Lightweight composite structure automobile wire with high shielding effectiveness and preparation method thereof

Abstract

The invention discloses a lightweight composite structure automobile wire with high shielding effectiveness, which comprises a conductor which is a porous structure aluminum alloy conductor and a graphene copper composite layer coated on the conductor, the graphene copper composite layer is coated with the insulating layer; the inner shielding layer is wound on the insulating layer; the outer shielding layer is coated on the inner shielding layer; and the outer sheath is coated on the outer shielding layer. According to the invention, the weight is reduced, and the shielding effectiveness is improved.

Description

Technical Field

[0001] This invention belongs to the field of automotive cable technology, specifically relating to a lightweight composite structure automotive wire with high shielding effectiveness and its preparation method. Background Technology

[0002] Automotive wiring harnesses play a vital role as the hub connecting various electrical systems in a vehicle. However, with the increasing demand for electromagnetic interference resistance in new energy vehicles, such as power cables for high-voltage systems (e.g., 800V platforms) in new energy vehicles, the cables need to be lightweight while resisting high-frequency interference from inverters. Lines for motor resolvers, eddy current sensors, and low-voltage communication need to avoid signal crosstalk and adapt to wiring in confined spaces.

[0003] However, traditional automotive shielded cables mostly use copper wire braided shielding layers, which are heavy and have limited bending radius. Aluminum foil shielding layers are easily damaged, and the high-frequency shielding effectiveness is insufficient (significant attenuation at >100MHz). Lightweight materials (such as carbon fiber) often have poor conductivity and are difficult to balance electromagnetic compatibility (EMC). Therefore, they cannot meet the current automotive requirements for high shielding performance, lightweight, and high integration. Summary of the Invention

[0004] This invention provides a lightweight composite structure automotive wire with high shielding effectiveness and its preparation method. This invention not only reduces weight but also improves shielding effectiveness.

[0005] The technical solutions to the above technical problems are as follows: A lightweight composite structure automotive wire with high shielding effectiveness includes a conductor, the conductor being a porous aluminum alloy conductor, and further includes: A graphene-copper composite layer coated on a conductor; An insulating layer covering the graphene-copper composite layer; An inner shielding layer wrapped around an insulating layer; An outer shielding layer covering the inner shielding layer; The outer sheath covering the outer shielding layer.

[0006] Furthermore, the porosity of the porous aluminum alloy conductor is 15-20%, and the thickness of the graphene-copper composite layer is 2-5 μm.

[0007] Furthermore, the insulating layer is made of a mixture of modified polypropylene and boron nitride nanoparticles, with a dielectric loss of less than 0.001 and a temperature resistance rating of -40 to 150℃.

[0008] Furthermore, the inner shielding layer is made of nano-silver coated polyimide film, and the inner shielding layer is wound on the insulating layer in a spiral manner, with a thickness of ≤50μm.

[0009] Furthermore, the outer shielding layer adopts a mixed woven mesh structure of carbon fiber and copper-nickel alloy wire, with carbon fiber accounting for 30-50%.

[0010] The outer sheath is made of thermoplastic polyurethane and conductive carbon black, with the conductive carbon black having a dot ratio of 3-5%.

[0011] A method for preparing a lightweight composite structure automotive wire with high shielding effectiveness includes the following steps: S1, the conductor is prepared into a porous aluminum alloy rod by powder metallurgy, and the porous aluminum alloy rod is continuously drawn into a conductor; S2, after coating a conductor with a copper layer, graphene is generated on the copper surface using a chemical vapor deposition method to form a graphene-copper composite layer. S3, after mixing modified polypropylene with boron nitride nanoparticles, it is extruded onto the surface of the graphene copper composite layer to form an insulating layer. S4, an inner shielding layer is formed by magnetron sputtering of nano-metallic silver on both sides of a polyimide film. The inner shielding layer is spirally wound onto an insulating layer and then sealed with laser edge sealing. S5, carbon fiber and copper-nickel alloy wire are braided together on the inner shielding layer by a braiding machine to form an outer shielding layer with a mesh structure that covers the inner shielding layer; S6, a mixture of thermoplastic polyurethane and conductive carbon black is extruded through an extruder onto the surface of the outer shielding layer to form an outer sheath.

