JP3224734B2 - Underwater cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater cutting device for a structure constructed underwater.

[0002]

2. Description of the Related Art As underwater structures, marine structures and the like are generally well known. For example, various underwater structures are provided in a nuclear power plant or the like by utilizing a radiation shielding function of water. These renovation and cutting work is preferably performed in water to prevent radiation exposure. As a technique for efficiently cutting such an underwater structure, a plasma cutting method or a laser cutting method has been proposed and implemented, but a secondary product, so-called dross, generated when performing these cutting methods is collected. Less attention has been paid to that.

[0003]

An example of an underwater structure used in a nuclear power plant as described above is a spent fuel storage rack. In recent years, there has been an increasing need for increasing the storage capacity of spent fuel in power plants, and the need for repair or remodeling of existing spent fuel storage racks has emerged. At the time of this renovation work, it is necessary to efficiently cut underwater fuel storage racks, which are generally made of stainless steel, using the aforementioned plasma cutting method or laser cutting method. Since the spent fuel storage rack mentioned above has already received and stored a large amount of spent fuel, during the above-mentioned renovation or remodeling work, all spent fuel in storage is transferred to another storage facility or the like. In order to carry it out, it is necessary to prepare equipment for it in advance, which is not practical. Therefore, it is desirable to take out only a minimum amount of spent fuel and carry out renovation work while keeping other fuels stored. For this purpose, it is necessary to prevent the dross from being diffused and dissipated around the dross generated when the fuel storage rack is cut underwater.
Otherwise, there is a problem that the spent fuel in storage is contaminated with the dross or the contained substance. Therefore, an object of the present invention is to provide an underwater cutting device that prevents generated dross from diffusing and dissipating around even when an underwater structure is cut using an underwater plasma cutting method or an underwater laser cutting method. Is what you do.

[0004]

According to the present invention, there is provided, in accordance with the present invention, a submersible cutting device which includes a support arm attached to an end of an arm of a manipulator, and a pivotally connected arm. A collection box detachably fixed to a member to be cut of an underwater structure, a feed mechanism pivotally attached to the same support arm, a tool head movably attached to the feed mechanism, and a tool A cutting torch attached to the head using a plasma or a YAG laser or the like, and a suction hose connected to the collection box and provided with a filter on the way, and the collection box is for cutting waste that is opened facing the cutting torch. When the inner space is defined and fixed to the member to be cut, the periphery of the opening of the inner space is pressed against the back surface of the member to be cut so as to receive generated dross without scattering. It is configured.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the cutting apparatus 10 shown in FIG. 1, a support arm 13 is attached to a distal end of a long arm 11 of a manipulator whose main body is placed on an upper portion (not shown). Then, the feed mechanism 20 is attached to the support arm 13.
Is pivotally mounted, and is pivoted when it is set on a plate member A which is a member to be cut of an underwater structure, as described later. The feed mechanism 20 mainly includes a main body frame 21 that also functions as a rail, a drive motor 23 for pivoting, a feed screw 25, and a drive motor 2 that rotates the feed screw 25.
Seven. The tool head 30 slidably fitted and attached to the main body frame 21 of the feed mechanism 20 has a nut (not shown) screwed to the feed screw 25 therein.
When the feed screw 25 is rotated by the drive motor 27, the tool head 30 is guided and moved to the right or left (in the drawing) by the main body frame 21. The tool head 30 also
It has a vertical slide 31 for supporting the cutting torch 15 and a drive motor 33 for driving the slide. Cutting torch 15
Uses laser light, and illustrations of a transmission fiber for sending the laser light, necessary gas supply pipes, and the like are omitted. The cutting torch 15 may use plasma. Although FIG. 1 shows a standard installation state of the cutting device 10, in order to further ensure the prevention of the scattering of the cutting waste, the scattering prevention device connected with the gas exhaust pipe 17 as shown by a two-dot chain line is shown. The box 19 may be attached so as to surround the cutting torch 15.

On the other hand, a collection box 40 is further provided on the support arm 13.
Are pivotally mounted similarly to the feed mechanism 20. Although its detailed structure will be described later, it has a main body box 41, a driving motor 43 for pivoting, pressing members 45, 46, and an air cylinder 47 for driving the pressing members 45. One end of the suction hose 60 is fitted and attached to the end of the main body box 41 where the air cylinder 47 is not provided. The suction hose 60 communicates with a filter unit and a pump as described later. If necessary, a remote observation device such as a lighting device or a television camera is also mounted on the long arm 11 of the manipulator.

Since the periphery of the plate material A is generally narrow in many cases, the state shown in FIG. That is, the feed mechanism 20 includes the drive motor 2
The tool head 30 is pivoted by 3 so as to be along the long arm 11 of the manipulator, and the tool head 30 is in a position where the cutting torch 15 is retracted. Further, the collection box 40 includes the feed mechanism 2
It is pivoted by the drive motor 43 so as to extend in the direction opposite to zero. In this manner, when the posture shown in FIG.
1 is to be moved in its longitudinal direction, the cutting device 1
The passing area of 0 is minimized, and it is possible to enter a narrow space.

