JP6133123B2 - Optical fiber unit - Google Patents

Description

  The present invention relates to an optical fiber unit or the like excellent in branching workability.

  As the amount of information has increased in recent years, it is hoped that the amount of information transmitted in a single optical fiber cable will increase, that is, the optical fibers will be housed in high density in the optical fiber cable, and the number of optical fibers will be increased. It is rare. When the number of the storage cores increases, it becomes difficult to specify the optical fiber core wires, and therefore, a method of bundling a plurality of optical fiber core wires to facilitate identification is used. Such a bundle of a plurality of optical fiber core wires is referred to as an optical fiber unit. At the time of use, a necessary optical fiber core wire is taken out from such an optical fiber unit and branched.

  As such an optical fiber unit, for example, there is one in which a plurality of optical fiber core wires are formed by spirally winding two strings that are bundle materials in opposite directions (Patent Document 1).

Japanese Patent Laid-Open No. 9-26534

  On the other hand, such an optical fiber unit is usually used with its outer periphery covered with a jacket. For example, a buffer layer is provided on the outer periphery of the optical fiber unit, and the outer cover is extruded and covered. At this time, the bundle material constituting the optical fiber unit may be thermally contracted when the outer casing is extruded.

  As described above, the bundle material is spirally wound around the outer periphery of the optical fiber core wire. Accordingly, when the bundle material is thermally contracted in this state, the inner optical fiber core wire is strongly tightened. In such a state, for example, it becomes difficult to take out a desired optical fiber core wire from the bundle material during a branching operation.

  The present invention has been made in view of such a problem, and an object thereof is to provide an optical fiber unit or the like excellent in branching workability.

In order to achieve the above-mentioned object, a first invention is an optical fiber unit in which a plurality of optical fiber cores are bundled, and a plurality of optical fibers in which a plurality of optical fiber optical cores are intermittently bonded. A bundle member spirally wound around the outer periphery of the fiber tape core wire , wherein the bundle member has a heat shrinkage rate of 1.03% or less.

  According to the first invention, the optical fiber core wire can be held by the bundle material. In addition, the heat shrinkage of the bundle material is small even at high temperatures such as when the outer casing is extruded. For this reason, the inner optical fiber core wire is not excessively tightened by the bundle material. Therefore, it is easy to take out the optical fiber core wire from the optical fiber unit during the branching operation.

2nd invention is an optical fiber cable, Comprising: A some optical fiber core wire, The bundle material spirally wound by the outer periphery of the some optical fiber tape core wire to which the said optical fiber core wire was adhere | attached intermittently , A plurality of optical fiber units, a buffer layer provided on the outer periphery of the optical fiber unit, and a jacket provided on the outer periphery of the buffer layer, wherein the heat shrinkage rate of the bundle material is 1.03% or less It is an optical fiber cable characterized by being.

  According to the second invention, in the internal optical fiber unit, the optical fiber core wire is not excessively tightened by the bundle material, and an optical fiber cable excellent in branching workability can be obtained.

A third invention is an optical fiber cable manufacturing method in which a plurality of optical fiber core wires are bundled together and bundled, and a bundle material is spirally wound around the outer periphery of the intermittent tape core wires. A fiber unit is configured, and a plurality of the optical fiber units are coated with a resin on the outer periphery together with a buffer to form a coating portion, and the heat shrinkage rate of the bundle material due to heat at the time of forming the coating portion is 1.03%. It is the manufacturing method of the optical fiber cable characterized by the following.

  According to the third invention, in the internal optical fiber unit, the optical fiber core wire is not excessively tightened by the bundle material, and an optical fiber cable excellent in branching workability can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the optical fiber unit etc. which are excellent in branch workability | operativity can be provided.

The figure which shows the optical fiber unit 1. FIG. (A) is a figure which shows the optical fiber cable 10, (b) is a figure which shows the optical fiber cable 10a.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an optical fiber unit 1. The optical fiber unit 1 includes an optical fiber core wire 3, a bundle material 5, and the like.

  The optical fiber core wire 3 is, for example, a core wire having an outer diameter of 0.5 mm. A bundle material 5 is provided on the outer periphery of the plurality of optical fiber core wires 3. As the bundle material 5, for example, a resin tape such as polyester can be used. In the present invention, a resin that shrinks by heat is used as the bundle material 5.

