Seismic isolation mechanism

Abstract

To provide a base isolation mechanism capable of efficiently transmitting shearing force to whole laminated rubber.SOLUTION: A slider 4 includes a lower sliding part 5, an upper sliding part 6, a laminated rubber part 7, a lower shearing force transmission part 8, and an upper shearing force transmission part 9. The laminated rubber part 7 includes a laminated rubber body 71, a lower joint member 72 joined to the undersurface of the laminated rubber body 71 for transmitting shearing force with the laminated rubber body 71, and an upper joint member 73 joined to the top face of the laminated rubber body 71 for transmitting shearing force with the laminated rubber body 71. The lower shearing force transmission part 8 is disc-shaped whose axis line is a vertical direction, is disposed between the lower sliding part 5 and the lower joint member 72, and transmits shearing force between the lower sliding part 5 and the lower joint member 72 through an outer peripheral surface 81. The upper shearing force transmission part 9 is disc-shaped whose axis line is a vertical direction, is disposed between the upper sliding part 6 and the upper joint member 73, and transmits shearing force between the upper sliding part 6 and the upper joint member 73 through an outer peripheral surface 91.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This invention relates to a seismic isolation mechanism. [Background technology]

[0002] The Great East Japan Earthquake caused extensive damage to logistics facilities such as rack warehouses. It was found that the damage was more due to the collapse and falling of goods stored within the rack structures than to damage to the rack structures themselves. The conditions for the collapse and falling of goods are such that the acceleration of the pallets storing the goods is approximately 500 cm / s². 2 The key is whether the load sliding acceleration (hereinafter referred to as load sliding acceleration) exceeds a certain threshold. In particular, high-rise automated rack warehouses with a height of 15m or more are independent structures with a high aspect ratio (ratio of the length in the height direction to the width direction of the structure), which amplifies acceleration caused by earthquakes. For this reason, the load sliding acceleration near the top of the rack is 500cm / s². 2 This can be significantly exceeded. To prevent cargo collapse and falling, it is crucial to reduce the acceleration near the top of the racks in an automated rack warehouse.

[0003] Patent Document 1 discloses a vibration damping structure in which a TMD (Tuned Mass Damper) is installed on the rack as a structure to reduce acceleration in an automated rack warehouse. Non-Patent Document 1 discloses a vibration damping structure in which a mass damper is installed on the rack. Such vibration damping structures are effective against seismic waves with predominantly long-period components, but in the case of seismic waves with predominantly short-period components such as pulses, tuned TMDs may not be very effective. Also, the load sliding acceleration at the top of the automated rack warehouse is 500 cm / s². 2 The current system is insufficient to control the following, therefore a separate seismic isolation system will be required.

[0004] Patent Document 2 discloses a seismic isolation mechanism that includes rolling bearings, viscous dampers, and horizontal springs between the rack installation section and the warehouse floor. However, because such a seismic isolation mechanism uses rigid horizontal springs in parallel with rolling bearings, it shortens the seismic period, and depending on the characteristics of the seismic waves, it may not be able to efficiently suppress the load sliding acceleration at the top of the automated rack warehouse, potentially resulting in insufficient seismic isolation. Furthermore, the device may be costly.

[0005] Patent Document 3 discloses a vibration isolation and damping system that provides inclined sliding seismic isolation bearings and TMDs on a rack. However, because such a vibration isolation and damping system uses TMDs, it is only effective on racks where the weight and location of the cargo do not fluctuate much (the structural period is almost constant), and the device may occupy the cargo storage space.

[0006] Therefore, the applicant has proposed an inclined elastic sliding bearing that has the advantages of both inclined sliding bearings and laminated rubber as a seismic isolation mechanism to reduce the acceleration of structures (see Patent Document 4). The inclined elastic sliding bearing consists of a lower shoe, an upper shoe, and a slider provided between the lower and upper shoes. The slider consists of laminated rubber positioned in the center in the height direction, a lower sliding part provided below the laminated rubber, and an upper sliding part positioned above the laminated rubber. The outer periphery of the laminated rubber protrudes laterally beyond the sides of the lower and upper sliding parts and is fixed to the lower and upper sliding parts with fasteners. The transmission of shear force between the lower and upper sliding parts and the laminated rubber occurs via the outer periphery of the laminated rubber. Patent Document 4 states that the conditions for adopting an inclined elastic sliding bearing in a low-rise structure are a shear modulus G = 0.34~0.39 N / mm². 2 That is what they say. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2014-141314 [Patent Document 2] Japanese Patent Publication No. 2016-056007 [Patent Document 3] Japanese Patent Publication No. 2018-131317 [Patent Document 4] Japanese Patent Publication No. 2019-138376 [Non-patent literature]

[0008] [Non-Patent Document 1] https: / / www.taisei.co.jp / giken / report / 2013_46 / paper / A046_032.pdf [Overview of the project] [Problems that the invention aims to solve]

[0009] However, in the inclined elastic sliding bearing disclosed in Patent Document 4, since shear force is transmitted from the lower sliding part and the upper sliding part to the outer periphery (protruding part) of the laminated rubber, if the planar shape of the laminated rubber becomes large, there is a risk that the shear force will not be transmitted to the entire laminated rubber.

