JP2013061524A - Method for manufacturing optical unit and optical fiber cable, and optical unit and optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical unit configured by bundling a plurality of optical fibers, in which the optical fibers in the optical unit can be easily connected to optical fibers of another optical unit, and the diameter of the optical unit can be reduced without loosening the optical fibers configuring the optical units in the vicinity of a terminal and without generating excessive extension or disconnection of a plastic film bundling the optical fibers.SOLUTION: A method includes a step for cylindrically forming a thermoplastic film tape while leaving overlapping part in a circumferential direction of the film tape to form a cylindrical film 3 and a step for storing and integrating an optical fiber group 2 in the cylindrical film 3. An inner diameter of the cylindrically formed cylindrical film 3 is smaller than an outer diameter of the optical fiber group 2.

Description

  The present invention relates to an optical unit manufacturing method in which a plurality of optical fibers are combined, an optical unit manufacturing method, and an optical fiber cable having a structure in which optical units and optical units are assembled.

  Conventionally, as an optical fiber cable, for example, a cable composed of a slot core having a slot groove for accommodating an optical fiber and a sheath covering the periphery of the slot core has been proposed.

  In such an optical fiber cable, when optical fibers are gathered and used in a multi-core configuration, the outer peripheral surface of the optical fiber is colored, and a plurality of optical fibers are divided into small units (hereinafter referred to as “optical units”). Each optical unit is composed of optical fibers of respective colors. A plurality of the optical units are collected and stored in the slot.

  As shown in FIG. 12, the configuration of the optical unit is described in a configuration (loose tube structure) in which a plurality of optical fibers 102 constituting the optical unit 102a are accommodated in a cylindrical loose tube 103, or in Patent Document 1. As described above, there has been proposed a configuration in which a plastic tape is formed into a cylindrical shape, formed into a tube with an adhesive resin, and an optical fiber is accommodated therein to form an optical unit.

  In Patent Document 2, as shown in FIG. 13, as a method of manufacturing an optical unit 102 a that does not require an extruding operation, a film 105 is deformed around the optical fiber group 102 and a sheath is formed. There has been proposed a process comprising a step of fixing the film 105 around the optical fiber group 102 and holding the optical fiber group 102.

  In Patent Document 3, as shown in FIG. 14, an optical unit having a configuration in which a plurality of optical fibers 102 are assembled and a plastic tape 106 is spirally wound around the optical fiber 102 to hold the optical fiber 102. 102a is described.

  In the optical unit 102a in which the plastic tape 106 is spirally wound around the plurality of optical fibers 102, the optical unit 102a cannot be unraveled, and the unity of the optical unit 102a can be maintained. When the optical fiber 102 is taken out in the middle of the optical unit 102a, the space between the plastic tapes 106 can be taken out, and after the take-out, the original state is restored by the elasticity of the plastic tape 106.

  In the configuration in which the plastic tape 106 is spirally wound around the plurality of optical fibers 102, the plastic tape 106 is subjected to heat treatment after being wound, and the plastic tape 106 is curled, or the plastic tape 106 is squeezed. There have been proposed ones that are wound around the optical fiber 102 while providing a spiral bend, and ones in which a plastic tape 106 is spirally formed around the optical fiber 102 by extrusion using a rotary die. Yes.

  Further, as another configuration of the optical unit, as shown in FIG. 15, a configuration (bundle structure) in which a plurality of optical fibers 102 constituting the optical unit 102a are bundled with an identification yarn 104 has been proposed.

  In addition, the structure of the optical fiber cable using the optical unit of these optical fibers is also standardized (Telcordia GR-20 Generic Requirements for Optical Fiber or Optical Fiber Cable).

JP 2002-303769 A Japanese Patent No. 3798057 JP 2007-10917 A

  By the way, in the optical unit 102a having the loose tube structure described above, when the optical fiber 102 is taken out from the loose tube 103 in order to connect the optical fiber 102 in the optical unit 102a to the optical fiber of another optical unit, the loose tube 103 is used. It is necessary to cut a part of the tube with a blade or the like and cut the loose tube 103 into a ring. In such an operation, since the loose tube 103 is thin and the inner surface of the loose tube 103 and the optical fiber 102 are almost in close contact with each other, the optical fiber 102 may be accidentally damaged or cut by a blade. is there. Further, in the intermediate post-branching operation for connecting to another optical fiber at an intermediate position of the optical fiber cable, it is necessary to expose the optical fiber 102 while thinly scraping the side surface of the loose tube 103, and it is necessary to use a special tool. there were.

