JP2007239892A - Base isolation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stable base isolation device for providing substantially constant base isolation performance regardless of the relative positional relationship between the support object side and the support side, by improving fluctuation in contact pressure with the guide rail side and fluctuation in a rotational ratio on the basis of a position of a sphere, in a base isolation layer using a guide rail and the sphere. <P>SOLUTION: This base isolation device has the guide rail 1 having mutually separately arranged opposed inclined faces 5 and 6 each composed of a specific inclination and constituted so that an interval between the mutual these inclined faces 5 and 6 becomes gradually small toward both outside ends from a central part, and the sphere 2 rolling by abutting from the inside on the respective inclined faces 5 and 6 of this guide rail. The return function is imparted by displacement in the height direction of the sphere 2 itself generated when its sphere 2 rolls to the outside end side from the central part while abutting on the inclined faces 5 and 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a seismic isolation device installed between a supported body side and a support body side. More specifically, the present invention relates to a seismic isolation device having an origin return function for returning the relative positional relationship between the supported body side and the support body side to the original positional relationship.

2. Description of the Related Art Conventionally, seismic isolation devices that employ a rolling support system that uses rolling elements such as a sphere, rollers, and wheels have been widely known. These seismic isolation devices that use a rolling bearing system are excellent in insulation between the support side and the support side, but maintain an accurate trajectory and ensure a smooth origin return mechanism. There was a basic problem that the structure became complicated and eventually increased the cost. Therefore, in order to solve these problems, a flat guide rail is used, and the rolling elements are supported and guided by guide support edges on both sides formed apart from the guide rail. There has been proposed a seismic isolation device that realizes a linear trajectory and an origin return function by forming so that the distance between the support edges gradually decreases from the center toward both outer ends (Patent) Reference 1).
JP 2005-48837 A

  By the way, the above-mentioned prior art has an accurate track with a simple configuration in which the distance between the guide support edges on both sides formed in the guide rail is gradually reduced from the center toward both outer ends. It is excellent in that it can secure a smooth origin return mechanism, but the contact position with the guide support edge is displaced in the rolling axis direction depending on the position of the rolling element, so for example when the rolling element is a sphere As shown in FIGS. 13A and 13B, the contact angle at the contact portion between the sphere and the guide rail varies from θa to θb at the center and both outer ends of the guide rail. As a result, there was a technical problem that the contact pressure also fluctuated. Further, the rotation radius of the rolling element also varies depending on the position of the rolling element, and the rotation radius is smaller at the center of the guide rail than at both outer ends, and the rotation rate is increased while moving the same distance. There was also a problem. And the fluctuation of the contact pressure and the rotation rate based on the position of those rolling elements changes the seismic isolation performance depending on the relative positional relationship between the supported body side and the support body side, that is, the relative movement amount by the seismic isolation device. It was also a factor.

  In view of the above-described conventional technical situation, the present invention improves fluctuations in contact pressure and rotation rate with the guide rail based on the position of a sphere that occurs when a sphere is adopted as a rolling element. An object of the present invention is to provide a seismic isolation device that can obtain a substantially constant seismic isolation performance regardless of the relative positional relationship between the support side and the support side, and is more stable in terms of operation and strength.

  In the present invention, in order to solve the above-mentioned problem, the inclined surfaces having a certain inclination angle that are spaced apart from each other are provided, and the interval between these inclined surfaces is directed from the central portion toward both outer end portions. The technical means is provided that includes a guide rail configured to gradually become smaller and a sphere that rolls in contact with each inclined surface of the guide rail from the inside. A return function is provided by the displacement of the sphere itself in the height direction that occurs when the sphere rolls from the central portion to the outer end side while abutting the inclined surface.

