High-flexibility flame-retardant cable for new energy vehicles

Abstract

The utility model discloses a new energy vehicle with high flexible flame -retardant cable, including conductor, the outside of conductor is equipped with the protection layer, the outside of protection layer is equipped with insulating layer, the outside of insulating layer is equipped with the shielding layer, the outside of shielding layer is equipped with the sheath layer. The conductor adopts high -strength aluminum alloy wire bundle silk to make, through the multilayer compound twist and form. The utility model discloses, through aluminum alloy conductor adopts bundle twist + layer twisting process, and adopts superfine wire, can promote breaking elongation and bending life, also can restrain the skin effect, enhances high -frequency current -carrying capacity, and superfine wire structure can reduce bending radius, and the conductor is coated with lubricating oil outside, and the further extension of bending cycle life is protected by the self -lubricating polyester belt layer, and the sheath is extruded through half -extrusion pipe type mould, reduces the friction coefficient and wiring tension, and insulation, sheath all use low friction TPV material of oxygen index 32%, and improve the wear resistance of cable.

Description

Technical Field

[0001] This utility model mainly relates to the field of new energy vehicle technology, specifically a highly flexible flame-retardant cable for new energy vehicles. Background Technology

[0002] Global sales of new energy vehicles are projected to exceed 40 million units by 2030 (CAGR 25%+), with China accounting for over 50% (Ministry of Industry and Information Technology's "New Energy Vehicle Industry Development Plan (2021-2035)"). Among these, the cable demand for 800V high-voltage platform models (such as BYD, XPeng, and Porsche Taycan) is 30%-50% higher than that for 400V systems. Regarding the performance requirements of cables for new energy vehicles, China's "Safety Requirements for Electric Vehicles" (GB18384-2020) mandates that high-voltage cables have a flame retardant rating of ≥VW-1.

[0003] Current new energy vehicle cables typically use heavy copper conductors and aluminum alloy conductors, which are prone to metal fatigue from prolonged bending, leading to conductor breakage. Furthermore, the friction between the conductor and insulation layer during cable bending reduces insulation performance, and insulation wear may cause excessive partial discharge, affecting safety during use. Utility Model Content

[0004] This utility model provides a solution that is significantly different from existing technologies, addressing the problem that existing solutions are too simplistic. It mainly provides a highly flexible flame-retardant cable for new energy vehicles, which solves the technical problems mentioned in the background art. Traditional copper conductors of new energy vehicle cables are heavy, and aluminum alloy conductors have poor flexibility. Long-term bending can easily lead to metal fatigue and breakage. Furthermore, when the cable is bent, the conductor and insulation layer rub against each other, which can easily lead to a decrease in insulation performance and wear, and may cause partial discharge to exceed the limit, threatening the safety of use.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: A highly flexible flame-retardant cable for new energy vehicles includes a conductor, a protective layer on the outside of the conductor, an insulation layer on the outside of the protective layer, a shielding layer on the outside of the insulation layer, and a sheathing layer on the outside of the shielding layer.

[0006] The conductor is made of high-strength aluminum alloy wire bundles, which are formed by multiple layers of twisting. The center layer is a single straight strand, the outermost layer is twisted to the left, the adjacent layers are twisted in opposite directions, and the outer layer of the conductor is coated with silicone oil lubricant. The high-strength aluminum alloy wire is drawn by a wire drawing machine and then twisted by a frame stranding machine through a 1+6+12+…… regular twisting process.

[0007] More preferably, the protective layer material is a self-lubricating polyester tape, which is overlapped and wrapped around the outside of the conductor with an overlap rate of 15-20%, and its wrapping direction is opposite to the twisting direction of the outermost layer of the conductor.

[0008] More preferably, the insulating layer material is a high flame-retardant TPV elastomer insulating material, which is a TPV material with a low coefficient of friction, a hardness of 80A, and an oxygen index of 32%.

[0009] More preferably, the shielding layer consists of a braided shield and a wrapped shield, wherein the braided shielding material is made of tin-plated copper wire, and the wrapped shielding material is made of aluminum-plastic tape and is wrapped around the outside of the braided shield.

[0010] More preferably, the sheath material is a high flame-retardant TPV elastomer sheath material, which is a TPV material with an oxygen index ≥32% and a hardness of 90A, and a thickness of 1.6 to 1.8 mm.

[0011] More preferably, the TPV materials used in the insulation layer and the sheath layer both contain 10%-20% magnesium hydroxide flame retardant and 2.5%-3% carbon nanotubes.

