JPH0933494A - Ultrasonic flaw detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultrasonic flaw detector in which the secular change can be evaluated surely while shortening the processing time. SOLUTION: An A/D converter 3 converts a video signal 20 having A scope waveform outputted from an ultrasonic flaw detector 2 into a digital value. A converted digital data 27 is transferred to a waveform acquisition circuit 4 and a peak detection circuit 5. The waveform acquisition circuit 4 collects the waveform data in a waveform memory depending on the resolution set by a setter 11 and the number of data and then sequentially records the waveform data on a recorder 13. On the other hand, a peak detection circuit 5 and a route counter 6 detect the peak value of echo and the route thereof, respectively, at a plurality of points. A threshold level set circuit 8 sets a threshold level 24, designated by a computer 10, in the peak detection circuit 5. The peak detection circuit 5 detects the peak of data exceeding the threshold level 24 within the gate range of a gate signal 25 and the waveform acquisition circuit 4 acquires a waveform in parallel therewith. A recorder 13 records the peak value and route data for one echo point separately from the waveform data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic flaw detector which carries out in parallel the processing of taking in all ultrasonic flaw detection signals as digital values and the processing of extracting peak waveform data.

[0002]

2. Description of the Related Art In a pulse reflection type ultrasonic flaw detection method, the relationship between the received signal strength (echo height) of ultrasonic waves and the propagation distance (path length) is generally obtained as information from an A-scope waveform displayed on a cathode ray tube. You can At that time, since the time base adjustment and the sensitivity adjustment are performed by the contrast test piece before the measurement, the state inside the subject is evaluated from the echo height and the path length at the time of the detected flaw, in other words, the soundness inside the subject is evaluated. be able to.

By the way, in the conventional ultrasonic flaw detectors, as disclosed in, for example, Japanese Patent Laid-Open No. 58-219451, the echo heights of a plurality of echoes detected at a certain probe position are detected. The peak value and its distance were recorded automatically. This example will be described with reference to FIGS. 4 and 5.

FIG. 4 is a block diagram showing a configuration from ultrasonic wave transmission / reception to data recording in a conventional ultrasonic flaw detector. In the figure, an ultrasonic flaw detector comprises a data recording device 1, an ultrasonic flaw detector 2, an ultrasonic probe 14 for scanning a subject 17, and a drive device 15 for the ultrasonic probe 14.
And its control device 16. The data recording device 1 includes an A / D converter 3, a peak detection circuit (analog type) 5A, a road distance counter (counter parallel type) 6
A, a position counter 7, a threshold level setting circuit (analog type) 8A and a computer 10, a setting device 11, a display device 12 and a recording device 13. The ultrasonic flaw detector 2 includes a gate signal circuit 9 for generating a gate signal.

As shown in FIG. 5, the ultrasonic flaw detector 2 outputs to the ultrasonic probe 14 a drive pulse for generating ultrasonic waves which is activated by a trigger signal at a constant period T, whereby the ultrasonic probe is activated. 14 emits ultrasonic waves to the subject 17. The ultrasonic waves reflected from the inside of the subject 17 and the inside are detected by the ultrasonic flaw detector 2
It is converted into an electric signal by and is displayed on the cathode ray tube of the ultrasonic flaw detector 2 as an A scope waveform. The A-scope waveform is output to the peak detection circuit 5A as an analog video signal. The peak detection circuit 5A detects a plurality of echoes exceeding the threshold level in the gate signal and outputs the peak value of the echoes to the computer 10. FIG. 5 shows the case of two detections of and. The path length counter 6A measures the peak path length obtained by the peak detection circuit 5A and outputs it to the computer 10. The control device 16 controls the scanning of the driving device 15 and outputs the position signal of the ultrasonic probe 14 that is interlocked with the driving device 15 to the position counter 7. The computer 10 collectively records the probe position data obtained by the position counter 7, the detected peak value of the echo, and the path length data in the recording device 13.

On the other hand, as disclosed in Japanese Patent Laid-Open No. 59-75147, it is also possible to perform A / D conversion of the entire A-scope waveform and load it in the waveform memory for processing. However, in order to accurately capture the maximum value of the A-scope waveform in A / D conversion, a sampling clock of about 10 times the flaw detection frequency is usually required. Therefore, the amount of data becomes enormous, and it may be limited to the flaw detection area, the time axis measurement range of the A scope, or the measurement only within the gate due to the capacity of the recording device.

