WO2023079932A1 - Câble à fibres optiques et procédé de pose de câble à fibres optiques - Google Patents

Câble à fibres optiques et procédé de pose de câble à fibres optiques Download PDF

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Publication number
WO2023079932A1
WO2023079932A1 PCT/JP2022/038521 JP2022038521W WO2023079932A1 WO 2023079932 A1 WO2023079932 A1 WO 2023079932A1 JP 2022038521 W JP2022038521 W JP 2022038521W WO 2023079932 A1 WO2023079932 A1 WO 2023079932A1
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sub
optical fiber
cable
cables
sheath
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PCT/JP2022/038521
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English (en)
Japanese (ja)
Inventor
正敏 大野
彰 鯰江
健 大里
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株式会社フジクラ
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Publication of WO2023079932A1 publication Critical patent/WO2023079932A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/46—Processes or apparatus adapted for installing or repairing optical fibres or optical cables
    • G02B6/50—Underground or underwater installation; Installation through tubing, conduits or ducts
    • G02B6/52—Underground or underwater installation; Installation through tubing, conduits or ducts using fluid, e.g. air

Definitions

  • the present invention relates to an optical fiber cable and an optical fiber cable laying method.
  • This application claims priority based on Japanese Patent Application No. 2021-179274 filed in Japan on November 2, 2021, the content of which is incorporated herein.
  • the fiber optic cable includes a plurality of buffer tubes having optical fibers and a jacket containing the plurality of buffer tubes.
  • powder is applied to the surfaces of the constituent members to adjust the bonding force between the constituent members.
  • Patent Document 1 does not take into consideration the characteristics required when pneumatically feeding and laying the buffer tube. In addition, when laying a plurality of optical fiber cables by pneumatic feeding, it is necessary to carry out the cable feeding operation multiple times.
  • the present invention has been made in consideration of such circumstances, and an object of the present invention is to provide an optical fiber cable and an optical fiber cable laying method that can improve the laying efficiency.
  • an optical fiber cable includes a plurality of sub-cables and an outer sheath that accommodates the plurality of sub-cables.
  • a single sub-cable includes a plurality of optical fibers, a sheath containing the optical fibers, and having recesses and projections alternately arranged in a circumferential direction on the outer surface thereof, and a tensile strength member arranged in the sheath. and have
  • FIG. 1 is a cross-sectional view of an optical fiber cable according to this embodiment
  • FIG. FIG. 2 is an enlarged view of the sub-cable of FIG. 1
  • 2 is a schematic diagram illustrating a method of pneumatic feeding of the fiber optic cable of FIG. 1
  • FIG. It is the figure which showed the process following FIG. 3A.
  • FIG. 3C is a diagram showing a process following FIG. 3B;
  • FIG. 2 is a schematic diagram for explaining a method of pneumatically feeding a sub-cable using the outer layer sheath of the optical fiber cable of FIG. 1;
  • FIG. 5 is a cross-sectional view of an optical fiber cable according to a modification of the embodiment;
  • the optical fiber cable 100 includes a plurality of sub-cables 110 and an outer sheath 120 that accommodates the plurality of sub-cables 110 .
  • the sub-cable 110 is housed in a housing space which is a space surrounded by the outer layer sheath 120 .
  • the central axis of the accommodation space for the optical fiber cable 100 is referred to as the central axis O.
  • the longitudinal direction of the optical fiber cable 100 is simply referred to as the longitudinal direction.
  • a cross section perpendicular to the longitudinal direction is called a cross section.
  • the direction intersecting the central axis O is called the radial direction
  • the direction rotating around the central axis O is called the circumferential direction.
  • the housing space for the optical fiber cable 100 has a circular shape in a cross-sectional view.
  • the shape of the accommodation space is not limited to a circle, and if the accommodation space for the optical fiber cable 100 is non-circular, the central axis O is positioned at the centroid of the accommodation space for the optical fiber cable 100 .
  • the sub-cable 110 includes a core 10 , a sheath 20 housing the core 10 , and a plurality of tensile members 30 (inner tensile members) arranged in the sheath 20 .
  • the core 10 has a plurality of optical fiber units 11 and a pressure wrap 12 that wraps around these optical fiber units 11 .
  • the core 10 does not have to include the pressure winding 12 .
  • Each optical fiber unit 11 has a plurality of optical fibers 11a and a binding material 11b for bundling the optical fibers 11a. It should be noted that the optical fiber unit 11 may not include the binding material 11b.
  • the core 10 may be configured by wrapping the optical fibers 11a in the pressure wrap 12 without bundling them (that is, without configuring the optical fiber unit 11).
  • the optical fiber 11a included in the optical fiber unit 11 of the present embodiment may be a plurality of single optical fiber core wires, or a plurality of optical fiber core wires arranged in parallel may be adhered with a resin or the like. It may be a tape core wire.
  • the tape cord may be a so-called intermittent adhesive tape cord.
  • 1 and 2 show, by way of example, a sub-cable 110 having an optical fiber unit 11 containing intermittently bonded ribbon cores.
