JP2021085182A - Spring type vibration control damper - Google Patents

Abstract

To provide a spring type vibration control damper capable of preventing excessive deformation of a laminated rubber base isolation device at the time of a huge earthquake and preventing damage of the laminated rubber by imparting a quick deformation restoring function.SOLUTION: A spring type vibration control damper 11 comprises: a cylinder 18 mounted between an upper structure and a foundation structure of a base isolation building structure having a base isolation device interposed between the upper structure and the foundation structure and provided with end plates 23, 24 at both ends; a rod 22 mounted with a piston 21 at the tip; and a coil spring 19 housed in the cylinder 18. The piston 21 is housed in the cylinder 18, one end of the coil spring 19 is fixed to the end plate 23 of the cylinder 18, the other end is fixed to the piston 21, and relative displacement between the upper structure and the foundation structure due to an earthquake is returned to an original position by compression of the coil spring 19.SELECTED DRAWING: Figure 3

Description

The present invention relates to a spring type vibration damping damper used by being attached to a seismic isolation structure.

Several techniques have been known for this type of damping damper.
Regarding the first known technique, a piston having a convex cross section including a shaft is slidably fitted to an oil-filled cylinder, and a cylindrical body into which the small diameter portion of the piston is fitted is fitted to one end of the cylinder. The piston is formed with an oil hole provided with a check valve that is fitted and fixed to the portion and closed when the piston moves toward the end portion, and a minute oil hole that communicates with both sides in the large diameter portion of the piston. However, when the small diameter portion of the piston is fitted into the cylinder, the airtight oil chamber formed inside the cylinder communicates with the cylindrical oil chamber formed between the cylinder and the small diameter portion of the piston. An oil damper provided with a minute oil passage (see Patent Document 1).

The damper according to the first known technique generates an extremely large damping force only in an appropriate part range during the entire stroke. Therefore, it can be directly connected to a window, a door, or the like and used with a simple mechanism. Moreover, since the cylindrical body is simply fitted to the cylinder and the piston is formed in a convex shape, the structure can be easily manufactured.

Regarding the second known technique, a cylinder, a spring body (spiral coil spring) housed in the cylinder and for controlling deformation of the laminated rubber, and one end in the axial direction of the cylinder. It is provided with a rod that is movably inserted into the body, the other end of which extends from the end of the cylinder, and has a holding portion that presses the spring body, and the length of the cylinder is at least that of the laminated rubber. It is a stopper in a seismic isolation structure, which is characterized by adding an allowable deformation amount and a length capable of accommodating a spring body (see Patent Document 2).

In the stopper according to the second known technique, when the laminated rubber G tries to be excessively deformed due to an unexpected earthquake input, the holding portion of the rod comes into contact with the spring body and the excessive deformation is controlled by the spring force. That is.

The third known technique is provided between the first structure and the second structure that move relative to each other, and generates a damping force to dampen the relative movement between the first structure and the second structure. The damping means is provided between the first structure and the second structure to generate a damping force larger than that of the damping means, and the relative movement between the first structure and the second structure is performed. The damping means is inserted into the cylinder accommodating the fluid and the cylinder, and is inserted into the cylinder as the first structure and the second structure move relative to each other. When the relative movement between the rod to be inserted and removed and the rod provided on the rod and the first structure and the second structure exceeds a predetermined value, the pressed portion provided on the stopper means is pushed to apply a damping force. It is a damping device including a pressing portion to be generated (see Patent Document 3).

According to the damping device according to the third known technique, the rod is inserted and removed from the cylinder as the first structure and the second structure move relative to each other. As a result, the damping means generates a damping force, and the relative movement between the first structure and the second structure is damped. Further, when the relative movement amount between the first structure and the second structure exceeds a predetermined value, the pressed portion provided on the stopper means is pushed by the pressing portion provided on the rod, and the stopper means is used as the damping means. Generates greater damping force. As a result, the relative relationship between the first structure and the second structure is further attenuated. That is, the damping means generates a damping force for an expected earthquake or the like, and a stopper means damping force is generated together with the damping means for an earthquake or the like more than expected. Therefore, while maintaining the vibration damping efficiency against an unexpected earthquake or the like, the stopper means can function as a cushioning material in the event of an unexpected earthquake, and excessive deformation of the first structure and the second structure can be suppressed. That is.

