A device and method for live welding repair on ships

Abstract

This invention discloses a vessel live-line welding device and method. The welding device includes an outer cylinder, an inner cylinder for flow guidance, and at least two fixing components. The outer cylinder is fitted over the inner cylinder, and the inner cylinder extends beyond the outer cylinder. The outer and inner cylinders are sealed together by at least one annular connecting plate. The lower opening faces of the outer and inner cylinders are flush. An annular sealing ring is provided at the bottom of the inner cylinder, and a valve switch for controlling water flow is also provided on the inner cylinder. The fixing components are located on the outer periphery of the outer cylinder and are used to fix the outer cylinder to the ship's hull plate. The vessel live-line welding device provided by this invention ensures no water leakage in the area to be welded, thereby reducing the water pressure at the welding location, and simplifies the welding operation.

Description

Technical Field

[0001] This invention belongs to the field of marine live welding technology, specifically relating to a marine live welding device and a marine live welding method. Background Technology

[0002] During navigation or on-water construction operations, localized water leakage may sometimes occur on ships (see [reference]). Figure 1 As shown, if not addressed promptly and effectively, leaks can pose serious safety hazards to navigation or construction, especially in areas such as the bottom outer plating, side plating, and hull plating of sea passage devices at a certain depth below the waterline. Due to the large pressure difference between the inside and outside of the leak location and the high speed of the leaking water, the high-pressure water flow can blow away the molten weld pool during direct pressure welding, making direct pressure welding impossible. Transferring the vessel to a dedicated dry dock for thorough repair requires a long period, and some engineering vessels (such as dredgers) can only undergo complete overhaul after the project is finished, otherwise, it will have a serious negative impact on time and economic costs. Therefore, there is an urgent need for a temporary and effective pressure welding method that allows for rapid pressure welding, ensuring safe navigation and on-water construction operations for a certain period. Once conditions for major overhaul are met, the vessel can be transferred to a dry dock for complete replacement of the leaking area, such as removing a portion of the hull plating in the leaking area and replacing it with a new plating, which is then securely welded.

[0003] Currently, the existing technology involves using a clamping device (such as a jack) to press the weld repair cover plate onto the ship's hull plate, and then directly welding the circumferential perimeter of the lap joint between the weld repair cover plate and the ship's hull plate to repair the leak. For details, please refer to... Figure 2 As shown. However, this existing pressure welding method has the following drawbacks:

[0004] 1. Due to the lack of diversion and pressure relief measures during the repair welding process, the water pressure at the leak location is high, making it difficult to directly press the repair welding cover plate. Furthermore, there will always be localized water leakage at the weld cover plate. The high water pressure at the leak location makes the weld pool easily blown open by the high-pressure water flow, making repair welding difficult. Repair welding may need to be repeated, resulting in a low success rate and a long repair welding cycle. Moreover, the higher the water pressure, the more difficult the repair welding becomes, and it may even be impossible to completely repair the weld, only reducing the leakage flow rate per unit time (i.e., leakage speed). Since the leaking water cannot be completely diverted, water will continue to accumulate in the area to be welded and cannot be completely cleaned, resulting in poor working conditions for repair welding construction.

[0005] 2. Because the welding process is always in a state of local water leakage, the surrounding environment is humid and may even be partially flooded, welding repair (usually electric welding repair) poses a certain risk of electric shock, and the safety factor of welding repair operation is low.

