JP2011034001A - Optical connector and optical connector-connecting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology which hardly causes damage to a front end of an optical fiber inserted in a ferrule, and restrains an optical loss due to a warp occurring to the optical fiber when a connector is connected. <P>SOLUTION: An optical connector 10 includes an engagement part 60, which holds a terminal part of an optical fiber cable 90, at a back end part of a sleeve-shaped housing 40 which accommodates the ferrule 20. In this case, the following inequality is satisfied: L2<L3<L1, wherein L1 represents a distance between a terminal part of the cable 90 and a front end surface 21b of the ferrule when press displacement is not given to the ferrule 20, L2 represents an distance between the terminal part of the cable 90 and the front end surface 21b of the ferrule 20 which is located at a limit-of-pressing position, and L3 represents an extended length of the optical fiber 91 which extends from the terminal part of the cable 90 and is inserted in the ferrule 20 with its possible movement in a fore-and-aft direction to the ferrule. An optical connector-connecting structure is formed by connecting the optical connector 10 with an another connector 80. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical connector, and in particular, has a cable retaining portion for retaining an optical fiber cable, and an optical fiber extending from the end of the optical fiber cable held by the cable retaining portion is formed in a ferrule. The present invention relates to an optical connector and an optical connector coupling structure that are inserted into a fiber hole so as to be movable in the extending direction of the fiber hole.

  For example, for drawing down optical lines from an aerial optical wiring network and indoor wiring, optical fibers such as optical fiber strands and optical fiber core wires are used as resin coating materials (hereinafter also referred to as jackets) together with tensile strength materials such as tensile strength fibers. Optical fiber cables that are embedded and integrated are often used. In recent years, as an optical connector for enabling such connector connection of an optical fiber cable, an outer gripping member that is fitted and fixed to an optical fiber cable end by a groove (cable fitting groove) for fitting the optical fiber cable is held. A so-called outer-grip-type field assembly optical connector (e.g., Patent Document 1) that can be easily assembled to the optical fiber cable terminal at the site has been put into practical use. It is spreading rapidly.

  As the above-described outer-grip-type field assembly optical connector, a short optical fiber (hereinafter also referred to as an internal optical fiber) inserted and fixed in advance to a ferrule and an optical fiber extending from the optical fiber cable end are connected to each other. With a clamp part with a structure in which a clamp part with a mechanical splice structure that holds the connection part in between and maintains the connection state is provided on the rear side of the ferrule (the opposite side to the front end face (joint end face) for ferrule abutment) A spring that elastically biases the ferrule and the ferrule with the clamp portion to give a butt force at the time of connector connection is accommodated in the housing, and the front end side of the housing opposite to the front end side where the ferrule is disposed is A structure having a cable retaining portion (hereinafter also referred to as a first prior art) is widely used.

Further, as an outer gripping type on-site assembly optical connector (hereinafter also simply referred to as an optical connector), in view of the demand for simplification of structure and cost reduction, for example, as shown in FIG. A configuration using a ferrule that is not provided (hereinafter also referred to as second prior art) has been proposed.
An optical connector 100 shown in FIG. 15A houses a ferrule 110 and a spring 150 (coil spring) for elastically urging the ferrule 110 toward the front side of the connector (left side in FIGS. 15A and 15B). On the rear end side of the housing 120 (on the right side in FIGS. 15A and 15B, on the side opposite to the front end side on which the ferrule 110 is disposed), an optical fiber cable 210 (optical fiber strand, optical fiber core wire). The cable holding portion 140 for storing and holding the jacket gripping member 220 fixed to the terminal of the optical fiber 211 having a structure in which the optical fiber 211 is integrated with a tensile body such as a tensile strength fiber in a resin coating material (jacket). And the optical fiber cable fastened to the cable fastening portion 140 by storing and holding the jacket gripping member 220. It has a bare optical fiber 212 to expose the tip of the optical fiber 211 extending from table 210 terminal interpolated schematic configuration in fiber hole 111 is a fine hole penetrating the ferrule 110. The optical fiber 211 extends from the inner space of the extended sleeve portion 131 which is a portion extending rearward from the ferrule 110 of the sleeve-like flange member 130 fixed to the rear end portion of the capillary ferrule 110. 111 is inserted.
However, the bare optical fiber 212 at the tip of the optical fiber 211 is inserted into the fiber hole 111 of the ferrule 110 so as to be movable in the extending direction. Further, the end of the bare optical fiber 212 slightly protrudes from the end face for abutment (joint end face 112) of the end of the ferrule 110.

  The housing 120 includes a sleeve-like plug frame 121 and a rear unit 123 having a sleeve-like stop ring portion 122 fitted and fixed to a rear end portion of the plug frame 121, and the rear unit 123. The end portion of the optical fiber cable 210 and the jacket are formed by a plate-like base portion 124 extending rearward from the rear end of the stop ring portion 122 and a retaining cover 125 pivotally attached to the rear end portion of the stop ring portion 122. The cable holding portion 140 configured to store and hold the gripping member 220 is provided at the rear end portion.

The jacket holding member 220 is fitted and fixed to the end of the optical fiber cable 210 by a cable fitting groove (not shown) provided in the jacket holding member 220.
The jacket gripping member 220 housed in the cable holding portion 140 is moved to the rear side of the connector by the stopper protrusions 124a and 125a protruding from the rear end of the base portion 124 and the rear end of the holding cover 125. Regulated and retained. As a result, the optical fiber cable 210 is fastened to the housing 120 of the optical connector 100 via the jacket gripping member 220.
The stopper protrusion 125a of the retaining cover 125 has a plate shape with a notch 125b for allowing the optical fiber cable 210 to pass therethrough, and the optical fiber cable 210 is connected to the stopper protrusion via the notch 125b. It is provided through 125a.

JP 2005-265975 A

  As shown in FIGS. 15 (a) and 15 (b), the optical connector 100 of the second prior art is when the connector is fitted (when connected to another optical connector. When the optical connector 100 is fitted to the optical connector receptacle or socket. Or when the optical connector 100 and the optical connector 100 on the other end of the connection are fitted to each other and connected to each other), first, the optical fiber 211 protruding from the joining end surface 112 of the ferrule 110 of the optical connector 100 The optical fiber 311 (the tip of this optical fiber 311) is inserted into and fixed to the ferrule 310 of the optical connector on the other end of the connection (hereinafter also simply referred to as the counterpart optical connector). Are aligned with the front end surface of the ferrule 310), and the optical fiber 2 as the ferrule 110 and 310 approach each other. 1 of the protrusion 213 is pushed into the rear side of the ferrule 110. The pushing of the protruding portion 213 of the optical fiber 211 into the ferrule 110 is completed when the ferrules 110 and 310 are brought into contact with each other, and then the spring 150 of the optical connector 100 is moved by continuing the pushing of the connector for connector fitting. The ferrule 110 is pushed to the rear side of the connector (pushbacked) as it is compressed and deformed. As a result, the optical fiber 211 bends between the end of the optical fiber cable 210 and the ferrule 110, and the tip of the optical fiber 211 abuts against the optical fiber 311 of the ferrule 310 of the counterpart optical connector due to the elasticity of the bend. Butt connected with force. The optical connector 100 according to the second prior art can realize connector connection between optical fibers with a simpler configuration than the optical connector according to the first prior art.

  By the way, in the optical connector of the second prior art, in terms of suppressing the optical loss at the time of connection with other optical connectors, the optical fiber is connected between the optical fiber cable terminal held by the cable holding portion and the ferrule. In order to suppress the optical loss due to the bending formed in the optical fiber of the cable, it is desirable to minimize the size of the bending. In addition, as a result of verification by the present inventor, in the case of the optical connector 100 of the second conventional technology, an abutting force (necessary minimum) between the optical fibers is increased more than necessary due to the bending formed in the optical fibers when the connectors are fitted. It has been found that an abutment force with a strength that greatly exceeds) acts.

  However, the optical connector 100 of the second prior art is optically driven by pushback of the ferrule 110 and pushing of the protruding portion 213 protruding from the joining end surface 112 of the ferrule 110 of the optical fiber 211 into the ferrule 110 when the connector is fitted. Since the fiber 211 is configured to bend, the size of the bend formed in the optical fiber 211 is relatively large. For example, in comparison with an optical connector in which the tip of an optical fiber inserted and fixed in a ferrule is aligned with the ferrule tip surface and the optical fiber is bent only by the pushback amount of the ferrule when the connector is fitted, The amount of bending is increased by the amount of pushing of the protruding portion 213 of the fiber 211. For this reason, the optical connector 100 according to the second prior art is disadvantageous for downsizing the bending formed in the optical fiber 211 between the end of the optical fiber cable 210 and the ferrule 110, and reducing the loss due to the bending. There was a problem that it was not easy.

  Further, in the optical connector 100 of the second prior art, when the connector is fitted, the protruding portion 213 of the optical fiber 211 is missing due to the contact of the optical fiber 311 (or the ferrule 310) of the ferrule 310 of the connection partner side optical connector ( In particular, there is a defect that the optical fiber 211 is easily damaged (easy to be damaged) such as a chip on the outer periphery of the front end surface) and a scratch on the front end surface.

  In view of the above problems, the present invention makes it difficult to damage the tip of an optical fiber inserted into a ferrule when a connector is fitted, and can easily realize downsizing of the bend formed in the optical fiber. An object of the present invention is to provide an optical connector and an optical connector coupling structure that can suppress loss.

