JP3467386B2 - Optical cable manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for producing an optical cable that having a plurality of sets optical fiber therein.

[0002]

2. Description of the Related Art As an optical cable, Japanese Patent Laid-Open No. 5-938
The one described in Japanese Patent No. 29 is known. Japanese Patent Laid-Open No. 5-
The optical cable described in Japanese Patent No. 93829 has a spacer having a U-shaped cross section arranged in alignment around a core material (tension member) located at the center of the inside thereof, and the optical fiber core wire is housed in the spacer. A tensile strength member is embedded in the spacer of the optical cable to effectively counter the tension applied to the spacer when the optical cable is manufactured.

Further, in such an optical cable, in order to prevent breakage of the optical fiber even when the optical cable is stretched, and to reduce the force applied to the optical fiber when the optical cable is bent. The spacers are arranged around the core material in a spirally twisted state (so-called S twist or Z twist) or in a meandering twisted state (so-called SZ twist).

[0004]

However, since the rigidity is increased by the strength member in the spacer, the SZ
There has been a problem that the spacer is hindered from being deformed when it is twisted, so that it is difficult to twist. Also, when the spacer is twisted into an SZ twist or the like, the side wall of the spacer falls toward the optical fiber core side in an attempt to maintain its shape, and the optical fiber core line is pressed to bend the optical fiber core line excessively. However, there is a problem in that the transmission characteristics may be adversely affected.

Further, since the rigidity of the spacer is increased, the work of taking out the optical fiber core wire at the end of the optical cable or the work of taking out the optical fiber core wire at the middle part of the optical cable (so-called intermediate post-branching work) is performed. However, there is a problem that the spacers are difficult to handle because the spacers bounce and the side wall portions of the spacers that fall to the optical fiber core side interfere with the extraction of the optical fiber core wire.

It is therefore an object of the present invention is to provide a method for manufacturing an optical cable that have a handling property is good, and good transmission characteristics.

[0007]

According to the method of manufacturing an optical cable of the present invention, an optical fiber core wire is housed inside a long spacer to form a spacer unit, and the spacer unit is aligned around the core material. The method for manufacturing an optical cable is characterized in that the tensile strength members arranged along the longitudinal direction of the spacer are removed from the spacer before the spacer units are aligned around the core material.

According to the present invention, at the time of manufacturing the spacer unit, the tensile force applied to the spacer can be effectively counteracted by causing the tensile strength member incorporated in the spacer to bear the tension, and the spacer can be fed out at high speed and stably. The manufacturing efficiency of the unit can be improved. As a result, the manufacturing efficiency of the optical cable can also be improved. Further, when the spacer units are aligned around the core material, the strength of the spacers is reduced by removing the strength members provided in the spacers, so that the spacer units can be flexibly deformed and easily aligned. it can.

Here, the removal of the tensile strength member from the spacer is carried out until the optical fiber core wire and the spacer are supplied so that the optical fiber core wire is housed inside the spacer and wound up as a spacer unit on the unit winding bobbin. It is preferable to carry out. By doing so, it is possible to smoothly remove the strength member during the process of manufacturing the spacer unit. As a result, it is not necessary to provide a new step for removing the strength member, and the manufacturing cost of the optical cable can be reduced.

Further, it is preferable that the optical fiber core wire is housed inside the spacer while tension is applied to the spacer by the unit pulling means, and the tensile strength member is removed from the spacer after passing through the unit pulling means. . By doing so, in the section where tension is applied to the spacer before passing through the unit tension means, it is possible to prevent the extension of the spacer by applying the tension to the tensile member provided and preventing the spacer from expanding. It becomes easy to match the length with the optical fiber core to be stored. If the spacer seems to easily expand due to the applied tension, there will be a difference in the length before and after the tension is applied, and there will be a difference in the length with the optical fiber core wire housed inside. Although it will occur, this can be prevented by disposing a strength member. After passing through the unit pulling means, no large tension is applied to the spacer,
It is possible to remove the tensile strength member which is a hindrance when the spacer units are aligned with the core member to facilitate the alignment of the spacer units and to prevent the transmission characteristics from being adversely affected.

