JP4891710B2 - Optical fiber core fixing structure and fixing method thereof - Google Patents

Description

  The present invention relates to an optical fiber core fixing structure for an optical fiber core having a quartz core, for example, and a fixing method thereof.

  Conventionally, as a method for fixing an optical fiber in a ferrule, for example, a method of applying an adhesive as shown in Patent Document 1 is often used, and this method requires a work process of applying an appropriate amount of the adhesive.

  Further, a means for mechanically fixing, for example, as in Patent Document 2 without using an adhesive is also known.

JP 2004-144921 A Japanese Utility Model Publication No. 4-96702

  However, in the method using an adhesive, since the adhesive must be applied in advance to the ferrule, the adhesive adheres to the end surface of the optical fiber core and the tip of the ferrule when the optical fiber core is inserted into the ferrule. Therefore, a polishing process for removing the adhered adhesive and molding the end face of the optical fiber core wire is required.

  Further, there is a problem that the number of parts is large even when an adhesive is not used.

  The objective of this invention is providing the optical fiber core wire fixing structure which can eliminate the above-mentioned subject, and can fix an optical fiber core wire to a ferrule simply, and its fixing method.

In order to achieve the above object, the technical feature of the optical fiber core fixing structure according to the present invention is that an optical fiber core having a coating layer formed on the outer periphery of the optical fiber strand is bonded to a synthetic resin ferrule and rubber. in fixing structure for fixing with a sleeve made of a synthetic resin cover, said ferrule first hole for inserting the end portion of the optical fiber which is exposed by peeling the coating layer from the optical fiber possess a part, and a second hole for inserting the optical fiber communicating with the first hole, the rubber sleeve, said ferrule has a hole for inserting the optical fiber said the second to insertion into the bore an elastically deformable tubular shape, the cover is attached to the rear of the ferrule, the rubber sleeve is pressed forward by the compression within the second hole, said of the optical fiber core wire Is to secure the optical fiber within the ferrule are contacted by the stepped portion of the fiber and the coating layer.

The technical feature of the optical fiber core fixing method according to the present invention includes a first step of inserting an elastically deformable cylindrical rubber sleeve into the coating layer of the optical fiber core wire from which the optical fiber strand is exposed, The optical fiber is inserted into a first hole of a synthetic resin ferrule and the rubber sleeve communicates with the first hole of the ferrule and has a second diameter larger than that of the first hole. A second step of pushing into the hole portion, and attaching and fixing the synthetic resin cover to the rear portion of the ferrule, thereby pressing the rubber sleeve forward and compressing it in the second hole portion, a third step of fixing the optical fiber in the ferrule are contacted by the stepped portion between said optical fiber of the optical fiber the coating layer was exposed to the front from the front end of said ferrule It lies in comprising a fourth step of cutting the optical fiber.

  According to the optical fiber core fixing structure and the fixing method thereof according to the present invention, the optical fiber core can be fixed to the ferrule without using an adhesive, and can be disassembled and reused.

The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 is a sectional view of a ferrule made of synthetic resin. A ferrule 11 has a tapered cylindrical shape, and a hole portion into which an optical fiber is inserted is provided at the center. The small-diameter hole portion 11a, the small-diameter hole portion 11b, the medium-diameter hole portion 11c, and the large-diameter hole portion 11d have different diameters. Further, a locking claw 11e is provided for locking the cover when a cover described later is attached to the upper and lower portions of the outside.
Since the ferrule 11 requires fine molding as compared with the cover 13, it is preferable to select a material. As a material applicable to the ferrule 11, poniphenylene sulfide (PPS) excellent in dimensional stability is suitable.

  FIG. 2 shows a cross-sectional view of a rubber sleeve 12 made of synthetic rubber provided around the optical fiber core. The rubber sleeve 12 has a cylindrical shape and is provided with a hole 12a through which the optical fiber core wire is inserted. This rubber sleeve 12 is elastically deformed, and there is no particular problem as long as it is a material that can be processed and molded with high accuracy. However, silicon rubber is preferable in terms of excellent workability, moldability, and heat resistance.

  FIG. 3 shows a cross-sectional view of the cover 13 attached to the ferrule 11. A hole 13a is formed through the optical fiber core in the axial direction of the central portion, and the middle diameter portion 13b and the large diameter portion 13c are formed at the center. A projecting portion provided in two stages is formed, the medium diameter portion 13b is fitted in the medium diameter hole portion 11c of the ferrule 11, the large diameter portion 13c is fitted in the large diameter hole portion 11d, and the medium diameter portion 13b is configured to press the rubber sleeve 12 forward. In addition, on the upper and lower portions of the hood portion 13d of the cover 13, a locking frame 13e having elasticity to lock the locking claw 11e of the ferrule 11 is provided. Further, projections 13f for operating or fixing the cover 13 are formed at three positions in the same direction on the outer periphery of the cover 13. For this cover 13, polybutylene terephthalate (PBT) resin is preferable in that it has a high thermal deformation temperature and is excellent in high rigidity, electrical characteristics, and mechanical characteristics.

