JP2502997Y2 - Pressure vessel stud bolt flaw detector - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention inserts a probe into an inspection hole formed in an axial center of a stud bolt arranged in a circumferential direction of a pressure vessel body flange. The present invention relates to a stud bolt flaw detector for a pressure vessel for inspecting a stud bolt.

[Prior Art] In a nuclear power plant, at the time of periodic inspection of a reactor pressure vessel, stud bolts arranged on a body flange of the reactor pressure vessel and used to fasten a lid of the pressure vessel are inspected.

An inspection hole for measuring the sealing surface pressure between the body flange and the lid when the stud bolt is fastened is formed in the shaft center of these stud bolts. At the time of regular inspection, this inspection hole was used to confirm the soundness of the stud bolt, and a probe was inserted into the inspection hole to perform a flaw inspection of the stud bolt.

[Problems to be Solved by the Invention] By the way, the probe used in the above-described inspection method uses a flaw detection device in which a probe is provided at the tip of a linear support rod. It will be inserted into the inspection hole of the bolt to detect flaws, but the inspection hole is deep (about 2 m)
Therefore, if the length of the support rod becomes long and the space above the stud bolt is narrow, the support rod cannot be operated, and the flaw inspection of the support rod is difficult.

The present invention was devised to solve the above problems, and an object thereof is to provide a stud bolt flaw detector for a pressure vessel that allows a probe to be easily inserted into an inspection hole of a stud bolt. It is in.

[Means for Solving the Problems] In order to achieve the above object, the present invention inserts a probe into an inspection hole formed in an axial center of a stud bolt arranged in a circumferential direction of a pressure vessel body flange. In the flaw detector for inspecting the stud bolt, a base fixed in the vicinity of the body flange and a telescope telescopically formed so as to be inserted into the inspection hole of the stud bolt from the base. Tube, a probe for flaw detection of a stud bolt provided at the tip of the telescope tube, a fluid supply means for supplying a pressure fluid into the tube to extend the telescope tube, and a tip portion of the telescope or the like Connected to
And a suspending wire for suspending and contracting the telescope tube.

[Operation] According to the above configuration, the telescope tube is the pressure fluid supplied from the fluid supply means, and after the probe at the tip thereof is inserted so as to reach the bottom of the inspection hole of the stud bolt,
By being gradually lifted by the hanging wire and contracted, it is possible to perform flaw detection inspection while sequentially raising the probe from the lower side to the upper side.

The telescope tube is contracted by the suspension wire before insertion into the inspection hole of the stud bolt or after withdrawal, so this flaw detector can be easily positioned even in a narrow space above the stud bolt. The probe for the stud bolt can be inspected by extending the probe from that position and inserting the probe at its tip into the inspection hole.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings.

1 to 3 show a stud bolt flaw detection test of a pressure vessel according to the present invention placed on a body flange with a lid of the reactor pressure vessel removed.

In the figure, reference numeral 1 denotes a body flange of a pressure vessel (not shown), and a large number of stud bolts 2 are arranged along the circumferential direction of the body flange 1. These stud bolts 2
As described above, the inspection hole 3 is formed in the axis center of.

Reference numeral 4 denotes a flaw detector for inserting the probe 5 into the inspection hole 3 of the stud bolt 2 to inspect the stud bolt 2. In the present embodiment, the flaw detector 4 has a base as shown in the drawing. 6 is provided on a moving base 7 formed to be movable on the body flange 1.

As shown in FIGS. 1 to 3, the moving table 7 is composed of an upper moving table 8 and a lower moving table 9, and a space between these upper and lower moving tables 8 and 9 in the longitudinal direction thereof. A moving means 10 for alternately moving the moving bases 8 and 9 is provided, and clamps 11 for holding the stud bolts 2 are provided at both ends of the moving bases 8 and 9, respectively.

As shown in the drawing, the base 6 is provided on the upper moving table 8 so as to be movable in the longitudinal direction thereof.
A guide groove 13 is formed along the longitudinal direction of the upper moving table 8 along the arrangement of the stud bolts 2 so as to be guided by a guide rail 12 formed in an arc shape. Guide rail
A guide rack 14 is provided along the guide 12 on the base 12, and a pinion 15 that meshes with the guide rack 14 is rotatably provided on the base 6 via a drive motor 16.

