JP2013068265A - Seismic isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a seismic isolation effect by reducing a pressure loss (attenuation amount) with a simple configuration and by using an auxiliary tank effectively.SOLUTION: A seismic isolator 120 includes: an air spring 150 interposed between a slab 110 and a floor structure 130 of a building; and a plurality of auxiliary tanks 152 communicating with the air spring via a communication pipe 154. The plurality of auxiliary tanks is installed in parallel to the air spring. Thereby, a seismic isolation effect is improved by suppressing a pressure loss by the communication pipe and by consecutively installing the appropriate number of auxiliary tanks.

Description

  The present invention relates to a seismic isolation device that reduces ground motion and effectively protects a floor structure.

  The seismic isolation device is a device that reduces vibrations (earthquake motion) during an earthquake with a flexibly displaceable isolator and transmits the vibrations to a floor structure loaded with computers and precision equipment as much as possible. There are seismic isolation devices that function in the vertical direction and those that function in the horizontal direction. As the vertical seismic isolation device, a coil spring (for example, Patent Document 1) or an air spring is used. Here, the smaller the spring constant of the coil spring or the air spring, the less the vibration of the ground (slab) is transmitted to the floor structure.

  However, there is a limit to simply increasing the volume of the air spring in order to reduce the spring constant. Therefore, a technique is known that uses a coil spring or the like in parallel with the air spring to realize a long period of vibration in the vertical direction (for example, Patent Documents 2 and 3). In addition, a technique in which an auxiliary tank is connected to the air spring to increase the apparent volume of the air spring is disclosed (for example, Patent Document 4).

Japanese Patent Laid-Open No. 10-288234 JP 2007-71399 A JP 2004-44748 A JP-A-10-205112

  In the technology in which the auxiliary tank is connected to the air spring, by increasing the apparent volume of the air spring, it is possible to reduce the influence on the floor structure due to the vibration of the slab when an earthquake occurs. In addition, the diameter of the communication pipe that connects the air spring and the auxiliary tank is reduced, and the communication pipe has a damping function, so that the floor structure shakes in response to load changes due to human movement and walking in normal times. Can also be suppressed.

  However, since the volume that the auxiliary tank can occupy in the limited space between the slab and the floor structure is small compared to the volume required for the auxiliary tank, the auxiliary tank usually has a plurality of pressure-resistant containers of a predetermined volume connected in series. Configured. Moreover, conventionally, the auxiliary tank is connected in series with the air spring from the relationship between the arrangement of each auxiliary tank and the handling with other structural members.

  When a plurality of auxiliary tanks are connected in series in this way, the occupied space is limited by the slab and the floor structure, so it is difficult to arrange the auxiliary tanks on a straight line. Therefore, it is necessary to dispose the air spring and the auxiliary tank, or the auxiliary tanks in different directions of the vents that are connected to the other, and to provide an elbow or the like in which the central axis of the pipe is refracted in the communication pipe. there were. Then, pressure loss (pressure loss) due to the elbow occurred, and a situation that greatly exceeded the assumed attenuation amount occurred. Also, by connecting the auxiliary tanks in series, the pressure loss in the auxiliary tanks separated from the air springs increases, and the pressure fluctuations are not transmitted to the separated auxiliary tanks, and the number of auxiliary tanks installed is increased. However, there is also a problem that it no longer contributes to the reduction of the spring constant.

  In view of such problems, the present invention aims to provide a seismic isolation device capable of improving the seismic isolation effect by maintaining the damping effect by the communication pipe and effectively using the auxiliary tank. It is said.

  In order to solve the above problems, a seismic isolation device of the present invention includes a slab of a building and an air spring that is narrowly mounted on a floor structure, and a plurality of auxiliary tanks that communicate with the air spring through a communication pipe. The plurality of auxiliary tanks are connected to the air spring in parallel.

  The communication pipe may communicate a plurality of vent holes provided in the air spring and a plurality of auxiliary tanks, respectively.

  Among the plurality of vents, at least one vent may have a larger opening area than the other vents. At this time, the diameter ratio between one vent and another vent may be greater than 1 and less than 16.

  The communication pipe may extend from a vent provided in the air spring and further branch into a plurality of branches, thereby communicating the air spring with the plurality of auxiliary tanks.

