Self-repairing aviation cable bundle and preparation method and application thereof

Abstract

This invention discloses a self-healing aviation cable bundle, its preparation method, and its application, belonging to the technical field of aviation electrical circuit systems. The self-healing aviation cable bundle, from the inside out, comprises multiple conductors, a self-healing insulation layer, a self-healing gel filler, and a self-healing sheath layer. The self-healing insulation layer covers each conductor, the self-healing gel filler fills the space between the conductor and the self-healing sheath layer, and the self-healing sheath layer is woven or extruded over the self-healing gel filler. The self-healing insulation layer, self-healing sheath layer, and self-healing gel filler achieve self-healing functionality based on dynamic reversible chemical bonds or microencapsulation technology. When the cable bundle is damaged, by applying external stimuli such as heat, light of a specific wavelength, or microwaves, the damaged area can automatically repair the damage, restoring electrical insulation and mechanical protection performance. This invention significantly improves the reliability and lifespan of aircraft cable bundles, reduces maintenance costs and safety hazards, and is applicable to aviation electrical circuit systems.

Description

Technical Field

[0001] This invention relates to the field of aviation electrical circuit system technology, specifically to a self-healing aviation cable bundle, its preparation method, and its application. Background Technology

[0002] Aviation cable bundles are the "nervous system" of an aircraft, responsible for transmitting power and signals, and their reliability is directly related to flight safety. During aircraft service, cable bundles are subjected to harsh environments such as vibration, high and low temperature cycles, humidity and heat, chemical corrosion, and complex electromagnetic interference, making them highly susceptible to damage to the insulation or sheath layers due to mechanical wear and insulation aging. Such damage can cause serious malfunctions such as short circuits, arcing, and signal transmission interruptions, posing a significant threat to aviation safety.

[0003] Currently, the maintenance of aviation cables mainly relies on periodic manual inspections and replacement after a failure. This maintenance model has obvious drawbacks: on the one hand, periodic inspections require a lot of manpower, material resources, and time, and the maintenance cycle is long, which seriously affects the aircraft's availability; on the other hand, for sudden cable damage, periodic inspections cannot predict and deal with it in advance, and remedial measures can often only be taken after the failure occurs, by which time irreversible losses may have already been caused.

[0004] Furthermore, existing aviation cables primarily use traditional polymer materials for their insulation and sheathing layers, such as polyimide and ETFE (ethylene-tetrafluoroethylene copolymer). While these traditional materials possess certain insulation properties and mechanical strength, they cannot restore their function on their own once damaged, requiring manual intervention for repair or replacement, further increasing the total lifecycle cost of aviation operations.

[0005] Therefore, existing technologies need to be improved. Summary of the Invention

[0006] The core objective of this invention is to provide a self-healing aviation cable bundle that can automatically repair itself under external stimuli when the insulation layer, sheath layer, or filling part is damaged, quickly restoring its insulation performance and mechanical integrity, thereby solving the problems of traditional aviation cables being easily damaged, difficult to repair, and having high maintenance costs.

[0007] This invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides a self-healing aviation cable bundle, comprising conductors, a self-healing insulating layer covering the exterior of a single conductor, and a self-healing sheath covering the exterior of multiple conductors. The self-healing sheath is filled with a self-healing gel filler. The self-healing insulating layer, the self-healing sheath, and the self-healing gel filler automatically repair damage under external stimuli, such as heat, light, or microwaves.

[0009] Furthermore, in this invention, the self-healing insulating layer and the self-healing sheath layer described above are configured as polymer materials based on dynamic reversible covalent bonds.

[0010] Furthermore, in this invention, the dynamic reversible covalent bonds of the polymer material described above are configured as Diels-Alder bonds, disulfide bonds, or oxime ester bonds.

[0011] Furthermore, in this invention, the self-healing insulating layer and the self-healing sheath layer described above are configured as polymer materials containing a microcapsule system; the microcapsule system includes microcapsules containing repair monomers and a catalyst dispersed in the repair monomers. When the material is damaged, the microcapsules rupture to release the repair monomers, which then polymerize and repair under the action of the catalyst.

[0012] Furthermore, in this invention, the microcapsules described above are uniformly distributed around the center of the self-healing sheath layer.

