Underwater non-gas tungsten arc welding apparatus and method

Abstract

The application discloses a kind of underwater non-melting electrode inert gas shield welding device and method thereof, underwater non-melting electrode inert gas shield welding device includes water shield, welding torch, motor;Water shield includes opposite gas path interface end and open end;Welding torch is with its gun head towards open end and tight fit in water shield, in water shield isolation one between welding torch and gas path interface end Water area, one between welding torch and open end drainage area;Motor is set in water area and with its output shaft and eccentric shaft transmission connection of welding torch;Welding torch is provided with the inner gas path that is penetrated to its gun head, gas path interface end and water area, inner gas path and drainage area are sequentially communicated, for accessing inert gas and making it full drainage area.A local dry state environment is provided in drainage area, to ensure that welding torch arc stability and arc stability during welding process.Eccentricity of eccentric shaft can be adjusted to form annular continuous weld or arc weld with different curvature radius.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nuclear power plant maintenance, in particular to an underwater non-consumable electrode inert gas shielded welding device and method. BACKGROUND

[0002] Due to the influence of radiation, the replacement of the main equipment of the nuclear power plant in service needs to be carried out in water to shield most of the radiation, which includes underwater welding. The main problem of underwater welding in the pool of the nuclear power plant is how to realize automatic welding and obtain clean, smooth and reliable weld. The current main research direction of underwater welding is shielded arc welding and flux-cored wire gas shielded welding, but these two welding methods have large welding smoke, low underwater visibility and poor welding quality.

[0003] Tungsten inert gas (TIG) welding has the advantages of beautiful weld formation, high welding quality and small welding smoke, and is especially suitable for the construction and repair of underwater equipment of nuclear power plants. For underwater non-consumable electrode inert gas shielded welding, wet welding cannot guarantee the stability of the arc during welding, and dry welding needs to use an additional drainage gas chamber, which has great limitations. SUMMARY

[0004] The technical problem to be solved by the present application is to provide an improved underwater non-consumable electrode inert gas shielded welding device and method.

[0005] The technical solution adopted by the present application to solve the technical problem is to provide an underwater non-consumable electrode inert gas shielded welding device, which comprises a water barrier cover, a welding gun and a motor.

[0006] The water barrier cover comprises opposite gas path interface ends and an open end; the welding gun is tightly fitted in the water barrier cover with its gun head facing the open end of the water barrier cover, and a water barrier area between the welding gun and the gas path interface end of the water barrier cover and a drainage area between the welding gun and the open end of the water barrier cover are isolated in the water barrier cover.

[0007] The motor is arranged in the water barrier area and is in transmission connection with the eccentric shaft of the welding gun through its output shaft;

[0008] The welding gun is provided with an internal gas path penetrating to the gun head, the gas path interface end of the water barrier cover is in communication with the water barrier area, the internal gas path and the drainage area in sequence, and is used for connecting inert gas and making the inert gas fill the drainage area.

[0009] Preferably, the welding gun comprises the gun head, the eccentric shaft and a support seat.

[0010] The outer circumferential surface of the support seat is sealingly matched with the inner circumferential surface of the water-proof cover;

[0011] The eccentric shaft comprises an input end and an eccentric end parallel to the input end and different in axis;

[0012] The input end of the eccentric shaft is arranged in the support seat and coaxially connected with the output shaft of the motor, the eccentric end of the eccentric shaft is located in the drainage area, and the gun head is arranged at the eccentric end of the eccentric shaft.

[0013] Preferably, the eccentric shaft is a hollow shaft, the side of the support seat towards the water-proof area is provided with an air inlet hole, the air inlet hole is sequentially communicated with the inner cavity of the eccentric shaft, the gun head and the drainage area, and forms the inner gas path.

[0014] Preferably, a gas outlet hole is arranged on a surface of the eccentric shaft and communicated with the drainage area;

[0015] The air inlet hole of the support seat is sequentially communicated with the assembly gap, the drainage area, and forms the outer gas path for the circulation of the inert gas.

