JP6290748B2 - Ultrasonic inspection method and ultrasonic inspection apparatus - Google Patents

Description

  The present invention relates to an ultrasonic inspection method and an ultrasonic inspection apparatus for evaluating a defect range or / and center position in one surface direction and thickness direction of a subject.

  Maintenance of components in a power plant is necessary to maintain normal operation, and the role played by nondestructive inspection technology is highly important. In nuclear power plants in particular, it is important to ensure the integrity of nuclear reactor primary system equipment such as reactor pressure vessels (RPV) and recirculation piping, and ultrasonic flaw testing (UT) is performed on welds that are prone to defects. It has been implemented to detect defects and evaluate the range (size).

  As a conventional ultrasonic inspection method for evaluating a defect range or the like, for example, a tandem method using a transmission probe that transmits ultrasonic waves and a reception probe that receives ultrasonic waves is known. (For example, refer to Patent Document 1). In this tandem method, a transmitting probe and a receiving probe are arranged on one side in the width direction of the weld with respect to a virtual position of a defect (in other words, a position for observing whether or not a defect exists). . Then, ultrasonic waves are transmitted from the transmitting probe so as to reach the virtual position of the defect, and when there is a defect, the ultrasonic wave reflected by the defect is received by the receiving probe. Then, it is possible to evaluate the defect range and the like by detecting the presence of a defect by receiving ultrasonic waves and continuously detecting the position of the defect.

  A transmitting element group (transmission transducer group) composed of a plurality of piezoelectric elements (transducers) that transmit ultrasonic waves and a receiving element group (receiver) composed of a plurality of piezoelectric elements (transducers) that receive ultrasonic waves. A tandem method using a wave transducer group) is also known (see, for example, Patent Document 2).

JP 2002-14082 A JP 2007-163470 A

  However, there are the following problems in the above-described prior art. In the above-described tandem method, for example, in the case of an inspection during or after use of a specimen, it is a defect caused by aging of the specimen and extends in the thickness direction of the specimen (or the boundary direction of the weld). Assume a defect that That is, it is possible to assume the inclination angle of the defect and to assume the propagation path of the ultrasonic wave based on the reflection angle of the ultrasonic wave reflected with high efficiency by the defect. However, for example, in the case of an inspection after the subject is manufactured (before use), a defect occurring at the time of manufacturing the subject is assumed, and the inclination angle of the defect may be unknown. If the inclination angle of the defect is different from the assumed value, an error may occur in the ultrasonic propagation path, and an error may occur in the evaluation of the defect range or / and the center position.

  An object of the present invention is to provide an ultrasonic inspection method and an ultrasonic inspection apparatus capable of evaluating the inclination angle of a defect and improving the evaluation accuracy of the defect range or / and the center position.

  In order to achieve the above object, a representative present invention includes a transmitting element group that transmits ultrasonic waves inside a subject, and an ultrasonic wave reflected by the defect when a defect exists inside the subject. An ultrasonic inspection method using a receiving element group for receiving a sound wave according to a change in a virtual position of the defect and a change in a virtual tilt angle of the defect in one surface direction and thickness direction of the subject Based on each of the analyzed plurality of ultrasonic propagation paths, the ultrasonic transmission position and transmission angle by the transmission element group and the ultrasonic reception position and reception angle by the reception element group are variably controlled, and the ultrasonic propagation is performed. The echo intensity of the defect is acquired from the waveform data of the received ultrasonic wave acquired for each path, and the three-dimensional pattern is formed by the virtual position of the defect and the virtual tilt angle of the defect in one surface direction and thickness direction of the subject. Assuming the case where the echo intensity of the defect is shown in the standard system, the maximum value of the echo intensity is obtained for the distribution of the echo intensity larger than a predetermined threshold, and the defect corresponding to the maximum value of the echo intensity is obtained. Is obtained as an actual inclination angle, an echo intensity distribution corresponding to the actual inclination angle of the defect is extracted, and two-dimensionally formed of the virtual position of the defect in one surface direction and thickness direction of the subject Assuming the case indicated by a coordinate system, the defect in one surface direction and thickness direction of the subject based on the range of the virtual position of the subject corresponding to a distribution of a group of echo intensities greater than a predetermined threshold The actual range or / and the actual center position are obtained.

  According to the present invention, the inclination angle of a defect can be evaluated, and the evaluation accuracy of the defect range or / and the center position can be improved.

It is a block diagram showing the structure of the ultrasonic inspection apparatus in the 1st Embodiment of this invention. It is an axial direction sectional view of a subject showing structures of a transmitting array probe, a receiving array probe, and a probe moving device in a 1st embodiment of the present invention. It is the figure seen from the arrow III direction in FIG. It is the figure seen from the arrow IV direction in FIG. It is a block diagram showing the functional structure of the transmitter / receiver in the 1st Embodiment of this invention with an array probe. It is a figure for demonstrating the analysis of the ultrasonic propagation path in the 1st Embodiment of this invention, and shows the case where the virtual inclination | tilt angle (alpha) = 0 of a defect. It is a figure for demonstrating the change of the ultrasonic propagation path corresponding to the change of the virtual position of the defect in the axial direction of a subject in the 1st Embodiment of this invention. It is a figure for demonstrating the change of the ultrasonic propagation path corresponding to the change of the virtual position of the defect in the thickness direction of a subject in the 1st Embodiment of this invention. It is a figure for demonstrating the change of the ultrasonic propagation path corresponding to the change of the virtual inclination angle of a defect in the 1st Embodiment of this invention. It is a figure showing the reflection efficiency of the transverse wave in the medium boundary in case the incident side medium is steel and the transmission side medium is air. It is a figure showing the specific example of the transmission angle and reception angle of the ultrasonic wave set according to the change of the virtual inclination angle of a defect. It is a figure showing an example of the three-dimensional image in the 1st Embodiment of this invention. It is a figure showing an example of the two-dimensional image in the 1st Embodiment of this invention. It is a flowchart for demonstrating the procedure of the ultrasonic inspection method in the 1st Embodiment of this invention. It is a block diagram showing the structure of the ultrasonic inspection apparatus in the 2nd Embodiment of this invention. It is a figure showing an example of the projection image in the 2nd Embodiment of this invention. It is a figure showing an example of the two-dimensional image in the 1st modification of this invention. It is a block diagram showing the structure of the ultrasonic inspection apparatus in the 2nd modification of this invention. It is a block diagram showing the structure of the ultrasonic inspection apparatus in the 3rd modification of this invention. It is a block diagram showing the structure of the ultrasonic inspection apparatus in the 4th modification of this invention. It is an axial sectional view of a subject showing the structure of an array probe for transmission and reception and a probe moving device in a fourth modification of the present invention. It is a block diagram showing the functional structure of the transmission / reception apparatus in the 4th modification of this invention with an array probe. It is a figure for demonstrating the analysis of the ultrasonic propagation path in the 4th modification of this invention, and shows the case where the virtual inclination | tilt angle (alpha) = 0 of a defect. It is a figure for demonstrating the analysis of the ultrasonic propagation path in the 4th modification of this invention, and shows the case where the virtual inclination | tilt angle (alpha) = 0 of a defect is not. It is a flowchart for demonstrating the procedure of the ultrasonic inspection method in the 4th modification of this invention.

  A first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of an ultrasonic inspection apparatus according to this embodiment. FIG. 2 is a cross-sectional view in the axial direction of the subject showing the structures of the transmitting array probe, the receiving array probe, and the probe moving device in the present embodiment. 3 is a view seen from the direction of arrow III in FIG. 2, and FIG. 4 is a view seen from the direction of arrow IV in FIG. FIG. 5 is a block diagram showing the functional configuration of the transmission / reception apparatus according to this embodiment together with the array probe.

  The ultrasonic inspection apparatus according to the present embodiment is welded to extend in the circumferential direction (vertical direction in FIG. 3 and horizontal direction in FIG. 4) in a cylindrical subject 1 (specifically, for example, the body of a reactor pressure vessel). This is intended to detect and evaluate the defect 3 with the part 2 as an inspection target.

