JP5233211B2 - Ultrasonic flaw detection apparatus and ultrasonic flaw detection method - Google Patents

Description

  The present invention relates to an ultrasonic flaw detector, a sensitivity correction method for an ultrasonic flaw detector, and an ultrasonic flaw detection method, and particularly preferably, the surface and internal state of a material to be measured (a flaw detection material) such as a steel material. The present invention relates to an ultrasonic flaw detector that uses ultrasonic waves to measure a material to be measured without destroying it, a sensitivity correction method for the ultrasonic flaw detector, and an ultrasonic flaw detector method.

  As a device and a method for measuring a state of a material to be measured such as a steel material, for example, a surface flaw or an internal flaw, an ultrasonic flaw detector and an ultrasonic flaw detection method are widely used. A typical ultrasonic flaw detector has a single or multiple probes, and propagates the ultrasonic waves generated by the ultrasonic transducer of the probe into the material to be measured and detects the echoes (echoes). Thus, an abnormal discontinuity existing on the surface or inside of the material to be measured, that is, “a flaw (surface flaw and / or internal flaw)” is measured.

  In order to measure “scratches” in a material to be measured using an ultrasonic flaw detector and an ultrasonic flaw detection method, and to determine whether the measured “flaws” are “defects”, the measurement sensitivity is set to It is necessary to set the optimum value and perform highly accurate measurement. For this reason, a method of adjusting measurement sensitivity using the bottom echo of the sound part of the material to be measured (sensitivity adjustment method of the bottom echo method) or a method of adjusting measurement sensitivity using a sensitivity standard test piece or a contrast test piece ( Test piece type sensitivity adjustment method) is performed.

  By the way, for example, when measuring a long material to be measured, a method of obtaining an echo by scanning the probe relatively in the longitudinal direction of the material to be measured may be used. At this time, if the material to be measured is deformed (for example, if the longitudinal axis is not a straight line), when the probe is scanned, the positional relationship between the probe and the material to be measured is measured. It may change depending on the position of the material. Then, when an echo is obtained, the incident angle of the ultrasonic beam, the beam path, and the angle of the measurement target part may vary depending on the position of the measured material, and the obtained echo may be nonuniform depending on the position of the measured material. . If the obtained echo is non-uniform, the measurement accuracy may be reduced.

  In order to measure the surface state and internal state of a material to be measured with higher accuracy, various sensitivity adjustment methods and sensitivity correction methods, and an ultrasonic flaw detector and an ultrasonic flaw detection method using them have been proposed. For example, the following configuration has been proposed.

  Japanese Patent Application Laid-Open No. 2004-228561 has a configuration in which the echo height is made constant (that is, sensitivity is made constant) by correcting the received signal of the ultrasonic beam in the sector scanning type ultrasonic flaw detection apparatus and ultrasonic flaw detection method. It is disclosed. Specifically, the sensitivity of the received signal is (1) the difference in the deflection angle of the ultrasonic beam due to the difference in the directivity of the probe, and (2) the medium that acoustically couples the probe and the material to be inspected. And (3) attenuation of the ultrasonic beam inside the inspection object and the medium, and (4) difference in beam width at the focal point of the ultrasonic beam. . Therefore, the correction value of the sensitivity change caused by each is calculated and stored by a predetermined mathematical formula, and the sensitivity is corrected based on the stored correction value.

  Further, in Patent Document 2, in a linear scanning ultrasonic diagnostic apparatus, a predetermined signal is added to an echo whose amplitude has changed, thereby canceling the change in the echo and obtaining an echo having a constant amplitude (corrected echo signal). A configuration is disclosed. Specifically, the ultrasonic diagnostic apparatus includes a sensitivity corrector in the depth direction (presumed to be the traveling direction of the ultrasonic beam) and a sensitivity corrector in the azimuth direction (possibly perpendicular to the traveling direction of the ultrasonic beam). With. The azimuth direction sensitivity corrector further includes a plurality of variable resistors and a changeover switch. Then, the signal from each of the resistors is added to the echo reflected from the material to be measured and changed in amplitude in the azimuth direction via the changeover switch. As a result, the echo change is canceled and an echo having a constant amplitude is obtained.

  Thus, an ultrasonic flaw detector using an array probe obtains an echo by propagating an ultrasonic beam to one or more preset focal positions. The conventional sensitivity correction in such an ultrasonic flaw detection apparatus or ultrasonic flaw detection method is to correct changes in sensitivity due to the incident angle of the ultrasonic beam, the beam path length, and the angle of the measurement target part when obtaining an echo. Done.

  By the way, in order to carry out ultrasonic flaw detection with high accuracy, it is preferable to always maintain the positional relationship between the probe and the material to be measured in the correct positional relationship. However, any of the above-described configurations corrects the obtained echo and does not consider performing ultrasonic flaw detection while correcting the positional relationship between the probe and the material to be measured.

Japanese Patent Laid-Open No. 11-183446 Japanese Patent Laid-Open No. 2-246554

  In view of the above situation, the problem to be solved by the present invention is that the measurement sensitivity of the measurement target range becomes substantially constant when the surface flaw and / or the internal flaw of the material to be measured is measured using a probe. An ultrasonic flaw detector or an ultrasonic flaw detection method, for example, when scanning a probe, an ultrasonic flaw detector capable of measuring while maintaining a substantially uniform positional relationship between a material to be measured and the probe or It is to provide an ultrasonic flaw detection method.

