JP5285845B2 - Defect detection apparatus and defect detection method - Google Patents

Description

  The present invention relates to a defect detection apparatus and a defect detection method for detecting a defect generated in an inspection object installed in a nuclear power plant or other various plants.

  In general, it is known that defects such as deterioration and corrosion that occur in inspection objects installed in nuclear power plants and other various plants are more likely to occur in the welded area and in the vicinity thereof than in areas where the inspection object surface is not welded. It has been. For example, it is well known that an inspection object installed inside a nuclear power plant nuclear reactor has a high possibility of deterioration from the welded portion of the inspection object surface or the vicinity thereof. On the other hand, development of a technique for inspecting a portion where deterioration has occurred without destroying an inspection object has been advanced. Further, if a defect such as deterioration or corrosion occurs in the inspection object, repair welding is performed to repair the inspection object by welding the inspection object.

  After performing such repair welding, in order to confirm the soundness of the welding, a visual test (VT), a radiation transmission test (RT), a penetration test (PT), a magnetic particle test (MT) or an ultrasonic wave is used. A flaw detection test (UT) or the like is generally performed (see, for example, Non-Patent Document 1). In particular, a penetrant test (PT) and a magnetic particle test (MT) are used to detect welding defects occurring on the surface of the welded portion.

  Further, before the inspection object reaches macro cracking, fine grain boundary erosion occurs in the inspection object. For this reason, there is also a defect detection method for detecting a defect by generating a leaky surface wave for detecting grain boundary erosion and changing the sound speed of the leaky surface wave due to grain boundary erosion (for example, Non-Patent Document 2). reference.).

  Furthermore, Patent Document 1 describes a defect detection device that detects a defect generated on the surface of an inspection object with high accuracy.

  Furthermore, as a device for inspecting the state of defects such as deterioration and corrosion occurring on the surface of the inspection object in the liquid, defect detection that detects defects such as deterioration and corrosion of the inspection object using leakage surface waves There is a device (see, for example, Non-Patent Document 3). Patent Document 2 describes an ultrasonic inspection apparatus and an inspection method using the ultrasonic inspection apparatus for using the defect detection apparatus that uses this leaky surface wave at a site where a defect actually occurs. This apparatus and method not only inspect from a specific direction around a defect, but also inspect from a plurality of directions. Thereby, it is possible to accurately inspect even when defects such as deterioration have a certain size.

  FIG. 16 shows a schematic diagram of the defect detection apparatus 110 according to the prior art described above. Hereinafter, the defect detection apparatus 110 using the leaky surface wave will be described with reference to FIG.

  In FIG. 16, the inspection object 1 exists in a liquid medium 17 such as water. The defect detection apparatus 110 includes a piezoelectric element 101 such as a piezoelectric polymer PVDF sensor that irradiates the surface excitation wave 34, and an acoustic lens 100 that is attached to the piezoelectric element 101 and has a curved surface 104. Here, the acoustic lens 100 is attached to the piezoelectric element 101 so that the surface 104 of the acoustic lens 100 faces the opposite side of the piezoelectric element 101.

  When the defect 11 generated on the surface 1a of the inspection object 1 is inspected, the defect detection device 110 is generated on the surface 1a of the inspection object 1 so that the surface 104 of the acoustic lens 100 faces the inspection object 1 side. The defect 11 is disposed in the vicinity of the surface 1a side. The surface excitation wave 34 is irradiated from the piezoelectric element 101, and the surface excitation wave 34 is emitted from the surface 104 of the acoustic lens 100 into the liquid medium 17 between the acoustic lens 100 and the inspection object 1. After the surface excitation wave 34 reaches the inspection object 1, the surface excitation wave 34 excites the surface wave 30 propagating on the surface 1 a of the inspection object 1. The surface wave 30 generates a leaky surface wave 31 having information on the influence received from the surface 1 a while the surface wave 30 propagates on the surface 1 a of the inspection object 1, and the leakage surface wave 31 is generated from the inspection object 1. Leak into the liquid medium 17. By detecting this leaky surface wave 31, it is possible to detect the state of the defect 11 such as deterioration of the surface 1 a of the inspection object 1.

JP 2001-208729 A JP 2005-55200 A “Basics of Welding Technology”, edited by the Japan Welding Society, industry publication, p. 186 "Detection of fine grain boundary erosion on material surface by leaky surface acoustic wave (LSAW) (1st report) Application of water immersion critical angle method", Yokono Yasukazu et al., Non-destructive inspection, Vol. 51, No. 5 (2002) “Ultrasonic Handbook”, Edited by Ultrasonic Handbook Editorial Committee, Maruzen, p. 380

However, there is a problem when the above-described defect inspection apparatus and defect inspection method are actually used in the field.
In particular, when the surface of the inspection object is completely flat, it is relatively easy to use the defect inspection apparatus and the defect inspection method described above. For example, a welded portion is formed on the surface of the metal inspection object. In the case where a concavo-convex shape is formed, etc., since the critical angle changes according to the concavo-convex shape of the location to be inspected, it cannot be inspected accurately. That is, since the surface of the inspection object is often not flat as shown in FIGS. 17 and 18, for example, it is actually difficult to use the above-described defect inspection apparatus and defect inspection method.

  This is because the defect inspection apparatus and the defect inspection method described above use surface waves that propagate on the surface of the inspection object. That is, in these defect inspection apparatuses and defect inspection methods, in order to excite surface waves on the surface of the inspection object, the ultrasonic waves are irradiated so that the direction in which the surface excitation wave is irradiated becomes a critical angle with respect to the inspection object. To do. At this time, if the surface of the inspection object has an uneven shape, the surface wave leaks in a direction different from the assumed angle. As a result, it becomes difficult to detect the surface wave leaking from the inspection object, and the sensitivity to receive the surface wave is lowered due to the directivity of the piezoelectric element.

