Ultrasonic Flaw Detection Device

Abstract

To provide an ultrasonic flaw detection device that can easily and accurately grasp damage conditions inside a fixing table from the outside using ultrasonic waves propagating along a surface of a hydraulic iron tube.SOLUTION: A transmitting probe 4a is attached to a bevel wedge 5a, and is attached and fixed to a holder main body 31a. The holder main body 31a and a frame body 32a are rotatably fixed. The frame body 32a and wheels 33 are connected via a connecting plate 35a and a connecting plate 35b. A transmitting probe 4b is attached to a bevel wedge 5b, and is attached and fixed to a holder main body 31b. The holder main body 31b and a frame body 32b are rotatably fixed. The frame body 32b and wheels 34 are connected via a connecting plate 35c and a connecting plate 35d. The frame body 32a and the frame body 32b are rotatably connected by a hinge portion 60.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technology for an ultrasonic flaw detector for evaluating the soundness of structures such as penstocks. [Background technology]

[0002] In recent years, the average age of structures such as penstocks used in power plants has exceeded 50 years, making the aging of facilities a major problem. If the penstock is damaged due to corrosion and wear inside the penstock's fixing base, it can have an impact on third parties and cause overflow electricity due to long-term power outages. To measure the thickness of the wall inside the fixing base of a penstock, power generation is stopped, the water flowing inside the penstock is stopped, temporary scaffolding is set up on the fixing base, and the penstock is inspected from inside. However, since the work is done on a steep slope, it is extremely dangerous, and in reality, many damage incidents have occurred inside the fixed base. Generally, periodic inspections of exposed penstocks are carried out once every 3 to 12 years. The thickness of the penstock used for stress assessment is measured from the outside of the pipe along a representative measurement line, and the results are used to evaluate the entire penstock. As a result, there is no method for measuring the thickness inside the fixed base from the outside, and it remains unmeasured, raising concerns about defects. Therefore, there is a need for a device that can easily detect flaws inside penstocks, even when they are filled with water.

[0003] One known technique for detecting flaws using ultrasound is, for example, a method of performing ultrasonic flaw detection using the diffraction phenomenon of SV waves (Shear Vertical Waves) (see Patent Document 1). In the angle beam method using SV waves, an ultrasonic beam is incident at an angle to the surface to be inspected and propagates into the interior of the structure to be inspected, and damage areas such as defects and corrosion inside the structure are inferred from the time and intensity of the resulting reflected echoes. This method uses an angle beam probe, and longitudinal ultrasonic waves generated by the transducer are refracted at the surface to be inspected and are totally reflected at or above the critical angle, being converted into ultrasonic shear waves. Only the converted ultrasonic shear waves propagate inside the structure. In the ultrasonic flaw detection method disclosed in Patent Document 1, a probe with a refraction angle set within the range of 78 to 88° is placed on the flaw detection surface, ultrasonic waves are transmitted with the tip of the probe aligned with the position of the start of the boundary between the flaw detection surface and a thick section extending above the flaw detection surface, and a received signal including a reflected echo from a reflection source located above the flaw detection surface is obtained using diffracted waves that propagate while spreading within the thick section. The method also discloses preferred ranges for the opening angle of the sound axes of the transmitting probe and the receiving probe and the angle of the roof angle.

[0004] However, when inspecting the inside of a penstock, a probe is placed on the surface of the iron pipe, but the ultrasonic flaw detection inspection method of Patent Document 1 has the problem that it is difficult to ensure a constant gap between the probe and the iron pipe in accordance with the curvature of the iron pipe surface. Furthermore, even if a certain gap could be secured between the probe and the iron pipe to match the curvature of the iron pipe surface, there was a problem in that the structure required replacing the wedge to change the ultrasonic refraction angle toward the material being inspected, making the operation complicated. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-151501 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of this situation, the present invention aims to provide an ultrasonic flaw detection device that can easily and accurately grasp the damage condition inside a fixed base from the outside by using ultrasonic waves (SV waves) that propagate along the surface of a pipe structure such as a penstock. [Means for solving the problem]

