JPS6367564A - Ultrasonic flaw detecting device - Google Patents

Abstract

PURPOSE:To perform ultrasonic flaw detection which uses a high frequency ultrasonic probe by scanning a sent ultrasonic beam electronically under phase control and using the output of one or several vibrations in the vibrator group of an array probe as a received signal. CONSTITUTION:The array probe 12 which has an acryl shoe 11 fitted on its wave transmission and reception surface is set in contact with a sample M through the acrylic shoe 11 and driven with high-voltage pulses from a multichannel pulser 13 which generates the high-voltage pulses according to a trigger timing signal from a signal controller 24, thereby sending the ultrasonic wave beam in a desired direction. This sent ultrasonic wave beam is scanned electronically in the sample M under the phase control and one vibrator almost in the center of the vibrator group which generates the sent beam TW of the array probe 12 is utilized to supply the output of the radio wave beam RW to a receiver 14.

Description

[Detailed Description of the Invention] (Objective of CB Akira) (Industrial Application Field) The present invention relates to an electronic scanning type ultrasonic flaw detection device that inspects defects in metal and non-metal materials using an ultrasonic beam. .

(Conventional technology) What about electronic scanning ultrasonic flaw detection equipment? ! Using an array-shaped ultrasonic beam in which micro oscillators of several mils are arranged in parallel, multiple adjacent oscillators are excited at different times, up to a maximum of 5 M.
The system generates approximately 82 ultrasonic waves, and creates an ultrasonic beam by the interference of these generated ultrasonic waves with a phase difference.The transmission timing of the ultrasonic beams transmitted from multiple micro oscillators The phase of ilJ lI
I strengthen the ultrasonic directivity in the desired direction,
Moreover, the ultrasonic waves can be focused on a desired point. In addition, the anti-tJJ waves of the transmitted ultrasonic waves are also received by each micro-oscillator and delayed, thereby performing phase control in the same way, adding and combining them, and adjusting the return port in the beam direction at the time of transmission. Used as an echo reception signal.

Such ultrasonic detectors require advanced technology, especially for phase control of the delivery arm, such as delaying the received ultrasonic signal using a delay line or digitizing it for processing. This results in an increase in the size of the device and limits the dynamic range of the amplification of the received signal and the flaw detection range.

FIG. 10(a) is a block diagram schematically showing one configuration of such a conventional electronic scanning type ultrasonic flaw detection device. As shown, the signal controller 10 outputs a signal at a predetermined timing, and this signal is applied to the multichannel pulser 3.

Then, the multi-channel balsa 3 applies a high-pressure pulse for ultrasonic E motion to each vibrating element of the array probe 2, respectively. This ultrasonic drive high-voltage pulse is sent to the corresponding vibrating element in a form in which a delay port is provided for each required imaging element position according to the beam direction. This results in
Each vibrating element is sensed in motion at a timing corresponding to the delay, and is sent to the subject M as a directional ultrasonic beam.

On the other hand, the reflected wave from the subject M is received by each vibrating element,
Each vibrating element generates an electrical signal corresponding to the intensity of the received ultrasound. Each of these signals is sent to a multi-channel receiver 4, where they are each subjected to signal amplification and detection processing, and then sent to a high-speed AD converter group 5.

Here, they are each converted into digital data through AD conversion, and then added and synthesized with a delay corresponding to the time of transmission in a digital adder 6. After that, a signal processor 6 converts the signals into digital data for ultrasonic scanning. The data is processed into direction-corresponding image data, converted into a video signal, and displayed as a video on the CR7 display 8.

The scanning direction of the ultrasonic beam is set by the computer 9.
The delay time is sequentially controlled to perform sector scanning based on II, and thus the ultrasonic beam BM from the array probe 2 is sector scanned.

As described above, the receiving system includes ma ultrasonic receivers 4 corresponding to each transducer of the array probe 2, and an AD conversion pre-conversion group 5 that digitizes the signals from these ultrasonic receivers 4. It consists of an adder 6 that adds the output data of each AD converter group 5 with a delay.

Among these, each AD converter group 5 requires a high-speed digital converter capable of digitizing at least one wavelength at 5 to 10 points in order to digitize the received high-frequency ultrasonic signal.