[0010] Therefore, the present invention aims to provide a seismic isolation mechanism that can efficiently transmit shear force to the entire laminated rubber. [Means for solving the problem]

[0011] To achieve the above objective, the seismic isolation mechanism according to the present invention is provided between a lower structure and an upper structure that are relatively displaceable in the horizontal direction, and is provided on the lower structure, and has a lower sliding surface formed on its upper surface in a V shape that is convex downward along a first horizontal direction; an upper guide part provided below the upper structure, and has an upper sliding surface formed on its lower surface in an inverted V shape that is convex upward along a second horizontal direction perpendicular to the first horizontal direction; and a slider positioned between the lower sliding surface and the upper sliding surface, which is relatively displaceable with respect to the lower guide part in the first horizontal direction along the lower sliding surface, and is also relatively displaceable with respect to the upper guide part in the second horizontal direction along the upper sliding surface, wherein the slider has a lower sliding part provided at the bottom that is slidable on the lower sliding surface, an upper sliding part provided at the top that is slidable on the upper sliding surface, and a front The laminated rubber part supports the lower sliding part and the upper sliding part so that they can move relative to each other in the horizontal direction, a lower shear force transmission part transmits shear force from the lower sliding part to the laminated rubber part, and an upper shear force transmission part transmits shear force from the upper sliding part to the laminated rubber part. The laminated rubber part comprises a laminated rubber body, a lower joining member joined to the lower surface of the laminated rubber body and capable of transmitting shear force to the laminated rubber body, and an upper joining member joined to the upper surface of the laminated rubber body and capable of transmitting shear force to the laminated rubber body. The lower shear force transmission part is disc-shaped with its axis in the vertical direction, is positioned between the lower sliding part and the lower joining member, and transmits shear force between the lower sliding part and the lower joining member via its outer circumferential surface. The upper shear force transmission part is disc-shaped with its axis in the vertical direction, is positioned between the upper sliding part and the upper joining member, and transmits shear force between the upper sliding part and the upper joining member via its outer circumferential surface.

[0012] In the present invention, a shear force is transmitted between the lower sliding portion and the lower joining member through the outer peripheral surface of the disk-shaped lower shear force transmission portion, and a shear force is transmitted between the upper sliding portion and the upper joining member through the outer peripheral surface of the disk-shaped upper shear force transmission portion. As a result, regardless of the sliding direction of the slider, the shear force can be smoothly transmitted without local stress concentration. Further, the influence of rotation and torsion of the laminated rubber on the transmission of the shear force can be suppressed. As a result, in the present invention, the shear force can be efficiently transmitted to the entire laminated rubber.

[0013] Further, in the seismic isolation mechanism according to the present invention, the lower shear force transmission portion may have a lower side inserted into a round hole portion formed in the lower sliding portion and an upper side inserted into a round hole portion formed in the lower joining member, and the upper shear force transmission portion may have an upper side inserted into a round hole portion formed in the upper sliding portion and a lower side inserted into a round hole portion formed in the upper joining member.

[0014] With such a configuration, regardless of the sliding direction of the slider, the shear force can be smoothly transmitted without local stress concentration through the outer peripheral surface of the lower shear force transmission portion, the inner peripheral surface of the round hole portion formed in the lower sliding portion, and the inner peripheral surface of the round hole portion formed in the lower joining member. The shear force can be smoothly transmitted without local stress concentration through the outer peripheral surface of the upper shear force transmission portion, the inner peripheral surface of the round hole portion formed in the upper sliding portion, and the inner peripheral surface of the round hole portion formed in the upper joining member. Further, the influence of rotation and torsion of the laminated rubber on the transmission of the shear force can be suppressed.

[0015] Further, in the seismic isolation mechanism according to the present invention, the maximum deformation amount of the laminated rubber body may be 2.5 times or less the rubber layer thickness of the laminated rubber body.

[0016] With such a configuration, since the maximum deformation amount of the laminated rubber body remains within the elastic range, it is possible to prevent the occurrence of residual displacement.

[0017] Furthermore, in the seismic isolation mechanism according to the present invention, the coefficient of friction between the slider and the lower sliding surface, and the coefficient of friction between the slider and the upper sliding surface are 0.15 or less, and the shear modulus of the laminated rubber body is 0.4 N / mm². 2 More than 0.8N / mm 2 The following is also acceptable.

[0018] By adopting this configuration, the load sliding acceleration at the top of the seismically isolated object is reduced to 500 cm / s². 2 This can be reduced as follows, and seismic displacement can also be suppressed. [Effects of the Invention]

[0019] According to the present invention, the influence of rotation and torsion on the transmission of shear force in laminated rubber can be suppressed. [Brief explanation of the drawing]

[0020] [Figure 1] This figure shows an automated rack warehouse equipped with a seismic isolation mechanism according to an embodiment of the present invention. [Figure 2] This is an overview of seismic isolation mechanisms. [Figure 3] This is a view of the seismic isolation mechanism from above. [Figure 4] This is a cross-sectional view along line AA in Figure 3. [Figure 5] Figure 3 is a cross-sectional view along line BB. [Figure 6] This is an exploded perspective view of the slider. [Figure 7] This is a perspective view of the slider. [Figure 8] This diagram illustrates the restoration characteristics of the seismic isolation mechanism. [Figure 9] This document includes a diagram illustrating the analytical model and a table showing the relationship between the height, mass, and stiffness of the analytical model. [Figure 10] This is a table showing the seismic waves used in the analysis. [Figure 11] This graph shows the relationship between the coefficient of friction at the top of the rack and the maximum response acceleration due to seismic wave 1. [Figure 12]This graph shows the relationship between the coefficient of friction at the top of the rack and the maximum response acceleration due to seismic wave 2. [Figure 13] This graph shows the relationship between the coefficient of friction at the top of the rack and the maximum response acceleration due to seismic wave 3. [Figure 14] This graph shows the relationship between the friction coefficient due to seismic wave 1 and the seismic isolation displacement. [Figure 15] This graph shows the relationship between the friction coefficient due to seismic wave 2 and the seismic isolation displacement. [Figure 16] This graph shows the relationship between the friction coefficient due to seismic wave 3 and the seismic isolation displacement. [Figure 17] This graph shows the relationship between the friction coefficient due to seismic wave 1 and the residual displacement of the bearing. [Figure 18] This graph shows the relationship between the friction coefficient due to seismic wave 2 and the residual displacement of the bearing. [Figure 19] This graph shows the relationship between the friction coefficient due to seismic wave 3 and the residual displacement of the bearing. [Figure 20] This graph shows the relationship between the coefficient of friction caused by seismic wave 1 and the deformation of laminated rubber. [Figure 21] This graph shows the relationship between the coefficient of friction due to seismic wave 2 and the deformation of laminated rubber. [Figure 22] This graph shows the relationship between the coefficient of friction caused by seismic wave 3 and the deformation of laminated rubber. [Modes for carrying out the invention]

[0021] The seismic isolation mechanism according to embodiments of the present invention will be described below with reference to Figures 1-8. As shown in Figure 1, the seismic isolation mechanism 1 according to this embodiment is provided in the seismic isolation layer 13 between the lower structure 11 and the upper structure 12. Multiple seismic isolation mechanisms 1 are provided in the seismic isolation layer 13. Each of the multiple seismic isolation mechanisms 1 provided in the seismic isolation layer 13 has the same configuration. The seismic isolation mechanism of this embodiment employs an inclined elastic sliding bearing. In this embodiment, the lower structure 11 is assumed to be the floor of an automated rack warehouse, and the upper structure 12 is assumed to be a seismic isolation frame 121 provided on the floor via multiple seismic isolation mechanisms 1, and a high-rise rack 122 installed on top of it.

