JPH06257272A - Vibration restraint apparatus for double floor - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] A double floor with an appropriate damping coefficient, excellent vibration damping effect of the floor slab, simple structure, no large installation space, and easy construction. A vibration suppressing device is provided. [Structure] The vibration suppressing device 1 is provided with a pillar 3 for a double floor 2 that is erected on a floor slab 5, and a spring member 11 that is arranged so as to surround the pillar 3 and that can extend and contract in the axial direction of the pillar 3.
An upper holder 8 attached to the column 3 and to which the upper end of the spring member 11 is locked; and a lower holder 18 slidably attached to the column 3 and connected to the lower end of the spring member 11. An additional weight 19 mounted on the lower holder 18 and vibration damping devices 16 and 17 provided on the lower holder 18. When the vertical vibration is transmitted to the column 3, the inertial force of the additional weight 19 causes the spring member 11 to expand and contract, and the vibration damping devices 16, 1
While receiving the damping force of 7, the vibration suppressing device 1 generates vibration that acts in a direction of suppressing vertical vibration of the building.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double floor for preventing the information processing device or the like installed on the double floor of the building from being damaged when the building is vibrated by an earthquake or the like. The present invention relates to a vibration suppressing device.

[0002]

2. Description of the Related Art Various vibration control devices for buildings have been developed as disclosed in JP-A-62-170658, JP-A-1-266335, and JP-A-2-190580. The vibration suppressing devices disclosed in these publications effectively suppress the resonance of a floor slab of a building by using a so-called dynamic damper configured by supporting a weight accompanied by motion resistance by a spring. Is.

[0003]

However, with the recent widespread use of various information processing devices and semiconductor manufacturing equipment, double floors (generally, for the purpose of facilitating wiring and air conditioning) , Called the Free Access Floor.)
Became popular. Double-floor is constructed by laying multiple floor panels above the floor slab of a building at regular intervals from the floor slab, so that the normal upper floor of the floor panel and the floor The space below the panel is used for wiring the cables.

When installing a vibration isolator on a floor slab having a double floor, the simplest and most effective method for construction is to install it in the space between the double floor and the floor slab. However, if the vibration isolation device occupies this space, the vibration isolation device may interfere with the wiring of cables and air conditioning. Also,
Due to its structure, the double floor may not be able to obtain a sufficient vibration suppressing effect only by the vibration suppressing device attached to the main body of the building when it receives a vibration such as an earthquake.

The anti-vibration device using an additional vibrating body such as a dynamic damper is different from an anti-vibration method using an elastic support method using anti-vibration rubber or an air spring or an insulating method using an insulating material such as sand or gravel. The vibration of the vibrating body can be positively suppressed by causing the additional vibrating body to substantially resonate with the frequency of the vibration source. This device attaches an additional vibration body formed of a small mass and a spring to a mechanical foundation or structure that is in a steady vibration state where the response magnification may become extremely large when it is excited at a specific frequency. The vibration of the vibrating body is suppressed by making the body almost match the vibration frequency of the vibration generating body. However, the two-mass system vibration model in which the additional vibrating body is coupled to the one-mass system vibration model is used as the underlay. Since the three factors of the mass of the vibrating body, the spring constant of the spring, and the damping coefficient of the damper are important factors for damping the vibration, the natural frequency of the object fluctuates even with the vibration isolator that was completed once. As a result, when the frequency of the forced external force to be damped fluctuates, or when you want to shift the priority target of the vibration dampened object, etc. Can be easily set It is necessary that a structure, such as possible.

As is well known, a spring provides vibration resistance proportional to displacement, whereas a damper provides viscous resistance proportional to vibration speed, and the damping mode changes depending on the size of the damper. That is, for example, when a forced external force is applied in a stepwise manner, the number of vibrations until the vibration is damped to have a constant amplitude depends on the damping coefficient of the damper. However, if the damping coefficient of the damper is set to an extremely large value, damping after the forced external force is applied in an overdamped state is completed in an excessively short time, which makes it uncomfortable to sit on a seat with a hard cushion. If you set the damping coefficient of the damper to an extremely small value,
Underdamped state, vibration continues for a relatively long time after the external force is applied, and you will feel uncomfortable as if you were sitting on a seat with too soft a cushion. Therefore, the selection range of the damping constant is wide enough so that the damping constant of the damper can be set appropriately according to the operating environment, but the damper used for damping the mechanical foundation and the structure itself Since it is huge and various restrictions are imposed due to the arrangement in the limited space between the floor slab and the double floor, it is difficult to install it so that the damping coefficient can be easily changed. Therefore, many of the conventional vibration damping devices have a problem that the adjustment range of the damper is narrow and it cannot sufficiently cope with a wide range of vibration generation sources.

