JP4812652B2 - Optical connector - Google Patents

Description

  The present invention relates to an optical connector in which a pigtail optical fiber whose one end is fixed to a ferrule and an external optical fiber led to the outside are fusion-connected.

  For example, when an optical connector is attached to the end of an optical fiber that has been routed, it is necessary to connect a pigtail optical fiber in the optical connector and an external optical fiber that has already been routed. As a method for connecting the optical fibers, there are a mechanical connection method and a fusion connection method. The fusion splicing method has advantages such as less connection loss in optical transmission than the mechanical connection method and the necessity of using a special connection component at the connection location.

  Conventional optical connectors that employ the fusion splicing method include those disclosed in Patent Documents 1 to 3. The optical connectors disclosed in Patent Documents 2 and 3 cannot fuse optical fibers together unless a dedicated fusion splicer is used. On the other hand, the optical connector disclosed in Patent Document 1 can fuse optical fibers using a widely used fusion splicer. The outline of the configuration of the optical connector disclosed in Patent Document 1 will be described below.

  The optical connector 50 includes a connector housing 51 as shown in FIG. The connector housing 51 includes a connection side housing 52, a stop ring 53, and a boot portion 54. A ferrule 55 is supported in the connection housing 52 so as to be movable in the axial direction. A spring 56 is interposed between the ferrule 55 and the stop ring 53. The ferrule 55 is biased in a direction protruding from the connection side housing 52 by the biasing force of the spring 56. One end of a pigtail optical fiber 57 is fixed in the ferrule 55. The other end of the pigtail optical fiber 57 is fusion-bonded to the end of the external optical fiber 58. The fusion spliced portion is covered with a fusion reinforcing body 59. The fusion reinforcing body 59 is accommodated in the stop ring 53.

In the conventional optical connector 50 shown in FIG. 5, the fusion spliced portion is reinforced by a fusion reinforcing body 59. The fusion reinforcing body 59 is accommodated in the connector housing 51. Further, in the optical connector 50, even if the external optical fiber 58 led to the outside is bent, the fusion spliced portion is protected by the fusion reinforcing body 59, so that no bending force acts on the fusion spliced portion. The handleability of the external optical fiber 50 is good.
JP 2002-82257 A Japanese Patent Laid-Open No. 10-227946 JP 2004-317945 A

  However, in the conventional optical connector 50, the fusion spliced portion reinforced by the fusion reinforcing body 59 is accommodated in a floating state with a gap interposed on the inner side surface of the stop ring 53 of the connector housing 51. Therefore, when vibration is transmitted to the optical connector 50, the fusion spliced portion between the optical fibers 57 and 58 easily vibrates together with the fusion reinforcing body 59. When the fusion spliced portion vibrates, the optical transmission characteristics become unstable. In addition, the mechanical strength of the fusion spliced portion is also reduced by vibration, which is one factor that hinders the long-term reliability of the optical connector 50.

  Accordingly, the present invention provides an optical connector 5 in which a pigtail optical fiber and an external optical fiber are connected by fusion splicing, which can stabilize optical transmission characteristics and improve long-term reliability. The purpose is to do.

  An optical connector according to the present invention includes a connector housing, a ferrule accommodated in the connector housing, a pigtail optical fiber having one end fixed to the ferrule, and one end fused to the other end of the pigtail optical fiber. An external optical fiber led to the outside of the connector housing, and a fusion reinforcing body that covers the fusion-bonded portion between the pigtail optical fiber and the external optical fiber and is accommodated in the connector housing with almost no gap. Is the gist.

  The connector housing may be configured to include a connection side housing in which the ferrule is accommodated, an outer cylinder housing in which the fusion reinforcing body is accommodated, and a boot portion that supports the external optical fiber. The ferrule support unit is assembled to the ferrule, a ferrule support member that supports the ferrule so as to be movable in the axial direction, a spring that biases the ferrule in a direction in which it protrudes from the connection side end of the connector housing, and the ferrule support member. And a spring receiving member from which the other end of the pigtail optical fiber protrudes. Further, the ferrule support unit may be configured to be held by the connection side housing when inserted to the mounting position in the connection side housing.

