JP2005241285A - Inspection device for detecting flaw in narrow part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow an inspection head to smoothly access a region to be inspected of an interstice, in a double tube composed of an outside cylinder and an inside cylinder. <P>SOLUTION: An inspection device, for inspecting the region to be inspected in the inside cylinder part, by hoisting, lowering and rotating the inspection head 7 in the interstice of the double tube between the outside cylinder part, and the inside cylinder part 88 is equipped with a hoisting and lowering drive component 5 placed on a fixed board 4, base plates 59 and 75 which are hoisted and lowered by the drive of the component 5, an ascending/descending table 1 which ascends and descends, in connection with the base plates 59 and 75, a rotation drive component 6 placed on the base plates 59 and 75, a ring orbit 2 held on the ascending/descending table 1 so that it can rotate freely and the inspection head 7 mounted on the ring orbit 2 via an inspection arm 3. The ascending/descending table 1 and the ring orbit 2 are hoisted and lowered in the interstice of the double tube through the ascent and the descent by the component 5, and the ring orbit 2 is rotated through the rotation of the component 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inspection apparatus that performs an inspection by remotely inserting an inspection head into a narrow portion, and in particular, can perform a flaw detection by inserting an inspection head into a gap between an inner cylindrical portion and an outer cylindrical portion of a double cylindrical structure. The present invention relates to the inspection apparatus.

  The improved boiling water reactor (ABWR) can be re-used by installing a recirculation pump installed outside the conventional boiling water reactor (BWR) inside the reactor as an internal pump (RIP). Circulation piping is deleted to improve reliability and reduce exposure during inspection. A plurality of internal pumps are attached to the outer peripheral portion of the lower end plate 86.

  FIG. 11 is a cross-sectional view showing the structure of the mounting portion between the internal pump and the lower end plate in the prior art. In FIG. 11, a RIP nozzle 92 is attached to the outer periphery of the lower end plate 86, and a RIP casing 88 is formed outside an internal pump (not shown). The RIP nozzle 92 has a double-pipe structure in which an upper portion is formed of an inner cylinder 106 on an outer cylinder 105, and a RIP casing 88 is attached to a lower end portion of the inner cylinder 106. A double tube gap 90 exists between the outer cylinder 105 and the inner cylinder 106.

  Since the RIP nozzle 92 and the RIP casing 88 are attached by welding, when inspecting the RIP welded portion 89, the inspection head is caused to enter from the skirt opening 93 and pass through the double tube gap portion 90. Therefore, it is necessary to access the RIP welded portion 89 to perform inspection. In addition, the RIP casing 88 is provided with a steadying portion 94 so as to be in contact with the inner surface of the outer cylindrical portion 105 of the RIP nozzle 92 in order to suppress horizontal shaking that occurs during an earthquake or the like.

As an apparatus for inspecting the welded portion in the gap between the double pipes as described above, an inspection apparatus as shown in Patent Document 1 has been proposed. This inspection device is provided with an inspection head elevating part in a swivel ring that does not move up and down, and the inspection head is moved up to the welded part by driving this elevating part, and the inspection head is scanned by filling water above the swivel ring. The welded portion is inspected.
JP2000-304887

  However, in the conventional technology as shown in Patent Document 1, the problem will be described with reference to FIG. 11. When inspecting the RIP welded portion 89, the inspection head is made to enter from the skirt opening portion 93 and the double tube gap portion is introduced. Since it is necessary to perform inspection by accessing the RIP welding part 89 through 90, the mechanism part of the narrow double pipe gap 90 must be made compact, in which case the strength and inspection head There exists a subject that the rigidity calculated | required by positioning of this falls.

  Further, when there is an attachment error at the center position of the outer cylindrical portion 105 and the inner cylindrical portion 106 of the double pipe, there is a problem that it is difficult for the inspection apparatus to smoothly access the RIP welded portion 89 and perform the inspection. Further, when the inspection head is scanned with water filled above the swivel ring, it is necessary to use a sealed structure so that water does not flow out to the skirt opening 93 or the lower part of the swivel ring.

  An object of the present invention is to smoothly access an inspection head to an inspection site in a narrow double tube gap formed by an outer cylinder and an inner cylinder, and press the inspection head against the inspection site to contact a medium (eg, water). ) Is supplied and filled, and an inspection apparatus capable of expanding the inspection range as necessary at the same setting location of the inspection apparatus is provided.