[0007] In order to solve the above problems, the ultrasonic flaw detection device of the present invention is a device that uses two angle beam probes to inspect defects in pipe structures with shear waves and SV waves, and includes a transmitting unit consisting of an ultrasonic transmitting probe and an angle beam wedge, a receiving unit consisting of an ultrasonic receiving probe and an angle beam wedge, and a transmitting unit Install and secure , the surface of the tubular structure and Between the transmitting unit a transmitting probe holder having a mechanism for ensuring a gap between the receiving part and the transmitting probe; Install and secure , the surface of the tubular structure and Between the receiving unit The ultrasonic testing device includes a receiving probe holder having a mechanism for ensuring a gap between the transmitting probe and the receiving probe, a transmitting frame that rotatably supports the transmitting probe holder by an axial member, a receiving frame that rotatably supports the receiving probe holder by an axial member, and a hinge mechanism that connects the transmitting frame and the receiving frame. The transmitting probe holder and the receiving probe holder, each having a mechanism for ensuring a gap with the surface of the tubular structure, ensure a constant gap between the probe and the tubular structure, such as a penstock, so that the probe can conform to the surface of the tubular structure. Specifically, even if gel is used as a contact medium, the gel can be prevented from being scraped off by operating the probe. Furthermore, the transmitting frame and the receiving frame that rotatably support the transmitting and receiving probe holders by an axial member, and the hinge mechanism that connects them, stabilize the positions of the transmitting probe and the receiving probe arranged circumferentially around the tubular structure, improving the sensitivity of ultrasonic testing along the axial direction of the tubular structure.

[0008] The constant gap secured between the probe and the tubular structure is preferably 0.3 to 0.7 mm, and more preferably 0.5 mm. The angle of the two beam probes is preferably 82 to 88°, more preferably 84 to 86°, and even more preferably 85°, and the frequency therefor is preferably 0.05 to 15 MHz, more preferably 0.1 to 2 MHz, and even more preferably 0.5 MHz. The reason why the present invention is described as an invention for a device using two oblique angle probes is that, while the present invention uses ultrasonic waves with low frequencies and long wavelengths, in the case of a device using one probe, the ultrasonic waves emitted from the probe remain inside the probe, making it difficult to detect flaws in the area in front of the probe.

[0009] In the ultrasonic flaw detection device of the present invention, the mechanism for ensuring a gap with the surface of the tubular structure preferably comprises a plurality of ball rollers.

[0010] In the ultrasonic flaw detector of the present invention, the transmitting frame is preferably connected to an axle via a connecting plate, and magnetic wheels are provided on both ends of the axle. The magnetic wheels are attached to the periphery of the penstock, thereby improving the operability of inspection around the penstock.

[0011] In the ultrasonic flaw detection device of the present invention, the angle beam wedge may be filled with a liquid, and the liquid to be filled may be replaceable. By filling the angle beam wedge with a liquid and replacing the liquid with one of a different density, angle beam flaw detection can be performed at any angle without changing the shape of the wedge (without replacing the wedge).

[0012] In the ultrasonic flaw detection device of the present invention, the ultrasonic transmitting probe and the ultrasonic receiving probe are mark Withstands high voltages of over 800 volts A vibrator is provided It is preferable that the voltage be able to withstand a high voltage of 1000 volts or more. A vibrator is provided , and more preferably, withstands high voltages of 1500 volts or more. A vibrator is provided Withstands high voltage vibrator By using this, it is possible to transmit high-power ultrasonic waves, and the flaw detection distance can be extended.

[0013] In the ultrasonic flaw detection device of the present invention, the ultrasonic transmitting probe and the ultrasonic receiving probe are mark Withstands high voltages of over 800 volts A vibrator is providedIt is preferable that the angle of incidence of the shear SV waves incident from the angle wedge onto the tubular structure is 82 to 88°. The oblique angle of the angle wedge and the density inside the wedge are adjusted so that the angle of incidence of the shear SV waves incident from the angle wedge onto the tubular structure is 82 to 88°. If the angle of incidence of the shear SV waves incident from the wedge onto the tubular structure is 82 to 88°, it is possible to capture the reflected echo even if there is a distance between the measurement point and the defect location. [Effects of the Invention]