  Even in the configuration in which the plastic tape described in Patent Document 1 is formed into a tubular shape and formed into a tube with an adhesive resin, it is difficult to take out the optical fiber because the plastic tape is formed into a tubular shape and joined. .

  Further, in order to form the plastic film 105 into a cylindrical shape, it is necessary to pass it through a forming die. However, when the optical unit 102a is to be reduced in diameter, it is necessary to form the plastic film 105 tightly. Also, it is necessary to use a small hole diameter. When the molding die is narrow, there is a possibility that the plastic film 105 and the optical fiber 102 may be disconnected due to being caught when passing through the plastic film 105 and the optical fiber 102.

  A method of forming a sheath by deforming the film 105 around the optical fiber group 102 described in Patent Document 2, or a plastic film 106 or tape spirally formed on a plurality of optical fibers 102 described in Patent Document 3. In the method of winding, at least the plastic films 105 and 106 and the plastic film 105 are heated so that the optical films 102 are heated while the plastic films 105 and 106 are attached, and the films 105 and 106 are brazed in a cylindrical shape or a spiral shape. , 106 must be heated to a temperature near the Tg of the plastic material. In order to heat the surface of the optical film 102 that is in contact with the plastic films 105 and 106 and the plastic films 105 and 106 that are traveling in the production line to a target temperature, a heating furnace that is higher than the target temperature, a heating furnace that has a long heating length, etc. If it is heated too much, the plastic films 105 and 106 will be deformed or broken due to elongation or melting.

  When the plastic films 105 and 106 are stretched and integrated with the optical fiber 102 and mounted on a cable, the extra lengths of the plastic films 105 and 106 and the optical fiber 102 do not match, and the optical fiber 102 meanders. As a result, the transmission loss may increase, or the optical fiber 102 may protrude from the plastic films 105 and 106 and local bending may occur at that portion, thereby increasing the transmission loss. Further, during high-temperature aging for maintaining temperature characteristics, heating fringes of the stretched plastic films 105 and 106 may occur, and transmission loss may further increase.

  Further, in the method of forming a sheath by deforming the plastic film 105 around the optical fiber group 102 and the method of spirally winding the plastic film 106 around the optical fiber group 102, the outer diameter of the optical fiber group 102 is larger than that of the optical fiber group 102. Since the plastic films 105 and 106 cannot be molded or brazed to a small diameter, the optical unit 102a cannot be reduced in diameter.

  In the optical unit 102a having a bundle structure, when the optical fiber 102 in the optical unit 102a is connected to the optical fiber of another optical unit, the identification yarn 104 that bundles the optical fibers 102 is unwound or cut. Thus, the optical fiber 102 can be taken out. However, in the vicinity of the end of the optical fiber cable, the identification yarn 104 is easily unwound with the removal of the sheath. When the identification yarn 104 is unwound, the optical fibers 102 constituting the optical unit 102a are separated, making it difficult to distinguish from the optical fibers constituting the other optical units.

  In addition, since the optical fiber 102 is exposed in the optical unit 102a having the bundle structure, when it is necessary to run the optical unit 102a for a long time at the end of the optical fiber cable, measures such as covering with a protective tube are taken. Necessary and cumbersome.

  Further, in manufacturing the bundle-structured optical unit 102a, the identification yarn 104 is directly wound around the optical fiber 102. Therefore, depending on the winding tension or winding pitch of the identification yarn 104, the transmission loss of the optical fiber 102 may be deteriorated. Therefore, it is difficult to manufacture.

  Therefore, the present invention is proposed in view of the above-described circumstances, and is a method of manufacturing an optical unit in which a plurality of optical fibers are combined, and a method of manufacturing an optical fiber cable having a structure in which the optical units are assembled. An optical unit that makes it easy to connect an optical fiber in an optical unit to an optical fiber of another optical unit and that does not cause the optical fibers constituting the optical unit to be separated in the vicinity of the terminal is manufactured. An optical unit manufacturing method and an optical fiber cable manufacturing method capable of reducing the diameter of the optical unit without causing excessive stretching or disconnection of the plastic film that bundles the optical fibers. With the goal.

  In order to solve the above-described problems and achieve the above object, a method for manufacturing an optical unit according to the present invention has the following configuration.

