JP2003004712A - Ultrasonic flaw detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the abnormal place in a test object by detecting the ultrasonic signal propagated through the test object even with respect to a test object large in the attenuation of ultrasonic waves. SOLUTION: The ultrasonic flaw detector has a transmission part 41 for transmitting a transmission signal to a transmitter 2 for transmitting ultrasonic waves to the test object 1, a receiving part 42 for receiving the receiving signal from the receiver 3 for receiving ultrasonic waves propagated through the test object 1 and a signal processing part 5. The transmission part 41 has a transmission signal generating function for generating the transmission signal on the basis of a serially modulated code series and the receiving part 42 has a function for receiving the receiving signal corresponding to the transmission signal. The signal processing part 5 has a correlational processing function for correlationally processing the receiving signal corresponding to the transmission signal using a reference signal prescribed by the serially modulated code series and a detection function for detecting the abnormal place in the test object from the result based on correlationally processing in a plurality of cases wherein the arrangement position of at least either one of the transmitter and the receiver is different.

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 for detecting abnormal points in a test body,
In particular, the sound velocity distribution in the test body where the attenuation of ultrasonic waves is large is estimated, and the abnormal portion is detected from the estimation result.

[0002]

2. Description of the Related Art Conventionally, as this type of ultrasonic flaw detector,
Reference [1] (Adachi et al., "Development of an ultrasonic sonic CT system used to investigate the health of a building", SI Method US99-9, p.
p. 7-14). FIG. 6 is a diagram showing a part of the configuration of the ultrasonic flaw detector described in Document [1]. In FIG. 6, 1 is a test body, and in Reference [1], it is a wooden pole. Reference numeral 2 is a transmitter for transmitting ultrasonic waves, 3 is a receiver for receiving ultrasonic waves, and 9 is an abnormal portion in the test body 1.

In the literature [1], a transmitter 2 and a receiver 3 are provided.
The ultrasonic waves are transmitted and received by the method, the propagation time of the ultrasonic waves in a plurality of propagation paths of the wooden pole is measured, and the sound velocity distribution of the wooden pole cross section is estimated from these propagation times to diagnose the wooden pole.

[0004]

In the ultrasonic flaw detector described in the document [1], a test piece called a wooden pole, which has a large attenuation of ultrasonic waves, is used. Therefore, the transmitter 2 and the receiver 3
The level of the received signal from the receiver 3 is low depending on the arrangement positions of and. At such an arrangement position, the desired signal is buried in noise such as system noise or external noise generated in the ultrasonic flaw detector, so that the received signal cannot be detected and the propagation time at this arrangement position cannot be measured.

The present invention has been made in view of the above circumstances, and by performing signal processing for improving the SN ratio, an ultrasonic signal propagated in the test body even in a test body having a large attenuation of ultrasonic waves. The present invention provides an ultrasonic flaw detector having a function of detecting an abnormal point and detecting an abnormal portion in a test body.

[0006]

An ultrasonic flaw detector according to the present invention includes a transmitter for transmitting a transmission signal to a transmitter for transmitting ultrasonic waves to a test body, and an ultrasonic wave propagated in the test body. It has a receiving unit for receiving a reception signal from a receiver to be received, and a signal processing unit, and the transmission unit has a transmission signal generation function for generating a transmission signal based on a code sequence subjected to sequence modulation. The receiving unit has a function of receiving a reception signal corresponding to the transmission signal, and the signal processing unit uses the reference signal defined by the sequence-modulated code sequence to perform reception corresponding to the transmission signal. Correlation processing function for correlating signals, and detection function for detecting an abnormal point in the test body from the result based on the correlation processing in the case where the arrangement positions of at least one of the transmitter and the receiver are different. And It is intended to.

