Storage structure, optical cable with towing end, and method for manufacturing storage structure

Abstract

[Problem] To make a housing more compact that houses a plurality of optical connectors. [Solution] In this housing structure, each connector unit (20) has: a first tube (21) having a plurality of optical fibers (3) inserted therein; a plurality of second tubes (22) through which each of the optical fibers (3) branched from the first tube (21) are inserted; and a connector group (23) comprising a plurality of optical connectors (10) provided in an end section of each of the second tubes (22). Each of the connector groups (23) in the plurality of connector units (20) has a different position in the longitudinal direction and, when the shortest connector unit (20) is the first connector unit, a plurality of first tubes (21) for a connector unit (20) other than the first connector unit are present in an area occupied by a connector group (23) for the first connector unit (20). In at least one connector unit (20) having a connector group disposed further on the tip side than the connector group (23) for the first connector unit, second tubes (22) for a connector unit (20) that is next longest after that connector unit (20) are present in an area in the longitudinal direction occupied by the connector group (23) for that connector unit.

Description

[Technical field]

[0001] The present disclosure relates to an encasement structure, an optical cable with a towing end, and a method for manufacturing the encasement structure. [Background technology]

[0002] Patent Document 1 describes a cable pulling terminal structure used when pulling an optical cable by a pulling device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-217316 A Summary of the Invention [Problem to be solved by the invention]

[0004] An optical cable is laid from outside the station into the station by pulling the pulling portion of the optical cable with a pulling end. In this case, if an optical connector is attached in advance to the end of the optical fiber of the optical cable and the optical connector is housed inside the pulling terminal structure, the laying work in the station after the optical cable is pulled is convenient. However, when a large number of optical connectors are housed, the housing may become large. Note that there is also a demand to miniaturize housings that house not only optical cables with a pulling end, but also multiple optical connectors provided at the ends of optical cables.

[0005] An object of the present invention is to reduce the size of a housing that houses an optical connector. [Means for solving the problem]

[0006] The first main invention for achieving the above object is a housing structure comprising an optical cable having a plurality of optical fibers, a plurality of connector units branched from the optical cable, and a housing body accommodating the plurality of connector units, each of the connector units having a first tube through which the plurality of optical fibers are inserted, a plurality of second tubes through which the optical fibers branched from the first tube are respectively inserted, and a connector group consisting of a plurality of optical connectors provided at an end of each of the second tubes, the connector group of each of the plurality of connector units being positioned in a different longitudinal direction, and when the shortest connector unit is defined as a first connector unit, the plurality of first tubes of the connector units other than the first connector unit are present in an area occupied by the connector group of the first connector unit in the longitudinal direction, and in at least one connector unit in which the connector group is arranged further toward the tip than the connector group of the first connector unit, the second tube of the connector unit next to the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction. A second main invention for achieving the above object is an optical cable with a towing end, comprising: an optical cable having a plurality of optical fibers; a plurality of connector units branched from the optical cable; and a housing for accommodating the plurality of connector units, each of the connector units having a first tube through which the plurality of optical fibers are inserted, a plurality of second tubes through which the optical fibers branched from the first tube are respectively inserted, and a connector group consisting of a plurality of optical connectors provided at an end of each of the second tubes, the connector group of each of the plurality of connector units being located at different positions in the longitudinal direction, and when the shortest connector unit is defined as a first connector unit, the plurality of first tubes of the connector units other than the first connector unit are present in an area occupied by the connector group of the first connector unit in the longitudinal direction, and in at least one connector unit in which the connector group is arranged further toward the tip than the connector group of the first connector unit, the second tube of the connector unit next to the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction. Further, a third main invention for achieving the above object is a method for manufacturing a storage structure, which involves inserting multiple optical fibers branched from an optical cable into a first tube, inserting multiple optical fibers branched from the first tube into a second tube, and providing an optical connector at an end of the optical fiber inserted into the second tube, thereby creating multiple connector units branched from the optical cable, each having a first tube, multiple second tubes, and a connector group consisting of multiple optical connectors provided at an end of each of the second tubes, and accommodating multiple of the connector units in a housing, wherein when the shortest connector unit is the first connector unit, multiple first tubes of connector units other than the first connector unit are present in an area occupied by the connector group of the first connector unit in the longitudinal direction, and in at least one connector unit in which the connector group is arranged further tip-side than the connector group of the first connector unit, the second tube of the connector unit next to the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction.

[0007] Other features of the present invention will become apparent from the following specification and drawings. Effect of the Invention

[0008] According to the present invention, it is possible to reduce the size of a housing that houses an optical connector. [Brief description of the drawings]

[0009] [Figure 1] Fig. 1A is an explanatory diagram of the appearance of an optical cable with a towing end 100 according to this embodiment. Fig. 1B is an explanatory diagram of the internal structure of the optical cable with a towing end 100 according to this embodiment. [Diagram 2] FIG. 2 is an explanatory diagram of the optical cable 1. [Diagram 3] FIG. 3 is an explanatory diagram of a terminal structure 50 of a modified example. [Figure 4] FIG. 4 is an explanatory diagram of the connector unit 20 extending from the outlet of the optical cable 1. As shown in FIG. [Diagram 5] 5A and 5B are explanatory diagrams of the tip portion of a connector unit 20. FIG. [Figure 6] Fig. 6A is an explanatory diagram of the optical connector 10 of this embodiment. Fig. 6B is an explanatory diagram of a state in which the cylindrical member 18 of Fig. 6A has been removed. Fig. 6C is an explanatory diagram of a state in which the cylindrical member 18 and the second tube 22 of Fig. 6A have been removed. [Figure 7] FIG. 7 is an exploded view of the optical connector 10 of the present embodiment. [Figure 8] FIG. 8 is an explanatory diagram of the arrangement of the connector group 23 in this embodiment. [Figure 9] FIG. 9 is an explanatory diagram of a first comparative example. [Figure 10] 10A and 10B are comparative explanatory diagrams of the arrangement of the connector group 23. Fig. 10A shows the arrangement of the connector group 23 of this embodiment. Fig. 10B shows the arrangement of the connector group 23 of a second comparative example. [Figure 11] FIG. 11 is a flow diagram of a method for manufacturing the optical cable with a pulling end 100 of this embodiment. [Figure 12] 12A to 12F are explanatory diagrams of the manufacturing process of the optical cable with a pulling end 100 of this embodiment. [Figure 13] FIG. 13 is an explanatory diagram of a state in which an optical cable is laid from the outside of a station to the inside of the station by pulling the pulling portion of an optical cable with a pulling end. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] At least the following points will become apparent from the following specification and drawings.

