Extremely cold resistant bending gradient composite self-sensing intelligent cable

Abstract

This invention belongs to the field of wire and cable technology, specifically relating to an extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable. The invention provides an extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable, comprising, from the inside out, a cable core (100), a filling layer (300), an inner sheath (400), and an outer sheath layer (500). The cable core (100) includes an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130). The filling layer (300) further includes a temperature-measuring fiber optic sensing unit (200) and a strain / vibration-sensing fiber optic sensing unit (210). This invention achieves integrated design for extreme cold resistance and high flexibility against repeated bending, making it suitable for polar, plateau, and high-latitude extremely cold environments, and possessing advantages in environmental protection and full life-cycle management.

Description

Technical Field

[0001] This invention belongs to the field of wire and cable technology, specifically relating to an extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable. Background Technology

[0002] In extremely cold regions such as polar regions, plateaus, and high latitudes, the extreme low-temperature environment places extremely high demands on the cold resistance, flexibility, and functional stability of wires and cables. Existing cold-resistant cables mostly use single rubber or elastomer materials, which significantly reduce the flexibility of the materials in low-temperature environments. After repeated bending, they are prone to failures such as insulation cracking and conductor breakage, seriously affecting the service life and operational safety of the cables.

[0003] With the development of smart grids, polar scientific research, plateau engineering, and other fields, the demand for intelligent monitoring functions of cables is becoming increasingly urgent. Traditional smart cables mostly use external sensors or single optical fiber structures. External sensors are prone to failure due to extreme cold environments, while single optical fiber structures are easily broken under pressure when the cable is bent. This not only results in low monitoring accuracy but also makes it difficult to achieve distributed monitoring of multiple parameters such as temperature, strain, and vibration simultaneously.

[0004] Currently, existing cables generally suffer from problems such as low-temperature embrittlement, monitoring failure, and shortened lifespan under extremely cold conditions. There is a lack of cable products that can integrate extreme cold resistance, high flexibility and bending resistance, and multi-parameter self-sensing functions, which cannot meet the actual application needs in extremely cold scenarios.

[0005] Therefore, there is an urgent need to develop a gradient composite self-sensing smart cable that can achieve good bending resistance and cold resistance through structural design and the introduction of functional components, so that it can be better applied in extreme low temperature environments. Summary of the Invention

[0006] The purpose of this invention is to provide an extremely cold-resistant, bend-resistant gradient composite self-sensing intelligent cable. The cable, from the inside out, comprises an ultra-fine twisted conductor, an insulation layer, a buffer elastic layer, a dual-fiber sensing unit, an inner sheath, and an outer sheath. The ultra-fine twisted conductor employs a small-pitch, unidirectional twisted structure with embedded aramid reinforcing fibers. The insulation layer is made of irradiated modified TPV and nano-silica composite. The buffer elastic layer is a silicone rubber-modified polyurethane elastic strip. The inner sheath and insulation layer form a gradient modulus structure. The outer sheath is made of modified cold-resistant TPU. This invention achieves integrated performance in extreme cold resistance and high flexibility against repeated bending, making it suitable for polar, plateau, and high-latitude extreme cold environments, and possessing advantages in environmental protection and full life-cycle management.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an extremely cold-resistant, bending-resistant, gradient composite self-sensing intelligent cable. From the inside out, it includes the cable core (100), the filling layer (300), the inner sheath (400), and the outer sheath (500); The cable core (100) includes an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130); The filling layer (300) also includes a temperature measurement fiber optic sensing unit (200) and a strain / vibration sensing fiber optic sensing unit (210). The temperature-measuring fiber optic sensing unit (200) includes a temperature-measuring fiber (201) and a flexible buffer microtube (202), and the strain / vibration sensing fiber optic sensing unit (210) includes a strain / vibration sensing fiber (211) and a flexible buffer microtube (212).

