JP2014178617A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connector capable of easily detecting wrong assembly of an optical fiber core wire without troublesome confirmation work such as inspecting light conduction.SOLUTION: An optical connector 11 includes: a plurality of optical fiber core wires 13 whose color for identification is set; a ferrule connected to a tip part of the optical fiber core wires 13; a housing 17 for accommodating the ferrule; a ferrule holding member 19 that is mounted in a housing to position and hold the ferrule and the optical fiber core wires 13 in the housing; a plurality of fiber insertion grooves that are recessed at a side surface of the holding member of the ferrule holding member for accommodating each of the optical fiber core wires 13; fiber core wire color check holes 23 that are drilled at a bottom wall part 59 of the fiber insertion groove for confirming a color of the fiber core wire of the optical fiber core wires 13; and a confirmation hole expression opening 29 provided in the housing 17 corresponded to the fiber core wire color check hole 23.

Description

  The present invention relates to an optical connector that accommodates a plurality of optical fiber core wires and is used for connection between optical fibers.

  Conventionally used RJ (Regular Jack) type optical connectors are optical connectors in which a ferrule is incorporated in an RJ type housing, and an optical fiber can be connected and disconnected by the same operation as an electrical connector. However, when the pressing portion of the elastic engagement piece is pressed, the connector plug is easily detached from the adapter, so the elastic engagement piece may come into contact with an external object or the like, and the connection may be easily released. There is a problem of lack of reliability as a connector. For example, a connector plug disclosed in Patent Document 1 has been proposed as a solution to such a problem.

The optical connector shown in FIG. 7 includes a pair of connector plugs 501 and an adapter 505, and optical connection is made by inserting each connector plug 501 into both ends of the adapter 505. The connector plug 501 has a ferrule 509 accommodated in a housing 511 having a rectangular cross section.
Elastic engagement pieces 517 are integrally provided on one side surface (upper side in the drawing) and the other side surface (lower side in the drawing) of the housing 511. An engagement portion 513 that protrudes outside the housing 511 is provided on one end side of the elastic engagement piece 517, and a pressing portion 515 that protrudes outside the housing 511 is provided on the other end side of the elastic engagement piece 517. Yes. When the connector plug 501 is inserted into the cavity 502 of the adapter 505, the engagement portion 513 of the elastic engagement piece 517 is locked in the hole 503 of the adapter 505, thereby moving the connector plug 501 in the anti-insertion direction. regulate.
That is, since the connector plug 501 is engaged with the adapter 505 by the pair of elastic engagement pieces 517, the connection state is not inadvertently released due to contact with an external object or the like. Reliability can be improved. Further, the protruding portion of the pressing portion 515 is made to substantially coincide with the housing surface of the adapter 505, or a receiving portion 521 for receiving the pressing portion 515 from the periphery is provided on the adapter 505, and this pressing portion is provided. By making the height of 515 substantially equal to the height of the receiving portion 521, it is possible to prevent tangling with other cables and the like, and to keep the wiring state of the optical cable always good.

  The ferrule 509 is an MT (Mechanically Transfer) type ferrule that holds two optical fiber core wires 507 (fiber ribbons). The optical fiber core wires 507 are provided with fiber core colors so that they can be distinguished from each other by color coding such as blue, yellow, green, red, purple, and white. The ferrule end surface 523 is provided with two pin insertion holes 527 for inserting the guide pins 525 in the width direction. These guide pins 525 are inserted into pin insertion holes 527 formed in the ferrule end surface 523 of the other connector plug 501 so as to protrude from the ferrule end surface 523 of the other connector plug 501, and the ferrule end surfaces come into contact with each other so that the connector A connection is made. A spring 529 that biases the ferrule 509 outward is provided in the housing.

  Thereby, each connector plug 501 can be easily connected to and disconnected from the adapter 505, and is configured so that the connection to the adapter 505 is not easily released.

JP 2000-147323 A

  By the way, in an optical connector assembly using a multi-core optical fiber cable 531 having two or more optical fiber core wires 507, it is necessary to accurately connect the optical fiber core wire 507 to the ferrule 509. May end up. When such an incorrect assembly is suspected, the fiber core color inside the housing cannot be seen from the outside of the connector plug 501, and therefore it is necessary to perform confirmation by troublesome work such as a light guide inspection after the connector plug is assembled.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide an optical connector that can easily detect erroneous assembly of an optical fiber core wire without requiring troublesome confirmation work such as light guide inspection.