  • the intermittent-bonded fiber ribbon has a plurality of optical fibers 11a and a plurality of bonding portions (not shown) that bond the adjacent optical fibers 11a. More specifically, one optical fiber 11a is bonded to its adjacent optical fibers 11a at different positions in the longitudinal direction by bonding portions.
  • Adjacent optical fibers 11a are adhered to each other by an adhesive portion with a certain interval in the longitudinal direction.
  • the arrangement of the adhesive portions may be changed as appropriate.
  • the distance between adjacent bonded portions in the longitudinal direction may not be constant.
  • the intermittent adhesive tape core wire is not limited to a configuration in which a plurality of optical fibers 11a are bonded to each other by an adhesive portion. It is good also as composition made to adhere by a plurality of adhesion parts which were formed.
  • Thermosetting resins, UV-curable resins, thermoplastic resins, and the like, for example, can be used as the adhesive portion.
  • the intermittent adhesive tape core wire can change the shape of the tape core wire in the parallel direction (the width direction of the tape core wire) in which a plurality of optical fiber core wires are arranged, the optical fiber 11a aggregate
  • the degree of freedom of form increases.
  • a plurality of optical fiber units 11 having different shapes are arranged in the inner space of the sheath 20 so as to fill the gaps in the space.
  • the shapes of the plurality of optical fiber units 11 may not be the same but may be different.
  • the cross-sectional shape of the optical fiber unit 11 is not limited to the illustrated example, and may be circular, elliptical, or polygonal.
  • the plurality of optical fiber units 11 are twisted with each other around the center axis O1 of the core 10 of the sub-cable 110 .
  • a core 10 having a circular cross-sectional view is formed around the center axis O1.
  • the inner space of the sheath 20 is similarly formed in a circular shape. Note that the shape of the accommodation space for the core 10 and the sheath 20 is not limited to a circle. When the accommodation space for core 10 and sheath 20 is non-circular, central axis O1 is positioned at the centroid of the accommodation space for core 10 and sheath 20 .
  • the twisted form of the optical fiber unit 11 may be spiral or SZ.
  • the optical fiber units 11 are preferably twisted together in order to prevent an increase in transmission loss and distortion of the optical fibers 11a when the sub-cable 110 is bent.
  • the plurality of optical fiber units 11 may be arranged linearly along the longitudinal direction of the sub-cable 110 without being twisted together.
  • the pressing wrap 12 wraps the plurality of optical fiber units 11 and is formed in a cylindrical shape. Both ends (first end and second end) of the presser wrap 12 in the circumferential direction overlap each other to form a lap portion.
  • the optical fiber 11a can be protected by wrapping the optical fiber unit 11 with the pressure wrap 12. As shown in FIG. It should be noted that there may be a portion where the optical fiber 11a is not wrapped by the pressure wrap 12 in the longitudinal direction. Also, the pressure winding 12 may not be arranged.
  • a non-woven fabric, a plastic tape member, or the like can be used as the material of the presser wrap 12.
  • the presser wrap 12 is made of plastic, it can be made of polyethylene terephthalate, polyester, or the like.
  • a water-absorbing tape obtained by imparting water-absorbing properties to the above nonwoven fabric or tape member may be used. In this case, the waterproof performance of the sub-cable 110 can be enhanced.
  • the surface of the tape member may be made water absorbent by applying water absorbing powder to the surface of the tape member.
  • a plurality of tensile members 30 are arranged in the sheath 20 at regular intervals in the circumferential direction.
  • the tensile strength member 30 By arranging the tensile strength member 30 on the sheath 20, it is possible to suppress elongation and contraction of the sheath 20 in the longitudinal direction. For example, since the sheath 20 can be prevented from being excessively stretched when the sub-cable 110 is pulled in the longitudinal direction, the sub-cable 110 can be pulled by gripping the sheath 20 . Since the shrinkage of the sheath 20 due to temperature change can be reduced, it is possible to prevent the optical fiber 11a from meandering due to the shrinkage of the sheath 20 and increasing the transmission loss of light.
  • the sub-cable 110 can be fixed by holding the sheath 20 in which the tensile member 30 is arranged from the radially outer side of the sub-cable 110 .
  • the intervals at which the plurality of tensile members 30 are arranged may not be equal.
  • the number of tensile members 30 can be changed as appropriate.
  • the material of the tensile strength member 30 for example, metal wire (steel wire, etc.), tensile strength fiber (aramid fiber, etc.), FRP (Fiber Reinforced Plastics), etc. can be used.
  • FRP Fiber Reinforced Plastics
  • AFRP Analog Fiber Reinforced Plastics
  • PBO-FRP poly-paraphenylenebenzobisoxazole
  • GFRP Glass Fiber Reinforced Plastics
  • the tensile strength member 30 is embedded only in the sheath 20, but in addition to the tensile strength member 30 embedded in the sheath 20, the tensile strength member 30 is further arranged in the inner space of the sheath 20.
  • the optical fiber unit 11 , the tension member 30 and the pressure wrap 12 are arranged in the inner space of the sheath 20 .
