JP3027066B2 - Damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for attenuating vertical vibration and / or torsional vibration of a bridge being erected, for example.

[0002]

2. Description of the Related Art For example, as shown in FIG. 5, when a cable-stayed bridge is erected, bridge towers 1, 1 are erected at predetermined intervals, and then bridge beams 2, 1 , 2 are gradually extended in the horizontal direction, and a cable 3 is stretched between each of the bridge girders 2, 2 and each of the bridge towers 1, 1 to maintain the horizontal state of each of the bridge girders 2, 2. Finally, the bridge girders 2 and 2 facing each other are connected to each other. During this erection work, the bridge girders 2 and 2 vibrate up and down due to the working machine moving on them, wind pressure, etc. It is easy to torsionally vibrate around the center of the bridge girders 2 and 2.
Because it may cause resonance and is very dangerous,
Vibration dampers 4 and 4 are provided on bridge girders 2 and 2, respectively.

Conventionally, there is a vibration damping device 4 shown in FIG. This is because a pair of vibration generators 4a, 4a are provided on both side edges of the bridge girder 2 at equal intervals L from the center O of the bridge girder 2.
b, the actuators 6a, 6b of the two vibration generators 4a, 4b
6b causes the weights 7a, 7b to move up and down with the same phase and the same vibration force, and against the torsional vibration of the bridge girders 2, 2, the weights 7a, 7b are brought into opposite phase and the same It is moved up and down by the vibration force, and further, for the combined vibration of up and down and torsion of the bridge girder 2, each weight 7a,
By moving the bridge 7b up and down, the vibration of the bridge girder 2 is canceled.

[0004]

The above conventional vibration damping device requires two vibration generating devices 4a and 4b,
A control device for controlling the two vibration generating devices 4a and 4b separately and independently is required, and there is a disadvantage that the manufacturing cost is high.

The present invention has been made in consideration of the above-described conventional problems, and has as its object to provide a vibration damping device that can effectively attenuate vertical vibration and / or torsional vibration with a single vibration generator.

[0006]

To achieve the above object, the present invention provides a bridge girder that vibrates vertically and / or torsionally.
At a predetermined position in the upper width direction , a pair of supports are arranged at a required interval from each other, and a bridge girder is provided between the two supports.
A guide rail is installed along the width direction, and this guide rail is
The vibration generator is movably mounted on the
The movement of the raw device is movably fitted to the guide rail.
A base, a weight for generating vertical vibration, and the weight
And an actuator for raising and lowering the
On the base, a pini that meshes with the rack formed on the guide rail
On and the movement mode for rotating this pinion
A vertical vibration detector provided on the bridge girder
And for movement based on detection signals from torsional vibration detector
A control device for controlling the driving of the motor is provided.
You.

[0007]

In the above construction, the vibration frequency and the vibration force of the vertical vibration and the torsional vibration are determined by the vertical vibration detector and the torsional vibration detector including an accelerometer and a strain gauge provided at the center of the bridge girder and the side edges thereof. The vibration generator is detected and moved along the width direction on the bridge girder based on the detected value. In other words, for the vertical vibration of the bridge girder ,
It is located at the center of the bridge girder , and for torsional vibration of the bridge girder , the vibration generator is located at the side edge of the bridge girder. According to the strength of the torsional vibration, the vibration generating device is located at an appropriate position between the center and the side edge of the bridge girder .

[0008] Then, by controlling the vibration generator by the controller based on a detection signal from the vertical vibration detector and torsional vibration detector, attenuating the vibrations of the bridge girder in accordance with the vertical vibration and or torsional vibrations of the girder If the vibration in the direction in which the vibration is caused is generated, the vibration of the bridge girder can be continuously attenuated.

[0009]

An embodiment of the present invention will be described below. FIG. 1 shows a vibration damping device 4 provided on the bridge girder 2 during the above-described construction, in which a pair of support bases 10 and 10 are arranged on both side edges of the bridge girder 2 at equal intervals H from a width center O. And a guide rail 1 erected between the support bases 10, 10.
1, a vibration generator 12 is movably mounted.

As shown in FIGS. 2 and 3, the vibration generator 12 includes a linear bearing 13 on a guide rail 11.
And a weight 15 for generating vertical vibration, and an actuator 16 for moving the weight 15 up and down.

The moving base 14 has a pinion 17 provided at its lower portion engaged with a rack 18 formed on the lower surface of the guide rail 11 and the pinion 17 is moved by a moving motor 19.
By rotating in the forward and reverse directions, it is moved along the guide rail 11.

