Optical Closure

Abstract

To provide an optical closure capable of having sufficient mechanical strength when installed on a road surface.SOLUTION: An optical closure stores an optical fiber. The optical closure comprises a housing and a storage tray. The housing has a metallic main body part, and a metallic lid part opposed to the main body part in a predetermined direction. The housing has a space where the optical fiber is stored between the main body part and the lid part. The storage tray has a mount surface where the optical fiber is mounted and a guide provided on the mount surface and guiding the optical fiber, and is arranged in the space of the housing. The housing further has at least one metallic column part provided between the main body part and lid part in the space to support the lid part.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to optical closures. [Background technology]

[0002] Patent Document 1 discloses an optical cable connection closure for connecting an optical cable and a drop cable in an aerial environment. The optical cable connection closure includes a closure body having a cable housing portion and a cable inlet for introducing the optical cable and the drop cable into the cable housing portion.

[0003] Patent Document 2 discloses an optical fiber cable connection closure. The optical fiber cable connection closure has a closure body, an optical cable lead-out port, a drop cable lead-out port, and a splice housing tray arranged within the closure body. The optical fiber lead-out port leads out or introduces an aerial optical cable. The drop cable lead-out port leads out or introduces a drop cable. The splice housing tray connects the optical fiber core drawn out from the optical cable to the drop cable. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-47336 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-123245 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, optical communication networks have expanded rapidly. For example, with the spread of fifth-generation mobile communication systems (5G), the number of slave stations is expected to increase in urban and suburban areas, and the number of locations where optical fiber cables are laid connecting master stations and slave stations is expected to increase. Furthermore, in non-residential areas, the number of master stations and slave stations is also expected to increase, and the number of locations where optical fiber cables are laid connecting master stations and master stations and slave stations is expected to increase. However, existing facilities such as utility poles are not necessarily present at the locations where optical fiber cables are to be laid. Therefore, it is desirable to be able to easily lay optical fiber cables and pull them into buildings without relying on existing facilities such as utility poles.

[0006] Therefore, it is conceivable to lay an optical fiber cable on the road surface. In this case, an optical closure provided midway along the optical fiber cable will also be installed on the road surface, and therefore the optical closure is required to have sufficient mechanical strength so that the optical fiber inside will not be affected even when pedestrians and vehicles pass over the optical closure. An object of the present disclosure is to provide an optical closure that has sufficient mechanical strength when installed on the road surface. [Means for solving the problem]

[0007] An optical closure according to one aspect of the present disclosure is an optical closure for storing optical fibers, and includes a housing and a storage tray. The housing has a metal main body and a metal lid facing the main body in a predetermined direction. The housing further includes a space for storing the optical fiber and an inlet for introducing the optical fiber into the space, between the main body and the lid. The storage tray has a mounting surface on which the optical fiber is placed and a guide provided on the mounting surface for guiding the optical fiber, and is disposed within the space of the housing. The housing further includes at least one metal post provided between the main body and the lid in the space and supporting the lid. [Effects of the Invention]

[0008] According to the present disclosure, an optical closure can be provided that has sufficient mechanical strength when installed on a road surface. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the appearance of an optical closure according to an embodiment of the present disclosure. [Figure 2] Portion 2-A of Fig. 2 is a plan view of the optical closure, portion 2-B of Fig. 2 is a front view of the optical closure, and portion 2-C of Fig. 2 is a side view of the optical closure. [Figure 3] FIG. 3 is a perspective view showing the appearance of the lid portion. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. [Figure 5] FIG. 5 is a perspective view showing the optical closure with the cover removed. [Figure 6] FIG. 6 is a perspective view showing the optical closure shown in FIG. 5 with the pulled-through fiber cable holding tray open. [Figure 7] FIG. 7 is an enlarged perspective view of a part of FIG. [Figure 8] FIG. 8 is an enlarged perspective view showing the attachment portion of the pulled-through fiber conductor holding tray to the connection fiber conductor tray. [Figure 9] FIG. 9 is a perspective view showing the appearance of the main body and the column. [Figure 10] FIG. 10 is a diagram showing a part of a cross section taken along line XX in FIG. [Figure 11] FIG. 11 is an enlarged view of a part of the rear surface of the main body. [Figure 12] FIG. 12 is a diagram showing a part of a cross section taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a perspective view showing the appearance of the connection core wire tray. [Figure 14] FIG. 14 is a perspective view showing the appearance of the through-hole fiber holding tray. [Figure 15] FIG. 15 is a perspective view showing the appearance of the tray protection sheet. [Figure 16] FIG. 16 is a diagram showing an example of how optical fibers are routed in a connection core wire tray. [Figure 17] FIG. 17 is a diagram showing an example of how optical fibers are routed in a connection core wire tray. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0011] [1] An optical closure according to one aspect of the present disclosure is an optical closure for storing optical fibers, comprising a housing and a storage tray. The housing has a metal main body and a metal lid facing the main body in a predetermined direction. The housing further has a space for storing the optical fiber and an inlet for introducing the optical fiber into the space, between the main body and the lid. The storage tray has a mounting surface on which the optical fiber is placed and a guide provided on the mounting surface for guiding the optical fiber, and is disposed within the space of the housing. The housing further has at least one metal pillar provided between the main body and the lid in the space and supporting the lid.

