JPH0890222A - Under water welding device - Google Patents

Abstract

PURPOSE: To provide an under water welding device which can apply to a narrow part miniaturizing a torch part and can surely weld. CONSTITUTION: A skirt 7 composed of a filter material is arranged at the outside of the torch part 1 and a cover 10 water-tightly covering a torch supporting rod 6 of the torch part 1 is arranged at the upper end of this skirt 7. In the torch part 1, an electrode 2 shield gas supplying nozzle 3 welding material supplying nozzle 4 and arc monitoring device 5 are arranged. The skirt is fixed to the surrounding part of the welded repairing part 15 with a skirt supporting rod, and a cavity is developed in the welded repairing part by the work for shutting off the water at the outer part and the action for escaping the shield gas supplied from the shield gas supplying nozzle 3 by fining down. The arc is developed from the electrode 2 and the welded material 23 is supplied to the welded repairing part and the welded state is monitored with the arc monitoring device 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable, for example, for welding and repairing a welded portion between a control rod drive mechanism housing stub tube and a reactor pressure vessel in a reactor and the vicinity thereof in the presence of reactor water. Underwater welding equipment.

[0002]

2. Description of the Related Art As a method of repair welding in water,
Underwater covered arc welding by a diver is known,
For example, in repair welding of a welded portion in a reactor pressure vessel, there is a problem of radiation exposure of a diver due to the condition of high dose.

In order to solve this problem, an underwater welding apparatus as shown in FIG. 10 has recently been considered. In this underwater welding apparatus, a skirt 68 is attached to the peripheral portion of a welding torch portion 65 where an electrode 67 is located near the center of an opening 66.

The skirt 68 conforms to the shape of the welded portion 63 to shield water from the outside, and finely escapes the supplied shield gas to form a cavity in the welded portion 63. Then, the welding material 70 is supplied from the welding material supply nozzle 69 to the arc generated from the electrode 67 to perform welding, and the welding status is monitored by the arc monitoring device 71.

[0005]

In the above-mentioned underwater welding apparatus, the welding torch portion 65 is applied so that it can be applied to narrow spaces.
Only the skirt 68 and the skirt 68 are installed in the weld, and the torch drive mechanism and the welding material supply device are arranged on the control rod drive mechanism housing.
68 is fixed so as to move together with the torch portion 65.

Therefore, in order to always ensure the sealing of the repaired portion during the welding operation, it is fixed to the torch 62 at the welding start position as shown in FIG. 11 (a) or at the welding end position shown in FIG. 11 (b). The skirt 68 must surround the repair weld.

Therefore, the length of the skirt 68 in the welding direction must be at least twice the length of the repair weld in the welding direction 64.
There are problems that the torch part 65 becomes large and cannot be applied to narrow spaces, and if the shape of the welded part 63 is curved, it cannot fit in the skirt 68 and water invades, making it impossible to perform welding work.

The present invention has been made to solve the above problems, and an object thereof is to downsize the torch so that it can be applied to a narrow portion, and a cavity is maintained during the movement of the torch to ensure welding. It is to provide an underwater welding apparatus.

[0009]

According to the present invention, a torch portion and a skirt are installed in a connecting portion, and a torch portion drive mechanism and a welding material supply device are arranged on, for example, a control rod drive mechanism housing. The movable torch, the skirt that is a filter material that allows the shield gas to pass but the water does not pass, and is mounted between the torch and the skirt so as to shield the water, and the torch part moves three-dimensionally. The present invention provides a submersible welding device that facilitates welding of a welded portion between a control rod drive mechanism housing stub tube and a reactor pressure vessel and its vicinity by adopting a cover that does not interfere with the welding. .

[0010]

In the underwater welding apparatus having the above structure, since the fixed skirt only surrounds the repaired part without hindering the movement of the torch part which moves in the three-dimensional direction, the skirt itself is slightly larger than the repaired part. The size of the torch can be kept small and the skirt is not moved, so that the movement of the torch does not lose the water shielding.

[0011]

EXAMPLE An example of the underwater welding apparatus according to the present invention will be described with reference to FIGS. 1 to 9. The underwater welding apparatus of this embodiment uses a tetrafluoroethylene resin for the skirt, a bellows for the cover, and has a welding material supply mechanism and an arc monitoring device.

