JP4646201B2 - Automatic ultrasonic flaw detector for tubular structures - Google Patents

Description

  The present invention relates to an automatic ultrasonic flaw detector for tubular structures. More specifically, the present invention relates to an improvement in technology for automatically detecting crack defects in tubular structures such as pressure pipes in power plants, petrochemical plants, buildings, and the like.

  The aging of existing thermal power generation facilities has progressed year by year, and in Europe and the United States, there is inherent heat damage in heat-affected zones (HAZ) that are difficult to detect by existing non-destructive inspection in high-temperature steam piping of aged thermal power plants. Experienced blast accidents caused by defects. In Japan, there is a strong concern for defects inherent in such structures as piping such as high-temperature steam piping.

  In addition to the weld heat-affected zone of such high-temperature steam pipes, there are inherent defects such as cracks that occur in structural materials, particularly welds of the structure, due to slag entrainment and poor penetration (in this specification, such cracks). An ultrasonic flaw detection test has been carried out as a nondestructive inspection to detect flaws and other internal defects called “crack defects” or simply “cracks”, with the aim of early detection of HAZ internal crack defects. Application studies such as the TOFD (Time of Flight Diffraction) method and the phased array method (PA method) are underway.

  In the TOFD method, ultrasonic waves are emitted between two probes for transmission and reception (probes), and the position of a crack defect in a structural material that is a flaw detector is identified. The “position” of the crack defect here means a three-dimensional position including both the position in the front-rear and left-right directions and the position (or height) in the thickness direction of the material. For example, flaw detection ultrasonic waves are transmitted from one of the two probes (probes) 101, 102 shown in FIG. 28 (transmitting probe 101) to the material 103 such as a pipe to be flaw detected. The lateral wave LW propagating on the surface of the material 103, the diffracted wave at the upper end 104a and the lower end 104b of the crack 104, and the reflected wave BW on the bottom surface of the material 103 are received by the other probe (receiving probe 102). The height and position of the crack 104 are identified from the phase difference (see FIG. 29). Incidentally, the diffracted wave at the tip of the defect such as the upper end 104a and the lower end 104b of the crack 104 is also called an end echo, and the method of measuring the height of the crack 104 using the propagation time difference of such an end echo is “ Also called “end echo method”. Then, according to the TOFD method as described above, the height and position of the crack 104 can be identified with high accuracy. In addition, in this TOFD method, the height of the crack 104 and the like can be adjusted only by performing a so-called line scan (also referred to as a D scan) in which the probes 101 and 102 are linearly moved in the longitudinal direction in parallel with the weld line 105. There is also a feature that it can be identified (see FIGS. 30 and 31).

  On the other hand, in the phased array method (PA method), a plurality of pulse receivers 201 and piezoelectric elements (piezo elements) 202 are arranged on a one-to-one basis (see FIG. 33), and the timing of an ultrasonic beam is shifted by shifting the timing of pulse voltages. It is possible to detect flaws by changing the direction and changing the depth of focus (see FIGS. 34 and 35). Previously, a single pulse receiver 201 vibrated a single piezoelectric element 202 through a cable 203 to generate ultrasonic waves (see FIG. 32), but this made it difficult to change the direction freely. Therefore, a flaw detection technique has been proposed that separates each of the plurality of pulse receivers 201 and the piezoelectric elements 202 to change the direction of the ultrasonic waves without changing the direction of the probe. According to such a phased array method, the direction of the ultrasonic wave can be changed by shifting the timing of voltage application to the piezoelectric element 202 without needing to change the direction of the probe (see FIGS. 34 and 35). In the case of the phased array method, there is also an advantage that three-dimensional information can be obtained by moving the probe having the above-described configuration only once in parallel with the weld line.

  Furthermore, a composite flaw detection technique in which flaw detection is performed by combining the above-described TOFD method and phased array method has also been proposed (see, for example, Patent Document 1).

JP 2001-50938 A

  However, although an ultrasonic flaw detection method having various advantages as described above has been developed or put into practical use, a tubular structure such as a high-temperature steam pipe (collectively referred to as “tubular structure” in this specification). Cracked defect in) automatically things like device capable of accurately testing there was no. That is, although there is a strong concern for defects inherent in tubular structures such as high-temperature steam pipes as described above, conventional automatic flaw detection capable of detecting such defects simply and with high accuracy. Since no device has been proposed, considerable effort has been required to detect crack defects, such as scanning the surface of a tubular structure by manual operation. In addition, the flaw detection results often differ depending on the skill level of the operator and the performance of the equipment, and there is also a problem that the accuracy is not so high although labor is required.

  Accordingly, an object of the present invention is to provide an automatic ultrasonic flaw detector for a tubular structure that can automatically and accurately detect a crack in a tubular structure such as a high-temperature steam pipe.

In order to achieve this object, the automatic ultrasonic flaw detector for a tubular structure according to claim 1 is movable in the circumferential direction along the outer periphery of the tubular structure to be inspected, and is provided in the tubular structure. A probe equipped with an ultrasonic probe for detecting a crack defect generated, and a drive source and a drive mechanism for reciprocally moving the ultrasonic probe in the axial direction of the tubular structure A child holder unit, a drive unit that is movable in the circumferential direction along the outer periphery of the tubular structure and that has a drive source for movement, and is interposed between the drive unit and the probe holder unit Similarly, the guide carriage unit that can move in the circumferential direction along the outer periphery of the tubular structure and the two plate-like members are overlapped with each other so that the entire length can be changed by steplessly sliding and connected to each other. It is a possible change of Serial guide the truck unit, and at least one of the connecting member for connecting each other interposed adjacent units in place, telescopic device member tightening the peripheral direction of the tubular structure between the probe holder unit and the drive unit The probe holder unit, the drive unit, the guide carriage unit, the connecting member and the device fastening member are connected to each other in the circumferential direction of the tubular structure and are annular, and the probe holder unit and the drive unit are They are placed at positions facing each other across the tubular structure to balance the weight, and these travel around the circumference of the tubular structure in the circumferential direction. The automatic flaw detection of crack defects.

