JP2003269529A - Base isolation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a base isolation device equipped with a base isolated floor movably supported on a substrate via a plurality of bearing units, and a plurality of spring damper units for damping vibration of the base isolated floor and returning to an original point. <P>SOLUTION: Two spring damper units 40 are arranged perpendicular to each other in an upward and downward direction between a lower plate 11 on the substrate side and an upper plate 12 on the base isolated floor side. A bearing unit 14 has an upper ball 17 and a lower ball 16 rotatably installed to a main body 15. The upper ball 17 movably supports the base isolated floor side, and the lower ball 16 supports the bearing unit 14 movably against the substrate side. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device for protecting relatively small and expensive articles such as small precision equipment and antique arts from earthquakes, and more particularly to a small seismic isolation device which can be installed in a small area.

[0002]

2. Description of the Related Art When displaying and storing relatively small and expensive items such as small precision instruments and antique art, the items move or fall due to horizontal shaking or vibration due to earthquake or traffic vibration. Therefore, it is necessary to take sufficient protection measures so as not to be damaged. Therefore, measures have been taken to place such expensive items on a large seismic isolation device for display and storage. A commonly used seismic isolation device includes a base isolation floor movably supported on a base via a plurality of bearing units, and a plurality of spring damper units for damping vibrations of the base isolation floor and returning to the origin.

FIG. 4A is a front view of a conventional typical seismic isolation device, and FIG. 4B is a view of the seismic isolation device taken along the line BB in FIG. 4A. The seismic isolation device 1 includes four bearing units 3 arranged on the lower surface of the seismic isolation floor main body 2, a plurality of balls 4 rotatably accommodated in the bottom of each bearing unit 3, and a ball receiving plate that supports each ball 4. It is equipped with 5. Each ball receiving plate 5 has a base 2a having a horizontal mounting surface.
The seismic isolation floor (not shown) on which the article is placed is fixed to the upper plate of each bearing unit 3.

Further, the seismic isolation apparatus 1 is provided with a plurality of spring damper units 6 for damping the vibration of the seismic isolation floor and returning to the origin. Spring damper unit 6 is X
Two units facing each other at a predetermined interval for the direction and two units facing each other at a predetermined interval for the Y direction are provided, and a total of four units are provided, which are a fixed portion 2b fixed to the base 2a and a base isolation floor body 2. It has the support part 2c protrudingly provided by the lower surface.
Both ends of the spring 6a are connected to the support portion 2c and the fixed portion 2b.
The spring 6a is fixed to the spring damper unit 6 and serves to perform the damper action and the origin return action of the spring damper unit 6.

When a horizontal vibration or shake is applied to the seismic isolation device 1 due to an earthquake or the like, the seismic isolation floor will be attached to each bearing unit 3
It is supported and moved by the spring damper unit 6
The damper action reduces the moving speed and suppresses the moving distance. Then, as the vibrations and shakes subside, the seismic isolation floor is gradually returned to the origin (home position) by the origin returning action of the spring damper unit 6.

[0006]

However, since the conventional seismic isolation device 1 uses four spring damper units 6 and four ball bearing units 3, respectively, the weight and size of the device are increased and the cost is increased, resulting in maintenance. There was a problem that it took time and effort.

Further, the conventional seismic isolation device 1 requires the ball bearing plate 5 having an area with a little margin in the permissible movement range of the seismic isolation floor. The conventional ball receiving plate 5 is made of a steel plate having extremely high surface hardness and smoothness (for example, center line average roughness of 1.6a) and adjusted to a small strain (for example, 1/1000 to 1/500). Has been done. In order to manufacture the ball receiving plate 5, for example, a steel plate having an appropriate thickness is first cut into a predetermined size and then quenched to increase its hardness.
Next, in order to remove the distortion and fine irregularities on the surface, machining such as milling is performed to cut out the surface. Since machining is performed after the hardness is increased in this way, it takes time and tool consumption becomes large. Therefore, there is a problem that the cost is high to manufacture a ball bearing plate having a relatively large area.

Therefore, the present invention has an object to solve such a problem of the conventional seismic isolation device, and a first object thereof is to halve the number of the spring damper units 6 in the seismic isolation device. A second object is to reduce the area of the ball receiving plate in the seismic isolation device.

[0009]

[Means for Solving the Problems] That is, a first invention for solving the above-mentioned problems is to provide a base isolation floor movably supported on a base through a plurality of bearing units, vibration damping of the base isolation floor, and return to origin. In a seismic isolation device including a plurality of spring damper units for performing the above, two spring damper units are provided, and they are arranged vertically with respect to each other (claim 1).

