fiber optic cable

Abstract

An optical fiber cable (10) comprising: a cable core (4) including a plurality of optical fiber core wires (411) or a plurality of optical fiber ribbons (411); a cable jacket (6) disposed outside of the cable core (4); a plurality of subunits (41) that are disposed within the cable core (4) and include a covering material (412) for covering the plurality of optical fiber core wires (411) or the plurality of optical fiber ribbons (411); and at least one tensile strength body (7) that is embedded into the cable jacket (6). The cable jacket (6) has a dynamic friction coefficient of 0.5 or less with respect to a metal plate, and the covering material (412) has an oxygen index of at least 40.

Description

[Technical Field]

[0001] The present disclosure relates to fiber optic cables. [Background technology]

[0002] US Patent No. 5,949,949 discloses an optical fiber cable including an optical fiber ribbon within a pipe, in which at least two optical fibers included in the ribbon are intermittently spliced ​​along the length of the fiber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japan Special Publication No. 2015-517679 Summary of the Invention

[0004] An optical fiber cable according to one aspect of the present disclosure includes: a cable core including a plurality of optical fiber core wires or a plurality of optical fiber ribbon core wires; a cable jacket disposed on the outside of the cable core; a plurality of subunits each including a coating material covering a plurality of the optical fibers or a plurality of the optical fiber ribbons, which are disposed within the cable core; at least one tensile strength member embedded in the cable jacket; The cable jacket has a coefficient of dynamic friction with respect to a metal plate. 0.3 is as follows: The coating material has an oxygen index of 40 or more. the law of nature, The cable further includes a pressure winding tape wound around the outer periphery of the cable core, At least a portion of the pressure wrapping tape is flame retardant. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a diagram illustrating an optical fiber cable with a traction tool according to one aspect of the present embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a plan view showing the intermittent optical fiber ribbon in the longitudinal direction. [Figure 4] FIG. 4 is a diagram illustrating a measurement device for measuring the dynamic friction coefficient of an optical fiber cable according to one aspect of the present embodiment. [Figure 5] FIG. 5 is a diagram illustrating a pressure-feeding device for performing pressure-feeding evaluation of an optical fiber cable. DETAILED DESCRIPTION OF THE INVENTION

[0006] [Problem to be solved by this disclosure] In recent years, strict flame retardancy has been required for optical fiber cables installed in buildings. In addition, with the increase in the amount of information transmitted in recent years, multi-core optical fiber cables containing multiple optical fiber cores are required to have low friction so that they can be easily passed through, for example, ducts.

[0007] The present disclosure aims to provide an optical fiber cable having good low friction and flame retardancy.

[0008] [Effects of this disclosure] According to the present disclosure, an optical fiber cable having good low friction and flame retardancy can be provided.

[0009] [Description of the embodiments of the present disclosure] First, the contents of the embodiments of the present disclosure will be listed and described. An optical fiber cable according to one aspect of the present disclosure includes: (1) a cable core including a plurality of optical fiber core wires or a plurality of optical fiber ribbon core wires; a cable jacket disposed on the outside of the cable core; a plurality of subunits each including a coating material covering a plurality of the optical fibers or a plurality of the optical fiber ribbons, which are disposed within the cable core; at least one tensile strength member embedded in the cable jacket; The cable jacket has a coefficient of dynamic friction with respect to a metal plate. 0.3 is as follows: The coating material has an oxygen index of 40 or more. the law of nature, The cable further includes a pressure winding tape wound around the outer periphery of the cable core, At least a portion of the pressure wrapping tape is flame retardant. According to this configuration, the cable jacket has a dynamic friction coefficient of 0.5 or less against the metal plate, so this optical fiber cable has good low friction properties. Also, the coating material covering the multiple optical fiber cores or multiple optical fiber ribbon cores has an oxygen index of 40 or more, so this optical fiber cable has good flame retardancy. Thus, the optical fiber cable according to the above configuration has good low friction properties and flame retardancy. Furthermore, since the dynamic friction coefficient of the cable jacket is 0.3 or less, such an optical fiber cable has good insertion characteristics. Furthermore, since the oxygen index of the coating material is 40 or more, such an optical fiber cable has good flame retardancy. Thus, the optical fiber cable according to the above configuration has good insertion characteristics and flame retardancy. Furthermore, with this configuration, at least a portion of the pressure wrapping tape is flame retardant, so the flame retardancy of the optical fiber cable can be further improved.