[0016] Preferably, an assembly gap is formed between the eccentric shaft and the support seat;

[0017] The air inlet hole of the support seat is sequentially communicated with the assembly gap and the drainage area, and forms the outer gas path for the circulation of the inert gas.

[0018] Preferably, a sealing connecting piece is arranged between the support seat and the inner circumferential surface of the water-proof cover.

[0019] Preferably, the gun head comprises a tungsten electrode arranged in the eccentric end of the eccentric shaft and a nozzle connected to the eccentric end of the eccentric shaft and located at the periphery of the tungsten electrode.

[0020] When the opening end of the water-proof cover is in a cylindrical shape, one end of the tungsten electrode close to the opening end of the water-proof cover is flush with the opening end of the water-proof cover.

[0021] Preferably, the shape of the opening end of the water-proof cover is arranged corresponding to the target welding surface.

[0022] Preferably, the water-proof cover comprises a first cover body and a second cover body axially connected, the first cover body and the second cover body are detachably connected, one end of the first cover body is the gas path interface end, one end of the second cover body is the opening end, and the eccentric shaft of the welding gun is arranged in the second cover body.

[0023] Preferably, the motor is a hollow cup brush motor.

[0024] Preferably, the water-proof housing gas path interface end is provided with an electrical interface for passing through an electrical cable.

[0025] The application also provides an underwater non-consumable electrode inert gas shield welding method, which adopts the underwater non-consumable electrode inert gas shield welding device described in any one of the above, and comprises the following steps:

[0026] S1, transporting the underwater non-consumable electrode inert gas shield welding device to underwater;

[0027] S2, continuously filling inert gas into the water-proof housing gas path interface end, and moving the open end of the water-proof housing along the side close to the target welding surface;

[0028] S3, adhering the open end of the water-proof housing to the target welding surface, and forming a local dry space for welding operation between the water-proof housing drainage area and the target welding surface;

[0029] S4, starting the motor, and rotating the welding gun around the output shaft of the motor under the driving of the motor;

[0030] S5, starting the welding gun to form an annular weld or an arc-shaped weld on the target welding surface, and completing the welding of the target welding surface.

[0031] Preferably, in step S1, the underwater non-consumable electrode inert gas shield welding device is transported to underwater by using a transportation platform.

[0032] In steps S2-S3, the open end of the water-proof housing is moved along the side close to the target welding surface and adhered to the target welding surface under the cooperation of the visual positioning system.

[0033] The application has at least the following beneficial effects: (1) continuously filling inert gas into the water-proof housing gas path interface end in underwater environment, providing a local dry environment for the welding work of the welding gun, and ensuring the arc starting stability and arc stability during the welding process; (2) compared with the dry welding method which needs to build an additional drainage gas chamber, the welding gun of the device can be directly used in underwater environment to perform welding work on the surface of various underwater equipment, and has high working efficiency and strong flexibility; (3) using the non-consumable electrode inert gas shield welding method, the tungsten electrode of the gun head does not melt during the welding process, and a clean, smooth and reliable weld can be generated, which can meet the quality standard of the construction and repair work of the nuclear power plant underwater project; (4) by controlling the output torque and speed of the motor, automatic annular continuous weld or arc-shaped weld can be realized. By replacing the eccentric shafts with different eccentric distances, annular continuous welds with different radii or arc-shaped welds with different curvature radii can be formed. BRIEF DESCRIPTION OF DRAWINGS

[0034] The present application will be further described in conjunction with the accompanying drawings and embodiments, in which:

[0035] Figure 1 is a structural schematic diagram of an underwater non-consumable electrode inert gas shielded welding device according to an embodiment of the present application;

[0036] Figure 2 is a structural schematic diagram of an underwater non-consumable electrode inert gas shielded welding device according to another embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0038] The terms "first", "second", and the like are only used for the purpose of convenient description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features.

