JP6796945B2 - Seismic isolation device - Google Patents

Description

The present invention relates to a seismic isolation device.

Seismic isolation devices are used as one of the earthquake countermeasures, and not only large structures such as buildings, but also seismic isolation devices for ceramics and fine arts, small and lightweight equipment, tropical fish tanks, etc. are used. Has been done.

Seismic isolation devices for small and lightweight devices are devices that apply principles such as rolling and sliding seismic isolation. For example, they have a structure with two or more layers above and below, with rollers and balls arranged between them. , The energy of seismic isolation is absorbed by using rolling friction.

For example, a seismic isolation device for small and lightweight objects such as arts and crafts is disclosed in Patent Document 1, which has a lower substrate and an upper base plate located on the substrate, and is spherical. A middle plate that rotatably supports the rotating body by abutting the substrate located at the bottom and the base plate located at the top is slidably and non-fixedly arranged between the substrate and the base plate, and the substrate and the base plate are arranged. Is configured by being urged by elastic members such as a plurality of coil springs and rubber springs so that the base plate returns directly above the substrate.

JP-A-2007-239907

In such a seismic isolation device of Patent Document 1, a plurality of elastic members, for example, four coil springs, are placed at equal intervals of 90 degrees with respect to the center of the base plate in order to return the base plate directly above the base plate. It is connected to the board. These coil springs are arranged in the radial direction with respect to the center of the base plate so that the expansion / contraction direction of the coil spring coincides with the radial direction which is the mounting direction of the coil spring.
Therefore, when the base plate moves due to the earthquake motion, the center of the base plate moves in one of the radial directions, and depending on the direction of the earthquake motion, resonance occurs at the natural frequency of the coil spring, and the expansion and contraction directions match. There is a problem that vibration is amplified by the coil spring.
Further, in order to secure the range of motion of the seismic isolation device, it is necessary to secure a space in which the coil spring is compressed, which causes a problem that the device becomes large by that amount.
Furthermore, if the seismic isolation device itself is to be miniaturized, the base plate will become smaller, and the distance from the center of the base plate of the spherical rotating body will become smaller, making it impossible to stably place the load on the base plate. Problems arise.

On the other hand, the rectangular seismic isolation device has the following problems.
In the case of a rectangular seismic isolation device, a load having a large aspect ratio is often loaded, but a load having a large aspect ratio such as an LCD TV is vulnerable to vibration in the width direction. Therefore, if the expansion / contraction direction of the coil spring coincides with the width direction of the base plate and resonance occurs, the load may fall even with a relatively small earthquake motion.

The present invention has been made in view of the problems in the prior art, and can prevent the amplification of vibration due to resonance at the natural frequency of the elastic member for returning to the origin, and secure a sufficient movable range. The aim is to reduce the size of the device and provide a seismic isolation device that can stably load luggage.

In order to solve the above problems, we have conducted extensive studies on elastic members that have the effect of attenuating the energy of the seismic motion of the seismic isolation device and urge the loading plate member on which the load is loaded to return to the origin. Since the elastic members of the above are installed so that their expansion and contraction directions and movement directions coincide with each other, when resonance occurs at the natural frequency of the elastic members, a phenomenon occurs in which the elastic members whose expansion and contraction directions match amplify the vibration. I found that.
In addition, in a rectangular seismic isolation device , it has been found that if the elastic member resonates in the width direction, the load may fall even with a relatively small seismic motion.
Therefore, it was found that shifting the moving direction of the loading plate member, particularly the width direction of the loading plate member and the expansion / contraction direction of the elastic member is effective in preventing the amplification of vibration, and completed the present invention.
Further, it is effective to secure the range of motion and to reduce the size of the seismic isolation device by shifting the width direction of the loading plate member and the expansion / contraction direction of the elastic member to make the space where the elastic member is compressed extremely small. It turned out to be.
The specific configuration of the present invention based on such findings is as follows.

That is, the seismic isolation device of the present invention
A seismic isolation device in which a load plate member is movably installed on a base plate member via a sliding member, and has a plurality of elastic members connecting the base plate member and the load plate member described above.
A strut portion is provided at the center of the base plate member in the width direction.
The sliding members are arranged at both ends in the width direction of the load plate member described above.
The elastic member connects the strut portion and the sliding member, and the strut portion does not coincide with the width direction of the load plate member described above, and the strut portion is a sliding member at both ends in a stationary state. It is provided so as to be located in the middle.
Also,
A sliding member is provided on the support column portion.