[0012] In this optical closure, the space within the housing that houses the optical fiber is formed by a metal main body and a metal lid. Therefore, mechanical strength can be improved compared to conventional optical closures that are mainly made of resin. In addition, the housing of this optical closure has at least one metal pillar. The pillar is located between the main body and the lid within the space and supports the lid. Therefore, deformation of the lid due to forces from above when a pedestrian or vehicle passes over the optical closure can be suppressed. Therefore, this optical closure has sufficient mechanical strength when installed on a road surface.

[0013] [2] In the optical closure of [1] above, the lid may have a first surface facing the main body, a second surface facing away from the first surface, and a rib provided on the second surface and having a mesh (grid) shape in plan view. Having the mesh-like rib on the lid further increases the mechanical strength of the lid and further suppresses deformation of the lid due to force from above. Additionally, having the mesh-like rib on the second surface can also serve as a non-slip surface for pedestrians and the like.

[0014] [3] In the optical closure of [2] above, the lid may have a first portion including a recess on the first surface that forms a space, and a second portion provided around the first portion, in contact with the main body portion, and fixed to the main body portion. The second surface of the second portion may be located closer to the main body portion than the second surface of the first portion, and a rib provided on the second surface of the second portion may have a height from the second surface that is greater than a height from the second surface of the first portion. In this case, the first portion can provide a space for accommodating the optical fiber. Furthermore, the mechanical strength of the lid can be further improved by increasing the height of the rib provided around the first portion.

[0015] [4] In any of the optical closures [1] to [3] above, the storage tray may have a first opening formed inside the guide to allow the column to pass through. In this case, the space inside the guide can be effectively used as the column, thereby improving space utilization efficiency.

[0016] [5] In the optical closure of [4] above, the housing may have a plurality of pillars. The storage tray may further have a second opening formed outside the guide for passing another pillar. The cross-sectional area of the pillar passing through the first opening, in a cross section perpendicular to the predetermined direction, may be larger than the cross-sectional area of the other pillar passing through the second opening, in a cross section perpendicular to the predetermined direction. In this way, by making the cross-sectional area of the pillars arranged outside the guide smaller than the cross-sectional area of the pillars arranged inside the guide, it is possible to reduce the interference caused by the pillars with the routing of the optical fiber within the storage tray.

[0017] [6] In any of the optical closures [1] to [3] above, the storage tray may have an opening formed on the outside of the guide to allow the post to pass through. In this way, even if the post is located on the outside of the guide, an optical closure having sufficient mechanical strength when installed on a road surface can be provided.

[0018] [7] In any of the optical closures [1] to [6] above, the posts may be integral with the main body, and the top surfaces of the posts may abut against the lid. In this case, the number of parts of the optical closure can be reduced, making assembly easier.

[0019] [8] In the optical closure [7], the top surfaces of the posts may be flat. In this case, the contact area between the lid and the posts can be increased, thereby reducing stress concentration.

[0020] [9] In any of the optical closures [1] to [8] above, the housing may have a plurality of columns, one or more of which may be provided on the outside of the storage tray. In this way, even if the columns are provided on the outside of the storage tray, an optical closure having sufficient mechanical strength when installed on a road surface can be provided. [Details of the embodiments of the present disclosure]

[0021] Specific examples of optical closures according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, identical elements in the drawings will be designated by the same reference numerals, and duplicate descriptions will be omitted.

[0022] FIG. 1 is a perspective view showing the appearance of an optical closure 1 according to an embodiment of the present disclosure. Section 2-A of FIG. 2 is a plan view of the optical closure 1. Section 2-B of FIG. 2 is a front view of the optical closure 1. Section 2-C of FIG. 2 is a side view of the optical closure 1. The optical closure 1 of this embodiment is an optical closure for storing an excess length of optical fiber. Unlike typical optical closures that are installed aerial, the optical closure 1 is installed on a road surface such as a sidewalk or roadway. As shown in FIGS. 1 and 2, the optical closure 1 has a rectangular planar shape and a plate-like appearance. In the following description, the direction along the longer side of the rectangle is defined as the vertical direction, and the direction along the shorter side is defined as the horizontal direction. The thickness of the optical closure 1 is extremely small compared to the vertical and horizontal dimensions of its planar shape. The thickness of the optical closure 1 is preferably 20 mm or less. Furthermore, the thickness of each of the lid and main body is preferably 4 mm or less. In one embodiment, the optical closure 1 has a vertical dimension of 305 mm, a horizontal dimension of 122.5 mm, and a thickness of 14.5 mm. Thus, the thickness of the optical closure 1 is 1 / 8 or less of the smaller of the vertical and horizontal dimensions.

[0023] As shown in FIGS. 1 and 2, the optical closure 1 includes a housing 2. The housing 2 has a lid portion 10 and a main body portion 20. Both the lid portion 10 and the main body portion 20 are made of metal. In one example, the lid portion 10 and the main body portion 20 are mainly made of stainless steel, and in another example, the lid portion 10 and the main body portion 20 are mainly made of an aluminum alloy. The lid portion 10 and the main body portion 20 can be formed by various methods, such as cutting or casting. The lid portion 10 faces the main body portion 20 in the thickness direction (predetermined direction) of the optical closure 1. When the optical closure 1 is installed on a road surface, the thickness direction of the optical closure 1 is along the normal to the road surface. The lid portion 10 is fixed to the main body portion 20 by a plurality of screws 35 (ten in the illustrated example). The plurality of screws 35 are arranged in a row along the periphery of the lid portion 10.

