JP5738034B2 - Ultrasonic flaw detector - Google Patents

Description

  The present invention relates to an ultrasonic flaw detector that transmits ultrasonic waves to a subject and detects defects in the subject.

  As an apparatus for nondestructive inspection of a defect in a subject, for example, there is an ultrasonic flaw detection apparatus. This ultrasonic flaw detector is an apparatus that detects a defect in a subject by transmitting ultrasonic waves to the subject, receiving the transmitted ultrasonic waves from the subject, and analyzing the ultrasonic waves.

  As such an ultrasonic flaw detector, there exists a thing of the following patent document 1, for example.

  This ultrasonic flaw detector uses the defect data detected by a total of three probes, that is, two inclined probes and one vertical probe, so that the arithmetic unit can detect the direction and length of the defect in three dimensions. It is a thing to ask for.

  All of the three probes are reflection type phased arrays. The three probes are arranged so that ultrasonic waves can be output in different directions within a flaw detection cross section perpendicular to the scanning direction. The arithmetic unit obtains the length and direction of the defect in the flaw detection section by synthesizing the defect data detected by the three probes. Then, by moving the three probes in the target scanning direction, the direction and length of the defect in three dimensions are obtained from the length and direction of the defect in the flaw detection section at each position in the scanning direction. ing.

JP 2007-46913 A

  Although the technique described in Patent Document 1 can surely determine the length and orientation of the defect in the subject, since it requires three phased arrays, there is a problem that the apparatus cost increases.

  Accordingly, an object of the present invention is to provide an ultrasonic flaw detection apparatus that can detect the length and orientation of a defect in a subject while suppressing the apparatus cost.

An ultrasonic flaw detector according to the invention for solving the above-mentioned problems is
A probe unit having a transmission probe that transmits ultrasonic waves to a subject and a reception probe that receives ultrasonic waves transmitted by the transmission probe and transmitted through the subject. In the ultrasonic flaw detector described above, a surface of the subject passing through the ultrasonic wave propagation path received by the receiving probe from the transmission probe of the probe unit via the subject is detected. and then, with having該探probe unit, in該探probe unit, a multi-directional testing means for performing ultrasonic testing of three or more該探wound section which intersects oriented in different directions, the multi-directional When the flaw detection means is scanned in one direction along the surface of the subject, each flaw detection is performed when the multidirectional flaw detection means detects a defect in each of the three or more flaw detection cross sections. Received at each of the ultrasonic flaws in cross section By using the apparent defect length of which is determined from the change caused by the scanning of the intensity of the ultrasonic wave intensity and ultrasonic, orientation of the three or more to both vertical imaginary plane direction of the defect inspection section And a calculating means for obtaining the length.

  In the ultrasonic flaw detection apparatus, even if each of the transmission probe and the reception probe constituting the probe unit is not a phased array but a single transducer type ultrasonic probe, three or more The direction and length of the defect in the virtual in-plane direction perpendicular to any of the three or more flaw detection cross sections can be obtained from the ultrasonic flaw detection result in the flaw detection cross section. Therefore, in the ultrasonic flaw detection apparatus, the apparatus cost can be suppressed.

Here, in the ultrasonic flaw detection apparatus, the multi-directional flaw detection means intersects with three or more probe units and the flaw detection cross sections in which the probe units perform ultrasonic flaws in different directions. And a connection support mechanism for connecting the three or more probe units to each other, and of the three or more probe units, a third probe with respect to the flaw detection section of the first probe unit. The flaw detection cross section of the probe unit intersects at an angle of 90 °, the flaw detection cross section of the second probe unit intersects with the flaw detection end surface of the first probe unit at an angle other than 90 °, and the computing means When a defect is detected in each of the three or more probe units, each determined from the change accompanying the scanning of the intensity of ultrasonic waves received by the first probe unit and the third probe unit. Using the apparent defect length, Any one of a positive end in the scanning direction of the defect and a negative end in the scanning direction of the defect is the transmission probe with respect to the reception probe of the third probe unit. Each apparent defect length determined from a change in the intensity of ultrasonic waves received by the first probe unit and the second probe unit ) Then, out of the positive end and the negative end of the defect, the determined end faces the transmitting probe side, and the direction and length of the defect in the virtual in-plane direction are obtained. Also good.

  In the ultrasonic flaw detection apparatus, the direction and length of the defect in the virtual in-plane direction perpendicular to the flaw detection cross section can be obtained by scanning the subject once with three or more probe units.