In order to solve the above problems, the present invention mainly adopts the following configuration.
An inspection apparatus for inspecting a portion to be inspected of the inner cylindrical portion by moving the inspection head up and down in a double tube gap formed between the outer cylindrical portion and the inner cylindrical portion,
A lift drive unit installed on a fixed substrate, a base plate that moves up and down by driving the lift drive unit, a lift table that moves up and down in connection with the base plate, a rotation drive unit provided on the base plate, and the lift table A ring raceway that is rotatably held on the ring raceway, and an inspection head attached to the ring raceway via an inspection arm,
Ascending and descending the lifting table and the ring raceway in the double pipe gap by raising and lowering by the raising and lowering drive unit, and rotating the ring orbit by rotation of the rotation drive unit,
The inspection head is configured to move up and down and rotate along the gap between the double tubes.

  Further, in the inspection apparatus, an opening having a predetermined height is provided in the outer cylindrical portion, the rotation driving portion that rotationally drives the ring track is disposed in the opening, and a distance between a lower end and an upper end of the opening. The lower limit and the upper limit of the lifting and lowering of the rotation drive unit are defined.

  In the inspection apparatus, the base plate includes an upper base plate and a lower base plate, and a slide table movable on a plane is interposed between the upper and lower base plates. And the ring orbit is made to follow the shape of the double gap.

  In the inspection apparatus, the inspection head includes a probe having a vibrator that generates a vibration wave, a shoe for disposing the probe opposite to the inner cylindrical portion, and a contact that propagates the vibration wave. A supply port for supplying a medium, and a space surrounded by the shoe, the probe, and the inner cylindrical portion is filled with the contact medium.

  According to the present invention, the RIP welded portion can be inspected by inserting the minimum necessary mechanism portion and inspection head into the double pipe gap portion constituted by the RIP nozzle and the RIP casing.

  Further, since the driving part of the inspection head can be provided outside the gap between the double pipes, it is possible to improve the strength of the driving part and improve the maintainability.

  Further, even if the position of the cylindrical portion is changed with respect to the drive portion, the inspection head can be operated with the cylindrical surface as a guide, so that the core adjustment work between the RIP nozzle and the RIP casing and the drive device can be reduced. The inspection head can stably perform the inspection.

  Further, since the inspection head can be pushed to the outside of the RIP casing by projecting to the inside of the RIP nozzle, the inspection can be performed in a state where the distance between the inspection head and the inspection surface is kept constant.

  Further, since the contact medium is directly supplied from the inspection head to the probe, the contact medium can be supplied efficiently.

  Further, by arranging a plurality of inspection heads, a necessary inspection range can be carried out by a single flaw detection scan of the driving device.

  An inspection apparatus according to an embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a perspective view showing an entire structure having an inspection apparatus according to an embodiment of the present invention and a double pipe gap to be inspected, and FIG. 2 is a lifting drive unit and a rotation drive part in the inspection apparatus according to the present embodiment. FIG. 3 is a perspective view showing the structure of the XY slide table, and FIG. 3 is a view showing the lifting table, the ring track, and their connecting structure in the inspection apparatus according to the present embodiment. 4 is a diagram showing the entire structure of the inspection arm and the inspection head provided on the ring track, and FIG. 5 is a diagram showing the structure of the probe in the inspection head.

  1 and 2, the inspection apparatus according to this embodiment includes a ring-shaped lifting table 1 disposed on the outer periphery of an inner cylindrical portion 106 that forms an internal pump (RIP) casing 88, and the lifting table 1. Attached to the RIP nozzle 92 using a ring track 2 held rotatably, an inspection arm installed on the ring track 2 with an inspection head 7 attached to the tip side, and a screw hole provided below the RIP nozzle 92 Inspection device mounting base 4, elevating drive unit 5 installed on inspection device mounting base 4, XY slide table 8 for holding elevating drive unit 5 movably on a plane, and rack provided on ring track 2 44 and a rotation drive unit 6 for rotating the ring raceway 2 by meshing with the gear B76, and an inspection head 7 mounted on the inspection arm 3.