According to the seismic isolation device of the present invention, it is possible to prevent the amplification of vibration due to resonance at the natural frequency of the elastic member, secure a sufficient range of motion, reduce the size of the device, and stably load the load. be able to.

It is schematic cross-sectional view which concerns on one Embodiment of the seismic isolation device of this invention. It is a schematic bottom view which omitted a part of the base plate member which concerns on one Embodiment of the seismic isolation device of this invention. It is a schematic bottom view which omitted a part of the base plate member which concerns on another embodiment of the seismic isolation device of this invention. It is a schematic bottom view which omitted a part of the base plate member which concerns on another embodiment of the seismic isolation device of this invention. It is a schematic bottom view which omitted a part of the base plate member which concerns on another embodiment of the seismic isolation device of this invention. It is a schematic bottom view which omitted a part of the base plate member which concerns on another embodiment of the seismic isolation device of this invention. It is a schematic bottom view which omitted a part of the base plate member which concerns on another embodiment of the seismic isolation device of this invention. It is the schematic bottom view which omitted a part of the base plate member explaining the arrangement and the operation principle of the elastic member which concerns on another embodiment of the seismic isolation device of this invention.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
The seismic isolation device 10 of the present invention is not a large structure such as a building, but a device used for seismic isolation of a load such as a relatively small and lightweight device. By using the seismic isolation device 10 as one unit and using a plurality of units in combination, it can be used for seismic isolation of a load having a size and weight according to the number of units. Further, in principle, the seismic isolation device of the present invention does not limit the weight of the load.

As shown in FIG. 1, the seismic isolation device 10 includes a base plate member 11 placed on a floor surface or a table, and a load plate that can be moved on the base plate member 11 via a sliding member 14. The member 12 is provided with a plurality of elastic members 13 connected between the base plate member 11 and the loading plate member 12.
Examples of the sliding member 14 include a rolling member and a sliding member, and the rolling member will be described as an example.
As shown in FIG. 2, the elastic member 13 is composed of a plurality of coil springs, and is a first spring connecting point 16 which is a connecting point (first connecting point) of the elastic member 13 of the strut portion 11b of the base plate member 11. (Hereinafter referred to as a spring connecting point 16) and a second spring connecting point 17 (hereinafter referred to as a spring connecting point 17) serving as a connecting point (second connecting point) of the elastic members 13 at both ends of the loading plate member 12. Is connected to.
That is, as shown in FIG. 2, each elastic member 13 has the width direction A of the loading plate member and the spring connecting point 16 and the other end connecting portion 13b of the strut portion 11b to which the one end connecting portion 13a of each elastic member 13 is attached. Is arranged so as not to coincide with the expansion / contraction direction B connecting the spring connecting points 17 at both ends to which the is attached. Further, one end connecting portions 13a of the two elastic members 13 are connected to each spring connecting point 16, and each of the two elastic members 13 sandwiches the width direction A of the loading plate member 12 passing through the spring connecting point 16. It is evenly distributed on both sides.

The base plate member 11 of the seismic isolation device 10 is fixedly installed on a floor surface or the like, for example, a plate-shaped lower plate 11a and, for example, a rod-shaped or dot-shaped strut portion 11b protruding upward in the center in the width direction. It is configured with and. The strut portion 11b is provided with a spring connecting point 16 to which one end connecting portion 13a of the elastic member 13 is connected.
A load plate member 12 is arranged on the base plate member 11. The loading plate member 12 includes a plate-shaped loading plate 12a and both end portions 12b arranged at both ends in the width direction of the loading plate 12a. The loading plate 12a is formed to be smaller than the lower plate 11a. A load such as a device is placed on the load plate 12a.
Inside both end portions 12b of the loading plate member 12, spring connecting points 17 to which the other end connecting portions 13b of the elastic member 13 are connected are provided.
A tension coil spring is connected as an elastic member 13 between the spring connecting point 16 and the spring connecting points 17 on both ends via the connecting portion 13a at one end and the connecting portion 13b at the other end.

In the seismic isolation device 10, the sliding member 14 is arranged near the spring connecting point 17, which is the second connecting point of the elastic member 13, or outside the spring connecting point 17.
That is, in the seismic isolation device 10, a plurality of spherical rotating bodies 14a are provided as sliding members 14 on the lower surfaces of both end portions 12b near the spring connecting points 17 of the loading plate member 12, and in the illustrated example, 5 on each end portion. A number of spherical rotating bodies 14a are attached via a support frame 14b. The sliding member 14 supports the loaded load placed on the loading plate 12a in a stable state, and rolls and moves on the lower plate 11a. The number of sliding members 14 is set so that the sliding members 14 move in a stable state and can support a load.
As a result, the loading plate member 12 can move in an arbitrary direction via the spherical rotating body 14a in a frictional state in a range until both end portions 12b of the loading plate 12a hit the support column portion 11b on the lower plate 11a. It is configured so that so-called rolling seismic isolation is performed.
Further, since the sliding members 14 are provided at both ends 12b of the loading plate member 12, the loading plate 12a always supports the load in a stable state and rolls regardless of the position of the load on the loading plate 12a. You can move.