  According to the present invention, it is possible to improve the seismic isolation effect by maintaining the damping effect by the communication pipe with a simple configuration and effectively using the auxiliary tank.

It is explanatory drawing for demonstrating the schematic structure of a seismic isolation system. It is explanatory drawing which showed the positional relationship of an air spring and several auxiliary tanks. It is explanatory drawing which showed the dynamic model of the system by which the auxiliary tank was connected to the air spring. It is explanatory drawing for demonstrating the influence on the floor structure of the vibration applied to the slab. It is explanatory drawing which showed the positional relationship of an air spring and several auxiliary tanks.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(Seismic isolation system 100)
FIG. 1 is an explanatory diagram for explaining a schematic configuration of the seismic isolation system 100. The seismic isolation system 100 includes a slab 110, a seismic isolation device 120, and a floor structure 130, and can effectively protect the floor structure 130 by reducing seismic motion.

  The slab 110 is a floor structure at the top of a structure foundation in a building or a floor structure between upper and lower floors, and indicates a plank such as stone or concrete that supports a load perpendicular to the surface. In this embodiment, the slab 110 vibrates integrally with the ground during an earthquake. The seismic isolation device 120 is a device that prevents the vibration applied to the slab 110 during an earthquake from being transmitted to the floor structure 130 as much as possible. In this embodiment, an air spring and an oil damper are used as a vertical isolator that does not transmit vibration. The floor structure 130 corresponds to a floor portion of an area where a resident or worker can move within a building.

  When an earthquake or the like occurs, the slab 110 vibrates integrally with the ground. However, since the seismic isolation device 120 reduces vibration transmitted from the slab 110 to the floor structure 130, a resident on the floor structure 130. And the impact of the earthquake on workers is reduced. At this time, in order to increase the seismic isolation capability, the spring constant of the seismic isolation device 120 should be small. However, simply to soften the spring element of the air spring in the seismic isolation device 120 in order to increase the seismic isolation capability, the load fluctuation caused by movement or walking of residents or workers on the floor structure 130 can be prevented. In addition, the floor structure 130 is shaken, and the occupants and workers feel uncomfortable. Further, when a computer or a precision device is loaded on the floor structure 130, the influence of such vibration must be avoided as much as possible.

  Therefore, in the present embodiment, a plurality of auxiliary tanks are arranged in parallel with the air springs constituting the seismic isolation device 120, and further, the communication portion is devised, thereby allowing the floor structure 130 due to the vibration of the slab 110 when an earthquake occurs. In addition to reducing the influence on the floor, the swing of the floor structure 130 in response to a load change caused by a person's movement or walking is suppressed in normal times. Hereinafter, the detailed structure of the seismic isolation apparatus 120 which can implement | achieve such an objective is demonstrated.

(Seismic isolation device 120)
As shown in FIG. 1, the seismic isolation device 120 includes an air spring 150, an auxiliary tank 152, a communication pipe 154, an oil damper 156, a relative displacement detector 158, an air pressure controller 160, and an air source 162. And a servo valve 164.

  The air spring 150 is an elastic body formed by enclosing air (gas) of a predetermined pressure in an exterior formed of a bellows-type or diaphragm-type flexible container. The air spring 150 is confined to the slab 110 and the floor structure 130 of the building. Further, the air spring 150 can arbitrarily set a spring constant by changing the volume of air contained therein, and can realize extremely soft elasticity. Therefore, it is possible to reduce micro-earthquakes that cannot be absorbed by the metal springs, and it is difficult to resonate depending on the earthquake motion.

  If a metal spring is used as the elastic body of the seismic isolation device 120, if the weight of the load on the floor structure 130 changes due to downsizing such as a computer and the natural frequency of the floor structure 130 increases (the natural period is When the time is shortened), the metal spring itself must be replaced with a new metal spring having a small spring constant. Moreover, the problem that a seismic isolation capability will fall by hardening of such a metal spring will also arise. The air spring 150 used in the present embodiment is advantageous in maintaining maintenance and seismic isolation capability because the natural frequency hardly changes even when the loaded load changes.

