JP4754393B2 - Seismic isolation table - Google Patents

Description

  The present invention places one or more seismic isolation objects such as precision instruments such as electronic computers and precious displays such as arts and crafts, and is installed at other positions on the floor of the building to prevent earthquakes. The present invention relates to a seismic isolation table for attenuating shaking and protecting the seismic isolation object from an earthquake.

There are numerous proposals for this type of seismic isolation table.
The first is at least two arc-shaped X-rails that are fixed to the bottom plate on the foundation and have a low center and high both ends, and a direction that is fixed to the bottom surface of the top plate above the X-rail and is orthogonal to the X-rail. And at least two arc-shaped Y rails having a high center and a low end, a lower part sandwiching the X rail, an upper part sandwiching the Y rail, and a conical block provided at the center, an end of the X rail and the Y A shock absorber disposed at an end of the rail; and a recess for receiving and fixing a support leg which is fixed to the lower surface of the seismic isolation object and protrudes downward on the upper surface plate, and has a plurality of through holes in the upper surface plate. This is a low-floor seismic isolation device for a display case (Patent Document 1) that is open and further has a friction damper disposed at the center between the upper surface plate and the lower surface plate.

  This seismic isolation device seems to be a reliable operation with a relatively low floor, but the configuration of the intersecting X and Y rails and the connecting blocks is complicated, and it cannot necessarily be said to be a simple mechanism.

  The second is a fixed frame, a movable frame provided in parallel with the fixed frame above the fixed frame, an arc shape having a predetermined curvature and a convex side fixed downward on the inner wall surface of the fixed frame. A curved rail, a second curved rail having an arc shape with a predetermined curvature and a convex side fixed upward on the inner wall surface of the movable frame so as to be orthogonal to the first curved rail, and moving along the first curved rail A movable first slide block, a second slide block movable along the second curved rail, and a universal joint connecting the first slide block and the second slide block, the universal joint having This is a seismic isolation table (Patent Document 2) in which spherical bearings are used for either one of rotor shafts that intersect each other.

  This seismic isolation table is similar to that of Patent Document 1. However, the fixed frame is shaken by the earthquake on the slide block, the movable frame added to the slide block, the table fixed thereto, and the article placed thereon. As a result, the amplitude of the movable frame transmitted through the slide block is smaller than that of the fixed frame due to the inertia due to the inertia of the load, and a friction damper such as that of Patent Document 1 is used. Or a similar means is not adopted. The buffer or the like is not employed. To that extent, the seismic isolation table of Patent Document 2 is simpler, but the configuration of the first and second curved rails, the first and second slide blocks arranged on these, and the universal joint connecting them is complicated. It is not necessarily a simple mechanism.

  No. 3 is a seismic isolation device that ejects compressed air to levitate the seismic isolation table, wherein an air ejection mechanism is attached to the lower surface of the seismic isolation table, and the air ejection receiving surface is the upper surface of the air supply device housing box. The air supply device includes a pressure air tank that stores pressure air, an electromagnetic valve that supplies and shuts off the pressure air, a regulator that adjusts the pressure of the pressure air, and a connection between them. It is a thing provided with the control part containing the vibration sensor which detects an air piping and an earthquake, and operates this air ejection mechanism.

  This seismic isolation device detects a P wave that is a sign of an earthquake, and when the output value exceeds a predetermined level, an electromagnetic valve opens and compressed air is sent from the pressurized air tank to the air ejection section. The base-isolated table is blown up from the surface, and the base-isolated table is lifted from the surface. It is a thing.

  However, as described above, this seismic isolation device has a large mechanism and cannot be said to be simple. In addition, the thickness of the apparatus becomes too large, and it is difficult to say that the apparatus is suitable for use in the display of art works as described above or installation of electronic computers.

  Part 4 is a seismic isolation device having an air ejection mechanism in which the air ejection surface is in contact with the lower surface of the seismic isolation pad and air is ejected at multiple points by ejecting pressurized air. Place a spherical roller on the upper surface of the seismic isolation pad with a concave spherical surface on the upper surface, and place an isolation table with a concave spherical surface on the upper surface, and place the seismic isolation pad on the spherical core of the spherical roller. This is a seismic isolation device (Patent Document 4) that can freely tilt as an axis so as to make good contact with the mating surface with the air ejection surface.

