Large-section molded line conductor stranding process

Abstract

The invention discloses a large-section molded line conductor stranding process, and belongs to the technical field of wire and cable preparation. According to the large-section molded line conductor stranding process, three-layer distributor plate equipment and stranding process parameter combination which are coordinated are disclosed, and the three-layer distributor plate equipment comprises a front guide wheel distributor plate, a middle limiting mold distributor plate and a rear guide wheel distributor plate which are sequentially and linearly arranged on stranding equipment in the advancing direction of molded line monofilaments; wherein the front guide wheel distributor plate is located at the most upstream and is provided with a guide wheel with a fine-tuning eccentric shaft design, the middle limiting mold distributor plate is located at the center of the structure and is provided with a special-shaped limiting groove matched with the section of a monofilament, the rear guide wheel distributor plate is located at the most downstream, and a plurality of independent guide wheel structures are adopted to stabilize a formed stranded wire core. And meanwhile, the stranding quality is improved in cooperation with specific molded wire monofilament width-height ratio control and a pre-torsion angle application range, the problem of molded wire monofilament stranding dislocation is solved, and the molded wire conductor filling coefficient and roundness are remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wire and cable preparation, and particularly relates to a large-section type wire conductor stranding process. BACKGROUND

[0002] In recent years, with the transformation of global energy structure towards clean and low-carbon, the offshore wind power industry has experienced rapid development, and the demand for deep sea and large-capacity wind farms continues to increase. At the same time, the dependence on long-distance and high-efficiency power transmission technology is increasing. Under this background, as the key equipment connecting offshore power generation devices and onshore power grids, the performance and reliability of medium and high voltage submarine cables and optical fiber composite submarine cables directly affect the operation efficiency of the entire system.

[0003] To meet the demand for large-capacity power transmission, cables are developing towards high voltage levels and large cross-sections, which puts higher requirements on the structural performance of the conductor. Type wire conductors have become the preferred conductor structure for the new generation of submarine cables due to their significant technical advantages. Compared with traditional round wire conductors, type wire conductors can achieve a very high filling factor due to their special geometric shape, effectively reducing the conductor outer diameter, reducing AC resistance, improving transmission capacity, and significantly improving water resistance, avoiding water penetration leading to insulation aging. Therefore, type wire conductors are particularly suitable for high-voltage, deep-water, and large-section submarine cable application environments, and have become an important direction for the evolution of the industry.

[0004] However, type wire conductors still face a series of process problems in actual stranding, restricting their full performance and large-scale application. The core problem is that type wire filaments are prone to uncontrollable "turning" during stranding into cables. This phenomenon specifically manifests as: the wide surface of the filament turns unexpectedly under the action of stranding torque and axial tension, causing the relative position between adjacent filaments to be disordered and unable to achieve the desired tight fitting structure.

[0005] The "turning" problem will directly cause a series of serious consequences. First, the position deviation of individual filaments will cause the overall structure of the conductor to be loose, increasing the internal gap, resulting in a significant decrease in the filling factor. The existence of the gap not only weakens the mechanical stability of the conductor, but more seriously provides a channel for water penetration, greatly reducing the water resistance of the submarine cable, and easily causing insulation failure risk in harsh environments of high voltage and high water depth. Second, inconsistent structure also leads to uneven current distribution, enhanced skin effect, and significantly increased AC resistance, resulting in decreased power transmission capacity and increased energy loss, directly affecting the economy and operation efficiency of the entire power transmission system.

[0006] Therefore, in the field of monofilament stranding manufacturing of profiled conductors, although existing technologies have achieved basic forming functions, there is still a key bottleneck in overcoming the "flipping" phenomenon when meeting the manufacturing requirements of large-section, high-precision submarine cable conductors. Firstly, the "flipping" problem of profiled monofilaments is particularly prominent. Due to the asymmetry of the geometry of the profiled monofilament cross-section, it is prone to wide-face flipping when subjected to complex spatial torques during stranding. This problem directly causes the monofilaments to deviate from their preset spatial positions, preventing adjacent monofilaments from achieving ideal interlocking. Structural misalignment occurs inside the conductor, increasing the internal gaps. This not only weakens the conductor's mechanical compactness but also severely affects the water-blocking performance of the submarine cable. Moisture easily penetrates along the gaps between monofilaments, causing the insulation layer to become damp and age, threatening the safety of the entire power transmission system. Furthermore, uneven structure also causes uneven current distribution, exacerbating the skin effect and significantly increasing AC resistance, ultimately leading to decreased transmission efficiency and increased energy loss.

