JP3680982B2 - Characterization device and method for acoustic discontinuity - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an apparatus and method for determining the properties of acoustic discontinuities, for example, an ultrasonic flaw detection test using an oblique flaw detection method, and more particularly to classification of flaws in a specimen.
  Here, for convenience of explanation, an ultrasonic flaw detection test using the oblique flaw detection method will be described as an example.
[0002]
[Prior art]
  A conventional ultrasonic flaw detection test of this type will be described with reference to FIG. FIG. 41 shows “New Nondestructive Test Handbook” (Japan) Non-Destructive Inspection Association of Japan, Nikkan Kogyo Shimbun, October 15, 1992, first edition, first print, pages 297 to 306 (hereinafter referred to as “Documents”). It is a figure which shows the outline | summary of the ultrasonic flaw test using the bevel flaw detection method described in A). In FIG. 41, 7 is a probe, 71 is a vibrator, 72 is a wedge, 1 is a test body, 3 is a flaw detection surface, and 6 is a flaw. In Document A, “flaw” is indicated as “defect”, but here it is described as “flaw”. Further, in the drawing of document A, “incident point”, “refraction angle” and “WF” representing the beam path are shown, but they are omitted because they are not necessary for the description here.
[0003]
  First, an ultrasonic flaw detection test using a general oblique flaw detection method using one probe will be described with reference to FIG. Although not shown in FIG.Probe 7Is connected to an ultrasonic flaw detector and applies an electrical excitation signal to the vibrator 71. The vibrator 71 converts an electrical signal into an ultrasonic wave, and a longitudinal wave propagates in the wedge 72. The longitudinal wave propagating in the wedge 72 reaches the flaw detection surface 3, becomes a transverse wave by mode conversion, and propagates in the specimen 1 in a direction determined by Snell's law. In addition, the thin continuous line in a figure represents the ultrasonic beam, and so on.
[0004]
  The transverse wave that reaches the flaw 6 is scattered, and a part of the scattered wave propagates in the direction of the probe 7. Then, it becomes a longitudinal wave again by mode conversion on the flaw detection surface 3 and propagates in the wedge 72. In the vibrator 71, the longitudinal wave propagating in the wedge 72 is converted into an electric signal and transmitted to the ultrasonic flaw detector as a flaw echo.
[0005]
  The ultrasonic flaw detector has a display, and a defect 6 in the test body 1 is detected by displaying a defect echo on the display. The above is the outline of the ultrasonic flaw detection test using the oblique flaw detection method.
[0006]
  Now, a method for classifying the properties of the flaw 6 detected as described above will be described with reference to FIGS. 42 shows “ultrasonic flaw detection test”, Japan Non-destructive Inspection Association, Japan Non-destructive Inspection Association, 1990, pages 117-118 (hereinafter abbreviated as “Document B”). It is a figure quoted from the above, and is a figure when the appearance of oblique flaw detection of the welded portion is viewed from above the specimen 1. In FIG. 42, 7a to 7c are probes, 74 is a welded portion, and 75 is a surface flaw present in the welded portion. In FIG. 42, the planar flaw 75 is shown as a “line”, but this is a two-dimensional figure, and is actually a “surface” that extends in the direction perpendicular to the paper surface. . Further, the planar flaw 75 may be open to the flaw detection surface 3 (the surface of the test body 1) of the test body 1 or may be present in the test body 1. In FIG. 42, such a planar flaw 75 is projected onto the surface of the test body 1 and shown.
[0007]
  In FIG. 42, when the oblique angle flaw detection is performed using the probe 7a, the ultrasonic beam radiated from the probe 7a to the test body and the surface flaw 75 are perpendicular to each other, and thus the surface flaw 75 is scattered. Many components of the scattered wave propagate in the direction of the probe 1a. Therefore, when oblique angle flaw detection is performed using the probe 7a, the height of the flaw echo appearing on the display device is increased. This is shown in FIG.
[0008]
  FIG. 43 shows a flaw detection figure in the case where oblique angle flaw detection is performed using the probe 7a, which is displayed in an A scope. In FIG. 43, 76 is a transmission pulse, and 77 is a flaw echo when flaw detection is performed using the probe 7a.
[0009]
  On the other hand, in FIG. 42, when oblique flaw detection is performed using the probe 7b, the ultrasonic beam radiated from the probe 7b is incident obliquely on the surface flaw. For this reason, many components of the scattered wave scattered by the planar flaw 75 do not propagate in the direction of the probe 7b. Therefore, when oblique angle flaw detection is performed using the probe 7b, the height of the flaw echo appearing on the display device is reduced. This situation is shown in FIG. FIG. 44 shows a flaw detection figure similar to the case of FIG. 43 when oblique angle flaw detection is performed using the probe 7b. In FIG. 44, 76 is a transmission pulse, and 77 is a flaw echo when flaw detection is performed using the probe 7b.
[0010]
  In FIG. 42, in the case where the oblique angle flaw detection is performed using the probe 7c, the height of the flaw echo in the flaw detection figure is reduced as in the case where the probe 7b is used.
[0011]
  Thus, the height of the flaw echo from the surface flaw 75 varies greatly depending on the angle of the ultrasonic beam emitted from the probe. This is because the flaw is planar, and the height of the flaw echo becomes large when the ultrasonic beam is incident on the planar flaw perpendicularly. Note that the scanning method for moving the probe to the positions of the probes 7a to 7c in FIG. 42 is called “pendulum scanning”. As a method for changing the angle of the ultrasonic beam radiated from the probe, there is “shoulder scanning” in addition to pendulum scanning. The scanning method of these probes is described in Document A.
[0012]
  When pendulum scanning is performed on a surface flaw, the height of the flaw echo greatly changes as described above. On the other hand, when the shape of the flaw is spherical, the height of the flaw echo hardly changes even if pendulum scanning is performed. This is because the scattered wave scattered by the spherical flaw propagates almost uniformly in almost all directions.
[0013]
  Therefore, when pendulum scanning is performed and the height of the flaw echo changes greatly, the flaw can be estimated as a “plane flaw”. On the other hand, when the height of the flaw echo hardly changes, the flaw can be estimated as a “spherical flaw”. In this way, the properties of the flaw can be classified.
[0014]
  The above is the flaw property classification method described in Document B. Further, methods for classifying flaws in the oblique flaw detection method are also disclosed in JP-A-58-135957, JP-A-62-2228158, JP-A-6-11489, and the like.
[0015]
  In Japanese Patent Application Laid-Open No. 58-135957, first, the echo height is classified by region classification according to Japanese Industrial Standard JIS Z 3060, and then a sectional view (B scope) and a plan view (C scope) are prepared and prepared in advance. By comparing with the reference sectional view pattern and the reference plan view pattern, the flaws are classified.
[0016]
  In Japanese Patent Laid-Open No. 62-228158, vertical flaw detection and oblique flaw detection are performed, and flaw detection is performed by changing the swing angle, and area-type flaws and volume-type flaws are classified.
[0017]
  In Japanese Patent Application Laid-Open No. 6-11489, vertical flaw detection, oblique flaw detection, and surface wave flaw detection are not performed.
[0018]
[Problems to be solved by the invention]
  In the flaw classification method shown in Document B and Japanese Patent Laid-Open No. 62-228158, it is necessary to perform pendulum scanning and swing scanning. Such scanning is usually performed manually. On the other hand, in automatic flaw detection that mechanically scans the probe, many of them are “front-rear scan” that scans the probe in a direction perpendicular to the weld line, and “left-right scan” that is parallel to the weld line. Scanning ". Note that these scanning methods are described in Document A.
