Light aviation fire-resistant cable and preparation method thereof

Abstract

The invention discloses a light aviation fire-resistant cable and a preparation method thereof. The light aviation fire-resistant cable comprises a cable core, a shielding layer and a composite sheath layer, wherein the shielding layer and the composite sheath layer sequentially coat the cable core from inside to outside; the cable core comprises an insulating wire core; each insulating wire core comprises a twisted nickel-plated conductor, a fireproof layer and a composite insulating layer, wherein the fireproof layer and the composite insulating layer sequentially wrap the twisted nickel-plated conductor from inside to outside. The fireproof layer comprises quartz fibers, the quartz fiber bundles are wound outside the stranded nickel-plated conductor, and the fireproof layer is formed by high-temperature vulcanization after the quartz fibers are coated with silicone rubber emulsion; the fireproof layer is wrapped by a composite insulating layer. The shielding layer is a nickel-plated round copper wire braided layer; and a composite sheath layer is arranged outside the shielding layer. The cable has the advantages of being long in service life under the high-temperature condition, small in size, light in weight, resistant to high temperature, good in insulation performance, good in environment resistance, resistant to vibration and impact and the like.

Description

Technical Field

[0001] The invention belongs to the field of cable manufacturing, in particular to a light aviation fire-resistant cable and a preparation method thereof. Background Art

[0002] For the electronic circuit systems in aerospace vehicles and the electronic components that constitute the payload, including wires and cables, efforts must be made to reduce their weight in order to free up more weight and space so that the aerospace vehicle can carry more other equipment, thereby improving the efficient operation of the aerospace vehicle.

[0003] In the application of aerospace engines, the cable is required to have fire resistance, be able to maintain normal operation for a certain period of time under flame combustion, and be able to be used normally for 15 minutes under high temperature conditions of 1100°C. Especially during combustion, accompanied by water spray and mechanical shock and vibration, the cable can still maintain the integrity of the line operation, and has the performance of resistance to wear, moisture and aviation fluids, and can withstand severe vibration and bending.

[0004] The conductor of the existing fire-resistant cable is usually made of multiple nickel-plated round copper wires twisted together, and the conductor is wrapped with mica tape to form an insulating core, and then two insulating cores are twisted into a cable core, and a layer of metal wire is woven outside the cable core to form a shielding layer. At present, the outer diameter of the fire-resistant cable is large (the outer diameter of the fire-resistant cable used in the aerospace engine cabin and engine area is required to be as small as possible), the weight is heavy (the fire-resistant cable used in the aerospace engine cabin and engine area is required to be as light as possible), and the structural design and material selection are unreasonable, which cannot meet the requirements of the aerospace engine cabin and engine area, fire resistance of 1100℃, and 15 minutes.

[0005] Aviation fire-resistant cables are used in ultra-high temperature environments in aircraft engine cabins and engine areas, and require higher fire resistance, weight, outer diameter and other requirements. However, the existing cable fire-resistant layer is wrapped with mica tape, which is easy to fall off in the flame. The cable has a large outer diameter, heavy weight, and low fire resistance, which cannot meet the needs of the aerospace field. Summary of the invention

[0006] The purpose of the present invention is to provide a light aviation fire-resistant cable with long service life under high temperature conditions, good environmental resistance, light weight and small outer diameter, and a preparation method thereof in view of the deficiencies in the prior art.

[0007] The technical purpose of the present invention is achieved by the following technical solutions: A light aviation fire-resistant cable, comprising a cable core and a shielding layer and a composite sheath layer sequentially coated on the outside of the cable core from the inside to the outside; the cable core comprises an insulating core; the insulating core comprises a twisted nickel-plated conductor and a fire-resistant layer and a composite insulating layer sequentially coated on the outside of the twisted nickel-plated conductor from the inside to the outside; the fire-resistant layer comprises quartz fiber, the quartz fiber bundle is wound around the twisted nickel-plated conductor and the quartz fiber is coated with silicone rubber emulsion and then vulcanized at high temperature to form a fire-resistant layer; the fire-resistant layer is wrapped with a composite insulating layer; the shielding layer is a braided layer of nickel-plated round copper wires; a composite sheath layer is arranged outside the shielding layer.

[0008] Preferably, the composite insulation layer includes an inner insulation layer wrapped around the fire-resistant layer and an outer insulation layer wrapped around the inner insulation layer; the inner insulation layer is a polyimide tape wrapping layer, and the outer insulation layer is a microporous polytetrafluoroethylene tape wrapping layer, and the inner insulation layer and the outer insulation layer are sintered at high temperature to form a composite insulation layer.

