JP2654525B2 - Converter using magnetostrictive electrostrictive mutual conversion element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter using a magnetostrictive electrostrictive mutual conversion element which can be used for a voltage controllable variable inductance, a current transformer, a modulator, a filter, a stress sensor capable of outputting both voltage and current, and the like. Things.

[0002]

2. Description of the Related Art Conventionally, a winding transformer or an active element is generally used to perform voltage / current conversion. However, in the above-mentioned winding transformer, a high-frequency loss is large, so there is a limit in a frequency band. Further, when the above-mentioned active element is used, a circuit becomes complicated and a power supply for driving this is required. An object of the present invention is to provide a converter using a magnetostrictive electrostrictive mutual conversion element which can solve the above-mentioned conventional problems by integrating the magnetostrictive element and the electrostrictive element.

[0003]

Means for Solving the Problems In order to achieve the above object, the present invention provides an electrostrictive element and an electrostrictive element integrated with the electrostrictive element so as to exhibit a mutual effect of the electrostrictive effect and the magnetostrictive effect. forming a magnetostrictive element which expands and contracts in a magnetostrictive electrostrictive interconversion element is passive element, the voltage current and input means for supplying an input signal to the electrostrictive element, and output means for extracting an output signal from the magnetostrictive element A conversion device is configured. Further, with the above-described magnetostrictive electrostrictive interconversion element, a first output means for taking out an output signal from the electrostrictive element, and a second output means for extracting an output signal from the magnetostrictive element, the said electrostrictive element, A mechanical-electrical conversion device is provided by providing a displacement applying unit to which a mechanical displacement is added from the outside.

[0004]

The voltage-to-current converter according to the present invention has a magnetostrictive electrostrictive
An input signal is given to the electrostrictive element of the conversion element, and the magnetostrictive element is provided.
The output signal is extracted from the
There is no limit to the wavenumber band,
Neither input nor output circuits are required. In the magnetostrictive electrostrictive mutual conversion element, when a distortion is generated in the electrostrictive element, the magnetostrictive element expands and contracts integrally with the electrostrictive element, and its magnetic characteristics change. Conversely, when strain is generated in the magnetostrictive element, the electrostrictive element expands and contracts integrally with the magnetostrictive element, and the electrical characteristics of the electrostrictive element change. That is, as a result of the electrostrictive element and the magnetostrictive element expanding and contracting integrally, the electrostrictive effect and the magnetostrictive effect mutually affect each other. Therefore, an input can be given to one of the electrostrictive element or the magnetostrictive element and an output corresponding to the level of the input can be taken out from the other, and a distortion can be generated by adding a mechanical displacement to the electrostrictive element, Various applications are possible, such as a voltage signal and a current signal corresponding to the displacement can be extracted from each of the electrostrictive element and the magnetostrictive element. Moreover, the structure is extremely simple and compact.

Also, in the electromechanical transducer of the present invention, when a displacement is added to the electrostrictive element from the outside, a voltage output signal whose level changes according to the displacement is output from the electrostrictive element, and a current output signal is magnetostricted. Since it is possible to take out each element from the element, for example, it is possible to bond the electrostrictive element to the member to be measured, detect the stress generated in the member to be measured, and output the detection signal as both voltage and current. is there.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a voltage-current converter according to the present invention and
An example of the magnetostrictive electrostrictive mutual conversion element used for the electromechanical conversion device will be described. FIG. 1 shows an example of a magnetostrictive electrostrictive interconversion element 1, in which Fe ₇₈ Si ₁₀ B ₁₂ (magnetostriction constant 40 × 10 ⁻⁶⁾ The magnetostrictive element 3 made of an amorphous magnetic film (magnetostriction constant: 15 × 10 ⁻⁶ ) is formed by a high-frequency sputtering method using a target material having a composition of (1). Thus, the electrostrictive element 2 and the magnetostrictive element 3 are integrally connected, and therefore, the electrostrictive element 2 and the magnetostrictive element 3 expand and contract integrally in the plane direction 5.

