Seismic isolation table unit, and seismic isolation plate

Abstract

To provide a seismic isolation base unit which changes a slide surface absorbing a shock of an earthquake to a resin coating application from a resin sheet pasting, improves workability, and reduces friction coefficient, and a base-isolated plate.SOLUTION: A seismic isolation base unit 1 is composed of: two seismic-isolated members 50, 60 comprising a pair of flat hard support plates 51, 53 (61, 63) which put a cushion seat 52 (62) in between; and an elastic restraint belt 70 binding both seismic-isolated members in the state that they are imposed on each other. On respective surfaces of the support plates 53, 63 facing each other of the seismic-isolated members 50, 60, slide layers 54, 64 made of low friction materials are formed respectively, and one or both of the slide layers 54, 64 are epoxy polyester-based satin coat layers that include a resin coating layer containing polytetrafluoroethylene applied to the support plates 53, 63 and hardened under heat or a bead material applied by powder coating and hardened under heat.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a seismic isolation unit serving as a seismic isolation means for avoiding and reducing the collapse, damage, and falling of articles inside and outside a building, such as furniture, equipment, and goods on shelves, at the time of an earthquake, and a seismic isolation plate.

Background Art

[0002] An earthquake not only causes the collapse and damage of a building itself, but also, even when the building does not collapse, furniture, fixtures, ornaments, etc. inside or around the building, machinery, equipment, spare parts, etc. in an office or factory, and shelves, goods on the shelves, etc. in a store, etc. (in this specification, these are collectively referred to as "furniture, etc.") often collapse or are damaged. Conventional measures for these have mainly been to physically fix the target furniture, etc. Examples include fixing shelves to a wall, installing anti-collapse bars between the ceiling, and fixing equipment to the floor surface. However, since seismic force is composed of a waveform consisting of an undetermined period, acceleration, velocity, and displacement, such anti-overturning measures are not always perfect against such seismic force. Also, even if the merchandise shelves in a store, etc. can be fixed, they do not prevent the goods placed on those shelves from falling.

[0003] To address these problems of the prior art, the applicant of the present application has previously disclosed several seismic isolation countermeasure means. FIG. 3 shows a seismic isolation base 10 disclosed in Patent Document 1, which is one of them, and shows the seismic isolation base 10 in a cross-section perpendicular to the floor surface. In the figure, the seismic isolation base 10 includes a first cushion sheet 11 laid on the floor surface 50, first and second sliding sheets 12 and 13 made of a pair of low-friction materials laid on the first cushion sheet 11, and a second cushion sheet 14 further laid on both sliding sheets 12 and 13. FIG. 3 shows an example applied to a general house, where a carpet 51 is laid on the seismic isolation base 10, and further, as an example, a TV stand 53 with a TV 52 placed thereon is placed. In the drawing, for the sake of convenience, a wide gap is provided between the first and second sliding sheets 12 and 13 constituting the seismic isolation base 10, but this is for easy explanation and understanding, and in reality, they are overlapped so as to be in close contact.

[0004] When laying the first sliding sheet 12 on the first cushion sheet 11, the first sliding sheet 12 may be partially or entirely adhered and welded to the first cushion sheet 11 using an adhesive or an adhesive material. The second sliding sheet 13 located thereon is in a state of being slidable (sliding) between the first sliding sheet 12. Since the earthquake vibration is absorbed between the first and second sliding sheets 12 and 13, it is preferable that the coefficient of static friction between the two sliding sheets 12 and 13 is as low as possible. Here, a fluororesin sheet with a thickness of 0.075 mm is used for both sliding sheets 12 and 13, and the coefficient of static friction between the two can be kept below 0.2. As an alternative material for the sliding sheets 12 and 13, the use of an ultra-high molecular weight polyethylene sheet (preferably with a molecular weight of 1 million or more) has also been proposed, although the coefficient of static friction will be slightly larger.

[0005] Next, a second cushion sheet 14 is laid on the second sliding sheet 13. Both the first and second cushion sheets 11 and 14 are made of rubber sheets. The first cushion sheet 11 absorbs the unevenness of the floor surface, and the second cushion sheet 14 has flexibility to absorb the unevenness of the flat surface of furniture or the like placed thereon. The thickness of both cushion sheets 11 and 14 is, for example, 1.5 mm. When the second cushion sheet 14 is laid on the second sliding sheet 13, they may be partially or entirely closely fixed to each other using an adhesive material or an adhesive. As a result, the first and second sliding sheets 12 and 13 have a sandwich structure sandwiched between the first and second cushion sheets 11 and 14.

[0006] The operation of the seismic isolation base 10 described in Patent Document 1 configured as described above is as follows. When an earthquake occurs, first, the shaking is transmitted to the floor surface 50. This shaking is transmitted to the first cushion sheet 11 and then to the first sliding sheet 12 closely fixed thereto. Since the friction coefficient between the first sliding sheet 12 and the second sliding sheet 13 is low, the latter follows the former up to a certain limit, but when the limit is exceeded, sliding (slipping) occurs between the two sliding sheets 12 and 13. The second sliding sheet 13 is closely fixed to the second cushion sheet 14, and the shaking of the floor surface 50 is not transmitted directly to the TV stand 53 above due to the occurrence of sliding. That is, the seismic isolation effect is achieved by the sliding between them.