[0024] A plurality of optical fiber introduction ports 9 are provided on both vertical end faces of the optical closure 1, and optical fiber cables 31, 32, and 33 and an optical fiber bundle 34 are introduced into the optical closure 1 from these optical fiber introduction ports 9. Each of the optical fiber cables 31, 32, and 33 and the optical fiber bundle 34 includes a plurality of optical fibers. In the following description, optical fiber mainly refers to an optical fiber core.

[0025] Fig. 3 is a perspective view showing the appearance of the lid 10. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. As shown in Figs. 3 and 4, the lid 10 has a rectangular planar shape and a plate-like appearance. The lid 10 has vertical side faces 12a and 12b and horizontal end faces 12c and 12d. The end faces 12c and 12d have a plurality of notches 9a aligned horizontally, which form the optical fiber introduction port 9 shown in Figs. 1 and 2.

[0026] The lid portion 10 has a first surface 15 (see FIG. 4) facing the main body portion 20 and a second surface 11 facing away from the first surface 15. The normal directions of the first surface 15 and the second surface 11 coincide with the thickness direction of the optical closure 1. The lid portion 10 also has a first portion 10a and a second portion 10b. The first portion 10a is located in the center of the lid portion 10 and has a planar shape that is, for example, rectangular. The second portion 10b is located around the first portion 10a and surrounds the first portion 10a in a planar view.

[0027] The first portion 10a includes a recess 15a provided in the first surface 15, thereby forming a space for accommodating an optical fiber inside the housing 2. Ribs 12 having a mesh-like planar shape are provided on the second surface 11 of the first portion 10a. The ribs 12 protrude from the second surface 11 in the direction of the normal vector of the second surface 11. Furthermore, ribs 13 having a mesh-like planar shape are provided on the second surface 11 of the second portion 10b. The ribs 13 protrude from the second surface 11 in the direction of the normal vector of the second surface 11. The second surface 11 of the second portion 10b is located closer to the main body 20 than the second surface 11 of the first portion 10a, and a height H2 of the ribs 13 relative to the second surface 11 of the second portion 10b is greater than a height H1 of the ribs 12 relative to the second surface 11 of the first portion 10a. The height of the top surface of rib 12 and the height of the top surface of rib 13 are aligned with each other when the back surface of optical closure 1 (i.e., the back surface of main body 20) is used as the reference. In other words, the difference between height H1 of rib 12 when the second surface 11 of first portion 10a is used as the reference and height H2 of rib 13 when the second surface 11 of second portion 10b is used as the reference is equal to the difference between the height of second surface 11 of first portion 10a and the height of second surface 11 of second portion 10b when the back surface of optical closure 1 is used as the reference.

[0028] The first surface 15 of the second portion 10b contacts the main body 20. The second portion 10b is fixed to the main body 20. To this end, a plurality of circular holes 14 are formed in the periphery of the second portion 10b. A screw 35 shown in FIGS. 1 and 2 is inserted into each hole 14.

[0029] FIG. 5 is a perspective view showing the optical closure 1 with the lid 10 removed. FIG. 6 is a perspective view showing the optical closure 1 shown in FIG. 5 with the pulled-through fiber storage tray 50 open. FIG. 7 is a perspective view showing an enlarged portion of FIG. 6. As shown in FIGS. 5, 6, and 7, the optical closure 1 of this embodiment further includes, in addition to the lid 10 and the main body 20, pillars 21 to 28, a gasket 36, a splicing fiber tray 40, a pulled-through fiber storage tray 50, and a tray protective sheet 60. The pillars 21 to 28, the splicing fiber tray 40, the pulled-through fiber storage tray 50, and the tray protective sheet 60 are arranged in a space formed between the lid 10 and the main body 20 for storing optical fibers. The splicing fiber tray 40 is placed on the main body 20 and fixed to the main body 20 with a plurality of screws 37. The pulled-through fiber conductor reserve tray 50 is placed on the splicing fiber conductor tray 40 and is attached so as to be able to open and close relative to the splicing fiber conductor tray 40. The tray protection sheet 60 is placed on the pulled-through fiber conductor reserve tray 50.

[0030] FIG. 8 is an enlarged perspective view showing the attachment portion of the pull-through fiber reserve tray 50 to the splicing fiber tray 40. The pull-through fiber reserve tray 50 has multiple cylindrical rotating shafts 51. The rotating shafts 51 are provided on one of a pair of vertically extending side surfaces of the pull-through fiber reserve tray 50, and their central axes extend along the vertical direction. The splicing fiber tray 40 has multiple bearings 41 that respectively support the multiple rotating shafts 51. The bearings 41 rotatably support the rotating shafts 51. As a result, the rotating shafts 51 and the bearings 41 form a hinge, allowing the pull-through fiber reserve tray 50 to open and close relative to the splicing fiber tray 40. As shown in FIG. 13, the bearings 41 are provided on both of a pair of vertically extending side surfaces of the splicing fiber tray 40. This allows the rotating shafts 51 to be attached to either of the pair of side surfaces of the splicing fiber tray 40.

