JPH11107504A - Base-isolation floor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a natural period of a floor within an approximately fixed range regardless of the fluctuation in the floor load by using a coil spring having such a nonlinear characteristic that the spring constant is gradually and continuously strengthened for a base isolator. SOLUTION: A base isolator provided with a coil spring 16 which has such a nonlinear characteristic that the spring constant is gradually and continuously strengthened with the fluctuation in the floor load F is arranged between a floor 12 and a slab 14 in such a state as freely displaced in the vertical direction. The load of equipment on the floors 12, 12 is inputted in a spring sheet 21 via a connecting plate 25, an upper fitting plate 20, and an adjustment bolt 26. When the floor load F is relatively small, the approximately whole length of the coil spring 16 supports the load, a smaller-pitch part is gradually crushed and closely stuck with the increase in the floor load F, and a larger-pitch part exhibits a displacement absorbing function. As a result, the natural period of the floor can be held within an approximately fixed range despite of the fluctuation in the load. The fluctuation of the floor in inputting vibration can be smoothly controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-isolating floor apparatus in which a floor is elastically supported by a slab below the floor, and a vertical vibration input from the slab to the floor is isolated.

[0002]

2. Description of the Related Art In a room where precision equipment such as computer equipment and measurement control equipment is installed, it is desirable that the floor on which such equipment is installed be a vibration-isolating floor capable of blocking (vibrating) external vertical vibrations. As such a vibration isolating floor device, a floor supporting frame is vertically displaceable with respect to a slab serving as a supporting base below the floor, and the supporting frame is slab-moved through a number of vibration isolating units using coil springs. There is a structure having an elastic support on the top.

[0003] In such a vibration isolating floor device, the natural period of the floor is determined by the spring constant of the coil spring and the floor load. Regardless of the specific period of the floor, the spring constant is determined to be constant according to the floor load including the weight of the equipment installed on the floor, etc. The value is suitable for In addition, a level adjustment bolt is interposed between the support frame and the vibration isolation unit to adjust the floor surface to a predetermined height by absorbing the displacement of the coil spring that contracts in accordance with the floor load.

[0004]

However, in the above-mentioned conventional vibration isolating floor device, the coil spring of the vibration isolating unit has:
Since the spring constant is used with a constant linear characteristic, if the floor load fluctuates due to replacement or expansion of equipment installed indoors or layout change, the natural period of the floor will also be It changes with it. For this reason, after such a floor load fluctuation, the natural period of the floor suitable for the vibration isolation cannot be maintained, and the vibration isolation function is significantly reduced.
Therefore, in such a case, it is necessary to replace the vibration isolating unit with a spring constant suitable for the floor load after the change, and there is a problem that an extremely large-scale operation is required.

In order to more effectively isolate the floor elastically supported by the vibration isolation unit from external vibrations such as earthquakes,
It is desirable to increase the natural period T determined by the floor load and the rigidity of the coil spring of the vibration isolation unit to about 1.2 seconds. For this purpose, the rigidity (spring constant) of the coil spring is required.
Must be set low.

However, when the rigidity of the coil spring is reduced, the amount of contraction (displacement) of the spring due to the floor load increases,
In addition, the expansion and contraction stroke of the coil spring must be secured so that external vibrations such as earthquakes can be further effectively absorbed in the state of large displacement. Then, the length of the coil spring is inevitably long. Therefore, the clearance between the floor on which the coil springs are placed and the slab must be set large, and the floor height will be increased by that amount if the vibration isolation floor is installed with a longer period. However, there has been a problem that the height of the entire building becomes unnecessarily large. In other words, in other words, it is difficult to install a conventional anti-vibration floor in an existing building where the floor height is not enough to increase the period.

