Small-diameter vehicle-mounted photoelectric hybrid cable and twisting method thereof

Abstract

The invention relates to a small-diameter vehicle-mounted photoelectric hybrid cable and a twisting method thereof, and belongs to the technical field of vehicle-mounted photoelectric hybrid cables, the small-diameter vehicle-mounted photoelectric hybrid cable comprises a core optical unit, a core optical unit and a core optical unit, the core optical unit comprises a tight-buffered optical fiber and a fiber braid layer wrapping the tight-buffered optical fiber; a plurality of power lines, the plurality of power lines and the core light unit are twisted to form a cable core; the wrapping tape layer is coated on the cable core; and the outer sheath is wrapped on the belting layer. Only the tight tube optical fiber is reserved through the core optical unit, the tight tube optical fiber is directly wrapped by the fiber braid layer to provide mechanical protection, and the fiber braid layer serves as a flexible outer layer to replace a traditional sheath, so that the tensile resistance and bending resistance of the optical fiber are maintained, the thickness redundancy of an extra sheath layer is avoided, the traditional sheath layer is omitted, and the cost is reduced. The diameter of the photoelectric hybrid cable is obviously reduced.

Description

Technical Field

[0001] This application relates to the field of vehicle-mounted optoelectronic hybrid cable technology, and in particular to a thin-diameter vehicle-mounted optoelectronic hybrid cable and its stranding method. Background Technology

[0002] With the accelerated advancement of automotive intelligence and electrification, in-vehicle wiring harness systems are evolving from single-function to multi-functional integration. In high-frequency dynamic bending applications such as cameras, advanced driver assistance systems, electric seat adjustment, and door control, the performance of the optoelectronic hybrid cable, as the core carrier for simultaneously achieving high-speed signal transmission and power supply, directly determines the reliability and space utilization of the entire vehicle.

[0003] However, current mainstream hybrid optoelectronic cables generally adopt a large-diameter design, with an outer diameter typically exceeding 5.0 mm, far exceeding the physical limitations of door wiring harness channels, resulting in severely hampered wiring efficiency. Specifically, traditional cables require additional redundant space when installed in confined spaces, forcing engineers to adopt detour wiring solutions. This not only extends the assembly cycle but also squeezes the space for critical functional components such as sensor brackets and airbag modules, directly reducing the overall vehicle integration and structural compactness. More importantly, the large-diameter design continuously increases the overall vehicle weight, creating a sharp contradiction with the industry's lightweighting strategy. Summary of the Invention

[0004] This application provides a thin-diameter vehicle-mounted hybrid optical and electrical cable and its stranding method to solve the problem that hybrid optical and electrical cables in related technologies generally adopt a large-diameter design, which makes it difficult to meet the needs of narrow space layout and lightweight development.

[0005] In a first aspect, a narrow-diameter vehicle-mounted optical-electric hybrid cable is provided, comprising: a core optical unit, which includes a tight-buffered optical fiber and a fiber braided layer wrapped around the tight-buffered optical fiber; a power line, which is provided with a plurality of power lines, the plurality of power lines being twisted together with the core optical unit to form a cable core; a wrapping layer, which covers the cable core; and an outer sheath, which wraps around the wrapping layer.

[0006] In some embodiments, the tight-buffered optical fiber includes an optical fiber and a tight-buffered layer covering the optical fiber, wherein the outer diameter of the tight-buffered optical fiber is 0.35~0.95mm.

[0007] In some embodiments, the fiber braided layer includes an aramid braided layer with an outer diameter of 0.7 to 1.3 mm.

[0008] In some embodiments, the power cord includes a conductor and an insulating layer covering the conductor, and the outer diameter of the power cord is 1.1 to 1.3 mm.

[0009] In some embodiments, the insulating layer is a cross-linked, low-smoke, halogen-free flame-retardant polyolefin material.