  The ultrasonic inspection apparatus according to this embodiment includes a transmission array probe 4A, a reception array probe 4B, a probe moving device 5, a transmission / reception device 6, a propagation path control unit 7, an input device 8, and a calculation device 9. A storage device 10 and a display device 11. The calculation device 9 includes a propagation path analysis unit 12 and an echo intensity data creation unit 13 as functional configurations. The computing device 9 is composed of a computer or a board on which electronic components are mounted, and the storage device 10 is composed of a hard disk, random access memory (RAM), or the like. The display device 11 is configured by a display or the like, and the input device 8 is configured by a mouse, a keyboard, a touch panel, or the like.

  The probe moving device 5 mechanically moves the transmitting array probe 4A and the receiving array probe 4B along the outer peripheral surface of the subject 1. The probe moving device 5 includes an annular track 14 attached to the outer peripheral side of the subject 1 and a direction along the track 14 (that is, a direction indicated by an arrow D1 in FIGS. 3 and 4). A circumferential movement device 15 provided so as to be movable in the circumferential direction of the subject 1 and a circumferential movement device 15 provided in the circumferential movement device 15 in a direction perpendicular to the trajectory 14 (that is, arrows in FIGS. 2 and 3). An arm moving device 17 that moves the arm 16 in the direction indicated by D2 (in the axial direction of the subject 1), and is movably provided along the arm 16 (that is, in the axial direction of the subject 1). A probe holding device 18A that holds the trusted array probe 4A and a probe holding device 18B that is provided so as to be movable along the arm 16 and hold the receiving array probe 4B are provided.

  The circumferential movement device 15 includes a pinion 20 that meshes with a rack 19 formed on the outer peripheral side of the track 14, a motor (not shown) that rotates the pinion 20, and an encoder (not shown) that detects the amount of rotation of the motor. Z). As the pinion 20 rotates, the circumferential direction moving device 15 moves in the circumferential direction of the subject 1, and accordingly, the transmitting array probe 4 </ b> A and the receiving array probe 4 </ b> B are attached to the subject 1. It moves in the circumferential direction.

  The arm moving device 17 includes a motor (not shown) that moves the arm 16 in a direction perpendicular to the track 14 and an encoder (not shown) that detects the rotation amount of the motor. Then, when the arm 16 moves in the axial direction of the subject 1, the transmitting array probe 4 </ b> A and the receiving array probe 4 </ b> B move in the axial direction of the subject 1. Thus, for example, the center between the transmitting array probe 4A and the receiving array probe 4B in the axial direction of the subject 1 (in other words, one direction on the surface of the subject 1) with reference to the position of the trajectory 14, for example. The position K can be adjusted.

  The probe holding device 18A is attached to the pressing arm 21A, the distal end side of the pressing arm 21A, the probe holder 22A for holding the transmitting array probe 4A, and the pressing arm 21A to the subject 1 side. It has a biasing mechanism (not shown, for example, a spring, a pneumatic cylinder, or a hydraulic cylinder, not shown) that biases and presses the transmitting array probe 4A against the surface of the subject 1. Similarly, the probe holding device 18B is attached to the pressing arm 21B, the distal end side of the pressing arm 21B, the probe holder 22B holding the receiving array probe 4B, and the pressing arm 21B to the subject. And an urging mechanism that urges the receiving array probe 4 </ b> B against the surface of the subject 1.

  The probe holding device 18A includes a pinion 24A that meshes with a rack 23A formed on one side (lower side in FIG. 3, right side in FIG. 4) of the arm 16, and a motor (not shown) that rotates the pinion 24A. And an encoder (not shown) for detecting the rotation amount of the motor. Similarly, the probe holding device 18B includes a pinion 24B that meshes with a rack 23B formed on the other side (upper side in FIG. 3, left side in FIG. 4) of the arm 16, and a motor (not shown) that rotates the pinion 24B. And an encoder (not shown) for detecting the rotation amount of the motor. The probe holding device 18A and the probe holding device 18B are provided so as to face each other with the arm 16 interposed therebetween, and do not interfere with each other.

  For example, if the pinions 24A and 24B rotate in the same direction with the same rotation amount, the probe holding device 18A and the probe holding device 18B move away from each other with the same movement amount. Thereby, the relative distance L between the center position CA of the transmitting array probe 4A and the center position CB of the receiving array probe 4B in the axial direction of the subject 1 is increased. On the other hand, for example, if the pinions 24A and 24B rotate in the opposite direction with the same rotation amount, the probe holding device 18A and the probe holding device 18B move so as to approach each other with the same movement amount. Thereby, the relative distance L between the center position CA of the transmitting array probe 4A and the center position CB of the receiving array probe 4B in the axial direction of the subject 1 is reduced. In this way, the relative distance L between the array probes 4A and 4B can be adjusted while the center position K between the array probes 4A and 4B is fixed. Note that the probe holding device 18A and the probe holding device 18B can move in the same direction or with different movement amounts.

  The transmitting array probe 4A includes a wedge 25A and a plurality of piezoelectric elements (vibrators) 26A arranged on the inclined surface of the wedge 25A. The total number of piezoelectric elements 26A (32 in the figure) of the transmitting array probe 4A is larger than the number of piezoelectric elements (4 in the figure) constituting the transmitting element group 27A that transmits ultrasonic waves. .

  Similarly, the receiving array probe 4B includes a wedge 25B and a plurality of piezoelectric elements (vibrators) 26B arranged on the inclined surface of the wedge 25B. The total number (32 in the drawing) of the piezoelectric elements 26A of the receiving array probe 4B is larger than the number of piezoelectric elements (four in the drawing) constituting the receiving element group 27B that receives the ultrasonic waves. .

  The transmission / reception device 6 includes an input / output control unit 28, a delay time control unit 29, a pulsar 30, a receiver 31, and a data recording unit 32.

  The delay time control unit 29 receives the transmission delay pattern and the reception delay pattern from the propagation path control unit 7 via the input / output control unit 28, controls the pulser 30 based on the transmission delay pattern, and based on the reception delay pattern. Thus, the receiver 31 is controlled.

  The pulsar 30 selects the transmission element group 27A from the piezoelectric elements 26A of the transmission array probe 4A based on the transmission delay pattern, and outputs a drive signal to each piezoelectric element constituting the transmission element group 27A. The output timing of the drive signal (that is, the transmission timing of each piezoelectric element) is controlled. Accordingly, the transmission position and transmission angle of the ultrasonic waves by the transmission element group 27A are variably controlled.

  The receiver 31 selects a receiving element group 27B from the piezoelectric elements 26B of the receiving array probe 4B based on the receiving delay pattern, inputs a waveform signal from each piezoelectric element constituting the receiving element group 27B, The input timing of waveform signals (that is, the reception timing of each piezoelectric element) is controlled and synthesized. Thereby, the ultrasonic reception position and reception angle by the reception element group 27B are variably controlled. Then, predetermined processing (specifically, conversion processing from an analog signal to a digital signal, etc.) is performed on the synthesized waveform signal to acquire waveform data and record it in the data recording unit 32. This waveform data is discrete data consisting of the relationship between the path length and intensity (wave height value) of an ultrasonic wave.

  The propagation path control unit 7 controls the probe moving device 5 and the transmitting / receiving device 6 in cooperation with each other. Therefore, the detection information of the encoder is input from the probe moving device 5 to grasp the current circumferential position of the circumferential moving device 15 (in other words, the circumferential position of the array probes 4A and 4B), The center position K and the relative distance L between the current array probes 4A and 4B are grasped. In addition, control information is input from the transmission / reception device 6 to grasp the current transmission delay pattern and reception delay pattern.

  Then, a control command is output to the probe moving device 5, and the circumferential movement device 15 is moved in the circumferential direction of the subject 1 at a predetermined pitch, and the circumferential position thereof is variably controlled. Thereby, the transmission position and reception position of the ultrasonic wave in the circumferential direction of the subject 1 are variably controlled. Further, based on the index data 33 of the center position between the probes stored in advance in the storage device 10, a control command is output to the probe moving device 5, and the center position K between the array probes 4A and 4B is determined. Variable control. Thereby, the ultrasonic transmission position and reception position in the axial direction of the subject 1 are variably controlled. Further, based on the index data 34 of the relative distance between the probes stored in advance in the storage device 10, a control command is output to the probe moving device 5, and the relative distance L between the array probes 4A and 4B is determined. Variable control. Thereby, the ultrasonic transmission position and reception position in the axial direction of the subject 1 are variably controlled. Further, based on the delay pattern index data 35 stored in advance in the storage device 10, the transmission delay pattern and the reception delay pattern are output to the transmission / reception device 6. As a result, the ultrasonic transmission position and reception position in the axial direction of the subject 1 are variably controlled, and the ultrasonic transmission angle and reception angle are variably controlled.

