A method of manufacturing a crosslinked extruded insulated power cable

Abstract

The application belongs to the technical field of power cable application, and particularly discloses a manufacturing method of a cross-linking extrusion insulation power cable, which comprises the following steps: step 1, wire drawing and annealing; step 2, bundle and strand; step 3, stranding; step 4, two-layer co-extrusion plasticizing and power frequency spark inspection; step 5, silane cross-linking insulation core rewinding and cross-linking process; step 6, copper tape wrapping shielding layer; step 7, metal braiding shielding layer; step 8, cabling process; step 9, armoring process; and step 10, looping process.The manufacturing method of the cross-linking extrusion insulation power cable has the beneficial effects that: 1, the process flow design is reasonable, the product production preparation process is easy to control, the quality of the finished product produced is stable, the production cost is reduced, and the economic benefit is improved.

Description

Technical Field

[0001] This invention belongs to the field of power cable application technology, specifically relating to a method for manufacturing a cross-linked extruded insulated power cable. Background Technology

[0002] Wires and cables are wire products used to transmit electrical (magnetic) energy, information, and to achieve electromagnetic energy conversion. In a broad sense, wires and cables are also simply referred to as cables. In a narrow sense, a cable refers to an insulated cable, which can be defined as an assembly consisting of one or more insulated conductors, and their respective possible sheaths, overall protective layer, and outer sheath. Cables may also have additional uninsulated conductors.

[0003] Power cables come in a wide variety of types and specifications and have a broad range of applications. Most of them are used at voltages of 1kV and below. New products are constantly being developed to meet the needs of special applications, such as fire-resistant cables, flame-retardant cables, low-smoke halogen-free / low-smoke low-halogen cables, termite-proof cables, rodent-proof cables, oil-resistant / cold-resistant / heat-resistant / wear-resistant cables, medical / agricultural / mining cables, thin-walled wires, etc.

[0004] Cross-linked extruded insulated power cables are mainly used for transmitting electrical energy in power devices and power lines with a rated voltage of 0.6 / 1kV. However, the existing cross-linked extruded insulated power cables have unreasonable manufacturing processes, resulting in low product quality that does not meet the high standards required for their application.

[0005] To address the aforementioned problems, this invention provides a method for manufacturing cross-linked extruded insulated power cables. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies by providing a method for manufacturing cross-linked extruded insulated power cables, thereby improving the product quality of cross-linked extruded insulated power cables.

[0007] Technical Solution: This invention provides a method for manufacturing cross-linked extruded insulated power cables, comprising the following steps: Step 1, wire drawing and annealing, using an eleven-die copper wire drawing machine with an inlet diameter of 3.00mm and an outlet diameter of 1.13-2.85mm, and a maximum of 11 drawing passes; Step 2, stranding, using a GST-500 stranding machine with a pitch adjustment range of 6mm to 60mm and a production range of 0.5 to 2.5mm. 2Maximum number of strands: 84; maximum single filament diameter: 0.68 mm; JCJX-800XB high-speed cantilever stranding machine; pitch adjustment range: 30mm-200mm; applicable core outer diameter: Φ1.0mm-4.0mm; stranding direction: left-hand and right-hand. Step 3: Stranding, using JLC-400 / 6 fork stranding machine, JLC-400 / 6+12+18 fork stranding machine, or LC-400 / 6+12+18+24 fork stranding machine. The stranding process is performed using a wire stranding machine, either an LC-500 / 12+18+24 fork-type stranding machine or a JLK-500 / 12+18+24 frame-type stranding machine, with a stranding unit diameter of 1.0-5.0mm; Step 4: Two-layer co-extrusion and power frequency spark test, using an SJ-120×25+65×25 double-layer co-extrusion machine, with a power frequency spark test voltage of 10-25kV; Step 5: Rewinding and cross-linking process of the silane cross-linked insulated wire core, firstly, the insulated wire... The core is hoisted on the wire-laying frame, and the wire end is sealed tightly with plastic tape. The wire end is introduced into the meter-counting wheel, then the counter is reset to zero and the meter is recorded. The core is evenly arranged and rewound onto the take-up reel to begin take-up. During the rewinding process, a power frequency spark test is performed on the insulated core at the specified test voltage. If the insulated core breaks down, it is repaired with a special repair strip (same model and color). After repair, it should be retested. If the repair fails three times in a row, no further repairs are made. After rewinding, the end of the core is sealed and secured with a cable cap or self-adhesive plastic tape to prevent moisture from entering the insulated core during the cross-linking process in the steam chamber. Finally, the rewound silane cross-linked insulated core is transported to a warm water tank or steam chamber to prepare for cross-linking. Step 6: Copper tape wrapping shielding layer. First, adjust and select the wrapping head speed and traction gear according to the product structure. Then, the copper tape wrapping should be continuous and without gaps. The wrapping should be tight, flat, and wrinkle-free. The copper tape must be cut to 45 degrees when splicing. 0 Left and right welding is performed, ensuring reliable welding. The overlap rate of the copper tape wrapping should be no less than 15%. The insulation must be cooled to room temperature before copper tape shielding. During shielding, attention should be paid to the wire cores. If any abnormalities are found, the machine should be stopped immediately. The inner diameter of the final take-up reel should be no less than 40 times the outer diameter after shielding. The wire cores after loading should be at least 50mm lower than the edge of the reel. After unloading and passing inspection, the wire cores should be transported to the designated location and stacked in a T-shape. Step 7: Metal braided shielding layer. Use a GBZ-16A braiding machine with a maximum diameter of 16mm before braiding or a JMB-24 braiding machine with a maximum diameter of 20mm before braiding. Match the mold according to the cable core structure dimensions. The mold aperture should be 2-4mm larger than the braided outer diameter. The specific control and adjustment should be based on the cable core structure. Step 8: Cable forming process. Use an LK-400 / 6+12 stranding machine, which produces control cables with 19 cores or less, computer cables with 19 pairs or less, and some other types of cables. Alternatively, use a JCL-1250 / 2+3 cable forming machine, which produces cables with 10-300mm diameters. 2Power cables, electrical equipment wires and cables, control cables, communication cables, computing cables, compensating cables, and other special cables; Step 9, armoring process, using a KZ-630 armoring machine, producing medium and low voltage power cables or the armoring device (630 armoring head) in the JL-400 / 12+18 cable-forming machine unit, producing 0.75-6mm... 2 Power cables, control cables, communication cables, computing cables, compensating cables and other special cables; Step 10, coiling process, using a medium-sized coiling machine for coiling wire and cable products with a diameter of 5.0-35mm or a high-speed coiling machine for coiling wire and cable products with a diameter of 1-4.5mm.

