JP3784521B2 - Multi-fiber cable - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-core optical fiber cable, and more particularly to a multi-core optical fiber cable excellent in post-branch workability.
[0002]
[Prior art]
In recent years, it has been studied to spread an optical fiber communication network to subscribers such as general households. As a subscriber system multi-core optical fiber cable used for such a purpose, for example, there is a slot type optical fiber cable as shown in FIG.
The multi-core optical fiber cable 21 shown here has an optical fiber core layer 23 and a sheath 24 sequentially provided on a slot type unit 22.
[0003]
The slot type unit 22 includes a slot 25, an optical fiber core wire 27 accommodated in a slot groove 26 formed in an SZ twist shape on the outer periphery of the slot 25, and a first presser winding layer provided on the slot 25. 28.
The first presser winding layer 28 is formed by winding a presser winding tape such as a polyester tape around the slot 25 in a spiral shape.
[0004]
The optical fiber core layer 23 includes a plurality of hook-like structures 29 twisted around the slots 25, the optical fiber core wires 30 accommodated in the hook-like structures 29, and the upper parts of the hook-like structures 29. The second presser wound layer 31 provided on the outer periphery.
The eaves-like structure 29 is arranged so that the opening thereof faces the outer peripheral side of the cable, and is twisted around the slot type unit 22 in an SZ twist shape.
The second presser winding layer 31 is formed by spirally winding a presser tape such as a polyester tape around the collar-shaped structure 29.
[0005]
When the optical fiber core wire 30 of the optical fiber core layer 23 of such a multi-core optical fiber cable 21 is branched backward, the sheath 24 of the portion to be branched back is removed, and then the optical fiber core wire layer 23 is removed. A part of the presser winding tape constituting the second presser winding layer 31 is cut, and the presser winding tape is unwound from the cut part, and the hook-like structure 29 in the vicinity of the inversion part (the part where the S twist is turned back to the Z twist). Is exposed, and the required number of the optical fiber cores 30 housed therein is taken out from the bowl-shaped structure 29.
[0006]
When branching the optical fiber core wire 27 of the slot-type unit 22, first, after exposing the hook-shaped structure 29, the hook-shaped structure 29 in the vicinity of the reversal portion is moved in a direction in which it is linear. The unit 22 is moved to be in a sagging state and is separated from the unit 22 to expose the unit 22.
Next, a part of the presser wound tape of the first presser winding layer 28 spirally wound on the slot 25 of the unit 22 of the exposed part is cut, and the presser wound tape is cut from the cut part along the spiral direction of the tape. The slot groove 26 in the vicinity of the reversing part is exposed while being unwound, and the required number of optical fiber core wires 27 accommodated therein is taken out from the slot groove 26.
[0007]
[Problems to be solved by the invention]
However, the above prior art has the following problems.
In the multi-core optical fiber cable 21, in order to branch the optical fiber core wire 27 in the slot groove 26 of the slot type unit 22, the presser winding tape of the first presser winding layer 28 is being pulled along the spiral direction of the tape. When unwinding, the slack-like structure 29 is in the way, and the work of unwinding the presser tape is difficult to perform, and there is a disadvantage that a great deal of labor is required for the post-branching work.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a multi-core optical fiber cable excellent in post-branch workability.
[0008]
[Means for Solving the Problems]
A multi-core optical fiber cable according to claim 1 of the present invention is provided with an optical fiber core layer provided on a slot type unit, the slot type unit having a slot having a slot groove formed in an SZ strand, and a slot groove. And a first presser wound layer provided on the slot, and the optical fiber core layer is twisted around the slot type unit in an SZ twisted manner. A slot type comprising a plurality of optical fiber core housings, an optical fiber core housed therein, and a second presser winding layer provided on the plurality of optical fiber core housings the slot grooves of the unit, upon comparing the optical fiber housing body of the optical fiber layer, inverting portion of the optical fiber container is arranged directly above the inversion of the slot grooves, first The presser foot layer is Consists longitudinal subscript been presser winding tape lot, the second pressing winding layer, characterized by comprising the plurality of presser winding tape wound onto the spirally optical fiber receptacle.
The multi-core optical fiber cable according to claim 2 of the present invention is characterized in that a twist direction of the plurality of optical fiber core wires is the same as a twist direction of the slot groove.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 9 show an embodiment of a multi-core optical fiber cable according to the present invention. The multi-core optical fiber cable 1 shown here has an optical fiber core layer 3 and a sheath on a slot type unit 2. 4 is sequentially provided.