[0011] an optical cable having a plurality of optical fibers; a plurality of connector units branched from the optical cable; a housing for housing a plurality of the connector units; Equipped with Each of the connector units comprises: a first tube through which a plurality of the optical fibers are inserted; a plurality of second tubes into which optical fibers branched from the first tube are inserted; a connector group consisting of a plurality of optical connectors provided at the end of each of the second tubes; having The connector groups of the respective connector units are located at different positions in a longitudinal direction, when the shortest connector unit is defined as a first connector unit, a region occupied in the longitudinal direction by the connector group of the first connector unit includes a plurality of first tubes of the connector units other than the first connector unit, In at least one connector unit in which the connector group is disposed on the distal end side of the connector group of the first connector unit, the second tube of the connector unit that is the second longest after the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction. According to such a storage structure, the diameter and length of the storage body can be reduced, and the storage body can be made compact.

[0012] When the second connector unit that is the next longest connector unit after the first connector unit is the second connector unit, a certain connector unit is the Nth connector unit, and the second longest connector unit after the Nth connector unit is the N+1th connector unit, and the second tube of the N+1th connector unit is present in an area occupied in the longitudinal direction by the connector group of the Nth connector unit, it is desirable that the longitudinal distance between the connector group of the Nth connector unit and the connector group of the N+1th connector unit is shorter than the longitudinal distance between the connector group of the first connector unit and the connector group of the second connector unit. This makes it possible to shorten the housing.

[0013] In a connector unit in which the connector group is disposed distally of the connector group of the Nth connector unit, it is desirable that the second tube of the other connector unit is present in an area occupied in the longitudinal direction by the connector group of the connector unit, thereby making it possible to further shorten the housing body.

[0014] an optical cable having a plurality of optical fibers; a plurality of connector units branched from the optical cable; a housing for housing a plurality of the connector units; Equipped with Each of the connector units comprises: a first tube through which a plurality of the optical fibers are inserted; a plurality of second tubes into which optical fibers branched from the first tube are inserted; a connector group consisting of a plurality of optical connectors provided at the end of each of the second tubes; having The connector groups of the respective connector units are located at different positions in a longitudinal direction, when the shortest connector unit is defined as a first connector unit, a region occupied in the longitudinal direction by the connector group of the first connector unit includes a plurality of first tubes of the connector units other than the first connector unit, In at least one connector unit in which the connector group is disposed on the distal end side of the connector group of the first connector unit, the second tube of the connector unit that is the second longest after the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction. The present invention relates to an optical cable with a pulling end, and more particularly to an optical cable with a pulling end.

[0015] It is preferable that the optical fiber cable further includes a braided tube that houses the housing, the braided tube has an end portion provided with a traction part, and the end portion of the braided tube opposite to the traction part is fixed to the optical cable. In this way, the pulling force during traction is applied to the braided tube and not directly to the housing, so that the diameter of the housing can be made thinner.

[0016] Inserting each of the optical fibers branched from an optical cable into a first tube, inserting each of the optical fibers branched from the first tube into a second tube, and providing an optical connector at an end of the optical fiber inserted into the second tube, thereby creating a plurality of connector units branched from the optical cable, each of which has a first tube, a plurality of second tubes, and a connector group consisting of a plurality of optical connectors provided at an end of each of the second tubes; and A plurality of the connector units are accommodated in a housing. A method for manufacturing a storage structure comprising the steps of: When the shortest connector unit is defined as a first connector unit, a region occupied in a longitudinal direction by the connector group of the first connector unit includes a plurality of first tubes of the connector units other than the first connector unit, In at least one connector unit in which the connector group is disposed on the distal end side of the connector group of the first connector unit, the second tube of the connector unit that is the second longest after the connector unit is disposed in an area occupied by the connector group of the connector unit in the longitudinal direction. The present invention relates to a method for manufacturing a storage structure having the above-mentioned features. The storage structure can be made thinner and shorter, and the storage structure can be made more compact.

[0017] ===This embodiment=== <Configuration of the optical cable 100 with towing end> Fig. 1A is an explanatory diagram of the appearance of an optical cable with a towing end 100 according to this embodiment. Fig. 1B is an explanatory diagram of the internal structure of the optical cable with a towing end 100 according to this embodiment.

[0018] In the following description, the longitudinal direction of the towing-end optical cable 100 is referred to as the "front-rear direction" as shown in Fig. 1A. In addition, the tip side as viewed from the towing-end optical cable 100 is referred to as the "front" and the opposite side is referred to as the "rear". Alternatively, the front side may be referred to as the "tip side" and the rear side as the "base side".

[0019] The optical cable with a towing end 100 is an optical cable having a towing portion at its end. As shown in Fig. 13, the optical cable 1 can be laid from outside the station to inside the station by pulling the towing portion of the optical cable with a towing end 100. The optical cable with a towing end 100 includes the optical cable 1 and a terminal structure 50.

[0020] FIG. 2 is an explanatory diagram of the optical cable 1.

[0021] The optical cable 1 is a cable that accommodates a large number of optical fibers 3 inside the jacket 4. The optical cable 1 has a plurality of optical fiber units 2, a pressure winding tape 5, and the jacket 4. The optical fiber unit 2 is a unit in which a plurality of optical fibers 3 are bundled together. Here, the optical fiber unit 2 is configured by bundling a plurality of intermittently fixed optical fiber tapes with a bundling material. The optical cable 1 of this embodiment has 288 optical fiber tapes (optical fiber ribbons) each composed of 12 optical fibers 3, and has a total of 3456 optical fibers 3. However, the number of optical fiber tapes and optical fibers 3 is not limited to this. The plurality of optical fiber units 2 are accommodated inside the jacket 4 in a state where they are wound around the pressure winding tape 5. A tension member 6 and a ripcord 7 are embedded in the jacket 4.

[0022] A large number of optical fibers 3 (optical fiber tapes) extend from the end of the optical cable 1. In this embodiment, 288 optical fiber tapes extend from the end of the optical cable 1 (note that in FIG. 1B, the number of optical fiber tapes is drawn to be smaller for simplification). An optical connector 10 is attached to the end of the optical fiber 3. The optical connector 10 in this embodiment is composed of a 24-core MPO connector. Therefore, 144 optical connectors 10 are attached to the optical cable 1 in this embodiment (note that in FIG. 1B, the number of optical connectors 10 is drawn to be smaller for simplification). The optical fibers 3 (optical fiber tapes) extending from the optical cable 1 are inserted into protective tubes (first tube 21, second tube 22) described later. The structure extending from the end of the optical cable 1 (connector unit 20 including the optical connector 10) will be described later.

