used, the suspension member can rotate freely around the weight. It is preferable to use an arm.

  The connecting means of each member is not limited to the above means, and any means may be used as long as it is easy to attach and the connecting portion does not come off even if the spring vibrates.

  Note that the wire 18 that connects the hook 17 installed on the upper cross member of the vibration-damping member and the hook 20 at the end of the spring 13 is not necessarily used. The hook 17 and the hook 20 a may be directly connected without using the 18.

(5) Structure as a vibration-damped body Typical structures for mounting the vibration damping device according to the present invention are a road bridge and a footbridge.

  FIG. 5 is a perspective view showing an example of a pedestrian bridge to which the vibration damping device according to the present invention shown in FIG. 3 is attached.

  The footbridge has a main girder 24 and a horizontal girder 25 on both sides of the floor board 22. Here, in the vibration damping device according to the present invention, a plurality of vibration damping devices 1 are attached to the side surface of the main girder 24 in the length direction of the pedestrian bridge. Here, the vibration damping device 1 is attached only to the side surface of the main beam 24, and is not attached to the horizontal beam 25. This is because the main girder 24 has sufficient space for mounting the vibration damping device 1 and it is efficient to damp the main girder 24. If there is enough space to attach to the cross beam 25 and further a damping effect is required, it is preferable to attach to the cross beam 25 as well.

  FIG. 6 shows an example of a road bridge to which the vibration damping device according to the present invention shown in FIG. 3 is attached. (a) is a perspective view, (b) is an enlarged view of the main girder part.

  The road bridge is supported by a main girder 24 and a horizontal girder (not shown) with a floor plate 22 below. Here, in the vibration damping device according to the present invention, a plurality of vibration damping devices 1 are attached to the side surface of the main girder 24 in the length direction of the road bridge. In addition, it is preferable to install a vibration control device also in the cross beam (not shown).

  The vibration damping device can be easily tuned by adjusting the spring constant and the contact length L of the vibration energy dissipation member with the vibration-damped material. In addition, this vibration control device can be installed at the new stage of structures such as road bridges and pedestrian bridges, as well as retrofit to existing road bridges and pedestrian bridges where vibration control performance has become a problem. There is an advantage of being.

  According to the vibration damping device of the present invention, it is possible to exert a large vibration damping effect against vibration caused by vertical vibration generated in a structure such as a road bridge or a footbridge, and prevent metal fatigue of structural members. By attaching the vibration damping device according to the present invention to a structure such as a road bridge or a pedestrian bridge, comfortable traffic and safety can be ensured.

It is a front view which shows an example of the damping device concerning this invention. It is a front view which shows the other example of the damping device concerning this invention. It is a front view which shows the other example of the damping device concerning this invention. The connection part of each member which comprises a damping device is shown. (A) is a hook periphery for attaching a spring to a vibration-damped body, (b) is both ends of the spring, and (c) is a longitudinal sectional view of a weight. It is a perspective view which shows an example of the footbridge which attaches the damping device concerning this invention. An example of the road bridge which attaches the damping device concerning this invention is shown. (a) is a perspective view, (b) is an enlarged view of the main girder part. It is gun sectional drawing of the conventional damping device. It is sectional drawing of the conventional damping device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Damping device 4 Damping body 5 Upper cross member of a controlled body 6 Lower cross member of a controlled body
13 Spring
14 weights
15 Suspension member
16 articulated arm
17 hook
18 Connecting wire
19 Nut
20a, 20b hook
21 Mounting bracket
22 Floor board
24 main digits
25 Horizontal girder
27 Fastener
28 Through hole
29 chain
30 End plate
31 Fixed hook
32 Vertical hollow body
41 cases
42 weight
44 Support arm
46 pulley
47 wire
48 Dashpot
49 Spring mechanism
50 Damping mechanism

Claims (6)

  A vibration damping device comprising a spring having a weight at the lower end and an upper part attached to the vibration-damped body and a suspension member suspended from the weight, wherein the lower part of the suspension member is A vibration damping device that contacts an upper surface of a body component.   A damping device comprising a plurality of springs having a weight at a lower end and an upper part attached to a vibration-damped body, and a suspension member suspended in a suspended manner between these weights, A vibration damping device, wherein a central portion of a suspension member is in contact with an upper surface of a constituent member of a vibration-damped body.   The vibration damping device according to claim 1 or 2, wherein the suspension member is made of at least one of a combination of a plurality of metal bodies, a metal chain, and a metal wire.   4. The vibration damping device according to claim 1, wherein the weight has a connecting arm for connecting the suspension member.   A road bridge excellent in vibration damping, wherein the vibration damping device according to any one of claims 1 to 4 is attached to a main beam or a horizontal beam.   A footbridge excellent in vibration damping, wherein the vibration damping device according to any one of claims 1 to 4 is attached to a main girder or a horizontal girder.

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