JP2008039629A - Ultrasonic flaw detector and ultrasonic flaw detection method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detector capable of focusing an ultrasonic beam in a direction orthogonal to the arraying direction of vibrators, and an ultrasonic flaw detection method using it. <P>SOLUTION: The device includes a phased array probe 11 formed by arraying a plurality of vibrators 12 in a prescribed direction, and an acoustic lens 13 provided in contact with a transmission/reception face of the ultrasonic beam from the phased array probe 11. The acoustic lens 13 includes a groove 14 opened to the phased array probe 11 side, having a longitudinal direction formed in parallel with the arraying direction of the plurality of vibrators, and bent in a direction orthogonal to the arraying direction. A medium having sound velocity different from the acoustic lens 13 is filled in the groove 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrasonic flaw detector used for flaw detection of a subject, and more particularly to an ultrasonic flaw detector capable of easily focusing an ultrasonic beam and an ultrasonic flaw detection method using the same.

  2. Description of the Related Art Conventionally, a phased array probe including a plurality of transducers arranged in a predetermined direction has been used in ultrasonic flaw detection that uses ultrasonic waves to inspect the presence or absence of defects in a subject. When the phased array probe is used, there is an advantage that the propagation direction and the focal position of the ultrasonic beam can be moved by controlling the timing of exciting each transducer.

  However, in the case of a phased array probe in which a plurality of transducers are arranged in a line, an ultrasonic beam in the same direction as the transducer arrangement direction can be focused, but in a direction orthogonal to the arrangement direction. The ultrasonic beam cannot be focused. As described above, in a phased array probe in which a plurality of transducers are arranged in a row, the ultrasonic beam can be directed, so that the determination result varies depending on the shape of the defect of the subject. obtain.

  Therefore, the following method has been proposed in order to focus an ultrasonic beam in a direction orthogonal to the arrangement direction of the transducers.

  First, a method using a phased array probe curved in a direction perpendicular to the arrangement direction of transducers has been proposed (see, for example, Patent Document 1). By configuring the phased array probe in such a shape, it is possible to focus not only the transducer arrangement direction but also an ultrasonic beam in a direction orthogonal to the arrangement direction.

  Secondly, a method of performing ultrasonic flaw detection by a water immersion flaw detection method using an ultrasonic flaw detection apparatus including an acoustic lens has been proposed. FIG. 8 is a side view showing the configuration of the ultrasonic flaw detector in this case, and FIG. 9 is a front view showing the configuration of the ultrasonic flaw detector.

  As shown in FIGS. 8 and 9, a conventional ultrasonic flaw detector 100 is provided with a phased array probe 101 having a plurality of transducers 102 arranged in a row, and below the phased array probe 101. And an acoustic lens 103 having a lower surface curved in a direction orthogonal to the arrangement direction of the transducers 102.

  Thus, when the lower surface of the acoustic lens (the surface on which ultrasonic waves are transmitted and received) is a curved surface, direct contact with the subject or flaw detection by the gap method becomes difficult. Therefore, as shown in FIGS. 8 and 9, it is necessary to use the water immersion flaw detection method in which the test object 105 is immersed in the water 104 for flaw detection.

  With this configuration, it is possible to focus an ultrasonic beam in a direction orthogonal to the arrangement direction of the transducers 102.

Third, a method using a phased array probe including a plurality of transducers arranged in a matrix rather than in a single line has been proposed (see, for example, Patent Document 2). By arranging the transducers in a matrix in this way, it is possible to focus an ultrasonic beam not only in one direction but also in a direction orthogonal to that direction.
JP 2003-158799 A JP 2005-121660 A

  However, in the case of the first prior art, the position where the ultrasonic beam can be focused is fixed. Therefore, there is a problem that the target of ultrasonic flaw detection is limited. Originally, it was an advantage of the phase array probe that the focal position can be freely changed. However, this advantage disappears in the first prior art.

  Further, in the case of the second prior art, as described above, it must be based on the water immersion flaw detection method. Therefore, there is a problem that a large-scale device is required.