  • a plurality of sets of tensile strength members 30 may be arranged in the sheath 20 at regular intervals in the circumferential direction.
  • the tensile members 30 in the following description are a set of tensile members 30 .
  • the sheath 20 is formed in a cylindrical shape approximately centered on the central axis O1.
  • polyolefins (PO ) resins, polyvinyl chloride (PVC), etc. can be used alone, or a plurality of types of resins can be mixed or combined.
  • additives such as flame retardants, fillers, or anti-deterioration agents may be added to the material of the sheath 20 depending on the purpose.
  • a plurality of protrusions 21 and recesses 22 are formed on the outer peripheral surface of the sheath 20 .
  • the protrusions 21 and the recesses 22 are alternately arranged in the circumferential direction. In this way, the outer peripheral surface of the sheath 20 is formed with unevenness.
  • 12 convex portions 21 are formed on the outer circumference of the sub-cable 110 .
  • the number of protrusions 21 may be more than two, and a plurality of protrusions 21 may be arranged at regular intervals in the circumferential direction.
  • the direction in which a straight line connecting one of the plurality of protrusions 21 and the central axis O1 extends is defined as the X direction
  • the direction that passes through the central axis O1 and is perpendicular to or intersects the X direction is defined as the X direction.
  • the protrusion 21 is formed to protrude in the X direction
  • the protrusion 21 is formed to protrude in the Y direction.
  • the plurality of protrusions 21 includes protrusions 21 protruding in the X direction and protrusions 21 protruding in the Y direction other than the X direction.
  • the protrusions 21 and the recesses 22 may extend linearly along the longitudinal direction, or may extend along the longitudinal direction while meandering in a spiral or SZ shape on the outer surface of the sheath 20 .
  • the change in the cross-sectional area of the sub-cable 110 in the longitudinal direction can be reduced, so that the air pressure in the duct can be stabilized in the longitudinal direction of the duct when the sub-cable 110 is air-fed.
  • the protrusions 21 and the recesses 22 may be arranged such that only the protrusions 21 of the outer peripheral surface of the sub-cable 110 are in contact with the inner peripheral surface of the outer sheath 120 of the optical fiber cable 100 .
  • the contact area between the outer layer sheath 120 and the sub-cable 110 can be reduced, and the friction can be reduced. can be done.
  • the tensile strength member 30 is arranged radially inside the convex portion 21 .
  • the thickness of the sheath 20 on the radially outer side of the tensile strength member 30 can be prevented from becoming thin, and the cable outer diameter of the sub-cable 110 can be designed to be thin.
  • the arrangement of the tensile strength member 30 and the convex portion 21 is not limited to the arrangement described above.
  • the tensile strength member 30 may be arranged at the same position as the concave portion 22 in the circumferential direction.
  • the sheath 20 protrudes radially outward from the concave portion 22.
  • the thickness of the sheath 20 at the protrusion 21 may be determined as follows.
  • the number of the tensile members 30 and the number of the protrusions 21 or the recesses 22 may not match.
  • the tensile strength member 30 and the protrusions 21 or the recesses 22 do not have to have a specific positional relationship.
  • the angle between the adjacent tensile members 30 around the central axis O1 may be different from the angle between the adjacent protrusions 21 around the central axis O1.
  • the recessed portion 22 has two connecting portions 22a and a bottom surface 22b.
  • the connecting portion 22a is connected to the radially inner end of the convex portion 21 adjacent in the circumferential direction.
  • the bottom surface 22b is positioned between the two connecting portions 22a.
  • the connecting portion 22a may be formed in a curved surface that is convex radially inward. In this case, stress can be prevented from concentrating on the connecting portion 22a, so cracking of the sheath 20 due to stress concentration can be prevented.
  • the bottom surface 22b is a part of an arc centered on the central axis O1, and has an arc shape centered on the central axis O1 in a cross-sectional view.
  • the shape of the bottom surface 22b is not limited to a part of an arc centered on the central axis O1.
  • the bottom surface 22b may have a shape in which two connecting portions 22a are linearly connected.
  • the inner surface of the recess 22 may be a curved surface that protrudes radially inward.
  • the curve of the radial end portion of the convex portion 21 and the curve of the radial end portion of the concave portion 22 are continuous curves, and the connecting portion 22a may not be clearly defined.
  • a ripcord (not shown) for tearing the sheath 20 may be arranged on the sheath 20 .
  • the ripcord may be arranged so that the entire circumference is embedded in the sheath 20, or arranged so that a part of the ripcord is exposed from the outer peripheral surface or the inner peripheral surface of the sheath 20.
  • the ripcord may be partially exposed from a plurality of openings of the sheath 20 spaced apart in the longitudinal direction on the outer peripheral surface of the sheath 20 .
  • At least one of the circumferentially equally spaced strength members 30 may be replaced by a ripcord.
  • the ripcord may be arranged inside some of the convex portions 21 among the plurality of convex portions 21 . Thereby, the ripcord can be arranged while preventing the thickness of the sheath 20 from becoming thin. Moreover, a rip cord may be arranged between two adjacent tensile strength members 30 among the tensile strength members 30 arranged at regular intervals in the circumferential direction.
