JP2015021579A - Seismic isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seismic isolation device which keeps rigidity thereof down when a displacement of a structure is relatively small, and exponentially increases the rigidity thereof as the displacement of the structure gets larger when the displacement of the structure is relatively large.SOLUTION: A seismic isolation device 1 connects a base 100 provided with a reference surface 101 parallel to a horizontal plane and a structure 150 arranged on the reference surface so as to be movable on a vertical plane S1. The seismic isolation device 1 comprises: a first link member 15 which has a first edge part 15a connected to the structure through a first connection section 10, rotates around the first connection section 10 with respect to the structure and moves on the vertical plane; a second link member 25 which is connected to a second edge part 15b of the first link member through a second connection section 20, rotates around the second connection section with respect to the first link member and moves on the vertical plane; a restriction section 30 which restricts the second link member so that the same moves in a vertical direction D; and an energizing section 35 which energizes the second link member in a vertically downward direction D1.

Description

  The present invention relates to a seismic isolation device that connects a base and a structure disposed on the base.

Conventionally, many seismic isolation devices used by connecting to structures have been proposed. The most common of these seismic isolation devices has a rolling mechanism using rolling such as laminated rubber or a sphere.
In a structure connected to a seismic isolation device having a laminated rubber, 1 to 10 (s: seconds), which is a periodic band of a long-period earthquake, often becomes the natural period of the structure because of the rigidity of the laminated rubber. For this reason, it is considered that when a long-period earthquake occurs, the laminated rubber deforms beyond the allowable displacement of the laminated rubber.
In addition, if a large number of laminated rubbers are installed to support the load of the structure, the rigidity of the laminated rubber as a whole increases so much that the seismic isolation device impairs the seismic isolation performance. For this reason, the seismic isolation device may use a laminated rubber and a rolling mechanism in combination. Further, since both the laminated rubber and the rolling mechanism are strong against compression but weak against tension, it has been devised separately to provide a seismic isolation device with a pull-out prevention device.

  On the other hand, the rolling mechanism has ideal seismic isolation performance if the rolling surface (reference surface) provided on the base is flat. In this case, the origin return performance of the structure, wind resistance Performance becomes a problem. Therefore, in many cases, both the seismic isolation performance and the wind resistance performance are achieved by making the rolling surface into an arc shape and moving the structure on the rolling surface (see, for example, Patent Document 1). In this case, the return-to-origin performance and wind resistance performance are obtained as a price for reducing the seismic isolation performance by using the arc surface as the rolling surface.

  From the above, it can be seen that in current seismic isolation devices, there is a trade-off between the seismic isolation performance and the wind resistance performance when the displacement is relatively large due to wind or the like, in which both performances do not hold simultaneously. Conventional countermeasures against relatively large displacements are primarily primitive by installing a stopper and fixing a structure arranged on a base. In this case, naturally the seismic isolation performance of the device using the stopper is completely absent.

  As a mechanism corresponding to this, a mechanism using a non-linear characteristic of a spring, such as the seismic isolation device described in Patent Document 2, has been proposed. In this seismic isolation device, a non-linear characteristic is obtained by arranging a spring having a spring axis oblique to the horizontal direction between the fixed base and the base isolation base. The non-linear characteristic mentioned here means a hard spring (gradual hardening) characteristic. While the conventional seismic isolation device has almost constant rigidity with respect to the displacement, in the seismic isolation device of Patent Document 2, the rigidity increases as the displacement of the base isolation table increases. If it has hard spring characteristics, it has seismic isolation performance near the origin where the displacement of the base isolation table is relatively small, wind resistance and earthquake resistance performance when the displacement of the base isolation table is relatively large, as well as base isolation performance and wind resistance performance. Moreover, switching to the seismic performance can be performed smoothly with respect to the displacement of the base isolation table.

Japanese Patent Laid-Open No. 9-296847 JP 2006-342884 A

  However, in the seismic isolation device of Patent Document 2, the nonlinear characteristic of rigidity is obtained, but the rigidity converges to a constant value as the displacement increases. Therefore, the seismic isolation device exhibits the hard spring characteristic when the base isolation table is displaced within a limited range from the origin.

  The present invention has been made in view of such problems. When the displacement of the structure is relatively small, the rigidity is suppressed to be small, and when the displacement of the structure is relatively large, An object of the present invention is to provide a small seismic isolation device whose rigidity increases rapidly as the displacement increases.