[0011] In addition, in an optical fiber cable according to an aspect of the present disclosure, (3) A plurality of the strength members may be embedded at equal intervals within the layer of the cable jacket. With this configuration, multiple tensile strength members are embedded at equal intervals within the layers of the cable jacket, making it difficult for the optical fiber cable to bend in an anisotropic manner (whether or not there is a direction in which it is easier to bend). Note that "evenly" does not necessarily mean that the tensile strength members are spaced at exactly equal intervals, but rather that they are disposed approximately evenly.

[0012] In addition, in an optical fiber cable according to an aspect of the present disclosure, (4) The cable jacket may contain a halogen-free resin. According to this configuration, the cable jacket contains a non-halogen resin, which can contribute to reducing the environmental load.

[0014] In addition, in an optical fiber cable according to an aspect of the present disclosure, (6) A multi-fiber connector having 24 or more fibers may be connected to the ends of the plurality of coated optical fibers or the ends of the plurality of ribbon optical fibers. This configuration can reduce the time required to connect to other optical fibers or the like.

[0015] [Details of the embodiments of the present disclosure] Specific examples of optical fiber cables according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0016] An optical fiber cable 100 with a traction tool according to this embodiment will be described with reference to Figures 1 and 2. In the description of this embodiment, for the sake of convenience, the "front-rear direction" and "left-right direction" will be referred to as appropriate. These directions are relative directions set for the optical fiber cable 100 with a traction tool exemplified in Figure 1. Here, the "front-rear direction" refers to a direction that includes the "forward direction" and "rear direction" with respect to the figure. The "left-right direction" refers to a direction that includes the "left direction" and "right direction" with respect to the figure.

[0017] Fig. 1 is a diagram illustrating an optical fiber cable 100 with a pulling tool. Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1. As illustrated in Fig. 1, the optical fiber cable 100 with a pulling tool includes an optical fiber cable 10 and a pulling tool 20. The optical fiber cable 10 includes a cable main body 1, a plurality of multi-fiber connectors 2, and a pitch conversion part 3. The pulling tool 20 includes a protective tube 21 and a pulling eye 22.

[0018] The outer diameter of the optical fiber cable 10 is, for example, approximately 8 mm or more and 20 mm or less. The outer diameter of the optical fiber cable 10 according to this embodiment is approximately 20 mm. As illustrated in Fig. 2 , the optical fiber cable 10 includes a cable core 4, a holding and wrapping tape 5, a cable jacket 6, a tensile strength member 7, and a tear cord (fibrous inclusion) 8. The cable core 4, the holding and wrapping tape 5, the cable jacket 6, the tensile strength member 7, and the tear cord 8 are included in the cable main body 1.

[0019] The cable core 4 includes a plurality of subunits 41 and a water-absorbing material 42. In this embodiment, the cable core 4 includes nine subunits 41, but the number of subunits 41 included in the cable core 4 is not limited to this. In addition, each subunit 41 houses 96 optical fibers, but the number of optical fibers is also not limited to this. In this embodiment, the optical fiber cable 10 houses 864 optical fibers. Each subunit 41 includes a plurality of optical fiber ribbons 411 and a coating material 412.

[0020] Here, the optical fiber ribbon 411 will be described in detail with reference to Fig. 3. As illustrated in Fig. 3, the optical fiber ribbon 411 is an intermittently connected optical fiber ribbon in which a plurality of optical fibers 411A to 411L are arranged in parallel in a direction perpendicular to the longitudinal direction of the plurality of optical fibers 411A to 411L, and in which connected portions 413 where adjacent optical fibers are connected and non-connected portions 414 where adjacent optical fibers are not connected are intermittently provided in the longitudinal direction among some or all of the plurality of optical fibers 411A to 411L. In this embodiment, the optical fiber ribbon 411 includes 12 optical fibers (optical fibers 411A to 411L). Therefore, each subunit 41 houses eight optical fiber ribbons 411. The outer diameter of each of the optical fibers 411A to 411L is, for example, 180 µm or 200 µm. The ultraviolet curing resin that coats the glass of each of the optical fibers 411A to 411L may be made flame-retardant. Specifically, a flame retardant, which will be described later, may be mixed into the ultraviolet curing resin.

