JP2002070933A - Structure vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure vibration damping device that is applicable to a heavy structure. SOLUTION: The structure vibration damping device comprises a piezoelectric element 4 inserted between a vibration-controlled structure 1 and a fixed system to transform vibration energy of the vibration-controlled structure into electrical energy, a shunt circuit 6 made up of a resonance system including a resistor and a variable inductor to absorb the electrical energy transformed in the piezoelectric element, and an inductance value adjusting means 7 for adjusting the inductance value of the variable inductor of the shunt circuit 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure damping device for suppressing vibration of a heavy structure such as a mechanical structure or a building structure.

[0002]

2. Description of the Related Art Vibrations generated in a mechanical structure or a building structure not only hinder the function of the structure but also cause damage to the structure. Effective suppression is a key technology.

[0003] Vibration suppression techniques for suppressing vibration are roughly classified into active vibration suppression techniques and passive vibration suppression techniques.

[0004] The active vibration suppression technique is to suppress vibration by adding energy from the outside. As an example of the vibration suppression method, an actuator is installed on a structure and the actuator is driven so as to cancel the vibration. There is known a technique for suppressing the vibration by using the technique. This vibration damping method can be realized with a compact device, and excellent vibration damping effects can be expected. However, since additional energy needs to be added, cost reduction is an issue.

[0005] The passive vibration suppression technique suppresses vibration without adding extra energy from the outside. For example, a TMD (Tuned Mass Damper) vibration suppression method is known. As shown in the principle diagram of the TMD damping method in FIG.
In this vibration control method, a TMD 52 including an additional weight, a spring, and a damper is installed on a structure 51, and the operation thereof is intended to suppress vibration.

When the structure 51 generates vibration, the added weight also generates vibration using the vibration as a vibration generating force.
The vibration of the structure 51 can be suppressed (absorbed) by vibrating the additional weight largely by the action of the mechanical resonance system including the additional weight, the spring, and the damper that constitutes 2.
Therefore, in order to enhance the effect of suppressing vibration, the spring, the mechanical resonance frequency of the TMD 52 composed of each element is set to an appropriate value according to the natural frequency of the structure,
It is important to adjust the characteristics of the damper.

[0007] From a different point of view, this vibration damping principle is based on the structure 5
It can be considered that the vibration is suppressed because a part of the vibration energy of 1 is converted into the kinetic energy of the added weight and absorbed by the damper. This vibration damping method is highly reliable because the structure is simple and does not require complicated control. However, the larger the structure 51, the larger the mechanism of the TMD 52 for absorbing vibration. In addition, there is a disadvantage that it is not easy to adjust the spring and the damper so that the mechanical resonance frequency becomes a predetermined value.

As another passive vibration suppression method which solves such a drawback of the TMD method, a device comprising a piezoelectric element and a shunt circuit which is an electric circuit connected to the piezoelectric element is used.
There is a vibration suppression method called a Piezoelectric Shunt method (hereinafter, referred to as a piezoelectric shunt method). Regarding this damping method, see, for example, NW Hagood and A. von Flotow, “Damping of
Structural Vibrations with Piezoelectric Materials
and Passive Electrical Networks, ”Journal of Soun
d and Vibration, vol. 146, no. 2, pp. 245268, 1991.

The basic principle is that vibration energy of a structure is converted into electric energy by using a piezoelectric element, and the energy is efficiently absorbed by electric resistance in a shunt circuit which constitutes a resonance circuit, thereby suppressing vibration. The device can be made more compact than the TMD damping method, and the adjustment also changes the characteristics of the electric circuit, so that it can be performed more easily than the TMD method. .

FIG. 12 is a diagram showing a configuration principle of a vibration damping device using a piezoelectric shunt method.

The present vibration damping device comprises a piezoelectric element 53 and a shunt circuit 54 electrically connected to the piezoelectric element 53. The shunt circuit 54 has a coil 55 and an electric resistor 56 connected in series.

A piezoelectric element is an element capable of mutually converting mechanical energy and electric energy. When a pressure (strain) is applied to a piezoelectric element, a voltage is generated (piezoelectric effect).
Conversely, when a voltage is applied to the piezoelectric element, distortion occurs (piezo-inverse piezoelectric effect).

