JP2002013312A - Base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation device using a rolling support body as a load supporting device which has a damping function and a dust-proof function, of which height is low, and which can be miniaturized. SOLUTION: This base isolation device is provided with a lower plate 11 horizontally installed on a foundation 1, an upper plate 12 horizontally fixed on a lower surface of a structure 5 to face the lower plate 11, plural rolling bodies 13 rollably interposed between the lower plate 11 and the upper plate 12 to support the structure 5, and holding rings 14 provided between the lower plate 11 and the upper plate 12 to enclose the rolling body 13 in such a way that it can roll, and having a damping means 20 to damp movement by the rolling bodies 13.

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 that suppresses a swing of a structure such as a building or a bridge when an earthquake occurs.

[0002]

2. Description of the Related Art In recent years, various seismic isolation devices have been proposed in which a structure such as a building is prevented from swaying when an earthquake occurs, or the sway is reduced to reduce damage. The seismic isolation device has a load support mechanism that stably supports the load of the structure for a long period of time, a damping function to quickly stop shaking during an earthquake, and a structure that moved after the earthquake is returned to its original position. A restoration function or the like is necessary.

As a seismic isolation device, for example, Japanese Unexamined Patent Publication No. Sho 60-2
There is one disclosed in Japanese Patent No. 50142. This seismic isolation device has a sliding structure, a lower plate installed on the ground, an upper plate supporting the structure, and a ring disposed between these and capable of displacing horizontally without contacting the upper plate. When,
Numerous steel balls (bearing balls) held in the ring and rollably interposed between the lower plate and the upper plate
And the like. When an earthquake occurs, the horizontal swing of the ground is absorbed by the rolling of the large number of steel balls to prevent the swing of the structure.

[0004]

By the way, a seismic isolation device using a steel ball (bearing ball) as a rolling bearing for a load supporting device is expected to have a damping function because the rolling friction resistance of the steel ball is extremely small. Can not do. Therefore, it is necessary to separately install dampers such as a history damper of lead or steel, a friction damper, and a viscous damper using oil or viscous material in order to provide a damping function to quickly stop shaking during an earthquake. However, there is a problem that the size is increased and the cost is increased. In particular, in buildings such as ordinary houses, the installation location (including the work space if replacement is necessary in the future), and the labor and cost of construction and maintenance are required, and construction costs increase. There are also problems.

Further, even if dust or the like is deposited on the lower plate as the rolling surface of the steel ball because it is arranged under the floor of the building, it is difficult to remove the dust and the like. Therefore, there are also problems such as a complicated structure and an increase in cost. In addition, there is another problem that the center of gravity of the seismic isolation device is increased and the stability is lacking. The present invention has been made in view of the above points, and in a seismic isolation device using a rolling bearing as a load support device, the seismic isolation device has a damping function and a dustproof function, and has a low height and can be downsized. The purpose is to provide a seismic device.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a lower plate horizontally installed on a foundation and a lower surface of a structure are fixed horizontally opposite to the lower plate. An upper plate, a plurality of rolling elements rotatably interposed between the lower plate and the upper plate and supporting the structure, and the rolling elements interposed between the lower plate and the upper plate. And a holding ring having damping means for damping movement of the rolling element while surrounding the moving element in a freely rolling manner.

According to a second aspect of the present invention, the damping means generates a frictional force between the holding ring and the lower and upper plates. According to the third aspect of the present invention, the holding ring is slidable by contacting the lower surface with the upper surface of the lower plate and the upper surface with the lower surface of the upper plate, respectively, and generates a frictional force on each contact surface. It is characterized by the following.

