JP2002115418A - Friction dampers for seismic devices - Google Patents

Abstract

(57) [Problem] To provide a frictional damper provided on a conventional anti-seismic, vibration-damping brace fixed diagonally to a building, the same tensile force and compressive force are imposed. However, the seismic design that takes into account the problem requires a large cross-sectional area of the friction damper, the seismic resistance, and the vibration control brace, which has the disadvantage of increasing the cost. SOLUTION: In the friction damper of the present invention, an upper member and a lower member fixed respectively at two points which are relatively displaced are slidably overlapped via a friction surface, and the overlapped portions are respectively connected to the base end side. The inclined surfaces which are parallel to each other are formed, and between the inclined surfaces on both sides is pressed by a shaft member extending vertically to the inclined surfaces. The shaft member includes a bolt and a nut, and an elastic body is interposed between the nut and the inclined surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction damper for an anti-seismic device, in particular, an anti-seismic and vibration-damping brace in a building
The present invention relates to a friction damper for an anti-seismic device which is incorporated in an apparatus such as a friction damper.

[0002]

2. Description of the Related Art In FIG. 15, reference numeral 1 denotes a building, 2 denotes a so-called friction damper utilizing sliding and friction, and 3 denotes an anti-seismic and vibration-damping brace with a friction damper 2 interposed therebetween. In order to absorb the energy of the wind and the earthquake acting on the building 1, the above-mentioned earthquake-resistant and vibration-damping brace 3 is interposed between two portions located on the diagonal line of the building 1.

FIG. 16 shows details of the above-mentioned conventional friction damper 2. Reference numeral 4 denotes an upper plate whose base end is fixed to the lower end of an upper brace portion 3a of the seismic and vibration damping brace 3, and 5 denotes its base end. The lower plate 6 is fixed to the upper end of the lower brace portion 3b of the seismic and vibration damping brace 3 and its free end is superimposed on the free end of the upper plate 4, and 6 is provided on the upper plate 4. An elongated hole for inserting a bolt extending in the axial direction of the vibration brace 3, a bolt through hole 7 provided in the lower plate 5, and a bolt through hole 7
And 9 are nuts screwed into the tightening bolts 8, and 9 are nuts screwed into the tightening bolts 8.
Thus, the upper plate 4 and the lower plate 5 are slidably connected to each other.

[0004] When the building 1 shakes due to wind or an earthquake and a tension or a compressive force is generated in the earthquake-resistant and vibration-damping brace 3, the conventional friction damper 2 against the tightening force of the bolt 8 and the nut 9 is prevented. The lower plate 5 slides relative to the upper plate 4,
Due to the friction caused by the slip, the energy of the wind or the earthquake is absorbed.

[0005]

A tension or compression force acts on the conventional friction damper 2 to lower the lower plate 5 of the friction damper.
Slides relatively to the upper plate 4, the friction damper 2
The tension Pt and the compressive force (buckling load) Pc which are borne by, are as follows: If the tightening force of the bolt and the nut is N, and the friction coefficient between the upper plate 4 and the lower plate 5 is μ, the tension Pt = μN and the compression force, respectively. Force P
c = μN, and all have the same size.

However, in designing the seismic strength of a normal brace, the compressive force is considered rather than the tension, and the cross section of the brace is determined by the compressive force Pc. Therefore, it is necessary to increase the cross-sectional area of the upper plate, the lower plate, the brace, and the like in order to increase the seismic capacity, and there is a disadvantage that the cost is increased.

The present invention has been made to eliminate the above-mentioned disadvantages.

[0008]

SUMMARY OF THE INVENTION A friction damper for an anti-seismic device according to the present invention has one end and the other end having a base end fixed at two points where relative displacement occurs, and a free end overlapped with each other via a friction surface. And a sloped surface formed on the outer surface of the free end portion of each of the two members corresponding to the frictional surface, respectively, which faces toward the base end side parallel to each other, and for pressing between the two sloped surfaces. A shaft member extending vertically on the inclined surface is provided.