  According to a second aspect of the present invention, in the automatic ultrasonic flaw detector for a tubular structure according to the first aspect, a track timing belt installed so as to go around the tubular structure, and a drive meshing with the track timing belt A timing pulley, and the drive timing pulley is rotated by a drive source to move the drive unit.

According to the automatic ultrasonic flaw detector for a tubular structure according to claim 1, an annular flaw detector is formed by combining and connecting units movable in the circumferential direction. It is possible to detect crack defects by rotating along the outer periphery. In addition, since this apparatus includes a unit (drive unit) that can be driven by a drive source, it is possible to automatically perform a flaw detection operation by automatic operation after being attached to the outer periphery of the tubular structure. Therefore, the operation and labor required for flaw detection are extremely small compared to the conventional apparatus in that each unit or the like connected in an annular shape can be automatically rotated around the outer periphery in that state and automatically flaw-detected. In addition, since automatic scanning is performed, it is easy to obtain an inspection result with higher accuracy than conventional manual scanning.
In addition, the probe holder unit and the drive unit, each equipped with a drive source, are placed at opposite positions across the tubular structure to balance the weight, so the automatic ultrasonic flaw detector rotates more smoothly. It becomes possible to make it. That is, when the operating resistance of the probe holder unit is the largest, it is possible to reduce the resistance as much as possible by disposing the probe holder unit at the position facing the drive unit. In addition, when the probe holder units are arranged so as to face each other as described above, it can be expected that the difference in operation resistance between the forward rotation and the reverse rotation of the automatic ultrasonic flaw detector is minimized. In addition, since the circumferential length of the connecting member can be changed as appropriate, the present apparatus can be applied even when tubular structures having different sizes are to be inspected, increasing versatility. Therefore, according to this, it becomes possible to inspect tubular structures of various sizes with a single automatic ultrasonic flaw detector, which is convenient.

  Moreover, the number of probe holder units is not limited to one. For example, an array probe holder unit or a TOFD probe holder unit can be provided with a plurality of types of probe holder units. It is. In such a case, since simultaneous flaw detection with different types of probes can be performed, it is possible to perform inspection with higher accuracy than flaw detection with a single probe.

  According to the automatic ultrasonic flaw detector described in claim 2, the drive unit can be moved along the track timing belt by rotating the drive timing pulley on the track timing belt of the tubular structure. In addition, since the drive timing pulley meshes with the track timing belt, it can move without causing slippage between the pulley and the belt, so that highly accurate scanning can be performed. .

  Hereinafter, the configuration of the present invention will be described in detail based on embodiments shown in the drawings.

  FIG. 1 shows an embodiment of the present invention. The automatic ultrasonic flaw detector 1 for a tubular structure according to the present invention is movable in the circumferential direction along the outer periphery of the tubular structure 2 to be inspected, and has a crack defect generated in the tubular structure 2. Probe holder units 4 and 5 mounted with ultrasonic probes (hereinafter also referred to as probes) 44, 57 and 58, and movable in the circumferential direction along the outer periphery of the tubular structure. Further, it is movable in the circumferential direction along the outer periphery of the drive unit 3 having the drive source 11 for movement and the tubular structure 2 interposed between the drive unit 3 and the probe holder units 4 and 5. A guide carriage unit 6, a connecting member 7 interposed between at least one of the guide carriage unit 6, the probe holder units 4, 5 and the drive unit 3, and connecting adjacent units, and a tubular structure Around the object 2 In which and a telescopic device fastening member 8 in direction. In the automatic ultrasonic flaw detector 1, the probe holder units 4 and 5, the drive unit 3, the guide carriage unit 6, the connecting member 7 and the device fastening member 8 are connected in the circumferential direction of the tubular structure 2. These are annular, and these travel in the circumferential direction along the outer periphery of the tubular structure 2 and perform automatic flaw detection of crack defects in the tubular structure 2 during this travel or stop (FIG. 1 and the like). reference).

  Here, the tubular structure 2 in the present embodiment is a general tubular object such as a high-temperature steam pipe of an aged thermal power plant, for example, due to welding heat affected zone, slag entrainment or poor penetration, etc. The structural material itself, in particular, may contain crack defects that occur in the welds of the structure.

  The drive unit 3 is provided as a drive device for rotating the automatic ultrasonic flaw detector 1 configured in an annular shape in the circumferential direction along the peripheral surface of the tubular structure 2. Various specific configurations of the drive device can be considered. For example, in the present embodiment, a toothed orbit timing belt 9 that circulates around the peripheral surface of the tubular structure 2 is provided, and a toothed tooth that meshes with this is provided. The drive unit 3 is moved in the circumferential direction by rotating the drive timing pulley 10 on the track timing belt (see FIGS. 1 and 2). The track timing belt 9 is a toothed belt having teeth on the outer peripheral side thereof, and is installed so as to go around the outer periphery of the tubular structure 2, and serves as a track of the drive timing pulley 10 to guide the drive unit 3 ( (See FIG. 2 etc.)

