KR100801281B1 - Nondestructive inspection device for detecting defect of multilayer piezo-actuator - Google Patents

Abstract

According to the present invention, in a non-destructive inspection apparatus for measuring a defect of a multilayer piezoelectric actuator having an external electrode in a state where a plurality of ceramic sheets including internal electrodes are stacked, impact energy is transmitted while impinging on the surface of the multilayer piezoelectric actuator. Impact ball; Induces the transfer direction of the impact ball so that the impact ball collides with the stacked piezoelectric actuator fixed to the specimen holder, and is installed above the specimen holder and supplies the kinetic energy by the up and down piston movement to the impact ball to stack the piezoelectric actuator. Ball guide means including a piston moving to impinge the surface; And measuring means electrically connected to an external electrode of the stacked piezoelectric actuator and converting the received electrical signal into a frequency characteristic when an electrical signal generated by the stacked piezoelectric actuator is received due to the impact energy of the impact ball. A nondestructive testing device for an actuator is provided. According to the non-destructive inspection device of the stacked piezoelectric actuator according to the present invention, it is possible to measure the internal defects without destroying the stacked piezoelectric actuators, and the structure thereof is simple, the measurement is simple, and the production cost and maintenance cost are reduced. do.

Stacked Piezo Actuators, Nondestructive Testing, Impact Balls, Frequency Characteristics, Defect Detection

Description

Nondestructive inspection device for detecting defect of multilayer piezo-actuator

The present invention relates to a non-destructive testing device for a stacked piezoelectric actuator, and more particularly, to a device for inspecting a defect on a stacked piezoelectric actuator having an external electrode in a state in which a plurality of ceramic sheets including an internal electrode are stacked in a non-destructive manner. It is about.

In general, the multilayer piezoelectric actuator is an actuator in which displacement is generated according to an input electric field. When electrical energy is turned over to each ceramic sheet constituting the multilayer piezoelectric actuator, displacement may occur due to shrinkage or relaxation. The number of sheets laminated and the amount of displacement become proportional to each other.

According to the stacked piezoelectric actuator, the micro displacement can be precisely controlled, the displacement generating force is high, and the responsiveness is excellent. The space telescope, the position control element of the high performance camera, the inkjet printer head, the camera phone, the swing-operated LCD image sensor It is applied to various fields such as piezoelectric fans, intelligent automobile parts, and intelligent robots.

The multilayer piezoelectric actuator as described above may be manufactured according to a cut-bond method or a tape casting method, but in general, a plurality of the ceramic sheets are printed after printing a metal electrode material on the ceramic sheet. It is manufactured by a tape-casting method of pressing and forming internal electrodes.

The stacked piezoelectric actuator may have a deterioration in displacement characteristics, reliability, and lifespan as defects occur during manufacturing or during operation. As a method of determining whether defects are caused by the defect, a method of measuring impedance using an impedance analyzer, A method of directly observing the inside by breaking the stacked piezoelectric actuator and a method of measuring displacement with respect to the stacked piezoelectric actuator have been proposed.

According to the impedance analyzer, not only is the equipment expensive, but physical defects of the stacked piezoelectric actuators can be detected, while internal defects which have an absolute influence on the displacement of the actuators are difficult to be determined.

In addition, according to the direct destruction method and the displacement measurement method, it is cumbersome to inspect or measure the displacement of the stacked piezoelectric actuators individually in order to determine whether there is a defect, and that normal actuators may be destroyed or damaged during the measurement process. In terms of inefficiency, there are many problems.

The present invention has been made to solve the above-described problems, it is possible to provide a non-destructive inspection device of a laminated piezoelectric actuator that can measure the internal defects in the state that the laminated piezoelectric actuator is not destroyed, as well as manufacturing and maintenance costs. Has its purpose.

The non-destructive inspection device for a multilayer piezoelectric actuator of the present invention for achieving the above object is a non-destructive inspection device for measuring a defect of a multilayer piezoelectric actuator having an external electrode in a state where a plurality of ceramic sheets containing internal electrodes are laminated. An impact ball for imparting impact energy while colliding with a surface of the stacked piezoelectric actuator; Induces the conveying direction of the impact ball so that the impact ball collides with the stacked piezoelectric actuator fixed to the specimen holder, installed above the specimen holder and supplying kinetic energy by vertical piston movement to the impact ball Ball guide means including a piston moving the impact ball to the surface of the stacked piezoelectric actuator; And measuring means electrically connected to an external electrode of the stacked piezoelectric actuator and converting the received electrical signal into a frequency characteristic when the electrical signal generated by the stacked piezoelectric actuator is received due to the impact energy of the impact ball. do.