The shaft member is a bolt extending through the free ends of the one and other members and a nut screwed to the bolt.

The bolt is a round head bolt, and the nut is a spherical nut.

One of the free ends of the one and the other members has an elongated hole extending in a direction connecting the two points, and the bolt extends through the elongated hole and the inclined surface. An elastic body is interposed between the nuts.

Further, the friction damper for an earthquake-resistant device of the present invention comprises:
The first and second friction surfaces are separated in the direction connecting the two points.
Wherein the inclined surface is provided at a position corresponding to each of the first and second friction surfaces, and one of the free ends of the one and the other members is the first friction surface. A long hole extending in a direction connecting the two points at a position corresponding to the surface, and the other of the free ends of the one and the other members corresponds to the second friction surface. The bolt has a long hole extending in a direction connecting the bolts, the bolt extends through the long hole and the inclined surface, respectively, and an elastic body is interposed between the inclined surface and the nut.

The first and second friction surfaces are deviated to one and the other, respectively, from a line connecting the two points. Further, the elastic body is an axial force adjusting spring for keeping the axial force constant.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

A first embodiment of the friction damper of the present invention is shown in FIG.
As shown in the figure, an upper plate 10 having its base end fixed to the lower end of the upper brace portion 3a of the seismic and vibration damping brace 3, and its base end being the lower brace portion 3b of the seismic and vibration damping brace 3.
And the lower plate 11 having its free end overlapped with the lower surface of the free end of the upper plate 10 and the lower plate 11 converging toward the base end thereof in contact with the upper surface of the free end of the upper plate 10. Inclined upper surface 12
an upper inclined block 12 having a triangular cross section having a, and an inclination converging toward a base end side thereof, which is in contact with the lower surface of the free end of the lower plate 11 and is parallel to the inclined upper surface 12a of the upper inclined block 12. A lower inclined block 13 having a triangular cross section having a lower surface 13a, and a long hole 6 for bolt insertion formed in the upper plate 10 extending in the axial direction of the brace 3;
A similar long hole 7a formed in the lower plate 11 corresponding to the long hole 6 of the upper plate 10, a bolt insertion hole 14 having a truncated conical cross section provided through the upper inclined block 12,
Similarly, a bolt insertion hole 15 having a truncated conical cross section provided through the lower inclined block 13 and the block 12,
13 holes 14, 15 and the long holes 6, 6 of the upper plate 10 and the lower plate 11.
It comprises a bolt 16 penetrating through 7a and a nut 17 screwed onto the bolt 16.

Since the friction damper of the present invention has the above-described structure, when the building shakes due to wind or earthquake and a tension or a compressive force is generated in the anti-seismic and vibration control brace 3, the bolt 16 and the nut 17 are used. Upper plate 10 against the tightening force of
Slides relative to the lower plate 11, and the friction of the slip absorbs the energy of the wind and the earthquake.

Further, since the bolt 16 is inclined by the inclined upper surface 12a and the inclined lower surface 13a with respect to the friction surface 18 where the upper plate 10 and the lower plate 11 overlap, as shown in FIG. The tightening force of the nut 17 is N, and the inclination angle of the bolt 16 with respect to the vertical direction of the friction surface 18 where the upper plate 10 and the lower plate 11 overlap is α.
Then, the upper plate 10 and the lower plate 11 have the friction surface 1
A force Ncosα is applied in a direction perpendicular to the direction 8, and a force Nsinα is applied in such a manner that the upper plate 10 and the lower plate 11 shift in a direction approaching each other in the axial direction of the seismic and vibration damping brace 3.

Therefore, tension acts on the friction damper,
When the upper plate 10 slides relatively to the lower plate 11, if the friction coefficient between the upper plate 10 and the lower plate 11 is μ, the tension Pt borne by the friction damper becomes a frictional force μN
cosα and the sum of the forces Nsinα that cause the upper plate 10 and the lower plate 11 to shift toward each other.
The tension Pt is Pt = N (μcosα + sinα).