  As shown in FIG. 4, the heat-resistant coating layer 14a at the tip of the optical fiber 14 is peeled to expose the optical fiber 14b, and the rubber sleeve 12 is mounted on the heat-resistant coating layer 14a. The optical fiber 14 is inserted into the hole of the ferrule 11 as shown in FIG. That is, for example, an optical fiber 14b having a diameter of 0.23 mm is inserted into the small-diameter hole portion 11a of the ferrule 11, the tip is protruded from the tip of the ferrule 11 to a sufficient length, and the rubber sleeve 12 is placed on the heat-resistant coating layer 14a. Is slid into the medium diameter hole 11c. At this time, the diameter of the optical fiber 14b is small as described above, and insertion is difficult, but the small-diameter hole portion 11b of the ferrule 11 serves as a guide hole.

  Here, as shown in FIG. 6, when the cover 13 is pushed in from the rear side of the ferrule 11, the rubber sleeve 12 is pushed in by the middle diameter portion 13b of the cover 13, and the inner diameter is reduced and the outer diameter is reduced in the middle diameter hole portion 11c. Expands. As a result, the rubber sleeve 12 is firmly fixed so that the optical fiber core wire 14 does not move in the longitudinal direction within the ferrule 11.

  At this time, as shown in FIG. 7 and FIG. 8, the locking frame 13e of the cover 13 climbs over the locking claw 11e of the ferrule 11 and locks, so that the positional relationship between the ferrule 11 and the cover 13 is determined and separated. It becomes impossible. The optical fiber 14b protruding from the tip of the ferrule 11 is cut flush with the tip of the ferrule 11 with a cutter or the like.

  As described above, in this embodiment, since the optical fiber core wire 14 is compressed and fixed by the rubber sleeve 12, no foreign matter adheres to the distal end portion of the ferrule 11 and the end surface of the optical fiber core wire 14, and the optical fiber core wire. No polishing step as the end face processing method 14 is required, and the end face processing can be performed by cutting with a dedicated fiber cutter.

  In the above-described embodiment, the rubber sleeve 12 is pushed by pushing the cover 13 forward. However, the cover 13 and the ferrule 11 may be provided with a screw mechanism by pushing the cover 13 using a jig. The rubber sleeve 12 may be pushed in by screwing.

It is sectional drawing of a ferrule. It is sectional drawing of a rubber sleeve. It is sectional drawing of a cover. It is sectional drawing of the state which attached the rubber sleeve to the optical fiber core wire. It is sectional drawing of the state which inserted the optical fiber core wire in the ferrule. It is sectional drawing of the state which attached the cover to the ferrule. It is a top view. It is a front view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Ferrule 11a Small diameter hole part 11b Small diameter hole part 11c Medium diameter hole part 11d Large diameter hole part 11e Locking claw 12 Rubber sleeve 12a Hole part 13 Cover 13a Hole part 13b Medium diameter part 13c Large diameter part 13e Locking frame 14 Light Optical fiber 14a Heat-resistant coating layer 14b Optical fiber

Claims (4)

In a fixing structure for fixing an optical fiber core wire having a coating layer formed on an outer periphery of an optical fiber strand to a synthetic resin ferrule using a rubber sleeve and a synthetic resin cover , the ferrule includes the optical fiber A first hole passing through the end of the optical fiber exposed by peeling the coating layer from the core, and a second through the optical fiber in communication with the first hole. possess a hole, the rubber sleeve, and the optical fiber to have a hole for inserting to inserted into the second hole portion of the ferrule elastically deformable tubular shape, said cover, Attaching to the rear part of the ferrule, pressing the rubber sleeve forward to compress it in the second hole, and closely contacting the step part of the optical fiber and the coating layer of the optical fiber core wire By the optical fiber core Optical fiber fixing structure, characterized in that secured within the ferrule to. 2. The optical fiber core fixing structure according to claim 1, further comprising a mechanism for locking the ferrule after the cover is attached thereto. A first step of inserting an elastically deformable cylindrical rubber sleeve into the coating layer of the optical fiber core wire exposing the optical fiber strand; and the optical fiber strand in the first hole of the synthetic resin ferrule A second step of inserting the rubber sleeve into the second hole having a diameter larger than the first hole, communicating with the first hole of the ferrule, and a synthetic resin at the rear of the ferrule . The rubber sleeve is pressed forward and compressed in the second hole by attaching and fixing the cover, and a step portion between the optical fiber strand of the optical fiber and the coating layer Patent in that it consists of a fourth step of cutting a third step of fixing the optical fiber in the ferrule, the optical fiber exposed to the front from the tip of the ferrule are contacted by the Optical fiber fixing method according to. The optical fiber core wire fixing method according to claim 3 , wherein the ferrule and the cover are locked in the third step.

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