JP2005316221A - Mechanical splicing type optical connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanical splicing type optical connector with which an optical cable outer cover holding member is always fixed at the backward side of an optical connector housing, and thereby the optical cable outer cover holding member does not move ahead of the connector and does not increase splicing loss. <P>SOLUTION: The mechanical splicing type optical connector comprises an optical fiber ferrule having in the front half part a minute hole with a built-in optical fiber embedded and having in the rear half part an optical fiber holding part for holding the optical fiber in an optical cable to be connected, and the optical cable outer cover holding member for holding the outer cover of the optical cable, arranged in the optical connector housing, and the optical cable outer cover holding member is pressurized to the backward side of the optical connector housing by a backward pressurizing member arranged in the optical connector. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mechanical connection type optical connector.

Mechanical connection type optical connectors have been proposed as optical connectors excellent in workability and cost at the connection site of optical fibers (for example, Patent Documents 1 to 4).
As shown in FIG. 9, this type of mechanical connection type optical connector has a fine hole 13 in which a built-in optical fiber 12 is embedded in a front half portion 11, and an optical fiber 21 of an optical cable 20 to be connected to the latter half portion 14. 10 and 11, a ferrule substrate 10 having an optical fiber holding base 16 provided with a groove 15 for mounting the optical fiber, a cover 30 covering the optical fiber 21 on the optical fiber holding base 16, and as shown in FIGS. An optical fiber ferrule comprising a C-shaped fastening tool 40 for fixing the optical fiber 21 in the groove with the optical fiber holding base 16 and the lid 30 sandwiched therebetween is used. The lid 30 and the fastening tool 40 constitute an optical fiber gripping part 45.

  Such an optical connector is different from a conventional optical connector assembled in advance in a factory or the like, and can easily configure an optical connector at a connection site. That is, the built-in optical fiber 12 is disposed in advance in the optical connector, and its end surface 12 'is mirror-polished in advance. Further, the arrangement is pre-assembled in a factory or the like so that the axes of the optical fibers coincide with each other when the optical connectors are connected. For this reason, at the connection site, it is possible to simply provide an optical connector with low connection loss simply by mechanically connecting the optical fiber 21 to be connected to the built-in optical fiber 12 (mechanical splice).

  In addition, an optical fiber is built in an optical connector having the same interface as an SC (Square-shaped Snap-on Plastic Connector) connector, and the built-in optical fiber and the optical fiber terminated in the field are mechanically spliced. By doing so, an optical connector that can easily assemble an interface equivalent to an SC connector or the like on-site has also been developed.

The mechanical connection type optical connector is an optical connection method having excellent workability in the field as described above, but its disadvantage is that it is weak against pulling of the optical fiber 21. This is because the optical fiber 21 to be connected does not have a function of pressing in the connecting direction due to the mechanical splice mechanism, so that the end face 21 ′ of the optical fiber 21 receives the pulling force behind the connection beyond the fixing force. This is because the optical fiber end face 21 ′ cannot return to the position of the end face 12 ″ of the built-in optical fiber 12 again when it has retracted from the connection position.
For this reason, in general, when the optical fiber 21 fixed by the mechanical splice method is pulled with a force of about 1 kgf, the connection loss is often greatly deteriorated.

Japanese Patent Laid-Open No. 10-123366 JP-A-10-170756 JP-A-10-206688 JP-A-11-142686

  Therefore, it is necessary to assume that an optical connector for an optical cable is pulled by about 1 kgf to several kgf for handling. However, since this value is a value that greatly exceeds the allowable tensile strength of a general mechanical splice connection, for example, the spring 40 of the fastener 40 that sandwiches the optical fiber 21 between the optical fiber holder 16 and the lid 30 of the ferrule substrate 10 is applied. Methods such as increasing the pressure or increasing the length of the optical fiber holding base 16 and the lid 30 to increase the area for holding the optical fiber 21 can be considered. However, there are disadvantages in assembling workability and connector dimensions of the optical connector. Yes, it is difficult to respond.

  Therefore, as shown in FIG. 6, the outer sheath 20 ′ of the optical cable 20 is firmly fixed by an optical cable outer sheath gripping member 50, which is a separate member from the ferrule substrate 10, and the optical cable outer sheath gripping member 50 is fixed to the ferrule substrate 10 or the connector housing 60. The optical fiber 21 is housed in the optical cable skin gripping member installation space 61, and the optical fiber 21 has a slight extra length (slack) between the lid 30 and the optical cable skin gripping member 50.

