JPH1062393A - Inspecting device of circumferential weld part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable inspection result by mounting a device body on a tubular member forming a circumferential seal weld part to be inspected, and scanning and inspecting the circumferential weld part by an inspecting probe. SOLUTION: Two probe raising and lowering mechanisms 70 are arranged on a rotating frame 61 with a circumferential space, and probes 80 are mounted on the lower. ends thereof. The probe raising and lowering mechanism 70 can move a probe support shaft 77 vertically by regulating the feed and discharge air quantity. The probe 80 has a tensile spring 87, so that a sensor 81 is pressed, in inspection, to a canopy seal part 11 having a dome-like section to hold a proper position. A body 30 is arranged around the canopy seal part 11 to be inspected, and fixed by a clamp mechanism 40, whereby the canopy seal part 11 can be inspected. Since the sensor 81 is pressed onto the canopy seal part 11 and moved along it when the height of the sensor 81 is regulated by the probe raising and lowering mechanism 70, and the rotating frame 61 is circumferentially driven by a rotating mechanism, flaw detection data can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-destructive inspection device for a welded portion, and more particularly to a non-destructive inspection device for a circumferential weld portion connecting pipes or tubular members or a circumferential seal weld portion surrounding the join portion. About.

[0002]

2. Description of the Related Art A circumferential weld, particularly a seal weld, of a tubular member leaks when cracks, cracks, or the like occur, and therefore it is desirable to inspect it periodically or as necessary. For example, FIG. 6 shows an upper structure of a pressurized water reactor, and a number of control rod driving devices 5 are erected on an upper lid 3 of the reactor vessel 1. The control rod driving device 5 uses an electromagnetic drive type latch to move the control rod driving shaft in the axial direction, that is, in the vertical direction, to insert the control rod into the core in the reactor vessel 1 or to pull out the control rod from the core. However, since the inside communicates with the high-pressure coolant space in the reactor vessel 1, FIG.
As shown in FIG. 8, a seal welding portion, that is, a canopy seal portion 11 is formed between the drive shaft housing 7 and the latch housing 9. The canopy seal portion 11 may crack due to fatigue or the like during long-term use, and it is expected that boric acid water as a reactor coolant leaks out. For this reason, conventionally, a visual inspection has been performed by periodically removing peripheral mounting parts to check for cracks or the like.

[0003]

Since a large number of control rod driving devices 5 are arranged in rows and columns in a plane, there is a portion where the visibility is obstructed by the above-described visual inspection. There was a problem that sufficient inspection was not carried out. Furthermore, there are dozens of control rod drive units 5 per reactor, and if inspectors visually inspect these one by one,
There is a problem that it takes a long time. Therefore, an object of the present invention is to provide a method for inspecting a circumferential weld such as a canopy seal that can be mechanically inspected without relying on the visual inspection of an inspector, and that provides a highly reliable inspection result. It is to provide a device.

[0004]

According to the present invention, an inspection apparatus for inspecting a circumferential weld between tubular members surrounds the tubular member proximate to the circumferential weld. An arc-shaped main body, clamp mechanisms respectively attached to both ends of the main body in a circumferential direction, a turning frame provided inside the main body so as to be movable in a circumferential direction, a probe elevating mechanism provided on the turning frame, the main body And a probe which is mounted on the probe and is exchangeably mounted on the probe elevating mechanism.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2, a canopy seal portion 11 to be inspected for flaw detection is formed between a drive shaft housing 7 surrounding a drive shaft of a control rod drive and a latch housing 9 screwed into the drive shaft housing. ,
These are indicated by two-dot chain lines to distinguish them from the inspection device 20. The main body 30 surrounding the drive shaft housing 7 and the latch housing 9 has a rigid arc frame 31, detection sensors 33a, 33b, 33c arranged along the upper edge thereof, and forms a framework of the inspection device 20. ing. Arc frame 31
A clamp mechanism 40 is provided at both ends of the arc frame body 3 on the outer peripheral surface of the latch housing 9 using an air cylinder or the like.
1 is held. Further, a turning mechanism 50 is provided at an intermediate portion of the main body frame 30 in the circumferential direction. The turning mechanism 50 has a turning motor 53 having an output shaft provided with a pinion gear 51 that meshes with a rack of a turning frame described later, a pinion gear 55 that meshes with a similar rack, and an encoder 59 having a pinion gear 57 that meshes with the same. ing. The turning motor 53 of the turning mechanism 50 drives the above-described rack, and the amount of turning of the rack is controlled by the pinion gears 55 and 57.
Is detected by the encoder 59 via the.