  Furthermore, according to the third prior art, the number of vibrators is increased as compared with the case where the vibrators are arranged in a row, and there is a problem that the cost is increased.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ultrasonic probe capable of focusing an ultrasonic beam in a direction orthogonal to the arrangement direction of transducers with a simple configuration. There is to do.

  In order to solve the above-described problems, an ultrasonic flaw detection apparatus according to the present invention is a phased array probe comprising a plurality of transducers arranged in a predetermined direction in an ultrasonic flaw detection apparatus used for ultrasonic flaw detection of a subject. A medium part in which the acoustic lens is provided in contact with an ultrasonic beam transmitting / receiving surface of the phased array probe, and the acoustic lens is filled with a medium having a different sound velocity from the acoustic lens The medium portion has a curved portion that curves in a direction orthogonal to the arrangement direction of the plurality of transducers.

  By providing the acoustic lens provided with such a medium portion, not only can the ultrasonic beam in the same direction as the arrangement direction of the transducers be focused, but also the ultrasonic beam in the direction orthogonal to the arrangement direction can be obtained. It is possible to focus.

  In the ultrasonic flaw detector according to the above invention, the medium portion is open to the phased array probe side, is formed so that its longitudinal direction is parallel to the arrangement direction of the plurality of transducers, and the curve The groove | channel which has a part may be sufficient.

  In the ultrasonic flaw detection apparatus according to the invention, the transmission / reception surface of the ultrasonic beam of the phased array probe may be inclined at a predetermined angle with respect to the flaw detection surface of the subject. Good.

  In this way, even when the phased array probe is an oblique angle probe, similarly, any ultrasonic beam in the same direction as the transducer arrangement direction and in a direction orthogonal thereto can be focused. Is possible.

  In the ultrasonic flaw detection apparatus according to the above invention, a flow path for guiding the medium filled in the groove to the flaw detection surface of the subject may be formed in the acoustic lens.

  The ultrasonic flaw detection method using the ultrasonic flaw detector according to the present invention continuously supplies a medium having a sound speed different from that of the acoustic lens to the groove in the ultrasonic flaw detector according to the invention. Using the medium overflowing from the medium as a contact medium between the acoustic lens and the subject, ultrasonic testing of the subject is performed.

  By using the medium overflowing from the groove as the contact medium in this way, more reliable flaw detection can be realized.

  According to the ultrasonic flaw detection apparatus and the ultrasonic flaw detection method using the ultrasonic flaw detection apparatus of the present invention, the ultrasonic beam is focused at an arbitrary position using a phased array probe in which transducers are arranged in a predetermined direction. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a side view showing the configuration of the ultrasonic flaw detector according to Embodiment 1 of the present invention. 2 is a cross-sectional view showing a cross section taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view showing a cross section taken along line III-III.

  As shown in FIGS. 1 and 2, an ultrasonic flaw detector 10 according to the present embodiment includes a phased array probe 11 including a plurality of transducers 12 arranged in a row, and the phased array probe. 11 is provided with an acoustic lens 13 provided on the lower surface (transmission / reception surface of the ultrasonic beam) 11 side.

  The acoustic lens 13 is disposed between the phased array probe 11 and the subject 16 that is the object of ultrasonic flaw detection, and the upper surface thereof is in contact with the lower surface of the phased array probe 11, and the lower surface is the subject. 16 is in contact with the upper surface.

  As shown in FIGS. 1 and 2, in the present embodiment, since the upper surface (flaw detection surface) of the subject 16 that contacts the lower surface of the acoustic lens 13 is a flat surface, the lower surface of the acoustic lens 13 is also a flat surface. However, the shape of the lower surface of the acoustic lens 13 is not limited to this, and any shape that conforms to the shape of the flaw detection surface of the subject 16 may be used.