The sequence-modulated code sequence is a plurality of complementary sequences or complementary sequences, and the transmitting section generates a plurality of transmission signals based on the plurality of complementary sequences or complementary sequences. And the receiver has
The signal processing unit has a function of receiving received signals corresponding to the plurality of transmission signals, and the signal processing unit uses the plurality of reference signals defined by the plurality of complementary sequences or complementary sequences to transmit the plurality of transmission signals. It has a correlation processing function of correlating the received signals corresponding to the signals and an addition function of adding the results of a plurality of correlation processes.

Further, the detection function is to detect an abnormal portion in the test body by using the amplitude peak value of the ultrasonic wave propagated from the transmitter to the receiver.

Further, the detection function is to detect an abnormal portion in the test body from the amplitude peak value in a plurality of cases in which at least one of the transmitter and the receiver is arranged at different positions.

Further, the detecting function measures the attenuation rate distribution in the test body from the amplitude peak value in a plurality of cases in which at least one of the transmitter and the receiver is arranged at different positions, and the attenuation rate is measured. The abnormal part in the test body is detected from the distribution measurement result.

Further, the detection function is to detect an abnormal portion by using the propagation time of the ultrasonic wave from the transmitter to the receiver.

Further, the detection function is to detect an abnormal portion in the test body from the propagation time when there are a plurality of different arrangement positions of at least one of the transmitter and the receiver.

Further, the detecting function measures the sound velocity distribution in the test body from the propagation time in a plurality of cases in which at least one of the transmitter and the receiver is arranged at different positions. It has a function of detecting an abnormal portion in the test body from the result.

Further, it has a scanning mechanism section for operating the transmitter and the receiver to dispose them on the test body.

Further, it has a function of transmitting and receiving to and from the plurality of transmitters and the plurality of receivers.

Further, the oscillator having the transmitter and the receiver, and performing electroacoustic conversion in the transmitter and the receiver is a ferrite magnetostrictive oscillator.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. An ultrasonic flaw detector according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a first embodiment of the present invention.
3 is a block diagram showing the configuration of an ultrasonic flaw detector according to FIG.
In FIG. 1, 1 is a test body, 2 is a transmitter for transmitting ultrasonic waves to the test body 1, and 3 is a receiver for receiving the ultrasonic waves propagated in the test body 1. Reference numeral 4 denotes a transmission / reception unit, which has a transmission unit 41 and a reception unit 42. Reference numeral 5 is a signal processing unit, 6 is a display unit, 7 is a control unit, 8 is a scanning mechanism unit, 9 is an abnormal portion of the test body 1, and the ultrasonic flaw detector 10 is a transmitter / receiver unit 4 thereof.
1, a signal processing unit 5, a display unit 6, a control unit 7, and a scanning mechanism unit 8.

Further, R1, R2 and R3 are propagation paths of ultrasonic waves propagating through the test body 1, and the propagation paths are determined by the arrangement positions of the transmitter 2 and the receiver 3. FIG. 1 shows the case where the ultrasonic waves are propagated and received on the route R2 and the route R3. The route R1 has an abnormal point 9
Is a propagation route in which the abnormal portion 9 is present. The route R3 is another propagation route when the ultrasonic wave propagating through the route R2 is at the same arrangement position of the transmitter 2 and the receiver 3 as when the ultrasonic wave is transmitted and received.

In FIG. 1, the test body 1 is, for example, concrete, and is a solid known to have a large attenuation of ultrasonic waves propagating in the test body 1. The abnormal portion 9 is, for example, a junker.

In the present invention, the ultrasonic wave is used as a term indicating a sound wave or an elastic wave having a high frequency that is inaudible to the human ear, but the frequency is not particularly specified in the present invention. That is, the term "ultrasonic wave" in the present invention includes not only sound waves and elastic waves having a frequency higher than the upper limit of the frequency audible to the human ear, but also sound waves and elastic waves having a frequency lower than the upper limit. It also includes the meaning of waves and, of course, the meaning of acoustic waves and elastic waves at frequencies lower than the lower limit of the frequencies that can be heard by the human ear.