[0007] The polarization direction P of the electrostrictive element 2 is set upward or downward. Therefore, when a voltage is applied to the electrostrictive element 2 in the polarization direction P, the elongation occurs in that direction, while the electrostriction element 2 contracts in the plane direction 5 of the electrostriction element 2, and when a voltage is applied in the opposite direction to the polarization direction P, , While contraction occurs in that direction, while elongation occurs in the plane direction 5 of the electrostrictive element 2. On the other hand, when a magnetic field is applied to the magnetostrictive element 3, the magnetostrictive element 3 extends in the direction of the magnetic flux according to the magnetic flux density. Even if the magnetic flux is reversed, the magnetostrictive element 3 does not shrink, but also expands according to the magnetic flux density.

FIG. 2 shows another example of the magnetostrictive electrostrictive interconversion element 1. The electrostriction element 2 has a polarization direction P along the longitudinal direction 7, and the magnetostriction An element 3 is formed. The electrostrictive element 2 has a large number of polarization unit regions 8 divided in the longitudinal direction 7, and the adjacent regions 8, 8 have polarization directions P opposite to each other. Therefore,
When a voltage is applied in the polarization direction P for each region 8 of the electrostrictive element 2, the electrostrictive element 2 expands in the longitudinal direction 7 and contracts in the longitudinal direction 7 when a voltage is applied in the opposite direction to the polarization direction P. .

In the magnetostrictive electrostrictive mutual conversion element 1 shown in FIGS. 1 and 2, when a distortion is generated in the electrostrictive element 2,
The magnetostrictive element 3 expands and contracts integrally with the electrostrictive element 2, and its magnetic characteristics change. Conversely, when strain is generated in the magnetostrictive element 3, the electrostrictive element 2 expands and contracts integrally with the magnetostrictive element 3, and the electrical characteristics of the electrostrictive element 2 change. That is,
As a result of the electrostrictive element 2 and the magnetostrictive element 3 expanding and contracting integrally, a mutual effect in which the electrostrictive effect and the magnetostrictive effect mutually influence is obtained.

Therefore, for example, as shown in FIG. 3 showing an application mode of the magnetostrictive electrostrictive mutual conversion element 1 shown in FIG.
An electrode film 6 is formed on the lower surface of the device, lead wires 11 and 12 are connected to the magnetostrictive element 3 and the electrode film 6, and the magnetostrictive element 3
A coil 20 for excitation is arranged on the outer periphery of the magnetostrictive electrostrictive mutual conversion element 1 so as to enclose the lead wires 11 and 12.
When the electrostrictive element 2 is expanded and contracted by applying an input voltage to the electrostrictive element 2 through the element, the magnetostrictive element 3 also expands and contracts integrally with the electrostrictive element 2, thereby increasing or decreasing the magnetic permeability of the magnetostrictive element 3. Then, since the inductance of the coil 20 changes,
From the coil 20, an output corresponding to the input voltage can be taken out. This can be used for a voltage-current converter described later.

Contrary to this, when the magnetostrictive element 3 is expanded by supplying an input current to the coil 20 shown in FIG. 3, the electrostrictive element 2 is also expanded integrally with the magnetostrictive element 3, and the Since the voltage at both ends of the distortion element 2 changes, an output corresponding to the input current can be taken out from the lead wires 11 and 12. This can be used for a current-to-voltage converter described later.

Also, for example, by fixing the electrostrictive element 2 to a member that causes mechanical displacement,
, A voltage signal and a current signal corresponding to the displacement can be extracted from each of the electrostrictive element 2 and the magnetostrictive element 3. This can be used for a stress sensor capable of outputting both voltage and current, which will be described later.

Next, the results of actual measurement of the magnetostriction effect on the applied voltage as a change in the magnetic permeability using the magnetostrictive electrostrictive mutual conversion element of FIG. 1 will be described. FIG. 4 shows the apparatus used for the actual measurement. 4, the magnetostrictive electrostrictive mutual conversion element 1 and the lead wires 11 and 12 are the same as those shown in FIG. The exciting coils 20 are arranged near both ends in the longitudinal direction 7 of the magnetostrictive electrostrictive mutual conversion element 1. The electrostrictive element 2 and the magnetostrictive element 3 of the magnetostrictive electrostrictive mutual conversion element 1 are manufactured by the same method using the same material as described with reference to FIG. 1, and the electrode film 6 is made of gold. Electrostrictive element 2
Has a length of 15 mm, a width of 8 mm, and a thickness of 0.6 mm,
The magnetostrictive element 3 has a length of 9 mm, a width of 8 mm, and a thickness of 1 μm. The electrode film 6 has a length of 9 mm and a width of 8 mm.