[0007] Next, FIG. 4 shows a seismic isolation base unit 1 disclosed in Patent Document 2. First, in FIG. 4(a), the seismic isolation base unit 1 has a first sliding member 50 and a second sliding member 60 overlapped and tied crosswise with a pair of endless belt-like binding bands 70. Here, the first sliding member 50 corresponds to the combination of the first cushion sheet 11 and the first sliding sheet 12 shown in FIG. 3, and similarly, the second sliding member 60 corresponds to the combination of the second cushion sheet 14 and the second sliding sheet 13. Although not shown in the drawing, the first and second sliding members 50 and 60 are in contact with each other with sliding sheets having a low friction coefficient, such as fluororesin sheets, attached to their respective surfaces facing each other.

[0008] Figure 4(b) shows an alternative to Figure 4(a). Here, the difference is that the binding band 70 is not cross-shaped, but instead bundles the two sliding members 50 and 60 by hooking a pair of opposite apex angles facing each other on the main planes of the rectangular sliding members 50 and 60. The other configurations are the same as those in Figure 4(a). To avoid complexity, only one binding band 70 is shown in Figure 4(b) for convenience, but it is possible to add binding bands 70 that similarly hook the remaining two apex angles, thereby enabling the restraint of the non-directional sliding members 50 and 60.

[0009] The binding band 70 may be an endless rubber band that bundles the two sliding members 50 and 60. However, as shown in Figure 4(c), it may also be formed by alternately connecting a pair of telescopic portions 71 and a pair of connecting portions 72 in the longitudinal direction to form an endless belt shape. By doing so, an elastic member with a high expansion ratio, such as ultra-low hardness rubber, can be used for the telescopic portion 71, and a waterproof sheet, rubber sheet, or plastic material with no or low stretchability can be used for the other connecting portion 72. Thus, an appropriate degree of stretch can be selected for the entire binding band 70.

[0010] The operation of the seismic isolation table unit 1 disclosed in Patent Document 2 with the above configuration during an earthquake is basically the same as that of the seismic isolation table 10 shown in Figure 3, but here the seismic isolation table is unitized. It absorbs the shaking caused by the earthquake by moving relatively due to the slippage between the two sliding sheets attached to the two sliding members 50 and 60, thereby achieving a seismic isolation effect. In the seismic isolation table unit 1 shown in Figure 4(a), during an earthquake, the relative movement of the two sliding members 50 and 60 causes elongation in the binding band 70, which is an elastic member connecting the two. As the relative movement amount increases, a stronger reaction force is exerted, fulfilling the vibration damping function of restricting this relative movement amount.

[0011] A further advantage of providing the end band 70 is to impart a restoring force that returns the sliding members 50 and 60 after relative movement to their original origin positions before displacement occurs. In particular, even if the origin return is not instantaneously performed, such as when the weight of furniture or the like is excessively heavy, the restoring force may gradually return to the origin over time due to vibrations or other factors in the surroundings as the restoring force continues to act constantly.

[0012] In the seismic isolation table unit 1 shown in Fig. 4(a), a support plate is further provided outside both sliding members 50 and 60 to further relieve stress concentration due to the load. Note that the reference numerals of each component shown in Figs. 3 and 4 and used in the above description are those used for the corresponding patent documents, and there is no consistency in the reference numerals between the two drawings.

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0014] The seismic isolation base 10 shown in FIG. 3 and the seismic isolation base unit 1 shown in FIG. 4 are each small and easy to handle, and were superior to the seismic isolation base units according to the prior art before them, but there was still room for improvement. For example, since the sliding sheet and the cushion sheet were separate bodies, it was troublesome to use them by overlapping them or to fix them by adhesion, bonding, etc. Also, the cushion sheet was required to have flexibility to absorb the uneven state, and the rubber sheet used also required a certain thickness. For this reason, the seismic isolation base 10 and the seismic isolation base unit 1 as a whole also had thickness, and the height of the equipment to be protected increased. Also, in the seismic isolation base 10, since the cushion sheet received the load, stress concentration occurred locally, and the load distribution to the entire sliding surface was not necessarily sufficient, and local frictional force might occur during sliding.

[0015] Furthermore, the sliding surface is made to slide with fluororesin sheets such as polytetrafluoroethylene sheets facing each other. Although an improvement effect against the prior art was seen, such as being able to keep the static friction coefficient below 0.2, a sliding surface with an even lower friction coefficient is also desired. Since it is effective for vibration absorption that the sliding resistance is small during an earthquake, a further reduction in the friction coefficient is basically desired. However, on the other hand, in some cases, due to an increase in the amplitude of the earthquake, the displacement width of the object to be protected also increases, so there is also a demand to suppress the reduction in the friction coefficient within a certain limit while achieving the seismic isolation effect. Therefore, reducing the friction coefficient leads to an effect of widening the range of selection of the frictional force, and at the same time, enables the setting of a frictional force that is controlled to a certain extent.

[0016] From the above, the present invention aims to provide a seismic isolation base unit and a seismic isolation plate that solve the problems of the previous inventions and improve them.

Means for Solving the Problems

[0017] In the present invention, instead of using a cushion sheet as a material for backing up the sliding sheet, a highly rigid support plate is used. Also, instead of attaching the sliding sheet to the support plate, a sliding layer made of a resin coat or a special coating is directly formed on the support plate by coating or the like, thereby eliminating the labor for attaching the sliding sheet, improving workability, and further reducing the static friction coefficient. By changing the combination of the sliding layers constituting the sliding surface, a seismic isolation base unit is provided that enables expanding the selection range of the friction resistance value, aiming to improve the prior art, and specifically includes the following content.

