JP3052992B2 - Cable-stayed bridge anti-vibration structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration structure for a cable-stayed bridge, and more particularly to an anti-vibration structure for a cable-stayed bridge for preventing vibration of a suspension wire and preventing vibration of a bridge body.

[0002]

2. Description of the Related Art As is well known, a cable stayed bridge is shown in FIG.
To be more specific, the main post P, a suspension wire W whose base end is connected to the main post P, and a bridge body B connected to the distal end of the suspension wire W, In recent years, it has tended to be longer than conventional ones,
Therefore, the hanging wire W also tends to be longer.

[0003] The lengthening of the suspension wire W leads to the fact that the so-called fulcrum becomes longer, which makes it easier to vibrate the suspension wire W. When the vibration of the suspension wire W is neglected, the bridge body B Is vibrated, and as a result, the durability of the bridge body B is unnecessarily reduced.

[0004] Therefore, in a recent cable stayed bridge in which the suspension wire W is lengthened, it is urgently necessary to prevent the vibration of the bridge body B due to the vibration of the suspension wire W. At present, there has been no proposal for a typical anti-vibration structure, that is, an anti-vibration structure for a cable-stayed bridge.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a cable-stayed bridge having a suspension wire installed between a main post and a bridge body. An object of the present invention is to provide an anti-vibration structure for a cable-stayed bridge which is optimal for maintaining predetermined durability of a bridge body by preventing vibration of a suspension wire itself.

[0006]

In order to achieve the above object, the present invention provides a suspension wire having a base connected to a main post, a bridge body connected to a distal end of the suspension wire, and a suspension. A cable-stayed bridge having a damper disposed between the wire and the bridge body, one end of the damper connected to a portion near the tip of the suspension wire, and the other end of the damper connected to the bridge body. In the vibration damping structure of (1), the damper has an expansion-side pressure regulating valve and a compression-side pressure regulating valve in the piston portion that slides in the cylinder while partitioning the extension-side oil chamber and the compression-side oil chamber. The base valve section that separates the reservoir chamber of the cylinder has a growth-side check valve and a compression-side check valve, and the piston speed is extremely low in the low-speed range between the expansion-side oil chamber in the cylinder and the reservoir chamber outside the cylinder. Predetermined damping action when side operation And it is characterized in that comprising a orifice.

[0007]

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on the illustrated embodiment. The vibration-isolating structure of a cable-stayed bridge according to the present invention is schematically shown in FIG. In addition, a damper D is arranged on the cable stayed bridge.

That is, the cable stayed bridge is connected to the main post P, the suspension wire W to which the base end which is the upper end is connected to the main post P, and the distal end which is the lower end of the suspension wire W as described above. In the illustrated example, one main post P is erected at the so-called center, and a plurality of suspension wires W extend from the so-called left and right sides of the main post P. The bridge body B is connected to a plurality of suspension wires W.

In the illustrated example, the tip of the hanging wire W is integrally connected to the bridge body B (see FIG. 1) under the presence of a stopper W1 such as a plug, as shown in FIG. I have.

The bridge body B may be continuous, or both ends may be connected to a fixed side such as a so-called ground.

The damper D has one end connected to the vicinity of the tip of the suspension wire W and the other end connected to the bridge body B.
In the illustrated example, as shown in FIG. 2, the connecting tool W2 on the suspension wire W side and the connecting tool B1 on the bridge body B side are connected to each other.

At this time, the connection state between the damper D and the suspension wire W is set such that the axis of the damper D is perpendicular to the axis of the suspension wire W. When the vibration of W is in a direction of being farther or farther from the damper D, the damper D can exhibit an effective damping action.

In the illustrated example, the connecting tool W2 on the hanging wire W side is formed in a so-called two-piece specification, and the damper D disposed at the corresponding portion is set so as to use a so-called two piece. (See FIG. 2).

In the case where two dampers D are used as shown in the drawing, it is preferable in that the suspension wire W can be prevented from vibrating in the so-called horizontal direction. In order to mainly prevent the swing of the suspension wire W from vibrating in the vertical direction with respect to the bridge main body B, the damper D may be set to use a single damper.

By the way, it is sufficient that the damper D has a predetermined damping action when it expands and contracts. In the present invention, the damper D is configured as follows.