[0014] The ultrasonic flaw detector of the present invention has the advantage that a certain gap can be secured between the probe and the iron pipe in accordance with the curvature of the iron pipe surface, making it possible to easily and accurately grasp the damage status inside the fixed base from the outside. Furthermore, by using a wedge filled with liquid, the ultrasonic refraction angle can be changed without replacing the wedge, which has the advantage of improving convenience. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a front view of an ultrasonic flaw detector according to a first embodiment of the present invention; [Figure 2] 1 is a plan view of an ultrasonic flaw detector according to a first embodiment of the present invention; [Figure 3] Bottom view of the ultrasonic flaw detector of Example 1 [Figure 4] Image of ultrasonic flaw detection equipment in use [Figure 5] Illustrative diagram of an ultrasonic probe according to a second embodiment [Figure 6] Simulation results for various liquids inside the wedge [Figure 7] Illustration of penstock soundness inspection [Figure 8] An explanatory diagram of a conventional ultrasonic flaw detector [Figure 9] Illustration of transmission and reception of ultrasonic flaw detector [Figure 10] Graph showing the sensitivity of the probe in the ultrasonic flaw detector of Example 1 [Figure 11] Ultrasonic flaw detection flow chart of Example 1 DETAILED DESCRIPTION OF THE INVENTION

[0016] An example of an embodiment of the present invention will be described in detail below with reference to the drawings. Note that the scope of the present invention is not limited to the following examples and illustrated examples, and many modifications and variations are possible. [Example]

[0017] Fig. 1 shows a front view of the ultrasonic flaw detector of Example 1. As shown in Fig. 1, the ultrasonic flaw detector 1 is composed of detection units (2a, 2b) and a probe holder 3, and the detection units (2a, 2b) are attached and fixed to the probe holder 3. The detection unit 2a is composed of a transmitting probe 4a and an angle beam wedge 5a, and the detection unit 2b is composed of a receiving probe 4b and an angle beam wedge 5b. The angle beam wedges (5a, 5b) are made of high-density polystyrene, which has little material variation and is relatively easy to process.

[0018] Fig. 2 shows a plan view of the ultrasonic flaw detector of Example 1. Fig. 3 shows a bottom view of the ultrasonic flaw detector of Example 1. The transmitting probe 4a shown in Figures 1 to 3 is an ultrasonic probe, and as shown in Figure 3, it is provided with a high-voltage 1-3 composite vibrator 7a that can withstand a high voltage of 1000V. A probe cable 9a is connected to the transmitting probe 4a via a connector 90a. The transmitting probe 4a is attached to an angle wedge 5a using fasteners (6a to 6d), and the detecting unit 2a is attached and fixed to a holder main body 31a as shown in Figures 1 to 3. A gap is provided between the holder main body 31a and the frame body 32a, and the holder main body 31a and the frame body 32a are rotatably fixed by shaft members (63a, 63b). The wheel 33 has wheels (33b, 33c) provided on both longitudinal ends of the wheel shaft 33a. As shown in Fig. 2, the frame body 32a and the wheel 33 are connected via connecting plates (35a, 35b). Specifically, the frame body 32a and the connecting plate 35a are rotatably fixed by a fastener 61a, and the frame body 32a and the connecting plate 35b are rotatably fixed by a fastener 61b. The wheel 33 and the connecting plate 35a are rotatably fixed by a fastener 62a, and the wheel 33 and the connecting plate 35b are rotatably fixed by a fastener 62b.

[0019] The receiving probe 4b shown in FIGS. 1 to 3 is an ultrasonic probe, and as shown in FIG. 3, is provided with a high-voltage 1-3 composite vibrator 7b. A probe cable 9b is connected to the receiving probe 4b via a connector 90b. The receiving probe 4b is attached to an angle wedge 5b using fasteners (6e to 6h), and the detecting unit 2b is attached and fixed to a holder main body 31b as shown in FIGS. 1 to 3. A gap is provided between the holder main body 31b and the frame body 32b, and the holder main body 31b and the frame body 32b are rotatably fixed by shaft members (63c, 63d). The wheels 34 are provided with wheels (34b, 34c) at both longitudinal ends of the wheel shaft 34a. As shown in Fig. 2, the frame body 32b and the wheels 34 are connected via connecting plates (35c, 35d). Specifically, the frame body 32b and the connecting plate 35c are rotatably fixed by a fastener 61c, and the frame body 32b and the connecting plate 35d are rotatably fixed by a fastener 61d. The wheels 34 and the connecting plate 35c are rotatably fixed by a fastener 62c, and the wheels 34 and the connecting plate 35d are rotatably fixed by a fastener 62d.