  In addition, even when a surface wave is excited on the surface of an inspection object using a piezoelectric element, in order to excite the surface wave, the piezoelectric element is arranged at a position that becomes a critical angle with respect to the inspection object. Need to be irradiated. For this reason, when the surface of the inspection object is not flat, the piezoelectric element cannot be disposed at an angle that can excite the surface wave correctly.

  Furthermore, in the defect inspection apparatus and the defect inspection method described above, when the portion where the surface wave propagates is a weld metal portion or the like, the ultrasonic wave is difficult to propagate, so the surface wave is significantly scattered and attenuated. For this reason, it cannot be determined whether the information on the detected leaky surface wave is information resulting from a defect such as deterioration in the weld metal part or information resulting from scattering / attenuation of the surface wave.

  Furthermore, the defect inspection apparatus and the defect inspection method described above have a problem that the area that can be inspected is narrow. When such an apparatus or method is actually used, there is a strong demand for shortening the time required for inspection as much as possible. However, such an apparatus or method has a narrow area that can be inspected, and even if the inspection apparatus is scanned, the time required for the inspection is extremely long.

  The present invention has been made in consideration of such points, and even if the surface shape of the inspection object is not flat, it is possible to accurately and stably detect defects generated on the surface of the inspection object, and weld metal An object of the present invention is to provide a defect detection apparatus capable of accurately detecting defects even in inspection objects with large scattering / attenuation of surface waves, etc., and inspecting inspection objects having a large area in a short time. To do.

The present invention relates to a defect detection apparatus that detects defects generated on the surface of an inspection object, and generates ultrasonic waves or shock waves from the surface of the inspection object by irradiating the surface of the inspection object with a surface excitation wave. An ultrasonic receiving mechanism having an ultrasonic excitation mechanism, a laser transmitting unit that emits laser light, and a laser receiving unit that receives laser light, and an optical path of laser light emitted from the laser transmitting unit A reflector that reflects the laser beam, a measurement mechanism connected to the ultrasonic receiver mechanism, and an optical path of the laser beam between the ultrasonic receiver mechanism and the reflector, and the optical path of the laser beam is an inspection object And an additional reflector that changes in a direction parallel to the surface of the laser beam, and the laser light emitted from the laser transmitter is reflected by the additional reflector and the reflector, and is reflected by the additional reflector and the reflector. Shi The laser beam is received by the laser receiving unit, and the ultrasonic wave or shock wave generated from the surface of the inspection object reaches the optical path of the laser beam between the additional reflector and the reflector, and the measurement mechanism It is characterized in that a defect on the surface of the inspection object is detected by observing a frequency change of the laser light received by the laser light receiving unit of the receiving mechanism .

The present invention is a detection method using a defect detection device, and generates ultrasonic waves or shock waves from the surface of an inspection object by irradiating the surface of the inspection object with a surface excitation wave from an ultrasonic excitation mechanism. A laser that changes the optical path of the laser beam in a direction parallel to the surface of the object to be inspected by an additional reflector. Laser light from a laser light transmitting section in which the frequency is changed by an ultrasonic wave or a shock wave from the surface of the inspection object that has reached the optical path of the laser light between the additional reflector and the reflector. The laser light receiving unit receives the laser beam, and the measurement mechanism includes a measurement step of observing the frequency change of the laser light received by the laser light receiving unit of the ultrasonic wave reception mechanism .

  ADVANTAGE OF THE INVENTION According to this invention, the defect which generate | occur | produced on the surface of the test object can be detected correctly and stably.

First Embodiment A first embodiment of a defect detection apparatus according to the present invention will be described with reference to FIGS.
Here, FIG. 1 is a schematic diagram showing the configuration of the defect detection apparatus according to the present embodiment, and FIG. 2 shows the configuration of the defect detection apparatus when the surface excitation wave 34 emitted from the ultrasonic excitation mechanism 2 is laser light. FIG. 3 is a schematic diagram illustrating the operation of the defect detection apparatus according to the present embodiment. FIG. 4 is a schematic diagram illustrating the operation of the defect detection apparatus according to the present embodiment when the positions of the defects 11 are different from those in FIG. It is.

First, the outline of the defect detection apparatus according to the present embodiment will be described with reference to FIG.
In the present embodiment shown in FIG. 1, the defect detection device 50 detects the defect 11 generated on the surface 1 a of the inspection object 1 installed in the liquid medium 17. Here, the defect detection device 50 irradiates the surface 1 a of the inspection object 1 with the surface excitation wave 34 to generate an ultrasonic wave such as the surface wave 30 or a shock wave 32 from the surface 1 a of the inspection object 1. The ultrasonic wave receiving mechanism 3 including the acoustic wave excitation mechanism 2, the laser light transmitting unit 3a that irradiates the laser light 35, and the laser light receiving unit 3b that receives the laser light 35, and the laser light 35 irradiated from the laser light transmitting unit 3a. And a reflector 4 that reflects the laser beam 35.

  The ultrasonic receiving mechanism 3 is connected to a measuring mechanism 7 and a receiving laser light source 6 via a laser light transmitting mechanism 5 that transmits laser light. Among these, the receiving laser light source 6 includes leak waves 31 and 31a leaking from a shock wave 32 generated by the surface excitation wave 34 from the ultrasonic excitation mechanism 2 and a surface wave 30 generated by the surface excitation wave 34, as will be described later. Is irradiated with a laser beam 35 for detecting. Further, a recording mechanism 8 that records detection data from the measuring mechanism 7 is connected to the measuring mechanism 7.

  As shown in FIG. 2, when the surface excitation wave 34 emitted from the ultrasonic excitation mechanism 2 is laser light, the transmission laser light source 9 is transmitted to the ultrasonic excitation mechanism 2 via the transmission laser light transmission mechanism 10. Is connected.

