JPH0635070B2 - Underwater plasma arc cutting torch - Google Patents

Description

Description: INDUSTRIAL FIELD OF APPLICATION The present invention relates to underwater cutting for disposal of highly activated materials,
Alternatively, it relates to an underwater plasma arc cutting torch used for underwater cutting for dismantling an offshore structure or an underwater structure.

[Prior Art] Conventionally, no plasma arc cutting torch has been developed specifically for underwater use.

All known conventional plasma arc cutting torches are for cutting in air.

If the above-mentioned torch for cutting in the air is used for cutting in water, the following problems arise.

[Problems to be Solved by the Invention] In order to divert the above-mentioned air cutting torch for underwater cutting, it is necessary to apply a waterproof treatment such as winding a vinyl tape around each connecting portion, and to force water cooling. Therefore, the entire torch becomes large, and remote operation is required to use it for underwater cutting of high activation materials, but when the entire torch becomes large, it is difficult to perform remote operation. Further, since it is not exclusively used for underwater, it has a complicated structure and is poor in maintainability when used underwater.

Therefore, the present invention aims to provide a plasma arc cutting torch exclusively for underwater, which eliminates the water cooling system, simplifies and downsizes the torch structure, and facilitates remote operation.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention attaches a watertight outer cylinder having a nozzle to the front end of an insulative holder in a watertight manner, and arranges the outer cylinder inside the outer cylinder. A cable in which the above-mentioned electrode is held by a power feeder supported by the holder, and a high-voltage wire mounting metal fitting which is electrically connected to the outer cylinder is provided in the holder, and a connecting rod attached to the tip is connected to the power feeder. And a rubber plug held through a high-voltage wire with a connecting rod connected to the high-voltage wire fitting at the tip, and a plasma gas hose opening in the internal space of the holder, so that the rubber plug can be detached from the rear from the holder. And a gas passage is formed between the inner space of the holder and the nozzle.

[Operation] The plasma current and the high-voltage current from the cable are surely separated by the insulator, and the electrodes and the nozzle are energized, so that the plasma gas can be flowed properly. Further, since the whole torch is used by being buried in water, the outer cylinder and nozzle of the torch are directly water cooled, so that it is not necessary to specially provide a forced water cooling system.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a holder 3 made of an insulating material such as Teflon for supporting the rear end of the outer tube 1 of the torch is provided with a concave portion 3 having a tapered surface in the rear portion thereof. A tapered rubber stopper 4 supported through an electric wire 6 and a plasma gas hose 7 (see FIG. 2) is fitted, a plate metal fitting 8 is arranged on the rear surface of the rubber plug 4, and a nut 9 is used to insert the plate metal fitting 8 in between. By pushing the rubber plug 4 into the holder 2, the watertightness of each supporting portion of the cable 5, the high voltage electric wire 6, the plasma gas hose 7, the concave portion 3 and the taper portion of the rubber plug 4 is maintained. A power supply body 10 having a cylindrical shape at the axial center of the holder 2 and having a gas passage hole 11 at the front end thereof.
And the connecting rod 12 is inserted into the rear side of the power supply body 10, and the front side of the power supply body 10 has a length projecting forward from the front end of the holder 2 for gas passage. The rear end portion of the cylindrical power supply body 13 having the hole 14 is screwed, the cable 5 is connected to the connecting rod 12 by the fastening metal fitting 15, and the connecting rod 12 is radially arranged from the outside of the holder 2. Inserted set screw 16,1
16 out of 7 is connected to the power supply 10, and the cutting current of the plasma mark is the cable 5, the connecting rod 12, the set screw 16, the power supply.
It is made to flow to the power feeding body 13 via 10.

In addition, the holder 2 has an O-ring from the space of the recess 3.
The connecting rod 19 is inserted from the inner space at a position off the axis with the interposition of 18 and the high voltage electric wire 6 is connected to the connecting rod 19, and the front end of the connecting rod 19 is moved in the radial direction of the holder 2. It is inserted in the high-voltage electric wire mounting bracket 20 inserted in, and is supported by the set screw 21, and the mounting bracket 20 is fixed by the screw 23 inserted by sandwiching the high-voltage conductive piece 22 from the front side of the holder 2, and the plasma pilot arc The high-frequency current for generating the high-voltage electric wire 6 is connected to the connecting rod 19, the high-voltage electric wire mounting bracket 20, the screw 23,
Flow through the high-voltage conductive piece 22 to the outer cylinder 1.

The distal end of the electrode 24 is inserted into the tip of the power supply body 13,
The electrode 24 is fixedly held on the power supply body 13 by the tightening ring 25.
An insulating link-shaped member 26 made of ceramic or the like having a gas passage 27 parallel to the axial direction and arranged inside the outer cylinder 1 is fitted in the middle of the electrode 24, and An insulative cylindrical member 28 made of ceramic or the like is disposed inside and between the ring-shaped member 26 and the holder 2 via O-rings 29 and 30, and between the power feeder 13 and the cylindrical member 28. A space for gas flow is formed, and further, at the tip of the outer cylinder 1,
The nozzle 31 is attached with the O-ring 32 interposed.

