Method for manufacturing hybrid cable

Abstract

To provide a hybrid cable capable of suppressing optical loss of a plastic optical fiber.SOLUTION: A hybrid cable 1 includes a sheath 5, a plastic optical fiber 21, and a power supply line 4. The method for manufacturing the hybrid cable 1 includes an assembling step, a coating step, and an annealing step. In the assembling step, the plastic optical fibers 21 and the power supply wires 4 are assembled to obtain the twisted wire cable 10. In the covering step, the stranded cable 10 is covered with a sheath 5 to obtain an unannealed hybrid cable 11. In the annealing step, the unannealed hybrid cable 11 is annealed. The tensile force Gc (g) applied to the optical cable 2 in the assembling step is equal to or less than 900gf. The tension Gc (g) applied to the optical cable 2 and the heating temperature T (°C) in the annealing step satisfy the following formula (1): Gc (g) ≤ -24T (°C.) + 2900 (1) SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a hybrid cable. [Background technology]

[0002] Plastic optical fibers have been known in the art. Plastic optical fibers have, for example, a core and a cladding, and are coated with a coating material. Furthermore, plastic optical fibers are annealed, for example, at a temperature of 50° C. or higher (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-058774 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, hybrid cables have been produced by assembling plastic optical fibers and power lines and covering the assembled cables with a sheath. Annealing hybrid cables has also been considered.

[0005] However, when annealing a hybrid cable, optical loss in the plastic optical fiber may occur depending on the relationship between the manufacturing conditions of the stranded cable and the annealing temperature.

[0006] The present invention provides a method for manufacturing a hybrid cable that can suppress optical loss in a plastic optical fiber. [Means for solving the problem]

[0007] The present invention [1] is a method for manufacturing a hybrid cable, the hybrid cable comprising a sheath, an optical cable disposed inside the sheath, and a power line disposed between the sheath and the optical cable, the optical cable comprising an optical fiber coating material and a plastic optical fiber disposed inside the optical fiber coating material, the manufacturing method comprising: an assembling step of assembling the optical cable and the power line to obtain an assembled cable; a covering step of covering the assembled cable with a sheath to obtain the hybrid cable; and an annealing step of annealing the hybrid cable, wherein in the assembling step, the tension Gc (gf) applied to the optical cable is 900 gf or less, and the tension Gc (gf) applied to the optical cable and the heating temperature T (°C) in the annealing step satisfy the following formula (1).

[0008] Gc(gf)≦-24T(℃)+2900 (1)

[0009] The present invention [2] includes the method for manufacturing a hybrid cable described in the above [1], wherein in the assembling step, the tension Gc (gf) applied to the optical cable is 300 gf or more and 900 gf or less, the heating temperature in the annealing step is 60.0°C or more and 85.0°C or less, and the heating time in the annealing step is 1 hour or more and 24 hours or less.

[0010] The present invention [3] includes a method for manufacturing a hybrid cable according to the above [1] or [2], wherein the heating temperature in the annealing step is 60.0°C or higher and 85.0°C or lower, and the heating time in the annealing step is 12 hours or higher and 24 hours or lower.

[0011] The present invention [4] includes a method for manufacturing a hybrid cable according to any one of the above [1] to [3], wherein the tension Gc (gf) applied to the optical cable and the heating temperature T (°C) in the annealing step satisfy the following formula (2):

[0012] Gc(gf)≦-24T(℃)+2340 (2)

[0013] The present invention [5] includes the method for manufacturing a hybrid cable described in any one of the above [1] to [4], wherein in the assembling process, the tension Gc (gf) applied to the optical cable and / or the tension G (gf) applied to the power line is 50 gf or more.

[0014] The present invention [6] includes the method for manufacturing a hybrid cable according to any one of the above [1] to [5], wherein in the assembling step, the tension Gc (gf) applied to the optical cable is 200 gf or more.

[0015] The present invention [7] includes the method for manufacturing a hybrid cable according to any one of the above [1] to [6], wherein in the assembling step, the tension Gc (gf) applied to the optical cable is 300 gf or more. [Effects of the Invention]

[0016] In the hybrid cable manufacturing method of the present invention, the tension Gc applied to the optical cable in the assembling step is equal to or less than a predetermined value. Also, in the hybrid cable manufacturing method of the present invention, the tension Gc (gf) applied to the optical cable in the assembling step and the heating temperature T (°C) in the annealing step satisfy a predetermined relational expression. Therefore, the hybrid cable manufacturing method of the present invention can suppress optical loss in the plastic optical fiber. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view of a hybrid cable manufactured according to one embodiment of the method for manufacturing a hybrid cable of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing one embodiment of the method for producing a hybrid cable of the present invention. [Figure 3]FIG. 3 is a graph showing the relationship between the tension Gc applied to the optical cable in the assembling step and the heating temperature T in the annealing step. DETAILED DESCRIPTION OF THE INVENTION

[0018] 1. Hybrid Cable In the following, the hybrid cable will be described with reference to FIG.

[0019] (1) Overall structure 1 is a schematic cross-sectional view of a hybrid cable 1 obtained by one embodiment of a method for producing a hybrid cable. The hybrid cable 1 has a substantially circular shape in cross section. The cross section is taken along a direction perpendicular to the longitudinal direction (the same applies hereinafter).

[0020] The hybrid cable 1 includes a sheath 5, an optical cable 2, an electric signal cable 3, and a power line 4. Each of these will be described in detail below.

[0021] (2) Sheath The sheath 5 is the outermost layer of the hybrid cable 1. The sheath 5 has a substantially cylindrical shape. That is, the sheath 5 has a substantially annular shape in a cross-sectional view.

[0022] The sheath 5 is formed from a known material by a known method. Examples of the material for the sheath 5 include resins. Examples of the resin include polyvinyl chloride and polyurethane. These can be used alone or in combination of two or more. Examples of the material for the sheath 5 include polyvinyl chloride and polyurethane, and more preferably polyurethane. In other words, the sheath 5 preferably includes polyvinyl chloride and / or polyurethane, and more preferably includes polyurethane.

[0023] The number of sheaths 5 is, for example, one for one hybrid cable 1. The size of the sheath 5 is not particularly limited and is set appropriately depending on the purpose and application.

[0024] The sheath 5 is disposed on the outermost side of the hybrid cable 1. The sheath 5 covers (in other words, houses) the optical cable 2, the electric signal cable 3, and the power line 4.