[0039] Figure 1 An underwater non-consumable electrode inert gas shielded welding device according to an embodiment of the present application is shown, which comprises a water-proof cover 1, a welding torch 2, and a motor 3.

[0040] The water-proof cover 1 comprises opposite gas passage interface ends and an open end; the welding torch 2 is fitted into the water-proof cover 1 with its torch head 21 facing the open end of the water-proof cover 1, and a water-proof area 10 between the welding torch 2 and the gas passage interface end of the water-proof cover 1 and a drainage area 11 between the welding torch 2 and the open end of the water-proof cover 1 are isolated in the water-proof cover 1.

[0041] The motor 3 is arranged in the water-proof area 10 and has its output shaft 30 drivingly connected with an eccentric shaft 22 of the welding torch 2. Specifically, the torch head 21 of the welding torch 2 is located in the drainage area 11 and rotates under the drive of the motor 3, and its movement track is a circle with the eccentric distance of the eccentric shaft 22 of the welding torch 2 as the radius.

[0042] The welding torch 2 is provided with an inner gas passage penetrating to its torch head 21, and the gas passage interface end of the water-proof cover 1 is in sequence communicated with the water-proof area 10, the inner gas passage, and the drainage area 11, for connecting the inert gas and making the inert gas fill the drainage area 11.

[0043] Specifically, in the underwater environment, the inert gas is continuously filled into the gas passage interface end of the water-proof cover 1, which provides a protective gas environment for welding while preventing water from entering the drainage area 11, and provides a local dry environment for the welding work of the welding torch 2, thereby ensuring the stable arc starting and arc stability during welding under water.

[0044] Meanwhile, compared with the dry welding method, the welding torch 2 can be directly put into water, and the device is suitable for welding on the surface of equipment in various underwater environments, and has high working efficiency and strong flexibility.

[0045] The non-melting electrode inert gas protection welding method is adopted, the tungsten electrode 210 of the torch head 21 is not melted during the welding process, and a clean, smooth and reliable quality welding seam can be generated, which can meet the construction and repair work quality standards of the underwater engineering of the nuclear power plant.

[0046] By controlling the output torque and speed of the motor 3, the automatic welding of the annular continuous weld or the arc-shaped weld can be realized. By replacing the eccentric shaft 22 with different eccentric distances, the annular continuous weld with different radii or the arc-shaped weld with different curvature radii can be formed.

[0047] In the embodiment, the welding torch 2 includes a torch head 21, an eccentric shaft 22, and a support seat 23;

[0048] The outer peripheral surface of the support seat 23 is sealingly matched with the inner peripheral surface of the water dome 1.

[0049] The eccentric shaft 22 includes an input end 220 and an eccentric end 221 which is parallel to the input end 220 and is different in axis.

[0050] The input end 220 of the eccentric shaft 22 is arranged in the support seat 23 and is coaxially connected with the output shaft 30 of the motor 3, the eccentric end 221 of the eccentric shaft 22 is located in the drainage area 11, and the torch head 21 is arranged at the eccentric end 221 of the eccentric shaft 22.

[0051] Further, as shown in FIG. 1, Figure 2 In other embodiments, the outer peripheral surface of the water dome 1 is relatively penetrated to form a hole position 14 for penetrating a positioning pin (not shown) in the radial direction of the water dome 1, so as to strengthen the tight fit between the support seat 23 and the water dome 1.

[0052] Specifically, the motor 3 is flange-connected and fixed with the support seat 23, and the output shaft 30 of the motor 3 penetrates into the support seat 23. The input end 220 of the eccentric shaft 22 and the output shaft 30 of the motor 3 are connected in the support seat 23, and the center axes of the output shaft 30 of the motor 3 and the input end 220 of the eccentric shaft 22 are located on the same straight line as the center axis of the water dome 1.

