A heat-resistant flame-retardant multifunctional power cable and a manufacturing method thereof

Abstract

This invention discloses a heat-resistant and flame-retardant multifunctional power cable and its manufacturing method. The power cable includes a cable core and a cable sheath wrapping the cable core, with ceramicized silicone foam filling the space between the cable core and the cable sheath. The cable sheath includes an insulating substrate layer, a flame-retardant heat dissipation layer disposed on its inner side, and a wear-resistant reinforcement layer disposed on its outer side. The inner and outer surfaces of the insulating substrate layer are respectively provided with multiple first connecting blocks and multiple second connecting blocks. Correspondingly, the inner surfaces of the flame-retardant heat dissipation layer and the wear-resistant reinforcement layer are respectively provided with first connecting slots and second connecting slots that fit into them. The multiple first connecting blocks and multiple second connecting blocks are staggered circumferentially along the insulating substrate layer. Compared with the prior art, the power cable provided by this invention, through innovative structural and material design, synergistically achieves multiple functions such as heat resistance and flame retardancy, high strength, wear resistance, bending resistance, and long lifespan.

Description

Technical Field

[0001] This invention belongs to the field of cable manufacturing technology, and in particular relates to a heat-resistant and flame-retardant multifunctional power cable and its manufacturing method. Background Technology

[0002] Power cables are crucial components ensuring the safe and reliable operation of smart grids and various power systems under laying, operation, and high-temperature environments. With the continuous advancement of power infrastructure construction and the rapid development of smart grids and new energy power generation, the operating environment of power cables is becoming increasingly complex and demanding. In practical applications, cables not only need to withstand mechanical stresses such as tension, bending, and torsion during installation, but also need to withstand high-temperature environments, mechanical impacts, ultraviolet aging, and potential external compression and abrasion during long-term use. Therefore, their manufacturing materials must simultaneously possess high heat resistance and flame retardancy, high mechanical strength, excellent wear resistance, and good bending resistance.

[0003] Cables typically consist of cable cores and a cable sheath that wraps around them. The cable sheath, as the outermost protective structure of the cable, directly determines its ability to resist external environmental damage. Currently, the industry commonly uses plastic materials such as polyvinyl chloride (PVC) and polyethylene (PE) to manufacture cable sheaths through processes such as extrusion. However, existing cable sheaths often employ a single-layer structure made of a single material, or are simply multi-layer structures composed of different materials.

[0004] This type of structure has the following main shortcomings: First, when subjected to bending, torsion, or other stresses, or external impacts, the layers are prone to relative sliding, delamination, or even complete separation due to differences in material properties, thermal expansion coefficients, and weak interfacial bonding. This not only directly weakens the overall mechanical strength of the sheath, leading to a decrease in its compressive and impact resistance, but also creates stress concentration points at the interfaces, accelerating material fatigue damage. Second, the simple stacked structure makes it difficult to synergistically optimize the various properties of the materials. Often, high rigidity is sacrificed for toughness, or flexibility is insufficient to provide adequate puncture resistance and resistance to external damage. As a result, the long-term protective effect of the cable sheath is greatly reduced, and cable damage may occur due to localized failure, thus affecting the service life and safety reliability of the entire cable system. Furthermore, the design of traditional cable sheaths in terms of heat resistance and flame retardancy is relatively simple, usually relying on adding flame retardants to the base material to achieve flame retardancy. However, this method often reduces the mechanical properties of the material and has poor heat dissipation, making it difficult to meet the requirements for long-term stable operation in high-temperature environments.

[0005] Therefore, how to innovate in terms of material structure and composite mechanism to simultaneously improve the heat resistance, flame retardancy, high strength, wear resistance, bending resistance and anti-delamination properties of cables has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a heat-resistant and flame-retardant multifunctional power cable and its manufacturing method. This power cable possesses multiple functions such as heat resistance, flame retardancy, high strength, wear resistance, bending resistance, anti-delamination, and long lifespan.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A heat-resistant and flame-retardant multifunctional power cable, the power cable including a cable core and a cable sheath wrapped around the outer surface of the cable core, wherein ceramicized silicone foam is filled between the cable core and the cable sheath. The cable sheath includes an insulating substrate layer, a flame-retardant and heat-dissipating layer disposed on the inner surface of the insulating substrate layer, and a wear-resistant reinforcing layer disposed on the outer surface of the insulating substrate layer. The inner surface of the insulating substrate layer is provided with a plurality of first connecting blocks, and the surface of the flame-retardant heat dissipation layer in contact with the insulating substrate layer is provided with a plurality of first connecting slots that fit into the first connecting blocks; the outer surface of the insulating substrate layer is provided with a plurality of second connecting blocks, and the surface of the wear-resistant reinforcement layer in contact with the insulating substrate layer is provided with a plurality of second connecting slots that fit into the second connecting blocks; the plurality of first connecting blocks and the plurality of second connecting blocks are staggered along the circumference of the insulating substrate layer.

[0008] Preferably, the cross-sections of the first connecting block and the second connecting block are both isosceles trapezoidal, and the width of the cross-sections of the first connecting block and the second connecting block gradually increases in the direction away from the insulating substrate layer.

[0009] Preferably, the angle α1 between the side of the first connecting block and the horizontal plane of the insulating substrate layer satisfies the relationship: 45°≤α1≤65°; the angle α2 between the side of the second connecting block and the horizontal plane of the insulating substrate layer satisfies the relationship: 45°≤α2≤65°.

[0010] Preferably, the outer surface of the wear-resistant reinforcement layer is provided with a plurality of alternating and spaced protrusions and grooves, and the height h of the protrusions, the depth d of the grooves and the total thickness H of the wear-resistant reinforcement layer satisfy the following relationship: 1 / 3H≤h≤1 / 2H, 1 / 3H≤d≤1 / 2H.

[0011] Preferably, the opening position of the second connecting slot corresponds to the position of the protrusion; the opening position of the first connecting slot corresponds to the position of the groove.

[0012] Preferably, the ratio of the height of the first connecting block to the thickness of the flame-retardant heat dissipation layer is D1, and D1 satisfies the relationship: 1 / 3≤D1≤2 / 3; the ratio of the height of the second connecting block to the thickness of the wear-resistant reinforcement layer is D2, and D2 satisfies the relationship: 1 / 3≤D2≤2 / 3.

[0013] Preferably, the thickness of the insulating substrate layer is 2-6 mm; the thickness of the flame-retardant heat dissipation layer is 1-3 mm; and the thickness of the wear-resistant reinforcement layer is 1-3 mm.

[0014] Preferably, the insulating substrate layer is made of PA66, and both sides of the insulating substrate layer are corona treated to form a rough surface with unevenness; the corona treatment voltage is 2.0~2.2kV, the current is 8A, the corona velocity is 40~50m / min, and the treatment time is 8~10s.

[0015] Preferably, the flame-retardant heat dissipation layer comprises beryllium oxide, polyethylene glycol, and isoflurane diisocyanate adhesive, wherein the mass ratio of beryllium oxide, polyethylene glycol, and isoflurane diisocyanate adhesive is (2~4):(1~2):(4~8); the average relative molecular mass of polyethylene glycol is 18000~19000, and its phase transition temperature is 60~64℃.

[0016] Preferably, in the flame-retardant heat dissipation layer, the average particle size d1 of the isoflurane diisocyanate adhesive is greater than the average particle size d2 of the polyethylene glycol and the average particle size d3 of the beryllium oxide, and d1 / d2=(2~10):1, d1 / d3=(2~10):1; wherein d1 is 0.5~10μm, and d2 and d3 are 0.05~5μm respectively.

[0017] Preferably, the wear-resistant reinforcing layer comprises cubic boron nitride, quartz fiber and isoflurane diisocyanate adhesive, wherein the mass ratio of cubic boron nitride, quartz fiber and isoflurane diisocyanate adhesive is (2~4):(1~2):(4~8).

[0018] Preferably, in the wear-resistant reinforcing layer, the average particle size d1 of the isoflurane diisocyanate adhesive is greater than the average particle size d4 of the cubic boron nitride and the average diameter d5 of the quartz fiber, and d1 / d4=(2~10):1, d1 / d5=(2~10):1; wherein d1 is 0.5~10μm, and d4 and d5 are 0.05~5μm respectively.

[0019] Preferably, flame retardant particles are uniformly dispersed inside the insulating substrate layer, and the flame retardant particles are nano-magnesium hydroxide or nano-aluminum hydroxide.

[0020] Preferably, the ceramicized silicone foam comprises the following components in parts by weight: 30-40 parts vinyl silicone oil, 10-20 parts silica, 20-50 parts nano aluminum nitride powder, 0.1-1.0 parts ethynylcyclohexanol, 1-10 parts hydrogen-containing silicone oil, 1-10 parts hydroxyl silicone oil, 0.1-1.0 parts platinum catalyst, 10-20 parts hexagonal aluminum phosphate, and 1-8 parts halloysite nanotubes.

[0021] Preferably, the method for preparing the ceramicized silicone foam includes the following steps: S1. Add the vinyl silicone oil, silica, nano aluminum nitride powder and hexagonal aluminum phosphate to a kneader, knead into a ball at 100~150℃, cool, and obtain the base adhesive. S2. Stir the hydroxyl silicone oil and halloysite nanotubes at a speed of 23000~26000 r / min for 10~25s to obtain a foamed mixture; S3. Add the foaming mixture, ethynylcyclohexanol, hydrogen-containing silicone oil and platinum catalyst to the base adhesive, mix evenly, and obtain the adhesive compound. S4. The rubber material is vulcanized and foamed using casting, calendering or molding processes to obtain the ceramicized silicone foam.