In FIG. 1, a transmitter 2 and a receiver 3 are arranged so that the propagation time of ultrasonic waves can be measured for a certain path that crosses the test body 1. Also, the transmitter 4
1 has a transmission signal generating function of generating a plurality of transmission signals based on a plurality of complementary sequences, and the receiving section 42 has a function of receiving the reception signals corresponding to the plurality of transmission signals. Further, the signal processing unit 5 uses a plurality of reference signals defined by the plurality of complementary sequences to perform a correlation processing function on each of the reception signals corresponding to the plurality of transmission signals, and a plurality of correlation processings. And an addition function for adding the results of

Incidentally, the "plurality of complementary sequences" in the present invention,
"Generate multiple transmit signals based on multiple complementary sequences",
The words "reference signal" and "correlation process" refer to "a plurality of complementary sequences" and "a plurality of transmission signals based on a plurality of complementary sequences" described in Document [2] (Japanese Patent Publication No. 7-85076). , "Reference signal" and "correlation process".

In FIG. 1, the display unit 6 is a signal processing unit 5.
The processing result in 1 is displayed, and the ultrasonic flaw detection result for the test body 1 is displayed. Further, in FIG. 1, the scanning mechanism unit 7
Has a function of scanning the transmitter 2 and the receiver 3 and arranging them at a predetermined arrangement position.

In FIG. 1, the control unit 8 includes a transmitting / receiving unit 4,
Control signals are sent to and received from the signal processing unit 5, the display unit 6, and the scanning mechanism unit 7 to control these operations.

In FIG. 1, the control unit 8 includes a transmission / reception unit 4,
It is connected to the signal processing unit 5, the display unit 6, and the scanning mechanism unit 7. The display unit 6 is connected to the signal processing unit 5.
The signal processing unit 5 is connected to the transmitting / receiving unit 4.

Now, the operation of the ultrasonic flaw detector shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a flowchart regarding the operation of the ultrasonic flaw detector shown in FIG.

First, the control section 8 transmits a control signal for operating the transmission / reception section 4, the signal processing section 5, the display section 6, and the scanning mechanism section 7 (step S21). Next, the scanning mechanism 7 arranges the transmitter 2 and the receiver 3 at predetermined positions (step S22). At this time, although not shown in the figure,
A transmitter 2 is provided by a position detection sensor included in the scanning mechanism unit 7.
The position of the receiver 3 on the test body 1 is detected, and this information is stored in the signal processing unit 5 via the control unit 8. The signal processing unit 5 calculates the separation distance between the transmitter 2 and the receiver from the positions of the transmitter 2 and the receiver 3 on the test body 1, and stores this value in a memory (not shown).

Next, in the transmitting / receiving section 4, one of a plurality of complementary sequences
Choose one and determine the transmitted signal based on this complementary sequence,
A transmission signal is generated (step S23). At this time, the parameters of the signal (hereinafter referred to as the basic signal) corresponding to 1 bit of the plurality of complementary sequences are the carrier frequency, the number of carrier repetitions (the number of burst signals), and the shape of the window function such as Gaussian window or Hanning window. Etc. Here, in the plurality of transmission signals generated, the basic signal is made to correspond to the positive sign of the unit bits of the plurality of complementary sequences, and the negative signal of the unit bits of the plurality of complementary sequences is made to correspond to the basic signal.
The waveform multiplied by 1 may be used as the corresponding waveform.

Next, the transmission signal is transmitted to the transmitter 2. The transmitter / receiver 2 performs electroacoustic conversion of this transmission signal, and the test body 1
The ultrasonic wave is transmitted to (step S24). The transmitted ultrasonic wave propagates through the test body 1 and is received by the receiver 3 (step S25). The ultrasonic wave received by the receiver 3 is electroacoustic converted into an electric signal and output as a reception signal.

Next, in the signal processing section 5, the received signal from the receiver 3 is subjected to correlation processing using the transmitted reference signal defined by the complementary sequence (step S26). The transmission signal itself or the transmission signal is used as the reference signal.
And a signal that has passed through a filter having a frequency response characteristic that the receiver 3 has in total transmission and reception.