  The propagation path analysis unit 12 of the calculation device 9 preliminarily creates the above-described index data 33, 34, and 35 based on conditions such as the dimensions and sound speed of the subject 1 input by the input device 8. It analyzes the path through which sound waves propagate efficiently. Here, as one of the features of the present embodiment, not only the change of the virtual position of the defect in the axial direction and the thickness direction of the subject 1 (in other words, the position for observing whether or not the defect exists) The propagation path of the ultrasonic wave is analyzed according to the change in the virtual inclination angle of the defect.

Specifically, first, for example, as shown in FIG. 6, a case is assumed in which the virtual tilt angle α of the defect 3 is 0 (that is, the defect 3 extends in the thickness direction of the subject 1). Then, the propagation path of the ultrasonic wave is analyzed. The circumferential direction of the subject 1 is the X axis, the axial direction of the subject 1 is the Y axis (specifically, for example, the position of the trajectory 14 is Y = 0), and the thickness direction of the subject 1 is the Z axis (detailed). Sets the inspection range S and sets the virtual position P (x _p , y _p , z _p ) of the defect 3 in the inspection range S, assuming that the position of the outer peripheral surface of the subject 1 is Z = 0). Then, for example, after the transverse wave mode ultrasonic wave transmitted from the transmitting element group 27A of the transmitting probe 4A to the subject 1 via the wedge 25A is reflected once on the inner peripheral surface of the subject 1, the defect 3 Assume that the virtual position P is reached. Further, it is assumed that the ultrasonic wave reflected at the virtual position P of the defect 3 is received by the receiving element group 27B of the receiving probe 4B via the wedge 25B. According to such an ultrasonic propagation path F, the center position K and the relative distance L between the array probes 4A and 4B can be calculated using the following equation (1).

Here, t is the thickness of the subject 1. Further, θ _t is an ultrasonic transmission angle (refraction angle) by the transmission element group 27A, and θ _r is an ultrasonic reception angle (refraction angle) by the reception element group 27B. In the present embodiment, when the virtual tilt angle α = 0 of the defect 3 is set, the transmission angle θ _t = the reception angle θ _r = the reference refraction angle θ ₀ (specifically, for example, 45 degrees). Further, when a virtual tilt angle alpha = 0 defects 3, the transmission position E _t of the ultrasonic waves by transmission element group 27A and the center position CA of the transmitting array probe 4A, by the receiving element group 27B of the ultrasonic The reception position _Er is set as the center position CB of the reception array probe 4B.

As is clear from the above equation (1), the center position K between the array probes 4A and 4B corresponds to the virtual position yp of the defect 3 in the axial direction of the subject 1. That is, as shown in FIG. 7 (a), when assuming yp = 0, may be controlled array probe 4A, the center position K = _{K 1} between 4B. Further, for example, as shown in FIG. 7B, when yp = yp_max is assumed, the center position between the array probes 4A and 4B may be controlled to K = K ₂ (where K ₂ > K ₁ ). . Therefore, the center position K between the array probes 4A and 4B is sequentially calculated according to the change of the virtual position yp of the defect 3, and these are stored in the storage device 10 as the index data 33.

Further, as is clear from the above equation (1), the relative distance L between the array probes 4A and 4B corresponds to the virtual position zp of the defect 3 in the thickness direction of the subject 1. That is, as shown in FIG. 8 (a), the case of assuming the zp ≒ 0, may be controlled array probe 4A, the relative distance L = _{L 1} between 4B. Further, for example, as shown in FIG. 8B, when zp≈zp_max is assumed, the relative distance between the array probes 4A and 4B may be controlled to L = L ₂ (where L ₂ <L ₁ ). . Therefore, the relative distance L between the array probes 4A and 4B is sequentially calculated according to the change of the virtual position zp of the defect 3, and these are stored in the storage device 10 as index data 34.

Next, assuming that the virtual inclination angle α of the defect 3 is not 0, the propagation path of the ultrasonic wave is analyzed. In this case, the case of alpha = 0, together with changing the transmission position E _t and the transmission angle theta _t of the ultrasonic waves by transmission element group 27A, the receiving position E _r and reception angle of the ultrasonic wave by the receiving element group 27B θ _r must be changed. More specifically, as shown in FIG. 9 (a), α = α 1 ( where, alpha _1> 0) if it is, the transmission position _{E t} of the ultrasonic waves by transmission element group 27A, a virtual defect 3 The shift amount is shifted by ΔT so as to approach the position P. Further, the ultrasonic reception position _Er by the reception element group 27B is shifted by a shift amount ΔR so as to be away from the virtual position P of the defect 3. In addition, the transmission angle θ _{t of the} ultrasonic wave is corrected by a correction value β _t (where α> 0, β _t <0). Also, the ultrasonic reception angle θ _r is corrected by a correction value β _r (where α _r > 0 when α> 0).

For example, as shown in FIG. 9 (b), α = α 2 ( where, alpha ₂ <0) if it is, the transmission position _{E t} of the ultrasonic waves by transmission element group 27A, the virtual position P of the defect 3 Shift by a shift amount ΔT to keep away. In addition, the ultrasonic reception position _Er by the reception element group 27B is shifted by the shift amount ΔR so as to approach the virtual position P of the defect 3. Further, the transmission angle θ _{t of the} ultrasonic wave is corrected by a correction value β _t (provided that β _t > 0 when α <0). Also, the ultrasonic reception angle θ _r is corrected by a correction value β _r (where α _r <0, β _r <0).

Here, in order to increase the reflection efficiency of the ultrasonic wave in the defect 3, it is necessary to equalize the incident angles phi _t and the reflection angle phi _r ultrasound to defects 3. Therefore, it is necessary to set the ultrasonic transmission angle θ _t and the reception angle θ _r so as to satisfy the following expression (2).

As shown in FIG. 10, when the incident angle of the transverse wave is 35 degrees or more, the reflection efficiency of the transverse wave becomes 1.0 (specifically, the energy distribution ratio from the incident incident wave to the reflected wave of the transverse wave). Becomes 1.0 at the maximum, and the energy distribution ratio to the longitudinal reflected wave becomes 0 at the minimum). Therefore, the incident angle of the ultrasonic wave with respect to the inner peripheral surface of the subject 1, that is, the transmission angle θ _{t of the} ultrasonic wave by the transmitting element group 27A is set to 35 degrees or more, and the incident angle φ _{t of the} ultrasonic wave to the defect 3 is set to 35 degrees. The above is preferable. As a specific example of the ultrasonic transmission angle θ _t and the reception angle θ _r satisfying this condition and the above equation (2), the following equation (3) can be considered.

As another specific example, the following formula (4) can be considered. FIG. 11 shows the relationship between the virtual tilt angle α of the defect that satisfies the equation (4), the ultrasonic transmission angle θ _t, and the reception angle θ _r .

By setting the ultrasound transmission angle theta _t and the receiving angle theta _r of as described above, the shift amount ΔR of shift amount ΔT and receiving position E _r of the ultrasonic transmission position E _t, Equation (5) below Can be used to calculate.

Then, according to the change of the virtual inclination angle α of the defect, a transmission delay pattern corresponding to the ultrasonic transmission position E _t and the transmission angle θ _t is generated, and at the ultrasonic reception position _Er and the reception angle θ _r . Corresponding reception delay patterns are generated, and stored as index data 35 in the storage device 10.

  Returning to FIG. 1 and FIG. 5 described above, the input / output control unit 28 of the transmission / reception device 6 reads waveform data from the data recording unit 32 and controls information (details, for example, in the circumferential direction) as acquisition conditions of the waveform data The position of the moving device 14, the center position K and the relative distance L between the array probes 4L and 4B, the transmission delay pattern and the reception delay pattern) are input from the propagation path control unit 7 and the like, and are associated with each other to store them. 10 and stored in the storage device 10.