The above object of the present invention is achieved by the following configuration.
(1) A plurality of optical fiber core wires in which a fiber core color for identification is set, a ferrule connected to a tip portion of the optical fiber core wire, a housing that houses the ferrule, A ferrule holding member that positions and holds the ferrule and the optical fiber core wire in a housing; a plurality of fiber insertion grooves that are recessed in a side surface of the ferrule holding member to accommodate the optical fiber core wire; and the light A fiber core color confirmation hole drilled in the wall of the fiber insertion groove to confirm the fiber core color of the fiber core, and an opening provided in the housing corresponding to the fiber core color confirmation hole; An optical connector comprising:

  According to the optical connector having the configuration (1), each of the plurality of optical fiber core wires is individually accommodated in the fiber insertion groove formed in the side surface of the ferrule holding member. When the ferrule holding member containing the optical fiber core wire is mounted on the housing, the side surface of the ferrule holding member faces the inner wall surface of the housing, and the fiber insertion groove becomes a closed space. In other words, the optical fiber core wire housed in the fiber insertion groove of the ferrule holding member is housed inside the fiber insertion groove that has become a closed space. A fiber core color confirmation hole is formed in the wall portion of each fiber insertion groove. The ferrule holding member attached to the housing has the fiber core color confirmation hole aligned with the opening of the housing, so the optical connector has a fiber core color confirmation of the fiber core color of the optical fiber core accommodated in the fiber insertion groove. It becomes visible from the outside through the hole.

(2) The optical connector configured as described in (1) above, wherein the ferrule holding member includes a communication portion capable of communicating between the plurality of fiber insertion grooves and allowing the optical fiber core wire to be inserted. Optical connector.

  According to the optical connector having the configuration (2), the optical fiber core wire accommodated in the fiber insertion groove can be crossed by the communication portion even if erroneous assembly is detected by checking the fiber core color. It becomes possible. That is, for example, when there are two fiber insertion grooves, the optical fiber core wire accommodated in one fiber insertion groove on the upstream side with the communication part as a boundary is changed to the other fiber insertion groove in the communication part. And is accommodated in the other fiber insertion groove on the downstream side. Similarly, the optical fiber core wire accommodated in the other fiber insertion groove is routed to one fiber insertion groove at the communicating portion, and is accommodated in one fiber insertion groove on the downstream side. As described above, by correcting the optical fiber core wire by replacing the right and left at the communicating portion, it is possible to easily cope with erroneous assembly.

(3) In the optical connector configured as described in (1) or (2) above, the fiber core color confirmation hole is formed in a bottom wall portion of the fiber insertion groove, and is formed on both side wall portions of the fiber insertion groove. An optical connector characterized in that a fiber drop prevention protrusion for partially reducing the gap is provided on both side walls of the fiber insertion groove corresponding to the fiber core color confirmation hole.

  According to the optical connector having the configuration (3), the optical fiber core wire inserted into the fiber insertion groove recessed in the side surface of the ferrule holding member is attached to the housing together with the ferrule holding member. At the time of insertion or mounting, there is a concern that the optical fiber core wire may fall out of the fiber insertion groove. For this reason, it is desirable to provide a fiber insertion groove with a fiber drop prevention protrusion that partially reduces the gap between the side walls, thereby restricting the easy dropping of the optical fiber core wire. However, since the fiber drop prevention protrusion protrudes from both side walls of the fiber insertion groove, it becomes an undercut in a general mold drawn from the groove opening side, making it difficult to form the ferrule holding member. On the other hand, in this configuration, since the fiber core color confirmation hole is opened in the bottom wall portion of the fiber insertion groove corresponding to the fiber drop prevention protrusion, the fiber core color confirmation hole is used to open the groove opening side. It is possible to remove the mold also from the bottom wall portion on the opposite side. Therefore, the ferrule holding member does not have a molding portion that becomes an undercut, and the fiber drop prevention protrusion can be easily molded.

  According to the optical connector according to the present invention, it is possible to easily detect an erroneous assembly of the optical fiber core wire without a troublesome confirmation work such as a light guide inspection.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings. .

