JP2008102290A - Optical connector and frame fixing jig for optical connector assembly - Google Patents

Abstract

An optical connector is provided which is not likely to be assembled with an inappropriate amount of screwing into a bushing frame.
An optical connector 21 generally corresponds to an FC optical connector and includes a ferrule 3, a spring 5, a frame 24, a bushing 6, and a coupling nut 8. Further, an adapter-type frame fixing jig 22 is provided. A stepless adjustment type key ring 7 having a key portion 7a that can be engaged with a circumferential positioning groove 26b provided on the frame 24 and rotatable with respect to the frame 24 is provided. A notch 24c is provided at the front end of the frame 24 so that the protrusion 27a provided on the jig 22 side can be engaged therewith. In the optical connector assembling process, when the frame 24 portion is fitted to the jig 22, the protrusion 27a is engaged with the notch 24c, and the rotation of the frame is restricted. By screwing the bushing 6 into the frame 24 in this state, the screwing amount (tightening amount) of the bushing 6 can be accurately controlled.
[Selection] Figure 1

Description

  The present invention relates to an optical connector such as an FC optical connector, and a frame fixing jig for assembling an optical connector used for assembling the optical connector.

10 to 12 show a conventional optical connector 1. This optical connector 1 is an optical connector that roughly corresponds to an FC optical connector (F01 type optical connector) defined in JIS C 5970, and accommodates the ferrule 3 to which the optical fiber 2 is fixed and the ferrule 3 therein. A generally cylindrical frame 4 and a generally cylindrical member that is screwed onto the rear portion of the frame 4 and elastically biases the ferrule 3 in the frame 4 forward (leftward in FIG. 10) via a spring 5. And a key ring 7 having a key portion 7a protruding forward so as to be engageable with a circumferential positioning groove of a coupling member for connecting an optical connector such as an adapter (not shown). And a coupling nut 8 that is movably mounted on the outer periphery of the frame 4 and screwed to the outer periphery of the adapter. The bare fiber portion of the optical fiber 2 is indicated by 2a, and the coated portion is indicated by 2b.
A female screw part 4 a is formed on the inner surface of the rear part of the frame 4, and a male screw part 6 a is formed on the outer periphery on the front part side of the bushing 6, and the male screw part 6 a of the bushing 6 is screwed onto the female screw part 4 a of the frame 4. When they are screwed together (pressed in), the flange portion 3a of the ferrule 3 is pressed against the annular inward protruding portion 4b formed on the inner surface of the frame 4 via the spring 5 housed inside. In this case, the biasing force of the spring 5 against the ferrule 3 can be controlled to an appropriate magnitude by appropriately controlling the screwing amount (pushing amount) of the bushing 6. A rubber hood 9 is attached to the rear end of the bushing 6 and protects the vicinity of the entrance of the optical fiber to the optical connector.
A standard key ring in this type of optical connector is an engagement protrusion 7c ′ that engages with an engagement groove provided on the frame side, such as a key ring 7 ′ shown in a perspective view in FIG. On the side opposite to the key portion 7a 'and is attached so as not to rotate relative to the frame. In this case, six engaging grooves of the frame are provided, for example, at intervals of 60 ° in the circumferential direction, and by engaging the engaging protrusion 7c ′ of the key ring 7 ′ with the selected engaging groove as described later, The circumferential position of the key part 7a ′ of the key ring 7 ′ with respect to the frame can be adjusted.
On the other hand, the key ring 7 in the optical connector 1 of FIG. 10 has a stepless adjustment that is rotatably attached to the outer periphery of the frame 4 without the above-mentioned engaging protrusion as shown in the perspective view of FIG. A key ring of the mold (Patent Documents 1 and 2), which is fixed to the outer periphery of the frame 4 with an adjusted adhesive.
The key rings 7 and 7 'are usually provided with slits 7b and 7b' so that the diameter can be enlarged or reduced.