[0022] Furthermore, the present invention also provides a method for manufacturing the heat-resistant and flame-retardant multifunctional power cable as described above, comprising the following steps: Step 1: Prepare the insulating substrate layer: The insulating substrate layer material is prepared into a tubular structure by extrusion molding process. Multiple first connecting blocks are formed on the inner surface of the tubular structure, and multiple second connecting blocks are formed on the outer surface of the tubular structure. The multiple first connecting blocks and the multiple second connecting blocks are staggered along the circumferential direction. Step 2: Prepare the flame-retardant heat dissipation layer: The flame-retardant heat dissipation layer material is formed on the inner surface of the insulating substrate layer by molding or coating process, so that the first connecting groove on the surface of the flame-retardant heat dissipation layer is fitted with the first connecting block; Step 3: Prepare the wear-resistant reinforcement layer: The wear-resistant reinforcement layer material is formed on the outer surface of the insulating substrate layer by molding or coating process, so that the second connecting groove on the surface of the wear-resistant reinforcement layer is fitted with the second connecting block, and multiple alternating and spaced protrusions and grooves are formed on the outer surface of the wear-resistant reinforcement layer to obtain the cable sheath; Step 4: Prepare ceramicized silicone foam and wrap the ceramicized silicone foam around the outer surface of the cable core wire; Step 5: Insert the cable core wire covered with ceramicized silicone foam into the cable sheath, so that the ceramicized silicone foam fills the space between the cable core wire and the cable sheath, thus obtaining the heat-resistant and flame-retardant multifunctional power cable.

[0023] The beneficial effects of this invention are as follows: This invention achieves synergistic cooperation among the functional layers by designing a multi-layer composite cable sheath structure consisting of an insulating substrate layer, a flame-retardant heat dissipation layer, and a wear-resistant reinforcement layer. Specifically, the wear-resistant reinforcement layer effectively enhances the wear and impact resistance of the cable sheath's outer surface; and the flame-retardant heat dissipation layer effectively improves the cable sheath's heat resistance, flame retardancy, and heat dissipation performance.

[0024] Meanwhile, this invention forms a mechanical interlocking structure by setting multiple first connecting blocks on the inner surface of the insulating substrate layer and multiple second connecting blocks on its outer surface. The first connecting blocks engage with the first connecting slots of the flame-retardant heat dissipation layer, and the second connecting blocks engage with the second connecting slots of the wear-resistant reinforcing layer. This significantly enhances the bonding force between the layers and effectively prevents interlayer delamination under bending or external impact. Specifically, the multiple first and second connecting blocks are staggered circumferentially along the insulating substrate layer, avoiding stress superposition on the same cross-section of the insulating substrate layer. This ensures the wall thickness of the insulating substrate layer in the blocking area, thereby achieving reliable interlayer interlocking without weakening the structural strength and insulation performance of the insulating substrate layer itself. Overall, this improves the bending resistance, structural stability, and service life of the cable sheath.

[0025] Furthermore, by filling the space between the cable core and the cable sheath with ceramicized silicone foam, the present invention can provide good buffer protection for the cable core under normal working conditions. In high-temperature or fire scenarios, the ceramicized silicone foam can quickly form a self-supporting foam ceramic body, effectively blocking the transfer of flames and heat, and further improving the heat resistance and flame retardant performance of the power cable. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the power cable structure of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the power cable of the present invention; Figure 3 This is a schematic diagram of the cable sheath structure of the present invention; Figure 4 This is a schematic diagram of the structure of the insulating substrate layer of the cable sheath of the present invention; Figure 5 This is a schematic diagram of the structure of the flame-retardant and heat-dissipating layer of the cable sheath of the present invention; Figure 6 This is a schematic diagram of the wear-resistant reinforcing layer of the cable sheath of the present invention.

[0027] In the diagram: 1. Cable core wire; 2. Cable sheath; 21. Insulation substrate layer; 211. First connecting block; 212. Second connecting block; 22. Flame-retardant heat dissipation layer; 221. First connecting slot; 23. Wear-resistant reinforcement layer; 231. Second connecting slot; 232. Protrusion; 233. Groove; 3. Ceramicized silicone foam. Detailed Implementation

[0028] To make the technical solution and advantages of the present invention clearer, the present invention and its beneficial effects will be described in further detail below with reference to specific embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0029] like Figures 1-6 As shown, a heat-resistant and flame-retardant multifunctional power cable of the present invention includes a cable core 1 and a cable sheath 2 wrapped around the outer surface of the cable core 1. Ceramicized silicone foam 3 is filled between the cable core 1 and the cable sheath 2. The cable core 1 can be a copper conductor or an aluminum alloy conductor; the present invention does not impose specific limitations on this.

[0030] The cable sheath 2 includes an insulating substrate layer 21, a flame-retardant and heat-dissipating layer 22 disposed on the inner surface of the insulating substrate layer 21, and a wear-resistant reinforcing layer 23 disposed on the outer surface of the insulating substrate layer 21.

[0031] The inner surface of the insulating substrate layer 21 is provided with a plurality of first connecting blocks 211, and the surface of the flame-retardant heat dissipation layer 22 that contacts the insulating substrate layer 21 is provided with a plurality of first connecting slots 221 that fit into the first connecting blocks 211; the outer surface of the insulating substrate layer 21 is provided with a plurality of second connecting blocks 212, and the surface of the wear-resistant reinforcing layer 23 that contacts the insulating substrate layer 21 is provided with a plurality of second connecting slots 231 that fit into the second connecting blocks 212; the plurality of first connecting blocks 211 and the plurality of second connecting blocks 212 are staggered along the circumference of the insulating substrate layer 21.

[0032] The circumferential staggered arrangement of the insulating substrate layer means that on the same cross-section of the insulating substrate layer 21, the inner first connecting block 211 and the outer second connecting block 212 are not in radially opposite positions. That is, the angular positions corresponding to the first connecting block 211 and the second connecting block 212 are staggered. For example, if eight first connecting blocks 211 are uniformly arranged circumferentially on the inner surface of the insulating substrate layer 21, and the angular distance between two adjacent first connecting blocks 211 is 45°, then the eight outer second connecting blocks 212 are respectively deflected by 22.5°. This ensures that the insulating substrate layer 21 does not have both inner and outer blocks on any radial cross-section at the same time, avoiding excessive weakening of the wall thickness of the insulating substrate layer 21 at the same cross-section and ensuring the structural strength of the insulating substrate layer 21 itself.

[0033] The engagement of the first connecting block 211 with the first connecting slot 221 and the engagement of the second connecting block 212 with the second connecting slot 231 both form a mechanical interlocking structure. When the cable sheath 2 is subjected to bending, torsion, or external impact, the interlocking structure can effectively prevent relative slippage and peeling between the layers, allowing each functional layer to bear the external force as a whole, thereby significantly improving the overall structural stability and bending resistance of the cable sheath 2.

[0034] Furthermore, both the first connecting block 211 and the second connecting block 212 have isosceles trapezoidal cross-sections, and the width of the cross-section gradually increases in the direction away from the insulating substrate layer 21, forming a wedge-shaped structure that is wider at the outside and narrower at the inside. This structure is similar to a dovetail joint. When the connecting block is inserted into the connecting slot, the widened head of the block is locked by the inner wall of the slot, forming a self-locking effect. When an external force attempts to peel the functional layer from the insulating substrate layer, a mechanical locking force is generated between the widened part of the block head and the inner wall of the slot, thereby providing greater peel resistance than that of a rectangular cross-section block, further enhancing the interlayer bonding force.

[0035] Furthermore, the angle α1 between the side of the first connecting block 211 and the horizontal plane of the insulating substrate layer 21 satisfies the relationship: 45°≤α1≤65°; the angle α2 between the side of the second connecting block 212 and the horizontal plane of the insulating substrate layer 21 satisfies the relationship: 45°≤α2≤65°. By controlling the angle between the side of the connecting block and the horizontal plane of the insulating substrate layer, a strong interlocking structure can be formed between the insulating substrate layer and the functional layer, effectively preventing delamination. If the angle is too large, an effective interlocking structure cannot be formed; if the angle is too small, the connection may be too weak, leading to structural collapse.

[0036] Furthermore, the outer surface of the wear-resistant reinforcing layer 23 is provided with a plurality of alternating and spaced protrusions 232 and grooves 233. The height h of the protrusions 232, the depth d of the grooves 233 and the total thickness H of the wear-resistant reinforcing layer 23 satisfy the following relationship: 1 / 3H≤h≤1 / 2H, 1 / 3H≤d≤1 / 2H.

[0037] The alternating arrangement of protrusions 232 and grooves 233 creates a structural reinforcement effect. When the cable sheath 2 is subjected to external impact, the protrusions 232 first contact the impactor and disperse the impact force, while the groove area 233 provides a deformation buffer space. Their synergistic effect effectively disperses the external impact stress on the outer surface of the wear-resistant reinforcement layer 23, thereby improving the strength and deformation resistance of the outer surface. When the above proportional relationship is met, the protrusions 232 and grooves 233 have sufficient structural height to exert a stress dispersion effect without excessively weakening the overall thickness of the wear-resistant reinforcement layer 23. This ensures that while the wear-resistant reinforcement layer 23 has a surface strengthening function, its main mechanical properties (such as rigidity and penetration resistance) are not significantly affected. If the protrusion is too high (h > 1 / 2H), the cross-sectional change at the root of the protrusion is too drastic, leading to excessive stress concentration and easy breakage; if the protrusion is too low (h < 1 / 3H), its structural height is insufficient, and the stress dispersion effect is not obvious. The control of the groove depth follows a similar principle.

[0038] Furthermore, the second connecting slot 231 is positioned corresponding to the protrusion 232. That is, the second connecting slot 231 and the protrusion 232 are arranged back-to-back along both sides of the wear-resistant reinforcing layer 23. This design avoids the groove 233 of the wear-resistant reinforcing layer 23, ensuring that the second connecting slot 231 has sufficient groove depth to fit the second connecting block 212, while also ensuring the overall structural strength of the wear-resistant reinforcing layer 23, making the interlayer connection more robust and reliable.

[0039] Furthermore, the opening position of the first connecting slot 221 corresponds to the position of the groove 233. This design allows the first connecting slot 221 and the second connecting slot 231 to be staggered to accommodate the staggered first connecting block 211 and the second connecting block 212, so that the composite cable sheath forms a strong interlayer bond without affecting the overall structural strength of the cable sheath.