1 and 2 show the cover to the tip of the underwater welding apparatus, and FIG. 3 is an overall view. FIG.
9 are top views of the torch part drive mechanism 17 among the above-mentioned underwater welding devices, and FIG. 5 is a clamp device 16 and a rotation drive part.
18, FIG. 6 is a radial drive unit 19, FIG. 7 is a z-axis drive unit 20, FIG. 8 is a torch axial drive unit 21, and FIG. 9 is a sectional view showing a welding material feeder 22.

1 and 2, the torch portion 1 is composed of an electrode 2, a shield gas supply nozzle 3, a welding material supply nozzle 4 and an arc monitoring device 5. The skirt 7 is attached to the clamp base 27 below the moving mechanism 17 of the torch.
It is fixed via a skirt support rod 9. Skirt 7
Is manufactured in such a size that the movement of the torch part 1 is not hindered according to the shape and size of the repair part.

The material of the skirt 7 is tetrafluoroethylene resin, which has the property of allowing water molecules to pass through but shielding gas molecules to pass through. A bellows cover 10 is attached to the upper portion of the skirt 7.

A torch support rod 6, a welding material supply pipe 11, an arc monitoring line 12, a torch cooling water pipe 13 and a shield gas supply pipe 14 penetrate through the upper portion of the cover 10, and the skirt 7 is formed from the penetrated portion. The inside of the is sealed to prevent water from entering.

The torch portion 1 is connected to a torch portion moving mechanism 17 via a torch portion supporting rod 6. As shown in FIG. 4, the torch portion moving mechanism 17 is a clamp device 16 for fixing itself to the control rod drive mechanism housing 24, and the torch portion 1 is.
A rotational drive unit 18 for rotating the control rod drive mechanism housing 24, a radial drive unit 19 for moving in the radial direction, a z-axis drive unit 20 for moving up and down, and a torch axial direction drive unit 21 for moving in the torch axial direction. It consists of

A welding material feeder 18 for supplying the welding material 23 to the torch portion 1 is fixed to the upper part of the torch portion moving mechanism 17 so as to rotate together with the welding device. The power supply, control device, and arc monitor are placed outside the reactor pressure vessel 26, and are connected to the torch moving mechanism 17 by electric wires covered with insulation.

The clamp device 16 and the rotary drive unit 18 are shown in FIG. Control rod drive mechanism housing 24 with clamp device 16
The fixation to is as follows. First, the clamp base 27 of the welding device is placed on the control rod drive mechanism housing 24.
Next, when air is sent into the air cylinder 28, the cylinder rod 29 moves downward.

Then, the clamp trigger 31 at the tip of the cylinder rod 29 spreads the clamp piece 31 outwardly, and the spreading force fixes the entire welding device to the control rod drive mechanism housing 24.

The rotary drive unit 18 includes a rotary motor 32 for generating a rotary motion, a rotary motor gear 33 for transmitting the rotary motion, a mechanical drive shaft 34, a rotary gear 35 for rotating the welder, and a rotary table 36 on which a welding device is mounted. It consists of and.

The rotary motor 32 is fixed to the rotary table 36, the rotary gear 35 is fixed to the clamp base 27, and the rotary table 36 is fixed to the clamp device 16 via bearings 37 so that they can rotate.

When the rotary motor rotates the rotary drive shaft 34, the rotary motor gear 33 rotates, and the rotary motor gear 33 meshes with the rotary gear 35, so that the motor side rotates with respect to the control rod drive mechanism housing 24. This causes the welding device to rotate.

FIG. 6 shows the radial drive section 19. Drive unit 19
Is fixed to the rotary table 36 in FIG. The rotation of the radial motor 38 causes the radial motor gear 39 to rotate the radial pinion gear 41 via the radial drive shaft 40.

Since the pinion gear 41 meshes with the radial rack 42, when the radial pinion gear 41 rotates by the rotation of the radial motor 38, the radial slider 43 to which the radial rack 42 is fixed moves in the radial direction. Moving. Radial motor across radial drive shaft 40
A radial potentiometer 44 is mounted on the side opposite to 38, and the position of the radial slider 43 can be confirmed.

FIG. 7 shows the z-axis drive unit 20. z-axis drive unit 20
Is a z-axis motor 45 fixed on the radial slider 43 of FIG. 6 as a drive source, a z-axis screw shaft 46 and a z-axis nut 47 for converting the rotation of the motor into vertical movement, and a z-axis moving in the z-axis direction. It is composed of a slider 48 and a z-axis potentiometer 49 for confirming the movement position.

