Title of the invention: a mesh tube, an optical fiber protection unit, an optical fiber protection method, and a method for manufacturing a mesh tube.
Technical field
[0001]
　The present invention relates to a mesh tube, an optical fiber protection unit, an optical fiber protection method, and a method for manufacturing a mesh tube.
Background technology
[0002]
　Patent Documents 1 to 4 describe an optical fiber unit in which a bundle material is wound around a bundle of a plurality of optical fibers. In addition, Patent Documents 3 and 4 describe a method of manufacturing an optical fiber unit by winding a bundle material around a bundle of a plurality of optical fibers.
[0003]
　Further, Patent Documents 5 to 7 describe various tubes. Patent Document 5 describes a protective tube that covers and protects the outer periphery of the optical fiber. Patent Document 6 describes that a plastic wire or a metal wire is knitted to form a stretchable tubular net to protect the wiring. Patent Document 7 describes that an electric wire is protected by a net tube whose diameter increases when it is shrunk.
Prior art literature
Patent documents
[0004]
Patent Document 1: International Publication WO2015 / 053146
Patent Document 2: Japanese Patent Application Laid-Open No. 2011-169939
Patent Document 3: Japanese Patent Application Laid-Open No. 2013-97320
Patent Document 4: Japanese Patent Application Laid-Open No. 2018-049081
Patent Document 5: Japanese Patent Application Laid-Open No. 2017-215438
Patent Document 6: Jitsukaisho 63-49356
Japanese Patent Document 7: Japanese Patent Application Laid-Open No. 2002-10441
Outline of the invention
Problems to be solved by the invention
[0005]
　The bundle materials described in Patent Documents 1 to 4 are wound around the outer periphery of a bundle of optical fibers in a manufacturing factory in order to bundle a plurality of optical fibers. Therefore, the bundle materials described in Patent Documents 1 to 4 do not protect the optical fiber and do not allow the optical fiber to pass through. Further, it is not assumed that the bundle materials described in Patent Documents 1 to 4 are attached to the outer periphery of the optical fiber bundle at the time of laying the optical fiber at the laying site (note that the patent is applied to the outer periphery of the optical fiber bundle when the optical fiber is laid. It is difficult to attach the bundled materials described in Documents 1 to 4 at the laying site).
[0006]
　Further, in the case of the protective tube described in Patent Document 5 and the spiral tube described in the prior art of Patent Document 6, it takes time and effort to insert the optical fiber. In the case of the braided tube (tube formed by knitting a wire rod) described in Patent Document 6 and Patent Document 7, since the amount of expansion and contraction in the longitudinal direction is small, there is a problem that it takes time and effort to insert the optical fiber in this case as well. Occurs. In addition, when an optical fiber is inserted into a braided tube whose diameter changes during expansion and contraction, the diameter becomes smaller when the braided tube is extended in the longitudinal direction, so that the optical fiber inserted inside is compressed, resulting in light. There is also the problem of increasing the transmission loss of the fiber.
[0007]
　An object of the present invention is to provide a novel protective tube capable of inserting an optical fiber inside when laying an optical fiber, having a large amount of expansion and contraction in the longitudinal direction, and suppressing the diameter from becoming thin during extension. ..
Means to solve problems
[0008]
　The main invention for achieving the above object is a mesh-like tube in which an opening is formed in a mesh-like shape and a plurality of optical fibers are inserted therein.
[0009]
　Other features of the present invention will be clarified by the description of the specification and drawings described later.
Effect of the invention
[0010]
　According to the present invention, the optical fiber can be protected by inserting a plurality of optical fibers into the mesh-like tube when laying the optical fiber. Further, since the opening is formed in a mesh shape, the amount of expansion and contraction in the longitudinal direction is large, and it is possible to prevent the diameter from becoming small during expansion.
A brief description of the drawing
[0011]
FIG. 1A is an explanatory diagram of an optical fiber unit 3 of the present embodiment. FIG. 1B is an explanatory view of the optical fiber unit 3 in a state where the mesh-like tube 10 is folded.
FIG. 2A is a developed view for explaining the shape of the mesh-like tube 10. FIG. 2B is an enlarged perspective view of the mesh-like tube 10 shown in FIG. 2A.
FIG. 3A is a cross-sectional view of the first wire rod 11 (or the second wire rod 12) of the present embodiment.
FIG. 4A is a developed view for explaining another shape of the mesh tube 10. FIG. 4B is an enlarged perspective view of the mesh-like tube 10 shown in FIG. 4A.
5A and 5B are development views for explaining yet another shape of the mesh tube 10.
FIG. 6A is an explanatory diagram of the shape of a braided tube as a comparative example. FIG. 6B is an enlarged explanatory view of the vicinity of the mesh of the braided tube as a comparative example.
7A and 7B are explanatory views of the state before and after expansion and contraction in the vicinity of the opening 10A (mesh) of the mesh-like tube 10 of the present embodiment.
FIG. 8 is an explanatory diagram of the protection unit 20.
9A-9D are explanatory views of a manufacturing method of the protection unit 20.
10A to 10E are explanatory views of a method of laying an optical fiber 5 using the protection unit 20.
11A to 11C are explanatory views of another laying method of the optical fiber 5 using the protection unit 20.
FIG. 12 is an explanatory diagram of a protection unit 20 of an improved example.
FIG. 13 is an explanatory view of the inside of the rack 40.
FIG. 14 is an exploded view of the branch member 50.
FIG. 15 is an explanatory view of a manufacturing apparatus 70 for a mesh-like tube 10.
FIG. 16 is an explanatory diagram of a mesh ratio.
FIG. 17 is a table showing the evaluation of the first embodiment.
FIG. 18 is a table showing a second embodiment.
FIG. 19 is an explanatory view of a pitch P and an inner diameter D.
FIG. 20 is a table showing a third embodiment.
FIG. 21 is a table showing a fourth embodiment.
FIG. 22A is an explanatory diagram of a method for measuring flexural rigidity. FIG. 22B is an explanatory diagram of a load-deflection diagram.
Mode for carrying out the invention
[0012]
　At least the following matters will be clarified from the description of the specification and drawings described later.
[0013]
　An opening is formed in a mesh shape, and a mesh tube through which a plurality of optical fibers are inserted becomes clear. According to such a mesh-like tube, the optical fiber can be protected by inserting a plurality of optical fibers into the mesh-like tube at the time of laying the optical fiber. Further, the mesh-like tube includes a peripheral edge portion forming the opening and a branch portion formed at the boundary of three or more of the openings and extending three or more of the peripheral edges. It is restrained by the branch portion and can be bent. As a result, the amount of expansion and contraction in the longitudinal direction is large, and it is possible to prevent the diameter from becoming smaller during expansion and contraction.
[0014]
　　It is desirable that the peripheral edge portion is bent so that the peripheral portion is folded in the longitudinal direction. This makes it possible to provide a mesh-like tube that is largely contracted in the longitudinal direction.
[0015]
　It is desirable that the bent portion of the peripheral edge portion is plastically deformed and the peripheral edge portion is held in a bent shape. As a result, the mesh-like tube can have a shape-retaining property in a bent state.
[0016]
　The mesh-like tube has a plurality of first wires arranged spirally in a predetermined direction and a plurality of second wires arranged in a direction different from the first wire, and the first wire or the above. It is desirable that the peripheral edge portion is formed by the second wire rod, and the branch portion is formed by the joint portion where the intersection of the first wire rod and the second wire rod is joined. Thereby, the mesh-like tube can be easily manufactured.
[0017]
　It is desirable that the intersections of the first wire and the second wire are fusion-bonded. Thereby, the mesh-like tube can be easily manufactured.
[0018]
　It is desirable that two or more of the branch portions are present on the cross section in which the branch portions are present. As a result, it is possible to prevent the diameter from becoming smaller during elongation. Further, it is desirable that three or more of the branch portions are present on the cross section in which the branch portions are present. As a result, it is possible to maintain a polygonal space having a plurality of branch portions as vertices on the cross section, so that it is possible to suppress pressure on the optical fibers arranged in the space.
[0019]
　When the area occupied by the opening when the mesh-like tube is unfolded is S1 and the area occupied by the peripheral edge is S2, it is desirable that the value of S1 / (S1 + S2) is 0.555 or less. As a result, it is possible to prevent the optical fiber inserted through the mesh-like tube from being caught in the peripheral member.
[0020]
　When the length of the mesh-like tube before shrinking in the longitudinal direction is L0 and the length of the mesh-like tube after shrinking in the longitudinal direction is L1, it is desirable that L0 / L1 is 0.13 or less. .. This makes it possible to provide a mesh-like tube that can be greatly contracted in the longitudinal direction.
[0021]
　It is desirable that the optical fiber can be inserted from the end of the mesh tube. As a result, when laying the optical fiber, a plurality of optical fibers can be inserted through the insertion port of the mesh-like tube.
[0022]
　The mesh-like tube is provided with a mesh-like tube in which an opening is formed in a mesh shape and a plurality of optical fibers are inserted therein, and a tubular member which is inserted into the mesh-like tube and allows a plurality of optical fibers to be inserted therein. Has a peripheral edge portion forming the opening and a branch portion formed at the boundary of three or more of the openings and extending three or more of the peripheral edges, the peripheral edge portion being the branch portion. An optical fiber protection unit characterized by being constrained and bendable becomes apparent. According to such an optical fiber protection unit, the work of inserting the optical fiber through the mesh-like tube becomes easy.
[0023]
　It is desirable that the mesh-like tube is arranged on the outer periphery of the tubular member in a state where the peripheral edge of the opening is bent and folded in the longitudinal direction. This facilitates the work of inserting the optical fiber through the mesh tube.
[0024]
　It is desirable that the end portion of the mesh-like tube is pulled out from the tubular member so that the mesh-like tube in a folded state can be extended in the longitudinal direction. This facilitates the work of inserting the optical fiber through the mesh tube.
[0025]
　It is desirable that the opening at at least one end of the tubular member is widened. This facilitates the work of inserting the bundle of optical fibers from the end of the tubular member.
[0026]
　It is desirable that the outer diameter of the end having a wide opening is larger than the inner diameter of the reticulated tube in the folded state. As a result, it is possible to prevent one end of the mesh-like tube from coming off from the tubular member.
[0027]
　A mesh-like tube having openings formed in a mesh shape, and a peripheral portion forming the opening and a branch portion formed at the boundary of three or more openings and extending three or more peripheral portions. To prepare a mesh-like tube in which the peripheral portion is restrained by the branch portion and is bendable, and a plurality of optical fibers are inserted from the end portion of the end portion of the mesh-like tube. An optical fiber protection method characterized by inserting the plurality of optical fibers into the mesh-like tube will be clarified. According to such an optical fiber protection method, the optical fiber can be protected by inserting a plurality of optical fibers into the mesh-like tube at the time of laying the optical fiber.
[0028]
　The mesh-like tube is prepared by bending the peripheral edge portion and folded in the longitudinal direction, and a plurality of the optical fibers are inserted from the end portion of the mesh-like tube in the folded state and folded. It is desirable that the plurality of optical fibers are inserted into the mesh-like tube of the above, and that the plurality of optical fibers are inserted into the stretched mesh-like tube by extending the mesh-like tube. .. This facilitates the work of inserting the optical fiber through the mesh tube.
[0029]
　To prepare an optical fiber protection unit including the mesh-like tube having the peripheral edge bent and folded in the longitudinal direction and a tubular member inserted through the mesh-like tube, and inserting the optical fiber into the tubular member. By doing so, a plurality of the optical fibers can be inserted from the end of the folded mesh tube, and the plurality of optical fibers can be inserted into the folded mesh tube. desirable. This facilitates the work of inserting the optical fiber through the mesh tube.
[0030]
　The mesh-like tube has a plurality of first wire rods arranged spirally in a predetermined direction and a plurality of second wire rods arranged in a direction different from the first wire rod, and the first wire rod and the said wire rod. A unit composed of a plurality of optical fibers in which the intersections with the second wire are joined, the pitch of the intersections in the longitudinal direction is P (mm), the inner diameter of the mesh tube is D (mm), and the plurality of optical fibers are formed. When the diameter of is Y (mm), it is desirable that 0.6 ≦ D / Y ≦ 1.2 and 6.0 (mm) ≦ P × D / Y ≦ 20.0 (mm). As a result, it is possible to improve performance such as wire passage workability of the mesh-like tube.