  This seismic isolation device has basically the same configuration as the seismic isolation device of Patent Document 3, but if the configuration of the pressure air tank or regulator of the air ejection mechanism is not arranged below the table, There is a problem that requires a separate installation space.

  No. 5 is arranged such that the X-direction rail and the Y-direction rail are orthogonally overlapped on the horizontally arranged foundation, and can be moved relative to each other in the length direction thereof, and on that, This is a seismic isolation device (Patent Document 5) in which a seismic isolation stage having a saucer having a concave smooth surface is placed on the lower part, and a restoration guide device that pushes up the concave surface of the saucer vertically on a foundation.

  This seismic isolation device is based on the same idea as in Patent Documents 1 and 2, but the X-direction rail and the Y-direction rail are linear, which is slightly simpler in that respect. However, these also require linear orbit bearings disposed between them, and their configuration is not always simple.

Japanese Patent Application Laid-Open No. 11-166591 JP 2004-278704 A JP 2001-208131 A JP 2001-108209 A JP-A-11-273593

  The present invention solves the above-mentioned problems of the prior art and can be configured in a simple and low-floor type, and can appropriately secure a damping force of vibration caused by an earthquake in a wide acceleration range and over a long period of time. The problem to be solved is to provide a seismic isolation table that can avoid unnecessary movement of the table in the rotating direction.

1 of the present invention is a top plate and a substrate facing up and down in a stationary state, and a load disk disposed in a positional relationship facing the top plate and the substrate in the stationary state, and the facing surfaces are respectively A plurality of load disks configured in a concave shape and a spherical support that is arranged between each of the load disks facing each other so as to be able to roll one by one, all of them between the facing faces of the corresponding load disks A spherical support that is held by a cage to roll together, an outer joint portion at the edge of the substrate, a central joint portion at the cage, and an inner joint portion at the ceiling. It is a seismic isolation table comprising a pair of lazy tong mechanisms respectively coupled to the plates and arranged in a stationary state so that they are in series with each other.
It is.

According to a second aspect of the present invention, in the seismic isolation table according to the first aspect of the present invention, the cage includes a holding plate that can cover a region where each of the spherical supports is located, and each of the spherical supports of the holding plate. A ball holding portion configured at a position corresponding to the position of the cylindrical supportable portion of the spherical support, an upper tapered portion extending from the upper end thereof, and an open spherical support opened at the upper end thereof. The ball holding portion is provided with an upper opening capable of projecting the upper portion, and a friction material in contact with the spherical support, which is provided on the inner surface of the upper narrow taper portion.

  A third aspect of the present invention is the damper mechanism provided in the lower part of the top plate or the upper part of the substrate in the seismic isolation table of the first aspect of the invention, which is caused by friction generated between the facing substrate or the top plate. A damper mechanism for absorbing horizontal vibration relative to the substrate of the top plate is added.

  4 of the present invention is the seismic isolation table of 3 of the present invention, wherein the damper mechanism is a cylindrical mechanism main body fixed to the lower part of the top plate, and the friction that is arranged in the mechanism main body so as to be movable up and down. A friction member whose lower end is in contact with the substrate, and a cylinder upper portion of the mechanism main body and an upper portion of the friction member, and biases the friction member in a downward direction. It consists of a spring member.

  According to the fifth aspect of the present invention, in the seismic isolation table according to the first, second, third, or fourth aspect of the present invention, the space between the outer peripheral edge of the top plate and the outer peripheral edge of the substrate is covered with a cover material. .

  According to the seismic isolation table 1 of the present invention, it is possible to satisfactorily attenuate seismic vibrations, but the configuration is simple, so that the thickness of the device can be reduced. Therefore, when displaying arts and crafts at museums, etc., or installing electronic computers at companies, etc., even if they are placed on them, their height does not increase unnecessarily. Space can be used effectively.

  In addition, the top plate moved to the position deviated from the origin due to the horizontal seismic vibration applied to the substrate is a concave load disk arranged in a face-to-face state between this and the spherical plate arranged so as to be able to roll between them. By the action of the support body, it is always possible to return to the origin before the stationary state. The horizontal vibration component in the earthquake is absorbed and damped by the friction loss between the spherical support and the cage. Since this damping is caused by friction, a constant damping force without fluctuation can be secured in a wide acceleration range due to an earthquake. Further, the vibration component in the vertical direction can be absorbed by configuring the load disk with elasticity.