[0053] Further, the eccentric shaft 22 is a hollow shaft, the support seat 23 is provided with an air inlet hole 230 on the side facing the water area 10, and the air inlet hole 230 sequentially communicates with the inner cavity of the eccentric shaft 22, the torch head 21 and the drainage area 11, forming an inner air path.

[0054] Furthermore, an air outlet 24 communicating with the drainage area 11 is provided on one surface of the eccentric shaft 22. The air inlet 230 of the support 23 is connected in sequence to the inner cavity of the eccentric shaft 22, the air outlet 24, and the drainage area 11, forming an external air passage for the flow of inert gas.

[0055] Specifically, such as Figure 1 As shown, the arrows represent the flow path of the inert gas. The input end 220 of the eccentric shaft 22 passes through the inner part of the support base 23 and has an opening. The inert gas introduced from the gas passage interface end of the waterproof cover 1 enters the air inlet 230 of the support base 23, flows through the opening of the input end 220 of the eccentric shaft 22 and the inner cavity of the eccentric shaft 22 in sequence, and flows out from the nozzle 21 or from the air outlet 24 to the drainage area 11, forming a double-layer protective gas passage. This allows the continuously injected inert gas to pass through the support base 23 in sufficient quantity to reach the drainage area 11, achieving the effect of ventilation and drainage, creating a good local dry environment underwater, so that the electric arc can burn stably underwater.

[0056] In other embodiments, an assembly gap is formed between the eccentric shaft 22 and the support 23. The air inlet 230 of the support 23 is connected to the assembly gap and the drainage area 11 in sequence, forming an external air passage for the flow of inert gas.

[0057] Furthermore, in this embodiment, a sealing connector 25 is provided between the support base 23 and the inner circumferential surface of the water-proof cover 1. In this embodiment, the sealing connector 25 is a sealing ring, which is fitted onto the outer circumferential surface of the support base 23 to fill the gap between the support base 23 and the inner circumferential surface of the water-proof cover 1, ensuring that the inert gas does not leak out from the gap, but flows to the drainage area 11 along the inner and outer gas paths.

[0058] Furthermore, in this embodiment, the gun head 21 includes a tungsten electrode 210 passing through the eccentric end 221 of the eccentric shaft 22, and a nozzle 211 connected to the eccentric end 221 of the eccentric shaft 22 and located around the tungsten electrode 210. As shown in the figure, when the opening end of the water-proof cover 1 is cylindrical, one end of the tungsten electrode 210 near the opening end of the water-proof cover 1 is flush with the opening end of the water-proof cover 1, so as to ensure that when the opening end of the water-proof cover 1 is attached to the target welding surface, the tungsten electrode 210 contacts the area to be welded on the target welding surface.

[0059] In this embodiment, the shape of the opening end of the waterproof cover 1 corresponds to the target welding surface. For example, in some embodiments, the shape of the opening end of the waterproof cover 1 is designed to mimic the shape of the target welding surface of the reactor internals. The opening end of the waterproof cover 1 is stepped, and after fitting properly with the target welding surface of the reactor internals, a good underwater local dry environment can be formed.

[0060] Further, in the embodiment, the water-proof cover 1 comprises axially connected first cover body and second cover body, the first cover body and the second cover body are detachably connected, one end of the first cover body is a gas path interface end, one end of the second cover body is an open end, the eccentric shaft 22 of the welding torch 2 is installed in the second cover body, the second cover body can be detached to conveniently and quickly replace the eccentric shaft 22 with different eccentric distances or replace the torch head 21, different workpieces can be welded to form different welds.

[0061] Further, in the embodiment, considering the underwater radiation influence of the nuclear power station, the common brushless Hall motor should be avoided, and the motor 3 is a hollow cup brush motor. The hollow cup brush motor is small in size, light in weight and fast in response speed, so that the device is light and smart as a whole, and is suitable for the working conditions of overcoming water resistance and underwater positioning when underwater welding is performed.

