Underwater laser welding torch

Abstract

The application discloses underwater laser welding torch, including laser head and drain cover, laser head includes sealed shell, laser head body, welding mechanism and pressure balance mechanism, one end of the sealed shell is detachably connected with the drain cover, the laser head body is arranged at one end of the sealed shell away from the drain cover and extends into the sealed shell, the welding mechanism is arranged in the laser head body, and the pressure balance mechanism is used for balancing pressure on both sides of the sealed shell. The underwater laser welding torch can guarantee the sealing property of the torch structure under water through the arrangement of the pressure balance mechanism and the drain cover, the local dry method environment jointly created can realize stable forming under the environment of several meters of water depth, the influence of deep water pressure on the drainage effect and the dry method environment is effectively overcome, the requirements of no water and pure argon protection in the weld area are realized, underwater laser welding can be stably and reliably carried out, the welding pool can be better protected, and the weld forming is good.

Description

Technical Field

[0001] The invention relates to the field of nuclear reactor-related equipment maintenance, and in particular to an underwater laser welding torch. Background Technology

[0002] After a period of operation, nuclear power plant reactor-related equipment may develop abnormalities, such as reactor pressure vessels and nozzles, internal reactor components, core fuel assemblies, spent fuel pools and fuel grids, refueling pools, and core thermocouple conduit joints. When these abnormalities require repair, drainage is often difficult. These devices suffer from defects that seriously threaten the safe operation of the power plant due to nuclear radiation and stress, such as corrosion, cracks, and surface abrasion. Underwater welding methods are needed for repairs such as leak patching, crack beveling, and surface surfacing. Underwater laser welding is suitable for repairing equipment damaged by structural fatigue and improper operation in nuclear power plant reactors and related components.

[0003] Traditional underwater laser welding typically involves submersible welders wearing heavy protective suits performing manual arc welding. However, during manual welding, the welders are directly exposed to radiation, and the water temperature inside some containers is very high, making the working environment extremely harsh. A single welding operation usually needs to be controlled within one hour, especially in high-radiation areas where it is generally limited to a few minutes. In addition, personnel on the surface need to constantly monitor the radiation dose received by the submersible welders, resulting in high labor costs. Furthermore, during manual welding, submersible welders may face high risks such as drowning and radiation overdose (due to potential hotspots).

[0004] Due to the risks associated with manual welding, current underwater welding methods generally employ wet welding using tungsten inert gas (TIG) welding and metal inert gas (MIG) welding. However, TIG welding suffers from shallow weld penetration, low deposition efficiency, and requires a large and time-consuming high-pressure gas chamber. MIG welding is unstable in wet welding, and dry welding also necessitates the construction of a high-pressure gas chamber, requiring significant manpower, resources, and capital. Furthermore, the accuracy of positioning and repair is not high, and there is a risk of foreign objects falling into reactor-related containers.

[0005] Wet welding suffers from difficulties in controlling stability and guaranteeing weld quality, while dry welding fails to offer the dexterity of underwater laser welding. Localized dry welding, however, uses gas to artificially remove water from the localized welding area, creating a smaller gas phase zone within which the electric arc burns stably. This reduces the harmful effects of water, resulting in significantly improved weld quality compared to wet welding. Compared to dry welding, it eliminates the need for large, expensive drainage chambers, greatly increasing its applicability. Therefore, the main application prospect of underwater laser welding lies in localized dry welding. However, localized dry welding presents technical challenges in maintaining effective drainage and sealing, as well as creating a suitable localized dry welding environment. Summary of the Invention

[0006] The technical problem to be solved by this invention is that the local dry method cannot form a drainage seal.

[0007] The technical solution adopted by this invention to solve its technical problem is: to construct an underwater laser welding torch, which includes a laser head and a drainage cover, wherein the laser head includes:

[0008] A sealed housing, one end of which is detachably connected to the drainage cover;

[0009] The laser head body is located at the end of the sealed housing away from the drainage cover and extends into the sealed housing;

[0010] The welding mechanism is located inside the laser head body;

[0011] A pressure balancing mechanism is installed inside the laser head body to balance the pressure on both the inside and outside of the sealed housing.