[0019]
  When “pendulum scanning” or “swing swing scanning” is performed in automatic flaw detection, the time for performing a flaw detection test becomes enormous. In addition, the data obtained by the flaw detection test is enormous, and an apparatus for processing this enormous data is required, resulting in an inspection cost.
[0020]
  In the flaw classification method disclosed in JP-A-6-11489, it is necessary to perform vertical flaw detection, oblique flaw detection, and surface wave flaw detection. That is, a flaw detection test by many methods must be performed on one flaw detection location, which requires a lot of time and a lot of inspection costs.
[0021]
  In the flaw classification method disclosed in JP-A-58-135957, it is necessary to classify using three kinds of flaw detection figures, that is, the height of flaw echo, B scope, and C scope. take time.
  As described above, it takes a lot of time and a lot of cost to classify the properties of flaws in the conventional ultrasonic flaw detection test.
[0022]
  The present invention has been made to solve such a problem, and does not perform a pendulum scan or a head swing scan, but performs a flaw detection only by a back-and-forth scan, and performs signal processing on the obtained data, thereby providing a specimen. Characterization device for acoustic discontinuity for classifying flaws in the interior, andJudgment methodIs to provide.
[0023]
[Means for Solving the Problems]
  The property determination device for acoustic discontinuity according to the first invention is driven by a transmission signal, transmits a pulse obliquely to the surface of the object to be measured, and is transmitted by the acoustic discontinuity in the object to be measured. A sensor for receiving an echo for the reflected pulse; scanning means for scanning the sensor on the object to be measured and outputting a spatial position of the sensor; an echo received by the sensor; and a space for the sensor And generating an image of the acoustic discontinuity based on the target position, and the generated imageWhen the number of objects exhibiting an amplitude exceeding a predetermined threshold is 3 and satisfies the condition of being an omnidirectional acoustic discontinuity within the specific range in FIG. Is identified as an acoustic discontinuitySignal processing means.
[0024]
  Also,Second inventionThe condition of the omni-directional acoustic discontinuity is that the positional relationship of those exceeding the three thresholds is substantially equidistant, and is in the middle of those exceeding the three thresholds The position is a condition that the position exists near the bottom surface of the measured object.
[0025]
  In addition, the third invention,A sensor driven by a transmission signal, transmitting a pulse obliquely to the surface of the object to be measured, and receiving an echo for the pulse reflected by an acoustic discontinuity in the object to be measured; and An image of the acoustic discontinuity is generated on the basis of scanning means for scanning the object to be measured and outputting the spatial position of the sensor, echoes received by the sensor, and the spatial position of the sensor. When the number of objects exhibiting an amplitude exceeding a predetermined threshold is two within a specific range in the generated image and the condition of being a directional acoustic discontinuity is satisfied And signal processing means for discriminating that the directional acoustic discontinuity is present.
[0026]
  Also,4th inventionIs characterized in that the directional acoustic discontinuity is a condition in which one of the two thresholds exceeds the bottom surface of the object to be measured. To do.
[0027]
  Also,5th inventionThe image is an image obtained by aperture synthetic signal processing.
[0028]
  Also,6th inventionThe image is an image obtained by B scope display.
[0029]
  7th inventionThe acoustic discontinuity property determination method according to the present invention includes a transmission step of generating a transmission signal and outputting the transmission signal to a sensor, and propagating a pulse through the measured object by the sensor, and an acoustic in the measured object by the sensor. A reception step of receiving the pulse reflected by the discontinuous part as an echo, a movement step of moving the sensor to a predetermined location, and inputting and storing the received echo, and receiving the echo A storage step of inputting and storing the spatial position of the sensor at the time, and the echo and the echo when the echo is receivedSensorWith spatial positionAcoustic discontinuityStatueGenerationAnd the statueWhen the number of objects exhibiting an amplitude exceeding a predetermined threshold is 3 and satisfies the condition of being an omnidirectional acoustic discontinuity within the specific range in FIG. Is identified as an acoustic discontinuitySignal processing step.
[0030]
  Also,Eighth inventionThe condition of the omni-directional acoustic discontinuity is that the positional relationship of those exceeding the three thresholds is substantially equidistant, and is in the middle of those exceeding the three thresholds The position is a condition that the position exists near the bottom surface of the measured object.
[0031]
  In addition, the ninth invention,A transmission step of generating and outputting a transmission signal to a sensor, and propagating a pulse through the measured object by the sensor; and acoustic discontinuity in the measured object by the sensor. A receiving step of receiving the pulse reflected by the continuation unit as an echo, a moving step of moving the sensor to a predetermined location, and inputting and storing the received echo, and at the time of receiving the echo A storage step of inputting and storing the spatial position of the sensor, and generating an image of an acoustic discontinuity using the echo and the spatial position of the sensor when the echo is received, and specifying the image in the image If the number of objects exhibiting an amplitude exceeding a predetermined threshold is 2 and the condition of being a directional acoustic discontinuity is satisfied, the directional acoustic defect is not detected. And a signal processing step for determining that the part is a continuous part.
[0032]
  Also,10th inventionIs characterized in that the directional acoustic discontinuity is a condition in which one of the two exceeding the threshold value is present near the bottom surface of the object to be measured. To do.
[0033]
  Also,Eleventh inventionThe image is an image obtained by aperture synthetic signal processing.
[0034]
  Also,12th inventionThe image is an image obtained by B scope display.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
  An ultrasonic flaw detector and an ultrasonic flaw detection method according to Embodiment 1 of the present invention will be described with reference to the drawings.
[0036]
  FIG. 1 is a diagram showing a configuration of an ultrasonic flaw detector using an oblique flaw detection method according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol shows the same or equivalent part.
[0037]
  In FIG. 1, the ultrasonic flaw detector includes a probe 7 placed on a test body 1, a transmission / reception device 8 connected to the probe 7, and a scanning mechanism unit 9 for the probe 7. Prepare.
[0038]
  In the figure, the transmission / reception device 8 includes a control unit 81, a transmission unit 82, a reception unit 83, a signal processing unit 84, and a position detection unit 85 of the probe 7. The scanning mechanism unit 9 includes a position detection sensor for the probe 7 (not shown).
[0039]
  Further, in the same figure, the probe 7 is connected to a transmission unit 82 and a reception unit 83 by signal lines. The receiving unit 83 is connected to the signal processing unit 84. The position detection unit 85 is connected to the signal processing unit 84. The control unit 81 is connected to the transmission unit 82, the reception unit 83, the signal processing unit 84, the position detection unit 85, and the scanning mechanism unit 9.
[0040]
  Further, in the figure, the scanning mechanism unit 9 is connected to a position detection unit 85. An output signal from the position detection sensor of the scanning mechanism unit 9 is input to the position detection unit 85. Information on the position of the probe 7 detected by the position detector 85 is input to the signal processor 84.
  If the position information of the probe 7 can be obtained only by the signal from the control unit 81 without using the information from the position detection unit 85, the information from the control unit 81 is used. Position information may be input to the signal processing unit 84 using only.
[0041]
  Further, the signal processing unit 84 has a memory therein, although not shown. In this memory, various results calculated and calculated in the signal processing unit 84 are appropriately stored, and input signals input to the signal processing unit 84 are appropriately stored.