Public notice of Jitsukosho No. 51-774 Public Notice of Jitsufuku No. 3-23004 Publication of Japanese Patent Application Laid-Open No. 2011-47421

Laminated rubber seismic isolation devices are often used for seismic isolation structures, but the laminated rubber seismic isolation devices themselves cannot absorb the energy of earthquakes and deform along the swing width to suppress the swing width. In order to prevent this, it is necessary to install a vibration control damper and use it together with a laminated rubber seismic isolation device. Among the vibration control dampers, the oil damper is often used because it can convert seismic energy into heat energy to reduce the shaking of the entire building. It is one of them.
However, although the oil damper can absorb seismic energy but does not have resilience, it cannot be restored to its original state with respect to the relative displacement of the upper and lower structures that occurred during the earthquake, and the laminated rubber. It is returned by the elastic deformation force of the seismic isolation device, which increases the burden on the laminated rubber seismic isolation device, and has a problem that the seismic isolation rubber is excessively deformed and destroyed. There is also the danger that oil dampers will explode and destroy buildings if exposed to high temperatures during a fire.

In Patent Document 2, it is possible to suppress excessive deformation of the laminated rubber by using the oil damper and the stopper side by side, but it is indispensable to use the stopper and the oil damper together. Therefore, in the technique of Patent Document 2, not only twice as much material is required and material is wasted, but also twice as much labor and time are required for the mounting work, and the spring body is separated from the holding portion. Since it is installed as a beam, the spring body will buckle when it receives repeated seismic forces, and if it is slanted or the tip is loose, it will rub against the wall of the cylinder and cannot move in parallel. However, once buckled, the device cannot operate normally after that, and in short, the stopper function is lost, and there is a problem that continuous use becomes impossible.

In the technique of Patent Document 3, since it is necessary to provide a damping means by a fluid such as oil and a stopper means by a spring in the damping device, the configuration is complicated, the number of parts is increased, and the cost is increased, as well as oil and the like. Since a fluid is used, the danger in the event of a fire cannot be avoided as in Patent Document 1.
Further, since it is indispensable to provide a sealing member such as an O-ring for preventing fluid leakage of oil or the like in the insertion hole of the rod, the cost of the device is also high. Even if the air damper is made of gas (air) instead of liquid (oil), there is a problem that the cost is similarly high because the sealing of gas leakage is also required.

Therefore, the present invention solves all the problems in the prior art, has a function of absorbing seismic energy without using any fluid such as oil, and a stopper function of preventing excessive deformation of the laminated rubber seismic isolation device. It is an object of the present invention to provide a seismic isolation damper having three functions, that is, a deformation restoration function that quickly restores the deformation of a structure due to an earthquake.

As a specific means for solving the above-mentioned problems of the conventional example, the invention according to the present invention is a damper used for a seismic isolation building structure in which a seismic isolation device is interposed between a superstructure and a foundation structure. The damper includes a cylinder provided with end plates at both ends, a rod slidably arranged in the cylinder and a piston attached to one end, and a pair of springs provided on both sides of the piston. , Each of which is composed of an elastic cushioning material installed inside both end plates, one end of the spring is fixed to the piston, and a clearance portion is provided between the other end and the elastic cushioning material. When the relative displacement with the basic structure exceeds the clearance, the elastic reaction force generated by the compression of the spring absorbs the seismic energy, the stopper function to prevent excessive deformation of the seismic isolation device, and the seismic isolation after the earthquake. It provides a spring-type seismic isolation damper characterized by having a structure having a function of restoring the deformation of a seismic building.

In the above invention, the clearance portion is set to 70 to 80% of the limit deformation allowable value of the seismic isolation device, and the spring is brought into close contact immediately before the relative displacement reaches the limit deformation allowable value of the seismic isolation device. The spring is a coil spring, and a plurality of anti-skid materials are installed inside the spring with a required gap over the entire length of the cylinder; and the spring has at least two different spring constants in a series. It includes the combination in the length direction as an additional requirement.

