JP2004052835A - Damper and structure equipped with damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction force variable damper capable of obtaining a necessary damping force even if the supply of the voltage and/or current has stopped. <P>SOLUTION: The damper 1 is equipped with a first member 10 and a second member 20, and using the frictional resistance force acting between the first and second members, damps the relative vibration of the two members, and has a means 30 to give a force so as to increase the frictional resistance force and an actuator 40 to generate a force so as to decrease the frictional resistance force. Thereby the friction force variable damper can exert the required damping force even in the event of power failure. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a damper for absorbing energy to reduce vibration. In particular, it relates to a damper that absorbs energy using frictional force. Further, the present invention relates to a structure provided with such a damper.
[0002]
[Background Art]
When two members vibrate relatively, a damper is widely used as a means for damping the vibration.
Also, as such a damper, an active damper that can be controlled to obtain a desired damping force is known.
[0003]
[Problems to be solved by the invention]
Usually, since the active damper controls the damping force of the damper by controlling the actuator, the damping force cannot be controlled when the supply of the voltage or the current to the actuator is stopped at the time of a power failure or the like.
However, there is a need for an active damper that can maintain a necessary damping force even during such a power failure.
An object of the present invention is to provide a damper that can obtain a necessary damping force even when supply of voltage or current is stopped.
[0004]
[Means for Solving the Problems]
A main invention for achieving the above object includes a first member and a second member, and uses a frictional resistance force acting between the first member and the second member to make a relative relationship between the two members. A damper for attenuating vibration, comprising: means for applying a force so as to increase the frictional resistance; and an actuator for generating a force so as to decrease the frictional resistance.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
=== Overview of this embodiment ===
At least the following matters will be made clear by the description in the present specification and the accompanying drawings.
A damper comprising a first member and a second member, wherein the damper attenuates relative vibration between the two members by utilizing a frictional resistance force acting between the first member and the second member. A damper comprising: means for applying a force so as to increase the resistance; and an actuator for generating a force so as to reduce the frictional resistance. According to such a damper, a necessary damping force can be obtained even if the voltage or current supplied to the actuator is stopped.
[0006]
In the damper, it is preferable that the first member includes two plate members sandwiching the second member, and the actuator is provided between the two plate members. According to such a damper, the object of the present invention can be achieved with a simple configuration.
[0007]
In the above damper, it is preferable that the actuator generates a force using a piezoelectric effect. According to such a damper, by controlling the voltage to the actuator, the frictional resistance between the first member and the second member can be controlled.
[0008]
In this damper, it is preferable that the means causes the actuator to contract through the first member. According to such a damper, the piezoelectric element can be used in a state where the piezoelectric element is contracted in advance.
[0009]
In addition, it is preferable that the damper includes an adjusting unit that adjusts a force in a direction to contract the actuator. According to such a damper, the initial state of the actuator can be adjusted to a desired state.
[0010]
In this damper, it is preferable that a frictional resistance when no voltage is applied to the actuator is larger than a frictional resistance when a voltage is applied to the actuator. According to such a damper, a necessary damping force can be obtained even when the supply of the voltage or the current is stopped.
[0011]
In the above damper, it is preferable that the means applies a force to the first member using elastic deformation of a spring. According to such a damper, the object of the present invention can be achieved with a simple configuration.
[0012]
In this damper, it is preferable that the means applies a force to the first member by using a spring that deforms nonlinearly. According to such a damper, the force applied to the first member can be stabilized.
[0013]
Further, a structure provided with such a damper is also within the scope of the present invention. According to such a structure, the vibration energy of the structure can be effectively absorbed and the vibration can be attenuated regardless of the magnitude of the earthquake.
[0014]
=== Damper configuration ===
<Overall configuration of damper>
FIG. 1 is an explanatory diagram of the damper of the present embodiment. FIG. 2 is a diagram when the damper of FIG. 1 is viewed from the side. In both figures, a cross-sectional view is partially used and a perspective view is partially used for description.