  With this configuration, even when the optical cable is pulled, the optical cable sheath holding member is mechanically abutted and fixed at the rear in the installation space of the connector (housing), and a slight extra length remains in the optical fiber. No tensile force is applied to the optical fiber at the mechanical splice portion, and the tensile durability as an optical connector depends on the mechanical strength of the members constituting the connector, and increases dramatically.

However, in this configuration, the following problems occur depending on the size of the optical cable outer sheath holding member installation space 61.
That is, when the size of the gap is too wide as shown in FIG. 7 (a), when the optical cable skin gripping member 50 moves forward in the optical cable skin gripping member installation space 61, it is shown in FIG. 7 (b). As described above, since the slack given to the optical fiber 21 between the optical cable sheath holding member 50 and the lid 30 increases, the bending loss of the optical fiber 21 cannot be ignored and the connection loss as an optical connector is deteriorated. Is concerned.

  On the contrary, as shown in FIGS. 8A and 8B, when the size of the gap is small, the handling property (workability) when the optical cable skin gripping member 50 is stored in the optical cable skin gripping member installation space 61 is improved. There is a problem that it is difficult to confirm that visibility deteriorates when the mechanical splicing is performed, that is, that the optical fibers are reliably in contact with each other.

  The present invention has been made in view of such points, and has an optical fiber gripping portion that has a fine hole in which a built-in optical fiber is embedded in the first half portion and holds an optical fiber in an optical cable to be connected to the second half portion. The fiber ferrule and the optical cable sheath gripping member for gripping the sheath of the optical cable is a mechanical connection type optical connector disposed in the optical connector housing, and the optical cable sheath gripping member is formed by a rear pressing member disposed in the optical connector. The optical connector housing is pressed to the rear side.

  According to the above configuration, the present invention can widen the clearance between the optical cable skin gripping member and the optical cable skin gripping member installation space, and can easily place the optical cable skin gripping member at a predetermined position. ) After assembly, the optical cable sheath gripping member is constantly fixed to the rear side of the optical connector housing, so that the optical cable sheath gripping member does not move forward of the connector and does not increase connection loss. can do.

  The rear pressing member is constituted by a coil spring or a leaf spring.

  The present invention will be described in more detail with reference to the illustrated embodiments. 1-3, 10, 11, 12, 12 ', 12' ', 13, 14, 15, 16, 20, 20', 21, 21 ', 30, 40, 45, 50, 60, 61 are: Similar to FIGS. 5 to 7, the ferrule substrate, the first half of the ferrule 10, the built-in optical fiber, the end face of the built-in optical fiber 12, the end face of the built-in optical fiber 12, the fine hole, the second half of the ferrule 10, the groove, and the optical fiber, respectively. A holding base, an optical cable, a sheath of the optical cable 20, an optical fiber, an end face of the optical fiber 21, a lid, a fastener, an optical fiber gripping portion, an optical cable sheath gripping member, a connector housing, and an optical cable sheath gripping member installation space. Reference numeral 70 denotes a rear pressing member, which is a feature of the present invention, for pressing the optical cable outer sheath holding member 50 against the rear side of the connector in the optical cable outer sheath holding member installation space 61.

  As shown in FIG. 3, the optical cable skin gripping member 50 includes a skin gripping base material 51 and a skin gripping lid 52 that covers the base material. On the upper surface of the outer skin gripping base 51, a V-groove 53 is formed along the longitudinal direction to store an optical cable (not shown) for each outer skin. Further, a step 54 is formed in the middle of the V-groove 53. Bites into the outer sheath of the optical cable disposed in the V-groove, so that the optical cable cannot move in the longitudinal direction in the V-groove 53. In addition, a protrusion 55 is formed on the side surface of the outer skin gripping base 51 and is fitted into a fitting hole 56 formed in the side surface of the outer skin gripping lid 52 so that the outer skin gripping lid 52 is fixed on the upper portion of the outer skin gripping base material 51. It is configured to be.

  In the connector of the present embodiment, the optical cable skin gripping member installation space 61 is provided with a clearance that allows the optical cable skin gripping member 50 to move by a sufficient distance in the front-rear direction of the connector. A rear pressing member 70 for pressing the holding member 50 against the rear end in the optical cable outer cover holding member installation space 61 is provided. In this embodiment, the rear pressing member 70 is formed by forming a plate spring 71 on the connector housing lid 62 that is fixed by being placed on the optical cable outer sheath holding member installation space 61.