[0031]
　An opening is formed in a mesh shape, and there is a mesh-like tube through which a plurality of optical fibers are inserted. The optical fiber is provided with a branch portion having an extended portion, and the peripheral portion is restrained by the branch portion to form a bendable mesh-like tube, and the end portion of the mesh-like tube is formed with the optical fiber. A method for manufacturing a mesh-like tube, which is characterized by forming an insertion port into which an optical fiber is inserted, becomes clear. According to such a manufacturing method, it is possible to manufacture a mesh-like tube capable of protecting the optical fiber by inserting a plurality of optical fibers at the time of laying the optical fiber. In addition, it is possible to manufacture a mesh-like tube having a large amount of expansion and contraction in the longitudinal direction and capable of suppressing the diameter from becoming thin during expansion.
[0032]
　It is desirable to bend the peripheral edge and fold the mesh tube in the longitudinal direction. This makes it possible to manufacture a mesh-like tube that is largely contractible in the longitudinal direction.
[0033]
　Supplying a plurality of first wires to the heating unit while twisting in a predetermined direction, supplying a plurality of second wires while twisting in a direction opposite to that of the first wire, and supplying the heating unit with the heating unit. By fusing the intersection of the first wire and the second wire, the peripheral portion is formed by the first wire or the second wire, and the intersection of the first wire and the second wire is formed. It is desirable to form the mesh-like tube in which the branch portion is formed by the joint portion obtained by joining the two. Thereby, the mesh-like tube can be easily manufactured.
[0034]
　=== Embodiment ===
　
　FIG. 1A is an explanatory diagram of the optical fiber unit 3 of the present embodiment. FIG. 1A also shows an enlarged cross-sectional view of the AA cross section. FIG. 1B is an explanatory view of the optical fiber unit 3 in a state where the mesh-like tube 10 is folded.
[0035]
　The optical fiber unit 3 has a plurality of optical fibers 5 and a mesh-like tube 10. A plurality of optical fibers 5 are inserted through the mesh-like tube 10. The optical fiber is protected by inserting a plurality of optical fibers into the mesh-like tube. The plurality of optical fibers 5 of the present embodiment are configured by bundling a plurality of intermittently connected optical fiber tapes. However, the plurality of optical fibers 5 may be composed of one intermittently connected optical fiber tape, or may be configured by bundling a plurality of single-core optical fibers 5. In the present embodiment, as shown in FIG. 1B, the mesh-like tube 10 is configured to be foldable in the longitudinal direction by bending the peripheral edge portion 10B of the opening 10A. In the present embodiment, as will be described later, the length of the mesh-like tube 10 after being contracted in the longitudinal direction is 10% or less of the length of the mesh-like tube 10 in the initial state (extended state) before contraction. It is possible to.
[0036]
　Insertions into which a plurality of optical fibers 5 can be inserted are formed at the ends 10X on both sides of the mesh-like tube 10. As will be described later, in the mesh-like tube 10 of the present embodiment, it is possible to insert a plurality of optical fibers 5 from the end portion 10X (insertion port) and insert the optical fibers 5 into the inside. In the following description, one end 10X of the mesh tube 10 may be referred to as a "first end" and the other end 10X may be referred to as a "second end".
[0037]
　FIG. 2A is a developed view for explaining the shape of the mesh-like tube 10. FIG. 2A shows the mesh-like tube 10 on the cylindrical coordinate system, assuming that the non-bent mesh-like tube 10 is virtually arranged on the cylindrical surface. The horizontal axis in the figure indicates the position in the longitudinal direction. The vertical axis indicates the angle from the reference position (0 degree), and indicates the position in the circumferential direction on the cylindrical surface. 2B is an enlarged perspective view of the mesh-like tube 10 shown in FIG. 2A.
[0038]
　The mesh-like tube 10 is a tubular member in which a large number of openings 10A (mesh) are formed in a mesh shape. A mesh is formed in the mesh tube 10 by forming a large number of openings 10A. The opening 10A (mesh) is surrounded by at least two peripheral edges 10B, and constitutes a hole penetrating in the radial direction of the mesh tube 10.
[0039]
　The peripheral edge portion 10B is a linear (including band-shaped and string-shaped) portion surrounding the opening 10A. A peripheral edge portion 10B exists between the opening portion 10A and the opening portion 10A. The peripheral edge portion 10B may be referred to as a "strand". A branch portion 10C is formed at the boundary of three or more openings 10A. Three or more peripheral edges 10B extend from the branch portion 10C. In the case of the mesh-like tube 10 shown in FIG. 2A, the branch portion 10C is formed at the boundary of the four openings 10A, and the four peripheral portions 10B extend from the branch portion 10C. The branch portion 10C may be referred to as a "bridge".
[0040]
　In the present embodiment, a plurality of first wire rods 11 spirally formed in a predetermined direction (S direction) and a plurality of second wire rods spirally formed in a direction opposite to the first wire rod 11 (Z direction). A mesh tube 10 is formed by 12 and the like. In the present embodiment, the mesh-like tube 10 is formed by the four first wire rods 11 and the four second wire rods 12, but the number of the first wire rod 11 and the second wire rod 12 is limited to this. It's not a thing. The peripheral edge portion 10B of the present embodiment is composed of the first wire rod 11 or the second wire rod 12. Further, the branch portion 10C is formed by the intersection of the first wire rod 11 and the second wire rod 12. In the present embodiment, the intersections of the first wire rod 11 and the second wire rod 12 are joined (that is, the branch portion 10C of the present embodiment is the joint portion between the first wire rod 11 and the second wire rod 12). .. In the present embodiment, the intersections of the first wire rod 11 and the second wire rod 12 are fusion-bonded.
[0041]
　In the present embodiment, as shown in FIG. 2B, the first wire rod 11 and the second wire rod 12 are overlapped in a joined state at the branch portion 10C. That is, in the present embodiment, the branch portion 10C has a two-layer structure of the first wire rod 11 and the second wire rod 12 joined, and the peripheral portion 10B excluding the branch portion 10C is the first wire rod 11 or the second wire rod 11 or the second wire rod 12. It has higher strength than the one-layer structure of the wire rod 12. Therefore, in the present embodiment, the peripheral edge portion 10B excluding the branch portion 10C is more easily bent than the branch portion 10C.
[0042]
　Further, in the present embodiment, as shown in FIG. 2B, the first wire rod 11 and the second wire rod 12 intersect with each other so that the first wire rod 11 is arranged on the second wire rod 12 at the branch portion 10C. There is. That is, in the present embodiment, the first wire rod 11 and the second wire rod 12 are not woven. In this way, since one wire of the first wire 11 and the second wire 12 is only arranged on the other wire, when the first wire 11 and the second wire 12 are woven (the first wire 11 and the second wire). It is possible to easily manufacture the mesh-like tube 10 as compared with the case where the wire rods 12 intersect alternately (described later).
[0043]
　FIG. 3A is a cross-sectional view of the first wire rod 11 (or the second wire rod 12) of the present embodiment. The first wire rod 11 (or the second wire rod 12) has a plurality of core portions 13 and a covering portion 14. The core portion 13 is a fibrous member (core material) extending in the longitudinal direction (longitudinal direction of the first wire rod 11). The covering portion 14 is a covering member that covers the outer periphery of the plurality of core portions 13. The melting point of the covering portion 14 is lower than the melting point of the core portion 13. At the time of manufacturing the first wire rod 11 (or the second wire rod 12) of the present embodiment, a large number of fibers in which the core material (core portion 13) is coated with the coating portion 14 are focused, and the temperature is equal to or higher than the melting point of the coating portion 14 and the core is formed. A large number of fibers are fused and integrated while being stretched at a temperature lower than the melting point of the portion 13, to form the first wire rod 11 (or the second wire rod 12). Further, when the mesh-like tube 10 is manufactured, it is heated at a temperature equal to or higher than the melting point of the covering portion 14 and lower than the melting point of the core portion 13, so that both are heated at the intersection of the first wire rod 11 and the second wire rod 12. It will be fused. Since the melting point of the core portion 13 is higher than the melting point of the coating portion 14, the core portion 13 can be made difficult to melt even when the coating portion 14 is heated above the melting point. It is possible to maintain the strength of the wire rod 12.
[0044]
　The first wire rod 11 and the second wire rod 12 may be made of a single material instead of a composite material of the high melting point material (core portion 13) and the low melting point material (coating portion 14) as shown in FIG. 3A. good.　
　3B and 3C are cross-sectional views of the first wire rod 11 (or the second wire rod 12) having a different structure. The first wire rod 11 shown in FIG. 3B is configured by fusing and integrating fibers made of an uncoated core material. The first wire rod 11 shown in FIG. 3C is not fused with fibrous members, but is formed in a film shape. The first wire rod 11 (or the second wire rod 12) may be composed of a single material as described above. In the following description, the structure shown in FIG. 3A may be referred to as a “double layer monofilament”, the structure shown in FIG. 3B may be referred to as a “single layer monofilament”, and the structure shown in FIG. 3C may be referred to as a “film”.
[0045]
　Further, as will be described later, it is desirable that the first wire rod 11 (or the second wire rod 12) has plasticity. As a result, the mesh-like tube 10 can be configured so that the peripheral edge portion 10B has a shape-retaining property in a bent state. For example, if the first wire rod 11 and the second wire rod 12 are made of a two-layer monofilament in which the core portion 13 is polyester and the coating portion 14 is polypropylene, the peripheral edge portion 10B has shape retention in a bent state. , It is possible to form a mesh-like tube 10. However, if the mesh-like tube 10 can be configured so that the peripheral edge portion 10B has shape retention in a bent state, the material of the first wire rod 11 (and the second wire rod 12) is not limited to this. Absent. For example, the core portion 13 may be made of a material other than polyester, or the covering portion 14 may be made of a material other than polypropylene, and the first wire rod 11 (and the second wire rod 12) may be formed of other organic materials. Further, the first wire rod 11 (and the second wire rod 12) may not be composed of the two-layer monofilament, or may be composed of a material other than the organic material.
[0046]
　In the present embodiment, the peripheral edge portion 10B is formed in a tape shape (strip shape, flat shape) as shown in FIGS. 3A to 3C. As a result, in the present embodiment, the peripheral edge portion 10B is easily bent so that a mountain fold line or a valley fold line is formed on the tape surface. As will be described later, if the peripheral edge portion 10B is composed of a member in which fibers are fused and integrated as shown in FIGS. 3A and 3B, it is compared with the case where the peripheral portion 10B is formed in the form of a film shown in FIG. 3C. As a result, the mesh-like tube 10 can be contracted more greatly.
[0047]
　FIG. 4A is a developed view for explaining another shape of the mesh-like tube 10. FIG. 4B is an enlarged perspective view of the mesh-like tube 10 shown in FIG. 4A. While the above-mentioned mesh-like tube 10 is formed by joining the first wire rod 11 and the second wire rod 12 (see FIGS. 2A and 2B), the mesh-like tube 10 has a large number of openings 10A. It is configured as one formed tubular member. In this way, the intersections of the two linear peripheral edges 10B may not be joined (the branch 10C may not be the joint).
[0048]
　5A and 5B are development views for explaining still another shape of the mesh tube 10. In the above-mentioned mesh-like tube 10, two linear peripheral edges 10B intersect at the branch portion 10C (see FIGS. 2B and 4B), and four peripheral edges 10B extend from the branch portion 10C. On the other hand, in the mesh-like tube 10 shown in FIG. 5A, the linear peripheral edges 10B do not intersect, and three peripheral edges 10B extend in a T shape from the branch portion 10C. In this way, the two linear peripheral edges 10B do not have to intersect. Further, the mesh-like tube 10 shown in FIG. 5B has a plurality of first wire rods 11 spirally formed in a predetermined direction (S direction) and a plurality of second wire rods arranged (vertically attached) along the longitudinal direction. A mesh tube 10 is formed by 12 and the like. In this way, when the intersections of the two wires are joined to form the mesh tube 10, it is not necessary to arrange all the wires in a spiral shape. When the mesh-like tube 10 has a wire rod parallel to the longitudinal direction as in the mesh-like tube 10 shown in FIG. 5B, it is possible to prevent the inner diameter of the mesh-like tube 10 from becoming excessively thin when the mesh-like tube 10 is extended. can do.