[Configuration 1]
In a method of manufacturing an optical unit comprising an optical fiber group consisting of a plurality of optical fibers and a cylindrical film that bundles the optical fiber groups, a thermoplastic film tape is formed into a cylindrical shape with overlapping portions in the circumferential direction. A cylindrical film and a step of housing and integrating the optical fiber group in the cylindrical film, and the inner diameter of the cylindrical film when formed into a cylindrical shape is that of the optical fiber group. It is characterized by being smaller than the outer diameter.

[Configuration 2]
In the manufacturing method of the optical unit having the configuration 1, the thermoplastic film tape forming the cylindrical film has a thickness of 0.012 mm to 0.100 mm.

[Configuration 3]
In the manufacturing method of the optical unit having the configuration 1 or the configuration 2, the cylindrical film is characterized in that the outer peripheral surface is coated with an ultraviolet curable resin.

[Configuration 4]
In the manufacturing method of the optical unit having the configuration 1 or the configuration 2, the cylindrical film is coated with a resin on the outer peripheral surface, and applied to the outer periphery of the multiple optical units when manufacturing the multiple optical units. The resin is the same and there is one resin supply system.

[Configuration 5]
In the manufacturing method of the optical unit having the configuration 3, the thermoplastic film tape forming the cylindrical tube is made of a colorless and transparent material, and the ultraviolet curable resin is colored. .

[Configuration 6]
In the method of manufacturing an optical unit having any one of Configurations 1 to 3, the cylindrical film is partially colored at a predetermined location for identification between the optical units. is there.

[Configuration 7]
In the method for manufacturing an optical unit having any one of Configurations 1 to 3, the thermoplastic film tape is characterized in that it is entirely colored in order to distinguish between the optical units.

[Configuration 8]
In the manufacturing method of the optical unit having any one of Configurations 1 to 7, the tension of the film tape when the film tape is taken and assembled with the optical fiber behind the forming die for forming the film tape into a cylindrical shape An adjusting device is provided, and the film tape and the optical fiber are assembled behind the adjusting device.

  The optical unit according to the present invention has the following configuration.

[Configuration 9]
It is manufactured by an optical unit manufacturing method having any one of Configurations 1 to 8.

  Moreover, the manufacturing method of the optical fiber cable which concerns on this invention has the following structures.

[Configuration 10]
In a method for manufacturing an optical fiber cable having a structure in which a plurality of optical units each having a plurality of optical fibers assembled together, a plurality of optical units manufactured by the method for manufacturing an optical unit having any one of configurations 1 to 8 are provided. It is characterized by having made it.

  The optical fiber cable according to the present invention has the following configuration.

[Configuration 11]
It is manufactured by the manufacturing method of the optical fiber cable which has the structure 10.

  In the method for manufacturing an optical unit and the method for manufacturing an optical fiber cable according to the present invention, a step of forming a cylindrical film by forming a thermoplastic film tape into a cylindrical shape having an overlapping portion in the circumferential direction, and a cylinder And the step of housing and integrating the optical fiber group in the cylindrical film, and the inner diameter of the cylindrical film when formed into a cylindrical shape is smaller than the outer diameter of the optical fiber group.

  Therefore, it is easy to manufacture, the optical fiber constituting the optical unit is not scattered in the vicinity of the terminal, and when the optical fiber in the optical unit is connected to the optical fiber of another optical unit, By opening the cylindrical film into a flat shape, the optical fiber can be easily taken out from the cylindrical film, and only the film tape needs to be heated, the heating time can be shortened, and the heating temperature can be lowered. Therefore, there is no fear of disconnection due to excessive elongation or melting of the film tape. Since the film tape is not integrated with the fiber in an excessively stretched state, there is no increase in optical loss due to the difference in the extra length between the film tape and the optical fiber, and the optical fiber does not jump out of the film tape. Since the film tape is formed in a state where there is no optical fiber inside the film tape to be formed into a cylindrical shape, the film tape can be passed through a thin forming die with almost no resistance, and the optical unit can be made thinner.

  That is, the present invention provides an optical unit manufacturing method in which a plurality of optical fibers are combined and an optical fiber cable manufacturing method having a structure in which the optical units are assembled. It is possible to manufacture an optical unit that can be easily connected to a fiber and in which the optical fiber that constitutes the optical unit does not become separated in the vicinity of the terminal. It is possible to provide an optical unit manufacturing method and an optical fiber cable manufacturing method capable of reducing the diameter of the optical unit without causing any stretching or disconnection.

