JP2020133152A - Seismic isolator - Google Patents

Abstract

To provide a seismic isolator in which strokes of a plurality of dampers can be secured even when the dampers are coupled together and furthermore the dampers can be surely supported and which is adaptable to movement in two directions within a horizontal plane.SOLUTION: This seismic isolator comprises: a first damper connected at one end to a seismic object side; a second damper connected at one end to an installation surface side; a supporting unit that is connected to the other ends of the first and second dampers and that supports the first and second dampers on the installation surface and moves on the installation surface in accordance with the strokes of the first and second dampers in such a way that the strokes of the dampers become equal to each other; and a connection unit that connects the seismic object to one end of the first damper and slides the first damper with respect to the seismic object in a direction roughly orthogonal to the stroke direction of the first damper within a plane parallel to the installation surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a seismic isolation device that suppresses vibration received by a structure.

In recent years, long-period ground motions (for example, huge earthquakes along the Nankai Trough) and long-period pulse ground motions due to direct earthquakes have occurred, and the danger of long-period large-amplitude ground motions has been pointed out. When a long-period ground motion occurs that is longer than expected, the seismic isolation technology of the building currently under construction may not be sufficient.

For example, when a long-period ground motion occurs, the seismic isolation layer of the seismic isolation structure is greatly deformed and the building collides with the retaining wall, or the building is damaged by the impact acceleration input to the building at the time of collision. There is a risk. In addition, the vibration of long-period ground motion resonates with the vibration of the building, which may cause response amplification in the building and increase the shaking of the building.

Various technologies have been proposed as countermeasures against these assumed damages. For example, in the case of a collision with a retaining wall of a building, there is a technique for alleviating the impact at the time of a collision by installing a cushioning material (see, for example, Patent Document 1 and Patent Document 2).

In addition, it is effective to install a large amount of damping device to suppress large deformation, but in that case, the damping force is too large and a large acceleration is input to the building for a small earthquake. There is. As a countermeasure technique, an oil damper that changes the damping force depending on the displacement has also been proposed (see, for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2014-77229 Japanese Unexamined Patent Publication No. 2016-199910 JP-A-2017-26095

According to the technique described in Patent Document 1 or Patent Document 2, the impact acceleration at the time of collision with the cushioning material can be avoided in the building as a countermeasure using the cushioning material. It will be entered. In addition, after a collision occurs, it is necessary to replace the crushed cushioning material.

According to the technique described in Patent Document 3, the stroke of the oil damper device itself depending on the displacement is 1000 [mm] or less at the maximum, and it may not be applicable to the design in which the clearance is larger than 1 [m]. The maximum speed that the damper can handle is limited to 150 [cm / s], and if an unexpectedly large earthquake occurs, the damper itself may be damaged.

However, in order to solve these problems, in order to secure a stroke against the shaking of the building, for example, if a device in which two ordinary oil dampers are connected in series is used, the length of the main body becomes longer and the weight of the damper itself becomes longer. There is a problem that the piston rod is bent due to the vertical load due to the above and the axial load of the damper, and the oil damper tends to buckle. Further, since the shaking of the building is not limited to one direction in the horizontal plane and may move in two directions, it is necessary to cope with the deformation in two directions.

The present invention has been made in view of the above-mentioned problems, and while ensuring a stroke even when a plurality of dampers are connected without using a special damper, the plurality of dampers are surely supported and in a horizontal plane. It is an object of the present invention to provide a seismic isolation device capable of responding to movement in two directions.

In order to achieve the above object, the present invention is a seismic isolation device that suppresses shaking of the seismic isolation object with respect to the installation surface, and has a first damper whose one end is connected to the seismic isolation object side and one end. The second damper connected to the installation surface side, the other end of the first damper and the other end of the second damper are connected, and the first damper and the second damper are connected to the installation surface. A support portion that supports and moves the installation surface according to the stroke so that the stroke of the first damper and the stroke of the second damper have the same length, the seismic isolation object, and the first damper. With a connecting portion that connects the one end of the above and slides the first damper with respect to the seismic isolation object in a direction substantially orthogonal to the stroke direction of the first damper in a plane parallel to the installation surface. It is a seismic isolation device characterized by being provided with.

