JPH06105015B2 - Vibration isolation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a vibration isolator, and in particular, it can protect an entire building structure from large vibrations such as a large earthquake, and also small and medium vibrations such as small and medium earthquakes. Also, the present invention relates to a vibration isolation device that is excellent in vibration damping performance against microvibrations from the outside during normal times.

<< Prior Art >> Conventionally, the applicant of the present invention first disclosed the vibration isolation device of this type.
There is one proposed in 61-151377.

The proposed vibration isolator comprises an elastic body formed by laminating a rubber plate and a steel plate between a building structure and its foundation, and one end fixed to the foundation and the other end loosely fitted to the upper building structure. A main damper made of the steel rod is provided, and a cushioning material such as rubber is further provided in the loose fitting portion.

According to this vibration isolator, the vertical load of the building structure is supported by the foundation through the elastic body, and the small and medium vibrations in the horizontal direction at the time of a small or medium earthquake or normal vibration are generated by the elastic body and the cushioning material. It is designed to be absorbed and attenuated by. Also, when the horizontal displacement exceeds a prescribed value due to a large earthquake, the steel rod of the main damper engages with the foundation and the building structure, and the elastic and plastic deformation of the steel rod causes vibration energy. By absorbing a large amount of, the skid of the building structure can be suppressed as much as possible and the entire structure can be protected.

<< Problems to be Solved by the Invention >> However, as a result of various experiments thereafter, the present applicant has found that there is room for improvement in the above-mentioned conventional one.

That is, in the above-mentioned conventional one, a cushioning material is packed in the loose fitting portion between the main damper and the building structure, and the cushioning material is used to absorb vibration energy during a small-to-medium earthquake and microvibration due to traveling of a vehicle or the like in a normal time However, since the cushioning material is annularly packed in the loosely fitting part between the main damper and the building structure, the cushioning material is restricted in terms of space and area of the cushioning material. However, it was not possible to provide sufficient energy absorption capacity.

The present invention has been made in view of the above circumstances, and an object thereof is to effectively suppress small and medium vibrations during small and medium earthquakes and minute vibrations from the outside during normal times.
Moreover, it is to provide a vibration isolation device capable of protecting the entire building structure from a large vibration in the event of a large earthquake.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention supports a vertical load of the building structure between a building structure and a foundation and elastically deforms with respect to a horizontal load. And an elastic body that allows relative displacement in the horizontal direction between the building structure and the foundation, and when the relative displacement amount with respect to the horizontal load exceeds a predetermined value during a large earthquake, etc. A main damper that engages with and absorbs the horizontal vibration energy,
In a vibration isolator including a sub-damper that absorbs horizontal vibration energy by bending deformation and shearing of the viscoelastic body when the relative displacement amount is equal to or less than the predetermined value, the sub-damper is the viscoelastic body. It is characterized by having a pressing means for compressing in the direction of gravity so as to intervene between the foundation and the building structure.

<< Operation >> According to the present invention having the above-described configuration, the vibration energy of the microvibration transmitted to the foundation during normal driving of the vehicle and the small and medium-sized vibrations such as the small and medium-sized earthquake are generated by the vibration energy of the viscoelastic body of the sub-damper. The amount of energy that is absorbed by the bending deformation and transmitted to the building structure is attenuated and buffered, so that the shaking of the building structure is suppressed as much as possible. At this time, since the viscoelastic body is interposed between the foundation and the building structure via the pressurizing means, there is no strict restriction on the installation space with respect to the usage amount and the area functioning as a buffer, Using a sufficient amount of viscoelastic body and having a large shearing area, it is possible to absorb vibration energy of small vibration to small vibration as much as possible.

<< Example >> A preferred example of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the vibration isolation device according to the present invention, and FIG.
The figure shows the arrangement position.

As shown in the figure, the vibration isolator 2 is interposed between the building structure 4 and the foundation 6 and arranged at the four corners of the building structure 4, respectively.

Each of the vibration isolation devices 2 supports the vertical load of the building structure 4 and is displaced in the horizontal direction by the horizontal load to move the building structure 4 vertically.
And the elastic body 8 which allows relative displacement between the base 6 and the base 6, and when the relative displacement in the horizontal direction exceeds a predetermined value, the base 6 and the building structure 4 are engaged with each other to absorb horizontal vibration energy. The main damper 10 and the horizontal vibration energy when the relative displacement is less than or equal to a predetermined value is viscoelastic body (a material having both viscous resistance and elastic properties, for example, resin, or resin mixed with ferrite Such as) 12 and a sub-damper 14 that absorbs by shearing and bending deformation.

The elastic body 8 is obtained by alternately laminating flat rubber plates 16 and steel plates 18 having the same shape, and attaching end plates 20 to the upper and lower ends thereof. It has load bearing capacity to support the load by sharing it, and also has the function of displacing with respect to horizontal load and absorbing mainly horizontal vibrations such as during an earthquake.

