JPH09287277A - Origin return device for base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation device easily damping vibrations in a short time, preventing the acceleration applied to an upper base from being increased, capable of reducing the total spring constant, capable of improving the base isolation performance, and capable of being manufactured with a simple mechanism at a low cost. SOLUTION: This origin return device is provided with a lower base 210 installed on the floor surface, an upper base 220 displaceable in the vertical direction Z against the lower base face 210a in parallel with the lower base face 210a, an X-link mechanism 230 provided between the lower base 210 and the upper base 220 and supporting the upper base 220 displaceably in the vertical direction Z, an elastic origin return mechanism 240 elastically exciting the upper base 220 upward to return the upper base 220 displaced in the vertical direction Z to the origin position set in advance against the lower base 210, and a tensile spring set 241 connected to the terminal end section 250b of a wire rope 250 at one end hook section 241a and hooked on one end section (right end section) of the lower base 210 at the other hook section 241b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device capable of avoiding damage to an installation by cutting off vibration energy from the outside due to an earthquake or the like.

[0002]

2. Description of the Related Art Conventionally, various types of seismic isolation devices have been known for supporting fragile works of art, antiques, or precision instruments that require protection against external vibrations such as earthquakes. Has been. As one of such seismic isolation devices, for example, Japanese Utility Model Laid-Open No. 62-7794 or JP-A-6-
There is one as described in Japanese Patent No. 33583. This type of seismic isolation device supports the installation on the fixed side of the foundation such as the ground or the floor of the building through the vertical / horizontal damping mechanism, and the vibration energy of the earthquake or the like input from the fixed side of the foundation is supported by the vertical damping mechanism. It has a structure for absorbing and isolating by vertical (vertical) damping motion or horizontal damping mechanism horizontal damping motion.

A seismic isolation device equipped with a vertical damping mechanism includes a lower stand installed on a floor surface and the like, and an upper stand which is parallel to the lower stand surface and is displaceable in a direction perpendicular to the lower stand surface. A compression spring (vertical spring) provided between the lower table and the upper table and a shock absorber composed of a damper provided between the lower table and the upper table are provided.

[0004]

However, in the conventional seismic isolation device described above, the spring constant of the compression spring must be increased when the load of the installation or the like is large. As described above, when the spring constant of the compression spring is increased, there is a problem that it is difficult to be damped forever. If the viscous damping coefficient of the damper is increased in order to solve this problem, the acceleration acting on the upper table will be increased this time, which will eventually cause a serious problem of damaging the installed object. In addition to this, there is a problem in that the spring height dimension of the compression spring cannot be set long due to the above configuration, and the fluctuation of the spring force due to the reciprocating displacement of the upper table is large.

Therefore, the first object of the present invention is to make it possible to set the spring length long without making it difficult to attenuate forever and not increasing the acceleration acting on the upper table. The spring constant as can be reduced and seismic isolation performance can be improved,
Another object of the present invention is to provide an origin return device for seismic isolation devices that can be manufactured at low cost with a simple mechanism.

In addition to this, a second object of the present invention is to attach a two-dimensional seismic isolation table capable of performing a damping motion in a horizontal plane to provide vertical seismic isolation and horizontal seismic isolation. The purpose is to provide a three-dimensional seismic isolation table that can simultaneously perform In particular, in a two-dimensional seismic isolation table, the origin return spring used for the elastic return means in the horizontal damping mechanism corresponding to the horizontal direction in the X direction and the front and rear direction in the Y direction in the horizontal plane is used only in the pulling direction. It is also an object of the present invention to obtain a new origin-returning device that does not cause the above-mentioned problem and can obtain a stable spring force that is not affected by the fluctuation of the displacement.

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 comprises an upper base and a lower base, and the upper base is vertical with respect to the lower base in a horizontal direction. In a seismic isolation device that can be displaced, a support means for supporting the upper table with respect to the lower table and an elastic member arranged substantially horizontally for returning the upper table to an origin position neutral with respect to the lower table. It has a returning means and a displacement transmitting means for transmitting the vertical movement displacement of the upper table to the elastic returning means.

According to a second aspect of the present invention, in the origin restoring device for the seismic isolation device according to the first aspect, the elastic restoring means comprises a coil spring, and the adjusting means adjusts the spring length of the coil spring. The feature is that the damping coefficient can be adjusted.

According to a third aspect of the present invention, in the origin restoring device for seismic isolation device according to the first or second aspect, the displacement transmitting means comprises a pulley and a rope.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in each drawing, in order to simplify the drawing, each component may be appropriately omitted from the configuration of an apparatus, a unit, and the like. In addition, components that are configured in a pair in the figure and do not need to be particularly distinguished and described,
From the viewpoint of simplifying the explanation, one of them will be described as appropriate to substitute for the explanation, and if it is easier to understand with a special distinction, duplicate reference numerals will be given even if they have the same configuration. , Will be attached separately.
When describing the shapes of constituent parts and the positions where they are arranged, each side in the X direction, which is one direction, is referred to as the left side and the right side.
Each side in the Y direction orthogonal to the direction is sometimes referred to as the front side (the diagonally left upper side in each figure is the front side) and the rear side (the diagonally right lower side in each figure is the rear side).

FIG. 1 shows the overall structure of a seismic isolation device according to an embodiment of the present invention (hereinafter referred to as "first embodiment"). In both figures, reference numeral 200 indicates a seismic isolation device. This seismic isolation device 200 includes a lower base 210 installed on a floor surface and a lower base surface 2 which is an upper surface of the lower base 210.
An upper base 220 which is displaceable in a vertical direction Z which is a direction perpendicular to a lower base surface 210a while keeping parallel to 10a.
And provided between the lower base 210 and the upper base 220,
The X-link mechanism 230 as a support means for supporting the upper base 220 so as to be displaceable in the vertical direction Z, and the displacement base 220 which is displaced in the vertical direction Z are set to a predetermined neutral origin position with respect to the lower base 210. Upper stand 22 for returning
Elastic origin return mechanism 240 for elastically urging 0 upward
Mainly consists of and.

Lower base 210 and upper base 2 as described above
The seismic isolation device 200 including 20 and the like is commonly referred to as a vertical seismic isolation table. The size of the lower base 210 is
The four sides of the outer frame are formed to have a size of about 1 m and form a square in a plan view. An installation object (see FIG.
(Not shown in the figure). In addition,
Examples of the above-mentioned installation include a glass display case in which works of art such as sculptures are stored.

The above-mentioned components and members will be described in detail below with reference to FIGS. 4 and 5 in which the same configurations are illustrated in detail. The lower base 210 is installed / fixed to the floor surface 59 via a well-known adjuster 64 having a screw mechanism as shown in FIG. 4, and by operating the screw mechanism of the adjuster 64, the lower base 210 is moved relative to the floor surface 59. The height of the lower base surface 210a is adjusted in the vertical direction Z. The lower base 210 includes a lower base member (not shown in detail) made of, for example, a square steel pipe in a 1 m square outer frame, and a reinforcing member (not shown in detail not shown) made of the same material and shape as the lower base member. ) Is arranged inside the outer frame, and is fixed by welding between the end portions of the respective members.

The upper base 220 has an inner frame 221 framed in a square shape in a plan view, a reinforcing member 222 arranged inside the inner frame 221, and extends in parallel with the X direction at a central portion in the Y direction. The reinforcing frame 223 is fixed to face each other. The inner frame 221 is made of a steel plate, and is bent and formed to have an L-shaped cross section. The edge portions at the four corners of each inner frame 221 are cut at 45 degrees in a plan view and joined by welding. The reinforcing member 222 is made of equilateral angle steel and is fixed to the inner side of the inner frame 221 by welding. Both ends of the reinforcing frame 223 are fixed by welding to the lower surface wall of the inner frame 221 and the inside of the reinforcing member 222 at the center in the Y direction.

Outside the upper base 220, an outer frame 225, which is shown in phantom in FIG. 1, is erected on the lower base surface 210a. The outer frame 225 is made by appropriately bending steel plates and is stacked at four corners and fastened with bolts, nuts, screws (both not shown), and the like.
It is fixed on a by welding or the like.

The X-link mechanism 230 is one of the well-known parallel link mechanisms in which the upper base 220 moves up and down in parallel with the lower base 210, and the center line CL of the lower base 210 parallel to the X direction (see FIG. (Shown only in FIG. 5) and a center line CL (shown only in FIG. 5) parallel to the X direction in the upper pedestal 220, and a pair are arranged facing each other in the Y direction. The X-link mechanism 230 has a pair of flat steel links 231 and 231 intersecting each other in an X shape, and is rotatable at a midpoint of the pair of links 231 and 231 through an intermediate pin 232 by a predetermined angle. It is supported. Further, at one end (a right end in FIG. 1 is shown) of each of the pair of links 231 and 231 facing each other in the vertical direction Z, the moving roller lower part 234b is provided.
Also, a moving roller upper portion 234a is rotatably supported via a shaft. In the vicinity of one end of each of the pair of links 231 and 231 facing each other in the vertical direction Z, the lower base surface 210 is provided.
A guide rail lower portion 235b fixed by welding on a and a guide rail upper portion 235a fixed by welding on the reinforcing member 222 of the upper base 220 are respectively provided. The lower guide rail 235b and the upper guide rail 235a are made of steel plates having a U-shaped cross section, and support the lower moving roller 234b and the upper moving roller 234a so that they can roll less. Note that, in FIG. 1, the lower guide rail 235b and the upper guide rail 235a on the rear side are not shown. The lower moving roller 234b and the upper moving roller 234a have the same structure as the wheel 93A used in the modified example of the wheel in the second embodiment to be described later, and common parts are achieved.

