JP2017009013A - Seismic isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seismic isolator having a restoration function and capable of realizing pull-out resistance against a lift force caused by earthquake through its simple configuration.SOLUTION: A lower rail 22 rotatably arranged at a lower structure 12 is formed to extend with a prescribed curvature factor such that a central part in its extending direction is positioned at a lower location than those of both ends in its extending direction. An upper rail 26 rotatably arranged at an upper structure 14 is formed to extend with the same curvature factor as that of the lower rail 22 such that a central part in its extending direction is positioned at a higher location than those of both ends in its extending direction. A slider 28 is arranged between the lower rail 22 and the upper rail 26 so as to transmit a load of the upper structure 14 to the lower structure 12, and connects the lower rail 22 and the upper rail 26 in such a way that these rails 22, 26 can be relatively displaced in their extending directions.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a seismic isolation device that is disposed between a lower structure and an upper structure, and that supports the upper structure on the lower structure by seismic isolation, thereby protecting the upper structure from vibrations such as earthquakes. .

  One of the seismic isolation devices is a seismic isolation device using a spherical sliding bearing. That is, a seismic isolation device having a lower spherical bearing provided on the upper surface of the lower structure, an upper spherical bearing provided on the lower surface of the upper structure, and a spherical slider provided between the lower spherical bearing and the upper spherical bearing. (Patent Document 1). According to such a seismic isolation device, in the event of an earthquake, since the upper structure and the lower structure can be relatively displaced in the horizontal direction by the spherical slider, the propagation of the earthquake motion to the upper structure can be reduced. it can.

Moreover, in order to prevent the upward displacement of the structure, for example, a seismic isolation device is known that is configured by superimposing a linear upper guide rail and a lower guide rail so as to be orthogonal to each other (Patent Document 2). .
In this seismic isolation device, the linear upper guide rail and lower guide rail are movable with each other by a large number of balls, and the balls prevent displacement of both rails in the vertical direction. Can demonstrate power.

JP 2015-48929 Japanese Patent Laid-Open No. 10-169709

However, the seismic isolation device using the spherical sliding bearing as disclosed in Patent Document 1 includes a mechanism that resists the lifting force when the seismic force acts upward on the lower structure. As a result, there is a problem that the building may be lifted unexpectedly.
And in the seismic isolation apparatus using the linear motion rail type rolling bearing as disclosed in Patent Document 2, it is necessary to separately provide an elastic member such as a spring on the apparatus in order to exhibit the restoring function. Providing members that exhibit different functions creates a complicated device configuration and difficulty in device design, leading to an increase in device manufacturing costs.
Accordingly, the present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a seismic isolation device having a restoring function and capable of exerting a pulling-out resistance against a lifting force due to an earthquake with a simple configuration. Is to provide.

In order to achieve the object, an invention according to claim 1 is a seismic isolation device provided between a lower structure and an upper structure, and a lower rotating mechanism provided on an upper part of the lower structure, A lower rail that is supported by the lower rotating mechanism so as to be rotatable about a vertical axis, extends at a predetermined curvature, and is located at a position where the central portion in the extending direction is lower than both ends in the extending direction; and the upper portion An upper rotating mechanism provided at the lower part of the structure, and supported by the upper rotating mechanism so as to be rotatable around a vertical axis, and extending with a predetermined curvature, the center part in the extending direction is both end parts in the extending direction. It is arranged between the upper rail located at a higher position, the lower rail and the upper rail, and transmits the load of the upper structure to the lower structure and moves to the lower rail in its extending direction Freely engage and from the lower rail Engaging with the upper rail so as to be movable in the extending direction thereof, and engaging with the upper rail so as not to move in the direction of separating the upper rail upward, Furthermore, it is provided with the slider which extends the said lower rail and the said upper rail on the same straight line when planarly viewed.
The invention according to claim 2 is characterized in that the curvature of the lower rail and the curvature of the upper rail are the same.
According to a third aspect of the present invention, the lower rotating mechanism includes a disk-shaped lower rotating body attached to the lower rail and rotatably supported about a vertical axis, and the lower rail is the lower rotating body. The lower rotating body extends above the diameter of the lower rotating body, the central portion in the extending direction of the lower rail is positioned on the center of the lower rotating body, and the upper rotating mechanism is attached to the upper rail. A disc-shaped upper rotating body supported rotatably about a vertical axis, and the upper rail extends below the upper rotating body on a diameter of the upper rotating body, and the upper rail extends. The center part of the present direction is located on the center of the upper rotating body.
According to a fourth aspect of the present invention, the lower rotating mechanism includes a bearing that rotatably supports the lower rotating body, a lower case that is provided above the lower structure and holds the bearing, and A lower central axis that extends vertically through the center and is inserted through the lower rotating body and the lower case, and a bearing that rotatably supports the lower central axis at least one of the lower rotating body or the lower case. The upper rotating mechanism passes through the center of the upper rotating body, a bearing that rotatably supports the upper rotating body, an upper case that is provided below the upper structure and holds the bearing. An upper central axis extending in a vertical direction and inserted through the upper rotating body and the upper case; and a bearing that rotatably supports the upper central axis at least one of the upper rotating body or the upper case. And wherein the are.
According to a fifth aspect of the present invention, the lower rotating body is rotatably supported by the bearing held by the lower case and is not movable in the vertical direction, and the upper rotating body is supported by the bearing held by the upper case. Is supported so as to be rotatable and immovable in the vertical direction.
The invention according to claim 6 is characterized in that the upper central shaft transmits a part of the load of the upper structure to the upper rail.