[0018] That is, one aspect according to the present invention relates to a seismic isolation base unit disposed between furniture or the like arranged inside or around a building and the floor surface of the building to prevent the collapse or damage of the furniture or the like during an earthquake. The seismic isolation base unit is composed of two seismic isolation members each consisting of a pair of flat rigid support plates sandwiching a cushion sheet made of a vibration absorber in a sandwich shape, and an elastic restraint belt that bundles and restrains the two seismic isolation members in a superposed state. On the surfaces of the support plates on the mutually facing sides of the two superposed seismic isolation members, a sliding layer made of a low-friction material that absorbs shaking by sliding with each other during an earthquake is formed. And the sliding layer formed on either one or both of the surfaces of the mutually facing support plates is either a fluororesin coat layer containing polytetrafluoroethylene applied to the surface of the support plate and heat-cured, or an epoxy-polyester-based satin coat layer containing bead material applied by powder coating and heat-cured. The planar shape of the seismic isolation base unit can be any of a polygon, a circle, and an ellipse.

[0019] The sliding layer formed on either of the surfaces of the mutually opposing support plates may be any one of a zinc plating layer of a zinc-plated steel sheet, a polytetrafluoroethylene sheet layer attached to the surface of the support plate, or a ultra-high molecular weight polyethylene sheet layer also attached to the surface of the support plate. Further, the support plate can be any one of a metal plate including an iron plate, a steel plate, a copper plate, and an aluminum plate, a tempered glass plate, and a cured resin plate. From the viewpoint of avoiding sliding noise generated during sliding, either one of the sliding layers is an epoxy-polyester-based satin coat layer containing a bead material applied to the surface of the support plate by powder coating and heat-cured, and the other of the sliding layers is preferably a polytetrafluoroethylene sheet layer of the TF45 series manufactured by Yodogawa Huetec Co., Ltd. attached to the surface of the support plate.

[0020] At least one third sliding member can be further disposed between the pair of sliding members. The third sliding member is composed of a cushion sheet made of a vibration absorbing material and a pair of flat rigid support plates sandwiching the cushion sheet in a sandwich shape. Sliding layers made of a low friction material are respectively formed on the respective surfaces of the pair of support plates on the side opposite to the cushion sheet side. Either one or both of the sliding layers can be either a resin coat layer containing polytetrafluoroethylene applied to the surface of the support plate and heat-cured, or an epoxy-polyester-based satin coat layer containing a bead material applied by powder coating and heat-cured. At this time, the binding band can be composed of a plurality of elastic binding bands that bundle adjacent sliding members among the pair of sliding members and the at least one third sliding member.

[0021] Another aspect of the present invention is composed of a sliding layer with a low coefficient of friction and a support plate made of a flat hard material that forms and backs up the sliding layer on one side. The sliding layer faces the floor surface and is arranged between furniture and the like, and has a seismic isolation effect of absorbing the shaking during an earthquake by sliding between the floor surface and the sliding layer to avoid the collapse and damage of furniture and the like. The sliding layer is either a resin coat layer containing polytetrafluoroethylene applied to the surface of the support plate and heat-cured, or an epoxy-polyester satin coat layer containing bead material applied by powder coating and heat-cured. The present invention relates to a seismic isolation plate characterized by this.

[0022] The seismic isolation plate is provided with a cushion sheet that absorbs the vertical vibration of an earthquake on the surface opposite to the surface on which the sliding layer is formed, and another support plate on top of the cushion sheet. The sliding layer can be arranged between the floor surface and the back surface of furniture and the like with the cushion sheet sandwiched in a sandwich shape by a pair of the support plates as a sliding member.

Effects of the Invention

[0023] By implementing the seismic isolation unit according to the present invention, the manufacturing becomes easier compared to the seismic isolation units according to the prior arts disclosed in Patent Documents 1 and 2, and the effect of providing a seismic isolation unit with lower frictional resistance is achieved. In addition, a seismic isolation plate using the same technology can be used as a simple alternative to a seismic isolation stand.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Best Mode for Carrying Out the Invention

[0025] The seismic isolation base unit according to the first embodiment of the present invention will be described with reference to the drawings. The present invention aims to improve the seismic isolation base unit 1 disclosed in Patent Document 2 shown in FIG. 4. FIG. 1 shows a side cross-sectional view of the seismic isolation base unit 1 according to the present embodiment. Since the overall outline of the seismic isolation base unit 1 is the same as that of the seismic isolation base unit 1 shown in FIG. 4(a), the content will be described with reference to the same figure below. The seismic isolation base unit 1 according to the present embodiment is substantially square in plan view, and mainly includes a first sliding member 50 located on the lower side in FIG. 4(a), a second sliding member 60 in contact therewith above it, and two elastic binding bands 70 connecting the two. However, the substantially square planar shape is an example, and it may be a polygon including a triangle, a quadrilateral, a hexagon, an octagon, a circle, an ellipse (including an oval), or other irregular shapes such as an L shape, a T shape, or a cross shape. By appropriately arranging the binding bands 70 in a shape like a cross shown in FIG. 4(b) according to the shape, the directionality of the restraining force by the binding bands can be removed.

