JP2024024357A - Seismic isolation mechanism - Google Patents

Abstract

An object of the present invention is to provide a seismic isolation mechanism that can efficiently transmit shear force to the entire laminated rubber. A slider 4 includes a lower sliding part 5, an upper sliding part 6, a laminated rubber part 7, a lower shear force transmitting part 8, and an upper shear force transmitting part 9, The laminated rubber part 7 includes a laminated rubber body 71, a lower joining member 72 that is joined to the lower surface of the laminated rubber body 71 and is capable of transmitting shear force to the laminated rubber body 71, and a laminated rubber body 72 that is joined to the upper surface of the laminated rubber body 71. 71 and an upper joint member 73 capable of transmitting shear force. The upper shear force transmitting part 9 has a disc shape with an axis in the vertical direction, and transmits shear force between the lower sliding part 5 and the lower joining member 72 via the outer peripheral surface 81. It is arranged between the sliding part 6 and the upper joining member 73, and transmits shear force between the upper sliding part 6 and the upper joining member 73 via the outer peripheral surface 91. [Selection diagram] Figure 6

Description

The present invention relates to a seismic isolation mechanism.

During the Great East Japan Earthquake, a lot of damage was seen in logistics facilities such as rack warehouses. It has been found that more damage is caused by the contents stored in the rack structure collapsing or falling than by damage to the rack structure itself, which is a structure in which racks are arranged in multiple stages. The condition for the stored items to collapse or fall is whether the acceleration of the pallet housing the stored items exceeds approximately 500 cm/s ² (hereinafter referred to as load sliding acceleration). In particular, high-rise automated rack warehouses with a height of 15 m or more are likely to amplify acceleration due to earthquakes because they are independent structures with a high tower ratio (the ratio of the length of the structure in the height direction to the width direction). Therefore, the load sliding acceleration near the top of the rack may significantly exceed 500 cm/ ^s2 . In order to prevent stored items from collapsing or falling, it is important to reduce the acceleration near the tops of racks in automated rack warehouses.

As a structure for reducing acceleration in an automated rack warehouse, Patent Document 1 discloses a TMD (tuned mass damper) or a vibration damping structure provided in the rack. Non-Patent Document 1 discloses a vibration damping structure in which a mass damper is provided in a rack. Such a damping structure has a damping effect on seismic waves with predominant long-period components, but in the case of seismic waves with predominant short-period components such as pulses, a tuned TMD has little damping effect. There are cases. Furthermore, since it is insufficient to suppress load sliding acceleration at the top of an automated rack warehouse to 500 cm/s ² or less, a separate seismic isolation system is required.

Patent Document 2 discloses a seismic isolation mechanism that includes a rolling support, a viscous damper, and a horizontal spring between a rack installation part and a warehouse floor. This type of seismic isolation mechanism uses rigid horizontal springs in parallel with rolling bearings, so the period is short, and depending on the characteristics of seismic waves, it may not be possible to efficiently suppress load sliding acceleration at the top of an automated rack warehouse. There is a possibility that a proper seismic isolation effect cannot be obtained. Additionally, the equipment may be costly.

Patent Document 3 discloses a vibration isolation system in which a rack is provided with an inclined sliding seismic isolation support and a TMD. Since such a vibration damping system uses TMD, it is only effective for racks where the weight of the cargo and the location where it is placed do not change much (the structural period is almost constant), and the device occupies the storage space for the cargo. Sometimes.

Therefore, the applicant has proposed an inclined elastic sliding bearing that has the advantages of both an inclined sliding bearing and a laminated rubber as a seismic isolation mechanism for reducing the acceleration of a structure (see Patent Document 4). The inclined elastic sliding bearing is composed of a lower shoe, an upper shoe, and a slider provided between the lower shoe and the upper shoe. The slider is constituted by a laminated rubber disposed at the center in the height direction, a lower sliding part provided below the laminated rubber, and an upper sliding part disposed above the laminated rubber. The outer periphery of the laminated rubber protrudes laterally beyond the side surfaces of the lower sliding part and the upper sliding part, and is fixed to the lower sliding part and the upper sliding part with fixtures. Transmission of shear force between the lower sliding part and the upper sliding part and the laminated rubber is performed via the outer periphery of the laminated rubber. In Patent Document 4, the shear elastic modulus G=0.34 to 0.39 N/mm ² is set as a condition for adopting a tilted elastic sliding bearing in a low-rise structure.

Japanese Patent Application Publication No. 2014-141314 Japanese Patent Application Publication No. 2016-056007 Japanese Patent Application Publication No. 2018-131317 Japanese Patent Application Publication No. 2019-138376

https://www.taisei.co.jp/giken/report/2013_46/paper/A046_032.pdf

However, in the inclined elastic sliding bearing disclosed in Patent Document 4, since the shear force is transmitted from the lower sliding part and the upper sliding part to the outer peripheral part (projection part) of the laminated rubber, the flat surface of the laminated rubber If the visual shape becomes large, there is a possibility that the shear force will not be transmitted to the entire laminated rubber.

Accordingly, an object of the present invention is to provide a seismic isolation mechanism that can efficiently transmit shear force to the entire laminated rubber.