In this embodiment, the lower plate 11a of the base plate member 11 itself is made of a member having low friction so that the spherical rotating body 14a can roll more smoothly. The surface roughness of the member having low friction in this case is selected so that the spherical rotating body 14a can roll without slipping.
In addition, in order to reduce friction, a plate-shaped friction reducing member may be separately attached on the lower plate 11a of the base plate member 11 so that the spherical rotating body 14a can roll smoothly.
Further, the sliding member 14 may be provided with sliding members on the lower surfaces of both end portions 12b instead of the spherical rotating body illustrated above so that so-called sliding seismic isolation may be performed. In this case, both end portions 12b themselves may be used as a low friction material.

Further, as shown in FIG. 1, the sliding member 14 may be installed on the support column portion 11b of the base plate member 11. It is preferable to provide the sliding member 14 on the support column 11b because the load plate member 12 moves smoothly even if the load is large or heavy.
A friction reducing member may be attached instead of the sliding member 14.

In such a seismic isolation device 10, a tension coil spring is connected as an elastic member 13 to the load plate member 12 which is movable on the base plate member 11 via the sliding member 14. As a result, the load plate member 12 is held in the center of the base plate member 11 (return to the origin) by a plurality of elastic members 13 composed of tension coil springs, and the energy at the time of vibration due to an earthquake is absorbed to reduce the response acceleration. Let me.

Further, in the seismic isolation device 10, one end connecting portion 13a of the elastic member 13 is connected to the spring connecting point 16, and the other end connecting portion 13b of the elastic member 13 is connected to the spring connecting point 17. As a result, the expansion / contraction direction of the elastic member 13 is the expansion / contraction direction B connecting the connecting portion 13a at one end and the connecting portion 13b at the other end, and is deviated from the width direction A of the loading plate member.
Therefore, even if the expansion / contraction direction B of each elastic member 13 does not overlap with the width direction A of the loading plate member and the seismic motion resonates with the natural frequency of the spring of the elastic member 13, the vibrations of each elastic member 13 are amplified. Can be prevented.

Further, the expansion / contraction direction of the elastic member 13 is the direction B connecting the connecting portion 13a at one end and the connecting portion 13b at the other end, which is different from the width direction A of the loading plate member 12, so that a sufficient range of motion (loading) is obtained. The range of motion of the plate member 12) can be secured.
For example, as shown in FIG. 8, even if the direction C of the seismic motion coincides with the width direction A of the loading plate member 12, the elastic member 13 enters between the first spring connecting point 16 and the second spring connecting point 17. , It is prevented from limiting the range of motion of the loading plate member 12. As a result, the seismic isolation device 10 can be miniaturized when the same movable range is secured, unlike the conventional seismic isolation device in which the movable range is limited.

Even if the seismic motion resonates with the natural frequency of the spring of the elastic member 13 by shifting the expansion / contraction direction B of the elastic member 13 and the width direction A of the loading plate member 12, the elastic members of each other For the effect of preventing the amplification of vibration due to 13, it is desirable that the amount of deviation between the expansion / contraction direction B and the width direction A is large.
Further, even if the moving direction of the loading plate member 12 may move in the expansion / contraction direction B of some elastic members 13, it does not overlap with the expansion / contraction direction B of the other elastic members 13, so that it resonates with the natural vibration of the spring. In this case, the frequencies of each other are canceled out and the vibration can be suppressed from being amplified.
Further, even if the moving direction of the loading plate member 12 is the width direction A of the loading plate member 12, it does not coincide with the expansion / contraction direction B of the elastic member 13, so that the amplification of vibration can be suppressed.

Further, in the seismic isolation device 10, since the rolling members 14 are provided at both ends 12b of the loading plate member 12, the loading plate 12a is always loaded in a stable state regardless of the position of the loading on the loading plate 12a. Can be rolled and moved on the lower plate 11a of the base plate member 11.

It should be noted that the present invention is not limited to the above embodiment, as long as the expansion / contraction direction B of all the elastic members 13 and the width direction A of the loading plate member 12 do not coincide with each other. The member 13 may be configured such that the load plate member 12 is stationary with respect to the base plate member 11 at the origin (center of the base plate member 11).