[0040] Furthermore, the ratio of the height of the first connecting block 211 to the thickness of the flame-retardant heat dissipation layer 22 is D1, where D1 satisfies the relationship: 1 / 3 ≤ D1 ≤ 2 / 3; the ratio of the height of the second connecting block 212 to the thickness of the wear-resistant reinforcing layer 23 is D2, where D2 satisfies the relationship: 1 / 3 ≤ D2 ≤ 2 / 3. These ratios ensure that the connecting blocks can be embedded deep enough into the functional layer to achieve effective interlocking, while not penetrating the functional layer and affecting the integrity or function of its outer surface. When the ratio is less than 1 / 3, the block embedding depth is insufficient, the interlocking effect is poor, and delamination may still occur under external force; when the ratio is greater than 2 / 3, the block is too deep into the functional layer, which may result in the remaining wall thickness of the functional layer at the tip of the block being too thin, affecting the integrity and functionality of the outer surface of the functional layer.

[0041] Furthermore, the thickness of the insulating substrate layer 21 is 2-6 mm, the thickness of the flame-retardant heat dissipation layer 22 is 1-3 mm, and the thickness of the wear-resistant reinforcement layer 23 is 1-3 mm. As the main structural layer of the cable sheath, the insulating substrate layer 21 needs to have sufficient thickness to ensure electrical insulation performance and overall mechanical strength. The thicknesses of the flame-retardant heat dissipation layer 22 and the wear-resistant reinforcement layer 23 must match those of the insulating substrate layer 21. If the thickness is too thin, the functional effect will be insufficient; if the thickness is too thick, it will increase the overall weight and cost of the cable and affect its flexibility. The aforementioned thickness range ensures that each functional layer functions effectively while also considering the overall flexibility and economy of the cable.

[0042] Furthermore, the insulating substrate layer 21 is made of PA66 (polyamide 66), and both sides of the insulating substrate layer 21 are corona treated to form a rough, uneven surface. The corona treatment voltage is 2.0~2.2kV, the current is 8A, the corona velocity is 40~50m / min, and the treatment time is 8~10s.

[0043] This invention achieves a dual anti-delamination mechanism of "interlayer chemical bonding + physical-mechanical interlocking" by corona treatment of the insulating substrate PA66. On one hand, under the action of the corona current, the electron flow strongly impacts the surface of the PA66 insulating substrate, causing the surface to roughen and form a micro-rough structure with uneven surfaces, thus increasing the actual microscopic area. The inventors observed under a high-magnification microscope that the maximum depth of the untreated PA66 insulating substrate surface is no more than 28 nm, while after corona treatment, the maximum depth reaches 70 nm, and the surface exhibits a distinct uneven texture. This micro-rough structure increases the physical contact area and mechanical interlocking effect between the adhesive and the insulating substrate, thereby enhancing the interlayer physical bonding force.

[0044] On the other hand, under the influence of a high-voltage electric field, a large amount of ozone is generated during the corona treatment process. As a strong oxidant, ozone can cause oxidation reactions in the molecular chains of PA66 polymer materials, producing highly polar groups such as carbonyl groups (C=O) and peroxides on the material surface, thereby increasing its surface energy and affinity for adhesives. Simultaneously, the formation of carbonyl groups introduces new α-carbon atoms into the molecular chains, resulting in active hydrogen. This active hydrogen can chemically react with the isocyanate (-NCO) groups in isoflurane diisocyanate (IPDI) adhesives to form urethane bonds (-NH-CO-O-), creating strong chemical bonds between the bonded materials and the adhesive, further increasing interlayer adhesion.

[0045] Regarding the selection of corona treatment parameters, the inventors discovered through extensive experimental research that for PA66 material, as the corona current increases, the kinetic energy of particles generated during corona discharge increases, which is beneficial for opening the chemical bonds of long molecular chains on the plastic surface. This leads to a gradual increase in surface activity energy and, consequently, surface tension. The peak surface tension of PA66 material occurs when the corona current is around 8A. When the current increases further, the surface tension of PA66 material actually decreases. This is because the amount of air between the electrode and the corona roller has reached a relatively stable state. At this point, the oxygen molecule content in the air is constant. Even if the voltage and current values ​​of the electrodes are increased, it is impossible to activate more oxygen molecules to allow more oxygen-containing functional groups to remain on the surface of PA66 material. Furthermore, excessive corona treatment severely damages the surface structure of PA66 material. Therefore, when the corona current is further increased, the surface tension of PA66 material decreases rapidly. Furthermore, when the corona discharge velocity is too fast (greater than 50 m / min) or the corona treatment time is too short (less than 8 s), insufficient corona treatment will occur, leading to a decrease in the adhesion of the functional layer. When the corona discharge velocity is too slow (less than 40 m / min) or the corona treatment time is too long (greater than 10 s), corona breakdown of the material is likely to occur, resulting in adhesive re-adhesion. Therefore, this invention controls the corona treatment voltage to 2.0~2.2 kV, the current to 8 A, the corona discharge velocity to 40~50 m / min, and the treatment time to 8~10 s. Within this parameter range, the surface tension of the PA66 material can be maximized, resulting in the highest adhesion strength between the functional layer and the insulating substrate.

[0046] Furthermore, the flame-retardant heat dissipation layer 22 includes beryllium oxide, polyethylene glycol and isoflurane diisocyanate adhesive, with a mass ratio of (2~4):(1~2):(4~8).

[0047] Among them, beryllium oxide (BeO) not only has an extremely high heat resistance temperature (melting point of about 2578℃), but also an extremely high thermal conductivity (about 250~300 W / (m·K)), which is much higher than that of common alumina. It can effectively improve the thermal conductivity and heat resistance of cable sheaths, so that the heat generated by the cable core can be quickly conducted to the external environment.

[0048] Polyethylene glycol (PEG) is an organic solid-solid phase change material, meaning that when the phase change temperature is reached, its ordered solid-state molecular structure transforms into a disordered solid-state molecular structure, absorbing a large amount of heat in the process. This invention preferably uses PEG with an average relative molecular mass of 18,000-19,000, whose phase change temperature is 60-64°C. This temperature range falls precisely within the critical region for the normal operating temperature rise of the cable. When the cable temperature reaches 60-64°C, PEG undergoes a solid-solid phase change, absorbing heat and further enhancing the heat dissipation effect of the flame-retardant heat dissipation layer 22, effectively reducing the cable's operating temperature. The average relative molecular mass of PEG cannot be too high or too low. If it is too high, the phase change temperature exceeds the upper limit of the cable's safe operating temperature, and the phase change heat dissipation effect cannot be triggered in time when needed; if it is too low, the phase change temperature is too low, and the phase change occurs at room temperature, failing to play an effective temperature control role when the cable heats up.

[0049] In the flame-retardant heat-dissipating layer 22, isoflurane diisocyanate (IPDI) adhesive serves two main purposes: firstly, it acts as a bonding matrix to fix beryllium oxide and polyethylene glycol; secondly, its reactive isocyanate (-NCO) groups react chemically with the active hydrogen generated after corona treatment of the insulating substrate layer 21, forming strong chemical bonds (urethane bonds) between the bonded materials and the adhesive, further increasing the interlayer adhesion between the flame-retardant heat-dissipating layer 22 and the insulating substrate layer 21. Furthermore, isoflurane diisocyanate adhesive exhibits excellent weather resistance and light stability, and its reaction rate with hydroxyl groups is 4-5 times faster than that of hexamethylene diisocyanate (HDI), which is beneficial for improving production efficiency.

[0050] Furthermore, in the flame-retardant heat dissipation layer 22, the average particle size d1 of the isoflurane diisocyanate adhesive is greater than the average particle size d2 of polyethylene glycol and the average particle size d3 of beryllium oxide, and d1 / d2=(2~10):1, d1 / d3=(2~10):1; where d1 is 0.5~10μm, and d2 and d3 are 0.05~5μm respectively.

[0051] By controlling the aforementioned particle size relationship, the particle size of the isoflurane diisocyanate adhesive is made larger than that of polyethylene glycol and beryllium oxide, thereby causing the isoflurane diisocyanate adhesive particles to protrude from the surface of the flame-retardant heat-dissipating layer 22. When the flame-retardant heat-dissipating layer 22 comes into contact with the corona-treated insulating substrate layer 21, the protruding adhesive particles can more effectively react chemically with the active hydrogen groups on the surface of the insulating substrate, improving the interfacial contact effect between the adhesive and the insulating substrate and increasing the adhesion strength between the flame-retardant heat-dissipating layer 22 and the insulating substrate layer 21.

[0052] Furthermore, the wear-resistant reinforcing layer 23 comprises cubic boron nitride, quartz fiber and isoflurane diisocyanate adhesive, with a mass ratio of (2~4):(1~2):(4~8).

[0053] Cubic boron nitride (c-BN) possesses a hardness second only to diamond (Mohs hardness approximately 9.5~10), making it an excellent wear-resistant material that significantly enhances the surface hardness and wear resistance of the wear-resistant reinforcement layer 23. Furthermore, cubic boron nitride exhibits good chemical inertness and thermal stability, resisting decomposition or reaction with other substances at high temperatures, thus ensuring the long-term stability of the wear-resistant reinforcement layer 23 under high-temperature conditions.

[0054] Quartz fiber, as a reinforcing and toughening material, possesses characteristics such as high strength, high modulus, high toughness, and good corrosion resistance and heat resistance. In the wear-resistant reinforcing layer 23, quartz fiber forms a fiber-reinforced network structure, which can effectively disperse and transfer external loads, significantly improving the overall mechanical strength, impact resistance, and puncture resistance of the wear-resistant reinforcing layer 23.

[0055] The isoflurane diisocyanate adhesive plays a similar role in the wear-resistant reinforcing layer 23 as it does in the flame-retardant heat dissipation layer 22, serving as a bonding matrix on the one hand and forming a chemical bond with the surface of the corona-treated insulating substrate layer 21 on the other.