In FIG. 12, a pressure 57 is applied to the piezoelectric element 53.
Is applied, a voltage is generated by the piezoelectric effect. At this time, since an LCR resonance circuit is formed by the inherent capacitance 58, the coil 55, and the electric resistance 56 held by the piezoelectric element 53, a large resonance current 59 is obtained by appropriately adjusting the electric resonance frequency by the coil 56 or the resistance 57. Can be taken out.

JP-A-7-49388, JP-A-10-28
7127 discloses a vibration damping method using the piezoelectric shunt method. In any of these vibration suppression techniques, a thin sheet-like piezoelectric element is attached to a structure, and a bending moment acts on the piezoelectric element with respect to vibration of the structure.

[0015]

However, the practical application of the vibration damping technology by the piezoelectric shunt method is limited to relatively light structures such as skis and snowboards, and the weight of production machinery and equipment and buildings is reduced. Examples applied to structures are not yet known.

In the first place, the electromechanical coupling coefficient, which is the characteristic of a piezoelectric element, is the same value both when converting mechanical (vibration) energy to electrical energy and when converting electrical energy to mechanical (vibration) energy. Unless a piezoelectric element capable of generating the same level of vibration as that described above is used, the effect of converting the vibration energy of the structure into electric energy and absorbing it cannot be expected. Therefore, in a configuration in which a thin sheet-like piezoelectric element as used in the related art is attached to a structure, when the weight of the structure is large,
Since vibration at the same level as vibration to be suppressed due to insufficient power of the piezoelectric element cannot be generated, a vibration damping effect cannot be expected.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a structure damping device which can be widely applied to heavy structures.

[0018]

According to the present invention, there is provided a structure damping device comprising a piezoelectric element mounted on a structure to be damped and a shunt circuit connected to the piezoelectric element. It is a structure damping device inserted between a vibration target structure and a fixed system.

According to the present invention, there is provided a structure damping device comprising a piezoelectric element mounted on a structure to be damped and a shunt circuit connected to the piezoelectric element, wherein the piezoelectric element is a first structure to be damped. And a structure damping device inserted between the second damping target structure and the second damping target structure.

According to the present invention, there is provided a resonance device including a piezoelectric element inserted between a structure to be damped and a fixed system for converting vibration energy of the structure to be damped into electric energy, and a resistor and a variable inductor. A structure damping device comprising: a shunt circuit configured to absorb the electric energy converted by the piezoelectric element; and an inductance value adjusting unit configured to adjust an inductance value of a variable inductor of the shunt circuit.

According to the present invention, there is provided a piezoelectric element inserted between a first damping target structure and a second damping target structure for converting vibration energy of the damping target structure into electric energy. A shunt circuit configured by a resonance system including a resistor and a variable inductor to absorb the electric energy converted by the piezoelectric element; and an inductance value adjusting unit for adjusting an inductance value of the variable inductor of the shunt circuit. It is a structure damping device.

Further, according to the present invention, in the structural vibration damping device according to the above invention, the inductance value adjusting means adjusts a main frequency of an electric signal output from the piezoelectric element in a state where the shunt circuit is separated from the piezoelectric element. Detect
A structure damping device comprising: a tuning amount calculating unit that calculates an optimum inductance value of the variable inductor from the frequency; and a tuning control unit that adjusts the variable inductor by using the calculated inductance value as a target value.

According to the present invention, there is provided the structural vibration damping device according to the above invention, wherein the piezoelectric element has a plurality of piezoelectric elements connected in parallel.

Further, the present invention is the structure damping device according to the above invention, wherein the variable inductor is constituted by a plurality of operational amplifiers, a plurality of resistors and a capacitor.

Further, the present invention is the structural vibration damping device according to the above invention, wherein the piezoelectric element is a laminated piezoelectric element.

[0026]

FIG. 1 is a block diagram showing an embodiment of a structure vibration damping device according to the present invention.

In FIG. 1, a structure 1 in which vibration is to be suppressed is shown.
Is a structure loaded on the gantry 2 provided on the fixed foundation 3. A piezoelectric element 4 and a spacer 5 are incorporated between the structure 1 and the fixed foundation 3 so that the piezoelectric element 4 receives a compressive force by the structure 1. Here, the spacer 5
Is a jack, for example, and functions to hold and fix the piezoelectric element 4 by applying pressure (initial compressive force) to the piezoelectric element 4 and the structure 1.

