JPH04154B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) This invention is applicable to, for example, the floor of a computer room, the floor where other important precision equipment is installed, or the room where dangerous substances such as explosives and chemicals are stored. It relates to floor seismic isolation devices used to reduce (seismic isolation) the seismic force applied to the floors of buildings and prevent equipment from stopping, being damaged, or creating dangerous situations. A movable support that supports the body horizontally with minimal resistance, and a restoring function after the same floor structure is moved.
Alternatively, the present invention relates to a floor seismic isolation device comprising a trigger function during movement and a damper action part that performs a damping function to prevent excessive movement (deformation).

(Prior art) For example, the floor seismic isolation device described in Japanese Patent Application Laid-Open No. 52-103823 has a sliding plate roughly fixed on the lower floor slab, a base plate slidably mounted on it, and A fulcrum portion of the floor structure is placed on a frame, and a horizontal coil spring and a horizontal damper, one end of which is fixed to a subfloor slab, are attached to the frame. In other words, it is a structure in which the movable support part of the floor structure and the damper action part are integrated into one.

In addition, JP-A-52-104324, JP-A-52-
The floor seismic isolation devices described in JP-A No. 104324 and JP-A-52-104325 are also based on almost the same principle structure.

In addition, the floor seismic isolation device described in Japanese Patent Publication No. 58-36144 uses a pedestal (that is, the floor structure itself) for fixing seismically isolated equipment, etc. to a rectangular horizontal platform with approximately similar planes. It is configured such that it is slidably placed within the platform via a low-friction element, and a horizontal coil spring and a horizontal damper are installed between the platform frame and the pedestal. This is also a structure in which the movable support part of the floor structure and the damper action part are integrated into one.

The floor seismic isolation device described in Japanese Patent Publication No. 58-36145 is also based on almost the same principle and structure.

(Problems to be solved by the invention) Regarding floor seismic isolation devices, it is generally necessary to reduce the response acceleration by making the natural frequency of the seismic isolation device smaller than the main frequency of external force, that is, by making the period longer. is the basic theory, and it is desired that the spring constant of the position restoring spring be as small as possible.

However, in the configuration of the conventional example described above, supporting the floor structure, that is, bearing the vertical load,
Since it is a composite structure that also functions to restore the position of the floor structure after it has been moved and to bear the burden of horizontal forces such as damping functions, it is unavoidable in actual construction due to cost requirements, space constraints, and work efficiency. The number of movable bearings is limited, and the vertical load of the floor structure applied to one floor seismic isolation device becomes relatively large. Therefore, the strength of the base slab that supports the movable support becomes a problem, and in some cases, it may be difficult to install a floor seismic isolation device without reinforcing the base slab in existing construction.

In addition, in the case of a bearing part using a sliding material as in the conventional example, the coefficient of friction is extremely large compared to a structure using a rolling material such as a bearing ball, and the resistance during horizontal movement in the movable bearing part is There is an upper limit to the position restoring force when using a restoring spring that is large and has an ideally small spring constant. That is, if a weak restoring spring is used, there is a problem that residual displacement occurs after movement.

In addition, in the conventional example above, a piston damper is used for the damping function to prevent excessive deformation (movement), but the piston damper has a fixed direction of operation, whereas the direction of movement due to earthquakes etc. Since it is difficult to predict, there is a problem in that it is difficult to ensure that the restoration and attenuation functions against the shaking of the floor structure due to earthquakes and the like are fully operational. Furthermore, since the floor structure (seismic isolation floor) supported by the movable bearing section causes large displacements, the stroke of the piston damper is required to be as long as 30 cm.
There is a problem in that a piston damper with a long stroke is extremely expensive.

(Means for Solving the Problems) As a means for solving the problems of the prior art, the floor seismic isolation device of the present invention basically has a floor structure, as shown in the drawings. A movable support part B that supports each fulcrum part of the body F, and a fixed floor C such as a floor structure F and a base slab, which are separated and independent from the movable support part B.
and a spring damper part A installed between the two to connect the two.

(a) The movable support part B is composed of a flat lower ball receiving steel plate 1 installed on the floor support part C, a bearing ball 3 placed in a free state on the ball receiving steel plate 1, and a floor structure F. It consists of a flat upper ball receiving steel plate 4 attached to the side and placed on the bearing balls 3.