It is sectional drawing which shows the structure of the optical fiber cable using the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is sectional drawing which shows the other example of a structure of the optical fiber cable using the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is a perspective view which shows the structure of the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is a perspective view which shows the other example (what colored a part of cylindrical film) of the structure of the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is a perspective view which shows the other example (what colored the whole cylindrical film) of the structure of the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is the perspective view and sectional drawing which show the other example (what applied UV coating to the cylindrical film) of the structure of the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is the perspective view and sectional drawing which show the other example (what made cylindrical film a double structure) of the structure of the optical unit manufactured by the manufacturing method of the optical unit which concerns on embodiment of this invention. It is a side view which shows the structure of the manufacturing apparatus which implements the manufacturing method of the optical unit in embodiment which concerns on this invention, and the manufacturing method of an optical fiber cable. It is a side view which shows the structure of the manufacturing apparatus which implements the manufacturing method of the optical unit of a comparative example, and the manufacturing method of an optical fiber cable. It is a side view which shows the structure of the manufacturing apparatus which provided the film tape intermediate drawing and tension adjustment dancer after the film tape forming. It is a side view which shows the structure of the manufacturing apparatus of the 60-fiber optical cable which mounted five 12-core optical units. It is a perspective view which shows the structure of the optical unit of the conventional optical fiber cable. It is a perspective view which shows the structure of the optical unit of the conventional optical fiber cable. It is a perspective view which shows the structure of the optical unit of the conventional optical fiber cable. It is a perspective view which shows the other example of a structure of the optical unit of the conventional optical fiber cable.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[Configuration of optical unit and optical fiber cable]
FIG. 1 is a cross-sectional view showing a configuration of an optical fiber cable using an optical unit manufactured by an optical unit manufacturing method according to an embodiment of the present invention.

  As shown in FIG. 1, an optical fiber cable 1 using an optical unit manufactured by an optical unit manufacturing method according to an embodiment of the present invention includes a plurality of optical units 2a each including a plurality of optical fibers 2. This is an optical fiber cable having the above structure.

  The plurality of optical units 2 a are housed in a cylindrical sheath (outer jacket) 6. The sheath 6 is formed as a cylindrical tube. The sheath 6 is formed by extrusion molding so that the entire periphery of the plurality of optical units 2a is covered with polyethylene resin.

  FIG. 2 is a cross-sectional view showing another example of the configuration of the optical fiber cable using the optical unit manufactured by the optical unit manufacturing method according to the embodiment of the present invention. More specifically, FIG. 2 is a cross-sectional view showing a cross section when the optical fiber cable is cut along a plane orthogonal to the longitudinal direction thereof.

  The optical fiber cable 1 uses a slot core 4 having a C-shaped cross section having a cylindrical slot 4a. That is, the optical fiber cable 1 is configured by housing and holding a plurality of optical units 2a in the slot 4a of the slot core 4, and covering the entire slot core 4 with the sheath 6 including the opening 5 of the slot 4a. Composed. The slot 4a is formed linearly along the cable longitudinal direction.

  FIG. 3 is a perspective view showing the configuration of the optical unit manufactured by the method of manufacturing an optical unit according to the embodiment of the present invention.

  The optical unit 2 a includes a plurality of optical fibers (optical fiber group) 2 and a cylindrical film 3 that bundles the optical fibers 2. As the optical fiber 2, an optical fiber, an optical fiber, an optical fiber tape, or the like is used. The optical fiber strand is an optical fiber coated with an ultraviolet curable resin. The optical fiber core wire is obtained by coating a plastic resin on an optical fiber and making its diameter larger than that of the optical fiber strand. The optical fiber ribbon is made of several optical fiber strands arranged in parallel and covered with an ultraviolet curable resin.

  The cylindrical film 3 is obtained by forming a thermoplastic film tape into a cylindrical shape having an overlapping portion 3d in the circumferential direction. As illustrated, the overlapping portion 3d extends linearly in the longitudinal direction of the optical unit 2a. The thermoplastic film tape forming the cylindrical film is made of, for example, PET (Polyethyleneterephthalate) and has a thickness of, for example, 0.012 mm to 0.100 mm.

