A bending-resistant cable and its combined components

Abstract

The present invention discloses a bend-resistant cable and its components, comprising a core, an insulation layer covering the core, a shielding layer covering the insulation layer, and a sheath covering the shielding layer. The core comprises a center conductor, a first twisted layer, and a second twisted layer. The center conductor, the first twisted layer, and the second twisted layer are all twisted together by a plurality of conductors. The twist pitch of the first twisted layer is 10-14 mm, and the twist pitch of the second twisted layer is 12-16 mm. The conductors are twisted together by bare copper wire and copper foil wire, and the twist pitch of the bare copper wire and the copper foil wire is no more than 20 mm. Adjacent conductors are twisted in opposite directions. The ratio of the twist pitch of the first twisted layer to the diameter of the first twisted layer is 14, and the ratio of the twist pitch of the second twisted layer to the diameter of the second twisted layer is 16. The cable disclosed by the present invention improves the torsion resistance and flexibility of the conductor, enhances the overload resistance and flame retardancy of the insulation, and also improves the shielding efficiency of the shielding layer and the torsion resistance of the cable as a whole.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, in particular to a bending-resistant cable and its combined components. Background Art

[0002] A flying car is a machine that can transform from a road car into an aircraft while flying in the air or driving on land.

[0003] The United States began developing flying cars in the 1940s. In 2010, the US aviation authorities approved the commercial production of Terrafugia's amphibious transformable vehicle for land and air. In 2018, the Dutch company PAL-V launched a mass-produced flying car, which was launched in 2019. Currently, domestic research on flying cars has entered the demonstration operation stage.

[0004] As the power transmission circuit for the entire vehicle, the wing cables of flying cars are crucial for their safety and performance. Safety is paramount. Because the wing cables must follow the wings' extension and retraction, frequently twisting and bending vertically, their conductors must be break-resistant. However, existing cables lack the strength to meet this requirement, necessitating the development of a new, bend-resistant cable. Summary of the Invention

[0005] The present invention provides a bending-resistant cable and its combined components, so as to solve the technical problem of cable breakage caused by bending in the prior art.

[0006] In order to solve the above technical problems or partially solve the above technical problems, the present invention proposes the following optimization technical solutions:

[0007] A bending-resistant cable comprises a core, an insulation layer covering the core, a shielding layer covering the insulation layer, and a sheath covering the shielding layer, the insulation layer comprising an inner insulation layer and an outer insulation layer formed by co-extrusion, the sheath comprising an inner sheath and an outer sheath, the core comprising a center conductor, a first twisted layer, and a second twisted layer, the center conductor, the first twisted layer, and the second twisted layer being all formed by twisting multiple conductors, the twisting pitch of the first twisted layer being 10-14 mm, the twisting pitch of the second twisted layer being 12-16 mm, the conductor being formed by twisting bare copper wire and copper foil wire, the twisting pitch of the bare copper wire and copper foil wire being no greater than 20 mm, the twisting directions of two adjacent conductors being opposite, the ratio of the twisting pitch of the first twisted layer to the diameter of the first twisted layer being 14, and the ratio of the twisting pitch of the second twisted layer to the diameter of the second twisted layer being 16.

[0008] Furthermore, the conductor is formed by twisting a plurality of bare copper wires or a plurality of copper foil wires.

[0009] Furthermore, the cross-sectional area of ​​the core is 16 mm 2 , 25mm 2 , 35mm 2 or 50mm 2 .

[0010] Furthermore, the thickness of the inner insulation layer and the outer insulation layer are both 0.35 mm, 0.4 mm or 0.45 mm, the outer insulation layer covers the inner insulation layer, and the inner insulation layer covers the wire core.

[0011] Furthermore, the shielding layer includes an inner shielding layer and an outer shielding layer, the outer shielding layer covers the inner shielding layer, the inner shielding layer covers the outer insulation layer, the inner shielding layer is cross-woven by tinned copper wire and bulletproof wire, and the outer shielding layer is shielded by wrapped aluminum-plastic composite tape.