  Below, the structure of the drive unit 3 in this embodiment is demonstrated (refer FIGS. 3-9).

  The drive unit 3 of the present embodiment is a unit that moves in the circumferential direction on the tubular structure 2 along the above-described track timing belt 9, and is a drive source (hereinafter referred to as “drive motor” in the present embodiment). 11, a rotary encoder 12, a plurality of timing pulleys 13, 15, 17, a frame containing these various members (in this embodiment, the right frame 31 and the left frame 32 are illustrated), and provided at the bottom of this frame caster (wheel) 42, and a driving timing pulley 10 described above (see FIG. 3). Brackets 33 and 34 are provided on the right frame 31 and the left frame 32 of the drive unit 3, respectively (see FIGS. 3 and 4). A connecting member (hereinafter referred to as “connecting plate”) 7 can be connected to the brackets 33 and 34 by using connecting holes 33a and 34a (see FIGS. 1 and 6). . Further, casters 42 are attached to the bottom surfaces of the brackets 33 and 34 (see FIG. 3 and the like).

  The drive motor 11 is a drive source for driving the drive unit 3 and for automatically rotating the annular automatic ultrasonic flaw detector 1 around the tubular structure 2. In the present embodiment, the left and right frames 31 described above are used. , 32 and in the vicinity of the upper part of the unit, the motor rotation shaft is arranged so as to coincide with the long axis direction (hereinafter also referred to as the longitudinal direction) of the tubular structure 2 (FIG. 8, FIG. 9). In the present embodiment, a geared stepping motor is used as the driving motor 11, but this is only an example, and other motors such as a motor such as a five-phase pulse motor or a normal motor other than these motors are used. It goes without saying that it can also be done. A power cord 11a is connected to the main body of the drive motor 11, and power is supplied to the motor main body through the power cord 11a. In addition, a rotary encoder 12 is installed on the rear side end of the rotation shaft of the drive motor 11 (the side opposite to the drive timing pulley 10), so that the rotation amount and rotation speed of the rotation shaft can be detected. (See FIG. 8 etc.). On the other hand, a timing pulley 13 for transmitting a driving force is provided at the front side end of the rotating shaft of the driving motor 11, and a timing belt 14 is wound around the timing pulley 13 (FIG. 8, (See FIG. 9). The timing belt 14 is wound around still another timing pulley 15 supported by the right frame 31 (see FIG. 7). In the case of the present embodiment, the timing pulley 15 is installed obliquely below the drive motor 11, and therefore the timing belt 14 is wound obliquely between the timing pulleys 13 and 15 (see FIG. 4). Further, another timing belt 16 is wound between the timing pulley 15 and the timing pulley 17 fixed to the output shaft 18 (see FIGS. 7 and 17). The output shaft 18 is a shaft provided to transmit the rotation to the drive timing pulley 10, and the drive timing pulley 10 is fixed to the shaft end on the front side (see FIG. 8).

  The drive timing pulley 10 is preferably provided so that the radial position of the tubular structure 2 can be changed. If the diameter of the tubular structure 2 to be inspected changes, the curvature also changes, and the appropriate position of the drive timing pulley 10 also changes according to the curvature. If the position can be changed in this way, the tubular structure The position can be adjusted according to the size of the object 2. For example, in the present embodiment, two swing arms 19 and 20 that can swing around the same axis as the timing pulley 15 are arranged so as to sandwich the timing pulley 15, and bearings 21 and 20 are provided at respective tip portions. 22 is provided so that the output shaft 18 and the drive timing pulley 10 can be changed in radial direction by supporting the output shaft 18 so that the output shaft 18 can swing with the swing arms 19 and 20. (See FIGS. 3 and 7). By the way, if the output shaft 18 is a stepped shaft whose shaft diameter changes midway as in the present embodiment, and the bearings 21 and 22 are arranged in the stepped portion, these bearings 21 and 22 also function as a stopper, and the output There is an advantage that the shaft 18 can be prevented from shifting in the axial direction (see FIG. 8).

  Further, as shown in FIG. 3, at least one of the swing arms 19.20 is always pulled and biased upward (radially outward) by the tension coil spring 23 (see FIG. 3). Further, a stopper 24 is provided to limit the swingable range by abutting against one of the swing arms 19.20 (for example, the swing arm 19) (see FIGS. 3 and 8). The stopper 24 can move its lower end position up and down by turning the knob 25, and the radial position of the output shaft 18 and the drive timing pulley 10 can be changed by appropriately changing the abutting position on the swing arm 19. Can be adjusted (see FIGS. 3 and 8).

  A collar 26 is provided between the drive timing pulley 10 and the bearing 21 (see FIG. 8). Further, for example, a metal washer 27 is attached to the front shaft end of the output shaft 18 to prevent the drive timing pulley 10 from coming off (see FIG. 8).

  On the other hand, a roller 28 is attached to the rear shaft end of the output shaft 18 via a bearing 29 (see FIG. 8). This roller 28 is provided so as to be able to move while rolling on the peripheral surface of the tubular structure 2, and is slightly larger than the drive timing pulley 10 so that the output shaft 18 is always parallel to the peripheral surface. The diameter is formed (more specifically, by the thickness of the track timing belt 9) (see FIGS. 7 and 8). Further, a collar 30 for preventing the roller 28 from coming into contact with the swing arm 20 is interposed between the bearing 22 and the bearing 29 (see FIG. 8).