On the other hand, in the vicinity of the other ends of the pair of links 231 and 231 facing each other in the up-down direction Z (the left end is shown in FIG. 1), the bottom of the pin bracket fixed on the lower base surface 210a by welding. 237b and a pin bracket upper portion 237a fixed to the reinforcing member 222 of the upper base 220 by welding.
Are provided respectively. One end of a pair of links 231 and 231 facing each other in the up-down direction Z is rotatably supported by a predetermined angle via a pin 233 loosely fitted in each through hole of the lower pin bracket 237b and the upper pin bracket 237a. .

Therefore, in the X-link mechanism 230, one end of each of a pair of links 231 and 231 facing each other in the vertical direction Z is connected to one end of each of the lower base 210 and the upper base 220 so as to be reciprocally movable. The other ends of the pair of links 231 and 231 facing each other in the direction Z are swingably connected to the other ends of the lower base 210 and the upper base 220, respectively.

With the above structure, the X link mechanism 230
Has a function of supporting the upper base 220 so as to be displaceable in the vertical direction Z, absorbs and attenuates part of vibration energy in the vertical direction Z input from the lower base 210 side, and lowers the lower base 210 and the upper base 210. Since a pair is arranged on both the left and right sides of the base 220, it also has a function of reliably restraining the rolling and rotation of the upper base 220 caused by horizontal plane vibration energy in the X direction and / or the Y direction. In addition, since a pair of X link mechanisms 230 are arranged on both the left and right sides of the lower base 210 and the upper base 220, the vertical direction Z of the upper base 220 is reduced.
The displacement of is highly accurate.

The elastic origin return mechanism 240 includes a lower base 210.
Center line CL parallel to the X direction at (shown only in FIG. 5)
And a pair of the upper pedestals 220 are arranged symmetrically with respect to a center line CL (only shown in FIG. 5) parallel to the X direction in the Y direction.

The elastic origin returning mechanism 240 has the above-mentioned function, that is, the upper base 220 for returning the upper base 220 which is displaced in the vertical direction Z to a predetermined neutral origin position with respect to the lower base 210. In addition to the function of elastically urging upward, the X link mechanism 2 from the lower base 210 side.
It also has a function of absorbing and attenuating vibration energy in the vertical direction Z input via 30.

The elastic origin return mechanism 240 includes a lower base 210.
Between the upper base 220 and the lower base 210
Pulleys 245 and 246 as pulleys that are rotatably provided on the lower base 210 at the other end (the left end is shown in the drawing) and pulleys that are rotatably provided on the upper base 220 side. 247 as an example, and a starting end portion 25 at the other end portion (the left end portion is shown in the drawing) of the upper base 220.
0a is hooked, and the end portion 250b is hooked on each pulley 2
A wire rope 250 as a cord that is routed in the up-and-down direction Z via 47, 246, and 245, and one end locking portion 2 thereof.
41a is coupled to the terminal end portion 250b of the wire rope 250, and the other end locking portion 241b is locked to one end portion (the right end portion is shown in the drawing) of the lower base 210, and a tension spring set 241 as an elastic return means. It is mainly composed of

Each of the pulleys 245 and 246 has a lower base 210.
Pulley bracket 249 fixed on the upper side (see FIGS. 5 and 6).
(Shown only in) is rotatably supported via a shaft,
On the other hand, the pulley 247 is rotatably supported by a pulley bracket 249 (shown only in FIGS. 4 and 5) fixed to the outer frame 225 via a shaft. Wire rope 250
Is made of ordinary steel having flexibility and low permanent elongation.

As described above, the displacement transmitting means for transmitting the vertical movement displacement of the upper base 220 to the tension spring set 241 is composed of the pulleys 247, 246, 245 and the wire rope 250.

The tension spring set 241 is arranged by being stretched over two inter-spring pulleys 248 which are rotatably supported on the lower base 210 via a screw shaft 214. The tension spring set 241 includes three tension springs 241-1, 241-2, 241-made of coil springs having the same spring constant.
3 are connected and combined in series substantially horizontally in the X direction on the lower pedestal surface 210a. Tension spring 241
The connecting portions of -1, 241-2 and 241-3 are formed of flexible wires (not shown), and the wire portions are wound around the inter-spring pulleys 248. Therefore, the tension spring set 241 has a dimension longer than the distance between the lower base 210 and the upper base 220 at the origin position in the vertical direction Z.

The total spring load of the tension spring set 241 is such that the upward elastic biasing force applied to the upper base 220 by the elastic origin return mechanism 240 is equal to the load of the installation including the upper base 220. The balance is maintained and the balance is set so as to be balanced at the predetermined origin position in the vertical direction Z.

In the vicinity of the other end locking portion 241b of the tension spring set 241, a spring locking cover 217 is provided which is movable on the lower base surface 210a on one end side of the lower base 210 in parallel with the X direction. . The spring locking cover 217 is made of a steel plate and is formed in a U-shaped cross section. Spring lock cover 2
A spring locking member 218 is fixedly provided on the inner wall of 17, and the other end locking portion 241b of the tension spring set 241 is locked to the spring locking member 218 described above. The spring locking cover 217 is provided at the position of the center line CL of the lower base 210 and at a position symmetrical with respect to the center line CL, and three spring locking position adjusting screws inserted from the lower inner wall of the outer frame 225. 21
9 and a spring locking cover 217 screwed to the screw 219.
The length of the spring in the X direction can be adjusted via a nut provided inside. On the other hand, on the upper surface of the spring locking cover 217, slide grooves 216 (only shown in FIG. 6) are formed at two symmetrical positions with respect to the center line CL of the lower base 210. Each slide groove 216 is inserted from above into the lower base 21.
Screws 219A that are screwed into 0 and hold the position of the spring locking cover 217 in the vertical direction Z are provided.

As described above, the adjusting means for adjusting the spring length of the tension spring set 241 is the spring locking cover 21.
7, spring locking member 218, spring locking position adjusting screw 21
9, the nut (not shown), the slide groove 216 and the screw 219A. Then, by rotating the spring locking position adjusting screw 219 of the adjusting means for adjustment, the tension spring set 241 together with the spring locking cover 217 becomes X-shaped.
Since the spring length of the tension spring set 241 is adjusted by moving in the direction, the damping coefficient related to the tension spring set 241 set by the weight of the installed object can be adjusted.

Since the adjusting means is constructed as described above, it is necessary to remove the cover (not shown) provided on the outer frame 225, but the spring locking position of the adjusting means is adjusted from the outside of the device unit. By adjusting the screw 219, there is an advantage that the above-mentioned damping coefficient can be easily adjusted without disassembling the device unit.

As described above, the locking piece 224 of the upper base 220 is
The wire starting end 250a is locked to the pulleys 245,
A wire rope 250 is routed through 246 and 247, a terminal end portion 250b of this wire is coupled to one end locking portion 241a of a tension spring set 241, and a plurality of tension springs 241-1, 241-2, 241-3. Is connected and combined in series between the respective spring-to-spring pulleys 248, it is possible to lengthen the spring length of the tension spring set 241 as a whole. As a result, each tension spring 2
Even if the spring constants of 41-1, 241-2, and 241-3 are set to be large, the spring constant of the tension spring set 241 as a whole can be set to be small, and the spring constant can be set freely. It is easy to take a degree. Therefore, vibration energy in the vertical direction Z is input to the lower base 210 due to an earthquake or the like, which causes the upper base 220 to move in the X direction.
When it is reciprocally displaced in the up-and-down direction Z while maintaining a parallel state to the lower base surface 210a via the link mechanism 230,
The extension springs 241-1 and 241-2 should not be affected by the expansion and contraction displacement of the springs corresponding to the reciprocating displacement.
2, 241-3 are expanded and contracted and the total tension of the tension spring set 241 is stably applied as an upward elastic biasing force to the upper base 220, while the upper base 220 is moved to the origin position. Can be restored.

Therefore, according to this first embodiment,
The total spring constant can be reduced by making it possible to set the spring length longer without making it difficult to damp for a long time or increasing the acceleration acting on the upper table. It is possible to provide a seismic isolation device that can be manufactured at low cost with a simple mechanism. And the tension spring set 2
Since it is possible to reduce the total spring constant of 41, it is possible to prevent resonance of the upper base 220 including a so-called installation object. Further, since the upper base 220 is pulled up from above by the tension of the tension spring set 241 via the wire rope 250 arranged on the pulley 247, it is possible to prevent vibration or shaking in the vertical direction Z such as an earthquake. In response to this, it is possible to return to the original position while performing a damping motion in the vertical direction Z in response.

The X-link mechanism 230 is not limited to the above-described arrangement state, but the layout of the elastic origin return mechanism 240 is devised so that the lower base 210 and the upper base 220 can be arranged.
By arranging a pair on both front and rear sides in addition to the left and right sides, that is, arranging on four surfaces, the displacement of the upper base 220 in the vertical direction Z may be made more accurate.

The elastic return means is not limited to the tension spring set 241 described above, but rubber or a combination of tension spring and rubber may be used. Further, a viscous damping means such as a damper may be combined and added to these. From the viewpoint of durability and reliability, environment resistance, assembling workability, maintainability, and cost, it is preferable to use a tension spring. Further, the elastic return means and the X-link mechanism 2 as will be described later.
In combination with 30, the elastic return means may be a compression spring.