[0021] The connecting portions 413 of the optical fiber ribbon 411 are formed by applying a connecting resin 415, such as an ultraviolet-curable resin or a thermosetting resin, between the optical fibers. By applying the connecting resin 415 between predetermined spaces between the optical fibers, the connecting portions 413 and the non-connecting portions 414 are intermittently provided, and the optical fibers 411A-411L are integrated in a parallel state. The connecting resin 415 may be applied to only one side of the parallel surfaces formed by the parallel optical fibers 411A-411L, or may be applied to both sides. The optical fiber ribbon 411 may also be fabricated by, for example, applying a ribbon resin to one or both sides of the parallel optical fibers 411A-411L to connect all of the parallel optical fibers 411A-411L, and then cutting a portion with a rotary blade or the like to form the non-connecting portions 414.

[0022] Returning to FIG. 2, the coating material 412 will be described. The coating material 412 is arranged so as to cover the optical fiber ribbon 411. The coating material 412 has a substantially circular shape in a cross-sectional view of the cable. The coating material 412 is made of a flame-retardant resin material, for example, made by adding a flame-retardant inorganic substance such as magnesium hydroxide or aluminum hydroxide to a material such as vinyl chloride resin or polyolefin resin. Therefore, the coating material 412 is flame-retardant. In this embodiment, the oxygen index of the coating material 412 is 40 or higher.

[0023] The pressure wrapping tape 5 is wound around the outer periphery of the cable core 4. The thickness of the pressure wrapping tape 5 is, for example, 0.13 mm or more and 0.15 mm or less. The pressure wrapping tape 5 includes an inner layer 51 and an outer layer 52. In other words, the pressure wrapping tape 5 has a two-layer structure. However, the structure of the pressure wrapping tape 5 is not limited to a two-layer structure. In the case of a two-layer structure, the inner layer 51 is formed from a water-absorbent tape. The water-absorbent tape is subjected to a water-absorbent treatment, for example, by adhering water-absorbent powder to a base fabric made of polyester or the like.

[0024] The outer layer 52 is formed from a substrate such as nonwoven fabric, PET, or glass. A flame retardant can be applied to the substrate. From the viewpoint of reducing the environmental impact, the flame retardant is preferably a non-halogen flame retardant such as a metal hydroxide, a nitrogen-based flame retardant, or a phosphorus-based flame retardant. However, the flame retardant may also be a halogen-based flame retardant such as a bromine-based flame retardant or a chlorine-based flame retardant. In this way, a part of the pressure wrapping tape 5 (the outer layer 52 in this embodiment) is flame retardant.

[0025] The cable jacket 6 is formed by extruding a resin around the cable core 4 around which the pressure wrapping tape 5 is wound. The thickness of the cable jacket 6 is, for example, 2.5 mm. The dynamic friction coefficient of the cable jacket 6 against metal plates (for example, the first metal plate 201 and the second metal plate 202 illustrated in FIG. 4) is, for example, 0.5 or less.

[0026] The cable sheath 6 is formed from a vinyl chloride resin, a halogen-free resin, or the like. Examples of the halogen-free resin include cross-linked polyethylene, polypropylene, polybutylene terephthalate, urethane, and nylon. When the cable sheath 6 is formed from a highly flame-retardant polyolefin (an example of a halogen-free resin), the flame retardancy of the cable sheath 6 can be enhanced. The cable sheath 6 may contain a silicon-based lubricant, such as silicone or siloxane. In this case, the cable sheath 6 has low friction. The coefficient of dynamic friction of the cable sheath 6 with respect to a metal plate may be, for example, 0.3 or less. A plurality of strength members 7 are embedded within the cable sheath 6 at equal intervals. However, the intervals between the strength members 7 need only be approximately equal. In this embodiment, 16 strength members 7 are embedded within the cable sheath 6.