[0056] Furthermore, in the wear-resistant reinforcing layer 23, the average particle size d1 of the isoflurane diisocyanate adhesive is larger than the average particle size d4 of cubic boron nitride and the average diameter d5 of the quartz fiber, respectively, and d1 / d4=(2~10):1, d1 / d5=(2~10):1; where d1 is 0.5~10μm, and d4 and d5 are 0.05~5μm respectively. The particle size control principle is the same as that in the flame-retardant heat dissipation layer. By making the adhesive particles protrude from the surface of the wear-resistant reinforcing layer, the contact effect between the adhesive and the corona-treated insulating substrate surface is improved, thereby increasing the adhesion strength between the wear-resistant reinforcing layer 23 and the insulating substrate layer 21.

[0057] Furthermore, flame retardant particles, which are nano-magnesium hydroxide or nano-aluminum hydroxide, are uniformly dispersed within the insulating substrate layer 21. These nano-flame retardant particles decompose and absorb heat when heated, releasing water vapor to dilute flammable gases. At the same time, the resulting metal oxide coating layer can provide heat insulation and oxygen barrier functions, thereby significantly improving the flame retardant rating of the insulating substrate layer and even the entire cable sheath.

[0058] Furthermore, the ceramicized silicone foam 3 comprises the following components in parts by weight: 30-40 parts vinyl silicone oil, 10-20 parts silica, 20-50 parts nano aluminum nitride powder, 0.1-1.0 parts ethynylcyclohexanol, 1-10 parts hydrogen-containing silicone oil, 1-10 parts hydroxyl silicone oil, 0.1-1.0 parts platinum catalyst, 10-20 parts hexagonal aluminum phosphate, and 1-8 parts halloysite nanotubes.

[0059] The ceramicized silicone foam 3 provided by this invention not only has excellent elasticity under normal working conditions, providing good buffer protection for the cable core 1, but also can quickly form a self-supporting foam ceramic body at high temperatures, maintaining a high degree of cell structure retention, thereby exhibiting excellent heat insulation and flame retardant effects. Furthermore, it can withstand the burning of flames above 1300℃ for a long time, effectively isolating the transmission of fire and temperature, controlling the fire range within a single cable section, and preventing the fire from igniting adjacent cables.

[0060] The specific functions of each component in the ceramicized silicone foam 3 are as follows: Vinyl silicone oil, as the main polymer matrix, provides the required elasticity and flexibility in foaming systems. It enhances the mechanical strength and thermal stability of the material by undergoing a hydrosilylation reaction with hydrogen-containing silicone oil to form a cross-linked network structure. The amount of vinyl silicone oil used is 30-40 parts. Too little oil results in insufficient cross-linked network density, reducing the material's elasticity and mechanical strength; too much oil leads to excessively high system viscosity, which is detrimental to subsequent processing and molding.

[0061] Silica (fumed silica) serves as a reinforcing agent due to its large specific surface area and abundant surface hydroxyl groups. This allows it to form a strong interfacial interaction with the silicone rubber matrix, increasing the tear strength and abrasion resistance of the composite material. Simultaneously, it improves the compression resistance of the silicone rubber, making the material less prone to deformation even under high loads. The dosage of silica is 10-20 parts; within this range, it can fully exert its reinforcing effect without affecting the material's processing fluidity.

[0062] Nano-aluminum nitride powder serves as a ceramicized flame-retardant filler. It possesses high thermal conductivity (approximately 170~200 W / (m·K)) and high temperature resistance (melting point approximately 2200℃). At high temperatures, it promotes the formation of a hard ceramic layer on the material surface, effectively preventing further propagation of flames and heat. The dosage of nano-aluminum nitride powder is 20~50 parts; too little will result in poor ceramicization, while too much will affect the elasticity and processing properties of the silicone rubber.

[0063] Ethynylcyclohexanol, as an inhibitor, can control the rate of the hydrosilylation reaction through coordination with the platinum catalyst, avoiding local overheating and structural inhomogeneity caused by excessively rapid reaction. The amount of ethynylcyclohexanol used is 0.1~1.0 parts. Too little amount will result in an excessively fast reaction rate, which may lead to uneven local crosslinking density; too much amount will result in an excessively slow reaction rate, affecting production efficiency.

[0064] Hydrogen-containing silicone oil, acting as a crosslinking agent, undergoes a hydrosilylation reaction between the Si-H bonds on its molecular chain and the vinyl groups (Si-CH=CH2) on the vinyl silicone oil molecular chain under the action of a platinum catalyst. This generates Si-CH2-CH2-Si crosslinking bonds, forming a three-dimensional network structure of silicone rubber, which enhances the overall mechanical properties and thermal stability of the material. The amount of hydrogen-containing silicone oil used is 1 to 10 parts, and it needs to be matched according to the vinyl content of the vinyl silicone oil to ensure an appropriate crosslinking density.

[0065] Hydroxy-coated silicone oil acts as a foaming agent in this system. Under heating conditions, the hydroxyl groups (Si-OH) at the ends of the hydroxy-coated silicone oil molecular chains undergo a dehydrogenation reaction with the Si-H bonds on the hydrogen-containing silicone oil molecular chains, producing hydrogen gas (H2). This forms a uniform cell structure within the silicone rubber matrix, providing good cushioning performance and low density. The amount of hydroxy-coated silicone oil used is 1-10 parts. Insufficient use results in insufficient foaming, low cell density, and inadequate cushioning performance; excessive use leads to overly dense cells and a decrease in the material's mechanical strength.

[0066] Platinum catalysts (such as Karstedt or Speier catalysts) catalyze the hydrosilylation crosslinking reaction of vinyl silicone oil and hydrogen-containing silicone oil, improving reaction efficiency and uniformity, and ensuring consistent material properties. The amount of platinum catalyst used is 0.1 to 1.0 parts. Too little catalyst results in low catalytic efficiency and incomplete crosslinking reaction; too much catalyst results in an overly rapid reaction, which is detrimental to processing control.

[0067] Hexagonal aluminum phosphate, as a ceramic-forming agent, can react with SiO2 produced by the thermal decomposition of silicone rubber and other oxides in the system at high temperatures to form a phosphate-silicate composite ceramic phase. This ceramic-forming property can more quickly build a continuous ceramic protective layer on the material surface and inside, shortening the transformation time from polymer to ceramic body. This is crucial for rapidly establishing a thermal barrier in the early stages of sudden thermal runaway. In addition, the molten phase formed by hexagonal aluminum phosphate at high temperatures can effectively wet and encapsulate other fillers (such as halloysite nanotubes) and the residual skeleton of the cell walls, acting as a ceramic adhesive. Specifically, the aluminum phosphate melt can penetrate into the hollow cavity of halloysite nanotubes and its surroundings, reinforcing these tubular support structures at the nanoscale, making them less prone to breakage or collapse at high temperatures, thus maintaining the macroscopic morphology of the cells more persistently. This microstructure of "nanotube reinforcement + phosphate ceramic bonding" is the key to achieving a high porosity retention rate at high temperatures; it can more effectively prevent the collapse and merging of pores at high temperatures, maintain the porous structure of the foam ceramic body, and thus maintain excellent thermal insulation performance.

[0068] Halloysite nanotubes (HNTs), as a cell structure stabilizer, possess a unique hollow tubular nanostructure (outer diameter approximately 40-70 nm, inner diameter approximately 15-30 nm, length approximately 0.5-2 μm), enabling them to form a uniformly distributed tubular support structure within a silicone rubber matrix. On one hand, during foaming, halloysite nanotubes stabilize the cell wall film, preventing adjacent cells from merging and resulting in a more uniform cell size distribution. On the other hand, during high-temperature ceramization, the tubular structure of the halloysite nanotubes acts as a micro-skeleton, enhancing the stability of the cell structure, preventing collapse under high temperature or mechanical pressure, and maintaining a high cell structure retention rate. The optimal dosage of halloysite nanotubes is 1-8 parts; insufficient dosage results in insignificant cell stabilization, while excessive dosage affects the flowability and processability of the silicone rubber matrix.

[0069] The method for preparing the ceramicized silicone foam of the present invention is as follows: Step S1: Add vinyl silicone oil, silica, nano-aluminum nitride powder, and hexagonal aluminum phosphate to a kneader and knead into a ball at 100-150°C. Cool to room temperature to obtain the base adhesive. In this step, high-temperature kneading allows the hydroxyl groups on the surface of silica to fully combine with the vinyl silicone oil, and the nano-aluminum nitride powder and hexagonal aluminum phosphate are uniformly dispersed in the silicone oil matrix, forming a homogeneous base adhesive ball. The kneading temperature is controlled at 100-150°C; too low a temperature will result in uneven mixing, while too high a temperature may lead to partial degradation of the vinyl silicone oil.

[0070] Step S2: Stir the hydroxyl silicone oil and halloysite nanotubes at a speed of 23,000-26,000 r / min for 10-25 s to obtain a foaming mixture. High-speed stirring ensures that the halloysite nanotubes are fully dispersed in the hydroxyl silicone oil, preventing nanotube aggregation and ensuring the uniformity of the foam cells during subsequent foaming. The stirring speed should be controlled at 23,000-26,000 r / min; too low a speed will result in insufficient dispersion of the nanotubes, while too high a speed may lead to excessive shear degradation of the hydroxyl silicone oil. The mixing time should be controlled at 10-25 s; too short a time will result in uneven dispersion, while too long a time may cause localized overheating.

[0071] Step S3: Add the above foaming mixture, ethynylcyclohexanol, hydrogen-containing silicone oil, and platinum catalyst to the base rubber. Mix thoroughly at room temperature using a planetary mixer or a two-roll mill to obtain the rubber compound. The addition of ethynylcyclohexanol in this step inhibits the catalytic activity of the platinum catalyst at room temperature, preventing cross-linking reactions during mixing and ensuring the processability of the rubber compound.

[0072] Step S4: The rubber compound is vulcanized and foamed at 120~180℃ for 10~30 minutes using casting, calendering, or molding processes to obtain ceramicized silicone foam. At this temperature, the inhibitory effect of ethynylcyclohexanol is weakened, and the platinum catalyst catalyzes the hydrosilylation crosslinking reaction of vinyl silicone oil and hydrogen-containing silicone oil. At the same time, hydroxyl silicone oil and hydrogen-containing silicone oil undergo a dehydrogenation reaction to generate hydrogen gas. The foaming process is completed during crosslinking and curing, forming silicone rubber foam with a uniform cell structure.