Further, in the ultrasonic flaw detector, the multi-directional flaw detection means includes the probe unit, along the flaw detection cross section for the probe unit, and between the transmission probe and the reception probe. A support mechanism that rotatably supports the probe unit about a rotation axis passing through the middle of the center, and the calculation means scans the multidirectional flaw detection means in one direction along the surface of the subject. When a defect is detected, the probe unit is rotated at the position of the defect, and the rotation angle with the minimum intensity among the ultrasonic intensity received at each rotation angle is used. The direction of the defect in the virtual in-plane direction is obtained, and the multidirectional flaw detection means having the probe unit set at a rotation angle different from the rotation angle of the minimum defect length is scanned in the one direction. Received by the probe unit. Alternatively, the length of the defect in the virtual in-plane direction may be obtained using an apparent defect length determined from the change in the ultrasonic intensity accompanying the scanning and the direction of the defect.

  In the ultrasonic flaw detection apparatus, one probe unit and each of the transmission probe and the reception probe constituting the probe unit is not a phased array, but a single transducer ultrasonic probe. Even in the case of a touch element, the direction and length of a defect in a virtual in-plane direction perpendicular to the flaw detection cross section can be obtained. Therefore, the ultrasonic flaw detector can further reduce the device cost.

  Further, in the ultrasonic flaw detection apparatus, since the defect direction is obtained from the rotation angle of the probe unit, it is possible to reduce the calculation load for obtaining the defect direction.

  The ultrasonic flaw detection apparatus further includes a rotation angle sensor that detects a rotation angle of the probe unit around the rotation axis, and the calculation unit is configured to detect the rotation angle received by the probe unit. A storage unit that stores the intensity of ultrasonic waves in association with the rotation angle, and a rotation angle that is associated with the minimum intensity among the ultrasonic intensities stored in the storage unit is extracted from the storage unit. May be.

  In the ultrasonic flaw detector, the rotation angle of the flaw detector unit corresponding to the direction of the defect can be automatically acquired.

  In the present invention, even if each of the transmission probe and the reception probe constituting the probe unit is not a phased array but a single transducer type ultrasonic probe, it has three or more flaw detection cross sections. From the ultrasonic flaw detection result, the direction and length of the defect in the virtual in-plane direction perpendicular to any of the three or more flaw detection cross sections can be obtained.

  Therefore, according to the present invention, the apparatus cost can be suppressed.

It is explanatory drawing which shows the structure of the ultrasonic flaw detector in 1st embodiment which concerns on this invention. It is the II-II sectional view taken on the line in FIG. It is explanatory drawing which shows the relationship between the output from each probe unit and the defect in a subject in 1st embodiment which concerns on this invention. Explanatory drawing which shows the relationship between the apparent defect length recognized by the output from each probe unit in 1st embodiment which concerns on this invention, and the direction and length of a defect in the virtual surface perpendicular | vertical to a flaw detection cross section. It is. It is explanatory drawing which shows the structure of the ultrasonic flaw detector in 2nd embodiment which concerns on this invention. It is the VI-VI sectional view taken on the line in FIG. It is explanatory drawing which shows the probe unit in rotation of the ultrasonic flaw detector in 2nd embodiment which concerns on this invention. It is explanatory drawing which shows the relationship between the apparent defect length recognized by the output from the probe unit in 2nd embodiment which concerns on this invention, and the direction and length of a defect in the virtual surface perpendicular | vertical to a flaw detection cross section. is there.

  Embodiments of an ultrasonic flaw detector according to the present invention will be described below in detail with reference to the drawings.

"First embodiment"
First, a first embodiment of an ultrasonic flaw detector will be described with reference to FIGS.

  As shown in FIG. 2, the ultrasonic flaw detector according to the present embodiment transmits a transmission probe 11 that transmits an ultrasonic wave U to a subject 1, and the transmission probe 11 transmits and transmits the subject 1. Probe units 10a, 10b, and 10c each having a reception probe 12 for receiving the ultrasonic wave U are provided. Each of the transmission probe 11 and the reception probe 12 is not a phased array but a single transducer type ultrasonic probe.

  Each of the transmission probe 11 and the reception probe 12 includes a probe main body 13 and a shoe 14 disposed between the probe main body 13 and the subject 1. The side surface of the shoe 14 is, for example, a right triangle, and the surface of the probe main body 13 is inclined with respect to the surface of the subject 1, so that the ultrasonic wave is transmitted and received by the probe main body 13. Thus, the direction of input / output of ultrasonic waves to the subject 1 is changed. Here, the probe body 13 and the shoe 14 are separate, but the probe body 13 and the shoe 14 may be integrated.