[0062] Further, in the embodiment, the water-proof cover 1 is provided with an electrical interface 12 for penetrating an electrical cable at the gas path interface end. Specifically, the gas path interface 13 and the electrical interface 12 are located at the gas path interface end of the water-proof cover 1, and a sealing element can be arranged between the gas path interface 13, the electrical interface 12 and the cable (gas pipe or electrical cable connected to inert gas) to seal the cable and the interface.

[0063] The application also provides an underwater non-groove inert gas shield welding method, which adopts the underwater non-groove inert gas shield welding device.

[0064] S1, transporting the underwater non-groove inert gas shield welding device to underwater;

[0065] Further, the underwater non-groove inert gas shield welding device is transported to underwater by using a transportation platform;

[0066] S2, continuously filling inert gas at the gas path interface end of the water-proof cover 1, and moving the open end of the water-proof cover 1 along the side close to the target welding surface;

[0067] S3, adhering the open end of the water-proof cover 1 to the target welding surface, forming a local dry space for welding operation between the water drainage area 11 of the water-proof cover 1 and the target welding surface, and aligning the tungsten electrode 210 with the weld contour of the target welding surface;

[0068] Further, in steps S2-S3, the open end of the water-proof cover 1 is moved along the side close to the target welding surface and adhered to the target welding surface under the cooperation of the visual positioning system.

[0069] S4, starting the motor 3, and rotating the welding torch 2 around the output shaft 30 of the motor 3 under the driving of the motor 3;

[0070] S5, the welding torch 2 is started to arc on the target welding surface to form a ring-shaped weld or arc-shaped weld, and the welding of the target welding surface is completed.

[0071] Specifically, in the embodiment, taking the positioning pin end face of a surface of the in-core component as an example, the underwater non-gas shield welding device is transported into the reactor fuel pool of the nuclear power plant under the cooperation of the visual positioning system and the transportation platform, and the open end of the water shield 1 is moved along a surface close to the positioning pin end face of the in-core component.

[0072] The inert gas enters the gun head 21 and the drainage area 11 through the inner and outer gas paths, so that the open end of the water shield 1 and the surface where the positioning pin end face is located are completely attached, and a suitable local dry welding environment is formed between the surface where the positioning pin end face is located and the drainage area 11.

[0073] The motor 3 is turned on, and the tungsten electrode 210 will move according to the pre-designed circumferential trajectory, and the movement speed is related to the current size of the motor 3. At this time, the drainage condition of the surface where the positioning pin end face is located is continuously observed, and the pre-tracking of the weld is corrected, so that the movement trajectory of the tungsten electrode 210 is completely coincided with the weld path, and in addition, the distance from the tungsten electrode 210 to the surface where the positioning pin end face is located is also appropriately controlled.

[0074] Arcing, the arc extinguishing time point is controlled according to the welding speed, and at this time, the repair of a workpiece is completed. After the repair is completed, the underwater non-gas shield welding device is transported to the next positioning pin end face to be repaired under the cooperation of the visual positioning system and the transportation platform, or is transported back to the land.

[0075] The above are only some specific embodiments of the present application, and do not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An underwater non-gas tungsten arc welding device, characterized by, The underwater non-consumable electrode inert gas shielded welding device comprises a water-proof cover, a welding torch and a motor; The water-proof cover comprises opposite gas passage interface ends and an open end; the welding torch is tightly fitted in the water-proof cover with its torch head facing the open end of the water-proof cover, and a water-proof area between the welding torch and the gas passage interface end of the water-proof cover and a drainage area between the welding torch and the open end of the water-proof cover are isolated in the water-proof cover; The motor is arranged in the water-proof area and has its output shaft in transmission connection with the eccentric shaft of the welding torch; The welding torch is provided with an internal gas passage penetrating to its torch head, the gas passage interface end of the water-proof cover is in sequential communication with the water-proof area, the internal gas passage and the drainage area, and is used for connecting the inert gas and making the inert gas fill the drainage area; The welding torch comprises the torch head, the eccentric shaft and a support seat; the eccentric shaft is a hollow shaft, and the side of the support seat facing the water-proof area is provided with an air inlet hole in sequential communication with the internal cavity of the eccentric shaft, the torch head and the drainage area, forming the internal gas passage; The underwater non-consumable electrode inert gas shielded welding device further comprises an external gas passage for the flow of the inert gas, and the external gas passage is optionally any one of the following: (1) a surface of the eccentric shaft is provided with an air outlet hole in communication with the drainage area; the external gas passage comprises the air inlet hole of the support seat, the internal cavity of the eccentric shaft, the air outlet hole and the drainage area in sequential communication; (2) an assembly gap is formed between the eccentric shaft and the support seat; the external gas passage comprises the air inlet hole of the support seat, the assembly gap and the drainage area in sequential communication.

