Air-blowing optical cable

Abstract

The utility model discloses an air-blowing optical cable, which comprises a cable core and an outer sheath coated outside the cable core, the cable core comprises a plurality of optical fibers and a bonding part for bonding the plurality of optical fibers at intervals in the axial direction, a raised line is arranged on the outer wall of the outer sheath, the height direction of the raised line extends towards the outer side along the radial direction of the optical cable, and the height direction of the raised line extends towards the outer side along the radial direction of the optical cable. The length direction of the raised line extends along the length direction of the air-blowing optical cable, and the height of the raised line is set to be 0.05-0.4 mm. The outer side of the outer sheath is provided with the protruding strips, thereby reducing the friction force between the optical cable and an outer pipeline during laying, enabling the cable laying to be more efficient during air-blowing laying, reducing the damage, achieving the long-distance cable laying, and reducing the labor intensity. And meanwhile, the height of the raised line is set to be 0.05-0.4 mm, so that the raised line can pass through a sizing die and cannot be scratched with the sizing die, and the raised line is changed into a groove after subsequent vacuum negative-pressure vacuumizing, so that the original optical cable structure is changed.

Description

Technical Field

[0001] This utility model relates to optical cable products, and more particularly to an air-blown optical cable. Background Technology

[0002] Air-blown fiber optic cable is a technology that uses compressed gas (usually air) to propel optical fibers or electrical cables through a conduit. This technology is primarily used for fiber optic or cable cabling, especially in locations where manual laying is difficult, such as long-distance underground ducts. Air-blown fiber optic cables offer advantages such as efficient cable laying, reduced damage, long-distance cable laying, reduced labor intensity, and high scalability, making them widely used in the telecommunications industry and other fields requiring long-distance cable laying, particularly in the construction of fiber optic networks.

[0003] However, in the existing technology, when the optical cable is blown into the external duct, the contact area between the outer sheath of the optical cable and the access duct is large, which greatly increases the friction and thus increases the difficulty of laying the air-blown optical cable.

[0004] After the sheath is extruded outside the optical cable core, the optical cable needs to be sized in a sizing mold. Therefore, it is necessary to ensure that the production process of the optical cable meets the requirements. Utility Model Content

[0005] This invention overcomes the shortcomings of the prior art and provides an air-blown optical cable.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an air-blown optical cable, comprising a cable core and an outer sheath covering the cable core, wherein the cable core comprises a plurality of optical fibers and an adhesive portion for intermittently bonding the plurality of optical fibers in the axial direction, and a protruding strip is provided on the outer wall of the outer sheath, wherein the height direction of the protruding strip extends outward along the radial direction of the optical cable, the length direction of the protruding strip extends along the length direction of the air-blown optical cable, and the protruding strip is spirally wrapped around the surface of the outer sheath, wherein the height of the protruding strip is set to 0.05-0.4mm.

[0007] More specifically, on any radial surface of the air-blown optical cable, the cross-section of the protrusion is set to be arc-shaped.

[0008] More specifically, on any radial surface of the air-blown optical cable, the cross-section of the protrusion is set to trapezoidal, and the closer to the outer sheath, the larger the cross-sectional size of the protrusion.

[0009] More specifically, the pitch of the spiral ribs is set to be less than or equal to 0.5m.

[0010] More specifically, the pitch of the spiral ribs is set to 0.01-0.5m.

[0011] More specifically, any adhesive portion on any optical fiber is a first reference adhesive portion, an adjacent adhesive portion on an optical fiber adjacent to the first reference adhesive portion is a second reference adhesive portion, and an adjacent adhesive portion on an optical fiber adjacent to the second reference adhesive portion is a third reference adhesive portion, and the first reference adhesive portion, the second reference adhesive portion, and the third reference adhesive portion are on the same straight line.

[0012] More specifically, two colored wires are provided outside the plurality of optical fibers, and the two colored wires are twisted in opposite directions to bundle the plurality of optical fibers into an optical fiber bundle.

[0013] More specifically, the colored thread is made of polyester yarn, and the pitch of the colored thread is less than 7cm.

[0014] More specifically, water-blocking yarn is provided inside the optical fiber bundle.

[0015] More specifically, the water-blocking yarn is configured as a high-expansion water-blocking yarn.

