Photoelectric composite cable suitable for unmanned aerial vehicle platform

Abstract

The invention relates to a photoelectric composite cable suitable for an unmanned aerial vehicle platform, which comprises a wrapping layer formed by wrapping a covering film, an accommodating space is formed in the wrapping layer, a two-core electric unit and a one-core single-mode optical fiber are respectively placed in the accommodating space, and a plurality of aramid fibers are distributed in the accommodating space and are filled to form a cable; an insulating layer is distributed on the electric unit, an outer wrapping layer is distributed on the single-mode optical fiber, and the insulating layer, the outer wrapping layer and the covering film are all made of high-temperature-resistant fluoroplastic formed by ethylene-tetrafluoroethylene copolymer; the thickness of the covering film is 0.05 mm, and the total thickness after wrapping is 0.10 mm + / -0.02 mm; the outer diameter of the photoelectric composite cable is 2.2 mm + / -0.1 mm, and the total weight per meter is smaller than or equal to 12 g. Therefore, the whole photoelectric composite cable has better high temperature resistance, can meet high tensile strength under the condition of light weight, can realize low-loss signal transmission, and has better heat dissipation effect.

Description

Technical Field

[0001] The present invention relates to a cable for an unmanned aerial vehicle, and particularly to an optical and electrical composite cable suitable for an unmanned aerial vehicle platform. Background Art

[0002] For existing unmanned aerial vehicle platforms, in order to meet the need for long-term stay in the air, corresponding cables are often connected. However, in the current prior art, the temperature resistance performance of the insulating materials of conventional unmanned aerial vehicle cables is insufficient. For example, in the prior art CN201130549Y, which discloses a fluoroplastic-insulated high-temperature resistant and anti-corrosion cable with a cable structure of a perfluoroethylene-propylene (FEP) insulation layer, its long-term allowable operating temperature can reach above 200 °C, but this patent does not address the lightweight, heat dissipation, and optical and electrical composite transmission requirements in the application scenario of an unmanned aerial vehicle platform. Conventional materials such as polyvinyl chloride (PVC) or cross-linked polyethylene (XLPE) have a temperature resistance range usually of -10 °C to 90 °C, and are prone to aging under high-power operating conditions of unmanned aerial vehicles, resulting in a risk of spontaneous combustion of the cable.

[0003] At the same time, the temperature resistance performance of the currently used optical fiber coating materials is limited. For example, in the prior art CN222093872U, which provides an optical fiber coating die, an optical fiber coating platform, and a high-temperature resistant optical fiber. It discloses the use of a fluoroplastic coating to improve the temperature resistance of the optical fiber, but its coating process is not optimized for the mechanical strength and high-temperature attenuation problems under the dynamic load of an unmanned aerial vehicle. Conventional optical fiber coating materials (such as acrylate) are prone to thermal deformation in an environment above 75 °C, resulting in an excessive attenuation of the optical signal.

[0004] Moreover, the existing cables are not ideal in terms of lightweight, tensile strength, etc. Their wrapping layer still uses a traditional extrusion sheath, resulting in a relatively large outer diameter of the cable (≥5.8 mm) and insufficient heat dissipation performance, and cannot meet the requirement of the cable weight ≤12 g / m for the long-term stay in the air of an unmanned aerial vehicle.

[0005] In view of the above-mentioned defects, the present inventor has actively carried out research and innovation in order to create an optical and electrical composite cable suitable for an unmanned aerial vehicle platform, making it more valuable in industrial applications. Summary of the Invention

[0006] To solve the above technical problems, the object of the present invention is to provide an optical and electrical composite cable suitable for an unmanned aerial vehicle platform.

[0007] An optoelectronic composite cable applicable to a drone platform according to the present invention includes a wrapping layer formed by covering and winding a film, wherein: a receiving space is formed inside the wrapping layer, and a two-core electrical unit and a single-core single-mode optical fiber are respectively placed inside the receiving space, and a plurality of aramid fibers are also distributed inside the receiving space to form a cable; an insulating layer is distributed on the electrical unit, and an outer wrapping layer is distributed on the single-mode optical fiber, and the insulating layer, the outer wrapping layer, and the covering film are all made of high-temperature-resistant fluoroplastics formed by ethylene-tetrafluoroethylene copolymer; the thickness of the covering film is 0.05 mm, and the total thickness after winding is 0.10 mm ± 0.02 mm; the outer diameter of the optoelectronic composite cable is 2.2 mm ± 0.1 mm, and the total weight per meter ≤ 12 g.

[0008] Further, for the above-mentioned optoelectronic composite cable applicable to a drone platform, the conductor (7) of the electrical unit (1) is composed of 19 tinned copper wires with a diameter of 0.15 mm stranded together, the stranding pitch ratio ≤ 12 times, and the resistance of the conductor (7) ≤ 50 Ω / km.