(b) In addition, the spring damper section A has a highly rigid damper main body 10 in the shape of a shallow flat container attached and fixed to a fixed bed C, and a certain amount of viscous liquid 11 is accommodated within the damper main body 10. On the other hand, a flat movable member 12 whose lower surface is attached to the floor structure F side is substantially parallel to the bottom surface of the damper main body 10 is immersed in the viscous liquid 11 to form a certain gap between it and the bottom surface of the damper main body 10. d was secured. A rope-like member 1 that does not transmit compressive force to the other end of a tension or compression coil spring 13 whose one end is fixed to a fixed floor C such as a base slab.
4, and the other end of the rope-like member 14 is connected to the movable element 12, and the rope-like member 1
4 and the coil spring 13, the reaction force receiving roller 31 is brought into contact with the inner surface of the side wall 10a of the damper main body 10.

In the floor seismic isolation device of the present invention, in the most preferred embodiment, four coil springs 13 and rope-like members 14 are installed in four directions at right angles on a horizontal plane centered on the movable member 12, and A pre-tension or pre-compression force of a magnitude corresponding to the trigger external force value of the floor structure F is applied.

(Function) The movable support part B is configured to utilize the rolling of the bearing balls 3 so as to bear only the vertical load of the floor structure F. In particular, the bearing balls 3 are quenched and have sufficiently hard upper and lower ball receivers. Since it is interposed between the steel plates 1 and 4, there is no problem in bearing (transmitting) the vertical load, and since it rolls with minimal resistance, the spring constant of the coil spring 13 of the spring damper part A can be designed to be small.

Furthermore, since the bearing balls 3 move by only 1/2 of the stroke of the horizontal movement of the floor structure F, the diameters of the upper and lower ball-receiving steel plates 1 and 4 are such that the balls are attached to the moving side. It only needs to be about 1/2 to satisfy the same travel stroke as that of the previous model, and the area ratio can be as small as 1/4, making it possible to improve the economic efficiency of expensive heat-treated steel plates.

Next, the spring damper section A uses a tension coil spring 13 and The viscous resistance of the viscous liquid 11 is utilized.

As mentioned above, the coil spring 13 can be one with a small spring constant that is ideal for reducing the natural frequency of the floor seismic isolation device, for example, about 3 kg/cm, and has excellent seismic isolation performance. There is.

Further, the damping function is such that the liquid 1
Since it is performed as a viscous resistance of 1, there is no directionality at all, so it has excellent response performance to earthquake input whose directionality is unpredictable. Furthermore, the damping capacity can be adjusted over a wide range by adjusting the size of the gap d between the movable element 12 and the bottom surface of the damper main body 10. This is because the above-mentioned gap d means the size of dy in the equation expressing Newton's law of friction, τ=μ×du/dy, and it is clear that the size affects the size of the viscous resistance value. That's why.

Next, when a pre-tension force of about 10 kg is introduced into the coil spring 13, normally this pre-tension force is applied to the spring receiver on the fixed system floor C side and the side wall 10a of the damper main body 10 that the reaction force receiving roller 15 is in contact with. It acts only between the two, and does not exert any force on the movable element 12. Even if the floor structure F receives a horizontal force (earthquake input), it will not move unless the force exceeds the pre-tension of the coil spring 13. This is a so-called trigger function, and the trigger external force value can be freely set and adjusted as the pre-tension of the coil spring 13.

In other words, even if the floor structure F moves, the tensile force acts as a restoring action only for the coil springs 13 on the tension direction side, and conversely, for the coil springs 13 on the compression direction side, the simple force of the rope-like member 14 acts as a restoring action. Movement is completely absorbed as bending (sagging), and no force is transferred or received. Therefore, the trigger function properly exhibits its effect, and on the other hand, the trigger external force side can be set accurately.

(Embodiment) Next, a preferred embodiment of the present invention illustrated in the drawings will be described.

In Figures 1 to 9, B in the figure is the floor structure F.
A is a movable support part that supports each fulcrum part, and A is a spring damper part installed between the floor structure F and the fixed floor C for the purpose of restoring the position of the same floor structure F after movement. .