Further, it is preferable to remove the strength member from the spacer while winding the strength member. By doing so, the wound strength member can be reused when the spacer is manufactured, and the material cost is reduced. The reduction can reduce the manufacturing cost of the optical cable.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A method of manufacturing an optical cable according to the present invention.
Embodiments of the method will be described with reference to the drawings.

As shown in FIG. 1, a core material 1 is arranged at the center of the optical cable C. The core material 1 is configured by forming a polyethylene coating 1b around the steel stranded wire 1a, and plays a role of counteracting the tension applied to the entire optical cable C. Spacer units 2 are aligned around the core material 1. As shown in FIG. 2, the spacer units 2 are arranged so as to meander around the core material 1.

The spacer unit 2 arranged in alignment around the core material 1 is a unit in which tape-shaped optical fiber core wires 21 are stacked and housed inside the spacer 20. The spacer 20 has side walls 20b (see FIG. 3).
(See reference), the tensile strength body accommodating grooves 20a are formed on the outer surface of the core material 1 and aligned. During the manufacturing process of the spacer unit 2, the strength members 22 accommodated in the strength member housing grooves 20a are removed, and when the spacer units 2 are aligned around the core material 1, as shown in FIG. On the outer surface of 20, a tensile strength body accommodating groove 20a is exposed.

FIG. 3 is a cross-sectional view of the spacer 20 before the strength member 22 is removed. The spacer 20 is a long member having a U-shaped cross section, which is manufactured by extrusion molding polybutylene terephthalate (PBT). The spacer 20 is composed of both side wall portions 20b and a bottom wall portion 20c, and a recess 20d is formed inward of these. The height of the spacer 20 is 5.0 m.
m, outer width of upper end is 6.6 mm, outer width of lower end is 5.0 mm
The internal recess 20d has a depth of 4.5 mm, an upper end inner width of 4.6 mm, and a bottom inner width of 3.
It is set to 5 mm.

The above-described groove 20a for receiving a strength member is formed on the outer surface of each side wall portion 20b of the spacer 20, and the strength member 2 is inserted in the groove 20a for holding a strength member.
2 is detachably built in. As the tensile strength member 22, 1140 d (denier) Kevlar (registered trademark of DuPont) is used, and in addition to Kevlar, it is made of a material such as polybenzbisoxide (PBO), nylon, polypropylene, cotton, or polyethylene terephthalate. In particular, it is preferable to use the above-mentioned Kevlar, a metal wire such as a steel wire, PBO, or the like from the viewpoint of tensile strength.

The tensile strength member 22 accommodated in the tensile strength member accommodating groove 20a is integrally embedded in the spacer 20 simultaneously with the extrusion molding of the spacer 20, but only the tensile strength member accommodating groove 20a is formed during the extrusion molding. After that, the strength member 22 may be attached thereafter. When the tensile strength member 22 is integrally embedded during extrusion molding, the advantage that the tension applied to the resin during extrusion can be accurately controlled during extrusion molding of the spacer 20, and the spacer 20 and the tensile strength member 22 However, there is an advantage that they can be surely integrated and the tensile strength can be improved.

The strength member 22 accommodated in the strength member housing groove 20a is intermittently interrupted at a part of the side wall 2 of the spacer 20.
It is exposed on the outer surface of 0b. In this way, the strength member 2
If at least a part of 2 is exposed to the outside, it is possible to easily remove the strength member 22.
The strength member 22 may be exposed continuously instead of intermittently. If the tensile strength member 22 is intermittently exposed, that is, if the tensile strength member 22 is intermittently completely buried, the spacer 20 and the tensile strength member 22 can be reliably secured at this buried portion. There are advantages that they can be integrated to improve the tensile strength and that the tensile strength body 22 can be prevented from being accidentally detached.