In order to solve the above problems, the present invention provides the following configuration.
According to a first aspect of the present invention, an optical fiber cable is provided at a rear end portion of a sleeve-like housing that houses a ferrule and a spring for elastically biasing the ferrule, opposite to a front end portion where the front end portion of the ferrule is disposed. A holding part for holding the terminal part or the optical fiber by restricting the displacement in the central axis direction of the housing; the holding part has a holding part for holding the optical fiber cable terminal part or the optical fiber; In the fiber hole formed in the ferrule, the distal end portion of the distal end side extending portion extending from the portion gripped by the grip portion of the optical fiber or the distal end portion of the optical fiber extending from the optical fiber cable end portion is formed. The optical fiber or the optical fiber cable that is inserted so as to be movable in the extending direction of the fiber hole and is gripped by the gripping portion. A distance L1 from the gripped portion, which is a portion gripped by the holding portion, to the tip end surface of the ferrule when no pushing displacement to the rear side of the housing is given, and a push limit of the ferrule to the rear side of the housing An optical connector characterized in that a distance L2 from the gripped portion to the ferrule tip surface when in position and an extension length L3 of an optical fiber extending from the gripped portion satisfy L2 <L3 <L1 I will provide a.
According to a second aspect of the present invention, the optical fiber cable has a structure in which an optical fiber is embedded in a resin coating material together with a linear strength member vertically attached to the optical fiber, and the grip portion is the optical fiber cable terminal. A sheath holding member that is fixed by gripping the optical fiber cable terminal portion to a portion, and the retaining portion is displaced in the direction of the central axis of the housing by the fastening portion being fixed to the optical fiber cable terminal portion The optical connector according to the first aspect of the present invention is a cable holding portion that holds the optical fiber cable terminal portion to the housing by restricting and holding the optical fiber cable.
According to a third aspect of the present invention, the optical fiber gripped by the gripping portion is an optical fiber core or an optical fiber strand, and the bare optical fiber exposed at the tip of the optical fiber is inserted into the fiber hole of the ferrule. The optical connector according to the first aspect of the present invention is provided.
According to a fourth aspect of the present invention, there is provided a distance L1 from the gripped portion to the ferrule tip surface when the ferrule is not displaced toward the rear end of the housing, and the ferrule is at the push limit position. The optical connector according to any one of the first to third aspects, wherein a difference from a distance L2 from the gripped portion to the ferrule tip surface at a certain time is less than 1 mm.
According to a fifth aspect of the present invention, a rear side that restricts movement of the ferrule to the rear side of the housing by contacting a flange portion of the ferrule that is pushed toward the rear end side of the housing inside the housing. A stopper protrusion is provided, and the position where the flange protruding from the ferrule contacts the rear stopper protrusion is the push-in limit position of the ferrule. An optical connector according to any one of the inventions 1 to 4 is provided.
According to a sixth aspect of the present invention, the housing has a front stopper protrusion for restricting the ferrule from coming out of the front side of the housing by abutting the flange portion of the ferrule on the inner side of the housing. When the distance L1 from the gripped portion to the ferrule tip surface when no pushing displacement toward the rear end side is given, the flange portion of the ferrule is in contact with the front stopper projection of the housing The optical connector according to any one of the first to fifth aspects is characterized in that the distance is from the gripped part to the ferrule tip surface.
A seventh invention is an optical connector coupling structure of a socket-plug coupling system or a plug-adapter-plug coupling system, wherein the first optical connector which is the optical connector of any one of the first to fifth inventions, a ferrule, A second optical connector which is an optical connector having a configuration in which a spring for elastically energizing the ferrule is housed in a housing and the tip of an optical fiber inserted and fixed to the ferrule is positioned on the tip surface of the ferrule; The first optical connector and the second optical connector are fitted or inserted into the optical connector adapter, and the ferrules are brought into contact with each other by fitting, and the optical fiber inserted into the ferrule of the first optical connector and the first optical fiber An optical fiber inserted and fixed to the ferrule of the two optical connector is abutted against each other, and the covered portion of the first optical connector is To provide an optical connector coupling structure, characterized in that is formed deflected extending optical fiber between the sandwiching member and the ferrule body of the ferrule.
An eighth invention provides the optical connector coupling structure according to the seventh invention, wherein the ferrule of the first optical connector is arranged at a pushing limit position.
According to a ninth aspect of the present invention, the ferrule is pushed into the rear end side opposite to the front end where the ferrule of the housing is disposed as the second optical connector in a state of being detached from the optical connector adapter. A movable amount is a distance L1 from the gripped portion to the ferrule tip surface when the ferrule of the first optical connector is not displaced toward the rear end of the housing. The optical connector coupling structure according to the seventh or eighth invention is characterized in that a larger one than the difference from the distance L2 from the gripped portion to the ferrule tip surface when in the pushing limit position is used. .

The optical connector according to the present invention is inserted into the ferrule as compared with the pushback amount of the ferrule when connected to another optical connector (an optical connector having a ferrule with an optical fiber inserted and fixed). The amount of movement of the front end of the optical fiber toward the connector rear side (pushback amount at the front end of the optical fiber) can be kept small. For this reason, the bending size formed in the optical fiber at the time of connector fitting (when connected to another optical connector) can be reduced as compared with the case of the optical connector of the second prior art. Light loss due to bending can be suppressed.
In addition, since the tip of the optical fiber inserted into the ferrule is arranged at a position shifted to the rear side of the ferrule (the rear side of the optical connector) from the ferrule tip surface, the tip of the optical fiber is damaged when the connector is fitted. The effect that it is difficult is acquired.

  According to the optical connector coupling structure according to the present invention, since the optical connector according to the present invention is used, optical loss due to bending of the optical fiber in the first optical connector that is the optical connector according to the present invention is suppressed. Therefore, it is possible to easily reduce the connection loss due to the connector connection between the optical fibers.

It is sectional drawing which shows the optical connector (1st optical connector) of 1st Embodiment which concerns on this invention, and an optical connector coupling structure, Comprising: (a) is before connector fitting, (b) is fitting operation | work of optical connectors. The state where the ferrule of the optical connector according to the present invention has reached the push-in limit position (before completion of connector fitting) and (c) shows the state where connector fitting (fitting of optical connectors) is completed. It is an expanded sectional view (state before connector fitting) which shows the optical connector (1st optical connector) which concerns on this invention. It is a disassembled perspective view explaining the structure of the securing part (cable retaining part) of the optical connector (1st optical connector) of 1st Embodiment. FIG. 4 is a perspective view for explaining a gripping portion (outer gripping member) of the pulling portion (cable holding portion) in FIG. 3. It is a perspective view which shows the terminal part of the optical fiber cable with which the optical connector (1st optical connector) of 1st Embodiment is assembled. FIG. 5 is a partial perspective plan view for explaining a holding and fixing state of the optical fiber cable terminal portion in the holding portion (outer holding member) of FIG. 4. It is a side view which shows the external appearance structure of the optical connector (1st optical connector) of 1st Embodiment. It is a figure explaining the optical connector joint structure of the socket-plug system of 1st Embodiment, (a) is before connector fitting (a state where the socket and the optical connector are separated from each other), and (b) is connector fitting. The combined state (the state in which the optical connector coupling unit is assembled) is shown. It is a figure explaining the optical connector (1st optical connector) of 2nd Embodiment which concerns on this invention, and an optical connector coupling structure, Comprising: (a) is before connector fitting (1st, 2nd optical connector is an optical connector, respectively. The state separated from the adapter), (b) shows the connector fitting state (the state in which the optical connector coupling unit is assembled). It is sectional drawing explaining the optical connector (1st optical connector) of 3rd Embodiment which concerns on this invention. It is a perspective view which shows the holding part (mechanical splice) of the securing part (optical fiber retaining part) of the optical connector of FIG. 12A and 12B are cross-sectional views illustrating the structure of the gripping portion (mechanical splice) in FIG. 11, where FIG. 11A shows a state in which the optical fiber core wire is gripped and fixed, and FIG. 11B shows a state in which a pair of elements is open. It is sectional drawing explaining an example of the optical connector of the structure assembled to the optical fiber cord terminal part as 4th Embodiment of the optical connector which concerns on this invention. It is sectional drawing explaining 5th Embodiment of the optical connector which concerns on this invention. It is sectional drawing explaining the optical connector of a 2nd prior art, (a) is before connector fitting, (b) shows a connector fitting state.

  Hereinafter, an optical connector and an optical connector coupling structure embodying the present invention will be described with reference to the drawings.

(First embodiment)
First, an optical connector and an optical connector coupling structure according to the first embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 1A to 1C, the optical connector 10 is assembled to a terminal portion of an optical fiber cable 90.
As shown in FIG. 5, the optical fiber cable 90 includes an optical fiber 91 (specifically, an optical fiber wire here) and a resin covering material 93 (hereinafter also referred to as a jacket) together with a tensile body 92 such as a tensile fiber. It has a configuration that is embedded and integrated.

The optical fiber cable 90 is used as a drop cable or a so-called indoor cable for indoor wiring. In the illustrated example, a single-core cable having only one optical fiber 91, which is an optical fiber strand, is illustrated. ing.
The optical fiber cable 90 is a coated optical fiber such as a single-core optical fiber instead of the optical fiber as the optical fiber 91 (a resin coating material is coated on the bare optical fiber). A configuration using an optical fiber having a configuration can also be employed.

  As shown in FIGS. 1A to 1C and FIG. 2, the optical connector 10 elastically biases the ferrule 20 and the ferrule 20 toward the front side of the connector (left side in FIGS. 1A to 1C). The rear end side of the sleeve-like housing 40 that houses the spring 30 (coil spring) for the right side (the right side in FIGS. 1A to 1C). The front end surface of the ferrule 20 (the front end surface 21b of the capillary ferrule main body 21) The outer gripping member 50 fixed to the end portion of the optical fiber cable 90 on the opposite side of the front end side where the optical fiber cable 90 is disposed is a central axis of the housing 40 (a central axis of a housing body 40A described later). It has a cable retaining portion 60 (retaining portion) that holds and holds (fixed here) by restricting the displacement in the direction. The optical connector 10 includes an optical fiber 91 (an optical fiber cable 90 end of the optical fiber 91) that extends from the end portion of the optical fiber cable 90 held in the cable holding portion 60 by storing and holding the jacket holding member 50. A fiber hole which is a fine hole penetrating through the ferrule body 21 (described later) of the ferrule 20 through the exposed portion of the bare optical fiber 91a which is exposed by removing the coating of the tip of the portion extending from the tip. It has a schematic configuration in which 21a is inserted so as to be movable in the central axis direction (extending direction) of the fiber hole 21a.

Specifically, the ferrule 20 is located on the opposite side of the end face (joint end face; hereinafter referred to as the front end face 21b) of the end of the ferrule body 21 (ferrule tip), which is a capillary member made of zirconia ceramics, for example. A sleeve-like flange member 22 is externally fixed at the end.
In the ferrule 20, the front end surface 21 b of the ferrule body 21 functions as the front end surface of the ferrule 20. Hereinafter, the front end surface 21b of the ferrule body 21 is also referred to as a ferrule front end surface. The ferrule tip end surface 21b is subjected to polishing such as PC polishing (PC).

  The ferrule main body 21 is, for example, an SC type optical connector (F04 type optical connector established in JIS C 5973. SC: Single fiber Coupling optical fiber connector) or an MU type optical connector (F14 type optical connector established in JIS C 5983). A well-known one used for a ferrule of a single-fiber optical connector such as MU (Miniature-Unit coupling optical fiber connector) can be adopted. The material of the ferrule body 21 can be a known material used for a ferrule of a single-fiber optical connector, and is not limited to zirconia ceramics, and may be glass or the like, for example.

  As shown in FIG. 2, the flange member 22 is externally fixed by fitting one end of the sleeve-like main body (sleeve-like main body 22a) in the central axis direction into the rear end portion of the ferrule main body 21, etc. 21 has an extending sleeve portion 22b extending from the rear end portion to the rear side (the side opposite to the front end surface 21b). Further, the flange member 22 has a flange portion 22c protruding from the outer periphery of a portion (front end portion) that is externally fixed to the rear end portion of the ferrule main body 21 of the sleeve-like main body 22a. The flange portion 22 c functions as a flange portion of the ferrule 20.

As shown in FIG. 2, the inner space 22d of the extending sleeve portion 22b of the flange member 22 has a larger hole shape than the fiber hole 21a.
The fiber hole 21a of the ferrule main body 21 is formed so that the rear end thereof opens at the center of the rear end surface 21c of the ferrule main body 21 facing the inner space 22d of the extending sleeve portion 22b of the flange member 22. The fiber hole 21a and the inner space 22d of the extending sleeve portion 22b of the flange member 22 are provided so that their center axes substantially coincide with each other. Hereinafter, the inner space 22d of the flange member 22 is also referred to as a ferrule rear hole or simply a rear hole. The ferrule 20 has a through hole (hereinafter also referred to as a fiber accommodation through hole 23) in which the fiber hole 21a and the ferrule rear hole 22d communicate with each other.

  As shown in FIG. 2, the optical fiber 91 of the optical fiber cable 90 is connected to a stop ring portion 42 (described later) of the housing 40 from an end portion of the optical fiber cable 90 fixed to the cable holding portion 60 at the rear end of the housing 40. It extends into the housing 40 through the opening 42 a at the rear end, and is inserted into the fiber housing through hole 23 from the rear end of the ferrule 20. The bare optical fiber 91 a at the tip of the optical fiber 91 is inserted into the fiber hole 21 a of the ferrule body 21.