In order to solve the above problems, the present invention proposes the following means.
The seismic isolation device of the present invention is a seismic isolation device that connects a base provided with a reference plane parallel to a horizontal plane and a structure arranged on the reference plane and movable in a vertical plane. A first end portion is connected to the structure via a first connection portion, and the first end portion rotates around the first connection portion with respect to the structure and moves on the vertical plane. One link member is connected to the second end portion of the first link member via a second connection portion, and rotates around the second connection portion with respect to the first link member. And a second link member that moves on the vertical surface, a restricting portion that restricts the second link member to move in the vertical direction, and biases the second link member downward in the vertical direction. And an urging unit.

  In addition, another seismic isolation device of the present invention is provided with a base provided with a reference surface formed so as to be recessed vertically downward, and arranged on the reference surface so as to be movable within the vertical surface. A seismic isolation device for connecting the structure with a first end connected to the structure via a first connection portion and rotating around the first connection portion with respect to the structure. A first link member that moves and moves on the vertical plane, and is connected to a second end portion of the first link member via a second connection portion, with respect to the first link member A second link member that rotates around the second connection portion and moves on the vertical plane; a restriction portion that restricts the second link member to move in a vertical direction; and the second link member And an urging portion that urges the link member vertically downward.

  In the seismic isolation device, it is more preferable that a rolling mechanism is provided between the reference surface and the bottom surface of the structure.

  According to the seismic isolation device of the present invention, when the displacement of the structure is relatively small, the rigidity is suppressed to be small, and when the displacement of the structure is relatively large, the rigidity is increased as the displacement of the structure increases. The size can be increased drastically and reduced in size.

It is a schematic diagram when the seismic isolation apparatus of one Embodiment of this invention exists in a neutral state. It is a schematic diagram when the seismic isolation device is in a moving state. It is the figure which modeled only the connection part, link member, and spring member when the seismic isolation device is in a moving state. It is a figure which shows the rigidity curve of the seismic isolation device. It is a figure explaining the effect | action of the seismic isolation apparatus when a structure receives the force by a wind. It is the figure which modeled the oblique spring structure of the seismic isolation apparatus of a comparative example. It is the figure which modeled the circular arc structure of the seismic isolation apparatus of the comparative example. It is a figure which shows the rigidity curve of the seismic isolation apparatus of a comparative example. It is a figure which shows the rigidity curve of the seismic isolation apparatus of a comparative example, and the seismic isolation apparatus of this embodiment. It is a schematic diagram when the seismic isolation apparatus of embodiment of the modification of this invention exists in a neutral state.

Hereinafter, an embodiment of a seismic isolation device according to the present invention will be described with reference to FIGS. 1 to 9.
As shown in FIG. 1, the seismic isolation device 1 includes a base 100 on which a reference surface 101 is provided, and a structure 150 that is arranged on the reference surface 101 so as to be movable on the vertical surface S1. Are connected to each other.
In this example, it is assumed that the reference plane 101 is a plane parallel to the horizontal plane. The structure 150 is not particularly limited, such as a high-rise building or a house.

The seismic isolation device 1 of this embodiment uses a link structure. The seismic isolation device 1 includes a first link member 15 in which a first end 15 a is connected to a structure 150 via a first connection portion 10, and a second end of the first link member 15. A second link member 25 connected to 15b via the second connection portion 20, a restriction portion 30 for restricting the second link member 25 to move in the vertical direction D, and a second link member 25. And a spring member (urging portion) 35 for urging the lower portion toward the vertically downward direction D1.
The link members 15 and 25 and the second connecting portion 20 constitute the link structure 2.
In addition, in FIG. 1, arrangement | positioning of each structure of the seismic isolation apparatus 1 in the neutral state in which the 1st link member 15 is extended in the perpendicular direction D is shown. When the x-axis parallel to the reference plane 101 and the vertical plane S1 is defined, in this neutral state, the relative displacement in the x-axis direction of the structure 150 with respect to the base 100 is zero.

  Moreover, below, for convenience of explanation, the case where the structure 150, the connection portions 10 and 20, and the link members 15 and 25 move only on the vertical plane S1 will be described.

