JP2008082452A - 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 member comprised by serially connecting a plurality of springs 6 via at least one weight 11, and a vertical hollow body 7 comprised by suspending a suspension member suspended from the weight in an interior such that it has a free vibration portion. The damping device is characterized by that both ends of the spring member and the vertical hollow body are respectively fixed so that the spring member is obliquely installed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is excellent in vibration damping devices for damping vibrations generated in structures such as road bridges and pedestrian bridges due to passage of vehicles, earthquakes, and the like, and vibration damping properties provided with such vibration damping devices. It relates to road bridges and footbridges.

  Structures such as road bridges and pedestrian bridges may sway due to resonance phenomena caused by wind, earthquakes, vehicle traffic, and road vibrations associated with walking. 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 a metal wire is hung by giving a free vibration part 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 damping device, and this vibration damping device is attached to the outside or 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 is composed of a vertical hollow body 33 made of a circular steel pipe and a suspension member of a steel chain 34 suspended therein. The upper end of the steel chain 34 is supported by a fixing hook 36 fixedly attached to an end plate 35 installed on the upper part of the vertical hollow body 33. Therefore, the steel chain 34 forms a free vibration part except for the upper end.

  Here, since the steel chain 34 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 34 and the inner wall of the vertical hollow body 33 is a circular steel pipe. Is kept equivalent inside.

  This vibration control device receives vibrations caused by a resonance phenomenon caused by wind, earthquake, road surface vibration caused by vehicle traffic or walking, etc., and excitation occurs. At that time, both the vertical hollow body 33 and the steel chain 34 vibrate, but the free vibration part of the steel chain 34 vibrates in a different manner from the vertical hollow body 33, so the free vibration part of the steel chain 34 is It collides with the inner wall surface of the vertical hollow body 33. As a result, the vibration energy of the vertical hollow body 33 is dissipated, so that the vibration of the vertical hollow body 33 is rapidly attenuated and the vibration is stopped.

  In this way, by suspending the steel chain 34 inside the vertical hollow body 33, 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 is a two-dimensional pendulum having a support arm 23 suspended in a case 20 so as to be rotatable in all horizontal two-dimensional directions, and a weight 21 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 a vibration due to a lateral swing is applied to a vertical standing member such as a lighting column due to the passing of a vehicle or the like, the weight 21 moves in a direction to suppress the vibration, and one end of the wire 19 is pulled in that direction. It is done. Since the other end of the wire 19 is connected to a damping mechanism 26 including a liquid buffer 27 and a spring mechanism 28 via a guide hole between the two pulleys 25, the damping mechanism 26 is displaced when the wire 19 is pulled. Let At this time, the liquid shock absorber 27 in the damping mechanism 26 urges the damping force to attenuate the pendulum movement of the weight 21, 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 pedestrian bridges.

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

  The present inventors conducted various experiments in order to develop a vibration damping device capable of attenuating longitudinal vibration generated in structures such as road bridges and footbridges. As a result, the following findings (a) to (c) were obtained.

  (A) Longitudinal vibrations generated in the structure are generated in the structure so that the spring members are slanted at both ends of the spring member formed by connecting the weights between the springs in series. If fixed, the vibration in the vertical direction of the structure is transmitted to the weight via the spring, and the vibration direction of the weight is inclined due to the tension of the spring. Therefore, not only the vertical direction component but also the horizontal direction component is generated as the vibration direction component of the weight.

  (B) At this time, if a suspension member having a free vibration part is suspended from the weight, it also starts to vibrate in the horizontal direction.

  (C) Then, if the vertical hollow body is fixed to the structure and a hanging member suspended from the weight is inserted into the vertical hollow body, the hanging member vibrates in the horizontal direction. Since it has the free vibration part which can do, it can damp the vibration of the structure which collides with the inner wall of the vertical hollow body and shakes in the vertical direction.

  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 vertical member in which a spring member in which a plurality of springs are connected in series via at least one weight and a suspension member suspended from the weight have a free vibration part. A vibration damping device comprising a hollow body, wherein both ends of the spring member and the vertical hollow body are fixed so that the spring member is installed obliquely.

  (2) The vibration damping device according to (1), 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.

  (3) The vibration damping device according to (1) or (2), wherein the hollow body is a metal tube.

(4) The damping device according to (1) to (3) above, wherein the inclination angle θ of the spring member with respect to the horizontal direction is about 30 to 60 ° .

  (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 shaking generated in a structure such as a road bridge or a footbridge, 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 weight 11, a spring member in which two springs 6 are connected in series via the weight 11, a suspension member 9 suspended from the weight 11, and a suspension. It consists of a vertical hollow body 7 in which a member 9 is inserted. The suspension member 9 is suspended so as to have a free vibration part inside the vertical hollow body 7, and both ends of the spring member are connected in a state where the spring member has an inclination angle θ = 45 ° with respect to the horizontal direction. It is fixed to the side surface of the structure 13 by a stopper 12 via a wire 18 and a stopper hook 14. Further, the vertical hollow body 7 is fixed to the side surface of the structure 13 by the attachment band 8.