[0009] Preferably, the composite sheath layer comprises an inner sheath layer and an outer sheath layer; a microporous polytetrafluoroethylene tape is wrapped around the shielded cable to form the inner sheath layer, and microporous polytetrafluoroethylene is reversely wrapped around the inner sheath layer to form the outer sheath layer; the inner sheath layer and the outer sheath layer are sintered at high temperature to form a composite sheath layer.

[0010] Preferably, the twisted nickel-plated conductor is formed by twisting a plurality of nickel-plated round copper wires or nickel-plated copper alloys, and the nickel content of the nickel-plated layer of the nickel-plated round copper wires or nickel-plated copper alloys is not less than 27%.

[0011] Preferably, the stranded nickel-plated conductors are stranded in the same direction in a 1+6+12 arrangement, the stranding pitch ratio is 8-16, and the stranding direction is S.

[0012] Preferably, the nickel content of the nickel-plated layer of the nickel-plated round copper wire used for weaving the shielding layer is not less than 27%, and the weaving density is not less than 85%.

[0013] Preferably, the cable core is formed by twisting two insulated wire cores, the twisting direction is S direction, and the twisting pitch ratio is 8-16.

[0014] Preferably, the quartz fiber is a high-purity quartz fiber with a linear density ranging from 200D to 600D.

[0015] The method for preparing the above-mentioned light aviation fire-resistant cable comprises the following steps: Step 1, preparation of a stranded nickel-plated conductor: 19 nickel-plated copper alloy or copper round wires with a nickel-plated layer content of not less than 27% are used, and are twisted in the same direction according to a pitch ratio of 8 to 16 and an arrangement of 1+6+12, and the twisting direction is S direction to obtain a twisted nickel-plated conductor; Step 2, preparation of a refractory layer of the insulating core: High-purity quartz fiber with a linear density range of 200D to 600D is tightly wrapped around the outside of the stranded nickel-plated conductor using a bundle winding process; the bundle winding density is ensured by controlling the bundle winding pitch, the number of bundle windings and selecting quartz fibers with different linear densities, so that the bundled quartz fiber layer is tightly attached to the stranded nickel-plated conductor, and the bundle direction is the Z direction; After the quartz fiber is bundled, a process method of coating with silicone rubber emulsion and vulcanizing is adopted. Through the coating and drying process, the gaps in the bundled quartz fiber are filled, and the speed of coating with silicone rubber emulsion is controlled, and the thickness of the silicone rubber emulsion coating layer is adjusted, which ranges from 10um to 50um, and the drying time, and the quartz fiber bundled outside the twisted nickel-plated conductor is made into a fire-resistant layer; Step 3, preparation of the composite insulation layer of the insulated wire core: using a thickness range of 0.02mm to 0.03mm and a width range of 5mm A polyimide tape with a width of ~20mm is then wrapped in an overlapping wrapping process in the S direction, tightly wrapped on the outside of the fire-resistant layer, with an overlapping rate of 10% to 50%, to form an inner insulating layer; a microporous polytetrafluoroethylene tape with a thickness range of 0.05mm to 0.07mm and a width range of 5mm to 25mm is then used, and then wrapped in an overlapping wrapping process in the Z direction, tightly wrapped on the outside of the inner insulating layer to form an outer insulating layer; Then, a sintering process is adopted to fuse the polyimide tape and the microporous polytetrafluoroethylene tape tightly together through the sealing of the microporous polytetrafluoroethylene tape, and a composite insulating layer is made by controlling the wrapping overlap rate of the microporous polytetrafluoroethylene tape within a range of 20% to 80% and the sintering temperature within a range of 400°C to 500°C. Step 4: Preparation of cable core: Two insulated wire cores are twisted together to form a cable core, the twisting pitch ratio of the cable core is 8-16, and the twisting direction is S direction; Step 5: Preparation of shielding layer: A plurality of nickel-plated round copper wires with a nickel-plated content of not less than 27% are combined into strands, and then the combined strands of nickel-plated round copper wires are tightly wrapped on the outside of the cable core by a braiding process, and the braiding density of the shielding layer is controlled to be not less than 85% and the braiding angle is controlled within the range of 46° to 72° by controlling the number of combined nickel-plated round copper wires, the number of braiding spindles and the braiding pitch, so as to obtain a shielding layer; Step 6: Preparation of composite sheath layer: Use microporous polytetrafluoroethylene tape with a thickness range of 0.05mm to 0.07mm and a width range of 5mm to 25mm, wrap it tightly on the outside of the shielding layer with an overlap rate of 10% to 50%, and wrap it in the Z direction to form an inner sheath layer; Then, a microporous polytetrafluoroethylene tape with a thickness ranging from 0.05 mm to 0.07 mm and a width ranging from 5 mm to 25 mm is used, and an overlap rate of 10% to 50% is used for wrapping, and the wrapping direction is S direction to form an outer sheath layer; Then, a sintering process is used to tightly fuse the inner sheath layer and the outer sheath layer together, and the wrapping overlap rate of the microporous polytetrafluoroethylene tape is controlled within a range of 20% to 80%, and the sintering temperature range is 400°C to 500°C to form a composite sheath layer; the finished cable manufacturing is completed.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention has the properties of long service life under high temperature conditions, small size, light weight, high temperature resistance, good environmental resistance, good insulation performance, and vibration and impact resistance. The outer diameter of the cable is more than 10% smaller than the outer diameter of existing products on the market, and the weight is more than 15% lighter than the weight of existing products on the market. It can meet the long-term use of -65 to 260°C and short-term use of 1100°C for more than 15 minutes. Its insulation resistance is not less than 50Ω, the insulation layer does not peel off or fall off, and the duration of signal interruption is not more than 125ms. The present invention can fully meet the needs of aerospace and other fields, and can ensure the reliable operation of the control system used in the aerospace engine cabin and engine area and the accurate transmission of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention; Figure numerals: 1—stranded nickel-plated conductor; 2—fire-resistant layer; 3—composite insulation layer; 31—inner insulation layer; 32—outer insulation layer; 4—shielding layer; 5—composite sheath layer; 51—inner sheath layer; 52—outer sheath layer. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0021] like Figure 1 As shown, a light aviation fire-resistant cable comprises a cable core and a shielding layer 4 and a composite sheath layer 5 which are sequentially coated on the outside of the cable core from the inside to the outside; the cable core comprises an insulating core, the insulating core comprises a twisted nickel-plated conductor 1 and a fire-resistant layer 2 and a composite insulating layer 3 which are sequentially coated on the outside of the twisted nickel-plated conductor 1 from the inside to the outside; the fire-resistant layer 2 comprises quartz fiber, the quartz fiber bundle is wound around the twisted nickel-plated conductor 1 and the quartz fiber is coated with silicone rubber emulsion and then vulcanized at high temperature to form the fire-resistant layer 2; the fire-resistant layer 2 is wrapped around the composite insulating layer 3; the shielding layer 4 is a nickel-plated round copper wire braided layer; and the shielding layer 4 is provided with a composite sheath layer 5. Among them, the fire-resistant layer 2 formed by the quartz fiber bundle being wound around the twisted nickel-plated conductor 1 and the quartz fiber being coated with silicone rubber emulsion and then vulcanized at high temperature improves the electrical performance and fire-resistant performance of the cable as well as the service life and reliability of the product. The cable made of the fire-resistant layer 2 avoids the fire-resistant layer 2 from falling off easily in the flame. At the same time, the formed cable has the advantages of light weight, small outer diameter and long service life under high temperature conditions.