According to the present invention, since the support portion for making the stroke of each damper equal in length is provided between the first damper and the second damper connected in series, the damping force of each damper varies. However, it is possible to prevent residual displacement of each damper after expansion and contraction. Further, since the connecting portion provided between the seismic isolation object and the first damper slides the first damper with respect to the seismic isolation object, the force applied in the direction orthogonal to the stroke direction of each damper is released. However, it is possible to prevent contact between the juxtaposed dampers.

The present invention is also characterized in that the support portion moves the installation surface while maintaining the position of the midpoint between one end of the first damper and one end of the second damper. You may.

According to the present invention, when the first damper and the second damper expand and contract, the support portion moves so as to hold the midpoint between the first damper and the second damper connected in series, so that each damper Even if the damping force of each damper varies, the stroke amount of each damper can be made the same length.

The present invention also includes stoppers formed so that the support portion projects upward on both sides of the first damper in the radial direction to regulate movement in the horizontal plane direction orthogonal to the stroke direction of the first damper. It may be configured as follows.

According to the present invention, even when a force is applied in a direction orthogonal to the stroke direction of each damper and the juxtaposed dampers move in the horizontal plane, the stopper regulates the movement of the first damper in the horizontal plane. Therefore, it is possible to prevent the juxtaposed dampers from coming into contact with each other.

The present invention also includes a stretchable link mechanism in which the support portion is formed so that the stroke of the first damper and the stroke of the second damper have the same length, and a gantry that supports the link mechanism. The link mechanism is provided with a main body portion fixed to the gantry, first ball nuts and second ball nuts provided at both ends of the main body portion in the axial direction, and one end side on the seismic isolation object side. A first ball screw that is rotatably connected and the other end side is screwed into the first ball nut, and one end side is rotatably connected to the installation surface side, and the other end side is screwed into the second ball nut and said. It may be configured to include a first ball screw and a second ball screw formed of a reverse screw.

According to the present invention, since the pair of ball screws screwed into the pair of ball nuts at both ends of the main body are formed as reverse screws, an axial force is applied to both ends of the pair of ball screws protruding from the main body. At that time, the pair of ball screws expands and contracts while rotating with respect to the main body. Since the main body is fixed to the frame of the support, the pair of ball screws can be expanded and contracted to the same length with respect to the main body.

The present invention may also be configured such that the other end of the first damper and the other end of the second damper are connected to the gantry.

According to the present invention, since the dampers arranged side by side facing each other are connected to each other on the gantry, the gantry supports the weight of the dampers and makes the stroke amount of each damper equal in length. can do.

The present invention may also be configured to include a plurality of the first dampers and a plurality of the second dampers in the same number as the first dampers.

According to the present invention, since a general-purpose product can be used for each damper, a plurality of dampers can be connected to adjust the damping force and the stroke amount.

The present invention may also be configured to include a moving mechanism that supports the support portion so as to be movable in the stroke direction on the installation surface.

According to the present invention, when the support portion moves in conjunction with the expansion and contraction of each damper, the movement mechanism reduces the friction generated between the support portion and the installation surface, thereby reducing the resistance during expansion and contraction of each damper. It can be reduced.

According to the present invention, the stopper regulates the movement of the first damper in the horizontal plane even when the juxtaposed dampers move in the horizontal plane by applying a force in the direction orthogonal to the stroke direction of each damper. Therefore, it is possible to prevent the juxtaposed dampers from coming into contact with each other.

It is a side view which shows typically the structure of the seismic isolation device which concerns on embodiment of this invention. It is a top view which shows the structure of the seismic isolation device. It is sectional drawing which shows the structure of the support part. It is a front view which shows the structure of the support plate. It is a top view which shows the structure of the link mechanism provided in the support part. It is a side view which shows the operation state of the link mechanism provided in the support part. It is a top view which shows the structure of the seismic isolation device of the comparative example. It is a top view which shows the state which each damper of the seismic isolation device of a comparative example comes into contact with each other. It is a top view which shows the modification of the link mechanism.

Hereinafter, embodiments of the seismic isolation device of the present invention will be described with reference to the drawings.