  The subject 1 is obtained by butt welding two members 2 to be joined. The ultrasonic flaw detector according to the present embodiment has the presence or absence of the defect 4 of the welded portion 3 in the subject 1 and the direction and length of the defect 4. Is detected.

  As shown in FIGS. 1 and 2, the ultrasonic flaw detector according to the present embodiment is connected to three probe units 10a, 10b, and 10c and the three probe units 10a, 10b, and 10c. The support mechanism 20 and the probe units 10a, 10b, and 10c are driven and controlled, and the ultrasonic waves received by the reception probes 12 of the probe units 10a, 10b, and 10c are analyzed to check for the presence or absence of the defect 4, And a controller 40 for detecting the direction and length of the defect 4.

  The connection support mechanism 20 includes a connection rod 21 for connecting the transmission probe 11 and the reception probe 12 constituting the probe units 10a, 10b, and 10c, the transmission probe 11, and the reception probe. 12 to the connecting rod 21, a connecting shaft 28 for connecting the connecting rods 21 for each of the probe units 10a, 10b, and 10c, and a connecting rod for each of the probe units 10a, 10b, and 10c. And a support frame 30 to which 21 is fixed.

  The connecting rods 21 for each of the three probe units 10a, 10b, and 10c, that is, the three connecting rods 21, overlap each other at the center in the longitudinal direction and are connected by a connecting shaft 28. Among the three connecting rods 21, the second connecting rod 21b forms an angle of 45 ° clockwise with respect to the first connecting rod 21a, and the third connecting rod 21c rotates clockwise with respect to the first connecting rod 21a. It is fixed to the support frame 30 so as to form an angle of 90 ° in the direction. A direction that forms an angle of 45 ° counterclockwise with respect to the first connecting rod 21a forms a scanning direction S for the ultrasonic flaw detector according to the present embodiment. In the present embodiment, when the scanning direction S is used as a reference, the first connecting rod 21a forms an angle of 45 ° and the second connecting rod 21b forms an angle of 90 ° in the clockwise direction. The rod 21c forms an angle of 135 °. Hereinafter, the probe unit 10a attached to the first connecting rod 21a is the first probe unit, and the probe unit 10b attached to the second connecting rod 21b is the second probe unit. The probe unit 10c attached to the third connecting rod 21c is a third probe unit.

  On both ends of each connecting rod 21, a long hole 22 is formed that extends in the direction in which the connecting shaft 28 extends and extends in the longitudinal direction of the connecting rod 21.

  The attachment 24 (FIG. 2) is connected to an attachment seat 25 fixed to the probe main body 13 of the transmission probe 11 and the reception probe 12, and a connection pin 26 attached to the attachment seat 25. And a retaining bolt 27 screwed into the end of the pin 26. The connecting pin 26 is inserted through the long hole 22 of the connecting rod 21. The transmission probe 11 and the reception probe 12 can be moved relative to the connection rod 21 in the direction in which the long hole 22 of the connection rod 21 extends together with the connection pin 26. On the other hand, when the retaining bolt 27 is screwed into the connection pin 26, the relative movement of the transmission probe 11, the reception probe 12, and the connection pin 26 is restricted. For this reason, by moving the transmission probe 11 and the reception probe 12 of each probe unit 10a, 10b, 10c with respect to the connecting rod 21, the transmission probe 11 and the reception probe 12 are moved. The distance between them can be changed, and the transmission probe 11 and the reception probe 12 can be fixed to the connecting rod 21 at a desired distance.

  In the present embodiment, a surface in the subject 1 passing through an ultrasonic wave propagation path received by the receiving probe 12 from the transmitting probe 11 via the subject 1 is defined as a flaw detection cross section P, and three probe units. The flaw detection cross sections P1, P2, and P3 for the ultrasonic flaw detector are set for each of 10a, 10b, and 10c. The flaw detection cross sections P of the three probe units 10a, 10b, and 10c intersect in different directions, and the flaw detection cross sections P1, P2, and P3 of the probe units 10a, 10b, and 10c The connecting rods 21a, 21b, and 21c to which the tentacle units 10a, 10b, and 10c are attached are parallel to the extending direction. For this reason, the flaw detection cross section P1 for the first probe unit 10a forms an angle of 45 ° in the clockwise direction with respect to the scanning direction S, and the flaw detection cross section P2 for the second probe unit 10b is scanned. 90 ° in the clockwise direction with respect to the direction S, and the flaw detection cross section P3 for the third probe unit 10c forms an angle of 135 ° in the clockwise direction with respect to the scanning direction S.