[0012] In some embodiments, one end of the sealing housing is provided with a transmission part connected to the drainage cover, the drainage cover is connected to the sealing housing through the transmission part, and the drainage cover and the sealing housing are coaxially arranged.

[0013] In some embodiments, an optical fiber inlet is provided at the end of the laser head body away from the drainage cover, and the welding mechanism communicates with external devices through the optical fiber inlet.

[0014] In some embodiments, the welding mechanism includes a first protection module, a collimation module, a focusing module, and a second protection module disposed within the laser head body. The first protection module, the collimation module, the focusing module, and the second protection module are sequentially arranged along the axial direction of the laser head body from the direction away from the drainage cover to the direction closer to the drainage cover, and a laser lens is provided between the collimation module and the focusing module.

[0015] In some embodiments, the underwater laser welding torch further includes a positioning mechanism disposed within the laser head body for positioning and supporting the welding mechanism;

[0016] The positioning mechanism includes a positioning seat disposed in the laser head body, the welding mechanism is mounted on the positioning seat, and a sealing element is provided between the laser lens and the positioning seat.

[0017] In some embodiments, the laser head body is further provided with an air inlet, the air inlet is provided with a first filter screen, the first filter screen is used to filter the gas entering through the air inlet, and the laser head body is provided with a second filter screen, the second filter screen is used to filter the air filtered by the first filter screen.

[0018] In some embodiments, the laser head body has a mounting groove at one end near the drainage cover for mounting the pressure balancing mechanism. The mounting groove is located on the side of the transmission part away from the drainage cover. The laser head body has a pressure regulating valve port communicating with the mounting groove. The pressure balancing mechanism includes:

[0019] A valve ball is disposed in the mounting groove and is configured to cooperate with the pressure regulating valve port;

[0020] An elastic element, one end of which is connected to the valve ball, and the other end of which is connected to the transmission part.

[0021] In some embodiments, the drainage cover includes a drainage cover body, a retaining body, and an outer layer;

[0022] The drainage cover body is connected to the sealing shell. The drainage cover body is provided with a connecting part that is connected to the sealing shell. The retaining body is connected to the end of the drainage cover body away from the sealing shell. The outer body is connected to the end of the retaining body away from the drainage cover body.

[0023] In some embodiments, the laser head body has a ventilation cavity communicating with the air inlet, and the drainage cover body has a first cavity communicating with the ventilation cavity. The first cavity is vented with air flowing in through the ventilation cavity, and the cross-sectional diameter of the first cavity gradually decreases from the direction near the connection portion toward the direction of the fixation body.

[0024] The retaining body is provided with a second cavity that communicates with the first cavity, and the cross-sectional diameter of the second cavity gradually increases from the direction near the connecting part toward the retaining body.

[0025] In some embodiments, the retaining body is further provided with a wire feeding channel communicating with the second cavity, the wire feeding channel being used to feed the welding wire into the welding area.

[0026] In some embodiments, the outer layer includes an outer substrate and an air-conducting cavity that is in air communication with the outer substrate. High-pressure air is introduced into the outer substrate, and the air-conducting cavity is used to allow the high-pressure air to flow out of the outer layer uniformly.

