JP6018841B2 - Ferrule and optical connector - Google Patents

Description

  The present invention relates to a ferrule and an optical connector.

  In an automotive LAN or the like, an optical connector used for connecting optical fibers is known (for example, see Patent Document 1). As shown in FIG. 8A, this type of optical connector 501 includes a stop ring 507 in which a fiber insertion hole 503 is formed and an optical fiber 505 is disposed in the fiber insertion hole 503, and the periphery of the optical fiber cable 509. A caulking ring 511 for caulking the stop ring 507 and the optical fiber cable 509, a ferrule 513 disposed at the end of the optical fiber 505 in the optical fiber cable 509, and between the ferrule 513 and the stop ring 507 A spring (not shown) arranged, a plug frame 517 fitted to the stop ring 507, a knob 519 fitted to the plug frame 517, a caulking ring 511, and a boot 521 covering a part of the optical fiber cable 509 And.

  As shown in FIG. 8B, the ferrule 513 is disposed at the end of the optical fiber 505 in the optical fiber cable 509, and is formed to have a flange portion 523 and a cylindrical portion 525. ing. Each of the flange portion 523 and the cylindrical portion 525 has a through hole 527. The ferrule 513 can be fixed by penetrating the tip of the optical fiber 505 through the through hole 527 and bonding it with an adhesive or the like. it can.

  In the assembly process of the optical connector 501, the boot 521, the caulking ring 511, and the stop ring 507 are passed through the optical fiber cable 509 in this order. In the optical fiber cable 509, the ferrule 513 is fixed to the optical fiber 505 exposed by removing the outer sheath 529 and the tensile body 531. In the process of crimping the crimp ring 511 to the stop ring 507 and the optical fiber cable 509, pressure is applied from the surroundings using a crimping tool or the like while sandwiching the strength member 531 between the stop ring 507 and the crimp ring 511. Thus, the caulking ring 511 is plastically deformed in the direction of diameter reduction, and the strength member 531 is crimped to the outer periphery of the stop ring 507. The knob 519 is fitted with the plug frame 517, and the boot 521 is disposed so as to cover a part of the stop ring 507, the caulking ring 511, and a part of the optical fiber cable 509, and an optical fiber cable 509 with an optical connector. It was completed as.

JP 2010-266830 A

  However, the ferrule 513 arranged at the end of the optical fiber 505 described above protrudes from the front end surface of the optical connector 501. When the connector is assembled or the connector is fitted, the ferrule 513 is attached to the front end surface of the ferrule 513. It is also conceivable that connector parts come into contact. Therefore, contact scratches may occur on the end surface of the optical fiber 505 exposed on the tip surface of the ferrule 513, and there is a concern that communication failure due to an increase in end surface loss due to contact scratches may occur.

  This invention is made | formed in view of the said condition, The objective is to provide the ferrule and optical connector which can prevent the damage | wound in the end surface of an optical fiber.

The above object of the present invention is achieved by the following configuration.
(1) A ferrule having an axial through-hole for housing an end portion of an optical fiber composed of an optical fiber and a plastic resin covering the optical fiber,
The through-hole is formed from a ferrule tip side from the ferrule leading end, a fiber strand insertion hole portion connected to the ferrule rear end side of the twisting measure hole portion and having an inner diameter larger than the twisting measure hole portion, and the fiber strand insertion portion. A fiber insertion hole connected to the rear end side of the ferrule of the hole and having a larger inner diameter than the fiber strand insertion hole,
The inner diameter of the cavitation countermeasure hole is smaller than the outer diameter of the optical fiber strand, the inner diameter of the fiber strand insertion hole is substantially the same as the outer diameter of the optical fiber strand, and the inner diameter of the fiber insertion hole is Substantially coincides with the outer diameter of the plastic resin covering the optical fiber,
The fiber strand insertion hole contains only the optical fiber strand that is not covered with the plastic resin at the end of the optical fiber, and the fiber insertion hole includes the optical fiber at the end of the optical fiber. The plastic resin covering the optical fiber is stored,
The twist in the connecting portion of the countermeasure hole and the fiber insertion hole, the tip end surface and the contact with the ferrule front end side of the optical fiber of the optical fiber housed in the fiber insertion hole A ferrule characterized by being provided with a stepped portion for restricting movement to the.