  • the ripcord is arranged on the sheath 20
  • the work of removing the core 10 from the sheath 20 becomes easier.
  • the sheath 20 is torn by incising a part of the sheath 20 to take out the ripcord and pulling the ripcord in the longitudinal direction of the sub-cable 110 . By tearing the sheath 20 in this way, the core 10 can be easily taken out. However, it is possible to remove the core 10 without the ripcord.
  • the optical fiber cable 100 shown in FIG. 1 has three identically structured sub-cables 110A, 110B, and 110C.
  • the sub-cable 110 having the same structure means that the number of optical fibers 11a included in the sub-cable 110 is the same and the cable outer diameter of the sub-cable 110 is substantially the same.
  • the number of sub-cables 110 included in the optical fiber cable 100 is not limited to three, and may be two or more.
  • the plurality of sub-cables 110 may include two sub-cables 110 having different numbers of optical fibers 11a or different cable outer diameters.
  • the outer diameter of the cable referred to here is the outer diameter of the sheath 20 .
  • the optical fiber cable 100 allows the optical fiber cable 100 to be configured by bundling the sub-cables 110 each including the number of optical fibers 11a required by a plurality of installation destinations. Moreover, it is possible to obtain the optical fiber cable 100 that can effectively utilize the existing duct.
  • sub-cables 110 having different cable outer diameters are combined, it is preferable to arrange the sub-cables 110 so that the cross-sectional shape of the optical fiber cable 100 has symmetry in cross-sectional view.
  • a plurality of sub-cables 110 may be arranged so as to have symmetry with respect to the central axis O.
  • the multiple sub-cables 110 are not twisted together in the inner space of the outer layer sheath 120 . Although the details will be described later, this makes it possible to further pneumatically feed one sub-cable 110 out of the plurality of sub-cables 110 inside the outer layer sheath 120 .
  • the outer sheath 120 accommodates the plurality of sub-cables 110 in its internal space, and is formed in a cylindrical shape centered on the central axis O. As shown in FIG.
  • the shape of the outer layer sheath 120 may be formed in a shape other than a cylindrical shape according to the number and outer diameter of the sub-cables 110 accommodated inside. For example, when three sub-cables 110 are accommodated, the outer layer sheath 120 may be triangular in cross-sectional view.
  • the material of the outer layer sheath 120 the same material as that of the sheath 20 described above can be used.
  • the outer layer sheath 120 and the sheath 20 may be made of the same material, or may be made of different materials.
  • the thickness of the outer sheath 120 may be adjusted according to the shape, outer diameter, and rigidity of a bundle obtained by combining a plurality of sub-cables 110 . Also, the rigidity of the optical fiber cable 100 may be adjusted by adjusting the thickness of the outer sheath 120 .
  • a plurality of protrusions 121 and recesses 122 are formed on the outer peripheral surface of the outer sheath 120 .
  • the protrusions 121 and the recesses 122 are alternately arranged in the circumferential direction.
  • the recess 122 has two connecting portions 122a and a bottom surface 122b.
  • the connecting portion 122a is connected to the radially inner end of the convex portion 121 adjacent in the circumferential direction.
  • the bottom surface 122b is positioned between the two connecting portions 122a.
  • the connecting portion 122a is formed in a curved surface that protrudes radially inward.
  • the arrangement and shape of the projections 121 and the recesses 122 in the outer sheath 120 may have the same features as those described for the projections 21 and the recesses 22 in the sheath 20 . Therefore, the description of the arrangement and shape of the projections 121 and the recesses 122 will be omitted. It should be noted that the plurality of protrusions 121 and recesses 122 may not be formed on the outer peripheral surface of the outer sheath 120 .
  • the inner peripheral surface of the outer layer sheath 120 has no projections or recesses.
  • a convex portion is formed on the inner surface of the outer layer sheath 120 so that the contact area between the outer layer sheath 120 and the sub-cable 110 is reduced. and recesses may be formed.
  • a plurality of outer tensile members 130 are arranged in the outer layer sheath 120 at regular intervals in the circumferential direction. Note that the intervals at which the plurality of outer tensile strength members 130 are arranged may not be equal.
  • the outer tensile strength member 130 is arranged at the same position as the convex portion 121 in the circumferential direction.
  • the placement of outer strength members 130 in outer sheath 120 may be similar to the placement of strength members 30 in sheath 20 . Therefore, description of the arrangement of the outer tensile strength member 130 is omitted.
  • As the material of the outer tensile strength member 130 the same material as that of the tensile strength member 30 described above can be used.
  • the tensile member 30 and the outer tensile member 130 may be made of the same material or may be made of different materials. It should be noted that the outer tensile member 130 may not be arranged inside the outer layer sheath 120 .
  • a ripcord 140 and an interposition 150 are arranged in the space between the sub-cables 110 in the inner space of the outer layer sheath 120 .
