400sz intelligent mixed drawing die structure and drawing method

Abstract

This application provides a 400SZ intelligent hybrid wire drawing die structure and drawing method, which includes six wire drawing dies arranged sequentially, with the diameter of each die decreasing sequentially: the diameter of the first die is 6.880mm-6.951mm, the diameter of the second die is 5.650mm-5.715mm, the diameter of the third die is 4.710mm-4.825mm, the diameter of the fourth die is 3.950mm-3.995mm, the diameter of the fifth die is 3.360mm-3.455mm, and the diameter of the sixth die is 2.970mm-3.115mm. This application optimizes the aperture of each die to create a gradual deformation gradient, allowing the metal wire to extend evenly between each pass. This effectively reduces cross-sectional distortion caused by local stress concentration during the stranding process of Z-shaped stranded conductors, thus improving dimensional accuracy. The decreasing aperture of each die balances the work hardening degree of the wire while achieving a high overall compression ratio, facilitating subsequent control of hardness and softness. This solves the problems of poor die matching and difficulty in controlling hardness and softness balance, and has the advantages of improving conductor forming quality, good process stability, reasonable die matching, and ease of promotion and implementation.

Description

Technical Field

[0001] This invention relates to the field of wire and cable manufacturing technology, specifically to a 400SZ intelligent hybrid stranding drawing die structure and drawing method. Background Technology

[0002] In existing technologies, large-section conductor copper stranded wire plays a crucial role in high-voltage and ultra-high-voltage overhead transmission lines. It effectively reduces the skin effect, minimizes line losses, and improves transmission efficiency, especially in long-distance, high-capacity transmission projects. 400mm² conductors are particularly valuable in these applications. 2 The use of large-section conductors (400mm² and above) is increasing year by year, placing higher demands on conductor manufacturing processes and product quality. Among them, Z-type single wires, due to their unique cross-sectional shape, can tightly interlock with adjacent layers of single wires during stranding, forming a higher-density conductor structure, thus significantly improving the conductor's fill factor and conductivity. In a typical 400mm²... 2 In copper split conductors, a multi-layer stranded compression structure of 1+6+12+18+24 is typically used. The outermost layer consists of 24 400SZ single wires (Z-shaped cross-section, effective wire diameter of 2.93mm), and the next outermost layer consists of 18 400S single wires (S-shaped cross-section, also with an effective wire diameter of 2.93mm). This multi-layer, irregularly shaped single wire combination design places extremely high demands on the mold structure and wire drawing process.

[0003] However, in actual production processes, the following technical problems exist regarding the drawing dies and drawing methods for 400SZ single wire: First, the cross-sectional shape is complex, making molding difficult. 400SZ single wire has an irregular Z-shaped cross-section, which is quite different from ordinary round stranded wire. Improper design of existing mold structures can easily lead to distortion of the cross-sectional shape of the single wire during the drawing process, resulting in problems such as irregular edges and excessive local deformation, which seriously affects the quality of the single wire and the subsequent stranding effect.

[0004] Secondly, extremely high dimensional accuracy is required. The effective wire diameter accuracy of 400SZ single wire directly affects the resistivity and stranding effect of the conductor. Deviation in outer diameter will cause the cross-sectional area of ​​the stranded conductor to deviate from the design requirements, thus affecting the conductivity. At the same time, dimensional accuracy is also directly related to the tightness of fit between each layer of single wire, and traditional molds are difficult to simultaneously meet the precise control of multiple key dimensions (such as width, thickness, tooth angle, etc.).

[0005] Third, compatibility with 400S single wire is difficult to guarantee. 400SZ and 400S single wires need to be used in coordination on the same equipment, and their dimensions, hardness, surface quality, and other parameters must be highly consistent to ensure the structural integrity and performance stability of the stranded conductor. Existing processes often process the two types of single wires separately, lacking unified mold parameters and process coordination, which easily leads to problems such as interlayer loosening and uneven cross-sections.

[0006] Fourth, controlling the balance between hardness and softness is difficult. During the wire drawing process, work hardening leads to increased hardness and decreased conductivity, typically requiring online annealing. However, excessively high annealing temperatures cause surface oxidation and discoloration, while excessively low temperatures fail to achieve the desired softening effect. Existing wire drawing dies lack effective means to control frictional heat and deformation heat, further increasing the difficulty of controlling annealing precision and surface quality.

[0007] Therefore, in order to comprehensively improve the forming accuracy, surface quality, mechanical properties, and compatibility with 400S single wire, it is urgent to develop an intelligent hybrid stranding drawing die structure and drawing method specifically for 400SZ single wire. By optimizing the die aperture sequence, compression ratio distribution, cooling and lubrication method, and online annealing coordinated control, high-efficiency and high-quality Z-shaped single wire preparation can be achieved, thereby solving the above-mentioned problems in the existing technology. Summary of the Invention

[0008] To address the technical problems existing in the prior art, the present invention aims to provide a 400SZ intelligent hybrid stranding drawing die structure and a drawing and stranding method. By optimizing the drawing die structure and stranding process parameters, the technical difficulties of Z-shaped cross-section single wire in the drawing process, such as cross-sectional distortion, insufficient dimensional accuracy, poor matching, and difficulty in controlling soft and hard balance, are solved.

[0009] The objective of this invention is achieved through the following technical solution: A 400SZ intelligent hybrid wire drawing die structure, the die structure comprising six wire drawing dies arranged sequentially, the equivalent aperture of each die being as follows: The first mold, 400SZ-1, has an equivalent aperture of 6.880mm to 6.951mm. The second mold, 400SZ-2, has an equivalent aperture of 5.650mm to 5.715mm. The third mold, 400SZ-3, has an equivalent aperture of 4.710mm to 4.825mm. The fourth mold, 400SZ-4, has an equivalent aperture of 3.950mm to 3.995mm. Fifth mold 400SZ-5: equivalent aperture of 3.360mm~3.455mm; The sixth mold, 400SZ-6, has an equivalent aperture of 2.970mm to 3.115mm.

[0010] In some feasible embodiments, the mold structure uses copper wire with a diameter of 7.60mm to 8.10mm as the base wire, and the hole diameter deviation of a single mold is ±0.01mm.

[0011] In some feasible embodiments, the machining accuracy of the mold structure is ±0.01mm, the material of the mold structure is tungsten cobalt cemented carbide YG8, and the surface roughness of the mold structure is Ra0.03μm~Ra0.05μm.

[0012] In some feasible embodiments, the mold structure is used in conjunction with a water blowing mold, wherein the water blowing mold has an inlet diameter of 5.05 mm and an outlet diameter of 5.05 mm, and the water blowing mold is used to deliver airflow to the drawn wire to remove the lubricant from the surface of the wire.

[0013] To address the technical problem presented in this invention, this invention provides a 400SZ intelligent hybrid stranding method, employing the aforementioned 400SZ intelligent hybrid stranding die structure, comprising the following steps: Step 101: Material preparation. Prepare copper wire of the preset size and specifications, check whether the diameter is within the allowable range, and eliminate raw materials with surface cracks, burrs, oxidation defects; Step 102: Wire drawing. The copper wire is drawn through six wire drawing dies in sequence. The dies are kept in the same direction during the wire drawing process, and lubricant is used to ensure sufficient lubrication. Step 103: Wire stranding. Using the LDD-450 / 11-2 type wire drawing and stranding machine, the drawn Z-type single wire, S-type single wire, and round wire are stranded together to form a 400mm strand. 2 The conductor is divided, wherein the effective wire diameter of the 400SZ single wire is 2.92mm~2.94mm; Step 104: Remove residual lubricant from the wire surface using a water blower; Step 105: Online annealing, during which no oxidation or discoloration occurs on the conductor surface; Step 106: Winding up the wire. The finished conductor prepared in step five is wound up onto a reel, with a single reel length of 6600m.

[0014] In some feasible embodiments, the 400mm 2 The split conductor adopts a stranded compressed split conductor with a 1+6+12+18+24 structure. The center layer is a round wire with a diameter of 2.61mm to 2.65mm, the first layer is a round wire with a diameter of 2.61mm to 2.65mm, the second layer is a round wire with a diameter of 2.61mm to 2.65mm, the third layer is a round wire with a diameter of 2.61mm to 2.65mm, the third layer is a round wire with a diameter of 18 400S single wires, and the fourth layer is a round wire with a diameter of 24 400SZ single wires.

[0015] In some feasible embodiments, in step two, the wire drawing speed is 11m / s to 13m / s; in step three, the wire stranding speed is 13m / s to 15m / s; in step six, the take-up air pressure is controlled within the range of 0.2MPa to 0.3MPa, and the spool loading capacity is 6600m.

[0016] In some feasible embodiments, in step five, the annealing voltage is set to 33.53V to ensure that the conductor resistivity is not greater than 0.0171Ω·mm. 2 / m, elongation not less than 35%.

[0017] In some feasible embodiments, the twisting parameters in step three are: Core layer: 1 Φ2.61mm round wire, untwisted; First layer: 6 Φ2.61mm round wires, compaction die hole diameter 7.70±0.10mm, pitch 185mm, right-hand twisted; Second layer: 12 Φ2.61mm round wires, compaction die hole diameter 11.60±0.10mm, pitch 290mm, twisted to the left; Third layer: 18 400S-2.93 type wires, compaction die hole diameter 17.50±0.10mm, pitch 385mm, right-hand twisted; Fourth layer: 24 400Z-2.93 type wires, compaction die hole diameter 22.00±0.10mm, pitch 395mm, left-hand twisted.

[0018] In some feasible embodiments, after step three twisting, the outer diameter of the conductor is 22.00mm~22.10mm, the DC resistance at 20℃ is ≤0.0470Ω / km, and the theoretically calculated weight is 3289.3kg / km.

[0019] In actual implementation, the core of the 400SZ intelligent hybrid wire drawing die structure lies in its die sequence consisting of six sequentially arranged drawing dies. The die hole contour of each die matches the Z-shaped cross-sectional shape of the required 400SZ single wire (i.e., the die hole has a non-circular Z-shaped contour), and the characteristic dimensions of the die hole (such as width, height, and equivalent aperture corresponding to the tooth angle) decrease sequentially according to the set values. When producing 400S single wire, the same aperture sequence and compression ratio allocation are used as for 400SZ single wire, with only the S-shaped and Z-shaped contours of the die holes being mirror images of each other.

[0020] It should be noted that mixed stranding refers to a split conductor structure made of round wire, S-shaped cross-section single wire and Z-shaped cross-section single wire. The tight interlocking of the different shaped wires improves the conductor fill factor and conductivity.

[0021] Effective wire diameter: refers to the equivalent circular diameter of a single wire with a Z-type / S-type cross-section. It is used to characterize the cross-sectional area of ​​a single wire. The calculation method is to divide the cross-sectional area of ​​the single wire by π, take the square root, and then multiply by 2.

[0022] Equivalent aperture: refers to the equivalent circular diameter of a non-circular die hole, used to calculate the compression ratio during the wire drawing process.

[0023] The working principle of this invention is as follows: Step-by-step plastic deformation: Copper wire (original wire) with a diameter of 7.60mm to 8.10mm is passed sequentially through the first to sixth dies. Each die applies compressive force to the wire, causing the metal material to plastically flow along the die hole contour, forming a Z-shaped cross-section with decreasing dimensions step by step. Because the single-pass compression rate is controlled between 15.5% and 25.5%, the deformation is moderate, avoiding local stress concentration, cross-sectional distortion, or internal cracks caused by excessive deformation in a single pass.

[0024] Die Precision and Surface Control: Each die structure is made of tungsten-cobalt cemented carbide YG8, with a machining accuracy of ±0.01mm, and the surface roughness of the die holes is controlled within Ra0.03μm~Ra0.05μm. High precision ensures the consistency of cross-sectional dimensions of the wire after each deformation; low surface roughness reduces frictional resistance during the wire drawing process, reducing the risk of scratches or burrs on the wire surface.

[0025] Working in conjunction with the water-blowing mold: After the sixth mold, a water-blowing mold is installed. The inlet and outlet diameters of the water-blowing mold are both 5.05mm, and it has an internal airflow channel. When the drawn wire passes through the water-blowing mold, external compressed air blows onto the surface of the wire through the airflow channel, blowing away any residual lubricant (drawing oil), preventing lubricant from contaminating subsequent annealing processes, and avoiding localized oxidation or surface spots caused by lubricant residue.

[0026] Synergy with the online annealing unit: The output end of the die sequence is connected to the inlet of the electrode wheel of the online annealing unit. After the wire is formed by the sixth die and the lubricant is blown off, it directly enters the annealing area. The compression ratio distribution of the die ensures that the hardness of the wire when it exits the die is within the appropriate annealing range, which facilitates precise control of the subsequent annealing voltage (e.g., 33.53V), thereby restoring conductivity and elongation under conditions without oxidation and discoloration.

[0027] Compared with the prior art, the present invention has the following beneficial effects: This application provides a 400SZ intelligent hybrid wire drawing die structure and drawing method, which includes six wire drawing dies arranged sequentially, with the diameter of each die decreasing sequentially: the diameter of the first die is 6.880mm-6.951mm, the diameter of the second die is 5.650mm-5.715mm, the diameter of the third die is 4.710mm-4.825mm, the diameter of the fourth die is 3.950mm-3.995mm, the diameter of the fifth die is 3.360mm-3.455mm, and the diameter of the sixth die is 2.970mm-3.115mm. This application optimizes the aperture of each die to create a gradual deformation gradient, allowing the metal wire to extend evenly between each pass. This effectively reduces cross-sectional distortion caused by local stress concentration during the stranding process of Z-shaped stranded conductors, thus improving dimensional accuracy. The decreasing aperture of each die balances the work hardening degree of the wire while achieving a high overall compression ratio, facilitating subsequent control of hardness and softness. This solves the problems of poor die matching and difficulty in controlling hardness and softness balance, and has the advantages of improving conductor forming quality, good process stability, reasonable die matching, and ease of promotion and implementation.

[0028] Specifically, firstly, the systematic mold structure ensures the forming accuracy of S / Z type single wires. The specific equivalent aperture sequence of the wire drawing mold of the present invention is 6.880mm, 5.650mm, 4.710mm, 3.950mm, 3.360mm, and 2.970mm, which meets the forming requirements of S / Z type single wires.

[0029] Secondly, a dedicated annealing voltage ensures that performance specifications meet standards. The annealing voltage is set at 33.53V, precisely matched to the 2.93mm effective wire diameter, ensuring that the product resistivity does not exceed 0.017100Ω・mm. 2 / m, with an elongation of over 35%, achieving a balance between high conductivity and high ductility, meeting the requirements of GB / T3956-2023 standard.

[0030] Third, process synergy with the 400S single-line. The 400SZ and 400S single lines use the exact same aperture sequence and compression ratio allocation, with only the die aperture profile being a mirror image of each other. This ensures that the two single lines can be produced alternately on the same equipment, reducing equipment investment and production costs, while also guaranteeing the dimensional consistency and stranding compatibility of the two single lines.

[0031] Fourth, it significantly improves production efficiency. The wire drawing speed reaches 13m / s, and under precise control of the take-up pressure, it achieves efficient and stable continuous production. The tray capacity can reach 6600m, greatly increasing the production volume per batch and reducing production costs.

[0032] Fifth, ensure product surface quality. Residual lubricant on the wire surface is removed using a water-blowing mold. Combined with mold direction consistency control, this ensures that each wire has a smooth surface, free from defects such as burrs, cracks, and water stains, with a regular Z-shaped cross-section and clear edges.

[0033] Sixth, it enhances the structural stability of the conductor. The mold structure and wire drawing and stranding process of this invention ensure precise matching between 400SZ single wire, 400S single wire, and round wire, together forming a 400mm... 2 The 1+6+12+18+24 structure of copper split conductors has a theoretically calculated weight of 3289.3 kg / km after stranding, and its DC resistance at 20℃ is no greater than 0.0470 Ω / km, which meets the current carrying requirements of large cross-section transmission lines.

[0034] Seventh, it reduces production costs and equipment investment. By unifying the mold parameter sequences of the 400SZ and 400S single lines, co-line production of both types of single lines is achieved on the same equipment, reducing the complexity of mold design and manufacturing, and lowering mold procurement and maintenance costs. Simultaneously, the shortened mold changeover time improves equipment utilization, further reducing the production cost per unit product. Actual production verification shows that adopting this invention effectively improves production efficiency and reduces production costs. Attached Figure Description

[0035] Figure 1 The diagram shows the cross-sectional structure of a 400SZ stranded wire, illustrating the cross-sectional layout of a five-layer stranded structure (1+6+12+18+24). Figure 2 The diagram shows the complete process steps from material preparation to wire winding. Figure 3 The diagram shows the structure and performance indicators of the 400SZ stranded wire, illustrating its structural parameters and product performance. Detailed Implementation

[0036] The following is in conjunction with the appendix Figures 1 to 3 The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0037] Example 1: 400SZ Single-Wire System The LDD-450 / 11-2 type wire drawing and stranding machine was used to prepare 400SZ single wires. The specific steps are as follows: (1) Material preparation: Select copper rod wire with a diameter of 8.00mm, the actual measured diameter is 7.95mm, and the surface is free of defects such as cracks and burrs.

[0038] (2) Die configuration: Configure six Z-type wire drawing dies according to the following equivalent apertures: Water blowing mold configuration: inlet diameter 5.05mm, outlet diameter 5.05mm.

[0039] (3) Wire drawing process parameters: wire drawing speed 13m / s; annealing voltage 33.53V; take-up pressure 0.25MPa.

[0040] (4) Product testing results: Example 2: Preparation of 400S single-wire Using the same equivalent aperture sequence and process parameters as in Example 1, only the Z-type drawing die was replaced with a mirrored S-type drawing die, and the die numbers were adjusted accordingly from 400S-1 to 400S-6. Product testing results: effective wire diameter 2.93mm, good matching between S-type and Z-type cross-sections, resistivity 0.01703Ω・mm. 2 / m, elongation 37%.

[0041] Example 3: Stranding of 400mm² copper conductors Twenty-four 400SZ single wires prepared in Example 1, 18 400S single wires prepared in Example 2, and 19 round wires with a diameter of 2.61 mm were twisted together. The specific twisting parameters are as follows: Performance after stranding: Outer diameter after stranding is 22.00mm~22.10mm, DC resistance at 20℃ is 0.0465Ω / km (not greater than 0.0470Ω / km), unit weight is 3290kg / km (approximately 3289.3kg / km), the roundness of the stranded cross section is good, and the conductors in each layer are tightly arranged without looseness.

[0042] Example 4: Mass Production In actual mass production, using the mold ratio and process parameters from Example 1, 100 reels of 400SZ single-line material were continuously produced. The pass rate criteria were: effective wire diameter deviation ≤ ±0.01mm, no cross-sectional distortion, no surface burrs or oxidation, and resistivity ≤ 0.0171Ω・mm. 2 / m, elongation ≥35%; dimensions were measured using a laser diameter gauge, resistivity was measured using a double-arm bridge, and elongation was measured using a tensile testing machine. The final product qualification rate reached 98.5%. Ten reels of products were randomly selected for testing, and all performance indicators met the technical requirements: the effective wire diameter fluctuated by no more than 0.01mm within the range of 2.92mm to 2.94mm, and the average resistivity was 0.01708Ω・mm. 2 / m, with an average elongation of 36.2% and an average linear density of 59.6 kg / km.

[0043] Compared to production lines using traditional die ratios (traditional die ratios employ 8-pass wire drawing, a total compression rate of 84.5%, a wire drawing speed of 8 m / s, a product qualification rate of 92%, and a die changeover time of 2 hours), this invention effectively improves production efficiency and yield, and significantly reduces production costs. Furthermore, when switching between production lines on the same 400S single line, only the corresponding mirrored wire drawing die needs to be replaced, reducing die changeover time from 2 hours in the traditional method to less than 30 minutes, greatly improving equipment utilization and production flexibility.

[0044] In summary, this application provides a 400SZ intelligent hybrid wire drawing die structure and drawing method, which includes six wire drawing dies arranged sequentially, with the diameter of each die decreasing sequentially: the diameter of the first die is 6.880mm-6.951mm, the diameter of the second die is 5.650mm-5.715mm, the diameter of the third die is 4.710mm-4.825mm, the diameter of the fourth die is 3.950mm-3.995mm, the diameter of the fifth die is 3.360mm-3.455mm, and the diameter of the sixth die is 2.970mm-3.115mm. This application optimizes the aperture of each die to create a gradual deformation gradient, allowing the metal wire to extend evenly between each pass. This effectively reduces cross-sectional distortion caused by local stress concentration during the stranding process of Z-shaped stranded conductors, thus improving dimensional accuracy. The decreasing aperture of each die balances the work hardening degree of the wire while achieving a high overall compression ratio, facilitating subsequent control of hardness and softness. This solves the problems of poor die matching and difficulty in controlling hardness and softness balance, and has the advantages of improving conductor forming quality, good process stability, reasonable die matching, and ease of promotion and implementation.

[0045] The embodiments provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A 400SZ intelligent hybrid stranding drawing die structure, characterized in that, The mold structure includes six wire drawing dies arranged in sequence, and the equivalent aperture of each die is as follows: The first mold, 400SZ-1, has an equivalent aperture of 6.880mm to 6.951mm. The second mold, 400SZ-2, has an equivalent aperture of 5.650mm to 5.715mm. The third mold, 400SZ-3, has an equivalent aperture of 4.710mm to 4.825mm. The fourth mold, 400SZ-4, has an equivalent aperture of 3.950mm to 3.995mm. Fifth mold 400SZ-5: equivalent aperture of 3.360mm~3.455mm; The sixth mold, 400SZ-6, has an equivalent aperture of 2.970mm to 3.115mm.

2. The 400SZ intelligent hybrid stranding die structure according to claim 1, characterized in that, The mold structure uses copper wire with a diameter of 7.60mm to 8.10mm as the base wire, and the hole diameter deviation of a single mold is ±0.01mm.

3. The 400SZ intelligent hybrid stranding die structure according to claim 1, characterized in that, The machining accuracy of the mold structure is ±0.01mm, the material of the mold structure is tungsten cobalt cemented carbide YG8, and the surface roughness of the mold structure is Ra0.03μm~Ra0.05μm.

4. The 400SZ intelligent hybrid stranding die structure according to claim 1, characterized in that, The mold structure is used in conjunction with the water blowing mold. The water blowing mold has an inlet diameter of 5.05mm and an outlet diameter of 5.05mm. The water blowing mold is used to deliver airflow to the drawn wire to remove the lubricant from the surface of the wire.

5. A method for intelligent hybrid stranding and drawing of 400SZ wire, characterized in that, The 400SZ intelligent hybrid strand drawing die structure according to any one of claims 1 to 4 includes the following steps: Step 101: Material preparation. Prepare copper wire of the preset size and specifications, check whether the diameter is within the allowable range, and eliminate raw materials with surface cracks, burrs, oxidation defects; Step 102: Wire drawing. The copper wire is drawn through six wire drawing dies in sequence. The dies are kept in the same direction during the drawing process, and lubricant is used to ensure sufficient lubrication. Step 103: Wire stranding. Using the LDD-450 / 11-2 type wire drawing and stranding machine, the drawn Z-type single wire, S-type single wire, and round wire are stranded together to form a 400mm strand. 2 The conductor is divided, wherein the effective wire diameter of the 400SZ single wire is 2.92mm~2.94mm; Step 104: Remove residual lubricant from the wire surface using a water blower; Step 105: Online annealing, during which no oxidation or discoloration occurs on the conductor surface; Step 106: Winding up the wire. The finished conductor prepared in step 105 is wound up onto a reel, with a single reel length of 6600m.

6. The 400SZ intelligent hybrid stranding method according to claim 5, characterized in that, The 400mm 2 The split conductor adopts a stranded compressed split conductor with a 1+6+12+18+24 structure. The center layer is a round wire with a diameter of 2.61mm to 2.65mm, the first layer is a round wire with a diameter of 2.61mm to 2.65mm, the second layer is a round wire with a diameter of 2.61mm to 2.65mm, the third layer is a round wire with a diameter of 2.61mm to 2.65mm, the third layer is a round wire with a diameter of 18 400S single wires, and the fourth layer is a round wire with a diameter of 24 400SZ single wires.

7. The 400SZ intelligent hybrid stranding method according to claim 5, characterized in that, In step 102, the wire drawing speed is 11m / s to 13m / s; in step 103, the wire stranding speed is 13m / s to 15m / s; in step 106, the take-up air pressure is controlled within the range of 0.2MPa to 0.3MPa, and the spool loading capacity is 6600m.

8. The 400SZ intelligent hybrid stranding method according to claim 5, characterized in that, In step 105, the annealing voltage is set to 33.53V to ensure that the conductor resistivity is not greater than 0.0171Ω·mm. 2 / m, with an elongation of 35%-45%.

9. The 400SZ intelligent hybrid stranding method according to claim 6, characterized in that, The twisting parameters in step 103 are: Core layer: 1 Φ2.61mm round wire, untwisted; First layer: 6 Φ2.61mm round wires, compaction die hole diameter 7.70±0.10mm, pitch 185mm, right-hand twisted; Second layer: 12 Φ2.61mm round wires, compaction die hole diameter 11.60±0.10mm, pitch 290mm, twisted to the left; Third layer: 18 400S-2.93 type wires, compaction die hole diameter 17.50±0.10mm, pitch 385mm, right-hand twisted; Fourth layer: 24 400Z-2.93 type wires, compaction die hole diameter 22.00±0.10mm, pitch 395mm, left-hand twisted.

10. The 400SZ intelligent hybrid stranding method according to claim 6, characterized in that... After stranding in step 103, the outer diameter of the conductor is 22.00mm~22.10mm, the DC resistance at 20℃ is ≤0.0470Ω / km, and the theoretical weight is 3289.3kg / km.

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