[0006] 3. The repair welding site is always in a damp state, or even in direct contact with a water source with a certain pressure. The influence of water (especially the influence of hydrogen atoms) on the weld pool and the welding metallurgical process can easily cause hydrogen porosity defects in the weld (penetrating porosity defects can lead to water leakage), welding crack defects (caused by high diffusible hydrogen content in the weld), and high diffusible hydrogen content in the weld (which can lead to weld crack defects, especially delayed crack defects, and can also increase the brittleness and reduce the toughness of the weld, making it easy for the weld to break brittlely and leak during subsequent use). The welding quality of the repair weld is poor. Furthermore, during the repair welding at the leak location, the water directly contacts the molten weld pool, resulting in a significant cooling effect. This causes the molten weld pool to cool down too quickly, preventing some slag or gas (such as CO2) from escaping before it rapidly crystallizes and solidifies. This unexploded slag or gas forms inclusions or porosity defects. These defects reduce the effective cross-sectional area of ​​the weld, thus lowering its strength. After a period of use, weld cracking directly leads to leakage. Additionally, during the repair welding at the leak location, the water directly contacts the molten weld pool, resulting in a significant cooling effect. This causes the fusion zone at the contact point between the weld and the base material (the lower end of the ship's hull and cylinder 1) to have a low temperature, making it prone to incomplete fusion welding defects. These defects also reduce the effective cross-sectional area of ​​the weld, further lowering its strength. After a period of use, weld cracking directly leads to leakage. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes a vessel live welding device and a vessel live welding method. When using this device for vessel live welding, it can prevent water leakage in the area to be welded, reduce the water pressure at the welding location, simplify the welding operation, and ensure a stable weld pool due to the absence of water pressure in the welding area, resulting in a high welding success rate, short welding cycle, and complete leak prevention.

[0008] The technical solution of this invention is implemented as follows:

[0009] A pressure welding device for ships includes an outer cylinder, an inner cylinder for guiding water flow, and at least two fixing components. The outer cylinder is fitted over the inner cylinder and the inner cylinder extends out of the outer cylinder. The outer cylinder and the inner cylinder are sealed together by at least one annular connecting plate. The lower opening ends of the outer cylinder and the inner cylinder are flush. An annular sealing ring is provided at the bottom of the inner cylinder. A valve switch for controlling the flow of water is also provided on the inner cylinder. The fixing components are located on the outer periphery of the outer cylinder and are used to fix the outer cylinder to the ship's hull plate.

[0010] Preferably, the annular connecting plate includes a first annular connecting plate and a second annular connecting plate, wherein the first annular connecting plate is disposed near the upper opening of the outer cylinder, and the second annular connecting plate is disposed near the lower opening of the outer cylinder.

[0011] Preferably, the distance from the first annular connecting plate to the upper opening of the outer cylinder is 3-5cm, and the distance from the second annular connecting plate to the lower opening of the outer cylinder is 3-5cm.

[0012] Preferably, the fixing component includes a shaped magnet structure and a screw structure disposed outside the outer cylinder. The screw structure includes a bolt and a connecting plate. The connecting plate is distributed and fixed on the outer periphery of the outer cylinder. The bolt passes through the nut and the end of the connecting plate in sequence and is parallel to the outer cylinder. The outer cylinder can be pressed tightly onto the ship's hull plate by adjusting the nut. The shaped magnet structure is provided with a groove whose size matches the diameter of the bolt.

[0013] Preferably, the irregularly shaped magnet structure includes a semi-circular tubular magnet with the groove, a trapezoidal magnet, and a magnet switch. The semi-circular tubular magnet is connected to one side of the trapezoidal magnet, and the groove is located on the side away from the trapezoidal magnet. By adjusting the magnet switch, the irregularly shaped magnet structure is magnetically attracted to the bolt and the ship's hull plate.

[0014] Preferably, the diameter of the arc-shaped inner wall of the semi-circular tubular magnet is not less than the outer diameter of the bolt.

[0015] Preferably, a guide pipe is also fitted onto the upper end of the inner cylinder.

[0016] The present invention also provides a method for performing live welding on ships using the above-mentioned live welding device, comprising the following steps:

[0017] S1. Open the valve switch on the inner cylinder, align the center of the bottom of the inner cylinder with the leaking area of ​​the ship's hull plate and press it so that the leaking area is just inside the annular sealing ring. Then fix the ship's pressurized welding device to the ship's hull plate through the fixing components.

[0018] S2. The area to be welded at the lower end of the outer cylinder is sequentially treated with water, cleaned, and dried.

[0019] S3. After drying, use pre-treated welding rods to perform layered welding on the perimeter of the area to be welded between the lower end of the outer cylinder and the ship hull.

