JP6349472B1 - Slider for sliding seismic isolation device and sliding seismic isolation device - Google Patents

Abstract

An object of the present invention is to provide a predetermined surface pressure to suppress an increase in a friction coefficient, obtain a seismic isolation effect by a sliding seismic isolation device, and suppress bending stress generated in a slider as much as possible, thereby prematurely wearing a sliding material. To provide a slider for a sliding seismic isolation device and a sliding seismic isolation device capable of suppressing variations in friction coefficient.
A slider for a steel sliding seismic isolation device, which is disposed between an upper rod 20A and a lower rod 20B having a sliding surface having a curvature, and includes an upper surface 1a and a lower surface 1b having a curvature. 10. The upper surface 1a and the lower surface 1b are provided with recesses 2a and 2b. The recesses 2a and 2b are in the form of counterbore holes and in the form of through holes 2e.
[Selection] Figure 4

Description

  The present invention relates to a slider for a sliding seismic isolation device and a sliding seismic isolation device.

  In Japan, an earthquake-prone country, there are various seismic resistances for various structures such as buildings, bridges, elevated roads, and detached houses. Technology, seismic isolation technology and seismic control technology have been developed and applied to various structures. In particular, seismic isolation technology is a technology that reduces the seismic force that enters the structure itself, so that the vibration of the structure during an earthquake is effectively reduced. To outline this seismic isolation technology, an isolation device is interposed between the foundation and the upper structure, which are the lower structures, to reduce the transmission of the foundation vibration due to the earthquake to the upper structure, and to reduce the vibration of the upper structure. To ensure structural stability. In addition, this seismic isolation device is effective not only at the time of an earthquake but also in reducing the influence on the upper structure of traffic vibration that always acts on the structure.

  There are various types of seismic isolation devices, such as a laminated rubber bearing device with a lead plug, a high damping laminated rubber bearing device, a device combining a laminated rubber bearing and a damper, and a sliding seismic isolation device. The general structure of the seismic isolation device will be described. The upper and lower heels having a sliding surface having a curvature, and the upper and lower heels are arranged between the upper and lower heels. And a slider having an upper surface and a lower surface having the same curvature as each of the ridges. The sliding seismic isolation device is sometimes referred to as a vertical spherical sliding type seismic isolation device or a double concave type seismic isolation device. In a sliding seismic isolation device, the performance of the upper and lower armatures is governed by the friction coefficient between the slider and the friction force generated by multiplying the friction coefficient by the loaded load (axial force). The

By the way, in the sliding seismic isolation device via Teflon (registered trademark), the reference surface pressure of Teflon (registered trademark) is 20 N / mm ² (20 MPa). When the weight increases, the size of the sliding seismic isolation device has to be increased in order to obtain a sliding seismic isolation device having a plane size suitable for this load. For this reason, cost competitiveness is lower than that of different types of seismic isolation devices such as laminated rubber seismic isolation devices, resulting in lower usage frequency.

The friction coefficient of the sliding seismic isolation device increases as the surface pressure decreases. Since the seismic isolation effect by the sliding seismic isolation device becomes difficult to obtain when the friction coefficient increases, the radius of the slider is designed so that the surface pressure increases according to the axial force. For example, a high-performance sliding seismic isolation device having a slider that realizes a surface pressure of 60 N / mm ² (60 MPa) has been proposed. Specifically, the upper and lower rods having a sliding surface having a curvature, and between the upper and lower rods, a columnar steel made of an upper surface and a lower surface having a curvature in contact with each flange. A sliding seismic isolation device composed of a slider. A double woven fabric layer composed of PTFE fibers and fibers having higher tensile strength than PTFE fibers is provided on the upper and lower surfaces of the slider (see, for example, Patent Document 1).

Japanese Patent No. 5521096

According to the sliding seismic isolation device described in Patent Document 1, it is possible to provide a sliding seismic isolation device having high seismic isolation performance against a surface pressure of about 60 N / mm ² . By the way, when the sliding seismic isolation device described in, for example, Patent Document 1 is applied to a lightweight structure, it can withstand a surface pressure of 60 N / mm ² , so that the slider area can be reduced. On the other hand, the surface pressure (or bending stress) acting on the slider when the slider is slid is the average stress obtained by dividing the axial force acting on the slider by the area of the slider, and the upper and lower It is the total value of the increased stress caused by the bending moment generated when sliding between the two. As the outer diameter of the slider is reduced, the section modulus of the slider also decreases, so the increased stress caused by the bending moment increases, and the bending stress that is the sum of the average stress and the increased stress (especially the upper surface of the slider) And end stress at the lower surface). And when bending stress (especially edge stress) increases, problems such as early wear of the sliding material adhered to the upper and lower surfaces of the slider, and variations in the coefficient of friction due to non-constant slider surface pressure. Such a problem is concerned.