  Further, as described above, since the substrate, the retainer, and the top plate are coupled by the lazy tong mechanism, the top plate can be freely moved within a certain range in the horizontal direction, but rotates unnecessarily. There is no risk of such problems.

  According to the seismic isolation table 2 of the present invention, since the structure of the cage is simple and the holding operation is reliable, the operation of returning the origin of the top plate and the like is also ensured. Also, in this case, the rolling motion of the spherical support is suppressed by friction with the friction material disposed on the inner surface of the thin taper portion that abuts against the exterior state, thereby attenuating the horizontal component of the earthquake. Become.

  According to the seismic isolation table 3 of the present invention, since a friction damper is added as a damper mechanism for attenuating the vibration of the earthquake, the convergence of the vibration can be accelerated, and in this case, naturally, the fluctuation occurs in a wide acceleration range due to the earthquake. It is possible to ensure a constant damping force without any noise. Moreover, this friction damper can also attenuate a vibration component in the vertical direction of an earthquake by arranging a vertical elastic member on the friction damper.

  According to the seismic isolation table 4 of the present invention, the damper mechanism is simple and has an effective configuration capable of accelerating the convergence of the vibration due to the earthquake. Needless to say, a constant damping force without fluctuation can be secured in a wide acceleration range due to an earthquake. The friction damper can satisfactorily attenuate the vertical vibration component of the seismic vibration by the action of the spring member acting in the vertical direction.

  According to the seismic isolation table 5 of the present invention, since the space between the outer peripheral edge of the top plate and the outer peripheral edge of the substrate is covered with the cover material, there is a possibility that dust and other foreign matters may enter during this period even when used for a long time. There is no. Therefore, the initial high seismic isolation performance can be maintained over a long period of time.

  The present invention basically includes a top plate and a substrate facing up and down in a stationary state, a load disk disposed in a face-to-face state on the top plate and the substrate, and a spherical support disposed between the load disks facing each other. , A seismic isolation table comprising a substrate, a cage for holding the spherical support, and a pair of lazy tong mechanisms coupled to the top plate in a predetermined relationship.

  The top plate is a plate material for a table on which the seismic isolation object is placed, and is also a member constituting the frame of the apparatus. Therefore, it can be composed of a plate material having an appropriate strength suitable for it. A metal plate having a substantially square shape when viewed from the plane is appropriate.

  The substrate is a member for arranging the apparatus in such a manner that the apparatus is placed directly on the floor of the building or other installation location, and is also a member constituting the frame of the apparatus facing the top plate. Therefore, similarly to the top plate, the top plate can be made of a plate material having appropriate strength. Similarly to the top plate, a substantially square metal plate material is suitable as viewed from above, and it is preferable that the top plate has the same dimensions.

  The load disk is arranged in a face-to-face state on a top plate and a substrate that are in a face-to-face state. Naturally, the top plate is attached to the lower surface thereof downward, and the substrate is attached to the upper surface upward. Each load disk is formed in a concave shape with a recessed center. A concave spherical shape is appropriate. This load disc is expected to have a function of returning to the origin of the top plate that has been moved to a state where it does not coincide with the substrate due to seismic vibration in combination with a spherical support placed between a pair of upper and lower pairs. Yes, the concave shape is set from such a viewpoint. In addition, this load disk is also expected to have an action of absorbing earthquake vibrations in the vertical direction. From such a viewpoint, the load disk is suitable for absorbing the vertical pressure applied thereto. Should be configured to be elastic. Alternatively, a member having some elasticity should be combined with this.

  It is appropriate to provide three or more sets of these load disks, with one pair facing each other in the vertical direction. It is appropriate that the load disks of each set are arranged on an arc of a circle centering on the center of the top plate and the substrate at an angular interval divided by the number of sets. Therefore, for example, when three sets are arranged, the angular interval is 120 degrees, and when four sets are arranged, the angular intervals are 90 degrees.

  In addition to the above functions, these load disks transmit the load of the seismic isolation target on the top plate to the board via the spherical support between them, and while damping the seismic vibration applied to the board, It is also a thing conveyed to a top plate via a spherical support. Therefore, it is necessary to be composed of a member having sufficient strength without inconvenience to fulfill its function. It is appropriate to be composed of metals. The diameter is determined in consideration of the maximum amplitude of earthquake vibration.