As schematically shown in FIG. 1, for example, the seismic isolation device 1 is a device that suppresses the shaking that occurs in the seismic isolation object when the installation surface E moves. The seismic isolation object is, for example, a seismic isolation superstructure of a building 2 or the like, and the installation surface E is, for example, a seismic isolation lower structure of a ground surface or a floor surface. The seismic isolation device 1 is provided, for example, in the foundation portion of the building 2. The building 2 is supported by the seismic isolation bearing 3 with respect to the installation surface E. The seismic isolation bearing 3 is formed by alternately laminating plate-like bodies and iron plates made of an elastic body such as rubber, for example.

When an earthquake occurs, the installation surface E is displaced, while the building 2 tries to stay in place due to inertia. Since the seismic isolation bearing 3 flexibly supports the building 2 with respect to the installation surface E, it prevents the shaking of the installation surface E from directly propagating to the building 2 in response to the displacement of the installation surface E in the event of an earthquake. ..

However, when a long-period large-amplitude seismic motion occurs, there is a risk that seismic isolation cannot be achieved with the seismic isolation bearing 3 alone, so a seismic isolation device 1 is provided between the building 2 and the installation surface E. The seismic isolation device 1 includes a seismic isolation portion D for attenuating the shaking of the building 2 and a support portion 30 for supporting the seismic isolation portion D with respect to the installation surface E.

The seismic isolation unit D includes, for example, a pair of first dampers 10 and a pair of second dampers 20. The first damper 10 and the second damper 20 are, for example, general seismic control oil dampers. The first damper 10 and the second damper 20 may have a plurality of dampers connected in parallel. As the first damper 10 and the second damper 20, not only an oil damper but also a shaft resistance type damper such as a viscous damper or an inertial mass damper may be used. The first damper 10 and the second damper 20 are connected in series in order to make the damping force of one damper equal to that of one damper while ensuring a necessary stroke amount for shaking. The first damper 10 includes a cylindrical main body portion 11 and a cylindrical piston rod 12 that can be expanded and contracted from the tip of the main body portion 11.

The first damper 10 and the second damper 20 are installed in a state where the piston rods 12 and 22 are shortened to a position intermediate between the main bodies 11 and 21 and the maximum stroke length. As a result, the first damper 10 and the second damper 20 are installed so as to be expandable and contractible in the stroke direction.

One end 11A of the first damper 10 is the rear end of the main body 11, and the other end 12A of the first damper 10 is, for example, the tip of the piston rod 12. The other end 12A of the first damper 10 is connected to the support portion 30. One end 11A of the first damper 10 is connected to a pedestal 4 provided so as to hang down from the lower surface of the building 2 via a first connecting portion P. As a result, the first damper 10 is connected to the building 2 side, which is the object of vibration control.

As will be described later, the first connecting portion P rotatably connects one end 11A of the first damper 10 to the pedestal 4, and is substantially orthogonal to the stroke direction of the first damper 10 in a plane parallel to the installation surface E. Connect so that it can slide in the direction. The detailed configuration of the first connecting portion P will be described later.

As the second damper 20, for example, the same number of oil dampers as the first damper 10 are used. The second damper 20 is provided with a cylindrical main body 21 and a cylindrical piston rod 22 that can be expanded and contracted from the tip of the main body 21. The other end 22A of the second damper 20 is, for example, the tip of the piston rod 22, and the one end 21A of the second damper 20 is the rear end of the main body 21. One end 21A of the second damper 20 is connected to a pedestal 5 provided so as to project upward from the installation surface E. As a result, the second damper 20 is connected to the installation surface E side.

The other end 22A of the second damper 20 is connected to, for example, a pedestal 5 provided so as to hang down from the lower surface of the building 2 via a second connecting portion Q. The second connecting portion Q rotatably connects the other end 22A of the second damper 20 to the pedestal 5. The detailed configuration of the second connecting portion Q will be described later.

The support portion 30 is placed on the installation surface E via the moving mechanism 31. The moving mechanism 31 slidably supports the support portion 30 in the stroke direction of each damper. The support portion 30 supports the first damper 10 and the second damper 20 with respect to the installation surface E by being connected to the other end 12A of the first damper 10 and the other end 22A of the second damper 20. .. The support portion 30 prevents the first damper 10 and the second damper 20 from bending downward due to their own weight, and also prevents the first damper 10 and / or the second damper 20 from buckling during expansion and contraction.