  The present invention has been made in view of the above-mentioned problems, and ensures a predetermined surface pressure to suppress an increase in the coefficient of friction, obtains a seismic isolation effect by the sliding seismic isolation device, and allows bending stress generated in the slider to be as low as possible. An object of the present invention is to provide a slider and a sliding seismic isolation device for a sliding seismic isolation device that can suppress the initial wear of the sliding material and suppress variations in the friction coefficient.

In order to achieve the above object, one aspect of a slider for a sliding seismic isolation device according to the present invention is disposed between an upper arm and a lower arm with a sliding surface having a curvature, and has an upper surface and a lower surface having a curvature. A slider for a steel sliding seismic isolation device,
The upper surface and the lower surface include a recess.

According to this aspect, since both the upper surface and the lower surface of the slider are provided with the recesses, for example, the area of the upper surface and the lower surface of the slider can be reduced as desired without reducing the outer diameter of the slider. Therefore, even when the axial force acting on the slider is small, the surface pressure of the slider can be adjusted to a predetermined surface pressure while maintaining the outer diameters of the upper and lower surfaces of the slider by adjusting the area of the recess. . In adjusting the surface pressure, for example, it is not necessary to reduce the outer diameter of the slider. Therefore, it is possible to suppress a decrease in the section modulus of the slider as compared with the case where the outer diameter of the slider is reduced. By suppressing the decrease in the cross-section constant of this slider, it is possible to suppress the increased stress caused by the bending moment, to suppress the early wear of the sliding material when the sliding material is fixed on the slider surface, and to the friction coefficient of the sliding seismic isolation device The variation of can be suppressed. Further, since the slider is made of steel, it can sufficiently resist the surface pressure of about 60 N / mm ^{2, and} can exhibit an excellent seismic isolation effect while maintaining the friction coefficient at a predetermined low value. .

  Further, according to another aspect of the slider for a sliding seismic isolation device according to the present invention, the upper surface and the lower surface have a circular shape in plan view, both have the same area, and both have the same recess area. It is characterized by being.

  According to this aspect, the remaining area excluding the area of the recess can be set to the same area among the areas of the upper surface and the lower surface of the slider. Here, regarding the configuration in which “both areas are the same”, since the upper surface and the lower surface of the slider have curvature, the areas of the upper surface and the lower surface have the same area in plan view, in other words, This means that the projected area with respect to the plane is the same. In addition, the shape of the concave portion in plan view is not particularly limited, but may be a polygon similar to the upper surface and the lower surface, or a polygon such as a square or a rectangle. However, the slider has a circular shape in plan view so that any end part of the slider can counter the same degree against the increased stress due to the bending moment while the slider slides freely in the direction of 360 degrees between the upper and lower eyelids. It is preferable that the recess is provided at the center of the upper and lower surfaces of the slider.

  In another aspect of the slider for a sliding seismic isolation device according to the present invention, the recess is a counterbore.

  According to this aspect, although the slider has concave portions on the upper surface and the lower surface, since the concave portion is a counterbore, a solid portion of the slider exists between the upper and lower counterbore holes. Therefore, the solid part can suppress the decrease in the rigidity of the slider due to the concave part.

  Further, in another aspect of the slider for a sliding seismic isolation device according to the present invention, the concave portion is a through hole extending from the upper surface to the lower surface.

  According to this aspect, since the concave portion is a through hole, the material for forming the slider can be reduced as much as possible, and the weight of the slider can be reduced as much as possible. Further, since the through hole extends from the upper surface to the lower surface of the slider, the through hole has a recess (through hole) at the same position on the upper surface and the lower surface. As described above, it is preferable that the through hole is provided at the center position of the slider so that the axis of the through hole and the axis of the slider are coaxial.

  Further, in another aspect of the slider for the slip isolation device according to the present invention, the planar view shape of the upper surface and the lower surface and the planar view shape of the recess are both circular, and satisfy the following formula (A): It is characterized by.

本態様によれば、スライダーの高さに応じて式（Ａ）に基づいて凹部の孔径を設定することにより、曲げモーメントに起因するスライダーの端部応力を可及的に抑制することができる。既述するように、スライダーがスライドしている際にスライダーの特に端部に生じる端部応力σ_Ｖは、スライダーに作用する軸力に起因して常時生じている平均応力σ_Ｏと、曲げモーメントに起因する増加応力σ_Bの合計値となる。本発明者等によれば、スライダー本体の摩耗やスライダーの上面及び下面に接着等されている滑り材の摩耗を防止するには、σ_Ｖ／σ_Ｏを１．１に抑えることが重要であるとの知見が得られている。上式（Ａ）は、σ_Ｖ／σ_Ｏ≦１．１を充足する式となっている。スライダーの設計としては、まず、構造物の規模や高さ制限等からスライダーの高さが設定されるのが一般的である。従って、スライダーの高さＨが設定され、次にスライダーの外径Ｄ１が設定されてスライダーの寸法が設定された後、上式（Ａ）を充足するＤ２を設定することにより、スライダーの摩耗を抑制しながら、所定の面圧を確保して摩擦係数の増加を抑制し、滑り免震装置による免震効果を得ることができる。