  In addition, since the air spring 150 is an elastic body formed of a flexible container, it has not only the vertical direction but also the horizontal isolation capability. Separately, a laminated rubber or the like is generally used. For convenience of explanation, in the present embodiment, attention is paid only to the action of the air spring 150 that bears vertical isolation, and description of horizontal isolation is omitted.

  Here, the air spring 150 using air is employed, but not limited to air, a fluid spring or the like in which a fluid according to the application such as a liquid is sealed can also be used. Here, for convenience of explanation, the gas in the air spring 150 is expressed as air, but the component is not limited and various gases can be applied.

  The auxiliary tank (auxiliary air chamber) 152 includes a plurality of pressure-resistant containers and communicates with the air spring 150 through the communication pipe 154. Moreover, it may communicate with another auxiliary tank 152.

  As described above, it is necessary to enlarge the air spring 150 in order to increase the natural period of the earthquake motion. Here, the auxiliary tank 152 is connected to the air spring 150 to increase the apparent volume of the air spring 150 and to increase the natural period. In order to effectively increase the apparent volume of the air spring 150, it is necessary to increase the volume of the auxiliary tank 152. However, since the space between the slab 110 and the floor structure 130 is narrow and there are other structural members, the shape and occupied volume of the auxiliary tank 152 are limited, and the degree of freedom in arrangement is small. Here, the capacity is secured by arranging a plurality of auxiliary tanks 152 in parallel. As will be described in detail later, in the present embodiment, the air spring 150 and the plurality of auxiliary tanks 152 are connected in parallel rather than in series.

  The communication pipe 154 communicates the air spring 150 and the auxiliary tank 152. Further, the auxiliary tanks 152 may be communicated with each other. The communication position of the communication pipe 154, the air spring 150, and the auxiliary tank 152 in FIG. 1 is for explaining schematically, and is actually arranged at an appropriate place in consideration of rigidity and the like. Further, the communication pipe 154 also has a function of attenuating seismic motion by reducing the diameter of the pipe with, for example, an orifice (for example, by setting the diameter to 10 mm or less). Such restriction of the communication pipe 154 can be adjusted through adjustment of the opening degree of the variable valve, replacement of washers having different inner circumferences, and the like.

  The communication pipe 154 can be provided with a relief valve, a solenoid valve, or the like. When the pressure difference between the air spring 150 and the auxiliary tank 152 exceeds a predetermined threshold value, the relief valve opens its valve, communicates the air spring 150 and the auxiliary tank 152, and the pressure difference between the air spring 150 and the auxiliary tank 152. Is again below the predetermined threshold, the valve is closed. The electromagnetic valve detects the occurrence of an earthquake with a seismic wave detection sensor, and opens and closes an electrically driven valve. Thus, the spring constant of the air spring 150 can be switched according to the magnitude of the earthquake motion.

  The oil damper 156 absorbs (attenuates) vibration energy due to seismic motion, and apportions a damping function necessary for the seismic isolation device 120 to a damping mechanism including the air spring 150 and the auxiliary tank 152. As the oil damper 156, one having a fixed damping coefficient (damping characteristic) can be used, but a semi-active type oil damper 156 in which the damping coefficient is switched according to the magnitude of seismic motion may be used.

  By the way, the air spring 150 changes the volume in the air spring 150 according to the load fluctuation on the floor structure 130 in order to obtain the internal pressure corresponding to the load fluctuation, and the vertical position of the floor structure 130 changes. There is a case. Here, the level control of the floor structure 130 is performed using the relative displacement detector 158, the air pressure controller 160, the air source 162, and the servo valve 164 shown in FIG.

  The relative displacement detection unit 158 is configured by a laser displacement meter or the like that stands on the slab 110 and detects a laser reflection time with respect to the floor structure 130. The relative displacement between the slab 110 and the floor structure 130 (relative distance in the vertical direction). Is detected.

  The air pressure control unit 160 generates a control command that cancels the displacement according to the displacement of the floor structure 130 itself due to the load variation on the floor structure 130, and transmits the control command to a servo valve 164 described later.

  The air source 162 is composed of a compressor, and can supply air to the air spring 150 and the auxiliary tank 152 to arbitrarily add atmospheric pressure higher than atmospheric pressure.

