Seismic isolation plate

Abstract

The seismic isolation device has a simple structure and can be made lightweight. [Solution] The seismic isolation plate 10 comprises a fixed plate 12 which has multiple rows of fixed ribs 12A formed on its top and is installed with its bottom surface in contact with the floor surface G, and a sliding plate 14 which has multiple rows of sliding ribs 14A formed on its bottom in a direction intersecting the fixed ribs 12A, and is placed with its bottom surface in contact with the upper surface of the fixed ribs 12A, and the object to be seismically isolated 20 is placed on the upper surface of the sliding ribs 14A.

Description

Technical Field

[0001] The present invention relates to a seismic isolation plate.

Background Art

[0002] Conventionally, a seismic isolation device such as Patent Document 1 has been known. In Patent Document 1, a support device having an upper plate and a lower plate, each having a flat plate-shaped sliding material attached to one surface of a flat plate-shaped main body plate surface, and a biasing member such as rubber for integrally binding the upper plate and the lower plate is disclosed. The upper plate and the lower plate are overlapped in a state where the plate surfaces of the sliding materials attached thereto are in contact with each other and can slide relative to each other. A seismic isolation object is placed on the upper surface of the upper plate, and the lower surface of the lower plate contacts the floor surface.

[0003] In Patent Document 1, when vibration such as seismic vibration is externally applied to the support device (seismic isolation device) by reducing the static friction coefficient and the dynamic friction coefficient between the upper plate and the lower plate by the sliding material, the upper plate does not accurately follow the vibration of the lower plate because an inertial force acts, and although the inertial force is reduced by the action of the biasing member, sliding according to the friction coefficient occurs on the lower plate, and the impact of the vibration applied to the upper plate is mitigated. Thus, by providing a sliding mechanism between the upper plate and the lower plate, it is said that the overturning and damage of the seismic isolation object placed on the upper surface of the upper plate are suppressed. Further, after the externally applied vibration has subsided, the positional displacement generated between the lower plate and the upper plate is eliminated by the tensile force of the biasing member and returned to the initially arranged position.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, in order to construct the upper and lower shoes, it is necessary to attach a single flat sliding material to the surface of a single flat main body. This makes the structure of the seismic isolation device complex, resulting in problems of increased burden in manufacturing and repair. Furthermore, since both the upper and lower shoes are made of plate-like members each containing a single flat sliding material, the overall weight of the seismic isolation device tends to be heavy. Increased weight also leads to problems of increased burden in handling.

[0006] The present invention aims to provide a technology that allows for a simple and lightweight structure as a seismic isolation device. [Means for solving the problem]

[0007] A seismic isolation plate according to one aspect of the present invention includes a fixed plate having multiple rows of fixing ribs formed on its top and installed with its bottom surface in contact with the floor surface, and a sliding plate having multiple rows of sliding ribs formed on its bottom in a direction intersecting the fixing ribs, and positioned with the bottom surface of the sliding ribs in contact with the top surface of the fixing ribs, with the object to be seismically isolated placed on the top surface of the sliding ribs. [Effects of the Invention]

[0008] According to the present invention, the structure of the seismic isolation device is simple and lightweight. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view illustrating a seismic isolation plate according to an embodiment of the present invention. [Figure 2] This is a perspective view illustrating another example of the fixing ribs of the seismic isolation plate according to this embodiment. [Figure 3] This is a perspective view illustrating the state in which seismic motion is applied to the seismic isolation plate according to this embodiment. [Figure 4] This is a plan view illustrating a seismic isolation plate according to a first modified example of this embodiment. [Figure 5]This is a cross-sectional view taken along line 5-5 in Figure 4, illustrating the seismic isolation plate according to the first modified example of this embodiment, cut in a plane perpendicular to the floor surface. [Figure 6] This is a cross-sectional view illustrating a seismic isolation plate according to a second modified example of this embodiment, cut in a plane perpendicular to the floor surface. [Figure 7] This is a plan view illustrating the gaps formed by the fixing ribs of the seismic isolation plate according to the second modified example. [Figure 8] This is a side view illustrating another example of a fixing plate for a seismic isolation plate. [Modes for carrying out the invention]

[0010] The present invention will be described below with reference to Figures 1 to 5. Note that the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, the dimensional relationships and ratios of the elements do not necessarily correspond between multiple drawings. Also, unless otherwise specified in the specification, each element is not limited to one, and multiple elements may exist. In addition, substantially identical elements are denoted by the same reference numeral in the drawings, and redundant explanations in the specification are omitted.

[0011] <Seismic isolation plate> First, the seismic isolation plate 10 according to this embodiment will be described with reference to Figures 1 to 3. As shown in Figure 1, the seismic isolation plate 10 according to this embodiment has a fixed plate 12 and a sliding plate 14. The object to be seismically isolated 20 is placed on the upper surface of the sliding plate 14. The object to be seismically isolated 20 can be any item, as long as it is desirable to mitigate the impact of seismic motion that causes tipping, falling, disconnection of wiring, misalignment of parts, etc., such as precision equipment such as a computer server itself, or a shelf with legs on which precision equipment etc. is placed.

