Quad coaxial cable for aerospace and preparation method thereof

Abstract

The present invention discloses a quad-coaxial cable for aerospace, including a cable core and a shielding layer. A reinforcing core is arranged at the center of the cable core. The cable core is composed of four coaxial wire cores and the reinforcing core twisted into a cable. The wire core is composed of a conductor wire and an insulation wrapped outside the conductor wire. The outer periphery of the cable core is wrapped with graphite conductive cloth, the outer surface of the graphite conductive cloth is wrapped with a shielding layer, and the outer surface of the shielding layer is extruded with a sheath. The present invention also proposes a corresponding preparation method, including the preparation of graphite conductive cloth: spraying a strong glue on the base cloth tape, grinding and rolling the raw graphite on a substrate, and continuously rolling and tearing the base cloth tape on the substrate, and finally sprinkling graphite powder and rolling forming; winding process: using graphite conductive cloth to wrap the cable core, wrapping the shielding layer and the sheath, and obtaining a finished cable. The present invention imitates the method of preparing graphene by mechanical method, and the graphite is layered and bonded to the outer periphery of the cable core, thereby improving the conductivity of the graphite conductive cloth and reducing the thickness of the graphite conductive cloth, thereby improving the electromagnetic shielding effect of the cable product.

Description

Technical Field

[0001] The present invention relates to the field of cable technology, in particular to a quad-coaxial cable for aerospace and a preparation method thereof. Background Art

[0002] As a new data bus, quad-coaxial cable has the following characteristics: compact structure, small space occupation, high bandwidth, stable transmission signal, support for hot plugging, scalable data transmission rate, flexible and diverse topology, full digital compatibility, ability to establish peer-to-peer networks, and support for both synchronous and asynchronous data transmission modes. Therefore, it has been increasingly widely used in the aviation field and weapon systems.

[0003] As the operating speed of aerospace computers continues to increase, the transmission speed of external connection devices also increases, which puts forward new requirements for cables. At present, there is no fully suitable product in China, and it mainly relies on imports, such as Tyco's CEC-RWC-18664, CEC-RWC-18634, CEC-RWC-18666 and other products. Summary of the invention

[0004] The purpose of the present invention is to fill the technical gaps in the above-mentioned fields, and to propose a quad-coaxial cable for aerospace and a preparation method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] Quad-coaxial cable for aerospace use includes a cable core and a shielding layer. A reinforcing core is arranged at the center of the cable core. The cable core is composed of four coaxial wire cores and the reinforcing core twisted into a cable. The wire core is composed of a conductor wire and an insulation wrapped around the conductor wire. The outer periphery of the cable core is wrapped with graphite conductive cloth, the outer surface of the graphite conductive cloth is wrapped with a shielding layer, and the outer surface of the shielding layer is extruded with a sheath.

[0007] Preferably, the conductor wire is made of multiple strands of silver-plated copper wires twisted concentrically and in the same direction, with the inner and outer layers having the same pitch, and the conductor surface is smooth and round.

[0008] Preferably, the insulation is formed by extrusion of expanded polytetrafluoroethylene, which is then sintered at high temperature to form an insulation layer, the power saving constant of which is ≤1.45, so that the cable attenuation is ≤0.730dB@1GHz.

[0009] Preferably, the reinforcing core is made of twisted aramid fiber filaments with a temperature resistance of -85°C to +400°C.

[0010] Preferably, the graphite conductive cloth is composed of a base cloth tape, a strong adhesive layer uniformly coated on the surface of the base cloth tape, a graphene layer adhered to the outside of the strong adhesive layer, and a graphite powder layer hot-rolled on the outside of the graphene layer. The base cloth tape is specifically a nylon tape or a rubber cloth bag.

[0011] Preferably, the shielding layer includes an inner shielding layer and an outer shielding layer, both of which are woven from silver-plated flat copper wires. The weaving density of the outer shielding layer is 50-80 meshes, and the weaving density of the inner shielding layer is 90-120 meshes. The shielding density of the two layers is not less than 95%, and the shielding effectiveness is ≥90dB@1GHz.