[0031] Fig. 9 is a perspective view showing the appearance of the main body 20 and the column sections 21 to 28. As shown in Fig. 9, the main body 20 has a rectangular planar shape and a plate-like appearance. The main body 20 has a recess that, together with the recess 15a of the lid 10, forms a space for storing optical fibers. The bottom surface 20b of the recess is lower than the surrounding area and is flat. The bottom surface 20b includes an area 20a that overlaps with the splicing fiber tray 40 and the pulled fiber storage tray 50, which will be described later.

[0032] The pillars 21 to 28 are made of metal, are provided in the space that accommodates the optical fiber, and support the lid 10. The pillars 21 to 28 protrude from the bottom surface 20b toward the lid 10. In one example, the pillars 21 to 28 are mainly made of stainless steel, and in another example, the pillars 21 to 28 are mainly made of an aluminum alloy. The pillars 21 to 28 can be formed by various methods, such as cutting or casting. In another example, the pillars 21 to 28 are formed integrally with the main body 20. That is, the pillars 21 to 28 are cut out together with the main body 20 from a single metal block. Alternatively, the pillars 21 to 28 are cast together with the main body 20 in a single mold. The pillars 21 to 28 may be formed as separate parts from the main body 20 and then joined to the bottom surface 20b of the main body 20.

[0033] The pillars 21 and 22 are disposed on the region 20a. The pillars 21 and 22 are cylindrical with their central axes aligned in the thickness direction of the optical closure 1, and are disposed side by side at intervals in the vertical direction of the main body 20. The pillars 21 and 22 have flat top surfaces 21a and 22a, respectively. The top surfaces 21a and 22a have circular planar shapes. The top surfaces 21a and 22a abut against the recess 15a (see FIG. 4) of the lid 10. The diameters of the pillars 21 and 22 are greater than the heights of the pillars 21 and 22 relative to the bottom surface 20b (in other words, the distances between the bottom surface 20b and the top surfaces 21a and 22a).

[0034] The pillars 23 and 24 are also disposed on the region 20a. The pillars 23 and 24 are cylindrical with their central axes aligned in the thickness direction of the optical closure 1. They are spaced apart from each other in the vertical direction of the main body 20 and are disposed between the pillars 21 and 22 in the same direction. The pillars 23 and 24 have flat top surfaces 23a and 24a, respectively. The top surfaces 23a and 24a have circular planar shapes. The top surfaces 23a and 24a abut against the recess 15a of the lid 10 (see FIG. 4). The diameters of the pillars 23 and 24 are smaller than the heights of the pillars 23 and 24 relative to the bottom surface 20b (in other words, the distances between the bottom surface 20b and the top surfaces 23a and 24a). The diameters of the pillars 23 and 24 are smaller than the diameters of the pillars 21 and 22. In other words, the cross-sectional area of the pillars 23 and 24 in a cross section perpendicular to the thickness direction of the optical closure 1 is smaller than the cross-sectional area of the pillars 21 and 22 in a cross section perpendicular to the same direction.

[0035] FIG. 10 is a diagram showing a portion of a cross section taken along line XX in FIG. 9, including cross sections of the pillar portions 21, 22, 23, and 24. As shown in FIG. 10, a recess 29a is formed in the area of the back surface 29 of the main body portion 20 that overlaps with the pillar portion 21. A recess 29b is formed in the area of the back surface 29 of the main body portion 20 that overlaps with the pillar portion 22. As a result, the interiors of the pillar portions 21 and 22 are hollowed out, and the thickness of the portions of the pillar portions 21 and 22 that form the top surfaces 21a and 22a is approximately equal to the thickness of the portion of the main body portion 20 that forms the bottom surface 20b. On the other hand, no recess is formed in the area of the back surface 29 of the main body portion 20 that overlaps with the pillar portions 23 and 24, and the back surface 29 is flat in that area. Therefore, the pillar portions 23 and 24 are formed solid.

[0036] Furthermore, ribs 211 are provided in the recesses 29a and 29b. The ribs 211 protrude from the bottom surfaces of the recesses 29a and 29b in the direction of the normal vector of the bottom surfaces. FIG. 11 is an enlarged view of a portion of the rear surface 29, illustrating the planar shape of the ribs 211. As shown in FIG. 11, the ribs 211 are formed, for example, in the shape of a cross. The top surfaces of the ribs 211 are flush with the rear surface 29 excluding the recesses 29a and 29b. In other words, the height of the ribs 211 relative to the bottom surfaces of the recesses 29a and 29b is equal to the depth of the recesses 29a and 29b.

[0037] Referring again to FIG. 9 , the pillars 25, 26, 27, and 28 are arranged outside the area 20a, i.e., outside the splice fiber tray 40 and the pulled fiber storage tray 50. The pillars 25 and 26 are arranged near one end of the main body 20 in the vertical direction, where the optical fiber cable is stripped, and the pillars 27 and 28 are arranged near the other end of the main body 20 in the vertical direction, where the optical fiber cable is stripped. The pillars 25 and 26 are arranged side by side in the horizontal direction of the main body 20. The pillars 27 and 28 are arranged side by side in the horizontal direction of the main body 20. The pillars 25, 26, 27, and 28 have planar shapes such as semi-ovals. The pillars 25, 26, 27, and 28 have flat top surfaces 25a, 26a, 27a, and 28a, respectively. The top surfaces 25a, 26a, 27a, and 28a come into contact with the recess 15a of the lid portion 10 (see FIG. 4).