[0023] The terminal structure 50 is a structure provided at the terminal of the optical cable 1. The terminal structure 50 of this embodiment is a pulling terminal structure having a pulling section 50A. The terminal structure 50 of this embodiment is a structure capable of pulling the optical cable 1 while accommodating a connector unit 20 (described later). The pulling section 50A is a portion for pulling the optical cable 1. The terminal structure 50 has a housing 51 and a braided tube 55.

[0024] The housing 51 is a housing member that houses multiple optical connectors 10 (and connector units 20 described later). The housing 51 of this embodiment has a housing tube 52, a housing tube fixing portion 53, and a front member 54. The internal space of the housing 51 becomes the housing space that houses the optical connectors 10 (and connector units 20 described later). In other words, the space surrounded by the housing tube 52, the housing tube fixing portion 53, and the front member 54 becomes the housing space. Note that a structure composed of the optical cable 1 and the housing 51 that houses multiple optical connectors 10 (and connector units 20 described later) is sometimes called a "housing structure."

[0025] The housing tube 52 is a cylindrical (tube-shaped) member that houses the optical connector 10. The housing tube 52 of this embodiment houses the connector unit 20 (described later) extending from the outlet of the optical cable 1. The housing tube 52 has a function of protecting the connector unit 20. In this embodiment, the housing tube 52 is made of a flexible tube (flexible tube), specifically, a corrugated tube. However, the housing tube 52 may be a tube other than the corrugated tube as long as it has flexibility to be bent in an underground conduit as shown in FIG. 13. The housing tube 52 is disposed inside the braided tube 55. A housing tube fixing part 53 is disposed on the rear side of the housing tube 52. The housing tube 52 is fixed to the optical cable 1 via the housing tube fixing part 53. A front member 54 is disposed on the front side of the housing tube 52.

[0026] The accommodating tube fixing part 53 is a member that fixes the accommodating tube 52 to the optical cable 1. The accommodating tube fixing part 53 is disposed near the outlet part 1A of the optical cable 1. The accommodating tube 52 is attached to the front side of the accommodating tube fixing part 53. The accommodating tube fixing part 53 fits into the rear edge of the accommodating tube 52 to reinforce the accommodating tube 52. The front member 54 is a member that constitutes the front part of the housing body 51. The front member 54 is fitted onto the front edge of the housing tube 52, thereby reinforcing the housing tube 52.

[0027] The braided tube 55 is a member in which a fiber member is woven into a tube shape. In other words, the braided tube 55 is a tube in which a fiber member is woven into a mesh shape. The fiber member constituting the braided tube 55 is, for example, a resin fiber or a metal wire. A traction part 50A is provided at the tip of the braided tube 55. When the traction part 50A is pulled, a large pulling force acts on the braided tube 55, but the braided tube 55 made of a large number of fiber members has sufficient durability against the pulling force. In addition, the braided tube 55 has a degree of flexibility that allows it to be bent in an underground pipe as shown in FIG. 13.

[0028] The braided tube 55 has a housing 51 disposed therein. The braided tube 55 has a function of protecting the housing 51 from friction with the inner wall surface of the underground pipe shown in FIG. 13. The end of the optical cable 1 is also housed inside the braided tube 55. The end of the base end side of the braided tube 55 is fixed to the optical cable 1 by the tube fixing part 56. For example, the tube fixing part 56 is composed of a heat shrink tube, and the rear edge of the braided tube 55 is sandwiched between the heat shrink tube and the optical cable 1, thereby fixing the braided tube 55 to the optical cable 1. The end of the tip side of the braided tube 55 is provided with a traction part 50A. The traction part 50A is a part that is towed by a traction device such as a winch. The traction part 50A is sometimes called a "towing end". The traction part 50A of this embodiment is configured by forming the excess part of the tip of the braided tube 55 into a ring shape. That is, in this embodiment, the traction part 50A is configured integrally with the braided tube 55. However, the traction portion 50A is not limited to this configuration, and may be provided on a member separate from the braided tube 55.

[0029] 3 is an explanatory diagram of a modified terminal structure 50. The modified terminal structure 50 includes a housing 51. As shown in this modified example, the terminal structure 50 does not need to include the braided tube 55 described above. The modified housing 51 includes a housing tube 52, a housing tube fixing portion 53, and a front member 54, and a traction portion 50A is provided on the front member 54. As shown in this modified example, the traction portion 50A does not need to be provided on the braided tube 55, and may be provided on the front part of the housing 51.

[0030] Incidentally, in the case of the terminal structure 50 of this embodiment shown in FIG. 1, the pulling force during towing is applied directly to the braided tube 55, and does not directly act on the encasing tube 52. Therefore, in this embodiment, it is possible to suppress the destruction of the encasing tube 52 due to the pulling force acting on the encasing tube 52. In contrast, in the case of the terminal structure 50 of the modified example shown in FIG. 3, the pulling force during towing is applied to the encasing tube 52. Since the encasing tube 52 made of a corrugated tube is relatively weak against the pulling force, it is difficult to reduce the diameter of the encasing tube 52 in order to make it structured to withstand the pulling force during towing. In contrast, in this embodiment, the pulling force during towing does not act on the encasing tube 52, so it is possible to reduce the diameter of the encasing tube 52.

[0031] On the other hand, the thinner the diameter of the accommodating tube 52, the narrower the accommodating space of the accommodating body 51. However, in this embodiment, as described below, it is possible to accommodate a large number of optical connectors 10 (here, 144 optical connectors 10) in the narrow accommodating space of the accommodating body 51.

[0032] <About the connector unit 20> Fig. 4 is an explanatory diagram of a connector unit 20 extending from an outlet portion of an optical cable 1. Figs. 5A and 5B are explanatory diagrams of a tip portion of a certain connector unit 20.

[0033] In this embodiment, a plurality of connector units 20 (here, nine units) branch out and extend from the outlet 1A of the optical cable 1. The plurality of connector units 20 are housed in a housing space of a housing body 51. In Fig. 4, for the purpose of explanation, the housing space of the housing body 51 is drawn expanded, and the plurality of connector units 20 are drawn spaced apart.