Next, the detailed configuration of the seismic isolation device 1 will be described. As shown in FIGS. 2 and 3, in the seismic isolation device 1 in a plan view, a pair of first dampers 10 and a pair of second dampers 20 are juxtaposed. The first damper 10 and the second damper 20 are supported via a support portion 30. The distance between the dampers is, for example, about several tens [cm].

When the pair of the first damper 10 and the second damper 20 cannot be connected in series due to the limitation of the space where the seismic isolation device 1 is installed, the pair of the first damper 10 and the second damper 20 are connected to each other on the gantry 40. They are juxtaposed in parallel in opposite directions. The pair of first damper 10 and second damper 20 are connected in a crank shape via a gantry 40, and expand and contract in the same manner as in a state of being connected in series.

The other end 12A of the first damper 10 is, for example, the tip end of the piston rod 12, and the one end 11A of the first damper 10 is the rear end of the main body 11. The other end 12A of the first damper 10 is provided with, for example, a support member 14 (clevis) that is rotatable by pin joining. The support member 14 is fixed to the support portion 30. As a result, the other end 12A of the first damper 10 is rotatably supported in the horizontal plane direction within a predetermined angle range with respect to the support portion 30.

One end 11A of the first damper 10 is provided with, for example, a support member 13 (clevis) that is rotatable by pin joining. The support member 13 is connected to the pedestal 4 via a first connecting portion P described later. As a result, one end 11A of the first damper 10 is rotatably supported in the horizontal direction with respect to the building 2 via the pedestal 4. The support members 13 and 14 may have pin joints that are rotatable around two axes, or may be ball joints.

The first connecting portion P connects the support member 13 to the pedestal 4 so as to be slidable in the horizontal direction (X-axis direction), for example. The first connecting portion P includes, for example, a connecting plate P1 that supports the support member 13, and a linear guide P2 that slidably supports the connecting plate P1. The support member 13 is fixed to the connection plate P1 on one side. For example, the support member 13 of the pair of first dampers 10 is connected to the connection plate P1. The detailed configuration of the connection plate P1 will be described later.

A linear guide P2 is connected to the connection plate P1 on the other side. The linear guide P2 slidably supports a pair of sliders P3 fixed in the vertical direction fixed to the other surface side of the connection plate P1 and a pair of sliders P3, and is parallel to the pedestal 4 in the vertical direction. It is provided with a pair of rails P4 fixed to. The slider P3 has a cross section formed in a "U" shape when viewed from the side in the X-axis direction. A recess is formed in the slider P3, and the rail P4 is fitted in the recess. The slider P3 is slidably supported by the rail P4 in the axial direction in the longitudinal direction of the rail P4.

The slider P3 is formed so as not to fall off from the rail P4 even when a pulling force is applied in the stroke direction of the first damper 10. The slider P3 and the support member 13 are connected by, for example, bolts and nuts. The support member 13 and the first connecting portion P may be welded to each other.

As shown in FIG. 3, a total of eight through holes K1 are formed in the connection plate P1 so that, for example, a pair of support members 13 are connected to both sides by four bolts and nuts. A through hole K2 for connecting one end of the first ball screw 36B, which will be described later, and eight through holes K3 are formed around the through hole K2 in the central portion of the connection plate P1. The through holes K1 to K3 are formed in a substantially elliptical shape (so-called loose hole shape) having a long side in the vertical direction (Z-axis direction).

The support member 13 is attached to the connection plate P1 so that the bolt abuts on the lower portion of the through hole K1. Similarly, one end of the first ball screw 36B, which will be described later, is attached so that the bolt abuts on the upper portion of the through hole K3. The connecting plate P1 is capable of transmitting the shearing force (10 [kN]) calculated from the axial force (2000 [kN]) of each damper × the friction coefficient (0.005) of the linear guide and the axial force. Each damper and the link mechanism 35 are connected by bolts and nuts.

