JP2015036560A - Seismic isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seismic isolator which damps vibrations in all directions on a horizontal surface with a single damper.SOLUTION: A seismic isolator 100 reduces vibrations transmitted to a structure 1 and includes: a movable structure part 10 integrally provided with the structure 1; and a fixed structure part 20 fixed to a ground surface on which the structure 1 is firmly fixed. The movable structure part 10 includes: an upper part taper member 11 where an upper part taper surface 11a inclining toward a center part is formed on a lower surface; and a lower part taper member 12 which is integrally provided with the upper part taper member 11 so as to be positioned below the upper part taper member 11 and spaced a predetermined distance away from the upper part taper member 11, the lower part taper member 12 having an upper surface on which a lower part taper surface 12a having a shape corresponding to the upper part taper surface 11a is formed. The fixed structure part 20 includes a damper 23 including a rod 27, which contacts with the upper part taper surface 11a and the lower part taper surface 12a at both end parts, the damper 23 damping movements of the rod 27 in an axial direction.

Description

  The present invention relates to a seismic isolation device for a structure.

  Conventionally, various types of seismic isolation devices have been used to reduce the vibration of structures due to earthquakes and the like.

  Patent Literature 1 discloses a seismic isolation device that absorbs vibration energy during an earthquake using a damping force of an oil damper that can extend and retract a piston rod in a horizontal direction. In this seismic isolation device, it is possible to dampen vibrations in all directions of 360 degrees on the horizontal plane by including a pair of oil dampers arranged on the horizontal plane by shifting the phase by 90 degrees.

JP 2005-048549 A

  However, in the seismic isolation device of Patent Document 1, each oil damper attenuates vibration in only one direction. Therefore, in order to damp vibrations in all directions on the horizontal plane, it is necessary to provide at least a pair of oil dampers.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a seismic isolation device capable of attenuating vibrations in all directions on a horizontal plane by a single shock absorber.

  The present invention is a seismic isolation device that reduces vibration transmitted to a structure, the movable structure provided integrally with the structure, a fixed structure fixed to the ground on which the structure is fixed, The movable structure portion is integrally formed with the upper taper member having a lower taper formed on the lower surface of the upper taper surface inclined toward the central portion, with a predetermined interval below the upper taper member. A lower taper member formed on the upper surface of the lower taper surface having a shape corresponding to the upper taper surface, and the fixed structure portion has both ends abutting against the upper taper surface and the lower taper surface. It has a buffer which has a rod which touches and attenuates movement of the rod in the direction of an axis.

  In the present invention, when the ground vibrates in the horizontal direction due to an earthquake or the like, the fixed structure portion and the movable structure portion relatively move in the horizontal direction. Therefore, the rod of the shock absorber moves in the axial direction between the upper taper member and the lower taper member, following the taper angle between the upper taper surface and the lower taper surface. Therefore, the relative movement in the horizontal direction between the fixed structure and the movable structure is attenuated by the shock absorber. Therefore, vibrations in all directions on the horizontal plane can be damped by a single shock absorber.

It is a front view of a structure provided with the seismic isolation apparatus which concerns on embodiment of this invention. It is sectional drawing of the front of the seismic isolation apparatus which concerns on embodiment of this invention. It is AA sectional drawing in FIG.

  Hereinafter, a seismic isolation device 100 according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the seismic isolation device 100 supports a structure (upper structure) 1 with respect to the lower structure 2. The seismic isolation device 100 reduces vibrations transmitted to the structure 1. Specifically, the seismic isolation device 100 suppresses transmission of the shaking to the structure 1 when the ground is shaken in the horizontal direction due to an earthquake or the like.

  The structure 1 is a building such as a detached house or a high-rise building, or a structure such as a steel tower or a chimney. Moreover, the structure 1 includes those that are not fixed on land, such as a large computer or a rack installed indoors. In the present embodiment, the structure 1 is a detached house.

  The seismic isolation device 100 moves within a predetermined range in a horizontal direction with respect to the ground, a movable structure 10 provided integrally with the structure 1, a fixed structure 20 fixed to the ground on which the structure 1 is fixed, and And a support member 30 that supports the structure 1 as possible.

