JP4974159B2 - Tape slot type cable - Google Patents

Description

  The present invention relates to a tape slot type cable, and more particularly to a tape slot type cable capable of reducing the slot diameter.

Tape slot type cables in which slot grooves for mounting a plurality of tape core wires are spirally provided have been put into practical use.
Along with the increase in the number of fibers and the increase in the density of optical fiber cables, there has been a demand for reducing the size and weight of the optical fiber cables.
For example, in Patent Document 1, an optical fiber accommodation rate per cable outer diameter is increased by providing a plurality of concentric slot grooves.
Japanese Utility Model Publication No. 7-10709

However, although the tape slot type cable having the structure of Patent Document 1 can increase the optical fiber accommodation ratio per outer diameter of the cable, the structure is complicated, so that it is difficult to manufacture and the manufacturing cost increases. is there.
On the other hand, in a conventional tape slot type cable having a slot groove of one layer on the outer periphery of the slot, the thickness of the tape core wire is usually 0.30 mm or more, and in the slot groove from the viewpoint of an increase in optical fiber transmission loss. The size of the slot groove is set so that the tape stack can be inclined by 34 degrees or more. Therefore, the tape space ratio in the slot groove is 57.9% or less. For this reason, in the conventional tape slot type cable, there is a limit to reducing the diameter of the slot, and it is difficult to reduce the size of the tape slot type cable.
Accordingly, in order to solve the above-described problems, the tape slot type cable of the present invention employs a conventional structure having a single slot groove on the outer periphery of the slot, and can reduce the slot diameter. The purpose is to provide a mold cable.

In order to solve the above problems, a tape slot type cable of the present invention is a tape slot type cable in which a slot groove for mounting a plurality of tape core wires is provided in a spiral shape, and the thickness of the tape core wire is 0.28 mm or less, the slot groove has a flat groove bottom, and the tape stack of the tape core wire is inclined at 17 degrees or more and 24 degrees or less with respect to the groove bottom in the slot groove. In a possible groove size, the tape space ratio of the tape core wire in the slot groove is 64% or more and 75% or less .

  According to the present invention, it is possible to reduce the slot diameter by reducing the slot groove dimension while adopting the conventional structure having one slot groove on the outer periphery of the slot.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of the structure of a preferred embodiment of the tape slot type cable of the present invention.
The tape slot type cable 10 shown in FIG. 1 has a tape core wire 20 composed of eight optical fiber core wires as an example, a slot 11, a plurality of tape core wires 20, a tension bar 12, A presser winding 13 and a sheath 14 are provided. A tension bar 12 is disposed at the center of the slot 11, and the slot 11 has a plurality of slot grooves 30.

  The plurality of slot grooves 30 are formed radially about the tension bar 12. In each slot groove 30, for example, ten tape core wires 20 are stacked along the radial direction. A presser winding 13 is arranged on the outer peripheral surface of the slot 11, and the presser winding 13 prevents the tape core wire 20 from coming out of the slot groove 30. The sheath 14 is made of polyethylene, for example, and covers the outer peripheral surface of the presser winding 13.

  In FIG. 1, the tape lamination inclination angle of the tape core wire 20 laminated in the slot groove 30 is not shown for simplification of illustration, but actually, the slot groove 30 and the tape core wire 20 are not displayed. As shown in FIG. 5, the tape core wire 20 stacked in the slot groove 30 can be inclined with respect to the bottom of the slot groove 30. . The maximum angle at which the tape core wire 20 can be tilted in the slot groove 30 is called a tape stacking tilt angle θ.

FIG. 2 is a cross-sectional view showing a structural example of the tape core wire 20 of FIG.
As shown in FIG. 2, the tape core wire 20 is an eight-core tape core wire composed of eight optical fiber core wires.
The tape core wire 20 shown in FIG. 2 is manufactured as follows, for example.
First, four optical fiber cores 40 having an outer diameter of 0.24 to 0.26 mm are arranged in parallel in a planar shape, and a primary tape coating 41 made of, for example, an ultraviolet curable resin is applied thereto, thereby providing a primary tape unit. Form. In this embodiment, two formed primary tape units are prepared, and the two primary tape units are arranged in parallel in a plane, and the entire primary tape unit is made of a secondary material made of, for example, an ultraviolet curable resin. The tape coating 42 is applied to connect both primary tape units, and the tape core wire 20 is formed.

