JP2996134B2 - Manufacturing method of optical fiber cable with suspension wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical fiber cable with a suspension line having an extra length in an optical fiber cable. And a method for manufacturing an optical fiber cable with a suspension wire, which improves the reliability.

[0002]

2. Description of the Related Art Generally, when an optical fiber cable with a suspension wire is subjected to tension due to natural phenomena such as tension at the time of cable laying, tension at the time of tightness, wind pressure or the like, if the tension of the suspension wire is extended by about 0.2%, it is general. It is said. Therefore, if the length of the suspension cable is the same as the length of the optical fiber cable, the optical fiber cable is also extended by 0.2% with the extension of the suspension cable, and the optical fiber in the optical fiber cable is also extended by about the same amount. There are problems that transmission loss increases and life is remarkably reduced.

[0003] Therefore, an optical fiber cable with extra-long suspension wire is currently being developed. Conventionally, the extra length of the optical fiber cable with the extra length has a cable extra length of 0.2.
%, There is a pre-hanger type optical fiber cable with a hanging wire. FIG. 10 shows the structure, and a hanging wire 1 with a coating is shown.
And an optical fiber cable 2 and a support 3 for supporting and fixing these at a predetermined pitch. The optical fiber cable 2 has a thickness of 0.
About 2% longer, with extra length. How to put extra length,
The suspension wire and the optical fiber cable were fixed with a support while applying tension to only the suspension wire.

[0004] In this method of manufacturing an optical fiber cable with a prehanger-type hanging wire, the hanging wire is extrusion-coated to manufacture a coated hanging wire 1, while the optical fiber cable core is extrusion-coated to manufacture an optical fiber cable 2. The coated suspension wire 1 and the optical fiber cable 2 are molded at a predetermined pitch,
A support 3 for supporting and fixing these is attached.

[0005]

However, the above-mentioned conventional method for manufacturing a pre-hanger type optical fiber cable with a hanging wire has the following problems.

(1) In order to make an optical fiber cable with a suspension line, three steps of an extrusion coating step of a suspension line, an extrusion coating step of an optical fiber cable core, and a molding operation step are required, so that it takes many days to manufacture, and the cost is increased. Becomes

(2) When the extra length is added, a large tension must be applied to the suspension line, which requires a large-scale apparatus. Further, it is difficult to adjust the surplus length to a desired size.

(3) When mounting the support, the mold is manufactured in units of a certain number of pitches.
Due to the molding, the working speed is slow, which further increases the cost and prolongs the delivery time.

(4) When extending the manufactured cable,
Since there is a projection made of a support, the workability is very poor, such as being hooked on a guide such as a gold wheel.

It is an object of the present invention to solve the above-mentioned problems, to provide a method of manufacturing an optical fiber cable with a suspension wire which can be manufactured at a high speed, can be supplied at a short delivery time and is inexpensive, and has good workability of drawing. .

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a suspension cable and an optical fiber cable core are arranged and sent out in parallel, and the outer periphery of the cable is collectively extruded with a sheath to form a suspension cable. parts, neck, in the method for producing a gourd-shaped hanging wires with optical fiber cable having an optical fiber cable portion, after extrusion covering the sheath, cap
Pre-cooling is performed before the winding of the stun, and then the suspension wire and the optical fiber cable are wound around a capstan having an arbitrary diameter in a state where the suspension wire and the optical fiber cable are arranged in parallel. Due to the difference from the bending radius of the optical fiber cable, an extra length is added to the optical fiber cable portion, and the optical fiber cable portion is cooled when the capstan is wound to maintain the extra length.

Further , the present invention provides a suspension cable and an optical fiber cable.
Cores in parallel with each other and send them out.
The sheath is extruded and covered, and the suspension line, neck, optical fiber
The sheath is formed by extrusion coating the sheath.
After that, the hanging wire section and the optical fiber cable section
Wrap it around a capstan of any diameter with it arranged,
Bending radius of the suspension part when winding and optical fiber cable
Due to the difference from the bending radius of the optical fiber cable
Section with extra length, and the capsta
Gourd type optical fiber with suspension wire
In the method for manufacturing an ive cable, after the above capstan is wound, it is wound around a plurality of capstans plural times and cooled.
Is what you do .