  The movable structure 10 includes an upper taper member 11 having an upper taper surface 11a inclined toward the central portion formed on the lower surface, and a lower taper formed with a lower taper surface 12a having a shape corresponding to the upper taper surface 11a on the upper surface. A member 12 and a pair of connecting members 13 that connect the upper tapered member 11 and the lower tapered member 12 are provided.

  The upper taper member 11 is fixed to the lower part of the structure 1. The upper taper member 11 is formed in a substantially cylindrical shape. The upper taper member 11 is disposed such that the central axis faces the vertical direction.

  The upper tapered surface 11a is formed in a mortar shape whose entire circumference is inclined toward the center. The upper tapered surface 11a is formed in a concave shape from the bottom to the top so that the central portion is located at the highest position. An upper end portion 27a of a rod 27 of a shock absorber 23 to be described later comes into contact with the upper tapered surface 11a.

  The lower taper member 12 is provided below the upper taper member 11 with a predetermined interval. The lower taper member 12 is formed in a conical shape and is provided in parallel with the upper taper member 11. The lower taper member 12 is provided integrally with the upper taper member 11 via a pair of connecting members 13.

  The lower tapered surface 12a is formed in a conical shape corresponding to the shape of the upper tapered surface 11a. Therefore, the vertical interval between the lower tapered surface 12a and the upper tapered surface 11a is the same at any position. A lower end portion 27b of a rod 27 of a shock absorber 23 to be described later contacts the lower tapered surface 12a. The rod 27 of the shock absorber 23 can slide in the horizontal direction between the upper tapered surface 11a and the lower tapered surface 12a while facing the vertical direction.

  As shown in FIG. 3, the connecting member 13 vertically connects two locations on the outer periphery of the upper taper member 11 and the lower taper member 12. The connecting member 13 is formed in a rectangular flat plate shape. The connecting member 13 is not limited to a pair, and may be a single member or three or more members.

  As shown in FIG. 1, the fixed structure portion 20 includes a pair of column members 21 erected upward from the lower structure 2, a beam member 22 that connects the upper portions of the pair of column members 21, And a shock absorber 23 provided substantially at the center.

  The column member 21 is provided at a position spaced apart from the outer periphery of the upper taper member 11 and the lower taper member 12 in the horizontal direction. The predetermined distance is set such that the outer circumference of the upper taper member 11 and the lower taper member 12 does not reach when the stroke amount in the horizontal direction of the structure 1 with respect to the lower structure 2 is maximum.

  The beam member 22 is provided horizontally. The beam member 22 supports the shock absorber 23 so as to be positioned between the upper taper member 11 and the lower taper member 12.

  As shown in FIG. 2, the shock absorber 23 includes a cylinder 24 that stores hydraulic oil as a working fluid, a piston 25 that defines a first fluid chamber 28 a and a second fluid chamber 28 b in the cylinder 24, A damping valve 26 for imparting resistance to hydraulic fluid flowing between the first fluid chamber and the second fluid chamber, and a rod 27 fixed to the piston 25 are provided. The shock absorber 23 attenuates the movement of the rod 27 in the axial direction.

  The cylinder 24 is attached to the beam member 22 so that the central axis is oriented in the vertical direction. A rod 27 is inserted through the center of the cylinder 24. The shock absorber 23 is a double rod type in which the rod 27 penetrates from both ends of the cylinder 24 to the outside.

  The piston 25 is positioned approximately at the center in the axial direction of the cylinder 24 when the rod 27 is positioned at the center of the upper tapered surface 11a.

  The damping valve 26 permits only passage of hydraulic oil from the first fluid chamber 28a to the second fluid chamber 28b, and passage of hydraulic oil from the second fluid chamber 28b to the first fluid chamber 28a. And a second damping valve 26b that permits only the above. Thereby, the damping valve 26 generates a damping force even when the piston 25 moves up and down. The damping valve 26 is a relief valve in the present embodiment, but a throttle valve or the like may be applied instead.