  In order to manufacture such an optical unit 2a, first, a cylindrical film 3 is formed by forming a thermoplastic flat film tape into a cylindrical shape having an overlapping portion 3d in the circumferential direction. At this time, the inner diameter of the cylindrical film 3 is made smaller than the outer diameter of a plurality of optical fibers (optical fiber group). Then, a plurality of optical fibers 2 are accommodated in the cylindrical film 3, and the optical fibers 2 are bundled and integrated by the cylindrical film 3 to form an optical unit 2a.

  FIG. 4 is a perspective view showing another example of the configuration of the optical unit manufactured by the method of manufacturing an optical unit according to the embodiment of the present invention (in which a part of a cylindrical film is colored).

  In this optical fiber cable 1, as shown in FIGS. 4A and 4B, a colored portion 3 a for identifying between the optical units 2 a at a predetermined portion of the cylindrical film 3. May be provided. The colored portion 3a may be provided on any one surface (the outer peripheral surface or the inner peripheral surface of the cylindrical film 3) of the thermoplastic film tape forming the cylindrical film 3, or the thermoplastic film tape. It may be provided on both sides. In addition, when providing the colored part 3a in the internal peripheral surface of the cylindrical film 3, a transparent thing is used as a thermoplastic film tape.

  Thus, in the optical unit 2a provided with the colored portion 3a, a plurality of optical units 2a can be identified by the color of the colored portion 3a.

  FIG. 5 is a perspective view showing another example of the configuration of the optical unit manufactured by the method of manufacturing an optical unit according to the embodiment of the present invention (the entire cylindrical film is colored).

  The thermoplastic film tape is colored in advance in order to distinguish between the optical units 2a before forming into a cylindrical film 3 by forming into a cylindrical shape. In this case, as shown to (a) and (b) in FIG. 5, the cylindrical film 3 will be colored in order to identify between the optical units 2a.

  Thus, in the optical unit 2a which colored the cylindrical film 3, the some optical unit 2a can be identified with the color of the cylindrical film 3. FIG.

  6A and 6B are a perspective view and a cross-sectional view showing another example of the configuration of the optical unit manufactured by the method of manufacturing an optical unit according to the embodiment of the present invention (a cylindrical film obtained by UV coating).

  In this optical fiber cable 1, as shown in FIGS. 6A and 6B, a cylindrical film 3 is coated with an ultraviolet curable resin coating 3 c on its outer peripheral surface. With this coating 3c, the rigidity of the cylindrical film 3 can be improved and the buckling resistance at the time of small bending of the cylindrical film can be improved. The degree of “small bending” is bending with a radius of about 30 mm. Moreover, in taking out the optical fiber 2 from the cylindrical film 3 to be described later, the coating 3c can be easily broken by a human finger, so that it is not difficult to take out the optical fiber 2 by the coating 3c. Furthermore, by using a transparent material for the film tape and using a colored UV curable resin for the coating material, it is possible to distinguish between the optical units.

  7A and 7B are a perspective view and a cross-sectional view showing another example of the configuration of the optical unit manufactured by the method of manufacturing an optical unit according to the embodiment of the present invention (a cylindrical film having a double structure). .

  In this optical fiber cable 1, as shown in FIGS. 7A and 7B, the cylindrical film 3 has a width of the overlapping portion in the circumferential direction of the thermoplastic film tape. It is more than twice the circumference of.

  In this case, in any part of the cylindrical film 3, two or more thermoplastic film tapes are overlapped, and the rigidity and elasticity (cushioning property) of the cylindrical film 3 can be improved. Note that it is not difficult to take out the optical fiber 2 from the cylindrical film 3 described later.

  In this optical fiber cable 1, in order to take out the optical fiber 2 from the cylindrical film 3 when performing an intermediate post-branching operation, the cylindrical film 3 can be easily opened with a human finger or the like. It can be carried out. Since the cylindrical film 3 is formed into a cylindrical shape, it is easy to store the optical fiber 2 once taken out in the cylindrical film 3 again.

  Moreover, in this optical fiber cable 1, since the optical fiber 2 which comprises the optical unit 2a does not fall in the vicinity of a terminal, handling is easy.

[Configuration of manufacturing equipment]
FIG. 8 is a side view showing a configuration of a manufacturing apparatus that performs the manufacturing method of the optical unit and the manufacturing method of the optical fiber cable in the embodiment according to the present invention.