Therefore, an object of the present invention is to provide a vibration damping device for giving an appropriate damping resistance to the additional vibrating body and adjusting the response magnification in the frequency range before and after the vibration damping device so that the floor slab has an appropriate damping coefficient. It is to provide a double floor vibration suppressing device which has an excellent vibration suppressing effect on the double floor, has a simple structure, does not require a large installation space, and is easy to construct.

[0008]

In order to achieve the above object, the device of the present invention has the following configuration. That is, a support for a double floor that is erected on a floor slab, a spring member that is arranged so as to surround the support, and is expandable and contractable in the axial direction of the support, and that is attached to the support, and An upper holder to which an upper end portion of a spring member is locked, a lower holder slidably mounted on the column and connected to a lower end portion of the spring member, and an additional weight mounted on the lower holder. And a vibration damping device that is provided between the lower holder and the column and that damps vibrations by friction, and is a double floor vibration suppressing device.

[0009]

The vibration suppressing device having such a structure mainly exhibits a vibration suppressing function when vertical vibration occurs in a building. Vertical vibrations of the building are transmitted from the floor slab to the double-floor columns, and from these columns to the double floors such as floor panels. When the vertical vibration is transmitted to the support, the spring member expands and contracts due to the inertial force of the additional weight to generate vibration that acts in a direction to suppress the vertical vibration of the building. This vibration generated by the vibration suppressing device is transmitted to the floor slab and the double floor to suppress the vertical vibration of the floor slab and the double floor. In order for the vibration suppressor to effectively dampen the vertical vibration of the floor slab and double floor, the vibration frequency of the inertial force generated by the vibration suppressor is such that the natural frequency of the floor slab and double floor within a certain range. Must be equal to. In order to adjust the frequency of vibration generated by the vibration suppressing device, one or both of the spring force of the spring member and the weight of the additional weight are changed.

Since the vibration suppressing device of the present invention has a vibration damping device as one of its constituent elements, this vibration damping device gives an appropriate damping resistance to an additional vibrating body such as an additional weight, and the frequency range before and after this The response magnification of can be adjusted.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vibration suppressing device 1 of the present invention with a double floor 2
It is a longitudinal cross-sectional view of the state installed in the column 3. The pillar 3 is
It has a pillar main body 4 formed of a hollow cylinder, a support substrate 6 fixed to the floor slab 5 to support the lower end of the pillar main body 4, and a floor panel support member 7 fixed to the upper end of the pillar main body 4. As shown in FIG. 1, an upper holder 8 is fitted on the outer peripheral surface of the column 3, and is fixed to the upper portion of the column 3 by bolts 9 and nuts 10 so as not to rotate. The upper holder 8 is integrally formed of a material such as synthetic resin. One spiral groove 8a is formed on the outer peripheral surface of the upper holder 8, and the upper end of the spring member 11 is slidably engaged with the groove 8a.

As shown in FIG. 4, on the outer peripheral surface of the column 3,
The pair of guide rail holders 12 and 13 are fixed with their phases shifted by 180 degrees. These guide rail holders 12 and 13 are respectively constituted by guide rail holder halves 12a, 12b, 13a and 13b,
These guide rail holder halves 12a, 12b, 13
a and 13b have guide rails 14a, 14b and 1 between them.
It is fixed by a tightening belt k so as to extend in the axial direction of the column 3 while sandwiching 5a and 15b. The tightening belt k is fixed by a bolt 1 and a nut m. The guide rails 14a, 14b, 15a, 15b are made of aluminum alloy mold material, and the guide rail holder 12,
It is installed so as to be inclined so as to form a valley at the center of 13. These guide rails form a part of friction type vibration damping devices 16 and 17 (described later) as shown in FIG.