  According to the ferrule having the above configuration (1), the tip surface of the optical fiber in contact with the step portion is not exposed to the outside from the tip portion of the ferrule. Therefore, when the optical fiber is transported or the connector is assembled, even if the tip of the ferrule comes into contact with another member such as an assembly jig or a mating connector part, the optical fiber tip is not rubbed. It is possible to prevent scratches on the surface.

(2) An optical connector characterized in that the ferrule having the configuration of (1) is accommodated and held in a connector housing.

  According to the optical connector configured as described in (2) above, there is no squeezing at the time of connector mating and no friction between the end faces of the optical fibers at the time of in-line mating, and staking measures are taken on the connector housing side. Therefore, the optical connector can be made small and inexpensive.

  According to the ferrule and the optical connector according to the present invention, it is possible to prevent the tip surface of the optical fiber from being damaged.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings. .

It is a disassembled perspective view of the optical connector provided with the ferrule which concerns on 1st Embodiment of this invention. It is sectional drawing by the surface containing the axis line of the ferrule shown in FIG. It is a fragmentary sectional view for demonstrating the ferrule assembly provided with the ferrule shown in FIG. It is a horizontal sectional view which shows the in-line fitting state of the optical connector shown in FIG. 1, and the other party optical connector. (A) is a perspective view of the board | substrate mounted optical connector to which the ferrule assembly provided with the ferrule which concerns on 2nd Embodiment of this invention is connected, (b) is sectional drawing of the board | substrate mounted optical connector to which the ferrule assembly was connected. . FIG. 6 is a perspective view showing a laminated board arrangement state of the board-mounted optical connector shown in FIG. 5. It is a longitudinal cross-sectional view for demonstrating the subharness using the ferrule assembly provided with the ferrule which concerns on 3rd Embodiment of this invention. (A) is the top view which fractured | ruptured and expanded some conventional optical connectors, (b) is a longitudinal cross-sectional view of the ferrule shown to (a).

Embodiments according to the present invention will be described below with reference to the drawings.
The optical connector 11 provided with the ferrule 19 according to the first embodiment of the present invention and the mating optical connector 30 (see FIG. 4) are coupled to each other so that the ends of the optical fibers 17 of the two pairs of ferrule assemblies 25 are abutted. It is an optical connector that is connected to the state (in-line fitting).

As shown in FIG. 1, the optical connector 11 according to the first embodiment includes a connector housing 21 that houses a ferrule 19 connected to an end of an optical fiber 17 in a rear opening 23, and the ferrule 19 in the connector housing 21. And a holder 24 that is housed and held therein.
The connector housing 21 made of synthetic resin has a coupling opening 31 with the counterpart optical connector 30 in the front. A pair of ferrules 19 are accommodated in the back side of the coupling opening 31, and a holder mounting opening (not shown) is formed on the lower surface of the connector housing 21, so that the holder mounting opening can receive the holder 24.

As shown in FIG. 4, the mating optical connector 30 according to the first embodiment includes a connector housing 32 that houses the ferrule 19 connected to the end of the optical fiber 17 in the rear opening 38, and the ferrule 19 is connected to the connector housing 32. And a holder 33 that is housed and held therein.
The connector housing 32 made of synthetic resin has a coupling opening 34 with the optical connector 11 in the front. On the back side of the coupling opening 34 in which the pair of ferrules 19 are accommodated, there is provided a guide part 36 for inserting and guiding the ferrule 19 of the optical connector 11 and fitting the ferrules 19 together when the connector is fitted.

  The optical fiber 17 is configured by covering an optical fiber strand 27 with a plastic resin 29. As the type of the optical fiber 17, an optical fiber strand 27 made of a material such as quartz or plastic can be used.