  In FIG. 3, the lifting table 1 is a split-type ring-shaped plate that is inserted from the skirt opening 93, and is connected to each other with bolts while being dividedly inserted from the skirt opening 93 to form a ring shape. . Further, the elevating table 1 has an inner circumference having a circumferential surface of the RIP casing 88 and a small roller 31 for reducing sliding resistance of the inner circumference of the elevating table 1 when the elevating table 1 is raised and lowered. A conical roller 33 for stably running on the taper of the steady rest portion 94 is disposed on the lower surface, and a claw-like projection 32 for preventing the ring raceway 2 from rising on the upper edge of the lifting table 1. Have

  The lifting table 1 is connected to an upper base plate 75 of the rotation driving unit 6 described later, and moves up and down the ring track 2 including the inspection head. The ring track 2 has a split ring shape so that the ring track 2 can be inserted into the skirt opening 93 in the same manner as the lift table 1, and the groove 42 provided in the underline portion of the ring track 2 and the claw shape of the lift table 1. When the projection 32 is fitted, the lifting table 1 and the ring track 2 are integrated to prevent separation during driving, and the roller 43 provided on the lower surface of the track smoothly runs on the lifting table 1.

  A rack 44 is provided on the outer periphery of the ring track 2, and rotates on the lifting table 1 by meshing with a gear B 76 of the rotation drive unit 6 described later. On the ring raceway 2, a screw hole for attaching the inspection arm 3 for offsetting the inspection head 7 from the orbit position to the vicinity of the RIP weld 89 is provided.

  4 and 5, the inspection arm 3 is inserted into the narrow portion of the gap 90 of the double cylindrical portion, from the ring track 2 position to the vicinity of the RIP welded portion (nozzle weld line) 89. In order to make the inspection head 7 approach, the plate 21 having a length equal to or less than the height of the skirt opening 93 (see FIG. 11) is connected in multiple stages by a hinge 28 that can be locked by operating the lever 29. That is, the height of the inspection head 7 from the ring track 2 can be determined by connecting the plates 21 shown in FIG. The inspection head is installed on the plate 21.

  Further, the inspection head 7 includes an inspection head holder 22 and a gimbal mechanism 23 that supports horizontal / vertical rotation for stably pressing the probe 25, and further, as a means for transmitting sound waves of the probe In order to supply the contact medium (for example, water) to the inspection surface, a supply hose 27 and a contact medium supply outlet 26 are provided, and outer cylindrical portions 105 (see FIG. 11) are provided at the left and right ends of the inspection head holder 22. A ball plunger 24 for pressing against the inner surface is attached, and the probe 25 is pressed against the inspection surface. And the inspection head 7 attached to the plate 21 has a structure in which a plurality of inspection heads in the up-and-down direction can be expanded by connecting a plurality of inspection heads via hinges 8, and FIG. Is shown.

  Further, FIG. 5 shows the structure of a probe, a shoe, and a water supply port, which are constituent elements of the inspection head. As shown in the drawing, a water is placed in a space surrounded by the shoe, the probe 25, and the inspection surface. Water is supplied from the supply port, and this space is used as a watertight part (water pool part) to transmit vibrations by the vibrator.

  In turn, in FIG. 2, the elevating drive unit 5 is attached to the inspection apparatus mounting base 4 via the fixed plate 57. The elevating drive unit 5 includes an elevating drive motor 52, a gear 53, a nut 58, and a ball screw 54. By rotating the elevating drive motor 52, rotational power is transmitted to the gear 53 and the nut 58 is rotated. The ball screw 54 is moved up and down. As shown in the figure, an elevating drive unit for elevating the elevating table is installed outside the double pipe, and the elevating table and the ring track are moved up and down from the outside.

  A lower base plate 59 is attached to the upper end portion of the ball screw 54. The fixed plate 57 is provided with two elevating guide rails 51 for restraining the rotation of the lower base plate 59 that moves up and down and guiding the raising and lowering. With this configuration, the lower base plate 59 moves up and down along the lifting guide rail 51 by driving the lifting drive motor 52. The lift drive motor 52 is provided with an encoder 55 for detecting the rotation of the lift drive motor 52, and the lift guide rail 51 is provided with a limit switch (not shown) for preventing the lower base plate 59 from overrunning. .

  Further, the XY slide table 8 has a structure in which two slide rails 63 in the front-rear direction and two slide rails 64 in the left-right direction are sandwiched between the lower base plate 59 and the upper sprayer 75 in the cross direction. By making the lower plate 59 and the upper plate 75 freely slidable in the XY direction, it is possible to move freely between the upper and lower plates.

  With the above-described configuration, the upper base plate 75 connected to the rotation driving unit 6 follows the external force without being affected by the position of the elevating driving unit 5 (contacts the outer cylindrical unit 105 and the inner cylindrical unit 106). (In accordance with FIG. 6), even if the cylindrical axis of the RIP casing 88 and the axes of the lifting table 1 and the ring track 2 are misaligned as shown in FIG. The inspection head 7 can be moved up and down by rotating the Y slide table 8 while absorbing the axial misalignment. FIG. 6 is a view showing a lifting / lowering state of the lifting table following the outer periphery of the RIP casing (inner cylindrical portion) when the lifting table moves up the gap between the double tubes.