By the way, since there is a slight clearance between the optical fiber (bare fiber 2a) and the optical fiber hole 3b of the ferrule 3, the optical fiber 2a and the optical fiber hole 3b are decentered from each other. The fiber 2a is often fixed in the optical fiber hole 3a. In such an optical connection between the eccentric optical connectors, there is a high possibility that the optical loss becomes large, but the circumferential positions of the key rings 7 and 7 '(the circumferential positions of the key portions 7a and 7a') are eccentric. The key portions 7a and 7a of the key rings 7 and 7 ′ of the pair of optical connectors to be connected to each other are fixed by adjusting according to the direction (usually adjusting while monitoring with a monitor device) and fixing to the frame. When 'is engaged with the circumferential positioning groove of the adapter, the optical fibers of a pair of optical connectors can be butt-connected with a minimum axial misalignment.
The adjustment of the circumferential position of the key part of the key ring with respect to the frame is a six-step adjustment in the case of the standard key ring 7 'shown in FIG. On the other hand, in the case of the key ring 7 shown in FIG. 7A, the frame 4 can be freely rotated and adjusted steplessly at the assembly stage, and the frame 4 can be formed with an adhesive when the circumferential position adjustment is completed. Fixed to.
Japanese Patent Application Laid-Open No. 2002-31743, FIG. 1, FIG. 2, FIG. Japanese Patent Application Laid-Open No. 2003-98385, FIG. 1, FIG. 2, FIG.

In the case of the optical connector having the key ring 7 'shown in FIG. 7 (b), when the bushing is screwed into the frame in the assembly process, the frame engaged with the key ring 7' is fixed to the adapter used for connector connection. When used as a jig and fitted into this, the key portion 7a 'of the key ring 7' engages with the circumferential positioning groove on the adapter side to prevent rotation, thereby preventing the frame from rotating. In the state, the screwing amount of the bushing can be controlled.
However, in the keyring rotation type optical connector 1 having the stepless adjustment type keyring 7 shown in FIG. 7A, the keyring 7 rotates with respect to the frame 4 even when fitted to the adapter. The rotation of 4 cannot be prevented. For this reason, the operation of screwing the bushing 6 into the frame 4 in the assembly process is performed while holding the frame 4 portion by hand.
However, when the work is performed by holding the frame 4 by hand, the frame 4 cannot be fixed completely, and when the bushing 6 is screwed, the frame 4 may rotate together. There is a problem that it is difficult to control accurately.
If the bushing 6 is assembled in a state where the screwing amount is small (a state where the tightening force is weak), the spring 5 in the frame 4 cannot exert a sufficient urging force against the ferrule 3, and a PC (Physical contact) connection cannot be made. There was a problem that defects occurred and yield decreased.

  The present invention has been made to eliminate the above-mentioned conventional drawbacks. In the assembly process of an optical connector having a stepless adjustment type key ring, the frame does not rotate when the bushing is screwed into the frame. It is an object of the present invention to provide an optical connector that can accurately control the screwing amount of the bushing and that is not likely to be assembled when the screwing amount of the bushing is inappropriate.

The present invention that solves the above-described problems includes a ferrule to which an optical fiber is fixed, a substantially cylindrical frame that accommodates the ferrule inside, a screw attached to a rear portion of the frame, and a spring that attaches the ferrule in the frame. A generally cylindrical bushing that elastically urges forward through a key, and a key portion that protrudes forward to engage with a circumferential positioning groove on a coupling member side such as an adapter or a receptacle, and on the outer periphery of the frame In an optical connector comprising: a stepless adjustable key ring that is rotatably attached; and a coupling nut that is movably attached to the outer periphery of the frame and is screwed to the outer periphery of the coupling member.
Frame fixing for optical connector assembly comprising a cylindrical hollow portion for frame fitting into which the front end side cylindrical portion of the frame is fitted, and a circumferential positioning groove for engaging the key portion of the key ring at the front end portion of the frame. The present invention is characterized in that a notch with which a protrusion formed on the cylindrical hollow portion of the jig can be engaged is provided.

Claim 2 is a frame fixing jig for assembling the optical connector used when assembling the optical connector of claim 1,
A cylindrical hollow portion for frame fitting into which a front end side cylindrical portion of the frame of the optical connector is fitted, and a circumferential positioning groove for engaging the key portion of the key ring; A protrusion that can be engaged with the notch is provided.

