JP2017037214A - Optical cable and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical cable that is formed such that tearing operation of a sheath is reliably and easily performed, and to provide a method of manufacturing the same.SOLUTION: In an optical cable, a sheath 30 is provided on an outer periphery of a cable core 10 in which optical fiber ribbons 14 formed, for example, in a tape member shape with plural coated optical fibers are housed. On an outer periphery side of the cable core 10, sheath tearing strings 20 are longitudinally attached in a lengthwise direction while being made to be substantially in contact with the cable core 10, and also tape members 21 each are longitudinally attached on an outer side of the sheath tearing strings 20 in a radial direction of the optical cable. Consequently, resin forming the sheath is prevented from intruding between the sheath tearing strings 20 and the cable core 10 at the time of sheath forming.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical cable and a manufacturing method thereof, and more particularly to an optical cable in which a jacket tear string is arranged between a cable core and a jacket and a manufacturing method thereof.

  In addition to increasing the communication speed and the amount of information due to the spread of information communication such as the Internet, the construction of optical networks is progressing to support bidirectional communication and large-capacity communication. In this optical network, FTTH (Fiber To The Home), which provides a high-speed communication service by directly connecting a communication carrier and each home with an optical fiber, has been started. For this reason, the demand for wiring work distributed to a plurality of homes is increasing.

  In wiring work, it is necessary to branch an optical fiber core housed in an optical cable. For example, as disclosed in Patent Documents 1 and 2, an optical cable has an aramid fiber for the purpose of easily removing the jacket. In general, a structure in which a PET string is vertically attached between a cable core and a jacket and can be used as a jacket tearing string of the jacket.

  For example, a slot type optical cable as shown in FIG. 5 has a resin-made slot rod 101 in which a tension member 102 is embedded and integrated at the center. Then, four optical fiber tape cores 104 are stacked and bundled, stored in the plurality of storage grooves 103 of the slot rod 101, and held by the upper tape member 105, thereby forming the cable core 100. Yes. A jacket (also referred to as a sheath) 130 is formed on the outer periphery of the cable core 100 with the jacket tear string 120 vertically attached.

  This optical cable is formed by extruding the jacket resin around the cable core 100 while vertically attaching the jacket tear string 120 on the cable core 100 because of the position where the jacket tear string 120 is inserted. Is done.

JP 2014-119524 A JP 2012-173398 A

  The jacket tear string 120 needs to be provided so that the jacket 130 can be surely torn so that the jacket 130 does not remain partially on the cable core 100. For this reason, it is desirable that the outer jacket tear string 120 is fixed on the lower side of the outer jacket 130, that is, in a state in contact with the cable core 100. However, the jacket tear string 120 may occasionally float during the manufacturing process. When the jacket tear string 120 is lifted, as shown in FIG. 6, the jacket resin wraps around the jacket tear string 120 toward the cable core 100, so that the jacket tear string 120 and the cable core 10 are covered with each other. In some cases, 130 resin A enters, and the jacket tear string 120 is located in the jacket 130.

  When the jacket tear string 120 is located in the jacket 130, even if the jacket 130 is torn, the resin A of the jacket 130 remains on the outer periphery of the cable core 100 at that location, so that the remaining resin A is removed. Is required. Further, in order to take out the jacket tear string 120, it is necessary to cut the jacket 130 with a tool having a blade up to the outer peripheral portion of the cable core 100. At that time, the jacket tear string 120 is in the jacket 130. Then, there occurs a situation in which the blade of the tool cuts the jacket tear string 120 located in the jacket 130 and the jacket tear string 120 cannot be taken out.

  For this reason, it is required to strictly control the jacket tear string so that it is not embedded in the jacket. However, the jacket tear string 120 is kept in contact with the cable core 100 over the entire length, and the jacket tear string at a high linear velocity. It is difficult to extrude the resin 130. For this reason, it is difficult to increase the manufacturing speed, which is one factor that hinders improvement in productivity.