[0010] In some embodiments, the wrapping layer is configured as polyester tape or nonwoven fabric.

[0011] In some embodiments, the outer diameter of the outer sheath is 3-4 mm, and the outer sheath is configured as one of thermoplastic polyurethane, low-smoke halogen-free flame-retardant polyolefin, polyvinyl chloride, or ethylene-tetrafluoroethylene copolymer.

[0012] In a second aspect, a stranding method for a thin-diameter vehicle-mounted optical-electric hybrid cable as described in any of the first aspects is provided, comprising: obtaining the instantaneous stranding pitch of the cable core at the current axial position based on the real-time axial position of the cable core, the reference pitch value, the pitch change amplitude, and the pitch change period; obtaining the real-time rotational angular velocity of the stranding head based on the instantaneous stranding pitch and the constant traction speed; and using a stranding machine to complete the stranding of the core optical unit and the power line based on the real-time rotational angular velocity of the stranding head.

[0013] In some embodiments, the equivalent diameter of the cable core is obtained based on the outer diameter of the core optical unit or the outer diameter of the power line, and the stranding gap correction value; a reference pitch value is obtained based on the equivalent diameter of the cable core and the stranding coefficient; and the equivalent diameter of the cable core is taken as an integer, and the stranding coefficient is in the range of 12 to 20.

[0014] In some embodiments, the ratio of the pitch change amplitude to the reference pitch value ranges from 0.1 to 0.25, and the pitch change period ranges from 1.0 to 3.0 m.

[0015] The beneficial effects of the technical solution provided in this application include: This application provides a small-diameter vehicle-mounted optoelectronic hybrid cable and its stranding method. Since this application retains only the tight-buffered optical fiber in the core optical unit and provides mechanical protection by directly wrapping the tight-buffered optical fiber with the fiber braided layer, the fiber braided layer, as a flexible outer layer, replaces the traditional sheath. This maintains the tensile and bending resistance of the optical fiber and avoids the thickness redundancy of the additional sheath layer. It eliminates the need for the traditional sheath layer, achieving a significant reduction in the diameter of the optoelectronic hybrid cable. This effectively overcomes the physical limitations of narrow wiring harness channels such as vehicle doors and promotes vehicle lightweighting by reducing material usage. The wrapping layer, as a transition layer between the cable core and the outer sheath, effectively fixes the internal structure, prevents the stranding unit from loosening during bending, and fills the gaps on the irregular surface of the cable core, providing a flat covering base for the outer sheath. The outer sheath provides necessary environmental protection. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of a thin-diameter vehicle-mounted optical-electric hybrid cable is provided for embodiments of this application; Figure 2 A schematic diagram illustrating the core optical unit of a thin-diameter vehicle-mounted optoelectronic hybrid cable provided for embodiments of this application; Figure 3 This is a schematic flowchart illustrating a stranding method for a thin-diameter vehicle-mounted optical-electric hybrid cable, provided as an embodiment of this application.

[0018] In the diagram: 1. Core optical unit; 10. Tight-buffered optical fiber; 100. Optical fiber; 101. Tight-buffered layer; 11. Fiber braided layer; 2. Power line; 20. Conductor; 21. Insulation layer; 3. Wrapping tape layer; 4. Outer sheath. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] This application provides a thin-diameter vehicle-mounted hybrid optical and electrical cable and its stranding method, which can solve the problem that the hybrid optical and electrical cables in related technologies generally adopt a large-diameter design, which makes it difficult to meet the needs of narrow space layout and lightweight development.

[0021] Reference Figure 1-2 A thin-diameter vehicle-mounted hybrid optical-electric cable includes a core optical unit 1, power lines 2, a wrapping layer 3, and an outer sheath 4. The core optical unit 1 includes a tight-buffered optical fiber 10 and a fiber braided layer 11 wrapped around the tight-buffered optical fiber 10. Several power lines 2 are provided, preferably two in this application. The two power lines 2 and the core optical unit 1 are twisted together using methods including but not limited to SZ twisting to form the cable core. The wrapping layer 3 covers the cable core, and the outer sheath 4 is wrapped around the wrapping layer 3. In this application, the outer diameter of the hybrid optical-electric cable is less than 4.0 mm.

