JPH1078538A - Self-supporting optical cable with extra length with slit and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical cable having excellent beauty and excellent cost effectiveness by supporting and connecting an optical cable part via plural neck parts to a hanging wire part, putting an extra length into the optical cable part and meandering the cable in a vertical direction and a longitudinal direction. SOLUTION: The optical cable 1 is arranged with the optical cable part 4 extrusion coated with a sheath around an optical fiber cable core and the hanging wire part 6 extrusion coated with a sheath around the hanging wire in approximately parallel. The optical cable part 4 and the hanging wire part 6 are connected by the plural neck parts 7, 7,... disposed at equal intervals along the longitudinal direction thereof. The optical cable part 4 is longer by about 0.several to several % than the hanging wire part 6 and is provided with an extra length of, for example, about 2.0% from the hanging wire part 6. The optical cable part 4 is so supported and connected as to meander in the vertical direction with respect to the hanging wire part 6 extending in an approximately linear form. Then, the optical cable appears to meander in the vertical direction like sinusoidal waves when the optical cable is viewed from laterally. The optical cable appears as if the straight lines are superposed on each other when the cable is viewed from below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-supporting optical cable integrally provided with a suspension line for reducing the tension applied to an optical fiber cable when the cable is laid or extended, and a method of manufacturing the same. .

[0002]

2. Description of the Related Art Conventionally, a self-supporting optical cable A as shown in FIG. 9 has been widely used as an overhead optical cable.

[0003] As shown in the figure, the self-supporting optical cable A has an optical cable portion 4 in which a sheath 3 made of a thermoplastic resin such as polyethylene is extrusion-coated around an optical fiber cable core 2, and a sheath 3 around the suspension line 5. Are arranged in parallel with the suspension line portions 6 extruded and coated, and the neck portion 7 covered and extruded at the same time as the sheath 3 is interposed therebetween.
The suspension line 6 is directly subjected to tension caused by wind pressure or the like when the cable is laid or when the cable is extended, so that the tension applied to the optical cable 4 is reduced to prevent disconnection or elongation thereof.

In general, in such a self-supporting type optical cable A, when tension is applied to a suspension line by natural phenomena such as a tension at the time of laying the cable, a tension at the time of tension, and a wind pressure, Since the stranded portion 6 extends about 0.2%, if the stranded portion 6 and the optical cable portion 4 have the same length,
There is a problem that the optical cable portion 4 is extended to the same extent as the suspension line portion 6 is extended, and the optical transmission loss increases.

Therefore, the conventional self-supporting optical cable A
Then, by forming a plurality of slits 8 extending along the length direction in the neck portion 7, the wind pressure and the like are released, the tension applied to the entire cable A is reduced, and furthermore, FIG.
As shown in FIG. 0, when the length of the optical cable portion 4 is increased by about 0.2% in advance with respect to the length of the suspension line portion 6 so as to have an extra length, and the suspension line portion 6 is extended. Even so, the extension is prevented from reaching the optical cable section 4 side.

[0006]

By the way, in the conventional extra-length self-supporting optical cable as shown in FIG. Since it was meandering in the direction, it looked like a snake entangled in the wire when viewed from below, and it was not very good looking. Further, since the neck portion 7 connecting the optical cable portion 4 and the hanging wire portion 6 is continuous in the length direction, a large amount of thermoplastic resin material is required, and the cost is high.

Accordingly, the present invention has been devised to effectively solve such a problem, and an object of the present invention is to provide a new self-supporting type having a slit with a long slit which is excellent in aesthetics and economical. An optical cable and a method for manufacturing the same are provided.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a suspension line extending substantially linearly through a plurality of necks provided at predetermined intervals along the length thereof. In addition to supporting and connecting the optical cable section, an extra length is inserted into the optical cable section, and the optical cable section is meandered in the vertical direction and the length direction below the suspension line section. Therefore, the optical cable portion does not meander in the left-right direction with respect to the suspension line portion after the overhead line as in the related art, and the aesthetic appearance can be improved while maintaining a sufficient extra length. In addition, with the above configuration, the air can pass through the cross wind well, and the wind pressure vibration can be reduced. In addition, by widening the slit pitch (interval) between the necks to several times or more, for example, about 100 mm to 1000 mm, the optical cable can easily meander in the vertical direction, and as a result, is supported and connected to the neck. When the optical cable part is seen from the side, it meanders beautifully in the vertical direction like a sine wave,
In addition, when viewed from below, the straight lines appear to overlap each other, so that the appearance is further improved. Further, this reduces the amount of use of a thermoplastic resin material such as a polyethylene resin that forms the neck, thereby achieving cost reduction. In addition, by making the length of the neck portion shorter than that of the conventional one and increasing the width thereof, the optical cable portion is less likely to bend left and right, and it is more beautiful to meander in the vertical direction.

