JPH095306A - Flow detector for nozzle - Google Patents

Abstract

PURPOSE: To provide a flow detector for nozzle for which no track is required and, therefore, no track removing work is required and can efficiently detect flaws from a nozzle. CONSTITUTION: A flaw detector for nozzle is provided with a member 17 which is faced to the large-diameter section 3 of a nozzle 2, has a suction port 21 for large-diameter section which can be switched between a sucking state and a non-sucking state, and is mounted on the large-diameter section 3 of the nozzle 2, a member 18 which is faced to the tapered section 5 of the nozzle 2 between the large- and small-diameter sections 3 and 4 of the nozzle 2, has a suction port 26 for tapered section which can be switched between a sucking state and a non-sucking state, and is mounted on the tapered section 5 while the member 17 is engaged with the member 17 so that the members 17 and 18 can be moved relatively to each other in the peripheral direction of the nozzle 2, and an ultrasonic flaw detecting probe 15 supported by the member 17 through an arm mechanism 12. The members 17 and 18 are alternately moved in the peripheral direction of the nozzle 2 by switching the ports 21 and 26 to sucking states and non-sucking states.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle flaw detector for ultrasonically flaw detection of a welded portion of a nozzle portion of a reactor pressure vessel or the like.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 11, a nozzle 2 protruding from a side surface of a pressure vessel 1 in a nuclear reactor or the like is
It has a large diameter portion 3, a small diameter portion 4, and a taper portion 5 provided between the large diameter portion 3 and the small diameter portion 4, and the welding portion of the pressure vessel 1 centered on the nozzle 2 is The nozzle flaw detection device for ultrasonic flaw detection includes an annular track 6 that can be divided into two and is mounted around the small diameter portion 4 of the nozzle 2, and a traveling carriage 7 mounted on the track 6.

A rack 8 is provided on the outer periphery of the track 6, and the traveling carriage 7 is engaged with the pinion 9 which is rotationally driven while meshing with the rack 8 and which is engaged with the side surface of the track 6 to roll. A guide wheel 10 is provided.

A flaw detection section body 11 is attached to the traveling carriage 7, and a base end of an arm mechanism 12 is pivotally attached to the flaw detection section body 11, and by extending the cylinder device 13, the arm mechanism 12 is extended. The positioning roller 14 attached to the tip of the pressure vessel 1 can be brought into contact with the surface of the pressure vessel 1, is movable along the arm mechanism 12, and outputs a flaw detection signal to a monitor (not shown). A probe 15 for ultrasonic flaw detection test is attached to the arm mechanism 12.

When performing ultrasonic flaw detection on the welded portion of the pressure vessel 1 centered on the nozzle 2 by the conventional nozzle flaw detector shown in FIG. 11, the track 6 is divided into two around the small diameter portion 4 of the nozzle 2. Attach the traveling carriage 7 to the track 6
Attach to

After the traveling carriage 7 is mounted on the track 6, the cylinder device 13 is extended and the positioning roller 14 is attached to the pressure vessel 1.
The probe 15 is brought into contact with the surface of the pressure vessel 1 and the arm mechanism 12 is held substantially parallel to the surface of the pressure vessel 1.
While moving from the base end of 2 toward the tip of the arm mechanism 12, the welded portion is detected.

When the probe 15 reaches the tip of the arm mechanism 12, the movement of the probe 15 is stopped, the pinion 9 is rotationally driven by a predetermined amount, and the central axis of the nozzle 2 is used as the center of rotation.
The arm mechanism 12 is rotated together with the traveling carriage 7 by a predetermined angle.

Next, flaw detection is performed while moving the probe 15 from the tip of the arm mechanism 12 toward the base end of the arm mechanism 12.

When the probe 15 reaches the base end of the arm mechanism 12, the movement of the probe 15 is stopped and the pinion 9 is again driven by a predetermined amount to rotate the arm mechanism 12 by a predetermined angle. By moving the probe 15 from the base end of the arm mechanism 12 toward the tip of the arm mechanism 12 for flaw detection, the probe 15 is moved to the position shown in FIG.
It is possible to trace the probe locus 16 as described above and perform ultrasonic flaw detection on the welded portion with the nozzle 2 as the center.

When the ultrasonic flaw detection is completed, the traveling carriage 7 is removed from the track 6, and the bisected track 6 is removed from around the small diameter portion 4 of the nozzle 2.

[0011]

In the conventional nozzle flaw detector described above, when ultrasonically flaw-detecting the welded portion, the divided track 6 is attached around the small-diameter portion 4 of the nozzle 2 and joined in an annular shape. After the ultrasonic flaw detection is completed, it is necessary to divide the track 6 into two again and remove it from the periphery of the small diameter portion 4, so it takes time and effort to attach and remove the track 6.
It had the drawback of poor workability.

