Composite shielding cable

Abstract

The invention relates to the technical field of cables, in particular to a composite shielding cable which comprises a plurality of wires used for transmitting signals. The filling layer is used for filling gaps in the cable; the composite shielding layer is used for homogenizing an electric field and isolating external electromagnetic interference; the reinforcing layer is used for improving the mechanical strength of the cable; the outer protective layer is used for enhancing the mechanical property of the cable; the composite shielding layer is of a metal and fiber multi-axial mixed braided structure; the reinforcing layer is formed by weaving ultra-high molecular weight polyethylene fibers and para-aramid fibers. According to the composite shielding cable, the composite shielding layer can reduce the weight and thickness of the cable and realize light weight, and the reinforcing layer can realize high temperature resistance and reduce the cost. Through a double-braided structure of the composite shielding layer and the reinforcing layer, a traditional shielding layer and glass fiber reinforcing structure can be replaced, on the basis of ensuring high shielding performance, the mechanical strength of the cable is effectively improved, and meanwhile, the safety of a cable production and processing environment is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and specifically to a composite shielded cable. Background Art

[0002] A shielded cable is a transmission line that uses a metal mesh braid to wrap the signal wire. The braid is generally made of red copper or tinned copper. Shielding is to ensure the transmission performance of the system in an electromagnetic interference environment, that is, the ability to resist external electromagnetic interference and the ability of the system itself to radiate electromagnetic interference outward.

[0003] Composite shielded cables are usually used in long-distance overhead scenarios or high-temperature environments. Therefore, glass fiber is currently widely used in such cables. Glass fiber has excellent heat resistance and mechanical strength, and at the same time has good insulation, which can avoid eddy current loss or electromagnetic interference, and is especially suitable for scenarios that require high shielding efficiency.

[0004] However, glass fiber is brittle and easy to break, and is not suitable for environments with frequent bending. In addition, a large amount of fiber dust is easily formed during processing and diffuses into the air, harming the working environment and affecting the health of workers. In view of this, we propose a composite shielded cable. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a composite shielded cable, which solves the problems that the current composite shielded cable needs to use glass fiber, resulting in the cable not being suitable for environments with frequent bending and the poor cable production environment.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A composite shielded cable, comprising:

[0008] Multiple conductors for transmitting signals;

[0009] A filling layer for filling the internal gap of the cable;

[0010] A composite shielding layer for equalizing the electric field and isolating external electromagnetic interference;

[0011] A strengthening layer for improving the mechanical strength of the cable;

[0012] An outer sheath for enhancing the mechanical properties of the cable;

[0013] The composite shielding layer is a multi-axial hybrid braided structure of metal and fiber;

[0014] The strengthening layer is woven from ultra-high molecular weight polyethylene fiber and para-aramid.

[0015] As a preferred technical solution, the composite shielding layer is formed by three-dimensional spiral weaving of copper wires and degradable polyester fibers.

[0016] As a preferred technical solution, the surface of the copper wire is coated with a water-based nano-aluminum oxide coating.

[0017] As a preferred technical solution, the three-dimensional spiral weaving structure is filled with foamed silica gel in the middle.

[0018] As a preferred technical solution, the wire includes a conductor, an inner shielding layer is coated outside the conductor, and an insulating layer is coated outside the inner shielding layer.

[0019] As a preferred technical solution, the inner shielding layer is made of a mixture of graphene and a semi-conductive polymer, and the insulating layer is nano-ceramic modified cross-linked polyethylene.

[0020] As a preferred technical solution, the filling material of the filling layer is a PP rope.

[0021] As a preferred technical solution, the mass ratio of ultra-high molecular weight polyethylene fiber to para-aramid in the strengthening layer is 7:3, and the weaving method is orthogonal weaving.

[0022] As a preferred technical solution, the outer protective layer is made of thermoplastic polyurethane plus a flame retardant.

[0023] As a preferred technical solution, the outer peripheral side of the strengthening layer is subjected to plasma treatment.

[0024] By means of the above technical solution, the present invention provides a composite shielded cable. It has at least the following beneficial effects:

[0025] (1) For this composite shielded cable, the composite shielding layer is a multi-axial hybrid weaving structure of metal and fiber, which can reduce the weight and thickness of the cable, achieve lightweight, and the strengthening layer is woven by ultra-high molecular weight polyethylene fiber and para-aramid, which can achieve high temperature resistance and reduce costs. Through the double weaving structure of the composite shielding layer and the strengthening layer, it can replace the traditional shielding layer and glass fiber strengthening structure, effectively improve the mechanical strength of the cable on the basis of ensuring high shielding performance, and at the same time ensure the safety of the cable production and processing environment.