[0012] "The object to be seismically isolated is placed on the upper surface of the sliding plate (or sliding rib)" includes both the state in which the object to be seismically isolated is placed directly on the upper surface of the sliding plate, and the state in which the object to be seismically isolated is placed on the upper surface of the sliding plate by placing one or more other members between the sliding plate and the object to be seismically isolated. Other members may be appropriately adopted, for example, members for anti-slip, protective, or joining purposes.

[0013] In this embodiment, both the fixed plate 12 and the sliding plate 14 are made of resin. However, this disclosure is not limited to this, and the materials of the fixed plate and the sliding plate are arbitrary, as long as they can be processed as required, have the required functionality, and have the required strength. Furthermore, this disclosure does not exclude the case in which the fixed plate and the sliding plate are made of different materials.

[0014] (Fixing plate) As shown in Figure 1, the fixing plate 12 in this embodiment is rectangular in plan view, but the disclosure is not limited to this, and the shape in plan view can be arbitrary, for example, circular, elliptical, polygonal, etc. Also, in this embodiment, as shown in Figure 1, the fixing plate 12 is simply placed on the floor surface G with its bottom surface in contact with it, but the disclosure is not limited to this, and a non-slip sheet may be laid between the bottom surface of the fixing plate and the floor surface, or the fixing plate may be fixed to the floor surface using fixing means such as adhesive or bolts.

[0015] The fixing plate 12 has a flat fixing bottom portion 12B and a plurality of fixing ribs 12A positioned above the fixing bottom portion 12B in Figure 1. That is, a plurality of fixing ribs 12A are formed in parallel on the top of the fixing plate 12. In other words, a plurality of rows of fixing ribs 12A are formed on the upper surface of the fixing plate 12. The plurality of fixing ribs 12A extend along one direction (the left-right direction in Figure 1). Adjacent fixing ribs 12A are formed parallel to each other and spaced apart.

[0016] Also, although the fixed bottom 12B according to the present embodiment is in a flat plate shape, in the present disclosure, it is not limited to this. For example, it may be in a mesh shape having a plurality of through holes in the flat portion between ribs. In the present disclosure, the floor surface means not only the indoor floor surface but also all surfaces on which the seismic isolation object is placed, such as the upper surface of the installation table for installing precision equipment, the upper surface of the shelf board of the article storage shelf, etc.

[0017] In the present embodiment, the case where the fixed bottom 12B and the fixed rib 12A are integrally formed is exemplified. However, in the present disclosure, it is not limited to this. For example, after the fixed bottom and the fixed rib are separately formed, the fixed plate may be formed by joining them respectively. The materials of the fixed bottom and the fixed rib may be different from each other.

[0018] The cross-sectional shape of the fixed rib 12A in FIG. 1 is rectangular. However, in the present disclosure, the cross-sectional shape of the fixed rib may be any geometric shape such as triangular, trapezoidal, semi-circular, semi-elliptical, etc. As another example of the present embodiment, for example, as shown in FIG. 2, the upper part of the fixed rib 12A of the fixed plate 12 may be formed such that the width measured along the horizontal direction gradually narrows as it goes toward the upper sliding plate. The smaller the contact area between the fixed rib and the sliding rib, the smaller the mutual friction coefficient. Therefore, by selecting the cross-sectional shape of the fixed rib, the friction coefficient can be adjusted so as to obtain appropriate seismic performance.

[0019] The resin-made fixed plate 12 having a plurality of fixed ribs 12A according to the present embodiment has the plurality of fixed ribs 12A formed in parallel in one direction as shown in FIG. 1. However, in the present disclosure, it is not limited to this. The structure of the fixed rib is arbitrary. For example, a slide plate having rhombic protruding ribs formed on the surface crossing each other as described in Japanese Patent No. 5007463, or a slider board having first protruding ribs formed on the surface crossing each other as described in JP-A-2017-140168 can be adopted.

[0020] (Sliding plate) As shown in Figure 1, the sliding plate 14 of this embodiment is rectangular in plan view, but the disclosure is not limited to this, and the shape in plan view is arbitrary, for example, it may be circular, elliptical, polygonal, etc. When in use, the sliding plate 14 is placed on the upper surface of the fixing rib 12A of the fixing plate 12. The sliding plate 14 has a flat sliding bottom portion 14B and a plurality of sliding ribs 14A arranged below the sliding bottom portion 14B in Figure 1. That is, a plurality of sliding ribs 14A are formed in parallel on the bottom portion of the sliding plate 14. In other words, a plurality of sliding ribs 14A are formed on the bottom portion of the sliding plate 14 in a direction that intersects with the fixing rib 12A when in use.

[0021] As shown in Figure 1, the multiple sliding ribs 14A according to this embodiment extend along a direction intersecting the fixed rib 12A. In addition, multiple adjacent sliding ribs 14A are formed parallel to each other and spaced apart.

[0022] In this embodiment, an example is shown in which the sliding base 14B and the sliding rib 14A are formed integrally. However, this disclosure is not limited to this, and for example, the sliding base and the sliding rib may be formed separately and then joined together to form a sliding plate. Furthermore, the materials of the sliding base and the sliding rib may be different from each other.

