JP2000087592A - Small-stroke vibration isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a device in a comparatively simple structure, to facilitate even installation and to reduce manufacturing cost and construction cost in a small-stroke vibration isolation device, by which an object to be vibration- isolated is vibrated in approximately the same phase as a supporting structure. SOLUTION: An independent rotational-inertia adding device 2 converting relative displacement in the specific directions of an object to be vibration- isolated (such as a vibration-isolating floor, various equipments, a building frame, etc.), A and a supporting structure (such as a slab for a building, the lower foundation of the building, etc.), B into a rotary motion in rotational inertia 5 through a sliding rod 3, a rack 8 and a gear 12 is disposed between the object to be vibration-isolated A and the supporting structure B, the end section of the sliding rod 3 is connected to the object to be vibration-isolated A horizontally rotatably by a vertical pin 11, and rotational inertia 5 is set and fixed onto the supporting structure B horizontally rotatably by a shaft 6 and a bearing 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-stroke seismic isolation device for seismically isolating a base-isolated floor of a building or a building frame.

[0002]

2. Description of the Related Art Seismic isolation devices using rolling bearings, sliding bearings, and the like have already been put into practical use in order to reduce vibrations of floors, various devices, and the like during earthquakes. In addition, these seismic isolation devices are provided with an oil damper, a friction damper, and the like in order to suppress a relative displacement during an earthquake.

[0003]

However, when the stroke is reduced by a conventional damping mechanism such as a damper, the seismic isolation target (such as a seismic isolation floor) and the supporting structure (such as a slab of a building) on which the seismic isolation target is installed are provided. There is a problem that the seismic isolation performance is greatly deteriorated due to the phase difference in the vibration of ()).

In order to solve such problems, the present inventors have proposed a small-stroke seismic isolation device in which a rotary inertia mechanism is added between a seismic isolation target and a support structure, and have already filed an application. (Japanese Patent Application No. 9-140296, Japanese Patent Application No. 10-1009)
No. 45).

This small-stroke seismic isolation device has a rolling bearing and a sliding bearing between the seismic isolation target and the support structure, and also suppresses the displacement of the seismic isolation target due to an earthquake input to return to the origin. In a seismic isolation structure provided with a spring element that imparts vibration, the seismic isolation object and the support structure are connected by a rotary inertia mechanism that converts the relative displacement of the seismic isolation object and the support structure in a specific direction into rotational motion. The basic structure is that the object vibrates in almost the same phase as the support structure.Since the vibration is in almost the same phase, a larger relative displacement with the same relative displacement compared to a damping mechanism such as a conventional damper Seismic isolation effect is obtained,
Conversely, the stroke for obtaining the same seismic isolation effect can be reduced.

However, in the device example presented here, a rotary inertia mechanism is constituted by a ball screw rotatably supported at both ends and a slider (ball nut) screwed to the ball screw, and the ball screw and the slider are each an object to be isolated. A ball screw as a rotary inertia is rotated by moving the slider. The ball screw and the slider are provided between the seismic isolation target and the support structure in order to work in two orthogonal directions. Need to be arranged in a two-tiered manner, the structure becomes complicated, and the installation is troublesome, so that there is a problem that the manufacturing cost and the construction cost of the device are increased.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a device having a relatively simple structure, to be easily mounted, and to reduce manufacturing and construction costs. It is an object of the present invention to provide a small-stroke seismic isolation device that can perform the above-described steps.

[0008]

A small-stroke seismic isolation device according to the present invention includes a seismic isolation target (seismic isolation floor, various devices, a building frame, etc.) and a support structure (a building slab, a building lower foundation, etc.). Is provided independently between the seismic isolation target object and the rotational inertia adding device that converts the relative displacement of the support structure in a specific direction into the rotational motion of the rotational inertia via the linear motion member. The support structure is attached to each of the support structures by a pin, a bearing, or the like so as to be horizontally rotatable (claim 1).