[0013]

[Function] A suspension wire and an optical fiber cable core are arranged and sent out in parallel, and the outer periphery of the cable is extruded and covered with the sheath at a time, so that the suspension wire has a smaller diameter than the suspension wire through a neck portion smaller in diameter than the suspension wire. A so-called gourd-type optical fiber cable with a suspension line, to which an optical fiber cable section having a large diameter is connected, is manufactured. In the optical fiber cable with a suspension line, the suspension section and the optical fiber cable section are integrated, so that there is no need to attach a support, and since extrusion coating is performed at a time, the production speed is high, and there are no protrusions. Therefore, wire drawing workability is good.

After the sheath is extruded and covered, when the suspension section and the optical fiber cable section are wound in parallel with a capstan having an arbitrary diameter while being arranged in parallel, the difference between the diameter of the suspension section and the diameter of the optical fiber cable section is obtained. As a result, a difference occurs between the bending radius of the suspension wire portion and the bending radius of the optical fiber cable portion, and the optical fiber cable portion is wound longer because of this difference, so that an extra length is required. In this state, if the sheath is solidified by cooling, the extra length can be maintained in the optical fiber cable portion.

Since the extra length escapes until the sheath is solidified to some extent, cooling during the winding of the captan also has the role of maintaining the extra length, but utilizing the fact that the extra length hardly enters when the sheath is solidified by cooling. The surplus length can be adjusted by changing the degree of cooling. If the pre-cooling is performed after the extrusion coating and before the winding, the degree of cooling in the wound state changes, so that the extra length can be adjusted.

By cooling the capstan by winding it around a plurality of times, the cooling capacity is improved, so that the production speed can be increased.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a method of manufacturing an optical fiber cable with a suspension wire according to the present embodiment. As shown in FIG.
The suspension wire 4 made of, for example, a plurality of galvanized steel wires is delivered to the extruder 9 from the suspension wire delivery drum 17. Further, an optical fiber cable core 5 formed by collecting one or a plurality of optical fiber cores is sent out from an optical fiber cable sending drum 16 to an extruder 9. At this time, the suspension wire 4 and the optical fiber cable core 5 are arranged in parallel at a predetermined interval and fed into the extruder 9.

In the extruder 9, the outer periphery of the suspension wire 4 and the optical fiber cable core 5 are collectively extruded and covered with a sheath so as to be connected in parallel with a predetermined distance therebetween. Optical fiber cable 18
make. Thereby, the coated suspension wire and the optical fiber cable can be simultaneously formed by one extrusion coating, and both can be connected to each other. In addition, as a sheath material, PVC (polyvinyl chloride), PE (polyethylene), or the like is preferable.

As shown in FIGS. 2 (a) and 2 (b), the optical fiber cable 18 with a hanging wire is one in which the hanging wire 4 and the optical fiber cable core 5 are integrated by a gourd-type sheath 6. It is composed of a hanging wire portion 7, a neck portion 20 having a smaller diameter than the hanging wire portion 7, and an optical fiber cable portion 8 connected to the hanging wire portion 7 via the neck portion 20 and having a larger diameter than the hanging wire portion 7. Is presented.

Such an optical fiber cable with a hanging wire 18
Is made by the extruder 9, the optical fiber cable 18 with the suspension wire is naturally cooled by air cooling, and wound around the capstan 11 while the sheath is in a semi-cured state. Also at the time of this winding, the hanging wire portion 7 and the optical fiber cable portion 8 are arranged in parallel.

