JPH0615895B2 - Seismic isolation device - Google Patents

Description

Description: [Industrial application] The present invention relates to a seismic isolation device for protecting, for example, a mechanical device or the like from vibration such as an earthquake.

[Conventional technology]

FIG. 4 shows, for example, JP-A-60-188877 (Japanese Patent Application No. 59-46).
No. 273) shows a conventional seismic isolation device used in a fusion device, and FIG. 5 shows a plan view from the side of the second base with the second base removed.

In this example, a seismic isolation device is used to improve the seismic resistance of the fusion device. In the figure, (1) is the first
Base, (2) is the second base, (3) is the main body of the fusion device installed on the first base (1), (5) is the first and second bases (1),
A friction damper disposed around the axis of the central column (4) between (2), fixed to the second base (2), and sliding on the lower surface of the first base (1). (6) is a fluid damper radially arranged around the axis of the central column (4), for example, at an equal angle between the first and second bases (1) and (2), which is a hydraulic damper in this example. , Expand and contract in the radial direction. (7) is a support arranged around the axis of the central pillar (4) between the first and second bases (1) and (2). It is swingably supported on the base (2). Support
(7) has a structure in which 20 to 30 metal plates and 20 to 30 rubber plates are alternately laminated, and the overlapping portion is circular. Also, the metal plates on the upper and lower surfaces of the support (7) are fixed to the first and second bases (1) and (2) by welding or the like, respectively, against the vertical load of the first base (1). Is rigid enough, first
A soft spring can be realized for the horizontal load of the base (1) of.

Next, the operation will be described mainly focusing on the seismic function.
When the second base (2) vibrates in the horizontal direction due to an earthquake or the like, the support (7) shears and absorbs this vibration, and the first base (1) has 1/3 to 1 to 1 of the earthquake. Only / 5 vibration is generated. This provided the so-called seismic isolation effect. In addition, the vibration generated on the first base (1) was dissipated by the fluid damper (6) and was quickly damped after the earthquake. Also, this fluid damper (6)
Predicts the earthquake that will occur in advance and adjusts the capacity to respond to it, so that the relative displacement between the first and second bases (1) and (2) during the earthquake can be calculated. The limit was set within a predetermined range. As a result, the deformation occurring in the connecting portion such as the piping between the fusion device main body (3) and the outside was suppressed. The friction damper (5), for example, by setting the friction coefficient to about 0.1, stably fixes the first base (1) to the second base (2) for vibration input up to 100 gal. 300g, which is said to cause a major disaster
For earthquakes of al or more, slip is generated on the friction surface and the seismic isolation effect described above is obtained.

[Problems to be solved by the invention]

Since the conventional seismic isolation device is configured as described above, in order to obtain a sufficient seismic isolation effect, predict the earthquake that will occur and based on that prediction, use the fluid damper (6). It was necessary to adjust the ability beforehand. It is generally difficult to predict this earthquake with high accuracy, and therefore, there is a problem that the seismic isolation device cannot be adjusted optimally and the seismic isolation accuracy is reduced.

The present invention has been made to solve the above-mentioned problems, and by automatically adjusting the damping force that acts between the bases (1) and (2) during an earthquake or the like, the seismic isolation can be performed accurately. The purpose is to obtain a seismic isolation device.

[Means for solving problems]

The seismic isolation apparatus according to the present invention includes an acceleration detector that detects vibration acceleration of the first substrate, an acceleration amplifier that amplifies an output from the acceleration detector, and detects a relative displacement between the first substrate and the second substrate. Displacement detector, the displacement amplifier that amplifies the output from this displacement detector, the absolute value converter that inputs the output from the acceleration amplifier and the output from the displacement amplifier, and outputs the absolute value of each, the allowable vibration acceleration and Limit limiter that sets the limit of relative displacement, comparator that outputs acceleration signal and relative displacement generation ratio from the output of this limit setter and absolute value converter, and outputs a gain signal according to the ratio, displacement amplifier The relative displacement that is the output from the device is input, the differentiator that differentiates this and outputs the relative displacement speed, the control calculator that calculates the product of the output from this differentiator and the gain signal from the comparator, this control calculation Power amplifier for amplifying the output from, and the power amplifier by connexion is driven, in which an electromagnetic damper generates a force from the second base to the first base.

