Method and device for welding and polishing a conductor of a submarine cable flexible joint

Abstract

This invention discloses a method and apparatus for welding and grinding conductors of a submarine cable flexible joint. The method includes: unfolding the conductor filaments at the end of the submarine cable flexible joint layer by layer; aligning the end faces of the innermost single conductor filament and welding them; grinding the weld reinforcement; butt-jointing the ends of the corresponding conductor filaments in the next layer of the submarine cable in pairs; welding the butt-jointed conductor filaments in this layer using a rotary circumferential welding method; grinding the weld reinforcement; repeating the steps to complete the welding of all conductor filaments and the grinding of the welds layer by layer outwards. By unfolding the conductor filaments layer by layer and aligning the end faces of the conductor filaments from the inner layer outwards before rotary circumferential welding and grinding the corresponding outer diameters, the coaxiality of the butt joints and the continuity of the current path of each layer of conductor filaments can be effectively guaranteed, reducing the accumulation of thermal deformation and stress concentration caused by welding multiple conductors simultaneously, and improving the overall conductivity and mechanical strength of the flexible joint.

Description

Technical Field

[0001] This invention relates to the field of cable welding technology, and in particular to a device and method for welding and grinding conductors of submarine cable flexible joints. Background Technology

[0002] With the rapid development of deep-sea energy projects such as offshore wind power and cross-sea power grid interconnection, submarine cables are evolving towards longer lengths, larger cross-sections, and higher voltage levels. During the manufacturing, joint fabrication, and offshore repair of submarine cables, it is frequently necessary to reliably connect the conductors of two cable sections. Currently, for connecting large-section conductors, the industry mainly uses conventional welding methods, employing carbon arc welding or conventional fusion welding to butt the conductors. However, for multi-layer stranded submarine cable conductors, conventional welding presents the following problems: First, due to the large conductor cross-section and rapid heat dissipation, localized heat concentration occurs during welding, leading to significant thermal stress deformation in the conductor, making it difficult to ensure the roundness of the joint; second, welding the entire conductor can easily result in conductor misalignment and disordered single-wire overlaps, failing to meet the requirements for high reliability and long-term stable operation of submarine cable splices. Summary of the Invention

[0003] The purpose of this invention is to provide a method and apparatus for welding and grinding conductors of submarine cable flexible joints, so as to solve one or more technical problems existing in the background art.

[0004] To achieve this objective, the present invention adopts the following technical solution: A method for welding and grinding conductors of submarine cable flexible joints, the method comprising the following steps: S1. Unfold the conductor monofilaments at the ends of the flexible joints of the first and second submarine cables to be welded layer by layer. S2. Move the ends of the first and second submarine cables closer together, align the end faces of the innermost single conductor wires of the first and second submarine cables, and then weld them together. S3. Grind the weld reinforcement formed by welding so that the outer diameter of the weld is basically consistent with the conductor wire body. S4. Connect the ends of the conductor wires of the first submarine cable and the next layer of the second submarine cable to each other, and make the conductor wire to be welded surround and adhere to the outer periphery of the welded inner conductor. S5. The conductor wires of each joint in this layer are welded according to the set trajectory using a rotary circumferential welding method. S6. Grind the weld reinforcement at the weld joint of this layer so that the outer diameter after grinding is basically consistent with the standard outer diameter of the conductor single wire of this layer. S7. Repeat steps S4 to S6 to complete the welding of all conductor wires and the grinding of the weld seams layer by layer outwards.

[0005] Preferably, in steps S2 and S5, before welding, a 45° bevel, a 1mm blunt edge, and a 2mm assembly gap are formed at the end of the conductor monofilament. Then, the part to be welded is preheated before welding, and water-blocking material and impurities on the surface of the conductor monofilament are removed.

[0006] Preferably, in step S5, the set trajectory is to divide the outer circle formed by connecting the conductor single wires of this layer into a first arc segment, a fourth arc segment, a second arc segment and a third arc segment connected end to end in sequence, and the lengths of the four arc segments are equal; during welding, the first arc segment and the second arc segment are welded clockwise first, and then the third arc segment and the fourth arc segment are welded counterclockwise in sequence.

