JPH0943467A - Optical cable for aerial laying and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical cable for aerial laying which prevents the elongation of the coated optical fibers in an optical cable core, prevents infiltration of water and is good in productivity. SOLUTION: An optical cable core part 2 is sagged zigzag with respect to a supporting wire part 1 and the distance from this supporting wire part 1 to the optical cable core part 2 is long in the A-A' part having a separating part 4 and short in a B-B' part coupled by a neck part 3a. An aluminum tape is welded right on the outer periphery of the optical cable core longitudinally along this core to cover the optical cable core. This aluminum tape is a corrugated aluminum tape coated with a resin. The sectional secondary moment of the aluminum tape is diminished by the corrugation, by which the flexibility of the optical cable core coated with the aluminum tape is improved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical cable for aerial installation.
It is about Bull.

[0002]

2. Description of the Related Art In an aerial installation optical cable, a decrease in strength of an optical fiber due to elongation in a suspended state poses a serious problem in terms of reliability. Therefore, the optical cable core and the supporting wire are connected by a connecting member at predetermined intervals, and the shape and dimension are set so that the optical cable core is longer than the supporting wire, for example, Japanese Utility Model Laid-Open No. 59-95304. And so on. The advantage of such a structure in which the optical cable core is long with respect to the support line is that when the support line is tensioned in a suspended state and the support line extends, the extension of the optical cable core and the optical fiber accommodated therein Can be alleviated.

However, in order to obtain a structure in which a connecting member is used as in the prior art described above, the supporting wire and the optical cable core are subjected to a separate process, and then they are connected by the connecting member. Since the process is required and the number of processes increases, there is a problem in productivity.

Therefore, in the process of commonly covering the optical cable core and the supporting wire with the sheath, the optical cable core is forcedly pushed into the common sheath covering portion, so that the optical cable core is pushed longer than the supporting wire, and the supporting wire is supported. On the other hand, a manufacturing method of giving the optical cable core a meandering slack is conceivable.

On the other hand, in an optical cable for overhead installation,
In some cases, an aluminum tape resin-coated with a heat-adhesive resin is vertically attached and welded directly on the outer periphery of the optical cable core. Since the strength of the optical fiber is lowered by water, the optical cable for aerial installation is prevented from flooding in this way.

However, since this aluminum tape has a large second moment of area, the flexibility of the optical cable core is reduced. As a result, when trying to manufacture such an aerial laying optical cable by the above-mentioned manufacturing method, the above-mentioned pushing force becomes considerably large, so that the resin coating of the aluminum tape peels off at the roller portion of the pushing device. was there.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and prevents the extension of the optical fiber core wire in the optical cable core and prevents the infiltration of water. It is an object to provide an optical cable and a manufacturing method thereof.

[0008]

According to a first aspect of the present invention, in an optical cable for overhead installation, an optical cable core and a supporting wire, in which a resin-coated corrugated aluminum tape is longitudinally welded to the outer periphery, have a neck portion. It is characterized in that the optical cable core is commonly covered with a partially provided sheath, and the optical cable core has a meandering slack.

According to a second aspect of the present invention, in the method of manufacturing an optical cable for overhead installation, a resin-coated aluminum tape is corrugated and vertically welded to the outer periphery of the optical cable core, and then the optical cable core is supported. The wire is pushed into the common sheath covering portion such that the pushing force of the optical cable core is made larger than the pushing force of the supporting wire and the optical cable core is longer than the supporting wire, and the wire is a sheath partially having a neck portion. It is characterized in that the optical fiber is coated with a common coating to give the optical cable core a meandering slack.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view of an optical cable for overhead installation which is an embodiment of the present invention. 2A and 2B are cross-sectional views of an optical cable for aerial laying, which is an embodiment of the present invention. FIG. 2A is a cross section taken along the line AA ′ in FIG. 1 and FIG. 2B is a line BB ′ in FIG. It is a cross section. In the figure, 1 is a supporting wire portion, 2 is an optical cable core portion, 3 is a common sheath, 3a is a neck portion, 4 is a separating portion, 5 is a supporting wire, 6 is an optical cable core, 6a is a central tensile member, 6b is a slot, 7 Is an optical fiber, and 8 is an aluminum tape. In FIG. 1, this aerial laying optical cable is a self-supporting optical cable in which a supporting wire portion 1 and an optical cable core portion 2 are commonly covered and integrated with a common sheath 3 partially having a neck portion 3a.