The floor structure F consists of a steel pedestal f ₁ assembled into a rigid planar shape and a floor panel f ₂ laid thereon (FIG. 3). Movable support parts B... are installed at the four corner fulcrum positions of the steel frame _f1 , and the steel frame _f1 is supported on the base slab C, which is the floor support part (Figs. 2 and 3).

The detailed structure is shown in Fig. 4A and B. On the base slab C, there is a shallow dish-shaped holding plate that houses and restrains a hardened flat lower ball receiving steel plate 1 with a diameter of about φ300. A container 1' is fixed and installed with anchor bolts 5, 5.

As the bearing balls 3, seven balls with a diameter of about 16 mm are used (Fig. 4B), and after they are evenly distributed and restrained and held by retainers 3', they are placed on the lower ball receiving steel plate 1. It is placed approximately in the center.

On the other hand, a support ring 6 with a shallow dish-shaped retainer 3' attached downwardly to the lower surface is installed at the fulcrum part of the steel frame groove _f1 with bolts 7, and an upper ball receiving steel plate housed in the retainer 3' is attached to the supporting ring 6. 4 is placed on the bearing ball 3. This upper ball receiving steel plate 4 is also a hardened flat disk with a diameter of about φ300.

Therefore, the floor structure F can freely move horizontally with a very small coefficient of friction due to the rolling motion of the bearing balls 3, and only the vertical load is supported by the movable support parts B having the above configuration installed at its four corners.
Therefore, a series of floor surfaces are formed between the surrounding fixed floor f ₃ and the buffer floor section f ₄ that can rise and fall freely (the third
figure).

In addition, if the vertical load borne by one movable support part B becomes too large, it is necessary to further increase the number of supports of the floor structure F, or change the support positions in areas where there are concerns about the strength of the base slab C. The movable support part B can be installed at a different (shifted) location where there is no need to worry about strength.

By the way, the principle structure of the movable support part B is that the bearing ball 3 is simply sandwiched between the upper and lower ball receiving steel plates 4 and 1, as shown schematically in FIG. 5A. When a horizontal movement occurs, a/2 stroke of the movement is covered by the movement of the bearing ball 3 (FIG. 5B). Therefore, in the end, the diameter of the upper and lower ball receiving steel plates 4, 1 is sufficient to be the dimension a, and it can be constructed at low cost and in a small size despite the large horizontal movement stroke.

However, for this movable support part B, it is also possible to adopt a conventional general bearing ball type support part.

Next, two spring damper units A are installed at the left and right positions in the center of the floor structure F (Figure 2).The detailed configuration is as shown in Figures 7 and 8 A and B. A damper main body 10 in the shape of a shallow steel container with a circular inner diameter of about 650 mm and a height of about 100 mm is horizontally fixed on a base slab C, which is a fixed floor, with anchor bolts 16 and nuts 17. There is.

Inside this damper main body 10, a viscous liquid 11 such as a polymeric viscous substance such as silicone is disposed at a depth.
It is accommodated in an amount of only about 20mm.

On the other hand, a damper receiving pedestal 18 is installed horizontally on the steel frame f ₁ of the floor structure F by bolting, and a movable element supporting pedestal 19 is attached to a hanging bolt 20 , a nut 21 screwed into the suspension bolt 20 , and a holding bolt 22 at the lower center of the damper receiving pedestal 18 . It is attached and fixed by a lock nut 23. In other words, the height of the movable element support base 19 and, by extension, the movable element 12 can be adjusted by operating the hanging bolts 20 and the holding bolts 22.

The mover 12 has a thickness of about 6 mm and a diameter of φ150, for example.
This is a steel disc with a diameter of 1.5 mm, which is removably attached to the lower ends of the four rods 24 with screws 24a. The upper end of the rod 24 is connected to the movable element support base 19.
is attached to. Thus, the movable element 12 is placed parallel to the bottom surface 10b of the damper main body 10 with a gap d of about 10 mm in between, and the movable element 12 is immersed in the viscous liquid 11. The gap d can be adjusted using the hanging bolt 20 and the holding bolt 22 as described above. Furthermore, the movable element 12 can be converted to a diameter corresponding to the required damping performance by operating the screw 24a.
As a result, the equation of Newton's friction law mentioned above τ=
Shear stress τ=S/A(S
The area A (where A is the horizontal force and A is the area) is adjusted, and the magnitude of the damping performance is adjusted.

