JPH1144086A - Upper and lower vibration-isolation floor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an upper and lower vibration-isolation floor structure, in which a rocking motion is suppressed and floor height is restrained to a low level and a vibrational natural period can also be adjusted freely by permitting a free motion in the vertical direction as the upper floor of double floors is left as it is kept level at all times. SOLUTION: Rack gears 12 are installed integrally at both ends of the upper floor 11 of double floors mounted in a structure building frame 10, and at least two pinion gears 13, 14 are engaged with the upper and lower sections of each rack gear 12 and a shaft is fixed onto the structure building frame 10. Blocks 20 are set up to one pinion gears 14 in the pinion gears in a coaxial manner, and coil springs 22 are stretched among the blocks 20 and the structure building frame 10. A horizontal state can also be maintained at all times during vertical movement in the upper floor 11, and floor height is also suppressed at a low level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base-isolated floor structure for suppressing vertical vibration of a floor, particularly rocking.

[0002]

2. Description of the Related Art A seismic isolation floor structure has been adopted to reduce vibration when a building floor is subjected to seismic force or other external force. Especially in computer rooms, etc., in order to prevent equipment placed on the floor from being damaged and maintain their functions, the weight around the floor is stably supported in normal times, while allowing vertical floor displacement due to vertical vibration during earthquakes. However, a seismic isolation floor structure was required to suppress the rocking movement of the floor, and to achieve this, it was necessary to place considerable seismic isolation equipment under the floor.
As a conventional seismic isolation floor structure of this type, for example, FIGS.
As shown in the figure, the upper floor 2 on which the computer 1 and the like are arranged is directly supported by the air spring 3, the laminated rubber 4, or the coil spring 5 to extend the period, thereby achieving seismic isolation. It has been known.

[0003]

However, in such a conventional vertical seismic isolation floor structure, under the upper floor 2,
There is a problem that it is difficult to keep the floor height low because the air springs 3 and the coil springs 4 as seismic isolation devices are vertically arranged.

Further, in order to prolong the vertical vibration cycle, the total length of the springs of these seismic isolation devices must be considerably long. There is a problem that the natural period of vibration in the direction cannot be adjusted as desired.

The present invention has been made in view of such a problem of the conventional vertical seismic isolation floor structure, and allows free vertical movement while always keeping the upper floor horizontal, thereby achieving rocking. It is an object of the present invention to provide an upper and lower seismic isolation floor structure capable of suppressing motion, keeping the floor height low, and freely adjusting the natural period of vibration.

[0006]

In order to achieve the above object, a vertical seismic isolation floor structure according to the present invention comprises a vertical seismic isolation floor structure which suppresses vertical movement of a double floor provided in a structural body. And a rack gear integrally fixed to and attached to the upper floor of the double floor, and at least two rack gears fixed to a shaft of the structural body and arranged at intervals in a longitudinal direction of the rack gear to mesh with the rack gear. A pinion gear, a pulley coaxially mounted on one of the pinion gears, and an elastic body locked at one end to the pulley and stretched between the pulley and the structural body, and the upper floor moves up and down. It is characterized by maintaining a horizontal state at all times.

Here, as the elastic body, a multistage series elastic body in which a plurality of element elastic bodies are arranged in series can be used. Further, the natural vibration period of the upper floor can be adjusted by adjusting the radius ratio between the pinion gear and the pulley.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing one embodiment of the vertical seismic isolation floor structure of the present invention.

[0009] Reference numeral 10 in the figure denotes a frame of a structure (building). The upper floor 11 is placed on the floor 10A of the structural body 10.
Has a double floor structure. The upper floor 11 is independent of the floor 10A of the structural body 10, and rack gears 12 are vertically fixed to both ends thereof. The rack gear 12 projects above and below the upper floor 11, and the pinion gear 13 meshes with the upper projecting portion,
The pinion gear 14 meshes with the lower protruding portion. Each of the pinion gears 13 and 14 has a circular shape, and its rotation shaft 15 is connected to the outer wall 10 of the structural body 10 via an arm 16.
The rack gear 12 is supported at an inner surface of the rack gear 12 and is spaced apart in the longitudinal direction. As shown, rack gear 1
The pinion gears 2 and the respective pinion gears 13 and 14 are arranged symmetrically to the left and right, so that the upper floor 11 can freely move up and down while keeping a horizontal state at all times.

