JP7723901B2 - Optical Closure - Google Patents

Description

This disclosure relates to optical closures.

Patent Document 1 discloses an optical cable connection closure that connects an optical cable and a drop cable in an aerial configuration. The optical cable connection closure includes a closure body. The closure body has a cable housing section and a cable inlet for introducing the optical cable and drop cable into the cable housing section.

Patent Document 2 discloses an optical fiber cable connection closure. The optical fiber cable connection closure has a closure body, an optical cable lead-in/out port, a drop cable lead-in/out port, and a connection portion housing tray arranged within the closure body. The optical fiber lead-in/out port leads out or introduces an aerial optical cable. The drop cable lead-in/out port leads out or introduces a drop cable. The connection portion housing tray connects the optical fiber core drawn out from the optical cable to the drop cable.

Japanese Patent Application Laid-Open No. 2007-47336 JP 2012-123245 A

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 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.

As a result, it is conceivable to lay optical fiber cables on the road surface. In this case, the optical closure installed midway along the optical fiber cable will also be installed on the road surface, so the optical closure must have sufficient mechanical strength to prevent pedestrians and vehicles from affecting the optical fiber inside when passing over the closure. The purpose of this disclosure is to provide an optical closure that has sufficient mechanical strength when installed on the road surface.

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 pillar provided between the main body and the lid in the space to support the lid.

This disclosure provides an optical closure that has sufficient mechanical strength when installed on a road surface.

FIG. 1 is a perspective view showing the appearance of an optical closure according to an embodiment of the present disclosure. 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. FIG. 3 is a perspective view showing the appearance of the lid portion. FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. FIG. 5 is a perspective view showing a state in which the cover is removed from the optical closure. FIG. 6 is a perspective view showing the optical closure shown in FIG. 5 with the pull-through fiber cable holding tray open. FIG. 7 is an enlarged perspective view of a part of FIG. FIG. 8 is an enlarged perspective view showing the attachment portion of the pulled-through fiber conductor storage tray to the splice fiber conductor tray. FIG. 9 is a perspective view showing the appearance of the main body and the column. FIG. 10 is a diagram showing a part of a cross section taken along line XX in FIG. FIG. 11 is an enlarged view of a part of the rear surface of the main body. FIG. 12 is a view showing a part of a cross section taken along line XII-XII in FIG. FIG. 13 is a perspective view showing the appearance of the connecting core wire tray. FIG. 14 is a perspective view showing the appearance of the through-hole fiber holding tray. FIG. 15 is a perspective view showing the appearance of the tray protection sheet. FIG. 16 is a diagram showing an example of how optical fibers are routed in a connection core tray. FIG. 17 is a diagram showing an example of how optical fibers are routed in a connection core tray.

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

[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.

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. This allows for improved mechanical strength compared to conventional optical closures that are primarily 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. This makes it possible to prevent deformation of the lid due to forces from above when a pedestrian or vehicle passes over the optical closure. Therefore, this optical closure has sufficient mechanical strength when installed on the road surface.

[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 that has a mesh (lattice) planar shape. Having the mesh rib on the lid further increases the mechanical strength of the lid and further reduces deformation of the lid due to forces from above. Additionally, having the mesh rib on the second surface can also serve as a non-slip surface for pedestrians and the like.

[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 that is provided around the first portion, contacts the main body portion, and is 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 the height of the rib provided on the second surface of the second portion from the second surface may be greater than the height of the rib provided on the second surface of the first portion from the second surface. In this case, the first portion can provide space for storing the optical fiber. Furthermore, the mechanical strength of the lid can be further improved by raising the rib provided around the first portion.

[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 pillar portion to pass through. In this case, the space created inside the guide can be effectively used as the pillar portion, thereby improving space utilization efficiency.

[5] In the optical closure of [4] above, the housing may have multiple pillars. The storage tray may further have a second opening formed outside the guide to allow another pillar to pass through. 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 optical fiber within the storage tray.

[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 can be provided that has sufficient mechanical strength when installed on a road surface.

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

[8] In the optical closure described in [7] above, the top surface of the column may be flat. In this case, the contact area between the lid and the column can be increased, reducing stress concentration.