According to this aspect, the end stress of the slider caused by the bending moment can be suppressed as much as possible by setting the hole diameter of the recess based on the formula (A) according to the height of the slider. As described above, when the slider slides, the end stress σ _V generated particularly at the end of the slider is the average stress σ _O always generated due to the axial force acting on the slider and the bending moment. This is the total value of the increased stress σ _B caused by. According to the inventors of the present invention, it is important to suppress σ _V / σ _O to 1.1 in order to prevent the wear of the slider body and the wear of the sliding material bonded to the upper and lower surfaces of the slider. The knowledge is obtained. The above formula (A) is a formula that satisfies σ _V / σ _O ≦ 1.1. As a design of the slider, first, the height of the slider is generally set based on the scale of the structure, the height restriction, and the like. Therefore, after the slider height H is set, and then the slider outer diameter D1 is set and the slider dimensions are set, the slider wear is reduced by setting D2 that satisfies the above equation (A). While suppressing, it is possible to secure a predetermined surface pressure to suppress an increase in the coefficient of friction, and to obtain the seismic isolation effect by the sliding seismic isolation device.

Further, in another aspect of the slider for a sliding seismic isolation device according to the present invention, the upper surface and the lower surface of the slider are made of a double woven fabric comprising PTFE fibers and fibers having higher tensile strength than the PTFE fibers. The sliding material is fixed,
The sliding material is characterized in that the PTFE fiber is disposed on the sliding surface side of the upper and lower eyelids.

According to this aspect, the sliding material made of double woven fabric is fixed to the upper and lower surfaces of the slider, and the PTFE fibers are arranged on the sliding surface side of the upper and lower ridges in the sliding material, so that 60 N / The sliding performance of the sliding seismic isolation device under a high surface pressure of about mm ² is improved. Moreover, by applying a sliding material made of a double woven fabric containing PTFE fibers, PTFE fibers having a relatively low tensile strength and therefore low crush resistance when subjected to a load are repeatedly vibrated (applied) under pressure. It tends to collapse when subjected to pressure sliding force. However, the crushed PTFE fiber has higher tensile strength than that, and therefore, by staying in the highly crushed fiber, at least a part of it can face the sliding surface of the upper heel and lower heel, Good slidability of the PTFE fiber can be enjoyed. This leads to an improvement in the durability of the sliding seismic isolation device having the desired seismic isolation performance.

One aspect of the sliding seismic isolation device according to the present invention is an upper arm and a lower arm with a sliding surface having a curvature,
The slider includes an upper surface having a curvature and a lower surface.

  According to this aspect, since the sliding seismic isolation device has the slider of the present invention, even when the axial force acting on the slider is small, a predetermined surface pressure can be secured and high seismic isolation performance can be exhibited. The bending stress (end portion stress) generated particularly at the end portion of the slider can be suppressed as much as possible, and wear of the slider can be suppressed.

  As can be understood from the above description, according to the slider and the slip isolation device of the present invention, the increase in the coefficient of friction against the predetermined high surface pressure is suppressed, and the excellent isolation effect is achieved. Can be obtained. Moreover, the bending stress which arises in a slider can be suppressed as much as possible, and the early wear of a slider and the dispersion | variation in the friction coefficient of a sliding seismic isolation device can be suppressed.

It is a perspective view of the slider main body which forms the slider which concerns on 1st Embodiment. It is the II-II arrow line view of FIG. 1, Comprising: It is a longitudinal cross-sectional view of a slider main body. It is an arrow view of the III direction of FIG. 1, Comprising: It is a top view of a slider main body. It is a perspective view of a slider concerning a 1st embodiment. It is a top view of the modification of a slider main body. It is a top view of the modification of a slider main body. It is a perspective view of the slider main body which forms the slider which concerns on 2nd Embodiment. It is a VII-VII arrow line view of Drawing 6, and is a longitudinal section of a slider main part. It is a perspective view of the slider which concerns on 2nd Embodiment. It is a disassembled perspective view of the sliding seismic isolation apparatus which concerns on embodiment. It is a longitudinal cross-sectional view of a sliding seismic isolation device. It is a figure explaining the calculation method of the height of a slider. It is a figure which shows the experimental result regarding the surface pressure dependence of the friction coefficient of a sliding seismic isolation device. It is a figure which shows the calculation result regarding the area change rate of a slider and the section modulus change rate of a slider when changing the hole diameter of a recessed part. It is a figure explaining one design example. It is a figure explaining one design example. It is a figure which shows the calculation result for specifying the ratio range of the optimal hole diameter of a recessed part, and the outer diameter of a slider. It is a figure which shows the ratio range of the hole diameter of an optimal recessed part, and the outer diameter of a slider.

