JP6710411B2 - Ultrasonic vibration device - Google Patents

Description

The present invention relates to an ultrasonic vibration device including an ultrasonic vibrator that generates ultrasonic vibrations.

2. Description of the Related Art As an ultrasonic vibration device, a device including a bolted Langevin type transducer (BLT-Clamped Langevin Type Transducer, BLT) as shown in Patent Documents 1 and 2 below is known.
The BLT is a piezoelectric element that is formed by stacking piezoelectric elements that are polarized in the stacking direction via an electrode plate, sandwiched between metal blocks, and integrally fastened with a fastener such as a bolt. It is capable of high-power vibration or ultrasonic vibration.
The BLT of Patent Document 1 generates vibration in the stacking direction (axial vibration), and the BLT of Patent Document 2 generates vibration in a direction intersecting with the stacking direction (flexural vibration).

The ultrasonic vibration device of Patent Document 1 is an ultrasonic treatment tool used for medical purposes such as coagulation and incision, and has a long probe that can reach an affected area from outside the body, and the probe (tool) is used. Is oscillated by BLT.
The ultrasonic vibration device of Patent Document 2 is a cutting device in which a cutting tool is flexibly vibrated by BLT. In recent years, thin tools such as knife-shaped or knife-shaped cutting tools for cutting foods are often used in addition to the cutting tool. There is.
These thin or thin tools have a shape with a high aspect ratio in which the dimension in the axial direction (longitudinal direction) is larger than the diameter and the thickness.
As described above, when ultrasonic vibration is applied to a tool having a high aspect ratio at a predetermined oscillation frequency, vibration (direction of unnecessary vibration) different from the ultrasonic vibration applied for driving occurs. Sometimes. When the unnecessary vibration matches the oscillation frequency of the applied vibration (when the applied vibration and the resonance mode of the unnecessary vibration match), when the unnecessary vibration coincides with a frequency that is an integer fraction of the oscillation frequency ( When the resonance mode of unnecessary vibration matches the low-order mode of vibration given), it also occurs.

Conventionally, in order to suppress unnecessary vibration, a weight balance that does not vibrate in a direction other than the direction of applied vibration is used, or rigidity is increased to suppress deformation.
However, there is a limit to the improvement of weight balance and rigidity, and the limit is relatively low particularly in a tool having a high aspect ratio shape. If the limit is exceeded and unwanted vibrations occur, the unwanted vibrations may change the vibration direction of the tool and affect the quality of machining. There is a possibility that noise will occur as a result of vibration in the tool, and unnecessary vibration may cause a great stress on the tool or the like to damage the tool, which may have an adverse effect.
Further, particularly in a tool having a high aspect ratio shape, a relatively large number of low-order modes related to flexural vibration exist. For example, when flexural vibration is performed in a third-order resonance mode (resonance for two wavelengths) with free ends, as a low-order mode, a second-order (resonance for 1.5 wavelengths) or a first-order (resonance for one wavelength) Resonance) mode is included.
Further, when the tool is replaceable, it is necessary to strictly control the weight balance, rigidity and the like of the tool and the members of the vibrator in order to suppress unnecessary vibration.
In addition, the resonance frequency of the vibrator, tool, etc. may change depending on the temperature, and, for example, when the temperature rises due to driving, unnecessary vibration may start to occur.
Further, particularly in the case of Patent Document 2, the cutting resistance increases as the cutting depth of the cutting edge of the bending vibrating tool increases, and when the cutting resistance exceeds a threshold value, the bending vibration at the original vibration frequency for driving is desired. It has been confirmed by the inventor of the present application that unnecessary vibrations are superimposed at frequencies that do not occur, and the unnecessary vibrations change the vibration direction of the cutting edge and cause vibration marks to appear on the machined surface. It has been confirmed to have an impact.

On the other hand, as a vibration suppression device that suppresses vibrations of a plate-shaped body that flexurally vibrates not by the BLT but by an actuator, the device of Patent Document 3 below is known.
In this vibration suppression device, a shunt circuit consisting of a series circuit of an inductor and a resistor is connected to a piezoelectric element that is adhered to a plate, and a resonant circuit is composed of the piezoelectric element and the shunt circuit that are considered to be equivalent to a capacitor in a restrained state. Has been done. Then, the inductance of the inductor is set according to the electrostatic capacity of the piezoelectric element, and the frequency of the resonant circuit is matched with the resonance frequency of the plate body, so that the vibration energy related to the specific resonance frequency of the plate body is It is converted into electric energy by the element and dissipated as heat energy through the shunt circuit. Therefore, the vibration at the specific resonance frequency is suppressed.

Japanese Patent No. 5124437 Japanese Patent Publication No. 6-49242 Japanese Patent No. 4810646

In an ultrasonic vibrating device capable of ultrasonic vibrating with a large output by including a BLT, a piezoelectric element is bonded to the device in order to suppress unnecessary vibration other than desired ultrasonic vibration for driving a tool, Even if the shunt circuit is connected to the piezoelectric element, it may not be possible to suppress unnecessary vibration.
That is, it is considered that the piezoelectric element bonded to the ultrasonic vibration device becomes high in temperature due to ultrasonic vibration, and the bonded state may not be maintained and the device may be separated from the device. Be done. For example, in a portion that ultrasonically vibrates at a frequency of 20 kHz (kilohertz) and an amplitude of 10 μm (micrometer), the acceleration is about 160000 m/sec ² (meters per second per second), which is a gravitational acceleration of 16000 G or more. It is acceleration, and it is considered that the possibility of withstanding such acceleration and maintaining the bonded state is considerably low.
In addition, since the bonding of the piezoelectric element affects the weight balance and rigidity of the BLT and the ultrasonic vibration device, simply bonding the piezoelectric element causes another unnecessary vibration and eventually suppresses the unnecessary vibration. May not be done.
It is an object of the present invention to provide an ultrasonic vibration device that can suppress unnecessary flexural vibration while including a vibrator (BLT) that generates ultrasonic vibration.

In order to achieve the above object, the invention according to claim 1 is a first piezoelectric element unit including one or more first piezoelectric elements, and a second piezoelectric element unit including one or more second piezoelectric elements. A pair of conductor blocks sandwiching the first piezoelectric element unit and the second piezoelectric element unit, and a fastener for fastening the first piezoelectric element unit, the second piezoelectric element unit, and the pair of conductor blocks. A vibrator having a vibrator, a tool connected to the vibrator, and a shunt circuit connected to the second piezoelectric element unit, and having a shunt circuit connected to the second piezoelectric element unit. , A tool connected to the vibrator, the first piezoelectric element unit generates a predetermined vibration in the vibrator when a drive voltage is applied, and the shunt circuit is configured to generate a predetermined vibration. It is characterized in that it is set so as to electrically resonate with the electrostatic capacitance indicated by the second piezoelectric element unit in flexural vibration other than vibration.
According to a second aspect of the present invention, in the above invention, the shunt circuit includes a series circuit of an inductor and a resistor.
In order to achieve the above object, the invention according to claim 3 is a first piezoelectric element unit including one or more first piezoelectric elements, and a second piezoelectric element unit including one or more second piezoelectric elements. A pair of conductor blocks sandwiching the first piezoelectric element unit and the second piezoelectric element unit, and a fastener for fastening the first piezoelectric element unit, the second piezoelectric element unit, and the pair of conductor blocks. The vibrator includes a vibrator and a tool connected to the vibrator, and the first piezoelectric element unit generates a predetermined vibration in the vibrator when a drive voltage is applied to the first piezoelectric element unit. Is adjusted according to the voltage generated in the second piezoelectric element in flexural vibration other than the predetermined vibration.
According to a fourth aspect of the present invention, in the above invention, the second piezoelectric element is biased or divided in a direction intersecting with a central axis of the vibrator.
According to a fifth aspect of the present invention, in the above-mentioned invention, the second piezoelectric element is biased or divided in a plurality of directions that intersect with the central axis of the vibrator and are different from each other. It is a feature.
According to a sixth aspect of the invention, in the above invention, the first piezoelectric element is biased or divided in a direction intersecting with a central axis of the vibrator.
According to a seventh aspect of the invention, in the above invention, the first piezoelectric element and the second piezoelectric element are polarized, and the polarization directions thereof are parallel to the central axis of the vibrator. It is characterized by that.
In order to achieve the above object, the invention according to claim 8 is a piezoelectric element unit including a plurality of piezoelectric elements, a pair of conductor blocks sandwiching the piezoelectric element unit, the piezoelectric element unit and a pair of the conductor blocks. And a tool connected to the vibrator. The plurality of piezoelectric elements are arranged so as to be separated in a direction intersecting with a central axis of the vibrator. By causing a drive current to flow through each of the plurality of piezoelectric elements, a predetermined vibration is generated in the vibrator, and at least one of the drive currents is generated by flexural vibration other than the predetermined vibration. It is characterized in that it is adjusted according to the difference of the currents that have changed in each element.
According to a ninth aspect of the present invention, in the above-mentioned invention, the plurality of piezoelectric elements are polarized, and the polarization directions thereof are parallel to the central axis of the vibrator. It is a thing.