[0026] Returning to FIG. 1, the first sliding member 50 located on the lower side of the drawing of the seismic isolation base unit 1 according to the present embodiment is composed of a pair of support plates 51 and 53 that sandwich a cushion sheet 52 in a sandwich shape from above and below, and a sliding layer 54 formed on the upper surface of the support plate 53. On the other hand, the second sliding member 60 located on the upper side of the drawing is composed of a pair of support plates 61 and 63 that sandwich a cushion sheet 62 in a sandwich shape in a configuration symmetric to the sliding member 50, and a sliding layer 64 formed on the lower surface of the support plate 63. That is, the seismic isolation base unit 1 is combined such that the first and second sliding members 50 and 60 are overlapped with their sliding layers 54 and 64 facing each other and are restrained by the binding bands 70 to be integrated. In FIG. 1, only the four support plates are hatched in cross-section to enhance visibility, and the hatching of other cross-sections is omitted.

[0027] Each of the support plates 51, 53, 61, and 63 uses a rigid flat plate such as a metal plate represented by an iron plate, a steel plate, a copper plate, or an aluminum plate, a plywood, a particle board, a hard plastic, or a tempered glass, etc., so as to evenly disperse the load applied thereto to the cushion sheets 52 and 62. In the present embodiment, each support plate uses a steel plate (SPCC) with a thickness of 1 mm. The cushion sheets 52 and 62 serve to attenuate the vertical impact caused by an earthquake, and a flexible anti-vibration rubber sheet, an asphalt sheet, a rubber mat (ballast mat), a plastic sheet, etc. can be used. In the present embodiment, a flame-retardant rubber sheet with a thickness of 3 mm is used in consideration of indoor use, but this is just an example, and in order to make the entire seismic isolation table unit 1 smaller and lighter, for example, a sheet with a thickness of 1.5 mm can also be used.

[0028] On one surface of each of the cushion sheets 52 and 62, grooves in a cross shape in plan view are carved so that a pair of binding bands 70 can be fitted. Also, for the binding bands 70, a low-hardness styrene-butadiene-based elastomer (TPS), a urethane-based elastomer (TPU), an EPDM-based vulcanized rubber, etc. can be used, and in the present embodiment, an ultra-low hardness silicone rubber with an elongation at break of about 750% is used. What should be noted in the design of the binding bands 70 is to avoid the resonance that may occur with the shaking of an earthquake due to the presence of the binding bands 70, that is, to avoid the coincidence or proximity of the vibration frequency of an earthquake and the natural vibration frequency of furniture or the like pulled by the binding bands 70. By making the binding bands 70 have a configuration in which a plurality of materials are joined together as shown in Fig. 4(c), it is possible to select an appropriate spring constant of the binding bands 70 for avoiding resonance. Also, what is shown by the broken lines at the upper and lower outermost sides in Fig. 1 are optional vibration-absorbing rubbers 91 and 92, which can be additionally used when it is desired to further absorb the vertical vibration.

[0029] The above configuration is basically the same as the seismic isolation unit 1 disclosed in Patent Document 2. However, the characteristic difference in this embodiment lies in the configuration of the sliding layers 54 and 64. In Patent Document 2, a fluororesin sheet with a low coefficient of friction is attached to the sliding surface. In this embodiment, instead of the fluororesin sheet, a resin coat containing a fluororesin such as polytetrafluoroethylene, which serves as the sliding layer, is directly applied to the surfaces of the support plates 53 and 63 of both sliding members 50 and 60. This eliminates the labor required for attaching the fluororesin sheet, simplifies the process, and realizes stronger and lower-friction sliding layers 54 and 64.

[0030] As the resin coat material in this embodiment, a blend material obtained by mixing a polytetrafluoroethylene resin (PTFE) with a low coefficient of friction and a high-hardness binder resin for improving the softness of the resin is used. Although various materials of this type are commercially available, for example, the PTEF resin coat with filler (Tuff Coating) sold by Koyo Co., Ltd. and "Polyflon * PTFE" ( * registered trademark) sold by Daikin Industries, Ltd. correspond to this. These fluororesin coat materials are directly spray-coated on the surfaces of the support plates 53 and 63 and heat-treated to form the desired sliding layers 54 and 64. At this time, in order to enhance the adhesion, it is conceivable to roughen the surfaces of the support plates 53 and 63 in advance by shot blasting or the like. Also, the coating thickness of the sliding layers 54 and 64 is desirably about 20 μm to 100 μm, and the baking conditions are preferably 380 °C × 3 hours as a guideline. However, these are merely examples and are not limited thereto.

[0031] The sliding layers 54 and 64 with low friction coefficients are overlapped with each other, and the effect of vibration absorption can be enhanced by utilizing the slip between the two during an earthquake. The frictional force at this time will be described later. When the specifications of both sliding members 50 and 60 including the sliding layers 54 and 64 are the same, there is no front-back relationship in the seismic isolation table unit 1, and it will have the same configuration no matter which side is placed upward. In the illustrated example, it is assumed that the first sliding member 50 located on the lower side is placed on the floor surface (ground), and furniture or the like is placed on the second sliding member 60 located on the upper side. However, it will be the same even if it is used upside down.

[0032] The surfaces of the support plates 53 and 63 of both sliding members 50 and 60, which are opposite to the surfaces where the sliding layers 54 and 64 are formed, are fixed to the flat surfaces of the cushion sheets 52 and 62 in contact with them by double-sided tapes, adhesives, or the like. Similarly, the support plates 51 and 61 located at the upper and lower outermost sides of the seismic isolation table unit 1 in the figure are fixed to the flat surfaces of the cushion sheets 52 and 62 in contact with them by double-sided tapes, adhesives, or the like. As the adhesive at this time, by using a special double-sided tape that can be attached and detached multiple times, the removal of each support plate 51, 53, 61, and 63 becomes possible, and the maintenance such as the replacement of these support plates and the binding band 70 becomes easy. This type of tape is known as a "peelable double-sided tape" and is available, for example, from Nitoms Co., Ltd.