In order to achieve the above object, a 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, is provided on the lower structure, and has a structure on the upper surface. 1 a lower guide portion having a lower sliding surface formed in a V-shape convex downward along the horizontal direction; provided under the upper structure; provided under the upper structure; an upper guide portion having an upper sliding surface formed in an inverted V-shape that is convex upward along a second horizontal direction perpendicular to the first horizontal direction on a lower surface; the lower sliding surface and the upper sliding surface; the lower guide part and the first horizontal direction along the lower sliding surface; 2, a slider that is relatively displaceable in the horizontal direction, and the slider has a lower sliding part provided at a lower part and capable of sliding on the lower sliding surface, and a lower sliding part provided at an upper part and capable of sliding on the upper sliding surface. an upper sliding part that is capable of sliding on a moving surface; and an upper sliding part that is provided between the lower sliding part and the upper sliding part so that the lower sliding part and the upper sliding part can be moved relative to each other in a horizontal direction. A supporting laminated rubber part, a lower shear force transmission part that transmits shear force from the lower sliding part to the laminated rubber part, and an upper shear force transmission part that transmits shear force from the upper sliding part to the laminated rubber part. The laminated rubber part has a laminated rubber body, a lower joining member that is joined to the lower surface of the laminated rubber body and is capable of transmitting shear force to the laminated rubber body, and a lower joint member that is connected to the upper surface of the laminated rubber body. an upper joining member that is joined and capable of transmitting shear force to the laminated rubber main body; the lower shear force transmitting part has a disc shape with an axis in a vertical direction; and the lower sliding part and the lower joining member and transmits shear force between the lower sliding part and the lower joining member via an outer peripheral surface, and the upper shear force transmitting part has a disc shape with an axis in a vertical direction. , is disposed 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 the outer peripheral surface.

In the present invention, shear force is transmitted between the lower sliding part and the lower joining member via the outer circumferential surface of the disk-shaped lower shear force transmitting section, and the shear force is transferred via the outer circumferential surface of the disk-shaped upper shear force transmitting section. Shear force is transmitted between the upper sliding part and the upper joining member. Thereby, regardless of the sliding direction of the slider, the shear force can be transmitted smoothly without local stress concentration. Furthermore, the influence on the transmission of shear force due to rotation and twisting of the laminated rubber can be suppressed. As a result, in the present invention, shear force can be efficiently transmitted to the entire laminated rubber.

Further, in the seismic isolation mechanism according to the present invention, the lower shear force transmitting part has a lower side inserted into a round hole formed in the lower sliding part, and an upper side inserted into a round hole formed in the lower joint member. The upper shear force transmitting part may have an upper side inserted into a round hole formed in the upper sliding part, and a lower side inserted into a round hole formed in the upper joining member.

With such a configuration, the power can be transmitted through the outer circumferential surface of the lower shear force transmission section, the inner circumferential surface of the round hole formed in the lower sliding section, and the inner circumferential surface of the round hole formed in the lower joint member. Regardless of the sliding direction of the slider, shear force can be transmitted smoothly without local stress concentration. in the sliding direction of the slider through the outer circumferential surface of the upper shear force transmission section, the inner circumferential surface of the round hole formed in the upper sliding section, and the inner circumferential surface of the round hole formed in the upper joint member. Regardless of the situation, shear force can be transmitted smoothly without local stress concentration. Furthermore, the influence of rotation and twisting of the laminated rubber on the transmission of shear force can be suppressed.

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

With such a configuration, the maximum amount of deformation of the laminated rubber body remains within the elastic range, so that residual displacement can be prevented from occurring.

Further, in the seismic isolation mechanism according to the present invention, a coefficient of friction between the slider and the lower sliding surface and a coefficient of friction between the slider and the upper sliding surface are 0.15 or less, The shear elastic modulus of the laminated rubber body may be 0.4 N/mm ² or more and 0.8 N/mm ² or less.

With such a configuration, the load sliding acceleration at the top of the seismically isolated object can be suppressed to 500 cm/s ² or less, and seismic isolation displacement can be suppressed.

According to the present invention, it is possible to suppress the influence of rotation and twisting of the laminated rubber on the transmission of shear force.

1 is a diagram showing an automatic rack warehouse equipped with a seismic isolation mechanism according to an embodiment of the present invention. It is a perspective view of a seismic isolation mechanism. FIG. 3 is a diagram of the seismic isolation mechanism seen from above. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. 4 is a sectional view taken along line BB in FIG. 3. FIG. It is an exploded perspective view of a slider. It is a perspective view of a slider. It is a figure explaining the restoration characteristic of a seismic isolation mechanism. 2 is a diagram showing an analytical model, and a table showing the relationship between height, mass, and rigidity of the analytical model. This is a table showing seismic waves used for analysis. 3 is a graph showing the relationship between the friction coefficient and the maximum response acceleration at the top of the rack due to seismic wave 1. FIG. 7 is a graph showing the relationship between the friction coefficient and the maximum response acceleration at the top of the rack due to seismic waves 2. FIG. 3 is a graph showing the relationship between the friction coefficient and the maximum response acceleration at the top of the rack due to seismic waves 3. FIG. It is a graph showing the relationship between the friction coefficient and seismic isolation displacement due to seismic wave 1. It is a graph showing the relationship between the friction coefficient and seismic isolation displacement due to seismic wave 2. It is a graph which shows the relationship between the friction coefficient and seismic isolation displacement by seismic wave 3. 3 is a graph showing the relationship between the friction coefficient and the residual displacement of the bearing due to seismic wave 1. It is a graph showing the relationship between the friction coefficient and the residual displacement of the bearing due to seismic wave 2. It is a graph showing the relationship between the friction coefficient due to seismic wave 3 and the residual displacement of the bearing. It is a graph showing the relationship between the friction coefficient and deformation of laminated rubber due to seismic wave 1. It is a graph showing the relationship between the friction coefficient and deformation of laminated rubber due to seismic wave 2. It is a graph showing the relationship between the friction coefficient and the deformation of laminated rubber due to seismic waves 3.

