JP2005114863A - Ferrule for optical connector and method of assembling optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ferrule for an optical connector that can be miniaturized and an optical connector assembling method using such a ferrule.
An optical connector ferrule 1 is provided with a connection point of an optical fiber core wire 7 therein, and a mechanical splice portion M is mounted on the ferrule 1 itself, so that the ferrule 1 can be miniaturized. . Since the ferrule 1 has a configuration in which a resin elastic band 12 is fixed to the outer peripheral surfaces of the ferrule main body 2 and the pressing member 10, the ferrule main body 2 and the pressing member 10 are formed by the resin elastic band 12. Integrated, there is no hassle of assembling the mechanical splice part M on site. The wedge member 14 inserted into the wedge hole 16 from the wedge port 17 of the elastic band 12 expands the split portion S between the ferrule body 2 and the pressing member 10 and facilitates mounting of the optical fiber core 20a on the optical cable side. To do.
[Selection] Figure 1

Description

  The present invention relates to a ferrule used inside an optical connector that enables optical connection between optical cables and an optical transceiver, and a method of assembling an optical connector in which the ferrule is incorporated in a housing.

  As optical connectors that have been generally employed, there are JP-A-10-170756 and JP-A-11-160563. The optical connector described in this publication is called a so-called “mechanical splice”, and it is considered that the assembly can be completed easily and in a short time at an installation site or the like. In such a field assembly type optical connector, a mechanical splice portion is connected to the rear end of the cylindrical ferrule, and the mechanical splice portion includes a base member provided with an optical fiber insertion groove having a V-shaped cross section, The cover member is pressed against the base member so as to close the optical fiber insertion groove, and the spring-like clamp member sandwiches the base member and the cover member.

  When assembling such an optical connector in the field, first, the wedge member is inserted into the mechanical splice part, the divided part of the base member and the cover member is expanded, and the optical fiber insertion groove is opened. Thereafter, the optical fiber core of the optical cable is inserted from the rear end side of the optical fiber insertion groove, and the tip of the optical fiber core is abutted against the rear end of the optical fiber core in the ferrule. Then, by pulling out the wedge member, each optical fiber core wire is sandwiched between the base member and the cover member, and the optical fiber core wire on the ferrule side and the optical fiber core wire on the optical cable side are coupled at the mechanical splice portion. Thereafter, a plastic housing is mounted so as to cover the ferrule and the mechanical splice, and the assembly of the optical connector is completed.

JP-A-10-170756 JP-A-11-160563 JP 2001-208937 A JP 2000-121863 A JP 09-127371 A JP 11-337760 A

  When such a mechanical splice type optical connector is used in an indoor optical outlet or a rosette, the total length of the optical connector may be regulated by standards or the like. However, since the conventional optical connector has a mechanical splice portion behind the ferrule, the total length of the optical connector becomes long, so that there is a problem that it is difficult to use indoors with many dimensional restrictions. .

  An object of the present invention is to provide a ferrule for an optical connector that can be miniaturized by reducing the number of parts, and an optical connector assembling method using such a ferrule.

  In this optical connector ferrule, in the optical connector ferrule in which the optical fiber core wire is incorporated, the optical fiber ferrule has a first optical fiber insertion groove extending rearward from the rear end of the optical fiber core wire, A ferrule body having a notch provided at the position of the first optical fiber insertion groove, a pressing member loaded in the notch so as to cover the first optical fiber insertion groove, and a pressing member on the ferrule body Inserting the first optical fiber along the resin elastic band fixed to the outer peripheral surface of the ferrule main body and the pressing member and the divided portion formed between the ferrule main body and the pressing member in the mounted state It is characterized by comprising a wedge insertion portion comprising a wedge hole extending in a direction orthogonal to the groove and a wedge opening formed in an elastic band so as to communicate with the wedge hole. That.