A voltage is applied to the electrostrictive element 2 from a DC variable voltage source 13 via lead wires 11 and 12, and an AC current is supplied from an AC power supply 14 to an exciting coil 20. Further, on the upper surface of the magnetostrictive element 3, a figure-of-eight detection coil 15 is formed.
Is connected to a detector 16 for detecting the voltage change.

In the actual measurement, a voltage in the range of -400 V to +400 V is applied from the DC variable voltage source 13 to the electrostrictive element 2, while the AC power supply 14 supplies a current to the exciting coil 20 to supply 10 mOe. (MO
A magnetic field having a frequency of 1 MHz, 2 MHz, 5 MHz, or 10 MHz was applied to the magnetostrictive element 3 with the strength of e). In this state,
A voltage change generated in the detection coil 15 was detected by the detector 16, and the relative magnetic permeability μ was calculated from the detected voltage value. The result is shown in FIG. The amount of magnetostriction of the magnetostrictive element 3 caused by the AC magnetic field of 10 mOe is negligible compared to the amount of expansion and contraction of the magnetostrictive element 3 caused by the electrostriction of the electrostrictive element 2. From FIG. 5, it was confirmed that the relative magnetic permeability μ increased or decreased according to the magnitude of the applied voltage at any frequency. Note that the vertical axis on the right side of FIG. 5 shows a value normalized by setting the inductance to 1 when the relative magnetic permeability μ is 100.

Next, a method for wiring the electrostrictive element 2 in the magnetostrictive electrostrictive mutual conversion element 1 will be described. FIG.
Is the electrostrictive element 2 in the magnetostrictive electrostrictive mutual conversion element 1 of FIG.
This shows the method of wiring to the magnetostrictive element 2, wherein the magnetostrictive element 3 formed on the upper surface of the electrostrictive element 2 is also used as one electrode of the electrostrictive element 2, and the first lead wire 11 is connected to the upper surface of the magnetostrictive element 3. I do. An electrode film 6 made of gold is formed on the lower surface of the electrostrictive element 2 by a sputtering method. Instead of this electrode film 6, a magnetostrictive element may be formed and used as an electrode. A second lead wire 12 is connected to the electrode film 6 constituting the other electrode, and input or output to the electrostrictive element 2 is performed via the lead wires 11 and 12. In this wiring method, both electrodes 3 and 6 and lead wires 11 and 12 constitute input means or output means.

For example, when a voltage is input from the lead wires 11 and 12 to the electrostrictive element 2 via the electrodes 3 and 6, the thickness of the electrostrictive element 2 changes according to the level of the applied voltage. To expand and contract in the plane direction 5.

FIG. 7 shows a method of wiring to the electrostrictive element 2 in the magnetostrictive electrostrictive mutual conversion element 1 of FIG.
As shown in (a), first and second electrodes 22 and 23 arranged in a comb shape are formed on the upper surface of the electrostrictive element 2. As shown in FIG. 7B, these electrodes 22 and 23 are alternately located at the boundaries between the polarization unit regions 8 of the electrostrictive element 2. In FIG. 7A, a first lead wire 11 is derived from a first electrode 22 and a second lead wire 12 is derived from a second electrode 23. These lead wires 11, 12 and both electrodes 22, Input or output to the electrostrictive element 2 is performed via 23 (input means or output means).

For example, when a voltage is input to the electrostrictive element 2 via the lead wires 11 and 12 and the two electrodes 22 and 23, when the first electrode 22 is positive and the second electrode 23 is negative, FIG. Since a voltage is applied in the polarization direction P of the electrostrictive element 2 in (b), the electrostrictive element 2 extends in the longitudinal direction 7.
Conversely, when the first electrode 22 is negative and the second electrode 23 is positive, a voltage is applied in a direction opposite to the polarization direction P of the electrostrictive element 2, so that the electrostrictive element 2 contracts in the longitudinal direction 7. .