[0022] As shown in Figure 1, the seismic isolation mechanism 1 includes a lower guide section 2 fixed to the upper part of the lower structure 11 (see Figure 1), an upper guide section 3 fixed to the bottom of the upper structure 12 (see Figure 1), and a slider 4 positioned between the lower guide section 2 and the upper guide section 3. In this embodiment, the lower guide section 2 is fixed to the floor surface of the automated rack warehouse of the lower structure 11. The upper guide section 3 is fixed to the lower surface of the seismic isolation frame 121 of the upper structure 12.

[0023] As shown in Figures 2 to 5, the lower guide portion 2 has a main body portion 22 that has a lower sliding surface 21 on which the slider 4 slides, and a fixing portion 23 that is connected to the lower part of the main body portion 22 and fixed to the lower structure 11. The main body portion 22 is formed in the shape of a long, roughly rectangular block and is arranged to extend in one horizontal direction (first horizontal direction). This first horizontal direction is denoted as the X direction, and the other horizontal direction perpendicular to the first horizontal direction (second horizontal direction) is denoted as the Y direction. As shown in Figure 4, the upper surface of the main body portion 22 is a roughly V-shaped inclined surface along the X direction, with the approximate center in the X direction convex downwards. This upper surface of the main body portion 22 is the lower sliding surface 21. The bent portion approximately in the center of the lower sliding surface 21 is denoted as the lower bent portion 211. Furthermore, of the lower sliding surface 21, one side in the X direction from the lower bent portion 211 is denoted as the first lower sliding surface 212, and the other side in the X direction from the lower bent portion 211 is denoted as the second lower sliding surface 213.

[0024] The first lower sliding surface 212 and the second lower sliding surface 213 are inclined surfaces. The inclination angles of the first lower sliding surface 212 and the second lower sliding surface 213 with respect to the horizontal plane are set to the same value (inclination angle θ). In this embodiment, the lower sliding surface 21 is the upper surface of the lower slide plate 24 provided on the upper part of the main body 22. The lower slide plate 24 is made of stainless steel or the like. As shown in Figures 2 and 5, both sides (end faces on both sides in the Y direction) 221, 221 of the main body 22 are substantially vertical surfaces facing the Y direction, and a lower side slide plate 25 is provided on them. The lower side slide plate 25 is made of stainless steel or the like.

[0025] The fixing portion 23 is formed in a plate shape and is joined to the lower surface of the main body portion 22 with the plate surface facing horizontally. In this embodiment, the fixing portion 23 is formed in a substantially rectangular shape with larger dimensions in the X and Y directions than the main body portion 22, and protrudes from the main body portion 22 in the X and Y directions. The fixing portion 23 is fixed to the upper surface of the lower structure 11, that is, to the floor surface of the automated rack warehouse.

[0026] As shown in Figure 4, the upper guide portion 3 has a main body portion 32 that has an upper sliding surface 31 on which the slider 4 slides, and a fixing portion 33 that is connected to the upper part of the main body portion 32 and fixed to the upper structure 12. The main body portion 32 is formed in the shape of a long, roughly rectangular block and is arranged to extend in the Y direction. The lower surface of the main body portion 32 is an inclined surface with a roughly inverted V shape, where the approximate center in the Y direction is convex upwards. This lower surface of the main body portion 32 is the upper sliding surface 31. The bent portion approximately in the center of the upper sliding surface 31 is referred to as the upper bent portion 311. Furthermore, of the upper sliding surface 31, one side in the Y direction from the upper bent portion 311 is referred to as the first upper sliding surface 312, and the other side in the Y direction from the upper bent portion 311 is referred to as the second upper sliding surface 313.

[0027] The first upper sliding surface 312 and the second upper sliding surface 313 are inclined surfaces that are flat. The inclination angles of the first upper sliding surface 312 and the second upper sliding surface 313 with respect to the horizontal plane are set to the same value (inclination angle θ). This inclination angle is the same value as the inclination angle of the first lower sliding surface 212 and the second lower sliding surface 213 with respect to the horizontal plane. In this embodiment, the upper sliding surface 31 is the upper surface of the upper slide plate 34 provided at the lower part of the main body 32. The upper slide plate 34 is made of stainless steel or the like. As shown in Figures 2 and 4, both sides (end faces on both sides in the X direction) 321, 321 of the main body 32 are substantially vertical surfaces facing the X direction, and an upper side slide plate 35 is provided on them. The upper side slide plate 35 is made of stainless steel or the like.

[0028] The fixing portion 33 is formed in a plate shape and is joined to the upper surface of the main body portion 32 with the plate surface facing horizontally. In this embodiment, the fixing portion 33 is formed in a substantially rectangular shape with larger dimensions in the X and Y directions than the main body portion 32, and protrudes from the main body portion 32 in the X and Y directions. The fixing portion 33 is fixed to the lower surface of the superstructure 12, that is, to the lower surface of the seismic isolation frame 121.

[0029] The lower guide section 2 and the upper guide section 3 are substantially the same in form, except for their fixed position and orientation. The lower guide section 2 and the upper guide section 3 are arranged to overlap with a gap between them in the vertical direction, and the slider 4 is positioned at the intersection 41 (see Figure 3) where the lower guide section 2 and the upper guide section 3 overlap in the vertical direction.