[0008] As a preferred embodiment, the ultrafine stranded conductor (110) is formed by stranding oxygen-free copper wire and central aramid fiber in the same direction with a small pitch and then annealing. The cable core (100) is made by combining an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130) using a three-layer co-extrusion device.

[0009] The ultra-fine stranded conductor is made of oxygen-free copper wire stranded together, with an aramid reinforcing filament embedded in the center. It adopts a small-pitch, unidirectional stranding structure. Oxygen-free copper wire has excellent conductivity and low-temperature toughness. The stranded structure combined with the small-pitch, unidirectional stranding design ensures that the stress on each filament is uniform during bending, avoiding stress concentration on individual strands. Structurally, this ensures that the cable is less prone to wire breakage when repeatedly bent. The aramid reinforcing filament embedded in the center significantly improves the conductor's tensile strength and structural stability, further optimizing its bending resistance. After annealing, the conductor's flexibility and low-temperature adaptability are further improved, maintaining good conductivity and mechanical properties even in extremely cold environments.

[0010] As a preferred embodiment, the insulating layer (120) is composed of irradiated modified thermoplastic vulcanized rubber and nano-silica.

[0011] This invention utilizes an irradiated modified thermoplastic vulcanized rubber composite with silica to form a highly elastic insulation layer with excellent low-temperature toughness. The irradiation modification treatment significantly improves the crosslinking degree and low-temperature performance of the vulcanized rubber material, allowing it to maintain its rubbery state even in extremely cold environments and preventing low-temperature hardening. The addition of silica enhances the mechanical strength and wear resistance of the insulation layer, while also improving insulation performance and preventing leakage faults. This insulation layer is in direct contact with the conductor, providing ample space for low-temperature deformation and preventing the insulation layer from restricting conductor bending due to low-temperature hardening. This ensures that the insulation layer does not crack or break during repeated bending of the cable.

[0012] As a preferred embodiment, the irradiated modified thermoplastic vulcanizate has a Shore A hardness of 55-65, a melting point of 145-155℃, a tensile strength of 5.5-6.5MPa, an elongation at break of 480-520%, and a tear strength of 15-20kN / m. The nano-silica is carboxyl-modified dendritic nano-silica with an average particle size of 50~200nm.

[0013] The carboxyl-modified dendritic nano-silica of this invention forms strong hydrogen bonds between the carboxyl groups and the irradiated modified thermoplastic vulcanized rubber. By improving interfacial adhesion, it prevents debonding and microcracks at low temperatures, ensuring that the cable is not prone to cracking when bent. The dendritic structure has unique channels and a large specific surface area, which can hinder the orderly arrangement of molecular chains of the irradiated modified thermoplastic vulcanized rubber at low temperatures, and ensures good low-temperature resistance by weakening the entanglement between molecular chains.

[0014] As a preferred embodiment, the buffer elastic layer (130) is a silicone rubber modified polyurethane material; The preparation method of the silicone rubber modified polyurethane material is as follows: First, a high polarity silicone rubber is prepared using octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, methyl mercaptoacetate, and dimethyl benzoate as raw materials. Then, the high polarity silicone rubber and polytetrahydrofuran, 4,4-diisocyanate dicyclohexylmethane, and 1,4-butanediol are used as raw materials to carry out a synthesis reaction to obtain the silicone rubber modified polyurethane material.

[0015] This invention first prepares a silicone rubber intermediate containing carbon-carbon double bonds using octamethylcyclotetrasiloxane and tetramethyltetravinylcyclotetrasiloxane as raw materials. Then, methyl mercaptoacetate is grafted onto the silicone rubber through a mercapto-olefin click reaction. Finally, by utilizing the polarity of the ester group and the interfacial hydrogen bonds formed between the carbonyl oxygen atom and the amino hydrogen atom of the polyurethane hard segment, a low-modulus silicone rubber modified polyurethane material is prepared.

