JPS60211142A - Quake damping device - Google Patents

Abstract

PURPOSE:To reduce seismic force so sharply, by mounting a frame horizontally on the foundation of machinery and equipment, while setting up laminated rubber between the frame and the foundation. CONSTITUTION:A frame 2 is mounted horizontally on the base of a quake damping device, while hour sets of balls 3 are set up on a lower surface of the frame 2. Laminated rubber 6 has each of square upper and lower flanges 8 in its upper and lower ends either. Now supporting that the frame 2 is displaced with the base 1 as it receives seismic force, laminated rubber 6a located at the displaced side comes off the frame 2 but another laminated rubber 6b at the opposite side is deformed to some extent as the upper flange 7 is pulled to an engaging part of the frame 2, thus restoring force comes to be produced there in consequence.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a seismic isolation device for preventing seismic force from being transmitted to equipment or structures.

[Prior art and its problems]

There are two main types of conventional seismic isolation devices:

(a) A smooth surface plate is installed on the foundation 15 of the equipment or structure, a pedestal whose lower surface is made up of the friction member 16 is placed on top of this, and a tensile structure with one end fixed to the foundation is placed around the pedestal. A seismic isolation device that connects and supports coil springs (
Figure 1).

・(b) A rectangular pedestal is placed on a fixedly arranged horizontal pedestal frame 18 via rollers or balls,
An L-shaped spring connection jig 19 is placed on each corner of the frame, and the opposing ends of each jig are interconnected by tension springs arranged along each side of the frame. Stopping jigs 20 are provided on the top surface of the stand at positions corresponding to the normal position of the stand, and these stoppers prevent the spring connection jigs connected to each other by tension springs from moving toward each other. A seismic isolation device (Figure 2).

In the seismic isolation device (a), since the frictional force between the pedestal and the foundation is used as a trigger for starting relative motion, the pedestal remains stationary without returning to its normal position C2 after the earthquake. Therefore, it has the disadvantage of requiring special return work.

On the other hand, in the seismic isolation device (b), since the pre-tension force of the tension dicoil spring is mainly used as a trigger, the pedestal automatically returns to its normal position after the earthquake ends. However, since the four tension Kucoil springs are connected in a loop, if one of them were to break, all four would become unusable, which could have a major impact on seismic isolation performance. be. Furthermore, since both use tension coil springs, special jigs and work are required to install the coil springs at the installation site.

[Purpose of the invention]

The present invention was made in view of the above-mentioned circumstances, and does not require any special jigs or work to assemble the seismic isolation device at the installation site, and automatically returns to its normal position after an earthquake.
Moreover, it is an object of the present invention to provide a highly reliable seismic isolation device that can significantly reduce the seismic force acting on equipment or structures during an earthquake.

[Summary of the invention]

The present invention allows a pedestal to be placed horizontally on the foundation of equipment or a structure so that it can easily move, and the equipment or structure to be seismically isolated is fixed onto this pedestal. In addition, between the pedestal and the foundation (2.), the laminated rubber is placed between the pedestal and the foundation (2) to give initial deformation in a specific direction and to prevent its restoration, so that the pedestal does not move relative to the foundation due to the action of seismic force. It is a seismic isolation device arranged so that it will undergo shear deformation when the earthquake occurs.

〔Effect of the invention〕

The seismic isolation device according to the present invention can be used to significantly reduce the seismic force that acts on equipment or structures during earthquakes, and does not require special jigs or work to assemble at the installation site. In addition, the pedestal automatically returns to its normal position after an earthquake, which provides excellent effects.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described based on all the drawings.

5 and 6 show one embodiment of the seismic isolation device according to the present invention. Reference numeral 1 denotes a base of a seismic isolation device fixed on the foundation of equipment or a structure, and a pedestal 2 is placed horizontally on top of this. On the underside of this pedestal 2, there are four sets of balls 3.
and a ball case 4 are arranged, and ball receiving plates 5 are arranged on the upper surface of the base 1 at positions corresponding to each of the four balls 3. 6 pieces, laminated rubber,
It has a square upper flange 7 and a square lower flange 8 at both the upper and lower ends. This lower flange 8 is connected to the base 1
The upper flange 7 is fixed to the four corners of the upper surface, and the upper flange 7 is in contact with the downward flange-shaped engaging portions 9 provided at the four corners of the pedestal 2 at two sides along the outer circumference ζ2 of the seismic isolation device. The laminated rubber is fixed in a preloaded state at the upper flange 7 and the lower flange 8 along two sides near the center of the seismic isolation device, protruding downward and upward, respectively, into a retaining jig 10. and the lower stop jig 11 are engaged with each other.