In addition, the measuring means may be an oscilloscope.

The measuring means may be electrically connected to an external electrode of the stacked piezoelectric actuator to amplify the received electrical signal when the electrical signal generated by the stacked piezoelectric actuator is received due to the impact energy of the impact ball. amplifier; A filter which removes and outputs a noise component included in the received electrical signal when the electrical signal output from the amplifier is received; And an oscilloscope for converting and outputting an electrical signal output from the filter into a frequency characteristic.

The present invention may further include a computer for receiving the electrical signal converted into the frequency characteristic by the measuring means and storing the measured electrical signal as measurement data.

On the other hand, the piston movement method of the piston body, may be any one selected from pneumatic piston movement according to the air pressure, hydraulic piston movement according to the pressure of the oil, or solenoid valve-type piston movement according to the electric field applied to the coil. have.

In addition, the specimen holder is formed with a fixing groove to which the laminated piezoelectric actuator is fixed, the fixing groove is provided with an auxiliary support that is connected to the inner wall of the fixing groove and the spring inside the fixing groove and shrinkage of the groove width by the elasticity of the spring and Relaxation is possible and the stacked piezoelectric actuator may be elastically fixed in the fixing groove.

According to the non-destructive inspection device for a stacked piezoelectric actuator according to the present invention, the following effects are provided.

First, there is an advantage that the internal defect measurement in the state that the laminated piezoelectric actuator is not destroyed by using a method in which the impact ball falls and collides with the laminated piezoelectric actuator.

Secondly, as the impact ball collides with the stacked piezoelectric actuator, a variety of manual or automatic methods, including free fall, piston movement, pulley rotation, and inclined dropping of the automatically elevated impact ball, may be applied. The structure is simple, easy to measure and easy to manufacture, and manufacturing and maintenance costs can be reduced.

Third, by converting the electrical signal generated from the impact energy delivered to the stacked piezoelectric actuator in response to the impact of the impact ball into a frequency characteristic, defect measurement of the stacked piezoelectric actuator is possible, and the amplification of the weak electrical signal and the noise component are removed. The advantage is that a clear interpretation of the signal is possible.

Fourth, the detected data can be stored in a separate computer to store, analyze and compare the measured data.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. It should be interpreted as meanings and concepts corresponding to the technical idea of the present invention based on the principle of definition.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

As shown in FIG. 6, the stacked piezoelectric actuator 10 having two external electrodes 13 to which a positive electrode and a negative electrode are applied in a state where a plurality of ceramic sheets 11 including the internal electrodes 12 are stacked. The present invention relates to a non-destructive inspection device for measuring internal defects.

1A to 1B are schematic views of a non-destructive inspection device of a stacked piezoelectric actuator according to a first embodiment of the present invention, and FIGS. 2 to 4 are non-destructive inspection devices according to a second embodiment to a fourth embodiment of the present invention. Schematic diagram of.

According to the non-destructive inspection device (100, 200, 300, 400) of the stacked piezoelectric actuator of the present invention, the impact ball 110, the ball guide means 120 and the measuring means 130.

The impact ball 110 is a ball that transmits the impact energy while colliding with the surface of the stacked piezoelectric actuator 10, it is preferably made of a rigid material so that the inelastic impact on the stacked piezoelectric actuator 10 is made.

The ball guide means (120, 220, 320, 420) is a part for inducing the conveying direction of the impact ball 110 so that the impact ball 110 collides with the stacked piezoelectric actuator 10 is fixed to the specimen holder 140, It may be configured with various embodiments shown in 1a to 4.

The measuring means 130 is electrically connected to an external electrode 13 of the stacked piezoelectric actuator 10, and the electrical signal generated by the stacked piezoelectric actuator 10 due to the impact energy of the impact ball 110 is When received, the part converts the received electric signal into a frequency characteristic and outputs the frequency characteristic.