It is a disassembled perspective view of the optical connector which concerns on one Embodiment of this invention. It is a top view of the housing shown in FIG. It is a top view of the ferrule holding member shown in FIG. It is the bottom view which looked at the ferrule holding member shown in FIG. 3 from the lower side. It is a top view of the assembled optical connector. (A) is a bottom view of the ferrule holding member in which the optical fiber core wire is normally accommodated, and (b) is a bottom view of the ferrule holding member in which the optical fiber core wire is replaced and accommodated. (A) is the perspective view which represented the connector plug which is the conventional optical connector with the adapter, (b) is principal part sectional drawing of the conventional connector plug connected via the adapter.

Embodiments according to the present invention will be described below with reference to the drawings.
As shown in FIG. 1, an optical connector 11 according to an embodiment of the present invention includes a plurality (two in this embodiment) of optical fiber core wires 13, a ferrule 15, a housing 17, a ferrule holding member 19, A fiber insertion groove 21 and a fiber core color confirmation hole 23 are provided as main components. The optical fiber core wire 13 is set with a fiber core color for identification. In addition, the optical fiber core wire 13 may be provided with marks that can be distinguished from each other. The optical connector 11 is connected to another optical fiber core wire 13 or an optical communication device, thereby connecting optical fibers in an automobile or the like.

  As shown in FIGS. 1 and 2, the housing 17 made of synthetic resin has a pair of coupling openings 25 on the front side with a mating optical connector (not shown). A rear opening 27 is formed behind the housing 17. On the rear side of the housing 17, a confirmation hole exposing opening 29 which is an opening cut from the rear opening 27 is provided. The confirmation hole exposing opening 29 is formed to correspond to the fiber core color confirmation hole 23 of the ferrule holding member 19 and exposes the fiber core color confirmation hole 23 to the outside of the housing 17. The housing 17 accommodates the pair of ferrules 15 held by the ferrule holding member 19 through the rear opening 27 on the back side of the coupling opening 25. In this specification, the optical connector 11 is described with the coupling opening 25 as the front, the rear opening 27 as the back, and the surface side where the confirmation hole exposing opening 29 is formed as the top.

  A holding member accommodating space 31 is formed inside the housing 17, and the holding member accommodating space 31 opens as the rear opening 27 at the rear end of the housing 17. The holding member housing space 31 accommodates the holding member main body 33 of the ferrule holding member 19. The ferrule holding member 19 in which the holding member main body portion 33 is accommodated in the holding member accommodation space 31 is attached to the housing 17 in a state where the crimping portion 35 protrudes from the rear opening 27.

The ferrule 15 is connected to the tip 45 of the optical fiber core wire 13 in the optical fiber cable 37. That is, the distal end portion 45 of the two-core optical fiber core wire 13 exposed by removing the jacket 41 and the tensile wire 43 from the optical fiber cable 37 is inserted and fixed to each ferrule 15. More specifically, a bare optical fiber from which the inner coating is further removed is inserted and fixed by an adhesive or the like from the optical fiber core wire 13, and the distal end of the optical fiber is disposed on the distal end surface of the ferrule small-diameter portion 47.
On the outer peripheral surface of the ferrule 15, an annular portion 51 is provided so as to be engaged with a support portion 49 of a ferrule holding member 19 to be described later and to restrict movement toward the tip side. The ferrule 15 is accommodated in the housing 17 so as to be movable in the axial direction by the ferrule holding member 19, and is elastically biased toward the distal end side of the housing 17 by a spring member 53 attached to the ferrule holding member 19.

  The ferrule 15 is butt-connected to the mating ferrule of the mating optical connector and the joining end surface of the ferrule narrow diameter portion 47. As a result, the optical fiber core wire 13 terminated so as to be connectable by the ferrule 15 is connected to the optical line of the counterpart optical connector.

  The ferrule 15 that is elastically biased forward by the spring member 53 whose tip engages with the rear surface of the annular portion 51 is further increased by the front surface of the annular portion 51 coming into contact with the support portion 49 of the ferrule holding member 19. Is prevented from protruding forward. Since the ferrule 15 can be slightly pushed backward in the connection direction within the elastic deformation range of the spring member 53 at the time of abutting with the counterpart optical connector, this prevents damage due to extreme stress concentration. The urging force of the spring member 53 acts as a butting force between the ferrules, so that the desired connection loss can be obtained stably.

