Bending-resistant radio frequency coaxial cable

Abstract

The utility model discloses a bending-resistant radio frequency coaxial cable, which comprises an inner conductor, an insulating layer, a shielding layer and a sheath layer which are sequentially arranged from inside to outside, the inner conductor is formed by concentrically twisting a plurality of strands of silver-plated copper wire monofilaments; the insulating layer comprises an inner insulating layer and a polytetrafluoroethylene film outer insulating layer; the inner insulating layer is wrapped outside the inner conductor and is formed by sintering a polytetrafluoroethylene tape; the polytetrafluoroethylene film outer insulating layer is wrapped outside the inner insulating layer; the shielding layer comprises an inner shielding layer, a middle layer and an outer shielding layer, and the inner shielding layer is a silver-plated copper strip wrapping layer and wraps the insulating layer; the middle layer is a polyimide aluminum foil composite belt wrapping the inner shielding layer; the outer shielding layer is a silver-plated aramid yarn woven layer and is woven outside the middle layer; the sheath layer is a polytetrafluoroethylene sheath layer. The cable provided by the utility model has the characteristics of high-frequency bending resistance and good environment resistance, and also has excellent electrical transmission performance.

Description

Technical Field

[0001] The utility model relates to the technical field of communication cables, and specifically, to a bend-resistant radio frequency coaxial cable. Background Art

[0002] Wires and cables are the "neural networks" that realize the transmission of electrical energy and the interaction of information flow among various systems of the whole aircraft and connect the airborne electronic and electrical systems, and are an important guarantee for the reliable operation of the systems. For the cables used in the aircraft wings, the retraction and extension of the wings will cause the cables to twist, bend and vibrate frequently, and the internal structure is prone to fatigue fracture. Therefore, it is necessary to ensure the flexibility of the cables, and when they are bent frequently, the change of performance indicators is within the error range. Traditional radio frequency coaxial cables mainly consist of a conductor, an insulating layer, a metal shielding layer and a sheath layer, etc. Traditional radio frequency coaxial cables mostly use silver-plated copper as the materials for the inner conductor and the outer conductor, the insulating layer mostly uses polytetrafluoroethylene (PTFE), and the sheath layer uses tetrafluoroethylene copolymer and fluorinated ethylene propylene copolymer. Among them, the inner conductor uses copper wire, which has advantages such as good electrical conductivity, but is not flexible. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a bend-resistant radio frequency coaxial cable, which is used to solve the problem that the radio frequency coaxial cable in the prior art is not flexible and cannot meet the requirements of frequent bending scenarios.

[0004] The utility model solves the above problems through the following technical solutions:

[0005] A bend-resistant radio frequency coaxial cable includes an inner conductor, an insulating layer, a shielding layer and a sheath layer which are arranged in sequence from inside to outside, and the inner conductor is composed of single strands of multi-strand silver-plated copper wires twisted together.

[0006] In the utility model, the inner conductor is composed of single strands of multi-strand silver-plated copper wires twisted together. The silver-plated copper stranded wire combines the advantages of silver-plated wire and silver-plated copper, has better flexibility than a single silver-plated copper wire, and has advantages such as small impedance, good electrical conductivity, strong shielding performance and bend resistance, can enable the current to pass through smoothly, and ensure the efficient operation of the equipment.

[0007] Furthermore, the insulating layer includes an inner insulating layer wound around the outer side of the inner conductor and an outer insulating layer wound around the inner insulating layer. The inner insulating layer is sintered from polytetrafluoroethylene tape, and the outer insulating layer is a polytetrafluoroethylene film.

[0008] The sintered insulating layer has excellent insulation performance, and can effectively control the change of the attenuation amount to a certain extent when the cable is bent at high speed and frequently bent, so that the attenuation index is more stable. The polytetrafluoroethylene film insulating layer is wound around the sintered insulating layer. Polytetrafluoroethylene has excellent chemical stability, corrosion resistance, sealing performance, high lubricity and non-stickiness, electrical insulation performance and good anti-aging endurance.