In order to suppress the vibration of the heavy structure having the above-described structure, the vibration damping device according to the present embodiment uses the piezoelectric element 4 and the electric energy generated by the piezoelectric element to efficiently use the resonance circuit. A shunt circuit 6 that functions to enhance the take-out vibration suppression effect and a tuning device 7 that adjusts the shunt circuit 6 so that the vibration suppression function operates in an optimal state are provided.

The tuning device 7 calculates the inductance of the shunt circuit 6 to be adjusted from the processed signal by reading the vibration waveform of the structure 1 through the switch 8 and processing the vibration signal. And a tuning control unit 7c for adjusting the shunt circuit 6 so as to obtain the inductance.

Next, the operation of the present apparatus will be described with reference to the drawings.

In this embodiment, the piezoelectric element 4 is inserted between the structure 1 to be damped and a fixed system such as the fixed foundation 3 so that a compressive force acts thereon. By adopting a configuration in which the element is inserted between the structures, it is possible to use a laminated piezoelectric element that can generate a larger excitation force than a sheet-shaped piezoelectric element.

The laminated piezoelectric element has a structure in which a plurality of piezoelectric ceramic elements are stacked, and an actuator for active vibration damping utilizing the property of generating a strain amplified in the laminating direction by applying a voltage. It is used as At present, some laminated piezoelectric elements which are available as standard are capable of generating a load of about several tons by one. Therefore, it is a "piezoelectric element capable of generating the same level of vibration (displacement) as the vibration (displacement) to be suppressed" which is a condition applicable to the above-described vibration control of a heavy structure.

FIG. 2 is a diagram schematically showing a force acting on the piezoelectric element 4 when vibration occurs in the up-down direction of the structure 1 in the vibration damping device of the present embodiment. When the structure 1 vibrates, the piezoelectric element 4 conceptually exerts a compressive force and a tensile force. However, since the initial compressive force is applied to the piezoelectric element 4 by the spacer 5, the force acting on the piezoelectric element 4 Is only the compression force that fluctuates around the initial compression force.
Therefore, the output voltage of the piezoelectric element 4 generates an AC voltage that changes with the oscillation cycle of the structure 1 with the state where the initial compressive force is applied as a reference (voltage = 0).

The generated AC voltage is input to a shunt circuit 6 connected to the piezoelectric element 4. The shunt circuit 6 is basically a resonance circuit composed of an inductor (inductance L) and a resistance (resistance value R). To effectively suppress vibration, L and R constituting the circuit of the shunt circuit are used.
The natural frequency of the heavy structure 1 for which the value of
An appropriate value must be set according to various parameters such as the capacitance C of the piezoelectric element 4.

The optimal values of L and R can be found in the literature (NWHagood
and A. von Flotow, ”Damping of Structural Vibratio
ns with Piezoelectric Materials and Passive Electr
icalNetworks, ”Journal of Sound and Vibration, vol.
146, no. 2, pp. 245268, 1991), and the optimum inductance Lopt and the optimum resistance Ropt for the primary mode vibration are given by Expressions (1) and (2).

[0036]

(Equation 1)

However, the values represented by the equations (1) and (2) are theoretically derived. For example, the rigidity of the structure differs between the experimental facility and the actual facility. Further, even in the same actual equipment, for example, the parameter has a different value during high-load operation and during low-load operation.
Therefore, in order to effectively suppress the generated vibration, it is necessary to adjust (tune) the circuit constant of the shunt circuit every time the vibration is generated.

In the present embodiment, the tuning is performed by changing the inductance L of the shunt circuit 6. The reason is as follows.

In order for the generated vibration energy to be efficiently absorbed and to exhibit the vibration damping effect, it is necessary that the frequency of the generated vibration matches the resonance frequency of the resonance circuit forming the shunt circuit 6. Now, assuming that the shunt circuit 6 is a resonance circuit including the inductance L, the resistance value R, and the capacitance C of the piezoelectric element 4, the resonance frequency f is inversely proportional to the square root of L × C. Therefore, f can be changed by changing C or L, but C is a unique value of the piezoelectric element, and it is difficult to change the value. Therefore, the resonance frequency f is adjusted by changing the inductance L.

