JP5546412B2 - Optical cable - Google Patents

Description

  The present invention relates to a collective optical cable in which a plurality of optical fiber cords are assembled and collectively covered with a cable jacket together with a tension member.

  The optical fiber cord surrounds the optical fiber core wire with high-strength fibers along the longitudinal direction, covers the outside with a resin sheath, attaches an optical connector etc. to the end, and connects indoor optical connections and optical equipment Is used. Further, when laying indoors, an aggregate optical cable is used in which a plurality of single-core optical fiber cords are gathered together around a tension member and collectively covered with a cable jacket (see, for example, Patent Document 1). .

  Also, there is an indoor optical fiber laying called an optical indoor cable. In this optical indoor cable, tension members (also referred to as tension members) are disposed on both sides of one to several optical fiber cores and are collectively covered with a jacket. In response to the recent increase in demand for optical wiring, this optical indoor cable may be used in such a form that it is inserted through a space portion such as an existing pipe line in which a communication cable or the like is laid and additionally laid. For this reason, as an optical indoor cable, it is known to use a jacket material that reduces the dynamic friction coefficient of the cable surface so that it can be easily inserted into a narrow space portion (for example, patent document). 2).

JP 2001-221935 A JP 2007-183477 A

  The installation of optical cables in a data center or the like is performed using a space under the floor or the like. However, as the number of transmission devices and servers is increased, the number of installed cables increases and congestion occurs. In addition, an existing optical cable may need to be replaced due to a change in the type of the optical cable or the like for improvement of service. For this reason, it is required to lay out a new optical cable after removing the old optical cable, but when removing the existing old optical cable, it does not affect other optical cables in use and can be easily done. Need to be done.

  FIG. 4 is a diagram showing a state where an unnecessary optical cable is pulled out and removed from an optical cable laid in multiple lines under an office floor or the like. The optical cable 1 is formed by twisting a plurality of optical fiber cords 2 as disclosed in Patent Document 1 around the outer periphery of a tension member 7 and covering with a cable jacket 8. A plurality of optical cables 1 are stored and laid so as to be bundled with a wiring rod or the like. When removing the unnecessary optical cable 1 ′, the optical cable 1 can be easily removed by the frictional resistance between the cable jackets 8 of the optical cable. There was a problem that could not be pulled out. Further, the cable jacket 8 having a low hardness and tensile strength has a problem in that the outer cover of another optical cable is damaged when the cable jacket 8 is pulled out.

  The present invention has been made in view of the above-described situation, and an aggregate optical cable that is no longer needed from among a plurality of aggregate optical cables obtained by assembling a plurality of optical fiber cords affects other aggregate optical cables. An object of the present invention is to provide a collective optical cable that can be easily pulled out without any problems.

An aggregate optical cable according to the present invention is an aggregate optical cable in which a plurality of optical fiber cords are aggregated and collectively covered with a cable jacket together with a tension member, and a tension member made of steel wire or fiber reinforced plastic is arranged at the center, and the periphery thereof. A plurality of the optical fiber cords are twisted together, and the outer periphery of the cable jacket is wound into a circular shape so that a portion that does not overlap with a portion that overlaps the presser winding tape is formed, and the surface of the cable jacket is the presser winding tape. And the convex width is larger than the concave width, the dynamic friction coefficient (JIS K7125) of the cable jacket is 0.3 or less, the hardness (JIS K7215) is 55 or more, and the tensile strength ( JIS K7113) is 10MP or more.

Further, the above-mentioned aggregated cable is pre Symbol cable jacket is in, it is formed of a resin consisting mainly of polyethylene, which is preferably bonded to the holding tape.

  According to the present invention, it is possible to easily pull out a predetermined aggregated optical cable that is no longer required from a large number of aggregated optical cables stacked in a bundle with a low frictional force without damaging other aggregated optical cables. Can be improved. Further, the cable jacket can be integrated with the horizontally wound presser winding tape in the longitudinal direction so that the cable jacket is not easily peeled off.