Hereinafter, a seismic isolation mechanism according to an embodiment of the present invention will be described based on FIGS. 1 to 8.
As shown in FIG. 1, the seismic isolation mechanism 1 according to this embodiment is provided in a seismic isolation layer 13 between a lower structure 11 and an upper structure 12. A plurality of seismic isolation mechanisms 1 are provided in the seismic isolation layer 13. A plurality of base isolation mechanisms 1 provided in the base isolation layer 13 have the same configuration. The seismic isolation mechanism of this embodiment employs a tilted elastic sliding bearing.
In this embodiment, the lower structure 11 is assumed to be the floor of an automatic rack warehouse, and the upper structure 12 includes a seismic isolation pedestal 121 provided on the floor via a plurality of seismic isolation mechanisms 1, and It is assumed that a high-rise rack 122 is installed in the building.

As shown in FIG. 1, the seismic isolation mechanism 1 includes a lower guide section 2 fixed to the upper part of the lower structure 11 (see FIG. 1), and an upper part fixed to the bottom of the upper structure 12 (see FIG. 1). It has a guide part 3 and a slider 4 arranged between the lower guide part 2 and the upper guide part 3. In this embodiment, the lower guide part 2 is fixed to the floor surface of the automatic rack warehouse of the lower structure 11. The upper guide portion 3 is fixed to the lower surface of the seismic isolation frame 121 of the upper structure 12.

As shown in FIGS. 2 to 5, the lower guide part 2 includes a main body part 22 including a lower sliding surface 21 on which the slider 4 slides, and a main body part 22 that is connected to the lower part of the main body part 22 and attached to the lower structure 11. It has a fixing part 23 to be fixed.
The main body portion 22 is formed in a block shape that is an elongated substantially rectangular parallelepiped, and is arranged to extend in one horizontal direction (first horizontal direction). One horizontal direction is referred to as the X direction, and another horizontal direction (second horizontal direction) orthogonal to the one horizontal direction is referred to as the Y direction. As shown in FIG. 4, the upper surface of the main body portion 22 is a substantially V-shaped inclined surface whose substantially central portion in the X direction is convex downward. The upper surface of this main body portion 22 is the lower sliding surface 21. A bent portion approximately at the center of the lower sliding surface 21 is referred to as a lower bent portion 211. Further, among the lower sliding surfaces 21, one side in the X direction from the lower bent portion 211 is referred to as a first lower sliding surface 212, and the other side in the X direction from the lower bent portion 211 is referred to as a second lower sliding surface 213. It is written as.

The first lower sliding surface 212 and the second lower sliding surface 213 are each sloped 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 part 22. The lower slide plate 24 is made of stainless steel or the like.
As shown in FIGS. 2 and 5, both side surfaces (end surfaces on both sides in the Y direction) 221, 221 of the main body portion 22 are substantially vertical surfaces facing the Y direction, and a lower side slide plate 25 is provided. There is. The lower side slide plate 25 is made of stainless steel or the like.

The fixing part 23 is formed into a plate shape, and is joined to the lower surface of the main body part 22 with the plate surface facing a horizontal plane. In this embodiment, the fixing part 23 is formed in a substantially rectangular shape with larger dimensions in the X and Y directions than the main body part 22, and protrudes further than the main body part 22 in the X and Y directions. The fixing part 23 is fixed to the upper surface of the lower structure 11, that is, to the floor surface of the automatic rack warehouse.

As shown in FIG. 4, the upper guide part 3 includes a main body part 32 including an upper sliding surface 31 on which the slider 4 slides, and is connected to the upper part of the main body part 32 and fixed to the upper structure 12. It has a fixed part 33.
The main body portion 32 is formed in a block shape that is an elongated substantially rectangular parallelepiped, and is arranged to extend in the Y direction. The lower surface of the main body portion 32 is a substantially inverted V-shaped inclined surface whose substantially central portion in the Y direction is convex upward along the Y direction. The lower surface of this main body portion 32 is the upper sliding surface 31. A bent portion at approximately the center of the upper sliding surface 31 is referred to as an upper bent portion 311 . Further, among the upper sliding surfaces 31, one side in the Y direction from the upper bent portion 311 is referred to as a first upper sliding surface 312, and the other side in the Y direction from the upper bent portion 311 is referred to as a second upper sliding surface 313. It is written as.

The first upper sliding surface 312 and the second upper sliding surface 313 are each a flat inclined surface. 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 angle of inclination is the same value as the angle of inclination 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 part 32. The upper slide plate 34 is made of stainless steel or the like.
As shown in FIGS. 2 and 4, both side surfaces (end surfaces on both sides in the X direction) 321, 321 of the main body portion 32 are substantially vertical surfaces facing the X direction, and an upper side slide plate 35 is provided. . The upper side slide plate 35 is made of stainless steel or the like.