When the plate material A comes to a predetermined position with respect to the cutting device 10, the feed motor 20 is driven by the drive motor 23.
Is pivoted about 90 degrees counterclockwise, and simultaneously or back and forth, the collection box 40 is pivoted about 90 degrees clockwise by the drive motor 43, and the plate material A is pressed by the pressing members 45, 45 of the collection box 40.
When it comes between 46, the state shown in FIG. 3 is obtained. In the collection box 40, as shown in a partially cutaway perspective view of FIG. 4, the main body box 41 defines a dross receiving space 49 which opens toward the cutting torch 15 and extends in the moving direction thereof. Is covered with a heat-resistant ceramic 51. Further, the main body box 4 surrounding the dross receiving space 49
A sealing material 53 made of a single-cell sponge is attached to the upper surface of 1 so as to be in close contact with the back surface of the plate material A. In the pressing member 45, a relief recess 45a is formed at a central portion to provide a clearance space for the cutting torch 15. The opposing pressing member 46 has the same structure. Then, when the state shown in FIG. 3 is reached, the air cylinder 47 is actuated, the plate A is sandwiched between the pressing members 45 and 46, and the collection box 40 and thus the cutting device 10 are fixed to the plate A. Thereafter, a cutting operation is performed as described later.

Next, the outline of the cutting operation performed by using the cutting device 10 having the above-described configuration and set on the plate material A will be described with reference to FIGS. 5 and 6 which are conceptual diagrams. As is clear from the figure, the underwater structure including the plate material A is provided in the pit P where the water B is stretched, and the plate material A is below the water surface. The sealing material 53 on the upper surface of the main body box 41 of the collection box 40 and the sealing materials 57 and 59 at the tips of the pressing members 45 and 46 define a closed space that is in close contact with the back surface and both side surfaces of the cut portion of the plate material A. To achieve. The suction hose 60 communicates with a pump unit placed on the upper floor of the pit P. The pump unit has a filter unit 61 and a pump 63, and a return hose 65 thereof.
Opens into the pit P. Then, first, the tool head 30 is moved, and the cutting torch 15 is first set at the position of the relief recess 45a of the pressing member 45, so that the cutting torch 15 can be cut. The distance between the surface of the plate material A and the cutting torch 15 is adjusted by moving the vertical slide 31 to adjust the height. If the pump 63 is driven in this state,
Water B in the pit P is sucked into 49 through the escape recess 45a. Then, the feed mechanism 20 is operated to send the tool head 30 holding the cutting torch 15 in the direction of the white arrow, that is, when the tool head 30 moves, the laser light from the cutting torch 15 hits the plate material A and cuts it. The cut secondary product generated at this time, that is, dross C, is
Together with the suction hose 60, the dross C is separated and removed by the filter unit 61, and only the water B is returned into the pit P. Therefore, the dross C is completely collected in the collection box 40, and does not scatter or scatter around. When the shatterproof box 19 is used as described above, a part of the gas such as the shielding gas or dross that has come out of the cutting torch 15 is trapped in the shatterproof box 19, and the gas exhaust pipe 17.
And the contamination of the surrounding water is prevented.

[0010]

As described above, according to the present invention,
Cutting is performed by installing a collection box with an internal space for cutting waste that opens to face the cutting torch of the underwater cutting device on the back side of the member to be cut, so that contamination of surrounding water or other objects during storage is prevented. The underwater cutting of the underwater structure can be efficiently performed while preventing the occurrence.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a working posture of a cutting device 10 according to an embodiment of the present invention.

FIG. 2 is a partial perspective view showing one posture of a mounting stage of the cutting device 10;

FIG. 3 is a partial perspective view showing another posture of the mounting stage of the cutting device 10;

4 is a partially cutaway perspective view showing a part of a main part of the cutting device 10. FIG.

FIG. 5 is an explanatory view conceptually showing a cutting operation state of the embodiment.

FIG. 6 is a sectional view conceptually showing a cutting operation state of the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 cutting device 11 long arm 13 support arm 15 cutting torch 17 gas exhaust pipe 19 scattered matter prevention box 20 feed mechanism 21 body frame 23 drive motor 25 feed screw 27 drive motor 30 tool head 31 vertical slide 33 drive motor 40 collection box 41 Body box 43 Drive motor 45, 46 Pressing member 47 Air cylinder 49 Dross receiving space 51 Heat resistant ceramic 53 Sealing material 60 Suction hose 61 Filter unit 63 Pump 65 Return hose

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI G21C 19/07 G21C 19/06 Q (72) Inventor Hiroshi Tanaka 1-1-1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industry Co., Ltd. Kobe Shipyard (56) References JP-A-8-160194 (JP, A) JP-A 62-137670 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21F 9/30 531 G21C 19/02 G21C 19/07

Claims (1)

(57) [Claims] 1. A support arm attached to an end of an arm of a manipulator, a collection box pivotally connected to the support arm and removably fixed to a member to be cut, and pivotally attached to the support arm. It has an attached feed mechanism, a tool head movably attached to the feed mechanism, a cutting torch attached to the tool head, and a suction hose connected to the collection box and provided with a filter on the way. The collection box defines a cutting waste internal space that opens to face the cutting torch, and when fixed to the member to be cut, the periphery of the opening of the internal space is on the back surface of the member to be cut. An underwater cutting device characterized by being pressed.