As the connection parts 10 and 20, a well-known universal joint, a gimbal mechanism, a hinge mechanism, etc. can be selected suitably, and a kind will not be ask | required.
The link members 15 and 25 are made of steel or the like in a rod shape, and are configured to be hard enough to be regarded as a rigid body.
Although not shown, the first connecting portion 10 is connected to the bottom surface 151 of the structure 150 and the first end portion 15a of the first link member 15 by high-strength bolts, welding, or the like.
The first link member 15 rotates around the first connection portion 10 with respect to the structure 150. In the neutral state, the second end 15b of the first link member 15 is disposed vertically downward D1 with respect to the first end 15a.

  The length of the second link member 25 is arbitrary as long as the lower end portion 25b of the second link member 25 is separated from the bottom surface of the hole portion 102 when the seismic isolation device 1 is in a neutral state. The second connection portion 20 is connected to the second end portion 15 b of the first link member 15 and the upper end portion 25 a of the second link member 25, respectively. The second link member 25 rotates around the second connection portion 20 with respect to the first link member 15.

In the present embodiment, the restricting portion 30 is mounted in a hole portion 102 formed in the base 100 so as to be recessed from the reference surface 101 toward the vertically downward direction D1. The restriction unit 30 includes a total of four roller units 31 that sandwich the second link member 25 in the x-axis direction and are arranged side by side in the vertical direction D. Each roller unit 31 is configured such that a columnar roller 31b is rotatably supported at the tip of a rod-like support member 31a. The base end portion of the support member 31 a is fixed to the inner surface of the hole portion 102. The roller 31 b is in contact with the side surface of the second link member 25.
The restricting portion 30 constitutes a vertical guide that guides the second link member 25 so as to move only in the vertical direction D.

As the spring member 35, a metal spring such as a coil spring that expands and contracts in one axial direction can be used. In this embodiment, the rigidity of the spring member 35 is a linear characteristic (a characteristic in which the rigidity of the spring member 35 is proportional to the amount of deformation of the spring member 35), but the rigidity of the spring member 35 is relative to the amount of deformation of the spring member 35. Non-linear characteristics that are larger than proportional may be used.
The spring member 35 is arranged in parallel with the second link member 25, the upper end portion is fixed to the second link member 25, and the lower end portion is fixed to the bottom surface of the hole portion 102. That is, the spring member 35 and the second link member 25 are arranged to have a parallel structure. The second link member 25 moves in the vertical direction D, and the spring member 35 expands or contracts accordingly. At this time, since both members are arranged in a parallel structure, the spring member 35 is arranged. The non-interfering structure does not interfere with the movement of the second link member 25.

The non-interference structure between the spring member 35 and the second link member 25 is not limited to this. For example, when the second link member is formed in a columnar shape or a cylindrical shape, the outer peripheral surface of the second link member is formed so that the spring member smoothly expands and contracts on the outer peripheral surface of the second link member. The non-interference structure may be configured by winding the spring member in a coil shape.
When the second link member is formed in a cylindrical shape, even if the spring member is housed in the second link member so that the spring member smoothly expands and contracts within the tube hole of the second link member. Good.
Alternatively, a protrusion may be provided on the surface of the second link member, the spring member may be arranged in parallel with the second link member, and the spring member may be engaged with the protrusion. The spring member may be disposed obliquely with respect to the second link member.

In this example, a support roller (rolling mechanism) 40 is provided between the reference surface 101 of the base 100 and the bottom surface 151 of the structure 150. At least a pair of rollers 40 are arranged so as to sandwich the first link member 15 in the x-axis direction.
When the seismic isolation device 1 is in a neutral state, the lower end portion 25 b of the second link member 25 is separated from the bottom surface of the hole portion 102. When the seismic isolation device 1 is in a neutral state, the second connection portion 20 may be located on the reference plane 101 or may not be located on the reference plane 101.

Next, the operation of the seismic isolation device 1 configured as described above will be described.
A moving state in which the structure 150 moves in the x-axis direction on the vertical plane S1 with respect to the reference plane 101 as shown in FIG. 2 from the state where the seismic isolation device 1 shown in FIG. 1 is in a neutral state will be described. In this example, the case where the structure 150 moves in the positive direction of the x axis is shown. The first connecting part 10 moves together with the structure 150 in the positive direction of the x-axis.
Since the second link member 25 is guided by the restricting portion 30 so as to move in the vertical direction D, the first link member 15 changes its direction as the first connecting portion 10 moves, and The second link member 25 moves vertically upward D2.
When the structure 150 moves in the x-axis direction, the support roller 40 rolls between the reference surface 101 of the base 100 and the bottom surface 151 of the structure 150.