In the first embodiment, only the fixed pulley is used as the pulley forming the displacement transmitting means, but the invention is not limited to this, and if the moving pulley (moving pulley) is used, the upper base 2 can be used.
It is possible to cope with a larger change ratio between 20 and the spring extension.

FIG. 2 shows another modification 1 of the first embodiment. In addition, in each drawing referred to in each embodiment and each modification described below, the X-link mechanism 230 and the like are shown as a model in order to simplify the drawing, and the X-link mechanism 230 is a lower base. It is arranged on both front and rear sides of 210 and the upper base 220.

Modification 1 shown in FIG. 2 is different only in that a seismic isolation device 201 is provided instead of the seismic isolation device 200 of the first embodiment. The seismic isolation device 201 is different from the elastic origin return mechanism 240 of the seismic isolation device 200 in that each of the pulleys 245, 246, and 246.
247, pulleys 248 between springs, and wire rope 250
And an elastic origin return mechanism 240A that elastically biases the upper base 220 upward in order to return the upper base 220 to the preset neutral position relative to the lower base 210. Be different.

The elastic origin return mechanism 240A has, for example, two tension springs 241A-1 and 241A-2 connected in series.
It is composed of a combined tension spring set 241A, and both ends of this tension spring set 241A are locked to the lower side of the pair of links 231 and 231. And the tension spring set 241A
Is longer than the distance between the lower base 210 and the upper base 220 at the origin position in the vertical direction Z. Even in the seismic isolation device 201 having such an elastic origin returning mechanism 240A, the seismic isolation device 201 in the vertical direction Z conforms to the first embodiment, even if it is not so effective as the first embodiment. Can perform seismic isolation operation. If it is desired to make the extension spring set 241A longer, for example, two extension springs 241A-1 and 24
A pulley may be arranged between 1A-2 to construct the same idea as in the first embodiment.

The modification 2 shown in FIG. 3 is different only in that a seismic isolation device 203 is provided instead of the seismic isolation device 200 of the first embodiment. The seismic isolation device 203 elastically moves the upper base 220 upward in order to return the elastic origin returning mechanism 240 of the seismic isolation device 200 to a neutral origin position preset with respect to the lower base 210. The main difference is that it has an elastic origin return mechanism 240C that urges to.

The elastic origin return mechanism 240C has a compression spring 24 instead of the tension spring set 241 of the elastic origin return mechanism 240.
Having two is the main difference. Then, one end locking portion of the compression spring 242 is attached to a spring locking piece 243a planted above the lower base surface 210a, and the other end locking portion of the compression spring 242 is slidable on the lower base surface 210a in the X direction. The members are respectively locked to the members 243b. Therefore,
The compression spring 242 has one end fixed to the spring locking piece 243a and the other end wound around a guide rod 244 that is loosely fitted into the slide member 243b, so that the compression spring 242 can expand and contract between the spring locking piece 243a and the slide member 243b. It is located in. The slide member 243b is supported so as to be movable in the X direction within a guide groove 210b formed in the upper portion of the lower base surface 210a. With such a structure, the compression spring 242 has a dimension longer than the distance between the lower base 210 and the upper base 220 at the origin position in the vertical direction Z. Even in the seismic isolation device 203 having such an elastic origin returning mechanism 240C, the seismic isolation device 203 in the vertical direction Z according to the first embodiment is used even if it is not so effective as the first embodiment. Those skilled in the art can easily understand that the seismic isolation operation can be performed.

A second embodiment of the present invention is shown in FIGS. 4 to 6, reference numeral 301 denotes the seismic isolation device of the second embodiment. The seismic isolation device 301 includes a fixed base installed on the fixed side of the foundation such as a floor surface, a first movable base and a second movable base that are provided by being superposed on the fixed base.
Of one of the movable table and the second movable table is a seismic isolation device that should support the installation, and the first movable table is the X direction that is one direction in a plane parallel to the fixed table. The second movable base is movable in a direction orthogonal to one direction.
A first damping unit, which is movable between the first movable table and the first movable table, is provided between the fixed table and the first movable table to reciprocate the first movable table in one direction. A second damping unit, which is provided between the second movable table and the second movable table, for reciprocating the second movable table in the orthogonal direction, and the first movable table and the second movable table with respect to the fixed table. 2D 3 with a new structure including an origin return mechanism for returning to an origin position preset by
One of the features is that it has a multi-stage seismic isolation table 50.

The seismic isolation device 301 is different from the seismic isolation device 200 of the first embodiment in that the two-dimensional three-stage seismic isolation base 50 from which the installation object is removed is installed between the floor surface 59 and the seismic isolation device 200. The only difference is that it is arranged between them. In a strict expression, as shown in FIGS. 4 and 5, the lower frame of the two-dimensional three-stage seismic isolation stand 50 is installed on the floor surface 59, and the installation object is removed to remove the two-dimensional three-stage system. At the upper part of the upper frame 80 of the base isolation table 50, the lower table 2
When the lower part of the seismic isolation device 200 from which 10 is removed is provided,
Alternatively, as shown in FIG. 6, the lower frame of the two-dimensional three-stage seismic isolation base 50 is installed on the floor surface 59, and the upper frame 80 of the two-dimensional three-stage seismic isolation base 50 with the installation material removed. There are two cases, that is, the case where the lower base 210 is superposed and the seismic isolation device 200 is provided. Therefore, in the following, in order to avoid a redundant expression in the embodiment and the modified examples shown in FIG. 6 as a model, the latter case is illustrated, but as an expression including both cases described above, the “lower part” is used. The upper frame 80 is substantially integrally provided on the lower portion of the table 210, "and will be described simply except for special cases.

The seismic isolation device 301 in the latter case as shown in FIG. 6 has a lower base 210 and an upper frame 80.
Although it is disadvantageous in terms of weight because it has a duplicated structure, the seismic isolation device 200 and the two-dimensional three-stage seismic isolation base 50, which are unitized respectively, may be simply combined and coupled by fastening means. However, it may be convenient in terms of handling the device.

In other words, the seismic isolation device 301 is a two-dimensional three-stage seismic isolation stand 5 in which the seismic isolation device 200 is installed on the floor 59.
0 has a configuration provided on the second movable table, and the upper table 220
The installation object 209 is installed and supported on the upper surface of the.
Such seismic isolation device 301 is commonly called a three-dimensional three-stage seismic isolation base.

The structure and operation of the two-dimensional three-stage seismic isolation table 50 will be described in detail below. 7 and 8 show the overall structure of the two-dimensional three-stage seismic isolation table 50 (hereinafter referred to as the "first embodiment of the two-dimensional three-stage seismic isolation table"). The two-dimensional three-stage seismic isolation base 50 in the first embodiment of the two-dimensional three-stage seismic isolation base 50 is a lower frame 60 as a fixed base installed / fixed on the foundation fixed side such as the ground or the floor of a building. And a middle frame 70 as a first movable base that is movable on the lower frame 60 and is movable in the X direction, which is one direction, in a plane parallel to the lower frame 60. An upper frame 80 serving as a second movable base that is movable in the Y direction orthogonal to the first frame, and a first frame that is provided between the lower frame 60 and the middle frame 70 and that reciprocally attenuates the middle frame 70 in the X direction. Damping means 90, middle frame 70 and upper frame 8
Second damping means 91 provided between the upper frame 80 and the lower frame 60 to reciprocate the upper frame 80 in the Y direction, and the middle frame 70 and the upper frame 80 with respect to the lower frame 60. It is mainly configured by an origin return mechanism 100 for returning to (shown by X in the figure).

Each of the lower frame 60, the middle frame 70, and the upper frame 80 has four sides of its outer frame formed to have a size of about 1 m, and has a square shape in a plan view. An installation object (not shown) is placed on the upper frame 80. Examples of the above-mentioned installations include a glass display case in which works of art such as sculptures are stored.

As shown in FIG. 8, the origin returning mechanism 100 includes a middle frame origin returning mechanism 101 for returning the middle frame 70 to the origin position Np with respect to the lower frame 60, and an upper frame for the lower frame 60. The upper frame origin returning mechanism 102 for returning 80 to the origin position Np. Middle frame origin return mechanism 101
Has a pair of first tension springs 103 and 10 as first elastic return means, both ends of which are locked so as to be displaceable in the X direction.
3 and first locking means (described later) for locking each of the first tension springs 103, 103 so as to be displaceable in the X direction. The upper frame origin return mechanism 102 has a pair of second tension springs 104, 104 as second elastic return means whose both ends are locked so as to be displaceable in the Y direction, and the respective second tension springs 104, 104. Second locking means (described later) for locking 104 so as to be displaceable in the Y direction.

The first locking means is the first tension spring 103.
First spring hooking members 105a and 105b as a pair of displaceable first locking members that lock both ends of
A pair of first spring hook members 105 provided on the lower frame 60
Groove 1 for movably supporting a and 105b
07c are formed on the lower springs 107a and 107b as a pair of fixed base locking pieces and a pair of first spring hook members 105a and 105b provided on the lower surface of the middle frame 70 facing the lower frame 60. First spring receiving upper portions 108a, 108 as a pair of first movable base lower engaging pieces in which grooves 108c for respectively movably supporting each are formed.
b.

