JP2012159675A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve optical fiber connection with low loss by inserting an optical fiber which still has a coating into an optical connector, and aligning glass of the optical fiber inside an optical connector.SOLUTION: There is provided an optical connector which connects inner and outer coated optical fibers with elastic restoring force generated by deformation of the outer optical fiber as end faces of the optical fibers are pressed against each other. The optical connector includes: a ferrule 1 which houses the inner coated optical fiber; a space which is large enough to deform the outer coated optical fiber 5; and a flange 2 and an optical fiber grip part 3 which allow the inner optical fiber to pass through while still having the coating by inserting and extracting a wedge, and also grip the inner and outer coated optical fibers. The ferrule 1 includes: a glass array hole into which only glass parts of the optical fibers are inserted; a coated optical fiber array part which stores the coating part of the inner optical fiber; and a coating removal part 15 which stores the coating peeled at an entrance of the glass array hole when the inner optical fiber is pressed from a rear end of the optical connector while having the coating.

Description

  The present invention relates to an optical connector and an assembly tool used for assembling the optical connector.

  In the conventional connection between optical fibers such as mechanical splices and optical connectors consisting of glass and a coating covering the periphery of the glass, the outer peripheral surface in the axial direction of the glass of the optical fiber is used as a reference plane, and the glass of the optical fiber is used. By aligning the positions, a low-loss optical connection is realized. As an example, a general-purpose single-mode (SM) optical fiber is composed of a glass with an outer diameter of 0.125 mm and a coating covering the periphery of the glass. After removing the glass coating such as the inside of the optical connector housing In addition, it is used in a coated state except for a portion where the glass is not damaged. Therefore, when connecting optical fibers, the process of removing the coating | cover at the front-end | tip of an optical fiber and exposing glass is essential.

  There is an optical connector disclosed in Patent Document 1. FIG. 1 shows a schematic cross-sectional view of this optical connector. This optical connector includes a ferrule 1, a flange 2 that grips the ferrule at the rear end of the ferrule 1, an optical fiber gripping portion 3 that is connected to the rear end of the flange 2, and a housing 4. The coating at the tip of the optical fiber 5 is removed, the glass end face from which the coating has been removed is tapered, the optical fiber is inserted from the optical fiber gripping portion 3 of the optical connector, and the optical fiber 5 is elastically supported by the optical fiber gripping portion. It is a structure to hold. When holding the optical fiber elastically, the optical fiber bends inside the flange when the optical fibers are connected by holding the optical fiber glass tip protruding from the ferrule end face by about 100 μm to the outside of the optical connector. This is a structure in which the optical fiber end faces are connected to each other by PC (Physical Contact) with elastic restoring force. In the ferrule, the small-diameter hole 6 is positioned with an optical fiber from which the glass has been removed to expose the glass, and the optical fiber in the flange 2 and the optical fiber in the optical fiber gripping portion are elastically elastic. An optical fiber with a coating is positioned on the portion 8 to be held. Since the outer diameter of the ferrule and the inner diameter of the small-diameter hole 6 of the ferrule can be manufactured with the same dimensional accuracy as the outer diameter of the glass of the optical fiber, the inner diameter of the thin-hole 6 is the outer diameter of the glass. By making the diameter slightly larger than 125 mm and aligning the outer diameter of the ferrule with a split sleeve, the glass position of the fiber to be connected is aligned and a low-loss connection is realized.

JP 2009-192908 A

  In an optical fiber connection according to the prior art, for example, when using the optical connector described in Patent Document 1, it is necessary to remove the coating at the tip of the optical fiber and expose the glass, and then insert the optical fiber into the optical connector. there were. Since the optical fiber connection work is performed with the glass exposed, there is a risk that the exposed glass portion will break during the optical fiber connection work. If the optical fiber can be connected without removing the coating of the optical fiber, it is possible to prevent breakage of the optical fiber during the optical fiber connection work due to the exposure of the glass, and further, the connection work by omitting the coating removal process. Simplification can be realized.