Next, the procedure from step S23 to step S26 is repeated by changing the complementary sequence selected at the time of transmission until all of the plurality of complementary sequences have been selected (step S2).
7, S28), the obtained result is stored in a sequential memory (not shown). Next, when all of the plurality of complementary sequences have been selected, the results of a plurality of correlation processes on the memory are added to obtain a composite compressed pulse (step S29).

A composite compressed pulse is obtained by the operations from step S23 to step S29. This situation will be described with reference to FIGS. Here, as an example of a plurality of complementary sequences, the following sequences 1 to 4 in which the number of sequences is 4 and the sequence length is 5 are selected. It should be noted that 5 bits of Gaussian burst waves are associated with 1 bit of a plurality of complementary sequences. Series 1: --- +-Series 2: --- ++ Series 3: --- +-Series 4: --- +-+

FIG. 3 shows received signals corresponding to each series.
FIG. 3A is a transmission / reception signal regarding the sequence 1, and FIG.
3B is a transmission / reception signal related to the sequence 2, and FIG.
Is a transmission / reception signal for sequence 3, and FIG. 3 (d) is a transmission / reception signal for sequence 4. The waveforms of the transmission signal and the reception signal propagating through the test body 1 and received are the same.

FIG. 4 shows the result of correlation processing of the received signal of FIG. 3 with the transmitted signal. FIG. 4A is a result of performing correlation processing on the reception signal of FIG. 3A with the transmission signal.
3B is a result of correlation processing of the reception signal of FIG. 3B with a transmission signal, and FIG. 4C is a result of correlation processing of the reception signal of FIG. 3C with a transmission signal, FIG.4 (d) is
It is a result of performing correlation processing on the reception signal of FIG. 3D with the transmission signal. Further, FIG. 5 shows the result of addition processing of the correlation processing results shown in FIGS. 4 (a) to 4 (d).

As shown in FIGS. 3 to 5, step S2
By performing the processing corresponding to 3 to step S29, the energy distributed on the time axis in FIG. 3 is concentrated in the time range corresponding to 1 bit of the plurality of complementary sequences, and a high peak composite compressed pulse is obtained. . As a result, the S / N ratio is
The ratio corresponding to the number of sequences × sequence length, in this case, is improved by 20 times.

As described above, the same effects as those described in the reference [2] can be obtained for the received signal received by the receiver 3 by the processing of steps S23 to S29, but especially the test sample The range side lobe is set to 0 even when the attenuation of the ultrasonic wave in 1 is large and the desired signal is buried in the system noise of the ultrasonic flaw detector and detection is difficult.
It is possible to obtain the effect that the S / N ratio can be improved and the reflection signal from the abnormal portion 9 can be detected while maintaining the above condition.

It is to be noted that, after a received signal by an ultrasonic wave directly propagated from the transmitter 2 to the receiver 3, for example, an ultrasonic wave propagated by the route R2 shown in FIG. 1, it is propagated by another route such as the route R3 shown in FIG. When the received signal by the ultrasonic wave is superimposed,
Due to this superposition, the peak time of the composite compressed pulse of the component directly propagated from the transmitter 2 to the receiver 3 deviates, and the measurement accuracy deteriorates when the propagation time is obtained from the peak time.
However, according to the first embodiment of the present invention, since the range side lobe can be set to 0, it is possible to prevent the above-described superposition of the received signal and the deterioration of the propagation time measurement accuracy.

The words "composite compression pulse" and "range sidelobe" in the present invention have the same meanings as the words "composite compression pulse" and "range sidelobe" described in document [2]. .

Next, the propagation time of the ultrasonic wave propagating between the transmitter 2 and the receiver 3 is obtained from the rise time or peak time of the composite compressed pulse obtained in step S29 (step S30).

Next, steps S22 to S30
Is repeated (step S31). At this time, the arrangement position of at least one of the transmitter 2 and the receiver 3 is sequentially changed to perform transmission / reception on different propagation paths. In addition,
The propagation time obtained in step S30 is sequentially stored in the memory.