[0030] As shown in Figures 6 and 7, the slider 4 includes a lower sliding portion 5, an upper sliding portion 6, a laminated rubber portion 7, a lower shear force transmission portion 8 (see Figure 6), and an upper shear force transmission portion 9 (see Figure 6). The lower sliding portion 5 is provided at the bottom and has a lower contact surface 511 that can slide on the lower sliding surface. The upper sliding portion 6 is provided at the top and has an upper contact surface 611 that can slide on the upper sliding surface. The laminated rubber portion 7 is provided between the lower sliding portion 5 and the upper sliding portion 6 and supports the lower sliding portion 5 and the upper sliding portion 6 so that they can move relative to each other in the horizontal direction. The lower shear force transmission portion 8 transmits shear force from the lower sliding portion 5 to the laminated rubber portion 7. The upper shear force transmission portion 9 transmits shear force from the upper sliding portion 6 to the laminated rubber portion 7.

[0031] The lower sliding portion 5 includes a lower sliding portion body 51 positioned on the lower sliding surface 21, and a pair of lower guide portions 52 that protrude downward from both sides of the lower sliding portion body in the Y direction and are positioned on both sides of the main body portion 22 of the lower guide portion 2 in the Y direction. The lower sliding portion 5 is formed of, for example, steel.

[0032] The lower sliding body 51 is block-shaped with a roughly square shape in plan view when viewed from above. The lower surface of the lower sliding body 51 is the lower contact surface 511. As shown in Figure 4, the lower contact surface 511 is a roughly V-shaped inclined surface along the X direction, with the roughly center in the X direction convex downwards. The bent portion of the lower contact surface 511 in the roughly center in the X direction is referred to as the lower bent portion 512. Of the lower contact surface 511, the side in the X direction from the lower bent portion 512 is referred to as the first lower contact surface 513, and the other side in the X direction from the lower bent portion 512 is referred to as the second lower contact surface 514.

[0033] The first lower contact surface 513 and the second lower contact surface 514 are inclined surfaces that are flat. The inclination angles of the first lower contact surface 513 and the second lower contact surface 514 with respect to the horizontal plane are set to the same value (inclination angle θ). This inclination angle is the same value as the inclination angle of the first lower sliding surface 212 and the second lower sliding surface 213 with respect to the horizontal plane.

[0034] The first lower contact surface 513 and the second lower contact surface 514 are each provided with a lubricant 515 such as Teflon (registered trademark). The lower sliding part body 51 is positioned on the lower sliding surface 21 (lower slide plate 24) of the lower guide part 2 via the lubricant 515. In this embodiment, the coefficient of friction μ between the lower contact surface 511 and the lower sliding surface 21, that is, the coefficient of friction μ between the lower slide plate 24 and the lubricant 515, is 0.15 or more. The upper surface of the lower sliding portion 5 is a horizontal plane. A recess 53 is formed on the upper part of the lower sliding portion 5, opening upward in the center when viewed from above. The shape of the recess 53 when viewed from above is circular.

[0035] The distance between the pair of lower guide sections 52, 52 is slightly greater than the Y-direction dimension of the main body 22 of the lower guide section 2. Bearings 522, 522 are provided on the inner surfaces 521, 521 of the pair of lower guide sections 52, 52 that face each other in the Y-direction. The bearings 522, 522 are in contact with the lower side slide plate 25 on the side surface of the main body 22 of the lower guide section 2.

[0036] The upper sliding portion 6 includes an upper sliding portion body 61 positioned below the upper sliding surface 31, and a pair of upper guide portions 62 that protrude upward from both sides of the upper sliding portion body in the X direction and are positioned on both sides of the main body portion 32 of the upper guide portion 3 in the X direction. The upper sliding portion 6 is formed of, for example, steel.

[0037] The upper sliding body 61 is block-shaped with a roughly square shape in plan view when viewed from above. The upper surface of the upper sliding body 61 is the upper contact surface 611. As shown in Figure 5, the upper contact surface 611 is an inclined surface with a roughly inverted V shape, where the roughly center in the Y direction is convex upwards. The bent portion of the upper contact surface 611 in the roughly center in the Y direction is referred to as the upper bent portion 612. Of the upper contact surface 611, the side in the Y direction from the upper bent portion 612 is referred to as the first upper contact surface 613, and the other side in the Y direction from the upper bent portion 612 is referred to as the second upper contact surface 614.

[0038] The first upper contact surface 613 and the second upper contact surface 614 are inclined surfaces that are flat. The inclination angles of the first upper contact surface 613 and the second upper contact surface 614 with respect to the horizontal plane are set to the same value (inclination angle θ). This inclination angle is the same value as the inclination angle of the first upper sliding surface 312 and the second upper sliding surface 313 with respect to the horizontal plane.

[0039] The first upper contact surface 613 and the second upper contact surface 614 are each provided with a sliding material 615 such as Teflon (registered trademark). The lower sliding part body 51 is positioned below the upper sliding surface 31 (upper slide plate 34) of the upper guide part 3 via the sliding material 615. In this embodiment, the coefficient of friction μ between the upper contact surface 611 and the upper sliding surface 31, that is, the coefficient of friction μ between the upper slide plate 34 and the material 615, is 0.15 or more. The upper surface of the lower sliding portion 5 is a horizontal plane. A recess 63 is formed at the lower part of the upper sliding portion 6, opening downwards in the center when viewed from above. The shape of the recess 63 when viewed from above is circular.

[0040] The distance between the pair of upper guide sections 62, 62 is slightly greater than the X-direction dimension of the main body 32 of the upper guide section 3. Bearings 622, 622 are provided on the inner surfaces 621, 621 of the pair of upper guide sections 62, 62 that face each other in the X-direction. The bearings 622, 622 are in contact with the upper side slide plate 35 on the side surface of the main body 32 of the upper guide section 3. The lower sliding part 5 and the upper sliding part 6 are substantially the same in form except for their position and orientation. The lower sliding part 5 and the upper sliding part 6 are arranged overlapping in the vertical direction via the laminated rubber part 7.