[0038] Fig. 12 is a diagram showing a portion of a cross section taken along line XII-XII in Fig. 9, and includes cross sections of column portions 26, 28. As shown in Fig. 12, a recess 29c is formed in the region of back surface 29 of main body portion 20 that overlaps with column portion 26. A recess 29d is formed in the region of back surface 29 of main body portion 20 that overlaps with column portion 28. As a result, the interiors of column portions 26, 28 are hollowed out, and the thickness of the portions of column portions 26, 28 that form top surfaces 26a, 28a is approximately equal to the thickness of the portion of main body portion 20 that forms bottom surface 20b.

[0039] The main body 20 further has a plurality of accommodating grooves 201. Each of the plurality of accommodating grooves 201 accommodates a cylindrical adapter provided at the end of an optical fiber cable introduced from the optical fiber introduction port 9 (see FIGS. 1 and 2). Some of the plurality of accommodating grooves 201 are formed side by side in the horizontal direction along one end face in the vertical direction of the main body 20, and the remaining plurality of accommodating grooves 201 are formed side by side in the horizontal direction along the other end face in the vertical direction of the main body 20. The plurality of accommodating grooves 201 are respectively connected to the plurality of cutout portions 9b that form the optical fiber introduction port 9 shown in FIGS. 1 and 2.

[0040] The main body 20 further has a plurality of screw holes 202 formed along the periphery. Screws 35 (see FIGS. 1 and 2) inserted into the holes 14 of the lid 10 are threadedly engaged with the screw holes 202. This securely fastens the lid 10 to the main body 20.

[0041] The main body 20 further has a gasket receiving groove 203 formed inside the multiple screw holes 202. The gasket receiving groove 203 is formed around the entire circumference of the main body 20 so as to surround the recess having the bottom surface 20b. A rubber gasket 36 (see FIGS. 5 and 6) is embedded in the gasket receiving groove 203 to maintain watertightness of the space for receiving the optical fiber. In one example, the gasket 36 is made of ethylene propylene diene rubber (EDPM). The watertightness of the optical fiber introduction port 9 is ensured by a seal member provided on the outer surface of the optical fiber cable being sandwiched and compressed between the lid 10 and the main body 20 by tightening the screws 35. Furthermore, by integrating the seal member on the outer surface of the optical fiber cable and the gasket 36, the number of parts can be reduced.

[0042] FIG. 13 is a perspective view showing the appearance of the splicing fiber tray 40. The splicing fiber tray 40 is an example of a storage tray in this embodiment. The splicing fiber tray 40 is primarily made of, for example, resin. In one example, the splicing fiber tray 40 is made of polypropylene. As shown in FIG. 13, the splicing fiber tray 40 has a planar shape, such as a rectangle, and a plate-like appearance. The splicing fiber tray 40 has a flat mounting surface 42 on which optical fibers are placed, and guides 43, 44, 45, 46, and multiple guides 47 that are erected on the mounting surface 42 and guide the optical fibers. The guides 43 and 44 have a cylindrical shape with their central axes aligned with the thickness direction of the optical closure 1 and are arranged side by side at intervals in the vertical direction of the splicing fiber tray 40. The guides 43 and 44 ensure a bending radius of 15 mm or more for the optical fibers. The guide 45 has a planar shape, such as a circular arc shape, concentric with the guide 43. The guide 46 has a planar shape, such as a circular arc shape, concentric with the guide 44. The guides 45 and 46 are arranged side by side at intervals in the vertical direction of the splice fiber tray 40. The guides 43 and 44 are located between the guides 45 and 46 in the same direction. The plurality of guides 47 are arranged between the guides 43 and 44 in the vertical direction of the splice fiber tray 40. Each of the plurality of guides 47 extends along the vertical direction. The plurality of guides 47 are arranged in a direction intersecting the vertical direction. The plurality of guides 47 guide the fusion spliced portions of the optical fibers. In other words, the fusion spliced portions of the optical fibers are arranged in the gaps between the plurality of guides 47.

[0043] The connection fiber tray 40 has a first opening 42a and a first opening 42b. The first opening 42a is formed inside the guide 43 and allows the pillar portion 21 (see FIG. 9) to pass through. The first opening 42b is formed inside the guide 44 and allows the pillar portion 22 (see FIG. 9) to pass through. The first openings 42a and 42b have shapes corresponding to the cross-sectional shapes of the pillar portions 21 and 22, for example, circular shapes.

[0044] The connection fiber tray 40 further includes second openings 42c and 42d. The second openings 42c and 42d are formed outside the guides 43 and 44 and allow the pillars 23 and 24 (see FIG. 9 ) to pass through. The second openings 42c and 42d have shapes, such as circular shapes, that correspond to the cross-sectional shapes of the pillars 23 and 24. The second openings 42c and 42d are aligned along the vertical direction of the connection fiber tray 40 and are formed between the guides 43 and 44. In this direction, multiple guides 47 are located between the second openings 42c and 42d.