According to the first aspect of the present invention, there is obtained a seismic isolation device that is excellent in load supporting ability, has a restoring function without requiring an elastic body, has a simple structure, and can exhibit pull-out resistance against lifting force. It is done.
According to the second aspect of the invention, it is advantageous for smoothing the movement of the slider and smoothing the movement of the seismic isolation device.
According to the third aspect of the invention, it is advantageous to simply configure the lower rotating mechanism and the upper rotating mechanism.
According to the fourth aspect of the invention, it is advantageous to simply configure the lower rotating mechanism and the upper rotating mechanism.
According to the fifth aspect of the present invention, it is advantageous for exerting the pulling resistance against the lifting force.
According to the sixth aspect of the invention, it is advantageous in reducing the size of the seismic isolation device.

It is explanatory drawing which carries out seismic isolation support of the upper structure with the seismic isolation apparatus of embodiment of this invention on a lower structure. It is a section front view of the seismic isolation device of an embodiment of the present invention. It is a section side view of the seismic isolation device of an embodiment of the present invention. It is the top view which looked at the state of FIG. 3 from the slider part. FIG. 4 is a cross-sectional side view of the seismic isolation device in a state where the lower structure and the upper structure are relatively displaced from the state of FIG. 3. FIG. 6 is a plan view of FIG. 5.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the seismic isolation device 10 is provided at a plurality of locations between the lower structure 12 and the upper structure 14, and supports the upper structure 14 on the lower structure 12.
In the present embodiment, the lower structure 12 is a foundation of a building, and the upper structure 14 is a building. The seismic isolation device 10 is also used for supporting an intermediate part in the vertical direction of a building or a bridge, and therefore the lower structure 12 may be a building itself or a bridge foundation in addition to the building foundation. In some cases, the upper structure 14 may be a floor or a bridge of a building. In such a case, the present invention is widely applied.
The seismic isolation device 10 includes a lower rotating mechanism 20, a lower rail 22, an upper rotating mechanism 24, an upper rail 26, and a slider 28.

As shown in FIGS. 2 to 4, the lower rotating mechanism 20 includes a lower rotating body 30, a thrust bearing 32, a lower case 34, a lower central shaft 36, and a radial bearing 38.
The lower case 34 includes a circular lower plate portion 3402 that is fixed on the foundation and extends on a horizontal plane, a standing portion 3404 that rises from the outer periphery of the lower plate portion 3402, and a ring that extends radially inward from the upper end of the standing portion 3404. And a flange portion 3406 that expands in a plate shape.
The lower portion of the lower central shaft 36 is fitted and fixed in the central hole 3408 of the lower plate portion 3402 and is erected vertically.
The thrust bearing 32 is disposed between the outer peripheral portion of the lower plate portion 3402 and the flange portion 3406.