As a method of manufacturing a self-supporting optical cable having an extra length with a slit having such a configuration,
The suspension wire and the optical fiber cable core are arranged and sent out in parallel, and a sheath made of a thermoplastic resin is collectively extrusion-coated on the outer periphery thereof to form a suspension wire portion and an optical cable portion, and these are made of a thermoplastic resin. A plurality of necks are intermittently connected to form a gourd-shaped cross section, and before these sheaths and necks are solidified, a half-shaped suspension line side groove through which the suspension line passes and a half-split shape through which the optical cable portion passes. Pass the capstan having an outer diameter difference with the cable side groove part to form an extra length in the optical cable part with respect to the above-mentioned suspension line part, and then put the optical cable part below the suspension part to maintain the extra length of the optical cable. In the above, after being formed so as to meander in the vertical direction and the length direction, the sheath and the neck were formed so as to be cooled and solidified. UNA excellent excess length containing self-supporting optical cable with a slit in the aesthetics efficiently and can be manufactured at low cost.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a self-supporting optical cable 1 having a slit and having an extra length according to the present invention (hereinafter, abbreviated as an optical cable 1).
2 is an enlarged view of a portion A in FIG. 1, and FIG. 3 is a sectional view taken along line AA in FIG.

As shown in the figure, the optical cable 1 comprises an optical cable portion 4 in which a sheath 3 is extrusion-coated around an optical fiber cable core 2 and a suspension line portion 6 in which a sheath 3 is extrusion-coated around a suspension line 5. Are arranged in parallel, and the optical cable section 4 and the suspension section 6 are connected by a plurality of necks 7, 7... Provided at equal intervals along the length direction thereof. Slit 8 between
Are formed, and the cross section of each of the neck portions 7 is formed substantially in a gourd shape as shown in FIG. 2 (B).

Further, as shown in FIG. The cable portion 4 is longer than the cable portion 4 by about several percent to several percent, for example, about 2.0% more than the cable section 4. On the other hand, the optical cable unit 4 is connected to the suspension line unit 6 in a meandering state. In addition, the meandering direction of the optical cable unit 4 is in the direction of the suspension line 6, that is, since the suspension line 6 is located above the optical cable unit 4 after the overhead line,
The optical cable portion 4 is supported and connected so as to meander in the vertical direction. Therefore, by using such a cable 1, when the cable is viewed from the side after the overhead line, the optical cable section 4 looks beautifully meandering like a sine wave in the vertical direction, and when viewed from below, the optical cable section 4 has a straight line. Appear to overlap each other, and the aesthetic appearance is greatly improved over that of the related art while maintaining a sufficient extra length. further,
As a result, the amount of the thermoplastic resin material such as polyethylene resin constituting the neck portion is reduced, and the cost is also reduced.

The pitch of the slits 8 formed between the necks 7, 7 is several times or more, for example, 100 m, as can be seen from comparison with FIGS.
Since the optical cable portion 4 is widened to about m to 1000 mm, the optical cable portion 4 is more likely to meander in the vertical direction, and the appearance is further improved. Further, by making the length of the neck portion 7 shorter than that of the conventional one and increasing its width, the optical cable portion is hardly bent left and right, and furthermore, it becomes easy to meander neatly in the vertical direction. As a specific shape and dimensions of the neck 7 for achieving this, as shown in FIGS. 2 and 3, the hanging wire diameter D ₁ and the optical cable diameter D _1
2 (D ₁ <D ₂ ), the optical cable portion 4 is formed in a substantially trapezoidal cross section, and the optical cable portion 4 has a width in the length direction of 5 mm to 100 mm.
mm, and the thickness in the radial direction is 2.0 m on the side of the suspension line 4.
m to 3 / 4D ₁ , 2.0 mm to 3/4 on the optical cable side
D ₂ is suitable.