[0009] Even further, for the above-mentioned optoelectronic composite cable applicable to a drone platform, the single-mode optical fiber is a G657A2 type bend-insensitive optical fiber, and the total outer diameter including the outer wrapping layer is 0.5 mm, and the attenuation value at wavelengths of 1310 nm and 1550 nm ≤ 0.3 dB / km.

[0010] Even further, for the above-mentioned optoelectronic composite cable applicable to a drone platform, 6 aramid fibers are used, which are respectively distributed symmetrically in a circular pattern inside the receiving space; the aramid fibers are 3340 type aramid fibers, with a density of 1.44 g / cm³, a maximum breaking force ≥ 4000 N, and a long-term service temperature ≥ 180 °C, and can form a cooperative temperature-resistant system with the wrapping layer.

[0011] Even further, for the above-mentioned optoelectronic composite cable applicable to a drone platform, the covering film is provided with a plurality of micropores with pore diameters of 5 - 20 μm; the covering film is wound through a pre-calendering forming process to form a wrapping layer.

[0012] Even further, for the above-mentioned optoelectronic composite cable applicable to a drone platform, the micropores are opened through a laser etching process, and the density of the micropores is 50 - 200 pieces / cm².

[0013] Even further, for the above-mentioned optoelectronic composite cable applicable to a drone platform, the thickness of the insulating layer is 0.1 mm ± 0.02 mm, the continuous working voltage is 400 V, and the dielectric strength ≥ 1000 MΩ·km.

[0014] Furthermore, in the above-mentioned fiber optic composite cable applicable to a drone platform, a buffer layer made of silicone rubber is distributed between the wrapping layer and the aramid fiber filling layer. The thickness of the buffer layer is 0.2 mm, and the Shore hardness is 40A ± 5A.

[0015] By means of the above solution, the present invention has at least the following advantages: 1. The entire fiber optic composite cable has excellent high-temperature resistance. The insulating layer of the electrical unit, the fiber optic coating, and the wrapping layer all adopt high-temperature-resistant fluoroplastics, with a temperature resistance range covering -196°C to 200°C, significantly superior to the -40°C to 90°C temperature resistance limit of conventional materials, solving the risk of cable spontaneous combustion during high-power operation of the drone and the problem of high-temperature attenuation of optical fibers. The aramid fiber filling layer and the high-temperature-resistant fluoroplastic form a synergistic temperature-resistant system, and the long-term working temperature can reach 180°C, avoiding deterioration of material properties in high-temperature environments.

[0016] 2. It can meet the high tensile strength under lightweight conditions. Six aramid fibers are used for filling, and the total weight of the cable ≤ 12 g / m, reducing the weight by 83% compared with steel core optical cables. The axial tensile strength ≥ 500 N, and the maximum breaking force ≥ 4000 N, meeting the flight conditions of the drone with a dynamic load ≥ 10 g. At the same time, the electrical unit adopts a design of several strands of tinned copper stranded wires to improve the flexibility and heat dissipation of the conductor.

[0017] 3. It can achieve low-loss signal transmission. The single-mode optical fiber is combined with an outer coating made of high-temperature-resistant fluoroplastic, with an attenuation ≤ 0.3 dB / km, a 25% reduction compared with conventional optical fibers, ensuring the lossless transmission of high-definition images and real-time control signals. The outer diameter of the fiber optic coating is only 0.5 mm, with a small fiber diameter and strong bending resistance, adapting to the wiring in the narrow space of the drone and the high-frequency vibration environment.

[0018] 4. It has a better heat dissipation effect. The heat dissipation efficiency of the wrapping layer is increased by 30% through laser etching of micropores, solving the problem of cable core temperature rise under high-current conditions.

[0019] 5. It can achieve the integration of chemical protection and mechanical buffering. The high-temperature-resistant fluoroplastic is resistant to acid and alkali corrosion, and the aramid fiber resists the erosion of organic solvents, and can adapt to complex environments without additional protective layers.

[0020] 6. The overall structure is simple, facilitating processing and manufacturing, and the implementation cost is low.

[0021] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it in accordance with the content of the specification, the following takes the preferred embodiments of the present invention and combines with the attached drawings to describe in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the fiber optic composite cable applicable to a drone platform.

[0023] Figure 2 It is a schematic cross-sectional structure diagram of an optoelectronic composite cable applicable to a drone platform.

[0024] (It should be noted that after the aramid fiber is filled into the cable, it will fill the gaps in the accommodation space, and the monomers of single aramid fibers are no longer marked in the attached drawings.) The meanings of the reference numerals in the drawings are as follows.