Further, a compressive force acts on the friction damper,
When the upper plate 10 slides relative to the lower plate 11, the compression force Pc borne by the friction damper is equal to the friction force μNcos
Since α is a value obtained by subtracting a force Nsinα for shifting the upper plate 10 and the lower plate 11 in a direction approaching each other,
The compression force Pc is Pc = N (μcosα−sinα).

As described above, the first embodiment of the friction damper of the present invention.
According to the embodiment, the difference between the force of the friction damper of the tension Pt and the compression force Pc can be provided, and the force of the damper of the compression force Pc can be reduced. The cross-sectional area of the lower plate 11, the brace, and the like can be made smaller than before.

The difference between the tension Pt and the compressive force Pc can be arbitrarily set by appropriately changing the friction coefficient μ and the inclination angle α of the bolt 16 with respect to the vertical direction of the friction surface 18.

Also, the wedge action of the inclined block allows
As the bolt moves in the direction of extension and the compression axial force increases, the tensile load increases, but the upper plate and the lower plate also slide against the inclined block, and this tensile load increases beyond a certain level. do not do. Further, when a compressive force is applied, since the distance between the inclined blocks moves in a direction to decrease, the axial force of the bolt is released, and the compressive load finally becomes zero.

FIG. 3 shows a friction damper of the present invention using a round head bolt 19 having a spherical head and a nut 20 instead of using the bolt 16 and the nut 17 in the first embodiment of the friction damper of the present invention. A second embodiment will be described.

In the second embodiment of the friction damper of the present invention, similarly to the first embodiment of the present invention, the upper plate 10 is attached to the lower plate 11 against the tightening force of the bolt 19 and the nut 20. The slip and the friction caused by the slip absorb the energy of the wind and the earthquake.

The relationship between the relative movement distance δ between the upper plate 10 and the lower plate 11 of the friction damper according to the second embodiment of the present invention and the tension / compression force borne by the friction damper is calculated as follows. be able to.

That is, as shown in FIG. 4, when the tension or compression force is not generated in the friction damper, the initial inclination angle of the round head bolt 19 with respect to the vertical direction of the friction surface 18 is α, and the tension or compression is applied to the friction damper. When a force is generated and the round head bolt 19 is tilted about its head, the angle is θ, the length of the round head bolt 19 is L, and the round head bolt 19 is tilted θ about its head. When the bolt length is L
(Θ), if the friction coefficient between the upper plate 10 and the lower plate 11 is μ ₁ , and the friction coefficient between the lower plate 11 and the lower inclined block 13 is μ ₂ , tension acts on the friction damper and the upper plate 10 Is relatively slipped with respect to the lower plate 11 and the bolt length L (θ) when the bolt 19 is tilted by θ is represented by Equations 1 and 2 by the sine theorem, focusing on the triangle ABC shown in FIG. It can be expressed as.

[0027]

(Equation 1)

[0028]

(Equation 2)

Further, assuming that the initial axial force of the bolt 19 is N (0), the axial force when the bolt 19 is tilted by θ is N (θ).
Then, the axial force N (θ) can be expressed as in Equation 3. In addition,
A is the effective sectional area of the bolt, and E is the Young's modulus of the steel material.

[0030]

(Equation 3)

If the bolt 19 is excessively stretched, the axial force N (θ) does not exceed the bolt proof stress, so the condition of Equation 4 is required.

[0032]

(Equation 4)

When an initial axial force N (0) is applied to the bolt 19, the inclination of the bolt 19 causes the upper plate 10 and the lower plate 11 to shift in a direction approaching each other.
Since sinα acts, the upper plate 1
In order to prevent slippage between 0 and the lower plate 11 and between the lower inclined block 13 and the lower plate 11, the conditions of Expressions 5 and 6 are necessary.