  • the number of ripcords 140 and interpositions 150 may be one, or two or more.
  • rip cord 140 a thread (yarn) obtained by twisting fibers such as polypropylene or polyester can be used.
  • the ripcord 140 may be arranged radially outside the sub-cable 110 , and the ripcord 140 may be arranged on the outer layer sheath 120 .
  • the placement of the ripcord 140 may have features similar to those described for the placement of the ripcord within the sheath 20 .
  • Interposition 150 is a thread (yarn) obtained by twisting fibers of polypropylene, polyester, or the like having water absorption properties. Thereby, the waterproof performance inside the optical fiber cable 100 can be improved. Note that the ripcord 140 and interposer 150 may not be arranged.
  • the outer sheath 120 is easily removable so that the sub-cable 110 can be easily removed.
  • the outer layer sheath 120 is partly cut to take out the ripcord 140 , and the ripcord 140 is pulled in the longitudinal direction of the optical fiber cable 100 .
  • the outer sheath 120 is torn and the sub-cable 110 can be taken out.
  • the outer sheath 120 may also be handstrippable.
  • Hand stripping means breaking the outer layer sheath 120 by pulling it in the longitudinal direction while holding a part of the outer layer sheath 120 by hand.
  • the outer sheath 120 can be formed to be hand strippable.
  • the hand strippability of the outer sheath 120 allows the sub-cable 110 to be removed without the use of tools.
  • a notch (groove) recessed radially inward may be formed on the outer surface of the outer layer sheath 120 . In this case, the sub-cable 110 may be taken out by tearing the outer layer sheath 120 starting from the notch.
  • a microduct is a pipe pre-installed in the ground or the like.
  • a microduct is a tube that connects between underground spaces (Vaults) or between an underground space and an optical fiber laying destination such as a station building or a collective housing.
  • a microduct (first duct) D1 that connects the underground space V1 to the underground space V2
  • a plurality of microducts (second ducts) D2 that are laid in different directions from the underground space V2. (D21 to D23) are buried underground.
  • the multiple microducts D21 to D23 are also called branch ducts.
  • the underground space V1 side is called upstream, and the microduct D2 side is also called downstream, in order to explain the method of pneumatically feeding the optical fiber cable 100 from the underground space V1.
  • the downstream end of the microduct D2 may be configured to be connected to an optical fiber installation destination such as an apartment complex (not shown).
  • the optical fiber cable 100 is introduced into the microduct D1 by pneumatic feeding from the upstream first end D1a of the microduct D1.
  • a seal such as an O-ring is attached to the first end portion D1a of the microduct D1
  • a pump is connected to the seal, and air flows from the seal into the microduct D1, thereby opening the seal opening. through which the fiber optic cable 100 is introduced into the microduct D1.
  • the contact area between the inner surface of the microduct D1 and the optical fiber cable 100 can be reduced to reduce friction.
  • an air layer is formed between the optical fiber cable 100 and the microduct D1. This further reduces the friction between the optical fiber cable 100 and the microduct D1, so that the optical fiber cable 100 can be pressure-fed downstream of the microduct D1 (on the underground space V2 side).
  • the optical fiber cable 100 has the outer tensile strength members 130 arranged on the outer layer sheath 120 at equal intervals in the circumferential direction, deformation against force in the direction (longitudinal direction) along the central axis O of the optical fiber cable 100 is reduced.
  • the difficulty of rubbing becomes uniform in the circumferential direction. That is, even if the cable is bent in any direction in the duct, the buckling of the optical fiber cable 100 can be suppressed, so the distance over which the optical fiber cable 100 can be pneumatically fed can be extended. Thereby, the optical fiber cable 100 can be pneumatically fed to the downstream of the microduct D1.
  • laying of the optical fiber cable 100 into the duct may be done by a laying method other than air feeding.
  • a pulling end that grips the outer sheath 120 may be created at the tip of the optical fiber cable 100, and the pulling end may be laid by pulling with a wire downstream of the microduct D1.
  • the optical fiber cable 100 has the outer tensile member 130 in the outer layer sheath 120, the cable can be laid satisfactorily.
  • the optical fiber cable 100 is further extended by a predetermined length from the underground space V2. That is, as shown in FIG. 3A, the optical fiber cable 100a that has passed through the microduct D1 is extended from the underground space V2.
  • the length of the extended optical fiber cable 100a is appropriately set according to the length of the sub-cable 110 laid in the microduct D2.
  • the outer layer sheath 120 of the optical fiber cable 100a extending from the underground space V2 is removed, and the multiple sub-cables 110A to 110C are taken out.
  • the taken out sub-cable 110 may be bundled in a work space near the underground space V2 so as to form a figure of eight, or may be wound around a drum.
  • the sub-cables 110A-110C are pumped from the underground space V2 to the microducts D21-D23, respectively.
  • the sub-cables 110A-110C are branched and sent from the underground space V2 to the branch ducts D21-D23.
  • the method of pneumatically feeding the sub-cables 110A-110C to the microducts D21-D23, respectively, is the same as the method of pneumatically feeding the optical fiber cable 100 to the microduct D1.
