A direct buried optical cable in a full dielectric pipeline

Abstract

The present invention discloses a full-dielectric pipeline direct-buried optical cable, comprising an optical fiber, an inner sheath, a first glass fiber layer and a first sheath layer arranged in sequence from the inside to the outside, wherein a glass fiber rod is inserted into the first sheath layer along the extension direction. The glass fiber layer has certain bending resistance and lateral pressure resistance capabilities, and can better protect the internal optical fiber. The glass fiber rod is arranged in the first sheath layer, can be protected by the first sheath layer, and has a good tensile effect. By arranging the glass fiber layer and the glass fiber rod, it can have a good tensile, bending and lateral pressure resistance effect, and there is no need to use a metal armor layer, etc., and the metal content can be effectively reduced, or even the metal parts can be removed, thereby achieving a better lightning resistance effect. In summary, the full-dielectric pipeline direct-buried optical cable can effectively solve the problem that the current direct-buried optical cable has a poor lightning resistance effect.

Description

Technical Field

[0001] The present invention relates to the field of cable technology, and more specifically to an all-dielectric pipeline direct-buried optical cable. Background Art

[0002] The traditional pipeline direct buried optical cable is to put the fiber paste into a loose tube made of high modulus material, fill the loose tube with waterproof compound, and twist the loose tube or the filled rope component around the central metal reinforcement core to form a circular cable core. The gap in the cable core is filled with water-blocking filler, coated with plastic aluminum tape and then extruded with a polyethylene inner sheath. The outer double-sided plastic steel tape is longitudinally wrapped and then extruded into a polyethylene sheath to form a cable. This type of optical cable is suitable for long-distance communication and inter-office communication, especially for use as a transmission feeder in scenarios with high requirements for moisture resistance and rodent resistance. The disadvantages of this type of optical cable are large size, heavy weight, and the presence of metal reinforcements that cannot avoid lightning strikes.

[0003] In summary, how to effectively solve the problem that the current direct buried optical cable has poor lightning protection effect is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a full-dielectric pipeline direct-buried optical cable, which can effectively solve the problem that the current direct-buried optical cable has poor lightning protection effect.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A full-dielectric pipeline direct-buried optical cable comprises an optical fiber, an inner sheath, a first glass fiber layer and a first sheath layer which are arranged in sequence from the inside to the outside, wherein a glass fiber rod is inserted into the first sheath layer along an extending direction.

[0007] In the all-dielectric pipeline direct-buried optical cable, a glass fiber layer is provided, and a sheath layer is provided inside and outside the glass fiber layer, so that the sheath layer can buffer the impact of the glass fiber layer, and the glass fiber layer has certain bending resistance and lateral pressure resistance capabilities, which can better protect the internal optical fiber. The glass fiber rods are provided in the first sheath layer, can be protected by the first sheath layer, and have a good tensile effect. By providing a glass fiber layer and a glass fiber rod, it can have a good tensile, bending and lateral pressure resistance effect, and there is no need to use a metal armor layer, etc., and the metal content can be effectively reduced, or even the metal parts can be removed, thereby achieving a better lightning resistance effect. In summary, the all-dielectric pipeline direct-buried optical cable can effectively solve the problem that the current direct-buried optical cable has a poor lightning resistance effect.

[0008] Preferably, a second glass fiber layer and a second sheath layer are sequentially arranged on the outside of the first sheath layer from inside to outside.

[0009] Preferably, a plurality of optical fibers arranged in parallel are disposed inside the inner sheath, and a gap between the optical fibers and the inner sheath is filled with an aramid fiber central reinforcement.

[0010] Preferably, the first glass fiber layer is a glass fiber yarn layer, and the second glass fiber layer is the glass fiber tape layer.

[0011] Preferably, the optical fiber comprises a core and a tight cladding wrapped around the outside of the core.

[0012] Preferably, the first sheath layer is a polyolefin layer, and the second sheath layer includes a polyethylene sheath layer and a nylon sheath layer wrapped around the outside of the polyethylene sheath layer.

[0013] Preferably, a tear cord is provided between the first jacket layer and the first glass fiber layer, and a tear cord is provided between the second jacket layer and the second glass fiber layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of the cross-sectional structure of an all-dielectric pipeline direct-buried optical cable provided in an embodiment of the present invention.

[0016] The following are marked in the accompanying drawings:

[0017] Optical fiber 1, aramid fiber central reinforcement 2, inner sheath 3, glass fiber rod 4, glass fiber yarn layer 5, polyolefin layer 6, glass fiber tape layer 7, polyethylene sheath layer 8, nylon sheath layer 9, rip cord 10. DETAILED DESCRIPTION

[0018] The embodiment of the invention discloses a full-dielectric pipeline direct-buried optical cable, which effectively solves the problem that the current direct-buried optical cable has a poor lightning protection effect.

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1 , Figure 1 A schematic diagram of the cross-sectional structure of an all-dielectric pipeline direct-buried optical cable provided in an embodiment of the present invention.

