JP2682777B2 - 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 damping vertical vibrations of structures such as bridges under construction and buildings under construction.

[0002]

2. Description of the Related Art Conventionally, there is a damping device shown in FIG. 4, for example, as a damping device for damping vertical vibration. This is machine frame 1
5, a slider 16 supported by the slider 5, a weight 18 connected to the slider 16 via a connecting rod 17, and a crank for raising and lowering the weight 18 by raising and lowering the weight 18 via the slider 16. Consists of mechanism 19,
The vibration frequency of the weight 18 is returned by changing the rotation speed of the crank mechanism 19.

[0003]

In the above conventional vibration damping device, a crank mechanism for converting a rotational force into a linear reciprocating driving force.
Due to this structure, the component force of the lateral inertial force generated by the vertical movement of the weight 18 is transmitted via the slider 16 to the machine frame 15
Since it is applied to the horizontal direction, the horizontal vibration force acts on the structure to which the vibration damping device is attached.

Further, since the weight 18 only moves up and down with a constant amplitude due to the mechanism of the crank mechanism 19, it can generate only an exciting force of a single frequency, so that a plurality of vibrations overlap each other. It is difficult to effectively dampen vibrations.

Further, the crank mechanism 19 may be damaged, for example.
When the rotation drive of is stopped, the weight 18 cannot move up and down,
The vibration control function does not work at all. In view of the above conventional problems, the present invention does not generate an exciting force in a direction different from vibration,
It is another object of the present invention to provide a vibration damping device that can effectively dampen superposition vibrations and that has a vibration damping function even when the driving is stopped.

[0006]

In order to achieve the above object, the present invention is erected on a base mounted on a structure.
Guide rod and actuator on this guide rod
Actuator guided up and down freely through a support plate
And along the guide rod above the actuator
It is arranged so that it can be moved up and down and is driven up and down by an actuator.
And the weight provided on the actuator support plate.
The clutch that can fix and release the actuator on the guide rod.
The pump mechanism and the space between the base and the actuator support plate.
The actuator and the heavy load when the clamp mechanism is released.
And a spring for elastically supporting the weight .

[0007]

In the above structure, the base is attached to the structure and the weight is moved up and down along the guide rod by driving the actuator while the actuator is clamped to the guide rod by the clamp mechanism. As a result, a vertical force is positively applied to the structure, and the direction of the force due to the vibration of the weight is applied in the direction opposite to the vertical vibration of the structure to damp the vibration of the structure. be able to.

Further, in particular, when the vibration frequency of the structure changes or when a plurality of vibrations cause overlapping vibrations, the change of the vibration frequency or the vibration waveform is calculated at the design stage or on site. It is possible to continuously and effectively dampen the vibration of the structure by indexing by actual measurement and controlling the actuator based on the indexed set value or measured value.

Further, for example, when the driving of the actuator is stopped due to a failure, the weight of the weight is supported by the spring through the actuator by releasing the clamp of the clamp mechanism. Since the weight plays a role of a vibration absorber and the weight of the structure vibrates to absorb the vibration energy of the structure, the vibration of the structure can be damped.

[0010]

An embodiment of the present invention will be described below. As shown in Fig. 3, when constructing a cable-stayed bridge, after the bridge towers 1 and 1 are erected at a predetermined interval, the bridge girders 2 and 2 are gradually laid horizontally from the respective bridge towers 1 and 1. While extending the bridge girder 2,
A cable 3 is stretched between the bridge girder 2 and each bridge tower 1,1 to maintain the horizontal state of each bridge girder 2,2, and finally to connect the bridge girders 2,2 facing each other. However, during this erection work, the bridge girders 2 are likely to be vibrated by the working machines and wind pressures that move on them, and leaving them in that state may cause resonance phenomena. Since it is dangerous for the bridge girders 2 and 2, temporary piers are installed on the girders 2 and 2 to support them while extending them.

FIGS. 1 and 2 show a vibration damping device 4 provided on the bridge girder (structure) 2. The base 5 is attached to the bridge girder 2 and a weight for generating a vertical force. 6
And an actuator 7 for moving the weight 6 up and down.

The base 5 has a rectangular shape, and guide rods 8 are provided upright at the four corners thereof. The weight 6 has a weight support plate 9 supported by the guide rod 8 so as to be vertically movable.
It is fixed to the central part of the.

The actuator 7 is driven to expand and contract by a liquid such as oil or a gas such as air, and its main body 7a is mounted on the central portion of an actuator support plate 10 which is supported by the guide rod 8 so as to be vertically movable. The telescopic rod portion 7b is fixed and is connected to the elevating table 9.