[0033] The planar size of the seismic isolation table unit 1 is arbitrary, and it can be arbitrarily set from a small size of about 20 cm × about 20 cm to about 1 m × about 1 m or even larger sizes according to the requirements of mechanical devices, furniture, etc. that want to avoid damage. Regarding a small size, it is not realistic to set the size to 20 cm square or less from the stroke of an earthquake. The arrangement of the seismic isolation table unit 1 in the case of implementation is also arbitrary. For small furniture or the like, one of an appropriate size can be arranged, and for large furniture or the like, a plurality of seismic isolation table units 1 can be arranged under one piece of furniture or the like. For those with leg columns such as desks, small ones can be arranged for each leg column. As a special usage method, a plurality of seismic isolation table units 1 can also be stacked and arranged in order to utilize the stroke of the shaking caused by an earthquake.

[0034] The operation of the seismic isolation base unit 1 according to the present embodiment configured as described above is the same as that shown in the seismic isolation base unit 1 of Patent Document 2. That is, when an earthquake occurs, the first sliding member 50 placed on the floor surface vibrates due to the shaking of the earthquake. When the force due to the shaking exceeds a certain limit (for example, when the input acceleration due to the earthquake is about 200 gal) that exceeds the static friction resistance between the sliding layers 54 and 64, sliding occurs between the two sliding layers 54 and 64. Even if the first sliding member 50 vibrates in synchronization with the earthquake, the second sliding member 60 remains within a small vibration range without following it, thereby preventing the furniture or the like placed on the seismic isolation base unit 1 from being affected and preventing its collapse or damage.

[0035] More specifically, when the input acceleration due to the earthquake exceeds about 200 gal, significant sliding occurs between the two sliding members 50 and 60, and even when the input acceleration is 500 gal, the response acceleration of the upper sliding member 60 is suppressed to about 200 gal. This means that even when an earthquake of about seismic intensity 5+ occurs, the seismic intensity transmitted to the furniture or the like placed on the seismic isolation base 1 is reduced to about seismic intensity 5−, thereby preventing the furniture or the like that would have collapsed in the case of an earthquake of seismic intensity 5+ from collapsing and leading to the prevention of damage to the stored supplies and the like.

[0036] The displacement generated between the first sliding member 50 and the second sliding member 60 is absorbed by the elongation of the elastic binding band 70, and it is avoided that the two further displace beyond a predetermined region. Further, after the earthquake subsides, the binding band 70 serves to return to the origin to eliminate the displacement between the two.

[0037] Although there is some overlap, when the seismic isolation base unit 1 according to the present embodiment is compared with the seismic isolation base unit 1 disclosed in Patent Document 2, the following improvement effects can be seen. 1) By opposing fluororesin-coated materials to each other in the sliding part, it is possible to suppress the coefficient of kinetic friction to 0.1 or less, which is lower than that in the case of opposing fluororesin sheets in Patent Document 2, and the vibration absorption ability can be further enhanced. 2) By switching the sliding surface from the attachment of a fluororesin sheet to a sliding layer coated with a fluororesin coating, the workability such as the labor required for sheet attachment can be improved. 3) Similarly, since the fluororesin sheet has been changed to a fluororesin coating, the hardness of the sliding surface has increased, improving the durability as a seismic isolation base unit, and also making it less susceptible to damage such as cutting or peeling of the sliding surface due to foreign matter intrusion. 4) Although slight, the replacement of the resin sheet with a resin coating reduces the thickness. If the specifications of other components are the same, the seismic isolation base unit will also become thinner accordingly, making handling during installation, etc., easier.

[0038] In addition, the following improvement points can be seen in the seismic isolation base unit 1 according to this embodiment with respect to the prior art before Patent Document 2. 1) By forming the sliding layer directly on a highly rigid support plate and backing it up with a cushion sheet, a stable seismic isolation base unit with low frictional resistance, a simple structure, and high rigidity can be obtained. In addition, a seismic isolation effect in the vertical direction can also be obtained. 2) By making the binding band in the form of an endless belt and detachable, it is easy to disassemble and then reassemble each component, and it is extremely easy to install, remove, maintain, and change the combination of each element according to requirements. 3) It can be used for a wide range of objects, from small items such as desks in ordinary households to factory equipment. 4) By utilizing a simple sliding action, there are no mechanical failures, the sliding layer has excellent durability, and stable use over a long period of time is possible. 5) When using rubber, springs, etc., there is a risk that vibrations will be amplified by resonance depending on the frequency of the earthquake, but such a phenomenon is less likely to occur due to the sliding action. In addition, by using ultra-low hardness rubber as the material of the binding band, the durability is superior compared to the case of using general rubber, and the resonance prevention effect can be enhanced.

[0039] Next, the seismic isolation base unit according to the second embodiment of the present invention will be described with reference to the same drawings. The seismic isolation base unit according to the present embodiment has basically the same configuration as the seismic isolation base unit 1 according to the first embodiment shown in FIG. 1, but the materials of the sliding layers 54 and 64 are different. In FIG. 1, the seismic isolation base unit 1 according to the present embodiment replaces the sliding layers 54 and 64, which were fluororesin-coated in the previous embodiment, with satin coat layers. Satin coating means that a bead material composed of fine sand or silicon dioxide particles, also called an aggregate, is mixed into a resin paint such as an epoxy-polyester type, a melamine type, or an acrylic type, and then applied by spraying or powder coating, and then heated and baked. Due to the mixing of the bead material, the painted surface looks like a leather surface with a slightly rough matte texture, which suppresses the gloss of the surface and creates a sense of luxury, so it is often used for coating high-class equipment. In the present embodiment, attention is paid to the fact that the coating film hardness of this satin coat layer is as high as H in terms of the pencil hardness of the JIS standard (by the way, the fluororesin coat layer is H-2H, and the fluororesin sheet is HB level), and it has excellent wear resistance. It was found that this can be utilized as the sliding layer of the seismic isolation base.