[0023] Although the cross-sectional shape of the sliding rib 14A in Figure 1 is rectangular, in this disclosure the cross-sectional shape of the sliding rib may be any geometric shape, such as triangular, trapezoidal, semicircular, or semielliptical. Similar to the case of the fixing rib 12A of the fixing plate 12 in Figure 2, as another example of this embodiment, for example, the lower part of the sliding rib 14A may be formed such that its width, measured horizontally, gradually narrows as it approaches the lower fixing plate 12. Other configurations of the sliding plate 14 and sliding rib 14A according to this embodiment are the same as those of the fixing plate 12 and fixing rib 12A.

[0024] In this embodiment, the spacing between adjacent fixed ribs 12A and adjacent sliding ribs 14A is approximately 5 mm, and the height of the fixed ribs 12A and the height of the sliding ribs 14A are approximately 4 mm. In Figures 1 to 5, the spacing of each rib is schematically shown in a large size for clarity. The thickness of the fixed bottom 12B and the sliding bottom 14B are both approximately 4 mm. However, this disclosure is not limited to these values, and the spacing of the ribs, the height of the ribs, the thickness of the bottom, etc., can all be appropriately set based on the static friction coefficient, dynamic friction coefficient, load design load, etc., required for the application.

[0025] In this embodiment, the outer shape of the fixing plate 12 is larger than that of the sliding plate 14. In other words, the dimensions and shapes of the fixing plate 12 and the sliding plate 14 are set so that when the seismic isolation plate 10 is installed, the outer edge of the fixing plate 12 is generally located outside the outer edge of the sliding plate 14. However, in this disclosure, it is not essential that the outer shape of the fixing plate be larger than that of the sliding plate; the dimensions can be set arbitrarily, and for example, the outer shapes of the fixing plate and the sliding plate may be approximately the same.

[0026] As shown in Figure 3, for example, if a lateral seismic motion E is applied to the seismic isolation plate 10 from one of the lower sides of the rectangular fixed plate 12 in Figure 3, the sliding plate 14 on which the seismically isolated object 20 is placed will appear to slide on the upper surface of the fixed rib 12A in the direction opposite to the direction of the seismic motion E due to an inertial force that tries to keep it in its current position (in reality, the lower fixed plate slides more than the upper sliding plate 14).

[0027] In other words, the fixed plate 12 moves in almost exact accordance with the movement of the seismic motion E, but the sliding plate 14 on which the seismically isolated object is placed does not exactly follow the movement of the seismic motion E, and the impact is mitigated as this movement is slowed down. Similarly, even when the seismic motion E is applied to the seismically isolated plate 10 from the left side of the rectangular fixed plate 12 in Figure 3, the sliding plate 14 on which the seismically isolated object 20 is placed slides, due to inertial force, in the opposite direction to the direction of the shaking of the seismic motion E on the upper surface of the fixed rib 12A.

[0028] Furthermore, since seismic motion is a periodic reciprocating motion, the direction of the seismic motion E periodically reverses, and consequently, the direction of sliding of the sliding plate 14 relative to the fixed plate 12 also periodically reverses. In addition, the apparent distance that the sliding plate 14 moves on the fixed plate 12 due to sliding is greater when the magnitude (seismic intensity) of the seismic motion E is large, and also greater when the coefficient of friction between the fixed plate 12 and the sliding plate 14 is small. Moreover, the smaller the coefficient of friction between the fixed plate 12 and the sliding plate 14, the greater the impact applied to the fixed plate 12 by the seismic motion E is mitigated and transmitted to the sliding plate 14.

[0029] In other words, as shown in Figure 3, the lower fixing rib 12A and the upper sliding rib 14A are in contact in an intersecting state, so the upper sliding rib 14A can slide on the lower fixing rib 12A in any direction. Therefore, no matter which direction the seismic motion E is applied to the rectangular fixing plate 12, the sliding plate 14 can slide on the upper surface of the fixing plate 12 in the direction opposite to the direction of the seismic motion E. In this way, the impact applied to the fixing plate 12 by the seismic motion E is mitigated by the buffering effect of the sliding between the fixing plate 12 and the sliding plate 14 and transmitted to the sliding plate 14. As a result, the seismic isolation plate 10 mitigates the impact on the seismically isolated object 20 caused by the seismic motion E, and consequently suppresses the seismically isolated object 20 from tipping over or being damaged.

[0030] In this embodiment, an arrangement in which the fixed rib 12A and the sliding rib 14A are orthogonal in a plan view is illustrated, but the disclosure is not limited thereto, and the fixed rib and the sliding rib may be arranged to intersect at any angle, as long as the ribs do not fit into the gap between the parallel ribs of the other.

[0031] Furthermore, although this embodiment illustrates a case where one seismic isolation plate 10 is placed below the seismically isolated object 20, this disclosure is not limited to this, and it may be placed above another seismically isolated object 20. That is, for example, if the seismically isolated object (first seismically isolated object) has a horizontal upper surface, the first seismic isolation plate may be placed below the seismically isolated object, and the second seismic isolation plate may be placed on the horizontal upper surface of the seismically isolated object. The second seismic isolation plate may then provide seismic isolation for another seismically isolated object (second seismically isolated object) placed on the second seismically isolated plate. Similarly, multiple seismic isolation plates and seismically isolated objects may be arranged in multiple layers, such as a third seismic isolation plate and a third seismically isolated object, a fourth seismic isolation plate and a fourth seismically isolated object, and so on.