[0015]
The damper 1 mainly includes a first member 10, a second member 20, a fastening unit 30, and an adjusting unit 40. Then, the damper 1 attenuates the relative vibration between the first member 10 and the second member 20 using the frictional resistance acting between the first member 10 and the second member 20.
[0016]
The first member 10 includes a first friction plate 12 and a second friction plate 14 as two plate members. The first friction plate 12 and the second friction plate 14 are provided to face each other. The first friction plate 12 has a first friction material 121, and the second friction plate 14 has a second friction material 141. The first friction material 121 and the second friction material 141 are for generating a frictional force with the second member 20 (described later), and exhibit a function as a brake material. The first friction material 121 and the second friction material 141 are provided to face each other. The first friction material 121 and the second friction material 141 are formed by selecting a material having a friction coefficient μ as needed.
[0017]
The second member 20 is disposed between the first friction plate 12 and the second friction plate 14, and is sandwiched between the first friction plate 12 and the second friction plate 14. The second member 20 is formed of a stainless steel plate or clad steel provided with a stainless steel plate on a contact surface with the first friction material 121 and the second friction material 141. The second member 20 has a rectangular through hole 20H. One surface of the second member 20 is in contact with the first friction material, and the other surface is in contact with the second friction material. The second member 20 is sandwiched between the first friction member 121 and the second friction member 141 by the fastening means 30 (described later), and when the second member 20 relatively oscillates with respect to the first member 10. Vibration energy is converted to heat energy by frictional resistance. The damper 1 absorbs (attenuates) the vibration by the frictional resistance.
[0018]
The fastening means 30 applies a force in a direction in which the first member fastens the second member (a direction in which the second member is sandwiched), and applies a force to the first member so as to increase the frictional resistance. The fastening means 30 includes a bolt 32, a nut 34, a disc spring 36, a washer 38A, a washer 38B, and a washer 38C. The bolt 32 and the nut 34 fasten the second member by the first member via the disc spring 36. When the bolts 32 and the nuts 34 are tightened, the first member tightens the second member, so that the first member and the second member (between the first friction material 121 and the second friction material 141 The frictional resistance between the second member and the second member increases. Further, when the bolt 32 and the nut 34 are loosened, the first member loosens the tightening of the second member, so that the first member is loosened between the first member and the second member (specifically, the first friction material 121 and the second The frictional resistance between the friction member 141 and the second member) decreases. By adjusting the amount of tightening of the bolt 32 and the nut 34 in this manner, an appropriate preload (pressing force) can be applied to the disc spring 36. The configuration and function of the disc spring 36 will be described later. The washer 38A is provided between the bolt 32 and the disc spring 36. The washer 38B is provided between the disc spring 36 and the first friction plate 121. The washer 38C is provided between the nut 34 and the second friction plate 141.
[0019]
The adjusting unit 40 includes a piezoelectric element 42, an adjusting screw 44, and a relay plate 46. The piezoelectric element 42 functions as an actuator that applies a force to the first member in a direction in which the first member is separated from the second member. The piezoelectric element 42 utilizes a piezo element that generates displacement when a voltage is applied, and is configured by stacking a plurality of thin piezo elements sandwiched between electrode plates. When a voltage is applied to the electrode plates at both ends of the piezo element, each piezo element is displaced in the direction of the electrode plate by the inverse piezoelectric effect, and the piezoelectric element 42 is displaced by a displacement amount obtained by accumulating the displacement of each piezo element. Further, the displacement generated in the piezo element changes according to the applied voltage, and thus the displacement of the piezoelectric element 42 is controlled by controlling the voltage. Further, the piezoelectric element 42 is provided between the first friction plate 12 and the second friction plate 14. Therefore, when a voltage is applied to the piezoelectric element 42, a force is generated in a direction to separate the first friction plate 12 and the second friction plate 14, and the frictional resistance decreases. This makes it possible to control the frictional resistance between the first member and the second member (specifically, between the first friction member 121 and the second friction member 141 and the second member) (described later). Then, by controlling the frictional resistance, the absorption (damping) of the vibration of the damper is controlled. In the configuration of the present embodiment, the piezoelectric element is contracted in advance by tightening the bolt 32 and the nut 34 of the tightening means 30 or by adjusting the adjusting means 40, and a preload is applied to the piezoelectric element in advance. be able to. Then, the initial state of the piezoelectric element 42 can be adjusted to a desired state by the adjusting means 40. The adjusting screw 44 and the relay plate 46 will be described later.