[0010]
The slot type unit 2 includes a slot 5, an optical fiber core wire 7 accommodated in a plurality of slot grooves 6 formed on the outer periphery of the slot 5, and a first presser winding layer 8 provided on the slot 5. It will be.
The slot 5 is a long body made of a plastic material such as polyethylene or polypropylene, and a tension member 5a made of a twisted metal wire, a single metal wire, a fiber reinforced plastic (FRP) rod or the like is inserted through the center of the slot 5.
[0011]
The slot groove 6 formed in the slot 5 is formed to be SZ twisted, that is, to repeat S twist and Z twist alternately.
Hereinafter, the portion of the slot groove 6 that is twisted back from the S twist to the Z twist (or from the Z twist to the S twist) is referred to as a reversing portion T ₁ . Further, the distance from the inversion portion T ₁ to the inversion portion T ₁ adjacent thereto is referred to as an inversion pitch p ₁ .
The optical fiber core 7 is, for example, a laminate of 2 to 10 optical fiber tape cores of 2 to 10 cores.
[0012]
The first presser winding layer 8 is for protecting the optical fiber core wire 7 in the slot groove 6. In the multi-core optical fiber cable 1 of the present embodiment, the first presser winding layer 8 is provided with the presser winding layer 8. A tape 8a is vertically attached to the slot 5 along its longitudinal direction.
[0013]
As the presser tape 8a, a plastic tape made of polyester, polyimide or the like, a nonwoven fabric tape, or the like can be used. The width of the presser winding tape 8 a is appropriately set according to the outer diameter of the slot 5, but is usually preferably 20 to 100 mm. The thickness of the tape 8a is preferably 0.1 to 0.5 mm.
Further, it is preferable that the first presser winding layer 8 is formed by winding a coarsely wound string 8 b around the outer periphery of the presser winding tape 8 a and fixing the presser winding tape 8 a on the slot 5. As the coarsely wound string 8b, a fiber of about 100 to 1000d (denier) made of polyester, nylon, polyethylene or the like or a narrow tape of about 2 to 5 mm in width can be used.
[0014]
The optical fiber core layer 3 includes a plurality of hook-like structures 9 that are optical fiber core wires twisted around the slots 5, and optical fiber core wires 10 housed in the hook-like structures 9. The second presser wound layer 11 provided on the bowl-shaped structure 9.
[0015]
The bowl-shaped structure 9 is a bowl-shaped long body made of a plastic material such as polyethylene. The bowl-shaped structure 9 has a thickness of 0.5 to 2 mm, an inner width of 1 to 8 mm, and a depth. It is preferable to use one having a thickness of 1 to 8 mm. The saddle-like structure 9 is arranged so that the opening thereof faces the cable outer peripheral side.
[0016]
Trough-like structure 9 is twisted shape SZ stranded around the slot type unit 2, inversion pitch p _2, i.e. from the reversing portion T ₂ of the trough-like structure 9 to the reversing section T ₂ adjacent thereto The distance is set to be an integral multiple of the inversion pitch p ₁ of the slot groove 6 of the slot type unit 2, preferably equal to the inversion pitch p ₁ .
[0017]
The bowl-shaped structure 9 is twisted on the slot type unit 2 so that the inversion part T ₂ is located immediately above the inversion part T ₁ of the slot groove 6 of the slot type unit 2.
As the optical fiber core wire 10, the same one as the optical fiber core wire 7 accommodated in the slot groove 6 of the slot type unit 2 can be used.
[0018]
The second presser winding layer 11 is for positioning and fixing the bowl-shaped structure 9 on the slot type unit 2 and protecting the optical fiber core wire 10 in the bowl-shaped structure 9.
In the multi-core optical fiber cable 1 of the present embodiment, the second presser winding layer 11 is formed by winding the presser winding tape 11a on the hook-like structure 9 in a spiral shape. As the presser winding tape 11a, a material made of the same material as that of the presser winding tape 8a can be used, and the width is preferably 20 to 100 mm and the thickness is preferably 0.1 to 0.5 mm.
