JP2943438B2 - Driving method of linear array ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic scanning type ultrasonic inspection apparatus, which can scan a wide range of an object at high speed.
The present invention relates to a method for driving a linear array ultrasonic probe in which a plurality of unit probes are linearly arranged.

[0002]

2. Description of the Related Art By using an ultrasonic probe, it is possible to easily detect a defect of a steel material and measure a thickness of the steel material. If the specimen, such as steel, has a large area,
By using a linear array ultrasonic probe in which a plurality of unit probes are linearly arranged and an electronic scanning ultrasonic inspection device, it is possible to detect defects and plate thickness quickly over a wide area of the object surface. Measurement can be performed. That is, since the unit probes to be excited by the linear array ultrasonic probe are only electrically switched in order, the inspection speed is reduced as compared with the case where the probe is mechanically moved. Can rise significantly.

The linear array ultrasonic probe focuses and deflects ultrasonic waves output from the transducers of each unit probe by changing the timing of exciting the transducers of each unit probe. For this purpose, there are a linear array ultrasonic probe in which the length of each transducer is set short, and a linear array ultrasonic probe in which the length of each transducer is set long to scan a wide range.

A linear array ultrasonic probe in which the length of the transducer of the unit probe is set to be long is configured, for example, as shown in FIG. That is, the linear array ultrasonic probe 1 is configured by arranging a plurality of unit probes 2 in a straight line and connecting the unit probes 2 with each other by, for example, an adhesive.

In each unit probe 2, a vibrator 8 whose both surfaces are sandwiched between electrode plates 6, 7 is provided between a matching layer 4, which is in contact with a subject 3 such as a steel plate, and a back layer 5. It is interposed. Then, a ground wire 10 and a signal wire 11 are connected from the electronic scanning ultrasonic inspection apparatus 9 to each of the electrode plates 6 and 7 of each unit probe 2.

At least one or more pulse generators and receiving circuits are incorporated in the electronic scanning ultrasonic inspection apparatus 9, and each of the unit probes 2 constituting the linear array ultrasonic probe 1 is provided. A pulse signal is sequentially sent to each of the electrode plates 6 and 7, and each ultrasonic wave is made to enter the subject 3 from each transducer 8. Each reflected wave of each ultrasonic wave reflected on the defect or the bottom surface in the subject 3 is received by the vibrator 8, converted into an electric signal, and input to a receiving circuit in the electronic scanning ultrasonic inspection apparatus 9. Therefore, the position of each defect and the position of the bottom surface are confirmed from the echo contained in each received signal by this receiving circuit.

As described above, the linear array ultrasonic probe 1
By using the electronic scanning ultrasonic inspection apparatus 9, the presence or absence of defects over a wide range of the subject 3 can be determined without moving the position of the linear array ultrasonic probe 1 attached to the subject 3. The distance (plate thickness) between the position and the bottom surface can be measured in a short time.

[0008]

However, the linear array ultrasonic probe 1 as shown in FIG. 7 has the following problems to be solved.

That is, in an inspection method in which a pulse signal is sequentially applied to each unit probe 2 constituting the linear array ultrasonic probe 1 by the electronic scanning ultrasonic inspection apparatus 9 to observe an echo, Each unit probe 2 constituting the linear array ultrasonic probe 1 must naturally have the same detection sensitivity characteristics.

However, as shown in FIG.
Is composed of a matching layer 4, an electrode plate 6, a vibrator 8, an electrode plate 9, and a back layer 5. When these are assembled into one unit probe 2, an epoxy adhesive is used to fix the electrodes 6 and 7 to the matching layer 4 and the back layer 5. On the other hand, a piezoelectric ceramic is generally used as the vibrator 8. The acoustic impedance of this piezoelectric ceramic is, for example, 30 × 10 ⁶ Kg / m ² s. On the other hand, the acoustic impedance of epoxy adhesive is
For example, 3.0 × 10 ⁶ Kg / m ² s, and there is a difference of about 10 times when comparing the two. As a result, the ultrasonic waves are reflected by the adhesive layer, and the transmitted or received ultrasonic waveform is disturbed.