[0020]
<Belleville spring>
FIG. 3 is a cross-sectional view of a disc spring alone constituting the disc spring. FIG. 4 is a graph showing an example of the spring characteristics of the disc spring alone.
[0021]
In FIG. 3, S represents the plate thickness of the disc spring unit 36A, h represents the total deflection of the disc spring unit, Do represents the outer dimension of the disc spring unit, and Di represents the inner diameter of the disc spring. In the present embodiment, it is desirable to use a disc spring unit 36A having an h / S of 1.3 to 1.4. This is because, if the disc spring unit 36A whose h / S is smaller than 1.3 is used, a sufficient amount of deformation cannot be secured. Further, if the disc spring 36A whose h / S is larger than 1.4 is used, there is a possibility that a warp in the opposite direction may occur.
[0022]
In FIG. 4, the vertical axis represents the load P, and the horizontal axis represents the deflection σ of the disc spring 36A alone. The load characteristics of the disc spring unit 36A depend on its shape. The disc spring unit 36 of this embodiment has a region R where the load-displacement relationship is non-linear, as shown in FIG. The disc spring unit 36 of the present embodiment is used in the non-linear region R. Therefore, even if the amount of deflection σ of the disc spring unit 36A changes, the change in the load P is small. That is, the disc spring 36 can apply a constant preload (pressing force). In this embodiment, the bolt 32 and the nut 34 are adjusted so that the disc spring unit 36A is used in the non-linear region R.
[0023]
Specifically, the preload is set to 15 t and the amount of deflection at this time is set to about 10 mm in the disc spring unit 36A of the present embodiment so as to be used in the nonlinear region R. Even if the amount of deflection fluctuates in the range of ± 1 mm with respect to such a disc spring unit 36A, the fluctuation of the load P is suppressed to approximately ± 1 t (a fluctuation of approximately ± 7% with respect to the set preload 15 t). be able to. For example, if the single disc spring 36A is set to a deflection amount of 2.5 mm (when the single disc spring 36A is used in a linear region), the variation of the load P with respect to the variation of the deflection amount of ± 1 mm is about ± 2. 0.5t (a fluctuation of about ± 50% with respect to the set preload of about 5t).
[0024]
When the directions of the disc springs 36A are alternately superimposed in series, the amount of deflection can be adjusted according to the number of superposed springs. That is, when two disc springs 36A are stacked in series, the amount of deflection is doubled, and when three pieces are stacked, the amount of deflection is tripled. The disc spring 36 of the present embodiment is used in a state where two disc springs 26A are butted back to back.
[0025]
When the disc springs 36 are arranged in parallel, the repulsive force can be adjusted according to the number of the arranged disc springs. In other words, arranging two disc springs 36 in parallel results in a double repulsion force, and arranging three disc springs 36 results in a triple repulsion force. In the present embodiment, one disc spring 36 is used, but the present invention is not limited to this.
[0026]
<Relationship between applied voltage and frictional force>
FIG. 5 is a graph showing the relationship between the voltage applied to the piezoelectric element and the frictional resistance of the damper. In the present embodiment, as shown in FIG. FIG. 6 is an explanatory diagram of a force on the friction plate 12 (or the friction plate 14). In the drawing, P0 is the force by which the friction plate 12 tightens the second member, and P1 is the preload applied by the bolt 32 and the nut 34 via the disc spring 36 (the preload applied by the tightening means 30 to the first member 10). P2) is the axial force acting on the piezoelectric element 42. In the following description, P20 is the axial force of the piezoelectric element 42 when no voltage is applied to the piezoelectric element 42, and P21 is the axial force of the piezoelectric element 42 when a maximum voltage is applied to the piezoelectric element 42. In the present embodiment, since the friction material and the piezoelectric element are in a relationship of being configured in parallel, the force applied from the fastening means is distributed to the friction material and the piezoelectric element.