[0020] S4. After welding is completed, close the valve switch and check whether there is any water leakage around the welding device. After confirming that there is no water leakage, remove the relevant fixing components.

[0021] Preferably, in step S2, a layered welding method is used and at least two layers are welded. The weld joints between the layers of the layered welding are staggered by 30-50mm.

[0022] Preferably, in step S2, the pre-treated welding rod is an alkaline welding rod that has been dried at 300-350°C for 1 hour.

[0023] Compared with the prior art, the present invention has the following advantages.

[0024] This invention provides a ship live welding repair device. By comprising an outer cylinder, an inner cylinder for flow guidance, and an annular connecting plate for sealing between the outer and inner cylinders, the relative positions of the outer and inner cylinders can be fixed, and their lower ends are made flush. Furthermore, by setting an annular sealing ring at the bottom of the cylinder and a valve switch on the inner cylinder, when using this device for live welding repair, firstly, the valve switch is opened, the center of the cylinder of the live welding repair device is aligned with the leaking area of ​​the ship's hull and pressed tightly, so that the leaking area is exactly within the annular sealing ring, isolating and covering the leaking location. At this time, the annular sealing ring at the lower end of the inner cylinder is in contact with the ship's hull, while the lower end of the outer cylinder is still... Without direct contact, the pressure welding device is then fixed to the ship's hull plate using a fixing assembly. At this point, the annular sealing ring at the lower end of the inner cylinder deforms under pressure from the fixing assembly, creating a temporary watertight seal between the inner and outer sides of the lower opening of the inner cylinder. This prevents water from leaking from the inner cylinder to the lower end of the outer cylinder, ensuring a leak-free welding area at the lower end of the cylinder. Water leaking from the hull plate can be guided out through the upper opening of the inner cylinder, reducing pressure at the welding location during subsequent welding operations (pressure relief). The welding operation is simple, and because there is no water pressure in the welding area, the weld pool is stable, resulting in a high success rate, short welding cycle, and complete leak prevention. This method of using a ship pressure welding device for pressure welding reduces the difficulty of pressure welding on ship hull plates, improves the quality and efficiency of pressure welding, and ensures the safety and economic benefits of the ship during navigation and on-water operations. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the existing ship hull plating and the location of pressurized leaks.

[0027] Figure 2 A schematic diagram of existing methods for live welding repair on ships;

[0028] Figure 3 A schematic diagram showing the installation and fixing of a live welding repair device for a ship.

[0029] Figure 4 A schematic diagram showing the removal of fixed components from a live welding repair device for a ship.

[0030] Figure 5 for Figure 4 A-direction view;

[0031] Figure 6 A three-dimensional view of the connecting plate in a ship's live welding repair device;

[0032] Figure 7 A schematic diagram showing the connection between bolts and irregularly shaped magnets;

[0033] Figure 8 A flowchart for live welding repair on ships;

[0034] Figure 9 A schematic diagram showing the removal of the guide pipe and fixing components from the pressurized welding device on a ship after repair welding.

[0035] Attached diagram labels: 1. Outer cylinder;

[0036] 2. Inner cylinder;

[0037] 3. Annular connecting plate; 31. First annular connecting plate; 32. Second annular connecting plate;

[0038] 4. Annular sealing ring;

[0039] 5. Fixing components; 51. Connecting plate; 52. Bolt; 53. Irregularly shaped magnet structure; 531. Semi-circular tubular magnet; 532. Trapezoidal magnet; 533. Magnetic switch; 54. Nut;

[0040] 6. Ship hull plating;

[0041] 7. Valve switch;

[0042] 8. Drainage pipe;

[0043] 9. Welds. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Example 1

[0048] See Figures 3 to 7 This embodiment provides a ship live welding repair device, including an outer cylinder 1, an inner cylinder 2 for guiding water flow, and at least two fixing components 5. The outer cylinder 1 is fitted over the inner cylinder 1, and the inner cylinder 2 extends beyond the outer cylinder 1. The outer cylinder 1 and the inner cylinder 2 are sealed together by at least one annular connecting plate 3. The lower opening ends of the outer cylinder 1 and the inner cylinder 2 are flush. An annular sealing ring 4 is glued to the bottom of the inner cylinder 2. The annular sealing ring 4 is elastic. A valve switch 7 for controlling the flow of water is also provided on the inner cylinder 2. The fixing components 5 are located on the outer periphery of the outer cylinder 1 and are used to fix the outer cylinder 1 to the ship's hull plate 6. In this embodiment, there are four fixing components 5, which more securely fixes the ship live welding repair device to the ship's hull plate 6, facilitating subsequent welding repair operations on the leaking areas of the ship's hull plate 6.