The fixing part 33 is formed into a plate shape, and is joined to the upper surface of the main body part 32 with the plate surface facing a horizontal plane. In this embodiment, the fixing part 33 is formed in a substantially rectangular shape with larger dimensions in the X and Y directions than the main body 32 and protrudes further than the main body 32 in the X and Y directions. The fixing part 33 is fixed to the lower surface of the upper structure 12, that is, the lower surface of the seismic isolation frame 121.

The lower guide part 2 and the upper guide part 3 have substantially the same form except for the fixed position and posture.
The lower guide part 2 and the upper guide part 3 are arranged to overlap with each other with a gap in the vertical direction, and the lower guide part 2 and the upper guide part 3 overlap in the vertical direction at an intersection 41 (see FIG. 3). ) the slider 4 is arranged.

As shown in FIGS. 6 and 7, the slider 4 includes a lower sliding part 5, an upper sliding part 6, a laminated rubber part 7, a lower shear force transmitting part 8 (see FIG. 6), and an upper part. It has a shear force transmission section 9 (see FIG. 6). The lower sliding portion 5 includes a lower contact surface 511 provided at the lower portion and capable of sliding on the lower sliding surface. The upper sliding portion 6 includes an upper contact surface 611 provided at the upper portion and capable of sliding 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 as to be relatively movable in the horizontal direction. The lower shear force transmission section 8 transmits shear force from the lower sliding section 5 to the laminated rubber section 7. The upper shear force transmission section 9 transmits shear force from the upper sliding section 6 to the laminated rubber section 7.

The lower sliding part 5 protrudes downward from both sides of the lower sliding part main body 51 disposed on the lower sliding surface 21 and the lower sliding part main body in the Y direction, and extends from the main body part 22 of the lower guide part 2. It has a pair of lower guide parts 52 arranged on both sides in the Y direction. The lower sliding portion 5 is made of, for example, steel.

The lower sliding portion main body 51 has a block shape with a substantially square planar shape when viewed from above. The lower surface of the lower sliding portion main body 51 is the lower contact surface 511. As shown in FIG. 4, the lower contact surface 511 is a substantially V-shaped inclined surface whose substantially central portion in the X direction is convex downward along the X direction. The bent portion of the lower contact surface 511 approximately at the center in the X direction is referred to as a lower bent portion 512. Among the lower contact surfaces 511, one side in the X direction relative to the lower bent portion 512 is referred to as a first lower contact surface 513, and the other side in the X direction than the lower bent portion 512 is referred to as a second lower contact surface 514. It is written as.

The first lower contact surface 513 and the second lower contact surface 514 are each a flat inclined surface. 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 angle of inclination is the same value as the angle of inclination of the first lower sliding surface 212 and the second lower sliding surface 213 with respect to the horizontal plane.

The first lower contact surface 513 and the second lower contact surface 514 are each provided with a sliding material 515 such as Teflon (registered trademark). The lower sliding part main body 51 is arranged on the lower sliding surface 21 (lower slide plate 24) of the lower guide part 2 via the sliding material 515. In this embodiment, the friction coefficient μ between the lower contact surface 511 and the lower sliding surface 21, that is, the friction coefficient μ between the lower slide plate 24 and the material 515 is 0.15 or more.
The upper surface of the lower sliding portion 5 is a horizontal surface. A recess 53 that opens upward is formed in the upper part of the lower sliding part 5 at the center in plan view. The shape of the recess 53 in plan view is circular.

The interval between the pair of lower guide parts 52, 52 is slightly larger than the dimension of the main body part 22 of the lower guide part 2 in the Y direction. Bearings 522, 522 are provided on inner surfaces 521, 521 of the pair of lower guide parts 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 part 22 of the lower guide part 2.

The upper sliding part 6 includes an upper sliding part main body 61 disposed below the upper sliding surface 31 and an upper sliding part main body 61 that protrudes upward from both sides of the upper sliding part main body in the X direction. It has a pair of upper guide parts 62 arranged on both sides in the X direction. The upper sliding portion 6 is made of, for example, steel.

The upper sliding portion main body 61 has a block shape with a substantially square planar shape when viewed from above. The upper surface of the upper sliding portion main body 61 is the upper contact surface 611. As shown in FIG. 5, the upper contact surface 611 is a substantially inverted V-shaped inclined surface whose substantially central portion in the Y direction is convex upward along the Y direction. The bent portion of the upper contact surface 611 approximately at the center in the Y direction is referred to as an upper bent portion 612. Among the upper contact surfaces 611, one side in the Y direction relative to the upper bent portion 612 is referred to as a first upper contact surface 613, and the other side in the Y direction than the upper bent portion 612 is referred to as a second upper contact surface 614. It is written as.

The first upper contact surface 613 and the second upper contact surface 614 are each a flat inclined surface. 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 angle of inclination is the same value as the angle of inclination of the first upper sliding surface 312 and the second upper sliding surface 313 with respect to the horizontal plane.

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 portion main body 51 is disposed below the upper sliding surface 31 (upper slide plate 34) of the upper guide portion 3 via a sliding member 615. In this embodiment, the friction coefficient μ between the upper contact surface 611 and the upper sliding surface 31, that is, the friction coefficient 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 surface. A recess 63 that opens downward is formed in the lower part of the upper sliding part 6 at the center in a plan view. The shape of the recess 63 in plan view is circular.

