JP2017075812A - Jig for tandem flaw detection, and tandem flaw detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a jig for tandem flaw detection; to suppress management cost; to perform easily angle adjustment of a holder on which a probe is mounted; and to improve flaw detection accuracy.SOLUTION: A jig for tandem flaw detection used for tandem flaw detection inspection for detecting a steel pipe internal weld flaw includes a plurality of probe holders on which an ultrasonic probe is mounted, and a frame body on which each probe holder is mounted, and is provided with a holder movement mechanism for moving each probe holder on the same arc in a side view of the frame body, and with a holder rotation mechanism for rotating each probe holder in the circumferential direction of the arc.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tandem flaw detection jig and a tandem flaw detection inspection method used when performing a tandem flaw inspection.

  In the manufacturing process of UO steel pipes, flaw detection is performed using various flaw detection methods such as the Longe flaw detection method, the transverse flaw detection method, and the tandem flaw detection method in order to confirm the presence of flaws and weld defects inside the steel pipe. . Generally, flaw detection using a tandem flaw detection method is performed for welding defects such as poor penetration on the seam line.

  As shown in FIG. 1, tandem flaw detection is a method in which outer surface welding and inner surface welding are performed from one of the two ultrasonic probes 51 and 52 (transmitting probe 51). In this flaw detection method, ultrasonic waves UW are transmitted toward the welded portion WP of the steel pipe P, and the ultrasonic waves UW reflected inside the steel pipe are received by the other probe (receiving probe 52). .

  In the example shown in FIG. 1, since a part of the circumferential end surface 53 of the steel pipe P is not sufficiently welded, the ultrasonic wave UW transmitted from the transmitting probe 51 is reflected by the end surface 53 and is reflected. The sound wave UW is reflected by the inner peripheral surface 54 of the steel pipe P, and then the reflected ultrasonic wave UW reaches the reception probe 52. As a result, a peak appears in the ultrasonic wave UW detected by the receiving probe 52, and it can be confirmed that a weld defect exists in the steel pipe P. On the other hand, when there is no poor penetration in the welded portion WP, the ultrasonic wave UW is not reflected by the welded portion WP, and the ultrasonic probe UW is not detected by the receiving probe 52. Thereby, it can be confirmed that there is no welding defect in the steel pipe P.

  Since the reflection angle of the ultrasonic wave inside the steel pipe changes according to the outer diameter and thickness of the steel pipe, when performing a tandem flaw inspection, two super-wavelengths are selected according to the outer diameter and thickness of the steel pipe. It is necessary to arrange the acoustic probe at an appropriate position. However, every time a tandem flaw inspection is performed, it is troublesome for an operator to place an ultrasonic probe according to the outer diameter and thickness of the steel pipe, and there is a possibility that the inspection accuracy varies depending on the skill level of the operator. .

  For this reason, in the conventional tandem flaw inspection, a dedicated jig is prepared for each steel pipe having a different outer diameter and thickness, and the ultrasonic probe is arranged at an optimal position by using this jig.

  In addition, as a jig for tandem flaw detection inspection, there is also a jig described in Patent Document 1, for example. This jig is used for flaw detection of fillet welds between a steel pipe and another member. The holder (holding member) to which the ultrasonic probe is attached is attached to the steel pipe in the longitudinal direction or to the steel pipe. The angle can be adjusted manually.

JP 2004-264122 A

  However, producing a jig for each steel pipe having a different outer diameter or plate thickness requires a production cost and makes the management of the jig complicated. Moreover, when using the jig | tool described in patent document 1, although the flaw detection inspection of the fillet weld part of a steel pipe and another member can be performed, the flaw detection of the weld part on a seam line using the said jig | tool is possible. It is not possible to conduct an inspection.

  Moreover, since the jig | tool described in patent document 1 needs to adjust the angle of the holder (holding member) made to contact | abut to the steel pipe surface manually, the adjustment operation took time and effort. In addition, the holder angle adjusted by the operator may not be the optimum holder angle for properly performing flaw detection inspection. In this case, the flaw detection accuracy of the weld defect is lowered.

  The present invention has been made in view of the above circumstances, and can suppress the production and management costs of a tandem flaw detection inspection jig, and can easily adjust the angle of a holder to which a probe is attached, The purpose is to improve the flaw detection accuracy.