[0032] (Effects and Benefits) In the seismic isolation plate 10 according to this embodiment, the lower surface of the fixing plate 12 is installed in contact with the floor surface G, and multiple rows of fixing ribs 12A are formed on the top of the fixing plate 12. "The lower surface of the fixing plate is in contact with the floor surface" includes both the state in which the lower surface of the fixing plate is in direct contact with the floor surface, and the state in which the lower surface of the fixing plate is in contact with the upper surface of another member located on the floor surface side, due to the placement of one or more other members between the fixing plate and the floor.

[0033] Furthermore, the sliding plate 14 is positioned with its lower surface in contact with the upper surface of the fixing rib 12A, and the bottom of the sliding plate 14 has multiple rows of sliding ribs 14A formed in a direction intersecting with the fixing rib 12A, and the seismic isolation object 20 is placed on the upper surface of the sliding plate 14.

[0034] According to this embodiment, a seismic isolation device can be constructed using only two components: a fixed plate 12 having multiple rows of fixed ribs 12A, and a sliding plate 14 having multiple rows of sliding ribs 14A. Therefore, compared to the case where a seismic isolation device is constructed using an upper and lower shoe made by attaching a flat resin sliding material to the surface of a flat metal body, as shown in Patent Document 1, for example, the seismic isolation device can be manufactured more simply. Furthermore, the seismic isolation plate 10 according to this embodiment has a structure that reduces the contact area between the sliding plate 14 and the fixed plate 12 by supporting the sliding ribs 14A on the upper surface of the fixed ribs 12A, thereby reducing the coefficient of friction, making it easy to adjust and improve the seismic isolation performance.

[0035] Furthermore, while a seismic isolation device could be conceivable in which a coating is formed on the upper surface of a metal plate to achieve a predetermined coefficient of friction, this would require coating work in addition to preparing the metal plate, resulting in a more complex manufacturing process and a higher likelihood of quality variations. Also, since the coating is susceptible to wear due to heat, it would be difficult to install in high-temperature locations, or even if installed, maintenance costs would be high. Moreover, if metal materials are used, chemical changes such as corrosion can occur over many years, leading to structural deterioration, changes in the surface coefficient of friction, and a potential deterioration of seismic isolation performance, posing durability issues depending on the usage environment. On the other hand, the seismic isolation plate 10 according to this embodiment does not use metal and does not require a coating, allowing for a simple seismic isolation device structure using resin materials such as POM. Therefore, compared to seismic isolation devices using metal materials and coatings, it can achieve stable quality, reduce manufacturing and maintenance costs, and have a wider range of applicability to installation environments.

[0036] Furthermore, in the seismic isolation plate 10 according to this embodiment, the parts that act as sliding surfaces are multiple ribs arranged in parallel with spaces in between, so the upper surface, which is a virtual plane formed by connecting the vertices of the multiple ribs, acts as a single sliding surface. For this reason, compared to, for example, the case where the sliding surfaces of sliding materials, each a flat plate, are superimposed, the contact area between the sliding surfaces in the seismic isolation plate of this embodiment is small, and therefore the coefficient of friction between the fixed plate 12 and the sliding plate 14 can be made relatively low. Moreover, by appropriately selecting the cross-sectional shape of the fixed rib 12A and the sliding rib 14A according to this embodiment, the coefficient of friction can be adjusted to an appropriate value depending on the application. In addition, because the rib parts have the function of reinforcing materials, the parts other than the ribs can be made thinner or gaps can be provided in the parts other than the ribs. Furthermore, it is possible to make the multiple ribs intersecting each other instead of parallel ribs in one direction, and to make the parts other than the ribs all gaps to form a mesh structure, making it easier to reduce the weight of the seismic isolation device.

[0037] Furthermore, in this embodiment, as shown in Figure 1, the fixed ribs 12A extend in parallel in one direction, and the sliding ribs 14A extend in parallel in one direction intersecting with the fixed ribs 12A. Therefore, the structure of the fixed plate 12 and the sliding plate 14 is simple, which has the advantage of being easy to manufacture.

[0038] Furthermore, in this embodiment, the fixing plate 12 and the sliding plate 14 are made of resin. Therefore, the fixing plate 12 and the sliding plate 14, each having ribs, can be manufactured at low cost and easily, for example, by integral molding of resin. In addition, the external dimensions of the rectangular fixing plate 12 in this embodiment are approximately 800 mm x 1000 mm. In addition, in this embodiment, the height (thickness) from the bottom surface of the fixing plate 12 to the top of the fixing rib 12A is approximately 3.8 mm. In this disclosure, the dimensions of the fixing plate are arbitrary and may be changed as appropriate depending on the application.

[0039] Furthermore, in this embodiment, the thickness (height) of the fixed plate 12 and the sliding plate 14 is made thin to about a few millimeters by resin injection molding, so the position of the sliding plate on which the seismic isolation object 20 is placed is low, and the seismic isolation object 20 can be easily mounted on the seismic isolation plate 10, for example, using a forklift. In addition, the seismic isolation plate 10 according to this embodiment is lightweight and structurally simple, and therefore highly durable. In this disclosure, when the fixed plate and the sliding plate are each made of slider boards as described above, the durability of each can be improved because these are products with a proven track record in terms of strength.