[0025] Specific Embodiments The following will further describe in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0026] As Figures 1 to 2 An optoelectronic composite cable applicable to a drone platform, including a wrapping layer formed by wrapping a covering film 4. The difference is that: an accommodation space is formed inside the wrapping layer, and a two-core electrical unit 1 and a single-core single-mode optical fiber 2 are respectively placed inside the accommodation space. Thus, it can conveniently meet the power supply and data transmission requirements of the drone. At the same time, in order to protect the electrical unit 1 and the single-mode optical fiber 2, several aramid fibers 3 are distributed and filled into the cable inside the accommodation space. In order to meet the use safety and achieve necessary insulation and high-temperature protection, the electrical unit 1 is distributed with an insulating layer 5, and the single-mode optical fiber 2 is distributed with an outer wrapping layer 6. During manufacturing, the insulating layer 5, the outer wrapping layer 6, and the covering film 4 are all made of a high-temperature-resistant fluoroplastic composed of ethylene-tetrafluoroethylene copolymer. In order to have a suitable overall outer diameter and achieve a proper interval from the external environment, the thickness of the covering film 4 used is 0.05 mm, and the total thickness after wrapping is 0.10 mm ± 0.02 mm. In this way, after installation, the outer diameter of the optoelectronic composite cable is 2.2 mm ± 0.1 mm. Furthermore, since aramid fibers 3 are used as the internal filler, the total weight per meter ≤ 12 g, which meets the requirement for the drone to stay in the air for a long time.

[0027] Combined with a preferred embodiment of the present invention, the conductor 7 of the electrical unit 1 is composed of several strands of tinned copper stranded wires. Specifically, the stranded wire structure is composed of 19 tinned copper wires with a diameter of 0.15 mm, the stranding pitch ratio ≤ 12 times, the resistance of the conductor 7 ≤ 50 Ω / km, and the working current can reach more than 5 A. The reason is that the copper conductor 7 is a conductor material with excellent electrical and mechanical properties. After being combined by the stranded wire structure, it can also improve the flexibility and heat dissipation of the conductor 7. At the same time, tin plating can well improve the oxidation resistance, welding processability, and corrosion resistance of the copper wire. And relying on the adoption of the high-temperature-resistant fluoroplastic, the cable can work efficiently for a long time at 150 °C, solving the problems of conventional drone composite cables such as self-heating and aging, intolerance to high temperatures, and inability to be used for a long time.

[0028] Furthermore, the single-mode optical fiber 2 used is a bend-insensitive optical fiber of type G657A2, and the total outer diameter including the outer cladding 6 is 0.5 mm. In this way, the overall fiber diameter of the single-mode optical fiber 2 is small, and the attenuation of light propagating along a single mode is lower, which can meet the needs of long-distance transmission. At the same time, it has strong anti-interference ability to ensure the stability and reliability of signal transmission. The optical fiber coating uses high-temperature fluoroplastics, which endows the optical fiber with excellent chemical resistance and high-temperature resistance, and at the same time has higher mechanical strength and bend resistance. It meets the use requirements of an attenuation value ≤ 0.3 dB / km at wavelengths of 1310 nm and 1550 nm or in a high-temperature working environment, and can achieve lossless transmission of various control signals and data.

[0029] In combination with the actual implementation, 6 aramid fibers 3 are used and are respectively distributed symmetrically in a circumferential manner within the accommodation space. Specifically, the aramid fiber 3 is of type 3340 aramid fiber, with a density of 1.44 g / cm³, which is 6 times lighter than steel metal and is suitable for lightweight applications in unmanned aerial vehicles (UAVs). At the same time, it has extremely high tensile strength and elastic modulus and is suitable for withstanding dynamic loads and local impact forces with a maximum breaking force ≥ 4000 N. Thus, it can meet the external stresses during the UAV's hanging process. Moreover, the aramid fiber 3 can be stably used in an environment with a temperature ≥ 180 °C and can form a cooperative temperature-resistant system with the wrapping layer. Furthermore, it has good resistance to weak acids, weak alkalis, and most organic solvents.

[0030] At the same time, in order to meet the heat dissipation needs during long-term use, a plurality of micropores with pore diameters of 5 - 20 μm are provided in the covering film 4 for heat dissipation. In this way, in combination with the way the covering film 4 is lapped and wound around, compared with the traditional outer protection layer structure, the heat dissipation efficiency is increased by more than 30%. The covering film 4 is wound around through a pre-calendering forming process to form a wrapping layer. The thickness of the wrapping layer is only one-third of the thickness of a conventional sheath. Thus, the total weight of the cable itself is greatly reduced, the flexibility of the cable is improved, and the problem of difficult heat dissipation during the cable's operation is solved. During manufacturing, the micropores are formed by a laser etching process, and the density of the micropores is 50 - 200 per cm². In this way, a better heat dissipation effect can be achieved.