[0040] Experimental measurement values regarding the coefficient of friction will be shown in later embodiments. When the sliding layer with a satin coat is rubbed against other sliding layers, it is found that good low friction comparable to or better than that of the fluororesin coat shown in the previous embodiment can be obtained due to the effect of its high coating film hardness. In particular, for the resin surface, it is considered that the effect of the satin coat improves the slipperiness by changing the contact from surface contact to mainly point contact. In the present embodiment, in order to more effectively bring out this feature, a hard sliding layer obtained by baking a powder coating of an epoxy-polyester type resin is realized. The baking condition at this time is about 20 minutes at 180°C, but this is just an example.

[0041] The seismic isolation table unit 1 with a satin coat as the sliding layer is the same as that shown in Fig. 1 except for the difference in the materials of the sliding layers 54 and 64. Also, since its usage method, operation, and improvement effect on the prior art are the same as those shown in the previous embodiments, duplicate explanations here are omitted. Similarly, as an option, vibration-absorbing rubbers 91 and 92 can be arranged to further absorb vertical vibrations.

[0042] Next, the seismic isolation table unit according to the third embodiment of the present invention will be described. In the previous embodiment, it was premised on a combination in which the first sliding member 50 and the second sliding member 60 constituting the seismic isolation table unit 1 had the same configuration. This embodiment presents the applicability when these two are made into a seismic isolation table unit with a combination of specifications of different materials. Even if the components of both sliding members 50 and 60 are basically the same, for example, it is of course possible to make combinations with different specifications such as plate thickness or material. As an example of changing the plate thickness, it is possible to change the thickness of each support plate 51, 53, 61, 63 according to the magnitude of the load they should support and combine them. Also, in order to set the vertical vibration absorption ability to an appropriate value, the thickness of each cushion sheet 52, 62 can be changed. As an example of changing the material, the materials of each support plate 51, 53, 61, 63 can be made into combinations of different materials such as metal plates, plywood, hard plastics, and tempered glass. Similarly, the cushion sheets 52, 62 can also be made into appropriate combinations using rubber sheets, ballast mats, plastic sheets, etc. Thus, the sliding member 50 and the sliding member 60 can be freely combined with different configurations according to the purpose.

[0043] Among these, the following will particularly describe combinations of different configurations of the sliding layers 54 and 64, which are the most important elements for slipperiness. In the previous Embodiments 1 and 2, the sliding layers 54 and 64 were combined as a fluororesin coat containing polytetrafluoroethylene shown in the first embodiment and a satin coat of an epoxy-polyester resin shown in the second embodiment. Although these combinations of sliding layers are preferably in terms of keeping the coefficient of friction low except for some exceptions, when considering the seismic isolation table unit, there may be a case where a seismic isolation table unit with an appropriate coefficient of friction according to the application is desired, not necessarily a low coefficient of friction. As a measure to meet this requirement, the inventors of the present application made one of the two sliding layers 54 and 64 the fluororesin coat or the satin coat, and as a candidate for the other sliding layer, in addition to these two types of materials, the layer of PTFE sheet described in Prior Art Document 1 and a newly galvanized steel sheet were extracted, and the coefficient of friction related to these combinations was verified.

[0044] Regarding the sliding layer with the PTFE sheet attached, it is the same as that shown in Patent Document 1. Regarding the galvanized steel sheet, for example, SGCC obtained by applying hot-dip galvanization with molten zinc or SECC obtained by electro-galvanization on the surface of cold-rolled steel sheet SPCC is known. This galvanized layer is known to function to enhance the corrosion resistance and rust prevention effect of the steel sheet, but it is also expected to act as a lubricant when contacting other elements. In this embodiment, paying attention to this point, assuming that the plating layer of the galvanized steel sheet corresponds to the sliding layer of the present invention and the base steel sheet corresponds to the supporting plate of the present invention, the degree of frictional force when the galvanized steel sheet is used as a sliding element constituting the seismic isolation table 1 is verified.

[0045] Tables 1 and 2 below show the results of experimentally measuring both the static and dynamic friction coefficients for all combinations of the sliding layer, namely, the fluororesin coating shown in the first embodiment, the satin coating shown in the second embodiment, the fluororesin sheet shown in Patent Document 2, and the zinc plating layer described above, which are replaced with the upper layer (upper sliding member 60) and the lower layer (lower sliding member 50). Here, a PTFE resin coating made by Koyo Co., Ltd. is used as the fluororesin coating layer, a satin coating of epoxy-polyester resin powder coating made by Japan Form Service Co., Ltd. is used as the satin coating, a TF45 sheet made by Yodogawa Hutech Co., Ltd. is used as the PTFE sheet, and an SECC material is used as the zinc plating steel sheet. <Static friction coefficient> [Table 1] <Kinematic friction coefficient> [Table 2] <Measurement conditions> - Load capacity: 1.45kg -Pressure area: 100cm 2 (10cm×10cm), surface pressure: 0.0145kg / cm 2 -Tensile jig: Spring-loaded scale 2kg -Tension speed: equivalent to 100mm / min