For example, when the base 100 moves due to an earthquake, even if the second link member 25 moves vertically upward D2, the spring member 35 only extends in the vertical direction D, and the horizontal component of the spring member 35 relative to the base 100 is obtained. The power of is not generated.
As the second link member 25 moves vertically upward D2, the spring member 35 extends, but the rigidity change of the link structure 2 of the seismic isolation device 1 with respect to the displacement of the structure 150 from the neutral state in the x-axis direction. This will be described in detail below.

In the model shown in FIG. 3, only the connecting portions 10 and 20, the link members 15 and 25, and the spring member 35 are shown for the seismic isolation device 1. It is assumed that there is no frictional resistance between the reference surface 101 of the base 100 and the bottom surface 151 of the structure 150 and the support roller 40.
The length of the first link member 15 is L, the mass is m ₁ , and the mass of the second link member 25 is m ₂ . The spring stiffness (spring constant) of the spring member 35 is k, and the gravitational acceleration is g.
The displacement in which the structure 150 has moved in the x-axis direction from the neutral state on the vertical plane S1 is x, and the distance in the vertical direction D between the first connection portion 10 and the second connection portion 20 at this time is y. . The extension amount of the spring member 35 with respect to the neutral state (the amount of movement of the second link member 25 in the vertical upward direction D2) is Δ, and the angle between the first link member 15 and the vertical direction D is θ.

In the moving state shown in FIG. 3, the end point 15 c on the first end 15 a side of the first link member 15 has a force F _{x in} the x-axis direction along the horizontal plane and a vertical drag N in the vertical direction D. Each is acting. On the other hand, at the end point 15d on the second end 15b side of the first link member 15, the drag P from the hole 102, that is, the restricting portion 30 in the x-axis direction is applied to the spring member 35 in the vertical direction D. The tensile force kΔ and the gravity m ₂ g of the second link member 25 are acting respectively.
Further, gravity m ₁ g acts on the first link member 15.

Here, if the rigidity of the link structure 2 to obtain a _{K x,} the stiffness _{K x} is determined by (1).
K _x = F _x / x (1)
From the balance of the forces acting on the first link member 15, the equations (2) and (3) are obtained.
F _x = P (2)
N = (m ₁ + m ₂ ) g + kΔ (3)
If the center of gravity of the first link member 15 is the center in the longitudinal direction of the first link member 15, the following equations (4) and (5) are obtained from the rotational balance of the end points 15 c of the first link member 15. .

Here, equation (8) is obtained from the relationship between the following equations (6) and (7).
x = Lsinθ (6)
Δ = L (1-cos θ) (7)

In the equation (8), as the angle θ approaches π / 2 (rad: radians), the stiffness K _x approaches infinity.
Note that the first term, which is a term related to the mass in the numerator of formula (8), is generally smaller than the spring stiffness k. For this reason, most of the characteristics of the stiffness K _x are determined by the spring stiffness k.
Figure 4 shows the seismic isolation device represents a stiffness K _x Link Structure 2 (8). In FIG. 4, the horizontal axis represents the displacement x of the structure 150, and the vertical axis represents the rigidity K _x of the link structure 2. It can be seen that the rigidity curve of the link structure 2 exhibits a hard spring (gradual hardening) characteristic in which the rigidity K _x increases as the displacement of the structure 150 in the x-axis direction increases.
More specifically, when the displacement of the structure 150 is 0, the stiffness K _x is a value according to equation (9) in which the angle θ is 0 in equation (8).

When the displacement of the structure 150 is relatively small, the stiffness K _x becomes a relatively small value close to the value according to the equation (9).
According to the displacement of the structure 150 approaches the length L of the first link member 15, the stiffness K _x approaches infinity steeply increased. That is, when the displacement of the structure 150 is relatively large, the rigidity increases rapidly as the displacement of the structure 150 increases. When the displacement of the structure 150 is close to the length L, by the stiffness K _x is greater, the link structure 2 will exhibit excellent earthquake resistance.
The difference in the characteristics of the rigidity curve is small when the structure 150 is displaced by a certain length in the x-axis direction, and the extension amount of the spring member 35 is small when the displacement of the structure 150 is relatively small. When the displacement of 150 is relatively large, it is caused by a sudden increase.
The seismic isolation device 1 of this embodiment is bent at the second connection portion 20 of the link structure 2 and has rigidity by extending and contracting the spring member 35 in the vertical direction D. The seismic isolation device 1 obtains nonlinear characteristics using nonlinearity existing between the displacement amount of the first link member 15 in the x-axis direction and the displacement amount of the second link member 25 in the vertical direction D. become.