According to the present invention as described above, when the electrical signal is generated according to the time change of the current and voltage at the external electrode 13 by the impact energy delivered to the stacked piezoelectric actuator 10, the generated electrical signal is frequency characteristics The defect measurement of the laminated piezoelectric actuator 10 can be performed by converting to.

The measuring means 130 may be an oscilloscope 131 as shown in FIGS. 1A to 1B, and the amplifier 132, the filter 133, and the oscilloscope 131 as shown in FIGS. 2 to 4. It may include.

The amplifier 132 is electrically connected to an external electrode 13 of the stacked piezoelectric actuator 10 to receive an electrical signal generated by the stacked piezoelectric actuator 10 due to the impact energy of the impact ball 110. When amplified, the received electrical signal is output.

When the electric signal output from the amplifier 132 is received, the filter 133 may remove and output a noise component included in the received electric signal.

The oscilloscope 131 may convert an electrical signal output from the filter 133 into a frequency characteristic and output the frequency characteristic.

As described above, since the filter 133 and the amplifier 132 are included in the measuring means 130, amplification of the weakly received electric signal is possible, as well as a clear analysis of the received signal by removing noise components. This has the advantage of being possible.

Here, the configuration of the measuring means 130 shown in FIGS. 1A to 1B may be applied to the measuring means 130 of FIGS. 2 to 4, and conversely, the configuration of the measuring means 130 shown in FIGS. 2 to 4. It is also applicable to the measuring means 130 of Figs. 1A to 1B.

On the other hand, the non-destructive testing device (100, 200, 300, 400) of the stacked piezoelectric actuator according to the present invention may further include a computer 150 connected to the measuring means 130, according to the computer 150 according to the measuring means 130 It is possible to store, analyze and compare the measured data by receiving the electrical signal converted into frequency characteristics and storing it as data.

Meanwhile, as shown in FIGS. 1A to 4, the present invention may be variously modified in the first to fourth embodiments according to the structure of the ball guide means 120.

First, according to the non-destructive inspection device 100 of the stacked piezoelectric actuator according to the first embodiment of the present invention shown in Figures 1a to 1b, the ball guide means 120 is through the impact ball 110 is passed through It includes a ball induction pipe 121 to guide the free fall of the impact ball 110 by being installed vertically above the specimen fixing stand 140 in the state formed.

The ball induction pipe 121 is installed in the form of the outer periphery surrounded by at least three pillars while being installed vertically above the specimen fixture 140 as shown in Figure 1b, in the ball induction pipe 121 of Figure 1a In comparison, while the impact ball 110 falls, the area in contact with the inner wall of the ball induction pipe 121 may be reduced, and the frictional resistance during the drop may be reduced.

On the other hand, according to the non-destructive inspection device 200 of the stacked piezoelectric actuator according to the second embodiment of the present invention shown in Figure 2, the ball guide means 220 is installed above the specimen fixing plate 140, Supplying the kinetic energy by the up and down piston movement to the impact ball 110 includes a piston moving body 221 to impinge the impact ball 110 on the surface of the stacked piezoelectric actuator (10).

The piston movement method of the piston movement body 221 is a pneumatic piston movement according to the air pressure, a hydraulic piston movement according to the pressure of the oil, or a solenoid valve-type piston movement according to the electric field direction applied to the coil This can be applied.

 On the other hand, according to the non-destructive inspection device 300 of the stacked piezoelectric actuator according to the third embodiment of the present invention shown in Figure 3, the ball guide means 320 is a pulley 321, pulley belt 322 and the driving unit ( 323).

The pulley 321 may be rotated forward and reverse in the circumferential direction, and may be installed at least one above the specimen holder 140.

The pulley belt 322 is fixed to the one end of the impact ball 110, is installed along the circumference of the pulley 321.

The driving unit 323 is a stacking piezoelectric actuator 10 to the impact ball 110 fixed to one end of the pulley belt 322 while the other end of the pulley belt 322 is connected to the forward or reverse rotation Can fall and collide with the surface.

Here, the driving unit 323 may return the impact ball 110 to the collision standby state by the rotation operation in the direction opposite to the direction in which the impact ball 110 falls.