[0027]
Here, in the configuration of the damper of the present embodiment, since two piezoelectric elements 42 are provided for one tightening means, the following relationship is established (see FIG. 6). P0 = P1−P2 × 2
The friction coefficient between the friction material and the second member is represented by μ, and the friction coefficient is generated between the first friction material 121 (or the second friction material) and the second member 20 when no voltage is applied to the piezoelectric element. The frictional resistance F0 is expressed by the following equation.
F0 = μP0 = μ (P1−P20 × 2)
Next, when a maximum voltage is applied to the piezoelectric element and an axial force P21 acts on the piezoelectric element, friction generated between the first friction material 121 (or the second friction material 141) and the second member at this time. The resistance F1 is expressed by the following equation.
F1 = μP0 = μ (P1−P21 × 2)
However, P20 <P21. Therefore, the frictional resistance F0 when no voltage is applied to the piezoelectric element 42 is larger than the frictional resistance F1 when a voltage is applied to the piezoelectric element 42. When no voltage is applied to the piezoelectric element 42, the frictional resistance F0 has a maximum value. This is because, in the present embodiment, the piezoelectric element 42 is provided between the first friction plate 12 and the second friction plate 14. Therefore, when a voltage is applied to the piezoelectric element 42, a force is generated in a direction in which the first friction plate 12 and the second friction plate 14 are separated from each other, and the force by which the friction plate tightens the second member is reduced. The frictional resistance of the tire decreases. In other words, the relationship between the applied voltage and the frictional resistance is a downward-sloping graph.
[0028]
The setting method of the initial frictional resistance F0 (frictional force when the applied voltage is zero) in the present damper will be described. Even if the structure equipped with this damper is expected to receive a maximum earthquake and a power failure or failure of the frictional force adjustment mechanism occurs and it functions as a passive type damper (when the frictional force is fixed at F0), the structure The value of the initial frictional resistance F0 is set so as to obtain a friction damping force that does not cause significant damage to the object. In this way, even if a power failure or a failure occurs in the mechanism for adjusting the frictional force during a large earthquake, the necessary frictional resistance can be obtained, and the soundness of the structure can be maintained. At the time of a small or medium-sized earthquake, the frictional resistance of the damper is made smaller than the initial frictional force F0 by the frictional force adjusting mechanism to cause relative deformation in the damper portion and absorb vibration energy. In the event of a power failure or failure of the frictional force adjustment mechanism during a small or medium-sized earthquake, relative deformation does not occur in the damper part, and there is a possibility that vibration energy cannot be absorbed. No damage occurs.
[0029]
Instead of a damper configuration in which a piezoelectric element is provided between the first friction material 12 and the second friction material 14 as in the present embodiment, the friction material is pressed against the sliding plate by the piezoelectric element as shown in FIG. In the case of a damper that generates a force, the relationship between the applied voltage and the frictional resistance is a graph that rises to the right as shown in FIG. 7 (that is, the frictional resistance F1 when a voltage is applied to the piezoelectric element is larger than that of the piezoelectric element). Is larger than the frictional resistance force F0 when no voltage is applied to the first electrode). Here, even if a power failure or a failure occurs in the mechanism that increases the frictional force during a large earthquake, if the frictional resistance force F0 is set large so as not to damage the structure on which the damper is installed, the damper can be used during a small or medium-sized earthquake or strong wind. No relative deformation occurs in the part and vibration energy cannot be absorbed (damper does not work). Conversely, if the frictional resistance F0 is set to a small value so that the damper works during a small or medium-sized earthquake or a strong wind, the necessary frictional resistance will be reduced if a power failure occurs or a failure occurs in the mechanism that increases the frictional force during a large earthquake. Otherwise, damage to the structure may occur.