For example, as shown in FIG. 1, a rotary inertia adding device has a slide member (such as a slide rod) having a rack on a side surface and having a base end attached to an object to be seismically isolated by a pin so as to be horizontally rotatable. The rack has gears that mesh with each other, and has a rotational inertia supported on a support structure by a shaft, a thrust bearing, or the like so as to be horizontally rotatable (claim 2).

Alternatively, as shown in FIG. 3, the rotary inertia adding apparatus has a slide member (such as a slide case) having a ball nut at a distal end and a base end rotatably mounted on an object to be seismically isolated by a pin with a pin. ), A rotary inertia having a ball screw screwed into the ball nut, and a fixed member (a fixed side case or the like) rotatably supporting the rotary inertia and attached to a support base on the support structure so as to be horizontally rotatable by a pin. ) (Claim 3).

The seismic isolation target is supported on the supporting structure by a rolling bearing or a sliding bearing, which is a bearing mechanism having a small friction, as in the prior art. The spring element (coil spring, rubber,
Alternatively, a device using electromagnetism, a device using a curved sliding surface and utilizing potential energy, etc.) may be provided, and a damper element (elasto-plastic damper, viscous damper, etc.) may be used together.

In the above configuration, depending on the sectional shape of the seismic isolation target, it may be possible to perform seismic isolation in one direction. In this case, the direction of the slide axis of the rotary inertia adding device is made to coincide with the one direction. It is necessary to arrange a rotary inertia adding device between the seismic isolation target and the support structure to deal with the seismic motion in all directions. In this case, for example, two orthogonal X and Y directions are specified. Rotational inertia adding devices are arranged parallel to each direction as the direction, and the slide member of the rotary inertia adding device is attached to the seismic isolation target via a pin or the like, and the rotational inertia is set to the shaft / thrust bearing or pin /
It is installed and fixed to the support structure with a support base or the like.

When the seismic isolation target and the support structure move relative to each other due to an earthquake or the like, the slide member moves with respect to the fixed rotational inertia, and the rotational inertia rotates via a rack / gear or a ball screw / ball nut. A displacement suppressing effect can be obtained. Since the seismic isolation target vibrates in almost the same phase as the supporting structure, a greater seismic isolation effect can be obtained with the same relative displacement compared to the conventional seismic isolation device using a damper. Can be made smaller. Also, for relative movement of the seismic isolation target that is different from the installation direction of the rotary inertia adding device, the slide member tilts horizontally around the pin, and the rotary inertia is rotated horizontally by bearings and pins, or horizontally. The tilting prevents the device from being broken or damaged.

Since the rotary inertia adding device can be an independent device including a slide member that moves in the axial direction and a rotary inertia rotated by the slide member, the slide member and the rotary inertia are mounted so as to be horizontally rotatable. As a result, it is possible to absorb a force other than the seismic isolation direction of the device, simplify the structure of the device, install and fix the rotational inertia on the support structure, and pin the end of the slide member with a pin. Since it is only necessary to fix to the seismic isolation target, even if it is arranged in two orthogonal directions, it is only necessary to install an independent rotary inertia adding device in parallel with each direction, so installation and installation can be easily performed it can.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. This embodiment is an example in which the small-stroke seismic isolation device of the present invention is applied to a seismic isolation floor and various devices. 1 and 2 show the structure and operation of a rack type seismic isolation device of the present invention. FIGS. 3 and 4 show the structure and operation of the ball screw type of the small-stroke seismic isolation device of the present invention. FIG.
Shows an example in which the small-stroke seismic isolation device of the present invention is applied to a seismic isolation floor. (A) Rack type In FIG. 1, a small-stroke seismic isolation device 1 can horizontally rotate a slide rod 3 of a rack-type rotary inertia adding device 2 to a seismic isolation target A such as a seismic isolation floor via a pin joint 4. , And the shaft 6 of the rotary inertia 5 of the rotary inertia adding device 2 is mounted on a support structure B such as a fixed floor via a thrust bearing 7 so as to be horizontally rotatable.