The gas hose 7 is opened in the space inside the recess 3 of the holder 2 and its tip does not come out of the rubber plug 4 as shown in FIG.

In the figure, arrow 33 indicates the flow of plasma gas, and 34 indicates the outer cylinder 1.
An insulating cover 35 is provided on the outside of the device, 35 is an O-ring for sealing the set screw 17, and 36 is a spring pin for preventing the power supply body 13 from rotating with respect to the holder 2.

When it is used by being buried in water for cutting a structure or the like in water, the rear portion of the holder 2 is the comb stopper 4, the set screw 16 is the O ring 35 of the set screw 17, and the connecting rod 19 is the O ring. 18, O-rings 30 and 29 between the holder 2 and the outer cylinder 1, and between the outer cylinder 1 and the cylindrical member 28, and the nozzle.
Water-tightness is ensured by the O-ring 32 at the 31st part, so that water does not enter inside.

The cutting current of the plasma arc which is passed through the cable 5 at the time of cutting is supplied to the electrode 24 from the tightening metal fitting 15 through the connecting rod 12, the set screw 16, and the power supply members 10 and 13. On the other hand, high voltage electric wire 6
A high-frequency current for generating a pilot arc of plasma passed through is supplied to the nozzle 31 via the connecting rod 19, the high-voltage wire mounting bracket 20, the screw 23, the high-voltage conductive piece 22, and the outer cylinder 1.

Since the plasma current and the high frequency current are insulated by the holder 2, which is an insulating material, the cylindrical member 28, and the ring-shaped member 26, they are reliably separated.

The plasma gas passes through the gas hose 7, passes through the hole 11 of the power supply body 10 and enters the power supply body 13 from the inner space of the holder 2.
Further, the gas is discharged from the hole 14 through the gas passage 27 of the ring-shaped member 26 from the inside of the cylindrical member 28, and is discharged from the nozzle 31 as shown by an arrow.

Since the outer cylinder 1 and the nozzle 31 are directly water-cooled during the cutting operation in water, it is not necessary to provide a water cooling system.

The nozzle 31, which is the most exhausted in plasma cutting, can be easily separated from the outer cylinder 1 as in the conventional air plasma cutting torch, and the consumed electrode 24 removes the outer cylinder 1 from the holder 2 and the tightening ring 25. It can be easily replaced by loosening the screw part of.

When separating the cable 5 and the high-voltage electric wire 6 from the torch body side such as the outer cylinder 1 and the like, the set screws 16 and 17 are removed, the set screw 21 is removed, and the nut 9 is further removed.
At the same time, it can be removed from the holder 2, and maintenance can be easily performed.

[Advantages of the Invention] As described above, according to the underwater plasma arc cutting torch of the present invention, the outer cylinder having the nozzle watertightly attached to the tip thereof is watertightly attached to the insulating holder, and the electrode is arranged inside the outer cylinder. To the power supply supported by the above holder,
Further, the holder is provided with a high-voltage electric wire mounting bracket capable of energizing the outer cylinder, a cable with a connecting rod attached to the tip, a high-voltage electric wire with a connecting rod attached to the tip, and a rubber plug holding a plasma gas hose, respectively. The connection rod at the end of the cable is connected to the power supply, the connection rod at the end of the high-voltage wire is connected to the high-voltage wire fitting, and the plasma gas is discharged from the inner space of the holder between the outer cylinder and the electrode. Since it is discharged from the nozzle through the nozzle, the outer cylinder and nozzle are directly water-cooled during use, and the water cooling system such as the conventional plasma arc cutting torch used in the air can be omitted, and the cutting performance is improved. It can be made smaller and lighter without dropping it, which enables underwater cutting of radioactive materials that require remote control or underwater deep sea cutting. Is optimum as a torch device,
In addition, excellent effects such as a simple structure and good maintainability can be obtained.

[Brief description of drawings]

1 is a sectional view of an underwater plasma arc cutting torch of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view of FIG.
III-III sectional view, FIG. 4 is a sectional view showing a state in which a gas hose is attached to a rubber plug. 1 is an outer cylinder, 2 is a holder, 3 is an internal space, 4 is a rubber stopper,
5 is a cable, 6 is a high voltage electric wire, 7 is a plasma gas hose, 10 is a power feeder, 12 is a connecting rod, 13 is a power feeding member, 16 and 17 are set screws, 19 is a connecting rod, 20 is a high voltage electric wire fitting, and 22 is A high-voltage conductive piece, 23 is a screw, 24 is an electrode, and 31 is a nozzle.

Claims (1)

[Claims] 1. A watertight outer cylinder having a nozzle attached to the tip thereof in a watertight manner is watertightly attached to the front side of an insulative holder, and an electrode arranged inside the outer cylinder is held by a power feeder supported by the holder, and The holder is provided with a high-voltage wire mounting bracket that is connected to the outer cylinder so that it can be energized, and a cable with a connecting rod connected to the power supply body is attached to the tip, and a connecting rod connected to the high-voltage wire attaching bracket is attached to the tip. High-voltage power line,
A rubber plug held through a plasma gas hose opening in the inner space of the holder is fitted to the holder so that it can be detached from the rear, and a gas passage is formed between the inner space of the holder and the nozzle. Underwater plasma arc cutting torch characterized by