In view of the above situation, it is an object of the present invention to provide a nozzle flaw detection device which does not require the use of a raceway, can eliminate the work of attaching and detaching the raceway, and can efficiently perform the flaw detection work of the nozzle portion. It is what

[0013]

According to the present invention, a large-diameter portion attachment member facing a large-diameter portion of a nozzle and having a large-diameter suction port capable of switching between a suction state and a non-suction state, and a nozzle for the large-diameter portion are provided. Facing the taper portion between the large diameter portion and the small diameter portion, it has a taper portion suction port that can switch between a suction state and a non-suction state, and is relatively movable in the nozzle circumferential direction with respect to the large diameter portion attachment member. Nozzle flaw detection device, comprising: a taper portion attachment member that engages with each other to provide a probe for an ultrasonic flaw detection test supported by the large diameter portion attachment member through an arm mechanism. It depends on.

[0014]

The large-diameter portion suction port of the large-diameter portion attachment member faces the large-diameter portion of the nozzle, and the taper portion suction port of the tapered-portion attachment member is tapered between the large-diameter portion and the small-diameter portion of the nozzle. And the large-diameter portion suction port is in a non-suction state and the taper portion suction port is in a suction state, and the taper portion attachment member is fixed to the taper portion of the nozzle,
After moving the large-diameter part attachment member relative to the taper part attachment member in the circumferential direction of the nozzle, fix the large-diameter part attachment member to the large-diameter part of the nozzle by setting the large-diameter part suction port to the suction state. When the operation of relatively moving the taper portion attachment member in the nozzle circumferential direction with respect to the large diameter portion attachment member with the portion suction port in a non-suction state is repeated, the ultra large portion attached member is supported by the arm mechanism. The probe for the ultrasonic flaw detection test has a shape that moves in the circumferential direction of the nozzle without a trajectory, and flaw detection around the nozzle can be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show an embodiment of the present invention,
In the figure, the parts denoted by the same reference numerals as those in FIG. 11 represent the same things, and a large diameter part attachment member 17 is arranged on the outer periphery of the large diameter part 3 of the nozzle 2, and the tapered part 5 of the nozzle 2 is A taper portion attachment member 18 is arranged on the outer periphery, and the flaw detection portion main body 11 is attached to the large diameter portion attachment member 17 via a pedestal 19.
Is attached.

Similar to the conventional example shown in FIG. 11, an arm mechanism 12 is pivotally attached to the flaw detection unit main body 11, and a positioning roller attached to the tip of the arm mechanism 12 by extending the cylinder device 13. The arm mechanism 12 can be held substantially parallel to the surface of the pressure vessel 1 by bringing 14 into contact with the surface of the pressure vessel 1. The monitor is movable along the arm mechanism 12 and is not shown. A probe 15 for ultrasonic flaw detection test that outputs a flaw detection signal is attached to the arm mechanism 12.

As shown in FIG. 3, the large diameter portion attachment member 17 and the taper portion attachment member 18 have a large diameter portion 3 of the nozzle 2.
In addition, the large-diameter portion attachment member 17 is formed in a fan shape extending along the outer periphery of the tapered portion 5, and has a plurality of large-diameter portions facing the large-diameter portion 3 of the nozzle 2, as shown in FIGS. 2 and 5. Partial suction port 21 is provided.

A suction cup 22 made of an elastic material is attached to the tip of the large diameter suction port 21, and the tip of the suction cup 22 contacts the large diameter section 3 of the nozzle 2 as shown in FIG. ing. Further, the suction pipe 2 is provided on the base end side of the large-diameter portion suction port 21.
3, the suction pipe 23 is connected to an external suction device via a flexible pipe (not shown), and can be switched between a suction state and a non-suction state.

As shown in FIG. 2, the large-diameter portion attachment member 17 has a T-shaped cross section at a portion near the position where the pedestal 19 is attached and has a curvature concentric with the nozzle 2 (see FIG. 3).
The engaging portion 24, which is shown in FIG.
8 is provided so as to project in parallel with the taper portion attachment member 18, and a rack 25 having a curvature concentric with the nozzle 2 is provided below the engagement portion 24. It is provided so as to be parallel to the attachment member 18 (see FIG. 4).

