JP5798957B2 - Manufacturing method of optical fiber unit - Google Patents

Description

  The present invention relates to a method for manufacturing an optical fiber unit mounted on an optical fiber cable.

  In the access system optical fiber cable, an intermediate branching operation at an appropriate position is required for wiring to each subscriber, and identification of each optical fiber is required. Therefore, a plurality of optical fibers are bundled and integrated to form an optical fiber unit. Further, in order to identify each optical fiber unit, winding is performed by using an identification thread (bundling member) colored on the outer periphery of each optical fiber unit. It has been broken.

  And in order to improve the discriminability of each optical fiber unit, the method of giving a pattern to an identification thread | strain is proposed (for example, refer patent document 1). In addition, a technique for applying a knot, a ring, a flag, or the like to the identification thread has been proposed (see, for example, Patent Document 2).

JP 2007-010918 A JP 2007-010919 A

  However, the identification yarn wound around the optical fiber unit is easily unwound and may be difficult to distinguish from other optical fiber units.

  To improve this, a plurality of discriminating yarns made of resin are used to wrap around the optical fiber unit and heat-bond the intersections so that the discriminating yarns are not easily unraveled and light that improves discriminability during intermediate branching operations. A fiber unit structure is conceivable.

  In order to heat-bond the identification yarn, it is necessary to heat the identification yarn. As a result, the identification yarn made of resin contracts and compresses the optical fiber, resulting in an increase in transmission loss. There is a problem of significantly inhibiting sex.

  In order to avoid such an adverse effect due to heat shrinkage of the identification yarn, it is possible to release the distortion accumulated in the identification yarn by subjecting the identification yarn in advance, but the number of processing steps increases. There is a problem.

  In view of the above problems, an object of the present invention is to heat and shrink an identification yarn that bundles a plurality of optical fibers in an inline manner, and to release distortion accumulated in the identification yarn without increasing the number of processing steps. It is providing the manufacturing method of the optical fiber unit which can do.

  According to one aspect of the present invention, a plurality of optical fiber bundles travel in one direction, and each includes a high melting point member and a low melting point member that has a lower melting point than the high melting point member and covers the high melting point member. Unwinding the identification yarn of the book and winding it around a bundle of optical fibers so as to cross each other; heating the bundle of optical fibers wound with the identification yarn at a first temperature lower than the melting point of the low melting point member; Heating and shrinking the identification yarn by cooling the heated identification yarn, and heating the heated and shrunk identification yarn at a second temperature that is equal to or higher than the melting point of the low melting point member and lower than the melting point of the high melting point member. There is provided a method for manufacturing an optical fiber unit, including the step of heat-sealing the intersection of the identification yarns and the step of cooling the identification yarn that has been heat-sealed.

  In one aspect of the present invention, the step of heating the identification yarn at the first temperature is a step of bringing a bundle of optical fibers around which the identification yarn is wound into the first heating device, heating the bundle, and cooling the heated identification yarn May carry out the cooling of the bundle of optical fibers wound with the identification yarn from the first heating device.

  In one aspect of the present invention, the step of heating the identification yarn at the second temperature includes carrying a bundle of optical fibers in which the identification yarn is wound around a second heating device arranged in series with the first heating device. May be heated.

  In one aspect of the present invention, in the step of feeding out the plurality of identification yarns, the two identification yarns may be spirally wound around a bundle of optical fibers in opposite directions.

  According to the present invention, an identification fiber that bundles a plurality of optical fibers can be heated and shrunk in an in-line manner, and the strain accumulated in the identification thread can be released without increasing the number of processing steps. A method for manufacturing the unit can be provided.

It is sectional drawing which shows an example of the optical fiber cable which concerns on embodiment of this invention. It is a perspective view which shows an example of the optical fiber unit which concerns on embodiment of this invention. It is sectional drawing which shows an example of the identification thread | yarn which concerns on embodiment of this invention. It is a graph which shows the relationship between the heating time of the identification yarn which concerns on embodiment of this invention, and the distance between marked lines. It is the schematic which shows an example of the manufacturing system of the optical fiber unit which concerns on embodiment of this invention. It is the schematic for demonstrating an example of the sending device which concerns on embodiment of this invention. It is a graph which shows the relationship between the heating time of the identification yarn which concerns on embodiment and comparative example of this invention, and the distance between marked lines.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

(Structure of optical fiber cable)
As shown in FIG. 1, an optical fiber cable according to an embodiment of the present invention is a slotless optical fiber including a cable part 1, a neck part 2 connected to the cable part 1, and a support line part 3 connected to the neck part 2. It is a cable.