The building 2 is installed on the installation surface E via the seismic isolation bearing 3. Since the seismic isolation bearing 3 is made of an elastic body such as seismic isolation rubber, it is elastically deformed when the load of the building 2 acts for a long period of time and shrinks downward by several [mm] to 20 [mm]. Occurs. When the pedestal 4 is displaced downward due to creep distortion in the building 2, the mounting position of the support member 13 and the mounting position of one end of the first ball screw 36B, which will be described later, can be moved upward.

The other end 22A of the second damper 20 is, for example, the tip end of the piston rod 22, and the one end 21A of the second damper 20 is the rear end of the main body 21 (see FIGS. 2 and 3). The other end 22A of the second damper 20 is provided with, for example, a support member 24 (clevis) that is rotatable by pin joining. The support member 24 is fixed to the support portion 30. As a result, the other end 22A of the second damper 20 is rotatably supported in the horizontal plane direction within a predetermined angle range with respect to the support portion 30.

One end 21A of the second damper 20 is provided with, for example, a support member 23 (clevis) that is rotatable by pin joining. The support member 23 is connected to the pedestal 5 via a plate-shaped second connecting portion Q. The second connecting portion Q is, for example, a plate-shaped body formed in a rectangular shape. The second connecting portion Q is provided between the support member 23 and the pedestal 5 by, for example, through holes (not shown) at the four corners and anchor bolts (not shown) and nuts (not shown) inserted through the through holes. It is sandwiched between the two and fastened together. The support member 23 and the second connecting portion Q may be welded to each other.

As a result, one end 21A of the second damper 20 is rotatably supported in the horizontal direction within a predetermined angle range with respect to the pedestal 5. The support members 23 and 24 may have pin joints that are rotatable around two axes, or may be ball joints.

If the first damper 10 and the second damper 20 are simply connected, when the installation surface E is displaced, a large load is applied to one of the dampers having the lower damping force due to the variation in the damping force of the dampers. Therefore, when the installation surface E is displaced, it is desirable that the strokes of the first damper 10 and the second damper 20 have the same length, and the two dampers expand and contract at the same time. Therefore, the support portion 30 is provided with a link mechanism 35 in the support portion 30 for making the strokes of the first damper 10 and the second damper 20 equal in length when the installation surface E is displaced in the stroke direction.

The support portion 30 includes a gantry 40 provided with a link mechanism 35. The gantry 40 is supported by the moving mechanism 31. The moving mechanism 31 is, for example, a linear bearing. The moving mechanism 31 may be a ball or a roller. The moving mechanism 31 moves the gantry 40 along the stroke direction (Y-axis direction) of the first damper 10 and the second damper 20, for example. The moving mechanism 31 includes a rail 31A installed on the installation surface E and a sliding portion 31B that slides on the rail 31A.

The gantry 40 is movably supported on the installation surface E in the Y-axis direction by the moving mechanism 31. The gantry 40 includes a plate-shaped bottom plate 40A formed in a rectangular shape. On the upper surface of the bottom plate 40A, for example, a first support plate 40B that supports the other end 12A side of the pair of first dampers 10 and a pair of second support plates that support the other end 22A side of the pair of second dampers 20. 40C and is formed.

The first support plate 40B is a rectangular plate-like body that stands up from the upper surface of the bottom plate 40A. A pair of support members 14 are fixed to both sides of the first support plate 40B with a plurality of bolts and nuts. As a result, the first support plate 40B supports the other end 12A of the pair of first dampers 10. A through hole H1 for inserting a link mechanism 35, which will be described later, is formed in the central portion of the first support plate 40B.

The second support plate 40C is a rectangular plate-like body that rises upward from the upper surface of the bottom plate 40A. A support member 24 is fixed to the second support plate 40C with a plurality of bolts and nuts. As a result, the pair of second support plates 40C support the other end 22A of the pair of second dampers 20. The first support plate 40B and the second support plate 40C are arranged so that the first damper 10 and the second damper 20 are connected in a crank shape. The first support plate 40B and the second support plate 40C are arranged so as to be offset in the direction orthogonal to the stroke direction of the first damper 10 and the second damper 20 and face each other.