On the other hand, the main damper 10 includes a steel rod 22 having a circular cross section and a pair of upper and lower mounting plates 24a and 24b arranged at the upper and lower ends of the steel rod 22, and the upper mounting plate 24a is on the side of the building structure 4 side. The lower mounting plate 24b is fixed to the base so as to close the recess 26a provided in the base 4, and the lower mounting plate 24b is fixed to the base so as to close the recess 26b provided in the base.

The lower end of the steel rod 10 penetrates the lower mounting plate 24b and is welded and fixed to the lower surface thereof, and the upper end thereof is loosely fitted into an insertion hole 28 opened in the upper mounting plate 24a, and the loose fitting portion has a predetermined shape. Clearance s (about 2 mm) is opened. That is, when the relative horizontal displacement between the foundation 6 and the building structure 4 becomes equal to or more than the clearance s, the steel rod 22 engages with the building structure 4 and the foundation 6, and the horizontal vibration energy is applied to the steel rod 22. It is designed to be largely absorbed by elastic deformation or plastic deformation.

On the other hand, the sub-damper 14 is a viscoelastic body 12 molded into a solid columnar shape, an iron plate upper plate 30a and lower plate 30b provided on the upper and lower ends of the viscoelastic body 12, and a lower plate 30b. A sliding plate 32 made of an iron plate, which is interposed between the base 6 and the base 6 and is laid and fixed on the side of the base 6, and is interposed between the upper plate 30a and the building structure 4 to gravity the viscoelastic body 12. It mainly comprises a pressurizing means 34 for pressurizing in the direction.

In the present embodiment, the pressing means 34 has a pipe-shaped female screw member 36 having an upper end fixed to the building structure 4 side, and a lower end screwed into the female screw member 36 so that the lower end is the upper plate 30a. A screw jack-like thing consisting of a pipe-shaped male screw member 38 welded and fixed to the central part of the is used, and the pressing force can be arbitrarily adjusted by rotating the male screw member 38 side. ing.

Further, the viscoelastic body 12 and the upper and lower plates 30a and 30b of the upper and lower ends thereof.
Is fixed by vulcanization adhesion or the like, and while the lower plate 30b is pressed against the sliding plate 32 by the pressing force of the pressing means 34, the shearing force acting on the viscoelastic body 12 by the horizontal load is applied. When the frictional force acting between the lower plate 30b and the sliding plate 32 is exceeded according to the applied pressure, the sliding plate 32 slides in the horizontal direction.

The viscoelastic body 12 is molded into a solid columnar shape having a height of about 5 cm to 10 cm and a diameter of several cm to several tens of cm depending on the allowable elongation of the material. At this time, when the allowable elongation of the viscoelastic body 12 is large, the diameter is molded into several tens of cm and used as one lump, and when the allowable elongation is small, the diameter is molded into several cm. Then, a plurality of those having a small diameter are used, and the deformation capacity as a whole is enhanced by the shearing and bending deformation of each individual cylindrical shape.

Therefore, in the vibration isolator 2 configured as described above, the vibration energy of the microvibration transmitted to the foundation 6 due to the traveling of the vehicle during normal operation has a vibration energy of the viscoelastic body 12 of the sub damper 14.
Absorbed by the shearing and bending deformation of the building structure 4
The amount of energy transmitted to the building is attenuated and buffered, so that the shaking of the building structure 4 is suppressed as much as possible.

Further, during a small-to-medium-scale earthquake, the small-to-medium vibrations are further absorbed and buffered by the elastic deformation of the elastic body 8.

On the other hand, during a large earthquake in which the relative horizontal displacement between the foundation 6 and the building structure 4 exceeds a predetermined value (clearance S), the steel rod 22 of the main damper 10 engages with the building structure 4 and the foundation 6 mutually. The elastic deformation and the plastic deformation of the steel rod 22 largely absorb the vibration energy to protect the entire building structure 4 from skidding.

At this time, since the viscoelastic body 12 is interposed between the foundation 6 and the building structure 4 by compressing it in the direction of gravity through the pressurizing means 34, the lower plate 30b and the sliding plate depending on the applied pressure. When the shearing force acting on the viscoelastic body 12 by the horizontal load exceeds the frictional force acting on the lower plate 32, the lower plate 30b slides on the sliding plate 32. Therefore, at this time, the damping performance of the viscoelastic body 12 itself deteriorates, but in this case, the vibration energy is converted into friction heat during sliding and is largely absorbed, and the pressurizing means 34 is used at the start of sliding at that time. It can be adjusted arbitrarily with the set pressure of.

Further, since the viscoelastic body 12 is interposed between the foundation 6 and the building structure 4 through the pressurizing means 34, the usage amount and the area functioning for buffering the viscoelastic body 12 are severe in the conventional space. There is no restriction, and it becomes possible to absorb the vibration energy of the small vibration to the small vibration as much as possible by using a sufficient amount of viscoelastic body and with a large shearing area. Also in this case, the shear cross-sectional area of the viscoelastic body may be about 400 to 500 cm ² for a building structure having a building weight of 2000 to 3000 tons, and there is no particular problem in the installation space of the sub damper 14.