The neck portions 3a are periodically provided, for example, in the longitudinal direction of the cable, and the adjacent neck portions 3a are separated portions 4. The optical cable core portion 2 has a meandering slack with respect to the support wire portion 1, and the support cable portion 1 to the optical cable core portion 2 are provided.
The distance to is long in the AA 'part where the separation part 4 is present and short in the BB' part connected by the neck part 3a, and the cross section at each part is shown in FIGS. 2 (A) and 2 (B). It is shown. The optical cable core portion 2 may meander freely, but in the illustrated example, the optical cable core portion 2 meanders in the vertical direction which is vertical in the suspended state.

The sectional structure will be described with reference to FIG. The support wire 5 and the cable core 6 are arranged at a distance, and are covered by the common sheath 3 continuous in the longitudinal direction,
The support wire portion 1 and the optical cable core portion 2 are respectively constituted, and both are integrated by the neck portion 3 a of the common sheath 3.
The support wire 5 is composed of, for example, a plurality of tensile strength members such as steel wires. The optical cable core 6 is, for example, a slotted optical cable core having a central tensile strength body 6a therein and a plurality of slots 6b on its outer peripheral surface, and one or a plurality of optical fiber core wires 7 are provided in the slot 6b. It is stored. As the optical fiber core wire 7, a single core wire,
Any material such as a tape-shaped or tube-shaped core may be used.

The aluminum tape 8 is a corrugated aluminum tape whose one or both sides are previously coated with a resin having a heat adhesive property and which is corrugated in the longitudinal direction of the cable. Immediately above the outer circumference of the optical cable core 6, such an aluminum tape 8 is vertically attached in the longitudinal direction of the optical cable core 6, bent in the circumferential direction, and the left and right side end portions are welded by a heat-adhesive resin coating. It covers the core 6.

In a state in which this aerial laying optical cable is suspended by applying tension to the supporting wire 5, the supporting wire 5 extends, but the optical cable core 6 has a meandering slack with respect to the supporting wire 5, so that there is the separating portion 4. The optical cable core 6 is the supporting wire 5 in the part.
, The length of the central axis of the optical cable core 6 does not change. That is, the optical fiber core 6 and the optical fiber core wire 7 housed in the slot 6b of the optical cable core 6 are prevented from being stretched and distorted.

At this time, since the aluminum tape 8 is corrugated, the cross-section secondary mode of the aluminum tape 8 is changed.
The optical cable has a smaller size and is covered with aluminum tape 8.
The flexibility of the bull core 6 is improved. Therefore, when suspending this aerial laying optical cable, the optical cable core 6 covered with the aluminum tape 8 can be smoothly deformed from the meandering state.

This effect can be obtained even with an aluminum tape which is not coated with a resin. When such an aluminum tape is used, the joints of the left and right side end portions of the aluminum tape may be closed by welding, bonding or the like by a method other than the heat-adhesive resin coating.

FIG. 3 is a block diagram of a manufacturing apparatus for explaining the method for manufacturing an optical cable for overhead installation which is an embodiment of the present invention. In the figure, the same parts as those in FIG. 11 is a support line supply, 12 is an optical cable core supply, 13 is an aluminum tape supply, 14 is a corrugator, 15 is an aluminum tape molding former, 16 is an aluminum tape molding die, 17 is a hot air blower, and 18 is a pressure roller for bonding aluminum tape. , 19 is a cable core pushing device, 20 is a motor, 21 is a sheath covering portion, 22 is an extruder, and 23 is an optical cable for overhead installation.