[0073] The manufacturing method of the heat-resistant and flame-retardant multifunctional power cable of the present invention includes the following steps: Step 1: Preparation of the insulating substrate layer: PA66 granules are selected as the insulating substrate layer material. The PA66 granules are dried at 80~100℃ for 4~6 hours to remove moisture, and then fed into a single-screw extruder. The material is extruded into a tubular structure at a melt temperature of 260~290℃ and a die head temperature of 270~285℃. During extrusion, grooves and protrusions corresponding to the first connecting blocks 211 and the second connecting blocks 212 are respectively set on the inner and outer molds of the extrusion die. Multiple first connecting blocks 211 are formed on the inner surface of the tubular structure, and multiple second connecting blocks 212 are formed on the outer surface. In the die design, the grooves on the inner mold and the protrusions on the outer mold are staggered circumferentially, ensuring that the multiple first connecting blocks 211 and the multiple second connecting blocks 212 are staggered circumferentially along the insulating substrate layer 21. After extrusion, the material is water-cooled, traction-driven, and cut to obtain the insulating substrate layer 21 with the connecting block structure.

[0074] For solutions requiring corona treatment, after the insulating substrate layer 21 is extruded, molded, and cooled, a corona treatment device is used to treat both the inner and outer surfaces of the insulating substrate layer 21. The corona treatment device includes a high-frequency high-voltage generator, corona electrodes, and a grounding roller. During treatment, the insulating substrate layer 21 is passed through the corona treatment area at a speed of 40-50 m / min. The high-frequency high-voltage generator outputs a voltage of 2.0-2.2 kV and a current of 8 A, with a treatment time of 8-10 s. After corona treatment, the surface of the insulating substrate layer 21 forms a micro-rough structure with uneven surfaces, significantly improving its surface energy.

[0075] Step 2: Preparation of the flame-retardant heat dissipation layer: Weigh beryllium oxide, polyethylene glycol, and isoflurane diisocyanate adhesive in a mass ratio of (2~4):(1~2):(4~8). First, mix beryllium oxide and polyethylene glycol evenly, then add isoflurane diisocyanate adhesive and disperse and mix at 1000~3000 r / min for 15~30 min using a high-speed disperser to obtain a flame-retardant heat dissipation layer slurry. Apply the flame-retardant heat dissipation layer slurry evenly to the inner surface of the insulating substrate layer 21 using a coating process. During coating, the slurry fills and embeds into the gaps between the first connecting blocks 211. After the slurry cures and forms, it naturally forms a first connecting groove 221 that fits into the first connecting blocks 211. After coating, cure at 60~80℃ for 2~4 h to allow the isoflurane diisocyanate adhesive to complete cross-linking and curing, resulting in a flame-retardant heat dissipation layer 22 that is firmly bonded to the insulating substrate layer 21. For the corona-treated insulating substrate layer 21, the -NCO groups in the isoflurane diisocyanate adhesive react with the active hydrogen generated by the corona treatment on the PA66 surface during the curing process to form chemical bonds, further enhancing the interlayer bonding force.

[0076] Step 3: Preparation of the wear-resistant reinforcing layer: Weigh cubic boron nitride, quartz fiber, and isoflurane diisocyanate adhesive in a mass ratio of (2~4):(1~2):(4~8). First, mix the cubic boron nitride and quartz fiber evenly, then add the isoflurane diisocyanate adhesive and disperse and mix at 1000~3000 r / min for 15~30 min using a high-speed disperser to obtain the wear-resistant reinforcing layer slurry. Apply the wear-resistant reinforcing layer slurry evenly to the outer surface of the insulating substrate layer 21 using a coating process. During coating, the slurry fills and embeds into the gaps between the second connecting blocks 212. After the slurry cures and forms, it naturally forms the second connecting slot 231 that fits into the second connecting blocks 212. After coating, use a mold with corresponding patterns of protrusions and grooves to press and form the outer surface of the wear-resistant reinforcing layer 23, forming multiple alternating and spaced protrusions 232 and grooves 233. Then, it is cured at 60~80℃ for 2~4 hours to allow the isoflurane diisocyanate adhesive to complete cross-linking and curing, thus obtaining cable sheath 2.

[0077] Step 4: Prepare ceramicized silicone foam 3 according to the aforementioned method for preparing ceramicized silicone foam, and cut the prepared ceramicized silicone foam 3 into appropriate sizes and wrap it around the outer surface of the cable core wire 1.

[0078] Step 5: Insert the cable core 1 covered with ceramicized silicone foam 3 into the cable sheath 2, so that the ceramicized silicone foam 3 fills the space between the cable core 1 and the cable sheath 2, and obtain a heat-resistant and flame-retardant multi-functional power cable.

[0079] The technical solutions and effects of the present invention will be described in detail below through specific embodiments and comparative examples. Example 1

[0080] A heat-resistant and flame-retardant multifunctional power cable includes a cable core 1, ceramicized silicone foam 3, and a cable sheath 2.

[0081] Cable core 1 uses a copper conductor core with a cross-sectional area of ​​10mm².

[0082] The structure of cable sheath 2 is as follows: - Insulating substrate layer 21: The material is PA66, with a thickness of 4mm. Eight first connecting blocks 211 are evenly arranged circumferentially on the inner surface, and eight second connecting blocks 212 are evenly arranged circumferentially on the outer surface. The first connecting blocks 211 and second connecting blocks 212 are offset 22.5° circumferentially. The cross-sections of both the first connecting blocks 211 and second connecting blocks 212 are isosceles trapezoidal, with the cross-sectional width gradually increasing away from the insulating substrate layer 21. The angles α1 and α2 between the side of the first connecting block 211 or the second connecting block 212 and the horizontal plane of the insulating substrate layer 21 are both 60°. The two surfaces of the insulating substrate layer 21 are not corona-treated.

[0083] - Flame-retardant heat dissipation layer 22: 2mm thick, made of beryllium oxide, polyethylene glycol, and isoflurane diisocyanate adhesive in a mass ratio of 3:1.5:6. The average relative molecular mass of polyethylene glycol is 18500, and its phase transition temperature is 62℃. The average particle size d1 of the isoflurane diisocyanate adhesive is 5μm, the average particle size d2 of polyethylene glycol is 1μm, and the average particle size d3 of beryllium oxide is 0.5μm, with d1 / d2=5:1 and d1 / d3=10:1. The surface of the flame-retardant heat dissipation layer 22 in contact with the insulating substrate layer 21 is provided with a first connecting slot 221 that engages with the first connecting block 211. The height of the first connecting block 211 is 1mm, and D1=1 / 2.

[0084] - Wear-resistant reinforcing layer 23: 2mm thick, made of cubic boron nitride, quartz fiber, and isoflurane diisocyanate adhesive in a mass ratio of 3:1.5:6. The average particle size d1 of the isoflurane diisocyanate adhesive is 5μm, the average particle size d4 of the cubic boron nitride is 1μm, and the average diameter d5 of the quartz fiber is 0.5μm, d1 / d4=5:1, d1 / d5=10:1. The surface of the wear-resistant reinforcing layer 23 in contact with the insulating substrate layer 21 is provided with a second connecting groove 231 that engages with the second connecting block 212. The height of the second connecting block 212 is 1mm, and D2=1 / 2. The outer surface of the wear-resistant reinforcing layer 23 is provided with a plurality of alternating and spaced protrusions 232 and grooves 233. The height h of the protrusions 232 is 0.8 mm (h=2 / 5H), and the depth d of the grooves 233 is 0.8 mm (d=2 / 5H). The second connecting slot 231 is located at a position corresponding to the position of the protrusions 232, and the grooves 233 are located at a position corresponding to the position of the first connecting slot 221.

[0085] The ceramicized silicone foam 3 comprises the following components in parts by weight: 35 parts vinyl silicone oil, 15 parts silica, 35 parts nano aluminum nitride powder, 0.5 parts ethynylcyclohexanol, 5 parts hydrogen-containing silicone oil, 5 parts hydroxyl silicone oil, 0.5 parts platinum catalyst, 15 parts hexagonal aluminum phosphate, and 4 parts halloysite nanotubes.

[0086] The preparation method of the ceramicized silicone foam 3 is as follows: S1. Add 35 parts vinyl silicone oil, 15 parts silica, 35 parts nano aluminum nitride powder and 15 parts hexagonal aluminum phosphate to a kneader, knead into a ball at 120°C, cool to room temperature to obtain the base adhesive. S2. Mix 5 parts hydroxyl silicone oil and 4 parts halloysite nanotubes at a speed of 25000 r / min for 15 s to obtain a foamed mixture; S3. Add foaming mixture, 0.5 parts ethynylcyclohexanol, 5 parts hydrogen-containing silicone oil and 0.5 parts platinum catalyst to the base adhesive, and mix evenly at room temperature using a planetary mixer to obtain the adhesive compound; S4. The rubber compound is vulcanized and foamed at 150°C for 20 minutes using a molding process to obtain ceramicized silicone foam 3.