Therefore, it is necessary to adjust the influence of each adhesive layer on each unit probe 2 under the same condition. Therefore,
It is necessary to set the thickness of the adhesive uniformly and thinly over all the unit probes 2. However, it is very difficult in terms of manufacturing technology to make the thickness of the adhesive layer in each unit probe 2 uniform over all the unit probes 2. As a result, it is difficult to control the detection sensitivity and frequency characteristics of each unit probe 2 to constant values.

In order to solve such inconvenience, it is effective to use a method of manufacturing a linear array ultrasonic probe having a short unit probe. That is, JP-A-55-743
FIG. 8A shows a linear array ultrasonic probe 12 shown in FIG.

In the linear array ultrasonic probe 12, first, a back layer 13 having the same shape as the entire shape of the linear array ultrasonic probe 12, and an electrode plate 14 having the same shape as the back layer 13 , Piezoelectric ceramics (vibrator)
15, the electrode plate 16, and the matching layer 17 are assembled using the above-mentioned ordinary epoxy adhesive. Then, after the epoxy-based adhesive solidifies, a cut 18 extending from the matching layer 17 to the piezoelectric ceramics (vibrator) 15 is formed to form a unit probe as illustrated.

In the integrated linear array ultrasonic probe 12 configured as described above, since the step of applying the epoxy-based adhesive is performed only once, it can be determined that the epoxy adhesive is applied to a uniform thickness. Therefore, it can be considered that the thickness of the epoxy adhesive in each unit probe divided by the cut 18 is uniform over all the unit probes. Therefore, FIG.
Can solve the problems of the linear array ultrasonic probe 1 shown in FIG.

However, in each of the linear array ultrasonic probes 1 and 12 shown in FIG. 8A and FIG.
Since each unit probe has a rectangular shape, the vibrating directions of the vibrators 8 and 15 vibrate not only in the original thickness direction but also in the horizontal direction (lateral direction), and the vibrations are caused by sliding vibration in the horizontal direction. I do. Therefore, the vibration in the direction other than the thickness direction adversely affects the vibration in the thickness direction, so that the wave number of the ultrasonic pulse increases, the time resolution deteriorates, and the spatial resolution of the defect in the ultrasonic traveling direction decreases.

A first method of suppressing such horizontal (lateral) vibration is to set the ratio of the transducer length in the direction orthogonal to the probe arrangement direction to the arrangement direction length to the thickness. It is to select the optimal value. However, in this case, it is difficult to manufacture a probe having an arbitrary size at an arbitrary frequency.

As a second method for suppressing vibration, a linear array ultrasonic probe 19 as shown in FIG. 8B has been proposed (Japanese Patent Laid-Open No. 63-209634). In this linear array ultrasonic probe 19,
In order to suppress horizontal vibration, each of the cuts 18 described above is used.
In addition, a number of sub-cuts 21 are formed between the cuts 18. However, as shown in FIG. 8B, if a large number of cuts 18 and 21 are carved, the configuration of the entire linear array ultrasonic probe 19 becomes complicated, the manufacturing cost increases, and the degree of design freedom increases. Be constrained.

Further, in the integrated linear array ultrasonic probe described above, the maximum value of the length of each unit probe currently developed is about 3 mm. If the length of each unit probe is short, it is necessary to increase the number of channels (the number of unit probes) in order to scan a wide range.
The configuration of the entire linear array ultrasonic probe is complicated, and the manufacturing cost is greatly increased.

When a new linear array ultrasonic probe is manufactured, each unit probe has dimensional restrictions as described above, and the design is complicated, and the development cost and the development period are reduced. However, there is a concern that this will be prolonged.

The present invention has been made in view of such circumstances, and the inspection area of each unit probe can be expanded with a simple configuration, and a wide area of a subject can be inspected with a small number of unit probes. It is another object of the present invention to provide a method of driving a linear array ultrasonic probe capable of scanning a wide range of an object at high speed and with high accuracy with a small number of channels in combination with an electronic scanning ultrasonic inspection apparatus.