[0027] The diameter of the tension member 7 is, for example, 0.5 mm. The tension member 7 is formed of fiber reinforced plastic (FRP), such as aramid FRP, glass FRP, or carbon FRP. However, the tension member 7 may also be formed of a liquid crystal polymer. It is preferable that the tension member 7 be non-inductive. Note that fiber reinforced plastic (FRP) is generally a flammable material. From the perspective of improving the flame retardancy of the entire optical fiber cable 10, it is preferable that the tension member 7 be positioned inside the cable jacket 6, closer to the center of the optical fiber cable 10, rather than near the surface of the cable jacket 6.

[0028] The tear cord 8 is provided for tearing the cable jacket 6. The tear cord 8 is arranged linearly within the layer of the cable jacket 6 along the longitudinal direction of the optical fiber cable 10, along the stranded optical fiber ribbons 411. In this embodiment, two tear cords 8 are provided. The two tear cords 8 are arranged so as to face each other in a cross-sectional view of the cable. By pulling out the tear cord 8, an operator can tear the cable jacket 6 in the longitudinal direction and remove the subunit 41. The tear cord 8 is fibrous and is formed, for example, from a tensile-resistant plastic material (e.g., polyester).

[0029] Returning to FIG. 1, the multi-fiber connector 2 will be described. The multi-fiber connector 2 is, for example, a small 192-fiber connector. However, the multi-fiber connector 2 is not limited to a 192-fiber connector as long as it has 24 or more fibers. Furthermore, a combination of multi-fiber connectors 2 with different numbers of fibers may be used. The optical fiber cable 10 includes, for example, four 192-fiber connectors and one 96-fiber connector. The multi-fiber connectors 2 are housed in a protective tube 21. Note that, for convenience of illustration, only three multi-fiber connectors 2 are shown in FIG. 1. The multi-fiber connectors 2 are connected to the end of the optical fiber ribbon 411 (see FIG. 3). However, the multi-fiber connectors 2 may also be connected to the end of the optical fiber core wires 411A to 411L (see FIG. 3).

[0030] The pitch conversion unit 3 is provided between an end of the optical fiber ribbon 411 and an end of the multi-fiber connector 2. The pitch conversion unit 3 is configured to convert the pitch of the optical fibers 411A-411L. In this embodiment, the pitch of the optical fibers 411A-411L in the optical fiber ribbon 411 is 200 μm, and the arrangement pitch in the multi-fiber connector 2 is 250 μm. The pitch conversion unit 3 converts the pitch of the optical fibers 411A-411L from 200 μm to 250 μm by separating the optical fibers 411A-411L into single fibers and widening the pitch. This allows the optical fibers 411A-411L to be connected to the multi-fiber connector 2 at a pitch of 250 μm. The pitch conversion unit 3 may be omitted if there is no need to convert the pitch.

[0031] The protective tube 21 is substantially cylindrical. The front end of the protective tube 21 is spherical. The outer diameter of the protective tube 21 is, for example, 25 mm or less. The protective tube 21 is provided at the front end of the optical fiber cable 100 with a traction tool. The surface of the protective tube 21 is covered with, for example, polyvinyl chloride or the like. The outer diameter of the protective tube 21 is larger than the outer diameter of the cable main body 1 and the outer diameter of the pulling eye 22.

[0032] The rear end of the pulling eye 22 is connected to the front end of the protective tube 21. The pulling eye 22 is made of a material that is strong enough to pull the optical fiber cable 10. Such a material is, for example, a metal such as iron. The pulling eye 22 has a hollow portion 221. An installer (worker) can pull the optical fiber cable 10 by, for example, connecting a wire or the like to the hollow portion 221 and pulling the wire with a winch.

[0033] (Measurement of the coefficient of dynamic friction in cable jacket) The inventors conducted an experiment using a measuring device 200 illustrated in Fig. 4 to measure the dynamic friction coefficient of the cable sheath 6. As illustrated in Fig. 4, the measuring device 200 includes a first metal plate 201, a second metal plate 202, and four cylindrical members 203. The four cylindrical members 203 are inserted into holes provided at the four corners of the first metal plate 201 and the second metal plate 202. For convenience of illustration, only two cylindrical members 203 are shown in Fig. 4. The first metal plate 201 and the second metal plate 202 are flat stainless steel plates to simulate the wall surfaces of a duct used when installing an optical fiber cable.