[0021] In a specific embodiment, this embodiment provides an all-dielectric pipeline direct-buried optical cable. Specifically, the all-dielectric pipeline direct-buried optical cable includes an optical fiber 1, an inner sheath 3, a first glass fiber layer, a first sheath layer and a glass fiber rod 4.

[0022] The optical fiber 1 is located inside the inner sheath 3. Specifically, the inner sheath 3 is provided with one or more optical fibers 1, such as two to twenty-four optical fibers 1. The inner sheath 3 is preferably a one-time molded sheath.

[0023] The first glass fiber layer is sleeved on the outside of the inner sheath 3, and the first sheath layer is sleeved on the outside of the first glass fiber layer, so that from the inside to the outside, the optical fiber 1, the inner sheath 3, the first glass fiber layer and the first sheath layer are sequentially arranged. The first sheath layer and the inner sheath 3 are both sheath layers. The specific sheath layer, especially the sheath layer used on the optical cable, and the specific material molding method can be selected from the existing technology as needed, and will not be repeated here.

[0024] The first sheath layer is provided with glass fiber rods 4 along the extension direction, and generally, one glass fiber rod 4 is provided on each of the two sides away from each other, and of course, three or more glass fiber rods 4 may be evenly arranged along the circumference, wherein the glass fiber rods 4 play a certain role in strengthening the hardness. By providing the glass fiber rods 4 in the sheath layer, it can have a certain support when meeting the outdoor short-distance overhead use requirements of the optical cable, and provide a certain rigidity for the entire cable during the process of passing through the pipe.

[0025] In the all-dielectric pipeline direct-buried optical cable, a glass fiber layer is provided, and a sheath layer is provided inside and outside the glass fiber layer, so that the sheath layer can buffer the impact of the glass fiber layer, and the glass fiber layer has certain bending resistance and lateral pressure resistance capabilities, which can better protect the internal optical fiber. The glass fiber rod 4 is provided in the first sheath layer, can be protected by the first sheath layer, and has a good tensile effect. By providing the glass fiber layer and the glass fiber rod 4, it can have a good tensile, bending and lateral pressure resistance effect, and no longer needs to use a metal armor layer, etc., and can effectively reduce the content of metal parts, or even remove metal parts, so as to achieve a better lightning resistance effect. In summary, the all-dielectric pipeline direct-buried optical cable can effectively solve the problem that the current direct-buried optical cable has a poor lightning resistance effect.

[0026] Furthermore, in order to achieve a better lateral pressure resistance effect, it is preferred that a second glass fiber layer and a second sheath layer are sequentially arranged on the outside of the first sheath layer from the inside to the outside. In this case, the first sheath layer and the second sheath layer can provide impact protection for the second glass fiber layer between them. The first glass fiber layer and the second glass fiber layer are arranged at the same time to provide double insurance, and according to the stress characteristics, the glass fiber layer with the same cross-section area has better lateral pressure resistance and bending resistance when only one layer is arranged than when two layers are arranged. Arranging more layers means that more sheath layers need to be arranged, which will increase the cost.

[0027] Specifically, the first glass fiber layer can be a glass fiber yarn layer 5, and the second glass fiber layer can be the glass fiber tape layer 7, so that the thickness of the second glass fiber layer is significantly greater than that of the first glass fiber layer, so as to adapt to its own large diameter and avoid the overall diameter being too large. The glass fiber yarn layer 5 can refer to the molding method of the water-blocking yarn layer, and is generally wound to form the glass fiber yarn layer 5; the glass fiber tape layer 7 can refer to the molding method of the water-blocking tape layer, and is generally longitudinally wrapped to form the glass fiber tape layer 7. The first glass fiber layer is preferably a high-modulus glass fiber yarn layer 5, and the glass fiber yarn layer 5 is preferably a fluorine-free and boron-free high-strength glass fiber yarn layer, which provides higher reliability, longer service life, lower cost, excellent high temperature resistance and corrosion resistance: while maintaining high impact resistance and high fatigue resistance. The glass fiber layer plays a certain rat-proofing function when reinforced.

[0028] In order to achieve a better central reinforcement effect, it is preferred that a plurality of optical fibers 1 are arranged in parallel inside the inner sheath 3, and the gap between the optical fiber 1 and the inner sheath 3 is filled with an aramid fiber central reinforcement 2. The optical fiber 1 includes a core and a tight cladding wrapped around the outer side of the core. For example, four optical fibers 1 are arranged in two rows and two columns in a rectangular shape, and the above-mentioned aramid fiber central reinforcement is arranged between the four optical fibers 1 and between the optical fiber 1 and the outer inner sheath 3.