[9] In the optical closure of any one of [1] to [8] above, the housing may have a plurality of posts, one or more of which may be provided on the outside of the storage tray. In this way, even if the posts 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 embodiment of the present disclosure]

Specific examples of optical closures according to embodiments of the present disclosure are 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 that are equivalent in meaning and scope to the claims. In the following description, identical elements in the drawings will be designated by the same reference numerals, and duplicate explanations will be omitted.

1 is a perspective view showing the appearance of an optical closure 1 according to one embodiment of the present disclosure. Portion 2-A of FIG. 2 is a plan view of the optical closure 1. Portion 2-B of FIG. 2 is a front view of the optical closure 1. Portion 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 excess optical fiber. Unlike typical optical closures that are installed aerial, it 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 portions 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.

As shown in Figures 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 primarily made of stainless steel, and in another example, the lid portion 10 and the main body portion 20 are primarily 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 multiple (ten in the illustrated example) screws 35. The multiple screws 35 are arranged in a row along the periphery of the lid portion 10.

Multiple 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 interior of 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 contains multiple optical fibers. In the following description, optical fiber primarily refers to an optical fiber core.

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

The lid portion 10 has a first surface 15 (see Figure 4) facing the main body portion 20, and a second surface 11 facing away from the first surface 15. The normal direction of the first surface 15 and the second surface 11 coincides 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.

The first portion 10a includes a recess 15a provided on the first surface 15, thereby forming a space inside the housing 2 for storing an optical fiber. The second surface 11 of the first portion 10a is provided with ribs 12 having a mesh-like planar shape. The ribs 12 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 provided with ribs 13 having a mesh-like planar shape. 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 the height H2 of the ribs 13 relative to the second surface 11 of the second portion 10b is greater than the 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, based on the back surface of optical closure 1 (i.e., the back surface of main body 20). In other words, the difference between height H1 of rib 12 based on second surface 11 of first portion 10a and height H2 of rib 13 based on second surface 11 of second portion 10b is equal to the difference between heights of second surface 11 of first portion 10a and second surface 11 of second portion 10b, based on the back surface of optical closure 1.

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

Figure 5 is a perspective view showing the optical closure 1 with the lid 10 removed. Figure 6 is a perspective view showing the optical closure 1 shown in Figure 5 with the pull-through fiber optic storage tray 50 open. Figure 7 is a perspective view showing an enlarged portion of Figure 6. As shown in Figures 5, 6, and 7, the optical closure 1 of this embodiment further includes, in addition to the lid 10 and main body 20, columns 21 to 28, a gasket 36, a splicing fiber tray 40, a pull-through fiber optic storage tray 50, and a tray protective sheet 60. The columns 21 to 28, the splicing fiber tray 40, the pull-through fiber optic 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 pull-through core wire storage tray 50 is placed on the splicing core wire tray 40 and is attached so as to be able to open and close relative to the splicing core wire tray 40. The tray protection sheet 60 is placed on the pull-through core wire storage tray 50.

Figure 8 is an enlarged perspective view showing the attachment portion of the pull-through core wire storage tray 50 to the splicing core wire tray 40. The pull-through core wire storage 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 core wire storage tray 50, and their central axes extend along the vertical direction. The splicing core wire 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 core wire storage tray 50 to be opened and closed relative to the splicing core wire tray 40. Note that, as shown in Figure 13, bearings 41 are provided on both of the pair of vertically extending side surfaces of the splicing core wire tray 40. As a result, the rotating shafts 51 can be attached to either of the pair of side surfaces of the splicing core wire tray 40.

Figure 9 is a perspective view showing the appearance of the main body 20 and column sections 21 to 28. As shown in Figure 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 in the lid 10, forms a space for storing optical fiber. 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 splice fiber tray 40 and the pulled fiber storage tray 50, which will be described later.

The pillars 21 to 28 are made of metal and are disposed within the space that houses the optical fiber. They 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 primarily made of stainless steel. In another example, the pillars 21 to 28 are primarily 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 block of metal. 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.

The pillars 21 and 22 are arranged on the region 20a. The pillars 21 and 22 are cylindrical with their central axis aligned in the thickness direction of the optical closure 1, and are arranged 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 planar shapes of the top surfaces 21a and 22a are circular. The top surfaces 21a and 22a abut against the recess 15a of the lid 10 (see Figure 4). The diameters of the pillars 21 and 22 are greater than the height of the pillars 21 and 22 relative to the bottom surface 20b (in other words, the distance between the bottom surface 20b and the top surfaces 21a and 22a).