  In the ferrule for an optical connector according to the present invention, the connection point of the optical fiber core wire is provided therein, and the mechanical splice portion is mounted on the ferrule itself, so that the ferrule can be miniaturized. Since this ferrule has a structure in which a resin elastic band is fixed to the outer peripheral surfaces of the ferrule main body and the pressing member, the ferrule main body and the pressing member may be integrated by a resin elastic band. This eliminates the hassle of assembling the mechanical splice part on site. Further, the wedge member inserted into the wedge hole from the wedge opening of the elastic band expands the divided portion of the ferrule body and the pressing member, facilitating mounting of the optical fiber core on the optical cable side. Moreover, since the elastic band is made of resin, it is easy to make transparent, and when a transparent resin or transparent glass is used for the pressing member, the mechanical splice portion can be made transparent. As a member for pressing the pressing member against the ferrule body, a spring steel ring is generally used. However, the ring of spring steel is not only difficult to be transparent, but is also easily plastically deformed, the shape is enlarged, the dimensions are likely to vary, and the desired strength is not easily obtained.

  In addition, it is preferable that a wedge member inserted into the wedge hole is further provided. At the factory shipment stage, if the wedge parts are preloaded in the wedge holes, the optical fiber core fiber on the optical cable side and the optical fiber core wire on the ferrule side can be simply pulled out when the optical connector is assembled. Can be combined easily and speedily, and the assembly workability in the field is improved.

  Further, a refractive index matching agent injection hole extending from the outside to the first optical fiber insertion groove and extending toward the rear end of the optical fiber core wire in a direction orthogonal to the first optical fiber insertion groove. It is preferable to further provide. Such a configuration allows the refractive index matching agent to be injected into the interior of the ferrule, thus allowing the optical cable to be reconnected.

  The elastic band and the pressing member are preferably formed of a transparent material. By adopting such a configuration, the rear end of the optical fiber core located directly below the pressing member can be visually confirmed, so the connection status between the optical fiber core on the optical cable side and the optical fiber core wire on the ferrule side can be confirmed. However, the assembling work can be advanced, and the workability is further improved.

  The elastic band is preferably a polysulfone resin. Since this resin is transparent and hardly plastically deformed, it is a material suitable for an elastic band.

  Further, it is preferable that the holding member is formed with a second optical fiber insertion groove having a V-shaped cross section extending so as to face the first optical fiber insertion groove. By adopting the second optical fiber insertion groove having a V-shaped cross section, the optical fiber core on the optical cable side can be reliably held in the ferrule.

  An optical connector assembling method is a method of assembling an optical connector in which the ferrule according to claim 1 is incorporated in a housing, the step of removing the outer sheath at the tip of the optical cable to expose the optical fiber core, and the ferrule Insert the optical fiber core wire from the rear end of the ferrule along the first optical fiber insertion groove provided in the main body, and attach the optical fiber core wire to the rear end of the optical fiber core wire built in the ferrule in advance. And a step of abutting and a step of removing a wedge member preloaded in the wedge hole. This method is used for the initial assembly of the optical connector.

  An optical connector assembling method is a method of assembling an optical connector in which the ferrule according to claim 1 is incorporated in a housing, wherein a wedge member is loaded into a wedge hole provided in the ferrule to expand a divided portion. The step of extracting the optical fiber core of the optical cable from the rear end of the ferrule, and injecting the refractive index matching agent from the refractive index matching agent injection hole provided in the ferrule, A step of attaching a refractive index matching agent to the rear end of the optical fiber, a step of cutting the front end of the optical fiber core of the optical cable, and light from the rear end of the ferrule along the first optical fiber insertion groove provided in the ferrule body. Inserting the fiber core and bringing the optical fiber core into contact with the rear end of the optical fiber previously built in the ferrule and loading it into the wedge hole It is characterized by comprising the step of overtake the wedge members are. This method is used for reassembling the optical connector.

  The ferrule according to the present invention enables miniaturization. According to the optical connector assembling method of the present invention, the housing can be miniaturized as the ferrule is miniaturized, and the optical fiber core on the optical cable side can be attached to the miniaturized optical connector.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an optical connector ferrule and an optical connector assembling method according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, an optical connector ferrule 1 is used for a single core and has a cylindrical ferrule body 2 made of zirconia ceramic and having a diameter of about 2.5 mm. At the rear of the ferrule body 2, a notch 4 is formed in a semicylindrical shape. A ring-shaped flange portion 5 is fixed to the outer peripheral surface of the ferrule body 2 by press-fitting.