[0041] As shown in Figures 4 to 6, the laminated rubber section 7 comprises a laminated rubber body 71, a lower joining member 72, and an upper joining member 73. The lower joining member 72 is joined below the laminated rubber body 71. The upper joining member 73 is joined above the laminated rubber body 71. The laminated rubber body 71 is a laminated rubber of a known structure in which rubber and thin steel plates are vertically laminated, and is configured to be elastically deformable in the horizontal direction. The laminated rubber body 71 connects the lower joining member 72 and the upper joining member 73 so that they can move relative to each other in the horizontal direction. The shape of the laminated rubber body 71 in plan view is approximately square. The lower joining member 72 and the upper joining member 73 are both flat plates with square surfaces. The lower joining member 72 and the upper joining member 73 are made of, for example, steel or stainless steel. The lower joining member 72 and the upper joining member 73 are positioned so that their surfaces are horizontal. The lower part of the lower joining member 72 has a recess 721 that opens downward in the center when viewed from above. The recess 721 has a circular shape when viewed from above. The upper part of the upper joining member 73 has a recess 731 that opens upward in the center when viewed from above. The recess 731 has a circular shape when viewed from above. The lower joining member 72 and the upper joining member 73 are substantially the same in form except for their position and orientation. The circular recesses in the lower joint member 72 (721), the upper joint member 73 (731), the lower sliding part 5 (53), and the upper sliding part 6 (63) are all approximately the same diameter in plan view.

[0042] The laminated rubber body 71, the lower joining member 72, and the upper joining member 73 have substantially the same shape in plan view, and are arranged in the order of lower joining member 72, laminated rubber body 71, and upper joining member 73 overlapping from bottom to top. The upper surface of the lower joining member 72 is joined to the lower surface of the laminated rubber body 71, and the lower surface of the upper joining member 73 is joined to the upper surface of the laminated rubber body 71. The recess 721 of the lower joining member 72 and the recess 731 of the upper joining member 73 are positioned to overlap in the vertical direction.

[0043] The lower shear force transmission section 8 and the upper shear force transmission section 9 are disc-shaped. The lower shear force transmission section 8 and the upper shear force transmission section 9 are formed from, for example, steel plates. The lower shear force transmission section 8 and the upper shear force transmission section 9 are substantially the same shape and are arranged so that their plate surfaces are horizontal. The outer shapes of the lower shear force transmission section 8 and the upper shear force transmission section 9 are substantially the same as the inner diameters of the recess 721 of the lower joining member 72, the recess 731 of the upper joining member 73, the recess 53 of the lower sliding section 5, and the recess 63 of the upper sliding section 6.

[0044] The lower sliding part 5, the upper sliding part 6, and the laminated rubber part 7 have substantially the same shape in plan view, and are arranged in the order of lower sliding part 5, laminated rubber part 7, and upper sliding part 6, overlapping from bottom to top. A lower shear force transmission unit 8 is positioned between the lower sliding unit 5 and the laminated rubber unit 7. The lower side of the lower shear force transmission unit 8 is inserted into the recess 53 of the lower sliding unit 5, and the upper side is inserted into the recess 721 of the lower joining member 72 of the laminated rubber unit 7. An upper shear force transmission unit 9 is positioned between the upper sliding unit 6 and the laminated rubber unit 7. The upper side of the upper shear force transmission unit 9 is inserted into the recess 63 of the upper sliding unit 6, and the lower side is inserted into the recess 731 of the upper joining member 73 of the laminated rubber unit 7.

[0045] The lower sliding body 51 of the lower sliding part 5 and the lower joining member 72 of the laminated rubber part 7 are joined by bolts at their respective four corners. The upper sliding body 61 of the upper sliding part 6 and the upper joining member 73 of the laminated rubber part 7 are joined by bolts at their respective four corners.

[0046] Such a slider 4 transmits shear force between the lower sliding part and the lower joining member through the outer peripheral surface 81 of the disk-shaped lower shear force transmission part 8, the inner peripheral surface 531 of the concave part 53 of the lower sliding part 5, and the inner peripheral surface 722 of the concave part 721 of the lower joining member 72 of the laminated rubber part 7. Shear force is transmitted between the upper sliding part and the upper joining member through the outer peripheral surface 91 of the disk-shaped upper shear force transmission part 9, the inner peripheral surface 631 of the concave part 63 of the upper sliding part 6, and the inner peripheral surface 732 of the concave part 731 of the upper joining member 73 of the laminated rubber part 7.

[0047] The laminated rubber body 71 of the laminated rubber part 7 is such that when the lower sliding part 5 and the upper sliding part 6 are displaced relative to each other in the horizontal direction, and the relative displacement in the horizontal direction is transmitted through the lower shear force transmission part 8 and the upper shear force transmission part 9, causing the lower joining member 72 and the upper joining member 73 to be displaced relative to each other in the horizontal direction, the rubber part elastically deform follows the relative displacement between the lower joining member 72 and the upper joining member 73. The lower sliding part 5 and the upper sliding part 6 are restored to their original positions by the restoring force (elastic sliding restoring force) of the elastically deformed rubber part.

[0048] In this embodiment, the shear elastic modulus G of the laminated rubber body 71 is set to be 0.4 N / mm 2 or more and 0.8 N / mm 2 or less. The load slip acceleration at the top of the high-rise rack 122 can be made 500 cm / s 2 or less. For the optimal combination to also suppress the seismic isolation displacement to be small, the shear elastic modulus G of the laminated rubber body 71 is 0.4 N / mm 2 (G6), and the friction coefficient μ is 0.1. The primary shape coefficient S1 of the laminated rubber body 71 is set to S1 > 20, the secondary shape coefficient S2 of the laminated rubber body 71 is set to S2 ≧ 5, and the maximum deformation of the laminated rubber body 71 is set to be 2.5 times or less of the total rubber thickness (n × tr) of the laminated rubber body 71. The primary shape factor S1 of the laminated rubber body 71 is an index representing the vertical stiffness of the laminated rubber, and is given by S1 = a × b / (2 × (a + b) × tr). The secondary shape factor S2 of the laminated rubber body 71 is an index representing the horizontal stability of the laminated rubber, and is given by S2 = min(a or b) / (n × tr). In the above formulas, a and b are the respective side lengths of the rubber in the laminated rubber body 71, n is the number of rubber layers in the laminated rubber body 71, and tr is the thickness of one rubber layer in the laminated rubber body 71.

