JP3006412B2 - Underwater processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for processing underwater, and more particularly to cutting, grinding, welding, and surface treatment for installation, repair, and processing of related equipment such as nuclear equipment, ships, and bridges. Related to underwater processing equipment.

[0002]

2. Description of the Related Art Conventionally, when processing a metal or non-metal in water, for example, in the case of underwater welding, a wet method of performing covered arc welding in an atmosphere that does not exclude water tends to cause defects such as blow holes in a joint portion. There was a problem with reliability. Also,
In the case of the dry method, in which the entire welding area is covered with a drainage chamber and the water is replaced with air or shielding gas and the on-land welding method is applied as is, a drainage chamber according to the shape of the workpiece is required. Therefore, the equipment required great expense.

[0003] Therefore, a local dry method (hereinafter referred to as a local shield method) for forming a cavity in which water in a processed portion is locally removed and performing processing such as welding and surface treatment in the cavity is used in underwater processing. It has become mainstream.

[0004] In the above-mentioned processing by the local shield method, it is important to stably remove water from the inside of the local shield, and many methods have been proposed in this regard. For example, in JP-A-49-79939, a shield gas nozzle is tripled, a shield gas is supplied from a first radiation nozzle, a high-speed jet of gas is supplied from a second radiation nozzle, and a high-speed jet of water is supplied from a third radiation nozzle. And a method for forming a stable gas phase region in the shield is disclosed. In addition, 55
JP-A-116785 discloses a welding torch having a skirt-shaped partition member made of carbon fiber or the like at a skirt of a local shield. Even with these methods, a processed part of sufficient quality for ordinary underwater processing applications could be obtained.

[0005]

However, in fields such as nuclear power-related equipment where there is a strong demand for improving the quality of the processing section, a trace of water remaining in the local shield becomes a problem. Also,
It is desirable to be able to obtain highly reliable processed parts even in general fields such as repair of ships and bridges. Ultimately, it is most desirable to obtain a machined part as close as possible to the machined part obtained by using the dry method in which the entire weld is covered with a discharge chamber and the water is replaced with air or shielding gas. Technology has been difficult to achieve. JP
In the invention disclosed in JP-A-49-79939, a water curtain is formed by a high-speed jet of water from the third nozzle to prevent water from entering the local shield, but the workpiece has a complicated shape. In the formed water curtain,
It may not be possible to completely prevent water intrusion. In Japanese Utility Model Application Laid-Open No. 55-116785, the pressing force of the welding machine depends on the force of the operator, and skill is required to prevent water from entering. Also, repair inside the reactor cannot be realized due to the effects of radiation.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and prevents underwater penetration of water into a shield even when machining a complicated shaped member underwater, and has a local shield mechanism capable of performing highly reliable machining. It is intended to provide a device.

[0007]

Means for Solving the Problems The present invention, in water
Workpiece is heated by heat source by laser light or arc
An underwater processing apparatus provided with a torch,
Locally shield the processed part at the end of the workpiece side
At least a double solid partition is provided, and the solid partition is
Inside the shield to prevent water from entering each
The shield gas is supplied to each of the innermost solid partition walls
Is a fiber having heat resistance to heating near the heat source.
Made of woven fabric, deformable to follow the shape of the workpiece
It is characterized by having a flexible structure.

Further, at least one Sosonae outside peripheral portion of the above solid bulkhead underwater processing device of the present invention, further, the bullet the skirt portion of said solid partition wall from the outer periphery of the solid bulkhead on the surface of the workpiece
Characterized in that it comprises a pressing means for pressing using a sex body
You.

Further, at least one Sosonae outside peripheral portion of the above solid bulkhead underwater processing device of the present invention, further, pressing the skirt portion of the front Stories solid partition wall from the outer peripheral portion of the solid bulkhead on the surface of the workpiece further comprising a second nozzle for ejecting a high-speed fluid
It is characterized by.

Further, water processing apparatus of the present invention, the solid <br/> body partition wall mentioned above at least 1 Sosonae outside peripheral portion, further, the skirt portion of the front Stories solid partition wall from the outer peripheral portion of the solid bulkhead Bei <br/> give a second nozzle for ejecting a high-speed fluid for pressing the surface of the workpiece, further, to have pressing means for pressing with a resilient member said solid partition wall to the surface of the workpiece It is characterized by.