  According to the present invention, in the optical connector assembling process, when the frame portion of the optical connector is fitted into the frame fixing jig, the protrusion on the frame fixing jig side is engaged with the notch in the frame tip, and the frame Is restricted. By screwing the bushing into the frame in a state where the frame is prevented from rotating, the screwing amount of the bushing can be accurately controlled. As a result, it is possible to prevent the bushing from being assembled in a state where the screwing amount of the bushing is insufficient, and to reduce the generation of defective products in the optical connector assembly process as much as possible.

  Hereinafter, an optical connector and a frame fixing jig for assembling an optical connector according to the present invention will be described with reference to the drawings.

FIG. 1 shows a state immediately before mounting an optical connector 21 according to an embodiment of the present invention on a frame fixing jig 22. The optical connector 21 and the frame fixing jig 22 for assembling an optical connector are shown in half in appearance and half in cross section. 2 is a cross-sectional view taken along line AA of FIG. 1, FIG. 3 is a cross-sectional view taken along line BB of FIG. 1, FIG. 4 is an exploded side view of the optical connector 21, and FIG. FIG.
This optical connector 21 is an optical connector that roughly corresponds to an FC optical connector (F01 type optical connector) defined in JIS C 5970, and accommodates the ferrule 3 to which the optical fiber 2 is fixed and the ferrule 3 therein. A generally cylindrical frame 24 and a generally cylindrical member that is screwed onto the rear portion of the frame 24 and elastically biases the ferrule 3 in the frame 24 forward (leftward in FIG. 1) via a spring 5. And a frame 24 having a key portion 7a projecting forward so as to be engageable with a circumferential positioning groove of a coupling member for connecting an optical connector, for example, an adapter (not shown). A steplessly adjustable key ring 7 that is rotatably attached to the outer periphery of the frame 24 and is attached to the outer periphery of the frame 24 so as to be movable back and forth. And a coupling nut 8 which is screwed on the outer periphery of said adapter. The appearance of the key ring 7 is as shown in FIG. The female thread portion of the coupling nut 8 is indicated by 8a. The bare fiber portion of the optical fiber 2 is indicated by 2a, and the coated portion is indicated by 2b.
A female screw portion 24 a is formed on the inner surface of the rear portion of the frame 24, and a male screw portion 6 a is formed on the outer periphery on the front side of the bushing 6. The male screw portion 6 a of the bushing 6 is screwed onto the female screw portion 24 a of the frame 24. When they are screwed together (pressed in), the flange portion 3a of the ferrule 3 is pressed against the annular inward protruding portion 24b formed on the inner surface of the frame 24 via the spring 5 housed inside. In this case, the biasing force of the spring 5 against the ferrule 3 can be controlled to an appropriate magnitude by appropriately controlling the screwing amount (pushing amount) of the bushing 6. Further, 9 is a washer and 10 is a rubber hood that is attached to the rear end of the bushing 6 and protects the entrance portion of the optical fiber to the optical connector.
As described above, the key ring 7 in the present invention is a stepless adjustment type key ring that is rotatably attached to the outer periphery of the frame 24, and is rotatable with respect to the frame 24 in the assembly stage of the optical connector 21. When the position adjustment is completed, the frame 24 is fixed with an adhesive.

In the present invention, a notch 24c is formed at the front end of the frame 24 so that the protrusion 27a on the frame fixing jig 22 side for assembling the optical connector can be engaged.
Similarly to the adapter for connecting the optical connector, the frame fixing jig 22 has a peripheral portion in which the cylindrical hollow portion 22a for fitting the frame 24d into which the front end side cylindrical portion 24d of the frame 24 is fitted and the key portion 7a of the key ring 7 are engaged. In addition to the direction positioning groove 26b, the cylindrical hollow portion 22a is formed with the protrusion 27a that engages with the notch 24c provided in the frame 24. The frame fixing jig 22 in the illustrated example includes a cylindrical outer member 26 having a flange portion 26c attached to a fixed base plate 25 with, for example, screws, a cylindrical intermediate member 27 mounted on the inside thereof, and the intermediate member The projection 27a is formed integrally with the outer surface of the intermediate member 27. The cylindrical hollow portion 22 a is formed between the inner surface of the outer member 26 and the outer surface of the cylindrical member 27.