  The ferrule 19 of the present embodiment is equipped with a measure against scratching. The ferrule 19 can be made of, for example, zirconia. As shown in FIG. 2, the ferrule 19 has a through-hole 41 formed of a shaft-preventing hole 35, a fiber strand insertion hole 37, and a fiber insertion hole 39 coaxially penetrating from the distal end side of the shaft body. Is formed. On the outer peripheral side of the shaft body, an annular flange portion 43 is formed to project outward in the radial direction at a substantially central portion in the axial direction, and an annular rear end portion 45 of substantially the same outer diameter is radially outward on the rear side in the axial direction. Overhangs and is formed.

An inner diameter D <b> 2 of the fiber strand insertion hole 37 substantially matches the outer diameter of the optical fiber strand 27. The inner diameter D3 of the fiber insertion hole 39 substantially matches the outer diameter of the optical fiber 17 in which the optical fiber strand 27 is covered with the plastic resin 29. An inner diameter D <b> 1 of the caulking countermeasure hole 35 is formed to be smaller than an outer diameter of the optical fiber strand 27. That is, the sizes of the inner diameter D1 of the squeeze countermeasure hole 35, the inner diameter D2 of the fiber strand insertion hole 37, and the inner diameter D3 of the fiber insertion hole 39 have a relationship of D1 <D2 <D3.
The opening end 49 of the through hole 41 at the tip portion 47 of the ferrule 19 is in contact with the fiber end surface 51 (the fiber end surface 51 of the optical fiber strand 27) that is the tip surface of the optical fiber 17 accommodated in the through hole 41. A fiber stopper portion 53 that is a step portion that contacts and regulates the movement of the optical fiber 17 toward the distal end side of the ferrule is provided. The fiber stopper 53 in the present embodiment is formed in an annular shape that protrudes from the opening edge of the opening end 49 toward the center of the opening, and is in contact with the entire outer periphery of the fiber end surface 51, but the ferrule of the optical fiber 17. Needless to say, various shapes such as contacting a part of the outer periphery of the fiber end face 51 can be adopted as long as the movement toward the distal end side can be regulated.

In addition, as shown in FIG. 3, both ends of the optical fiber 17 whose end face is preliminarily treated (cut or cleaved) are inserted into the ferrule 19 and the end face 51 is aligned with the fiber stopper 53. The ferrule assembly 25 is configured by being fixed by laser welding, adhesion, or the like.
Therefore, one end of the ferrule assembly 25 is inserted into the connector housing 21, the holder 24 is pushed up, and the ferrule 19 is accommodated and held in the connector housing 21, thereby configuring the optical connector 11. Further, the other end of the ferrule assembly 25 is inserted into the connector housing 32, the holder 33 is pushed up, and the ferrule 19 is accommodated and held in the connector housing 32, whereby the counterpart optical connector 30 is configured.

Next, operations of the optical connector 11 and the counterpart optical connector 30 including the ferrule 19 having the above-described configuration will be described.
As shown in FIG. 3, in the ferrule 19 according to the present embodiment, the fiber end surface 51 of the optical fiber 17 in contact with the fiber stopper portion 53 is outward from the opening end 49 of the through hole 41 in the tip portion 47 of the ferrule 19. Not exposed.
Therefore, even when the tip 47 of the ferrule 19 contacts the assembly jig or the connector housing 21 when the ferrule assembly 25 is transported or the connector is assembled, the fiber end surface 51 is not rubbed, and the fiber end surface of the optical fiber 17 is not rubbed. 51 can be prevented from being damaged. As a result, it is possible to prevent the inability to communicate due to damage to the fiber end face 51 due to contact with other members during assembly of the connector or galling during connector fitting.