By the way, the damping force was 34 kg when the vibration speed was 20 cm/s, the temperature was 20° C., the diameter of the mover 12 was φ150, and the viscous liquid 11 was silicone oil.

Next, reference numeral 13 in the figure is a tension coil spring with a spring constant of about 3 kg/cm and a length of about 600 mm.A tension adjustment bolt 25 is connected to the outer end of the spring, and it is attached to the base slab C, which is the fixed floor. The tension adjustment bolt 25 is fixed with an adjustment nut 28 to a support angle 27 fixed with an anchor bolt 26. That is, the strength of the coil spring 13, that is, the magnitude of the pre-tension force, can be adjusted by adjusting the screwing amount of the adjustment nut 28.

The inner end of the coil spring 13 has a width of 20 mm and a length of 250 mm.
A connecting rod 29 made of a flat steel plate of approximately mm in diameter is connected, and the connecting rod 29 passes through a slit 30 formed in the circumferential direction at a portion of the vertical side wall 10a of the damper main body 10 that is higher than the liquid level of the high viscosity liquid 11. It is inserted into the main body 10. and,
A reaction force receiving roller 31 attached to the inner end of the connecting rod 29 is in contact with the inner surface of the side wall 10a. Therefore, the pre-tension of the coil spring 13 acts only between the support angle 27 and the side wall 10a during normal times, and does not reach the movable element 12.

In the figure, reference numeral 14 denotes a roller chain which is a rope-like member that does not transmit compressive force, and one end of which is connected to the connecting rod 29.
The other end is connected to a flat plate 32 which is integral with the rod 24 of the movable element 12. This roller chain 14 extends from the inner end of the connecting rod 29 to the flat plate 3.
The length is equal to the distance between the connecting points up to 2.

As shown in FIG. 7, the coil springs 13 and the like are installed in four directions at right angles to each other with the mover 12 at the center. In order to deal with the uncertainty of the directionality of earthquake input, a slit 3 is inserted through which the connecting rod 29 is passed.
0 is formed at an arc angle of approximately 80° in the circumferential direction. Further, the coil spring 13 is supported by a sliding plate 33 in order to cope with horizontal deflection and vertical slack.

However, the coil spring 13 and the like are not connected to the movable element 1.
It is also possible to have a configuration in which three wires are installed in three directions at equal angular intervals of about 120° with No. 2 at the center.

The principle structure and operating state of this spring damper part A are schematically shown in FIGS. 9A, B, and C, and the floor structure F
When a horizontal external force is applied to the (steel frame f ₁ ) and the mover 12 tries to move, the coil spring 13 on the side that is being pulled resists, and the external force exceeds the pre-tension tension (for example, about 10 kg) set in advance as the trigger external force value. Movement is prohibited unless otherwise. This is the trigger function.

On the other hand, regarding the compression side coil spring 13, the roller chain 14 is bent and does not transmit any compression force (FIG. 9B). Therefore, only the magnitude of the pre-tension force set in the tension-side coil spring 13 functions accurately as the trigger external force value. Its size can be adjusted by means of tension adjustment bolt 25 and adjustment nut 28.

When the mover 12 is moved by an external force exceeding the pre-tension force of the coil spring 13, the spring force on the tension side acts as a position restoring force (FIG. 9C). That is, it is a position restoration function after movement.

Further, when the movable element 12 moves as described above, a damping function is activated to prevent excessive movement due to the viscous shear resistance of the high viscosity liquid 11.

(Second Embodiment) FIG. 10 shows an example of a planar arrangement of a floor seismic isolation device implemented on a floor with a large planar area.

That is, the number of support points on the floor is increased as necessary, movable support sections B are installed at each position, and the number of spring damper sections A is also increased.

(Embodiment of FIG. 3) FIG. 11 shows an example of a spring damper section A using a compression coil spring 13'.

That is, the coil spring 13' is housed in a spring casing 35 whose outer end is attached to the base slab C via a flexible receiver 38 to remove support and reaction force, and the inner end of the coil spring 13' is screwed into the spring casing 35. The spring receiver 39 is brought into contact with the lower spring receiver 39. A spring receiver 36 that comes into contact with the outer end of the coil spring 13' is attached to the tip of a connecting rod 29 passed through the hollow portion of the coil spring 13'. In other words, the trigger external force value is applied as a precompression force depending on the screwing amount of the spring receiver 39.