[0022] In actual use, the stranded nickel-plated conductor 1 is formed by twisting a plurality of nickel-plated round copper wires or nickel-plated copper alloys, and the nickel content of the nickel-plated layer of the nickel-plated round copper wires or nickel-plated copper alloys is not less than 27%. The adoption of this technical measure enables the cable to have enhanced corrosion resistance, improved wear resistance, and good electrical conductivity, thereby improving the cable's strong corrosion resistance, high wear resistance, and good high temperature resistance. In actual use, the stranded nickel-plated conductor 1 is generally formed by twisting 19 nickel-plated round copper wires or nickel-plated copper alloys, and the stranded nickel-plated conductor 1 is twisted in the same direction in a 1+6+12 arrangement, with a twisted pitch ratio of 8~16, and a twisting direction of S. The adoption of this technical measure enables the stranded nickel-plated conductor 1 to have good flexibility; it can effectively improve the conductor's tensile strength and torsional resistance, and have good flexibility.

[0023] Among them, the quartz fiber of the fire-resistant layer 2 adopts high-purity quartz fiber with a linear density range of 200D to 600D. The high-purity quartz fiber is made of high-purity silicon dioxide quartz stone after high-temperature melting and drawing. It has excellent mechanical properties, high tensile strength, and no microcracks on the surface. It also has excellent electrical insulation properties, low dielectric constant and dielectric loss coefficient. The long-term use temperature of quartz fiber can reach 1200℃, and the softening point temperature is as high as 1700℃. At the same time, it has excellent dielectric properties and good chemical stability, and will not melt or evaporate when heated to 1649℃. The process method of coating silicone rubber emulsion and vulcanization is adopted. Through the coating and drying process, the gaps in the bundled quartz fiber are filled, and the quartz fiber bundled outside the conductor is bonded into a complete fire-resistant layer 2. The fire-resistant layer 2 obtained by this technical measure makes the cable have a small bundle outer diameter, which reduces the product outer diameter and product weight of the aviation fire-resistant cable. By adopting this technical measure, the fire-resistant layer 2 has the advantages of excellent mechanical properties, tensile properties, electrical insulation properties, high temperature resistance and long service life under high temperature conditions. Specifically, the outer diameter of the fire-resistant cable made by adopting this technical measure is more than 10% smaller than the outer diameter of the existing products on the market, and the weight is more than 15% lighter than the existing products on the market. In an environment of up to 1100°C, the normal service time is not less than 15 minutes.