  Here, as the ultrasonic excitation mechanism 2, for example, a piezoelectric element, a focusing piezoelectric element, or means capable of exciting laser light, electromagnetic ultrasonic waves, or other ultrasonic waves can be considered. In particular, when the ultrasonic excitation mechanism 2 irradiates laser light as the surface excitation wave 34 as shown in FIG. 2, examples of the laser light source 9 include an Nd: YAG laser, a CO 2 laser, an Er: YAG laser, and a titanium sapphire laser. A pulse laser light source such as an alexandrite laser, a ruby laser, a dye (die) laser, or an excimer laser is used.

  Further, as the ultrasonic receiving mechanism 3, for example, a mechanism that irradiates a piezoelectric element, electromagnetic ultrasonic waves, or laser light can be considered. In particular, when the laser transmitting unit 3a of the ultrasonic receiving mechanism 3 irradiates the laser light 35, a mechanism such as an interference measuring mechanism can be considered as the measuring mechanism 7, and a Michelson interferometer, a homodyne interferometer, Heterodyne interferometers, Fizeau interferometers, Mach-Zehnder interferometers, Fabry-Perot interferometers, photorefractive interferometers, or other laser interferometers are conceivable. On the other hand, as a case where a mechanism other than the interference measuring mechanism is used as the measuring mechanism 7, a knife edge method or the like can be considered.

  Moreover, it is preferable that the reflective surface 4a irradiated with the laser beam 35 of the reflector 4 has the largest amount of return light of the laser beam 35 irradiated from the laser beam transmitting unit 3a, for example, a polished mirror surface is preferable. .

Next, the effect | action of this Embodiment is described using FIG.
First, the surface excitation wave 34 made of laser light, ultrasonic waves, or the like is applied to the surface 1 a of the inspection object 1 by the ultrasonic excitation mechanism 2. At this time, a shock wave 32, a surface wave 30, and a volume wave 36, a volume wave 37, and the like are generated inside the surface 1 a of the inspection object 1. The shock wave 32 and the surface wave 30 generated on the surface 1a of the inspection object 1 propagate through the inspection object 1 and the liquid medium 17 through the path shown in FIG. Moreover, the volume wave 36 and the volume wave 37 which generate | occur | produced inside the test target object 1 propagate in the test target object 1 through the path | route shown in FIG.

  In the present embodiment, a defect 11 such as deterioration is present on the surface 1 a of the inspection object 1. The surface wave S propagating on the surface 1 a becomes a surface wave 30 a in which the amplitude, frequency, etc. of the surface wave 30 are changed depending on the state of the defect 11. The surface wave 30a whose amplitude, frequency, etc. have changed is the inspection object 1 at the critical angle θ calculated from the sound velocity of the sound wave passing through the liquid medium 17 in which the inspection object 1 is installed and the inspection object 1. Leaks into the liquid medium 17 and becomes a leaky wave 31a.

  Next, the laser transmitting unit 3 a of the ultrasonic receiving mechanism 3 irradiates the laser light 35 toward the reflector 4, and the laser receiving unit 3 b of the ultrasonic receiving mechanism 3 is reflected by the reflector 4. 35 is received. Here, when an ultrasonic wave such as a leaky wave 31a from the surface 1a of the inspection object 1 or a shock wave 32 reaches the optical path of the laser beam 35 between the ultrasonic receiving mechanism 3 and the reflector 4, the laser beam is transmitted. The frequency of the laser beam 35 from the part 3a changes. The laser light receiving unit 3b receives the laser light 35 with the changed frequency.

  Next, the measurement mechanism 7 observes a change in the frequency of the laser beam 35 received by the laser receiving unit 3b. This change in the frequency of the laser beam 35 is the difference between the frequency of the laser beam 35 irradiated by the laser transmitter 3a and the frequency of the laser beam 35 received by the laser receiver 3b. As a result, the observer can obtain detection data including information on the leakage wave 31a, the shock wave 32, and the like from the inspection object 1.

  As described above, the laser light receiving unit 3b of the ultrasonic receiving mechanism 3 detects the laser light 35 whose frequency is changed by the leakage wave 31a, so that the ultrasonic excitation mechanism 2 and the ultrasonic wave in the surface 1a of the inspection object 1 are detected. Information on the defect 11 existing in the width d between the receiving mechanisms 3 can be detected. The defect 11 is, for example, an opening defect, a closing defect, a surface layer inherent defect, corrosion, a microcrack, a dislocation, a slip, or other deterioration state.

  Further, in the present embodiment shown in FIG. 3, if the defect 11 generated in the inspection object 1 is an opening defect, the surface wave 30 generated by the ultrasonic excitation mechanism 2 and the surface 1 a of the inspection object 1 are The shock wave 32 propagating in the liquid medium 17 along the same changes into the liquid medium propagation sound wave 33 at the opening portion of the defect 11, and the liquid medium propagation sound wave 33 propagates in the liquid medium 17. The ultrasonic receiving mechanism 3 detects the laser light 35 whose frequency has been changed by the liquid medium propagating sound wave 33, so that the inspection object 1 existing in the width d between the ultrasonic excitation mechanism 2 and the ultrasonic receiving mechanism 3 is detected. Information about the opened defect 11 can be detected.

  On the other hand, the volume wave 36 and the volume wave 37 generated by the ultrasonic excitation mechanism 2 are reflected by the defect 11 to become a volume wave 36a. Next, the volume wave 36 a undergoes mode conversion on the surface 1 a of the inspection object 1 to become a surface wave 30 a, and the surface wave 30 a becomes a leaky wave 31 a and propagates in the liquid medium 17.