According to the spring type vibration damping damper according to the present invention, the following effects can be obtained.
1. By providing a gap between the spring and the elastic cushioning material, if the relative displacement (extension or contraction of the relative distance) due to the earthquake between the superstructure and the foundation structure does not exceed the gap, it is exempted. By freely horizontally deforming within the elastically deformable range of the seismic device, the seismic force on the superstructure becomes very small and the superstructure is not affected by the earthquake. In short, in the event of a small or medium-sized earthquake, a normal laminated rubber type seismic isolation device can respond because it has horizontal deformation ability. Therefore, in small and medium-sized earthquakes, the number of turns, diameter, and strength of the springs of the spring-type seismic damping damper can be adjusted by restoring the seismic isolated building after the earthquake to its original state by utilizing the restoring force of the laminated rubber type seismic isolation device. It is possible to reduce the size and cost of the spring-type seismic isolation damper itself.
2. When the relative displacement (extension or contraction of the relative distance) between the superstructure and the foundation structure due to a large earthquake exceeds the free space, the spring abuts on the elastic cushioning material and is compressed, resulting in an elastic reaction force on the spring. Occurs. This elastic reaction force provides the function of absorbing seismic energy. Subsequently, when the relative variate reaches a predetermined value, the coil spring is in a state of being compressed and brought into close contact with each other, and the relative movement of the piston in the cylinder is stopped, so that the relative displacement between the superstructure and the foundation structure is restricted and seismic isolation occurs. A stopper function is obtained to prevent excessive deformation of the device. Furthermore, with respect to the relative displacement between the superstructure and the foundation structure due to the earthquake and the rubber deformation of the seismic isolation device, the deformation of the seismic isolated building after the earthquake is quickly restored by the spring elastic reaction force generated by the compression of the coil spring. Restoration function is obtained. In other words, unlike the conventional technology, it is not necessary to install both a stopper and a damper, and one device has three functions: a seismic energy absorption function, a stopper function to prevent excessive deformation of the seismic isolation device, and a deformation restoration function. Become a seismic damper. The above-mentioned predetermined value is preferably a limit deformation allowable value of the laminated rubber seismic isolation device.
3. The above-mentioned deformation restoration function is that an elastic reaction force (restoring force) is generated by compression of a spring. In the event of a large earthquake, when the relative displacement between the superstructure and the foundation structure exceeds the gap and the laminated rubber seismic isolation device is significantly deformed, elastic reaction force is generated and suppressed by compression of the spring. In short, in the event of a large earthquake, the large deformation received by the laminated rubber seismic isolation device can be suppressed by the restoring force of the spring, and if the deformation becomes small to the play space, it can be restored by the elastic restoring force of the seismic isolation device itself. Even if the seismic isolation device receives repeated horizontal forces, the laminated rubber of the seismic isolation device can prevent deterioration due to load fatigue, and the service life of the seismic isolation device can be extended.
4. Further, the play space is set to 70 to 80% of the limit deformation allowable value of the laminated rubber type seismic isolation device, and the spring is released just before the relative displacement between the superstructure and the basic structure reaches the limit deformation allowable value of the seismic isolation device. By making them in close contact with each other, not only is it possible to respond to a huge earthquake envisioned in the design with a margin, but even if an unexpected huge earthquake occurs, it suppresses excessive deformation of the seismic isolation device and seismic isolation is achieved. It is possible to prevent damage to the device itself and greatly improve the safety of the entire seismic isolated building structure.
5. By installing the anti-buckling material, it is possible to prevent the spring from becoming unable to expand and contract in the axial direction of the cylinder due to buckling and tip bending even if it receives repeated earthquakes and strong winds. In particular, buckling and tip bending can be prevented even with a spring attached in the form of a cantilever.
6. Further, by not using any fluid such as oil, it is only necessary to provide a hole through which the rod can penetrate in the end plate of the cylinder, so that it is not necessary to take measures against oil or gas leakage, and the configuration is simple and can be provided at low cost.