A stopper 40D that regulates the lateral movement of the first damper 10 is further formed on the upper surface of the bottom plate 40A. The stopper 40D is a plate-like body that protrudes upward from the upper surface of the bottom plate 40A and is formed in a rectangular shape. The stoppers 40D are provided on both sides of the first damper 10 in the radial direction so as to sandwich the first damper 10 at a predetermined distance from the main body 11. The stopper 40D may be formed of an elastic body, or may be a roller having a rotation axis in the Z-axis direction. A fixing member 40F for fixing the link mechanism 35 is further provided on the upper surface of the bottom plate 40A.

Next, the detailed configuration of the link mechanism 35 will be described.

As shown in FIG. 5, the link mechanism 35 includes a main body portion 36 formed in a pipe shape. The central portion 36T of the main body portion 36 is fixed to the central portion of the bottom plate 40A via the fixing member 40F. A first ball nut 36A is attached to one end of the main body 36 on the pedestal 4 side. The other end side of the first ball screw 36B is screwed into the first ball nut 36A along the axis L1 direction of the main body portion 36. One end side of the first ball screw 36B is rotatably connected to the pedestal 4 via the first connecting portion P and the radial bearing B1. The first ball nut 36A and the first ball screw 36B are formed so as to be, for example, a right-hand screw.

When a force is applied to the first ball screw 36B in the axis L1 direction, the first ball screw 36B expands and contracts along the axis L1 direction while rotating with respect to the first ball nut 36A. As a result, the first ball screw 36B can be expanded and contracted with respect to the main body 36.

A second ball nut 36C is attached to the other end of the main body 36 on the pedestal 5 side. The other end side of the second ball screw 36D is screwed into the second ball nut 36C along the axis L1 direction of the main body 36. One end side of the second ball screw 36D is rotatably connected to the pedestal 5 via a support plate R and a radial bearing B2. The second ball nut 36C and the second ball screw 36D are formed so as to be, for example, a 36A, a first ball screw 36B, and a left-hand screw having a reverse screw. The first ball screw 36B and the second ball screw 36D may be formed so as to be opposite screws to each other.

When a force is applied to the second ball screw 36D in the axis L1 direction, the second ball screw 36D expands and contracts along the axis L1 direction while rotating with respect to the second ball nut 36C. As a result, the second ball screw 36D can be expanded and contracted with respect to the main body 36. At the time of installation, the protruding amount of the first ball screw 36B and the protruding amount of the second ball screw 36D are adjusted so as to have the same length. That is, the link mechanism 35 is arranged so that the central portion 36T is in the central position. With the above configuration, the first ball screw 36B and the second ball screw 36D are relatively stretchable.

As described above, the pedestal 40 (support portion 30) is mounted on the installation surface E via the moving mechanism 31, so that when a displacement such that the pedestal 4 and the pedestal 5 are separated from each other occurs, the first The 1-ball screw 36B and the 2nd ball screw 36D extend relatively along the axis L1. At this time, since the central portion 36T of the main body portion 36 is fixed to the gantry 40, the first ball screw 36B and the second ball screw 36D extend so that the stroke amount is equal to that of the main body portion 36.

Similarly, when a displacement such that the pedestal 4 and the pedestal 5 are proximal to each other occurs, the first ball screw 36B and the second ball screw 36D are shortened to the same length with respect to the main body portion 36. At this time, the link mechanism 35 propagates the force from the main body portion 36 to the gantry 40 via the central portion 36T and the fixing member 40F in the displacement direction, and moves the gantry 40 with respect to the installation surface E.

Next, the operation of the support portion 30 will be described.

As schematically shown in FIG. 6, when the installation surface E and the building 2 are relatively displaced, the support portion 30 moves on the installation surface E. When the installation surface E is displaced in the direction in which the pedestal 5 provided on the installation surface E is separated from the pedestal 4 provided on the building 2 from the normal state in which no displacement occurs (see FIG. 6 (1)). 6 (see)), the first ball screw 36B and the second ball screw 36D extend to the same length with respect to the main body 36. At this time, the link mechanism 35 propagates the force from the main body portion 36 to the gantry 40 via the central portion 36T and the fixing member 40F in the displacement direction, and moves the gantry 40 with respect to the installation surface E.

