JP2001200890A - Base isolation bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promptly damp vibration with a simple structure eliminating the need of a space, with reference to a rolling base isolation bed provided with a spherical body 10. SOLUTION: An elastomer member 12 is provided on a surface part of both concave portions 3a, 7a of an upper and a lower members 1, 5. When an earthquake occurs, a spherical body 10 is structured to roll over between both concave portions 3a, 7a with contacting the concave portions 3a, 7a surfaces of the upper and lower member 1, 5 through the elastomer member 12. Damping force is applied on the spherical body 10 by the elastomer member 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation table on which objects that need to be prevented from falling down due to an earthquake, such as display cases for arts and crafts, medical equipment, OA equipment, etc., are placed. Belongs to.

[0002]

2. Description of the Related Art Conventionally, a rolling-type seismic isolation table of this type has been known, and this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-262759. An upper member having a concave portion formed thereon, and a lower member having a dish-shaped concave portion formed on an upper surface thereof so as to face a lower side of the concave portion of the upper member. Both concave portions of the upper and lower members are provided. A sphere is provided between the spheres so as to be rollable, and the sphere supports the upper member with respect to the lower member. In this seismic isolation table, when an earthquake occurs, the sphere rolls between the concave portions of the upper and lower members in the direction of the seismic motion, so that the upper member relatively moves with respect to the lower member. Thus, the object placed on the upper surface of the upper member can be prevented from falling down.

[0003]

However, in the above-mentioned conventional rolling type, since the mechanism for damping the vibration with respect to the lower member of the upper member is based on gravity, the upper member is in contact with the lower member. Shows behavior close to free vibration,
Vibration is difficult to settle, and it is necessary to separately provide a damping mechanism having a hydraulic damper and a high-viscosity damping agent in order to damp the vibration, which makes the seismic isolation table complicated and expensive. There's a problem.

[0004] The present invention has been made in view of such a point, and an object of the present invention is to improve the structure of the above-mentioned rolling seismic isolation table by improving the structure.
An object of the present invention is to provide a simple and space-saving configuration for quickly damping vibration.

[0005]

In order to achieve the above-mentioned object, according to the present invention, when an earthquake occurs, a sphere contacts the surfaces of both upper and lower members via an elastomer member to form a gap between the two concave portions. I tried to roll.

More specifically, according to the first aspect of the present invention, the upper member having the dish-shaped recess formed on the lower surface, and the dish-shaped recess formed on the upper surface so as to face below the recess of the upper member. The present invention is directed to a seismic isolation table including a formed lower member and a sphere that is provided between the recesses of the upper and lower members so as to be rollable and supports the upper member with respect to the lower member.

Further, it is assumed that the sphere rolls between the concave portions of the upper and lower members while coming into contact with the surfaces of the concave portions of the upper and lower members via an elastomer member when an earthquake occurs.

[0008] With the above configuration, when the sphere rolls between the two concave portions when an earthquake occurs, a seismic isolation effect is obtained, and when the sphere rolls, a damping force is applied to the sphere by the elastomer member, so that the vibration is rapidly attenuated. Such an elastomer member may be provided in both the concave portions and the surface of the sphere, and has a simple configuration and does not require a large space. As a result, it is not necessary to separately provide a damping mechanism such as a hydraulic damper, and a low-cost and small seismic isolation table can be obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, the elastomer member is provided on the surface of both the concave portions of the upper and lower members. Claim 3
According to the invention, the elastomer member is provided on the entire surface of the sphere.

According to these inventions, the elastomer member can be easily provided in a small space, and the magnitude of the damping force can be adjusted by changing the material, thickness, surface roughness, hardness, etc. of the elastomer member. Can be.

According to a fourth aspect of the present invention, in the third aspect, a viscous body is provided inside the elastomer member.

Thus, when the sphere rolls and the elastomer member is deformed, a larger damping force is exerted on the sphere by the viscous body, so that the vibration can be more effectively damped.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, there is provided a regulating means for regulating a maximum horizontal displacement of the upper member relative to the lower member to a predetermined value or less. .