That is, as shown in FIG.
It has a cylinder 1 and a piston rod 2 which is inserted into the cylinder 1 so that a distal end side, which is a lower end side in the drawing, can protrude and retract, and is provided continuously with a base end, which is an upper end in the drawing, of the piston rod 2. Of the hanging wire W through the eye 21
2 is connected.

The damper D is slidably housed in the cylinder 1 and defines an extension oil chamber U and a compression oil chamber L in the cylinder 1 and a lower end of the piston rod 2 in the drawing. And a piston portion 3 continuously provided at the tip of

The piston portion 3 includes a piston body 31 which substantially partitions the inside of the cylinder 1 into an extension oil chamber U and a compression oil chamber L.
And a communication between the expansion-side oil chamber U and the compression-side oil chamber L is enabled via the expansion-side pressure adjustment valve 32 and the compression-side pressure adjustment valve 33. .

The expansion side pressure regulating valve 32 and the compression side pressure regulating valve 33
Are poppets 32a and 33a, respectively, in the illustrated example.
Are biased by springs 32b and 33b from the rear side so as to close a so-called flow path when moving forward, so to speak, a relief valve.

On the other hand, the damper D is formed in a so-called double cylinder type having an outer cylinder 4 disposed outside the cylinder 1 and having a reservoir chamber R between the outer cylinder 4 and the cylinder 1. It is described that the outer tube 4 is connected to the connecting member B1 on the bridge body B via an eye 51 formed on a bottom member 5 provided continuously to the bottom end, which is the lower end of the outer cylinder 4.

The outer cylinder 4 has its upper open end closed with a bearing member 6 together with the upper open end of the cylinder 1, and the piston rod 2 is slidable on the axis of the bearing member 6. Through the bearing member 6
Is formed with an oil passage 61 that allows the extension-side oil chamber U to communicate with the reservoir chamber R.

In the present invention, the oil passage 61
It is assumed that an orifice having a predetermined damping action is arranged at the time of extension operation in a very low speed range of the piston speed,
In the illustrated example, the orifice is made up of a pore 62a of a plug 62 screwed to the end face of the bearing member 6 on the side of the extension oil chamber U.

The reservoir chamber R has a gas chamber G bordering the oil level O, and is provided with a base valve portion 7 serving as a partition member disposed at the lower end of the cylinder 1 so as to provide a pressure side oil chamber L in the cylinder 1. It is sectioned.

A pipe 8 having a lower end opening in oil is disposed in the reservoir chamber R, and an upper end of the pipe 8 is connected to an outer peripheral end of the bearing member 6. The inside is set so as to communicate with the oil passage 61.

The base valve portion 7 includes a valve body 71 serving as a partition member and the bottom member 5 and the cylinder 1.
The valve body 71 has an expansion-side check valve 72 for preventing oil in the reservoir chamber R from flowing into the compression-side oil chamber L, and an oil in the compression-side oil chamber L. Check valve 73 for preventing gas from flowing into the reservoir chamber R
Are provided, and communication between the pressure side oil chamber L and the reservoir chamber R via the expansion side check valve 72 and the pressure side check valve 73 is enabled.

Therefore, in the above-described damper D, when the piston rod 2 is compressed into the cylinder 1 during the compression operation,
The pressure in the compression-side oil chamber L rises due to the lowering of the piston portion 3 in the cylinder 1, and oil from the compression-side oil chamber L flows into the expansion-side oil chamber U via the compression-side pressure regulating valve 33, and the compression-side oil chamber L
The oil corresponding to the invading volume of the piston rod 2 flows out into the reservoir chamber R via the extension side check valve 72 in the base valve portion 7.

At this time, a pressure difference is generated between the compression-side oil chamber L and the expansion-side oil chamber U, and this acts as a compression-side damping force in the damper D.

On the other hand, during the extension operation in which the piston rod 2 protrudes from the inside of the cylinder 1, the pressure in the extension-side oil chamber U increases due to the rise of the piston portion 3 in the cylinder 1, and the oil from the extension-side oil chamber U Flows out to the reservoir chamber R through the orifice formed by the fine holes 62a, and flows out to the pressure side oil chamber L through the expansion side pressure regulating valve 32.