[0027] The present invention has the following beneficial effects: The underwater laser welding torch uses a sealed shell as its outer shell, which allows the entire torch to be submerged in water and to operate deep into the seabed. At the same time, the pressure balancing mechanism and the drainage cover ensure the sealing of the torch structure underwater. The combined local dry environment can achieve stable forming at a water depth of several meters, effectively overcoming the influence of deep-water air pressure on drainage effect and dry environment, achieving the requirement of waterless and pure argon protection in the weld zone, ensuring stable and reliable underwater laser welding, better protecting the weld pool, and resulting in good weld formation. In addition, the drainage cover is detachable, and the bottom of the drainage cover can be treated differently according to different research objects, which improves the flexibility of the welding torch. Attached Figure Description

[0028] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings:

[0029] Figure 1 This is a schematic diagram of the overall structure of an underwater laser welding torch in some embodiments of the present invention;

[0030] Figure 2 This is a schematic diagram of the component structure of the drainage cover in some embodiments of the present invention. Detailed Implementation

[0031] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0032] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0033] Please see Figure 1 and Figure 2 This is an underwater laser welding torch in some embodiments of the present invention. It is a miniaturized welding torch for underwater laser welding in nuclear power plants, which is used for the maintenance of nuclear reactor-related equipment. It can cover the repair needs of anti-loosening welds of thermocouple column guides and anti-loosening welds of flange screws, and can also cover the repair requirements of reactor pools. It can continuously and effectively drain and seal and create a local dry welding environment.

[0034] The underwater laser welding torch may include a laser head 1 and a drainage cover 2 detachably connected to the laser head 1. The laser head 1 includes a laser head body 10, a sealing housing 11, a positioning mechanism 12, a welding mechanism 13, and a pressure balancing mechanism 14. The laser head body 10 is located at the end of the sealing housing 11 furthest from the drainage cover 2 and extends into the sealing housing 11. An optical fiber inlet 15 is provided at the end of the laser head body 10 furthest from the drainage cover 2. The welding mechanism 13 is located inside the laser head body 10 and communicates with external equipment through the optical fiber inlet 15. The balancing mechanism 14 is also located inside the laser head body 10 and is used to balance the pressure on the inside and outside of the sealing housing 11.

[0035] One end of the sealed housing 11 is detachably connected to the drainage cover 2, enabling the welding torch to be fully submerged in water. Understandably, the sealed housing 11 acts as the outer shell of the welding torch, sealing all internal components and preventing external water from entering the cavity of the laser head body 10. This allows the welding torch to extend into the seabed for operation, distinguishing it from welding torches where only the drainage cover 2 is submerged. It also overcomes the problem that the submersion depth of a localized dry underwater laser welding torch depends on the height of the drainage cover 2.

[0036] Preferably, both the sealing housing 11 and the drainage cover 2 are cylindrical structures, meaning that the entire laser head 1 and the drainage cover 2 are cylindrical, providing good underwater accessibility, high efficiency, and a wide range of applications, making them particularly suitable for confined underwater environments such as those containing internal components. In other embodiments, the sealing housing 11 may also be rectangular, elliptical, or other shapes. Preferably, the sealing housing 11 is made of stainless steel, which has good strength and rigidity and is corrosion-resistant. In other embodiments, the sealing housing 11 may also be made of aluminum alloy or other metals; no specific limitations are made here.

[0037] The drain cover 2 is located at the lower end of the sealing housing 11 and is detachably connected to the sealing housing 11. The lower end of the sealing housing 11 is provided with a transmission part 111 for connecting the drain cover 2. The transmission part 111 can be a threaded part, so that the drain cover 2 is threadedly connected to the sealing housing 11 through the transmission part 111.

[0038] Of course, in some other embodiments, the drainage cover 2 can also be connected to the sealing housing 11 by fasteners such as screws and bolts. Understandably, the drainage cover 2 and the sealing housing 11 are detachably connected, allowing for different treatments of the bottom of the drainage cover 2 depending on the specific research object, thus improving the flexibility of the welding torch and overcoming the problem of a single welding environment in other laser welding torches. Furthermore, the drainage cover 2, in conjunction with the laser head 1, provides a simulated dry environment for underwater laser welding, thereby improving the quality of underwater welding. Further, since the laser head 1 is relatively precise, existing underwater welding experiments use standard laser heads. Because standard laser heads cannot be submerged in water, only the drainage cover at the lower end of the laser head can be submerged, or the existing laser head must be resealed before being submerged as a whole. In the underwater laser welding torch of this application, due to the sealing housing 11, the laser head 1 can be fully submerged without needing to be sealed.