[0042]
  Although not shown, a signal indicating the processing status is appropriately input to the control unit 81 from the signal processing unit 84. Based on the input signal, the control unit 81 outputs control signals to the transmission unit 82, the reception unit 83, the signal processing unit 84, the position detection unit 85, and the scanning mechanism unit 9, and controls them.
[0043]
  In FIG. 1, 1 is a test body, 3 is a flaw detection surface of the test body 1, 4 is a bottom surface of the test body 1, and 6 is a flaw in the test body 1.
[0044]
  First, the operation of the ultrasonic flaw detector shown in FIG. 1 will be described. In FIG. 1, an excitation signal is transmitted from the transmitter 82 to the probe 7. With this excitation signal, an ultrasonic pulse is transmitted from the probe 7, and the ultrasonic pulse propagates into the test body 1. The ultrasonic pulse propagating through the test body 1 is reflected by the flaw 6, propagates again through the test body 1, and is received as an echo by the probe 7. The echo signal is amplified by the receiving unit 83 and then transmitted to the signal processing unit 84.
[0045]
  On the other hand, as described above, the position information of the probe 7 that has transmitted the ultrasonic pulse and received the echo is input to the signal processing unit 84.
[0046]
  These operations are performed while the probe 7 scans the probe 7 over a predetermined scanning range.
[0047]
  In the signal processing unit 84, aperture synthesis signal processing is executed based on the echo and the position information of the probe 7, and signal processing for image reproduction of the flaw 6 is performed. When the flaw is near the bottom surface 4, echoes are received along various propagation paths, so that a reproduced image obtained by aperture synthetic signal processing is complicated. In particular,
A propagation path in which the ultrasonic pulse excited by the probe 7 is directly applied to the scratch 6 and reflected by the scratch 6 and then directly received.
A propagation path in which the ultrasonic pulse excited by the probe 7 is reflected by the bottom surface 4 and then irradiated to the scratch 6 and reflected by the scratch 6 and then directly received.
A propagation path in which the ultrasonic pulse excited by the probe 7 is directly applied to the scratch 6, reflected by the scratch 6, and then reflected and received by the bottom surface 4.
A propagation path in which the ultrasonic pulse excited by the probe 7 is reflected on the bottom surface 4 and then applied to the scratch 6, reflected by the scratch 6, and then reflected again on the bottom surface 4 and received.
In this way, there are various routes. Hereinafter, the synthetic aperture signal processing and the reproduced image in the oblique flaw detection method will be described together with the echo propagating along these paths.
[0048]
  First, an echo directly received after the ultrasonic pulse excited by the probe 7 is directly applied to the scratch 6 and reflected by the scratch 6 will be described with reference to FIGS. FIG. 2 is a diagram showing a propagation path of echoes directly received after the ultrasonic pulse excited by the probe 7 is directly applied to the scratch 6 and reflected by the scratch 6 in the oblique angle flaw detection method. is there. In the figure, 7A, 7B and 7C indicate the position of the probe when the probe 7 is scanned on the flaw detection surface 3 in the horizontal direction. Reference numerals 10A, 10B, and 10C denote propagation paths of echoes received at the probe positions.
[0049]
  FIG. 3 shows echoes received by propagation along the propagation paths 10A, 10B and 10C. In the figure, 11A, 11B and 11C are echoes excited and received at the probe positions 7A, 7B and 7C.
[0050]
  FIG. 4 shows the state of aperture synthesis signal processing performed by the signal processing unit 84 using echoes propagated along the propagation paths 10A, 10B and 10C and received. In the figure, 12A, 12B, and 12C are lengths corresponding to the beam path lengths of the echoes of 11A, 11B, and 11C. Reference numerals 13A, 13B, and 13C are arcs having lengths 12A, 12B, and 12C corresponding to the beam path as radii and having centers of 7A, 7B, and 7C, respectively.
[0051]
  FIG. 5 assumes that the received echoes 11A, 11B, and 11C are received by propagating along the propagation path as shown in FIG. FIG. 6 is a schematic diagram of a reproduced image obtained when aperture synthesis signal processing is performed when a propagation path of direct reception is assumed. In the figure, reference numeral 14 denotes a portion where the amplitude of the reproduced image is large.
[0052]
  The aperture synthetic signal processing shown in FIG. 5 directly irradiates the flaw 6 and reflects the echo received along the propagation path directly received after being reflected by the flaw 6. After the reflection, the processing is performed assuming that the signal is received along the directly received propagation path. That is, since the propagation path actually followed by the echo is the same as the propagation path assumed in the aperture synthesis signal processing, as shown in FIG. 5, the place where the flaw actually exists and the place where the amplitude of the reproduced image is large Are almost identical.
[0053]
  Next, referring to FIGS. 6 to 9, the ultrasonic pulse excited by the probe 7 is reflected on the bottom surface 4 and then applied to the scratch 6, reflected by the scratch 6 and directly received. While explaining. FIG. 6 shows the propagation of echoes directly received after the ultrasonic pulse excited by the probe 7 is applied to the flaw 6 after being reflected by the bottom surface 4 and reflected by the flaw 6 in the oblique angle flaw detection method. It is the figure which showed the path | route. In the figure, reference numerals 15A, 15B and 15C denote propagation paths of echoes received at the probe positions.
[0054]
  FIG. 7 shows echoes received by propagation along propagation paths 15A, 15B and 15C. In the figure, 16A, 16B and 16C are echoes excited and received at the probe positions 7A, 7B and 7C.
[0055]
  FIG. 8 shows the state of aperture synthesis signal processing performed by the signal processing unit 84 using echoes propagated along the propagation paths 15A, 15B and 15C and received. In the figure, 17A, 17B and 17C are lengths corresponding to the beam path lengths of the echoes 16A, 16B and 16C. 18A, 18B, and 18C are circular arcs having a radius of 17A, 17B, and 17C and a center of 7A, 7B, and 7C.
[0056]
  9 assumes that the received echoes 16A, 16B and 16C are received along the propagation path as shown in FIG. 2, that is, directly irradiates the flaw 6 and is reflected by the flaw 6. FIG. 6 is a schematic diagram of a reproduced image obtained when aperture synthesis signal processing is performed when a propagation path of direct reception is assumed. In the figure, 19 is a portion where the amplitude of the reproduced image is large.
[0057]
  The aperture synthetic signal processing shown in FIG. 8 irradiates the scratch 6 after the ultrasonic pulse excited by the probe 7 is reflected by the bottom surface 4 and reflects the echo directly received after being reflected by the scratch 6. It shows a state in which processing is performed on the assumption that the defect 6 is directly irradiated, reflected by the defect 6, and then received along a propagation path (propagation path shown in FIG. 2) that is directly received. That is, the propagation path actually followed by the echo is different from the propagation path assumed in the aperture synthesis signal processing. For this reason, the place where the defect 6 actually exists is different from the place where the amplitude of the reproduced image obtained by the aperture synthesis process is large. Specifically, since the received echoes 16A, 16B, and 16C are echoes as if they were reflected at the corners as shown in FIG. growing. FIG. 9 shows such a reproduced image.
[0058]
  Note that the path opposite to the propagation path shown in FIG. 6, that is, the ultrasonic pulse excited by the probe 7 is directly applied to the scratch 6, reflected by the scratch 6, and then reflected by the bottom surface 4. There are also paths that are received. A reproduced image obtained by performing aperture synthesis signal processing on the echo received through this path is the same as the reproduced image shown in FIG.