[0049]
　The shape of the opening 10A does not have to be square or rectangular, and may be rhombic or parallel quadrilateral. Further, the shape of the opening 10A does not have to be a quadrangular shape, and may be another polygonal shape. Further, the shape of the opening 10A is not limited to a polygonal shape, and may be a circular shape or an elliptical shape. Further, the opening 10A may be formed in a slit shape having no predetermined area.
[0050]
　FIG. 6A is an explanatory diagram of the shape of a braided tube as a comparative example. FIG. 6B is an enlarged explanatory view of the vicinity of the mesh of the braided tube as a comparative example.
[0051]
　The braided tube as a comparative example is constructed by knitting a wire rod into a tube shape. Since the intersections of the wires are not joined, the angle at which the wires intersect is variable. In the case of such a braided tube, the wire rods are expanded and contracted in the longitudinal direction by changing the intersection angle between the wire rods without bending them. Therefore, the amount of expansion and contraction of the braided tube in the longitudinal direction is relatively small. Further, in the case of a braided tube, the diameter of the tube changes because the crossing angle between the wires is changed during expansion and contraction. Therefore, when the braided tube is extended, the inner diameter of the braided tube becomes small, which may press the optical fiber 5 inserted therein, which may increase the transmission loss of the optical fiber 5.
[0052]
　7A and 7B are explanatory views of the state before and after expansion and contraction in the vicinity of the opening 10A (mesh) of the mesh-like tube 10 of the present embodiment.
[0053]
　In the present embodiment, when the mesh-like tube 10 contracts in the longitudinal direction (see FIG. 1B), the peripheral edge portion 10B of the opening 10A is bent and folded in the longitudinal direction as shown in FIG. 7B. This is because in the present embodiment, the peripheral edge portion 10B is constrained by the branch portion 10C, and the intersection angle between the wire rods is not variable as in the comparative example (in the present embodiment, the first wire rod 11 and the first wire rod 11 and the first wire rod). This is because the two wire rods 12 are joined at the intersection). The bent peripheral edge portion 10B not only displaces in the cylindrical peripheral surface of the mesh-like tube 10 before deformation, but also displaces in the radial direction. As a result, in the present embodiment, the amount of contraction in the longitudinal direction is significantly larger than that of the braided tube of the comparative example. As will be described later, in the present embodiment, the length of the mesh-like tube 10 after being contracted in the longitudinal direction is 10% or less of the length of the mesh-like tube 10 in the initial state (extended state) before contraction. (On the other hand, with the contraction mechanism of the braided tube of the comparative example shown in FIG. 6B, it is impossible to contract the length to 1/10 of the initial state).
[0054]
　Further, in the present embodiment, the peripheral edge portion 10B is restrained by the branch portion 10C, and the crossing angle between the wires is not variable as in the comparative example. Therefore, when the mesh-like tube 10 is extended, the mesh-like tube is formed. It is possible to prevent the inner diameter of 10 from becoming excessively thin. Therefore, when the folded mesh-like tube 10 is extended, it is possible to suppress the pressure on the optical fiber 5 inserted therein, and it is possible to suppress the transmission loss of the optical fiber 5.
[0055]
　In order to prevent the inner diameter of the mesh-like tube 10 from becoming excessively thin when the mesh-like tube 10 is extended, the branch portion 10C that restrains the peripheral edge portion 10B is formed on the cross section of the mesh-like tube 10 (branch portion 10C). It is desirable that two or more are present on the cross section of the mesh-like tube 10 at the site where Further, when three or more branch portions 10C for restraining the peripheral edge portion 10B are present on the cross section of the mesh-like tube 10, a polygonal space having a plurality of branch portions 10C as vertices can be maintained on the cross section. This is particularly desirable because it can suppress pressure on the optical fiber 5 arranged in the space. In the present embodiment, since the four branch portions 10C are present on the cross section of the mesh-like tube 10, it is possible to prevent the inner diameter of the mesh-like tube 10 from becoming excessively thin, and the optical fiber inserted therein. It is possible to suppress the pressure on 5.
[0056]
　Further, in the present embodiment, since the peripheral edge portion 10B is formed in a tape shape (strip shape or flat shape) (see FIG. 3A), the peripheral edge portion 10B is formed so that a mountain fold line or a valley fold line is formed on the tape surface. Is easy to bend, so that the bent peripheral edge portion 10B is easily displaced in the radial direction, and the amount of contraction in the longitudinal direction can be made very large. In addition, in the present embodiment, the peripheral edge portion 10B (one-layer structure) excluding the branch portion 10C has lower strength than the branch portion 10C (two-layer structure), so that when the mesh-like tube 10 is folded in the longitudinal direction. In addition, it is possible to induce the peripheral edge portion 10B to bend so that a mountain fold line or a valley fold line is formed on the tape surface (so that the tape surface is displaced in the radial direction).
[0057]
　In the present embodiment, the peripheral edge portion 10B has plasticity, the peripheral edge portion 10B is plastically deformed in a bent state, and the peripheral edge portion 10B is held in a bent shape. That is, in the present embodiment, the peripheral edge portion 10B has a shape-retaining property in a bent state. Thereby, in the present embodiment, the shape of the mesh-like tube 10 can be maintained in a state where the mesh-like tube 10 is contracted in the longitudinal direction as shown in FIG. 1B. Further, in the present embodiment, it is also possible to extend the peripheral portion 10B in a bent state. Thereby, in the present embodiment, as shown in FIG. 1A, the mesh-like tube 10 can be extended in the longitudinal direction from the state in which the mesh-like tube 10 is contracted in the longitudinal direction (see FIG. 1B). In this embodiment, the work of inserting the optical fiber 5 into the mesh-like tube 10 is facilitated by utilizing the property of being able to extend the peripheral portion 10B in the bent state.
[0058]
　
　FIG. 8 is an explanatory diagram of the protection unit 20.
[0059]
　The protection unit 20 is a member for inserting the optical fiber 5 into the mesh-like tube 10. The protection unit 20 has the above-mentioned mesh-like tube 10 and a tubular member 22 (pipe). The tubular member 22 is a hollow cylindrical member through which a bundle of a plurality of optical fibers 5 can be passed. In the following description, one end of the tubular member 22 may be referred to as a "first end 22A" and the other end may be referred to as a "second end 22B". A mesh-like tube 10 folded in the longitudinal direction is arranged on the outer circumference of the tubular member 22. The tubular member 22 is inserted through a folded mesh tube 10. That is, the protection unit 20 has a double-cylinder structure in which the tubular member 22 is arranged inside and the mesh-like tube 10 folded on the outer circumference is arranged. By arranging the tubular member 22 inside the mesh-like tube 10, the end portion 5A of the optical fiber 5 does not get caught in the mesh-like tube 10 when the optical fiber 5 is inserted into the mesh-like tube 10. In the present embodiment, since a bundle of a plurality of optical fibers 5 is inserted into the folded mesh-like tube 10 (described later), it is particularly advantageous to arrange the tubular member 22 inside the mesh-like tube 10.
[0060]
　The mesh-like tube 10 is folded in the longitudinal direction so as to be shorter than the longitudinal length of the tubular member 22. Further, the first end 22A and the second end 22B of the tubular member 22 extend from the ends 10A on both sides of the folded mesh tube 10. Since the first end 22A and the second end 22B of the tubular member 22 extend outward from the mesh tube 10 to the left and right, the work of inserting the optical fiber 5 into the tubular member 22 becomes easy (described later). However, one end (for example, the first end 22A) of the tubular member 22 is extended outward from the mesh tube 10, and the other end (for example, the second end 22B) is inside the mesh tube 10. You may arrange it. In the stretched state, the mesh-like tube 10 has a length several times longer than that of the tubular member 22. As will be described later, the length of the mesh-like tube 10 after being contracted in the longitudinal direction is 10% or less of the length of the mesh-like tube 10 in the initial state (extended state) before contraction.
[0061]
　The end portion 10X of the folded mesh tube 10 may or may not be fixed to the tubular member 22. It is also possible that one end 10X is fixed to the tubular member 22 and the other end 10X is not fixed to the tubular member 22. Further, the end portion 10X of the mesh-like tube 10 may be temporarily fixed to the tubular member 22 so as to be detached from the tubular member 22.
[0062]
　9A to 9D are explanatory views of a manufacturing method of the protection unit 20.
[0063]
　First, as shown in FIG. 9A, a mesh-like tube 10 and a tubular member 22 are prepared. Next, as shown in FIG. 9B, the tubular member 22 is inserted into the mesh-like tube 10, and the end portion 10X of the mesh-like tube 10 (the end portion 10X on the side where the tubular member 22 is inserted) is fixed to the tubular member 22. (Including temporary fixing). Next, as shown in FIG. 9C, the mesh-like tube 10 is folded in the longitudinal direction by pulling the mesh-like tube 10 toward the fixed end of the mesh-like tube 10 (the mesh-like tube 10 is contracted in the longitudinal direction). .. As a result, the folded mesh-like tube 10 can be arranged on the outer circumference of the tubular member 22. Then, as shown in FIG. 9D, the mesh-like tube 10 is folded and contracted in the longitudinal direction until the opposite end portion 10X of the mesh-like tube 10 is located on the outer circumference of the tubular member 22. As a result, the protection unit 20 shown in FIG. 8 can be manufactured.
[0064]
　10A to 10E are explanatory views of a method of laying the optical fiber 5 using the protection unit 20. It should be noted that the figure is also an explanatory view of the protection method of the optical fiber 5 using the mesh-like tube 10.
[0065]
　First, the operator prepares the protection unit 20 and the optical fiber 5 to be protected. Here, a plurality of optical fibers 5 (bundles of optical fibers 5) are ejected from the optical cable 1. As shown in FIG. 10A, the operator inserts the end portion 5A of the bundle of the optical fibers 5 into the first end 22A of the tubular member 22. At this time, if the end portion 10X of the mesh-like tube 10 is temporarily fixed to the tubular member 22, the end portion 10X of the mesh-like tube 10 detached from the tubular member 22 may close the opening of the first end 22A. Since this is prevented, the work of inserting the optical fiber 5 into the tubular member 22 becomes easy.
[0066]
　Next, the operator slides the protection unit 20 toward the opening portion (peeling edge) of the optical cable 1 while inserting the optical fiber 5 through the tubular member 22 of the protection unit 20, and protects the protection unit 20 as shown in FIG. 10B. The first end 22A of the tubular member 22 of the unit 20 is brought into the vicinity of the opening portion (peeling edge) of the optical cable 1. By inserting the optical fiber 5 through the tubular member 22, the optical fiber 5 can be inserted inside the folded mesh-like tube 10, so that the optical fiber 5 (and the end portion 5A of the optical fiber 5) has a mesh shape. It does not have to be caught in the tube 10. Therefore, the work of inserting the optical fiber 5 into the mesh-like tube 10 is easier than the case where the optical fiber 5 is directly inserted into the mesh-like tube 10. Further, in the present embodiment, since the end portion 10X of the mesh-like tube 10 is located on the outer periphery of the tubular member 22, the end portion 10X of the mesh-like tube 10 detached from the tubular member 22 opens the opening of the second end 22B. Since the blockage is prevented, the work of pulling out the optical fiber 5 from the side of the second end 22B of the tubular member 22 is also easy.