  By the way, as shown in FIG. 4, the defect 11 generated on the surface 1 a of the inspection object 1 is not between the ultrasonic excitation mechanism 2 and the ultrasonic reception mechanism 3, and the ultrasonic reception mechanism as viewed from the ultrasonic excitation mechanism 2. It may exist on the side far from 3. Also in this case, similarly to the embodiment shown in FIG. 3, the surface wave 30 and the shock wave 32 are reflected or diffracted by the defect 11, and the leakage wave 31a and the shock wave 32a changed by the defect 11 are passed through the liquid medium 17. Propagate.

  As described above, according to the present embodiment, the amount of the return laser beam 35 from the reflector 4 is always constant by irradiating the reflector 4 with the laser beam 35 irradiated from the ultrasonic receiving mechanism 2. be able to. Therefore, for example, when the welded portion of the inspection object 1 has an uneven shape, or when the surface of the inspection object 1 has a curved portion, the surface 1a is not flat. It is possible to accurately and stably detect the defect 11 generated on the surface 1a.

  Further, according to the present embodiment, the defect detection device 50 is moved by a scanning mechanism (not shown), and the ultrasonic excitation mechanism 2 is disposed substantially directly above the defect 11 generated on the surface 1a of the inspection object 1. can do. In this case, the surface wave 30 and the shock wave 32 are diffracted by the defect 11 to become the liquid medium propagation sound wave 33 and the shock wave 32a, and the liquid medium propagation sound wave 33 and the shock wave 32a are detected by the ultrasonic receiving mechanism 3. At this time, since the distance that the surface wave 30 and the shock wave 32 propagate to the defect 11 is very short, the surface wave 30 and the shock wave 32 may be scattered or attenuated while propagating on the surface 1a of the inspection object 1. Absent. Thereby, the defect 11 generated on the surface 1a of the inspection object 1 can be detected with high accuracy.

Second Embodiment Next, a second embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 5 is a schematic diagram showing the configuration of the defect detection apparatus according to the present invention.

  The present embodiment shown in FIG. 5 is different only in that the ultrasonic excitation mechanism 2, the ultrasonic reception mechanism 3, and the reflector 4 are attached to the inspection object 1 with an inclination. Is the same as that of the first embodiment shown in FIG. 5, the same parts as those of the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

First, the outline of the defect detection apparatus according to the present invention will be described with reference to FIG.
In the present embodiment, the ultrasonic excitation mechanism 2 and the ultrasonic reception mechanism 3 include the irradiation direction of the surface excitation wave 34 irradiated from the ultrasonic excitation mechanism 2 to the inspection object 1 and the ultrasonic reception mechanism 3. It arrange | positions so that the irradiation direction of the laser beam 35 irradiated from the laser beam transmission part 3a may incline with respect to the test object 1. FIG. Similarly, the reflector 4 is disposed between the inspection object 1 and the ultrasonic reception mechanism 3 so as to be inclined with respect to the inspection object 1 in accordance with the inclination of the ultrasonic reception mechanism 3.

Next, the operation of the present embodiment having such a configuration will be described.
In the present embodiment shown in FIG. 5, the surface excitation wave 34 made of laser light, ultrasonic waves, or the like is irradiated onto the surface 1 a of the inspection object 1 by the ultrasonic excitation mechanism 2. As shown in FIGS. 1 to 4, when the ultrasonic excitation mechanism 2 is installed perpendicular to the surface 1 a of the inspection object 1, cavitation generated on the surface 1 a of the inspection object 1 is caused by the surface excitation wave 34. The ultrasonic excitation by the surface excitation wave 34 from the ultrasonic excitation mechanism 2 becomes unstable due to floating in the irradiation path. Therefore, as in the present embodiment shown in FIG. 5, the irradiation direction of the surface excitation wave 34 is inclined with respect to the inspection object 1.

As described above, according to the present embodiment, the cavitation generated on the surface 1 a due to the surface excitation wave 34 irradiated from the ultrasonic excitation mechanism 2 to the surface 1 a of the inspection target 1 is the optical path of the surface excitation wave 34. , The ultrasonic excitation can be prevented from becoming unstable, and the defect detection accuracy can be prevented from being lowered.

Third Embodiment Next, a third embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 6 is a schematic diagram showing the configuration of the defect detection apparatus according to the present invention.

  The present embodiment shown in FIG. 6 differs only in that the cleaning mechanism 12 is attached in the vicinity of the ultrasonic excitation mechanism 2 and the ultrasonic reception mechanism 3, and the other configuration is the first configuration shown in FIG. This is the same as the embodiment. In FIG. 6, the same parts as those of the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

First, the outline of the defect detection apparatus according to the present invention will be described with reference to FIG.
In the present embodiment, the inspection object 1 is installed in the liquid medium 17. Further, in the vicinity of the ultrasonic excitation mechanism 2 and the ultrasonic reception mechanism 3, the surface excitation wave 34 irradiated from the ultrasonic excitation mechanism 2 and the laser light transmitting unit 3 a of the ultrasonic reception mechanism 3 are irradiated. A cleaning mechanism 12 for spraying the same liquid medium 17 as the liquid around the inspection object 1 toward the optical path of the laser light 35 is provided.

Next, the operation of the present embodiment having such a configuration will be described.
In the present embodiment shown in FIG. 6, the cleaning mechanism 12 includes a path of the surface excitation wave 34 irradiated from the ultrasonic excitation mechanism 2 and a laser beam 35 irradiated from the laser light transmission unit 3 a of the ultrasonic reception mechanism 3. The same liquid medium 17 as the liquid around the inspection object 1 is sprayed toward the optical path. For example, in a nuclear power plant or the like installed in water, the cleaning mechanism 12 directs water to the path of the surface excitation wave 34 and the optical path of the laser beam 35 irradiated from the laser transmitter 3 a of the ultrasonic receiver 3. And removing impurities such as cladding existing in the path of the surface excitation wave 34 and the optical path of the laser beam 35.