[0034] In the following description, the connector units 20 may be referred to in order from the shortest as the first connector unit 20A, the second connector unit 20B, ..., the ninth connector unit 20I. For this reason, when a certain connector unit 20 (excluding the longest connector unit 20) is referred to as the Nth connector unit 20, the next longest connector unit 20 after the Nth connector unit 20 is referred to as the N+1th connector unit 20.

[0035] One connector unit 20 includes a plurality of (here, 16) optical connectors 10, one first tube 21, and the same number of second tubes 22 as the optical connectors 10. The plurality of optical connectors 10 (here, 16 optical connectors 10) of the connector unit 20 may be referred to as a "connector group 23." Therefore, in other words, one connector unit 20 includes one first tube 21, a plurality of second tubes 22, and the connector group 23.

[0036] The first tube 21 is a member disposed closer to the base end than the multiple second tubes 22, and is a protective tube that protects the multiple optical fibers 3. The first tube 21 is sometimes called a "primary tube." Multiple optical fibers 3 branched from the optical cable 1 are inserted into the first tube 21. Here, 384 optical fibers (32 12-core optical fiber tapes) are inserted into the first tube 21. However, the number of optical fibers inserted into the first tube 21 is not limited to this.

[0037] The second tube 22 is a member disposed on the base end side of the optical connector 10, and is a protective tube that protects the optical fibers extending from the optical connector 10. A plurality of optical fibers 3 branched from the first tube 21 are inserted into the second tube 22. The second tube 22 is sometimes called a "secondary tube." The second tube 22 is disposed between the first tube 21 and the optical connector 10. As will be described later, the front end of the second tube 22 is attached to the optical connector 10. The rear end of the second tube 22 is disposed at the branching portion with the first tube 21.

[0038] Since a plurality of optical fibers branched from the first tube 21 are inserted into the second tube 22, the number of optical fibers inserted into the second tube 22 is smaller than the number of optical fibers inserted into the first tube 21. Here, 384 optical fibers (32 12-core optical fiber tapes) inserted into the first tube 21 are branched into 16, and 24 optical fibers (two 12-core optical fiber tapes) are inserted into the second tube 22. However, the number of optical fibers inserted into the second tube 22 is not limited to this. In this embodiment, one connector unit 20 has 16 second tubes 22. However, the number of second tubes 22 (or the number of branches of optical fibers) of each connector unit 20 is not limited to this.

[0039] The first tube 21 and the second tube 22 are each made of a braided tube. A braided tube is a member in which a fiber material is woven into a tube shape. In this embodiment, the first tube 21 and the second tube 22 are made of polyester resin fiber. However, the material of the first tube 21 and the second tube 22 is not limited to polyester. In addition, the first tube 21 and the second tube 22 do not have to be made of a braided tube. For example, the first tube 21 and the second tube 22 can also be made of a silicon tube.

[0040] The second tube 22 has a smaller inner diameter and outer diameter than the first tube 21 because the number of optical fibers inserted therethrough is smaller. However, the number of second tubes 22 is greater than the number of first tubes 21, and in this embodiment, 16 second tubes 22 are provided for one first tube 21. In this embodiment, the total cross-sectional area of ​​the multiple (16 here) second tubes 22 in one connector unit 20 is greater than the cross-sectional area of ​​the first tube 21. In this embodiment, the cross-sectional area of ​​the bundle of the multiple (16 here) second tubes 22 in one connector unit 20 is greater than the cross-sectional area of ​​the first tube 21.

[0041] The connector group 23 is an assembly composed of a plurality of optical connectors 10. Here, the connector group 23 is composed of 16 optical connectors 10 (see FIG. 5A and FIG. 5B). However, the number of optical connectors 10 constituting the connector group 23 is not limited to 16. Here, the connector group 23 is composed of four sets of optical connectors 10 (a total of 16 optical connectors 10), with one set being four optical connectors 10 that have the same longitudinal position. The longitudinal positions of the optical connectors 10 in each set gradually differ. Specifically, the longitudinal positions of the optical connectors 10 in each set differ stepwise by approximately the length of one optical connector 10. If all the optical connectors 10 in the connector group 23 were arranged at the same longitudinal position, the overall cross-sectional area of ​​the connector group 23 would increase, making it difficult to accommodate the connector group 23 in the narrow accommodation space of the accommodation body 51. In contrast, in the present embodiment, the longitudinal positions of the optical connectors 10 in each set are gradually varied, thereby reducing the cross-sectional area of ​​the connector group 23 and making it easier to accommodate the connector group 23 in the narrow accommodation space of the accommodation body 51. Note that, in the present embodiment, one set includes four optical connectors 10, but this is not limited to this. For example, one set may include eight optical connectors 10, and the connector group 23 may be configured by two sets of optical connectors 10.

[0042] As described above, the housing structure of this embodiment includes an optical cable 1, a plurality of connector units 20 branched from the optical cable 1, and a housing body 51 housing the plurality of connector units 20. Each connector unit 20 has a first tube 21 through which a plurality of optical fibers branched from the optical cable are inserted, a plurality of second tubes 22 through which the optical fibers branched from the first tube 21 are respectively inserted, and a connector group 23 consisting of a plurality of optical connectors 10 (the same number as the second tubes 22) provided at the end of each second tube 22. Next, an example of the optical connector 10 will be described.

[0043] Fig. 6A is an explanatory diagram of the optical connector 10 of this embodiment. Fig. 6B is an explanatory diagram of a state in which the cylindrical member 18 of Fig. 6A has been removed. Fig. 6C is an explanatory diagram of a state in which the cylindrical member 18 and the second tube 22 of Fig. 6A have been removed. Fig. 7 is an exploded view of the optical connector 10 of this embodiment.

[0044] The optical connector 10 of this embodiment is a so-called MPO connector (F13 type multi-core optical fiber connector defined in JIS C 5982). The optical connector 10 of this embodiment has a ferrule 11, a pin clamp 12, a housing 13, a coupling 14, a spring 15, a spring push 16, and a fixing member 17. However, the configuration of the optical connector 10 is not limited to this, and it is sufficient that the optical connector 10 includes the ferrule 11, the housing 13, and the fixing member 17.

[0045] The ferrule 11 is a member that holds an end of the optical fiber 3. The ferrule 11 of this embodiment is a so-called MT ferrule (an F12 type multi-core optical fiber connector defined in JIS C 5981). The ferrule 11 has a plurality of fiber holes, and an optical fiber 3 is inserted and fixed in each of the fiber holes. A pin clamp 12 is disposed on the rear side of the ferrule 11. The ferrule 11 is pressed forward by a spring 15 via the pin clamp 12. A flange portion of the ferrule 11 comes into contact with a protrusion (not shown) formed on the inner wall surface of the housing 13, thereby preventing the ferrule 11, which is pressed forward, from slipping out.