  The controller 40 drives and controls the probe units 10a, 10b, and 10c. The controller 40 gives instructions to the drive control circuit 41, and receives signals from the probe units 10a, 10b, and 10c. It has CPU42 which detects the presence or absence of the defect 4, the direction and length of the defect 4, and the display 43 which displays various data etc., and the memory 44 by analyzing the ultrasonic wave which the toucher 12 received. The memory 44 stores in advance a program for analyzing the ultrasonic waves received by the receiving probe 12 to detect the presence or absence of the defect 4 and for detecting the direction and length of the defect 4.

  In the present embodiment, the multidirectional flaw detection means includes three probe units 10a, 10b, and 10c, and a connection support mechanism 20 that connects them together. Further, the computing means includes a memory 44 in which this program is stored and a CPU 42 that executes this program.

  Next, how to handle and operate the ultrasonic flaw detector according to the present embodiment described above will be described.

  First, in consideration of the thickness of the subject 1, ultrasonic waves transmitted from the transmission probe 11 of the probe units 10a, 10b, and 10c to the subject 1 are reflected by the back surface of the subject 1 and received. The interval between the transmission probe 11 and the reception probe 12 of each probe unit 10a, 10b, 10c is adjusted so that the probe 12 can receive the signal. The intervals between the transmission probe 11 and the reception probe 12 of the probe units 10a, 10b, and 10c are the same in the probe units 10a, 10b, and 10c.

  Next, on the surface of the subject 1, the three probe units 10a, 10b, and 10c and the connection support mechanism 20 that connects the three probe units 10a, 10b, and 10c to each other are placed. At this time, as shown in FIG. 1, the connection shaft 28 of the connection support mechanism 20 is positioned on the welded portion 3 of the subject 1, and the scanning direction S for the ultrasonic flaw detector is parallel to the longitudinal direction of the welded portion 3. The three probe units 10a, 10b, and 10c and the connection support mechanism 20 are set on the surface of the subject 1 so as to be.

  Next, after the probe units 10a, 10b, and 10c are driven by the controller 40, the three probe units 10a, 10b, and 10c and the connection support mechanism 20 are moved in the scanning direction S, that is, the subject 1 It moves along the welding part 3.

  As the three probe units 10a, 10b, and 10c move, the CPU 42 of the controller 40 receives the output shown in FIG. 3 from each of the probe units 10a, 10b, and 10c via the drive control circuit 41. 3, the horizontal axis indicates the position of the probe units 10a, 10b, and 10c in the scanning direction S, and the vertical axis indicates the reception probe 12 of the probe units 10a, 10b, and 10c. Shows the signal intensity of the ultrasonic echo. The signal intensity of the ultrasonic echo decreases when there is a defect. For this reason, the CPU 42 constituting the calculation means analyzes the signal intensity of the ultrasonic echo according to the position of the probe unit from each probe unit 10a, 10b, 10c, and the signal intensity starts to decrease. The length from the position of the probe unit to the position of the probe unit where the signal intensity has returned to the original level again is recognized as the apparent defect length detected by the probe unit. .

  Here, it is assumed that there are only two probe units, the first probe unit 10a and the second probe unit 10b. In this case, as shown in FIG. 3, the section S1 in which the signal intensity is reduced in the output of the first probe unit 10a and the section in which the signal intensity is reduced in the output of the second probe unit 10b. The defect 4 exists in the area A where S2 overlaps. However, the defect 4 specified by the region A is the defect on the (−) scanning direction S side corresponding to the position where the signal intensity starts to decrease due to the output from the first probe unit 10a. Of the defect 4 and the edge e2 of the defect on the (+) scanning direction S side, and the direction of the defect 4 cannot be specified. For this reason, in this embodiment, three probe units 10a, 10b, and 10c are provided in order to specify the direction of the defect 4.

  When receiving the outputs from the probe units 10a, 10b, and 10c, the CPU 42 that constitutes the calculation means first calculates the probe units from the outputs of the probe units 10a, 10b, and 10c as described above. The apparent defect length for each output of 10a, 10b, and 10c is recognized.

  Next, the CPU 42 apparent length L1 of the defect 4 recognized from the output of the first probe unit 10a and apparent length of the defect 4 recognized from the output of the third probe unit 10c. When the magnitude relationship with L3 is compared and it is determined that L1> L3, this defect 4 has an end of the defect 4 on the (+) scanning direction S side is on the transmission probe 11 side (in FIGS. 3 and 4). As shown in FIG. 4, the orientation of the defect 4 is determined using an angle θ in the counterclockwise direction with reference to an imaginary line parallel to the scanning direction S.