[0046] From the above test results, generally speaking, as the sliding layer of the seismic isolation unit for obtaining low friction, the combination between the satin coating layer and the fluororesin coating layer seems to be desirable. Conversely, when the PTFE sheet layer and the zinc plating layer are combined without using these coating layers, it can be seen that the friction force is relatively high. Compared with the former friction coefficient (0.02), the latter friction coefficient shows a difference of about 4 to 7 times. However, when the satin coating is arranged on the upper layer, if the lower layer is combined with the same satin coating and the zinc plating, a locking phenomenon will occur and the measurement will be impossible, so these combinations are difficult to recommend. The reasons may include that both the satin coating layer and the plating layer of the zinc-plated steel plate have a rough feeling on the surface, which may inhibit good sliding, or there may be a possibility of generating static electricity. However, since the locking phenomenon can be eliminated by applying a lubricant such as molybdenum disulfide between the two sliding layers facing each other in the seismic isolation unit, or mixing a lubricant into the paint of the satin coating, these specific combinations of sliding layers are not excluded here. From the results in Table 1 and Table 2, it can also be seen that when the satin coating is arranged on the lower layer, no locking phenomenon occurs between the satin coating and the zinc-plated steel plate.

[0047] In addition, depending on the combination of different materials, in addition to locking, noise (sliding noise) may also occur during sliding. From this perspective, although the friction coefficient is slightly inferior, the combination of the satin coating and the PTFE sheet is good, and among the PTFE sheets, the TF45 series sheets manufactured by Yodogawa Huetec Co., Ltd. are particularly good. In the above table test, the TF45-03 sheet with a nominal thickness of 0.13 mm of the sheet is used, but it is not limited to this. It should be noted that, similar to locking, the administration of a lubricant can show an effect of reducing noise.

[0048] Also, although the magnitude of the frictional resistance was described above in a general sense, since there are cases where the order is reversed depending on the combination, the issue of the compatibility between the sliding layers cannot be denied. When selecting the combination of the sliding layers, these elements also need to be considered. Also, as can be seen from the measurement results, the materials of the sliding layers listed in the above table mainly select those with a relatively small coefficient of friction. Although not used in this experiment, since combinations with sliding layers made of other materials are also fully conceivable, by using the materials listed in Embodiments 1 and 2 as a criterion and combining other materials as well, the range of options for the degree of friction can be further expanded. As an example of other materials, the possibility of a sliding layer made of ultra-high molecular weight polyethylene sheet shown in Patent Document 1 can be considered.

[0049] Next, the seismic isolation table unit according to the fourth embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a side cross-sectional view of the seismic isolation table unit 2 according to this embodiment drawn corresponding to FIG. 1. The seismic isolation table unit 2 according to this embodiment is composed of three sliding members 50, 60, and 80 in which a third sliding member 80 is inserted between the first and second sliding members 50 and 60 of the seismic isolation table unit 1 shown in FIG. 1. Among these, the configurations of the first and second sliding members 50 and 60 are the same as those described in the previous embodiments. In contrast, since the third sliding member 80 is capable of sliding between both the first and second sliding members 50 and 60 arranged vertically, sliding layers 81 and 85 are respectively arranged on the upper and lower bearing plates 82 and 84.

[0050] Specifically, in FIG. 2, the third sliding member 80 is composed of a sliding layer 81, a support plate 82, a cushion sheet 83, a support plate 84, and a sliding layer 85 located at the topmost surface from bottom. The individual specifications, materials, and fixing means between these components may basically be the same as those of the components of the first and second sliding members 50 and 60. The sliding layers 81 and 85 of the third sliding member 80 are backed up by rigid support plates 82 and 84 with ensured flatness, respectively, and are configured to obtain smooth sliding with the first and second sliding members 50 and 60. In FIG. 2, for enhancing visibility, cross-sectional hatching is applied only to the support plates, and cross-sectional hatching of other cross-sections is omitted.

[0051] The bundling band 70 that bundles the three-layer sliding members 50, 60, and 80 may bundle the three layers together as in the previous embodiment. However, as shown in FIG. 2, it is preferable to configure it such that the first and third sliding members 50 and 80 are constrained by a pair of bundling bands 70a, and the second and third sliding members 60 and 80 are separately constrained by another pair of bundling bands 70b. By bundling them in pairs with individual bundling bands instead of bundling the three-layer sliding members together, the amount of slippage between the sliding members 50, 60, and 80 during an earthquake can be equalized, and the effect of more smoothly pulling back in the origin position direction after the earthquake can be obtained.

[0052] The operation of the seismic isolation table unit 2 according to the present embodiment configured as described above is basically the same as that of the seismic isolation table unit 1 according to the previous embodiment. However, there are two sliding portions, so a smoother seismic isolation effect can be obtained, and the friction force as a whole is reduced. By dispersing the frictional resistance over the two sliding portions, even if one sliding surface cannot follow the earthquake due to frictional resistance, the other sliding surface can slide effectively and follow, enabling a good seismic isolation effect to be obtained. Also, by using a three-layer seismic isolation table unit 2, it becomes possible to increase the amount of displacement due to sliding, and since the frictional resistance is smaller than that of the seismic isolation table unit 1 shown in FIG. 1, there is an effect of reducing the response acceleration. For example, it is more effective also for applications where the swing amplitude becomes several times the ground movement amplitude due to an earthquake in the upper floors of a high-rise building due to the second and third modes.

