JPH10333006A - Production of aerial optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a process for producing an aerial optical fiber cable capable of obviating the occurrence of crossing of intermediate parts during production and improving the yield of products. SOLUTION: The aerial optical fiber cable is produced by simultaneously feeding a supporting wire body 14 and an optical fiber cable core 16 into a cross head die 21 of an extruder, subjecting both to integral extrusion coating to integrate the supporting wire 11 and the optical fiber cable 13 with a connecting part 12, intermittently separating this connecting part 12 in a longitudinal direction before the resin of this part solidifies, to form separated parts 18, feeding the wire and the cable in this state into a delivery means 24C arranged to a hemicircumferential shape and cooling the supporting wire 11 and the optical fiber cable 13 while taking off both along the hemicircumference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-supporting overhead optical fiber cable in which a support wire and an optical fiber cable are connected and integrated at a connecting portion, and the optical fiber cable has a slack (excess length). Related to the production method.

[0002]

2. Description of the Related Art The present inventors have proposed a self-supporting type of overhead optical fiber cable and a method of manufacturing the same in Japanese Patent Application No. 8-10436. FIG. 5 shows an example of this overhead optical fiber cable. This overhead optical fiber cable is roughly composed of a support wire 11, a connecting portion 12, and an optical fiber cable 13. The support line 11 is
It is composed of a support wire main body 14 made of a galvanized steel twisted wire or the like, and a covering 15 made of a synthetic resin such as polyethylene which covers the support wire main body 14.

The connecting portion 12 connects and integrates the support wire 11 and the optical fiber cable 13, thereby suspending the optical fiber cable 13 with the support wire 11. The connection portion 12 hangs from the bottom of the support wire 11. The optical fiber cable 13 has a wall-like shape having a continuous thickness of about 1 to 4 mm extending to the top of the optical fiber cable 13 and is made of a synthetic resin such as polyethylene. The optical fiber cable 13 includes a cable core 16 containing a large number of optical fiber cores and a sheath 17 made of a synthetic resin such as polyethylene and covering the cable core 16.

The connecting portion 12 has a support wire 11
Are formed in the form of a plurality of slit-shaped separating portions 18, 18... The length of the separation section 18 is, for example, about 50 cm, and the adjacent separation sections 1
The interval between 8 and 18 is, for example, about 5 cm. The length and interval of the separation part 18 can be arbitrarily changed. Further, the optical fiber cable 13 has a slack at the position where the separating portions 18, 18... Of the connecting portion 12 are formed, and the slack is formed on the side of the support wire 11 by changing the direction substantially alternately. ing. In other words, the optical fiber cable 13 is meandering left and right with respect to the linear support wire 11.
Due to the meandering of 3, the optical fiber cable 13 has a surplus (slack) of about 0.1 to 0.7% with respect to the support wire 11.

[0005] With this structure, a tensile force or strain due to the tensile force is not applied to the optical fiber cable 13 or is reduced. Further, the optical fiber housed inside is difficult to move. Also,
Since the cross wind from the side of the cable passes through the gap formed by the separating portion 18 during the aerial laying, lift due to the cross wind (force acting in the upward direction of the cable) is less likely to occur, and this lift is generated. Dancing (low-frequency vibration of the cable) caused by this is suppressed.

Next, a method for manufacturing the overhead optical fiber cable will be described. FIG. 6 shows an example of a method for manufacturing this overhead optical fiber cable. In the figure, reference numeral 21 denotes a cross-head die for extrusion coating attached to an extruder. The optical fiber cable core 16 and the support wire main body 14 are simultaneously fed into the crosshead die 21 from an inlet hole of the mandrel, and a molten resin such as polyethylene is supplied from an extruder (not shown). Thus, an intermediate product N in which the resin is coated around the optical fiber cable core 16 and the support wire main body 14 and the connecting portion 12 is formed is obtained.

[0007] As shown in FIG. 7, the intermediate product N is continuously led out of the exit hole of the crosshead die 21 with the support wire 11 positioned below and the optical fiber cable 13 positioned above. By arranging the supporting wire 11 having a heavy weight below, the connecting portion 12 is formed in a straight state by the weight.