The weight 15 is fixed to a central portion of a weight support plate 21 which is vertically engaged with guide rods 20 erected at four corners of the movable base 14. The actuator 16 is driven to expand and contract by a liquid such as oil or a gas such as air. The main body 16a is fixed on the movable base 14, and the upper end of the expandable rod 16b is connected to the weight support plate. 21.

As shown in FIG. 1, a vertical vibration detector 22 composed of an accelerometer and a strain gauge and a pair of torsional vibration detectors 23 are disposed at the center and both sides of the bridge girder 2. As shown in FIG. 4, each of the detectors 22,
Based on the detection signal from 23.23, the control device 24 controls the moving motor 19 and the actuator 16. One of the two torsional vibration detectors 23 may be omitted. In FIG. 2, reference numeral 25 denotes a connecting plate for integrally connecting the upper ends of the guide rods 20, and an opening 26 for passing the weight 15 is formed in the center thereof. .

The operation principle of the vibration damping device 4 will be described.
The vertical vibration detector 22 and the torsional vibration detectors 23, 23 determine the vibration frequency and amplitude of the vertical and torsional vibrations,
That is, the vibration force is detected, and the control device 24 controls the movement motor 19 based on the detected value to move the vibration generation device 12 to a required position. That is, for vertical vibration of the bridge girder 2, the vibration generator 12 is positioned at the center of the bridge girder 2 as shown by the solid line in FIG. 1, and for torsional vibration of the bridge girder 2, FIG. As shown in the figure, the vibration generator 12 is located at the right edge or the left edge of the bridge girder 2. Further, with respect to the combined vertical and torsional vibration of the bridge girder 2, the vibration between the vertical vibration and the torsional vibration is reduced. Accordingly, the vibration generator 12 is located at an appropriate position between the central portion of the bridge girder 2 and the right or left edge.

Subsequently, the control device 24 controls the actuator 16 based on the detection signals from the detectors 22 and 23.23 to generate vibrations in a direction to attenuate vertical vibration and / or torsional vibration of the bridge girder 2. If you do, bridge girder 2
Can be continuously attenuated.

In the above-described embodiment, the guide rail 11 is installed over almost the entire width of the bridge girder 2. Instead, the guide rail 11 is installed from the center of the bridge girder 2 to one side edge thereof. , Vibration generator 1
2 may be movable between the center of the bridge girder 2 and one side edge thereof.

[0017]

According to the present invention, a vertical vibration and / or a torsional vibration of a bridge girder can be effectively attenuated by moving a vibration generating device to a required position along a guide rail. Since it is only necessary to have one vibration generator and one controller for controlling the same, a conventional vibration generator requiring two vibration generators and two controllers for controlling the same is required. The production cost can be reduced as compared with the vibration damping device.

[Brief description of the drawings]

FIG. 1 is a front view of a state in which a vibration damping device according to an embodiment of the present invention is attached to a bridge girder.

FIG. 2 is a longitudinal sectional view of the main part.

FIG. 3 is a view as viewed in the direction of arrows AA in FIG. 2;

FIG. 4 is a block diagram showing the operation principle.

FIG. 5 is a schematic explanatory view showing an example of an attached state of the vibration damping device.

FIG. 6 is a front view showing a conventional example.

[Explanation of symbols]

 2 Bridge girder (structure) 10 Support stand 11 Guide rail 12 Vibration generator

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Tanaka 5-3-28 Nishikujo, Konohana-ku, Osaka-shi, Japan Inside Hitachi Zosen Corporation (56) References Japanese Utility Model No. 3-62246 (JP, U) 58-129907 (JP, U) JP 4-70498 (JP, B2) JP 4-31607 (JP, Y2) JP 48-1623 (JP, B1) (58) Int.Cl. ⁷ , DB name) F16F 15/02 E01D 1/00 E04H 9/02 341

Claims (1)

(57) [Claims] 1. On a bridge girder that undergoes vertical and / or torsional vibration
A pair of supports are disposed at predetermined positions in the width direction at a required interval from each other, and the width of the bridge girder is provided between the two supports.
Guide rails are installed along the direction
The vibration generator is movably mounted on the
The apparatus comprises a moving base movably fitted to the guide rail.
A table, a weight for generating vertical vibration, and this weight
An actuator for raising and lowering, the moving base
A pinion that engages with the rack formed on the guide rail on the base
And a transfer mode for rotating this pinion forward and reverse.
A vertical vibration detector and a vertical vibration detector provided on the bridge girder.
Based on the detection signal from the torsional vibration detector.
A control device for controlling driving of a motor is provided .