Process for the production of a cable and cable

Abstract

The embodiment of the present application relates to the technical field of cables, and relates to a cable preparation method and a cable.The cable preparation method comprises the following steps: copper and aluminum are heated to a molten state respectively to obtain a copper melt and an aluminum melt; the copper melt and the aluminum melt are injected into the same mold through independent flow channels respectively, so that the copper melt and the aluminum melt form an inner and outer layer distribution structure of a copper cladding layer cladding an aluminum core layer in the mold; the copper melt and the aluminum melt are heat preserved, so that a metallurgical bonding layer is formed at the interface; and the center conductor is prepared by cooling through a cooling system.The cable preparation method can make copper and aluminum reach a completely molten state or an approximate molten state respectively, so that copper and aluminum are both involved in high-temperature molten-state compounding, a continuous and uniform metallurgical bonding layer is formed at the copper-aluminum interface, the bonding strength is improved, and the problems of easy delamination and unstable structure in the subsequent process are avoided.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and more specifically, to a method for manufacturing a cable and the cable itself. Background Technology

[0002] With the popularization of new energy vehicles and the deepening of the trends of lightweighting and intelligence, in-vehicle wiring is becoming increasingly narrow and convoluted. The copper busbar conductor structure used in traditional cables is costly and heavy, while the conductor structure of pure aluminum busbar has low conductivity and is prone to oxidation and heat generation. Therefore, the industry has proposed copper-clad aluminum busbars to improve the above problems. However, although the current copper-clad aluminum busbar structure takes into account the advantages of cost and weight reduction, it still has serious technical defects: for example, the copper-aluminum interface of the conductor structure, which is made by concentrically covering the aluminum core with copper strip of equal thickness and drawing process, is only mechanically wrapped. Due to the difference in thermal expansion coefficient, the cable formed by the conductor structure is prone to delamination and gaps after bending, which leads to a decrease in the conductivity of the cable and seriously affects the reliability and service life of the product.

[0003] Therefore, how to provide a structurally stable conductor structure has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for manufacturing a cable and a cable that can solve the problem of insufficient reliability of the interlayer interface bonding of the central conductor.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: This invention provides a method for preparing a cable, comprising the following steps: heating copper and aluminum to a molten state to obtain copper melt and aluminum melt respectively; injecting the copper melt and aluminum melt into the same mold through independent flow channels, so that the copper melt and aluminum melt form an inner and outer layer distribution structure of copper cladding layer covering aluminum core layer in the mold; keeping the copper melt and aluminum melt at a constant temperature, so that the copper melt and aluminum melt form a metallurgical bonding layer at the interface; and cooling through a cooling system to obtain the center conductor.

[0006] Furthermore, the cable manufacturing method also includes the following steps: coating the outer surface of the central conductor with a primer layer; wrapping a fire-resistant layer on the outer surface of the primer layer; winding a protective layer on the outer surface of the fire-resistant layer; and extruding an insulation layer on the outer surface of the protective layer, wherein the insulation layer is cooled and shaped after extrusion to obtain the cable.

[0007] Furthermore, the step of wrapping a refractory layer on the outer surface of the primer layer includes: overlapping and wrapping the wrapping tape around the outer surface of the primer layer to form a refractory layer; wherein the overlap width between adjacent wrapping tape loops is 40%-50% of the width of the wrapping tape, and the wrapping angle of the wrapping tape is 45°-60°.

[0008] Furthermore, during the process of overlapping and wrapping the wrapping tape around the outer surface of the base coating, hot air drying at 90℃-110℃ is used for shaping.

[0009] Furthermore, before wrapping the wrapping tape over the outer surface of the base coating, the method further includes drying the wrapping tape with hot air at a constant temperature of 75℃-95℃ for a first preset time, wherein the first preset time is 12h-20h.

[0010] Furthermore, the cooling and shaping process in the extrusion of the insulating layer on the outer surface of the protective layer is a three-stage cooling process. The first stage has a cooling temperature of 40℃-50℃, the second stage has a cooling temperature of 25℃-30℃, and the third stage uses natural cooling.

[0011] Furthermore, the cable manufacturing method also includes: heating the area of ​​the cable to be bent at a first preset temperature for a second preset time; placing the heated area to be bent in a bending device and driving the bending device to bend the area to be bent; and heat-insulating the bent area to be bent after bending to set its shape; wherein the first preset temperature is 80℃-100℃ and the second preset time is 5min-10min.