[0012] More preferably, the diameter of the high-strength aluminum alloy wire after being drawn by the wire drawing machine is 0.30mm±0.02mm.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: This highly flexible flame-retardant cable utilizes a bundled and layered stranding process with aluminum alloy conductors. The single filament diameter is 0.30mm ± 0.003mm, which improves conductor elongation at break and bending life compared to traditional cables. Furthermore, layered stranding suppresses the skin effect, enhancing high-frequency current carrying capacity. The ultra-fine filament structure reduces the bending radius, making it suitable for use in new energy vehicles. The conductor is coated with lubricating oil, and a self-lubricating polyester tape protective layer is used with a reverse wrapping process to eliminate torque superposition with the conductor. A 15-20% overlap rate forms a continuous lubrication interface, and the ≤2N low-tension wrapping maintains material elasticity, thereby improving bending cycle life. The sheath is extruded using a semi-extrusion die, reducing the coefficient of friction and lowering wiring tensile force to meet customer peel force requirements. It also uses a low-friction coefficient, 32% oxygen index TPV material, with a sheath hardness of 90A and an insulation hardness of 80A, improving the cable's abrasion resistance.

[0014] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the full cross-section of the present invention.

[0016] Numbering on the map: 1. Conductor; 2. Protective layer; 3. Insulating layer; 4. Shielding layer; 401. Braided shielding; 402. Wrapped shielding; 5. Sheath layer. Detailed Implementation

[0017] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, which show several embodiments of the utility model. However, the utility model can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the utility model more thorough and comprehensive.

[0018] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0019] Please refer to the appendix carefully. Figure 1 A highly flexible flame-retardant cable for new energy vehicles includes a conductor 1, a protective layer 2 on the outside of the conductor 1, an insulation layer 3 on the outside of the protective layer 2, a shielding layer 4 on the outside of the insulation layer 3, and a sheath layer 5 on the outside of the shielding layer 4.

[0020] Conductor 1 is made of high-strength aluminum alloy wire bundles, which are formed by multiple layers of twisting. The center layer is a single straight strand, the adjacent layers are twisted in opposite directions, and the outermost layer is twisted to the left. Conductor 1 is coated with silicone oil lubricant, and the diameter of a single wire is 0.30mm ± 0.003mm. The twisting pitch ratio of the second outermost layer strands is controlled at 18 to 22 times, and the twisting pitch ratio of the outermost layer is controlled at 12 to 14 times.

[0021] In this embodiment, as Figure 1 As shown, the protective layer 2 is made of self-lubricating polyester tape. The thickness of a single layer of self-lubricating polyester tape is 0.03-0.04 mm. The self-lubricating polyester tape is wrapped around the outside of conductor 1 with an overlap rate of 15%-20% and a wrapping tension of ≤2N. The wrapping direction is opposite to the twisting direction of the outermost layer of conductor 1, thereby reducing stress concentration.

[0022] Through the above structure, the polyester material has excellent mechanical strength and weather resistance, which can provide stable and reliable physical protection for the conductor 1; at the same time, the self-lubricating properties can reduce the coefficient of friction between the protective layer 2 and the conductor 1 and during the use of the protective layer 2, reduce wear caused by friction, and improve the stability of the overall structure.

[0023] In this embodiment, as Figure 1As shown, the insulation layer 3 is made of high flame-retardant TPV elastomer insulation material. This material is a low friction coefficient TPV material with a hardness of 80A and an oxygen index ≥32%, which is a VW-1 flame-retardant rating.

[0024] Through the above structure, the low coefficient of friction of the insulation layer 3 reduces the frictional resistance between the insulation layer 3 and the protective layer 2 and shielding layer 4 during use, thereby reducing the wear of the insulation layer 3 caused by friction. The hardness of 80A gives it both good structural strength and moderate elasticity, which can withstand slight external impact and compression and maintain shape stability, while also being suitable for complex installation scenarios such as bending and torsion. The flame-retardant properties with an oxygen index of ≥32% and a VW-1 flame retardant rating enable it to inhibit the occurrence and spread of combustion, reduce the risk of fire, and prevent fire from spreading along the cable.

[0025] In this embodiment, as Figure 1 As shown, the shielding layer 4 is composed of a braided shield 401 and a wrapped shield 402. The braided shield 401 is made of tin-plated copper wire with a single wire diameter of 0.193±0.003mm and a braiding density of 85-87%. The wrapped shield 402 is made of aluminum-plastic tape with a single layer thickness of 0.03-0.04mm, and is wrapped around the outside of the braided shield 401 with an overlap rate of ≥20%.