  However, as shown in FIG. 2, in the optical fiber 91, the flange portion 22 c of the ferrule 20 protrudes inside the front end portion of the housing 40 (inside the plug frame 41 (described later) of the housing 40) by the elastic biasing force of the spring 30. When the ferrule 20 is in contact with the front stopper protrusion 46 (which is in contact with the front stopper protrusion 46 from the rear side of the housing 40), that is, the movement limit of the ferrule 20 to the front side of the housing 40 and the front side of the connector. The end of the bare optical fiber 91a is positioned at the ferrule body 21 when the housing 40 is in the position and no pushing displacement to the rear side of the housing 40 and the rear side of the connector occurs (the position of the ferrule 20 at this time is also referred to as the initial position hereinafter). The tip end surface 21b (ferrule tip end surface) of the ferrule is arranged at a position shifted to the rear side (connector rear side) of the ferrule. (By appending code L13 in extending length L3 of the optical fiber 91 of the present embodiment) extending length L3 from the optical fiber cable 90 terminal unit is set.

As shown in FIG. 2, a portion of the optical fiber 91 other than the bare optical fiber 91a (a portion from the end portion of the optical fiber cable 90 to the bare optical fiber 91a. A portion where the coating (covering material) of the optical fiber 91 is not removed. Hereinafter, the boundary between the covering portion 91b) and the bare optical fiber 91a is an expansion in which the rear end portion of the fiber hole 21a of the ferrule body 21 is expanded so that the end portion of the covering portion 91b of the optical fiber 91 can be accommodated. It arrange | positions in the hole 21e. The inner diameter of the expansion hole 21 e is substantially the same as the outer diameter of the covering portion 91 b of the optical fiber 91.
A portion of the fiber hole 21a of the ferrule body 21 other than the expansion hole portion 21e (a portion on the tip side from the expansion hole portion 21e) is a main hole portion 21f that is a fine hole for positioning the bare optical fiber 91a with high accuracy. It is said that. Further, between the main hole portion 21f and the expanded hole portion 21e, there is provided a tapered hole portion 21g that is tapered toward the main hole portion 21f side from the expanded hole portion 21e side. The fiber hole 21a is configured such that a main hole portion 21f on the front end side and an expansion hole portion 21e on the rear end side are communicated with each other via a tapered hole portion 21g.

A ferrule 81 of the optical connector 80 (second optical connector) on the connection partner side shown in FIGS. 1A to 1C is a capillary-like one used for a single-fiber optical connector. An optical fiber 82 a is inserted and fixed to the ferrule 81.
The optical connector 80 is configured such that the tip surface of the optical fiber 82 a is positioned so as to align with the tip surface of the ferrule 81.

  Pushback of the ferrule 20 due to the abutting force when the optical connector 80 on the connection partner side is abutted with the ferrule 81 is first inserted into the fiber hole 21a of the ferrule body 21 so as to be movable in the direction of the central axis of the fiber hole 21a. By sliding between the bare optical fiber 91a and the inner surface of the fiber hole 21a (sliding also occurs between the inner surface of the expansion hole 21e and the covering portion 91b of the optical fiber 91), the optical fiber 91 The ferrule 20 moves to the rear side of the connector while maintaining the state of extending straight from the end portion of the optical fiber cable 90 due to the rigidity of the fiber 91 itself. Then, after the abutting of the bare optical fiber 91a against the optical fiber 82a inserted and fixed to the ferrule 81 of the optical connector 80 on the connection partner side occurs, the optical fiber cable is further moved by the further movement of the ferrule 20 to the rear side of the connector. The optical fiber 91 is bent between the 90 terminal portion and the ferrule body 21.

  Further, as shown in FIG. 2, a step portion (specifically, a tapered hole portion 21g shown in FIG. 2) between the main hole portion 21f (see FIG. 2) of the fiber hole 21a and the expansion hole portion 21e and light The distance between the end portion of the optical fiber cable 90 of the optical connector 10 and the distal end surface 21b of the ferrule 21 at the initial position is L1 (this embodiment). In the embodiment, the distance L1 is set larger than the difference (L1-L3, L11-L13) between the distance L1 and the extension length L3 of the optical fiber 91. For this reason, in this optical connector 10, as shown in FIGS. 1 (b) and 1 (c), the ferrule 20 is moved away from the initial position by the abutting force at the time of abutting with the ferrule 81 of the optical connector 80 on the connection partner side. When pushed into the rear side (rear side of the housing 40, rear side of the connector) (pushback) and the ferrule 20 reaches the movement limit position to the rear side of the housing 40 (rear side of the connector), that is, the flange of the ferrule 20 The portion 22c is brought into contact with a front end portion 42c of a stop ring portion 42 (described later) fixedly inserted and fitted to a rear end portion of a sleeve-like plug frame 41 (described later) of the housing 40 (of the stop ring portion 42). Even when it comes into contact with the front end portion 42c from the front side), the covering portion at the boundary between the covering portion 91b of the optical fiber 91 and the bare optical fiber 91a When the end face of the covering material 1b hits a step portion (specifically, a tapered hole portion 21g shown in FIG. 2) between the main hole portion 21f (see FIG. 2) and the expansion hole portion 21e of the fiber hole 21a. Therefore, it is possible to reliably realize the abutting of the bare optical fiber 91a against the optical fiber 82a that is inserted and fixed to the ferrule 81 of the optical connector 80 on the connection partner side.

The front end portion 42c of the stop ring portion 42 moves the ferrule 20 to the rear side of the housing by contacting the flange portion 22c of the ferrule 20 pushed from the initial position toward the rear end portion of the housing 40. It functions as a rear stopper protrusion to be regulated.
The position of the ferrule 20 when the flange portion 22c of the ferrule 20 pushed from the initial position to the rear side of the connector comes into contact with the end face 42h of the front end portion 42c of the stop ring portion 42 is the rear of the ferrule 20 in the optical connector 10 It is the push limit position to the side.

  In the present invention, when the ferrule 20 is in the initial position, the boundary between the covering portion 91b of the optical fiber 91 and the bare optical fiber 91a is located behind the ferrule body 21 and is not in the expansion hole portion 21e. Including. Further, in this way, the boundary between the covering portion 91b of the optical fiber 91 and the bare optical fiber 91a is located behind the ferrule body 21 when the ferrule 20 is in the initial position, and the ferrule 20 is pushed in when the connector is connected. Therefore, the expansion hole 21e may be inserted when it is displaced slightly rearward from the initial position (see, for example, FIG. 1B).

  The optical connector 10 is an outer-grip-type field assembly optical connector, and the position of the boundary portion with respect to the ferrule 20 is set when the optical connector 10 is provided (assembled) at the terminal portion of the optical fiber cable 90. This can be done by setting the length of the optical fiber 91 exposed at the portion and the length (cover removal length) of the bare optical fiber 91a exposed at the tip of the optical fiber 91.

As shown in FIG. 2, the housing 40 includes a sleeve-like plug frame 41 and a rear unit 43 having a sleeve-like stop ring portion 42 fitted and fixed inside the rear end portion of the plug frame 41. It is configured.
The rear unit 43 includes the stop ring part 42 and a base part 44 extending from the rear end of the stop ring part 42 to the rear side (FIG. 1 (a) to (c), right side in FIG. 2), The retaining cover 45 is pivotally attached to the rear end portion of the stop ring portion 42.

  As shown in FIG. 2, the rear unit 43 has a stop ring portion 42 inserted from the rear end of the plug frame 41 to the inside thereof, and a locking projection 42 d protruding from the outer periphery of the stop ring portion 42. By being inserted into the locking hole 41 a at the rear end of 41 and being engaged with the plug frame 41, it is fitted and fixed so as to be assembled to the rear end of the plug frame 41.

An expansion hole portion 42f is formed on the inner side of the stop ring portion 42 by expanding the front end portion of the stop ring portion inner hole 42e that penetrates the stop ring portion 42. A ring-shaped spring receiving surface 42g (FIG. 2) is provided as a step surface between the hole portion 42f and the portion other than the extended hole portion 42f of the stop ring portion inner hole 42e.
The spring 30 of the optical connector 10 is interposed between the flange portion 22c of the ferrule 20 and the spring receiving surface 42g.

The flange portion 22c of the ferrule 20 is provided between the front end portion 42c of the stop ring portion 42 and a front stopper protrusion 46 that protrudes inside the front end portion of the plug frame 41 (FIG. 1). (A)-(c) and the left-right direction in Drawing 2. In other words, it is provided so that movement is possible in the direction of the central axis of housing 40. The front stopper protrusion 46 is disposed at a position separated from the front end portion 42c of the stop ring portion 42 toward the connector front side.
As shown in FIG. 2, a clearance C is secured between the front end portion 42 c of the stop ring portion 42 and the front stopper projection 46 to allow the flange portion 22 c to move in the front-rear direction of the connector relative to the housing 40. . In the optical connector 10, the movable amount of the flange portion 22 c due to the clearance C is the movable amount of the ferrule 20 in the longitudinal direction of the connector.

Next, the cable retaining portion 60 will be described.
The cable retaining portion 60 is a storage case portion constituted by the base portion 44 and the retaining cover 45 of the rear unit 43, and an optical fiber cable 90 terminal portion and the optical fiber cable 90 are provided in the storage case portion. The outer gripping member 50 fixed to the terminal portion is housed and held. The jacket gripping member 50 functions as a gripping part that is provided in the cable holding part 60 (storage case part) and holds the optical fiber cable 90 terminal part to the housing 40.

As shown in FIG. 3, the platform 44 specifically includes a front-rear direction of the housing 40 (more specifically, a sleeve-shaped housing main body 40 </ b> A formed by the plug frame 41 and the stop ring portion 42. Side plate portions 44b are erected on both sides of an elongated plate-like main plate portion 44a extending along the central axis direction). The pair of side plate portions 44b are provided over the entire length in the longitudinal direction of the main plate portion 44a, and the platform portion 44 has an elongated structure that is U-shaped in cross section and extends in the front-rear direction of the housing 40.
The end portion of the optical fiber cable 90 and the covering member 50 are disposed between the pair of side plate portions 44b.

As shown in FIG. 12, the jacket gripping member 50 is fitted between a rear end protrusion 44 d protruding from the rear end of the base portion 44 and a rear end portion of the stop ring portion 42. It arrange | positions and the displacement to the connector front-back direction (center axis direction of the housing 40) is controlled by this.
As shown in FIG. 3, in the illustrated optical connector 10, the rear end protrusion 44 d specifically protrudes from the rear end of the main plate portion 44 a of the base portion 44. However, the rear end protrusion 44 d may be configured to protrude from the side plate portion 44 b of the base portion 44.

FIG. 4 shows an example of the envelope gripping member 50.
The jacket gripping member 50 is an integrally molded product made of plastic, has an elongated gripping block portion 51 in which a cable fitting groove 51a for fitting and fixing the end portion of the optical fiber cable 90 is formed, and the gripping The block portion 51 has a schematic configuration including an L-shaped plate-like lid portion 53 provided via a thin portion 52 that functions as a hinge portion.

The grip block 51 includes an elongated block main body 51e having a structure in which side wall portions 51c and 51d protrude in parallel with each other over the entire length in the longitudinal direction of the bottom wall portion 51b on both sides of an elongated plate-like bottom wall portion 51b. The block main body 51e has a pair of protruding plate portions 51f formed in a protruding state so as to extend the side wall portions 51c and 51d at one end in the longitudinal direction.
The cable fitting groove 51a is formed over the entire length in the longitudinal direction of the block body 51e. The pair of side wall portions 51c and 51d of the block main body 51e are wall portions on both sides of the block main body 51e via the cable fitting groove 51a.
Both ends in the longitudinal direction of the cable fitting groove 51a are opened at both ends in the longitudinal direction of the block body 51e.