  The support wire portion 3 includes a support wire 18 extending in the cable longitudinal direction and an outer sheath (sheath) 17 that collectively covers the support wire 18. The cable unit 1 includes a plurality of optical fiber units 10 a to 10 j, a jacket (sheath) 13 that collectively covers the plurality of optical fiber units 10 a to 10 j, and a pair of tensile bodies (tensions) provided inside the jacket 13. Members) 15a and 15b.

  As shown in FIG. 2, the optical fiber unit 10a includes a plurality (20) of optical fibers 11 having a diameter of 0.5 mm and a plurality (two) of optical fibers 11 for bundling and integrating the plurality of optical fibers 11. Identification yarns (heat-bonding bunching yarns) 12a and 12b. The structures of the optical fiber units 10b to 10j shown in FIG. 1 also have the same structure as the optical fiber unit 10a.

  The number and kind of optical fibers 11 are not particularly limited. As the optical fiber 11 according to the embodiment of the present invention, a core wire such as an optical fiber strand, an optical fiber core wire, or an optical fiber tape core wire can be adopted.

  The identification yarns 12a and 12b are given unique colors so that they can be distinguished from the other optical fiber units 10b to 10j. The identification yarns 12a and 12b are spirally wound around the bundle of optical fibers 11 in opposite directions. At the intersection (cross bind portion) T of the identification yarns 12a and 12b, the identification yarns 12a and 12b are bonded to each other by heat fusion.

  The adhesive strength at the intersection T between the identification threads 12a and 12b is such that the identification threads 12a and 12b cannot be unintentionally unraveled and can be easily removed by hand. Therefore, it is possible to prevent the discrimination yarns 12a and 12b from being unintentionally unwound and impairing the discrimination between the optical fiber unit 10a and the other optical fiber units 10b to 10j. Furthermore, at the time of the intermediate post branching operation, the intersection T of the identification yarns 12a and 12b can be manually removed to widen the extraction portion, and the optical fiber 11 can be easily extracted.

  The pitch P between the intersections T of the identification yarns 12a and 12b is preferably 80 mm to 200 mm. The narrower the pitch P is less than 80 mm, the more difficult it is to take out the optical fiber 11 during the intermediate branching operation. On the other hand, the visibility of the identification yarns 12a and 12b becomes worse as the pitch P exceeds 200 mm.

  As shown in FIG. 3, the identification yarns 12 a and 12 b include a high melting point member 122 extending in the cable longitudinal direction and a low melting point member that covers the outer periphery of the high melting point member 122 and has a melting point lower than the melting point of the high melting point member 122. 121 is included. The difference between the melting point of the high melting point member 122 and the melting point of the low melting point member 121 is preferably at least about 20 ° C. The melting point of the high melting point member 122 is preferably about 160 ° C., and the melting point of the low melting point member 121 is preferably about 90 ° C. to 130 ° C. Further, the low melting point member 121 is required not to be bonded to the optical fiber 11 even when heated and melted, or to have a low adhesive force even when bonded, and not to deteriorate the outer layer of the optical fiber 11.

  Each of the high melting point member 122 and the low melting point member 121 includes, for example, a high melting point resin such as polyamide or polyethylene terephthalate (PET), polypropylene fiber, polyamide fiber (registered trademark nylon, aramid, etc.), polyester fiber (PET fiber). Etc.), or a thermoplastic resin capable of reversibly repeating softening and solidification by heating / cooling with respect to a high-melting fiber such as PET, polypropylene, etc., such as ethylene vinyl acetate copolymer (EVA) A so-called hot melt type (hot melt type) that has a low melting point such as ethylene ethyl acrylate copolymer (EEA) or a thermoplastic resin or rubber and can be repeatedly softened and solidified by heating and cooling. ) Covered with an adhesive can be used. One material is relatively the high melting point member 122 and the other material is the low melting point member 121 by the combination of the above materials.