[0026] (2) For this composite shielded cable, through the double shielding of the inner shielding layer and the composite shielding layer, the shielding performance of the cable can be significantly improved. Among them, doping graphene material in the inner shielding layer can improve the heat dissipation of the cable. By filling foamed silica gel in the middle of the three-dimensional spiral weaving structure, the stress can be dispersed, the bending life of the cable can be improved, and the cable can adapt to more complex use environments. Brief Description of the Drawings

[0027] The accompanying drawings described herein are used to provide a further understanding of the present invention and form a part of this application:

[0028] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention.

[0029] In the figure: 1. Conducting wire; 101. Conductor; 102. Inner shielding layer; 103. Insulating layer; 2. Filling layer; 3. Composite shielding layer; 4. Reinforcing layer; 5. Outer sheath. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] A shielded cable is a transmission line that uses a metal mesh braid to wrap the signal wire. The braid is generally red copper or tinned copper. Shielding is to ensure the transmission performance of the system in an electromagnetic interference environment, that is, the ability to resist external electromagnetic interference and the ability of the system itself to radiate electromagnetic interference outward.

[0032] Composite shielded cables are usually used in long-distance overhead scenarios or high-temperature environments. Therefore, glass fibers are currently widely used in such cables. Glass fibers have excellent heat resistance and mechanical strength, and at the same time have good insulation properties, which can avoid eddy current losses or electromagnetic interference, and are especially suitable for scenarios that require high shielding efficiency.

[0033] However, glass fibers are brittle and easy to break, and are not suitable for environments with frequent bending. In addition, a large amount of fiber dust is easily formed during processing and diffuses into the air, endangering the working environment and affecting the health of the staff.

[0034] Please refer to Figure 1 , a technical solution provided by the present invention:

[0035] A composite shielded cable includes a conductor 1 for transmitting current or electromagnetic signals. The conductor 1 is formed by stranding a plurality of conductors 101, and the conductors 101 are made of copper or aluminum. Each conductor 101 is coated with an inner shielding layer 102 which closely adheres to the conductor 101. The inner shielding layer 102 can uniform the electric field on the surface of the conductor 101, prevent partial discharge, suppress electromagnetic interference, and protect the integrity of the signal. The inner shielding layer 102 is made of a mixture of a semi-conductive polymer and 1.5% graphene nanosheets, which can improve the thermal conductivity and enhance the heat dissipation while uniforming the electric field. The inner shielding layer 102 is coated with an insulating layer 103 which is used to isolate the conductor 101 from the external electric field and prevent current leakage or short circuit. The insulating layer 103 is cross-linked polyethylene which has the advantages of high temperature resistance and high voltage resistance, and at the same time ensures the mechanical strength of the conductor 1.

[0036] In this embodiment, the conductor 1 is coated with a filling layer 2 for filling the internal gap of the cable, supporting the outer structure of the conductor 1, and ensuring the roundness and mechanical stability of the cable structure. The filling material of the filling layer 2 is a PP rope.

[0037] In this embodiment, the filling layer 2 is coated with a composite shielding layer 3 for further homogenizing the electric field, isolating external electromagnetic interference, and preventing information leakage. The composite shielding layer 3 is a multi-axial hybrid woven structure of metal and fiber.

[0038] Specifically, the composite shielding layer 3 is formed by three-dimensional spiral weaving of copper wires and degradable polyester fibers. The three-dimensional spiral structure allows a larger bending radius, improves flexibility, and can evenly distribute external forces to the surfaces of the copper wires and fibers, reducing local stress concentration and extending the fatigue life. Moreover, the continuous coverage rate of the copper wires is higher, and the shielding effectiveness is better. The middle of the three-dimensional spiral woven structure is filled with foamed silica gel, which can buffer stress and avoid the problem of copper wire fatigue fracture after the cable is frequently bent, thus improving the bending life of the cable. The diameter of the copper wire is 0.1 mm, and its surface is coated with a water-based nano-aluminum oxide coating with a coating thickness of 3 μm - 5 μm, which can insulate the copper wire, prevent the copper wire from oxidizing in a high-humidity environment, and avoid the problems of excessive thickening and weight gain caused by traditional extrusion processes. Using a water-based coating can reduce the emission of volatile organic compounds. Using degradable polyester fibers can improve environmental protection.