On the other hand, a wiring method for the magnetostrictive element 3 in the magnetostrictive electrostrictive mutual conversion element 1 is as follows. Normally, since the magnetostrictive element 3 is extremely thin, it is difficult to use magnetostriction in a direction (vertical direction in FIG. 1) orthogonal to the plane direction 5 like the electrostrictive element 2 shown in FIG. Only the magnetostriction along the plane direction 5 is used. This is shown in FIGS.

In FIG. 8, so as to enclose the magnetostrictive element 3,
An exciting coil 20 is arranged on the outer periphery of the magnetostrictive electrostrictive mutual conversion element 1, and input or output to the magnetostrictive element 3 is performed via the coil 20 and leads 25 and 26 derived therefrom. In this wiring method, the coil 20 and the lead wires 25 and 26 constitute input means or output means. For example, when a current is input to the coil 20, a magnetic flux H is generated in the longitudinal direction 7 of the magnetostrictive element 3, and regardless of the reversal of the magnetic flux H, the magnetostrictive element 3 is moved in the longitudinal direction 7 by an amount corresponding to the magnetic flux density. Stretches.

In FIG. 9, a folded conductive wire 29 is formed on the upper surface of the magnetostrictive element 3 with an insulating layer 28 interposed therebetween, and through first and second lead wires 25 and 26 derived from the folded conductive wire 29. Then, input or output to the magnetostrictive element 3 is performed. In this wiring method, the lead 1
1, 12 and the folded conductor 29 constitute input means or output means. For example, both lead wires 11 and 12
When a current is input to the folded conductive wire 29 through the wire, as shown in FIG. 10, currents flow in mutually opposite directions between the adjacent conductive wires 29, so that the magnetostrictive element 3 has opposite currents along the longitudinal direction 7 thereof. A magnetic flux H in the direction is generated. Thereby, the magnetostrictive element 3 extends in the longitudinal direction 7 by an amount corresponding to the magnetic flux density.

The two wiring methods for the magnetostrictive element 3 shown in FIGS. 8 and 9 can be applied to any of the two wiring methods for the electrostrictive element 2 shown in FIGS. 6 and 7.
FIG. 11 shows four models obtained by combining these wiring methods.
To FIG.

FIG. 11 shows a model M1 obtained by combining the electrostrictive element-side wiring method shown in FIG. 6 and the magnetostrictive element-side wiring method shown in FIG. The lead wires 11 and 12 are connected to the formed magnetostrictive element 3 and the electrode film 6 formed on the lower surface, respectively, while the outer periphery of the magnetostrictive electrostrictive mutual conversion element 1 is surrounded by the magnetostrictive element 3 so as to enclose the magnetostrictive element 3. The coil 20 is arranged, and this coil 2
The lead wires 25 and 26 are derived from 0. Electrostrictive element 2
Lead wires 11 and 12 on the side and lead wire 2 on the magnetostrictive element 3 side
If an input signal is supplied from one of the terminals 5 and 26 and an output signal is extracted from the other, an impedance conversion device is obtained.

FIG. 12 shows a model M2 in which the wiring method on the electrostrictive element side shown in FIG. 6 and the wiring method on the magnetostrictive element side shown in FIG. 9 are combined. The lead wires 11 and 12 are connected to the formed magnetostrictive element 3 and the electrode film 6 formed on the lower surface, respectively, while the folded conductive wire 29 is provided on the magnetostrictive element 3 and the lead wire 25 and 26 is derived. Similarly, when an input signal is supplied from one of the lead wires 11 and 12 on the electrostrictive element 2 side and one of the lead wires 25 and 26 on the magnetostrictive element 3 side, and an output signal is extracted from the other, an impedance conversion device is obtained.

FIG. 13 shows a model M3 obtained by combining the electrostrictive element side wiring method of FIG. 7 and the magnetostrictive element side wiring method of FIG. The lead wires 11,
12 is connected, the magnetostrictive element 3
Is formed, and an exciting coil 20 is arranged on the outer periphery of the magnetostrictive electrostrictive mutual conversion element 1 so as to surround the magnetostrictive element 3, and lead wires 25 and 26 are led out from the coil 20. Similarly, when an input signal is supplied from one of the lead wires 11 and 12 on the electrostrictive element 2 side and one of the lead wires 25 and 26 on the magnetostrictive element 3 side, and an output signal is extracted from the other, an impedance conversion device is obtained.