Further, as shown in FIGS. 2, 3 and 5, the taper part attachment member 18 is provided with a plurality of taper part suction ports 26 facing the taper part 5 of the nozzle 2, and the taper part suction ports. A suction cup 27 made of an elastic material is attached to the tip of 26, and the tip of the suction cup 27 contacts the tapered portion 5 of the nozzle 2 as shown in FIG. Further, the proximal end side of the taper portion suction port 26 is connected to a suction pipe 28, which is connected to an external suction device via a flexible pipe (not shown), and is in a suction state and a non-suction state. You can switch to and.

The taper portion attachment member 18 is shaped so as to embrace the upper side and the lower side of the engagement portion 24 of the T-shaped cross section which is provided to project from the large diameter portion attachment member 17. A pair of engagement portions 29 are provided so as to project so that the large diameter portion attachment member 17 and the taper portion attachment member 18 are not separated from each other, and the roller bearing 30 is provided between the engagement portions 24 and 29. Is provided, and a plurality of rollers 31 rotatably supported on the taper portion attachment member 18 by a shaft extending in the radial direction of the nozzle 2 are in contact with the T-shaped top surface of the engaging portion 24. There is.

The taper portion attachment member 18 has a structure shown in FIGS.
As shown in FIG. 3, a drive gear 32 that meshes with the rack 25 is provided, and this drive gear 32 meshes with a pinion 34 that is rotated by a motor 33 that can rotate normally and reversely, and the motor 33 rotates the pinion 34. As a result, the drive gear 32 meshed with the rack 25
Is driven to rotate, the large-diameter portion attachment member 17 and the taper portion attachment member 18 are smoothly guided by the roller bearing 30 and the roller 31 while maintaining the parallel state by the engagement portions 24 and 29, and the nozzle 2 It is designed to be able to move in the circumferential direction.

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

When performing ultrasonic flaw detection on the welded portion of the pressure vessel 1 centering on the nozzle 2, the large diameter portion suction port 21 of the large diameter portion attachment member 17 is connected to the large diameter portion of the nozzle 2 as shown in FIG. The taper part attachment member 1 is arranged so as to face the part 3.
8 is aligned with the large-diameter portion attachment member 17 in the circumferential direction of the nozzle 2 and the taper portion suction port 26 of the taper portion attachment member 18 is arranged to face the taper portion 5 of the nozzle 2.

When the suction pipes 23, 28 shown in FIG. 2 are brought into a suction state, the large-diameter portion suction port 21 causes the large-diameter portion 3 of the nozzle 2 to move.
Is attached to the large-diameter portion attachment member 17 and is fixed to the large-diameter portion 3,
The taper portion suction port 26 is sucked onto the taper portion 5 of the nozzle 2, and the taper portion attachment member 18 is fixed to the taper portion 5.

At this time, as shown in FIGS. 6 and 7, the large-diameter portion attachment member 17 and the taper portion attachment member 18 are fixed to the nozzle 2 in a state where the phases of the nozzle 2 in the circumferential direction match. Will be.

In this state, the cylinder device 13 shown in FIG. 1 is extended to bring the positioning roller 14 into contact with the surface of the pressure vessel 1, and the arm mechanism 12 is held substantially parallel to the surface of the pressure vessel 1 to detect the probe. While moving 15 from the base end of the arm mechanism 12 toward the tip end of the arm mechanism 12, the welding point is inspected.

Next, when the suction pipe 23 of FIG. 2 is switched to the non-suction state while the suction pipe 28 is kept in the suction state, the taper portion suction port 26 is attached to the taper portion 5 of the nozzle 2 and the taper portion is attached. The member 18 remains fixed to the taper portion 5, but the large-diameter portion suction port 21 stops sucking the large-diameter portion 3 of the nozzle 2. It becomes movable with respect to the diameter portion 3.

When the motor 33 is rotated forward by a predetermined amount in this state, the drive gear 32 is rotated forward through the pinion 34, and the taper portion attachment member 18 fixed to the taper portion 5 is provided.
Is used as a reaction force, and the large-diameter portion attachment member 1 is inserted through the rack 25.
As shown in FIGS. 8 and 9, the reference numeral 7 rotates about the central axis of the nozzle 2 as the center of rotation and rotates clockwise by a predetermined angle when viewed from the front of the nozzle 2.

Next, the suction pipe 23 of FIG. 2 is switched to the suction state, the large diameter portion suction port 21 is sucked to the large diameter portion 3 to fix the large diameter portion attachment member 17 to the large diameter portion 3, and the suction pipe 28 is switched to a non-suction state, suction of the taper portion suction port 26 to the taper portion 5 is stopped, and the taper portion attachment member 18 is made movable with respect to the taper portion 5.