  Further, an optical fiber loading hole 6 extending inward from the front end surface 2a is formed at the center of the ferrule body 2, and the optical fiber core wire 7 is interposed in the optical fiber loading hole 6 with an adhesive. Is fixed. In addition, a first optical fiber having a semicircular cross section arranged in a straight line with respect to the optical fiber loading hole 6 is inserted into the first dividing surface 2b formed in the rear portion of the ferrule body 2 by the notch 4. A groove 8 is formed. Then, the rear end of the optical fiber core wire 7 is inserted into the first optical fiber insertion groove 8, whereby the first optical fiber insertion groove 8 extends rearward from the rear end of the optical fiber core wire 7. Will be extended. In addition, the excess part of the optical fiber core wire 7 which protruded from the front end surface 2a of the ferrule main body 2 is removed when the front end surface 2a is polished.

  Further, the ferrule 1 has a semi-cylindrical pressing member 10 that is loaded into the notch 4 so as to cover the first optical fiber insertion groove 8. A second optical fiber insertion groove 11 having a V-shaped cross section is formed on the second dividing surface 10a of the pressing member 10 so as to face the first optical fiber insertion groove 8, and the second optical fiber insertion is performed. By forming the groove 11 in a V-shaped cross section, positioning and holding of an optical fiber core wire 20a described later can be reliably achieved. Then, when the pressing member 10 is loaded into the cutout portion 4 of the ferrule body 2, the divided portion S is cooperated by the first dividing surface 2b on the ferrule body 2 side and the second dividing surface 10a on the pressing member 10 side. The optical fiber insertion path 13 is formed in cooperation with the first optical fiber insertion groove 8 having a semicircular cross section and the second optical fiber insertion groove 11 having a V-shaped cross section.

  Further, the ferrule 1 has an elastic band 12 made of resin that presses the pressing member 10 against the ferrule body 2, and the elastic band 12 includes a first optical fiber insertion groove 8 and a second optical fiber insertion groove 11. Are pressed against the outer peripheral surfaces of the ferrule body 2 and the pressing member 10 so as to be maintained in a state of being opposed to each other. The elastic band 12 employs a resin (for example, polysulfone resin, polyethersulfone resin, polyphenylsulfone resin, etc.) for achieving both transparency and difficulty in plastic deformation, and the displacement of the pressing member 10 in the radial direction. Is possible.

  A flat wedge member 14 is used as a member that enables displacement of the pressing member 10. In order to load the wedge member 14 into the ferrule 1, the pressing member 10 includes a ferrule body 2 and a pressing member 10. A wedge hole 16 extending in a direction orthogonal to the first and second optical fiber insertion grooves 8 and 11, that is, in the radial direction is provided along the divided portion S formed therebetween. Correspondingly, a rectangular wedge port 17 communicating with the wedge hole 16 is formed in the elastic band 12, and a wedge insertion portion 18 is formed by the cooperation of the wedge hole 16 and the wedge port 17.

  In this way, the pressing member 10, the elastic band 12, the wedge member 14, and the wedge insertion portion 18 constitute a mechanical splice portion M, and the optical fiber core 7 and the optical fiber core on the optical cable 20 side are provided inside the ferrule 1. Since the connection point with the wire 20a is provided and the mechanical splice portion M is mounted on the ferrule 1 itself, the ferrule 1 can be downsized. As a member for pressing the pressing member 10 against the ferrule body 2, a spring steel ring is generally used. However, the ring of spring steel is not only difficult to be transparent, but is also easily plastically deformed, the shape is enlarged, the dimensions are likely to vary, and the desired strength is not easily obtained.

  Furthermore, a funnel-shaped guide portion 19 is formed at the rear end of the optical fiber insertion path 13, so that the optical fiber core wire 20 a of the optical cable 20 (see FIG. 3) can be easily guided to the optical fiber insertion path 13 during assembly work. . A boot portion 21 made of rubber or elastic resin is attached to the rear end of the ferrule 1 in order to appropriately restrict the bending of the optical cable 20.

  Further, in consideration of reconnection of the optical cable 20 (see FIG. 3) due to failure in assembly work or the like, the ferrule 1 is provided with a refractive index matching agent injection hole 22 that enables the refractive index matching agent P to be injected. Yes. The refractive index matching agent injection hole 22 extends toward the rear end of the optical fiber core wire 7 in a direction orthogonal to the first and second optical fiber insertion grooves 8 and 11 at the position of the divided portion S. In addition, the first and second optical fiber insertion grooves 8 and 11 are penetrated from the outside.