[0022] In this application, the core optical unit 1 employs a tight-buffered optical fiber 10 and a fiber braided layer 11, eliminating the need for a plastic sheath. While providing high-strength mechanical protection, its high modulus and low density characteristics ensure both tensile strength and bending fatigue resistance in high-frequency dynamic bending scenarios such as those in vehicle doors, while avoiding increased weight. The power line 2 is scientifically twisted with the core optical unit 1 to form a compact cable core, ensuring overall cable flexibility, preventing internal units from rubbing against each other during bending, and effectively avoiding diameter expansion caused by traditional parallel arrangements. The wrapping layer 3, as a key transition structure, tightly wraps the cable core, filling irregular surface gaps and providing a flat covering base for the outer sheath 4, further controlling the overall outer diameter. Ultimately, through the synergistic optimization of the above layers, the outer diameter of the optoelectronic hybrid cable is successfully controlled below 4.0mm, significantly lower than the traditional design of over 5.0mm. This fundamentally solves the problem of low wiring efficiency caused by limited space in vehicle door wiring harness channels, eliminating the need for additional redundant space or detour wiring schemes, and significantly shortening the assembly cycle.

[0023] Specifically, in this application, the tight-buffered optical fiber 10 includes an optical fiber 100 and a tight-buffered layer 101 covering the optical fiber 100. A coating layer is also provided between the tight-buffered layer 101 and the optical fiber 100. This coating layer serves as a basic protective layer directly covering the surface of the optical fiber 10 (not shown in the figure). The outer diameter of the tight-buffered optical fiber 10 is 0.35~0.95mm. The tight-buffered layer 101 is made of thermoplastic polyester elastomer or ethylene-tetrafluoroethylene copolymer. As the core optical transmission unit of the thin-diameter vehicle-mounted optoelectronic hybrid cable, the tight-buffered optical fiber 10, with its outer diameter of 0.35~0.95mm, compresses the radial dimension of the optical unit while ensuring the transmission performance of the optical fiber 100, laying a physical foundation for controlling the overall cable outer diameter to below 4.0mm. The tight-buffered layer 101 is made of thermoplastic polyester elastomer or ethylene-tetrafluoroethylene copolymer, taking into full account the stringent requirements of the special automotive application environment: Thermoplastic polyester elastomer, with its excellent high elastic modulus and low-temperature flexibility, allows the tight-buffered optical fiber 10 to maintain good bending performance even at low temperatures, perfectly adapting to high-frequency dynamic bending scenarios such as car doors. Its wear resistance and oil resistance effectively resist mechanical friction and chemical corrosion during automotive assembly and use. Meanwhile, the ethylene-tetrafluoroethylene copolymer material, with its excellent heat resistance and low coefficient of friction, performs outstandingly in high-temperature applications, ensuring signal transmission stability in high-temperature environments such as engine compartments and significantly reducing cable routing resistance in narrow channels. Both high-performance materials provide excellent mechanical protection, preventing micro-bending loss during bending of the optical fiber 100 and avoiding the weight increase problem associated with traditional metal armor, achieving a perfect balance between protective performance and lightweight design. Through this precisely controlled tight-fitting structure design and the application of advanced materials, the problems of difficult wiring and low assembly efficiency caused by the excessive outer diameter of traditional optoelectronic hybrid cables have been improved. It also significantly improves the reliability and service life of cables in the complex automotive environment, providing key foundational support for the intelligent and lightweight development of automobiles.