According to the present invention, it is possible to provide an ultrasonic vibration device capable of suppressing unnecessary flexural vibration while including a vibrator (BLT) that generates ultrasonic vibration.

It is a typical perspective view of the ultrasonic vibration cutting device concerning a 1st form of the present invention. It is the (a) left side schematic diagram of the vibrator|oscillator which concerns on the apparatus of FIG. 1, and (b) (a) KK sectional schematic diagram. It is a typical left side view of the ultrasonic vibration cutting device concerning the 2nd form of the present invention. It is a typical perspective view of the ultrasonic vibration cutting device concerning the 3rd form of the present invention. 5 is a schematic left side view of a vibrator according to the device of FIG. 4. FIG. It is a typical left side view of the ultrasonic vibration cutting device concerning the 4th form of the present invention. It is a schematic diagram of the ultrasonic vibration cutting device which concerns on the 5th form of this invention. It is a schematic diagram of the ultrasonic vibration cutting device which concerns on the 6th form of this invention. 9 is a graph relating to various current waveforms, which is related to a simulation in the case where flexural vibration occurs at a frequency that is half the axial vibration of the fundamental wave in the device of FIG. 8.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The present invention is not limited to the embodiments described below.

[First form]
FIG. 1 is a schematic perspective view of an ultrasonic vibration cutting device 1 for food, which is an example of the ultrasonic vibration device according to the first embodiment of the present invention.
The ultrasonic vibration cutting device 1 includes a vibrator 2, a blade 4 which is a kind of tool, and a holder 6 for the vibrator 2.

The vibrator 2 also shown in FIG. 2 is a BLT, and includes a vibration-generating piezoelectric element unit 10 as a first piezoelectric element unit for generating a desired vibration (a desired vibration) and an undesired vibration (a desired vibration). Vibration-preventing piezoelectric element unit 12 as a second piezoelectric element unit for suppressing vibration), three electrode plates 14 to 16, a thin insulating cylinder 18, and a taper for increasing vibration amplitude. The metal member 20, the metal block 22 having a thick cylindrical shape, and the bolt 24 as a fastener.
In the vibrator 2, the metal block 20 side is the front side, the metal block 22 side is the rear side, and the side on which the connecting portion 38 of the electrode plate 16 described later is arranged is the left side. The front, rear, top, bottom, left and right can be changed in various ways.
In the vibrator 2, the vibration-generating piezoelectric element unit 10, the vibration-proof piezoelectric element unit 12, the electrode plates 14 to 16, the insulating cylinder 18, the metal material 20, the metal block 22, and the bolt 24 have central axes directed in the front-rear direction. Are arranged coaxially. Note that, in FIG. 1, the electrode plates 14 to 16 and circuits are omitted. Wiring is omitted in each drawing except the circuit portion.

The vibration generating piezoelectric element unit 10 can generate ultrasonic vibration in the axial direction (longitudinal direction of the vibrator), and has a known configuration related to the generation of the axial vibration.
The ultrasonic vibration (vibration at a frequency in the ultrasonic range) may be approximately 16 kHz or higher, or may be 20 kHz or higher. The present invention may be applied to a vibrating device including a vibrator driven by a vibration of less than 16 kHz.

The vibration generating piezoelectric element unit 10 includes two driving piezoelectric elements 30, 30 each having a disk shape. The polarization direction of the remanent polarization of each driving piezoelectric element 30 as the first piezoelectric element is parallel to the central axis of the vibrator 2 (thickness direction). The number of driving piezoelectric elements included in the vibration generating piezoelectric element unit may be one or three or more, but is preferably an even number from the viewpoint of ease of configuration.
The driving piezoelectric elements 30, 30 are arranged in the thickness direction with the central axis, which is the thickness direction, being coaxial, and the annular electrode plate 14 is sandwiched between them. The electrode plate 14 includes a connecting portion 32 that projects radially outward.

The vibration isolation piezoelectric element unit 12 includes four vibration isolation piezoelectric elements 34, 34... Which are U-shaped (semi-annular) plate-shaped members. The polarization direction of each vibration isolation piezoelectric element 34 as the second piezoelectric element is parallel to the central axis of the vibrator 2 (thickness direction).
Two of these vibration-proof piezoelectric elements 34, 34... Are arranged vertically on the side close to the vibration-generating piezoelectric element unit 10 so as to form an annular shape having a space in the left-right direction (2 Split annular piezoelectric element). It can be said that these vibration isolation piezoelectric elements 34, 34 are evenly divided. The polarization directions of the anti-vibration piezoelectric elements 34, 34 are opposite to each other. Here, the polarization direction of the upper half of the anti-vibration piezoelectric element 34 is the front direction, and the polarization direction of the lower half of the anti-vibration elements 34, 34 is 34. The polarization direction of the vibrating piezoelectric element 34 is backward. An annular electrode plate 15 is sandwiched between the front surfaces of the vibration isolation piezoelectric elements 34, 34 and the rear surface of the driving piezoelectric element 30 in the rear portion of the vibration generating piezoelectric element unit 10. The electrode plate 15 includes a connecting portion 36 that projects outward in the radial direction.
Further, on the rear side of these vibration-proofing piezoelectric elements 34, 34, another pair of vibration-proofing piezoelectric elements 34, 34 are arranged so as to form a ring having a similar interval (divided into two). Annular piezoelectric element). The polarization directions of the vibration isolation piezoelectric elements 34, 34 are opposite to each other. Here, the polarization direction of the upper vibration isolation piezoelectric element 34 is the backward direction, and the polarization direction of the lower vibration isolation piezoelectric element 34 is opposite. The polarization direction is forward.
Further, an annular electrode plate 16 is sandwiched between the vibration-proof piezoelectric elements 34, 34 adjacent to the vibration-generating piezoelectric element unit 10 and the rear-side vibration-proof piezoelectric elements 34, 34. The electrode plate 16 includes a connecting portion 38 that projects outward in the radial direction. It should be noted that it may be considered that the vibration isolation piezoelectric element unit 12 includes at least one of the electrode plate 15 and another electrode plate.
Therefore, the polarization directions of the upper two vibration isolation piezoelectric elements 34, 34 are separated from each other with the electrode plate 16 interposed therebetween, and the polarization directions of the lower two vibration isolation piezoelectric elements 34, 34 are The plates 16 are sandwiched in between and face each other.
The insulating cylinder 18 made of an insulating material is passed through the inner holes of the driving piezoelectric elements 30 and 30 and the two pairs of vibration damping piezoelectric elements 34. The bolt 24 can enter the inner hole of the insulating cylinder 18.

The metal material 20 as the conductor block is formed to have a taper shape that becomes thinner as it approaches the front end portion (the area of the cross section orthogonal to the central axis gradually decreases). Examples of the type of taper shape include a conical horn shape, an exponential horn shape, and a step horn shape. A tool attachment portion 40, which is a female screw hole for connecting the blade 4, is formed at the front end of the metal material 20. The tool attachment portion 40 is opened rearward from the front surface of the metal material 20. On the other hand, a bolt hole 42 into which the bolt 24 is inserted is formed at the rear end of the metal material 20. The bolt hole 42 is opened forward from the rear surface of the metal material 20.
A bolt 24 can be inserted into the inner hole of the metal block 22 serving as another conductor block.