[0009] Further, the inner insulating layer is sintered by a sintering machine at a temperature of 350°C to 360°C, and the density of the polytetrafluoroethylene tape is 1.6 g / cm 3 .

[0010] Further, the outer insulating layer is a low-density microporous polytetrafluoroethylene film, and the material density of the low-density microporous polytetrafluoroethylene film is 0.5 g / cm 3 ~0.6 g / cm 3 . It is only half of the density of the conventional polytetrafluoroethylene material. Adopting this technical measure has strong temperature stability and excellent electrical performance indicators. While ensuring the transmission performance, it can effectively reduce the product weight.

[0011] Further, the shielding layer includes an inner shielding layer wrapped around the outer insulating layer, an intermediate layer wrapped around the inner shielding layer, and an outer shielding layer braided outside the intermediate layer. The inner shielding layer is a silver-plated copper tape wrapping layer, and its advantages include high conductivity, excellent thermal conductivity, oxidation resistance, etc.; the intermediate layer is a polyimide aluminum foil composite tape, which has excellent high and low temperature resistance and good dielectric properties; the outer shielding layer is a silver-plated aramid fiber braided layer.

[0012] The triple combination shielding layer of the inner shielding layer, the intermediate layer, and the outer shielding layer improves the shielding efficiency of the cable. Compared with the shielding layer of a single-layer structure, the electrical performance of the cable has also been greatly improved. The outer shielding layer uses silver-plated aramid fibers, and the material density of the silver-plated aramid fibers is only 1.45 g / cm 3 , which is one-sixth of the weight of copper wires of the same specification; aramid fibers have excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight.

[0013] Further, the braiding density of the outer shielding layer ≥ 90%.

[0014] Further, the sheath layer is polytetrafluoroethylene and is wrapped around the outer shielding layer. The density is smaller than that of traditional sheath layers (such as tetrafluoroethylene copolymer, fluorinated ethylene propylene copolymer sheath layer, etc.), and it is softer. Using polytetrafluoroethylene wrapping as the sheath layer enhances the flexibility of the cable and improves the cable's resistance to bending.

[0015] Further, the thickness of the sheath layer is less than 0.10 mm.

[0016] Further, the thickness of the intermediate layer is less than 0.038 mm.

[0017] Further, the lapping rate of the inner shielding layer is 40% - 60%.

[0018] Further, the inner conductor is concentrically stranded by multiple silver-plated copper wire single strands.

[0019] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0020] (1) The utility model has the characteristics of good flexibility, high-frequency bending resistance and good environmental resistance, and at the same time has excellent electrical transmission performance, and is suitable for frequently bent environments.

[0021] (2) The inner conductor of the utility model has better softness than a single silver-plated copper wire, and has the advantages of small impedance, good conductivity, strong shielding performance, etc., which can enable current to pass through smoothly and ensure the efficient operation of the equipment.

[0022] (3) The sintered inner insulating layer of the utility model has excellent insulation performance, and can effectively control the change of the attenuation amount to a certain extent under the conditions of high-speed bending and frequent bending of the cable, so that the attenuation index is more stable. The outer insulating layer has excellent chemical stability, corrosion resistance, sealing performance, high lubricity and non-adhesion, electrical insulation and good anti-aging endurance.

[0023] (4) The inner shielding layer of the utility model is a silver-plated copper tape wrapping layer, which is wrapped outside the insulating layer. The advantages include high conductivity, excellent heat conduction performance, oxidation resistance, etc.

[0024] (5) The middle layer of the utility model is a polyimide aluminum foil composite tape wrapped outside the inner shielding layer, and has excellent high and low temperature resistance and good dielectric properties.

[0025] (6) The outer shielding layer of the utility model is made of silver-plated aramid woven fabric, and has excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight; the inner shielding layer, the middle layer and the outer shielding layer form a triple combined shielding layer, which improves the shielding efficiency of the cable. Compared with the shielding layer of a single-layer structure, the electrical performance of the cable is also improved to a large extent.