FIG. 3 shows the details of the mounting state of the swing motor 53 described above. The bracket 52 of the turning motor 53 is fixed to the outer peripheral surface of the arc frame 31. On the inner surface of the arc frame 31, an arc-shaped installation table 35 and a guide ring 37 are fixed, and the turning frame is interposed therebetween. 61 is provided movably. A flexible rack 63 is fixed to the outer peripheral surface of the revolving frame 61, and the pinion gear 51 is meshed with the flexible rack 63 as shown in the figure, and the pinion gear 55 is meshed with the flexible rack in a similar manner. In this way, when the turning motor 53 is operated, the flexible rack via the pinion gear 51,
As a result, the turning frame 61 is driven in the circumferential direction within a predetermined range.

Referring to FIGS. 1 and 2 again, two probe lifting / lowering mechanisms 70 are arranged on the revolving frame 61 at intervals in the circumferential direction, and the probe 80 is attached to the lower end thereof. FIG. 5 shows the overall mounting relationship between the probe elevating mechanism 70 and the probe 80, and FIG.
Respectively. In FIG. 5, a probe elevating mechanism 70 includes a cylinder 71, a hollow piston 73, a cylinder cover 75, a probe support shaft 77 inserted through the hollow piston 73, a compression spring 79 for biasing the probe support shaft 77 downward, and air amount adjustment. A hollow piston 73, that is, a probe support shaft 77 is provided by adjusting a supply and exhaust air amount.
Can be moved up and down. Further, the probe 80 has a sensor 81 such as an ultrasonic flaw detection sensor or an eddy current flaw detection sensor, support blocks 83 and 85 on which the sensor 81 is mounted, and a tension spring 87 for attracting the support blocks 83 and 85 to each other. Sensor 81 during inspection
However, the cross section is pressed against the dome-shaped canopy seal portion 11 to maintain a suitable position.

Since the inspection device 20 according to the present invention has the above-described structure, the inspection can be performed by disposing the main body 30 around the canopy seal portion 11 to be inspected and fixing the main body 30 with the clamp mechanism 40. Become. Then, after the height of the probe 80, that is, the sensor 81 is adjusted by the probe elevating mechanism 70, the swivel mechanism 50 is operated to set the probe elevating mechanism 7
The turning frame 61 supporting the probe 0 and the probe 80 is driven in the circumferential direction. In this manner, the sensor 81 of the probe 80 is pressed against the canopy seal portion 11 and moves along the same, so that flaw detection data can be obtained.
Then, when the detection sensors 33a, 33b, 33c of the main body 30 detect that the probe lifting mechanism 70 has reached the stroke end position indicated by the two-dot chain line in FIG.

[0009]

As described above, according to the present invention, an inspection apparatus having a relatively compact main body is attached to a tubular member forming a circumferential seal weld, and the circumferential weld is used for an inspection probe. In this case, highly reliable measurement data can be obtained for the entire area.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an inspection device according to an embodiment of the present invention.

FIG. 2 is an overall plan view of the inspection device corresponding to FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a side sectional view of the embodiment.

FIG. 5 is a sectional view taken along line VV in FIG. 2;

FIG. 6 is a vertical sectional view showing an example of a reactor control rod driving device inspected by the apparatus of the present invention.

FIG. 7 is a partially enlarged perspective view of FIG. 6;

FIG. 8 is a partially enlarged sectional view of FIG. 7;

[Explanation of symbols]

 7 Drive shaft housing 9 Latch housing 11 Canopy seal part 20 Inspection device 30 Main body 31 Arc frame 33a, 33b, 33c Detection sensor 35 Installation base 37 Guide ring 40 Clamp mechanism 50 Rotating mechanism 51 Pinion gear 53 Rotating motor 55, 57 Pinion gear 59 Encoder 61 Revolving frame 63 Flexible rack 70 Probe elevating mechanism 71 Cylinder 73 Hollow piston 75 Cylinder cover 77 Probe support shaft 79 Compression spring 80 Probe 81 Sensor 83, 85 Support block 87 Tension spring

Claims (1)

[Claims] 1. An inspection device for inspecting a circumferential weld between tubular members, said device including an arc-shaped body surrounding said tubular member in proximity to said circumferential weld, and two circumferential ends of said body. An attached clamp mechanism, a revolving frame provided inside the main body so as to be movable in a circumferential direction, a probe elevating mechanism provided on the revolving frame, a revolving mechanism provided on the main body for driving the revolving frame, and the probe An inspection device for a circumferential welded portion, comprising a probe which is exchangeably mounted on a lifting mechanism.