[0046] The housing 13 is a member that accommodates the ferrule 11 in a retractable manner. The housing 13 accommodates the pin clamp 12, the spring 15, and the spring push 16 together with the ferrule 11. An engagement hole 13A is formed in the side surface of the housing 13. The engagement hole 13A is a hole for engagement with the spring push 16 (more specifically, the claw portion 161A).

[0047] The coupling 14 is a member provided on the outside of the housing 13. By sliding the coupling 14 rearward, the optical connector 10 can be removed from the adapter (not shown). The spring 15 is an elastic member that presses the ferrule 11. The spring 15 is disposed between the pin clamp 12 and the spring push 16 in a compressed and deformed state. The spring push 16 is a receiving portion (spring receiving member) that fixes the rear end of the spring 15 to the housing 13. The spring push 16 has a pair of arm portions 161 and a fitting portion 162. The arm portion 161 is a portion that is engaged with the housing 13. The spring 15 is disposed between the pair of arm portions 161. A claw portion 161A is formed at the end of the arm portion 161. The claw portion 161A engages with the engagement hole 13A of the housing 13, thereby fixing the spring push 16 to the housing 13. The fitting portion 162 is a portion that fixes the fixing member 17.

[0048] The fixing member 17 is a member for fixing the end of the second tube 22. The fixing member 17 has a fitting portion 17A and a tubular portion 171. The fitting portion 17A is a portion that fits with the fitting portion 162 of the spring push 16. The fitting portion 17A fits with the fitting portion 162 of the spring push 16, whereby the fixing member 17 is fixed to the housing 13. The tubular portion 171 is a tubular portion at the rear of the fixing member 17. In this embodiment, the tubular portion 171 is configured in a cylindrical shape. However, the tubular portion 171 may be in an elliptical shape or a rectangular tube shape. A through hole is formed in the fixing member 17 (and the tubular portion 171) along the front-rear direction, and the optical fiber 3 (here, two optical fiber tapes) can be inserted through this through hole.

[0049] In this embodiment, the tubular portion 171 has a protrusion 171A. The protrusion 171A is a portion (pin-shaped portion) protruding outward from the outer circumferential surface of the tubular portion 171. When the second tube 22 (braided tube) is placed over the tubular portion 171, the protrusion 171A can be inserted through the mesh of the second tube 22. As a result, the second tube 22 is caught by the tubular portion 171, so that the second tube 22 is less likely to come off the tubular portion 171, and the second tube 22 can be held to the optical connector 10. In addition, since the second tube 22 is less likely to come off the tubular portion 171, the protection of the optical fiber 3 extending from the rear side of the optical connector 10 can be maintained. In this embodiment, the second tube 22 can be held to the housing 13 with a simple configuration, so that the length of the optical connector 10 can be easily shortened. By shortening the length of the optical connector 10, the length of the connector group 23 can also be shortened, and as a result, the length L0 of the container 51 can also be shortened.

[0050] As shown in FIGS. 6A to 6C (and FIG. 7), the fixing member 17 of this embodiment further includes a tubular member 18. The tubular member 18 is a cylindrical member separate from the main body of the fixing member 17. By fitting the tubular member 18 into the tubular portion 171, the second tube 22 can be sandwiched between the outer circumferential surface of the tubular portion 171 and the inner circumferential surface of the tubular member 18. This makes it possible to prevent the second tube 22 from coming off the tubular portion 171. However, the second tube 22 may be fixed to the fixing member 17 without using the tubular member 18.

[0051] The configuration of the optical connector 10 is not limited to the above. However, the cross-sectional area of ​​the optical connector 10 in this embodiment is larger than the cross-sectional area of ​​the second tube 22.

[0052] <Regarding the arrangement of the connector group 23 of each connector unit 20> Fig. 8 is an explanatory diagram of the arrangement of the connector group 23 of this embodiment. Fig. 8 shows an arrangement of a plurality of connector units 20 of this embodiment.

[0053] As already described, in this embodiment, nine (nine units) of connector units 20 are accommodated in the accommodation space of the container 51. Therefore, in this embodiment, nine (nine groups) of connector groups 23 are accommodated in the accommodation space of the container 51. If the nine connector groups 23 were arranged at the same position in the longitudinal direction, it would be difficult to accommodate the connector groups 23 in the narrow accommodation space of the container 51 because the cross-sectional area of ​​the optical connector 10 is relatively large (larger than the cross-sectional areas of the first tube 21 and the second tube 22). Therefore, in this embodiment, the longitudinal positions of the connector groups 23 of each connector unit 20 are gradually made different. On the other hand, if the longitudinal positions of the connector groups 23 of each connector unit 20 are made different, the length (longitudinal dimension) of the container 51 may become large. In response to this, in this embodiment, in order to suppress the length of the container 51, an arrangement of the connector groups 23 as shown in FIG. 8 is adopted. Hereinafter, the arrangement of the connector groups 23 in this embodiment will be described.

[0054] 8, the shortest connector unit 20 among the nine connector units 20 is the first connector unit 20A. Here, the area occupied in the longitudinal direction by the connector group 23 of this first connector unit 20A is referred to as "area A." In this area A, not only the connector group 23 of the first connector unit 20A but also the eight first tubes 21 of the other eight connector units 20 are arranged.

[0055] 8, the connector group 23 of the first connector unit 20A and the first tubes 21 of the other eight connector units 20 are arranged, but the second tubes 22 of the other eight connector units 20 are not arranged. Therefore, the total cross-sectional area of ​​the structure occupying region A is the sum of the cross-sectional area of ​​the connector group 23 of the first connector unit 20A and the cross-sectional area of ​​the eight first tubes 21.

[0056] 9 is an explanatory diagram of a first comparative example. In the first comparative example, the connector unit 20 does not include a first tube 21, and the second tubes 22 attached to each optical connector 10 extend to the outlet portion 1A of the optical cable 1. As a result, in the first comparative example, the connector group 23 of the first connector unit 20A and many second tubes 22 of the other eight connector units 20 are arranged in the region A. Therefore, the total cross-sectional area of ​​the structure occupying the region A is the sum of the cross-sectional area of ​​the connector group 23 of the first connector unit 20A and the cross-sectional area of ​​the eight units of second tubes 22 (128 second tubes 22).