[0021]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a single vibrator plate made of a piezoelectric polymer material and a linear arrangement on the upper surface of the vibrator plate. A plurality of electrode plates, a back layer commonly covering the upper surfaces of the respective electrode plates, one common electrode plate attached to the lower surface of the vibrator plate, and a matching layer attached to the lower surface of the common electrode plate; A method for driving a linear array ultrasonic probe in which a plurality of unit probes corresponding to the respective electrode plates are linearly arranged, wherein the plurality of linearly arranged unit probes are arranged. A probe is simultaneously excited and received simultaneously for a plurality of unit probes adjacent in the arrangement direction, and a combination of the plurality of unit probes simultaneously excited and simultaneously received is arranged in the arrangement direction by one unit probe. And move it to

[0022]

[0023]

[0024]

[0025]

In the linear array ultrasonic probe used in the driving method of the linear array ultrasonic probe thus configured, a piezoelectric polymer material is used as a vibrator. The acoustic impedance of this piezoelectric polymer material is about 4.51 × 10 ⁶ Kg / m ² s, which is almost the same as the acoustic impedance of the epoxy adhesive described above.
Therefore, even if the thickness of the adhesive layer slightly varies between the unit probes, the effect on each unit probe is substantially the same. That is, it is possible to absorb a variation in the working accuracy between the unit probes due to the bonding process.

Since the piezoelectric polymer material has a smaller elastic coefficient than conventional piezoelectric ceramics, unnecessary vibrations such as lateral vibration and sliding vibration hardly occur. Therefore, each unit probe can be set to an arbitrary shape without requiring a large number of cuts as shown in FIG. 8B. Therefore, a unit probe having a wide inspection area can be easily realized.

Further, as described above, the piezoelectric polymer material hardly generates lateral vibration, sliding vibration, etc. other than the vibration in the original thickness direction. Therefore, since it has almost no effect on the unit transducers adjacent in the lateral direction, the transducer plate made of the piezoelectric polymer material can be applied to all unit transducers without being divided for each unit probe. A common one across
It is possible to use two vibrator plates.

As a result, the electrode plate and the matching layer located on the object side of the vibrator plate can be formed by one electrode and the matching layer without dividing. That is, the manufacturing cost can be reduced, and the fluctuation in the detection accuracy due to the dimensional accuracy between the unit probes can be suppressed.

[0029]

Further, since the ultrasonic beam transmitted by one unit probe is narrow, the defect detection sensitivity at the position between the ultrasonic beams is reduced. Therefore, in the present invention, simultaneous excitation and simultaneous reception are performed on a plurality of unit probes adjacent in the arrangement direction. Further, the combination of the plurality of unit probes that are simultaneously excited and simultaneously received is moved in the arrangement direction by one unit probe. Therefore, a decrease in defect detection sensitivity at a position between the ultrasonic beams is prevented, and the overall detection accuracy is improved.

[0031]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a schematic configuration of a linear array ultrasonic probe used in the driving method of the embodiment. The linear array ultrasonic probe 22 of this embodiment is composed of 32 unit probes arranged linearly.

In FIG. 1, each unit probe has a width of 6 mm and a length of 4 mm. Therefore, the overall size is 6mm x
It has a shape of 128 mm. Then, one common electrode plate 26 is attached to the upper surface of the matching layer 27 whose lower surface is in contact with the subject 3 by, for example, an epoxy-based adhesive.
One vibrator plate 25 is mounted above the common electrode plate 26 so as to cover the common electrode plate 26. The vibrator plate 25 is formed of a piezoelectric polymer material represented by, for example, P (VDF-TrFE).

On the upper surface of the vibrator plate 25, 32 electrode plates 24 corresponding to each unit probe are stuck at a minute interval linearly by, for example, an epoxy-based adhesive. Each electrode plate 24 is formed of a copper plate and has a shape of a width of 6 mm and a length of 4 mm. The back layer 23 is attached so as to cover the upper surfaces of the 32 electrode plates 24 in common. The back layer 23 is formed of, for example, bakelite, and has a thickness of ４ of the wavelength λ of the ultrasonic wave used in the linear array probe 22.