Further, Japanese Patent Application Laid-Open No. 4-42051 discloses that
A transmitting unit that outputs a predetermined pulse to the ultrasonic probe, a receiving unit that receives a signal from the ultrasonic probe, and a signal received by the receiving unit are sequentially A / A / D converter for D conversion, waveform memory for storing data converted by the A / D converter, address counter for sequentially specifying addresses of the waveform memory, and data stored in the waveform memory are displayed. In the ultrasonic flaw detector provided with a display unit, a gate means for selecting an arbitrary time range after pulse output, and a peak value detecting means for detecting all peak values of data existing in the selected time range, , A storage means for storing the output value of the address counter corresponding to each peak value when each of the peaks is detected is disclosed.

Further, in an ultrasonic flaw detector of the type in which an evaluation level is provided, a plurality of echoes are detected, and the peak value of the echo height and the path length are taken in, echoes outside the evaluation range and below the evaluation level are not recorded. Become.

[0009]

[Problems to be Solved by the Invention] In ultrasonic flaw detection,
The intensity of the reflected echo is evaluated to measure the reflection source in the subject, and the information on the secular change of the reflection source is also important. For example, in the in-service inspection of a nuclear power plant, the soundness is evaluated by comparing with the previous in-service inspection data or the pre-service inspection data.

In the ultrasonic flaw inspection, various charts used for evaluation are calculated from the echo height peak values at a plurality of points and the path length and output. Therefore, the ultrasonic flaw detector of the type that A / D-converts and captures the A-scope waveform also needs a function of detecting peak values of echo heights at a plurality of points and the path length. Without this detection function, the echo height peak value accumulated so far cannot be compared with the road length data, making it impossible to evaluate secular change.

In the case of an ultrasonic flaw detector of the type in which the A-scope waveform is A / D converted and taken in, as in the conventional ultrasonic flaw detector, the A-scope waveform is A / D-converted before or after A / D conversion. Separately, it is possible to detect the echo height peak value and the road distance, but the detected echo height peak value and the road distance data are A / D converted after the A / D converter or peak detection circuit error. Often does not match the waveform data of. It is also conceivable to detect the echo height peak value and the path length from the data that has been subjected to the waveform acquisition processing after the A / D conversion once. In order to perform the processing for detecting the, the processing time is long, the inspection time is long, and the inspection efficiency is poor.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 4-42051, all the peak values of the data existing within the selected time range are detected, and the output value of the address counter corresponding to each peak value is detected. It is designed to be remembered. That is, only the peak value and its timing are stored, and the state below the threshold level is unknown. Therefore, as described above, when comparing the inspection data during the previous service period or the inspection data before service to evaluate the soundness, no defects were found in the previous inspection, but this time the investigation When a defect is found in, the state cannot be grasped as long as the previous state is below the threshold level. Therefore, if it is possible to grasp the state in which some kind of defect is likely to occur in the near future, it becomes possible to make a more realistic evaluation when evaluating the soundness.

The present invention has been made in view of the circumstances of the prior art as described above, and an object thereof is to provide an ultrasonic flaw detector capable of surely evaluating secular changes and having a short processing time. Especially.

[0014]

In order to achieve the above object, in the present invention, an ultrasonic beam is transmitted from an ultrasonic probe to a subject, and a reflected wave from inside the subject is received and output. In an ultrasonic flaw detector for detecting a flaw inside a subject based on the intensity of a received signal from the ultrasonic flaw detector and the propagation time, an A / D conversion means for A / D converting the detected flaw detection waveform, and an A / D converter A capturing means for capturing all the converted digital data, an extracting means for extracting a plurality of peak waveform data from the A / D converted digital data, a data captured by the capturing means, and an extracting means for extracting the peak waveform data. And a means for recording the recorded data respectively,
It is characterized in that the processing by the acquisition means and the processing by the extraction means are executed in parallel and recorded by the recording means.

In this case, the extracting means can be composed of a peak detection circuit for detecting a peak value from the A / D converted digital data and a path length counter for detecting the peak position. Further, the ultrasonic probe is provided with transducers for a plurality of refraction angles, and control means for time-divisionally performing transmission and reception for a predetermined refraction angle from the ultrasound probe is used to control one ultrasonic transducer. It is also possible to make it possible to carry out flaw detection at a plurality of angles at one location using a sound wave probe.