FIGS. 7 and 8 show a case where the pedestal 2 is displaced relative to the base 1 in response to an earthquake force in the above-mentioned seismic isolation device. In such a case, the laminated rubber 6a on the side to be displaced is separated from the pedestal 2, and the laminated rubber 6b on the opposite side is deformed by the flange 7 being pulled by the engaging portion 9 of the pedestal 2, and the restoring force is applied. The mechanism is such that this occurs. Note that by setting the shear rigidity of the laminated rubber 6 so that the natural frequency of this horizontally laminated rubber system is smaller than the frequency of the external force, an excellent seismic isolation effect can be obtained.

FIG. 9 shows a conventional laminated rubber, in which the rubber plate 12
and a metal plate 13 are superimposed perpendicularly to that surface.

FIG. 10 shows the laminated rubber 6 used in the above embodiment.
It shows the state before applying the preload, and their axes are tilted and overlapped in advance. FIG. 11 shows a top stop jig 9 and a bottom stop jig 10 fixed to the top flange 6 and bottom flange 7 with a load applied to the laminated rubber 5 shown in FIG. 10 so that its axis is perpendicular to the plate surface. are engaged with each other. Moreover, since the preloaded laminated rubber can be manufactured at a factory, assembly work at the installation site is easier than with conventional seismic isolation devices that employ tension coil springs.

FIG. 12 shows a load-displacement diagram when the pedestal 2 is displaced relative to the base 1 in the above-mentioned seismic isolation device. In the figure, the horizontal axis represents the displacement Xt-1, the vertical axis represents the load P, and the preload trFo generated by displacing the laminated rubber 6 in advance, the static friction force 1Ffr, and the total mass of the upper part of the ball 3'ftm Then, unless the input acceleration A is A>(Fo+Ffr)7m, the pedestal 2 will not move. −j, that is, the minimum value for this person becomes the trigger acceleration. Furthermore, from the same figure, it can be seen that the pedestal 2 automatically returns to its original normal position after the earthquake ends.

13 and 14 show an example in which a plurality of the above-mentioned seismic isolation devices are arranged and a large-area floor 14 is placed thereon.

[Other embodiments of the invention]

Figures 15 and 16 show another embodiment of the invention.

In this embodiment, preloaded laminated rubber is placed outside the periphery of the frame.

Note that a three-dimensional seismic isolation device can be obtained by mounting a vertical seismic isolation mechanism on the pedestal.

[Brief explanation of drawings]

1 and 2 are a plan view and a sectional view of a first conventional seismic isolation device, FIGS. 3 and 4 are a plan view and a sectional view of a second conventional seismic isolation device, and FIG. Figures and Figure 6 are
This shows a seismic isolation device according to an embodiment of the present invention, and the plan view and sectional view when the pedestal is in its normal position, and FIGS. 9 and 10 are side views of the laminated rubber with no preload applied, and FIG. 11 is a side view of the laminated rubber with a preload applied. , 1st
Figure 2 is a diagram showing the relationship between the preload, frictional force, and displacement of laminated rubber, and Figures 13 and 14 are diagrams showing the relationship between the preload, frictional force, and displacement of laminated rubber. The plan view and cross-sectional view of the seismic device, FIGS. 15 and 16, are
FIG. 7 is a plan view and a cross-sectional view of another embodiment of the present invention. 1... Base 2... Frame 3... Ball 4... Ball case 5... Ball holder is plate 6... Laminated rubber 7... Upper flange 8...
・Lower flange 9...Engagement part 10...Top stop jig 1
1... Bottom stop jig 12... Rubber plate 13... Metal plate 14... Floor 15... Foundation 16... Friction member 17... Tension coil spring 18... Stand < 19...Spring connection jig 20...Stopping jig Agent Patent attorney Kensuke Chika (and 1 other person) No. 3
Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 ° Figure 10 Figure O Figure 11 Figure 12 Figure P Figure 13 Figure 14

Claims (1)

[Claims] On the foundation, along with the equipment or structure to be seismically isolated, a laminated rubber is installed on the upper surface to prevent it from restoring, so that it will be sheared and deformed when the frame moves relative to the foundation. A seismic isolation device characterized in that a movable support mechanism having a low friction member is installed between the lower surface of the pedestal and the upper surface of the foundation.