[0012] Preferably, the material of the sheath is soluble polytetrafluoroethylene, with a tensile strength of ≥28MPa, an elongation at break ≥300%, and a temperature resistance of -65°C to +250°C.

[0013] The present invention also proposes a method for preparing a quad-coaxial cable for aerospace use, which is characterized by comprising the following steps:

[0014] S1, spray the aforementioned base fabric with strong glue, keep it at a certain humidity, and set it aside;

[0015] S2, grinding the raw graphite into graphite sheets by using a mortar grinder, and pressing the graphite sheets onto a flat and neat substrate by using a hot roller at 30-100°C;

[0016] S3, rolling the base cloth tape with strong glue on the substrate with graphite sheet, and then tearing it off, repeating the rolling and tearing operations 3-8 times, so that the base cloth tape is continuously bonded to the graphite sheet;

[0017] S4, sprinkling graphite powder on the base cloth tape bonded with the graphite sheet, and then placing it in a high-temperature graphite coating machine, continuing to roll and polish at 80-150° C. to obtain a relatively uniform graphite layer, thereby preparing a finished graphite conductive cloth;

[0018] S5, the cable core is wrapped with graphite conductive cloth, the shielding layer is wrapped, and then the soluble polytetrafluoroethylene is wrapped, and an extruder is used to extrude and form a sheath, thereby obtaining a finished quad-coaxial cable.

[0019] Preferably, the main component of the super glue is cyanoacrylate resin.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention imitates the method for preparing graphene by mechanical method, and grinds the raw graphite into graphite sheets by mortar grinder. At this time, the graphite sheets are layered structures composed of multiple layers of graphene. The graphite sheets are rolled on the substrate to make the graphite sheets further produce interlayer shedding. At the same time, strong glue is applied on the base cloth tape to make the base cloth tape have the function of tape. The tape is continuously rolled and torn on the graphite sheet substrate to obtain a single-layer or few-layer graphene structure, thereby constructing a graphite conductive cloth including a graphite powder layer, a graphene layer, a strong glue layer and a base cloth tape. On the one hand, due to the high interlayer continuity of the graphene prepared by the mechanical method, and the good flexibility and high strength of the graphene, the conductivity is higher and the conductivity is more stable. Even if the graphite powder layer produces discontinuous holes during use and causes the conductivity to fail, the graphene layer still ensures the conductivity of the conductive cloth; on the other hand, the thickness of the graphite conductive cloth is reduced, and the weight of the cable is reduced, so that the cable product of the present invention is suitable for aerospace.

[0022] 2. The present invention adopts graphite conductive cloth together with inner shielding layer and outer shielding layer to form a three-layer shielding layer, which gradually offsets electromagnetic interference in a way that the shielding resistance gradually increases from the inside to the outside; at the same time, the graphite powder layer of the graphite conductive cloth has a lubricating effect, acts as an intermediate bridge for the insulation layer and the shielding layer of the cable, and has a lubricating effect on both sides, which can prevent the deformation of the cable during use from causing a large change in the spacing between the insulation and the conductor, reduce the noise generated during the transmission process, and further improve the electromagnetic resistance of the cable.

[0023] 3. The present invention adopts reasonable material distribution, so that the cable product has the following advantages: 1) small outer diameter and light weight, 2) high and low temperature resistance, 3) high tensile strength, 4) small attenuation, suitable for long-distance transportation, especially for connecting aerospace computers with external equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the quad-coaxial cable for aerospace use proposed by the present invention;

[0025] Figure 2 This is a diagram of the interlayer structure of the graphite conductive cloth of the quad-coaxial cable for aerospace use proposed by the present invention;