It is a side view which showed only the main part of the seismic isolation structure to which the spring type vibration damping damper which concerns on this invention is attached. It is a top view which showed only the main part of the seismic isolation structure. It is sectional drawing in the attached state of the spring type vibration damping damper of the Example which concerns on this invention. FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG. It is an enlarged sectional view which shows an example of the main part of the attachment state of the buckling prevention material in the spring type vibration damping damper of the Example which concerns on this invention. It is an enlarged cross-sectional view of another example which shows the main part of the attachment state of the buckling prevention material in the spring type vibration damping damper of the Example which concerns on this invention. Figures (a), (b), and (c) are explanatory views of the relative displacement between the foundation structure and the superstructure when the spring-type vibration damping damper of the same embodiment receives an earthquake. It is a graph which showed the characteristic of the coil spring in the same Example.

Examples of the present invention according to the illustrated embodiment will be described. First, FIGS. 1 and 2 will be described. Generally, as a seismic isolation structure, as shown in FIGS. 1 and 2, an upper structure 2 is constructed on the foundation structure 1, and the foundation structure 1 has a plurality of foundation piles 4 on the ground 3. , A rapple foundation 5 is formed on each of the foundation piles 4, and a concrete mat slab 6 is formed between the foundation piles 4. In the superstructure 2, a footing 8 is installed between the superstructure 2 and the rapple foundation 5 via a laminated rubber type seismic isolation device 7, and a girder (underground beam) 9 is arranged between the footings 8. A pillar 10 is built on the upper surface of the footing 8, and a beam, a slab, a wall portion (not shown) and the like are sequentially formed to construct the superstructure 2.

The spring-type seismic damping damper 11 according to the present invention is attached between the foundation structure 1 and the superstructure 2 to the seismic isolation structure constructed in this manner, and the attachment is on the foundation structure 1 side. Between the support base 12 provided on the (mat slab 6) and the support base 13 provided on the upper structure 2 side (girder 9) via mounting bases 14 and 15 made of steel metal fittings and connecting pins 16 and 17. The spring-type seismic isolation damper 11 is installed so that it can freely rotate horizontally and in the left-right direction. Although not shown, the spring-type vibration damping damper 11 can be mounted so as to be able to rotate in the vertical and horizontal directions by forming the mounting bases 14 and 15 into a spherical connecting structure.

As shown in FIGS. 3 to 8, the spring-type vibration control damper 11 of the specific embodiment according to the present invention has the coil spring 19 and the buckling of the coil spring 19 inside the cylinder 18 having the required length. A plurality of buckling prevention members 20 to be prevented and a piston 21 are arranged, and the piston 21 is connected (attached) to the tip of the piston rod 22 and slidably arranged in the cylinder 18, and the piston rod is slidably arranged. The rear end of the 22 is arranged so as to protrude from the one end side of the cylinder 18 by a required length, and the protruding end of the rod 22 is attached to the support base 12 by the connecting pin 16 and the mounting base 14.

Regarding the arrangement of these members in the cylinder 18, end plates 23 and 24 made of steel metal fittings are firmly attached to both ends of the cylindrical cylinder 18 by welding or the like, respectively. Is provided with a plurality of holes to which a plurality of buckling prevention members 20 are attached, and in the illustrated embodiment (see FIGS. 4 to 6), four holes or screw holes 25 are provided in advance near the peripheral edge at equal intervals. The head portion of the buckling prevention member 20 made of four round steels is inserted so as to abut against the end plate 23 provided on the side (left side in FIG. 3), and the insertion end portion is screwed into the screw hole 25 on the right side. The end is projected from the cylinder 18 to the required length by fixing or inserting it into the hole, and the nut 28 is screwed into the protruding end to fix the buckling prevention member 20 over the entire length of the cylinder 18. The coil spring 19 is arranged so as to hold the buckling prevention member 20 inside with a required gap. The piston 21 is also provided with an insertion hole 26 through which the buckling prevention member 20 is inserted, and the rear end portion of the piston rod 22 is required to be inserted from the cylinder 18 through the insertion hole 31 provided in the end plate 24. The length is projected.

Further, as shown in FIG. 3, the piston 21 attached to the piston rod 22 is arranged so as to be located at the center of the cylinder 18, and the coil springs 19 attached to the piston 21 have the same spring constants on both sides of the piston 21. A pair of coil springs 19c and 19d, each of which is provided with a clearance portion 32 having a required interval between the coil springs 19c and 19d and a cushioning material 29 provided inside the end plates 23 and 24 on both sides. .. The gap portion 32 is appropriately determined by the elastic deformation ability of the laminated rubber of the seismic isolation device 7, but it is preferably 70 to 80% of the limit deformation allowable value of the seismic isolation device 7.