[Action]

The seismic isolation apparatus according to the present invention compares the vibration response of the acceleration and the relative displacement of the seismic isolation apparatus with a set value, and continuously and automatically adjusts the vibration damping rate based on the result. For this reason, the acceleration generated in the first base and the relative displacement generated in the first and second bases can always be kept within the allowable limit, and the response of both can be minimized.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a block diagram showing a seismic isolation device according to an embodiment.
In the figure, (6) is an electromagnetic damper driven by a power amplifier (8) to generate a force from the second board (2) to the first board (1), and (9) is an electromagnetic damper ( (6) is a link connecting the first board (1), (10) is a relative displacement detector for detecting relative displacement between the first board (1) and the second board (2), (11) ) Is a displacement amplifier that amplifies the output signal of the relative displacement detector (10) and outputs relative displacement Bs, (12) is an acceleration detector that detects the acceleration of the first board (1), and (13) is an acceleration An acceleration amplifier that amplifies the output signal of the detector (12) and outputs acceleration As, (14) inputs the output As and Bs of the acceleration amplifier (13) and displacement amplifier (11),
Absolute value converter which outputs as absolute value | As |, | Bs | respectively,
(15) is a limit setter that sets the limit value of the allowable vibration generated in the seismic isolation device, and (16) is the absolute position of acceleration and displacement | As.
Input | and | Bs | respectively from the absolute value converter (14),
Input the set values A and B of acceleration and displacement from the limit setter (15) and And a comparator that outputs a gain signal G according to the ratio, (17) differentiates the output Bs of the displacement amplifier (11) , (18) is the gain signal G which is the output of the comparator (16) and the output of the differentiator (17) Is a control calculator for calculating and inputting to the power amplifier (8).

Next, the operation of the seismic isolation device according to the present invention will be described.

In this device, the values of acceleration A and relative displacement B are set by the limit setter (15) based on the vibration limit allowed for the equipment mounted on the device, and a signal is sent to the comparator (16). . In an example of this set value, A = 100 gal and B = 20 mm ^PP . In this state, the occurrence of an earthquake is awaited. When an earthquake occurs, the seismic isolation operation is performed in the same manner as the conventional seismic isolation device, and the vibration generated in the first base (1) becomes smaller than the vibration generated in the second base (2). At this time, the acceleration As generated on the first substrate (1) and the relative displacement Bs of the first and second substrates (2) are measured and amplified by the respective vibration detectors (12), (10). After that, the absolute value is converted to an absolute value by the absolute value converter (14), and the comparator (16)
Entered in.

The comparator (16) is the set value A, B from the limit setter (15).
And the output signal of the absolute value of acceleration and displacement (14) | As |, | Bs
By comparing |, the occurrence ratio of acceleration and displacement occurring in the seismic isolation device Is obtained and a gain signal G corresponding to the ratio is output.

The operation of the comparator 16 will be described with reference to FIG. The figure shows the absolute value | Bs | of the relative displacement Bs on the horizontal axis.
The value obtained by dividing the displacement setting value B in (15) and the vertical axis showing the absolute value | As | of the acceleration As divided by the acceleration setting value A are shown. The relationship of the signals when vibration occurs is shown. Shows. Using the representation method of this figure, if the damping of the seismic isolation device during an earthquake is set to the best and its response is optimum, the acceleration | As | / A and displacement | Bs | / B shows almost the same value and is distributed on the straight line L.

However, for example, when the acceleration | As | is large and the displacement | Bs | is small, the response is in the range of P in the figure, and in the opposite case is in the range of Q.

Now, assuming that the response is at the Ps point (acceleration response | As | is large and displacement | Bs | is small), the comparator (16) outputs the distance Gs from the straight line L as a gain signal. The above is the comparator
This is the operation of (16).

On the other hand, the displacement Bs which is the output of the displacement amplifier (11) is differentiator (17)
so Is converted to the control calculation unit (18). Control calculator (1
8) is the output G of the comparator (16) and the output of the differentiator (17) Is calculated and the result is output to the power amplifier (8). Fig. 3 (a)
(D) to (d) are waveform charts showing the output forms of the comparator (16) and the control calculator (18) as signals with respect to time. As shown in this figure, the acceleration | A
When s | / A is larger than the displacement | Bs | / B, the gain signal G is negative, and in the opposite case, a positive value is output. The output G of this comparator (16) and the differentiator (17) Becomes the control signal C of the attenuation to be given to the electromagnetic damper (6).

This control signal C is amplified by the power amplifier (8) and sent to the electromagnetic damper (6). The electromagnetic damper (6) receives this signal and applies a force equal to the control signal C to the first base (2) from the first base (2).
Act on the base (1) of. This action becomes the optimum damping force for the vibration of the seismic isolation device.

With the above operation, when the acceleration As of the first base (1) becomes too large, the damping force of the electromagnetic damper (6) is reduced to enhance the seismic isolation effect. When the relative displacement Bs of the second bases (1) and (2) becomes too large, the damping force of the electromagnetic damper (6) is increased and the seismic isolation effect is reduced.

By constantly performing the above operation while the vibration is being generated, the seismic isolation operation can be performed so that the vibration limit set by the limit setting device (15) is not exceeded and further the generated vibration is minimized.