[0024] The composite insulating layer 3 includes an inner insulating layer 31 wrapped around the outside of the fire-resistant layer 2 and an outer insulating layer 32 wrapped around the outside of the inner insulating layer 31; the inner insulating layer 31 is a polyimide tape wrapped layer, and the outer insulating layer 32 is a microporous polytetrafluoroethylene tape wrapped layer. The inner insulating layer 31 and the outer insulating layer 32 are sintered at high temperature to form the composite insulating layer 3. Specifically, the composite insulating layer 3 is wrapped on the fire-resistant layer 2, and the composite insulating layer 3 is composed of the inner insulating layer 31 and the outer insulating layer 32. The inner insulating layer 31 is made of a polyimide tape with the characteristics of a wide operating temperature range, high mechanical properties, and good insulation performance. The outer insulating layer 32 is made of a microporous polytetrafluoroethylene tape, and then sintered in a sintering furnace to make the inner insulating layer 31 and the outer insulating layer 32 tapes bonded to each other to form a composite insulating layer, and an insulated wire core is made. Among them, polyimide has high strength and high modulus, can withstand high temperatures of 400°C, and is also resistant to low temperatures and has good insulation performance. The microporous polytetrafluoroethylene tape has excellent high and low temperature resistance, corrosion resistance, weather resistance, as well as good self-lubrication and electrical properties. The combination of the inner insulating layer 31 and the outer insulating layer 32 can give full play to their respective advantages, improve the overall performance of the composite insulating layer 3, enhance wear resistance and corrosion resistance, and at the same time make the composite insulating layer 3 have good electrical properties, thermal stability, water resistance and oil resistance. The composite insulating layer 3 prepared by adopting this technical measure has the advantages of long service life under high temperature conditions, light weight, good insulation performance and good environmental resistance, so that the cable using the composite insulating layer 3 has the advantages of long service life under high temperature conditions, light weight, good insulation performance and good environmental resistance.

[0025] The composite sheath layer 5 includes an inner sheath layer 51 and an outer sheath layer 52; the inner sheath layer 51 is formed by wrapping a microporous polytetrafluoroethylene tape around the outside of the shielded cable, and the outer sheath layer 52 is formed by wrapping microporous polytetrafluoroethylene in the reverse direction outside the inner sheath layer 51; the inner sheath layer 51 and the outer sheath layer 52 are sintered at high temperature to form the composite sheath layer 5. Microporous polytetrafluoroethylene has excellent high temperature resistance, corrosion resistance and insulation properties. By wrapping in a forward and reverse cross manner, it is ensured that the wrapping layer is tight and uniform without gaps. Therefore, the adoption of this technical measure can enhance the insulation performance and mechanical strength of the cable, and further improve the high temperature resistance, corrosion resistance, insulation performance, durability and reliability of the cable.

[0026] A method for preparing a light aviation fire-resistant cable, specifically comprising the following steps: Step 1: Preparation of stranded nickel-plated conductor 1: 19 nickel-plated copper alloy or copper round wires with a nickel-plated layer content of not less than 27% are twisted in the same direction according to a pitch ratio of 8 and an arrangement of 1+6+12, and the twisting direction is S direction to obtain a twisted nickel-plated conductor 1. The technical measures can make the twisted nickel-plated conductor 1 have good flexibility, effectively improve the tensile strength and torsional resistance of the conductor, and have good flexibility.

[0027] Step 2: Preparation of the fire-resistant layer 2 of the insulating core: High-purity quartz fiber with a linear density of 200D is used to tightly wrap the outside of the twisted nickel-plated conductor 1 by a bundle winding process; the bundle winding density is ensured by controlling the bundle winding pitch, the number of bundle windings and selecting quartz fibers with different linear densities, so that the bundled quartz fiber layer is tightly attached to the twisted nickel-plated conductor 1, and the bundle direction is the Z direction; After the quartz fiber is bundled, the silicone rubber emulsion is coated and vulcanized. Through the coating and drying process, the gaps in the bundled quartz fiber are filled, and the speed of coating the silicone rubber emulsion is controlled, and the thickness of the silicone rubber emulsion coating layer is adjusted to a range of 10um, as well as the drying time, and the quartz fiber bundled outside the twisted nickel-plated conductor 1 is made into a refractory layer 2. The above technical measures are adopted to make the silicone rubber coating and the quartz fiber closely combined, thereby improving the overall performance and stability of the product. At the same time, the refractory layer 2 prepared by the above technical measures has excellent mechanical properties, tensile properties, electrical insulation properties, high temperature resistance, and the advantages of long service life and thin thickness under high temperature conditions.

