JP2002181124A - Friction damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction damper capable of securing reduction of response acceleration of superstructure by displaying a function by moderating restraint against an isolator at the time of initial rising at the time when an earthquake takes place. SOLUTION: The friction damper includes a friction generating device 5 to be set on a substructure 3 and a spindle 6 to be set on the superstructure 2, the friction generating device 5 is furnished with a holding frame 9, a plural number of presser plates 20 held on the holding frame 9, laminated and arranged, at least one sliding plate 21 arranged free to slide between the presser plates 20 adjacent to each other and an end part of which is connected to the spindle 6 free to rotate in the horizontal direction and a load giving means 28 built in the holding frame 9 and to give a load in the thickness direction along the whole of the presser plates 20 and the sliding plate 21, and a rubber shoe 50 is interposed between the holding frame 9 and the lower part structure 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction damper, and more particularly, to a friction damper for attenuating a relative motion generated by an earthquake or the like between an upper structure and a lower structure.

[0002]

2. Description of the Related Art In recent years, many seismic isolation structures have been adopted for buildings in preparation for the occurrence of a large-scale earthquake. This seismic isolation structure generally includes an isolator (seismic isolation bearing) made of laminated rubber and the like that transmits vibration to the building by prolonging the vibration caused by the earthquake between the building and the foundation, and absorbs vibration energy to generate vibration. This is achieved by arranging a damper for attenuating the pressure.

As one of such dampers, there is known a friction damper described in Japanese Patent Application Laid-Open No. 2000-234648 proposed by the present applicant. The friction damper includes a friction generator installed on a foundation and a main shaft (connection shaft) installed on a building. Then, the friction generating device presses the holding frame, the plurality of pressing plates stacked on the holding frame, the sliding plates disposed between the pressing plates, and the pressing plates and the sliding plates in the thickness direction. A slide plate is rotatably connected to the main shaft.

[0004] According to such a proposed friction damper, the degree of freedom of design is large, and it is possible to change various elements or factors that cause friction, and as a result, a large damping force can be obtained with one device. There is an advantage.

[0005] Incidentally, the above-mentioned friction damper counteracts the horizontal force caused by the earthquake by a static friction force generated at first between the sliding plate and the holding plate. Then, when the static friction force reaches a certain level, the friction is suddenly cut and the sliding plate slides, and the dynamic energy generated at that time absorbs vibration energy. In other words, the friction damper has a large rising rigidity (elastic rigidity) in the friction history showing the load-deformation relationship, and therefore has a large restraining force on the isolator at the time of rising, the isolator does not perform its function, and the building is not subjected to the earthquake acceleration. Response acceleration is not reduced.

[0006]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above technical background, and has the following objects. SUMMARY OF THE INVENTION An object of the present invention is to provide a friction damper capable of exhibiting its function by relaxing a binding force on an isolator at the time of rising at the beginning of an earthquake, thereby ensuring a reduction in a response acceleration of an upper structure. .

[0007]

The present invention employs the following means to achieve the above object. That is, the present invention is a friction damper for attenuating a relative motion generated between an upper structure and a lower structure by a frictional force, and a friction generator installed in the lower structure,
A main shaft installed on the upper structure, wherein the friction generating device includes a holding frame, a plurality of holding plates held by the holding frame and arranged in a stacked manner, and between the holding plates adjacent to each other. At least one sliding plate slidably disposed, the end of which is rotatably connected to the main shaft in a horizontal direction; and at least one sliding plate incorporated in the holding frame and extending over the holding plate and the sliding plate. Load applying means for applying a load in the thickness direction of the friction damper, wherein a rubber shoe is interposed between the holding frame and the lower structure.

When a relative movement occurs between the upper structure and the lower structure due to an earthquake or the like, the sliding plate of the friction generator rotates with respect to the main shaft following the movement and moves between the sliding plate and the holding plate. Causes slippage. Kinetic energy is
The friction generated when the sliding plate slides is absorbed and attenuated. In such a friction damper,
At the beginning of the earthquake, the rubber shoe interposed between the holding frame and the lower structure undergoes horizontal shear deformation. Therefore,
Friction dampers reduce the binding force on the isolator,
The isolator performs the seismic isolation function, reducing the seismic response acceleration.

More specifically, the holding frame includes a cylindrical body having flanges at upper and lower portions and having an opening at a peripheral wall, and the main shaft is installed so as to extend inward of the cylindrical body. The holding plate and the sliding plate are disposed between the upper and lower flanges, the sliding plate extends inward of the cylindrical body through the opening,
Its end is connected to the main shaft.