[0026] Through the above structure, the shielding layer 4 adopts a double-layer structure combining braided shielding 401 and wrapped shielding 402, providing reliable protection for conductor 1 and insulation layer 3. The braided shielding 401 uses tin-plated copper wire, and the tin plating layer enhances the corrosion resistance of the copper wire and prevents oxidation and moisture from affecting the shielding effect. The precise specification of 0.193±0.003mm for a single wire diameter ensures the density of the braid while balancing the flexibility and structural strength of the shielding layer 4. The high braiding density of 85-87% can block the intrusion of external high-frequency electromagnetic waves and other interference signals. To prevent the electromagnetic signals of conductor 1 from radiating outwards and ensure stable and accurate signal transmission, the aluminum-plastic tape used in the wrapping shield 402 has an aluminum layer that can supplement the shortcomings of braided shield 401 in low-frequency interference shielding, improving the shielding effect. The plastic layer can play a role in insulation and short-circuit protection, and improve the material's bending resistance and tear resistance. The single-layer thickness of 0.03 to 0.04 mm enhances the shielding performance without excessively increasing the cable size and weight. The wrapping method with an overlap rate of ≥20% can eliminate shielding blind spots and improve the tensile strength of the shielding layer 4.

[0027] In this embodiment, as Figure 1 As shown, the sheath layer 5 is made of high flame-retardant TPV elastomer sheath material. This material is TPV material with an oxygen index ≥32% and a hardness of 90A.

[0028] Through the above structure, the hardness of 90A gives the outermost sheath layer 5 excellent impact resistance, compression resistance, and scratch resistance. It can directly resist external mechanical collisions, heavy object compression, and scratches from sharp objects, preventing damage to the inner shielding layer 4, insulation layer 3, protective layer 2, and conductor 1 due to external forces. At the same time, the elasticity of the TPV material provides a certain degree of flexibility, allowing it to meet bending and torsion requirements during the process, preventing the sheath layer from cracking and extending the cable's service life. Its flame-retardant properties with an oxygen index ≥32% can improve the cable's flame-retardant performance when combined with the inner insulation layer 3. The sheath layer 5 can inhibit the ignition of external open flames and prevent the fire from spreading inward. The insulation layer 3 can prevent the local high temperature generated by the short circuit of conductor 1 from igniting the surrounding structure, reducing the risk of fire.

[0029] In this embodiment, as Figure 1 As shown, the TPV materials used in the insulation layer 3 and the sheath layer 5 both contain 10%-20% magnesium hydroxide flame retardant and 2.5%-3% carbon nanotubes.

[0030] Through the above structure, the modified nano-sized magnesium hydroxide inhibits flame spread by absorbing heat and releasing water vapor to dilute oxygen upon thermal decomposition, and avoids the release of toxic and harmful gases by traditional halogenated flame retardants, thus achieving halogen-free flame retardancy. At the same time, the small particle size allows it to be uniformly dispersed in the substrate without affecting the material's flexibility, impact resistance and other mechanical properties. Carbon nanotubes form a continuous conductive path in the TPV material, which can conduct static charge on the cable surface and avoid static accumulation that may cause sparks or interfere with signals of precision equipment.

[0031] The cable manufacturing steps are as follows: Step 1: Wire drawing Purchase 9.5mm annealed aluminum alloy rods (6010 series), and use a wire drawing machine to draw the 6010 aluminum alloy to 0.30mm; the wire drawing die design is as follows: Die design for large aluminum drawing machine (aluminum alloy wire compression ratio is 18.5%):

[0032] Die design for medium-length aluminum drawing machine (aluminum alloy wire compression ratio 17.5%):

[0033] Small aluminum drawing machine mold design: (aluminum alloy wire compression ratio 15.5%)

[0034] Step 2: Conductor 1 bundle of wires The high-strength aluminum alloy wire (6010 series) of type 5 obtained in step one, with a single wire diameter of 0.30mm±0.02mm, is bundled in multiple layers (1+6+12+... structure, with adjacent layers twisted in opposite directions, and the outermost layer to the right) in a wire bundling machine.

[0035] Step 3: Strand the conductor into one strand The strands are made from the bundled single strands obtained in step two and are regularly stranded in a frame stranding machine (61 reels) using the 1+6+12+…… method. The stranding directions of adjacent layers are opposite, with the outermost layer to the left. The center layer is a single straight strand. The strand pitch ratio of the next outermost layer is controlled at 18 to 22 times, and the strand pitch ratio of the outermost layer is controlled at 12 to 14 times. After the last stranding process, a coating device is set to coat the outermost layer of conductor 1 with silicone oil lubricant.