  Here, when the identification yarns 12a and 12b are manufactured, distortion is accumulated in the identification yarns 12a and 12b. When the identification yarns 12a and 12b are heated (annealed), the distortion of the identification yarns 12a and 12b is released and heat shrinkage occurs after cooling. For example, as shown in FIG. 4, when the identification yarns 12a and 12b are heated at 80 ° C. for about 1 to 6 hours and then cooled, the lengths of the identification yarns 12a and 12b are reduced by about 2%.

  In this manner, with the strain accumulated in the identification yarns 12a and 12b, the optical fiber 11 is wound around a bundle and heated to heat-bond the intersection T of the identification yarns 12a and 12b, or a completed optical fiber. When a temperature characteristic test is performed on the cable, the identification yarns 12a and 12b are heated and shrunk, and the bundle of optical fibers 11 is tightened. As a result, there is a problem that compressive strain occurs in the optical fiber 11 and increases transmission loss, and the discriminability at the time of intermediate post-branching work is impaired.

  In addition, there is a problem that the number of steps increases when annealing is performed in advance to release the distortion accumulated in the identification yarns 12a and 12b after the identification yarns 12a and 12b are manufactured.

(Optical fiber cable manufacturing system)
Next, an example of an optical fiber cable manufacturing system according to an embodiment of the present invention will be described. As shown in FIG. 5, the optical fiber cable manufacturing system according to the embodiment of the present invention includes an identification yarn feeding device (flying payoff) 101, a first heating device 102, and a second heating device 103. This is an in-line system provided in series (in tandem).

  Each of the first heating device 102 and the second heating device 103 is supported by the support bases 104 and 105, respectively. The interval between the delivery device 101 and the first heating device 102 and the interval between the first heating device 102 and the second heating device 103 can be set as appropriate.

  For example, as shown in FIG. 6, the delivery device 101 includes tubular members (bobbins) 111a and 111b wound with identification threads 12a and 12b, and support portions 112a and 112b that can rotate around the centers of the bobbins 111a and 111b. The blade portions 113a and 113b are attached to the support portions 112a and 112b, and the feeding portions 114a and 114b are attached to the support portions 112a and 112b.

  A bundle of a plurality of optical fibers (hereinafter referred to as “fiber bundle”) 11x travels in a white arrow and sequentially passes through the central cavity of the bobbins 111a and 111b. The support part 112a rotates clockwise around the center of the bobbin 111a with respect to the traveling direction of the optical fiber bundle 11x. The support part 112b rotates about the center of the bobbin 111b counterclockwise with respect to the traveling direction of the optical fiber bundle 11x. The identification yarns 12a and 12b wound around the bobbins 111a and 111b are respectively fed through the openings of the blade portions 113a and 113b and the openings of the feeding portions 114a and 114b, and are wound around the optical fiber bundle 11x.

  Here, the feeding device 101 has a tension (possible possible) so that when the identification yarns 12a and 12b are heated and contracted in the first heating device 102 at the subsequent stage, the identification yarns 12a and 12b are further fed out by the heating and contracting amount. The identification yarns 12a and 12b are fed out with a tension close to no tension).

  As each of the first heating device 102 and the second heating device 103, for example, an electric furnace such as a Kanthal furnace, an electric heater, a hot air heating furnace, or the like can be used.

(Manufacturing method of optical fiber unit)
Next, an example of a manufacturing method of the optical fiber unit according to the embodiment of the present invention using the manufacturing system shown in FIG. 5 will be described with reference to FIGS. Here, the manufacturing process of the optical fiber unit 10a among the plurality of optical fiber units 10a to 10j will be described. However, the optical fiber units 10b to 10j can be simultaneously manufactured in parallel using the manufacturing system shown in FIG. is there.