The pillars 23 and 24 are also arranged on the region 20a. The pillars 23 and 24 are cylindrical with their central axis aligned in the thickness direction of the optical closure 1. They are arranged side by side at a distance from each other in the vertical direction of the main body 20, and are also arranged 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 a circular planar shape. The top surfaces 23a and 24a abut against the recess 15a of the lid 10 (see Figure 4). The diameters of the pillars 23 and 24 are smaller than the height of the pillars 23 and 24 relative to the bottom surface 20b (in other words, the distance 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.

Figure 10 is a diagram showing a portion of a cross section taken along line X-X in Figure 9, including cross sections of column portions 21, 22, 23, and 24. As shown in Figure 10, a recess 29a is formed in the area of the back surface 29 of the main body 20 that overlaps with column portion 21. A recess 29b is formed in the area of the back surface 29 of the main body 20 that overlaps with column portion 22. As a result, the interiors of column portions 21 and 22 are hollowed out, and the thickness of the portions of column 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 20 that forms the bottom surface 20b. On the other hand, no recess is formed in the areas of the back surface 29 of the main body 20 that overlap with column portions 23 and 24, and the back surface 29 is flat in these areas. Therefore, column portions 23 and 24 are formed solid.

In addition, ribs 211 are provided in recesses 29a and 29b. The ribs 211 protrude from the bottom surfaces of recesses 29a and 29b in the direction of the normal vector of the bottom surfaces. Figure 11 is an enlarged view of a portion of the back surface 29, showing the planar shape of the ribs 211. As shown in Figure 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 back surface 29 excluding recesses 29a and 29b. In other words, the height of the ribs 211 relative to the bottom surfaces of recesses 29a and 29b is equal to the depth of recesses 29a and 29b.

Referring again to Figure 9, the pillars 25, 26, 27, and 28 are arranged outside the area 20a, i.e., outside the splice fiber tray 40 and the pull-through 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. Top surfaces 25a, 26a, 27a, and 28a abut against recess 15a of lid 10 (see Figure 4).

Figure 12 is a diagram showing a portion of a cross section taken along line XII-XII in Figure 9, including a cross section of column portions 26, 28. As shown in Figure 12, a recess 29c is formed in the area of the back surface 29 of the main body 20 that overlaps with column portion 26. A recess 29d is formed in the area of the back surface 29 of the main body 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 the main body 20 that forms bottom surface 20b.

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 the optical fiber cable introduced through the optical fiber introduction port 9 (see Figures 1 and 2). Some of the plurality of accommodating grooves 201 are formed in a row in the horizontal direction along one end face in the vertical direction of the main body 20, while the remaining plurality of accommodating grooves 201 are formed in a row 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 each connected to a plurality of cutout portions 9b that form the optical fiber introduction port 9 shown in Figures 1 and 2.

The main body 20 further has multiple screw holes 202 formed along its periphery. Screws 35 (see Figures 1 and 2) inserted through holes 14 in the lid 10 thread into the screw holes 202. This firmly secures the lid 10 to the main body 20.

The main body 20 further includes 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, surrounding the recess having the bottom surface 20b. A rubber gasket 36 (see Figures 5 and 6) is embedded in the gasket receiving groove 203 to maintain the watertightness of the space that stores 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 the sealing 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 sealing member on the outer surface of the optical fiber cable with the gasket 36, the number of parts can be reduced.

Figure 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 Figure 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 with a gap between them 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 an arc shape concentric with the guide 43. The guide 46 has a planar shape, such as an arc shape concentric with the guide 44. Guides 45 and 46 are arranged side by side at a distance from each other in the vertical direction of the splice fiber tray 40. Guides 43 and 44 are located between guides 45 and 46 in the same direction. Multiple guides 47 are arranged between guides 43 and 44 in the vertical direction of the splice fiber tray 40. Each of the multiple guides 47 extends along the vertical direction. The multiple guides 47 are lined up in a direction intersecting the vertical direction. The multiple 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 multiple guides 47.

The connection core 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 Figure 9) to pass through. The first opening 42b is formed inside the guide 44 and allows the pillar portion 22 (see Figure 9) to pass through. The first openings 42a and 42b have a shape that corresponds to the cross-sectional shape of the pillar portions 21 and 22, for example, a circular shape.