As shown in FIG. 3, the capstan 11 has a columnar shape, and its outer peripheral surface is flat.
Any diameter can be used as the diameter D of the capstan 11. The optical fiber cable 18 with a stub is provided on the outer peripheral surface of the capstan 11 with the stub 7 and the optical fiber cable 8.
Are wound so as to touch each other.

At the time of this winding, as shown in FIG. 3, since the diameter r of the hanging wire portion 7 and the diameter d of the optical fiber cable portion 8 are different, the bending radius of the hanging wire portion 7 wound around the capstan 11 ( D / 2 + r / 2) and the bending radius (D / 2 + d / 2) of the optical fiber cable portion 8,
Due to this difference, the optical fiber cable section 8 is wound longer, so that a surplus ratio of λ = (D + d) / (D + r) is obtained. In order to obtain an arbitrary extra length ratio, the diameter D of the capstan 11 may be changed when the diameter r of the suspension line portion 7 and the diameter d of the optical fiber cable portion 8 are already determined.

After being wound around the capstan 11, the suspension-equipped optical fiber cable 18 is sent to the cooling water tank 13 for cooling.
Completely solidify the sheath so that the cable outline does not collapse. Then, the optical fiber cable 18 with a suspension wire is wound up by the winding drum 15 via the winding track 14.
When the cooling water tank 13 is not provided, the production line may be extended, and the section by natural cooling may be extended.

By the way, at the time of winding with the capstan 11, the sheath is still semi-cured, so that the sheath is not tight and the sheath is not covered with the optical fiber cable core 5 inside the sheath.
Even if it does not yet adhere, even if you add extra length with the capstan 11,
As soon as you pass the capstan 11, the extra length escapes. For this reason, it is necessary to provide a water tank 12 for capstan in which the capstan 11 is immersed, and to perform cooling by water cooling in a state where the optical fiber cable 18 with a suspension wire is wound around the capstan 11. Further, by utilizing the fact that the extra length is difficult to harden when the sheath is solidified by cooling, the temperature or water level of the water to be injected into the capstan water tank 12 is changed, and the time of the winding with the capstan 11 is changed. The extra length can be easily adjusted by changing the cooling degree.

As shown in FIG. 4, the capstan 11
By changing the water level of the capstan water tank 12 as a cooling condition while keeping the diameter of the tubing constant, the excess length ratio can be changed. The horizontal axis in FIG. 4 is the diameter D of the capstan 11,
The vertical axis is the surplus rate. Curve a is the capstan tank 1
The curve b shows the relationship between the diameter D and the extra length in a state in which water is filled up to half in 2, and in a state in which water is completely filled. As shown in the figure, the extra length ratio changes depending on the degree of cooling. Note that the curve c
Is a characteristic in a case where water is cooled between the extruder 9 and the capstan 11 in addition to a state in which water is completely contained.

If it is desired to increase the production speed of the optical fiber cable 18 with a hanging wire, it is necessary to enhance the cooling effect. This involves extruder 9 and capstan 1 as in the embodiment of FIG.
A cooling water tank 10 having a cooling capacity better than air cooling may be provided as a pre-cooling means. By using the pre-cooling means, the cooling effect can be enhanced, the production speed can be increased, and the productivity of the cable can be improved. In addition to this advantage, fine adjustment of the extra length of the optical fiber cable section 8 is possible. As a method of finely adjusting the extra length ratio by the pre-cooling means, there is a method of changing the cooling capacity of the pre-cooling means. There is also a method of changing the position of the pre-cooling means between the extruder 9 and the capstan 11 without changing the cooling capacity of the pre-cooling means. This is a fine adjustment method of the surplus length rate, in which the excess length rate increases when the pre-cooling means is brought closer to the extruder 9 side, and conversely, when the pre-cooling means is brought closer to the capstan 11 side. Yes, fine adjustment can be performed easily and easily.