  However, in the optical fiber connection, it is difficult to align the glass position of the optical fiber so that the loss is about the same as when the coating at the tip of the optical fiber is removed without removing the coating at the tip of the optical fiber. For example, the structure of the optical connector of Patent Document 1 is adopted, only the dimensions are changed, and a general-purpose SM fiber having a coating outer diameter of 0.25 mm and a glass outer diameter of 0.125 mm is removed from the tip of the optical fiber. Consider a case where a structure is used for connection without connection. In a general-purpose optical fiber, the allowable value of the outer diameter of the coating is 0.250 ± 0.015 mm, so the inner diameter of the narrow hole 6 of the ferrule 1 is 0.265 mm. Furthermore, in the general-purpose optical fiber, the eccentric amount at the center position in the cross section of the glass and the coating is allowed to be less than 0.0125 mm. That is, when aligning the optical fiber with the coated outer diameter, even if the inner diameter of the small-diameter hole 6 of the ferrule can be manufactured with the same accuracy as the outer diameter of the glass of the optical fiber, In the cut glass surface, there is a possibility that an axial deviation of the same distance as the diameter of the core occurs. That is, in the method of changing the dimensions of the optical connector structure described in Patent Document 1 and aligning the optical fiber on the outer peripheral surface in the axial direction of the coating, it is difficult to connect the optical fiber with low loss.

  From the above, without removing the coating, it is a problem to insert a coated optical fiber into the optical connector, align the glass of the optical fiber inside the optical connector, and realize a low-loss optical fiber connection. .

  The present invention has been made to solve the above problems. For optical fiber connection, a conventional optical connector is used in which the optical fiber is inserted into the optical connector without removing the optical fiber coating, and the optical fiber is inserted after removing the coating at the tip of the optical fiber to expose the glass. Provided is an optical connector that realizes a loss comparable to that of The optical connector of the present invention is an optical connector for connecting the physical contact by pressing the end faces of the optical fibers with the elastic restoring force generated by the bending of the optical fiber inside the optical connector, and only the glass portion of the optical fiber is inserted. A coating removal unit that accommodates a glass alignment hole having an inner diameter that can be accommodated, and a coating that covers the periphery of the glass of the optical fiber inserted into the glass alignment hole, a coated optical fiber alignment unit, and an optical fiber Coated optical fiber flex space, which is a space that can be bent, and a coated optical fiber flex space wedge into which a coated optical fiber flex space wedge and an optical fiber gripper wedge are inserted. It has an insertion hole and a wedge insertion hole for an optical fiber gripping portion, and a covered optical fiber is attached to the wedge insertion hole for a coated optical fiber bending space. Insert the optical fiber gripper wedge into the optical fiber gripper insert with the optical fiber gripper wedge inserted into the optical fiber gripper wedge insert hole. When the optical fiber is pressed toward the glass alignment hole from the rear end of the connector, the coating of the coated optical fiber is peeled off at the entrance of the glass alignment hole, and the peeled coating is accommodated in the coating removing portion.

  Since the optical fiber coating removal work before inserting the optical fiber into the optical connector, which is essential in the conventional optical connector assembling work, becomes unnecessary, the assembling work efficiency is improved. In addition, since the optical fiber can be inserted into the optical connector and assembled while the cover is attached, the optical fiber can be prevented from being broken and a highly reliable assembly operation can be realized.

  At the tip position of the optical fiber inside the optical connector, the optical fiber is aligned with the outer diameter of the glass, which has better dimensional accuracy than the outer diameter of the coating, so that the low connection loss equivalent to that of the conventional optical connector can be realized.