[0026] In the figure: 1 conductor wire, 2 insulation, 3 reinforcement core, 4 graphite conductive cloth, 5 shielding layer, 6 sheath. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Reference Figure 1-2, a quad-coaxial cable for aerospace, including a cable core and a shielding layer 5, a reinforcing core 3 is arranged at the center of the cable core, the cable core is composed of four coaxial wire cores and the reinforcing core 3 twisted into a cable, the wire core is composed of a conductor wire 1 and an insulation 2 wrapped outside the conductor wire 1; the outer periphery of the cable core is wrapped with a graphite conductive cloth 4, the outer surface of the graphite conductive cloth 4 is wrapped with a shielding layer 5, and the outer surface of the shielding layer 5 is extruded with a sheath 6; the conductor wire 1 is made of multiple strands of silver-plated copper wires twisted concentrically and in the same direction, and the pitch of the inner and outer layers is consistent, the surface of the conductor is smooth and round, the insulation 2 is extruded from foamed polytetrafluoroethylene, and the reinforcing core 3 is twisted Aramid fiber filaments are temperature-resistant from -85°C to +400°C. The graphite conductive cloth 4 is composed of a base cloth tape, a strong adhesive layer evenly coated on the surface of the base cloth tape, a graphene layer adhered to the outside of the strong adhesive layer, and a graphite powder layer hot-rolled on the outside of the graphene layer. The base cloth tape is specifically a nylon tape or a rubber cloth bag. The shielding layer 5 includes an inner shielding layer and an outer shielding layer. Both the inner shielding layer and the outer shielding layer are woven from silver-plated flat copper wires. The weaving density of the outer shielding layer is 50-80 meshes, and the weaving density of the inner shielding layer is 90-120 meshes. The material of the sheath 6 is soluble polytetrafluoroethylene.

[0029] The present invention adopts reasonable material distribution, and its cable products have the following advantages: 1) small outer diameter and light weight: the insulation adopts foamed polytetrafluoroethylene. Under normal circumstances, the dielectric constant of polytetrafluoroethylene is 2.1. By foaming the material, the insulation dielectric constant is reduced to about 1.45, which is smaller in outer diameter and lighter in weight than similar cables with an impedance of 110Ω; 2) high and low temperature resistance: the cable insulation and sheath adopt high temperature resistant fluorine-containing materials, and the long-term use temperature of the cable is -65 to 250°C, which is suitable for use in harsh aerospace environments; 3) high tensile strength: the reinforcing core of the cable adopts aramid fiber yarn, which improves the overall tensile strength of the cable; 4) low attenuation: the silver-plated copper conductor and foamed polytetrafluoroethylene material are selected to reduce the dielectric constant of the dielectric layer, reduce the signal attenuation during cable transmission, and improve the bandwidth. The maximum transmission frequency reaches 1GHz, and the attenuation is not more than 0.730dB@1GHz.

[0030] The present invention also proposes a method for preparing a quad-coaxial cable for aerospace, comprising the following steps:

[0031] S1, spray the base cloth with super glue, the main component of which is cyanoacrylate resin, and keep a certain humidity for standby use;

[0032] S2, grinding the raw graphite into graphite sheets by using a mortar grinder, and pressing the graphite sheets onto a flat and neat substrate by using a hot roller at 30-100°C;

[0033] S3, rolling the base cloth tape with strong glue on the substrate with graphite sheet, and then tearing it off, repeating the rolling and tearing operations 3-8 times, so that the base cloth tape is continuously bonded to the graphite sheet;

[0034] S4, sprinkle graphite powder on the base cloth tape bonded with the graphite sheet, then place it in a high-temperature graphite coating machine, continue rolling and grinding at 80-150° C. to obtain a relatively uniform graphite layer, thereby preparing a finished graphite conductive cloth 4;

[0035] S5, wrapping the cable core with graphite conductive cloth 4, encapsulating the shielding layer 5, and then encapsulating the soluble polytetrafluoroethylene, and forming the sheath 5 by extruding with an extruder, thereby obtaining a finished quad-coaxial cable.