The driving piezoelectric elements 30 and 30 and the two pairs of anti-vibration piezoelectric elements 34, 34,..., Including the common insulating cylinder 18 in addition to the electrode plates 14 to 16 in order, the metal member 20. And is sandwiched between metal blocks 22. These are fastened from the rear of the metal block 22 by the inner hole of the metal block 22, the inner hole of the insulating cylinder 18, and the bolt 24 that enters the bolt hole 42.
By such fastening, the driving piezoelectric elements 30, 30 and the two pairs of vibration damping piezoelectric elements 34, 34... Are restrained with sufficient strength, and the restrained state is maintained even by ultrasonic vibration.
The front surface of the front driving piezoelectric element 30 contacts the rear surface of the metal material 20 and is grounded, and the rear surface of the rear vibration damping piezoelectric elements 34, 34 contacts the front surface of the metal block 22 and is grounded.

A well-known drive voltage applying circuit (drive voltage applying means, not shown) for generating shaft vibration is connected to the electrode plates 14 and 15.
Here, the ground is connected to the connecting portion 36 of the electrode plate 15, and a predetermined AC voltage is applied to the connecting portion 32 of the electrode plate 14. Grounding is performed by connecting to the metal material 20 or the metal block 22, for example. When an AC voltage is applied to the electrode plate 14, the driving piezoelectric elements 30, 30 generate axial vibration (vibration in a direction parallel to the central axis of the vibrator 2). The vibrator 2 has a predetermined resonance frequency for each of axial vibration and flexural vibration due to its shape (whether the length or diameter is not large or its distribution or the like) or the structure of weight distribution, and the driving piezoelectric element 30, When a predetermined AC voltage is applied to 30, the oscillator 2 causes axial vibration in the first resonance mode. The axial vibration in the first-order resonance mode has a maximum amplitude when both ends are open, and one node (node) having the minimum amplitude (zero) exists on the vibrator 2. Although the flexural vibration is not positively generated by the driving piezoelectric elements 30 and 30, the vibrator 2 does not have the holder in the flange portion 26 provided at the node of the shaft vibration in the primary resonance mode. It is supported by 6.

Further, a shunt circuit 50 is connected to the electrode plate 16 via a connecting portion 38. The shunt circuit 50 is composed of an inductor 52 and a resistor 54 connected in series. The circuit end of the shunt circuit 50 opposite to the electrode plate 16 is grounded.
The inductance L of the inductor 52 is electrically connected to the electrostatic capacitance C exhibited by the vibration-proof piezoelectric elements 34, 34... (Vibration-proof piezoelectric element unit 12) in the restrained state in the flexural vibration related to the third resonance mode. It is supposed to resonate.
Further, the resistance value R of the resistor 54 is set to the same value as the internal impedance in the third-order flexural vibration.

The drive voltage applying circuit and the shunt circuit 50 are built in an ultrasonic oscillator (not shown) and electrically connected to the vibration generating piezoelectric element unit 10 or the vibration isolating piezoelectric element unit 12 via the cord 60. There is.
At least one of these circuits may be built in the vibrator 2 or the holder 6.

The operation example of the ultrasonic vibration cutting device 1 is as follows.
That is, when a predetermined AC voltage is applied to the vibration generating piezoelectric element unit 10, the vibrator 2 axially vibrates, and the blade 4 connected to the tool mounting portion 40 of the metal material 20 ultrasonically vibrates in the axial direction. The operator cuts the food such as cake by the ultrasonically vibrated blade 4 in a state in which the cutting resistance is reduced and the cutting performance is excellent, without crushing or scattering fragments. be able to.
Further, during the work, a flexural vibration may occur in the vibrator 2, and such a flexural vibration is superimposed on the shaft vibration for driving the cutting tool 4 to change the vibration direction of the cutting tool 4 and the like, thereby cutting quality. Is an unwanted vibration that affects the noise. In the ultrasonic vibration cutting device 1, even if flexural vibration in an undesired third-order resonance mode begins to occur, the energy is converted into electric energy by the vibration isolation piezoelectric element unit 12, and further the shunt circuit 50 heats it. Turn it into energy and dissipate it.
The shunt circuit 50 includes an inductor 52 having an inductance L adjusted so as to resonate in accordance with the capacitance C indicated by the vibration-proof piezoelectric element unit 12 in the third-order flexural vibration. The energy of is converted into heat energy, and the energy of other vibrations is not converted into heat energy.
Further, in the shunt circuit 50, since the resistance value R of the resistor 54 is set to the same value as the internal impedance in the third-order flexural vibration, the electric energy can be most efficiently converted into heat energy and dissipated.

The ultrasonic vibration cutting device 1 according to the first embodiment includes a vibration generating piezoelectric element unit 10 including two driving piezoelectric elements 30 and 30, and four (2 pairs) vibration damping piezoelectric elements 34, 34... Anti-vibration piezoelectric element unit 12, a metal material 20 and a metal block 22 that sandwich the vibration generation piezoelectric element unit 10 and the vibration isolation piezoelectric element unit 12, the vibration generation piezoelectric element unit 10 and the vibration isolation piezoelectric element A vibrator 2 having a unit 12 and bolts 24 for fastening the metal material 20 and the metal block 22, a blade 4 connected to the vibrator 2, and a shunt circuit 50 connected to the vibration isolation piezoelectric element unit 12. , The vibration generating piezoelectric element unit 10 (driving piezoelectric elements 30 and 30) generates axial vibration in the vibrator 2 when a driving voltage is applied, and the shunt circuit 50 has the axial vibration. It is set to electrically resonate with the electrostatic capacitance C indicated by the vibration-proof piezoelectric element unit 12 in the third flexural vibration other than the vibration.
Therefore, only the flexural vibration energy in the third-order resonance mode can be taken out as electric energy by the vibration isolation piezoelectric element unit 12, converted into thermal energy by the shunt circuit 50, and diverged, resulting in the third-order resonance. Unnecessary flexural vibration in the mode is suppressed. Here, in the BLT in which the driving piezoelectric elements 30 and 30 are sandwiched by the metal blocks and fastened by the fastener, it is possible to generate ultrasonic vibration of high output (at least one of high frequency and large amplitude). In the vibrator 2 as well, the vibration-proof piezoelectric elements 34, 34,... Are sandwiched together, so that unnecessary vibration is reliably suppressed without being separated from the vibrator 2. Further, various vibration-isolating members such as the vibration-isolating piezoelectric elements 34, 34... Are easily arranged symmetrically about the central axis (front-back direction) of the vibrator 2, and the vibration-isolating members are incorporated. The weight balance is excellent even in the post-heating state. Therefore, unnecessary vibrations can be prevented from affecting the target shaft vibrations, and the installation of vibration damping members can prevent the situation from affecting the weight balance. Of course, the quality is excellent, and the quality of cutting by a tool having a high aspect ratio (the blade 4 or the like) is also very good.

In addition, since the shunt circuit 50 includes the series circuit of the inductor 52 and the resistor 54, it is possible to easily convert electric energy into heat energy or to dissipate energy.
Further, the vibration-proof piezoelectric elements 34, 34,... Are divided (divided into upper and lower parts) in a direction (vertical direction) intersecting with the central axis of the vibrator 2. Therefore, the vibration-proof piezoelectric elements 34, 34,... Conform to the suppression of flexural vibration.
The driving piezoelectric elements 30, 30 and the vibration isolation piezoelectric elements 34, 34... Are polarized, and their polarization directions are parallel to the central axis of the vibrator 2 (front-back direction). There is. Therefore, the configuration for applying desired vibration and suppressing unnecessary vibration becomes simple.