[0019]
When manufacturing the multi-core optical fiber cable 1 having the above structure, the optical fiber core wire 7 is accommodated in the slot groove 6 of the slot 5 while pulling the slot 5, and the press-wound tape 8 a is vertically attached to the outer periphery of the slot 5. The first presser winding layer 8 is formed to form the slot-type unit 2, and then the ridge-like structure 9 in which the optical fiber core wire 10 is accommodated in advance is twisted around the slot-type unit 2 so as to be SZ-twisted, The presser winding tape 11a is spirally wound on top to form the second presser winding layer 11, and finally the second presser winding layer 11 is covered with polyethylene or the like to form the sheath 4.
[0020]
Next, an operation when the optical fiber core wire 7 and the optical fiber core wire 10 of the multi-core optical fiber cable 1 having the above structure are branched off will be described with reference to FIGS.
First, the case where the optical fiber core wire 10 of the optical fiber core wire layer 3 is branched backward will be described.
[0021]
First, remove the sheath 4 of the portion located on the reverse portion T ₂ of the trough-like structures 9, to expose the optical fiber layer 3.
Then, a portion of the presser winding tape 11a constituting the second pressing winding layer 11 of the optical fiber layer 3 was cut, unwound a presser winding tape 11a from the cut portion, the inverted portion T ₂ near trough-like structure The body 9 is exposed.
Next, the optical fiber core wire 10 in the bowl-shaped structure 9 of the inversion part T ₂ is taken out from the bowl-shaped structure 9. At this time, since the twisted structure 9 is reversed in the twisting direction at the reversing portion T ₂ , when the optical fiber core wire 10 is taken out from the saddle-shaped structure 9, the optical fiber core wire 10 is slackened, The operation of separating this from the bowl-shaped structure 9 is facilitated, and the post-branching operation is facilitated.
[0022]
Next, the case where the optical fiber core wire 7 of the slot type unit 2 is branched backward will be described.
First, the cage structure 9 is exposed according to the above-described process.
Subsequently, the saddle-like structure 9 in the vicinity of the reversing portion T ₂ is moved on the slot type unit 2 in a direction in which the reversing part T ₂ becomes a straight line to be in a slack state and is separated from the slot type unit 2, 2 is exposed.
[0023]
Next, after removing the coarsely wound string 8b of the exposed first presser winding layer 8, a part of the presser tape 8a vertically attached to the slot 5 is cut.
Next, the press-wound tape 8 a at the cut portion is pulled in the direction of peeling from the slot 5 along the longitudinal direction of the slot 5 to expose the slot 5.
[0024]
As described above, the bowl-shaped structure 9 is twisted around the slot type unit 2 so that the inversion part T ₂ is located immediately above the inversion part T ₁ of the slot groove 6 of the slot type unit 2. and for that, by the operation, the slot groove 6 around reversing portion T ₁ is exposed.
The optical fiber core wire 7 is released from the slot groove 6 of the reversing part T ₁ exposed in this manner, and a post-branching operation is performed.
[0025]
In the multi-core optical fiber cable 1 having the above-described configuration, the first presser winding layer 8 of the slot type unit 2 is made of the presser winding tape 8 a vertically attached to the slot 5. When the inner optical fiber core 7 is branched backward, the hook-like structure 9 of the optical fiber core layer 3 in the portion to be branched back is slackened to expose the first presser winding layer 8 of the slot type unit 2. Then, the slot 5 can be exposed by a simple operation of pulling the press-wound tape 8a of the exposed portion along the longitudinal direction of the slot 5 in the direction of peeling from the slot 5.
For this reason, compared with an optical fiber cable in which the first presser winding layer is made of a spiral presser winding tape, the hook-like structure 9 in a state of being slackened in the operation of branching the optical fiber core wire 7 backward. Will not interfere with operation.
For this reason, not only the optical fiber core wire 10 on the cable outer peripheral side but also the optical fiber core wire 7 on the cable center side can be taken out with an easy operation. Therefore, it is possible to improve the post branching workability.
[0026]
Further, in the case of the multi-fiber optical fiber cable 1, the first presser winding layer 8 can be formed on the slot 5 by a simple operation in which the presser winding tape 8 a is vertically attached to the slot 5 at the time of manufacture. .
Therefore, the first presser wound layer can be manufactured more efficiently than an optical fiber cable in which the first presser wound layer is formed of a presser wound tape wound spirally on the slot.
[0027]
Further, the second presser wound layer 11 is made of a presser wound tape 11a spirally wound on the bowl-shaped structure 9, so that the second presser wound layer 11 has a tensile strength against a force in the cable circumferential direction. It can be made excellent.