[0049] This embodiment provides a ship live welding repair device. By configuring an outer cylinder 1, an inner cylinder 2 for flow guidance, and an annular connecting plate 3 for sealing between the outer cylinder 1 and the inner cylinder 2, the relative positions of the outer cylinder 1 and the inner cylinder 2 can be fixed, and the lower ends of the outer cylinder 1 and the inner cylinder 2 can be made flush. Then, by configuring an annular sealing ring 4 at the bottom of the inner cylinder 2 and a valve switch 7 on the inner cylinder 2, when using this device for live welding repair, firstly, the valve switch 7 is opened, the center of the inner cylinder 2 of the live welding repair device is aligned with the leaking area of ​​the ship's hull plate 7 and pressed tightly, so that the leaking area is exactly located within the annular sealing ring 4, isolating and covering the leaking area. At this time, the annular sealing ring 4 at the lower end of the inner cylinder 1 contacts the ship's hull plate 6, and the lower end of the outer cylinder 1 is in contact with the ship's hull plate 6. Before the hull plate 6 is in contact, the pressurized welding device is fixed to the hull plate 6 by the fixing component 5. At this time, the annular sealing ring 4 at the lower end of the inner cylinder 2 is deformed by the pressure transmitted from the fixing component 5 when it is fixed to the hull plate 6, so that the inner and outer sides of the lower opening end of the inner cylinder 2 are temporarily watertight. This can prevent water in the inner cylinder 1 from leaking through the area at the lower end of the inner cylinder 2 to the lower end of the outer cylinder 1, so that there is no water leakage in the area to be welded at the lower end of the outer cylinder 1. Moreover, the water leaking from the leaking area can be guided out through the upper opening of the inner cylinder 2. Thus, in the subsequent welding operation, the pressure at the welding position can be reduced (pressure relief). The welding operation is simple, and because there is no water pressure in the area where the welding is carried out, the weld pool is stable, the welding success rate is high, the welding cycle is short, and complete welding and leakage prevention can be achieved.

[0050] Furthermore, by diverting the leaking water from the upper opening of the inner cylinder 2, the pressure at the welding site can be reduced (i.e., pressure relief), ensuring the welding process remains water-free. This facilitates thorough cleaning and drying of the area to be welded, resulting in favorable conditions for subsequent welding operations and a high safety factor for welding repairs (generally electric welding repairs). Because the welding site remains dry, the weld pool does not come into contact with water, and the weld pool and welding metallurgical process are unaffected by water (especially by hydrogen atoms). This reduces the likelihood of hydrogen porosity defects, welding cracks, and low diffusible hydrogen content in the weld, leading to high-quality weld repairs.

[0051] Furthermore, during the repair welding operation, since there is no water leakage in the area to be repaired, the water does not directly contact the weld pool, and there is no cooling effect of water on the weld pool. The weld pool cools down at a normal rate, and the weld is less likely to form porosity defects. In addition, the fusion zone temperature at the contact position between the weld and the base material (the lower end of the ship's hull plate 6 and the outer cylinder 1) is high, making it less likely to produce non-fusion welding defects. As a result, the weld has high strength and a low probability of weld leakage.

[0052] The annular connecting plate 3 is connected to the outer cylinder 1 and the inner cylinder 2 by welding, which can more firmly seal the annular connecting plate 3 to the outer cylinder 1 and the inner cylinder 2.