[0067]
　By the way, in the present embodiment, since the mesh-like tube 10 is folded in the longitudinal direction by bending the peripheral edge portion 10B of the opening 10A (see FIG. 7B), the amount of contraction of the mesh-like tube 10 in the longitudinal direction is extremely large. Large (see FIGS. 1B and 9D). Therefore, in the present embodiment, the length of the mesh-like tube 10 and the length of the protection unit 20 are sufficiently shorter than the length of the optical fiber 5 to be protected. As a result, as shown in FIG. 10A, immediately after inserting the end portion 5A of the optical fiber 5 into the first end 22A of the tubular member 22, the end portion 5A of the optical fiber 5 starts from the second end 22B of the tubular member 22. It will come out. Therefore, when the protection unit 20 is slid toward the opening portion (when peeled off) of the optical cable 1 (when the state shown in FIG. 10A is changed to the state shown in FIG. 10B), the operator moves from the second end 22B of the tubular member 22. The optical fiber 5 (the optical fiber 5 on the end 5A side) that has come out can be held by hand, and the mesh tube 10 and the tubular member 22 can be moved while pulling the optical fiber 5. Thereby, in the present embodiment, it is easy to move the mesh-like tube 10 and the tubular member 22 to the root of the optical fiber 5 (in this case, the opening portion (peeling edge) of the optical cable 1). If the optical fiber is inserted into a protective tube (for example, a long silicon tube) of the same length as the optical fiber to be protected, the optical fiber does not easily come out from the outlet of the protective tube. The work of covering the protective tube to the root of the fiber 5 (the work of inserting the optical fiber through the protective tube) is difficult. On the other hand, in the present embodiment, by using the mesh-like tube 10 having an extremely large amount of contraction in the longitudinal direction, it is sufficient to insert the optical fiber 5 into the short mesh-like tube 10 or the tubular member 22, so that the work can be performed. The sex can be improved.
[0068]
　Next, the operator removes the end portion 10X of the mesh-like tube 10 that has been temporarily fixed from the tubular member 22, and as shown in FIG. 10C, attaches the end portion 10X to the outside of the first end 22A of the tubular member 22. It is pulled out, and the end portion 10X is covered with the opening portion (peeling; outer cover) of the optical cable 1 and fixed. The method of fixing the end portion 10X of the mesh-like tube 10 to the optical cable 1 may be fixed with an adhesive tape or fixed with a jig.
[0069]
　After fixing the end 10X of the mesh tube 10 to the optical cable 1, the operator slides the tubular member 22 toward the end 5A of the optical fiber 5 as shown in FIG. 10D. At this time, since the optical fiber 5 passes through the inside of the tubular member 22 and the end portion 10X of the mesh-like tube 10 is fixed to the outside (in this case, the outlet portion of the optical cable 1), the tubular member 22 is the first. The mesh-like tube 10 is pulled out from one end 22A. As a result, the folded mesh-like tube 10 is extended, and as shown in FIG. 1A, the bundle of optical fibers 5 is inserted into the extended portion of the mesh-like tube 10.
[0070]
　Finally, as shown in FIG. 10E, the operator slides the tubular member 22 to the outside of the end 5A of the optical fiber 5 to remove the tubular member 22 from the bundle of optical fibers 5. Here, the end portion 10X of the mesh-like tube 10 that has been temporarily fixed is separated from the tubular member 22, and the tubular member 22 and the mesh-like tube 10 are separated from each other. However, the end portion 10X of the mesh-like tube 10 and the tubular member 22 may remain fixed. In this case, the optical fiber 5 may remain inserted through the tubular member 22 without the tubular member 22 being detached from the optical fiber 5.
[0071]
　11A to 11C are explanatory views of another laying method of the optical fiber 5 using the protection unit 20. It should be noted that the figure is also an explanatory view of the protection method of the optical fiber 5 using the mesh-like tube 10.
[0072]
　First, the worker prepares the protection unit 20. Here, the left end portion 10X (first end; fixed end) of the mesh-like tube 10 of the protection unit 20 in the drawing is fixed (for example, adhered) to the tubular member 22. On the other hand, the right end portion 10X (second end; free end) of the folded mesh-like tube 10 in the drawing is not fixed to the tubular member 22. Therefore, the right end portion 10X (second end; free end) of the mesh-like tube 10 in the drawing can be slidably moved on the outside of the tubular member 22 in the longitudinal direction, and can also be removed from the tubular member 22. is there. On the other hand, since the left end portion 10X of the mesh-like tube 10 in the drawing is fixed to the tubular member 22, it is prevented from coming off from the tubular member 22. Thereby, it is possible to prevent the end portion 10X of the mesh-like tube 10 from blocking the first end 22A of the tubular member 22 (the end portion of the tubular member 22 on the side where the fixed end (first end) of the mesh-like tube 10 is located). .. However, the ends 10X on both sides of the mesh-like tube 10 may be free ends without being fixed to the tubular member 22.
[0073]
　As shown in FIG. 11A, the operator pulls a bundle of optical fibers 5 from the first end 22A of the tubular member 22 (the end of the tubular member 22 on the side where the fixed end (first end) of the mesh tube 10 is located). insert. At this time, since the end portion 10X of the mesh-like tube 10 is fixed, the end portion 10X is the tubular on the side where the first end 22A of the tubular member 22 has an opening (the fixed end (first end) of the mesh-like tube 10). Since the end portion of the member 22 is prevented from being closed, the work of inserting the optical fiber 5 into the tubular member 22 is easy.
[0074]
　Next, as shown in FIG. 11B, the operator starts from the second end 22B on the opposite side of the tubular member 22 (the end of the tubular member 22 on the side where the free end (second end) of the mesh tube 10 is located). Pull out the end portion 5X of the optical fiber 5. At this time, by inserting the optical fiber 5 through the tubular member 22, the optical fiber 5 can be inserted inside the folded mesh-like tube 10, so that the end portion 5A of the optical fiber 5 is inserted into the mesh-like tube 10. You don't have to get caught. Therefore, the work of inserting the optical fiber 5 into the mesh-like tube 10 is easier than the case where the optical fiber 5 is directly inserted into the mesh-like tube 10. Further, in the present embodiment, since the free end (second end) of the mesh-like tube 10 is located on the outer periphery of the tubular member 22, the end portion 10X of the mesh-like tube 10 is the second end 22B of the tubular member 22. Since the opening is not closed, the work of pulling out the optical fiber 5 from the tubular member 22 is easy.
[0075]
　Next, as shown in FIG. 11C, the operator removes the end portion 10X (second end; free end) of the mesh-like tube 10 to the outside of the tubular member 22, and emits light at the end portion 10X of the mesh-like tube 10. Covers the bundle of fibers 5. Then, the operator picks the optical fiber 5 through the end portion 10X of the mesh-like tube 10, and as shown in FIG. 11D, the second end 22B of the tubular member 22 (the free end (second end) of the mesh-like tube 10). ) Is pulled out together with the optical fiber 5 and the mesh tube 10 from the end portion of the tubular member 22 on the side with the). When 10X (second end; free end) of the mesh-like tube 10 is pulled out from the second end 22B of the tubular member 22, the mesh-like tube 10 in the folded state extends, and as shown in FIG. 1A, the mesh-like tube A bundle of optical fibers 5 is inserted inside the extended portion of 10. After that, the operator repeats the work of picking the optical fiber 5 through the mesh tube 10 and pulling out the optical fiber 5 and the mesh tube 10 together. As a result, as shown in FIG. 1A, the mesh-like tube 10 through which the bundle of the optical fibers 5 is inserted can be pulled out from the second end 22B of the tubular member 22. Since the mesh-like tube 10 is made of a flexible material, if the operator picks the mesh-like tube 10 outside the second end 22B of the tubular member 22, the optical fiber 5 together with the mesh-like tube 10 Since the optical fiber 5 can be picked up, the work of pulling out the optical fiber 5 and the mesh tube 10 together is easy.
[0076]
　FIG. 12 is an explanatory diagram of the protection unit 20 of the improved example. The tubular member 22 of the protection unit 20 of the improved example has a trumpet shape at the first end 22A (the end of the tubular member 22 on the side where the fixed end of the mesh tube 10 is located). That is, the tubular member 22 of the protection unit 20 of the improved example has an opening that becomes wider toward the end. This facilitates the work of inserting the bundle of the optical fibers 5 from the first end 22A of the tubular member 22. According to this improved example, since the end portion of the optical fiber 5 is less likely to hit the edge (edge ​​of the opening) of the tubular member 22, the effect of suppressing damage to the optical fiber 5 can also be obtained.
[0077]
　In the case of the protection unit 20 of the improved example, it is desirable that the outer diameter of the first end 22A having a wide opening is larger than the inner diameter of the mesh-like tube 10 in the folded state. As a result, it is possible to prevent the end portion 10X of the mesh-like tube 10 from coming off from the tubular member 22. Therefore, in the case of the protection unit 20 of the improved example, both ends of the mesh tube 10 may be free ends without fixing the end 10X of the mesh tube 10 to the tubular member 22.
[0078]
　
　FIG. 13 is an explanatory view of the inside of the rack 40. A terminal device 41 and a branch member 50 are arranged in the rack 40. The rack 40 is a shelf on which the terminal device 41 and the like are placed, and includes a frame and a shelf board. The terminal device 41 includes a plurality of optical modules 42 arranged side by side, and each optical module 42 includes a plurality of connector connection ports 44 (optical adapters) arranged vertically.
[0079]
　The branch member 50 is a member (branch unit) that branches a bundle of a plurality of bundles of optical fibers 5 from the optical cable 1. The optical cable 1 is a cable including a large number of optical fibers 5, and has a plurality of bundles composed of the plurality of optical fibers 5.
[0080]
　The bundles of the optical fibers 5 branched from the branch member 50 are arranged (wired) between the branch member 50 and the terminal device 41, respectively. Normally, in the wiring path between the branch member 50 and the terminal device 41, a bundle of optical fibers 5 is inserted through a protective tube which is a long elastic tube (silicon tube) to protect the optical fiber 5. (On the other hand, in the present embodiment, the mesh-like tube 10 protects the bundle of the optical fibers 5). An optical connector is attached to the end of the optical fiber 5, and each optical connector is connected to a connector connection port 44 of the terminal device 41.
[0081]
　FIG. 14 is an exploded view of the branch member 50. The branch member 50 has a main body portion 51 and a lid portion 57.
[0082]
　The main body 51 is a portion that holds a bundle of the optical cable 1 and the branched optical fiber 5. The main body 51 has a first fixing portion 52, a second fixing portion 53, and an accommodating portion 54.
[0083]
　The first fixing portion 52 is a portion (cable fixing portion) for fixing the end portion of the optical cable 1. The first fixing portion 52 has a support portion 521 and a fastening member 522. The support portion 521 is a member that supports the optical cable 1. Here, the support portion 521 is composed of a sawtooth plate having teeth that bite into the outer cover of the optical cable 1, but the support portion 521 does not have to have teeth. Further, the support portion 521 may be integrally formed with the main body portion 51. The fastening member 522 is a member that fixes the optical cable 1 to and from the support portion 521.
[0084]
　The second fixing portion 53 is a portion for fixing the protective tube through which the bundle of the optical fibers 5 is inserted (however, in the present embodiment, the second fixing portion 53 is a protective unit instead of the long protective tube. 20 tubular members 22 are fixed). The second fixing portion 53 has a grip portion 531. The grip portion 531 has a plurality of (here, four) recesses 531A. Three protective tubes (an elastic tube (silicon tube) through which an optical fiber 5 is inserted; a tubular member 22 in this embodiment) can be inserted into each recess 531A. Here, the grip portion 531 is composed of a grip plate having teeth that bite into the protective tube, but the grip portion 531 may be integrally formed with the main body portion 51. When the protective tube is inserted into the recess 531A of the grip portion 531, the grip portion 531 bites into the protective tube and the protective tube is gripped by the grip portion 531.
[0085]
　The accommodating portion 54 is a portion accommodating a branch portion (outlet portion) of the optical cable 1. By filling the accommodating portion 54 with an adhesive, the outlet portion of the optical cable 1 can be adhesively fixed to the branch member 50. After attaching the lid portion 57 to the main body portion 51, the adhesive is filled into the accommodating portion 54 from the injection port 57A of the lid portion 57. In order to prevent the adhesive from leaking, an upstream stopper 541 is provided on the upstream side (optical cable 1 side) of the accommodating portion 54, and a downstream stopper 542 is provided on the downstream side of the accommodating portion 54. ..　