[0024] In this application, the fiber braided layer 11 is preferably an aramid braided layer with an outer diameter of 0.7~1.3mm. The aramid braided layer, with its excellent high strength and high modulus properties, constructs a strong mechanical protective barrier within an extremely thin thickness range of 0.7~1.3mm, effectively resisting vibration, compression, and bending stress generated during vehicle operation. It is particularly effective in high-frequency dynamic bending scenarios such as car doors and electric seats, significantly reducing the risk of micro-bending loss in optical fiber 100 and ensuring long-term stability of optical signal transmission. Furthermore, its excellent heat resistance ensures structural stability in high-temperature environments, while its low coefficient of thermal expansion avoids the impact of dimensional fluctuations caused by temperature changes on the performance of optical fiber 100.

[0025] In this application, the power cord 2 includes a conductor 20 and an insulation layer 21 covering the conductor 20. The outer diameter of the power cord 2 is 1.1~1.3mm. The conductor 20 is a multi-strand stranded tinned copper wire with a specification of 24AWG to 28AWG; the insulation layer 21 is a cross-linked low-smoke halogen-free flame-retardant polyolefin material.

[0026] In this application, the power cable 2 adopts an outer diameter design of 1.1~1.3mm. While ensuring power transmission capacity, it achieves optimal size matching with the tight-buffered optical fiber 10 and the aramid braided layer, jointly controlling the overall cable outer diameter to below 4.0mm. This fundamentally solves the problem of limited space in the vehicle door wiring harness channel caused by the excessively large outer diameter of traditional cables. The conductor 20 uses multi-strand stranded tinned copper wire of 24AWG to 28AWG specifications, with a safe continuous current carrying capacity of approximately 2~3A to meet the power supply requirements of vehicle-mounted equipment such as individual cameras, small sensors, or controllers. The smaller outer diameter matches the size of the optical unit, which is beneficial for optical cable stranding. The multi-strand stranded structure significantly improves the flexibility and fatigue resistance of the conductor 20, enabling the power cable 2 to withstand tens of thousands of bends without breakage in high-frequency dynamic bending applications such as vehicle doors and electric seats. The tin plating treatment not only enhances the corrosion resistance of the copper wire, effectively resisting the erosion of moisture and salt spray in the automotive environment, but also improves the welding reliability, ensuring the long-term stability of the electrical connection. The insulation layer 21 is made of cross-linked low-smoke halogen-free flame-retardant polyolefin material. The cross-linking process significantly improves the material's heat resistance and mechanical strength, enabling it to adapt to the working environment of high-temperature areas such as the engine compartment. The low-smoke and halogen-free characteristics greatly reduce the generation of toxic fumes in extreme conditions, meeting automotive safety standards and improving occupant escape safety. The excellent flame-retardant properties meet the stringent fire protection requirements of automotive wiring harnesses, while the low-density characteristics of the polyolefin material further reduce the weight of the cable. The precisely designed power line 2 and the core optical unit 1 are scientifically twisted together to form a compact and highly flexible cable core. Through mutual support, the overall tensile strength is enhanced, eliminating the need for extra redundant space when wiring in narrow door wiring harness channels, greatly improving assembly efficiency.

[0027] In this application, the wrapping layer 3 is made of polyester tape or non-woven fabric. Polyester tape, with its high mechanical strength and excellent dimensional stability, can form a dense structural fixing layer with an ultra-thin thickness of 0.05~0.1mm, effectively locking the irregular cable core formed by the twisting of the core optical unit 1 and two 1.1~1.3mm power lines 2, preventing structural loosening during subsequent processing and vehicle vibration environments. Non-woven fabric, with its excellent softness and filling properties, can perfectly conform to the irregular surface of the twisted cable core, effectively filling the tiny gaps between units and forming a smooth transition layer. This reduces bending resistance when the cable is routed in narrow passages such as vehicle doors. Its porous structure also provides a unique buffering effect, absorbing some mechanical stress in vehicle vibration and high-frequency dynamic bending scenarios, reducing the risk of 100° micro-bending loss in the internal optical fiber, and extending the cable's service life. In practical applications, the preferred choice is selected based on specific circumstances.