[0016] As a preferred embodiment, the preparation steps of the high polarity silicone rubber are as follows: 90-100 parts by weight of octamethylcyclotetrasiloxane and 30-40 parts by weight of tetramethyltetravinylcyclotetrasiloxane are mixed evenly. Under a nitrogen atmosphere, the mixture is heated to 60-65°C, and then 0.6-0.8 parts by weight of hexamethyldisiloxane are added for a prepolymerization reaction of 60-80 min. Then, 0.4-0.6 parts by weight of benzyltrimethylammonium hydroxide catalyst are added, and the mixture is heated to 80-85°C for a reaction of 4-6 h. The catalyst is deactivated by heating to 170°C, and the mixture is filtered under reduced pressure to obtain a silicone rubber intermediate. 8-10 parts of the silicone oil intermediate are added to 180-200 parts by weight of tetrahydrofuran and stirred for 10-12 h. Then, 8-10 parts by weight of methyl mercaptoacetate are added and stirred for 100-120 min. Finally, 1-2 parts by weight of dimethyl benzoate are added for ultraviolet light treatment, followed by purification under a dark environment and drying to obtain the high polarity silicone rubber.

[0017] As a preferred embodiment, the ultraviolet light treatment conditions are: light intensity of 140~150mW / cm². 2 The time is 15-20 minutes.

[0018] As a preferred embodiment, the synthesis reaction steps are as follows: 8-16 parts by weight of the high-polarity silicone rubber and 15-25 parts by weight of polytetrahydrofuran are mixed, heated to 80-85°C under a nitrogen atmosphere, and then 8-10 parts of 4,4-diisocyanate dicyclohexylmethane are added and reacted for 70-80 min. Then, 0.4-0.6 parts of benzoyl peroxide and 0.4-0.6 parts of triallyl isocyanurate are added and crosslinked at 110-120°C for 20-30 min. After cooling to 80-85°C, 1.4-1.8 parts of 1,4-butanediol are added for chain extension for 100-120 min, followed by drying.

[0019] As a preferred embodiment, the modulus of the silicone rubber-modified polyurethane material in the buffer elastic layer is 2~3 MPa.

[0020] The present invention relates to a silicone rubber modified polyurethane buffer elastic layer that is spirally wound around the outer side of the inner insulation layer. This buffer elastic layer has a low elastic modulus and excellent low-temperature elasticity, and can undergo controllable deformation when the cable is bent, effectively absorbing and dispersing bending stress, preventing stress from concentrating on the internal optical fiber sensing unit, and avoiding the optical fiber from breaking due to excessive stress. At the same time, the spiral winding method and gap filling design can further optimize the flexibility of the cable, reduce friction between layers, improve the cable's repeated bending life, and adapt to frequent bending scenarios in extremely cold environments.

[0021] As a preferred embodiment, the filler layer (300) is polyurethane resin.

[0022] As a preferred embodiment, the inner protective layer (400) is composed of polyolefin and nano-ceramic powder.

[0023] The polyolefin inner protective layer of this invention has the advantages of being halogen-free, low-smoke, and flame-retardant. The addition of nano-ceramic powder can further improve the low-temperature toughness and impact resistance of the inner protective layer, making it suitable for use in extremely cold environments and meeting environmental protection standards.

[0024] As a preferred embodiment, the polyolefin is polyethylene or polypropylene.

[0025] As a preferred embodiment, the nano-ceramic powder is nano-alumina ceramic powder.

[0026] The inner protective layer material of this invention uses a composite of polyolefin and nano-alumina ceramic powder. When subjected to bending stress, the interface between nano-alumina and polyolefin can induce crazes or shear bands to consume energy. At the same time, the nano-alumina ceramic powder has a pinning effect on crack propagation, preventing cracks from penetrating rapidly, thereby maintaining low-temperature bending toughness.

[0027] As a preferred embodiment, the outer sheath layer (500) is made of a modified cold-resistant thermoplastic polyurethane material; The modified cold-resistant thermoplastic polyurethane material is Yuehua New Materials' D685Z modified TPU, with a Shore A hardness of 87, tensile strength of 25MPa, modulus of 4MPa, and flame retardant performance of V-0.