FIG. 6 shows an optical fiber cable 18 with a suspension wire in which the optical fiber cable section 8 has an extra length in this way. Each of them is viewed from the suspension line 7 side, and the neck is omitted. In FIG. 6A, the rigidity of the optical fiber cable core 5 is strong, and the optical fiber cable portion 8 is meandering on both sides of the suspension line portion 7 almost uniformly. FIG.
6B and FIG. 6C show the optical fiber cable core 5.
The optical fiber cable portion 8 is biased to one side of the suspension line portion 7. 6 (b) has a longer margin than that of FIG. 6 (c). Further, when a slit is provided in the neck portion, the slit pitch is long as shown in FIG. 6B, and the slit pitch is short as shown in FIG. 6C.

Next, another embodiment in which the winding method is changed will be described.

The manufacturing method shown in FIG. 7 is obtained by adding a wound capstan 19 to the capstan 11 of the manufacturing method shown in FIG. The wound capstan 19 adjacent to the capstan 11 in the axial direction is for improving the cooling effect.
The optical fiber cable 18 with a suspension wire can be wound a plurality of times. In this case, as shown in FIG. 7 (b), after the optical fiber cable 18 with the suspension wire is wound around the capstan 11, the optical fiber cable 18 is wound around the capstan 19 a plurality of times, cooled, and sent to the cooling water tank 13. .

FIG. 8 shows the capstan 11 and the wound capstan 19. Crosshead 9a of extruder 9
Is wound around the capstan 11 for about 3/4 turn, is guided by the guide roller group 21, and is wound a plurality of times around the wound capstan 19 attached to the side . The wrapping capstan 19 may be tapered so that the wrapped cable slides sequentially and shifts in the axial direction.

If it is desired to increase the production speed of the optical fiber cable 18 with a hanging wire, the cooling effect has been already described, but one of the methods is to increase the number of windings.
By cooling the capstan 19 an arbitrary number of times in addition to about ／ rotation of the capstan 11, the cooling effect is enhanced.

In each of the embodiments, as a method of adding an extra length to the optical fiber cable portion 8, a method of winding the optical fiber cable portion 8 around a cylindrical capstan 11 having a flat outer peripheral surface has been described.
The present invention is not limited to this. For example, Capstan 1
An inclination or a step may be provided on the outer periphery to make the difference between the bending radius of the suspension line portion 7 and the bending radius of the optical fiber cable portion 8 larger so that a larger extra length can be provided.

In order to make it easy to add extra length, FIG.
As shown in (c), a slit may be provided in the neck 20.

Next, a method of driving the wound capstan 19 will be described.

As shown in FIG. 9 , a capstan motor 22 for driving the wound capstan 19 is mounted on the wound capstan 19.
By driving the winding capstan 19, the load on the winding caterpillar 14 can be reduced. In this case, there are a method of interlocking the capstan motor 22 and the winding track motor 23, and a method of freely using the winding track motor 23 by using a torque motor.

As described above, according to the method of the present invention, an optical fiber cable with a suspension wire can be manufactured in a single extrusion coating step, so that the number of manufacturing days is reduced and the cost can be reduced.

Further, since the hanging wire portion and the optical fiber cable portion are simultaneously extruded and coated in a gourd mold, and this is wrapped around a capstan so that an extra length is provided.
The method of adding extra length is simple. In addition, since the extra length is added, the optical fiber does not need to be stretched by 0.2% or more, which is considered to be a limit in terms of transmission characteristics.

The capstan groove diameters D ₁ and D ₁
By changing ₂ , any extra length can be obtained.

Further, by performing preliminary cooling immediately after extrusion coating, fine adjustment of the excess length can be performed.

Also, the molding speed for mounting the support is not required, the production speed is improved, and there are no protrusions as in the prior art. Very good.

[0042]

The present invention exhibits the following excellent effects.

(1) Since an optical fiber cable with a suspension line is formed at a time by extruding and covering the sheath, the conventional three-step optical fiber cable is reduced to one step, so that the delivery time can be shortened and the cost can be reduced.