On the other hand, the driving unit 323 is capable of adjusting the speed of the forward or reverse rotation can be adjusted to the magnitude of the impact energy delivered to the stacked piezoelectric actuator 10 according to the dropping speed of the impact ball 110. In this case, the rotational speed of the driving unit 323 may be adjusted within the limit that the stacked piezoelectric actuator 10 is not destroyed.

The driving unit 323 may be implemented by a driving motor, but the driving means is not limited thereto, and various modifications may be made to other means capable of forward or reverse rotation.

According to the third embodiment of the present invention as described above, the convenience of defect detection is of course improved by applying the automatic collision method by the driving unit 323 instead of the manual collision method as the first embodiment. The drop speed and impact energy of the impact ball 110 according to the rotational speed control of the driving unit 323 can be adjusted.

Next, a non-destructive inspection device 400 for a stacked piezoelectric actuator according to a fourth embodiment of the present invention shown in FIG. 4 will be described in detail.

The ball guide means 420 according to the fourth embodiment of the present invention may include a ball elevating body 421 and the inclined line 428, wherein the laminated piezoelectric actuator 10 is a specimen holder 140 is fixed It is preferable that the surface of) forms an angle of inclination relative to the horizontal plane such that the surface of the impact ball 110 falls at a predetermined angle of inclination of approximately 90 °.

Meanwhile, the ball lifting body 421 included in the ball guide means 420 may include a main body 422, a ball transfer line 423, and a rotating plate 424.

Here, the main body 422 is a cylindrical body formed with an outlet 426 and the inlet 427 is the entrance and exit of the impact ball 110 on one side of the upper and lower.

The ball transfer line 423 is installed in a spiral extending from the inlet 427 toward the outlet 426 along the inner wall of the main body 422 and the impact ball 110 is transferred.

In addition, the rotating plate 424 is rotated by the driving of the motor 425 in a state installed vertically inside the ball transfer line 423 of the main body 422, the impact ball 110 to the ball transfer line 423 ) Is a part having a driving force to move upward along.

The rotating plate 424 is preferably formed with a protrusion 424a on which one side of the impact ball 110 is supported so that the impact ball 110 does not fall off from the ball transfer line 423. .

The inclined line 428 is installed with a predetermined inclination angle between the ball lifting body 421 and the specimen fixing table 140, the impact ball is separated from the outlet 426 of the ball lifting body 421 ( 110 is a portion to guide the downward transfer to the stacked piezoelectric actuator 10 is fixed to the specimen holder (140).

On the other hand, the ball guide means 400 applied to the fourth embodiment of the present invention may further include a tilt control member 429 and the ball return line 430.

The inclined regulator 429 is a portion for adjusting the predetermined angle of the specimen fixing table 140 and the predetermined inclination of the inclined line 428 so that the falling speed and the magnitude of the impact energy of the impact ball 110 is adjusted, respectively. As such, the angle of the surface of the specimen holder 140 and the longitudinal direction of the inclined line 428 is maintained at approximately 90 ° such that the impact ball 110 collides substantially perpendicularly to the surface of the stacked piezoelectric actuator 10. It is preferable to adjust so that.

The inclination control body 429 may be applied to the automatic adjustment method according to the manual adjustment or the drive of a separate control unit, but the inclination adjustment method is not limited to this and can be modified to various embodiments in which the inclination angle is adjusted.

 On the other hand, the ball return line 430 is installed between the inlet 427 of the ball lifting body 421 and the specimen fixing stand 140, the impact ball dropped after the impact on the stacked piezoelectric actuator 10 ( As the portion 110 is guided back to the inlet 427 of the ball lifting body 421, as shown in Figure 4 can be applied to the inclined transfer line form or a moving method by a conveyor.

In addition, in the present invention, in order to prevent the separation of the impact ball 110 is dropped more than a predetermined area, the separation prevention means (not shown) including a guide having a predetermined height in the vertical direction is around the specimen fixing stand 140 It is preferable to install.

Referring to the procedure of the process according to the fourth embodiment of the present invention as described above in detail.

First, the impact ball 110 is automatically transferred to the outlet 426 along the ball transfer line 423 through the rotation of the rotating plate 424.

Second, the impact ball 110 transferred to the outlet 426 is separated through the outlet 426 and then transported downward in the inclined line 428, the stacked piezoelectric actuator located on the specimen holder 140 ( 10) will hit the surface.

