JP2001050336A - Friction damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction damper to regulate both acceleration response and displacement response to an optimum, prevent the occurrence of a residue of displacement, and provide displacement proportional type damping performance. SOLUTION: A slide plate 16 is situated on the upper surface 12a of a floor 12 and a friction body 18 is situated thereon. The central part of the friction body 18 is rotatably supported at an object 14 to be base-isolated through a pin 22. Helical extension springs 26 and 26 are caused to horizontally span in a tension exerted state between support poles 24 and 24 erected on the floor 12 and the two end parts of the friction body and situated on a line (s) of action situated eccentrically downward from the pin 22 being the rotation center of the friction body 18. Further, the slide material 18b of the friction body 18 is brought into contact in a non-pressure contact state with the slide plate 16 or suspended from a support bracket 20 with slight gap therebetween.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction damper that absorbs displacement energy between two objects that are relatively displaced by a frictional force.

[0002]

2. Description of the Related Art Vibration isolation structures against earthquakes and the like are often used in buildings and floors of precision instrument rooms, etc. In addition, valuable display materials are also installed on display stands such as museums. It is designed to prevent it from falling and being damaged by vibration. By the way, as a general vibration isolating structure, there is a structure in which a vibration isolating object is supported on a foundation side via a laminated rubber bearing or a rolling bearing, and further, an elastic bearing such as a coil spring or a friction damper is used in combination.

A conventional friction damper 1 has a sliding member 4 and a sliding plate 5 interposed between a vibration-isolated object 2 and a foundation 3 as shown in FIG. Object 2
The load is applied to press the sliding member 4 against the sliding plate 5. When the object 2 and the foundation 3 are relatively displaced, the yield shear resistance represented by the product of the pressure P acting between the sliding member 4 and the sliding plate 5 and the friction coefficient μ. A force (frictional resistance) Qy is generated, and the yield shear resistance Qy can absorb energy at the time of relative displacement between the vibration-isolation target 2 and the foundation side 3.

At this time, the yield shear resistance Qy and the displacement δ
Is related to Q- which is a hysteresis loop shown in FIG.
The initial response (part A in FIG. 11) to the strong motion input in this Q-δ characteristic is as shown in FIG. 12, when Qy is increased, the acceleration increases and the displacement decreases, and when Qy decreases, the acceleration decreases. The acceleration is small and the displacement is large. Therefore, depending on how to set Qy, FIG.
The relationship between the response acceleration and the response displacement shown in FIG. 3 is obtained. By the way, it is desirable that both the response acceleration and the response displacement during a strong earthquake be reduced as a vibration isolation structure.

[0005]

However, in order to optimize both the response acceleration and the response displacement, it is necessary to reduce Qy at the initial stage of displacement and to increase Qy as the displacement increases. However, in the conventional friction damper, since the pressing force P and the friction coefficient μ are constant, the ideal damping performance cannot be obtained. Therefore, in order to obtain ideal damping performance, a viscous damper or the like whose yield shear resistance Qy is not clear is used.

However, when a display stand of a museum or the like is constructed as a vibration-isolating table by using a vibration-isolating structure, even if the vibration-isolating structure itself is destroyed by a large earthquake, the exhibits are not stained and are maintenance-free. Therefore, it is necessary to avoid using a wet damper such as the above-mentioned viscous damper. For this reason,
In order to satisfy the requirements as a vibration isolator, a dry friction damper will be used.

For this reason, in the conventional friction damper which cannot satisfy both the response acceleration and the response displacement, as shown in FIG. 13, the point R where the two are compromised is set as the optimum value of the friction damper, and the pressure P and the friction coefficient μ are determined. The decision is made. For this reason, the lower limits of the response acceleration and the response displacement are inevitably limited, and in the case of the dry friction damper, the displacement is inevitably left after the external displacement force is lost, and does not return to the neutral position. Further, as another example of the dry damper, there is an elasto-plastic damper that utilizes a plastic strain region of a steel material for energy absorption. In this case, the Q-δ characteristic shown in FIG. There is a problem that there is a problem similar to that of the friction damper.

Accordingly, the present invention has been made in view of such a conventional problem, and has a displacement proportional type damping performance which can adjust both the acceleration response and the displacement response more optimally and has no residual displacement. It is an object of the present invention to provide a friction damper.