[0026] (7) The sheath layer of the utility model adopts a polytetrafluoroethylene sheath layer, which has a smaller density than the traditional sheath layer and is softer, enhancing the flexibility of the cable and improving the bending resistance of the cable.

[0027] (8) The insulating layer of the utility model is made of a low-density polytetrafluoroethylene microporous film, which has strong temperature stability and excellent electrical performance indexes. While ensuring the transmission performance, it can effectively reduce the product weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of the utility model;

[0029] Wherein, 1 - inner conductor; 2 - insulating layer; 3 - inner shielding layer; 4 - middle layer; 5 - outer shielding layer; 6 - sheath layer; 21 - inner insulating layer; 22 - outer insulating layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present utility model will be further described in detail below in conjunction with embodiments, but the implementation manners of the present utility model are not limited thereto.

[0031] Embodiment 1:

[0032] Combined with the attached Figure 1 As shown, a bend-resistant radio frequency coaxial cable includes an inner conductor 1, an insulating layer 2, a shielding layer, and a sheath layer 6 arranged in sequence from inside to outside. The inner conductor 1 is formed by stranding multiple silver-plated copper wire single filaments.

[0033] In the present utility model, the inner conductor 1 is formed by stranding multiple silver-plated copper wire single filaments. The silver-plated copper stranded wire combines the advantages of silver-plated wire and silver-plated copper, having high conductivity, excellent electrical conductivity, and thermal conductivity. It is formed by plating silver on oxygen-free copper to reduce the contact resistance on the metal surface and improve the welding performance. Moreover, it has better flexibility than a single silver-plated copper wire, with advantages such as small impedance, strong shielding performance, and bend resistance, allowing current to pass smoothly and ensuring the efficient operation of the equipment.

[0034] Furthermore, the inner conductor 1 is concentrically stranded by multiple silver-plated copper wires. The arrangement is as follows: one silver-plated copper wire in the center serves as the first layer, and six silver-plated copper wires in the second layer are evenly placed on the outer surface of the first layer. The remaining multiple silver-plated copper wires are placed on the outer surface of the upper layer according to the rule that each layer has six more wires than the previous layer. The silver-plated copper stranded wire has a smaller bending radius, the product is more flexible, and the bend resistance effect is more obvious.

[0035] Embodiment 2:

[0036] Based on Embodiment 1, combined with Figure 1 As shown, the insulating layer 2 includes an inner insulating layer 21 wrapped around the outer surface of the inner conductor 1 and an outer insulating layer 22 wrapped around the inner insulating layer 21. The inner insulating layer 21 is formed by wrapping polytetrafluoroethylene around the outer surface of the inner conductor 1 and then sintering at a high temperature above 350 °C. The density of the polytetrafluoroethylene tape is 1.6 g / cm 3 , which plays a certain protective role for the inner conductor 1. Polytetrafluoroethylene has excellent chemical stability, corrosion resistance, sealing performance, high lubricity and non-stickiness, electrical insulation, and good anti-aging endurance. At the same time, when the cable is bent at high speed or frequently bent, it can also reduce the attenuation change amount of the cable, making the attenuation index more stable. The outer insulating layer 22 is a polytetrafluoroethylene film wrapped around the inner insulating layer 21, which is a low-density microporous polytetrafluoroethylene film outer insulating layer made of low-density polytetrafluoroethylene microporous film, with a density of only 0.5 g / cm 3 ~0.6 g / cm 3 , only half of the density of conventional polytetrafluoroethylene materials. Adopting this technical measure has strong temperature stability and excellent electrical performance indicators, ensuring the transmission performance while effectively reducing the product weight.