[0008] In step 1 of this technical solution, the copper wire round copper wire adopts a continuous drawing and annealing process. When the wire diameter is 3.00mm, the wire exit speed is 1.0-5.6m / s, the annealing current is 4-9A, and the annealing voltage is 25-50V.

[0009] In step 2 of this technical solution, the gears are replaced according to the pitch length requirements. The pitch ratio of the bundled wires is L / D, where L is the pitch length and D is the stranded outer diameter, not exceeding 25 times. The pitch of 7 bundled wires is controlled to be no more than 20 times. The operation is as follows: ① First, the fine copper wires are pulled out from the pay-off frame and passed through the ceramic holes on the wire separating plate. Then, they pass through a suitable wire-jointing die, through the shaft center hole, through the guide wheel and the guide wheel on the bow frame, and then into the rear shaft center hole. They are then led to the traction wheel and pulley until they are wound around the take-up reel 3 to 4 times, while pressing down the wire tail. ② Close the protective cover, slowly start the trial run, bundle for 8 to 10 meters, stop the machine and check whether the stranded pitch meets the requirements and whether the tension of the take-up reel is appropriate. If not, adjust it. ③ After the first bundled wire core is taken up to 20 to 30 meters, stop the machine, pull out 2 to 3 meters from the take-up reel to measure the pitch, and confirm whether it meets the specified requirements. Only after the inspection is qualified can the machine be officially started.

[0010] In this technical solution, in step (3), A. Stranding method: There are two stranding methods for conductive wire cores: stranding without untwisting and stranding with untwisting. ① Wire cores stranded using the untwisting method do not have torsional internal stress, so they are mostly used for loose stranded wires to avoid them from spreading out when a single wire breaks due to internal stress. ② Stranding without untwisting is mostly used for tightly compressed wire cores because the residual stress generated by self-twisting is elastic deformation, while compression is plastic deformation, so the internal stress can be eliminated after compression. B. Stranding direction ① Regardless of whether the bare stranded wire is concentrically stranded or re-stretched, its outermost layer is always right-handed (Z-shaped). ② For conductors used to cover the insulation layer, the outermost layer is left-handed (S-shaped). ③ Whether right-handed or left-handed, the stranding direction of adjacent layers must be opposite. This is for product uniformity, ease of connection, and to prevent loosening of individual wires. C. Parallel Die: ① The parallel die is an important control point for stranded wire: the uniformity of the stranded wire diameter, the presence of serpentine strands, missing strands, and skipping phenomena are all reflected here. ② A stranding die typically consists of two semicircles. The inner hole of a steel die is chrome-plated, but a hardwood die can also be used. ③ The function of the stranding die is to sizing and shaping the stranded wire cores. Experience shows that the die's aperture should be slightly smaller than the calculated outer diameter by 0.1–0.3 mm. D. Compacting: Compacting is mainly used for stranding insulated conductors. Bare wires are generally not compacted. ① The purpose of compacting: a) to increase the fill factor, reduce conductor geometry, and save insulation and sheathing materials; b) to improve conductor surface smoothness and uniformity. Electric field, c) Reduce the chance of voids forming in the cable; ② Compacting process: a) The compacting process of round stranded conductors is that the first and third passes are vertical compacting, and the second and fourth passes are horizontal compacting; the first and second passes have a compaction amount of 80%, and the third and fourth passes have a rounding effect with a compaction amount of 20%; compared with non-compacted conductors, the outer diameter of round compacted conductors can be reduced by 7.2-9.17%, and the fill factor (regular stranding) can be increased from 75% to 90-93%; b) Sector stranded conductors 25-50mm 2 Only one vertical clamping operation is required; 70mm 2 After the outermost layer of conductors of 100 and above is stranded, it is subjected to three compressions: vertical, horizontal and vertical compressions. The first compression is 85%, the second compression is for shaping (both sides), and the third compression is for shaping. The filling coefficient of the compressed sector conductor can reach 90-93%.

[0011] In step 4 of this technical solution, the screw is first cleaned with polyethylene material or washing material. If the extruder previously produced PVC material, the screw should be removed and thoroughly cleaned. Then, the die head is cleaned. The molds of the two extruders are selected according to the process requirements. When reinstalling, a 60-mesh filter should be placed in front of the aluminum plate at the connection between the machine body and the die head. If necessary, three layers of 60-mesh + 80-mesh + 60-mesh filters can be placed. If cross-linked polyethylene insulation material is used, it is divided into A material and B material. The required ratio should be specified and the mixture should be mixed evenly. The temperature is set according to the control requirements. During the heating process, the ammeter pointer should be observed. If there is any abnormality, it should be reported and repaired in time. After heating to the control temperature, it is observed whether the design temperature is consistent with the actual temperature. The temperature of the homogenization section must be guaranteed to reach the grafting temperature of the silane cross-linked material. After the insulation core exits, it enters the cooling water tank. The cooling adopts a gradient cooling method. The temperature of the first section of the water tank must be guaranteed to be around 70°C. Finally, the power frequency spark test is performed when extruding the insulation.