For example, as shown in FIGS. 3, 4, and 5, in a state where the elastic force of the elastic member 13 does not act (resting state), the expansion / contraction direction B of the elastic member 13 is shifted from the width direction A of the loading plate member 12. If there is, the number, arrangement type, pitch, etc. of the elastic members 13 do not matter.
It is also possible to combine elastic members 13 having different elastic constants. For example, as shown in FIG. 6, in consideration of the elastic constant, the length of the elastic member, the pitch to be arranged, and the like, both end portions 12b of the loading plate member 12 should be positioned symmetrically with respect to the support column portion 11b of the base plate member 11. Just do it.
With such a seismic isolation device 10, in the same manner as the seismic isolation device 10 described above, in addition to damping the energy of the seismic motion and suppressing resonance, sufficient securing of the movable range of the loading plate member 12 and the loading plate member 12 It will have the effect of ensuring stable movement. Further, when the same range of motion is secured, the seismic isolation device 10 can be miniaturized.

Further, the support column portion 11b of the base plate member 11 may have a rod shape as shown in FIGS. 2, 3, 4, 5, and 6, or a dot shape as shown in FIG. 7.

In such a seismic isolation device 10, in order to make the seismic isolation effect due to the arrangement of the elastic member 13 more effective, it is necessary to select the elastic member 13 having a spring constant k appropriate for the load applied to the loading plate member 12. is there.
For example, when the load amount of the loading plate member 12 is less than 10 kg, the spring constant k is preferably 0.0015 or more and 0.0040 N / mm or less.
Further, when the load amount on the loading plate member 12 is 10 kg or more and 50 kg or less, the spring constant k of the elastic member 13 is preferably 0.0020 or more and 0.0060 N / mm or less.

Further, the loading plate member 12 (loading plate 12a of the loading plate member 12) connected by the elastic member 13 has a range on the base plate member 11 until both end portions 12b come into contact with the central strut portion 11b of the base plate member 11. However, when the load is less than 10 kg, the movement distance (range of motion) is 16 cm (8 cm each up and down because it moves up and down) or more on the base plate member 11. It is desirable to do. When the load amount is 10 kg or more and 50 kg or less, the load plate member 12 connected by the elastic member 13 can move 20 cm or more (10 cm each up and down because it moves up and down) on the base plate member 11. Is desirable.
In order to secure the moving distance of the loading plate member 12, it is necessary to secure the space of the elastic member 13 that is compressed with the movement. However, as shown in FIG. 8, the seismic isolation device 10 is elastic. Since the expansion / contraction direction B of the member 13 and the width direction A of the loading plate member 12 are deviated from each other, it is possible to easily secure the expansion / contraction space of the elastic member 13 and to reduce the size of the seismic isolation device 10.

Further, in the seismic isolation device 10, the sliding member 14 rolls on the lower plate 11a of the base plate member 11 in an arbitrary direction to isolate the seismic isolation. Therefore, in order to ensure the seismic isolation effect, the base plate member 11 itself is rubbed. It is preferable to use a low member or to mount the friction reducing member on the lower plate 11a so that the rolling friction can be reduced and the vehicle can roll smoothly.
As the friction reducing member, for example, an acrylic resin material or a fluorine-based resin material such as PTFE (polytetrafluoroethylene) has a low coefficient of friction and is most preferable, but polyethylene or another material having a low coefficient of friction can also be used. Further, the friction reducing member may be provided with irregularities even if it has a flat flat shape so that the contact area with the lower plate 11a or the like is reduced with respect to the total area of the lower plate 11a.
Further, the friction reducing member is not limited to the case where a sheet-like material is mounted on the lower plate 11a, and the friction reducing member can also be obtained by applying the above material on the lower plate 11a.
In this case, when a friction reducing member is provided on the lower plate 11a and the sliding member 14 is rolled in an arbitrary direction, if the friction with the friction reducing member is too small, the sliding member 14 rolls. You will slip without doing it, and you will not be able to obtain the effect of rolling.
Therefore, in the case of rolling seismic isolation using the rolling member 14, there is an appropriate range of friction, and for example, the surface roughness (Ra) is preferably 0.01 to 0.1 μm.
Further, the base plate member 11 including the friction reducing member needs to have a hardness that allows the sliding member 14 and the like to smoothly roll even when a load is applied. The hardness of the surface of the base plate member 11 including the friction reducing member varies depending on the size of the sphere of the sliding member 14, but for example, the hardness of Asker A is preferably 50 or more.