  In addition, in the case of in-line fitting that is a straight connection, pistoning may occur due to environmental changes or the like. In this case, it is also conceivable that the fiber end faces that are abutted will rub against each other when subjected to vibration while the fiber end faces are in contact with each other. However, in the in-line fitting of the optical connector 11 and the counterpart optical connector 30 according to the first embodiment, as shown in FIG. 4, the optical connector 11 is provided at the opening end 49 of the through hole 41 in the tip portion 47 of the ferrule 19. Since the fiber stopper portion 53 physically suppresses the pistoning (extension direction) of the optical fiber 17 in each connector, it is effective in stabilizing the optical loss.

  When the optical connector 11 and the mating optical connector 30 are fitted and the tip portions 47 of the ferrule 19 are brought into contact with each other, the distance between the fiber end faces 51 of the optical fiber 17 that is deeper than the opening end 49 due to galling. Is wider than that of a normal ferrule. Therefore, in order to minimize the connection loss due to the increase in the distance between the fiber end faces 51, the thickness of the fiber stopper 53 and the core diameter of the optical fiber 27 are appropriately set.

The ferrule assembly 25 including the ferrule 19 according to the second embodiment of the present invention shown in FIGS. 5 and 6 connects between the board-mounted optical connectors 60 respectively mounted on the plurality of circuit boards 75 arranged in a stacked manner. Is.
The ferrule 19 of the ferrule assembly 25 is coupled to the board mounted optical connector 60. The board-mounted optical connector 60 includes an insulating housing 63, a FOT (Fiber Optic Transceiver; hereinafter referred to as an optical transceiver 71), and a shield case 65. The optical transceiver 71 is for mutually converting electrical signals and optical signals and transmitting and receiving them. The optical transceiver 71 is accommodated inside the insulating housing 63.

The board-mounted optical connector 60 is arranged at, for example, the card edge of the circuit board 75, so that connection to and from the circuit board 75 can be made from the edge of the circuit board 75. When the board-mounted optical connector 60 is fitted and coupled to the ferrule 19 of the ferrule assembly 25, the tip of the optical fiber strand 27 of the optical fiber 17 is connected to the optical transceiver 71.
The optical transceiver 71 is provided with a pair of ferrules 70 each having the center of the optical path of the photoelectric conversion element as the axis of the cylindrical portion 72. Each ferrule 70 passes through the partition wall of the insulating housing 63. The ferrule 70 is formed separately or integrally with the optical transceiver body. The ferrule 70 is made of a transparent resin material and has a lens portion 73 at the bottom of the cylindrical portion 72. The lens unit 73 is disposed in front of the light receiving element of the receiving optical transceiver and the light emitting element of the transmitting optical transceiver. Thereby, the optical fiber strand 27 in the ferrule 19 fitted to the ferrule 70 and the photoelectric conversion element of the optical transceiver 71 are aligned easily and with high accuracy.

  The insulating housing 63 that houses the optical transceiver 71 is covered with a shield case 65. The shield case 65 is configured by forming a conductive metal plate in a box shape. Case side surface portions 65b are bent in parallel on both sides of the case top plate portion 65a, and the rear side of the case side surface portions 65b It is closed by a case back surface portion 65c that is bent from the case top plate portion 65a.

  A lance 61 is provided in front of the ferrule 70 in the insulating housing 63. The lance 61 is fitted between the annular flange portion 43 and the rear end portion 45 of the ferrule 19 of the ferrule assembly 25, so that the tip portion 47 of the ferrule 19 is fitted to the cylindrical portion 72 of the optical transceiver 71. Keep in state.

  When the ferrule 19 of the ferrule assembly 25 is fitted to the ferrule 70 of the board-mounted optical connector 60, the fiber end surface 51 of the optical fiber strand 27 that is in contact with the fiber stopper 53 even if scouring occurs is the tip of the ferrule 19 Since the fiber end face 51 is not exposed to the outside, the fiber end face 51 is not rubbed, and damage to the fiber end face 51 of the optical fiber 17 can be prevented.

  The optical transceiver 71 of the board-mounted optical connector 60 adjusts the focal position of the lens unit 73 so that the fiber end surface is also connected to the ferrule 19 in which the fiber end surface 51 is deeper than the opening end 49 due to galling. Connection with a normal ferrule exposed at the open end can be easily handled, and connection loss does not occur.