Further, the underwater processing apparatus of the present invention is characterized in that
Bei give a double solid partition wall even without further characterized as having a pressing means for pressing the outer peripheral portion by using an elastic member on the surface of the workpiece of the solid bulkhead solid partition wall skirt portion of.

[0012] In the underwater processing apparatus having the above-described structure, it is preferable that the first nozzle and the solid partition have a mechanism capable of independently moving.

In the underwater processing apparatus, it is preferable that the high-speed fluid is any of air, inert gas, and water.

In the underwater processing apparatus, the flexible solid partition wall is formed by processing a cloth made of at least one fiber selected from the group consisting of carbon fiber, silicon wool, glass fiber, and ceramic fiber. It is preferred that it consists of

In the underwater processing apparatus, a sensor for sensing an atmosphere is provided in the first nozzle, and a pressing force for pressing a skirt portion of the solid partition wall to the surface of the workpiece by a signal from the sensor. Is preferably provided.

In the underwater processing apparatus, the processing machine may be an arc welding machine.

Further, in the underwater processing apparatus, the processing machine may be a laser processing machine.

[0018]

According to the first aspect of the present invention, there is provided a high-speed airflow discharge nozzle for ejecting a high-speed airflow to locally remove water, and a flexible member having an outer peripheral portion having a shape capable of maintaining airtightness in the nozzle. An underwater processing apparatus comprising at least two or more layers of solid partition walls having the following. In conventional underwater processing equipment, the solid partition for shielding water is one layer, but in this case, when large bubbles are released from inside the shield, the pressure cannot maintain the airtightness inside the shield,
Water could enter. By providing two or more solid partition walls, the space between the partition walls can be kept airtight because water intrusion is prevented. The solid partition has, for example, a structure in which cylindrical and trapezoidal shapes are concentrically superimposed, and the number of superposed solid partitions is expressed as one layer or two layers. To improve the airtightness, a certain space is required between the solid partition walls. Even if this space is too large, the effect of maintaining airtightness is reduced. It is desirable that the space volume is equal to or smaller than the volume of the nozzle internal space.

A second aspect of the present invention is a first nozzle for ejecting a high-speed airflow to locally remove water, and the first nozzle,
A flexible solid partition having a shape capable of maintaining airtightness in the nozzle is provided on an outer peripheral portion of the first nozzle, and a skirt portion of the solid partition is processed from an outer peripheral portion of the solid partition. This is an underwater processing apparatus provided with a mechanism for pressing against the surface of an object.

The feature of the present invention is that the solid partition having flexibility is deformed in accordance with the fine irregularities of the workpiece, and the airtightness in the first nozzle is maintained. By pressing the solid partition walls from the outer periphery in accordance with the surface shape of the workpiece, the adhesion of the solid partition walls to the workpiece surface is improved, and the airtightness is further improved. By varying the pressing force from the outer peripheral portion of the solid partition wall according to the depth of the underwater processing device and the direction of the welding device with respect to the depth direction, the airtightness in the first nozzle can be appropriately adjusted to be the best. . This is because, when a second nozzle is provided on the outer periphery of the solid partition wall as the pressing force from the outer periphery of the solid partition wall, the pressing force can be more finely adjusted by adjusting the flow rate of the high-speed fluid from the second nozzle. It will be adjustable. By providing a humidity sensor in the first nozzle and performing feedback control of the pressing force of the solid partition using a computer so that the humidity becomes lowest, airtightness can be further improved.

In the prior art, there has been known a method of pressing a solid partition against a surface of a workpiece by a spring, hydraulic pressure, or water pressure. However, in this method, the solid partition is in contact with an end of the partition (in contact with the workpiece). From the side opposite to the side). In this method, there is a possibility that the airtightness between the solid partition and the surface contact portion of the workpiece is not sufficient. In particular, when the constituent material of the solid partition wall has good flexibility, the tendency was strong. To solve this problem, the present inventors improve the airtightness in the first nozzle by applying a pressing force from the outer peripheral portion of the skirt portion of the solid partition (near the contact portion between the solid partition and the surface of the workpiece). The present invention has been found to be possible. As the pressing force from the outer periphery of the solid partition, an elastic body such as a spring or rubber may be used, or a second nozzle may be provided on the outer periphery of the solid partition to provide a second nozzle.
A high-speed fluid may flow from the outside of the solid partition wall along the solid partition wall from the nozzle, and may be pressed by the pressure of the fluid. Further, the elastic body and the high-speed fluid from the second nozzle may be used together. By changing the pressing force of these solid partition walls, the airtightness in the first nozzle can be adjusted to be the best in accordance with the water depth of the underwater processing device and the orientation of the welding device with respect to the water depth direction.

