JP5391131B2 - Tape core unit and optical fiber cable - Google Patents

Description

  The present invention relates to a tape core unit and an optical fiber cable.

2. Description of the Related Art Conventionally, there is an optical fiber cable in which a plurality of tape core wires are accommodated at high density and the outer periphery is covered with a jacket.
The “tape core wire” refers to a plurality of optical fiber core wires arranged in a horizontal row and integrated (for example, JIS C 6838). As an integration method, there is a method in which a plurality of optical fiber cores arranged in a horizontal row are collectively covered with an ultraviolet curable resin or the like.

  Patent Document 1 discloses a tape core unit in which at least two optical fiber cores are integrated by arranging them in a horizontal row and similarly integrated tape cores are connected by a low-rigidity member. Has been.

  Patent Document 2 discloses an optical fiber cable in which a plurality of optical fiber cores arranged in a horizontal row are integrated to form a laminated band, and an outer periphery is covered with foamed polyethylene to integrate them. It is disclosed.

JP-A-1-137208 Japanese Utility Model Publication No. 1-157307

In FIG. 14, the external view or sectional drawing of a common optical fiber cable and a tape core wire is shown.
The optical fiber cable C accommodates a tape core T that is twisted at a constant pitch in the axial direction of the cable. The optical fiber cable C shown in FIG. 14 is bent. In this case, bending is also applied to the tape core T accommodated therein.

  The tape core T is obtained by integrating four optical fiber cores Fa to Fd. The tape core T shown in FIG. 14 is bent in the width direction. When bending is applied in the width direction, a large distortion occurs in the outermost optical fiber core Fa. When bending is performed in a direction (valley fold) opposite to the bending direction (mountain fold) shown in FIG. 14, large distortion occurs in the outermost optical fiber core wire Fd.

  The distortion of the outermost optical fiber core Fa depends on the bending radius Rb with respect to the tape core T and the distance Rf between the outermost optical fiber cores of the tape core T. That is, the 4-core tape core T and the more multi-core tape core have a larger distance Rf than the tape core having a smaller number of cores, and when the bending in the width direction is applied, the distance Rf is larger. As a result, the distortion of the outermost optical fiber core Fa increases. Therefore, it becomes difficult to form a cable using the 4-core tape core T or a multi-core tape core.

  An object of the present invention is to provide a tape core unit and an optical fiber cable that can alleviate the distortion of the outermost optical fiber core when the tape core is bent in the width direction.

According to the present invention,
While having a plurality of connected bodies that are single optical fiber core wires,
For a plurality of the connected bodies arranged in parallel in the axial direction, comprising a connecting portion for connecting the adjacent connected bodies in the width direction,
The connecting portion connects three or more connected bodies ,
In the case where the distance between the outermost optical fiber cores among the connected bodies to be connected is Rf1, and the optical fiber cores having the same number of cores as the connected bodies are arranged in a horizontal row. When the distance between the outermost optical fiber cores is Rf2, while maintaining the state of Rf1 <Rf2 ,
The connecting portion has a curved shape,
When the external force is applied to the connecting portion, the shape of the connecting portion is changed so that all or a part of the connected bodies are connected in a horizontal row .
Moreover, according to the present invention,
While including a plurality of connected bodies that are two or more optical fiber core wires,
For a plurality of the coupled bodies arranged in parallel in the axial direction, a coupling portion coupling the adjacent coupled bodies in the width direction, and
In the case where the distance between the outermost optical fiber cores among the connected bodies to be connected is Rf1, and the optical fiber cores having the same number of cores as the connected bodies are arranged in a horizontal row. When the distance between the outermost optical fiber cores is Rf2, while maintaining the state of Rf1 <Rf2,
The connecting portion has a curved shape,
When the external force is applied to the connecting portion, the shape of the connecting portion is changed so that all or a part of the connected bodies are connected in a horizontal row.