[0012] In this technical solution, in step 8, (1) the arrangement order of wire core identification and wiring, A, power cable, ① two cores: red, blue or using digital code 1.0; ② three cores: red, yellow, green or using code 1, 2, 3; ③ four cores: red, yellow, green, blue or digital code 1.2.3.0; ④ five cores: red, yellow, green, blue, black (green / yellow can be used according to customer needs) or using 1.2.3.4.0 or 1.2.3.4.5, where 0 represents neutral core or grounding insulated core, green / yellow represents grounding insulated core, 10mm 2 A. Cross-linked polyethylene insulated wire cores can be identified using corresponding color strips; B. Control cables, ① Control cable wire cores are identified by color coding or digital coding. The outermost layer can use a yellow / green bicolor wire. The order of the digitally coded wire cores is: clockwise from the inside to the outside, starting from 1; ② Color spectrum of control cable insulated wire cores, 1) No preferred color spectrum for two-core cables; 2) Three-core cables: yellow / green, blue, brown, or blue, black, brown;

[0013] 3) Four-core cable: yellow / green, blue, black, brown, or blue, black, brown, black, or brown; 4) Five-core cable: yellow / green, blue, black, brown, black, or brown, or blue, black, brown, black, or brown; 5) Cables with more than five cores: one core is yellow / green and one core is blue in the outer layer, and the other insulated cores are the same color, but not green, yellow, light blue, or brown; in other layers, one core is brown, and the other insulated cores are the same color, but not green, yellow, light blue, or brown; in yet another layer, one core is brown, and the other insulated cores are the same color, but not green, yellow, light blue, or brown; C. The identification and arrangement of the cores of PVC insulated and PVC sheathed wires and cables with a rated voltage of 450 / 750V and below shall be in accordance with GB / T 5023-2008 and JB / T respectively. The 8734-2016 standard shall be implemented; D. The insulation cores of computer cables and other special cables shall be arranged in accordance with the corresponding chromatographic confirmation method or determined according to the production notification.

[0014] In this technical solution, the cabling in step 8 is generally completed using multiple molds. (1) The diameter of the first mold is 1.0 to 2.5 mm larger than the diameter of the cable core, and it only serves to close the cable and prevent the fan-shaped cable from flipping over. (2) The diameter of the second mold is 0 to 0.6 mm smaller than the diameter of the cable core, and it serves to tighten the cable for the first time. (3) The diameter of the third mold (if any) is 0 to 0.4 mm smaller than the diameter of the cable, and it serves to shape the cable. The shorter the distance between the wrapping tape and the wrapping tape mold, the tighter the cable will be.

[0015] In this technical solution, step 8, the formulas for calculating the outer diameter of the fan-shaped and tile-shaped cables are as follows: 1) D = R × 2, where D represents the outer diameter of the cable, R represents the height of the insulated core (this formula is not applicable when the width of the insulated core exceeds twice the height); 2) D = Mh (2 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.00), and h represents the height of the fan-shaped section; 3) D = Mh (3 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.11), and h represents the height of the fan-shaped section; 4) D = Mh (4 cores) ), where D—represents the outer diameter of the cable, M—represents the empirical coefficient of the outer diameter ratio, which is taken as 2.20, and h—represents the height of the sector; 5) D=Mh(3+1 core), where D—represents the outer diameter of the cable, M—represents the empirical coefficient of the outer diameter ratio, which is taken as 2.31, and h—represents the height of the sector; 6) D=2h+d(4+1, 3+2, five cores), where D—represents the outer diameter of the cable, h—represents the thickness of the corrugated shape, and d—represents the diameter of the small circle; 7) D=2.154h+d(4+1, 3+2, five cores), where D—represents the outer diameter of the cable, h—represents the thickness of the corrugated shape, and d—represents the diameter of the small circle.

[0016] In step 9 of this technical solution, only one type of steel strip thickness is allowed to be used in the same cable reel. Both layers of steel strip are intermittently wrapped in a right-hand direction. The wrapping should be tight and flat. The overlap of the upper and lower layers of steel strip should not be less than 25% of the width of the steel strip. The wrapping gap should not be greater than 50% of the width of the cable. The steel strip must be lap-welded. The steel strip joint should be cut at a 45° bevel. The bevel should be parallel to the cable axis after wrapping. The overlap at the joint should be 3-10mm. If the joint surface is rough, it should be repaired to be flat and firm. There should be no burrs, sharp corners, or other defects on the joint edge. The steel strip armor wrapping should be tight and there should be no gaps. Steel strips with inclusions, burrs, sand holes, or rust defects should be removed. The tension of the steel strip wrapping should be controlled. The tension is greatest when the reel is full, otherwise the steel strip is easy to fly out. When the reel is half full, it should be loosened, otherwise it will damage the cable or cause the steel strip to curl, thus damaging the cable core.

[0017] In this technical solution, the diameter of the coil (disc) in step 10 is determined according to the product specifications and length of the coil, and the outer dimensions of the coil of the same specification and length are kept consistent each time. The coil length is 100m, and the deviation is no more than ±0.5m. The length is measured with a meter counter. Short segments with a length of not less than 10m are allowed to be delivered, and their quantity shall not exceed 10% of the total delivery length. Each short segment shall not exceed 5 segments.

[0018] Compared with the prior art, the beneficial effects of the method for manufacturing a cross-linked extruded insulated power cable of the present invention are as follows:

[0019] 1. Its process flow design is reasonable, the product production and preparation process is easy to control, the quality of the finished products is stable, the production cost is reduced, and the economic benefits are improved. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0021] Figure 1 This is a schematic diagram illustrating the pitch ratio adjustment of a method for manufacturing a cross-linked extruded insulated power cable according to the present invention.

[0022] Figure 2 This is a schematic diagram of the temperature setting in a method for manufacturing a cross-linked extruded insulated power cable according to the present invention;

[0023] Figure 3 This is a schematic diagram of the spark test voltage for a method of manufacturing a cross-linked extruded insulated power cable according to the present invention.

[0024] Figure 4 This is a schematic diagram of the crosslinking temperature in a method for manufacturing a crosslinked extruded insulated power cable according to the present invention.

[0025] Figure 5 , Figure 6 This is a schematic diagram illustrating the core structure control and adjustment of a cross-linked extruded insulated power cable manufacturing method according to the present invention.

[0026] Figure 7 This is a schematic diagram showing the nominal thickness of the armored metal tape in a method for manufacturing a cross-linked extruded insulated power cable according to the present invention. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that the terms "top," "bottom," and "side" are used interchangeably.