[0039] Meanwhile, the drainage cover 2 and the sealing shell 11 are coaxially arranged. According to the requirements for defocusing amount in the welding process parameters, since the transmission part 111 is a threaded part, the distance between the drainage cover 2 and the sealing shell 11 can be adjusted by turning the knob. By changing the distance between the drainage cover 2 and the sealing shell 11, the purpose of adjusting the defocusing amount can be achieved. That is, the height of the drainage cover 2 can be adjusted to achieve variable defocusing, which solves the common problem of difficulty in changing the defocusing amount of underwater laser welding torches. At the same time, the design of height-adjustable coaxial gas protection can better protect the weld pool and make the weld bead well formed.

[0040] The welding mechanism 13 includes a first protection module 131, a collimation module 132, a focusing module 133, and a second protection module 134 disposed within the laser head body 10. These modules are arranged sequentially along the axis of the laser head body 10 from the direction away from the drainage cover 2 to the direction closer to it. The first protection module 131 is positioned away from the drainage cover 2, while the second protection module 134 is positioned close to it. Both the first and second protection modules 131 and 134 protect the collimation module 132 and the focusing module 133, and both can be sealing rings. The collimation module 132 reduces the laser divergence angle, which is beneficial for light transmission, while the focusing module 133 obtains a small spot size, making its energy more concentrated. The first protection module 131 and the collimation module 132 can be connected by countersunk screws, and the focusing module 133 and the second protection module 134 can also be connected by countersunk screws.

[0041] Furthermore, the welding mechanism 13 also includes a laser lens 135, which is disposed between the collimation module 132 and the focusing module 133. The laser lens 135 can constrain the laser beam emitted by the laser head body 10, so that the laser beam can accurately irradiate the area where the welding wire and the base material are located, thereby melting the welding wire and the base material.

[0042] In some embodiments, the length of the entire laser head 1 is 200mm to 300mm. In specific applications, the length of the entire laser head 1 can be 200mm, 220mm, 240mm, 260mm, 280mm, or 300mm. In this embodiment, the length of the entire laser head 1 is preferably 250mm. The inner diameter of the entire laser head 1 is 40mm to 60mm. In specific applications, the inner diameter of the entire laser head 1 can be 40mm, 45mm, 50mm, 55mm, or 60mm. In this embodiment, the inner diameter of the entire laser head 1 is preferably 50mm. The outer diameter of the sealing housing 11 is 50mm to 70mm. In specific applications, the outer diameter of the sealing housing 11 can be 50mm, 55mm, 60mm, 65mm, or 70mm. In this embodiment, the outer diameter of the sealing housing 11 is preferably 60mm. If the size of the entire laser head 1 is too large, it will affect underwater precision operation and increase equipment costs.

[0043] Understandably, the design size of the laser head 1 enables the miniaturization of the equipment, which has a significant advantage in terms of equipment cost. It is also versatile and flexible in terms of application range, and can solve the problem of precise repair of nuclear reactor-related equipment, reduce cost investment, and shorten the start-up cycle and maintenance period.

[0044] The underwater laser welding torch may further include a positioning mechanism 12, which is located within the laser head body 10. The positioning mechanism 12 is used to position and support the welding mechanism 13. Specifically, the positioning mechanism 12 includes a positioning seat 121 located within the laser head body 10. The welding mechanism 13 is mounted on the positioning seat 121. The positioning seat 121 may be a cylindrical structure, with the welding mechanism 13 housed within it. A sealing element is provided between the laser lens 135 and the positioning seat 121. The laser lens 135 can be fixed to the positioning seat 121 by a circular piece with a slot. The circular piece has a slot and a thread on its periphery. The circular piece is connected to the positioning seat 121 via this thread, and the laser lens 135 is mounted on the circular piece.