  Moreover, the optical fiber cable which accommodated the tape core unit of Claim 1 and coat | covered the outer periphery with the jacket is provided.

  ADVANTAGE OF THE INVENTION According to this invention, when the bending of the width direction is added to the tape core wire, distortion of the optical fiber core wire of the outermost layer can be relieved. Moreover, according to the tape core wire of this invention, manufacture is easy and it can make it hard to produce an injury at the time of optical fiber cable manufacture. Furthermore, it has a collective fusing property as in the prior art.

It is a schematic sectional drawing of a tape cable core unit. It is a schematic sectional drawing of the tape core wire unit in which a connection part is linear shape. It is a comparison figure of a tape core unit and a general tape core. It is a schematic sectional drawing of the tape core wire unit with which the 4-core optical fiber core wire was connected. It is a schematic sectional drawing of the tape core wire unit with which the 8-fiber optical fiber core wire was connected. FIG. 3 is a schematic cross-sectional view of a tape core unit in which four two cores are connected. It is a schematic sectional drawing of the tape core wire unit with which two 4-core tape core wires were connected. FIG. 3 is a schematic cross-sectional view of a tape core unit in which four two cores are connected. It is a schematic sectional drawing of the tape core wire unit whose connection position is not on the centerline in a cross section. It is a schematic sectional drawing of the optical fiber cable which accommodates a tape core unit. It is a schematic sectional drawing of the optical fiber cable which accommodates a tape core unit. It is a figure which shows a measurement system. It is a figure which shows an experimental result. It is an external view of a general optical fiber cable and a tape core wire.

  The configuration of the tape core unit and the optical fiber cable in the present embodiment will be described in detail with reference to the drawings. In addition, this embodiment is an example and this invention is not limited to this.

FIG. 1 shows a schematic cross-sectional view of the tape core unit 10.
The tape core unit 10 includes an optical fiber core 1, a tape coating 2, and a connecting portion 3.

  The optical fiber core wire 1 is composed of an optical fiber 1a, a primary coating 1b, and a secondary coating 1c, and is a core wire having a diameter of 0.25 mm. The optical fiber 1a is made of quartz glass and is covered with a primary coating 1b and a secondary coating 1c. The primary coating 1b and the secondary coating 1c are, for example, ultraviolet curable resins.

  The tape coating 2 is, for example, an ultraviolet curable resin, and collectively coats the two optical fiber cores 1 arranged in a horizontal row with the axial direction parallel. In the present embodiment, a core wire in which two or more optical fiber core wires 1 are integrated is referred to as a “tape core wire”. Also, a unit in which two or more tape cores are integrated is called a “tape core unit” and is distinguished from a “tape core”.

  The 2-core tape core wire T1 is a core wire in which two optical fiber core wires 1 are collectively covered with a tape coating 2 and integrated.

The connecting portion 3 is, for example, an ultraviolet curable resin, is a member having an elastic modulus of about 10 Mpa to 200 Mpa, and is configured to hold a curved shape. The connecting portion 3 connects the two-core tape core wires T1 with the curved shape.
Normally, the connecting portion 3 has a curved shape as shown in FIG. 1. However, when an external force is applied (for example, when the tape core unit 10 is sandwiched between fused fiber folders), the connecting portion 3 has a straight shape. Two two-core tape core wires T1 are connected in a straight line shape.

FIG. 2 is a schematic cross-sectional view of the tape core unit 10 in which the connecting portion 3 has a linear shape.
As shown in FIG. 1, the tape core unit 10 normally maintains the curved shape and connects the two-core tape cores T1 to each other as shown in FIG. 1, but a flat plate or the like (for example, a fusion fiber folder). When sandwiched between the two, the connecting portion 3 has a linear shape as shown in FIG.

  Returning to FIG. 1, the angle α <b> 1 is an angle formed by intersecting the center line in the width direction of the two two-core ribbon T <b> 1, and when the connecting portion 3 has a curved shape, 20 ° <α1 <180 °. . The angle α1 is α1 = 180 ° when the connecting portion 3 is linear.