The following modifications exist in the first embodiment.
Regarding the vibration isolation piezoelectric element unit, the front two vibration isolation piezoelectric elements are omitted, the rear two vibration isolation piezoelectric elements are omitted, and the upper two vibration isolation piezoelectric elements are omitted. It may be omitted, two lower vibration isolation piezoelectric elements may be omitted, the number of vibration isolation piezoelectric elements may be increased or decreased to an arbitrary number of 1 or more, and the polarization directions may be switched up and down or left and right. Etc., the configuration may be variously changed. If the two piezoelectric elements on the upper side or the lower side are omitted, the vibration-proof piezoelectric elements are biased in the direction intersecting with the central axis of the vibrator (vertical direction), and in this case, they are omitted. Also, it is preferable to provide the spacer on the side where the spacer (which may be integral with or separate from the metal material or the metal block) which does not have the same size or weight as the piezoelectric element is omitted. The electrode plate can also be variously modified, such as being further divided. Further, the piezoelectric element divided into two parts is one in which only the upper part and the lower part which are separated from each other in the ring-shaped piezoelectric element main body are polarized, that is, the polarized upper part and the non-polarized central part (in the gap It may be an annular shape having a corresponding portion) and a polarized lower portion.
Regarding the fastener, a bolt for fastening the vibration-proof piezoelectric element unit and a bolt for fastening the vibration-generating piezoelectric element unit may be provided.
The shunt circuit may be configured differently, and the inductance may be set so as to resonate with the capacitance shown during the flexural vibration of the second or lower order or the fourth or higher order, and the resistance value may be the same as that of the first embodiment. May be another value.
The target vibration (predetermined vibration) may be shaft vibration of secondary or higher order, or may be switchable to any one of a plurality of vibration states such as primary or secondary. Elliptic vibration (including circular vibration) in which flexural vibration is superimposed on axial vibration may be adopted as the target vibration.
As the electrode plate, one in which the connecting portion is omitted may be adopted, or one formed by applying a conductor to the surface of the piezoelectric element is adopted, and a cord or the like is connected to the applied conductor. Is also good.
A spacer of a conductor may be arranged between the vibration generating piezoelectric element unit and the vibration isolating piezoelectric element unit so that these units are separated from each other. A spacer may be arranged in each piezoelectric element unit.
In the first embodiment, instead of the ultrasonic cutting device for food, a device for ultrasonically cutting another work, a device for performing a process other than cutting on a work by a tool that vibrates ultrasonically, or a medical device is used. It may be applied to an ultrasonic vibration device for other uses.

[Second form]
FIG. 3 is a schematic left side view of the vibrator 202 included in the ultrasonic vibration cutting device for food according to the second embodiment of the present invention.
The second mode is the same as the first mode, except for the number and shape of the electrode plates and the number and settings of the shunt circuits in the vibration damping piezoelectric element unit. The same members and the like as those in the first embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted.

In the second embodiment, two electrode plates 216 and 216 related to the vibration-proof piezoelectric element unit 212 are provided. Each electrode plate 216 is formed in a semi-annular shape so as to fit on one surface of one vibration-proof piezoelectric element 34, and has a connecting portion 238 protruding in the radial direction.
The electrode plates 216 and 216 are arranged vertically (annular electrode plates divided into two) so as to form an annular shape having a space in the left-right direction. The electrode plates 216 and 216 are sandwiched between the pair of upper or lower anti-vibration piezoelectric elements 34 and 34 with their semi-annular surfaces aligned.
Then, the first shunt circuit 250 is connected to the upper electrode plate 216, and the second shunt circuit 260 is connected to the lower electrode plate 216.
The first shunt circuit 250 has an inductor 252 and a resistor 254 connected in series. The circuit end of the shunt circuit 250 opposite to the electrode plate 216 is grounded.
The inductance L2 of the inductor 252 is sized to electrically resonate with the electrostatic capacitance C2 exhibited by the upper vibration-damping piezoelectric elements 34, 34 in the restrained state in the flexural vibration in the secondary resonance mode.
The resistance value R2 of the resistor 254 is set to the same value as the internal impedance in the secondary flexural vibration.
The second shunt circuit 260 has an inductor 262 and a resistor 264 connected in series. The circuit end of the shunt circuit 260 opposite to the electrode plate 216 is grounded.
The inductance L3 of the inductor 262 is sized to electrically resonate with the electrostatic capacitance C3 exhibited by the vibration damping piezoelectric elements 34, 34 on the lower side in the restrained state in the flexural vibration in the third resonance mode.
Further, the resistance value R3 of the resistor 264 is set to the same value as the internal impedance in the third-order flexural vibration.

In the ultrasonic vibration cutting device according to the second embodiment, even if flexural vibration in an undesired secondary resonance mode starts to occur, the energy is transferred to the upper pair of vibration isolation piezoelectric elements 34, 34 and the first vibration isolation device. By the shunt circuit 250, it is converted into electric energy, and further converted into heat energy to be dissipated.
The first shunt circuit 250 includes an inductor 252 having an inductance L2 adjusted to resonate in accordance with the capacitance C2 indicated by the pair of vibration damping piezoelectric elements 34, 34 on the upper side in the secondary flexural vibration. Therefore, the energy of the secondary flexural vibration is changed to thermal energy, and the energy of other vibrations is not changed to thermal energy.
Further, even if flexural vibration in an undesired third-order resonance mode begins to occur, its energy is converted into electrical energy by the pair of lower vibration isolation piezoelectric elements 34, 34 and the second shunt circuit 260. It is converted into heat energy and then dissipated.
The second shunt circuit 260 includes an inductor 262 having an inductance L3 adjusted according to the electrostatic capacitance C3 indicated by the pair of vibration damping piezoelectric elements 34, 34 on the lower side in the third flexural vibration, The energy of the third flexural vibration is converted into heat energy, and the energy of other vibrations is not converted into heat energy.
Further, in the second shunt circuit 260, the resistance value R3 of the resistor 264 is set to the same value as the internal impedance in the third-order flexural vibration, so that the electrical energy can be most efficiently converted into thermal energy in the third-order flexural vibration. Can be converted and dissipated.
As described above, in the ultrasonic vibration cutting device according to the second embodiment, it is possible to suppress two types of unnecessary vibration that differ mainly in the order of the vibration mode.

In the second mode, the same modification examples as in the first mode are appropriately present, and the following modification examples are also present.
The types of unnecessary flexural vibrations to be suppressed may be variously changed by adjusting the inductances in the first and second shunt circuits. For example, the first-order and second-order flexural vibrations may be suppressed, or the fourth-order flexural vibrations and the fifth-order flexural vibrations may be suppressed.
By increasing the number of vibration-proof piezoelectric elements in the circumferential direction (increasing the number of divisions) and correspondingly increasing the number of shunt circuits, it is possible to suppress three or more unnecessary flexural vibrations. May be.

[Third mode]
FIG. 4 is a schematic perspective view of the vibrator 302 included in the ultrasonic vibration cutting device for food according to the third embodiment of the present invention, and FIG. 5 is a schematic left side view of the vibrator 302. Is. In FIG. 4, various electrode plates and circuits are omitted.
The third mode is the same as the first mode except for the configuration of the vibration-proof piezoelectric element unit and the number of shunt circuits installed. The same members and the like as those in the first embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted.

In the third mode, the vibration isolation piezoelectric element unit 312 includes eight vibration isolation piezoelectric elements 34, 34,. The four vibration-damping piezoelectric elements 34, 34,... And the electrode plate 16 have the same structure as the vibration-damping piezoelectric element unit 12 of the first embodiment or the electrode plate 16 sandwiched therebetween. Further, the other four vibration-damping piezoelectric elements 34, 34,... Are similarly arranged with the same electrode plate 316 as the electrode plate 16 interposed therebetween.
Then, on the rear side of the vibration generating piezoelectric element unit 10, four vibration damping piezoelectric elements 34, 34 sandwiching the electrode plate 316 are arranged so as to be adjacent to each other with the electrode plate 15 interposed therebetween. In, the four vibration-damping piezoelectric elements 34, 34 sandwiching the electrode plate 16 are arranged so as to be adjacent to each other via the electrode plate 317. The directions of the gaps in the two pairs (four) of the vibration isolation piezoelectric elements 34, 34,... Between which the electrode plate 316 is sandwiched are the vertical directions, and these vibration isolation piezoelectric elements 34, 34. It is divided in the left-right direction, which is the direction intersecting the direction parallel to the central axis (front-back direction). Further, the directions of the gaps in the two pairs (four) of the vibration isolation piezoelectric elements 34, 34,... Between which the electrode plate 16 is sandwiched are the left and right directions, and these vibration isolation piezoelectric elements 34, 34. It is divided in the up-down direction, which is the direction intersecting the direction parallel to the central axis of 2 (front-back direction).
The vibration-generating piezoelectric element unit 10 and the vibration-damping piezoelectric element unit 312 including the eight vibration-damping piezoelectric elements 34, 34 are sandwiched by the metal material 20 and the metal block 22, and fastened by the bolts 24. Therefore, separation from the vibrator 302 is prevented.