[0016] An air-blown optical cable solves the defects existing in the background technology. The present invention has the following beneficial effects: a raised strip is provided on the outer side of the outer sheath to reduce the friction between the optical cable and the outer pipe during installation, so that the air-blown installation can be more efficient, reduce damage, allow for long-distance installation, and reduce labor intensity; at the same time, the height of the raised strip is set to 0.05-0.4mm to ensure that it can pass through the sizing die without scratching the sizing die. After subsequent vacuuming, the raised strip becomes a groove, changing the original raised strip structure. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0018] Figure 1 This is a cross-sectional view of the optical cable with the protrusions of this utility model set in an arc shape, cut along the radial direction;

[0019] Figure 2 This is a cross-sectional view of the optical cable with the protrusions of this utility model set as trapezoidal.

[0020] Figure 3 This is a schematic diagram of the structure of the present invention, showing the combination of several optical fibers and adhesive parts to form an optical fiber ribbon;

[0021] Figure 4 This is a schematic diagram of the structure of the present invention, in which an optical fiber ribbon and a water-blocking yarn are bound together with colored thread to form an optical fiber bundle;

[0022] Figure 5 This is a schematic cross-sectional view of the sizing die of this utility model along the axial direction.

[0023] Figure 6This is a radial cross-sectional view of the sizing die of this utility model.

[0024] In the diagram: 1. Cable core; 11. Optical fiber; 12. Adhesive joint; 13. Water-blocking yarn; 14. Colored thread; 15. Optical fiber ribbon; 16. Optical fiber bundle; 2. Water-blocking tape; 3. Outer sheath; 4. Reinforcing member; 5. Raised strip; 6. Sizing mold; 61. Pressure hole. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this utility model. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0026] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," 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 utility model 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. Therefore, they should not be construed as limiting the scope of protection of this utility model. The embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] It should be understood that the accompanying drawings are for illustrative purposes only.

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0029] A type of air-blown optical cable, such as Figures 1-4 As shown, it includes a cable core 1 and an outer sheath 3 covering the cable core 1.

[0030] like Figure 3As shown, the cable core 1 includes a plurality of optical fibers 11 and adhesive portions 12 that intermittently bond the plurality of optical fibers 11 in the axial direction. Any adhesive portion 12 on any optical fiber 11 is a first reference adhesive portion, an adjacent adhesive portion 12 on an optical fiber 11 adjacent to the first reference adhesive portion is a second reference adhesive portion, and an adjacent adhesive portion 12 on an optical fiber 11 adjacent to the second reference adhesive portion is a third reference adhesive portion. The first reference adhesive portion, the second reference adhesive portion, and the third reference adhesive portion are on the same straight line. For example, three optical fibers 11 are arranged in sequence as the first optical fiber, the second optical fiber, and the third optical fiber. Each optical fiber 11 has three adhesive portions 12, arranged in sequence as the first adhesive portion, the second adhesive portion, and the third adhesive portion. The first adhesive portion on the second optical fiber is defined as the first reference adhesive portion. The optical fibers adjacent to the first reference adhesive portion are the first optical fiber and the third optical fiber. The adhesive portions adjacent to the first reference adhesive portion are the first adhesive portions of the first optical fiber and the first adhesive portions of the third optical fiber. The two first adhesive portions are the second reference adhesive portions. If there is a fourth optical fiber, the optical fiber adjacent to the second reference adhesive portion is the fourth optical fiber. The first adhesive portion adjacent to the second reference adhesive portion is the first adhesive portion of the fourth optical fiber. This first adhesive portion is the third reference adhesive portion. The first reference adhesive portion, the second reference adhesive portion, and the third reference adhesive portion are on the same straight line, that is, the first adhesive portions of the first optical fiber, the second optical fiber, the third optical fiber, and the fourth optical fiber are on the same straight line.

[0031] The high-precision dispensing technology used in the fiber optic strip 11 ensures that the connecting lines of adjacent adhesive portions 12 of any adjacent fiber optic strip 11 are on the same straight line. In this design, the adhesive portions 12 are set as adhesive dots with a deviation of less than 0.1mm between them. This high precision helps ensure that the cross-sectional differences between several fibers 11 after cutting are minimal during the overall fusion splicing process of the fiber optic strip 11, maximizing the stability of the fusion splicing performance and reducing fusion loss.

[0032] In this scheme, the bare optical fiber size is set between 230μm and 240μm. After the optical fiber 11 is colored, the size of the optical fiber 11 is between 235μm and 245μm. Then, a layer of resin is coated on the surface of the optical fiber 11, and the size of the optical fiber 11 after coating with resin is between 240μm and 250μm.