The upper end of the spring member 11 is the upper holder 8
And extends downward, and a lower holder 18 is engaged with the lower end portion thereof. The lower holder 18 has a tubular portion 18a with which the spring member 11 engages and a flange portion 18b formed at the lower end portion of the tubular portion 18a. The tubular portion 18a and the flange portion 18b are made of a synthetic resin material. Etc. are integrally formed. Similar to the upper holder 8, a spiral groove 18c is formed on the outer peripheral surface of the tubular portion 18a, and the lower end of the spring member 11 is slidably engaged with the groove 18c. As a result, the lower holder 18 includes the column 3, the guide rail holders 12 and 13, and the guide rails 14a and 14a.
It is supported by the spring member 11 and is vertically movable at a position surrounding b, 15a, and 15b.

An additional weight 19 is placed and fixed on the upper surface of the flange portion 18b of the lower holder 18. The additional weight 19 has two semi-cylindrical parts 19 as shown in FIG.
Each of the semi-cylindrical portions 19a and 19b is formed by stacking a plurality of semi-circular plate-shaped weights w and fastening them with bolts 20 and nuts 21. The semi-cylindrical parts 19a and 19b are respectively provided with a flange 22b of the lower holder 18 by a bolt 22 and a nut 23.
Fixed to. The bolt 22 is engaged with the notch portion 18d formed in the flange portion 18b of the lower holder 18 (see FIG. 2), is inserted into the hole h formed in each plate-shaped weight w, and is fastened by the nut 23. Then, the flange portion 18b is fixed.

Friction type vibration damping devices 16 and 17 are mounted on the lower surface of the flange portion 18b of the lower holder 18, and these vibration damping devices 16 and 17 are arranged on both sides of the column 3 with the column 3 interposed therebetween. . Each vibration damping device 16, 17
Is the spring case 2 formed on the flange portion 18b.
4, the cylinder 24a formed inside the spring case 24, the friction shoe 25 slidably mounted on the cylinder 24a, and the friction shoe 25 in the corresponding guide rails 14a, 14b, 15a, 15b direction at all times. The compression coil spring 26 that urges the compression coil spring 26 and the surface pressure adjusting screw 27 for adjusting the surface pressure of the compression coil spring 26.
Have and.

The friction shoes 25, 25 are pressed against the sliding contact surfaces of the corresponding guide rails 14a, 14b, 15a, 15b by the compression coil springs 26, respectively. Generates frictional force. In this embodiment, the compression coil spring 26, the cylinder 24a, and the surface pressure adjusting screw 27 elastically urge the friction shoe 25 against the guide rails 14a, 14b, 15a, 15b forming the sliding contact surface. Make up. The compression coil spring 26 used has a relatively small spring constant and is largely bent from its natural length to be housed in the cylinder 24a. Therefore, the friction shoe 25 or the guide rails 14a, 14b, 15a are accommodated. Even if the sliding contact surfaces of 15 and 15b are worn due to friction, it is possible to suppress the fluctuation of the spring constant to a negligible amount, whereby the damping coefficients of the vibration damping devices 16 and 17 are set for a long period of time. It is possible to match the value and prevent aging.

Support substrate 6 for supporting the lower end of the pillar body 4
Is a substrate plate 6a adhered to the floor slab 5 of the building with an adhesive or the like, a height adjusting bolt 6b erected on the substrate plate 6a, a height adjusting nut 6c screwed to the bolt 6b, and The rotation adjusting screw 6d is attached to the adjusting nut 6c. The height adjusting nut 6c is formed with a support surface 6e for supporting the lower end portion of the strut body 4, and the lower end portion of the strut body 4 is erected on the nut 6c by engaging with the support surface 6e.

As shown in FIG. 5, the support columns 3 are floor slabs 5.
A plurality of adjacent columns 3 are arranged at a predetermined interval above
A stringer 29 for supporting the floor panel 28 is bridged between them. The stringer 29 is the strut body 4
The floor panel support member 7 fixed to the upper end of the floor panel 28 supports the ends thereof, and the upper surfaces of the stringers 29 support the lower surfaces of the edge portions of the floor panel 28. And
The four corners of the floor panel 28 are fixed to the floor panel support member 7 from the upper surface side of the floor panel 28 by the floor panel retainers 30.