(Example)
Here, although the structure of the seismic isolation device 1 is shown and described in more detail, the configuration of the seismic isolation device 1 is not limited to this.
As an example of the seismic isolation device 1, the link members 15 and 25 are formed of iron in a columnar shape, and the outer diameter φ is 0.1 (m). The length L of the first link member 15 is 0.5 (m), and the length of the second link member 25 is 1.0 (m). The density of iron is 7850 (kg / m ³ ), and the gravitational acceleration g is 9.81 (m / s ² ).
At this time, the value of equation (9) is as shown in equation (10).

Generally, the rigidity K _{x of} one laminated rubber having an outer diameter φ of 0.5 to 1 (m) is on the order of 10 ⁶ (N / m). In contrast stiffness K _x of the link structure 2 the seismic isolation device 1 is about 1/1000, it is understood just how little rigid.
Since the stiffness K _x link structure 2 is small, it is found to have a seismic isolation device 1 excellent seismic isolation performance.

In order to ensure the seismic isolation performance even when the displacement of the structure 150 due to the earthquake increases, the seismic isolation device 1 is set as follows. That is, the maximum value of the predicted displacement of the base 100, shown in FIG. 4, the length of the first link member 15 as the stiffness K _x enters the relatively small seismic isolation region R L, and a spring member 35 The spring stiffness k is determined.
More specifically, estimates the maximum displacement _{x max} of the structure 150, determines the angle theta _max corresponding to the maximum displacement _{x max.}
Next, the length L of the first link member 15 is determined in consideration of the maximum displacement _xmax or more and the maximum space allowed in the structure of the seismic isolation device 1 and the structure 150.
Subsequently, the spring stiffness k is calculated from the equation (8) so that the desired seismic isolation performance can be secured with the maximum displacement _xmax .

As shown in FIG. 5, when the structure 150 receives a force F due to wind, the theoretical displacement x of the structure 150 in the x-axis direction approaches the length L of the first link member 15. The rigidity K _x of the link structure 2 approaches infinity. However, in practice, the displacement x is not equal to the length L, and the displacement x is smaller than the length L. For this reason, it is necessary to ensure a wind-resistant stroke so that the structure 150 can move the length L when it is the longest.
When the seismic isolation device 1 is resistant to wind, the displacement x of the structure 150 is relatively large, so that the rigidity K _x of the link structure 2 is increased, and the seismic isolation device 1 has more seismic performance than seismic performance. Becomes prominent.

Here, as a comparative example, a result obtained by analyzing the actions of Patent Documents 1 and 2 will be described.
In the seismic isolation device of Patent Document 2 (because the slant spring 210 is used as will be described later, it is also referred to as a “slanted spring structure” hereinafter). Therefore, only the oblique spring structure is rewritten and shown in FIG.
The length of the slant spring 210 when no load is applied is L, the spring rigidity of the slant spring 210 is k, the extension amount of the slant spring 210 when the base and the structure (not shown) are relative displacement x, Δ, Let θ be the angle formed with the direction. A force F _x is applied in the horizontal direction and a vertical drag N is applied in the vertical direction to the end point 210a of the oblique spring 210 on the first hinge 215 side.

Here, assuming that the rigidity required by the seismic isolation device 200 is K _x , the rigidity K _x is obtained by the equation (11).
K _x = F _x / x (11)
From the balance of the forces acting on the oblique spring 210, the equations (12) and (13) are obtained.
F _x = kΔsinθ (12)
N = kΔcos θ (13)

Here, equation (16) is obtained from the relationship between the following equations (14) and (15).
x = Ltanθ (14)
Δ = L (1 / cos θ−1) (15)

In the seismic isolation device 200 of this comparative example, as the angle θ approaches π / 2 (rad), the stiffness K _x approaches k, which is a finite value. When the displacement of the structure approaches π / 2 (rad) and becomes relatively large, the stiffness K _x does not increase rapidly.