[0020] As shown in Fig. 3, frame body 32a and frame body 32b are rotatably connected by hinge portion 60. As shown in Fig. 2, frame body 32a and frame body 32b are also connected by connecting plates (36a, 36b). Specifically, frame body 32a and connecting plate 36a are rotatably fixed by fastener 61e, and frame body 32a and connecting plate 36b are rotatably fixed by fastener 61g. Frame body 32b and connecting plate 36a are rotatably fixed by fastener 61f, and frame body 32b and connecting plate 36b are rotatably fixed by fastener 61h. As shown in FIG. 1, oval through-holes are provided in some of the connecting plates. Specifically, through-hole 11a is provided in connecting plate 35b, through-hole 11b is provided in connecting plate 35d, and through-hole 11c is provided in connecting plate 36b. By providing oval through-holes in the connecting portions, not only can the fixing points rotate, but the fixing positions of the fasteners can also move within the oval range, allowing them to move in accordance with the shape of the iron pipe. Although not shown, the connecting plates (35a, 35c, 36a) are also provided with a similar mechanism. In this embodiment, hexagon socket head bolts are used as the fasteners (61a to 61h) and hexagon cap nuts are used as the fasteners (62a to 62d), but the fasteners are not limited to these members and a wide range of known fasteners can be used.

[0021] In this way, not only are the frame bodies (32a, 32b) and the wheel parts (33, 34) movable, but the frame bodies (32a, 32b) and the holder main bodies (31a, 31b) are also movable, and further, the frame bodies 32a and 32b are also movable. This results in a structure in which the detection parts (2a, 2b) are independently movable, and the angle of the probe in the circumferential direction can be changed to match the curvature of the iron pipe 12 to be inspected. 3, large ball rollers (8a to 8d) with plunger functions (not shown) are provided on the back surface of holder main body 31a, and similar ball rollers (8e to 8h) are provided on the back surface of holder main body 31b. By providing the ball rollers (8a to 8h), the heights of transmitting probe 4a and receiving probe 4b can be adjusted, and an appropriate gap between them and iron pipe 12 can be adjusted.

[0022] Fig. 7 is an explanatory diagram of a penstock soundness inspection. As shown in Fig. 7, damage events such as damaged portion 15 often occur inside a portion of an iron pipe 12 where a fixing base 14 is provided. Therefore, in an inspection of the soundness of a penstock using the ultrasonic flaw detector 1 of Example 1, the state of damage inside the fixing base 14 of the iron pipe 12 is inspected from the outside using ultrasonic waves 13 (SV waves) that propagate along the surface of the penstock. Specifically, in the ultrasonic flaw detector 1, ultrasonic waves 13a are emitted from the detector 2a, and the reflected echo 13b is detected by the detector 2b.

[0023] FIG. 4 is an image diagram of an ultrasonic flaw detector in use, where (1) shows the ultrasonic flaw detector of the embodiment, and (2) shows the ultrasonic flaw detector of the prior art. 8A and 8B are external views of an ultrasonic flaw detector according to the prior art, with (1) being a front view and (2) being a plan view. As shown in Fig. 8A or 8B, the ultrasonic flaw detector 100 according to the prior art has the same detection units (2a, 2b), wheel units (33, 34), connecting plates (35a, 35b), and fasteners (61a to 61d, 62a to 62d) as the ultrasonic flaw detector 1 according to the first embodiment. However, unlike the ultrasonic flaw detector 1 according to the first embodiment, the ultrasonic flaw detector 100 according to the prior art has a structure in which the holder body 310 of the probe holder 300 is immovable. 4(2), in the case of the ultrasonic flaw detector 100 of the prior art, the gap between the detection units (2a, 2b) and the surface of the iron pipe 12 cannot be kept constant as the curvature of the iron pipe 12 changes. In contrast, in the ultrasonic flaw detector 1 of Example 1, the frame bodies (32a, 32b), holder bodies (31a, 31b), and ball rollers (8a-8h) are movable, so that the gap between the detection units (2a, 2b) and the surface of the iron pipe 12 can be kept constant as the curvature of the iron pipe 12 changes.