  (A) In step S1, the delivery device 101 for the identification yarns 12a and 12b shown in FIG. 5 enters the fiber bundle 11x and is dragged to the fiber bundle 11x using the delivery device 101 as shown in FIG. The two identification threads 12a and 12b are fed out (sent out). The identification yarns 12a and 12b are wound around the fiber bundle 11x in a spiral shape in opposite directions. The identification yarns 12a and 12b intersect each other on the surface of the fiber bundle 11x and have an intersection point T. The identification yarns 12a and 12b are wound on the fiber bundle 11x, but their positions are not fixed. The fiber bundle 11x around which the identification yarns 12a and 12b are wound is carried into the first heating device 102 shown in FIG.

  (B) In step S2, by setting the inside of the furnace of the first heating device 102 to, for example, 230 ° C., the surface temperature of the fiber bundle 11x is set to a first temperature lower than the melting point of the low melting point member 121 (for example, 50 ° C.). Heat) (approx.). Thereby, the distortion accumulated in the identification yarns 12a and 12b is released.

  (C) In step S3, the fiber bundle 11x wound with the heated identification yarns 12a and 12b is unloaded from the first heating device 102 and naturally cooled. As a result, the identification yarns 12a and 12b are heated and contracted, and the slack is eliminated. At this time, the identification yarns 12a and 12b are further fed out from the delivery device 101 by the heat-shrinked length, and the identification yarns 12a and 12b do not tighten the fiber bundle 11x.

  (D) In step S4, the fiber bundle 11x around which the identification yarns 12a and 12b are wound is carried into the second heating device 103. By setting the inside of the furnace of the second heating device 103 to, for example, 300 ° C., the second temperature (the surface temperature of the fiber bundle 11x is equal to or higher than the melting point of the low melting point member 121 and lower than the melting point of the high melting point member 122). For example, it is heated to about 130 ° C to 140 ° C. As a result, the low melting point member 121 is melted and the intersection T of the identification yarns 12a and 12b is bonded by thermal fusion. On the other hand, since the high melting point member 122 does not melt, the shapes of the identification threads 12a and 12b are maintained.

  (E) In step S5, the optical fiber unit 10a around which the identification yarns 12a and 12b are wound is naturally cooled after passing through the second heating device 103. Thereby, the low melting point member 121 is solidified, and the bonding state of the intersection T of the identification threads 12a and 12b is maintained. As a result, the optical fiber unit 10a shown in FIG. 1 is completed. In addition, the optical fiber units 11b to 11j can be manufactured simultaneously in parallel with the optical fiber unit 10a.

  (F) After that, if a plurality of optical fiber units 10a to 10j are collectively covered with the outer sheath together with the support wire 18 by using a coating apparatus (not shown), the optical fiber cable shown in FIG. 1 is completed.

  According to the method of manufacturing an optical fiber unit according to the embodiment of the present invention, the identification yarns 12a and 12b are heated and contracted in advance in steps S2 and S3 before the identification yarns 12a and 12b are thermally fused in step S4. Therefore, the identification yarns 12a and 12b are not heat-shrinked at the time of heat-sealing the identification yarns 12a and 12b in step S4 or a temperature characteristic test after completion of the optical fiber cable, and the fiber bundle 11x is not tightened. Therefore, it is possible to prevent the optical fiber 11 from being subjected to compressive strain or impairing the discriminability of the intermediate branching operation.

  Furthermore, since the processing of steps S1 to S5 is performed in-line in series (in tandem), the number of processing steps is not increased as compared with the case where the processing is performed after annealing is performed in advance after manufacturing the identification yarn. The identification yarns 12a and 12b can be heated and shrunk, and the strain accumulated therein can be released (relaxed).

  FIG. 7 shows the identification yarns 12a and 12b according to the embodiment of the present invention, in which the identification yarn is wrapped around the optical fiber unit after being heated and shrunk in an in-line method, and as a comparative example, the optical fiber unit is identified without being annealed in advance. The identification yarn of the one wound with the yarn is taken out, heated at 80 ° C., cooled, and heat-shrinked. In the comparative example, the heat shrinkage is about 2% by heating for about 1 to 6 hours, whereas the identification yarns 12a and 12b according to the embodiment of the present invention have a small amount of heat shrinkage.

(Other embodiments)
As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  As an optical fiber cable according to an embodiment of the present invention, a slotless optical fiber cable is shown in FIG. 1, but the type of optical fiber cable is not particularly limited as long as it has an optical fiber unit. For example, the present invention can be applied to a slot type optical fiber cable such as an SZ slot type optical fiber cable or a tape slot type optical fiber cable.