[0053] Furthermore, the annular sealing ring 4 is an annular rubber ring, which has excellent sealing performance, effectively preventing liquid leakage. It can operate in high-temperature environments while maintaining excellent performance and tensile strength, making it suitable for the high-temperature working environment described in this invention. Its strong corrosion resistance and resistance to various chemicals extend its service life.

[0054] Furthermore, the annular connecting plate 3 includes a first annular connecting plate 31 and a second annular connecting plate 32. The first annular connecting plate 31 is disposed near the upper opening of the outer cylinder 1, and the second annular connecting plate 32 is disposed near the lower opening of the outer cylinder 1.

[0055] The distance from the first annular connecting plate 31 to the upper opening of the outer cylinder 1 is 3-5 cm, and the distance from the second annular connecting plate 32 to the lower opening of the outer cylinder 1 is 3-5 cm. In this embodiment, it is 3 cm.

[0056] In this embodiment, the first annular connecting plate 31 and the second annular connecting plate 32 are provided, which is more conducive to fixing the relative positions of the outer cylinder 1 and the inner cylinder 2. The distance from the first annular connecting plate 31 to the upper opening of the outer cylinder 1 is 3-5cm, and the distance from the second annular connecting plate 32 to the lower opening of the outer cylinder 1 is 3-5cm. This facilitates welding and fixation, and effectively prevents pressurized water from leaking through the local position of the annular sealing ring 4 into the area between the outer cylinder 1 and the inner cylinder 2 (i.e., the area between the second annular connecting plate 32 and the inner cylinder 2), thus avoiding the problem of welding failure. In addition, it can also effectively prevent the heat from welding the lower end of the outer cylinder 1 to the lower end face of the inner cylinder 2 during welding with the ship hull plate 6, thus preventing the annular sealing ring 4 from burning and preventing water leakage from the area of ​​the annular sealing ring 4 to the area to be welded.

[0057] Furthermore, the annular sealing ring 4 cannot be too thin. If it is too thin, it may prevent the lower end of the inner cylinder 2 from forming a temporary watertight seal when the annular sealing ring 4 is deformed under pressure. The annular sealing ring 4 also cannot be too thick. If it is too thick, the lower end of the outer cylinder 1 may not be able to get close to the ship's hull plate 6 when the annular sealing ring 4 is deformed under pressure, which is not conducive to subsequent welding operations. Therefore, the thickness of the annular sealing ring 4 is 2-3 mm, and in this embodiment it is 3 mm.

[0058] Furthermore, the fixing assembly includes a shaped magnet structure 53 and a screw structure located outside the outer cylinder 1. The screw structure includes a bolt 52 and a connecting plate 51. The connecting plate 51 is distributed and fixed on the outer periphery of the outer cylinder 1. The bolt 52 passes through the end of the connecting plate 51 and the nut 54 in sequence and is parallel to the outer cylinder 1. By adjusting the nut 54, the outer cylinder 1 can be pressed tightly onto the ship's hull plate 6. The shaped magnet structure 53 is provided with a groove whose size matches the diameter of the bolt 52.

[0059] In this embodiment, the bolt 52 passes through the end of the connecting plate 51 and the nut 54 in sequence and is parallel to the outer cylinder 1. Thus, the bolt 52 and the connecting plate 51 are detachably connected by the nut 54, which facilitates subsequent disassembly. At the same time, tightening the nut 54 can move the connecting plate 51 downward relative to the bolt 52, thereby pressing the outer cylinder 1 onto the ship hull plate 6. Furthermore, by providing a groove with a size matching the diameter of the bolt 52, the irregularly shaped magnet structure 53 can better magnetically attract the bolt 52.

[0060] Furthermore, the irregular magnet structure 53 includes a semi-circular tube magnet 531 with a groove, a trapezoidal magnet 532 and a magnet switch 533, wherein the semi-circular tube magnet 531 is connected to one side of the trapezoidal magnet 532 and the groove is located on the side away from the trapezoidal magnet 532. By adjusting the magnet switch 533, the irregular magnet structure 53 is magnetically attracted to the bolt 52 and the ship hull plate 6.