  Thus, according to the present embodiment, the ultrasonic excitation and ultrasonic reception mechanism 3 by the ultrasonic excitation mechanism 2 due to the influence of impurities mixed in the liquid medium 17 in which the inspection object 1 is installed. It is possible to prevent the ultrasonic wave reception due to becoming unstable and perform stable measurement.

Fourth Embodiment Next, a fourth embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 7 is a schematic diagram showing the configuration of the defect detection apparatus according to the present invention.

  The present embodiment shown in FIG. 7 differs only in that the irradiation profile control mechanism 13 is provided on the path of the surface excitation wave 34 irradiated from the ultrasonic excitation mechanism 2, and the other configuration is shown in FIG. This is the same as in the first embodiment. In FIG. 7, the same parts as those of the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

First, an outline of the defect detection apparatus according to the present invention will be described with reference to FIG.
In the present embodiment, the profile of the surface excitation wave 34 that transmits and transmits the surface excitation wave 34 is changed on the path of the surface excitation wave 34 that is irradiated from the ultrasonic excitation mechanism 2 to the surface 1 a of the inspection object 1. An irradiation profile control mechanism 13 is provided.

Next, the operation of the present embodiment having such a configuration will be described.
In the present embodiment shown in FIG. 7, the irradiation profile control mechanism 13 changes the profile of the surface excitation wave 34 irradiated from the ultrasonic excitation mechanism 2 to the surface 1 a of the inspection object 1. Thereby, it becomes possible to control ultrasonic waves such as the surface wave 30 excited on the surface 1a of the inspection object 1. For example, when the irradiation profile control mechanism 13 has a function of creating a plurality of line-shaped irradiation profiles, the surface wave 30 and the shock wave 32 generated from the surface 1a also have waveforms reflecting the profiles. In particular, general electrical noise is often generated in a pulsed manner, but as shown in the present embodiment, the ultrasonic wave excitation mechanism 2 has a surface wave 30 having a characteristic profile via the irradiation profile control mechanism 13. By exciting the shock wave 32 and the like, only signal components having a characteristic profile can be easily extracted.

  As described above, according to the present embodiment, it is possible to reduce the influence of scattering / attenuation due to the weld metal or the like even on the inspection object 1 having a large scattering / attenuation such as the weld metal. Can be detected.

Fifth Embodiment Next, a fifth embodiment of the defect detection apparatus according to the present invention will be described with reference to FIGS. Here, FIG. 8 is a schematic diagram illustrating the configuration of the defect detection apparatus according to the present embodiment, and FIG. 9 is a schematic diagram illustrating the operation of the defect detection apparatus according to the present embodiment. The present embodiment shown in FIG. 8 differs only in that the optical path changing body 14 is provided on the path of the laser light 35 irradiated from the laser light transmitting section 3a of the ultrasonic receiving mechanism 3, and the other configurations are as follows. This is the same as the first embodiment shown in FIG. In FIG. 8, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fifth embodiment shown in FIG. 8, an additional reflector 14 that changes the optical path of the laser beam 35 is provided in the optical path of the laser beam 35 between the ultrasonic receiving mechanism 3 and the reflector 4. As shown in FIG. 8, the optical path changing body 14 reflects the optical path of the laser light 35 from the laser transmitting section 3 a of the ultrasonic receiving mechanism 3 toward the reflector 4, and the laser light 35 is reflected on the surface 1 a of the inspection object 1. Irradiate in parallel. The surface of the additional reflector 14 that is irradiated with the laser light 35 is preferably configured so that the amount of return light of the laser light 35 irradiated from the laser light transmitting unit 3a is the largest, for example, polished to a mirror surface state. It is preferable that

Next, the operation of the present embodiment having such a configuration will be described with reference to FIG.
In FIG. 9, the laser light 35 irradiated from the laser light transmitting unit 3 a of the ultrasonic receiving mechanism 3 is reflected by the additional reflector 14, and the laser light 35 reflected by the additional reflector 14 is the surface of the inspection object 1. The light travels parallel to the surface 1a above 1a and enters the reflector 4. The laser beam 35 incident on the reflector 4 is reflected by the reflecting surface 4a of the reflector 4, travels parallel to the surface 1a above the surface 1a of the inspection object 1, and then enters the additional reflector 14 again. The laser beam 35 incident on the additional reflector 14 again is reflected by the additional reflector 14 again. The laser beam 35 reflected by the additional reflector 14 again enters the laser light receiving unit 3b of the ultrasonic receiving mechanism 3.

  Thereby, the ultrasonic wave receiving mechanism 3 widely receives the leaky wave 31 propagating into the liquid medium 17 from the surface wave 30 generated on the surface 1a of the inspection object 1 by the surface excitation wave 34 from the ultrasonic wave excitation mechanism 2. can do. Moreover, the inspection of the leaky wave 31 generated on the straight line parallel to the surface 1a of the inspection object 1 can be performed at a time, and a wide range inspection on the inspection object 1 can be performed in a short time.

Sixth Embodiment Next, a sixth embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 10 is a schematic diagram showing the configuration of the defect detection apparatus according to the present invention. In the present embodiment shown in FIG. 10, the laser transmitter 3a and the laser receiver 3b of the ultrasonic receiving mechanism 3 are configured as separate bodies, and are arranged between the laser transmitter 3a and the laser receiver 3b. The only difference is that the first reflector 14a and the second reflector 14b for changing the optical path of the laser beam 35 are provided on the optical path of the laser beam 35, and the other configuration is the fifth configuration shown in FIGS. This is the same as the embodiment. 10, the same parts as those in the embodiment shown in FIGS. 8 and 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

First, an outline of the defect detection apparatus according to the present invention will be described with reference to FIG.
In the present embodiment, the laser light transmitting unit 3a and the laser light receiving unit 3b of the ultrasonic receiving mechanism 3 are configured separately, and the laser light transmitting unit 3a and the laser light receiving unit 3b are provided apart from each other. . A first reflector 14a and a second reflector 14b that change the optical path of the laser beam 35 are provided in the optical path of the laser beam 35 between the laser transmitter 3a and the laser receiver 3b of the ultrasonic receiving mechanism 3. ing.