[0029] "The other side", "the front", "the back", "the middle part", "the inside", "the top",

[0030] The orientation or positional relationship indicated by terms such as "bottom end" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two elements. For those skilled in the art, the specific meaning of the above terms in the invention can be understood according to the specific circumstances.

[0031] Example

[0032] This invention discloses a method for manufacturing a cross-linked extruded insulated power cable, comprising the following steps: Step 1, wire drawing and annealing, using an eleven-die copper wire drawing machine with an inlet wire diameter of 3.00 mm and an outlet wire diameter of 1.13-2.85 mm, and a maximum of 11 drawing passes; Step 2, stranding, using a GST-500 stranding machine with a pitch adjustment range of 6 mm to 60 mm and a production range of 0.5 to 2.5 mm. 2 Maximum number of strands: 84; maximum single filament diameter: 0.68 mm; JCJX-800XB high-speed cantilever stranding machine; pitch adjustment range: 30mm-200mm; applicable core outer diameter: Φ1.0mm-4.0mm; stranding direction: left-hand and right-hand. Step 3: Stranding. Use a JLC-400 / 6 fork-type stranding machine, or a JLC-400 / 6+12+18 fork-type stranding machine, or an LC-400 / 6+12+18+24 fork-type stranding machine, or an LC-500 / 12+18+24 fork-type stranding machine, or a JLK-500 / 12+18+24 frame-type stranding machine for stranding. The stranded unit diameter is 1.0-5.0mm. Step 4: Two-layer co-extrusion and power frequency spark test. Use an SJ-120×25+65×25 double-layer co-extrusion machine. Power frequency spark test. The test voltage is 10-25kV; Step 5: Rewinding and cross-linking process of silane cross-linked insulated wire core. First, suspend the insulated wire core on the pay-off frame, seal the wire end with plastic tape, and guide the wire end into the meter counting wheel. Then, reset the count to zero and count the meters. Arrange the wire core evenly and rewind it onto the take-up reel to start taking up the wire. During the rewinding process, perform a power frequency spark test on the insulated wire core at the specified test voltage. If the insulated wire core breaks down, repair it with a special repair strip (same model and same color). After repair, it should be retested. If the repair fails three times in a row, no further repairs will be made. After rewinding, seal and fix the end of the wire core with a cable cap or plastic self-adhesive tape to prevent moisture from entering the insulated wire core during the cross-linking process in the steam chamber. Finally, transport the rewinded silane cross-linked insulated wire core to the warm water tank or steam chamber to prepare for cross-linking. Figure 4 Step 6: Wrap the copper strip around the shielding layer. First, adjust and select the wrapping head speed and traction gear according to the product structure. Then, the copper strip wrapping should be continuous and without gaps. The wrapping should be tight, flat, and wrinkle-free. When splicing the copper strip, it must be cut to 45 degrees. 0After welding on both sides, ensure reliable welding. The overlap rate of the copper tape wrapping should be no less than 15%. The insulation must be cooled to room temperature before copper tape shielding. During shielding, pay attention to the wire core. If any abnormality is found, stop the machine immediately. The inner diameter of the final take-up reel should be no less than 40 times the outer diameter after shielding. The wire core after loading should be at least 50mm lower than the edge of the reel. After unloading and passing inspection, transport to the designated location and stack in a T-shape. Step 7: Metal braided shielding layer. Use a GBZ-16A braiding machine with a maximum diameter of 16mm before braiding or a JMB-24 braiding machine with a maximum diameter of 20mm before braiding. Match the mold according to the cable core structure dimensions. The mold aperture should be 2-4mm larger than the braided outer diameter. The specific control and adjustment should be based on the cable core structure. Figure 5 and Figure 6 Step 8, cabling process: Use an LK-400 / 6+12 stranding machine for producing control cables with 19 cores or less, computer cables with 19 pairs or less, and some other types of cables; or use a JCL-1250 / 2+3 cabling machine for producing cables with diameters of 10-300mm. 2 Power cables, electrical equipment wires and cables, control cables, communication cables, computing cables, compensating cables, and other special cables; Step 9, armoring process, using a KZ-630 armoring machine, producing medium and low voltage power cables or the armoring device (630 armoring head) in the JL-400 / 12+18 cable-forming machine unit, producing 0.75-6mm... 2 Power cables, control cables, communication cables, computing cables, compensating cables and other special cables, with nominal thickness of armored metal tape ( Figure 7 Step 10, Coiling process: Use a medium-sized coiling machine for coiling wire and cable products with a diameter of 5.0-35mm, or a high-speed coiling machine for coiling wire and cable products with a diameter of 1-4.5mm.

[0033] Preferably, in step 1, the copper wire round copper wire adopts a continuous drawing and annealing process. When the wire diameter is 3.00mm, the wire exit speed is 1.0-5.6m / s, the annealing current is 4-9A, and the annealing voltage is 25-50V.

[0034] Preferably, in step 2, the gears are replaced according to the pitch length requirements, and the pitch ratio of the bundled wires is L / D, where L is the pitch length and D is the stranded outer diameter, not exceeding 25 times. The pitch of the 7 bundled wires is controlled to be no more than 20 times. The operation is as follows: ① First, the thin copper wire is pulled out from the pay-off frame and passed through the ceramic holes on the wire separator plate, then through a suitable wire-jointing die, through the shaft center hole, then through the guide wheel and the guide wheel on the bow frame, then into the rear shaft center hole, and led to the traction wheel and pulley until it is wound around the take-up reel 3 to 4 times, while pressing down the wire tail; ② Close the protective cover, slowly start the trial run, bundle for 8-10m, stop the machine to check whether the stranded pitch meets the requirements, and whether the tension of the take-up reel is appropriate. If not, adjust it; ③ After the first bundled wire core is taken up to 20-30m, stop the machine, pull out 2-3m from the take-up reel to measure the pitch, confirm whether it meets the specified requirements, and only after the inspection is qualified can it be officially started. Figure 1 Regulations are in place to control this.