FIG. 2 shows the linear array ultrasonic probe 2
FIG. 2 is a block diagram illustrating a schematic configuration of the electronic scanning ultrasonic inspection apparatus 28 in a case where a defect existing in a subject 3 such as a steel plate is detected using the electronic scanning ultrasonic inspection apparatus 2 and the electronic scanning ultrasonic inspection apparatus 28.

In this electronic scanning ultrasonic inspection apparatus 28, 32 pulse generators 29, 32 amplifiers 30 as receiving circuits and 32 detectors 31 are incorporated. Each channel from No. 1 to No. 32 is shown in FIG.
Is connected to each unit probe 32 of the linear array ultrasonic probe 22. The scanning channel control device 33 includes:
A plurality of channels to be excited at the same time are selected, and a drive signal is transmitted to each of the selected pulse generators 29 via the pulse generator control circuit. Each of the selected pulse generators 29 outputs a pulse signal based on the drive signal.

The pulse signal output from the pulse generator 29 is applied between the electrode plate 24 and the common electrode plate 26 of the unit probe 32 of the corresponding channel of the linear array ultrasonic probe 22. As a result, a portion of the vibrator plate 25 sandwiched between the corresponding electrode plate 24 and the common electrode plate 26 vibrates to generate pulsed ultrasonic waves, which are incident on the subject 3 via the matching layer 27. You. The pulse-like ultrasonic wave incident on the subject 3 is reflected by a defect existing inside or on the surface, is received by the vibrator plate 25 as an echo, is converted into an electric signal, and is converted into an electronic scanning ultrasonic inspection apparatus 28. Are input to the amplifier 30 of the corresponding channel.

The received signal amplified by the amplifier 30 is subjected to envelope detection by the next detector 31. The envelope detection signal is input to the received wave synthesizer 35. The received wave synthesizer 35 synthesizes a signal of each detection waveform of the envelope detection signal output from the detector 31 of each channel previously specified by the scanning channel control unit 33, that is, each echo waveform corresponding to a defect. It is transmitted to the reception wave display unit 36. For example, a received wave display 36, such as a CRT display device, displays each echo waveform caused by the input defect. Next, three unit probes 32
The control procedure of the scanning channel control unit 33 will be described with an example of simultaneous excitation and simultaneous reception.

First, the first to third pulse generators 29 are selected, and the first unit probe 32 to the third unit probe 32 of the linear array ultrasonic probe 22 are selected. Pulse ultrasonic waves are output from the three unit probes 32 up to the same timing. Then, the received wave synthesizer 35 combines the echoes output from the three detectors 31 from the first detector 31 to the third detector 31, and displays them on the received wave display unit 36. The above is the first ultrasonic transmission / reception process.

Next, the three pulse generators 29 from No. 2 to No. 4 are selected, and the second unit probe 32 to the fourth unit probe 32 of the linear array ultrasonic probe 22 are selected. Up to three unit probes 33 output pulsed ultrasonic waves at the same timing. Then, the received wave combiner 35 combines the echoes output from the three detectors 31 from the second detector 31 to the fourth detector 31, and displays the combined echo on the received wave display unit 36. The above is the second ultrasonic transmission / reception processing.

As described above, while using three channels at the same time, the channels are selected by shifting one channel at a time. This results in a total of 30 channels using 32 channels.
The output for the scanning line is displayed on the reception wave display unit 36.

Here, the reason for simultaneous excitation and simultaneous reception of the three unit probes 32 will be described. That is, since the ultrasonic beam transmitted by one unit probe 32 is thin, the defect detection sensitivity at the position between the ultrasonic beams is reduced, and the defect may be missed. Further, when several or more unit probes 32 are simultaneously excited, the vibration area for forming the ultrasonic beam becomes large, so that the accuracy of detecting the defect occurrence position is reduced and the ultrasonic beam suitable for the flaw detection is formed. Can not.