[0034] The inventors measured the dynamic friction coefficient of the cable sheath by sandwiching an optical fiber cable between a first metal plate 201 and a second metal plate 202 disposed above the first metal plate 201, applying a load to the second metal plate 202, and then pulling the optical fiber cable in the longitudinal direction of the metal plate (to the right in FIG. 4 ). In this experiment, a load of approximately 2.0 kg was applied to the second metal plate 202. The length of the optical fiber cable was approximately 300 mm. The length of the first metal plate 201 and the second metal plate 202 in the longitudinal direction was approximately 150 mm. The pulling speed of the optical fiber cable was approximately 500 mm / min. In this embodiment, the dynamic friction coefficient was evaluated using the average value of the pulling tension. The optical fiber cable used in this experiment was the 864-fiber optical fiber cable illustrated in FIG. 1.

[0035] (Optical fiber cable pressure feeding evaluation) In order to evaluate the pumping performance of optical fiber cable 10, the inventors conducted a pumping test in accordance with IEC using pumping device 300 illustrated in Fig. 5. Pipe 301 was 1000 m long and was folded back every 100 m. The radius of curvature R of pipe 301 was 40 times the inner diameter of the pipe, and the inner diameter of pipe 301 was 30 mm. The outer diameter of optical fiber cable 10 was 20 mm. Opening 302 was an inlet for air and the optical fiber cable, and opening 303 was an outlet for air and the optical fiber cable. The air pressure was set to 1.3 MPa or more and 1.5 MPa or less.

[0036] In the pumping experiment, pumping distances of 2000 m or more were evaluated as very good, pumping distances of 1000 m or more but less than 2000 m were evaluated as good, and pumping distances of less than 1000 m were evaluated as poor. Note that the longer the pumping distance, the better the insertion characteristics of the optical fiber cable. In other words, the longer the pumping distance, the better the low friction of the optical fiber cable.

[0037] (Evaluation of flame retardancy of optical fiber cables) In order to evaluate the flame retardancy of the optical fiber cable 10, the inventors conducted a combustion test according to the plenum test UL910 (NFPA262) and a combustion test based on the European Construction Products Regulation (CPR).

[0038] In the plenum test UL910, flame retardancy is evaluated by conducting a flame test according to the flame retardancy standard established by UL (Underwriters Laboratory). Although the flame test may vary depending on the shape of the sample, grades such as CMX (flammability test, usually referred to as VW-1 test), CM (vertical tray flame test), CMR (riser test), and CMP (plenum test) are generally established in order of decreasing flame resistance. The plenum test employed in this embodiment is a test designed to simulate an optical fiber cable being installed in a plenum space, which is a space where air is constantly flowing due to air conditioning. The plenum space is, for example, an attic. In the plenum test according to this embodiment, the flame retardancy of the optical fiber cable was evaluated by igniting the optical fiber cable placed in the plenum space and evaluating the flame spread and smoke generation of the optical fiber cable.

[0039] In this embodiment, optical fiber cables that met the predetermined standards in the plenum test UL910 combustion test were evaluated as good, and optical fiber cables that did not meet the predetermined standards were evaluated as poor.

[0040] In a combustion test based on the European Construction Materials Regulation, multiple optical fiber cables were burned for 20 minutes using a 20kW burner, and the flame retardancy of the optical fiber cables was evaluated by measuring the damage length, smoke generation, total heat generation, and heat release rate. Specifically, the flame retardancy was evaluated based on the damage length, smoke release rate, and total heat release rate. The heat release rate is the energy generated when something burns, and the total heat release rate is the cumulative heat release rate from the start of combustion to the end of combustion. The optical fiber cables were 3.5m long. The combustion test conformed to the international flame retardancy standard EN50399.

[0041] In this embodiment, optical fiber cables that comply with Class B or higher in the CPR standard were rated as very good, optical fiber cables that comply with Class C in the CPR standard were rated as good, and optical fiber cables that do not comply with Class C or higher in the CPR standard were rated as poor.

[0042] Table 1 shows the results of the experiments on the optical fiber cables according to Experimental Examples 1 to 4. [Table 1]

[0043] Experimental Example 1 will be described. The coating material of the optical fiber cable according to Experimental Example 1 had an oxygen index of 45, and the cable jacket had an oxygen index of 42. As a result of the above experiment, the dynamic friction coefficient of the cable jacket of the optical fiber cable according to Experimental Example 1 was 0.7. When the optical fiber cable according to Experimental Example 1 was pumped through pipe 301, the pumping distance was 600 m. Therefore, the pumping evaluation of the optical fiber cable according to Experimental Example 1 was poor.