Thus, it is possible to prevent the sphere from jumping out of the concave portion when an earthquake with a seismic intensity larger than expected occurs.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the restricting means is a string-shaped member made of a polymer material and connecting the upper and lower members.

By doing so, the regulating means can be simply configured, and by setting the length of the cord-like member to an appropriate value, it is possible to prevent the sphere from jumping out of the concave portion. In addition, if the string-shaped member is made of a material that can be stretched to some extent by the action of tension, when the relative movement of the upper member with respect to the lower member is restricted by the string-shaped member, the string-shaped member is stretched and a large impact force is applied to the upper member. Can be suppressed. Therefore, even when an earthquake with a seismic intensity larger than expected occurs, it is possible to prevent the object placed on the upper member from falling down.

According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the restricting means is a stopper member provided on the entire periphery of both the concave portions of the upper and lower members and restricting the rolling movement of the sphere. Shall be.

By this, it is possible to prevent the sphere from jumping out of the concave portion due to contact with the stopper member, and to provide an elastomer member on the sphere contact surface portion of the stopper member. The impact force acting on the upper member at the time of contact with the sphere can be reduced. Therefore, the same function and effect as the sixth aspect of the invention can be obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIGS.
1 shows a seismic isolation table according to Embodiment 1 of the present invention, which includes an upper member 1 and a lower member 5 which are vertically opposed to each other.
A display case for arts and crafts, a medical device, an OA device, etc. are placed on the upper surface of the upper member 1 so that the placed product does not fall down when an earthquake occurs. It is.

The upper member 1 comprises an upper member body 2 having a substantially rectangular shape in a plan view and upper support members 3 fixed to four corners on the lower surface of the upper member body 2, respectively. A dish-shaped concave portion 3a is formed on the lower surface of the member 3.

On the other hand, the lower member 5 includes a lower member main body 6 having a substantially rectangular shape in a plan view and lower support members 7 attached and fixed to four corners on the upper surface of the lower member main body 6, respectively. A dish-shaped recess 7a is formed on the upper surface of the lower support member 7 so as to face below the recess 3a of the upper support member 3. The upper and lower support members 3 and 7 are made of a metal member such as steel or a reinforced resin member such as carbon fiber reinforced plastic.

The surfaces of the recesses 3a, 7a of the upper and lower support members 3, 7 are both spherical,
A metal sphere 10 for supporting the upper support member 3 (upper member 1) with respect to the lower support member 7 (lower member 5) is provided between a and 7a. The uppermost support member 3 is in contact with the most concave portion (uppermost portion) of the concave portion 3a and the lower support member 7 is in contact with the most concave portion (lowest portion) of the concave portion 7a.

The radius of curvature R of the surface of the concave portions 3a, 7a of the upper and lower support members 3, 7 and the radius r of the sphere 10 are as follows:
The sphere 10 is provided with both concave portions 3a of the upper and lower support members 3, 7,
Assuming that T is the natural period when rolling on the surface of 7a and g is the gravitational acceleration, it is determined by T = 2 × π × ((R−r) / g) ^1/2 .

On the surfaces of the recesses 3a, 7a of the upper and lower support members 3, 7, high damping rubber, urethane rubber,
A thin plate-like elastomer member 12 made of a polymer material or the like is adhered and fixed, so that the seismic isolation table allows the sphere 10 to move to the upper and lower support members 3, 7 when the earthquake occurs.
It is configured to roll between the two concave portions 3a and 7a while contacting the surfaces of the concave portions 3a and 7a with the elastomer member 12 interposed therebetween.

The central portions of the lower surface of the upper member main body 2 and the upper surface of the lower member main body 6 are connected to each other by a string-shaped member 15 made of a polymer material such as nylon or vinyl. The string-shaped member 15 constitutes a restricting means for restricting the maximum horizontal displacement of the upper member 1 relative to the lower member 5 to a predetermined value or less. The length is set so that the sphere 10 does not protrude outside the concave portions 3a, 7a of the upper and lower support members 3, 7 when the maximum displacement occurs.

The operation of the seismic isolation table having the above-described configuration when an earthquake occurs will be described.

