JPH1037519A - Seismic isolation rolling bearing for structures - Google Patents

Abstract

(57) [Summary] [Problem] To provide a seismic isolation device that has a structure that does not resonate with any earthquake (has no resonance point), does not oscillate under normal vibrations, and is easy to design. To do. SOLUTION: A saucer 4 having a conical recess, a bearing body 20 facing the saucer, and the bearing body 20 has a spherical recess having a surface of a low friction material 10 on an opposing surface of the saucer, A seismic isolation rolling bearing having a large-diameter sphere 9 that slides into the spherical depression, and a support body 20 having a structure for supporting a saucer via the large-diameter sphere 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a seismic isolation device for a structure,
In particular, it is an object of the present invention to provide a seismic isolation device having a seismic isolation function and a seismic isolation function using a bearing body using a low friction material and a large diameter sphere and a saucer having a conical concave surface.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a seismic isolation device in which a concave surface of a receiving tray is brought into contact with a support body. In this prior art, the concave surface of the pan body is made spherical because the surface pressure of the contact surface is always constant even if the contact surface (concave surface) between the bearing body and the pan is relatively displaced by horizontal movement. . For example, as shown in FIG. 5, a saucer 18 having a spherical concave surface 17
As a low friction material (fluorine resin) 19 is pressed against the top,
The support 2 joined to the medium 20 is combined, and this support 2
1 is a structure on which a structure is placed.

The low-friction material 19 has a spherical surface so as to be rotatable at the joint surface of the medium 20, and a large earthquake causes a vibration of an acceleration equal to or more than the product of the friction coefficient of the low-friction material and the gravitational acceleration to act thereon. When the support 18 and the support 21 slide relative to each other, the low friction material 19 rotates in the medium 20 of the support 21 and can slide with the same surface pressed against the concave surface of the tray 18. At this time, when the position is off the center of the tray, it is always at a position higher than the center, so that the force returning to a lower position due to gravity acts as a restoring force and returns to the original center.

[0004] This is because when a horizontal movement occurs due to an earthquake,
Because it is a structure that obtains restoring force by the principle of the pendulum,
In the case of a seismic wave (for example, Hachinohe seismic wave) having a fixed period and a long period component, resonance may occur and the expected seismic isolation effect may not be obtained. To avoid this resonance,
It is conceivable to extend the natural period by increasing the curvature of the saucer, but there was a problem that the restoring force was reduced and it was difficult to restore to the original position after the earthquake stopped.

FIG. 4 shows a laminated rubber seismic isolation device containing a lead plug, which is one of the prior arts. This device has a laminated inner steel plate 23 surrounding a lead plug 26 and a rubber layer 22. The upper and lower portions are sandwiched between outer steel plates 24, and a mounting plate 27 having dowel pins 25 on the upper and lower surfaces thereof is provided.

This device has too high a horizontal rigidity, that is,
Since the natural period is short, resonance may occur depending on the vibration period of the earthquake, and the vibration may be amplified instead. In addition, since the rocking motion due to the wind cannot be suppressed, there is a problem that the livability is impaired.

[0007]

SUMMARY OF THE INVENTION The present invention has a structure that does not resonate with any earthquake (having no resonance point), does not oscillate under normal vibration due to friction, and does not swing after the earthquake stops. It is an object of the present invention to provide a seismic isolation device for a structure having a restoring force that returns to its original position and an easily designed seismic isolation device.

[0008]

An embodiment of the present invention for solving the above-mentioned problems is a seismic isolation rolling bearing as described in the claims.

That is, the present invention provides (1) a saucer having a conical recess, and a bearing body facing the saucer, and the bearing body has a spherical recess having a surface made of a low-friction material on a face facing the saucer. A large-diameter sphere that slides into the spherical recess, and the bearing body is a seismic isolation rolling support for a structure that is configured to support the pan via the large-diameter sphere. The conical inclination angle is 1 to 4 °, and the low-friction material is tetrafluoroethylene resin. The seismic isolation rolling bearing of the structure according to the above (1), (3) the conical inclination of the tray. The range of the trigger is constituted by selecting the diameter of the corner and the diameter of the large diameter sphere and the kind and shape of the low friction material, and the maximum response acceleration is arbitrarily set. It is a base-isolated rolling bearing for structures.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a seismic isolation rolling bearing according to the present invention, and FIG. 2 is a sectional view thereof.

This rolling bearing has a grout material 13 under a top plate 1 having a rubber layer 2 on the surface, a saucer plate 4 formed in a conical shape, and a saucer having a reinforcing material 8 at the center.
It is supported by a support having a base plate 6 and a ball bearer 7 via a ball (large diameter sphere) 9.