  The rod 27 is provided integrally with the piston 25 and penetrates from both ends of the cylinder 24 to the outside. In the rod 27, an upper end portion 27a abuts on the upper tapered surface 11a, and a lower end portion 27b abuts on the lower tapered surface 12a. The rod 27 is located at the center of the upper tapered surface 11a when the ground is not vibrating. When the ground vibrates, the rod 27 slides between the upper tapered surface 11a and the lower tapered surface 12a.

  The support member 30 is a columnar column that is provided in plural and supports the structure 1. The support member 30 generates a restoring force to return to the original position when the structure 1 is shaken. The support member 30 is made of laminated rubber, for example.

  Next, the operation of the seismic isolation device 100 will be described.

  When the ground is not shaking, the rod 27 of the shock absorber 23 is located at the center of the upper tapered surface 11a. As a result, the structure 1 is prevented from shaking due to strong wind acting on the structure 1 or vibrations inside the structure 1.

  When the ground shakes in the horizontal direction due to the earthquake, the lower structure 2 and the fixed structure 20 move in the horizontal direction. The structure 1 tries to stay at that position due to its inertial force. Therefore, the movable structure 10 moves in the horizontal direction with respect to the fixed structure 20.

  When the fixed structure portion 20 and the movable structure portion 10 move relative to each other in the horizontal direction, the shock absorber 23 supported by the column member 21 and the beam member 22 moves horizontally between the upper taper member 11 and the lower taper member 12. Move to. At this time, the rod 27 of the shock absorber 23 moves in the axial direction between the upper taper member 11 and the lower taper member 12 following the taper angle between the upper taper surface 11a and the lower taper surface 12a. Therefore, the relative movement of the fixed structure 20 and the movable structure 10 in the horizontal direction is attenuated by the shock absorber 23. Therefore, vibrations in all directions on the horizontal plane can be damped by the single shock absorber 23.

  Thereby, the structure 1 vibrates with an extremely small amplitude with respect to the amplitude of the ground shaking. As described above, the seismic isolation device 100 can suppress the transmission of the shaking to the structure 1 when the ground is shaken in the horizontal direction due to an earthquake or the like.

  When the earthquake stops, the rod 27 of the shock absorber 23 returns to the central portion of the upper tapered surface 11a by the restoring force of the support member 30.

  Here, in the conventional seismic isolation device, a shock absorber that attenuates vibration in only one direction has been used. And by arranging a pair of shock absorbers whose phases are shifted by 90 degrees on the horizontal plane, vibrations in all directions on the horizontal plane can be attenuated. Therefore, the maximum stroke of each shock absorber needs to be set larger than the maximum value of the amplitude due to the shaking of the structure 1.

  On the other hand, in the seismic isolation device 100, the horizontal vibration of the structure 1 is converted into the vertical direction of the rod 27 of the shock absorber 23. Therefore, the stroke amount of the rod 27 is determined by the taper angle between the upper tapered surface 11a and the lower tapered surface 12a. Therefore, the stroke amount of the rod 27 of the shock absorber 23 can be reduced as compared with the conventional case.

  In addition, the attenuation characteristic can be changed by changing the taper angle between the upper tapered surface 11a and the lower tapered surface 12a. For example, it is possible to switch the attenuation characteristic according to the stroke size by switching the taper angle between the upper tapered surface 11a and the lower tapered surface 12a to two or more stages instead of being constant. In addition, a horizontal plane may be provided at the center of each of the upper taper surface 11a and the lower taper surface 12a so that the rod 27 is stabilized when positioned at the center. Further, the upper tapered surface 11a and the lower tapered surface 12a may be formed into a spherical shape instead of being formed into a tapered shape.

  Further, when the ground shakes in the vertical direction due to the earthquake, the lower structure 2 and the fixed structure portion 20 move in the vertical direction. The structure 1 tries to stay at that position due to its inertial force. Therefore, when the support member 30 expands and contracts, the movable structure 10 moves in the vertical direction with respect to the fixed structure 20.

  When the fixed structure portion 20 and the movable structure portion 10 are relatively moved in the vertical direction, the upper taper member 11 and the lower taper member 12 cause the rod 27 of the shock absorber 23 to vibrate up and down. Therefore, the relative movement in the vertical direction between the fixed structure 20 and the movable structure 10 is attenuated by the shock absorber 23. Therefore, the vibration of the structure 1 can be attenuated not only when the ground shakes in the horizontal direction due to the earthquake, but also when the ground shakes in the vertical direction.