Third, the impact ball 110 collided flows back into the inlet 427 of the ball lifting body 421 through the ball return line 430.

The impact ball 110 introduced again through the above process is switched to the standby state, so that the entire measurement process may be automated.

By controlling the driving period of the rotating plate 424 of the constituent means of the fourth embodiment according to the cycle in which the stacked piezoelectric actuator 10, which is the test subject, is tested through the above process, the experiment according to the present invention is not continuous. Can be realized.

Of course, it is obvious that the measurement result according to the present invention may be configured to be stored in a storage terminal such as the computer 150 in response to the above cycle.

According to the first to fourth embodiments of the present invention as described above, the internal defects can be measured without destroying the stacked piezoelectric actuators, as well as the structure is simple and easy to manufacture. And manufacturing and maintenance costs can be reduced.

On the other hand, Figure 5 is a cross-sectional view showing a specimen holder of the present invention.

As shown in the drawing, the specimen holder 140 applied to the first to fourth embodiments of the present invention may have a fixing groove 141 to which the stacked piezoelectric actuator is fixed.

Here, an auxiliary support 142 connected to the inner wall of the fixing groove 141 and the spring 143 may be provided inside the fixing groove 141 of the specimen holder 140, wherein the spring 143 of the The stackable piezoelectric actuator 10 may be elastically fixed inside the fixing groove 141 as the groove width may be contracted and relaxed by elasticity.

Here, the groove width refers to the width of the portion to which the stacked piezoelectric actuator 10 is coupled, and the auxiliary support 142 is elastically supported with the inner wall of the fixing groove 141, so that the stacked piezoelectric actuator 10 Is elastically supported in the fixing groove 141 is coupled.

The spring 143 mentioned in the above configuration is a constituent means for performing a function of allowing the auxiliary support 142 to relax and contract while having an elastic force, and thus, any spring having a predetermined elastic force capable of performing the above function. It is apparent that the means can also be replaced, it is obvious that the configuration required by the claims in the present invention can not be limited to the spring (143).

Hereinafter, an example of a defect detection result using the non-destructive inspection device 100 of the stacked piezoelectric actuator according to the first embodiment of the present invention will be described.

The weight of the impact ball 110 used in this test is 0.44g, the height of free fall is 10cm, at this time the impact energy of the impact ball 110 is 0.4 × 10 ^-3 J.

6 is a schematic diagram of a general stacked piezoelectric actuator without internal defects, and FIG. 7 is a schematic diagram of a stacked piezoelectric actuator with internal defects. 8 and 9 are graphs of temporal characteristics according to non-destructive testing of the actuators of FIGS. 6 and 7, and FIGS. 10 and 11 are graphs of respective frequency characteristics of FIGS. 8 and 9.

As shown in FIG. 7, types of internal defects that cause displacement characteristics, reliability, and lifespan deterioration of the stacked piezoelectric actuator 10 include breakage of internal electrodes (A), pore generation of ceramic sheets (B), It may be a crack generation (C) of the internal electrode.

First, referring to the non-destructive test result of the multilayer piezoelectric actuator 10 without internal defects of FIG. 6, as shown in FIG. 8, the amplitude of the received electric signal gradually decreases with time, and at the same time, the In FIG. 10, in which the temporal characteristic is converted into the frequency characteristic, the normal frequency characteristic in which a predetermined amplitude is clearly present at a specific frequency is shown.

However, looking at the non-destructive test results for the multilayered piezoelectric actuator 10 having the internal defect of FIG. 7, as shown in FIG. 9, the amplitude of the received electrical signal is unstablely decreased with time, and this temporal characteristic is not shown. Referring to FIG. 11 converted to a frequency characteristic, a signal having an abnormal frequency characteristic having a weak amplitude is output, and the characteristic is distinguished when compared with FIG. 10 in a normal case without internal defects.

As described above, according to the present invention, the piezoelectric actuator 10 according to the configuration of the present invention is converted by converting an electrical signal generated from the impact energy transmitted from the stacked piezoelectric actuator 10 into a frequency characteristic according to the impact of the impact ball 110. It is possible to standardize the frequency characteristics according to the presence or absence of defects that may occur in

By performing the experiment according to the present invention of the stacked piezoelectric actuator 10 on the basis of the standardized defect data, data about the presence or absence of defects and types of defects can be automatically computed, and thus the processing speed and accuracy of the defects. This can be further improved.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is described by the person of ordinary skill in the art to which the present invention pertains. Various modifications and variations are possible without departing from the scope of the appended claims.