Next, in the signal processor 5, step S
The abnormal portion 9 is detected from the results obtained up to 31.
At this time, even for the propagation paths having the same length, for example, the path R1 and the path R2 in FIG. 1, the propagation time differs depending on the presence or absence of the abnormal portion 9. This is because the propagation speed of ultrasonic waves is different between the sound part in the test body 1 and the part where the abnormal part 9 exists. For example, the case where the test body 1 is concrete and the abnormal portion 9 is a junker is applicable to this.

Therefore, if the sound velocity of the ultrasonic wave in the sound part of the test body 1 and the distance from the transmitter 2 to the receiver 3 are known, the propagation time of the ultrasonic wave in the sound part (for example, the route R1) is calculated. By comparing the calculated value with the value obtained by the measurement, it can be detected that the route R1 is healthy and the abnormal portion 9 exists on the route R2.

As described above, if the sound velocity of the ultrasonic wave and the distance from the transmitter 2 to the receiver 3 in the sound part of the test body 1 are known, the propagation is performed for a plurality of received signals whose arrangement positions are changed. It is possible to perform binary detection regarding the presence / absence of the abnormal portion 9 in the propagation path of the ultrasonic wave from the transmitter 2 to the receiver 3 without comparing the times.

If the sound velocity of the ultrasonic wave in the sound part of the test body 1 is unknown and the distance from the transmitter 2 to the receiver 3 is known, the received signals in a plurality of arrangement positions are changed. , The average sound velocity in the propagation path of the ultrasonic wave from the transmitter 2 to the receiver 3 is calculated by (distance from the transmitter 2 to the transmitter 3) / (propagation time), and the average sound velocity in each case is compared to obtain the average sound velocity. By detecting the propagation path that locally changes, it is possible to detect the presence or approximate position of the abnormal portion 9.

It is more preferable that the signal processing unit 5 has a function of estimating the sound velocity distribution in the test body 1 from the propagation times of the plurality of propagation paths obtained by the operations up to step S210. The estimation method is described in reference [3] (Nagai, "Ultrasonic holography-Image by aperture synthesis-", published by Nikkan Kogyo Shimbun, pp. 90-12.
0, published June 30, 1989, and reference [4] (RK Mueller et al., “Reconstructive Tomo”).
gyaphy and Applications to Ultrasonics ", Proceedin
g of The IEEE, Vol. 67, No. 4, April 1979), for example, ART (Algebraic Reconstruction)
Techniques) may be used. If there is a function for estimating such a sound velocity distribution, the abnormal point 9
More detailed information on the size and position of the can be obtained.

Abnormal point 9 obtained in the signal processing unit 5
The detection result of is displayed on the display unit 6 (step S
32). The display unit 6 not only displays these waveforms, but also inspects the state of the test body 1 based on these waveforms. For example, the presence or absence of the abnormal portion 9, the size of the abnormal portion 9, and the abnormal portion Information such as the shape of 9 or the position of the abnormal portion 9 may be displayed.

In the first embodiment of the present invention, the case where the sequence-modulated code sequence is a plurality of complementary sequences is shown as a sequence to be used. However, this sequence is a complementary sequence described in the document [2]. Even if there is no range sidelobe
It is possible to obtain the effect of improving the S / N ratio and detecting the received signal from the receiver 3 while maintaining the above condition. Further, even if a transmission signal based on a sequence-modulated code sequence other than a plurality of complementary sequences and complementary sequences, for example, a sequence such as a pseudo-random sequence is used, the S / N
The effect that the ratio is improved and the received signal from the receiver 3 can be detected is still obtained.

In the first embodiment of the present invention, the number of the transmitters 2 and the number of the receivers 3 are one, respectively,
If the number is set to two or more and the propagation times of a plurality of propagation paths are measured at one time, there is an effect that the inspection time can be shortened and the cost required for the inspection can be reduced.