[0087] The manufacturing method of this power cable is as follows: Step 1: Dry PA66 granules at 90℃ for 5 hours, then add them to a single screw extruder and extrude them through a die with inner and outer die blocks at a melt temperature of 275℃ and a die head temperature of 280℃ to form a tubular insulating substrate layer 21. After water cooling, shaping, traction and cutting, the finished product is obtained. Step 2: Weigh beryllium oxide, polyethylene glycol and isoflurane diisocyanate adhesive in a mass ratio of 3:1.5:6, mix and disperse them, and then coat them on the inner surface of the insulating substrate layer 21. The slurry is embedded in the gap of the first connecting block 211 to form the first connecting groove 221. Curing is carried out at 70°C for 3 hours to obtain the flame-retardant heat dissipation layer 22. Step 3: Weigh cubic boron nitride, quartz fiber and isoflurone diisocyanate adhesive in a mass ratio of 3:1.5:6, mix and disperse them, and then coat them on the outer surface of the insulating substrate layer 21. The slurry is embedded in the gap of the second connecting block 212 to form the second connecting groove 231. The protrusion 232 and the groove 233 are formed by mold pressing. The cable sheath 2 is obtained by curing at 70°C for 3 hours. Step 4: Cut the ceramicized silicone foam 3 and wrap it around the outer surface of the cable core 1; Step 5: Insert the cable core 1, which is covered with ceramicized silicone foam 3, into the cable sheath 2 to obtain a heat-resistant and flame-retardant multifunctional power cable. Example 2

[0088] The only difference from Example 1 is that the two sides of the insulating substrate layer 21 are corona treated to form a rough, uneven surface; the parameters of the corona treatment are: voltage 2.1kV, current 8A, corona velocity 45m / min, and treatment time 9s. The rest of the structure, material ratios, and preparation methods are the same as in Example 1. Example 3

[0089] The only difference from Example 2 is the thickness of each layer and the size parameters of the card block: - Insulating substrate layer 21: 2mm thick; -Flame-retardant heat dissipation layer 22: 1mm thick, first connecting block 211 height 0.5mm, D1=1 / 2; - Wear-resistant reinforcing layer 23: thickness is 1mm, the height of the second connecting block 212 is 0.5mm, D2=1 / 2; the protrusion height h=0.4mm (h=2 / 5H), the groove depth d=0.4mm (d=2 / 5H); - Corona treatment parameters: voltage 2.0kV, current 8A, corona velocity 40m / min, treatment time 10s.

[0090] The remaining structure, material ratios, and preparation methods are the same as in Example 2. Example 4

[0091] The only difference from Example 2 is the thickness of each layer and the size parameters of the card block: - Insulating substrate layer 21: Thickness is 6mm; -Flame-retardant heat dissipation layer 22: 3mm thick, first connecting block 211 height 1.5mm, D1=1 / 2; - Wear-resistant reinforcing layer 23: thickness is 3mm, the height of the second connecting block 212 is 1.5mm, D2=1 / 2; the protrusion height h=1.2mm (h=2 / 5H), the groove depth d=1.2mm (d=2 / 5H); - Corona treatment parameters: voltage 2.2kV, current 8A, corona velocity 50m / min, treatment time 8s.

[0092] The ceramicized silicone foam 3 comprises the following components by weight: 40 parts vinyl silicone oil, 20 parts silica, 50 parts nano-aluminum nitride powder, 1.0 part ethynylcyclohexanol, 10 parts hydrogen-containing silicone oil, 10 parts hydroxyl silicone oil, 1.0 part platinum catalyst, 20 parts hexagonal aluminum phosphate, and 8 parts halloysite nanotubes. The preparation method is the same as steps S1-S4 in Example 1, with a kneading temperature of 150℃, a stirring speed of 26000 r / min, a mixing time of 10 s, a vulcanization foaming temperature of 180℃, and a vulcanization foaming time of 15 min.

[0093] The remaining structures and preparation methods are the same as in Example 2.

[0094] Comparative Example 1 The only difference from Example 2 is that: neither the inner nor outer surface of the insulating substrate layer 21 has connecting blocks, and neither the surface of the flame-retardant heat dissipation layer 22 nor the wear-resistant reinforcement layer 23 has connecting grooves. That is, the flame-retardant heat dissipation layer 22 and the wear-resistant reinforcement layer 23 are directly coated and adhered to the inner and outer surfaces of the insulating substrate layer 21, without forming a mechanical interlocking structure. The misaligned arrangement of the first connecting block 211 and the second connecting block 212 is also absent. All other structures, material ratios (including corona treatment), and preparation methods are the same as in Example 2.

[0095] Comparative Example 2 The only difference from Example 2 is that the two sides of the insulating substrate layer 21 were not corona treated. That is, Comparative Example 2 is exactly the same as Example 1. (Note: Comparative Example 2 is Example 1, used to compare with Example 2 and verify the effect of corona treatment; for clarity, it is listed separately as Comparative Example 2 here).

[0096] Comparative Example 3 The only difference from Example 2 is that the ceramicized silicone foam 3 is not filled between the cable core 1 and the cable sheath 2; the cable core 1 is directly located inside the cavity of the cable sheath 2. All other structures, material ratios (including corona treatment and interlocking block structure), and preparation methods are the same as in Example 2.

[0097] Comparative Example 4 The only difference from Example 2 is that the outer surface of the wear-resistant reinforcing layer 23 does not have protrusions 232 and grooves 233, and the outer surface is a smooth surface. The rest of the structure, material ratio (including corona treatment, interlocking structure) and preparation method are the same as in Example 2.

[0098] Comparative Example 5 The only difference from Example 2 is that the cross-section of the first connecting block 211 and the second connecting block 212 is a rectangular structure (instead of an isosceles trapezoidal structure), that is, the width of the blocks remains unchanged along the direction away from the insulating substrate layer 21. The remaining structure, material ratio (including corona treatment), and preparation method are the same as in Example 2.

[0099] Comparative Example 6 The only difference from Example 2 is that the multiple first connecting blocks 211 and the multiple second connecting blocks 212 are not misaligned; that is, the first connecting blocks 211 and the second connecting blocks 212 are aligned at the same radial position on the insulating substrate layer 21. The remaining structure, material ratios (including corona treatment), and preparation methods are the same as in Example 2.

[0100] Comparative Example 7 The only difference from Example 2 is that halloysite nanotubes and hexagonal aluminum phosphate are not added to the components of ceramicized silicone foam 3. Specifically, ceramicized silicone foam 3 comprises the following components in parts by weight: 35 parts vinyl silicone oil, 15 parts silica, 35 parts nano-aluminum nitride powder, 0.5 parts ethynylcyclohexanol, 5 parts hydrogen-containing silicone oil, 5 parts hydroxyl silicone oil, and 0.5 parts platinum catalyst. The remaining structure and preparation method are the same as in Example 2.

[0101] The power cables prepared in Examples 1-4 and Comparative Examples 1-7 were subjected to the following performance tests: (1) Interlayer peel strength test: Samples were taken from the cable sheath and the T-type peel strength between the flame-retardant heat dissipation layer and the insulating substrate layer (inner layer peel strength) and between the wear-resistant reinforcement layer and the insulating substrate layer (outer layer peel strength) were tested using a universal testing machine in accordance with GB / T 2791-1995 (test method for T-peel strength of adhesives). The tensile speed was 100 mm / min and the strip width was 25 mm.

[0102] (2) Bending resistance test: The power cable samples were subjected to bending tests according to the bending test method in Appendix GB / T 12706.1-2020. The bending radius was 6 times the outer diameter of the cable, and the bending speed was 30 times per minute. The criterion for judgment was whether visible cracks, delamination, or breakage appeared in the cable sheath after 10,000 bends. The appearance of the sheath was recorded when the number of bends reached 10,000. The number of bends at which the first visible crack appeared was also recorded.

[0103] (3) Wear resistance test: Samples were taken from the outer surface of the wear-resistant reinforcement layer and the wear amount of the wear-resistant reinforcement layer was tested using a Taber abrasion tester in accordance with GB / T1768-2006. The load was 1000g, and the mass loss was measured after rotating 1000 revolutions with a CS-17 grinding wheel.

[0104] (4) Impact strength test: Take a sample from the cable sheath and perform a notched impact strength test on a simply supported beam in accordance with GB / T 1043.1-2008. The sample size is 80mm×10mm×4mm.

[0105] (5) Heat resistance and flame retardant performance testing: - Limiting Oxygen Index (LOI): The cable sheath material is made into a test sample with a size of 100mm×6.5mm×3mm, and the limiting oxygen index is tested in accordance with GB / T 2406.2-2009.

[0106] - Fire resistance test: The power cable sample was subjected to a fire resistance test in accordance with GB / T 19216.21-2003. After being burned with a flame at 950~1000℃ for 90 minutes, the cable was tested to see if it could still maintain the integrity of the circuit (i.e. whether the flame penetrated the sheath and foam layer to reach the core wire).

[0107] - Ceramicized foam cell structure retention rate: After calcining the ceramicized silicone foam sample in a muffle furnace at 1000℃ for 30 min, the sample was taken out and observed by scanning electron microscope (SEM) and the cell structure retention rate was calculated (cell retention rate = number of identifiable cells after calcination / number of cells before calcination × 100%).

[0108] (6) Thermal conductivity test: Take a sample from the flame-retardant heat dissipation layer of the cable sheath and test the thermal conductivity using the heat flow meter method according to GB / T 10295-2008.