When the pedestal 5 provided on the installation surface E is displaced in the direction proximal to the pedestal 4 provided on the building 2 (see FIG. 6 (3)), the pedestal 40 is interlocked in the same manner as described above. Move with respect to the installation surface E. That is, the link mechanism 35 holds the position of the central portion 36T (midpoint) provided at the midpoint between the first ball screw 36B and the second ball screw 36D, so that the link mechanism 35 is a stand for the first ball screw 36B and the second ball screw 36D. Holds the 40 position.

With such a configuration, the support portion 30 itself moves the installation surface E so that the strokes of the first ball screw 36B and the second ball screw 36D with respect to the gantry 40 are equal in length and according to the stroke.

Further, when the pedestal 4 and the pedestal 5 move relatively in the direction orthogonal to the axis L1 (X-axis direction), the slider P3 of the first connecting portion P slides with respect to the rail P4, and the link mechanism 35 moves. It slides in the X-axis direction relative to the pedestal 4. That is, when the pedestal 4 and the pedestal 5 move relatively in the X-axis direction, the linear guide P2 moves in the X-axis direction to release the force applied in the X-axis direction of the seismic isolation device 1 to the link mechanism 35. , No force is applied in the X-axis direction.

Next, the operation of the seismic isolation device 1 will be described. In the seismic isolation device 1, when the installation surface E is displaced in a direction in which the pedestal 5 provided on the installation surface E is separated from or proximal to the pedestal 4 provided on the building 2, the link mechanism of the support portion 30 is as described above. By the operation of 35, the support portion 30 itself moves the installation surface E according to the stroke so that the strokes of the first ball screw 36B and the second ball screw 36D with respect to the pedestal 40 are equal in length.

At this time, the piston rod 12 of the first damper 10 extends or shortens at the same distance as the stroke of the first ball screw 36B with respect to the gantry 40. Similarly, the piston rod 22 of the second damper 20 extends or shortens equidistantly with the stroke of the second ball screw 36D with respect to the gantry 40. Therefore, due to the operation of the link mechanism 35, the support portion 30 has one end 11A of the first damper 10 and the second damper according to the stroke so that the strokes of the first damper 10 and the second damper 20 have the same length. The installation surface E itself moves while maintaining the position of the midpoint with one end 21A of 20 (see FIG. 6).

The seismic isolation device 1 can always make the displacements of the first damper 10 and the second damper 20 the same by the operation of the link mechanism 35, and even if there are variations in the damping characteristics and the inertial mass of each damper, the piston It is possible to prevent drift (lateral displacement) and residual displacement after expansion and contraction. Since the axial force acting on the first damper 10 and the second damper 20 is due to the difference (variation) in the damping characteristics and the inertial mass of each damper, the difference is small. The variation of each damper is, for example, 10% or less of the damper performance.

Further, when the pedestal 4 and the pedestal 5 move relatively in the X-axis direction, the slider P3 of the first connecting portion P slides with respect to the rail P4, and each damper together with the support portion 30 with respect to the pedestal 4. Relatively slides in the X-axis direction. That is, when the pedestal 4 and the pedestal 5 move relatively in the X-axis direction, no force is applied to each damper in the X-axis direction.

As shown in FIGS. 7 and 8, as a comparative example, in a moving device not provided with the first connecting portion P, when the pedestal 4 and the pedestal 5 are relatively displaced by 1 [m] in the X-axis direction, The pedestal 40 moves half of it in the X-axis direction by 50 [cm]. Then, the juxtaposed first damper 10 and the second damper 20 may be displaced in the oblique direction, and a portion (circled portion in the figure) where the first damper 10 and the second damper 20 interfere with each other may occur.

On the other hand, in the seismic isolation device 1, since the first connecting portion P is provided, the force applied in the direction orthogonal to the stroke direction of each damper is released. As a result, each damper and the link mechanism 35 do not rotate in the horizontal plane, so that the dampers do not collide with each other if they are arranged so as to be separated from each other by about several [cm]. Even if the movement of the first connecting portion P becomes sluggish and the first damper 10 and the second damper 20 are displaced in the oblique direction, the stopper 40D provided on the bottom plate 40A comes into contact with the first damper 10. Since the lateral movement is restricted, interference between the first damper 10 and the second damper 20 is prevented.