FIG. 3 shows a comparative view of the tape core unit 10 and a general tape core T. FIG.
The tape core unit 10 and the tape core T shown in FIG. 3 are common in that the four optical fiber cores 1 are integrated, but the distance (Rf1) between the outermost optical fiber cores is the same. , Rf2) are different. In the tape core unit 10, two two-core tape cores T1 are connected while maintaining an angle α1, and the connecting portion 3 has a curved shape, so that Rf1 <Rf2.

  When bending is applied in the width direction, the distortion of the outermost optical fiber core 1 depends on the distance between the outermost optical fibers. From Rf1 <Rf2, the distortion of the outermost optical fiber core 1 in the tape core unit 10 is smaller than the distortion of the outermost optical fiber Fa in the tape T.

  In addition, even if the connection part 3 is a linear shape or another shape, if it is a tape core wire unit satisfy | filling Rf1 <Rf2, the distortion of the optical fiber core wire 1 of the outermost layer in a unit can be relieve | moderated.

Hereinafter, variations of the tape core unit will be described with reference to FIGS.
FIG. 4 shows a cross-sectional view of the tape core unit 11 in which four optical fiber cores are connected.
The tape core unit 11 includes four optical fiber cores 1 and a plurality of connecting portions 3. The tape core unit 11 is not a “tape core unit” because the single optical fiber cores 1 are connected to each other and the tape cores are not connected to each other. It can be said to be an “optical fiber core unit”. However, here, for convenience, the single optical fiber core wire 1 is regarded as a “tape core wire”, and the unit shown in FIG. 4 is referred to as a tape core wire unit 11.

FIG. 5 shows a cross-sectional view of the tape core unit 12 to which eight optical fiber cores are connected.
The tape core unit 12 includes an eight-core optical fiber core 1 and a plurality of connecting portions 3. The tape core unit 12 is not necessarily connected to each other, so it can be said that it is not an “tape core unit” but an “optical fiber core unit”. The unit shown in 5 is called a tape core unit 12.

FIG. 6 shows a cross-sectional view of the tape core unit 13 in which four 2-core tape cores are connected.
The tape core unit 13 includes four two-core tape cores T1 and a plurality of connecting portions 3. As described with reference to FIG. 1, the two-core tape core T1 is a core wire in which the two-fiber optical fiber cores 1 are collectively covered with the tape coating 2 and integrated.
The connection part 3 connects the two-core tape core wires T1 adjacent to each other in a curved shape.

FIG. 7 is a cross-sectional view of the tape core unit 14 in which two 4-core tape cores are connected.
The tape core unit 14 is configured by two four-core tape cores T2 and a connecting portion 3. The 4-fiber ribbon T2 is different from the 2-fiber ribbon T1 in that the 4-fiber optical fiber 1 is integrated, and the other configurations are the same.
The connecting portion 3 connects the four-core tape core wires T2 adjacent to each other in a curved shape.

FIG. 8 shows a cross-sectional view of a tape core unit 15 in which four 2-core tape cores are connected.
The tape core unit 15 includes four two-core tape cores T1 and a plurality of connecting portions 3. As described with reference to FIG. 1, the two-core tape core T1 is a core wire in which the two-fiber optical fiber cores 1 are collectively covered with the tape coating 2 and integrated.
The connecting portion 3 alternately connects the two-core tape core wires T1 adjacent to each other while maintaining the curved shape.

FIG. 9 shows a cross-sectional view of the tape core unit 16 whose connection position is not on the center line in the cross-section.
The tape core unit 16 is constituted by two two-core tape cores T1 and the connecting portion 3. As described with reference to FIG. 1, the two-core tape core T1 is a core wire in which the two-fiber optical fiber cores 1 are collectively covered with the tape coating 2 and integrated.
The connection part 3 connects the two-core tape core wires T1 adjacent to each other in a curved shape. Further, the connecting portion 3 connects the two-core tape cores T1 at a position shifted by a predetermined distance from the center line in the cross section when the optical fiber cores 1 are arranged in a horizontal row.