  The servo valve 164 controls the air pressure of the air source 162 according to a control command from the air pressure control unit 160 and increases or decreases the air pressure of the air spring 150 and the auxiliary tank 152. In the initial setting, air is supplied from the air source 162 so that the air pressures of both the air spring 150 and the auxiliary tank 152 become a predetermined air pressure set in advance.

(Example of connecting the air spring 150 and the auxiliary tank 152)
As described above, the air spring 150 can increase the apparent volume by continuously providing one or a plurality of auxiliary tanks 152. For example, when the air spring 150 has a bellows shape, if the rate of change of the cross-sectional area of the air spring 150 is ignored, the spring constant of the air spring 150 is roughly proportional to the reciprocal of the volume, and the natural frequency is the spring. It is proportional to the square root of the constant. Therefore, when the total volume (total volume) of all the one or more auxiliary tanks 152 is three times that of the air spring 150 and the air spring 150 and the auxiliary tank 152 are communicated, the spring constant of the air spring 150 is communicated. 1 / (1 + 3) = 1/4 times when not, and the natural frequency is 1 / √4 = 1/2 times. For example, if the natural frequency when the auxiliary tank 152 is not communicated is 1 Hz, then it becomes 0.5 Hz when communicated. Thus, the longer the auxiliary tank 152 is connected, the longer the natural period can be achieved, and the influence on the floor structure 130 due to the vibration of the slab 110 when an earthquake occurs can be reduced. However, it is desirable that the total volume of the auxiliary tank 152 is not more than three times the volume of the air spring 150.

  Further, as described above, the seismic isolation device 120 can have a damping function by reducing the diameter of the communication pipe 154 that communicates the air spring 150 and the auxiliary tank 152. The amount of attenuation by the communication pipe 154 increases in proportion to the square of the increase in the velocity of the fluid flowing through the communication pipe 154. Therefore, the higher the frequency of vibration that the air spring 150 receives, the greater the amount of attenuation. Thus, not only the influence on the floor structure 130 due to the vibration of the slab 110 at the time of the earthquake is reduced, but also the high frequency of the floor structure 130 according to the load change caused by the movement of the person or walking is normal. It is possible to suppress shaking.

  By the way, conventionally, such an auxiliary tank 152 has been connected in series with the air spring 150 in view of its arrangement and handling with other structural members. When the auxiliary tanks 152 are connected in series, the fluctuation range of the pressure loss of the elbow used for the connection is large, so that it is difficult to set the overall attenuation, and the adjustment of the attenuation is unavoidable, or the air spring 150 In the auxiliary tank 152 that is separated from the air spring 150, that is, the auxiliary tank 152 in which a plurality of other auxiliary tanks 152 exist between the air springs 150, pressure loss due to the other auxiliary tanks 152 increases, and pressure fluctuations are not transmitted. Thus, there is a problem that an effective attenuation effect cannot be obtained in the communication pipe 154. In other words, the fact that the damping effect cannot be obtained in the communication pipe 154 means that the auxiliary tank 152 in the subsequent stage does not function as an apparent volume, and the auxiliary tank 152 in the subsequent stage contributes to the reduction of the spring constant. I did not. Therefore, in the present embodiment, the air spring 150 and the plurality of auxiliary tanks 152 are connected in parallel, and the distance between the air spring 150 and the communication pipe 154 is shortened.

  FIG. 2 is an explanatory diagram showing the positional relationship between the air spring 150 and a plurality of auxiliary tanks 152 (indicated by 152a, 152b, and 152c in FIG. 2). In FIG. 2A, the air spring 150 is provided with three vent holes 150a, 150b, 150c, and the communication pipe 154 communicates the vent holes 150a, 150b, 150c with the three auxiliary tanks 152, respectively. However, the number of auxiliary tanks 150 is not limited to three, and the arrangement of the vent holes 150a, 150b, and 150c in the air spring 150 is not limited to the illustrated position.

  By connecting the air spring 150 and the auxiliary tanks 152a, 152b, and 152c in parallel in this way, the total diameter of the communication pipe 154 is three times that of one case, and the flow rate of each communication pipe 154 and The flow rate is 1/3. If it does so, the attenuation amount borne by each communication pipe 154 will be 1/9. Therefore, in order to maintain the attenuation corresponding to the case where the auxiliary tanks 152 are provided in series, the diameter of each communication pipe 154 may be reduced to 1/3.