[0025] (3) Optical cable The optical cable 2 is an optical transmission component that transmits optical signals in the hybrid cable 1. The optical cable 2 has a substantially cylindrical shape. That is, the optical cable 2 has a substantially circular shape in a cross-sectional view.

[0026] There is no particular limitation on the number of optical cables 2. For example, the number of optical cables 2 is one for one hybrid cable 1.

[0027] The optical cable 2 includes an optical fiber coating material 22 and a plastic optical fiber 21 disposed inside the optical fiber coating material 22. In other words, the hybrid cable 1 includes the optical fiber coating material 22 and the plastic optical fiber 21.

[0028] [Optical fiber coating material] The optical fiber coating material 22 is the outermost layer of the optical cable 2. The optical fiber coating material 22 has a substantially cylindrical shape. That is, the optical fiber coating material 22 has a substantially annular shape in a cross-sectional view.

[0029] The optical fiber coating material 22 is formed from known materials by known methods. Examples of materials for the optical fiber coating material 22 include resins. Examples of resins include acrylic resins, epoxy resins, polyimide resins, polyvinyl chloride resins (PVC), and ionomer resins. These can be used alone or in combination of two or more. A preferred material for the optical fiber coating material 22 is ionomer resin.

[0030] The ionomer resin is not particularly limited, but examples thereof include ethylene-based ionomers and styrene-based ionomers, with ethylene-based ionomers being preferred. The ethylene-based ionomer contains, for example, polyethylene and a metal ion. Examples of the metal include sodium, magnesium, and zinc, with magnesium being preferred. A particularly preferred ionomer resin is an ethylene-based ionomer containing polyethylene and magnesium hydroxide. In other words, the optical fiber coating material 22 preferably contains polyethylene and magnesium hydroxide.

[0031] The number of optical fiber coating materials 22 is, for example, one for one optical cable 2. The size of the optical fiber coating material 22 is not particularly limited and is set appropriately depending on the purpose and application.

[0032] The optical fiber coating material 22 is disposed on the outermost side of the optical cable 2. The optical fiber coating material 22 is disposed inside the sheath 5 (in other words, inside the tube). In other words, the optical fiber coating material 22 is disposed between the sheath 5 and the plastic optical fiber 21. The optical fiber coating material 22 coats the plastic optical fiber 21.

[0033] [Plastic optical fiber] The plastic optical fiber 21 transmits an optical signal in the optical cable 2. The plastic optical fiber 21 has a substantially cylindrical shape. That is, the plastic optical fiber 21 has a substantially circular shape in a cross-sectional view.

[0034] The plastic optical fiber 21 includes, for example, a core (not shown), a clad (not shown), and an overclad (not shown) in this order radially outward. The plastic optical fiber 21 is flexible.

[0035] The plastic optical fiber 21 is formed from a known material by a known method. Examples of the material for the plastic optical fiber 21 include resin. Examples of the resin include acrylic resin and epoxy resin. These can be used alone or in combination of two or more types.

[0036] The number of plastic optical fibers 21 is not particularly limited. For example, the number of plastic optical fibers 21 is plural. More specifically, the number of plastic optical fibers 21 per optical cable 2 is, for example, 2 to 20, preferably 2 to 8, more preferably 2 to 4, and particularly preferably 4.

[0037] The thickness (here, this means the outer diameter) of the plastic optical fiber 21 is not particularly limited. The thickness (here, this means the outer diameter) of the plastic optical fiber 21 is, for example, 0.05 mm or more, preferably 0.15 mm or more. The thickness (here, this means the outer diameter) of the plastic optical fiber 21 is, for example, 0.50 mm or less, preferably 0.35 mm or less. In other words, the thickness (here, this means the outer diameter) of the plastic optical fiber 21 is, for example, 0.05 mm or more and 0.50 mm or less, preferably 0.15 mm or more and 0.35 mm or less.

[0038] The plastic optical fiber 21 is disposed inside the hybrid cable 1. In other words, the plastic optical fiber 21 is disposed inside the sheath 5 (in other words, inside the tube).

[0039] The plastic optical fiber 21 is disposed inside the optical fiber coating material 22 (in other words, inside the tube). Preferably, all of the multiple plastic optical fibers 21 are disposed inside one optical fiber coating material 22. In other words, all of the plastic optical fibers 21 are collectively coated by one optical fiber coating material 22. Although not shown, a tensile strength fiber may be disposed between the plastic optical fiber 21 and the optical fiber coating material 22. Examples of materials for the tensile strength fiber include aramid fiber and cotton (thread).

[0040] [Optical cable placement] The optical cable 2 is manufactured by a known method and is disposed inside the hybrid cable 1. More specifically, the optical cable 2 is disposed inside the sheath 5 (in other words, inside a tube). The optical cable 2 is also disposed between the sheath 5 and the electrical signal cable 3. In other words, the optical cable 2 and the electrical signal cable 3 are disposed side by side inside the sheath 5.

[0041] The thickness (here, this means the outer diameter) of the optical cable 2 is not particularly limited. For example, the thickness (here, this means the outer diameter) of the optical cable 2 is, for example, 5.0 mm or more, preferably 5.2 mm or more, and more preferably 5.5 mm or more. The thickness (here, this means the outer diameter) of the optical cable 2 is, for example, 7.0 mm or less, preferably 6.5 mm or less, and more preferably 6.0 mm or less. In other words, the thickness (here, this means the outer diameter) of the optical cable 2 is, for example, 5.00 mm or more and 7.0 mm or less, preferably 5.20 mm or more and 6.5 mm or less, and more preferably 5.50 mm or more and 6.0 mm or less.

[0042] (4) Electrical signal cable The electric signal cable 3 is an electric signal transmission component that transmits electric signals in the hybrid cable 1. The electric signal cable 3 has a substantially cylindrical or elliptical cylindrical shape. That is, the electric signal cable 3 has a substantially circular or elliptical shape in a cross-sectional view.

[0043] There is no particular limitation on the number of electric signal cables 3. For example, the number of electric signal cables 3 is one for one hybrid cable 1.

[0044] The electric signal cable 3 includes, for example, a shielding member 32 and a pair of differential wirings 31 covered by the shielding member 32.