At this time, the CPU 42 apparent length L1 of the defect 4 recognized from the output of the first probe unit 10a and apparent length of the defect 4 recognized from the output of the second probe unit 10b. By substituting L2 into the following (Equation 1), the orientation θ of the defect 4 is obtained.
tan θ = (L1−L2) / L2 (Equation 1)

Next, the CPU 42 substitutes the orientation θ of the defect 4 and the apparent length L2 of the defect 4 recognized from the output of the second probe unit 10b into the following (Equation 2) to obtain the defect 4 Is obtained.
L0 = L2 / cosθ (Equation 2)

  Then, the CPU 42 causes the display 43 to output the obtained orientation θ and length L0 of the defect 4. Note that the orientation θ and the length L0 of the defect 4 obtained here are all in a virtual plane perpendicular to the three flaw detection cross sections P1, P2, and P3, that is, in a plane parallel to the surface of the subject 1. This is the direction and length of the defect 4.

  In addition, the CPU 42 apparent length L1 of the defect 4 recognized from the output of the first probe unit 10a and the apparent length L3 of the defect 4 recognized from the output of the third probe unit 10c. When it is determined that L1 ≦ L3 as a result of the comparison of the magnitude relationship between the defect 4 and the defect 4, the end of the defect 4 on the (−) scanning direction S side is the transmission probe 11 side (upper side in FIG. 4). The direction of the defect 4 is determined using the angle θ ′ in the clockwise direction with reference to an imaginary line parallel to the scanning direction S.

At this time, the CPU 42 apparent length L1 of the defect 4 recognized from the output of the first probe unit 10a and apparent length of the defect 4 recognized from the output of the second probe unit 10b. By substituting L2 into the following (Equation 1a), the orientation θ ′ of the defect 4 is obtained.
tan θ ′ = (L1−L2) / L2 (Equation 1a)

Next, the CPU 42 substitutes the orientation θ ′ of the defect 4 and the apparent length L2 of the defect 4 recognized from the output of the second probe unit 10b into the following (Equation 2a) to obtain the defect A length L0 of 4 is obtained.
L0 = L2 / cos θ ′ (Equation 2a)

  Then, the CPU 42 outputs the obtained orientation θ ′ and length L 0 of the defect 4 to the display 43.

  As described above, in the present embodiment, the direction and length of the defect 4 in the subject 1 can be detected. In addition, in this embodiment, although the three probe units 10a, 10b, and 10c are used, the transmission probe 11 and the reception probe 12 that constitute each of the probe units 10a, 10b, and 10c are Both are not phased arrays but single transducer type ultrasonic probes, so that the cost of the apparatus can be reduced.

  In the present embodiment, the connecting rod 21 for each of the probe units 10a, 10b, and 10c, the fixture 24, the connecting shaft 28 that connects the connecting rods 21 to each other, and the support to which the connecting rods 21 are fixed. The connection support mechanism 20 is configured to include the frame 30. The connection support mechanism 20 is configured so that the flaw detection cross sections P1, P2, and P3 of the probe units 10a, 10b, and 10c are directed in different directions. Any mechanism may be used as long as the three probe units 10a, 10b, and 10c can be connected to each other.

"Second embodiment"
Next, a second embodiment of the ultrasonic flaw detector will be described with reference to FIGS.

  As shown in FIGS. 5 and 6, the ultrasonic flaw detection apparatus according to the present embodiment is provided with one probe unit 10, along the flaw detection cross section P for the probe unit 10, and with the transmission probe 11 and the reception. A support mechanism 20a that rotatably supports the probe unit 10 about a rotation axis that passes through the middle of the probe 12, a rotation angle sensor 39 that detects the rotation angle of the probe unit 10, and a controller 40a. And.

  The probe unit 10 of this embodiment is the same as the probe unit of the first embodiment.

  The support mechanism 20a includes a connection rod 29 for connecting the transmission probe 11 and the reception probe 12 constituting the probe unit 10, and a connection rod 29 for connecting the transmission probe 11 and the reception probe 12. And a support frame 30 that supports the connecting rod 29, the rotation shaft 28a, and the rotation angle sensor 39.

  A rotation shaft 28 a is provided at the center in the longitudinal direction of the connecting rod 29. Further, on both end sides in the longitudinal direction of the connecting rod 29, like the connecting rod 21 of the first embodiment, there are elongated holes 22 that penetrate in the direction in which the rotating shaft 28 a extends and extend in the longitudinal direction of the connecting rod 29. Is formed.

  The attachment 24 is attached to the attachment seat 25, which is fixed to the probe body 13 of the transmission probe 11 and the reception probe 12, and the attachment seat 25, similarly to the attachment 24 of the first embodiment. And a retaining bolt 27 screwed into the end of the connecting pin 26.