  The structure around the timing pulley 15 will also be described below. In the case of this embodiment, two support brackets 35 and 36 are installed side by side in the longitudinal direction on the right frame 31, and a support shaft 37 is supported by these support brackets 35 and 36 (see FIGS. 7 and 9). The timing pulley 15 described above is supported in a rotatable state at the center of the support shaft 37, and the swing arms 19 and 20 are supported at both ends of the support shaft 37, respectively. The support shaft 37 itself is also rotatable with respect to the support brackets 35 and 36 by interposing bearings 38 and 39 between the support brackets 35 and 36. Further, a retaining ring 40 is attached to one end side (for example, the back side) of the timing pulley 15 on the peripheral surface of the support shaft 37, and a resin washer 41 is attached to the other end side (for example, the front side), respectively. (See FIG. 9).

  A caster 42 is provided at the bottom of the drive unit 3. For example, in the present embodiment, four casters 42 are arranged and attached to substantially four corners of the drive unit 3 by using brackets 33 and 34 attached to the right and left frames 31 and 32.

  In the drive unit 3 as described above, the drive motor 11 is operated to drive the drive motor 11 → timing pulley 13 → timing belt 14 → timing pulley 15 → timing belt 16 → timing pulley 17 → output shaft 18 → drive. As the timing pulley 10 is rotated, the driving timing pulley 10 is rotated. When the drive timing pulley 10 rotates on the track timing belt 9, a force in the circumferential direction acts, and the drive unit 3 moves and rotates along the outer peripheral surface of the tubular structure 2.

  In addition, it is preferable that each of the timing pulleys 13, 15, and 17 and the timing belts 14 and 16 that are wound around the timing pulleys are toothed in terms of preventing slippage between the pulley and the belt. For example, in this embodiment, the timing pulley 15 and the like are toothed pulleys, and teeth (not shown) are provided on the inner periphery of the timing belt 14 and the like so as to mesh with each other so that no slip occurs during operation. (See FIG. 7 etc.).

  Next, mounting units (array probe holder unit 4 and TOFD probe holder unit 5) for mounting inspection probes (inspection probes) will be described.

  The array probe holder unit 4 is a device that uses the array probe 44 and changes the ultrasonic beam direction by shifting the timing of the pulse voltage to change the depth of focus, thereby detecting flaws. For example, in the present embodiment, the array probe holder unit 4 is provided with a guide shaft 45 composed of a pair of round bars parallel to each other so that the array probe 44 can move linearly along the guide shaft 45. It has become. Since the guide shaft 45 in this case is provided along the longitudinal direction (the axial direction of the tubular structure 2), the array probe 4 of the present embodiment is movable in the longitudinal direction. Therefore, after the array probe holder unit 4 is moved in the circumferential direction by the drive unit 3 described above and stopped, the array probe 44 can be moved in the longitudinal direction to perform ultrasonic flaw detection. ing. A bush 51 is provided in a portion of the guided hole through which the guide shaft 45 of the array probe 44 passes, and a retaining ring 52 is further attached (see FIG. 14). The flaw detection result by the array probe 44 is transmitted through the cable 44a.

  The drive motor 46 is a drive source for moving the probes in the array probe holder unit 4, that is, the array probe 44 in the longitudinal direction (the axial direction of the tubular structure 2). For example, in the present embodiment, the drive motor 46 is disposed laterally in the vicinity of the front surface of the array probe holder unit 4 (that is, the motor rotation axis is orthogonal to the longitudinal direction) (see FIG. 11). In this embodiment, a geared stepping motor is used as the drive motor 46, but this is only an example, and other motors can be used as in the case of the drive unit 3. A rotary encoder 47 is connected to the end of the rotating shaft of the driving motor 46 (for example, the end on the right side in FIG. 12) so that the amount of rotation and the rotating speed of the motor rotating shaft can be detected. (See FIGS. 11 and 12). The rotary encoder 47 is attached to the right frame 52 by, for example, screwing. In the present embodiment, the motor rotation shaft and the rotary encoder 47 are connected by the coupling 48 so as to straddle the guide shaft 45 (see FIG. 11).

  Further, a timing pulley 49 for transmitting a driving force is provided at the other end of the motor rotating shaft (for example, the left end in FIG. 12). Further, a timing belt 50 is wound around the timing pulley 49. It is hung (see FIGS. 10 to 12). The timing belt 50 is also wound around an idler pulley 56 provided on the back side in the longitudinal direction so that the belt portion is parallel to the guide shaft 45, and the array probe 44 is stopped in the middle. by attached adapted to move the same amount as the array probe 44 (see FIGS. 10 and 11). Therefore, in the array probe holder unit 4 of the present embodiment, the timing belt 50 is fed by driving the driving motor 46, and the array probe 44 fastened to the timing belt 50 is elongated along the guide shaft 45. It can be moved in the direction. Further, it is possible to be caused to reverse the drive motor 46 to move the array probe 44 in the opposite direction.

  In addition, brackets 54 and 55 are provided on the right and left frames 52 and 53 of the array probe holder unit 4 (see FIGS. 11 and 12, etc.). The brackets 54 and 55 can be connected to the connection plate 7 using connection holes 54a and 55a, respectively (see FIG. 1). Further, on the bottom side of these brackets 54 and 55 are casters 42 are attached (see FIG. 13 or the like).