[0008] A separation portion forming device 22 is provided on the exit hole side of the crosshead die. The separation portion forming device 22 has a sharp blade (not shown), and the blade is intermittently advanced or retracted toward the intermediate product N, so that the intermediate product N coming out of the crosshead die 21 is removed. While the resin forming the connecting portion 12 is still in a semi-molten state, a linear cut is made in the resin to form the separating portions 18 intermittently. As shown in FIG. 8, the intermediate product N in which the linear separating portions 18 are intermittently formed substantially at the center of the connecting portion 12 by the separating portion forming device 22 is then sent to the primary cooling water tank 23. Then, it is cooled and the resin on the surface thereof is semi-solidified and sent to the extra-length forming pulley 24.

The extra length forming pulley 24 has a diameter of 30 cm to 2 cm.
It is of an annular shape of about 00 cm, and rotates at a constant speed in the direction of the arrow in the figure. This extra length forming pulley 2
4, the intermediate product N is wound around the circumference and travels in the direction of the arrow. At the time of this winding,
As shown in FIG. 9, the supporting wire 11 and the optical fiber cable 1 are attached to the outer peripheral surface of the extra-length forming pulley 24 by the tension caused by the winding.
3 will be in contact.

Since the diameter of the optical fiber cable 13 and the diameter of the support wire 11 are different from each other and the diameter of the optical fiber cable 13 is larger, of the intermediate products N wound around the extra length forming pulley 24, 13 is larger than the winding diameter of the support wire 11. Since the extra-length forming pulley 24 rotates at a constant speed, the peripheral speed of the optical fiber cable 13, that is, the traveling speed is lower than the supporting line 1.
1 will be faster than the traveling speed. This allows
By winding the intermediate product N around the extra-length forming pulley 24, the traveling speed of the optical fiber cable 13 becomes faster than the traveling speed of the support wire 11.

The difference between the two traveling speeds is that the optical fiber cable 13 is partially separated from the support wire 11 at the separation portions 18, 18... When the intermediate product N moves away from the extra length forming pulley 24. Therefore, the separation units 18 and 18
... appears as a sag. Therefore, the intermediate product N moving away from the extra-length forming pulley 24 is in a state where the optical fiber cable 13 is slack at the positions of the separation parts 18, 18,..., And exhibits a meandering state as shown in FIG. .

The intermediate product N in this state is immediately sent to the secondary cooling water tank 25, where it is completely cooled and the resin is solidified. Thus, an aerial optical fiber cable having the appearance shown in FIG. 5 is continuously obtained, and is appropriately wound up on a winding drum or the like to obtain a product.

According to such a manufacturing method, the optical fiber cable core 16 and the support wire main body 14 can be manufactured in one manufacturing line.
The resin coating on the optical fiber cable, the formation of the connecting portion 12, and the provision of the sag to the optical fiber cable 13 can be performed in one step at a time, and the intended overhead optical fiber cable can be manufactured extremely efficiently. However, in the above-described manufacturing method, when the intermediate product N is wound around the extra length forming pulley 24 over one round, the winding start position of the intermediate product N and the winding end position intersect on the extra length forming pulley 24, May come in contact. At this time, since the resin forming the outermost layer (the covering body 15, the connecting portion 12, and the cable sheath 17) of the intermediate product N is not sufficiently solidified, the intersection may deform the outermost layer, though rarely. Occurred.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method of manufacturing an overhead optical fiber cable which does not cause an intersection of intermediate products N and can improve the product yield.

[0015]

The object of the present invention is to simultaneously feed a support wire main body and an optical fiber cable core to a crosshead die of an extruder, extrude and collectively coat the support wire and the optical fiber cable at a joint. The resin of the connecting portion is intermittently separated in the longitudinal direction while the resin is not solidified, and in this state, the traveling speed of the optical fiber cable is higher than the traveling speed of the support line, and while taking both of them, it is cooled and cooled. In manufacturing an overhead optical fiber cable, when the traveling speed of the optical fiber cable is set higher than the traveling speed of the support wire and both are taken out, a delivery means arranged in a semicircular shape is provided, and along the semicircle, In this method, the intermediate product consisting of the support wire and the optical fiber cable is taken along a semicircle. Because, it does not occur intersection of the intermediate product.

As another method, when the traveling speed of the optical fiber cable is set higher than the traveling speed of the support line and the two are taken, the optical fiber cable is moved at a speed higher than the feed speed of the support line. For extruding the optical fiber cable in a direction in which the optical fiber cable is pulled out, and the pushing speed of the optical fiber cable is made faster than the traveling speed of the support wire. In other words, the running speed of the optical fiber cable can be made faster than that of the support wire by pulling the optical fiber cable in the pulling direction by the pushing means. In this method, since the support wire and the optical fiber cable run in a straight line, the intermediate product composed of these does not cross again.