[0008] In the invention according to claim 4, the holding ring includes:
An upper ring, a lower ring, and an elastic member interposed between the upper and lower rings, and an elastic member that presses the upper surface of the upper ring to the lower surface of the upper plate and presses the lower surface of the lower ring to the upper surface of the lower plate. Features. When the foundation is horizontally displaced due to the earthquake, each rolling element in the retaining ring of the seismic isolation device rolls between the lower plate and the upper plate, and the upper plate is maintained in a substantially stationary state.
In the retaining ring, the upper and lower rings slide on the rolling surfaces of the upper plate and the lower plate, and generate a frictional force (damping force) by an elastic member (claims 2, 3, and 4). As a result, the movement of the rolling elements of the seismic isolation device is attenuated, the shaking stops quickly, and unnecessary movement due to inertia or the like is prevented. Also, the retaining ring
When sliding on the rolling surface, it wipes off the dust accumulated on the rolling surface, especially the rolling surface of the lower plate. Sand and the like are prevented from adhering or accumulating, and seismic isolation performance is maintained.

[0009] Even if the seismic isolation device is lifted due to the tension acting on the seismic isolation device in the event of an earthquake, the damping function is provided to the retaining ring to actuate braking, and the retaining ring is moved from between the rolling surfaces. There is no risk that the rolling elements will jump out and dissipate.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view of a seismic isolation device according to the present invention,
FIG. 2 is an end view taken along the line II-II of FIG. 1, and FIG. 3 is an enlarged view of a main part of FIG.

As shown in FIG. 1, a lower anchor plate 3 is horizontally laminated and fixed on a top surface of a foundation 1 provided on the ground via a mortar 2 as a fixing member. An upper anchor plate 6 facing the lower anchor plate 3 and a rubber sheet 7 serving as a tilt absorbing member are horizontally laminated and fixed to the lower surface of the base plate. The anchor plates 3 and 6 are thick steel plates. Then, the lower anchor plate 3 and the upper anchor plate 6
And the seismic isolation device 10 is interposed.

The seismic isolation device 10 includes a lower plate 11 and an upper plate 12.
And a plurality of steel balls 13 as rolling elements rotatably interposed between the lower plate 11 and the upper plate 12, and surrounding these steel balls 13 so as to be able to roll freely and not to be dissipated. The holding ring 14 has a built-in damping means for attenuating the movement of the steel ball 13 to quickly stop the shaking. The lower plate 11 and the upper plate 12 are steel plates for rolling the steel balls 13, and the rolling surfaces 11a and 12a are smooth surfaces. Since the lower plate 11 and the upper plate 12 have a large stress when the steel balls 13 roll, hard wear-resistant steel plates that have been subjected to heat treatment or carburizing treatment are used. In addition, lower plate 11, upper plate 1
The surface of each of the rolling surfaces 11a and 12a is subjected to surface treatment such as rust prevention and lubrication, so that a good rolling surface is secured over a long period of time. Accordingly, there is no need to apply oil or the like, so that maintenance is not required, and it is also prevented that dust or the like adheres and solidifies. As the rust-preventive / lubricating surface treatment, for example, a manganese phosphate-based chemical conversion treatment film is formed as a base treatment, and a disulfide molybdenum-based organic bonding solid lubricating film is formed as a rust-preventive / lubricating film on this film. is there. As the lower plate 11 and the upper plate 12, a high hardness stainless steel plate having excellent rust resistance may be used.
In this case, the above-described surface treatment is not particularly necessary.

The steel ball 13 is a load ball for supporting the load of the building 5, and is a small ball (for example, having an outer diameter of about 5 to 15 mm) formed of bearing steel, chrome steel, or the like. Surface treatment such as rust prevention and lubrication as described above has been performed. The steel ball 13 does not necessarily need to be subjected to surface treatment such as rust prevention and lubrication, but is preferably subjected to surface treatment such as rust prevention and lubrication in order to ensure good rolling properties over a long period of time.