[0012] Furthermore, the braiding pitch of the tinned copper wire and the bulletproof wire is 23 mm, 43 mm, 36 mm or 29 mm, and the braiding density is 85%.

[0013] Furthermore, the thickness of the outer shielding layer is 0.04 mm.

[0014] Furthermore, the outer sheath covers the inner sheath, the inner sheath covers the outer shielding layer, and the thickness of the inner sheath and the outer sheath are both 0.35 mm or 0.4 mm.

[0015] The present invention provides another technical solution: a composite component of a bending-resistant cable, comprising the cable, wherein the components of the inner insulating layer and the inner sheath are the same, both comprising: 45-75wt% of methyl vinyl silicone rubber, 20-45wt% of silicon dioxide, 10-35wt% of nano-grade activated clay, 3-10wt% of hydroxysiloxane, 5-10wt% of composite high-efficiency flame retardant, 0.5-3wt% of hydrogensiloxane, and 0.5-2wt% of platinum vulcanizing agent.

[0016] Furthermore, the outer insulating layer and the outer sheath have the same composition, both including: methyl vinyl silicone rubber 25-55wt%, silicon dioxide 20-30wt%, porcelain powder 20-40wt%, zinc oxide 1-5wt%, iron oxide 1-5wt%, zinc stearate 0.1-1wt%, hydroxysiloxane 2-8wt%, hydrogensiloxane 0.5-3wt%, and platinum vulcanizer 0.3-1.5wt%.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The cable of the present invention is installed in the wing of a flying car. Based on the stress to be borne by the cable during wing torsion, the conductor is constructed from a twisted combination of bare copper wire and copper foil. The addition of copper foil increases the conductor's strength, preventing breakage during wing torsion. The twisting pitch of the bare copper wire and copper foil is limited to 20 mm, preventing the conductor from being too weak. The twisting pitch of the first twisted layer is limited to 10-14 mm, and the twisting pitch of the second twisted layer is limited to 12-16 mm. This prevents excessive pitch from increasing the cable's bending radius, which would otherwise result in excessive stress during vertical torsion. Adjacent conductors are twisted in opposite directions, ensuring the sum of the torsional moments of each layer is zero, thereby ensuring the conductor's flexibility and roundness. The ratio of the twisting pitch of the first twisted layer to its diameter is 14, and the ratio of the twisting pitch of the second twisted layer to its diameter is 16. These ratios ensure that the cable's radius does not increase during bending and that the stress on the cable is not excessive. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the cable of the present invention.

[0020] Figure 2 It is a schematic structural diagram of the cable of the present invention without the second twisted layer.

[0021] 1-conductor, 11-center conductor, 12-first twisted layer, 13-second twisted layer, 2-core, 3-inner insulation layer, 4-outer insulation layer, 5-inner shielding layer, 51-tinned copper wire, 52-bulletproof wire, 6-outer shielding layer, 7-inner sheath, 8-outer sheath. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] Example 1

[0024] See also Figure 1-2A bending-resistant cable includes a core 2, an insulation layer covering the core 2, a shielding layer covering the insulation layer, and a sheath covering the shielding layer. The insulation layer includes an inner insulation layer 3 and an outer insulation layer 4 formed by co-extrusion. The sheath includes an inner sheath 7 and an outer sheath 8. The core 2 includes a center conductor 11, a first twisted layer 12, and a second twisted layer 13. The center conductor 11, the first twisted layer 12, and the second twisted layer 13 are all twisted together by multiple conductors 1. The twist pitch of the first twisted layer 12 is 10-14 mm, and the twist pitch of the second twisted layer 13 is 12-16 mm. This prevents the pitch from being too large, which would increase the bending radius of the cable. Too small a diameter will result in excessive stress when the cable is twisted vertically. Conductor 1 is composed of bare copper wire and copper foil twisted together. Based on the stress the cable will experience when the flying car's wing is twisted, multiple copper foil wires are added to conductor 1, which is the primary force bearing during wing twisting. This increases conductor 1's strength and prevents breakage during wing twisting. The twisting pitch of the bare copper wire and copper foil is no greater than 20 mm, ensuring the conductor has sufficient strength to withstand the stress generated by the twisting of the flying car's wing. Adjacent conductors 1 are twisted in opposite directions, ensuring the sum of the torsional torques of each layer is zero, ensuring the flexibility and roundness of conductor 1. The ratio of the twist pitch of the first twisted layer 12 to its diameter is 14, and the ratio of the twist pitch of the second twisted layer 13 to its diameter is 16. These ratios ensure that the cable's radius does not increase when bent, while still being able to withstand the stress of bending.