The distance between the pair of upper guide parts 62, 62 is slightly larger than the dimension of the main body part 32 of the upper guide part 3 in the X direction. Bearings 622, 622 are provided on inner surfaces 621, 621 of the pair of upper guide parts 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 part 32 of the upper guide part 3.
The lower sliding part 5 and the upper sliding part 6 have substantially the same form except for the position and posture in which they are arranged. The lower sliding part 5 and the upper sliding part 6 are arranged to overlap in the vertical direction with the laminated rubber part 7 in between.

As shown in FIGS. 4 to 6, the laminated rubber section 7 includes a laminated rubber main body 71, a lower joining member 72, and an upper joining member 73. The lower joining member 72 is joined below the laminated rubber main body 71. The upper joining member 73 is joined onto the laminated rubber main body 71.
The laminated rubber main body 71 is a laminated rubber having 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 main body 71 connects the lower joining member 72 and the upper joining member 73 so as to be relatively movable in the horizontal direction. The laminated rubber main body 71 has a substantially square shape in plan view.
The lower joining member 72 and the upper joining member 73 each have a flat plate shape with a square plate surface. The lower joining member 72 and the upper joining member 73 are made of, for example, steel, stainless steel, or the like. The lower joining member 72 and the upper joining member 73 are arranged in a posture such that their plate surfaces are horizontal planes. A recess 721 that opens downward is formed in the lower part of the lower joining member 72 at the center in a plan view. The shape of the recess 721 in plan view is circular. A recess 731 that opens upward is formed in the upper part of the upper joint member 73 at the center in a plan view. The shape of the recess 731 in plan view is circular. The lower joining member 72 and the upper joining member 73 have substantially the same form except for the position and posture in which they are arranged.
The circles in the plan view of each 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 part 5, and the recess 63 of the upper sliding part 6 have substantially the same diameter.

The laminated rubber main body 71, the lower joint member 72, and the upper joint member 73 have substantially the same shape in plan view, and are stacked in the order of the lower joint member 72, the laminated rubber main body 71, and the upper joint member 73 from the bottom to the top. Placed. The upper surface of the lower joining member 72 and the lower surface of the laminated rubber main body 71 are joined, and the lower surface of the upper joining member 73 and the upper surface of the laminated rubber main body 71 are joined. The recess 721 of the lower joining member 72 and the recess 731 of the upper joining member 73 are arranged at positions that overlap in the vertical direction.

The lower shear force transmission section 8 and the upper shear force transmission section 9 are disk-shaped. The lower shear force transmission section 8 and the upper shear force transmission section 9 are formed of, for example, a steel plate. The lower shear force transmission section 8 and the upper shear force transmission section 9 have substantially the same shape, and are arranged so that the plate surfaces thereof are horizontal. The outer shapes of the lower shear force transmitting part 8 and the upper shear force transmitting part 9 are the recess 721 of the lower joint member 72, the recess 731 of the upper joint member 73, the recess 53 of the lower sliding part 5, and the recess of the upper sliding part 6. 63. The inner diameter is approximately the same as that of 63.

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 from the lower side to the upper side, the lower sliding part 5, the laminated rubber part 7, and the upper sliding part They are arranged one on top of the other in the order of 6.
A lower shear force transmission section 8 is arranged between the lower sliding section 5 and the laminated rubber section 7. The lower shear force transmitting part 8 has its lower side inserted into the recess 53 of the lower sliding part 5, and its upper side inserted into the recess 721 of the lower joining member 72 of the laminated rubber part 7. An upper shear force transmission section 9 is arranged between the upper sliding section 6 and the laminated rubber section 7. The upper shear force transmitting part 9 has its upper side inserted into the recess 63 of the upper sliding part 6, and its lower side inserted into the recess 731 of the upper joint member 73 of the laminated rubber part 7.

The lower sliding part main 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 each of the four corners. The upper sliding part main 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 each of the four corners.

Such a slider 4 has an outer circumferential surface 81 of the disk-shaped lower shear force transmitting portion 8, an inner circumferential surface 531 of the recess 53 of the lower sliding portion 5, and a recess 721 of the lower joint member 72 of the laminated rubber portion 7. Shear force is transmitted between the lower sliding part and the lower joining member via the inner peripheral surface 722. The upper sliding portion passes through the outer circumferential surface 91 of the disk-shaped upper shear force transmission portion 9, the inner circumferential surface 631 of the recess 63 of the upper sliding portion 6, and the inner circumferential surface 732 of the recess 731 of the upper joint member 73 of the laminated rubber portion 7. Shear force is transmitted between the moving part and the upper joining member.

In the laminated rubber main body 71 of the laminated rubber part 7, the lower sliding part 5 and the upper sliding part 6 are relatively displaced in the horizontal direction, and the relative displacement in the horizontal direction is caused by the lower shear force transmitting part 8 and the upper shear force transmitting part. When the lower joint member 72 and the upper joint member 73 are relatively displaced in the horizontal direction by transmitting the force 9, the rubber portion is elastically deformed following the relative displacement between the lower joint member 72 and the upper joint member 73. The lower sliding portion 5 and the upper sliding portion 6 are restored to their original positions by the restoring force (elastic sliding restoring force) of the elastically deformed rubber portion.