  Next, the TOFD probe holder unit 5 will be described (see FIGS. 16 to 19). The TOFD probe holder unit 5 is a device for identifying the position of a crack defect in a structural material that is a flaw detector, one being a pair of TOFD that functions as a transmitting probe and the other as a receiving probe. Probes 57 and 58 are provided. In the present embodiment, a guide shaft 59 composed of a pair of round bars parallel to each other is provided in the TOFD probe holder unit 5, and both the TOFD probes 57 and 58 are arranged along the guide shaft 59. Alternatively, one can move linearly (see FIG. 17). Since the guide shaft 59 in this case is provided along the longitudinal direction (the axial direction of the tubular structure 2), the TOFD probes 57 and 58 of the present embodiment are movable in the longitudinal direction. Therefore, after the TOFD probe holder unit 5 is moved in the circumferential direction by the drive unit 3 described above and stopped, the TOFD probes 57 and 58 can be moved in the longitudinal direction to perform ultrasonic flaw detection. It has become. A scale plate 60 is provided in the vicinity of the TOFD probes 57 and 58 so as to be parallel to the guide shaft 59 (see FIG. 17). For example, the scale plate 60 of this embodiment has a scale at the center position in the longitudinal direction of 0, and the distance from the center position to the TOFD probes 57 and 58 can be known.

  In addition, brackets 63 and 64 are provided on the left and right frames 61 and 62 of the TOFD probe holder unit 5, respectively (see FIGS. 15 to 18). The brackets 63 and 64 can be connected to the connection plate 7 using connection holes 63a and 64a, respectively (see FIG. 1). Further, on the bottom side of these brackets 63 and 64 are casters 42 are attached (see FIG. 15 and the like).

  The guide carriage unit 6 is a member that constitutes the annular automatic ultrasonic flaw detector 1 by being connected to the drive unit 3, the array probe holder unit 4, the TOFD probe holder unit 5, or the connection plate 7 described above. For example, the guide carriage unit 6 in the present embodiment is configured by a rectangular plate and casters 42 disposed at the four corners of the bottom surface of the plate (see FIGS. 1 and 2). The size and number of installation of the guide carriage unit 6 depend on other devices (the drive unit 3, the array probe holder unit 4, the TOFD probe holder unit 5 and the like) and the size of the tubular structure 2 to be inspected. As an example, the embodiment of the present embodiment will be described. Here, three guide carriage units 6 are prepared, and six units including casters 42 (that is, one drive unit). 3, one array probe holder unit 4, one TOFD probe holder unit 5, and three guide carriage units 6) are arranged at equal intervals of 60 degrees (see FIG. 1). . When the units 3 to 6 are arranged at equal intervals in this way, the rolling resistance of the casters 42 is appropriately dispersed, and the units 3 to 6 are rotated more smoothly around the tubular structure 2. It is preferable in that it can be made to occur.

  The connection plate (connection member) 7 is a member for connecting the units 3 to 6 described above (see FIGS. 1 and 2). In constructing the automatic ultrasonic flaw detector 1, each of the above-described units 3 to 6 can be directly connected. In this embodiment, the connecting plate 7 is interposed between the units 3 to 6 to form an annular shape. The automatic ultrasonic flaw detector 1 is configured. When the connecting plate 7 is interposed between the units 3 to 6 as described above, the number of movable points (connecting points) increases accordingly, so that the automatic ultrasonic inspection having a shape along the peripheral surface of the tubular structure 2 is performed. The apparatus 1 can be configured. Further, the connecting plate 7 (or the guide carriage unit 6 described above) may be attached or detached as necessary, or the size of the connecting plate 7 or the like (more specifically, the length in the circumferential direction) may be changed. It is preferable to interpose the connecting plate 7 also from the viewpoint that it can be easily applied to the tubular structures 2 having different sizes. This increases the flexibility in applying the automatic ultrasonic flaw detector 1 and expands the application range. . Furthermore, in consideration of the size and weight of the other units 3 to 6, the lengths of the individual connection plates 7 may be varied as necessary. In this embodiment, the length of the five connecting plates 7 with respect to the annular structure 2 having an outer shape of 610 mm is set in the counterclockwise order from the array probe holder unit 4 in this embodiment. each 160mm, 190mm, 170mm, 170mm, is made different so that 190 mm (see Fig. 1). For example, the array probe holder unit 4 and the TOFD probe holder unit 5 operate while bringing their respective probes (array probe 44, TOFD probes 57, 58) into contact with the outer peripheral surface of the tubular structure 2. In such a case, the automatic ultrasonic flaw detector 1 operates more smoothly if the size of each connecting plate 7 is appropriately changed in this way, and the overall weight balance is taken into consideration by taking the sliding resistance into consideration. It becomes possible.

  Further, the connecting plate 7 of the present embodiment includes a connecting hole 7a for attaching a hinge, and is connected to the adjacent units 3 to 6 through a connecting jig 43 attached to the connecting hole 7a. It has a structure. The connecting jig 43 can be bent or is flexible enough to be bent, so that it can be applied to tubular structures 2 having different sizes. For example, in this embodiment, a hinge is used as the connecting jig 43, but other jigs may be used. Moreover, in this embodiment, it is supposed that this connection plate 7 is arrange | positioned so that it may become equal intervals between each units 3-6. However, one of these connecting plates 7 is replaced with a device fastening member 8 so that the circumferential length of the automatic ultrasonic flaw detector 1 can be adjusted (see FIG. 1). In the above description, the name “connecting plate” is used, but this is a convenient name resulting from the fact that the member is plate-shaped, and is merely a preferred example of the connecting member. Therefore, for example, a rod-shaped member corresponds to the “connecting member” in the present invention as long as it functions in the same manner as described above.