[0045] The splicing core tray 40 further has a plurality of presser plates 48 that press the optical fibers. The presser plates 48 are protrusions that extend along the mounting surface 42 from the tops of the guides 43, 44, 45, and 46 and the tops of a pair of side plates aligned in the vertical direction of the splicing core tray 40, and presser plates 48 to prevent the optical fibers arranged between them and the mounting surface 42 from floating. The first openings 42a and 42b and the second openings 42c and 42d are formed in positions that avoid these presser plates 48.

[0046] FIG. 14 is a perspective view showing the appearance of the through-hole fiber storage tray 50. The through-hole fiber storage tray 50 is another example of a storage tray in this embodiment. The through-hole fiber storage tray 50 is primarily made of, for example, resin. In one example, the through-hole fiber storage tray 50 is made of polypropylene. As shown in FIG. 13, the through-hole fiber storage tray 50 has a planar shape, such as an oval, and a plate-like appearance. The through-hole fiber storage tray 50 has a flat mounting surface 52 on which optical fibers are placed, and guides 53, 54, and 55 that are erected on the mounting surface 52 and guide the optical fibers. The guides 53 and 54 are cylindrical with their central axes aligned with the thickness direction of the optical closure 1 and are arranged side by side at intervals in the vertical direction of the through-hole fiber storage tray 50. The guide 55 is provided along the outer edge of the through-hole fiber storage tray 50 to surround the mounting surface 52.

[0047] The pull-through fiber optic storage tray 50 has first openings 52a and 52b. The first opening 52a is formed inside the guide 53, communicates with the first opening 42a of the splicing fiber optic tray 40, and allows the pillar 21 (see FIG. 9) to pass through. The first opening 52b is formed inside the guide 54, communicates with the first opening 42b of the splicing fiber optic tray 40, and allows the pillar 22 (see FIG. 9) to pass through. The first openings 52a and 52b have shapes corresponding to the cross-sectional shapes of the pillars 21 and 22, for example, circular shapes.

[0048] The through-hole fiber reserve tray 50 further has second openings 52c and 52d. The second openings 52c and 52d are formed outside the guides 53 and 54, communicate with the second openings 42c and 42d of the splice fiber tray 40, respectively, and allow the pillars 23 and 24 (see FIG. 9) to pass through. The second openings 52c and 52d have shapes corresponding to the cross-sectional shapes of the pillars 23 and 24, for example, circular shapes. The second openings 52c and 52d are aligned along the vertical direction of the through-hole fiber reserve tray 50 and are formed between the guides 53 and 54.

[0049] The pulled-through core fiber storage tray 50 further has a plurality of pressure plates 58 that press down the optical fibers. The plurality of pressure plates 58 are protrusions that extend from the tops of the guides 53, 54, 55 along the mounting surface 52, and prevent the optical fibers arranged between them and the mounting surface 52 from floating. The first openings 52a, 52b and the second openings 52c, 52d are formed at positions that avoid these pressure plates 58.

[0050] FIG. 15 is a perspective view showing the appearance of the tray protection sheet 60. The tray protection sheet 60 is a sheet placed between the pulled-through fiber storage tray 50 and the lid 10. The planar shape of the tray protection sheet 60 is the same as that of the pulled-through fiber storage tray 50. The tray protection sheet 60 is provided to protect the optical fibers stored in the pulled-through fiber storage tray 50 and prevent them from falling out. The tray protection sheet 60 is made of, for example, a transparent or translucent resin. In one example, the tray protection sheet 60 is made of polypropylene. The tray protection sheet 60 has openings 62a, 62b, 62c, and 62d. The opening 62a communicates with the first opening 42a of the splice fiber tray 40 and the first opening 52a of the pulled-through fiber storage tray 50, and allows the column 21 (see FIG. 9) to pass through. The opening 62b communicates with the first opening 42b of the splicing core wire tray 40 and the first opening 52b of the pulling-through core wire storage tray 50, and allows the pillar 22 (see FIG. 9) to pass through. The opening 62c communicates with the second opening 42c of the splicing core wire tray 40 and the second opening 52c of the pulling-through core wire storage tray 50, and allows the pillar 23 (see FIG. 9) to pass through. The opening 62d communicates with the second opening 42d of the splicing core wire tray 40 and the second opening 52d of the pulling-through core wire storage tray 50, and allows the pillar 24 (see FIG. 9) to pass through. The openings 62a, 62b, 62c, and 62d have shapes, for example, circles, that correspond to the cross-sectional shapes of the pillars 21, 22, 23, and 24, respectively.

[0051] 16 and 17 are diagrams showing examples of how the optical fiber F is routed in the splicing core tray 40. Fig. 16 is a diagram showing the longest allowable routing path of the optical fiber F when the optical fiber F is routed once around the splicing core tray 40. Fig. 17 is a diagram showing the shortest allowable routing path of the optical fiber F when the optical fiber F is routed once around the splicing core tray 40. As shown in Figs. 16 and 17, the optical fiber F is routed inside the splicing core tray 40 while being guided by guides 43, 44, 45, and 46.