FIG. 10(b) shows an acrylic shoe 1, which is a sound wave propagation medium, on the flaw detection surface of the array probe 2 using such a device.
It also shows the situation when the ultrasonic beam is scanned in a fan-shaped manner by adding a transverse wave to the blade implantation part 7 of the turbine wheel part of the object M using the refraction of the ultrasonic wave. Figure (C) shows the 8-scope images at that time.

Generally, when ultrasonic waves are incident on a steel material from an acrylic shoe, the beam is refracted, and as a result, the transmitting and receiving points of the ultrasonic beam are apparently different from one point. It is difficult to determine the defect location.

Of course, as the ultrasonic transducer rotates within the acrylic shoe, the variable angle flaw detection method that displays the B-scope cross section takes into account changes in the transmitting and receiving points of the ultrasonic beam and the beam propagation time within the acrylic shoe. Although there are some examples, in this method, the flaw detection area is determined in advance, the data within the area is digitized once, the defect position is calculated, and then displayed on the CRT screen. It is difficult to intuitively judge the refraction angle, beam path length, etc. Therefore,
It is difficult to judge the results accurately.

In particular, the ultrasound beam is reflected from each geometrically shaped part of the object where similar geometrically shaped parts continue over and over again,
There is also a risk that an image that appears when a mode conversion or the like occurs may be mistakenly determined to be a defective image, and thus is not necessarily very practical.

In addition, in order to display defect images in real time, the display becomes slow due to digitization processing, etc., and when high-speed image display is required, such as with electronic scanning methods, the equipment becomes larger. It becomes complicated and portability suffers.

Furthermore, as shown in Fig. 10(b), when displaying the B scope using sector scanning, generally speaking, as the refraction angle of the ultrasonic beam increases, the flaw detection distance also increases, and the flaw detection equipment also , it is necessary to display a display according to the cross section of the specimen, so flaw detection vi@
It becomes necessary to design the system in a closed manner, resulting in a lack of versatility.

(Problems to be Solved by the Invention) As described above, the electronic scanning ultrasonic flaw detection device has a plurality of ultrasonic receivers 4 corresponding to each transducer of the array probe 2 as its receiving system, AD! which digitizes the signals from these ultrasonic receivers 4! It consists of a converter group 5 and an adder 6 that adds the output data of each of these AD converter groups 5 with a delay.

Among these, each AD converter group 5 requires a high-speed digital converter capable of digitizing at least one wavelength at 5 to 10 points in order to digitize the received high-frequency ultrasonic signal. Furthermore, it is necessary to provide a corresponding one for each vibrator.

Therefore, the number of them is enormous, and problems of cost and occupied space remain.

In addition, it is necessary to delay and add the phase of the received ultrasonic signal, but when the ultrasonic wave has a high frequency, there is a delay of 11! for phase matching of the received waveform! The fl system [1 degree is insufficient, the waveform is also distorted by the delay, and sufficient phase addition cannot be performed. Therefore, the image becomes unclear and the flaw detection accuracy is also poor.

In addition, as a feature of electronic scanning, B scope images can be converted to C in real time.
It can be displayed on RT, but if the shape of the object changes, the refraction angle increases, the detection Il area increases, or reflection, scattering, or mode conversion occurs within the object, , the display is uniform, making it difficult to interpret the flaw detection results. Furthermore, when recording the flaw detection results in an external storage device, it is necessary to fix the recording area in advance or to digitize and record the flaw detection screen as it is.
If the conditions for detecting defective echoes are not sufficiently understood in advance, important defective echoes may not be recorded or even unnecessary data may be recorded, requiring a huge amount of memory space. .

Therefore, it is an object of the present invention to make it possible to perform electronic scanning ultrasound using a probe that generates high-frequency ultrasound, and to make it possible to easily judge flaw detection results and to reduce the size of the ultrasound. The purpose of the present invention is to provide a sonic flaw detection device.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows. That is, a driving unit that controls the array probe and each sensor constituting the array probe to electronically scan the transmitted ultrasonic beam by phase control.
J10 means, a receiver that obtains the transfer signal output of one or a few perturbators of the transducer group of the array probe and detects and amplifies it, and a receiver that receives the output signal of this receiver and displays the display screen of the display device. It comprises a display control means for sequentially and parallelly displaying the A scope at positions corresponding to the ultrasonic scanning lines.