[0035] Preferably, in step (3), A. Stranding method: There are two stranding methods for conductive wire cores: stranding without untwisting and stranding with untwisting. ① Wire cores stranded using the untwisting method do not have torsional internal stress, so they are mostly used for loosely compressed stranded wires to avoid them from spreading out when a single wire breaks due to internal stress. ② Stranding without untwisting is mostly used for tightly compressed wire cores because the residual stress generated by self-twisting is elastic deformation, while compression is plastic deformation, so the internal stress can be eliminated after compression. B. Stranding direction:

[0036] ① Regardless of whether the bare stranded wire is concentrically stranded or re-stretched, its outermost layer is always right-handed (Z-shaped). ② For conductors used to cover the insulation layer, the outermost layer of the strand is left-handed (S-shaped). ③ Whether right-handed or left-handed, the stranding directions of adjacent layers must be opposite. This is for product uniformity, ease of connection, and to prevent loosening of individual wires. C. Parallel Die: ① The parallel die is an important control point for stranded wire: the diameter uniformity of the stranded wire, the presence of serpentine strands, missing strands, and skipping phenomena are all reflected here. ② The parallel die is generally composed of two semicircles. The inner hole of the steel die is chrome-plated. Hardwood dies can also be used. Practice has shown that wooden dies are more practical. Steel dies are not only more expensive, but more importantly, they can scratch the conductor and easily cause burrs on the wire core. ③ The function of the parallel die is to sizing and shaping the stranded wire core. Experience shows that the hole diameter ratio of the parallel die is calculated... A slightly smaller outer diameter of 0.1–0.3 mm is suitable; D. Compacting: Compacting is mainly used for stranding insulated conductors. Bare wires are generally not compacted. ① Purpose of compacting: a) Increase the fill factor, reduce the conductor geometry, and save insulation and sheathing materials; b) Improve the smoothness of the conductor surface and uniformize the electric field on the conductor surface; c) Reduce the chance of voids forming in the cable; ② Compacting process: a) The compacting process for round stranded conductors is as follows: the first and third passes are vertical compacting, and the second and fourth passes are horizontal compacting; the first and second passes have a compaction amount of 80%, and the third and fourth passes have a rounding effect with a compaction amount of 20%; compared with non-compacted conductors, the outer diameter of a round compacted conductor can be reduced by 7.2–9.17%, and the fill factor (regular stranding) can be increased from 75% to 90–93%; b) Sector-shaped stranded conductors 25–50 mm 2 Only one vertical clamping operation is required; 70mm 2 After the outermost layer of conductors of 100 and above is stranded, it is subjected to three compressions: vertical, horizontal, and vertical compression. The first compression is 85%, the second is for shaping (both sides), and the third is for shaping. The filling coefficient of the compressed fan-shaped conductor can reach 90-93%. ③ Comparison between compressed and non-compressed conductors: a) Process characteristics: improved efficiency, reduced consumption, and structural stability; b) Electric field strength: can play a role in uniform electric field; c) Flexibility: somewhat reduced; d) Amount of structural materials: reduced, plastic power cable saves about 1.8% of material usage.

[0037] Preferably, in step 4, the screw is first cleaned with polyethylene material or washing material. If the extruder previously produced PVC material, the screw should be removed and thoroughly cleaned. Then, the die head is cleaned. The molds of the two extruders are selected according to process requirements. During reinstallation, a 60-mesh filter should be placed in front of the aluminum plate at the connection between the machine body and the die head. If necessary, three layers of 60-mesh + 80-mesh + 60-mesh filters can be placed. If cross-linked polyethylene insulation material is used, divided into A and B materials, the required ratio should be specified for uniform mixing according to (…). Figure 2The control requires setting the temperature. During heating, the ammeter pointer should be observed. Any abnormalities should be reported and repaired promptly. After heating to the control temperature, check whether the design temperature matches the actual temperature. The homogenization section temperature must be guaranteed to reach the grafting temperature of the silane crosslinking material. After the insulated core exits, it enters the cooling water tank. Gradual cooling is used. The temperature of the first section of the water tank must be maintained at around 70℃. Finally, a power frequency spark test is performed during the extrusion insulation. Figure 3 ).

[0038] Preferably, in step 8, (1) the order of core identification and wiring is as follows: A. Power cable, ① Two cores: red, blue or using digital code 1.0; ② Three cores: red, yellow, green or using code 1, 2, 3; ③ Four cores: red, yellow, green, blue or digital code 1.2.3.0; ④ Five cores: red, yellow, green, blue, black (green / yellow can be used according to customer needs) or using 1.2.3.4.0 or 1.2.3.4.5, where 0 represents the neutral core or the grounding insulated core, green / yellow represents the grounding insulated core, 10mm 2 A) Cross-linked polyethylene insulated wire cores can be identified using corresponding color strips; B) Control cables: ① Control cable wire cores are identified by color coding or digital encoding. The outermost layer can use a yellow / green bicolor wire. The order of the digitally encoded wire cores is clockwise from the inside out, starting from 1; ② Color spectrum of control cable insulated wire cores: 1) No preferred color spectrum for two-core cables; 2) Three-core cables: yellow / green, blue, brown, or blue, black, brown; 3) Four-core cables: yellow / green, blue, black, brown, or blue, black, brown, black, or brown; 4) Five-core cables: yellow / green, blue, black, Brown, black, or brown, or blue, black, brown, black, or brown, black, or brown; 5) Cables with more than five cores: one core is yellow / green and one core is blue in the outer layer, and the other insulated cores are the same color, but not green, yellow, light blue, or brown; in other layers, one core is brown, and the other insulated cores are the same color, but not green, yellow, light blue, or brown; in yet another layer, one core is brown, and the other insulated cores are the same color, but not green, yellow, light blue, or brown; C. The identification and arrangement of the cores of PVC insulated and PVC sheathed wires and cables with a rated voltage of 450 / 750V and below shall be carried out in accordance with GB / T 5023-2008 and JB / T 8734-2016 standards, respectively; D. The arrangement of the insulated cores of computer cables and other special cables shall be confirmed by the corresponding colorimetric method or determined according to the production notification.