[0036] Step 4: Annealing of Conductor 1 The conductor 1 was annealed using a trolley + hot air circulating furnace at a temperature of 340±10℃ for 6 hours.

[0037] Step 5: Wrap the protective layer 2 Self-lubricating polyester tape is used for wrapping, with the overlap rate controlled at 15-20%; the tension of the angled wrapping machine (40°-45°) is controlled at 1.5-2N.

[0038] Step 6: Extruding the insulation layer 3 The insulation material is a high flame-retardant elastomer (oxygen index ≥32%, VW-1 flame retardant rating) made of TPV material with low friction coefficient, hardness 80A, and 32% oxygen index. It is extruded using a semi-extrusion die on an SJ-90 extruder (the semi-extrusion die optimizes the bonding force between the sheath layer 5 and the shielding layer 4 by controlling the melt viscosity (temperature sensitive).

[0039] Insulation extrusion temperature strategy:

[0040] Explanation of the function of the temperature range (°C): Feeding section: Low temperature prevents raw materials from melting and clumping prematurely, ensuring stable feeding (especially when containing flame retardants); Compression section: The temperature is gradually increased to melt the TPV substrate, avoiding the thermal decomposition of magnesium hydroxide (decomposition temperature ≥340℃); Homogenization section: The filler is fully plasticized and uniformly dispersed (carbon nanotubes require high shear force, so the temperature in this section can be slightly higher). Neck: Moderate cooling reduces the risk of thermal degradation and maintains melt pressure; Die head: Stabilizes melt flow and prevents flame retardant sedimentation or carbon nanotube agglomeration; Die opening: slightly lower than the die head temperature to ensure extrusion molding stability and prevent material oxidation or surface cracking.

[0041] Step 7: Shielding layer 4 Depending on the cable's outer diameter, a 16-spindle or 24-spindle braiding machine is selected to prepare the braided layer (the wrapping head is located inside the braiding machine, and the braiding and wrapping are integrated into one process). The diameter of the braided single filament is 0.193±0.003mm, and the braiding density is 85-87%. An aluminum-plastic tape with a thickness of 0.03-0.04mm is overlapped on the outside of the braided shielding 401, and the overlap rate is controlled at 15-20%.

[0042] Step 8: Sheath Layer 5 The sheath layer 5 is made of TPV material with an oxygen index of 32% and a hardness of 90A. It is extruded through an extrusion die using an SJ-120 extruder, with a thickness of 1.6 to 1.8 mm. The extrusion temperature of the sheath layer 5 is ≤190℃ throughout the process to prevent damage to the EPDM crosslinking network. Segmented cooling is used to avoid internal stress in the material.

[0043] Sheath extrusion temperature strategy:

[0044] Explanation of the function of the temperature range (°C): Feeding section: Low-temperature feeding prevents pre-plasticization and avoids moisture absorption and clumping of the flame retardant (magnesium hydroxide is hygroscopic); Compression section: Gradually melt the TPV substrate and initiate dynamic shear dispersion of the filler (take care to avoid local overheating that could lead to EPDM crosslinking and degradation). Homogenization stage: Completely plasticizes and efficiently disperses carbon nanotubes (requires high shear force) to ensure uniform distribution of flame retardant; Neck: Appropriate cooling stabilizes the melt and reduces the impact of thermal history on heat resistance; Die head: Balances flowability and pressure to prevent carbon nanotube agglomeration or flame retardant phase separation; Die opening: Low-temperature shaping ensures surface smoothness and avoids the weather resistance of the sheath layer from decreasing due to high-temperature oxidation.

[0045] Segmented cooling strategy: The first water tank contains 65℃ warm water that is slowly cooled to reduce internal stress caused by sudden cooling.

[0046] The second water tank: further cooled to 50℃ to stabilize the crystal structure.

[0047] The third water tank: room temperature water is used for final cooling to ensure the dimensional stability of the sheath.

[0048] Cooling length ratio: allocated in a 2:1:1 ratio, such as 6m→3m→3m, to match thickness requirements.