The echo intensity data creation unit 13 of the calculation device 9 reads the waveform data 36 stored in the storage device 10 and the control information associated therewith. Then, the path of the defect is acquired based on the propagation path of the ultrasonic wave corresponding to the control information with the help of the propagation path analysis unit 12, and the echo intensity of the defect is extracted from the waveform data 36. Further, the virtual position P (x _p , y _p , z _p ) of the defect and the virtual inclination angle α are acquired with the help of the propagation path analysis unit 12 and associated with the above-described echo intensity. In this way, echo intensity data 37 is created and stored in the storage device 10.

  The display device 11 includes a three-dimensional image display unit 38, an actual inclination angle input unit 39, and a two-dimensional image display unit 40 as functional configurations.

  The three-dimensional image display unit 38 generates, for example, a three-dimensional image 41 as shown in FIG. 12 for each virtual position xp of the defect in the circumferential direction of the subject 1 based on the echo intensity data 37 stored in the storage device 10. Is displayed. This three-dimensional image 41 shows the corresponding echo intensity in a three-dimensional coordinate system composed of the virtual positions yp, zp of the defect and the virtual inclination angle α in the axial direction and the thickness direction of the subject 1. Specifically, the level of the echo intensity is determined based on the magnitude relationship with a plurality of threshold values, and the echo intensity is indicated by a color tone corresponding to the level. The three-dimensional image 41 includes a coordinate selection field 42 for selecting an arbitrary coordinate (ypi, zpi, αi) by moving the cursor, inputting a numerical value, and the like, and an arbitrary coordinate (ypi, zpi, αi) selected. And an echo intensity display field 43 for displaying echo intensity (numerical value). Therefore, the inspector can confirm a distribution of a group of echo intensities larger than a predetermined threshold on the three-dimensional image 41. Further, the maximum value of the echo intensity is searched for the distribution, and the virtual inclination angle α corresponding to the maximum value of the echo intensity can be read as the actual inclination angle.

  The actual inclination angle input unit 39 is for an inspector to input an actual inclination angle. Specifically, for example, the actual inclination angle is displayed by operating an input button (not shown) or the like while displaying the actual inclination angle in the coordinate selection field 42 of the three-dimensional image 41. .

  The two-dimensional image display unit 40 extracts the echo intensity distribution corresponding to the actual tilt angle input by the actual tilt angle input unit 39, and generates a two-dimensional image 44 as shown in FIG. Is displayed. The two-dimensional image 44 shows the corresponding echo intensity in the two-dimensional coordinate system composed of the virtual positions yp and zp of the defect in the axial direction and the thickness direction of the subject 1 (that is, the two-dimensional image 44 is This corresponds to a flaw detection image of the YZ cross section). Specifically, the level of the echo intensity is determined based on the magnitude relationship with a plurality of threshold values, and the echo intensity is indicated by a color tone corresponding to the level. Therefore, the examiner can confirm a distribution of a group of echo intensities larger than a predetermined threshold on the two-dimensional image 44. Further, based on the range of the virtual position yp of the defect 3 corresponding to the distribution, it is possible to read the real range (ya to yb) or / and the real center position (yc) of the defect 3 in the axial direction of the subject 1. is there. Further, based on the range of the virtual position zp of the defect 3 corresponding to the distribution, the real range (za to zb) or / and the real center position (zc) of the defect 3 in the thickness direction of the subject 1 can be read. It is.

  In the above, the probe moving device 5 includes a transmission position control unit and a reception element group that variably control the transmission position of the ultrasonic wave by mechanically moving the transmission element group described in the claims. A reception position control unit that mechanically moves and variably controls the reception position of the ultrasonic wave is configured. Further, the transmission / reception device 6 includes a transmission position control unit that electronically selects a transmission element group and variably controls a transmission position of ultrasonic waves, and transmission timings of the elements that constitute the transmission element group. Control unit for variably controlling the transmission angle of the ultrasonic wave by controlling the reception position control unit for variably controlling the reception position of the ultrasonic wave by electronically selecting the reception element group, and each component constituting the reception element group A reception angle control unit is configured to variably control the reception angle of the ultrasonic wave by controlling the reception timing of the element.

  Next, an ultrasonic inspection method using the ultrasonic inspection apparatus of this embodiment will be described. FIG. 14 is a flowchart for explaining the procedure of the ultrasonic inspection method according to this embodiment.

  First, in step 100, the propagation path control unit 7 controls the probe moving device 5 to move the circumferential direction moving device 15 so as to correspond to the first defect virtual position xp. Thereafter, the process proceeds to step 110, and the arm 16 is moved by the arm moving device 17 so as to correspond to the first defect virtual position yp, and the center position K between the array probes 4A and 4B is adjusted. Thereafter, the process proceeds to step 120, and the probe holding devices 18A and 18B are moved so as to correspond to the first defect virtual position zp, and the relative distance L between the array probes 4A and 4B is adjusted.

  Then, the process proceeds to step 130, where the transmission / reception device 6 performs transmission / reception of ultrasonic waves (that is, flaw detection) using the transmission delay pattern and the reception delay pattern corresponding to the first defect virtual inclination angle α, and the received ultrasonic waves The waveform data 36 is stored in the storage device 10. Thereafter, the process proceeds to step 140, where the echo intensity data creation unit 13 of the calculation device 9 creates echo intensity data 37 from the waveform data 36 and stores it in the storage device 10.

  Thereafter, the process proceeds to step 150, and whether or not the scanning of the delay pattern is completed (that is, whether or not flaw detection is performed using the transmission delay pattern and the reception delay pattern corresponding to the g-th defect virtual inclination angle α). At the beginning of the determination, since the determination of step 150 is not satisfied, the above-described steps 130 and 140 are repeated. That is, flaw detection using a delay pattern corresponding to the second, third,..., G-th defect virtual inclination angle α is performed, and echo intensity data 37 is created and stored.

  Thereafter, the determination in step 150 is satisfied, and the process proceeds to step 160, where scanning of the relative distance L is completed (that is, whether the relative distance L corresponding to the h-th defect virtual position zp is adjusted). Determine. At first, since the determination of step 160 is not satisfied, the above-described steps 120 to 150 are repeated. That is, after adjusting the relative distance L corresponding to the second, third,..., H-th defect virtual position zp, steps 130 to 150 described above are repeated.

  Thereafter, the determination in step 160 is satisfied, and the process proceeds to step 170, in which whether or not the scanning of the center position K has been completed (that is, whether or not the center position K corresponding to the i-th defect virtual position yp has been adjusted). Determine. At first, since the determination in step 170 is not satisfied, steps 110 to 160 described above are repeated. That is, after adjusting to the center position K corresponding to the second, third,... I-th defect virtual position yp, steps 120 to 160 described above are repeated. Thereafter, the determination at Step 170 is satisfied, and the routine goes to Step 180.

  In step 180, the 3D image display unit 38 of the display device 11 generates and displays a 3D image 41 based on the echo intensity data 37. Then, the process proceeds to step 190, where the inspector obtains the maximum value of the echo intensity for the distribution of the echo intensity larger than the predetermined threshold on the three-dimensional image 41, and the defect corresponding to the maximum value of the echo intensity. Is obtained as an actual inclination angle. Thereafter, the actual inclination angle of the defect is input.

  Then, the process proceeds to step 200, where the two-dimensional image display unit 40 of the display device 11 extracts the echo intensity distribution corresponding to the input defect actual inclination angle, and generates and displays the two-dimensional image 44 based on this. . Then, the process proceeds to step 210, where the inspector determines the axial direction of the subject 1 based on the range of the defect virtual positions yp and zp corresponding to the distribution of the cluster of echo intensity larger than the predetermined threshold on the two-dimensional image 44. The actual range or / and the actual center position of the defect 3 in each of the thickness directions are obtained.

  Then, the process proceeds to step 220 to determine whether or not the movement of the circumferential movement device 15 is completed (that is, whether or not the movement to the position corresponding to the j-th defect virtual position xp). Since the determination in step 220 is not satisfied, steps 100 to 210 described above are repeated. That is, after moving to a position corresponding to the second, third,..., Jth defect virtual position xp, the above-described steps 110 to 210 are repeated. Thereafter, the determination in step 220 is satisfied, and the inspection ends.