A second invention for solving the above problems is
In a seismic isolation device including a base-isolated floor movably supported on a substrate through a plurality of bearing units and a plurality of spring damper units for damping vibration of the base-isolated floor and returning to the origin, the bearing unit is a main body. It has an upper ball and a lower ball that are rotatably provided in the upper ball, the upper ball movably supports the base isolation floor side, and the lower ball movably supports the bearing unit with respect to the base side. (Claim 2).

In the second aspect of the invention, the bearing units can be connected to each other by a connecting body (claim 3).

When the bearing units are connected to each other by a connecting body, an origin returning mechanism for returning the bearing units to the origin can be further provided (claim 4).

In any one of the second aspect of the present invention, the surfaces for receiving the upper ball and the lower ball can be made of a high hardness non-ferrous material (claim 5).

Further, in any of the above-mentioned second inventions, the spring damper unit is provided in the same manner as in the first invention.
Units may be provided and they may be arranged vertically with respect to each other (claim 6).

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view showing the seismic isolation device according to the present invention in an exploded manner, and FIG. 2 is an exploded perspective schematic view of the spring damper unit, the floor side frame, and the base side frame. In the figure, 10 is a seismic isolation device, 11 is a lower plate, 12 is an upper plate, 13 is a ball receiving plate, 14
Is a bearing unit and 40 is a spring damper unit.

The lower plate 11 and the upper plate 12 are manufactured by processing a highly rigid material such as a steel plate into a square shape. The lower plate 11 is fixed directly on the base 20 (FIG. 3) of the seismic isolation device 10 or via a suitable pedestal,
Four disc-shaped ball receiving plates 13 are fixed to the upper surface of the lower plate 11 at predetermined intervals by adhesion or the like. The upper plate 12 is fixed to the lower side of the seismic isolation floor on which articles to be seismically isolated are placed, and four disk-shaped ball receiving plates 13 are also adhered to the lower surface of the upper plate 12 at predetermined intervals. Fixed.
The lower plate 11 can also serve as a base, and the upper plate 12 can also serve as a base isolation floor.

4 between the lower plate 11 and the upper plate 12
One bearing unit 14 is arranged at a predetermined interval.
Each bearing unit 14 is a cylindrical main body 1 having steps.
5, a plurality of (three in this example) lower balls 16 rotatably held on the lower side of the main body 15, and an upper ball 17 rotatably held on the upper side of the main body 15. ing. Then, with the lower ball 16 in contact with the surface of the ball receiving plate 13 of the lower plate 11, the upper plate 12 is lowered as indicated by the arrow, so that the upper ball 17 contacts the surface of the ball receiving plate 13 of the upper plate 12.

The ball receiving plate 13 can be made by processing a steel plate as in the conventional seismic isolation device. However, the conventional method of processing from a thick steel plate requires much labor and cost, so it is desirable to use a high hardness non-ferrous material such as glass or ceramics. For example, glass having extremely high smoothness and small distortion can be easily and inexpensively obtained.

The material itself of glass is hard and easy to process. However, since the bending stress is lower than that of a steel sheet, it is desirable to bond a normal mild steel sheet that has not been tempered to glass to form a multi-layer structure in order to improve it. For example, the surface of the bearing unit 14 in contact with the ball is a glass surface,
Elastic layer of appropriate thickness on the back (adhesive or double-sided tape)
The mild steel plates are laminated with the sheet sandwiched therebetween. Further, ceramics having properties similar to glass can be easily obtained.

The bearing units 14 are arranged at the four corners of a square, and the bearing units 14 are connected to each other by elongated connecting members 18 such as round steel as shown in the drawing. As a result, when horizontal vibration or shaking is applied to the seismic isolation device 10, each bearing unit 14 is connected to the connecting body 1.
Since they are connected to each other at 8 and move synchronously, the mutual intervals are always constant. It should be noted that it is practically sufficient to return each bearing unit 14 to the vicinity of the origin (home position) when the vibrations and shakes have subsided, but it is desirable to completely return the bearing unit 14 to the origin from the viewpoint of balance. In that case, an origin return mechanism described later is provided.

Y crosses the center of the upper surface of the lower plate 11.
A spring damper unit 40 elongated in the direction is arranged. Further, an elongated spring damper unit 40 is arranged in the X direction across the center of the lower surface of the upper plate 12. Each spring damper unit 40 of this example
The pair of independent sliders 26 are connected to each other by the pair of springs 29 and the oil damper 41 so that the sliders 26 can be expanded and contracted. This spring 29 is of a tension type. And each slider 26
A pair of rotating rollers 25 are arranged at the corners of one of the planes, and the base side frame 11a or the floor side frame 12a is arranged between the rotating rollers 25 of both sliders 26, and the respective frames 11a, 12a and the rotating roller 25 are arranged. Can be attached and detached. Further, four guide rollers 28a are arranged at the four corners of the other surface of both sliders 26, and they are guided by a pair of guide rails 27 fixed to the plates 11 and 12. A stopper 30 is arranged at the center of the guide rail 27.