First, the overall structure of the manufacturing apparatus will be described. The support wire 5 is supplied from the support wire supply 11 to the sheath coating portion 21. The optical cable core 6 is supplied from the optical cable core supply 12 to the aluminum tape molding die 16.
The resin-coated aluminum tape 8 is supplied from the aluminum tape supply 13 to the aluminum tape molding die 16 through the corrugator 14 and the molding former 15.

The optical cable core 6 covered with the aluminum tape 8 in the aluminum tape molding die 16 passes through the hot air blowing device 17, the aluminum tape bonding pressing roller 18, and the cable core pushing device 19, and the sheath coating portion 21.
, Where it is co-coated with the support wire 5,
The optical cable 23 for aerial installation is cooled and wound up. A coating material is supplied from the extruder 22 to the sheath coating portion 21. The cable core pushing device 19 is connected to the motor 20.

Next, the operation of each part will be described. The corrugator 14 is, for example, a pair of cylindrical rotating bodies having rounded teeth along the circumferential direction on the outer peripheral surface, and is arranged so as to face the front and back of the resin-coated aluminum tape 8 and has the resin coating. The aluminum tape 8 is rotated while being pressed alternately from the front and back surfaces. The aluminum tape 8 with resin coating is
The corrugator 14 causes the tape to wavy in the longitudinal direction.

The corrugated resin-coated aluminum tape 8 is bent in advance in the aluminum tape forming former 15 with the longitudinal direction of the tape as the central axis. The bent aluminum tape 8 is vertically attached to the optical cable core 6 in the aluminum tape molding die 16 to wrap the optical cable core 6 and is further bent along the circumferential direction of the optical cable core 6 to have a shape close to a tube. .

The aluminum tape 8 encapsulating the optical cable core 6 is heated with a heat-adhesive resin coating in the hot air blower 17, and the left and right side ends of the aluminum tape bonding press roller 18 are partially overlapped. It is then welded with a heat-adhesive resin coating to form a tubular body covering the outer periphery of the optical cable core 6 directly above.

The optical cable core 6 covered with the aluminum tape 8 is supplied to the sheath covering portion 21 in the cable core pushing device 19 with a large pushing force given by a pair of rollers driven by the motor 20. On the other hand, the support wire 5 is supplied to the covering portion 21 without being given a large pushing force. The optical cable core 6 and the support wire 5 covered with the aluminum tape 8 are supplied with the coating material from the extruder 22 in the coating portion 21, and are commonly coated with a sheath partially having a neck portion.

At this time, since the optical cable core 6 covered with the aluminum tape 8 is applied with a pushing force larger than the pushing force with respect to the support wire, the sheath coating portion 21 is fed at a faster feeding speed than the support wire 5. It is pushed longer than the support line 5 and is given a serpentine slack.

In order to cover the neck part with a sheath having a partial neck part, for example, the neck part forming part of the die hole of the crosshead may be opened intermittently, or the neck part of the die hole of the crosshead may be formed. The resin material may be intermittently supplied to the portion for use.

In the optical cable for overhead installation according to the present invention, since the aluminum tape 8 is corrugated, the secondary moment of the cross section of the aluminum tape 8 becomes small and the optical cable
The flexibility of the bull core is improved. Therefore, in the case of manufacturing by the above-described manufacturing apparatus, in the cable core pushing device 19, the pushing force for giving the optical cable core a meandering slack is relatively small, and the resin coating of the aluminum tape 8 prevents the pushing device 19. It has an effect of not peeling at the roller portion or the like.

However, the production of the optical cable for overhead installation of the present invention is not limited to the above-mentioned production method.

[0028]

EXAMPLES Examples embodying the present invention will be described. As the optical cable core 6, a slot type optical cable core made of polyethylene having a 2.3 mmφ steel wire as a center and having a groove having an outer diameter of 19 mm was used. As the resin-coated aluminum tape 8, a 0.2 mm-thick aluminum tape on both sides of which a 0.05 mm-thick thermo-adhesive resin is applied, with a 0.5 mm height and a 2.0 mm pitch wavy It was processed and vertically attached and welded. Pushing in the optical cable core 6 is 5 kg
The constant load of f was applied and the speed was set to be 0.4% longer than the supporting wire 5. The neck portion 3a of the common sheath 3 has a length of about 5 cm in the cable longitudinal direction and is provided at intervals of about 1 m.

