JP4657846B2 - Optical fiber cable manufacturing apparatus and manufacturing method - Google Patents

Description

  The present invention relates to an optical fiber cable manufacturing apparatus and manufacturing method in which one or more optical fiber ribbons are stacked and stored in a plurality of slots (grooves) provided on the outer periphery of a slot rod.

A slot-type optical fiber cable stores one or more optical fiber ribbons in a plurality of slots (grooves) provided on the outer periphery of a slot rod, and presses and winds the outer periphery of the optical fiber tape. The outer cover is provided with a cover (see Patent Document 1). When manufacturing slot-type optical fiber cables, the optical fiber tape cores are stored in the slots to prevent the optical fiber tape cores from jumping out of the grooves and to solve problems such as the presser winding falling into the slots. After that, rough winding is performed on the slot rod, and presser winding is performed thereon.
JP-A-4-36712

Here, the conventional technique has the following problems to be solved.
In recent years, in slot-type optical fiber cables, the number of slots provided on the outer periphery of the slot rod is increased without changing the outer diameter, and the number of optical fiber ribbons that can be accommodated in one cable is increased. There are attempts to reduce the diameter.

  However, in such a cable, since the number of slots is increased without changing the outer diameter, the thickness of the slot rib between adjacent slots is inevitably reduced. As a result, there is a problem that the strength of the slot rib becomes insufficient and the slot rib is crushed or deformed (swelled). It has been found that the crushing and deformation of the slot rib occurs particularly at the portion where the coarse winding is wound. If the slot ribs are crushed or deformed, the optical fiber ribbon may be pressed by the slot ribs, coarse windings, presser windings, etc., leading to an increase in transmission loss of the optical fibers.

  The present invention has been made paying attention to the above points, and provides an optical fiber cable manufacturing apparatus and a manufacturing method capable of reducing the diameter of a cable without causing crushing or deformation of a slot rib. For the purpose.

In each embodiment of the present invention, the above-described problems are solved by the following configurations.
<Configuration 1>
A slot rod supply for continuously supplying a slot rod having a plurality of slots for receiving optical fiber ribbons along the longitudinal direction on the outer surface to the production line, and a plurality of optical fiber ribbons as described above A core wire supply that continuously supplies the manufacturing line; a dropping mechanism that drops the plurality of optical fiber tape core wires into one of the slots of the slot rod; and the optical fiber tape core wire in the manufacturing line. A slot winding rod comprising a coarse winding mechanism for winding a fibrous coarse winding on the outer peripheral surface of the slot rod immediately after being accommodated in the slot, and a slot rib constituting a partition between each slot of the slot rod is made of high-density polyethylene, and the slot rod The width of the slot on the outer surface portion of a is a (mm), and the rough winding by the rough winding mechanism When the winding tension per book is b (g / piece), the rough winding mechanism controls the winding tension of the rough winding so that the value of b / a is 250 or more and 1000 or less. Optical fiber cable manufacturing equipment.

  When a fiber-like rough winding is used, the force with which each fiber is pressed against the surface of the slot rib is lower than that of a string-like one because stress is dispersed. Therefore, the slot rib can be prevented from being crushed and deformed (swelled). Note that if the coarse winding is wound with a too high tension, the slot rib may be crushed or deformed (swelled), but conversely, if the tension is too low, the winding position is shifted and the function of the rough winding is impaired. If winding is performed under the above conditions, the optimum winding state can be maintained, and the slot ribs are not crushed or deformed (swelled). A plurality of coarse windings may be wound.

<Configuration 2>
The apparatus for manufacturing an optical fiber cable according to Configuration 1, wherein the coarse winding is a collection of fibers of 500 d (denier) or more and 1500 d or less.

  When the fiber is coarsely wound and the thickness thereof is selected appropriately, the effect of preventing deformation of the slot rib becomes remarkable. In addition, the winding tension can be easily controlled. If the fiber denier number is less than 500d, the coarse winding is too thin and stress is concentrated, so that the surface of the slot rib is liable to be crushed or deformed (swelled). On the other hand, if the denier number of the fiber exceeds 1500 d, the coarse winding becomes too thick and the appearance of the cable may be deteriorated.