[0012] This invention also provides a cable, comprising: a center conductor, which is prepared using the cable preparation method provided in the above embodiments.

[0013] Furthermore, the cable also includes: a base coating layer, which is wrapped around the outer surface of the central conductor; a fire-resistant layer, which is wrapped around the outer surface of the base coating layer; a protective layer, which is wrapped around the outer surface of the fire-resistant layer, and the protective layer includes a hot melt adhesive layer and an inner lining layer, with the hot melt adhesive layer bonded between the fire-resistant layer and the inner lining layer; and an insulation layer, which is wrapped around the outer surface of the protective layer.

[0014] Furthermore, the refractory layer is a wrapping tape that overlaps and wraps around the outside of the base layer; the thickness of the wrapping tape is h2, and 0.12mm≤h2≤0.14mm; the overlap width between adjacent wrapping tape loops is 40%-50% of the width of the wrapping tape, and the wrapping angle of the wrapping tape is 45°-60°.

[0015] The beneficial effects of this invention are: The cable manufacturing method proposed in this invention involves melting copper and aluminum separately until both metals reach a molten state. This dual-molten composite process, in which both metals participate in high-temperature molten composite, allows for high-temperature interdiffusion at the interface between the copper melt and the aluminum melt, forming a continuous and uniform metallurgical bonding layer with high bonding strength. This solves the problems of insufficient cross-sectional diffusion and easy delamination in existing copper-clad aluminum busbar composite conductors. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below.

[0017] Figure 1 This is a schematic flowchart illustrating a method for preparing a cable according to an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of a cable according to an embodiment of the present invention; Figure 3 This is a schematic flowchart illustrating a method for preparing a cable according to an embodiment of the present invention; Figure 4 This is a schematic flowchart illustrating a cable bending method according to an embodiment of the present invention.

[0018] Figure label: 100. Cable; 1. Center conductor; 2. Primer coating; 3. Fire-resistant layer; 4. Protective layer; 5. Insulation layer. Detailed Implementation

[0019] In the description of this invention, it should be noted that the terms "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0020] The technical solutions of the present invention will now be described with reference to the accompanying drawings in the embodiments of the present invention.

[0021] See Figure 1 This invention provides a method for preparing a cable and a cable 100.

[0022] The method for manufacturing this cable includes the following steps: Step S110: Heat copper and aluminum to a molten state to obtain copper melt and aluminum melt respectively.

[0023] In one embodiment, the molten state may include a fully molten state or a near-molten state.

[0024] It should be noted that the fully molten state refers to the copper or aluminum having completely transformed into a liquid state, forming a copper melt or aluminum melt with good fluidity; the near-molten state refers to the copper or aluminum having reached a semi-molten or semi-solid state, which refers to the temperature range in which the solid and liquid phases coexist. For pure copper, the temperature range in which it reaches the near-molten state is usually 900℃-1000℃, while for pure aluminum, the temperature range in which it reaches the near-molten state is usually 580℃-650℃.

[0025] Step S120: The copper melt and aluminum melt are injected into the same mold through independent flow channels, so that the copper melt and aluminum melt form an inner and outer layer distribution structure in the mold where the copper cladding layer covers the aluminum core layer.

[0026] In step S120 above, copper melt and aluminum melt can be injected into the mold through the central guide tube.

[0027] In one embodiment, the mold has a connected cladding layer channel and a core layer channel. Molten copper is injected into the cladding layer channel, and molten aluminum is injected into the core layer channel, which facilitates the subsequent formation of a structure in which the copper cladding layer covers the aluminum core layer.

[0028] Step S130: Insulate the copper melt and aluminum melt to form a metallurgical bonding layer at the interface.

[0029] Step S140: Cool the conductor 1 using a cooling system to obtain the center conductor 1.

[0030] In step S140 above, in one embodiment, a water-cooling channel may be provided on the outside of the mold. A water-cooling system is connected to the water-cooling channel and a refrigerant is introduced into the water-cooling channel. The cooling intensity of the refrigerant in the water-cooling channel is controlled by the cooling system so that the structure of the copper cladding layer covering the aluminum core layer is cooled and solidified to form the central conductor.