As shown in FIG. 5, the vibration suppressing device 1 of the present invention does not have to be installed on all of the columns 3 supporting the double floor 2, but the columns 3 of the double floor 2 at the required positions. Need only be installed in Further, as shown in the figure, it is desirable to cover the vibration suppressing device 1 with a protective cover 31. The protective cover 31 is configured by combining a plurality of semi-cylindrical members 32 in a tubular shape as shown in the figure, and is installed on the column 3 so that the protective cover 31 covers the outer periphery of the vibration suppressing device 1. By using the protective cover 31, a cable or the like (not shown) laid between the double floor 2 and the floor slab 5 comes into contact with a movable part such as the additional weight 19 of the vibration suppressing device 1 to suppress the vibration. It is possible to prevent the operation of the device 1 from being impaired.

As shown in FIGS. 1 and 6, when the vibration suppressing device 1 vibrates in the vertical direction together with the floor slab 5 and the double floor 2, the spring force of the spring member 11 and the inertial force of the additional weight 19 cause a lower portion. The holder 18 vibrates vertically. When the lower holder 18 vibrates in the vertical direction, the vibration damping device 16,
The friction shoes 25, 25 of 17 are the guide rails 14a, 1
The sliding contact surfaces 141a, 141b, 151 of the guide rail from the valley portion V formed in the connecting portion of 4b, 15a, 15b.
The vibration frequency generated by the vibration suppression device 1 is limited within a certain range by the frictional force generated between the friction shoe 25 and the guide rails 14a, 14b, 15a, 15b which moves up and down while being pressed against the a, 151b. . Vibration damping device 16, 17
Has a function of imparting an appropriate damping resistance to the additional vibrating body such as the additional weight 19 by the generated frictional force and adjusting the response magnification in the frequency range before and after this.

Here, the frequency generated by the vibration suppressing device 1 means the frequency generated by the lower holder 18 moving up and down together with the additional weight 18. Further, the constant frequency range generated by the vibration suppression device 1 means that the range of frequencies generated by all the vibration suppression devices 1 on the floor slab 5 is the natural frequency of the double floor 2 and the floor slab 5. It is a constant range that includes the natural frequency and spreads before and after it. By setting the frequency of vibration generated by the vibration suppressing device 1 in this way, it is possible to effectively suppress the vertical vibration of the floor slab that the building receives due to an earthquake or the like.

The vibration frequency generated by each vibration suppressing device 1 is adjusted by changing the spring constant of the spring member 11 or the weight of the additional weight 19. this house,
The spring constant of the spring member 11 is changed by changing the spring member 11 into spiral grooves 8a, 18 of the upper holder 8 and the lower holder 18.
It is performed by rotating along c and changing the effective length of the spring member 11. The weight of the additional weight 19 is changed by changing the number of plate-shaped weights w.
The vibration frequency generated by each vibration suppression device 1 may be changed by changing either or one of these, or both of them.

Further, the vibration damping devices 16 and 17 provided between the lower holder 18 and the column 3 provide the additional weight 19 with a vibration resistance equivalent to a viscous resistance proportional to the displacement of the spring member 11. Provides viscous resistance proportional to vibration speed. Therefore, the damping mode changes depending on the magnitude of the damping coefficient of the vibration damping devices 16 and 17, and, for example, when a forced external force is applied in a stepwise manner, the number of times of damping vibrations until damping to a vibration of a constant amplitude The number of times depends largely on the damping coefficient. In the embodiment, the surface pressure adjusting screw 27
The maximum screw-in amount is sufficiently secured, and the spring force of the compression coil spring 26 can be adjusted in a wide range when the surface pressure adjusting screw 27 is rotated in the forward and reverse directions.
Therefore, the optimum damping can be selected for the target forced vibration, the damping constant can be freely selected according to the usage environment, and it is possible to deal with a wide range of vibration generation sources with a margin.

Although the compression coil spring 26 is housed in the spring case 24 integrally formed with the lower holder 18 in the above embodiment, the vibration damping device 4 shown in FIG.
As in the case of 0, the compression coil spring 26 can be housed in the spring case 41 that is screwed and fixed to the lower holder 18. In this embodiment, a hook-shaped protrusion 42 for preventing the friction shoe 25 from coming off is formed along the inner circumference of the opening of the bottomed cylindrical spring case 41, and the protrusion 42 is expanded to extend inside the spring case 41. After the friction shoe 25 is stored, the friction shoe 25 is prevented from falling off unless the protrusion 42 is expanded with a tool or the like. Further, the spring case 4 is attached to the surface pressure adjusting screw 27.
The lock nut 43 that locks to the bottom surface of 1 is screwed, and by tightening the lock nut 43 after screwing the surface pressure adjusting screw 27 to an appropriate position,
The surface pressure adjusting screw 27 can be prevented from loosening.
Also in this embodiment, the frictional force of the friction shoe 25 can be varied in an analog manner according to the screwing depth of the surface pressure adjusting screw 27, and the damping coefficient can be finely adjusted through delicate surface pressure adjustment. Is.