[0007] Preferably, in step S4, after pairing and attaching the conductor monofilaments to be welded to the outer periphery of the inner conductor, a binding device is used to temporarily fix the conductor monofilaments of the layer.

[0008] Preferably, the welding parameters during welding in steps S2 and S5 are: welding current 120A to 160A; welding wire diameter 1.6mm to 2.4mm.

[0009] Preferably, the welding parameters also include: a nozzle diameter of 8mm to 12mm; and a tungsten electrode diameter of 1.6mm to 2.4mm.

[0010] Preferably, the welding parameters also include: a shielding gas flow rate of 8 L / min to 15 L / min, and the shielding gas being one or more of argon or helium.

[0011] The present invention also provides a welding and grinding device for conductors of submarine cable flexible joints, for implementing the aforementioned welding and grinding method for conductors of submarine cable flexible joints, including a conveyor belt mechanism, a welding bracket, a circumferential motion component and a welding torch module; The conveyor belt mechanism includes two sets of conveyor belt assemblies arranged in a front-to-back manner, and the two sets of conveyor belt assemblies are respectively used to drive the first submarine cable and the second submarine cable to move axially. The welding bracket is located between the two sets of conveyor belt assemblies, and the welding bracket has an opening through which the submarine cable can pass. The circumferential motion component is located outside the opening, and the welding torch module is located at the movable end of the circumferential motion component.

[0012] Preferably, the circumferential motion component includes a circular track, a rotating movable seat, and a servo motion module. The servo motion module is disposed on the circular track, and the rotating movable seat is disposed on the movable belt of the servo motion module. The servo motion module is used to drive the rotating movable seat to move along the circular track.

[0013] Preferably, it also includes a linear module, which is disposed on the rotating movable seat, and the welding gun module is disposed at the movable end of the linear module. The linear module is used to drive the welding gun module to move closer to or away from the submarine cable being welded.

[0014] The beneficial effects of this invention are as follows: by unfolding the conductor monofilaments layer by layer and aligning the end faces of the conductor monofilaments from the inner layer to the outer layer before performing circumferential welding and grinding the corresponding outer diameters of each layer, the coaxiality of the conductor monofilaments and the continuity of the current path can be effectively guaranteed. This reduces the accumulation of thermal deformation and stress concentration caused by welding multiple conductors simultaneously, thereby improving the overall conductivity and mechanical strength of the flexible joint. By grinding the weld reinforcement after each layer is welded, the overall outer diameter of the joint is smoothly transitioned, reducing the risk of electric field concentration at the joint and adapting to the long-term stable use requirements of complex submarine laying and operating environments. Attached Figure Description

[0015] The accompanying drawings further illustrate the present invention, but the content of the drawings does not constitute any limitation on the present invention.

[0016] Figure 1 This is a flowchart of the welding and polishing method for the conductor of the submarine cable flexible joint according to Embodiment 1 of the present invention; Figure 2 This refers to the welding trajectory set in step S5 of embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the overall structure of the submarine cable flexible joint conductor welding and polishing device according to Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the circumferential motion component and welding torch module of Embodiment 2 of the present invention. Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1 This embodiment provides a method for welding and polishing the conductor of a submarine cable flexible joint, see attached figure. Figure 1 The method includes the following steps: S1. Unfold the conductor monofilaments at the ends of the flexible joints of the first and second submarine cables to be welded layer by layer. S2. Move the ends of the first and second submarine cables closer together, align the end faces of the innermost single conductor wires of the first and second submarine cables, and then weld them together. S3. Grind the weld reinforcement formed by welding so that the outer diameter of the weld is basically consistent with the conductor wire body. S4. Connect the ends of the conductor wires of the first submarine cable and the next layer of the second submarine cable to each other, and make the conductor wire to be welded surround and adhere to the outer periphery of the welded inner conductor. S5. The conductor wires of each joint in this layer are welded according to the set trajectory using a rotary circumferential welding method. S6. Grind the weld reinforcement at the weld joint of this layer so that the outer diameter after grinding is basically consistent with the standard outer diameter of the conductor single wire of this layer. S7. Repeat steps S4 to S6 to complete the welding of all conductor wires and the grinding of the weld seams layer by layer outwards.