[0045] [Shielded cord] The shielding member 32 is the outermost layer of the electric signal cable 3. The shielding member 32 is an insulating member that bundles the pair of differential wiring lines 31. The shielding member 32 has a substantially cylindrical shape or a substantially elliptical cylindrical shape. That is, the shielding member 32 has a substantially circular ring shape or a substantially elliptical ring shape in a cross-sectional view.

[0046] The shielding member 32 is formed from known materials by known methods. Examples of materials for the shielding member 32 include resins and foams thereof. Examples of resins include polyester resins, polyolefin resins, polyimide resins, and rubber. These can be used alone or in combination of two or more types.

[0047] There is no particular limitation on the number of shielding members 32. For example, there is one shielding member 32 for one electric signal cable 3. There is no particular limitation on the thickness of the shielding member 32, and it is set appropriately depending on the purpose and application.

[0048] The shielding member 32 is disposed on the outermost side of the electric signal cable 3. The shielding member 32 is disposed inside the sheath 5 (in other words, inside the tube). In other words, the shielding member 32 is disposed between the sheath 5 and the pair of differential wiring lines 31. The shielding member 32 covers (in other words, houses) the pair of differential wiring lines 31.

[0049] [Differential wiring] The pair of differential wiring lines 31 transmits an electric signal in the electric signal cable 3. More specifically, the pair of differential wiring lines 31 includes a first wiring line 31A and a second wiring line 31B. The first wiring line 31A and the second wiring line 31B have the same configuration. Each of the pair of differential wiring lines 31 has a substantially cylindrical shape. That is, each of the pair of differential wiring lines 31 has a substantially circular shape in a cross-sectional view.

[0050] The pair of differential wiring lines 31 is formed of known materials by known methods. More specifically, each of the pair of differential wiring lines 31 includes a core wire 310 and a coating material 311 that covers the core wire 310, arranged in this order from the inside to the outside in the radial direction. Examples of materials for the core wire 310 include known metals. Examples of materials for the coating material 311 include the above-mentioned resins. These materials can be used alone or in combination of two or more types.

[0051] There is no particular limitation on the number of pairs of differential wiring 31. The number of pairs of differential wiring 31 is, for example, one for one electric signal cable 3. That is, the number of first wirings 31A is, for example, one for one electric signal cable 3. Furthermore, the number of second wirings 31B is, for example, one for one electric signal cable 3.

[0052] The thickness (here, this means the outer diameter) of the first wiring 31A and the thickness (here, this means the outer diameter) of the second wiring 31B are not particularly limited and are set appropriately depending on the purpose and application.

[0053] The pair of differential wires 31 is arranged inside the hybrid cable 1. That is, the pair of differential wires 31 is arranged inside the sheath 5 (in other words, inside the tube).

[0054] Moreover, the pair of differential wiring lines 31 is arranged inside the shielding member 32 (in other words, inside the cylinder). Preferably, each of the pair of differential wiring lines 31 is arranged inside one shielding member 32. In other words, the pair of differential wiring lines 31 is collectively covered by one shielding member 32.

[0055] [Layout of electrical signal cables] The electric signal cable 3 is manufactured by a known method and disposed inside the hybrid cable 1. More specifically, the electric signal cable 3 is disposed inside the sheath 5 (in other words, inside the tube). The electric signal cable 3 is also disposed outside the optical fiber coating material 22. That is, the electric signal cable 3 is disposed between the sheath 5 and the optical fiber coating material 22. In other words, the optical cable 2 and the electric signal cable 3 are disposed side by side inside the sheath 5.

[0056] The thickness (here, this means the outer diameter) of the electric signal cable 3 is not particularly limited and is set appropriately depending on the purpose and application.

[0057] (5) Power line The power line 4 is a cable for supplying power and includes, for example, a power feed line 41. The power line 4 also includes a ground line 42 as necessary.

[0058] [Feeder line] The power supply line 41 has a substantially cylindrical shape. That is, the power supply line 41 has a substantially circular shape in a cross-sectional view.

[0059] The power feeder 41 is formed from known materials by known methods. Examples of materials for the power feeder 41 include metals. Examples of metals include tin, copper, iron, silver, gold, aluminum, nickel, and alloys thereof. Examples of alloys include stainless steel and bronze. These can be used alone or in combination. If necessary, the power feeder 41 can be provided with a power feeder cover (not shown) that covers the metal.

[0060] The number of power feed lines 41 is not particularly limited. For example, there is one power feed line 41 for one power line 4. The outer diameter of the power feed line 41 is not particularly limited and may be set appropriately depending on the purpose and application.

[0061] [Ground wire] The ground line 42 has a substantially cylindrical shape. That is, the ground line 42 has a substantially circular shape in cross section.

[0062] The ground line 42 is formed of a known material by a known method, such as the above-mentioned metals. If necessary, the ground line 42 may be provided with a ground line cover (not shown) that covers the above-mentioned metals.

[0063] There is no particular limit to the number of ground wires 42. For example, there is one ground wire 42 for one power line 4. There is no particular limit to the thickness (here, this means the outer diameter) of the ground wire 42, and it is set appropriately depending on the purpose and application.

[0064] [Power line placement] The power line 4 is manufactured by a known method and is arranged inside the hybrid cable 1. More specifically, the power feed line 41 and the ground line 42 are arranged adjacent to each other. The power feed line 41 and the ground line 42 are arranged inside the hybrid cable 1. In other words, the power line 4 is arranged inside the sheath 5 (in other words, inside the tube).

[0065] Furthermore, the power line 4 (the power feed line 41 and the ground line 42) is disposed outside the optical fiber coating material 22. That is, the power line 4 (the power feed line 41 and the ground line 42) is disposed between the sheath 5 and the optical fiber coating material 22.

[0066] Furthermore, the power line 4 (the power feed line 41 and the ground line 42) is disposed outside the shielding member 32. That is, the power line 4 (the power feed line 41 and the ground line 42) is disposed between the sheath 5 and the shielding member 32.

[0067] In other words, the optical cable 2, the electric signal cable 3, and the power line 4 (the power feed line 41 and the ground line 42) are arranged side by side inside the sheath 5.

[0068] 2. Hybrid cable manufacturing method A method for manufacturing the hybrid cable 1 will be described below with reference to FIG.