FIG. 3 is a diagram showing a configuration example of the variable inductor.

In general, since the resonance frequency of a heavy structure is relatively low, a shunt circuit suitable for a heavy structure requires the use of a variable inductor having a large L. The variable inductor of the present system satisfies this condition, and its principle is to change the inductance by moving the core 11 in the coil 10.

FIG. 4 is a diagram showing another example of the configuration of the variable inductor.

The inductor of this system is composed of an operational amplifier 12a,
12b, an active circuit composed of the resistors R1, R2, R3, R5, and the capacitor Cv. The inductance Lv of the inductor used in this circuit is represented by Expression (3). Therefore, the inductance can be changed by changing the resistance value.

Lv = R1, R3, R3, Cv / R2 (3) In this method, since the inductance value can be adjusted by changing the resistance value, a large coil is not required as compared with the above method. Also, there is no need for a mechanism to move the core,
It can be configured as a compact device.

Next, the operation of the tuning device 7 will be described with reference to FIG.

When vibration occurs in the structure 1, an electromotive force is generated in the piezoelectric element 4. When the vibration is large, that is, when the generated electromotive force is equal to or more than a predetermined value, the tuning device 7 starts operating. First, in a state where the shunt circuit is disconnected by the switch 8, the vibration signal input unit 7a reads an electric signal output from the piezoelectric element. At that time, the electric signal is read at a period corresponding to the resonance frequency of the target structure so that the vibration waveform can be reproduced. Subsequently, the tuning amount calculation unit 7b is activated and performs frequency conversion based on the read vibration signal to obtain a frequency distribution of the vibration.

FIG. 5 is a diagram showing the frequency distribution of the generated vibration.

In the figure, the graph shown by the solid line is the distribution obtained by the frequency conversion processing, and it can be seen from this distribution that the main frequency of the vibration is f1. On the other hand, the graph shown by the dotted line is the distribution of vibration obtained in advance in experimental facilities and the like, and from this distribution, the main frequency of vibration is f
It turns out that it is 0. Therefore, the shunt circuit 6 is adjusted so as to operate properly when a vibration having a vibration frequency of f0 occurs. In this state, the vibration suppression effect cannot be sufficiently exerted, and tuning is required.

The tuning calculator 7b calculates the frequency (f0−Δf) based on the frequency distribution after the frequency conversion.
A frequency that gives the maximum value in the range of (f0 + Δf) is obtained, and that value is set as a main frequency f1 of the generated vibration. Here, if | f0−f1 | is smaller than a predetermined value, it is determined that the adjustment of the shunt circuit 6 is normal, and no tuning operation is performed. If | f0−f1 | is larger than a predetermined value, the shunt circuit is not. It is determined that readjustment of step 6 is necessary, and an inductance value to be tuned is calculated.

Assuming that the inductance giving the resonance frequency f0 is L0 and the inductance giving the resonance frequency f1 is L1, the resonance frequency f of the resonance circuit constituted by the shunt circuit 6 is inversely proportional to the square root of L × C. L1 is represented by equation (4).

L1 = L0 × (f0 / f1) ² (4) The tuning controller 7c controls the variable inductor of the shunt circuit 6 using the inductance L1 calculated in the above procedure as a control target value. As a control method, either PID control or preset control may be used, and the tuning device 7 may be configured to periodically repeat the above-described processing to perform control.

After the inductance value is tuned to a desired value, the switch 8 is switched to switch the piezoelectric element 4.
By connecting the shunt circuit 6 and the vibration control device, the vibration is suppressed.

FIG. 6 is a diagram showing the vibration damping effect of the vibration damping device according to the present embodiment.

In this figure, the vibration displacement is large because the operation of the shunt circuit 6 of the vibration damping device is stopped for Ts seconds after the occurrence of the vibration, but the vibration becomes large after Ts seconds when the operation of the shunt circuit 6 is started. It can be seen that is well suppressed.

The sheet-like piezoelectric element was affixed to the same structure to attempt vibration damping, but little effect was observed. This is considered to be due to insufficient power because the structure could not be sufficiently vibrated even when the sheet-shaped piezoelectric element used was used as an actuator.

From this, it can be seen that it is necessary to adopt a type and installation method of the piezoelectric element which can generate a sufficient vibration to the target structure when the piezoelectric element is operated as an actuator. It is considered to be a condition for obtaining

Next, examples in which the vibration damping device according to the present invention is applied to various structures will be described.