If the distance between the unit probes is shortened, an appropriate ultrasonic beam can be formed even when several or more unit probes 32 are simultaneously excited. Is equal to each other, the entire width of the linear array ultrasonic probe 22 is reduced, so that a large area cannot be detected at one time. Therefore, the number of unit probes 32 that form a single ultrasonic beam by simultaneous excitation and simultaneous reception is 2 to 2.
4 is optimal.

FIG. 3 (a) shows a steel pipe 37 having an outer diameter of 219.1 mm and a wall thickness of 8.2 mm which is parallel to the pipe axis and whose ultrasonic refraction angle is 45 ° as shown in FIG. 3 (b). FIG. 11 is a perspective view showing a case where the linear array ultrasonic probe 22 is attached to the outer peripheral surface of the steel pipe 37 via an acoustic wedge 38 formed of a polymer material such as acrylic, and the steel pipe 37 is subjected to flaw detection. The angle θ of the acoustic wedge 38 can be obtained by the following equation from Snell's law. θ = sin ^-1 (sin 45 ° / 3230 × 2730) (however, 3230 is a transverse sound velocity in a steel pipe, and 2730 is a longitudinal sound velocity in an acrylic resin. Unit: m / s)

The scan line switching time is set to 250 μsec. Therefore, the time required for the measurement processing for all 30 scan lines is 7.5 msec. Then, a through hole having an outer diameter of 3.2 mm was intentionally formed in the steel pipe 37,
FIG. 4 shows the result of flaw detection of this through hole using the linear array ultrasonic probe 22 and the electronic scanning ultrasonic inspection apparatus 28 of the embodiment.

FIG. 4 is a diagram in which the linear array probe 22 is moved in the tube axis direction and the detection sensitivity of each scanning line is measured. The overall detection sensitivity of the linear array ultrasonic probe 22 is the envelope characteristic of each of the unit probes 32 from No. 1 to No. 32 constituting the linear array ultrasonic probe 22. The difference between the maximum value and the minimum value in this envelope characteristic is 3 dB at the maximum. Since the difference of 3 dB is almost negligible when compared with the entire detection sensitivity, the range of 128 mm in the tube axis direction of the steel tube 37 can be reduced by 7.5 msec by using the linear array ultrasonic probe 22 of the embodiment. It can detect flaws at high speed. FIG. 5 is a perspective view showing a linear array ultrasonic probe to which the driving method of the present invention can be applied.

The linear array ultrasonic probe 4 of this embodiment
0 is composed of a total of 32 unit probes 41 linearly arranged in two rows. Each unit probe 41 is 1
It has a size of 0 mm x 10 mm, and 16
Since the unit probes 41 are arranged, the overall width of the linear array ultrasonic probe 40 is 160 mm. Then, as shown in the figure, each unit probe 41 in the second column from the 17th to the 32nd is compared with each unit probe 41 in the first column from the 1st to the 16th in the unit. They are arranged with a shift of 5 mm, which is half the distance between the probes.

Then, one P (VDD) having a shape equal to the entire shape of the linear array ultrasonic probe 40 is provided.
One common electrode plate 43 having the same shape is attached to the lower surface of the vibrator plate 42 made of a piezoelectric polymer material of F-TrFE). Further, a matching layer 44 having the same shape is attached to the lower surface of the common electrode plate 43. On the other hand, 32 electrode plates 45 corresponding to each unit probe 41 are mounted on the upper surface of the diaphragm 42. Then, a back layer 46 made of bakelite is attached to the upper surface of each electrode plate 45.

In the manufacturing process, first, each electrode plate 45 and each back layer 46 are formed on one plate. Next, a notch 47 is formed in the electrode plate 45 by etching.
After the electrode plate 45 is divided into 32 pieces, the lower surface of the electrode plate 45 and the upper surface of the vibrator plate 42 are bonded to form each unit probe 41.