In this case, the key to improving airtightness is
This is the shape of the solid partition. If the solid partition is made of a flexible material and is not formed in a flared shape, the skirt of the solid partition cannot be pressed against the surface of the workpiece as described above. Further, the amount of high-speed fluid jetted can be reduced by using not only the high-speed fluid jet from the second nozzle but also the pressing by an elastic body such as a spring or rubber on the solid partition wall. The design of the tube for transferring the fluid is facilitated.

Further, since the first nozzle and the solid partition wall are provided with a mechanism that moves independently, processing in water and shielding of water are facilitated, and high-quality water processing can be performed.
For example, when performing welding or surface treatment in water by TIG (Tungsten Inert Gas) welding method, when starting welding,
In order to generate an arc, it is necessary to bring the tip of the electrode into contact with the surface of the workpiece and return to the original position again at the same time as the generation of the arc. Here, since the nozzle for the first water shield integrated with the electrode moves alone with the solid partition, the solid partition is in contact with the surface of the workpiece, Only the nozzle can be moved up and down. Therefore, infiltration of water from the solid wall into the processed portion is prevented, and stable welding can be performed.

The high-speed fluid ejected from the second nozzle may be any one of air, inert gas and water. In the case of performing underwater processing, when a high-speed water flow is used, a more efficient pressing force can be obtained compared to air and an inert gas, but equipment for generating a high-speed water flow is required. When air and inert gas are used, it is only necessary to supply gas from the high-pressure gas cylinder to the second nozzle through a decompressor, so that the equipment is simplified as compared with the case where high-speed water flow is used. Whether air, inert gas, or water is used as the high-speed fluid is appropriately selected according to cost and other requirements.

The material of the solid partition wall is desirably composed of carbon fiber, silicon wool, glass fiber, ceramic fiber alone or in combination. As the material of the solid partition wall, when the processing is welding, heat resistance is required because high-temperature spatter is scattered. In addition, flexibility is required in order to maintain a high degree of airtightness by deforming in accordance with the unevenness of the surface of the workpiece. The above materials are selected as materials satisfying those requirements. Carbon fibers have the advantage that they are excellent in flexibility and inexpensive compared to other materials, but they are not very excellent in oxidation resistance. Ceramic fiber has excellent oxidation resistance, but its price is higher than carbon fiber.
Flexibility is also inferior to carbon fibers. Silicon wool and glass fiber have intermediate properties between them, and the material is appropriately selected according to the required characteristics of the underwater processing machine. As the solid partition wall, those obtained by weaving these fibers in a cloth shape and appropriately processing them are used. Processing refers to cutting into strips, stacking a plurality of them into a conical skirt, and the like. The thickness of the cloth is preferably 0.5 mm or more, but if it is too thick, the flexibility is inferior.

When the second nozzle is used, the second nozzle
It is desirable that the flow rate of the high-speed fluid of the first nozzle is adjusted so that the airtightness in the first nozzle is best. This adjustment always monitors the airtightness in the first nozzle, and when water infiltrates, increases the flow rate of the high-speed fluid and improves the adhesion of the solid partition to the workpiece. It is desirable. Further, if the flow rate of the high-speed fluid is increased, the airtightness is improved, but an excessive flow rate is uneconomical, so it is desirable to flow an appropriate flow rate. For this reason, it is desirable to provide a humidity sensor, a temperature sensor, an oxygen sensor, and the like in the first nozzle, and to provide a mechanism for changing the flow rate of the high-speed fluid in accordance with information from these sensors. It is most desirable to perform this adjustment in real time using a high-speed arithmetic system using a microcomputer.

When an arc welding machine is used as the underwater processing device, it can be applied to repair of cracks in a workpiece.

When a laser processing machine is used as the underwater processing apparatus, fine processing can be performed, and the present invention can be applied to surface treatment.

The first nozzle of the above-described underwater processing apparatus is also provided with a processing nozzle. That is, a processing nozzle is provided inside the first water shield nozzle for removing water, and this is integrated. In addition, the gas discharged from the first nozzle for removing water also has a shielding effect for protecting the processed portion from the outside air. The processing nozzle is the tip of the torch for welding, surface treatment, cutting, and the like. For example, a tungsten electrode for TIG welding, a processing lens or mirror mechanism at the tip of a laser heat source, a nozzle for thermal spraying, and the like.