[0019] By unfolding the conductor filaments layer by layer and aligning the end faces of the conductor filaments from the inner layer outwards before rotating and circumferentially welding them, and grinding the corresponding outer diameters to ensure consistency, the coaxiality of the conductor filaments in each layer and the continuity of the current path can be effectively guaranteed. This reduces the accumulation of thermal deformation and stress concentration caused by welding multiple conductors simultaneously, thereby improving the overall conductivity and mechanical strength of the flexible joint. By grinding the weld reinforcement after each layer of welding, a smooth transition of the overall outer diameter of the joint is ensured, reducing the risk of electric field concentration at the joint and adapting to the long-term stable use requirements of complex submarine laying and operating environments.

[0020] Preferably, in steps S2 and S5, before welding, a 45° bevel, a 1mm blunt edge, and a 2mm assembly gap are formed at the ends of the conductor wires. Then, the area to be welded is preheated, and water-blocking material and impurities on the surface of the conductor wires are removed. By setting a 45° bevel and a 1mm blunt edge at the ends of the conductor wires to be welded on the first and second submarine cables respectively before welding, and by creating a 2mm assembly gap between the conductor wires of the first and second submarine cables, a full and continuous weld is ensured after the conductor wires are joined, avoiding incomplete welding or overheating caused by insufficient contact surface. Since the conductor wire has a high thermal conductivity, preheating the area to be welded ensures that the base material can melt quickly during welding; simultaneously, preheating also reduces or eliminates diffusion porosity. By removing water-blocking material and impurities from the surface of the conductor wires in advance, carbonization of the water-blocking material and impurities can be prevented from entering the molten pool, reducing porosity and inclusion defects, further ensuring welding quality.

[0021] Preferred options are listed in the appendix. Figure 2 The set trajectory is to divide the outer circle formed by the splicing of the conductor single wires in this layer into the first arc segment, the fourth arc segment, the second arc segment and the third arc segment in sequence, with the four arc segments having the same length; during welding, the first arc segment and the second arc segment are welded in clockwise order, and then the third arc segment and the fourth arc segment are welded in counterclockwise order.

[0022] By dividing the outer circle formed by the jointing of the conductor wires in this layer into four arc segments connected end to end along the circumference, and adopting an alternating symmetrical welding sequence of first welding the first and second arc segments clockwise and then welding the third and fourth arc segments counterclockwise, the heating and cooling process of the weld can be evenly and symmetrically distributed along the circumference during the rotational circumferential welding process. This avoids the cumulative thermal stress and local thermal deformation caused by continuous welding, thereby preventing defects such as warping, misalignment, or radial bulging of the conductor wires in this layer due to uneven heating, and ensuring the concentricity and tightness of the welded conductors and the conductors to be welded in each layer.

[0023] Preferably, in step S4, after pairing and attaching the conductor wires to be welded to the outer periphery of the inner conductor, a binding device is used to temporarily fix the conductor wires of this layer. By adding a binding device for temporary fixation after pairing and attaching the conductor wires to be welded to the outer periphery of the inner conductor, the radial displacement and circumferential misalignment of each conductor wire in this layer can be effectively limited during the layer-by-layer butt welding and rotational circumferential welding process. This avoids positional displacement caused by its own weight, welding heat deformation, or rotational inertia, ensuring that each layer of conductor wires remains tightly attached to the inner layer of welded conductors, and improving the consistency of weld formation.

[0024] Preferably, the welding parameters in steps S2 and S5 are as follows: welding current 120A–160A; welding wire diameter 1.6mm–2.4mm; nozzle diameter 8mm–12mm; tungsten electrode diameter 1.6mm–2.4mm; shielding gas flow rate 8L / min–15L / min; and the shielding gas is one or a mixture of argon or helium. In this embodiment, a welding current of 130A, a welding wire diameter of 2mm, a nozzle diameter of 10mm, a tungsten electrode diameter of 2mm, a shielding gas flow rate of 10L / min, and argon gas with a purity of 99.9% or higher are selected.