  According to the above embodiment, the following effects are obtained.

  When the ground vibrates in the horizontal direction due to an earthquake or the like, the fixed structure portion 20 and the movable structure portion 10 move relatively in the horizontal direction. Therefore, the rod 27 of the shock absorber 23 moves in the axial direction between the upper taper member 11 and the lower taper member 12 following the taper angle between the upper taper surface 11a and the lower taper surface 12a. Therefore, the relative movement of the fixed structure 20 and the movable structure 10 in the horizontal direction is attenuated by the shock absorber 23. Therefore, vibrations in all directions on the horizontal plane can be damped by the single shock absorber 23.

  Further, when the ground shakes in the vertical direction due to the earthquake, the movable structure portion 10 moves in the vertical direction with respect to the fixed structure portion 20. Therefore, the rod 27 of the shock absorber 23 is vibrated up and down by the upper taper member 11 and the lower taper member 12. Therefore, the relative movement in the vertical direction between the fixed structure 20 and the movable structure 10 is attenuated by the shock absorber 23. Therefore, the vibration of the structure 1 can be damped by the shock absorber 23 not only when the ground is shaken in the horizontal direction due to the earthquake but also when the ground is shaken in the vertical direction.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, in the above embodiment, the upper tapered surface 11a is formed in a mortar shape whose entire circumference is inclined toward the central portion, and the lower tapered surface 12a is formed in a conical shape corresponding to the shape of the upper tapered surface 11a. Is done. Alternatively, the lower tapered surface may be formed in a mortar shape whose entire circumference is inclined toward the central portion, and the upper tapered surface may be formed in a conical shape corresponding to the shape of the lower tapered surface.

  The upper taper surface and the lower taper surface may be flat surfaces that are inclined to face each other with a boundary line as a boundary. In this case, in order to attenuate the vibrations in all directions on the horizontal plane, it is necessary to provide a plurality of seismic isolation devices and arrange the boundary line between the upper tapered surface and the lower tapered surface in different directions on the horizontal plane. There is.

100 Seismic isolation device 1 Structure (superstructure)
2 Lower structure 10 Movable structure 11 Upper taper member 11a Upper taper surface 12 Lower taper member 12a Lower taper surface 20 Fixed structure 23 Shock absorber 24 Cylinder 25 Piston 26 Damping valve 27 Rod 28a First fluid chamber 28b Second fluid chamber 30 Bearing members

Claims (5)

A seismic isolation device that reduces vibration transmitted to a structure,
A movable structure provided integrally with the structure;
A fixed structure portion fixed to the ground on which the structure is fixed,
The movable structure part is
An upper tapered member having an upper tapered surface inclined toward the central portion formed on the lower surface;
A lower taper member provided integrally with the upper taper member at a predetermined interval below the upper taper member and having a lower taper surface having a shape corresponding to the upper taper surface formed on the upper surface;
The seismic isolation device, wherein the fixed structure portion includes a shock absorber having a rod having both end portions in contact with the upper taper surface and the lower taper surface to attenuate movement of the rod in the axial direction. The upper tapered surface is formed in a mortar shape whose entire circumference is inclined toward the central portion,
The seismic isolation device according to claim 1, wherein the lower tapered surface is formed in a conical shape corresponding to the shape of the upper tapered surface.   3. The seismic isolation device according to claim 1, wherein the rod is positioned at the central portion of the upper tapered surface when the ground is not vibrating. 4.   The seismic isolation device according to any one of claims 1 to 3, further comprising a support member that supports the structure so as to be movable within a predetermined range in a horizontal direction with respect to the ground. The shock absorber is configured to flow between the first fluid chamber and the second fluid chamber by defining a first fluid chamber and a second fluid chamber in the cylinder in which the working fluid is accommodated. A piston having a damping valve that imparts resistance to the fluid;
The seismic isolation device according to any one of claims 1 to 4, wherein the rod is provided integrally with the piston and penetrates from both ends of the cylinder to the outside.

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