  As shown in FIG. 2, the rotation drive unit 6 includes a gear B76 that meshes with a rack 44 provided on the ring track 2 on a base plate 75 that is integrated by screw connection with the lifting table 1 and a gear that meshes with a gear B76. A 72 and a rotation drive motor 71 for rotating the gear A 72 are provided. The rotational drive motor 71 is provided with a rotational position detection encoder 73 to detect the rotational angle based on the motor rotational speed and at the same time to detect the rotational end of the ring track 2 via the gear C77 meshing with the gear A72. A detection mechanism 74 is provided.

  The lifting table 1 and the ring track 2 are moved horizontally along the RIP casing 88 together with the XY slide table 8 by the operation of the lifting drive motor 52, and the ring track 2 is moved by the operation of the rotation driving motor 71. The inspection head 7 is rotated along the nozzle welded portion 89 by the above-described operation.

  Next, the operation and function of the inspection apparatus according to the embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a diagram illustrating an inspection state of the RIP welded portion by the inspection apparatus according to the present embodiment. FIG. 8 is a diagram illustrating an inspection situation when the inspection head of the inspection apparatus according to the present embodiment is moved to the uppermost position, and FIG. 9 is a view when the inspection head of the inspection apparatus according to the present embodiment is moved to the lowermost position. It is a figure showing a test | inspection condition. FIG. 10 is a diagram showing the inspection status of one flaw detection method in which the inspection heads of the inspection apparatus according to the present embodiment are attached to face each other.

  In accordance with a command from a control device (not shown), the elevating drive unit 5 is operated, and the elevating table 1 and the ring track 2 are moved up and down. Similarly, the ring track 2 is rotated by the operation of the rotation drive unit 6. By such an operation, the inspection head 7 moves up and down and rotates together with the inspection arm 3. The raising / lowering range of the inspection head 7 depends on the opening height 100 of the skirt opening 93 because the raising / lowering driving unit 5 and the rotation driving unit 6 are installed outside the double tube gap 90. Therefore, the necessary inspection range can be covered by arranging a plurality of inspection heads 7 on the inspection arm 3. As shown in FIG. 7, a rotary drive unit that drives the ring track 2 is arranged in the opening, and the lower and upper limits of the rotary drive unit are defined by the distance between the lower end and the upper end of the opening (opening height 100). doing.

  FIG. 8 shows an arrangement configuration in the case where the nozzle welded portion 89 is inspected and the inspection head 7 is at the uppermost portion. When the required volume inspection range 110 is inspected for the nozzle welded portion 89, the inspection head (1) 115 and the inspection head (2) 116 are installed in the inspection arm 3 at positions as shown in FIG. As shown in the figure, when the lifting table 1 is on the upper end surface of the skirt opening 93 (see FIG. 7), the ultrasonic beam (1) 111 emitted from the inspection head (1) 115 reaches the upper end of the volume inspection range 110. To do. Thereafter, when the lifting table 1 is lowered by the operation of the lifting drive unit 5 to the state shown in FIG. 9, the ultrasonic beam (1) 111 does not pass through the entire volume inspection range 110 but does not pass through. Since the ultrasonic beam (2) 112 emitted from the inspection head (2) 116 passes, the necessary volume inspection range 110 can be covered.

  In addition, when two inspection heads 7 are attached to face each other as shown in FIG. 10 (the ultrasonic beams 111 and 112 from the two inspection heads are combined at the welding site to be inspected), one of ultrasonic inspection methods is used. It is possible to perform inspection as one of the TOFDs (Time Of Flight Diffraction).