[0007] Secondly, the limiting capability of existing stranding equipment is significantly insufficient. Currently, mainstream equipment still generally adopts a traditional design using a splitter plate and fixed guide wheels. While this method is effective in limiting the radial movement of individual filaments, it struggles to meet the specific requirements of stranding profiled filaments. On one hand, the guide wheel slot size is fixed, making it impossible to flexibly adapt to different cross-sectional profiled filaments. Changing product specifications requires stopping the machine to replace the splitter plate, severely impacting equipment utilization and production efficiency. On the other hand, traditional guide wheels can only provide radial constraints on the filaments, failing to effectively limit their circumferential rotational freedom. Due to this lack of effective control over the rotation of the filaments around their own axis, asymmetrical cross-section profiled filaments are highly susceptible to overturning under stranding tension, and the "overturning" problem cannot be fundamentally suppressed.

[0008] Third, the existing stranding process parameters lack scientific rigor and adaptability. Most existing processes do not fully consider the impact of the structural characteristics of the individual wires on the stranding process, often employing uniform stranding speed and tension parameters without dynamically adjusting them based on the different stress characteristics of the inner and outer layer wires during conductor stranding. The inner layer wires primarily bear compressive stress, while the outer layer wires also need to overcome centrifugal force. Uniform process parameters lead to significant deviations between the actual stress state of the inner and outer layer wires and the ideal state, further exacerbating the risks of wire misalignment, uneven tension, and overall structural instability, severely impacting the roundness and performance consistency of the final conductor.

[0009] Chinese patent CN116246842A, filed on March 20, 2023, discloses a production device for water-blocking irregularly shaped conductors in submarine cables. The device includes a guide assembly mounted annularly on a shaped wire guide wheel seat. The coating module has a coating cavity with openings at both ends. One end of the coating cavity is the inlet for the conductor, facing the shaped wire guide wheel seat. The other end is the outlet for the stranded conductor. The guide assembly has several guide wheels, one of which is a trapezoidal groove guide wheel with trapezoidal grooves on its circumference to accommodate the conductor. The core of this patent lies in water-blocking coating. The main purpose of the guide assembly is to guide the monofilament to the coating module for coating, rather than fundamentally preventing the monofilament from "turning over" during the stranding process. Therefore, it still relies on a traditional guide wheel structure with limited limiting capabilities, failing to effectively constrain the circumferential rotational freedom of the monofilament.

[0010] Chinese patent CN119207866A, filed on December 2, 2024, discloses a compressed conductor cable and its production compression molding system. The compressed conductor cable includes a center conductor, a first ring, a second ring, a third ring, a water-blocking insulation layer, and a sheath. The first ring is composed of several first fan-shaped conductors tightly fitted around the center conductor circumferentially. The second ring is composed of several second fan-shaped conductors tightly fitted around the first ring circumferentially. The third ring is composed of several Z-shaped conductors tightly fitted around the second ring circumferentially. The water-blocking insulation layer is fitted on the outside of the third ring, and the sheath is fitted on the outside of the water-blocking insulation layer. The technical approach of this patent is to first loosely twist the conductors and then forcefully compress them using an external mold to reduce the gap. However, this approach does not fundamentally solve the problem of controlling the initial posture of the single filaments during the twisting process. Furthermore, forced compression can easily lead to scratches on the surface of the single filaments, internal stress, and even metal fatigue.

[0011] In summary, existing large-section wire conductor stranding technologies are limited by issues such as the ease with which single filaments can "turn over," insufficient equipment positioning capabilities, and poor adaptability of process parameters. These limitations severely restrict the performance consistency and production efficiency of high-grade submarine cables. Therefore, developing an innovative technology that can precisely constrain the attitude of single filaments, dynamically adapt process parameters, and achieve stable and efficient stranding is of significant engineering application value and strategic importance for improving the overall performance of wire conductors and meeting the future needs of deep-sea and high-capacity power transmission. Summary of the Invention

[0012] To address the problems existing in the prior art, this invention provides a stranding process for large cross-section profiled conductors, which solves the problem of misalignment in the stranding of single wires, significantly improves the fill factor and roundness of the profiled conductor, enhances the structural consistency of the profiled conductor, and simultaneously supports the efficient production of multiple conductor specifications.