  The present invention for solving the above-mentioned problems is a tandem flaw detection jig used for tandem flaw inspection for flaw detection within a steel pipe, comprising a plurality of probe holders to which an ultrasonic probe is attached, and each probe. And a holder moving mechanism for moving each probe holder on the same arc in a side view of the frame, and rotating each probe holder in the circumferential direction of the arc. And a holder rotation mechanism.

  The jig according to the present invention has a configuration in which each probe holder to which the ultrasonic probe is attached moves on the same arc in a side view of the frame body, and therefore, according to the thickness of the steel pipe to be inspected. Thus, each probe holder can be moved to an optimum position for flaw detection inspection. Further, since each probe holder is configured to rotate in the circumferential direction of the arc, each probe holder automatically rotates when the jig according to the present invention is pressed against the steel pipe. become. Thereby, even for steel pipes having different outer diameters, the angle of each probe holder is automatically adjusted so as to be an optimum angle for flaw detection inspection.

  Another aspect of the present invention is a tandem flaw detection inspection method for flaw detection inside a steel pipe, wherein a plurality of probe holders are attached to a frame, and each probe holder is viewed from the side of the frame. The jig is configured to be movable on the same arc, and each probe holder is configured to be rotatable in the circumferential direction of the arc, and the ultrasonic probe is attached to each probe holder. A jig is brought into contact with the surface of the steel pipe, and each probe holder is moved to a flaw detection position corresponding to the plate thickness of the steel pipe to perform a tandem flaw inspection.

  According to the present invention, a tandem flaw inspection can be carried out with a single jig even if the steel pipes have different external shapes and thicknesses. Thereby, it becomes unnecessary to produce a jig for each steel pipe, and the production cost of the jig can be suppressed. Further, the angle adjustment of the probe holder can be easily performed. At the same time, since the tandem flaw inspection can be performed with the optimum probe arrangement, the flaw detection accuracy can be improved.

It is explanatory drawing about a general tandem flaw inspection. It is a perspective view which shows schematic structure of the jig | tool for tandem flaw detection which concerns on embodiment of this invention. It is a top view which shows schematic structure of the jig | tool for tandem flaw detection which concerns on embodiment of this invention. It is a side view which shows schematic structure of the jig | tool for tandem flaw detection which concerns on embodiment of this invention. It is a top view which shows schematic structure of the rotation holder which concerns on embodiment of this invention. It is a side view which shows schematic structure of the rotation holder which concerns on embodiment of this invention. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. In this figure, the frame 4 is not shown. It is a top view which shows schematic structure of the raising / lowering holder which concerns on embodiment of this invention. It is the top view and side view for demonstrating the tandem flaw detection inspection method which concerns on embodiment of this invention. It is the top view and side view for demonstrating the tandem flaw detection inspection method which concerns on embodiment of this invention. It is the top view and side view for demonstrating the tandem flaw detection inspection method which concerns on embodiment of this invention. It is the top view and side view for demonstrating the tandem flaw detection inspection method which concerns on embodiment of this invention. It is the top view and side view for demonstrating the tandem flaw detection inspection method which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  First, the configuration of the tandem flaw detection jig 1 in this embodiment will be described.

  As shown in FIGS. 2 to 4, the tandem flaw detection jig 1 according to the present embodiment includes a jig main body 2 and an operation reference block 3 with which the jig main body 2 abuts. The jig main body 2 includes a frame body 4 and two probe holders 5. Each member is made of, for example, aluminum.

  The frame body 4 has side walls formed so as to surround four sides with two short plate members and two long plate members, and the upper surface and the lower surface are open. As shown in FIG. 4, the long plate material constituting the frame body 4 is formed to be curved so as to draw an arc in a side view, and an elongated hole 6 is formed along one arc S at the center. Is formed. The curvature of the long hole 6 is appropriately determined based on the outer diameter of each steel pipe P that can be inspected so that the flaw detection inspection of all the steel pipes P that can be inspected can be performed using the jig 1 according to this embodiment. Is set.