  In addition, as the identification yarns 12a and 12b according to the embodiment of the present invention, a string-like structure in which a plurality of high melting point members 122 are collectively covered with low melting point members 121 as shown in FIG. There is no particular limitation. For example, a double structure in which the outer periphery of one high melting point member is covered with a low melting point member may be used. Further, the high melting point member may be a tape shape or a film shape, and the high melting point member may be covered with the low melting point member. Moreover, the structure which twisted two or more things of the double structure which coat | covered the outer periphery of a high melting point member with the low melting point member may be sufficient.

  Although the case where the two identification yarns 12a and 12b are spirally wound around the fiber bundle 11x in the reverse direction has been described, the number and the winding method of the identification yarns are not particularly limited as long as they can be wound so as to have intersections. For example, one identification thread may be wound spirally and another identification thread may be vertically attached in a straight line. In addition, two identification threads may be spirally wound in opposite directions, and another identification thread may be linearly attached vertically.

  In the optical fiber unit manufacturing method according to the embodiment of the present invention, the case where the identification yarns 12a and 12b are wound around the fiber bundle 11x in step S1 has been described. However, in step S1, the identification yarns 12a and 12b are wound on the fiber bundle 11x. The identification yarns 12a and 12b may be wound around the fiber bundle 11x in either step S2 or S3. Further, after the identification yarns 12a and 12b heated and shrunk in step S4 are carried into the second heating device 103 and before the surface temperature of the fiber bundle 11x reaches the second temperature at which heat fusion can be performed, the heat shrunk discrimination is performed. The yarns 12a and 12b may be wound around the fiber bundle 11x.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Cable part 2 ... Neck part 3 ... Support line part 10 ... Optical fiber unit 11 ... Optical fiber 11x ... Fiber bundle 12a, 12b ... Identification thread 13, 17 ... Jacket | cover 15a, 15b ... Strength member 18 ... Support line 101 ... Sending out Apparatus 111a, 111b ... Tubular member (bobbin)
DESCRIPTION OF SYMBOLS 112a, 112b ... Support part 113a, 113b ... Blade | wing part 114a, 114b ... Feed-out part 102 ... 1st heating apparatus 103 ... 2nd heating apparatus 104, 105 ... Support stand 121 ... Low melting point member 122 ... High melting point member

Claims (4)

A plurality of optical fiber bundles are run in one direction, and a plurality of identification yarns each including a high melting point member and a low melting point member having a lower melting point than the high melting point member and covering the high melting point member are fed out. Step and
Winding the plurality of identification threads around the bundle of optical fibers so as to cross each other;
Heating the bundle of optical fibers wound with the identification yarn at a first temperature lower than the melting point of the low melting point member;
Heating and shrinking the identification yarn by cooling the heated identification yarn;
Heating the shrinking identification yarn at a second temperature that is equal to or higher than the melting point of the low melting point member and lower than the melting point of the high melting point member, thereby fusing the intersection of the identification yarns;
Cooling the thermally fused identification yarn ;
Only including,
The step of unwinding the plurality of identification yarns is performed by applying the plurality of identification yarns with a tension smaller than the heat shrinkage force so that when the plurality of identification yarns are heated and contracted, the number of the identification yarns is further unwound. A method of manufacturing an optical fiber unit, wherein the optical fiber unit is extended . The step of heating the identification yarn at the first temperature is carried by heating a bundle of optical fibers around which the identification yarn is wound around a first heating device,
2. The optical fiber unit according to claim 1, wherein in the step of cooling the heated identification yarn, the bundle of optical fibers wound with the identification yarn is unloaded from the first heating device and cooled. Production method.   The step of heating the identification yarn at the second temperature includes heating the bundle of optical fibers around which the identification yarn is wound around a second heating device arranged in series with the first heating device. The manufacturing method of the optical fiber unit of Claim 2 characterized by the above-mentioned.   The optical fiber according to any one of claims 1 to 3, wherein in the step of feeding out the plurality of identification yarns, the two identification yarns are spirally wound around the bundle of optical fibers in opposite directions. Unit manufacturing method.

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