A pulley 20 is coaxially mounted on the pinion gear 14 below the floor among the upper and lower pinion gears 13, 14. A spring mounting portion 21 is provided upright at the center of the floor 10A of the structural body 10. A coil spring 22 is stretched as an elastic body between the pulley 20 and a spring mounting portion 21 as a structural body. The coil spring 22 has one end 22A at the spring mounting portion 21.
And is disposed parallel to the back surface of the upper floor 11,
The other end 22 </ b> B is locked (fixed) to the outer peripheral portion of the pulley 20. Also, a damper 23 is attached to the spring attachment portion 21 with one end thereof locked to the outer peripheral portion of the pulley 20 at the other end.

The coil spring 22 is a multi-stage series spring formed by attaching a plurality (n) of element springs 22a as shown in FIGS. The spring 22 can be used. The illustrated multi-stage type series spring 22 is a jig 2 to which an element spring 22a is attached.
4 is a guide rail 2 provided inside a spring storage box 25.
The guide 6 prevents the spring from buckling out of the plane and ensures smooth movement. Since the total length is substantially equal to that of the element spring 22a, the installation space can be saved.

Next, the operation will be described. In the vertical seismic isolation floor structure of the present embodiment configured as described above, the upper and lower two pinion gears 13 and 14 are meshed with the rack gears 12 vertically fixed to both ends of the upper floor 11, respectively. 11 can always move freely up and down while keeping horizontal,
Moreover, the rocking movement is suppressed. The weight applied to the upper floor 11 (total weight of the upper floor, rack gears, pulleys, equipment and the like riding on the upper floor, etc.) is determined by the coil spring 2 wound around the pulley 20.
2 and supported by the structural body 10.

When an earthquake occurs, the upper floor 11 vibrates up and down while maintaining a horizontal state. However, since the rocking motion is not performed, damage to devices such as a computer installed on the upper floor 11 can be prevented, and the function can be maintained. The vertical vibration input to the upper floor 11 is converted into the rotational motion of the pinion gear 14, and is further absorbed and attenuated by the expansion and contraction motion of the coil spring 22 via the pulley 20 mounted coaxially. Also, by increasing the period of the vertical vibration,
Effective seismic isolation can be achieved by basically isolating ground motions with short periods. In order to increase the period of the vibration, it is necessary to considerably lengthen the entire length of the coil spring 22. However, in the case of the present embodiment, since the coil spring 22 is disposed horizontally below the floor of the upper floor 11, it is considerably long. It is possible to use a spring, and therefore, it is possible to relatively easily increase the period while keeping the floor height low, and to reduce the earthquake input.

If the coil spring 22 has a multi-stage series spring structure as shown in FIGS. 2 to 4, for example, the natural period of the upper floor 11 in the vertical direction can be made longer. That is, in the case of such a multi-stage series spring, assuming that the spring constant k of each element spring 22a and the number of serialized springs are n, the overall combined spring constant is represented by k / n. Now, assuming that the ratio of the diameter between the pinion gear 14 and the pulley 20 is 1: α and the mass around the upper floor 11 is 2 m, the natural vibration period T around the upper floor 11 which is the seismic isolation part is expressed by the following equation. .

T = 2π (m / k) ^1/2 · (n / α) ^1/2 Therefore, the radius ratio α between the pinion gear and the pulley, the spring constant k of each element spring 22a, and the total number n thereof Is appropriately selected, the natural vibration period T of the upper floor 11 can be arbitrarily adjusted.