  Hereinafter, each component of the present invention will be described in detail.

(1) Spring member The spring member is formed by connecting a plurality of springs in series via at least one weight. In the example shown in FIG. 1, a weight 11 is interposed between two coil springs 6, and the weight 11 and the coil spring 6 are connected by a connecting wire 10. Here, both ends of the spring member are fixed to the stopper 12 via the connecting wire 18 and the hook 14, but the connecting wire 18 and the hook 14 may be omitted. Therefore, both ends of the spring member may be directly attached to the clasp 12 or the hook 14.

  The connection means of the weight and the spring is not particularly limited, but is preferably one that can be easily attached and detached and cannot be easily detached after connection. For example, it is preferable that the tip of the spring is processed into a hook shape, hooks having threaded portions are attached to the weight, and connecting wires are connected to these hooks.

  FIG. 2 is an example of the ends of the weight 11 and the spring 6 constituting the spring member according to the present invention.

  FIG. 2A is an enlarged sectional view of the weight. It is shown that the hook 16 for spring connection is fixed to the weight 11 by screwing. The hook 15 is a hook for the suspension member.

  FIG. 2B is a partially enlarged view of the end portion of the coil spring. The end 17 of the coil spring 6 is processed into a hook shape.

  It is necessary to install the spring member so as to be inclined. The reason is as follows.

  That is, vibration due to vertical shaking of the structure is transmitted to the weight via the spring, and the weight starts to vibrate in the vertical direction. Since the weight is connected by a spring inclined at an angle θ with respect to the horizontal direction, vibration in the angle θ direction is applied to the weight by the expansion and contraction movement of the spring. Accordingly, since the vibration of the weight includes a horizontal component, the vibration of the suspension member suspended from the weight includes a horizontal component in addition to the vertical component.

  The reason why the spring member is installed obliquely is to change the vibration caused by the vertical shaking of the structure into the horizontal vibration of the suspension member via the spring and the weight.

  The inclination angle θ of the spring member is preferably about 30 to 60 °. If the tilt angle is less than 30 °, the vibration in the vertical direction of the non-damping body cannot be sufficiently converted into the vibration including the horizontal component of the weight, and the apparatus becomes large. In addition, when the inclination angle exceeds 60 °, the vibration in the vertical direction of the non-damping body cannot be sufficiently converted into the vibration including the horizontal component of the weight.

  Note that the connecting wire 10 for connecting the weight and the spring and the connecting wire 18 for connecting the end of the spring member and the hook do not necessarily need to be used. If the installation place of the damping device is narrow, the end of the coil spring 6 is used. 17 may be directly connected to the hook 16 or the clasp 12 of the weight 11.

  Although FIG. 1 shows an example of a spring member using two coil springs and one weight, the number of weights and coil springs may be increased. For example, a spring member in which one or two weights are interposed between the coil springs using three coil springs may be used. The coil spring may be normally used, and it is preferable to use a coil spring having the same elasticity in order to evenly vibrate the vibration of the suspension member in the θ direction.

  The shape and material of the weight are not particularly limited, but a metal ball is preferable because a weight that matches the elasticity of the spring can be used. The weight of the weight depends on the strength of the spring used. As a guide, the weight should be such that the spring expands and contracts due to the swing of the weight.

(2) Vertical hollow body The vertical hollow body is fixed so that the suspension member suspended from the weight has a free vibration part. This is because the free vibration portion of the suspension member is vibrated in the horizontal direction and is caused to collide with the inner wall of the vertical hollow body to attenuate the vibration.

  The reason why the vertical hollow body is fixed vertically is to make the vibration in the horizontal direction of the suspension member uniform in all directions in the vertical hollow body. By equalizing, the vibration control effect is improved for all directions of vibration.

  That is, if the distance from the suspended suspension member to the inner surface of the hollow body is uniform in all directions, the damping effect is uniform in all directions. Therefore, the cross-sectional shape of the vertical hollow body is preferably a circular cross section, but may be a polygonal cross section such as an octagon or a hexagon.

  The vertical hollow body has an outer diameter of 34.0 to 114.3 mm, an inner diameter of 27.6 to 107.3 mm, a wall thickness of 2.3 to 4.5 mm, a length of 1.0 to 2.4 m, and a weight of 1.8. ~ 29 kg can be used.

  And as a material of a vertical hollow body, metal pipes, such as a stainless steel pipe and an aluminum pipe other than a steel pipe, can be used. A steel pipe is preferable from the viewpoint of strength and durability. From the viewpoint of rust prevention, it is preferable to use a stainless steel pipe or to use the steel pipe after subjecting the steel pipe to a rust prevention treatment such as hot dip galvanization or painting.