As shown in FIG. 3, a vertical frame 17 is provided on the base 6.
Are erected in parallel with each other along the stud bolt 2 so as to extend higher than the stud bolt 2 and stand upright. At the upper end of the vertical frame 17, a horizontal frame extending horizontally above the stud bolt 2 is provided. 18 are provided. This horizontal frame
A support frame 20 is rotatably provided on the lower surface of 18 to support the telescope tube 19 so as to hang downward and reach the upper portion of the stud bolt 2. The support frame 20 is rotationally driven. A rotation driving motor 21 for driving is provided on the horizontal frame 18. This support frame 20
A support tube body 22 is provided below the lower part of the support tube 22 for guiding the telescope tube 19 to extend and contract vertically and accommodating the contracted telescope tube 19.

As shown in FIG. 4, the telescope tube 19 includes a first tube 23 fixed in a support cylinder 22 and a second tube 23 which is inserted from the inside of the first tube 23 so as to extend and contract downward. A pipe 24 and a third pipe 25 which is inserted from the inside of the second pipe 24 downwardly and elastically.
The third pipe 25 is elastically fitted into the third pipe 25 and is composed of a fourth pipe 26 having a probe 5 at the tip thereof. The lower ends of the first to third pipes 23, 24, 25 are respectively formed. A step portion 27 projecting inward is formed in the portion, and the second to fourth pipes 24, 25,
A stopper for contacting the step portion 27 and restricting the extension of the pipes 24, 25, 26 is provided on the outer periphery of the upper end portion of each of the 26.
28 is provided, and the fourth pipe 26 has a fourth
A stopper 29 for restricting the contraction of the tube 26 is provided. A seal member 30 is provided on the inner peripheral surface of the step portion 27.

A fluid supply means 31 for supplying a pressure fluid into the tube 19 is provided on the upper part of the telescope tube 19, and the fluid supply means 31 has a supply tube whose one end side is connected to a supply source (not shown). 32 are connected. Telescope tube 19
Is a second pipe 24 from the first pipe 23, a third pipe 25 from the second pipe 24, and a third pipe 25 from the third pipe 25 by the pressure fluid supplied from the fluid supply means 31 into the pipe 19. The fourth pipe 26 is sequentially extended, and the supplied pressure fluid is prevented from leaking from the inside of the pipe to the sealing member 30 of the step portion 27.
Has been cut off by.

As shown in FIG. 4, a cylindrical probe support portion 33 that supports the probe 5 is provided at the tip end portion of the fourth pipe 26. The probe support portion 33 has a cylindrical shape. The plurality of probes 5 are attached to the outer peripheral surface of the probe 5 via spring members 34. When these probes 5 are inserted into the inspection holes 3 of the stud bolts 2, the spring members 34 make soft contact with the peripheral surface of the inspection holes 3, and the probes 5 respectively. The transmission directions of are transmitted in different directions as indicated by arrows in the figure. Above probe support
A contact sensor 35 for detecting contact with the bottom of the inspection hole 3 of the stud bolt 2 is provided at the lower end of the 33, and the telescope tube 19 is contracted at the upper end of the probe support 33. A suspending wire 36 for connecting is connected.

As shown in FIG. 4, the suspension wire 36 has a support frame.
The guide roller is fed from the winding device 37 provided on the 20.
After passing through the telescope tube 19 via 38, the probe support 33
Is connected to the upper end of. The guide rollers 38 are provided on both sides of the hanging wire 36 so as to regulate the horizontal movement of the hanging wire 36.
As shown in FIG. 5, a detection roller 39 for detecting the unwinding amount of the hanging wire 36 is provided below, and the detection roller 39 has an encoder 40 for detecting the rotation amount thereof. It is connected.

The winding device 37, as shown in FIG.
A wire drum 41 that winds around 36 is detachably connected to a drive motor 43 via a clutch 42. The clutch 42 is connected to a cam member 45 connected to a clutch cylinder 44 as shown in the drawing. The cam member 45 engages and disengages the clutch 42 by the expansion and contraction of the cylinder 44, and the wire drum shaft.
The connection between 41a and the drive motor shaft 43a is disengaged.

As shown in FIG. 3, the support frame 20 is provided with a probe 5 at the tip of the telescope tube 19 and a cable drum 47 for winding and feeding a cable 46 for transmitting and receiving a signal. . This cable drum 47 is
As shown in the figure, there is provided a conston spring 48 that constantly urges the drum 47 in the direction in which the cable 46 is wound.
The reel 49 is urged in the winding direction to be wound around a reel 49 arranged in parallel with each other, and the other end side is wound around a reel 50 provided coaxially with the cable drum 47. This Conston Spring 48
When the telescope tube 19 is contracted, the drum 47 is rotated and the cable 46 is wound around the reel 50 via the reel 50 following the contraction.

 Next, the operation of the above embodiment will be described.