[0030]
According to the configuration of the damper of the present embodiment, the frictional resistance is maximized when no voltage is applied to the piezoelectric element (see FIG. 5). Therefore, even when a voltage cannot be applied to the piezoelectric element due to a power failure or the like, a necessary frictional resistance can be obtained.
[0031]
<Adjustment method>
A method of adjusting the damper according to the present embodiment will be described.
First, before performing this adjustment method, the damper 1 is configured as shown in FIGS. Thereby, in particular, the piezoelectric element 42 is configured to be located between the friction plate 12 and the friction plate 14 sandwiching the second member 20. The disc spring 36 is configured to be located between the bolt 32 and the first friction plate 12.
[0032]
Next, the tightening force of the tightening means 30 is adjusted. Specifically, the tightening force of the bolt 32 and the nut 34 is adjusted so that the disc spring 36A alone of the disc spring 36 is used in the above-described non-linear region R (see FIG. 4). Thereby, the disc spring 36 can apply a constant preload.
[0033]
Next, the adjusting means 40 is adjusted. More specifically, the adjustment screw 44 is adjusted so that the initial axial force acting on the piezoelectric element 42 is 0.4 × P21 to 0.6P21 (P21 is a piezoelectric element when a maximum voltage is applied to the piezoelectric element). The axial force acting on the element). The initial axial force acting on the piezoelectric element 42 is preferably about 0.45 × P21 to 0.55 × P21, and more preferably about half of the maximum generated force P21 (that is, when no voltage is applied to the piezoelectric element). The axial force P20 is about half of P21). Thereby, the piezoelectric element 42 can be contracted in advance with respect to the piezoelectric element 42, and a preload can be applied to the piezoelectric element 42 in advance. Since a preload is applied to the piezoelectric element 42 in advance, when a voltage is applied to the piezoelectric element 42, the piezoelectric element 42 generates a force in a direction to separate the first friction plate 12 and the second friction plate 14. I do.
[0034]
The adjustment of the adjustment screw 44 is performed based on the detection result of the voltage output from the piezoelectric element 42. That is, the piezoelectric element 42 outputs a voltage according to the applied force (in this case, the preload) by the piezoelectric effect of the piezo element. If the adjusting screw 44 is adjusted so that the voltage output from the piezoelectric element 42 becomes a predetermined value, the piezoelectric element 42 is in a state where a predetermined preload is applied. The adjustment of the adjustment screw 44 in the present embodiment is performed based on the output result of the load meter inserted in series with the adjustment screw 44 and the piezoelectric element 42 or the height measurement result of the piezoelectric element.
[0035]
FIG. 8 is an explanatory diagram of the adjusting means 40 of the present embodiment. A relay plate 46 is provided between the piezoelectric element 42 and the adjustment screw 44. The relay plate 46 is formed of a rectangular parallelepiped as shown in FIG. The second friction plate 14 has a rectangular hole 14H into which the relay plate 46 can be inserted. Since the relay plate 46 is fitted in the hole 14H, the rotation of the relay plate 46 can be suppressed even if the adjustment screw rotates for adjustment. Thereby, the twisting of the piezoelectric element 42 can be suppressed. Further, the tip of the adjusting screw 44 is tapered and thin as shown in FIG. Thus, transmission of the rotational force from the adjusting screw 44 to the relay plate 46 can be suppressed.
[0036]
In the damper 1 of the present embodiment, it can be considered that the preload from the disc spring 36 is distributed to the friction plate 12 (or the friction plate 14) and the piezoelectric element 42. As described above, the preload of the disc spring 36 becomes substantially constant even if the displacement between the first friction plate 12 and the second friction plate 14 fluctuates (see FIG. 4). On the other hand, if the generated force of the piezoelectric element 42 is controlled, the frictional resistance can be controlled, so that the vibration absorbing force of the damper can be controlled.
[0037]
=== Building using damper ===
<Structure>
FIG. 9 is an explanatory view of a building (frame of a building) 100 using the above damper. FIG. 10 is an explanatory diagram of the configuration of the damper unit 110 of FIG.