Further, in the above embodiment, the spring force of the compression coil spring 26 is adjusted by the surface pressure adjusting screw 27, but like the vibration damping device 45 shown in FIG. 8, the spring case 41 and the compression coil spring 26 are adjusted.
A plurality of surface pressure adjusting shims 46 are inserted between the compression coil spring 2 and the surface pressure adjusting shim 26.
The spring force of 6 may be adjusted. In this case, the damping coefficient can be switched in a discrete value according to the number of the surface pressure adjusting shims 46 used, and the surface pressure can be accurately grasped.

Furthermore, in each of the above-mentioned embodiments, the case where the pair of vibration damping devices 16, 17 or 40 or 46 are arranged to face each other around the support column 3 has been taken as an example, but as shown in FIG. For example, three vibration damping devices 46 may be arranged around the support column 3 at intervals of 120 ° from each other, and as shown in FIG. 10, four vibration damping devices 46 may be mounted around the support column 3. They may be arranged 90 ° apart from each other. Also, the vibration damping device 46 or 40, and further 1
It is possible to use five or more six and seventeen, and by arranging a plurality of vibration damping devices in parallel, it is possible to prevent the lower holder 18 from rolling laterally when the additional weight 19 vibrates up and down, and to provide stable damping vibration. Can be promised.

[0027]

As described above, since the vibration suppressing device of the present invention is installed on the pillar for supporting the double floor,
It becomes possible to dispose this vibration suppressing device centrally in the double floor. Therefore, it is possible to effectively perform vibration isolation according to the vibration characteristics of the floor slab.

Further, the vibration suppressing device of the present invention is installed around a pillar for supporting the double floor as a center.
Moreover, since the respective constituent elements of this device are distributed along the axis of the support column in the longitudinal direction of the support column, the overall size of the device can be reduced and the installation does not occupy a large space. Therefore, when laying a cable or the like in the space between the double floor and the floor slab, the vibration suppressing device does not interfere. Further, since the device is small, each component is also small, and there is an effect that the manufacturing and assembling thereof are easy.

Further, since this vibration suppressing device is installed in a plurality of columns in a dispersed manner, each vibration suppressing device is relatively lightweight and easy to handle. Moreover, when constructing the double floor, since the vibration suppressing device is also constructed at the same time, it does not affect the construction process.

Further, since the vibration damping device for damping the vibration by friction is provided between the lower holder and the support, the frequency band in which the vibration can be suppressed is expanded, and moreover, the viscous resistance proportional to the vibration speed is added to the additional weight. The damping mode can be changed according to the magnitude of the damping coefficient, and for example, by setting the damping coefficient to a large value, the damping after the forced external force is applied can be completed in a short time, or vice versa. It is possible to freely select the damping constant according to the operating environment, such as by setting a small value and slowly suppressing the vibration when a forced external force is applied, and it is possible to deal with a wide range of vibration sources with a margin.

Further, the vibration damping device can prevent the response magnification of the vibrating body from increasing in the frequency band range around the natural frequency.

The damping force of the vibration damping device is basically adjusted by changing the inclination angle of the guide rail and the spring constant of the spring for pressing the friction shoe. According to this vibration damping device, , A stable damping characteristic is obtained in which the energy consumption per cycle is proportional to the displacement of the friction shoe and the pressing force, and is equivalent to the velocity proportional damping (for example, damping utilizing fluid).

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a state where a vibration suppressing device of the present invention is installed on a pillar of a double floor.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view showing a main part of a vibration suppressing device according to the present invention.

FIG. 4 is an exploded perspective view showing a mounting state of a guide rail holder and a guide rail.

FIG. 5 is a perspective view showing a state in which a double floor is supported by using the vibration suppressing device of the present invention.

FIG. 6 is a vertical sectional view showing a schematic configuration of a vibration damping device.

FIG. 7 is a vertical cross-sectional view showing a modified example of the vibration damping device shown in FIG.