The lower rotating body 30 is formed in a circular plate shape with a diameter larger than the length of the lower rail 22, and is disposed inside the lower case 34.
The outer periphery of the lower rotating body 30 is supported by a thrust bearing 32 so as to be rotatable on a horizontal plane. Further, the upper part of the lower central shaft 36 is inserted into the hole 3002 at the center of the lower rotating body 30 via the radial bearing 38, and the lower rotating body 30 is supported to be rotatable about the lower central shaft 36.

The lower rail 22 is fixed to the upper surface of the lower rotator 30 so that the extending direction thereof is along the diameter of the lower rotator 30.
The upper portion of the lower rail 22 is a rail portion 22A having side surfaces 2202 on both sides and an upper surface 2204.
The upper surface 2204 extends with a predetermined curvature, and is formed so that the central portion in the extending direction is located at a position lower than both end portions in the extending direction, and the extending direction of the upper surface 2204 is formed on the side surfaces 2202 on both sides. A slider groove 2206 is formed along the line. The upper surface 2204 extends linearly when viewed in plan.

The upper rotating mechanism 24 includes an upper rotating body 40, a thrust bearing 42, an upper case 44, an upper central shaft 46, and a radial bearing 48.
The upper case 44 has a circular upper plate portion 4402 that is fixed to the lower portion of the building and extends on the horizontal plane, a standing portion 4404 that protrudes downward from the outer periphery of the upper plate portion 4402, and a radius from the upper end of the standing portion 4404. It has a flange portion 4406 that expands in the shape of an annular plate on the inner side in the direction.
The upper portion of the upper central shaft 46 is fitted and fixed in the central hole 4408 of the upper plate portion 4402 and extends vertically.
The thrust bearing 42 is disposed between the outer peripheral portion of the upper plate portion 4402 and the flange portion 4406.

The upper rotating body 40 is formed in a circular plate shape with a diameter larger than the length of the upper rail 26, and is disposed inside the upper case 44.
The outer periphery of the upper rotating body 40 is supported by a thrust bearing 42 so as to be rotatable on a horizontal plane. Further, the upper part of the lower central shaft 36 is inserted into the hole 4002 at the center of the upper rotating body 40 via the radial bearing 48, and the upper rotating body 40 is supported to be rotatable about the upper central axis 46.

The upper rail 26 is fixed to the lower surface of the upper rotating body 40 so that the extending direction thereof is along the diameter of the upper rotating body 40.
The lower portion of the upper rail 26 is a rail portion 26 </ b> A having side surfaces 2602 and a lower surface 2604 on both sides.
The lower surface 2604 extends with the same curvature as the upper surface 2204 of the lower rail 22 and is formed such that the central portion in the extending direction is positioned higher than both end portions in the extending direction. A slider groove 2606 is formed along the extending direction of the lower surface 2604. The lower surface 2604 extends linearly when viewed from the bottom. Note that the curvature of the upper surface 2204 of the rail portion 22A of the lower rail 22 and the curvature of the lower surface 2604 of the rail portion 26A of the upper rail 26 do not have to be the same. This is advantageous in facilitating the movement of the seismic isolation device 10.

The slider 28 is disposed between the lower rail 22 and the upper rail 26, transmits the load of the upper structure 14 to the lower structure 12, and extends the lower rail 22 and the upper rail 26 to the extension of the rails 22 and 26. It is coupled so as to be relatively displaceable in the present direction. Therefore, the lower rail 22, the upper rail 26, and the slider 28 constitute a rolling bearing.
In the present embodiment, the slider 28 engages with the lower rail 22 and the upper rail 26 so as to be movable in their extending directions, and is not movable in a direction perpendicular to the extending directions of the upper rail 26 and the lower rail 22. The slider 28 extends on the same straight line when the lower rail 22 and the upper rail 26 are viewed in a plan view.