To solve the above problems, the present invention includes a sequence type probe having an ultrasonic transducer capable of receiving ultrasonic echoes irradiated with ultrasonic waves to be measured material, the array type probe and the measured material a plurality of pre-Symbol ultrasonic echo waveform obtained by transmission and reception of ultrasonic waves for performing a driving means capable of changing the relative position and / or relative angle position correction of the sequence type probe and, First storage means capable of storing the positional relationship between the array probe and the material to be measured at the time of reception of the waveform of the ultrasonic echo, and the relative movement between the array probe and the material to be measured The second storage means that can store the waveform of the ultrasonic echo received at a predetermined X-axis direction position, the waveform stored in the second storage means, and the first storage means The waveform stored in the first storage means is compared with the waveform. It includes a matching means for selecting from a waveform second storage means for same or most similar to the waveform stored in the waveform, wherein the drive means, the sequence type probe corresponding to the waveform the matching means has selected on the basis of the positional relationship of the measured material and is moved to a measurement position where the surface echo height and horizontal distance obtained becomes substantially uniform the sequence type probe from a plurality of ultrasonic transducers, surveying position The main point is that flaw detection can be performed in

  The “correct measurement position” is a position where the surface echo height and water distance obtained from a plurality of ultrasonic transducers are substantially uniform. Physically, for example, when the cross-sectional shape of the material to be measured is substantially circular, it refers to a position where the material to be measured and a plurality of ultrasonic transducers arranged concentrically. In addition, when the cross-sectional shape of the material to be measured is a square, it refers to a position where the surface of the material to be measured that is irradiated with ultrasonic waves and the plurality of arranged ultrasonic transducers are parallel.

  Here, the first storage unit and the second storage unit can store a waveform including information on the position from the ultrasonic transducer to the measured material and the surface echo height, and the matching unit includes: One of the distance or surface echo height between the ultrasonic transducer having the waveform stored in the first storage means and the measured material, and the ultrasonic transducer having the waveform stored in the second storage means and the measured material Compare the same one with the same distance or surface echo height, and select a plurality of the ones approximated to the same one stored in the second storage unit from the plurality of ones stored in the first storage unit The other corresponding to the selected plurality of ones is compared with the same other stored in the second storage means, and the closest one is the same or the most approximate waveform It is preferable.

  Further, the probe includes a plurality of ultrasonic transducers, and the driving unit can rotate the probe in a yaw direction with respect to a direction of relative movement between the probe and the material to be measured. Is preferred.

  Further, the present invention is an ultrasonic flaw detection method using any one of the ultrasonic flaw detection apparatuses, wherein an ultrasonic echo waveform corresponding to the position of the probe and the material to be measured is stored in the first storage means. A step of storing, a step of irradiating the material to be measured with ultrasonic waves, a step of receiving ultrasonic echoes, a step of storing a waveform of the received ultrasonic echoes in the second storage means, and the first A step of selecting a waveform that is the same or most approximate to the waveform stored in the second storage means from waveforms corresponding to the position of the probe stored in the storage means; and the position of the selected probe And a step of correcting the position of the probe from a waveform according to the above and a step of performing ultrasonic flaw detection at the corrected position.

  Here, the step of storing the waveform of the ultrasonic echo according to the position of the probe and the material to be measured in the first storage means is to detect a correct measurement position and to detect a predetermined range including the detected correct measurement position It is preferable that it is a step of receiving ultrasonic echoes by irradiating the measurement object with ultrasonic waves at a plurality of locations, and accumulating the received ultrasonic echo waveforms in the first storage means.

  The step of selecting a waveform that is the same or most approximate to the waveform stored in the second storage means from the plurality of waveforms stored in the first storage means is the step of selecting the waveform stored in the first storage means. One of the distance between the ultrasonic transducer and the material to be measured or the surface echo height and the same one of the distance between the ultrasonic transducer and the material to be measured of the waveform stored in the second storage means or the surface echo height The plurality of ones stored in the first storage unit are selected from the plurality of the ones that approximate the same one stored in the second storage unit, and the selected one of the plurality of ones is selected. It is preferable that the corresponding other and the same other stored in the second storage means are compared, and the most approximated one is that the waveform is the same or the closest approximated.

  According to the present invention, the probe can be moved from the position of the probe corresponding to the waveform data selected by the matching means to the correct measurement position. Therefore, since ultrasonic flaw detection can always be performed at the correct measurement position, high-accuracy ultrasonic flaw detection can be performed.

  Here, one of the distance between the ultrasonic transducer having the waveform stored in the first storage means and the material to be measured or the surface echo height is first compared, and a plurality of approximations are selected, and then the selected one is selected. Therefore, if the configuration in which the other of the distance between the ultrasonic transducer and the measured material or the surface echo height is approximated is selected, the amount of calculation can be reduced. For this reason, highly accurate ultrasonic flaw detection can be performed while shortening the time required for calculating the position of the probe.

  Further, the probe includes a plurality of ultrasonic transducers, and the driving means can rotate the probe in the yaw direction with respect to the direction of relative movement of the probe and the material to be measured. The positional relationship between the plurality of ultrasonic transducers provided in the probe and the material to be measured can be made uniform. Therefore, highly accurate flaw detection can be performed.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is an external perspective view schematically showing the configuration of an ultrasonic flaw detector 1 according to an embodiment of the present invention. FIG. 2 is a block diagram schematically showing the configuration of the ultrasonic flaw detector 1 according to the embodiment of the present invention.

  As shown in FIG. 1, an ultrasonic flaw detector 1 according to an embodiment of the present invention includes an array-type probe 111, an X-axis scanning slider 112, a Y-axis scanning slider 113, a Z-axis scanning slider 114, A θx rotating jig 115, a θy rotating jig 116, a θz rotating jig 117, and a water tank 118 are provided.

  The array-type probe 111 includes a predetermined number of ultrasonic transducers (not shown) that can operate independently. Each ultrasonic transducer is an element capable of transmitting and receiving ultrasonic waves, and various known ultrasonic transducers such as quartz and ceramics can be applied. A specific arrangement form of the plurality of ultrasonic transducers will be described later.