The optical fiber 40 is a single-mode optical fiber defined in JIS C6835 with a glass optical fiber having an outer diameter of about 125 .mu.m and an outer diameter of 0.24 to 0.26 mm. Is used.
In this embodiment, four optical fiber cores are used as a primary tape unit, and two of them are used as an eight-fiber ribbon. However, the number of optical fiber cores in the primary tape unit is not limited to four. Further, the secondary tape coating is not performed, and the primary tape unit may be configured by eight optical fiber cores, and the number and configuration thereof may be appropriately selected as needed.

In the tape slot type cable 10 of the embodiment of the present invention, a slot groove 30 for mounting a plurality of tape core wires 20 is spirally provided in one direction along the axial direction of the cable 10.
Further, the thickness of the tape core wire 20 in the tape slot type cable 10 is 0.28 mm or less, and the tape stack of the tape core wire 20 can be inclined by 17 degrees or more in the slot groove 30. The tape space ratio of the tape core wire 20 is 64.0% or more.

FIG. 3 shows Examples 1 to 4 of the present invention, a conventional example, and Comparative Examples 1 and 2.
In FIG. 3, the thickness [mm], the width [mm], the number of sheets [sheets / groove], the groove width [mm], the groove height [mm], and the groove width [mm] of the slot groove 30. ], The number of grooves, the rib root thickness [mm] (indicated by F in FIG. 1), the outer diameter [mm] of the slot 11, the thickness [mm] of the sheath 14, and the outer diameter [mm] of the tape slot type cable 10. ], The lamination inclination angle [deg] of the tape core wire 20, the space factor [%] of the tape core wire 20, and the temperature characteristic [dB / km].

Here, the tape core wire space factor is an area ratio of the tape core wire 20 to the cross-sectional area of the slot groove 30.
Further, the temperature characteristic is a change amount of the maximum transmission loss of the optical fiber core 40 mounted on the tape slot type cable 10 at −30 ° C. to + 70 ° C.
In addition, as temperature characteristics for an optical fiber cable to operate | move without a problem, 0.15 dB / km or less is required, More preferably, it is 0.10 dB / km or less.

FIG. 4 shows an example of dimensions of the thickness D and the width T of the tape core wire 20 of the first to fourth embodiments shown in FIG. The thickness D of the tape core wire 20 is 0.28 mm, and the width T is 2.20 mm.
FIG. 5 illustrates a dimension example of the first embodiment shown in FIG. 3 and shows ten tape core wires 20 stacked in the slot groove 30. The slot groove 30 has an upper groove width T1 of 2.7 mm, a groove height H of 3.6 mm, and a lower groove width T2 of 2.5 mm. The lamination inclination angle θ of the tape core wire 20 is 24 degrees.

If the thickness D of the tape core wire 20 exceeds 0.28 mm (design center value, also referred to as the average value of the thickness at each position in the longitudinal direction of the tape core wire), the slot diameter is limited, which is preferable. Absent.
In addition, since a standard outer diameter of 0.24 to 0.26 mm is used as the optical fiber core wire, the lower limit value of the thickness D of the tape core wire 20 is the outer diameter of the optical fiber core wire +0. 02 mm is the limit.
In addition, by making the outer diameter of the optical fiber core smaller than the standard 0.24 to 0.26 mm, the thickness D of the tape core 20 can be further reduced. The cost is increased because it is necessary to manufacture with different specifications.

If the lamination of the tape cores 20 in the slot groove 30 is inclined less than 17 degrees, there arises a problem that the transmission loss of the optical fiber cores tends to increase.
Further, if the stacking angle of the tape core wires 20 is set to be large in the slot groove 30, it is not preferable because the slot diameter is limited. Therefore, the upper limit is preferably 24 degrees.
Similarly, if the tape space ratio in the slot groove 30 is less than 64%, it is not preferable because the slot diameter is limited. Further, if the tape space ratio is too large, the movement of the tape core wire in the slot groove is hindered, resulting in a problem that transmission loss tends to increase. Therefore, the tape space ratio is preferably 75% or less.