[0086]
　In the present embodiment, the optical cable 1 has 12 bundles of optical fibers 5. In the present embodiment, after the optical cable 1 is squeezed out, the bundles of the respective optical fibers 5 are inserted into the mesh tube 10 by using the protection unit 20 as shown in FIGS. 11A to 11C. In the present embodiment, when the bundle of the optical fibers 5 is inserted into the mesh tube 10 by using the protection unit 20, the tubular member 22 is arranged on the upstream side, and the optical fiber unit 3 (plurality of optical fiber units 3) is arranged on the downstream side from the tubular member 22. A bundle of optical fibers 5 and a mesh-like tube 10) through which the bundle of optical fibers 5 is inserted will be arranged. FIG. 14 shows twelve protective units 20 in which a bundle of optical fibers 5 is inserted through a mesh tube 10.
[0087]
　In the present embodiment, instead of the protective tube (silicon tube), the tubular member 22 of the protective unit 20 can be fixed to the second fixing portion 53. Three tubular members 22 into which a bundle of optical fibers 5 is inserted are inserted into each recess 531A of the grip portion 531. When the tubular member 22 is inserted into the recess 531A of the grip portion 531, the grip portion 531 bites into the tubular member 22, and the tubular member 22 is gripped by the grip portion 531.
[0088]
　When the protection unit 20 of the present embodiment is used, the work of inserting the optical fiber 5 (the work of protecting the optical fiber 5) is different from the case of inserting the optical fiber 5 into the protective tube which is a long elastic tube. It's easy. Further, according to the present embodiment, the tubular member 22 of the protection unit 20 can be directly gripped by the second fixing portion 53 of the branch member 50, which is convenient. Further, when the grip portion 531 of the second fixing portion 53 grips the optical fiber unit 3, the tubular member 22 is interposed between the grip portion 531 and the optical fiber 5, so that the optical fiber 5 is damaged by the grip portion 531. Can be suppressed.
[0089]
　
　FIG. 15 is an explanatory view of a manufacturing apparatus 70 for the mesh-like tube 10. The manufacturing apparatus 70 includes a first supply unit 71, a second supply unit 72, a guide unit 73, and a heating unit 74. Further, when manufacturing the mesh-like tube 10 folded in the longitudinal direction, it is desirable to further provide the tube shrinking portion 75.
[0090]
　The first supply unit 71 is a device that supplies the first wire rod 11 to the heating unit 74. The first supply unit 71 has a plurality of first supply sources 71A and a first rotation unit 71B. The first supply source 71A is a supply source for supplying the first wire rod 11. The first rotating unit 71B is a rotating member that rotates a plurality of first supply sources 71A in a predetermined direction. In other words, the first rotating portion 71B is a member that twists the first wire rod 11 in a predetermined direction. A plurality of first supply sources 71A are arranged at equal intervals (equal angles) in the rotation direction in the first rotation unit 71B.
[0091]
　The second supply unit 72 is a device that supplies the second wire rod 12 to the heating unit 74. The second supply unit 72 has a plurality of second supply sources 72A and a second rotation unit 72B. The second supply source 72A is a supply source for supplying the second wire rod 12. The second supply source 72A has almost the same configuration as the first supply source 71A. The second rotating portion 72B is a rotating member that rotates a plurality of second supply sources 72A in a direction opposite to the rotating direction of the first rotating portion 71B. In other words, the second rotating portion 72B is a member that twists the second wire rod 12 in the direction opposite to the twisting direction of the first wire rod 11. A plurality of second supply sources 72A are arranged at equal intervals (equal angles) in the rotation direction in the second rotation unit 72B.
[0092]
　The second supply unit 72 is arranged on the downstream side of the first supply unit 71, and the second supply unit 72 is arranged inside the plurality of first wire rods 11 supplied from the first supply unit 71. Thereby, the intersection of the first wire rod 11 and the second wire rod 12 can be formed so that the first wire rod 11 is arranged on the second wire rod 12. In the present embodiment, only one wire of the first wire 11 and the second wire 12 is arranged on the other wire, so that when the first wire 11 and the second wire 12 are knitted (the first wire 11 and the second wire). Compared with the case where the wire rods 12 are alternately crossed), the first supply unit 71 and the second supply unit 72 can have a simpler configuration.
[0093]
　The guide portion 73 is a member that guides the first wire rod 11 and the second wire rod 12 in the longitudinal direction while winding the first wire rod 11 and the second wire rod 12 around. The guide portion 73 has a columnar outer peripheral surface. The guide portion 73 may be a cylindrical (or rod-shaped) member or a cylindrical member. The first wire rod 11 supplied from the first supply unit 71 is spirally wound around the outer peripheral surface of the guide portion 73 in a predetermined direction (S direction), and the second wire rod 12 supplied from the second supply unit 72. Will be spirally wound in the opposite direction (Z direction). Further, the first wire rod 11 and the second wire rod 12 wound around the outer peripheral surface of the guide portion 73 move in the axial direction along the cylindrical outer peripheral surface.
[0094]
　The heating unit 74 is a member that heats the first wire rod 11 and the second wire rod 12. When the heating unit 74 heats the first wire rod 11 and the second wire rod 12, the intersections of the first wire rod 11 and the second wire rod 12 are fused and joined. The heating portion 74 has a hollow cylindrical shape, and a heating surface is formed on the inner surface thereof. A guide portion 73 is inserted inside the hollow heating portion 74. A gap is formed between the inner surface of the heating portion 74 and the outer peripheral surface of the guide portion 73, and the first wire rod 11 and the second wire rod 12 wound around the outer peripheral surface of the guide portion 73 pass through the gap. It will be. In the present embodiment, as shown in FIG. 3A, the first wire rod 11 and the second wire rod 12 are composed of the core portion 13 and the covering portion 14, and the melting point of the core portion 13 is higher than the melting point of the coating portion 14. Therefore, it is possible to maintain the strength of the first wire rod 11 and the second wire rod 12 after the fusion splicing. The mesh-like tube 10 is manufactured by the heating portion 74 fusing and joining the intersections of the first wire rod 11 and the second wire rod 12.
[0095]
　In the present embodiment, the inner diameter of the mesh tube 10 can be set by the outer diameter of the guide portion 73. Further, the number of the first wire rod 11 and the second wire rod 12 (the number of the first supply source 71A and the second supply source 72A), the rotation speed of the first rotating portion 71B and the second rotating portion 72B, and the mesh tube 10 The pitch in the longitudinal direction of the branch portion 10C can be set by the moving speed in the longitudinal direction of the branch portion 10C.
[0096]
　In the present embodiment, the first wire rod 11 and the second wire rod 12 are wound around the outer peripheral surface of the guide portion 73, and an intersection of the first wire rod 11 and the second wire rod 12 is formed on the outer peripheral surface of the guide portion 73. The intersections will be fused and connected by the heating unit 74. Since the intersection of the first wire rod 11 and the second wire rod 12 is a superposition of the two wires, the intersection is closer to the inner peripheral surface (heating surface) of the heating portion 74 than the portion that is not the intersection, and the heating portion. 74 facilitates heating and fusion connection. In addition, in order to promote the fusion connection between the first wire rod 11 and the second wire rod 12, even if the intersection of the first wire rod 11 and the second wire rod 12 comes into contact with the inner peripheral surface (heating surface) of the heating portion 74. good. Further, in order to crimp the first wire rod 11 and the second wire rod 12, the gap between the outer peripheral surface of the guide portion 73 and the inner peripheral surface of the heating portion 74 is larger than the thickness of the first wire rod 11 (or the second wire rod 12). It may be set to be wider than the thickness of the first wire rod 11 and the second wire rod 12 overlapped with each other.
[0097]
　Further, in the present embodiment, the first wire rod 11 and the second wire rod 12 are formed in a tape shape (strip shape, flat shape) as shown in FIG. 3A. Then, in the present embodiment, the tape surfaces of the first wire rod 11 and the second wire rod 12 are made to face the columnar outer peripheral surface of the guide portion 73, and the first wire rod 11 and the second wire rod 12 are attached to the guide portion 73. It will be wrapped around. As a result, the tape surfaces of the first wire rod 11 and the second wire rod 12 are joined to each other, so that the contact area at the intersection of the first wire rod 11 and the second wire rod 12 can be secured. The branch portion 10C can be sufficiently restrained (as a result, the intersection angle between the wires is not variable as in the comparative example, so that when the mesh tube 10 is extended, the inner diameter of the mesh tube 10 becomes excessive. It can be suppressed from becoming thin). Further, in the present embodiment, since the peripheral portion 10B of the mesh-like tube 10 is not twisted, it is possible to suppress the pressure on the optical fiber 5 inserted therein, and it is possible to suppress the transmission loss of the optical fiber 5.
[0098]
　The tube contracting portion 75 is a member that folds the mesh-like tube 10 in the longitudinal direction and contracts it in the longitudinal direction. The tube contraction portion 75 is a columnar (or rod-shaped) member through which the mesh-like tube 10 is inserted. The tube shrinking portion 75 has a columnar outer peripheral surface. The tube contraction portion 75 may be a cylindrical (or rod-shaped) member or a cylindrical member. The mesh-like tube 10 moves in the axial direction along the outer peripheral surface of the tube shrinking portion 75. The supply speed of the mesh-like tube 10 to the tube shrinkage portion 75 is faster than the discharge speed of the mesh-like tube 10 discharged from the tube shrinkage portion 75. Therefore, the mesh-like tube 10 supplied to the tube shrinking portion 75 contracts in the axial direction on the tube shrinking portion 75, and is discharged from the tube shrinking portion 75 in a state of being folded in the longitudinal direction. When the mesh-like tube 10 contracts axially on the tube contraction portion 75, the peripheral edge portion 10B of the mesh-like tube 10 is bent from the state shown in FIG. 7A as shown in FIG. 7B, and the mesh-like tube 10 is bent. It will be folded in the longitudinal direction. It is desirable that the outer diameter of the tube contracted portion 75 is slightly smaller than the outer diameter of the guide portion 73 so that the peripheral portion 10B of the mesh-like tube 10 is easily bent as shown in FIG. 7B.
[0099]
　A tubular member 22 is arranged on the downstream side of the tube contraction portion 75 (not shown). Then, the mesh-like tube 10 (the mesh-like tube 10 folded in the longitudinal direction) discharged from the tube contraction portion 75 is supplied to the tubular member 22 and has a predetermined length (length shorter than the tubular member 22). The mesh tube 10 is cut at. The end portion 10X (cut end) of the cut mesh-like tube 10 serves as an insertion port into which a plurality of optical fibers 5 can be inserted. The end portion 10X of the cut mesh-like tube 10 may or may not be fixed (including temporary fixing) to the tubular member 22. As a result, the above-mentioned protection unit 20 is formed.
[0100]
　The tube contraction portion 75 may also serve as the tubular member 22. In this case, after the mesh-like tube 10 contracts axially on the tube contraction portion 75 and is folded in the longitudinal direction, the tube contraction portion 75 is cut together with the mesh-like tube 10 at a predetermined length, and the cut tube contraction occurs. The portion 75 becomes the tubular member 22 of the protection unit 20.
[0101]
　 As
　the first embodiment, a plurality of types of mesh-like tubes 10 having different mesh ratios are provided by changing the number of the first wire rod 11 and the second wire rod 12 of the mesh-like tube 10 and the spiral pitch. Created. The inner diameter (inner dimension) of the mesh-like tube 10 is about 5.3 mm, and 288 optical fibers 5 (24 12-core intermittently connected optical fiber tapes) are inserted into the mesh-like tube 10 for evaluation. went.
[0102]
　FIG. 16 is an explanatory diagram of the mesh ratio. FIG. 16 is a developed view of the mesh-like tube 10 similar to FIG. 2A. The hatched portion in the figure is a portion occupied by the peripheral edge portion 10B (first wire rod 11 or second wire rod 12) on the developing surface (on the virtual cylindrical surface of the mesh-like tube 10). The portion without hatching in the figure is a portion occupied by the opening 10A (mesh) on the developing surface (on the virtual cylindrical surface of the mesh-like tube 10). Here, the mesh ratio is the ratio of the area occupied by the opening 10A on the developing surface to the total area of ​​the mesh tube on the developing surface (the sum of the area occupied by the opening 10A and the area occupied by the peripheral edge 10B). means. That is, when the area occupied by the opening 10A on the developing surface is S1 and the area occupied by the peripheral edge 10B on the developing surface is S2, the mesh ratio R (%) is as follows.