  In this apparatus, as shown in FIG. 8, a plurality of optical fibers 2 are supplied from an optical fiber supply unit 202. A film tape is supplied from the film tape supply unit 203. The film tape is formed into a cylindrical shape by the forming die and the heating device 214 and is formed into the cylindrical film 3 by being heated. At this time, the cylindrical film 3 can be formed to have an inner diameter smaller than the outer diameter of the plurality of optical fibers 2.

  In the cylindrical film and the fiber assembly portion 215, the plurality of optical fibers 2 are accommodated and integrated in the cylindrical film 3.

  Here, when the UV curable resin is applied around the cylindrical film 3, the UV curable resin supplied from the UV curable resin supply device 211 is used in the UV coating dice unit 212 to store the optical fiber 2. 3 is coated around. The coated ultraviolet curable resin is cured by irradiating ultraviolet rays with a UV lamp 213.

  The cylindrical film 3 and the plurality of optical fibers 2 are sent to a sheath extruder (crosshead) 205 via a gathering portion 204. The slot core 4 may be assembled together with the film tape and the plurality of optical fibers 2.

  The sheath extruder 205 extrudes and coats the sheath 6 around the cylindrical film 3. The optical fiber cable covered with the sheath 6 is fed by the take-up caterpillar 207 and cooled through the water tank 206. The optical fiber cable is wound up by a winder 208.

  For the optical unit described above, as shown in [Table 1] below, as shown in FIG. 8, a method of forming only a film through a forming die (a method of mounting an optical fiber in a cylindrical film after film brazing) ) And a method of forming the film tape by passing the optical fiber and the film tape through a forming die (a method of mounting the optical fiber on the inner side of the film tape before film attachment). That is, trial production was performed by two kinds of methods for assembling the optical fiber and the film tape.

  FIG. 9 is a side view illustrating a configuration of a manufacturing apparatus that performs an optical unit manufacturing method and an optical fiber cable manufacturing method according to a comparative example.

  The optical unit of the comparative example and the optical fiber cable including the optical unit are configured such that the film tape and the plurality of optical fibers 2 are gathered at the film tape and the fiber assembly portion 215 as shown in FIG. Manufactured by the same apparatus. After the assembly with the optical fiber 2, the film tape is heated and brazed by the forming die and the heating device 214.

  In this apparatus, as shown to (a) in FIG. 9, the some optical fiber 2 is supplied from the optical fiber supply part 202. FIG. A film tape is supplied from the film tape supply unit 203. These film tapes and the plurality of optical fibers 2 are stored in the cylindrical film tape and the fiber assembly portion 215 in the cylindrical film tape as shown in FIG. Is done. Then, the film tape is heated by a forming die and heating device 214, is formed into a cylindrical film 3, and is integrated with a plurality of optical fibers 2.

  Here, when the UV curable resin is applied around the cylindrical film 3, the UV curable resin supplied from the UV curable resin supply device 211 is used in the UV coating dice unit 212 to store the optical fiber 2. 3 is coated around. The coated ultraviolet curable resin is cured by irradiating ultraviolet rays with a UV lamp 213.

  The cylindrical film 3 and the plurality of optical fibers 2 are sent to a sheath extruder (crosshead) 205 via a gathering portion 204. The slot core 4 may be assembled together with the film tape and the plurality of optical fibers 2.

  The sheath extruder 205 extrudes and coats the sheath 6 around the cylindrical film 3. The optical fiber cable covered with the sheath 6 is fed by the take-up caterpillar 207 and cooled through the water tank 206. The optical fiber cable is wound up by a winder 208.

  8 and FIG. 9 were used for the trial production of an optical unit using 12 colored optical fibers having an outer diameter of φ250 μm and a film tape made of polyethylene terephthalate (PET) having a width of 5 mm and a thickness of 25 μm.

  In the trial production using the apparatus shown in FIG. 8 and FIG. 9, the forming die was fixed in a heating furnace having a predetermined heating length. The forming die is a cylindrical die having a length of 10 to 30 mm with a hole having a diameter of φ1.0 to 1.4 mm. A taper is attached to the film entrance reconnaissance 1 of the forming die in order to smoothly wind the film up to the size of the hole diameter.

The optical unit manufacturing apparatus shown in FIG. 8 or the optical unit manufacturing apparatus shown in FIG. 9 is used to change the optical unit manufacturing linear speed, heating temperature, and shape of the forming die, and to produce trial conditions and brazing (film forming) Are summarized in the following [Table 1].

