JP2009244550A - Optical fiber cable and construction method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cable which allows improvement of workability of anchoring to an electric pole or the like, and to provide a construction method thereof. <P>SOLUTION: An optical fiber cable 1 includes an optical element 2 having a coated optical fiber 5 covered with a sheath 6 and has a circular traverse cross-section and a support line 3 supporting the optical element 2, and the optical element 2 loosely spirally wound around an outer peripheral in such a state that its pitch can be partially changed. The optical element 2 is brought away from a fixing part 18 of the support line 3, which fixes the support line 3 to an anchoring tool 16, in the periphery of the fixing part 18 so as to shorten the winding pitch, and in this state, the fixing part 18 of the support line 3 is fixed to the anchoring tool 16. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical fiber cable suitable for use in constructing an optical fiber network and a laying method thereof.

  In recent years, as an optical fiber cable used for applications such as FTTH (Fiber To The Home), an optical fiber cable for pulling down from a trunk optical fiber cable installed in an aerial such as a utility pole to a subscriber's house has been widely used. ing. An optical fiber cable for pulling is described in, for example, Patent Document 1.

An example of a pull-down optical fiber cable is shown in FIG.
This pull-down optical fiber cable 100 has a configuration in which an element portion 101 and a support wire 102 are connected by a neck portion 103.

  In the element portion 101, an optical fiber core wire 105 disposed in the center and strength members 106 disposed on both sides of the optical fiber core wire 105 are collectively covered with a resin 107 such as flame retardant polyethylene. For example, the optical fiber core 105 is formed by coating the outer periphery of a glass optical fiber having an outer diameter of 125 μm with an ultraviolet curable resin, and has an outer diameter of 250 μm. The strength member 106 is made of steel, fiber reinforced plastic (FRP), or the like, and has an outer diameter of about 0.4 mm. Since the optical fiber core 105 and the tensile body 106 are collectively covered, the tensile body 106 receives an external force such as a tension applied to the optical fiber cable 100 to protect the optical fiber core 105 from the external force. ing. The element portion 101 is generally about 3 mm in major axis and 2 mm in minor axis.

The support wire 102 is configured to have strength to support the optical fiber cable 100 in an aerial manner, and a support body 108 such as steel or fiber reinforced plastic is covered with the same resin 107 as the element portion 101. The outer diameter of the support 108 is about 1.2 mm, and the outer diameter of the support wire 102 is about 2 mm.
The neck portion 103 is formed integrally with the element portion 101 and the support wire 102 by the same resin 107 as the element portion 101 and the support wire 102, and the element portion 101 and the support wire 102 are separated by being torn. Can do.

  Since the optical fiber cable in such a form has a support line that can be separated from the element portion which is the cable body, a suspension line such as a power pole or a cable already laid between the power poles, an eaves of a subscriber's house, etc. It can be fastened using a retainer.

JP 2000-171673 A

  When the optical fiber cable is fastened to a power pole or the like at the time of laying, the support wire 102 separated from the element portion 101 as shown in FIG. 6 is wound around the retainer 111 attached to the power pole 110 or the like by tearing the neck portion. Equally fixed. For this reason, the element portion 101 separated from the support wire 102 is not constrained, and is easily subjected to external force. Therefore, it is necessary to cover the element portion 101 with the protective spiral tube 112. The work becomes complicated.

  The objective of this invention is providing the optical fiber cable which can improve the workability | operativity of the securing work to an electric pole etc., and its laying method.

  An optical fiber cable according to the present invention that can solve the above-described problems includes an optical element that covers an optical fiber core wire with a jacket and has a circular cross section, and a support line that supports the optical element. An optical fiber cable provided, wherein the optical element is wound helically around the outer periphery of the support line in a state where the pitch can be partially changed.

  The optical fiber cable which concerns on this invention WHEREIN: It is preferable that the elasticity modulus of the said jacket is 300 Mpa or more.

  In the optical fiber cable according to the present invention, it is preferable that a tensile fiber is disposed between the optical fiber core wire and the jacket.

  The optical fiber cable which concerns on this invention WHEREIN: It is preferable that the said optical element is loosely wound helically on the outer periphery of the said support wire in the state arranged in parallel.

  In the optical fiber cable according to the present invention, it is desirable that an outer diameter of the optical element is not more than an outer diameter of the support wire.

  In the optical fiber cable according to the present invention, it is desirable that an outer diameter of the optical element is 2.0 mm or less.

  Also, the optical fiber cable laying method according to the present invention that can solve the above-described problems is the optical element in the periphery of the fixing part that fixes the support wire to the retainer. The fixing portion of the support wire is fixed to the retainer in a state of being moved away from the direction.