　R (%) = S1 / (S1 + S2) x 100
[0103]
　The method for measuring the area S1 and the area S2 is as follows. First, four test pieces are sampled at equal intervals from a mesh-like tube 10 having a predetermined length. Here, a 3 m mesh-like tube 10 is prepared, and four 5 cm test pieces including both ends of the mesh-like tube 10 are sampled at intervals of about 1 m. Next, the sampled test piece is developed as shown in FIG. 16, and the developed test piece is sandwiched between transparent acrylic plates. Then, the test piece is photographed through the acrylic plate to acquire image data, the area of ​​the opening 10A on the image data and the area of ​​the peripheral edge 10B on the image data are specified, respectively, and the area S1 and the area S2 are measured. To do. Here, image data is acquired using a digital microscope (VHX-6000 manufactured by KEYENCE CORPORATION) for photographing the test piece. The pitch P and the inner diameter D are also measured based on the image data obtained by photographing the test piece in the same manner (described later: see FIG. 19).
[0104]
　The work of actually attaching the mesh-like tube 10 through which the bundle of the optical fibers 5 is inserted to the closure is performed, and the optical fiber 5 (the optical fiber tape inserted through the mesh-like tube 10) or the mesh-like tube 10 is configured at the time of this attachment work. The evaluation was performed according to whether or not the peripheral edge portion 10B (first wire rod 11 or second wire rod 12) was caught in the peripheral member. When there was no catch, it was evaluated as "○ (good)", and when there was a catch, it was evaluated as "× (bad)".
[0105]
　FIG. 17 is a table showing the evaluation of the first embodiment. As shown in the figure, the smaller the mesh ratio, the less likely it is that the peripheral edge portion 10B constituting the mesh-like tube 10 is caught by the peripheral member. Further, when the mesh ratio was 43.6% or less, the catch could be eliminated. Therefore, it is desirable that the mesh ratio of the mesh tube 10 is 43.6% or less. That is, when the area occupied by the opening 10A on the developing surface is S1 and the area occupied by the peripheral edge portion 10B on the developing surface is S2, it is desirable that the value of S1 / (S1 + S2) is 0.436 or less. Further, as described later, when the mesh ratio was 55.5% or less, the catching could be eliminated. Therefore, it is desirable that the mesh ratio of the mesh tube 10 is 55.5% or less. That is, when the area occupied by the opening 10A on the developing surface is S1 and the area occupied by the peripheral edge portion 10B on the developing surface is S2, it is desirable that the value of S1 / (S1 + S2) is 0.555 or less.
[0106]
　
　FIG. 18 is a table showing the second embodiment.
[0107]
　As a second embodiment, a plurality of types of mesh-like tubes 10 having different numbers of optical fibers 5, the number of first wire rods 11 and second wire rods 12, inner diameter D of the mesh-like tube 10, pitch P, unit diameter Y, and the like are different. It was created. The cross-sectional shapes of the first wire rod 11 and the second wire rod 12 are 2 mm in width and 0.1 mm in thickness. Evaluation was performed by inserting a bundle of 72 to 288 optical fibers 5 into a unit by bundling a plurality of 12-core intermittently connected optical fiber tapes through a mesh tube 10.
[0108]
　FIG. 19 is an explanatory diagram of the pitch P and the inner diameter D.
[0109]
　When the number of the first wire rod 11 (or the second wire rod 12) is s and the spiral pitch for one circumference of the first wire rod 11 is L (mm) as shown in the figure, the pitch P (mm) is P. = L / s. Further, as shown in the figure, when the angle of the intersection of the first wire rod 11 and the second wire rod 12 (the size of the angle opened in the longitudinal direction) is θ, the inner diameter D (mm; the diameter of the inner dimension). Is calculated as follows.
　D = L × tan (θ / 2) / π
[0110]
　The unit diameter Y (mm) is the diameter of the unit (bundle of optical fibers 5) to be inserted into the mesh tube 10. When the total cross-sectional area of ​​the component (for example, the optical fiber 5) of the unit to be inserted through the mesh tube 10 is S (mm 2 ), the unit diameter Y (mm) is calculated by the following equation.
　Y = 1.46 x √S
[0111]
　In the evaluation of "wire passage workability", the workability when the optical fiber 5 was passed through the mesh tube 10 was confirmed. Then, the case where the optical fiber 5 can be easily passed is evaluated as "○ (good)", and the case where the optical fiber 5 is caught in the mesh tube 10 is evaluated as "Δ (possible)" or "× (defective)". evaluated.
[0112]
　Further, in the evaluation of "tightening or popping out", when the mesh-like tube 10 is stretched together with the optical fiber 5, whether or not the optical fiber 5 is tightened by the mesh-like tube 10 and the light from the opening 10A of the mesh-like tube 10 are evaluated. It was confirmed whether or not the fiber 5 had popped out. Then, when neither tightening nor popping occurred, it was evaluated as "○ (good)", and when tightening or popping occurred, it was evaluated as "x (bad)".
[0113]
　Further, in the evaluation of "maneuverability", it was confirmed that the mesh-like tube 10 was easy to handle with the optical fiber 5 inserted. Then, when the mesh-like tube 10 through which the optical fiber 5 is inserted can be easily routed, it is evaluated as "○ (good)", and there is a gap between the mesh-like tube 10 and the optical fiber 5, and the mesh-like tube When the optical fiber 5 moves inside the 10, it is evaluated as "Δ (possible)", and when there is a possibility that the optical fiber 5 protruding from the opening 10A of the mesh-like tube 10 is caught by an obstacle, it is evaluated as "Δ (possible)". × (impossible) ”was evaluated.
[0114]
　In the "comprehensive evaluation", if all the evaluation results of "line workability", "tightening or popping out" and "maneuverability" are "○ (good)", it is evaluated as "○ (good)". However, if any of the evaluation items was other than "○ (good)", it was evaluated as "× (impossible)".
[0115]
　By the way, if the inner diameter D of the mesh-like tube 10 is small, the optical fiber 5 may be tightened. On the other hand, when the inner diameter D is large, a gap is likely to be generated between the mesh-like tube 10 and the optical fiber 5, and the optical fiber 5 is likely to move inside the mesh-like tube 10. However, the phenomenon that the mesh-like tube 10 tightens the optical fiber 5 and the optical fiber 5 moves inside the mesh-like tube 10 not only depends on the inner diameter D, but also depends on the inner diameter D of the unit to be inserted into the mesh-like tube 10. It also depends on the diameter (unit diameter Y). Therefore, here, the value of D / Y is calculated as an index indicating the size of the inner diameter D with respect to the unit diameter Y.　
　Further, the longer the pitch P of the mesh-like tube 10, the larger the amount of deformation when the peripheral edge portion 10B of the mesh-like tube 10 is bent, and the inner diameter of the mesh-like tube 10 after deformation can be substantially increased. It is possible. Therefore, here, not only the index (D / Y) indicating the size of the inner diameter D with respect to the unit diameter Y, but also the value (P × D / Y) obtained by multiplying the index (D / Y) by the pitch P is calculated. ..
[0116]
　As shown in the evaluation result, when the D / Y was 1.4 (No. 9), the overall evaluation was “x (impossible)”. The reason for this is that there is a gap between the mesh-like tube 10 and the optical fiber 5, and the optical fiber 5 moves inside the mesh-like tube 10. Therefore, the D / Y is preferably 1.2 or less. Further, as shown in the evaluation result, when the D / Y was 0.5 (No. 40), the overall evaluation was “x (impossible)”. The reason for this is that the optical fiber 5 is tightened because the diameter (unit diameter) of the unit to be inserted into the mesh-like tube 10 is larger than the inner diameter D of the mesh-like tube 10. Therefore, the D / Y is preferably 0.6 or more. That is, it is desirable that D / Y is 0.6 or more and 1.2 or less (0.6 ≦ D / Y ≦ 1.2).
[0117]
　Further, as shown in the evaluation result, when P × D / Y was 4.8 (mm) (No. 14), the overall evaluation was “× (impossible)”. The reason for this is that the optical fiber 5 is tightened because the diameter (unit diameter) of the unit to be inserted into the mesh-like tube 10 is larger than the inner diameter D of the mesh-like tube 10. Therefore, it is desirable that P × D / Y is 6.0 (mm) or more. The reason why the overall evaluation was "x (impossible)" in the number 40 (P × D / Y is 6.0) is considered to be because the D / Y is small. Further, as shown in the evaluation result, when P × D / Y was 21.3 (mm) or more (Nos. 1, 17 to 19, 30), the overall evaluation was “× (impossible)”. The reason for this is that the optical fiber 5 has popped out. Therefore, it is desirable that P × D / Y is 20.0 or less. That is, it is desirable that P × D / Y is 6.0 (mm) or more and 20.0 (mm) or less (6.0 (mm) ≦ P × D / Y ≦ 20.0 (mm)).
[0118]
　Therefore, if 0.6 ≦ D / Y ≦ 1.2 and 6.0 (mm) ≦ P × D / Y ≦ 20.0 (mm), “wire passage workability” and “tightening” Or, all the evaluation results of "jumping out" and "maneuverability" were "○ (good)", and "comprehensive evaluation" was "○ (good)". Therefore, it is desirable that 0.6 ≦ D / Y ≦ 1.2 and 6.0 (mm) ≦ P × D / Y ≦ 20.0 (mm).
[0119]
　
　FIG. 20 is a table showing a third embodiment.
[0120]
　As a third embodiment, the first wire rod 11 and the second wire rod 12 are each four (8 in total), and a plurality of types of mesh-like tubes 10 in which the materials of the first wire rod 11 and the second wire rod 12 are different are created. did. The materials of the first wire rod 11 and the second wire rod 12 are three types of "two-layer monofilament", "single-layer monofilament", and "film" (see FIGS. 3A to 3C). Moreover, the cross-sectional shape (thickness) of each material (first wire rod 11 and second wire rod 12) is different. The thickness of each material (corresponding to T in FIGS. 3A to 3C) was measured with a thickness gauge (for this reason, "film" is better than "double layer monofilament" and "single layer monofilament". It tends to be a small value). In the third embodiment, the first wire rod 11 and the second wire rod 12 were adhered with an adhesive to prepare a mesh-like tube 10 (in contrast, in the fourth embodiment described later, the first wire rod 11 and the second wire rod 12 and the second wire rod 12 were formed. The wire rod 12 is fused).
[0121]
　In addition, the contraction ratio when each mesh-like tube 10 was contracted in the longitudinal direction was calculated. Here, the contraction ratio means the ratio of the length of the mesh-like tube at the time of contraction to the length of the mesh-like tube 10 before contraction. That is, the length (initial length) of the mesh-like tube 10 before being contracted in the longitudinal direction is L0, and the length (length at the time of contraction) of the mesh-like tube 10 after being contracted in the longitudinal direction is L1. Then, the shrinkage ratio Rl (%) is as shown in the following equation.
　Rl (%) = L1 / L0 × 100
[0122]
　The smaller the value of the shrinkage ratio Rl (%), the longer the optical fiber 5 and the mesh-like tube 10 can be pulled out when the optical fiber 5 shown in FIG. 11C is laid, which is advantageous.
[0123]
　As shown in FIG. 20, in any of the materials, the thinner the cross-sectional shape, the higher the shrinkage ratio Rl. This is because the thinner the first wire rod 11 and the second wire rod 12 in the thickness direction, the easier it is for the bent peripheral edge portion 10B to be displaced in the radial direction, as shown in FIG. 7B, and as a result, the amount of contraction in the longitudinal direction is reduced. This is because it grows larger. From this result, as shown in FIG. 7B, it can be confirmed that it is advantageous that the bent peripheral edge portion 10B is easily displaced in the radial direction.