[0061] In this embodiment, the semi-circular tubular magnet 531 is provided with a groove, so that the bolt 52 can be accommodated in the groove. And through the magnet switch 533 provided in the irregular magnet structure 53, when the magnet switch 533 in the irregular magnet structure 53 is opened, the semi-circular tubular magnet 531 and the trapezoidal magnet 532 generate magnetism, so that the irregular magnet structure 53 is magnetically attracted to the bolt 52 and the ship hull plate 6. This can realize the lower end face of the bolt 52 to be fixed to the surface of the ship hull plate 6 without welding, which is convenient for fixing the ship's pressure repair welding device. The operation is simple and it is also convenient for the subsequent disassembly of the fixing component 5.

[0062] Furthermore, the trapezoidal magnet 532 can also be a rectangular magnet, but considering that the space at the leak location may be small, a trapezoidal magnet is preferred. The center of gravity of the trapezoidal magnet is close to the ship's hull plate 6, which facilitates its support function. Moreover, its light weight makes it easy to install and disassemble.

[0063] Specifically, the diameter of the arc-shaped inner wall of the semi-circular tube magnet 531 is not less than the outer diameter of the bolt 52. In this embodiment, the outer diameter of the bolt 52 is the same as the diameter of the arc-shaped inner wall of the semi-circular tube magnet 531, ensuring that the contact area between the two is maximized, thereby increasing the attraction between the bolt 52 and the semi-circular tube magnet 531.

[0064] Specifically, the irregularly shaped magnet structure 53 is positioned away from the outer cylinder 1 to provide sufficient construction space for subsequent welding.

[0065] Specifically, the upper end of the inner cylinder 2 is also fitted with a guide pipe 8, which makes it easier to conduct the water leaking from the ship's hull plate 6 to other locations. The area to be welded will not continuously accumulate water and can be thoroughly cleaned, resulting in good working conditions for the repair welding work.

[0066] When using this device for live welding repair on ships, firstly, valve switch 7 is opened to allow the inner cavity of the inner cylinder 2 to be unobstructed. Then, the center of the inner cylinder 2 is aligned with the leaking area of ​​the ship's hull plate 6 and pressed tightly, so that the leaking area is exactly within the annular sealing ring 4, isolating and covering the leaking area. At this time, the annular sealing ring 4 is in contact with the ship's hull plate 6, but the lower end of the outer cylinder 1 is not yet in contact with the ship's hull plate 6. Four bolts 52 are passed through the connecting plate 51 and nut 54 respectively. Then, four irregularly shaped magnet structures 53 (not all of the irregularly shaped magnet structures are shown in the figure) are installed in a position away from the outer cylinder 1, and the magnet switch 533 is turned on. At this time, the semi-circular tubular magnet 531 and the trapezoidal magnet 532 generate magnetism, thereby causing the irregularly shaped magnet structures 53 to be magnetically attracted to the bolts 52 and the ship's hull plate 6. This allows the welding repair device to be fixed to the ship's hull plate 6 without welding. Then, tightening the nut 54 causes the connecting plate 51 to move downwards relative to the bolt 52. At this time, the annular sealing ring 4 is deformed by the pressure transmitted from the tightening process of the nut 54, creating a temporary water seal between the inner and outer ends of the inner cylinder 2. This prevents water inside the inner cylinder 1 from leaking through the area at the lower end of the inner cylinder 2 to the lower end of the outer cylinder 1, ensuring no water leakage in the welding area at the lower end of the outer cylinder 1. Water leaking from the area can be guided out through the guide pipe 9, thus reducing the pressure at the welding location during subsequent welding operations (pressure relief). The welding operation is simple, and because there is no water pressure in the welding area, the weld pool is stable, resulting in a high success rate and a short welding cycle, achieving complete leak prevention. Simultaneously, the lower end of the outer cylinder 1 gradually approaches the ship's hull plate 6 (0-1mm), which is beneficial for subsequent welding operations.