[0069] (1) Assembling process In this method, first, an optical cable 2, an electric signal cable 3, and a power line 4 are prepared. Next, as shown in area α of Fig. 2, the optical cable 2, the electric signal cable 3, and the power line 4 (i.e., the power feed line 41 and the ground line 42) are assembled to obtain a stranded cable 10 as an assembled wire.

[0070] More specifically, as shown by the arrows in FIG. 2, in the assembling step, the optical cable 2, the electric signal cable 3, and the power line 4 are transported in a predetermined direction while being pulled with a predetermined tension G.

[0071] In the assembling step, the tension applied to the optical cable 2 is set from the viewpoint of suppressing optical loss in the optical cable 2.

[0072] For example, from the viewpoint of suppressing optical loss, the tension applied to the optical cable 2 is, for example, greater than 0 gf, preferably 50 gf or more, more preferably 100 gf or more, even more preferably 200 gf or more, and particularly preferably 300 gf or more. Also, from the viewpoint of suppressing optical loss, the tension (gf) applied to the optical cable 2 is 900 gf or less, preferably 800 gf or less, more preferably 700 gf or less, and even more preferably 600 gf or less. That is, from the viewpoint of suppressing optical loss, the tension (gf) applied to the optical cable 2 is, for example, greater than 0 gf and less than 900 gf, preferably 50 gf or more and less than 900 gf, more preferably 100 gf or more and less than 900 gf, even more preferably 200 gf or more and less than 900 gf, even more preferably 300 gf or more and less than 900 gf, even more preferably 300 gf or more and less than 800 gf, even more preferably 300 gf or more and less than 700 gf, and particularly preferably 300 gf or more and less than 600 gf.

[0073] Furthermore, the tension applied to the plastic optical fiber 21 is smaller than the tension applied to the optical cable 2. For example, the tension applied to the plastic optical fiber 21 is, for example, half or less, preferably one-fifth or less, and more preferably one-tenth or less of the tension applied to the optical cable 2.

[0074] More specifically, from the viewpoint of suppressing optical loss, the tension (gf) applied to the plastic optical fiber 21 is, for example, greater than 0 gf, preferably 5 gf or greater, more preferably 7 gf or greater, even more preferably 10 gf or greater, and particularly preferably 15 gf or greater. Furthermore, from the viewpoint of suppressing optical loss, the tension (gf) applied to the plastic optical fiber 21 is, for example, 100 gf or less, preferably 70 gf or less, more preferably 50 gf or less, even more preferably 30 gf or less, and particularly preferably 20 gf or less. That is, from the viewpoint of suppressing optical loss, the tension (gf) applied to the plastic optical fiber 21 is, for example, greater than 0 and 100 gf or less, preferably 5 gf or greater and 70 gf or less, more preferably 7 gf or greater and 50 gf or less, even more preferably 10 gf or greater and 30 gf or less, and even more preferably 15 gf or greater and 20 gf or less.

[0075] The tension applied to the electric signal cable 3 is set from the viewpoint of production efficiency of the stranded cable 10.

[0076] For example, from the viewpoint of production efficiency, the tension (gf) applied to the electric signal cable 3 is, for example, 50 gf or more, preferably 100 gf or more, more preferably 200 gf or more, and even more preferably 300 gf or more. Furthermore, the tension (gf) applied to the electric signal cable 3 is, for example, 900 gf or less, preferably 800 gf or less, more preferably 700 gf or less, and even more preferably 600 gf or less. That is, from the viewpoint of production efficiency, the tension (gf) applied to the electric signal cable 3 is, for example, 50 gf to 900 gf, preferably 100 gf to 800 gf, more preferably 200 gf to 700 gf, and even more preferably 300 gf to 600 gf.

[0077] Moreover, the tension (gf) applied to the differential wiring 31 is the same as the tension applied to the electric signal cable 3.

[0078] That is, from the viewpoint of production efficiency, the tension (gf) applied to the differential wiring 31 is, for example, 50 gf or more, preferably 100 gf or more, more preferably 200 gf or more, and even more preferably 300 gf or more. Also, from the viewpoint of production efficiency, the tension (gf) applied to the differential wiring 31 is, for example, 900 gf or less, preferably 800 gf or less, more preferably 700 gf or less, and even more preferably 600 gf or less. That is, from the viewpoint of production efficiency, the tension (gf) applied to the differential wiring 31 is, for example, 50 gf or more and 900 gf or less, preferably 100 gf or more and 800 gf or less, more preferably 200 gf or more and 700 gf or less, and even more preferably 300 gf or more and 600 gf or less.

[0079] The tension applied to the power wire 4 is set from the viewpoint of production efficiency of the stranded cable 10.

[0080] For example, from the viewpoint of production efficiency, the tension (gf) applied to the power line 4 is, for example, 50 gf or more, preferably 100 gf or more, more preferably 200 gf or more, and even more preferably 300 gf or more. Also, from the viewpoint of production efficiency, the tension (gf) applied to the power line 4 is, for example, 900 gf or less, preferably 800 gf or less, more preferably 700 gf or less, and even more preferably 600 gf or less. That is, from the viewpoint of production efficiency, the tension (gf) applied to the power line 4 is, for example, 50 gf or more and 900 gf or less, preferably 100 gf or more and 800 gf or less, more preferably 200 gf or more and 700 gf or less, and even more preferably 300 gf or more and 600 gf or less.

[0081] The tension (gf) applied to the power supply line 41 and the ground line 42 is the same as the tension applied to the power line 4.

[0082] That is, from the viewpoint of production efficiency, the tension (gf) applied to the power feed line 41 and the ground line 42 is, for example, 50 gf or more, preferably 100 gf or more, more preferably 200 gf or more, and even more preferably 300 gf or more. Also, from the viewpoint of production efficiency, the tension (gf) applied to the power feed line 41 and the ground line 42 is, for example, 900 gf or less, preferably 800 gf or less, more preferably 700 gf or less, and even more preferably 600 gf or less. That is, from the viewpoint of production efficiency, the tension (gf) applied to the power feed line 41 and the ground line 42 is, for example, 50 gf to 900 gf, preferably 100 gf to 800 gf, more preferably 200 gf to 700 gf, and even more preferably 300 gf to 600 gf.

[0083] In addition, in the assembling process, the conveying speed of the optical cable 2, the electric signal cable 3, and the power line 4 is, for example, 1.0 m / min or more and 5.0 m / min or less, preferably 2.0 m / min or more and 4.0 m / min or less, and more preferably 2.5 m / min or more and 3.5 m / min or less.