[0013] Furthermore, in this invention, the self-healing gel filler described above is configured as a supramolecular gel based on dynamic reversible non-covalent bonds or dynamic reversible covalent bonds. The dynamic reversible non-covalent bonds include hydrogen bonds, ionic bonds, and metal coordination bonds, which can achieve self-repair through the recombination of molecular chains after damage.

[0014] Furthermore, in this invention, the aforementioned plurality of conductors are arranged in a regular polygonal shape on the cross-section.

[0015] Secondly, the present invention also provides a method for preparing the self-healing aviation cable bundle, comprising:

[0016] S1 Preparation of self-healing materials: Self-healing materials are synthesized or mixed separately for forming self-healing insulating layers, self-healing gel fillers and self-healing sheath layers;

[0017] S2 Wire Insulation: The self-healing insulation material prepared in step S1 is coated onto a single wire through an extrusion process to form a wire with a self-healing insulation layer;

[0018] S3 Wire Harness Stranding: Strand multiple wires with self-healing insulation layers obtained in step S2 together to form a cable bundle core;

[0019] S4 Filling Gel: Inject or press the self-healing gel material prepared in step S1 into the gaps of the stranded cable bundle core;

[0020] S5 Wrapping Sheath: The self-healing sheath material prepared in step S1 is applied to the outside of the cable bundle core filled with self-healing gel filler through braiding, wrapping or extrusion processes to finally form a self-healing aviation cable bundle.

[0021] Furthermore, in this invention, in step S1 above, the self-healing sheath material is a composite yarn containing shape memory alloy wires or high-strength aramid fibers, which is woven together with the self-healing polymer matrix to form a sheath layer that has both self-healing and mechanical reinforcement properties.

[0022] Thirdly, the present invention also provides an application of the self-healing aviation cable bundle described above, in which the self-healing aviation cable bundle is applied in an aircraft.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1. Proactive safety: It transforms passive maintenance into proactive defense, enabling automatic repair in the early stages of damage and preventing the escalation of faults.

[0025] 2. High reliability: The multi-layer self-healing design, consisting of a self-healing insulation layer, a self-healing sheath layer, and a self-healing gel filler, provides multiple layers of protection, greatly enhancing the cable harness's survivability in harsh environments.

[0026] 3. Long lifespan and low cost: Significantly extends the service life of the cable bundle, reducing downtime and maintenance costs caused by cable replacement.

[0027] 4. Wide applicability: The self-healing mechanism (thermal and optical triggering) is simple and easy to implement, and can be easily integrated into existing aviation cable manufacturing processes.

[0028] The self-healing aviation cable bundle provided by this invention forms a multi-layered, all-around self-healing protection system by setting a self-healing insulation layer on the outside of the conductors, setting a self-healing sheath layer on the outside of multiple conductors, and filling the sheath layer with a self-healing gel filler. When any part of the cable bundle is damaged, the self-healing insulation layer, the self-healing sheath layer, or the self-healing gel filler can automatically and quickly repair the damage under external stimuli such as heat, light, or microwaves through dynamic reversible bond recombination or microcapsule release of repair monomer polymerization, restoring the insulation and mechanical properties of the cable bundle, and effectively preventing faults such as short circuits and signal interruptions.

[0029] Compared with traditional aviation cables, this invention eliminates the need for regular manual inspections and replacements after malfunctions, which not only reduces maintenance costs and cycles but also enables timely response to sudden damage, significantly improving the safety and reliability of aircraft. At the same time, the addition of shape memory alloy wires or high-strength aramid fibers to the self-healing sheath material further enhances the mechanical properties of the cable bundle, extends its service life, and reduces the total life cycle cost of aircraft. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 A cross-sectional schematic diagram of the self-healing aviation cable bundle provided by the present invention;

[0032] Figure 2 A schematic diagram of the microcapsules provided by the present invention;

[0033] Figure 3 A schematic diagram of the self-healing aviation cable bundle when intact, provided by the present invention;

[0034] Figure 4 This invention provides a schematic diagram of the self-healing aviation cable harness repair process.

[0035] Figure 5 This is a schematic diagram of the self-healing aviation cable harness after repair provided by the present invention;

[0036] Figure 6 This is a schematic diagram of the self-repair mechanism of the microcapsules provided by the present invention.