[0124]
　As shown in FIG. 20, in any case, it was possible to realize that the contraction ratio Rl (%) was 13% or less. Further, as shown in FIG. 20, in the case of "double layer monofilament" and "single layer monofilament", the value of the shrinkage ratio Rl was smaller than that of "film". Specifically, in the "film", the shrinkage ratio Rl (%) is 11 to 13%, and the mesh-like tube 10 does not shrink from the initial length L0 to 1/10 or less. On the other hand, in the "double-layer monofilament" and the "single-layer monofilament", the shrinkage ratio Rl (%) is 4 to 8%, and the mesh-like tube 10 can shrink from the initial length L0 to 1/10 or less. It was possible (it was possible to shrink from the initial length L0 to 1/25 to 1 / 12.5). The reason for the difference in the value of the shrinkage ratio Rl is shown in FIG. 7B for the "double-layer monofilament" and the "single-layer monofilament" in which a large number of fibers are fused and integrated as compared with the film. As described above, it is considered that the bent peripheral edge portion 10B is easily displaced in the radial direction. Therefore, the material of the mesh-like tube 10 (first wire rod 11 and second wire rod 12) has a monofilament structure (two-layer monofilament or single-layer monofilament) in which a large number of fibers are fused and integrated rather than a film shape. Is desirable. As described above, the contraction ratio Rl (%) of the mesh-like tube 10 is preferably 13% or less. That is, the length (initial length) of the mesh-like tube 10 before being contracted in the longitudinal direction is L0, and the length (length at the time of contraction) of the mesh-like tube 10 after being contracted in the longitudinal direction is L1. At that time, it is desirable that L1 / L0 is 0.13 or less. Further, the shrinkage ratio Rl (%) of the mesh-like tube 10 is preferably 8% or less. That is, the length (initial length) of the mesh-like tube 10 before being contracted in the longitudinal direction is L0, and the length (length at the time of contraction) of the mesh-like tube 10 after being contracted in the longitudinal direction is L1. At that time, it is desirable that L1 / L0 is 0.08 or less.
[0125]
　
　FIG. 21 is a table showing the fourth embodiment.
[0126]
　As a fourth embodiment, the first wire rod 11 and the second wire rod 12 are each four (8 in total), and a plurality of types of mesh-like tubes 10 in which the materials of the first wire rod 11 and the second wire rod 12 are different are created. did. The materials of the first wire rod 11 and the second wire rod 12 are two types, "two-layer monofilament" and "single-layer monofilament" (see FIGS. 3A and 3B). Further, the cross-sectional shapes (thickness T shown in FIGS. 3A and 3B) of the respective materials (first wire rod 11 and second wire rod 12) are different. In the fourth embodiment, the first wire rod 11 and the second wire rod 12 were fused to form a mesh-like tube 10. In addition, the mesh-like tube 10 through which the bundle of optical fibers 5 is inserted is actually attached to the closure, and a heat cycle test (temperature condition: −40 ° C. to + 70 ° C., 2 cycles) is performed on the closure. The loss fluctuation amount (dB) of the optical fiber 5 at that time was measured (measurement wavelength 1.55 μm).
[0127]
　As shown in FIG. 21, the "single-layer monofilament" had a larger loss fluctuation amount of the optical fiber 5 than the "double-layer monofilament". The reason for this is that the mesh-like tube 10 using the single-layer monofilament tends to undergo heat shrinkage due to a heat load, and as a result, the optical fiber 5 inserted therein is tightened, and the transmission loss of the optical fiber 5 increases. It is considered to be. On the other hand, in the mesh-like tube 10 using the two-layer monofilament, the core portion 13 is not melted even when the mesh-like tube 10 is manufactured, so that the mesh-like tube 10 does not easily shrink due to heat even when a heat load is applied. it is conceivable that. Therefore, the material of the mesh-like tube 10 (first wire rod 11 and second wire rod 12) is preferably a two-layer monofilament rather than a single-layer monofilament.
[0128]
　The heat shrinkage of the above two-layer monofilament can be measured as follows. First, two marked lines are attached to a 2500 mm sample (wire rod) at predetermined intervals (here, 1000 mm intervals). Next, the sample is placed in a constant temperature bath at 80 ° C. for 2 hours. After leaving the sample from the constant temperature bath in a room temperature environment of 23 ° C. ± 2 ° C. (21 ° C. to 25 ° C.) for 30 minutes, the distance between the two marked lines is measured. When the distance between the first two marked lines before the heat treatment (here, 1000 mm) is Lb and the distance between the two marked lines measured after the heat treatment is La, the heat shrinkage rate Rt (%) is as shown in the following equation. Can be calculated.
　Rt (%) = {(Lb-La) / Lb} × 100
　And if the heat shrinkage rate Rt (%) of the first wire (and the second wire) is 1% or less, even if a heat load is applied. The mesh-like tube 10 is less likely to shrink due to heat, and the amount of fluctuation in loss of the optical fiber 5 can be suppressed. Therefore, it is desirable that the heat shrinkage rate Rt (%) of the first wire rod (and the second wire rod) is 1% or less.
[0129]
　Since it is desirable that the core portion 13 is not melted during the production of the mesh-like tube 10, the melting points of the core portions 13 of the first wire rod 11 and the second wire rod 12 constituting the mesh-like tube 10 are set to those of the covering portion 14. It is desirable that the temperature is 20 ° C. or higher higher than the melting point. Further, since the maximum temperature of the usage environment of the closure is generally about 80 ° C., it is desirable that the melting point of the covering portion 14 is 100 ° C. or higher.
[0130]
　=== Reference explanation ===
　 The Young's modulus and flexural rigidity of the two-layer monofilament wire (first wire 11 or second wire 12) shown in FIG. 3A were measured. Here, a two-layer monofilament wire made of an organic material was produced by using polyester as the core portion 13 and polypropylene as the covering portion 14. The cross-sectional shape of the wire was 0.1 mm thick and 1 mm wide. As a result of the measurement, the Young's modulus of the wire rod was about 4000 N / mm 2 , and the bending rigidity was about 0.5 N / mm 2 . The Young's modulus and flexural rigidity of the wire rod were measured as follows.
[0131]
　Young's modulus was measured using a tensile tester. Here, a test piece (wire) was set between chucks set to 200 mm, and a load-elongation curve was measured with a tensile speed of 200 mm / min. Further, the Young's modulus (unit: N / mm 2 ) of the wire rod was measured based on the inclination of the initial straight line portion of the measured load-elongation curve .
[0132]
　Flexural rigidity was measured based on a three-point bending test. FIG. 22A is an explanatory diagram of a method for measuring flexural rigidity. FIG. 22B is an explanatory diagram of a load-deflection diagram. As shown in FIG. 22A, a test piece (wire rod) was set between fulcrums whose distance L was set to 30 mm, and the flexural modulus E was measured based on a three-point bending test. Here, the bending load F1 when the amount of deflection becomes 1 mm and the bending load F5 when the amount of deflection becomes 5 mm are measured (see FIG. 22B), and based on the measured bending loads F1 and F5. The flexural modulus E was measured. The bending load F1 was measured using an electronic balance arranged below the fulcrum. The flexural rigidity EI (unit: N · mm 2 ) was calculated based on the measured flexural modulus E (unit: Pa) and the secondary elastic moment I (unit: mm 4 ) of the test piece .
[0133]
　 A
　plurality of different wires N (total number 2 N) of the first wire rod 11 and the second wire rod 12, the inner diameter D of the mesh tube 10, the spiral pitch L, and the outer diameter S of the tubular member 22. A type of protection unit 20 was created. Here, the number of the first wire rod 11 and the second wire rod 12 is 4 (8 in total) or 6 (12 in total), respectively. The inner diameter D of the mesh tube 10 was set in the range of 6.3 mm to 8.3 mm. The spiral pitch L was set to 20 mm to 100 mm. The outer diameter S of the tubular member 22 was set in the range of 3.5 mm to 8 mm.
[0134]
　The contraction ratio Rl when each mesh-like tube 10 was contracted in the longitudinal direction was measured. The length (initial length) of the mesh-like tube 10 before shrinking in the longitudinal direction was set to L0, and the length (length during contraction) of the mesh-like tube 10 after shrinking in the longitudinal direction was set to L1. Then, the contraction ratio Rl (%) is as shown in the following equation.
　Rl (%) = L1 / L0 × 100
[0135]
　The measurement results of the shrinkage ratio Rl of each mesh-like tube 10 are as shown in the following table (it was confirmed that a shrinkage ratio Rl of 3 to 12% can be realized). When each mesh-like tube 10 was contracted in the longitudinal direction, the mesh-like tube 10 could be easily folded in the longitudinal direction by the force of a hand, and the tubular member 22 did not buckle.
[0136]
[table 1]

[0137]
　 A
　plurality of types of mesh tubes 10 having different mesh ratios R were prepared by changing the number of the first wire rod 11 and the second wire rod 12 of the mesh tube 10 and the spiral pitch. Here, the number of the first wire rod 11 and the second wire rod 12 is 4 (8 in total) or 6 (12 in total), respectively. The spiral pitch was 50 mm or 100 mm. The ratio of the area occupied by the opening 10A on the developing surface to the total area of ​​the mesh tube on the developing surface (the sum of the area occupied by the opening 10A and the area occupied by the peripheral edge 10B) is defined as the mesh ratio R (%). At that time, the mesh ratio R of each mesh tube 10 was 46.2%, 55.5%, and 49.4%.
[0138]
　The work of actually attaching the mesh-like tube 10 through which the bundle of the optical fibers 5 is inserted to the closure is performed, and the optical fiber 5 (the optical fiber tape inserted through the mesh-like tube 10) or the mesh-like tube 10 is configured at the time of this attachment work. The evaluation was performed according to whether or not the peripheral edge portion 10B (first wire rod 11 or second wire rod 12) was caught in the peripheral member. When there was no catch, it was evaluated as "○ (good)", and when there was a catch, it was evaluated as "× (bad)". The evaluation results of the catching of the peripheral members in each of the mesh-like tubes 10 are as shown in the following table.
[0139]
[Table 2]

[0140]
　 The number of optical fibers n, the number N of each of the first wire rod 11 and the second wire rod 12 (total number 2N), the inner diameter D of the mesh tube 10, the pitch P, and the shape of the opening 10A A plurality of different types of mesh-like tubes 10 were prepared. Here, the number of 12-core intermittently connected optical fiber tapes is 12 or 24, and the number n of optical fibers is 144 or 288. The number of the first wire rod 11 and the second wire rod 12 was set to 4 (8 in total) or 6 (12 in total), respectively. The inner diameter D of the mesh tube 10 was set in the range of 6.3 mm to 8.3 mm. The pitch P was set to 8.3 mm to 45 mm (spiral pitch was 50 mm to 270 mm). In addition, the shape of the opening is a rhombus, and the lengths of the two diagonal lines of the rhombus are different from each other (in the table, the length of the diagonal line along the longitudinal direction (opening length in the longitudinal direction) and the circumference are shown. The length of the diagonal line along the direction (opening length in the circumferential direction) is described).
[0141]
　When each mesh-like tube 10 was bent with a bending radius of 15 mm, it was confirmed whether or not the optical fiber 5 protruded from the opening 10A of the mesh-like tube 10. Further, when the bent mesh tube was pulled inward (toward the bending center side), it was confirmed whether or not the optical fiber 5 protruded from the opening 10A of the mesh tube 10. The results of the presence or absence of the optical fiber protruding in each of the mesh-like tubes 10 are shown in the following table.
[0142]
[Table 3]

[0143]
　As shown in Table 3, the shorter the opening length in the longitudinal direction, the more difficult it is for the optical fiber 5 to pop out from the opening 10A of the mesh-like tube 10. When the shape of the opening is rhombic and the opening length in the longitudinal direction is 18 mm or less, the protrusion of the optical fiber 5 when the mesh-like tube 10 is bent can be suppressed. Further, when the shape of the opening is a rhombus and the opening length in the longitudinal direction is 14 mm or less, the protrusion of the optical fiber 5 when the mesh-like tube 10 in the bent state is pulled can be suppressed.