[0028] Step 3, preparation of the composite insulating layer 3 of the insulating core: using a polyimide tape with a thickness range of 0.02 mm and a width range of 5 mm, and then using an overlapping wrapping process, the wrapping direction is S direction, tightly wrapped on the outside of the fire-resistant layer 2, and the overlapping rate is 10%, to form an inner insulating layer 31; then using a microporous polytetrafluoroethylene tape with a thickness range of 0.05 mm and a width range of 5 mm, and then using an overlapping wrapping process, the wrapping direction is Z direction, tightly wrapped on the outside of the inner insulating layer 31, to form an outer insulating layer 32; Then, a sintering process is adopted to fuse the polyimide tape and the microporous polytetrafluoroethylene tape tightly together through the sealing of the microporous polytetrafluoroethylene tape, and the composite insulation layer 3 is made by controlling the wrapping overlap rate of the microporous polytetrafluoroethylene tape within a range of 20% and the sintering temperature range of 400°C. The dense composite insulation layer 3 made by this technical measure has excellent uniformity and integrity. At the same time, the composite insulation layer 3 made by this technical measure has the advantages of long service life under high temperature conditions, light weight, and good insulation performance.

[0029] Step 4: Preparation of cable core: Two insulated wire cores are twisted together to form a cable core, the twisting pitch ratio of the cable core is 8-16, and the twisting direction is S direction; Step 5: Preparation of shielding layer 4: A plurality of nickel-plated round copper wires with a nickel-plated content of not less than 27% are combined into strands, and then the combined strands of nickel-plated round copper wires are tightly wrapped on the outside of the cable core by a braiding process. By controlling the number of combined nickel-plated round copper wires, the number of braiding spindles and the braiding pitch, the braiding density of the shielding layer 4 is not less than 85% and the braiding angle is controlled within the range of 46°, thereby obtaining the shielding layer 4. The shielding layer 4 obtained by adopting this technical measure is high-density, uniform and stable. At the same time, the shielding layer 4 also has excellent corrosion resistance and oxidation resistance, which can effectively isolate external electromagnetic interference, protect the signal transmission quality in the cable core, and extend the service life of the cable.

[0030] Step 6: Preparation of composite sheath layer 5: A microporous polytetrafluoroethylene tape with a thickness range of 0.05 mm and a width range of 5 mm is used, and is wrapped tightly around the outside of the shielding layer 4 with an overlap rate of 10%, and the wrapping direction is the Z direction, to form an inner sheath layer 51; Then, a microporous polytetrafluoroethylene tape with a thickness range of 0.05 mm and a width range of 5 mm is used, and an overlap rate of 10% is used for wrapping, and the wrapping direction is S direction to form an outer sheath layer 52; Then, a sintering process is used to tightly fuse the inner sheath layer 51 and the outer sheath layer 52 together, and the wrapping overlap rate of the microporous polytetrafluoroethylene tape is controlled to be within a range of 20%, and the sintering temperature range is 400°C, so as to form a composite sheath layer 5; the finished cable is manufactured. Microporous polytetrafluoroethylene has excellent high temperature resistance, corrosion resistance and insulation properties. By wrapping in a forward and reverse cross manner, it is ensured that the wrapping layer is tight and uniform without gaps. Therefore, the composite sheath layer 5 prepared by this technical measure can enhance the insulation performance and mechanical strength of the cable, and further improve the high temperature resistance, corrosion resistance, insulation performance, durability and reliability of the cable.

[0031] The light aviation fire-resistant cable made by the above technical measures has the properties of small size, light weight, high temperature resistance, oil resistance, vibration and impact resistance, etc. The outer diameter of the cable is more than 10% smaller than the outer diameter of existing products on the market, and the weight is more than 15% lighter than the weight of existing products on the market. It can meet the long-term -65 ~ 260 ℃, short-term 1100 ℃ environment for more than 15 minutes, and its insulation resistance is not less than 50Ω, the insulation layer does not peel off or fall off, and the duration of signal interruption is not more than 125ms. The light aviation fire-resistant cable made by the above technical measures can ensure the reliable operation of the control system used in the aerospace engine cabin and engine area and the accurate transmission of data.