[0039] Preferably, in step 8, the cabling is generally completed using multiple molds. (1) The diameter of the first mold is 1.0 to 2.5 mm larger than the diameter of the cable core, and it only serves to close the core and prevent the fan-shaped core from flipping over. (2) The diameter of the second mold is 0 to 0.6 mm smaller than the diameter of the cable core, and it serves to tighten the core for the first time. (3) The diameter of the third mold (if any) is 0 to 0.4 mm smaller than the diameter of the cable, and it serves to shape the core. The shorter the distance between the wrapping tape and the wrapping tape mold, the tighter the cabling will be.

[0040] Preferably, in step 8, the formulas for calculating the outer diameter of the fan-shaped and tile-shaped cables are as follows: 1) D = R × 2, where D represents the outer diameter of the cable, R represents the height of the insulated core (this formula is not applicable when the width of the insulated core exceeds twice the height); 2) D = Mh (2 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.00), and h represents the height of the fan-shaped section; 3) D = Mh (3 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.11), and h represents the height of the fan-shaped section; 4) D = Mh (4 cores) ), where D—represents the outer diameter of the cable, M—represents the empirical coefficient of the outer diameter ratio, which is taken as 2.20, and h—represents the height of the sector; 5) D=Mh(3+1 core), where D—represents the outer diameter of the cable, M—represents the empirical coefficient of the outer diameter ratio, which is taken as 2.31, and h—represents the height of the sector; 6) D=2h+d(4+1, 3+2, five cores), where D—represents the outer diameter of the cable, h—represents the thickness of the corrugated shape, and d—represents the diameter of the small circle; 7) D=2.154h+d(4+1, 3+2, five cores), where D—represents the outer diameter of the cable, h—represents the thickness of the corrugated shape, and d—represents the diameter of the small circle.

[0041] Preferably, in step 9, only one type of steel strip thickness is allowed to be used in the same cable reel. Both layers of steel strip are intermittently wrapped in a right-hand direction. The wrapping should be tight and flat, with an overlap of no less than 25% of the steel strip width. The wrapping gap should not exceed 50% of the cable width. The steel strip must be lap-welded. The steel strip joint should be cut at a 45° bevel, and the bevel should be parallel to the cable axis after wrapping. The overlap at the joint should be 3-10mm. If the joint surface is rough, it should be repaired to be flat and firm. There should be no burrs, sharp corners, or other defects on the joint edge. The steel strip armor wrapping should be tight and there should be no gaps. Steel strips with inclusions, burrs, sand holes, or rust defects should be removed. The tension of the steel strip wrapping should be controlled. The tension is greatest when the reel is full; otherwise, the steel strip may fly out. When the reel is half full, it should be loosened; otherwise, it may damage the cable or cause the steel strip to curl, thus damaging the cable core.

[0042] Preferably, in step 10, the diameter of the coil (disc) is determined according to the product specifications and length of the coil, and the outer dimensions of the coil of the same specification and length are kept consistent each time. The coil length is 100m, and the deviation is no more than ±0.5m. The length is measured with a meter counter. Short segments with a length of not less than 10m are allowed to be delivered, and their quantity shall not exceed 10% of the total delivery length. Each short segment shall not exceed 5 segments.

[0043] Furthermore, the cross-linked extruded insulated power cable packaging method of this invention...

[0044] (1) Reel packaging: The cable reel should be selected correctly, and its size, firmness, load capacity and cable bending radius should be appropriate; the bending radius should generally be no less than 20 times the outer diameter of the cable; the outer surface of the cable reel should be flat and free of obvious defects; the inner surface of the side plate and the outer surface of the cylinder should be smooth and flat, the gaps in the plate surface should be repaired and planed, and the sharp edges should be blunted.

[0045] (2) Manual soft packaging: Rewound wires and cables should be placed on a tray or lifting strap; the extruder should determine the height and outer diameter of the soft packaging according to the work order requirements and the outer diameter and length of the cable to facilitate the operation of the next process;

[0046] Packaging requirements for flexible packaging of wires and cables: Single-core cables: The inner diameter should be no less than 20 times the outer diameter of the finished cable. Each layer should have 20-40 turns, with a maximum outer diameter not exceeding 1 meter. Bundles should be 100-300 meters long, and each bundle should be tightly bound three times. Multi-core cables: 6mm² 2 For multi-core cables of the following diameters: inner coil diameter 300-400mm, single layer turns 15-20, bundled in 250-400m bundles, each bundle should be tightly bound 3 times. 0-35mm 2 Multi-core cable: Inner coil diameter 400-600mm, single layer number of turns 10-15, bundled together in 150-300 meter bundles, each bundle should be tightly bound 3 times. 50-95mm 2 Multi-core cable: Inner coil diameter 600-900mm, single layer number of turns 8-12, maximum outer coil length not exceeding 1.2 meters, bundled together in 80-120 meter bundles, each bundle should be tightly bound 4 times. 120mm 2 Multi-core cables of 900-1200mm diameter, 5-8 turns per layer, maximum outer diameter not exceeding 1.5 meters, bundled together in bundles of 40-70 meters, each bundle should be tightly bound 4 times.

[0047] The arrangement should be flat, free from scratches, scrapes, and mechanical damage; the first end should extend sufficiently for testing and meter verification; a minimum distance of 4 meters should be maintained between continuous product sections for easy handling; the outer diameter should be relatively large (50mm). 2Cables of type 1 and above (and above) should be packaged or bundled as appropriate. When packaging, first wrap the cable with braided wrapping tape, overlapping and securing it firmly, ensuring no exposed cable body. Then wrap it with plastic film, overlapping and securing it tightly without gaps or looseness (the meter marks at both ends of the cable should be visible for easy quantity verification). The product certificate and test report should be placed in a sealed bag and securely wrapped around the cable head to prevent them from falling off.