The optical fiber core wire 21 accommodated in the recess 20d of the spacer 20 is a tape-shaped optical fiber core wire 21 in which a plurality of optical fibers are arranged in parallel.
With a plurality of stacked layers, the recess 20 in the center of the spacer 20
It is stored in d. Note that FIG. 1 shows a state where all the optical fiber core wires 21 are stacked in the diameter direction of the optical cable C, but the optical fiber core wires 21 housed in the respective spacers 20 are arranged in the recesses 20d. It is housed in a twisted state.

A coarse winding thread (not shown) is spirally wound around the spacer unit 2 constituted by the spacer 20 and the optical fiber core wire 21 described above, and the periphery thereof is covered with the press winding 3. There is. The periphery of the press winding 3 is further covered with a polyethylene sheath 4. In the polyethylene sheath 4, a tear string 4a for tearing the polyethylene sheath 4 at the time of intermediate post-branching work is embedded.

Next, a method of manufacturing the above-mentioned optical cable C will be described. This manufacturing method uses the spacer unit 2
(See FIG. 4) and the step of aligning the spacer units 2 around the core material 1 (see FIG. 5).

First, a process of housing the optical fiber core wire 21 inside the spacer 20 and manufacturing the spacer unit 2 will be described with reference to FIG.

The spacer supply bobbin 5 has a spacer 2 in which a strength member 22 is embedded in a strength member housing groove 20a.
0 is wound. Further, a tape-shaped optical fiber core wire 21 is wound around the optical fiber supply bobbin 6 a, and a plurality of optical fiber supply bobbins 6 a are arranged in the cage 6. The cage 6 is rotatable around the optical fiber core wires 21 that are extended and assembled.

The spacer 20 and the optical fiber core wire 21 are extended from the spacer supply bobbin 5 and the optical fiber supply bobbin 6a from the left side in FIG.
While the optical fiber core wire 21 is housed in 0, the optical fiber core wire 21 is housed in the spacer 20 by wrapping the optical fiber core wire 21 around the mid wheel 7 having a diameter of 2 m, which is a unit pulling means, once. .

In this step, the mid wheel 7
Tension is applied from the mid wheel 7 to the spacer 20 and the optical fiber core wire 21 on the left side in the figure. The tension is applied to the spacer 20 and the optical fiber core wire 21 in order to make the spacer 20 and the optical fiber core wire 21 straight rather than in a bent state, and to facilitate the integration of the two. Also, the tension during this time is
In order to improve the manufacturing efficiency of (1), the feeding speed of the spacer 20 and the optical fiber core wire 21 from the spacer supply bobbin 5 and the optical fiber supply bobbin 6a will be further increased.

In the section where the tension is applied, the spacer 20
Since the tension member 22 is embedded in the spacer 20, the spacer 20 effectively counters the applied tension, and the spacer 20
Also, even if the feeding speed of the optical fiber core wire 21 is increased, it is possible to sufficiently oppose it, and the manufacturing efficiency of the spacer unit 2 can be improved. Also, the spacer 20 has a tensile strength member 2
Since 2 is buried, the spacer 2 is
0 does not expand, and a difference in length from the optical fiber core wire 21 is prevented.

The optical fiber core wire 20 is unwound while the entire cage 6 is rotated, and is housed in the recess 20d of the spacer 20 in a spirally twisted state. It is possible to prevent a difference in length between the laminated optical fiber core wires 21 when the winding wire 2 is wound around the mid wheel 7 or the unit winding bobbin 8. The optical fiber core wires 21 may be housed inside the spacer 20 without being formed in a spiral shape but simply stacked, but in this case, even when the spacer unit 2 is linear, The supplied optical fiber core wire 21 on the bottom side is provided so as not to bend due to a difference in length between the optical fiber core wire 21 near the bottom and the optical fiber core wire 21 near the top in the recess 20d. And different tensions are applied in advance to the optical fiber core 21 on the upper side, and the lengths are controlled to be uniform when the tension is linear. At this time, it goes without saying that the tension applied to the optical fiber core wire 21 is in a range that does not adversely affect the optical fiber core wire 21. Further, the diameter of the midwheel 7 also affects the difference in the lengths of the optical fiber core wires 21, so the diameter of the midwheel 7 is determined in consideration of this influence.