[0031] In this embodiment of the invention, copper and aluminum are heated to a molten state, allowing both metals to participate in high-temperature molten composite to obtain copper melt and aluminum melt. By injecting them into the same mold and performing a heat preservation treatment, the copper melt and aluminum melt form an inner and outer layer distribution structure with a copper cladding layer covering an aluminum core layer. At the interface between the two melts, high-temperature mutual diffusion forms a metallurgical bonding layer, thereby improving the bonding strength between the inner and outer layers of the central conductor 1 and avoiding the defect of easy delamination of mechanical wrapping.

[0032] Meanwhile, the central conductor 1 provided in this embodiment of the invention can also avoid problems such as interlayer bulging and delamination of copper and aluminum layers during the bending process of forming the cable 100 structure.

[0033] See Figures 2-3In one embodiment, the method for manufacturing the cable further includes the following steps: Step S210: Apply a base coating 2 to the outer surface of the center conductor 1.

[0034] Before step S210, the surface of the center conductor 1 needs to be degreased, dusted, and preheated. Then, the base coating 2 is applied to remove dust and oil between the center conductor 1 and the base coating 2, thereby improving the bonding strength between the center conductor 1 and the base coating 2.

[0035] Step S220: Wrap the refractory layer 3 around the outer surface of the base coating 2.

[0036] In one embodiment, the refractory layer 3 may be a wrapping tape that overlaps and wraps around the outside of the base layer 2.

[0037] In step S220 above, an overlapping wrapping tape is used, with the overlap width between adjacent wrapping tape loops being 40%-50% of the wrapping tape width, and the wrapping angle being 45°-60°. This embodiment of the invention controls the overlap width between adjacent wrapping tape loops and the wrapping angle within the above ranges, thereby improving the tightness of the wrapping tape's fit.

[0038] During the process of overlapping and wrapping the wrapping tape around the outer surface of the base coating 2, it is also necessary to use hot air drying at 90℃-110℃ to remove moisture and trapped air, prevent bubbling, and thus improve structural stability.

[0039] Before step S220 above, the wrapping tape needs to be dried with hot air at 75℃-95℃ for a first preset time, where the first preset time is 12h-20h, and the moisture content is controlled to be ≤0.3%.

[0040] Step S230: Wrap a protective layer 4 around the outer surface of the fire-resistant layer 3.

[0041] In one embodiment, the protective layer 4 may include a hot melt adhesive layer and an inner lining layer. The hot melt adhesive layer bonds the fire-resistant layer 3 and the inner lining layer, preventing moisture and humidity from entering the cable 100 and improving the interlayer bonding strength of the cable 100.

[0042] Step S240: An insulating layer 5 is extruded onto the outer surface of the protective layer 4, wherein the insulating layer 5 is cooled and shaped after extrusion to obtain the cable 100.

[0043] In one embodiment, the insulating layer 5 may be made of modified polydodecanoic acid.

[0044] Before step S240 above, the modified polydodecanoic acid is dried at a temperature of 120℃-130℃ for 4-4.5 hours to remove moisture from the modified polydodecanoic acid and ensure that the moisture content of the polydodecanoic acid particles is ≤0.05% to prevent hydrolysis and degradation at high temperatures, thus enabling the extrusion process.

[0045] The dried polydodecylamide granules are fed into the extruder and metered into the screw barrel via a feeder. The screw of the extruder rotates inside the barrel, conveying the polydodecylamide granules. With the help of precise stepped temperature control provided by the external heating coil and the shear friction heat of the screw itself, the polydodecylamide is gradually melted and plasticized into a uniform viscous melt. During extrusion, at least one filter screen is set to stabilize the pressure of the melt and filter impurities. Subsequently, the filtered clean melt is pushed into the die head of the extruder, split by a distributor, and then evenly coated on the outer surface of the protective layer 4 through the gap between the die core and the die sleeve, forming an insulating layer 5 of a certain wall thickness.

[0046] In one embodiment, the screw can be a PVC screw with a length-to-diameter ratio of L / D = 25:1 to 30:1, which allows the polydodecanoic acid to be fully melted and mixed evenly, and a compression ratio of 2.5 to 3.0:1, which allows the polydodecanoic acid to be fully compacted and compressed, and its internal gas to be discharged.

[0047] Where L is the effective working length of the screw, and D is the screw diameter; the compression ratio refers to the ratio of the volume of the first screw groove at the screw inlet to the volume of the last screw groove closest to the extruder head.

[0048] In one embodiment, during the extrusion process, the temperature of the extruder body is set to 210°C-230°C, and the temperature of the die head is set to 220°C-240°C to ensure that the polydodecylamide is fully melted, mixed, and extruded.