  As shown in FIGS. 3 and 4, the ferrule holding member 19 is made of a hard resin material, and a holding member main body 33 having a pair of fiber insertion grooves 21 on which the two-core optical fiber core wires 13 are respectively placed. Have In this embodiment, the fiber insertion groove 21 is formed so that the cross-sectional shape is opened in a U-shaped groove shape.

  The pair of fiber insertion grooves 21 are recessed in the holding member side surface (side surface) 55 so that the front sides are separated from each other. The fiber core color confirmation hole 23 is formed in the bottom wall portion 59 which is the wall portion of the fiber insertion groove 21. The optical fiber core wire 13 accommodated in the fiber insertion groove 21 is visible through the fiber core color confirmation hole 23. That is, the fiber core color confirmation hole 23 is for confirming the fiber core color of the optical fiber core wire 13. The fiber insertion groove 21 includes a side wall portion 57 and a bottom wall portion 59 constituting a wall portion, and has the above-described U-shaped groove shape that sandwiches the bottom wall portion 59 between the side wall portions 57. The fiber core color confirmation hole 23 is formed in the bottom wall portion 59 of each fiber insertion groove 21. When the ferrule holding member 19 is attached to the housing 17, the bottom wall portion 59 is disposed in the confirmation hole exposing opening 29, and the fiber core color confirmation hole 23 can be seen through the confirmation hole exposing opening 29. (See FIG. 5).

  Further, a communication portion 61 is formed in the holding member main body portion 33, and the communication portion 61 is formed by removing a partition wall portion that defines the pair of fiber insertion grooves 21. The communication portion 61 communicates between a plurality of (one pair in this embodiment) fiber insertion grooves 21 so that the optical fiber core wire 13 can be inserted. That is, the communication part 61 is a space that can intersect the pair of optical fiber core wires 13.

  A caulking portion 35 projects from the rear end of the holding member main body portion 33 toward the rear. A fiber insertion groove 21 extends inside the caulking portion 35. The ferrule holding member 19 is accommodated in the housing in a state where the optical fiber core wire 13 is inserted into the fiber insertion groove 21, and the caulking portion 35 is led out from the rear opening 27 of the housing 17.

  The ferrule holding member 19 is mounted in the housing 17 to position and hold the ferrule 15 and the optical fiber core wire 13 in the housing 17. A support member 49 is provided at the holding member distal end portion 63 of the ferrule holding member 19, and the support portion 49 locks the annular portion 51 to restrict the movement of the ferrule 15 toward the distal end side. The support portion 49 includes a U-shaped support portion 65 extending along the outer peripheral surface of the ferrule 15, and an extending wall portion 67 that connects the pair of U-shaped support portions 65 to the holding member distal end portion 63. Each U-shaped support part 65 is formed in a semi-cylindrical shape so that each ferrule 15 can be placed and supported from below.

  A pair of spring fixing portions 69 are formed on the holding member side surface 55 of the holding member main body portion 33 with the fiber insertion groove 21 interposed therebetween. An engagement piece 71 of a spring member 53 described later is fitted into the spring fixing portion 69.

  The holding member rear end portion 73 of the ferrule holding member 19 is provided with a caulking portion 35 through which the optical fiber core wire 13 is led out. The caulking portion 35 caulks the tensile strength wire 43 and the jacket 41 of the optical fiber cable 37. 75 is attached to the outer peripheral surface. A plurality of annular projections 77 are formed on the outer peripheral surface of the crimping portion 35 in the axial direction for improving the crimping strength of the outer cover 41 and the like. The fiber insertion groove 21 is formed by cutting the annular projection 77. Thereby, the optical fiber core wire 13 can be inserted into the fiber insertion groove 21 in the direction perpendicular to the fiber axis. That is, it is not necessary to pass the optical fiber core wire 13 inward as in the case of a closed cylinder.

  Elastic locking pieces 81 are provided on the outer side portions 79 on both sides of the holding member main body portion 33. The elastic locking piece 81 is a free end whose front end is connected to the holding member main body 33 and whose rear end is gradually separated. That is, the legs are opened in a reverse C shape in plan view (see FIG. 3). The free end is formed as a locking claw 83. The elastic locking piece 81 can be elastically deformed in a direction in which the locking claw 83 approaches and separates from the outer portion 79. As will be described later, the locking claw 83 is locked to a locking step (not shown) provided inside the housing 17.