  Here, since the air spring 150 and the auxiliary tanks 152a, 152b, 152c are communicated in parallel, the distance between the air spring 150 and the auxiliary tanks 152a, 152b, 152c can be shortened uniformly. Then, even if the auxiliary tank 152 is further added, the auxiliary tank 152 functions as an apparent volume, and the spring constant can be further reduced. Such an event will be described in detail below using a dynamic model and a vibration transmissibility.

FIG. 3 is an explanatory diagram showing a dynamic model of a system in which the auxiliary tank 152 is connected to the air spring 150. FIG. 3 (a) shows a dynamic model when auxiliary tanks 152a, 152b, and 152c are connected in parallel in the present embodiment, and FIG. 3 (b) shows a conventional three auxiliary tanks 152 connected in series. The dynamic model in the case of connecting in series is shown. Here, the auxiliary tank 152 can be expressed by an equivalent expression in which the spring stiffness K and the damping coefficient C are connected in parallel. In the model of FIG. 3B, for example, if any one of the damping coefficients C ₁ , C ₂ , and C ₃ is excessively large, the subsequent spring and damping function regardless of the numerical values. Disappear. This means that if a connection point in the middle is physically closed, air will no longer reach the subsequent auxiliary tank 152 and cannot be used. Therefore, even if the number of stages of the auxiliary tanks 152 connected in series is increased, the auxiliary tanks 152 after the arbitrary auxiliary tanks 152 no longer contribute to the reduction of the spring constant. On the other hand, in FIG. 3A, the damping coefficients C ₁ , C ₂ , C _{3 of} the auxiliary tanks 152 arranged side by side affect the entire seismic isolation system 100 equally, and the damping coefficients C ₁ , C ₂ , C ₃ Of these, even if one of the attenuations is large, only the closed auxiliary tank 152 does not function, and there is no influence on the others. Then, the spring constant can be reduced as the number of juxtapositions increases. Thus, in the series connection, the attenuation functions in parallel, and therefore, for the sake of simplicity, assuming that the values of the attenuation coefficients C ₁ , C ₂ , and C ₃ are the same (C = C ₁ = C ₂ = C ₃ ). , C / 3. On the other hand, in parallel connection, the attenuation functions in series, so that the attenuation can be expressed as 3C = C ₁ + C ₂ + C ₃ . Therefore, in the parallel connection, the volume ratio between the air spring 150 and the auxiliary tank 152 can be easily adjusted by changing the combination of the auxiliary tanks 152.

  FIG. 4 is an explanatory diagram for explaining the influence of the vibration applied to the slab 110 on the floor structure 130. In FIG. 4, the horizontal axis represents the vibration frequency, and the vertical axis represents the vibration transmissibility. Referring to FIG. 4, when the auxiliary tanks 152 are connected in parallel, the pressure loss is reduced and the amount of attenuation is reduced (1/2 times) compared to the case where the auxiliary tanks 152 are connected in series. Therefore, although the peak of the vibration transmissibility increases twice, it can be understood that the vibration transmissibility becomes small with respect to the vibration of a relatively high frequency. By doing so, the degree of freedom for adjusting the amount of attenuation by the throttle of the communication pipe 154 and the oil damper 156 increases.

  Moreover, since the amount of attenuation becomes small (because the attenuation effect by the communication pipe can be maintained), it is possible to further increase the auxiliary tank 152, and increase the apparent volume and reduce the spring constant by the amount of the additional auxiliary tank 152. Can do. In addition, since elbows are not frequently used inadvertently, the amount of attenuation does not increase unexpectedly, and the fluctuation range of the entire amount of attenuation can be estimated, and the amount of attenuation by the throttle of the communication pipe 154 and the oil damper 156 can be estimated. The adjustment becomes easier.

  In addition, here, an example is shown in which vent holes are provided as many as the number of auxiliary tanks 152 connected to the air spring 150. However, the present invention is not limited to this, and one vent hole is provided in the air spring 150 as shown in FIG. Only 150a may be provided. In this case, the communication pipe 154 extends from the vent hole 150a and further branches into a plurality of parts, thereby communicating the air spring 150 and the plurality of auxiliary tanks 152a, 152b, 152c with each other. Even with such a configuration, the same effect can be expected when a plurality of vent holes are provided.