As shown in FIG. 3, the bearing body comprises a large-diameter ball 9 and a ball-bearing retainer 7 having a concave portion for supporting the large-diameter ball.
The concave portion of the ball bearer 7 has a sliding cup 28 composed of a phenol resin layer 10 and a tetrafluoroethylene layer 11 so that the large-diameter sphere 9 can rotate easily.
5 prevents the large-diameter sphere 9 from falling out.

In the apparatus of the present invention, the trigger for the wind can be arbitrarily set within a certain range (usually about 60 to 100 gal). Also, the seismic isolation performance is not affected by the uneven distribution of the loading of the structure. Further, since the concave portion of the tray has a conical shape with a constant inclination, there is no natural oscillation period. Therefore, it does not resonate with the earthquake.

The range of the trigger can be set as follows according to the inclination angle of the tray, the diameter of the large-diameter sphere, and the type and shape of the friction material. By selecting the material of the sliding cup in the concave portion of the ball bearer 7 in contact with the large-diameter sphere 9, the coefficient of friction with the large-diameter sphere can be set to an appropriate value. The maximum response acceleration is determined by the coefficient of friction and the inclination angle of the pan. When a material in which tetrafluoroethylene is adhered and fixed to the inner surface of the phenol resin is used as the sliding cup of the concave portion in contact with the large-diameter sphere 9 of the apparatus shown in FIG.
０．１0.10.

FIG. 6 shows a comparative example of the support body, in which the phenol resin layer 10 and the ethylene tetrafluoride layer 1 in the concave portions shown in FIG.
This is an example in which a small-diameter sphere 16 is provided instead of 1.

In the case of this support, a ball bearer 7
Is 0.03, which is the coefficient of friction μ between the concave portion and the large-diameter sphere 16. Therefore, the trigger performance is too small.

FIG. 7A is a plan view showing a state where the steel ball cover 15 and the large-diameter ball 9 are removed from the bearing shown in FIG. 3, and FIG. 8 is an exploded view of the bearing. A slide cup 28 is provided in the recess of the holder 12, and the holder 12 supports the large-diameter sphere 9 via the slide cup 28. Large-diameter ball 9 is steel ball cover 1
5 prevents the holder 12 from falling off. The holder 12 is inserted into the base plate 6 having the ball bearer 7 as shown.

The sliding cup 28 is formed by adhesively fixing a sliding member 11 made of tetrafluoroethylene to an inner surface of a cup 10 made of a phenol resin. As shown in a plan view of FIG. The tongue-shaped sliding material 11 is adhered so as to form the passage 29.

In order to obtain the desired value of the friction between the large-diameter sphere 9 and the sliding cup 28, it is preferable to select and adopt a sliding material 11 having a different shape, number and area.

Another example of the sliding cup 28 is shown in a plan view of FIG. 9 and a perspective view of FIG. This may be a small disk-shaped small piece made of tetrafluoroethylene adhered to the inner surface of the cup 10 made of phenol resin.

In the apparatus of the present invention, the trigger level is determined by the sliding low drag when the large-diameter sphere slides and rotates on the surface of the low friction material (for example, the tetrafluoroethylene layer) and the horizontal movement resistance of the inclination angle of the pan. And the maximum response acceleration is roughly determined.

In this case, as a factor of the sliding resistance between the large-diameter sphere and the low-friction material, a viscous damping force in the low-friction material can be expected to some extent in addition to a proper friction damping during operation. These are the effects of suppressing the seismic response displacement. Types of low frictional force include Teflon, phenolic resin, high-molecular polyethylene resin, polyamide resin, nylon resin, ceramics and the like.

[0023]

EXAMPLES Tables 1 and 2 below show the response to typical seismic waves in the past when the viscous damping in the low friction material was set to zero, and calculation examples for the case where the tilt angle of the saucer and the friction coefficient were changed. Show.

The inclination of the resin-based sliding material and the tray used in Examples 1 to 3 and the strength of the resistance were as follows.

Table 1 shows a coefficient of friction generated between the sliding member and the ball, and a proper inclination angle of the pan in consideration of automatic return to the origin after the end of the earthquake.

[0026] These two factors determine the starting acceleration (trigger) and the seismic isolation effect, ie the maximum response acceleration.

Example 1 is an example in which ethylene tetrafluoride is used as the sliding material, Example 2 is comparable to high-molecular polyethylene and nylon resin, and Example 3 is comparable to phenol resin.