  The angle α2 has a lower limit angle (α2min) smaller than the lower limit angle (α1min = 20 °) when the connection position is on the centerline in the cross section because the connection position of the connecting portion 3 is not on the centerline in the cross section. That is, α1min> α2min, and therefore, the distance Rf1 between the optical fiber cores 1 in the outermost layer can be made smaller than the angle α1.

FIG. 10 shows a cross-sectional view of the optical fiber cable 20 that houses the tape core unit 15.
The optical fiber cable 20 includes a tension member 21, a grooved spacer 22, a tape core unit 15, a presser winding 23, and a sheath 24. The optical fiber cable 20 is generally called an SZ twisted tape slot type cable or the like. Alternatively, as shown in FIG. 10, an optical fiber cable 20 including 400 optical fiber cores 1 is called a 400-fiber SZ twist slot type cable or the like.

  The tension member 21 is made of a member such as a copper wire and has an allowable tension of a certain value or more in the axial direction. The tension member 21 protects the tape core unit 15 against the tension when the tape core unit 15 is pulled in the axial direction.

  The grooved spacer 22 includes five grooves that are twisted in the axial direction. The five grooves have a structure in which the twisting direction is reversed at a constant pitch.

  As described with reference to FIG. 8, the tape core unit 15 is configured by connecting the adjacent two-core tape cores T <b> 1 in a curved shape by alternately connecting the bending directions by the connecting portions 3.

  The presser winding 23 is a water absorbing tape made of plastic, polyethylene, or the like, and protects the tape core unit 15 from water.

  The sheath 24 is a protective layer made of polyethylene or the like, and covers each member (21 to 23) constituting the optical fiber cable 20.

FIG. 11 is a cross-sectional view of another optical fiber cable 30 that houses the tape core unit 15.
Similar to the optical fiber cable 20 of FIG. 10, the optical fiber cable 30 includes a tension member 31, a grooved spacer 32, a tape core unit 15, a presser winding 23, a sheath 24, and the like. The optical fiber cable 30 is generally called a unidirectional twisted tape slot type cable or the like. Or the optical fiber cable 30 comprised including the 400 optical fiber core wire 1 as shown in FIG. 11 is called a 400-core one-way twist slot type cable.

FIG. 12 shows a measurement system for bending strain.
Bending strain refers to strain that occurs when an optical fiber cable in a straight state is wound around a mandrel having a certain diameter half a turn. The bending strain is measured for each of the optical fiber cable in a straight state and the optical fiber cable when wound around a mandrel, and is calculated from the difference. The mandrel used is a cylinder having a height of about 10 cm and a diameter φ of about 50 mm to 600 mm.
For the measurement of bending strain, a strain distribution measurement technique called BOTDA (Brillouin Optical Time Domain Analysis) was adopted. NEUBRESCOPE NBX-6000 was used as a strain distribution measuring device.

In FIG. 13, the measurement result of a bending strain and the experimental result about collective fusion property are shown.
The measurement of the bending strain is as shown in FIG. 12, and FIG. 13 shows the value of the maximum bending strain.
Regarding the collective fusing property, the case where the optical fiber core wires 1 could be fused ten times out of 10 when the optical fiber core wires 1 were arranged in a horizontal row with the axial direction parallel to each other was marked as ◯. In addition, Furukawa Electric's fuser S122 was used as the fuser.

The following five tape core units were used as experimental objects.
(1) A tape core unit 12 (see FIG. 5) in which eight optical fiber cores 1 are connected.
(2) Tape core unit 13 in which four 2-core tape cores T1 are connected (see FIG. 6).
(3) Tape core unit 15 in which four 2-core tape cores T1 are connected (see FIG. 8).
(4) Tape core unit 14 (see FIG. 7) in which two 4-core tape cores T2 are connected.
(5) The tape core unit 14 (see FIG. 7) in which the elastic modulus of the connecting portion 3 is increased.