  The spherical supports are arranged so as to be able to roll one by one between each set of load disks, the load receiving function acting together with the load disks, the damping transmission function of seismic vibration, and the origin of the top plate Since it is a thing which should perform a return function, the intensity | strength and diameter are appropriately determined from such a viewpoint. Usually, it is appropriate to use a metal ball.

  As described above, since three or more pairs of the spherical supports are disposed between the load disks that are suitable for installation, three or more are disposed in a positional relationship between the load disks of each group. In other words, these spherical supports should always maintain their mutual positional relationship even when rolling in response to earthquake vibration. Therefore, the spherical supports are held in the above mutual positional relationship by the cage, and can be rolled between the corresponding load disks in a synchronized state when subjected to earthquake vibration.

The retainer is basically not limited to a specific configuration as long as it can perform the above functions. For example, the cage is constituted by a holding plate that can cover a region where each spherical support is located, and a ball holding portion that is configured at a position corresponding to the position of each spherical support on the holding plate. Can do. Instead of this, it is also possible to employ a frame member having a configuration in which a ball holding portion can be arranged at a position where each of the spherical supports is located. Further, the ball holding portion needs to be able to hold the spherical support in a freely rollable state, but if so, this is not limited to a specific configuration. For example, the ball holding portion is configured such that the cylindrical portion into which the spherical support can be inserted, the upper tapered portion extending from the upper end thereof, and the upper portion of the inserted spherical support can be projected at the upper end thereof. It can comprise with the opened top opening.

  When the ball holding portion of the cage is configured as described above, the friction loss at the contact portion between the thin taper portion and the spherical support is utilized for convergence of the vibration operation of the top plate due to seismic vibration. be able to. The friction loss between the spherical support that absorbs the horizontal vibration component described above and the cage is, in this case, the friction loss between the upper taper portion of the cage and the spherical support. become. Further, a friction material can be applied to the inner surface of the above-mentioned narrow taper portion so that a larger friction loss can be generated.

  The lazy tongs mechanism is a general structure constructed by connecting links, and the outermost joint part is the edge of the substrate, the central joint part is the cage, and the innermost joint. The parts are respectively coupled to the top plate. This lazy tong mechanism uses a pair, so that the apparatus is in a stationary state, so that they are in series with each other, and symmetric about an imaginary line arranged orthogonally in the center between their inner ends. To arrange.

  The lazy tong mechanism is a thing that regulates the movement in the rotational direction while allowing free horizontal vibration (swing) of the top plate relative to the substrate. Make up what you have. Usually, a metal link is to be configured by pin-coupling so as to be rotatable. The allowable movement range for the top plate and the cage is determined in consideration of the maximum amplitude of the seismic vibration.

  The seismic isolation table of the present invention can further be provided with a damper mechanism between the top plate and the substrate. For example, the damper mechanism is attached to the lower portion of the top plate or the upper portion of the substrate, and the horizontal vibration of the top plate relative to the substrate is caused by the friction generated between the facing plate or the top plate. Means to absorb. In particular, it works to accelerate the convergence of vibration. Also, by including a spring member acting in the vertical direction in the configuration, it should also serve as a means for absorbing vertical vibration in seismic vibration.

  The damper mechanism is not limited to a specific configuration as long as it has the basic configuration as described above and can exhibit the functions as described above. For example, the damper mechanism includes a cylindrical mechanism main body fixed to a lower portion of the top plate, a friction member arranged to be movable up and down in the mechanism main body, a cylinder upper portion of the mechanism main body, and an upper portion of the friction member And a spring member that urges the friction member in the downward direction. The friction member is disposed such that the lower end thereof is in contact with the substrate.

  The spring member determines an appropriate pressure for the friction member to contact the substrate, and, in the event of an earthquake, applies braking due to sliding friction loss to the relative vibration operation in the horizontal direction of the top plate with respect to the substrate. Try to attenuate. Alternatively, the vertical component of the seismic vibration is absorbed by its elasticity to attenuate it.