[0030]

【Example】

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention. A water shielding nozzle 1 for locally removing water and a solid partition wall 4 for shielding water on the outer periphery thereof are provided, which can be moved independently. A second nozzle that has a mechanism for pressing against the surface of the solid partition wall and that eliminates and blocks water around the solid partition wall 4, that is, a solid partition pressurizing nozzle 1 for pressurizing the solid partition wall.
0 is a processing device. The skirt 11 of the solid partition wall 4 is constantly pressed against the surface of the workpiece by compressed air, compressed gas, or jet water (all described as 12), and is stably in contact with the surface of the workpiece. For this reason, water can be stably eliminated while moving according to the surface shape of the processed member. Therefore, even a workpiece having a complicated shape can be stably welded in water. The solid partition is made of carbon fiber and has a thickness of 0.5m
It is made by molding 10 pieces of m 2 cloth in a lap shape. Ar gas was used as the shielding gas.

(Embodiment 2) An embodiment in which the present invention is applied to surface modification in which the surface of a member of a nuclear reactor apparatus is heated by a laser heat source will be specifically described. FIG. 2 shows the structure of the laser beam 13 used in the present embodiment, the lens 14 for processing the laser beam 13, and the nozzle 1 for water shielding. As shown in FIG. 2, inside the first water shielding nozzle 1 for removing water, a laser processing lens 14 for surface modification is arranged, and these are integrated. In this case, the shielding gas for protecting the processing portion from the outside air is sucked by the gas suction pipe 15 for processing.

A solid partition 4 for shielding water is provided outside the water shield nozzle 1. The solid partition wall 4 includes a pressing spring 5 and a skirt pressing spring 16 of the solid partition wall.
A mechanism is provided to be pressed against the surface-modified member surface 17. Here, the first water shield nozzle 1 and the solid partition wall 4 are configured to move independently in the axial direction of the water shield nozzle. This facilitates processing in water and shielding of water as described below, and enables high-quality surface modification in water.

For example, when performing surface modification or heat treatment in water using a laser heat source, it is important to keep the focal length of the light beam with respect to the surface 17 of the surface-modified member and the nozzle height constant. This apparatus is provided with an apparatus capable of controlling the focal length of the light beam with respect to the surface-modified member surface 17 and the nozzle height to be constant. Here, the first water shield nozzle 1 integrated with the processing lens 14 moves independently of the solid partition wall 4. For this reason, even if the first nozzle for water shield moves up and down, the solid partition wall 4
Only the water shield nozzle 1 can move up and down in a state of contacting the surface-modified member surface 17. Therefore, infiltration of water into the processed portion is prevented by the solid partition wall 4, and stable welding can be performed.

In this embodiment, solid partition walls made of carbon fiber were used, and He gas 18 was used as a shielding gas.

On the other hand, the distance from the base material surface can be arbitrarily adjusted by moving both. Therefore, even when the groove shape and the welding posture are changed, the solid partition wall 4 can be sufficiently and stably contacted with the surface of the surface-modified member, so that stable surface modification can be performed under water, and the reliability can be improved. A high surface modified contact is obtained.

(Embodiment 3) FIG. 3 shows an example in which the underwater welding apparatus of the present invention is applied to a shroud 82 in a pressure vessel of a nuclear power plant. A large amount of radiation is emitted from the internal structure of a nuclear power plant. For this reason, repair welding must be performed by remote automatic control in consideration of worker safety. Therefore, the underwater welding apparatus is provided with a welding power source 85 installed in the atmosphere (outside the pressure vessel or a place where there is no influence of water).
More electric power is supplied, an arbitrary welding condition is given by the control device 86, and an arc is emitted from a welding torch 89 in a water shield nozzle 88 installed underwater through a cable 87 to perform welding.

FIG. 4 shows a detailed structure of the water shield nozzle 88 used in this embodiment.

As shown in FIG. 4, a water shield nozzle 1 for removing water from inside the shield and a tungsten electrode 2 for TIG welding are disposed inside a water shield nozzle 88 for removing water. It is integrated with the water shield nozzle 1. In addition, in order to discharge the water in the shield from the water shield nozzle 1, a gas 3 of a high-speed air current is jetted. The high-speed airflow gas 3 also has a shielding effect for protecting the processing portion from outside air.