[0009]

In order to achieve the above object, a friction damper according to a first aspect of the present invention comprises a sliding surface provided on one of first and second objects which are relatively displaced; A friction member that is rotatably provided on the other of the second object and opposed to the sliding surface, is in a non-pressure contact state with the sliding surface in a neutral position, and is in pressure contact with the sliding surface in a rotating state; A friction member is provided between the friction member and one of the first and second objects to maintain a neutral position of the friction member and rotate the friction member in accordance with the relative displacement of the first and second objects. And an elastic member for increasing a pressing force on the sliding surface in proportion to a relative displacement amount of the first and second objects.

According to this configuration, the friction body is in the neutral position when there is no relative displacement, and this neutral position is maintained by the elastic member. On the other hand, when the first and second objects are relatively displaced from each other, the friction member is rotated by the elastic member and pressed against the sliding surface. Since the pressing force at this time is increased in proportion to the relative displacement of the first and second objects, the frictional force generated between the friction body and the sliding surface increases as the input external force increases and the relative displacement increases. And its damping force increases.
Therefore, the damping force proportional to the displacement can be obtained by satisfying both the response acceleration and the response displacement. When the input external force causing the relative displacement disappears, the friction member is returned to the neutral position by the elastic member, but during the period from the return process to the neutral position, the frictional resistance force gradually decreases and the displacement remains. And the first and second objects can be restored to their original positions. Therefore, a displacement proportional damping force can be obtained by such a dry friction damper. When this friction damper is used for a vibration isolation table on which an exhibit is placed, a display table which is maintenance-free and has excellent vibration isolation performance without the possibility of soiling the exhibit can be obtained.

According to a second aspect of the present invention, there is provided a friction damper, wherein the elastic member is disposed on a line of action eccentric from a rotation center of the friction body in a direction of relative displacement of the first and second objects. A pair is provided on both sides of the rotation center.

According to this structure, when the first and second objects are displaced relative to each other, the tensile force of the elastic member acts on the line of action eccentric from the center of rotation of the friction body, so that the friction body is rotated. It is inclined and generates a pressing force against the sliding surface.
At this time, since the tensile force of the elastic member increases in proportion to the relative displacement amount of the first and second objects, the rotational moment acting on the friction body increases with this, and the pressing force increases,
As a result, the frictional resistance generated between the sliding surface and the sliding surface increases.

Further, in the friction damper according to a third aspect of the present invention, the elastic member is disposed so as to intersect with each other at an angle to a relative displacement direction of the first and second objects.
A pair of the friction members is provided on both sides of the rotation center thereof.

According to this configuration, when the tensile force changes in the elastic member due to the relative displacement of the first and second objects, the friction member is rotated by the difference in the tensile force of the elastic members provided on both sides of the friction member. , Generates a pressing force on the sliding surface. At this time,
Since the elastic members are arranged so as to intersect with each other at an angle to the relative displacement direction of the first and second objects, the difference in tensile force between the elastic members is opposite to the side on which the friction body is displaced. Is pressed against the sliding surface, and the pressing force is increased in proportion to the relative displacement. Further, since the elastic member is arranged at an angle with respect to the relative displacement direction of the first and second objects, the relative movement amount can be amplified and transmitted to the elastic member.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 5 show an embodiment of the friction damper of the present invention, FIG. 1 is a front view of the friction damper, FIG. 2 is a front view showing an operation state of the friction damper,
FIG. 3 is an explanatory view showing the direction of action of the pressing force of the friction damper,
FIG. 4 is a graph showing hysteresis, and FIG. 5 is a plan view showing an arrangement state of the elastic members.

The basic structure of the friction damper 10 of the present invention includes a sliding surface 16 provided on one of the first and second structures 12 and 14 which are relatively displaced, and the first and second structures 1 and 2.
A friction member 18 is provided on the other of the sliding surfaces 16 and 14 so as to be rotatable facing the sliding surface 16 so as to be in a non-pressure contact state with the sliding surface 16 in a neutral position and to be in pressure contact with the sliding surface 16 in a rotating state.
And the first and second structures 12, 14 are attached between the friction body 18 and one of the first and second structures 12, 14 so as to maintain the neutral position of the friction body 18.
The frictional body 18 is rotated in accordance with the relative displacement of the first and second structures 12 and 1 at that time.
Elastic members 26, 2 which increase in proportion to the relative displacement of
6 is provided.