[0013] The technical solution of the present invention is as follows:

[0014] One of the objectives of this invention is to provide a stranding process for large cross-section wire conductors, which uses a three-layer wire splitter device to strand single wires to obtain large cross-section wire conductors. The three-layer wire splitter device includes a front guide wheel wire splitter, an intermediate limiting mold wire splitter, and a rear guide wheel wire splitter arranged in a straight line along the traveling direction of the single wires on the stranding device.

[0015] S1. Pre-treatment of profiled monofilaments: Select trapezoidal or fan-shaped profiled monofilaments with an aspect ratio greater than 1.2;

[0016] S2, Single Wire Limiting: The single wire of the profile is positioned by passing through the front guide wheel dividing plate, and then horizontally passes through the limiting mold which is evenly distributed in a circle on the middle limiting mold dividing plate. The limiting mold is provided with a limiting groove that matches the cross-sectional shape of the single wire of the profile. The radial constraint is completed under the circumferential constraint of the limiting groove, and then the wire is positioned again by the corresponding independent guide wheel on the rear guide wheel dividing plate.

[0017] S3. Pre-twist angle application: Apply a pre-twist angle of 15-20° to the profile single wire after it passes through the guide wheel dividing plate;

[0018] S4. Adjust the stranding parameters: Control the stranding pitch to 12-15 times the outer diameter of the conductor, and combine it with the rear guide wheel wire divider plate to control the tension of the inner and outer single filaments of the profile wire to strand the profile wire.

[0019] S5. Compression and shaping: Apply radial pressure to the stranded wire core to compress it, and obtain a large cross-section wire conductor.

[0020] Furthermore, in the three-layer wire splitter device, the front guide wheel wire splitter is located at the uppermost position and has a guide wheel with a finely adjustable eccentric shaft design; the middle limiting mold wire splitter is located at the center of the structure and has an irregularly shaped limiting groove that matches the cross-section of the single wire; the rear guide wheel wire splitter is located at the lowermost position and uses a structure of multiple independent guide wheels to stabilize the formed stranded wire core.

[0021] Furthermore, the front guide wheel on the front guide wheel distribution plate adopts a finely adjustable eccentric shaft design with an adjustment accuracy of ±0.1°.

[0022] Furthermore, the intermediate limiting mold dividing plate is provided with multiple sets of limiting grooves, the shape of which matches the cross-section of the profile wire, and the size is 1.04-1.06 times the cross-sectional size of the wire.

[0023] Furthermore, the cross-sectional area of ​​the single wire in the S1 medium-sized wire is 2500-3500 mm. 2 .

[0024] Furthermore, the limiting mold material in S3 is silicon carbide.

[0025] Furthermore, in S4, the tension control in the gradation is to apply 30-50 N / mm to the outer monofilament. 2 Tension of 20-30 N / mm is applied to the inner monofilament. 2 Tension.

[0026] Furthermore, in S4, the attitude fluctuation of the single filament of the profile is controlled within ±0.02° by using an independent guide wheel structure.

[0027] Furthermore, the radial pressure applied in S5 is 5.0-5.4 kN.

[0028] Furthermore, this process is applied to cross-sections of 2500mm². 2 The stranding of conductors of various shapes and sizes.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. This invention combines a three-layer wire separating plate equipment system with stranding process parameter control. First, for profiled wires with different cross-sections, a mold with matching limiting grooves is designed. This provides circumferential constraints to prevent the profiled wires from turning over, while retaining a small gap to avoid excessive friction. Then, the torsional torque generated during stranding is offset by reverse torque to prevent the profiled wires from turning over due to torque imbalance. Stranding and radial constraints are completed simultaneously under the constraint of the limiting grooves to ensure that the wires are tightly arranged. Afterward, the stranding process parameters are adjusted to ensure that the tension is applied evenly, so that the relaxation rate of the outer layer wires is reduced to below 0.05%, preventing the outer layer wires from relaxing due to insufficient tension.