When the above-mentioned seismic isolation device 1 is installed in a building, the two seismic isolation devices 1 are arranged in the directions orthogonal to each other in a plan view, so that when large amplitude and high-speed shaking occurs in all plane directions. , The building can be seismically isolated. Further, if the support portion 30 is assembled in advance at the factory, it is only necessary to install each damper on the support portion 30 at the site, shortening the construction period at the site and shaking the building with a large amplitude and high speed (single damper). It can correspond to twice as much as).

As described above, according to the seismic isolation device 1, by connecting the oil dampers in series, the stroke is twice as large as that of the normal oil damper, but the same damping force is provided, and the input speed of the normal oil damper can be supported. It is a device that can be applied when designing a building with a large clearance. Further, according to the seismic isolation device 1, since the first connecting portion P for making the oil damper movable in the direction orthogonal to the stroke direction of the oil damper is provided, the force applied in the direction orthogonal to the stroke direction of the oil damper is released. This prevents the dampers from colliding with each other. Further, according to the seismic isolation device 1, since the loose hole-shaped through holes K1 to K3 are formed in the connection plate P1 of the first connecting portion P, even if the seismic isolation bearing 3 sinks downward, creep distortion occurs. The mounting position of the seismic isolation device 1 in the height direction can be adjusted.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above one embodiment and can be appropriately modified without departing from the spirit of the present invention. For example, as shown in FIG. 9, the link mechanism 35 meshes not only with a ball screw and a ball nut but also with a pair of rack gears W and a pair of rack gears W, and a pinion gear rotatably provided at the center of the bottom plate 40A. It may be composed of X and.

1 Seismic isolation device 2 Building 3 Seismic isolation bearing 4 Pedestal 5 Pedestal 10 1st damper 20 2nd damper 30 Support 35 Link mechanism 36 Main body 36A 1st ball nut 36B 1st ball screw 36C 2nd ball nut 36D 2nd ball screw 36T Central part 40 Stand 40A Bottom plate 40D Stopper D Seismic isolation part E Installation surface P 1st connection part Q 2nd connection part

Claims (7)

A seismic isolation device that suppresses shaking of the installation surface of the seismic isolation object.
The first damper, one end of which is connected to the seismic isolation object side,
A second damper whose one end is connected to the installation surface side,
It is connected to the other end of the first damper and the other end of the second damper to support the first damper and the second damper with respect to the installation surface, and the stroke of the first damper and the first damper. A support portion that moves the installation surface according to the stroke so that the strokes of the two dampers have the same length, and
The seismic isolation target is connected to the one end of the first damper, and the first damper is placed in a plane parallel to the installation surface in a direction substantially orthogonal to the stroke direction of the first damper. It is characterized by including a connecting portion that slides with respect to an object.
Seismic isolation device. The support portion is characterized in that it moves the installation surface while maintaining the position of the midpoint between one end of the first damper and one end of the second damper.
The seismic isolation device according to claim 1. The support portion is provided with stoppers formed so as to project upward on both sides of the first damper in the radial direction to regulate the movement of the first damper in the horizontal plane direction.
The seismic isolation device according to claim 1 or 2. The support portion
A stretchable link mechanism formed so that the stroke of the first damper and the stroke of the second damper have the same length.
A pedestal for supporting the link mechanism, and
The link mechanism
The main body fixed to the gantry and
The first ball nut and the second ball nut provided at both ends in the axial direction of the main body,
A first ball screw whose one end side is rotatably connected to the seismic isolation object side and whose other end side is screwed into the first ball nut.
One end side is rotatably connected to the installation surface side, the other end side is screwed into the second ball nut, and the first ball screw and a second ball screw formed by a reverse screw are provided.
The seismic isolation device according to any one of claims 1 to 3. The gantry is characterized in that the other end of the first damper and the other end of the second damper are connected to each other.
The seismic isolation device according to claim 4. A plurality of the first dampers and a plurality of the second dampers having the same number as the first dampers are provided.
The seismic isolation device according to any one of claims 1 to 5. A moving mechanism for supporting the support portion so as to be movable in the stroke direction on the installation surface is provided.
The seismic isolation device according to any one of claims 1 to 6.

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