The second locking means is the second tension spring 104.
Second spring hooking members 106a and 106b as a pair of displaceable second locking members that lock both ends of
A pair of second spring hook members 106 provided on the middle frame 70
Groove 1 for movably supporting a and 106b.
09c are formed respectively, and second spring receiving lower portions 109a and 109b as a pair of first movable base upper locking pieces and a pair of second movable spring lower portions 109a and 109b provided on the lower surface of the upper frame 80 facing the middle frame 70 are provided.
A second spring receiving top 110a as a pair of second movable base locking pieces, in which grooves 110c for movably supporting the spring hooking members 106a, 106b, respectively, are formed.
And 110b.

First and second tension springs 103 and 104
Have the same spring specifications regarding dimensions such as the spring constant, the number of turns, the free length and the maximum allowable tensile length. As best shown in FIG. 8, the first and second tension springs 103 and 104 have the first and second tension springs 103 and 104 via the first and second locking means, respectively. When installed between the lower frame 60 and the middle frame 70 and between the middle frame 70 and the upper frame 80, respectively, the first and second tension springs 103, 10 are attached.
The free length of 4 is set to be at least shorter than the mounting dimension between the first and second locking means. That is, the first and second tension springs 103 and 104 have their initial tensions in a state where the middle frame 70 and the upper frame 80 are completely overlapped with the lower frame 60 and occupy the origin position Np. Are attached to each of the tension springs 103 and 104 in a tensioned state against the tension of the tension springs 103 and 104.

As shown in detail only in FIG. 14, the first spring hooking members 105a and 105b and the second spring hooking members 106a and 106b are made of long flat steel and have the same shape and size. There is. First spring hanging member 105
a, 105b and second spring hook members 106a, 106b
In each of the above-mentioned grooves 107c, 108c, 109c, 1
A pair of notches a for engaging with 10c are formed at symmetrical positions with respect to the center in the longitudinal direction. The first spring hooking members 105a, 105b and the second spring hooking members 106a, 106b are formed at the ends of the first and second tension springs 103, 104 at the center position in the length direction. A locking hole b for hooking the hook portion is opened.

First spring receiving lower parts 107a, 107b, first
Spring receiving upper 108a, 108b, second spring receiving lower 109
a, 109b and second spring receiving tops 110a, 110b
As shown in detail only in FIG. 13, is made of steel for machine structural use, and each part has the same size and shape. First
Lower spring bearings 107a, 107b, first upper spring bearing 108
a, 108b, second spring receiving lower portions 109a, 109b, and second spring receiving upper portions 110a, 110b, each groove 107.
In the openings of c, 108c, 109c, 110c, the first
A large chamfer c is provided for fitting the notches a of the spring hooking members 105a and 105b and the second spring hooking members 106a and 106b with a margin.

The first spring receiving lower portions 107a and 107b and the first spring receiving upper portions 108a and 108b are respectively provided in the grooves 107c and 1c.
The opening side of 08c is integrally attached to each of the upper surface of the lower frame 60 and the lower surface of the middle frame 70 by welding as will be described later in a state in which the spine is turned to the origin position Np in the X direction. Similarly, the second spring receiving lower portions 109a and 109b and the second spring receiving upper portions 110a and 110b are provided in the respective grooves 109c and 1c.
The opening side of 10c is integrally attached to each of the upper surface of the middle frame 70 and the lower surface of the upper frame 80 by welding as will be described later in a state in which the spine is turned to the origin position Np in the Y direction.

First damping means 90 and second damping means 9
1 includes a rail 92 and wheels 93 shown in FIGS. 9 to 11.

The constituent members and constituent parts of the lower frame 60, the middle frame 70 and the upper frame 80 will be described in detail below. As shown in detail in FIG. 9, the outer frame of the lower frame 60 has a total of four lower frame members 61 that extend in the Y direction and the X direction and are arranged to face each other, and are framed in a square shape in a plan view. Has been formed. The edge portions at the four corners of each lower frame member 61 are cut at 45 degrees in a plan view and joined by welding. Inside the outer frame, two lower frame reinforcing members 65 are arranged in parallel with the Y direction at substantially the same intervals. Both ends of each lower frame reinforcing member 65 are arranged to face each other in the X direction.
Each of the inner wall surfaces of No. 1 is joined by welding. The four lower frame members 61 are manufactured in the same shape and size, and are made of square steel pipes having a closed cross-sectional shape. The two lower frame reinforcing members 65 are also manufactured with the same shape and size, and are made of square steel pipes having the same sectional shape and size as the lower frame member 61.

Inside the four corners of the lower frame member 61, support reinforcing members 63 each having a triangular shape in plan view are attached by welding. Each support and reinforcement member 63 has a screw hole 63a for an adjuster. Each support reinforcement member 6
3, adjusters 64 are provided below the adjusters 64. The adjusters 64 are screwed into the screw holes 63a for adjustment so that the height of the lower frame 60 can be adjusted with respect to the floor. Has become.

Between the lower frame member 61 disposed on the front side in the Y direction, which is the diagonally upper left side in the figure, and the two lower frame reinforcing members 65 disposed in the central portion, a cover made of a rectangular steel plate is provided. The lock member 152 is joined by welding. The locked member 152 is formed with a locking hole 152a into which a locking pin (not shown) that configures an inner frame locking device 150, which will be described later, is selectively inserted and removed.

A pair of wheel support members 62 made of unequal angle steel are fastened to the upper surfaces of a pair of lower frame members 61 extending in the X direction and facing each other in the Y direction by screws 55.
On the outside of each wheel support member 62, four wheels 93 are rotatably supported and arranged at equal intervals.

The wheels 93, as shown in detail in FIG.
Body part 9 that rolls due to sliding friction with the engagement surface of rail 93
3b and a vertical flange portion 93a that protrudes from the engagement surface with the rail 92 for preventing the positional displacement in the axial direction, and is integrally formed with a flanged cylindrical shape. The wheels 93 are made of carbon steel for machine structural use.
The wheel 93 has two rolling bearings 97 inside the hollow cylinder.
And a collar 96 between the mounting surface of the wheel support member 62 and the rolling bearing 97 arranged on the right side in the figure, and the nut 95 is screwed onto the axle 94 having the screw formed. By doing so, the wheel supporting member 62 is assembled. The body portion 93b is provided on the surface of the vertical flange portion 93a.
A taper (not shown) whose tip is slightly inclined to the right side in the drawing is formed so that the angle formed with the outer peripheral surface of the is slightly obtuse. As described above, in the first embodiment, axial displacement can be prevented only by the vertical flange portion 93a formed on only one side of the wheel 93, and flange portions are formed on both side portions of the wheel as in the conventional case. It is not necessary to form the structure, which contributes to cost reduction.

The wheels are not limited to the above-mentioned wheels 93, but so-called oiles bearings 97A as shown in FIG.
A wheel 93A that adjusts the rolling friction resistance by using (indicated by a mesh pattern in the figure) may be used. In FIG.
Reference numeral 93Ab indicates a body portion of the wheel 93A. This wheel 9
If 3A is used, when it has a function equivalent to that of the wheel 93 described above, the outer diameter dimension and the like of the wheel 93 can be made smaller and the size can be reduced. Further, since the rolling resistance is increased due to the smaller wheel diameter, it can serve as a friction damper.

Two rubber stoppers 66 are attached to the upper surfaces of a pair of lower frame members 61 extending in the Y direction and facing each other in the X direction with screws. The two stoppers 66 are the inner frame 7
When 0 reciprocates a predetermined amount of displacement in the X direction, it comes into contact with a hitting metal fitting (described later) attached to the lower surface of the middle frame 70, whereby the middle frame 7 with respect to the lower frame 60
The relative displacement amount of the reciprocating motion of 0 is regulated. In the case of the first embodiment, the specifications of the origin returning mechanism 100 and the like in the two-dimensional three-stage seismic isolation table 50 are designed so that the stopper 66 and the above-mentioned hitting metal will not contact until the shaking of an earthquake with a seismic intensity of 7 or more. .

On the upper surfaces of the pair of lower frame members 61 extending in the Y direction and facing each other in the X direction, the center lines (not shown) in the length direction of the pair of lower frame members 61 facing each other in the Y direction are arranged. At the symmetrical positions, a pair of lower first spring bearings 107a and a pair of lower first spring bearings 107b are integrally attached by welding.

As shown in detail in FIG. 10, the outer frame of the middle frame 70 has a pair of rail support members 78 extending in the X direction and arranged to face each other, and a pair of rail supporting members 78 extending in the Y direction to face each other. The pair of arranged middle frame members 71 are formed by being framed in a square shape in a plan view. Each end of each middle frame member 71 is
It is joined and fixed to the inner flange portion of each rail support member 78 by welding.

Each rail support member 78 is made of a bending member having a substantially U-shaped cross section, and is manufactured in the same shape and size. Each rail support member 78 is assembled such that the long side flange portion of both flange portions in the cross section faces toward the outside of the outer frame, and the short side flange portion faces toward the inside of the outer frame. A rail 92 that engages with a wheel 93 arranged on the lower frame 60 side is attached to the upper surface of the inner wall of each rail support member 78 with a plurality of screws 55. The rail 92 is made of flat steel having a rectangular cross section. On the inner wall surface of the long side flange portion of each rail support member 78,
An L-shaped lateral flange member 98 as shown in detail in FIG. 12 (shown by phantom lines in FIG. 10 because it is attached after assembly) is fastened with a plurality of screws 57. The lateral flange member 98 is provided over the entire length of each rail support member 78 so as to face each rail 92 across each wheel 93 arranged on the lower frame 60 or the like, and is arranged in the vertical direction Z.
It has a function of preventing positional deviation from each wheel 93. The horizontal flange member 98 includes a lower frame 60 and an inner frame 70.
When assembled as shown in FIG. 8, the size and shape thereof are set so that the gap between the lower surface of each wheel 93 arranged on the lower frame 60 and the lower surface is about 2 mm.