  Next, a procedure for attaching the optical fiber core wire 20a of the optical cable 20 to the ferrule 1 described above will be described. In the factory shipment stage, the ferrule body 2 and the pressing member 10 are integrated by a resin elastic band 12.

  As shown in FIG. 4, at the work site, first, the wedge member 14 is inserted into the wedge hole 16 of the ferrule 1 to expand the divided portion S. In order to improve the assembly workability, the wedge member 14 may be preloaded in the wedge hole 16 at the factory shipment stage. Thereafter, the outer sheath at the tip of the optical cable 20 is removed using a so-called remover (not shown) for removing the outer sheath, and the optical fiber core wire 20a having a predetermined length is exposed. Thereafter, the optical fiber core 20a of the optical cable 20 is inserted from the rear end of the ferrule 1 along the first and second optical fiber insertion grooves 8 and 11 provided in the ferrule body 2, and is built in the ferrule body 2 in advance. The optical fiber core wire 20a on the optical cable 20 side is brought into contact with the rear end of the optical fiber core wire 7 (see FIG. 3).

  At this time, since the refractive index matching agent P (see FIG. 2) is attached in advance to the rear end of the optical fiber core wire 7 in the ferrule 1 at the time of factory shipment, Thus, the optical fiber core 7 on the ferrule 1 side and the optical fiber core 20a on the optical cable 20 side are appropriately optically connected in the ferrule 1. Further, when a transparent elastic resin is used for the elastic band 12 and a transparent resin or glass is used for the pressing member 10, the rear end of the optical fiber core wire 7 positioned directly below the transparent pressing member 10 can be visually confirmed. Therefore, it is possible to proceed with assembling work while confirming the connection state between the optical fiber core 20a on the optical cable 20 side and the optical fiber core 7 on the ferrule 1 side, and the reliability at the time of assembly and the confirmation workability after the assembly. Is significantly improved.

  Then, after the confirmation of the optical connection is completed, the optical cable 20 is mechanically fixed to the ferrule 1 by removing the wedge member 16 preloaded in the wedge hole 16 from the ferrule 1 as shown in FIG. The

  The above description relates to the initial assembly. However, when the assembly work is performed again due to the failure of the assembly work, first, the wedge member 14 is loaded into the wedge hole 16 provided in the ferrule 1 and divided. The portion S is expanded again, and the optical fiber core wire 20 a of the optical cable 20 is extracted from the rear end of the ferrule 1. Thereafter, the refractive index matching agent P is injected from the refractive index matching agent injection hole 22 provided in the ferrule 1, and the refractive index matching agent P is applied to the rear end of the optical fiber core 7 built in the ferrule 1 in advance. Adhere.

  Thereafter, the outer sheath at the tip of the optical cable 20 is removed using a so-called remover (not shown) for removing the outer sheath, and the optical fiber core wire 20a is cut into a predetermined length. Thereafter, the optical fiber core 20a on the optical cable 20 side is inserted from the rear end of the ferrule 1 along the first optical fiber insertion groove 8 provided in the ferrule body 2, and the light built in the ferrule 1 in advance. The optical fiber core wire 20 a is brought into contact with the rear end of the fiber core wire 7. Then, the optical cable 20 is mechanically fixed to the ferrule 1 by removing the wedge member 16 loaded in the wedge hole 16.

  Next, an assembling method of the optical connector 30 as shown in FIG. 6 will be described.

  Prior to the above-described operation of fixing the optical fiber core 20a on the optical cable 20 side to the ferrule 1, the optical cable 20 is inserted into the resin outer housing 31, the metal spring 32, and the rubber boot portion 21. Keep it. That is, the outer housing 31, the spring 32, and the boot portion 21 are held on the optical cable 20 side. After such a preparation is made, the optical cable 20 is mechanically fixed to the ferrule 1 according to the above-described procedure. . Thereafter, the boot portion 21 is attached to the rear end of the ferrule 1, and the outer housing 31 and the spring 32 are moved to the position of the ferrule 1.

  Thereafter, the inner housing 33 is pushed in from the opening at the front end of the outer housing 31, and the locking claws 31a of the outer housing 31 are fitted into the locking holes 33a of the inner housing 33, whereby the assembly work of the optical connector 30 is completed. In order to improve the internal visibility, the housing H including the outer housing 31 and the inner housing 33 can be formed of a transparent resin.

