Air blown microcable

Abstract

The application relates to a gas-blowing micro-cable, belonging to the technical field of optical cables, which comprises an outer sheath with an installation cavity inside; a plurality of optical units are arranged in the installation cavity; a plurality of rigid reinforcing elements are arranged between the inner wall of the installation cavity and the outer wall of the optical units; and the optical units and the rigid reinforcing elements are twisted to form a cable core. The application cancels the central reinforcing element, avoids the waste of the outer diameter, replaces the sleeve with the rigid reinforcing element to provide rigidity, significantly improves the overall rigidity, and realizes the synergistic optimization of the minimization of the outer diameter and the maximization of the rigidity.

Description

Technical Field

[0001] This application relates to the field of optical cable technology, and in particular to an air-blown microcable. Background Technology

[0002] The increasing demand for high-density optical cables is driven by both the current demand for network communication and the strain on urban pipeline resources. Air-blown micro-cables, a typical type of high-density optical cable, are widely used in FTTH construction due to their small outer diameter and air-blown installation characteristics. Specifically, high-pressure airflow is used to blow the micro-optical cable into pre-laid micro-ducts. Compared to traditional optical cable pulling or direct burial technologies, it offers significant advantages such as high construction efficiency, minimal environmental impact, flexible initial investment, and convenient network expansion and upgrades.

[0003] Currently, the two most common types of air-blown microcables in the industry can be broadly categorized into two types based on their structure. One type features a stranded structure with a central reinforcing member. Micro-tubes are tightly arranged around the central reinforcing member, with a thin-walled sheath extruded on top. Due to the stranding method, this type of cable can achieve a larger core count. Its tensile strength and rigidity are generally provided by the central reinforcing member, resulting in excellent air-blown performance. It is primarily used for air-blown cabling in trunk networks, with the largest reported core count being 864 cores. The other type is a central tube structure, where the tube contains rigid plastic material and requires additional auxiliary reinforcing yarns. A thin-walled sheath is extruded on top. This type of cable has a very small outer diameter, with rigidity provided by the tube. It is mainly used for branching in drop sections, with the largest reported core count being 36 cores.

[0004] While the two typical types of air-blown microcables mentioned above are widely used, stranded optical cables with a central reinforcing member cannot achieve a smaller outer diameter for low-core-count cables due to the presence of the central reinforcing member, resulting in wasted pipeline resources in air-blowing applications. For air-blown microcables with a central tube structure, the lack of a central reinforcing member and reliance solely on the sheath for rigidity places higher demands on production and processes. Furthermore, the limited core count and insufficient rigidity make the cable performance highly sensitive to environmental conditions, thus limiting the air-blowing distance. Therefore, the application scenarios for these two typical types of air-blown microcables are limited. Summary of the Invention

[0005] This application provides an air-blown microcable to address the problem that two typical air-blown microcables in related technologies cannot simultaneously meet the requirements of rigidity and small outer diameter, thus limiting their application scenarios.

[0006] In a first aspect, an air-blown microcable is provided, comprising: an outer sheath having an inner mounting cavity; multiple optical units disposed within the mounting cavity; multiple rigid reinforcement elements disposed between the inner wall of the mounting cavity and the outer wall of the optical units; and the optical units and the rigid reinforcement elements being twisted together to form a cable core.

[0007] In some embodiments, the rigid reinforcement element includes a glass fiber reinforcement rod located between the inner wall of the mounting cavity and the outer wall of the optical unit, and twisted with the optical unit to form a cable core.

[0008] In some embodiments, the outer diameter of the glass fiber reinforced rod is set to 0.5~1.5mm.

[0009] In some embodiments, the optical unit includes a sleeve and multiple optical fibers, the multiple optical fibers being fitted inside the sleeve, and the sleeve being filled with a water-blocking element.

[0010] In some embodiments, the outer diameter of the optical unit is set to 0.9~1.7mm.

[0011] In some embodiments, the water-blocking element comprises a grease that is filled between the plurality of optical fibers.

[0012] In some embodiments, the cable core is wrapped with water-blocking yarn.

[0013] In some embodiments, the optical unit and the rigid reinforcement element are twisted together to form a gap, the gap being filled with a plastic element.

[0014] In some embodiments, at least one tear cord is provided between the cable core and the outer sheath.

[0015] In some embodiments, the wall thickness of the outer sheath is set to 0.3~0.7mm.