[0028] The outer sheath layer of this invention uses D685Z modified TPU from Yuehua New Materials, which has excellent oil resistance, acid and alkali resistance, low temperature resistance and wear resistance. It can effectively protect the internal structure of the cable from the corrosion of the external environment and maintain good flexibility and mechanical strength in extremely cold environments. At the same time, the wear resistance of the modified TPU material can extend the service life of the cable and is suitable for outdoor use in complex and extremely cold environments.

[0029] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: (1) Excellent adaptability to extreme cold: This invention, through the synergistic design of an inner insulation layer composed of irradiated modified thermoplastic vulcanized rubber and nano silica, and an outer sheath layer of cold-resistant modified thermoplastic polyurethane, combined with the material optimization and structural design of each layer, enables the cable to maintain the overall structural flexibility under extreme cold conditions, effectively avoiding problems such as low-temperature embrittlement and cracking, meeting the application requirements of extreme environments in polar, plateau and high-latitude regions, and filling the technical gap of smart cables in extreme cold scenarios.

[0030] (2) High flexibility and outstanding bending performance: The ultra-fine stranded conductor combined with the central aramid reinforcement and small pitch unidirectional stranding structure, along with the stress dispersion effect of the buffer elastic layer and the gradient modulus structure of the inner sheath and insulation layer, realizes the uniform distribution and gradient release of bending stress, so that the conductor does not break during repeated bending and stress concentration does not occur at the interface of each layer, significantly improving the bending life of the cable and adapting to frequent bending operations in extremely cold environments.

[0031] (3) Intelligent monitoring is reliable and stable: The dual fiber optic sensing units are symmetrically arranged in the neutral layer of the cable, with a flexible buffer microtube on the outside, and the same helical pitch as the conductor. This ensures that the fiber optics deform synchronously with the cable core when bending, without stress damage, effectively solving the problems of easy breakage and unstable monitoring of traditional fiber optic cables when bending. The dual fibers work together to realize distributed synchronous monitoring of temperature, strain and vibration. The monitoring accuracy is high and the response speed is fast, which can detect cable abnormalities in time and ensure the safe operation of the cable. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0033] Figure 1 This is a schematic diagram of the cross-sectional structure of the cable in Embodiment 1 of the present invention. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] The sources of some components in the examples and comparative examples are as follows: Irradiation-modified thermoplastic vulcanizate, model Globalene TPV 1155A, with Shore A hardness of 58, melting point of 150℃, tensile strength of 6.0MPa, elongation at break of 500%, and tear strength of 16kN / m, was purchased from LCY Chemical Industry Co., Ltd. Carboxyl-modified dendritic nano-silica, item number 103698, with an average particle size of 100 nm, was purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. Commercially available nano-silica, item number 103053, with an average particle size of 100nm, was purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. Octamethylcyclotetrasiloxane, CAS No. 556-67-2, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Tetramethyltetravinylcyclotetrasiloxane, CAS No. 2554-06-5, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Hexamethyldisiloxane, CAS No. 107-46-0, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Benzyltrimethylammonium hydroxide, CAS No. 100-85-6, purchased from Sinopharm Chemical Reagent Co., Ltd. Methyl mercaptoacetate, CAS No. 2365-48-2, was purchased from Sinopharm Chemical Reagent Co., Ltd. Benzoin dimethyl ether, CAS No. 24650-42-8, purchased from Sinopharm Chemical Reagent Co., Ltd. Polytetrahydrofuran, product number P117874, was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. 4,4-Diisocyanate dicyclohexylmethane, CAS No. 5124-30-1, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Benzoyl peroxide, CAS No. 94-36-0, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Triallyl isocyanurate, CAS No. 1025-15-6, was purchased from Sinopharm Chemical Reagent Co., Ltd. 1,4-Butanediol, CAS No. 110-63-4, purchased from Sinopharm Chemical Reagent Co., Ltd. The polyurethane resin, brand name CX-613, was purchased from Hubei Chuangxin Polyurethane Materials Co., Ltd. Nano-alumina ceramic powder was purchased from Zhongming Porcelain (Zhejiang) Nanopowder Technology Co., Ltd. Modified cold-resistant thermoplastic polyurethane material, model D685Z, with Shore A hardness of 87, tensile strength of 25MPa, modulus of 4MPa, and flame retardancy of V-0, purchased from Shandong Yuehua New Material Co., Ltd.