The electrode plate 316 has a connecting portion 338 protruding outward in the radial direction, and the electrode plate 317 has a connecting portion 335 protruding outward in the radial direction.
The electrode plate 317 is grounded like the electrode plate 15 via the connection portion 335.
A shunt circuit 350 similar to the shunt circuit 50 is connected to the electrode plate 316 via a connection portion 338. The inductance L of the inductor 352 of the shunt circuit 350 is the same as the inductor 52 of the shunt circuit 50, and the resistance value R of the resistor 354 of the shunt circuit 350 is the same as the resistor 54 of the shunt circuit 50.

In the ultrasonic vibration cutting device according to the third embodiment, even if flexural vibration in an undesired third-order resonance mode begins to occur mainly in the vertical direction in the vibrator 302, the energy is mainly sandwiched between the electrode plates 16. The two pairs of anti-vibration piezoelectric elements 34, 34,... And the shunt circuit 50 convert the electric energy into heat energy and further dissipate the heat energy.
Further, even if flexural vibration in an undesired third-order resonance mode starts to occur mainly in the left-right direction, the energy is mainly absorbed by the two pairs of vibration-proof piezoelectric elements 34, 34,... Which sandwich the electrode plate 316. With the second shunt circuit 350, it is converted into electric energy and further into heat energy to be dissipated.
As described above, in the ultrasonic vibration cutting device according to the third embodiment, the vibration isolation piezoelectric elements 34, 34... Are in a plurality of directions that intersect with the central axis of the vibrator 2 and are different from each other, that is, in the vertical direction and the horizontal direction. Since it is divided in, it is possible to suppress two types of unnecessary vibrations that differ mainly in the vibration direction.

In the third mode, there are appropriately modified examples similar to the first mode and the second mode.
In particular, also in the third mode, the types of unnecessary vibrations to be suppressed may be variously changed by adjusting the inductance in the first and second shunt circuits. For example, the secondary flexural vibration in the horizontal direction and the secondary flexural vibration in the vertical direction may be suppressed, or the quaternary flexural vibration in the lateral direction and the quaternary flexural vibration in the vertical direction are suppressed. Alternatively, the secondary flexural vibration in the horizontal direction and the tertiary flexural vibration in the vertical direction may be suppressed.
In addition, by providing piezoelectric elements that are divided in a direction that intersects the central axis of the vibrator and that is different from the vertical direction and the horizontal direction, unnecessary flexural vibration in that diagonal direction is further suppressed. It may be done.

[Fourth form]
FIG. 6 is a schematic left side view of the vibrator 402 included in the ultrasonic vibration cutting device for food according to the third embodiment of the present invention.
The fourth mode is the same as the first mode except the configuration of the vibration generating piezoelectric element unit and the setting of the shunt circuit. The same members and the like as those in the first embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted.

The vibration-generating piezoelectric element unit 410 of the vibrator 402 of the fourth mode is capable of generating ultrasonic vibrations in the flexural direction, and has a known configuration relating to the flexural vibration (see Patent Document 2 above). ..
The vibration generating piezoelectric element unit 410 includes four driving piezoelectric elements 430, 430,... The polarization direction of each driving piezoelectric element 430 is in the thickness direction, and is parallel to the central axis of the oscillator 402.
Two of the driving piezoelectric elements 430, 430,... Are divided in the vertical direction so as to form an annular shape having a space in the horizontal direction on the side close to the metal material 20. The front surfaces of these driving piezoelectric elements 430, 430 are in common contact with the metal material 20, and the rear surfaces thereof are in contact with the semi-annular electrode plates 414, 414. Each electrode plate 414 has connecting portions 432 and 432 protruding outward.
Further, on the rear side of the electrode plates 414, 414, another pair of driving piezoelectric elements 430, 430 is divided in the vertical direction so as to form a ring having a similar spacing. The rear surfaces of these electrode plates 414 and 414 are in contact with the grounded annular electrode plate 15.
The vibration generating piezoelectric element unit 410 is driven by a known driving voltage applying circuit (driving voltage applying means, not shown) for generating flexural vibration according to the polarization direction of the driving piezoelectric elements 430, 430. The drive voltage application circuit is connected at the connection portion 432 of each electrode plate 414, and applies a drive voltage that causes flexural vibration (target vibration) associated with the third-order resonance mode in the vibrator 2. For example, the polarization directions of the upper driving piezoelectric elements 430 and 430 face each other by moving toward the electrode plate 414, and the polarization directions of the lower driving piezoelectric elements 430 and 430 respectively face the opposite side of the electrode plate 414. Therefore, when they are separated from each other, the desired flexural vibration is generated if the drive voltages of the same phase are applied. Alternatively, when the polarization directions of the upper and lower driving piezoelectric elements 430, 430 are matched with each other, if a driving voltage of opposite phase is applied, a desired flexural vibration occurs.

Then, the vibration-proof piezoelectric element unit 12 of the vibrator 402 of the fourth mode is arranged on the rear side of the electrode plate 15 in the same manner as in the first mode.
A shunt circuit 450 is connected to the electrode plate 16.
The shunt circuit 450 includes an inductor 452 and a resistor 454 connected in series. The inductance L4 of the inductor 452 is sized to electrically resonate with the electrostatic capacitance C4 exhibited by the vibration-damping piezoelectric elements 34, 34... In the restrained state in the flexural vibration in the secondary resonance mode.
Further, the resistance value R4 of the resistor 454 is set to the same value as the internal impedance in the secondary flexural vibration.

In the ultrasonic vibration cutting device according to the fourth aspect, even if flexural vibration in an undesired secondary resonance mode begins to occur during flexural vibration in the intended tertiary resonance mode, the energy is With the vibration-proof piezoelectric element unit 12 and the shunt circuit 450, the energy is converted into electric energy and further converted into heat energy to be dissipated.
The shunt circuit 450 includes an inductor 452 having an inductance L4 adjusted to resonate in accordance with the electrostatic capacitance C4 indicated by the vibration-proof piezoelectric element unit 12 in the secondary flexural vibration, and the secondary flexural vibration. The energy of is converted into heat energy, and the energy of other vibrations is not converted into heat energy.
As described above, in the ultrasonic vibration cutting device according to the fourth embodiment, in the vibrator 402 intended for flexural vibration at a predetermined frequency (third-order resonance mode frequency), a specific frequency (from the third-order It is possible to suppress flexural vibration (undesired flexural vibration) in a low-order secondary resonance mode frequency).
Further, since the driving piezoelectric elements 430, 430,... Are divided in the direction (vertical direction) intersecting the central axis of the vibrator 402, the configuration is suitable when the desired vibration is flexural vibration.

In the fourth mode, the same modifications as at least one of the first to third modes are appropriately present, and the following modifications are also present.
The desired flexural vibration is the fourth-order flexural vibration, the unwanted flexural vibration is the third-order flexural vibration, or the desired flexural vibration is the second-order flexural vibration, and the unwanted flexural vibration is the third-order flexural vibration. The combination of resonance modes related to driving and vibration isolation may be variously changed, such as flexural vibration. The resonance mode (order) of the desired flexural vibration may be switchable.
The vibration generating piezoelectric element unit may include a driving piezoelectric element related to flexural vibration and a driving piezoelectric element related to axial vibration, and the tool may perform elliptical vibration (including circular vibration).

[Fifth form]
FIG. 7 is a schematic diagram of the blade 4, the vibrator 502, and the circuit included in the ultrasonic vibration cutting device for food according to the fifth embodiment of the present invention.
The fifth mode is the same as the fourth mode except for the configurations of the vibration isolation piezoelectric element unit, the vibration generation piezoelectric element unit, and the circuit. Members and the like that are the same as those in the fourth embodiment are designated by the same reference numerals, and description thereof will be omitted as appropriate.

The vibration generating piezoelectric element unit 510 of the vibrator 502 of the fifth mode is the same as the vibration generating piezoelectric element unit 410 of the fourth mode, and the driving piezoelectric element 530 and the electrode plate similar to the driving piezoelectric element 430. The same electrode plate 514 (connecting portion 532) as 414 (connecting portion 432) is provided.
However, the vibration generating piezoelectric element unit 510 generates primary axial vibration. Here, of the four driving piezoelectric elements 530, 530,..., if the upper two are PZT1 and the lower two are PZT2, the polarization directions of PZT1 and PZT2 are the same. , PZT1 are applied to the electrode plate 514 at the same phase. The vibration generating piezoelectric element unit 510 is arranged on the rear side of the vibration detecting piezoelectric element unit 512.