(Function) In such a configuration, the drive control means drives and controls each transducer constituting the array probe to electronically scan the transmitted ultrasonic beam by phase control. Then, the transmitted ultrasonic beam is electronically scanned. on the other hand,
For wave reception, a receiver detects and amplifies the received signal output of one or a small number of transducers of a group of transducers constituting the array probe. The output signal of this receiver is given to a display control means, and upon receiving the signal from this receiver, the display control means controls the signal to be displayed on the A scope in order at the position corresponding to the ultrasonic scanning line on the display screen of the display device. Generates a display signal. As a result, the A scope images are displayed in parallel in sequence in correspondence with the ultrasound scanning at positions corresponding to the ultrasound scanning lines on the display screen of the display device.

In this way, in this device, the transmitted ultrasonic beam is electronically scanned by phase 1 control, the received signal uses the output of one or a small number of transducers in the transducer group of the array probe, and the transmitted wave is Waves are received directionally, and waves are received non-directionally, and the non-directionally received waveform is displayed on the A scope in a field corresponding to the ultrasonic scanning line on the display screen of the display unit.

Therefore, according to this device, since the transfer signal is processed without phase control, it becomes possible to easily perform high-frequency electronic scanning ultrasonic search, and the configuration of the device is 1/2! ! The data can be accumulated, and an AD converter is not required, making it possible to reduce the size. In addition, since analog signals can be handled as they are, signal processing speed is high, and a sufficient flaw detection distance can be obtained, improving detection efficiency. In addition, in the present invention, even in sector scanning, the A scopes can be arranged and displayed in the scanning order, so the same observation effect as the B scope can be obtained. The complexity of determination such as B scope images caused by , refraction, and scattering is eliminated.

Therefore, according to the present invention, it is possible to perform electronic scanning ultrasound using a probe that generates high-frequency ultrasound, and it is also possible to use an ultrasonic probe that can easily judge flaw detection results and can be miniaturized. (I equipment can be provided.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the apparatus according to the present invention.

In the figure, 11 is an acrylic shoe, and 12 is an array probe. It is driven by high-pressure pulses from the channel balsa 13 and transmits an ultrasonic beam in a desired direction. 15 is a CR1 display that displays an ultrasound image, 14 is a receiver for one channel, and this receiver 14 is connected to the array probe 12.
For example, the ultrasonic beam received by the central transducer is amplified and detected. 16 is a CRT signal generator
A display signal of an ultrasonic image to be displayed on the display 15 is generated. Specifically, the receiver 14 receives the amplified and detected delivery ultrasonic beam signal, generates a Y-axis 11 pull signal, and also generates a biaxial signal.
The RT signal generator 16 receives the transmit beam trigger synchronization signal from the signal controller 24 to generate the computer 25.
At the same time, the beam path length C1, beam incident point position ai, and refraction angle θi within the acrylic shoe 11 regarding the scanning position are known, and the beam path length C1, beam incidence point position ai, and refraction angle θi are known. The X-axis as a CRT signal, that is, the time sweep is performed by rotating the performance port.

22 is a setting data memory (RO~1); 23 is a flaw detection data recorder such as a magnetic disk for recording collected data;
4 is a signal controller, and 25 is a computer that controls the entire system. The setting data memory 22 stores setting data for the timing at which high-voltage pulses are sent to each ultrasonic transducer to perform each electronic scan. 18, and the computer 25 transmits high-pressure pulses to each ultrasonic + fi element to perform electronic scanning according to the radiation direction of the ultrasonic scanning line that changes as the sector scan progresses. Setting data for trigger generation timing is read out from this memory 22 and used for control. Further, in the memory in the computer 25, the beam path distance wit in the acrylic shoe 11 shown in FIG. . This writing may be inputted for each scanning line from the keyboard of the computer 25, or may be performed by oneself based on the theoretical total J.

Here, the signal controller 24 outputs n scans $31 from the computer 25 based on the data in the setting data memory 22.
7-4. It has four surfaces that send trigger signals for transmitting beams to each balsa while sequentially repeating and reading trigger generation timing commands from 17-n to 17-n.