[0057] As already described, the total cross-sectional area of ​​the multiple (here, 16) second tubes 22 in a certain connector unit 20 is larger than the cross-sectional area of ​​the first tube 21. Therefore, as in the first comparative example of FIG. 9, when the second tubes 22 of other connector units 20 are present in the region A, the total cross-sectional area of ​​the structures occupying the region A increases (as a result, in the first comparative example, it becomes necessary to increase the thickness of the housing 51 to increase the housing space). In contrast, according to the present embodiment shown in FIG. 8, the first tubes 21 of eight connector units 20 other than the first connector unit 20A are arranged in the region A, so that the cross-sectional area of ​​the structures in the region A can be suppressed. As a result, in this embodiment, the diameter of the housing 51 (specifically, the housing tube 52) can be reduced.

[0058] In this embodiment, as shown in FIG. 8, the connector group 23 of the second connector unit 20B is disposed on the tip side of the connector group 23 of the first connector unit 20A to the extent that the second tube 22 of the second connector unit 20B (the connector unit 20 that is the second longest after the first connector unit 20A) does not exist in the region A. As a result, the first tube 21 of the second connector unit 20B exists in the region A. Furthermore, if the connector group 23 of the second connector unit 20B is disposed in this manner, the first tube 21 of the other connector unit 20 that is longer than the second connector unit 20B exists in the region A. Therefore, the connector group 23 of the second connector unit 20B is disposed on the tip side forward of the connector group 23 of the first connector unit 20A to the extent that the second tube 22 of the second connector unit 20B does not exist in the region A, so that the connector group 23 of the first connector unit 20A and the first tubes 21 of the other eight connector units 20 are disposed in the region A.

[0059] As with the first connector unit 20A, in the second connector unit 20B, only the first tubes 21 of the other connector units 20 (the third connector unit 20C to the ninth connector unit 20I) are present in the region occupied by the connector group 23 of the second connector unit 20B, and no second tubes 22 of the other connector units 20 are present. This makes it possible to reduce the cross-sectional area of ​​the structure in the region occupied by the connector group 23 of the second connector unit 20B. Similarly, with regard to the third connector unit 20C and the fourth connector unit 20D, only the first tube 21 of the other connector unit 20 is present in the region occupied by the connector group 23 of the connector unit 20, and the second tube 22 of the other connector unit 20 is not present. This makes it possible to reduce the cross-sectional area of ​​the structure in the region occupied by the connector group 23 of the third connector unit 20C and the fourth connector unit 20D.

[0060] Incidentally, as shown in FIG. 8, in the region A (the region occupied by the connector group 23 of the first connector unit 20A), nine connector units 20 (the first connector unit 20A to the ninth connector unit 20I) including the connector group 23 of the first connector unit 20A are present. In contrast, in the region occupied by the connector group 23 of a connector unit 20 other than the first connector unit 20A, at least the structure of the first connector unit 20A is absent, so the cross-sectional area of ​​the structure in the region is reduced. For example, in the region occupied by the connector group 23 of the second connector unit 20B, eight connector units 20 (the second connector unit 20B to the ninth connector unit 20I) are present, and since there is no structure of the first connector unit 20A, the cross-sectional area of ​​the structure is reduced compared to the region A. Also, the connector unit 20 in which the connector group 23 is disposed closer to the tip end has a smaller number of connector units 20 present in the region occupied by the connector group 23 of that connector unit 20, so the cross-sectional area of ​​the structure in the region is reduced more. For example, when comparing the area occupied by the connector group 23 of the second connector unit 20B with the area E occupied by the connector group 23 of the fifth connector unit 20E, the cross-sectional area of ​​the structure in the area occupied by the connector group 23 of the fifth connector unit 20E is smaller.

[0061] 8, in the connector unit 20 in which the connector group 23 is disposed at the tip end side, the second tube 22 of another connector unit 20 is allowed to be present in the region occupied by the connector group 23 of the connector unit 20. For example, the second tube 22 of the sixth connector unit 20F (the connector unit 20 that is the second longest after the fifth connector unit 20E) is present in the region E occupied by the connector group 23 of the fifth connector unit 20E. This makes it possible to narrow the longitudinal distance between the connector group 23 of the fifth connector unit 20E and the connector group 23 of the sixth connector unit 20F in this embodiment. This makes it possible to shorten the length L0 of the container 51 in this embodiment.

[0062] Similarly, in a connector unit 20 (for example, any of the sixth connector unit 20F to the eighth connector unit 20H) in which the connector group 23 is arranged further distal than the connector group 23 of the fifth connector unit 20E, the second tube 22 of another connector unit 20 (for example, the seventh connector unit 20G) is present in the region occupied by the connector group 23 of the connector unit 20 (for example, the sixth connector unit 20F). This makes it possible to narrow the longitudinal interval between the connector groups 23 arranged further distal than the connector group 23 of the fifth connector unit 20E, and to shorten the length L0 of the housing 51.

[0063] 10A and 10B are comparative explanatory diagrams of the arrangement of the connector group 23. Fig. 10A shows the arrangement of the connector group 23 of this embodiment. Fig. 10B shows the arrangement of the connector group 23 of a second comparative example.

[0064] In the second comparative example shown in Fig. 10B, in all connector units 20, the second tubes 22 of the other connector units 20 are not present in the region occupied by the connector group 23 in the longitudinal direction. In other words, in all connector units 20 except for the longest ninth connector unit 20I, the first tubes 21 of the other connector units 20 are present in the region occupied by the connector group 23 in the longitudinal direction. For this reason, in the second comparative example, it is necessary to widen the longitudinal spacing between the connector groups 23 in all connector units 20. As a result, the longitudinal spacing between the connector group 23 of the fifth connector unit 20E and the connector group 23 of the sixth connector unit 20F in the second comparative example is wider than that in the present embodiment shown in Fig. 10A. Similarly, in the second comparative example, even in a connector unit 20 (e.g., sixth connector unit 20F) in which the connector group 23 is disposed closer to the tip than the connector group 23 of the fifth connector unit 20E, the longitudinal distance between the connector group 23 of that connector unit 20 and the connector group 23 of the next longest connector unit 20 is wider than in this embodiment. As a result, the length L1 of the housing 51 in the second comparative example is longer than the length L0 of the housing 51 in this embodiment.