  The X-axis scanning slider 112, the Y-axis scanning slider 113, and the Z-axis scanning slider 114 can move the array-type probe 111 in the X-axis direction, the Y-axis method, and the Z-axis direction, respectively. The θx rotating jig 115, the θy rotating jig 116, and the θz rotating jig 117 can rotate the array-type probe 111 in the θx direction, the θy direction, and the θz direction, respectively. As described above, the array-type probe 111 can move in the Y-axis direction and the Z-axis direction while moving and scanning in the X-axis direction, and can rotate in the θx direction, the θy direction, and the θz direction. Can do.

  In the present embodiment, the X-axis direction is the direction in which the array probe 111 and the material to be measured (not shown) move relatively in ultrasonic flaw detection, and the Y-axis and Z-axis are the X-axis. The axis is orthogonal to The θx direction is a rotation direction centering on an axis parallel to the X axis (that is, the roll direction), the θy direction is a rotation direction centering on an axis parallel to the Y axis (that is, the pitch direction), and θz is a Z axis. Rotation direction (ie, yaw direction) about an axis parallel to the axis.

  As shown in FIG. 2, the ultrasonic flaw detector 1 according to the embodiment of the present invention further includes a control unit 127, an X-axis scanning slider driving unit 121, a Y-axis scanning slider driving unit 122, and a Z-axis scanning slider. Driving means 123, θx rotating jig driving means 124, θy rotating jig driving means 125, θz rotating jig driving means 126, first storage means 128, second storage means 129, and matching means 130 Determination means 131 and output means 132.

  The control unit 127 includes an X-axis scanning slider driving unit 121, a Y-axis scanning slider driving unit 122, a Z-axis scanning slider driving unit 123, a θx rotating jig driving unit 124, a θy rotating jig driving unit 125, and a θz rotating jig driving. The means 126 is controlled. Further, the control unit 127 can drive the array-type probe 111 through a signal processing unit 140 described later, and can receive ultrasonic echoes obtained by the array-type probe 111 through the signal processing unit 140. The received ultrasonic echoes can be stored in the first storage unit 128 and the second storage unit 129.

  The X-axis scanning slider driving unit 121, the Y-axis scanning slider driving unit 122, and the Z-axis scanning slider driving unit 123 are based on the control signals generated by the control unit 127, respectively, and the X-axis scanning slider 112 and the Y-axis scanning slider 113, respectively. The Z-axis scanning slider 114 can be driven. Thereby, the array-type probe 111 can move in each direction.

  Further, the θx rotating jig driving means 124, the θy rotating jig driving means 125, and the θz rotating jig driving means 126 are based on the control signals generated by the control means 127, respectively, and the θx rotating jig 115 and the θy rotating jig driving means 126, respectively. The tool 116 and the θz rotating jig 117 can be driven. Thereby, the array-type probe 111 can rotate in each direction.

  An ultrasonic flaw detection apparatus 1 according to an embodiment of the present invention performs ultrasonic flaw detection by a total immersion method. That is, the array-type probe is in a state of being immersed in the liquid (that is, the contact medium) stored in the water tank 118 together with the measured material 21. Therefore, there is a liquid (contact catalyst) layer between each ultrasonic transducer 1111 and the material 21 to be measured, and the ultrasonic transducer 1111 and the material 21 to be measured are acoustically caused by this liquid (contact catalyst). Join. In addition to water, machine oil or glycerin oil can be used as the contact catalyst.

  As shown in FIG. 2, the ultrasonic transducers 1111 are arranged in series in the water tank 118 so as to face the surface of the measurement target material 21. The array-type probe 111 may be arranged so as to face the material to be measured 21 as described above, but is preferably arranged so as to follow the surface shape of the material to be measured 21.

  For example, as shown in FIG. 2, the material to be measured 21 is a cylindrical member having a substantially circular cross section, and the arrayed probe 111 and the material to be measured 21 are connected in the axial direction of the material to be measured 21 (that is, the X-axis direction). In the configuration in which flaw detection is performed by moving the probe relative to each other, it is preferable that the array-type probe 111 is formed in a substantially arc shape or an annular shape as shown in FIG. The ultrasonic transducers 1111 are arranged in series along the shape of the array-type probe 111. Each ultrasonic transducer 1111 is set such that the center of curvature or the center of the ring coincides with the center of the material 21 to be measured.

  Specifically, the array probe 111 includes 128 ultrasonic transducers 1111. These ultrasonic transducers 1111 are arranged in series and in an arc shape so that the radius of curvature is 62.5 mm at a pitch of 0.5 mm. A round bar having a diameter of 25 to 65 mm can be used as the material to be measured 21 which is the object of flaw detection by such an array-type probe 111.

  The first storage unit 128 can cumulatively store ultrasonic echoes at a plurality of predetermined positions of the array probe 111. Furthermore, it is possible to store the positional relationship between the array-type probe 111 and the material to be measured 21 when receiving the waveform of the ultrasonic echo.

  The second storage unit 129 can store ultrasonic echoes at a predetermined position of the array probe 111. The matching unit 130 compares the ultrasonic echoes at a plurality of positions stored in the first storage unit 128 with the ultrasonic echoes stored in the second storage unit 129. Of the plurality of ultrasonic echoes stored in the first storage unit 128, the closest or the same ultrasonic echo stored in the second storage unit 129 can be selected.