[0034]

(Equation 5)

[0035]

(Equation 6)

However, when both ends of the friction damper are fixed by seismic resistance, vibration damping braces, etc., even if the initial axial force N (0) is introduced to the bolt 19, the friction damper is fixed. There is no need to consider the conditions.

As described above, when the tension Pt is applied to the friction damper, assuming that the upper plate 10 starts to slide relative to the lower plate 11, the burden tension Pt (θ) is given by the following equation (7).
Becomes

[0038]

(Equation 7)

It is to be noted that immediately before the upper plate 10 and the lower plate 11 slide out, there is no inclination of the bolt 19, so that θ = 0, the slip-out tension Pt (0) is expressed by the following equation (8).

[0040]

(Equation 8)

The upper plate 10 and the lower plate 11 are slide bolts 19
When the inclination angle θ satisfies the condition of Equation 9, the lower plate 11 and the lower inclination block 13 begin to slide.

[0042]

(Equation 9)

At this time, if the elongated bolt 19 is within the elastic range, the equation 3 can be used as it is, and the inclination angle θ of the bolt 19 does not increase any more, so that the reaction force (sin) for further extending the bolt 19 is obtained. (Θ + α)), only the frictional force between the upper plate 10 and the lower plate 11 and the frictional force between the lower plate 11 and the lower inclined block 13 are obtained, and the maximum load tension Ptmax becomes several tens. .

[0044]

(Equation 10)

Here, since there is a relationship of Equation 11, Ptmax becomes Equation 12 from Equations 3 and 9.

[0046]

[Equation 11]

[0047]

(Equation 12)

Further, a compressive force acts on the friction damper, so that the upper plate 10 slides relatively to the lower plate 11 and the bolt 1
The compression force Pc (θ) when 9 is tilted by θ is given by Expression 13.

[0049]

(Equation 13)

Immediately before the upper plate 10 and the lower plate 11 start sliding, the bolt 19 has no inclination, so from θ = 0, the sliding compression force Pc (0) is given by Expression 14.

[0051]

[Equation 14]

When the axial force N (θ) of the bolt 19 is zero, the axial force is lost, so that Pc = 0.

From the above calculation, the moving distance δ between the upper plate 10 and the lower plate 11 of the friction damper in the second embodiment of the present invention is described.
The relationship between the frictional force and the load tension / compression force of the friction damper can be expressed as shown in FIG.

Table 1 is a calculation example of the relationship between the moving distance δ of the upper plate 10 and the lower plate 11 of the friction damper and the tension / compression force of the friction damper in the second embodiment of the present invention.
Table 2 shows the conditions.

[0055]

[Table 1]

[0056]

[Table 2]

Table 3 shows another calculation example, and Table 4 shows various conditions.

[0058]

[Table 3]

[0059]

[Table 4]

FIG. 6 shows a third embodiment of the present invention. In this embodiment, unlike the first embodiment, the upper inclined block 12 and the lower inclined block 13 are respectively provided on the upper surface of the upper plate 10. And fixed to the lower surface of the lower plate 11 and the upper plate 10
A long hole 14a for bolt insertion is provided in the upper inclined block 12 so as to extend in the axial direction of the seismic and vibration damping brace 3 corresponding to the long hole 6 of the lower inclined block 1.
3 and the lower plate 11 are provided with holes 15a and 7 having a diameter corresponding to the diameter of the bolt 21, respectively, so as to penetrate the block 12 and the upper plate 10 with the long holes 14a and 6 and the block 13 and the lower plate 11 with the holes. A bolt 21 is passed through each of the bolts 7 and 15a, and a nut 22 is screwed into the bolt 21. An axial force adjusting spring 23 is provided between the bolt head, the nut 22, and the inclined upper surfaces 12a and 13a of the blocks 12, 13, respectively. Is inserted.

In the third embodiment of the present invention, when tension is applied to the friction damper, the axial force adjusting spring 23 contracts as shown in FIG.
8, when the compressive force is applied to the friction damper, the axial force adjusting spring 23 is extended as shown in FIG. Is moved to the left, and the axial force applied to the bolt 21 can be kept constant.