A sleeve slidable in the vertical direction is fitted on the outer periphery of the main shaft, and an end of the slide plate is connected to the sleeve so as to be rotatable in the horizontal direction.
A plurality of plate groups including the holding plate and the sliding plate are arranged at equal angular intervals between the upper and lower flanges.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an application example of a friction damper according to the present invention. A friction damper 1 is installed between a building 2 as an upper structure and a foundation 3 as a lower structure in combination with an isolator 4 and adjacent thereto. You.
The isolator 4 is a seismic isolation bearing made of laminated rubber that is sheared and deformed in the horizontal direction, and is well known.

FIG. 2 is a vertical sectional view showing the whole of the friction damper 1, FIG. 3 is a sectional view taken along line AA of FIG. 2, and FIG. 4 is a sectional view taken along line BB of FIG. is there. The friction damper 1 includes a friction generator 5 installed on a foundation 3 and a main shaft 6 installed on a building 2. The friction generating device 5 includes a holding frame 9.
Is a cylindrical body 12 having flanges 10 and 11 at upper and lower portions,
It comprises a lower plate 13 to which the cylindrical body 12 is fixed. The lower flange 11 is defined by an outer peripheral portion of the lower plate 13.

Between the lower plate 13 and the base plate 7, a plurality of rubber shoes 50 (in this embodiment, the arrangement is shown in FIG. 5) are interposed, and the base plate 7 is fixed to the base 3. Rubber shoes 50 are upper and lower steel plates 51, 52
And a rubber layer 53 bonded and vulcanized therebetween.
The upper and lower steel plates 51 and 52 are connected to the lower plate 13 and the base plate 7 of the holding frame 9 via mounting bolts 54 and 55.
Respectively.

The main shaft 6 is arranged so that its lower part extends inward of the cylindrical body 12, and an annular plate 15 is fitted on its upper part. This annular plate 15 is fixed to the building 2 via the base plate 8.

Upper and lower flanges 10, 1 of the holding frame 9
A plurality of holding plates 20 are stacked and arranged between the two. A sliding plate 21 is slidably disposed between the holding plates 20 adjacent to each other so as to intersect with the holding plate 20. An opening 22 is formed in the peripheral wall of the cylindrical body 12, and one end of each sliding plate 21 extends through the opening 22 to the inside of the cylindrical body 12 and is connected to the main shaft 6. Each sliding plate 21
Are connected to each other by a connecting rod 24.

Pressing plate 20 and sliding plate 21
Are made of a material that can provide the required frictional force while improving their slip. That is, the holding plate 20 is made by fixing a sliding member 23 made of, for example, a tetrafluoroethylene plate or the like to the surface of a steel plate, and the sliding plate 21 is made of a stainless steel plate. In addition, if at least one sliding plate 21 is used, a frictional force is generated, but by providing a plurality of the sliding plates 21, the damping force can be easily adjusted.

Both ends of each holding plate 20 are connected to a pair of pressure bolts 2 provided between upper and lower flanges 10 and 11.
They are interconnected by 5, 25. The heads 25 a of these pressure bolts 25 are fitted into holes 31 provided in the upper flange 10. A nut 27 is attached to the lower end of the pressure bolt 25 through the lower flange 11. A disc spring 28 and a washer 29 are mounted on the outer periphery of the pressure bolt 25 between the head 25 a and the uppermost holding plate 20. The disc spring 28 is compressed by tightening the nut 27, whereby a load is applied to the entire holding plate 20 and the sliding plate 21.

Lower part 3 of main shaft 6 extending inward of cylindrical body 12
2 has a rectangular cross section as shown in FIG. 3, and a rectangular tube sleeve 33 is fitted to the lower portion 32. The rectangular sleeve 33 cannot rotate in the horizontal direction with respect to the main shaft 6, but can slide in the vertical direction. Square sleeve 3
A plurality of annular plates 34 are fixed to the outer periphery of the main body 3 at intervals in the vertical direction. The end of each sliding plate 21 extends between the annular plates 34, 34, each annular plate 34 and each sliding plate 21 having a pin 3 extending therethrough.
5 are connected to each other. Thereby, the sliding plate 21 is rotatable in the horizontal direction with respect to the annular plate 34, that is, the main shaft 6. Further, since the rectangular cylinder sleeve 33 to which the annular plate 34 is fixed is slidable with respect to the main shaft 6, the sliding plate 21 is movable in the vertical direction with respect to the main shaft 6.

A plurality of plate groups 40 each including the above-described holding plate 20 and sliding plate 21 are arranged at equal angular intervals on the outer periphery of the cylindrical body 42. The sliding plate 21 of each plate group 40 is connected to the annular plate 34 in the manner described above.