FIG. 14 shows a model M4 in which the wiring method on the electrostrictive element side in FIG. 7 and the wiring method on the magnetostrictive element side in FIG. 9 are combined, and the upper surface of the electrostrictive element 2 having the polarization direction P in the longitudinal direction 7 is shown. The magnetostrictive element 3 is formed in half, the folded conductive wire 29 is formed on the magnetostrictive element 3, and the comb-shaped electrodes 22 and 23 are formed on the electrostrictive element 2. This model M4 corresponds to a structure in which the output side of a SAW filter currently in practical use is configured by the electrostrictive element 2 having the comb-shaped electrodes 22 and 23. When an input signal is supplied from one of the lead wires 11 and 12 on the electrostrictive element 2 side and one of the lead wires 25 and 26 on the magnetostrictive element 3 side, and an output signal is extracted from the other, an impedance conversion device is obtained.

In the above models M1 to M4, any conversion from electrostriction to magnetostriction or from magnetostriction to electrostriction is performed. Since the conversion is conversion through mechanical strain, mechanical resonance is utilized. Conversion can be performed. Since the magnetostrictive element 3 is extremely thin compared to the electrostrictive element 2, only the mechanical resonance of the electrostrictive element 2 can be actually used.

That is, in any conversion from electrostriction to magnetostriction and from magnetostriction to electrostriction, the vibration mode of the electrostrictive element 2 at the same cycle as the cycle of the AC input signal, that is, the conversion accompanied by the direct vibration mode, There are two types of conversion involving the mechanical resonance mode of the electrostrictive element 2. The former is an impedance conversion operation, and the latter is a composite operation of selecting an input frequency in conjunction with impedance conversion. However, even in the direct vibration mode, when the comb-shaped electrodes 25 and 26 are used for the electrostrictive element 2 and the folded conducting wire 29 is used for the magnetostrictive element 3, the SA that performs the impedance conversion simultaneously is used.
A W filter is obtained.

The model M1 shown in FIG.
In M2 of No. 2, the magnetostrictive elements 3 may be formed on both the upper and lower surfaces of the electrostrictive element 2, and input or output may be performed to both magnetostrictive elements 3. In this case, both magnetostrictive elements 3 can be used as electrodes of the electrostrictive element 2.

The voltage-current converter or the current-voltage converter using the models M1 to M4 has input / output directions,
As shown in FIG. 15, the data is divided into eight categories A to H according to the vibration mode. Hereinafter, the operation of each of the classifications A to H will be described.

The classification A, conversion using a model M2 model M1 or 12 of the B 11 to the magnetostrictive from according electrostrictive to the present invention, i.e., performs a voltage-current conversion. Lead wire 1 of electrostrictive element 2
When an AC input voltage is applied to the electrostrictive element 2 via the elements 1 and 12, the electrostrictive element 2 generates electrostriction in the polarization direction by an amount corresponding to the voltage level, and expands and contracts in the longitudinal direction 7. The magnetostrictive element 3 expands and contracts in the longitudinal direction 7 integrally with the expansion and contraction of the electrostrictive element 2, and the magnetic permeability of the magnetostrictive element 3 changes.

On the other hand, a DC current is superimposed on the coil 20 of the model M1 or the folded conductor 29 of the model M2,
Alternatively, a magnetic bias is previously applied to the magnetostrictive element 3 by applying a magnetic flux by a permanent magnet. Then, the inductance value of the coil 20 or the folded conductor 29 changes according to the voltage change due to the change in the magnetic permeability of the magnetostrictive element 3 according to the voltage change of the AC input voltage.
Here, since a magnetic bias is applied to the magnetostrictive element 3, a change in magnetic flux in the coil occurs due to the change in magnetic permeability,
An electromotive force corresponding to the voltage change is generated in the coil 20 or the folded conducting wire 29. The current due to the electromotive force is extracted as a current signal via the lead wires 25 and 26. As a result, voltage input and current output impedance conversion is performed with the lead wires 11 and 12 of the electrostrictive element 2 as voltage input and the lead wires 25 and 26 of the magnetostrictive element 3 as current output (classification A and B).

The electrostrictive element 2 has a mechanically constant resonance frequency, and resonance occurs when the resonance frequency in the longitudinal direction 7 and the frequency of the AC input voltage match. Therefore, when the resonance frequency is apart from the input frequency, only the impedance conversion in the direct vibration mode is performed (class A). When the resonance frequency is near the input frequency, The output has selectivity with respect to the input frequency, and performs a frequency selection operation in addition to the inherent impedance conversion (class B).