In the first embodiment of the present invention, the abnormal portion 9 is detected by using the propagation time of the ultrasonic wave from the transmitter 2 to the receiver 3.

Here, a method of detecting the abnormal portion 9 using another measurement item of the ultrasonic wave propagating from the transmitter 2 to the receiver 3 will be described. For example, when the test body 1 is concrete and the abnormal portion 2 is a junker, the ultrasonic waves propagating through the test body 1 have different attenuation rates between the healthy portion and the abnormal portion. Therefore, in the first embodiment of the present invention, the abnormal point 9 may be detected using the amplitude peak value of the ultrasonic wave propagated from the transmitter 2 to the receiver 3 instead of the propagation time. In this case, the first embodiment of the present invention
In the same procedure, the item to be measured in 2 is replaced with the amplitude peak value from the propagation time. In addition, if the attenuation rate distribution of ultrasonic waves is estimated from the plurality of amplitude peak values obtained when the positions of the transmitter 2 and the receiver 3 are changed, and the abnormal portion 9 is detected based on the estimation result. ,
This is more preferable because detailed information regarding the position and size of the abnormal portion 9 can be obtained. In this case, the same method as the X-ray tomography may be used as the method of estimating the attenuation rate distribution.

In the first embodiment of the present invention,
In order to obtain a composite compressed pulse having a range side lobe of 0, the conditions for transmitting and receiving a plurality of signals based on a plurality of complementary sequences are the same, that is, the transmitter 2 and the receiver 3 are in the same contact state with the test body 1. Need to be satisfied. In the first embodiment of the present invention, the transmitter 2 and the receiver 3 are mechanically arranged on the test body 1 by using the scanning mechanism unit 7. Therefore, the transmitter 2 and the receiver 3 are tested. It is easy to keep the contact state with 1 constant while transmitting and receiving a plurality of transmission signals based on a plurality of complementary sequences. Therefore, there is an effect that the range side lobe can be easily set to 0 when the addition process for obtaining the combined compressed pulse is performed.

If the condition for obtaining the composite compressed pulse having the range side lobe of 0 can be satisfied, the scanning mechanism section 7 is omitted, and a human hand is used to test the transmitter 2 and the receiver 3. You may perform arrangement | positioning to 1. At this time, the arrangement positions of the transmitter 2 and the receiver 3 on the test body 1 and the distance between the transmitter 2 and the receiver 3 are sequentially measured and manually input to the control unit 8, and this information is signaled. It may be sent to the processing unit 5 and sequentially stored in the memory. As a result, the structure of the device is simplified and the cost of the entire device is reduced.

Further, in the first embodiment of the present invention, since the test body 1 has a large attenuation of ultrasonic waves, the carrier frequency of the ultrasonic waves to be transmitted and received is 2 MHz which is used in ordinary ultrasonic flaw detection. Frequently, the frequency is lower than 5 MHz, for example, 100 kHz. In the case of transmitting and receiving a signal having a carrier frequency in this frequency band, although not shown, as a vibrator used for electroacoustic conversion in the transmitter 2 and the receiver 3, a ferrite magnetostriction that is cheaper than other vibrators is used. If the vibrator is used, even when the ultrasonic flaw detector 10 is configured to include the transmitter 2 and the receiver 3, the cost of the entire device can be reduced. This effect is particularly great when the number of transmitters 2 and receivers 3 is plural.

[0054]

As described above, according to the present invention, the transmitter for transmitting the transmission signal to the transmitter for transmitting the ultrasonic wave to the test body, and the receiving unit for receiving the ultrasonic wave propagating in the test body. A reception unit for receiving a reception signal from a child, and a signal processing unit, wherein the transmission unit has a transmission signal generation function for generating a transmission signal based on a sequence-modulated code sequence, and the reception unit The unit has a function of receiving a reception signal corresponding to the transmission signal, and the signal processing unit correlates the reception signal corresponding to the transmission signal using a reference signal defined by the sequence-modulated code sequence. It has a correlation processing function to process, and a detection function to detect an abnormal part in the test body from the result based on the correlation processing in the case where the arrangement positions of at least one of the transmitter and the receiver are different. So try Even if the ultrasonic wave in the body is greatly attenuated and the desired signal is buried in the system noise of the ultrasonic flaw detector and is difficult to detect, the S / N ratio is improved while the range side lobe is kept at 0, resulting in abnormalities. The effect that the reflection signal from the location can be detected is obtained.