[0044] The optical fiber cable according to Experimental Example 1 met the prescribed standards in the plenum test UL 910 combustion test, and was therefore evaluated as good in the plenum test UL 910 combustion test. In addition, the optical fiber cable according to Experimental Example 1 conformed to Class B in the CPR standard, and was therefore evaluated as very good in the combustion test based on the European Construction Materials Regulation.

[0045] Experimental Example 2 will be described. The coating material of the optical fiber cable according to Experimental Example 2 had an oxygen index of 38, and the cable jacket had an oxygen index of 40. As a result of the above experiment, the dynamic friction coefficient of the cable jacket of the optical fiber cable according to Experimental Example 2 was 0.45. When the optical fiber cable according to Experimental Example 2 was pumped through pipe 301, the pumping distance was 1100 m. Therefore, the pumping evaluation of the optical fiber cable according to Experimental Example 2 was good.

[0046] The optical fiber cable according to Experimental Example 2 did not meet the prescribed standards in the plenum test UL 910 combustion test, and was therefore evaluated as poor in the plenum test UL 910 combustion test. In addition, the optical fiber cable according to Experimental Example 2 complied with Class C in the CPR standard, and was therefore evaluated as good in the combustion test based on the European Construction Materials Regulation.

[0047] Experimental Example 3 will be described. The coating material of the optical fiber cable according to Experimental Example 3 had an oxygen index of 45, and the cable jacket had an oxygen index of 40. As a result of the above experiment, the dynamic friction coefficient of the cable jacket of the optical fiber cable according to Experimental Example 3 was 0.5. When the optical fiber cable according to Experimental Example 3 was pumped through pipe 301, the pumping distance was 1000 m. Therefore, the pumping evaluation of the optical fiber cable according to Experimental Example 3 was good.

[0048] The optical fiber cable according to Experimental Example 3 met the prescribed standards in the plenum test UL 910 combustion test, and was therefore evaluated as good in the plenum test UL 910 combustion test. In addition, the optical fiber cable according to Experimental Example 3 conformed to Class B in the CPR standard, and was therefore evaluated as very good in the combustion test based on the European Construction Materials Regulation.

[0049] Experimental Example 4 will be described. The coating material of the optical fiber cable according to Experimental Example 4 had an oxygen index of 40, and the cable jacket had an oxygen index of 38. As a result of the above experiment, the dynamic friction coefficient of the cable jacket of the optical fiber cable according to Experimental Example 4 was 0.3. When the optical fiber cable according to Experimental Example 4 was pumped through pipe 301, the pumping distance was 2000 m. Therefore, the pumping evaluation of the optical fiber cable according to Experimental Example 4 was very good.

[0050] The optical fiber cable according to Experimental Example 4 met the prescribed standards in the plenum test UL 910 combustion test, and was therefore evaluated as good in the plenum test UL 910 combustion test. In addition, the optical fiber cable according to Experimental Example 4 conformed to Class C in the CPR standard, and was therefore evaluated as good in the combustion test based on the European Construction Materials Regulation.

[0051] From the above results, it was confirmed that the optical fiber cable 10 in which the coefficient of dynamic friction of the cable jacket 6 against the metal plate is 0.5 or less has good insertion characteristics.

[0052] Furthermore, from the above results, it was confirmed that optical fiber cable 10 in which the dynamic friction coefficient of cable jacket 6 is 0.3 or less has particularly good insertion characteristics.

[0053] Furthermore, the results of the plenum test UL910 combustion test and the combustion test based on the European Construction Materials Regulation confirmed that the optical fiber cable 10 having the coating material 412 with an oxygen index of 40 or more has good flame retardancy.

[0054] According to the optical fiber cable 10 described above, the coefficient of dynamic friction between the cable jacket 6 and the metal plate is 0.5 or less, and therefore the optical fiber cable 10 has good low friction properties. Furthermore, if the oxygen index of the coating material 412 is 40 or more, the optical fiber cable 10 has good flame retardancy. Thus, the optical fiber cable 10 has good low friction properties and flame retardancy.