[0025] Example 2 This embodiment provides a welding and grinding device for conductors of submarine cable flexible joints, used to implement the welding and grinding method for conductors of submarine cable flexible joints. (Refer to the attached document.) Figure 3 and 4 The device includes a conveyor belt mechanism, a welding support 2, a circumferential motion assembly, and a welding torch module 7; The conveyor belt mechanism includes two sets of conveyor belt assemblies arranged in front and behind each other. The two sets of conveyor belt assemblies 1 are used to drive the first submarine cable 8 and the second submarine cable 9 to move axially, respectively. The welding bracket 2 is located between the two sets of conveyor belt assemblies 1, and the welding bracket 2 has an opening for the submarine cable to pass through; The circumferential motion component is located on the outside of the opening, and the welding gun module 7 is located on the movable end of the circumferential motion component.

[0026] By setting up two sets of independently driven conveyor belt assemblies 1 arranged front and rear, the first submarine cable 8 and the second submarine cable 9 are moved axially, which facilitates the precise layer-by-layer docking and position adjustment of the conductor single wires of each layer of the flexible joint, saving manpower and providing stable support for the welding area. The circumferential motion assembly is installed on the outside of the opening and connected to the welding gun module 7, which can drive the welding gun to rotate around the outer circle of the conductor layer to be welded with high precision and start and stop in segments, thereby realizing layer-by-layer welding from the inside to the outside and alternating symmetrical welding of four arc segments. This ensures that each layer of weld is heated evenly, fully fused, and the outer diameter of the joint is round and consistent, effectively suppressing welding deformation and stress concentration, improving the electrical conductivity and mechanical strength of the flexible joint conductor. At the same time, this integrated structure reduces the manual repeated clamping and adjustment operations, improves the controllability and automation level of the welding process, and meets the high-quality construction requirements of long-length and large-section submarine cable flexible joints on site.

[0027] Preferably, the circumferential motion component includes a circular track 3, a rotating movable seat 4, and a servo motion module 5. The servo motion module 5 is mounted on the circular track 3, and the rotating movable seat 4 is mounted on the movable belt of the servo motion module 5. The servo motion module 5 drives the rotating movable seat 4 to move along the circular track 3. By cooperating with the circular track 3, the servo motion module 5 drives the rotating movable seat 4 and the welding torch module 7 to rotate around the outer circumference of the submarine cable to be welded. This enables the welding trajectory to be divided into four equal arc segments, with alternating clockwise and counterclockwise symmetrical welding, ensuring controllable arc initiation and termination positions and uniform heat input for the weld seams of each conductor layer. This improves the overall quality consistency of the submarine cable flexible joint conductor welding and the reliability of the automated operation of the device.

[0028] Preferably, the assembly also includes a linear module 6, which is mounted on the rotating movable base 4. The welding torch module 7 is located at the movable end of the linear module 6. The linear module 6 is used to move the welding torch module 7 closer to or further away from the submarine cable being welded. By adding the linear module 6 to the rotating movable base 4 and connecting it to the welding torch module 7, the welding torch module 7 can be moved radially forward and backward relative to the conductor of the flexible connector. This allows for automatic adjustment of the welding torch's extension length and welding angle from the surface to be welded when welding conductor wires of different diameter layers from the inside out. This eliminates the need for complete disassembly or fixture replacement to adapt to changes in the outer diameter of each conductor layer and the clearance requirements during grinding operations. Furthermore, by setting the linear module 6, the distance between the welding torch and the molten pool can be finely adjusted in real time according to the bevel root gap and weld reinforcement height, ensuring stable arc length and uniform penetration depth, and avoiding arc blow or poor fusion due to differences in diameter between layers. With the circumferential servo positioning of the circular track 3, precise control of the welding torch's spatial position is achieved, improving the process adaptability and forming quality stability of automated welding of multi-layer conductors for flexible joints, reducing manual intervention, and adapting to high-quality batch construction of large-section, multi-layer stranded submarine cable flexible joints.