  Further, the length of the long hole 6 is appropriately set based on the outer diameters and plate thicknesses of all the steel pipes that can be inspected so that the tandem flaw inspection can be appropriately performed using the probe holder 5 described later. The For example, as shown in FIG. 1, in the tandem flaw detection method, setting is performed by bringing the transmitting probe 51 close to the weld bead, but if the transmitting probe 51 is too close to the weld bead, the incident angle is increased. It will be necessary. In this case, due to the characteristics of the ultrasonic wave, total reflection occurs on the surface of the steel pipe, and flaw detection cannot be performed. Further, if the probe 51 for transmission is set away from the weld bead, the attenuation is increased and the flaw detection ability is deteriorated. Therefore, the length of the long hole 6 of the tandem flaw detection jig 1 in the present embodiment is such that the probe holder is positioned at a position where ultrasonic waves can be appropriately transmitted and received during the tandem flaw detection inspection using the jig 1. 5 is set to be fixed. In addition, it is preferable that the length of the long hole 6 is 30-200 mm. The length of the long hole 6 is the arc length on the central axis of the long hole 6.

  Next, as shown in FIGS. 2 to 4, the probe holder 5 includes a rotary holder 5 a configured to rotate along the arc-shaped elongated hole 6, and a height direction H of the rotary holder 5 a. A lifting holder 5b configured to be movable up and down is provided.

  As shown in FIG. 5, each rotary holder 5a is formed in a substantially concave shape in plan view. As shown in FIGS. 5 and 6, a screw hole is formed in the central portion of one side wall of each rotary holder 5a. 7 is formed. As shown in FIGS. 3 and 4, each rotary holder 5a is disposed inside the frame body 4 so that the concave openings face each other, and the elongated hole 6 of the frame body 4 and the screw hole 7 of the rotary holder 5a. In a state in which the positions are aligned, the position fixing screw 8 is used to fasten the frame 4 from the outside. When the rotary holder 5a is attached to the frame body 4 in this way, the rotary holder 5a is arranged in the circumferential direction C of the elongated hole 6, that is, in the circumferential direction C of the arc S having the radius R, with the position fixing screw 8 as the rotation axis. It can be rotated.

  A rotation stopper 9 for restricting the rotation of the rotation holder 5a is formed at the lower portion of the side wall of the rotation holder 5a. Two rotation stoppers 9 are formed on each side wall so as to protrude in the width direction W of the frame body 4 from the side wall of the rotation holder 5a. When the rotation of the rotation holder 5a is increased, one of the two rotation stoppers 9 hits the lower surface of the frame body 4 and further rotation is suppressed. As shown in FIG. 4, the rotation angle θ of the rotary holder 5a is preferably within ± 15 ° with respect to a plane perpendicular to the arc S on the rotation axis of the rotary holder 5a. That is, it is preferable to provide the rotation stopper 9 at a position that does not exceed this angle.

  As shown in FIGS. 5 and 6, a notch 10 is formed in the upper portion of the side wall facing the side wall provided with the screw hole 7. A bracket screw hole 12 for attaching the bracket 11 (FIG. 3) is formed on the bottom surface of the notch 10.

  Further, as shown in FIG. 7, two guides 13 for guiding the up-and-down movement of the elevating holder 5b, which will be described later, and the uppermost of the elevating holder 5b shown in FIG. A drop stopper 14 that regulates the lower position is provided. As shown in FIGS. 5 to 7, spherical members 15 such as steel balls are provided at the four corners of the bottom surface of the rotary holder 5a. The spherical member 15 is attached to the rotation holder 5a in a rotatable state.

  As shown in FIG. 9, the elevating holder 5b is formed with side walls so as to surround four sides with four plate members, and the upper and lower surfaces are open. An ultrasonic probe (not shown) is attached to the inside of the elevating holder 5b, and the ultrasonic probe moves up and down integrally with the elevating holder 5b. Further, the probe cable 16 (FIG. 2) is connected to an ultrasonic oscillator (not shown) through the upper opening of the elevating holder 5b. The size of the opening of the elevating holder 5b is appropriately determined depending on the shape of the ultrasonic probe to be used.

  Moreover, as shown in FIG. 9, the spring receiving part 17 formed so that it might protrude from a side wall is provided in the outer surface of one side wall of the raising / lowering holder 5b. As shown in FIG. 8, the spring receiving portion 17 is formed so as to extend along the height direction H of the rotary holder 5a. The elevating holder 5b is inserted inside the rotary holder 5a so that the spring receiving portion 17 is positioned between the guides 13 (FIG. 7) of the rotary holder 5a, and then the bracket is attached to the notch 10 of the rotary holder 5a. When 11 is fastened, the elevating holder 5b is attached to the rotating holder 5a.