The z-axis screw shaft 46 is connected to the z-axis motor 45,
The shaft nuts 47 are fixed to the z-axis sliders 48, respectively, and the z-axis screw shaft 46 and the z-axis nut 47 mesh with each other. When the z-axis screw shaft 46 rotates due to the rotation of the z-axis motor 45,
The z-axis nut 47 and the z-axis slider 48 move in the z-axis direction. The movement position is confirmed by the z-axis potentiometer 49 shown in FIG.

FIG. 8 shows the torch axial drive unit 21. The torch axial drive unit 21 is fixed to the z-axis slider 48 of FIG.
A torch shaft motor 50 serving as a drive source, a torch shaft motor gear 51 that transmits the driving force, a torch shaft drive shaft 52, and a torch shaft pinion gear 53 that converts the rotation of the motor into forward and backward movement.
And a torch shaft rack 54, a torch shaft slider 55 that moves in the torch shaft direction, and a torch shaft potentiometer 56 that confirms the moving position.

The torch shaft motor gear 51 rotates the torch shaft pinion gear 53 via the torch shaft drive shaft 52.
Since this torch shaft pinion gear 53 meshes with the torch shaft rack 54 adjusted so as to face the torch shaft direction,
Rotation of torch shaft motor 50 causes torch shaft pinion gear 53
When the tool rotates, the torch shaft rack 54 and torch shaft slider
55 moves in the torch axis direction.

The torch shaft slider 55 is attached to the torch shaft support rod 6.
Has been fixed. A torch shaft direction potentiometer 56 is attached to the opposite side of the torch shaft motor 50 with the torch shaft drive shaft 52 interposed therebetween, and the position of the torch shaft slider 55 can be confirmed. The torch unit 1 can move in the three-dimensional direction near the welded portion by the action of each drive unit described above.

As shown in FIG. 3 and FIG. 9, the welding material feeder 22 is fixed to the rotary table 36 via the support plate 61, and for fixing the reel 60 around which the wire-shaped welding material 23 is wound. Reel bracket 59, welding material supply motor 57 for supplying welding material 23, and welding material supply gear box
It consists of 58 and.

The welding material 23 is fed from the reel 60 to the gear box 58.
It passes through the inside and enters the welding material supply pipe 11 of the urethane tube which continues to the torch part 1. The gear sandwiching the welding material 23 is rotated by the rotation of the welding material supply motor 57, and the welding material 23 is fed.

In the above embodiment, however, the skirt 7 is fixed to the weld repair part 15 and the shield gas is supplied from the shield gas supply nozzle 3. The shielding gas removes water from the skirt opening 8 and, after completely removing the water, gradually leaks from the skirt opening to form and maintain a cavity inside the skirt 7.

Even if the skirt opening 8 is completely aligned with the welded portion and it is difficult for the shielding gas to escape, the skirt 7
Is formed of a filter material that does not allow water molecules to pass through, but is made of, for example, tetrafluoroethylene resin.

Therefore, the shield gas does not escape through the skirt 7 and the skirt 7 does not bulge too much and the cavity is not destroyed. After the cavity is formed inside the skirt 7, an arc is generated from the electrode 2 and the welding material supply nozzle 4
Then, the welding material 23 is supplied to the welding repair section 15 to start welding.

Along with this, the torch portion 1 moves inside the skirt 7 to perform repair welding. These welding conditions are monitored by the arc monitoring device 5. Since the cover 10 maintains the function of shielding water while allowing the movement of the torch portion 1, the sealing performance is not lost due to the movement of the torch portion.

[0036]

According to the present invention, a cavity is formed by the skirt, the cover and the shielding gas, and only the torch portion can move inside the skirt.
If defects such as cracks occur in the weld between the control rod drive mechanism housing stub tube and the reactor pressure vessel or in the vicinity of the weld, prompt and reliable welding can be performed by remote control from the water without draining the water from the reactor. Since it can be performed, it is possible to reduce the exposure of workers and the work time.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a partial side view of a main part of an embodiment of an underwater welding apparatus according to the present invention.

FIG. 2 is a side view of the underwater welding apparatus shown in FIG. 1 in a perspective view with a part cut away.

FIG. 3 is a perspective view showing a state where the bottom portion of the reactor pressure vessel is welded by the underwater welding apparatus according to the present invention.

FIG. 4 is a top view showing a moving mechanism in FIG.

5 is a vertical cross-sectional view showing the clamp device and the rotation drive unit in FIG.