On the other hand, it is conceivable to employ an air spring as a spring that can easily increase the period. However, in order to construct a vibration isolating floor device by incorporating an air spring, a control panel, various air devices, piping, auxiliary A large number of peripheral devices and parts such as tanks are required, which increases the cost of the apparatus, and also increases running costs due to periodic maintenance and replacement of parts.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to maintain the natural period of a floor within a substantially constant range regardless of the magnitude of the floor load. An object of the present invention is to provide a vibration-isolating floor device capable of increasing the natural period without increasing the clearance between the slab and the slab.

[0009]

In order to achieve the above object, a vibration isolating floor device according to the present invention arranges a floor so as to be vertically displaceable with respect to a slab below the floor, and places a floor between the floor and the slab. In a vibration isolating floor device that is configured to isolate vibration transmitted from the slab side to the floor by an interposed coil spring,
The coil spring is characterized by using a spring having a non-linear spring characteristic in which a spring constant continuously increases with an increase in floor load.

[0010] The operation of the vibration isolating floor device of the present invention with the above configuration will be described. A spring having a non-linear characteristic in which a spring constant continuously increases with an increase in floor load is used as a coil spring. Load / spring constant] can be set so that the natural period of the floor, which is proportional to the square root of the load, is kept substantially constant irrespective of the fluctuation of the floor load. Good holding can be achieved regardless of fluctuations. Further, since the spring constant when the floor load is large is large, the amount of shrinkage under the large load is small, and the overall length of the coil spring can be formed as short as possible to suppress the height of the vibration isolating floor device. This makes it easy to increase the natural period of the floor.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 4 show an embodiment of a vibration-isolating floor device according to the present invention. FIG. 1 is a sectional view of the vibration-isolating floor device. FIG. 2 is an enlarged sectional view showing a coil spring used in the vibration-isolating floor device. 3 is a characteristic diagram showing the relationship between the amount of deformation of the coil spring and the load fluctuation, and FIG. 4 is a characteristic diagram showing the relationship between the floor load and the natural period of the floor.

As shown in FIG. 1, in the vibration-isolating floor device of the present embodiment, a floor 12 is disposed so as to be vertically displaceable with respect to a slab 14 which is a support base below the floor 12, and the floor 12 and the slab 14
And a coil spring 16 provided in the vibration isolating unit 10 to support the floor load and to isolate vibration transmitted from the slab 14 to the floor 12. It is supposed to.

Here, as a basic configuration of the vibration isolating unit 10 in the present embodiment, a spring having a non-linear characteristic in which a spring constant K with respect to a change in a floor load F gradually and continuously increases is used as the coil spring 16. Like that.

The vibration isolation unit 10 includes a base plate 18 provided on the slab 14 and an upper mounting plate 20 provided on the floor 12 side.
The coil spring 16 is provided between the upper mounting plate 20 and the upper mounting plate 20. A guide support 22 is provided upright from the center of the base plate 18. The coil spring 16 is disposed around the guide support 22, and the center of the upper mounting plate 20 slides on the guide support 22. It is freely inserted.

On the upper end of the coil spring 16, a spring seat 21 having a guide portion 21a inserted through the guide post 22 is attached. The base plate 18 and the upper mounting plate 20 have coil springs 16 respectively.
Cylindrical portions 18a and 20a are provided to cover the outer peripheral side of.

On the upper surface of the upper mounting plate 20, a rectangular connecting plate 25 extending in the left-right direction in the figure is integrally welded and erected, and this connecting plate 25 avoids the guide column 22 and Are arranged side by side on both sides in the direction perpendicular to the plane of the drawing. In addition, these connecting plates 2
A frame connecting member 24 made of an L-shaped plate member extending downward from the side is integrally joined to each of the left and right sides of each of the right and left sides by bolts. The lower end of the frame connecting member 24 is horizontally arranged. Is integrally welded to one end of an S-shaped frame 28. That is, each of the frames 28, 28 arranged on the left and right sides of the vibration isolation unit 10
Are connected to the upper mounting plate 20 of the vibration isolating unit 10 via a frame connecting member 24 and a connecting plate 25, respectively, and both frames 28, 28 are connected by the frame connecting members 24, 24 and the connecting plate 25. , Coil spring 16
Are connected to each other so as to straddle the upper half in a U-shape. The other end of each of the frames 28 is similarly connected to an adjacent vibration isolating unit (not shown) via a frame connecting member or the like, and both ends are supported by the vibration isolating unit 10 and horizontally arranged. Has become.