[0016] The beneficial effects of the technical solution provided in this application include: This application provides an air-blown microcable. Since the optical unit and the rigid reinforcement element are twisted together to form a compact cable core, the outer diameter is not wasted by eliminating the central reinforcement element. At the same time, the rigid reinforcement element replaces the sleeve to provide rigidity, which significantly improves the overall stiffness and achieves synergistic optimization of minimizing the outer diameter and maximizing the stiffness. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the first type of air-blown microcable structure provided in the embodiments of this application; Figure 2 This is a schematic diagram of a second type of air-blown microcable structure provided in an embodiment of this application.

[0019] In the diagram: 1. Outer sheath; 2. Mounting cavity; 3. Optical unit; 30. Sleeve; 31. Optical fiber; 4. Rigid reinforcing element; 5. Water-blocking yarn; 6. Water-blocking element; 7. Tear rope; 8. Plastic element. Detailed Implementation

[0020] 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.

[0021] This application provides an air-blown microcable that addresses the limitation in application scenarios caused by the inability of two typical air-blown microcable types in related technologies to simultaneously meet the requirements of rigidity and small outer diameter. The two typical air-blown microcable types are a stranded structure with a central reinforcement and a central tube structure.

[0022] Reference Figure 1-2 An air-blown microcable includes an outer sheath 1, optical units 3, and rigid reinforcing elements 4. The outer sheath 1 has a mounting cavity 2 and is made of polyethylene material. The wall thickness of the outer sheath 1 is set to 0.3~0.7mm, preferably 0.5mm. Multiple optical units 3 are provided and are disposed within the mounting cavity 2. Specifically, the number of optical units 3 is determined according to different product types. In this application embodiment, the first air-blown microcable includes two optical units 3, and the second air-blown microcable includes four optical units 3. Furthermore, multiple rigid reinforcing elements 4 are also provided, their number specifically adapted to the number of optical units 3. That is, the first air-blown microcable includes two rigid reinforcing elements 4, and the second air-blown microcable includes four rigid reinforcing elements 4. The multiple rigid reinforcing elements 4 are arranged between the inner wall of the mounting cavity 2 and the outer wall of the optical units 3. The optical units 3 and rigid reinforcing elements 4 are twisted to form a cable core, specifically combined in an SZ twisting manner, with the twisting pitch controlled at 150mm±10mm.

[0023] In this application, the rigid reinforcing element 4 is precisely arranged between the inner wall of the mounting cavity 2 and the outer wall of the optical unit 3 in a number that matches the optical unit 3, and is twisted with the optical unit 3 to form a cable core, directly providing rigid support. This overcomes the problems of high environmental sensitivity and limited air blowing distance caused by insufficient rigidity in the central tube structure, thus ensuring excellent rigidity and air blowing performance while achieving a small outer diameter, thereby adapting to the needs of more application scenarios. Furthermore, the outer sheath 1 is made of polyethylene material to ensure that the outer sheath 1 is flexible, durable, and environmentally adaptable. Combined with the ultra-thin wall thickness design of 0.3~0.7mm, the outer diameter is further significantly reduced.

[0024] In this application, a water-blocking yarn 5 is also wrapped around the cable core. The water-blocking yarn 5 wrapped around the cable core effectively prevents moisture intrusion, significantly improving the reliability and stability of the optical cable in humid or high-humidity environments.

[0025] In addition, at least one tear cord 7 is provided between the cable core and the outer sheath 1. The material can be polyester, aramid, or other suitable materials. The tear cord 7 provides a convenient stripping path for the outer sheath 1, which significantly simplifies the installation and maintenance operations after air-blown cabling and avoids the risk of damage to the optical fiber 31 due to the difficulty in stripping the outer sheath 1.

[0026] In this application, the rigid reinforcing element 4 includes a glass fiber reinforcing rod, which is located between the inner wall of the mounting cavity 2 and the outer wall of the optical unit 3, and is twisted with the optical unit 3 to form a cable core. The outer diameter of the glass fiber reinforcing rod is set to 0.5~1.5mm, preferably 1mm, and the modulus is greater than 50GPa. As a rigid reinforcing element 4, the glass fiber reinforcing rod has a high modulus to provide excellent stiffness and ensure that the optical cable is not easily deformed during air blowing. The preferred outer diameter of 1mm makes the glass fiber reinforcing rod compact. After the glass fiber reinforcing rod is twisted with the optical unit 3, the internal structure is optimized, achieving a small outer diameter while maintaining excellent rigidity, significantly improving air blowing performance and application adaptability. In this application, the optical unit 3 includes a sleeve 30 and multiple optical fibers 31. The multiple optical fibers 31 are fitted inside the sleeve 30, which is preferably made of PBT material. The number of optical fibers 31 is preferably 24, and the sleeve 30 is also filled with a water-blocking element 6, which includes grease, and is filled between the multiple optical fibers 31. The sleeve 30, made of PBT material, provides flexibility and chemical resistance. The standard number of optical fibers 31 ensures core count flexibility, while grease prevents moisture intrusion, improving the reliability of the optical cable in humid environments and preventing performance degradation. Therefore, the design of the optical unit 3 significantly enhances the environmental adaptability and reliability of the optical cable, avoiding performance fluctuations caused by moisture sensitivity. Simultaneously, in conjunction with the ultra-thin outer sheath 1 and the rigid reinforcement element 4, it ensures high rigidity and excellent air-blowing performance with a small outer diameter, completely solving the problems of pipe waste and limited air-blowing distance in the prior art.