In this state, when the motor 33 is reversely rotated by a predetermined amount, the drive gear 32 is reversely rotated through the pinion 34, so that the rack 25 of the large diameter portion attachment member 17 fixed to the large diameter portion 3 is moved. As a reaction force receiver, the taper portion attachment member 18 has a center axis of the nozzle 2 as a rotation center as shown in FIG.
When viewed from the front of the nozzle 2, the large-diameter part attachment member 17 and the nozzle 2 which are rotated by a predetermined angle in the clockwise direction and are rotated by a predetermined angle first.
Therefore, the phases in the circumferential direction of are the same.

In this state, when the suction tube 28 is switched to the suction state while the suction tube 23 of FIG. 2 is kept in the suction state, the large diameter portion attachment member 17 and the taper portion attachment member 18 are subjected to flaw detection as described above. The welding part is fixed to the nozzle 2 at a position rotated by a predetermined angle in the clockwise direction when viewed from the front of the nozzle 2, and in this state, the probe 15 shown in FIG. The flaw detection is performed while moving the tip 12 toward the base end.

Next, the suction tube 28 of FIG. 2 is switched to the non-suction state while the suction tube 28 is kept in the suction state, and the taper portion attachment member 18 is used as a reaction force to move the large diameter portion attachment member 17 to a predetermined angle. After the rotation, the suction pipe 23 is switched to the suction state and the suction pipe 28 is switched to the non-suction state, respectively, and the rack 25 of the large diameter portion mounting member 17 is used as a reaction force to receive the taper portion mounting member 18 in the large diameter portion. The attachment member 17 and the nozzle 2 are rotated so that their phases in the circumferential direction coincide with each other, and the suction pipe 28 is switched to the suction state while the suction pipe 23 is kept in the suction state, so that the large diameter portion attachment member 17 and the tapered portion are attached. By fixing the mounting member 18 to the nozzle 2 and moving the probe 15 from the base end to the tip of the arm mechanism 12, it is possible to detect a welded portion at a position further rotated by a predetermined angle. .

By repeating the above-described operation, the probe 15 can trace the probe locus 16 as shown in FIG. 12 and ultrasonically detect the welded portion around the nozzle 2 as in the conventional case. .

Upon completion of ultrasonic flaw detection, the suction tubes 23, 2
8 may be switched to a non-suction state, and the large diameter part attachment member 17 and the taper part attachment member 18 may be separated from the nozzle 2.

In this way, it is not necessary to use a track, the work of attaching and removing the track can be unnecessary, and the flaw detection work of the nozzle 2 portion can be performed efficiently.

The nozzle flaw detector of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0039]

As described above, according to the nozzle flaw detector of the present invention, it is not necessary to use a conventional track, and it is possible to eliminate the time-consuming and troublesome work of attaching and detaching the track. It is possible to obtain an excellent effect that the flaw detection work of the portion can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a side view showing a part of an embodiment of a nozzle flaw detector according to the present invention by cutting.

FIG. 2 is a vertical sectional side view showing an enlarged main part of the present invention.

FIG. 3 is a front view of a part of FIG. 2 seen from a III-III direction.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a bottom view of FIG. 2 viewed from the V direction.

FIG. 6 is a front view showing an operating state of an embodiment of the nozzle flaw detection device of the present invention.

FIG. 7 is a view on arrow VII-VII in FIG.

FIG. 8 is a front view showing the next operation state of FIG. 6;

FIG. 9 is a view as viewed in the direction of arrows IX-IX in FIG. 8;

10 is a front view showing the next operating state of FIG. 8. FIG.

FIG. 11 is a side view showing an example of a conventional nozzle flaw detector.

FIG. 12 is a front view showing the trajectory of the probe.

[Explanation of symbols]

 2 Nozzle 3 Large Diameter Part 4 Small Diameter Part 5 Tapered Part 12 Arm Mechanism 15 Probe 17 Large Diameter Part Attachment Member 18 Tapered Part Attachment Member 21 Large Diameter Part Adsorption Port 26 Tapered Part Adsorption Port

Claims (1)

[Claims] 1. A large diameter part attachment member facing a large diameter part of a nozzle and having a large diameter part suction port capable of switching between a suction state and a non-suction state; and a large diameter part and a small diameter part of the nozzle. A taper portion that faces the taper portion between them, has a taper portion suction port that can switch between a suction state and a non-suction state, and engages with the large diameter portion attachment member so as to be relatively movable in the nozzle circumferential direction. A nozzle flaw detection device comprising: an attachment member; and a probe for ultrasonic flaw detection test, which is supported by the large diameter portion attachment member via an arm mechanism.