[0032] Example 2 The other contents of this embodiment are the same as those of Embodiment 1, except that: Step 1: Preparation of stranded nickel-plated conductor 1: 19 nickel-plated copper alloy or copper round wires with a nickel-plated layer content of not less than 27% are used, and are twisted in the same direction according to a pitch ratio of 12 and an arrangement of 1+6+12, and the twisting direction is S direction, to obtain a twisted nickel-plated conductor 1; Step 2, preparation of a refractory layer 2 of the insulating core: High-purity quartz fiber with a linear density range of 400D is used to tightly wrap the outside of the twisted nickel-plated conductor 1 by a bundle winding process; the bundle winding density is ensured by controlling the bundle winding pitch, the number of bundle windings and selecting quartz fibers with different linear densities, so that the bundled quartz fiber layer is tightly attached to the twisted nickel-plated conductor 1, and the bundle direction is the Z direction; After the quartz fiber is bundled, a silicone rubber emulsion is applied and vulcanized. Through the coating and drying process, the gaps in the bundled quartz fiber are filled, and the speed of applying the silicone rubber emulsion is controlled, the thickness of the silicone rubber emulsion coating layer is adjusted, and the drying time is adjusted to form a refractory layer 2 of the quartz fiber bundled on the outside of the twisted nickel-plated conductor 1; Step 3, preparation of the composite insulating layer 3 of the insulating core: a polyimide tape with a thickness range of 0.025 mm and a width range of 12.5 mm is used, and then a covering wrapping process is adopted, the wrapping direction is S direction, and it is tightly wrapped on the outside of the refractory layer 2, and the covering rate is 30%, to form an inner insulating layer 31; then a microporous polytetrafluoroethylene tape with a thickness range of 0.06 mm and a width range of 11 mm is used, and then a wrapping process is adopted, and then an overlapping wrapping process is adopted, the wrapping direction is Z direction, and it is tightly wrapped on the outside of the inner insulating layer 31 to form an outer insulating layer 32; Then, a sintering process is adopted to fuse the polyimide tape and the microporous polytetrafluoroethylene tape tightly together by sealing the microporous polytetrafluoroethylene tape, and the composite insulating layer 3 is manufactured by controlling the wrapping overlap rate of the microporous polytetrafluoroethylene tape within a range of 50% and the sintering temperature within a range of 450° C.; Step 4: Preparation of cable core: Two insulated wire cores are twisted together to form a cable core, the twisting pitch ratio of the cable core is 12, and the twisting direction is S direction; Step 5: Preparation of shielding layer 4: A plurality of nickel-plated round copper wires having a nickel-plated content of not less than 27% are combined into strands, and then the combined strands of nickel-plated round copper wires are tightly wrapped on the outside of the cable core by a braiding process, and the number of combined nickel-plated round copper wires, the number of braiding spindles and the braiding pitch are controlled so that the braiding density of the shielding layer 4 is not less than 85% and the braiding angle is controlled within the range of 59°, thereby obtaining the shielding layer 4; Step 6: Preparation of composite sheath layer 5: A microporous polytetrafluoroethylene tape with a thickness range of 0.06 mm and a width range of 15 mm is used, and is wrapped tightly around the outside of the shielding layer 4 with an overlap rate of 30%, and the wrapping direction is the Z direction, to form an inner sheath layer 51; Then, a microporous polytetrafluoroethylene tape with a thickness range of 0.06 mm and a width range of 15 mm is used, and wrapped with an overlap rate of 30% and an S-direction to form an outer sheath layer 52; Then, a sintering process is used to tightly fuse the inner sheath layer 51 and the outer sheath layer 52 together, and the wrapping overlap rate of the microporous polytetrafluoroethylene tape is controlled within a range of 50%, and the sintering temperature range is 450° C., to form a composite sheath layer 5; and the finished cable is manufactured.