Such a linear array ultrasonic probe 40
In the case where flaw detection is performed on the subject using the method, the ultrasonic beam is formed by one unit probe 41. That is, the ultrasonic beam is equivalent to the ultrasonic beam transmitted from the single type ultrasonic probe of 10 mm × 10 mm. Electronic scanning is
This is performed while electrically switching the probes to be transmitted and received one by one. First, flaw detection is performed by transmitting and receiving ultrasonic waves using the first unit probe 41 shown in FIG.

Next, No. 2, No. 3,..., No. 16, No. 17,
.., No. 31 and No. 32 and the unit probes 41 for transmitting and receiving ultrasonic waves are sequentially switched to perform flaw detection. Therefore,
The total number of ultrasonic beams is 32. Since the scan line switching time is set to 250 μs, the time required for the measurement process using all 32 unit probes 41 is about 8 ms.

FIG. 6 shows the linear array ultrasonic probe 40 when the linear array ultrasonic probe 40 shown in FIG. 5 is used to vertically detect a steel plate 48 as a subject having a thickness of 25 mm. FIG. 4 is a diagram illustrating a relationship between an arrangement direction (electronic scanning direction) and a mechanical scanning direction.

In general, in such an arrangement, if flaw detection is performed only with each unit probe 41 in the first row, for example, a portion of the adjacent unit probe 41 located between the ultrasonic beams may be formed. In some cases, the flaw detection sensitivity is reduced and no defect can be found. Therefore, as in the linear array ultrasonic probe of the embodiment, the unit probes 41 are arranged in two rows with their positions shifted by half the width of the unit probe, thereby achieving 1
Defects that were missed in the measurement of the second row can be reliably detected in the measurement of the second row.

As described above, in the linear array ultrasonic probe 40 shown in FIG. 5, even if the ultrasonic beam is formed by one unit probe 41, the defect can be reliably detected without overlooking the defect. . Therefore, a wide range can be detected with a small number of channels.

As described above, the linear array ultrasonic probe 2
In the units 2 and 40, one vibrator plate 25 and 42 formed of a piezoelectric polymer material having the same shape as the matching layers 27 and 44 is used as each vibrator of each unit probe 32 and 41. ing. As described above, since the piezoelectric polymer material has a smaller elastic coefficient than conventional piezoelectric ceramics, unnecessary vibration such as lateral vibration and sliding vibration hardly occurs. Therefore, since a large number of cuts as shown in FIG. 8B are not required, each of the unit probes 32 and 41 can be set to an arbitrary shape. Therefore, the linear array ultrasonic probes 22 and 40 having a wide inspection area can be easily realized. In particular, the somewhat complicated 2 shown in FIG.
Even the linear array ultrasonic probe 40 having a row configuration can be easily manufactured. Further, since the vibrator plates 25 and 42, the common electrode plates 26 and 43, and the matching layers 27 and 44 are each composed of one plate or layer, the manufacturing process is simplified, and is shown in FIGS. The manufacturing cost can be significantly reduced as compared with the conventional linear array ultrasonic probes 1, 12, and 19.

Further, since the vibrator plates 25 and 42, the common electrode plates 26 and 43, and the matching layers 27 and 44 are each composed of one plate or layer, the manufacturing process is simplified,
As compared with the conventional linear array ultrasonic probes 1, 12, and 19 shown in FIGS. 7 and 8, the manufacturing cost can be greatly reduced.

The acoustic impedance of the piezoelectric polymer material is interposed between the electrode plates 24, 45 and the back layers 23, 46 and between the common electrode plates 26, 43 and the matching layers 27, 44. Compared to the acoustic impedance of epoxy adhesive, it is not so far away. Therefore, even if the thickness of the adhesive layer of the epoxy adhesive slightly varies between the unit probes 32 and 41, the effect on the unit probes 32 and 41 is substantially the same. That is, each unit probe 32, 41 by the bonding process in manufacturing the linear array ultrasonic probes 22, 40.
Variations in work accuracy between each other can be absorbed. Therefore, the efficiency of the manufacturing operation can be improved.