[0052] The effects obtained by the optical closure 1 of this embodiment described above will be described. In the optical closure 1 of this embodiment, the space within the housing 2 that houses the optical fiber F is formed by the metal main body 20 and the metal lid 10. Therefore, mechanical strength can be improved compared to conventional optical closures 1 that are mainly made of resin. In addition, the housing 2 of this optical closure 1 has metal pillars 21 to 28. The pillars 21 to 28 are located between the main body 20 and the lid 10 within the space and support the lid 10. Therefore, deformation of the lid 10 due to a force from above when a pedestrian or vehicle passes over the optical closure 1 can be suppressed. Therefore, the optical closure 1 can have sufficient mechanical strength when installed on a road surface.

[0053] The deformation and stress of the cover 10 and the main body 20 when a force of 30 kN was applied uniformly from above the optical closure 1 were calculated by simulation. The maximum displacement and maximum stress of the cover 10 were 0.19 mm and 130 MPa, respectively, and the maximum displacement and maximum stress of the main body 20 were 0.40 mm and 136 MPa, respectively, which were both acceptable values. 2 The deformation and stress of the lid portion 10 and the main body portion 20 when a force of 1 MPa in total was applied were determined by simulation, and the maximum displacement and maximum stress of the lid portion 10 were 0.32 mm and 210 MPa, respectively, and the maximum displacement and maximum stress of the main body portion 20 were 0.44 mm and 147 MPa, respectively, which were both acceptable values.

[0054] As in this embodiment, the lid portion 10 may have a first surface 15 facing the main body portion 20, a second surface 11 facing away from the first surface 15, and ribs 12, 13 that are provided on the second surface 11 and have a mesh-like planar shape. By providing the mesh-like ribs 12, 13 on the lid portion 10, the mechanical strength of the lid portion 10 can be further increased and deformation of the lid portion 10 due to a force from above can be further suppressed. In addition, by providing the mesh-like ribs 12, 13 on the second surface 11, they can also serve as a non-slip surface for pedestrians and the like.

[0055] As in the present embodiment, the lid 10 may have a first portion 10a including a recess 15a provided in the first surface 15 and forming a space for accommodating an optical fiber, and a second portion 10b provided around the first portion 10a, in contact with the main body 20, and fixed to the main body 20. The second surface 11 of the second portion 10b may be located closer to the main body 20 than the second surface 11 of the first portion 10a, and a height H2 of the rib 13 provided on the second surface 11 of the second portion 10b from the second surface 11 may be greater than a height H1 of the rib 12 provided on the second surface 11 of the first portion 10a from the second surface 11. In this case, the space for accommodating the optical fiber F can be secured by the first portion 10a. Furthermore, the mechanical strength of the lid 10 can be further improved by increasing the height of the rib 13 provided around the first portion 10a.

[0056] As in this embodiment, the splice fiber tray 40 may have a first opening 42a formed inside the guide 43 to allow the pillar 21 to pass through, and a first opening 42b formed inside the guide 44 to allow the pillar 22 to pass through. Also, the pulled-through fiber reserve tray 50 may have a first opening 52a formed inside the guide 53 to allow the pillar 21 to pass through, and a first opening 52b formed inside the guide 54 to allow the pillar 22 to pass through. In these cases, the spaces created inside the guides 43, 44, 53, and 54 can be effectively used as the pillars 21 and 22, thereby improving space utilization efficiency.

[0057] As in this embodiment, the housing 2 may have a plurality of pillars 21 to 28. The connection core wire tray 40 may have a second opening 42c formed outside the guides 43, 44 to allow the pillar 23 to pass through, and a second opening 42d formed outside the guides 43, 44 to allow the pillar 24 to pass through. The pulled-through core wire storage tray 50 may have a second opening 52c formed outside the guides 53, 54 to allow the pillar 23 to pass through, and a second opening 52d formed outside the guides 53, 54 to allow the pillar 24 to pass through. The cross-sectional areas of the pillars 21, 22 in a cross section perpendicular to the thickness direction may be larger than the cross-sectional areas of the pillars 23, 24 in a cross section perpendicular to the thickness direction. In this way, by making the cross-sectional area of the pillars 23, 24 arranged outside the guides 43, 44, 53, 54 smaller than the cross-sectional area of the pillars 21, 22 arranged inside the guides 43, 44, 53, 54, it is possible to reduce the obstruction caused by the pillars 23, 24 to the routing of the optical fiber F within the connection core tray 40 and the pulled-through core tray 50.

[0058] As in this embodiment, the connection fiber tray 40 may have second openings 42c, 42d formed outside the guides 43, 44 to allow the pillars 23, 24 to pass through. Also, the pulled fiber reserve tray 50 may have second openings 52c, 52d formed outside the guides 53, 54 to allow the pillars 23, 24 to pass through. In this way, even when the pillars are arranged outside the guides 43, 44, 53, 54, it is possible to provide an optical closure 1 that has sufficient mechanical strength when installed on a road surface.

[0059] As in this embodiment, the pillars 21 to 28 may be integral with the main body 20, and the top surfaces 21a to 28a of the pillars 21 to 28 may abut against the lid 10. In this case, the number of parts of the optical closure 1 can be reduced, making assembly easier.

[0060] As in this embodiment, the top surfaces 21a to 28a of the pillar portions 21 to 28 may be flat. In this case, the contact area between the lid portion 10 and the pillar portions 21 to 28 can be increased, thereby reducing stress concentration.