[0144]
　Next, a plurality of types of mesh-like tubes 10 having different shapes of the openings 10A were created. Here, the mesh-like tube 10 is formed as one tubular member in which a large number of openings 10A are formed, and the openings 10A are formed in a slit shape or a rectangular shape. In the case of the slit-shaped opening 10A, the slit was formed along the longitudinal direction, and the slit width (the length of the opening in the circumferential direction) was set to less than 0.5 mm. The width of the peripheral edge portion 10B (dimension in the circumferential direction of the peripheral edge portion 10B) between the opening 10A and the opening 10A adjacent to each other in the circumferential direction is set to 4 mm when the opening 10A has a slit shape. When the portion 10A has a rectangular shape, it is set to 2 mm. In the same manner as described above, it is confirmed whether or not the optical fiber 5 protrudes from the opening 10A of the mesh-like tube 10 when the mesh-like tube 10 is bent and when the mesh-like tube 10 in the bent state is pulled inward. did. The results of the presence or absence of the optical fiber protruding in each of the mesh-like tubes 10 are shown in the following table.
[0145]
[Table 4]

[0146]
　As shown in Tables 3 and 4, regardless of the shape of the opening 10A, the shorter the opening length in the longitudinal direction, the more difficult it is for the optical fiber 5 to pop out from the opening 10A of the mesh tube 10. When the opening length of the opening 10A in the longitudinal direction was 20 mm or less, the protrusion of the optical fiber 5 when the mesh-like tube 10 was bent could be suppressed. Further, when the opening length of the opening 10A in the longitudinal direction is 14 mm or less, it is possible to suppress the protrusion of the optical fiber 5 when the mesh-like tube 10 in the bent state is pulled.
[0147]
　
　Create a plurality of types of mesh-like tubes 10 having different numbers N (total number 2N) of the first wire rod 11 and the second wire rod 12, the inner diameter D of the mesh-like tube 10, and the pitch P. did. Here, the number of the first wire rod 11 and the second wire rod 12 is 4 (8 in total) or 6 (12 in total), respectively. The inner diameter D of the mesh tube 10 was set to 6.3 mm or 8.3 mm. The spiral pitch L was set to 50 mm.
[0148]
　A tensile force of 180 N is applied to each of the mesh-like tubes 10, and the first wire rod 11 and the first wire rod 10C of the branch portion 10C (branch portion 10C in which the intersection of the first wire rod 11 and the second wire rod 12 is fused and joined). 2 It was confirmed whether or not the wire rod 12 was separated from the wire rod 12. The results of the presence or absence of separation of the branch portion 10C in each mesh-like tube 10 are as shown in the following table (it was confirmed that the branch portion 10C was not destroyed by the tensile force of 180 N).
[0149]
[Table 5]

[0150]
　
　Twelve optical fiber units 3 in which 288 optical fibers are inserted into the mesh-like tube 10 having an outer diameter of 8.3 mm are prepared, and the 12 optical fiber units 3 are bundled. The outer peripheral length of the bundle of 12 optical fiber units was measured. For comparison, 12 polyethylene protective tubes (outer diameter 9.7 mm, wall thickness 0.7 mm) through which 288 optical fibers were inserted were prepared, and 12 protective tubes were bundled to provide 12 tubes. The outer circumference length of the bundle of protective tubes was measured. By winding a string around the outer circumference of the bundled 12 optical fiber units or the outer circumference of the bundled 12 protective tubes and measuring the length of the string, the outer circumference length of each bundle is measured. Was measured. Since the optical fiber unit 3 using the mesh-like tube 10 is more likely to deform its cross-sectional shape than the polyethylene protective tube, the outer peripheral length of the bundle of 12 polyethylene protective tubes is 14 mm, whereas it is 14 mm. The outer peripheral length of the bundle of 12 optical fiber units 3 using the mesh-like tube 10 was 10 mm.
[0151]
　=== Others === The
　above-described embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. It goes without saying that the present invention can be modified or improved without departing from the spirit thereof, and the present invention includes an equivalent thereof.
Code description
[0152]
1 Optical cable, 3 Optical fiber unit,
5 Optical fiber, 10 mesh tube,
10A opening, 10B peripheral part, 10C branch part,
10X end (1st end, 2nd end),
11 1st wire, 12 2nd Wire rod,
13 core part, 14 covering part,
20 protection unit, 22 tubular member,
22A 1st end, 22B 2nd end,
40 rack, 41 terminal equipment,
42 optical module, 44 connector connection port,
50 branch member, 51 main body Part,
52 1st fixing part, 521 support part, 522 fastening member,
53 2nd fixing part, 531 gripping part, 531A recess,
54 accommodating part, 541 upstream side stopper, 542 downstream side stopper,
57 lid part, 57A inlet ,
70 Manufacturing equipment, 71 1st supply unit,
71A 1st supply source, 71B 1st rotation unit,
72 2nd supply unit, 72A 2nd supply source, 72B 2nd rotation unit,
73 guide unit, 74 heating unit, 75 Tube contraction part
The scope of the claims
[Claim 1]
　A mesh-like tube in which a plurality of openings are formed in a mesh shape and a plurality of optical fibers are inserted therein,
　and
　is formed at a boundary between a peripheral portion forming the openings and three or more of the openings. 　A mesh-like tube comprising the above-mentioned bifurcated portion having an extended peripheral portion
, and the
peripheral portion is restrained by the bifurcated portion and is bendable.
[Claim 2]
　The mesh-like tube according to claim 1,
　wherein the mesh-like tube is folded in the longitudinal direction by bending the peripheral edge portion.
[Claim 3]
　The mesh-like tube according to claim 2,
　wherein the bent portion of the peripheral edge portion is plastically deformed, and the peripheral edge portion is held in a bent shape.
[Claim 4]
　The mesh-like tube according to any one of claims 1 to 3,
　wherein the mesh-like tube is
　　　　arranged in a
　　　　direction different from that of a plurality of first wire rods spirally arranged in a predetermined direction and the first wire rod. has been a plurality of second wire rod
having a
　first wire material or the and the peripheral portion by the second wire member is constituted,
　the by joint joining the intersection of the second wire member and said first wire rod A mesh-like tube characterized by having a bifurcation.
[Claim 5]
　The mesh-like tube according to claim 4,
　wherein the intersection of the first wire rod and the second wire rod is fused and joined.
[Claim 6]
　The mesh-like tube according to any one of claims 1 to 5
　, wherein two or more of the branch portions are present on a cross section in which the branch portion is present.
[Claim 7]
　The mesh-like tube according to claim 6
　, wherein three or more of the branch portions are present on a cross section in which the branch portion is present.
[Claim 8]
　The mesh-like tube according to any one of claims 1 to 7,
　wherein the area occupied by the opening when the mesh-like tube is unfolded is S1, and the area occupied by the peripheral edge is S2. A mesh-like tube characterized in that the value of S1 / (S1 + S2) is 0.555 or less.
[Claim 9]
　The mesh-like tube according to any one of claims 1 to 8, wherein
　the length of the mesh-like tube before shrinking in the longitudinal direction is L0, and the
　length of the mesh-like tube after shrinking in the longitudinal direction is defined as L0.
　A mesh-like tube characterized in that L0 / L1 is 0.13 or less when L1 is set.
[Claim 10]
　The mesh-like tube according to any one of claims 1 to 9,
　wherein the optical fiber can be inserted from an end portion of the mesh-like tube.
[Claim 11]
　The mesh-like tube is provided with a mesh-like tube in which an opening is formed in a mesh shape and a
　plurality of optical fibers are inserted therein, and a tubular member which
is inserted into the
　mesh-like tube and allows a plurality of optical fibers to be inserted therein. includes
　　　　a peripheral portion forming the opening,
　　　　formed at the boundary of three or more of the openings, and the branch portion to which the peripheral edge of three or more is extended out
has,
　the peripheral portion, at the branch portion
An optical fiber protection unit characterized by being restrained and bendable .
[Claim 12]
　The optical fiber protection unit according to claim 11,
　wherein the mesh-like tube is arranged on the outer periphery of the tubular member in a state where the peripheral edge portion is bent and folded in the longitudinal direction. Fiber optic protection unit.
[Claim 13]
　The optical fiber protection unit according to claim 12,
　wherein the end portion of the mesh-like tube is pulled out from the tubular member, and the mesh-like tube in a folded state can be extended in the longitudinal direction. Fiber optic protection unit.
[Claim 14]
　The optical fiber protection unit according to claim 13,
　wherein the opening at at least one end of the tubular member is widened.
[Claim 15]
　The optical fiber protection unit according to claim 14,
　wherein the outer diameter of the end portion having a wide opening is larger than the inner diameter of the mesh-like tube in a folded state. ..
[Claim 16]
　A mesh-like tube having openings formed in a mesh shape, and a peripheral portion forming the opening and a branch portion formed at the boundary of three or more openings and extending three or more peripheral portions. To prepare a mesh-like tube in which the peripheral portion is restrained by the branch portion and is bendable, and a
　plurality of optical fibers are inserted from the end portion of the mesh-like tube to form the mesh-like tube.
An optical fiber protection method, characterized in that the plurality of optical fibers are inserted therein .
[Claim 17]
　The optical fiber protection method according to claim 16,
　wherein the peripheral portion is bent to prepare the mesh-like tube folded in the longitudinal direction, and
　from the end portion of the mesh-like tube in the folded state. The plurality of optical fibers are inserted and the plurality of optical fibers are inserted into the folded mesh-like tube, and the
　mesh-like tube is extended to extend the mesh-like tube.
An optical fiber protection method, characterized in that the plurality of optical fibers are inserted therein .
[Claim 18]
　The optical fiber protection method according to claim 17,
　wherein the optical fiber protection method includes the mesh-like tube in which the peripheral edge portion is bent and folded in the longitudinal direction, and a tubular member inserted through the mesh-like tube. By preparing a unit and
　inserting an optical fiber into the tubular member, a plurality of the optical fibers are inserted from the end of the mesh-like tube in a folded state, and the mesh-like tube in a folded state is inserted. A
method for protecting an optical fiber, which comprises inserting the plurality of optical fibers into the inside of the optical fiber .
[Claim 19]
　The optical fiber protection method according to any one of claims 16 to 18,
　wherein the mesh-like tube has a plurality of first wire rods spirally arranged in a predetermined direction and a direction different from the first wire rod. It has a plurality of arranged second wires, the intersections of the first wire and the second wire are joined, and
　the pitch of the intersections in the longitudinal direction is P (mm), and the mesh tube When the inner diameter is D (mm) and the diameter of the unit composed of the plurality of optical fibers is Y (mm),
　0.6 ≦ D / Y ≦ 1.2
and
　6.0 (mm) ≦ P.
An optical fiber protection method, characterized in that × D / Y ≦ 20.0 (mm) .
[Claim 20]
　A mesh-like tube in which an opening is formed in a mesh shape and a plurality of optical fibers are inserted therein, and is formed at a boundary between a peripheral portion forming the opening and three or more of the openings. A mesh-like tube having a branch portion having an extended peripheral edge portion and the peripheral edge portion being restrained by the branch portion and being bendable is formed, and the
　optical fiber is inserted into the mesh-like tube. A
method of manufacturing a mesh tube, characterized in that a possible end is formed .
[Claim 21]
　The mesh-like tube manufacturing method according to claim 20,
　wherein the peripheral edge portion is bent and the mesh-like tube is folded in the longitudinal direction.
[Claim 22]
　The mesh-like tube manufacturing method according to claim 20 or 21, wherein
　a plurality of first wires are supplied to a heating unit while being twisted in a predetermined direction, and a plurality of second wires
　are twisted in a direction opposite to that of the first wire. supplying a wire to the heating unit, and
　the possible fusing the intersection between the second wire rod and the first wire rod in the heating unit
by performing,
　the peripheral edge portion by the first wire member and the second wire rod The method for manufacturing a mesh-like tube, which comprises forming the mesh-like tube in which the branch portion is formed by a joint portion formed by joining the intersections of the first wire rod and the second wire rod.