  FIG. 6 shows an example of dimensions of Comparative Example 1 in FIG. 3. The groove width G1 of the slot groove 130 is 2.3 mm, the groove height J is 3.4 mm, and the groove width G2 is 2.3 mm. . The lamination inclination angle θ of the tape core wire 120 is 15 degrees.

FIG. 8 shows, for comparison, the dimensions of the conventional tape core wire 220 shown in FIG. 3. The tape core wire 220 has a thickness B of 0.30 mm and a width C of 2.20 mm. .
For comparison, FIG. 9 shows that the tape core wire lamination inclination angle θ in the slot groove 230 of the conventional example shown in FIG. 3 is 34 degrees.

  As shown in FIG. 3, the tape slot type cables of Examples 1 to 4 of the present invention have the temperature characteristic [dB / km] while the tape space ratio of the tape core wire 20 is set to 64% or more. It can be kept at 0.10 dB / km or less. That is, it can be said that the slot size can be reduced by reducing the slot groove size while maintaining the optical transmission characteristics, thereby reducing the size of the tape slot type cable.

  The tape slot type cable 10 according to the embodiment of the present invention is a tape slot type cable in which a slot groove 30 for mounting a plurality of tape core wires 20 is provided in a spiral shape. The thickness of the tape core 20 is 0.28 mm or less, the tape lamination of the tape core 20 is inclined by 17 degrees or more in the slot groove 30, and the tape space ratio of the tape core 20 in the slot groove 30 is Since it is 64% or more, the diameter of the slot can be reduced by reducing the slot groove size while maintaining the optical transmission characteristics.

By the way, this invention is not limited to the said embodiment, A various modified example is employable.
FIG. 7 shows a modification of the first embodiment of the present invention shown in FIG. 5, and a corner 70 at the lower portion of the slot groove 30 is an R portion. That is, in the slot groove 30, the corner portion 70 at the lower part of the slot groove 30 may be an R portion so as not to affect the setting of the lamination inclination angle θ of the laminated tape core wires 20.
Further, the slot 11 of the tape slot type cable 10 shown in FIG. 1 has thirteen slot grooves 30, and ten tape core wires 20 are laminated in each slot groove 30. However, the present invention is not limited to this, and the number of slot grooves and the number of stacked tape cores can be changed.

It is sectional drawing which shows the structural example of preferable embodiment of the tape slot type cable of this invention. It is sectional drawing which shows the structural example of a tape core wire. Examples 1 to 4 of the present invention, a conventional example, and comparative examples 1 and 2 are shown. It is a figure which shows an example of thickness D and width T of one tape core wire of the Example of this invention. It is a figure which shows the example of the slot step of Example 1 of this invention, and the example of the lamination | stacking inclination angle of a tape core wire. It is a figure which shows the example of the slot step of a comparative example, and the example of the lamination | stacking inclination angle of a tape core wire. It is a figure which shows the modification of Example 1 of this invention shown in FIG. It is a figure which shows the dimension of the conventional tape core wire for the comparison. For comparison, it is a diagram showing a tape core wire lamination inclination angle in a conventional slot groove 230. FIG.

Explanation of symbols

10 Tape Slot Type Cable 11 Slot 12 Tension Bar 13 Presser Winding 14 Sheath 20 Tape Core Wire 30 Slot Groove

Claims (1)

A slot slot for mounting a plurality of tape core wires is a tape slot type cable provided in a spiral shape,
The tape core has a thickness of 0.28 mm or less, the slot groove has a flat bottom, and the tape stack of the tape core in the slot groove is not less than 17 degrees and 24 degrees with respect to the groove bottom. A tape slot type cable characterized by having a groove dimension capable of inclining to a degree or less and a tape space ratio of the tape core wire in the slot groove being not less than 64% and not more than 75% .

Images