[0036] Preparation of silicone rubber modified polyurethane material: 100 parts by weight of octamethylcyclotetrasiloxane and 40 parts by weight of tetramethyltetravinylcyclotetrasiloxane were mixed evenly. Under a nitrogen atmosphere, the mixture was heated to 65°C, and then 0.8 parts by weight of hexamethyldisiloxane were added for a prepolymerization reaction for 80 min. Then, 0.6 parts by weight of benzyltrimethylammonium hydroxide catalyst were added, and the mixture was heated to 85°C for 4 h. The catalyst was deactivated by heating to 170°C, and the mixture was filtered under reduced pressure to obtain a silicone rubber intermediate. 10 parts by weight of the silicone oil intermediate were added to 200 parts by weight of tetrahydrofuran and stirred for 12 h. Then, 10 parts by weight of methyl mercaptoacetate were added and stirred for 120 min. Finally, 2 parts by weight of dimethyl benzoate were added for ultraviolet light treatment (light intensity 150 mW / cm²). 2The mixture was purified and dried in a light-protected environment (time 15 min) to obtain a high-polarity silicone rubber. 16 parts of the high-polarity silicone rubber and 25 parts of polytetrahydrofuran were mixed and heated to 85°C under a nitrogen atmosphere. 10 parts of 4,4-diisocyanate dicyclohexylmethane were added and reacted for 80 min. Then, 0.6 parts of benzoyl peroxide and 0.6 parts of triallyl isocyanurate were added and crosslinked at 120°C for 20 min. After cooling to 85°C, 1.8 parts of 1,4-butanediol were added for chain extension for 120 min. The mixture was then dried to obtain a silicone rubber-modified polyurethane material with a modulus of 2.9 MPa.

[0037] Example 1 This embodiment provides an extremely cold-resistant, bending-resistant gradient composite self-sensing smart cable. From the inside out, it includes the cable core (100), the filling layer (300), the inner sheath (400), and the outer sheath (500); The cable core (100) includes an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130); The filling layer (300) also includes a temperature measurement fiber optic sensing unit (200) and a strain / vibration sensing fiber optic sensing unit (210). The temperature-measuring fiber optic sensing unit (200) includes a temperature-measuring fiber (201) and a flexible buffer microtube (202), and the strain / vibration sensing fiber optic sensing unit (210) includes a strain / vibration sensing fiber (211) and a flexible buffer microtube (212).

[0038] The insulating layer (120) is composed of irradiated modified thermoplastic vulcanized rubber (model Globalene TPV 1155A) and commercially available nano silica (item number 103053).

[0039] The buffer elastic layer (130) is a silicone rubber modified polyurethane material.

[0040] The filler layer (300) is polyurethane resin (brand name CX-613).

[0041] The inner protective layer (400) is composed of polyethylene and nano-alumina ceramic powder.

[0042] The outer sheath layer (500) is D685Z modified TPU from Yuehua New Materials.

[0043] Example 2 This embodiment provides an extremely cold-resistant, bending-resistant gradient composite self-sensing smart cable. From the inside out, it includes the cable core (100), the filling layer (300), the inner sheath (400), and the outer sheath (500); The cable core (100) includes an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130); The filling layer (300) also includes a temperature measurement fiber optic sensing unit (200) and a strain / vibration sensing fiber optic sensing unit (210). The temperature-measuring fiber optic sensing unit (200) includes a temperature-measuring fiber (201) and a flexible buffer microtube (202), and the strain / vibration sensing fiber optic sensing unit (210) includes a strain / vibration sensing fiber (211) and a flexible buffer microtube (212).