  The present invention is not limited to the embodiment described above. For example, the present invention can be applied to a multi-fiber ferrule in which a plurality of optical fiber core wires 7 are arranged in parallel. In the ferrule 1 which concerns on this invention, it is not restricted to the case where both the 1st optical fiber insertion groove 8 and the 2nd optical fiber insertion groove 11 exist, Only the 1st optical fiber insertion groove 8 may be sufficient. In addition, when visual inspection during work is not necessary, the pressing member 10 may be formed of aluminum in consideration of workability and the like.

It is a perspective view which shows one Embodiment of the ferrule for optical connectors which concerns on this invention. It is a longitudinal cross-sectional view of the ferrule shown in FIG. It is sectional drawing which shows the state which attached the optical cable to the ferrule which concerns on this invention. It is sectional drawing which shows the state which expanded the division part with the wedge member. It is sectional drawing which shows the state which removed the wedge member from the ferrule. It is sectional drawing which shows the optical connector in which the ferrule which concerns on this invention was integrated.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ferrule for optical connectors, 2 ... Ferrule main body, 4 ... Notch part, 7 ... Optical fiber core wire of ferrule side, 8 ... 1st optical fiber insertion groove, 10 ... Holding member, 11 ... 2nd optical fiber Insertion groove, 12 ... elastic band, 14 ... wedge member, 16 ... wedge hole, 17 ... wedge opening, 18 ... wedge insert, 20 ... optical cable, 20a ... optical fiber core on the optical cable side, 22 ... refractive index matching agent Injection hole, 30 ... optical connector, H ... housing, S ... split part, P ... refractive index matching agent, M ... mechanical splice part.

Claims (8)

In the ferrule for optical connectors with built-in optical fiber core,
A ferrule body having a first optical fiber insertion groove extending rearward from a rear end of the optical fiber core wire and having a notch provided at a position of the first optical fiber insertion groove;
A pressing member loaded in the notch so as to cover the first optical fiber insertion groove;
In a state where the pressing member is placed on the ferrule main body, an elastic band made of resin fixed to the outer peripheral surface of the ferrule main body and the pressing member;
A wedge hole extending in a direction orthogonal to the first optical fiber insertion groove along a divided portion formed between the ferrule body and the pressing member, and communicated with the wedge hole. A ferrule for an optical connector, comprising: a wedge insertion portion including a wedge opening formed in the elastic band.   The optical connector ferrule according to claim 1, further comprising a wedge member inserted into the wedge hole.   Refractive index matching agent injection extending toward the rear end of the optical fiber core wire in a direction orthogonal to the first optical fiber insertion groove and penetrating from the outside to the first optical fiber insertion groove The optical connector ferrule according to claim 1, further comprising a hole.   The ferrule for an optical connector according to claim 1, wherein the elastic band and the pressing member are formed of a transparent material.   The ferrule for an optical connector according to claim 4, wherein the elastic band is a polysulfone resin.   6. The second optical fiber insertion groove having a V-shaped cross section extending so as to face the first optical fiber insertion groove is formed in the pressing member. The ferrule for optical connectors as described in any one of Claims. A method of assembling an optical connector in which the ferrule according to claim 1 is incorporated in a housing,
Removing the outer sheath of the tip of the optical cable to expose the optical fiber core; and
Inserting the optical fiber core wire from the rear end of the ferrule along the first optical fiber insertion groove provided in the ferrule body, and rear end of the optical fiber core wire built in the ferrule in advance Contacting the optical fiber core with
A method of assembling the optical connector, comprising: removing a wedge member preloaded in the wedge hole. A method of assembling an optical connector in which the ferrule according to claim 1 is incorporated in a housing,
Loading a wedge member into the wedge hole provided in the ferrule, expanding the divided portion, and extracting an optical fiber core of an optical cable from a rear end of the ferrule;
Injecting a refractive index matching agent from a refractive index matching agent injection hole provided in the ferrule, and attaching the refractive index matching agent to a rear end of an optical fiber core wire built in the ferrule;
Cutting the tip of the optical fiber core of the optical cable;
After inserting the optical fiber core wire from the rear end of the ferrule along the first optical fiber insertion groove provided in the ferrule body, the optical fiber core wire previously built in the ferrule is inserted. Contacting the optical fiber core wire with an end; and
And a step of removing the wedge member loaded in the wedge hole.

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