  The ultrasonic flaw detector 1 according to the embodiment of the present invention measures the state of the material to be measured 21 by a so-called “dynamic focus method (or sometimes referred to as a volume focus method)” and exists in the material to be measured 21. Abnormal discontinuities can be detected. Since the details of the ultrasonic flaw detection method using the “dynamic focus method” are publicly known (see, for example, Japanese Patent Application Laid-Open No. 2003-28846), they will be briefly described below, and detailed descriptions thereof will be omitted. This “abnormal discontinuity” is referred to as “a flaw (surface flaw and / or internal flaw)” in the present invention. “Flaws” include notches, cracks, pores, inclusions and the like.

  In the ultrasonic flaw detection method based on the “dynamic focus method”, a plurality of ultrasonic transducers 1111 provided in the array probe 111 are excited to irradiate ultrasonic waves toward the measured material 21, and the ultrasonic echoes are irradiated. Store and store ultrasonic phase synthesis at an arbitrary position by calculation. Thereby, an ultrasonic beam focused on an arbitrary position is calculated. That is, it is possible to calculate a plurality of ultrasonic beams in which a focus is set at an arbitrary position in the measurement target region by a single transmission / reception of ultrasonic waves. As described above, it is possible to perform scanning in the arrangement direction of the ultrasonic transducers 1111 of the array-type probe 111 over a wide range of the measurement target by transmitting and receiving ultrasonic waves once.

  The ultrasonic flaw detection apparatus 1 according to the embodiment of the present invention can implement the flaw detection method by the “dynamic focus method” as described above. For this purpose, a signal processing unit 140 and an arbitrary focal waveform synthesis unit 141 are provided.

  The signal processing unit 140 includes an ultrasonic pulse transmission / reception timing setting unit 142, an ultrasonic pulse generation unit 143, an ultrasonic echo reception unit 144, an A / D conversion unit 145, and a waveform storage unit 146.

  The ultrasonic pulse transmission / reception timing setting unit 142 can set the timing for exciting each ultrasonic transducer 1111 provided in the array probe 111 and can set the reception timing of the ultrasonic echo by each ultrasonic transducer 1111. . The ultrasonic pulse generator 143 generates an ultrasonic pulse at the timing set by the ultrasonic pulse transmission / reception timing setting unit 142. And each ultrasonic transducer | vibrator 1111 provided in the array type probe 111 can be excited independently, respectively. The excited ultrasonic transducer 1111 irradiates ultrasonic waves toward the outside (that is, the measurement target material 21).

  Further, each ultrasonic transducer 1111 provided in the array probe 111 can receive an ultrasonic echo at a timing set by the ultrasonic pulse transmission / reception timing setting means 142. The ultrasonic echo receiving means 144 can amplify the ultrasonic echo received by each ultrasonic transducer 1111. The A / D conversion unit 145 can convert the value of the ultrasonic echo received by each ultrasonic transducer 1111 and amplified by each ultrasonic echo reception unit 144 from an analog value to a digital value. The waveform storage unit 146 can store the value of the ultrasonic echo converted into a digital value by the A / D conversion unit 145.

  The signal processing unit 140 can repeat the operation in a predetermined short cycle from at least the transmission of the ultrasonic beam to the reception of the ultrasonic echo reflected on the bottom surface of the measurement target material 21. The waveform storage means 146 of the signal processing unit 140 can accumulate and store at least ultrasonic echoes from the reception of the surface echo height to the reception of the bottom echo.

  The ultrasonic echo stored in the waveform storage unit 146 of the signal processing unit 140 is sent to the arbitrary focus waveform synthesis unit 141. The arbitrary focus waveform synthesis unit 141 may perform ultrasonic phase synthesis at an arbitrary position in the measurement target region (that is, in the cross section of the measurement target material 21) based on the ultrasonic echo stored in the waveform storage unit 146. it can. That is, it is possible to calculate the ultrasonic beam focused on an arbitrary position in the cross section of the measured material 21 and the echo height thereof.

  The ultrasonic flaw detection method according to the embodiment of the present invention is as follows.

  First, the outline of the ultrasonic flaw detection method by the ultrasonic flaw detector 1 according to the embodiment of the present invention will be described.

  In order to perform high-accuracy ultrasonic flaw detection, the ultrasonic transducer and the material to be measured at each position in the relative movement direction between the ultrasonic transducer 1111 and the material to be measured 21 (that is, each position in the X-axis direction). It is necessary to maintain the relationship between the position and angle with the high accuracy. When using the array-type probe 111 having a plurality of ultrasonic transducers 1111, it is necessary to maintain the relative positions and angles of the ultrasonic transducers 1111 and the material to be measured 21 uniformly. There is.

  FIG. 3 is a diagram showing the tendency of changes in the water distance and the surface echo height when the positional relationship between the array-type probe 111 and the material to be measured is shifted in the Y-axis direction. FIG. 4 is a diagram showing the tendency of changes in the water distance and the surface echo height when the arrayed probe 111 is shifted in the θy direction. The “water distance” refers to the distance between each ultrasonic transducer 1111 and the material 21 to be measured.

  FIG. 3A is a cross-sectional view schematically showing the positional relationship between the array-type probe 111 and the material 21 to be measured. In the array-type probe 111, a plurality of ultrasonic transducers 1111 (in this case, the number is 128. The number in the figure is the number of the ultrasonic transducer) is arranged in series. As shown in FIG. 3A, at the “correct measurement position”, the arrayed probe 111 and the measured material 21 are concentric. As shown in FIGS. 3B and 3C, the surface echo height and water distance obtained from each ultrasonic transducer 1111 are substantially uniform at the “correct measurement position”. In other words, the “correct measurement position” is a position where the surface echo height and water distance obtained from each ultrasonic transducer 1111 are substantially uniform.