The lid portion 53 has a thin-walled portion 52 interposed at one of a pair of side wall portions 51c and 51d protruding from the bottom wall portion 51b (here, a side wall portion denoted by reference numeral 51c; hereinafter also referred to as a first side wall portion). A first lid plate portion 53a connected to each other, and a second lid projecting perpendicularly to the first lid plate portion 53a at the end of the first lid plate portion 53a opposite to the thin-walled portion 52. And a lid plate portion 53b.
Hereinafter, the side wall portion 51d is also referred to as a second side wall portion.

FIG. 3 shows a state in which the lid part 53 is closed to the gripping block part 51 and the jacket gripping member 50 is fixed to the end part of the optical fiber cable 90. FIG. 4 shows a state in which the lid part 53 is opened with respect to the gripping block part 51. Indicates.
In order to attach the outer cover gripping member 50 to the end portion of the optical fiber cable 90, the block main body 51e of the gripping block 51 is opened with the lid 53 open to the gripping block 51 as shown in FIG. After fitting the end portion of the optical fiber cable 90 into the cable fitting groove 51a, the lid portion 53 may be closed to the gripping block portion 51 as shown in FIG.
The optical fiber cable 90 is cut after being cut from a notch 94 (see FIG. 5) formed in the jacket 93, cutting the cut portion of the jacket 93, and the like so that the optical fiber 91 is exposed at the end. Fit into the fitting groove 51a.

  As shown in FIG. 6, the end part of the optical fiber cable 90 fitted in the cable fitting groove 51a is sandwiched between the side wall parts 51c and 51d on both sides via the cable fitting groove 51a. Further, the protruding claws 51g projecting from the pair of side wall portions 51c and 51d bite into the resin coating material 93 (outer jacket) of the end portion of the optical fiber cable 90, so that the end portion of the optical fiber cable 90 becomes the pair of side wall portions. 51c and 51d are firmly held and fixed from both sides.

As shown in FIG. 4, when the lid 53 is open with respect to the grip block 51, the lid 53 is rotatable with respect to the grip block 51 around the thin portion 52. .
The thin portion 52 is formed to extend along the longitudinal direction of the first side wall portion 51c, and the lid portion 53 is rotatable with a rotation axis along the extending direction (longitudinal direction) of the cable fitting groove 51a. It has become.

After the optical fiber cable 90 terminal portion is fitted in the cable fitting groove 51a of the block main body 51e of the gripping block portion 51, the lid portion 53 that is open with respect to the gripping block portion 51 is rotated, so that FIG. When the lid portion 53 is closed to the gripping block portion 51 as shown in FIG. 5, the first lid plate portion 53a of the lid portion 53 opens between the protruding ends of the pair of side wall portions 51c and 51d of the block main body 51e and between them. The second cover plate portion 53b is covered so as to cover the cable fitting groove 51a, and the outer surface of the second side wall portion 51d of the block portion main body 51e of the gripping block portion 51 (surface opposite to the cable fitting groove 51a). It is arranged so as to cover.
This closing is achieved by a locking claw 51h (see FIG. 4) protruding from the outer surface of the second side wall 51d in an engagement hole 53c (see FIG. 4) formed in the second lid plate portion 53b. ). As a result, the lid 53 is locked by the engagement of the locking claw 51h and its rotation is restricted, so that the closed state can be maintained. Further, it is possible to reliably prevent the end portion of the optical fiber cable 90 from protruding between the protruding ends of the pair of side wall portions 51c and 51d of the block main body 51e. Furthermore, the state (see FIG. 1A) in which the protruding claws 53d protruding from the first cover plate portion 53a (see FIG. 4) bite into the jacket 93 of the end portion of the optical fiber cable 90 can be maintained.

As shown in FIG. 3, the jacket gripping member 50 is assembled to the optical fiber cable 90 end so as to surround the optical fiber cable 90 end.
As shown in FIG. 2 and the like, the stop ring portion 42 of the optical connector 10 has a protruding tip from the block main body 51e of the pair of protruding plate portions 51f of the outer cover holding member 50 fixed to the end portion of the optical fiber cable 90. The rear end protrusion 44d of the base 44 is in contact with the end of the bottom wall 51b of the jacket gripping member 50 opposite to the pair of protrusions 51f.

  In addition, as a jacket holding member, the cable fitting groove | channel for fitting and fixing the optical fiber cable 90 terminal part should just be the structure which has a holding block part, and it is specifically limited to the shape of a holding block part and a cover part, etc. There is no. Moreover, as this jacket holding member, the thing without a cover part is also included.

  As shown in FIG. 3, the retaining cover 45 is specifically an elongated member having a U-shaped cross section having a top plate portion 45a and a pair of side plate portions 45b projecting on both sides of the top plate portion 45a. A pair of pivoting piece portions 45c, which are portions of the pair of side plate portions 45b provided in parallel with each other in the longitudinal direction and projecting from the top plate portion 45a, are provided behind the stop ring portion 42. It is pivotally attached to the end.

As shown in FIG. 2, the optical fiber 91 extending from the end portion of the optical fiber cable 90 and inserted in the ferrule 20 has a retaining cover 45 with respect to the base portion 44 as shown in FIG. In the opened state, the optical fiber 91 extended from the end portion of the optical fiber cable 90 from the opening 42a (see FIG. 2) at the rear end of the stop ring portion 42 of the housing 40 of the optical connector body 10A. Is inserted into the housing main body 40 </ b> A and inserted into the fiber accommodation through-hole 23 of the ferrule 20.
Further, the housing 40 is inserted after the outer cover holding member 50 fixed to the end portion of the optical fiber cable 90 is inserted into the through hole 23 for storing the ferrule 20 of the optical fiber 91 extending from the end portion of the optical fiber cable 90. (The housing 40 is oriented in such a way that the cross-sectional opening of the U-shaped base 44 has an opening at the top of the base 44, and the outer gripping member 50 is placed between the pair of side plates 44b. 2 on the main plate portion 44a), as shown in FIG. 2 solid line and FIG. 7, the cable retaining portion 60 is assembled by closing the retaining cover 45 and assembling the cable retaining portion 60 on the base portion 44 of the rear unit 43. The outer gripping member 50 is housed and held at 60.

In other words, the optical connector 10 has an optical fiber disposed on the rear end side of a sleeve-like housing 40 that houses a ferrule 20 in which no optical fiber is inserted (a ferrule having an empty fiber accommodation through-hole 23) and a spring 30. A cable for holding and holding the jacket gripping member 50 fixed to the end portion of the fiber cable 90 together with the end portion of the optical fiber cable 90 while restricting displacement in the direction of the center axis of the housing 40 (center axis of the housing main body 40A). An optical connector main body 10A having a structure having a retaining portion 60 (retaining portion), that is, a structure in which the optical fiber cable 90 (and the optical fiber 91) and the outer covering member 50 are omitted from the optical connector 10 shown in FIG. An optical fiber extending from the end portion of the optical fiber cable 90 that has been prepared and the fixing of the jacket gripping member 50 has been completed. The lever 91 is fed into the housing body 40A from the opening 42a (see FIG. 1 (a)) at the rear end of the stop ring portion 42 of the housing 40 of the optical connector body 10A, and enters the fiber housing through hole 23 of the ferrule 20. The outer gripping member 50 inserted and fixed to the end portion of the optical fiber cable 90 is housed and held in a housing case portion constituted by the base portion 44 and the retaining cover 45.
This optical connector 10 has a configuration (optical connector assembly) in which an optical connector main body 10A is attached to an end portion of an optical fiber cable 90 and assembled.

Before the optical fiber 91 is fed into the housing body 40A, it is cut and the coating of the tip is removed, and the extension length from the end portion of the optical fiber cable 90 and the lead length (coating removal length) of the bare optical fiber 91a are the desired length. Keep it.
The cutting of the optical fiber 91 and the removal of the coating at the tip (leading out of the bare optical fiber 91a) are performed in a state where the covering member 50 is fixed to the end portion of the optical fiber cable 90. Thus, when the outer gripping member 50 is stored and held in the storage case portion, the distance L1 from the end portion of the optical fiber cable 90 of the optical connector 10 to the distal end surface 21b of the ferrule 21 at the initial position (in this embodiment, The difference (L1-L3. L11-L13) between the distance L1 and the extension length L3 of the optical fiber 91 can be accurately ensured.

  The method for assembling the optical connector 10 is not limited to the above.

As shown in FIG. 3, the pair of pivoting piece portions 45c of the retaining cover 45 are pivotally supported by a shaft portion 42b protruding from the rear end portion of the stop ring portion 42, and the retaining cover 45 is mounted on the base portion. In the open state with respect to 44, it is rotatable around the shaft portion 42b at the rear end portion of the stop ring portion 42. The rotation of the retaining cover 45 is perpendicular to the front-rear direction of the housing 40 (more specifically, the central axis direction of the sleeve-shaped housing body 40A formed by the plug frame 41 and the stop ring portion 42), and the platform The rotation is about a rotation axis parallel to the main plate portion 44 a of the portion 44, and can be opened and closed with respect to the base portion 44 by this rotation.
As shown in FIG. 3, a pair of side plate portions 45 b of the retaining cover 45 is provided with engaging claws 44 c projecting on both sides of the base portion 44 so that the retaining cover 45 is attached to the base portion 44. An engagement hole 45d for locking is formed. As shown in the solid line of FIG. 2 and FIG. 7, in the cable retaining portion 60 that houses and holds the end portion of the optical fiber cable 90 and the outer cover gripping member 50, the retaining cover 45 is located between the pair of side plate portions 45b. The pair of side plate portions 44b of the pedestal portion 44 are accommodated and closed to the pedestal portion 44, and the engaging claws 44c protruding from both sides of the pedestal portion 44 are inserted into the engagement holes 45d of the side plate portions 45b. As a result, the engaging claw 44c (see FIGS. 3 and 7) is engaged with the base portion 44, and the release by rotation is restricted. The top plate portion 45a of the retaining cover 45 is disposed on the side opposite to the main plate portion 44a of the base portion 44 via the end portion of the optical fiber cable 90 and the outer cover holding member 50 in a direction along the main plate portion 44a. The holding member 50 is pressed into the main plate portion 44a.

  A notch portion 45e for allowing the optical fiber cable 90 to pass through is formed on the inner side surrounded by the top plate portion 45a and the pair of side plate portions 45b on the side opposite to the pivot piece 45c of the retaining cover 45. An end plate 45f is provided, and the optical fiber cable 90 is provided so as to extend from the retaining cover 45 through the notch 45e.

  The cable retaining portion 60 may be configured such that the outer cover gripping member 50 is pressed and fixed to the main plate portion 44a of the base portion 44 by the top plate portion 45a of the retaining cover 45. Allows a slight displacement in the direction perpendicular to the main plate portion 44a of the base portion 44 between the top plate portion 45a of the retaining cover 45 and the main plate portion 44a of the base portion 44 (however, A configuration in which the outer cover gripping member 50 is accommodated between the end protrusion 44d and the rear end of the stop ring portion 42 so that the outer gripping member 50 is fitted is also possible.

Specifically, FIGS. 1A to 1C illustrate a socket-plug optical connector coupling structure.
Specifically, an optical connector 80 (second optical connector) on the connection partner side shown in FIGS. 1A to 1C is a sleeve-like housing 83 that stores a ferrule 81, as shown in FIG. 8 is a socket having a configuration in which the inner side of the front end portion (the right end portion of the housing 83 in FIG. 8A) is a connector fitting hole 84 into which the optical connector 10 (optical connector plug) is inserted and fitted. . Hereinafter, the optical connector 80 is also referred to as a socket.
The socket 80 is assembled at the tip of an optical fiber 82 (for example, an optical fiber core wire, an optical fiber strand, or an optical fiber cord). The ferrule 81 has a coating material at the tip of the optical fiber 82 removed. The exposed bare optical fiber 82a is inserted and fixed. The end of the bare optical fiber 82 a is aligned with the end face of the ferrule 81.