[0033] The adhesive length of fiber 11, D2, is 20±5mm, and the adhesive distance of fiber 11, D3, is 40±5mm. The tilted dimension, D4, is exactly D4 = D2 * (number of fibers 11 - 1). The overall width of the fiber bundle 16, D1, is equal to the resin-coated dimension of fiber 11 * N + (40~60μm), where 40~60μm is a correction factor, representing the tiny gaps directly existing in fiber 11, providing higher mobility and resistance to external forces. Compared to fiber ribbons 15 bonded with traditional adhesive dots, this method achieves the same strength with smaller adhesive dots; if the same dot size is used, even greater strength can be obtained.

[0034] The fiber optic ribbon 15, employing a dispensing structure, ensures a tight bond between the optical fibers 11 with minimal adhesive usage. Traditional fiber optic ribbons 15, using full resin coating, suffer from overall structural curing, leading to breakage during winding and thus occupying space within the optical cable. The fiber optic ribbon 15 disclosed in this solution can be wound into a single strand of optical fibers 11 or twisted in less than one revolution, significantly enhancing its flexibility, drastically reducing the space required, and providing a smaller bending radius.

[0035] like Figure 4 As shown, two colored wires 14 are arranged around several optical fibers 11. The two colored wires 14 are twisted in opposite directions to bundle the optical fibers 11 into a bundle. The optical fibers 11 are bonded together to form an optical fiber ribbon 15. The two colored wires 14 can bundle only one optical fiber ribbon 15 or multiple optical fiber ribbons 15. One or more optical fiber ribbons 15 and a water-blocking yarn are combined and wound by the two colored wires to form an optical fiber bundle 16. A water-blocking yarn 13 is arranged inside the optical fiber bundle 16. The water-blocking yarn 13 is made of high-expansion water-blocking yarn. The colored wires 14 bundle one or more optical fiber ribbons 15 and a water-blocking yarn 13 to form an optical fiber bundle 16. Several optical fiber bundles 16 are twisted into a cable core 1. Prepare one or more optical fiber ribbons 15 and a high-expansion water-blocking yarn, and then prepare two colored wires 14. Wrap one or more optical fiber ribbons 15 and a water-blocking yarn 13 by twisting in opposite directions. The color thread 14 is made of 111D polyester yarn, which can be designed in different colors as required to facilitate the differentiation of different fiber bundles 16. The fiber ribbons 15 within any bundle can be distinguished by inkjet markings. Setting the pitch of the color thread 14 winding to less than 7cm allows for better direct differentiation of the fiber bundles 16. Traditionally, fiber bundles 16 often only have surface markings on the fiber ribbons 15. However, when inkjet marking is used as the primary identification method, it becomes difficult to quickly distinguish individual fiber bundles 16 as the core count increases. The different colored yarns in this solution allow construction personnel to quickly separate different fibers based on the color thread 14, significantly improving the splicing efficiency of ultra-high core count fiber bundles 16.

[0036] like Figure 1, Figure 2 As shown, to reduce friction during air-blowing installation of the optical cable into the external duct, a raised strip 5 is provided on the outer wall of the outer sheath 3. The height of the raised strip 5 extends radially outward along the optical cable, and the length of the raised strip 5 extends along the length of the air-blown optical cable. The height of the raised strip 5 is set to 0.05-0.4 mm, and the height of the raised strip 5 is the distance from the outer sheath 3 to the highest point of the raised strip 5. To ensure that the optical cable can be air-blown installed when entering the external duct, the raised strip 5 is spirally wrapped around the surface of the outer sheath. The pitch of the spiral raised strip 5 is set to be less than or equal to 0.5 m. When the pitch is greater than 0.5 m, the efficiency of air-blowing installation is poor. Furthermore, when the pitch of the spiral raised strip 5 is set to 0.01-0.5 m, there is only one raised strip 5 on any radial surface of the optical cable, resulting in better air-blowing effect.

[0037] After the outer sheath 3 and the protrusion 5 are extruded, they need to be sized by the sizing mold 6. The sizing mold 6 must have an inner diameter 0.6-0.8 mm larger than the outer diameter of the air-blown optical cable to ensure proper sizing. If the height of the protrusion 5 is less than 0.05 mm, the protrusion 5 will be flattened by the vacuum pressure when passing through the sizing mold 6, resulting in the absence of the protrusion 5 and thus failing to reduce friction. If the height of the protrusion 5 exceeds 0.4 mm, the sizing mold 6 will scrape against the protrusion 5, causing it to become a groove after being vacuumed, altering its original structure and failing to reduce friction. Therefore, to reduce friction, protrusions 5 can be provided on the outer sheath 3. However, to meet the requirements of the subsequent sizing process, the height of the protrusion 5 needs to be maintained between 0.05-0.4 mm.