[0037] Example 3:

[0038] Based on Example 2, combined with Figure 1 As shown, the shielding layer includes an inner shielding layer 3 wrapped around the outer insulating layer 22, an intermediate layer 4 wrapped around the inner shielding layer 3, and an outer shielding layer 5 braided outside the intermediate layer 4. The intermediate layer 4 is a polyimide aluminum foil composite film wrapped around the inner shielding layer 3. The function of the intermediate layer 4 can effectively prevent the cable from cracking and breaking when it is frequently bent. The inner shielding layer 3 is a silver-plated copper tape wrapping layer, and its advantages include high conductivity, excellent thermal conductivity, oxidation resistance, etc. Further, the lapping rate of the inner shielding layer 3 is 40% - 60%. The intermediate layer 4 is a polyimide aluminum foil composite tape, which has excellent high and low temperature resistance and good dielectric properties. Further, the thickness of the intermediate layer 4 is less than 0.038 mm. The outer shielding layer 5 is a silver-plated aramid fiber braided layer, and the material density of the silver-plated aramid fiber is only 1.45 g / cm 3 , which is one-sixth of the weight of copper wire of the same specification, is softer, and the braiding density ≥ 90%. Aramid fiber has excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight. The triple combination shielding layer of the inner shielding layer 3, the intermediate layer 4, and the outer shielding layer 5 has a better shielding effect than the single-layer shielding and the double-layer shielding, enhances the shielding effect of the cable, and improves the shielding efficiency. Compared with the shielding layer of the single-layer structure, the electrical performance of the cable has also been greatly improved.

[0039] Example 4:

[0040] Based on Example 2, combined with Figure 1 As shown, the sheath layer 6 is polytetrafluoroethylene, wrapped around the outer shielding layer 5. Polytetrafluoroethylene has excellent chemical stability, corrosion resistance, sealing performance, high lubricity and non-stickiness, electrical insulation, and good anti-aging endurance. Compared with the ordinary sheath layer 6, such as the polyvinyl fluoride copolymer and the fluorinated ethylene propylene copolymer sheath layer 6. It has a smaller density and is softer. Using polytetrafluoroethylene wrapping as the sheath layer 6 enhances the flexibility of the cable and improves the bending resistance of the cable.

[0041] Further, the thickness of the sheath layer 6 is less than 0.10 mm.

[0042] Although the present invention has been described here with reference to the illustrative embodiments of the present invention, the above embodiments are only the preferred embodiments of the present invention. The embodiments of the present invention are not limited by the above embodiments. It should be understood that those skilled in the art can design many other modifications and embodiments, and these modifications and embodiments will fall within the scope of the principles and spirit disclosed in this application.

Claims

1. A bending-resistant radio frequency coaxial cable, comprising an inner conductor, an insulating layer, a shielding layer and a sheath layer arranged in sequence from the inside to the outside, characterized in that: The inner conductor is formed by twisting multiple silver-plated copper wires; The insulating layer comprises an inner insulating layer wrapped around the inner conductor and an outer insulating layer wrapped around the inner insulating layer, the inner insulating layer is sintered from a polytetrafluoroethylene tape, and the outer insulating layer is a polytetrafluoroethylene film; The outer insulating layer is a low-density microporous polytetrafluoroethylene film, and the material density of the low-density microporous polytetrafluoroethylene film is 0.5g / cm 3 ~0.6g / cm 3 ; The shielding layer comprises an inner shielding layer wrapped around the outer insulating layer, an intermediate layer wrapped around the inner shielding layer, and an outer shielding layer woven outside the intermediate layer, wherein the inner shielding layer is a silver-plated copper tape wrapped layer, the intermediate layer is a polyimide aluminum foil composite tape, and the outer shielding layer is a silver-plated aramid wire braided layer; The sheath layer is made of polytetrafluoroethylene and is wrapped around the outer shielding layer. The thickness of the sheath layer is less than 0.10 mm.

2. The bending-resistant radio frequency coaxial cable according to claim 1, characterized in that: The braiding density of the outer shielding layer is ≥90%.

3. The bending-resistant radio frequency coaxial cable according to claim 1, characterized in that: The thickness of the intermediate layer is less than 0.038 mm.

4. The bending-resistant radio frequency coaxial cable according to claim 1, characterized in that: The overlapping rate of the inner shielding layer is 40% to 60%.

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