  The socket 80 is an optical fiber cable having a structure in which an optical fiber such as an optical fiber core or an optical fiber is embedded in a resin coating material together with a tensile body such as a tensile fiber vertically attached to the optical fiber. What was assembled in the terminal part is also employable. In this case, the socket includes a cable holding portion that holds and holds the optical fiber cable end portion in the direction of the central axis of the housing 83, for example, an optical fiber cable similar to the cable holding portion of the optical connector 10 It is also possible to adopt a configuration in which a base portion and a retaining cover that constitute a storage case portion for storing and holding the outer gripping member fixed to the terminal portion are provided at the rear end of the housing 83.

  The ferrule 81 of the socket 80 protrudes from the back of the connector fitting hole 84 toward the front side of the housing 83 (the right side of the housing 83 in FIG. 8A), and the tip thereof is disposed in the connector fitting hole 84. Has been. The ferrule 81 is elastically urged toward the front side of the housing 83 (the right side of the housing 83 in FIG. 8A) by a spring 85 (coil spring) incorporated in the housing 83.

  The optical connector coupling structure illustrated in FIGS. 8A and 8B includes an optical connector 10 (first optical connector) and a socket 80 (second optical connector), and is illustrated in FIG. 8B. As described above, the optical connector 10 is inserted and fitted into the connector fitting hole 84 of the socket 80 to assemble the optical connector coupling unit 71 in which the optical connector 10 and the socket 80 are coupled to each other. An optical connection between 91 and 82 is realized.

As shown in FIG. 8B, when the optical connector 10 is inserted and fitted into the connector fitting hole 84 of the socket 80 (an optical connector coupling unit 71 is assembled), the ferrule 81 of the socket 80 is fitted. The ferrule 20 of the optical connector 10 is abutted (the abutment surfaces 21 and 81a of the ferrules 20 and 81 are abutted against each other), and the springs 30 and 85 of the optical connectors 10 and 80 are compressed by the pushback of the ferrules 20 and 81, respectively. The elastic force of the springs 30 and 85 gives the butt force of the ferrules 20 and 81 in the butt state. The optical connector 10 is configured such that the housing body 40A (specifically, the plug frame 41) of the housing 40 of the optical connector 10 and an elastic claw projecting from one of the sockets 80 are engaged with the other of the housing body and the socket 80. Is locked to the socket 80, so that the optical connector 10 is prevented from coming out of the connector fitting hole 84.
The elastic claws are not limited to projecting to only one of the housing main body 40A and the socket 80 of the optical connector 10, and may be projecting to both the housing main body 40A and the socket 80 of the optical connector 10.

The elastic claw for locking the optical connector 10 inserted into the connector fitting hole 84 with respect to the socket 80 and restricting the optical connector 10 from coming out of the connector fitting hole 84 is not particularly limited. A well-known configuration used in a connector / socket fitting / coupling structure can be applied.
As this elastic nail | claw, the thing of the structure which an operator can perform engagement cancellation | release operation with a finger | toe from the optical connector coupling unit 71 outer side, such as a latch by which the lever for engagement cancellation | release operation protrudes, is employable, for example. In the case of an elastic claw that can be disengaged, by performing the disengagement operation, the optical connector 10 fitted in the connector fitting hole 84 of the socket 80 can be removed from the socket 80.

  Further, as this elastic claw, it is possible to project into the connector fitting hole 84 of the socket 80 and engage with the housing main body 40A of the optical connector inserted and fitted into the connector fitting hole 84. good. In this case as well, the elastic claw can be disengaged from the outside of the optical connector coupling unit 71 (for example, between the optical connector 10 and the elastic claw engaged with the optical connector 10 by inserting the elastic claw with respect to the optical connector 10). Use of a disengagement tool having an insertion piece for disengaging the engagement is possible. Further, when an optical connector having a structure having a tab movable in the front-rear direction of the connector constituting the slide lock mechanism is employed, the light inserted and fitted into the connector fitting hole 84 of the socket 80 as an elastic claw A configuration in which engagement with the optical connector can be released by moving the connector knob to the rear side of the connector can be adopted.

  As shown in FIG. 1A, the optical connector 10 has a distance L11 from the end portion of the optical fiber cable 90 held by the cable holding portion 60 to the ferrule tip surface 21b when the ferrule 20 is in the initial position. When the flange portion 22c of the ferrule 20 comes into contact with the end surface 42h of the front end portion 42c of the stop ring portion 42 of the housing 40 (see FIG. 1C), the end surface of the ferrule The distance L12 to 21b and the extension length (the length including the bare optical fiber 91a) L13 of the optical fiber 91 of the optical fiber cable 90 from the end portion of the optical fiber cable 90 satisfy L12 <L13 <L11 It has become.

In the optical connector 10, as described above, when the ferrule 20 is in the initial position, the tip of the optical fiber 91 is in a position shifted rearward from the ferrule tip surface 21b.
Moreover, the terminal of the coating part 91b of the optical fiber 91 is set by setting the extension length L13 of the optical fiber 91 from the terminal part of the optical fiber cable 90 and the length (coating removal length) of the bare optical fiber 91a at the tip of the optical fiber 91. The boundary between the bare optical fiber 91a and the covering portion 91b is always in the expansion hole 21e of the ferrule body 21, including when the ferrule 20 is in the initial position and when it is in the limit position for moving to the rear side of the connector. So that it does not hit the step portion (specifically, the tapered hole portion 21g shown in FIG. 2) between the main hole portion 21f (see FIG. 2) and the expansion hole portion 21e of the fiber hole 21a. It has become.

  Further, here, as the socket 80, the ferrule 81 is connected to the rear end side of the housing 83 (the side where the optical fiber 82 is extended. The side opposite to the front end where the connector fitting hole 84 is opened). Moveable amount ΔX by pushing (refer to FIG. 1 (c), pushable back amount of ferrule 81), that is, a position when pushing displacement toward the rear end side of housing 83 is not given (ferrule 81 is shown in FIG. 8 (a)). The distance from the position shown below (hereinafter also referred to as the initial position) to the push-down limit position (the position where the spring 85 is the compression limit in the optical connector 80 in the illustrated example) is the optical fiber of the optical connector 10. The distance L11 from the cable 90 terminal portion to the distal end surface 21b of the ferrule 21 at the initial position and the flange portion 22c of the ferrule 20 are the housing 40 A distance L12 from the end portion of the optical fiber cable 90 to the ferrule tip end surface 21b when contacted with the front end portion 42c of the stop ring portion 42 (see FIG. 1 (c), when the ferrule 20 is in the push-in limit position). A difference larger than the difference (a possible amount of pushback of the ferrule 20) is used.

As shown in FIG. 1A, the pushback possible amount of the ferrule 20 (movable amount in the front-rear direction of the connector, L11-L12) can be set as appropriate, but is preferably 0.2 mm or more and less than 1.0 mm. For example, it is set in the range of 0.2 to 0.4 mm.
On the other hand, as shown in FIG. 1C, the movable amount ΔX of the ferrule 81 of the counterpart optical connector 80 is 0.5 mm or more larger than the movable amount of the ferrule 20 of the optical connector 10 in the longitudinal direction of the connector. It is preferably 0 mm or more. The movable amount ΔX of the ferrule 81 of the mating optical connector 80 (here, the socket) is such that the ferrule 81 is pushed into the connector rear side (the connector rear side of the mating optical connector 80) when the optical connectors 10 and 80 are connected to each other. The size is secured so as not to reach the limit position. The upper limit value of the movable amount ΔX is not particularly limited, but is preferably 5 mm or less, for example, in view of avoiding unnecessary enlargement of the optical connector 80 and practicality.

  As shown in FIGS. 1A to 1C, the optical connector 10 is fitted into the socket 80 to be coupled (assembled with the optical connector coupling unit 71). As the connector 10 is inserted, the ferrule 20 of the optical connector 10 and the ferrule 81 of the socket 80 are brought into contact with each other, and pushback of the ferrules 20 and 81 of the optical connectors 10 and 80 occurs. Then, the optical connector 10 is fitted into the connector fitting hole 84 of the socket 80, and the elastic claw protruding from one of the housing main body 40A and the socket 80 of the optical connector 10 is engaged with the other of the housing main body and the socket 80. Thus, the connection between the socket 80 and the optical connector 10 is realized.

When the ferrule 20 of the optical connector 10 is in the initial position, the optical fiber 91 extending from the end portion of the optical fiber cable 90 is between the end portion of the optical fiber cable 90 and the ferrule body 21 of the ferrule 20. It is in a state extending straight from the terminal portion.
When the optical connector 10 is inserted into the connector fitting hole 84 of the socket 80, the front end surface 21b of the ferrule 20 of the optical connector 10 comes into contact with the front end surface 81a of the ferrule 81 of the optical connector 80 on the connection partner side. As the optical connector 10 continues to be pushed into the connector fitting hole 84, the ferrule 20 slides between the bare optical fiber 91a inserted into the fiber hole 21a of the ferrule body 21 and the inner surface of the fiber hole 21a (expansion). (The sliding between the inner surface of the hole 21e and the terminal portion 91b of the optical fiber 91 also occurs).
Then, the optical fiber 82a (bare optical fiber) that is inserted and fixed to the ferrule 81 of the optical connector 80 on the connection partner side projects into the bare optical fiber 91a that is inserted into the ferrule body 21 of the ferrule 20 of the optical connector 10. After being applied, the socket 80 and the optical connector 10 are fitted and joined by further pushback of the ferrule 20. When the fitting and coupling between the socket 80 and the optical connector 10 are completed, the optical fiber 91 is bent between the end portion of the optical fiber cable 90 and the ferrule body 21.

When the ferrule 20 of the optical connector 10 pushes back, pushback of the ferrule 81 of the counterpart optical connector 80 to the housing 83 also occurs.
Further, the optical fiber 91 of the optical connector 10 has a terminal portion of the optical fiber cable 90 due to the rigidity of the optical fiber 91 itself until the optical fiber 82a inserted and fixed to the ferrule 81 of the counterpart optical connector 80 is abutted. Keep the state extending straight from.

As shown in FIG. 2, the difference (L11−L13; hereinafter) between the distance L11 from the end portion of the optical fiber cable 90 of the optical connector 10 to the distal end surface 21b of the ferrule 21 at the initial position and the extension length L13 of the optical fiber 91. , Which is also referred to as offset amount) is, for example, 0.1 mm, but is not limited thereto, and may be smaller than 0.1 mm or larger than 0.1 mm.
However, the offset amount is a butt connection between the optical fiber 82a inserted and fixed to the ferrule 81 of the counterpart optical connector 80 and the optical fiber 91 inserted to the ferrule 20 of the optical connector 10 when the connector is fitted. A movable amount (L11−) of the ferrule 20 in the longitudinal direction of the connector so that the optical fiber 91 can be bent with a size sufficient to ensure an abutment force (abutment force between optical fibers) sufficient to realize (optical connection). It is set in a range smaller than L12).