  As described above, in this embodiment, the inclination angle of the defect 3 can be evaluated. Further, since the range or / and center position of the defect 3 in each of the axial direction and the thickness direction of the subject 1 is evaluated based on the inclination angle, the evaluation accuracy of the range or / and center position of the defect 3 is improved. Can do.

  A second embodiment of the present invention will be described with reference to FIGS. 15 and 16.

  FIG. 15 is a block diagram showing the configuration of the ultrasonic inspection apparatus according to this embodiment. FIG. 16 is a diagram illustrating an example of a projection image in the present embodiment. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The display device 11 according to the present embodiment includes a projection image display unit 45 instead of the three-dimensional image display unit 36 described above.

  The projection image display unit 45 generates and displays a projection image 46 for each virtual position xp of the defect in the circumferential direction of the subject 1 based on the echo intensity data 37 stored in the storage device 10. More specifically, the projection image display unit 45 obtains a maximum value for the echo intensity of a defect that differs depending on the virtual position zp of the defect under the same conditions of the virtual position yp of the defect and the virtual inclination angle α. Is generated and displayed in a two-dimensional coordinate system composed of the virtual position yp of the defect and the virtual inclination angle α. For example, as shown in FIG. 16, the projected image 46 includes a coordinate selection field 47 for selecting arbitrary coordinates (ypi, αi) by moving a cursor, inputting numerical values, and the like, and arbitrary selected coordinates (ypi, αi). And an echo intensity display field 48 for displaying the echo intensity (numerical value). Therefore, the inspector can confirm a distribution of a group of echo intensities larger than a predetermined threshold on the projection image 46. Further, the maximum value of the echo intensity is searched for the distribution, and the virtual inclination angle α corresponding to the maximum value of the echo intensity can be read as the actual inclination angle.

  Also in the present embodiment configured as described above, the inclination angle of the defect can be evaluated as in the first embodiment, and the evaluation accuracy of the defect range or / and the center position can be improved.

  In the second embodiment, the projection image display unit 45 has a maximum value for the echo intensity of a defect that differs depending on the virtual position zp of the defect under the same conditions of the virtual position yp of the defect and the virtual inclination angle α. However, the present invention is not limited to this example, and the projection image 46 is generated and displayed in the two-dimensional coordinate system including the virtual value yp of the defect and the virtual inclination angle α. Modifications can be made without departing from the spirit and technical idea of the present invention. That is, under the same condition of the virtual position zp of the defect and the virtual inclination angle α, a maximum value is obtained for the echo intensity of a different defect depending on the virtual position yp of the defect, and the maximum value of this echo intensity is determined as the virtual position zp of the defect In addition, a projection image indicated by a two-dimensional coordinate system including the virtual inclination angle α may be generated and displayed. In this case, the same effect as described above can be obtained.

  In the first and second embodiments, the two-dimensional image display unit 40 has been described by way of example of generating and displaying a two-dimensional image 44 as shown in FIG. 13, for example. However, the present invention is not limited to this. Modifications can be made without departing from the spirit and technical idea of the present invention. That is, for example, a two-dimensional image 40A as shown in FIG. 17 may be generated and displayed (first modification). This two-dimensional image 40A has a cursor 49 for selecting an arbitrary defect virtual position ypi, and the relationship between the defect virtual position zp and the echo intensity at the selected arbitrary defect virtual position yip (echo intensity distribution in the Z direction). Is equivalent). Thereby, it is possible to further improve the evaluation accuracy of the defect range or / and the center position determined by the inspector.

  In the first embodiment, the case where the inspector has the actual inclination angle input unit 39 for obtaining and inputting the actual inclination angle of the defect from the three-dimensional image 41 has been described as an example. Modifications can be made without departing from the spirit and technical idea of the present invention. That is, for example, as in the second modification shown in FIG. 18, an actual inclination angle calculation unit 50 (first calculation unit) may be provided instead of the actual inclination angle input unit 39. The actual inclination angle calculation unit 50 calculates the maximum value of the echo intensity in the distribution of the echo intensity larger than the predetermined threshold on the three-dimensional image 41, and calculates the virtual value of the defect corresponding to the maximum value of the echo intensity. Calculation processing is performed using the inclination angle α as the actual inclination angle. Even in such a modification, the same effect as described above can be obtained.

  Further, for example, as in a third modification shown in FIG. 19, an actual range / actual center position calculation unit 51 (second calculation unit) may be included. The real range / real center position calculation unit 51 determines the axis of the subject 1 based on the range of the virtual positions yp, zp of the defect corresponding to the distribution of the echo intensity larger than a predetermined threshold on the two-dimensional image 44. The actual range or / and the actual center position of the defect 3 in each of the direction and the thickness direction are calculated. Even in such a modification, the same effect as described above can be obtained.

  In the first embodiment and the like, the echo intensity data 37 of the storage device 10 associates the virtual position xp, yp, zp of the defect and the virtual inclination angle α with the echo intensity. Although the case where the three-dimensional image 41 in the yp-zp-α coordinate system and the two-dimensional image 44 in the yp-zp coordinate system are generated and displayed has been described as an example, the present invention is not limited thereto. That is, the echo intensity data 37 of the storage device 10 includes the position of the circumferential movement device 15, the intermediate position between the array probes 4A and 4B, the relative distance L, the transmission delay pattern and the reception delay pattern with respect to the echo intensity. The display device may generate and display a three-dimensional image of the KL-α coordinate system. Then, a maximum value of the echo intensity is obtained for a distribution of a set of echo intensities larger than a predetermined threshold on the three-dimensional image of the KL-α coordinate system, and a defect virtual corresponding to the maximum value of the echo intensity is obtained. The inclination angle may be obtained as the actual inclination angle. Thereafter, a distribution of echo intensity corresponding to the actual inclination angle of the defect may be extracted, and a two-dimensional image of the KL coordinate system may be generated and displayed. Then, based on the range of the intermediate position K corresponding to a distribution of a set of echo intensities larger than a predetermined threshold on the two-dimensional image in the KL coordinate system, the actual range of defects in the axial direction of the subject 1 and / or The actual center position may be obtained. Further, based on the range of the relative distance L corresponding to a distribution of a group of echo intensities larger than a predetermined threshold on the two-dimensional image of the KL coordinate system, the actual range of defects in the thickness direction of the subject 1 or / In addition, the actual center position may be obtained. In these cases, the same effect as described above can be obtained.

  In the second and third modified examples, the case where the 3D image display unit 38 that generates and displays the 3D image 41 has been described as an example. However, the present invention is not limited thereto, and the 3D image display unit is not limited thereto. 38 may not be included. That is, the actual tilt angle calculation unit 50 calculates the echo intensity of the defect in the three-dimensional coordinate system including the virtual position yp, zp of the defect and the virtual tilt angle α as a process for the echo intensity data 37 stored in the storage device 10. Assuming that the maximum value of the echo intensity in the cluster distribution of echo intensity larger than a predetermined threshold on this three-dimensional coordinate system is calculated, the virtual inclination angle of the defect corresponding to the maximum value of this echo intensity is calculated. The arithmetic processing may be performed with α as the actual inclination angle. In this case, the same effect as described above can be obtained.

  In the third modified example, the case where the two-dimensional image display unit 40 that generates and displays the two-dimensional image 44 (or 44A) has been described as an example. The portion 40 may not be provided. That is, the actual range / center position calculation unit 51 performs an echo intensity distribution corresponding to the actual inclination angle of the defect calculated by the actual inclination angle calculation unit 50 as a process for the echo intensity data 37 stored in the storage device 10. Assuming a case where the defect is extracted and indicated by a two-dimensional coordinate system composed of the virtual positions yp and zp of the defect, the defect virtual corresponding to a distribution of a group of echo intensities larger than a predetermined threshold on the two-dimensional coordinate system is assumed. Based on the position range, the actual center position or the actual range of the defect in each of the axial direction and the thickness direction of the subject 1 may be calculated. In this case, the same effect as described above can be obtained.