  The support frame 30 a includes a rectangular frame main body 31 and a connecting beam 32 that connects a pair of frame beams facing each other in the frame main body 31. A rotating shaft 28 a provided at the center of the connecting rod 29 is rotatably attached to the center in the longitudinal direction of the connecting beam 32. The rotation angle sensor 39 is fixed on the coupling beam 32 at a position facing the rotation shaft 28a.

  The controller 40a includes a drive control circuit 41, a CPU 42, a display 43, and a memory 44, as in the first embodiment. The drive control circuit 41 of the present embodiment drives and controls the transmission probe 11 and the reception probe 12 of the probe unit 10 and drives and controls the rotation angle sensor 39. In addition, the memory 44 of this embodiment stores in advance a program for analyzing the ultrasonic waves received by the reception probe 12 to detect the presence or absence of the defect 4 and for detecting the direction and length of the defect 4. It is remembered. Unlike the first embodiment, this embodiment is based on the output from the rotation angle sensor 39 and the output from one probe unit 10 and the presence or absence of the defect 4 in the subject 1 and the direction and length of the defect 4. This program is different from the program of the first embodiment.

  In the present embodiment, the multidirectional flaw detection means includes one probe unit 10 and a support mechanism 20a that rotatably supports the probe unit 10. Further, the computing means includes a memory 44 in which this program is stored and a CPU 42 that executes this program.

  Next, how to handle and operate the ultrasonic flaw detector according to the present embodiment described above will be described.

  Also in the present embodiment, first, the ultrasonic wave transmitted from the transmission probe 11 of the probe unit 10 to the subject 1 is reflected by the back surface of the subject 1 and received by the reception probe 12. The interval between the transmission probe 11 and the reception probe 12 of the probe unit 10 is adjusted.

  Next, the probe unit 10 and a support mechanism 20 a that supports the probe unit 10 are placed on the surface of the subject 1. At this time, as shown in FIG. 5, the rotation shaft 28 a of the support mechanism 20 a is positioned on the welded portion 3 of the subject 1, and the flaw detection cross section P for the probe unit 10 is in the longitudinal direction of the welded portion 3. For example, in order to be vertical, in other words, the line segment connecting the transmission probe 11 and the reception probe 12 constituting the probe unit 10 is, for example, perpendicular to the longitudinal direction of the weld 3. The touch unit 10 and the support mechanism 20a are set on the surface of the subject 1.

  Next, after the probe unit 10 is driven by the controller 40 a, the probe unit 10 and the support mechanism 20 a are moved along the welded portion 3 of the subject 1. In the present embodiment, this moving direction is the scanning direction S of the ultrasonic flaw detector with respect to the subject 1.

  The CPU 42 of the controller 40 a receives the output of the probe unit 10 via the drive control circuit 41 in the process of moving the probe unit 10. When receiving the output from the probe unit 10, the CPU 42 determines whether or not there is a section in which the ultrasonic echo signal intensity is reduced, and there is a section in which the ultrasonic echo signal intensity is reduced. In this case, a position where the defect 4 is present in the scanning direction S, that is, a section in which the signal intensity of the ultrasonic echo in the scanning direction S is reduced is indicated along with the presence of the defect 4 in the subject 1. It is displayed on the display 43. Here, the fact that the defect 4 is present in the subject 1 and the position where the defect 4 is present are displayed on the display 43, but the output from the probe unit 10 is simply displayed on the display 43 as it is. It may be displayed. In this case, the operator handling this ultrasonic flaw detector detects whether or not the defect 4 exists in the subject 1 from the display content of the display 43, and if the defect 4 exists, this defect 4 exists. It is necessary to grasp the position.

  Next, as shown in FIG. 7, the search is made so that the rotation shaft 28 a of the support mechanism 20 a is located on the welded portion 3 of the subject 1 and the position where the defect 4 displayed on the display 43 is present. The touch unit 10 and the support mechanism 20a are set again on the surface of the subject 1.

  Then, the probe unit 10 is rotated at least 180 ° around the rotation shaft 28a of the support mechanism 20a. The CPU 42 of the controller 40a receives the output from the probe unit 10 and the output from the rotation angle sensor 39 via the drive control circuit 41 during the rotation process of the probe unit 10, and associates both outputs with the memory. 44. That is, the CPU 42 stores the output from the probe unit 10 in the memory 44 in association with the rotation angle of the probe unit 10. When the probe unit 10 is rotated clockwise with respect to the scanning direction S, which is the moving direction of the probe unit 10, the angle in the clockwise direction with respect to the scanning direction S is the probe angle. When the probe unit 10 is rotated counterclockwise with the scanning direction S as a reference, the angle in the counterclockwise direction with respect to the scanning direction S is the probe unit. The rotation angle is 10.