[0055] Furthermore, according to the optical fiber cable 10, if the coefficient of dynamic friction of the cable jacket 6 is 0.3 or less, the optical fiber cable 10 has better insertion characteristics.

[0056] Furthermore, according to the optical fiber cable 10, a plurality of tension members 7 are embedded at equal intervals in the cable jacket 6. Therefore, in the optical fiber cable 10, bending anisotropy is unlikely to occur.

[0057] Furthermore, according to the optical fiber cable 10, the cable jacket 6 contains a non-halogen resin, which can contribute to reducing the environmental load.

[0058] Furthermore, according to the optical fiber cable 10, the outer layer 52 of the holding wrapping tape 5 is flame retardant, so that the flame retardancy of the optical fiber cable 10 can be further improved.

[0059] Furthermore, according to the optical fiber cable 10, the coating material 412 included in each subunit 41 has flame retardancy. That is, since each subunit 41 can have flame retardancy, even a single subunit can have flame retardancy.

[0060] Furthermore, according to the optical fiber cable 10, a 192-core multi-core connector 2 and a 96-core multi-core connector 2 are connected to the ends of the plurality of optical fiber ribbons 411. In other words, a multi-core connector with 24 or more cores is connected to the ends of the plurality of optical fiber ribbons 411. Therefore, according to the optical fiber cable 10, it is possible to reduce the time required for connection to other optical fibers, etc.

[0061] Although the present disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the number, position, shape, etc. that are suitable for implementing the present disclosure.

[0062] In the above embodiment, the optical fiber cable 10 includes the multi-fiber connector 2 and the pitch conversion portion 3, but it is not necessary to include at least one of the multi-fiber connector 2 and the pitch conversion portion 3.

[0063] In the above embodiment, the number of multi-fiber connectors 2 provided in the optical fiber cable 10 and the number of fibers in the multi-fiber connector 2 are not limited to the numbers exemplified in the above embodiment. For example, the optical fiber cable 10 may include nine 96-fiber connectors.

[0064] In the above embodiment, the cable core 4 accommodates a plurality of optical fibers bundled together as the optical fiber ribbon 411, but each of the plurality of optical fibers may be a single optical fiber.

[0065] In the above embodiment, the optical fiber cable 10 includes the pressure winding tape 5, but the pressure winding tape 5 may not be included. [Explanation of symbols]

[0066] 1: Cable body 2: Multi-core connector 3: Pitch conversion section 4: Cable core 5: Presser tape 6: Cable sheath 7:Tensile strength body 8: Tear string 10: Fiber optic cable 20: Traction device 21: Protection tube 22: Pooling Eye 41: Subunit 42: Water absorbing material 51: Inner layer 52: Outer layer 100: Fiber optic cable with traction device 200: Measuring equipment 201:First metal plate 202:Second metal plate 203: Cylindrical member 221: Cavity 300: Pressure feeding device 301: Pipe 302,303:Aperture 411: Optical fiber ribbon 411A~411L: Optical fiber core 412: Covering material 413:Connection part 414: Unconnected part 415: Connected resin R: Pipe bend

Claims

1. a cable core including a plurality of optical fiber core wires or a plurality of optical fiber ribbon core wires; a cable jacket disposed on the outside of the cable core; a plurality of subunits each including a coating material covering a plurality of the optical fibers or a plurality of the optical fiber ribbons, which are disposed within the cable core; at least one tensile strength member embedded in the cable jacket; the cable sheath has a dynamic friction coefficient with respect to a metal plate of 0.3 or less; The coating material has an oxygen index of 40 or more, The cable further includes a pressure winding tape wound around the outer periphery of the cable core, An optical fiber cable, wherein at least a portion of the pressure wrapping tape is flame retardant.

2. 2. The optical fiber cable according to claim 1, wherein a plurality of said strength members are embedded at equal intervals within said layer of said cable jacket.

3. 3. The optical fiber cable according to claim 1, wherein the cable jacket contains a halogen-free resin.

4. 4. The optical fiber cable according to claim 1, wherein a multi-fiber connector having 24 or more fibers is connected to ends of a plurality of the optical fiber core wires or ends of a plurality of the optical fiber ribbon core wires.

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