It is a perspective view which shows the whole structure which has the test | inspection apparatus which concerns on embodiment of this invention, and the double pipe gap part of test object. It is a perspective view which shows the structure of the raising / lowering drive part, rotation drive part, and XY slide table in the test | inspection apparatus which concerns on this embodiment. It is a figure which shows the raising / lowering table, ring track | orbit, and those connection structure in the inspection apparatus which concerns on this embodiment. It is a figure which shows the whole structure of the test | inspection arm and test head provided in the ring track | orbit regarding this embodiment. It is a figure which shows the structure of the probe in the test | inspection head regarding this embodiment. It is a figure which shows the raising / lowering state of the raising / lowering table which follows the RIP casing (inner cylindrical part) outer periphery when the raising / lowering table regarding this embodiment raises a double pipe | tube gap | interval part. It is a figure showing the inspection condition of the RIP welding part by the inspection apparatus which concerns on this embodiment. It is a figure showing the test | inspection condition when the test | inspection head of the test | inspection apparatus which concerns on this embodiment moves to the uppermost part. It is a figure showing the test | inspection condition when the test | inspection head of the test | inspection apparatus which concerns on this embodiment moves to the lowest part. FIG. 10 is a diagram showing the inspection status of one flaw detection method in which the inspection heads of the inspection apparatus according to the present embodiment are attached to face each other. It is sectional drawing which shows the structure of the attachment part of the internal pump and lower endplate in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lifting table 2 Ring track 3 Inspection arm 4 Inspection apparatus mounting base 5 Lifting drive part 6 Rotation drive part 7 Inspection head 8 XY slide table 21 Plate 22 Inspection head holder 23 Gimbal 24 Ball plunger 25 Probe 26 Contact medium supply Exit 27 Hose 28 Hinge 29 Lever 31 Small roller 32 Claw-shaped projection 33 Conical roller 42 Groove 43 Roller 44 Rack 51 Lifting guide rail 52 Lifting drive motor 53 Gear 54 Ball screw 55 Encoder 57 Fixing plate 58 Nut 59 Lower base plate 63 Front-rear slide rail 64 Left-right slide rail 71 Motor for rotation drive 72 Gear A 73 Rotation position detection encoder 74 Rotation end detection mechanism 75 Upper base plate 76 Gear B 77 Gear C
86 Lower end plate 88 RIP casing 89 RIP welded portion 90 Double pipe gap portion 92 Internal pump nozzle 93 Skirt opening portion 94 Stabilizing portion 100 Opening height 105 Outer cylindrical portion 106 Inner cylindrical portion 110 Volume inspection range 111 Ultrasonic beam ( 1)
112 Ultrasonic beam (2) 115 Inspection head (1)
116 Inspection head (2)

Claims (7)

An inspection apparatus for inspecting a portion to be inspected of the inner cylindrical portion by moving the inspection head up and down in a double tube gap formed between the outer cylindrical portion and the inner cylindrical portion,
A lift drive unit installed on a fixed substrate, a base plate that moves up and down by driving the lift drive unit, a lift table that moves up and down in connection with the base plate, a rotation drive unit provided on the base plate, and the lift table A ring raceway that is rotatably held on the ring raceway, and an inspection head attached to the ring raceway via an inspection arm,
Ascending and descending the lifting table and the ring raceway in the double pipe gap by raising and lowering by the raising and lowering drive unit, and rotating the ring orbit by rotation of the rotation drive unit,
An inspection apparatus, wherein the inspection head is moved up and down along the gap between the double tubes. In claim 1,
An opening having a predetermined height is provided in the outer cylindrical portion,
The rotational drive unit that rotationally drives the ring track in the opening is disposed,
The lower limit and the upper limit of the raising / lowering of the said rotational drive part are prescribed | regulated by the distance between the lower end of the said opening part, and an upper end. Inspection apparatus characterized by the above-mentioned. In claim 1 or 2,
The base plate has an upper base plate and a lower base plate,
Interposing a slide table movable on a plane between the upper and lower base plates,
The inspection apparatus, wherein the elevating table and the ring orbit are made to follow the shape of the double gap portion by the mobility of the slide table. In claim 1, 2 or 3,
The inspection head includes a probe having a vibrator for generating a vibration wave, a shoe for disposing the probe opposite to the inner cylindrical portion, and a supply port for supplying a contact medium for propagating the vibration wave With
An inspection apparatus, wherein a space surrounded by the shoe, the probe, and the inner cylindrical portion is filled with the contact medium. In claim 1, 2, 3 or 4,
The inspection apparatus includes a pressing unit that presses the inner peripheral surface of the outer cylindrical portion, and the pressing head can always contact the outer peripheral surface of the inner cylindrical portion by the pressing unit. In claim 1, 2 or 3,
The inspection arm is a multi-stage connecting structure in which plates of a predetermined length are connected by a connecting means,
The inspection apparatus, wherein the inspection head is mounted on the plate. In claim 1, 2 or 3,
An inspection apparatus, wherein a plurality of the inspection heads are mounted in an ascending / descending direction of the inspection arm to expand an inspection range.

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