[0059]
  Next, the case where the ultrasonic pulse excited by the probe 7 is reflected on the bottom surface 4 after being reflected on the bottom surface 4, reflected on the scratch 6, and then reflected on the bottom surface 4 and received again. Description will be made with reference to FIGS. FIG. 10 shows an oblique flaw detection method in which an ultrasonic pulse excited by the probe 7 is reflected on the bottom surface 4 and then applied to the flaw 6, reflected on the flaw 6, and then reflected on the bottom surface 4 again. It is the figure which showed the propagation path of the echo which is received. In the figure, reference numerals 20A, 20B and 20C denote propagation paths of echoes received at the probe positions.
[0060]
  FIG. 11 shows echo waveforms received after being propagated along the propagation paths 20A, 20B and 20C. In the figure, 21A, 21B, and 21C are echoes that are excited and received at the probe positions 7A, 7B, and 7C.
[0061]
  FIG. 12 shows the state of aperture synthesis signal processing performed by the signal processing unit 84 using echoes propagated along the propagation paths 20A, 20B and 20C and received. In the figure, 22A, 22B and 22C are lengths corresponding to the beam path lengths of the echoes 21A, 21B and 21C. 23A, 23B, and 23C are circular arcs having 22A, 22B, and 22C as radii and 7A, 7B, and 7C as centers.
[0062]
  13 assumes that the received echoes 21A, 21B, and 21C are received along the propagation path as shown in FIG. 2, that is, directly irradiates the defect 6 and is reflected by the defect 6. It is a reconstructed image obtained when aperture synthetic signal processing is performed assuming a propagation path that is directly received. In the figure, 24 is a portion where the amplitude of the reproduced image is large.
[0063]
  In the aperture synthetic signal processing shown in FIG. 12, the ultrasonic pulse excited by the probe 7 is reflected on the bottom surface 4 and then irradiated on the scratch 6, reflected on the scratch 6, and then reflected on the bottom surface 4 again. The received echo is directly applied to the scratch 6, reflected by the scratch 6, and then processed along with the assumption that it is received along the directly received propagation path (propagation path shown in FIG. 2). Show. That is, the propagation path actually followed by the echo is different from the propagation path assumed in the aperture synthesis signal processing. For this reason, the place where the defect 6 actually exists is different from the place where the amplitude of the reproduced image obtained by the aperture synthesis process is large. Specifically, since the received echoes 21A, 21B, and 21C are reflected and received by the bottom surface 4 as shown in FIG. 10, the positions symmetrical to the position where the flaw 6 exists with the bottom surface 4 as the axis of symmetry. In the vicinity, the amplitude of the reproduced image increases. FIG. 13 shows such a reproduced image.
[0064]
  As described above, when the flaw 6 is near the bottom surface 4 of the test body 1, the reproduced image obtained by performing aperture synthesis on the received echo is:
(I) Near the position where scratch 6 exists
(Ii) The vicinity where the perpendicular drawn from the scratch 6 intersects the bottom surface 4
(Iii) Near the position symmetrical to the position where the flaw 6 exists with the bottom surface 4 as the axis of symmetry
There is a possibility that the amplitude of the three locations will increase. This phenomenon is greatly different between the case where the flaw 6 is spherical or a cylindrical shape having an axis in the direction along the paper surface and the case where the flaw 6 is a surface shape which is uniform in the direction along the paper surface. Hereinafter, spherical flaws and cylindrical flaws are referred to as “omnidirectional flaws”, and planar flaws are referred to as “directional flaws”. With non-directional flaws and directional flaws, reproduction obtained by aperture synthesis signal processing Explain that the images are very different.
[0065]
  There are various kinds of specimens 1 that reflect ultrasonic waves, and these are referred to as acoustic discontinuities. Here, all the acoustic discontinuities are represented by the word “flaw”. To do.
[0066]
  14 to 16 show the incidence and reflection of ultrasonic pulses when there is an omnidirectional flaw near the bottom surface 4. 14 to 16, reference numeral 25 denotes an omnidirectional flaw, reference numeral 26 denotes a propagation path of an ultrasonic pulse directly incident on the omnidirectional flaw 25, and reference numeral 27 denotes an echo propagation received after being reflected by the omnidirectional flaw. A path 28 is an echo propagation path that is reflected by the bottom surface 4 after being reflected by the omnidirectional scratch 25, and 29 is an ultrasonic pulse incident on the omnidirectional scratch 25 after being reflected by the bottom surface 4. It is a propagation path.
[0067]
  As shown in FIG. 14, the ultrasonic pulse incident on the omnidirectional flaw 25 is reflected by the omnidirectional flaw 25, then propagates in the direction of the probe 7, and there is an echo received directly. Further, the ultrasonic pulse reflected by the omnidirectional flaw 25 has a component that propagates in the direction of the bottom surface 4 after being reflected by the omnidirectional flaw 25. For this reason, as shown in FIG. 15, there is also an echo that is incident on the omnidirectional flaw 25, reflected by the omnidirectional flaw 25, and then reflected and received by the bottom surface 4. In addition, there is an echo that is reflected on the bottom surface 4 and then enters the omnidirectional defect 25, is reflected by the omnidirectional defect 25, propagates in the direction of the probe 7, and is received directly through this reverse path. Since the beam path length is the same, the description is omitted.
[0068]
  Further, as shown in FIG. 16, there is an echo that is reflected by the bottom surface 4 and then enters the omnidirectional defect 25, is reflected by the omnidirectional defect 25, and then is reflected and received again by the bottom surface 4. Therefore, when the omnidirectional flaw 25 is near the bottom surface 4, there are echoes that are propagated and received along the three paths shown in FIGS. 2, 6, and 10. For this reason, as shown in FIG. 17, the received echoes are three.
[0069]
  Since there are echoes that are received along the three paths, assuming that these echoes are propagated along the propagation path as shown in FIG. As shown in FIG. That is,
(I) Near the position where the omnidirectional flaw 25 exists
(Ii) The vicinity where the perpendicular line drawn from the non-directional flaw 25 intersects the bottom surface 4
(Iii) Near the position symmetrical to the position where the non-directional flaw 25 exists with the bottom surface 4 as the axis of symmetry
  As described above, the amplitudes at the three positions increase.
[0070]
  On the other hand, when the echo reflected by the directional flaw is subjected to aperture synthesis signal processing, an image is reproduced at a position different from the case of the omnidirectional flaw. For this reason,
・ Directivity flaw perpendicular to the bottom surface 4
・ Directivity flaw inclined in the opposite direction to the probe
・ Directional flaw inclined to the probe side
The above three cases will be described separately.
[0071]
  First, the case of a directivity flaw perpendicular to the bottom surface 4 will be described. FIG. 19 shows a state in which an ultrasonic pulse is incident on and reflected from a directivity flaw perpendicular to the bottom surface 4. In the figure, 30 is a directivity flaw perpendicular to the bottom surface 4, 31 is a propagation path of an ultrasonic pulse directly incident on the directivity flaw 30 perpendicular to the bottom surface 4, and 32 is a bottom surface 4. This is a propagation path of echoes that are reflected by the bottom surface 4 and received after being reflected by the vertical directivity flaw 30.