FIG. 7 shows an example of the configuration of a vibration damping device applied to a machine tool such as a grinder.

A carriage 22 is set on the fixed base 23, and a grindstone base 21 is mounted on the setting base 22 so as to be movable back and forth. A rotating grindstone 24 is attached to the tip of the grindstone table 21. For example, the rotating grindstone 24 is pressed against a rotating roll 25 to polish the roll surface.

In a machine tool such as a grinder constructed as described above, if vibration occurs due to mechanical system resonance or the like, a mark due to the vibration may be transferred to the target roll 25 or the like.

In this configuration example, a shunt circuit in which a laminated piezoelectric element 26 having a spacer 27 is inserted between the grindstone base 21 and the fixed base 23 and the circuit constant is adjusted so as to absorb the resonance frequency of the mechanical system. 28 is used to prevent the occurrence of vibration.

FIG. 8 shows a structural example of a vibration damping device applied to a rolling mill.

The rolling mill includes an upper roll chock 32a and a lower roll chock 32a in a structure called a housing (not shown).
The rolling material 30 is rolled by applying a rolling load to the upper roll chock 32a and the lower roll chock 32a by hydraulic pressure or the like, and transmitting the rolling load to the upper roll 31a and the lower roll 31a. It is configured as follows.

In the rolling mill configured as described above, when a specific condition is satisfied during the rolling operation, the roll vibrates, and resonates with the natural frequency of the housing to generate vibration called chattering. is there.

In this configuration example, the laminated piezoelectric element 33a,
33b is inserted between the upper and lower roll chocks. In this configuration example, both roll chocks vibrate, but since these structures act as a vibration source for transmitting the vibration of the roll to the housing, the vibration of these structures is suppressed using a piezoelectric element. Thereby, chattering vibration can be reduced.

As in this example, the effect of vibration reduction can be obtained not only when the piezoelectric element is inserted between the damping target structure and the fixed object but also between the damping target structures. It is possible to get.

FIG. 9 is a diagram showing an application example of a vibration damping device applied to a building structure.

In order to reduce the shaking generated in a building structure such as a building due to a wind, an earthquake, or the like, in this application example, a plurality of stacked molds are provided between a reaction force member 41 provided on a building member 40 and a fixed foundation 45. The piezoelectric elements 42a and 42b are inserted, and the vibration is reduced by a shunt circuit 43 installed near the piezoelectric elements 42a and 42b.

FIG. 10 is an enlarged view showing the installation portions of the piezoelectric elements 42a and 42b.

An initial compressive force is applied to each piezoelectric element by spacers 44a and 44b, and each piezoelectric element 42a and 42b
b are connected in parallel and input to the shunt circuit 43.

As described above, when configuring the resonance circuit of the shunt circuit 43 for an object having a relatively low resonance frequency such as when the structure vibrates, L ×
To increase C, that is, a large L or large C is required for the circuit.

In general, as the inductance L increases, the outer dimensions of the coil also increase accordingly, resulting in an increase in the size of the device and an increase in cost. On the other hand, increasing the capacitance C means increasing the specific capacitance of the piezoelectric element in the configuration of the present shunt circuit.
It can be easily realized by connecting a plurality of 2b in parallel.

Therefore, the configuration in which the piezoelectric elements 42a and 42b are connected in parallel has a great effect on cost reduction without increasing the size of the device. Further, the parallel input of the piezoelectric elements means that the plurality of piezoelectric elements 42a, 42a
b, the structure 40 can be shared and supported.
Since the load applied to one piezoelectric element is reduced, it is not necessary to use a piezoelectric element having a specification and structure with a large load resistance, which can lead to a reduction in the cost of the vibration damping device.

The connection with the shunt circuit 43 shown in FIG. 10 is an example in which the loads acting on the piezoelectric elements 42a and 42b are in the same phase. A similar effect can be obtained by connecting the shunt circuit with the output of the piezoelectric element reversed.

[0075]

As described above, various effects are produced according to the present invention.

In the present invention, since the piezoelectric element is inserted between the structure and the fixed object or between the structures, it is difficult to apply the vibration damping technology using the piezoelectric element. Applicable to structures.