First, in FIG. 1, the flaw detector 4 is placed along the arrangement of the stud bolts 2 on the body flange 1 by a crane or the like not shown, and the clamp 11 holds the stud bolts 2 to fix the movable table 7. . After the base 6 is moved on the movable table 7 and positioned on the stud bolt 2 to be inspected,
Pressure fluid is supplied from the fluid supply means 31 into the telescope tube 19 to extend the telescope tube 19, and the tip of the telescope tube 19 is inserted into the inspection hole 3 of the stud bolt 2, and the probe 5
Is landed on the bottom of the inspection hole 3.

After the probe 5 lands on the bottom of the inspection hole 3, the hanging wire
36 is wound up by the winding device 37 and the probe 5 is gradually raised to detect flaws. Next, the rotation drive motor 21 is used to support the support frame 20.
At the same time, the probe 5 is rotated by a predetermined angle to change the angle in the circumferential direction, and then the probe 5 is moved in the axial direction of the inspection hole 3 in the same manner as described above to perform a flaw inspection of the stud bolt 2.
When the probe 5 is raised, the cable 46 connected to the probe 5 is automatically wound around the cable drum 47 which is rotated by the biasing force of the Conston spring 48, and the suspension wire 36 is
Since horizontal movement is restricted by the guide roller 38, the guide roller 38 does not come off the wire drum 41 or twist.

Next, when performing a flaw detection inspection of another stud bolt 2, it is sufficient to move the base 6 along the guide rails 12 of the moving table 7. When moving the moving table 7, the upper and lower moving tables are moved. 8 and 9 may be moved alternately along the arrangement of the stud bolts 2.

Since the telescope tube 19 is contracted by the suspension wire 36 before the stud bolt 2 is inserted into the inspection hole 3 or after it is pulled out, the flaw detection device 4 can be easily installed even in a narrow space above the stud bolt 2. The stud bolt 2 can be positioned, and the probe 5 can be extended from that position and inserted into the inspection hole 3 to perform flaw detection inspection of the stud bolt 2.

In the flaw detector 4 of this embodiment, the lid of the pressure vessel (not shown) is removed in the reactor well (not shown) filled with water, and the stud bolt 2 is remotely operated. Since flaw inspection can be performed, inspection work can be performed safely without being exposed to radiation.

In the above-described embodiment, an example of the flaw detection device 4 which is capable of performing the flaw detection inspection of the stud bolt 2 from the trunk flange 1 with the lid removed is provided by movably providing the base 6 on the movable base 7. However, if the moving base 7 is not provided and a means for fixing the base 6 to the vicinity of the stud bolt 2 is provided, the flaw inspection of the stud bolt 2 can be performed without removing the lid of the pressure vessel.

[Advantage of the Invention] According to the present invention, since the probe is provided at the distal end of the telescopic tube which can be expanded and contracted, it can be easily positioned even in a narrow space above the stud bolt and its position. The probe can be inserted into the inspection hole by extending it from the above position, and the flaw inspection of the stud bolt can be performed from the hole.

[Brief description of drawings]

1 is a schematic plan view showing an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a partially cutaway sectional view taken along line III-III of FIG. 1, and FIG. 4 is a telescope. FIG. 5 is a cross-sectional view showing details of the pipe, FIG. 5 is a view showing details of the hanging wire winding device, and FIG. 6 is a perspective view showing details of the cable drum. In the figure, 1 is a body flange, 2 is a stud bolt, 3 is an inspection hole, 4 is a flaw detector, 5 is a probe, 6 is a base, 19 is a telescope tube, 31 is a fluid supply means, and 36 is a hanging wire. Is.

Front page continuation (72) Inventor Mitsuru Tamura 1 Shinshinarahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima Harima Heavy Industries Ltd. Yokohama No. 1 factory (72) Koji Kobayashi 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa Ishikawajima Harima Heavy Industries Co., Ltd. Yokohama First Factory (56) References JP-A-60-38641 (JP, A)

Claims (1)

(57) [Scope of utility model registration request] 1. A flaw detection device for inspecting a stud bolt by inserting a probe into an inspection hole formed in an axial center of a stud bolt arranged in a circumferential direction of a pressure vessel barrel flange, wherein A base fixed in the vicinity, a telescope tube formed telescopically so as to be inserted into the inspection hole of the stud bolt from the base, and a stud bolt provided at the tip of the telescope tube. A probe for flaw detection, a fluid supply means for supplying a pressure fluid into the telescope tube in order to extend the telescope tube, and a tip end portion of the telescope tube, for lifting and contracting the telescope tube. A stud bolt flaw detector for a pressure vessel, comprising a hanging wire.