  Moreover, the tape core wire used as a comparison object is a core wire in which eight optical fiber core wires 1 are arranged in a horizontal row with the axial direction being parallel and are collectively covered with the tape coating 2.

  Both the test object and the comparison object are common in that eight optical fiber cores 1 are used, and differ in the presence or absence of a curved shape. In other words, the distance between the outermost optical fiber cores is different between the test object and the comparison object.

  According to the measurement results of the bending strain, the test objects (1) to (5) all had a value of the maximum bending strain smaller than that of the comparison object.

  According to the experimental results on the collective fusing property, all of the above (1) to (5), which were the test objects, were ◯ as in the conventional tape core wire used as the comparison object.

  As described above, according to the present embodiment, when the tape core unit 10 and the conventional tape core T are compared, Rf1 <Rf2. Therefore, the bending strain of the outermost optical fiber core wire 1 can be reduced.

  Moreover, the tape core unit 10 may be a tape core unit 11 or 12 to which the single optical fiber cores 1 are connected as a variation.

  Moreover, the tape core unit 10 may be tape core units 13 to 16 in which two or more cores T1 or T2 are connected as a variation.

  Further, when an external force is applied, the optical fiber cores 1 or the optical fiber cores T1 (T2) are arranged in a horizontal row in the tape core units 10 to 16 with the axial direction being parallel. Therefore, it can be easily fused by being sandwiched by the fuser.

  Further, since the connecting portion has a curved shape, Rf1 <Rf2 can be maintained.

  Further, the distance Rf1 between the outermost optical fiber cores can be further reduced by shifting the connecting position by a predetermined distance from the center line of the cross section.

  Moreover, said tape core unit 10-16 is applicable to the optical fiber cable 20 or 30. FIG.

DESCRIPTION OF SYMBOLS 1 Optical fiber core wire 2 Tape coating | cover 3 Connection parts 10-16 Tape core unit T1, T2 Tape core wire 20, 30 Optical fiber cable 21, 31 Tension member 22, 32 Groove spacer 23, 33 Holding winding 24, 34 Sheath

Claims (4)

While having a plurality of connected bodies that are single optical fiber core wires,
For a plurality of the connected bodies arranged in parallel in the axial direction, comprising a connecting portion for connecting the adjacent connected bodies in the width direction,
The connecting portion connects three or more connected bodies ,
In the case where the distance between the outermost optical fiber cores among the connected bodies to be connected is Rf1, and the optical fiber cores having the same number of cores as the connected bodies are arranged in a horizontal row. When the distance between the outermost optical fiber cores is Rf2, while maintaining the state of Rf1 <Rf2 ,
The connecting portion has a curved shape,
The connecting portion is a tape core unit in which all or part of the connected bodies are connected in a horizontal row by changing the shape when an external force is applied . While including a plurality of connected bodies that are two or more optical fiber core wires,
For a plurality of the connected bodies arranged in parallel in the axial direction, comprising a connecting portion for connecting the adjacent connected bodies in the width direction,
In the case where the distance between the outermost optical fiber cores among the connected bodies to be connected is Rf1, and the optical fiber cores having the same number of cores as the connected bodies are arranged in a horizontal row. When the distance between the outermost optical fiber cores is Rf2, while maintaining the state of Rf1 <Rf2 ,
The connecting portion has a curved shape,
The connecting portion is a tape core unit in which all or part of the connected bodies are connected in a horizontal row by changing the shape when an external force is applied . The connecting portion connects the connected bodies at positions deviated by a predetermined distance from a center line of a cross section when the connected bodies are arranged in a horizontal row in the same cross section. Item 3. The cable core unit according to item 1 or 2 . The optical fiber cable which accommodated the tape core unit as described in any one of Claims 1-3 , and coat | covered the outer periphery with the jacket.

Images