[0025] In the above technical solution, the second twisted layer 13 is not necessarily present, that is, the core 2 can be provided with only the central conductor 11 and the first twisted layer 12 (see Figure 2 ), a central conductor 11, a first twisted layer 12 and a second twisted layer 13 may also be provided (see Figure 1 ).

[0026] Conductor 1 also includes a plurality of bare copper wires twisted together or a plurality of copper foil wires twisted together. When the flying car wing twists, the stress on different parts of the core 2 varies. The copper foil wire has the function of increasing strength. The amount of copper foil wire added to the conductor is determined according to the stress. More copper foil wires are added to the conductor at locations subject to greater stress, or all copper foil wires are used to twist the conductor. Specifically, the conductor is formed by twisting bare copper wire and multiple copper foil wires, or a conductor is formed by twisting multiple copper foil wires. In locations subject to less stress, fewer copper foil wires are added to the conductor, or all bare copper wires are twisted together. Specifically, the conductor is formed by twisting multiple bare copper wires, or a conductor is formed by twisting bare copper wire and a few copper foil wires. A cable twisted in this manner can withstand the stress of wing twisting. At the same time, the DC resistance of the copper foil wire is much greater than that of bare copper wire of the same specification, which can balance the contradiction between the conductor's tensile strength and DC resistance.

[0027] The cross-sectional area of ​​core 2 is 16 mm 2 , 25mm 2 , 35mm 2 or 50mm 2 When the cross section of core 2 is 16mm 2 or 25mm 2 When the core 2 is provided with only the center conductor 11 and the first twisted layer 12, when the cross section of the core 2 is 35mm 2 or 50mm 2 The core 2 is provided with a central conductor 11, a first twisted layer 12 and a second twisted layer 13.

[0028] The thickness of the inner insulation layer 3 and the outer insulation layer 4 are both 0.35mm, 0.4mm or 0.45mm. The outer insulation layer 4 covers the inner insulation layer 3, and the inner insulation layer 3 covers the core 2. The cross section is 16mm 2 The conductor 1 is covered with an inner insulating layer 3 and an outer insulating layer 4 with a thickness of 0.35 mm and a cross section of 25 mm 2 and 35mm 2 The conductor is covered with an inner and outer insulation layer of 0.4mm thickness and a cross section of 50mm 2 The conductor is covered with an inner insulation layer and an outer insulation layer with a thickness of 0.45 mm.

[0029] The shielding layer consists of an inner shielding layer 5 and an outer shielding layer 6. The outer shielding layer 6 covers the inner shielding layer 5, which in turn covers the outer insulating layer 4. The inner shielding layer 5 is made of a cross-woven braid of tinned copper wire 51 and bulletproof wire 52, while the outer shielding layer 6 is wrapped with aluminum-plastic composite tape. The twisting of the wings in flight can subject the cable's braided shield to severe mechanical stress, which can cause the braided copper wire to break, resulting in EMI shielding failure. A braided shield made solely of tinned copper wire cannot withstand excessive tension. To prevent deformation or breakage, bulletproof wire 52 is added as a reinforcement to provide high tensile strength.