  Prototype 1 (comparative example) is a product in which a molding die is passed in order to braze the film tape after assembling the optical fiber and the film tape. Film tape could be brazed at low speed. The outer diameter of the prototyped optical unit was φ1.4 mm, the same as the hole diameter of the molding die. However, when the optical unit coming out of the take-out machine was extended and observed, the mounted optical fiber was observed to jump out. It seems that the tension applied to the entire optical unit was released when it came out of the take-up machine, the film tape stretched by the tension was shrunk, and a line length difference with the optical fiber was generated. In [Table 1], “◯” in the “unit appearance” column indicates that no optical fiber jumps out of the formed film, and “x” indicates that the optical fiber jumps out of the formed film.

  Prototypes 2 to 4 (comparative examples) were produced by increasing the linear velocity from prototype 1. In trial production 2, the linear velocity was increased under the same conditions as in trial production 1, but sufficient heat was not transmitted to the film tape, and the brazing was weak and could not be formed into a cylindrical shape. In trial production 3, it was examined whether brazing can be performed by increasing the heating length. However, the film tape was excessively stretched due to resistance such as friction when passing through the forming die, and the film was broken near the forming die. In [Table 1], “o” in the column “Possible to braze” indicates that brazing is possible, “x” indicates that the brazing is weak and cannot be formed into a cylindrical shape, and “xx” indicates that the film is broken. Under condition 4, the heating length was kept as in trial production 2, and it was examined whether brazing was possible by raising the heating temperature, but breakage due to melting of the film tape occurred. In Prototype 5, it was investigated whether it was possible to strongly braze by narrowing the hole diameter of the forming die. However, the film die was caught by the forming die, and the film tape was disconnected.

  In prototype 6 (Example), the film was brazed into a cylindrical shape and assembled with the fiber. Compared with prototype 1, the film could be smoothly brazed even at a higher speed and with a smaller hole diameter of the forming die. The outer diameter of the perfect optical unit was 1.2 mm, the same as the hole diameter of the molding die, and no optical fiber jumping was observed in the optical unit that came out of the take-out machine.

  In Prototype 7, after the film tape was brazed with a forming die having a hole diameter of φ1.0 mm and the optical fibers were assembled, the outer diameter of the produced optical unit was φ1.1 mm. The diameter of the optical unit could be reduced by narrowing down a plurality of optical fibers with a film tape brazed to a small diameter.

  With only the brazed film tape, there is a risk that the optical fiber will pop out from the mating surface of the film tape when the optical unit is bent, so as described above, apply extrusion resin or UV curable resin to the outer periphery of the film tape and cure You may let them.

  The optical fiber mounted in the film tape may be a plurality of optical fibers or an intermittently fixed tape core wire in which a plurality of optical fibers are intermittently connected.

  FIG. 10 is a side view showing a configuration of a manufacturing apparatus in which a film tape intermediate take-up 221 and a tension adjusting dancer 223 are provided after film tape forming.

  When the molding die having a small hole diameter and the heating device 214 are passed, even when the optical fiber 2 is not passed along with the film tape, resistance such as friction when passing through the molding die and the heating device 214 is increased. May be stretched. When the tension of the film tape when passing through the forming die and the heating device 214 is high, as shown in FIG. 10, the assembly of the film tape intermediate take-up 221 and the optical fiber 2 is provided behind the forming die and the heating device 214. A dancer 223 for adjusting the tension of the film tape at the time may be installed, and the tension of the film tape 3 when integrated with the optical fiber 2 may be adjusted.

  FIG. 11 is a side view showing a configuration of a 60-fiber optical cable manufacturing apparatus in which five 12-fiber optical units are mounted.

  As shown in FIG. 11, 60 optical fiber cables were made by assembling five 12-fiber optical units.

  The optical unit has a 12-core intermittently fixed tape core inside, and a UV curable resin is applied to the outer periphery of the plastic tape to prevent the optical fiber from jumping out of the film tape when the cable is bent or handled. A hardened layer was provided.

  In order to identify a plurality of optical units, the plurality of plastic tapes are printed with different colors. For example, blue, yellow, green, red, and purple are printed, respectively. Different letters and numbers may be printed on the plastic tape.

  When manufacturing tubes having different resin colors on the outer periphery such as a loose tube, for example, five extruders are required to simultaneously manufacture tubes of five colors.