[0072]
  As shown in FIG. 19, when an ultrasonic pulse incident on a directivity flaw 30 perpendicular to the bottom surface 4 is reflected, many components of the reflected wave propagate in the bottom surface 4 direction. That is, the reflected wave propagates with directivity. On the other hand, the component propagating in the direction of the probe 7 is small. If this small component is ignored, the echo from the directivity flaw 30 perpendicular to the bottom surface 4 is only the echo received along the propagation path shown in FIG. 6, as shown in FIG. Therefore, when these echoes are subjected to aperture synthesis signal processing, a reproduced image is as shown in FIG. That is,
(Ii) In the vicinity where the perpendicular line drawn from the directivity flaw 30 perpendicular to the bottom surface 4 intersects the bottom surface 4
The amplitude of becomes larger.
[0073]
  Next, the case of a directivity flaw inclined to the opposite side to the probe will be described. FIG. 22 shows a state in which an ultrasonic pulse is incident on and reflected from a directivity flaw inclined to the side opposite to the probe 7 (hereinafter referred to as “+” side). In the figure, 33 is a directivity flaw inclined to the + side, 34 is a propagation path of an ultrasonic pulse incident on the directivity flaw 33 inclined to the + side, and 35 is reflected by the directivity flaw 33 inclined to the + side. Then, the propagation path of the echo received directly.
[0074]
  As shown in FIG. 22, when the ultrasonic pulse incident on the directivity flaw 33 inclined to the + side is reflected, many components of the reflected wave propagate in the direction of the probe 7. That is, the reflected wave propagates with directivity. On the other hand, the component propagating in the direction of the bottom surface 4 is small. If this small component is ignored, the echo from the directivity flaw 33 inclined to the + side is only the echo received along the propagation path shown in FIG. 2, as shown in FIG. Therefore, when these echoes are subjected to aperture synthesis signal processing, the reproduced image is as shown in FIG. That is,
(I) Near the position where the directional flaw 33 inclined toward the + side exists
The amplitude of becomes larger.
[0075]
  Next, the case of a directivity flaw inclined toward the probe side will be described. FIG. 25 shows a state in which an ultrasonic pulse is incident and reflected on a directional flaw inclined toward the probe side (hereinafter referred to as “−” side). In the figure, 36 is a directivity flaw inclined to the-side, 37 is a propagation path of an ultrasonic pulse that is reflected by the bottom surface 4 and then enters the directional flaw 36 inclined to the-side, and 38 is a-side. This is a propagation path of an echo that is reflected by an inclined directivity flaw 36 and then reflected and received by the bottom surface 4.
[0076]
  As shown in FIG. 25, when the ultrasonic pulse incident on the directivity flaw 36 inclined to the negative side is reflected, many components of the reflected wave propagate in the direction of the bottom surface 4. That is, the reflected wave propagates with directivity. On the other hand, the component propagating in the direction of the probe 7 is small. If this small component is ignored, the echo from the directivity flaw 36 inclined to the negative side is only the echo received along the propagation path shown in FIG. 10, as shown in FIG. Therefore, when these echoes are subjected to aperture synthesis signal processing, a reproduced image is as shown in FIG. That is,
(Iii) The amplitude near the position symmetrical to the position where the directivity flaw 36 inclined toward the negative side with respect to the bottom surface 4 is increased.
[0077]
  The above-described phenomenon is summarized as shown in FIG. FIG. 28 summarizes the locations where the amplitude of the reconstructed image obtained by the aperture synthetic signal processing increases for each type of flaw. In the figure, a circle mark means that the amplitude of the reproduced image is increased, and a-mark means that the amplitude of the reproduced image is decreased. As can be seen from the figure, the position at which the amplitude of the reproduced image obtained by aperture synthetic signal processing increases and the number at which the amplitude increases differ between non-directional flaws and directional flaws. If this phenomenon is used, it is possible to classify omnidirectional flaws and directional flaws.
[0078]
  In fact, an experiment was conducted to determine whether or not flaw classification as shown in FIG. 28 was possible. A steel specimen with a φ2mm horizontal hole imitating an omnidirectional flaw at a position of 5 mm from the bottom surface, and a steel specimen having a vertical slit imitating a directional flaw and a 15 ° inclined slit at a position of 5 mm from the bottom surface. Then, an ultrasonic flaw detection test was performed and the echoes were stored in the memory. Aperture synthesis signal processing was performed using this data. The obtained reproduced images are shown in FIGS. 29, 30, 31, and 32 are a φ2 mm horizontal hole, a 5 mm high vertical slit, a 5 mm high slit inclined 15 ° in the positive direction, and a 5 mm high slit inclined 15 ° in the negative direction. This is a reproduced image obtained as a result of aperture synthesis signal processing using echoes from the. 29 to 32, 39 is a horizontal hole having a diameter of 2 mm, 40 is a vertical slit having a height of 5 mm, 41 is a slit having a height of 15 mm inclined by 15 ° in the positive direction, and 42 is a height inclined by 15 ° in the negative direction. It is a 5 mm slit.
[0079]
  As can be seen from FIG. 29, an image obtained by performing aperture synthetic signal processing using an echo from a side hole 39 having a diameter of 2 mm is
(I) Near the position where there is a flaw
(Ii) Near bottom 4
(Iii) Near the position where the bottom surface 4 is symmetric with respect to the position where the flaw exists with the axis being symmetrical
Images appear in the above three places. This proves that the classification shown in FIG. 28 is correct.
[0080]
  As can be seen from FIG. 30, the image obtained by performing the aperture synthesis process using the echo from the vertical slit 40 is
(Ii) Near bottom 4
The image appears only in. This proves that the classification shown in FIG. 28 is correct.
[0081]
  As can be seen from FIG. 31, the image obtained by performing the aperture synthesis process using the echo from the slit 41 inclined in the + direction is
(I) Near the position where there is a flaw
The image appears only in. This proves that the classification shown in FIG. 28 is correct.
[0082]
  As can be seen from FIG. 32, the image obtained by performing the aperture synthesis process using the echo from the slit 42 inclined in the − direction is
(Iii) Near the position where the bottom surface 4 is symmetric with respect to the position where the flaw exists with the axis being symmetrical
The image appears only in. This proves that the classification shown in FIG. 28 is correct.
[0083]
  As described above, when the flaw 6 is near the bottom surface of the specimen 2, the reproduced image obtained by aperture synthesis processing of the echo from the flaw 6 shows different characteristics depending on the kind of the flaw. By utilizing this fact, it becomes possible to classify omnidirectional flaws and directional flaws.
[0084]
  So far, it has been described that omnidirectional flaws and directional flaws can be classified from reproduced images obtained by aperture synthetic signal processing in the oblique flaw detection method. Hereinafter, a signal processing method for specific classification in the signal processing unit 84 will be described with reference to the flowchart shown in FIG. 33 and FIGS. 34 to 40. Note that the flowchart in FIG. 33 illustrates processing after the spatial position of the probe 7 and the received echo are stored in the memory in the signal processing unit 84.
[0085]
  First, as Step 1, an image reproduction range for performing aperture synthesis signal processing is determined. This image reproduction range is determined to include not only the inside of the test body 1 but also the area outside the test body 1 with the bottom surface 4 interposed therebetween. Further, the width of the image reproduction range is appropriately changed according to the test body 1, the probe 7, and the like.
[0086]
  Next, as Step 2, aperture synthetic signal processing is performed using the flaw detection test data stored in the memory in the signal processing unit 84, that is, the spatial position of the probe 7 and the received echo. The aperture synthetic signal processing is performed by a method that is assumed to include no reflection on the bottom surface 4 of the specimen 1 among the methods described in International Publication No. W097 / 36175. Note that the method described in International Publication No. W097 / 36175 uses the center of the apparent vibrator as the phase origin, but here, the time origin is not the center of the apparent vibrator. -The method described in -238444. That is, the time origin is the center of the actual vibrator.