[0044] The insulating layer (120) is composed of irradiated modified thermoplastic vulcanized rubber (model Globalene TPV 1155A) and carboxyl-modified dendritic nano-silica.

[0045] The buffer elastic layer (130) is a silicone rubber modified polyurethane material.

[0046] The filler layer (300) is polyurethane resin (brand name CX-613).

[0047] The inner protective layer (400) is composed of polypropylene and nano-alumina ceramic powder.

[0048] The outer sheath layer (500) is D685Z modified TPU from Yuehua New Materials.

[0049] Comparative Example 1 The difference between this comparative example and Example 1 is that no nano-silica is added to the insulating layer (120).

[0050] Comparative Example 2 The difference between this comparative example and Example 1 is that polyurethane resin (brand name CX-613) is used instead of silicone rubber modified polyurethane material in the buffer elastic layer (130).

[0051] Comparative Example 3 The difference between this comparative example and Example 1 is that no nano-alumina ceramic powder is added to the inner protective layer (400).

[0052] Comparative Example 4 The difference between this comparative example and Example 1 is that polyurethane resin (brand name CX-613) is used instead of modified cold-resistant thermoplastic polyurethane material in the outer sheath layer (500).

[0053] Performance testing (1) Wear resistance test: The test shall be conducted in accordance with the requirements of GB / T 3960-2016 Plastics sliding friction and wear test method.

[0054] (2) Low temperature resistance test: The cables of the examples and comparative examples were placed in a low temperature environment of -40℃ for 100h, and the tensile strength before and after the low temperature treatment was tested using a tensile testing machine, and the change rate of tensile strength was calculated; the bending performance after the low temperature treatment was tested using a bending testing machine.

[0055] Table 1 Performance Test Results Compared to Example 1, the use of carboxyl-modified dendritic nano-silica in the insulation layer (120) instead of commercially available nano-silica improves the cable's low-temperature resistance (Example 2); compared to Example 1, the absence of nano-silica in the insulation layer (120) results in a decrease in the cable's low-temperature resistance due to the lack of silica in the insulation layer (Comparative Example 1); compared to Example 1, the use of polyurethane resin (brand name CX-613) in the buffer elastic layer (130) instead of silicone rubber-modified polyurethane material results in a lack of silicone rubber-modified polyurethane material in the insulation layer. The cable's low-temperature resistance deteriorates (Comparative Example 2); compared to Example 1, no nano-alumina ceramic powder is added to the inner sheath (400), and the lack of nano-alumina ceramic powder in the inner sheath results in a deterioration in the cable's low-temperature resistance (Comparative Example 3); compared to Example 1, polyurethane resin (brand name CX-613) is used to replace the modified cold-resistant thermoplastic polyurethane material in the outer sheath (500), and the lack of modified cold-resistant thermoplastic polyurethane material in the outer sheath results in a deterioration in the cable's low-temperature resistance and an increase in wear (Comparative Example 4).

Claims

1. A cold-resistant, bending-resistant gradient composite self-sensing intelligent cable, characterized in that, From the inside out, it includes the cable core (100), the filling layer (300), the inner sheath (400), and the outer sheath (500); The cable core (100) includes an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130); The filling layer (300) also includes a temperature measurement fiber optic sensing unit (200) and a strain / vibration sensing fiber optic sensing unit (210). The temperature-measuring fiber optic sensing unit (200) includes a temperature-measuring fiber (201) and a flexible buffer microtube (202), and the strain / vibration sensing fiber optic sensing unit (210) includes a strain / vibration sensing fiber (211) and a flexible buffer microtube (212).

2. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 1, characterized in that, The ultrafine twisted conductor (110) is formed by twisting oxygen-free copper wire and central aramid fiber in the same direction with a small pitch and then annealing. The cable core (100) is made by combining an ultra-fine twisted conductor (110), an insulation layer (120), and a buffer elastic layer (130) using a three-layer co-extrusion device.

3. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 1, characterized in that, The insulating layer (120) is composed of irradiated modified thermoplastic vulcanized rubber and nano-silica.

4. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 3, characterized in that, The irradiated modified thermoplastic vulcanizate has a Shore A hardness of 55-65, a melting point of 145-155℃, a tensile strength of 5.5-6.5MPa, an elongation at break of 480-520%, and a tear strength of 15-20kN / m. The nano-silica is carboxyl-modified dendritic nano-silica with an average particle size of 50~200nm.

5. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 1, characterized in that, The buffer elastic layer (130) is a silicone rubber modified polyurethane material; The preparation method of the silicone rubber modified polyurethane material is as follows: First, a high polarity silicone rubber is prepared using octamethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, methyl mercaptoacetate, and dimethyl benzoate as raw materials. Then, the high polarity silicone rubber and polytetrahydrofuran, 4,4-diisocyanate dicyclohexylmethane, and 1,4-butanediol are used as raw materials to carry out a synthesis reaction to obtain the silicone rubber modified polyurethane material.

6. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 5, characterized in that, The preparation steps of the high polarity silicone rubber are as follows: 90-100 parts by weight of octamethylcyclotetrasiloxane and 30-40 parts by weight of tetramethyltetravinylcyclotetrasiloxane are mixed evenly. Under a nitrogen atmosphere, the mixture is heated to 60-65°C, and then 0.6-0.8 parts by weight of hexamethyldisiloxane are added for a prepolymerization reaction for 60-80 min. Then, 0.4-0.6 parts by weight of benzyltrimethylammonium hydroxide catalyst are added and the mixture is heated to 80-85°C for 4-6 h. The catalyst is deactivated by heating to 170°C, and the mixture is filtered under reduced pressure to obtain a silicone rubber intermediate. 8-10 parts of the silicone oil intermediate are added to 180-200 parts by weight of tetrahydrofuran and stirred for 10-12 h. Then, 8-10 parts by weight of methyl mercaptoacetate are added and stirred for 100-120 min. Then, 1-2 parts by weight of benzoin dimethyl ether are added for ultraviolet light treatment. The mixture is purified under a light-protected environment and dried to obtain the high polarity silicone rubber.

7. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 5, characterized in that, The steps of the synthesis reaction are as follows: by weight, 8-16 parts of the high polarity silicone rubber and 15-25 parts of polytetrahydrofuran are mixed, heated to 80-85°C under a nitrogen atmosphere, and then 8-10 parts of 4,4-diisocyanate dicyclohexylmethane are added and reacted for 70-80 min. Then, 0.4-0.6 parts of benzoyl peroxide and 0.4-0.6 parts of triallyl isocyanurate are added and crosslinked at 110-120°C for 20-30 min. After cooling to 80-85°C, 1.4-1.8 parts of 1,4-butanediol are added for chain extension for 100-120 min, and then dried.

8. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 1, characterized in that, The filler layer (300) is polyurethane resin.

9. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 1, characterized in that, The inner protective layer (400) is composed of polyolefin and nano-ceramic powder; The polyolefin is polyethylene or polypropylene; The nano-ceramic powder is nano-alumina ceramic powder.

10. The extremely cold-resistant, bending-resistant gradient composite self-sensing intelligent cable according to claim 1, characterized in that, The outer sheath layer (500) is a modified cold-resistant thermoplastic polyurethane material; The modified cold-resistant thermoplastic polyurethane material is Yuehua New Materials' D685Z modified TPU, with a Shore A hardness of 87, tensile strength of 25MPa, modulus of 4MPa, and flame retardant performance of V-0.

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