[0012] In this invention, the conductor uses a porous aluminum alloy, which reduces the cable weight by 40% compared to copper cables of the same specifications. After coating the surface of the porous aluminum alloy conductor with a graphene-copper composite layer, the current carrying capacity is improved due to the ultra-high carrier mobility of graphene (theoretical conductivity 100 MS / m). The inner shielding layer contains nano-metallic silver and carbon fiber, which can achieve a full-band shielding effectiveness of ≥70dB (test standard: ISO 11452). Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a lightweight composite automotive wire with high shielding efficiency.

[0014] Labels in the attached diagram: Conductor 1, graphene-copper composite layer 2, insulation layer 3, inner shielding layer 4, outer shielding layer 5, outer sheath 6. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0016] like Figure 1As shown, a lightweight composite structure automotive wire with high shielding efficiency according to the present invention includes a conductor 1, a graphene copper composite layer 2, an insulation layer 3, an inner shielding layer 4, an outer shielding layer 5, and an outer sheath 6. The components and their relationships are described in detail below.

[0017] A graphene-copper composite layer 2 is coated on a conductor 1, which is a porous aluminum alloy conductor with a porosity of 15-20% and a thickness of 2-5 μm. In this embodiment, the porosity of the porous aluminum alloy conductor is preferably 17%, and the thickness of the graphene-copper composite layer 2 is preferably 5 μm.

[0018] Insulating layer 3 is coated on graphene copper composite layer 2. The material of insulating layer 3 is a mixture of modified polypropylene and boron nitride nanoparticles. The dielectric loss of insulating layer 3 is less than 0.001 and the temperature resistance is -40-150℃.

[0019] The inner shielding layer 4 is wound around the insulating layer 3. The inner shielding layer 4 is made of nano-silver-plated polyimide film. The inner shielding layer 4 is wound around the insulating layer 3 in a spiral manner. The thickness of the inner shielding layer 4 is ≤50μm.

[0020] The outer shielding layer 5 covers the inner shielding layer 4. The outer shielding layer 5 adopts a mesh structure of carbon fiber and copper-nickel alloy wire, wherein the carbon fiber accounts for 30-50%, and in this embodiment, the carbon fiber accounts for 45%.

[0021] The outer sheath 6 covers the outer shielding layer 5. The outer sheath 6 is made of thermoplastic polyurethane and conductive carbon black, wherein the conductive carbon black has a dot ratio of 3-5%.

[0022] The method for preparing the above-mentioned lightweight composite structure automotive wire with high shielding effectiveness includes the following steps: S1, the conductor is prepared into a porous aluminum alloy rod by powder metallurgy, and the porous aluminum alloy rod is continuously drawn into conductor 1.

[0023] S2, after coating the conductor 1 with a copper layer, graphene is generated on the copper surface by chemical vapor deposition to form a graphene-copper composite layer 2. The copper layer can be formed on the surface of the conductor 1 by electroplating copper.

[0024] S3, modified polypropylene and boron nitride nanoparticles are mixed and extruded onto the surface of graphene copper composite layer 2 to form insulating layer 3. The extrusion temperature of insulating layer 3 is 175℃.

[0025] S4. An inner shielding layer 4 is formed by magnetron sputtering nano-silver onto both sides of a polyimide film. The inner shielding layer 4 is a polyimide film with nano-silver coating spirally wound, with a thickness ≤50μm. In this embodiment, the thickness of the inner shielding layer 4 is 30μm. A continuous conductive layer is achieved through magnetron sputtering to shield low-frequency interference signals, such as signals less than 1MHz. After the inner shielding layer 4 is spirally wound onto the insulating layer 3, the edges of the inner shielding layer 4 are sealed using laser sealing.