The upper mounting plate 20 is provided with a level adjusting bolt 26 which is screwed with the upper mounting plate 20, and the tip of the level adjusting bolt 26 penetrates through the upper mounting plate 20, and the coil spring 1
6 is in contact with the spring seat 21 at the upper end.

The floor member 13 is supported on the upper side of the frame 28 via support legs 30. The floor member 13 includes the floor member 13, the support legs 30, the frame 28, the frame connecting member 24 and the like. The load on the vibration isolator 1 and the loads on the equipment and the like placed on the floor 12 are transmitted via the connecting plate 25, the upper mounting plate 20, and the level adjusting bolt 26.
0 is input to the spring seat 21. The floor member 13 located above the guide column 22 is provided with a notched inspection port 13a having a predetermined area, and the inspection port 13a is removably closed by a lid 13b.

The coil spring 16 has a SUP
9, SUP 9A or the like, and the pitch P is changed so as to gradually increase from one end to the other end as shown in FIG. That is, when the material, the spring winding diameter and the wire diameter are the same, the spring constant K of the coil spring 16 is smaller as the number of effective turns as the spring is larger, and is smaller as the number of turns is smaller. Since the effective number of turns as a spring is gradually reduced by being in close contact with the small portions, the spring constant K of the coil spring 16 is designed to gradually increase from one end of the small pitch P to the other end of the large pitch P.

With the above configuration, in the vibration isolating floor device 10 of this embodiment, a spring having a non-linear characteristic in which the pitch P gradually and continuously increases from one side to the other side is used as the coil spring 16. Therefore, when the floor load F is relatively small and the amount of contraction (deformation) of the coil spring 16 is small, the coil spring 16 supports the load over substantially the entire length and exhibits a function of absorbing displacement. A small spring constant K obtained over the whole 16 works.

On the other hand, when the floor load F increases, the amount of contraction of the coil spring 16 increases. In this case, the coil spring 16 gradually collapses at a small pitch P in accordance with the load. The portions having a large pitch P, which have a large spring constant and have not yet been brought into close contact with each other, exhibit a displacement absorbing function.

FIG. 3 shows the relationship between the variation of the floor load F and the amount of contraction (deformation) of the coil spring 16, and shows the spring characteristic X of the coil spring 16. That is, the vertical axis is the floor load,
The horizontal axis indicates a change in height of the coil spring 16 when the floor load F is increased based on the point O. As shown in the drawing, the spring characteristic of the coil spring 16 is a curve graph in which the slope (spring constant K) continuously increases with displacement. That is, in the spring characteristic X, the smaller the floor load F is, the larger the amount of shrinkage with respect to the load increase is, and the larger the floor load F is, the smaller the amount of shrinkage with respect to the load increase is.

The natural period T of the floor 12 can be obtained by the following equation 1 as generally known. In the equation, W is a load, K is a spring constant, and g is a gravitational acceleration. [Formula 1] T = 2π (W / K · g) ^1/2

That is, as shown in Equation 1, the natural period T
And the floor load F, such that the natural period T is proportional to the square root of [load / spring constant]. Here, in the present embodiment, as shown in FIG. 3, the spring constant K continuously increases as the floor load F increases, so that the natural period T can be set to be substantially constant. The characteristic period T at this time is a characteristic diagram as shown in FIG. That is, the point o corresponding to the initial value O point shown in FIG. 3 is plotted in the periodic characteristic Y shown in this characteristic diagram, and the periodic characteristic Y increases smoothly as the floor load F increases. Accordingly, the spring constant K of the coil spring 16 is set in the relationship between the load and the height shown in FIG. By doing so, the natural period T in the normal use area R can be set within a range of about 1.2 seconds.

