JP2626909B2 - Seismic isolation, anti-vibration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a seismic isolation and vibration proof system against external vibration such as an earthquake.

[Conventional technology]

Seismic isolation and vibration isolation are performed for buildings, floors in buildings, or mechanical devices on the floor.For example, for buildings, laminated rubber is installed between the foundation and the building, and those for mechanical devices are not. Laminated rubber and spring materials are placed between the floor and the machine foundation.

In addition, the floor on which the vertical frame is used as a base portion may be supported by rubber or a spring, and the entire floor may be made of a seismic isolation or vibration proof structure.

In any case, seismic isolation and vibration-proof objects such as buildings and mechanical devices are supported via rubber or spring material so that the vibration period is extended relative to the foundation when subjected to external vibration such as an earthquake. In order to attenuate the vibration by converting the vibration energy into heat or other energy, a hydraulic damper, a magnet damper, or the like is provided between the seismic isolation and vibration isolation target and the foundation.

[Problems to be solved by the invention]

For example, if a seismic isolation or vibration isolation target is intended to achieve a sufficient seismic isolation effect by using only a laminated rubber bearing, a very high laminated rubber is required, and extra space must be secured. No.

Further, the damper normally exerts an integral braking action against external vibration and is not effective. Further, conventionally, a part of the vibration of the base portion is seismically isolated, and the vibration in the process of transmitting the vibration to the object to be isolated, or the vibration as a result of the transmission is captured and acted to attenuate.

Therefore, theoretically perfect control cannot be realized, and vibration control requires time. To shorten the vibration control time, a large amount of energy is required temporarily according to the mass of the seismic isolation and vibration isolation target.

Some dampers include a permanent magnet in a magnetic fluid to apply damping to the movement of the magnet due to the viscosity of the magnetic fluid. However, such a damper is also the same as described above.

An object of the present invention is to solve the disadvantages of the conventional example described above, and to realize the space between the base portion and the seismic isolation and vibration-proof object as small as possible. It is an object of the present invention to provide an anti-seismic and anti-vibration system capable of exhibiting an optimal damper function.

[Means for solving the problem]

In order to achieve the above object, the present invention supports a seismic isolation, a vibration-isolated object with a laminated rubber having a low height rising from a foundation portion,
And, filling a magnetic fluid in a container having an opening on the upper surface,
An electromagnet in which N poles and S poles are alternately scattered in a staggered manner provided on the outer bottom of the container is attached to the base portion side.
A damping plate having a number of holes is inserted into the magnetic fluid in the container, provided on the seismic isolation / vibration isolating object side via a shaft, and configured as a damper with the same height as the low-layer rubber having a low height. And a vertical and horizontal accelerometer on the base
The gist is that the outputs of both accelerometers are introduced into an amplifier via a function converter, the magnetic force of the electromagnet is controlled by the output of the amplifier, and the viscosity of the magnetic fluid is controlled based on this. Is what you do.

[Action]

According to the present invention, the height of the laminated rubber can be suppressed to substantially the same level as that of the damper, and considerably lower than the conventional one.
This laminated rubber absorbs a part of the external vibration, and absorbs the remaining vibration with a damper having a damper characteristic corresponding to the external vibration, so that the vibration can be effectively isolated and damped. Since the vertical accelerometer and the horizontal accelerometer are provided not in the base part and in the base part but in the seismic isolation / vibration isolation target, their height does not affect the height of the laminated rubber.

Also, since the N and S poles of the electromagnet are alternately scattered, the distance between the N and S poles of the magnet is reduced and the number of N and S poles of the magnet is increased. The viscosity can be changed in many places, and as a result, the braking force of the control plate can be increased.

Moreover, since the brake plate has a large number of holes, the inside of the container is not partitioned by this control plate, and the magnetic force of the electromagnet is not only below the control plate, but also the magnetic fluid above it has the same viscosity. As a result, the braking force of the control plate can be increased and the performance of the damper can be improved.

Since the viscosity of the magnetic fluid is controlled based on the output of the two accelerometers detecting acceleration due to external vibration, the vibration in the process of transmitting to the vibration-proof object is taken.
The damping action can be performed quickly.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing one embodiment of a seismic isolation and vibration isolation system according to the present invention. In the drawing, reference numeral 1 denotes a base portion, and 2 denotes a seismic isolation and vibration isolation target.

As mentioned above, the seismic isolation / vibration isolation target 2 may be a building, a floor, a mechanical device, and the like, whereas the foundation 1 may be a building foundation or ground, a building frame, a building floor, and the like. Be eligible.

The object 2 to be subjected to seismic isolation and vibration isolation is supported by a low-rise laminated rubber 3 erected on the base portion 1.