Further, the sequence-modulated code sequence is a plurality of complementary sequences or complementary sequences, and the transmission section generates a plurality of transmission signals based on the plurality of complementary sequences or complementary sequences. And the receiver has
The signal processing unit has a function of receiving received signals corresponding to the plurality of transmission signals, and the signal processing unit uses the plurality of reference signals defined by the plurality of complementary sequences or complementary sequences to transmit the plurality of transmission signals. The S / N ratio is improved while keeping the range sidelobe at 0, since it has a correlation processing function for correlating the received signals corresponding to the signals and an addition function for adding the results of a plurality of correlation processes. Receiver 3
It is possible to obtain the effect that it becomes possible to detect the received signal from.

Further, with the above detection function, it is possible to detect an abnormal portion in the test body by using the amplitude peak value of the ultrasonic wave propagated from the transmitter to the receiver.

Further, by the detection function, it is possible to detect an abnormal portion in the test body from the amplitude peak value in the case where the arrangement positions of at least one of the transmitter and the receiver are different.

Further, by the detection function, the attenuation rate distribution in the test body is measured from the amplitude peak value in a plurality of cases in which at least one of the transmitter and the receiver is arranged at different positions, and the attenuation rate is measured. From the distribution measurement result, it is possible to detect an abnormal portion in the test body.

Further, with the detection function, it is possible to detect an abnormal portion by using the propagation time of the ultrasonic wave from the transmitter to the receiver.

Further, by the detection function, it is possible to detect an abnormal portion in the test body from the propagation time when there are a plurality of arrangement positions of at least one of the transmitter and the receiver.

With the detection function, the sound velocity distribution in the test body is measured from the propagation time when there are a plurality of different arrangement positions of at least one of the transmitter and the receiver, and the sound velocity distribution is measured. From the result, it is possible to detect an abnormal portion in the test body.

Further, by having a scanning mechanism section for operating the transmitter and the receiver to arrange them on the test body, the contact state of the transmitter and the receiver on the test body can be made into a plurality of complementary series. It becomes easy to keep constant during transmission and reception of a plurality of transmission signals based on it, and there is an effect that the range side lobe can be easily set to 0 when performing addition processing for obtaining a composite compressed pulse.

Further, by having a function of transmitting / receiving to / from the plurality of transmitters and the plurality of receivers, it is possible to reduce the inspection time by measuring the propagation time for a plurality of propagation paths at a time. There is an effect that the cost required for can be reduced.

Further, by using a ferrite magnetostrictive vibrator as the vibrator having the transmitter and the receiver, and performing electroacoustic conversion in the transmitter and the receiver, the cost of the entire apparatus can be reduced.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram for explaining the operation of the ultrasonic flaw detector according to Embodiment 1 of the present invention.

FIG. 3 is an explanatory diagram for explaining the operation of the ultrasonic flaw detector according to Embodiment 1 of the present invention.

FIG. 4 is an explanatory diagram for explaining the operation of the ultrasonic flaw detector according to Embodiment 1 of the present invention.

FIG. 5 is a schematic diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 1 of the present invention.

FIG. 6 is a schematic diagram for explaining a conventional ultrasonic flaw detector.