As shown in FIG. 2 and FIG.
Has a holding function of surrounding the steel ball 13 so as to be able to roll freely and not to be scattered, and a damping function of applying a damping force between the lower plate 11 and the upper plate 12. Retaining ring 14
The upper ring 15 and the lower ring 1
6 and damping means 20 interposed between the rings 15 and 16.
The upper and lower rings 15 and 16 have substantially the same shape, and are flat rings whose upper and lower surfaces are flat. The rings 15 and 16 are formed of, for example, a metal member such as a steel material, and are in contact with the upper surface 15 a of the upper ring 15 that contacts the rolling surface 12 a of the upper plate 12 and the rolling surface 13 a of the lower plate 13. A sliding material 18 is provided on the lower surface 16a of the lower ring 16 in contact therewith.
Is provided. Examples of the sliding material 18 include a film of ethylene tetrafluoride and a film of ultra-high molecular weight polyethylene. The sliding member 18 is slidable on the upper surface 15a of the upper ring 15 and the lower surface 16a of the lower ring 16 with respect to the rolling surfaces 12a and 11a, and generates a frictional force as an appropriate damping force. is there.

The rings 15, 16 of the holding ring 14
However, the present invention is not limited to a metal member such as a steel member, and another member such as a synthetic resin member may be used. in this case,
The sliding member 18 may not be provided depending on a member to be used. The damping means 20 includes an annular disc spring 21 as an elastic member.
The outer diameter of the upper end is slightly larger than the inner diameter of the upper ring 15, and the outer diameter of the lower end is
The outer peripheral portion 21a of the upper end is engaged with an annular notch 15c formed on the lower surface of the upper ring 15, and the inner peripheral edge 21 of the lower end
b is an annular notch 16c formed on the upper surface of the lower ring 16.
And is irreversibly engaged. Disc spring 21
Presses the sliding member 18 on the upper surface 15a of the upper ring 15 against the rolling surface 12a of the upper plate 12 and the sliding member 18 on the lower surface 16a of the lower ring 16 against the rolling surface 11a of the lower plate 11 by the spring force. As a result, a frictional force (damping force) is generated.

That is, assuming that the friction coefficient between the sliding member 18 of the upper ring 15 and the rolling surface 12a is μ and the spring force (repulsive force) of the disc spring 20 is N, the sliding member 18 and the rolling surface 12a The frictional force F generated therebetween is F = μ · N. Similarly, the frictional force F is applied between the sliding member 18 of the lower ring 16 and the rolling surface 11a.
(= Μ · N) occurs. Therefore, the retaining ring 14
The rolling surfaces 11a, 12 are formed by the upper and lower rings 15 and 16.
A friction force of 2F (= 2 μ · N) can be generated for a. This frictional force is applied to the rolling surface 1 of the retaining ring 14.
The damping force is applied to 1a and 12a, that is, the damping force of the seismic isolation device 10.

The holding ring 14 has a dust-proof function by being sealed by an upper and lower rings 15 and 16 and a disc spring 21 interposed between the rings to hermetically seal the inside. This prevents dust, sand, and the like from entering the inside and accumulating on the sliding surfaces 11 a and 12 a and adhering to the surface of the steel ball 13. By the way, in order for the plurality of steel balls 13 to be rollably accommodated in the holding ring 14 in any direction of 360 ° in the horizontal plane, the steel balls 1
An appropriate gap is required between the three. That is, in a state where the steel balls 13 are fully packed in the holding ring 14 and the adjacent steel balls 13 are in contact with each other, a large frictional force is generated between the steel balls 13 and the steel balls 13 roll with each other. I can not lock it. If the number of steel balls 13 is small, it is difficult to support a sufficient load and to support a stable load. Therefore, it is necessary to accommodate the steel ball 13 in the retaining ring 14 at an appropriate filling rate.

FIG. 4 is an explanatory diagram showing the relationship between the filling rate of the steel balls 13 accommodated in the holding ring 14 and the coefficient of friction generated between adjacent steel balls. As shown in FIG. 4, the coefficient of friction between adjacent steel balls 13 is small when the filling rate is 96% or less, and rapidly increases when the filling rate exceeds 96%.
Therefore, it is preferable to set the filling rate of the steel balls 13 to about 96%.