  In FIG. 11, different printed plastic tapes are used, and the outer periphery of the multiple optical units is covered with the same resin. Therefore, only one resin supply system is required, and the cost is low and the space is saved. It can be manufactured.

  When 60 single-fiber optical fibers are mounted, 60 fiber delivery devices are required, but the number of delivery devices 202 can be reduced to 1/12 by using a 12-fiber intermittently fixed tape core. It can be manufactured at low cost and space saving.

  The film tape delivered from the film delivery device 203 is brazed into a cylindrical shape with a heated forming die, and then assembled with the 12-core intermittently fixed tape core wire, and UV resin is applied to the outer periphery of the film tape, and the UV irradiation device 213 And cured. The five optical units thus produced were SZ twisted and housed in a sheath together with the tension member in the cross head 205 to produce an optical fiber cable. This optical fiber cable is fed by a take-up caterpillar 207 and cooled through a water tank 206.

  In this optical fiber cable, every 12 cores are unitized so that discrimination and handling are good, and each optical unit is also reduced in diameter, so that the entire cable can be reduced in diameter.

  The optical fiber cable may have a structure in which only one optical unit is mounted or a structure in which a plurality of optical units are mounted. The number of optical fibers mounted in one optical unit is not limited to 12, but any number of fibers such as 4, 8, 24, 40, 60, 100, 200, etc. I do not care. Moreover, you may mount a 4-core intermittently fixed tape core wire and an 8-core intermittently fixed tape core wire, or may mount a plurality of multi-fiber intermittently fixed tape core wires. Further, as described above, a water absorbing yarn for waterproofing may be disposed inside the optical unit.

  The present invention is applied to an optical unit manufacturing method in which a plurality of optical fibers are combined and an optical fiber cable manufacturing method having a structure in which optical units are assembled.

DESCRIPTION OF SYMBOLS 1 Optical fiber cable 2 Optical fiber 2a Optical unit 3 Cylindrical film 3a Colored part 3b Identification tape 3c Coating 3d Overlapping part 4 Slot core 4a Slot 5 Opening part 6 Sheath

Claims (11)

In the manufacturing method of the optical unit consisting of an optical fiber group composed of a plurality of optical fibers and a cylindrical film that bundles the optical fiber groups,
Forming a cylindrical film by forming a thermoplastic film tape into a cylindrical shape with an overlap in the circumferential direction;
Storing and integrating the optical fiber group in the cylindrical film,
An optical unit manufacturing method, wherein an inner diameter of the cylindrical film when formed into a cylindrical shape is smaller than an outer diameter of the optical fiber group. The method of manufacturing an optical unit according to claim 1, wherein the thermoplastic film tape forming the cylindrical film has a thickness of 0.012 mm to 0.100 mm. The method of manufacturing an optical unit according to claim 1, wherein the cylindrical film is coated with an ultraviolet curable resin on an outer peripheral surface. The cylindrical film has a resin coating on the outer peripheral surface,
3. The optical unit according to claim 1, wherein when the multi-strip optical unit is manufactured, the resin applied to the outer periphery of the multi-strip optical unit is the same, and there is one resin supply system. Manufacturing method. The method for manufacturing an optical unit according to claim 3, wherein the thermoplastic film tape forming the cylindrical tube is made of a colorless and transparent material, and the ultraviolet curable resin is colored. The method for manufacturing an optical unit according to any one of claims 1 to 3, wherein the cylindrical film is partially colored at a predetermined position for identification between the optical units. . The method of manufacturing an optical unit according to any one of claims 1 to 3, wherein the thermoplastic film tape is entirely colored in order to distinguish between the optical units. A tension adjusting device for the film tape at the time of taking the film tape and assembling with the optical fiber is provided behind a forming die for forming the film tape into a cylindrical shape, and behind the film tape, the film tape and the The method for manufacturing an optical unit according to claim 1, wherein the optical fibers are assembled. An optical unit manufactured by the method for manufacturing an optical unit according to any one of claims 1 to 8. In the method of manufacturing an optical fiber cable having a structure in which a plurality of optical units each including a plurality of optical fibers are assembled,
A method of manufacturing an optical fiber cable, wherein a plurality of optical units manufactured by the method of manufacturing an optical unit according to any one of claims 1 to 8 are assembled. An optical fiber cable manufactured by the method for manufacturing an optical fiber cable according to claim 10.

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