A spring 11 for supporting the actuator 7 is externally fitted between the base 5 of each guide rod 8 and the actuator support plate 10, and a clamp mechanism 12 is provided between each spring 11 and the actuator support plate 10. Is provided.

The clamp mechanism 12 is fixed to the lower surface of the actuator support plate 10 and the guide rod 8 is provided.
A casing 12a which is loosely fitted to the casing 12a, a pair of clamp pawls (not shown) which are arranged to face each other with the guide rod 8 sandwiched in the casing 12a, and a clamp pawl drive device which moves the clamp pawls toward and away from each other. The actuator 7 can be fixed to the guide rod 8 by driving the clamp claw driving device to clamp the guide rod 8 with both clamp claws.

In FIG. 1, 13 is an attenuator made of a rubber material or the like interposed between the main body 7a of the actuator 7 and the base 5, and 14 is an upper end portion of each guide rod 8 integrally. The connecting plate is a connecting plate, and an opening 14a for passing the weight 6 is formed in the center thereof.

The operation principle of the vibration damping device 4 will be described below.
First, the guide rod 8 is clamped by the clamp mechanism 12 and the actuator 7 is driven in a state where the actuator 7 is fixed to the guide rod 8 to expand and contract the telescopic rod portion 7b. As a result, the weight 6 moves up and down along the guide rod 8, and this action is repeated, so that a vertical force can be applied to the structure 2.

According to the above construction, since the telescopic rod portion 7b linearly expands and contracts only in the vertical direction and the weight 6 moves up and down in the vertical direction, the inertia force of the weight 6 causes No horizontal force acts, and therefore no horizontal force acts on the bridge girder 2.

Here, for example, as shown in FIG. 3, when damping the vibration of the bridge girder 2 under construction, the change of the frequency of the bridge girder 2 and the waveform of its vibration frequency are calculated or calculated at the design stage. The actuator 7 is controlled by a control device (not shown) based on the set value or the measured value obtained by actual measurement at the site, and the expansion / contraction speed of the expansion / contraction rod portion 7b of the actuator 7 and its expansion / contraction length. Adjust. As a result, no matter how the vibration of the bridge girder 2 changes, or even if the vibration is a superposition vibration in which a plurality of vibrations are superposed, it can be reliably damped.

By releasing the clamp of the clamp mechanism 12, the weight 6 is supported by the spring 11 and the attenuator 13 via the actuator 7, and the weight 6 is vertically vibrated by the vibration of the structure 2. The vibration of the bridge girder 2 may be damped. Thereby, the vibration damping device of the present invention,
The active type in which the actuator 7 actively vibrates can be changed to the passive type in which the structure 2 vibrates passively.

[0021]

According to the present invention, a mechanism for linearly moving up and down by an actuator that expands and contracts is used as an ascending / descending driving means for the weight, and the inertial force of the weight is not applied horizontally to the guide rod. Therefore, compared to the conventional example described at the beginning, the horizontal force does not act on the structure. .

When the vibration frequency of the structure changes or when a plurality of vibrations cause overlapping vibrations, the expansion / contraction driving speed and expansion / contraction length of the actuator are appropriately controlled in accordance with the vibrations. It is possible to effectively damp the vibration of the structure.

Further, by releasing the clamp of the clamp mechanism, the weight can freely vibrate, and the vibration damping device of the present invention can be changed from an active type to a passive type dynamic vibration absorber.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a vibration damping device that is an embodiment of the present invention.

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is a schematic explanatory view showing a mounted state of the vibration damping device.

FIG. 4 is a schematic longitudinal sectional view showing a conventional example.

[Explanation of symbols]

2 Bridge girder (structure) 5 Base 6 Weight 7 Actuator 8 Guide rod 10 Actuator support plate 11 Spring 12 Clamp mechanism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Tanaka 5-3-8 Nishi-Kujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd.

Claims (1)

(57) [Claims] 1. Standing on a base that is attached to a structure
The guide rod and the actuator support plate move up and down the guide rod.
An actuator that is freely guided and moves up and down along the guide rod above the actuator.
It is freely arranged and driven up and down by an actuator.
A weight and the actuator provided on the actuator support plate.
The clamp mechanism that can fix and release the actuator to the guide rod, and the clamp mechanism that is interposed between the base and the actuator support plate.
Elastically supports the actuator and weight when the pump mechanism is released
A vibration damping device , comprising: