Cable core structure, cable structure and manufacturing process

Abstract

The invention discloses a cable core structure, a cable structure and a manufacturing process, the cable core structure comprises a middle core wire, the periphery of the middle core wire is sequentially wrapped with a plurality of core wire layers, each core wire layer is formed by twisting a plurality of core wires, and the middle core wire and the core wires in each core wire layer adopt polyimide enameled copper wires; every two adjacent core wire layers are isolated through an insulating water-blocking tape, and the outermost core wire layer is wrapped by a wrapping tape. According to the invention, the energy transmission capability and the current-carrying capacity of the cable are obviously enhanced; an insulating water-blocking tape segmentation technology is introduced into the cable core design, so that the production process is simplified, the skin effect is effectively relieved, and the alternating-current resistance of the cable is reduced; polyimide with excellent heat resistance, solvent resistance, refrigerant resistance and high insulating property and copper with lower density and lower cost are adopted as the core wire core material of the cable, so that the manufacturing and mounting cost of the cable is reduced, and the production process is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a cable core structure, a cable structure and a manufacturing process. Background Art

[0002] The cable manufacturing process mainly includes drawing, twisting, pressing, and coating. These processes are interrelated and together constitute the core process of cable production. Starting from the conductor, each process is superimposed layer by layer. The more complex the cable structure, the more layers are superimposed. There are many types of production processes and large material flow: it involves multiple fields such as chemical industry and metal processing, and the material flow is large, which requires reasonable layout and dynamic management. Many special equipment: wire and cable manufacturing uses special production equipment with the process characteristics of this industry, such as extruder series, wire drawing machine series, wire twisting machine series, wrapping machine series, etc.

[0003] In summary, the cable manufacturing process is a complex and delicate process that requires strict control of the quality and process parameters of each link to ensure that the performance and quality of the final product meet the requirements. In the production process of traditional cables, not only do they need to be split, but they also need to go through three processes: first twisting into strands, pressing, and then twisting the strands. Therefore, the production efficiency of traditional cables is low, resulting in high production costs. In addition, the cross-section of 800mm 2 The above cable conductors must use split conductors to reduce the influence of the "skin effect" and "proximity effect" on the transmission energy caused by the increase of the cable conductor resistance. For cables with larger cross-sectional areas, the current carrying capacity and transmission efficiency are lower, and there is a larger AC resistance. At the same time, the overall mechanical structure and compressive performance of the cable are poor. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a cable core structure, a cable structure and a manufacturing process, which can simplify the production process of the cable. At the same time, the significant improvement of the cable core cross-section significantly enhances the energy transmission capacity and current carrying capacity of the cable, meets the needs of higher-specification power transmission, and improves the practicability and reliability of the cable.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect of the present invention, a cable core structure is provided, comprising an intermediate core wire, wherein the outer circumference of the intermediate core wire is sequentially wrapped with multiple core wire layers, each core wire layer being formed by twisting multiple core wires, the intermediate core wire and the core wires in each core wire layer are all made of polyimide enameled copper wires; two adjacent core wire layers are isolated by an insulating water-blocking tape, and the outermost core wire layer is wrapped by a wrapping tape.

[0007] In some embodiments of the present invention, the cross-sectional area of ​​the cable core is 4000-5000mm 2 .

[0008] In some embodiments of the present invention, the diameter of the core wire is 1.5-2.0 mm.

[0009] In some embodiments of the present invention, the polyimide enameled copper wire has an enameled layer with a single-side thickness of 0.02-0.05 mm and a DC resistivity of ≤0.01710Ω*mm at 20°C. 2 / m polyimide enameled wire with copper as the core.

[0010] In some embodiments of the present invention, the insulating water-blocking tape is a double-sided non-conductive water-blocking tape, and the thickness of the double-sided non-conductive water-blocking tape is 0.1-0.3 mm.

[0011] In some embodiments of the present invention, the twisting pitch of each core wire layer of the multiple core wire layers is different, and the twisting pitch increases from the inside to the outside.

[0012] In a second aspect of the present invention, a cable structure is provided, comprising the cable core structure of the first aspect, wherein a conductor shielding layer, an insulating layer, an insulating shielding layer, a water-blocking tape layer, an aluminum alloy layer, a hot-melt adhesive layer, an outer sheath layer and an outer electrode layer are sequentially arranged outside the outermost wrapping tape of the cable core structure.

[0013] In a third aspect of the present invention, a manufacturing process for a cable core structure is provided, comprising: selecting a polyimide enameled wire of suitable radius and single-sided thickness of enameled layer according to the required cross-sectional area of ​​the cable core structure, selecting a double-sided non-conductive water-resistant tape of suitable thickness, and determining the number of core wire layers and the number of core wires in each core wire layer;

[0014] Each core wire layer is twisted in turn from the inside to the outside according to the set twisting pitch. After each core wire layer is twisted, except for the outermost core wire layer, it is longitudinally wrapped with a double-sided non-conductive water-resistant tape, and the outermost core wire layer is longitudinally wrapped with a wrapping tape to obtain the cable core.

[0015] In some embodiments of the present invention, before each core wire layer is twisted, the single core wires are rotated counterclockwise for pre-twisting, thereby initially forming an arrangement.

[0016] In some embodiments of the present invention, after the cable core is obtained, the cable core is subjected to a compacting process.

[0017] One or more technical solutions of the present invention have the following beneficial effects:

[0018] (1) The cable core structure provided by the present invention adopts a new type of enameled wire divided by a water-blocking tape to achieve efficient twisting and process optimization. By designing the cable conductor as a polyimide enameled wire conductor divided by an insulating water-blocking tape, the loss heat generation and skin effect of the conductor are effectively reduced, the current carrying capacity of the conductor is increased, the AC resistance of the cable is reduced, and the sheath loss of the cable is reduced, thereby significantly improving the practicality and reliability of the cable.

[0019] (2) The cable core structure provided by the present invention adopts polyimide with excellent heat resistance, solvent resistance, refrigerant resistance and high insulation performance, and copper with lower density and more economical cost as the core wire core material of the cable, which reduces the manufacturing and installation costs of the cable and simplifies the production process; using enameled wire as the wire core, only two processes of twisting and pressing are required, and no segmentation is required, while traditional cables not only need to be segmented, but also need to go through three processes of first twisting into strands, pressing, and then twisting the strands. In this way, the cable of the present invention can greatly save production time and production costs. In addition, the use of insulating water-blocking tape to wrap and split only requires winding, and can improve the mechanical strength of the cable, so that the cable core has a better compression resistance effect.

[0020] (3) The cable core structure provided by the present invention and the polyimide enameled wire conductor separated by the insulating water-blocking tape have a significant effect on reducing the influence of the skin effect. The skin effect refers to the phenomenon that the current is concentrated near the surface of the conductor under the action of the alternating electric field. It enhances the transmission efficiency of the cable, reduces the sheath loss of the cable, and improves the overall performance of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing the core structure of the enameled wire conductor cable in Example 1;

[0022] Figure 2 This is a structural diagram of the enameled wire conductor cable in Example 2;

[0023] Figure 3 For ordinary 3500mm 2 Current density distribution diagram of five-section corrugated cable core;

[0024] Figure 4 For the normal 4500mm 2 Current density distribution diagram of five-section corrugated cable core;

[0025] Figure 5 4500mm of the present invention 2 Current density distribution diagram of enameled cable core;

[0026] Figure 6 Normal 3500mm 2 Magnetic flux density distribution diagram of five-section corrugated cable core;

[0027] Figure 7 For the normal 4500mm 2 Magnetic flux density distribution diagram of five-section corrugated cable core;

[0028] Figure 8 4500mm of the present invention 2 Magnetic flux density distribution diagram of enameled cable core;

[0029] Fig. 9 For the normal 3500mm 2 Corrugated cable, ordinary 4500mm 2 Corrugated cable, 4500mm of the present invention 2 Comparison chart of current carrying capacity of enameled wire cables;

[0030] Fig.10 For the normal 3500mm 2 Corrugated cable, ordinary 4500mm 2 Corrugated cable, 4500mm of the present invention 2 Comparison chart of AC resistance of enameled wire cables;

[0031] Fig.11 For the normal 3500mm 2 Corrugated cable, ordinary 4500mm 2 Corrugated cable, 4500mm of the present invention 2 Phase loss comparison chart of enameled wire cable;

[0032] Fig.12 For the normal 3500mm 2 Corrugated cable, ordinary 4500mm 2 Corrugated cable, 4500mm of the present invention 2 Comparison chart of enameled wire cable sheath loss.

[0033] In the figure: 1. Copper wire; 2. Polyimide paint; 3. Insulating water-blocking tape; 4. Wrapping tape; 5. Conductor shielding layer; 6. Insulating layer; 7. Insulating shielding layer; 8. Water-blocking tape layer; 9. Aluminum alloy layer; 10. Hot-melt adhesive layer; 11. Outer sheath layer; 12. Outer electrode layer. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] Example 1

[0036] In a typical embodiment of the present invention, a cable core structure is proposed, such as Figure 1As shown, it includes an intermediate core wire, the outer circumference of which is wrapped with multiple core wire layers in sequence, each core wire layer is formed by twisting multiple core wires, the intermediate core wire and the core wires in each core wire layer are all made of polyimide paint 2 wrapped copper wire 1; the two adjacent core wire layers are isolated by an insulating water-blocking tape 3, and the outermost core wire layer is wrapped by a wrapping tape.

[0037] In this embodiment, the cross-sectional area of ​​the cable core is 4000-5000mm 2 Preferably, the cross-sectional area of ​​the cable core is 4500mm 2 .

[0038] In this embodiment, the diameter of the core wire is 1.5-2.0 mm, and preferably, the diameter of the core wire is 1.8 mm.

[0039] In this embodiment, the polyimide enameled copper wire has an enameled layer with a single-side thickness of 0.02-0.05 mm and a DC resistivity of ≤0.01710Ω*mm at 20°C. 2 / m polyimide enameled wire with copper as the core, preferably, the single-side thickness of the enameled layer is 0.03mm.

[0040] In this embodiment, the insulating water-blocking tape is a double-sided non-conductive water-blocking tape, and the thickness of the double-sided non-conductive water-blocking tape is 0.1-0.3 mm. Preferably, the thickness of the double-sided non-conductive water-blocking tape is 0.2 mm.

[0041] In this embodiment, the twisting pitch of each core wire layer of the multiple core wire layers is different, and the twisting pitch increases from the inside to the outside.

[0042] The cable core structure provided in this embodiment innovatively introduces the insulating water-blocking tape segmentation technology in the cable core design. This technology uses the insulating water-blocking tape to finely segment the conductor, which not only simplifies the production process (reducing the segmentation steps in traditional cable manufacturing), but also effectively alleviates the skin effect, reduces the AC resistance of the cable, and improves the transmission efficiency. At the same time, the wrapping of the insulating water-blocking tape enhances the mechanical strength and compressive resistance of the cable.

[0043] In addition, polyimide enameled copper wire is used as the core wire material of the cable. Polyimide is a high-performance insulating material with excellent heat resistance, solvent resistance, refrigerant resistance and high insulation performance. Its long-term use temperature can reach above 220°C, and it has excellent mechanical properties and high chemical stability. In addition, copper material as the wire core has lower density and more economical cost than copper material, which helps to reduce the manufacturing and installation costs of the cable.

[0044] 4500mm 2 For example, the enameled cable is 3500mm 2Corrugated cable, ordinary 4500mm 2 Corrugated cable and 4500mm in this example 2 Enameled wire cable is compared with:

[0045] The obtained cable core current density distribution diagram is as follows: Figure 3-5 As shown, the 4500mm in this embodiment 2 The current density of the enameled wire cable divided by the water-blocking tape is 1.06×10 6 A / m 2 , normal 3500mm 2 The current density of the five-section corrugated cable is 1.22×10 6 A / m 2 The new cable current density is reduced by 160000A / m 2 , reduced by 13.11%. Normal 4500mm 2 The current density of the five-section corrugated cable is 1.15×10 6 A / m 2 , 4500mm in this embodiment 2 The current density of the enameled wire cable divided by water-blocking tape is reduced by 90000A / m 2 , which is reduced by 7.83%. This means that the 4500mm 2 The skin effect of the water-blocking tape-divided enameled wire cable has been significantly reduced, the current density of the cable core has also been reduced, and the current distribution in the conductor has become more uniform.

[0046] The obtained cable core magnetic flux density distribution diagram is as follows: Figure 6-8 As shown, 3500mm 2 The core magnetic flux density of the five-section corrugated cable is 1.18×10 -4 T-0.0134T, 4500mm 2 The core magnetic flux density of the five-section corrugated cable is 2.15×10 - 5 T-0.0128T. In this embodiment, 4500mm 2 The situation of the enameled wire cable divided by the water-blocking tape has changed significantly, and the magnetic flux density of the wire core has decreased to 3.55×10 -5 T-0.0104T. The magnetic field inside the cable core is more uniform.

[0047] Current carrying capacity comparison chart Fig. 9 As shown in the figure, the AC resistance comparison chart is as follows Fig.10 As shown in the figure, the phase loss comparison is as follows Fig.11 As shown in the figure, the sheath loss comparison is as follows Fig.12 The data comparison table of current carrying capacity, AC resistance, phase loss and sheath is shown in Table 1:

[0048] Table 1 Comparison of current carrying capacity, AC resistance, phase loss and sheath loss data

[0049]

[0050] Through data comparison, it can be found that the new 4500mm 2 The current carrying capacity of the water-blocking tape-split enameled wire cable is 2070A, and the ordinary 3500mm 2 The current carrying capacity of the five-section corrugated cable is 2000A, and the current carrying capacity of the new cable has increased by 70A, an increase of 3.5%. 2 Five-section corrugated cable, current carrying capacity is reduced. 4500mm 2 The current carrying capacity of the five-section corrugated cable is 2120A, which is reduced by 2.36%.

[0051] In terms of AC resistance, the new 4500mm 2 The AC resistance of the water-blocking tape-split enameled wire cable is 0.013019Ω / km, and the ordinary 3500mm 2 The AC resistance of the five-section corrugated cable is 0.013563Ω / km, and the AC resistance of the new cable is reduced by 0.000544Ω / km, a decrease of 4%. However, compared with the 4500mm 2 Five-section corrugated cable, AC resistance increased. 4500mm 2 The AC resistance of the five-section corrugated cable is 0.011942Ω / km, which is an increase of 9%.

[0052] In terms of phase loss, the new 4500mm 2 The phase loss of the water-blocking tape-divided enameled wire cable is 30.407W / m, and the ordinary 3500mm 2 The phase loss of the five-section corrugated cable is 29.641W / m, and the phase loss of the new cable is only increased by 0.766W / m, an increase of 2.58%; the ordinary 4500mm 2 The phase loss of the five-section corrugated cable is 29.437W / m, and the phase loss of the new cable has only increased by 0.97W / m, an increase of 3.3%; however, in terms of sheath loss, the new 4500mm 2 The sheath loss of the water-blocking tape-divided enameled wire cable is 79.157W / m, and the ordinary 3500mm 2 The sheath loss of the five-section corrugated cable is 79.783W / m, and the sheath loss of the new cable is reduced by 0.626W / m, a decrease of 0.78%. 2The sheath loss of the five-section corrugated cable is 84.681 W / m, and the sheath loss of the new cable is reduced by 5.524 W / m, a reduction of 6.5%.

[0053] Through the implementation of the above technical solutions, the present invention not only improves the current carrying capacity and transmission efficiency of the cable, but also reduces the AC resistance and sheath loss of the cable, and enhances the mechanical strength and compressive performance of the cable. These improvements make the cable more practical and reliable in the field of power transmission, and improve the comprehensive performance of the cable.

[0054] Example 2

[0055] A cable structure in a typical embodiment 2 of the present invention, such as Figure 2 As shown, it includes the cable core structure of Example 1, and a conductor shielding layer 5, an insulating layer 6, an insulating shielding layer 7, a water-blocking tape layer 8, an aluminum alloy layer 9, a hot-melt adhesive layer 10, an outer sheath layer 11 and an outer electrode layer 12 are sequentially arranged outside the outermost wrapping tape 4 of the cable core structure.

[0056] Example 3

[0057] In a typical embodiment of the present invention, a manufacturing process of a cable core structure is provided, comprising:

[0058] According to the required cross-sectional area of ​​the cable core structure, select the polyimide enameled wire with the appropriate radius and single-sided thickness of the enameled layer, select the double-sided non-conductive water-resistant tape with the appropriate thickness, and determine the number of core wire layers and the number of core wires in each core wire layer;

[0059] Each core wire layer is twisted in turn from the inside to the outside according to the set twisting pitch. After each core wire layer is twisted, except for the outermost core wire layer, it is longitudinally wrapped with a double-sided non-conductive water-resistant tape, and the outermost core wire layer is longitudinally wrapped with a wrapping tape to obtain the cable core.

[0060] Furthermore, before each core wire layer is twisted, the single core wire is rotated in a counterclockwise direction for pre-twisting, thereby initially forming an arrangement.

[0061] Furthermore, after obtaining the cable core, the cable core is subjected to a compacting process.

[0062] Further: When the production cross-sectional area is 4500mm 2 When preparing cable core wires, prepare 271 wires with a radius of 1.8 mm, a single-sided enamel layer thickness of 0.03 mm, and a DC resistivity of ≤0.01710Ω*mm at 20°C. 2 / m polyimide enameled wire with copper as the core;

[0063] Each layer of core wires is twisted from the inside to the outside according to the set twisting pitch. After each layer of core wires is twisted, all core wires except the outermost layer are longitudinally wrapped with a 0.20mm thick double-sided non-conductive water-resistant tape. The outermost core wire layer is longitudinally wrapped with a wrapping tape.

[0064] After twisting, the wire core is pressed tightly.

[0065] In order to ensure the compactness and roundness of the twisted wire core, it needs to be pressed. This step can be completed by mechanical devices. The wire core is a compact round shape, and the twisting should be uniform, round, and tight, without loose strands, missing strands, back strands, or broken strands.

[0066] There are also specific quality requirements for the stranded conductive wire core. For example, the stranded wire core should be tight, round, straight, without severe bends, strand skipping, scratches, or flattening. The copper wire surface should not be oxidized, blackened, the tinned wire layer should not fall off, or there should be tin particles. The pitch should be uniform, the joints should be flat and firm, and the wires should be neatly arranged.

[0067] The twisting must be uniform and tight, without loose strands, missing strands, back strands, broken strands, and without defects such as oil stains, burrs, sharp edges, scratches and protrusions.

[0068] Furthermore, the first layer is twisted with 6 polyimide enameled wires of radius 1.8 mm and a twisting pitch of 100 mm;

[0069] The second layer is twisted with 12 polyimide enameled wires with a radius of 1.8mm and a twist pitch of 150mm;

[0070] The third layer is twisted with 18 polyimide enameled wires with a radius of 1.8 mm and a twist pitch of 260 mm;

[0071] The fourth layer is twisted with 24 polyimide enameled wires with a radius of 1.8 mm and a twist pitch of 320 mm;

[0072] The fifth layer is twisted with 30 polyimide enameled wires with a radius of 1.8 mm and a twist pitch of 400 mm;

[0073] The sixth layer is twisted with 36 polyimide enameled wires with a radius of 1.8 mm and a twist pitch of 470 mm;

[0074] The seventh layer is twisted with 42 polyimide enameled wires with a radius of 1.8 mm and a twist pitch of 520 mm;

[0075] The eighth layer is twisted with 48 polyimide enameled wires with a radius of 1.8 mm and a twist pitch of 600 mm;

[0076] The ninth layer is twisted with 54 polyimide enameled wires with a radius of 1.8 mm and a twisting pitch of 660 mm.

[0077] The use of polyimide enameled copper wire as the core greatly simplifies the production process of the cable. Traditional cable manufacturing requires multiple steps such as splitting, twisting, and pressing, while the cable core of the present invention only needs to go through two processes, twisting and pressing, and no additional splitting step is required, thereby significantly reducing production costs and production time.

[0078] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A cable core structure, characterized in that: It comprises an intermediate core wire, the outer circumference of which is sequentially wrapped with multiple core wire layers, each core wire layer being formed by twisting multiple core wires, the intermediate core wire and the core wires in each core wire layer are all made of polyimide enameled copper wires; two adjacent core wire layers are isolated by an insulating water-blocking tape, and the outermost core wire layer is wrapped by a wrapping tape.

2. The cable core structure according to claim 1, characterized in that: The cross-sectional area of ​​the cable core is 4000-5000mm 2 .

3. The cable core structure according to claim 1, characterized in that: The diameter of the core wire is 1.5-2.0 mm.

4. The cable core structure according to claim 1, characterized in that: The polyimide enameled copper wire has an enameled layer with a single-side thickness of 0.02-0.05 mm and a DC resistivity of ≤0.01710Ω*mm at 20°C. 2 / m polyimide enameled wire with copper as the core.

5. The cable core structure according to claim 1, characterized in that: The insulating water-blocking tape is a double-sided non-conductive water-blocking tape, and the thickness of the double-sided non-conductive water-blocking tape is 0.1-0.3 mm.

6. The cable core structure according to claim 1, characterized in that: The twisting pitch of each core wire layer of the multi-layer core wire layer is different, and the twisting pitch increases from the inside to the outside.

7. A cable structure, comprising the cable core structure according to any one of claims 1 to 6, characterized in that: The outermost wrapping tape of the cable core structure is sequentially provided with a conductor shielding layer, an insulating layer, an insulating shielding layer, a water-blocking tape layer, an aluminum alloy layer, a hot-melt adhesive layer, an outer sheath layer and an outer electrode layer.

8. A process for manufacturing a cable core structure according to any one of claims 1 to 6, characterized in that: include: According to the required cross-sectional area of ​​the cable core structure, select the polyimide enameled wire with the appropriate radius and single-sided thickness of the enameled layer, select the double-sided non-conductive water-resistant tape with the appropriate thickness, and determine the number of core wire layers and the number of core wires in each core wire layer; Each core wire layer is twisted in turn from the inside to the outside according to the set twisting pitch. After each core wire layer is twisted, except for the outermost core wire layer, it is longitudinally wrapped with a double-sided non-conductive water-resistant tape, and the outermost core wire layer is longitudinally wrapped with a wrapping tape to obtain the cable core.

9. The manufacturing process of the cable core structure according to claim 8, characterized in that: Before each layer of core wires is twisted, the single core wires are pre-twisted by rotating them counterclockwise to form a preliminary arrangement.

10. The manufacturing process of the cable core structure according to claim 9, characterized in that: After obtaining the cable core, the cable core is pressed tightly.

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