In order to adjust the filling rate of the steel balls (load balls) 13 for supporting the load as rolling elements, the diameter is slightly smaller than the steel balls 13 (about 90% of the steel balls 13). May be mixed.
By setting the mixing ratio of the spacer balls to about 5 to 25%, the filling rate of the entire steel balls 13 can be set to 70% to 98%. In addition, since the spacer ball does not support a load, it can be formed of a synthetic resin member such as plastic, and does not require surface treatment such as rust prevention and lubrication, which is preferable in terms of cost reduction. Then, the entire steel balls 13 are mixed by mixing the spacer balls.
Of the steel ball 1 even if the filling rate of the steel ball is set in the range of 70% to 98%.
3 enables smooth rolling, and also allows a sufficient load to be stably supported. Of course, the spacer ball may be used according to the specifications of the seismic isolation device.

The operation will be described below. When the foundation 1 moves horizontally in the direction of arrow A due to the earthquake in FIGS. 1 to 3, each steel ball 13 in the holding ring 14 of the seismic isolation device 10
Rolling between the rolling surface 11a of the lower plate 11 and the rolling surface 12a of the upper plate 12 in the direction of arrow B in FIG. 3 keeps the upper plate 12 substantially stationary. Among the plurality of steel balls 13 stored in the retaining ring 14, some of them are in contact with each other.
In 3, the surfaces that come into contact with each other are slid by being subjected to the smooth surface treatment to prevent locking, and the locking phenomenon of the seismic isolation device 10 is avoided. Furthermore, the rolling surfaces 11a, 12a
Has been subjected to rust prevention and lubrication treatment, so that the rolling friction coefficient of the steel ball 13 has a small fluctuation, and seismic isolation performance is stably maintained.

When the spacer balls are mixed as described above, the spacer balls are used as the rolling surfaces 11a, 12b.
Since the steel ball 13 is rotatable without abutting on a, the lock of the steel ball 13 can be favorably suppressed. Therefore, it is preferable to use the spacer ball also in order to effectively prevent the locking phenomenon of the seismic isolation device 10. The retaining ring 14
The upper and lower rings 15 and 16 slide on the rolling surfaces 11 a and 12 a via the sliding members 18 and 18, and a frictional force (damping force) is generated by the disc spring 21. Thereby, the seismic isolation device 1
Unnecessary displacement caused by inertia of zero is prevented and the building 5
Can be stopped immediately. Further, the retaining ring 14 wipes off dust and the like accumulated on the rolling surfaces 11a and 12a when sliding on the rolling surfaces 11a and 12a, and has a dustproof function. Rolling surface 11 inside
By preventing dust and sand from adhering to and accumulating on the steel balls 13 and the steel balls 13, seismic isolation performance is maintained in combination with rust prevention and lubrication treatment of the rolling surfaces 11a and 12a.

Further, even if the seismic isolation device 10 is lifted due to the tension applied to the seismic isolation device 10 during an earthquake, the damping function is provided to the retaining ring 14 so that the braking works and the rolling surfaces 11a, 1
There is no danger that the retaining ring 14 will jump out from between 2a and the steel ball 13 will dissipate. By attaching a restoring coil spring or the like to the holding ring 14, the protrusion can be completely prevented.

Further, since the seismic isolation device 10 is supported via the small-diameter steel balls 13, the position of the center of gravity is extremely low,
The construct 5 can be stably supported. (Embodiment 2) FIG. 5 shows a second embodiment of the damping means 20. The same members as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, the damping means 20
An annular groove 15 d formed on the lower surface of the upper ring 15 and an annular groove formed on the upper surface of the lower ring 16. 16d. Elastic body 22
Is the upper surface 1 of the upper and lower rings 15, 16 due to its elasticity.
5. The sliding members 18, 18 provided on the lower surface 16a are brought into pressure contact with the rolling surfaces 12a, 11a to generate a frictional force on these contact surfaces, thereby imparting a damping force to the seismic isolation device 10. Other configurations, operations, and effects are the same as those in the first embodiment.