[0029] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A method for welding and grinding conductors of a submarine cable flexible joint, characterized in that, The method includes the following steps: S1. Unfold the conductor monofilaments at the ends of the flexible joints of the first and second submarine cables to be welded layer by layer. S2. Move the ends of the first and second submarine cables closer together, align the end faces of the innermost single conductor wires of the first and second submarine cables, and then weld them together. S3. Grind the weld reinforcement formed by welding so that the outer diameter of the weld is basically consistent with the conductor wire body. S4. Connect the ends of the conductor wires of the first submarine cable and the next layer of the second submarine cable to each other, and make the conductor wire to be welded surround and adhere to the outer periphery of the welded inner conductor. S5. The conductor wires of each joint in this layer are welded according to the set trajectory using a rotary circumferential welding method. S6. Grind the weld reinforcement at the weld joint of this layer so that the outer diameter after grinding is basically consistent with the standard outer diameter of the conductor single wire of this layer. S7. Repeat steps S4 to S6 to complete the welding of all conductor wires and the grinding of the weld seams layer by layer outwards.

2. The method for welding and grinding conductors of a submarine cable flexible joint according to claim 1, characterized in that, In steps S2 and S5, before welding, a 45° bevel, a 1mm blunt edge, and a 2mm assembly gap are formed at the end of the conductor wire. Then, the part to be welded is preheated before welding, and water-blocking material and impurities on the surface of the conductor wire are removed.

3. The method for welding and grinding conductors of a submarine cable flexible joint according to claim 1, characterized in that, In step S5, the set trajectory is to divide the outer circle formed by the splicing of the conductor single wires in this layer into a first arc segment, a fourth arc segment, a second arc segment and a third arc segment connected end to end in sequence, and the lengths of the four arc segments are equal; during welding, the first arc segment and the second arc segment are welded clockwise first, and then the third arc segment and the fourth arc segment are welded counterclockwise.

4. The method for welding and grinding conductors of a submarine cable flexible joint according to claim 1, characterized in that, In step S4, after the conductor wires to be welded are paired and attached to the outer periphery of the inner conductor, the conductor wires of the layer are temporarily fixed by binding.

5. The method for welding and grinding conductors of a submarine cable flexible joint according to claim 1, characterized in that, The welding parameters during steps S2 and S5 are: welding current 120A~160A; welding wire diameter 1.6mm~2.4mm.

6. The method for welding and grinding conductors of a submarine cable flexible joint according to claim 5, characterized in that, Welding parameters also include: nozzle diameter of 8mm to 12mm; tungsten electrode diameter of 1.6mm to 2.4mm.

7. The method for welding and grinding conductors of a submarine cable flexible joint according to claim 6, characterized in that, Welding parameters also include: a shielding gas flow rate of 8 L / min to 15 L / min, and the shielding gas being one or more of argon or helium.

8. A device for welding and grinding conductors of submarine cable flexible joints, characterized in that, The method for implementing the welding and grinding method of submarine cable flexible joint conductor as described in any one of claims 1-7 includes a conveyor belt mechanism, a welding bracket, a circumferential motion component and a welding torch module. The conveyor belt mechanism includes two sets of conveyor belt assemblies arranged in a front-to-back manner, and the two sets of conveyor belt assemblies are respectively used to drive the first submarine cable and the second submarine cable to move axially. The welding bracket is located between the two sets of conveyor belt assemblies, and the welding bracket has an opening through which the submarine cable can pass. The circumferential motion component is located outside the opening, and the welding torch module is located at the movable end of the circumferential motion component.

9. The device for welding and grinding conductors of a submarine cable flexible joint according to claim 8, characterized in that, The circumferential motion component includes a circular track, a rotating movable seat, and a servo motion module. The servo motion module is mounted on the circular track, and the rotating movable seat is mounted on the movable belt of the servo motion module. The servo motion module is used to drive the rotating movable seat to move along the circular track.

10. The device for welding and grinding conductors of a submarine cable flexible joint according to claim 9, characterized in that, It also includes a linear module, which is mounted on the rotating movable seat, and the welding gun module is mounted on the movable end of the linear module. The linear module is used to move the welding gun module closer to or away from the submarine cable being welded.

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