[0109] Table 1. Test results of interlayer peel strength and flexural strength of the examples and comparative examples. project Inner layer peel strength (N / mm) Outer layer peel strength (N / mm) Sheath condition after 10,000 bends Number of bends at the first crack Example 1 4.2 4.5 No cracks, no delamination >10000 Example 2 6.8 7.1 No cracks, no delamination >10000 Example 3 6.5 6.8 No cracks, no delamination >10000 Example 4 7.0 7.3 No cracks, no delamination >10000 Comparative Example 1 3.1 3.3 Partial delamination 3200 Comparative Example 2 4.2 4.5 No cracks, no delamination >10000 Comparative Example 3 6.7 7.0 No cracks, no delamination >10000 Comparative Example 4 6.8 7.1 No cracks, no delamination >10000 Comparative Example 5 5.3 5.6 No cracks, slight delamination 8600 Comparative Example 6 5.9 6.2 No cracks, no delamination 9200 Comparative Example 7 6.8 7.1 No cracks, no delamination >10000 Table 2. Test results of wear resistance and impact strength of the examples and comparative examples. project Wear amount (mg / 1000 rpm) Impact strength (kJ / m²) Example 1 18.5 45.2 Example 2 18.3 45.5 Example 3 19.1 42.3 Example 4 17.8 48.7 Comparative Example 1 18.4 35.8 Comparative Example 2 18.5 45.2 Comparative Example 3 18.2 45.3 Comparative Example 4 24.7 38.6 Comparative Example 5 18.4 44.8 Comparative Example 6 18.3 42.1 Comparative Example 7 18.3 45.4 Table 3. Test results of heat resistance, flame retardancy, and thermal conductivity of the examples and comparative examples. project Limiting oxygen index (%) Results of flame burning at 950~1000℃ for 90 minutes Cell structure retention rate (%) Thermal conductivity (W / (m·K)) Example 1 38.2 The circuit was intact, and the flame did not penetrate it. 87.3 2.8 Example 2 38.3 The circuit was intact, and the flame did not penetrate it. 87.5 2.8 Example 3 37.8 The circuit was intact, and the flame did not penetrate it. 87.1 2.7 Example 4 39.1 The circuit was intact, and the flame did not penetrate it. 89.6 3.0 Comparative Example 1 38.1 The circuit was intact, and the flame did not penetrate it. 87.2 2.8 Comparative Example 2 38.2 The circuit was intact, and the flame did not penetrate it. 87.3 2.8 Comparative Example 3 37.5 The flame penetrated the sheath and reached the core wire area. — 2.7 Comparative Example 4 38.2 The circuit was intact, and the flame did not penetrate it. 87.4 2.8 Comparative Example 5 38.2 The circuit was intact, and the flame did not penetrate it. 87.3 2.8 Comparative Example 6 38.3 The circuit was intact, and the flame did not penetrate it. 87.4 2.8 Comparative Example 7 35.6 The flame penetrated the foam layer and reached the core wire. 31.2 2.8 The analysis of the above experimental results is as follows: (a) Comparative analysis between the examples and the comparative examples 1. Comparing Example 2 with Comparative Example 1, it can be seen that: The only difference between Comparative Example 1 and Example 2 is the absence of the mechanical interlocking structure of the connecting block and connecting slot. As shown in Table 1, the inner layer peel strength of Comparative Example 1 is 3.1 N / mm, and the outer layer peel strength is 3.3 N / mm, representing reductions of 54.4% and 53.5% respectively compared to Example 2. Comparative Example 1 developed its first crack after 3200 bends and showed partial delamination after 10000 bends, while Example 2 showed no cracks or delamination after 10000 bends. Table 2 shows that the impact strength of Comparative Example 1 is 35.8 kJ / m², a reduction of 21.3% compared to 45.5 kJ / m² in Example 2. These results clearly demonstrate that the mechanical interlocking structure formed by the connecting block and connecting slot significantly enhances the bonding force between layers and the overall mechanical properties, effectively preventing interlayer delamination and greatly improving the bending resistance and impact strength of the cable sheath.

[0110] 2. Comparing Example 2 with Comparative Example 2 / Example 1, it can be seen that: The only difference between Comparative Example 2 (i.e., Example 1) and Example 2 is that the insulating substrate layer was not corona treated. As shown in Table 1, the inner peel strength of Comparative Example 2 was 4.2 N / mm, and the outer peel strength was 4.5 N / mm, representing decreases of 38.2% and 36.6% respectively compared to Example 2. Neither exhibited cracks or delamination after 10,000 bending cycles, indicating that a certain level of interlayer bonding can be guaranteed by mechanical interlocking alone. However, judging from the peel strength values, the addition of corona treatment increased the interlayer bonding by approximately 60%. This verifies that corona treatment generates active hydrogen on the PA66 surface, which reacts chemically with the -NCO groups of the isoflurane diisocyanate adhesive to form chemical bonds. Furthermore, it increases the physical contact area through surface roughening, achieving a dual anti-delamination mechanism of "chemical bonding + physical-mechanical interlocking," significantly enhancing interlayer bonding.

[0111] 3. Comparing Example 2 and Comparative Example 3, it can be seen that: The only difference between Comparative Example 3 and Example 2 is that Comparative Example 3 does not use ceramicized silicone foam. As shown in Table 3, the limiting oxygen index of Comparative Example 3 is 37.5%, slightly lower than the 38.3% of Example 2. More importantly, in the fire resistance test of 950-1000°C flame burning for 90 minutes, the flame in Comparative Example 3 penetrated the sheath and reached the core wire area, compromising the integrity of the circuit; while in Example 2, the flame did not penetrate the sheath and foam layer, maintaining the integrity of the circuit. This fully demonstrates that ceramicized silicone foam provides a crucial fire-resistant barrier between the cable core wire and the cable sheath. At high temperatures, it rapidly forms a foam ceramic body, effectively isolating the transfer of flame and heat, playing a vital role in improving the heat resistance and flame retardant performance of power cables.

[0112] 4. Comparing Example 2 and Comparative Example 4, it can be seen that: The only difference between Comparative Example 4 and Example 2 is that the outer surface of the wear-resistant reinforcing layer does not have protrusions and grooves, and is a smooth surface. As shown in Table 2, the wear rate of Comparative Example 4 is 24.7 mg / 1000 rpm, an increase of 35.0% compared to 18.3 mg / 1000 rpm in Example 2; the impact strength of Comparative Example 4 is 38.6 kJ / m², a decrease of 15.2% compared to 45.5 kJ / m² in Example 2. These results demonstrate that the alternating protrusion and groove structure on the outer surface of the wear-resistant reinforcing layer can effectively disperse external impact stress, improving the wear resistance and impact resistance of the outer surface. The protrusion structure first contacts the external impactor and disperses the impact force, while the groove area provides deformation buffer space. The synergistic effect of both forms a structural reinforcement effect, significantly improving the overall protective performance of the wear-resistant reinforcing layer.

[0113] 5. Comparing Example 2 and Comparative Example 5, it can be seen that: The only difference between Comparative Example 5 and Example 2 is that the cross-sections of the first and second connecting blocks are rectangular (not isosceles trapezoidal). As shown in Table 1, the inner layer peel strength of Comparative Example 5 is 5.3 N / mm, and the outer layer peel strength is 5.6 N / mm, representing reductions of 22.1% and 21.1% respectively compared to Example 2. Comparative Example 5 developed its first crack after 8600 bends and exhibited slight delamination after 10000 bends, while Example 2 showed no cracks or delamination after 10000 bends. These results demonstrate that the isosceles trapezoidal cross-section connecting blocks (wedge-shaped structure, wider at the outside and narrower at the inside) have significant advantages over rectangular cross-sections. The "dovetail" self-locking effect formed by the isosceles trapezoidal structure ensures that the widened head of the block is held in place by the inner wall of the slot after insertion, resulting in greater resistance to peeling when external force attempts to detach the functional layer from the substrate layer. When subjected to peeling force, the rectangular cross-section block relies solely on the friction of the sidewalls to resist detachment, resulting in a weak self-locking effect. Consequently, its interlayer bonding strength and bending resistance are significantly lower than those of the isosceles trapezoidal cross-section design.

[0114] 6. Comparing Example 2 and Comparative Example 6, it can be seen that: The only difference between Comparative Example 6 and Example 2 is that the first and second connecting blocks are aligned at the same radial position on the insulating substrate layer (the blocks are not misaligned). As shown in Table 1, the inner layer peel strength of Comparative Example 6 is 5.9 N / mm, and the outer layer peel strength is 6.2 N / mm, representing decreases of 13.2% and 12.7% respectively compared to Example 2. Comparative Example 6 exhibits its first crack after 9200 bending cycles, a decrease compared to Example 2's greater than 10000 cycles. As shown in Table 2, the impact strength of Comparative Example 6 is 42.1 kJ / m², a decrease of 7.5% compared to Example 2's 45.5 kJ / m².

[0115] The above results demonstrate that the misalignment of the first and second connecting blocks has a significant impact on the overall performance of the cable sheath. When the inner and outer blocks are aligned, the insulation substrate layer has both inner and outer blocks on the same radial section, resulting in the effective wall thickness of the insulation substrate layer at that section being weakened from both sides, forming a weak section. Under bending or impact loads, this becomes a stress concentration point, easily initiating and propagating cracks, and ultimately leading to delamination. However, with the misalignment, the insulation substrate layer has blocks on only one side of any radial section, while the other side maintains its full wall thickness. This avoids simultaneous weakening of the wall thickness, ensuring the uniformity of the insulation substrate layer's structural strength and resulting in superior overall mechanical properties.

[0116] 7. Comparing Example 2 and Comparative Example 7, it can be seen that: The only difference between Comparative Example 7 and Example 2 is that halloysite nanotubes and hexagonal aluminum phosphate are not added to the ceramicized silicone foam. As shown in Table 3, the limiting oxygen index of Comparative Example 7 is 35.6%, a decrease of 2.7 percentage points compared to 38.3% in Example 2. In the fire resistance test of 950–1000°C flame burning for 90 minutes, the flame of Comparative Example 7 penetrated the foam layer and reached the core wire, destroying the circuit integrity. More importantly, the cell structure retention rate of Comparative Example 7 is only 31.2%, far lower than the 87.5% of Example 2.

[0117] The above results fully demonstrate the crucial roles of halloysite nanotubes and hexagonal aluminum phosphate in ceramicized silicone foam. Hexagonal aluminum phosphate, acting as a ceramicizing agent, can undergo a solid-state sintering reaction with silica and nano-aluminum nitride produced by the thermal decomposition of silicone rubber at high temperatures, promoting the transformation of silicone rubber into a hard ceramic body and forming a self-supporting ceramic skeleton with a certain mechanical strength. Halloysite nanotubes, acting as a pore structure stabilizer, with their unique hollow tubular nanostructure, serve as a micro-skeleton during high-temperature ceramicization, enhancing the stability of the pore structure and preventing pore collapse at high temperatures. The synergistic effect of these two components allows the ceramicized silicone foam to rapidly form a self-supporting foam ceramic body with a high pore retention rate when subjected to high temperatures or direct flame burning, effectively isolating the transfer of flame and heat. Without these two key components, silicone rubber foam cannot form an effective ceramicized structure at high temperatures, resulting in significant pore collapse (retention rate of only 31.2%), material pulverization or even disintegration, loss of heat insulation and flame retardant functions, and allowing flames to penetrate the foam layer and reach the core wire.

[0118] (II) Comparative Analysis of Various Embodiments As can be seen from the data in Tables 1 to 3, Examples 1 to 4 all exhibited excellent overall performance.