(Embodiment 3) FIG. 6 shows a third embodiment of the damping means 20.
An example will be described. The same members as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In the drawing, the damping means 20 is formed of a thin cylindrical elastic body 23 formed of a rubber member and a rigid member having rust resistance and corrosion resistance, for example, a copper member, and is fitted in the elastic body 23. And a cylindrical holder 24 for preventing deformation in the radial direction. The upper portion of the holder 24 is fitted in an annular groove 15f formed on the lower surface of the upper ring 15, and the lower portion is fitted in an annular groove 16f formed on the upper surface of the lower ring 16, and the upper end surface of the elastic body 23 is connected to the upper ring. The lower end surface of the lower ring 15 is pressed against the upper surface of the lower ring 16. The elastic body 23 presses the sliding members 18 provided on the upper surface 15a and the lower surface 16a of the upper and lower rings 15 and 16 against the rolling surfaces 12a and 11a due to the elasticity thereof, and A friction force is generated, and a damping force is applied to the seismic isolation device 10. The deformation of the elastic body 23 in the radial direction is prevented by the holder 24. Other configurations, operations, and effects are the same as those in the first embodiment. The holder 24 is not limited to a metal member, but may be a synthetic resin member.

(Embodiment 4) FIG. 7 shows a fourth embodiment of the damping means 20.
An example will be described. The same members as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, the damping means 20 includes a coil spring 25 and a cylindrical holder 26 formed of a copper member. Holder 2
6 has an annular groove 15 formed on the lower surface of the upper ring 15
f, an annular groove 1 having a lower portion formed on the upper surface of the lower ring 16.
6f. The coil springs 25 are arranged around the holder 26 at predetermined intervals along the circumferential direction and in contact with the outer peripheral surface of the holder 26. The upper end surface is on the lower surface of the upper ring 15, and the lower end surface is on the lower ring 16. Are in pressure contact with the upper surface of each. Then, the upper surface 15 and the lower surface 16 of the upper and lower rings 15 and 16 are
a is provided on the rolling surfaces 12a, 11
a to generate a frictional force on these abutting surfaces to impart a damping force to the seismic isolation device 10. The bending deformation of each coil spring 25 is prevented by the holder 26. Other configurations, operations, and effects are the same as those in the first embodiment. (Embodiment 5) FIG. 8 shows a fifth embodiment of the damping means 20. The same members as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, the damping means 20
It comprises a coil spring 25 and a holder 27 that supports the coil spring 25 so that it can expand and contract. Holder 27
Consists of a pair of upper and lower holders 27a and 27b, the upper part of the holder 27a having a hole 15 formed in the lower surface of the upper ring 15.
h, the lower part of the holder 27b is fitted into a hole 16h formed on the upper surface of the lower ring 16, respectively, and the coil spring 25 is contracted between these holders 27a and 27b. The damping means 20 having such a configuration includes the upper and lower rings 1.
A plurality is provided between 5 and 16 at predetermined intervals along the circumferential direction. The coil spring 25 presses the sliding members 18 provided on the upper surface 15 and the lower surface 16a of the upper and lower rings 15 and 16 against the rolling surfaces 12a and 11a by their spring force, and makes contact with these contact surfaces. A friction force is generated, and a damping force is applied to the seismic isolation device 10. Other configurations, operations, and effects are the same as those in the first embodiment.