[0038]
In the figure, a building 100 mainly has a pillar 112, an upper beam 114A, and a lower beam 114B (note that 114B may be a floor). A brace 116A and a brace 116B are provided between the upper beam 114A and the lower beam 114B. The brace 116 has a function of reinforcing the frame, and acts on an axial force for suppressing relative vibration between the upper beam 114A and the lower beam 114B.
[0039]
During an earthquake, relative vibration between the upper beam 114A and the lower beam 114B becomes a problem. In the present embodiment, the vibration absorption characteristics of the damper unit 110 are controlled by controlling the voltage of the piezoelectric element 42 of the damper 1 used in the damper unit 110, and the vibration damping is widely performed from a large-scale earthquake to a small-scale earthquake. The effect can be obtained.
[0040]
Further, it is desirable that the damper unit used for the building obtain a necessary vibration damping effect even during a power outage. The damper unit 110 of the present embodiment can obtain a necessary frictional resistance even when no voltage is applied to the piezoelectric element 42, so that a necessary vibration damping effect can be obtained even during a power failure.
[0041]
<Sensor, control, etc.>
In FIG. 9, reference numeral 120 denotes a control system used for the damper unit of the present embodiment. The control system 120 has a controller 122, a vibration detector 124A and a vibration detector 124B.
[0042]
The controller 120 controls the damper unit 110 based on the detection values of the vibration detectors 124A and 124B. In particular, the controller 120 calculates data on the primary vibration mode based on the detection values of the vibration detectors 124A and 124B. Then, the frictional resistance of the damper unit 110 is controlled so as to suppress the primary vibration mode.
[0043]
The vibration detector 124A detects the acceleration of the upper beam 114A. The vibration detector 124B detects the acceleration of the lower beam 114B. Note that the vibration detector 114 may detect displacement or velocity.
[0044]
In this embodiment, even if the control system stops functioning due to a power failure or the like, the damper unit 110 can generate a necessary frictional resistance.
[0045]
=== About Other Embodiments ===
As described above, the damper and the like according to the present invention are described based on one embodiment. is not. The present invention can be changed and improved without departing from the spirit thereof, and it goes without saying that the present invention includes its equivalents. In particular, even the embodiments described below are included in the damper and the like according to the present invention.
[0046]
<About friction material>
In the above-described embodiment, since the friction material is provided on the friction plate, it is provided on the first member side. However, the position where the friction material is provided is not limited to this. For example, a friction material may be provided on the second member side.
[0047]
<About bolt 1>
In the above-described embodiment, the damper 1 uses a bolt and a nut for the fastening means 30. However, it is not limited to this. In short, any fastening means may be used as long as it can apply a preload to the first member so as to sandwich the second member.
[0048]
<About bolt 2>
In the above-described embodiment, the damper 1 has one fastening unit. However, the number of fastening means is not limited to this. For example, a plurality of tightening means may be provided for one damper.
[0049]
<About disc springs>
In the above-described embodiment, the damper 1 uses a disc spring for the fastening means 30. However, it is not limited to this. For example, any device that generates a repulsive force, such as a coil spring, may be used.
[0050]
<About piezoelectric elements>
In the above-described embodiment, the damper 1 uses the piezoelectric element of the adjusting means 40. However, it is not limited to this. For example, any actuator that generates a driving force, such as a hydraulic cylinder, may be used.
[0051]
<About the damper unit 1>
In the above-described embodiment, one damper unit 110 includes a plurality of dampers 1. However, it is not limited to this. For example, one damper unit may have only one damper.
[0052]
Further, in the above-described embodiment, the dampers 1 of the damper unit 110 individually include a friction material, a piezoelectric element, and the like. However, in the case where a plurality of dampers are provided, it is not necessary for the dampers to individually include components. For example, adjacent dampers may share a friction material, a piezoelectric element, or the like.
[0053]
<About the damper unit 2>
In the above-described embodiment, the damper unit 110 is provided between the brace joined to the upper beam and the brace joined to the lower beam. However, the position where the damper unit 110 is provided is not limited to this.