[0030] The braiding pitch of the tinned copper wire 51 and the bulletproof wire 52 is 23mm, 43mm, 36mm or 29mm, and the braiding density is 85%, wherein the cross section is 16mm 2 The inner shield 5 of the conductor 1 consists of 7 tinned copper wires and 1 bulletproof wire, with a braiding pitch of 23mm and a cross section of 25mm 2 The inner shield 5 of the conductor 1 consists of 10 tinned copper wires and 1 bulletproof wire, with a braiding pitch of 43mm and a cross section of 35mm 2 The inner shield 5 of the conductor 1 consists of 10 tinned copper wires and 1 bulletproof wire, with a braiding pitch of 36 mm and a cross section of 50 mm. 2The inner shielding layer 5 of the conductor 1 includes 10 tinned copper wires and 1 bulletproof wire, and the braiding pitch is 29 mm.

[0031] The thickness of the outer shielding layer 6 is 0.04 mm. The outer shielding layer is used to shield electromagnetic interference and prevent electromagnetic interference caused by the breakage of the inner shielding layer. The thickness of the outer shielding layer is set to 0.04 mm, which is the minimum radius under the premise of ensuring the shielding effect.

[0032] The outer sheath 8 covers the inner sheath 7, and the inner sheath 7 covers the outer shielding layer 6. The thickness of the inner sheath 7 and the outer sheath 8 are both 0.35mm or 0.4mm, wherein the cross section is 16mm 2 The inner sheath 7 and outer sheath 8 of the conductor 1 are both 0.35 mm and the cross section is 25 mm 2 , 35mm 2 , 50mm 2 The inner sheath 7 and the outer sheath 8 of the conductor 1 are both 0.4 mm.

[0033] Example 2

[0034] The present invention also discloses a flex-resistant cable assembly, comprising a cable. The inner insulation layer and the inner sheath have the same composition, including: 45-75 wt% methyl vinyl silicone rubber, 20-45 wt% silica, 10-35 wt% nano-activated clay, 3-10 wt% hydroxy siloxane, 5-10 wt% composite high-efficiency flame retardant, 0.5-3 wt% hydrogen siloxane, and 0.5-2 wt% platinum vulcanizer. In one embodiment of the present application, the molecular weight of the methyl vinyl silicone rubber is 350,000-480,000. In another embodiment of the present application, the molecular weight of the methyl vinyl silicone rubber is 380,000-420,000. In another embodiment of the present application, the molecular weight of the methyl vinyl silicone rubber is 400,000. A molecular weight of 350,000-480,000 effectively ensures the strength of the rubber compound. In the tensile flame-retardant silicone rubber composition, the mass percentage of the methyl vinyl silicone rubber is greater than or equal to 50% to ensure insulation resistance. The composite high-efficiency flame retardant is made of a material with an oxygen index ≥ 38. The use of composite high-efficiency flame retardants makes the material oxygen index reach above 38, which has a good flame retardant effect.

[0035] Nano-scale activated clay treatment enhances dispersion and bonding with silica gel, effectively increasing the strength of the tensile flame-retardant silicone rubber composition. Silicon dioxide, a reinforcing filler, enhances the tensile tear strength of the tensile flame-retardant silicone rubber composition. The use of a composite high-efficiency flame retardant enhances flame retardancy.

[0036] The preferred content of methyl vinyl silicone rubber is 50 to 70 parts.