The present invention is not limited to the embodiment described above. In the embodiment, the piezoelectric polymer material of P (VDF-TrFE) is used as the vibrator of the unit probe 32. However, another type of piezoelectric polymer material may be used.

In the embodiment, each unit probe 3
As a method of dividing into two, the electrode plate 24 to be adhered on the back layer 23 is divided into 32 pieces. For example, as shown in FIG. 2
The electrode plate, the vibrator plate made of a piezoelectric polymer material, the first electrode, and the back layer are laminated in this order, and are manufactured independently of each other. Good.
Further, the number of arrangements of each unit probe 41 in the linear array ultrasonic probe 40 of FIG. 5 is not limited to two, but may be three or more.

[0060]

As described above, according to the driving method of the linear array ultrasonic probe of the present invention, the transducers constituting each unit probe are made of the piezoelectric polymer material. Since this piezoelectric polymer material hardly generates lateral vibration or sliding vibration, the length of each unit probe can be set to be long, and the inspection area of the entire linear array ultrasonic probe can be set widely. . As a result, by combining with an electronic scanning ultrasonic inspection device, it becomes possible to inspect a wide range of the subject at high speed with a small number of channels,
Test work efficiency can be greatly improved. Further, a plurality of unit probes adjacent in the arrangement direction are simultaneously excited and simultaneously received. Then, a plurality of unit probes are simultaneously excited so as to move the combination of the plurality of unit probes to be simultaneously excited and simultaneously received in the arrangement direction by one unit probe. Therefore, a decrease in defect detection sensitivity at a position between the ultrasonic beams is prevented, and the overall detection accuracy is improved.

[0061]

[0062]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a linear array ultrasonic probe used in a driving method according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a schematic configuration of an electronic scanning ultrasonic inspection apparatus using the ultrasonic probe according to the embodiment;

FIG. 3 is a diagram showing an attached state of the ultrasonic probe when flaw detection is performed on a steel pipe using the ultrasonic probe of the embodiment.

FIG. 4 is a sensitivity characteristic diagram when flaw detection is performed on the steel pipe,

FIG. 5 is a schematic configuration diagram of a linear array ultrasonic probe to which the driving method of the present invention can be applied;

FIG. 6 is a diagram showing an attached state of the ultrasonic probe when detecting a flaw on a steel plate using the ultrasonic probe of the embodiment;

FIG. 7 is a schematic configuration diagram of a conventional linear array ultrasonic probe,

FIG. 8 is a schematic configuration diagram of another conventional linear array ultrasonic probe.

[Explanation of symbols]

3: subject, 22, 40: linear array ultrasonic probe,
23, 46 ... back layer, 24, 45 ... electrode plate, 25, 42
... vibrator plate, 26, 43 ... common electrode, 27, 44 ... matching layer, 28 ... electronic scanning ultrasonic inspection device, 29 ... pulse generator, 30 ... amplifier, 31 ... detector, 32, 41 ... unit search Contact element, 33: scanning channel control section, 37: steel pipe, 3
8: acoustic wedge, 48: steel plate.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-103399 (JP, A) JP-A-2-208557 (JP, A) JP-A-3-170860 (JP, A) 30230 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04R 17/00 332 G01B 17/02 G01N 29/24 502

Claims (1)

(57) [Claims] 1. A vibrator plate made of a piezoelectric polymer material, a plurality of electrode plates linearly arranged on the upper surface of the vibrator plate, and an upper surface of each of the electrode plates in common. By providing a back layer to cover, one common electrode plate attached to the lower surface of the vibrator plate, and a matching layer attached to the lower surface of the common electrode plate, a plurality of electrodes corresponding to the respective electrode plates are provided. A method for driving a linear array ultrasonic probe in which unit probes are linearly arranged, wherein the plurality of linearly arranged unit probes are adjacent to each other in the arrangement direction. A plurality of unit probes to be simultaneously excited and received simultaneously, and a combination of the plurality of unit probes to be simultaneously excited and received is moved in the arrangement direction by one unit probe. How to drive the acoustic probe.