That is, the friction damper 10 of this embodiment is
As shown in FIG. 1, it is arranged between a floor 12 as a first structure and a vibration-isolation target 14 as a second structure. The vibration isolating object 14 is supported on the floor 12 so as to maintain a constant interval H via an elastic bearing such as a laminated rubber or a spring (not shown), and
The floor 12 and the vibration-isolated object 1 with the shear deformation of the elastic bearing
4, a relative displacement in the horizontal direction is allowed. Here, for the sake of convenience, the left-right direction in the figure is a relative displacement direction V. A sliding plate 16 serving as a sliding surface is attached to an upper surface 12a of the floor 12 facing the vibration-isolation target 14, and a friction body 18 is arranged on the sliding plate 16. The friction body 18 is a block body 18a.
And a sliding member 18b integrally provided at both ends of the lower surface of the block body 18a in the relative movement direction V.

A support bracket 20 is vertically provided on the lower surface of the vibration-isolation target 14, and the center of the upper end of the block body 18a in the relative displacement direction V is rotatable via a pin 22 on the support bracket 20. Supported by In addition, the floor 1
The support pole 2 is symmetrically placed on the upper surface 12a of the support pole 2 at a predetermined distance from the friction body 18 in the relative displacement direction V.
4, 24 are erected. A tension coil spring 2 as an elastic member is provided between the support poles 24, 24 and both ends of the lower end of the block body 18a in the relative movement direction V.
6, 26 are stretched horizontally. Accordingly, the mounting positions of the coil springs 26, 26 are on the action line s which is eccentric below the pin 22, which is the center of rotation of the friction body 18. Further, the two coil springs 26 have the same spring constant and length, and the tensile force acting on the friction body 18 at the illustrated neutral position becomes equal.

The friction damper 10 constructed as described above
In the illustrated neutral position, the sliding member 18b of the friction member 18 is in contact with the sliding plate 16 in a non-pressing state, or the block member 18a is suspended from the support bracket 20 with a slight gap. Then, when an excitation force such as an earthquake is input and the floor 12 and the vibration-isolation target 14 are relatively displaced, the friction body 18 moves together with the vibration-isolation target 14 and shortens the coil spring 26 in the direction of displacement while opposing. Side coil spring 26 is pulled. Then, due to the difference in the tensile force between the two coil springs 26, 26, the friction body 18 is rotated clockwise in FIG.
Is pressed against the slide plate 16, and a damping force is generated by shear frictional resistance due to the pressing force at this time. This damping force is generated by the front and rear coil springs 26 and 2 as the relative displacement increases.
6 is increased by increasing the tensile force difference, and a damping force proportional to the displacement is generated.

FIG. 2 is an explanatory view showing the operation principle of the friction damper 10. The state of generation of the pressing (pressure) force ΔP when the relative displacement δ occurs between the floor 12 and the vibration-isolated object 14 is shown. Is shown. The pressing force at this time is obtained as ΔP = P + ΔP, and the shear frictional resistance is Q = μ · ΔP.

(A) P The coil springs 26, 26 have a length L0 in a neutral state, and when a relative displacement δ occurs on the side of the vibration-isolation target 14, the coil spring 26 in the direction opposite to the direction of displacement expands. The coil spring 26 in the direction of displacement contracts, and the tensile force difference T
Occurs. That is, T1 = (L0 + δ) · KT2 = (L0−δ) · KT = T1−T2

This tensile force difference T is a force for rotating the friction member 18 supported by the pin, and the moment balance at this time is the moment M = e 1 · T = e 3 · P.
P = (e1 / e3) · T = 2K (e1 / e3) · δ.
Here, e1, e2, and e3 are vertical eccentric distances between the pin 22, which is the center of rotation, and the action line s of the coil springs 26, 26, and vertical eccentricity between the pin 22 and the slide plate 16. The distance is the horizontal eccentric distance between the pin 22 and the pressure point. Here, K is a spring constant of the coil springs 26, 26.

(B) About ΔP ΔP is a pressing force generated when the displacement Δδ further increases and decreases at the displacement amount δ position, as shown in FIGS. 3 (a) and 3 (b). When it increases, a positive frictional resistance is generated, and when it decreases, a negative frictional resistance is generated.

When the displacement shown in (a) increases, the frictional resistance μP acts as a clockwise moment M around the pin 22. Of course, ΔP is generated in the process of the displacement progressing with a force exceeding the frictional resistance μP caused by the above-mentioned pressing force, and the pressing force ΔP is generated by the balance at this time. That is, M = e2μP = e3ΔP is derived,
Therefore, ΔP = (e2 / e3) · μP.