[0037] Table 1 is a comparison of the examples and comparative examples of the inner insulation layer or inner sheath component formula

[0038] formula Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Methyl vinyl silicone rubber 55 60 70 55 30 55 55 Silicon dioxide 25 30 35 25 25 25 42 Nano-level activated clay 15 25 30 15 15 / 15 Hydroxysiloxane 3 5 7 3 3 3 3 Composite high-efficiency flame retardant 5 8 10 5 5 5 5 Hydrogen siloxane 0.5 1 2 0.5 0.5 0.5 0.5 Platinum vulcanizing agent 0.5 1 1.2 0.5 0.5 0.5 0.5

[0039] The outer side of the inner insulating layer is covered with an outer insulating layer, and the outer side of the inner sheath is covered with an outer sheath. The outer insulating layer and the outer sheath have the same composition, including: 25-55wt% of methyl vinyl silicone rubber, 20-30wt% of silicon dioxide, 20-40wt% of porcelain powder, 1-5wt% of zinc oxide, 1-5wt% of iron oxide, 0.1-1wt% of zinc stearate, 2-8wt% of hydroxysiloxane, 0.5-3wt% of hydrogensiloxane, and 0.3-1.5wt% of platinum vulcanizer.

[0040] The high-temperature porcelain-forming silicone rubber composition adopts methyl vinyl silicone rubber to make it have good softness. In one embodiment of the present application, the methyl vinyl silicone rubber is polymethyl vinyl siloxane produced by the meteorological method. In one embodiment of the present application, the molecular weight of the methyl vinyl silicone rubber is 350,000-480,000. In another embodiment of the present application, the molecular weight of the methyl vinyl silicone rubber is 380,000-420,000. In another embodiment of the present application, the molecular weight of the methyl vinyl silicone rubber is 400,000. The molecular weight of methyl vinyl silicone rubber is 350,000-480,000, which can effectively ensure the strength of the rubber compound. In one embodiment of the present application, in the high-temperature porcelain-forming silicone rubber composition, the mass percentage of the methyl vinyl silicone rubber is less than or equal to 50%, which can effectively ensure the porcelain-forming effect.

[0041] In the high-temperature porcelain-forming silicone rubber composition, silicon dioxide is used as a reinforcing filler to enhance the tensile and tearing strength of the high-temperature porcelain-forming silicone rubber composition.

[0042] Table 2 is a comparison of the embodiment and comparative example of the outer insulation layer or outer sheath component formula

[0043] formula Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Methyl vinyl silicone rubber 35 45 50 35 65 35 Silicon dioxide 25 24 23 25 25 25 Porcelain powder 2 1.5 3 2 2 / zinc oxide 2 1.5 2 2 2 / Iron oxide 2.5 21 20 25 25 25 Zinc stearate 0.5 0.8 0.2 0.5 0.5 0.5 Hydroxysiloxane 3 2.5 5 3 3 3 Hydrogen siloxane 1 2 3 1 1 1 Platinum vulcanizing agent 0.8 1 1.5 0.8 0.8 0.8

[0044] The two examples 1 in Table 1 and Table 2 were combined to form cable 1, the two examples 2 in Table 1 and Table 2 were combined to form cable 2, and the two examples 3 in Table 1 and Table 2 were combined to form cable 3. Softness tests, tensile tests, fire resistance tests, and insulation tests were performed on cables 1, 2, and 3, and the following conclusions were drawn:

[0045] Group Elasticity module (MPa) Tensile strength (MPa) Is short circuit Whether it meets the insulation boiling requirements Is the wire sheath worn through? Example 1 3.7 11.5 no yes no Example 2 3.6 11.4 no yes no Example 3 3.7 11.4 no yes no Comparative Example 1 3.1 11.2 no yes no Comparative Example 2 3.2 11.3 no yes no Comparative Example 3 3.4 9.1 no yes no Comparative Example 4 3.6 11.3 no yes no

[0046] From the above, it can be seen that the cables 1, 2 and 3 of the present application have better softness and higher tensile strength than the ordinary cables of the comparative example. At the same time, the flame-retardant B1-level flexible control cable of the present application not only has good softness and good tensile strength, but also has good fire resistance and excellent insulation, water resistance and moisture resistance, so that the high-temperature porcelain-forming silicone rubber composition of the present application can be used to prepare cables with good tensile strength and good softness, and has the advantages of good temperature resistance, B1-level flame retardancy and fire resistance. The high-temperature porcelain-forming silicone rubber composition of the present application can be used to prepare cables with good tensile strength and good softness, and has the advantages of good temperature resistance, B1-level flame retardancy and fire resistance.