[0040] For example, using a dedicated jig (pressure area: Φ50) on the slider board sample mentioned above, a pressure of 50 t / m² can be applied. 2 Multiple compression friction tests were conducted, applying a vertical load and rubbing the samples 10,000 times. The average thickness of the samples before the test was 3.925 mm, while the average thickness after the test was 3.883 mm. The difference in thickness before and after the test was only 0.042 mm, indicating that the durability of both the fixing plate and the sliding plate can be improved when constructed using the aforementioned slider board. Therefore, it is possible to maintain durability even for heavy seismically isolated objects.

[0041] Furthermore, in this embodiment, the thickness (height) of the fixing plate 12 is made to be only a few millimeters, so even if the sliding plate 14 were to detach from the outer edge of the fixing plate 12 due to an earthquake motion larger than expected, the impact due to the drop would be suppressed, and in this respect as well, it is a relatively safe configuration.

[0042] Furthermore, the seismic isolation plate 10 according to this embodiment only needs to be laid on the existing floor surface G, and no special work or preparation is required on the floor surface for installation. Therefore, the cost of laying the seismic isolation plate 10 is kept relatively low. In addition, by performing preliminary work such as polishing the back surface of the floor surface G and the fixing plate 12 to improve the smoothness, the overall seismic isolation performance can be further improved by improving the static friction coefficient and dynamic friction coefficient between the existing floor surface G and the fixing plate 12. Moreover, in this embodiment, since the seismic isolation plate 10 is made of resin, the manufacturing cost is lower compared to manufacturing a seismic isolation plate from a metal plate such as iron, and it also has high durability as there is no risk of deterioration of the friction coefficient due to corrosion, etc.

[0043] (First variation) Next, a seismic isolation plate 10A according to the first modified example of this embodiment will be described with reference to Figures 4 and 5. As shown in Figure 4, the seismic isolation plate 10A according to the first modified example differs from this embodiment mainly in that an anti-slip portion 16 is provided on the outer circumference of the fixed plate 12 and a side wall 14C is provided around the sliding bottom portion 14B of the sliding plate 14.

[0044] (Anti-slip part) As shown in Figure 5, the anti-slip portion 16 is positioned to surround and contact the peripheral edge of the fixing plate 12, with a gap between the outer edge of the sliding plate 14 placed on the fixing plate 12 and the inner edge of the anti-slip portion 16. In the first modified example, the anti-slip portion 16 is a rubber plate that slopes toward the central part of the fixing plate 12. However, this disclosure is not limited to this, and the anti-slip portion does not necessarily have to be a rubber plate; the material is arbitrary. Furthermore, in this disclosure, it is not necessary for the anti-slip portion to slope toward the central part of the fixing plate; the presence or absence of a slope is optional. For example, a horizontal upper surface flush with the fixing plate 12 may be formed.

[0045] Furthermore, this disclosure is not limited to the above, and the anti-slip portion may be a protruding structure erected on the ends of two or three opposing sides of a rectangular fixing plate, having inner wall surfaces. By arranging a sliding plate (and the seismically isolated object placed thereon) with a shape that contacts all of the inner wall surfaces of the anti-slip portion of the fixing plate on the fixing plate, the sliding plate (and the seismically isolated object) can be attached to (inserted and removed from) the fixing plate from the side where the anti-slip portion of the fixing plate is not erected. In the event of seismic motion, the sliding plate cannot slide in the direction of the anti-slip portion of the fixing plate because it is in contact with the wall surface, so no seismic isolation effect by sliding is obtained. However, the seismically isolated object is reliably supported by the protruding structure of the anti-slip portion of the fixing plate, suppressing overturning and damage. On the other hand, it can slide and move in the direction where the anti-slip portion of the fixing plate is not present, so a seismic isolation effect by sliding is obtained, and overturning and damage are suppressed.

[0046] The outer shape of the fixing plate 12 in the first modified example is larger than that of the sliding plate 14, similar to the embodiment. The sliding plate 14 in the first modified example is configured to maintain a certain degree of sliding ability even when it is not as slippery as it is on the surface of the fixing plate 12, even when it is placed between it and the inclined rubber plate of the anti-slip portion 16. In other words, the sliding plate 14 can slide to some extent on the rubber plate of the anti-slip portion 16 even when the seismic isolation object 20 is placed on its upper surface.

[0047] (Hakama component) The sliding plate 14 having side walls 14C as shown in Figure 5 functions as a skirt member for protecting the seismically isolated object 20. The sliding plate 14 functioning as a skirt member is a tray-shaped receiving member similar in shape to, for example, a sake bottle skirt, having side walls 14C extending upward from the outer edge of the sliding bottom portion 14B, as shown in Figure 5. The side walls 14C are erected on the periphery of the sliding plate 14. The side walls are not essential in this disclosure. The shape of the sliding bottom portion 14B of the sliding plate 14 functioning as a skirt member according to the first modification is disc-shaped, but this disclosure is not limited to this and can be changed as appropriate to a rectangular shape, etc.