Next, the operation of the friction damper will be described with reference to FIG. Earthquake etc. occurred, building 2 and foundation 3
When a relative movement in the direction of the arrow in FIG. 5 occurs between the sliding shafts 21 of the plate groups 40,
, And slips with the holding plate 20. The kinetic energy is mainly absorbed and attenuated by the friction generated when the sliding plate 20 slides. The magnitude of the damping force can be arbitrarily set by changing the number of the plate groups 40, the number of overlapping and the sizes of the disc springs 28, the size, or the number of the sliding plates 21, and the like.

According to the friction damper, the rubber shoe 50 is interposed between the holding frame 9 and the base plate 7. Therefore, at the beginning of the earthquake, the rubber shoe 50 is sheared and deformed in the horizontal direction. Therefore, the friction damper relaxes the restraining force on the isolator 4 shown in FIG. 1, and the isolator 4 exerts the seismic isolation function, and the earthquake response acceleration is reduced. According to the result of the analysis, if the rising rigidity of the friction damper becomes about 20 times the rigidity of the laminated rubber constituting the isolator 4, the response acceleration becomes 1
A reduction of about 00 gal was observed, and it was found that the reduction was approximately equal to a hysteretic damper such as a well-known lead damper or steel rod damper.

A sliding plate 21 connecting the friction generator 5 and the main shaft 6 is movable in a direction perpendicular to the main shaft 6. Therefore, when the isolator 4 is bent vertically, the sliding plate 21 and the main shaft 6 relatively move in the vertical direction, and follow the deflection of the isolator 4. Thereby, the friction generator 5 operates smoothly at all times, and the operation state can be maintained for a long time.

In the above description, the case where the friction damper according to the present invention is applied to a seismic isolation system for a building has been described as an example. It can be applied to other systems. Further, the present invention relates to Japanese Patent Application Laid-Open No. 2000-234.
No. 648 is also applicable to the embodiment shown in FIGS.

[0024]

As described above, according to the present invention, at the beginning of the earthquake, the rubber shoe interposed between the holding frame and the lower structure undergoes horizontal shear deformation, so that the friction damper exerts a restraining force on the isolator. The seismic isolation function is exerted by the isolator, and a reduction in seismic response acceleration can be ensured.

[Brief description of the drawings]

FIG. 1 is a diagram showing an application example of a friction damper according to the present invention.

FIG. 2 is a vertical sectional view showing the entire friction damper.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line BB of FIG. 3;

FIG. 5 is a plan view showing an arrangement state of a rubber shoe.

FIG. 6 is an operation explanatory view of the friction damper according to the present invention.

[Explanation of symbols]

 1: Friction damper 2: Building 3: Foundation 4: Isolator 5: Friction generator 6: Main shaft 7: Base plate 8: Base plate 9: Holding frame 10: Upper flange 11: Lower flange 12: Cylindrical body 20: Holding plate 21: Sliding plate 22: Opening 23: Sliding material 25: Pressure bolt 28: Disc spring 29: Washer 32: Lower main shaft 33: Square tube sleeve 34: Annular plate 35: Pin 40: Plate group 50: Rubber shoe 51: Upper steel plate 52: Lower steel plate 53: Rubber layer

Claims (4)

[Claims] 1. A friction damper for attenuating relative motion generated between an upper structure and a lower structure by a frictional force, comprising: a friction generator installed in the lower structure; and a friction generator installed in the upper structure. A friction generating device, wherein the friction generator is held by the holding frame, a plurality of holding plates held and stacked, and slidably arranged between the holding plates adjacent to each other, At least one sliding plate having an end portion rotatably connected to the main shaft in a horizontal direction; and a load incorporated in the holding frame and extending in a thickness direction of the pressing plate and the sliding plate over the entirety thereof. A friction damper comprising: a load applying means for applying a force; and a rubber shoe interposed between the holding frame and the lower structure. 2. The holding frame includes a cylindrical body having a flange at upper and lower portions and having an opening at a peripheral wall, wherein the main shaft is installed so as to extend inward of the cylindrical body, and A plate and the sliding plate are disposed between the upper and lower flanges, the sliding plate extends inward of the cylinder through the opening, and an end of the sliding plate is connected to the main shaft. The friction damper according to claim 1, wherein 3. A sleeve is fitted around the outer periphery of the main shaft so as to be slidable in a vertical direction, and an end of the slide plate is connected to the sleeve so as to be rotatable in a horizontal direction. Item 3. A friction damper according to Item 2. 4. A friction damper according to claim 2, wherein a plurality of plate groups comprising said holding plate and said sliding plate are arranged at equal angular intervals between said upper and lower flanges.