It is a cross-sectional schematic diagram of an example of the conventional optical connector. It is an external appearance schematic diagram of the optical connector concerning one Embodiment of this invention. FIG. 3 is a schematic cross-sectional view of the optical connector of FIG. 2, (a) is a cross-sectional schematic view of the A cross-section of FIG. It is a cross-sectional schematic diagram of the ferrule used for the optical connector of FIG. 2, (a) is an outer cylinder member, (b) is an inner cylinder member, (c) is a cross section when inserting an inner cylinder member into an outer cylinder member It is a schematic diagram. It is a cross-sectional schematic diagram of the flange used for the optical connector of FIG. 2, (a) is before wedge insertion, (b) is before optical fiber insertion, (c) is a schematic cross-sectional view after optical fiber insertion. FIGS. 3A and 3B are schematic cross-sectional views of an optical fiber gripping part used in the optical connector of FIG. is there. It is a cross-sectional schematic diagram of the ferrule tip when an optical fiber is inserted into the optical connector of FIG. FIG. 3 is a schematic cross-sectional view of an optical connector when an optical fiber is inserted into the optical connector of FIG. 2, (a) is a cross-sectional schematic view of the A cross-section of FIG. It is a cross-sectional schematic diagram of the optical connector at the time of connection of the optical connectors of this invention.

  Examples of the present invention will be described. The optical fiber in the present embodiment is made of glass and a coating in which the glass is covered with a resin, and has the same configuration as a general-purpose optical fiber such as a general-purpose SM optical fiber.

  FIG. 2 is a schematic external view of the optical connector according to the embodiment. FIG. 3 shows a schematic cross-sectional view of the optical connector shown in FIG. 3A shows a cross section along plane A in FIG. 2 and FIG. 3B shows a cross section along plane B. Both plane A and plane B are parallel to the axial direction of the optical connector in FIG. Is a surface that bisects.

  The optical connector includes a ferrule 1, a flange 2 that grips the ferrule at the rear end of the ferrule 1, an optical fiber gripping portion 3 that is connected to the rear end of the flange 2, and a housing 4. The optical fiber gripping portion 3 has a grip portion wedge insertion hole 9, and the flange 2 has a flange wedge insertion hole 10.

  FIG. 4 is a schematic cross-sectional view of the ferrule part of the optical connector shown in FIG. The ferrule 1 is composed of an outer cylinder member 11 and an inner cylinder member 12. FIG. 3 (a) shows the outer cylinder member 11 of the ferrule, (b) shows the inner cylinder member 12, and (c) shows the inner cylinder to the outer cylinder member 11. The cross-sectional schematic diagram when the member 12 is inserted is shown. The outer cylinder member and the inner cylinder member have a common cylindrical shaft 13, and each has a cylindrical hole having a common axis with the cylindrical shaft 11 in parallel with the cylindrical shaft 11. It is used by inserting it into a cylindrical hole of the cylindrical member. The cylindrical hole inside the outer cylinder member has three different inner diameters. The inner diameters of the glass alignment hole 14, the hole of the coating removal portion 15, and the hole into which the inner cylindrical member is inserted are different. In this embodiment, a general-purpose SM fiber is used, and since the glass of the optical fiber is inserted into the glass alignment hole, the inner diameter thereof is set to a value between 0.1255 mm and 0.1265 mm. The coated optical fiber is inserted into the cylindrical hole 16 of the inner cylinder member 12 and plays a role of keeping the shape of the coated optical fiber straight. For this purpose, the inner diameter of the coated optical fiber aligning portion 16 is set to 0.265 mm which is the same as the maximum value of the outer diameter of the coating. When the inner cylinder member 12 is inserted into the outer cylinder member 11, the inner cylinder member 12 stops at the entrance of the coating removal section 15 because the inner diameter of the tip of the outer cylinder member 11 is reduced by the coating removal section 15. By inserting the inner cylinder member into the outer cylinder member, the glass alignment hole 14 into which only the glass of the optical fiber is inserted, and the coating covering the periphery of the glass inserted into the glass alignment hole are removed and positioned. The coating removal unit 15 and the coated optical fiber alignment unit 16 that holds the coated optical fiber in a straight line state are configured. When a coated optical fiber is inserted from the coated optical fiber aligning portion 16 into the ferrule in a state where the inner cylindrical member is inserted into the outer cylindrical member, the optical fiber is inserted into the glass alignment hole 14 in the coated optical fiber. The coating that has been peeled off during the process enters the coating removing section 15.