[0049] Since the newly extruded insulation layer 5 is still in a high-temperature softened state, it must undergo a cooling and shaping process to achieve cooling and shaping.

[0050] In one embodiment, the cooling and shaping process employs a three-stage cooling method: the first stage uses a cooling temperature of 40°C-50°C, the second stage uses a cooling temperature of 25°C-30°C, and the third stage uses natural cooling. Compared to the traditional rapid cooling process, this significantly reduces the residual stress caused by thermal shrinkage between the insulation layer 5, the fire-resistant layer 3, and the central conductor 1, thus avoiding delamination and bulging problems caused by stress release in the later stages.

[0051] See Figure 4 The cable manufacturing method provided in this embodiment of the invention further includes the following steps: Step S310: Heat the area of ​​the cable 100 to be bent at a first preset temperature for a second preset time.

[0052] In step S310, the first preset temperature is 80℃-100℃, and the second preset time is 5min-10min.

[0053] The present invention provides an embodiment of the invention that preheats and softens the area to be bent at 80°C-100°C for 5-10 minutes, which can release the residual internal stress of the extruded cable and reduce the problem of interlayer bulging caused by internal stress.

[0054] Step S320: Place the area to be bent of the heat-treated cable 100 in the bending device and drive the bending device to bend the area to be bent of the cable 100.

[0055] In step S320, the bending device can be a silicone buffer fixture, and the bending is performed by bending at a uniform speed and slowly to avoid the instantaneous impact force or alternating bending fatigue stress concentration acting on the interface of the refractory layer 3.

[0056] Step S330: Apply heat insulation treatment to the bending area of ​​the cable 100 after bending to fix its shape.

[0057] In step S330, the bending area of ​​the cable 100 can be treated by heat preservation at 70°C for 2 hours to eliminate stress, ensure that the layers of the bending area of ​​the cable 100 are tightly bonded, and have a smooth appearance to avoid bulging.

[0058] Stress relief control measures were adopted in the above bending and forming process. Through the elastic pressure equalization effect of the silicone buffer fixture and the uniform and slow bending effect, and the corresponding temperature control measures before and after bending, it was ensured that the stress borne by the fire-resistant layer 3 and other interlayer interfaces before, during and after bending was always lower than its bonding strength limit. Combined with the structural strength of the central conductor 1, this effectively prevented the occurrence of failure phenomena such as bulging, delamination, peeling and cracking of cable 100.

[0059] like Figure 2 As shown, an embodiment of the present invention also provides a cable 100, which includes a center conductor 1, a base coating 2, a fire-resistant layer 3, a protective layer 4, and an insulation layer 5.

[0060] The center conductor 1 is prepared using the cable preparation method provided in the above embodiment, and the outer surface of the center conductor 1 is coated with a base coating 2.

[0061] The refractory layer 3 is wrapped around the outer surface of the base layer 2.

[0062] The protective layer 4 is wrapped around the outer surface of the fire-resistant layer 3. The protective layer 4 includes a hot melt adhesive layer and an inner lining layer. The hot melt adhesive layer is bonded to the fire-resistant layer 3 and the inner lining layer.

[0063] The insulating layer 5 is wrapped around the outer surface of the protective layer 4.

[0064] In this embodiment of the invention, the cable 100 has a base coating 2 between the center conductor 1 and the fire-resistant layer 3. The base coating 2 improves the bonding strength between the fire-resistant layer 3 and the center conductor 1. At the same time, a protective layer 4 is provided on the outer surface of the fire-resistant layer 3. Specifically, a hot melt adhesive layer is used to bond the fire-resistant layer 3 and the inner lining layer to prevent water vapor and moisture from entering the cable 100. By improving the bonding strength between the inside and outside of the fire-resistant layer 3 and preventing interference from the outside air, the interlayer tightness of the cable 100 is improved, thereby improving the long-term reliability and safety of the cable 100.

[0065] In one embodiment, the cross-sectional shape of the central conductor 1 is an oval rectangle.

[0066] In this embodiment of the invention, the cross-section of the center conductor 1 is made of an oval rectangle, which can eliminate the problem in the prior art where the center conductor 1 with a right angle or sharp corner is prone to piercing the refractory layer 3 and causing local bulging, and further improve the interlayer bonding strength.

[0067] In one embodiment, the base coating 2 is an epoxy sealing base coating 2, the thickness of which is h1, and 0.01mm≤h1≤0.02mm.