Next, the rigidity of the seismic isolation device of Patent Document 1 will be described with reference to FIG.
The radius of the arc-shaped support surface 261 of the saucer 260 corresponding to the base is r, and the normal line and the vertical direction at the contact point between the support surface 261 and the sphere 265 when the saucer 260 and the structure 150 are at the relative displacement x. Let the angle be θ.
A force F _x is applied to the structure 150 in the horizontal direction, a vertical drag N is applied in parallel to the normal line, and a gravity Mg is applied to the center of gravity of the structure 150.

Here, assuming that the stiffness required by the seismic isolation device 250 (hereinafter also referred to as “arc structure”) is K _x , the stiffness K _x is obtained by the equation (17).
K _x = F _x / x (17)
When the number of balls 265 rolling on the support surface 261 is n (n = 2 in FIG. 7), the following equations (18) to (20) are obtained from the balance of forces.
nN = Mgcos θ + F _x sin θ (18)
F _x cos θ = Mg sin θ (19)
∴F _x = Mgtanθ (20)

Here, equation (22) is obtained from equation (21) below.
x = rsinθ (21)

In the seismic isolation device 250 of this comparative example, the stiffness K _x approaches infinity as the angle θ approaches π / 2 (rad).

Here, the rigidity curves of the seismic isolation device 1 of the present embodiment and the seismic isolation devices 200 and 250 of the comparative example described above are compared.
The graph of the equation (8) representing the rigidity K _x of the seismic isolation device 1 has already been shown in FIG. In addition, the graph of (8) type | formula of the link structure of this seismic isolation apparatus 1 is shown as curve A1 in FIG. It represents the stiffness _{K x} of the seismic isolation device 200 using the oblique spring 210 a graph of equation (16), shown in FIG. It represents the stiffness _{K x} of the seismic isolation device 250 which uses an arc-shaped support surface 261 (22), shown as curve A3 in Fig.
In any of FIGS. 8 and 9, the horizontal axis shows the displacement x of such structure 150, showing the stiffness K _x of the seismic isolation device on the vertical axis.

As shown in FIG. 8, the stiffness of the oblique spring structure of the comparative example has a non-linear characteristic. However, when the displacement increases, the stiffness converges to the spring stiffness k which is the original stiffness of the spring.
On the other hand, the link structure according to the present embodiment dramatically increases the rigidity when the displacement increases, and is amplified more than the original spring rigidity k of the spring member 35. As a result, the rigidity of the seismic isolation device when the displacement is excessive, that is, the displacement is relatively large, is ensured, and the link structure is superior to the oblique spring structure.
As shown in FIG. 9, the arc structure of the comparative example has rigidity characteristics similar to those of the link structure of this embodiment, but the origin, that is, the rigidity value K0 when the displacement is ₀ is different. Although link structures stiffness value K ₀ for link small mass is small, the stiffness value K ₀ Compared to link structure because the mass of the structure is large in the arc structure becomes significantly large value. For this reason, the link structure has better seismic isolation performance than the arc structure.
In general, since the radius r of the support surface 261 is increased in order to ensure seismic isolation performance, the radius r is longer than the length L of the first link member 15. Therefore, if the displacement becomes larger than the intersection A5 between the curve A1 and the curve A3, the link structure is now more rigid. Therefore, the link structure is superior to the arc structure from the viewpoint of exhibiting wind resistance performance in a small size.

In addition, the length of the 1st link member 15 is set to L etc. similarly to what prescribed | regulated the item of link structure when FIG. 3 was demonstrated. At this time, in the link structure, the stiffness value K ₀ when the displacement is 0 is substantially equal to 1.5 × 10 ³ (N / m).
In order to obtain the same stiffness value with an arc structure, it is as follows. As an example in which the mass of a structure can be estimated to be small, a detached first floor is assumed as a structure. When the unit area mass of the structure is 10 ³ (kg / m ² ) and the area is 10 ² (m ² ), the mass of the structure is 10 ³ (kg / m ² ) × 10 ² (m ² ) = 10 ⁵ (kg).
Therefore, the radius r of the support surface 261 can be obtained from the equation (23).
r = Mg / K ₀ = 10 ⁵ (kg) × 9.81 (m / s ² ) /1.5×10 ³ (N / m) ≈650 (m) (23)

  Therefore, if the rigidity corresponding to the length 0.5 (m) of the first link member 15 of the link structure is to be obtained in the vicinity of the origin, the radius r of the support surface 261 is 650 (m) in the arc structure. Necessary.

