High-flexibility high-temperature-resistant fireproof cable

Abstract

The invention relates to the technical field of power cables, and discloses a high-flexibility high-temperature-resistant fireproof cable which comprises a conductor, an insulating layer, a shielding layer, an inner sheath layer, a fireproof layer and an outer sheath layer which are sequentially arranged from inside to outside, the conductor is formed by twisting multiple strands of fine copper wires, the surface of each fine copper wire is plated with a layer of tin, the insulating layer is made of a silicon rubber material, and the shielding layer is made of a silicon rubber material. A nanoscale magnesium hydroxide flame retardant and a high-temperature-resistant additive are added into the silicone rubber material; the shielding layer is a copper wire braided shielding layer; the inner sheath layer is made of a polyurethane material; the fireproof layer comprises a ceramic silicone rubber layer and a mica tape wrapping layer which are arranged in sequence; according to the scheme, the conductor is stranded by multiple strands of fine copper wires, and the diameter, the stranding pitch and the tension are optimized, so that the cable keeps excellent flexibility in frequent bending and moving environments, and the conductor is prevented from being broken. The tin coating improves the oxidation resistance and the welding performance, and ensures the long-term stability of electrical connection.

Description

Technical Field

[0001] The present application relates to the technical field of power cables, and in particular to a highly flexible, high-temperature-resistant and fire-resistant cable. Background Art

[0002] With the rapid development of industrial automation, intelligent buildings, aerospace, and other fields, the performance requirements for cables are becoming increasingly stringent. In many specialized working environments, such as high-temperature industrial production sites, fire protection systems, robotics, and aviation equipment, cables must simultaneously possess high flexibility, high-temperature resistance, and fire resistance. However, existing cable technologies struggle to meet these comprehensive performance requirements.

[0003] Regarding the aforementioned related technologies, the inventors believe that traditional cables typically utilize a single structural design, failing to balance multiple performance requirements. For example, conventional flexible cables use polyvinyl chloride (PVC) or polyethylene (PE) as insulation and sheath materials. While these materials offer excellent flexibility, they suffer from poor heat and fire resistance, easily softening and deforming in high-temperature environments, and can even cause fires. To improve heat resistance, some cables utilize fluoroplastics (such as FEP and PTFE) as insulation materials. However, these materials are inflexible, difficult to process, and expensive. Furthermore, existing fire-resistant cables often utilize magnesium oxide mineral insulation. While these materials offer excellent fire resistance, they are highly rigid and have a large bending radius, making them unsuitable for applications requiring frequent bending. Furthermore, the braided shielding layer's braid density and angles are poorly designed, resulting in poor shielding effectiveness and compromising cable flexibility. Furthermore, existing cables utilize a single material for both the inner and outer sheaths, making it difficult to simultaneously provide excellent mechanical protection, flexibility, and environmental performance. Therefore, developing a cable that simultaneously meets the requirements for high flexibility, heat resistance, fire resistance, electromagnetic shielding, and environmental protection is of great practical significance. Summary of the Invention

[0004] In order to solve the problems raised in the above background technology, the present application provides a highly flexible, high-temperature-resistant and fire-proof cable.

[0005] The present application provides a highly flexible, high-temperature-resistant and fire-resistant cable that adopts the following technical solutions:

[0006] A highly flexible, high-temperature-resistant and fire-resistant cable comprises a conductor, an insulating layer, a shielding layer, an inner sheath layer, a fireproof layer and an outer sheath layer, which are arranged in sequence from the inside to the outside. The conductor is formed by twisting multiple strands of fine copper wire, and the surface of each fine copper wire is plated with a layer of tin. The insulating layer is made of silicone rubber material, to which nano-magnesium hydroxide flame retardant and high-temperature-resistant additives are added. The shielding layer is a copper wire braided shielding layer. The inner sheath layer is made of polyurethane material. The fireproof layer comprises a ceramic silicone rubber layer and a mica tape wrapping layer arranged in sequence. The outer sheath layer is made of low-smoke, halogen-free and flame-retardant polyolefin material.