[0029] In order to provide better protection for the sheath layers, it is preferred that the first sheath layer is a polyolefin layer 6, and the second sheath layer includes a polyethylene sheath layer 8 and a nylon sheath layer 9 wrapped around the outside of the polyethylene sheath layer 8. Of course, sheath layers of other materials can also be used. The second sheath layer adopts a double sheath layer, which can make the advantages of the two sheath layers complement each other. In order to better break the sheath layer to expose the internal optical fiber 1, it is preferred that a tear rope 10 is provided between the first sheath layer and the first glass fiber layer, and a tear rope 10 is provided between the second sheath layer and the second glass fiber layer. The inner sheath 3 can be a low-smoke halogen-free polyolefin sheath. The combination of the polyethylene sheath layer 8 and the nylon sheath layer 9 can provide performance protection in the outdoor direct burial scene environment of the optical cable, and the entire cable meets the rat-proof performance. Nylon material has the characteristics of thermoplasticity, light weight, good toughness, chemical resistance and good durability, and is suitable for pipelines, direct burial and other scenes.

[0030] In another specific embodiment, this embodiment provides a lightweight all-dielectric pipe direct-buried optical cable. Specifically, the lightweight all-dielectric pipe direct-buried optical cable includes an optical fiber 1, an aramid fiber central reinforcement 2, an inner sheath 3, a glass fiber rod 4, a glass fiber yarn layer 5, a polyolefin layer 6 (LSZH), a glass fiber tape layer 7, a polyethylene sheath layer 8, a nylon sheath layer 9 and a tear rope 10.

[0031] The optical fiber 1 and the above-mentioned aramid fiber central reinforcement member 2 are both located in the inner sheath 3, wherein the optical fiber 1 is a tight-wrapped optical fiber, that is, it includes a fiber core and a tight cladding tightly wrapped around the outside of the fiber core. Generally, multiple optical fibers 1 are arranged in the inner sheath 3, and two to twenty-four optical fibers 1 can be arranged, such as four optical fibers 1, and the gap between the inner sheath 3 and the optical fiber 1 is filled with the aramid fiber central reinforcement member 2 to play a role in central reinforcement. The inner sheath 3 is preferably a one-time molded sheath layer.

[0032] On the outside of the inner sheath 3, there are arranged in order from the inside to the outside a glass fiber yarn layer 5, a polyolefin layer 6, a glass fiber tape layer 7, a polyethylene sheath layer 8 and a nylon sheath layer 9. The polyolefin 6 is penetrated with a glass fiber rod 4 along the extension direction, and a tear cord 10 is arranged between the glass fiber tape layer 7 and the polyethylene sheath layer 8 and / or between the polyolefin layer 6 and the glass fiber yarn layer 5. The inner sheath may be a low-smoke halogen-free polyolefin sheath.

[0033] Lightweight all-dielectric pipeline direct buried optical cable, in terms of structural type, meets the concept of free switching of four scenarios without node design. It can meet the characteristics of soft and flame-retardant indoor wiring at the introduction end: direct burial before the introduction end can meet the characteristics of geological environment corrosion damage to optical cables: it can meet the needs of 100 meters and below at the short-distance overhead end: it can meet the characteristics of direct pipe penetration without traction at the pipeline end. Adopting the glass fiber tape longitudinal wrapping technology, the entire glass fiber tape is longitudinally wrapped around the secondary sheath layer for external protection. During the external protection process, the longitudinal wrapping equipment performs longitudinal wrapping to separate the secondary sheath from the outer sheath; the glass fiber tape just wraps the secondary sheath layer, and there is no overlapping position to affect the optical cable structure, and also improves the overall mechanical and environmental performance of the optical cable. Adopting multi-layer superimposed rat-proofing technology, both non-metallic reinforcement and sheath layers have rat-proofing capabilities. In the non-metallic layer, it mainly relies on glass fiber material to strengthen the mouth of the mouse, and in the sheath layer, it mainly provides rat-proofing effects through the selection of materials. It has excellent performance in all scenarios and adopts a fully dry optical cable structure (no fiber paste, no cable paste), which is pollution-free to the environment: it shortens the preparation time for connection and greatly improves the construction efficiency. Therefore, this lightweight all-dielectric pipeline direct buried optical cable adopts an all-dielectric structure, which is simple in structure, light in weight, lightning-proof, rat-proof, and easy and fast to construct, greatly reducing the construction period and construction cost.

[0034] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0035] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An all-dielectric pipeline direct buried optical cable, characterized in that: The optical fiber comprises an optical fiber, an inner sheath, a first glass fiber layer and a first sheath layer which are sequentially arranged from the inside to the outside, a glass fiber rod is inserted into the first sheath layer along the extension direction; a second glass fiber layer and a second sheath layer are sequentially arranged from the inside to the outside on the outside of the first sheath layer; a plurality of optical fibers arranged in parallel are arranged on the inner side of the inner sheath, and the gap between the optical fiber and the inner sheath is filled with an aramid fiber central reinforcement member; the first glass fiber layer is a glass fiber yarn layer, and the second glass fiber layer is a glass fiber tape layer; the optical fiber comprises a core and a tight cladding layer wrapped around the outside of the core; the first sheath layer is a polyolefin layer, and the second sheath layer comprises a polyethylene sheath layer and a nylon sheath layer wrapped around the outside of the polyethylene sheath layer; a tear rope is arranged between the first sheath layer and the first glass fiber layer, and a tear rope is arranged between the second sheath layer and the second glass fiber layer; a glass fiber rod is respectively inserted into the first sheath layer on two sides away from each other.

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