2. The underwater non-gas tungsten arc welding apparatus according to claim 1, characterized by, The outer peripheral surface of the support seat is in sealing connection with the inner peripheral surface of the water-proof cover; the eccentric shaft comprises an input end and an eccentric end parallel to and different from the input end; the input end of the eccentric shaft is arranged in the support seat and is coaxially connected with the output shaft of the motor, and the eccentric end of the eccentric shaft is located in the drainage area, and the torch head is arranged at the eccentric end of the eccentric shaft.

3. The underwater non-gas tungsten arc welding apparatus according to claim 1, characterized by, A sealing connector is arranged between the support seat and the inner peripheral surface of the water-proof cover.

4. The underwater non-gas tungsten arc welding apparatus according to claim 2, characterized by The torch head comprises a tungsten electrode arranged in the eccentric end of the eccentric shaft and a nozzle connected to the eccentric end of the eccentric shaft and located outside the tungsten electrode; When the open end of the water-proof cover is in the shape of a cylinder, one end of the tungsten electrode close to the open end of the water-proof cover is flush with the open end of the water-proof cover.

5. The underwater non-consumable inert gas shielded welding apparatus according to any one of claims 1 to 4, characterized by, The shape of the open end of the water-proof cover is arranged according to the target welding surface.

6. The underwater non-gas tungsten-arc welding apparatus according to any one of claims 1 to 4, characterized by The water-proof cover comprises axially connected first and second cover bodies, the first and second cover bodies are detachably connected, one end of the first cover body is the gas passage interface end, one end of the second cover body is the open end, and the eccentric shaft of the welding torch is arranged in the second cover body.

7. The underwater non-gas tungsten-arc welding apparatus according to any one of claims 1 to 4, characterized by The motor is a hollow cup brush motor.

8. The underwater non-gas tungsten arc welding apparatus according to any one of claims 1 to 4, characterized by The gas passage interface end of the water-proof cover is provided with an electrical interface for penetrating an electrical cable.

9. An underwater non-consumable inert gas shielded welding method characterized by, The underwater non-consumable electrode inert gas shielded welding method comprises the following steps: S1, transporting the underwater non-consumable electrode inert gas shielded welding device to underwater; S2, continuously filling inert gas at the gas path interface end of the water-proof cover, and moving the open end of the water-proof cover along the side close to the target welding surface; S3, attaching the open end of the water-proof cover to the target welding surface, and forming a local dry space for welding operation between the water discharge area of the water-proof cover and the target welding surface; S4, starting the motor, and rotating the welding gun around the output shaft of the motor under the driving of the motor; S5, starting the welding gun to form an annular weld or arc weld on the target welding surface, and completing the welding of the target welding surface.

10. The underwater non-gas tungsten-arc welding method according to claim 9, characterized by, In step S1, the underwater non-consumable electrode inert gas shielded welding device is transported to underwater by using a transportation platform; In steps S2-S3, the open end of the water-proof cover is moved along the side close to the target welding surface under the cooperation of the visual positioning system, and the open end of the water-proof cover is attached to the target welding surface.

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