Since the present invention includes the tuning circuit for changing the inductance of the shunt circuit, the vibration control function can always be properly performed.

In the vibration damping device according to the present invention, since a plurality of piezoelectric elements are connected in parallel, a compact device structure can be obtained.

In the vibration damping device according to the present invention, since the vibration damping device is configured using the variable inductor formed by the active circuit, a compact device configuration can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a structure vibration damping device according to the present invention.

FIG. 2 is a diagram showing a force acting on a piezoelectric element in the embodiment of the structural vibration damping device according to the present invention.

FIG. 3 is a diagram showing a configuration example of a variable inductor.

FIG. 4 is a diagram showing a configuration example of a variable inductor.

FIG. 5 is a diagram showing a frequency distribution of generated vibration.

FIG. 6 is a diagram showing a vibration damping effect according to the embodiment of the structure vibration damping device according to the present invention.

FIG. 7 is a diagram showing a configuration of a vibration damping device applied to a machine tool.

FIG. 8 is a diagram showing a configuration of a vibration damping device applied to a rolling mill.

FIG. 9 is a diagram showing a configuration of a vibration damping device applied to a building structure.

FIG. 10 is an enlarged view of an installation part of a piezoelectric element of a vibration damping device applied to a building structure.

FIG. 11 is a diagram showing the principle of the TMD vibration suppression method.

FIG. 12 is a diagram showing the principle of a vibration damping device using a piezoelectric shunt method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Structure 3 ... Fixed foundation 4 ... Piezoelectric element 5 ... Spacer 6 ... Shunt circuit 7 ... Tuning device 7a ... Vibration signal input part 7b ... Tuning amount calculation part 7c ... Tuning control part 8 ... Switching device 10 ... Coil 11 ... Core 12a ... operational amplifier 12b ... operational amplifier 32a ... upper roll chock 32b ... lower roll chock 51 ... structure 52 ... TMD 53 ... piezoelectric element 54 ... shunt circuit 55 ... coil 56 ... resistance 57 ... pressure 58 ... intrinsic capacitance 59 ... resonance current

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kouhei Ishida 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. 3J048 AA07 AB07 BG10 CB21 DA01 EA07 EA38

Claims (8)

[Claims] 1. A structure vibration damping device comprising a piezoelectric element mounted on a structure to be damped and a shunt circuit connected to the piezoelectric element, wherein the piezoelectric element comprises a structure for fixing the structure to be damped and a fixed system. A structure damping device inserted between the two. 2. A structure damping device comprising a piezoelectric element mounted on a structure to be damped and a shunt circuit connected to the piezoelectric element, wherein the piezoelectric element has a first structure to be damped and a shunt circuit. A structure damping device inserted between the damping target structure and the damping target structure. 3. A piezoelectric element inserted between a structure to be damped and a fixed system for converting vibration energy of the structure to be damped into electric energy, and a resonance system including a resistor and a variable inductor. And a shunt circuit for absorbing the electric energy converted by the piezoelectric element, and an inductance value adjusting means for adjusting an inductance value of a variable inductor of the shunt circuit. 4. A piezoelectric element inserted between a first damping target structure and a second damping target structure for converting vibration energy of the damping target structure into electric energy; A shunt circuit configured with a resonance system including a variable inductor and absorbing the electric energy converted by the piezoelectric element, and an inductance value adjusting unit configured to adjust an inductance value of the variable inductor of the shunt circuit. Structure damping device. 5. The structure vibration damping device according to claim 3, wherein the inductance value adjusting unit adjusts a main frequency of an electric signal output from the piezoelectric element in a state where the shunt circuit is separated from the piezoelectric element. A tuning amount calculating unit that detects and calculates an optimum inductance value of the variable inductor from the frequency, and a tuning control unit that adjusts the variable inductor with the calculated inductance value as a target value. Object damping device. 6. The structure vibration damping device according to claim 3, wherein the piezoelectric element is configured by connecting a plurality of piezoelectric elements in parallel. Damping device. 7. The structure vibration damping device according to claim 3, wherein the variable inductor includes a plurality of operational amplifiers, a plurality of resistors, and a capacitor. Structure damping device. 8. The structure vibration damping device according to claim 1, wherein the piezoelectric element is a laminated piezoelectric element.