  With this configuration, since the optical cable skin gripping member 50 can move forward in the optical cable skin gripping member installation space 61 during the mechanical splice connection operation, the optical fiber 21 is pushed into the groove 15 and the built-in light incorporated in the connector. Since the end face 12 '' of the fiber 12 and the end face 12 'of the optical fiber 12 come into contact with each other and the slack in the optical fiber 21 between the optical cable sheath holding member 50 and the lid 30 can be easily visually confirmed, It can be confirmed that the built-in optical fiber 12 and the optical fiber 21 to be connected are securely placed and connected.

  Furthermore, after assembling the connector housing 60, the optical cable sheath holding member 50 is pressed and fixed to the rear end of the optical cable sheath holding member installation space 61 by the rear pressing member 70 by the leaf spring 71. For this reason, the slack of the optical fiber 21 between the lid 30 and the optical cable outer sheath holding member 50 is held at a constant amount, and does not fluctuate due to impact / vibration on the connector.

  That is, by designing the amount of sag so that the bending loss is in a negligible range, the slack of the optical fiber 21 is surely secured by the sag of the optical fiber 21 during connection work during mechanical splicing. The optical cable skin gripping member 50 can be confirmed in the optical cable skin gripping member installation space 61 while it is possible to visually confirm that it is in contact with the end face 21 ′ and retain a minute amount of slack so that bending loss does not occur after assembly of the connector housing. Since it is stored, bending loss does not occur, and sufficient durability against pulling of the optical cable 20 can be realized.

  4 is different from the embodiment shown in FIGS. 1 and 2 in that the leaf spring 71 is arranged so as to press from the front portion of the optical cable outer sheath holding member 50 in the rearward direction. Even with such a configuration, the optical cable skin gripping member 50 can be pressed backward in the optical cable skin gripping member installation space 61.

  FIG. 5 shows still another embodiment of the present invention. The rear pressing member 70 is constituted by a coil spring 72, and the coil spring 72 is arranged at the front portion of the optical cable outer skin gripping member installation space 61 and the front portion of the optical cable outer skin gripping member 50. And the optical cable skin gripping member 50 is pressed from the front side to the rear side thereof. Even with such a configuration, the optical cable skin gripping member 50 can be pressed backward in the optical cable skin gripping member installation space 61.

The principal part sectional drawing which shows one Example of this invention. The principal part decomposition | disassembly block diagram of the Example shown in FIG. The other exploded block diagram of the Example shown in FIG. The principal part sectional drawing which shows the other Example of this invention. The principal part sectional drawing which shows the further another Example of this invention. The principal part sectional view explaining the composition of the optical connector relevant to the present invention. FIG. 6 is a cross-sectional view of a main part for explaining the configuration of another optical connector related to the present invention. The principal part sectional drawing explaining the structure of the other optical connector relevant to this invention. Sectional drawing which shows an example of a common ferrule board | substrate. Sectional drawing which shows an example of a general optical fiber holding part. The perspective view which shows an example of a general optical fiber fastener.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ferrule board | substrate 11 Front half part 12 Built-in optical fiber 12 'End surface 12''End surface 13 Fine hole 14 Late part 15 Groove 16 Optical fiber holding stand 20 Optical cable 20' Outer skin 21 Optical fiber 21 'End surface 30 Cover 40 Fastening tool 45 Optical fiber Grip part 50 Optical cable skin gripping member 51 Skin gripping base material 52 Skin gripping lid 53 V-groove 54 Step 55 Projection 56 Fitting hole 60 Connector housing 61 Optical cable skin gripping member installation space 62 Connector housing lid 70 Back pressing member 71 Leaf spring 72 Coil spring

Claims (3)

  An optical fiber ferrule having an optical fiber gripping portion for holding an optical fiber in an optical cable to be connected to the latter half portion having a fine hole in which a built-in optical fiber is embedded in the first half portion, and an optical cable sheath for gripping the outer sheath of the optical cable. The gripping member is a mechanical connection type optical connector disposed in the optical connector housing, and the optical cable sheath gripping member is pressed to the rear side of the optical connector housing by the rear pressing member disposed in the optical connector. A mechanical connection type optical connector.   2. The mechanical connection type optical connector according to claim 1, wherein the rear pressing member is formed of a coil spring. 2. The mechanical connection type optical connector according to claim 1, wherein the rear pressing member is formed by a leaf spring.

Images