[Explanation of symbols]

1 test body, 2 transmitters, 3 receivers, 4 transceivers,
41 transmitter, 42 receiver, 5 signal processor, 6 display, 7 scanning mechanism, 8 controller, 9 abnormal location, 1
0 Ultrasonic flaw detector.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichiro Misu             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Shuzo Waka             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F term (reference) 2G047 AA10 BA01 BC02 BC03 BC07                       CA02 GA13 GG19 GG24 GG34                       GG36 GG38

Claims (11)

[Claims] 1. A transmitter for transmitting a transmission signal to a transmitter for transmitting ultrasonic waves to a test body, and a receiver for receiving a reception signal from a receiver for receiving ultrasonic waves propagated in the test body. And a signal processing unit, wherein the transmission unit has a transmission signal generation function for generating a transmission signal based on a sequence-modulated code sequence, and the reception unit is a reception signal corresponding to the transmission signal. A signal processing unit, the signal processing unit, a correlation processing function of performing a correlation process on a received signal corresponding to the transmission signal by using a reference signal defined by the code sequence subjected to sequence modulation, and the transmitter. An ultrasonic flaw detection device having a detection function of detecting an abnormal portion in the test body based on a result based on the correlation processing in a case where a plurality of positions of at least one of the receivers are different. 2. The ultrasonic flaw detector according to claim 1, wherein the sequence-modulated code sequence is a plurality of complementary sequences or complementary sequences, and the transmitting unit is based on the plurality of complementary sequences or complementary sequences. The reception unit has a function of generating a plurality of transmission signals, the reception unit has a function of receiving reception signals corresponding to the plurality of transmission signals, and the signal processing unit has a plurality of reception units. A correlation processing function for correlating received signals corresponding to the plurality of transmission signals by using a plurality of reference signals defined by a sequence or a complementary sequence, and an addition function for adding the results of the plurality of correlation processes. An ultrasonic flaw detection apparatus having: 3. The ultrasonic flaw detector according to claim 1 or 2, wherein the detection function uses an amplitude peak value of ultrasonic waves propagated from the transmitter to the receiver to detect an abnormal location in a test body. An ultrasonic flaw detector characterized by performing detection. 4. The ultrasonic flaw detector according to any one of claims 1 to 3, wherein the detection function has a plurality of amplitudes in a case where the positions of at least one of the transmitter and the receiver are different. An ultrasonic flaw detector, comprising detecting an abnormal portion in a test body from a peak value. 5. The ultrasonic flaw detection apparatus according to claim 4, wherein the detection function is based on the amplitude peak value in a plurality of cases in which at least one of the transmitter and the receiver has a different arrangement position. An ultrasonic flaw detector characterized by measuring an attenuation rate distribution in a body and detecting an abnormal portion in the test body from the measurement result of the attenuation rate distribution. 6. The ultrasonic flaw detector according to claim 1, wherein the detection function detects an abnormal portion by using a propagation time of ultrasonic waves from the transmitter to the receiver. Ultrasonic flaw detector. 7. The ultrasonic flaw detector according to any one of claims 1, 2, and 6, wherein the detection function is a plurality of cases in which at least one of the transmitter and the receiver has a different arrangement position. An ultrasonic flaw detector characterized by detecting an abnormal portion in a test body from the propagation time. 8. The ultrasonic flaw detector according to claim 7, wherein the detection function is based on the propagation time in a plurality of cases in which at least one of the transmitter and the receiver is arranged at different positions. An ultrasonic flaw detector having a function of measuring a sound velocity distribution inside and detecting an abnormal portion in the test body from a measurement result of the sound velocity distribution. 9. The ultrasonic flaw detector according to claim 1, further comprising a scanning mechanism section for operating the transmitter and the receiver to dispose them on the test body. Ultrasonic flaw detector. 10. The ultrasonic flaw detector according to claim 1, wherein the ultrasonic flaw detector has a function of transmitting and receiving to and from the plurality of transmitters and the plurality of receivers. . 11. The ultrasonic flaw detector according to claim 1, wherein the vibrator has the transmitter and the receiver, and the vibrator for performing electroacoustic conversion in the transmitter and the receiver is ferrite. An ultrasonic flaw detector which is a magnetostrictive oscillator.