Thus, each wheel 9 in the vertical direction Z
By providing the lateral flange member 98 having a relatively simple shape in order to prevent the positional displacement from the vehicle 3, the positional displacement from the respective wheels 93 in the vertical direction Z can be prevented reliably and at low cost. You can In addition, a vertical flange portion 93a formed on the wheel 93 side and a horizontal flange member 9 to be attached later
8 together, the adjustment work of the rail 92 and the wheel 93 in the X direction, the Y direction, and the vertical direction Z can be performed only by adjusting the contact surface of the rail 92 with respect to the wheel 93. It is possible to eliminate the need for complicated and highly accurate adjustment work.

Inside each rail support member 78, a pair of middle frame reinforcing members 75 are assembled by welding so as to be back-to-back with the outer wall surface of the short side flange portion of the rail support member 78. The middle frame reinforcing member 75 is made of a bending member having a U-shaped cross section, and has the same height dimension as the short side flange portion of the rail supporting member 78.

Each middle frame member 71 is made of a bending member having the same U-shaped cross section as the middle frame reinforcing member 75. Inside each of the middle frame members 71, two middle frame reinforcing members 75 are arranged in parallel with the X direction at substantially the same intervals. Both ends of each of the above-described four middle frame reinforcing members 75 are partially overlapped with the inner wall surface of each middle frame member 71 and joined by welding.

The middle frame member 71 arranged on the left side in the drawing
And two middle frame reinforcing members 7 arranged in the center of the middle frame 70.
A locked member 153 made of a rectangular steel plate is disposed between the lock members 153 and 75. The three side edges of the locked member 153 partially overlap the flange ends of the middle frame member 71 and the lower surfaces of the flanges of the two middle frame reinforcing members 75, 75 and are fixed by welding. The locked member 153 is formed with a locking hole 153a into which a locking pin (not shown) that constitutes an upper frame locking device 151 described later is selectively inserted and removed.

Two middle frame reinforcing members 7 arranged in the central portion
A contact metal fitting 7 for selectively engaging with a stopper 66 provided on the lower frame 60 side is provided at a substantially central portion of the lower surface of the 5, 75.
Two 7 are attached symmetrically via screws (not shown).

A lock mounting member 154 made of a rectangular steel plate is fixed by welding between the two middle frame reinforcing members 75, 75 arranged on the front side in the Y direction. A lock device 150 for a middle frame, which is schematically shown, is arranged at a substantially central portion of the lock mounting member 154. Locking device 1 for this middle frame
50 has the same structure as the locking device 25 shown in FIG. 9 of Japanese Utility Model Application Laid-Open No. 4-13846 previously proposed by the applicant of the present application, for example, and is shown in the same figure. The engagement pin 25b is engaged with the engagement hole 152 on the lower frame 60 side by the on / off operation of the normally excited solenoid 25d.
It is adapted to be selectively inserted into or removed from a. That is, the middle frame locking device 150 has a function of holding the middle frame 70 at the origin position Np with respect to the lower frame 60 and releasing the held state.

On the upper surface of the pair of middle frame members 71 opposed to each other in the X direction, a pair of wheel support members 72 formed of the same material and having the same shape and size as the wheel support members 62 provided on the lower frame 60 are screw 55. Have been concluded respectively. On the outside of each wheel support member 72, four wheels 93 are rotatably supported and arranged at equal intervals.

A pair of rail supporting members 7 facing each other in the Y direction
Two stoppers 76 are symmetrically attached to the upper surface of 8 via screws (not shown). Two
The individual stoppers 76 are formed of the same shape and size and of the same material as the two stoppers 66 provided on the lower frame 60. These stoppers 76 come into contact with a contact metal fitting (not shown) attached to the lower surface of the upper frame 80 when the upper frame 80 reciprocates in the Y direction by a predetermined displacement amount. Upper frame 80 for 60 and middle frame 70
The relative amount of reciprocating displacement of the is regulated.

The lower surfaces of the pair of middle frame members 71 extending in the Y direction and facing in the X direction are symmetrical with respect to the longitudinal centerlines (not shown) of the pair of middle frame members 71. In position 2
The first set of first spring bearings 108a and the second set of first spring bearings 108b are integrally attached by welding.

On the upper surfaces of the pair of rail supporting members 78 extending in the X direction and facing in the Y direction, the pair of rail supporting members 7 are provided.
The second pair of lower spring bearings 109a and the second pair of lower spring bearings 109b are integrally welded to each other at positions symmetrical with respect to a center line (reference numeral etc. not shown) in the length direction of 8 Is attached to.

As shown in detail in FIG. 11, the outer frame of the upper frame 80 has a pair of rail support members 88 extending in the Y direction and arranged to face each other, and a pair of rail supporting members 88 extending in the X direction to face each other. The pair of upper frame members 81 thus arranged are framed and formed in a square shape in a plan view. Each end of each upper frame member 81 is abutted against the inner flange portion of each rail support member 88 and joined by welding.

Each rail support member 88 is made of the same material as the rail support member 78 of the middle frame 70 and has the same shape and dimensions. Each rail support member 88 is assembled such that the long side flange portion of both flange portions in the cross section faces toward the outside of the outer frame and the short side flange portion faces toward the inside of the outer frame. A rail 92 that engages with each wheel 93 arranged on the side of the middle frame 70 is attached to the upper surface of the inner wall of each rail support member 88 with a plurality of screws 55. On the inner wall surface of the long side flange portion of each rail support member 78, a horizontal flange member 98 indicated by an imaginary line is provided with a plurality of screws 57 (see FIG. 1).
(Shown only in 2). Lateral flange member 98
The size and shape are set so that when the upper frame 80 is assembled to the middle frame 70 as shown in FIG. 8, the gap between the lower surface of each wheel 93 arranged in the middle frame 70 is about 2 mm. And will be retrofitted.

Inside each rail support member 88, a pair of upper frame reinforcing members 85 are assembled by welding so as to be back-to-back with the outer wall surface of the short side flange portion of the rail support member 88. The upper frame reinforcing member 85 is made of the same material as the middle frame reinforcing member 75,
And they are manufactured with the same shape and dimensions.

Each upper frame member 81 is made of the same material as the middle frame member 71 and has the same shape and dimension. Mounting plates 82 are attached by welding to the insides of the four corners where both ends of each upper frame reinforcing member 85 are abutted against each upper frame member 81. Each mounting plate 82 has a screw hole (not shown) for mounting the installation object. Inside the upper frame member 81 near the center, two upper frame reinforcing members 85 are arranged in parallel with the Y direction at substantially the same intervals. Both ends of each of the four upper frame reinforcing members 85 described above are connected to the respective upper frame members 81.
Are partially overlapped with the inner walls of the upper and lower flanges and joined by welding.

Two upper frame reinforcing members 8 arranged in the central portion
At the central portion of the lower surface of 5, 85, two contact fittings for selectively engaging with the stopper 76 provided on the side of the middle frame 70 are symmetrically attached via screws (both not shown). Has been.

In the figure, the lower surface of the reinforcing plate 89 arranged on the left side and the upper frame reinforcing member 8 arranged near the center of the upper frame 80.
A lock attachment member 1 made of a rectangular steel plate is provided between the lock attachment member 1 and
55 is fixed. One end of the two sides of the lock attachment member 155 is attached to the outer wall surface of the upper web of the upper frame reinforcing member 85, and the other end is attached to the lower surface of the reinforcing plate 89 by welding. A lock device 151 for the upper frame, which is schematically shown, is provided at a substantially central portion of the lock attachment member 155. The upper frame locking device 151 has the same configuration as the middle frame locking device 150, and has a function of holding the upper frame 70 at the origin position Np with respect to the middle frame 70 and releasing the held state. Have.

Further, the two-dimensional three-stage seismic isolation table 50 has
A seismic device (not shown) is attached. The seismic sensing device detects a vibration such as an earthquake and outputs a signal, and the middle frame locking device 150 and the upper frame locking device 151, which are normally in a locked state, receive a signal from the seismic sensing device. The lock state is released based on the operation.

On the lower surfaces of the pair of upper frame members 81 extending in the X direction, two pieces are assembled at positions symmetrical with respect to the center line (not shown) of the upper frame members 81 in the length direction. The second spring receiving upper portion 110a and the second set of second spring receiving upper portions 110b are integrally attached by welding.

The pair of rail support members 88 forming the outer frame of the upper frame 80, the pair of upper frame members 81, and the four upper frame reinforcing members 85 are assembled so that their upper surfaces are flush with each other. , The upper surfaces of the mounting plates 82 and the pair of mounting plates 89 are
It is assembled so as to be located on the same plane, which is lower than the position on the same plane by the plate thickness. Although not shown, the upper surface of each member forming the upper frame 80 has
A plurality of screw holes and the like for attaching the installation object are opened.

As described above, the lower frame 60, the middle frame 70, and the upper frame 80 are made up of many common members and common parts, and the constituent members and the common parts are made common.