  Ferrule 1 is press-fitted into flange 4 and connected. FIG. 5 shows a schematic sectional view of the flange 4 in the direction perpendicular to the axis of the cylindrical flange 4. The flange includes a coated optical fiber bending portion 17 which is a space for bending the coated optical fiber when the optical connectors are connected to each other, and a flange wedge insertion hole 10 into which the wedge 18 is inserted. When the optical fiber is inserted into the optical connector of this embodiment, the optical fiber is structured to pass through the coated optical fiber bending portion 17. In the present embodiment, the coated optical fiber deflecting portion 17 is a space having a rectangular parallelepiped shape in which the vertical length is a and the horizontal length is b in the direction perpendicular to the flange axis. The length a is set to 0.265 mm which is the same as the maximum value of the outer diameter of the coating, similarly to the inner diameter of the coated optical fiber alignment portion 16. It is assumed that the length b is large enough that the optical fiber bending that occurs when the optical connectors are connected to each other is accommodated in the coated optical fiber bending portion 17. The flange wedge insertion hole 10 has a structure that penetrates the coated optical fiber bending portion 17. When the flange wedge 18 is inserted into the flange wedge insertion hole 10, a part of the space of the coated optical fiber bent portion 17 is filled with the flange wedge 18 as shown in FIG. 5B, and the coated optical fiber bent portion 17. A space having a lateral length a ′ is left at a position where the inner optical fiber passes. The horizontal length a 'is set to the same size as the vertical length a. While the flange wedge 18 is inserted, the coated optical fiber bending portion 17 is in a state where the optical fiber cannot be bent.

  FIG. 6 shows a schematic cross-sectional view of the optical fiber gripping portion in the direction perpendicular to the axis of the square columnar optical fiber gripping portion 3. The optical fiber gripping portion includes a grooved substrate 19, a lid 20, and a clamper 21. The clamper 21 has a U-shaped cross section, and elastically applies pressure to the substrate 19 and the lid 20 in a state where the grooved substrate 19 and the lid 20 are overlapped to hold the shape of the optical fiber gripping portion. Yes. The clamper 21 covers three surfaces of the side surface of the rectangular columnar optical fiber gripping portion, and the gripping portion wedge insertion hole 9 is provided on the remaining surface of the optical fiber gripping portion that is not covered by the clamper 21 (FIG. 6A )). The grooved substrate 19 has a groove 22 in a direction parallel to the axis of the rectangular columnar optical fiber gripping portion 3. The groove 22 is designed so that when the optical fiber gripping portion 3 is connected to the rear end of the flange 2, the groove 22 is in a straight line with a portion through which the optical fiber passes in the coated optical fiber bending portion 17 of the flange. The cross section of the groove 22 is so small that the coated optical fiber cannot pass through the groove 22 before the optical fiber gripper wedge 23 is inserted into the gripper wedge insertion hole 9, but the glass of the optical fiber passes through it. Big enough to do. When the optical fiber gripper wedge 23 is inserted into the gripper wedge insertion hole 9, the gap between the grooved substrate 19 and the lid 20 is widened. The spread of the gap is such a size that the coated optical fiber can be inserted without bending the optical fiber inside the gap. When the gap between the grooved substrate 19 and the lid 20 is widened, the coated optical fiber is inserted through the gap from the rear end of the optical connector toward the ferrule side through the gap. Can do. When the optical fiber gripping wedge 23 is removed after the optical fiber is inserted, the coated optical fiber is elastically held at the position of the groove 22.

  In this embodiment, the flange wedge 18 inserted into the flange wedge insertion hole 10 and the optical fiber gripper wedge 23 inserted into the gripper wedge insertion hole 9 are produced as an integral part. Accordingly, the insertion of the wedges 18 and 23 into the flange wedge insertion hole 10 and the grip portion wedge insertion hole 9 is performed simultaneously.

  Next, the optical fiber insertion method of the optical connector in the present embodiment will be described.