When horizontal vibration or shaking is applied to the seismic isolation device 10, the moving part of the spring damper unit 40 moves while receiving the damping force of the oil damper 41. Therefore, if horizontal vibration or shaking is applied to the seismic isolation device 10,
The damper action of the spring damper unit 40 reduces the moving speed of the base-isolated floor and reduces the moving distance thereof. The seismic isolation floor is gradually returned to the origin (home position) by the return-to-origin action of the spring damper unit 40 as the vibration and shaking are stopped.

The spring damper unit 40 fixed to the lower plate 11 and the spring damper unit 40 attached to the upper plate 12 are arranged such that their longitudinal directions are orthogonal to each other and overlap in the vertical direction of the seismic isolation device 10. Then, in this example, the spring damper unit 40 of the lower plate 11 copes with the vibration and shake of the seismic isolation device 10 in the Y direction, and the spring damper unit 40 of the upper plate 12 resists the vibration and shake of the seismic isolation device 10 in the X direction. deal with.

Next, on the lower surface of the upper plate 12, both leg ends 12b of a gate-shaped floor side frame 12a are positioned in the X direction and fixed on the back, and the lower plate 11 is fixed to the gate-shaped base side frame 11a. Both leg ends 11b are positioned in the Y direction and fixed on the back. A spring stopper 23 is guided on each of the frames 11a and 12a so as to be movable in the longitudinal direction of each frame. The spring stopper 23 is provided with a connecting member 18 for connecting the bearing units 14 to each other.
Is loosely inserted, and both ends of the spring 24 are fixed to the spring stopper 23 and the ball bearing unit 14. At the same time, the spring 24 is fitted on the connecting body 18.

Then, the seismic isolation device 10 is arranged on the base 20 of the building (FIG. 3). The lower plate 11 is fixed to the base 20, and the ball receiving plate 13 is arranged on the lower plate 11. A stopper frame 22 (FIG. 3) having a short height can be provided on the peripheral edge of the ball receiving plate 13.

Next, the seismic isolation function of the seismic isolation device 10 will be described. First, an article intended for seismic isolation is placed on the seismic isolation floor. In that state, seismic isolation device 1 due to, for example, an earthquake
When horizontal vibration or shaking in the Y direction is applied to 0, the base 20 (or the lower plate 11) and each bearing unit 14 reciprocate in the Y direction relative to the upper plate 12 in FIG. Occurs. This reciprocating movement is suppressed by the damping action and the restoring action of the spring damper unit 40 attached to the lower plate 11, and when the horizontal vibration or shaking is subsided, it is gradually attenuated and returns to the origin.

On the other hand, when a horizontal vibration or shake in the X direction is applied to the seismic isolation device 10, the base 20 (or the lower plate 1)
1) Upper bearing units 14 and upper plate 1
Reciprocating movement in the X direction occurs in each of the two. This reciprocating movement is suppressed by the damping action and the restoring action of the spring damper unit 40 fixed to the upper plate 12, and when the horizontal vibration or shake is subsided, it is gradually attenuated and returns to the origin. When vibration or shaking in the XY intermediate direction is applied to the seismic isolation device 10, the damping action and the returning action of each spring damper unit 40 act on the force that decomposes them in the X and Y directions.

As described above, even if the seismic isolation device 10 is vibrated or shaken in any of XY directions, each bearing unit 1
4 and the upper plate 12 return to the origin gradually while repeating the reciprocating movement at the suppressed speed and movement amount. Since the moving amount of the moving part of the seismic isolation device 10 is shared by the bearing unit 14 and the upper plate 12 substantially equally, the moving amount of the bearing unit 14 can be almost halved as compared with the conventional seismic isolation device. Therefore, since the area of each ball receiving plate 13 in contact with the balls of the bearing unit 14 can be reduced, the processing thereof becomes simple.