When the displacement shown in (b) decreases, the frictional resistance μP is reversed, and this frictional resistance is
A counterclockwise moment M is generated around the circumference, and a negative pressure ΔP is generated. That is, M = e2
(−μP) = e3 · ΔP, and therefore ΔP = − (e2
/ E3) · μP.

Next, the relationship between the displacement δ and the shear frictional resistance Q will be described. The total pressure applied by the friction body 18 to the sliding plate 16 is ΔP = P ± ΔP, and the frictional resistance Q is It is obtained as the product of the friction coefficient μ and the pressure ΔP. That is, Q = μ · (P ± ΔP) = μ · {1 ± (e2 / e3) · μ} · (e1 / e3) · K · 2δ.

FIG. 4 shows the hysteresis of Q-δ derived from the above equation. In the figure, the dotted line indicates the difference in spring tension (T1−
T2) is the resistance force, and the solid line is the hysteresis characteristic in consideration of the fluctuation pressurization ± ΔP. That is, the restoring force characteristic shows that the frictional resistance is large in the first quadrant when the displacement increases, the frictional resistance decreases in the fourth quadrant when the displacement decreases, and the frictional resistance increases when the displacement increases in the opposite direction of the third quadrant. And the frictional resistance decreases in the second quadrant when the displacement decreases.

Therefore, in the friction damper 10 of the present embodiment, when the floor 12 and the vibration isolating object 14 are relatively displaced,
As the relative displacement increases, the frictional resistance increases and a large damping force can be obtained, and both the response acceleration and the response displacement can be effectively reduced. Further, when the input external force causing the relative displacement disappears, the friction body 18 is returned to the neutral position by the spring force of the coil springs 26, 26, and the frictional resistance gradually decreases during the period from the return process to the neutral position. As a result, the displacement does not remain, and the vibration-isolation target object 14 can be automatically and reliably returned to the original neutral state.

Therefore, a displacement proportional damping damper can be constituted by the friction damper 10 of the dry type. When this friction damper 10 is used, for example, as a vibration isolation table on which an exhibit is placed, it is possible to obtain a display table that is maintenance-free and has excellent vibration isolation performance without the possibility of soiling the exhibit.

In the present embodiment, since the sliding plate 16 is provided on the upper surface of the floor 12, the relative displacement of the friction body 18 in all directions along the sliding plate 16 is allowed.
By radially arranging the coil springs 26 as shown in (1), horizontal displacement between the floor 12 and the vibration-isolation target 14 in all directions can be accommodated.

FIGS. 6 and 7 show another embodiment, in which the same components as those in the above-described embodiment are denoted by the same reference numerals, and a duplicate description will be omitted. FIG. 6 is a front view of the friction damper, and FIG.
Is a graph showing hysteresis.

That is, the friction damper 10a of this embodiment
Has a lower end portion of the friction body 18 rotatably supported via a pin 22 and a coil spring 26 mounted at a position above the pin 22 position. In this case, the coil spring 26 is horizontally arranged by raising the support pole 24, and is arranged on the action line s which is eccentric upward from the rotation center of the friction body 18.

Therefore, the friction damper 10 of this embodiment
In a, when the floor 12 and the vibration isolating object 14 move relative to each other, the acting direction of the difference in the tensile force between the coil springs 26, 26 is opposite to that in the above-described embodiment, and is a rear side with respect to the traveling direction of the friction body 18. Is pressed against the sliding plate 16.
Therefore, when the displacement increases, the pressure ΔP takes a negative value, and when the displacement decreases, the pressure ΔP takes a positive value.

For this reason, the friction damper 1 of the above embodiment is
The same function as 0 can be exerted, but the hysteresis at this time is as shown in FIG. 7, and the frictional resistance is small when the displacement increases and the frictional resistance increases when the displacement decreases.

In particular, in the displacement proportional type friction damper 10a of this configuration, since the damping rigidity when the displacement increases is small, the rigidity of the vibration isolating spring separately provided to obtain the vibration isolating effect is reduced. It does not contribute and can keep its long period. The damping force of the friction damper 10a acts greatly when the displacement decreases. Therefore, sufficient damping performance can be obtained while maintaining a long period.