[0048] In Figure 5, the inner surface of the side wall in the first modified example is in close contact with the outer surface of the seismic isolation object 20. However, this disclosure is not limited to this, and the entire inner surface of the side wall may or may not be in contact with the outer surface of the seismic isolation object. Furthermore, if there is contact, the entire inner surface of the side wall may be in close contact with the outer surface of the seismic isolation object, or only a part of the inner surface of the side wall of the skirt member may be in close contact. For example, the side wall may be annular in plan view, and the shape of the outer surface of the seismic isolation object may be a polygonal shape in plan view, having vertices inscribed in the circle of the inner surface of the side wall. The other configurations of the seismic isolation plate 10A in the first modified example are the same as those of the seismic isolation plate 10 according to this embodiment, so a redundant explanation is omitted.

[0049] (Effects and Benefits) In the first modified seismic isolation plate 10A, the seismic isolation device can be constructed using only two components: a fixed plate 12 having multiple rows of fixed ribs 12A, and a sliding plate 14 having multiple rows of sliding ribs 14A. Therefore, similar to this embodiment, the seismic isolation device can be easily constructed, and it is also easy to reduce the weight of the seismic isolation device.

[0050] Furthermore, in the first modified example, the outer shape of the fixed plate 12 is larger than that of the sliding plate 14, and the outer circumference of the fixed plate 12 is provided with an anti-slip portion 16 that surrounds and contacts the outer circumference, and has an inner circumference that is outside the outer circumference of the sliding plate 14. As a result, after the sliding plate 14 slides due to vibrations such as seismic motion E input from the outside and reaches the outer circumference of the fixed plate 12, it is suppressed from moving away from the fixed plate 12 and to the outside of the fixed plate 12. In other words, it is possible to suppress the sliding plate 14 from sliding too far beyond the desired range.

[0051] Furthermore, in the first modified example, the anti-slip portion 16 is a rubber plate that slopes toward the central part of the fixed plate 12. Therefore, when the sliding plate 14 reaches the outer circumference of the fixed plate 12 and then climbs the inclined surface of the anti-slip portion 16, the sliding speed of the sliding plate 14 climbing the inclined surface is reduced by the frictional force of the rubber plate, which has a relatively large coefficient of friction, and gravity. Then, the sliding plate 14 that has stopped on the inclined surface descends the inclined surface due to gravity due to its own weight, so the sliding plate 14 slides toward the central part of the fixed plate 12. In other words, the sliding plate 14 can automatically change its position so as to approach the initial position on the fixed plate 12 where it was placed before vibrations such as seismic motion E are applied from the outside. The other effects of the seismic isolation plate 10A in the first modified example are the same as in this embodiment, so a redundant explanation is omitted.

[0052] (Second variation) Next, a seismic isolation plate 10B according to a second modified example of this embodiment will be described with reference to Figures 6 and 7. As shown in Figure 6, the seismic isolation plate 10B according to the second modified example differs from this embodiment mainly in that a projection 15 is provided on the sliding bottom portion 14B of the sliding plate 14, and the tip of the projection 15 is positioned to fit into the gap S between adjacent fixing ribs 12A of the fixing plate 12.

[0053] (protrusion) The seismic isolation plate 10B according to the second modified example has a projection 15 that protrudes below the tip of the sliding rib 14A. As shown in Figure 6, the projection 15 is formed at the lower end of a rod-shaped member or block-shaped member that extends through the sliding bottom portion 14B. The shape of the projection 15 in this embodiment is dome-shaped, but in this disclosure, the shape of the projection is arbitrary as long as the portion that fits into the gap S is spherical, and the curvature of the spherical portion is arbitrary as long as the resistance to the projection fitting into the gap escaping from the gap when a lateral force is applied to the sliding plate and it slides on the fixed plate remains within a predetermined range.

[0054] In Figure 6, the upper end of the rod-shaped or block-shaped member of the projection 15 is flat so as to be flush with the upper surface of the sliding bottom 14B. In this disclosure, it is not essential that the projection be formed at the lower end of the rod-shaped or block-shaped member. Any manufacturing method can be adopted, for example, by integrally forming it with the sliding rib.

[0055] Furthermore, in the second modified example, the projection 15 is provided on the lower side of the sliding plate 14, but the present disclosure is not limited to this, and the projection may be formed on at least one of the upper side of the fixed plate and the lower side of the sliding plate. Also, the projection may be an integral projection formed on the upper side of the fixed plate or the lower side of the sliding plate.

[0056] (Diagonal intersecting ribs) As shown in Figure 7, in the second modified seismic isolation plate 10, the first fixing rib 12A1 and the second fixing rib 12A2, both of which are fixing ribs 12A, intersect diagonally and extend in different directions from each other.

[0057] In Figure 7, the rectangular fixing plate 12 is shown with an example in which cross-shaped resin portions arranged along two diagonals are positioned separately from the first fixing rib 12A1 and the second fixing rib 12A2. These cross-shaped resin portions correspond to areas of recesses pre-positioned in a resin molding die to improve the fluidity of the resin. In this disclosure, the presence or absence of resin portions corresponding to areas that improve the fluidity of the resin is optional.