  In addition, the seismic isolation table of the present invention covers the space between the outer peripheral edge of the top plate and the outer peripheral edge of the substrate with a cover material, and prevents dust and other foreign substances from entering the internal mechanism. It is preferable to avoid it. As the cover material, it is possible to freely employ various materials that can satisfy such a purpose. For example, as the cover material, various natural materials or cloth materials made of chemical fibers can be adopted. Such a cover material is attached with a margin in consideration of the maximum horizontal movement distance of the top plate relative to the substrate. Or it shall have the elasticity which can respond.

  Therefore, according to the seismic isolation table of the present invention, it is possible to satisfactorily attenuate the horizontal component and the vertical component of the seismic vibration. The friction damper action between the spherical support and the cage for damping the horizontal component is as described above, and the damping of the vertical vibration using the elasticity of the load disk is also described above. Street. Further, the configuration between the top plate and the substrate of the apparatus is compact, and the thickness of the entire apparatus can be reduced. Therefore, since the installation space in the height direction is not consumed unnecessarily, the installation area for seismic isolation can be widened, and the installation space can be effectively used.

  Also, the top plate moved to a position deviated from the origin by the horizontal vibration operation relative to the substrate due to the earthquake is a concave load disk arranged in a face-to-face state between this and the substrate, and further rolled between them. By the action of the spherical support freely arranged, it is possible to surely return to the origin before the stationary state.

  Further, as described above, since the substrate, the retainer, and the top plate are coupled by the lazy tong mechanism, the top plate rotates unnecessarily while ensuring free movement in a certain range in the horizontal direction. Will not cause any problems.

  When the damper mechanism is added to the seismic isolation table of the present invention, as described above, this is configured as a friction damper that attenuates the horizontal vibration of the earthquake. The damping force can be secured. Further, as described above, when the spring member acting in the vertical direction is arranged in the damper mechanism, the vibration component in the vertical direction of the earthquake can be absorbed.

  When a cover material is disposed between the outer peripheral edge of the top plate and the outer peripheral edge of the base plate of the seismic isolation table of the present invention, there is no possibility that dust or other foreign matters may enter during this period even when used for a long time. Therefore, the initial high seismic isolation performance can be maintained over a long period of time.

  As shown in FIGS. 1 to 4, the seismic isolation table of this embodiment is basically arranged in a facing state on the top plate 1 and the substrate 2 facing up and down in a stationary state, and the top plate 1 and the substrate 2. Four pairs of load disks 3a, 3b, 3a, 3b ..., a spherical support 4 disposed between the load disks 3a, 3b, 3a, 3b ... facing each other, and all spherical supports 4, 4, ... A pair of lazy tong mechanisms 6, 6 coupled to the substrate 2, the retainer 5 and the top plate 1 in a predetermined relationship, respectively, the top plate 1 and the top plate 1 The damper mechanism 7 is disposed between the substrates 2, and the cover member 8 is disposed between the outer periphery of the top plate 1 and the outer periphery of the substrate 2.

  The top plate 1 is a plate material that constitutes a table on which the seismic isolation object is placed, and as shown in FIGS. 1 and 5, the top plate 1 is made of a square metal plate material as viewed from above. As shown in FIGS. 4 and 6, a side plate is formed in a suspended state on the outer periphery of the top plate 1.

  The substrate 2 is a plate-like member for arranging the device in a form to be placed directly on the floor of the building or other installation place, and as shown in FIG. The metal plate material is configured to have the same dimensions as the top plate 1. As shown in FIGS. 4 and 6, a side plate is formed upright on the outer periphery of the substrate 2.

  Each one of the facing load disks 3a, 3b, 3a, 3b... Is attached to the top plate 1 and the other is attached to the substrate 2 in a positional relationship where they face each other. In this embodiment, as described above, four pairs are employed, and are attached to the four corners as shown in FIGS. 2 to 6 (centering on the top plate 1 and the center of the substrate 2). And an angular interval of 90 degrees along the virtual arc). Of course, the top plate 1 is attached to the lower surface thereof downward, and the substrate 2 is attached to the upper surface upward.

  Each of the load disks 3a, 3b, 3a, 3b,... Is configured in a concave spherical shape with a recessed center, as shown in FIGS. The diameter corresponds to the maximum amplitude of the seismic vibration, and the diameters of the load disks 3a, 3b, 3a, 3b. The load disks 3a, 3b, 3a, 3b,... Are made of metal in order to ensure the necessary strength. Further, each of the load disks 3a, 3b, 3a, 3b... Is loaded with a disc spring (not shown) on the bottom side so as to absorb the seismic vibration component in the vertical direction.