  As shown in FIG. 1, the spring member 53 is made of a thin plate made of a metal material or a resin material having a high spring property. The spring member 53 has two pairs of parallel elastic arm pieces 85, the optical fiber core wire 13 is disposed between them, and the ferrule 15 is pressed forward at the tip thereof. The spring member 53 is formed with a pair of engagement piece portions 71 that are bent vertically downward on the opposite side of the elastic arm piece 85, and the engagement piece portion 71 is associated with a spring fixing portion 69 formed on the holding member main body portion 33. Match. The spring member 53 is attached to the ferrule holding member 19 in a state of covering the fiber insertion groove 21 by preventing the detachment from the ferrule holding member 19 by engaging the engaging piece portion 71 with the spring fixing portion 69. .

  In this embodiment, the caulking ring 75 is formed in an elliptical cylinder shape that allows the two-core optical fiber core wire 13 to be inserted. For the caulking ring 75, a metal material that is easily plastically deformed is preferably used. The caulking ring 75 is placed on the outer side of the outer jacket 41 along the outer peripheral surface of the caulking portion 35, and the tensile strength wire 43 and the outer jacket 41 are fixed to the caulking portion 35 by being reduced in diameter by plastic deformation. (See FIG. 6).

  In the holding member accommodating space 31 of the housing 17, a concave portion (not shown) is formed by cutting the side wall inner surface 87 outward from the rear opening 27. A locking step portion is formed between the concave portion and the side wall inner surface 87, and the locking claw 83 of the elastic locking piece 81 comes into contact with and is locked to the locking step portion from the front.

  That is, the ferrule holding member 19 is inserted from the rear opening 27 of the housing 17 with the caulking portion 35 at the rear. The ferrule holding member 19 inserted into the rear opening 27 is bent in a direction in which the pair of elastic locking pieces 81 on both sides approach each other by the side wall inner surface 87. When the ferrule holding member 19 in which the elastic locking piece 81 is bent is further inserted into the holding member accommodation space 31, the locking claw 83 of the elastic locking piece 81 reaches the concave portion. The pair of locking claws 83 that have reached the concave portion are locked to the locking step portion when the elastic locking piece 81 is opened by the elastic restoring force, thereby preventing the ferrule holding member 19 from coming backward from the housing 17. To do.

  In the optical fiber cable 37, the optical fiber core wire 13 is led out from the caulking portion 35 of the ferrule holding member 19, while the tensile strength wire 43 and the jacket 41 are covered on the outer periphery of the caulking portion 35. The tensile strength wire 43 and the outer sheath 41 placed on the caulking portion 35 are fixed to the caulking portion 35 by caulking an elliptical cylindrical caulking ring 75 from the outside. Thereby, the optical fiber cable 37 and the ferrule holding member 19 are fixed integrally. When the optical fiber cable 37 is pulled rearward, the locking claw 83 is brought into contact with the locking step portion so that the removal of the ferrule holding member 19 is restricted. That is, the rear opening 27, the concave portion, the locking step portion, the elastic locking piece 81, and the locking claw 83 are inserted into the housing 17 from the rear opening 27 of the housing 17 and removed from the housing 17. A locking mechanism for blocking is configured.

  A boot locking notch 91 is formed at the rear end of the outer portion 79 of the ferrule holding member 19. The boot locking notches 91 are formed between a pair of notch forming pieces 93 projecting vertically outward from the respective outer portions 79 at the rear end of the holding member main body portion 33. Therefore, the notch portion 91 for locking the boot is opened with the end gap between the notch forming pieces as an open end. The boot locking notch 91 is closed at the open end by the side wall inner surface 87 of the housing 17 when the ferrule holding member 19 is inserted into the holding member accommodating space 31 of the housing 17. In other words, the open notch portion 91 for locking the boot has a hole shape whose open end is closed by the side wall inner surface 87. The boot locking notch 91 serves as a portion for preventing the boot 95 from coming off.

  As shown in FIG. 1, the boot 95 is made of a soft material such as synthetic rubber, and has a protection portion 97 that covers the outer periphery of the optical fiber cable 37 and the metal caulking ring 75. A caulking portion accommodation hole 99 is formed on the proximal end side of the protection portion 97, and the caulking portion accommodation hole 99 is caulking in which the tensile strength wire 43 and the jacket 41 of the optical fiber cable 37 are caulked and fixed to the caulking portion 35. The ring 75 is covered from the outer peripheral side. Around the protection part 97, a plurality of circumferential grooves 101 that impart appropriate flexibility to the protection part 97 are formed. The boot 95 includes a rectangular flange portion 103 that is connected to the protection portion 97 and covers the rear opening 27 of the housing 17.