  The present invention has been made in view of such a situation, and by taking a structure in which the resin of the outer jacket does not wrap around between the outer jacket tear string and the cable core, the outer jacket tear string is attached to the cable core. An object of the present invention is to provide an optical cable which is brought into close contact with the outer periphery and can reliably and easily perform an outer tearing operation and a method for manufacturing the optical cable.

  An optical cable according to the present invention is an optical cable in which an outer periphery of a cable core that houses a plurality of optical fiber cores is coated with an outer sheath resin, and an outer jacket tear string is vertically attached to the outer peripheral side of the cable core. In addition, a tape member is vertically attached to the outer side of the jacket tear string in the optical cable radial direction.

  An optical cable manufacturing method according to the present invention is an optical cable manufacturing method in which an outer periphery of a cable core containing a plurality of optical fiber cores is coated with an outer casing resin by extrusion molding, the outer casing resin extrusion molding In this case, the jacket tear string is vertically attached to the outer peripheral side of the cable core, and the jacket resin is extruded in a state where the tape member is vertically attached to the outer side of the optical fiber cable in the optical cable radial direction. Yes.

  According to the present invention, since it has a structure in which the resin of the jacket does not wrap around the cable core side of the jacket tear string, the jacket tear string can be brought into close contact with the outer periphery of the cable core, and the jacket tearing work can be reliably performed. And it becomes easy to do.

It is sectional drawing which shows one structural example of the optical cable which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows another structural example of the optical cable which concerns on the 2nd Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing process of the optical cable which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows one structural example of the optical cable which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows one structural example of the optical cable which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the example of 1 structure of the conventional optical cable. In the conventional optical cable, it is sectional drawing which shows the state which has a jacket tear string in a jacket.

First, embodiments of the present invention will be listed and described.
The optical cable of the present application is (1) an optical cable in which an outer periphery of a cable core containing a plurality of optical fiber cores is covered with an outer sheath resin, and an outer jacket tear string is vertically attached to the outer peripheral side of the cable core. And an optical cable in which a tape member is vertically attached to the outer side of the outer tear cable in the radial direction of the optical cable. Since the tape member is vertically attached to the outer side of the optical fiber cable of the outer tear cable, the resin of the outer cable does not go around between the outer tear cable and the cable core when forming the outer cable. The string can be brought into close contact with the outer periphery of the cable core, and the jacket tearing operation can be performed reliably and easily.

  (2) In the optical cable of the above (1), it is desirable that the tape member is bent so as to have a shape covering the outer tear string. Thereby, it can prevent more reliably that resin of a jacket turns around between a jacket tear string and a cable core.

  (3) In the optical cable of (1), the tape member may be provided on the outer periphery of the jacket tear string in a melted and solidified state. As a result, when the jacket is formed, the tape member melts and is positioned on the outer periphery of the jacket tear string, and also closely adheres to the cable core, so that the resin of the jacket wraps around between the jacket tear string and the cable core. It can prevent more reliably.

  The optical cable manufacturing method of the present application is (4) an optical cable manufacturing method in which an outer periphery of a cable core containing a plurality of optical fiber cores is coated with an outer casing resin by extrusion molding, and the outer casing resin extrusion molding In this case, an optical cable that pushes out the jacket resin in a state in which a jacket tear string is vertically attached to the outer peripheral side of the cable core and a tape member is vertically attached to the outer side of the optical fiber cable in the radial direction of the optical cable. It is a manufacturing method. Because the tape member is vertically attached to the outer side of the optical fiber cable of the outer tear cable, the resin of the outer cable does not wrap around between the outer tear cable and the cable core when forming the outer cable. The string can be brought into close contact with the outer periphery of the cable core, and the jacket tearing operation can be reliably and easily performed.

  In the optical cable manufacturing method of (4) above, the tape member has a melting point lower than the extrusion temperature of the jacket resin, and the tape member is welded to the outer circumference of the jacket tear string during extrusion molding of the jacket resin. You may let them. As a result, since the tape member melts and is positioned on the outer periphery of the jacket tear string when the jacket is formed, it is possible to more reliably prevent the resin of the jacket from flowing around between the jacket tear string and the cable core. it can.