[0024] As mentioned above, the transmitting probe 4a and the receiving probe 4b use 1-3 composite vibrators (7a, 7b) with a high withstand voltage of 1.5 kV. These 1-3 composite vibrators (7a, 7b) use piezoelectric elements with a resonant frequency of 0.5 MHz. Conventionally, the withstand voltage of 1-3 composite piezoelectric elements is about 0.5 kV, and ceramic piezoelectric elements have been used for high withstand voltages. Piezoelectric elements are used below the polarization voltage, and since they lose their polarity when the polarization voltage is exceeded, ceramic piezoelectric elements with a high polarization voltage have been used. In the ultrasonic flaw detection device of the present invention, the adhesion of the vibrator electrodes has been strengthened (specifically, by extending the drying time and using a high-strength adhesive), which has made it possible to adopt a 1-3 composite vibrator (7a, 7b) with a high voltage resistance of 1.5 KV.

[0025] The other ends of the probe cables (9a, 9b) connected to the transmitting probe 4a and the receiving probe 4b are connected to an ultrasonic pulser / receiver (not shown). The ultrasonic pulser / receiver is also designed to have a high-voltage resistance structure. For example, a high-speed, high-voltage, insulated DC-DC converter is used to obtain high voltage, and the applied voltage can be adjusted continuously from 0V to 1000V. Each capacitor has a high-voltage resistance (1500V).

[0026] The transmitting probe 4a and receiving probe 4b use 1-3 composite vibrators (7a, 7b) with a high voltage resistance of 1.5 kV, and the angle wedges (5a, 5b) are adjusted so that the angle of incidence of the shear SV waves incident on the pipe structure from the wedge is 82 to 88 degrees. The angle of the angle wedge and the density inside the wedge are adjusted so that the angle of incidence of the shear SV waves incident on the pipe structure (iron pipe 12) from the ultrasonic waves emitted from the vibrator 7a through the angle wedge 5a is 82 to 88 degrees. This makes it possible to extend the detection distance from the measurement point to the defect location and capture the reflected echo from the defect.

[0027] Figure 9 explains the ultrasonic transmission and reception paths for ultrasonic flaw detection devices that use two angle probes to inspect defects in pipe structures with shear waves and SV waves, in two cases: one in which the crossing angle between the sound axes of the ultrasonic transmitting probe and the ultrasonic receiving probe is fixed, and one in which the crossing angle between the sound axes of the ultrasonic transmitting probe and the ultrasonic receiving probe is variable depending on the curvature of the iron pipe 12, as in the ultrasonic flaw detection device of the present invention. 9(1) shows a case where flaws are detected on a flat surface, where the detecting units 2a and 2b are parallel and the crossing angle of the sound axes is fixed, and shows a shear SV wave 13a emitted from the detecting unit 2a being reflected by a damaged area 15 and entering the detecting unit 2b as a shear SV wave (reflected echo) 13b. In fact, the reflected echo 13b returns to the detecting unit 2b while spreading out as ripples. Figure 9(2) shows the case where the same flaw detector as in Figure 9(1) (detecting unit 2a and detecting unit 2b are parallel and the crossing angle of the sound axes is fixed) is used to detect flaws on the surface of a curved iron pipe 12. In this case, the route of the reflected echo 13b changes, and the signal strength detected by detecting unit 2b decreases. Figure 9(3) shows the case where the ultrasonic flaw detector of Example 1 (in which the crossing angle of the sound axes of the detectors 2a and 2b is variable depending on the curvature of the iron pipe 12) is used to detect flaws on the surface of a curved iron pipe 12. Unlike the case of Figure 9(2), it is possible to detect signals while maintaining the signal strength detected by the detector 2b at the same level as in Figure 9(1).