  The wedges 18 and 23 are inserted into the flange wedge insertion hole 10 and the gripper wedge insertion hole 9. Next, the coated optical fiber, whose end face has been polished in advance and whose coating has not been removed, is inserted from the rear end of the optical connector, that is, from the gap between the grooved substrate 19 and the lid 20 of the optical fiber gripping portion 3. The tip of the optical fiber inserted into the optical connector includes a gap between the grooved substrate 19 and the lid 20 of the optical fiber gripping part 3, an optical fiber bending part 17 with a flange coating, and an optical fiber with a ferrule coating. It passes straight through the alignment section 16 and reaches the coating removal section 15 at the tip of the ferrule. Here, the optical fiber is pressed toward the glass alignment hole 14 from the rear end of the optical connector, and only the glass of the optical fiber is inserted into the glass alignment hole 14. If the optical fiber is in a state of being bent inside the coated optical fiber flexible portion 17 of the flange, the optical fiber is bent inside the coated optical fiber flexible portion 17 when the optical fiber is pressed toward the glass alignment hole. . However, as shown in FIG. 5B, the coated optical fiber bent portion 17 has a shape in which the optical fiber is not bent inside the coated optical fiber bent portion 17 by the wedge 18 inserted in advance. The optical fiber can be pressed toward the glass alignment hole 14 without bending the optical fiber. The internal state of the ferrule at this time is shown in FIG. FIG. 7 is a schematic sectional view of a ferrule. As a result, as shown in FIG. 7, by pressing the optical fiber from the rear end of the optical connector, the coating is removed between the glass alignment hole 14 and the coating removal portion 15, and only glass is inserted into the glass alignment hole. Is done. The coating removed at the entrance of the glass alignment hole is accommodated in the coating removal portion 15 having an inner diameter larger than the outer diameter of the coated optical fiber. After the projection of the optical fiber glass from the end surface of the ferrule is set to a predetermined length d, the wedge 23 inserted into the wedge insertion hole 9 for the gripping portion is removed, and the optical fiber is elastically held by the optical fiber gripping portion. At this time, the wedge 18 inserted into the flange wedge insertion hole 10 is also removed. FIG. 8 shows a schematic cross-sectional view of the optical connector when the optical fiber is inserted into the optical connector and the assembly is completed.

  FIG. 9 is a schematic cross-sectional view of the optical connector when the optical connectors are connected to each other. By holding the optical fiber protruding from the ferrule end face, the optical fiber bends inside the flange at the time of connection, and the optical fiber end faces are connected to each other by an elastic restoring force generated by the bending. As shown in FIG. 9, the optical fiber bends inside the flange during connection. Since the glass alignment hole 14 located on the ferrule axis aligns only the glass and the ferrules are also aligned in the split sleeve, it achieves the same low connection loss as conventional connectors such as SC connectors and MU connectors. To do.

  Further, by setting the outer diameter of the ferrule to 2.50 mm, which is the same outer diameter as the ferrule used in the SC connector, and making the housing the same housing as the SC connector, a connector compatible with the SC connector can be obtained. . That is, the connection with the SC connector becomes possible through the adapter of the SC connector. It is possible to make the connector compatible with the MU connector by setting the outer diameter of the ferrule to 1.25 mm, which is the same outer diameter as the ferrule used in the MU connector, and making the housing the same housing as the MU connector. . The same applies to compatibility with other conventional connectors. Therefore, it is possible to determine the type of connector to be connected at the connection work site, and to select and assemble a compatible optical connector of the present invention.

DESCRIPTION OF SYMBOLS 1 Ferrule 2 Flange 3 Optical fiber gripping part 4 Housing 5 Optical fiber 6 Small-diameter hole of ferrule 7 Space where optical fiber bends 8 Part which elastically holds optical fiber 9 Wedge insertion hole 10 Flange wedge insertion hole 11 Outside Tube member 12 Inner tube member 13 Axis 14 Glass alignment hole 15 Cover removal portion 16 Covered optical fiber alignment portion 17 Covered optical fiber bending portion 18 Flange wedge 19 Grooved substrate 20 Lid 21 Clamper 22 Groove 23 For optical fiber gripping portion Wedge

Claims (4)