  • a pump is connected to the seal attached to the upstream end of the microduct D21, and air is caused to flow from the seal into the microduct D21.
  • the sub-cable 110A is introduced into the microduct D21 through. Since the surface of the sub-cable 110A is uneven, the contact area between the inner surface of the microduct D21 and the sub-cable 110A can be reduced to reduce friction. Also, during air feeding, an air layer is formed between the sub-cable 110A and the microduct D21. Thereby, the sub-cable 110A can be pneumatically fed downstream of the microduct D21.
  • sub-cable 110A since the sub-cable 110A has the tensile strength members 30 arranged in the sheath 20 at equal intervals in the circumferential direction, there is no directivity in cable bending and the sub-cable 110A is less likely to buckle. As a result, the distance over which the sub-cable 110A can be pneumatically fed can be extended, so that the sub-cable 110A can be pneumatically fed downstream of the microduct D21. After that, sub-cables 110B and 110C are similarly pneumatically fed to microducts D22 and D23, respectively.
  • the optical fiber cable 100 can be laid in the first duct D1 by pneumatic feeding, and the plurality of sub-cables 110 branched from the optical fiber cable 100 can be laid in different ducts D21 to D23 by pneumatic feeding. can.
  • the optical fiber cable 100 can be laid more easily than, for example, the case where the three sub-cables 110 are simply introduced into the first duct D1 and the second duct D2 and routed to the laying destination. can be laid in
  • the cable pumping operation is performed three times.
  • the work of pumping the cable to the first duct D1 can be reduced to one. In this way, since the number of operations for laying cables by pneumatic feeding can be reduced, construction can be easily performed. In addition, construction costs can be reduced.
  • the upstream first duct D1 may have a larger inner diameter than the second duct D2 so that more optical fibers can be laid.
  • the cross-sectional area occupied by the sub-cables 110 is small with respect to the void area in the first duct D1. Bending may occur. In this case, the sub-cable 110 may receive a large compressive force and buckle.
  • the optical fiber cable 100 having an outer diameter larger than that of the sub-cable 110 is laid in the first duct D1 on the upstream side. In this case, since the cross-sectional area occupied by the optical fiber cable 100 with respect to the first duct D1 can be increased, buckling of the optical fiber cable 100 in the first duct D1 can be prevented.
  • the optical fiber cable 100 of this embodiment includes a plurality of sub-cables 110 and an outer layer sheath 120 that accommodates the plurality of sub-cables 110.
  • At least one cable included in the plurality of sub-cables 110 The sub-cable 110 includes a plurality of optical fibers 11a, a sheath 20 that accommodates the optical fibers 11a, and has convex portions 21 and concave portions 22 that are alternately arranged in the circumferential direction on its outer surface, and is embedded in the sheath 20. and a tensile strength member 30 .
  • the optical fiber cable 100 of the present embodiment the optical fiber cable 100 bundled with a plurality of sub-cables 110 is laid, and the plurality of sub-cables 110 branched from the optical fiber cable 100 are air-fed in different routes. It is possible to lay it in Therefore, the cable laying efficiency can be improved.
  • the optical fiber cable 100 can be laid in a state where the plurality of sub-cables 110 are bundled in the first duct D1. , the optical fiber cable 100 can be laid more easily.
  • the tensile members 30 may be arranged in the sheath 20 of one sub-cable 110 at regular intervals in the circumferential direction of the sub-cable 110 .
  • the resistance to deformation of the sub-cable 110 becomes uniform in the circumferential direction. That is, the bending directionality of the sub-cable 110 can be eliminated. Therefore, when the sub-cable 110 is pneumatically fed, the cable can be prevented from buckling, and the pumping characteristics of the sub-cable 110 can be improved.
  • the plurality of sub-cables 110 may include two sub-cables having different numbers of optical fibers 11a or different cable outer diameters. In this way, since it is possible to combine sub-cables 110 having different numbers of optical fibers 11a, the degree of freedom in designing the optical fiber cable 100 can be increased. For example, the number of optical fibers 11a required for each installation destination can be mounted on each sub-cable 110 in accordance with various pipelines for laying the optical fiber cable 100 .
  • the outer diameter of the optical fiber cable 100 that can be laid is obtained, and each sub The number of optical fibers 11a mounted on the cable 110 can be set. In this way, existing ducts can be effectively used, so an efficient optical distribution network can be constructed.
  • a ripcord 140 may be arranged radially outward of the plurality of sub-cables 110 . This makes it possible to easily remove the outer layer sheath 120 . Further, it becomes possible to easily take out the sub-cable 110 by dismantling the optical fiber cable 100 after passing through the first duct D1.
  • it may further include a plurality of outer tensile members 130 embedded in the outer layer sheath 120 , and the outer tensile members 130 may be arranged at equal intervals in the circumferential direction of the optical fiber cable 100 .
  • the resistance to deformation of the optical fiber cable 100 becomes uniform in the circumferential direction. Therefore, when the optical fiber cable 100 is pneumatically fed, the cable can be prevented from buckling, and the pumping characteristics of the optical fiber cable 100 can be improved.