The slide rod 3 is a rectangular member having a predetermined length arranged horizontally. A rack 8 is fixed on one side surface over a predetermined length, and a guide rail 9a of a linear guide 9 is fixed on the other side surface. Fixed over the span. The base end of the slide rod 3 on the seismic isolation target side is attached to the side surface or the lower surface of the seismic isolation target A by the pin joint 4.

The pin joint 4 is fixed to the base end of the slide rod 3 and is connected via a vertical pin 11 to a pair of mounting brackets 10 protruding from the seismic isolation target A. Is supported rotatably in the horizontal direction.

The rotary inertia 5 is a disk-shaped inertia placed horizontally, and is fixed to the upper part of the shaft 6. A lower portion of the shaft 6 is rotatably supported by a thrust bearing 7, a gear 12 meshing with a rack 8 is fixed to an intermediate portion of the shaft 6, and the shaft 6 and the rotational inertia 5 are moved by the axial movement of the slide rod 3. Rotates horizontally.

A guide 13 in the form of a case that covers the gear 12 is attached to the shaft 6 via a bearing 14. The slider 9b of the linear guide 9 is fixed to the inner surface of the guide 13, and the guide 13 is connected to the guide 13. The slide rod 3, the rack 8, and the guide rail 9a are slidably held between the gear 12 and the slider 9b so that the rack 8
The gear 12 is prevented from being disengaged.

As shown in FIG. 2, the small-stroke seismic isolation device 1 having the above-described configuration is installed so that the slide rod 3 extends along the X direction. , The relative movement in the axial direction of the slide rod 3 is converted into the rotational movement of the rotary inertia 5 via the rack 8, the gear 12, and the shaft 6, and the rotation of the rotary inertia 5 suppresses displacement. The effect is obtained. Since the seismic isolation target A vibrates in substantially the same phase as the support structure B, a greater seismic isolation effect can be obtained with the same relative displacement compared to the conventional seismic isolation device using a damper, and conversely, the same seismic isolation effect can be obtained. The stroke to obtain can be small.

When the seismic isolation object A moves relative to the support structure B in the Y direction, the slide rod 3 tilts about the vertical pin 11 with respect to the rotary inertia 5 to slightly rotate the rotary inertia 5, Thus, destruction or damage of the device due to relative movement in the Y direction can be prevented. In addition, the rotational inertia 5
Hardly rotates, so the seismic isolation effect in the Y direction cannot be obtained.
The seismic isolation effect can be obtained only in the X direction. (B) Ball Screw Type In FIG. 3, a small stroke seismic isolation device 21 is a ball screw type rotary inertia adding device 22 and a slide case 24 having a ball nut 23.
To be rotatable horizontally via a pin joint 25,
Ball screw 26 and rotary inertia 27 of rotary inertia adding device 22
The fixed-side case 28 having a support structure B such as a fixed floor
, Via a pin joint 29 and a fixed-side support base 30 so as to be horizontally rotatable.

The ball nut 23 and the ball screw 26 are generally used linear motion mechanisms having extremely small frictional resistance in which a ball circulates between a male screw and a female screw.
Is fixed to the opening end of the cylindrical slide case 24 on the anti-seismic object side, and the base end of the slide case 24 on the anti-seismic object side is attached to the side surface or the lower surface of the seismic isolation object A by the pin joint 25. Mounted.

The pin joint 25 is connected to the slide case 2
4 and connected via a vertical pin 32 to a pair of mounting brackets 31 protruding from the seismic isolation target A to support the horizontally arranged slide case 24 so as to be rotatable in the horizontal direction.

The ball screw 26 and the rotary inertia 27 are accommodated in a fixed side case 28 so that the central axes thereof are horizontal. The ball screw 26 is formed so as to project horizontally at the center of the rotary inertia 27 toward the seismic isolation target. Fixed, ball nut 23
Screwed.