Next, an embodiment of a method for manufacturing the self-supporting optical cable 1 with the extra length having a slit according to the present invention having such a configuration will be described.

FIG. 4 shows an apparatus for producing the self-supporting optical cable 1 with a slit according to the present invention. In FIG. 4, reference numeral 9 denotes a suspension wire 5 formed by twisting a plurality of galvanized steel wires. 10 is an optical fiber cable drum for feeding out the optical fiber cable core 2, 11 is the hanging wire 5 and the optical fiber cable core 2
An extruder that extrudes and coats a thermoplastic resin around the extruder to form the sheath 3; 12 is a slit portion that forms the neck 7 and the slit 8; 13 is an extra length forming portion that inserts extra length into the optical cable portion 4; Reference numeral 14 denotes a cooling water tank that corrects and cools the optical cable 1, 15 denotes a take-up machine that pulls the optical cable 1, and 16 denotes a winding drum that winds the formed optical cable 1. First, the suspension lines 5 sent out in parallel from the suspension line drum 9 and the optical fiber cable drum 10 respectively.
When the optical fiber cable core 2 is simultaneously passed through the extruder 11, a thermoplastic resin such as polyethylene is extruded around the core to form a sheath 3. After being formed independently so as to be separated from each other, a neck portion 7 and a slit 8 are provided, which intermittently connect the two by passing through a slit portion 12 provided on the downstream side thereof. It is formed.

Next, the optical cable 1 that has exited from the extruder 11 flows toward the extra length forming portion 13 on the downstream side, and is guided so as to be wound around a capstan 13a having a trapezoidal cross section provided therein. By doing so, an extra length is provided on the cable section 4 side. That is, as shown in FIG. 5, the capstan 13a has a drum-shaped capstan body 18 rotatably supported by a shaft 17 and guides the optical cable 4 along its outer peripheral surface. a cable groove portion 19 in which the semicircular cross section, suspension wire groove portion 20 in which the semicircular section to guide the suspension wire portion 6 is formed in parallel to each addition, as shown, the rotation of the suspension wire groove portion 20 radius R ₂ It is set to be shorter than the radius of rotation R ₁ of the cable side groove 19. For this reason, the outer peripheral length of the cable side groove portion 20 is larger than the outer peripheral length of the cable side groove portion 2 by 2R ₁ π-2R.
_Since it is set to be shorter by 2π, the suspension line portion 6 and the optical fiber cable portion 4 of the optical cable 1 flowing from the extruder 11 are connected to the suspension line side groove portion 19 and the cable side groove portion 1.
8 are guided so as to mesh with each other, so that the sheath 3 and the neck portion 7 in a state where the thermoplastic resin is soft are deformed, and the cable 1 having an extra length formed on the optical fiber cable portion 4 side with respect to the suspension line portion 6. Is obtained. Since this extra length ratio is proportional to the contact distance of the capstan 13a,
For example, as shown in FIG. 6, by using another capstan 13b in which the curvature of the suspension line side groove portion 20 and the cable side groove portion 19 is changed, the extra length on the optical cable portion 4 side can be arbitrarily adjusted.

Next, the cable 1 that has exited the excess length forming section 13 is sent to a cooling water tank 14 as shown in FIG. Since the meandering forming means 14a having the structure shown in FIG. 7 is provided in the cooling water tank 14 together with the cooling water, a pair of belt conveyors 2 forming the meandering forming part 14a are provided.
By passing the suspension line portion 6 and the optical cable portion 4 while pressing them in parallel with each other, the meandering direction of the optical cable portion 4 is corrected toward the suspension line portion 6 and the sheath 3 and the neck portion 7 are cooled and solidified. You.

Thereafter, the optical cable 1 that has exited the cooling water tank 14 is taken up by the take-up device 15 and then continuously taken up by the take-up device 16.