[0087]
  As Step 3, the maximum value of the amplitude of the reproduced image and the position indicating the maximum value are obtained in the image reproduction range determined in Step 1. Thereafter, the maximum value of the reproduced image is set to P₀ I will call it. Moreover, the state up to Step 3 is shown in FIG. In FIG. 34, 43 is an image reproduction range, and 44 is a position indicating the maximum value of the amplitude of the reproduction image.
[0088]
  As Step 4, an area is specified with a predetermined width around the position indicating the maximum value of the image. For example, the predetermined width is determined as “± 3λ (λ is a wavelength in the test body 1) in the horizontal direction from the position showing the maximum value”. This width is appropriately changed depending on the specimen 1 or the probe 7. Further, the specified area is referred to as a specific area. The state of Step 4 is shown in FIG. In FIG. 35, 45 is a specific area.
[0089]
  As Step 5, in the specific area 45, the amplitude of the reproduced image is compared with a predetermined threshold value, and when the amplitude of the reproduced image exceeds the threshold value, the location is obtained and stored. Further, when the amplitude is larger than the threshold value, the amplitude is referred to as “flaw amplitude” herein. The threshold value is, for example, “P₀ -6 dB "in comparison with. This threshold value is appropriately changed depending on the specimen 1 and the probe 7.
[0090]
  In Step 6, the number of flaw amplitudes obtained in Step 5 is counted, and it is determined whether or not it is four or more. If the flaw amplitude is 4 or more, proceed to Step 7. If the flaw amplitude is not 4 or more (3 or less), the process proceeds to Step 8. First, Step 7 will be described.
[0091]
  With the classification method shown in FIG. 28, classification is possible when the number of flaw amplitudes is three or less, but classification is not possible when there are four or more flaw amplitudes. Therefore, when the flaw amplitude becomes four or more, the threshold value is increased as Step 7 in order to reduce the number of flaw amplitudes. For example, if the threshold is “P₀ When the number of flaw amplitudes is 4 or more as compared to -6 dB ", the threshold is set to" P₀ -3 dB "compared to After Step 7, the process proceeds to Step 5.
[0092]
  In Step 8, it is determined whether or not the number of flaw amplitudes obtained in Step 5 is three. If the flaw amplitude is 3, the process proceeds to Step 9. If the number is not three (two or less), the process proceeds to Step 12. First, Step 9 will be described.
[0093]
  As shown in FIG. 28, in the case of an omnidirectional flaw, the number of flaw amplitudes is three. However, when there are three planar flaws inclined to the + side or three planar flaws inclined to the − side, the number of flaw amplitudes is three. Therefore, omnidirectional flaws and directional flaws cannot be classified only by the number of flaw amplitudes. Therefore, the classification is performed using not only the number of flaw amplitudes but also the characteristics of the reproduced image. As shown in FIGS. 18 and 29, in the case of an omnidirectional flaw,
(I) Near the position where there is a flaw
(Ii) Near bottom 4
(Iii) Near the position where the bottom surface 4 is symmetric with respect to the position where the flaw exists with the axis being symmetrical
The amplitude of these three locations becomes large. That is, as shown in FIG. 36, the image is axisymmetric with respect to the bottom surface 4. Using this feature, when there are three flaw amplitudes, non-directional flaws and directional flaws are classified.
[0094]
  In Step 9, three flaw amplitude positions are detected, and the distances from the flaw detection surface 3 to these flaw amplitude positions are set to y1, y2, and y3 in ascending order as shown in FIG. 37, for example. The values of y1, y2 and y3 are
    | (Y1 + y3) / 2−y2 | <δ1 (1)
  And
    | Y2-t | <δ2 (2)
If the condition is satisfied, the process proceeds to Step 10, where it is determined that the defect is non-directional, and the defect classification process is terminated. Here, t is the thickness of the test body 1. Further, δ1 and δ2 are values determined in advance, and these are appropriately changed depending on the test body 1, the probe 7, and the like.
[0095]
  On the other hand, when Expression (1) and Expression (2) are not satisfied in Step 9, the process proceeds to Step 11, and is determined separately without being determined in the processing in the signal processing unit 85, and the process is terminated. As described above, when the number of flaw amplitudes is three and the expressions (1) and (2) are not satisfied, there are three directional flaws inclined to the + side, or A case where there are three inclined directivity flaws is conceivable. However, since it is rare that three directional flaws exist adjacent to each other in the test body 1, automatic discrimination is not performed in Step 11, and the discrimination is made individually.
[0096]
  When Step 8 cannot be performed and the number of amplitudes is not 3, the process proceeds to Step 12. In Step 12, it is determined whether or not the number of flaw amplitudes is two. If the number of flaw amplitudes is 2, the process proceeds to Step 13. If the number is not two, that is, the number is one, the process proceeds to Step 16. First, Step 16 will be described.
[0097]
  As shown in FIG. 28, in the case of directivity flaws, the number of flaw amplitudes is one. Therefore, in Step 16, it is determined that the defect is a directivity defect, and the defect classification process is terminated.
[0098]
  On the other hand, in Step 13, it is determined whether one of the two flaw amplitudes is near the bottom surface 4. The reason why the directivity flaw can be determined as a result will now be described.
[0099]
  30, 31, and 32 are images obtained when aperture echo signal processing is performed on echoes from directivity flaws, and the number of flaw amplitudes is one. However, when the inclination of the directivity flaw is gentle, for example, when it is inclined + 5 °, the echo propagated along the propagation path shown in FIG. 2 and the propagation shown in FIG. There may be both echoes received along the path. In this case, since two echoes are received at the angular probe position, even in a reproduced image obtained by aperture synthesis processing, as shown in FIG.
(I) Near the position where there is a flaw
(Ii) Near bottom 4
There are two flaw amplitudes, one for each. For example, in the case of tilting by −5 °, the echo received along the propagation path shown in FIG. 6 and the echo received after propagating along the propagation path shown in FIG. May exist together. Also in this case, since two echoes are received at each probe position, even in a reproduced image obtained by aperture synthetic signal processing, as shown in FIG.
(Ii) Near bottom 4
(Iii) Near the position where the bottom surface 4 is symmetric with respect to the position where the flaw exists with the axis being symmetrical
There are two flaw amplitudes, one for each. As described above, when the number of flaw amplitudes is two and one of the flaw amplitudes is near the bottom surface 4, it can be determined that the flaw is a directivity flaw. Therefore, not only when the number of flaw amplitudes is one, but also when there are two flaw amplitudes, if one of them is near the bottom surface 4, it can be determined that there is a directivity flaw.
[0100]
  In Step 13, the positions of two flaw amplitudes are detected. The distances from the flaw detection surface 3 to these positions are, for example, y1 and y2 in ascending order as shown in FIG. These y1 and y2 values are
    | Y1-t | <δ3 (3)
  Or
    | Y2-t | <δ3 (4)
If the condition is satisfied, the process proceeds to Step 14, where it is determined that the defect is a directivity defect and the defect classification process is terminated. Here, δ3 is a value determined in advance, and these are appropriately changed depending on the specimen 1, the probe 7, and the like.
[0101]
  In Step 13, when Expressions (3) and (4) are not satisfied, the process proceeds to Step 15, where the signal processing unit 85 does not determine, but separately determines and ends the defect classification process. Since there are two flaw amplitudes, and none of them is near the bottom surface 4, it is considered rare. Therefore, in Step 15, automatic discrimination is not performed, but individual discrimination is performed.