  As shown in FIGS. 2, 4, and 6, the spherical support 4 is disposed between the pair of load disks 3 a and 3 b so as to be capable of rolling one by one. These spherical supports 4, 4... Are constituted by metal balls having a diameter of about 1/4 of the diameter of the load disks 3 a, 3 b, 3 a, 3 b. These spherical supports 4, 4... Are positioned at the center of each of the load disks 3a, 3b, 3a, 3b,. Hold in the mutual positional relationship of the case.

  As shown in FIG. 3, the cage 5 has approximately four sides of a size that can include the centers of the four load disks 3a, 3a,..., 3b, 3b. A holding plate 5a, which is a shaped metal plate material, and ball holding portions 5b, 5b... Formed at the four corners of the holding plate 5a. A damper avoidance opening 5c having the same diameter as that of the load disks 3a, 3a,..., 3b, 3b. Further, the ball holding portions 5b, 5b,... At the four corners of the holding plate 5a are positioned in the center of the load disks 3a, 3b, 3a, 3b,. 4... Should be set so that the positional relationship can be maintained.

  The ball holding portions 5b, 5b, as shown in FIGS. 2 to 6, are a cylindrical portion 5b1 into which the spherical support 4 can be slidably loaded, and an upper tapered portion 5b2 extending from the upper end thereof, The upper opening 5b3 is open at the upper end. A resin friction material (not shown) is affixed to the inner surface of the upper taper portion 5b2, and the friction loss with the spherical support 4 in contact with the friction material is appropriately adjusted. The upper opening 5b3 has a diameter set so that the upper part of the spherical support 4 can protrude as shown in FIG.

  As shown in FIGS. 3 and 5, the lazy tong mechanisms 6 and 6 are configured by connecting two long belt-like links and four belt-like links about half the length by pin members. 2 to 6, the pin member 6 a of the outermost joint part is provided on the upper surface edge of the substrate 2, and the pin member 6 b of the central joint part is provided on the holding plate of the cage 5. The pin member 6c of the innermost joint portion is coupled to the lower surface of the top plate 1 respectively. As shown in FIG. 3, these lazy tong mechanisms 6 and 6 are provided with an imaginary line arranged in a state of being perpendicular to each other in the center between their inner ends in the stationary state of the apparatus. It is arranged so as to be symmetric as a symmetry axis.

  As shown in FIGS. 3, 4, 5, and 6, the pin member 6 a of the joint portion at the outermost end is coupled to the central portion of the corresponding side among the upper surface edge portions of the substrate 2. As shown in FIGS. 3 and 5, the pin member 6 b of the central joint portion is located on the side close to the side connected to the pin member 6 a of the substrate 2 in the entire region of the holding plate 5 a of the cage 5. Join to the top center of the side. Further, as shown in FIGS. 3 and 4, the pin member 6 c of the innermost joint portion is connected to the pin member 6 b of the cage 5 on the lower surface of the top plate 1 that is in a stationary state facing the substrate 2. It couple | bonds with the site | part which faces the edge of the avoidance opening 5c which adjoins the couple | bonded edge | side.

  As shown in FIG. 4, the damper mechanism 7 includes a cylindrical mechanism body 7b fixed to the lower portion of the top plate 1 via a base material 7a, and can be moved up and down in the mechanism body 7b. And a coil spring (spring member) 7d for urging the friction plunger 7c in the downward direction.

  As shown in the figure, the friction plunger 7c is formed with a spring hole 7c1 opened in the upper part in the main body, and the friction part 7c2 is suspended in the lower part of the main body. The coil spring 7d is inserted into the spring hole 7c1, its lower end is brought into contact with the bottom of the spring hole 7c1, and its upper end is placed on the lower surface of the base material 7a constituting the inner upper surface of the mechanism body 7b. This causes the friction plunger 7c to be urged downward. The coil spring 7d determines the strength of the spring from the viewpoint of bringing the friction portion 7c2 of the friction plunger 7b into contact with the upper surface of the substrate 2 with a predetermined pressure and absorbing the vertical component of the seismic vibration.