[0031] 2. This invention breaks through the traditional single-layer design of the dividing plate and innovatively designs a three-layer structure of "front and rear guide wheel dividing plate + intermediate limiting mold dividing plate". Traditional dividing plates have fixed and non-adjustable guide wheels, and when the profiled wire enters the limiting structure, the initial tilt can easily cause the limiting groove to not fully fit. In this solution, the front guide wheel adopts a micro-adjustable eccentric shaft design, which can correct the initial position in real time according to the profiled wire cross-sectional specifications. The intermediate limiting mold dividing plate: the shape of the intermediate limiting groove can completely restrict the circumferential rotation of the wire, ensuring that the pre-twist angle is accurately applied to the axis of the profiled wire, offsetting the torsional torque generated during the twisting process; the rear guide wheel dividing plate, through the independent guide wheel corresponding to each profiled wire, ensures that the force deviation of the outer layer wire is ≤2N / mm. 2 Inner layer ≤1N / mm 2 This provides a uniform stress basis for the precise application of subsequent tension levels, avoiding structural misalignment caused by uneven stress.

[0032] 3. The process of this invention significantly improves the product performance and production efficiency of the profiled conductor, not only directly solving the "turnaround" problem, but also having engineering application value. Its modular equipment design supports 2500mm...2 The rapid production of conductors with different cross-sections greatly shortens the changeover time and enables rapid adaptation of single filaments of different specifications. It has strong versatility and provides a core technical solution for manufacturing high-performance, high-reliability multi-specification large-section submarine cables. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the three-layer splitter board device described in this invention; Figure 2 This is a schematic diagram of the structure of the intermediate limiting mold dividing plate and its limiting mold described in this invention; Figure 3 This is a schematic diagram of the structure of the rear guide wheel dividing plate described in this invention. Detailed Implementation

[0036] The present invention will be further described below with reference to preferred embodiments. The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values. These ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed herein.

[0037] Unless otherwise specified, the experimental methods in the following embodiments are conventional methods, performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions.

[0038] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0039] Example 1

[0040] This embodiment provides a 2500mm 2 The stranding process for large cross-section wire conductors includes the following steps:

[0041] 1) A single-wire (1+6+12+16+20+24+30) copper wire arrangement is adopted, and the outermost single wire width is set to 8.3mm and the height is 6.5mm, with a width-to-height ratio of 1.27;

[0042] 2) Install the front guide wheel dividing plate, the middle limiting mold dividing plate and the rear guide wheel dividing plate in sequence on the frame stranding machine, and adjust the guide wheel angle so that the single wire of the profile enters the limiting groove with a cross-sectional size of 1.05 times the single wire.

[0043] 3) After the single filament of the profiled wire passes through the outer guide wheel dividing plate, a pre-applied 18° twist angle is added;

[0044] 4) Position the single filament of the profile line through the irregularly shaped guide hole, and then horizontally pass through the intermediate limiting mold dividing plate with the limiting mold.

[0045] 5) Set the stranding pitch to 15 times the conductor's outer diameter, and control the tension of the inner and outer monofilaments of the profiled wire in stages, applying 35 N / mm to the outer monofilament. 2 A tension of 25 N / mm is applied to the inner monofilament. 2 The tension is used for twisting.

[0046] 6) Apply radial pressure to the stranded wire core for compaction. The compaction die roller pressure is 5.2kN.

[0047] Example 2

[0048] This embodiment provides a 3000mm 2 A stranding process for large cross-section wire conductors includes the following steps:

[0049] 1) A single-wire (1+6+12+16+20+24+30) copper wire arrangement is adopted, and the outermost single wire width is set to 8.6mm and the height is 6.9mm, with a width-to-height ratio of 1.24;

[0050] 2) Install the front guide wheel dividing plate, the middle limiting mold dividing plate and the rear guide wheel dividing plate in sequence on the frame stranding machine, and adjust the guide wheel angle so that the single wire of the profile enters the limiting groove with a cross-sectional size of 1.04 times the single wire.

[0051] 3) After the single filament of the profiled wire passes through the outer guide wheel dividing plate, a 15° twist angle is pre-applied;

[0052] 4) Position the single filament of the profile line through the irregularly shaped guide hole, and then horizontally pass through the intermediate limiting mold dividing plate with the limiting mold.

[0053] 5) Set the stranding pitch to 14 times the conductor's outer diameter, and control the tension of the inner and outer monofilaments of the profiled wire in stages, applying 40 N / mm to the outer monofilament. 2 A tension of 20 N / mm is applied to the inner monofilament. 2 The tension is used for twisting.

[0054] 6) Apply radial pressure to the stranded wire core for compaction. The compaction die roller pressure is 5.0kN.