In this embodiment, the shear elastic modulus G of the laminated rubber main body 71 is set to 0.4 N/mm ² or more and 0.8 N/mm ² or less.
The optimal combination to reduce the load sliding acceleration at the top of the high-rise rack 122 to 500 cm/s ² or less and to keep the seismic isolation displacement small is one in which 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 factor S1 of the laminated rubber body 71 is set to S1>20, the secondary shape factor S2 of the laminated rubber body 71 is set to S2≧5, and the maximum deformation of the laminated rubber body 71 is determined by the total rubber thickness of the laminated rubber body 71. (n×tr) or less.
The primary shape factor S1 of the laminated rubber main body 71 is an index representing the vertical rigidity of the laminated rubber, and is expressed as S1=a×b/(2×(a+b)×tr). The quadratic shape factor S2 of the laminated rubber body 71 is an index representing the horizontal stability of the laminated rubber, and is expressed as S2=min(a or b)/(n×tr). In the above formula, a and b are the side length dimensions 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 dimension of one layer of rubber in the laminated rubber body 71. It is.

In the seismic isolation mechanism 1 having such a configuration, when an earthquake occurs and the lower structure 11 and the upper structure 12 undergo relative displacement in the horizontal direction, the lower guide part 2 fixed to the lower structure 11 and the upper structure 12 The laminated rubber part 7 deforms following the relative displacement with the upper guide part 3 fixed to the slider 4, and the slider 4 slides on the lower sliding surface 21 and the upper sliding surface 31.

In the initial state (normal state) of the seismic isolation mechanism 1, as shown in FIGS. 2 to 5, the laminated rubber part 7 is not deformed, and the slider 4 is in the original position relative to the lower guide part 2 and the upper guide part 3. placed in position. In the slider 4 placed in the original position, the first lower contact surface 513 is in contact with the first lower sliding surface 212 of the lower guide section 2, and the second lower contact surface 514 is in contact with the first lower sliding surface 212 of the lower guide section 2. 2, the first upper contact surface 613 contacts the first upper sliding surface 312 of the upper guide part 3, and the second upper contact surface 614 contacts the second upper part of the upper guide part 3. It comes into contact with the sliding surface 313.

When the slider 4 moves from the original position to one side in the X direction (left side in FIG. 4) with respect to the lower guide portion 2, the first lower contact surface 513 contacts the first lower sliding surface 212. However, the second lower sliding surface 21 slides up the first lower sliding surface 212 while the second lower contact surface 514 is spaced apart from the second lower sliding surface 213 . When the slider 4 moves from the original position to the other side in the X direction (the right side in FIG. 4) with respect to the lower guide portion 2, the second lower contact surface 514 comes into contact with the second lower sliding surface 213. However, the lower sliding surface 21 slides up the second lower sliding surface 213 while the first lower contact surface 513 is spaced apart from the first lower sliding surface 212 .

Further, when the slider 4 moves from the original position to one side in the Y direction (left side in FIG. 5) with respect to the upper guide portion 3, the first upper contact surface 613 comes into contact with the first upper sliding surface 312. However, the second upper contact surface 614 slides on the upper sliding surface 31 down the first upper sliding surface 312 while being spaced apart from the second upper sliding surface 313 . When the slider 4 moves from the original position to the other side in the Y direction (the right side in FIG. 5) with respect to the upper guide part 3, the second upper contact surface 614 comes into contact with the second upper sliding surface 313. However, the upper sliding surface 31 slides down the second upper sliding surface 313 with the first upper contact surface 613 spaced apart from the first upper sliding surface 312 .

In this way, the height of the slider 4 changes as it moves up and down relative to the lower guide section 2 and the upper guide section 3. However, in this embodiment, since each of the plurality of base isolation mechanisms 1 provided in the base isolation layer 13 has the same inclination angle θ, an earthquake occurs and the lower guide part 2 and the upper guide part 3 Even if the seismic isolation mechanisms 1 are relatively displaced in the horizontal direction, the upper ends of each of the seismic isolation mechanisms 1 are at the same height, and the lower ends of each of the seismic isolation mechanisms 1 are arranged at the same height.
Thereby, even if the lower structure 11 and the upper structure 12 are relatively displaced in the horizontal direction, the upper structure 12 is maintained horizontally.

In the seismic isolation mechanism 1, when the slider 4 and the lower guide part 2 are displaced relative to each other in the X direction, the slider 4 is displaced relative to the lower guide part 2 such that it moves up the lower sliding surface 21 of the lower guide part 2. Therefore, the relative displacement between the slider 4 and the lower guide portion 2 is accumulated as potential energy, which becomes a restoring force (tilt restoring force) for restoring the slider 4 to its original position. When the slider 4 and the upper guide part 3 are displaced relative to each other in the Y direction, the upper guide part 3 is displaced relative to the slider 4 so as to go up the slope of the upper contact surface 611 of the slider 4. The relative displacement between the slider 4 and the upper guide portion 3 is accumulated as potential energy, and becomes a restoring force (tilt restoring force) for restoring the slider 4 to its original position.
When the vertical load acting on the upper guide portion 3 is W, the tilt restoring force (horizontal force) F is expressed as F=Wtanθ, where the tilt angle θ with respect to the horizontal plane is set.