The friction dampers 10 and 10a shown in the embodiments of FIGS. 1 and 6 disclose the case where the sliding plate 16 is provided on the floor 12 side. However, the present invention is not limited to this. It can also be provided on the side. Of course, in this case, the friction body 18 is supported on the floor 12 side, and the coil spring 26
Is supported by the vibration-isolation target object 14 side.

FIGS. 8 and 9 show another embodiment, in which the same components as those in the above embodiment are denoted by the same reference numerals and will not be described repeatedly. FIG. 8 is a bottom view showing a main part of the friction damper, and FIG. 9 is a front view.

That is, the friction damper 10b of this embodiment
Is applied to a vibration isolating structure of a linear bearing, and as shown in FIGS. 8 and 9, a rail 30 is attached to the lower surface of the vibration isolating object 14, and both side surfaces of the rail 30 are a pair of sliding surfaces. 32, 32. The friction bodies 34, 3 are opposed to the pair of sliding surfaces 32, 32, respectively.
4 are arranged.

Each of the friction members 34, 34 is formed in a rectangular plate shape and arranged horizontally, and the center of each friction member 34 is rotatably supported via a pin 38 on a support base 36 fixed to the upper surface of the floor 12. Then, a pair of coil springs 40, 40 as elastic members are respectively mounted between both ends of the friction bodies 34, 34 along the relative displacement direction V of the rail 30 and the lower surface of the vibration-isolation target 14. , The pair of coil springs 4
0 and 40 cross each other and are arranged at an angle to the relative displacement direction V of the rail 30.

Therefore, the friction damper 10 of this embodiment
The operating principle of b will be described with reference to FIGS. 8 and 9 described above. When the floor 12 and the vibration-isolation target 14 are relatively displaced, each of the coil springs 40, 40 is changed with the rotation angles θ1, θ2. , The respective tensile forces T1, T2 are changed.

At this time, the component forces of T1 and T2 in the X and Y directions are T1x = T1 · cos θ1, T1y = T1 · sin θ1 T2x = T2 · cos θ2, and T2y = T2 · sin θ2. The difference between these component forces T1x, T1y and T2x, T2y is
By giving a rotational moment M around the pin 38, the friction body 34
A pressure P is generated at the end of. At this time, P = M / e3
= {E1 (T1x + T2x) + e4 (T1y + T2y)} / e
It becomes 3.

By this pressure P, the shear frictional resistance Q =
μP is generated, and regarding the shear frictional resistance Q, the direction of the moment ΔM = e3 · μ · P generated around the pin 38 differs between when the displacement is increasing and when the displacement is decreasing. Therefore, the increase / decrease ΔP of the pressing force at this time is ΔP =
± ΔM / e3 = ± e2μP / e3. Therefore, the shear frictional resistance Q actually generated is Q = μ · (P ±
ΔP).

Here, a positive value of ΔP is when the displacement is increased, and a negative value is when the displacement is decreased. Further, μ is a coefficient of friction, and e1, e2, e3, and e4 are eccentric distances shown in FIG. e1 is 0 when the friction body 34 is not rotating.

Therefore, in this embodiment, the displacement proportional type friction damper 10b can be constructed, and the sliding surfaces 32, 32 have the same functions as those of the above-described embodiment. And the friction members 34 are disposed on the pair of sliding surfaces 32, 32, respectively, so that each friction member 34 applies a pressing force P to the sliding surfaces 32, 32 from both sides with the rail 30 interposed therebetween. For this reason, the pressing forces P on both sides are offset, and the rail 30 can be prevented from being biased. Also, the rotation direction of the friction body 34 is the floor 1
Since it is at right angles to the direction in which the object 2 and the vibration-isolation target 14 are opposed to each other, that is, in the present embodiment, the space is between the floor 12 and the vibration-isolation target 14.

By the way, in this embodiment, each friction body 34
Although the case in which the pair of coil springs 40, 40 provided in the above are crossed is disclosed, even when the coil springs 40, 40 are not crossed, the rotation direction of the friction body 34 with respect to the displacement is reversed. Similarly, a frictional resistance force proportional to the displacement can be generated. Further, the rail 30 may be provided on the floor 12 side without being provided on the vibration isolation target 14 side. In this case, the friction body 34 is supported on the vibration isolation target 14 side, and the coil spring 40 is supported on the floor 12 side. Will do.