[0007] Preferably, the diameters of the multiple strands of fine copper wires inside the conductor are optimized, and the twisting pitch and tension are precisely controlled to enhance the flexibility of the conductor.

[0008] Preferably, the thickness of the insulating layer is reasonably designed according to the rated voltage and use environment of the cable.

[0009] Preferably, the copper wire braiding density of the copper wire braided shielding layer is precisely calculated to effectively shield external electromagnetic interference without affecting the flexibility of the cable.

[0010] Preferably, the thickness of the inner sheath layer is moderate, which can provide sufficient protection without affecting the overall flexibility of the cable. Plasticizer is added to the polyurethane inner sheath layer to further improve the flexibility of the inner sheath layer.

[0011] Preferably, the ceramic silicone rubber layer has good flexibility and elasticity at room temperature, and is rapidly ceramicized to form a hard ceramic body when exposed to high-temperature flames.

[0012] Preferably, the braiding angle of the copper wire braided shielding layer is - degrees to achieve the best electromagnetic shielding effect.

[0013] In summary, this application has the following beneficial technical effects:

[0014] 1. High Flexibility and Reliability: By utilizing multiple strands of fine copper wire, with optimized diameter, twist pitch, and tension, the cable maintains exceptional flexibility despite frequent bending and movement, preventing conductor breakage. A tinned layer enhances oxidation resistance and solderability, ensuring long-term electrical connection stability. A plasticizer added to the inner sheath further enhances flexibility while protecting the internal structure from mechanical damage. This design allows the cable to be used in applications requiring frequent bending, such as robotic joints and automated production lines.

[0015] 2. Excellent high-temperature and fire-resistant performance: The silicone rubber material of the insulation layer is infused with nano-magnesium hydroxide flame retardant and high-temperature resistant additives to maintain insulation performance at high temperatures. It also resists flames by decomposing to absorb heat and release water. The ceramic silicone rubber layer of the fireproof layer quickly forms a hard ceramic body in the event of a fire, preventing the spread of flames. The mica tape wrapping provides additional high-temperature protection, ensuring the cable continues to operate in high-temperature environments. This double-layer fireproof structure significantly improves the cable's fire resistance, meeting the safety requirements of fire protection systems and high-temperature industrial environments.

[0016] 3. Efficient electromagnetic shielding and environmental performance: The copper wire braided shield achieves optimal electromagnetic shielding while maintaining flexibility through precise calculation of braid density and controlled braid angles. This effectively protects against external electromagnetic interference and is suitable for electromagnetically sensitive applications such as medical equipment and precision instruments. The outer sheath is made of low-smoke, halogen-free, flame-retardant polyolefin material, which emits no toxic fumes during combustion, meeting environmental requirements and reducing the risk of casualties and equipment damage in fires. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the first overall structure of the embodiment of the application.

[0018] Figure 2 It is a second overall structural diagram of the application embodiment.

[0019] Figure 3 yes Figure 1 A magnified schematic diagram of the structure in the middle.

[0020] Explanation of the accompanying symbols: 1. Conductor; 2. Insulation layer; 3. Shielding layer; 4. Inner sheath layer; 5. Fireproof layer; 501. Ceramic silicone rubber layer; 502. Mica tape wrapping layer; 6. Outer sheath layer. DETAILED DESCRIPTION

[0021] The following is combined with Figure 1-3 This application is described in further detail.

