JPH0675775B2 - Underwater welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to an underwater welding apparatus used, for example, for repairing a lining tank.

(Prior Art) For example, a nuclear power generation facility has a lining tank in which a lining plate such as a metal plate is lined on a concrete wall like a fuel storage pool. In such a lining tank, a lining plate is stretched all over the inner wall surface of the concrete wall, and this lining plate prevents leakage of stored water in the tank.

By the way, in the lining tank, although stored products are moved, the lining plate may be damaged due to a collision, a drop, or the like during the movement, and cracks or the like may occur. In particular, for those that require the utmost care regarding water leakage, such as the spent fuel storage pool of a nuclear reactor, if cracks occur in the lining plate, it is necessary to take appropriate measures urgently.

In this case, in the cracks that occurred in the lining plate,
It is most desirable to cover the cracked part with a patch and continuously weld the outer line part of this patch to the lining plate by water welding, but in the past, after draining the water in the lining tank to the damaged part, the worker concerned It is necessary to go to the damaged part and perform repair welding.

(Problems to be Solved by the Invention) However, in the above-described method, if a high radiation dose such as spent fuel is stored in the lining tank, the worker may be exposed to radiation. , It is necessary to move the spent fuel to another place, or to drain the water if there is no place to move and to install radiation shielding equipment, which requires a huge amount of time for repair work.

The present invention has been made in response to such a conventional situation, it is possible to quickly weld a patch to a cracked portion of a lining plate by remote control from above the water without draining water in the lining tank. It is an object of the present invention to provide an underwater welding apparatus capable of reducing the exposure of workers and the work time.

[Structure of the Invention] (Means for Solving Problems) That is, the underwater welding apparatus of the present invention includes a chamber having an opening and a packing arranged at a peripheral portion of the opening,
A patch support mechanism for bringing the patch into contact with the portion to be welded through the opening, a welding torch having a drive mechanism for moving the arc position along the peripheral edge of the patch, and a filler material is supplied to the welding position by the arc. A filler material feeding mechanism, an arc monitoring mechanism for monitoring the arc, a gas injection mechanism that replaces water in the chamber with a gas, and the chamber is pressed to bring the packing into close contact with the periphery of the welded portion. And a chamber holding mechanism for allowing the chamber to be held.

(Operation) In the underwater welding apparatus of the present invention configured as described above, the underwater welding operation can be performed by remote operation from above the water.

Therefore, without draining the water in the lining tank, the patch can be brought into contact with the cracked portion of the lining plate and quickly welded by remote control from above the water, reducing the exposure of workers and shortening the working time. Can be planned.

(Embodiment) Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

The figure shows an underwater welding apparatus according to an embodiment of the present invention.
In the underwater welding apparatus 1 of this embodiment, the cylindrical chamber 2
Has an opening 2a formed at the bottom thereof, and a packing 2b for preventing water from entering the chamber 2 is fixed to the peripheral surface of the opening 2a by an adhesive, which is in contact with a surface near the welded portion. ing.

A chamber holding mechanism 3 is fixed to the outside of the upper surface of the chamber 2 so that the chamber 2 can be moved to an arbitrary position by operating from above the water, and the chamber is pressed against a welded portion with a predetermined pressure during welding.

A watertight electric motor 4 is fixed to the inside of the upper surface of the chamber 2. A speed change mechanism 5 for reducing the rotation of the electric motor 4 is connected to the electric motor 4, and a speed change output shaft 5a of the speed change mechanism 5 is connected to the speed change mechanism 5. The rotating disk 6 is connected so as to be integrally rotatable. A watertight cabtyre cable or the like is used for the conductor 4a of the electric motor 4.

At the eccentric position of the rotating disk 6, the welding torch position adjusting mechanism 7, the filler material feeding mechanism 8, and the arc monitoring mechanism 9 are fixed at positions where they do not interfere with each other.

The welding torch position adjusting mechanism 7 is composed of a watertight electric motor 7a, a speed change mechanism 7b and a slide 7c.
A welding torch 10 is fixed to the slide 7c with a plurality of bolts and the like, and the welding torch 10 is configured so that its position can be adjusted by the slide 7c. And welding torch 10
Is configured to perform fillet welding on a welded portion while rotating at a constant radius by the rotation of the rotary disc 6.

Further, the filler material feeding mechanism 8 is an electric motor 8a having a watertight structure.
The transmission mechanism 8b is attached to the welding torch 10 by the wire feeding pinch roller attached to the output shaft of the transmission mechanism 8b.
The arc monitoring mechanism 9 is configured to supply the filler material 8c to the tip end portion, and the arc monitoring mechanism 9 includes a television camera 9a, a welding torch 10, and a fiberscope 9b having a light receiving portion disposed near the tip end portion. Then, the filler material feeding mechanism 8 and the arc monitoring mechanism 9 rotate the rotating disc 6 to cause the welding torch 10 to move.
It is rotated while maintaining a constant relative position to.