  The device fastening member 8 is provided in the middle of the automatic ultrasonic flaw detector 1 configured in an annular shape, and is a member for adjusting the circulation length by appropriately tightening (see FIG. 1). The specific structure of the device fastening member 8 is not particularly limited as long as the circumferential length can be appropriately changed. For example, in this embodiment, four plate-like members 8a to 8d are connected in the circumferential direction. At the same time, the two central portions 8b and 8c are bent into an inverted V shape, and the two plate-like members 8b and 8c are bent with adjustment bolts 8e (see FIG. 1). Although not shown in detail, the two nuts that receive the adjusting bolt 8e are rotatably attached to the plate-like members 8b and 8c, and always change even if the angle of the plate-like members 8b and 8c changes. The adjustment bolt 8e is oriented in the axial direction. Needless to say, the two nuts have internal threads that are opposite to each other, or one of them has no internal thread and only allows rotation of the bolt.

  As described above, the track timing belt 9 is a toothed belt having teeth on its outer peripheral side, and is installed so as to go around the outer periphery of the tubular structure 2 to be a track of the drive timing pulley 10. . For example, in this embodiment, a flexible orbit timing belt 9 made of reinforced rubber is employed, and this is wound around the outer periphery of the tubular structure 2 (see FIGS. 1 and 2). The belt itself has a structure provided with teeth by forming a concavo-convex shape in which crests and troughs are periodically repeated (see FIG. 20). A belt winding timing pulley 71 having a ratchet mechanism is attached to the end of the track timing belt 9. On the outer peripheral surface of the belt winding timing pulley 71, a convex portion is formed for engaging with and engaging with the orbital timing belt 9 having an uneven shape (see FIGS. 21 and 22). Further, a guide adapter 72 for feeding the track timing belt 9 and meshing with the belt winding timing pulley 71 is provided so as to face the outer peripheral surface of the belt winding timing pulley 71 (see FIG. 20). A belt tightening wrench hole 73 for rotating the belt winding timing pulley 71 itself is provided on a side portion of the belt winding timing pulley 71. Therefore, first, the end of the track timing belt 9 is inserted between the belt winding timing pulley 71 and the guide adapter 72, and the belt winding timing pulley 71 is rotated by the wrench inserted into the belt tightening wrench hole 73. Thus, the track timing belt 9 can be gradually wound, and the track timing belt 9 can be wound in close contact with the outer periphery of the tubular structure 2. In this case, since the belt winding timing pulley 71 can be rotated only in one direction by the ratchet mechanism, once the track timing belt 9 is tightened, the belt does not loosen unless the ratchet mechanism is released. ing. The belt winding timing pulley 71 and the guide adapter 72 are supported by frames 74 on both sides thereof (see FIG. 22). Further, when attaching the track timing belt 9 to the end portion of the belt winding timing pulley 71, it is preferable to interpose an urging member therebetween. For example, in this embodiment, a belt mounting bracket 75 is attached to the end portion of the track timing belt 9, and a biasing member 76 incorporating a compression coil spring 76 a is attached to the belt mounting bracket 75, and this biasing member 76 is attached to the frame 74. (See FIGS. 20 and 21). In this case, the biasing member 76 pulls and biases the track timing belt 9, and thus acts to prevent the track timing belt 9 wound around the outer periphery of the tubular structure 2 from being relaxed thereafter. Further, when the track timing belt 9 is wound around the outer periphery of the tubular structure 2, even if the belt timing pulley 71 is rotated more and the track timing belt 9 is wound more strongly, the compression coil spring 76a does not move. By being compressed and the length of the urging member 76 extending in the circumferential direction, the track timing belt 9 functions so as not to be subjected to excessive force. A contact bracket 77 is provided on the bottom surface of the frame 74 so as to contact the tubular structure 2 and fix the belt winding timing pulley 71 so as not to move (see FIGS. 20 and 22).

  The above is a case where the belt-winding timing pulley 71 with a ratchet mechanism is employed, but for example, a fastener 78 with an adjustment can be employed as another mechanism (see FIGS. 23 and 24). That is, a fastening member 79 with a hook is attached to one end of the track timing belt 9, and an adjustment fastener 78 provided with a locking member 80 that is hooked on the fastening member 79 with a hook is attached to the other end. It is also possible to use the track timing belt 9 in close contact with the outer periphery of the tubular structure 2 by using it.

  According to the automatic ultrasonic flaw detector 1 of the present embodiment configured by the above members, it is possible to automatically detect a crack defect in the tubular structure 2 to be inspected. That is, the orbital timing belt 9 is first installed around the tubular structure 2, and the annular automatic ultrasonic flaw detector 1 is attached to the outer periphery of the tubular structure 2, and then the automatic ultrasonic flaw detector by the device fastening member 8. 1 is adjusted, and the casters 42 of the units 3 to 6 and the array probe 44 and the TOFD probe 57 are brought into close contact with the outer peripheral surface of the tubular structure 2 (see FIG. 1). Further, the drive timing pulley 10 of the drive unit 3 is engaged with the track timing belt 9 (see FIG. 2). After the installation, when the driving motor 11 is operated, the automatic ultrasonic flaw detector 1 rotates around the tubular structure 2 and starts automatic flaw detection. In addition, when the automatic ultrasonic flaw detector 1 is attached to and detached from the tubular structure 2, it can be easily attached and detached if there are about two workers. It is possible to attach the sonic flaw detector 1 by winding it from the upper part of the tubular structure 2 or to remove it by the reverse operation.