The vibration detecting piezoelectric element unit 512 (second piezoelectric element unit) for detecting unnecessary vibration according to the fifth mode is the same as the vibration preventing piezoelectric element unit 212 of the second mode, and the vibration preventing piezoelectric element is used. The vibration detecting piezoelectric element 534 (second piezoelectric element) similar to the reference numeral 34 and the electrode plate 516 (connecting portion 538) similar to the electrode plate 216 (connecting portion 238) are provided.
Of the four vibration detecting piezoelectric elements 534, 534,... If the upper two are PZT3 and the lower two are PZT4, the polarization directions are the same in PZT3 and PZT4.
The electrode plate 15 having the connection portion 36 is arranged between the vibration detecting piezoelectric element unit 512 and the vibration generating piezoelectric element unit 510.
In PZT3 and PZT4, distortion due to compression causes a positive voltage depending on the magnitude of distortion.
An electrode plate 517 similar to the electrode plate 15 is arranged between the vibration generating piezoelectric element unit 510 and the metal block 22. The electrode plate 517 has a connecting portion 539.
The electrode plates 15 and 517 are grounded via the connecting portions 36 and 539.

The driving or vibration isolation circuit 570 of the fifth embodiment includes a driving power supply 572, a multiplier 574, amplifiers (AMP) 576 and 578, and a voltage comparator 579. The circuit 570 doubles as a driving voltage applying unit and a driving voltage adjusting unit. More specifically, the driving power supply 572 and the amplifiers (AMPs) 576 and 578 constitute a driving voltage applying unit, and the multiplier 574 and the voltage comparator 579. Constitutes the drive voltage adjusting means. It should be noted that the drive voltage adjusting means may be considered to include PZT3, PZT4, or electrode plates 516 and 516.
The driving power supply 572 and PZT1 are connected via a multiplier 574, an amplifier 576, and an electrode plate 514 (connecting portion 532). The AC voltage generated by the driving power supply 572 is passed through the multiplier 574, amplified by the amplifier 576, and applied to the PZT 1 via the electrode plate 514 (connecting portion 532).
The drive power source 572 and PZT2 are connected via an amplifier 578 and an electrode plate 514 (connecting portion 532). The AC drive voltage generated by the drive power supply 572 is amplified by the amplifier 578 and applied to the PZT 2 via the electrode plate 514 (connecting portion 532). Since PZT1 and PZT2 have the same configuration, the amplification factors of the amplifiers 576 and 578 are the same.

The PZT 3 and the voltage comparator 579 are connected via the electrode plate 516 (connecting portion 538). The PZT 4 and the voltage comparator 579 are connected via the electrode plate 516 (connecting portion 538).
The voltage comparator 579 is connected to the multiplier 574. Voltage comparator 579 compares the voltage generated in PZT3 and the voltage generated in PZT4, and outputs the difference to multiplier 574. The multiplier 574 sends the drive voltage from the drive power source 572 to the amplifier 576 with or without appropriately increasing or decreasing according to the received difference.
That is, when the voltage of PZT3 is larger than the voltage of PZT4, the voltage comparator 579 outputs a negative difference, and the multiplier 574 multiplies the driving voltage by a number greater than or equal to 0 and less than 1 according to the absolute value of the difference. .. The drive voltage applied to the amplifier 576 becomes smaller than the drive voltage applied to the amplifier 578 according to the absolute value of the difference. On the other hand, when the voltage of PZT3 is smaller than the voltage of PZT4, the voltage comparator 579 outputs a positive difference, and the multiplier 574 multiplies the drive voltage by a number of 1 or more according to the absolute value of the difference. The drive voltage applied to PZT1 via amplifier 576 is greater than the drive voltage applied to PZT2 via amplifier 578 in accordance with the absolute value of the difference.

In the ultrasonic vibration cutting device of the fifth mode, the PZT1 and PZT2 driven by applying the drive voltage via the amplifiers 576 and 578 generate axial vibration in the vibrator 502.
When flexural vibration occurs in the vibrator 502 during axial vibration, a strain having a magnitude corresponding to the flexural vibration occurs in the PZT3 and PZT4, and a voltage corresponding to the magnitude of the strain occurs.
The voltage of PZT3 thus generated and the voltage of PZT4 are compared in the voltage comparator 579, and the multiplier 574 multiplies the driving voltage of PZT1 by the coefficient corresponding to the difference between these voltages, thereby driving the voltage of PZT2. The drive voltage of PZT1 for PZT1 is adjusted.
That is, when a large distortion occurs on the PZT3 side due to flexural vibration, a voltage larger than that of PZT4 occurs in PZT3, the voltage comparator 579 outputs a negative difference, and the multiplier 574 outputs the drive voltage of PZT1 to the absolute difference. Decrease according to the value. Therefore, the PZT1 is driven by a driving voltage smaller than that of the PZT2, and the distortion toward the PZT3 side, which is the same as the PZT2 itself, is weakened more than the driving of the PZT2 and is actively canceled by the driving. .. On the other hand, when a large distortion occurs on the PZT4 side due to flexural vibration, a voltage larger than PZT3 occurs in PZT4, the voltage comparator 579 outputs a positive difference, and the multiplier 574 outputs the drive voltage of PZT1 to the absolute difference. Increase according to the value. Therefore, the PZT1 is driven with a driving voltage larger than that of the PZT2, and the distortion to the PZT4 side, which is on the lower side opposite to itself, is stronger than the driving of the PZT2 by the driving having the appropriate size, and the PZT1 is activated. Cancel.

The ultrasonic vibration cutting device of the fifth mode is a vibration generating piezoelectric element unit 510 including four driving piezoelectric elements 530, 530... (PZT1, PZT2), and four vibration detecting piezoelectric elements 534, 534. ..Vibration detection piezoelectric element unit 512 including (PZT3, PZT4), metal material 20 and metal block 22 sandwiching vibration generation piezoelectric element unit 510 and vibration detection piezoelectric element unit 512, and vibration generation piezoelectric element unit A vibrator 502 having 510 and a piezoelectric element unit 512 for vibration detection, and a bolt 24 for fastening the metal material 20 and the metal block 22, and a blade 4 connected to the vibrator 502 are provided for generating vibration. The piezoelectric element unit 510 generates a first-order axis vibration in the vibrator 502 when the driving voltage is applied by the driving voltage applying unit, and the driving voltage is generated by the multiplier 574 and the voltage comparator 579. It is adjusted according to the voltage generated in the vibration detecting piezoelectric elements 534, 534,... (PZT3, PZT4) in the flexural vibration other than the vibration.
Therefore, an undesired flexural vibration state is detected by the vibration detecting piezoelectric element unit 512 (PZT3, PZT4), and the drive voltage of the vibration generating piezoelectric element unit 510 (PZT1, PZT2) is changed according to the detected state. Feedback control is performed so as to cancel the flexural vibration. Therefore, unlike in the first or fourth mode, unnecessary flexural vibration is not passively dealt with (passive vibration isolation), but unnecessary flexural vibration is actively suppressed. (Active vibration isolation). As a result, not only in the case of normal ultrasonic vibration cutting, but also when using a tool with a high aspect ratio or when giving a high output vibration to the tool, it is possible to ensure unnecessary flexural vibration. Can be suppressed to provide extremely excellent cutting. Further, the drive voltage is feedback-controlled according to the state of the flexural vibration detected by the vibration detecting piezoelectric element unit 512 (PZT3, PZT4), so that flexures associated with various resonance modes are generated regardless of the order of the flexural vibration. Vibration can be suppressed appropriately.

Further, the vibration detecting piezoelectric elements 534, 534,... Are divided in the direction intersecting the central axis of the vibrator 502 (vertical direction). Therefore, the vibration detecting piezoelectric elements 534, 534,... Conform to the suppression of flexural vibration.
Further, the driving piezoelectric elements 530, 530... Are divided in the direction (vertical direction) intersecting the central axis of the vibrator 502. Therefore, the configuration is suitable when the unnecessary flexural vibration is actively canceled and suppressed by feedback control.
In addition, the driving piezoelectric elements 530, 530 and the vibration detecting piezoelectric elements 534, 534... Are polarized, and their polarization directions are parallel to the central axis of the vibrator 502. Therefore, in the feedback control, the configuration for applying desired vibration and suppressing unnecessary vibration becomes simple.