  In the optical connector according to the present invention, even if vibration is transmitted to the optical connector, there is no gap in the connector housing that causes the fusion-bonded portion between the optical fibers to vibrate together with the fusion reinforcing member. It can suppress that the fusion splicing part between optical fibers vibrates with a fusion | fusion reinforcement body. Therefore, according to the present invention, the optical transmission characteristics of the optical connector are stabilized, and the long-term reliability is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show an embodiment of the present invention, FIG. 1 is an overall front view of an optical connector, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. FIG. 3B is a cross-sectional view showing a state cut along the central axis of the connection portion, and FIG. 4 is a view for explaining an optical connector mounting operation procedure.

  As shown in FIGS. 1 and 2, the optical connector 1 has a connector housing 2. The connector housing 2 includes a connection-side housing 2A that is fitted to the mating optical connector on the front end side (left side in the figure), and a not-shown engagement on the rear end part (right side in the figure) of the connection-side housing 2A. The outer cylinder housing 2B is fixed through a stopping means, and the boot portion 2C is fixed to the rear end of the outer cylinder housing 2B and the external optical fiber 21 is led out from the rear end.

  The connection side housing 2A is formed of, for example, a highly rigid synthetic resin material. As shown in FIG. 2, a ferrule support unit 3 is accommodated in the connection side housing 2A. The ferrule support unit 3 has a cylindrical ferrule 4, a ferrule support member 5 that supports the ferrule 4 so as to be movable in the axial direction, and one end of the ferrule support unit 3 in contact with the flange portion 4a. 1 and 2, and a spring receiving member 7 that receives the other end of the coil spring 6 and is assembled to the ferrule support member 5 by a locking means (not shown). ing.

  When the ferrule support unit 3 is inserted into the connection side housing 2A from the rear end (right direction in FIGS. 2 and 4) to the mounting position, the locking protrusion 5a (see FIG. 4) of the ferrule support member 5 and the like are provided. The connection side housing 2A is fixed by being locked to a not-shown locked portion or the like.

  As shown in FIG. 2, one end side of the pigtail optical fiber 20 is inserted into the ferrule 4. One end side of the inserted pigtail optical fiber 20 is fixed to the ferrule 4. The other end of the pigtail optical fiber 20 extends into the outer cylinder housing 2B.

  The spring receiving member 7 has a cylindrical fitting portion 7a that protrudes toward the rear end side. A front end portion of the outer cylinder housing 2B is fitted to the cylindrical fitting portion 7a via a stop ring 8.

  The outer cylinder housing 2B is made of, for example, a highly rigid synthetic resin material. As described above, the other end side of the pigtail optical fiber 20 is guided into the outer cylinder housing 2B, and the end portion of the external optical fiber 21 is guided from the boot portion 2C side.

  As shown in FIG. 4, the pigtail optical fiber 20 is an optical fiber that includes a fiber core wire 20a and a resin coating layer 20b that covers the outer periphery thereof. As shown in FIG. 4, the external optical fiber 21 is an optical fiber comprising a fiber core wire 21a, a resin inner layer 21b covering the outer periphery, and a tensile cord outer cord layer 21c covering the outer periphery of the resin inner layer 21b. Code.

  As shown in FIGS. 1 and 2, the fiber core wires 20 a and 21 a at the ends of the pigtail optical fiber 20 and the external optical fiber 21 are connected by fusion splicing. The fusion spliced portion between the optical fibers 20 and 21 is sealed along the central axis of the fusion reinforcing body 10 formed in a cylindrical shape. In other words, the fusion spliced portions of the optical fibers 20 and 21 are covered with the fusion reinforcing body 10 using a hot melt adhesive. The fusion-strengthening body 10 is provided with a heat-shrinkable tube made of, for example, a thermoplastic resin on the outer side as necessary. As shown in FIG. 2 and FIGS. 3A and 3B, the fusion reinforcing body 10 has an outer diameter that is substantially the same as the inner diameter of the outer cylinder housing 2B when fitted to the outer cylinder housing 2B. Is set to That is, the fusion reinforcing body 12 is accommodated in the outer cylinder housing 2B with almost no gap.

  A caulking ring 11 is fitted to the rear end portion of the outer cylinder housing 2B. Although not shown in FIG. 2, an outer cord layer 21 c of the outer optical fiber 21 is interposed between the outer cylinder housing 2 </ b> B and the caulking ring 11. A pressing ring 12 is further fitted on the outer periphery of the caulking ring 11. That is, the outer cord layer 21 c of the outer optical fiber 21 is fastened by the caulking ring 11 and the pressing ring 12. As a result, even if a tensile force is applied to the external optical fiber 21 led out from the optical connector 1, the tensile force does not act on the fusion spliced portion. The rear end portion of the caulking ring 11 is crimped.