[0046]

As described above, in the friction damper according to the first aspect of the present invention, when the first and second objects are relatively displaced, the friction member is rotated by the elastic member and pressed against the sliding surface. However, since the pressing force at this time is increased in proportion to the relative displacement of the first and second objects, a displacement proportional friction damper that satisfies both the acceleration response and the displacement response can be configured. . When the input external force causing the relative displacement disappears, the friction body is returned to the neutral position by the elastic member, but during the time from the return process to the neutral position, the frictional resistance gradually decreases and the displacement remains. Can be prevented, and the original position can be reliably restored. Accordingly, a displacement proportional damping force can be obtained by the dry friction damper.

Further, in the friction damper according to the second aspect of the present invention, when the first and second objects are relatively displaced, the tensile force of the elastic member acts on the action line eccentric from the rotation center of the friction body. The friction body is rotated and inclined to generate a pressing force on the sliding surface, and the tensile force of the elastic member increases in proportion to the relative displacement of the first and second objects. Along with this, the rotational moment acting on the frictional body increases, so that the above-mentioned pressing force increases, so that the frictional resistance generated between the frictional body and the sliding surface can be increased.

Further, in the friction damper according to the third aspect of the present invention, when the tensile force changes in the elastic member due to the relative displacement of the first and second objects, the difference in the tensile force between the elastic members provided on both sides of the friction body. As a result, the friction member is rotated to generate a pressing force on the sliding surface. At this time, the elastic member is
Since the first and second objects are arranged so as to intersect with each other at an angle with respect to the relative displacement direction, the difference in the tensile force of the elastic member is set on the sliding surface on the side opposite to the side on which the friction body is displaced. By pressing, the pressure can be increased in proportion to the relative displacement. Further, since the elastic member is arranged at an angle with respect to the relative displacement direction of the first and second objects, the relative movement amount can be amplified and transmitted to the elastic member.

[Brief description of the drawings]

FIG. 1 is a front view of a friction damper showing one embodiment of the present invention.

FIG. 2 is a front view of an operation state of the friction damper according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of an action direction of a pressing force of a friction damper according to the embodiment of the present invention.

FIG. 4 is a graph of a hysteresis of a friction damper showing one embodiment of the present invention.

FIG. 5 is a plan view of an arrangement of an elastic member of the friction damper according to the embodiment of the present invention.

FIG. 6 is a front view of a friction damper showing another embodiment of the present invention.

FIG. 7 is a graph of a hysteresis of a friction damper according to another embodiment of the present invention.

FIG. 8 is a bottom view of a main part of a friction damper showing another embodiment of the present invention.

FIG. 9 is a front view of a friction damper showing another embodiment of the present invention.

FIG. 10 is a front view of a conventional friction damper.

FIG. 11 is a restoring force characteristic diagram of a conventional friction damper.

12 is a restoring force characteristic diagram showing a portion A in FIG. 11 taken out.

FIG. 13 is a characteristic diagram showing response characteristics of an elastic spring and a friction damper vibration isolating structure of a conventional friction damper.

FIG. 14 is a restoring force characteristic diagram of a conventional steel damper.

[Explanation of symbols]

 10, 10a, 10b Friction damper 12 Floor (first structure) 14 Object to be isolated (second structure) 16 Sliding plate (sliding surface) 18, 34 Friction body 22, 38 Pin (rotation center) 26, 40 Coil spring (elastic member) 30 Rail 32 Sliding surface

Claims (3)

[Claims] A sliding surface provided on one of the first and second objects which are relatively displaced; and a neutral surface provided on the other of the first and second objects so as to be rotatable in opposition to the sliding surface. A friction member that is not pressed against the sliding surface at the position and is pressed against the sliding surface in a rotating state; and a friction member provided between the friction member and one of the first and second objects. While maintaining the neutral position,
An elastic member for rotating the friction body in accordance with the relative displacement of the second object to increase a pressing force on the sliding surface in proportion to the relative displacement amount of the first and second objects. Characteristic friction damper. 2. A pair of elastic members are provided on both sides of the center of rotation on an action line in the direction of relative displacement of the first and second objects and eccentric from the center of rotation of the friction body. The friction damper according to claim 1, wherein 3. The elastic member is disposed so as to intersect with each other at an angle to the relative displacement direction of the first and second objects, and a pair of elastic members are provided on both sides of the rotational body with respect to the friction body. The friction damper according to claim 1, wherein the friction damper is provided.