[0065] As described above, in the housing structure of this embodiment, the first tubes 21 of the connector units 20 other than the first connector unit 20A are present in the region A occupied in the longitudinal direction by the connector group 23 of the shortest first connector unit 20A. This allows the housing body 51 to be made thinner in this embodiment. Meanwhile, in at least one connector unit 20 (e.g., the fifth connector unit 20E) in which the connector group 23 is disposed closer to the tip than the connector group 23 of the first connector unit 20A, the second tube 22 of the connector unit 20 (e.g., the sixth connector unit 20F) that is the second longest after the connector unit 20 is present in the region (e.g., region E) occupied in the longitudinal direction by the connector group 23 of the connector unit 20. This allows not only the housing body 51 to be made thinner, but also the housing body 51 to be shortened.

[0066] In this embodiment, when a certain connector unit 20 is the Nth connector unit 20, the next longest connector unit 20 is the N+1th connector unit 20, and the second tube 22 of the N+1th connector unit 20 is present in an area occupied in the longitudinal direction by the connector group 23 of the Nth connector unit 20 (for example, when N=5), the longitudinal distance between the connector group 23 of the Nth connector unit 20 and the connector group 23 of the N+1th connector unit 20 is shorter than the longitudinal distance between the connector group 23 of the first connector unit 20A and the connector group 23 of the second connector unit 20B. This realizes a reduction in the length L0 of the container 51.

[0067] Furthermore, in this embodiment, the second tube 22 of another connector unit 20 (e.g., N+2 connector unit 20; seventh connector unit 20G) is present in an area occupied in the longitudinal direction by the connector group 23 of a connector unit 20 (e.g., N+1 connector unit 20; sixth connector unit 20F) whose connector group 23 is arranged on the tip side of the connector group 23 of the Nth connector unit 20 (e.g., N=5; fifth connector unit 20E). This makes it possible to narrow the longitudinal interval between the connector groups 23 arranged on the tip side of the connector group 23 of the Nth connector unit 20, and further shorten the length L0 of the housing 51. However, it is not necessary to narrow all the intervals between the connector groups 23 arranged on the tip side of the connector group 23 of the Nth connector unit 20.

[0068] <Method of manufacturing the optical cable 100 with a pulling end> Fig. 11 is a flow diagram of a method for manufacturing the optical cable with a towing end 100 of this embodiment. Figs. 12A to 12F are explanatory diagrams of the state of manufacturing the optical cable with a towing end 100 of this embodiment.

[0069] First, the worker prepares the terminal structure 50 of this embodiment (S101). Specifically, the worker prepares the braided tube 55 and the housing 51 (for example, the housing tube 52, the housing tube fixing portion, and the front member). The worker also prepares a heat shrink tube that constitutes the tube fixing portion 56. The worker inserts the heat shrink tube into the optical cable 1 in advance.

[0070] Next, the worker leads out the optical fiber 3 from the optical cable 1 (S102; see FIG. 12A). The worker also inserts each of the optical fibers branched from the optical cable into the first tube 21, and each of the optical fibers branched from the first tube 21 into the second tube 22 (S103). The worker cuts the optical fiber 3 (optical fiber tape) leading out from the optical cable 1 so that each of the completed connector units 20 has a predetermined length. The optical fiber 3 may be cut before being inserted into the first tube 21 and the second tube 22, or may be cut after being inserted into the first tube 21 and the second tube 22.

[0071] Next, the worker attaches the optical connector 10 to the end of the optical fiber 3 (optical fiber tape) inserted into the second tube 22 (S104; see FIG. 12B). The worker also fixes the end of the second tube 22 to the optical connector 10 (S105; see FIGS. 6A to 6C). The worker also fixes the opposite end of the second tube 22 to the first tube 21 (not shown). When the optical connectors 10 are fixed to the respective ends of all the second tubes 22, the assembly of the multiple connector units 20 is completed.

[0072] In this embodiment, when the completed connector units 20 are arranged in the longitudinal direction, the first tubes 21 of the connector units 20 other than the first connector unit 20A are present in the region A occupied in the longitudinal direction by the connector group 23 of the shortest first connector unit 20A. In at least one connector unit 20 (e.g., the fifth connector unit 20E) in which the connector group 23 is disposed on the distal end side of the connector group 23 of the first connector unit 20A, the second tube 22 of the second longest connector unit 20 (e.g., the sixth connector unit 20F) is present in the region (e.g., region E) occupied in the longitudinal direction by the connector group 23 of the connector unit 20. In order to arrange the connector units 20 in this manner, the worker cuts the optical fiber protruding from the optical cable to a predetermined length (see FIG. 12A).

[0073] After assembling the connector units 20, the worker assembles the housing 51 (S106; see FIG. 12C). Here, the worker attaches the housing tube fixing part to the optical cable, and assembles the housing 51 by attaching the housing tube and the front member while accommodating the multiple connector units 20. At this stage, the housing structure in which the multiple connector units 20 are accommodated in the housing 51 is completed as shown in FIG. 8. Also, if the terminal structure 50 has a structure as shown in FIG. 3, the manufacture of the optical cable with towing end 100 is completed at the stage of S105.

[0074] In this embodiment, after assembling the housing 51, the housing 51 is housed in the braided tube 55 (S107). At this time, as shown in Fig. 12D, the worker places the housing tube 52 inside the braided tube 55 by covering the front side of the housing 51 with the braided tube 55. Also, as shown in Fig. 12E, the worker places the end of the braided tube 55 on the outer periphery of the optical cable 1, and covers the end of the braided tube 55 with a heat shrink tube that has been inserted into the optical cable 1 in advance, thereby placing the end of the braided tube 55 between the optical cable 1 and the heat shrink tube. Finally, the worker heats the heat shrink tube to fix the end of the braided tube 55 to the optical cable 1. This completes the manufacture of the optical cable 100 with a towing end, as shown in FIG. 12F.

[0075] As described above, in the manufacturing method of this embodiment, the optical fibers branched from the optical cable are inserted into the first tube 21, the optical fibers branched from the first tube 21 are inserted into the second tube 22, and the optical connector 10 is provided at the end of the optical fiber inserted into the second tube 22 (S103, S104). As a result, a plurality of connector units 20 each having the first tube 21, the plurality of second tubes 22, and the connector group 23 consisting of the plurality of optical connectors 10 provided at the end of each of the second tubes 22 are branched from the optical cable to be produced. Also, in this embodiment, the housing structure (or the optical cable 100 with a pulling end) is manufactured by housing the plurality of connector units 20 in the housing 51. Then, in the manufacturing method of this embodiment, the plurality of first tubes 21 of the connector units 20 other than the first connector unit 20A are present in the region A occupied in the longitudinal direction by the connector group 23 of the shortest first connector unit 20A. As a result, in this embodiment, the housing 51 can be made thinner. Meanwhile, in at least one connector unit 20 (e.g., the fifth connector unit 20E) in which the connector group 23 is disposed closer to the tip end than the connector group 23 of the first connector unit 20A, the second tube 22 of the second longest connector unit 20 (e.g., the sixth connector unit 20F) is present in an area (e.g., area E) occupied in the longitudinal direction by the connector group 23 of the connector unit 20. This makes it possible not only to reduce the diameter of the container 51 but also to shorten the container 51.

