JP3266345B2 - Manufacturing method of self-supporting cable with slack - 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 for manufacturing a self-supporting cable with a slack in which a cable core is twisted with a slack with respect to a support wire.

[0002]

2. Description of the Related Art A self-supporting cable with a slack is mainly used as a cable structure for an aerial optical fiber cable because it has an advantage that overstress is hardly applied to a cable core. 3 and 4 show the structure of the self-supporting cable 1 with a slack. The cable core 11 and the supporting wire 12 are provided with a neck portion 13 and covered with a common sheath 14 material. The core 11 is rotated at an inversion angle of 360 ° or less (usually 180 °
) And twisted while reversing the direction (so-called SZ twist).

[0003] The above-mentioned cable is usually mounted on a cable core 1 around a support wire 12 using a rotary crosshead.
A sheath 14 having a neck 13 while giving SZ twist to 1
By extrusion coating, and then the extruded cable is introduced into a cooling water bath and cooled.

[0004]

However, the cable manufactured by the above-described method is not suitable for the crosshead shown in FIG.
The cable core 11 that has been twisted to the positions a and b shown by the two-dot chain line moves in the direction of the arrow in the figure due to its own untwisting force and the like while the sheath 14 is solidified in the cooling water tank, As a result, there is a problem that the neck portion 13 is bent and deformed. Immediately after extruding from the crosshead, the above problem can be solved by introducing the cable into the cooling water tank and solidifying the sheath, but there is a limit to the distance that the cooling water tank can be brought close due to the rotation of the crosshead. After all, the bending deformation of the neck 13 cannot be avoided.

When the neck portion 13 is bent and deformed, the desired slack amount of the cable core 11 cannot be obtained accurately, and the neck portion easily expands in accordance with the stretching force when the stretching force is applied to the support wire. However, there is a problem that it is difficult or impossible to form a slit in the neck portion 13 which is usually performed in the next step.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method of manufacturing a self-supporting cable with a slack which does not cause a neck portion to bend and deform.

[0007]

According to the present invention, there is provided a method of manufacturing a self-supporting cable with a slack, wherein a cable core is twisted while reversing the direction at a reversing angle of 360 ° or less with respect to a supporting wire, and both are twisted. A method for manufacturing a self-supporting cable with a slack provided with a neck portion and covered with a common coating material, wherein cooling water is radiated toward a support wire portion of the cable immediately after being extruded from a crosshead. Then, the cable is introduced into a cooling water tank.

[0008]

The cooling water is radiated toward the support line of the cable extruded from the crosshead, whereby the cooling water is dropped on the neck connected to the support line and the neck is immediately solidified. The neck portion is thin, and when directly radiating cooling water, for example, when radiating a water jet from a nozzle disposed around the entire circumference of the cable, the neck portion may be deformed due to the radiation of the cooling water, According to the method of the present invention, the neck is solidified in an extruded state (straight state) without such a problem, so that the above-mentioned problem of the bending deformation does not occur.

Thereafter, the entire cable is cooled by introducing the cable into the cooling water tank. By blowing compressed air between the cooling water radiating section and the crosshead, the cooling water can be prevented from entering the crosshead.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 shows an example of a manufacturing apparatus for realizing a method for manufacturing a self-supporting cable with a slack according to the present invention.

In FIG. 1, reference numeral 2 denotes an extruder having a rotary crosshead 21; 3, a nozzle for emitting cooling water W; and 4, a cooling water tank filled with cooling water. Also, 3
Reference numeral 1 denotes an auxiliary water tank for collecting the cooling water W radiated from the nozzle 3, and 5 is disposed between the outlet of the rotary crosshead 21 and the nozzle 3 for blowing compressed air A from the entire circumference of the cable 1. Air nozzle.

Although the illustration is simplified, reference numeral 10 denotes a supply line comprising a cable core 11 and a support line 12 in FIG. 3, and the supply line 10 is sent to the extruder 2,
The molding machine 2 rotates the cable core 11 around the support wire 12 at a reversal angle of 360 ° or less (normal reversal angle is 180 °).
°, 90 degrees to the left and right around the lowest point of the support line 12.
Swinging is performed), and a sheath 14 having a neck portion 13 is formed by coating an insulating material. The self-supporting cable 1 with a slack having a structure as shown in FIGS. 3 and 4 is obtained. Extruded.

In order to extrude the cable having the above structure, the rotary crosshead 21 has a circular hole through which the support wire 12 passes, a circular hole through which the cable core 11 passes, and a slit for the neck portion 13 which connects these two holes. And a die having a substantially spectacle-shaped extrusion hole and a center positioned at the center of the support wire hole, and rotating the die alternately left and right according to the slack amount of the cable core 11. While having a rotation center (the center of rotation is the center of the support wire hole), a mechanism for extruding the insulating material for the sheath 14 is provided.