  The subharness 80 using the ferrule assembly 25 including the ferrule 19 according to the third embodiment of the present invention shown in FIG. 7 is connected to an unillustrated counterpart via optical connectors 81 respectively connected to both ends of the optical fiber 17. It is connected between optical connectors.

The optical connector 81 according to the third embodiment includes a connector housing 83 that houses the ferrule 19 connected to the end of the optical fiber 17, and a holder 85 that houses and holds the ferrule 19 in the connector housing 83.
The connector housing 83 made of synthetic resin has a coupling opening 86 with a counterpart optical connector in the front. A pair of ferrules 19 is accommodated in the back side of the coupling opening 86, and the ferrule 19 is accommodated and held in the connector housing 83 by the holder 24 attached to the holder attachment opening formed on the lower surface of the connector housing 83.

As described above, in the ferrule 19 according to the present embodiment, the fiber end surface 51 of the optical fiber 17 in contact with the fiber stopper portion 53 is exposed to the outside from the opening end 49 of the through hole 41 in the tip portion 47 of the ferrule 19. In addition, the fiber end face 51 is not rubbed due to galling or the like when the connector is fitted.
Therefore, on the connector housing 83 side of the optical connector 81 according to this embodiment, it is not necessary to take measures against squeezing, and the hood portion 87 that forms the coupling opening 86 of the connector housing 83 can be made shorter than that of the conventional connector. That is, the conventional optical connector is configured to guide the mating optical connector by lengthening the hood portion of the connector housing in order to prevent galling during connector fitting. On the other hand, the connector housing 83 according to the present embodiment, which does not need to take measures against squeezing, can form the tip of the hood portion 87 at substantially the same position as the tip portion 47 of the ferrule 19. Can be shortened.
Note that a further miniaturized connector housing can be configured by projecting the tip 47 of the ferrule 19 beyond the tip of the hood 87.

Therefore, according to the ferrule 19 and the optical connectors 11, 13, 81 according to the present embodiment, the fiber end surface 51 of the optical fiber 17 can be prevented from being damaged, and communication failure due to an increase in end surface loss due to contact damage can be prevented. it can.
In addition, the ferrule and optical connector of this invention are not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

DESCRIPTION OF SYMBOLS 11 ... Optical connector 17 ... Optical fiber 19 ... Ferrule 21 ... Connector housing 25 ... Ferrule assembly 41 ... Through-hole 47 ... Tip part 49 ... Open end 51 ... Fiber end surface (tip surface)
53 ... Fiber stopper part (step part)

Claims (2)

A ferrule having an axial through hole for accommodating an end portion of an optical fiber composed of an optical fiber and a plastic resin covering the optical fiber,
The through-hole is formed from a ferrule tip side from the ferrule leading end, a fiber strand insertion hole portion connected to the ferrule rear end side of the twisting measure hole portion and having an inner diameter larger than the twisting measure hole portion, and the fiber strand insertion portion. A fiber insertion hole connected to the rear end side of the ferrule of the hole and having a larger inner diameter than the fiber strand insertion hole,
The inner diameter of the cavitation countermeasure hole is smaller than the outer diameter of the optical fiber strand, the inner diameter of the fiber strand insertion hole is substantially the same as the outer diameter of the optical fiber strand, and the inner diameter of the fiber insertion hole is Substantially coincides with the outer diameter of the plastic resin covering the optical fiber,
The fiber strand insertion hole contains only the optical fiber strand that is not covered with the plastic resin at the end of the optical fiber, and the fiber insertion hole includes the optical fiber at the end of the optical fiber. The plastic resin covering the optical fiber is stored,
The twist in the connecting portion of the countermeasure hole and the fiber insertion hole, the tip end surface and the contact with the ferrule front end side of the optical fiber of the optical fiber housed in the fiber insertion hole A ferrule characterized by being provided with a stepped portion for restricting movement to the.   An optical connector, wherein the ferrule according to claim 1 is accommodated and held in a connector housing.

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