The connection fiber tray 40 further has second openings 42c and 42d. The second openings 42c and 42d are formed on the outside of the guides 43 and 44 and allow the pillars 23 and 24 (see Figure 9) to pass through, respectively. The second openings 42c and 42d have shapes, such as circular, 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.

The splice fiber tray 40 also has multiple pressure plates 48 that press down on the optical fibers. The multiple pressure 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 that are aligned in the vertical direction of the splice fiber tray 40, and 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 pressure plates 48.

Figure 14 is a perspective view showing the appearance of the through-hole fiber retention tray 50. The through-hole fiber retention tray 50 is another example of a storage tray in this embodiment. The through-hole fiber retention tray 50 is primarily made of, for example, resin. In one example, the through-hole fiber retention tray 50 is made of polypropylene. As shown in Figure 13, the through-hole fiber retention tray 50 has a planar shape, such as an oval, and a plate-like appearance. The through-hole fiber retention 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 retention tray 50. The guide 55 is arranged along the outer edge of the through-hole fiber retention tray 50, surrounding the mounting surface 52.

The pull-through fiber conductor storage tray 50 has a first opening 52a and a first opening 52b. The first opening 52a is formed inside the guide 53, communicates with the first opening 42a of the splice fiber conductor tray 40, and allows the pillar 21 (see Figure 9) to pass through. The first opening 52b is formed inside the guide 54, communicates with the first opening 42b of the splice fiber conductor tray 40, and allows the pillar 22 (see Figure 9) to pass through. The first openings 52a and 52b have a shape that corresponds to the cross-sectional shape of the pillars 21 and 22, for example, a circular shape.

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, respectively, of the splice fiber tray 40, and allow the pillars 23 and 24 (see Figure 9) to pass through. The second openings 52c and 52d have shapes that correspond to the cross-sectional shapes of the pillars 23 and 24, for example, circular. 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.

The pull-through fiber storage tray 50 also has multiple pressure plates 58 that hold down the optical fiber. The multiple pressure plates 58 are protrusions that extend from the tops of the guides 53, 54, and 55 along the mounting surface 52, and prevent the optical fiber arranged between them and the mounting surface 52 from floating. The first openings 52a and 52b and the second openings 52c and 52d are formed in positions that avoid these pressure plates 58.

Figure 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 pull-through core wire storage tray 50 and the lid 10. The planar shape of the tray protection sheet 60 is the same as that of the pull-through core wire storage tray 50. The tray protection sheet 60 is provided to protect the optical fibers stored in the pull-through core wire storage tray 50 and prevent them from popping 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. Opening 62a communicates with the first opening 42a of the splice core wire tray 40 and the first opening 52a of the pull-through core wire storage tray 50, and allows the column portion 21 (see Figure 9) to pass through. Opening 62b communicates with first opening 42b of splicing core tray 40 and first opening 52b of pull-through core tray 50, allowing pillar 22 (see FIG. 9) to pass through. Opening 62c communicates with second opening 42c of splicing core tray 40 and second opening 52c of pull-through core tray 50, allowing pillar 23 (see FIG. 9) to pass through. Opening 62d communicates with second opening 42d of splicing core tray 40 and second opening 52d of pull-through core tray 50, allowing pillar 24 (see FIG. 9) to pass through. Openings 62a, 62b, 62c, and 62d have shapes corresponding to the cross-sectional shapes of pillars 21, 22, 23, and 24, respectively, such as circular shapes.

Figures 16 and 17 are diagrams showing examples of how optical fiber F is routed in the splicing core tray 40. Figure 16 is a diagram showing the longest allowable routing path for optical fiber F when it is wound around the splicing core tray 40. Figure 17 is a diagram showing the shortest allowable routing path for optical fiber F when it is wound around the splicing core tray 40. As shown in Figures 16 and 17, the optical fiber F is routed within the splicing core tray 40 while being guided by guides 43, 44, 45, and 46.

The effects achieved by the optical closure 1 of this embodiment described above will now be explained. 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. This allows for improved mechanical strength compared to conventional optical closures 1 that are primarily 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. This prevents deformation of the lid 10 due to forces from above when a pedestrian or vehicle passes over the optical closure 1. This allows the optical closure 1 to have sufficient mechanical strength when installed on a road surface.