[0047] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A bending-resistant cable comprising a core, an insulation layer covering the core, a shielding layer covering the insulation layer, and a sheath covering the shielding layer, wherein the insulation layer comprises an inner insulation layer and an outer insulation layer formed by co-extrusion, and the sheath comprises an inner sheath and an outer sheath, characterized in that: The wire core includes a central conductor, a first twisted layer and a second twisted layer. The central conductor, the first twisted layer and the second twisted layer are all twisted together by multiple conductors. The twisting pitch of the first twisted layer is 10-14 mm, and the twisting pitch of the second twisted layer is 12-16 mm. The conductor is twisted together by bare copper wire and copper foil wire. The pitch of the bare copper wire and copper foil wire is not greater than 20 mm. The twisting directions of two adjacent conductors are opposite. The ratio of the twisting pitch of the first twisted layer to the diameter of the first twisted layer is 14, and the ratio of the twisting pitch of the second twisted layer to the diameter of the second twisted layer is 16.

2. A bending-resistant cable according to claim 1, characterized in that: The conductor is also formed by twisting a plurality of bare copper wires or a plurality of copper foil wires.

3. The bending-resistant cable according to claim 1, characterized in that: The cross-sectional area of ​​the core is 16 mm 2 , 25mm 2 , 35mm 2 or 50mm 2 .

4. The bending-resistant cable according to claim 1, characterized in that: The thickness of the inner insulating layer is 0.35 mm, 0.4 mm or 0.45 mm; The thickness of the outer insulating layer is 0.35 mm, 0.4 mm or 0.45 mm; The outer insulating layer covers the inner insulating layer, and the inner insulating layer covers the wire core.

5. The bending-resistant cable according to claim 1, characterized in that: The shielding layer includes an inner shielding layer and an outer shielding layer, the outer shielding layer covers the inner shielding layer, the inner shielding layer covers the outer insulating layer, the inner shielding layer is cross-woven by tinned copper wire and bulletproof wire, and the outer shielding layer is shielded by aluminum-plastic composite tape.

6. The bending-resistant cable according to claim 5, characterized in that: The braiding pitch of the tinned copper wire is 23mm, 43mm, 36mm or 29mm; The braiding pitch of the bulletproof wire is 23mm, 43mm, 36mm or 29mm; The weave density is 85%.

7. The bending-resistant cable according to claim 5, characterized in that: The thickness of the outer shielding layer is 0.04 mm.

8. The bending-resistant cable according to claim 5, characterized in that: The outer sheath covers the inner sheath, and the inner sheath covers the outer shielding layer. The thickness of the inner sheath and the outer sheath are both 0.35 mm or 0.4 mm.

9. A combination of components of a bending-resistant cable, characterized in that: Comprising the cable according to any one of claims 1 to 8, the components of the inner insulation layer and the inner sheath are the same, both comprising: 45-75wt% of methyl vinyl silicone rubber, 20-45wt% of silicon dioxide, 10-35wt% of nano-activated clay, 3-10wt% of hydroxysiloxane, 5-10wt% of composite high-efficiency flame retardant, 0.5-3wt% of hydrogensiloxane, and 0.5-2wt% of platinum vulcanizing agent.

10. A combination of bending-resistant cables according to claim 9, characterized in that: The outer insulating layer and the outer sheath have the same composition, both including: 25-55wt% of methyl vinyl silicone rubber, 20-30wt% of silicon dioxide, 20-40wt% of porcelain powder, 1-5wt% of zinc oxide, 1-5wt% of iron oxide, 0.1-1wt% of zinc stearate, 2-8wt% of hydroxysiloxane, 0.5-3wt% of hydrogensiloxane, and 0.3-1.5wt% of platinum vulcanizer.

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