[0033] Example 3 The other contents of this embodiment are the same as those of Embodiment 1, except that: Step 1: Preparation of stranded nickel-plated conductor 1: 19 nickel-plated copper alloy or copper round wires with a nickel-plated layer content of not less than 27% are used, and are twisted in the same direction according to a pitch ratio of 16 and an arrangement of 1+6+12, and the twisting direction is S direction, to obtain a twisted nickel-plated conductor 1; Step 2, preparation of a refractory layer 2 of the insulating core: High-purity quartz fiber with a linear density range of 600D is used to tightly wrap the outside of the twisted nickel-plated conductor 1 by a bundle winding process; the bundle winding density is ensured by controlling the bundle winding pitch, the number of bundle windings and selecting quartz fibers with different linear densities, so that the bundled quartz fiber layer is tightly attached to the twisted nickel-plated conductor 1, and the bundle direction is the Z direction; After the quartz fiber is bundled, a silicone rubber emulsion is applied and vulcanized. Through the coating and drying process, the gaps in the bundled quartz fiber are filled, and the speed of applying the silicone rubber emulsion is controlled, the thickness of the silicone rubber emulsion coating layer is adjusted to be 50um, and the drying time, and the quartz fiber bundled on the outside of the twisted nickel-plated conductor 1 is made into a refractory layer 2; Step 3, preparation of the composite insulation layer 3 of the insulating core: a polyimide tape with a thickness range of 0.03mm and a width range of 20mm is used, and then an overlapping wrapping process is adopted, the wrapping direction is S direction, and it is tightly wrapped on the outside of the refractory layer 2, and the overlap rate is 50%, to form an inner insulation layer 31; then a microporous polytetrafluoroethylene tape with a thickness range of 0.07mm and a width range of 25mm is used, and then a wrapping process is adopted, and then an overlapping wrapping process is adopted, the wrapping direction is Z direction, and it is tightly wrapped on the outside of the inner insulation layer 31 to form an outer insulation layer 32; Then, a sintering process is adopted to fuse the polyimide tape and the microporous polytetrafluoroethylene tape tightly together through the sealing of the microporous polytetrafluoroethylene tape, and the composite insulating layer 3 is manufactured by controlling the wrapping overlap rate of the microporous polytetrafluoroethylene tape within a range of 80% and the sintering temperature within a range of 500° C.; Step 4: Preparation of cable core: Two insulated wire cores are twisted together to form a cable core, the twisting pitch ratio of the cable core is 16, and the twisting direction is S direction; Step 5: Preparation of shielding layer 4: A plurality of nickel-plated round copper wires having a nickel-plated content of not less than 27% are combined into strands, and then the combined strands of nickel-plated round copper wires are tightly wrapped on the outside of the cable core by a braiding process, and the number of combined nickel-plated round copper wires, the number of braiding spindles and the braiding pitch are controlled so that the braiding density of the shielding layer 4 is not less than 85% and the braiding angle is controlled within the range of 72°, thereby obtaining the shielding layer 4; Step 6: Preparation of composite sheath layer 5: A microporous polytetrafluoroethylene tape with a thickness range of 0.07 mm and a width range of 25 mm is used, and is wrapped tightly around the outside of the shielding layer 4 with an overlap rate of 50%, and the wrapping direction is the Z direction, to form an inner sheath layer 51; Then, a microporous polytetrafluoroethylene tape with a thickness range of 0.07 mm and a width range of 25 mm is used, and wrapped with an overlap rate of 50% and an S-direction to form an outer sheath layer 52; Then, a sintering process is used to tightly fuse the inner sheath layer 51 and the outer sheath layer 52 together, and the wrapping overlap rate of the microporous polytetrafluoroethylene tape is controlled to be in the range of 80%, and the sintering temperature range is 500° C., to form a composite sheath layer 5; and the finished cable is manufactured.

[0034] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A light aviation fire-resistant cable, characterized in that: It includes a cable core and a shielding layer and a composite sheath layer sequentially coated on the outside of the cable core from the inside to the outside; The cable core comprises an insulating core; the insulating core comprises a twisted nickel-plated conductor and a fire-resistant layer and a composite insulating layer sequentially coated on the outside of the twisted nickel-plated conductor from the inside to the outside; The fire-resistant layer comprises quartz fibers, the quartz fiber bundles are wound around the twisted nickel-plated conductors, and the quartz fibers are coated with silicone rubber emulsion and then vulcanized at high temperature to form the fire-resistant layer; the fire-resistant layer is wrapped around the composite insulating layer; The shielding layer is a nickel-plated round copper wire braided layer; a composite sheath layer is arranged outside the shielding layer.

2. The light aviation fire-resistant cable according to claim 1, characterized in that: The composite insulation layer comprises an inner insulation layer wrapped around the fire-resistant layer and an outer insulation layer wrapped around the inner insulation layer; the inner insulation layer is a polyimide tape wrapping layer, and the outer insulation layer is a microporous polytetrafluoroethylene tape wrapping layer. The inner insulation layer and the outer insulation layer are sintered at high temperature to form a composite insulation layer.

3. The light aviation fire-resistant cable according to claim 1, characterized in that: The composite sheath layer comprises an inner sheath layer and an outer sheath layer; the inner sheath layer is formed by wrapping a microporous polytetrafluoroethylene tape around the shielded cable, and the outer sheath layer is formed by reversely wrapping microporous polytetrafluoroethylene around the inner sheath layer; the inner sheath layer and the outer sheath layer are sintered at high temperature to form a composite sheath layer.

4. The light aviation fire-resistant cable according to claim 1, characterized in that: The twisted nickel-plated conductor is formed by twisting a plurality of nickel-plated round copper wires or nickel-plated copper alloys, and the nickel content of the nickel-plated layer of the nickel-plated round copper wires or nickel-plated copper alloys is not less than 27%.