[0027] In this application, the outer diameter of the optical unit 3 is set to 0.9~1.7mm, preferably 1.45mm. The outer dimensions of the optical unit 3 ensure that it can accommodate 24 optical fibers 31 and the grease-based water-blocking element 6, while precisely coordinating with the ultra-thin outer sheath 1 and the glass fiber reinforcing rod, so as to significantly reduce the overall outer diameter of the optical cable.

[0028] In this application, depending on the specific application, a gap is formed when the optical unit 3 and the rigid reinforcing element 4 are twisted together, and the gap is filled with a plastic element 8. Specifically, when the first type of air-blown microcable is used, there is generally no gap between the optical unit 3 and the rigid reinforcing element 4, so the issue of roundness does not need to be considered. However, when the second type of air-blown microcable is used, a gap is easily formed between the optical unit 3 and the rigid reinforcing element 4. Then, by filling the gap with a plastic element 8, the outer diameter of the optical unit 3 is greater than or equal to the outer diameter of the plastic element 8. The plastic element 8 is made of PP, PE, or other suitable materials. Filling the gap ensures the roundness of the cable core.

[0029] In this application, the first type of air-blown microcable is designed as a 48-core stranded microcable with an outer diameter of 3.9±0.2mm and a tensile strength exceeding 500N. Compared to traditional microcables with central reinforcement, its outer diameter is reduced by more than 25%, and with the support of two glass fiber reinforcing rods, it possesses sufficient rigidity and exhibits excellent air-blown performance. The second type of air-blown microcable is designed as a 96-core stranded microcable with an outer diameter of 4.5±0.2mm and a tensile strength exceeding 700N. Compared to traditional microcables with central reinforcement, its outer diameter is reduced by more than 15%, and with the support of four glass fiber reinforcing rods, it possesses sufficient rigidity and exhibits excellent air-blown performance.

[0030] 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.

[0031] 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.

[0032] 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. An air-blown microcable, characterized in that, It includes: Outer sheath (1), which has an installation cavity (2); Optical unit (3), which is provided in multiple units, and the multiple optical units (3) are disposed in the mounting cavity (2). The optical unit (3) includes a sleeve (30) and multiple optical fibers (31). The multiple optical fibers (31) are fitted in the sleeve (30), and the sleeve (30) is also filled with a water-blocking element (6). Rigid reinforcement element (4), which is provided in multiple units, and the multiple rigid reinforcement elements (4) are arranged between the inner wall of the mounting cavity (2) and the outer wall of the optical unit (3). The optical unit (3) and the rigid reinforcing element (4) are twisted together to form a cable core, and the optical unit (3) and the rigid reinforcing element (4) are twisted together to form a gap, the gap being filled with a plastic element (8).

2. The air-blown microcable as described in claim 1, characterized in that: The rigid reinforcing element (4) includes a glass fiber reinforcing rod, which is located between the inner wall of the mounting cavity (2) and the outer wall of the optical unit (3), and is twisted with the optical unit (3) to form a cable core.

3. The air-blown microcable as described in claim 2, characterized in that: The outer diameter of the glass fiber reinforced rod is set to 0.5~1.5mm.

4. The air-blown microcable as described in claim 1, characterized in that: The outer diameter of the optical unit (3) is set to 0.9~1.7mm.

5. The air-blown microcable as described in claim 1, characterized in that: The water-blocking element (6) includes a grease that is filled between the plurality of optical fibers (31).

6. The air-blown microcable as described in claim 1, characterized in that: The cable core is wrapped with water-blocking yarn (5).

7. The air-blown microcable as described in claim 1, characterized in that: At least one tear cord (7) is provided between the cable core and the outer sheath (1).

8. The air-blown microcable as described in claim 1, characterized in that: The wall thickness of the outer sheath (1) is set to 0.3~0.7mm.

Images