A patch support mechanism 1 for supporting a patch 11 in which a plug 11a is provided on the center of one side surface of the rotating disk 6 on the lower side of the rotation center of the rotating disk 6, that is, on the extension line of the axis of the variable speed output shaft 5a.
2 is installed.

The patch support mechanism 12 is fixed downward at the center of rotation of the rotary disc 6, and is connected to an air cylinder 13 that presses the patch 11 against a welded portion and a tip of the air cylinder 13 via a metal fitting 14. Coupler 15 that holds plug 11a of patch 11
Fixed to the metal fitting 14 and plugged from the coupler 15 after welding
It is composed of an air cylinder 16 for separating 11a.

A spring 16a is inserted in the air cylinder 16 so that the plug 11a can be separated from the coupler 15 after welding even if air is lost. Also, coupler 15
Is composed of several small balls, a sleeve for pressing the balls, a spring and the like so that the plug 11a can be easily attached and detached.

A gas injecting mechanism 17 including a nozzle 17a for injecting gas into the chamber 2 and a nozzle 17b for removing water pushed out by the gas is provided in a lower portion of the side surface of the chamber 2.
Are arranged.

The underwater welding apparatus 1 of this embodiment having the above-described configuration welds as follows when it is detected that the crack portion 23 is generated in the lining plate 22 in a state where the water 21 is stored in the lining tank 20, for example. Do.

That is, first, the underwater welding apparatus 1 is suspended from the lining tank 20 through the chamber holding mechanism 3 into the lining tank 20. In this case, the patch 11 is previously gripped by the coupler 15 via the plug 11a.

Then, after fixing the underwater welding apparatus 1 at a predetermined position in the water 21, a gas such as argon is injected into the chamber 2 from the nozzle 17a of the gas injection mechanism 17, and the water in the chamber 2 is drained from the nozzle 17b. Since this operation cannot remove the thin water 21 left on the bottom surface of the lining plate 22, the heated gas is then injected from the nozzle 17a to completely dry the water on the surface of the lining plate 22.

After confirming that the water is completely removed by the arc monitoring device 9, the gas injection is stopped, the air cylinder 13 is operated, and the patch 11 is pressed against the lining plate 22. Further, the welding torch position adjusting mechanism 7 is operated while monitoring with the arc monitoring device 9 to set the welding torch 10 at a predetermined position.

After that, the electric motor 4 is operated to rotate the rotary disk 6 via the variable speed output shaft 5a. As a result, the welding torch 10, the filler material feeding device 8, and the arc monitoring device 9 rotate around the patch 11, so that a welding power source (not shown) is activated, and the welding torch 10 causes the periphery of the patch 11 and the lining plate 22 to operate. Let the quick fillet weld between and.

At the time of welding, an inert gas such as argon is injected into the chamber 2 from the nozzle 17a, and pressure is applied so that ambient water does not flow into the chamber 2.

When the welding work is completed, the welding power source section, the filler material feeding device 8,
The electric motor 4 is stopped, the air cylinder 16 is operated to separate the coupler 15 from the plug 11a, and the underwater welding apparatus 1 is pulled up from above the lining tank 20 via the chamber holding mechanism 3.

That is, in the underwater welding apparatus 1 of this embodiment, when a crack 23 or the like is generated in the lining plate 22, the underwater welding can be quickly and remotely performed by remote operation from above the water without draining the water in the lining tank 20 unlike the conventional case. It can be done reliably.

[Advantages of the Invention] As described above, in the underwater welding apparatus of the present invention, when a cracked portion or the like occurs in the lining plate, it is possible to quickly perform remote operation from above the water without draining water in the lining tank as in the conventional case. Moreover, since the patch and the lining plate can be reliably welded, it is possible to reduce the exposure of the worker and the working time.

[Brief description of drawings]

FIG. 1 is a sectional view showing an underwater welding apparatus according to an embodiment of the present invention. 2 ... Chamber 2a ... Opening 2b ... Packing 3 ... Chamber holding mechanism 6 ... Rotating disk 8 ... Welding material feeding mechanism 9 ... Arc monitoring device 10 ... Welding torch 11 ... Patch 12 ... … Patch support mechanism 17 …… Gas injection mechanism

Claims (1)

[Claims] 1. A chamber having an opening and a packing arranged at a peripheral portion of the opening, a patch support mechanism for bringing a patch into contact with a welded portion from the opening, and an arc position moved along the peripheral portion of the patch. A welding torch having a driving mechanism for driving, a filler material feeding mechanism for supplying a filler material to a welding position by the arc, an arc monitoring mechanism for monitoring the arc, and replacing water in the chamber with a gas An underwater welding apparatus, comprising: a gas injection mechanism for controlling the chamber, and a chamber holding mechanism for pressing the chamber to bring the packing into close contact with the periphery of the welded portion.