[0028] Figure 10 is a graph showing the sensitivity of the probes in an ultrasonic flaw detector, with (1) showing the sensitivity of the comparative probe (0.8 MHz) and (2) showing the sensitivity of the probe of the embodiment (0.5 MHz). Both show waveforms obtained when detecting flaws in an actual penstock, where a rivet 250 mm away was detected. As shown in Figure 10(1), the sensitivity of the 0.8 MHz probe of the comparative example was 80.2 dB, while the sensitivity of the 0.5 MHz probe of the embodiment was 62.8 dB, indicating that the 0.5 MHz probe has a higher sensitivity by 17.4 dB (approximately 7.4 times).

[0029] Conventionally, flaw detection tests are performed with specific frequency filters set, and the optimal filter conditions are searched again after data collection is complete to find the optimal conditions. Figure 11 shows a flowchart of ultrasonic flaw detection in Example 1. As shown in Figure 11, first, a waveform is received by the receiver (step S01). When transmitting and receiving an ultrasonic waveform, for example, if 500 signals are transmitted and received per second, the resulting signal is averaged and processed. For example, if the result of receiving for a fixed period of time (0.1 seconds) (step S02) contains a lot of noise, and averaging of the received waveform data is necessary (step S03), averaging processing is performed (step S04). The averaging processing improves the signal-to-noise ratio (SNR) by averaging random noise (external and internal electronic noise), which may be higher than the sensitivity range used in general nondestructive testing when performing flaw detection in this example.

[0030] If filtering is required for the signal waveform data after averaging or for signal waveform data that does not require averaging (step S05), high-bandwidth signals are blocked (low-pass filter) (step S06), and low-bandwidth signals are further blocked (high-pass filter) (step S07). That is, window processing is performed to narrow the signal bandwidth and identify the reflected echo signal. Steps S06 and S07 may be performed in reverse order, or simultaneously. If filtering is required, filtered signal waveform data is acquired; if filtering is not required, the raw signal waveform data is acquired (step S08). Filtering refers to the fact that when ultrasonic waves propagate through a material, defect reflected echoes tend to be affected by the beam path length and the interior of the material, resulting in a frequency lower than the transmitted frequency. A wideband bandpass filter may be required to improve the identification of signal echoes. The ultrasonic flaw detection system of this embodiment is capable of performing wideband filtering in real time. If it is necessary to acquire the next waveform data, the receiver receives the waveform again (step S01). On the other hand, if it is not necessary to acquire the next waveform data, the ultrasonic flaw detection ends (step S09). [Example]

[0031] 5 is an explanatory diagram of the probe of Example 2, in which Fig. 5(1) shows an image view from the right side and Fig. 5(2) shows a plan view from the right side of the transmitting detector 200. The receiving detector is not shown here, but the arrangement of each component is the same as that of the transmitting detector 200. As shown in Figure 5 (1) or (2), the liquid wedge 500 is an angle beam wedge, and is made by filling a liquid 51 inside an acrylic resin case 50. The transmitting probe 4 is an ultrasonic probe, and is provided with a high-pressure-resistant 1-3 composite vibrator 7, which is attached and fixed to the liquid wedge 500 using a fastener 6. A probe cable 9 is connected to the transmitting probe 4 via a connector 90. Because the case 50 of the liquid wedge 500 is filled with the liquid 51, angle beam testing can be performed at any angle without replacing the wedge. The liquid 51 filled in the case 50 can be water, alcohol, ethanol, or the like.

[0032] Figure 6 shows the simulation results (differences in refraction angle in steel) when various liquids are used inside the wedge, with (1) water, (2) alcohol, and (3) ethanol used as the liquid. Two ultrasonic probes, one for transmitting and one for receiving, were used in the simulation. The incident angle was fixed at 20.5° as a setting condition for both. As shown in Figure 6(1), when the inside of case 50 was filled with water, the refraction angle of shear SV waves in steel was 48.3°. As shown in Figure 6(2), when the inside of case 50 was filled with alcohol, the refraction angle of shear SV waves was 69.0°. Furthermore, as shown in Figure 6(3), when the inside of case 50 was filled with ethanol, the refraction angle of shear SV waves was 87.2°. Therefore, it can be seen that the refraction angle of shear SV waves is approximately 45° when water is used, approximately 70° when alcohol is used, and that when ethanol is used, the waves propagate near the surface of the penstock.