  Incidentally, the arrangement (order of connection) of the units 3 to 6 described above is not particularly limited, and automatic flaw detection can be performed in any connection order. For example, this embodiment Thus, it can be said that it is preferable to dispose the drive unit 3 and the array probe holder unit 4 so as to face each other (ie, at a position 180 degrees apart) (see FIG. 1). For example, when the contact resistance during the operation of the array probe holder unit 4 among the units 3 to 6 is the maximum, the weight in the circumferential direction of the automatic ultrasonic flaw detector 1 can be appropriately dispersed by arranging them in this manner. In addition, since the weight load applied to the drive unit 3 can be reduced, the rotation operation can be made smoother. Alternatively, although not particularly illustrated, relatively heavy units such as the drive unit 3, the array probe holder unit 4, and the TOFD probe holder unit 5 are arranged at regular intervals every 120 ° to automatically It can also be said that it is preferable to balance the overall weight of the ultrasonic flaw detector 1.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the present embodiment, the automatic ultrasonic flaw detector 1 that can perform both the phased array method (PA method) and the TOFD method by providing the array probe holder unit 4 and the TOFD probe holder unit 5 has been described. However, in addition to this, a creeping wave probe, an ordinary single oscillator longitudinal wave and transverse wave oblique angle probe, etc. are used, and the TOFD method, end echo method, tandem flaw detection method, pitch catch, etc. are simultaneously used. You can also perform flaw detection. By the way, the tandem flaw detection method is a flaw detection method in which two oblique angle probes are arranged at the front and rear to detect a defect perpendicular to the flaw detection surface, one for transmission and the other for reception. is there. A creeping wave probe uses a secondary creeping wave that is generated when a transverse wave (wave generated simultaneously with a creeping wave) is reflected from the bottom surface of a pipe or the like, and detects a defect or the like that opens on the inner surface of the pipe. A probe to do.

  In the present embodiment, the automatic ultrasonic flaw detector 1 including two types of probe holder units, the array probe holder unit 4 and the TOFD probe holder unit 5, has been described. This is merely an example. For example, even an automatic ultrasonic flaw detector 1 having only one of the array probe holder unit 4 and the TOFD probe holder unit 5 automatically detects crack defects in the tubular structure 2. Needless to say, flaw detection is possible. In short, it is preferable to have different types of probe holder units, so that it is possible to improve the accuracy of flaw detection, but it is sufficient to perform flaw detection with a single probe holder unit. Is possible.

  Furthermore, in the present embodiment, the automatic ultrasonic flaw detector 1 provided with one array probe holder unit 4 and one TOFD probe holder unit 5 has been described. Of course, it is also possible to add a tentacle holder unit. For example, by removing the guide carriage unit 6 at a certain location and installing the array probe holder unit 4 instead, the automatic ultrasonic flaw detector 1 having a plurality of array probes 44 can be obtained. The same applies to the TOFD probe holder unit 5.

  In the above-described embodiment, it has been described that smooth operation is possible by appropriately changing the size of each connecting plate 7 to balance the weight of the entire apparatus. However, in this case, the size of the connecting plate 7 can be changed. The method includes arranging a plurality of types of connecting plates 7 having different sizes and replacing only necessary portions, and includes extending and contracting the connecting plates 7 themselves to change the length. Here, an example of the latter will be described. As described below, the plate body portion is configured by overlapping two plate-like members (guide plate 65, slide plate 66), and one of them is slid steplessly. Thus, the total length can be changed (see FIGS. 25 to 27). If the both sides 65a of the guide plate 65 are bent, the movement of the slide plate 66, which is the other plate-like member, is restricted so that the guide plate 65 can be relatively moved only in one direction (see FIG. 27). One of the plate-like members (for example, the guide plate material 65) is provided with a long hole 67 along the moving direction, and the other plate-like member (for example, the slide plate 66) is provided with a round hole 68. The threaded portion 69a of the lock handle 69 passes through both the hole 67 and the round hole 68 (see FIG. 25 and the like). Further, a nut member 70 is attached to the screw portion 69a of the lock handle 69 so that the guide plate 65 and the slide plate 66 are sandwiched together with the lock handle 69 (see FIG. 26 and the like). According to the slide type connecting plate 7 as described above, the lock handle 69 and the nut member 70 are usually used to tighten and lock the guide plate 65 and the slide plate 66, while the lock handle 69 is rotated only when necessary. The length of the connecting plate 7 can be freely changed by sliding the slide plate 66 by an arbitrary amount (see FIG. 25 and the like). In addition, since the stepless adjustment is possible and a minute amount of adjustment is possible, it is possible to cope with a case where the outer diameter of the tubular structure 2 is slightly different.

  In the above-described embodiment, the orbital timing belt 9 is wound around the tubular structure 2 and is rotated, and the drive unit 3 is moved along the orbital timing belt 9. If the tubular structure 2 is a tube made of carbon steel, low alloy steel, or the like and can attract a magnet, a caster 42 having magnetism can be used. In such a case, each caster 42 having magnetism is in close contact with the outer periphery of the tubular structure 2, and can move in the circumferential direction without spinning around the outer periphery. The caster 42 magnetized, for example, those comprising a magnet, or the like made of the magnet. In this case, the drive unit 3 may be moved along the track timing belt 9 as in the above-described embodiment, or the drive unit 3 may be used without using the track timing belt 9. It is good also as moving to the circumferential direction in the state which stuck each unit 3-6 including this to the outer periphery.