[0045] Preferably, the positioning base 121 is made of brass material, which facilitates heat dissipation of the laser lens 135, and the sealing element can be a sealing ring to prevent water from entering the laser lens 135.

[0046] The laser head body 10 is provided with an air inlet 16, and a first filter 17 is provided on the air inlet 16. The first filter 17 is used to filter the gas entering through the air inlet 16, and a second filter 18 is provided inside the laser head body 10. The second filter 18 is used to filter the air that has been filtered by the first filter 17.

[0047] Understandably, the welding gas required for the welding torch enters through the inlet 16, passes through the first filter 17 and the second filter 18, and then enters the cavity of the welding mechanism 13. This gas can be one of air, argon, or nitrogen, or a combination of different gas ratios. In this embodiment, argon is preferred as it protects the weld pool and the working area. In other embodiments, the air can be any other gas that meets the requirements for welding quality and welding materials; no specific limitation is made here. The introduction of this gas provides inert gas protection for underwater laser wire-filled welding, effectively improving weld formation quality. The use of multiple filters in the welding torch gas path ensures more uniform argon gas flow, creating a more stable local dry environment and providing better protection for the weld pool.

[0048] The pressure balancing mechanism 14 is used to balance the pressure on both sides of the sealing housing 11. Specifically, the laser head body 10 has a mounting groove 19 for mounting the pressure balancing mechanism 14 at one end near the drain cover 2. The mounting groove 19 is located on the side of the transmission part 111 away from the drain cover 2. The laser head body 10 has a pressure regulating valve port 101 communicating with the mounting groove 19. The pressure balancing mechanism 14 includes a valve ball 141 and an elastic element 142. The valve ball 141 is located in the mounting groove 19 and is configured to cooperate with the pressure regulating valve port 101. One end of the elastic element 142 is connected to the valve ball 141, and the other end of the elastic element 142 is connected to the transmission part 111. The elastic element 142 is preferably a compression spring.

[0049] Specifically, when the external water pressure gradually increases, the elastic element 142 extends, causing the valve ball 141 to move towards the direction of closing the pressure regulating valve port 101, thus reducing the opening degree of the pressure regulating valve port 101; when the external water pressure gradually decreases, the elastic element 142 compresses, causing the valve ball 141 to move towards the direction of the transmission part 111, thus increasing the opening degree of the pressure regulating valve port 101. This pressure balancing mechanism 14 achieves the purpose of pressure balance on the inner and outer sides of the sealing shell 11 through the cooperative action of the valve ball 141 and the elastic element 142. Understandably, in order to reduce the impact of underwater high pressure on the welding mechanism 13, a pressure balancing mechanism 14 is set up to maintain the pressure on the inner and outer sides of the sealing shell 11. The pressure balancing mechanism 14 and the local dry environment created by the drainage cover 2 can achieve stable forming in a water depth of several meters, effectively overcoming the influence of deep-water air pressure on drainage effect and dry environment.

[0050] like Figure 2 As shown, the drainage cover 2 includes a drainage cover body 21, a retaining body 22, and an outer layer 23. The drainage cover body 21 has a connecting portion 211 that connects to the sealing housing 11. The retaining body 22 is connected to the end of the drainage cover body 21 away from the connecting portion 211, and the outer layer 23 is connected to the end of the retaining body 22 away from the drainage cover body 21. The connecting portion 211 can be a threaded portion that matches the transmission part 111. The connecting portion 211 can cooperate with the transmission part 111 to adjust the distance between the drainage cover 2 and the sealing housing 11, thereby achieving the purpose of adjusting the defocusing amount. The connecting portion 211 and the sealing housing 11 can also be connected by a plug-in connection.