  According to the present invention, since the optical element is spirally wound around the outer periphery of the support line in a state where the pitch can be partially changed, the optical element can be moved along the longitudinal direction of the support line. It is. Therefore, the optical element around the fixed part that fixes the support wire to the retainer is moved away from the fixed part so as to shorten the winding pitch. Without loosening, the fixing portion of the support wire can be pulled out, and the support wire can be fixed to the retainer with this fixing portion. Therefore, since the restraint state of the optical element by the support line can be maintained, it is not necessary to cover the optical element with a protective spiral tube or the like, and the workability of the retaining work to the utility pole or the like is improved.

Hereinafter, an example of an embodiment of an optical fiber cable and its laying method according to the present invention will be described with reference to FIGS.
1 is a cross-sectional perspective view showing an optical fiber cable, FIG. 2 is a front view showing a connection state of the optical fiber cable, FIG. 3 is a perspective view showing a state in which the optical fiber cable is fastened to a retaining device, and FIG. It is a cross-sectional perspective view which shows another example of this.

  As shown in FIG. 1, the optical fiber cable 1 has a configuration in which a long optical element 2 is supported by being wound around an outer periphery of a long support wire 3.

  The optical element 2 has a circular cross section, and an optical fiber core 5 in which a glass fiber composed of a core and a cladding is provided with a coating such as an ultraviolet curable resin is provided at the center. The periphery of 5 is covered with a jacket 6 over the entire length. In the optical element 2, the outer diameter of the optical fiber core wire 5 is, for example, 250 μm, and the entire outer diameter is 1.0 to 2.0 mm.

The jacket 6 is made of a hard synthetic resin having an elastic modulus of 300 MPa or more, and has low friction. The jacket 6 is made of, for example, high density polyethylene (HDPE). High-density polyethylene is excellent in tackiness and therefore has lower friction than low-density polyethylene and linear low-density polyethylene even without a lubricant.
A tensile strength fiber 7 is disposed between the optical fiber core wire 5 and the jacket 6 so as to surround the entire circumference of the optical fiber core wire 5. The tensile strength fiber 7 is made of, for example, an aramid fiber.

  When such an optical element 2 is connected to another optical element 2 as shown in FIG. 2, a connector 8 is attached to the connecting end of the optical element 2 so as to directly grip the outer cover 6, and this connector 8 and the connector 8 of the optical element 2 at the connection destination attached to the connection end in the same manner, the optical fiber core wires 5 are brought into abutted state and optically connected.

As shown in FIG. 1, the support wire 3 has a circular cross section, and is provided with a long support 11 at the center, and the periphery of the support 11 is covered with a jacket 12 over the entire length. It will be.
The support 11 has a circular cross section, and is made of, for example, steel or fiber reinforced plastic (FRP). The outer diameter of the support 11 is, for example, 1.0 mm.

  The jacket 12 of the support wire 3 is made of, for example, low density polyethylene (LDPE), high density polyethylene (HDPE), or the like. The outer diameter of the support wire 3 that is the outer diameter of the outer jacket 12 is preferably equal to or larger than the outer diameter of the optical element 2 and is, for example, 2.0 mm.

  The optical fiber cable 1 of this embodiment is loosely wound spirally around the outer periphery of the support wire 3 in a state where the optical element 2 can partially change the pitch. That is, the optical element 2 is wound so as to be partially exposed without completely covering the outer peripheral surface of the support line 3 and so as to be movable in the length direction of the support line 3 on the support line 3. ing. By this loose winding, the optical element 2 is allowed to escape by moving the distortion caused by the external force with respect to the support line 3. The winding pitch of the optical element 2 with respect to the support line 3 is preferably 300 mm or more, for example, 600 mm.

Next, a method for laying the optical fiber cable 1 will be described.
When the optical fiber cable 1 is fastened to a power pole or the like when laying, the optical fiber cable 1 is fixed to a retainer 16 fastened to the power pole 15 as shown in FIG.

  At this time, first, the optical element 2 around the fixing portion 18 that fixes the support wire 3 to the retainer 16 is moved toward both sides or one side in a direction away from the fixing portion 18 so as to shorten the winding pitch (twisting pitch). The fixing part 18 of the support wire 3 is pulled out. At this time, the optical element 2 does not sag with respect to the support line 3, and the tension of the optical element 2 depends on the extra length generated by pulling out the support line 3 so that the tension is not applied more than necessary. Adjust the amount.

  Next, the fixing portion 18 drawn from the optical fiber cable 1 in the support wire 3 is fixed to the retainer 16. At this time, the fixing portion 18 is fixed by being wound around the winding portion 20 of the retainer 16.