An optical fiber from which the coating has been removed protrudes from the tip of the optical connector, and when the optical connectors are connected to each other, an end face of the optical fiber is generated by an elastic restoring force generated by bending of the optical fiber inside the optical connector. An optical connector that presses each other to connect a physical contact, and the optical connector includes:
A glass alignment hole, which is a cylindrical hole located at the tip of the optical connector and having an inner diameter into which only the glass portion of the optical fiber can be inserted;
A coating removing unit which is located immediately after the glass alignment hole and accommodates the optical fiber and a coating covering the periphery of the glass of the optical fiber inserted into the glass alignment hole;
A coated optical fiber aligning portion that is located immediately after the coating removing portion and is a space that accommodates the coated optical fiber, and is a space that holds the optical fiber in a straightly traveling state; and
Coated optical fiber bending, which is a space that is located immediately after the coated optical fiber alignment portion and accommodates the coated optical fiber, and has a size that allows the optical fiber to bend. Space,
An optical fiber gripping portion that is located immediately after the optical fiber bending space with the coating and is located at the rear end of the optical connector and elastically holds the optical fiber with the coating;
The coated optical fiber bending space in which the coated optical fiber bending space wedge and the optical fiber holding portion wedge are inserted into the coated optical fiber bending space and the optical fiber gripping portion, respectively. A wedge insertion hole for the optical fiber and a wedge insertion hole for the optical fiber gripping part, the glass alignment hole, the coating removal part, the coated optical fiber alignment part, the coated optical fiber bending space, The optical fiber gripping part is arranged so that the optical fiber is inserted linearly,
When the covered optical fiber bending space wedge is inserted into the coated optical fiber bending space wedge insert hole, the size of the coated optical fiber bending space becomes such that the optical fiber cannot be bent, The coated optical fiber bending space has a shape that holds the optical fiber in a straight state,
A space of a size that allows insertion of the coated optical fiber into the optical fiber gripping portion when the optical fiber gripping portion wedge is inserted into the optical fiber gripping portion wedge insertion hole, and the inserted optical fiber does not bend. When the optical fiber gripper wedge is inserted, the optical fiber is inserted into the optical fiber gripper, and the optical fiber gripper wedge is removed. Hold elastically,
The optical connector in a state in which the covered optical fiber bending space wedge is inserted into the coated optical fiber bending space wedge and the optical fiber holding portion wedge is inserted into the optical fiber holding portion wedge insertion hole. When an optical fiber that has not been coated is inserted from the optical fiber gripping portion and the optical fiber is pressed from the rear end of the optical connector toward the glass alignment hole, the coated optical fiber is coated with the glass alignment hole. The optical connector is characterized in that the coating that has been peeled off at the entrance of the cable is housed in the coating removal portion. An optical connector having a ferrule,
The ferrule is composed of an outer cylinder member having a cylindrical hole and an inner cylinder member having a cylindrical hole,
The inner cylinder member is inserted into a cylindrical hole of the outer cylinder member,
The cylindrical hole of the outer cylinder member has a structure in which holes having three different inner diameters are connected linearly,
The cylindrical hole of the inner cylinder member has an inner diameter such that when the coated optical fiber is inserted, the inserted coated optical fiber is not bent,
The cylindrical hole of the outer cylinder member located at the tip of the outer cylinder member forms the glass alignment hole by having an inner diameter through which only the glass of the optical fiber can be inserted,
The cylindrical hole of the outer cylinder member located in the middle of the outer cylinder member accommodates the coated optical fiber and the coating peeled off when the optical fiber is inserted into the glass alignment hole. Forming the coating removal portion by having an inner diameter smaller than the outer diameter of
2. The coated optical fiber alignment portion is formed by forming a cylindrical hole of the outer cylinder member located at a rear end of the outer cylinder member having an inner diameter larger than that of the inner cylinder member. Optical connector. The shape of the coated optical fiber bending space is such that the direction in which the inserted optical fiber can be bent is perpendicular to the insertion direction of the coated optical fiber bending space wedge. The optical connector according to 1.   The coated optical fiber bent space wedge and the optical fiber gripper wedge are integrated, and the coated optical fiber bent space wedge and the optical fiber gripper wedge are coated optical fiber. The optical connector according to claim 1, wherein the insertion and removal of the bending space for the wedge insertion hole and the optical fiber gripping portion wedge insertion hole are performed simultaneously.

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