  The boot portion 2C is made of, for example, a highly flexible synthetic resin material and is easily bent. The boot portion 2 </ b> C is disposed so as to cover the caulking ring 11 and the pressing ring 12. On the front end side of the boot portion 2 </ b> C, an annular protrusion 13 that protrudes toward the inner peripheral side is provided. The boot portion 2C is fixed to the outer cylinder housing 2B by fitting the annular protrusion 13 into an annular recess 14 formed by the rear end portion of the outer cylinder housing 2B and the caulking ring 11.

  Next, an operation for attaching the optical connector 1 to the end of the external optical fiber 21 will be described. As shown in FIG. 4, the ferrule support unit 3 will be described as being assembled in advance.

  First, the boot portion 2 </ b> C, the pressing ring 12, the caulking ring 11, the outer cylinder housing 2 </ b> B, and the fusion reinforcing body 10 are inserted in this order from the end of the external optical fiber 21.

  Next, a part of the endothelial layer 20b on the other end side of the pigtail optical fiber 20 protruding from the rear end of the ferrule support unit 3 is peeled off. The exposed end surface of the fiber core wire 20a is processed. Note that this end face processing can be performed in advance. Further, the resin inner skin layer 21b is peeled off from the end portion of the external optical fiber 21, and the outer skin cord layer 21c is stripped in a wider range than the resin inner skin layer 21b. A part of the peeled cord layer 21 c is left without being cut from the external optical fiber 21. Moreover, the end surface process of the exposed fiber core wire 21a is performed.

  Next, the fiber core wire 20a on the other end side of the pigtail optical fiber 20 and the fiber core wire 21a on the end portion of the external optical fiber 21 are fusion-spliced using a general-purpose fusion splicer. In other words, both the fiber core wires 20a and 21a are respectively arranged on a positioning table facing the fusion splicer and positioned so that the end faces of both fiber core wires 20a and 21a abut each other. Both the positioned fiber cores 20a and 21a are clamped. After clamping, the periphery of the end faces of both fiber cores 20a and 21a is discharged and fused.

  Next, the fusion reinforcing body 10 passed through the external optical fiber 21 is moved to a position that covers the outer periphery of the fusion-bonded portion between the optical fibers 20 and 21. Thereafter, the fusion reinforcing body 10 is heated and melted to cover the connection portions of the fiber core wires 20 a and 21 a with the fusion reinforcing body 10.

  Next, as shown in FIG. 2, the outer cylinder housing 2 </ b> B passed through the external optical fiber 21 is moved to a position covering the outer periphery of the fusion reinforcing body 10, and the front end portion of the outer cylinder housing 2 </ b> B is moved to the ferrule support unit 3. It fits in the cylindrical fitting part 7a (refer FIG. 2) protruded from the rear end. The outer skin cord layer 21c in which the external optical fiber 21 remains is placed on the rear end portion of the outer cylinder housing 2B, and the caulking ring 11 is fitted from above. The pressing ring 12 is further fitted on the caulking ring 11 to fix the outer cord layer 21c. Thereafter, the rear end portion of the caulking ring 11 is crimped.

  Next, the ferrule support unit 3 and the outer cylinder housing 2B are inserted from the rear end side of the connection side housing 2A. When the ferrule support unit 3 and the outer cylinder housing 2B are inserted to a predetermined mounting position with respect to the connection side housing 2A, the ferrule support unit 3 and the outer cylinder housing 2B are respectively connected to the connection side housing 2A by locking means (not shown). Fixed.

  Finally, the boot portion 2C passed through the external optical fiber 21 is moved to a position covering the caulking ring 11 and the holding ring 12, and the annular protrusion 13 of the boot portion 2C is moved to the annular recess at the rear end portion of the outer cylinder housing 2B. 14 is inserted. This completes the installation work.

  In addition, the above-described attachment work procedure is an example and can be changed as appropriate.