[0051] The drainage cover body 21 can be of a regular shape to accommodate various welding requirements. Its cross-section can be rectangular, circular, elliptical, or other irregular shapes adapted to the shape of the area to be welded. In this embodiment, the drainage cover body 21 has a circular cross-section and a conical three-dimensional shape. The connecting portion 211 is located at the center of the drainage cover body 21 to improve the reliability and accuracy of the welding process. The drainage cover body 21 can be made of lightweight metal materials such as polytetrafluoroethylene or aluminum for easy installation and disassembly.

[0052] In addition, the retaining body 22 can be welded to the drainage cover body 21, or it can be connected by threads or fasteners. Similarly, the retaining body 22 can also be connected to the outer body 23 by welding, threads or fasteners.

[0053] Furthermore, the laser head body 10 has a ventilation cavity 102 communicating with the air inlet 16, and the drainage cover body 21 has a first cavity 212 communicating with the ventilation cavity 102. The first cavity 212 is filled with air flowing in through the ventilation cavity 102. The air is preferably argon, which can protect the welding pool and the working area.

[0054] The cross-sectional diameter of the first cavity 212 gradually decreases from the direction near the connecting part 211 towards the retaining body 22, that is, the first cavity 212 is conical. Understandably, the air intake method of the drainage hood body 21 has a significant impact on the stability of the airflow inside the hood. When the gas inside the drainage hood body 21 moves in a layered or stream-like manner, it can reduce the disturbance of the airflow to the electric arc and facilitate the downward pressure and exhaust of welding fumes. Because the airflow in the lateral intake is relatively chaotic, and the pressure and velocity distribution of the gas are very uneven, it will have a significant impact on the welding arc during welding, causing arc disturbance.

[0055] Therefore, in this embodiment, the drainage cover body 21 adopts a forward air intake method and the first cavity 212 is set as a conical structure, so that the gas pressure and velocity distribution in the drainage cover body 21 is uniform, reducing the impact on the welding arc during welding. The cross-section change of the first cavity 212, which is wider at the top and narrower at the bottom, according to Bernoulli's equation, the flow velocity is faster and the pressure is lower at the position with a smaller cross-section. Therefore, the gas will flow out at a larger flow velocity than the air intake position, quickly displacing water of a certain depth in the welding area, forming a relatively dry welding environment, and also playing a role in protecting the welding pool and the working area.

[0056] Furthermore, the retaining body 22 is provided with a second cavity 221 that communicates with the first cavity 212. The cross-sectional diameter of the second cavity 221 gradually increases from the direction near the connecting part 211 toward the retaining body 22. That is, the second cavity 221 is funnel-shaped, and this funnel-shaped arrangement can prevent water backflow.

[0057] The stationary body 22 is also provided with a wire feeding channel 222 that communicates with the second cavity 221. The wire feeding channel 222 facilitates the feeding of welding wire into the welding area.

[0058] In conventional single-layer gas-assisted drainage devices, the gas introduced is both drainage gas and protective gas. To create a stable localized drying space, the flow rate of drainage gas is often relatively large. This large flow rate leads to waste of protective gas and increases welding costs. Furthermore, a large flow rate of drainage gas can also affect the flow of the molten pool, negatively impacting weld formation. Therefore, based on the design of the single-layer gas-assisted drainage device, this invention adds an outer layer 23. This outer layer 23 includes an outer substrate 231 and an air-conducting cavity 232 that communicates with the outer substrate 231. High-pressure air is introduced into the outer substrate 231, primarily to create a localized drying space. This high-pressure air can be supplied to the outer substrate 231 by an external air source mechanism via a quick-connect plug. The air-conducting cavity 232 ensures that the high-pressure air flows out of the outer layer 23 evenly. The air guide cavity 232 is located between the fixed body 22 and the outer substrate 231. It may include a first air guide cavity and a second air guide cavity arranged vertically. The second air guide cavity has an exhaust port. The high-pressure air filled into the outer substrate 231 can enter the first air guide cavity or the second air guide cavity, and then flow out from the exhaust port of the second air guide cavity.