<Configuration 3>
The optical fiber cable manufacturing apparatus according to Configuration 2, wherein the rough winding is made of an aramid fiber or a nylon fiber.

  As the above-mentioned rough winding, aramid fibers and nylon fibers are preferable because they do not stretch during rough winding.

  In the present invention, the relationship between the slot width of the outer surface portion of the slot rod and the winding tension per coarse winding is controlled to an appropriate value. Hereinafter, embodiments of the present invention will be described in detail for each example.

FIG. 1 is a cross-sectional view showing a general slot type optical fiber cable.
As shown in the figure, a slot rod 2 made of high-density polyethylene is extruded on the outer periphery of the tension member 1. A plurality of slots 3 are provided on the outer surface of the slot rod 2 along the longitudinal direction. An optical fiber ribbon 4 is accommodated in these slots 3. An outer skin 5 is coated on the outermost periphery.

  It is the slot rib 6 that constitutes the partition between the slots 3. As the number of slots 3 increases, the portion of the slot rib 6 that is particularly close to the tension member 1 becomes thinner. When rough winding is applied to the outer periphery of the slot rib 6, stress exceeding the allowable limit is applied to the slot rib 6, so that the slot rib 6 is crushed or deformed (swelled).

FIG. 2 is a cross-sectional view showing the optical fiber ribbons accommodated in the slots.
As shown in the figure, the optical fiber ribbon 4 has a plurality of optical fibers 7 that are collectively covered 8. When the slot rib 6 shown in FIG. 1 is crushed or deformed (swelled), the optical fiber ribbon 4 having such a configuration receives a lateral pressure inside the slot 3 and is locally applied to the optical fiber 7. Bending occurs. This causes an increase in optical signal transmission loss. If the coarse winding is wound with a tension that is too high, the slot rib 6 will be crushed or deformed (swelled). Conversely, if the tension is too low, the position of the coarse winding will be shifted and the function of the rough winding will be impaired.

FIG. 3 is a schematic diagram showing an optical fiber cable production line.
As shown in the figure, the slot supply 10 includes a drum or the like that continuously supplies the slot rod 2 to the production line. The slot rod 2 includes a plurality of slots 3 already described on the outer peripheral surface. The core wire supplies 11, 12,... Are constituted by bobbins that supply the optical fiber tape core wires 4 to these slots 3. The number of the core wire supplies 11 and 12 is increased or decreased according to the number of the core wires housed in the slot 3.

  The dropping mechanism 13 has a function of dropping the optical fiber ribbon 4 supplied from the core supplies 11, 12,... Into any slot 3 of the slot rod 2. The configuration of this apparatus may be the same as a conventionally well-known apparatus. That is, although not shown in the drawing, an aggregate plate for collecting the optical fiber ribbons 4 and a dropping jig are provided.

  The coarse winding mechanism 18 has a function of winding the coarse winding 19 around the outer peripheral surface of the slot rod 2 immediately after the optical fiber ribbon 4 is received in the slot 3. This winding mechanism may be the same as that conventionally known. The slot rod 2 to which the rough winding 19 has been applied is then subjected to a presser winding or jacket (not shown).

  In order to maintain the strength of the slot rod 2, at least the slot rib 6 is preferably made of high-density polyethylene. Here, the rough winding mechanism 18 controls the winding tension of the rough winding within a certain range. The rough winding tension is performed, for example, by attaching a controller to a bobbin for supplying rough winding and adjusting the torque. The coarse winding tension is controlled to be constant in consideration of the take-up speed of the slot rod 2 and the winding speed of the coarse winding.

FIG. 4 is a partial side view showing a slot rod subjected to rough winding.
As shown in the figure, a plurality of slots 3 are provided on the outer peripheral surface of the slot rod 2. An optical fiber ribbon 4 is accommodated in the slot 3. A rough winding 19 is wound around the outer periphery. Here, two sets of coarse windings 19 are wound in opposite directions.

  Such a winding method is called cross winding. The cross winding pitch was 10 mm. For the rough winding 19, for example, a nylon fiber having a thickness of 840 denier was used, and the slot rod 2 was made of high-density polyethylene.