[0037] The labels and corresponding component names in the attached diagram are: 1-Wire, 2-Self-healing insulation layer, 3-Self-healing sheath layer, 4-Self-healing gel filler, 5-Microcapsule, 6-Catalyst. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0039] The following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of the embodiments of the present invention, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0042] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0043] Furthermore, the use of terms such as "horizontal" or "vertical" does not imply that the component must be absolutely horizontal or vertical, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0044] In the description of the embodiments of the present invention, "multiple" means at least two.

[0045] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0046] Example 1

[0047] This embodiment 1 provides a self-healing aviation cable bundle, such as Figures 1-2 As shown, the self-healing aviation cable bundle consists of multiple conductors 1. The conductors 1 are made of aviation-grade copper alloy conductors 1, which have excellent conductivity and mechanical strength. Each conductor is covered with a self-healing insulation layer 2. After the conductors are twisted together, the gaps are filled with self-healing gel filler 4. The outermost layer is a self-healing sheath layer 3.

[0048] In this embodiment, combined with Figure 1As shown, conductor 1 is made of copper alloy core conductor 1, with a total of 19 conductors. One conductor 1 is in the very center, 6 conductors 1 are evenly distributed around the central conductor 1, and 12 conductors 1 are evenly distributed in a regular hexagon around the outside of the 6 conductors 1. Adjacent conductors 1 are in contact with each other. This arrangement ensures the structural compactness of the cable bundle and facilitates subsequent stranding.

[0049] Furthermore, a self-healing insulation layer 2 is coated on the outside of a single conductor 1, using a dynamically reversible covalent polymer material based on Diels-Alder bonds. The material of the self-healing insulation layer 2 is a furan-maleimide type Diels-Alder polymer. Preparation method: Functionalized furan monomers and maleimide monomers are polymerized at 80°C for 2 hours in an N,N-dimethylformamide solvent at a molar ratio of 1:1 to form a prepolymer. This prepolymer is then extruded onto the conductor 1 at a high temperature of 150°C and finally cooled to room temperature to solidify, resulting in a uniform self-healing insulation layer 2. Under heating conditions at 100°C, the Diels-Alder bonds in this self-healing insulation layer 2 reversibly break, increasing the material's fluidity and allowing it to fill damaged areas. Upon cooling, the bonds reform, completing the repair. This polymer material is synthesized through a stepwise polymerization reaction and possesses both excellent insulation and self-healing properties.

[0050] Combination Figure 1 and Figure 2 As shown, the self-healing gel filler 4 fills the gap between the conductor 1 with the self-healing insulation layer 2 and the self-healing sheath layer 3, with a filling amount of 100% of the gap volume. It employs a dynamic, reversible, non-covalent supramolecular gel based on hydrogen bonds. The self-healing gel filler 4 is a polyurethane-urea supramolecular gel, which forms a three-dimensional network structure through strong intermolecular hydrogen bonds. After filling, it forms a continuous sealing layer in the wire harness gap, the thickness of which is determined according to the gap size after the wire harness is twisted, ensuring complete filling. Preparation method: Isocyanate-terminated polyurethane prepolymer and a urea-containing chain extender are mixed at a mass ratio of 3:1 and injected into the wire harness gap under vacuum. Then, it is heated at 80°C for 1 hour to initiate a cross-linking reaction, forming a gel. When the wire harness gap is exposed due to sheath damage, the molecular chains on the gel surface can recombine through hydrogen bonds, sealing the crack.

[0051] Combination Figure 1 and Figure 2As shown, in this embodiment 1, the self-healing sheath layer 3 covers the exterior of multiple wires 1 and the self-healing gel filler 4. The self-healing sheath layer 3 is a braided layer, woven from glass fiber yarn impregnated with the aforementioned Diels-Alder polymer prepolymer, with a weaving density of 90%. After weaving, it is heat-cured at 120°C for 2 hours to completely cure the prepolymer, forming a sheath layer that combines self-healing and mechanical reinforcement. After the sheath layer is mechanically scratched, heating it to 100°C allows the Diels-Alder polymer at the damaged area to bond and repair itself, restoring its mechanical protective properties.