  Hereinafter, a slider and a sliding seismic isolation device according to an embodiment will be described with reference to the accompanying drawings. In addition, in this specification and drawings, about the substantially same component, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[Slider according to the first embodiment]
First, an example of a slider body that forms the slider according to the first embodiment will be described with reference to FIGS. 1 to 3, and an example of the slider according to the first embodiment will be described with reference to FIG. 4. Here, FIG. 1 is a perspective view of a slider body that forms the slider according to the first embodiment, and FIG. 2 is a view taken along the line II-II in FIG. FIG. 3 is a view in the direction of the arrow III in FIG. 1 and is a plan view of the slider body. FIG. 4 is a perspective view of the slider according to the first embodiment.

The slider main body 1 shown in the figure is a precursor of a slider disposed between an upper and lower eyelid having a sliding surface having a curvature, which forms a sliding seismic isolation device. The slider body 1 includes an upper surface 1a and a lower surface 1b having a curvature, and has a substantially cylindrical shape. The slider body 1 is formed from a rolled steel material for welding steel (SM490A, B, C, or SN490B, C, or S45C) or the like, and has a load bearing strength of about 60 N / mm ² (60 MPa). .

  On the upper surface 1a and the lower surface 1b of the slider body 1, a recess 2a and a recess 2b that are coaxial with the axis L of the slider body 1 are formed. The recesses 2a and 2b are counterbore holes that are circular in plan view and have the same area. As shown in FIG. 2, a solid part is interposed between the counterbore holes 2a and 2b.

  As shown in FIGS. 2 and 3, the slider body 1 has a diameter D1, and the upper and lower counterbore holes 2a and 2b have a diameter D2. Further, the height of the slider body 1 (the distance between the center points of the upper surface 1a and the lower surface 1b when there are no recesses 2a and 2b) is H.

  The recesses 2a and 2b are grooves provided to reduce the area of the upper surface 1a and the lower surface 1b as desired without reducing the outer diameter of the slider body 1. As shown in FIG. 3, when the area of the entire top surface 1a (projected area on the plane) is A1, and the area of the recess 2a (projected area on the plane) is A2, the effective area of the top surface 1a excluding the area of the recess 2a. A which is the (projected area on the plane) is A1-A2. These projected areas are set by the outer diameter D1 of the upper surface 1a and the lower surface 1b of the slider body 1 and the hole diameter D2 of the recesses 2a and 2b. Therefore, when A1 is preset according to the size of the building, the effective area A can be adjusted as desired by changing A2.

  Although the slider body 1 has counterbore holes 2a and 2b on both the upper surface 1a and the lower surface 1b, the slider body 1 has a solid portion between the upper and lower counterbore holes 2a and 2b. The reduction in the rigidity of the slider body 1 due to the counterbore holes 2a and 2b is suppressed as much as possible. In addition, regarding the depth of the counterbore holes 2a and 2b, since the range of the solid part of the slider main body 1 is increased and the rigidity of the slider main body 1 is increased by reducing the depth, the slider main body 1 is desired. The depths of the counterbore holes 2a and 2b are set so as to have the following rigidity.

  As shown in FIG. 4, the slider 10 is formed on the upper surface 1 a and the lower surface 1 b of the slider body 1 by attaching sliding materials 3 a and 3 b made of double fabric. The sliding materials 3a and 3b made of double woven fabric are double woven fabric layers made of PTFE fibers (polytetrafluoroethylene) and fibers having higher tensile strength than PTFE fibers. When the slider 10 is disposed between the upper collar and the lower collar, the PTFE fiber is disposed on the sliding surface side of the upper collar and the lower collar so that the upper surface 1a and the lower surface 1b of the slider body 1 are disposed. Each sliding material 3a, 3b is fixed.

  “Fibers with higher tensile strength than PTFE fibers” include polyamides such as nylon 6,6, nylon 6, nylon 4,6, etc., polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. Mention may be made of fibers such as polyester and para-aramid. In addition, fibers such as meta-aramid, polyethylene, polypropylene, glass, carbon, polyphenylene sulfide (PPS), LCP, polyimide, and PEEK can be given. Furthermore, fibers such as heat-sealing fibers, cotton, and wool may be applied. Among them, PPS fibers having excellent chemical resistance and hydrolysis resistance and extremely high tensile strength are desirable. Therefore, hereinafter, a description will be given by taking up a form in which the sliding materials 3a and 3b made of a double woven fabric are formed of PTFE fibers and PPS fibers.

  In the double woven fabric, weft yarns of PPS fibers are arranged on the slider body 1 side, and warps of PPS fibers are knitted so as to be wound. In addition, the wefts of PTFE fibers are arranged above them (positions on each heel side), and the warp of PTFE fibers are knitted so as to wind the wefts of PTFE fibers, and the warps of PTFE fibers are further lower PPS fibers. The wefts are also knitted so as to be involved. Then, the sliding materials 3 a and 3 b made of double woven fabric are fixed to the upper surface 1 a and the lower surface 1 b of the slider body 1 such that the PTFE fibers are disposed on the sliding surface side of the upper and lower ridges. Here, as a method of fixing the sliding materials 3a and 3b to the slider body 1, adhesion by an epoxy resin adhesive or the like can be applied. Since the PPS fiber has much better adhesion to the surface of the slider body 1 made of steel than the PTFE fiber, the sliding material 3a, 3b made of double woven fabric is applied to each PTFE fiber. The PPS fibers are preferably fixed to the slider body 1 with the PPS fibers arranged on the slider body 1 side.

