JPH1137214A - Base isolation and vibration resistant device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation and vibration resistant device making vertical base isolation or vertical vibration isolation. SOLUTION: In this device, a spring mechanism having a negative spring constant, and a spring having a positive spring constant are combined, in more concrete, the respective end parts of a pair of links 7 are pivotally mounted on upper and lower mounts 2 and 1, and also the respective other end parts are pivotally mounted on the respective horizontal moving mechanisms 8-1 and 8-2 of the lower and upper mounts 1 and 2; and a first coil spring having plural negative spring constants is arranged on the lower mount 1, and second coil springs 4 having plural positive spring constants, and third coil springs 5 having shackles 11 are arranged between the lower and upper mounts 1 and 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical vibration damping device for vertical seismic isolation or vertical vibration isolation.

[0002]

2. Description of the Related Art As a device for reducing vertical vibration of an earthquake, an industrial machine, or the like, a compression spring, an air spring or rubber is used to support an upper load, and a natural frequency longer than the natural frequency of vertical vibration is set. Generally, the vibration is reduced by using the method described above.

As a device for reducing vertical vibration, a device for reducing transmission of vibration generated from an industrial machine or the like (vibration isolator) or a device for reducing transmission of vibration such as an earthquake to an industrial machine ( Seismic isolation and vibration isolation devices). In all cases, the load of an industrial machine or the like is generally elastically supported, and the main three types are as follows.

1) Apparatus using an air spring When an air spring is used under a structure, a soft spring constant can be obtained in order to increase the vibration reduction effect.
Ancillary equipment such as a compressor and an auxiliary tank is required, and setting for a long cycle is very expensive.

2) Apparatus using a metal spring When a metal spring is used under a structure, the design is easy and inexpensive because the material constant is stable. A deflection length is required, and it is very difficult to set a long cycle. In addition, as in the case of the vertical seismic isolation device shown in FIG. In addition, the mounting length is very long to support the load of the structure, requiring a large space.

3) Apparatus using anti-vibration rubber There is an advantage that damping due to internal friction can be obtained, but it is difficult to obtain a flexure length and a stroke for supporting the load of the apparatus when setting a long cycle. The durability is also inferior to the others.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a new long-period seismic isolation device in which the above-mentioned drawbacks of the conventional vibration damping device are improved.

[0008]

Means for Solving the Problems The present inventors combine a spring mechanism having a negative spring constant and a spring mechanism having a positive spring constant between the upper and lower mounts, and specifically combine a link mechanism and a coil spring. As a result, a new long-period seismic isolation device has been realized. That is, the invention of claim 1 is a seismic isolation device in which a mechanism having a spring having a negative spring constant is combined with a spring having a positive spring constant.

According to a second aspect of the present invention, there is provided the vibration isolation device according to the first aspect, wherein the spring constant can be changed in a long cycle by a mechanism capable of adjusting a spring having a negative spring constant.

According to a third aspect of the present invention, the seismic isolation device can be adjusted to an arbitrary height by adjusting a spring having a positive spring constant.

According to a fourth aspect of the present invention, one end of each of the pair of links is pivotally connected to the upper mount and the lower mount, and the other end is connected to each of the horizontal moving mechanisms of the lower mount and the upper mount. The lower frame is provided with a first coil spring having a plurality of negative spring constants, a second coil spring having a plurality of positive spring constants, and a third coil spring having a shackle between the lower frame and the upper frame. It is a seismic isolation device.

According to a fifth aspect of the present invention, there is provided the vibration isolator according to the fourth aspect, wherein the horizontal moving mechanism comprises a rail and a linear motion mechanism.

According to a sixth aspect of the present invention, there is provided an anti-vibration isolator according to the fourth or fifth aspect, further comprising an oil damper disposed between the upper and lower mounts.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the apparatus of the present invention, in which a lower mount 1 is arranged on the upper surface of a foundation, and an upper mount 2 is provided in parallel above the lower mount 1 so that a plurality of first coil springs 3 are provided. The right end is connected to the spring connector 6 and the other left end is connected to the lower base 1 so that the strength can be adjusted, and the relationship between the weight of the vibration isolator and the first coil spring 3 is adjusted. A third coil spring 5 having two second coil springs 4 and a shackle 11 is disposed vertically on both sides of the first coil spring 3. In addition, 12 is an oil damper provided between the upper frame 2 and the lower frame 1,
Fast decay. This oil damper 12 does not have to be attached.

FIG. 2 is a side view of the present invention in a normal state, in which an anti-vibration object (not shown) is placed on the upper surface of the upper gantry 2. The first coil spring 3 is provided with a negative spring constant via a link 7 so that the upper mount 2 can move up and down horizontally with respect to the lower mount 1. Downward link 7
The lower end of -1 is pivotally connected to a horizontal moving mechanism 8-2 provided near the end of the lower gantry 1, and the upper end is pivotally connected to the upper gantry 2. This horizontal moving mechanism 8-2 is provided with a rail 9-
2 and a linear motion device 10-2. The lower end of the link 7-2 has its upper end pivotally connected to a horizontal moving mechanism 8-1 provided near the end of the upper mount 2, and its lower end pivotally connected to the lower mount 1. Horizontal movement mechanism 8-
Reference numeral 1 denotes an upper frame rail 9-1 and a linear motion device 10-1. Inside the link is an upper frame 2 and a lower frame 1
Between the two second coil springs 4 and especially the shackle 11
The two third coil springs 5 are normally arranged without a spring action. When each link is pivotally connected to the upper and lower mounts, a bearing of a bearing is used.