It is a figure which shows the example of the assembly | attachment optical cable which gathered the several optical fiber cord used as the object of this invention, and integrated it with the jacket. FIG. 5 is a diagram showing an example in which a plurality of optical fiber cords are wound in a side-winding manner with a presser-wound tape in the collective optical cable according to the present invention. It is a figure which shows the evaluation result of the aggregated optical cable by this invention. It is a figure explaining the subject of a prior art.

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of an aggregate optical cable (hereinafter simply referred to as an optical cable) that is an object of the present invention, and shows an example of an optical cable having a circular cross section in which six optical fiber cords are aggregated. In the figure, 1 is a collective optical cable, 2 is an optical fiber cord, 3 is a core wire coating, 4 is an optical fiber core wire, 5 is a high-strength fiber, 6 is a cord jacket, 7 is a tension member, 7a is a tensile strength wire, 7b Is a jacket, 8 is a cable jacket , 10 is a presser winding tape, and 11 is a tear string.

The optical cable 1 shown in FIG. 1 has a 6- core optical fiber cord 2 twisted around a tension member 7 arranged in the center (six examples are shown in the figure) twisted and covered together with a cable jacket 8 . It is an optical cable. As the optical fiber cord 2, for example, an optical fiber core wire 4 is used in which the outer periphery of a glass fiber having an outer diameter of 125 μm is coated with a protective coating having an outer diameter of about 250 μm and further coated with a core wire coating 3 having an outer diameter of 0.9 mm. Then, the outer periphery of the optical fiber core 4 is covered with a cord jacket 6 having an outer diameter of about 1.5 mm to 2.2 mm through a high-strength fiber 5 such as an aramid fiber to form an optical fiber cord 2.

The tension member 7 is formed of a steel wire or fiber reinforced plastic (FRP). For example, a member having a resin coating 7b on the surface of a tensile strength wire (steel wire) 7a having an outer diameter of 1.4 mm or less can be used. . Moreover, when the tensile strength wire 7a is FRP, a wire material obtained by hardening high-strength fibers such as glass fibers or aramid fibers with a resin may be used, and the resin coating may be applied in the same manner as in the case of steel wires .

A press-wound tape 10 made of nonwoven fabric or the like, preferably a non-halogen flame-resistant tape, is wound around the outer periphery of the optical fiber cord 2 by wrapping horizontal winding in which overlapping portions do not overlap with each other. . And the outer side is covered with a cable jacket 8 to form a multi-core optical cable having a circular cross section .

Cable jacket 8, a resin material having a coefficient of dynamic friction and hardness and tensile strength of Jo Tokoro, is formed by extrusion molding. Inside the cable jacket 8, leave embedded tear cord 11, tearing the cable jacket 8 in the longitudinal direction by pulling the string tear the cited, to facilitate the extraction of the optical fiber cord 2.
Further, by winding a presser winding tape 10 with laterally wound, a step is generated against the cable jacket 8 to the tape edge portion, the cable core comprising a holding tape 10 to suppress the axial movement of the cable jacket 8 The binding force to can be increased.

When a resin material mainly composed of polyethylene resin is used for the cable jacket 8 , a tape made of a nonwoven fabric mainly composed of polyethylene resin may be used for the press-wound tape 10. In this case, by heat during extrusion of the cable jacket 8 may be a cable jacket 8 and holding tape 10 is adhered and integrated to more effectively suppress the movement of the cable jacket 8. If an optical fiber cord 2 of the optical cable 1 having an outer diameter of 1.7 mm is used, an optical cable having an outer diameter of about 8 mm is obtained.

Figure 2 is, in the configuration of FIG. 1, when the wound lap the holding tape 10 is an example to wind in the overlapping width S. As shown in FIG. 2A, the outer surface 8 ′ of the cable jacket 8 is uneven in the longitudinal direction due to a portion that does not overlap the overlapped portion of the presser winding tape 10. By selecting the overlap width S described above, the convex width becomes larger than the concave width. Thereby, as shown in FIG. 2 (B), when a plurality of optical cables 1 are adjacent to each other, and the cable jackets 8 are in contact with each other, only the convex portions are in contact with each other to reduce the contact area. It can be reduced. As a result, the frictional contact surfaces between the optical cables are reduced, and the pulling force of the optical cable can be reduced.