  On both sides of the flange portion 103, T-shaped protrusions 105 project from the front (inner side of the housing). The boot locking notch 91 described above and the T-shaped protrusion 105 are provided as a pair on the left and right sides with the caulking portion 35 interposed therebetween. The T-shaped protrusion 105 has a bulging portion at the tip of the neck portion 107 protruding vertically from the flange portion 103. In the present embodiment, the bulging portion is formed in a columnar shape in a direction orthogonal to the neck portion 107. In addition, the bulging portion may be formed in a triangular plate shape whose bottom side is connected to the neck portion 107, a semicircular plate shape whose diameter side is connected to the neck portion 107, or the like.

  The T-shaped protrusion 105 is molded integrally with the flange portion 103 and has flexibility. With this flexibility, the T-shaped protrusion 105 can be freely opened so that the bulging portion is displaced outward. Therefore, the T-shaped protrusion 105 can be inserted into the neck 107 from the opening end of the boot locking notch 91. The T-shaped protrusion 105 in which the neck 107 is inserted into the boot locking notch 91 is prevented from coming back backward when the bulging portion hits the notch forming piece 93. When the ferrule holding member 19 is not attached to the housing 17, the T-shaped protrusion 105 allows the neck 107 to be detached from the open end. On the other hand, when the ferrule holding member 19 is attached to the housing 17, the opening end is closed by the side wall inner surface 87, so that the neck 107 cannot be removed from the opening end. As a result, the T-shaped protrusion 105 is surely prevented from coming out of the boot locking notch 91, and the housing 17, the ferrule holding member 19, and the boot 95 are integrally fixed and assembled.

  On both side wall portions 57 of the fiber insertion groove 21, fiber drop prevention protrusions 109 are projected. The fiber drop prevention protrusion 109 partially reduces the gap between the side wall portions 57 of the fiber insertion groove 21. That is, the width of the fiber insertion groove 21 is partially made smaller than the diameter of the optical fiber core wire 13. The fiber disconnection prevention protrusions 109 protrude from both side wall portions 57 of the fiber insertion groove 21 corresponding to the fiber core color confirmation hole 23.

Next, a method for assembling the optical connector 11 having the above configuration will be described.
To assemble the optical connector 11, first, a boot 95 and a caulking ring 75 are sequentially passed through the cable tip 39 of the optical fiber cable 37. And the ferrule 15 is fixed to the front-end | tip part 45 of the optical fiber core wire 13 which removed the jacket 41 and the tensile strength line 43 of the cable front-end | tip part 39, and was exposed.
Next, the ferrule 15 is placed on the support portion 49 of the ferrule holding member 19 while the optical fiber core wire 13 is inserted into the fiber insertion groove 21 that is recessed in the ferrule holding member 19. At this time, in the support portion 49, the pair of U-shaped support portions 65 holds the respective ferrules 15 along the outer peripheral surface, and locks the annular portion 51 to restrict the movement of the ferrule 15 toward the front end side. Therefore, the fixing operation for holding the ferrule 15 on the support portion 49 is facilitated.

Next, the ferrule 15 is urged forward in the axial direction by covering the fiber insertion groove 21 and engaging the front end of the spring member 53 attached to the ferrule holding member 19 with the rear surface of the annular portion 51. Then, the caulking portion 35 of the holding member rear end portion 73 from which the optical fiber core wire 13 is led is covered with the tensile strength wire 43 and the outer sheath 41 of the cable front end portion 39, and then the outer periphery thereof is caulked by the caulking ring 75. Tighten and fix (see FIG. 6).
Next, the ferrule holding member 19 holding the ferrule 15 is inserted from the rear opening 27 of the housing 17 and assembled to the housing 17 together with the boot 95.

  The boot 95 is inserted while the neck 107 of the T-shaped protrusion 105 is bent from the outside (in a direction perpendicular to the axis of the neck 107) into the boot locking notch 91 of the ferrule holding member 19. As a result, the bulging portion of the T-shaped protrusion 105 hits the pair of notch forming pieces 93 sandwiching the boot locking notch portion 91, and the optical fiber cable 37 is prevented from coming off in the lead-out direction. At this time, the neck portion 107 of the T-shaped protrusion 105 can be easily inserted into the boot locking notch portion 91 of the ferrule holding member 19 which is not accommodated in the housing by elastically deforming the neck portion 107 from the opening end. That is, the temporary assembly of the boot 95 and the ferrule holding member 19 can be easily performed.