The bearing units 14 move in synchronization with each other by the connecting body 18. Finally, the origin return mechanism 50 returns to the origin. That is, when the horizontal vibrations and shakes subside, if the bearing units 14 that reciprocally move synchronously do not completely return to the origin and a position shift occurs, the pair of springs 24 that constitute the origin returning mechanism 50. A stress proportional to the positional deviation remains in the. Therefore, each spring 24 moves each bearing unit 14 in the direction in which the residual stress is released, that is, in the origin direction. The origin return mechanism 50 moves the spring stopper 23 so as not to impede the moving action of the connecting body 18 in response to horizontal vibration or shaking due to an earthquake or the like, and the spring 24 moves the spring stopper 23. Is provided for returning the to the original position.

[0030]

As described above, the first invention according to the present invention is characterized in that two spring damper units are provided and they are vertically arranged so as to be orthogonal to each other. Therefore, the spring damper unit can be halved as compared with the conventional seismic isolation device, and the size of the entire device can be correspondingly reduced.

According to a second aspect of the present invention, the bearing unit has an upper ball and a lower ball rotatably provided on the main body, the upper ball movably supporting the seismic isolated floor side, and The side balls support the bearing unit movably with respect to the base side. Therefore, the amount of movement of the bearing unit can be reduced while keeping the relative movement of the seismic isolation floor. Furthermore, one of the ball receiving plates
Since the area per sheet can be reduced, its processing and the like are also simplified.

In the second aspect of the invention, the bearing units can be connected to each other by a connecting body. By providing such a connecting body, each bearing unit can be moved completely synchronously.

When the bearing units are connected to each other by a connecting body, an origin returning mechanism for returning the bearing units to the origin can be further provided.
By providing such an origin returning mechanism, each bearing unit can be completely returned to the origin.

In any of the above-mentioned second inventions, the surface of the ball receiving plate for receiving the upper ball and the lower ball can be made of a high hardness non-ferrous material. By using such a non-ferrous material, the ball receiving plate can be easily processed and the cost is reduced.

Further, in any one of the above-mentioned second invention, two units of the spring damper unit are provided,
They can be placed one above the other, orthogonal to each other. With this configuration, the spring damper unit can be halved compared to the conventional seismic isolation device, and the relative movement of the seismic isolation floor can be maintained while reducing the amount of movement of the bearing unit. Since the area of each receiving plate can be reduced, its processing is also simplified. Further, the size of the seismic isolation device can be reduced to about 1/7 of that of the conventional device.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an exploded seismic isolation device according to the present invention.

FIG. 2 is a schematic exploded perspective view of a spring damper unit, a floor side frame, and a base side frame of the device.

FIG. 3 is a front view showing an example of an origin returning mechanism.

FIG. 4 is a front view and a rear view of a typical conventional seismic isolation device.

[Explanation of symbols] 1 seismic isolation device 2 seismic isolation floor body 2a foundation 2b fixed part 2c support 3 bearing units Four balls 5 ball support plate 6 Spring damper unit 6a spring 10 seismic isolation device 11 Lower plate 11a Base side frame 11b Leg end 12 Upper plate 12a Floor side frame 12b Leg end 13 Ball support plate 14 Bearing unit 15 body 16 lower ball 17 Upper ball 18 connected body 20 foundation 22 Stopper frame 23 Spring stopper 24 spring 25 rotating rollers 26 Slider 27 Guy Trail 28a Guide roller 29 spring 30 stopper 40 Spring damper unit 41 oil damper 50 Home return mechanism

Claims (6)

[Claims] 1. A base-isolated floor movably supported on a base via a plurality of bearing units, and a plurality of spring damper units 4 for damping vibrations of the base-isolated floor and returning to the origin.
In the seismic isolation device having 0, the seismic isolation device is characterized in that two spring damper units 40 are provided, and they are arranged vertically with respect to each other. 2. A base-isolated floor movably supported on a base via a plurality of bearing units, and a plurality of spring damper units 4 for damping vibration of the base-isolated floor and returning to the origin.
In the seismic isolation device with 0, the bearing unit 14 has an upper ball 17 and a lower ball 16 rotatably provided in the main body 15, and the upper ball 17 movably supports the seismic isolation floor side, A seismic isolation device characterized in that the lower ball (16) supports the bearing unit (14) movably with respect to the base side. 3. The seismic isolation device according to claim 2, wherein the bearing units 14 are connected to each other by a connecting member 18. 4. The seismic isolation device according to claim 3, further comprising an origin returning mechanism 50 for returning the bearing units 14 to the origin. 5. The method according to any one of claims 2 to 4,
A seismic isolation device characterized in that the surfaces for receiving the upper ball 17 and the lower ball 16 are formed of a high hardness non-ferrous material. 6. The method according to any one of claims 2 to 5,
Two units of the spring damper unit 40 are provided,
A seismic isolation device characterized by arranging them vertically with respect to each other.