In the above embodiment, the spherical rotating body 14a constituting the sliding member 14 attached to both end portions 12b of the loading plate member 12 is seismically isolated by rolling, but the sliding member 14 is used as the rolling member. Instead, it is composed of a sliding member having a low friction surface, and is configured to slide on the lower plate 11a or the friction reducing member of the lower plate 11a so that the sliding surfaces slide together, and seismic isolation is achieved by sliding. You can also do it. Then, in the connection of the elastic member 13, the elastic member 13 is connected between the spring connecting point 16 and the spring connecting point 17 on both ends by shifting the expansion / contraction direction B of the elastic member 13 and the width direction A of the loading plate member 12. It may be configured to connect.
Even when the sliding surfaces of such a sliding member slide and come into surface contact with each other, when they resonate with the natural vibration of the spring, the frequencies of each other are canceled and the vibration can be suppressed from being amplified. it can. Further, by providing sliding members at both ends 12b of the loading plate member 12 to support the load, the loading plate member 12 can always support the load in a stable state. Further, as described above, the seismic isolation device 10 also has effects such as a sufficient range of motion of the loading plate member 12 in addition to the attenuation of the energy of the seismic motion.
Further, when the same range of motion is secured, the seismic isolation device 10 can be miniaturized.

The seismic isolation device of the present invention includes a seismic isolation device 10 composed of a base plate member 11, a loading plate member 12, and an elastic member 13 arranged between them as one unit, and includes a plurality of units. It can be configured as a seismic isolation device. In this seismic isolation device, one load is placed and used on the load plate members 12 of a plurality of units.
For example, when the load is a large rectangular shape, by arranging four units (seismic isolation devices 10) at the four corners of the load, the load can be stably supported and sufficient seismic isolation is provided. The effect is obtained.
The number of units used as the seismic isolation device is not limited to four units, but may be two or more, and may be determined according to the projected area and weight of the load on the plane.

According to the seismic isolation device 10 of the present invention, even if the expansion / contraction direction B of some elastic members 13 and the linear direction A that moves during an earthquake of the loading plate member 12 coincide with each other, the elastic member 13 resonates due to the natural vibration. However, the elastic member 13 can prevent the vibration from being amplified, the loading plate member 12 can be returned to the origin, and the energy due to the earthquake can be attenuated.
In addition, since the elastic member 13 is not arranged in the width direction A of the loading plate member 12, even if the moving direction of the loading plate member 12 is the width direction A of the loading plate member 12, the expansion / contraction direction of the elastic member 13 Since it does not match B, it is possible to suppress the amplification of vibration. Therefore, even in a rectangular seismic isolation device that is vulnerable to vibration in the width direction, the risk of the loaded load falling can be reduced.
Further, since the sliding member 14 is arranged near the second connecting point (spring connecting point) 17 or outside the second connecting point (spring connecting point) 17, the load is always in a stable state. It can support a load and can be rolled or slid in a stable state.

According to the seismic isolation device 10 of the present invention, the seismic isolation device 10 is provided as one unit, and one load can be placed on the load plate members 12 of a plurality of units. Even if it is large, it can be stably supported. Further, by changing the number of units, the degree of freedom with respect to the size and weight of the load can be increased.

In the above embodiment, the tension coil spring has been described as an example of the elastic member 13, but the present invention is not limited to this, and a member having elasticity such as rubber or synthetic resin foam can also be used.

10 Seismic isolation device 11 Base plate member 11a Lower plate 11b Strut 12 Loading plate member 12a Loading plate 12b Both ends 13 Elastic member (tension coil spring)
13a One end connecting part 13b The other end connecting part 14 Sliding member 14a Spherical rotating body 14b Support frame 16 First spring connecting point (first connecting point)
17 Second spring connection point (second connection point)
A Width direction of loading plate member B Expansion and contraction direction (mounting direction of elastic member)
C Direction of earthquake motion

Claims (2)

The load plate member is movably installed on the base plate member via the sliding member.
A seismic isolation device including a plurality of elastic members that connect the base plate member and the load plate member described above.
A strut portion is provided at the center of the base plate member in the width direction.
The sliding members are arranged at both ends in the width direction of the load plate member described above.
The elastic member connects the strut portion and the sliding member.
Without matching the width direction of the load plate member described above,
Further, the seismic isolation is characterized in that the strut portion is provided so as to be located between the sliding members at both ends in the stationary state, and the sliding member is provided on the strut portion. Seismic isolation device. The strut portion has a plurality of spring connection points, and the spring connection points
The vibration isolation device according to claim 1, wherein one end connecting portions of two elastic members are connected to each other.

Images