[0067] Example 2

[0068] This embodiment provides a method for live welding repair on ships, such as... Figure 8 As shown, it includes the following steps:

[0069] S1. Determine the location of the leak, open the valve switch 7 on the inner cylinder 2, align the bottom center of the inner cylinder 2 with the leaking area of ​​the ship hull plate 6 and press it so that the leaking area is just inside the annular sealing ring 4, and then fix the ship pressure welding device on the ship hull plate 6 through the fixing component 5.

[0070] In step S1, the specific method for fixing the ship's pressurized welding device to the ship's hull plate 6 using the fixing component 5 is as follows: four bolts 52 are passed through the connecting plate 51 and the nut 54 respectively. Then, four irregularly shaped magnet structures 53 (not all of which are shown in the figure) are installed in a position away from the outer cylinder 1, and the magnet switch 533 is turned on. At this time, the semi-circular tube magnet 531 and the trapezoidal magnet 532 generate magnetism, which makes the irregularly shaped magnet structure 53 magnetically attracted to the bolts 52 and the ship's hull plate 6. This allows the welding device to be fixed to the ship's hull plate 6 without welding. Then, the nut 54 is tightened, which causes the connecting plate 51 to move downward relative to the bolts 52. At this time, the annular sealing ring 4 is deformed by the pressure transmitted from the tightening process of the nut 54, which temporarily seals the lower end of the inner cylinder 2 with water. At the same time, the lower end of the outer cylinder 1 gradually approaches the ship's hull plate 6 (0-1mm), which is beneficial to the subsequent welding construction.

[0071] S2. The area to be welded at the lower end of the outer cylinder 1 is sequentially treated with clean water, cleaned, and dried.

[0072] In step S2, the lower end of the outer cylinder 1 to be welded area is thoroughly cleaned with water, and then the lower end of the outer cylinder 1 to be welded area is dried using a gas flame.

[0073] S3. After drying, using pre-treated welding rods, perform layered welding on the perimeter of the area to be welded between the lower end of the outer cylinder 1 and the ship hull 6 to form weld 9 (e.g., Figure 1 (as shown);

[0074] In step S3, after drying, pre-dried (300-30℃, drying for 1 hour) alkaline welding rods (3.2mm or 4.0mm in diameter) are used to perform manual arc welding on the perimeter of the area to be welded at the lower end of the outer cylinder 1. The welding is done in layers, with at least 2 layers welded. The welding slag and welding defects of the previous layer must be completely removed before the next layer can be welded. The weld joints between layers must be staggered by 30-50mm to ensure the tightness of the weld joint position and the welding quality.

[0075] In step S3, if the staggered distance between weld joints is too small, such as less than 30mm, it may lead to insufficient weld overlap, easily resulting in welding defects such as incomplete fusion and slag inclusions. These defects will seriously affect the strength and sealing performance of the weld. Furthermore, an excessively small staggered distance may also cause uneven heat distribution during welding, resulting in significant residual stress. This stress may cause cracking when the weld is under stress. Conversely, if the staggered distance is too large, such as more than 50mm, it may result in insufficient tightness between welds, thus reducing weld strength and sealing performance. Under stress, this weak connection may cause the weld to crack or detach. Moreover, an excessively large staggered distance may require increasing the number of welding layers or passes, thereby prolonging welding time and reducing welding efficiency. Therefore, in this invention, the weld joints between layers need to be staggered by 30-50mm to ensure the tightness of the weld joint position and the welding quality.

[0076] S4. After welding is completed, close valve switch 7, remove guide pipe 9, check for water leakage around the welding device, and after confirming there is no water leakage, remove all irregularly shaped magnet structures 53 and bolts 52 (e.g., Figure 9 As shown in the figure, a live welding repair operation is completed.

[0077] It should be noted that when the ship is ready for major repairs, it will be transferred to a dry dock and dismantled along the weld seam between the lower end of the outer cylinder 1 and the ship's hull plate. After welding and grinding to repair it to the original size of the welding repair device, it can be reused for another pressurized welding repair of the ship according to the above steps S1-S4.