[0068] After the surface of the central conductor 1 is degreased, dusted, and dried and preheated, the epoxy sealing base coating 2 is uniformly applied. In this embodiment of the invention, the base coating 2 is an epoxy sealing base coating 2. Since the epoxy sealing base coating 2 can also block the upward penetration of water vapor, it can enhance the adhesion of the fire-resistant layer 3 and prevent the subsequent epoxy sealing base coating 2 from bubbling and falling off, thereby greatly improving the interfacial bonding strength between the central conductor 1 and the fire-resistant layer 3.

[0069] In one embodiment, the refractory layer 3 can be a wrapping tape that overlaps and wraps around the outside of the base layer 2. The wrapping tape can be mica tape, ceramicized silicone tape, synthetic mica tape, etc.

[0070] In one embodiment, wrapping the base coating 2 with a wrapping tape can improve the fire resistance of the cable 100 and ensure that the cable 100 can still operate stably and normally under emergency conditions such as flame conditions.

[0071] In one embodiment, the thickness of the wrapping tape is h2, and 0.12mm≤h2≤0.14mm. The overlap width between adjacent wrapping tape loops is 40%-50% of the wrapping tape width, and the wrapping angle is 45°-60°. This can eliminate the defects of protrusions and longitudinal strip cavities caused by multiple layers of wrapping tape, improving the structural compactness and reliability.

[0072] In one embodiment, the wrapping tension of the wrapping tape is controlled at 0.15 N / mm. 2 -0.18N / mm 2 Furthermore, the wrapping tension fluctuation is no greater than ±3%. By controlling the wrapping tension of the wrapping tape within a reasonable range, it is possible to ensure that the wrapping tape is flat, wrinkle-free, loose, and free from tensile deformation during wrapping, thereby further improving structural stability.

[0073] In one embodiment, before the wrapping tape is overlapped and wrapped around the base coating 2, it needs to undergo a constant temperature drying step of 75°C-95°C for 12-20 hours, which can reduce the moisture content of the wrapping tape to ≤0.3% and avoid unstable interface bonding caused by moisture in the wrapping tape.

[0074] In one embodiment, the process of overlapping the wrapping tape around the base coating 2 is dried with hot air at 90°C-110°C, which can remove the trace amounts of water vapor and trapped air between the layers of the refractory layer 3 in real time, thereby avoiding the problem of high-temperature water vapor vaporization forming internal bubbles in the subsequent extrusion step, which would affect the structural stability.

[0075] In another embodiment, the refractory layer 3 may be formed by extruding a refractory layer through a mold onto the base layer 2 to form a continuous and seamless tubular layer. The refractory layer 3 may also be formed by longitudinally wrapping a metal strip around the outer surface of the base layer 2, and the joints may overlap or butt-weld to form a tube.

[0076] In one embodiment, the inner lining can be a polyester tape, polypropylene foam tape, polyvinyl chloride tape, etc., which can provide a stable, protective, and processable intermediate transition layer.

[0077] In one embodiment, the thickness of the inner liner is h3, where 0.10 mm ≤ h3 ≤ 0.16 mm, and the thickness of the hot melt adhesive layer is h4, where 0.04 mm ≤ h4 ≤ 0.06 mm. Increasing the thickness of the inner liner can improve puncture resistance and thermal barrier capabilities, but it should not be too thick. As an adhesive sealing layer, increasing the thickness of the hot melt adhesive layer is beneficial for filling the interlayer gaps of the cable 100, achieving longitudinal water blocking, and buffering interfacial shear strain. Similarly, it should not be too thick. Therefore, in this embodiment of the invention, the thicknesses of the inner liner and the hot melt adhesive layer are controlled within the above-mentioned ranges. The combination of the two achieves a dynamic balance between mechanical protection, stress buffering, and interfacial adhesion, effectively suppressing phenomena such as interlayer bulging, delamination, and cracking.

[0078] In this embodiment of the invention, an inner lining layer is wrapped around the outside of the refractory layer 3, and a hot melt adhesive layer is provided on the inner surface of the inner lining layer. The hot melt adhesive layer can melt and flow in the subsequent high-temperature extrusion step, automatically filling the tiny gaps between the wrapping tape layers, the wrapping overlap gaps, and the microscopic cavities, so that the refractory layer 3 forms an integral sealed structure, preventing air from entering or being trapped inside, thus improving structural stability. At the same time, it can also play a role in flexible buffering, dispersing shear stress, and inhibiting interlayer slippage and voiding during subsequent bending, thus solving the problem of bulging during bending.