1A to 1B are schematic views of a non-destructive inspection device of a stacked piezoelectric actuator according to a first embodiment of the present invention,

2 is a schematic diagram of a non-destructive inspection device according to a second embodiment of the present invention;

3 is a schematic view of a non-destructive inspection device according to a third embodiment of the present invention,

4 is a schematic diagram of a non-destructive inspection device according to a fourth embodiment of the present invention;

5 is a cross-sectional view showing a specimen holder of the present invention,

6 is a schematic diagram of a general stacked piezoelectric actuator without internal defects,

7 is a schematic diagram of a stacked piezoelectric actuator with an internal defect,

8 is a graph of a time characteristic according to the non-destructive test of the actuator of FIG.

9 is a graph of the temporal characteristics according to the non-destructive test of the actuator of FIG.

10 is a frequency characteristic graph of FIG.

11 is a graph of frequency characteristics of FIG. 9.

<Explanation of symbols for the main parts of the drawings>

10 ... Laminated Piezo Actuators 11 ... Ceramic Sheets

12 Internal electrodes 13 External electrodes

100,200,300,400 ... Non-destructive testing device for laminated piezo actuator

110 ... Impact Ball 120,220,320,420

121 Induction pipe 130 Measuring means

131 Oscilloscope 132 Amplifiers

133 filter 140 specimen holder

141.Retaining groove 142 Auxiliary support

143 ... Spring 221 ... Piston Body

321 Pulley 322 Pulley Belt

323 Driving part 421 Ball body

422 Body 423 Ball Feed Line

424 ... Spinner 425 ... Motor

426 ... Exit 427 ... Entrance

428 Slope Line 429 Slope Regulator

430 Ball return line 150 Computer

Claims (6)

A non-destructive inspection device for measuring a defect of a multilayer piezoelectric actuator having an external electrode in a state where a plurality of ceramic sheets including an internal electrode are laminated, An impact ball that transmits impact energy while colliding with a surface of the stacked piezoelectric actuator; Induces the conveying direction of the impact ball so that the impact ball collides with the stacked piezoelectric actuator fixed to the specimen holder, installed above the specimen holder and supplying kinetic energy by vertical piston movement to the impact ball Ball guide means including a piston moving the impact ball to the surface of the stacked piezoelectric actuator; And And measuring means electrically connected to an external electrode of the stacked piezoelectric actuator and converting the received electrical signal into a frequency characteristic when the electrical signal generated by the stacked piezoelectric actuator is received due to the impact energy of the impact ball. Non-destructive testing device for stacked piezo actuators. The method of claim 1, wherein the measuring means, Non-destructive testing device for a stacked piezoelectric actuator, characterized in that it is an oscilloscope. The method of claim 1, wherein the measuring means, An amplifier electrically connected to an external electrode of the stacked piezoelectric actuator and amplifying the received electrical signal when the electrical signal generated by the stacked piezoelectric actuator is received due to the impact energy of the impact ball; A filter which removes and outputs a noise component included in the received electrical signal when the electrical signal output from the amplifier is received; And And an oscilloscope for converting the electrical signal output from the filter into a frequency characteristic and outputting the oscilloscope. The method according to any one of claims 1 to 3, And a computer for receiving the electrical signal converted into the frequency characteristic from the measuring means and storing the measured electrical signal as measurement data. The method of claim 1, wherein the piston movement of the piston body, Non-destructive inspection device for a stacked piezoelectric actuator, characterized in that the pneumatic piston movement according to the air pressure, the hydraulic piston movement according to the pressure of the oil, or the solenoid valve piston movement according to the electric field applied to the coil. The method of claim 1, wherein the specimen holder, A fixing groove to which the stacked piezoelectric actuator is fixed is formed, Inside the fixing groove is provided with an auxiliary support connected to the inner wall of the fixing groove and the spring is possible to shrink and relax the groove width due to the elasticity of the spring and the laminated piezoelectric actuator is fixed to the inside of the fixing groove elastically Non-destructive inspection device for laminated piezoelectric actuators.

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