The fixed case 28 comprises a main body 28a on the anti-seismic object side and a cylindrical guide 28b on the anti-seismic object side, and a disk-shaped rotary inertia 27 is attached to the main body 28a.
3. It is vertically rotatably supported via a bearing 34. A slide case 24 is inserted into the guide portion 28b in a fitted state, and the slide case 24 is slidably supported by the guide portion 28b.

The pin joint 29 is fixed to an end of the main body 28a on the anti-seismic object side, and is attached to a pair of mounting brackets 35 protruding from the upper part of the fixed-side support base 30.
6 and supports the horizontally arranged fixed side case 28 so as to be rotatable in the horizontal direction.

As shown in FIG. 4, the small-stroke seismic isolation device 21 having the above-described configuration is installed so that the slide case 24 and the fixed-side case 28 are arranged along the X direction. Is relatively moved in the X direction with respect to the support structure B, the relative movement of the slide case 24 and the ball nut 23 in the axial direction rotates the ball screw 26 on the fixed side, and the rotational inertia 27 integrated with the ball screw 26 rotates. Due to the rotation of the rotary inertia 27, a displacement suppressing effect is obtained.
Since the seismic isolation target A vibrates in substantially the same phase as the support structure B, a greater seismic isolation effect can be obtained with the same relative displacement compared to the conventional seismic isolation device using a damper, and conversely, the same seismic isolation effect can be obtained. The stroke to obtain can be small.

When the seismic isolation object A moves relative to the support structure B in the Y direction, the slide case 24 and the fixed side case 28 tilt about the vertical pins 32 and 36, respectively, so that the slide case 24 and the fixed side Since the cases 28 extend slightly relative to each other, destruction or damage of the device due to relative movement in the Y direction can be prevented. Further, since the rotational inertia 27 hardly rotates, the seismic isolation effect in the Y direction is not obtained, and the seismic isolation effect is obtained only in the X direction.

Next, the above-described small-stroke seismic isolation devices 1, 2
FIG. 5 shows an example in which No. 1 is applied to a base-isolated floor. The seismic isolation floor A is supported by a rolling bearing or a sliding bearing C installed on a slab B of the building, and, if necessary, a spring element or a damper that suppresses the displacement of the seismic isolation floor and provides a home return function. The base isolation floor A and the slab B are connected by an element (not shown). With respect to such a seismic isolation floor A, the small-stroke seismic isolation devices 1 and 21 all operate only in one horizontal direction, so that a plurality of small-stroke seismic isolation devices 1 and 21 are operated in two horizontal directions. They are arranged in two orthogonal directions. After the rotary inertia portions of the small stroke seismic isolation devices 1 and 21 are installed and fixed on the slab B, the mounting is completed only by connecting the tip of the slide member to the lower surface of the seismic isolation floor via a pin joint.

The rack type and the ball screw type each have the following advantages. That is, since the rack type small-stroke seismic isolation device 1 has a structure in which the rotation axis of the rotary inertia 5 is vertical and the rotary inertia 5 rotates horizontally, there is an advantage that a narrow space below the seismic isolation target can be effectively used. It is also easy to increase the magnitude (diameter) of the rotational inertia.

The ball screw type small-stroke seismic isolation device 21 is configured such that the rotary inertia mechanism is housed in a case, so that the device can be easily transported. Further, in order to obtain a large equivalent inertial mass with a predetermined rotational inertia, the diameter of the gear 12 should be reduced in the case of the rack type, and the lead angle of the ball screw 26 should be reduced in the case of the pole screw type. Then, it will correspond. In this case, comparing the two, when considering the strength aspect,
It is considered that the ball screw type can obtain a larger equivalent inertial mass than the rack type.

Although the rack type and ball screw type rotary inertia adding devices have been described above, the present invention is not limited to this, and the relative displacement between the seismic isolation target and the support structure is converted into rotary inertia rotary motion. Any mechanism may be used. In addition, the seismic isolation floor and the like have been described, but it is needless to say that the invention can be applied to the seismic isolation of a building.