On the other hand, outside the water-shielding nozzle 1, two solid partitions 4 and 4a for shielding water are arranged. Here, the water-shielding nozzle 1 and the solid partition wall 4a have a structure in which they are independently moved by a pressure spring 5 in the axial direction of the water-shielding nozzle 1. This facilitates underwater processing and shielding of water as described below, and enables high-quality underwater processing.

For example, when performing welding or surface treatment in water by the TIG welding method, at the start of welding, the tip of the tungsten electrode 2 is brought into contact with the workpiece surface 6 to generate an arc 7 at the start of welding. At the same time, it is necessary to return to the original position again. Here, the water shield nozzle 1 integrated with the tungsten electrode 2 moves independently with the solid partition wall 4a. For this reason, even when the water shield nozzle 1 moves up and down, the solid partition walls 4 and 4a
Only the water shield nozzle 1 can move up and down while in contact with the workpiece surface 6. Therefore, infiltration of water into the processed part is prevented by the solid partition wall 4a, and stable welding can be performed. Further, even when the groove shape and the welding posture are changed, the solid partition walls 4 and 4a can be sufficiently and stably brought into contact with the surface 6 of the workpiece, so that stable welding can be performed underwater and high reliability can be obtained. A weld is obtained.

The solid partition is preferably made of a material having high elasticity and flexibility. In the present embodiment, a felt-like glass cloth having both surfaces coated with silicone rubber was used. Here, the solid partition wall 4a was made of a felt-like material having a thickness of 0.5 mm and made of the above-mentioned material in a conical skirt shape. The solid partition wall 4a was manufactured by cutting the felt into a strip having a width of 3 to 5 mm, and stacking 2 to 10 of them to form a conical skirt. Thereby, the whole nozzle becomes flexible, and the spring action works effectively.

In this embodiment, Ar gas was used as the shielding gas 3. The flow rate in this case is 30 l / min.

The above embodiment is not limited to TIG welding.
It can also be applied to IG welding, laser welding, laser surface modification, laser cutting, and the like. This embodiment enables underwater welding in a nuclear reactor.

(Embodiment 4) The embodiment shown in FIG. 5 shows a structure of a water shield nozzle capable of always shielding water in a stable state even with a workpiece having a more complicated shape. The structure has a water shielding nozzle 1 for locally removing water and solid partition walls 4 and 4a for shielding water on the outer periphery thereof. Here, the water shield nozzle 1 and the solid partition walls 4 and 4a are characterized in that they can be independently moved by a pressure spring 5. Thereby, as described in the third embodiment, the processing in the water and the shielding of the water are facilitated, and the processing in the high-quality water can be performed. Further, the outer solid partition wall 4a has a mechanism that is pressed against the surface of the workpiece surface 6 by the pressure spring 5a. As a result, the solid partition wall 4a constantly and stably contacts the workpiece surface 6,
Water can be prevented from entering the shield.

The solid partition used in this embodiment is the same as that in the fourth embodiment.

In this embodiment, Ar gas is used as the shielding gas 3. The flow rate in this case is 50 l / min. This gas also has a shielding effect for protecting the processing portion from the outside air.

The above embodiment is not limited to TIG welding,
It can also be applied to IG welding, laser welding, laser surface modification, laser cutting, and the like. According to the present embodiment, underwater welding in a nuclear reactor has become possible.

[0048]

According to the present invention, an atmosphere suitable for processing can be stably maintained even in high-pressure water. Therefore, highly reliable processing can be performed even when the processing posture or the processing shape changes. For this reason, even if this processing apparatus is applied to the in-core equipment of a nuclear power plant, welding, cutting, heat treatment, etc. of a ship, a processed part with high reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an underwater TIG welding device for local shield using an elastic body and a second nozzle in combination.

FIG. 2 is a schematic diagram showing an underwater laser beam machine for local shielding in which the bottom of a solid partition is pressed by an elastic body.

FIG. 3 is a diagram showing an example in which the underwater processing apparatus of the present invention is applied to repair processing of a pressure vessel of a nuclear power plant.

FIG. 4 is a schematic view showing an underwater laser beam machine for local shield provided with two layers of solid partition walls.

FIG. 5 is a schematic diagram showing an underwater laser beam machine for local shielding in which two layers of solid partitions are provided, and the bottom of the outer solid partitions is pressed by an elastic body.