(Embodiment 6) FIG. 9 shows a sixth embodiment of the damping means 20.
An example will be described. The same members as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, the damping means 20 is a spring-like annular pipe 2 as an elastic member.
For example, a slit 28a is provided along the circumferential direction substantially at the center of the outer surface of the outer ring 8 so as to be able to expand and contract in the radial direction of the pipe. The lower part is engaged with the groove 15i and the annular groove 16i formed on the upper surface of the lower ring 16, respectively. Annular pipe 2
8 presses the sliding members 18 provided on the upper surface 15 and the lower surface 16a of the upper and lower rings 15 and 16 against the rolling surfaces 12a and 11a by their spring force to apply frictional force to these contact surfaces. The damping force is applied to the seismic isolation device 10. Other configurations, operations, and effects are the same as those in the first embodiment.

As shown in the first to sixth embodiments, the holding ring 14 is constituted by upper and lower rings 15 and 16, and an elastic member is interposed between these rings to reduce the damping means 2.
0 has been described, but the holding ring 14
Is formed in a cylindrical shape that cannot be deformed in the radial direction by an elastic member having appropriate hardness and frictional force, and upper and lower end faces are formed on the upper plate 1.
The lower surface 12a of the second plate 11 and the upper surface 11a of the lower plate 11 may be integrally and elastically and slidably brought into contact with each other to generate a frictional force on each contact surface. By providing the retaining ring with the damping function in this way, the structure is simplified, and it is possible to achieve a significant cost reduction.

(Embodiment 7) FIG. 10 shows a second embodiment of the seismic isolation device according to the present invention. The seismic isolation device 10 shown in FIG.
The same reference numerals are given to the same members as the above-mentioned constituent members, and the description is omitted. In the figure, a seismic isolation device 30 is a multi-stage, for example, two-tiered, two-stage rolling bearing structure of the seismic isolation device 10 shown in FIG. And a two-stage seismic isolation device 10 ′ installed on the seismic isolation device 10 and supporting the building 5.
The middle plate 31 as a rolling plate interposed between 0 and 10 'is a common rolling plate for these seismic isolation devices 10, 10', and the lower surface 31a is a steel ball of the seismic isolation device 10. 13
And the upper surface 31b is a lower rolling surface of the steel ball 13 of the seismic isolation device 10 '. In this case, by reducing the outer diameter of the steel ball 13 of each of the seismic isolation devices 10, 10 ′,
It is possible to lower the position of the center of gravity of the seismic isolation device 30.

In such a configuration, as shown in FIG. 11, a middle plate 31 interposed between the seismic isolation devices 10 and 10 '.
Is a half of the horizontal movement amount δ of the lower plate 11 installed on the foundation 1, and the rolling movement amount of each steel ball 13 of each seismic isolation device 10, 10 ′ is , Lower plate 11
Is １ ／ of the horizontal movement amount δ. Therefore, according to the two-stage rolling bearing structure, the required rolling surface area of the lower plate 11, the middle plate 31, and the upper plate 12 is reduced to 1/4 as compared with the one-stage rolling bearing structure shown in FIG. Becomes possible.

Embodiment 8 FIGS. 12 and 13 show a third embodiment of the seismic isolation device according to the present invention. The same members as those of the seismic isolation device 10 shown in FIG. In the figure, a seismic isolation device 40 is arranged such that a plurality of steel balls 13 are arranged in a circumferential direction on a ring-shaped retainer 41 so as to be rollably supported, and a plurality of the steel balls 13 are rollably accommodated inside the retainer 41. The holding ring 14 having any one of the damping means 20 shown in the first to sixth embodiments is mounted on the outside of the retainer 41. According to this configuration, the steel ball 13 supported by the retainer 41 can smoothly roll in a stable state in a wide area, and the seismic isolation device 40 operates more stably.

The seismic isolation device of the present invention is not limited to the case where a large structure such as a building or a bridge is supported. For example, a floor seismic isolation device for a structure, a rack seismic isolation device, It can also be used as a seismic isolation device for machinery, precision equipment, and electronic computers. In particular, since the center of gravity of the seismic isolation device can be lowered, it can also be used as a seismic isolation display stand for art objects such as Buddha statues placed on the mounting table, or as a seismic isolation device to prevent the fall of chemical tanks, medicine shelves, etc. It is suitable.