  Next, the CPU 42 determines an output with the lowest signal intensity of the ultrasonic echo among the outputs from the probe unit 10 for each rotation angle stored in the memory 44, and is associated with this output. The rotation angle is extracted, and this rotation angle is stored in the memory 44 as the orientation of the defect 4 and displayed on the display 43.

  When the flaw detection cross section P for the probe unit 10 is oriented along the direction in which the defect 4 extends, the signal intensity of the ultrasonic echo indicated by the output from the probe unit 10 at this time is minimized. . For this reason, in this embodiment, the rotation angle when the signal intensity of the ultrasonic echo is the minimum is the direction of the defect 4. Here, the CPU 42 stores the output from the probe unit 10 and the rotation angle of the probe unit 10 in association with each other in the memory 44, and when the signal intensity of the ultrasonic echo is minimum from the memory 44. Although the rotation angle is extracted and used as the direction of the defect 4, the output from the rotating probe unit 10 may be simply displayed on the display 43 as it is. In this case, the handler needs to grasp the rotation angle at the time when the signal intensity of the ultrasonic echo is minimum from the display content of the display 43 as the direction of the defect 4.

  Next, the rotation angle of the probe unit 10 is set to an angle different from the rotation angle when the signal intensity of the ultrasonic echo is minimum, and the rotation shaft 28a of the support mechanism 20a is positioned on the welded portion 3 of the subject 1. The probe unit 10 and the support mechanism 20a are again set on the surface of the subject 1.

  Next, the probe unit 10 and the support mechanism 20a are moved in the scanning direction S.

  The CPU 42 of the controller 40 a receives the output shown in FIG. 8 and the output from the rotation angle sensor 39 from the probe unit 10 through the drive control circuit 41 by the movement of the probe unit 10. In the graph in FIG. 8, the horizontal axis indicates the position of the probe unit 10 in the scanning direction S, and the vertical axis indicates the signal intensity of the ultrasonic echo that is output from the probe unit 10.

  When the CPU 42 receives the output from the probe unit 10 and the output from the rotation angle sensor 39, the apparent length L4 of the defect 4 recognized from the output of the probe unit 10 and the rotation angle sensor. The length L0 of the defect 4 in the virtual plane perpendicular to the flaw detection cross section P, that is, in the plane parallel to the surface of the subject 1, from the rotation angle θ4 that is the output from 39 and the direction θ of the defect 4 Ask for.

Here, for the sake of simplicity, it is assumed that the rotation angle θ4 that is the output from the rotation angle sensor 39 is 90 °. In this case, the CPU 42 substitutes the apparent length L4 of the defect 4 and the orientation θ of the defect 4 into the following (Equation 3) to determine the defect 4 in the virtual plane perpendicular to the flaw detection cross section P. Find the length L0.
L0 = L4 / cosθ (Equation 3)

  If the rotation angle of the probe unit 10 during the first scan is different from the rotation angle when the signal intensity of the ultrasonic echo is minimum, that is, the direction of the defect 4, the CPU 42 performs the first scan. At this time, when the orientation of the defect 4 is obtained using the rotation angle of the probe unit 10 and the apparent length of the defect 4 recognized in the first scan, the length of the defect 4 is immediately obtained. Also good. In this case, the second scan is unnecessary.

  Then, the CPU 42 causes the display 43 to output the obtained length L0 of the defect 4.

  As described above, in the present embodiment, the direction and length of the defect 4 in the subject 1 can be detected. In the present embodiment, the number of the probe units 10 is one, and the transmission probe 11 and the reception probe constituting the probe unit 10 are not phased arrays, and one vibration. Since it is a child-type ultrasonic probe, the apparatus cost can be further reduced as compared with the first embodiment.

  In the present embodiment, since the calculation process by the CPU 42 is not required to detect the direction of the defect 4 in the subject 1, the calculation load on the CPU 42 can be reduced as compared with the first embodiment.

  In the present embodiment, the connecting rod 29 for connecting the transmitting probe 11 and the receiving probe 12 constituting the probe unit 10, the attachment 24, and the rotation center of the probe unit 10. The rotary shaft 28a and the support frame 30a that supports the rotary shaft 28a constitute the support mechanism 20a. The support mechanism 20a is in relation to the flaw detection cross section P for the probe unit 10. Any mechanism may be used as long as it can rotatably support the probe unit 10 in a vertical plane.