(Details of the embodiment of the present invention)
Specific examples of the optical cable and the manufacturing method thereof according to the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes are included within the meaning and range equivalent to the claim. In the following description, the configurations denoted by the same reference numerals in different drawings are the same, and the description thereof may be omitted.

(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration example of an optical cable according to the first embodiment of the present invention.
The optical cable of this embodiment is a slot-type optical cable, and has a resin-made slot rod 11 in which a tension member 12 is embedded and integrated at the center. A plurality of storage grooves 13 are formed in the slot rod 11. The storage grooves 13 have a bottom surface on the tension member 12 side, are arranged at substantially equal intervals along the circumferential direction of the slot rod 11, and the adjacent storage grooves 13 are separated by ribs. The slot rod 11 is provided with a notch 16 for marking on the outer peripheral portion of the rib so that the position of the storage groove 13 can be identified.

  The storage groove 13 is formed in a spiral or SZ shape along the longitudinal direction of the optical cable. For example, four optical fiber ribbons 14 are stacked and bundled, and the outer periphery of the storage groove 13 is an upper winding tape member 15. Thus, the cable core 10 of the present invention is configured. The optical fiber ribbon 14 is obtained by bundling several optical fibers in a tape shape. A presser winding member may be further provided on the outer periphery of the upper winding tape member 15.

  On the outer peripheral side of the cable core 10, a jacket tear string 20 is vertically attached along the longitudinal direction of the cable core 100 while being substantially in contact with the cable core 10, and the optical fiber radial direction of the jacket tear string 20 A jacket 30 is formed with the tape member 21 vertically attached to the outside. The jacket 30 is formed by extruding a jacket resin around the cable core 10 at a high temperature and in a molten state at the time of extrusion forming. At that time, the jacket tear string 20 and the tape member 21 are also covered with the jacket 30 and fixed to the cable core 10 when the jacket 30 is extruded. The jacket 30 is made of a thermoplastic resin such as an olefin resin (for example, polyethylene). The jacket tear string 20 is for tearing the jacket 30 and is composed of fibers such as aramid fiber and polyester.

As a material of the tape member 21, for example, a tape member made of a material (for example, PET) that is not easily melted at the molding temperature of the jacket resin can be used. The tape member 21 can prevent the jacket resin from wrapping between the jacket tear string 20 and the cable core 10, so that the tear string is not buried in the jacket resin during extrusion molding of the jacket resin. For this reason, the jacket tear string 20 can be vertically attached while being in contact with the outer peripheral surface of the cable core 10.
Further, if the width of the tape member 21 is increased, the path through which the jacket resin enters the jacket tear string 20 can be lengthened, and the wraparound of the jacket resin can be suppressed more reliably.

(Second Embodiment)
FIG. 2 is a sectional view showing another configuration example of the optical cable according to the second embodiment of the present invention.
The optical cable according to the present embodiment is the same as the first embodiment except that the shape of the tape member is different from that of the first embodiment. The optical cable of the present embodiment is provided with a tape member 22 that is bent so as to cover the jacket tear string 20 on the outer side in the optical cable radial direction of the jacket tear string 20. For this reason, at the time of extrusion molding of the jacket resin, it is possible to reliably avoid the jacket resin from wrapping around between the jacket tear string 20 and the cable core 10 and to prevent the tear string from being buried in the jacket resin. Increases the effect.

(Third embodiment)
FIG. 3A is a cross-sectional view for explaining a manufacturing process of the optical cable according to the third embodiment of the present invention, and FIG. 3B is a cross-sectional view showing a configuration example of the optical cable according to the third embodiment of the present invention. FIG.
The optical cable of this embodiment is different from the first embodiment or the second embodiment only in that the material of the tape member is changed, and the other configurations are the same. Is omitted. The optical cable of the present embodiment is made of a thermoplastic resin such as low melting point nylon, which is melted by heat at the time of extrusion molding of the outer cover, as a material of the tape member 23 vertically attached to the outer side of the torn string 20 in the optical cable radial direction. This material is used.