Classification C, D Conversion from magnetostriction to electrostriction, that is, current-voltage conversion, is performed using the model M1 in FIG. 11 or the model M2 in FIG. When an AC input current is applied to the magnetostrictive element 3 via the lead wires 25 and 26 of the magnetostrictive element 3 to apply a magnetic field to the magnetostrictive element 3, the magnetostrictive element 3 extends in the direction of the magnetic flux by an amount corresponding to the magnetic flux density ( (Positive magnetostriction). Due to the extension of the magnetostrictive element 3, the electrostrictive element 2 is bent as shown in FIG. The change in the thickness of the electrostrictive element 2 due to the bending changes the voltage between the electrodes 3 and 6, and this voltage change is taken out from the lead wires 11 and 12. Thereby, impedance conversion of current input / voltage output is performed (classification C, D).

At this time, when the resonance frequency of the electrostrictive element 2 is far from the input frequency, only the impedance conversion in the direct vibration mode of the electrostrictive element 2 is performed (class C). When the frequency is close, the output mode has selectivity with respect to the input frequency due to the resonance mode, and the frequency selection operation is performed in addition to the inherent impedance conversion (class D).

Further, in the classifications C and D, as described below, there is a feature that an output obtained by multiplying the input frequency can be obtained. That is, as shown in FIG. 17A, when an AC input current Ia with a constant bias is applied to the coil 20 of FIG. 11 or the folded conductor 29 of FIG.
Since the exciting magnetic field appears as an increase or decrease in one direction, the amount of expansion of the magnetostrictive element 3 increases or decreases accordingly, and the voltage output Va of the same cycle as the input current is output from the electrostrictive element 2 as shown in FIG. Is obtained.

On the other hand, as shown in FIG.
The AC input current Ib without bias is applied to the coil 20
Alternatively, when the excitation magnetic field is applied to the folded conducting wire 29, the direction of the excitation magnetic field is inverted every half cycle, but the magnetostrictive element 3 extends by an amount corresponding to the magnetic flux density (positive magnetostriction) even if the magnetic field is inverted.
The expansion / contraction cycle (vibration cycle) of the magnetostrictive element 3 and the electrostrictive element 2 is の of the input current Ib. Therefore, as shown in FIG. 17D, a voltage output Vb having twice the frequency of the input current Ib is obtained.

Classifications E and F The conversion from electrostriction to magnetostriction, that is, voltage-current conversion according to the present invention is performed in the same manner as classifications A and B using the model M3 in FIG. 13 or the model M4 in FIG. is there. First,
A case where the model M3 in FIG. 13 is used will be described. When an AC input voltage is applied to the electrostrictive element 2 from the lead wires 11 and 12 of the electrostrictive element 2 through the comb-shaped electrodes 22 and 23, the electrostrictive element 2 moves in the longitudinal direction 7 by an amount corresponding to the voltage level. Electrostriction occurs in the polarization direction along the direction, and expands and contracts in the longitudinal direction 7.
Due to the expansion and contraction, the electrostrictive element 2 bends similarly to the case shown in FIG. 16, and the magnetostrictive element 3 also bends integrally with the electrostrictive element 2. As a result, the magnetostrictive element 3 expands and contracts in the longitudinal direction 7, and its magnetic permeability changes. The change in inductance due to the change in magnetic permeability is transferred from the coil 20 to the lead wires 25 and 26.
And is taken out as a current signal via. Thereby, impedance conversion of voltage input / current output is performed (classification E, F).

The model M4 shown in FIG. 14 corresponds to a structure in which the output side of the SAW filter is constituted by an electrostrictive element, as described above. Therefore, when an AC input voltage is input to the interdigital electrodes 22 and 23 of the electrostrictive element 2, the electrostrictive element 2 expands and contracts in the longitudinal direction 7, and the vibration caused by the expansion and contraction propagates through the surface layer of the electrostrictive element 2 and the magnetostrictive element 3 and is extracted as an AC output current from the folded conducting wire 29 of the magnetostrictive element 3 via the lead wires 25 and 26. As a result, the operation of adding the impedance conversion of the voltage input / current output to the selection operation as the conventional SAW filter is performed (classification E, F).