[0049] The specific operating procedure of this utility model is as follows: Conductor 1 is made of high-strength aluminum alloy wire bundles twisted in multiple layers. The central layer is a single straight strand, the adjacent layers are twisted in opposite directions, the outermost layer is twisted to the left, and the twisting pitch ratio of the second outermost layer (18-22 times) and the outermost layer (12-14 times) offsets the internal stress and balances flexibility and tensile strength. The single wire diameter of 0.30mm±0.003mm reduces transmission gap loss. The silicone oil lubricant coated on the outer layer and the self-lubricating polyester tape of the protective layer 2 form a double lubrication structure. Combined with the annealing treatment in the trolley + hot air circulating furnace, internal stress is eliminated, which not only ensures efficient transmission of conductor 1 but also reduces interlayer friction and wear.

[0050] The protective layer 2 is a 0.03-0.04mm thick self-lubricating polyester tape, wrapped in reverse with a 15%-20% overlap rate and a tension of ≤2N on the outside of the conductor 1. The reverse wrapping offsets the stranding stress of the conductor 1, and the self-lubricating properties improve the compatibility with the insulation layer 3.

[0051] The insulation layer 3 uses a high flame-retardant TPV elastomer with a low coefficient of friction and a hardness of 80A. It contains 10%-20% magnesium hydroxide flame retardant with a particle size ≤1μm and 2.5%-3% carbon nanotubes. The magnesium hydroxide flame retardant can halogen-free flame retardant and suppress flames, while the carbon nanotubes can discharge static electricity and prevent interference. Together with the VW-1 flame retardant rating, it forms a flame-retardant defense line.

[0052] The shielding layer 4 consists of a 0.193±0.003mm tin-plated copper wire braided shield 401 with a braid density of 85-87% and a 0.03-0.04mm aluminum-plastic tape wrapped shield 402 with an overlap rate of ≥20%. The tin-plated copper wire braided shield 401 can resist high-frequency interference and corrosion, while the wrapped shield 402 can resist low-frequency shielding, provide insulation and short circuit protection, thus achieving full-band electromagnetic shielding while also taking into account flexibility.

[0053] The sheath layer 5 is made of high flame-retardant TPV elastomer with a hardness of 90A, containing the same magnesium hydroxide flame retardant and carbon nanotubes. As the outermost layer, it resists mechanical impact and scratches, and together with the insulation layer 3, it forms a flame-retardant structure, while also having weather resistance and flexibility.

[0054] Through the synergistic design of anisotropic stranded aluminum alloy conductor 1, reverse-wrapped self-lubricating polyester tape, TPV insulation with an oxygen index ≥32%, and TPV sheath, a comprehensive improvement in flexibility, fatigue resistance, flame retardancy, and lightweight is achieved.

[0055] The present invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. A highly flexible flame-retardant cable for new energy vehicles, comprising a conductor (1), characterized in that: The conductor (1) has a protective layer (2) on its outer side, an insulating layer (3) on its outer side, a shielding layer (4) on its outer side, and a sheath layer (5) on its outer side. The conductor (1) is made of multiple strands of high-strength aluminum alloy wire bundles twisted in multiple layers. The center layer is a single straight strand, the outermost layer is twisted to the left, the adjacent layers are twisted in opposite directions, and the outer layer of the conductor (1) is coated with silicone oil lubricant. The high-strength aluminum alloy wire is drawn by a wire drawing machine and then twisted by a frame stranding machine.

2. The highly flexible flame-retardant cable for new energy vehicles according to claim 1, characterized in that: The protective layer (2) is made of self-lubricating polyester tape, which is wrapped around the outside of the conductor (1) with an overlap rate of 15-20%, and its wrapping direction is opposite to the twisting direction of the outermost layer of the conductor (1).

3. The highly flexible flame-retardant cable for new energy vehicles according to claim 1, characterized in that: The insulating layer (3) is made of high flame retardant TPV elastomer insulating material, which is a TPV material with a low coefficient of friction, a hardness of 80A and an oxygen index of 32%.

4. The highly flexible flame-retardant cable for new energy vehicles according to claim 1, characterized in that: The shielding layer (4) is composed of a braided shield (401) and a wrapped shield (402). The braided shield (401) is made of tin-plated copper wire and the wrapped shield (402) is made of aluminum-plastic tape and wrapped around the outside of the braided shield (401).

5. A highly flexible flame-retardant cable for new energy vehicles according to claim 1, characterized in that: The sheath layer (5) is made of high flame retardant TPV elastomer sheath material. This material is TPV material with an oxygen index ≥32% and a hardness of 90A, and a thickness of 1.6 to 1.8 mm.

6. A highly flexible flame-retardant cable for new energy vehicles according to claim 1, characterized in that: The high-strength aluminum alloy wire has a diameter of 0.30mm ± 0.02mm after being drawn by a wire drawing machine.

Images