8 is a vertical cross-sectional view showing a modified example of the vibration damping device shown in FIG.

9 is a vertical cross-sectional view showing a modified example of the vibration suppressing device shown in FIG.

10 is a vertical cross-sectional view showing another modification of the vibration damping device shown in FIG.

[Explanation of symbols]

 1, 51 ... Vibration suppressor 2 ... Double floor 3 ... Strut 4 ... Strut body 5 ... Floor slab 6 ... Support substrate 7 ... Floor panel support member 8 ... Upper holder 8a ... Spiral groove 9 ... Bolt 11 ... Spring member 14a, 14b, 15a, 15b ... Guide rails 141a, 141b, 151a, 151b ... Sliding contact surfaces 16, 17, 40, 45 ... Vibration damping device 18 ... Lower holder 18c ... Spiral groove 19 ... Additional weight 24 ... Spring case 25 ... Friction shoe 27 ... Surface pressure adjusting screw 41 ... Spring case 42 ... Protrusion 46 ... Surface pressure adjusting shim

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaharu Seki 1-6, Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Hitoshi Okita 1-1-6, Uchiyuki-cho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Toshifumi Ninomiya 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Yukio Sawabe 5-8 Akihabara, Taito-ku, Tokyo Shares Company NTT Building Research Institute (72) Inventor Takao Okumura 1-1-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Naka Technical Research Institute Co., Ltd. (72) Inventor Tatsuo Shoji, Uchiyuki-cho, Chiyoda-ku, Tokyo Naka 1-1 Technical Co., Ltd., Inc. (72) Inventor Seiji Shimura 1-1 1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Naka Corporation, Inc. Surgery within the Institute

Claims (7)

[Claims] 1. A support for a double floor that is erected on a floor slab, a spring member that is arranged so as to surround the support, and is expandable / contractible in the axial direction of the support, and is attached to the support. And an upper holder to which the upper end of the spring member is locked, a lower holder slidably mounted on the column and connected to the lower end of the spring member, and mounted on the lower holder. A double floor vibration suppressing device comprising: an additional weight and a vibration damping device that is provided between the lower holder and the column and that damps vibration by friction. 2. The vibration damping device comprises: a sliding contact surface formed on the column, a friction shoe supported by the lower holder and sliding in contact with the sliding contact surface, and the friction shoe. The double-floor vibration suppression device according to claim 1, characterized in that the double-floor vibration suppression device comprises an elastic means that presses the contact surface. 3. The vibration damping device includes a plurality of sliding contact surfaces provided around the support column and spaced apart from each other by substantially the same distance, and a plurality of sliding contact surfaces supported by the lower holder and contacting the corresponding sliding contact surfaces. The double floor vibration suppressing device according to claim 1, comprising a plurality of sliding friction shoes and a plurality of elastic means for pressing the friction shoes against the sliding contact surfaces. 4. The slidable contact surface comprises a pair of inclined surfaces extending in a direction along the axis of the support column and continuous with each other, and the pair of inclined surfaces respectively have connecting portions of the both inclined surfaces. The double floor vibration suppressing device according to claim 2 or 3, wherein the double floor vibration suppressing devices are inclined in opposite directions so as to form a valley. 5. The guide rail is formed with the sliding contact surface, and a guide rail holder is attached to an outer peripheral surface of the column, and the guide rail has the sliding contact surface extending in an axial direction of the column and the guide rail holder. The double floor vibration suppressing device according to claim 2 or 3, wherein the support rail is attached to the guide rail holder so that a central portion of the pillar in the axial direction forms a valley portion. 6. The elastic means includes a spring, one end of which engages with the friction shoe to urge the friction shoe in a direction of pressing the friction shoe against the sliding surface, and a spring case formed in the lower holder. 3. The surface pressure adjusting screw, which is screwed so as to be able to move forward and backward with respect to the spring case and has a tip end that locks the other end of the spring.
Or the double-floor vibration suppression device described in 3. 7. The elastic means includes a spring, one end of which is locked to the friction shoe and biases the friction shoe in a direction in which the friction shoe is pressed against the sliding contact surface; and a spring case formed in the lower holder. The double floor vibration according to claim 2 or 3, comprising a surface pressure adjusting shim that is interposed between the spring case and the other end of the spring to adjust a surface pressure of the spring. Suppressor.