  As a result of verification by the present inventor, the distance between the ferrule body 21 of the ferrule 20 and the end portion of the optical fiber cable 90 (distance when the ferrule 20 is in the initial position) is 20 mm, and the optical fiber 91 is an optical fiber having a diameter of 250 μm. In the case of a strand, the difference between the distance L12 from the end of the optical fiber cable 90 to the distal end surface 21b of the ferrule 20 at the push-in limit position and the extension length L13 of the optical fiber 91 (L13-L12; hereinafter, optical fiber). 91 (also referred to as the pushback amount at the tip of 91) is about 0.1 mm, and the tip of the optical fiber 82 (bare optical fiber 82a) that is inserted and fixed to the ferrule 81 of the mating optical connector 80 when the connector is fitted. A protrusion sufficient to realize a butt connection (optical connection) with the optical fiber 91 inserted in the ferrule 20 of the connector 10 It has been found that can be secured against force (abutting force between the optical fiber). In addition, when the pushback amount at the tip of the optical fiber 91 is 0.1 mm, the optical fiber 91 is in a case where the distance between the ferrule body 21 of the ferrule 20 and the optical fiber cable 90 end is in the range of 10 to 25 mm. Thus, it was confirmed that an abutting force sufficient to realize the butted connection between the two 82 was obtained.

In the optical connector coupling structure according to the present invention, when the optical connector coupling unit 71 is assembled by fitting the socket 80 and the optical connector 10, the ferrule 20 of the optical connector 10 is shifted to the front side of the connector from the pushing limit position. Either a configuration arranged at the position or a configuration where the ferrule 20 of the optical connector 10 is arranged at the push-in limit position can be adopted.
Here, the latter configuration is adopted in which the ferrule 20 of the optical connector 10 is disposed at the push-in limit position when the connector is fitted (when the optical connector coupling unit 71 is assembled).

  As shown in FIGS. 1B and 1C, in the optical connector 10 and the socket 80 described here, the ferrule 20 of the optical connector 10 inserted into the connector fitting hole 84 of the socket 80 is pushed into the rear side of the connector. After reaching the limit position, the pushing of the optical connector 10 into the connector fitting hole 84 of the socket 80 is further continued, so that the fitting and coupling of the optical connector 10 to the socket 80 are achieved. . After the ferrule 20 of the optical connector 10 inserted into the connector fitting hole 84 of the socket 80 reaches the push-down limit position to the rear side of the connector, the ferrule of the socket 80 among the ferrule 20 of the optical connector 10 and the ferrule 81 of the socket 80 Only 81 is pushed back as the optical connector 10 is pushed into the connector fitting hole 84 of the socket 80 (the housing 83 of the socket 80 moves relative to the ferrule 81 relative to the front side of the connector).

  When the fitting and coupling between the socket 80 and the optical connector 10 are completed, a desired butting force is obtained between the ferrules 20 and 81 that are in a butting state due to the elasticity of the springs 30 and 85 of the optical connectors 10 and 80. . However, the ferrule 20 of the optical connector 10 is disposed at the push-in limit position.

The optical connector 10 is configured such that when the ferrule 20 is in the initial position, the tip of the optical fiber 91 is in a position shifted to the rear side from the ferrule tip surface 21b. The size of the bend formed in the optical fiber 91 between the end portion of the optical fiber cable 90 and the ferrule body 21 of the ferrule 20 can be kept small.
For example, in the optical connector 100 of the second prior art described above, the ferrule 110 of the protruding portion 24 that protrudes from the joining end face 14 of the ferrule 110 of the optical fiber 211 and the ferrule 110 of the optical fiber 211 when connected to another optical connector. In this configuration, the optical fiber 211 is bent by being pushed. On the other hand, the optical connector 10 is inserted into the ferrule 81 of the counterpart optical connector 80 into the optical fiber 91 inserted in the ferrule main body 21 by pushback of the ferrule 20 when connecting to the counterpart optical connector 80. After the optical fiber 82a that is inserted and fixed is abutted, the tip of the optical fiber 91 (the tip of the bare optical fiber 91a) is pushed back together with the ferrule 20 to bend the optical fiber 91.

In this optical connector 10, the pushback amount at the tip of the optical fiber 91 (movement distance to the rear side of the connector) when connected to another optical connector 80, that is, the push-in limit position from the end portion of the optical fiber cable 90. The difference (L13-L12) between the distance L12 to the tip surface 21b of the ferrule 20 and the extension length L13 of the optical fiber 91 is the amount of pushback from the initial position of the ferrule 21 (movement from the initial position to the rear side of the connector). Compared with the distance L11−L12), the difference (L11−L13) between the distance L11 from the end portion of the optical fiber cable 90 to the distal end surface 21b of the ferrule 21 at the initial position and the extension length L13 of the optical fiber 91 ,small.
For this reason, as compared with the optical connector 100 of the second prior art described above, it is possible to easily realize downsizing of the bending formed in the optical fiber 91.

  In this optical connector 10, the distance L11 from the end portion of the optical fiber cable 90 of the optical connector 10 to the distal end surface 21b of the ferrule 21 at the initial position, and the ferrule at the push-in limit position from the end portion of the optical fiber cable 90. When the difference from the distance L12 to the distal end surface 21b of 20 (the movable amount of the ferrule 20 in the front-rear direction of the connector) is set to 0.2 mm or more and less than 1.0 mm as described above, for example, when connecting to another optical connector The pushback amount at the tip of the optical fiber 91 can be reliably suppressed to less than 1.0 mm.

  Further, according to the optical connector coupling structure in which the ferrule 20 of the optical connector 10 is disposed at the push-in limit position when the optical connector coupling unit 71 is assembled by fitting the socket 80 and the optical connector 10, the optical connector coupling When the unit 71 is assembled, the flange portion 22c of the ferrule 20 of the optical connector 10 is connected to the rear stopper protrusion of the housing 40 of the optical connector 10 (the front end portion 42c of the stop ring portion 42 in this embodiment). Therefore, the ferrule 20 can be reliably stopped at the push-in limit position. For this reason, for example, when the optical connector coupling unit is assembled, the ferrule 20 of the optical connector 10 is disposed at a position shifted to the front side of the connector from the push-in limit position (the elastic biasing force of the springs of the optical connectors connected to each other). Compared to the configuration in which the position of the ferrule 20 is determined by the balance), the optical fiber 91 of the optical connector 10 can be surely formed with a desired amount of bending.

Therefore, in the optical connector coupling structure, from the end portion of the optical fiber cable 90 of the optical connector 10 to the distal end surface 21b of the ferrule 21 at the initial position, in order to avoid the bending of the optical fiber 91 more than necessary. Difference between the distance L11 of the optical fiber cable 90 and the distance L12 from the end portion of the optical fiber cable 90 to the distal end surface 21b of the ferrule 20 at the push-in limit position (L11-L12, the movable amount of the ferrule 20 in the longitudinal direction of the connector), and the optical fiber The difference (L13-L12) between the distance L12 from the end of the cable 90 to the distal end surface 21b of the ferrule 20 at the push-in limit position and the extension length L13 of the optical fiber 91. In this optical connector coupling structure, The pushback amount at the tip of the optical fiber 91 at the time of connecting each other matches this) (Set to less than 1.0mm or 0.2mm to L11-L12, for example, as described above) to devote to a particular advantageous. For example, even when the pushback amount (L13-L12) at the tip of the optical fiber 91 when the optical connectors 10 and 80 are connected to each other is a small dimension of about 0.1 mm, the size corresponding to this pushback amount. Can be reliably formed in the optical fiber 91, and the optical fiber 91 inserted in the ferrule body 21 of the optical connector 10 and the optical fiber 82a inserted and fixed in the ferrule 81 of the counterpart optical connector 80 are matched. The abutting force required for realizing the connection (optical connection) can be obtained.
Therefore, the movable amount (L11-L12) of the ferrule 20 in the longitudinal direction of the connector, the distance L12 from the end portion of the optical fiber cable 90 to the distal end surface 21b of the ferrule 20 at the push-in limit position, and the extension length of the optical fiber 91 By reducing the difference (L13−L12) from L13, it is possible to easily realize suppression of light loss due to bending.

  In addition, according to the optical connector 10, as described above, when the ferrule 20 is in the initial position, the tip of the optical fiber 91 is in a position shifted to the rear side from the ferrule tip surface 21b. 2 Compared with the configuration in which the ferrule protrudes from the optical fiber as in the prior art optical connector, the optical fiber 91 inserted into the ferrule 20 when the connector is fitted (when connected to another optical connector). There is also an advantage that the tip is hard to be damaged.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described.
In the above-described embodiments, the socket-plug coupling type optical connector coupling structure has been described. However, the present invention is not limited to this, and as shown in FIGS. 9A and 9B, a plug-adapter-plug coupling system is used. It can also be applied to the optical connector coupling structure.

  As shown in FIG. 1A and the like, the optical connector 10 according to the first embodiment houses the ferrule 20 at a position shifted from the front end of the housing main body 40A toward the rear side of the connector. The front end portion of the ferrule main body 21 is not protruded from the front end of the housing main body 40A. As shown in FIG. 9A, the optical connector 10B (optical connector plug) extends from the front stopper protrusion 46 of the plug frame 41 to the front side instead of the plug frame 41 of the optical connector 10 described above. A plug frame 41A having a configuration in which the size of the sleeve-like portion (size in the central axis direction) is shortened is adopted, and a sleeve-like housing body 40B constituted by the plug frame 41A and the stop ring portion 42 of the rear unit 43 is provided. The ferrule 20 is housed such that the front end of the ferrule body 21 protrudes from the front end of the plug frame 41A (when the ferrule 20 is in the initial position).

Reference numeral 40 'in the figure denotes a housing of the optical connector 10B. The housing 40 ′ is constituted by a plug frame 41 A and a rear unit 43.
The plug frame 41A has the same configuration as the plug frame 41 of the optical connector 10 except for the dimensions of the sleeve-like portion extending from the front stopper projection 46 to the front side. The configuration of the optical connector 10B other than the plug frame 41A is the same as that of the optical connector 10 described above.

  As shown in FIGS. 9A and 9B, the optical connector coupling structure described here includes the optical connector 10B (first optical connector), and a coated optical fiber such as an optical fiber core and an optical fiber. An optical connector 12 (optical connector plug; second optical connector) assembled at the tip of an optical fiber 12a is inserted and fitted from both sides facing the optical connector adapter 11 to be connected to each other. By connecting the optical connector 10B and the optical connector 12a to each other by the optical connector adapter 11, the optical connector coupling unit 72 including the optical connector 10B, the optical connector 12a, and the optical connector adapter 11 is assembled, and the optical fibers 91 and 12a are assembled. An optical connection between them is realized.

As the optical connector 12, for example, a well-known single-core optical connector such as an SC-type optical connector or a MU-type optical connector can be adopted.
This optical connector 12 has a structure in which a ferrule 12c and a spring 12d (coil spring) for elastic biasing of the ferrule 12c are housed in a sleeve-shaped housing 12b. The optical fiber 12a is, for example, a coated optical fiber such as an optical fiber core or an optical fiber, and the ferrule 12c includes a bare optical fiber 12a1 that is opened by removing the coating material at the tip of the optical fiber 12a. Insertion is fixed. The ferrule 12c has a capillary shape used for a single-fiber optical connector. The bare optical fiber 12a1 is positioned and fixed to the ferrule 12c so that the tip thereof is aligned with the tip surface 12e of the ferrule 12c.
The optical connector 12 is an optical fiber cable having a configuration in which an optical fiber such as an optical fiber core or an optical fiber is embedded in a jacket and integrated with a strength member such as a strength fiber vertically attached to the optical fiber. What was assembled in the terminal part, for example, the thing of the same composition as optical connector 10B, is also employable.