Next, with reference to FIG. 8, a method of assembling the two-dimensional three-stage seismic isolation table 50 will be briefly described. The lower frame 60, the middle frame 70, and the upper frame 80 that are respectively assembled as described above.
First, each rail in the rail support member 78 disposed on the front and rear sides of the middle frame 70 on each wheel 93 disposed on the front and rear sides of the lower frame 60 in the Y direction. As shown in FIG. 8, 92 is engaged, and the middle frame 70 is superposed and assembled on the lower frame 60. Next, the pair of first spring hook members 1
Two first spring sets 103S in which both ends of the first tension spring 103 are locked to 05a and 105b are prepared. The first set of the first spring set 103S is set as follows. First, each groove 107c of the pair of first spring receiving lower portions 107b arranged on the lower frame member 61 on the right side,
The notches a of the other first spring hooking member 105b are engaged with the respective grooves 108c of the pair of first spring receiving members 108b arranged on the right middle frame member 71. Then, from the gap between the lower frame member 61 on the left side and the middle frame member 71 on the left side, one of the first springs is applied against the spring force (tension) of the first tension spring 103 by a dedicated tool or the like. Member 105a
By pulling, the respective grooves 107c of the first spring receiving lower portion 107a of the two pieces arranged on the lower frame member 61 on the left side, and the first spring receiving piece of the two pieces arranged on the middle frame member 71 on the left side. Top 10
8a to each groove 108c, one first spring hooking member 10
Engage each notch a of 5a. Similarly to the above, the second set of the first spring set 103S is set.

Then, the rails 92 arranged on both the left and right sides of the upper frame 80 are engaged with the wheels 93 arranged on the left and right sides of the middle frame 70 as shown in FIG. The upper frame 80 is superposed on 70 and assembled. Then, the second spring set 104S in which both ends of the second tension spring 104 are respectively locked to the pair of second spring hook members 106a and 106b is
Prepare a set. The first set of the second spring set 104S is set as follows. First, each groove 109c of the second pair of second spring bearing lowers 109a arranged on the front rail support member 78 and the second pair of second spring bearing uppers 110a arranged on the front side upper frame member 81. The notches a of the second spring hooking member 106a on one side (the front side in the figure) are engaged with the respective grooves 110c. Then, this time, from the gap between the rear side rail support member 78 and the rear side upper frame member 81, a second tool is used against the spring force (tension) of the second tension spring 104 by a special tool or the like. By pulling the spring hook member 106b, each groove 109c of the second pair of second spring receiving lower portions 109b arranged on the rear rail supporting member 78 and the rear upper frame member 81.
The notches a of the other second spring hooking member 106b are engaged with the respective grooves 110c of the pair of second spring receiving upper portions 110b arranged at. Similarly to the above, the second set of the second spring set 104S is set.

In the first embodiment of the two-dimensional three-stage seismic isolation table, the first spring set 103S and the second spring set 10 are used.
Since there are two sets of 4S each, for example, the first spring hooking members 105a of the two sets, the first spring hooking members 105b of the two sets, or the second spring hooking members 10 are included.
Of course, it is possible to connect the six springs 6a and the second spring hooking members 106b to each other in the lengthwise direction to make one, but there is an advantage that workability in setting is improved as compared with such a case. The two-dimensional three-stage seismic isolation table 50 can of course be assembled in the reverse order.

Although the first spring set 103S and the second spring set 104S are denoted by different reference numerals, they are common parts having the same size and shape, and are commonly used.

Next, the operation will be described with reference to the schematic views of FIGS. First, at a normal time when vibration energy such as an earthquake is not input to the seismic isolation device 50, the middle frame 70 and the upper frame 80 are moved to the lower frame 60 by the locking operation of the middle frame locking device 150 and the upper frame locking device 151. On the other hand, it is in a fixed / locked state and is stably held at the origin position Np.

On the other hand, when a two-dimensional plane vibration energy exceeding a certain level is input from the lower frame 60 side due to an earthquake or the like, first, the seismic sensing device moves to the middle frame locking device 1.
A signal is sent to the lock device 150 for the upper frame and the lock device 151 for the upper frame, and the lock devices 150, 15 in the locked state as described above
The lock release operation 1 is performed, whereby the middle frame 70 and the upper frame 80 shift to a free state in which they can be moved in the respective set directions. The middle frame 70 and the upper frame 80 are 2
Reciprocal damping motion is started in each of the X and Y directions corresponding to the direction of the dimensional plane vibration.

The X-direction component of the two-dimensional plane input vibration energy component is absorbed by the reciprocating damping motion of the first damping means 90 in the X direction, and the tension of the pair of first tension springs 103, 103 is increased. While returning to the origin position Np by the origin returning operation described later, the Y direction component of the two-dimensional plane input vibration energy component is absorbed by the reciprocating damping motion of the second damping means 91 in the Y direction, A pair of second tension springs 10
The origin position Np is restored by the origin returning operation described later by the tension of 4, 104. In this way, the absorption of all vibration energy is carried out smoothly and reliably. Further, during the origin return operation, a part of the X-direction component and the Y-direction component of the two-dimensional plane input vibration energy component is included in each of the first tension springs 103 and 103 and each of the second tension springs 10.
It is also absorbed during the return-to-origin operation of 4,104.

Here, the origin return operation of the first tension spring 103 and the second tension spring 104, which is a feature of the first embodiment of the two-dimensional three-stage seismic isolation table, will be described in detail. In order to simplify the explanation of the operation, there is one first tension spring 103 and one second tension spring 104 as shown in FIG. 16, and as shown in FIGS. A case in which 60 moves in the X direction will be modeled and described. In addition,
For convenience of illustration, the left and right first spring receiving bottoms 107a, 1
The mounting position of the 07b with respect to the lower frame 60 is the first on both the left and right sides.
The spring bearings 108a, 108b (shown by hatching in the figure) are shown to be inside the mounting position with respect to the middle frame 70 (shown by hatching in the figure), but this is only on the model illustration. Therefore, the lower frame 60 and the middle frame 70 do not interfere with each other regardless of whether they are located inside or outside.
It suffices that they are arranged at symmetrical positions with respect to the center line parallel to the X direction. This relationship is based on the second lower spring receiving members 109a and 109b and the second upper spring receiving members 110a and 110b.
The same applies to b.

The state shown in FIGS. 16 and 17 is the inner frame 70.
The upper frame 80 and the upper frame 80 occupy the origin position Np with respect to the lower frame 60, and the balance is maintained by the spring force (tension) of the first tension spring 103. At this time, each notch a of the first spring hooking member 105a on the left side is formed in the lower frame 60.
Each groove 107c of the first lower spring receiving portion 107a on the left side of
And the groove 108c on the left side first spring receiving upper portion 108a of the middle frame 70, respectively, and the right side first spring receiving upper portion 108a.
Each notch a of the spring hooking member 105b has a groove 107c on the right first spring bearing lower 107b of the lower frame 60 and a groove 10 on the right first spring bearing upper 108b of the middle frame 70.
8c and the first tension spring 103, respectively.
Since the initial tension is applied, the strain due to the weight of the first tension spring 103 is removed and the tension is always maintained.

From this state, when the lower frame 60 swings to the right in the X direction and moves to the right by the movement amount xa with respect to the middle frame 70 as shown in FIG. In some cases, the middle frame 70 may move relative to the lower frame 60 in the left direction in the X direction by the amount of movement xa). While being disengaged from 107a, the left first spring hooking member 105a is engaged and locked only with the left first spring bearing top 108a of the middle frame 70. At the same time, the right first spring retaining member 105b is disengaged from the right first spring bearing upper 108b of the middle frame 70, and the right first spring retaining member 105b is lower than the right first spring bearing lower 107b of the lower frame 60. Only engaged and locked.
As a result, the tension due to the extension of the first tension spring 103 by the movement amount xa acts on the middle frame 60, so that the middle frame 60 is pulled to the right side and the origin position Np.
Try to return to.

Contrary to the above operation, as shown in FIG. 19, when the lower frame 60 swings to the left in the X direction and moves to the left by the movement amount xb with respect to the middle frame 70 (the middle frame 70 is the lower frame). 6
0 relative to 0 in the right direction by the amount of movement xb), the left first spring hook member 105
While a is disengaged from the left first spring bearing upper 108a of the middle frame 70, the left first spring hooking member 105a is engaged only with the left first spring bearing lower 107a of the lower frame 60. At the same time, the right first spring hooking member 10
5b is a first spring receiving lower portion 107b on the right side of the lower frame 60.
At the same time, the right side first spring hooking member 105b is engaged only with the right side first spring receiver top 108b in the middle frame 70. As a result, the tension due to the extension of the first tension spring 103 by the movement amount xb acts on the middle frame 60, and the middle frame 60 is pulled to the left side and tries to return to the origin position Np. .

Even when the lower frame 60 moves in a swinging manner in the front-back direction in the Y direction with respect to the upper frame 80, it is obvious that the same operation as described above will occur only by changing the operation direction. The description is omitted.

As shown in FIG. 16, the origin returning action can be achieved by using only one origin returning tension spring. In order to operate the tension return spring for return to origin as stably and reliably as possible, the first step of the two-dimensional three-stage seismic isolation table
It is desirable to provide at least two each symmetrically in the X direction and the Y direction as in the embodiment of FIG. When the home return tension spring is arranged in this manner, the spring constant can be set smaller than that of the case where only one spring is used, so that the operation / workability when setting the home return tension spring is improved. There is also an advantage that can be done.

Therefore, the seismic isolation device 20 of the first embodiment.
According to the seismic isolation device 301 in which the first embodiment of the two-dimensional three-stage type seismic isolation block is added to 0, in addition to the above advantages of the seismic isolation device 200, the first tension spring 103 and the second tension spring 104
In the state where the middle frame 70 and the upper frame 80 respectively occupy the origin position Np, the initial tension is applied respectively, and the first tension spring 103 and the second tension spring 104 described above. By acting like, the spring force (tension) is always used only on the extension side,
There is an advantage of obtaining a highly reliable origin return mechanism 100 which operates stably and surely without being affected by the reciprocating movement of the lower frame 60 with respect to the middle frame 70 and the upper frame 80 while avoiding the occurrence of deflection. .