[0033] By using the liquid wedge 500, shear waves and SV waves are not generated in the liquid 51 inside the wedge, so that the noise echoes caused by mode conversion of the ultrasonic waves generated inside the wedge can be eliminated, resulting in a clear received waveform during flaw detection. Also, by changing the internal liquid to one with a different sound speed, the ultrasonic refraction angle (constant incident angle) to the material being inspected can be changed without replacing the wedge, so it is possible to use a probe holder including the wedge with the same structure. [Industrial Applicability]

[0034] The present invention is useful for techniques for inspecting the soundness of penstocks, spillway pipes, and the like. [Explanation of symbols]

[0035] 1,100 Ultrasonic flaw detection equipment 2a, 2b, 200 Detector 3,300 Probe holder 4,4a transmitting probe 4b Receiving probe 5a, 5b Bevel Wedge 6, 6a~6h, 61a~61h, 62a~62d Fasteners 7,7a,7b 1-3 composite vibrator 8a~8h ball roller 9,9a,9b Probe cable 11a~11c through hole 12 Iron pipe 13,13a Ultrasound (transverse SV wave) 13b Reflection echo 14 Fixed base 15 Damaged area 31a, 31b, 310 Holder body 32a,32b frame 33,34 Wheel section 33a,34a Wheel axle 33b,33c,34b,34c wheels 35a~35d, 36a, 36b Connecting plates 50 cases 51 Liquid 60 Hinge part 63a~63d Shaft member 90,90a,90b connectors 500 Liquid Wedges

Claims

1. In an apparatus for inspecting defects in a tubular structure using a shear wave and a SV wave with a two-angle probe, a transmitting unit consisting of an ultrasonic transmitting probe and an angle wedge; a receiving section consisting of an ultrasonic receiving probe and an angle wedge; a transmitting probe holder for attaching and fixing the transmitting unit and having a mechanism for ensuring a gap between the surface of the tubular structure and the transmitting unit; a receiving probe holder for attaching and fixing the receiving unit and having a mechanism for ensuring a gap between the surface of the tubular structure and the receiving unit; a transmitting frame that rotatably supports the transmitting probe holder by a shaft member; a receiving frame that rotatably supports the receiving probe holder by a shaft member; a hinge mechanism connecting the transmitting frame and the receiving frame; Equipped with An ultrasonic flaw detection device characterized in that the mechanism for ensuring the gap is made up of a plurality of ball rollers.

2. An apparatus for inspecting defects in tubular structures using shear waves and SV waves with a two-angle probe, a transmitting unit consisting of an ultrasonic transmitting probe and an angle wedge; a receiving section consisting of an ultrasonic receiving probe and an angle wedge; a transmitting probe holder having a mechanism for attaching and fixing the transmitting unit and ensuring a gap between the surface of the tubular structure and the transmitting unit; a receiving probe holder having a mechanism for attaching and fixing the receiving unit and ensuring a gap between the surface of the tubular structure and the receiving unit; a transmitting frame that rotatably supports the transmitting probe holder by a shaft member; a receiving frame that rotatably supports the receiving probe holder by a shaft member; a hinge mechanism connecting the transmitting frame and the receiving frame; Equipped with The transmitting frame is connected to the wheel shaft via a connecting plate, An ultrasonic flaw detection device characterized in that magnetic wheels are provided on both ends of the wheel shaft.

3. 3. The ultrasonic flaw detection device according to claim 1, wherein the angle wedge is filled with a liquid, and the liquid is replaceable.

4. 3. The ultrasonic flaw detection device according to claim 1, wherein the ultrasonic transmitting probe and the ultrasonic receiving probe are provided with vibrators that can withstand a high applied voltage of 800 volts or more.

5. The ultrasonic wave transmitting probe and the ultrasonic wave receiving probe are provided with vibrators that can withstand a high voltage of 800 volts or more when applied; 3. The ultrasonic flaw detection device according to claim 1, wherein the angle of incidence of the shear SV wave incident on the tubular structure from the oblique angle wedge is 82 to 88 degrees.

Images