[0052] Furthermore, in this embodiment 1, combined with Figure 2 As shown, the matrix of the self-healing insulation layer 2 and the self-healing sheath layer 3 is epoxy resin, containing a microcapsule system. The microcapsule system is disposed within the self-healing insulation layer 2 and the self-healing sheath layer 3, and consists of urea-formaldehyde resin microcapsules 5 encapsulating dicyclopentadiene DCPD monomers and Grubbs catalyst 6 particles dispersed within them. This composite material is extruded onto the wire harness at 130°C to form the self-healing sheath layer 3. When the self-healing sheath layer 3 is damaged such as by scratches, the microcapsules 5 rupture, releasing the dicyclopentadiene monomers. The monomers come into contact with the surrounding Grubbs catalyst 6, undergoing a ring-opening metathesis polymerization reaction at room temperature, rapidly curing and filling the damaged areas, thus achieving the self-healing function.

[0053] Working principle

[0054] 1. Repair principle of self-healing insulation layer 2: combined with Figure 3 , Figure 4 and Figure 5 As shown, when the self-healing insulation layer 2 cracks or breaks due to mechanical wear, aging, or other reasons, heat is applied to the cable bundle. At this time, the Diels-Alder bonds in the insulation material undergo reversible breakage and recombination. The molecular chains at the damaged site re-approach and react under thermal activation, and the Diels-Alder bonds reform, connecting the broken molecular chains together, thereby achieving self-repair of the insulation layer.

[0055] 2. Repair Principle of Self-Healing Gel Filler 4: When the cable bundle is subjected to external forces such as compression or collision, causing the gap between the conductors 1 to widen or the gel filler to break, the hydrogen bonds between the gel molecular chains break. However, due to the dynamic reversibility of hydrogen bonds, without external stimulation, the molecular chains at the damaged site will reform hydrogen bonds through thermal motion and interaction, constructing a stable three-dimensional network structure and achieving self-repair. Applying slight heat stimulation (temperature 60-70℃) can accelerate the hydrogen bond recombination process, allowing it to continue filling the gaps between the conductors 1, providing insulation, buffering, and protection.

[0056] 3. Repair principle of self-healing sheath layer 3: combined with Figure 6 As shown, when the self-healing sheath layer 3 is damaged by sharp objects such as scratches or abrasions, the microcapsules 5 at the damaged site rupture due to external force, releasing dicyclopentadiene DCPD and other substances inside. Under the action of Grubbs catalyst particles 6, the dicyclopentadiene DCPD undergoes a polymerization reaction, rapidly solidifying to form a polymer with properties similar to the sheath layer matrix, filling the cracks or gaps at the damaged site and achieving self-healing of the sheath layer. After repair, the sheath layer can effectively block the erosion of the external environment, protecting the internal conductor 1 and insulation layer.

[0057] Example 2

[0058] This embodiment 2 provides a method for preparing a self-healing aviation cable bundle.

[0059] S1: Preparation of self-healing materials: Furan-maleimide type Diels-Alder polymer was synthesized according to the formulation and process of Example 1, which was used for self-healing insulation layer 2 and self-healing sheath layer 3; polyurethane urea supramolecular gel was used for self-healing gel filler 4;

[0060] S2: Insulation of conductor 1: The synthesized Diels-Alder polymer is uniformly coated onto the copper alloy conductor 1 at 150°C using a high-temperature extruder to form a self-healing insulation layer 2 with a thickness of 0.3 mm.

[0061] S3: Wire harness twisting: Twist 19 wires 1 with self-healing insulation layer 2 together to form a cable bundle core;

[0062] S4: Filled gel: In a vacuum environment with a vacuum degree of -0.09MPa, liquid polyurethane urea supramolecular gel precursor is injected, and then heated at 80℃ for 1 hour to initiate cross-linking and form a gel;

[0063] S5: Sheath: Glass fiber yarn impregnated with Diels-Alder polymer prepolymer is braided onto the outside of the cable bundle core using a braiding machine at a braiding density of 90%, and then heat-cured at 120°C for 2 hours to form the final self-healing aviation cable bundle.

[0064] Example 3

[0065] In this embodiment 3, the self-healing aviation cable bundle can be widely used in the power transmission and signal control systems of various aircraft such as civil airliners, military fighter jets, and helicopters.

[0066] Specific application scenarios include: signal transmission cables for aircraft engine control systems, power transmission cables at the connection between the wing and fuselage, signal cables between cockpit instruments and sensors, and cables for landing gear control systems.