It is the front view which showed the structure of the automatic ultrasonic flaw detector in embodiment of this invention along the axial direction of a tubular structure. It is a right view of the automatic ultrasonic flaw detector shown in FIG. FIG. 2 is a front view showing the drive unit shown in FIG. 1 upside down. In the drive unit shown in FIG. 3 is a diagram showing a state in which remove the plate of the casing front. FIG. 4 is a left side view of the drive unit shown in FIG. 3. It is the figure (plan view) which showed the shape at the time of seeing the drive unit shown in Drawing 5 from right above (diameter direction outside of a tubular structure). It is sectional drawing of the drive unit in the VII-VII line of FIG. It is sectional drawing of the drive unit in the VIII-VIII line of FIG. It is sectional drawing of the drive unit in the IX-IX line of FIG. It is a left view of the array probe holder unit shown in FIG. It is the figure (plan view) which showed the shape at the time of seeing the array probe holder unit shown in FIG. 10 from right above (diameter direction outer side of a tubular structure). It is sectional drawing of the array probe holder unit in the XII-XII line | wire of FIG. It is sectional drawing of the array probe holder unit in the XIII-XIII line | wire of FIG. It is sectional drawing of the array probe holder unit in the XIV-XIV line | wire of FIG. FIG. 2 is a front view showing the TOFD probe holder unit shown in FIG. 1 in a state where the TOFD probe holder unit is positioned directly above a tubular structure. FIG. 16 is a left side view of the TOFD probe holder unit shown in FIG. 15. It is the figure (plan view) which showed the shape at the time of seeing the TOFD probe holder unit shown in FIG. 16 from right above (diameter direction outer side of a tubular structure). It is a cross-sectional view of TOFD probe holder unit line XVIII-XVIII in FIG. 16. It is sectional drawing of the TOFD probe holder unit in the XIX-XIX line of FIG. It is a figure which shows the structure of the terminal part of a track timing belt, and its periphery. FIG. 21 is a bottom view of the end portion of the track timing belt shown in FIG. 20 and the surrounding structure. FIG. 21 is a left side view of the end portion of the track timing belt shown in FIG. 20 and the surrounding structure. It is a figure which shows another form of the structure of the terminal part of a track timing belt, and its periphery. FIG. 24 is a plan view of the end portion of the track timing belt shown in FIG. 23 and the surrounding structure. It is a top view which shows the other form of a connection member. It is sectional drawing in the XXVI-XXVI line of the connection member shown in FIG. FIG. 26 is a right side view of the connecting member shown in FIG. 25. It is a figure which shows simply the mode of the ultrasonic flaw detection of the thick structure in the past. It is a figure which shows an example of the waveform obtained in the case of the conventional ultrasonic flaw detection. It is a figure which shows simply the mode of the ultrasonic flaw detection of the thick structure in the past. It is a figure which shows a mode that a probe is linearly moved to a longitudinal direction in parallel with a welding line. It is a figure which shows the prior art example of the probe structure which vibrates a single piezoelectric element with a single pulse receiver through a cable, and produces an ultrasonic wave. A plurality of pulse receiver and the piezoelectric element is a diagram illustrating a configuration example of the arrangement to the phased array in one-to-one. It is a figure which shows the phased array method which changes the direction of an ultrasonic beam by shifting the timing of a pulse voltage, and changes a depth of focus, and performs a flaw detection. In FIG. 34, it is a figure which shows simply the mechanism in which the direction of an ultrasonic beam changes by shifting the timing of a pulse voltage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic ultrasonic flaw detector 2 Tubular structure 3 Drive unit 4 Array probe holder unit 5 TOFD probe holder unit 6 Guide carriage unit 7 Connection plate (connection member)
8 Device tightening member 9 Track timing belt 10 Drive timing pulley 11 Drive motor (drive source)
44 Array probe (ultrasonic probe)
57 TOFD probe (ultrasonic probe)
58 TOFD probe (ultrasonic probe)

Claims (2)

An ultrasonic probe capable of moving in the circumferential direction along the outer periphery of a tubular structure to be inspected and for detecting a crack defect generated in the tubular structure, and the ultrasonic probe as the tubular structure A probe holder unit equipped with a drive source and a drive mechanism for reciprocally moving in the axial direction of the structure, and movable in the circumferential direction along the outer periphery of the tubular structure; A drive unit provided with a drive source for driving, a guide carriage unit which is interposed between the drive unit and the probe holder unit and is movable in the circumferential direction along the outer periphery of the tubular structure , and two pieces plate-shaped one of the slide steplessly causes members overlapped circumferential length linked to each other can change the total length is changeable the guide carriage unit of the probe holder unit and the drive uni A connection member that connects adjacent units that intervene at least at any location between the joints, and a device fastening member that can expand and contract in the circumferential direction of the tubular structure, and the probe holder unit, The drive unit, the guide carriage unit, the connecting member, and the device fastening member are connected to each other in the circumferential direction of the tubular structure to form an annular shape, and the probe holder unit and the drive unit sandwich the tubular structure. These are arranged at opposite positions so as to achieve a weight balance, and these travel in the circumferential direction along the outer periphery of the tubular structure, and when this travels or stops, automatic crack defects in the tubular structure are detected. An automatic ultrasonic flaw detector for tubular structures characterized by performing flaw detection.   A track timing belt installed so as to go around the tubular structure, and a drive timing pulley meshing with the track timing belt, and the drive unit is moved by rotating the drive timing pulley by the drive source. The automatic ultrasonic flaw detector for a tubular structure according to claim 1.

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