  One end of a spring 18 as an example of an elastic member is attached to the upper surface of the spring receiving portion 17 of the elevating holder 5b, and the other end of the spring 18 is attached to the lower surface of the bracket 11 of the rotary holder 5a. By adopting a configuration in which the spring 18 is interposed between the rotary holder 5a and the elevating holder 5b in this way, when the jig body 2 is pressed against the steel pipe P, the elevating holder 5b moves upward and the spring 18 is moved. Will shrink. And the force which moves the raising / lowering holder 5b below by the elastic force of the spring 18, ie, the force which presses the raising / lowering holder 5b against the steel pipe P generate | occur | produces. Thereby, generation | occurrence | production of the incident defect etc. of the ultrasonic wave to the steel pipe P resulting from the raising of the raising / lowering holder 5b can be prevented.

  On the other hand, when the jig 1 pressed against the steel pipe P is separated from the steel pipe P, the elevating holder 5b moves downward due to its own weight, but the lower surface of the spring receiving portion 17 of the elevating holder 5b is the rotating holder 5a. The lowering movement of the elevating holder 5b is restricted by contacting the drop stopper 14 of the elevating holder 5b. That is, the lifting holder 5b can be prevented from dropping when the jig 1 is lifted.

  Further, since the elevating holder 5b moves up and down while the spring receiving portion 17 of the elevating holder 5b is along the guide 13 of the rotating holder 5a, the elevating holder 5b is inclined with respect to the height direction H of the rotating holder 5a. The movement is eliminated, and the lifting holder 5b can be brought into contact with the steel pipe P at an appropriate angle.

  The spring 18 is a presser spring provided so that the probe is stably perpendicular to the surface of the steel pipe. In the state where the upper surface of the drop stopper 14 of the rotating holder 5a and the lower surface of the spring receiving portion 17 of the elevating holder 5b are in contact, the protruding length of the elevating holder 5b protruding from the lowermost surface of the rotating holder 5a is 3 to 10 mm. It is preferable that In the present embodiment, the “lowermost surface of the rotating holder 5 a” refers to a plane including the lowest points of the four spherical members 15. On the other hand, when the spherical member 15 is not provided, the bottom surface of the rotary holder 5a is the bottom surface.

  As shown in FIG. 9, a liquid passage port 19 through which a liquid such as water passes is provided on the side wall of the elevating holder 5b. The liquid passage port 19 is formed so as to penetrate the plate material constituting the side wall of the elevating holder 5b in the vertical direction. A liquid supply nozzle (not shown) for supplying a liquid such as water is connected to the liquid passage port 19. Only one liquid passage port 19 may be used, or a plurality of liquid passage ports 19 may be used simultaneously by connecting a liquid supply nozzle (not shown) to the plurality of liquid passage ports 19. Further, for example, when one liquid passage port 19 is used, when a problem occurs in the liquid passage port 19, by providing a plurality of liquid passage ports 19 as in the present embodiment, Since another liquid passage port 19 can be used, even if a failure occurs in one liquid passage port 19, one jig 1 can be used as it is.

  As shown in FIGS. 4 and 8, a wear-resistant member 20 such as ceramic is provided on the bottom surface of the elevating holder 5b. As a result, it is possible to prevent the bottom surface of the lifting / lowering holder 5b from being worn when the probe holder 5 (the rotating holder 5a and the lifting / lowering holder 5b) described later is moved.

  The operation reference block 3 shown in FIG. 2 is a substantially rectangular parallelepiped member. The operation reference block 3 is placed on the steel pipe P so that its longitudinal direction is along the seam line SL of the steel pipe P, and is used so that the end face in the circumferential direction C of the frame body 4 is brought into contact with the operation reference block 3. The The lower part of the operation reference block 3 has a stepped shape, and when the operation reference block 3 is placed so as not to overlap the seam line SL, a contact surface with the frame body 4 (hereinafter referred to as “reference surface”). ) Protrudes toward the seam line SL. Further, a magnet (not shown) is attached to the lowermost surface of the operation reference block 3, and the operation reference block 3 placed on the steel pipe P is fixed by the magnet. The magnet may be incorporated in the operation reference block 3.

  The tandem flaw detection jig 1 is configured as described above. Next, a tandem flaw detection inspection method for steel pipe welds using the tandem flaw detection jig 1 will be described. Note that the tandem flaw detection inspection in the present embodiment is performed using a water immersion method.