[0038]

[0039] On any radial surface of the air-blown optical cable, the protrusion 5 is arc-shaped or trapezoidal. When the cross-sectional shape of the protrusion 5 is set to trapezoidal, the size of the protrusion 5 is larger the closer it is to the outer sheath 3, ensuring the air-blowing effect. The shape of the protrusion 5 is often arc-shaped or trapezoidal, but it can also be set to other shapes, as long as it can pass through the sizing die 6. However, setting it to other shapes may cause deformation and other problems. For example, a triangle, due to its pointed head, will cause scraping and indentation after entering the sizing die 6. If it is a square or rectangle, the angles on both sides are 90°, which is very easy to cause scraping, eventually causing the protrusion 5 to be flattened. At the same time, when the optical cable is laid to the external duct, the air-blowing effect is best when the shape of the protrusion 5 is arc-shaped or trapezoidal.

[0040]

[0041] The height of the ridge is the length of the line segment connecting the highest point of the ridge to the surface of the outer sheath and perpendicular to the tangent of the outer sheath surface; the width of the ridge is the length of the line segment connecting the two ends of the widest part of the bottom edge of the ridge.

[0042] α = a : b;

[0043] 2.4≤α≤1;

[0044] Where a is the height of the convex strip; b is the width of the convex strip; and α is the ratio of the convex strip height to the convex strip width.

[0045] Furthermore, the ratio of the height of the convex strip to the width of the convex strip is 2.4:1 to 1:1.

[0046] When the ratio of the height to the width of the convex strip is less than 1:1, that is, when the height of the convex strip is less than or greater than the width of the convex strip, the gas friction environment is poor when the optical cable is laid to the external pipeline. When the ratio of the height to the width of the convex strip is greater than 2.4:1, it will lead to a decrease in the strength of the tip of the convex strip, which will not only reduce the yield rate, but also directly affect the gain effect that the convex strip can bring to the optical cable. Therefore, when the ratio of the height to the width of the convex strip is controlled between 1 and 2.4, it can be ensured that the height and width of the convex strip are within the same arc length, so as to obtain a better gas friction environment as much as possible. That is, when the central angle is the same, the higher the surface convexity, the larger the specific surface area, while ensuring the structural strength.

[0047] A manufacturing process for air-blown optical cables, such as Figures 5-6 As shown, including steps,

[0048] S1, fiber 11 is laid out, several fiber 11 are arranged along the axial direction, and the adhesive part 12 connects several fiber 11 to form fiber optic ribbon 15. Two colored threads 14 are wrapped around the outside of one or several fiber optic ribbons 15 and a water-blocking yarn 13 to form fiber optic bundle 16.

[0049] S2, several bundles of optical fibers 16 are twisted together to form a cable core 1. After the cable is formed, it enters the mold. A water-blocking strip 2 is provided on the outside of the cable core 1. The water-blocking strip 2 is set as an ultra-thin water-blocking strip 2.

[0050] S3, the motor drives the screw head to rotate, which in turn drives the mold core to rotate. The cable core 1 is extruded into the outer sheath 3 in the mold. The outer sheath 3 is set on the water-blocking tape layer. The protrusions 5 formed on the outer sheath 3 are spirally wound on the outer sheath 3. The height of the protrusions 5 is set to 0.05-0.4mm. A reinforcing member 4 is provided in the outer sheath 3. The reinforcing member 4 is evenly distributed circumferentially in the outer sheath 3.

[0051] S4, after the outer sheath 3 is cured, it enters the sizing mold 6 for vacuum sizing. The optical cable is sizing in the sizing mold 6 to ensure the roundness of the optical cable.

[0052] like Figure 5 , Figure 6 As shown, the sizing mold 6 is a device for sizing the optical cable after its fabrication. It is placed in water, and the cylinder of the sizing mold 6 is made of a vacuum copper tube. The extruded optical cable passes through the vacuum sizing copper tube to sizing the cable, ensuring its roundness. The overall length of the sizing mold 6 is set to 200-400mm. If the length of the sizing mold 6 is less than 200mm, the sizing effect cannot be achieved; if the length of the sizing mold 6 is greater than 400mm, the sizing will be too long, causing the optical cable to constantly scrape against the surface of the sizing mold 6, resulting in an unsatisfactory surface finish. The inner diameter of the sizing mold 6 is 0.6-0.8mm larger than the outer diameter of the air-blown optical cable to ensure accurate sizing.