  Further, since the PTFE fiber has a relatively low tensile strength, the sliding materials 3a and 3b made of a double woven fabric are liable to be crushed when subjected to repeated vibration (pressing sliding force) in a pressurized state. However, the crushed PTFE fiber has a higher tensile strength than that, and therefore stays in the highly crushed PPS fiber, so that at least a part of the crushed PTFE fiber can face the sliding surface of the upper heel and the lower heel. The good slidability of PTFE fiber can be enjoyed.

  As shown in FIG. 4, the sliding members 3a and 3b are bonded in a drum shape to the surfaces of the upper surface 1a and the lower surface 1b of the slider body 1 so as to cover the counterbore holes 2a and 2b. Therefore, it does not take time and effort to bond the sliding members 3a and 3b to the slider body 1. Although it takes time and effort, the sliding members 3a and 3b may be bonded to the surfaces of the upper surface 1a and the lower surface 1b of the slider body 1 so as to be along the wall surfaces of the counterbore holes 2a and 2b.

  Next, a modified example of the slider body will be described with reference to FIGS. 5A and 5B. 5A and 5B are both plan views of modified examples of the slider body. First, the slider main body 1A shown in FIG. 5A will be described. The illustrated slider main body 1A has a counterbore 2c having a square shape in plan view on the upper surface 1a. In addition, although illustration is abbreviate | omitted, it has the counterbore hole of the planar view square of the same shape and the same dimension as the counterbore 2c also in the lower surface 1b.

  On the other hand, the slider body 1B shown in FIG. 5B has a counterbored hole 2d having a regular hexagonal shape in plan view on the upper surface 1a. Although not shown, the lower surface 1b also has a countersunk hole having a regular hexagonal shape in plan view and having the same shape and the same size as the counterbore 2d. As described above, the counterbore hole is not limited to a circular shape in plan view, and various counterbore holes can be applied. However, the counterbore holes 2a and 2b having a circular shape in plan view are preferable in consideration of the ease of adjustment of the effective area and the fact that the recesses are provided uniformly in the direction of 360 degrees from the center of the upper surface 1a and the lower surface 1b.

[Slider according to the second embodiment]
Next, an example of a slider body that forms the slider according to the second embodiment will be described with reference to FIGS. 6 and 7, and an example of the slider according to the second embodiment will be described with reference to FIG. 8. . Here, FIG. 6 is a perspective view of the slider main body forming the slider according to the second embodiment, and FIG. 7 is a view taken along arrow VII-VII in FIG. is there. FIG. 8 is a perspective view of a slider according to the second embodiment.

  The illustrated slider main body 1C includes a through hole 2e extending over the upper surface 1a and the lower surface 1b in the axis L of the slider main body 1C. That is, it is a cylindrical slider body in which both concave portions of the upper surface 1a and the lower surface 1b communicate.

  As shown in FIG. 7, the diameter of the through hole 2e is D2, and the height of the through hole 2e is H which is the same as the height of the slider body 1C.

  The illustrated slider body 1C has a manufacturing advantage that it can be manufactured in a short time by performing, for example, punching or punching from the upper surface 1a to the lower surface 1b. Further, on the assumption that the slider body 1C has a predetermined rigidity, the weight of the slider body 1C is made as light as possible, which leads to the weight reduction of the sliding seismic isolation device including the slider body 1C.

  As shown in FIG. 8, sliders 10A are formed on the upper surface 1a and the lower surface 1b of the slider body 1C by attaching sliding materials 3a and 3b made of double fabric. Similar to the slider 10, the sliding members 3a and 3b are bonded in a drum shape to the surfaces of the upper surface 1a and the lower surface 1b of the slider body 1C so as to cover the through hole 2e.

[Slip Seismic Isolation Device According to Embodiment]
Next, an example of the sliding seismic isolation device according to the embodiment will be described with reference to FIGS. 9 and 10. Here, FIG. 9 is an exploded perspective view of the sliding seismic isolation device, and FIG. 10 is a longitudinal sectional view of the sliding seismic isolation device. In addition, the slider 10A is taken up and demonstrated as a slider which comprises the sliding seismic isolation apparatus shown in figure. As shown in the figure, the sliding seismic isolation device 100 includes an upper rod 20A, a lower rod 20B, and a slider 10A interposed between the upper rod 20A and the lower rod 20B.

  Both the upper rod 20A and the lower rod 20B are plate members having a square shape in a plan view, and are formed from a rolled steel material for welding steel (SM490A, B, C, or SN490B, C, or S45C), etc., like the slider body 1C. Yes. Both the upper rod 20A and the lower rod 20B have a sliding surface having a curvature on the side surface on the slider 10A side, and stainless sliding plates 20a and 20b are fixed to the sliding surface. Further, in the upper collar 20A and the lower collar 20B, a stopper ring 20c for preventing the slider 10A from falling off is fixed on the outer periphery of the sliding plates 20a and 20b.