[0067] In these application scenarios, aircraft experience continuous vibrations during flight and face complex environmental changes such as low temperatures at high altitudes, high temperatures on the ground, and humid conditions, making traditional cables highly susceptible to wear, aging, and damage. The self-healing aviation cable bundle of this invention, when subjected to minor wear due to vibration or aging and damage to the insulation and sheath layers caused by environmental changes, can automatically repair itself by receiving heat stimulation from the aircraft's own thermal management system or by receiving external stimulation from microwave or light irradiation equipment during ground maintenance.

[0068] For example, in aircraft engine control systems, cable bundles are exposed to high temperatures (e.g., 60-80°C) and strong vibrations for extended periods. The Diels-Alder bonds in the self-healing insulation layer 2 can automatically recombine under high temperatures, promptly repairing minor cracks caused by vibration. If the sheath layer is worn, the microcapsules 5 rupture to release the repair matrix, which is then rapidly cured and repaired under the action of the catalyst 6, preventing signal transmission interruptions in the engine control system and ensuring the normal operation of the aircraft.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0070] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A self-healing aviation cable harness, characterized in that, The device includes a conductor (1), a self-healing insulating layer (2) covering the outside of a single conductor (1), and a self-healing sheath layer (3) covering the outside of multiple conductors (1). The self-healing sheath layer (3) is filled with a self-healing gel filler (4). The self-healing insulating layer (2), the self-healing sheath layer (3), and the self-healing gel filler (4) automatically repair damage under external stimulation, such as heat, light, or microwaves. The self-healing insulating layer (2) and the self-healing sheath layer (3) are configured as polymer materials containing a microcapsule system; the microcapsule system includes microcapsules (5) containing repair monomers and a catalyst (6) dispersed in the repair monomers. When the material is damaged, the microcapsules (5) rupture to release the repair monomers, which are polymerized and repaired under the action of the catalyst (6).

2. The self-healing aviation cable harness according to claim 1, characterized in that, The self-healing insulating layer (2) and the self-healing sheath layer (3) are configured as polymer materials based on dynamic reversible covalent bonds.

3. The self-healing aviation cable bundle according to claim 2, characterized in that, The dynamic reversible covalent bonds in the polymer material are configured as Diels-Alder bonds, disulfide bonds, or oxime ester bonds.

4. The self-healing aviation cable harness according to claim 1, characterized in that, The microcapsules (5) are evenly distributed around the center of the self-healing sheath layer (3).

5. The self-healing aviation cable harness according to claim 1, characterized in that, The self-healing gel filler (4) is configured as a supramolecular gel based on dynamic reversible non-covalent bonds or dynamic reversible covalent bonds. The dynamic reversible non-covalent bonds include hydrogen bonds, ionic bonds, and metal coordination bonds, which can achieve self-repair through the recombination of molecular chains after damage.

6. The self-healing aviation cable harness according to claim 1, characterized in that, The multiple conductors (1) are arranged in a regular polygonal shape on the cross section.

7. A method for preparing a self-healing aviation cable bundle according to any one of claims 1-6, characterized in that, include: S1 Preparation of self-healing materials: synthesize or mix self-healing materials for forming a self-healing insulating layer (2), a self-healing gel filler (4), and a self-healing sheath layer (3); S2 Wire Insulation: The self-healing insulation material prepared in step S1 is coated onto a single wire (1) by extrusion process to form a wire (1) with a self-healing insulation layer (2). S3 Wire harness twisting: Multiple wires (1) with self-healing insulation layer (2) obtained in step S2 are twisted together to form a cable bundle core; S4 Filling Gel: Inject or press the self-healing gel material prepared in step S1 into the gaps of the stranded cable bundle core; S5 Wrapping Sheath: Outside the cable bundle core filled with self-healing gel filler (4), the self-healing sheath material prepared in step S1 is applied by braiding, wrapping or extrusion process to finally form a self-healing aviation cable bundle.

8. The preparation method according to claim 7, characterized in that, In step S1, the self-healing sheath material is a composite yarn containing shape memory alloy wires or high-strength aramid fibers, which is woven together with the self-healing polymer matrix to form a sheath layer that has both self-healing and mechanical reinforcement properties.

9. An application of the self-healing aviation cable harness according to any one of claims 1-6, characterized in that, Self-healing aviation cable bundles are used in aircraft.

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