[0058] Furthermore, similar to the fixed ribs, the sliding rib 14A has a first sliding rib and a second sliding rib that intersect diagonally and extend in different directions from each other. When the fixed plate 12 and the sliding plate 14 slide relative to each other, the fixed rib 12A and the sliding rib 14A always intersect and slide against each other. Note that the fixed plate 12 of the second modified example has a fixed rib 12A where the first sliding rib and the second sliding rib intersect, but does not have a fixed bottom like the fixed bottom 12B of this embodiment. In this way, when multiple fixed ribs intersect and are connected to each other and integrated, the fixed plate can be realized using only the fixed ribs.

[0059] Furthermore, although Figure 7 illustrates a fixed rib 12A with a rectangular cross-sectional shape, the cross-sectional shape of the fixed rib in this disclosure may be, for example, a triangular shape protruding upwards or a rhomboid shape protruding on both sides, as shown by the fixed rib 12A in Figure 2. Even when using fixed ribs that protrude upwards or on both sides, a fixed plate composed solely of fixed ribs without a fixed base can be realized by the intersection of multiple fixed ribs.

[0060] Furthermore, in this disclosure, the intersection angle between the first fixed rib and the second fixed rib, and the intersection angle between the first sliding rib and the second sliding rib, can be arbitrarily set, for example, to greater than 0 degrees and within 90 degrees on the acute side. That is, the intersection pattern in plan view may be orthogonal or diagonal. However, if the width of one rib measured along the parallel direction is the same, the diagonal intersection pattern allows for a larger joint area between the ribs at the intersection compared to the orthogonal intersection pattern, thus making it easier to improve the overall strength. Also, the intersection angle of the fixed plate and the intersection angle of the sliding plate may be the same or different.

[0061] (gap) In the second modified example shown in Figure 7, the fixing plate 12 is illustrated in which a mesh-like gap S (through-hole) is formed between a pair of adjacent and parallel first fixing ribs 12A1 and a pair of adjacent and parallel second fixing ribs 12A2. In this disclosure, the gap is not limited to through-holes, but may also be a recess into which a projection can be fitted, for example, and the number of gaps may be one or more, depending on the number of projections. By changing the number of projections, the effect of suppressing excessive slippage can be adjusted.

[0062] (Fitting of the protrusion and the gap) In the second modified example, the projection 15 fits into the gap S when the fixing plate 12 and the sliding plate 14 are stacked on top of each other. The fitting of the projection 15 into the gap S reduces the seismic isolation performance when seismic motion E is applied, but prevents the sliding plate 14 from sliding too much. In other words, the projection 15 prevents the object to be seismically isolated 20 from sliding too much via the sliding plate 14, which could cause, for example, the base on which the fixing plate 12 is placed to tilt slightly due to seismic motion E, causing the object to slide off the base along with the sliding plate 14, or move to the outside of the fixing plate 12, thereby preventing it from colliding with surrounding equipment or people.

[0063] Specifically, when the sliding plate 14 slides laterally due to seismic motion E, the projection 15 moves laterally and upward from the gap S into which it is fitted, thereby disengaging from the gap S. The projection 15 that has disengaged from the gap S then moves toward the next gap adjacent to the gap S in the lateral direction and engages with this next gap S. In other words, when the sliding plate 14 slides laterally, the sliding plate 14 vibrates along the vertical direction. This repeated engagement of the projection 15 with the gap S in the lateral direction suppresses excessive sliding of the sliding plate 14 compared to a case where the projection 15 and the gap S are not provided.

[0064] Furthermore, the engagement of the projection 15 with the gap S suppresses the movement of the sliding plate 14 relative to the fixed plate 12 when no seismic motion E is applied. For this reason, even if a person lightly touches the seismically isolated object 20, the movement of the sliding plate 14 is suppressed so that it does not slide. In other words, when no seismic motion E is applied to the seismically isolated plate 10, the stability of the arrangement of the seismically isolated object 20 is enhanced.

[0065] The dimensions of the projection 15, the dimensions of the gap S, the static friction coefficient between the fixing rib 12A forming the gap S and the projection 15, and the dynamic friction coefficient between the fixing rib 12A and the projection 15 in the second modified example are set to an extent that excessive sliding is suppressed in both the state in which seismic motion is applied and the state in which seismic motion is not applied.

[0066] (Other examples of fixed plates: inclined surfaces) In the seismic isolation plate 10B illustrated in Figure 8, an inclined surface 12S is formed on the side surface (i.e., the outer edge side surface) of the fixing plate 12, such that the width of the fixing plate 12 (in the case of Figure 8, the width measured along the left-right direction) increases from the top to the bottom. The inclined surface 12S is formed on each of the four sides of the rectangular fixing plate 12. In this disclosure, the inclined surface may be formed on a part of the outer edge of the fixing plate or on the entire outer edge.

[0067] (Inclined surface of anti-slip material) Furthermore, in Figure 8, a non-slip member 19 is placed between the fixing plate 12 and the floor surface G to suppress the sliding of the fixing plate 12. An inclined surface 19S is also formed on the end face of the non-slip member 19, similar to the fixing plate 12. The inclined surface 12S of the fixing plate 12 and the inclined surface 19S of the non-slip member 19 form an integrated inclined surface. The inclined surface 12S of the fixing plate 12 and the inclined surface 19S of the non-slip member 19 are continuous.