  Further, in the first embodiment and the like, for example, as shown in FIG. 2 and the like, the transmission probe 4A is arranged farther from the virtual position P of the defect 3, and the virtual position P of the defect 3 is arranged. However, the present invention is not limited to this, and the transmission probe 4A is disposed closer to the virtual position P of the defect 3, and the defect is detected. The receiving probe 4B may be arranged farther away from the virtual position P. In this case, the same effect as described above can be obtained.

  In the first embodiment and the like, a transmission probe 4A having a plurality of elements 26A including a transmission element group 27A and a reception probe 4B having a plurality of elements 26B having a reception element group 27B. However, the present invention is not limited to this, and modifications can be made without departing from the spirit and technical idea of the present invention. That is, for example, a transmission / reception probe having a plurality of elements including a transmission element group and a reception element group may be provided. Such a fourth modification will be described in detail.

  FIG. 20 is a block diagram illustrating a configuration of an ultrasonic inspection apparatus according to this modification. FIG. 21 is a cross-sectional view in the axial direction of the subject showing the structure of the transmitting / receiving probe and the probe moving device in the present modification. FIG. 22 is a block diagram showing the functional configuration of the transmission / reception apparatus according to this modification together with the array probe. In this modification, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The ultrasonic inspection apparatus according to this modification includes a transmission / reception array probe 52, a probe moving apparatus 5A, a transmission / reception apparatus 6A, a propagation path control unit 7A, an input apparatus 8, a calculation apparatus 9, a storage apparatus 10, and a display apparatus. 11 is provided.

  The probe moving device 5A mechanically moves the transmitting / receiving array probe 52 along the outer peripheral surface of the subject 1. The probe moving device 5A includes an annular track 14 attached to the outer peripheral side of the subject 1 and the track 14 along the track 14 (that is, the circumferential direction of the subject 1). And a circumferential movement device 15 movably provided, and a circumferential movement device 15 provided in the circumferential movement device 15 in a direction perpendicular to the track 14 (that is, in the direction indicated by the arrow D2 in FIG. An arm moving device 17 that moves the arm 16A (in the axial direction of the sample 1) and a probe holding device 18 that is provided on the arm 16A and holds the transmitting / receiving array probe 52 are provided.

  The probe holding device 18 is attached to the pressing arm 21, the distal end side of the pressing arm 21, the probe holder 22 holding the transmitting / receiving array probe 52, and the pressing arm 21 to the subject 1 side. It has a biasing mechanism (not shown, for example, a spring, a pneumatic cylinder, or a hydraulic cylinder, not shown) that biases and presses the transmitting / receiving array probe 52 against the surface of the subject 1.

  The transmission / reception array probe 52 includes a wedge 25 and a plurality of piezoelectric elements (vibrators) 26 arranged on an inclined surface of the wedge 25. The total number of piezoelectric elements 26 of the transmitting / receiving array probe 52 is larger than the number of piezoelectric elements constituting the transmitting element group 27A and the receiving element group 27B.

  The pulsar 30 of the transmission / reception device 6A selects the transmission element group 27A from the piezoelectric elements 26 of the transmission / reception array probe 52 based on the transmission delay pattern, and outputs a drive signal to each piezoelectric element constituting the transmission element group 27A. At the same time, the output timing of each drive signal (that is, the transmission timing of each piezoelectric element) is controlled. Accordingly, the transmission position and transmission angle of the ultrasonic waves by the transmission element group 27A are variably controlled.

  The receiver 31 of the transmission / reception device 6A selects the reception element group 27B from the piezoelectric elements 26 of the transmission / reception array probe 52 based on the reception delay pattern, and inputs a waveform signal from each piezoelectric element constituting the reception element group 27B. At the same time, the input timing of each waveform signal (that is, the reception timing of each piezoelectric element) is controlled and synthesized. Thereby, the ultrasonic reception position and reception angle by the reception element group 27B are variably controlled.

  The propagation path controller 7A outputs a control command to the probe moving device 5A, moves the circumferential movement device 15 at a predetermined pitch in the circumferential direction of the subject 1, and variably controls the circumferential position. . Thereby, the transmission position and reception position of the ultrasonic wave in the circumferential direction of the subject 1 are variably controlled. Further, based on the probe position index data 53 stored in advance in the storage device 10, a control command is output to the probe moving device 5A to variably control the center position M of the transmitting / receiving array probe 52. . Thereby, the ultrasonic transmission position and reception position in the axial direction of the subject 1 are variably controlled. Further, based on the delay pattern index data 54 stored in advance in the storage device 10, the transmission delay pattern and the reception delay pattern are output to the transmission / reception device 6. As a result, the ultrasonic transmission position and reception position in the axial direction of the subject 1 are variably controlled, and the ultrasonic transmission angle and reception angle are variably controlled.

  The propagation path analysis unit 12 of the calculation device 9 generates ultrasonic data based on conditions such as the dimensions and sound speed of the subject 1 input by the input device 8 in advance in order to create the index data 53 and 54 described above. Analyze efficient propagation paths.

  Specifically, first, as shown in FIG. 23, for example, a case is assumed in which the virtual tilt angle α = 0 of the defect 3 (that is, the defect 3 extends in the thickness direction of the subject 1). Then, the propagation path of the ultrasonic wave is analyzed. According to the ultrasonic wave propagation path F, the center position M of the transmission / reception array probe 52 can be calculated in the same manner as the center position K between the array probes 4A and 4B described above. That is, the center position M of the transmission / reception array probe 52 corresponds to the virtual position yp of the defect 3 in the axial direction of the subject 1. Therefore, the center position M of the transmission / reception array probe 52 is sequentially calculated according to the change in the virtual position yp of the defect 3 and stored in the storage device 10 as the index data 53.

Further, when a virtual tilt angle alpha = 0, the transmission position E _t of the ultrasonic waves by transmission element group 27A and the position GA of the array probe 52, a receiving position E _r of the ultrasonic waves by the receiving element group 27B array When the probe position GB is used, the distance N between GA and GB (this is referred to as the relative reference distance between the element groups) is the same as the relative distance L between the array probes 4A and 4B described above. Can be computed. That is, the relative distance N between the element groups corresponds to the virtual position zp of the defect 3 in the thickness direction of the subject 1.

Next, for example, as illustrated in FIG. 24, the propagation path of the ultrasonic wave is analyzed on the assumption that the virtual inclination angle α of the defect 3 is not 0. As in the first embodiment, the correction value β _{t of the} ultrasonic transmission angle θ _{t and} the correction value β _r of the reception angle θ _r are calculated according to the change in the virtual tilt angle α of the defect. calculates a shift amount ΔR of shift amount ΔT and receiving position E _r of the ultrasonic transmission position E _t.

Then, in response to changes in the virtual position zp and virtual inclination angle α of the defect, to generate a transmission delay pattern corresponding to the ultrasonic transmission position E _t and the transmission angle theta _t of ultrasonic reception position E _r and reception A reception delay pattern corresponding to the angle θ _r is generated and stored as index data 54 in the storage device 10.

  Next, an ultrasonic inspection method using the ultrasonic inspection apparatus of this modification will be described. FIG. 25 is a flowchart for explaining the procedure of the ultrasonic inspection method according to this modification. In FIG. 25, steps 230 to 270 are used instead of steps 110 to 170 in FIG. Therefore, only steps 230 to 270 will be described, and description of other steps will be omitted.

  In step 240, the transmission / reception device 6A transmits / receives ultrasonic waves using the transmission delay pattern and the reception delay pattern corresponding to the first defect virtual position zp and corresponding to the first defect virtual inclination angle α (that is, flaw detection). ) To store the waveform data 36 of the received ultrasonic wave in the storage device 10. Thereafter, the process proceeds to step 250, where the echo intensity data creation unit 13 of the calculation device 9 creates echo intensity data 37 from the waveform data 36 and stores it in the storage device 10.

  Thereafter, the process proceeds to step 260, and whether or not the delay pattern scan is completed (that is, the transmission delay pattern and the reception delay pattern corresponding to the h-th defect virtual position zp and corresponding to the g-th defect virtual inclination angle α). In the beginning, the determination of step 260 is not satisfied, and thus the above-described steps 240 and 250 are repeated. That is, flaw detection is performed using a delay pattern corresponding to the first defect virtual position zp and corresponding to the second, third,..., G-th defect virtual inclination angle α, and echo intensity data 37 is created. And remember. Further, flaw detection is performed using a delay pattern corresponding to the second defect virtual position zp and corresponding to the first, second, third,... Is created and stored. ... flaw detection using a delay pattern corresponding to the h-th defect virtual position zp and corresponding to the first, second, third,. Create and store each.