At this time, a pressure difference is generated between the expansion-side oil chamber U and the compression-side oil chamber L, and this acts as the expansion-side damping force of the damper D.

At this time, the oil equivalent to the rejected volume of the piston rod 2 that is insufficient in the pressure side oil chamber L is supplied from the reservoir chamber R via the pressure side check valve 73.

In the configuration having the damper D formed as described above, that is, one end of the damper D is connected to the vicinity of the tip of the suspension wire W, and the other end is connected to the bridge body B. Since the damper D can be connected in a direction orthogonal to the suspension wire W, when the suspension wire W vibrates with respect to the bridge body B, the vibration is suppressed by the damper D when the suspension wire W expands and contracts, that is, Acts as a deterrent.

When the damper D is set so that the damping force on the extension side and the damping force on the compression side are the same, the suspension of the suspension wire W can be more effectively prevented.

When the dampers D are connected to the suspension wires W in a so-called two-use manner, vibration of the suspension wires W in the lateral direction can be prevented.

[0035]

The damper according to the present invention has an expansion-side pressure regulating valve and a compression-side pressure regulating valve in the piston portion, and an orifice between the expansion-side oil chamber and the reservoir for damping when the expansion-side operation is performed. Therefore, the extension side damping force is generated between the expansion side pressure regulating valve and the orifice during the extension operation, and the compression side pressure regulating valve generates the compression side damping force during the compression side operation. Therefore, according to the vibration isolation structure of the cable-stayed bridge of the present invention having the damper, the vicinity of the distal end of the suspension wire whose base end is connected to the main post, the bridge body connected to the distal end of the suspension wire, Since the damper is disposed between the damper and the damper, it is possible to connect the axis of the damper in a state perpendicular to the axis of the suspension wire, and therefore, the vibration of the suspension wire is in a direction of moving toward and away from the damper. At this time, an effective damping action by the damper, that is, vibration of the suspension wire can be effectively prevented.

In the case where two dampers are used as in the illustrated example, lateral vibration of the suspension wire can be effectively prevented.

Further, when the damper is set to have the same damping force on the extension side and the damping force on the compression side, vibration of the suspension wire can be more effectively prevented.

As a result, according to the present invention, in a cable-stayed bridge having a suspension wire mounted between the main post and the bridge body, vibration of the suspension wire itself is prevented to prevent vibration in the bridge body. This is optimal for preventing the predetermined durability of the bridge body from being unnecessarily reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing in principle a vibration isolation structure of a cable-stayed bridge according to the present invention.

FIG. 2 is a perspective view showing a state in which a damper is connected to a portion near a tip end of a suspension wire.

FIG. 3 is a longitudinal sectional view showing a damper in which upper and lower ends are partially broken.

[Description of Signs] 1 cylinder 3 piston part 7 base valve part 32 expansion side pressure regulator 33 compression side pressure regulator 62a pore forming orifice 72 expansion side check valve 73 pressure side check valve B bridge body D damper L pressure side oil chamber P main Post R Reservoir chamber U Extension oil chamber W Suspension wire

Continuation of front page (72) Inventor Hiroharu Mukai 2-9-1-1, Tobita-shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (56) References JP-A-3-110207 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) E01D 1/00 E01D 11/00

Claims (1)

(57) [Claims] 1. A suspension wire having a base connected to a main post, a bridge body connected to a tip of the suspension wire, and a damper disposed between the suspension wire and the bridge body. In a vibration-isolating structure of a cable-stayed bridge in which one end of a damper is connected to a portion near a tip end of a suspension wire and the other end of the damper is connected to a bridge body, the damper divides an extension-side oil chamber and a compression-side oil chamber. The piston part which slides inside the cylinder while having the expansion side pressure regulating valve and the compression side pressure regulating valve, and the expansion side check valve and the pressure side check are provided in the base valve part which separates the compression side oil chamber in the cylinder and the reservoir chamber outside the cylinder. Having a valve, and
A cable-stayed bridge prevention device comprising an orifice having a predetermined damping function when the piston extends in a very low speed range of a piston speed, between an extension-side oil chamber in the cylinder and a reservoir chamber outside the cylinder. Swing structure.