JP2561369B2 - Vibration control device for structures - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vibration damping device that suppresses shaking of a structure during an earthquake or the like.

(Prior Art) In order to suppress the shaking of a structure when an earthquake occurs, a mass of a predetermined large weight is movably arranged on the upper part of the structure, and an actuator is mounted on the mass from a two-dimensional direction. A vibration damping device for connecting a supporting reaction force from an actuator to a structure so as to cancel a vibration input to the structure by expanding and contracting the actuator in response to a vibration wave when an earthquake occurs Proposed by Sho 63-226466.

By the way, in this case, since a heavy mass is supported on the floor by a roller or the like and has a rolling frictional force, in order to move the mass with a good response to a vibration input,
A large capacity actuator is needed.

(Problems to be solved by the invention) Therefore, instead of supporting a heavy mass on the floor surface by rolling contact, the mass and the structure are suspended by, for example, four wires. The applicant of the present invention has proposed a device in which the influence of the rolling frictional force at the time of mass movement is eliminated by connecting the actuators and the actuators with each other to enable the vibration control with good responsiveness.

By the way, in this case, when the driving force of the actuator is applied to a position vertically displaced with respect to the center of gravity of the mass suspended by the wire, a rotational moment is generated in the mass.

However, in such a structure in which the mass is suspended by the wire, the wire can withstand a tensile load, but cannot withstand a compressive load at all, so the rotational moment causes the mass to move in an irregular motion different from the motion of the actuator. In some cases, the original damping effect was significantly reduced.

Therefore, it is necessary to sufficiently consider the connection point of the actuator with respect to the mass so that such a rotation moment is not generated or is minimized.
For this reason, there is a problem in that the actuators are connected to each other due to large design restrictions.

In order to solve such a problem, the present invention regulates the irregular movement of the mass by suspending the mass via a plurality of rigid suspension arms that can cope with a compressive load, and only expands and contracts the actuator. It is an object of the present invention to provide an apparatus adapted to deal with the situation appropriately.

(Means for Achieving the Object) According to the present invention, a mass of a predetermined weight is suspended by a plurality of rigid suspension arms whose base ends are rotatably supported in a three-dimensional direction with respect to a structure. The mass and the structure were connected from a substantially horizontal two-dimensional direction via an actuator that expands and contracts according to the vibration wave of the structure.

(Operation) When the actuator expands and contracts in response to external vibration, the mass suspended by the suspension arm moves in a horizontal plane from the rest position in response to this.

As the mass moves, the position of the center of gravity changes, which causes a moment, and the tension applied to each arm changes in a direction to cancel the moment. However, since the arm is rigidly configured and can withstand not only tensile load but also compressive load, it regulates the irregular movement of the mass and depends only on the expansion and contraction movement of the actuator to absorb external vibration. Can operate properly.

(Examples) Examples of the present invention will be described below.

As shown in FIG. 1 and FIG. 2, a mass 1 having a predetermined large weight is horizontally moved from a supporting frame 8 fixed to the upper part of the structure such as a roof of the structure by a suspension arm 2 composed of four rigid bodies. Is hung on.

The arms 2 are connected to each other via universal joints (universal joints) 3 above and below, so that the mass 1 can freely move in a horizontal plane.

Then, the mass 1 and the support frame 8 are connected from the perpendicular direction (two-dimensional direction) by hydraulic cylinders 4 and 5 as two actuators. Hydraulic cylinders 4, 5
The cylinder tubes 4A and 5A are connected to the support frame 8 and the piston rods 4B and 5B are connected to the central portion of the mass 1 via universal joints 6 and 7, respectively.

With respect to the hydraulic cylinders 4 and 5, a servo valve housed in the valve assembly 9 operates according to a command from a controller (not shown) in accordance with the magnitude and direction of vibration when an earthquake or the like occurs, so that the hydraulic pressure is increased. The supply of pressure oil from the source is controlled, and the hydraulic cylinders 4 and 5 expand and contract to relatively displace the heavy mass 1 so as to cancel the vibration of the structure.

In this embodiment, in order to immediately detect the occurrence of an abnormality such as cutting or breakage of each arm 2, each arm 2 detects tension such as a strain gauge in order to detect the occurrence of the abnormality. A vessel 10 is attached to each.