  As described above, in the optical connector 1, the fusion reinforcing body 10 that covers the fusion spliced portion between the optical fibers 20 and 21 is provided, and the fusion reinforcing body 10 is accommodated in the outer cylinder housing 2 </ b> B of the connector housing 2 with almost no gap. Therefore, even if vibration is transmitted to the optical connector 1, there is no space in the connector housing 2 where the fusion spliced portion between the optical fibers 20 and 21 vibrates with the fusion reinforcing body 10. Therefore, the fusion spliced portion between the optical fibers 20 and 21 does not swing in the connector housing 2 together with the fusion reinforcing body 10. Therefore, in the optical connector 1 according to the present embodiment, the optical transmission characteristics are stabilized and the long-term reliability is improved.

  In this embodiment, the connector housing 2 includes a connection side housing 2A in which the ferrule 4 is accommodated, an outer cylinder housing 2B in which the fusion reinforcing body 10 is accommodated, and a boot portion 2C that supports the external optical fiber 21. It is configured. Therefore, the connection-side housing 2A, the outer cylinder housing 2B, and the boot portion 2C can be individually made of materials that are compatible with required physical characteristics (for example, strength and bending rigidity).

  In this embodiment, a ferrule 4 to which one end side of the pigtail optical fiber 20 is fixed, a ferrule support member 5 that supports the ferrule 4 so as to be movable in the axial direction, and a coil spring 6 that biases the ferrule 4 in the protruding direction, The ferrule support unit 3 is composed of a spring receiving member 7 assembled to the ferrule support member 5 and protruding from the other end side of the pigtail optical fiber 20. Therefore, since the fusion splicing work between the optical fibers 20 and 21 can be performed with the ferrule support unit 3 assembled in advance, the workability of attaching the optical connector 1 is good.

  In this embodiment, the ferrule support unit 3 is configured to be attached to the connection side housing 2A by a locking means (not shown) when inserted to the mounting position in the connection side housing 2A. Therefore, if the ferrule support unit 3 is inserted into the connection side housing 2A after the fusion splicing operation between the optical fibers 20 and 21, the parts assembling work into the connection side housing 2A is completed. Thus, in this Embodiment, the attachment workability | operativity of the optical connector 1 improves.

  In this embodiment, the fusion reinforcing body 10 is configured to include a heat-shrinkable tube. However, the present invention is not limited to this, and a material and structure that can improve the strength of the fusion spliced portion. Can be adopted.

1 is an overall front view of an optical connector according to an embodiment of the present invention. It is the sectional view on the AA line of FIG. (A) is the BB sectional drawing of FIG. 2, (b) is sectional drawing which shows the state cut | disconnected so that the center axis | shaft of a connection part may be passed. It is a figure explaining the attachment work procedure of the optical connector concerning one embodiment of this invention. It is sectional drawing of the optical connector of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connector 2 Connector housing 2A Connection side housing 2B Outer cylinder housing 2C Boot part 3 Ferrule support unit 4 Ferrule 5 Ferrule support member 6 Coil spring (spring)
7 Spring receiving member 10 Fusion reinforcement 20 Pigtail optical fiber 21 External optical fiber

Claims (5)

A connector housing;
A ferrule housed in the connector housing;
A pigtail optical fiber having one end fixed to the ferrule;
An external optical fiber that is fused and connected to the other end of the pigtail optical fiber and led out of the connector housing;
A fusion reinforcing body that covers the fusion spliced portion of the pigtail optical fiber and the external optical fiber, and is accommodated in the connector housing with almost no gap;
An optical connector comprising: The optical connector according to claim 1,
The connector housing includes a connection-side housing in which the ferrule is accommodated, an outer cylinder housing in which the fusion reinforcing body is accommodated, and a boot portion that supports the external optical fiber. . A claim 1 Symbol placement of the optical connector,
The ferrule, a ferrule support member that supports the ferrule so as to be movable in the axial direction, a spring that biases the ferrule in a direction to protrude from the connection side end of the connector housing, and the ferrule support member are assembled. An optical connector comprising a ferrule support unit including a spring receiving member from which the other end of the pigtail optical fiber protrudes. The optical connector according to claim 2,
The ferrule, a ferrule support member that supports the ferrule so as to be movable in the axial direction, a spring that biases the ferrule in a direction to protrude from the connection side end of the connector housing, and the ferrule support member are assembled. An optical connector comprising a ferrule support unit including a spring receiving member from which the other end of the pigtail optical fiber protrudes. The optical connector according to claim 4 , wherein
The optical connector according to claim 1, wherein the ferrule support unit is held by the connection side housing when inserted to a mounting position in the connection side housing.

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