Reference numeral 20 denotes a probe position detector for measuring the position of the array probe on the subject M, which uses a potentiometer, an encoder, a magnetic scale, etc. Reference numeral 21 denotes a gate signal generator that outputs a signal in a set gate range. By setting the gate range, the CRT signal generator 16 receives the gate range setting signal from the gate signal generator 21 and outputs a signal in the CRT display 15. Modulate the gate range upwards.

The gate signal generator 21 carries two scanning lines and can freely set two arbitrary points on each of the scanning lines.
Once such settings are made, a gate signal is generated based on these settings.

Next, the operation of this device having the above configuration will be explained.

The array probe 12 with the acrylic shoe 11 attached to the wave transmitting/receiving surface is set in contact with the subject M via the acrylic shoe 11. In this state, the array probe 12
is driven by high-pressure pulses from the multi-channel balsa 13 that generates high-pressure pulses in accordance with a trigger timing signal from the signal controller 24, and transmits an ultrasonic beam in a desired direction.

As shown in FIG. 2, the transmitted ultrasonic beam is electronically scanned within the object M by phase control, but the received beam RW is sent to a transducer that forms the transmitted beam TW of the array probe 12. One (or about two) vibrators located approximately in the center of the group are used, and their output is given to the receiver 14.

The received signal of the ultrasonic beam thus received at the center of the array probe 12 is amplified and detected by the receiver 14, and then input to the CRT signal generator 1G and used as a Y-axis signal.

On the other hand, when the CRT signal generator 16 receives the trigger synchronization signal IZ of the transmitted beam from the signal controller 24, the computer 25 simultaneously calculates the beam path length λi and beam incident point position a1 within the acrylic shoe 11 regarding the scanning position.
and the refraction angle θi, perform the following calculation on the X axis as a CRT signal, that is, the beam path length signal T, and
An X-axis signal, that is, a time sweep signal is generated as a signal.

T i -T -(ffil/CI) +LJ
...(1) Tl--Ti-cosθ1+u--...
(2>Ti″-Ti-sinθ1-(βi/CI)+u″...(3) Here, the beam path length signal T in the first equation is used for display based on the beam path standard, and is shown in Fig. 4. As shown, this is a sweep signal generated based on a signal synchronized with a trigger signal sent from the signal controller 24 to the balsa 13.

Further, C1 is the sound velocity of the ultrasonic wave inside the acrylic shoe 11, U
is a signal that controls an arbitrarily fixed insertion start point on the CR7 display 15, and the CRT signal generator 16 generates y4.
It will be arranged.

Also, the second type is used for display based on the depth direction reference, and x? on the CRT display 15. This is an arithmetic expression when performing an ill sweep at a depth distance from the surface of the subject M, and is adjusted by the CRT signal generator 16 similarly to the U' beam.

The third formula is used for display based on the distance direction M quasi, and is an arithmetic expression for displaying the distance on the subject from the probe 12 on the X axis, where C2 is the sound velocity in the subject, u'' is U
, U-, this is a signal that controls the CRT (7) Xllll pull start point.

As a result, as shown in the third factor, the appearance of the ultrasonic beam for each scanning line changes to the upper incident point position a1. ~an and beam path length λ1. ~2n will change, but these can be corrected and displayed.

As shown in Figure 5, the above three display methods, that is, the 1,1 gravity type on the , and which method is selected is determined by the CRT signal generator 16.
can be selected arbitrarily.

A two-axis signal, that is, a brightness modulation signal, is also output from the CRT signal generator 1G for each scanning line, and a Y-axis signal is applied to each scanning line ia-i, ~18-n@, so that the signal on the CR7 display 15 is The probe I waveform (A scope image) at the scanning line is displayed at the display position corresponding to the ultrasound scanning line.

As shown in Figure 5, this display is arranged in the order of sector scanning and displayed in parallel like 18-1 to 18-n, and since it is an A-scope display, the situation and location of the defect are clear. I understand. In this way, the appearance of the ultrasonic beam for each scanning line is determined by the upper incident point position ai, ~an and the beam path length λ1. ~2n changes, but this can be corrected and displayed, making it easier to judge the search 1m result.