Next, the operation of the present embodiment having such a configuration will be described.
In FIG. 10, the laser beam 35 emitted from the laser transmitting unit 3 a of the ultrasonic receiving mechanism 3 is reflected by the first reflector 14 a. The laser beam 35 reflected by the first reflector 14a travels in parallel with the surface 1a of the inspection object 1 and enters the second reflector 14b. The laser beam 35 incident on the second reflector 14 b is reflected by the second reflector 14 b and is incident on the laser light receiving unit 3 b of the ultrasonic receiving mechanism 3.

  Thereby, the ultrasonic wave receiving mechanism 3 widely receives the leaky wave 31 propagating into the liquid medium 17 from the surface wave 30 generated on the surface 1a of the inspection object 1 by the surface excitation wave 34 from the ultrasonic wave excitation mechanism 2. can do. Moreover, the inspection of the leaky wave 31 generated on the straight line parallel to the surface 1a of the inspection object 1 can be performed at a time, and a wide range inspection on the inspection object 1 can be performed in a short time.

Seventh Embodiment Next, a seventh embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 11 is a perspective view showing the configuration of the defect detection apparatus according to the present embodiment. In the present embodiment shown in FIG. 11, the ultrasonic receiving mechanism 3 has five ultrasonic receiving units 16a, 16b, 16c, 16d, and 16e each having a laser transmitting unit 3a and a laser receiving unit 3b. The only difference is that the other configuration is the same as that of the first embodiment shown in FIG. In FIG. 11, the same parts as those in the embodiment shown in FIGS.

Next, the defect detection apparatus according to the present embodiment will be described with reference to FIG.
In FIG. 11, the ultrasonic receiving mechanism 3 is provided above the surface 1a of the inspection object 1 where the defect 11 having an elongated opening is generated. The ultrasonic receiving mechanism 3 includes five ultrasonic receiving units 16a, 16b, 16c, 16d, and 16e each having a laser transmitting unit 3a and a laser receiving unit 3b. The ultrasonic receivers 16a, 16b, 16c, 16d, and 16e are arranged in a straight line in a direction parallel to the surface 1a of the inspection object 1, as shown in FIG.

  As described above, the ultrasonic receiving portions 16a, 16b, 16c, 16d, and 16e are arranged in a straight line in a direction parallel to the surface 1a of the inspection object 1, so that defects such as deterioration due to the surface wave 30 and the shock wave 32 are present. 11 can be obtained in a multidimensional manner. For this reason, the detection performance of the defect 11 can be improved by processing the information obtained in a multidimensional manner by a method such as an averaging process, a correlation process, or an aperture synthesis process. As a result, defects 11 generated on the surface 1a are also detected on the inspection object 1 in which the surface wave 30 and the shock wave 32 propagating on the surface 1a of the inspection object 1 such as welded metal are scattered or attenuated. It can be detected with high accuracy. In addition, since the present embodiment performs multidimensional measurement, the inspection area can be widened, and even when the area of the inspection object 1 is large, the defect 11 generated on the surface 1a can be quickly detected. Can be detected.

Eighth Embodiment Next, an eighth embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 12 is a perspective view showing the configuration of the defect detection apparatus according to the present embodiment. In the present embodiment shown in FIG. 12, the ultrasonic receiving mechanism 3 has five ultrasonic receiving units 16a, 16b, 16c, 16d, and 16e each having a laser transmitting unit 3a and a laser receiving unit 3b. The only difference is that the other configuration is the same as that of the first embodiment shown in FIG. In FIG. 12, the same parts as those in the embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

Next, the defect detection apparatus according to the present embodiment will be described with reference to FIG.
In FIG. 12, the ultrasonic receiving mechanism 3 is provided above the surface 1a of the inspection object 1 in which the defect 11 having an elongated opening is generated. The ultrasonic receiving mechanism 3 includes five ultrasonic receiving units 16a, 16b, 16c, 16d, and 16e each having a laser transmitting unit 3a and a laser receiving unit 3b. As shown in FIG. 12, the ultrasonic receivers 16a, 16b, 16c, 16d, and 16e are arranged in a straight line in the direction perpendicular to the surface 1a of the inspection object 1.

  In this manner, the ultrasonic receiving portions 16a, 16b, 16c, 16d, and 16e are arranged in a straight line in the direction perpendicular to the surface 1a of the inspection object 1, thereby causing defects 11 such as deterioration due to the surface wave 30 and the shock wave 32. Can be obtained in a multidimensional manner. For this reason, the detection performance of the defect 11 can be improved by processing the information obtained in a multidimensional manner by a method such as an averaging process, a correlation process, or an aperture synthesis process. As a result, defects 11 generated on the surface 1a are also detected on the inspection object 1 in which the surface wave 30 and the shock wave 32 propagating on the surface 1a of the inspection object 1 such as welded metal are scattered or attenuated. It can be detected with high accuracy. In addition, since the present embodiment performs multidimensional measurement, the inspection area can be widened, and even when the area of the inspection object 1 is large, the defect 11 generated on the surface 1a can be quickly detected. Can be detected.