[0119] Example 1 (without corona treatment and a mechanically interlocked structure) has an inner layer peel strength of 4.2 N / mm, an outer layer peel strength of 4.5 N / mm, no cracks or delamination after 10,000 bending cycles, an impact strength of 45.2 kJ / m², a limiting oxygen index of 38.2%, passes the fire resistance test, has a cell structure retention rate of 87.3%, and a thermal conductivity of 2.8 W / (m·K).

[0120] Example 2 (based on Example 1 with added corona treatment) showed an inner layer peel strength of 6.8 N / mm and an outer layer peel strength of 7.1 N / mm, representing increases of 61.9% and 57.8% respectively compared to Example 1. This fully verifies the significant improvement effect of corona treatment on interlayer bonding. Other performance indicators of Example 2 were basically the same as those of Example 1, indicating that corona treatment primarily improves interlayer bonding and has no significant negative impact on other properties such as flame retardancy and thermal conductivity.

[0121] Examples 3 (thinner layer thicknesses) and 4 (thicker layer thicknesses) represent the lower and upper limits of the thickness range recommended by this invention, respectively. The impact strength of Example 3 is 42.3 kJ / m², slightly lower than 45.5 kJ / m² of Example 2 and 48.7 kJ / m² of Example 4. This is because the thinner layers result in a smaller total material volume, but it still maintains a good level. Example 4 has the highest impact strength of 48.7 kJ / m², and its limiting oxygen index of 39.1%, cell structure retention rate of 89.6%, and thermal conductivity of 3.0 W / (m·K) are all optimal values ​​among the examples. This is mainly due to the increased total material volume resulting from the increased thickness of each functional layer and the increased amount of each functional component in the ceramicized silicone foam. However, it should be noted that increasing the thickness of each layer also leads to an increase in the overall diameter and weight of the cable, affecting flexibility and economy. Therefore, in practical applications, a reasonable selection should be made based on the usage scenario.

[0122] Examples 1-4 showed no cracks or delamination after 10,000 bends, and the flames did not penetrate the sheath and foam layer in the fire resistance test at 950-1000℃, which fully demonstrates that all embodiments of the present invention can meet the stringent requirements for bending resistance and heat resistance and flame retardancy.

[0123] In summary, this invention achieves comprehensive performance improvements in power cables in terms of heat resistance, flame retardancy, high strength, wear resistance, bending resistance, anti-delamination, and long lifespan through the synergistic application of multiple technical means, including multi-layer composite structure design, mechanically interlocked anti-delamination layer structure, corona treatment chemical bonding, ceramicized silicone foam filling, and wear-resistant reinforcing layer surface structure strengthening. The experimental data from each embodiment confirm the technical effects of each inventive point of this invention, and the experimental data from each comparative example verify the irreplaceability and necessity of each technical feature.

[0124] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A heat resistant, flame retardant, multi-functional power supply cable, characterized by, The power cable includes a cable core and a cable sheath wrapped around the outer surface of the cable core, with ceramicized silicone foam filling the space between the cable core and the cable sheath. The cable sheath includes an insulating substrate layer, a flame-retardant and heat-dissipating layer disposed on the inner surface of the insulating substrate layer, and a wear-resistant reinforcing layer disposed on the outer surface of the insulating substrate layer. The inner surface of the insulating substrate layer is provided with a plurality of first connecting blocks, and the surface of the flame-retardant heat dissipation layer in contact with the insulating substrate layer is provided with a plurality of first connecting slots that fit into the first connecting blocks; the outer surface of the insulating substrate layer is provided with a plurality of second connecting blocks, and the surface of the wear-resistant reinforcement layer in contact with the insulating substrate layer is provided with a plurality of second connecting slots that fit into the second connecting blocks; the plurality of first connecting blocks and the plurality of second connecting blocks are staggered along the circumference of the insulating substrate layer.

2. The heat-resistant and flame-retardant multifunctional power cable according to claim 1, characterized in that, The cross-sections of the first connecting block and the second connecting block are both isosceles trapezoidal structures, and the width of the cross-sections of the first connecting block and the second connecting block gradually increases in the direction away from the insulating substrate layer; And / or, the angle α1 between the side of the first connecting block and the horizontal plane of the insulating substrate layer satisfies the relationship: 45°≤α1≤65°; the angle α2 between the side of the second connecting block and the horizontal plane of the insulating substrate layer satisfies the relationship: 45°≤α2≤65°.

3. The heat-resistant and flame-retardant multifunctional power cable according to claim 1, characterized in that, The outer surface of the wear-resistant reinforcement layer is provided with a plurality of alternating and spaced protrusions and grooves. The height h of the protrusions, the depth d of the grooves and the total thickness H of the wear-resistant reinforcement layer satisfy the following relationship: 1 / 3H≤h≤1 / 2H, 1 / 3H≤d≤1 / 2H. And / or, the ratio of the height of the first connecting block to the thickness of the flame-retardant heat dissipation layer is D1, where D1 satisfies the relationship: 1 / 3≤D1≤2 / 3; the ratio of the height of the second connecting block to the thickness of the wear-resistant reinforcement layer is D2, where D2 satisfies the relationship: 1 / 3≤D2≤2 / 3; And / or, the thickness of the insulating substrate layer is 2~6mm; the thickness of the flame-retardant heat dissipation layer is 1~3mm; and the thickness of the wear-resistant reinforcement layer is 1~3mm.

4. The heat-resistant and flame-retardant multifunctional power cable according to claim 1, characterized in that, The insulating substrate layer is made of PA66, and both sides of the insulating substrate layer are corona treated to form a rough surface with unevenness; the voltage of the corona treatment is 2.0~2.2kV, the current is 8A, the corona velocity is 40~50m / min, and the treatment time is 8~10s.

5. The heat-resistant and flame-retardant multifunctional power cable according to claim 4, characterized in that, The flame-retardant heat dissipation layer comprises beryllium oxide, polyethylene glycol, and isoflurane diisocyanate adhesive, wherein the mass ratio of beryllium oxide, polyethylene glycol, and isoflurane diisocyanate adhesive is (2~4):(1~2):(4~8); the average relative molecular mass of polyethylene glycol is 18000~19000, and its phase transition temperature is 60~64℃.

6. The heat-resistant and flame-retardant multifunctional power cable according to claim 5, characterized in that, In the flame-retardant heat dissipation layer, the average particle size of the isoflurane diisocyanate adhesive is d1, the average particle size of the polyethylene glycol is d2, and the average particle size of the beryllium oxide is d3; d1 is greater than d2 and d3 respectively, and d1 / d2=(2~10):1, d1 / d3=(2~10):1; wherein d1 is 0.5~10μm, and d2 and d3 are 0.05~5μm respectively.

7. The heat-resistant and flame-retardant multifunctional power cable according to claim 4, characterized in that, The wear-resistant reinforcing layer comprises cubic boron nitride, quartz fiber and isoflurane diisocyanate adhesive, wherein the mass ratio of cubic boron nitride, quartz fiber and isoflurane diisocyanate adhesive is (2~4):(1~2):(4~8).

8. The heat-resistant and flame-retardant multifunctional power cable according to claim 7, characterized in that, In the wear-resistant reinforcing layer, the average particle size of the isoflurane diisocyanate adhesive is d1, the average particle size of the cubic boron nitride is d4, and the average diameter of the quartz fiber is d5; d1 is greater than d4 and d5 respectively, and d1 / d4=(2~10):1, d1 / d5=(2~10):1; wherein d1 is 0.5~10μm, and d4 and d5 are 0.05~5μm respectively.

9. The heat-resistant and flame-retardant multifunctional power cable according to claim 1, characterized in that, The ceramicized silicone foam comprises the following components in parts by weight: 30-40 parts vinyl silicone oil, 10-20 parts silica, 20-50 parts nano aluminum nitride powder, 0.1-1.0 parts ethynylcyclohexanol, 1-10 parts hydrogen-containing silicone oil, 1-10 parts hydroxyl silicone oil, 0.1-1.0 parts platinum catalyst, 10-20 parts hexagonal aluminum phosphate, and 1-8 parts halloysite nanotubes; The preparation method of the ceramicized silicone foam includes the following steps: S1. Add the vinyl silicone oil, silica, nano aluminum nitride powder and hexagonal aluminum phosphate to a kneader, knead into a ball at 100~150℃, cool, and obtain the base adhesive. S2. Stir the hydroxyl silicone oil and halloysite nanotubes at a speed of 23000~26000 r / min for 10~25s to obtain a foamed mixture; S3. Add the foaming mixture, ethynylcyclohexanol, hydrogen-containing silicone oil and platinum catalyst to the base adhesive, mix evenly, and obtain the adhesive material. S4. The rubber material is vulcanized and foamed using casting, calendering or molding processes to obtain the ceramicized silicone foam.

10. A method for manufacturing a heat-resistant and flame-retardant multifunctional power cable as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Prepare the insulating substrate layer: The insulating substrate layer material is prepared into a tubular structure by extrusion molding process. Multiple first connecting blocks are formed on the inner surface of the tubular structure, and multiple second connecting blocks are formed on the outer surface of the tubular structure. The multiple first connecting blocks and the multiple second connecting blocks are staggered along the circumferential direction. Step 2: Prepare the flame-retardant heat dissipation layer: The flame-retardant heat dissipation layer material is formed on the inner surface of the insulating substrate layer by molding or coating process, so that the first connecting groove on the surface of the flame-retardant heat dissipation layer is fitted with the first connecting block; Step 3: Prepare the wear-resistant reinforcement layer: The wear-resistant reinforcement layer material is formed on the outer surface of the insulating substrate layer by molding or coating process, so that the second connecting groove on the surface of the wear-resistant reinforcement layer is fitted with the second connecting block, and multiple alternating and spaced protrusions and grooves are formed on the outer surface of the wear-resistant reinforcement layer to obtain the cable sheath; Step 4: Prepare ceramicized silicone foam and wrap the ceramicized silicone foam around the outer surface of the cable core wire; Step 5: Insert the cable core wire covered with ceramicized silicone foam into the cable sheath, so that the ceramicized silicone foam fills the space between the cable core wire and the cable sheath, thus obtaining the heat-resistant and flame-retardant multifunctional power cable.

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