On the other hand, in order to obtain a sufficient wind resistance performance with an arc structure, an arc of nearly half a circle is required, which means that the length (height) between layers of a building is required to be 650 (m). Meaning is unrealistic. For this reason, in general seismic isolation devices, instead of taking a large radius r of the support surface 261 at the expense of wind resistance, the support surface 261 uses only a portion of the arc that is nearly parallel to the horizontal plane to achieve seismic isolation performance. Secured.
On the other hand, in the link structure of the present embodiment, since the rigidity rapidly increases as the displacement of the structure 150 approaches the length L of the first link member 15, the length L of the first link member 15 is increased. It is possible to obtain a sufficient wind resistance performance with only the stroke. For this reason, the seismic isolation apparatus 1 can be comprised small.

  From the above, the link structure has characteristics of lower rigidity when the displacement is small and higher rigidity when the displacement is large compared to the arc structure. It can be seen that the wind resistance performance and excessive displacement suppression in the region are excellent.

As described above, according to the seismic isolation device 1 of the present embodiment, when the displacement of the structure 150 is relatively small from the neutral state of the seismic isolation device 1, the amount of extension of the spring member 35 is small. The stiffness K _x of the seismic device 1 can be suppressed to a relatively small value close to the value according to the equation (9).
On the other hand, when the displacement of the structure 150 is large enough to approach the length L of the first link member 15, the extension amount of the spring member 35 and the seismic isolation device 1 are increased as the displacement of the structure 150 increases. it is possible to increase the stiffness K _x abruptly.
A support roller 40 is provided between the reference surface 101 of the base 100 and the bottom surface 151 of the structure 150. When the support roller 40 rolls on the reference surface 101, the structure 150 can move on the reference surface 101 in the x-axis direction while suppressing frictional resistance.

In the seismic isolation device 1 of this embodiment, in order to satisfy seismic isolation performance, excessive displacement suppression, and wind resistance performance, the force of the spring member 35 installed in the vertical direction D is applied in the horizontal direction (x-axis direction) using the link structure 2. ) With this structure, the spring stiffness of the spring member 35 is converted into hard spring characteristics. Due to the hard spring characteristics of the link structure 2, the rigidity of the link structure 2 is small near the origin where the displacement of the structure 150 is close to 0, and the rigidity increases as the distance from the origin increases, and the displacement reaches its maximum length L. Then, the rigidity can be theoretically infinite.
For this reason, unlike the above-mentioned patent document 2, excessive displacement suppression and wind resistance performance are not limited. Moreover, since the structure 150 and the base 100 are connected via the connection parts 10 and 20 and the link members 15 and 25, it corresponds also to extraction.

  The link structure 2 is a non-linear conversion device, and in this embodiment, the spring member 35 is connected to the link structure 2 so that the link structure 2 converts the rigidity of the spring member 35 into one having non-linear characteristics.

Generally, in a conventional seismic isolation device of a so-called rolling type having a rolling mechanism such as a support roller 40, a fixed stopper is attached to improve wind resistance performance, or a fixing device is used based on prior information on earthquakes. Taking measures such as inserting and removing pins etc. As a result, switching between wind resistance performance and seismic isolation performance is accompanied by discontinuity. When a fixed stopper is used, a large impact force is generated when a structure comes into contact with the fixed stopper due to a remarkable discontinuity. In addition, when inserting and removing pins based on prior information, there is a possibility that the power supply of the actuator to be inserted and removed in an emergency may not be secured, and if there is no switching by pins, it becomes an alternative of wind resistance performance and seismic isolation performance. Only one of the seismic isolation performance can be implemented.
On the other hand, since the seismic isolation device 1 of this embodiment uses the rigidity of the hard spring characteristic, the continuity between the seismic isolation performance and the wind resistance performance is the form of continuity between the seismic isolation performance and the earthquake resistance performance. It is excellent in that it is secured by.