In short, the horizontal deformation of a seismic isolation building due to an earthquake is usually small during a small or medium-sized earthquake, so when the coil spring 19 (19c, 19d) is not in contact with the cushioning material 29, the vibration isolation The seismic isolation building after the earthquake can be restored to its original state by the elastic restoring force of the device 7 itself, but for horizontal deformation during a large earthquake, the free space 32 is eliminated and the coil spring 19 is used as a cushioning material 29. With respect to the horizontal deformation that abuts and compresses, the deformation of the seismic isolation building is restored to the length of the clearance portion 32 after the earthquake by the elastic reaction force due to the compression of the coil spring 19, and then the elastic restoration of the seismic isolation device 7. It is restored by ability, and the seismic isolation building after the earthquake is restored to its original state by dividing the roles of each.
The cushioning material 29 is provided so as to be elastically and smoothly compressed until the spring 19 is brought into close contact with the cushioning material 29, and is the same as the conventional cushioning material. Further, it may be rubber, a spring or the like.
Further, the buckling prevention member 20 may be fixed by a screw type as shown in FIG. 5, but may be tightened and fixed by a nut 28 via a washer 27 as shown in FIG.
The limit deformation allowable value of the seismic isolation device in the present invention is the maximum horizontal deformation amount of the seismic isolation device 7 within the elastic range. Therefore, even after a huge earthquake occurs, the seismic isolation device shall retain the ability to restore.

The relative displacement between the foundation structure 1 and the superstructure 2 when the spring-type vibration damping damper 11 according to the above embodiment receives an earthquake will be described with reference to FIGS. 7A, 7B, and 7C.
First, the figure (a) shows a state in which the relative displacement is deformed in the direction indicated by the arrow a (the direction in which the relative distance increases) and reaches a predetermined value, and the figure (b) shows the coil springs 19c and 19d in the installed state. The non-acting (no relative displacement) state is shown, and the figure (c) shows the state in which the relative displacement is deformed in the direction indicated by the arrow b (the direction in which the relative distance is shortened) and reaches a predetermined value.
For example, in a seismic isolation structure, a seismic isolation device 7 is installed for a seismic force normally assumed, and if it is within the assumption, it returns to the original state due to elastic deformation of the laminated rubber in the seismic isolation device 7. In the case of a large earthquake that exceeds expectations, the laminated rubber is excessively deformed and the seismic isolation device 7 is destroyed.

In either case, by attaching a pair of coil springs 19c and 19d having the same spring constant to both sides of the piston 21, the relative displacement between the foundation structure 1 and the upper structure 2 may extend or contract beyond the clearance portion 32. The elastic reaction force of any of the coil springs 19c and 19d absorbs the seismic energy and restores the relative displacement between the foundation structure 1 and the superstructure 2. Therefore, the stroke L of the relative displacement between the foundation structure 1 and the upper structure 2 is a stroke in which the piston 21 is (displaced) toward any of the end plates 23 and 24 from the intermediate position in the clearance portion 32 in the cylinder 18. However, since the initial restoring force of both coil springs 19c and 19d acts strongly, not only can the function of the seismic isolation device 7 be prevented from deteriorating due to the fatigue load, but also the buckling prevention material 20 is arranged, so that the coil springs 19c , 19d can always and smoothly repeatedly expand and contract in the cylinder 18 without buckling. The end plates 23 and 24 of the cylinder 18 exert a stopper function against an excessive relative displacement.

Further, as the coil springs 19c and 19d to be used, those obtained by synthesizing a plurality of coil springs having different panel coefficients in a series can be used, and for example, those formed by changing the diameter, the number of turns and the material of the spring wire rod. It can be used, and in any case, as shown in FIG. 8, the characteristics of the coil spring become curved (non-linear elastic characteristics), the initial spring reaction force is reduced, and the basic structure 1 and the superstructure 2 The relative movement of the is not strongly restrained.