  The cover material 8 is disposed in a state of connecting the lower end of the outer peripheral side plate of the top plate 1 and the upper end of the outer peripheral side plate of the substrate 2. Covering means for shielding the components between the top plate 1 and the substrate 2 from the outside, and a cloth material having a slight stretchability can allow relative vibration of the top plate 1 with respect to the substrate 2. It is configured to have a margin.

  Therefore, according to the seismic isolation table of this embodiment, the vertical and horizontal components of the seismic vibration can be satisfactorily attenuated. If it is placed and installed at a predetermined position, it is possible to satisfactorily protect the artwork and computer from earthquake vibration.

  In a stationary state without an earthquake, as shown in FIGS. 2 to 4, the top plate 1 and the substrate 2 are completely in a face-to-face state. When an earthquake occurs and is transmitted to the substrate 1, the substrate 1 vibrates in the horizontal direction according to the horizontal component, but the top plate 1 and the seismic isolation object placed on the substrate 1 are inertial. By this, it tries to keep a stationary state. For this reason, rolling action occurs on the spherical supports 4, 4... Arranged between the top plate 1 and the substrate 2 through the load disks 3 a, 3 b, 3 a, 3 b. The state is about to be retained. This can be regarded as a vibration due to the earthquake of the top plate 1 on the substrate 2, and the amplitude of the top plate 1 and the cage 5 is increased more than necessary. The friction loss between the inner surface of the tapered portion 5b2 and the friction material and the frictional action of the damper mechanism 7 on the substrate 2 are suppressed. This also attenuates the horizontal acceleration.

  As shown in FIG. 4, in the damper mechanism 7, the friction portion 7c2 of the friction plunger 7c is in contact with the upper surface of the substrate 2 with an appropriate pressure applied by the coil spring 7d. The relative vibration operation with respect to will reduce its amplitude. Such a damping action against seismic vibration is ensured by the friction damper as described above, and therefore does not change in a wide acceleration range due to the earthquake. The same applies to the friction loss between the spherical support 4 and the friction material on the inner surface of the tapered taper portion 5b2 of the cage 5.

The seismic isolation table produced in this example was tested as follows, and the results shown below were obtained for each.
When a 1000 kg weight was placed on the top board 1 and vibration was applied to the substrate 1 along the installation direction (X direction) of the lazy tong mechanism 6, a maximum response acceleration of 75Gal was obtained with a maximum input acceleration of 812Gal. In this case, the value of maximum response acceleration (B) / maximum input acceleration (A) is about 0.09.
When vibration was applied to the substrate 1 along the Y direction orthogonal to the X direction under the same conditions, a maximum response acceleration of 74 Gal was obtained with a maximum input acceleration of 582 Gal. In this case, the value of maximum response acceleration (B) / maximum input acceleration (A) is about 0.13.

When a weight of 750 kg was placed on the top board 1 and vibration was applied to the substrate 1 along the X direction, a maximum response acceleration of 103 Gal was obtained with a maximum input acceleration of 801 Gal. In this case, the value of maximum response acceleration (B) / maximum input acceleration (A) is about 0.13.
When vibration was applied to the substrate 1 side along the Y direction under the same conditions, a maximum response acceleration 87 Gal was obtained with a maximum input acceleration 594 Gal. In this case, the value of maximum response acceleration (B) / maximum input acceleration (A) is about 0.15.

From the above results, it can be seen that the response acceleration ratio obtained by the seismic isolation table of this embodiment is about 10% of the input acceleration.
From the results of many tests performed separately from the above, the response acceleration ratio tends to increase as the load on the top plate 1 increases. The response acceleration ratio, which was about 0.14 when tested with a 1000 kg weight, is about 0.08 when tested with a 100 kg weight under the same conditions.
Further, the response acceleration ratio tends to increase as the input acceleration decreases.

  Further, the top plate 1 moved to a position shifted from the origin by the horizontal vibration operation relative to the substrate 2 due to the earthquake as described above is a load disk 3a arranged in a facing state between the top plate 1 and the substrate 2. By the action of 3b, 3a, 3b... And the spherical supports 4, 4,.