[0022] The present application discloses a highly flexible, high temperature resistant and fireproof cable. Figure 1-3 , including a conductor 1, an insulating layer 2, a shielding layer 3, an inner sheath layer 4, a fireproof layer 5 and an outer sheath layer 6 arranged in sequence from the inside to the outside. The conductor 1 is made of multiple strands of fine copper wire, and the surface of each fine copper wire is plated with a layer of tin. The insulating layer 2 is made of silicone rubber material, and the silicone rubber material is added with nano-magnesium hydroxide flame retardant and high-temperature resistant additives; the shielding layer 3 is a copper wire braided shielding layer; the inner sheath layer 4 is made of polyurethane material; the fireproof layer 5 includes a ceramic silicone rubber layer 501 and a mica tape wrapping layer 502 arranged in sequence; the outer sheath layer 6 is made of low-smoke halogen-free flame-retardant polyolefin material.

[0023] Specifically, the outer sheath layer 6 is made of a low-smoke, halogen-free, flame-retardant polyolefin material, balancing safety, environmental protection, and mechanical protection. Regarding flame retardancy, when the outer sheath layer 6 comes into contact with flames, the flame retardant in the material acts synergistically through multiple flame-retardant mechanisms, including gas-phase and condensed-phase flame retardancy, to inhibit the material's thermal decomposition and combustion reactions, slowing the spread of flames and shortening the duration of combustion, thereby reducing the risk of fire spread. Because the material does not contain halogen elements, it does not produce toxic and harmful gases such as hydrogen chloride during combustion, avoiding the "secondary disaster" caused by traditional halogen-containing cable combustion, greatly ensuring the safety of personnel at the fire scene and the recoverability of equipment. At the same time, the low-smoke characteristic significantly reduces smoke concentration at the fire scene, maintaining good visibility and facilitating evacuation and firefighting operations. Furthermore, the outer sheath layer 6 exhibits excellent wear and tear resistance, capable of withstanding mechanical damage such as scratches from sharp objects, impacts from stones, and long-term friction. In complex external environments such as outdoor overhead installation and underground pipelines, it provides reliable physical protection for the cable's internal structures, extending the cable's service life and ensuring stable operation throughout its lifecycle.

[0024] Reference Figure 1 and Figure 3 The diameters of the multiple strands of fine copper wires inside the conductor 1 are optimized, and the twisting pitch and tension are precisely controlled to enhance the flexibility of the conductor 1.

[0025] Specifically, conductor 1 adopts a twisted structure of multiple fine copper wires. Compared with traditional single-strand conductors, this design fundamentally solves the problem of easy breakage of cables when bent. When the cable is bent and deformed, the multiple fine copper wires can slide and shift with each other. Through this dynamic displacement adjustment, the bending stress is dispersed, so that the local stress borne by each fine copper wire is greatly reduced, thereby greatly improving the flexibility of conductor 1, making it adaptable to high-flexibility demand scenarios such as robot joint movement and frequent bending inside automated equipment. The surface of each fine copper wire is tinned, which not only isolates oxygen from the contact with the copper wire, effectively suppressing the problem of decreased conductivity caused by oxidation of the copper wire during long-term use, but also can use the good wettability of tin in the electrical connection link of the cable to significantly reduce the difficulty of welding, ensure low contact resistance at the joint, and maintain the stability and efficiency of power transmission. In addition, by optimizing the diameter of the thin copper wire, the single wire is made easier to deform while ensuring sufficient current-carrying capacity. Combined with the precisely controlled twist pitch and tension, the flexibility and conductivity of conductor 1 are further improved, forming a systematic optimization from material surface treatment to overall structural design.

[0026] Reference Figure 1 and Figure 3 The thickness of the insulating layer 2 is reasonably designed according to the rated voltage and use environment of the cable.