For this reason, when the sheath 4 is contracted and deformed, a force in the center direction of the cable is applied to the second presser winding layer 11 in the portion located on the opening of the bowl-shaped structure 9 by the inner wall, and the second presser winding layer 11 is applied. Even when a tensile stress in the cable circumferential direction is applied, the second presser winding layer 11 is not broken or stretched and does not enter the cage-like structure 9, and the optical fiber core wire 10 is reliably protected. Can do.
[0028]
Furthermore, the saddle-like structure 9 is twisted on the slot type unit 2 so that the inversion part T ₂ is located immediately above the inversion part T ₁ of the slot groove 6 of the slot type unit 2. slack gutter-like structure 9 in the vicinity of the inverted portion T ₂ to expose the unit 2, by removing the first retainer winding layer 8, it is possible to reliably expose the reversing portion T ₁ of the slot groove 6 of the unit 2 it can.
For this reason, not only the optical fiber core wire 10 on the cable outer peripheral side but also the optical fiber core wire 7 on the cable center side can be taken out with an easy operation.
Therefore, the post-branch workability can be further improved.
[0029]
In the multi-core optical fiber cable 1 having the above structure, only one optical fiber core layer 3 is provided on the slot type unit 2, but the multi-core optical fiber cable of the present invention is not limited to this. A plurality of optical fiber core layers may be provided on the slot type unit 2.
In this case, the presser wound layer of the optical fiber core layer other than the optical fiber core layer on the outermost peripheral side is formed of a presser wound tape attached vertically, and further includes a slot groove of the slot type unit, and a plurality of slots When the two adjacent upper and lower (cable diametrical direction) structures of the optical fiber core layer are compared, the inversion part of the upper side (cable outer peripheral side) is the lower side (cable center side). It should be placed directly above the reversal part of the object.
In this way, by providing a plurality of optical fiber core layers on the slot type unit 2, further multi-core can be achieved without deteriorating the post-branching workability.
[0030]
【The invention's effect】
As described above, in the multi-core optical fiber cable of the present invention, the post-branching workability can be improved.
[Brief description of the drawings]
1A and 1B show an embodiment of a multi-core optical fiber cable of the present invention, in which FIG. 1A is a cross-sectional view of the optical fiber cable, and FIG. 1B is a perspective view showing a bowl-shaped structure.
FIG. 2 is a plan view showing the internal structure of the multi-core optical fiber cable shown in FIG.
3 is a plan view showing an internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
4 is a plan view showing the internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
5 is a plan view showing an internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
6 is a plan view showing the internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
7 is a plan view showing the internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
8 is a plan view showing an internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
9 is a plan view showing the internal structure of the multi-core optical fiber cable shown in FIG. 1. FIG.
FIG. 10 is a cross-sectional view showing a conventional multi-core optical fiber cable.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Multi-core optical fiber cable, 2 ... Slot type unit, 3 ... Optical fiber core layer, 4 ... Sheath, 5 ... Slot, 6 ... Slot groove,
7, 10 ... optical fiber core wire, 8 ... first presser wound layer, 8a, 11a ... presser wound tape, 9 ... saddle-like structure (optical fiber core container), 11. ..Second presser foot layer,
T ₁ , T ₂ ... reversing part

Claims (2)

An optical fiber core layer is provided on the slot type unit,
The slot-type unit includes a slot having a slot groove formed in an SZ twist shape, an optical fiber core housed in the slot groove, and a first presser winding layer provided on the slot. ,
A plurality of optical fiber cores in which an optical fiber core layer is twisted around the slot type unit in an SZ twist form, an optical fiber core accommodated therein, and the plurality of optical fiber cores accommodated therein A second presser wound layer provided on the body,
The slot grooves of the slot type unit, upon comparing the optical fiber housing body of the optical fiber layer, inverting portion of the optical fiber container is arranged directly above the inversion of the slot grooves,
The first presser foot layer is composed of presser foot tape vertically attached to the slot,
The multi-core optical fiber cable, wherein the second presser winding layer is made of a presser wound tape wound spirally on the plurality of optical fiber core wires. 2. The multi-fiber cable according to claim 1, wherein a twist direction of the plurality of optical fiber core containers is the same as a twist direction of the slot groove.

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