[0039] In this embodiment, a reinforcing layer 4 is wrapped around the composite shielding layer 3, which is used to improve the mechanical strength of the cable, protect the conductor 1 from mechanical damage, and further improve the electromagnetic shielding ability of the cable. Thus, without using glass fiber, the shielding and tensile properties of the cable can be ensured. The reinforcing layer 4 is formed by orthogonal weaving of ultra-high molecular weight polyethylene fibers and para-aramid. The mass ratio of ultra-high molecular weight polyethylene fibers to para-aramid is 7:3. The strength of ultra-high molecular weight polyethylene fibers is twice that of glass fiber, and its density is only one-third of that of glass fiber. The tensile strength of aramid fiber is 30% - 50% higher than that of glass fiber, and it has better flexibility, is suitable for frequent bending scenarios, and has a lower density (1.44 g / cm 3 vs 2.5 g / cm for glass fiber 3 ). It can reduce the weight by about 40%, ensuring the tensile strength, high temperature resistance, insulation and shielding efficiency of the cable. After the ultra-high molecular weight polyethylene fibers and para-aramid are woven, the overall tensile strength is significantly improved, and the total weight is reduced, achieving lightweight. Using orthogonal weaving, the difficulty is lower, the weaving efficiency can be improved, and the cost can be reduced.

[0040] Furthermore, both the reinforcing layer 4 and the composite shielding layer 3 adopt a woven structure, which can avoid the accumulation of weight and thickness of the traditional layered structure.

[0041] In this embodiment, an outer sheath 5 is wrapped around the reinforcing layer 4, which is used to enhance the mechanical properties of the cable, resist external pressure or tension, and protect the inner structure from damage, so that the cable can adapt to more complex environments. The outer sheath 5 is made of 50% thermoplastic polyurethane plus a halogen-free flame retardant. Thermoplastic polyurethane has excellent comprehensive properties such as high strength, high toughness, wear resistance, and oil resistance, and has good processing performance. Adding a flame retardant can improve the fire resistance of the cable and enhance safety.

[0042] In addition, plasma treatment is performed on the outer peripheral side of the reinforcing layer 4 to improve the bonding force of the woven structure and prevent the outer sheath 5 from detaching from the reinforcing layer 4.

[0043] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0044] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite shielded cable, characterized in that: include: A plurality of wires (1) for transmitting signals; A filling layer (2), used to fill the internal gap of the cable; A composite shielding layer (3) for homogenizing the electric field and isolating external electromagnetic interference; A reinforcement layer (4), used to improve the mechanical strength of the cable; An outer sheath (5) for enhancing the mechanical properties of the cable; The composite shielding layer (3) is a metal and fiber multi-axial mixed braided structure; The reinforcement layer (4) is woven from ultra-high molecular weight polyethylene fibers and para-aramid fibers.

2. The composite shielded cable according to claim 1, characterized in that: The composite shielding layer (3) is formed by three-dimensional spiral weaving of copper wires and degradable polyester fibers.

3. The composite shielded cable according to claim 1, characterized in that: The surface of the copper wire is coated with water-based nano-aluminum oxide coating.

4. The composite shielded cable according to claim 2, characterized in that: The middle of the three-dimensional spiral braided structure is filled with foamed silica gel.

5. The composite shielded cable according to claim 1, characterized in that: The wire (1) comprises a conductor (101), the conductor (101) is coated with an inner shielding layer (102), and the inner shielding layer (102) is coated with an insulating layer (103).

6. The composite shielded cable according to claim 1, characterized in that: The inner shielding layer (102) is formed by mixing graphene and a semi-conductive polymer, and the insulating layer (103) is nano-ceramic modified cross-linked polyethylene.

7. The composite shielded cable according to claim 1, characterized in that: The filling material of the filling layer (2) is PP rope.

8. The composite shielded cable according to claim 1, characterized in that: The mass ratio of ultra-high molecular weight polyethylene fibers to para-aramid fibers in the reinforcement layer (4) is 7:3, and the weaving method is orthogonal weaving.

9. The composite shielded cable according to claim 1, characterized in that: The outer protective layer (5) is made of thermoplastic polyurethane and flame retardant.

10. The composite shielded cable according to claim 1, characterized in that: The outer peripheral side of the reinforcement layer (4) is subjected to plasma treatment.

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