[0084] Then, in the assembling process, the optical cable 2, the electric signal cable 3, and the power line 4 are twisted in a direction perpendicular to the conveying direction while being conveyed. As a result, the bundle of the optical cable 2, the electric signal cable 3, and the power line 4 forms a helical wire (spiral wire). In other words, a stranded cable 10 is formed as an assembled wire including the optical cable 2, the electric signal cable 3, and the power line 4. The twist pitch of the stranded cable 10 is set appropriately depending on the purpose and application.

[0085] (2) Coating process Next, in this method, as shown in region β in FIG. 2, the stranded cable 10 is covered with a sheath 5 to obtain a hybrid cable 1 (covering step).

[0086] More specifically, in this process, as shown by the arrow in Figure 2, the stranded cable 10 is transported in a predetermined direction, and a sheath 5 is formed to surround the stranded cable 10, thereby covering the stranded cable 10 with the sheath 5.

[0087] There are no particular limitations on the method for covering the stranded cable 10 with the sheath 5. For example, an extrusion molding method may be used. In this method, for example, the stranded cable 10 is conveyed in a predetermined direction and passed through a known extruder 101, and the sheath 5 is extruded around the stranded cable 10 in the extruder 101.

[0088] In the covering step, the conveying speed of the stranded cable 10 is, for example, 5 m / min to 30 m / min, preferably 10 m / min to 25 m / min, and more preferably 15 m / min to 20 m / min.

[0089] In the covering step, the tension applied to the stranded cable 10 when the stranded cable 10 is transported is not particularly limited, and is selected depending on the purpose and application.

[0090] As a result, the stranded cable 10 is covered with the sheath 5, and the hybrid cable 1 is obtained.

[0091] (3) Annealing process Next, in this method, the hybrid cable 1 obtained in the above covering step is annealed (annealing step).

[0092] More specifically, in the assembling step, the optical cable 2, the electric signal cable 3, and the power line 4 may be pulled and deformed. Also, in the covering step, the stranded cable 10 including the optical cable 2, the electric signal cable 3, and the power line 4 may be pulled and deformed.

[0093] Therefore, in order to eliminate the above-mentioned deformation, in this method, as shown by the arrow in Figure 2, referring to region γ in Figure 2, a hybrid cable 1 including an optical cable 2, an electric signal cable 3, and a power line 4 is transported along a predetermined direction and heated under predetermined conditions to anneal the hybrid cable 1.

[0094] In the following description, the hybrid cable 1 before being annealed will be referred to as a pre-annealed hybrid cable 11. The hybrid cable 1 after being annealed will be referred to as a post-annealed hybrid cable 12.

[0095] The method for annealing the pre-annealed hybrid cable 11 is not particularly limited. For example, the pre-annealed hybrid cable 11 is transported in a predetermined direction, passed through a known heating device 102, and heated in the heating device 102. In other words, the pre-annealed hybrid cable 11 can be annealed online. Although not described in detail, the pre-annealed hybrid cable 11 can also be removed from the above process and annealed without being transported in a predetermined direction. In other words, the pre-annealed hybrid cable 11 can be annealed offline.

[0096] When the pre-annealed hybrid cable 11 is annealed online, the conveying speed of the pre-annealed hybrid cable 11 in the annealing step is, for example, 0.1 m / min to 2.0 m / min, preferably 0.3 m / min to 1.5 m / min, and more preferably 0.5 m / min to 1.0 m / min. Note that when the pre-annealed hybrid cable 11 is annealed online, the pre-annealed hybrid cable 11 is not conveyed, for example.

[0097] The heating temperature T (° C.) in the annealing step is set in accordance with the tension Gc (gf) applied to the optical cable 2 in the assembling step, from the viewpoint of suppressing optical loss.

[0098] More specifically, in this method, the tension Gc (gf) applied to the optical cable 2 in the assembling step and the heating temperature T (° C.) in the annealing step satisfy the following formula (1).

[0099] Gc(gf)≦-24T(℃)+2900 (1)

[0100] In FIG. 3, the graph of Gc(gf)=-24T(°C)+2900 is shown by the solid line.

[0101] 3, when the tension Gc applied to the optical cable 2 in the assembling process is 900 gf, the heating temperature T in the annealing process is, for example, 83.3°C or less. When the tension Gc applied to the optical cable 2 in the assembling process is 600 gf, the heating temperature T in the annealing process is, for example, 95.8°C or less. When the tension Gc applied to the optical cable 2 in the assembling process is 300 gf, the heating temperature T in the annealing process is, for example, 108.3°C or less.

[0102] In this method, preferably, the tension Gc (gf) applied to the optical cable 2 in the assembling step and the heating temperature T (° C.) in the annealing step satisfy the following formula (2).

[0103] Gc(gf)≦-24T(℃)+2340 (2)

[0104] In FIG. 3, the graph of Gc(gf)=-24T(°C)+2340 is shown by the dashed line.

[0105] More specifically, as shown by the dashed line graph in Fig. 3, when the tension Gc applied to the optical cable 2 in the assembling step is 900 gf, the heating temperature T in the annealing step is preferably 60.0°C or less. Furthermore, when the tension Gc applied to the optical cable 2 in the assembling step is 600 gf, for example, the heating temperature T in the annealing step is preferably 72.5°C or less. Furthermore, when the tension Gc applied to the optical cable 2 in the assembling step is 300 gf, for example, the heating temperature T in the annealing step is preferably 85.0°C or less.

[0106] As described above, the upper limit of the heating temperature T (° C.) in the annealing step is set according to the tension Gc (gf) applied to the optical cable 2 in the assembling step.

[0107] In this method, the lower limit of the heating temperature T (° C.) in the annealing step is also preferably set in accordance with the tension Gc (gf) applied to the optical cable 2 in the assembling step.

[0108] More specifically, for example, the tension Gc (gf) applied to the optical cable 2 in the assembling step and the heating temperature T (° C.) in the annealing step satisfy the following formula (3).

[0109] Gc(gf)≧ -24T(℃)+1500 (3)

[0110] In FIG. 3, the graph of Gc(gf)=-24T(°C)+1500 is shown by the dotted line.