[0053] After the cable core 1 is extruded with the outer sheath 3 and the convex strip 5, the temperature will be relatively high. Therefore, the optical cable needs to be cooled after entering the sizing mold 6. In the usual setting, the sizing mold 6 is placed in water, and the water exchanges heat with the sizing mold 6 to cool the optical cable. However, the cooling effect of the sizing mold 6 on the optical cable is limited because only the sizing mold 6 is in contact with the external water. Therefore, several pressure-drawing holes 61 are opened on the sizing mold 6. Water placed outside the sizing mold 6 enters the interior of the sizing mold 6 through the pressure-drawing holes 61 and comes into contact with the high-temperature optical cable to better cool the optical cable. At the same time, vacuum pressure can be drawn into the sizing mold 6. The size of the pressure-drawing holes 61 is set to 1.5 mm, and the coverage of the pressure-drawing holes 61 is greater than 50% of the sizing mold 6.

[0054] An air-blown optical cable features raised strips 5 on the outer side of the outer sheath 3. These strips reduce friction between the cable and the outer duct during installation, enabling more efficient cable laying, reducing damage, facilitating long-distance installation, and lowering labor intensity. The height of the raised strips 5 is set to 0.05-0.4mm to ensure they can pass through the sizing die without rubbing against it. After subsequent vacuum evacuation, the raised strips 5 become grooves, altering their original structure. The raised strips 5 are also designed in a spiral shape for better air-blown installation. Vacuum sizing within the sizing die 6 ensures the roundness of the optical cable.

[0055] Based on the preferred embodiments of this utility model described above, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

[0056] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0058] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. An air-blown optical cable, characterized in that: The cable includes a cable core (1) and an outer sheath (3) covering the cable core (1). The cable core (1) includes a plurality of optical fibers (11) and an adhesive portion (12) that intermittently bonds the plurality of optical fibers (11) in the axial direction. A protruding strip (5) is provided on the outer wall of the outer sheath (3). The height direction of the protruding strip (5) extends outward along the radial direction of the optical cable, and the length direction of the protruding strip (5) extends along the length direction of the air-blown optical cable. The protruding strip (5) is spirally wrapped around the surface of the outer sheath (3). The height of the protruding strip (5) is set to 0.05-0.4mm.

2. The air-blown optical cable according to claim 1, characterized in that: On any radial surface of the air-blown optical cable, the cross section of the protrusion (5) is set to be arc-shaped.

3. The air-blown optical cable according to claim 1, characterized in that: On any radial surface of the air-blown optical cable, the cross-section of the protrusion (5) is set to trapezoidal, and the closer it is to the outer sheath (3), the larger the cross-sectional size of the protrusion (5).

4. The air-blown optical cable according to claim 1, characterized in that: The pitch of the spiral rib (5) is set to be less than or equal to 0.5m.

5. The air-blown optical cable according to claim 4, characterized in that: The pitch of the spiral rib (5) is set to 0.01-0.5m.

6. The air-blown optical cable according to claim 1, characterized in that: Any adhesive portion on any optical fiber is a first reference adhesive portion, an adjacent adhesive portion on an optical fiber adjacent to the first reference adhesive portion is a second reference adhesive portion, and an adjacent adhesive portion on an optical fiber adjacent to the second reference adhesive portion is a third reference adhesive portion. The first reference adhesive portion, the second reference adhesive portion, and the third reference adhesive portion are on the same straight line.

7. The air-blown optical cable according to claim 1, characterized in that: Two colored wires (14) are provided outside the plurality of optical fibers (11), and the two colored wires (14) are wrapped in opposite directions to bundle the plurality of optical fibers (11) into an optical fiber bundle (16).

8. The air-blown optical cable according to claim 7, characterized in that: The colored thread (14) is made of polyester yarn, and the pitch of the colored thread (14) is less than 7cm.

9. The air-blown optical cable according to claim 7, characterized in that: Water-blocking yarn (13) is provided inside the optical fiber bundle (16).

10. The air-blown optical cable according to claim 9, characterized in that: The water-blocking yarn (13) is configured as a high-expansion water-blocking yarn.

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