  The sliding members 3a and 3b on the upper and lower surfaces of the slider 10A can realize a low coefficient of friction. The sliders 10A come into contact with the sliding plates 20a and 20b of the upper and lower rods 20A and 20B, so that the slider 10A Slide between. The sliding seismic isolation device 100 includes the slider 10A having the recess 2e, so that the outer diameter of the slider 10A is reduced even if the vertical load (axial force) acting on the sliding seismic isolation device 100 is small. The effective area of the upper and lower surfaces can be adjusted without any problem. As a result, it is possible to secure a predetermined surface pressure, suppress an increase in the friction coefficient, and obtain a desired seismic isolation effect. Further, since the outer diameter of the slider 10A is not reduced, bending stress generated in the slider 10A when the slider 10A is actuated can be suppressed as much as possible. Variations in the coefficient of friction of the device 100 can be suppressed. The suppression of the bending stress will be described in detail later.

[How to calculate the slider height]
Next, a method for calculating the height of the slider will be described with reference to FIG. FIG. 11 is a schematic diagram for calculating the height of the slider. In FIG. 11, the curvature radius of the upper collar 20A and the lower collar 20B is R, the curvature radius R in the vertical direction passing through the central axis of the upper collar 20A and the lower collar 20B, the curvature radius R passing through the center of curvature and the end, The angle between is θ. Further, in the sliding seismic isolation device 100, the height of the slider 10A is H, the depth due to the curvature of the sliding surface of the upper rod 20A and the lower rod 20B is h, and the clearance between the upper rod 20A and the lower rod 20B is 10 mm. To do.

  Based on the geometrical shape, the height H of the slider 10A is expressed by the following equation (4) based on the following equations (1), (2), and (3).

上式（４）により、スライダー１０Ａの高さＨを算定できる。

From the above equation (4), the height H of the slider 10A can be calculated.

[Experiments and results on surface pressure dependence of friction coefficient of sliding seismic isolation devices]
The inventors of the present invention operate a sliding seismic isolation device with an amplitude of ± 200 mm and a speed of 20 mm / second using a sliding seismic isolation device having a full-scale slider with an outer diameter of 350 mm on the upper surface and the lower surface, and act on the slider. An experiment was conducted to measure the surface pressure. Then, the reference surface pressure was set to 60 N / mm ^2, and the change rate of the friction coefficient at the measured surface pressure with respect to the friction coefficient at the reference surface pressure was obtained. FIG. 12 shows the rate of change of the friction coefficient for each surface pressure.

In FIG. 12, the equation for the rate of change of the friction coefficient is an approximate equation based on the measurement result. From FIG. 12, it can be seen that the friction coefficient increases as the surface pressure decreases, and that the increasing tendency of the friction coefficient becomes remarkable at a surface pressure of 30 N / mm ² or less. On the other hand, in the surface pressure range exceeding 60 N / mm ² , it can be seen that the friction coefficient converges to about 0.8 times the friction coefficient at the reference surface pressure.

[Calculation results regarding the area change rate of the slider and the change rate of the section modulus of the slider when the hole diameter of the recess is changed]
The inventors calculated the area change rate of the slider and the cross-section coefficient change rate of the slider when the hole diameter of the recess was changed, and verified the comparison of the change rates of both. In the following, equations (5) and (6) are respectively expressed by assuming that the area (projection area on the plane) of a conventional slider (circular in plan view and substantially cylindrical) without a recess is A ₀ and the section modulus is Z _0. Show. The area of the slider having recesses (holes) shown in FIG. 7 (projected area of the plane) A _1, the section modulus as Z _1, equation (7), respectively (8). The slider diameter and the through hole diameter are D1 and D2, respectively.

式（７）を式（５）で除してスライダーの面積変化率とし、式（８）を式（６）で除してスライダーの断面係数変化率とする。スライダーの面積変化率を以下の式（９）に示し、スライダーの断面係数変化率を以下の式（１０）に示す。

The expression (7) is divided by the expression (5) to obtain the area change rate of the slider, and the expression (8) is divided by the expression (6) to obtain the slider section coefficient change rate. The area change rate of the slider is shown in the following formula (9), and the cross section coefficient change rate of the slider is shown in the following formula (10).

式（９）より、スライダーの面積変化率は、Ｄ２／Ｄ１の二乗で低下することが分かり、式（１０）より、スライダーの断面係数変化率は、Ｄ２／Ｄ１の四乗で低下することが分かる。式（９）、（１０）を図１３に示す。

From the equation (9), it can be seen that the area change rate of the slider decreases with the square of D2 / D1, and from the equation (10), the change rate of the section modulus of the slider decreases with the square of D2 / D1. I understand. Equations (9) and (10) are shown in FIG.