  Moreover, it is preferable that the plate | board thickness of the steel pipe P made into a test object is 5-50 mm. A more preferable range is 6.4 to 40 mm. Moreover, it is preferable that the outer diameter of the steel pipe P is 15-60 inches (355-1524 mm). A more preferable range is 18 to 56 inches (457 to 1423 mm). Moreover, it is preferable that the ultrasonic frequency of the probe used for flaw detection is 1 to 10 MHz. A more preferable range is 2 to 5 MHz.

  First, as shown in FIG. 10, the operation reference block 3 is placed on the surface of the steel pipe along the seam line SL of the steel pipe P. At this time, the operation reference block 3 is placed so that the reference surface is positioned above the seam line SL in a side view. As shown in FIG. 10B, at this stage, the jig body 2 is not in contact with the steel pipe P, and each probe holder 5 is rotated by the weight of the elevating holder 5b. The upper surface of the drop stopper 14 is in contact with the lower surface of the spring receiving portion 17 of the elevating holder 5b.

  Next, as shown in FIG. 11, the jig body 2 is pressed against the surface of the steel pipe. At this time, each rotation holder 5a rotates about the position fixing screw 8 as a rotation axis, and each rotation holder 5a rotates until each of the four spherical members 15 provided on each rotation holder 5a comes into contact with the steel pipe surface. To do. Thereby, each probe holder 5 will contact | abut to the steel pipe P in the state which became the optimal angle for implementing a flaw detection test.

  At this time, the wear-resistant member 20 provided on the bottom surface of the lifting / lowering holder 5b comes into contact with the surface of the steel pipe, so that the lifting / lowering holder 5b moves upward, and a spring interposed between the lifting / lowering holder 5b and the rotating holder 5a. 18 (FIG. 8) is in a contracted state. Thereby, the raising / lowering holder 5b will be in the state pressed against the steel pipe P. FIG.

  Subsequently, as shown in FIG. 12, the jig main body 2 is moved in a state where the jig main body 2 is pressed against the steel pipe P, and is brought into contact with the operation reference block 3. At this time, when the spherical member 15 of each rotation holder 5a rotates, the jig body 2 moves so as to slide on the steel pipe surface. That is, by providing the spherical member 15, it is possible to prevent the wear of the bottom surface of the rotary holder and to move the jig body 2 without damaging the steel pipe P. Further, while the jig body 2 is moving, the bottom of each lifting / lowering holder 5b moves while being rubbed against the steel pipe P, but each wear-resistant member 20 provided on the bottom of each lifting / lowering holder 5b allows each Wear on the bottom surface of the elevating holder 5b can be prevented.

  Subsequently, as shown in FIG. 13, each probe is performed as necessary so that the ultrasonic transmission position and the reception position of the ultrasonic probe (not shown) are optimal positions for performing the flaw detection inspection. The child holder 5 (the rotation holder 5a and the elevating holder 5b) is moved. Then, after moving each probe holder 5, the position fixing screw 8 is tightened to fix the positions of the two probe holders 5.

  Thereafter, water is continuously supplied from the liquid passage port 19 of each rotary holder 5a, and the gap between the ultrasonic probe (not shown) attached to each elevating holder 5b and the steel pipe surface is filled with water. By transmitting ultrasonic waves in this state, a tandem flaw detection test using a water immersion method can be performed. At this time, since each probe holder 5 has an optimum angle for performing the flaw detection inspection, it is possible to perform the flaw detection inspection with high accuracy.

  Subsequently, as shown in FIG. 14, the jig body 2 is moved along the seam line SL while the jig body 2 is pressed against the operation reference block 3. Thereby, the flaw detection inspection of a steel pipe welding part can be implemented continuously.

  The tandem flaw detection inspection according to the present embodiment is performed as described above. In addition, after the completion of the flaw detection inspection, when the flaw detection inspection of the steel pipe P having different outer diameters and plate thicknesses is subsequently performed, the flaw detection inspection may be performed by the same procedure as that shown in FIGS. good.

  For example, even if the outer diameter of the steel pipe P to be inspected next is different from the outer diameter of the steel pipe P that has been subjected to the flaw detection inspection immediately before, the probe holder 5 is configured to rotate. When the jig body 2 is pressed against the steel pipe P, the probe holder 5 is automatically adjusted to an optimum angle for carrying out a flaw detection inspection. Further, even when the plate thickness of the steel pipe P to be inspected next is different from the plate thickness of the steel pipe P subjected to the flaw detection inspection immediately before, the probe holder 5 moves on the same arc. Therefore, the transmission position and reception position of the ultrasonic wave can be adjusted to the optimum positions according to the plate thickness of the steel pipe P.