In both of the models M3 and M4, when the resonance frequency of the electrostrictive element 2 is far from the input frequency, only impedance conversion in the direct vibration mode of the electrostrictive element 2 is performed. E) When the resonance frequency and the input frequency are close to each other, the resonance mode has selectivity of the output with respect to the input frequency. In addition to the inherent impedance conversion,
A frequency selection operation is also performed (class F).

Classification G, H Conversion from magnetostriction to electrostriction, that is, current-voltage conversion, is performed using the model M3 in FIG. 13 or the model M4 in FIG. The operation is the reverse of that described in the above classifications E and F, and the AC input current supplied from the lead wires 25 and 26 on the magnetostrictive element 3 side is changed to the lead wire 11 on the electrostrictive element 2 side.
12 is taken out as an AC output voltage.

At this time, when the resonance frequency of the electrostrictive element 2 is far from the input frequency, only the impedance conversion in the direct vibration mode of the electrostrictive element 2 is performed (class G). When the frequency is close, the output has selectivity with respect to the input frequency due to the resonance mode. In addition to the inherent impedance conversion, the frequency selection operation is also performed (class H).

[0044] By the way, the magnetostrictive electrostrictive mutual conversion element 1
Can be used not only for the voltage-current or current-voltage converter, but also for a stress sensor capable of outputting both voltage and current. In FIG.
1 shows a electromechanical converter according to the present invention. Smell
Then, the lower surface of the electrostrictive element 2 is used as a displacement applying section 31, and the electrostrictive element 2 is fixed to a member 32 that causes mechanical displacement by means of an adhesive or the like via the adding section 31. Accordingly, when a mechanical displacement is applied to the electrostrictive element 2 from the member 32, a voltage signal corresponding to the displacement is extracted from the lead wires 11 and 12 of the electrostrictive element 2, while a current corresponding to the displacement is output. A signal is taken out from the lead wires 25 and 26 of the magnetostrictive element 3. Lead wires 11 and 12 constitute first output means
Then, the lead wires 25 and 26 constitute the second output means.
The member 32 has a relief groove 33 so that the magnetostrictive element 3 does not contact the member 32 when the electrostrictive element 2 is fixed.
Is provided.

Further, the magnetostrictive electrostrictive mutual conversion element 1 of the present invention can be used also for the AM modulator shown in FIG. In FIG. 19, the magnetostrictive electrostrictive mutual conversion element 1 is represented by an equivalent circuit including a capacitor C1 and a variable inductance L1, and functions as a variable inductance accompanied by a kind of voltage-current conversion operation. A capacitor C2 is connected in parallel to the variable inductance L1 to form a parallel resonance circuit 41, and a transistor 42 and a resistor R1 are connected in series to the parallel resonance circuit 41.

An input signal 46 having a frequency fa is supplied between input terminals 44 and 45 connected to both ends of the capacitor C 1, and a carrier 47 having a frequency fc is supplied to the base of the transistor 42. As shown in FIG.
1 is set higher (or lower) than the carrier frequency fc, L1 becomes the input signal 46.
As a result, the resonance frequency fo changes due to C2 · L1. This change in fo changes the impedance of the resonance circuit 41 with respect to the carrier frequency fc. That is, the farther the resonance frequency fo is from the carrier frequency fc, the smaller the impedance of the resonance circuit 41 with respect to the carrier frequency fc. This impedance change is regarded as a voltage change of the resistor R1, and
Extracted from 8, a modulated signal 49 AM-modulated by fa is obtained.

[0047]

As described above, the voltage and voltage of the present invention
The current converter gives an input signal to the electrostrictive element of the magnetostrictive electrostrictive mutual conversion element and takes out the output signal from the magnetostrictive element , so that there is no limit of the frequency band like a winding transformer, and like an active element. No complicated input and output circuits are required.

Further , in the electromechanical transducer of the present invention, when a displacement is added to the electrostrictive element from the outside, a voltage output signal whose level changes according to the displacement is output from the electrostrictive element, and a current output signal is magnetostricted. Since each element can be taken out of the element, for example, an electrostrictive element is bonded to a member to be measured, a stress sensor that detects a stress generated in the member to be measured, and outputs a detection signal as both a voltage and a current. realizable.