  For this reason, immediately after extrusion formation, as shown in FIG. 3A, the tape member 23 vertically attached to the outer side of the outer tear cable 20 in the optical cable radial direction melts because the extrusion temperature at the time of extrusion is higher than its melting point, It is fixed to the cable core 10 in a state of being melted and solidified on the outer periphery of the jacket tear string 20. For this reason, it is possible to avoid that the jacket resin wraps around between the cable core 10 and the jacket tear string 20 during extrusion molding of the jacket, and the molten tape member including the jacket tear string 20 is brought into contact with the cable core 10. It can be fixed in the state. In addition, since the melted and solidified tape member 23 is also bonded to the upper tape member 15 of the cable core 10, the upper tape member 15 can be broken when the outer jacket 30 is torn by the outer jacket tear string 20. The fiber ribbon 14 can be easily taken out.

(Fourth embodiment)
FIG. 4 is a cross-sectional view showing a configuration example of an optical cable according to the fourth embodiment of the present invention.
The optical cable of the present embodiment is a slotless type optical cable. Six optical fiber tape cores 14 of 4 cores are laminated and bundled to form 24 cores, and the outside is covered with, for example, polypropylene yarn made of fiber bundles. The cable core 10 'is configured by protecting the fiber core wire or forming a buffer layer 17, pressing the outer periphery thereof with the upper winding tape member 15, and further pressing the outer periphery with a presser winding member (not shown). As the upper tape member 15, a nonwoven fabric such as a polyester fiber is usually used, and either a spirally wound form or a vertically wound form may be used. In the present embodiment, the four optical fiber ribbons 14 are used, but a bundle of a plurality of single optical fiber cores may be used.

  On the outer peripheral side of the cable core 10 ′, as in the first embodiment, a jacket tear string 20 is vertically attached along the longitudinal direction of the cable core 10 ′ in a state of being substantially in contact with the cable core 10 ′. At the same time, a jacket 30 is formed in a state where a tape member 21 is vertically attached to the outer side of the jacket tear string 20 in the radial direction of the optical cable. The jacket 30 is formed by extruding a jacket resin around the cable core 10 'at a high temperature and in a molten state during extrusion forming. At that time, the jacket tear string 20 and the tape member 21 are also covered with the jacket 30 and fixed to the cable core 10 ′ when the jacket 30 is extruded. Since other configurations are the same as those in the first embodiment, the description thereof is omitted.

  Note that the slotless optical cable shown in the fourth embodiment is also bent so that the shape of the tape member covers the jacket tear string 20 as in the second embodiment. Further, as in the third embodiment, a tape member having a melting point lower than the extrusion temperature of the jacket resin may be used as the material of the tape member.

10, 10 ', 100 ... cable core, 11, 101 ... slot rod, 12, 102 ... tension member, 13, 103 ... storage groove, 14, 104 ... optical fiber tape core wire, 15, 105 ... upper winding tape member, 16 ... notches, 17 ... buffer layer, 20, 120 ... jacket tear string, 21, 22, 23 ... tape member, 30, 130 ... jacket.

Claims (5)

  An optical cable in which an outer periphery of a cable core containing a plurality of optical fiber cores is coated with a jacket resin, and a jacket tear string is vertically attached to the outer peripheral side of the cable core, and the jacket tear string An optical cable in which a tape member is vertically attached to the outside in the radial direction of the optical cable.   The optical cable according to claim 1, wherein the tape member is bent so as to have a shape covering the jacket tear string.   The optical cable according to claim 1, wherein the tape member is provided on an outer periphery of the jacket tear string in a melted and solidified state.   A method for manufacturing an optical cable in which a sheath resin is coated on an outer periphery of a cable core containing a plurality of optical fiber cores by extrusion molding, and the outer periphery of the cable core is disposed on the outer periphery of the cable core during extrusion molding An optical cable manufacturing method for extruding the jacket resin in a state where a jacket member is longitudinally attached and a tape member is vertically attached to the outer side of the outer tear cable in the radial direction of the optical cable. The optical cable manufacturing method according to claim 4, wherein the tape member has a melting point lower than an extrusion temperature of the jacket resin, and the tape member is welded to an outer periphery of the jacket tear string during extrusion molding of the jacket resin. Method.

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