From FIG. 13, as the hole diameter of the concave portion increases and D2 / D1 increases, both the area change rate and the section modulus change rate of the slider decrease in a curved manner, but compared to the area change rate (decrease rate), It can be seen that the change rate (decrease rate) of the section modulus is small. Accordingly, in reducing the area of the slider by providing recesses on the upper and lower surfaces of the slider, the rate of decrease in the section modulus is smaller as the area is decreased. Here, the end stress of the slider is described below. It is assumed that an axial force P acts on the slider and a bending moment M (= μPH / 2) acts on the slider. When the average stress due to the axial force P is σ _O and the increased stress due to the bending moment is σ _B (M / Z), the end stress σ _V = σ _O + σ _B. In a slider having concave portions on the upper surface and the lower surface, σ _O and σ _V are expressed by the following equations (11) and (12) using the above equations (7) and (8).

凹部の面積を調整することにより、スライダーの外径を小さくすることなく、スライダーの面積を調整することができ、スライダーの面積の低下割合に比べてスライダーの断面係数の低下割合が低いことから、スライダーが作動した際にスライダーの特に上面及び下面の端部に生じる曲げ応力（端部応力）を可及的に抑制することができる。

By adjusting the area of the recess, it is possible to adjust the area of the slider without reducing the outer diameter of the slider, and since the rate of decrease in the section modulus of the slider is lower than the rate of decrease in the area of the slider, Bending stress (edge stress) generated at the end portions of the upper surface and the lower surface of the slider when the slider is operated can be suppressed as much as possible.

[Design example]
One design example by the present inventors is shown using FIG. 14 and FIG. In this design example, when the slider diameter is D1 and the height is H, in a sliding seismic isolation device having a cylindrical slider with D1 / H = 0.5, the surface pressure of the slider is increased five times, and Assume that the stress increase due to the bending moment is 10% or less of the stress due to the axial force. Here, with respect to the average stress that only the normal axial force acts on, the bending stress when the bending moment acts, particularly the end stress at the end of the slider is suppressed to 10% or less of the average stress, This is important from the viewpoint of suppressing early wear of the sliding material mounted on the slider surface and further suppressing variation in the friction coefficient of the sliding seismic isolation device.

  Here, in both FIGS. 14 and 15, the horizontal axis represents the rate of change in the outer diameter of the slider. The outer diameter change rate is a ratio when the outer diameter of the slider is changed with respect to the reference outer diameter, where D1 (reference) is the initial outer diameter of the slider. On the other hand, the vertical axis represents the area change rate of the slider. As described above, this is the ratio of the projected area onto the plane due to the outer diameter of the slider and the effective area obtained by removing the area of the recess from the projected area. In the graph, graphs of 8 cases of D2 / D1 = 0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.85, and 0.89 are shown.

  In other words, increasing the surface pressure five times means that the area of the slider is changed from the initial 1.0 to 0.2. Therefore, in FIG. 14, a threshold line parallel to the horizontal axis where the area change rate of the slider is 0.2 is drawn, and the outer diameter change rate of the slider at the point where this threshold line and each graph intersect is specified.

  In FIG. 14, four representative cases are extracted. Case 0 shows a graph of D2 / D1 = 0, which corresponds to a conventional slider without a recess, which is based on the vertical and horizontal axes before the surface pressure is increased by a factor of 5. It is set to 1.0.

  Case 1 shows a case where the surface pressure of a conventional slider with D2 / D1 = 0 is increased five times, and the outer diameter change rate of the slider is 0.45, that is, the initial reference of the slider. It shows that the outer diameter of the slider needs to be reduced to less than half of the outer diameter.

  On the other hand, Case 2 shows a graph of D2 / D1 = 0.8, which corresponds to the slider of the present invention in which the diameter of the recess is 0.8 times the outer diameter of the slider. In this case, a surface pressure of 5 times can be achieved simply by setting the outer diameter of the slider to 0.75 times the reference outer diameter. That is, the ratio of reducing the outer diameter of the slider can be significantly reduced as compared with the conventional slider.

  Case 3 shows a graph of D2 / D1 = 0.89, which corresponds to the slider of the present invention in which the diameter of the recess is 0.89 times the outer diameter of the slider. In this case, it is possible to achieve a surface pressure of 5 times while maintaining the outer diameter of the slider as a reference outer diameter, that is, without reducing the outer diameter of the slider.

In FIG. 15, the vertical axis represents the coefficient of increase in force due to the bending moment. This stress increase coefficient is the ratio of σ _V and σ _{O described} above. Each case 0, 1, 2, 3 of FIG. 14 is plotted in the graph. First, in case 0, when the change rate of the outer diameter of the slider is 1.0 (no change), σ _V / σ _O is 1.1 (σ _V is 10% increase of σ _O ). , 3 specified σ _V / σ _O when the values on the horizontal axis are the same as those in FIG.

From FIG. 15, Case 1 shows that σ _V / σ _O at an outer diameter change rate of 0.45 is about 1.22, and σ _V increases by 20% or more of σ _O.