[0028] In this application, the outer sheath 4 has an outer diameter of 3-4 mm, and the outer sheath 4 is made of one of thermoplastic polyurethane, low-smoke halogen-free flame-retardant polyolefin, polyvinyl chloride, or ethylene-tetrafluoroethylene copolymer. The outer sheath 4, with its 3-4 mm outer diameter, works in conjunction with the core optical unit 1, aramid braided layer, two power lines 2, and wrapping layer 3 to strictly control the overall cable outer diameter below the critical value of 4.0 mm. Thermoplastic polyurethane, with its excellent elasticity and abrasion resistance, provides superior mechanical protection, making it particularly suitable for high-frequency dynamic bending scenarios such as car doors and electric seats. Its wide temperature range ensures flexibility under extreme climates, and its low coefficient of friction significantly reduces wiring resistance in narrow passages. Low-smoke halogen-free flame-retardant polyolefin is known for its excellent fire safety, does not produce toxic halogen gases, fully complies with automotive safety standards, and significantly improves occupant escape safety in emergencies. Simultaneously, its low density effectively reduces cable weight. Ethylene-tetrafluoroethylene copolymer, with its excellent heat resistance and chemical stability, is particularly suitable for high-temperature areas such as engine compartments, and its extremely low dielectric constant ensures signal transmission quality. Polyvinyl chloride, on the other hand, offers an economical and practical solution for non-critical areas due to its superior processing performance and cost advantages. The appropriate material should be selected based on the specific application scenario.

[0029] Example 2 Reference Figure 1-3This invention provides a stranding method for a thin-diameter vehicle-mounted hybrid optical and electrical cable as described in any of Embodiment 1. In some other embodiments, the optical and electrical hybrid cable using fixed-pitch stranding experiences stress concentration at a fixed position during repeated bending, which can easily lead to a sharp increase in micro-bending loss of the optical fiber 100 and fatigue fracture of the conductor 20, failing to meet the service life requirement of over 10 years for vehicle-mounted equipment. Furthermore, the optical and electrical hybrid cable in this application adopts a thin-diameter design, with the core optical unit 1 having no sheath. The internal optical fiber 100 relies solely on the coating layer, tight-buffered layer 101, and fiber braided layer 11 for direct contact, without a sheath buffer medium. If conventional fixed-pitch SZ stranding is used, uneven stress transmission will occur during the stranding process. The fixed-pitch stranding helical structure concentrates external forces, such as cabling tension and laying bending forces, onto the reversing point area. The fiber braided layer 11 will directly transmit local stress to the internal fiber 100 bundle, causing micro-bending of the fiber 100 in this area. At the same time, the fixed reversing point is repeatedly subjected to alternating stress, which will cause local friction and wear between the fiber braided layer 11 and the coating layer, accelerating the formation of micro-cracks in the coating layer. During temperature cycling, from -40℃ to 125℃, the thermal expansion coefficients of the fiber braided layer 11 and the fiber 100 materials differ significantly. The "rigid stress concentration zone" of the fixed-pitch stranding will exacerbate the deformation stress caused by this difference, leading to increased attenuation loss of the fiber 100 and affecting transmission stability.

[0030] Therefore, the twisting method used in this application includes: S1: Based on the real-time axial position of the cable core, the reference pitch value, the pitch change amplitude, and the pitch change period, obtain the instantaneous twisted pitch of the cable core at the current axial position. This can be expressed by the formula: L(z) = L0 + A × sin(2πz / P), where L(z) represents the instantaneous twisted pitch, L0 represents the reference pitch value, A represents the pitch change amplitude, Z represents the real-time axial position of the cable core, and P represents the pitch change period.