  Thus, according to the optical fiber cable 1 and its laying method of the present embodiment, the optical element 2 is helically wound around the outer periphery of the support wire 3 in a state where the pitch can be partially changed. By bringing the optical element 2 around the fixing part 18 that fixes the support wire 3 to the retainer 16 in a direction away from the fixing part 18 so as to shorten the winding pitch, without applying excessive tension to the optical element 2, Further, the fixing portion 18 of the support wire 3 can be pulled out without loosening the optical element 2, and the support wire 3 can be fixed to the retainer 16 by the fixing portion 18. Therefore, since the restraint state of the optical element 2 by the support wire 3 can be maintained, the work of covering the optical element 2 with a protective spiral tube or the like is not necessary, and the workability of the work of retaining the electric pole 15 is improved.

  Further, since the neck tearing work required in the conventional optical fiber cable in which the support line and the element part are connected at the neck is not required, the workability of the fastening work is further improved.

  In addition, since the elastic modulus of the outer cover 6 of the optical element 2 is as hard as 300 MPa or more, the optical element 2 is slidable with respect to the support line 3 and can be moved easily. Therefore, the workability of the holding work is further improved. Since the jacket 6 of the optical element 2 is hard, it is possible to protect the optical fiber core wire 5 from insects such as peanuts that pierce the jacket 6 with a needle.

  Further, since the tensile strength fiber 7 is disposed between the optical fiber core wire 5 and the jacket 6 of the optical element 2, even if tension is applied when the optical element 2 moves on the support line 3. The optical fiber core wire 5 can be protected.

  Further, since the outer diameter of the support wire 3 is formed to be larger than the outer diameter of the optical element 2, for example, when the operator steps on the optical fiber cable 1 during the laying operation, the optical element 2 at the stepping position is also provided. Since the wire is loosely wound, the optical element 2 is prevented from being stepped on when the height of the support line 3 is higher than the height of the optical element 2. . In addition, since the outer diameter of the optical element 2 is 2 mm or less, insects such as bearfish cannot stay stably, so the outer sheath 6 is less likely to be stabbed by insects, and the optical fiber core wire 5 is further protected. can do.

  Here, as shown in FIG. 4, when a plurality of optical elements 2 are supported by a single support line 3, the plurality of optical elements 2 are arranged in parallel on the outer periphery of the support line 3. What is necessary is just to loosely wind so that a pitch can be changed partially. That is, the plurality of optical elements 2 can be moved in the length direction of the support line 3 on the support line 3 so as to be partially exposed without completely covering the outer peripheral surface of the support line 3. Wrapped.

It is sectional drawing which shows the example of embodiment of the optical fiber cable which concerns on this invention. It is a front view which shows the connection state of the optical fiber cable of FIG. It is a perspective view which shows the state which fastened the optical fiber cable of FIG. 1 to the retainer. It is a cross-sectional perspective view which shows another example of the optical fiber cable which concerns on this invention. It is a cross-sectional perspective view which shows the example of the conventional optical fiber cable. It is a perspective view which shows the state which fastened the conventional optical fiber cable to the retainer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical fiber cable, 2 ... Optical element, 3 ... Support line, 5 ... Optical fiber core wire, 6 ... Outer jacket, 7 ... Tensile fiber, 16 ... Tension tool, 18 ... Fixing part.

Claims (7)

An optical fiber cable comprising an optical element that covers an optical fiber core wire with a jacket and has a circular cross section, and a support line that supports the optical element,
An optical fiber cable, wherein the optical element is spirally wound around the outer periphery of the support line in a state where the pitch can be partially changed. The optical fiber cable according to claim 1,
An optical fiber cable, wherein the jacket has an elastic modulus of 300 MPa or more. The optical fiber cable according to claim 1 or 2,
An optical fiber cable, wherein tensile strength fibers are disposed between the optical fiber core wire and the jacket. An optical fiber cable according to any one of claims 1 to 3,
An optical fiber cable, wherein a plurality of the optical elements are arranged in parallel and are spirally wound around the outer periphery of the support wire. An optical fiber cable according to any one of claims 1 to 4,
An optical fiber cable, wherein an outer diameter of the optical element is equal to or smaller than an outer diameter of the support wire. An optical fiber cable according to any one of claims 1 to 5,
An optical fiber cable, wherein an outer diameter of the optical element is 2.0 mm or less. A method of laying the optical fiber cable according to any one of claims 1 to 6,
Fix the fixing part of the support line to the retainer in a state where the optical element around the fixing part for fixing the support line to the retainer is moved away from the fixing part so as to shorten the winding pitch. An optical fiber cable laying method comprising:

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