[0048] It should be noted that, in this document, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for manufacturing a cross-linked extruded insulated power cable, characterized in that: Includes the following steps, Step 1: Wire drawing and annealing. Use an eleven-die copper wire drawing machine with an inlet wire diameter of 3.00mm and an outlet wire diameter of 1.13-2.85mm. The maximum number of drawing passes is 11. Step 2: Bundling the stranded wires using a GST-500 wire bundling machine. The pitch adjustment range is 6mm to 60mm, and the production range is 0.5 to 2.5mm. 2 The maximum number of strands is 84, the maximum diameter of a single filament is 0.68, and it adopts the JCJX-800XB high-speed cantilever stranding machine. The pitch adjustment range is 30mm-200mm, the applicable core outer diameter is Φ1.0mm-4.0mm, and the stranding direction is left and right. Step 3: Twisting the wire. Use a JLC-400 / 6 fork-type stranding machine, or a JLC-400 / 6+12+18 fork-type stranding machine, or an LC-400 / 6+12+18+24 fork-type stranding machine, or an LC-500 / 12+18+24 fork-type stranding machine, or a JLK-500 / 12+18+24 frame-type stranding machine to twist the wire. The unit diameter of the twisted wire is 1.0-5.0mm. Step 4: Two-layer co-extrusion and power frequency spark test. The SJ-120×25+65×25 double-layer co-extrusion extruder is used, and the power frequency spark test voltage is 10-25kV. Step 5: Rewinding and cross-linking process of silane cross-linked insulated wire core. First, the insulated wire core is hoisted on the pay-off frame, and the wire end is sealed with plastic tape. The wire end is introduced into the meter counting wheel, and then the count is reset to zero and the meter is counted. The wire core is evenly arranged and rewound onto the take-up reel to start taking up the wire. During the rewinding process, the insulated wire core is subjected to a power frequency spark test at the specified test voltage. If the insulated wire core breaks down, it is repaired with a special repair strip of the same model and color. After repair, it should be retested with a spark test. If the repair fails three times in a row, no further repair is required. After the rewinding is completed, the end of the wire core is sealed and fixed with a cable cap or plastic self-adhesive tape to prevent moisture from entering the insulated wire core during the cross-linking process in the steam chamber. Finally, the rewinded silane cross-linked insulated wire core is transported to the warm water tank or steam chamber to prepare for cross-linking. Step 6: Copper tape wrapping shielding layer. First, adjust and select the wrapping head speed and traction gear according to the product structure. Then, keep the copper tape wrapping continuous and without omissions. The wrapping should be tight, flat, and wrinkle-free. When splicing the copper tape, cut it at about 45° and then weld it. The overlap rate of the copper tape wrapping should not be less than 15%. After the insulation cools to room temperature, perform copper tape shielding. Finally, the inner diameter of the take-up reel should not be less than 40 times the outer diameter after shielding. The wire core after loading the reel should be 50mm lower than the edge of the reel. After the reel passes inspection, stack it in a T-shape. Step 7: Metal braided shielding layer. Use a GBZ-16A braiding machine with a maximum diameter of 16mm or a JMB-24 braiding machine with a maximum diameter of 20mm before braiding. Prepare the mold according to the cable core structure size. The mold hole diameter should be 2-4mm larger than the braided outer diameter. Step 8, Cable Forming: Use an LK-400 / 6+12 stranding machine to produce control cables and computer cables with 19 cores or less, or a JCL-1250 / 2+3 cable forming machine to produce cables with a diameter of 10-300mm. 2 Power cables, electrical equipment wires and cables, control cables, communication cables, computing cables, and compensating cables; Step 9, Armoring Process: The KZ-630 armoring machine is used for medium and low voltage power cables, or the JL-400 / 12+18 cable-laying machine unit has an armoring range of 0.75-6mm. 2 Power cables, control cables, communication cables, computing cables, and compensating cables; Step 10, Coiling process: Use a medium-sized coiling machine to coil wire and cable products with a diameter of 5.0-35 mm or a high-speed coiling machine to coil wire and cable products with a diameter of 1-4.5 mm.

2. The method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 1, the copper wire round copper wire adopts a continuous drawing and annealing process. When the wire diameter is 3.00mm, the wire exit speed is 1.0-5.6m / s, the annealing current is 4-9A, and the annealing voltage is 25-50V.

3. The method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 2, the gears are replaced according to the pitch length requirements. The pitch ratio of the bundled wires is L / D1, where L is the pitch length and D1 is the outer diameter of the strand. The ratio is no more than 25 times, and the pitch of the 7 bundled wires is controlled to be no more than 20 times. The operation is as follows: ① First, the thin copper wire is pulled out from the wire feeding frame, passes through the ceramic holes on the wire separating plate, then through the appropriate wire connecting die, through the shaft center hole, then through the guide wheel and the guide wheel on the bow frame, then into the rear shaft center hole, and led to the traction wheel and pulley until it is wound around the take-up reel 3 to 4 times, while pressing down the end of the wire. ② Close the protective cover, slowly start the trial run, bundle for 8-10 m, stop the machine and check whether the stranding pitch meets the requirements and whether the tension of the take-up reel is appropriate. If not, adjust accordingly. ③ After the first bundle of wire cores has been wound up to 20-30 m, stop the machine and pull out 2-3 m from the take-up reel to measure the pitch. Confirm whether it meets the specified requirements. After the inspection is qualified, start the machine officially.

4. The method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 3 A. Stranding method: There are two stranding methods for conductive wire cores: untwisted stranding and twisted stranding with untwisted twisting. ① The core stranded by the untwisting method has no torsional internal stress and is used for non-tightly twisted wires to avoid the internal stress spreading when a single wire breaks. ② Stranding without untwisting is used for tightly twisted cores. The residual stress generated by self-twisting is elastic deformation, while that generated by compression is plastic deformation. The internal stress disappears after compression. B. Stranding direction: ① Regardless of whether the bare stranded wire is concentrically stranded or re-stretched, its outermost layer is specified to be right-handed. ② For conductors used to cover the insulation layer, the outermost layer of the stranding is left-handed. ③ Whether right-handed or left-handed, the stranding directions of adjacent layers are opposite, which facilitates connection and prevents single wires from becoming loose. C. Parallel line mode; D. Compacting: Compacting is used for stranding insulated conductors. Bare wires are not compacted. ① Purpose of compaction: a) Increase the fill factor, reduce conductor geometry, and save insulation and sheathing materials; b) Improve conductor surface smoothness and uniform conductor surface electric field; c) Reduce the chance of voids forming in the cable; ② Compacting process: a) For round stranded conductors, the first and third compaction passes are vertical, and the second and fourth passes are horizontal; the first and second passes have a compaction amount of 80%, and the third and fourth passes have a rounding effect with a compaction amount of 20%; compared with uncompacted conductors, the outer diameter of a round compacted conductor is reduced by 7.2-9.17%, and the fill factor is increased from 75% to 90-93%; b) For fan-shaped stranded conductors, the diameter is 25-50mm. 2 Only one vertical compression is performed; 70 mm 2 After the outermost layer of conductors of 100 and above is stranded, it is subjected to three compressions: vertical compression, horizontal compression, and vertical compression. The first compression is 85%, the second compression is for shaping, and the third compression is for fixing. The filling coefficient of the compressed sector conductor is 90-93%.