[0111] 3, when the tension Gc applied to the optical cable 2 in the assembling process is 900 gf, the heating temperature T in the annealing process is, for example, 25.0°C or higher. When the tension Gc applied to the optical cable 2 in the assembling process is 600 gf, the heating temperature T in the annealing process is, for example, 37.5°C or higher. When the tension Gc applied to the optical cable 2 in the assembling process is 300 gf, the heating temperature T in the annealing process is, for example, 50.0°C or higher.

[0112] In this method, preferably, the tension Gc (gf) applied to the optical cable 2 in the assembling step and the heating temperature T (° C.) in the annealing step satisfy the following formula (4).

[0113] Gc(gf)≧ -24T(℃)+1740 (4)

[0114] In FIG. 3, the graph of Gc(gf)=-24T(°C)+1740 is shown by the dashed dotted line.

[0115] More specifically, as shown in the dashed-dotted line graph in Fig. 3, when the tension Gc applied to the optical cable 2 in the assembling step is 900 gf, the heating temperature T in the annealing step is preferably 35.0°C or higher. Furthermore, when the tension Gc applied to the optical cable 2 in the assembling step is 600 gf, the heating temperature T in the annealing step is preferably 47.5°C or higher. Furthermore, when the tension Gc applied to the optical cable 2 in the assembling step is 300 gf, the heating temperature T in the annealing step is preferably 60.0°C or higher.

[0116] The tension Gc applied to the optical cable in the assembling step is not limited to the above. As described above, the tension Gc applied to the optical cable in the assembling step is preferably 300 gf or more and 900 gf or less, and particularly preferably 300 gf or more and 600 gf or less.

[0117] When the tension Gc applied to the optical cable in the assembling step is 300 gf or more and 900 gf or less, from the viewpoint of suppressing optical loss, the heating temperature T in the annealing step is, for example, 25.0° C. or more, preferably 35.0° C. or more, more preferably 37.5° C. or more, even more preferably 47.5° C. or more, even more preferably 50.0° C. or more, and particularly preferably 60.0° C. or more. When the tension Gc applied to the optical cable in the assembling step is 300 gf or more and 900 gf or less, from the viewpoint of suppressing optical loss, the heating temperature T in the annealing step is, for example, 108.3° C. or less, preferably 95.8° C. or less, more preferably 85.0° C. or less.

[0118] That is, when the tension Gc applied to the optical cable in the assembling process is 300 gf or more and 900 gf or less, from the viewpoint of suppressing optical loss, the heating temperature T in the annealing process is, for example, 25.0°C or more and 108.3°C or less, preferably 35.0°C or more and 95.8°C or less, more preferably 37.5°C or more and 85.0°C or less, even more preferably 47.5°C or more and 85.0°C or less, still more preferably 50.0°C or more and 85.0°C or less, and particularly preferably 60.0°C or more and 85.0°C or less.

[0119] More specifically, when the tension Gc applied to the optical cable in the assembling step is 900 gf, the heating temperature T in the annealing step is, for example, 25.0°C or higher and 83.3°C or lower, preferably 35.0°C or higher and 60.0°C or lower.

[0120] Furthermore, when the tension Gc applied to the optical cable in the assembling step is 600 gf, the heating temperature T in the annealing step is, for example, 37.5°C or more and 95.8°C or less, preferably 47.5°C or more and 72.5°C or less.

[0121] Furthermore, when the tension Gc applied to the optical cable in the assembling step is 300 gf, the heating temperature T in the annealing step is, for example, 50.0°C or higher and 108.3°C or lower, preferably 60.0°C or higher and 85.0°C or lower.

[0122] Furthermore, when the heating temperature T in the annealing step is within the above range, from the viewpoint of suppressing light loss, the heating time t in the annealing step is, for example, 1 minute or more, preferably 1 hour or more, more preferably 6 hours or more, and even more preferably 12 hours or more. From the viewpoint of suppressing light loss, the heating time t in the annealing step is, for example, 42 hours or less, preferably 24 hours or less. That is, from the viewpoint of suppressing light loss, the heating time t in the annealing step is, for example, 1 minute or more and 42 hours or less, preferably 1 hour or more and 24 hours or less, more preferably 6 hours or more and 24 hours or less, and even more preferably 12 hours or more and 24 hours or less.

[0123] By the above-mentioned annealing treatment, the pre-annealed hybrid cable 11 is annealed to obtain the annealed hybrid cable 12. Although not shown, the annealed hybrid cable 12 is wound up by a known method.

[0124] 3. Effects According to the above method, the hybrid cable 1 can be manufactured with high production efficiency. That is, in the assembling process, the optical cable 2, the electric signal cable 3, and the power cable 4 are transported in a predetermined direction while being pulled with a predetermined tension G. According to such a method, the stranded cable 10 (i.e., an assembled wire) can be obtained efficiently. As a result, the hybrid cable 1 can be manufactured with high production efficiency.

[0125] On the other hand, when the hybrid cable 1 is manufactured by the above method, optical loss in the plastic optical fiber 21 may occur.

[0126] More specifically, in the above method, the optical cable 2 is pulled, and if the tension Gc applied to the optical cable 2 exceeds a predetermined value, optical loss in the plastic optical fiber 21 may occur.

[0127] Furthermore, even if the tension Gc applied to the optical cable 2 is less than a predetermined value, depending on the annealing temperature of the hybrid cable 1, optical loss in the plastic optical fiber 21 may occur.

[0128] In contrast, in the above-described method for manufacturing the hybrid cable 1, the tension Gc applied to the optical cables 2 in the assembling step is equal to or less than a predetermined value.

[0129] Furthermore, in the above-described method for manufacturing the hybrid cable 1, the tension Gc(g) applied to the optical cables 2 in the assembling step and the heating temperature T(°C) in the annealing step satisfy a predetermined relational expression. More specifically, the tension Gc(g) and the heating temperature T(°C) satisfy the above-described expression (1).

[0130] Therefore, according to the above-described method for manufacturing the hybrid cable 1, the optical loss of the plastic optical fiber 21 can be suppressed.

[0131] In particular, if the tension Gc (g) applied to the optical cable 2 and the heating temperature T (° C.) in the annealing step satisfy the above formula (2), the optical loss of the plastic optical fiber 21 can be further suppressed.