  • the handleability is improved.
  • the surface of the outer sheath 120 may be formed with convex portions 121 and concave portions 122 that are alternately arranged in the circumferential direction.
  • the method of laying the optical fiber cable 100 of the present embodiment removes at least a portion of the outer layer sheath 120 of the optical fiber cable 100 inserted through the first duct D1, thereby removing the plurality of subs accommodated in the outer layer sheath 120.
  • the cable 110 is taken out, and at least one sub-cable 110 included in the plurality of sub-cables 110 taken out is pneumatically fed to the second duct D2. This makes it possible to lay the sub-cables 110 more easily than the case where the three sub-cables 110 are simply introduced into the first duct D1 and the second duct D2 and routed to the laying destination.
  • the lengths of air fed to the microducts D21-D23 are substantially the same.
  • the plurality of sub-cables 110 may include two sub-cables with different cable lengths. That is, the cable length of one or more sub-cables 110 may be longer than the outer layer sheath 120 .
  • the optical fiber cable 100 shown in FIG. 4 is configured such that the sub-cable 110A is longer than the sub-cables 110B and 110C. length.
  • the length of the sub-cable 110A extending from the rear end 100b is set based on the difference between the longest duct and the shortest duct among the plurality of second ducts D21 to D23. .
  • the lengths of microducts D22 and D23 are equal, and the length of microduct D21 is longer than that of microducts D22 and D23.
  • the length of the sub-cable 110A extending from the rear end 100b is equivalent to the length difference between the microduct D21 and the microducts D22 and D23.
  • FIG. 4 is a diagram for explaining the process following FIG. 3B in the optical fiber cable 100 with the sub-cable 110A extending by a predetermined length from the rear end 100b.
  • the outer layer sheath 120 After removing the outer layer sheath 120 and taking out the plurality of sub-cables 110 in the vicinity of the underground space V2, the outer layer sheath 120 is used as a duct at the rear end 100b of the optical fiber cable 100 to extend the sub-cable 110A from the rear end 100b to the underground space. Air pressure can be fed to the V2 side.
  • a seal such as an O-ring is attached to the outer sheath 120, a pump is connected to the seal, and air flows from the seal into the outer sheath 120, thereby opening the seal.
  • the sub-cable 110A extending from the rear end 100b is introduced into the outer layer sheath 120 through.
  • the sub-cables 110B and 110C, the ripcord 140 and the interposition 150 arranged in the inner space of the outer layer sheath 120 may be fixed in the vicinity of the rear end 100b so as not to move downstream.
  • the sub-cables 110 are not twisted together, only the sub-cable 110A can be pneumatically fed within the outer layer sheath 120 .
  • the cable pumping operation may be performed in the underground space V1.
  • the sub-cables 110A-110C are pneumatically fed to the microducts D21-D23, respectively, in the same manner as the procedure described with reference to FIG. 3C.
  • the sub-cable 110A extending from the underground space V2 is longer than the sub-cables 110B and 110C extending from the underground space V2. Therefore, the sub-cable 110A can be laid to a destination farther than the destinations to which the sub-cables 110B and 110C are laid.
  • one sub-cable 110 out of the plurality of sub-cables 110 may be pneumatically fed inside the outer layer sheath 120 .
  • an optical distribution network can be constructed efficiently.
  • the multiple sub-cables 110 do not have to be twisted together.
  • the sub-cable 110 can be pneumatically fed using the outer layer sheath 120 as a duct.
  • the sub-cables 110 are laid in different second ducts D2, but two or more sub-cables 110 are bundled and air-fed to the same second duct D2. good too.
  • the sub-cables 110B and 110C may be bundled with a spiral tube or a binding material and air-fed to the second duct D2 at the same time.
  • a collective optical fiber cable 200 may be formed that includes a plurality of optical fiber cables 100 and a collective sheath 220 that accommodates the plurality of optical fiber cables 100 .
  • the collective sheath 220 may have a plurality of protrusions 221 and recesses 222 formed on its outer surface, and a tensile strength member 230 disposed inside.
  • the arrangement and shape of the projections 221, the recesses 222, and the tensile strength member 230 may have the same features as those described for the projections 21, the recesses 22, and the tensile strength member 30 of the sheath 20 described above.
  • the collective optical fiber cable 200 can be installed in an underground pipeline having a first branch point on the upstream side and a second branch point on the downstream side (that is, a pipeline having two branch points on the installation route).
  • a plurality of optical fiber cables 100 can be taken out by removing the collective sheath 220 at the first branch point and laid in ducts extending in different directions.
  • the outer layer sheath 120 is removed to allow a plurality of sub-cables 110 to be taken out and laid in ducts extending in different directions.
  • the plurality of optical fiber cables 100 housed in the collective sheath 220 may have different structures.
  • some of the fiber optic cables housed in the collecting sheath 220 may be known fiber optic cables.
  • the protrusions 21, 121, 221 and the recesses 22, 122, 222 do not have to extend in the longitudinal direction.