  On the other hand, as shown in FIGS. 3D and 3E, when the array-type probe 111 is moved in the positive direction in the Y-axis direction, each ultrasonic transducer 1111 is changed according to the moved position. The water distance of the material to be measured 21 is not uniform. Further, since the water distance and the angle with the measured material 21 also change, the surface echo height becomes non-uniform. Further, even when moving in the negative direction of the Y-axis direction, as shown in FIGS. 3 (f) and 3 (g), the surface echo height obtained by each ultrasonic transducer according to the moved position and each The water distance between the ultrasonic transducer and the material to be measured 21 is not uniform.

  FIG. 4A is a cross-sectional view schematically showing the positional relationship between the array-type probe 111 and the measured material 21. As shown in FIG. 4A, at the “correct measurement position”, the array probe and the material to be measured are in a concentric positional relationship. Then, as shown in FIGS. 4B and 4C, at the “correct measurement position”, the surface echo height and water distance obtained from each ultrasonic transducer are substantially uniform.

  On the other hand, as shown in FIGS. 4D and 4E, when the array probe moves in the positive direction of the θy direction, each ultrasonic transducer and the material to be measured are moved according to the moved position. The water distance changes. Further, since the water distance changes, the surface echo height also changes. Further, even when the head moves in the negative direction of the θy direction, as shown in FIGS. 4F and 4G, the surface echo height obtained by each ultrasonic transducer 1111 can be obtained according to the moved position. The water distance between each ultrasonic transducer 111 and the measured material 21 changes.

  As described above, when the array-type probe 111 is deviated from the “correct measurement position”, the surface echo height obtained by each ultrasonic transducer 1111 and each ultrasonic transducer 1111 and the material to be measured according to the deviated position. The water distance of 21 changes. As a result, the surface echo height and water distance may not be uniform among the ultrasonic transducers 1111.

  Therefore, in advance, the surface echo height and water distance and the positional relationship between the ultrasonic transducer and the material to be measured when the ultrasonic transducer is at the “correct measurement position” were changed in various ways from the “correct measurement position”. The surface echo height and water distance in the case are acquired.

  The “correct measurement position” refers to a position where the relative positions and angles of the respective ultrasonic transducers and the material to be measured are uniform. Details will be described later. The “water distance” refers to the distance between each ultrasonic transducer and the material to be measured as described above, and can be calculated from the time when the surface echo appears in the A scope waveform. The surface echo height and water distance acquired here are referred to as “correction data”.

  In actual flaw detection, the array-type probe is positioned at the “correct measurement position” based on the acquired correction data, and then actual flaw detection is performed. That is, before actual flaw detection is performed, ultrasonic waves for position correction of the array-type probe 111 are transmitted and received. Then, the surface echo height and water distance obtained in the transmission / reception of this ultrasonic wave are compared with the surface echo height and water distance of the “correction data”.

  Then, from among the data included in the “correction data”, the same one as that obtained in the transmission / reception of the ultrasonic wave, or the closest one is selected. The positional relationship between the ultrasonic transducer and the measured material when the selected surface echo height and water distance are obtained becomes the actual positional relationship between the ultrasonic transducer and the measured material. Therefore, based on this positional relationship, the ultrasonic transducer is moved to the “correct measurement position”. After that, the actual flaw detection is performed.

  According to such a method, ultrasonic flaw detection can always be performed at the “correct measurement position”. Therefore, the accuracy of flaw detection can be improved. In particular, even in ultrasonic flaw detection using an array-type probe, the positional relationship between each element and the material to be measured can be maintained uniformly by adjusting the rotation direction of θz, thereby improving flaw detection accuracy. be able to.

  Next, a detailed description will be given with reference to FIGS. FIG. 5 is a flowchart showing processing in the stage of obtaining correction data. FIG. 6 is a flowchart showing processing in a stage where actual ultrasonic flaw detection is performed.

  As shown in FIG. 5, in step S <b> 1-1, the measurement target material 22 for correction data acquisition is set in the ultrasonic flaw detector 1 according to the embodiment of the present invention, and the X-axis direction of the array-type probe 111. The position is determined. The measurement target material 22 for correcting data acquisition has the same outer diameter as the actual measurement target material 21 and has no “scratches” on the surface thereof.

  In step S1-2, ultrasonic waves are emitted from all the ultrasonic transducers 1111 of the array probe 111 toward the surface of the material 22 to be measured, and ultrasonic echoes are received in step S1-3. . Thus, an A scope waveform is obtained in step S1-4. From the obtained A scope waveform, the distance to each ultrasonic transducer 1111 and the surface of the measurement target material 22 for acquiring correction data (that is, the water distance) and the surface echo height are known.

  Then, from the obtained A scope waveform (that is, water distance and surface echo height), it is determined whether or not the array-type probe 111 is at the “correct measurement position”. The “correct measurement position” refers to a position where the surface echo height and water distance of each ultrasonic transducer 1111 are substantially equal to each other and the surface echo height is at a peak. At the position where such an A scope waveform is obtained, the distances between the ultrasonic transducers 1111 and the measurement target material 22 for acquiring correction data are equal to each other, and the ultrasonic transducers 1111 are on the YZ plane. They are parallel (in other words, an angle at which ultrasonic waves can be irradiated in a direction perpendicular to the axial direction (X-axis direction) of the measurement target material 22 for correction data acquisition). That is, it is a position where the measurement target material 22 for acquiring correction data and the array probe 111 are concentric.

  When the obtained surface echo height and water distance are not those at the “correct measurement position” (“No” in step S1-5), the position of the array-type probe 111 is set in step S1-6. Adjust and return to step S1-2. Thus, by repeating the operations from step S1-2 to step S1-6, the array-type probe 111 can be positioned at the “correct measurement position”.