[0055] Example 3

[0056] This embodiment provides a 3500mm 2 The stranding process for large cross-section wire conductors includes the following steps:

[0057] 1) A single-wire (1+6+12+16+20+24+30) copper wire arrangement is adopted, and the outermost single wire width is set to 9.2mm and the height is 7.5mm, with a width-to-height ratio of 1.23;

[0058] 2) Install the front guide wheel dividing plate, the middle limiting mold dividing plate and the rear guide wheel dividing plate in sequence on the frame stranding machine, and adjust the guide wheel angle so that the single wire of the profile enters the limiting groove with a cross-sectional size of 1.06 times the single wire.

[0059] 3) After the single filament of the profiled wire passes through the outer guide wheel dividing plate, a 20° twist angle is pre-applied;

[0060] 4) Position the single filament of the profile line through the irregularly shaped guide hole, and then horizontally pass through the intermediate limiting mold dividing plate with the limiting mold.

[0061] 5) Set the stranding pitch to 14 times the conductor's outer diameter, and control the tension of the inner and outer monofilaments of the profiled wire in stages, applying 40 N / mm to the outer monofilament. 2 Tension of 30 N / mm is applied to the inner monofilament. 2 The tension is used for twisting.

[0062] 6) Apply radial pressure to the stranded wire core for compaction. The compaction die roller pressure is 5.4kN.

[0063] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A stranding process for large cross-section wire conductors, characterized in that, A three-layer wire splitter is used to strand profiled wires to obtain a large cross-section profiled wire conductor. The three-layer wire splitter includes a front guide wheel wire splitter, an intermediate limiting mold wire splitter, and a rear guide wheel wire splitter arranged in a straight line along the direction of travel of the profiled wires on the stranding device. The twisting process includes the following steps: S1. Pre-treatment of profiled monofilaments: Select trapezoidal or fan-shaped profiled monofilaments with an aspect ratio greater than 1.2; S2, Single Wire Limiting: The single wire of the profile is positioned by passing through the front guide wheel dividing plate, and then horizontally passes through the limiting mold which is evenly distributed in a circle on the middle limiting mold dividing plate. The limiting mold is provided with a limiting groove that matches the cross-sectional shape of the single wire of the profile. The radial constraint is completed under the circumferential constraint of the limiting groove, and then the wire is positioned again by the corresponding independent guide wheel on the rear guide wheel dividing plate. S3. Pre-twist angle application: Apply a pre-twist angle of 15-20° to the profile single wire after it passes through the guide wheel dividing plate; S4. Adjust the stranding parameters: Control the stranding pitch to 12-15 times the outer diameter of the conductor, and combine it with the rear guide wheel wire divider plate to control the tension of the inner and outer single filaments of the profile wire to strand the profile wire. S5. Compression and shaping: Apply radial pressure to the stranded wire core to compress it, and obtain a large cross-section wire conductor.

2. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, In the three-layer wire splitter device, the front guide wheel wire splitter is located at the uppermost position and has a guide wheel with a finely adjustable eccentric shaft design; the middle limiting mold wire splitter is located at the center of the structure and has an irregularly shaped limiting groove that matches the cross-section of the single wire; the rear guide wheel wire splitter is located at the lowermost position and uses a structure of multiple independent guide wheels to stabilize the formed stranded wire core.

3. The stranding process for large cross-section wire conductors according to claim 2, characterized in that, The front guide wheel on the front guide wheel distribution plate adopts a finely adjustable eccentric shaft design with an adjustment accuracy of ±0.1°.

4. The stranding process for large cross-section wire conductors according to claim 2, characterized in that, The intermediate limiting mold dividing plate is provided with multiple sets of limiting grooves. The shape of the limiting grooves matches the cross-section of the single wire of the profile, and the size is 1.04-1.06 times the cross-sectional size of the single wire.

5. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, The S1 medium-weight wire has a single wire cross-section of 2500-3500 mm. 2 .

6. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, The limiting mold material in S3 is silicon carbide.

7. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, The tension control in S4 involves applying 30-50 N / mm to the outer monofilament. 2 Tension of 20-30 N / mm is applied to the inner monofilament. 2 Tension.

8. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, In S4, the independent guide wheel structure is used to stabilize the single filament attitude fluctuation of the profile and control it within ±0.02°.

9. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, The radial pressure applied in S5 is 5.0-5.4 kN.

10. The stranding process for large cross-section wire conductors according to claim 1, characterized in that, This process is applied to cross-sections of 2500mm². 2 The stranding of conductors of various shapes and sizes.

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