[0049] In this type of seismic isolation mechanism 1, when an earthquake occurs and the lower structure 11 and the upper structure 12 are displaced relative to each other in the horizontal direction, the laminated rubber part 7 deforms in accordance with the relative displacement between the lower guide part 2 fixed to the lower structure 11 and the upper guide part 3 fixed to the upper structure 12, and the slider 4 slides on the lower sliding surface 21 and the upper sliding surface 31.

[0050] In the initial state (normal operation) of the seismic isolation mechanism 1, as shown in Figures 2 to 5, the laminated rubber portion 7 is not deformed, and the slider 4 is positioned in its original location relative to the lower guide portion 2 and the upper guide portion 3. When the slider 4 is positioned in its original location, the first lower contact surface 513 contacts the first lower sliding surface 212 of the lower guide portion 2, the second lower contact surface 514 contacts the second lower sliding surface 213 of the lower guide portion 2, the first upper contact surface 613 contacts the first upper sliding surface 312 of the upper guide portion 3, and the second upper contact surface 614 contacts the second upper sliding surface 313 of the upper guide portion 3.

[0051] When the slider 4 moves from its original position to one side in the X direction (left side in Figure 4) relative to the lower guide 2, the first lower contact surface 513 is in contact with the first lower sliding surface 212, but the second lower contact surface 514 is separated from the second lower sliding surface 213, and the slider 4 slides along the lower sliding surface 21 so as to move upwards over the first lower sliding surface 212. When the slider 4 moves from its original position to the other side in the X direction (right side in Figure 4) relative to the lower guide 2, the second lower contact surface 514 is in contact with the second lower sliding surface 213, but the first lower contact surface 513 is separated from the first lower sliding surface 212, and the slider 4 slides along the lower sliding surface 21 so as to move upwards over the second lower sliding surface 213.

[0052] Furthermore, when the slider 4 moves from its original position to one side in the Y direction (left side in Figure 5) relative to the upper guide 3, the first upper contact surface 613 is in contact with the first upper sliding surface 312, but the second upper contact surface 614 is separated from the second upper sliding surface 313 as the slider 4 slides down the first upper sliding surface 312. When the slider 4 moves from its original position to the other side in the Y direction (right side in Figure 5) relative to the upper guide 3, the second upper contact surface 614 is in contact with the second upper sliding surface 313, but the first upper contact surface 613 is separated from the first upper sliding surface 312 as the slider 4 slides down the second upper sliding surface 313 as the slider 4 slides down the second upper sliding surface 313.

[0053] In this way, the slider 4 changes its height dimension by moving up and down relative to the lower guide section 2 and the upper guide section 3. However, in this embodiment, since the multiple seismic isolation mechanisms 1 provided in the seismic isolation layer 13 have the same inclination angle θ, even if an earthquake occurs and the lower guide section 2 and the upper guide section 3 are displaced relative to each other in the horizontal direction, the upper end of each seismic isolation mechanism 1 will be at the same height, and the lower end of each seismic isolation mechanism 1 will be positioned at the same height. As a result, even if the lower structure 11 and the upper structure 12 are displaced relative to each other in the horizontal direction, the upper structure 12 remains horizontal.

[0054] In the seismic isolation mechanism 1, when the slider 4 and the lower guide 2 are displaced relative to each other in the X direction, the slider 4 is displaced relative to the lower guide 2 so as to move upward along the lower sliding surface 21 of the lower guide 2. As a result, the relative displacement between the slider 4 and the lower guide 2 is stored as potential energy, which becomes a restoring force (tilt restoring force) that allows the slider 4 to return to its original position. When the slider 4 and the upper guide 3 are displaced relative to each other in the Y direction, the upper guide 3 is displaced relative to the slider 4 so as to move upward along the inclined surface 611 of the upper contact surface of the slider 4. As a result, the relative displacement between the slider 4 and the upper guide 3 is stored as potential energy, which becomes a restoring force (tilt restoring force) that allows the slider 4 to return to its original position. If W is the vertical load acting on the upper guide section 3, the tilt restoring force (horizontal force) F can be expressed as F = Wtanθ, where θ is the angle of inclination with respect to the horizontal plane.

[0055] In this embodiment, when the relative displacement between the lower structure 11 and the upper structure 12 is small, only the laminated rubber body 71 deforms, and the slider 4 does not slide on the lower sliding surface 21 and the upper sliding surface 31. When the relative displacement between the upper structure 12 and the lower structure 11 becomes large, and the horizontal displacement of the laminated rubber body 71 relative to its original position exceeds a predetermined horizontal displacement setting value, the slider 4 is configured to slide on the lower sliding surface 21 and the upper sliding surface 31.

[0056] Figure 8 shows the restoring force characteristics (load-deformation relationship) of the seismic isolation mechanism 1 according to this embodiment. The frictional resistance force μW after slip occurs is generally greater than the tilt restoring force Wtanθ, and the combination of the two is the restoring force characteristic of the seismic isolation mechanism 1.

[0057] We conducted a verification of the seismic isolation effect of an automated rack warehouse equipped with the seismic isolation mechanism 1 according to this embodiment. The object of analysis is an automated rack warehouse with a height of 28m. Figure 9 shows the analysis model, its height, mass, and stiffness model. The mass W of the superstructure is 1,438,683 kg. Hereafter, the seismic isolation mechanism 1 according to this embodiment may be referred to as "inclined elastic sliding bearing". The specifications for seismic isolation mechanism 1 (inclined elastic sliding bearing) are as follows: The coefficient of friction is μ (10 types), and the inclination angle is 1.5°. The shear stiffness of laminated rubber is given by the following formula. krb = W × 9.8 × G / (σ × trb) Here, G: Shear stiffness of rubber σ: Surface pressure of laminated rubber (= 5.86 N / mm²) 2 ) trb: Natural rubber layer thickness (=40mm) 9.8: Gravitational acceleration (m / s 2 ) Primary shape factor S1 = 20 Secondary shape factor S² = 8 Let's assume that.