  If the “correct measurement position” is obtained (in the case of “Yes” in step S1-5), then the array-type probe is centered on the “correct measurement position” within a predetermined range. The A scope waveform when 111 is shifted from the “correct measurement position” is acquired and stored in the first storage means in an accumulative manner. For example, the Y-axis direction position and the Z-axis direction position are within a range of ± 5 mm from the “correct measurement position”, and the θx rotation direction position, the θy rotation direction position, and the θz rotation direction position are at each position within a range of ± 5 deg. The A scope waveform is acquired and stored in the first storage means.

  Specifically, it can be realized by the following processing. First, the Y-axis direction position, the Z-axis direction position, the θx-direction position, and the θy-direction position are shifted by predetermined positions (steps S1-7, S1-8, S1-9, S1-10), and then fixed at the positions. Then, while moving the position in the θz direction at a predetermined pitch (step S1-11), ultrasonic irradiation (step S1-12), reception of ultrasonic echo (step S1-13), and acquisition of an A scope waveform (step S1-11) S1-14) and storing the acquired A scope waveform in the first storage means (step S1-15).

  When the storage of the A scope waveform at all the positions in the θz direction at the Y-axis direction position, the Z-axis direction position, the θx-direction position, and the θy-direction position is completed (in the case of “Yes” in S1-16), the θy direction Is shifted by a predetermined position (step S1-10), and the position in the θz direction is moved again at a predetermined pitch (step S1-11), while irradiation with ultrasonic waves (step S1-12) and reception of ultrasonic echoes (step S1). -13), acquiring the A scope waveform (step S1-14), and storing the acquired A scope waveform in the first storage means (step S1-15).

  Then, when all the θy is completed in the Y-axis direction position, the Z-axis direction position, and the θx-direction position (“Yes” in step S1-17), θx is changed by a predetermined position (step S1). −9), Steps S1-10 to Steps 1-17 are repeated. When all the positions in the θx direction at the Y-axis direction position and the Z-axis direction position are completed (“Yes” in S1-18), the Z-axis direction position is moved by a predetermined pitch (step S-8), and step S1 Repeat steps 1-18 from -9. When Steps S1-9 to Steps 1-18 are completed for all the Z-axis direction positions (“Yes” in Step S1-19), the Y-axis is moved by a predetermined pitch (Step S1). -7), Steps S1-8 to S1-19 are repeated at the Y-axis position.

  When the processing from step S1-8 to step S1-19 is completed for all the Y-axis direction positions (“Yes” in step S1-20), the Y-axis direction position, the Z-axis direction position, the θx-direction position, θy All the A scope waveforms when the direction position and the θz direction position are changed within a predetermined range are acquired and stored in the first storage unit 128. Thereby, the acquisition of the correction data is completed.

  As a result, the surface echo height and water distance at the “correct measurement position” and the surface echo height at positions where the distance and angle from the measured materials 21 and 22 are shifted within a predetermined range from the “correct measurement position”. The relationship between the distance and the water distance becomes clear. Conversely, if the array type probe 111 is deviated from the “correct measurement position” in the Y-axis position, Z-axis position, θx direction, θy direction, θz direction, what surface echo height and Whether the water distance can be obtained can be known from the surface echo height and the water distance stored in the first storage means.

  The correction data is obtained by the above processing and stored in the first storage unit 128. Next, the actual flaw detection process will be described with reference to FIG.

  In step S2-1, the array-type probe 111 is positioned at a predetermined position in the X-axis direction. In this case, it is not necessary to place the array probe 111 strictly at the “correct measurement position”. In step S2-2, ultrasonic irradiation is performed at the position, and an ultrasonic echo is received in step S2-3. Next, in step S2-4, an A scope waveform is calculated from the received ultrasonic echo, and in step S2-5, the calculated A scope waveform is stored in the second storage unit 129.

  Next, in step S2-6, data matching is performed. Specifically, it is as follows. The surface echo heights and water distances at a plurality of positions stored in the first storage unit 128 are read out and compared with the surface echo heights and water distances stored in the second storage unit 129. That is, the correction data stored in the first storage means (that is, the correct measurement position and the surface echo height and water distance acquired within a predetermined range from the position) are read, and these surface echo height and water distance are Then, the surface echo height and the water distance stored in the second storage means 129 are compared. Of the surface echo height and water distance stored in the first storage means 128, the data closest to or identical to the data of the surface echo height and water distance stored in the second storage means 129 is selected. .

  For example, among the plurality of surface echo heights and water distances stored in the first storage unit 128, first, the surface echo height having a value substantially equal to the surface echo height stored in the second storage unit 129 is predetermined. The number (for example, about 10) is selected. Then, the water distance corresponding to the selected surface echo height is compared with the water distance stored in the second storage means 129, and the second storage means 129 out of the water distance corresponding to the selected surface echo height. Select the value closest to the water distance stored in.

  As a specific method, various known methods such as a pattern matching method can be applied.

  The positions of the array-type probe 111 corresponding to the selected water distance are the Y-axis direction position, the Z-axis direction position, the θx-direction position, and the θy-direction at the X-axis direction position of the array-type probe 111. It is determined that the position is the position in the θz direction. Thereby, it can be seen how far the array type probe 111 is deviated from the “correct measurement position” in each direction.

  That is, the first storage means 128 stores the surface echo height and the water distance at each position within a predetermined range with the “correct measurement position” as the center. Therefore, when the surface echo height and water distance obtained by the array-type probe 111 at a certain position are equal to either the surface echo height or water distance stored in the first storage means 128, A position is considered to be a position approximately equal to the position corresponding to the equal surface echo height and water distance.