  The bundle material 5 is spirally wound around the outer periphery of the plurality of optical fiber core wires 3. Alternatively, the optical fiber unit may be configured by spirally winding a pair of bundle members in opposite directions. In this case, the bundle members 5 intersect at a predetermined interval in the longitudinal direction of the optical fiber unit 1.

  In addition, the intersection part of bundle material 5 may mutually adhere | attach, and may just overlap | superpose without adhering. In any case, the bundle material 5 and the optical fiber core wire 3 are not bonded.

  Next, a method for manufacturing an optical fiber cable using the optical fiber unit 1 will be described. FIG. 2A is an example showing an optical fiber cable 10 formed using the optical fiber unit 1.

  First, a plurality of optical fiber core wires 3 supplied from the optical fiber core wire supply unit are bundled to form an optical fiber core wire bundle. Next, the bundle material 5 is spirally wound around the outer periphery of the optical fiber bundle. At this time, the bundle material 5 is wound around the outer periphery of the optical fiber core bundle with a certain amount of tension.

  The plurality of optical fiber units 1 thus obtained are twisted together, and a buffer body 11 such as polypropylene yarn is provided on the outer periphery thereof to form a cable core. Further, a covering portion 13 made of polyethylene or the like is formed by extrusion coating on the outer periphery of the obtained cable core together with the tension member 15 made of steel wire or the like and the tear string 17. Thus, the optical fiber cable 10 is formed.

  Here, when the coating portion 13 is extrusion-coated, heat is applied to the optical fiber unit 1. For example, when a resin such as polyethylene is extrusion-coated, heat of about 100 ° C. is applied to the optical fiber unit 1 through the buffer body 11. When heat is applied in this manner, the bundle material 5 constituting the optical fiber unit 1 is thermally contracted.

  When the bundle material 5 is thermally contracted, the optical fiber core wire bundle held by the bundle material 5 is strongly tightened. As described above, when the bundle of the optical fiber core wires is strongly tightened by the bundle material 5, the take-out property of the optical fiber core wire 3 is deteriorated. That is, in the case where the desired optical fiber core wire 3 is taken out from the inside of the optical fiber cable 10 and branched, it becomes difficult to take out the optical fiber core wire 3.

  Therefore, in the present invention, the heat shrinkage rate of the bundle material 5 is desirably 1.03% or less. When the thermal contraction rate of the bundle material 5 exceeds 1.03%, the bundle material 5 is thermally contracted, so that the inner optical fiber core wire 3 is excessively tightened and the take-out property is deteriorated.

  Note that the lower limit value of the heat shrinkage rate does not need to be set in particular. This is because the use of a special resin having a smaller heat shrinkage rate increases the cost.

  As an optical fiber cable using the optical fiber unit 1 of the present invention, in addition to the optical fiber cable 10 shown in FIG. 2A, for example, an optical fiber cable 10a using a slot shown in FIG. There may be.

  In the optical fiber cable 10a, the optical fiber units 1 are arranged in a plurality of slot grooves 21 formed on the outer periphery of the slot 19, respectively. The tension member 15 is provided substantially at the center of the slot 19, and the covering portion 13 is formed after pressing the outer periphery of the slot 19 as necessary.

  Even in this case, the same effect as that of the optical fiber cable 10 can be obtained. That is, if the heat shrinkage rate of the bundle material 5 is 1.03% or less, even if the bundle material 5 is thermally contracted by the heat when the coating portion 13 is extruded and coated, the take-out line of the optical fiber core wire 3 is provided. Can be secured.

  As described above, according to the present embodiment, the inner optical fiber core wire 3 can be reliably held by the wound bundle material 5. At this time, since the heat shrinkage of the bundle material 5 is 1.03% or less, the bundle material 5 is not excessively heat shrunk by the heat at the time of forming the covering portion 13.