Further, according to the seismic isolation device 301, in addition to the above-mentioned advantages of the seismic isolation device 200, the first lower spring support 107a,
107b and the first spring receiving tops 108a, 108b are X
Direction, the grooves 107c and 108c are opened with their backs facing toward the origin position Np, and the second spring receiving lower portions 109a and 109b and the second spring receiving upper portions 110a and 1c are provided.
The first spring set 103S and the second spring set 104 are provided by the first spring set 103S and the second spring set 104, since the groove 10c and 110c are opened on the back side with respect to the Y-direction origin position Np.
As the set of S is removable,
You can optionally remove each spring hook member from each spring receiver,
Since each tension spring can be easily replaced, the workability at the time of mounting and removing each tension spring via each spring hooking member can be improved.

According to the seismic isolation device 301, in addition to the advantages of the seismic isolation device 200, the wheels 93 of the first damping means 90 are fixed to the lower frame 60 and the rails 92 are movable to the first. The wheels 93 of the second damping means 91 are provided on the middle frame 70 as a stand, respectively.
In addition, since the rails 92 are respectively provided on the upper frame 80 as the second movable base, the lower frame 60 can be provided only by providing the wheels 93 with the strength of the rail 92 contact surface (horizontal plane). On the other hand, since the relative movement of the middle frame 70 and the upper frame 80 relative to the middle frame 70 can be smoothly performed, respectively, the accuracy of each wheel 93 and the contact surface of the rail 92 during operation can be improved. It does not fall and become unstable or immobile.

Further, for the above-mentioned reason, the required number of each wheel 93 is determined by the conventional seismic isolation device, for example, the actual flat opening 4-1384.
It is possible to reduce the amount of the seismic isolation device by 50 to 60% with respect to the device described in Japanese Unexamined Patent Publication No. 6 or Japanese Patent Laid-Open No. 6-335583, etc., and it is possible to obtain a seismic isolation device with a totally low cost.

In the same manner as shown in FIGS. 4 to 6,
The two-dimensional three-stage seismic isolation table 50 is shown in FIG. 2 and FIG.
Of the seismic isolation devices 201 in Modifications 1 and 2 of the above embodiment,
It goes without saying that it can be arranged and applied mutatis mutandis to 203.

In FIG. 20, reference numeral 302 indicates a seismic isolation device as a modification of the second embodiment. This seismic isolation device 30
In comparison with the seismic isolation device 301 of the second embodiment, 2 is a two-dimensional three-stage seismic isolation base 5 on the upper part of the upper base 220 from which the installation object has been removed.
0 is provided, and the lower frame 60 of the two-dimensional three-stage seismic isolation stand 50 is provided substantially integrally with the upper stand 220. The upper part of the upper base 220 and the lower part of the lower frame 60 are substantially integrally coupled by a fastening means such as a screw or a clamp. The two-dimensional three-stage seismic isolation table 50 is shown in FIG.
In the same manner as shown in Fig. 2, each seismic isolation device 201, 20 in Modifications 1 and 2 of the first embodiment shown in Figs.
Needless to say, it can be arranged and applied mutatis mutandis.

In the second embodiment and its modification,
If it is not necessary to obtain the remarkable effect of the two-dimensional three-stage seismic isolation table 50 shown in FIGS. 7 to 19, instead of the two-dimensional three-stage seismic isolation table 50, for example, actual Kaihei 4-13846. It goes without saying that a two-dimensional three-stage seismic isolation stand as described in Japanese Patent Laid-Open No. 6-33583 or the like may be arranged in the same manner as the above-mentioned embodiments and modifications.

FIG. 21 shows a second embodiment of a two-dimensional three-stage seismic isolation table which is another embodiment of the above-mentioned two-dimensional three-stage seismic isolation table. Further, in FIG. 21, reference numeral 160 denotes a two-dimensional two-stage seismic isolation block unit for constituting the second embodiment of the two-dimensional three-stage seismic isolation block.

This two-dimensional two-stage seismic isolation stand unit 160
As shown in FIG. 21, the middle frame 70 is removed from the two-dimensional three-stage seismic isolation base 50 of the first embodiment of the two-dimensional three-stage seismic isolation base shown in FIGS. The lower frame 60 shown in FIG.
Is engaged with a pair of left and right wheels 93 of the lower frame 60. The seismic isolation base unit 160 is a kind of so-called two-dimensional two-stage seismic isolation base.

As described above, the lower frame 60, the middle frame 70, and the upper frame 80 form a square in a plan view, and these constituent members and constituent parts are made common, and the X passing through the origin position Np. Since the left and right and the front and back are symmetric with respect to the center line in the Y direction and the center line in the Y direction, including the assembling positions of the above-mentioned components and components, there is an advantage that the assembly can be easily performed as described above. Since the set content of the first spring set 103S is clear as described above, its description is omitted.

In the state shown in FIG. 21, the base isolation unit 160 is such that the upper frame 80 can reciprocate only in the Y direction with respect to the lower frame 60. Therefore, it is difficult to perform the base isolation by absorbing the plane input vibration energy in all directions, only by performing the seismic isolation action of the Y direction component of the plane input vibration energy only with this one base isolation table unit 160. However, if no particular effect is desired like the two-dimensional three-stage type base isolation table 50 of the first embodiment of the two-dimensional three-stage type base isolation table, it is of course shown in FIG. 4 to FIG. 6 or FIG. Similarly, the lower frame 60 of the seismic isolation unit 160
And the lower base 210 of the seismic isolation device 200 are substantially integrally disposed on the upper frame 80 of the seismic isolation base unit 160, or the lower frame 6 of the seismic isolation base unit 160 is fastened to the floor 59.
0 may be arranged substantially integrally on the upper base 220 of the seismic isolation device 200.

In FIG. 22, reference numeral 170 indicates a superposition isolation base unit. The overlapped seismic isolation base unit 170 includes two seismic isolation base units 160, and the first seismic isolation base unit 16 is provided.
The upper frame 80, which serves as a movable base in No. 0, is overlapped with the lower frame 60, which serves as a foundation fixing base in the second seismic isolation base unit 160.

In FIG. 23, reference numeral 303 indicates a seismic isolation device as a third embodiment. In this seismic isolation device 303, a superposition isolation base unit 170 is arranged between the floor surface 59 and the lower base 210 of the seismic isolation device 200. That is,
The lower frame 60 of the superposed seismic isolation base unit 170 is provided on the floor surface 59, and the upper frame 80 of the superposed seismic isolation base unit 170 is provided substantially integrally with the lower portion of the lower base 210 of the seismic isolation device 200. .

In FIG. 24, reference numeral 304 indicates a seismic isolation device as a modification of the third embodiment. In a seismic isolation device 304 as a modified example of the third embodiment, a lower portion of a lower frame 60 of a first seismic isolation unit 160 is provided on a floor surface 59, and an upper frame of the first seismic isolation unit 160 is provided. The base 80 is substantially integrally provided on the lower base 210 of the seismic isolation device 200. The lower frame 60 of the second seismic isolation stand unit 160
Is substantially integrally provided on the upper base 220 of the seismic isolation device 200, and the installation object 209 is placed and supported on the upper frame 80 of the second seismic isolation base unit 160.

In FIG. 25, reference numeral 305 represents a seismic isolation device as another modification of the third embodiment. A seismic isolation device 305, which is another modification of the third embodiment, has a superposed seismic isolation base unit 17 on the upper part 220 of the seismic isolation device 200.
It is arranged by superposing 0. The seismic isolation device 305
The upper base 220 of the seismic isolation apparatus 200 is provided substantially integrally with the lower portion of the lower frame 60 at the lowermost portion of the overlapping seismic isolation base unit 170.

In the same manner as shown in FIGS. 4 to 6,
The seismic isolation base unit 160 and the superposition isolation base unit 170
It goes without saying that the seismic isolation devices 201 and 203 in the modified examples 1 and 2 of the first embodiment shown in FIGS. 2 and 3 can be arranged and applied mutatis mutandis.

In FIG. 26, reference numeral 306 indicates a seismic isolation device as a fourth embodiment. In the seismic isolation apparatus 306 as the fourth embodiment, the two-dimensional two-stage seismic isolation stand 1 is arranged between the floor surface 59 and the lower part of the lower stand 210. Two
The two-dimensional two-stage seismic isolation base 1 includes a lower frame 2 as a fixed base installed on the floor surface 59, and an installation object 20 arranged to face the lower frame 2.
An upper frame 3 as an opposed movable base which should support 9; support means arranged between the lower frame 2 and the upper frame 3 for allowing movement of the upper frame 3 with respect to the lower frame 2 in all directions; And an urging means arranged between the upper frame 3 and the upper frame 3 for returning the upper frame 3 after the movement to the first original position before the movement. In the seismic isolation device 306, the lower frame 2 of the two-dimensional two-stage seismic isolation base 1 is arranged on the floor surface 59, and the upper frame 3 of the two-dimensional two-stage seismic isolation base 1 is below the lower base 210. Are provided substantially integrally with each other.