[0016]

[Operation] A scope waveform obtained by ultrasonic flaw detection
The digital data converted by the / D conversion means are transferred to the acquisition means, which is, for example, a waveform acquisition circuit, and the extraction means, which is, for example, a peak detection circuit, whereby both means perform independent processing in parallel. Start. First, in the capturing means, for all the A / D converted data, waveform data is recorded in a storage means such as a waveform memory according to the resolution and the number of data set by a setting device, and is sequentially recorded in a recording device as a recording means. Record. Next, in the peak detection circuit, the echo detection effective range is set by the gate signal set by the ultrasonic flaw detector, and the peak detection circuit is activated. In the peak detection circuit, A / D
The converted data, for example, by the threshold level setting circuit, is regarded as one echo from when the data exceeds the set threshold level to below the set threshold level, and the data is sequentially compared with the data sequentially captured in the echo. By retaining the higher data, the maximum data is detected as a peak. This peak detection can detect an echo generated in the gate. Regarding the path length for each peak, the number of data addresses up to the peak value becomes the path length among the number of data A / D converted from the trigger signal output from the ultrasonic flaw detector by the sampling clock. The road length counter that constitutes the means for extracting counts the number of address updates for storing the A / D converted data in the memory, and the road length counter value at the moment when the data taken in by the peak detection circuit exceeds the threshold level. By measuring, the path value of the echo is detected.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

This embodiment relates to an ultrasonic flaw detector applied to an inspection during a period of common use in a nuclear power plant, and the configuration of the ultrasonic flaw detector is shown in FIG. Further, FIG. 2 is a timing chart for detecting plural peaks, and FIG. 3 is a block diagram of a peak detecting circuit. It should be noted that the same reference numerals are given to the respective units that can be regarded as equivalent to the above-described conventional example shown in FIG.

The data recording apparatus 1 according to the embodiment includes an A / D converter 3 for A / D converting the video signal 20 output from the ultrasonic flaw detector 2, and a digital signal converted by the A / D converter 3. Waveform capture circuit 4 that captures all data 27
, The gate signal 25 and the trigger signal 23 output from the ultrasonic flaw detector 2, and the digital data 27 converted by the A / D converter 3 are input, the peak detection circuit 5 for detecting a peak, and the ultrasonic flaw detector. 2, the path signal counter 6 to which the trigger signal 23 output from 2 and the peak detection timing from the peak detection circuit 5 are input, and the threshold value that sets the threshold value and sets the threshold level 24 for peak detection in the peak detection circuit 5. It comprises a level setting circuit 8 and a position counter 7, a display 12 and a recording device 13 similar to those in FIG. Other parts, which are not particularly described, are configured similarly to the conventional example of FIG.

In the ultrasonic flaw detector 1 constructed as described above, the A / D converter 3 obtains the maximum peak value of the echo from the video signal 20 of the A-scope waveform output from the ultrasonic flaw detector 2. It is converted into a digital value by a constant high-speed sampling clock that does not occur. The converted digital data 27 is transferred to the waveform acquisition circuit 4 and the peak detection circuit 5. In the waveform capturing circuit 4, the waveform data is recorded in the waveform memory according to the resolution and the number of data set by the setting device 11, and sequentially recorded in the recording device 13. In parallel with this, the peak values of the echo heights at a plurality of points and their path lengths are detected by a peak detection circuit 5 and a path length counter (counter latch method) 6, respectively. The threshold level setting circuit 8 sets the threshold level 24 designated by the computer 10 in the peak detection circuit 5. The peak detection circuit 5 performs peak detection processing and waveform acquisition processing by the waveform acquisition circuit 4 in parallel for data that exceeds the threshold level 24 within the gate range of the input gate signal 25. Separately, the peak value and the road length data are recorded in the recording device 13 for one echo.

The above operation will be described in detail below.

In the timing chart of FIG.
Is a video waveform, and here shows the case of two echoes. 2
1 is an echo, 22 is an echo, 23 is a trigger signal, 2
4 is a threshold level, 25 is a gate signal, 2
6 is an event signal indicating the detection of an echo, 27 is waveform data after A / D conversion, 28 is an output of a path length counter, 29 is peak latch data of the first point, 30 is a path value of the first point,
Reference numeral 31 indicates peak latch data for the second point, and 32 indicates the path length for the second point.

The peak detection circuit 5 reads the waveform data 27 after A / D conversion output from the A / D converter 3 in time sequence as shown in FIG. For example, the waveform data 27a is transferred to the event generator 35 and the peak detector 36. When the event signal generator 35 detects the waveform data that exceeds the threshold level 24, it validates the event signal 26 and instructs the road distance counter 6 to perform measurement. The road distance counter 6 holds the road distance value 30 at the first point of the measurement result until the peak value is determined (the event signal 26 becomes invalid). Further, the peak detector 36 includes the waveform data 27a and the peak latch data 29 (in the figure, "2", "5", "8", "8",
"8", "8") are taken in and compared, and waveform data 2
If 7a is large, a latch signal is transmitted to the peak latch 37. This is continued until the event signal 26 becomes invalid. When the event signal 26 becomes invalid, the peak latch data 29 is latched by the peak final latch 38 and 1
The peak value 29a (“8” in the figure) of the echo at the point is held, and the peak value 29a (“50” in the figure) at the first point is output to the computer 10.