5. The method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 4 First, clean the screw with polyethylene material or machine cleaning material; Then clean the extruder head, select the molds of the two extruders according to the process requirements, and when reinstalling, place a 60-mesh filter in front of the aluminum plate at the connection between the machine body and the extruder head, or place three layers of 60-mesh + 80-mesh + 60-mesh filters. If cross-linked polyethylene insulation material is used, it is divided into A material and B material. Mix them evenly according to the specified ratio, set the temperature according to the control requirements, and observe the swing of the ammeter pointer during the heating process. When the temperature reaches the control temperature, observe whether the design temperature is consistent with the actual temperature. When the homogenization section temperature reaches the grafting temperature of the silane cross-linked material, the insulation core enters the cooling water tank after exiting. The cooling adopts a gradient cooling method, and the temperature of the first section of the water tank is about 70℃. Finally, a power frequency spark test is performed during the extrusion insulation process.

6. The method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 8, (1) the order of core identification and wiring: A. Power cable, ① Two cores: red, blue or digital code 1.0; ② Three cores: red, yellow, green or digital code 1.2.3; ③ Four cores: red, yellow, green, blue or digital code 1.2.3.0; ④ Five cores: red, yellow, green, blue, black or digital code 1.2.3.0.4; B. Control Cables: ① Control cables use color coding or digital encoding for core identification. The outermost layer uses a yellow / green bicolor wire. The order of the digitally encoded cores is clockwise from the inside out, starting from 1. ② Color spectrum of the control cable insulation cores: 1) Two-core cables: no preferred color spectrum; 2) Three-core cables: yellow / green, blue, brown, or blue, black, brown; 3) Four-core cables: yellow / green, blue, black, brown, or blue, black, brown, black, or brown; 4) Five-core cables: yellow / green, blue, black, brown, black, or brown. C. The identification and arrangement of conductors for PVC sheathed wires and cables with rated voltage of 450 / 750V and below shall be performed in accordance with GB / T5023-2008 and JB / T 8734-2016 standards, respectively. D. The arrangement of the insulated cores of computer cables shall be confirmed according to the corresponding chromatographic method or determined according to the production notification.

7. A method for manufacturing a cross-linked extruded insulated power cable according to claim 1 or 6, characterized in that: In step 8, cable formation is accomplished using multiple molds. (1) The diameter of the first mold is 1.0 to 2.5 mm larger than the diameter of the cable core, serving to close the cable and prevent the fan-shaped cable from flipping over. (2) The diameter of the second mold is 0 to 0.6 mm smaller than the diameter of the cable core, serving as the first compression. (3) If there is a third mold, the diameter is 0 to 0.4 mm smaller than the diameter of the cable, serving as a shaping function. The shorter the distance between the wrapping tape and the wrapping tape mold, the tighter the cable formation.

8. The method for manufacturing a cross-linked extruded insulated power cable according to claim 7, characterized in that: In step 8, the formulas for calculating the outer diameter of the fan-shaped and tile-shaped cables are as follows: 1) D = R × 2, where D represents the outer diameter of the cable and R represents the height of the insulated core; 2) D = Mh (2 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.00), and h represents the height of the fan-shaped section; 3) D = Mh (3 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.11), and h represents the height of the fan-shaped section; 4) D = Mh (4 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.20), and h represents the height of the fan-shaped section; 5) D = Mh (3+1 cores), where D represents the outer diameter of the cable, M represents the empirical coefficient for the outer diameter ratio (taken as 2.31), and h represents the height of the fan-shaped section; 6) D = 2h +d(4+1, 3+2, five-core) where D—represents the outer diameter of the cable, h—represents the thickness of the corrugated shape, and d—represents the diameter of the small circle; 7) D = 2.154 h +d(4+1, 3+2, five-core) where D—represents the outer diameter of the cable, h—represents the thickness of the corrugated shape, and d—represents the diameter of the small circle.

9. A method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 9, the same type of steel strip of the same cable is used. Both layers of steel strip are intermittently wrapped in a right-hand direction. The wrapping is tight and flat. The overlap of the upper and lower layers of steel strip is not less than 25% of the width of the steel strip. The wrapping gap is not greater than 50% of the width of the cable. The steel strip is lap-welded. The joint of the steel strip should be cut at a 45° bevel. The bevel is parallel to the cable axis after wrapping. The overlap at the joint is 3-10mm. If the joint surface is rough, it should be repaired to be flat and firm. There should be no burrs or sharp corners on the joint edge. The steel strip armor wrapping is tight and there should be no gaps. Steel strips with defects such as inclusions, burrs, sand holes, or rust should be removed. The tension of the steel strip wrapping is controlled. The tension is greatest when the coil is full, otherwise the steel strip is easy to fly out. When the coil is half full, it is loosened, otherwise it will damage the cable or cause the steel strip to curl and damage the cable core.

10. A method for manufacturing a cross-linked extruded insulated power cable according to claim 1, characterized in that: In step 10, the diameter of the coil during coiling is determined according to the product specifications and length of the coil, and the outer dimensions of the coil of the same specification and length are kept consistent each time. The coil length is 100m, and the deviation is no more than ±0.5m. The length is measured with a meter counter. Short segments with a length of not less than 10m are allowed to be delivered, and their quantity shall not exceed 10% of the total delivery length. Each short segment shall not exceed 5 segments.

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