[0078] This invention provides a method for live welding repair on ships. By first isolating and covering the leaking area, diverting the leaking water, depressurizing, cleaning with clean water, drying and welding, and finally closing the valve, the live welding repair is completed. This method reduces the difficulty of live welding repair on ship hull plates, improves the quality and efficiency of live welding repair on ship hull plates, and ensures the safety of ships during navigation and on-water construction operations, as well as related economic benefits.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A marine live welding repair device, characterized in that, The device includes an outer cylinder (1), an inner cylinder (2) for guiding water flow, and at least two fixing components (5). The outer cylinder (1) is fitted over the inner cylinder (2), and the inner cylinder (2) extends out of the outer cylinder (1). The outer cylinder (1) and the inner cylinder (2) are sealed together by at least one annular connecting plate (3). The lower opening end faces of the outer cylinder (1) and the inner cylinder (2) are flush. An annular sealing ring (4) is provided at the bottom of the inner cylinder (2). A valve switch (7) for controlling the flow of water is also provided on the inner cylinder (2). The fixing components (5) are located on the outer periphery of the outer cylinder (1) and are used to fix the outer cylinder (1) to the ship's hull plate (6). The fixing component (5) includes a shaped magnet structure (53) and a screw structure located outside the outer cylinder (1). The screw structure includes a bolt (52) and a connecting plate (51). The connecting plate (51) is distributed and fixed on the outer periphery of the outer cylinder (1). The bolt (52) passes through the nut (54) and the end of the connecting plate (51) in sequence and is parallel to the outer cylinder (1). By adjusting the nut (54), the outer cylinder (1) can be pressed tightly onto the ship hull plate (6). The shaped magnet structure (53) is provided with a groove whose size matches the diameter of the bolt (52). The irregularly shaped magnet structure (53) includes a semi-circular tube magnet (531) with the groove, a trapezoidal magnet (532) and a magnet switch (533). The semi-circular tube magnet (531) is connected to one side of the trapezoidal magnet (532) and the groove is located on the side away from the trapezoidal magnet (532). By adjusting the magnet switch (533), the irregularly shaped magnet structure (53) is magnetically attracted to the bolt (52) and the ship hull plate (6).

2. The marine live welding repair device according to claim 1, characterized in that, The annular connecting plate (3) includes a first annular connecting plate (31) and a second annular connecting plate (32). The first annular connecting plate (31) is located near the upper opening of the outer cylinder (1), and the second annular connecting plate (32) is located near the lower opening of the outer cylinder (1).

3. The marine live welding repair device according to claim 2, characterized in that, The distance from the first annular connecting plate (31) to the upper opening of the outer cylinder (1) is 3-5cm, and the distance from the second annular connecting plate (32) to the lower opening of the outer cylinder (1) is 3-5cm.

4. The marine live welding repair device according to claim 1, characterized in that, The diameter of the arc-shaped inner wall of the semi-circular tube magnet (531) is not less than the outer diameter of the bolt (52).

5. The marine live welding repair device according to claim 1, characterized in that, The upper end of the inner cylinder (2) is also fitted with a guide pipe (8).

6. A method for performing live welding on a ship using the live welding apparatus according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Open the valve switch (7) on the inner cylinder (2), align the bottom center of the inner cylinder (2) with the water leakage area of ​​the ship hull plate (6) and press it tightly so that the water leakage area is just inside the annular sealing ring (4), and then fix the ship pressure repair welding device on the ship hull plate (6) through the fixing component (5). S2. The area to be welded at the lower end of the outer cylinder (1) is sequentially treated with water, cleaned and dried. S3. After drying, use pre-treated welding rods to perform layered welding on the perimeter of the area to be welded between the lower end of the outer cylinder (1) and the ship hull (6). S4. After welding is completed, close the valve switch (7) and check whether there is any water leakage around the welding device. After confirming that there is no water leakage, remove the relevant fixing components.

7. The method for live welding repair of ships according to claim 6, characterized in that, In step S2, a layered welding method is used during welding, and at least two layers are welded. The weld joints between the layers of the layered welding should be staggered by 30-50mm.

8. The method for live welding repair of ships according to claim 6, characterized in that, In step S2, the pre-treated welding rod is an alkaline welding rod that has been dried at 300-350°C for 1 hour.

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