  Further, as described above, since the substrate 2, the holding plate 5a of the cage 5, and the top plate 1 are coupled by the lazy tong mechanisms 6 and 6, the top plate 1 is shown in FIGS. In addition, there is no problem of unnecessary rotation while ensuring free movement within a certain range in the horizontal direction. In the figure, an example of movement by vibration in a direction in which the lazy tong mechanisms 6 and 6 expand and contract in a series state is shown. According to the lazy tong mechanisms 6 and 6, the top plate 1 Movement in the direction perpendicular to the axis and in all other directions is likewise permitted, while being kept from rotating.

  The vertical component of the seismic vibration is absorbed by the elasticity of the disc springs inserted in the bottoms of the load disks 3a, 3b, 3a, 3b... And further absorbed by the elasticity of the coil springs 7d of the damper mechanism 7. The

  As described above, since the components arranged between the top plate 1 and the substrate 2 are compact, the space between them can be narrowed, and the height of the apparatus can be reduced. Therefore, the installation space in the height direction is not consumed unnecessarily, the installation area for seismic isolation can be widened, and the installation space can be effectively used.

  Even when this seismic isolation table is used over a long period of time by the cover material 8, the load disks 3a, 3b, 3a, 3b..., The spherical supports 4, 4. 5. There is no possibility that dust or other foreign matter may enter the lazy tong mechanisms 6 and 6 and the damper mechanism 7. Therefore, the initial high seismic isolation performance can be maintained over a long period of time.

The top view of the stationary state of the seismic isolation table of an Example. The front view of the stationary state of the seismic isolation table of an Example. The top view of the stationary state of the seismic isolation table which removed the top plate. Cross-sectional explanatory drawing of the stationary state of the seismic isolation table of an Example. The top view of the maximum displacement state of the seismic isolation table which removed the top plate. Sectional explanatory drawing of the maximum displacement state of the seismic isolation table which removed the top plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top plate 2 Board | substrate 3a, 3b Load disc 4 Spherical support body 5 Cage 5a Holding plate 5b Ball holding part 5b1 Cylindrical part 5b2 Upper taper part 5b3 Upper opening 5c Avoidance opening 6 Lazy tong mechanism 6a of outermost joint part Pin member 6b Pin member 6c at the center joint portion Pin member 6c at the innermost end joint portion 7 Damper mechanism 7a Base material 7b Mechanism body 7c Friction plunger (friction member)
7c1 Spring hole 7c2 Friction part 7d Coil spring (spring member)
8 Cover material

Claims (5)

A top plate and a substrate facing up and down in a stationary state;
A load disk arranged in a positional relationship facing the top plate and the substrate in the stationary state, and a plurality of load disks each configured to have a concave surface.
A spherical support that is arranged so as to be able to roll one by one between the facing load disks, each of which is a cage that rolls together between the facing faces of the corresponding load disks. A held spherical support;
A pair of lazy tong mechanisms in which the joint portion at the outer end is connected to the edge of the substrate, the joint portion at the center is connected to the cage, and the joint portion at the inner end is connected to the top plate. A pair of lazy tong mechanisms arranged to be
Seismic isolation table composed of The cage,
A holding plate capable of covering a region where each of the spherical supports is located;
A ball holding portion configured at a position corresponding to the position of each spherical support of the holding plate, a cylindrical portion into which the spherical support can be inserted, an upper tapered portion extending from the upper end thereof, and an upper end thereof A ball holding part having an upper opening that can project the upper part of the opened spherical support that has been opened,
A friction material in contact with the spherical support, applied to the inner surface of the upper taper portion;
The seismic isolation table according to claim 1, comprising:   A damper mechanism provided at a lower portion of the top plate or an upper portion of the substrate, wherein the damper absorbs a relative horizontal vibration of the top plate with respect to the substrate by friction generated between the facing substrate or the top plate. The seismic isolation table according to claim 1 to which a mechanism is added. The damper mechanism,
A cylindrical mechanism body fixed to the bottom of the top plate;
A friction member disposed in the mechanism main body so as to be movable up and down, and a friction member whose lower end is in contact with the substrate;
A spring member arranged between the cylinder upper part of the mechanism main body and the upper part of the friction member to urge the friction member in a downward direction;
The seismic isolation table according to claim 3 comprising:   The seismic isolation table according to claim 1, wherein the space between the outer peripheral edge of the top plate and the outer peripheral edge of the substrate is covered with a cover material.

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