[0017]

FIG. 1 shows an example of the present invention, and FIG. 2 shows a state in which the excess length forming portion 24A shown in FIG. 1 is viewed from above. With respect to the method of manufacturing the overhead optical fiber cable of the present invention, an overhead optical fiber cable can be manufactured in the same manner as the method shown in FIG. Therefore,
Hereinafter, a method of forming an extra length of the optical fiber cable 13 which is a feature of the present invention will be described. In the extra-length forming portion 24A, a plurality of pairs of cylindrical rollers 24a and 24b are formed in a pair, having a radius of 15 cm to 100 cm, and a radius of substantially 20 cm to 4 cm.
Delivery means 24 which is arranged in a semicircular shape of about 0 cm and sends out both the optical fiber cable 13 and the support wire 11
C is formed.

The rollers 24a and 24b are shaped like, for example, truncated cones as shown in FIG. That is, the rollers 24a arranged so that the area of the upper surface is large and the rollers 24b arranged so that the area of the lower surface is large are combined. A groove 24d corresponding to the outer peripheral surface of the optical fiber cable) is provided, so that the optical fiber cable 13 and the support wire 11 both come into contact with the rollers 24a and 24b and are sent out. Accordingly, the optical fiber cable 13 and the support wire 11 are supported, and it is possible to prevent the connecting portion 12 from being bent due to the weight of the optical fiber cable 13. Such a truncated conical roller 24a, 24b is connected to the above-mentioned extra length forming section 2.
In the case of the arrangement at 4A, as the inclination angles of the side surfaces of the rollers 24a and 24b are larger, the difference in running speed between the optical fiber cable 13 and the support wire 11 becomes larger, and the amount of slack increases. Therefore, the amount of slack can be increased or decreased by adjusting the inclination angle of the side surface. In this example, a roller is used as the feeding means 24C. However, the present invention is not limited to this as long as the intermediate product N can be fed in a semicircular shape.

Meanwhile, in forming the excess length of the optical fiber cable 13, the intermediate product N which has been cooled in the primary cooling water tank 23 shown in FIG. 24A. And roller 2
As the 4a and 24b rotate at a constant speed, they run semicircularly along these arrangements.

Since the side surfaces of the rollers 24a and 24b are inclined between the optical fiber cable 13 and the support wire 11 as described above, the running speed difference between the optical fiber cable 13 and the support wire 11 becomes semicircular. In traveling, the traveling speed of the optical fiber cable 13 becomes faster than the traveling speed of the support line 11. In this way, an effect similar to that of winding the intermediate product N around the extra-length forming pulley is obtained, and the difference between the two traveling speeds is determined when the intermediate product N is sent from the delivery means 24C to the preceding step. In the portions 18, 18,..., The slack (excess length) of the optical fiber cable 13 appears.

According to this method, the feeding means 24C is arranged in a semicircular shape, and the intermediate product N runs along the semicircular shape along the semicircular shape, so that the intermediate products N do not intersect. In such a manufacturing method, if the diameter of the semicircle is changed by changing the arrangement of the rollers 24a and 24b, the slack increases, and if the diameter is increased, the slack decreases.

FIG. 4 shows another example of the extra length forming method of the present invention. The extra length forming portion 24B shown in FIG. 4 is arranged in place of the extra length forming pulley 24 shown in FIG. I do. In the extra length forming portion 24B, a pair of cylindrical rollers 26 is formed.
a, 26b are linearly arranged in pairs, and the pushing means 2
6C is configured. As shown in FIG. 4B or FIG. 4C, the side surfaces of the rollers 26a and 26b are in contact with the optical fiber cable 13 but not with the support wire 11.

In the formation of the extra length of the optical fiber cable 13, the intermediate product N, which is cooled in the primary cooling water tank 23 shown in FIG.
It is sent to the extra length forming unit 24B. When the intermediate product N is fed at a constant speed by another take-up means in the direction indicated by the arrow in the drawing, the rollers 26a and 26b are rotated so that the speed is higher than the feed speed. The optical fiber cable 13 is pushed out. With this configuration, the traveling speed of the optical fiber cable 13 can be made higher than the traveling speed of the support wire 11 whose traveling speed is determined by the other pickup means. Optical fiber cable 13 in section 18
A slack can be formed. In other words, the running speed of the optical fiber cable 13 can be made faster than that of the support wire 11 by pulling the optical fiber cable 13 in the pulling direction by the pushing means 26C. In this example, the rollers 26a and 26b are used as the pushing means 26C, but the present invention is not limited to this as long as the optical fiber cable 13 can be pushed straight out.