For example, as shown in FIG. 11, the damper unit 110 may be provided between the brace 116 and the upper beam 114A (or the lower beam 114B).
[0054]
<About the damper unit 3>
In the above-described embodiment, the damper unit is provided between the pair of braces and the upper beam (or the lower beam). However, the damper unit is not limited to the one provided via the brace.
For example, as shown in FIG. 12, it may be provided between the wall 117 and the upper beam 114A (or the lower beam 114B).
[0055]
<About the damper unit 4>
In the embodiment shown in FIGS. 11 and 12, one damper unit is provided for one set of braces or one wall. However, the number of damper units is not limited to this.
For example, as shown in FIG. 13, a plurality of damper units may be provided for one set of braces. Alternatively, for example, as shown in FIG. 14, a plurality of damper units may be provided for one wall.
[0056]
【The invention's effect】
According to the damper of the present invention, by controlling the frictional force of the damper, it is possible to effectively absorb the vibration energy of the structure regardless of the magnitude of the earthquake and to attenuate the vibration. Furthermore, even if the voltage or current supplied to the actuator is stopped during a large earthquake, a necessary damping force can be obtained by the initially set frictional force.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a damper according to the present embodiment.
FIG. 2 is a diagram when the damper of FIG. 1 is viewed from a side.
FIG. 3 is a sectional view of a disc spring alone.
FIG. 4 is a graph illustrating an example of a spring characteristic of a disc spring alone.
FIG. 5 is a graph showing the relationship between the voltage applied to the piezoelectric element and the frictional resistance of the damper (this embodiment).
FIG. 6 is an explanatory diagram of a force acting on a friction plate.
FIG. 7 is a graph showing a relationship between a voltage applied to a piezoelectric element and a frictional resistance of a damper in a reference example.
FIG. 8 is an explanatory diagram of an adjusting unit 40 of the present embodiment.
FIG. 9 is an explanatory diagram of a building (frame of a building) of the present embodiment.
FIG. 10 is an explanatory diagram of a configuration of a damper unit of the present embodiment.
FIG. 11 is an explanatory diagram of a damper unit according to another embodiment.
FIG. 12 is an explanatory diagram of a damper unit according to another embodiment.
FIG. 13 is an explanatory diagram of a damper unit according to another embodiment.
FIG. 14 is an explanatory view of a damper unit of another embodiment.
FIG. 15 is an explanatory diagram of a damper of a reference example.
[Explanation of symbols]
1 Damper
10 First member
12 First friction plate
121 1st friction material
14 Second friction plate
141 second friction material
20 Second member
30 Tightening means
32 volts
34 nuts
36 Belleville spring
36A Disc spring only
38 Washer
40 Adjusting means
42 Piezoelectric element
44 Adjustment screw
46 Relay board
100 building (framework of building)
110 damper unit
112 pillar
114A Upper beam
114B Lower beam (floor)
116 Brace

Claims (9)

A damper comprising a first member and a second member, wherein the damper attenuates relative vibration between the two members by using a frictional resistance force acting between the first member and the second member,
Means for applying a force such that the frictional resistance increases,
An actuator for generating a force so as to reduce the frictional resistance. The damper according to claim 1, wherein
The first member includes two plate members sandwiching the second member,
The actuator is provided between the two plate members. The damper according to claim 1 or 2,
The actuator generates a force using a piezoelectric effect. The damper according to claim 3, wherein
The means causes the actuator to contract through the first member. The damper according to claim 4, wherein
And adjusting means for adjusting a force in a direction for contracting the actuator. It is a damper according to any one of claims 1 to 5,
The frictional resistance when no voltage is applied to the actuator is greater than the frictional resistance when a voltage is applied to the actuator. The damper according to any one of claims 1 to 6,
The means applies a force to the first member using elastic deformation of a spring. The damper according to claim 7, wherein
The means applies a force to the first member using a non-linearly deforming spring. A structure comprising the damper according to claim 1.

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