[0027] Specifically, the insulating layer 2 is constructed from silicone rubber, enhanced with nano-magnesium hydroxide flame retardant and high-temperature additives, achieving enhanced insulation, flame retardancy, and high-temperature resistance. Thanks to its excellent elasticity and flexibility, the silicone rubber material adheres tightly to the conductor 1, maintaining a complete insulation envelope even during cable bending and deformation, effectively preventing current leakage and ensuring electrical safety. The addition of nano-magnesium hydroxide flame retardant gives the insulation layer 2 active fire-proof ability. When the cable is attacked by flames, the nano-magnesium hydroxide decomposes rapidly at high temperature. The decomposition process absorbs a large amount of heat, just like installing a "cooling device" on the cable surface, significantly reducing the cable surface temperature and inhibiting the spread of flames. At the same time, the released water vapor forms a "gas barrier" around the cable, diluting the oxygen concentration and destroying the combustion-supporting conditions among the three elements of combustion, thereby achieving high-efficiency flame retardancy. The high-temperature resistant additive changes the cross-linking structure and thermal stability of the silicone rubber molecular chain, thereby enhancing the interaction between molecular chains in a high-temperature environment, so that the insulation layer 2 can maintain good physical and mechanical properties and insulation properties even in a high-temperature environment above 200°C. In addition, the thickness of the insulation layer 2 is precisely designed according to the rated voltage and use environment of the cable, such as appropriately thickening it in a high-voltage environment and adopting a special thickness gradient design in a high-temperature and high-humidity environment, further ensuring the insulation strength and reliability to meet the application requirements of different complex working conditions.

[0028] Reference Figure 1 and Figure 3 The copper wire braiding density of the copper wire braided shielding layer 3 has been precisely calculated to effectively shield external electromagnetic interference without affecting the flexibility of the cable. The braiding angle of the copper wire braided shielding layer 3 is 45-60 degrees to achieve the best electromagnetic shielding effect.

[0029] Specifically, shielding layer 3 utilizes a braided copper wire structure, achieving efficient electromagnetic shielding based on the principle of electromagnetic induction. When an external electromagnetic interference signal is present, the changing electromagnetic field induces a current in the braided copper wire shielding layer 3. According to Lenz's law, the direction of the electromagnetic field generated by this induced current is opposite to that of the external interference signal. The two superimpose on each other, effectively canceling out external electromagnetic interference and ensuring the accuracy and stability of the electrical or data signals transmitted within the cable. This is crucial for medical equipment, communication base stations, and other locations with stringent electromagnetic environment requirements. By accurately calculating the copper wire braid density, while ensuring that the shielding effectiveness meets the requirements of standards such as GB / T12706, the braiding density is reasonably controlled to avoid cable stiffening due to excessive braiding. The braiding angle is controlled within the optimized range of 45-60 degrees, allowing the copper wire to form optimal electromagnetic reflection and absorption paths within the shielding layer. This not only achieves efficient shielding against electromagnetic interference of different frequencies, but also ensures that the shielding layer 3 has good flexibility, matching the overall high-flexibility design of the cable, and maintaining stable electromagnetic shielding performance even during frequent cable bending.

[0030] Reference Figure 1 and Figure 3 The thickness of the inner sheath layer 4 is moderate, which can provide sufficient protection without affecting the overall flexibility of the cable. Plasticizer is added to the polyurethane inner sheath layer 4 to further improve the flexibility of the inner sheath layer.

[0031] Specifically, the inner sheath layer 4 is made of polyurethane material with a plasticizer, providing a comprehensive protection system for the cable's internal structure. Polyurethane inherently possesses excellent wear resistance, flexibility, and chemical resistance, effectively protecting the conductor 1, insulation layer 2, and shielding layer 3 from damage caused by friction, stretching, and chemical corrosion during installation and use. The addition of the plasticizer acts as a "lubricant" for the polyurethane molecular chains, lowering the glass transition temperature of the polyurethane material and weakening the interactions between the molecular chains, making them more prone to relative motion. This significantly enhances the flexibility of the inner sheath layer 4, making it less susceptible to hardening and brittleness at low temperatures and allowing it to deform smoothly through complex curved paths. The moderate thickness of the inner sheath layer 4, verified by mechanical simulations and actual testing, ensures that it can withstand certain external pressures and impacts while avoiding excessive thickness that would increase the cable's rigidity, thus ensuring the overall flexibility of the cable. For example, in the internal wiring of industrial robots, the inner sheath layer 4 protects the internal structure from mechanical damage while also allowing it to flex flexibly with the complex movements of the robot's joints, ensuring the long-term and stable operation of the cable.