  Therefore, by comparing the surface echo height and water distance stored in the second storage unit 129 with the surface echo height and water distance stored in the first storage unit 128, the steps S2-1 to S2-1 are performed. The position of the array-type probe when the process of S2-5 is performed (strictly speaking, how much it deviates in each direction from the “correct measurement position”) is known.

  Conversely, a predetermined number of water distances that are substantially the same as the water distance stored in the second storage unit 129 are selected, and the surface echo height corresponding to the selected water distance and the second storage unit 129 are selected. And the surface echo height corresponding to the selected water distance is selected from the surface echo heights that are closest to the surface echo height stored in the second storage means 129. There may be.

  In step S2-7, the position of the array probe 111 is corrected. That is, the Y-axis position, the Z-axis position, the θx rotation direction position, the θy rotation direction position, and the θz rotation direction position are moved in the minus direction from the position at which the selected surface echo height and water distance are acquired. As a result, the array-type probe 111 is positioned at the “correct measurement position”.

  In step S2-8, the “dynamic focus method” flaw detection is performed at the moved position. Specifically, it is as follows. The ultrasonic pulse transmission / reception timing setting unit 142 generates a pulse transmission timing signal and transmits it to the ultrasonic pulse generation unit 143. The ultrasonic pulse generator 143 receives this signal and sends a spike pulse to the ultrasonic transducers 1111 provided in the array probe 111 at the same time. As a result, the ultrasonic transducers 1111 are excited simultaneously, and ultrasonic waves are emitted. The envelope of the ultrasonic wave emitted from each ultrasonic transducer 1111 is substantially equal to the array shape of the ultrasonic transducers 1111 in the array probe 111. That is, when the ultrasonic probe 111 is formed in an arc shape or an annular shape, the envelope of each ultrasonic wave is a concentric circular arc shape or an annular shape. When the array probe 111 is formed in a substantially straight line, the envelope becomes a substantially straight line, and the ultrasonic wave becomes a pseudo plane wave.

  The emitted ultrasonic wave propagates through the liquid layer, and a part thereof is reflected at the boundary between the liquid layer and the measured material 21 (that is, the surface of the measured material 21). Then, when the ultrasonic wave propagated inside the material to be measured 21 encounters an acoustic reflection surface such as a flaw existing inside the material to be measured 21, a part of the ultrasonic wave is reflected there. Further, a part of the ultrasonic wave that has reached the opposite surface of the measured material 21 (that is, the bottom surface of the measured material 21) is reflected there.

  Each ultrasonic transducer 1111 receives the surface echo height, the echo on the acoustic reflection surface, and the bottom surface echo. The ultrasonic echo receiving unit 144 amplifies the received ultrasonic echo, and the A / D conversion unit 145 converts the amplified ultrasonic echo from an analog value to a digital value. The waveform storage unit 146 stores the ultrasonic echo converted into the digital value together with the position in the depth direction of the measurement target material 21 and the position in the arrangement direction of the ultrasonic transducer 1111. Alternatively, it is stored in a predetermined address corresponding to the depth direction of the measured material 21 and the arrangement direction of the ultrasonic transducers 1111.

  The arbitrary focus waveform synthesizing unit 141 reads the ultrasonic echo stored in the waveform storage unit 146 in the depth direction of the measurement target material 21 and the arrangement direction of the ultrasonic transducer 1111, while reading the dynamic focus method (according to the dynamic focus method). For details of the scanning method, refer to Japanese Patent Application Laid-Open No. 2003-28846).

  The determination unit 131 determines whether or not the ultrasonic echo is defective based on the scanning result. That is, if the echo height is greater than or equal to a predetermined threshold, it is determined that the flaw is a defect. The output unit 132 outputs the determination result by the determination unit 131.

  When the process is completed for all X-axis direction positions (that is, for all flaw detection ranges) (“Yes” in step S2-9), the process ends. If not completed ("No" in step S2-9), the array-type probe 111 is moved to the next position in the X-axis direction, and the processes in steps S2-2 to S2-8 are performed.

  According to such a configuration, ultrasonic flaw detection can be performed at the correct measurement position at any position in the X-axis direction. Therefore, the accuracy of flaw detection can be improved. In particular, even in the ultrasonic flaw detection using the array probe 111, the positional relationship between each ultrasonic transducer 1111 and the measured material 21 can be maintained uniformly by adjusting the rotation direction of θz. The accuracy can be improved.

  While various embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments or examples, and various modifications can be made without departing from the spirit of the invention. Needless to say.

  For example, although the ultrasonic flaw detection apparatus and the ultrasonic flaw detection method according to the above-described embodiment are those that perform ultrasonic flaw detection by the total immersion method, the present invention performs ultrasonic flaw detection by the total immersion method. It is not limited to what is implemented.

  In the above-described embodiments and examples, the configuration in which the material to be measured is applied to a columnar body having a substantially circular cross section is shown, but the cross sectional shape of the material to be measured is not limited to a substantially circular shape. For example, the present invention can be applied to a material to be measured having an arbitrary cross-sectional shape such as an ellipse, other curved surface, or polygon. In that case, the array-type probe may be shaped to face the surface of the material to be measured, and more preferably, the array-type probe should be shaped to follow the surface of the material to be measured. Good.

  In the above-described embodiment, the ultrasonic flaw detector and the ultrasonic flaw detection method having the array-type probe have been described. However, the probe is not limited to the array-type probe. It may be an ultrasonic flaw detector provided with a probe having the ultrasonic transducer. In this case, there is no need to consider θz, and it is not necessary to consider the mutual relationship between the ultrasonic transducers as in the array type probe. The same configuration can be applied.