In this embodiment, when the relative displacement between the lower structure 11 and the upper structure 12 is small, only the laminated rubber main body 71 is deformed, and the slider 4 is moved between the lower sliding surface 21 and the upper sliding surface 21. If the relative displacement between the upper structure 12 and the lower structure 11 increases without sliding on the surface 31, and the horizontal displacement of the laminated rubber body 71 with respect 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.

FIG. 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 a slip occurs is generally larger than the tilt restoring force Wtanθ, and the combination of both becomes the restoring force characteristic of the seismic isolation mechanism 1.

Verification was conducted regarding the seismic isolation effect of an automatic rack warehouse equipped with the seismic isolation mechanism 1 according to this embodiment.
The analysis target is an automated rack warehouse with a height of 28 m. Figure 9 shows the analytical model, its height, mass, and rigidity model. The mass W of the upper structure is 1438683 kg. Below, the seismic isolation mechanism 1 according to this embodiment may be referred to as a "slanted elastic sliding bearing".
The specifications of the seismic isolation mechanism 1 (tilted elastic sliding bearing) are as follows.
The friction coefficient μ (10 types) and the inclination angle are 1.5°.
The shear stiffness of laminated rubber is shown by the formula below.
krb=W×9.8×G/(σ×trb)
here,
G: Shear rigidity of rubber σ: Surface pressure of laminated rubber (=5.86N/mm ² )
trb: Natural rubber layer thickness (=40mm)
9.8: Gravitational acceleration (m/s ² )
Primary shape factor S1=20
Quadratic shape factor S2=8
shall be.

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

Figures 11 to 13 show the maximum response acceleration at the top of the rack for each seismic wave. It can be confirmed that the 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 the seismic isolation mechanism 1 (inclined elastic sliding bearing) can reduce the maximum response acceleration at the top of the rack compared to the inclined sliding bearing + TMD.
A comparison of the acceleration reduction effects reveals the following.
Shear modulus of elasticity G of the laminated rubber body: G3>G4>G6>G8>G10
Friction coefficient μ: 0.01>0.03>0.05>0.07>0.09>0.1>0.15>0.2>0.25>0.3
In the seismic isolation mechanism 1 (inclined elastic sliding bearing), in order to reduce the load sliding acceleration to 500 cm/ ^s2 or less, the friction coefficient μ should be approximately 0.15 or less, and the shear elastic coefficient G of the laminated rubber body should be set to G3, This is possible by setting the shear elastic coefficient G of the laminated rubber body to G3, G4, G6, and G8 if the friction coefficient μ is set to about 0.1 or less.

Figures 14 to 16 show the seismic isolation displacement for each seismic wave. Comparing the magnitude of seismic isolation displacement, it can be seen that the following is true.
Shear modulus of elasticity G of the laminated rubber body: G3>G4>G6>G8>G10
Friction coefficient μ: After μ>0.1 to 0.15, it can be confirmed that the increase in seismic isolation displacement of G6, G8, and G10 is smaller than that of G3 and G4.

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

Figures 20 to 22 show the deformation of rubber depending on seismic waves. In FIGS. 20 to 22, the deformation of the rubber is expressed as a ratio to a rubber thickness of 40 mm. It can be confirmed that the ratio of rubber deformation/rubber thickness increases as the friction coefficient μ increases. It can be confirmed that the deformation of the rubber becomes smaller as the shear modulus G becomes larger. In order to suppress elastic displacement, the ratio of rubber deformation/rubber thickness needs to be about 2.5 times or less, so it can be confirmed that the friction coefficient μ needs to be 0.15 or less.

From the above analysis, in order to suppress the maximum response acceleration (load sliding acceleration) at the top of the rack to 500 cm/s ² or less, it is preferable that the conditions for the seismic isolation mechanism 1 (tilted elastic sliding bearing) be as follows.
The shear elastic modulus G of the laminated rubber body is set to G4, G6, and G8, and the friction coefficient μ is set to 0.15 or less. By doing so, residual displacement can be suppressed, and the maximum deformation of the rubber remains at about 2.5 times the rubber thickness.
The optimal combination to suppress the maximum response acceleration (load sliding acceleration) at the top of the rack to 500 cm/ ^s2 or less and to suppress the seismic isolation displacement is to set the shear elastic coefficient G of the laminated rubber body to G6, and the friction coefficient μ. This is a combination in which the value is 0.1.

Next, the action and effect of the seismic isolation mechanism according to this embodiment will be explained.
In the seismic isolation mechanism 1 according to the present embodiment, the slider 4 includes the outer circumferential surface 81 of the disk-shaped lower shear force transmission section 8, the inner circumferential surface 531 of the recess 53 of the lower sliding section 5, and the lower part of the laminated rubber section 7. Shearing force is transmitted between the lower sliding portion and the lower joining member via the inner circumferential surface 722 of the recess 721 of the joining member 72 . The slider 4 includes an outer circumferential surface 91 of the disk-shaped upper shear force transmission section 9, an inner circumferential surface 631 of the recess 63 of the upper sliding section 6, and an inner circumferential surface of the recess 731 of the upper joint member 73 of the laminated rubber section 7. Shearing force is transmitted between the upper sliding portion 6 and the upper joining member 73 via 732 . Therefore, regardless of the sliding direction of the slider 4, the shear force can be transmitted smoothly without local stress concentration. Thereby, the influence of rotation and twisting of the laminated rubber body 71 on the transmission of shear force can be suppressed.
Since the seismic isolation mechanism 1 of this embodiment employs a tilted elastic sliding bearing, it is difficult to cause twisting even when there is an uneven load or load fluctuation peculiar to a rack warehouse, and it can exhibit a stable response reduction effect.

