A high common-mode rejection performance vehicle UTP cable and a manufacturing method thereof

Abstract

This invention provides a UTP cable for automotive applications with high common-mode suppression performance, comprising stranded cores and a sheath covering the stranded cores. The stranded cores are formed by twisting at least two insulated cores together. Each insulated core includes a conductor and an insulating layer covering the conductor. The sheath layer is made of a ferrite magnetic composite material. By mass percentage, the composition and content of the ferrite magnetic composite material are: 87% ferrite magnetic powder, 10% PA6 / PA12 mixed resin, 0.5% silane coupling agent, 0.8% polytetrafluoroethylene micropowder, 0.2% zinc stearate, 0.2% antioxidant 1010, and 0.2% antioxidant 168; wherein the mass ratio of PA6 / PA12 in the PA6 / PA12 mixed resin is 2:1. This invention also discloses a method for manufacturing a UTP cable for automotive applications with high common-mode suppression performance. Compared with the prior art, this invention achieves high common-mode suppression capability without the need for discrete magnetic rings.

Description

Technical Field

[0001] This invention relates to the field of automotive wire and cable technology, specifically to a UTP cable for vehicles with high common-mode rejection performance and its manufacturing method. Background Technology

[0002] Currently, automotive Ethernet technology is showing a trend towards high speed, centralization, and high electromagnetic compatibility. In terms of transmission rate, automotive Ethernet has achieved iterative upgrades from 100BASE-T1 (100Mbit / s) to 1000BASE-T1 (1Gbit / s) and ultra-high speeds to meet the real-time transmission needs of massive amounts of vehicle data. In terms of network architecture, automotive networks are gradually transforming from a distributed architecture to a domain-centralized architecture, with scenarios such as multi-sensor data fusion and real-time data processing across the entire domain continuously increasing the demands on network transmission bandwidth. In terms of environmental adaptability, the complex electromagnetic environment of vehicles places increasingly stringent requirements on the electromagnetic compatibility (EMC) of Ethernet communication. Ensuring the integrity and stability of vehicle signal transmission under complex operating conditions has become one of the core focuses of automotive Ethernet technology research and development.

[0003] The design, production and testing of the 100BASE-T1 vehicle Ethernet system mainly follow the international standard ISO 21111-8:2025 "Road vehicles - Ethernet - Part 8: 100 Mbit / s electrical Ethernet transmission media, components and testing". This standard sets strict radio frequency performance specifications for the core structure of the 100BASE-T1 system, such as transmission media, communication channels and supporting components, and is the core technical basis for the current application of vehicle 100 Mbit / s Ethernet systems. In practical applications of 100BASE-T1 automotive Ethernet systems, common-mode noise is the core cause of signal integrity degradation and poor system electromagnetic compatibility. It primarily stems from multiple factors, including mode switching caused by the asymmetry of the automotive communication system, interference coupling from complex external electromagnetic signals, and noise conduction from the automotive power supply system. To suppress common-mode noise, reduce radiated emissions (EMI) of the automotive Ethernet system, and mitigate the impact of electromagnetic interference on communication quality, existing technologies commonly employ noise reduction schemes such as attaching snap-on, clip-on, or integrated discrete ferrite cores to both ends of the Ethernet cable or at key communication nodes.

[0004] However, this traditional noise reduction solution has many inherent defects: On the one hand, the additional discrete ferrite magnetic ring increases the material cost of the vehicle network system, while also increasing the vehicle assembly process and operation time, thus increasing the overall vehicle production and assembly cost. Moreover, the magnetic ring component increases the overall weight of the vehicle wiring harness, which is not conducive to the development of vehicle lightweighting. On the other hand, the assembly precision and fit of the external discrete magnetic ring are difficult to control uniformly, which can easily cause problems such as signal transmission attenuation and impedance abnormalities, posing a potential risk to signal integrity. It is difficult to balance the noise reduction performance, assembly efficiency and communication stability of the vehicle Ethernet system, and cannot fully meet the high-quality communication needs of high-end intelligent vehicles at this stage. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a UTP cable for vehicles with high common mode rejection performance and a method for manufacturing the same, which has high common mode rejection capability without the need for adding discrete magnetic rings.