  Thereafter, the determination in step 260 is satisfied, and the process proceeds to step 270, where whether or not the scanning of the center position M is completed (that is, whether or not the center position M corresponding to the i-th defect virtual position yp is adjusted). Determine. At first, since the determination at step 270 is not satisfied, the above-described steps 230 to 260 are repeated. That is, after adjusting to the center position K corresponding to the second, third,... I-th defect virtual position yp, steps 240 to 260 described above are repeated. Thereafter, the determination at Step 270 is satisfied, and the routine goes to Step 180.

  Also in this modified example as described above, the inclination angle of the defect can be evaluated, and the evaluation accuracy of the defect range or center position can be improved, as in the first embodiment.

  In the first embodiment and the like, the case where the array probes 4A and 4B have the wedges 25A and 25B is taken as an example. In the fourth modification, the array probe 52 has the wedge 25. Although the case has been described as an example, the present invention is not limited to this. That is, a wedge may not be provided, and a plurality of piezoelectric elements 26 may be arranged along the surface of the subject 1. In this case, the same effect as described above can be obtained.

  In the first embodiment and the like, the transmission probe 4A having more piezoelectric elements 26A than the number of piezoelectric elements constituting the transmitting element group 27A and the number of piezoelectric elements constituting the receiving element group 27B are used. When the receiving probe 4B having a large number of piezoelectric elements 26B is provided (in other words, the transmitting element group 27A is changed from the piezoelectric elements 26A of the transmitting array probe 4A according to the change in the virtual tilt angle α of the defect). The ultrasonic transmission position is variably controlled by electronic selection, the transmission timing of each piezoelectric element constituting the transmission element group 27A is controlled to variably control the ultrasonic transmission angle, and the receiving array probe 4B. The receiving element group 27B is electronically selected from the piezoelectric elements 26B and the ultrasonic receiving position is variably controlled, and the receiving timing of each piezoelectric element constituting the receiving element group 27B is controlled to change the ultrasonic receiving angle. Control The case) has been described as an example, but is not limited to this. That is, a transmitting probe having the same number of piezoelectric elements 26A as the number of piezoelectric elements constituting the transmitting element group 27A, and a receiving probe having the same number of piezoelectric elements 26B as the piezoelectric elements constituting the receiving element group 27B. And may be provided. Then, according to the change of the virtual inclination angle α of the defect, the transmitting array probe having the transmitting element group 27A is mechanically moved to variably control the transmission position of the ultrasonic wave, thereby configuring the transmitting element group 27A. The transmission timing of each piezoelectric element is controlled to variably control the transmission angle of the ultrasonic wave, and the reception array probe having the receiving element group 27B is mechanically moved to variably control the reception position of the ultrasonic wave. The reception angle of the ultrasonic wave may be variably controlled by controlling the reception timing of each piezoelectric element constituting the element group 27B. In this case, the same effect as described above can be obtained.

  In the fourth modification, the probe moving device 5A that mechanically moves the transmission / reception probe 52 including the transmission element group 27A and the reception element group 27B is provided (in other words, the target In the example described above, the transmission / reception probe 52 is mechanically moved in accordance with the change of the virtual position yp of the defect in the axial direction of the specimen 1 to variably control the transmission position and reception position of the ultrasonic wave. Not limited to this. That is, the probe moving device 5A need not be provided. Then, according to the change of the virtual position yp of the defect in the axial direction of the subject 1, the transmitting element group 27A and the receiving element group 27B are electronically selected from the piezoelectric elements of the transmitting / receiving probe 52, and ultrasonic waves are transmitted. The position and the reception position may be variably controlled. In this case, the same effect as described above can be obtained.

  In the above description, the case where the welded part 2 extending in the circumferential direction in the cylindrical subject 1 is an inspection target is described as an example, but the present invention is not limited thereto. That is, for example, a welded portion that extends linearly in a flat specimen may be an inspection target.

DESCRIPTION OF SYMBOLS 1 Subject 3 Defect 4A Transmitting array probe 4B Receiving array probe 5, 5A Probe moving device 6, 6A Transmitting / receiving device 7, 7A Propagation path control unit 13 Echo intensity data creation unit 27A Transmitting element group 27B Receiving element group 38 Three-dimensional image display unit 39 Actual tilt angle input unit 40 Two-dimensional image display unit 41 Three-dimensional image 44, 44A Two-dimensional image 45 Projected image display unit 46 Projected image 49 Actual tilt angle calculation unit 50 Actual range / real Center position calculator 51 Transmitter / receiver array probe

Claims (12)