  • the cables 110, 100, 200 may be formed with projections 21, 121, 221 protruding in a hemispherical shape when viewed from the circumferential direction.
  • recesses 22, 122, and 222 recessed in a hemispherical shape may be formed. Thereby, the contact area between the cable and the microduct can be reduced.
  • each of the sub-cables 110 included in the optical fiber cable 100 has the convex portion 21 and the concave portion 22 formed on the outer surface of the sheath 20, but at least one sub-cable included in the optical fiber cable 100 It is sufficient that the sub-cable 110 is formed with the convex portion 21 and the concave portion 22 . That is, the sub-cables 110 other than the one sub-cable 110 do not have to be formed with the convex portion and the concave portion.
  • the plurality of sub-cables 110 may include a plurality of sub-cables 110 that are twisted together and sub-cables 110 that are not twisted with other sub-cables. That is, at least one sub-cable 110 among the plurality of sub-cables 110 does not have to be twisted together with other sub-cables 110 . In this case, it is possible to further pneumatically feed the untwisted sub-cable 110 inside the outer layer sheath 120 .
  • the convex portion 21 and the concave portion 22 are formed only on the outer surface of the untwisted sub-cable 110, and the convex portion and concave portion are not formed on the sub-cables 110 other than the one sub-cable 110. good too.
  • the ends of the plurality of sub-cables 110 may be shifted in the longitudinal direction.
  • the tip of the sub-cable 110 and the end of the outer layer sheath 120 do not have to be arranged at the same position in the longitudinal direction. This facilitates laying of the optical fiber cable 100 in the microduct D1.
  • an appendage such as a pulling end such as a connector or pull eye may be placed at each end of the sub-cable 110 . Even in this case, by shifting the position of each tip of the plurality of sub-cables 110 in the longitudinal direction, it is possible to prevent the outer diameter of a portion of the optical fiber cable 100 from becoming excessively large. As a result, the laying work can be easily performed even in a state in which an accessory is attached to each end of the sub-cable 110 .

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Light Guides In General And Applications Therefor (AREA)

Abstract

L'invention concerne un câble à fibres optiques (100) comprenant : une pluralité de sous-câbles (10) ; et une gaine de couche externe (120) qui reçoit les sous-câbles. Au moins un sous-câble compris dans les sous-câbles comporte : une pluralité de fibres optiques (11a) ; une gaine (21) qui reçoit les fibres optiques et dans laquelle des parties de projection et des parties en retrait sont formées de manière à être disposées en alternance sur la surface extérieure dans la direction circonférentielle ; et un élément de résistance à la traction (30) disposée à l'intérieur de la gaine.
PCT/JP2022/038521 2021-11-02 2022-10-17 Câble à fibres optiques et procédé de pose de câble à fibres optiques WO2023079932A1 (fr)

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JP2021-179274 2021-11-02
JP2021179274 2021-11-02

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117631185A (zh) * 2024-01-26 2024-03-01 江苏中天科技股份有限公司 一种易安装蝶形光缆及其安装管道

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Publication number Priority date Publication date Assignee Title
JP2000243150A (ja) * 1999-02-17 2000-09-08 Sumitomo Electric Ind Ltd 圧送用パイプ入りケーブル
KR20100083408A (ko) * 2009-01-13 2010-07-22 엘에스전선 주식회사 내충격 특성을 구비한 루즈튜브형 광케이블
JP2010271382A (ja) * 2009-05-19 2010-12-02 Hitachi Cable Ltd 光電気複合ケーブル
US20160216468A1 (en) * 2013-06-28 2016-07-28 Corning Optical Communications LLC Coupling system for a fiber optic cable
WO2020075734A1 (fr) * 2018-10-11 2020-04-16 株式会社フジクラ Câble à fibres optiques
JP2020204752A (ja) * 2019-06-19 2020-12-24 住友電気工業株式会社 光ファイバケーブル

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000243150A (ja) * 1999-02-17 2000-09-08 Sumitomo Electric Ind Ltd 圧送用パイプ入りケーブル
KR20100083408A (ko) * 2009-01-13 2010-07-22 엘에스전선 주식회사 내충격 특성을 구비한 루즈튜브형 광케이블
JP2010271382A (ja) * 2009-05-19 2010-12-02 Hitachi Cable Ltd 光電気複合ケーブル
US20160216468A1 (en) * 2013-06-28 2016-07-28 Corning Optical Communications LLC Coupling system for a fiber optic cable
WO2020075734A1 (fr) * 2018-10-11 2020-04-16 株式会社フジクラ Câble à fibres optiques
JP2020204752A (ja) * 2019-06-19 2020-12-24 住友電気工業株式会社 光ファイバケーブル

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117631185A (zh) * 2024-01-26 2024-03-01 江苏中天科技股份有限公司 一种易安装蝶形光缆及其安装管道
CN117631185B (zh) * 2024-01-26 2024-04-02 江苏中天科技股份有限公司 一种易安装蝶形光缆及其安装管道

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