[0076] ===Other embodiments=== The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0077] 1 Optical cable, 1A outlet, 2 Optical fiber unit, 3 Optical fiber, 4 Outer jacket, 5 Presser tape, 6 tension member, 7 rip cord, 10 Optical connector, 11 Ferrule, 11A Guide pin, 12 pin clamp, 13 housing, 13A engagement hole, 14 Coupling, 15 Spring, 16 Spring Push, 161 arm portion, 161A claw portion, 162 fitting portion, 17 fixing member, 17A fitting portion, 171 tubular portion, 171A protrusion portion, 18 cylindrical member, 20 Connector unit, 21 1st tube, 22 2nd tube, 23 connectors, 50 towing terminal structure, 50A towing section, 51 container, 52 container tube, 53 housing tube fixing portion, 54 front member, 55 braided tube, 56 tube fixing part, 100 Optical cable with towing end

Claims

1. an optical cable having a plurality of optical fibers; a plurality of connector units branched from the optical cable; a housing for housing a plurality of the connector units; Equipped with Each of the connector units comprises: a first tube through which a plurality of the optical fibers are inserted; a plurality of second tubes into which optical fibers branched from the first tube are inserted; a connector group consisting of a plurality of optical connectors provided at the end of each of the second tubes; having The connector groups of the respective connector units are located at different positions in a longitudinal direction, The shortest connector unit is a first connector unit, the next longest connector unit after the first connector unit is a second connector unit, a certain connector unit is an Nth connector unit, the next longest connector unit after the Nth connector unit is an N+1th connector unit, N is 2 or more, and N+1 is the number of connector units or less, a plurality of the first tubes of the connector units other than the first connector unit are present in an area occupied in the longitudinal direction by the connector group of the first connector unit, in at least one connector unit in which the connector group is disposed on the distal end side of the connector group of the first connector unit, the second tube of the connector unit which is the second longest after the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction, When the second tube of the (N+1) connector unit is present in an area occupied in the longitudinal direction by the connector group of the N connector unit, the longitudinal distance between the connector group of the N connector unit and the connector group of the (N+1) connector unit is shorter than the longitudinal distance between the connector group of the first connector unit and the connector group of the second connector unit. A containment structure comprising:

2. 2. The containment structure of claim 1, A storage structure characterized in that in a connector unit in which the connector group is arranged further towards the tip than the connector group of the Nth connector unit, the second tube of another connector unit is present in the area occupied in the longitudinal direction by the connector group of the connector unit.

3. 3. The storage structure according to claim 1 or 2, A storage structure, characterized in that a total cross-sectional area of ​​the plurality of second tubes in a given connector unit is larger than a cross-sectional area of ​​the first tube in the given connector unit.

4. an optical cable having a plurality of optical fibers; a plurality of connector units branched from the optical cable; a housing for housing a plurality of the connector units; Equipped with Each of the connector units comprises: a first tube through which a plurality of the optical fibers are inserted; a plurality of second tubes into which optical fibers branched from the first tube are inserted; a connector group consisting of a plurality of optical connectors provided at the end of each of the second tubes; having The connector groups of the respective connector units are located at different positions in a longitudinal direction, The shortest connector unit is a first connector unit, the next longest connector unit after the first connector unit is a second connector unit, a certain connector unit is an Nth connector unit, the next longest connector unit after the Nth connector unit is an N+1th connector unit, N is 2 or more, and N+1 is the number of connector units or less, a plurality of the first tubes of the connector units other than the first connector unit are present in an area occupied in the longitudinal direction by the connector group of the first connector unit, in at least one connector unit in which the connector group is disposed on the distal end side of the connector group of the first connector unit, the second tube of the connector unit which is the second longest after the connector unit is present in an area occupied by the connector group of the connector unit in the longitudinal direction, When the second tube of the (N+1) connector unit is present in an area occupied in the longitudinal direction by the connector group of the N connector unit, the longitudinal distance between the connector group of the N connector unit and the connector group of the (N+1) connector unit is shorter than the longitudinal distance between the connector group of the first connector unit and the connector group of the second connector unit.

1. An optical cable with a towing end.

5. 5. The optical cable with a towing end according to claim 4, Further comprising a braided tube that houses the housing; A traction portion is provided at an end of the braided tube, An optical cable with a pulling end, characterized in that an end of the braided tube opposite to the pulling portion is fixed to the optical cable.

6. Inserting a plurality of optical fibers branched from an optical cable into a first tube, inserting a plurality of optical fibers branched from the first tube into a second tube, and providing an optical connector at an end of the optical fiber inserted into the second tube, thereby creating a plurality of connector units branched from the optical cable, each of which has a first tube, a plurality of second tubes, and a connector group consisting of a plurality of optical connectors provided at an end of each of the second tubes; A plurality of the connector units are accommodated in a housing. A method for manufacturing a storage structure comprising the steps of: The shortest connector unit is a first connector unit, the next longest connector unit after the first connector unit is a second connector unit, a certain connector unit is an Nth connector unit, the next longest connector unit after the Nth connector unit is an N+1th connector unit, N is 2 or more, and N+1 is the number of connector units or less, a plurality of first tubes of connector units other than the first connector unit are present in a region occupied in a longitudinal direction by the connector group of the first connector unit; In at least one connector unit in which the connector group is disposed on the distal end side of the connector group of the first connector unit, the second tube of the connector unit that is the second longest after the connector unit is disposed in an area occupied by the connector group of the connector unit in the longitudinal direction, The second tube of the (N+1) connector unit is provided in an area occupied in the longitudinal direction by the connector group of the N connector unit, and the longitudinal distance between the connector group of the N connector unit and the connector group of the (N+1) connector unit is made shorter than the longitudinal distance between the connector group of the first connector unit and the connector group of the second connector unit. A method for manufacturing a storage structure comprising the steps of:

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