According to the present invention, the following effects can be obtained.
(1) Since the inclination angles of the inclined surfaces on both sides are configured to be constant, the contact angle and the contact pressure between the sphere and the inclined surface on the track are maintained substantially constant. Thereby, almost constant seismic isolation performance is obtained regardless of the position of the sphere, and a smoother and more stable rolling operation of the sphere is possible. In addition, since the contact pressure is maintained almost constant regardless of the position of the sphere, strength management is easy, including the design and manufacture of guide rails and spheres, and the desired seismic isolation performance can be achieved more simply and accurately. Can be realized and maintained.
(2) Since the inclination angles of the inclined surfaces on both sides are made constant, the contact angle between the sphere and the inclined surface on the track and the rotational radius around the rolling axis of the sphere are kept substantially constant. As a result, fluctuations in the rotation rate associated with the prior art are improved. From this point as well, a stable and smooth rolling operation can be obtained regardless of the position of the sphere, and a more stable seismic isolation operation can be obtained. Can do.

  The seismic isolation device according to the present invention is installed between the lower structure side such as the ground which is the support side and the upper structure side such as the case which is the supported body side as a seismic isolation device for various buildings. It can be widely applied. Depending on the case, it can be installed in the middle of the housing. In addition, for example, when installed under the floor of a room in an existing or new building such as a computer room to protect hardware equipment in the room, or installed in an existing or new building The present invention can be widely applied to the case where it is installed between a superstructure for supporting an exhibit to be displayed and a floor portion to protect the exhibit such as a work of art. A spherical body is adopted as the rolling element, but the size can be appropriately selected depending on the case. In addition, the inclined surfaces as the supporting guide surfaces of the spheres that are placed opposite to each other on the guide rail are formed at a constant inclination angle, and while maintaining the constant inclination angle, the inclination surfaces can be connected to each other. It suffices if the interval is configured so that the distance from the center gradually decreases toward the both outer ends. Regarding the specific shape of the inclined surface along the rolling direction adopted to change the interval between the inclined surfaces, the one that changes the interval by changing linearly is the sphere on the orbit. Although it is desirable that the contact angle with the inclined surface is always kept constant, it is not particularly limited to this, and the contact angle may be changed by a gentle curve. Regarding the specific angle of the inclined surface of the guide rail, the mass of the superstructure, the height difference on the orbit of the sphere, that is, the strength of the origin return function, the ratio between the diameter of the sphere and the interval between the inclined surfaces, etc. It can be selected as appropriate. Moreover, there is no restriction | limiting regarding the up-and-down relationship between a guide rail and a spherical body, and it can be applied regardless of which is above or below.

  FIG. 1 is a schematic perspective view showing a main part of a seismic isolation device according to the present invention. In the figure, 1 is a guide rail, and 2 is a sphere as a rolling element supported and guided by the guide rail 1. In the guide rail 1 of the present embodiment, the case where the rail portion 3 is composed of two divided rail portions 3 and 4 is shown. However, the rail portion 3 and 4 are continuously connected to each other on the bottom surface side. It may be a thing. In the rail portions 3 and 4 constituting the guide rail 1, inclined surfaces 5 and 6 as guide support surfaces of the sphere 2 are arranged along the rolling direction of the sphere 2 while maintaining a constant inclination angle θ. It is formed so that the interval between the inclined surfaces 5 and 6 linearly changes so as to gradually decrease from the central portion toward both outer end portions. Here, the inclination angle θ is an angle formed by the inclined surfaces 5 and 6 in a cross section perpendicular to the axial direction of the guide rail 1 on which the sphere 2 rolls.

2 and 3 are explanatory views for explaining the basic operation principle of the seismic isolation device according to the present invention. FIG. 2 is formed on the sphere 2 and the rail portions 3 and 4 near the center of the guide rail 1. FIG. 3 shows a contact state between the spherical body 2 at both outer ends of the guide rail 1 and the inclined surfaces 5 and 6 formed on the rail portions 3 and 4. It shows the contact state. Here, as shown in FIG. 2, when viewed in a cross section perpendicular to the rolling direction of the sphere 2 in the contact state with the sphere 2 near the center of the guide rail 1, as shown in FIGS. 4 and 5. The apparent center C ′ (cross section) deviated from the center C of the sphere 2 by an angle φ in the rail installation direction (angle φ formed by the rolling direction of the sphere 2 and the direction along the rolling surface of the guide rail 1). It is represented by a cross section including the contact point between the upper center C ′) and the inclined surfaces 5 and 6. The angle formed between the perpendicular line extending from the center C ′ on the cross section in the direction of gravity (vertical) and the line connecting the contact point of the inclined surfaces 5 and 6 from the center C ′ is the inclination angle of the rail portions 3 and 4. It becomes the same as θ. From the above, the contact pressure Pa generated on the inclined surfaces 5 and 6 by the load W from the upper structure works from the center C of the sphere 2 toward the contact portion of the sphere 2 and is calculated by the following equation. be able to.