  That is, according to the present embodiment, it is possible to perform flaw detection inspection with a single jig for steel pipes P having different outer diameters and plate thicknesses. Thereby, it becomes unnecessary to produce a dedicated jig for each steel pipe P, and the production cost of the jig 1 can be suppressed. Further, the angle of the probe holder 5 can be easily adjusted, and the flaw detection accuracy can be improved.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above embodiment, the spherical member 15 is provided on the bottom surface of the rotary holder 5a. However, the wear of the rotary holder 5a can be ignored, and scratches on the steel pipe P are not particularly problematic in terms of product quality. If so, the spherical member 15 may not be provided. Similarly, the wear-resistant member 20 of the lifting holder 5b may not be provided.

  In the above embodiment, the water supplied between the ultrasonic probe and the surface of the steel pipe is supplied via the liquid passage port 19, but a liquid such as water is supplied from another path. Also good. Further, the flaw detection inspection may be performed by directly applying the ultrasonic probe to the steel pipe P without using the water immersion method.

  In the above-described embodiment, the operation reference block 3 is provided separately from the jig main body 2, and the jig main body 2 is moved along the seam line SL while the jig main body 2 is in contact with the operation reference block 3. However, the operation reference block 3 may not be provided. However, when the jig body 2 is moved along the seam line SL, the jig body 2 may be displaced in the circumferential direction of the steel pipe, and the transmission position and the reception position of the ultrasonic probe may be shifted. In order to prevent this, it is preferable to provide the operation reference block 3.

  Further, in the above embodiment, the arcuate long holes 6 are provided on the side surfaces of the frame body, and the rotary holders 5a are screwed from the outside of the frame body 4 so that each rotary holder 5a has the same arc S along the long holes 6. Although it is configured to move the top, the movement of the rotary holders 5a on the same arc is not limited to this configuration. Similarly, the configuration for rotating each rotary holder 5a in the circumferential direction C of the long hole 6 is not limited to the configuration described in the above embodiment. That is, a holder moving mechanism for moving each rotary holder 5a attached to the frame body 4 on the same arc in a side view of the frame body 4, and a holder for rotating each rotary holder 5a along the circumferential direction C of the arc If it has a rotation mechanism, the effect demonstrated by the said embodiment can be enjoyed. Similarly, the configuration for moving the lifting holder 5b up and down is not limited to that described in the above embodiment.

  Moreover, in the said embodiment, although the probe holder 5 was comprised with the rotation holder 5a and the raising / lowering holder 5b, the raising / lowering holder 5b does not need to be provided. Even in this case, if the rotary holder 5a attached to the frame 4 is configured to be rotatable, the rotary holder 5a can be rotated when the jig body 2 is pressed against the steel pipe P. . When the lifting holder 5b is not provided, an ultrasonic probe is attached to the rotating holder 5a.

  However, by adopting a configuration in which the probe holder 5 is pressed against the steel pipe P using an elastic member such as the spring 18, the probe holder 5 can be prevented from being lifted due to hand shake or the like of the operator. It is preferable to provide the elevating holder 5b described in the embodiment.

  The present invention can be applied to tandem flaw inspection of weld defects in UO steel pipes.

DESCRIPTION OF SYMBOLS 1 Tandem flaw detection jig 2 Jig body 3 Operation reference block 4 Frame 5 Probe holder 5a Rotating holder 5b Lifting holder 6 Long hole 7 Screw hole 8 Position fixing screw 9 Rotation stopper 10 Notch 11 Bracket 12 Bracket screw Hole 13 Guide 14 Drop stopper 15 Spherical member 16 Probe cable 17 Spring receiving portion 18 Spring 19 Liquid passage port 20 Abrasion resistant member C Circumferential direction H Rotating holder height direction P Steel pipe R Radial direction S Circular arc SL Seam line W Frame Body width direction θ Rotation angle

Claims (22)