In this method, the running speed of the optical fiber cable 13 can be changed by adjusting the rotation speed of the rollers 26a and 26b by a motor or the like, and the rotation of the rollers 26a and 26b is increased to increase the light speed. By increasing the traveling speed of the fiber cable 13 and increasing the difference between the traveling speed of the optical fiber cable 13 and the traveling speed of the support wire 11, the slack amount of the optical fiber cable 13 can be increased. For example, support line 1
When the traveling speed of the optical fiber cable 13 is about 5 m / min, the traveling speed of the optical fiber cable 13 can be adjusted to about 5.005 to 5.035 m / min. This method uses rollers 26a,
Since the 26b is arranged in a straight line, the space of the excess length forming portion can be reduced, and the intermediate product N does not cross, so that the product yield is improved and the overhead optical fiber cable can be stably manufactured. can do.

[0025]

As described above, according to the present invention, an appropriate slack (extra length) is formed in an optical fiber cable.
It is difficult to apply tensile force and distortion due to this when laying overhead, etc., the optical fiber stored inside is difficult to move,
Furthermore, a self-supporting overhead optical fiber cable in which dancing does not easily occur can be efficiently manufactured with a high product yield. Further, the slack amount of the overhead optical fiber cable can be easily adjusted. Further, the method of pulling the optical fiber cable in the take-off direction has an advantage that a space for arranging the extra length forming portion is small.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a method for manufacturing an overhead optical fiber cable of the present invention.

FIG. 2 is a configuration diagram showing an enlarged main part of FIG. 1;

FIG. 3 is a view showing an example of a roller used in a production method example of the present invention.

FIG. 4 is a configuration diagram showing a main part of another example of a method for manufacturing an overhead optical fiber cable of the present invention.

FIG. 5 is a perspective view showing an overhead optical fiber cable having a slack in the optical fiber cable.

FIG. 6 is a perspective view showing an example of a method for manufacturing a conventional overhead optical fiber cable.

FIG. 7 is a perspective view showing an intermediate product in the manufacturing method shown in FIG.

8 is a perspective view showing an intermediate product in the example of the manufacturing method shown in FIG.

FIG. 9 is a configuration diagram showing an enlarged main part of FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Support line, 12 ... Connection part, 13 ... Optical fiber cable, 14 ... Support line main body, 16 ... Cable core, 18 ... Separation part, 21 ... Crosshead Dies, 22: Separation part forming device, 23: Primary cooling water tank, 24A: Extra length forming part, 24B: Extra length forming part, 24C: Feeding means, 25 ... 2 Next cooling water tank, 26C ... extrusion means

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroto Watanabe 1440, Mukurosaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant (72) Inventor Suehiro Miyamoto 1440, Musaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant

Claims (2)

[Claims] 1. The supporting wire main body and the optical fiber cable core are simultaneously fed into a crosshead die of an extruder, and are simultaneously subjected to extrusion coating to integrate the supporting wire and the optical fiber cable at a connecting portion. During the solidification, the fiber is intermittently separated in the longitudinal direction, and in this state, the traveling speed of the optical fiber cable is higher than the traveling speed of the support line, and both are taken off. When the traveling speed of the optical fiber cable is made faster than the traveling speed of the support line to take out both, a delivery means arranged in a semicircular shape is provided, and the support line, the optical fiber cable and the A method for producing an optical fiber cable. 2. The supporting wire main body and the optical fiber cable core are simultaneously fed into a crosshead die of an extruder, and are collectively extruded and covered to integrate the supporting wire and the optical fiber cable at a connecting portion. During the solidification, the fiber is intermittently separated in the longitudinal direction, and in this state, the traveling speed of the optical fiber cable is higher than the traveling speed of the support line, and both are taken off. When the traveling speed of the optical fiber cable is higher than the traveling speed of the support line and the two are taken, an extruding means is provided for pushing out the optical fiber cable in a direction in which the optical fiber cable is taken at a speed higher than the feed speed of the support line. A method for producing an aerial optical fiber cable, wherein the traveling speed of the optical fiber cable is made faster than the traveling speed of the support wire by the pushing means.