When an earthquake occurs, the lower member 5 shakes in response to the seismic motion. At this time, as shown in FIG.
Reciprocates (vibrates) while rolling between the concave portions 3a and 7a of the upper and lower support members 3 and 7 in the direction of the seismic motion. Since the upper member 1 moves relative to the lower member 5 in the direction of the seismic motion with the movement of the sphere 10, the swing of the lower member 5 is not transmitted to the upper member 1 and the upper member 1
Can be suppressed. As a result, the object placed on the upper surface of the upper member 1 can be prevented from falling down. Moreover, when the sphere 10 rolls between the recesses 3a, 7a of the upper and lower support members 3, 7, a damping force acts on the sphere 10 by the elastomer member 12 provided on the surface of the recesses 3a, 7a. Therefore, the vibration can be rapidly attenuated. The magnitude of the damping force can be adjusted by changing the material, thickness, surface roughness, hardness and the like of the elastomer member 12. Therefore, it is not necessary to separately provide a damping mechanism such as a hydraulic damper for rapidly damping the vibration, and the configuration is simplified, and the seismic isolation table can be reduced in cost and size.

Further, since the central portions of the lower surface of the upper member main body 2 and the upper surface of the lower member main body 6 are connected to each other by the string-shaped member 15, even if an earthquake with a seismic intensity larger than expected occurs, Before jumping out of the recesses 3a, 7a, the string member 15 restricts the relative movement of the upper member 1 with respect to the lower member 5. Moreover, since the string-like member 15 is made of a polymer material, the string-like member 15 is stretched to some extent when tension is applied to the string-like member 15, so that the relative movement of the upper member 1 with respect to the lower member 5 is restricted by the string-like member 15. To
The string-like member 15 extends, so that a large impact force does not act on the upper member 1. Therefore, even when an earthquake with a seismic intensity larger than expected occurs, it is possible to prevent the object placed on the upper surface of the upper member 1 from falling over.

In the first embodiment, the central portions of the lower surface of the upper member main body 2 and the upper surface of the lower member main body 6 are connected to each other by one string-shaped member 15, for example, as shown in FIG. , Upper member main body 2 by four cord members 15
May be connected to the four side surfaces of the lower member body 6, respectively. (Embodiment 2) FIG. 5 shows Embodiment 2 of the present invention.
In the following embodiments, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.)
The restriction means for restricting the maximum horizontal displacement of the lower member 5 to a predetermined value or less is different from that of the first embodiment.

That is, in the second embodiment, instead of the string-like member 15 in the first embodiment, a spherical member is provided on the entire periphery of the concave portions 3a, 7a of the upper and lower support members 3, 7 as a regulating means. Stopper members 17 for restricting the rolling movement of 10 are provided respectively. The stopper member 17 of the upper support member 3 is provided integrally with the upper support member 3 so as to protrude downward, and the stopper member 17 of the lower support member 7 is provided so as to protrude upward. 7
The sphere 10 is brought into contact when an earthquake with a magnitude higher than expected occurs. An elastomer member 12 provided on the surface of both recesses 3a, 7a extends from the contact surface of the sphere 10 of both stopper members 17, and the sphere 10 is attached to the stopper member 17a.
Are brought into contact with each other via an elastomer member 12 (see FIG. 6). The spheres 10 of both stopper members 17
Has a spherical surface, and its radius of curvature r 'is
The radius is set to be larger than the radius r of 0 and smaller than the radius of curvature R of the surfaces of the concave portions 3a and 7a.

Therefore, also in the second embodiment,
As in the first embodiment, the vibration can be rapidly attenuated by the elastomer member 12, and even if an earthquake with a seismic intensity larger than expected occurs, the sphere 10 is moved by the stopper member 17 to the upper and lower support members 3. , 7 can be prevented from jumping out of the recesses 3a, 7a. In addition, the elastomer member 12 is the stopper member 1
7 extends to the contact surface portion of the sphere 10, the impact force acting on the upper member 1 can be reduced even when the sphere 10 contacts the stopper member 17, and the sphere 10 is placed on the upper surface of the upper member 1. The placed object can be prevented from falling down.