FIG. 9 shows a fourth embodiment of the present invention. In this embodiment, the friction surface 18 between the upper plate 10 and the lower plate 11 is formed at two places 18a and 18b separated in the longitudinal direction. An upper inclined block 24a is integrally fixed to the upper surface of the upper plate 10 portion forming the first friction surface 18a, and the lower inclined block 25a is inclined to the lower surface of the lower plate 11 similarly to the upper inclined block 24a. Are fixed together.

The upper plate 10 and the upper inclined block 2
A long hole 26a extending in the axial direction of the brace 3 is provided through 4a, and a hole 27a having a diameter corresponding to the diameter of the bolt 21a is provided through the lower plate 11 and the lower inclined block 25a.

A lower inclined block 25b is integrally fixed to the lower surface of the lower plate 11 forming the second friction surface 18b, and the same as the lower inclined block 25b is fixed to the upper surface of the upper plate 10. The inclined upper inclined block 24b is fixed integrally.

The upper plate 10 and the upper inclined block 2
4b, a hole 27b having a diameter corresponding to the diameter of the bolt 21b is provided through the lower plate 11 and the lower inclined block 25b.
Is provided through a slot 26b extending in the axial direction of the booth 3.

Further, a bolt 21a is passed through the long hole 26a of the upper inclined block 24a and the upper plate 10, and the hole 27a of the lower inclined block 25a and the lower plate 11, and a nut 22a is screwed into the bolt 21a. An axial force adjusting spring 23a is inserted between the bolt head, the nut 22a and the inclined upper and lower surfaces of the blocks 24a and 25a, respectively.

Similarly, a bolt 21b is passed through the hole 27b of the upper inclined block 24b and the upper plate 10, and the elongated hole 26b of the lower inclined block 25b and the lower plate 11, and a nut 22b is screwed into the bolt 21b. An axial force adjusting spring 23b is inserted between the bolt head, the nut 22b, and the inclined upper and lower surfaces of the blocks 24b and 25b, respectively.

FIG. 10 shows a state where a compressive force is applied to the upper plate 10 and the lower plate 11.

In the fourth embodiment of the present invention, similarly to the third embodiment of the present invention, even if the upper plate 10 and the lower plate 11 move relative to each other in the axial direction, the axial force applied to the bolt 21 is increased. Becomes constant. That is, as shown in FIG. 11, the load characteristics of the friction damper of the present invention using the spring for adjusting the axial force as compared with the conventional friction damper are such that the compression force is weakened and the tensile force is increased, and in the case of FIG. Simpler than that.

In the fourth embodiment, as shown in FIG. 9, if the first and second friction surfaces 18a and 18b are displaced up and down with respect to the axis of the seismic and vibration damping brace, the axis of the brace can be obtained. And the axis of the friction damper can be matched.

Each of the above embodiments is an example in which the friction damper 2 is inserted in the middle part of the earthquake-resistant and vibration-damping brace 3.
As shown in FIG. 14, it can be inserted between the building 1 and the brace 3. Further, the bolt and the nut may be a screw rod and a nut screwed to both ends thereof. FIG.
As shown in FIG. 2, if the inclination of the inclined blocks 12 and 13 is reversed from that in the example shown in FIG. 1, the load characteristics shown in FIG. 13 in which the compressive force is strong and the tensile force is weakened can be obtained. Useful for configuration.

[0072]

As described above, according to the friction damper of the present invention, the load exerted on the friction damper at the time of compression can be reduced, so that the sectional area of the anti-seismic, vibration damping brace and friction damper can be designed to be small and economical. Can be targeted.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a first embodiment of a friction damper according to the present invention.

FIG. 2 is an explanatory diagram of a force generated on a friction surface of the first embodiment of the friction damper of the present invention.