[0026] S5, carbon fiber and copper-nickel alloy wire are braided together on the inner shielding layer 4 using a braiding machine to form an outer shielding layer 5 with a mesh structure that covers the inner shielding layer 4. The outer shielding layer 5 can shield high-frequency interference signals, such as signals greater than 100MHz.

[0027] S6, a mixture of thermoplastic polyurethane and conductive carbon black is extruded onto the surface of the outer shielding layer 5 through an extruder to form an outer sheath 6. The outer sheath 6 is made of thermoplastic polyurethane and conductive carbon black, forming a dissipative antistatic layer to prevent charge accumulation, wherein the conductive carbon black has a dot ratio of 5%.

[0028] The performance comparison data of the wire prepared in this embodiment for use in automobiles with that of traditional copper cables are as follows: index Traditional copper cable This invention Weight (g / m, 2.5mm²) 56 32 Shielding effectiveness (@1GHz) 50dB 78dB Finally, it should be noted that the above-described embodiments are merely preferred embodiments of the present invention used to illustrate the technical solutions of the present invention, and are not intended to limit them, much less limit the scope of protection of the present invention; although the 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 or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the scope of protection of the claims.

Claims

1. A high shielding effectiveness lightweight composite structured automotive wire comprising a conductor (1), characterized in that, The conductor (1) is a porous structure aluminum alloy conductor, further comprising: a graphene copper composite layer (2) coated on the conductor (1); an insulating layer (3) coated on the graphene copper composite layer (2); an inner shielding layer (4) wound on the insulating layer (3); an outer shielding layer (5) coated on the inner shielding layer (4); an outer sheath (6) coated on the outer shielding layer (5).

2. The high shielding effectiveness lightweight composite structure automotive wire of claim 1, wherein, The porosity of the porous structure aluminum alloy conductor is 15-20%, and the thickness of the graphene copper composite layer (2) is 2-5 μm.

3. The high shielding effectiveness lightweight composite structural wire of claim 1, wherein, The material of the insulating layer (3) is a mixture of modified polypropylene and boron nitride nano, and the dielectric loss of the insulating layer (3) is less than 0.001, and the temperature resistance level is -40-150℃.

4. The high shielding effectiveness lightweight composite structural automotive wire of claim 1, wherein, The inner shielding layer (4) adopts a nano metal silver plated polyimide film, and the inner shielding layer (4) is wound on the insulating layer (3) in a spiral winding manner, and the thickness of the inner shielding layer (4) is ≤50 μm.

5. The high shielding effectiveness lightweight composite structural automotive wire of claim 1, wherein, The outer shielding layer (5) adopts a carbon fiber and copper-nickel alloy wire mixed net structure, wherein the carbon fiber accounts for 30-50%.

6. The high shielding effectiveness lightweight composite structural automotive wire of claim 1, wherein, The material of the outer sheath (6) is composed of thermoplastic polyurethane and conductive carbon black, wherein the point ratio of conductive carbon black is 3-5%.

7. The method for preparing the lightweight composite structure automotive wire with high shielding effectiveness as described in claims 1 to 6, characterized in that, The method comprises the following steps: S1, the conductor is prepared into a porous aluminum alloy bar by powder metallurgy, and the porous aluminum alloy bar is continuously drawn into the conductor (1); S2, after coating a copper layer on the conductor (1), graphene is generated on the surface of the copper by chemical vapor deposition to form a graphene copper composite layer (2); S3, after mixing modified polypropylene and boron nitride nano, the mixture is extruded onto the surface of the graphene copper composite layer (2) to form an insulating layer (3); S4, after nano metal silver is deposited on both sides of the polyimide film by magnetron sputtering, the inner shielding layer (4) is formed, and the inner shielding layer (4) is spirally wound on the insulating layer (3), and then the inner shielding layer (4) is sealed by laser sealing; S5, carbon fiber and copper-nickel alloy wire are mixed on the inner shielding layer (4) by a braiding machine to form an outer shielding layer (5) of a net structure for coating the inner shielding layer (4); S6, a mixture of thermoplastic polyurethane and conductive carbon black is extruded onto the surface of the outer shielding layer (5) by an extruder to form an outer sheath (6).

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