As the seismic isolation effect, the ball bearing type is the best, but when applied as a seismic isolation device for a house,
Fluctuations are caused by the constant wind, which makes habitability a problem. In order to overcome this problem, the conditions (triggers) of Examples 1 to 3 are appropriate. In an area where a windy place is always determined, it is necessary to select and apply any of these trigger levels. it can.

Table 2 shows the response displacement at the time of seismic wave input to any of the selected Examples 1 to 3.

[0030]

[Table 1]

[0031]

[Table 2]

From the above results, a comparison between Examples using ordinary steel balls (small-diameter spheres) and Examples 1 to 3 using resin-based sliding materials shows that the response acceleration is large when resin-based sliding materials are used. In addition, it shows a sufficient performance in preventing rocking (trigger) against the wind, and its response displacement is smaller than that of the steel ball.

From the above results, Example 1 is the most preferable example. The angle of inclination of the conical shape of the saucer is preferably 1 to 4 °.

[0034]

As described above, since the seismic isolation device of the present invention does not have a resonance point, it does not resonate with any earthquake and does not operate under normal vibrations caused by wind or the like. In addition, when the earthquake stops, it has a restoring force to return to the original position, and the effect that the design of the device is easy is achieved.

[Brief description of the drawings]

FIG. 1 is a plan view of a specific example of a base-isolated rolling bearing according to the present invention;

FIG. 2 is a partially cut-away side view of the apparatus of FIG. 1;

FIG. 3 is a partially cut-away side view of a specific example of a support used in the present invention;

FIG. 4 is an explanatory view of a conventional seismic isolation device,

FIG. 5 is an explanatory view of a conventional sliding seismic isolation device,

FIG. 6 is an explanatory view of a conventional rolling seismic isolation device,

FIG. 7 is a plan view of the device of FIG. 3 in which a steel ball cover and a large-diameter ball are removed.

FIG. 8 is an exploded view of a bearing body of the device of the present invention,

9 is a plan view of a sliding cup different from the apparatus of FIG. 7,

FIG. 10 is a perspective view showing the relationship between the sliding cup and the large-diameter sphere of FIG. 9;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 top plate 2 rubber layer 3 saucer fixing bracket 4 saucer iron plate 5 saucer installation jig 6 base plate 7 ball bear holder 8 reinforcing material 9 large diameter ball 10 phenol resin layer 11 tetrafluoroethylene layer 12 holder 13 grout material 14 L-type Anchor bolt 15 Steel ball cover 16 Small diameter ball 17 Spherical concave surface 18 Receiving tray 19 Low friction material 20 Medium 21 Bearing body 22 Rubber layer 23 Internal steel plate 24 External steel plate 25 Dowel pin 26 Lead plug 27 Mounting plate 28 Slip cup 29 Air vent path

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kurabayashi 3-5-3 Tatsumi, Koto-ku, Tokyo Engineering Department, Environmental Engineering Division, Mitsubishi Steel Corporation (72) Inventor Toshio Komi 3 Tatsumi, Koto-ku, Tokyo −5-3 Mitsubishi Steel Corporation Environmental Engineering Division Engineering Department (72) Inventor Nobuyuki Sone 3-5-3 Tatsumi Koto-ku, Tokyo Mitsubishi Steel Corporation Environmental Engineering Division Engineering Department (72) Inventor Takeshi Someya 3-5-3 Tatsumi, Koto-ku, Tokyo Engineering Department, Environmental Engineering Division, Mitsubishi Steel Corporation (72) Inventor Koichi Do 3-5-3, Tatsumi, Koto-ku, Tokyo Environment Engineering Division, Mitsubishi Steel Corporation Engineering Department (72) Inventor Akira Matsuda 3-5-3 Tatsumi, Koto-ku, Tokyo Mitsubishi Steel Corporation (72) Inventor Takashi Fujita 575-28 Nakano Hisagi, Nagareyama City, Chiba Prefecture

Claims (3)

[Claims] 1. A saucer having a conical recess, a bearing facing the saucer, the bearing having a spherical recess having a surface made of a low-friction material on a face opposed to the saucer, and having a spherical recess. A seismic isolation rolling bearing for a structure that is provided with a large-diameter sphere that slides into the depression, and the bearing body is configured to support a saucer via the large-diameter sphere. 2. The seismic isolation rolling bearing of a structure according to claim 1, wherein the angle of inclination of the cone of the receiving tray is 1 to 4 °, and the low friction material is an ethylene tetrafluoride resin. 3. The range of the trigger is constituted by selecting the conical inclination angle of the saucer, the diameter of the large diameter sphere, and the type and shape of the low friction material, and the maximum response acceleration is arbitrarily set. A seismic isolation rolling bearing for the structure according to claim 1 or 2.