FIG. 3 is a longitudinal sectional side view of a second embodiment of the friction damper of the present invention.

FIG. 4 is an explanatory diagram of the friction damper shown in FIG.

FIG. 5 is a view showing tensile and compression characteristics of a friction damper according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional side view of a third embodiment of the friction damper of the present invention.

FIG. 7 is a longitudinal sectional side view when receiving a tensile force of the friction damper shown in FIG. 6;

8 is a longitudinal side view when a compressive force of the friction damper shown in FIG. 6 is received.

FIG. 9 is a longitudinal sectional side view of a fourth embodiment of the friction damper of the present invention.

10 is a longitudinal sectional side view when receiving a compressive force of the friction damper shown in FIG. 9;

FIG. 11 is an explanatory view of load characteristics of a third or fourth embodiment of the friction damper of the present invention.

FIG. 12 is a longitudinal sectional side view of an embodiment when the inclined surface of the friction damper of the present invention is reversed.

13 is an explanatory diagram of load characteristics of the friction damper shown in FIG.

FIG. 14 is a side view showing another example of use of the friction damper of the present invention.

FIG. 15 is a side view of a conventional anti-seismic, vibration-damping brace interposed with a friction damper.

FIG. 16 is a vertical side view of a conventional friction damper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Building 2 Friction damper 3 Seismic and vibration control brace 3a Upper brace part 3b Lower brace part 4 Upper plate 5 Lower plate 6 Long hole 7 Bolt through hole 7a Long hole 8 Bolt 9 Nut 10 Upper plate 11 Lower plate 12 Upper inclined block 12a inclined upper surface 13 lower inclined block 13a inclined lower surface 14 bolt insertion hole 14a long hole 15 bolt insertion hole 15a hole 16 bolt 17 nut 18 friction surface 18a friction surface 18b friction surface 19 bolt 20 nut 21 bolt 21a bolt 21b bolt 22 Nut 22a Nut 22b Nut 23 Spring 23a Spring 23b Spring 24a Upper inclined block 24b Upper inclined block 25a Lower inclined block 25b Lower inclined block 26a Long hole 26b Long hole 27a hole 27b hole

Claims (7)

[Claims] 1. One and the other members having a base end fixed at two points where relative displacement occurs and a free end overlapped with each other via a friction surface, and an outer surface of the free end of the two members. An inclined surface formed to correspond to the friction surface and converging toward the base end side parallel to each other, and a shaft member extending vertically to the inclined surface for pressing between the inclined surfaces. Characteristic friction damper for seismic devices. 2. The friction for an anti-seismic device according to claim 1, wherein the shaft member is a bolt extending through the free ends of the one and other members and a nut screwed to the bolt. damper. 3. The friction damper according to claim 2, wherein the bolt is a round head bolt and the nut is a spherical nut. 4. One of the free ends of the one and other members has an elongated hole extending in a direction connecting the two points, and the bolt extends through the elongated hole and the inclined surface, and 4. A friction damper for an anti-seismic device according to claim 2, wherein an elastic body is interposed between the surface and the nut. 5. The friction surface comprises first and second friction surfaces separated from each other in a direction connecting the two points, and the inclined surface is formed by the first and second friction surfaces.
Are provided at positions corresponding to the first and second friction surfaces, respectively.
One of the free ends of the one and the other members is
A long hole extending in a direction connecting the two points at a position corresponding to the first friction surface, and one of the free ends of the one and the other members is at a position corresponding to the second friction surface. It has a long hole extending in the direction connecting the two points, the bolt extends through the long hole and the inclined surface, respectively, and an elastic body is inserted between the inclined surface and the nut. The friction damper for an earthquake-resistant device according to claim 2 or 3, wherein 6. The friction damper for an anti-seismic device according to claim 5, wherein the first and second friction surfaces are deviated to one and the other from a line connecting the two points. 7. A friction damper for an anti-seismic device according to claim 4, wherein the elastic body is an axial force adjusting spring for keeping the axial force constant.