[0132] 4. Variations In the above-mentioned method for manufacturing the hybrid cable 1, the heating temperature T in the annealing step is set according to the tension Gc applied to the optical cable in the assembling step, based on the above-mentioned formulas (1) to (4). On the other hand, in the method for manufacturing the hybrid cable 1, the tension Gc applied to the optical cable in the assembling step may be set according to the heating temperature T in the annealing step, based on the above-mentioned formulas (1) to (4).

[0133] Furthermore, in the manufacturing method of the hybrid cable 1 described above, the number of each component (e.g., optical cable 2, plastic optical fiber 21, optical fiber coating material 22, electrical signal cable 3, differential wiring 31, shielding member 32, power line 4, power feed line 41, ground line 42, and control line) is arbitrary.

[0134] Furthermore, in the above-described method for manufacturing hybrid cable 1, optical cables 2, electric signal cables 3, and power lines 4 are assembled together to obtain stranded cable 10 as an assembly wire, but the assembly wire does not have to be stranded cable 10. In other words, optical cables 2, electric signal cables 3, and power lines 4 may be assembled without being twisted. In other words, the assembly wire may be a bundle of straight cables.

[0135] Furthermore, although the hybrid cable 1 described above includes the electric signal cable 3, the hybrid cable 1 does not necessarily have to include the electric signal cable 3, for example.

[0136] The hybrid cable 1 may also include other cables, although these are not shown. These other cables are cables other than the optical cable 2, the electrical signal cable 3, and the power line 4. The type and number of these other cables are not particularly limited and are selected appropriately depending on the purpose and application. Although not shown, the other cables may, for example, form a stranded cable 10 together with the optical cable 2, the electrical signal cable 3, and the power line 4, and be covered with a sheath 5.

[0137] The hybrid cable 1 may also include tensile strength fibers, although this is not shown. The type and number of tensile strength fibers are not particularly limited and are selected appropriately depending on the purpose and application. Although not shown, the tensile strength fibers, for example, together with the optical cable 2, the electric signal cable 3, and the power line 4, form a stranded cable 10, which is covered with a sheath 5. Examples of materials for the tensile strength fibers include aramid fibers and cotton (thread). [Example]

[0138] Examples and comparative examples are shown below to explain the present invention more specifically. Note that the present invention is not limited to any examples and comparative examples. In addition, specific numerical values such as the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values (numerical values defined as "below" and "less than") or lower limit values (numerical values defined as "above" and "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Mode for Carrying Out the Invention".

[0139] <A: Tension 900 gf, 22 tensile strength fibers> Example A1 (70°C for 12 hours) (1) Assembly process One optical cable including four plastic optical fibers, one electrical signal cable composed of differential wiring, one power line including a power supply line and a ground line, and 22 tensile strength fibers were assembled while twisting to obtain a twisted cable as an assembled wire.

[0140] In the assembly process, the tension applied to the optical cable was 900 gf. Also, the tension applied to the electrical signal cable was 700 gf. Also, the tension applied to the power line was 800 gf. <00004~75> (2) Coating process<000"0477>A sheath was extruded around the twisted cable obtained in the assembly process to obtain a pre-annealed hybrid cable.

[0142] [[ID=2"3]] " (Z) Annealing process The pre-annealed hybrid cable obtained in the coating process was annealed to obtain a post-annealed hybrid cable. The annealing temperature was set at 70°C. Also, the annealing time was set at 12 hours.

[0143] (4) Evaluation The optical loss coefficient of each plastic optical fiber in the pre-annealed hybrid cable was measured using an OTDR measuring device.

[0144] In addition, the optical loss coefficient of each plastic optical fiber in the annealed hybrid cable was measured using an OTDR measuring device.

[0145] The OTDR measuring device is described in detail below. Product name: LOR-220, manufactured by Luciol Instruments Sample length: 10m Light wavelength: 850nm

[0146] Then, the optical loss coefficient per 5 m (dB / 5 m) of each plastic optical fiber was calculated, and the amount of change in the optical loss coefficient before and after annealing was calculated according to the following formula.

[0147] Change in optical loss coefficient (dB / 5m) = Optical loss coefficient of the plastic optical fiber in the hybrid cable after annealing (dB / 5m) - Optical loss coefficient of the plastic optical fiber in the hybrid cable before annealing (dB / 5m)

[0148] The average change in optical loss coefficient was calculated for the four plastic optical fibers, and the average change in optical loss coefficient was 0.60 (dB / 5m) or less.

[0149] Example A2 (70°C for 24 hours) An annealed hybrid cable was obtained in the same manner as in Example A1, except that the annealing time was changed to 24 hours. The tension applied to the optical cable was 900 gf. The annealed hybrid cable was evaluated in the same manner as in Example A1.

[0150] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.70 (dB / 5m).

[0151] Comparative Example A1 (85°C for 12 hours) A hybrid cable after annealing was obtained in the same manner as in Example A1, except that the annealing temperature was changed to 85°C. The tension applied to the optical cable was 900 gf. Also, the hybrid cable after annealing was evaluated in the same manner as in Example A1.

[0152] Then, in four plastic optical fibers, the average value of the change amount of the optical loss coefficient was calculated. The average value of the change amount of the optical loss coefficient was 3.40 (dB / 5 m).

[0153] Comparative Example A2 (85°C for 24 hours) A hybrid cable after annealing was obtained in the same manner as in Example A1, except that the annealing temperature was changed to 85°C and the annealing time was changed to 24 hours. The tension applied to the optical cable was 900 gf. Also, the hybrid cable after annealing was evaluated in the same manner as in Example A1.

[0154] Then, in four plastic optical fibers, the average value of the change amount of the optical loss coefficient was calculated. The average value of the change amount of the optical loss coefficient was 3.29 (dB / 5 m).

[0155] <B: Tension 300 gf, 3 tensile strength fibers> Example B1 (70°C for 12 hours) [[ID=2,1]] One optical cable including four plastic optical fibers, one electrical signal cable composed of differential wiring, one power supply line including a power supply line and a ground line, and three tensile strength fibers were assembled while being twisted to obtain a stranded cable as an assembled wire.

[0156] In the assembling process, the tension applied to the optical cable was 300 gf.

[0157] (2) Coating process A sheath was extruded around the stranded cable obtained in the assembling process to obtain a pre-annealing hybrid cable.