[0006] To achieve the above and other related objectives, the first aspect of the present invention provides a UTP cable for automotive applications with high common mode suppression performance, comprising stranded cores and a sheath covering the outer layer of the stranded cores, wherein the stranded cores are formed by at least two insulated cores twisted together, the insulated cores comprising conductors and an insulating layer covering the outer layer of the conductors, and the sheath layer is made of ferrite magnetic composite material. The composition and content of each component of the ferrite magnetic composite material by mass percentage are as follows: 87% ferrite magnetic powder, 10% PA6 / PA12 mixed resin, 0.5% silane coupling agent, 0.8% polytetrafluoroethylene micro powder, 0.2% zinc stearate, 0.2% antioxidant 1010, and 0.2% antioxidant 168; wherein the mass ratio of PA6 / PA12 in the PA6 / PA12 mixed resin is 2:1.

[0007] Furthermore, the conductor is made of seven strands of copper-magnesium alloy with a diameter of 0.16 mm twisted together.

[0008] Furthermore, the insulation layer is made of high-density polyethylene material with a thickness of 0.25-0.35 mm.

[0009] Furthermore, the stranding pitch of the stranded core is 25-35mm.

[0010] Furthermore, the thickness of the sheath layer is 0.8-1.2 mm.

[0011] A second aspect of this invention provides a method for manufacturing a UTP cable for automotive applications with high common-mode rejection performance, specifically comprising the following steps: S1: Sheath material preparation: The ferrite magnetic composite material formula is put into a high-speed mixer in proportion and mixed at 100~120℃ for 10~15min. After being mixed evenly, it is fed into the extruder hopper to obtain ferrite magnetic composite sheath material. S2: Sheath extrusion: The stranded and insulated conductors are fed into an extruder, and the ferrite composite polymer sheath material is extruded onto the outside of the insulation layer using an extrusion process. The extrusion temperature is controlled at 200~240℃, and the extrusion speed is 2m / min~5m / min. S3: Traction and winding: The cable is pulled by a traction machine, and the traction speed is controlled to match the extrusion speed to avoid stretching or loosening of the cable. Finally, the cable is wound into a coil.

[0012] Furthermore, it also includes step S4: finished product inspection: the cable is tested for high-frequency performance, electrical performance, mechanical performance, heat resistance and oil resistance.

[0013] Furthermore, in step S1, the ferrite magnetic powder undergoes a surface pretreatment process.

[0014] Furthermore, the surface pretreatment process includes: treating the ferrite magnetic powder with a silane coupling agent ethanol solution for 30-45 minutes, and then putting the treated ferrite magnetic powder and lubricant into a high-speed mixer and premixing them at a temperature of 90-120°C for 15-20 minutes.

[0015] Furthermore, in step S2, the extruder is a co-rotating twin-screw extruder.

[0016] The present invention has the following advantages: First, excellent common-mode rejection performance: Due to the uniform distribution of a high content of ferrite magnetic powder within the sheath layer, a distributed common-mode absorption network is formed. Tests show that the cable achieves an LCL / LCTL performance of ≥46dB in the 1-66MHz frequency band, a common-mode impedance of ≥120Ω at 100MHz, and a differential-to-common-mode conversion loss of ≤-40dB.

[0017] Second, it improves signal integrity: it eliminates impedance discontinuities that may be introduced by discrete magnetic rings as lumped elements, ensuring the stability of the 100Ω characteristic impedance throughout the entire link, thereby reducing differential-mode insertion loss (increase ≤0.5dB) and bit error rate.

[0018] Third, simplify the structure and reduce costs: integrating magnetic powder into the sheath eliminates all steps of purchasing, storing, and manually installing discrete magnetic rings, significantly reducing the bill of materials cost and assembly time of the entire vehicle wiring harness.

[0019] Fourth, it meets stringent automotive requirements: the product meets the mechanical, heat, oil, and electrical performance requirements of ISO 19642-12 standard and can be directly applied to existing vehicle wiring architectures. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of the cable of the present invention.