FIG. 6 is a vertical cross-sectional view showing a part of the radial direction driving portion in FIG.

7 is an elevation view showing a part of the z-axis drive unit in FIG. 3 in a vertical cross section.

FIG. 8 is a perspective view showing a part of the torch axial drive unit in FIG. 3 in a vertical cross section.

9 is a vertical cross-sectional view showing the welding material feeder in FIG.

FIG. 10 is a perspective view schematically showing a use state of a conventional underwater welding apparatus.

11A is a schematic sectional view showing a welding start position in FIG. 10, and FIG. 11B is a schematic sectional view showing a welding end position of FIG.

[Explanation of symbols]

1 ... Torch part, 2 ... Electrode, 3 ... Shield gas supply nozzle, 4 ... Welding material supply nozzle, 5 ... Arc monitoring device, 6
... Torch support rod, 7 ... Skirt, 8 ... Skirt opening, 9 ... Skirt support rod, 10 ... Cover, 11 ... Welding material supply pipe, 12 ... Arc monitoring line, 13 ... Torch cooling water pipe, 14 ... Shield gas Supply pipe, 15… Welding repair section,
16 ... Clamping device, 17 ... Torch moving mechanism, 18 ... Rotation drive unit, 19 ... Radial drive unit, 20 ... Z-axis drive unit, 21 ... Torch axial drive unit, 22 ... Welding material feeder, 23 ... Welding material,
24 ... Control rod drive mechanism housing, 25 ... Control rod drive mechanism housing Stub tube, 26 ... Reactor pressure vessel, 27 ... Clamp base, 28 ... Air cylinder, 29 ... Cylinder rod, 30 ... Clamp trigger, 31 ... Clamp piece, 32 ... rotary motor, 33 ... rotary motor gear, 34 ... rotary drive shaft, 35 ... rotary gear, 36 ... rotary table, 37 ... bearing, 38 ... radial motor, 39 ... radial motor gear, 40
… Radial drive shaft, 41… Radial pinion gear,
42 ... Radial rack, 43 ... Radial slider, 44 ... Radial potentiometer, 45 ... Z-axis motor, 46 ... Z-axis screw shaft, 47 ... Z-axis nut, 48 ... Z-axis slider, 49 ... Z
Axis potentiometer, 50 ... Torch axis motor, 51 ... Torch axis motor gear, 52 ... Torch axis drive shaft, 53 ... Torch axis pinion gear, 54 ... Torch axis rack, 55 ... Torch axis slider, 56 ... Torch axis potentiometer, 57 ... Weld Material supply motor, 58 ... Welding material supply gear box, 59 ...
Reel bracket, 60 ... Reel, 61 ... Strut plate, 62 ... Torch, 63 ... Welding part, 64 ... Welding direction, 65 ... Welding torch part, 66
… Opening part, 67… Electrode, 68… Skirt, 69… Welding material supply nozzle, 70… Welding material, 71… Arc monitoring device.

Claims (9)

[Claims] 1. A torch part which is movable in three dimensions, and a filter which surrounds the torch part and which fits into the shape of the periphery of the repair part to eliminate water inside to selectively pass only gas forming a cavity. A skirt made of material,
An underwater welding apparatus comprising: a cover that covers the torch portion and is attached above the skirt. 2. The skirt is fixed to the welding repair portion side independently of the movement of the torch portion, and a moving mechanism for moving the torch portion in a three-dimensional direction inside the skirt is provided. The underwater welding apparatus according to claim 1. 3. The underwater welding apparatus according to claim 1, wherein a welding material supply mechanism for supplying a welding material is provided in the welding torch. 4. The underwater welding apparatus according to claim 1, wherein the welding torch and the welding material supply mechanism have a driving portion driven by an electric motor. 5. The underwater welding apparatus according to claim 1, further comprising a gas supply passage for supplying a gas having a function of pushing out water existing in the welding torch. 6. The torch portion is supported by a torch support rod, and a cover which covers the torch support rod and is provided above the skirt is formed of a bellows.
Underwater welding device described. 7. The underwater welding apparatus according to claim 1, wherein the filter material forming the skirt is made of tetrafluoroethylene resin. 8. The underwater welding apparatus according to claim 1, wherein the torch portion is provided with an arc monitoring device for monitoring a welding arc. 9. The underwater welding apparatus according to claim 1, wherein the arc monitoring device comprises a fiberscope.