Furthermore, the interval La between the contact portion between the sphere 2 and the inclined surface 5 and the contact portion between the sphere 2 and the inclined surface 6 can be calculated from the above contents by the following equation (r is the sphere 2 radius).

Similarly, as shown in FIG. 3, the rail installation direction from the center C of the sphere 2 when viewed in a cross section perpendicular to the rolling direction of the sphere 2 in the contact state at both outer ends of the guide rail 1. The apparent center C ″ (center C ″ on the cross section) and the inclined surface 5, which are shifted by an angle φ (the angle φ formed by the rolling direction of the sphere 2 and the direction along the rolling surface of the guide rail 1). It is represented by a cross section including 6 contact points. The angle formed by the perpendicular line extending from the center C ″ on the cross section in the gravity (vertical) direction and the line connecting the contact point of the inclined surfaces 5 and 6 with the center C ″ is the inclination angle of the rail portions 3 and 4. Since it is the same as θ, the contact pressure Pb generated at the contact portion of the inclined surfaces 5 and 6 from the center C of the sphere 2 by the load W from the upper structure, and the contact between the sphere 2 and the inclined surface 5 The distance Lb between the contact portions of the sphere 2 and the inclined portion 6 can be calculated by the following equation (r is the radius of the sphere 2).

  Thus, the contact state between the sphere 2 near the center of the guide rail 1 shown in FIG. 2 and the inclined surfaces 5 and 6 formed on the rail portions 3 and 4, and the guide rail 1 shown in FIG. Comparing the contact state between the spherical body 2 and the inclined surfaces 5 and 6 formed on the rail portions 3 and 4 at both outer ends, the contact angle θ and the angle φ in the installation direction of the rail portions 3 and 4 are constant. Therefore, it is clear that the contact pressures Pa and Pb and the distances La and Lb between the contact portions do not change. That is, the inclined surfaces 5 and 6 of the guide rail 1 in the seismic isolation device according to the present invention are formed at a constant contact angle θ appropriately set over the entire length of the guide rail 1. The contact pressure P and the distance L between the contact portions at the contact portions between the inclined surfaces 5 and 6 and the sphere 2 are always constant and do not change. Further, since the distances La and Lb between the contact portions are always constant, the rotation radius around the rolling axis of the sphere 2 is always constant and does not change. Therefore, regardless of the position of the sphere 2, the sphere The rotation rate of 2 is always constant. In the contact state between the inclined surfaces 5 and 6 and the sphere 2 at the center of the guide rail 1, the contact portion becomes four points, and therefore the contact pressure P based on the load W from the upper structure is instantaneous. However, in terms of the overall movement of the sphere 2, it is only a very short time, and there is no problem with the seismic isolation performance. Incidentally, the height of the center C ′ of the sphere 2 in FIG. 2 showing the contact state between the sphere 2 and the inclined surfaces 5 and 6 in the vicinity of the center of the guide rail 1 and the sphere 2 at both outer ends of the guide rail 1. 3 and the height of the center C ″ of the sphere 2 in FIG. 3 showing the contact state between the inclined surfaces 5 and 6, the height of the sphere 2 itself generated when rolling from the center to both outer ends. This corresponds to the displacement in the vertical direction, and this gives a return function.