[0079] In one embodiment, the material of the insulation layer 5 is modified polydodecanoic acid. The modified polydodecanoic acid is wrapped in the protective layer 4. On the one hand, its low water absorption property can prevent the structure from being affected by water absorption in the environment later. On the other hand, it can also improve the abrasion resistance and resistance to termite / rodent bites of the cable 100, and prevent mechanical damage and biological erosion.

[0080] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0081] It should be noted that, where there is no conflict, the features in the embodiments of this invention can be combined with each other.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a cable, characterized in that, Includes the following steps: Copper and aluminum are heated to a molten state to obtain copper melt and aluminum melt; The copper melt and the aluminum melt are injected into the same mold through independent flow channels, so that the copper melt and the aluminum melt form an inner and outer layer distribution structure in the mold with a copper cladding layer covering an aluminum core layer; The copper melt and the aluminum melt are kept at a constant temperature so that a metallurgical bonding layer is formed at the interface between the copper melt and the aluminum melt. The center conductor (1) is obtained by cooling through a cooling system.

2. The method for preparing the cable according to claim 1, characterized in that, The method for preparing the cable further includes the following steps: A base coating (2) is applied to the outer surface of the central conductor (1); A refractory layer (3) is wrapped around the outer surface of the base coating (2); A protective layer (4) is wrapped around the outer surface of the fire-resistant layer (3); An insulating layer (5) is extruded onto the outer surface of the protective layer (4), and the insulating layer (5) is cooled and shaped after extrusion to obtain a cable.

3. The method for preparing the cable according to claim 2, characterized in that, The step of wrapping the refractory layer (3) on the outer surface of the base coating (2) includes: The wrapping tape is overlapped and wrapped around the outer surface of the base coating (2) to form the fire-resistant layer (3); The overlap width between adjacent loops of the wrapping tape is 40%-50% of the width of the wrapping tape, and the wrapping angle of the wrapping tape is 45°-60°.

4. The method for preparing the cable according to claim 3, characterized in that, During the process of wrapping the wrapping tape around the outer surface of the base coating (2), hot air drying at 90℃-110℃ is used for shaping.

5. The method for preparing the cable according to claim 3, characterized in that, Before overlapping and wrapping the wrapping tape around the outer surface of the base coating (2), the method further includes: The wrapping tape is dried with hot air at a constant temperature of 75℃-95℃ for a first preset time, wherein the first preset time is 12h-20h.

6. The method for preparing the cable according to claim 2, characterized in that, The cooling and shaping process of the insulating layer (5) during the extrusion processing on the outer surface of the protective layer (4) is a three-stage cooling process, wherein the cooling temperature of the first stage is 40℃-50℃, the cooling temperature of the second stage is 25℃-30℃, and the third stage adopts natural cooling.

7. The method for preparing the cable according to claim 2, characterized in that, The method for manufacturing the cable further includes: The area of ​​the cable to be bent is heated at a first preset temperature for a second preset time. The area to be bent after the heat treatment is placed in a bending device, and the bending device is driven to bend the area to be bent. The area to be bent after bending is then insulated to help it set its shape. The first preset temperature is 80℃-100℃, and the second preset time is 5min-10min.

8. A cable, characterized in that, include: The center conductor (1) is prepared by the cable preparation method described in claim 1.

9. The cable according to claim 8, characterized in that, The cable also includes: A base coating (2) is applied to the outer surface of the central conductor (1). A fire-resistant layer (3) is wrapped around the outer surface of the base coating layer (2); A protective layer (4) is wrapped around the outer surface of the fire-resistant layer (3). The protective layer (4) includes a hot melt adhesive layer and an inner lining layer. The hot melt adhesive layer is bonded between the fire-resistant layer (3) and the inner lining layer. An insulating layer (5) is wrapped around the outer surface of the protective layer (4).

10. The cable according to claim 9, characterized in that, The refractory layer (3) is a wrapping tape that overlaps and wraps around the outside of the base layer (2); The thickness of the wrapping tape is h2, and 0.12mm≤h2≤0.14mm; The distance between adjacent loops of the wrapping tape is 40%-50% of the width of the wrapping tape, and the wrapping angle of the wrapping tape is 45°-60°.

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