5. The light aviation fire-resistant cable according to claim 4, characterized in that: The stranded nickel-plated conductor is stranded in the same direction in a 1+6+12 arrangement, the stranding pitch ratio is 8-16, and the stranding direction is S.

6. The light aviation fire-resistant cable according to claim 1, characterized in that: The nickel content of the nickel-plated layer of the nickel-plated round copper wire used for weaving the shielding layer is not less than 27%, and the weaving density is not less than 85%.

7. The light aviation fire-resistant cable according to claim 1, characterized in that: The cable core is formed by twisting two insulated wire cores, the twisting direction is S direction, and the twisting pitch ratio is 8-16.

8. The light aviation fire-resistant cable according to claim 1, characterized in that: The quartz fiber It is a high-purity quartz fiber with a linear density ranging from 200D to 600D.

9. The method for preparing a light aviation fire-resistant cable according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Preparation of stranded nickel-plated conductor: 19 nickel-plated copper alloy or copper round wires with a nickel-plated layer content of not less than 27% are used, and are twisted in the same direction according to a pitch ratio of 8 to 16 and an arrangement of 1+6+12, and the twisting direction is S direction to obtain a twisted nickel-plated conductor; Step 2, preparation of a refractory layer of the insulating core: High-purity quartz fiber with a linear density range of 200D to 600D is tightly wrapped around the outside of the stranded nickel-plated conductor using a bundle winding process; the bundle winding density is ensured by controlling the bundle winding pitch, the number of bundle windings and selecting quartz fibers with different linear densities, so that the bundled quartz fiber layer is tightly attached to the stranded nickel-plated conductor, and the bundle direction is the Z direction; After the quartz fiber is bundled, a process method of coating with silicone rubber emulsion and vulcanizing is adopted. Through the coating and drying process, the gaps in the bundled quartz fiber are filled, and the speed of coating with silicone rubber emulsion is controlled, and the thickness of the silicone rubber emulsion coating layer is adjusted, which ranges from 10um to 50um, and the drying time, and the quartz fiber bundled outside the twisted nickel-plated conductor is made into a fire-resistant layer; Step 3, preparation of the composite insulation layer of the insulated wire core: using a thickness range of 0.02mm to 0.03mm and a width range of 5mm A polyimide tape with a width of ~20mm is then wrapped in an overlapping wrapping process in the S direction, tightly wrapped on the outside of the fire-resistant layer, with an overlapping rate of 10% to 50%, to form an inner insulating layer; a microporous polytetrafluoroethylene tape with a thickness range of 0.05mm to 0.07mm and a width range of 5mm to 25mm is then used, and then wrapped in an overlapping wrapping process in the Z direction, tightly wrapped on the outside of the inner insulating layer to form an outer insulating layer; Then, a sintering process is adopted to fuse the polyimide tape and the microporous polytetrafluoroethylene tape tightly together through the sealing of the microporous polytetrafluoroethylene tape, and a composite insulating layer is made by controlling the wrapping overlap rate of the microporous polytetrafluoroethylene tape within a range of 20% to 80% and the sintering temperature within a range of 400°C to 500°C. Step 4: Preparation of cable core: Two insulated wire cores are twisted together to form a cable core, the twisting pitch ratio of the cable core is 8-16, and the twisting direction is S direction; Step 5: Preparation of shielding layer: A plurality of nickel-plated round copper wires with a nickel-plated content of not less than 27% are combined into strands, and then the combined strands of nickel-plated round copper wires are tightly wrapped on the outside of the cable core by a braiding process, and the braiding density of the shielding layer is controlled to be not less than 85% and the braiding angle is controlled within the range of 46° to 72° by controlling the number of combined nickel-plated round copper wires, the number of braiding spindles and the braiding pitch, so as to obtain a shielding layer; Step 6: Preparation of composite sheath layer: Use microporous polytetrafluoroethylene tape with a thickness range of 0.05mm to 0.07mm and a width range of 5mm to 25mm, wrap it tightly on the outside of the shielding layer with an overlap rate of 10% to 50%, and wrap it in the Z direction to form an inner sheath layer; Then, a microporous polytetrafluoroethylene tape with a thickness ranging from 0.05 mm to 0.07 mm and a width ranging from 5 mm to 25 mm is used, and an overlap rate of 10% to 50% is used for wrapping, and the wrapping direction is S direction to form an outer sheath layer; Then, a sintering process is used to tightly fuse the inner sheath layer and the outer sheath layer together, and the wrapping overlap rate of the microporous polytetrafluoroethylene tape is controlled to be in the range of 20% to 80%, and the sintering temperature range is 400°C to 500°C, so as to form a composite sheath layer; Finished cable manufacturing is completed.

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