Further, a damper 4 is provided between the object 2 to be subjected to seismic isolation and vibration isolation and the base part 1. The damper 4 is filled with a magnetic fluid 6 in a container 5 having an opening on the upper surface. An electromagnet 7 provided on the floor is attached to the base 1 side, and a brake plate 9 inserted into the magnetic fluid 6 in the container 5 via one shaft 8 is provided on the seismic isolation / vibration isolation target 2. Things. The height of the damper 4 is substantially the same as the height of the laminated rubber 3. Therefore, the height of the laminated rubber 3 is substantially the same as the height of the damper 4.

FIG. 2 shows the electromagnet 7, in which N poles and S poles are alternately dotted. FIG. 3 shows the brake plate 9,
It has a number of holes 9a.

In FIG. 1, reference numeral 10 denotes a vertical accelerometer, 11 denotes a horizontal accelerometer, and these are provided with a base part 1. The outputs of both accelerometers 10 and 11 are introduced into an amplifier 14 via function converters 12 and 13, respectively. The magnetic force of the electromagnet 7 of the damper 4 is controlled by the output of the amplifier 14.

In this manner, the object 2 to be subjected to seismic isolation and vibration isolation is normally supported on the base portion 1 by the laminated rubber 3 so as not to move.

When the foundation 1 vibrates due to an external force such as an earthquake, the laminated rubber 3
Act first to absorb some of that vibration.

The operation equation of the seismic isolation / vibration isolation target 2 when the seismic isolation / vibration isolation target 2 is supported by the laminated rubber 3 is given by the following equation (1).

m + α + Kχ = F (1) where, m: mass of seismic isolation and vibration isolation target 2 k: spring constant of laminated rubber 3 F: external force χ: displacement α: damping constant of laminated rubber 3 Only laminated rubber 3 is used. When the external force F acts when the damping constant α is small, Vibrates at the resonance frequency of In general to obtain a seismic isolation effect so as not transmitted to external vibrations as much as possible by taking smaller than external vibration to f ₀ in the design of laminated rubber.

According to the present invention, the height of the laminated rubber 3 is made lower than that of the related art, and vibrations that cannot be completely absorbed by the laminated rubber 3 are further attenuated by the damper 4.

That is, the magnetic fluid 6 of the damper 4 has a property that the viscosity changes according to the strength of the magnetic field passing through the damper 4, and the movement of the brake plate 9 is controlled by changing the viscosity. Viscosity control of the magnetic fluid 6 of the damper 4 is performed by converting the acceleration and velocity of external vibration detected by the vertical accelerometer 10 and the horizontal acceleration 11 into function voltage converters 12 and 13 to output voltage as a function of acceleration () and velocity (). And this voltage is applied to the electromagnetic force 7
And passing through the magnetic fluid 6 is adjusted.

With such a damper 4, the damping constant α in the above equation (1) can be made optimal according to the acceleration and speed of the vibration, the vibration is immediately attenuated, and the seismic isolation and vibration isolation effects can be exhibited.

〔The invention's effect〕

As described above, the seismic isolation / vibration isolation system of the present invention does not require a large space between the base and the seismic isolation / vibration isolation object because it is supported by low-height laminated rubber, and the damper is externally mounted. By appropriately controlling according to the vibration, it is possible to obtain effective seismic isolation and vibration isolation without waste, which further improves the seismic isolation and vibration isolation effect of the laminated rubber.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a seismic isolation and vibration isolation system of the present invention, FIG. 2 is a plan view of an electromagnet used, and FIG. 3 is a plan view of a brake plate of the same. DESCRIPTION OF SYMBOLS 1 ... Basic part, 2 ... Anti-vibration and anti-vibration target 3 ... Laminated rubber, 4 ... Damper 5 ... Container, 6 ... Magnetic fluid 7 ... Electromagnet, 8 ... Shaft 9 ... Brake plate , 9a… Hole 10… Vertical accelerometer, 11… Horizontal accelerometer 12, 13… Function converter, 14… Amplifier

Claims (1)

(57) [Claims] An object to be subjected to seismic isolation and vibration isolation is supported by a low-rise laminated rubber raised from a base portion, and a magnetic fluid is filled in a container having an opening on an upper surface, and an outer bottom portion of the container is provided. N
A pole provided with electromagnets in which poles and S poles are alternately scattered is attached to the base portion side, while a brake plate having a large number of holes is inserted into the magnetic fluid in the container, and is released via a shaft. Quake,
A damper is provided at the same height as the low-layer rubber that is provided on the vibration-proof object side, and a vertical accelerometer and a horizontal accelerometer are provided at the base portion, and the outputs of both accelerometers are converted into functions. A magnetic force of the electromagnet is controlled by an output of the amplifier, and a viscosity of the magnetic fluid is controlled based on the magnetic force of the electromagnet.