[0036] The present invention grinds the raw graphite into graphite sheets by a mortar grinder. At this time, the graphite sheets are layered structures composed of multiple layers of graphene. The graphite sheets are rolled on a substrate to further cause interlayer shedding of the graphite sheets. At the same time, a strong glue is applied on the base cloth tape to make the base cloth tape have the function of a tape. The tape is continuously rolled and torn on the graphite sheet substrate to obtain a single-layer or few-layer graphene structure, thereby improving the conductivity of the graphite conductive cloth 4 while also reducing the thickness of the graphite conductive cloth 4, reducing the weight of the cable, and making the cable product of the present invention suitable for aerospace. At the same time, the graphite conductive cloth 4, the inner shielding layer, and the outer shielding layer together form a three-layer shielding layer, which gradually offsets electromagnetic interference in a manner in which the shielding resistance gradually increases from the inside to the outside, thereby improving the electromagnetic shielding property of the present invention.

[0037] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A quad-coaxial cable for aerospace use, comprising a cable core and a shielding layer (5), characterized in that: A reinforcing core (3) is provided at the center of the cable core. The cable core is composed of four coaxial wire cores and the reinforcing core (3) twisted into a cable. The wire core is composed of a conductor wire (1) and an insulation (2) wrapped around the conductor wire (1). The outer periphery of the cable core is wrapped with a graphite conductive cloth (4). The outer surface of the graphite conductive cloth (4) is wrapped with a shielding layer (5). The shielding layer (5) is extruded with a sheath (6). The graphite conductive cloth (4) is composed of a base cloth tape, a strong adhesive layer evenly coated on the surface of the base cloth tape, a graphene layer adhered to the outside of the strong adhesive layer, and a graphite powder layer hot-rolled on the outside of the graphene layer. The base cloth tape is specifically a nylon tape or a rubber cloth bag; A method for preparing a quad coaxial cable for aerospace use comprises the following steps: S1, spray the base cloth with super glue, keep it at a certain humidity, and keep it ready for use; S2, grinding the raw graphite into graphite sheets by using a mortar grinder, and pressing the graphite sheets onto a flat and neat substrate by using a hot roller at 30-100°C; S3, rolling the base cloth tape with strong glue on the substrate with graphite sheet, and then tearing it off, repeating the rolling and tearing operations 3-8 times, so that the base cloth tape is continuously bonded to the graphite sheet; S4, sprinkling graphite powder on the base cloth tape bonded with the graphite sheet, and then placing it in a high-temperature graphite coating machine, and continuing to roll and grind it at 80-150° C. to obtain a relatively uniform graphite layer, thereby preparing a finished graphite conductive cloth (4); S5, using graphite conductive cloth (4) to wrap the cable core, wrapping the shielding layer (5), and then wrapping soluble polytetrafluoroethylene, and using an extruder to extrude to form a sheath (6), thereby obtaining a finished quad-coaxial cable.

2. The aerospace quad coaxial cable according to claim 1, characterized in that: The conductor wire (1) is made of a plurality of silver-plated copper wires twisted concentrically and in the same direction, with the inner and outer layers having the same pitch, and the conductor surface is smooth and round.

3. The aerospace quad coaxial cable according to claim 1, characterized in that: The insulation (2) is formed by extrusion of foamed polytetrafluoroethylene.

4. The aerospace quad coaxial cable according to claim 1, characterized in that: The reinforcing core (3) is made of twisted aramid fiber yarn and has a temperature resistance of -85°C to +400°C.

5. The aerospace quad coaxial cable according to claim 1, characterized in that: The shielding layer (5) comprises an inner shielding layer and an outer shielding layer, the inner shielding layer and the outer shielding layer are both woven from silver-plated flat copper wires, the braiding density of the outer shielding layer is 50-80 meshes, and the braiding density of the inner shielding layer is 90-120 meshes.

6. The aerospace quad coaxial cable according to claim 1, characterized in that: The main component of the super glue is cyanoacrylate resin.

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