The ferrule 12c is elastically urged to the front side of the housing 12b (the side opposite to the rear end portion from which the optical fiber 12a is extended) by the spring 12d, and the connector rear side (rear end side of the housing 12b) ).
However, the optical connector 12 has a movable amount due to the pushing of the ferrule 12c, that is, a position when the pushing displacement toward the rear side of the connector is not given (the position where the ferrule 12a is shown in FIG. 9A, the initial position). The distance to the rear pushing limit position (the position where the spring 12d is the compression limit in the case of the optical connector 12 shown in the drawing) is the movable amount of the ferrule 20 of the optical connector 10B (from the end of the optical fiber cable 90 to the initial position). When the distance L11 (see FIG. 2) to the tip surface 21b of the ferrule 21 at the position and the flange portion 22c of the ferrule 20 abuts on the front end portion 42c of the stop ring portion 42 of the housing 40 (the ferrule 20 is pushed in) From the end of the optical fiber cable 90 (when in the limit position) to the ferrule tip surface 21b. It is used greater than the difference) between the distance L12 of. In the optical connector coupling unit 72 in which the optical connector 10B and the optical connector 12a are connected to each other by the optical connector adapter 11, the ferrules 20 and 12b of the optical connectors 10B and 12 in the optical connector adapter 11 are connected to each other. , The ferrule 20 of the optical connector 10B is arranged at the push-in limit position, and the optical fiber 91 is bent between the end portion of the optical fiber cable 90 and the ferrule body 21 of the ferrule 20, and the optical fiber 91, Butt connection of 12a is realized.

  The optical connector coupling structure according to the present invention employs an optical connector 12 in which the movable amount by pushing the ferrule 12c is equal to or smaller than the movable amount of the ferrule 20 of the optical connector 10B. When the assembly 72 is assembled, a configuration is also included in which the ferrule 20 of the optical connector 10B is disposed at a position shifted to the front side of the connector from the pushing limit position.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
The optical connector according to the present invention is not limited to the one assembled to the end portion of the optical fiber cable 90, and has a constitution assembled to the end of the optical fiber such as an optical fiber core wire or an optical fiber cord. Also good.
As an example, FIG. 10 shows an optical connector 10C according to a third embodiment of the present invention. In the figure, components similar to those of the optical connector 10 of the first embodiment are denoted by common reference numerals, and detailed description thereof is omitted.

As shown in FIG. 10, the optical connector 10 </ b> C is assembled at the tip of a single optical fiber core wire 13.
The optical connector 10C employs a housing 40C having a structure using a sleeve-like stop ring 48 instead of the rear unit 43 of the optical connector 10 of the first embodiment described above, and the ferrule 20 and the spring 30 are used in the housing 40C. The mechanical splice 49 (described later) is housed.

The housing 40C is configured such that a stop ring 48 is fitted and fixed to the rear end portion of the plug frame 41 of the optical connector 10 described above.
The stop ring 48 is fitted in and fixed to the rear end of the plug frame 41 and is fixed to the rear side of the connector from the plug frame 41 (the right side in FIG. 10; the side opposite to the front end of the connector on which the ferrule 20 tip is disposed). And a sleeve-like stop ring main body 481 extending to the rear end of the stop ring main body 481 opposite to the front end 481a fitted and fixed to the rear end of the plug frame 41. And a rear ring 482.

The front end portion 481a of the stop ring body 481 is formed with an extension hole portion 481b and a spring receiving surface 481c similar to the stop ring portion 42 of the rear unit 43 of the optical connector 10 of the first embodiment. The spring 30 is interposed between the flange portion 22c of the ferrule 20 and the spring receiving surface 481c and is housed in the housing 40C.
The stop ring main body 481 is engaged with a rear end portion of the plug frame 41 by engaging a locking projection 481f provided on the outer periphery of the front end portion 481a, so that the rearward movement and extraction from the plug frame 41 are restricted. Yes. The rear ring 482 is restricted from moving rearward from the stop ring main body 481 and being pulled out by engagement with a rear locking projection 481g protruding from the outer periphery of the rear end of the stop ring main body 481.

  Further, the ferrule 20 of the optical connector 10C has its flange portion 22c disposed between the end surface 481d of the front end portion 481a of the stop ring main body 481 and the front side stopper projection 46 of the plug frame 41, so as to form a sleeve shape as a whole. It is housed in a housing 40C formed in the above. A clearance C3 is provided between the end surface 481d of the front end portion 481a of the stop ring body 481 and the front stopper protrusion 46 of the plug frame 41 to enable the flange portion 22c of the ferrule 20 to move in the connector longitudinal direction. The movable amount of the flange portion 22c by the clearance C3 is the movable amount of the ferrule 20 in the longitudinal direction of the connector.

The ferrule 20 is elastically biased toward the connector front side by the elastic biasing force of the spring 30, and the flange portion 22 c is in contact with the front stopper protrusion 46 of the plug frame 41 from the connector rear side. The position where the flange portion 22c contacts the front stopper protrusion 46 of the plug frame 41 (the position shown in FIG. 10) is the movement limit position of the ferrule 20 to the connector front side. Hereinafter, the position of the ferrule 20 at this time is also referred to as an initial position.
Further, in the ferrule 20, the position where the flange portion 22c abuts on the end surface 481d of the front end portion 481a of the stop ring body 481 from the front side of the connector by the pushing to the rear side of the connector is the push-down limit position to the rear side of the connector. .

  An optical fiber core wire 13 is inserted into the inside of the housing 40C from the rear end portion thereof, and the bare optical fiber 13a exposed by removing the coating material at the tip end portion of the optical fiber core wire 13 is formed on the ferrule 20. The ferrule body 21 is inserted into the fiber hole 21a so as to be movable in the direction of the central axis of the fiber hole 21a. Further, a boundary portion between the covering portion 13d and the bare optical fiber 13a which is a portion covered with the covering material of the optical fiber core wire 13 is disposed in the expansion hole portion 21e on the rear end side of the fiber hole 21a. ing. The distal end portion of the covering portion 13d inserted into the expansion hole portion 21e is also movable in the central axis direction of the fiber hole 21a.

  The optical fiber core 13 is passed through the stop ring 48 through the opening (rear end opening 482a) at the rear end of the stop ring 48, and the mechanical splice housed in the rear end of the stop ring 48 is provided. A portion extending from the portion gripped by 49 (gripping portion) (the gripped portion 13b) to the front side of the connector (tip-side extending portion 13c) is inserted from the ferrule rear hole 22d of the ferrule 20 into the fiber hole 21a of the ferrule body 21. Has been.

As shown in FIG. 11, the mechanical splice 49 has a split structure element 492 inside a clamp spring 491 formed of a metal plate in a sleeve shape having a C-shaped or U-shaped cross section (in the illustrated example, a U-shaped cross section). The optical fiber core wire 13 disposed between a pair of elongated elements 492 and 493 is held by being clamped by the elasticity of the clamp spring 491. As shown in FIG. 12A, a positioning groove 494 for positioning the optical fiber core wire 13 is formed in one of the opposing surfaces 492a and 493a of the pair of elements 492 and 493 facing each other in the longitudinal direction of the element 492. The mechanical splice 49 is formed in the middle of the optical fiber core 13 by gripping the optical fiber core wire 13 accommodated in the positioning groove 494 between a pair of elements 492 and 493. It is fixed to the part.
The positioning groove 494 is not limited to the V groove illustrated in FIG. 12A, and for example, a round groove (groove having a semicircular cross section), a U groove, or the like can be employed. Further, the positioning groove 494 may be formed not only on one opposing surface of the pair of elements but also on the opposing surfaces of both elements.

As shown in FIG. 10, the mechanical splice 49 includes a first stopper protrusion 481e that protrudes inside the rear end of the stop ring body 481 of the stop ring 48, and an inner side of the rear end of the rear ring 482. It is held between the second stopper protrusion 482b that protrudes and is arranged on the rear side of the connector with respect to the first stopper protrusion 481e, thereby restricting the movement of the housing 40C in the front-rear direction of the connector and housing 40C. It is stored inside.
As a result, the optical fiber core wire 13 is retained with respect to the housing 40 </ b> C so as not to be pulled out to the rear side of the housing 40 </ b> C via the mechanical splice 49 fixed to the optical fiber core wire 13.
The rear end portions of the housing 40C and the stop ring 48 of the optical connector 10C function as a retaining portion 63 (hereinafter also referred to as an optical fiber retaining portion) that retains the optical fiber core wire 13.

In the illustrated example, the second stopper protrusion 482b of the rear ring 482 protrudes over the entire inner periphery of the rear end of the sleeve-shaped rear ring body 482c of the rear ring 482, and the rear portion of the stop ring 48 is provided. The opening 482a is secured inside the second stopper protrusion 482b.
However, the second stopper protrusion 482b does not necessarily have a configuration protruding on the entire inner periphery of the rear end of the rear ring main body 482c, and the shape thereof is not limited to that of the illustrated example. No.

As shown in FIG. 12B, the mechanical splice 49 has a clamp spring 491 between a pair of elements 492 and 493 by a plate-like or sheet-like insertion member 495 inserted between the pair of elements 492 and 493. The optical fiber core wire 13 was passed between the pair of elements 492 and 493 so as to be along the positioning groove 494 in a state where it was slightly pushed open against the elasticity of the optical fiber (hereinafter referred to as an open state). Thereafter, the optical fiber core wire 13 is gripped between the pair of elements 492 and 493 by removing the insertion member 495 from between the pair of elements 492 and 493, thereby being fixed to the optical fiber core wire 13. The
An opening 491a in a cross section perpendicular to the longitudinal direction of the sleeve-like clamp spring 491 extends over the entire length in the longitudinal direction of the clamp spring 491 (hereinafter, the opening 491a is also referred to as a full-length opening). The elements 492 and 493 are clamped so that the seam is arranged at the center in the interval direction (the center in the width direction of the full length opening 491a) of both ends via the full length opening 491a of the clamp spring 491. It is held inside the spring 491.
The insertion member 495 has a base end portion opposite to a distal end portion interposed between the pair of elements 492 and 493 from a side surface exposed to the full length opening 491a of the clamp spring 491 of the pair of elements 492 and 493. It is provided so as to protrude. The insertion member 495 of the illustrated example has an extraction operation portion 495a at the base end portion, and the extraction operation portion 495a can be used for an extraction operation between the pair of elements 492 and 493. it can.

  As shown in FIG. 10, the optical connector 10 </ b> C has the tip of the ferrule 20 in the initial position from the portion (the gripped portion 13 b) gripped by the mechanical splice 49 of the optical fiber retaining portion 63 of the optical fiber core wire 13. When the distance L31 (L1) to the surface 21b and the ferrule 20 are in the pushing limit position (when the flange portion 22c contacts the front end portion 481a (specifically, the end surface 481d) of the stop ring 48 of the housing 40C) The distance L32 (L2) from the gripped portion 13b of the optical fiber core wire 13 to the ferrule tip end surface 21b and the extension length L33 of the distal end side extension portion 13c of the optical fiber core wire 13 from the gripped portion 13b. (L3) satisfies L32 <L33 <L31.

  In the optical connector 10C, the distance between the step portion of the fiber hole 21a and the tip of the covering portion 13d of the optical fiber core wire 13 (the distance when the ferrule 20 is in the initial position) is the ferrule 20. The difference between the distance L32 from the gripped portion 13b of the optical fiber core wire 13 to the ferrule tip surface 21b and the extension length L31 of the tip side extension portion 13c of the optical fiber core wire 13 when is at the push-in limit position ( L31-L33), even if the ferrule 20 is displaced in the longitudinal direction of the connector, the covering material of the covering portion 13d at the boundary portion between the covering portion 13d of the optical fiber core wire 13 and the bare optical fiber 13a The end face abuts against a step portion (specifically, a tapered hole portion 21g shown in FIG. 2) between the main hole portion 21f (see FIG. 2) of the fiber hole 21a and the expansion hole portion 21e. It is made as to no.