More specifically, the slider 28 includes a main body portion 50 having a vertical height, a slider lower portion 52 provided at the lower portion of the main body portion 50, and a slider upper portion 54 provided at the upper portion of the main body portion 50. Yes.
The slider lower part 52 has a lower surface part 5202 and side parts 5204 on both sides.
The lower surface portion 5202 is engaged with the upper surface 2204 of the rail portion 22A of the lower rail 22 via a bearing 5206 so as to be movable in the extending direction of the upper surface 2204. The load of the upper structure 14 is transmitted from the lower surface portion 5202 to the upper surface 2204 of the rail portion 22A.
The side portions 5204 on both sides are located outside the side surface 2202 of the rail portion 22A, and extend in the direction in which the upper surface 2204 of the rail portion 22A extends to the side surface 2202 of the rail portion 22A via a bearing 5208 that engages the slider groove 2206. It is movably engaged. The side parts 5204 on both sides are engaged with the rail part 22A so as to be movable in the extending direction and are immovably engaged in a direction away from the rail part 22A, and the extending direction of the rail part 22A in the horizontal direction. The movement of the slider 28 in the direction orthogonal to the direction is prevented.

The slider upper part 54 has an upper surface part 5402 and side parts 5404 on both sides.
Upper surface portion 5402 is engaged with lower surface 2604 of rail portion 26 </ b> A of upper rail 26 via bearing 5406 so as to be movable in the extending direction of lower surface 2604. The load of the upper structure 14 is transmitted from the lower surface 2604 of the rail portion 26A to the upper surface portion 5402.
The side portions 5404 on both sides are located outside the side surface 2602 of the rail portion 26A, and extend in the direction in which the lower surface 2604 of the rail portion 26A extends to the side surface 2602 of the rail portion 26A via a bearing 5408 engaged with the slider groove 2606. It is movably engaged. The side portions 5404 on both sides engage with the rail portion 26A so as to be movable in the extending direction, and engage with the upper rail 26A so that the upper rail 26A cannot move in a direction away from the upper rail 26A. The movement of the slider 28 in the direction orthogonal to the extending direction of 26A is prevented.

Next, the movement of the seismic isolation device 10 will be described.
In normal times (when stationary), the load of the upper structure 14 acts on the seismic isolation device 10, and the upper structure 14 is located at the lowest position. That is, the slider 28 is positioned at the center of the rail portion 22A of the lower rail 22 and at the center of the rail portion 26A of the upper rail 26, and the load of the upper structure 14 is transmitted through the plurality of seismic isolation devices 10 to the lower structure. 12 is supported.
In this state, as shown in FIG. 3, the distance from the upper surface of the lower rotating body 30 to the slider lower part 52 is D1, and the distance from the lower surface of the upper rotating body 40 to the slider upper part 54 is D2.

When an excessive horizontal force acts on the building at the time of the earthquake, the lower structure 12 and the upper structure 14 are relatively displaced in the horizontal direction via the seismic isolation device 10.
More specifically, when an excessive horizontal force acts on the building, when the direction of the horizontal force acting on the building is different from the extending direction of the lower rail 22 and the upper rail 26, the lower rail 22 or the upper rail 26 Due to the acting horizontal force, the lower rotating body 30 and the upper rotating body 40 rotate so that the extending directions of the lower rail 22 and the upper rail 26 are in the same direction as the direction of the horizontal force acting on the building.
Then, the slider lower portion 52 moves on the rail portion 22A of the lower rail 22, the slider upper portion 54 moves on the rail portion 26A of the upper rail 26, and the lower structure 12 and the upper structure 14 pass through the seismic isolation device 10. Displaces relatively horizontally. Even in this case, the load of the upper structure 14 is supported by the lower structure 12 via the plurality of seismic isolation devices 10.
The lower structure 12 and the upper structure 14 are relatively displaced in the horizontal direction. For example, as shown in FIGS. 5 and 6, the slider lower portion 52 is an intermediate portion in the extending direction of the rail portion 22 </ b> A of the lower rail 22. The slider upper part 54 is located in the intermediate part of the extension direction of the rail part 26A of the upper rail 26.