[0102]
  The processing for classifying flaws from the characteristics of the reproduced image of the image obtained by the aperture synthetic signal processing has been described above. However, the characteristics of the reproduced image obtained by the B scope are also based on the flowchart shown in FIG. Flaws can be classified by processing. The reason for this will be described next.
[0103]
  The difference between the aperture synthesis signal processing and the B scope is the difference between whether or not data is added. Therefore, when aperture synthesis signal processing is performed assuming that the spread of the ultrasonic beam is very small, the data is added. As a result, a reproduced image almost the same as the reproduced image obtained by the B scope is obtained. That is, the reproduced image obtained by the aperture synthetic signal processing and the reproduced image obtained by the B scope have substantially the same characteristics.
[0104]
  Therefore, even if Step 3 and the subsequent steps of the defect classification flowchart shown in FIG. 33 are applied as they are using the reproduced image obtained by the B scope, the same as the case where the reproduced image obtained by the aperture synthetic signal processing is used. A processing result is obtained.
[0105]
  Japanese Patent Application Laid-Open No. 10-142201 discloses a display method called a correction B scope. In this display method, the time axis in the B scope is corrected and displayed for each spatial position of the probe. The image obtained by the correction B scope has substantially the same characteristics as the reproduced image obtained by the aperture synthetic signal processing and the reproduced image obtained by the B scope.
  Therefore, even if Step 3 and subsequent steps in the defect classification flowchart shown in FIG. 33 are applied as they are using the reproduced image obtained by the corrected B scope, the reproduced image obtained by the aperture synthetic signal processing and the B scope are obtained. A processing result similar to that obtained when the reproduced image is used is obtained.
[0106]
  Note that the flaw classification process described above can classify flaws only by using data flaw-detected from either the left or right direction with respect to the location where the flaw 6 exists. For example, when flaw detection is performed on a welded part and only one side can be flawed due to the shape of the specimen and the surrounding environment, the omni-directional flaw and directivity can be obtained by performing the above flaw classification process. Can classify flaws.
[0107]
  Furthermore, the processing for flaw classification described above has been described for the case where flaws 6 near the bottom surface 4 are flaw detected with 0.5 skip, but when there are flaws 6 near the flaw detection surface 3 The flaws can be classified by performing flaw detection with 1.0 skip and performing the above-described processing for flaw classification.
[0108]
  As described above, it is possible to classify omnidirectional flaws and directional flaws from the reproduced image obtained by using the spatial position of the probe and the received echo only by scanning the probe back and forth. As a result, it is possible to reduce the time and cost as compared with the prior art.
[0109]
  In the present invention, an ultrasonic probe that transmits an ultrasonic pulse to an acoustic discontinuity as a sensor and receives an echo corresponding to the ultrasonic pulse reflected from the acoustic discontinuity is used. The sensor is not limited to an ultrasonic probe, and may be any sensor that can transmit a pulse to an acoustic discontinuity and receive an echo with respect to the pulse reflected from the acoustic discontinuity.
[0110]
【The invention's effect】
  According to the first invention, driven by the transmission signal, the pulse is transmitted obliquely with respect to the surface of the measured object, and the echo for the pulse reflected by the acoustic discontinuity in the measured object is received. A sensor that scans the sensor over the object to be measured and outputs a spatial position of the sensor, and an acoustic signal based on an echo received by the sensor and a spatial position of the sensor. Generate an image of the discontinuity and the generated imageWhen the number of objects exhibiting an amplitude exceeding a predetermined threshold is 3 and satisfies the condition of being an omnidirectional acoustic discontinuity within the specific range in FIG. Is identified as an acoustic discontinuityIt is characterized by having signal processing means, so in a shorter time and lower cost than conventionalCan be identified as omnidirectional acoustic discontinuitiesThere is an effect that can be done.
[0111]
  Also,Second inventionAccording to the above, the condition of the omnidirectional acoustic discontinuity is that the positional relationship of those exceeding the three thresholds is substantially equidistant, and is intermediate between those exceeding the three thresholds. Since there is a condition that a certain position exists near the bottom surface of the object to be measured, the same effect as described above can be obtained.
[0112]
  According to the third invention,A sensor driven by a transmission signal, transmitting a pulse obliquely to the surface of the object to be measured, and receiving an echo for the pulse reflected by an acoustic discontinuity in the object to be measured; and An image of the acoustic discontinuity is generated on the basis of scanning means for scanning the object to be measured and outputting the spatial position of the sensor, echoes received by the sensor, and the spatial position of the sensor. When the number of objects exhibiting an amplitude exceeding a predetermined threshold is two within a specific range in the generated image and the condition of being a directional acoustic discontinuity is satisfied Since the signal processing means for determining that the directional acoustic discontinuity is provided, the directional acoustic discontinuity can be obtained in a shorter time and at a lower cost than in the past. Can be determined ThatThere is an effect.
[0113]
  Also,4th inventionAccording to the above, the condition that the acoustic discontinuity of the directivity is a condition that one of the two exceeding the two thresholds is present near the bottom surface of the object to be measured. Since this is a characteristic, the same effect as described above is obtained.
[0114]
  According to the fifth inventionSince the image is an image obtained by aperture synthetic signal processing, the same effect as described above can be obtained.
[0115]
  Also,According to the sixth inventionSince the image is an image obtained by B-scope display, the same effect as described above can be obtained.
[0116]
  According to the seventh inventionA transmission step of generating a transmission signal and outputting to the sensor, and propagating the pulse through the measured object by the sensor; and echoing the pulse reflected by an acoustic discontinuity in the measured object by the sensor Receiving step, moving step for moving the sensor to a predetermined location, inputting and storing the received echo, and inputting a spatial position of the sensor when the echo is received A storing step for storing, and the echo and the echo when the echo is receivedSensorWith spatial positionAcoustic discontinuityStatueGenerationAnd the statueIn the specific range in Fig. 3, the number of objects exhibiting an amplitude exceeding a predetermined threshold is three, and the condition of being an omnidirectional acoustic discontinuity is satisfied. When adding, it is determined that the omnidirectional acoustic discontinuity is presentSignal processing step, and in a shorter time and at a lower cost than conventional methods.Can be identified as omnidirectional acoustic discontinuitiesThere is an effect that can be done.
[0117]
  Also,Eighth inventionAccording to the above, the condition of the omnidirectional acoustic discontinuity is that the positional relationship of those exceeding the three thresholds is substantially equidistant, and is intermediate between those exceeding the three thresholds. Since there is a condition that a certain position exists near the bottom surface of the object to be measured, the same effect as described above can be obtained.
[0118]
  According to the ninth invention, a transmission step of generating a transmission signal and outputting it to a sensor and propagating a pulse in the measured object by the sensor, and an acoustic discontinuity in the measured object by the sensor A receiving step of receiving the reflected pulse as an echo, a moving step of moving the sensor to a predetermined location, and inputting and storing the received echo, and the sensor at the time of receiving the echo A storage step of inputting and storing a spatial position, and generating an image of an acoustic discontinuity using the echo and the spatial position of the sensor when the echo is received, and within a specific range in the image If the number of objects exhibiting an amplitude exceeding a predetermined threshold is 2 and the condition of being an acoustic discontinuity of directivity is satisfied, the directivity sound Because characterized in that it comprises a signal processing step of determining that the discontinuities, be judged in a short time and low cost compared to conventional an acoustic discontinuous portion of the directionalThere is an effect that can be done.