Fig. 3 shows dynamic friction coefficient and pullability (cable length 10m), cable jacket tensile strength, and jacket damage when stripping optical cables when various resin materials (A to G) are used for the cable jacket. It is a figure which shows the result of having verified D hardness of a cable jacket, and the jacket abrasion property at the time of optical cable peeling. The optical cable used for the test is of the 6-core shape shown in FIG. 1 , and is formed with an optical cable outer diameter of 8 mm, a mass of 55 kg / km, and a cable jacket thickness of 1.0 mm.

  The resin material (A to G) of the cable jacket of the optical cable used for the test is a resin mainly composed of a polyolefin resin and provided with flame retardancy. The coefficient (JISK7125) was changed. In addition, the tensile strength (JISK7113) and D hardness (JIS 7215) of the cable jacket were also changed with other additives, and the above dynamic friction coefficient, tensile strength, and D hardness of each jacket material were measured. .

The test optical cable was 10 m in length and housed in a wiring trough as shown in FIG. 4, and the middle optical cable was pulled out for verification.
As a result of the pull-out test, the optical cables of the jacket materials E to G having a dynamic friction coefficient in the range of 0.1 to 0.3 could be easily pulled out by human hands, but the dynamic friction coefficient was 0. The optical cables of the jacket materials A to D exceeding .3 could not be easily pulled out by human hands.

As for the sheath damage when the optical cable is pulled out, the outer sheath material A, B, E, or G of the optical cable having a tensile strength of 10 MPa or more was not torn, but the tensile strength was less than 10 MPa. For the optical cables of the outer sheath materials C, D, and F, the cable outer sheath was torn off.
In addition, for the optical cables of the jacket materials A, D, E, and F having a D jacket hardness of 55 or more, the inner optical fiber was not exposed, but the cable jacket D hardness was less than 55. For the optical cables of the jacket materials B, C, and G, the cable jacket was worn and the internal cable was exposed.

  From the verification results of FIG. 3, the cable jacket of the optical cable that can be easily removed by pulling out the inner optical cable in a state where a plurality of optical cables are bundled, has a dynamic friction coefficient of 0. .3 or less, hardness of 55 or more, and tensile strength of 10 MP or more are required. The jacket material E corresponds to all of the above conditions. Therefore, it is preferable to use a material close to the jacket material E as the cable jacket of the optical cable in the present invention.

  It should be noted that if the coefficient of dynamic friction is too small, roll-up is likely to occur due to winding onto a bobbin or the like, so it is desirable that the coefficient be 0.1 or more. In addition, since the rigidity of the cable jacket is too great and the workability is lowered, the hardness is set to 62 or less. Therefore, it is desirable that the pressure be 20 MPa or less.

DESCRIPTION OF SYMBOLS 1 ... Collective optical cable, 2 ... Optical fiber cord, 3 ... Core wire coating, 4 ... Optical fiber core wire, 5 ... High tension fiber, 6 ... Cord jacket, 7 ... Tension member, 7a ... Tensile wire, 7b ... Coating 8 ... Cable jacket , 10 ... Presser wound tape, 11 ... Tear string.

Claims (2)

A collective optical cable in which a plurality of optical fiber cords are assembled and covered with a cable jacket together with a tension member,
A tension member made of steel wire or fiber reinforced plastic is placed at the center, and a plurality of the optical fiber cords are twisted around it. It is wound in a circular cross section, the surface of the cable jacket has irregularities corresponding to the overlap of the presser winding tape, the convex width is formed larger than the concave width,
A collective optical cable having a dynamic friction coefficient (JIS K7125) of 0.3 or less, a hardness (JIS K7215) of 55 or more, and a tensile strength (JIS K7113) of 10 MPa or more. The cable jacket is formed by extrusion molding a resin material consisting mainly of polyethylene, the holding tape is aggregated cable according to claim 1, characterized in that it is bonded to the outside of the cable.

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