[0031] Specifically, the real-time axial position of the cable core is obtained in real time by an encoder to measure the production length coordinates of the cable body. The reference pitch value is first obtained by taking the equivalent diameter of the cable core based on the outer diameter of the core optical unit 1 or the outer diameter of the power line 2, and the twisting gap correction value. Then, the reference pitch value is obtained based on the equivalent diameter of the cable core and the twisting coefficient. The equivalent diameter of the cable core is rounded to an integer, and the twisting coefficient ranges from 12 to 20. It is expressed by the formula: L0 = D × K, where D represents the equivalent diameter and K represents the twisting coefficient. For small-diameter, high-dynamic cables, a smaller K value is preferred to obtain better flexibility. D ≈ 2 times the diameter of the core optical unit 1 or the power line 2 and the twisting gap correction value is 0.1 to 0.3 mm. The ratio of the pitch change amplitude to the reference pitch value ranges from 0.1 to 0.25, and the pitch change period ranges from 1.0 to 3.0 m, preferably 1.5 m to 2.5 m.

[0032] This application illustrates, through an example, the use of an SZ stranding machine with digital motion control. The pitch function L(z) is input into the control system, and the equipment dynamically adjusts the ratio of traction speed to stranding head speed based on the real-time production length Z of the cable, precisely achieving variable pitch stranding. The diameters of the core optical unit 1 and the power line 2 are both 1.2 mm. The preferred stranding gap correction value is 0.3 mm, D = 2 × 1.2 mm + 0.3 mm = 2.7 mm, the stranding coefficient K is selected as 14, L0 is rounded to 40 mm, and A = 0.2 × L0 is taken as 8 mm. This is a commonly used ratio that produces significant effects without compromising structural stability. The period P is set to 1200 mm, a value that matches the periodic scale of stress dispersion with the typical length of the vehicle-mounted wiring harness, ensuring that the cable completes at least one complete stress redistribution cycle in most wiring sections, thereby maximizing fatigue resistance. Simultaneously, this pitch change period is much larger than the reference pitch value, ensuring the smoothness of the change process and the feasibility of the process. Then L(z) = 40 + 8 × sin(2πz / 1200). Since the range of the sine function sin(2πz / 1200) is [-1, +1], L(z) has a range of 40. The thickness varies continuously between 8=32mm and 40+8=48mm.

[0033] S2: Once L(z) is calculated in real time, the real-time rotational angular velocity of the twisting head is obtained based on the instantaneous twisting pitch and constant traction speed, expressed by the formula: ω=v / L(z), where ω represents the real-time rotational angular velocity of the twisting head and v represents the constant traction speed. Under the premise of keeping the traction speed v basically constant, or adjusting it according to a certain strategy, the rotational speed ω of the twisting head is dynamically adjusted so that the actual v / ω value matches the target L(z) in real time.

[0034] S3: Finally, based on the real-time rotational angular velocity of the stranding head, the stranding machine is used to complete the stranding of the core optical unit 1 and the power line 2.

[0035] This application enables the stranding pitch to vary continuously along the cable length in a sinusoidal pattern, thereby dispersing the alternating stress concentrated at a fixed reversal point in traditional fixed-pitch applications to the entire cycle length. Specifically, firstly, the real-time production length coordinate z of the cable is obtained via an encoder, and the instantaneous stranding pitch L(z) is calculated. Then, based on a constant traction speed v and the formula ω=v / L(z), the rotational angular velocity ω of the stranding head is calculated in real time. Finally, the rotational speed of the stranding head is dynamically adjusted through a digital motion control system, ensuring that the actual v / ω ratio precisely matches the target pitch function. This variable pitch design allows the reversal point of the stranding helix to continuously shift along the cable length, completely eliminating "stress hotspots" and effectively preventing the fiber braided layer 11 from directly transmitting localized stress to the internal optical fiber 100 under unsheathed buffer conditions. In summary, the continuous periodic symmetrical gradually changing pitch SZ stranding method effectively eliminates the stress concentration points formed by the conventional SZ stranding method by periodically changing the stranding pitch. The smooth and gradual change of the pitch makes the SZ stranding reversal points diffusely distributed along the length of the optical unit. The external force that was originally concentrated in a fixed area is evenly distributed to the entire fiber braid layer 11 and the fiber 100 bundle. At the same time, the "diffusion" of the reversal points avoids repeated friction of the aramid filaments on the same area of ​​the fiber 100, reducing the microbending loss of the fiber 100.