[0032] Reference Figure 3 The ceramic silicone rubber layer 501 has good flexibility and elasticity at room temperature, and is rapidly ceramicized to form a hard ceramic body when exposed to high temperature flame.

[0033] Specifically, the fireproof layer 5 consists of a ceramic silicone rubber layer 501 and a mica tape wrapping layer 502, creating a dual protection mechanism of "active fire protection + passive thermal insulation." The ceramic silicone rubber layer 501 maintains excellent flexibility and elasticity at room temperature, allowing it to bend freely with the cable, without affecting its installation and use. When exposed to high-temperature flames, the special inorganic fillers and polymer matrix in the ceramic silicone rubber layer 501 undergo complex solid-solid and solid-gas phase reactions, ceramicizing in an extremely short period of time, typically less than 10 seconds, transforming from a soft rubbery state into a hard, dense ceramic. Its high-temperature resistance can reach over 1000°C, forming a solid "fireproof armor" on the cable surface, effectively blocking the transmission of flames, heat, and oxygen into the cable interior, protecting the conductor 1 and insulation layer 2 from damage by high temperatures. The mica tape wrapping layer 502, with its excellent high-temperature resistance (mica melting point of 1375-1450°C) and excellent insulation properties, maintains stable physical and chemical properties in high-temperature environments. This not only further blocks heat conduction but also provides structural support for the ceramic silicone rubber layer 501, preventing it from falling off or cracking due to thermal stress at high temperatures. The two work together to significantly enhance the cable's fire resistance and continuous operating capability under extreme conditions such as fires, ensuring that critical lines can maintain normal operation for a certain period of time during a fire, buying valuable time for personnel evacuation and fire rescue.

[0034] The implementation principle of a high-flexibility, high-temperature resistant and fire-resistant cable in the embodiment of the present application is as follows: the high-flexibility, high-temperature resistant and fire-resistant cable achieves an organic unity of high flexibility, high-temperature resistance, fire resistance, electromagnetic shielding and environmental protection performance through the coordinated design of each layer structure and material. The innermost conductor 1 is made of multiple strands of fine copper wire twisted and tinned. The sliding between the fine copper wires can disperse the bending stress. The tinned layer prevents oxidation and improves the welding effect. The optimized diameter, twisting pitch and tension further enhance the flexibility and conductive stability, ensuring that the cable can still reliably transmit electricity when frequently bent. The insulating layer 2 is made of silicone rubber material with nano-magnesium hydroxide flame retardant and high-temperature resistant additives added. The conductor 1 is tightly wrapped with the flexibility of silicone rubber to prevent leakage. The flame retardant decomposes and absorbs heat and releases water vapor to prevent flame retardancy when exposed to fire. The high-temperature resistant additive strengthens the molecular chain structure. Combined with the thickness designed according to voltage and environment, insulation, flame retardancy and high-temperature resistance are achieved. The shielding layer 3 is a copper wire braided structure. According to the principle of electromagnetic induction, the induced current generates a reverse electromagnetic field to offset external interference. The accurately calculated braiding density and 45-60 The braiding angle of the cable is 100 degrees, which ensures the flexibility of the cable while meeting the electromagnetic shielding standards. It is suitable for electromagnetic sensitive scenarios. The inner sheath layer 4 is made of polyurethane material with added plasticizer. It protects the internal structure with its own wear resistance and corrosion resistance. The plasticizer reduces the glass transition temperature of the material and improves flexibility. The moderate thickness has been mechanically verified to ensure the protection capability without affecting the overall flexibility of the cable. The fireproof layer 5 is composed of a ceramic silicone rubber layer 501 and a mica tape wrapping layer 502. The ceramic silicone rubber layer 501 quickly ceramicizes when exposed to fire to form a heat insulation barrier. The mica tape wrapping layer 502 is made of a ceramic silicone rubber layer 501 and a mica tape wrapping layer 502. The ceramic silicone rubber layer 501 quickly ceramicizes when exposed to fire to form a heat insulation barrier. Layer 502 provides support and additional insulation with its high melting point and stable properties. The two work together to improve the cable's ability to continue working in a fire. The outermost sheath layer 6 is made of low-smoke halogen-free flame-retardant polyolefin material. The flame retardant inhibits combustion through multiple mechanisms. The halogen-free property avoids the production of toxic gases. The low-smoke design ensures visibility at the fire scene. The good wear resistance and tear resistance resist external mechanical damage, protect the internal structure and extend the cable life. The various layers of structure cooperate with each other, allowing the cable to operate stably under complex working conditions such as robot movement, high-temperature industrial environment, and fire.