Here, the effect of the seismic isolation apparatus 1 of this embodiment is summarized.
・ High seismic isolation performance.
Since the rigidity of the link structure 2 is very small in most of the movable range of the structure 150, the seismic isolation performance is high.
・ High wind resistance.
At the time of wind resistance receiving a force by wind, the displacement of the structure 150 is increased and the rigidity of the link structure 2 is increased, so that the wind resistance performance is high.
・ Excellent suppression of excessive displacement.
Since the rigidity of the link structure 2 has a hard spring characteristic, the rigidity of the link structure 2 increases as the displacement increases, and the excessive displacement suppression capability also increases.
・ Pull out.
Since the base 100 and the structure 150 are connected via the connection portions 10 and 20, the link members 15 and 25, and the spring member 35, the structure 150 and the seismic isolation device 1 are not easily pulled out from the base 100, Also strong against.
・ Retrofit is possible.
Since the link structure 2 does not have a mechanism for supporting the weight of the structure 150, the link structure 2 can be installed later independently from the conventional seismic isolation devices such as laminated rubber, sliding, and rolling. For this reason, retrofit which is remodeling and modification of the conventional seismic isolation device is possible.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications and combinations of configurations within the scope not departing from the gist of the present invention are also possible. included.
For example, in the said embodiment, when the seismic isolation apparatus 1 is a neutral state, the lower end part 25b of the 2nd link member 25 may contact | abut to the bottom face of the hole part 102. FIG. When the second link member 25 abuts on the hole 102, the neutral seismic isolation device 1 can be further stabilized.

In the said embodiment, the structure 150, the connection parts 10 and 20, and the link members 15 and 25 demonstrated in the case of moving two-dimensionally only on the vertical surface S1. However, the structure 150 moves on the reference plane 101 not only on the vertical plane S1 but also in a direction intersecting the vertical plane S1, and the connecting portions 10 and 20 and the link members 15 and 25 move three-dimensionally. The movement of the seismic isolation device 1 of the present invention may be expanded. By providing the above-described universal joint or the like as the connecting portions 10 and 20, the above-described operation can be generated on the surface in any direction around the central axis C in FIG.
That is, regardless of the direction around the central axis C, the rigidity of the seismic isolation device 1 is kept small near the neutral state, and the displacement of the structure 150 from the central axis C is near the length L of the first link member 15. The rigidity of the seismic isolation device 1 can be increased rapidly.

  The support roller 40 is provided between the reference surface 101 of the base 100 and the bottom surface 151 of the structure 150. However, instead of the support roller 40, a sliding mechanism may be formed between the reference surface 101 and the bottom surface 151 by providing a known coating layer having a low friction coefficient on the reference surface 101 and the bottom surface 151, respectively.

As shown in FIG. 10, the reference surface 105 may be formed so as to be recessed downward in the vertical direction D1. In this case, it is preferable that the bottom of the reference plane 105 that is the most vertically downward D1 coincides with the hole 102 in the x-axis direction.
With such a configuration, the structure 150 is stabilized on the hole 102 whose displacement is zero due to the gravity acting on the structure 150. Therefore, the movement of the structure 150 can be further stabilized.
In the present embodiment, the base is the base 100, but the base is not limited to this, and may be the foundation of a structure.

DESCRIPTION OF SYMBOLS 1 Seismic isolation device 10 1st connection part 15 1st link member 15a 1st edge part 15b 2nd edge part 20 2nd connection part 25 2nd link member 30 Control part 35 Spring member (biasing part) )
40 Support roller (rolling mechanism)
100 foundation (base)
101, 105 Reference plane 150 Structure D Vertical direction D1 Vertical downward S1 Vertical plane

Claims (3)

A seismic isolation device for connecting a base provided with a reference plane parallel to a horizontal plane and a structure arranged on the reference plane and movable on a vertical plane,
A first link having a first end connected to the structure via a first connection portion, rotating around the first connection portion with respect to the structure and moving on the vertical plane Members,
It is connected to the second end of the first link member via a second connection portion, rotates around the second connection portion with respect to the first link member, and on the vertical plane. A second link member that moves;
A restricting portion for restricting the second link member to move in the vertical direction;
A biasing portion that biases the second link member vertically downward;
A seismic isolation device comprising: A seismic isolation device that connects a base provided with a reference surface formed so as to be recessed vertically downward and a structure arranged on the reference surface so as to be movable on the vertical surface. And
A first link having a first end connected to the structure via a first connection portion, rotating around the first connection portion with respect to the structure and moving on the vertical plane Members,
It is connected to the second end of the first link member via a second connection portion, rotates around the second connection portion with respect to the first link member, and on the vertical plane. A second link member that moves;
A restricting portion for restricting the second link member to move in the vertical direction;
A biasing portion that biases the second link member vertically downward;
A seismic isolation device comprising:   The seismic isolation device according to claim 1, wherein a rolling mechanism is provided between the reference surface and a bottom surface of the structure.

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