Therefore, it is possible to realize a seismic isolation device capable of responding to vibrations of any nature, without the need for presetting the capacity of the fluid damper (6), which was conventionally required, with high precision. This seismic isolation device may be temporarily ineffective under certain limited conditions. However, this device is mainly intended for earthquakes, and in the case of an earthquake, vibration input is random. Therefore, the input constantly changes, and even if a state in which the effect of this device cannot be expected occurs, that state does not continue for a long time. At the next moment, the vibration input changes,
The vibration damping effect can be obtained.

Further, if the capability of the electromagnetic damper (6) is set to be equal to or less than the damping force of the support body (7) in consideration of the stability condition, a seismic isolation device in which the control system does not diverge under any condition can be obtained.

Further, in the above embodiment, the acceleration detector (12) and the displacement detector (10) detect the vibration of the first board (1) and the second board (2) and input it to the comparator (16). Detects the acceleration of the equipment mounted on the seismic isolation device and the relative displacement between the equipment and the second base,
By inputting this to the comparator (16), it is possible to protect the onboard equipment more completely.

〔The invention's effect〕

As described above, according to the present invention, in the seismic isolation device that isolates the first substrate from the second substrate, an acceleration detector that detects the vibration acceleration of the first substrate, and from this acceleration detector Amplifier that amplifies the output of the first, the first base and the second
Displacement detector that detects the relative displacement of the board, displacement amplifier that amplifies the output from this displacement detector, the output from the acceleration amplifier and the output from the displacement amplifier are input, and the absolute value of each is output. Limiter that sets the limit of acceleration and relative displacement of allowable vibration, obtain the generation ratio of acceleration and relative displacement from the output of this limit setting device and the output of absolute value converter, and obtain the gain signal according to that ratio. Comparator that outputs, Relative displacement that is the output from the displacement amplifier is input, differentiator that differentiates this and outputs the relative displacement speed, Calculate the product of the output from this differentiator and the gain signal from the comparator A control arithmetic unit, a power amplifier for amplifying an output from the control arithmetic unit, and driven by the power amplifier,
By providing an electromagnetic damper that generates a force from the second board to the first board, the vibration response of the device is compared with a set value, and the damping force of the electromagnetic damper is controlled based on this result, This has the effect of providing a highly accurate seismic isolation device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a seismic isolation device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship of signals when vibration occurs in the seismic isolation device according to an embodiment of the present invention.
(a) ~ (d) is a waveform diagram showing the operation according to one embodiment of the present invention as a signal against time, Fig. 4 is a sectional view showing a conventional seismic isolation device used in a fusion device, Fig. 5 Is the second in FIG.
It is the top view seen from the 2nd board | substrate side after removing the board | substrate of FIG. (1) …… First board, (2) …… Second board, (6) …… Electromagnetic damper, (8) …… Power amplifier, (10) …… Displacement detector, (1
1) …… Displacement amplifier, (12) …… Accelerometer, (13) …… Acceleration amplifier, (14) …… Absolute digitizer, (15) …… Limit setter, (16) …… Comparator , (17) …… differentiator, (18) …… control calculator. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A seismic isolation device for isolating a first substrate from a second substrate, an acceleration detector for detecting a vibration acceleration of the first substrate, and an acceleration for amplifying an output from the acceleration detector. An amplifier, a displacement detector for detecting relative displacement between the first board and the second board, a displacement amplifier for amplifying an output from the displacement detector, an output from the acceleration amplifier and an output from the displacement amplifier are input. , Absolute digitizer that outputs each absolute value as acceleration absolute value and relative displacement absolute value, Limit setter that sets acceleration of allowable vibration and limit value of relative displacement as acceleration set value and relative displacement set value, respectively Input the output of the limit setter and the output of the absolute value converter and divide the absolute value of acceleration by the set value of acceleration to generate the ratio of acceleration and the absolute value of relative displacement to the set value of relative displacement. Obtain the relative displacement occurrence ratio obtained by dividing, the comparator that outputs the gain signal obtained from the difference between the acceleration occurrence ratio and the relative displacement occurrence ratio, the relative displacement that is the output from the displacement amplifier A differentiator that inputs and differentiates this to output a relative displacement speed, a control calculator that calculates the product of the output from this differentiator and the gain signal from the comparator, and an output from this control calculator A power amplifier and a second one driven by the power amplifier,
Seismic isolation device equipped with an electromagnetic damper that generates a force from the first base to the first base. 2. The seismic isolation device according to claim 1, wherein the acceleration detector detects acceleration of a mechanical device installed on the first base. 3. A displacement detector according to claim 1, wherein the displacement detector detects a relative displacement between the mechanical device installed on the first base and the second base. Seismic device.