The support wire 12 can be made of, for example, a metal stranded wire such as a galvanized steel stranded wire, or a non-metallic wire such as an aromatic polyamide fiber or FRP. May be applied. Cable core 11
Although there is no particular limitation, for example, a plurality of tape-shaped optical fiber core wires are stored in a stacked state in the concave groove of the support member having a plurality of spiral concave grooves formed thereon, and a holding tape is wound thereon. An optical fiber cable core or the like can be exemplified as a suitable one.

Immediately after the cooling water W is extruded from the crosshead 21, the cooling water W is emitted from the nozzle 3 toward the support wire 12 of the cable 1. When the SZ twist reversal angle of the cable core 11 is 360 ° or less, particularly about 180 °, if the cable core 11 is positioned below the support wire 12 and is extruded to meander, the cooling water W is applied to the cable core 11. The support wire 12 is radiated without hindrance, reaches the neck portion 13 through the outer periphery thereof, and cools and solidifies the portion.

FIGS. 2A to 2C show the radiation state of the cooling water W to the above-mentioned neck portion 13. 2A shows a state in which the cable core 11 is directly below the nozzle 3, and FIGS. 2B and 2C show states in which the cable core 11 is on the left and right, respectively. By radiating the cooling water W to the support line 12, the cooling water W reaches the neck 13 connected to the support line 12, and as a result, the neck 13 can be cooled and solidified quickly. In addition, the radiation of the cooling water from the nozzle 3 is sufficient even if the water simply flows without applying a water pressure.

An air nozzle 5 is provided between the nozzle 3 and the crosshead 21. The air nozzle 5 is provided to prevent the cooling water W radiated to the cable 1 from traveling along the neck 13 and the like to enter the crosshead 21. The compressed air A is blown in the direction, and for example, an annular pipe having a large number of ejection holes can be used.

The position where the nozzle 3 is disposed, that is, the position where the cooling water W is radiated, is preferably a position as close to the crosshead 21 as possible, that is, a position where the cooling water W can be radiated immediately after the cable 1 is extruded. In general, the distance L between the crosshead and the nozzle 3 shown in FIG.
mm or less, more preferably 100 mm or less. If the distance L is too long, the neck 13 may be deformed before the cooling water W is radiated.

The cable 1 whose neck 13 has been cooled by the cooling water W from the nozzle 3 is subsequently introduced into a cooling water tank 4, where the entire cable 1 is cooled. Thereafter, the cable 1 is subjected to the above-described step of opening a slit in the neck portion 13 and the like, and a self-supporting cable with slack is completed.

[0020]

According to the method of manufacturing a self-supporting cable with a slack according to the present invention as described above, immediately after being extruded from the crosshead, the neck portion is immediately radiated by radiating cooling water to the supporting wire portion of the cable. As it cools, the neck solidifies without curving. Therefore, the amount of slack in the cable core can be accurately secured, and the slit in the neck in the next step can be easily formed, so that a high-quality self-supporting cable with slack can be provided.

In addition, the cooling of the neck can be sufficiently dealt with even if the cooling water is allowed to flow down to the support wire portion, and there is an advantage that the quality of the cable can be improved without making the manufacturing apparatus complicated and sophisticated as compared with the conventional one. is there.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a manufacturing apparatus for performing a manufacturing method of the present invention.

FIG. 2 is a cross-sectional view showing a state in which cooling water is radiated to a cable.

FIG. 3 is a sectional view of a self-supporting cable with a slack;

FIG. 4 is a side view of a self-supporting cable with slack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Self-supporting cable with slack 11 Cable core 12 Support wire 13 Neck 2 Extruder 21 Rotary crosshead 3 Nozzle 4 Cooling water tank 5 Air nozzle A Compressed air W Cooling water

────────────────────────────────────────────────── ─── Continued from the front page Examiner Hideo Sasano (56) References JP-A-62-288023 (JP, A) JP-A-57-45506 (JP, A) JP-A-62-103914 (JP, A) Opened Sho 62-156907 (JP, U) Opened Sho 63-194309 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/44

Claims (2)

(57) [Claims] 1. The cable core is 360 ° with respect to the support wire.
It is twisted while reversing the direction at the following reversal angle,
And a method for manufacturing a self-supporting cable with a slack in which both are provided with a neck portion and covered with a common coating material, wherein the cable is cooled toward a support wire portion of the cable immediately after being extruded from a crosshead. A method for producing a self-supporting cable with slack, which comprises radiating water and then introducing the cable into a cooling water bath. 2. The method of manufacturing a self-supporting cable with slack according to claim 1, wherein compressed air is blown from the entire circumference of the cable between the cooling water radiating section and the crosshead.