In the fifth mode, the same modification examples as at least any one of the first to fourth modes appropriately exist, and the following modification examples also exist.
The circuit configuration may be replaced with other elements equivalent to various elements of the circuit, the voltage for the PZT2 or both voltages may be adjusted, the coefficient may be output in the voltage comparator, the voltage comparator may be used. It may be modified in various ways such as using a comparison multiplier in which a multiplier and a multiplier are integrated, adjusting a driving voltage by adjusting a magnification of an amplifier, and omitting an amplifier.
Further, in the vibration generating piezoelectric element unit, in a state where the polarization directions of the driving piezoelectric elements are opposite between PZT1 and PZT2, a driving voltage of opposite phase is applied to the electrode plate between PZT1 and the driving voltage is adjusted. It may be done.

[Sixth form]
FIG. 8A is a schematic diagram of the blade 4, the vibrator 602, and the circuit included in the ultrasonic vibration cutting device for food according to the sixth embodiment of the present invention, and FIG. 8B is a vibrator. It is a schematic diagram in the flexural vibration of 602.
The sixth mode is the same as the fifth mode except the configurations of the vibration detecting piezoelectric element unit, the vibration generating piezoelectric element unit, and the circuit. The same members and the like as those in the fifth embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted.

The piezoelectric element unit 611 including the four piezoelectric elements 631, 631... In the vibrator 602 of the sixth embodiment is the piezoelectric element unit 510 for vibration generation in the axial direction of the fifth embodiment and the piezoelectric element unit for vibration detection in the bending direction. It also has the role of 512.
The piezoelectric element unit 611 is configured similarly to the vibration generating piezoelectric element unit 510 or the vibration detecting piezoelectric element unit 512 of the fifth embodiment. That is, each of the piezoelectric elements 631, 631... Has a semi-circular shape, and two semi-circular electrode plates 617 are sandwiched between the two piezoelectric elements 631, 631, and are divided into upper and lower parts. Here, the lower two piezoelectric elements 631 and 631 are PZTα, and the upper two piezoelectric elements 631 and 631 are PZTβ.
The polarization directions of PZTα and PZTβ are the same direction, for example, the direction toward the electrode plate 617.
Each electrode plate 617 includes a connecting portion 639 that projects radially outward.
The front surface and the rear surface of the piezoelectric element unit 611 are grounded.

The drive/vibration isolation circuit 670 of the sixth embodiment includes a drive power source 572, a multiplier 574, amplifiers (AMP) 576 and 578, an arithmetic circuit 679, and current sensors CC1 and CC2. The circuit 670 also serves as a drive voltage applying unit and a drive voltage adjusting unit. More specifically, the drive power source 572 and the amplifiers (AMPs) 576 and 578 constitute a drive voltage applying unit, and a multiplier 574 and an arithmetic circuit 679 are provided. The current sensors CC1 and CC2 form drive voltage adjusting means. The drive voltage adjusting means may be considered to include PZTα, PZTβ, or the electrode plates 617 and 617, or may be considered to be configured to exclude the current sensors CC1 and CC2.
The drive power source 572 and PZTα are connected via an amplifier 578 and an electrode plate 617 (connecting portion 639). The AC drive voltage generated by the drive power supply 572 is amplified by the amplifier 578 and applied to the PZTα via the electrode plate 617 (connecting portion 639).
The drive power source 572 and PZTβ are connected via a multiplier 574, an amplifier 576, and an electrode plate 617 (connecting portion 639). The AC voltage generated by the driving power source 572 is passed through the multiplier 574, amplified by the amplifier 576, and applied to the PZTβ via the electrode plate 617 (connecting portion 639). Since PZTα and PZTβ have the same configuration, the amplification factors of the amplifiers 576 and 578 are the same.

Also, the current sensor CC1 is arranged to measure the current I ₁ (given to PZTα) that exits the amplifier 578, and the current I ₂ that exits the amplifier 576 (given to PZTβ) measures the current I _2. The sensor CC2 is arranged.
The current sensors CC1 and CC2 are connected to the arithmetic circuit 679 and output the measured currents I ₁ and I ₂ to the arithmetic circuit 679.
The arithmetic circuit 679 is connected to the multiplier 574. The arithmetic circuit 679 suppresses the drive current I _{2 of the} PZTβ (relative to the drive current I ₁ ) according to the difference (I ₁ −I ₂ ) between the received currents I ₁ and I ₂ , and increases the drive current I _2. The coefficient B is calculated so as to be maintained or maintained. The coefficient B is calculated by the following [Equation 1].
The coefficient B is output to the multiplier 574, and the multiplier 574 multiplies the received coefficient B by the drive voltage A from the drive power source 572 (A×B), and the drive voltage before amplification according to the result is the amplifier 576. Given to.

In the ultrasonic vibration cutting device according to the sixth embodiment, the drive voltages having the same voltage and the same phase are applied via the amplifiers 576 and 578, so that PZTα and PZTβ vibrate in the same manner, and axial vibration occurs in the vibrator 602. To do.
When there is no flexural vibration in the vibrator 602, the same stress is generated in PZTα and PZTβ, the impedances of the piezoelectric elements 631 and 631 (PZTα and PZTβ) are the same, and the current flowing into PZTα and PZTβ is the same. I ₁ and I ₂ are equal. At this time, the coefficient B becomes 1, and the voltage A to the amplifier 576 or the current I ₂ flowing into PZTβ is maintained.

When flexural vibration occurs in the vibrator 602 during shaft vibration, different stresses occur in PZTα and PZTβ, and the impedances differ from each other. Therefore, due to the influence of the impedance, the current I ₁ flowing into PZTα and the current I ₂ flowing into PZTβ are different from each other.
Then, the arithmetic circuit 679 calculates the coefficient B according to the difference between the currents I ₁ and I ₂ received from the current sensors CC1 and CC2, and the multiplier 574 receives the driving voltage A from the arithmetic circuit 679. The current I ₂ for driving is adjusted by multiplying by the coefficient B.
That is, when the current I ₂ is larger than the current I ₁ , the impedance of PZTβ is smaller than that of PZTα, and relatively large stress is applied to the PZTα side due to unnecessary flexural vibration (see FIG. 8( In the state of b)), the current I ₂ is adjusted to become smaller according to the difference between the currents I ₁ and I ₂ . PZTβ to which relatively small stress is applied weakens the shaft vibration by the amount that the driving current I ₂ becomes small, and the driving current I _{1 of} PZTα becomes relatively large and the shaft vibration of PZTα is strengthened. It will be. If the axial vibration of PZTα becomes relatively strong, the PZTα stressed by the flexural vibration will vibrate more than PZTβ, and the axial vibration will be canceled so that the flexural vibration is canceled.
On the other hand, when the current I ₂ current I ₁ is smaller than the impedance of PZTβ has become larger than the impedance of PZTarufa, since it takes relatively large stress in PZTβ side by unwanted flexural vibrations, current I ₂ Is adjusted to increase according to the difference between the currents I ₁ and I ₂ . PZTβ, to which a relatively large stress is applied, strengthens the shaft vibration with respect to PZTα by the increase in the driving current I ₂ and vibrates more than PZTα so that the flexural vibration is also canceled. Vibrate.
As described above, the circuit 670 performs feedback control regarding the negative feedback of the difference between the currents I ₁ and I _{2 with} respect to the currents I ₁ and I ₂ , and controls each drive voltage related to PZTα and PZTβ, thereby causing flexural vibration. Shaft vibration is continued in a state where is actively canceled.

Details of such control will be further described below with reference to FIGS. 8B and 9.
As schematically shown in FIG. 8B, at a certain moment during flexural vibration, PZTβ expands from the steady state and PZTα contracts from the steady state. At this time, opposite-phase electromotive forces are generated in PZTα and PZTβ, the apparent impedances differ between PZTα and PZTβ, and the flowing currents differ between PZTα and PZTβ. Such a phenomenon continues during flexural vibration. Therefore, when the flexural vibration is superimposed on the shaft vibration, the current of the difference in impedance due to the flexural vibration is superimposed on the current of the shaft vibration.
On the other hand, in the normal shaft vibration in which the flexural vibration does not occur, PZTα and PZTβ vibrate in the same phase, the impedances are equal, and the flowing currents are the same in PZTα and PZTβ.