Therefore, the principle of operation is the same as that of the tension coil spring 13 shown in FIG. 7, and it can be used in exactly the same way.

(Effects of the Invention) As described above in detail together with the embodiments, according to the floor seismic isolation device of the present invention, the floor structure F
The movement support part B of the floor structure F and the spring damper part A for horizontal movement are each configured separately and independently.
Since each supporting point is supported only by the movable bearing part B, there is a high degree of freedom in design and construction, regardless of the size of the floor area, planar shape, or amount of load. It has excellent work procedures and ease of construction, and the total cost can be made low.

Moreover, it is possible to easily design and construct a structure that limits the vertical load borne by one movable support part B to a small value, so that the resistance during horizontal movement of the floor structure F can be made extremely small. It is possible to use a restoring coil spring 13 with an ideally small spring constant, and a floor with excellent seismic isolation performance can be constructed.

In addition, the spring damper part A has a function of restoring the position after moving the floor, a trigger function during movement, and a damping function.
does not bear any vertical load, the pre-tension set on the coil spring 13 acts completely accurately as a trigger external force value, and its adjustment is easy.

Moreover, since the damping function utilizes the viscous shear resistance of the high viscosity liquid 11, there is no particular directionality, and it works equally in all 360° directions, so it is effective against earthquake input whose directionality is unpredictable. It works perfectly and has high reliability. Furthermore, since the damping capacity can be adjusted by adjusting the size of the gap d between the movable element 12 and the bottom surface of the damper main body 10, excellent seismic isolation performance can be expected as a comprehensive effect of the above.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing the implementation state of the floor seismic isolation device of the present invention, Fig. 2 is a plan view of the main structure of the seismic isolation floor, and Fig. 3 is viewed from the − arrow in Fig. 2. figure,
Figures 4A and B are vertical and horizontal cross-sectional views of the movable support, Figures 5A and B are illustrations of the principle of operation of the movable support, Figure 6 is a view taken in the - arrow direction of Figure 2, and Figure 7 is A plan view of the spring damper part, Figures 8A and B are vertical sectional views of the entire spring damper part and main parts, Figure 9
Figures A, B, and C are diagrams of the principle of operation of the spring damper section, Figure 10 is a plan layout of the seismic isolation floor, and Figure 11 is a plan view of different structural examples of the spring damper section.

Claims (1)

[Claims] 1. Movable support portion B that supports each fulcrum portion of the floor structure F.
and a spring damper part A that is separate and independent from the movable support part B and is installed between the floor structure F and the fixed system C so as to connect them, (a) a movable support part; B includes a flat lower ball receiving steel plate 1 installed on the floor support part C, and a bearing ball 3 placed on the ball receiving steel plate 1;
and an upper ball receiving steel plate 4 attached to the side of the floor structure F and placed on the bearing balls 3; (b) The spring damper part A is a damper in the shape of a shallow flat container. A main body 10 is attached and fixed to a fixed system C, and a certain amount of viscous liquid 11 is accommodated in the damper main body 10, and a movable element 12 with a flat lower surface attached to the side of the floor structure F is immersed in the viscous liquid 11. A rope-like member 14 that does not transmit compressive force is connected to the other end of the coil spring 13, which is immersed to ensure a certain gap d between it and the bottom surface of the damper main body 10, and whose one end is fixed to the fixing system C. The other end of the rope-like member 14 is connected to the movable element 12, and the reaction force receiving roller 31 attached to the rope-like member 14 is connected to the damper main body 1.
1. A floor seismic isolation device characterized by: being in contact with an inner surface of a side wall 10a of a base plate. 2. The coil spring 13 described in claim 1 is a tension or compression spring, and a pre-pulling tension or pre-compression force corresponding to the trigger external force value is applied to the coil spring 13. A floor seismic isolation device characterized by: 3. A floor characterized in that the coil spring 13 and the rope-like member 14 described in claim 1 or 2 are installed in four orthogonal directions on a horizontal plane centered on the movable element 12. Seismic isolation device. 4 The coil spring 13 and the rope-like member 14 described in claim 1 or 2 are connected with a rigid connecting rod 29 interposed therebetween, and the connecting rod 29 has a reaction force receiving member. A floor seismic isolation device characterized in that a roller 31 is attached.