After the peak 21 at the first point is detected, the waveform data 27 after A / D conversion is continuously read in preparation for the detection of the peak 22 at the second point. When the second peak 22 is detected, the peak 31 a (“4” in the figure) and the road length value 32 (“66” in the figure) are similarly output to the computer 10. If there are more peaks, the above-described peak detection and peak value / path length value output are repeated.

The position counter 7 shown in FIG.
The probe position information is read from 6 and output to the computer 10.

The computer 10 collectively records a plurality of echo height peak values and their path lengths and probe position information in the recording device 13.

As described above, according to this embodiment, it is possible to take in waveform data from A / D converted data and record a plurality of peak values and path lengths in parallel. It became possible to record. In addition, it becomes possible to display a trajectory or a plane in which echoes are superimposed in real time using these peak values and road lengths. Furthermore, since the waveform data acquisition and peak value detection are recorded from the same data, the peak value of the reproduced waveform is recorded by the data recording device even when the waveform is reproduced by offline processing using the recorded waveform data. The echo height is the same as the peak value and does not include an error.

Although not particularly described in the present embodiment, the data recorded by the data recording device 1 is subjected to a pre-programmed process by a separately provided data processing device to perform the required analysis. After
It is output as various charts. As various charts, multiple peak values, path lengths of each peak value, and probe position signals are used to display real-time trajectory display, superimposed trajectory and plane display, or plane display. , Top view, cross section, side view and evaluation list.

[0029]

As is apparent from the above description, according to the present invention configured as described above, it is possible to capture waveform data from A / D converted data and record a plurality of peak values and path lengths. Since both of these data can be recorded in real time, it is possible to extract a plurality of echo height peak values that match the reproduced waveform data and their path lengths at high speed. Further, since it is possible to directly compare the real-time display such as the trajectory display or the plane display on which the echo is superimposed with the past flaw detection data, it is possible to evaluate the secular change of the subject.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic flaw detector according to an embodiment of the present invention.

FIG. 2 is a timing chart showing an echo height peak value and a roadway detection timing of the ultrasonic flaw detector according to the embodiment.

FIG. 3 is a block diagram showing a configuration of a peak detection circuit according to an embodiment.

FIG. 4 is a block diagram showing a schematic configuration of an ultrasonic flaw detector according to a conventional example.

FIG. 5 is a timing chart showing an echo height peak value and a road length detection timing of an ultrasonic flaw detector according to a conventional example.

[Explanation of symbols]

1 Data Recording Device 2 Ultrasonic Flaw Detector 3 A / D Converter 4 Waveform Capture Circuit 5 Peak Detection Circuit (Digital Type) 5A Peak Detection Circuit (Analog Type) 6 Road Distance Counter (Counter Latch Method) 6A Road Distance Counter (Counter Parallel) Method 7 Position counter 8 Threshold level setting circuit (digital type) 8A Threshold level setting circuit (analog type) 9 Gate signal circuit 10 Computer 11 Setting device 12 Display device 13 Recording device 14 Ultrasonic probe 15 Driving device 16 Controller 17 Subject

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakazu Kameda 3-2-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Engineering Co., Ltd.

Claims (3)

[Claims] 1. An ultrasonic beam is transmitted from an ultrasonic probe to a subject, the reflected wave from the inside of the subject is received, and the received signal strength from the ultrasonic flaw detector output and the propagation time are detected. In an ultrasonic flaw detector for detecting flaws inside a specimen, A / D conversion means for A / D converting the flaw detection waveform detected by the ultrasonic flaw detector, and digital data A / D converted by the A / D conversion means Capturing means for capturing all the waveforms, extracting means for extracting a plurality of peak waveform data from digital data A / D converted by the A / D converting means, data captured by the capturing means, and the extracting means. Recording means for respectively recording the extracted data, executing the processing by the capturing means and the processing by the extracting means in parallel, and recording by the recording means. Ultrasonic flaw detector according to claim. 2. The extraction means comprises a peak detection circuit for detecting a peak value from A / D-converted digital data and a path length counter for detecting a position at which the peak occurs. Ultrasonic flaw detector. 3. The ultrasonic probe has transducers for a plurality of refraction angles, and control means for performing time-division transmission / reception of a predetermined refraction angle from the ultrasonic probe. The ultrasonic flaw detector according to claim 1, wherein