[0032]

As described above, according to the first aspect of the present invention, the holding ring surrounding the rolling element so as to freely roll is provided with an attenuating function, so that the height is reduced and the size is reduced. In addition to space saving and cost reduction of the device,
A dustproof function can be added at the same time, so that the adhesion and accumulation of dust inside can be prevented, so that the rolling elements can operate smoothly and the performance of the seismic isolation device can be maintained stably. can do.

According to the second to fourth aspects of the present invention, the damping force is applied by generating a frictional force between the holding ring, the upper plate, and the lower plate as the damping means. Function can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a seismic isolation device according to the present invention.

FIG. 2 is an end view of the seismic isolation device shown in FIG. 1 along the line II-II.

FIG. 3 is an enlarged detailed view of a main part of the seismic isolation device shown in FIG.

FIG. 4 is an explanatory diagram showing a relationship between a filling ratio of steel balls in a retaining ring shown in FIG. 2 and a friction coefficient.

FIG. 5 is a sectional view of a main part of a second embodiment of the damping means in the seismic isolation device according to the present invention.

FIG. 6 is a sectional view of a main part of a third embodiment of the damping means in the seismic isolation device according to the present invention.

FIG. 7 is a sectional view of a main part of a fourth embodiment of the damping means in the seismic isolation device according to the present invention.

FIG. 8 is a sectional view of a main part of Embodiment 5 of the damping means in the seismic isolation device according to the present invention.

FIG. 9 is a sectional view of a main part of Embodiment 6 of the damping means in the seismic isolation device according to the present invention.

FIG. 10 is a sectional view of Embodiment 2 of the seismic isolation device according to the present invention.

11 is an operation explanatory view of the seismic isolation device shown in FIG.

FIG. 12 is a sectional view of Embodiment 3 of the seismic isolation device according to the present invention.

13 is an end view of the seismic isolation device shown in FIG. 12, taken along the line XIII-XIII.

[Explanation of symbols]

 Reference Signs List 1 foundation 2 mortar 3, 6 anchor plate 7 rubber sheet 5 building (upper structure) 10, 10 ', 30, 40 seismic isolation device 11 lower plate 12 upper plate 13 steel ball (rolling element) 14 retaining ring 15 upper ring Reference Signs List 16 lower ring 20 damping means 21 disc spring 22, 23 elastic body 24, 26, 27 holder 25 coil spring 28 annular pipe (elastic body) 31 middle plate 41 retainer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kaoru Tamachi 6-1 Hanamidai, Arashiyama-cho, Hiki-gun, Saitama F-term in the Arashiyama Plant of Daido Precision Industry Co., Ltd. (Reference) 2D059 GG05 3J048 AA03 AC01 BA08 BC01 BC02 BC05 BE14 DA01 EA38 EA39

Claims (4)

[Claims] A lower plate installed horizontally on a foundation; an upper plate fixed horizontally on a lower surface of a structure so as to face the lower plate; and rolling between the lower plate and the upper plate. A plurality of rolling elements that are freely interposed to support the structure; and a damping element that is interposed between the lower plate and the upper plate to rotatably surround the rolling elements and attenuate movement by the rolling elements. And a retaining ring having means. 2. The seismic isolation device according to claim 1, wherein the damping means generates a frictional force between the holding ring, the lower plate, and the upper plate. 3. The holding ring is slidable with its lower surface in contact with the upper surface of the lower plate and its upper surface in contact with the lower surface of the upper plate, and generates a frictional force on each contact surface. The seismic isolation device according to claim 1 or 2, characterized in that: 4. The holding ring is interposed between an upper ring, a lower ring, and the upper and lower rings, an upper surface of the upper ring being a lower surface of the upper plate, and a lower surface of the lower ring being an upper surface of the lower plate. The seismic isolation device according to any one of claims 1 to 3, further comprising an elastic member pressed against the base member.