[0059] Specifically, the welding shielding gas, such as argon, introduced into the drainage cover body 21 mainly serves to protect the weld pool and working area. The outer substrate 231 and the drainage cover body 21 work together to ensure that the water flow in the entire drainage cover is smooth and stable, reducing the disturbance of the water flow at the drainage outlet, allowing the electric arc to burn stably in it, realizing a stable and reliable welding process, improving the welding quality, and ensuring the stability and safety of the underwater laser welding torch during operation.

[0060] In summary, the beneficial effects of this underwater laser welding torch are as follows:

[0061] 1. The underwater laser welding torch uses a sealed shell 11 as its outer shell, which allows the entire torch to be submerged in water and to operate deep into the seabed. This is different from welding torches where only the drainage cover 2 is submerged in water, and overcomes the problem that the submersion depth of a local dry underwater laser welding torch depends on the height of the drainage cover 2.

[0062] 2. The pressure balancing mechanism 14 ensures the sealing of the welding torch structure underwater, and together with the drainage cover 2, it creates a local dry environment that can achieve stable forming in water depths of several meters. It effectively overcomes the influence of deep-water air pressure on drainage effect and dry environment, and achieves the requirement of waterless and pure argon protection in the weld area. It can ensure that underwater laser welding can be carried out stably and reliably, and can better protect the weld pool, resulting in good weld formation.

[0063] 3. The gas path uses multiple filters to make the incoming argon gas more uniform, creating a more stable local dry environment and providing better protection for the molten pool;

[0064] 4. The underwater laser welding torch is cylindrical in shape, which provides good underwater accessibility, high efficiency, and wide applicability. It is more suitable for narrow underwater environments such as internal components. At the same time, the drainage cover 2 is detachable. The bottom of the drainage cover 2 is treated differently according to the different research objects, which improves the flexibility of the welding torch and overcomes the problem of the limited welding environment of other laser welding torches.

[0065] 5. Designed as a height-adjustable coaxial gas shield, it can better protect the weld pool, resulting in good weld formation, and can also be used to adjust the amount of decoking.

[0066] 6. The underwater laser welding torch is equipped with a pressure balancing mechanism 14. When the external water pressure increases, the opening of the pressure regulating valve port 101 corresponding to the valve ball 141 decreases; when the external water pressure decreases, the opening of the pressure regulating valve port 101 corresponding to the valve ball 141 increases, which can ensure the stability of the welding torch in the underwater working environment.

[0067] 7. Due to its miniaturization, the equipment has a significant advantage in terms of cost and is versatile and flexible in its application. It can solve the problem of precise repair of nuclear reactor-related equipment, reduce cost input, and shorten the start-up cycle and maintenance period.

[0068] 8. The drainage cover 2 adopts a forward air intake method, and the cross-sectional diameter of the first cavity 212 gradually decreases along the direction from the connecting part 211 toward the stationary body 22, so that the gas pressure and velocity distribution in the drainage cover body 21 is uniform, reducing the impact on the welding arc during welding, forming a relatively dry welding environment, and also protecting the weld pool and working area.

[0069] 9. The drainage cover 2 is provided with an outer body 23. High-pressure air is introduced into the outer base 231. The outer base 231 and the drainage cover body 21 cooperate with each other to ensure that the water flow in the entire drainage cover 2 is discharged smoothly and stably. The water flow is stable, reducing the disturbance of the water flow at the drain outlet, allowing the electric arc to burn stably in it, realizing a stable and reliable welding process, improving the welding quality, and ensuring the stability and safety of the underwater laser welding torch during operation.