When assembling the optical connector 21, the ferrule 3 attached and terminated to the optical fiber 2 is accommodated in the frame 24, and the male screw portion 6 a of the bushing 6 is attached to the frame 24 in a state where the rear portion of the ferrule 3 is covered with the spring 5. Screwed into the female screw portion 24a. Before the bushing 6 is screwed to the final position, the key ring 7 is attached to the outer periphery of the frame 24, and then the circumferential position of the key portion 7a of the key ring 7 with respect to the frame 24 is adjusted.
In this adjustment of the circumferential position, the axial center of the optical fiber 2a and the axial center of the optical fiber hole 3b of the ferrule 3 are often slightly eccentric, so the circumferential position of the key ring 7 (key portion 7a The circumferential position of the key ring 7 is adjusted in accordance with the eccentric direction of the optical fiber (adjusted while being monitored by the monitor device), and the circumferential position adjustment of the key ring 7 has been completed (as shown in FIG. 1). The frame portion of the optical connector 21 is fitted into the cylindrical hollow portion 22a of the frame fixing jig 22. It should be noted that the circumferential relative positional relationship between the outer member 26 and the intermediate member 27 can be adjusted (one can be fixed with respect to the other at an arbitrary rotation angle), and the protrusion 27 a of the frame fixing jig 22 is previously arranged. The circumferential relative position with respect to the circumferential positioning groove 26b is matched with the circumferential relative position between the notch 24c and the key portion 7a on the frame 24 side. As a result, when the frame 24 is pushed into the frame fixing jig 22 so that the key portion 7 a of the key ring 7 engages with the circumferential positioning groove 26 b of the frame fixing jig 22, the notch 24 c at the front end of the frame 24 is inserted. The protrusion 27 a of the frame fixing jig 22 is engaged, and therefore the frame 24 is prevented from rotating by the frame fixing jig 22.
In this state, the bushing 6 is screwed in by a predetermined screwing amount. In this case, since the frame 24 does not rotate, the screwing amount of the bushing 6 can be accurately controlled. Next, the key ring 7 is fixed to the outer periphery of the frame 24 with an adhesive. As a result, the bushing 6 can be prevented from being assembled in a state where the screwing amount is insufficient, and the generation of defective products in the optical connector assembly process can be reduced as much as possible.

The other detailed portions of the structure of the optical connector 21 of the embodiment will be described. Four rotation prevention grooves 3c are formed at four positions in two perpendicular directions of the flange portion 3a of the ferrule 3, and the front end portion of the bushing 6 is formed in the rotation prevention groove 3c. The projecting pieces 6b formed at two locations in the diameter direction are engaged to prevent the ferrule 3 from rotating.
A circumferential protrusion 24 e is formed on the outer periphery of the frame 24, and the inward circumferential protrusion 8 b formed on the inner surface of the rear end portion of the coupling nut 8 contacts the circumferential protrusion 24 e via the washer 9. This prevents the coupling nut 8 from coming off.
A hexagonal flange portion 6c for turning the bushing 6 with a tool is formed on the rear side of the male screw portion 6a of the bushing 6, and a groove in which the annular inward protruding portion 10a on the front end side of the rubber hood 10 is fitted on the rear side. 6d is formed.

  The shape of the cutout 24c on the frame 24 side is not limited to the illustrated shape. The shape is not limited to the shape of the cutout 24c in the embodiment, but may be a groove-shaped cutout 24c 'with a bottom like the frame 24' shown in FIG. Further, in contrast to the groove-shaped notch 24 c ′ opened outward in the radial direction, a groove-shaped notch opened radially inward may be used. In these cases, the projecting portion on the frame fixing jig 22 side also has a shape dimension that can be engaged with the groove-shaped notch.