  In the following, an embodiment embodied by applying the basic configuration of the present invention will be described. 6 to 8 show a first embodiment of the present invention. FIG. 6 is a front view thereof, FIG. 7 is a plan view, and FIG. As shown in the figure, the seismic isolation device 13 according to the present embodiment has lower guide rails 15 to 18 having a basic configuration similar to that of the guide rail 1 disposed below with a flat intermediate member 14 interposed therebetween. The upper guide rails 19 to 22 having the same configuration and the upside down are arranged in the upper direction in the direction perpendicular to the lower guide rails 15 to 18. And by interposing between the intermediate member 14 in the state which engaged each one spherical body 23 between the inclined surfaces of those guide rails 15-22, the upper structure 24, the lower structure 25, and The seismic isolation operation can be obtained with respect to relative movement in any direction. That is, with respect to the relative movement in the horizontal direction between the upper structure 24 and the lower structure 25, the combination of the lower guide rails 15 to 18, the sphere 23, and the intermediate member 14 can be used. Relative movement corresponds to the combination of the upper guide rails 19 to 22, the sphere 23 and the intermediate member 14, and any combination of the guide rails 15 to 22, the sphere 23 and the intermediate member 14 can be used. It is configured so that seismic isolation operation can be obtained even with relative movement in direction.

  9 and 10 show a second embodiment of the present invention. FIG. 9 is a front view thereof, and FIG. 10 is a plan view thereof. As shown in the figure, a seismic isolation device 26 according to the present embodiment has a lower guide rail 28 having a basic configuration similar to that of the guide rail 1 and the guide rail 7 below with a flat intermediate member 27 interposed therebetween. The seismic isolation units 31 to 34 each having a configuration similar to that of the upper guide rail 29 and the spherical body 30 engaged between the inclined surfaces are arranged. In addition, the upper structure 24 and the lower part are disposed in the same manner as in the first embodiment by disposing the base isolation units 35 to 38 having the same configuration above in the direction orthogonal to the base isolation units 31 to 34. A seismic isolation operation is obtained with respect to relative movement in any direction with the structure 25.

  11 and 12 show a third embodiment of the present invention. FIG. 11 is a front view thereof, and FIG. 12 is a plan view thereof. This embodiment is a modification of the second embodiment. As illustrated, in the seismic isolation device 39 according to the present embodiment, an intermediate member 40 made of a cross-shaped flat plate is adopted as an intermediate member, and the lower part similar to the above-described base isolation unit is sandwiched between the intermediate members 40. The seismic isolation units 41 and 42, which are a combination of the guide rail 28, the upper guide rail 29, and the sphere 30 engaged between the inclined surfaces, and the seismic isolation units 43 and 44 are formed in the shape of the intermediate member 40. By arranging them together in a cross shape, a seismic isolation operation can be obtained for relative movement in any direction between the upper structure 24 and the lower structure 25.

It is the schematic perspective view which showed the principal part of the seismic isolation apparatus which concerns on this invention. It is explanatory drawing for demonstrating the fundamental operating principle of the seismic isolation apparatus which concerns on this invention. It is explanatory drawing for demonstrating the fundamental operation | movement principle of the seismic isolation apparatus. It is a schematic perspective view for demonstrating the contact state of the guide rail and spherical body of the seismic isolation apparatus which concerns on this invention. It is explanatory drawing for demonstrating the contact state of the guide rail and spherical body of the seismic isolation apparatus. It is the front view which showed 1st Example of this invention. It is the top view which showed the same Example. It is AA sectional drawing of FIG. It is the front view which showed 2nd Example of this invention. It is the top view which showed the same Example. It is the front view which showed 3rd Example of this invention. It is the top view which showed the same Example. It is explanatory drawing which showed the contact state of the spherical body and guide rail in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Guide rail, 2 ... Sphere, 3, 4 ... Rail part, 5, 6 ... Inclined surface, 13 ... Seismic isolation device, 14 ... Intermediate member, 15-18 ... Lower guide rail, 19-22 ... Upper guide rail, 23 ... Sphere, 24 ... Upper structure, 25 ... Lower structure, 26 ... Seismic isolation device, 27 ... Intermediate member, 28 ... Lower guide rail, 29 ... Upper guide rail, 30 ... Sphere, 31-38 ... Seismic isolation unit 39 ... Seismic isolation device, 40 ... Intermediate member, 41-44 ... Seismic isolation unit

Claims (1)

A guide rail configured to have opposed inclined surfaces having a certain inclination angle arranged apart from each other, and the interval between the inclined surfaces is gradually reduced from the central portion toward both outer end portions; A seismic isolation device comprising: a spherical body that rolls in contact with each inclined surface of the guide rail from the inside.

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