[0022] Among them: 1. Stranded core; 11. Insulated core; 111. Conductor; 112. Insulation layer; 2. Sheath layer. Detailed Implementation Example 1

[0023] This embodiment provides a UTP cable for automotive applications with high common-mode suppression performance, comprising a stranded core 1 and a sheath layer 2 covering the outer layer of the stranded core 1, wherein: The stranded core 1 is composed of at least two insulated cores 11 twisted together, with a twist pitch of 25-35mm and a right-hand twisting direction. Each insulated core 11 includes a conductor 111 and an insulation layer 112 covering the conductor 111. The conductor 111 is composed of seven copper-magnesium alloy strands with a diameter of 0.16mm. The insulation layer 112 is made of high-density polyethylene with a thickness of 0.25-0.35mm, ensuring withstand voltage performance and impedance control, with a dielectric constant ≤2.3 (1MHz) and insulation resistance ≥10¹. 4 Ω·km, ensuring good insulation performance and mechanical protection.

[0024] The sheath layer 2 is made of ferrite magnetic composite material with a thickness of 0.8-1.2 mm. By mass percentage, the composition and content of each component of the ferrite magnetic composite material are as follows: 87% ferrite magnetic powder, 10% PA6 / PA12 mixed resin, 0.5% silane coupling agent, 0.8% polytetrafluoroethylene micro powder, 0.2% zinc stearate, 0.2% antioxidant 1010, and 0.2% antioxidant 168. The mass ratio of PA6 / PA12 in the PA6 / PA12 mixed resin is 2:1.

[0025] The automotive UTP cable with high common-mode rejection performance provided in this embodiment has the following advantages: First, excellent common-mode rejection performance: Due to the uniform distribution of a high content of ferrite magnetic powder within the sheath layer, a distributed common-mode absorption network is formed. Tests show that the cable achieves an LCL / LCTL performance of ≥46dB in the 1-66MHz frequency band, a common-mode impedance of ≥120Ω at 100MHz, and a differential-to-common-mode conversion loss of ≤-40dB.

[0026] Second, it improves signal integrity: it eliminates impedance discontinuities that may be introduced by discrete magnetic rings as lumped elements, ensuring the stability of the 100Ω characteristic impedance throughout the entire link, thereby reducing differential-mode insertion loss (increase ≤0.5dB) and bit error rate.

[0027] Third, it meets stringent automotive requirements: the product meets the mechanical, heat, oil, and electrical performance requirements of ISO 19642-12 standard and can be directly applied to existing vehicle wiring architectures. Example 2

[0028] This embodiment provides a method for manufacturing a high common-mode rejection performance automotive UTP cable, including the following steps: S1: Sheath material preparation: According to the ferrite magnetic composite material formula, put it into a high-speed mixer in proportion and mix at 100~120℃ for 10~15min. After mixing evenly, feed it into the extruder hopper to obtain ferrite magnetic composite sheath material. S2: Sheath extrusion: The twisted and insulated conductors are fed into a co-rotating twin-screw extruder, and the ferrite composite polymer sheath material is extruded onto the outside of the insulation layer using an extrusion process. The extrusion temperature is controlled at 200~240℃, and the extrusion speed is 2m / min~5m / min to ensure that the sheath layer has a uniform thickness, no air bubbles, and a smooth surface. S3: Traction and winding: The traction machine pulls the cable, and the traction speed is controlled to match the extrusion speed to avoid cable stretching or slack. Finally, the cable is wound into a coil. S4: Finished Product Inspection: The cable will be tested for high-frequency performance, electrical performance, mechanical performance, heat resistance and oil resistance.

[0029] To address issues such as increased injection pressure, molding difficulties, restricted magnetic particle rotation, low orientation, decreased magnetic flux, reduced processing characteristics, rough surface, and internal gas generation caused by excessive magnetic powder filling, a surface pretreatment process is required in step S1. This process includes treating the ferrite magnetic powder with a silane coupling agent ethanol solution for 30-45 minutes, followed by adding the treated ferrite magnetic powder and lubricant to a high-speed mixer and premixing at 90-120°C for 15-20 minutes.