An ultrasonic inspection method using a transmitting element group that transmits ultrasonic waves inside a subject and a receiving element group that receives ultrasonic waves reflected by the defects when a defect exists inside the subject. There,
Based on each of the plurality of ultrasonic propagation paths analyzed in advance according to the change of the virtual position of the defect and the change of the virtual tilt angle of the defect in one direction and the thickness direction of the subject The ultrasonic transmission position and transmission angle and the ultrasonic reception position and reception angle by the receiving element group are variably controlled,
Obtain the echo intensity of the defect from the waveform data of the received ultrasound acquired for each ultrasound propagation path,
Assuming the case where the echo intensity of the defect is shown in a three-dimensional coordinate system composed of the virtual position of the defect and the virtual tilt angle of the defect in one surface direction and thickness direction of the object, on the three-dimensional coordinate system A maximum value of echo intensity is obtained for a distribution of echo intensity larger than a predetermined threshold value, and a virtual inclination angle of the defect corresponding to the maximum value of the echo intensity is obtained as an actual inclination angle;
Assuming the case where the distribution of the echo intensity corresponding to the actual inclination angle of the defect is extracted and indicated by a two-dimensional coordinate system consisting of the virtual position of the defect in one direction and the thickness direction of the subject, Based on the range of the virtual position of the defect corresponding to a distribution of a cluster of echo intensities greater than a predetermined threshold on a two-dimensional coordinate system, the actual range of the defect in each of the surface direction and thickness direction of the subject Or / and an ultrasonic inspection method characterized by obtaining an actual center position. The ultrasonic inspection method according to claim 1,
Generate and display a three-dimensional image showing the echo intensity of the defect in a three-dimensional coordinate system consisting of the virtual position of the defect in the surface direction and thickness direction of the subject and the virtual tilt angle of the defect,
A maximum value of echo intensity is obtained for a distribution of echo intensity larger than a predetermined threshold on the three-dimensional image, and a virtual inclination angle of the defect corresponding to the maximum value of the echo intensity is obtained as an actual inclination angle. An ultrasonic inspection method characterized by the above. The ultrasonic inspection method according to claim 1,
Any one of the one-surface direction and the thickness direction of the subject under the same conditions of the virtual position of the defect and the virtual tilt angle of the defect in one of the one-surface direction and the thickness direction of the subject The maximum value is obtained for the echo intensity of the defect that differs depending on the virtual position of the defect on the other side, and the maximum value of the echo intensity is determined in one of the one surface direction and the thickness direction of the subject. Generate and display a projection image shown in a two-dimensional coordinate system consisting of the virtual position of the defect and the virtual tilt angle of the defect,
A maximum echo intensity value is obtained for a distribution of echo intensity blocks larger than a predetermined threshold on the projection image, and a virtual inclination angle of the defect corresponding to the maximum echo intensity value is obtained as an actual inclination angle. Ultrasonic inspection method characterized by. The ultrasonic inspection method according to claim 1,
A distribution of echo intensity corresponding to the actual inclination angle of the defect is extracted to generate a two-dimensional image indicated by a two-dimensional coordinate system composed of virtual positions of the defect in one surface direction and thickness direction of the subject. Display
Based on a range of virtual positions of the defect corresponding to a distribution of echo intensity blocks larger than a predetermined threshold on the two-dimensional image, the actual range of the defect in each of the surface direction and thickness direction of the subject Or / and an ultrasonic inspection method characterized by obtaining an actual center position. The ultrasonic inspection method according to claim 1,
A transmitting array probe having a plurality of elements including the transmitting element group and a plurality of elements including the receiving element group in accordance with a change in the virtual position of the defect in one surface direction and thickness direction of the subject A receiving array probe having a mechanical movement to variably control the transmission position and reception position of ultrasonic waves,
According to the change in the virtual tilt angle of the defect, the transmitting element group is electronically selected from the plurality of elements constituting the transmitting array probe, and the transmission position of the ultrasonic wave is variably controlled. The transmission angle of the ultrasonic wave is variably controlled by controlling the transmission timing of each element constituting the element group, and the receiving element group is electronically selected from the plurality of elements constituting the receiving array probe. An ultrasonic inspection method, wherein the ultrasonic reception position is variably controlled, and the reception timing of each element constituting the reception element group is controlled to variably control the reception angle of the ultrasonic wave. The ultrasonic inspection method according to claim 1,
In response to a change in the virtual position of the defect in one direction of the surface of the subject, an ultrasonic wave is generated by mechanically moving a transmitting / receiving array probe having a plurality of elements including the transmitting element group and the receiving element group. Variably control the transmission position and reception position of
An ultrasonic transmission position by electronically selecting the transmission element group from the plurality of elements constituting the transmission / reception array probe in accordance with a change in the virtual position of the defect in the thickness direction of the subject. And variably controlling the reception position of the ultrasonic wave by electronically selecting the receiving element group from the plurality of elements constituting the transmitting / receiving array probe,
According to the change in the virtual tilt angle of the defect, the transmitting element group is electronically selected from the plurality of elements constituting the transmitting / receiving array probe, and the transmission position of the ultrasonic wave is variably controlled, and the transmission is performed. The transmission angle of the ultrasonic wave is variably controlled by controlling the transmission timing of each element constituting the element group, and the receiving element group is electronically selected from the plurality of elements constituting the transmitting / receiving array probe. An ultrasonic inspection method, wherein the ultrasonic reception position is variably controlled, and the reception timing of each element constituting the reception element group is controlled to variably control the reception angle of the ultrasonic wave. An ultrasonic inspection apparatus comprising: a transmitting element group for transmitting ultrasonic waves inside a subject; and a receiving element group for receiving ultrasonic waves reflected by the defects when a defect exists in the subject. There,
A transmission position controller that variably controls the transmission position of the ultrasonic wave by mechanically moving or electronically selecting the transmission element group;
A transmission angle control unit that variably controls the transmission angle of the ultrasonic wave by controlling the transmission timing of each element constituting the transmission element group;
A receiving position control unit that variably controls the receiving position of the ultrasonic wave by mechanically moving or electronically selecting the receiving element group; and
A reception angle control unit that variably controls the reception angle of the ultrasonic wave by controlling the reception timing of each element constituting the reception element group;
The transmission position control based on each of a plurality of ultrasonic wave propagation paths analyzed in advance according to the change of the virtual position of the defect in the one surface direction and the thickness direction of the subject and the change of the virtual tilt angle of the defect Control unit, the transmission angle control unit, the reception position control unit, and the reception angle control unit, the ultrasonic transmission position and transmission angle by the transmission element group, the ultrasonic reception position by the reception element group, and A propagation path controller that variably controls the reception angle;
Obtaining the echo intensity of the defect from the waveform data of the received ultrasonic wave obtained for each ultrasonic wave propagation path, the virtual position of the defect in one surface direction and the thickness direction of the subject, and the virtual tilt angle of the defect An echo intensity data creation unit for creating associated echo intensity data;
A three-dimensional image that generates and displays a three-dimensional image showing the echo intensity of the defect in a three-dimensional coordinate system composed of the virtual position of the defect in the surface direction and thickness direction of the subject and the virtual tilt angle of the defect. An image display unit;
An actual inclination angle input unit for the inspector to read and input the virtual inclination angle of the defect corresponding to the maximum value of the echo intensity in the distribution of echo intensity larger than the predetermined threshold on the three-dimensional image as an actual inclination angle When,
A distribution of echo intensity corresponding to the actual inclination angle of the defect is extracted to generate a two-dimensional image indicated by a two-dimensional coordinate system composed of virtual positions of the defect in one surface direction and thickness direction of the subject. An ultrasonic inspection apparatus comprising: a two-dimensional image display unit that displays the image. The ultrasonic inspection apparatus according to claim 7,
In place of the three-dimensional image display unit, a projection image display unit is provided,
The projected image display unit is configured so that the virtual position of the defect and the virtual tilt angle of the defect in any one of the surface direction and the thickness direction of the object have the same surface direction and A maximum value is obtained for the echo intensity of the defect that differs depending on the other of the thickness directions, and the maximum value of the echo intensity is set to one of the surface direction of the subject and the thickness direction. Generating and displaying a projection image shown in a two-dimensional coordinate system consisting of the virtual position of the defect and the virtual tilt angle of the defect,
The actual inclination angle input unit reads the virtual inclination angle of the defect corresponding to the maximum value of the echo intensity in the cluster distribution of echo intensity larger than a predetermined threshold on the projection image as an actual inclination angle. An ultrasonic inspection apparatus characterized by inputting. The ultrasonic inspection apparatus according to claim 7,
In place of the actual inclination angle input unit, a first calculation unit is provided,
The first calculation unit calculates a maximum value of echo intensity in a distribution of echo intensity larger than a predetermined threshold on the three-dimensional image, and the virtual inclination of the defect corresponding to the maximum value of the echo intensity An ultrasonic inspection apparatus that performs arithmetic processing using an angle as an actual inclination angle. The ultrasonic inspection apparatus according to claim 9.
A second computing unit,
The second calculation unit is configured to determine the surface of the subject in one direction and the thickness direction based on a range of virtual positions of the defect corresponding to a distribution of a set of echo intensities larger than a predetermined threshold on the two-dimensional image. An ultrasonic inspection apparatus characterized in that an actual range or / and an actual center position of the defect in each is processed. The ultrasonic inspection apparatus according to claim 7,
An array probe for transmission having a plurality of elements including the transmission element group;
A receiving array probe having a plurality of elements including the receiving element group,
The propagation path controller is
In accordance with the change of the virtual position of the defect in one surface direction and thickness direction of the object, the transmitting array probe and the receiving array probe are mechanically moved to transmit ultrasonic waves. And variable control of the receiving position,
According to the change in the virtual tilt angle of the defect, the transmitting element group is electronically selected from the plurality of elements constituting the transmitting array probe, and the transmission position of the ultrasonic wave is variably controlled. The transmission angle of the ultrasonic wave is variably controlled by controlling the transmission timing of each element constituting the element group, and the receiving element group is electronically selected from the plurality of elements constituting the receiving array probe. An ultrasonic inspection apparatus that variably controls an ultrasonic reception position and variably controls an ultrasonic reception angle by controlling a reception timing of each element constituting the reception element group. The ultrasonic inspection apparatus according to claim 7,
A transmission / reception array probe having a plurality of elements including the transmitting element group and the receiving element group,
The propagation path controller is
In accordance with the change of the virtual position of the defect in one direction of the surface of the subject, the transmission / reception position of the ultrasonic wave is variably controlled by mechanically moving the transmitting / receiving array probe,
An ultrasonic transmission position by electronically selecting the transmission element group from the plurality of elements constituting the transmission / reception array probe in accordance with a change in the virtual position of the defect in the thickness direction of the subject. And variably controlling the reception position of the ultrasonic wave by electronically selecting the receiving element group from the plurality of elements constituting the transmitting / receiving array probe,
According to the change in the virtual tilt angle of the defect, the transmitting element group is electronically selected from the plurality of elements constituting the transmitting / receiving array probe, and the transmission position of the ultrasonic wave is variably controlled, and the transmission is performed. The transmission angle of the ultrasonic wave is variably controlled by controlling the transmission timing of each element constituting the element group, and the receiving element group is electronically selected from the plurality of elements constituting the transmitting / receiving array probe. An ultrasonic inspection apparatus that variably controls an ultrasonic reception position and variably controls an ultrasonic reception angle by controlling a reception timing of each element constituting the reception element group.

Images