[0061] As in this embodiment, the housing 2 has a plurality of pillars 21 to 28, and one or more pillars (four pillars 25, 26, 27, and 28 in this embodiment) may be provided outside the connection fiber tray 40 and the pulled fiber reserve tray 50. In this way, even when pillars are arranged outside the connection fiber tray 40 and the pulled fiber reserve tray 50, an optical closure 1 can be provided that has sufficient mechanical strength when installed on the road surface.

[0062] The optical closure according to the present disclosure is not limited to the above-described embodiment, and various other modifications are possible. For example, in the above embodiment, the columnar shapes of the columnar portions 21, 22, 23, and 24 are illustrated as being cylindrical, but the columnar shapes are not limited to cylindrical shapes and may be various other shapes, such as triangular prisms, quadrangular prisms, and polygonal prisms. Furthermore, in the above embodiment, the optical closure 1 includes multiple columnar portions 21 to 28. However, the effects of the above embodiment can be achieved by including at least one columnar portion in the optical closure 1. Furthermore, in the above embodiment, the optical closure 1 includes two storage trays (the connection core wire tray 40 and the pulled core wire holding tray 50). However, the optical closure may include one storage tray, or three or more storage trays. [Explanation of symbols]

[0063] 1...Optical closure 2. Housing 9...Optical fiber inlet 9a, 9b...Notch 10…Lid part 10a...first part 10b…Second part 11…Second side 12,13...Ribs 12a,12b…side 12c,12d...end face 14...hole 15…Side 1 15a...recess 20...Main body 20a…area 20b…Bottom surface 21,22,23,24,25,26,27,28...Column part 21a, 22a, 23a, 24a, 25a, 26a, 27a, 28a...Top surface 29…Back side 29a, 29b, 29c, 29d...recesses 31, 32, 33...Fiber optic cable 34...Optical fiber bundle 35,37...Screws 36...Gasket 40...Connection core tray 41...Bearing part 42...Placement surface 42a, 42b…first opening 42c, 42d…Second opening 43, 44, 45, 46, 47… Guide 48...Pressing plate 50...Pulling-through core wire storage tray 51...Rotation axis 52...Placement surface 52a, 52b…first opening 52c, 52d…Second opening 53, 54, 55... Guide 58...Pressing plate 60...Tray protection sheet 62a, 62b, 62c, 62d...opening 201... Storage groove 202...Screw hole 203...Gasket receiving groove 211...Rib F...Optical fiber

Claims

1. An optical closure for housing an optical fiber, comprising: a housing having a metal main body and a metal lid facing the main body in a predetermined direction, the housing having a space for accommodating the optical fiber and an inlet for introducing the optical fiber into the space between the main body and the lid; a storage tray disposed in the space of the housing, the storage tray having a mounting surface on which the optical fiber is mounted and a cylindrical guide provided on the mounting surface for guiding the optical fiber; Equipped with the housing further includes at least one metal pillar portion that is provided between the main body portion and the lid portion in the space and supports the lid portion; The storage tray has a first opening formed inside the guide for allowing the post to pass through.

2. An optical closure for housing an optical fiber, comprising: a housing having a metal main body and a metal lid facing the main body in a predetermined direction, the housing having a space for accommodating the optical fiber and an inlet for introducing the optical fiber into the space between the main body and the lid; a storage tray disposed in the space of the housing, the storage tray having a mounting surface on which the optical fiber is mounted and a guide provided on the mounting surface for guiding the optical fiber; Equipped with the housing further includes a plurality of metal pillars that are provided between the main body and the lid in the space and support the lid, The storage tray has a first opening formed inside the guide and through which the pillar portion passes, and a second opening formed outside the guide and through which another pillar portion passes, An optical closure, wherein the cross-sectional area of the pillar portion passing through the first opening in a cross section perpendicular to the specified direction is larger than the cross-sectional area of the other pillar portion passing through the second opening in a cross section perpendicular to the specified direction.

3. The lid portion is a first surface facing the main body; a second surface facing away from the first surface; a rib provided on the second surface and having a mesh-like planar shape; 3. An optical closure according to claim 1 or claim 2, comprising:

4. The lid portion is a first portion including a recess provided on the first surface and forming the space; a second portion provided around the first portion, in contact with the main body portion, and fixed to the main body portion; and the second surface of the second portion is located closer to the main body portion than the second surface of the first portion, 4. An optical closure as described in claim 3, wherein the height of the ribs provided on the second surface of the second part from the second surface is greater than the height of the ribs provided on the second surface of the first part from the second surface.

5. the post portion is integral with the body portion; The optical closure of claim 1 , wherein a top surface of the post abuts against the lid.

6. The optical closure of claim 5 , wherein the top surfaces of the posts are flat.

7. the housing has a plurality of the pillars, 2. The optical closure of claim 1, wherein one or more of the posts are provided on the exterior of the storage tray.

8. The plurality of pillar portions are integral with the main body portion, The optical closure according to claim 2 , wherein top surfaces of the plurality of posts abut against the lid.

9. An optical closure as described in Claim 8, wherein the top surfaces of the multiple pillar portions are flat.

10. An optical closure as described in claim 2, wherein one or more of the pillar portions are provided on the outside of the storage tray.

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