  The acoustic lens 13 is provided with a groove 14 formed so that its longitudinal direction is parallel to the arrangement direction of the vibrators 12. The groove 14 is open to the phased array probe 11 side, and has a curved portion 15 that is curved with a predetermined radius of curvature in a direction orthogonal to the direction in which the transducers 12 are arranged.

  The groove 14 is filled with water as a medium used for acoustic coupling between the vibrator 12 and the acoustic lens 13.

  In the present embodiment, the water is filled in the groove 14 as described above. However, the present invention is not limited to this, and any material other than water may be used as long as the acoustic lens 13 has a different sound velocity. Therefore, instead of water, for example, resin may be filled in the groove 14 of the acoustic lens 13.

  As shown in FIGS. 1 and 3, the acoustic lens 13 is connected to the groove 14 at the top, and is provided with a flow path 19 a for guiding the water overflowing from the groove 14 to the flaw detection surface of the subject 16. ing. In the present embodiment, as shown in FIGS. 1 and 3, the two flow paths 19 a in contact with the flaw detection surface of the subject 16 are extended in the longitudinal direction of the groove 14. However, the shape of the flow path 19a is not limited to this, and any shape that can guide the water overflowing from the groove 14 to the flaw detection surface of the subject 16 may be used.

  As shown in FIGS. 1 and 2, the acoustic lens 13 is provided with a supply portion 19 b for supplying water to the groove 14.

  When performing ultrasonic flaw detection using the ultrasonic flaw detector 10 configured as described above, the ultrasonic beam 18 emitted from the transducer 12 propagates through the acoustic lens 13 and the flaw detection surface of the subject 16. Incident perpendicular to.

  Here, the timing of exciting each transducer 12 is controlled by a control unit (not shown) for transmitting and receiving ultrasonic waves so that the ultrasonic beam 18 is focused on the focal position 17 of the subject 16. Thereby, the ultrasonic beam 18 in the arrangement direction of the transducers 12 can be focused on the focal position 17.

  In the direction orthogonal to the arrangement direction of the transducers 12, the ultrasonic beam 18 emitted from the transducers 12 propagates in the water filled in the grooves 14 formed in the acoustic lens 13 and moves downward. Advancing and focusing at the bending portion 15 toward the focal position 17 of the subject 16.

  Thus, by forming the groove 14 having the curved portion 15 in the acoustic lens 13, it is possible to focus the ultrasonic beam 18 in a direction orthogonal to the arrangement direction of the transducers 12.

  By the way, while performing the ultrasonic flaw detection, water is continuously supplied to the groove 14 via the supply unit 19b. As a result, water overflows from the groove 14. The overflowing water is guided to the flow path 19 and reaches the flaw detection surface of the subject 16, and as a result, functions as a contact medium between the acoustic lens 13 and the subject 16.

  Even if the shape of the surface of the acoustic lens 13 on the subject 16 side is processed so as to conform to the shape of the flaw detection surface of the subject 16, a minute gap is generated between the acoustic lens 13 and the subject 16. Thus, by using the water overflowing from the groove 14 as a contact medium in this way, it is possible to realize more accurate flaw detection.

  The continuous supply of water to the groove 14 may be performed automatically by providing a device therefor, or may be performed manually.

  As described above, according to the ultrasonic flaw detector 10 of the present embodiment, it is possible to focus an ultrasonic beam not only in the same direction as the arrangement direction of the transducers 12 but also in a direction orthogonal to the arrangement direction. Note that unlike the first prior art described above, since the shape of the phased array probe itself is not processed, the focal position of the ultrasonic beam is not fixed. Further, since the shape of the lower surface of the acoustic lens 13 can be processed so as to conform to the shape of the flaw detection surface of the subject 16, flaw detection can be performed by direct contact with the subject 16 or by the gap method. Therefore, unlike the second prior art described above, there is no need for the water immersion flaw detection method, and a large-scale apparatus is not required. Furthermore, unlike the third prior art described above, a plurality of transducers need not be arranged in a matrix but only in a single row, so that the cost is not increased.