FIG. 3 is a side view when the upper gantry 2 is moved upward by vibration.

FIG. 4 is a left half of the side view of FIG.

FIG. 5 is a load-deflection diagram of the first coil spring 3, the second coil spring 4, and the third coil spring 5, and shows the negative spring constant of the first coil spring 3 and the second coil spring 4. Further, when the positive spring constants of the third coil springs 5 are summed up, the slope becomes gentle as shown by the solid line rising to the right, indicating that the cycle is long.

Next, the operation will be described.

In the apparatus of the present invention shown in FIG. 1, FIG. 2 shows that the upper gantry 2 is stationary at normal times. When the upper gantry 2 moves upward due to vibration, the link 7 rises and the linear motion device 10-1 of the upper gantry is at the center of the upper gantry 2, and the linear motion device 10-2 of the lower gantry is at the center of the lower gantry 1. While moving, the second coil spring 4 and the third coil spring 5 are located at the lower left of FIG. The load-deflection diagram of the first coil spring 3 is shown in the upper left of FIG. These first coil spring 3 and second coil spring 3
The total of the characteristics of the coil springs 4 and the third coil springs 5 is a solid line at the lower left of FIG. Conversely, when the upper gantry 2 moves downward due to the vibration acceleration, the pair of links 7 becomes substantially parallel, and the linear motion device 10-1 of the upper gantry moves to the outer end side of the upper gantry 2 and the lower gantry The linear motion device 10-2 moves to the outer end side of the lower base 1 and the load-deflection diagram of the second coil spring 4 is as shown in the upper right of FIG. The third coil spring 5 does not act on the shackle 11 at all, and therefore does not appear at the upper right of the figure. A load-deflection diagram of the first coil spring 3 is shown at the lower right of FIG. The first coil spring 3 and the second
The total of the coil springs 4 has a gentle upward slope from the center point as shown by the solid line in the upper right of FIG.

That is, when the three types of coil springs are used in combination as a set rather than used alone, the load-deflection diagram becomes a gently rising straight line as shown by the solid line in FIG. It can be seen that the natural period becomes a long period. The load can be adjusted by changing the fixed length of the first coil spring 3 according to the weight of the vibration isolator. The height of the device of the present invention can be adjusted by changing the fixed length of the second coil spring 4 fixed to the upper base 2.

[0023]

The present invention provides a spring having a negative spring constant,
By combining three types of coil springs, a spring having a positive spring constant and a spring having a shackle, a compact and long-period seismic isolation device has become possible.

[Brief description of the drawings]

FIG. 1 is a plan view of the device of the present invention,

FIG. 2 is a side view of the device of the present invention in a normal state;

FIG. 3 is a side view when the upper gantry of the present invention is moved;

FIG. 4 shows the left half of the side view of FIG. 1;

FIG. 5 is a load-deflection diagram of a coil spring;

FIG. 6 shows an example of a conventional long-period vibration reduction device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower gantry 2 Upper gantry 3 1st coil spring 4 2nd coil spring 5 3rd coil spring 6 Spring connector 7 Link 8 Horizontal movement mechanism 9 Rail 10 Linear motion device 11 Shackle 12 Oil damper

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[Procedure amendment]

[Submission date] August 6, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

Means for Solving the Problems The present inventors have proposed a vertical coil spring provided between a vertical mount and a horizontal coil spring via a link.
By combining a spring mechanism with a negative spring constant and a spring mechanism with a positive spring constant, specifically combining a link mechanism and a coil spring, a new long-period seismic isolation It is an implementation of the device. That is, the invention of claim 1 is a seismic isolation device in which a mechanism having a spring having a negative spring constant is combined with a spring having a positive spring constant.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroshi Miyano 3-5-3 Tatsumi, Koto-ku, Tokyo Mitsubishi Steel Corporation Environmental Engineering Division (72) Inventor Daisuke Yaguchi 3-5-3, Tatsumi Koto-ku, Tokyo Environmental Engineering Division, Mitsubishi Steel Corporation

Claims (6)

[Claims] 1. A seismic isolation device in which a mechanism of a spring having a negative spring constant and a spring having a positive spring constant are combined. 2. The seismic isolation device according to claim 1, wherein a vertical spring constant can be changed in a long cycle by a mechanism capable of adjusting a negative spring constant. 3. The vibration damping device can be adjusted to an arbitrary height by adjusting a spring having a positive spring constant.
Seismic isolation device. 4. One end of each of the pair of links is pivotally connected to the upper mount and the lower mount, and the other end is pivotally connected to each of the horizontal movement mechanisms of the lower mount and the upper mount. A first coil spring having a plurality of negative spring constants, and a second coil spring having a plurality of positive spring constants and a third coil spring having a shackle between the lower and upper mounts. Shaking device. 5. The seismic isolation device according to claim 4, wherein said horizontal movement mechanism comprises a rail and a linear movement mechanism. 6. An anti-vibration isolator according to claim 4, further comprising an oil damper disposed between the upper mount and the lower mount.