[0070] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An underwater laser welding torch, characterized in that, Includes a laser head (1) and a drainage cover (2), wherein the laser head (1) includes: A sealing housing (11), one end of which is detachably connected to the drain cover (2); The laser head body (10) is located at the end of the sealed housing (11) away from the drain cover (2) and extends into the sealed housing (11); The welding mechanism (13) is located inside the laser head body (10); A pressure balancing mechanism (14) is provided inside the laser head body (10) to balance the pressure on both sides of the sealed housing (11); One end of the sealed housing (11) is provided with a transmission part (111) that is connected to the drainage cover (2). The laser head body (10) has a mounting groove (19) for mounting the pressure balancing mechanism (14) at one end near the drain cover (2). The mounting groove (19) is located on the side of the transmission part (111) away from the drain cover (2). The laser head body (10) also has a pressure regulating valve port (101) communicating with the mounting groove (19). The pressure balancing mechanism (14) includes a valve ball (141) and an elastic element (142). The valve ball (141) is located in the mounting groove (19) and is configured to cooperate with the pressure regulating valve port (101). One end of the elastic element (142) is connected to the valve ball (141), and the other end of the elastic element (142) is connected to the transmission part (111). The drainage cover (2) includes a drainage cover body (21), a retaining body (22) and an outer body (23). The retaining body (22) is also provided with a wire feeding channel (222), which is used to feed the welding wire into the welding area. The outer body (23) includes an outer substrate (231) and an air-conducting cavity (232) that is in air communication with the outer substrate (231). High-pressure air is introduced into the outer substrate (231), and the air-conducting cavity (232) is used to make the high-pressure air flow out of the outer body (23) evenly.

2. The underwater laser welding torch according to claim 1, characterized in that, The drainage cover (2) is connected to the sealing housing (11) through the transmission part (111), and the drainage cover (2) and the sealing housing (11) are coaxially arranged.

3. The underwater laser welding torch according to claim 1, characterized in that, The laser head body (10) has an optical fiber inlet (15) at the end away from the drainage cover (2), and the welding mechanism (13) communicates with external devices through the optical fiber inlet (15).

4. The underwater laser welding torch according to claim 1, characterized in that, The welding mechanism (13) includes a first protection module (131), a collimation module (132), a focusing module (133), and a second protection module (134) disposed within the laser head body (10). The first protection module (131), the collimation module (132), the focusing module (133), and the second protection module (134) are arranged sequentially along the axial direction of the laser head body (10) from the direction away from the drainage cover to the direction closer to the drainage cover (2), and a laser lens (135) is provided between the collimation module (132) and the focusing module (133).

5. The underwater laser welding torch according to claim 4, characterized in that, The underwater laser welding torch also includes a positioning mechanism (12), which is disposed inside the laser head body (10) and is used to position and support the welding mechanism (13); The positioning mechanism (12) includes a positioning seat (121) disposed in the laser head body (10), the welding mechanism (13) is mounted on the positioning seat (121), and a sealing element is provided between the laser lens (135) and the positioning seat (121).

6. The underwater laser welding torch according to claim 2, characterized in that, The laser head body (10) is also provided with an air inlet (16), and the air inlet (16) is provided with a first filter screen (17). The first filter screen (17) is used to filter the gas entering through the air inlet (16), and the laser head body (10) is provided with a second filter screen (18). The second filter screen (18) is used to filter the air filtered by the first filter screen (17).

7. The underwater laser welding torch according to claim 6, characterized in that, The drain cover body (21) is connected to the sealing shell (11). The drain cover body (21) is provided with a connecting part (211) connected to the sealing shell (11). The retaining body (22) is connected to the end of the drain cover body (21) away from the sealing shell (11). The outer body (23) is connected to the end of the retaining body (22) away from the drain cover body (21).

8. The underwater laser welding torch according to claim 7, characterized in that, The laser head body (10) has a ventilation cavity (102) communicating with the air inlet (16). The drain cover body (21) has a first cavity (212) communicating with the ventilation cavity (102). The first cavity (212) is vented with air flowing in through the ventilation cavity (102). The cross-sectional diameter of the first cavity (212) gradually decreases from the direction near the connecting part (211) toward the fixed body (22). The retainer (22) has a second cavity (221) that communicates with the first cavity (212). The cross-sectional diameter of the second cavity (221) gradually increases from the direction near the connecting part (211) toward the retainer (22).

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