Spacer 2 accommodating the optical fiber core wire 21
A pair of tensile strength body winders 9 for removing the tensile strength body 22 from the spacer 20 are disposed on the downstream side of the mid wheel 7 around which 0 is wound. Between the wheel 7 and the unit winding bobbin 8, the strength member 22 embedded in both side walls 20b of the spacer 20 is wound. Between the mid wheel 7 and the unit winding bobbin 8, the spacer 20 is simply sent to the right in the drawing, and the tension is not positively applied, that is, the tension is released. Is. Therefore, even if the tensile strength member 22 is removed from the spacer 20, the spacer 20 does not expand and there is no problem.

Further, in this way to adopt a tension member winding machine 9 during the process of manufacturing the spacer unit 2, it is possible to smoothly remove the tension member 22, by this, to remove the tension member 22 The manufacturing cost can be reduced because it is not necessary to newly provide the step. Further, the strength member 22 to be removed is wound at the same time as it is removed, so that it can be reused, and the manufacturing cost can be reduced also from this point.

On the spacer 20 in which the optical fiber core wire 21 is housed and the strength member 22 is removed, the coarse winding device 10 winds the coarse winding yarn 10a around the spacer 20 to form the spacer unit 2, and the unit winding bobbin. After being wound up on No. 8, it is sent to the next step. Although the mid wheel 7 is used as the unit pulling means, the spacer 20 and the optical fiber core wire 21 may be sandwiched by a belt capstan using a sponge belt so that the spacer 20 and the optical fiber core wire 21 are fed while tension is applied to both.

Next, the step of aligning the above-mentioned spacer units 2 around the core material 1 will be described with reference to FIG.

The core material 1 is wound around the core material supply bobbin 11, and a plurality of spacer units 2 manufactured by the above-described process are wound around the core material 1 fed from the core material supply bobbin 11. A unit supply bobbin 8 is arranged. The spacer units 2 fed from the unit supply bobbin 8 are set on the reversing eye plate 12 and then aligned around the core material 1 in the SZ twisted state.

The reversing eye plate 12 for twisting the spacer unit 2 is a disc or ring formed of four sets, and the core material 1 is inserted through the center of the reversing eye plate 12, and the spacer unit is arranged near the circumference. 2 are inserted, and the core material 1 inserted in each is rotatable. The spacer unit 2 can be twisted in the SZ twist around the core material 1 by controlling the rotation directions of the reversing eye plates 12 in the forward and reverse directions.

The spacer unit 2 is twisted into the SZ twist by the reversing eye plate 12, and at the same time, the coarse winding device 13 winds the coarse winding yarn 13a around the coarse winding yarn 13a so that the SZ twist is not broken. The press winding device 14 winds the press winding tape 14a around. A belt capstan 15 is arranged on the downstream side of the press-winding device 14, and the belt capstan 15 allows the core material 1 to be fed at a constant speed from the core material supply bobbin 11 to the cable winding bobbin 16. There is. A core material 1 with spacer units 2 aligned around it
After the press-winding tape 14a is wound, it is wound on the cable winding bobbin 16 and the polyethylene sheath 4 is coated on the periphery by a mechanism (not shown) in another step to complete the optical cable C.

In this step, when the spacer units 2 are aligned around the core material 1, the tensile strength member 22 has already been removed from the spacer 20, so that the rigidity of the spacer 20 does not become too large. The spacer unit 2 is flexibly deformed when twisted into SZ twist (or S twist / Z twist). As a result, the optical fiber core wire 2 can be easily twisted into SZ and the like, and the side wall portion 20b does not press the optical fiber core wire 21.
The transmission characteristic of No. 1 is not adversely affected. Further, it is possible to provide good handleability without the workability being hindered by the rigidity of the spacer 20 being too great at the time of branching work after the intermediate step.