There are two notches 24c provided at the front end of the frame 24 in the embodiment, but it may be one or more. In the case where a plurality of protrusions are provided, the same number of protrusions are also provided on the frame fixing jig 22 side.
The height of the protrusion 27a on the frame fixing jig 22 side is preferably equal to or less than the depth of the notch 24c.
Further, the frame fixing jig 22 of the embodiment is constituted by the outer member 26, the intermediate member 27, and the sleeve 28. However, the present invention is not limited to this configuration, and the frame fixing jig 22 is for frame fitting for fitting the distal end side cylindrical portion 24d of the frame 24. As long as it has a cylindrical hollow portion 22a and a circumferential positioning groove 26b with which the key portion 7a of the key ring 7 is engaged, a protrusion 27a that can be engaged with the notch 24c on the frame 24 side is formed.

BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which showed the state just before mounting | wearing the optical connector of one Example of this invention to a frame fixing jig, and showed the optical connector and the frame fixing jig for optical connector assembly by the half appearance and the half cross section. . FIG. 3 is an enlarged AA cross-sectional view of FIG. 2. FIG. 3 is an enlarged BB cross-sectional view of FIG. 2. It is a disassembled side view of the said optical connector. It is an expansion perspective view of the frame tip part vicinity of the said optical connector. It is CC sectional drawing in FIG. (A) is a perspective view of a key ring in the optical connector, and (B) is a perspective view of a general key ring shown for explaining the structure of the key ring in the present invention. FIG. 2 is a side view showing the optical connector and the frame fixing jig for assembling the optical connector in a half appearance and a half section, following the state shown in FIG. FIG. 6 is a view corresponding to FIG. 5, showing another embodiment of the shape of the notch formed at the tip of the frame. It is the side view which showed the conventional optical connector by the half external appearance and the half cross section (corresponding | compatible to the right side part of FIG. 1 of this invention). FIG. 11 is an exploded side view of the optical connector of FIG. 10 (corresponding to FIG. 4 of the present invention). FIG. 11 is an enlarged perspective view of the vicinity of the front end of the optical connector of FIG. 10 (corresponding to FIG. 5 of the present invention).

Explanation of symbols

2 Optical fiber 2a Bare fiber 2b Cover part 3 Ferrule 3a Gutter part 3b Optical fiber hole 5 Spring 6 Bushing 6a Male thread part 6b Projection piece 7 Key ring 7a Key part 7b Slot 8 Coupling nut 9 Washer 10 Rubber hood 21 Optical connector 22 Frame fixed Jig 22a Cylindrical hollow portion 24 Frame 24a Female threaded portion 24b An annular inward projecting portion 24c Notch 24d Tip side cylindrical portion 25 Base plate 26 Outer member 26b Circumferential positioning groove 27 Intermediate member 27a Protruding portion 28 Sleeve

Claims (2)

A ferrule to which an optical fiber is fixed, a substantially cylindrical frame that accommodates the ferrule, and a rear portion of the frame that are screwed together and elastically bias the ferrule in the frame forward through a spring. A stepless adjustment type that has a key part that protrudes forward so as to be engageable with a circumferential positioning groove on a coupling member side such as an adapter or a receptacle, and is rotatably attached to the outer periphery of the frame An optical connector including a key ring and a coupling nut that is movably attached to the outer periphery of the frame and is screwed to the outer periphery of the coupling member.
Frame fixing for optical connector assembly comprising a cylindrical hollow portion for frame fitting into which the front end side cylindrical portion of the frame is fitted, and a circumferential positioning groove for engaging the key portion of the key ring at the front end portion of the frame. An optical connector comprising a notch with which a protrusion formed in the cylindrical hollow portion of a jig can be engaged. A frame fixing jig for assembling an optical connector used when assembling the optical connector according to claim 1,
A cylindrical hollow portion for frame fitting into which a front end side cylindrical portion of the frame of the optical connector is fitted, and a circumferential positioning groove for engaging the key portion of the key ring; A frame fixing jig for assembling an optical connector, wherein a protrusion that can be engaged with the notch is provided.

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