As shown in FIG. 3, the output of the tension detector 10 is input to the CPU 12 via the A / D converter 11, and whether or not an abnormality such as breakage of the arm 2 has occurred based on the detected value. Judgment is made, and in case of abnormality, input / output interface (I / O) 1
Abnormality information is output via 4.

Tension corresponding to the load of the suspended mass 1 acts on each arm 2, and this tension is applied to the hydraulic cylinders 4, 5 by the mass 1.
Is displaced in the horizontal plane via the, and corresponding to a moment (which is proportional to the inclination angle of the arm 2) generated along with the movement of the center of gravity of the mass 1, it changes so as to cancel it.

When the arm 2 is cut or the like, the load applied to the arm 2 becomes zero, and the tension does not change even if the mass 1 moves. Therefore, when the change in the tension of the arm 2 that occurs when the mass 1 moves is less than or equal to a predetermined value, it can be determined that an abnormality such as disconnection of the arm 2 has occurred.

By the way, even if the absolute value of the tension (load) applied to the arm 2 is detected, the disconnection of the arm 2 and the like can be determined, but in this case, the absolute load cannot be easily detected. To detect a change, it is sufficient to attach a strain gauge to the arm 2 with the mass 1 suspended, and the change in tension can be detected easily and accurately.

In the CPU 12, the hydraulic cylinder 4,
A calculation for controlling the expansion / contraction operation of 5 is also performed, and this calculated value is output to a servo amplifier (not shown) for controlling the hydraulic cylinders 4 and 5 via the D / A converter 13.

By the way, in the present invention, since the mass 1 is suspended by the four rigid suspension arms 2, the hydraulic cylinder 4,
As shown in FIG. 1, the connecting point of the mass 5 to the mass 1 is located above the center of gravity of the mass 1, and the hydraulic cylinder
Even if a rotational moment is generated in the mass 1 by driving 4,5, the suspension arm 2 can withstand not only a tensile load but also a compressive load. It does not cause a movement different from the expansion and contraction of 5 and 5.

In other words, due to the restraint force of the suspension arm 2, the movement of the mass 1 in the three-dimensional direction correctly depends only on the expansion and contraction of the hydraulic cylinders 4 and 5, and the mass 1 can be accurately subjected to vibrations such as an earthquake. It is possible to take a corresponding movement and efficiently absorb the vibration.

It should be noted that the present invention is not limited to the above-described embodiment, but the mass 1 can be used even when it is carried out in other forms.
The connection point of each suspension arm 2 with respect to is selected so that each suspension arm 2 can suppress the movement of the mass 1 that does not depend on the expansion and contraction of the hydraulic cylinder.

(Effect of the Invention) As described above, according to the present invention, the mass is supported in the three-dimensional direction by the rigid suspension arm.
Irregular movement that does not depend on the expansion and contraction of the actuator can be prevented even if a rotational moment acts on the mass, and even if the connecting point of the actuator deviates vertically from the center of gravity of the mass, the vibration damping effect of the mass can be effectively exhibited. As a result, the degree of freedom in mounting the actuator is increased, and the space required for installing the mass and the height can be reduced.

In particular, according to the present invention, it is possible to prevent the irregular movement of the mass due to the rotational moment when the connection point with the actuator is deviated from the center of gravity of the mass as described above. An effective vibration absorption effect due to the movement of the mass can be obtained, and there are few design restrictions on the connecting portion between the mass and the actuator and structurally high precision is not required, so the assembly and maintenance of the device becomes easy. You can also get the effect.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a plan view, and FIG. 3 is a block diagram of a control device. 1 ... Mass, 2 ... Suspension arm, 3 ... Universal joint, 4,
5 …… hydraulic cylinder (actuator), 8 …… frame.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-97342 (JP, A) JP-A-63-226466 (JP, A)

Claims (1)

(57) [Claims] 1. A mass of a predetermined weight is suspended by a plurality of rigid suspension arms whose base ends are rotatably supported in a three-dimensional direction with respect to the structure, and the mass and the structure are substantially horizontal. 2
A vibration damping device for a structure, wherein the vibration damping device is connected through an actuator that expands and contracts in a dimensional direction in response to a vibration wave of the structure.