[Brief description of the drawings]

FIG. 1 is a diagram showing a voltage-current converter and a mechanical electric device according to the present invention.
It is a perspective view showing an example of a magnetostriction electrostriction mutual conversion element used for a gas converter .

FIG. 2 is a perspective view showing another example .

FIG. 3 is a perspective view showing an example of a mode of using the magnetostrictive electrostrictive mutual conversion element of FIG . 1 ;

FIG. 4 is a schematic configuration diagram showing an apparatus used for a test for confirming the effect of the magnetostrictive electrostrictive mutual conversion element of FIG . 1 ;

FIG. 5 is a view showing measured values by the same test.

6 is a perspective view showing one example of a wiring method on the electrostrictive element side of the magnetostrictive electrostrictive mutual conversion element in FIG . 1 ;

7 (a) is an electrostrictive element of the magnetostrictive electrostrictive mutual conversion element of FIG. 2;
FIG. 4 is a perspective view showing another example of the wiring method on the slave side, and FIG. 4 (b) is an enlarged sectional view showing a main part thereof.

FIG. 8 is a perspective view showing an example of a wiring method on the magnetostrictive element side of the magnetostrictive electrostrictive mutual conversion element.

FIG. 9 is a perspective view showing another example of the wiring method.

10 is a sectional view showing a magnetic flux generated in the magnetostrictive electrostrictive mutual conversion element in FIG.

FIG. 11 is a perspective view showing a model M1 in which wiring is applied to the magnetostrictive electrostrictive mutual conversion element of the voltage-current converter according to the present invention.

FIG. 12 is a perspective view showing a model M2 in which wiring is applied to the magnetostrictive electrostrictive mutual conversion element of the voltage-current converter according to the present invention.

FIG. 13 is a perspective view showing a model M3 in which wiring is applied to the magnetostrictive electrostrictive mutual conversion element of the voltage-current converter according to the present invention.

FIG. 14 is a perspective view showing a model M4 in which wiring is applied to the magnetostrictive electrostrictive mutual conversion element of the voltage-current converter according to the present invention.

FIG. 15 is a table in which models M1 to M4 are classified according to use modes.

FIG. 16 is a side view showing the operation of the magnetostrictive electrostrictive mutual conversion element in the current-voltage converter .

FIG. 17 is a signal waveform diagram showing an input current to the magnetostrictive element and an output voltage from the electrostrictive element of the magnetostrictive electrostrictive mutual conversion element.

FIG. 18 is a perspective view of a stress sensor showing the electromechanical converter according to the present invention.

FIG. 19 is a circuit diagram showing an example in which a magnetostrictive electrostrictive mutual conversion element is used for an AM modulator.

20 is a diagram showing a waveform of a resonance mode in the AM modulator of FIG. 19;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetostrictive electrostrictive mutual conversion element, 2 ... Electrostrictive element, 3 ... Magnetostrictive element, 5 ... Surface direction, 6 ... Electrode, 7 ... Longitudinal direction, 11, 12
... Lead wires on the electrostrictive element side, 20 ... Coils, 22, 23 ...
Comb-shaped electrode, 25, 26 ... lead wire on magnetostrictive element side, 29
... Folding wire, 31 ... Displacement adding part, 3,6,11,1
2, 20, 22, 23, 25, 26, 29 ... input / output means, P ... polarization direction.

Claims (2)

(57) [Claims] 1. A magnetostrictive electrostrictive mutual conversion element comprising a magnetostrictive element formed on an electrostrictive element so as to expand and contract integrally with the electrostrictive element so as to exhibit a mutual effect between the electrostrictive effect and the magnetostrictive effect.
Input means for supplying an input signal to the electrostrictive element;
Output means for extracting an output signal from the magnetostrictive element of
Voltage-current converter using a magnetostrictive electrostrictive mutual conversion element. 2. The magnetostrictive electrostrictive mutual conversion element according to claim 1, and first output means for extracting an output signal from the electrostrictive element .
Second output means for extracting an output signal from the magnetostrictive element;
The electrostrictive element has a mechanical displacement added from the outside.
Using a magnetostrictive electrostrictive mutual conversion element
Had a mechanical-electrical conversion device.