The deformation and stress of the lid portion 10 and the main body portion 20 when a force of 30 kN was applied evenly from above the optical closure 1 were determined by simulation. The maximum displacement and maximum stress of the lid portion 10 were 0.19 mm and 130 MPa, respectively, and the maximum displacement and maximum stress of the main body portion 20 were 0.40 mm and 136 MPa, respectively, which were both acceptable values. Furthermore, the deformation and stress of the lid portion 10 and the main body portion 20 when a force of 1 N/ ^mm2 (1 MPa in total) was applied from above the optical closure 1 were determined by simulation. 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.

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 provided on the second surface 11 and having 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 forces 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.

As in this embodiment, the lid 10 may have a first portion 10a that includes a recess 15a on the first surface 15 and forms a space for storing the optical fiber, and a second portion 10b that is provided around the first portion 10a, contacts the main body 20, and is 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 the 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 the 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 storing 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.

As in this embodiment, the connection core 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. The pull-through core tray 50 may also 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 space created inside the guides 43, 44, 53, and 54 can be effectively used as the pillars 21 and 22, improving space utilization efficiency.

As in this embodiment, the housing 2 may have multiple pillars 21 to 28. The connection core 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 pull-through core 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 area of the pillars 21, 22 in a cross section perpendicular to the thickness direction may be larger than the cross-sectional area 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 and 24 arranged on the outside of the guides 43, 44, 53, and 54 smaller than the cross-sectional area of the pillars 21 and 22 arranged on the inside of the guides 43, 44, 53, and 54, it is possible to reduce the interference caused by the pillars 23 and 24 with the routing of the optical fiber F within the connection fiber tray 40 and the pulled-through fiber tray 50.

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. Furthermore, the pull-through fiber 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 located outside the guides 43, 44, 53, 54, an optical closure 1 can be provided that has sufficient mechanical strength when installed on the road surface.

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

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

As in this embodiment, the housing 2 has multiple 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 pull-through fiber reserve tray 50. In this way, even when pillars are located outside the connection fiber tray 40 and the pull-through fiber reserve tray 50, an optical closure 1 can be provided that has sufficient mechanical strength when installed on the road surface.

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 sections 21, 22, 23, and 24 were exemplified, but the columnar shapes are not limited to cylindrical shapes and various other shapes, such as triangular prisms, quadrangular prisms, and polygonal prisms, can be used. Furthermore, in the above embodiment, the optical closure 1 is illustrated as having multiple columnar sections 21 to 28, but the effects of the above embodiment can be achieved by having the optical closure 1 have at least one columnar section. Furthermore, in the above embodiment, the optical closure 1 is illustrated as having two storage trays (a connection fiber tray 40 and a pulled fiber storage tray 50), but the optical closure may have one storage tray, or three or more storage trays.

DESCRIPTION OF SYMBOLS 1...optical closure 2...housing 9...optical fiber introduction port 9a, 9b...cutout portion 10...lid portion 10a...first portion 10b...second portion 11...second surface 12, 13...ribs 12a, 12b...side surface 12c, 12d...end surface 14...hole 15...first surface 15a...recess 20...main body portion 20a...region 20b...bottom surface 21, 22, 23, 24, 25, 26, 27, 28...pillar portions 21a, 22a, 23a, 24a, 25a, 26a, 27a, 28a...top surface 29...back surface 29a, 29b, 29c, 29d...recess 31, 32, 33...optical fiber cable 34...optical fiber Fiber bundles 35, 37...Screws 36...Gasket 40...Connection core fiber tray 41...Bearing portion 42...Placement surfaces 42a, 42b...First openings 42c, 42d...Second openings 43, 44, 45, 46, 47...Guide 48...Pressure plate 50...Pulled core fiber storage tray 51...Rotating shaft 52...Placement surfaces 52a, 52b...First openings 52c, 52d...Second openings 53, 54, 55...Guide 58...Pressure plate 60...Tray protective sheet 62a, 62b, 62c, 62d...Opening 201...Accommodation groove 202...Screw hole 203...Gasket accommodating groove 211...Rib F...Optical fiber

Claims (10)

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 . 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. 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: 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. 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. The optical closure of claim 5 , wherein the top surfaces of the posts are flat. 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. the plurality of pillars are integral with the main body;
The optical closure according to claim 2 , wherein top surfaces of the plurality of posts abut against the lid. 9. The optical closure of claim 8, wherein the top surfaces of the plurality of posts are flat. 3. The optical closure of claim 2, wherein one or more of said posts are provided on the exterior of said storage tray.