As described above, the natural period T of the floor 12 can be lengthened to a range of about 1.2 seconds irrespective of the fluctuation of the floor load F, so that a remarkable vibration isolation effect against an external vibration such as an earthquake can be obtained. Can be demonstrated.

Here, if the floor load F is changed due to an increase or relocation of the mounted equipment, a layout change, or the like, the amount of sinking of the floor 12 naturally changes, but the height of the floor surface is adjusted by level adjustment. Since the height can be easily reset to the predetermined value S by the bolt 26, a simple operation of simply adjusting the height by operating the level adjustment bolt 26 is sufficient, and a large-scale operation such as replacement of the coil spring 16 can be performed. No need to do.

Since the spring constant K of the coil spring 16 increases as the load increases, the spring length of the coil spring 16 should be made as short as possible as compared with the conventional linear spring. And therefore the vibration isolation unit 10
Can be reduced, and the distance S between the floor 12 and the slab 14 can be reduced to prevent the building from becoming unnecessarily high. In other words, it means that it is possible to install a vibration-isolating floor device having a longer period even in an existing building having a small floor height.

In this embodiment, the coil spring 16
Discloses a case in which the pitch P is gradually changed, but the winding diameter of the coil is not limited to this, and a spring material having a gradually increasing wire diameter may be used. A similar function can be obtained.

[0029]

As described above, in the vibration isolating floor device according to the first aspect of the present invention, the coil spring of the vibration isolating unit has a non-linear characteristic in which the spring constant with increasing floor load increases gradually and continuously. Is used, the natural period of the floor, which is proportional to the square root of [load / spring constant], can be maintained within a substantially constant range regardless of the fluctuation of the floor load.
Therefore, even if the floor load fluctuates due to replacement or expansion of equipment installed in the room, or a layout change, it is possible to maintain a good vibration isolation effect against external vibrations such as earthquakes. There is no need to replace coil springs.

Further, since the floor load can be supported with a large spring constant as the amount of contraction of the coil spring increases, the overall length of the coil spring can be made as short as possible, and therefore the vibration isolating floor device can be formed. Existing building, where the height of the floor can be made low, the space between the floor and the slab can be reduced and the building can be prevented from becoming unnecessarily high, Therefore, it is possible to install a vibration isolating floor device having a longer period.

Further, since the change in the spring constant of the coil spring with respect to the change in the floor load is smooth, and the natural period also changes smoothly, an excellent effect that the swing of the floor during vibration input can be suppressed smoothly. To play.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a vibration isolation floor device according to the present invention.

FIG. 2 is an enlarged view showing one embodiment of a non-linear coil spring used in the vibration isolating floor device of the present invention.

FIG. 3 is a characteristic diagram illustrating a relationship between a deformation amount and a load variation of a non-linear coil spring used in an embodiment of the vibration isolating floor device of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a floor load and a natural period of a floor in one embodiment of the vibration isolating floor device of the present invention.

[Explanation of symbols]

 10 Vibration isolation unit 12 Floor 14 Slab 16 Coil spring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yukio Okuda 2-3-3 Kandajicho, Chiyoda-ku, Tokyo Co., Ltd. Obayashi Gumi Tokyo Head Office (72) Inventor Kazuo Ebihara 2-3-3 Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office (72) Inventor Koichi Maeda 2-3-3 Kandajicho, Chiyoda-ku, Tokyo Stock Company Obayashi Tokyo Office (72) Inventor Masataka Kaneko 4-640 Shimoseito, Kiyose City, Tokyo Stock Obayashi Technical Research Institute

Claims (1)

[Claims] A floor is disposed so as to be vertically displaceable with respect to a slab below the floor, and a vibration transmitted from the slab to the floor by a coil spring interposed between the floor and the slab is isolated. In the vibration isolating floor device,
A vibration-isolating floor device using a spring having a non-linear spring characteristic in which a spring constant continuously increases with an increase in floor load.