[0036] illustrates a cross-sectional view of another embodiment of a spacer used for the optical cable in FIG. The spacer 20 is shown in a state in which the tensile strength member 22 is embedded.
Are provided in a strip shape on the outer surfaces of the side wall portions 20b.
The strength member 22 is made of a thin fiber material such as Kevlar (registered trademark of DuPont) fiber, and the cross-sectional area of each strength member 22 is smaller than that of the strength member 22 shown in FIG. 3 described above. 22 are distributed and arranged in a plurality. For this reason, there is an advantage that the spacer 20 itself does not cause local cross-section loss and the strength of the spacer 20 is not locally weakened.
As described above, the number and position of the tensile strength members 22 embedded in the spacer 20 are not limited to those shown in FIGS. 3 and 4 described above.

[0037]

In the method of manufacturing an optical cable in which the spacer unit is formed by accommodating the optical fiber core wire inside the elongated spacer and the spacer unit is aligned around the core material, the spacer unit is arranged around the core material. According to the method for manufacturing an optical cable of the present invention, which is characterized in that the tensile strength members arranged along the longitudinal direction of the spacer are removed from the spacer before the alignment is arranged, the handleability is good and the transmission is good. An optical cable having characteristics can be manufactured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an optical cable of the present invention.

FIG. 2 is a partially cutaway side view showing an embodiment of the optical cable of the present invention.

FIG. 3 is a sectional view of a spacer used in the optical cable of the present invention.

FIG. 4 is a side view showing an embodiment (first half portion) of the optical cable manufacturing method according to the present invention.

FIG. 5 is a side view showing an embodiment (second half) of the method for manufacturing an optical cable according to the present invention.

FIG. 6 is a cross-sectional view showing another embodiment of the spacer used in the optical cable of the present invention.

[Explanation of symbols]

C ... Optical cable, 1 ... Core material, 2 ... Spacer unit, 3
... Pressing winding, 4 ... Polyethylene sheath, 5 ... Spacer supply bobbin, 6 ... Cage, 6a ... Optical fiber supply bobbin, 7 ... Unit pulling means (mid wheel),
8 ... Unit winding bobbin, 9 ... Tensile strength member winding mechanism, 11 ... Core material supply bobbin, 12 ... Inversion eye plate, 15
... Belt capstan, 16 ... Cable winding bobbin, 20 ... Spacer, 20a ... Grooves for receiving strength member, 21
... optical fiber core wire, 22 ... tensile strength member.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Hideyuki Iwata Inventor Hideyuki Iwata 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corporation (56) Reference JP-A-4-345110 (JP, A) Actual Kaihei 4-135715 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B 6/44

Claims (4)

(57) [Claims] 1. A method of manufacturing an optical cable in which an optical fiber core wire is housed inside a long spacer to form a spacer unit, and the spacer unit is aligned around the core material. A method for manufacturing an optical cable, characterized in that a tensile strength member arranged along the longitudinal direction of the spacer is removed from the spacer before the spacers are aligned around the periphery. 2. The optical fiber core wire and the spacer are supplied, the optical fiber core wire is housed inside the spacer, and the tensile strength member is removed before the spacer unit is wound on a unit winding bobbin. The method for manufacturing an optical cable according to claim 1, wherein the optical cable is removed from the spacer. 3. The optical fiber core wire is housed inside the spacer while tension is applied to the spacer by unit tension means, and the tensile strength member is removed from the spacer after passing through the unit tension means. Claim 1
Or the method for manufacturing an optical cable according to item 2. 4. The method for manufacturing an optical cable according to claim 1, wherein the strength member is removed from the spacer while the strength member is being wound.