[0068] As shown in Figure 8, when seismic motion E is applied to the sliding plates 14 on which the legs 22 of the seismically isolated object 20 are placed, the sliding plates 14 on which the legs 22 of the seismically isolated object 20 are placed may slide laterally and move to the floor surface G outside the seismic isolation plate 10B. However, when the sliding plates 14 on which the legs 22 are placed move from the upper surface of the fixed plate 12 to the floor surface G due to lateral sliding, the sliding plates 14 on which the legs 22 are placed move along the inclined surfaces 12S and 19S. Therefore, compared to, for example, a case where a step rather than an incline is formed between the upper surface of the fixed plate 12 and the floor surface G, the impact applied to the seismically isolated object 20 via the legs 22 can be mitigated.

[0069] Furthermore, if the sliding plate 14 on which the legs 22 of the seismically isolated object 20 rest slides laterally due to the seismic motion E and moves to the floor surface G outside the seismic isolation plate 10B, it is easier to lift the sliding plate 14 on which the moved legs 22 rest onto the fixing plate 12 using the inclined surfaces 19S and 12S. In other words, after the seismic motion E subsides, it is easier to return the position of the sliding plate 14 on which the legs 22 of the seismically isolated object 20 rest to the position it was in before the seismic motion E began.

[0070] Furthermore, as shown in Figure 6, a curved portion 14C1 is formed on the outer edge of the lower end of the sliding plate 14. Therefore, as shown in Figure 8, when the sliding plate 14 with the legs 22 positioned on it moves on the fixed plate 12 or on the inclined surfaces 12S and 19S, even if there are minute protrusions such as debris on the path of movement, the curved portion 14C1 makes it easier for them to overcome them. As a result, for example, the sliding plate 14 moves more smoothly between the fixed plate 12 and the floor surface compared to the case where the outer edge of the lower end of the sliding plate 14 is angular. In this disclosure, the presence or absence of the curved portion, as well as its curvature and shape, are arbitrary, and the case where the outer edge of the lower end of the sliding plate is angular is not excluded.

[0071] (Effects and Benefits) In the second modified seismic isolation plate 10B, the seismic isolation device can be constructed using only two components: a fixed plate 12 having multiple rows of fixed ribs 12A, and a sliding plate 14 having multiple rows of sliding ribs 14A. Therefore, similar to this embodiment, the seismic isolation device can be easily constructed, and it is also easy to reduce the weight of the seismic isolation device.

[0072] Furthermore, in the second modified seismic isolation plate 10B, the first fixed rib 12A1 and the second fixed rib 12A2, both of which are deformations of the fixed rib 12A, intersect each other and extend in different directions. Similarly, the first sliding rib 14A1 and the second sliding rib 14A2, both of which are deformations of the sliding rib 14A, intersect each other and extend in different directions. The fixed ribs 12A1 and 12A2 and the sliding ribs 14A1 and 14A2 intersect each other. Therefore, a relatively unbiased seismic isolation direction can be achieved on the fixed plate 12. The other effects and advantages of the seismic isolation plate 10B in the second modified version are the same as in this embodiment, so a redundant explanation will be omitted.

[0073] <Other Embodiments> Although the present invention has been described by the embodiments disclosed above, the descriptions and drawings that constitute part of this disclosure should not be understood as limiting the invention. It should be understood that various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure. For example, the present invention can be constructed by partially combining the configurations illustrated in the attached drawings. As described above, the present invention includes various embodiments and the like not described above, and the technical scope of the present invention is defined solely by the inventive features of the claims that are reasonable from the above description. [Explanation of Symbols]

[0074] 10, 10A, 10B seismic isolation plates 12 Fixing plate 12A Fixing Rib 12A1 First fixing rib 12A2 Second fixing rib 12B fixed bottom 12S Slope 14 sliding plates 14A Sliding Rib 14B Sliding bottom 14C side wall 14C1 Curved section 15 Protrusion 16 Anti-slip part 19 Anti-slip material 19S Slope 20 Seismic isolation target buildings 22 Legs E. Earthquake motion G Floor surface S Gap

Claims

1. A resin fixing plate having a plurality of fixing ribs integrally molded in parallel on its upper surface and its lower surface fixed to the floor surface, The device comprises a resin sliding plate on which a seismic isolation object is placed, with multiple sliding ribs integrally molded in parallel on the lower surface and overlapping the sliding ribs so as to intersect and contact the fixing ribs, and on the upper surface, The outer diameter of the fixed plate is larger than the outer diameter of the sliding plate, and in the event of an earthquake, the sliding plate on which the object to be seismically isolated is placed slides toward the outer circumference of the fixed plate, thereby preventing the object to be seismically isolated from tipping over.

2. A non-slip portion is provided so as to surround the outer periphery of the aforementioned fixing plate. When no seismic motion is being applied, the sliding plate is located on the central side of the fixed plate. The seismic isolation plate according to claim 1.

3. The anti-slip portion is a rubber plate that slopes toward the center of the fixing plate. The seismic isolation plate according to claim 2.

4. The outer edge side surface of the aforementioned fixing plate has an inclined surface formed such that the width of the fixing plate increases from the top to the bottom. A seismic isolation plate according to any one of claims 1 to 3.

5. Side walls are erected on the peripheral edge of the aforementioned sliding plate. A seismic isolation plate according to any one of claims 1 to 3.

Images