[0033]

The present invention is provided independently between the seismic isolation target and the support structure, and performs relative inertial displacement of the seismic isolation target and the support structure in a specific direction via a slide member. Since the rotary inertia adding device for converting into rotary motion is mounted on each of the seismic isolation target and the support structure so as to be horizontally rotatable with a pin, a bear rig, or the like, the following effects are obtained. (1) Since the rotary inertia adding device can be an independent device including a slide member that moves in the axial direction and a rotary inertia that is rotated by the slide member, the slide member and the rotary inertia are mounted so as to be horizontally rotatable. By doing
A force other than the seismic isolation direction of the device can be absorbed, the device can have a simple structure, and the manufacturing cost of the small-stroke seismic isolation device can be greatly reduced. (2) The rotational inertia of the rotational inertia adding device is installed and fixed on the support structure, and the end of the slide member may be fixed to the seismic isolation target with a pin. Since the independent rotary inertia adding devices may be installed in parallel with the respective directions, the installation can be easily performed, and the construction cost can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a rack type of a small-stroke seismic isolation device of the present invention, wherein (a) is a plan view, (b) is an elevation view, and (c) is a cross-sectional view.

FIG. 2 is a plan view showing an operation state of the rack type small stroke seismic isolation device of the present invention.

FIGS. 3A and 3B are a ball screw type of the small-stroke seismic isolation device of the present invention, wherein FIG. 3A is an elevation view and FIG.

FIG. 4 is a plan view showing an operation state of the ball screw type small stroke seismic isolation device of the present invention.

FIG. 5 is a plan view showing an example in which the small-stroke seismic isolation device of the present invention is applied to a seismic isolation floor, where (a) is a rack type and (b)
Is a ball screw type.

[Explanation of symbols]

 A: Seismic isolation target (separation floor, etc.) B: Supporting structure (slab of building, etc.) C: Rolling or sliding bearing 1. Small stroke seismic isolation device 2. Rotary inertia adding device (rack) Type) 3 ... Slide rod 4 ... Pin joint 5 ... Rotating inertia 6 ... Shaft 7 ... Bearing 8 ... Rack 9 ... Linear guide 9a ... Guide rail 9b ... Slider 10 ... Mounting bracket 11 ... Vertical Pin 12 ... Gear 13 ... Guide 14 ... Bearing 21 ... Small stroke seismic isolation device 22 ... Rotation inertia adding device (ball screw type) 23 ... Ball nut 24 ... Slide case 25 ... Pin joint 26 ... ... Ball screw 27 ... Rotational inertia 28 ... Fixed side case 28a ... Main body 28b ... Guide part 29 ... Pin joint 30 ... ... fixed side support Mount 31 ...... mounting bracket 32 ...... vertical pin 33 ...... horizontal support shaft 34 ...... bearing 35 ...... mounting bracket 36 ...... vertical pin

Claims (3)

[Claims] An object is provided independently between a seismic isolation target and a support structure, and a relative displacement in a specific direction between the seismic isolation target and the support structure is converted into a rotational motion of a rotary inertia through a linear motion member. A small-stroke seismic isolation device characterized in that a rotary inertia adding device to be converted is attached to each of a seismic isolation target and a support structure so as to be horizontally rotatable. 2. A rotary inertia adding device, comprising: a slide member having a rack on a side surface, a base end of which is mounted on a seismic isolation target so as to be horizontally rotatable by a pin, and a gear meshing with the rack. The small-stroke seismic isolation device according to claim 1, further comprising a rotary inertia supported on the body so as to be horizontally rotatable. 3. A rotary inertia adding apparatus, comprising: a slide member having a ball nut at a distal end and a base end rotatably mounted on a seismic isolation target by a pin so as to be horizontally rotatable; and a ball screw screwed into the ball nut. 2. The small stroke according to claim 1, further comprising: a rotary inertia having the rotary inertia, and a fixing member rotatably supporting the rotary inertia and fixed to a support base on the support structure so as to be horizontally rotatable by a pin. Seismic isolation device.