[0053] In FIG. 2, the sliding member is three layers, but of course, it is also possible to further add a plurality of third sliding members 80 arranged in the intermediate layer and stack more layers. The sliding layers are arranged so as to face each other even between the plurality of sliding members 80. At that time, it is preferable that the binding bands 70 are arranged to be individually constrained between adjacent sliding members as shown in FIG. 4. Also, the damping rubbers 91 and 92 (see FIG. 2) of the options shown in the previous embodiment can be added in the same way.

[0054] Next, the seismic isolation plate according to the fifth embodiment of the present invention will be described. The "seismic isolation plate" referred to here means a configuration related to the combination of the sliding layer constituting the seismic isolation table unit described in the previous embodiments and the support plate that backs it up. In FIG. 1, the configuration consisting of the support plate 53 and the sliding layer 54, or the configuration consisting of the support plate 63 and the sliding layer 64, respectively corresponds to the seismic isolation plate. Hereinafter, the seismic isolation plate consisting of the support plate 53 and the sliding layer 54 will be described as a representative example.

[0055] The bearing plate 53 used for the seismic isolation plate can be composed of a rigid flat plate-like member such as an iron plate, a steel plate, a copper plate, a metal plate typified by an aluminum plate, a plywood, a particle board, a hard plastic, or a tempered glass, similar to that described in the previous embodiment. Further, the sliding layer 54 is a coating layer formed on one surface of the bearing plate 53, and specifically, it can be composed of either the fluororesin coating shown in the first embodiment or the satin coating shown in the second embodiment.

[0056] As shown in the previous embodiments, the seismic isolation plate can be used as an element for constructing the seismic isolation table unit 1 by overlapping the pair of sliding layers facing each other. Therefore, it goes without saying that the seismic isolation plate alone can be used as a repair item for the seismic isolation table unit 1. In addition, for furniture mainly used indoors such as desks, shelves, wardrobes, storage tables, etc., if the sliding layer 54 of the seismic isolation plate is arranged on the bottom surface of these or the bottom surface of the legs so as to face the floor surface, it can be used as a simple seismic isolation element instead of the seismic isolation table unit 1. However, in this case, it is not suitable for a rough surface such as tatami on the floor surface, and a certain seismic isolation effect can be expected when the floor surface is a relatively hard and smooth surface such as marble, P-tile, or wooden floor.

Explanation of Signs

[0057] 1, 2. Seismic isolation table unit, 50. First sliding member, 51. Bearing plate, 52. Cushion sheet, 53. Bearing plate, 54. Sliding layer, 60. Second sliding member, 61. Bearing plate, 62. Cushion sheet, 63. Bearing plate, 64. Sliding layer, 70, 70a, 70b. Binding band, 71. Stretchable part, 72. Connecting part, 80. Third sliding member, 81. Sliding layer, 82. Bearing plate, 83. Cushion sheet, 84. Bearing plate, 85. Sliding layer, 91, 92. Vibration damping rubber.

Industrial Applicability

[0058] The seismic isolation table unit and the seismic isolation plate according to the present invention can be widely used in the industrial field aiming at the development, manufacture, sale, and use of seismic isolation members.

Claims

1. In a seismic isolation base unit disposed between furniture or the like arranged inside or around a building and the floor surface of the building to prevent the collapse or damage of the furniture or the like during an earthquake, the seismic isolation base unit is composed of two seismic isolation members each consisting of a pair of flat rigid support plates sandwiching a cushion sheet made of a vibration absorber, and an elastic restraint belt that bundles and restrains the two seismic isolation members in a stacked state, sliding layers made of a low-friction material for absorbing sway by mutual sliding during an earthquake are respectively formed on the surfaces of the support plates on the mutually facing sides of the two stacked seismic isolation members, either one of the sliding layers is either a fluororesin coating layer containing polytetrafluoroethylene applied to the surface of the support plate and heat-cured, or an epoxy-polyester satin coating layer containing bead material applied by powder coating and heat-cured, and the other of the sliding layers is either a polytetrafluoroethylene sheet layer pasted on the surface of the support plate or a ultra-high molecular polyethylene sheet layer also pasted on the surface of the support plate. The seismic isolation base unit is characterized by this.

2. The seismic isolation base unit according to Claim 1, wherein the support plate is made of any one of a metal plate including an iron plate, a steel plate, a copper plate, an aluminum plate, a reinforced glass plate, and a cured resin plate.

3. At least one third sliding member is further disposed between the pair of sliding members, the third sliding member is composed of a cushion sheet made of a vibration absorber and a pair of flat rigid support plates sandwiching the cushion sheet in a sandwich-like manner, sliding layers made of a low-friction material are respectively formed on the respective surfaces of the pair of support plates on the side opposite to the cushion sheet side, and the sliding layer formed on either one or both of the surfaces of the pair of support plates is either a resin coating layer containing polytetrafluoroethylene applied to the surface of the support plate and heat-cured, or an epoxy-polyester satin coating layer containing bead material applied by powder coating and heat-cured. The seismic isolation base unit is according to Claim 1.

4. The seismic isolation base unit according to Claim 3, wherein the restraint band is composed of a plurality of elastic restraint bands that bundle adjacent sliding members among the pair of sliding members and the at least one third sliding member. The seismic isolation table unit according to claim 1, wherein the planar shape of the seismic isolation table unit is any one of a polygon, a circle, and an ellipse.

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