[0036] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not 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 this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" 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; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0037] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. 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 this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A thin-diameter vehicle-mounted hybrid optical-electric cable, characterized in that, It includes: Core optical unit (1), which includes tight-buffered optical fiber (10) and fiber braided layer (11) wrapped around the tight-buffered optical fiber (10). Power line (2), which is provided with several, and several power lines (2) are twisted together with the core optical unit (1) to form a cable core; A wrapping layer (3) covers the cable core; The outer sheath (4) is wrapped around the strap layer (3).

2. The thin-diameter vehicle-mounted hybrid optical and electrical cable as described in claim 1, characterized in that: The tight-buffered optical fiber (10) includes an optical fiber (100) and a tight-buffered layer (101) covering the optical fiber (100), and the outer diameter of the tight-buffered optical fiber (10) is 0.35~0.95mm.

3. The thin-diameter vehicle-mounted hybrid optical and electrical cable as described in claim 1, characterized in that: The fiber braided layer (11) includes an aramid braided layer with an outer diameter of 0.7~1.3 mm.

4. The thin-diameter vehicle-mounted hybrid optical and electrical cable as described in claim 1, characterized in that: The power cord (2) includes a conductor (20) and an insulating layer (21) covering the conductor (20), and the outer diameter of the power cord (2) is 1.1~1.3mm.

5. A thin-diameter vehicle-mounted hybrid optical and electrical cable as described in claim 4, characterized in that: The insulating layer (21) is a cross-linked low-smoke halogen-free flame-retardant polyolefin material.

6. A thin-diameter vehicle-mounted hybrid optical and electrical cable as described in claim 1, characterized in that: The wrapping layer (3) is made of polyester tape or non-woven fabric.

7. A thin-diameter vehicle-mounted hybrid optical and electrical cable as described in claim 1, characterized in that, The outer diameter of the outer sheath (4) is 3~4mm, and the outer sheath (4) is made of one of thermoplastic polyurethane, low smoke halogen-free flame retardant polyolefin, polyvinyl chloride or ethylene-tetrafluoroethylene copolymer.

8. A stranding method for a thin-diameter vehicle-mounted optical-electric hybrid cable as described in any one of claims 1-7, characterized in that, It includes: Based on the real-time axial position of the cable core, the reference pitch value, the pitch change amplitude, and the pitch change period, the instantaneous twisting pitch of the cable core at the current axial position is obtained. Based on instantaneous twisting pitch and constant traction speed, the real-time rotational angular velocity of the twisting head is obtained; Based on the real-time rotational angular velocity of the stranding head, the stranding machine is used to complete the stranding of the core optical unit (1) and the power line (2).

9. The stranding method for a thin-diameter vehicle-mounted optical-electric hybrid cable as described in claim 8, characterized in that: Based on the outer diameter of the core optical unit (1) or the outer diameter of the power line (2), and the twisting gap correction value, the equivalent diameter of the cable core is obtained. The reference pitch value is obtained based on the equivalent diameter of the cable core and the stranding factor. The equivalent diameter of the cable core is an integer, and the stranding coefficient ranges from 12 to 20.

10. The stranding method for a thin-diameter vehicle-mounted optical-electric hybrid cable as described in claim 8, characterized in that: The ratio of the pitch change amplitude to the reference pitch value ranges from 0.1 to 0.25, and the pitch change period ranges from 1.0 to 3.0 m.

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