On the other hand, in case 2, σ _V / σ _O when the outer diameter change rate is 0.75 is 1.08, indicating that σ _V can be suppressed to 10% increase or less of σ _O.

In case 3, σ _V / σ _{O in the} absence of the outer diameter change rate is 1.06, indicating that σ _V can be suppressed to 10% or less increase of σ _O.

  From the design examples of FIGS. 14 and 15, by providing a recess having a hole diameter of about 0.8 times the outer diameter of the slider on the upper and lower surfaces of the slider, the outer diameter of the slider is not reduced as much as possible. It can be seen that high surface pressure can be secured and the increase in stress caused by the bending moment can be reduced as much as possible. In addition, by making the hole diameter of the recess about 0.89 times the outer diameter of the slider, high surface pressure can be secured without reducing the outer diameter of the slider, and the increase in stress caused by the bending moment can be further reduced. I understand.

[About the optimal ratio of the concave hole diameter to the slider outer diameter]
The inventors of the present invention have verified the optimal ratio range between the hole diameter of the recess and the outer diameter of the slider. Here, the outer diameter of the slider is D1, the hole diameter of the recess (through hole) is D2, the height of the slider is H, the average stress due to the axial force in the slider is σ _O , the upper surface of the slider when the bending moment is applied, _Let σ _V be the stress at the end of the lower surface. As described in the above design example, suppressing σ _V / σ _O to 1.1 or less, that is, suppressing an increase stress due to a bending moment to 10% or less is an effect of the sliding material mounted on the slider surface. Considering that it is important from the viewpoint of suppressing early wear and further suppressing variation in the coefficient of friction of the sliding seismic isolation device, σ _V / σ _O = 1.1 was set as a threshold value. Here, in FIG. 16, D2 / D1 is taken on the horizontal axis, and σ _V / σ _O is taken on the vertical axis. Each graph when D1 / H was changed from 1.0 to 10 was described, and the value of D2 / D1 at which each graph intersected the threshold line of σ _V / σ _O = 1.1 was read. Based on the read values, a graph shown in FIG. 17 was created. In this example, D1 / H is taken on the horizontal axis, D2 / D1 is taken on the vertical axis, the values read in FIG. 16 are plotted, and an approximate curve connecting the plots is created. In FIG. 17, the approximate curve is represented by the following equation (13).

図１７に示すように、式（１３）よりもＤ２／Ｄ１が大きくなる領域では、σ_Ｖ／σ_Ｏが１．１以下となり、応力増加を十分に抑制することができる。

As shown in FIG. 17, in the region where D2 / D1 is larger than Expression (13), σ _V / σ _O is 1.1 or less, and the increase in stress can be sufficiently suppressed.

  In a normal slider design, the slider height is first set according to the building size and the like. Therefore, when the outer diameter D1 of the slider is arbitrarily set, by setting the hole diameter of the recess so as to be in the upper range of the graph using FIG. It becomes possible to design a sliding seismic isolation device having a slider that can suppress variations.

  It should be noted that other embodiments in which other components are combined with the configurations described in the above embodiments may be used, and the present invention is not limited to the configurations shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

1, 1A: Slider body 1B, 1C: Slider body 1a: Upper surface 1b: Lower surface 2a, 2b: Concave portion (counterbore hole)
2c, 2d: Concave portion (counterbore hole)
2e: recessed portion (through hole)
3a, 3b: Sliding material (double woven fabric)
10, 10A: Slider 20A: Upper rod 20B: Lower rod 20a, 20b: Sliding plate 20c: Stopper ring 100: Sliding seismic isolation device

Claims (7)

A slider for a steel sliding seismic isolation device, which is disposed between an upper and lower armature having a sliding surface having a curvature, and has an upper surface and a lower surface having a curvature,
The top surface and the bottom surface each have a concave portion at the center in plan view, and the concave portion forms a sliding seismic isolation device in a hollow state . Slider.   2. The sliding seismic isolation device according to claim 1, wherein the upper surface and the lower surface have a circular shape in plan view, both have the same area, and both have the same area of the recess. Slider.   The slider for a sliding seismic isolation device according to claim 1 or 2, wherein the recess is a counterbore.   The slider for a sliding seismic isolation device according to claim 1 or 2, wherein the recess is a through hole extending from the upper surface to the lower surface. 5. The planar view shape of the upper surface and the lower surface and the planar view shape of the recess are both circular and satisfy the following formula (A). 5. Slider for sliding seismic isolation device.

On the upper surface and the lower surface of the slider, a sliding material made of a double woven fabric composed of PTFE fibers and fibers having a higher tensile strength than the PTFE fibers is fixed,
6. The sliding seismic isolation according to claim 1, wherein the PTFE fiber is disposed on the sliding surface side of the upper and lower ridges in the sliding material. Slider for equipment. An upper arm and a lower arm with a sliding surface having a curvature;
A sliding seismic isolation device comprising: a slider according to any one of claims 1 to 6, comprising an upper surface and a lower surface having a curvature.

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