  Note that the focal position of the ultrasonic beam can be changed by changing the radius of curvature of the curved portion 15 of the groove 14 or the medium filled in the groove 14. Accordingly, the radius of curvature of the bending portion 15 or the type of medium is appropriately determined so that a desired focal position is obtained.

  In the present embodiment, as shown in FIG. 2, the groove 14 is filled with a medium. However, if the medium part to be filled with the medium has a curved part 15, it has a shape other than that. For example, as shown in FIG. 4, it may be a cavity 14a.

(Embodiment 2)
The ultrasonic flaw detection apparatus according to Embodiment 1 is used for ultrasonic flaw detection by the vertical flaw detection method. On the other hand, the ultrasonic flaw detection apparatus according to Embodiment 2 is used for ultrasonic flaw detection by the oblique flaw detection method in which an ultrasonic beam is incident at a predetermined angle with respect to the flaw detection surface of the subject. .

  FIG. 5 is a side view showing the configuration of the ultrasonic flaw detector according to Embodiment 2 of the present invention. 6 is a cross-sectional view showing a cross section taken along line VI-VI in FIG. 5, and FIG. 7 is a cross-sectional view showing a cross section taken along line VII-VII in FIG.

  As shown in FIGS. 5 and 6, the ultrasonic flaw detector 20 of the present embodiment includes a phased array probe 21 including a plurality of transducers 22 arranged in a row, and the phased array probe. 21 is provided with an acoustic lens 23 provided on the back side.

  The ultrasonic beam transmission / reception surface of the phased array probe 21 is inclined with respect to the flaw detection surface of the subject 26 by a predetermined angle. Thereby, the phased array probe 21 functions as an oblique angle probe.

  The acoustic lens 23 is provided on the lower surface (transmission / reception surface of the ultrasonic beam) side of the phased array probe 21 as in the case of the acoustic lens 13 in the first embodiment. The upper surface of the acoustic lens 23 is in contact with the lower surface of the phased array probe 21, and the lower surface is in contact with the upper surface of the subject 26. As described above, since the transmission / reception surface of the ultrasonic beam of the phased array probe 21 is inclined at a predetermined angle with respect to the flaw detection surface of the subject 26, the upper surface of the acoustic lens 23 is similarly the subject 26. It is inclined at a predetermined angle with respect to the flaw detection surface.

  As in the case of the acoustic lens 13 in the first embodiment, the acoustic lens 23 is provided with a groove 24 formed so that its longitudinal direction is parallel to the arrangement direction of the transducers 22. The groove 24 is open to the phased array probe 21 side, and has a curved portion 25 that is curved with a predetermined curvature radius in a direction orthogonal to the arrangement direction of the transducers 22.

  The groove 24 is filled with water as a medium used for acoustic coupling between the acoustic lens 23 and the vibrator 22. Similarly to the case of the first embodiment, the acoustic lens 13 has an upper portion connected to the groove 24 and a flow path 29 a for guiding the water overflowing from the groove 24 to the flaw detection surface of the subject 26. Is provided. Note that this medium does not have to be water as in the first embodiment.

  When performing ultrasonic flaw detection using the ultrasonic flaw detector 20 configured as described above, the ultrasonic beam 28 emitted from the transducer 22 propagates through the acoustic lens 23 and the flaw detection surface of the subject 26. Is incident at a predetermined angle.

  Here, as in the first embodiment, each transducer 22 is controlled by an ultrasonic transmission / reception control unit (not shown) so that the ultrasonic beam 28 is focused on the focal position 27 of the subject 26. The timing of excitation is controlled. Thereby, the ultrasonic beam 28 can be focused in the arrangement direction of the transducers 22.

  On the other hand, in a direction orthogonal to the arrangement direction of the transducers 22, the ultrasonic beam 28 emitted from the transducers 22 propagates in the water filled in the grooves 24 formed in the acoustic lens 23 and moves downward. Advancing and focusing at the bending portion 25 toward the focal position 27.