When an attempt was made to manufacture the resin-coated aluminum tape 8 without corrugation, the pushing force for giving the optical cable core a meandering slack was 20 kg.
When the temperature reaches f, the resin of the aluminum tape 8 with the resin coating peels off at the roller portion of the cable core pushing device 19, and the pushing is practically impossible. The aluminum tape which is not corrugated has a secondary cross-sectional moment about eight times larger than the above-mentioned corrugated aluminum tape 8.

[0030]

As is apparent from the above description, according to the invention described in claim 1, the optical cable core and the supporting wire are commonly covered by the sheath having the neck portion partially, and the optical cable core has the meandering slack. Therefore, even when tension is applied to the support wire in a suspended state and the support wire is extended, there is an effect that the extension of the optical cable core and the optical fiber housed therein can be eliminated.

Further, since the resin coated corrugated aluminum tape is longitudinally welded to the outer periphery of the optical cable core, not only can water be prevented from entering the optical cable core, but also
Since the secondary cross-section moment of the aluminum tape is reduced and the flexibility of the optical cable core is improved, the optical cable core can be smoothly deformed from the meandering state when suspending this optical cable for overhead installation. effective.

According to the second aspect of the present invention, the optical cable core and the supporting wire are common so that the pushing force of the optical cable core is larger than the pushing force of the supporting wire and the optical cable core is longer than the supporting wire. Since it is pushed into the sheath covering part and is commonly covered with a sheath having a neck part,
In order to give a meandering slack to an optical cable core, conventionally, three steps have been required, in which the supporting wire and the cable are individually processed in separate steps, and then joined by a connecting member. It is possible with and has the effect of being highly productive.

Furthermore, since the resin-coated aluminum tape is corrugated and vertically welded to the outer circumference of the optical cable core, the optical cable core is pushed into the common sheath coating portion, so that the optical cable core is given a serpentine slack. Since the pushing force is comparatively small and the resin coating of the aluminum tape does not peel off at the time of pushing, there is an effect that the productivity is good.

[Brief description of drawings]

FIG. 1 is a side view of an optical cable for overhead installation, which is an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an optical cable for overhead installation which is an embodiment of the present invention, FIG. 2 (A) being a cross section taken along the line AA ′ of FIG.
FIG. 2B is a BB ′ cross section of FIG. 1.

FIG. 3 is a configuration diagram of a manufacturing apparatus for explaining a method of manufacturing an optical cable for overhead installation, which is an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Support wire part, 2 ... Optical cable core part, 3 ... Common sheath, 3a ... Neck part, 4 ... Separation part, 5 ... Support wire, 6 ... Optical cable core, 7 ... Optical fiber core wire, 8 ... Aluminum tape, 1
4 ... Corrugator, 15 ... Aluminum tape molding former, 1
6 ... Aluminum tape molding die, 17 ... Hot air blower, 18
... Pressing roller for adhering aluminum tape, 19 ... Cable core pushing device, 20 ... Motor, 21 ... Sheath covering portion,
22 ... Extruder, 23 ... Optical cable for overhead installation.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroki Ishikawa 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works

Claims (2)

[Claims] 1. An optical cable core in which a resin-coated corrugated aluminum tape is longitudinally welded to the outer periphery and a supporting wire are commonly covered with a sheath partially having a neck, and the optical cable core has a meandering slack. A characteristic optical cable for overhead installation. 2. A resin-coated aluminum tape is corrugated and longitudinally welded to the outer circumference of the optical cable core, and then the optical cable core and the supporting wire are pushed by the pushing force of the optical cable core from the pushing force of the supporting wire. And the optical cable core is pushed into the common sheath covering portion so that the optical cable core is longer than the supporting line, and the optical cable core is commonly covered with a sheath partially having a neck portion to give the optical cable core a meandering slack. Manufacturing method of optical cable for overhead installation.