In this state, the distance from the upper surface of the lower rotating body 30 to the slider lower portion 52 is D3, and the distance from the lower surface of the upper rotating body 40 to the slider upper portion 54 is D4.
That is, when the lower structure 12 and the upper structure 14 are relatively displaced in the horizontal direction, the upper structure 14 is displaced from the lower structure 12 by a distance of (D3−D1) + (D4−D2). Will rise.
Therefore, the potential energy of the upper structure 14 corresponding to the distance of (D3−D1) + (D4−D2) is generated, and this time the upper structure 14 tries to return to the original position by this potential energy, and the slider The lower portion 52 moves on the rail portion 22A of the lower rail 22, and the slider upper portion 54 moves on the rail portion 26A of the upper rail 26.
Then, from the state of FIG. 5, the slider lower portion 52 is located in the left half of the lower rail 22, the slider upper portion 54 is located in the right half of the upper rail 26, and the lower structure 12 and the upper structure 14 are relative to each other. The horizontal displacement of the lower structure 12 and the upper structure 14 is repeated repeatedly.
The slider lower portion 52 is applied to the upper structure 14 due to resistance when the rail portion 22A of the lower rail 22 moves, and the slider upper portion 54 due to resistance when the slider upper portion 54 moves the rail portion 26A of the upper rail 26. The energy due to the earthquake is attenuated, and the upper structure 14 eventually returns to the initial position shown in FIGS.

According to the present embodiment, the following effects are achieved.
Since the curved lower rail 22, the curved upper rail 26, and the slider 28 that engages with the rails 22 and 26 are provided, the upper structure 14 is raised with a large stroke by a horizontal force, and a large restoration is performed. It is advantageous in obtaining power.
In addition, when the lower structure 12 and the upper structure 14 are relatively displaced in the horizontal direction, the slider lower part 52 and the curved lower rail 22 move relatively, and the slider upper part 54 becomes the curved upper part. Since the rail portion 26A of the rail 26 moves relatively, a large resistance force is generated between the slider lower portion 52 and the lower rail 22, and between the slider upper portion 54 and the upper rail 26, thereby obtaining a large damping force. Is advantageous.
Therefore, a large restoring force can be obtained without requiring an elastic member such as a spring, and it is not necessary to separately provide a member that exhibits different functions in one device, thereby simplifying the structure and reducing the weight of the seismic isolation device. This is advantageous.
Further, in the present embodiment, the curved lower rail 22 and the curved upper rail 26 face each other and extend on the same straight line when viewed in plan, so that the weight of the upper structure can be reduced. The support capability of the seismic device 10 is large, which is advantageous for stable operation even with heavier structures.

In addition, since the lower rotating mechanism 20 and the upper rotating mechanism 24 are provided, the upper structure 14 can be isolated from the horizontal force in any direction.
Further, with respect to the lifting force due to the earthquake, the slider lower portion 52 is engaged so as not to move upward in the direction away from the rail portion 22A of the lower rail 22, the slider upper portion 54 is moved upward and the upper rail 26A is moved upward. Since it is engaged so that it cannot move in the direction away from it, a pulling-out resistance force is exerted, which is advantageous in preventing unexpected lifting of the upper structure 14.
Therefore, it is possible to obtain the seismic isolation device 10 that has a simple structure, exhibits a load supporting ability, a large restoring force, and a damping force, and can exhibit a pulling-out resistance against the lifting force.
Further, in normal times (when stationary), the upper structure 14 is located at the lowest position. Accordingly, in order for the upper structure 14 to be displaced in the horizontal direction with respect to the lower structure 12, a large amount of energy is required to raise the upper structure 14, and thus the upper structure 14 in a normal state (when stationary). This is advantageous in stabilizing the state.

In addition, the parallel type in which the curved lower rail 22 and the curved upper rail 26 are opposed to each other as in the present embodiment has a large movable range (horizontal deformation amount). Therefore, it is possible to obtain a rolling bearing having a sufficient damping function and restoring function in accordance with the size of any installation space. Specifically, the size of the apparatus can be reduced while having a sufficient attenuation function and restoration function. Theoretically, the size can be reduced to half of the conventional size while maintaining the conventional horizontal deformation amount. By utilizing this, the footing F (refer FIG. 1) of foundation concrete can be made small, the building foundation can be made small as a whole, and it can also contribute to reduction of construction cost.
In addition, as a damping function required for the seismic isolation device, it is necessary to horizontally deform the seismic isolation device with a long cycle (large stroke), and the parallel facing type rolling bearing of the curved rail as in the present invention is movable. Because of its wide range, it can be realized.
In the conventional sliding bearing, the period of vibration attenuation changes depending on the weight of the superstructure (buildings, etc.), but in the configuration of the present invention, since the period of vibration attenuation is determined only by the curvature radius of the rail, Even when the weight of the building such as a distribution warehouse is likely to change, the damping force can be accurately controlled, which is extremely advantageous compared to conventional seismic isolation devices.