In the seismic isolation mechanism 1 according to this embodiment, the maximum amount of deformation of the laminated rubber body 71 is 2.5 times or less the rubber layer thickness of the laminated rubber body 71. With such a configuration, the maximum amount of deformation of the laminated rubber main body 71 remains within the elastic range, so that residual displacement can be prevented from occurring.

In the seismic isolation mechanism 1 according to the present embodiment, the friction coefficient μ between the slider 4 and the lower sliding surface 21 and the friction coefficient μ between the slider 4 and the upper sliding surface 31 are each 0.15 or less. The shear modulus G of the laminated rubber body is 0.4 N/mm ² or more and 0.8 N/mm ² or less. With such a configuration, the load sliding acceleration at the top of the seismically isolated object can be suppressed to 500 cm/s ² or less, and seismic isolation displacement can be suppressed. Therefore, by employing the seismic isolation mechanism 1 of this embodiment, it is possible to install a high-rise automatic rack warehouse even in a narrow factory room.

Since tilted elastic sliding bearings have no natural period, they are not affected by the stiffness of the bearing and can handle seismic waves with predominant long-period components and seismic waves with predominant short-period components such as pulses.

Although the 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 thereof.
For example, in the above embodiment, the proposal is made for a high-rise automated rack warehouse. It can also be applied to low-rise automatic rack warehouses and buildings.

In the embodiment described above, the disc-shaped lower shear force transmitting 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 transmitting 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. On the other hand, the disc-shaped lower shear force transmission part 8 is joined to either the lower sliding part 5 or the lower joint member 72 of the laminated rubber part 7, and is inserted into the recess formed in the other, and the disc-shaped lower shear force transmitting part 8 The upper shear force transmitting 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 a recess formed in the other.

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

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

The Sustainable Development Goals (SDGs) are among the 17 international goals adopted at the United Nations Summit in September 2015.
The seismic isolation mechanism according to this embodiment can contribute to achieving, for example, the goal of "11. Creating cities where people can continue to live" among the 17 goals of the SDGs.

1 Seismic isolation mechanism 2 Lower guide part 3 Upper guide part 4 Slider 5 Lower sliding part 6 Upper sliding part 8 Lower shear force transmission part 9 Upper shear force transmission part 7 Laminated rubber part 11 Lower structure 12 Upper structure 13 Seismic isolation layer 21 Lower sliding surface 31 Upper sliding surface 53 Recess 63 Recess 71 Laminated rubber main body 72 Lower joining member 73 Upper joining member 81 Outer peripheral surface 91 Outer peripheral surface 511 Lower contact surface 611 Upper contact surface 721 Recess 731 Recess

Claims (4)

Provided between a lower structure and an upper structure that can be relatively displaced in the horizontal direction,
a lower guide portion provided on the lower structure and having a lower sliding surface formed in a V-shape convex downward along a first horizontal direction on the upper surface;
an upper guide portion provided under the upper structure and having an upper sliding surface formed in an inverted V-shape that is convex upward along a second horizontal direction perpendicular to the first horizontal direction on the lower surface; ,
is disposed between the lower sliding surface and the upper sliding surface, is movable relative to the lower guide part in the first horizontal direction along the lower sliding surface, and is disposed on the upper sliding surface. along the upper guide portion and the second horizontally movable slider,
The slider is
a lower sliding part provided at the lower part and capable of sliding on the lower sliding surface;
an upper sliding part provided at the upper part and capable of sliding on the upper sliding surface;
a laminated rubber part that is provided between the lower sliding part and the upper sliding part and supports the lower sliding part and the upper sliding part so that they can move relative to each other in a horizontal direction;
a lower shear force transmission section that transmits shear force from the lower sliding section to the laminated rubber section;
an upper shear force transmission part that transmits shear force from the upper sliding part to the laminated rubber part,
The laminated rubber part is
A laminated rubber body,
a lower joining member that is joined to the lower surface of the laminated rubber body and is capable of transmitting shear force to the laminated rubber body;
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 transmitting part has a disc shape with an axis extending in the vertical direction, and is arranged between the lower sliding part and the lower joining member, and is connected to the lower sliding part and the lower joining member via an outer peripheral surface. transmits shear force between
The upper shear force transmission part has a disc shape with an axis extending in the vertical direction, and is arranged between the upper sliding part and the upper joining member, and connects the upper sliding part and the upper joining member via the outer peripheral surface. A seismic isolation mechanism that transmits shear force between The lower shear force transmission part has a lower side inserted into a round hole formed in the lower sliding part, and an upper side inserted into a round hole formed in the lower joint member,
The upper shear force transmitting part has an upper side inserted into a round hole formed in the upper sliding part, and a lower side inserted into a round hole formed in the upper joint member. Earthquake mechanism. The seismic isolation mechanism according to claim 1 or 2, wherein the maximum deformation amount of the laminated rubber body is 2.5 times or less the thickness of the rubber layer of the laminated rubber body. 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 seismic isolation mechanism according to claim 1 or 2, wherein the shear elastic modulus of the laminated rubber body is 0.4 N/mm ² or more and 0.8 N/mm ² or less.

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