(Embodiment 3) FIG. 7 shows Embodiment 3 of the present invention.
And the arrangement position of the elastomer member 12 is different from those of the first and second embodiments.

That is, in the second embodiment, the elastomer member 12 is provided on the entire surface of the spherical body 10 and is not provided on the surface of the concave portions 3a, 7a of the upper and lower support members 3, 7. The center of the sphere 10 is made of a hard material such as metal.

Therefore, also in the third embodiment,
As in the first and second embodiments, when the sphere 10 rolls between the concave portions 3a, 7a of the upper and lower support members 3, 7, the sphere 10 is formed by the elastomer member 12 provided on the entire surface of the sphere 10. Since the damping force acts on the vibration, the vibration can be rapidly damped. Further, the magnitude of the damping force can be adjusted by changing the material, thickness, surface roughness, hardness and the like of the elastomer member 12. Therefore, the same operation and effect as those of the first and second embodiments can be obtained.

In the third embodiment, the central portion of the sphere 10 is formed of a hard member such as a metal, but the central portion may be formed of an elastomer member 12 (the same material as the surface portion or a different material). Good. Further, a viscous body such as silicon may be provided inside the elastomer member 12. in this case,
The viscous body may be provided between the elastomer member 12 and the hard member at the center, or the viscous body may be provided over the entire center without the hard member. By providing the viscous body in this manner, when the sphere 10 rolls and the elastomer member 12 is deformed, a larger damping force acts on the sphere 10 by the viscous body, and the vibration can be more effectively damped.

In the third embodiment, as in the first embodiment, the central portions of the lower surface of the upper member main body 2 and the upper surface of the lower member main body 6 are connected to each other by the string-shaped member 5. As described above, stopper members 17 for restricting the rolling movement of the sphere 10 may be provided on the entire periphery of the concave portions 3a, 7a of the upper and lower support members 3, 7, respectively.

[0037]

As described above, according to the seismic isolation table of the present invention, when an earthquake occurs, the sphere rolls between the concave portions of the upper and lower members while making contact with the surfaces of the concave portions via the elastomer member. With this configuration, it is possible to obtain a low-cost and small seismic isolation table capable of rapidly attenuating vibration.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view taken along line II of FIG.

FIG. 2 is a perspective view showing the seismic isolation table according to Embodiment 1 of the present invention.

FIG. 3 is a diagram corresponding to FIG. 1, showing a state when the seismic isolation table is operated.

FIG. 4 is a diagram corresponding to FIG. 2, showing a modification of the first embodiment.

FIG. 5 is a view corresponding to FIG. 1 showing a second embodiment.

FIG. 6 is a view showing an operation state of the base isolation table according to the second embodiment.
FIG.

FIG. 7 is a view corresponding to FIG. 1 showing a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper member 3a recessed part 5 Lower member 7a recessed part 10 Spherical body 12 Elastomer member 15 String-shaped member (restriction means) 17 Stopper member (restriction means)

Claims (7)

[Claims] An upper member having a dish-shaped recess formed on a lower surface; a lower member having a dish-shaped recess formed on an upper surface to face a lower side of the recess of the upper member; And a sphere that is provided between the two concave portions of the lower member so as to be rollable, and that supports the upper member with respect to the lower member. A seismic isolation table configured to roll between the concave portions while contacting the surfaces of the concave portions of the member via an elastomer member. 2. The seismic isolation table according to claim 1, wherein the elastomer member is provided on the surface of both recesses of the upper and lower members. 3. The seismic isolation table according to claim 1, wherein the elastomer member is provided on the entire surface of the sphere. 4. The seismic isolation table according to claim 3, wherein a viscous body is provided inside the elastomer member. 5. The seismic isolation table according to claim 1, further comprising a regulating means for regulating a maximum horizontal displacement of the upper member relative to the lower member to a predetermined value or less. Seismic isolation table. 6. The seismic isolation table according to claim 5, wherein the restricting means is a string-shaped member made of a polymer material and connecting the upper and lower members. 7. The seismic isolation table according to claim 5, wherein the restricting means is a stopper member provided on the entire periphery of both concave portions of the upper and lower members and restricting the rolling movement of the sphere. Characteristic seismic isolation table.