Ninth Embodiment Next, a ninth embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 13 is a plan view showing the configuration of the defect detection apparatus according to the present embodiment. In the present embodiment shown in FIG. 13, the ultrasonic receiving mechanism 3 includes eight ultrasonic receiving units 16a, 16b, 16c, 16d, 16e, and 16f each having a laser transmitting unit 3a and a laser receiving unit 3b. , 16g, and 16h, and the other configuration is the same as that of the first embodiment shown in FIG. In FIG. 13, the same parts as those in the embodiment shown in FIGS.

Next, the defect detection apparatus according to the present embodiment will be described with reference to FIG.
In FIG. 13, the ultrasonic receiving mechanism 3 is provided above the surface 1 a of the inspection object 1 on which the defect 11 having an elongated opening is generated. The ultrasonic receiving mechanism 3 includes eight ultrasonic receiving units 16a, 16b, 16c, 16d, 16e, 16f, 16g, and 16h each having a laser transmitting unit 3a and a laser receiving unit 3b. ing. As shown in FIG. 13, the ultrasonic receivers 16a, 16b, 16c, 16d, 16e, 16f, 16g, and 16h are arranged at equal intervals on the same circumference with the ultrasonic excitation mechanism 2 as the center. .

  In this manner, the ultrasonic wave receiving units 16a, 16b, 16c, 16d, 16e, 16f, 16g, and 16h are arranged on the same circumference centering on the ultrasonic excitation mechanism 2 at equal intervals, so that the surface wave Information about the defect 11 such as degradation due to 30 or shock waves 32 can be obtained in a multidimensional manner. For this reason, the detection performance of the defect 11 can be improved by processing the information obtained in a multidimensional manner by a method such as an averaging process, a correlation process, or an aperture synthesis process. As a result, defects 11 generated on the surface 1a are also detected on the inspection object 1 in which the surface wave 30 and the shock wave 32 propagating on the surface 1a of the inspection object 1 such as welded metal are scattered or attenuated. It can be detected with high accuracy. In addition, since the present embodiment performs multidimensional measurement, the inspection area can be widened, and even when the area of the inspection object 1 is large, the defect 11 generated on the surface 1a can be quickly detected. Can be detected.

Tenth Embodiment Next, a tenth embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 14 is a perspective view showing the configuration of the defect detection apparatus according to the present embodiment. In the present embodiment shown in FIG. 14, the ultrasonic receiving mechanism 3 has 15 ultrasonic receiving units 16a, 16b, 16c, 16d, 16e, 16f each having a laser transmitting unit 3a and a laser receiving unit 3b. , 16g, 16h, 16i, 16j, 16k, 16l, 16m, 16n, and 16o, and the other configuration is the same as that of the first embodiment shown in FIG. 14, the same parts as those in the embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

Next, the defect detection apparatus according to the present embodiment will be described with reference to FIG.
In FIG. 14, the ultrasonic receiving mechanism 3 is provided above the surface 1a of the inspection object 1 where the defect 11 having an elongated opening is generated. Further, the ultrasonic receiving mechanism 3 includes 15 ultrasonic receiving units 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h, 16i, each having a laser transmitting unit 3a and a laser receiving unit 3b. 16j, 16k, 16l, 16m, 16n, 16o. Ultrasonic wave receivers 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h, 16i, 16j, 16k, 16l, 16m, 16n, and 16o are located above the surface 1a of the inspection object 1 as shown in FIG. They are arranged at equal intervals.

  In this way, the ultrasonic wave receivers 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h, 16i, 16j, 16k, 16l, 16m, 16n, and 16o are arranged at equal intervals above the surface 1a. Thus, information regarding the defect 11 such as deterioration due to the surface wave 30 or the shock wave 32 can be obtained in a multidimensional manner. For this reason, the detection performance of the defect 11 can be improved by processing the information obtained in a multidimensional manner by a method such as an averaging process, a correlation process, or an aperture synthesis process. As a result, defects 11 generated on the surface 1a are also detected on the inspection object 1 in which the surface wave 30 and the shock wave 32 propagating on the surface 1a of the inspection object 1 such as welded metal are scattered or attenuated. It can be detected with high accuracy. In addition, since the present embodiment performs multidimensional measurement, the inspection area can be widened, and even when the area of the inspection object 1 is large, the defect 11 generated on the surface 1a can be quickly detected. Can be detected.

Eleventh Embodiment Next, an eleventh embodiment of the defect detection apparatus according to the present invention will be described with reference to FIG.
Here, FIG. 15 is a perspective view showing the configuration of the defect detection apparatus according to the present embodiment. In the present embodiment shown in FIG. 15, the ultrasonic receiving mechanism 3 has five ultrasonic receiving units 16a, 16b, 16c, 16d, and 16e each having a laser transmitting unit 3a and a laser receiving unit 3b. The only difference is that the other configuration is the same as that of the fifth embodiment shown in FIG. In FIG. 15, the same parts as those in the embodiment shown in FIG.

Next, the defect detection apparatus according to the present embodiment will be described with reference to FIG.
In FIG. 15, the ultrasonic receiving mechanism 3 is provided above the surface 1a of the inspection object 1 where the defect 11 having an elongated opening is generated. The ultrasonic receiving mechanism 3 includes five ultrasonic receiving units 16a, 16b, 16c, 16d, and 16e each having a laser transmitting unit 3a and a laser receiving unit 3b. As shown in FIG. 15, the ultrasonic receivers 16 a, 16 b, 16 c, 16 d, and 16 e are arranged above the surface 1 a of the inspection object 1 in a horizontal row at equal intervals.