  On the other hand, in the present assembly in which the housing 17, the ferrule holding member 19, and the boot 95 are integrated, the ferrule holding member 19 in which the T-shaped protrusion 105 is locked to the boot locking notch 91 is the rear opening 27 of the housing 17. Is inserted from. When the boot locking notch 91 into which the neck 107 of the T-shaped protrusion 105 is inserted is accommodated in the housing 17, the opening end is closed by the side wall inner surface 87 of the housing 17. As a result, the T-shaped protrusion 105 is reliably prevented from coming off from the boot locking notch 91.

  In this embodiment, the boot 95 and the caulking ring 75 are passed through the optical fiber cable 37 in this order from the cable tip 39 side where the jacket 41 and the tensile strength wire 43 are peeled and exposed, and then the ferrule is connected to the optical fiber core wire 13. 15 is connected. After the tensile strength wire 43 and the outer sheath 41 are fixed to the caulking portion 35 by the caulking ring 75, the caulking ring 75 is covered by the protective portion 97 of the boot 95. In the boot 95 covering the crimping ring 75, a T-shaped protrusion 105 protruding forward from the flange portion 103 on the inner side of the housing is locked to the ferrule holding member 19. Finally, the ferrule holding member 19 that locks the boot 95 is mounted from the rear opening 27 of the housing 17. That is, the temporary assembly for assembling the boot 95 to the ferrule holding member 19 and the main assembly for assembling the ferrule holding member 19 and the housing 17 are all in the same assembling direction along the axis of the optical fiber cable 37, thereby facilitating assembly. That is, it becomes easy to cope with assembly automation.

  In the assembly method described above, there are only two members, the boot 95 and the caulking ring 75, that pass through the optical fiber core wire 13 in advance. The optical fiber core wire 13 in which the ferrule 15 is fixed to the distal end portion 45 of the optical fiber core wire 13 is inserted into the fiber insertion groove 21 of the ferrule holding member 19 from the direction orthogonal to the fiber axis. By attaching the spring member 53 to the ferrule holding member 19, the fiber insertion groove 21 is closed, and the optical fiber core wire 13 and the ferrule 15 held in the closed fiber insertion groove 21 do not fall off. The ferrule 15 is further securely held by the annular portion 51 being sandwiched between the support portion 49 and the spring member 53 while being urged in the direction along the axis. Thereby, the ferrule 15 fixed to each optical fiber core wire 13 is held by the support portion 49 while being urged by the spring member 53, and the optical fiber cable 37 is incorporated in the ferrule holding member 19. That is, it becomes easy to simultaneously insert the pair of ferrules 15 biased by the spring member 53 into the housing 17.

Next, the operation of the optical connector 11 having the above configuration will be described.
According to the optical connector 11 of the present embodiment described above, each of the pair of optical fiber core wires 13 is a fiber insertion groove that is recessed in the holding member side surface 55 of the ferrule holding member 19 as shown in FIG. 21 individually accommodated. Then, as shown in FIG. 5, when the ferrule holding member 19 containing the optical fiber core wire 13 is attached to the housing 17, the holding member side surface 55 of the ferrule holding member 19 faces the inner wall surface of the housing, and the fiber insertion groove 21 becomes a closed space. That is, the optical fiber core wire 13 accommodated in the fiber insertion groove 21 of the ferrule holding member 19 is accommodated inside the fiber insertion groove 21 that has become a closed space.

  A fiber core color confirmation hole 23 is formed in the bottom wall portion 59 of each fiber insertion groove 21. As shown in FIG. 5, the ferrule holding member 19 attached to the housing 17 has the fiber core color confirmation hole 23 aligned with the opening of the housing 17, so that the optical connector 11 is accommodated in the fiber insertion groove 21. The fiber core color of the optical fiber core 13 can be visually recognized from the outside through the fiber core color confirmation hole 23.