  In the first embodiment and the present embodiment, the defect length is obtained by calculation, but may be obtained by drawing. In this case, the CPU 42 develops the diagrams shown in FIGS. 3 and 8 on the memory 44. Specifically, the CPU 42 develops on the memory 44 the output of the probe unit and a line segment parallel to the rotation angle of the probe unit in association with the output of the probe unit. The defect 4 specified in minutes is developed on the memory 44, and the length of the defect 4 is obtained by actual measurement.

  DESCRIPTION OF SYMBOLS 10, 10a, 10b, 10c ... Probe unit, 11 ... Transmitting probe, 12 ... Reception probe, 20 ... Connection support mechanism, 20a ... Support mechanism, 21, 29 ... Connection rod, 28a ... Rotating shaft, 30, 30a ... support frame, 39 ... rotation angle sensor, 40 ... controller, 41 ... drive control circuit, 42 ... CPU, 43 ... display, 44 ... memory

Claims (4)

A probe unit having a transmission probe that transmits ultrasonic waves to a subject and a reception probe that receives ultrasonic waves transmitted by the transmission probe and transmitted through the subject. In the ultrasonic flaw detector,
A surface in the subject passing through the propagation path of the ultrasonic wave received by the receiving probe from the transmitting probe of the probe unit via the subject is defined as a flaw detection cross section, and the probe unit And multi-directional flaw detection means for performing ultrasonic flaw detection at three or more flaw detection cross-sections crossing in different directions from each other in the probe unit,
When the multi-directional flaw detection means scans in one direction along the surface of the subject, and the multi-directional flaw detection means detects a defect in each of the ultrasonic flaw detection at the three or more flaw detection cross sections. Using the apparent intensity of the ultrasonic wave received at each of the ultrasonic flaws in each flaw detection cross section and the apparent defect length determined from the change in the ultrasonic intensity due to the scanning, the three or more flaw detection cross sections A computing means for determining the direction and length of the defect in the direction of the virtual plane perpendicular to both;
An ultrasonic flaw detector characterized by comprising: The ultrasonic flaw detector according to claim 1,
The multidirectional flaw detection means includes three or more probe units such that the three or more probe units and the flaw detection cross-sections in which the probe units perform ultrasonic flaws cross in different directions. A connection support mechanism that connects the two, and among the three or more probe units, the third probe unit has a 90 ° inspection section relative to the first probe unit Intersecting at an angle, and the flaw detection cross section of the second probe unit intersects with the flaw detection end face of the first probe unit at an angle other than 90 °,
When the defect is detected in each of the three or more probe units, the calculation means performs the scanning of the intensity of ultrasonic waves received by the first probe unit and the third probe unit. Using each apparent defect length determined from the accompanying change, any one of the positive end in the scanning direction of the defect and the negative end in the scanning direction of the defect is the third end. The scanning of the intensity of ultrasonic waves received by the first probe unit and the second probe unit is determined by determining whether the probe unit is directed to the transmission probe side with respect to the reception probe. the associated (b) by using the defect length on each apparent determined from the change, the positive side of the end and negative end and out of the defect, as the predetermined end is facing the transmitting transducer side determine the orientation and length of the defect of the virtual plane direction,
An ultrasonic flaw detector characterized by that. The ultrasonic flaw detector according to claim 1,
The multi-directional flaw detection means includes the probe unit, a rotation axis along the flaw detection cross section for the probe unit and about the rotation axis passing through the middle between the transmission probe and the reception probe. A support mechanism for rotatably supporting the probe unit,
The calculation means, when the defect is detected by scanning the multidirectional flaw detection means in one direction along the surface of the subject, the probe unit is rotated at the position of the defect , The direction of the defect in the virtual in-plane direction is obtained by using the rotation angle with the minimum intensity among the ultrasonic wave intensity received at each rotation angle, and the rotation angle different from the rotation angle with the minimum defect length. By scanning the multi-directional flaw detection means having the probe unit set in one direction, the apparent intensity determined from the change accompanying the scanning of the intensity of the ultrasonic wave received by the probe unit . Using the defect length and the direction of the defect, the length of the defect in the virtual in-plane direction is obtained.
An ultrasonic flaw detector characterized by that. The ultrasonic flaw detector according to claim 3,
A rotation angle sensor for detecting a rotation angle of the probe unit around the rotation axis;
The computing means includes a storage unit that stores the intensity of the ultrasonic wave received at each rotation angle received by the probe unit in association with the rotation angle, and a superstructure stored in the storage unit from the storage unit. Extracting the rotation angle associated with the minimum intensity of the sound wave,
An ultrasonic flaw detector characterized by that.

Images