A tandem flaw detection jig used for tandem flaw inspection for flaw detection within a steel pipe,
A plurality of probe holders to which ultrasonic probes are attached;
And a frame to which each probe holder is attached,
A holder moving mechanism for moving each probe holder on the same arc in a side view of the frame,
A tandem flaw detection jig having a holder rotation mechanism that rotates each probe holder in the circumferential direction of the arc.   The tandem flaw detection jig according to claim 1, wherein an arc-shaped long hole is formed in the frame body, and the frame body and each probe holder are screwed together through the long hole.   The tandem flaw detection jig according to claim 1, wherein a plurality of spherical members are provided on a bottom portion of the probe holder.   The tandem according to any one of claims 1 to 3, wherein the probe holder is provided with a liquid passage port through which a liquid supplied between the ultrasonic probe and the steel pipe passes. Flaw detection tool.   The tandem testing jig according to any one of claims 1 to 4, wherein the probe holder is provided with a rotation stopper formed so as to protrude in the width direction of the frame.   The tandem flaw detection jig according to any one of claims 1 to 5, wherein a wear-resistant member is provided on a bottom surface of the probe holder.   The jig | tool for a tandem flaw detection as described in any one of Claims 1-6 which has an operation reference block provided with a magnet. The probe holder is
A rotating holder configured to be rotatable in the circumferential direction of the arc;
An elevating holder configured to be movable in the height direction of the rotating holder,
The lifting holder is attached to the rotating holder with an elastic member interposed between the rotating holder and the lifting holder so that an elastic force is generated along the lifting direction of the lifting holder,
The tandem flaw detection jig according to any one of claims 1 to 7, wherein the ultrasonic probe is attached to the lift holder.   The tandem flaw detection jig according to claim 8, wherein a guide for guiding the lifting movement of the lifting holder is provided.   The plate | board thickness of the said steel pipe is a jig | tool for a tandem flaw detection as described in any one of Claims 1-9 which is 5-50 mm.   The tandem flaw detection jig according to any one of claims 1 to 10, wherein an outer diameter of the steel pipe is 15 to 60 inches. A tandem flaw detection method for flaw detection inside a steel pipe,
Multiple probe holders are attached to the frame, and each probe holder is configured to be movable on the same arc in the side view of the frame, and each probe holder is rotated in the circumferential direction of the arc. Using a jig that can be configured,
The jig with the ultrasonic probe attached to each probe holder is brought into contact with the surface of the steel pipe,
A tandem flaw detection method for performing a tandem flaw inspection by moving each probe holder to a flaw detection position corresponding to the thickness of the steel pipe.   An arc-shaped long hole is formed in the frame, and a tandem flaw detection inspection is performed using the jig in which the frame and each probe holder are screwed together through the long hole. The tandem flaw detection method described in 1.   The tandem flaw detection method according to claim 12 or 13, wherein a plurality of spherical members are provided at the bottom of the probe holder to perform a tandem flaw detection inspection.   The tandem flaw inspection is carried out by providing a liquid passage for allowing liquid supplied between the ultrasonic probe and the steel pipe to pass through the probe holder. The tandem flaw detection method described in 1.   The tandem flaw detection method according to any one of claims 12 to 15, wherein the probe holder is provided with a rotation stopper formed so as to protrude in the width direction of the frame body to perform a tandem flaw inspection.   The tandem flaw detection method according to any one of claims 12 to 16, wherein a wear-resistant member is provided on a bottom surface of the probe holder to perform a tandem flaw inspection. An operation reference block including a magnet is placed on the steel pipe so that the longitudinal direction thereof follows the seam line of the steel pipe,
A circumferential end surface of the frame is brought into contact with the operation reference block;
The tandem inspection according to any one of claims 12 to 17, wherein a tandem flaw detection inspection is performed while moving the jig along the seam line in a state where the frame body is in contact with the operation reference block. Inspection method. A rotating holder configured so that the probe holder is rotatable in a circumferential direction of the arc;
An elevating holder attached to the rotating holder and configured to be movable in a height direction of the rotating holder;
An elastic member is interposed between the rotary holder and the lifting holder so as to generate an elastic force along the lifting direction of the lifting holder,
The tandem flaw detection method according to any one of claims 12 to 18, wherein a tandem flaw detection inspection is performed by pressing the jig having the ultrasonic probe attached to the lifting holder against the surface of the steel pipe.   The tandem flaw detection method according to claim 19, wherein the jig is provided with a guide for guiding the lifting movement of the lift holder to perform a tandem flaw inspection.   The tandem flaw inspection method according to any one of claims 12 to 20, wherein a tandem flaw inspection is performed on the steel pipe having a plate thickness of 5 to 50 mm.   The tandem flaw inspection method according to any one of claims 12 to 21, wherein a tandem flaw inspection is performed on the steel pipe having an outer diameter of 15 to 60 inches.

Images