Further, according to the optical connector 11 of the present embodiment, the optical fiber core wire 13 accommodated in the fiber insertion groove 21 is crossed by the communication portion 61 even when erroneous assembly is detected by checking the fiber core color. It becomes possible to make it.
That is, in the case of the ferrule holding member 19 of this embodiment having two fiber insertion grooves 21, as shown in FIG. 6B, the ferrule holding member 19 is accommodated in one fiber insertion groove 21 on the upstream side with the communication portion 61 as a boundary. The route of the optical fiber core wire 13 is changed to the other fiber insertion groove 21 at the communication portion 61, and is accommodated in the other fiber insertion groove 21 on the downstream side. Similarly, the optical fiber core wire 13 accommodated in the other fiber insertion groove 21 is routed to the one fiber insertion groove 21 at the communication portion 61, and is accommodated in the one fiber insertion groove 21 on the downstream side. . Thus, the tensile strength wire 43 and the jacket 41 of the optical fiber cable 37 are caulked and fixed to the caulking portion 35 by the caulking ring 75 by changing the left and right sides of the optical fiber core wire 13 at the communication portion 61 and correcting. Even later, it is possible to easily cope with erroneous assembly of the optical fiber core wire 13.

  Further, in the optical connector 11 of the present embodiment, the optical fiber core wire 13 inserted into the pair of fiber insertion grooves 21 provided in the holding member side surface 55 of the ferrule holding member 19 is mounted on the housing 17 together with the ferrule holding member 19. Is done. At the time of this insertion or attachment, there is a concern that the optical fiber core wire 13 may fall out of the fiber insertion groove 21. For this reason, the fiber insertion groove 21 is provided with a fiber drop prevention projection 109 that partially reduces the gap between the side wall portions 57, and the easy dropping of the optical fiber core wire 13 is restricted.

  Since the fiber drop prevention protrusion 109 protrudes from the both side wall portions 57 of the fiber insertion groove 21, it becomes an undercut in a general mold drawn from the groove opening side, and it becomes difficult to form the ferrule holding member 19. On the other hand, in the ferrule holding member 19 of the present embodiment, the fiber core color confirmation hole 23 is opened in the bottom wall portion 59 of the fiber insertion groove 21 corresponding to the fiber disconnection prevention protrusion 109. Using the color confirmation hole 23, it is possible to remove the mold from the bottom wall portion 59 on the side opposite to the groove opening side. Therefore, the ferrule holding member 19 according to the present embodiment does not have a molding portion that becomes an undercut, and the fiber drop prevention protrusion 109 can be easily molded.

Therefore, according to the optical connector 11 according to the present embodiment, it is possible to easily detect an erroneous assembly of the optical fiber core wire 13 without a troublesome confirmation work such as a light guide inspection.
The optical connector of the present invention is not limited to the above-described embodiment, and can be appropriately modified and improved. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

DESCRIPTION OF SYMBOLS 11 ... Optical connector 13 ... Optical fiber core wire 15 ... Ferrule 17 ... Housing 19 ... Ferrule holding member 21 ... Fiber insertion groove 23 ... Fiber core color confirmation hole 29 ... Confirmation hole surface opening (opening)
45 ... tip part 55 ... holding member side surface (side surface)
57 ... Both side wall parts 59 ... Bottom wall part (wall part)
61 ... Communication portion 109 ... Protrusion prevention protrusion

Claims (3)

A plurality of optical fiber cores in which a fiber core color for identification is set;
A ferrule connected to the tip of the optical fiber core;
A housing that houses the ferrule;
A ferrule holding member mounted in the housing and positioning and holding the ferrule and the optical fiber core wire in the housing;
A plurality of fiber insertion grooves recessed in the side surface of the ferrule holding member to accommodate each of the optical fiber core wires;
A fiber core color confirmation hole formed in a wall portion of the fiber insertion groove to confirm a fiber core color of the optical fiber core;
An opening provided in the housing corresponding to the fiber core color confirmation hole;
An optical connector comprising: The optical connector according to claim 1,
The optical connector, wherein the ferrule holding member includes a communication portion that allows communication between the plurality of fiber insertion grooves and allows insertion of the optical fiber core wire. The optical connector according to claim 1 or 2, wherein
The fiber core color confirmation hole is drilled in a bottom wall portion of the fiber insertion groove,
A light drop prevention projection for partially reducing a gap between both side walls of the fiber insertion groove is provided on both side walls of the fiber insertion groove corresponding to the fiber core color confirmation hole. connector.

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