[0058] The parameters are (1) to (3) below. (1) Seismic waves: Three types of Level 2 earthquakes as shown in Figure 10 (2) Shear modulus G of the laminated rubber body (the following 5 types): G3 (0.3 N / mm) 2 ), G4 (0.4 N / mm 2 ), G6 (0.6N / mm 2 ), G8 (0.8N / mm 2 ), G10 (1.0 N / mm 2 ) (3) Coefficient of friction μ (the following 10 types): 0.01, 0.03, 0.05, 0.07, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3 For comparison, we also present the results of the acceleration analysis at the top of a non-seismic isolation structure and a seismic isolation / damping system with inclined sliding bearings + TMD (3% of the effective mass). Below, the non-seismic isolation structure will be referred to as "non-seismic isolation," and the seismic isolation / damping system with inclined sliding bearings + TMD (3% of the effective mass) will be referred to as "inclined sliding bearings + TMD."

[0059] Figures 11 to 13 show the maximum response acceleration at the top of the rack for each seismic wave. It can be confirmed that seismic isolation mechanism 1 (inclined elastic sliding bearing) can significantly reduce the maximum response acceleration at the top of the rack compared to non-seismic isolation. Furthermore, it can be confirmed that seismic isolation mechanism 1 (inclined elastic sliding bearing) can reduce the maximum response acceleration at the top of the rack compared to inclined sliding bearing + TMD. The following can be seen when comparing the acceleration reduction effects. Shear modulus of laminated rubber body G: G3 > G4 > G6 > G8 > G10 Coefficient of friction μ: 0.01 > 0.03 > 0.05 > 0.07 > 0.09 > 0.1 > 0.15 > 0.2 > 0.25 > 0.3 In seismic isolation mechanism 1 (inclined elastic sliding bearing), the load sliding acceleration is 500 cm / s². 2 To achieve the following, if the coefficient of friction μ is set to approximately 0.15 or less, the shear modulus G of the laminated rubber body can be set to G3, G4, or G6. If the coefficient of friction μ is set to approximately 0.1 or less, the shear modulus G of the laminated rubber body can be set to G3, G4, G6, or G8.

[0060] Figures 14 to 16 show the seismic isolation displacement for each seismic wave. Comparing the magnitude of the seismic isolation displacement reveals the following: Shear modulus of laminated rubber body G: G3 > G4 > G6 > G8 > G10 For friction coefficients μ: μ > 0.1 to 0.15 and above, it can be confirmed that the increase in seismic isolation displacement for G6, G8, and G10 is smaller compared to G3 and G4.

[0061] Figures 17 to 19 show the residual displacement of the tilt elastic sliding bearing for each seismic wave. It can be confirmed that the residual displacement of the tilt elastic sliding bearing is approximately 10 mm or less, regardless of the shear modulus G and the friction coefficient μ.

[0062] Figures 20 to 22 show the deformation of the rubber for each seismic wave. In Figures 20 to 22, the deformation of the rubber is expressed as a ratio to the rubber thickness of 40 mm. It can be seen that the ratio of rubber deformation to rubber thickness increases as the coefficient of friction μ increases. It can be seen that the deformation of the rubber decreases as the shear modulus G increases. In order to suppress the deformation to elastic displacement, the ratio of rubber deformation to rubber thickness needs to be about 2.5 times or less, so it can be seen that the coefficient of friction μ needs to be 0.15 or less.

[0063] Based on the above analysis, the maximum response acceleration (load sliding acceleration) at the top of the rack is 500 cm / s². 2 To keep the following conditions in mind, it is preferable to set the conditions of seismic isolation mechanism 1 (inclined elastic sliding bearing) as follows. The shear modulus G of the laminated rubber body is set to G4, G6, or G8, and the coefficient of friction μ is set to 0.15 or less. By doing so, residual displacement can be suppressed, and the maximum deformation of the rubber is limited to about 2.5 times the rubber thickness. The maximum response acceleration (load sliding acceleration) at the top of the rack is 500 cm / s². 2 The optimal combination for keeping the following conditions down while also minimizing seismic displacement is to set the shear modulus G of the laminated rubber body to G6 and the friction coefficient μ to 0.1.

[0064] Next, the operation and effects of the seismic isolation mechanism according to this embodiment will be described. In the seismic isolation mechanism 1 according to this embodiment, shear force is transmitted between the lower sliding part and the lower joining member via the outer circumferential surface 81 of the disc-shaped lower shear force transmission part 8, the inner circumferential surface 531 of the recess 53 of the lower sliding part 5, and the inner circumferential surface 722 of the recess 721 of the lower joining member 72 of the laminated rubber part 7. Shear force is transmitted between the upper sliding part 6 and the upper joining member 73 via the outer circumferential surface 91 of the disc-shaped upper shear force transmission part 9, the inner circumferential surface 631 of the recess 63 of the upper sliding part 6, and the inner circumferential surface 732 of the recess 731 of the upper joining member 73 of the laminated rubber part 7. Therefore, regardless of the sliding direction of the slider 4, shear force can be transmitted smoothly without local stress concentration. This makes it possible to suppress the influence of rotation and torsion of the laminated rubber body 71 on shear force transmission. The seismic isolation mechanism 1 of this embodiment employs an inclined elastic sliding bearing, which makes it less prone to twisting even with the uneven load and load fluctuations characteristic of rack warehouses, and thus provides a stable response reduction effect.

[0065] In the seismic isolation mechanism 1 according to this embodiment, the maximum deformation of the laminated rubber body 71 is 2.5 times or less the thickness of the rubber layer of the laminated rubber body 71. By adopting this configuration, the maximum deformation of the laminated rubber body 71 remains within the elastic range, thus preventing residual displacement from occurring.