[0119]
  Also,10th inventionAccording to the above, the condition that the acoustic discontinuity of the directivity is a condition that one of the two exceeding the two thresholds is present near the bottom surface of the object to be measured. Since this is a characteristic, the same effect as described above is obtained.
[0120]
  Eleventh inventionAccording to the above, since the image is an image obtained by aperture synthesis signal processing, the same effect as described above can be obtained.
[0121]
  Also,12th inventionAccording to the above, since the image is an image obtained by B scope display, the same effect as described above can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 1 of the present invention.
FIG. 2 is a diagram showing an operation according to Embodiment 1 of the present invention.
FIG. 3 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 4 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 5 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 6 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 7 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 8 shows an operation according to the first embodiment of the present invention.
FIG. 9 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 10 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 11 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 12 shows an operation according to the first embodiment of the present invention.
FIG. 13 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 14 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 15 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 16 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 17 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 18 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 19 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 20 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 21 shows an operation according to the first embodiment of the present invention.
FIG. 22 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 23 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 24 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 25 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 26 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 27 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 28 is a view for explaining flaw classification according to Embodiment 1 of the present invention;
FIG. 29 is an experimental result showing an operation according to the first embodiment of the present invention.
FIG. 30 is an experimental result showing the operation according to the first embodiment of the present invention.
FIG. 31 is an experimental result showing the operation according to Embodiment 1 of the present invention;
FIG. 32 is an experimental result showing the operation according to Embodiment 1 of the present invention;
FIG. 33 is a flowchart showing an operation according to the first embodiment of the present invention.
FIG. 34 is a diagram showing operations according to Embodiment 1 of the present invention.
FIG. 35 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 36 shows an operation according to the first embodiment of the present invention.
FIG. 37 shows an operation according to the first embodiment of the present invention.
FIG. 38 shows an operation according to the first embodiment of the present invention.
FIG. 39 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 40 is a diagram showing an operation according to the first embodiment of the present invention.
FIG. 41 is a diagram showing a configuration of a conventional ultrasonic flaw detector.
FIG. 42 is a diagram showing the operation of a conventional ultrasonic flaw detector.
FIG. 43 is a diagram showing the operation of a conventional ultrasonic flaw detector.
FIG. 44 is a diagram showing the operation of a conventional ultrasonic flaw detector.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 1 Test body, 3 Flaw detection surface, 4 Bottom surface of test body, 6 Scratch, 7 Probe, 8 Transmission / reception apparatus, 9 Scanning mechanism part, 71 Vibrator, 72 Wedge, 74 Welding part, 81 Control part, 82 Transmission part, 83 receiver, 84 signal processor, 85 position detector.

Claims (12)

A sensor driven by a transmission signal, transmitting a pulse obliquely to the surface of the object to be measured, and receiving an echo for the pulse reflected by an acoustic discontinuity in the object to be measured; and An image of the acoustic discontinuity is generated on the basis of scanning means for scanning the object to be measured and outputting the spatial position of the sensor, echoes received by the sensor, and the spatial position of the sensor. When the number of objects exhibiting an amplitude exceeding a predetermined threshold is 3 within a specific range in the generated image and the condition of non-directional acoustic discontinuity is satisfied Comprises a signal processing means for determining that the omnidirectional acoustic discontinuity is present . The condition of the non-directional acoustic discontinuity is that the positional relationship of those exceeding the three thresholds is substantially equidistant, and the position of the intermediate one of those exceeding the three thresholds is 2. The property determination device for an acoustic discontinuity according to claim 1 , wherein the condition is in the vicinity of a bottom surface of the object to be measured. A sensor driven by a transmission signal, transmitting a pulse obliquely to the surface of the object to be measured, and receiving an echo for the pulse reflected by an acoustic discontinuity in the object to be measured; and An image of the acoustic discontinuity is generated on the basis of scanning means for scanning the object to be measured and outputting the spatial position of the sensor, echoes received by the sensor, and the spatial position of the sensor. When the number of objects exhibiting an amplitude exceeding a predetermined threshold is two within a specific range in the generated image and the condition of being a directional acoustic discontinuity is satisfied And an acoustic discontinuity property determining apparatus , comprising: signal processing means for determining that the acoustic discontinuity has directivity . Conditions that are acoustically discontinuous portion of the directivity, wherein said among those beyond the two threshold, either one, wherein the a condition that exists on the bottom vicinity of the object to be measured Item 3. An apparatus for determining properties of acoustic discontinuities according to Item 3 . The property of the acoustic discontinuity according to any one of claims 1 to 4, wherein the signal processing means generates an image of the acoustic discontinuity by aperture synthetic signal processing. Judgment device. The property of the acoustic discontinuity according to any one of claims 1 to 4, wherein the signal processing means generates an image of the acoustic discontinuity by cross-sectional display signal processing. Judgment device. A transmission step of generating a transmission signal and outputting it to a sensor, and propagating a pulse through the measured object by the sensor;
A receiving step of receiving, as an echo, the pulse reflected by the acoustic discontinuity of the object to be measured by the sensor;
A moving step of moving the previous SL sensors in place,
A step of inputting and storing the received echo, and a step of inputting and storing a spatial position of the sensor when the echo is received;
An image of the acoustic discontinuity is generated using the echo and a spatial position of the sensor when the echo is received , and is predetermined within a specific range in the image of the acoustic discontinuity . When the number of objects exhibiting an amplitude exceeding the threshold is 3 and the condition of being an omnidirectional acoustic discontinuity is satisfied, it is determined that the omnidirectional acoustic discontinuity is present. A signal processing step;
A method for determining the properties of acoustic discontinuities, comprising: The condition of the non-directional acoustic discontinuity is that the positional relationship of those exceeding the three thresholds is substantially equidistant, and the position of the intermediate one of those exceeding the three thresholds is 8. The property determination method for an acoustic discontinuity according to claim 7 , wherein the condition is that the measurement object exists near the bottom surface of the object to be measured. Generating a transmission signal and outputs to the sensor, a transmission step of propagating in the measuring Teikarada a pulse by the sensor,
A reception step of receiving, as an echo, the pulse reflected by the acoustic discontinuity of the measurement object by the sensor;
A moving step of moving the sensor to a predetermined location;
A step of inputting and storing the received echo, and a step of inputting and storing a spatial position of the sensor when the echo is received;
An image of the acoustic discontinuity is generated using the echo and a spatial position of the sensor when the echo is received, and is predetermined within a specific range in the image of the acoustic discontinuity. When the number of objects exhibiting an amplitude exceeding the threshold is two and the condition of being a directional acoustic discontinuity is satisfied, signal processing for determining that the directional acoustic discontinuity is present Steps,
A method for determining the properties of acoustic discontinuities , comprising : Conditions that are acoustically discontinuous portion of the directivity, wherein said among those beyond the two threshold, either one, wherein the a condition that exists on the bottom vicinity of the object to be measured Item 10. The method for determining the properties of acoustic discontinuities according to Item 9 . 11. The acoustic discontinuity portion according to claim 7 , wherein the signal processing step generates an image of the acoustic discontinuity portion by aperture synthesis signal processing. 11 . A property determination method. 11. The acoustic discontinuity portion according to claim 7 , wherein the signal processing step generates an image of the acoustic discontinuity portion by cross-section display signal processing. A property determination method.

Images