[0035] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense, and may refer to mechanical or electrical connections, internal communication between two components, or direct connection. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute positions of the objects being described change, the relative positional relationships may also change.

[0036] Secondly: The drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention. Other structures may refer to conventional designs. The same embodiment and different embodiments of the present invention may be combined with each other without conflict.

[0037] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0038] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A highly flexible, high-temperature-resistant and fire-resistant cable, comprising a conductor (1), an insulating layer (2), a shielding layer (3), an inner sheath layer (4), a fireproof layer (5) and an outer sheath layer (6) arranged in sequence from the inside to the outside, characterized in that: The conductor (1) is made of a plurality of strands of fine copper wires twisted together, and each of the fine copper wires is plated with a layer of tin. The insulating layer (2) is made of a silicone rubber material, and a nano-magnesium hydroxide flame retardant and a high-temperature resistant additive are added to the silicone rubber material. The shielding layer (3) is a copper wire braided shielding layer. The inner sheath layer (4) is made of a polyurethane material. The fireproof layer (5) includes a ceramic silicone rubber layer (501) and a mica tape wrapping layer (502) arranged in sequence. The outer sheath layer (6) is made of a low-smoke, halogen-free, flame-retardant polyolefin material.

2. A highly flexible, high temperature resistant and fireproof cable according to claim 1, characterized in that: The diameters of the multiple strands of fine copper wires inside the conductor (1) are optimized, and the twisting pitch and tension are precisely controlled to enhance the flexibility of the conductor (1).

3. The highly flexible, high-temperature-resistant and fire-resistant cable according to claim 1, characterized in that: The thickness of the insulating layer (2) is reasonably designed according to the rated voltage and use environment of the cable.

4. The highly flexible, high-temperature-resistant and fire-resistant cable according to claim 1, characterized in that: The copper wire braiding density of the copper wire braided shielding layer (3) is precisely calculated to effectively shield external electromagnetic interference without affecting the flexibility of the cable.

5. The highly flexible, high-temperature-resistant and fire-resistant cable according to claim 1, characterized in that: The inner sheath layer (4) has a moderate thickness, which can provide sufficient protection without affecting the overall flexibility of the cable. A plasticizer is added to the polyurethane inner sheath layer (4) to further improve the flexibility of the inner sheath layer.

6. The highly flexible, high-temperature-resistant and fire-resistant cable according to claim 1, characterized in that: The ceramicized silicone rubber layer (501) has good flexibility and elasticity at room temperature, and is rapidly ceramicized to form a hard ceramic body when exposed to high-temperature flames.

7. The highly flexible, high-temperature-resistant and fire-resistant cable according to claim 1, characterized in that: The braiding angle of the copper wire braided shielding layer (3) is 45-60 degrees to achieve the best electromagnetic shielding effect.

8. The highly flexible, high-temperature-resistant and fire-resistant cable according to claim 1, characterized in that: The outer sheath layer (6) has good wear resistance and tear resistance.

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