[0066] In the seismic isolation mechanism 1 according to this embodiment, the coefficient of friction μ between the slider 4 and the lower sliding surface 21, and the coefficient of friction μ between the slider 4 and the upper sliding surface 31 are both 0.15 or less, and the shear modulus G of the laminated rubber body is 0.4 N / mm². 2 More than 0.8N / mm 2 The following applies. By adopting this configuration, the load sliding acceleration at the top of the seismically isolated object is reduced to 500 cm / s². 2 The following can be achieved, and seismic displacement can be suppressed. Therefore, by adopting the seismic isolation mechanism 1 of this embodiment, it becomes possible to install a high-rise automated rack warehouse even in a narrow factory room.

[0067] Because tilted elastic sliding bearings have no natural period, they are not affected by the rigidity of the bearing and can handle seismic waves with predominantly long-period components as well as seismic waves with predominantly short-period components such as pulses.

[0068] Although embodiments of the seismic isolation mechanism according to the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, although the above embodiment is proposed for high-rise automated rack warehouses, it can also be applied to low-rise automated rack warehouses and buildings.

[0069] In the above embodiment, the disc-shaped lower shear force transmission part 8 is inserted into the recess 53 of the lower sliding part 5 and the recess 721 of the lower joining member 72 of the laminated rubber part 7, and the disc-shaped upper shear force transmission part 9 is inserted into the recess 63 of the upper sliding part 6 and the recess 731 of the upper joining member 73 of the laminated rubber part 7. Alternatively, the disc-shaped lower shear force transmission part 8 may be joined to either the lower sliding part 5 or the lower joining member 72 of the laminated rubber part 7 and inserted into the recess formed on the other, and the disc-shaped upper shear force transmission part 9 may be joined to either the upper sliding part 6 or the upper joining member 73 of the laminated rubber part 7 and inserted into the recess formed on the other.

[0070] The coefficient of friction μ between the slider 4 and the lower sliding surface 21, the coefficient of friction μ between the slider 4 and the upper sliding surface 31, and the shear modulus G of the laminated rubber body may be set as appropriate.

[0071] The primary shape coefficient S1, secondary shape coefficient S2, and maximum deformation amount of the laminated rubber body 71 may be set as appropriate.

[0072] Among the 17 international goals adopted at the UN Summit in September 2015 are the "Sustainable Development Goals (SDGs)." The seismic isolation mechanism according to this embodiment can contribute to achieving some of the 17 Sustainable Development Goals (SDGs), such as Goal 11, "Make cities and human settlements inclusive, safe, resilient and sustainable." [Explanation of Symbols]

[0073] 1. Seismic isolation mechanism 2 Lower guide section 3 Upper guide section 4 Slider 5 Lower sliding part 6 Upper sliding part 8. Lower shear force transmission section 9 Upper shear force transmission section 7 Laminated rubber section 11 Substructure 12 Superstructure 13 Seismic isolation layer 21 Lower sliding surface 31 Upper sliding surface 53 Recess 63 recess 71 Laminated rubber body 72 Lower connecting member 73 Upper joint member 81 Outer surface 91 Outer surface 511 Lower contact surface 611 Upper contact surface 721 recess 731 recess

Claims

1. It is provided between a lower structure and an upper structure that are capable of relative displacement in the horizontal direction, A lower guide portion is provided on the lower structure and has a lower sliding surface formed on its upper surface in a V-shape that protrudes downward along the first horizontal direction, An upper guide portion provided below the superstructure, having an upper sliding surface formed on its lower surface in an inverted V shape that is convex upward along a second horizontal direction perpendicular to the first horizontal direction, The device comprises a slider positioned between the lower sliding surface and the upper sliding surface, which is displaceable relative to the lower guide portion in the first horizontal direction along the lower sliding surface, and displaceable relative to the upper guide portion in the second horizontal direction along the upper sliding surface, The aforementioned slider is A lower sliding part provided at the bottom and capable of sliding on the lower sliding surface, An upper sliding part provided at the top and capable of sliding on the upper sliding surface, A laminated rubber portion is provided between the lower sliding portion and the upper sliding portion and supports the lower sliding portion and the upper sliding portion so that they can move relative to each other in the horizontal direction. A lower shear force transmission section that transmits shear force from the lower sliding section to the laminated rubber section, It has an upper shear force transmission section that transmits shear force from the upper sliding section to the laminated rubber section, The laminated rubber portion is Laminated rubber body, A lower joining member is joined to the lower surface of the laminated rubber body and is capable of transmitting shear force to the laminated rubber body, The laminated rubber body has an upper joining member that is joined to the upper surface of the laminated rubber body and is capable of transmitting shear force to the laminated rubber body, The lower shear force transmission section is disc-shaped with its axis in the vertical direction, and is positioned between the lower sliding section and the lower joining member, transmitting shear force between the lower sliding section and the lower joining member via its outer circumferential surface. The upper shear force transmission section is disc-shaped with its axis in the vertical direction, and is positioned between the upper sliding section and the upper joining member. This seismic isolation mechanism transmits shear force between the upper sliding section and the upper joining member via its outer circumferential surface.

2. The lower shear force transmission section is inserted into a circular hole formed in the lower sliding section at its lower end, and into a circular hole formed in the lower joining member at its upper end. The seismic isolation mechanism according to claim 1, wherein the upper shear force transmission portion is inserted into a circular hole formed in the upper sliding portion at its upper end and into a circular hole formed in the upper joining member at its lower end.

3. The seismic isolation mechanism according to claim 1 or 2, wherein the maximum deformation of the laminated rubber body is 2.5 times or less the thickness of the rubber layer of the laminated rubber body.

4. The coefficient of friction between the slider and the lower sliding surface, and the coefficient of friction between the slider and the upper sliding surface, are 0.15 or less. The shear modulus of the laminated rubber body is 0.4 N / mm². ２ 0.8N / mm or more ２ The seismic isolation mechanism according to claim 1 or 2, which is as follows:

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