[0158] (3) Annealing process The pre-annealed hybrid cable obtained in the coating process was annealed to obtain an annealed hybrid cable. The annealing temperature was set to 70°C and the annealing time was set to 12 hours.

[0159] (4) Evaluation The annealed hybrid cable was evaluated in the same manner as in Example A1.

[0160] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.08 (dB / 5m).

[0161] Example B2 (70°C for 24 hours) An annealed hybrid cable was obtained in the same manner as in Example B1, except that the annealing time was changed to 24 hours. The tension applied to the optical cable was 300 gf. The annealed hybrid cable was evaluated in the same manner as in Example B1.

[0162] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.09 (dB / 5m).

[0163] Example B3 (85°C for 12 hours) An annealed hybrid cable was obtained in the same manner as in Example B1, except that the annealing temperature was changed to 85° C. The tension applied to the optical cable was 300 gf. The annealed hybrid cable was evaluated in the same manner as in Example B1.

[0164] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.23 (dB / 5m).

[0165] Example B4 (85°C 24 hours) A hybrid cable after annealing was obtained in the same manner as in Example B1, except that the annealing temperature was changed to 85°C and the annealing time was changed to 24 hours. The tension applied to the optical cable was 300 gf. Also, the hybrid cable after annealing was evaluated in the same manner as in Example B1.

[0166] Then, for the four plastic optical fibers, the average value of the change in the optical loss coefficient was calculated. The average value of the change in the optical loss coefficient was 0.26 (dB / 5m).

[0167] <C: Tension 300 gf, 8 tensile strength fibers> Example C1 (4th, 70°C, 12 hours) One optical cable containing four plastic optical fibers, one electrical signal cable consisting of differential wiring, one power supply line including a power supply wire and a ground wire, and eight tensile strength fibers were assembled while being twisted to obtain a twisted cable as an assembled wire.

[0168] In the assembly process, the tension applied to the optical cable was 300 gf.

[0169] (2) Coating process A sheath was extruded around the twisted cable obtained in the assembly process to obtain a hybrid cable before annealing.

[0170] (3) Annealing process The hybrid cable before annealing obtained in the coating process was annealed to obtain a hybrid cable after annealing. The annealing temperature was set to 70°C. Also, the annealing time was set to 12 hours.

[0171] (4) Evaluation The hybrid cable after annealing was evaluated in the same manner as in Example A1.

[0172] Then, for the four plastic optical fibers, the average value of the change in the optical loss coefficient was calculated. The average value of the change in the optical loss coefficient was 0.08 (dB / 5m).

[0173] Example C2 (70°C 24 hours) An annealed hybrid cable was obtained in the same manner as in Example C1, except that the annealing time was changed to 24 hours. The tension applied to the optical cable was 300 gf. The annealed hybrid cable was evaluated in the same manner as in Example C1.

[0174] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.08 (dB / 5m).

[0175] Example C3 (85°C for 12 hours) An annealed hybrid cable was obtained in the same manner as in Example C1, except that the annealing temperature was changed to 85° C. The tension applied to the optical cable was 300 gf. The annealed hybrid cable was evaluated in the same manner as in Example C1.

[0176] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.35 (dB / 5m).

[0177] Example C4 (85°C 24 hours) An annealed hybrid cable was obtained in the same manner as in Example C1, except that the annealing temperature was changed to 85°C and the annealing time was changed to 24 hours. The tension applied to the optical cable was 300 gf. The annealed hybrid cable was also evaluated in the same manner as in Example C1.

[0178] The average change in the optical loss coefficient was calculated for the four plastic optical fibers, and the average change in the optical loss coefficient was 0.40 (dB / 5m).

[0179] Table 1 shows the relationship between the tension Gc applied to the optical cable in the assembling step, the heating temperature T and heating time t in the annealing step, and the average change in the optical loss coefficient for each of the examples and comparative examples.

[0180] [Table 1] [Explanation of symbols]

[0181] 1 Hybrid Cable 2 Optical Cable 3 Electrical signal cables 4 Power line 5 Sheath 10 stranded cable 11 Hybrid cable before annealing 12 Annealed hybrid cable 21 Plastic Optical Fiber 22 Optical fiber coating material 31 Differential wiring 31A 1st wiring 31B 2nd wiring 32 Shielding material 41 Power line 42 Ground Line 310 core wire 311 Covering material

Claims

1. A method for manufacturing a hybrid cable, comprising: The hybrid cable comprises: Sheath and an optical cable disposed inside the sheath; a power line disposed between the sheath and the optical cable; It is equipped with The optical cable includes an optical fiber coating material and a plastic optical fiber disposed inside the optical fiber coating material, The manufacturing method includes: an assembling step of assembling the optical cable and the power line to obtain an assembled cable; a covering step of covering the stranded wire with a sheath to obtain the hybrid cable; an annealing step of annealing the hybrid cable; Equipped with In the assembling step, a tension Gc (gf) applied to the optical cable is 900 gf or less, The tension Gc (gf) applied to the optical cable; and a heating temperature T (°C) in the annealing step satisfy the following formula (1): Gc(gf)≦-24T(℃)+2900 (1)

2. In the assembling step, a tension Gc (gf) applied to the optical cable is 300 gf or more and 900 gf or less, The heating temperature in the annealing step is 60.0°C or higher and 85.0°C or lower, The method for producing a hybrid cable according to claim 1 , wherein the heating time in the annealing step is from 1 hour to 24 hours.

3. The heating temperature in the annealing step is 60.0°C or higher and 85.0°C or lower, The method for producing a hybrid cable according to claim 1, wherein the heating time in the annealing step is 12 hours or more and 24 hours or less.

4. The tension Gc (gf) applied to the optical cable; The method for producing a hybrid cable according to claim 1 , wherein the heating temperature T (° C.) in the annealing step satisfies the following formula (2): Gc(gf)≦-24T(℃)+2340 (2)

5. 2. The method for manufacturing a hybrid cable according to claim 1, wherein in the assembling step, a tension Gc (gf) applied to the optical cable and / or a tension G (gf) applied to the power line is 50 gf or more.

6. The method for producing a hybrid cable according to claim 1 , wherein a tension Gc (gf) applied to the optical cable in the assembling step is 200 gf or more.

7. The method for producing a hybrid cable according to claim 1 , wherein a tension Gc (gf) applied to the optical cable in the assembling step is 300 gf or more.

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