1 is an external perspective view schematically showing a configuration of an ultrasonic flaw detector according to an embodiment of the present invention. It is the block diagram which showed typically the structure of the ultrasonic flaw detector concerning embodiment of this invention. (A) is a cross-sectional view schematically showing the positional relationship between the array-type probe and the material to be measured, and (b) shows the water distance when the array-type probe is at the “correct measurement position”. , (C) shows the peak value of the surface echo height when the array probe is at the “correct measurement position”, and (d) shows the array probe in a positive direction in the Y-axis direction. (E) shows the peak value of the surface echo height when the array-type probe is displaced in the positive direction in the Y-axis direction, and (f) shows the array-type probe. The water distance when the probe is displaced in the negative direction in the Y-axis direction is shown, and (g) is the peak value of the surface echo height when the array type probe is displaced in the negative direction in the Y-axis direction. Indicates. (A) is a cross-sectional view schematically showing the positional relationship between the array-type probe and the material to be measured, and (b) shows the water distance when the array-type probe is at the “correct measurement position”. , (C) shows the peak value of the surface echo height when the array-type probe is at the “correct measurement position”, and (d) shows that the array-type probe is displaced in the positive direction in the θy direction. (E) shows the peak value of the surface echo height when the array-type probe is displaced in the positive direction of the θy direction, and (f) shows the array-type probe. Indicates the water distance when the sensor is displaced in the negative direction in the θy direction, and (g) indicates the peak value of the surface echo height when the array type probe is shifted in the negative direction in the θy direction. It is the flowchart which showed the operation | movement of the step which obtains the data for correction | amendment of the ultrasonic flaw detector concerning embodiment of this invention. It is the flowchart which showed the operation | movement of the step which actually performs ultrasonic testing of the ultrasonic testing apparatus concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic flaw detector 111 Array type probe 1111 Ultrasonic transducer 112 X-axis scanning slider 113 Y-axis scanning slider 114 Z-axis scanning slider 115 θx rotating jig 116 θy rotating jig 117 θz rotating jig 118 Water tank 121 X Axis scanning slider driving means 122 Y-axis scanning slider driving means 123 Z-axis scanning slider driving means 124 θx rotating jig driving means 125 θy rotating jig driving means 126 θz rotating jig driving means 127 Control means 128 First storage means 129 First Two storage means 130 Matching means 131 Judging means 132 Output means 140 Signal processing section 141 Arbitrary focus waveform synthesis section 142 Ultrasonic pulse transmission / reception timing setting means 143 Ultrasonic pulse generation means 144 Ultrasonic echo reception means 145 A / D conversion means 146 Waveform Storage means 21 Material 22 Material to be measured for correction data acquisition

Claims (5)

An array-type probe having an ultrasonic transducer that can receive ultrasonic echoes by irradiating the material to be measured with ultrasonic waves;
Driving means capable of changing the relative position and / or relative angle between the between the sequence type probe measured material,
A plurality of pre-Symbol ultrasonic echo waveforms obtained by the ultrasonic transmission and reception for performing position correction of the array type probe, the said sequences form probe at the time of reception of ultrasonic echo waveform First storage means capable of storing the positional relationship with the material to be measured;
Second storage means capable of storing the waveform of the ultrasonic echo received at a predetermined position in the X-axis direction, with the direction in which the arrayed probe and the material to be measured move relative to each other as the X-axis direction ;
The waveform stored in the second storage means is compared with the waveform stored in the first storage means, and the waveform stored in the second storage means is the same or most equal from the plurality of waveforms stored in the first storage means. A matching means for selecting a waveform to be approximated;
With
It said drive means, wherein the surface of the said array-type probe matching means corresponding to the selected waveform based on the positional relationship of the measured material is obtained said sequences form probe from a plurality of ultrasonic transducers it is moved to the measurement positions echo height and horizontal distance is substantially uniform, the ultrasonic flaw detection apparatus characterized by capable of performing flaw in surveying position. The first storage means and the second storage means can store a waveform including information on the position from the ultrasonic transducer to the measured material and the surface echo height,
The matching unit includes one of a distance between the ultrasonic transducer having a waveform stored in the first storage unit and the measured material, or a height of the surface echo, and an ultrasonic transducer having a waveform stored in the second storage unit. Compare the distance to the material to be measured or the same surface echo height,
From the plurality of ones stored in the first storage unit, select a plurality of the ones that approximate the same one stored in the second storage unit,
Comparing the other corresponding to the selected plurality of the one with the same other stored in the second storage means,
The ultrasonic flaw detector according to claim 1, wherein the most approximated waveform is the same or most approximated.   The probe includes a plurality of ultrasonic transducers, and the driving unit can rotate the probe in a yaw direction with respect to a direction of relative movement of the probe and the material to be measured. The ultrasonic flaw detector according to claim 1 or 2. An ultrasonic flaw detection method using the ultrasonic flaw detector according to any one of claims 1 to 3,
Storing a waveform of an ultrasonic echo in accordance with the position of the probe and the material to be measured in the first storage means;
Irradiating the material to be measured with ultrasonic waves;
Receiving an ultrasonic echo;
Storing the received waveform of the ultrasonic echo in the second storage means;
Selecting a waveform that is the same or most approximate to the waveform stored in the second storage means from the waveform corresponding to the position of the probe stored in the first storage means;
Correcting the position of the probe from a waveform corresponding to the position of the selected probe;
Performing ultrasonic flaw detection at the corrected position;
An ultrasonic flaw detection method comprising: The step of storing the waveform of the ultrasonic echo according to the position of the probe and the material to be measured in the first storage means,
A correct measurement position is detected, and at a plurality of locations within a predetermined range including the detected correct measurement position, an ultrasonic wave is received by irradiating the measured material with ultrasonic waves, and a waveform of the received ultrasonic echo The ultrasonic flaw detection method according to claim 4, wherein the method is cumulatively stored in the first storage means.

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