[Explanation of symbols]

1 ... Nozzle for water shield, 2 ... Tungsten electrode, 3 ...
Shielding gas, 4 ... Solid partition, 5 ... Pressure spring, 6 ... Workpiece surface, 7 ... Arc, 8 ... Solid partition pressure adjustment guide, 9 ... Solid partition mounting member, 10 ... Solid partition press nozzle, 11: Bottom of solid partition wall, 12: Compressed air or compressed gas or jet water, 13: Laser beam, 14: Processing lens, 15: Gas suction pipe, 16: Bottom pressure spring of solid partition wall, 17: Surface modification Material member surface, 18 ... He gas, 82
... shroud in the pressure vessel of the nuclear power plant, 85 ... welding power source of underwater welding equipment installed in the atmosphere (outside the pressure vessel or a place where there is no influence of water), 86 ... control device, 87
... Cable, 88 ... Water shield nozzle installed in water, 89 ... Welding torch.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI B23K 26/12 B23K 26/12 26/14 26/14 Z 37/00 37/00 A (56) References JP-A-57-57- 64476 (JP, A) JP-A-63-49370 (JP, A) JP-A-49-95839 (JP, A) JP-A-57-199574 (JP, A) JP-A-1-151979 (JP, U) 56-116785 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/00 B23K 9/013 B23K 26/12 B23K 26/14 B23K 37/00

Claims (5)

(57) [Claims] 1. An underwater processing apparatus provided with a torch for heating a workpiece in a water by a heat source using a laser beam or an arc, wherein at least a double-layered part is locally shielded at a tip of the torch on the workpiece side. Of the shield, a shielding gas is supplied to each of the shields so that water does not infiltrate into each of the shields, and the innermost solid partition is heated against heat near the heat source. An underwater processing apparatus comprising a heat-resistant fiber woven fabric and having a flexible structure that can be deformed following the shape of the workpiece. 2. An underwater processing apparatus provided with a torch for heating a workpiece in a water by a heat source using a laser beam or an arc, wherein a solid partition wall for locally shielding a processing portion is provided at an end of the torch on the workpiece side. The solid partition wall is made of a woven fabric of fibers that is supplied with a shielding gas into the shield so as to prevent water from entering the shield, and that has heat resistance to heating near the heat source. Pressurizing means for pressing the bottom of the solid partition from the outer periphery of the solid partition to the surface of the workpiece using an elastic body. An underwater processing apparatus, comprising: 3. An underwater processing apparatus provided with a torch for heating a workpiece in a water by a heat source using a laser beam or an arc, wherein a solid partition wall for locally shielding a processing portion is provided at an end of the torch on the workpiece side. The solid partition wall is made of a woven fabric of fibers that is supplied with a shielding gas into the shield so as to prevent water from entering the shield, and that has heat resistance to heating near the heat source. A flexible structure that can be deformed following the shape of the solid partition wall, and further ejects a high-speed fluid that presses the bottom of the solid partition wall from the outer peripheral portion of the solid partition wall to the surface of the workpiece. An underwater processing apparatus comprising a nozzle. 4. An underwater processing apparatus provided with a torch for heating a workpiece in a water by a heat source using a laser beam or an arc, wherein a solid partition wall for locally shielding a processing portion is provided at an end of the torch on the workpiece side. The solid partition wall is made of a woven fabric of fibers that is supplied with a shielding gas into the shield so as to prevent water from entering the shield, and that has heat resistance to heating near the heat source. A flexible structure that can be deformed following the shape of the solid partition wall, and further ejects a high-speed fluid that presses the bottom of the solid partition wall from the outer peripheral portion of the solid partition wall to the surface of the workpiece. An underwater processing apparatus comprising: a nozzle; and pressing means for pressing a skirt portion of the solid partition from an outer peripheral portion of the solid partition to a surface of a workpiece using an elastic body. 5. An underwater processing apparatus provided with a torch for heating a workpiece in a water by a heat source using a laser beam or an arc, wherein at least a double-layer part of which is locally shielded at a tip of the torch on the workpiece side. Of the shield, a shielding gas is supplied to each of the shields so that water does not infiltrate into each of the shields, and the innermost solid partition is heated against heat near the heat source. It is made of a heat-resistant fiber woven fabric, has a flexible structure that can be deformed following the shape of the workpiece, and furthermore, the skirt of the solid partition is processed from the outer periphery of the solid partition. An underwater processing apparatus, comprising: pressing means for pressing an object using an elastic body.