FIG. 9 is a graph showing a current waveform, which is a graph relating to a simulation when flexural vibration occurs at a frequency of ½ of the axial vibration of the fundamental wave. The vertical axis represents the relative magnitude of current (when the amplitude of the curve E1 is 1), and the horizontal axis represents time.
In the figure, a curve E1 (thick solid line) is a current waveform for shaft vibration that should originally flow in PZTα and PZTβ, and a curve E2 (thin solid line) is a waveform of a current component related to electromotive force generated in PZTα by flexural vibration. The curve E3 (thin dotted line) is the current waveform actually flowing in PZTα, and the curve E4 (thick dotted line) is the current waveform actually flowing in PZTβ.
When the flexural vibration occurs, in PZTα, the current component shown by the curve E2 is superimposed on the original current shown by the curve E1, and the current shown by the curve E3 flows through PZTα.
On the other hand, the waveform of the current component related to the electromotive force generated in the PZTβ due to the flexural vibration becomes a curve of the opposite phase of the curve E2, and in the PZTβ, the original current shown by the curve E1 has the opposite phase of the curve E2. The indicated current component is superimposed, and the current indicated by the curve E4 flows through PZTβ.
As a result, an unbalanced current corresponding to the flexural vibration flows through PZTα and PZTβ, and axial vibration that cancels the flexural vibration occurs.

The ultrasonic vibration cutting device according to the sixth mode is a piezoelectric element unit 611 including four piezoelectric elements 631, 631,..., a metal material 20 and a metal block 22 that sandwich the piezoelectric element unit 611, a piezoelectric element unit 611, and a metal. A plurality of piezoelectric elements 631, 631,... Are provided with a vibrator 602 having a bolt 24 for fastening the material 20 and the metal block 22, and a blade 4 connected to the vibrator 602. Are arranged so as to be separated in the direction (vertical direction) intersecting with the central axis (upper PZTα, lower PZTβ), and the driving currents I ₁ , PZTα, PZTβ are respectively applied to the plurality of piezoelectric elements 631, 631. The flow of I ₂ causes axial vibration in the vibrator 602, and the drive current I ₂ changes in each of the plurality of piezoelectric elements 631, 631... (PZTα, PZTβ) due to flexural vibration other than axial vibration. is adjusted according to I _{1, I 2} of the difference _(I 1 -I _2).
Therefore, the undesired flexural vibration state is grasped by the difference I ₁ −I ₂ between the currents I ₁ and I ₂ detected by the current sensors CC1 and CC2 and calculated by the arithmetic circuit 679, and the piezoelectric elements 631 and 631 (PZTβ The drive current I ₂ of 1) is actively feedback-controlled so as to cancel the undesired flexural vibration (active vibration isolation). Therefore, not only in the case of normal ultrasonic vibration cutting, but also when using a tool with a high aspect ratio or when giving a high output vibration to the tool, unnecessary flexural vibration is surely suppressed. Thus, it is possible to provide extremely excellent cutting. In addition, the driving current I ₂ is feedback-controlled in accordance with the flexural vibration state grasped by the difference I ₁ −I ₂ between the currents I ₁ and I _{2 in} the piezoelectric element unit 611 (PZTα, PZTβ), so that the deflection It is possible to appropriately suppress the flexural vibration associated with various resonance modes regardless of the order of the vibration.

The piezoelectric elements 631, 631... Are polarized, and their polarization directions are parallel to the central axis of the vibrator 602 (front-back direction).
Therefore, in the feedback control, the configuration for applying desired vibration and suppressing unnecessary vibration becomes simple.

In the sixth mode, the same modification as at least one of the first mode to the fifth mode appropriately exists.
In particular, regarding the circuit configuration, the current for PZTα or both currents may be adjusted. Further, in the piezoelectric element unit, in the state where the polarization directions of the piezoelectric elements are opposite between PZTα and PZTβ, a drive current of opposite phase is applied to the electrode plate between PZTβ so that the drive current is adjusted. Is also good.
At least any two of the first to sixth aspects and their modifications may be combined appropriately.

1・・Ultrasonic vibration cutting device (ultrasonic vibration device), 2,202,302,402,502,602・・Vibrator, 4・・Cutting tool (tool) 10,410,510・・Piece for vibration generation Element unit (first piezoelectric element unit), 12, 212, 312... Piezoelectric element unit for vibration isolation (second piezoelectric element unit), 20... Metal material (conductor block), 22... Metal block (conductor block) , 24 ··· bolt (fastener), 30, 430, 530 · · driving piezoelectric element (first piezoelectric element), 34 · · vibration isolation piezoelectric element (second piezoelectric element), 50, 250, 260, 350 , 450.. Shunt circuit, 52, 252, 262, 352.. Inductor, 54, 254, 264, 354.. Resistance, 512.. Vibration detecting piezoelectric element unit (second piezoelectric element unit), 534.. Vibration Piezoelectric element for detection (second piezoelectric element), 611... Piezoelectric element unit, 631... Piezoelectric element.

Claims (9)

A first piezoelectric element unit including one or more first piezoelectric elements;
A second piezoelectric element unit including one or more second piezoelectric elements;
A pair of conductor blocks sandwiching the first piezoelectric element unit and the second piezoelectric element unit;
A fastener for fastening the first piezoelectric element unit, the second piezoelectric element unit, and the pair of conductor blocks;
A vibrator having
A tool connected to the oscillator,
A shunt circuit connected to the second piezoelectric element unit;
Is equipped with
The first piezoelectric element unit generates a predetermined vibration in the vibrator when a driving voltage is applied,
The ultrasonic vibration device, wherein the shunt circuit is set so as to electrically resonate with the capacitance indicated by the second piezoelectric element unit in flexural vibration other than the predetermined vibration. The ultrasonic vibration device according to claim 1, wherein the shunt circuit includes a series circuit of an inductor and a resistor. A first piezoelectric element unit including one or more first piezoelectric elements;
A second piezoelectric element unit including one or more second piezoelectric elements;
A pair of conductor blocks sandwiching the first piezoelectric element unit and the second piezoelectric element unit;
A fastener for fastening the first piezoelectric element unit, the second piezoelectric element unit, and the pair of conductor blocks;
A vibrator having
A tool connected to the oscillator,
Is equipped with
The first piezoelectric element unit generates a predetermined vibration in the vibrator when a driving voltage is applied,
The ultrasonic vibration device according to claim 1, wherein the driving voltage is adjusted according to a voltage generated in the second piezoelectric element in flexural vibration other than the predetermined vibration. The ultrasonic vibration device according to claim 1, wherein the second piezoelectric element is biased or divided in a direction intersecting with a central axis of the vibrator. 4. The second piezoelectric element is biased or divided in a plurality of directions that are different from each other in a direction intersecting with the central axis of the vibrator, and the second piezoelectric element is characterized by being divided. The ultrasonic vibration device according to. The ultrasonic vibration device according to claim 1, wherein the first piezoelectric element is biased or divided in a direction intersecting with the central axis of the vibrator. 7. The first piezoelectric element and the second piezoelectric element are polarized, and their polarization directions are parallel to the central axis of the vibrator. The ultrasonic vibration device according to any one of claims. A piezoelectric element unit including a plurality of piezoelectric elements,
A pair of conductor blocks sandwiching the piezoelectric element unit,
A fastener for fastening the piezoelectric element unit and the pair of conductor blocks,
A vibrator having
A tool connected to the oscillator,
Is equipped with
The plurality of piezoelectric elements are arranged so as to be separated in a direction intersecting with the central axis of the vibrator,
By causing a drive current to flow through each of the plurality of piezoelectric elements, a predetermined vibration is generated in the vibrator,
At least one drive current is adjusted according to a difference between currents respectively changed in the plurality of piezoelectric elements due to flexural vibration other than the predetermined vibration. 9. The ultrasonic vibration device according to claim 8, wherein the plurality of piezoelectric elements are polarized, and their polarization directions are parallel to the central axis of the vibrator.

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