(2) The extra length is added by winding the capstan around the capstan in the form of a gourd, and cooling is performed when the capstan is wound, so that the extra length can be easily formed.

(3) According to the configuration of claim 2 , the number of windings can be increased, the cooling effect can be enhanced, and the production speed can be increased.

(4) The molding work of the support, which was conventionally required, is eliminated, the production speed is improved, and the workability of the cable drawing work is improved because there is no protrusion of the support.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method for manufacturing an optical fiber cable with a suspension wire according to the present invention.

FIG. 2A is a cross-sectional view, FIG. 2B is a plan view, and FIG. 2C is a plan view of another embodiment of the optical fiber cable with suspension wires manufactured according to the present embodiment.

FIG. 3 is a view showing a state where an optical fiber cable with a suspension wire is wound around a capstan used in the present embodiment.

FIG. 4 is a diagram showing the relationship between the capstan diameter and the excess length ratio according to the present invention.

FIG. 5 is an explanatory view showing another embodiment of the method of manufacturing an optical fiber cable with a suspension wire according to the present invention.

FIG. 6 is a side view of the optical fiber cable with various hanging wires manufactured according to the present embodiment.

FIG. 7 is a method for manufacturing an optical fiber cable with a suspension wire according to the present invention .
It is an explanatory view showing another embodiment, (a) is a side view,
(B) is a partial plan view.

FIG. 8 shows a capstan used in another embodiment of the present invention;
(A) is a plan view and (b) is a side view of a wound capstan.
You.

FIG. 9 is a method for manufacturing an optical fiber cable with a suspension wire according to the present invention .
It is a top view which shows the other Example of this.

FIG. 10 is a conventional optical fiber cable with a pre-hanger-type hanging wire.
(A) is a sectional view, and (b) is a plan view.

[Explanation of symbols]

 Reference Signs List 4 Suspended wire 5 Optical fiber cable core 6 Sheath (Gourd type sheath) 7 Suspended wire portion 8 Optical fiber cable portion 9 Extruder 11 Capstan

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoji Nomura 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Works, Hitachi Cable Co., Ltd. (72) Inventor Takashi Sugano Hidaka, Hitachi City, Ibaraki Prefecture 5-1-1, Hachimachi, Hidaka Electric Wire Co., Ltd. (56) References JP-A-7-230028 (JP, A) JP-A 8-75969 (JP, A) (58) Fields surveyed ( Int.Cl. ⁶ , DB name) G02B 6/44

Claims (2)

(57) [Claims] 1. A gourd-type hanging wire with a hanging wire portion, a neck portion, and an optical fiber cable portion, wherein a hanging wire and an optical fiber cable core are arranged and sent out in parallel, and the outer periphery thereof is collectively extruded with a sheath. In a method for manufacturing an optical fiber cable, after extruding the sheath ,
Pre-cooling is performed before the winding of the stun, and then the suspension wire and the optical fiber cable are wound around a capstan having an arbitrary diameter in a state where the suspension wire and the optical fiber cable are arranged in parallel. A method for manufacturing an optical fiber cable with a suspension wire, characterized by adding an extra length to the optical fiber cable portion due to a difference from a bending radius of the optical fiber cable, and cooling the optical fiber cable portion at the time of capstan winding in order to maintain the extra length. 2. A suspension cable and an optical fiber cable core in parallel.
Arrange them and send them out, and push the sheath around these
Cover and form the suspension line, neck, and optical fiber cable.
After the sheath is extrusion-coated, the hanging wire
Section and the optical fiber cable section in parallel.
Wrap around the capstan of the desired diameter and suspend it when winding
Between the bend radius of the wire and the bend radius of the optical fiber cable
Due to the difference, add extra length to the optical fiber cable part,
Cooling during capstan winding to maintain the extra length
Gourd type optical fiber cable with suspension
In the method of manufacturing, after winding the above capstan, another
It is characterized by being wound around the capstan several times and cooled
Of manufacturing an optical fiber cable with a hanging wire.