  In order to reduce the collision noise of the suspension member, the inner surface of the vertical hollow body is preferably covered with a resin or the like.

  The vertical hollow body is preferably fixed to the side surface of the structure so that the suspension member is located at the center of the cross section of the hollow body.

  3A and 3B are diagrams showing a state in which the vertical hollow body according to the present invention is attached to the side surface of the structure, where FIG. 3A is a side view, and FIG. 3B is a cross-sectional view taken along line AA in FIG. It is.

  The vertical hollow body 7 is vertically attached to the side surface of the structure 13 below the weight 11. Although the attachment method is not limited, for example, as shown in FIG. 3, it is preferable that two places on the outer surface of the vertical hollow body are wound in the horizontal direction by a metal belt 8 and then fixed with bolts 29. In addition, you may attach by welding instead of fixing with a volt | bolt.

(3) Suspension member As the suspension member, any one of a metal chain, a metal chain, and a metal wire may be used.

  FIG. 4 shows a state in which the suspension member is suspended inside the vertical hollow body 7. (A) is a longitudinal cross-sectional view when the suspension member is a metal chain 30, and (b) is a longitudinal cross-sectional view when the suspension member is a metal member 31 connected by a wire.

  As the hanging member of (a), 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 × 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.

  The metal body used for the hanging member shown in (b) is spherical, 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.

(4) Structures Typical structures for mounting the vibration damping device according to the present invention are road bridges and pedestrian bridges.

  FIG. 5 is a perspective view showing an example of a footbridge to which the vibration damping device according to the present invention shown in FIG. 1 is attached.

  The pedestrian bridge has a main girder 2 and a horizontal girder 3 on both sides of the floor board 1. Here, the vibration damping device according to the present invention has a plurality of vibration damping devices 4 attached to the side surface of the main girder 2 in the length direction of the footbridge. Here, the vibration damping device 4 is attached only to the side surface of the main beam 2 and is not attached to the horizontal beam 3. This is because the main girder 2 has sufficient space for mounting the vibration damping device 4 and it is efficient to damp the main girder 2. If there is enough space to attach to the cross beam 3 and further a damping effect is required, it is preferable to attach to the cross beam 3 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. 1 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 2 and a horizontal girder (not shown) in which a floor board 1 is located. Here, the vibration damping device according to the present invention has a plurality of vibration damping devices 4 attached to the side surface of the main beam 2 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).

  According to the vibration damping device according to the present invention, it is possible to exert a large vibration damping effect against vibration caused by vertical shaking generated in a structure such as a road bridge or a pedestrian bridge, 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 an example of the weight which comprises the spring member concerning this invention, and a spring edge part. (A) is the cross-sectional enlarged view of a weight, (b) is the elements on larger scale of the edge part of a spring. It is a figure which shows the state in which the vertical hollow body concerning this invention was attached to the side surface of a structure, (a) is a side view, (b) is sectional drawing in the AA of (a). It is a longitudinal cross-sectional view which shows the state which suspended the suspension member inside the vertical hollow body concerning this invention. (A) is a case of a metal chain, and (b) is a case where metal bodies are connected by a wire. An example of the footbridge which attaches the vibration damping device concerning this invention is shown. 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 a longitudinal cross-sectional view which shows an example of the conventional damping device. It is a longitudinal cross-sectional view which shows the other example of the conventional damping device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Floor board 2 Main girder 3 Horizontal girder 4 Damping device 6 Coil spring 7 Vertical hollow body 8 Belt 9 Hanging member
10 Connecting wire connecting weight and spring
11 spindles
12 Fastener
13 Structure
14 Hook for fastener
15 Weight hook to suspend the suspension member from the weight
16 Weight hook for connecting spring
17 Spring end
18 Connecting wire that connects the end of the spring member and the hook for the fastener
20 cases
21 weight
23 Support arm
24 Guide hole
25 pulley
26 Damping mechanism
27 Liquid buffer
28 Spring mechanism
29 volts
30 chain
31 Metal body
33 Vertical hollow body
34 Steel chain
35 End plate
36 Fixed hook d Distance between chain outer surface and inner wall of vertical hollow body

Claims (6)

  A spring member in which a plurality of springs are connected in series via at least one weight, and a vertical hollow body inserted therein so that a suspension member suspended from the weight has a free vibration part; A vibration damping device comprising: both ends of a spring member and a vertical hollow body fixed so that the spring member is installed obliquely.   2. The vibration damping device according to claim 1, wherein the suspension member is made of at least one of a plurality of metal bodies connected together, a metal chain, and a metal wire.   The vibration damping device according to claim 1, wherein the hollow body is a metal pipe.   4. The vibration damping device according to claim 1, wherein an inclination angle θ of the spring member with respect to the horizontal direction is 30 to 60 °. 5.   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.

Images