(Another example of connecting the air spring 150 and the auxiliary tank 152)
FIG. 5 is an explanatory diagram showing the positional relationship between the air spring 150 and a plurality of auxiliary tanks 152 (indicated by 152a, 152b, 152c, and 152d in FIG. 5). In FIG. 5, as in FIG. 2B, the air spring 150 is provided with one vent 150a, and the communication pipe 154 communicates the air spring 150 and the plurality of auxiliary tanks 152a, 152b, 152c with each other. Further, in the example of FIG. 5, the air spring 150 is further provided with a vent 150d, and the communication pipe 154 communicates the vent 150d and one auxiliary tank 152d.

Here, the diameter of the vent 150a is different from the diameter of the vent 150d. Specifically, vent 150a is sized to obtain the damping effect of optional communication pipe 154 (e.g., diameter 13mm or less, the area 130 mm ² or less) is composed of, vent 150d is greater open area than the vent 150a It is set (for example, a diameter of 25 to 35 mm, an area of 490 to 960 mm ² ), and is configured so as not to affect the pressure loss relatively. The diameter ratio between the vent 150a and the vent 150d is larger than 1 and smaller than 4, and the area ratio is larger than 1 and smaller than 16. This is based on the fact that the attenuation caused by reducing the opening area works as the fourth power of the diameter ratio when turbulent flow is assumed.

  In this way, the auxiliary tanks 152a, 152b, and 152c can have an apparent volume, and the auxiliary tank 152d can be captured integrally with the air spring 150. As described above, it is desirable that the total volume of the auxiliary tank 152 be three times or less than the volume of the air spring 150. However, since the auxiliary tank 152d can be regarded as having substantially increased the volume of the air spring 150, The total volume of the auxiliary tanks 152a, 152b, and 152c can be allowed up to three times the total volume of the air spring 150 and the auxiliary tank 152d. Therefore, it is possible to increase the degree of design freedom.

  In addition, the number of auxiliary tanks 152 (auxiliary tank 152d) for increasing the substantial volume of the air spring 150 is not limited to three as long as the number of auxiliary tanks 152 provided continuously for the purpose of obtaining a damping effect is one. The arrangement of the vent holes 150a and 150d in the air spring 150 is not limited to the illustrated position.

  As described above, in the seismic isolation device 120 described above, the damping effect by the communication pipe can be maintained with a simple configuration in which the auxiliary tanks 152 are connected in parallel, and the auxiliary tank can be used effectively, thereby improving the seismic isolation effect. It becomes possible.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  INDUSTRIAL APPLICATION This invention can be utilized for the seismic isolation apparatus which reduces a ground motion and protects a floor structure effectively.

DESCRIPTION OF SYMBOLS 100 ... Seismic isolation system 110 ... Slab 120 ... Seismic isolation apparatus 130 ... Floor structure 150 ... Air spring 150a, 150b, 150c, 150d ... Ventilation hole 152 ... Auxiliary tank 154 ... Communication pipe 156 ... Oil damper 158 ... Relative displacement detection part 160 ... Air pressure control unit 162 ... Air source 164 ... Servo valve

Claims (5)

An air spring confined to the building slab and floor structure;
A plurality of auxiliary tanks communicating with the air spring through a communication pipe;
With
The seismic isolation device, wherein the plurality of auxiliary tanks are connected in parallel to the air spring.   The seismic isolation device according to claim 1, wherein the communication pipe communicates a plurality of vent holes provided in the air spring with the plurality of auxiliary tanks.   The seismic isolation device according to claim 2, wherein at least one of the plurality of vent holes has an opening area larger than that of the other vent holes.   The seismic isolation device according to claim 3, wherein an area ratio of the one vent hole to the other vent hole is larger than 1 and smaller than 16. 5.   5. The communication pipe is connected to the air spring and the plurality of auxiliary tanks, respectively, by extending from a vent hole provided in the air spring and branching into a plurality of the communication pipes. The seismic isolation device according to any one of the above.

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