The CRT signal generator 16 outputs the A of some or all of the scanning lines arbitrarily selected to the CR7 display 15 by giving a switching command via the combinations 1 to 25, for example.
In addition to displaying the scope image 26 in an enlarged manner, it is possible to set and display on the CR7 display 15 a comparison reference level 27 for determining whether or not to perform brightness modulation.

Next, by setting the gate range in the gate signal generator 21, the CRT signal generator 16 receives the gate range setting signal from the gate signal generator 21 and modulates the brightness of the gate range on the CR7 display 15. . The gate signal generator 21 can select two scanning lines 181°18j and freely set any two points p1, p2 on the scanning machine. It generates a gate signal. Among the brightness display points 19 displayed on the CR7 display 15, the flaw detection data of the brightness display points 19 within the area surrounded by these four points set in the gate signal generator 21 is sent to the computer 25.

That is, as shown in FIG. 6, the maximum peak of the 28 deep damage waveforms within the gate exceeds the comparison reference level 27 lit! P1
．． P2. P3 and the beam path length t1 of their peak values.
t2. t3 is detected in the CRT signal generator 16 and sent to the computer 25 along with the scan line number.

The computer 25 is provided with setting data from a setting data memory 22 that stores setting data for trigger generation timing for transmitting high-voltage pulses to each ultrasonic transducer to perform each electronic scan for 1M, together with the numbers of the scanning lines 18. Also, in the memory in the computer 25, a third
Beam path distance i in the acrylic shoe 11 shown in the figure
, the beam incidence point ai, and the refraction angle θ1 to the subject M are written.

In addition, the computer 25 stores flaw detection data on a magnetic disk, etc., and the beam path distance λ in the acrylic shoe 11.
i, beam incidence point a1. Refraction angle Qi and array probe 1
The position information corresponding to 2 is also written and saved. Of course, the array probe position is determined by the probe position detector 20.
This is position information measured by .

Next, FIG. 7 shows another application example of the present invention in which a probe and a shoe are applied to a curved surface. In this case, the curved surface shape A1 of the object. If you know A2゜..., Ai... in advance, you can find the positions 1ffai and bi from the end surface of the array probe for each scanning line, and easily create a probe image as shown in Figure 5. Can be displayed.

FIG. 8 shows an example in which an array probe is used for electronic scanning during wave transmission, and another probe is used for wave reception.

In this case, since a sufficiently large sensor can be used as the wave receiving probe, depth sensitivity is improved.

This also means that if we consider the case where longitudinal waves are transmitted by an array probe and received by a vertical longitudinal wave probe 29, the difference between the transmission and delivery of ultrasonic waves is as shown in Figure 9. , both have high sound pressure transmission efficiency, so higher flaw detection accuracy can be obtained than before.

In this case, the distance between the vertical probe and the array probe is
1IlS, the ultrasonic beam path T is equal to the elliptical curved surface 30, with the focus being the array probe incident point F1 and the vertical probe receiving point F2, so the refraction angle of the transmitted beam is By knowing θi, the position of the defect 31 can be easily known. Of course, it goes without saying that the defect position can be similarly measured when transverse waves are incident and longitudinal waves are received.

In this way, in this device, the transmitted ultrasonic beam is electronically scanned by phase control, the received signal uses the output of the central transducer of the array probe's transducer group, and the transmitted wave has directivity. In addition, the wave reception is performed omnidirectionally, and the received signal is displayed on the A-scope at a position corresponding to the ultrasonic scanning line on the display screen of the display device.

Therefore, according to this V device, since the received signal is processed without phase control, high frequency electronic scanning ultrasonic detectors can be easily put into practice, and the configuration of the device is simplified. ,
Furthermore, since an AD converter is not required and the device can be made compact, it is easy to use the device in a narrow space. In addition, since the signal can be handled as an analog signal, the signal processing speed is high, and therefore a sufficient flaw detection distance can be taken, which improves flaw detection efficiency.The A-scope display improves the noise ratio and dynamic range. etc. will be significantly improved. Also,
In the present invention, even in sector scanning, the A scopes can be arranged and displayed in the scanning order, so the configuration of the display system is simple and the A\X effect can be obtained in the same way as the B scope. This eliminates the complexity of determining B-scope images due to differences in display scanning density between long-distance path and short-distance path, and ultrasound beam reflection, refraction, and scattering. Furthermore, since the A-scope display system can be instantly switched and displayed between the beam path reference, the depth direction reference, and the distance direction reference, it becomes easier to directly evaluate the flaw detection results.