The outer peripheral portions of the lower rotating body 30 and the upper rotating body 40 can be rotatably supported by radial bearings, and the lower central shaft 36 and the upper central shaft 46 can be omitted. Providing the lower center shaft 36 and the upper center shaft 46 in the position is advantageous in reducing the size of the seismic isolation device 10.
Further, in addition to the thrust bearing 42, the load of the upper structure 14 may be transmitted to the upper rail 26 by the upper central shaft 46. In this case, it is advantageous in reducing the thickness of the upper rotating body 40. .

DESCRIPTION OF SYMBOLS 10 Seismic isolation device 12 Lower structure 14 Upper structure 20 Lower rotating mechanism 22 Lower rail 24 Upper rotating mechanism 26 Upper rail 28 Slider 30 Lower rotating body 32 Thrust bearing 34 Lower case 36 Lower center axis 40 Upper rotating body 42 Thrust bearing 44 Upper case 46 Upper central axis 50 Main body 52 Lower slider 54 Upper slider

Claims (6)

A seismic isolation device provided between the lower structure and the upper structure,
A lower rotating mechanism provided at an upper portion of the lower structure;
A lower rail that is supported by the lower rotating mechanism so as to be rotatable about a vertical axis, extends at a predetermined curvature, and is located at a position where the central portion in the extending direction is lower than both end portions in the extending direction;
An upper rotating mechanism provided at a lower portion of the upper structure;
An upper rail that is supported by the upper rotation mechanism so as to be rotatable about a vertical axis, extends with a predetermined curvature, and has a central portion in the extending direction higher than both end portions in the extending direction;
It is disposed between the lower rail and the upper rail, transmits the load of the upper structure to the lower structure, engages with the lower rail so as to be movable in the extending direction, and moves upward from the lower rail. The upper rail is movably engaged with the upper rail in the extending direction thereof, and the upper rail is movably engaged with the upper rail. A slider that extends the lower rail and the upper rail on the same straight line when viewed in plan,
A seismic isolation device comprising: The curvature of the lower rail and the curvature of the upper rail are the same,
The seismic isolation device according to claim 1. The lower rotating mechanism includes a disk-shaped lower rotating body attached to the lower rail and supported rotatably about a vertical axis,
The lower rail extends on the diameter of the lower rotating body on the lower rotating body, and a central portion in the extending direction of the lower rail is located on the center of the lower rotating body,
The upper rotating mechanism includes a disk-shaped upper rotating body attached to the upper rail and supported rotatably about a vertical axis,
The upper rail extends on the diameter of the upper rotating body under the upper rotating body, and a central portion in the extending direction of the upper rail is located on the center of the upper rotating body.
The seismic isolation device according to claim 1 or 2. The lower rotating mechanism includes a bearing that rotatably supports the lower rotating body, a lower case that is provided above the lower structure and holds the bearing, and extends vertically through the center of the lower rotating body. A lower central axis inserted through the lower rotating body and the lower case, and a bearing that rotatably supports the lower central axis at least one of the lower rotating body or the lower case,
The upper rotating mechanism includes a bearing that rotatably supports the upper rotating body, an upper case that is provided below the upper structure and holds the bearing, and extends vertically through the center of the upper rotating body. And an upper central axis inserted through the upper rotating body and the upper case, and a bearing that rotatably supports the upper central axis at least one of the upper rotating body or the upper case.
The seismic isolation device according to claim 3. The lower rotating body is rotatably supported by the bearing held by the lower case and is immovable in the vertical direction,
The upper rotating body is rotatably supported by the bearing held by the upper case and is immovable in the vertical direction.
The seismic isolation device according to claim 4. The upper central axis transmits a part of the load of the upper structure to the upper rail.
The seismic isolation device according to claim 4 or 5, characterized in that

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