The spring-type seismic isolation damper 11 according to the present invention is a damper used for a seismic isolation building structure in which a seismic isolation device 7 is interposed between a superstructure 2 and a foundation structure 1, and the damper 11 is , A cylinder 18 provided with end plates 23 and 24 at both ends, a rod 22 slidably arranged in the cylinder 18 and having a piston 21 attached to one end, and a pair provided on both sides of the piston 21. The coil springs 19c and 19d are composed of an elastic cushioning material 29 installed inside both end plates 23 and 24, respectively. One end of the coil springs 19c and 19d is fixed to the piston 21, and the other end and the elastic cushioning material are fixed. When the clearance portion 32 is provided between the gap portion 32 and the relative displacement between the upper structure 2 and the foundation structure 1 exceeds the clearance portion 32, seismic energy is generated by the elastic reaction force generated by the compression of the coil springs 19c and 19d. Since the configuration has a function of absorbing, a stopper function of preventing excessive deformation of the seismic isolation device 7, and a function of restoring the deformation of the seismic isolated building after the earthquake, the relative displacement between the superstructure 2 and the foundation structure 1 is provided. It is possible to reduce not only the cost of the device itself but also the labor of work by making it possible to work in both directions without the need to arrange a device that is effective for expansion or contraction as in the prior art. Further, without the need to install both a stopper and a damper, the cylinder 18 is provided with a stopper function (both side plates) for preventing excessive deformation of the laminated rubber seismic isolation device 7, and has three functions of deformation restoration function and seismic energy absorption function. It was made into a seismic isolation damper with. Then, the reaction force (restoring force) due to the compression of the coil springs 19c and 19d suppresses the deformation of the laminated rubber seismic isolation device 7, and also includes the deformation generated by the horizontal force such as a small and medium-sized earthquake or a strong wind. Even if the laminated rubber seismic isolation device 7 receives repeated horizontal force, most of the deformation is restored by the deformation restoration function of the coil springs 19c and 19d, and the laminated rubber due to the fatigue load is restored. Since the deterioration of the seismic isolation device 7 can be prevented and the service life of the seismic isolation device 7 can be extended, it can be used in a wide range in this type of seismic isolation structure.

1 Foundation structure 2 Superstructure 3 Ground 4 Foundation pile
5 Wrapple foundation 6 Matte slab 7 Laminated rubber seismic isolation device 8 Footing 9 Large beam (underground beam)
10 Pillar 11 Spring type vibration control damper 12 Support base 13 Support base 14, 15 Mounting base 16, 17 Connecting pin 18 Cylinder 19, 19c, 19d Coil spring 20 Buckling prevention material 21 Piston 22 Rod (piston rod)
23, 24 End plate 25 holes or screw holes 26 Insertion holes 27 Washers 28 Nuts 29 Cushioning material 30 Space part 31 Insertion holes 32 Free space a, b Arrows

Claims (4)

A damper used for a seismic isolation building structure in which a seismic isolation device is interposed between the superstructure and the foundation structure.
The damper includes a cylinder having end plates at both ends, a rod slidably arranged in the cylinder and a piston attached to one end, a pair of springs provided on both sides of the piston, and both ends. It consists of elastic cushioning materials installed inside the board.
One end of the spring is fixed to the piston, and a clearance portion is provided between the other end and the elastic cushioning material.
When the relative displacement between the superstructure and the foundation structure exceeds the clearance portion, a function of absorbing seismic energy by the elastic reaction force generated by the compression of the spring, a stopper function of preventing excessive deformation of the seismic isolation device, and a stopper function. A spring-type seismic damping damper characterized by having a function to restore the deformation of the seismic isolated building after an earthquake. The clearance portion is set to 70 to 80% of the limit deformation allowable value of the seismic isolation device, and the spring is brought into close contact immediately before the relative displacement reaches the limit deformation allowable value of the seismic isolation device. The spring-type seismic isolation damper according to claim 1. The spring-type vibration damping damper according to claim 1 or 2, wherein the spring is a coil spring, and a plurality of buckling prevention materials are installed inside the spring with a required gap over the entire length of the cylinder. The spring-type vibration damping damper according to claim 1, wherein the spring is a combination of at least two different spring coefficients in a series in the length direction.

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