  As described above, since the groove 24 having the curved portion 25 is formed in the acoustic lens 23, the ultrasonic beam 28 in a direction orthogonal to the arrangement direction of the transducers 22 can be focused.

  As in the case of the first embodiment, while ultrasonic flaw detection is being performed, water is continuously supplied to the groove 24 via the supply unit 29b, so that the water overflows from the groove 24. The overflowing water is guided to the flow path 29 a and reaches the flaw detection surface of the subject 26, and as a result, functions as a contact medium between the acoustic lens 23 and the subject 26. As a result, more accurate flaw detection can be realized. As in the case of the first embodiment, the continuous supply of water to the groove 24 may be performed either automatically or manually.

  Thus, when the phased array probe is a beveled probe, the upper surface of the acoustic lens, that is, the surface in contact with the phased array probe, is the same as the phased array probe. However, the lower surface of the acoustic lens, that is, the surface in contact with the subject may be a flat surface or a shape along the subject's flaw detection surface. it can. Therefore, the distance between the acoustic lens and the focal position of the subject is the same as when the phased array probe is a vertical probe as in the first embodiment. Therefore, by providing the acoustic lens provided with the groove having the shape as described above, as in the case of the first embodiment, any ultrasonic beam in the direction in which the transducers are arranged and in the direction orthogonal to the arrangement direction is used. Can also be focused.

  The ultrasonic flaw detector according to the present invention focuses not only the ultrasonic beam in the same direction as the transducer arrangement direction of the phased array probe but also the ultrasonic beam in the direction orthogonal to the arrangement direction. Therefore, it is useful as an ultrasonic flaw detection apparatus used for ultrasonic flaw detection of various subjects.

It is a side view which shows the structure of the ultrasonic flaw detector which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the cross section along the II-II line | wire of FIG. It is sectional drawing which shows the cross section along the III-III line of FIG. It is sectional drawing which shows the other example of a structure of the ultrasonic flaw detector based on Embodiment 1 of this invention. It is a side view which shows the structure of the ultrasonic flaw detector which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the cross section along the VI-VI line of FIG. It is sectional drawing which shows the cross section along the VII-VII line of FIG. It is a side view which shows the structure of the conventional ultrasonic flaw detector. It is a front view which shows the structure of the conventional ultrasonic flaw detector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 Ultrasonic flaw detector 11,21 Phased array probe 12,22 Vibrator 13,23 Acoustic lens 14,24 Groove 15,25 Bending part 16,26 Subject 17,27 Focus position 18,28 Ultrasonic beam 19a, 29a Channel 19b, 29b Supply section

Claims (5)

In an ultrasonic flaw detector used for ultrasonic flaw detection of a subject,
A phased array probe in which a plurality of transducers are arranged in a predetermined direction;
An acoustic lens provided in contact with the transmission / reception surface of the ultrasonic beam of the phased array probe;
The acoustic lens is provided with a medium portion filled with a medium having a sound speed different from that of the acoustic lens,
The ultrasonic flaw detection apparatus according to claim 1, wherein the medium portion has a bending portion that is bent in a direction orthogonal to an arrangement direction of the plurality of transducers.   The medium portion is a groove that is open to the phased array probe side, has a longitudinal direction parallel to an arrangement direction of the plurality of transducers, and has the curved portion. The ultrasonic flaw detector described in 1.   The ultrasonic flaw detection apparatus according to claim 1, wherein a transmission / reception surface of the ultrasonic beam of the phased array probe is disposed at a predetermined angle with respect to the flaw detection surface of the subject.   4. The ultrasonic flaw detection according to claim 1, wherein a flow path for guiding a medium filled in the medium part to a flaw detection surface of the subject is formed in the acoustic lens. 5. apparatus.   A medium having a different sound velocity from the acoustic lens is continuously supplied to the medium part, and the medium overflowing from the medium part is used as a contact medium between the acoustic lens and the subject. The ultrasonic flaw detection method using the ultrasonic flaw detection apparatus in any one of Claim 1 thru | or 4 which performs the ultrasonic flaw detection of a test substance.

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