  In this way, by arranging the ultrasonic receivers 16a, 16b, 16c, 16d, and 16e in a horizontal row at equal intervals above the surface 1a, information on the defect 11 such as deterioration due to the surface wave 30 or the shock wave 32 can be obtained. It can be obtained multidimensionally. For this reason, the detection performance of the defect 11 can be improved by processing the information obtained in a multidimensional manner by a method such as an averaging process, a correlation process, or an aperture synthesis process. As a result, defects 11 generated on the surface 1a are also detected on the inspection object 1 in which the surface wave 30 and the shock wave 32 propagating on the surface 1a of the inspection object 1 such as welded metal are scattered or attenuated. It can be detected with high accuracy. In addition, since the present embodiment performs multidimensional measurement, the inspection area can be widened, and even when the area of the inspection object 1 is large, the defect 11 generated on the surface 1a can be quickly detected. Can be detected.

Schematic which shows the structure of the defect detection apparatus by the 1st Embodiment of this invention. Schematic which shows the structure of the defect detection apparatus in case the surface excitation wave irradiated from an ultrasonic excitation mechanism is a laser beam in the 1st Embodiment of this invention. Schematic which shows the effect | action of the defect detection apparatus by the 1st Embodiment of this invention. Schematic which shows an effect | action in case the position of a defect differs from FIG. 3 of the defect detection apparatus by the 1st Embodiment of this invention. Schematic which shows the structure of the defect detection apparatus by the 2nd Embodiment of this invention. Schematic which shows the structure of the defect detection apparatus by the 3rd Embodiment of this invention. Schematic which shows the structure of the defect detection apparatus by the 4th Embodiment of this invention. Schematic which shows the structure of the defect detection apparatus by the 5th Embodiment of this invention. Schematic which shows the effect | action of the defect detection apparatus by the 5th Embodiment of this invention. Schematic which shows the structure of the defect detection apparatus by the 6th Embodiment of this invention. The perspective view which shows the structure of the defect detection apparatus by the 7th Embodiment of this invention. The perspective view which shows the structure of the defect detection apparatus by the 8th Embodiment of this invention. The top view which shows the structure of the defect detection apparatus by the 9th Embodiment of this invention. The perspective view which shows the structure of the defect detection apparatus by the 10th Embodiment of this invention. The perspective view which shows the structure of the defect detection apparatus by the 11th Embodiment of this invention. Schematic diagram of a conventional defect detection device Schematic diagram showing a cross section of an inspection object having an uneven shape on the surface Schematic diagram showing a cross section of an inspection object having a curved surface on the surface

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection object 1a, 104 Surface 2 Ultrasonic excitation mechanism 3 Ultrasonic reception mechanism 3a Laser light transmission part 3b Laser light reception part 4 Reflector 5 Laser light transmission mechanism 6 Reception laser light source 7 Measurement mechanism 8 Recording mechanism 9 Transmission laser light source 10 Transmission laser beam transmission mechanism 11 Defect 12 Cleaning mechanism 13 Irradiation profile control mechanism 14 Additional reflector 14a First reflector 14b Second reflector 16a-o Ultrasonic wave receiving unit 17 Liquid medium 30 Surface wave 31, 31a Leakage wave 32, 32a Shock wave 33 Liquid medium propagation sound wave 34 Surface excitation wave 35 Laser light 36, 37 Volume wave 50 Defect detection apparatus 100 Acoustic lens 101 Piezoelectric element 110 Defect detection apparatus

Claims (6)

In a defect detection device that detects defects generated on the surface of the inspection object,
An ultrasonic excitation mechanism that generates ultrasonic waves or shock waves from the surface of the inspection object by irradiating the surface of the inspection object with a surface excitation wave;
An ultrasonic receiving mechanism having a laser transmitting unit for irradiating a laser beam and a laser receiving unit for receiving the laser beam;
A reflector that is disposed on the optical path of the laser light emitted from the laser light transmitting section and reflects the laser light;
A measurement mechanism connected to the ultrasonic reception mechanism;
An additional reflector that is provided in the optical path of the laser light between the ultrasonic receiving mechanism and the reflector and changes the optical path of the laser light in a direction parallel to the surface of the inspection object;
The laser light emitted from the laser transmitting unit is reflected by the additional reflector and the reflector, and the laser beam reflected by the additional reflector and the reflector is received by the laser receiving unit,
The ultrasonic wave or shock wave generated from the surface of the inspection object reaches the optical path of the laser beam between the additional reflector and the reflector,
A measurement mechanism detects a defect on the surface of an inspection object by observing a frequency change of laser light received by a laser light receiving unit of an ultrasonic reception mechanism. The defect detection apparatus according to claim 1, wherein a recording mechanism that records detection data from the measurement mechanism is connected to the measurement mechanism. The defect detection apparatus according to claim 1, wherein the ultrasonic excitation mechanism irradiates a pulse laser beam as a surface excitation wave. The ultrasonic excitation mechanism has a plurality of ultrasonic excitation units that generate ultrasonic waves or shock waves from the surface of the inspection object by irradiating the surface of the inspection object with a surface excitation wave. Item 2. The defect detection apparatus according to Item 1 . The defect detection apparatus according to claim 1, wherein the ultrasonic receiving mechanism includes a plurality of ultrasonic receiving units each including a laser transmitting unit and a laser receiving unit. A detection method using the defect detection apparatus according to claim 1 ,
A surface excitation process for generating ultrasonic waves or shock waves from the surface of the inspection object by irradiating the surface of the inspection object with a surface excitation wave from the ultrasonic excitation mechanism;
A laser beam irradiation process in which the laser beam transmitting unit of the ultrasonic receiving mechanism irradiates the laser beam;
A laser beam path changing step for changing the optical path of the laser beam in a direction parallel to the surface of the inspection object by an additional reflector;
The laser receiving unit receives the laser beam from the laser transmitting unit whose frequency has been changed by the ultrasonic wave or the shock wave from the surface of the inspection object that has reached the optical path of the laser beam between the additional reflector and the reflector. A laser beam receiving step,
A defect detection method, comprising: a measurement step of observing a frequency change of a laser beam received by a laser receiving unit of an ultrasonic reception mechanism.

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