[0031] Looking further, the insulating layer 5 is attached to the outside of the electrical unit 1 by means of extrusion using a high-temperature extruder. The thickness of the insulating layer 5 is 0.1 mm ± 0.02 mm, the continuous working voltage is 400 V, and the dielectric strength ≥ 1000 MΩ・km. In this way, it can meet the requirement that the dielectric strength between two-core electrical units 1 reaches 2000 V DC for 1 minute without breakdown, and the temperature resistance range is -65 °C to 200 °C.

[0032] Moreover, in order to enhance the buffering effect between accommodation spaces, a buffer layer composed of silicone rubber is distributed between the wrapping layer and the aramid fiber 3 filling layer. The thickness of the buffer layer is 0.2 mm, and the Shore hardness is 40A ± 5A. In this way, the vibration stress during the flight of the drone can be absorbed, ensuring its stable flight and preventing the entire cable from suffering accidental tensile stress.

[0033] Therefore, during the use of the fiber optic composite cable, its axial tensile strength ≥ 500 N, it is applicable to the flight conditions of the drone with a dynamic load ≥ 10 g, and the attenuation value fluctuation ≤ 0.05 dB / km after 1000 bending fatigue tests.

[0034] The working principle of the present invention is as follows: By installing corresponding interfaces, docking is completed with the power supply end and communication end of the drone. During the operation of the drone, the continuous power supply of the drone itself and other electrical facilities carried by it is completed through the electrical unit 1. The single-mode optical fiber 2 can be used to achieve data transmission, receive the control from the ground end and transmit back the corresponding data. Relying on the high-temperature resistant fluoroplastics as the insulating layer 5, outer sheath 6, and covering film 4, it can still be used stably even when the temperature reaches 180°C.

[0035] In addition, the indicated orientation or positional relationship described in the present invention is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or structure referred to must have a specific orientation, or be operated in a specific orientation structure. Therefore, it should not be construed as a limitation to the present invention.

[0036] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An optoelectronic composite cable suitable for an unmanned aerial vehicle platform, comprising a wrapping layer formed by wrapping a covering film (4), characterized in that: The wrapping layer forms a storage space, in which two-core electrical units (1) and one-core single-mode optical fiber (2) are placed respectively, and a plurality of aramid fibers (3) are distributed in the storage space to form a cable; the electrical unit (1) is provided with an insulating layer (5), and the single-mode optical fiber (2) is provided with an outer cladding (6); the insulating layer (5), the outer cladding (6), and the covering film (4) are all made of high-temperature resistant fluoroplastics composed of ethylene-tetrafluoroethylene copolymer; the thickness of the covering film (4) is 0.05 mm, and the total thickness after wrapping is 0.10 mm±0.02 mm; the outer diameter of the optoelectronic composite cable is 2.2 mm±0.1 mm, and the total weight per meter is ≤12 g.

2. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 1, characterized in that: The conductor (7) of the electrical unit (1) is composed of 19 tinned copper wire strands with a diameter of 0.15 mm, the stranding pitch ratio is ≤12 times, and the resistance of the conductor (7) is ≤50Ω / km.

3. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 1, characterized in that: The single-mode optical fiber (2) is a G657A2 type bend-insensitive optical fiber, the total outer diameter including the outer cladding (6) is 0.5 mm, and the attenuation value at wavelengths of 1310 nm and 1550 nm is ≤0.3 dB / km.

4. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 1, characterized in that: The aramid fibers (3) are six in number and are symmetrically distributed in the accommodating space; the aramid fibers (3) are 3340 type aramid fibers, have a density of 1.44 g / cm³, a maximum breaking force of ≥4000 N, a long-term use temperature of ≥180° C., and can form a synergistic temperature-resistant system with the wrapping layer.

5. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 1, characterized in that: The covering film (4) is provided with a plurality of micropores with a pore size of 5-20 μm; the covering film (4) is wrapped by a pre-calendering forming process to form a wrapping layer.

6. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 5, characterized in that: The micropores are opened by a laser etching process, and the density of the micropores is 50-200 / cm².

7. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 1, characterized in that: The thickness of the insulating layer (5) is 0.1 mm ± 0.02 mm, the continuous working voltage is 400 V, and the dielectric strength is ≥ 1000 MΩ·km.

8. The optoelectronic composite cable suitable for an unmanned aerial vehicle platform according to claim 1, characterized in that: A buffer layer made of silicone rubber is distributed between the wrapping layer and the aramid fiber (3) filling layer. The buffer layer has a thickness of 0.2 mm and a Shore hardness of 40A±5A.

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