As described above, according to the method of the present invention, an extra length is added to the optical cable portion of the soft cable 1 immediately after the extrusion coating, and the cable is cooled and solidified while correcting the meandering direction toward the hanging wire portion. It is possible to efficiently and inexpensively manufacture a self-supporting optical cable having an extra length with a slit as described above, which is excellent in beauty. In addition, the belt conveyors 21 and 2 constituting the meandering forming means 14a
Reference numeral 1 includes a wheel 22, a belt 23, and a roll 24, all of which are immersed in cooling water and driven by the advance of the cable 1 or driven in conjunction with the take-off machine 15. FIG. 8 shows another belt conveyor 25, 25 constituting the meandering forming means 14a.
By including the sprocket wheel 26, the caterpillar chain belt 27, the chain guide 28, and the guide sprocket 29, the same operation as the belt conveyor 21 can be exhibited.

[0021]

In summary, according to the present invention, a self-supporting optical cable having a slit and having an extra length can be easily and economically manufactured by meandering the optical cable in the vertical direction. In addition, it is possible to exhibit excellent effects such as good passage of air with respect to the crosswind and reduction of wind pressure vibration.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the cable of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is an overall configuration diagram showing one embodiment of a manufacturing apparatus used in the method of the present invention.

FIG. 5 is a configuration diagram showing one embodiment of a capstan used in the method of the present invention.

FIG. 6 is a configuration diagram showing another embodiment of a capstan used in the method of the present invention.

FIG. 7 is a configuration diagram showing one embodiment of a meandering forming means used in the method of the present invention.

FIG. 8 is a configuration diagram showing another embodiment of the meandering forming means used in the method of the present invention.

FIG. 9 is a partial perspective view showing one embodiment of a conventional self-supporting optical cable with a slit.

FIG. 10 is a partial perspective view showing one embodiment of a conventional extra-length self-supporting optical cable with a slit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Self-supporting optical cable with extra length with slit 2 Optical fiber cable core 3 Sheath 4 Optical cable part 5 Hanging line 6 Hanging line 7 Neck 8 Slit 11 Extruder 12 Slit part 13 Extra length forming part 13a Capstan 14 Cooling water tank 14a Meandering means 19 Cable side groove 20 Suspension line side groove

Continued on the front page (72) Inventor Yoshio Ishibashi 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Factory, Hitachi Cable Co., Ltd. (72) Inventor Kenji Ishii 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Cable Co., Ltd. Hidaka Factory (72) Inventor Shigeru Iwata 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable Co., Ltd. Hidaka Factory

Claims (4)

[Claims] 1. An optical cable section is supported and connected to a substantially linear suspension line section via a plurality of neck sections provided at predetermined intervals along the length thereof, and an extra length is provided for the optical cable section. A self-supporting optical cable with an extra length with a slit, wherein the self-supporting optical cable with slits is meandering vertically and vertically below the hanging wire portion. 2. The slit pitch between the necks is 100.
2. The self-supporting optical cable with slits according to claim 1, wherein the length of the self-supporting optical cable is from 0.1 mm to 1000 mm. 3. The neck portion is formed to have a substantially trapezoidal cross section, and its dimensions are the diameter of the hanging wire portion D ₁ and the diameter of the optical cable portion D.
₂ (D ₁ <D ₂ ), the length in the length direction of the optical cable portion is 5 mm to 100 mm, and the thickness in the radial direction is
2.0mm~3 / 4D ₁ in suspension wire side, according to claim 1 or 2 slit excess length containing self-supporting optical cable, wherein the optical cable side is 2.0mm~3 / 4D _2. 4. A suspension line and an optical fiber cable core are arranged and sent out in parallel, and a sheath made of a thermoplastic resin is collectively extruded and coated on the outer periphery thereof to form a suspension line portion and an optical cable portion, and these are formed. A plurality of necks made of a thermoplastic resin are intermittently connected to form a gourd-shaped cross-section, and before these sheaths and necks are solidified, a half-shaped hanging wire side groove through which the hanging wire passes and an optical cable portion are formed. An extra length is formed in the optical cable portion with respect to the suspension line portion by passing through a capstan having an outer diameter difference with a half-shaped cable side groove portion that passes therethrough, and then an optical cable is provided to hold the extra length of the optical cable. The straight section is formed so as to meander in the vertical and longitudinal directions below the suspension line section, and then the sheath and the neck section are formed so as to cool and solidify. A method for manufacturing a self-supporting optical cable with a litter and extra length.