[0030] Comparative Example To demonstrate the inventiveness of this invention, a conventional automotive Ethernet cable was provided, with discrete ferrite cores attached to both ends of the cable. Its insertion loss (attenuation) characteristics were measured using the same test method. The test results are shown in Table 1.

[0031] As shown in Table 1, although adding discrete ferrite cores can suppress common-mode interference, it will introduce significant insertion loss, especially in the 300-800MHz band, which is as high as 18-20dB. This seriously affects the signal transmission quality, leading to tight link budget and increased bit error rate.

[0032] Table 1: Differential mode insertion loss of the cable with discrete ferrite core cable

[0033] The automotive UTP cable with high common-mode rejection performance provided in Example 1 has a differential-mode insertion loss increase of ≤0.5dB under the same test conditions. This indicates that while ensuring common-mode rejection performance, the automotive UTP cable with high common-mode rejection performance provided in this example hardly increases differential-mode signal attenuation, and has significant performance advantages.

[0034] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high common mode rejection performance UTP cable for automotive applications, comprising a twisted core and a jacket layer covering the outer layer of the twisted core, the twisted core being formed by twisting at least two insulated cores with respect to each other, the insulated core comprising a conductor and an insulation layer covering the outer layer of the conductor, characterized in that: The sheath layer is made of ferrite magnetic composite material; The composition and content of each component of the ferrite magnetic composite material by mass percentage are as follows: 87% ferrite magnetic powder, 10% PA6 / PA12 mixed resin, 0.5% silane coupling agent, 0.8% polytetrafluoroethylene micro powder, 0.2% zinc stearate, 0.2% antioxidant 1010, and 0.2% antioxidant 168; wherein the mass ratio of PA6 / PA12 in the PA6 / PA12 mixed resin is 2:

1.

2. The automotive UTP cable with high common-mode rejection performance according to claim 1, characterized in that: The conductor is made of seven strands of copper-magnesium alloy with a diameter of 0.16 mm.

3. The automotive UTP cable with high common-mode rejection performance according to claim 1, characterized in that: The insulation layer is made of high-density polyethylene material with a thickness of 0.25-0.35 mm.

4. The automotive UTP cable with high common-mode rejection performance according to claim 1, characterized in that: The stranding pitch of the stranded core is 25-35mm.

5. The automotive UTP cable with high common-mode rejection performance according to claim 1, characterized in that: The thickness of the sheath layer is 0.8-1.2 mm.

6. A method for manufacturing a high common-mode rejection performance automotive UTP cable according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Sheath material preparation: The ferrite magnetic composite material formula is put into a high-speed mixer in proportion and mixed at 100~120℃ for 10~15min. After being mixed evenly, it is fed into the extruder hopper to obtain ferrite magnetic composite sheath material. S2: Sheath extrusion: The stranded and insulated conductors are fed into an extruder, and the ferrite composite polymer sheath material is extruded onto the outside of the insulation layer using an extrusion process. The extrusion temperature is controlled at 200~240℃, and the extrusion speed is 2m / min~5m / min. S3: Traction and winding: The cable is pulled by a traction machine, and the traction speed is controlled to match the extrusion speed to avoid stretching or loosening of the cable. Finally, the cable is wound into a coil.

7. A method for manufacturing a high common-mode rejection performance automotive UTP cable according to claim 6, characterized in that: It also includes step S4: finished product inspection: the cable is tested for high frequency performance, electrical performance, mechanical performance, heat resistance and oil resistance.

8. A method for manufacturing a high common-mode rejection performance automotive UTP cable according to claim 6, characterized in that: In step S1, the ferrite magnetic powder undergoes a surface pretreatment process.

9. A method for manufacturing a high common-mode rejection performance automotive UTP cable according to claim 8, characterized in that: The surface pretreatment process includes: treating the ferrite magnetic powder with a silane coupling agent ethanol solution for 30-45 minutes, and then putting the treated ferrite magnetic powder and lubricant into a high-speed mixer and premixing them at a temperature of 90-120°C for 15-20 minutes.

10. A method for manufacturing a high common-mode rejection performance automotive UTP cable according to claim 6, characterized in that: In step S2, the extruder is a co-rotating twin-screw extruder.

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