(Fourth embodiment)
As shown in FIG. 13, this optical connector 10 </ b> C uses a rear ring 482 for fixing a strength member 14 b (strength fiber) extended from the end of the optical fiber cord 14 to the end portion of the optical fiber cord 14. It is also possible to assemble. Reference numeral 10D in the figure is added to the optical connector (the optical connector of the fourth embodiment) assembled to the end portion of the optical fiber cord 14.
The optical fiber cord 14 illustrated in FIG. 13 has a configuration in which an optical fiber core wire 13 and a strength member 14b are accommodated in a protective tube 14a. The optical fiber cord 14 is sandwiched between the rear ring 482 and the caulking ring 483 that is externally fitted to the rear ring 482 by fixing the strength member 14b extending from the distal end of the protective tube 14a, thereby fixing the housing 40C. It is retained at the rear end. In the figure, reference numeral 484 denotes a boot.

(Fifth embodiment)
FIG. 14 shows a fifth embodiment of the optical connector according to the present invention.
This optical connector 10E uses a coated optical fiber (optical fiber core wire 13 in the illustrated example) in place of the optical fiber cable 90 of the optical connector 10 of the first embodiment, and replaces the retaining member 60 with the covering member 50. Thus, a mechanical splice 49A that holds the middle portion of the optical fiber core 13 and is fixed to the optical fiber core 13 is housed. The configuration of the optical connector 10E is the same as that of the optical connector 10 of the first embodiment except that the optical fiber core wire 13 and the mechanical splice 49A are employed.

  The mechanical splice 49A is the one in which the size of the mechanical splice 49 described in the third embodiment is changed and the movement of the connector in the longitudinal direction of the connector (in the direction of the central axis of the housing 40) is restricted and stored in the retaining portion 60. . The mechanical splice 49A holds a split structure element 492 ′, 493 ′ inside a clamp spring 491 ′ formed in a sleeve shape having a C-shaped or U-shaped cross section (in the illustrated example, a U-shaped cross section) by a metal plate. The optical fiber core wire 13 having a structure and disposed between a pair of elongated elements 492 ′ and 493 ′ is held by being sandwiched by the elasticity of the clamp spring 491 ′. The optical fiber core 13 is accommodated between a pair of elements 492 ′ and 493 ′ in a state where the optical fiber 13 is housed and positioned in a positioning groove 494 ′ formed in one of the pair of elements 492 ′ and 493 ′ extending in the front-rear direction of the connector. It is gripped and fixed.

In the fiber hole 21a of the ferrule main body 21 of the ferrule 20, the bare optical fiber 13a exposed by removing the coating of the tip end portion of the optical fiber core wire 13 is inserted so as to be movable in the central axis direction of the fiber hole 21a. Yes.
A boundary portion between the bare optical fiber 13a and the covering portion 13d of the optical fiber core wire 13 is disposed in the expansion hole portion 21e of the fiber hole 21a, and is movable in the central axis direction of the fiber hole 21a. The bare optical fiber of the optical fiber core 13 with respect to the step portion (specifically, the tapered hole portion 21g shown in FIG. 2) between the main hole portion 21f (see FIG. 2) and the expansion hole portion 21e of the fiber hole 21a. The positional relationship of the boundary portion between 13a and the covering portion 13d is the positional relationship of the boundary portion between the bare optical fiber 91a and the covering portion 91b of the optical fiber 91 in the optical connector 10 of the first embodiment with respect to the step portion of the fiber hole 21a. The resin coating material end face of the covering portion 13d of the optical fiber core wire 13 does not hit the step portion of the fiber hole 21a even if the ferrule 20 is displaced in the longitudinal direction of the connector.

  The optical connector 10E has the optical fiber holding portion 60 of the optical fiber core wire 13 when the ferrule 20 is not pushed and displaced (when the flange portion 22c is in contact with the front stopper projection 46). The distance L51 (L1) from the portion gripped by the mechanical splice 49A (the gripped portion 13e) to the ferrule tip surface 21b and when the ferrule 20 is in the pushing limit position (the flange portion 22c is the front end portion of the stop ring portion 42) The distance L52 (L2) from the gripped portion 13e of the optical fiber core wire 13 to the ferrule tip surface 21b (when abutted against 42c), and the gripped portion 13e of the optical fiber core wire 13 extending to the front side of the connector. The gripping portion of the tip side extension 13f (including the bare optical fiber 13a exposed at the tip) that is a portion to be Extending length L53 from parts 13e (L3) and has a structure that satisfies L52 <L53 <L51.

In addition, this invention is not limited to the above-mentioned embodiment, It can change suitably.
For example, the optical connector 10C of the third embodiment and the optical connector 10D illustrated in FIG. 13 are socket-plug coupling type optical connectors, but the present invention uses the plug frame of the optical connectors 10C, 10D as the second. An optical connector changed to the plug frame 41A exemplified in the optical connector 10B of the embodiment, and a plug-adapter-plug coupling type optical connector coupling structure using the optical connector can also be adopted.
It goes without saying that the optical connector 10C of the third embodiment and the optical connector 10D illustrated in FIG. 13 can be changed to an assembled configuration using an optical fiber instead of the optical fiber core. .
The retaining portion of the optical connector according to the present invention may be any configuration that can retain the coated optical fiber such as the end portion of the optical fiber cable 90 or an optical fiber core wire or an optical fiber strand, and is exemplified in the above embodiment. The configuration is not limited.
The ferrule is not limited to the one in which the flange member 22 having the extended sleeve portion 22b is fixed to the ferrule main body 21 as described above, and the flange member not having the extended sleeve portion 22b is fixed to the ferrule main body 21. It is also possible to adopt. Further, it is possible to employ a ferrule having a configuration in which the ferrule main body itself is a single component having a flange portion protruding therefrom.

DESCRIPTION OF SYMBOLS 10, 10B, 10C, 10D, 10E ... Optical connector, 11 ... Optical connector adapter, 12 ... 2nd optical connector (optical connector), 12a ... Optical fiber (coated fiber), 12a1 ... Optical fiber (bare optical fiber), 12b ... housing, 12c ... ferrule, 12d ... spring, 12e ... (ferrule) tip surface, 13 ... optical fiber (fiber optic core), 13a ... optical fiber (bare optical fiber), 13b ... held portion, 13c ... tip Side extension part, 13e ... gripped part, 13f ... tip side extension part,
20 ... Ferrule, 21 ... Ferrule body, 21a ... Fiber hole, 21b ... Tip surface (of ferrule), 22c ... Flange, 30 ... Spring, 40, 40 ', 40C ... Housing, 42c ... Rear stopper projection (stop) Front end of ring part), 46 ... front stopper projection, 481a ... rear stopper projection (front end of stop ring body), 49, 49A ... gripping part (mechanical splice), 50 ... gripping tool (outer gripping member) ), 60... Retention portion (cable retention portion), 63... Retention portion (optical fiber retention portion),
80 ... second optical connector (optical connector), 81 ... ferrule, 81a ... (tip surface), 82 ... optical fiber (coated optical fiber), 82a ... optical fiber (bare optical fiber), 83 ... housing, 85 ... spring.

Claims (9)

The rear of the ferrule (20) and the sleeve-like housing (40, 40 ', 10C) that accommodates the spring (30) for elastic biasing of the ferrule opposite to the front end where the ferrule tip is disposed At the end, a holding portion (60, 63) for holding the terminal portion of the optical fiber cable (90) or the optical fiber (13) while restricting displacement in the central axis direction of the housing is provided.
The holding portion has a gripping portion (50, 49, 49A) for gripping the optical fiber cable end portion or the optical fiber, and extends from a tip side extending from a portion gripped by the gripping portion of the optical fiber. The tip end of the portion (13c, 13e) or the tip end of the optical fiber (91) extending from the end portion of the optical fiber cable extends to the fiber hole (21a) formed in the ferrule in the extending direction of the fiber hole. Interpolated movably,
The optical fiber gripped by the gripping part or the gripped part (13b, 13d), which is the part gripped by the gripping part of the optical fiber cable, is not applied to the rear side of the housing. A distance L1 to the tip surface (21b) of the ferrule, a distance L2 from the gripped portion to the ferrule tip surface when the ferrule is at the push-down limit position to the rear side of the housing, and an extension from the gripped portion An optical connector (10, 10B to 10E), wherein an extension length L3 of the optical fiber satisfies L2 <L3 <L1.   The optical fiber cable has a structure in which an optical fiber (91) is embedded in a resin coating material (93) together with a linear strength member (92) vertically attached to the optical fiber, and the grip portion is the light An outer gripping member (50) for gripping and fixing the optical fiber cable terminal portion to a fiber cable terminal portion, and the housing holding member with the retaining portion fixed to the optical fiber cable terminal portion. The optical connector according to claim 1, wherein the optical connector is a cable retaining portion (60) that retains the optical fiber cable terminal portion to the housing by restricting and retaining the displacement in the central axis direction.   The optical fiber gripped by the gripping portion is an optical fiber core wire (13) or an optical fiber strand, and the bare optical fiber (13a) exposed at the tip of the optical fiber is inserted into the fiber hole of the ferrule. The optical connector according to claim 1, wherein the optical connector is provided.   A distance L1 from the gripped portion to the ferrule tip surface when the ferrule is not pushed toward the rear end of the housing, and the gripped when the ferrule is at the push limit position The optical connector according to any one of claims 1 to 3, wherein a difference from a distance L2 from the portion to the ferrule tip surface is less than 1 mm.   A rear stopper protrusion (42c, which regulates movement of the ferrule to the rear side of the housing by abutting a flange portion of the ferrule pushed toward the rear end side of the housing inside the housing. 481a) is protruded, and the position where the flange portion (22c) protruding from the ferrule abuts against the rear stopper protrusion is the push-in limit position of the ferrule. The optical connector according to claim 1.   The housing has a front stopper protrusion (46) for restricting the ferrule from coming out of the front side of the housing by abutting the flange portion of the ferrule on the inner side, and the rear end portion of the housing on the ferrule. The distance L1 from the gripped portion to the ferrule tip surface when no inward displacement is given is the same as the distance when the flange portion of the ferrule is in contact with the front stopper projection of the housing. The optical connector according to claim 1, wherein the optical connector is a distance from a grip portion to the ferrule tip surface. An optical connector coupling structure of a socket-plug coupling system or a plug-adapter-plug coupling system,
A first optical connector which is the optical connector according to any one of claims 1 to 5, a ferrule (12c, 81) and an elastic biasing spring (12d, 85) of the ferrule in the housing (12b, 83) A second optical connector (12) which is an optical connector having a configuration in which the tip of the optical fiber (12a, 12a1, 82, 82a) housed and fixed to the ferrule is positioned on the tip surface (12e, 81a) of the ferrule. , 80) are connected to each other by fitting the first optical connector and the second optical connector or inserting and fitting them into the optical connector adapter (11) so that the ferrules are brought into contact with each other. The optical fiber inserted into the optical fiber and the optical fiber inserted and fixed to the ferrule of the second optical connector are abutted against each other, and the first Optical connector coupling structure, characterized in that bending the optical fiber extending between the gripped portion of the connector and the ferrule body of the ferrule is formed.   8. The optical connector coupling structure according to claim 7, wherein the ferrule of the first optical connector is disposed at a pushing limit position.   As the second optical connector, when the ferrule is detached from the optical connector adapter, a movable amount by pushing the ferrule toward the rear end side opposite to the front end portion where the ferrule is disposed is the first optical connector. When the ferrule of one optical connector is not pushed to the rear end side of the housing, the distance L1 from the gripped portion to the ferrule tip surface, and when the ferrule is at the push-in limit position 9. The optical connector coupling structure according to claim 7, wherein a larger one than a difference from a distance L <b> 2 from the gripped portion to the ferrule tip end surface is used.

Images