In this embodiment, the pressing means 34 is made like a screw jack so as to apply pressure with a screw force. Therefore, rattling is unlikely to occur, and it may be retrofitted after the completion of the vibration-isolated building if necessary. Is also easy. In addition, as a result of an experiment in which the vibration isolator of this embodiment was attached to a 20 ton class vibration isolation frame, it was found that the damping constant h = 10 to 15% for the displacement range from the micron order to about 2 cm. Performance has been confirmed, and it has been confirmed that the amount of vibration decreases even during actual normal microvibration and earthquake observations.

In the above embodiment of the present invention, the sliding plate 32 of the sub damper 14 is
Is installed between the base 6 and the lower plate 30b, but separately, the lower plate is fixed on the base 6, and the slide plate is installed between the upper plate 30a and the male screw member 38. When the shearing force acting on the viscoelastic body 12 due to the horizontal load exceeds the frictional force acting between the upper plate and the sliding plate, the upper plate 30a is provided to prevent harmful deformation of the viscoelastic body. The lower surface of the sliding plate may be slid horizontally.

As described above, in the above embodiment, the viscoelastic body of the sub damper 14 is used.
When a large shearing force is applied to 12, the lower plate 30b and the upper plate 30a of the sub-damper 14 slide on the sliding plate to prevent harmful deformation of the viscoelastic body 12. The structure shown in FIG. 3 is conceivable. That is, a circular notch having a required diameter is provided at the center position of the lower plate 30b 'of the sub-damper 14 and fixed on the foundation 6, while the upper plate 30a' is sized so as to straddle the entire lower plate 30b '. A tubular viscoelastic body 12 is provided between 30b 'and the upper plate 30a'. Further, a stopper piece 40 is vertically provided on the lower surface of the upper plate 30a 'so as to be located at the center of the lower plate 30b'. The upper surface of the upper plate 30a 'is used as a sliding surface, a slidable plate 39a "is loaded on the upper surface, and the upper surface of the plate 30a" has a pipe-shaped male screw as in FIG. The pressure force adjusted by the member 38 is applied. Although not shown, the elastic body such as laminated rubber and the main damper are provided in the same manner as in FIG.

With the above configuration, the viscoelastic body 12 of the sub damper 14
If a shearing force above the specified value is applied to the stopper piece 40
Can contact the inner peripheral end surface of the circular notch of the lower plate 30b 'to prevent harmful deformation of the viscoelastic body 12, and if a shearing force exceeding this is applied, the upper plate 30a' will be Plate 30
The a ″ slides horizontally.

In each of the above-described embodiments, the sliding plate 32 (or the sliding plate 32 that slides when a shearing force of a predetermined value or more is applied to the viscoelastic body 12 to prevent harmful deformation of the viscoelastic body 12). Although the plate body 30 ″) is provided, the foundation 6 and the building structure 4 are in a state where the viscoelastic body 12 is compressed by the pressure means 34.
Just by interposing between the
Using a sufficient amount of viscoelastic body and capable of absorbing vibration energy of small vibrations or small and medium vibrations as much as possible with a large shear cross-sectional area, a desired effect can be obtained. <Effect> According to this, since the viscoelastic body of the sub-damper is interposed between the foundation and the building structure while being compressed in the gravity direction by the pressing means, there is no strict restriction on the installation space of the viscoelastic body, and there is a sufficient amount. The viscoelastic body can be used and the shearing area can be increased to increase the amount of energy absorbed by the viscoelastic body. As a result,
It is possible to improve the vibration damping performance for small vibrations due to running of the vehicle during normal times and small and medium-sized vibrations such as small- and medium-sized earthquakes.

[Brief description of drawings]

FIG. 1 is a side view showing a preferred embodiment of a vibration isolator according to the present invention, FIG. 2 is a plan view showing an example of the arrangement position of each vibration isolator, and FIG. 3 is a vibration isolator of the present invention. It is sectional drawing which shows the sub-damper structure part which concerns on the other Example in an apparatus. 2 ... Vibration isolation device, 4 ... Building structure 6 ... Foundation, 8 ... Elastic body 10 ... Main damper, 12 ... Viscoelastic body 14 ... Sub-damper, 34 ... Pressurizing means

Claims (1)

[Claims] 1. A vertical load of the building structure is supported between the building structure and the foundation and elastically deformed with respect to a horizontal load to allow relative displacement in the horizontal direction between the building structure and the foundation. An elastic body, and a main damper that mutually engages with the building structure and the foundation when the relative displacement amount with respect to the horizontal load exceeds a predetermined value in the event of a large earthquake and absorbs the horizontal vibration energy. In the vibration isolator including the sub-damper that absorbs the horizontal vibration energy by bending deformation and shear of the viscoelastic body when the relative displacement amount is equal to or less than the predetermined value, the sub-damper has the viscoelasticity. A vibration isolator comprising a pressurizing means for compressing a body in the direction of gravity so as to be interposed between a foundation and a building structure.