FIG. 5 is a schematic view showing another embodiment of the vertical seismic isolation floor structure of the present invention. In this embodiment, a partition wall 30 separated by a space S is erected near an end of an upper floor 11 which is a seismic isolation portion inside an outer wall portion 10B of a structural body 10, and the partition wall 30 is provided inside the space S. For example, the point that the above-described multi-stage series spring 22 is disposed in the vertical direction is different from the first embodiment. Upper and lower pinion gear 1 in this case
The rotating shafts 3 and 14 are also fixed to the structural body 10 although not shown.

In this embodiment, the multi-stage series spring 22 is disposed by effectively utilizing the narrow space S between the outer wall portion 10B of the structural body 10 and the partition wall 30.
Again, it is possible to relatively easily increase the period while keeping the floor height of the upper floor 11 low, and reduce the earthquake input. Other functions and effects are almost the same as those of the first embodiment.

In each of the above embodiments, the case where the rack gears 12 fixed to the ends of the upper floor 11 are arranged vertically above and below the upper floor 11 so as to protrude vertically has been described. May be vertically fixed to only one of the back side and the front side.

Further, as a specific example of the multi-stage series spring, a structure in which a plurality of element springs 22a are attached in series to an angle type jig 24 guided by a guide rail 26 has been described. Instead, another configuration such as a structure in which a plurality of element springs 22a are connected in series to substantially the same length as one element spring 22a while being folded in a zigzag manner via a pulley may be used.

Although the coil spring has been described as an example of the elastic body, the present invention is not limited to this. For example, a rubber spring or the like may be used.

[0021]

As described above, according to the first aspect of the present invention, at least two pinion gears supported by the structure body are provided above and below the rack gear fixed to the upper floor end of the double floor. Since the vertical movement of the upper floor is guided by meshing, the upper floor always keeps a horizontal state even during the vertical movement, so that the rocking movement can be suppressed. At the same time, pulleys are mounted coaxially with one of the pinion gears,
Effective use of the space under the floor or in the partition wall to stretch the elastic body between the pulley and the structure body to support the weight around the upper floor, so that the floor height can be kept low. This has the effect.

According to the second aspect of the present invention, a multi-stage series elastic body in which a plurality of element elastic bodies are arranged in series is used as the elastic body. By appropriately selecting the total number and the like, it is possible to obtain an effect that the vertical natural vibration period of the upper floor portion can be easily adjusted, and also to make the elastic body a straight line when increasing the vibration period. There is no need to dispose them in a space, and the effect of realizing space saving can be obtained.

Further, according to the invention according to claim 3, by adjusting the radius ratio between the pinion gear and the pulley,
The effect is obtained that the vertical natural vibration period of the upper floor portion can be easily adjusted.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a vertical seismic isolation floor structure of the present invention.

FIG. 2 is a conceptual diagram of a multi-stage series spring structure of the present invention.

FIG. 3 is a perspective view schematically showing one embodiment of a multi-stage series spring structure shown in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a schematic view showing another embodiment of the vertical seismic isolation floor structure of the present invention.

FIG. 6 is a schematic diagram showing an example of a conventional vertical seismic isolation floor structure.

FIG. 7 is a schematic diagram showing another example of a conventional vertical seismic isolation floor structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Structure body 11 Upper floor 12 Rack gear 13 Pinion gear 14 Pinion gear 20 Pulley 22 Coil spring (multistage serial spring) 22a Element spring

Claims (3)

[Claims] An up-down seismic isolation floor structure provided in a structural body for suppressing the vertical movement of a double floor, a rack gear integrally fixedly attached to an upper floor end of said double floor, and said structure. At least two pinion gears having a shaft fixed to the body and spaced apart in the longitudinal direction of the rack gear and meshing with the rack gear; a pulley coaxially mounted on one of the pinion gears; An elastic body that is locked at one end side and stretched between the structure body and
An upper-lower seismic isolation floor structure, characterized in that the upper floor always maintains a horizontal state even when it moves up and down. 2. The vertical seismic isolation floor structure according to claim 1, wherein a multi-stage series elastic body in which a plurality of element elastic bodies are arranged in series is used as said elastic body. 3. The seismic isolation floor structure according to claim 1, wherein the natural vibration period of the upper floor can be adjusted by adjusting a radius ratio between the pinion gear and the pulley.