Furthermore, since the range of data to be recorded can be arbitrarily set while observing the image of the flaw detection results, the flaw detection data can be efficiently recorded in the memory.

Since these data in the memory are recorded together with the probe position and flaw detection conditions, 8 scope images and C scope images can be created by offline processing.

Furthermore, these data may be used as data for aperture synthesis, thereby achieving high resolution l! A single B-scope or C-scope image can now be created.

In the embodiment of the present invention, a configuration example using a single receiver 14 has been shown, but the number of receivers may be increased by about 1 or 2, and outputs from a small number of plural oscillators may be used. Further, the amplification of the received signal of the receiver 14 may be changed for each ultrasonic beam scanning line. In particular, if the received signal amplification degree is changed along the beam propagation path, amplification along the so-called beam path distance attenuation correction curve becomes possible, and the judgment of the flaw detection results becomes easier. Further, the transducer used for delivery is not limited to the one in the center of the transducer group of the array probe, but may be in the center of those used for transmission, or in any other arbitrary position. Further, similar effects can be obtained even if the comparison reference level curve shown in this embodiment is applied to each scanning line, and both are included in the gist of the present invention. Furthermore, although the case of an array probe provided with an acrylic shoe has been described as an embodiment of the present invention, the present application also includes a case where flaw detection is performed by local immersion or water immersion in a liquid such as an ice bag. Furthermore, measurements can also be made by directly bringing the array probe into contact with the subject without attaching a shoe or the like. Furthermore, although this example uses a probe with transducers arranged in a straight line, a circular arrangement,
It can also be applied to curved arrays. Further, in the embodiment, the data recorded in the data recorder is set to the maximum peak value, but the signal waveform within the gate may also be recorded.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to perform electronic scanning layer sound waves using a probe that generates high-frequency ultrasonic waves, and it is also possible to easily judge flaw detection results and to reduce the size. It is possible to provide an ultrasonic detection device.

[Brief explanation of the drawing]

FIG. 1(a) is a block diagram showing one embodiment of the present invention, FIGS. 1(b) and 1(c) are diagrams for explaining the data collection w4 range setting and brightness modulation setting in this device, and FIG. The figure is a principle diagram for explaining the present invention in detail, Figure 3 is a schematic diagram of electronic scanning for explaining the present invention in detail, Figures 4 and 5
Figures (a), (b), and (C) are diagrams showing examples of A scope display as an embodiment of the present invention, Figure 6 is a diagram for explaining an example of the contents of the recorded portion of flaw detection data in the present invention, and Figure 7 The figures are diagrams for explaining an example of applying the present invention to a curved surface, Figures 8(a) and 8(b) are diagrams for explaining the two-probe method as an example of applying the present invention to a pond, 9(a) and (b) are diagrams for explaining the present invention in detail, and FIGS. 10(a), (b), and (c) are diagrams for explaining the conventional example. 11... Acrylic shoe, 12... Array probe,
13... Multi-channel balsa, 14... Receiver, 15... CRT display, 22... Setting data memory (ROM), 23... Flaw detection data recorder, 24...
...Signal controller J, 25...Computer. Applicant's representative Patent attorney Takehiko Suzue (b) (c) Figure 1 Figure 2 Figure 10 Figure 4 Figure 5 Figure 7 Figure 8 (a) (b) Figure 9

Claims (2)

[Claims] (1) An array probe, a drive control means for driving and controlling each transducer constituting the array probe so that the transmitted ultrasonic beam is electronically scanned by phase control, and vibration of the array probe. a receiver that obtains the received signal output of one or a small number of oscillators in the child group, and detects and amplifies the received signal output;
An ultrasonic flaw detection apparatus comprising display control means for receiving the output signal of the receiver and displaying the A scope in parallel in sequence at positions corresponding to the ultrasonic scanning lines on a display screen of a display device. (2) The display control means has a function of switching the A scope display to a display based on any one of a beam path reference, a depth direction reference, and a distance direction reference. The ultrasonic flaw detection device according to scope 1.