  Therefore, the inner optical fiber core wire 3 is not excessively tightened by the bundle material 5. For this reason, it can suppress that the taking-out property of the optical fiber core wire 3 deteriorates.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  The optical fiber unit according to the present invention was evaluated. The product of the present invention is an optical fiber cable using the optical fiber unit shown in FIG. 1, and has substantially the same configuration as that shown in FIG. Specifically, an optical fiber unit was manufactured by bundling five optical fiber tape core wires each having an optical fiber core wire of 0.25 mmφ bonded intermittently and winding a bundle material having a width of 2.0 mm.

  As the bundle material, the evaluation was performed by selecting the material such as polyethylene terephthalate or polyethylene, adjusting the stretch amount, the aging time, and the like, and changing the heat shrinkage rate to a plurality of levels. The heat shrinkage rate of the bundle material was calculated from an initial length and a length after shrinkage by holding a test piece having a length of 10 cm in an oven at 100 ° C. for 10 minutes.

  The heat shrinkage rate of the bundle material was evaluated at 100 ° C. × 10 minutes. However, if the resin is normally used as a bundle material, the heat shrinkage rate is 100 ° C. or higher and heated in a temperature range below the softening point temperature. Even so, there was little further contraction. Further, even when the heating and holding time was extended, there was almost no further shrinkage. That is, the heat shrinkage rate due to heating at 100 ° C. for 10 minutes can be considered as a specific maximum heat shrinkage rate of the material.

  An optical fiber cable was manufactured by the method described above using various bundle materials. The coating part of the obtained optical fiber cable was peeled off, and it was evaluated whether any optical fiber core wire could be easily taken out from the internal optical fiber unit.

  The results are shown in Table 1. In the present example, when the thermal shrinkage rate exceeded 1.03%, there was a case where the inner optical fiber core was bent outward from the bundle material. In this example, evaluation was made by excluding those in which the optical fiber core wire was bent and jumped out of the bundle material. That is, the optical fiber core wire was evaluated as being securely held by the bundle material.

  In the “operability of taking out optical fiber core” in the table, “◯” indicates that any optical fiber core can be reliably separated and taken out at one time. In addition, “×” indicates that it is difficult to take out only one optical fiber, and it is difficult to take out a plurality of optical fibers at a time or to remove only a desired optical fiber. Indicates what was needed.

  From the results, when the heat shrinkage rate was 2.87% or more, the tightening force of the optical fiber core wire by the bundle material was too large, and thus the desired optical fiber core wire could not be taken out.

  On the other hand, when the thermal contraction rate is 1.03% or less, it is easy to take out any optical fiber core wire. That is, when the heat shrinkage rate is 1.03% or less, the heat shrinkage amount of the bundle material is small at the time of extruding the covering portion, and the tightening of the optical fiber core wire due to this is weak. Met.

DESCRIPTION OF SYMBOLS 1 ......... Optical fiber unit 3 ... Optical fiber core wire 5 ... Bundle material 10, 10a ... Optical fiber cable 11 ... Buffer body 13 ... Covering part 15 ... Tension member 17 ... …… Tear string 19 ……… Slot 21 ……… Slot groove

Claims (3)

An optical fiber unit in which a plurality of fiber cores are bundled,
A plurality of optical fiber cores;
A bundle material spirally wound around the outer periphery of a plurality of optical fiber ribbons to which the optical fiber cores are intermittently bonded ;
Comprising
An optical fiber unit, wherein the bundle material has a heat shrinkage rate of 1.03% or less. An optical fiber cable,
A plurality of optical fiber cores;
A bundle material spirally wound around the outer periphery of a plurality of optical fiber ribbons to which the optical fiber cores are intermittently bonded ;
A plurality of optical fiber units having:
A buffer layer provided on the outer periphery of the optical fiber unit;
A jacket provided on the outer periphery of the buffer layer;
And the bundle material has a heat shrinkage rate of 1.03% or less. A method of manufacturing an optical fiber cable,
A plurality of optical fiber cores are bundled together, and an optical fiber unit is configured by spirally winding a bundle material on the outer periphery of the intermittent tape core wires ,
Extrusion-coating resin on the outer periphery of the plurality of optical fiber units together with the buffer body to form a coating portion
The method of manufacturing an optical fiber cable, wherein a heat shrinkage rate of the bundle material due to heat at the time of forming the covering portion is 1.03% or less.

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