The seismic isolation device 30 according to the fourth embodiment.
However, the seismic isolation device 307 may be a modified example of the fourth embodiment as shown in FIG. 27. Seismic isolation device 30
In FIG. 7, the two-dimensional two-stage seismic isolation base 1 is disposed on the upper base 220, and the lower frame 2 of the two-dimensional two-stage seismic isolation base 1 is substantially integrally formed on the upper base 220. It is provided and configured.

As a concrete example of the two-dimensional two-stage seismic isolation stand 1,
For example, there is a two-dimensional two-stage type seismic isolation table having a rolling type vibration isolation mechanism 5 as shown in FIG. 2 of JP-A-6-33583.

In the same manner as shown in FIGS. 4 to 6,
The two-dimensional two-stage seismic isolation base 1 is used as the seismic isolation devices 201 and 201 in Modifications 1 and 2 of the first embodiment shown in FIGS. 2 and 3.
Needless to say, it can be arranged and applied to No. 03.

The seismic isolation devices 301 to 307 described above are used.
In the two-dimensional three-stage seismic isolation table 50, each of the first and second seismic isolation table units 160, and the overlapping seismic isolation table unit 170 or 2
The two-dimensional two-stage seismic isolation base 1 is installed between the floor surface 59 and the lower base 210 rather than being arranged on the upper side of the upper base 220 in various forms. It is needless to say that it is advantageous from the viewpoint of reducing the load of the vehicle, from the standpoint of the structure of the seismic isolation device, or from the point of quickly returning to the origin during seismic isolation operation.

The fixed base, the first movable base, and the second movable base are the lower frame 60 and the middle frame 70 used in the second embodiment.
Not only the upper frame 80 but also the necessary rigidity, the first movable base is movable in the X direction, which is one direction, in the plane parallel to the fixed base, and the second movable base is X. It has a structure capable of moving in a Y direction orthogonal to the direction, and one of the first movable table and the second movable table has a structure capable of supporting an installation object. For example, a monocoque structure made of sheet metal may be used. Similarly, the movable frame is not limited to the lower frame 60 and the upper frame 80 used in the third embodiment, but has the necessary rigidity and moves in one direction in a plane in which the movable base is parallel to the fixed base. It is only necessary that the movable table has a structure capable of supporting the installation. Further, the shapes of the fixed base, the first movable base, and the second movable base are not limited to the square shapes in the plan view as in the first embodiment, but may be rectangular or circular shapes.

The elastic return means and the first and second
The respective elastic restoring means are not limited to the first and second tension springs 103 and 104 described above, but may be rubber or the like having an elastic tension imparting function or the first and second tension springs 103 and 104.
A combination of rubber and rubber may be used. From the viewpoint of durability and reliability, environment resistance, assembling workability, maintainability, and cost, it is preferable to use a tension spring.

The first attenuating means, the second attenuating means and the attenuating means are not limited to the configurations of the above-described embodiments and the like, and if the above-mentioned advantages of each of the above-mentioned embodiments and the like are not desired, for example, The slip-type vibration isolation mechanism 4 described in JP-A-6-33583 or the like may be used, and a damping means including the rail 92 and the wheel 93 of each of the above-described embodiments may be appropriately combined. Alternatively, a conventionally known damping means may be applied or appropriately combined.

The seismic isolation devices 200, 201, 203,
The materials, surface treatments, heat treatments, and the like of the above-described components and components constituting the seismic isolation devices 301 to 307 are not limited to those described above, and may be appropriately set according to the environment in which the device is used and the needs of users. It goes without saying that it will be designed appropriately.

In addition, the embodiments and examples of the present invention are as follows.
The configuration is not limited to the configurations of the above-described embodiments and the like, and an oil damper or the like may be additionally provided in addition to the above-described configurations as necessary.

Further, it goes without saying that the constituent elements are not limited to the above-described respective embodiments and modified examples, and these constituent elements may be appropriately used in a combination other than the above.

[0124]

As described above, according to the present invention,
With the above configuration, it is possible to reduce the total spring constant by making it possible to set the spring length to be long without being difficult to decay forever and increasing the acceleration acting on the upper table. Thus, it is possible to provide a vertical seismic isolation device which can improve seismic isolation performance and can be manufactured at low cost with a simple mechanism. Since it is possible to reduce the total spring constant, it is possible to prevent the occurrence of resonance.

Further, according to the present invention, various types of two-dimensional seismic isolation bases capable of performing a damping motion in a two-dimensional plane are additionally provided to provide vertical seismic isolation and horizontal seismic isolation. It is possible to provide a three-dimensional seismic isolation table capable of simultaneously performing.

Further, according to the present invention, in addition to the above respective effects, the origin return spring used in the origin return mechanism in the horizontal damping mechanism of the two-dimensional two-stage type or two-dimensional three-stage type base isolation table is pulled in the pulling direction. It is also possible to obtain a new origin-returning mechanism that does not cause deflection and can obtain a stable spring force that is not affected by displacement fluctuations.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a seismic isolation device showing an embodiment of the present invention.

FIG. 2 is a schematic view showing a modified example 1 of the elastic origin returning mechanism in the above embodiment.

FIG. 3 is a schematic view showing a modified example 2 of the elastic origin returning mechanism in the above embodiment.

FIG. 4 is a side sectional view including a partial section of a seismic isolation device showing a second embodiment of the present invention.

FIG. 5 is a plan sectional view showing only the left side, which is symmetrical with respect to the center line of the seismic isolation device according to the second embodiment.

FIG. 6 is a schematic view of a seismic isolation device showing a modification of the second embodiment.

FIG. 7 is a perspective view of a two-dimensional three-stage type base isolation table used in the second embodiment and the like.

FIG. 8 is an exploded perspective view showing an assembled state of a two-dimensional three-stage type seismic isolation stand used in the second embodiment and the like.

FIG. 9 is a perspective view showing a lower frame structure of a two-dimensional three-stage seismic isolation stand used in the second embodiment and the like.

FIG. 10 is a perspective view showing a middle frame structure of a two-dimensional three-stage seismic isolation stand used in the second embodiment and the like.

FIG. 11 is a perspective view showing an upper frame structure of a two-dimensional three-stage type seismic isolation stand used in the second embodiment and the like.

FIG. 12 is a vertical cross-sectional view showing the structure around a rail and wheels used in a two-dimensional three-stage seismic isolation table.

FIG. 13 is a perspective view showing a mounting structure of each spring receiving member used in the two-dimensional three-stage seismic isolation table.

FIG. 14 is a perspective view of each spring hooking member used in a two-dimensional three-stage type base isolation table.

FIG. 15 is a cross-sectional view of a main part of another modified example of the wheel used for the two-dimensional three-stage seismic isolation table.

FIG. 16 is a schematic perspective view for explaining the configuration and operation of the two-dimensional three-stage seismic isolation block by simplifying it as a model.

FIG. 17 is a schematic front view for explaining the operation of the two-dimensional three-stage seismic isolation base in a simplified manner.

FIG. 18 is a schematic front view for explaining the operation of the two-dimensional three-stage seismic isolation base in a simplified manner.

FIG. 19 is a schematic front view for explaining the operation of the two-dimensional three-stage seismic isolation base in a simplified manner.

FIG. 20 is a perspective view of a seismic isolation device showing a modification of the second embodiment.

FIG. 21 is a perspective view of a seismic isolation stand unit used in the third embodiment of the present invention.

FIG. 22 is a perspective view of a polymerized seismic isolation base unit used in the third embodiment.

FIG. 23 is a schematic view of a seismic isolation device showing a third embodiment.

FIG. 24 is a schematic diagram of a seismic isolation device showing a modification of the third embodiment.

FIG. 25 is a schematic diagram of a seismic isolation device showing another modification of the third embodiment.

FIG. 26 is a schematic view of a seismic isolation device showing a fourth embodiment of the present invention.

FIG. 27 is a schematic diagram of a seismic isolation device showing a modification of the fourth embodiment.

[Explanation of symbols]

50 Two-dimensional three-stage seismic isolation table 60 Lower frame as fixed table 70 Middle frame as first movable table 80 Upper frame as second movable table 90 First damping means 91 Second damping means 160 Excluded Shaking table unit 170 Superposition seismic isolation table unit 200, 201, 203, 301, 302, 303, 3
03, 304, 305, 306, 307 seismic isolation device 209 installation object 210 lower table 210a lower table surface 220 upper table 230 X-link mechanism as support means 240 elastic origin return mechanism 241 tension spring set 241a tension spring set as elastic return means One end locking part 241b The other end locking part of the tension spring set 245, 246, 247 Pulley 250 as a pulley constituting the displacement transmitting means Wire rope 250a as a cord constituting the displacement transmitting means 250a As the starting end of the rope Wire start end 251b Wire end as wire end X One direction Y Direction orthogonal to one direction Z Vertical direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Higashizono Michihiko 3-8-1, Kumamoto, Kumamoto, Kumamoto Prefecture

Claims (3)

[Claims] 1. A seismic isolation device comprising an upper base and a lower base, wherein the upper base is vertically displaceable relative to the lower base in a vertical direction, and a support for supporting the upper base with respect to the lower base. Means, elastic return means arranged substantially horizontally for returning the upper base to an origin position neutral with respect to the lower base, and displacement transmission for transmitting vertical movement displacement of the upper base to the elastic return means. An origin returning device for a seismic isolation device, comprising: 2. The elastic return means comprises a coil spring,
The origin return device for a seismic isolation device according to claim 1, further comprising an adjusting unit that adjusts a spring length of the coil spring so that a damping coefficient can be adjusted. 3. The origin returning device for seismic isolation device according to claim 1, wherein the displacement transmitting means comprises a pulley and a rope.