  The depth of the slot 3 is 2.3 mm, the outer diameter of the slot rod 2 is 12.5 mm, and the slot width a of the outer surface portion of the slot rod is 0.69 mm as the value of the illustrated portion. The optical fiber ribbon 4 housed in the slot 3 is housed in 5 pieces each having a width of 1.1 mm and a thickness of 0.3 mm.

  A pressing roll (not shown) is applied to the outer periphery of the slot rod 2 to cover a jacket 5 (FIG. 1) made of plastic such as polyethylene.

FIG. 5 shows the occurrence of crushing and deformation (swell) of the slot rib 6 and the state of the rough winding while changing the winding tension b of the rough winding, where a is the slot width of the outer surface portion of the slot rod. It is a chart which shows the result of observation.
In this evaluation, the slot width a of the outer surface portion of the slot rod was fixed to a constant 0.69 mm, and the winding tension of the rough winding was changed from 80 g / piece to 1000 g / piece.
The condition of the crushing and deformation (swelling) of the slot ribs and the state of rough winding were visually observed after performing the temperature cycle of −30 to + 70 ° C. three times on the cable after covering the jacket.

  Moreover, the presence or absence of the increase in the transmission loss before and behind a temperature cycle was investigated by OTDR (Optical Time Domain Reflectometer). As a result, very good results were obtained when b / a was 250 or more and 1000 or less.

  In addition, although the case where an aramid fiber was used for rough winding and the case where a nylon fiber was used was experimented, the same result was obtained in any case.

FIG. 6 is a chart showing the result of observing the state of crushing and deformation (swelling) of the slot rib and the appearance of the jacket when the thickness of the coarse winding is changed.
In this evaluation, the winding tension of the coarse winding is 400 g / piece, the slot width a of the outer surface portion of the slot rod is fixed to 0.69 mm, and the thickness of the coarsely wound fiber is in the range of 100 d (denier) to 2500 d. Changed.

It is a cross-sectional view showing a general slot type optical fiber cable. It is a cross-sectional view which shows the optical fiber tape core wire accommodated in a slot. It is the schematic which shows the manufacturing line of an optical fiber cable. It is a partial side view which shows the slot rod which gave the rough winding. It is a graph which shows the result of having evaluated the situation of the crushing and deformation | transformation (swelling) of a slot rib at the time of changing the winding tension | tensile_strength of rough winding, and the increase in transmission loss. It is a graph which shows the result of having evaluated the state of the crushing and deformation | transformation (swell) of a slot rib, and the external appearance of a jacket at the time of changing the thickness of rough winding.

Explanation of symbols

2 Slot rod 4 Optical fiber ribbon core wire 10 Slot supply 11, 12, ... Core wire supply 13 Drop mechanism 18 Coarse winding mechanism 19 Coarse winding

Claims (2)

A slot rod having a plurality of slots of the same width a from the outer surface portion to a portion close to the tension member for accommodating the optical fiber ribbon along the longitudinal direction on the outer surface, A slot rod supply that continuously supplies the production line;
A plurality of fiber optic tape cores each having the same width, which are continuously supplied to the production line;
A dropping mechanism for dropping the plurality of optical fiber ribbons into one of the slots of the slot rod;
In the production line, comprising a coarse winding mechanism for winding a fiber-like coarse winding on the outer peripheral surface of the slot rod immediately after the optical fiber tape core wire is accommodated in the slot,
Slot ribs constituting partition walls between the slots of the slot rod are made of high-density polyethylene, and the rough winding is a collection of fibers of 500d (denier) to 1500d,
When the slot width of the slot rod is a (mm) and the winding tension per one rough winding by the rough winding mechanism is b (g / piece),
The outer diameter of the slot rod is 12.5 mm, the depth of the slot is 2.3 mm, and the width a of the five slots on the outer surface portion of the slot rod is 0.69 mm.
The apparatus for manufacturing an optical fiber cable, wherein the rough winding mechanism controls the rough winding to have a winding tension b of 400 or less and a b / a value of 250 to 1000. In the manufacturing apparatus of the optical fiber cable according to claim 1,
The apparatus for producing an optical fiber cable, wherein the rough winding is a collection of aramid fibers or nylon fibers.

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