JP4302005B2 - Field assembly optical connector - Google Patents

Description

  The present invention relates to a field-assembled optical connector that employs a mechanical splicing system that abuts the end faces of two bare fibers in connection of optical fibers and presses and fixes the vicinity of the butt joint portion from the side of the bare fibers. About.

  In the conventional mechanical splice method, an optical fiber core wire is introduced into the splice member from the rear, the first optical fiber and the second optical fiber exposed from the tip of the optical fiber core wire are abutted, and the splice member is clamped. In the one fixed to the optical fiber core wire, a first refractive index matching material is injected into a region where the rear end face of the first optical fiber and the front end face of the second optical fiber are abutted, and a second splicing member is provided on the splice member. A technique is provided in which a second refractive index matching material is injected into the light introducing portion, and a wedge insertion slit is formed on one side surface of a splice member including a base member and a cover member.

  However, in the conventional optical fiber connection, the refractive index matching material is incorporated in two dispersed states, and the optical fiber core wire is inserted by inserting a wedge into the wedge insertion slit of the splice member in this state. For this reason, not only is the connection work complicated, but it is necessary to push open the splice member against the pressing force of the clamp member, and at this time, a dedicated external tool is required to push open.

Therefore, the present applicant can assemble the optical fibers easily and in a short time by enabling the alignment and holding of the fibers at the same time without using an external tool for assembly. As shown in FIG. 9, a fiber hole a having both ends opened is formed in the axial direction as shown in FIG. 9, and the fiber hole a is located on the side where the abutting connection part c of the optical fiber b to be inserted is located. A ferrule e provided with a recessed portion d that reaches, a chuck g that covers the recessed portion d so as to press down the butting connection portion c on the lower surface side, and has a tapered surface f from the front portion toward the rear portion on the upper surface side; A bushing in which a fitting hole i having a tapered inner surface h in part is formed at the front end portion so as to be in close contact with the tapered surface f from the outside, and a guide fiber hole j is formed coaxially communicating with the fiber hole a of the ferrule e. k and bush A fitting hole l for fitting from the outside is formed at the front end, a tapered fiber hole m communicating coaxially with the guiding fiber hole j of the bush k is formed at the rear end, and a cable clamp unit at the rear end. a holding member n that can be mounted o, and a lock member (not shown) that presses or urges the lower surface of the chuck g to the recess d of the ferrule 2 via a bush k. Proposed and filed a field assembly optical connector.
JP-A-11-160563 Japanese Patent Application No. 2003-432026

However, the above-described invention has the following problems.
That is, the chuck g fitted in the recess d of the ferrule e is pressed and urged toward the fiber hole a by fitting the fitting hole i of the bush k, for example, as shown in FIG. The rear end of the chuck g to which the optical fiber b is not inserted is easily bent downward, and when the optical fiber b is subsequently inserted into the fiber hole a, the front end b ′ of the optical fiber b becomes the rear end of the chuck g. There is a risk of hitting.

  The present invention solves the above-described problems, and provides an on-site assembly optical connector that can be smoothly inserted to a predetermined position of an optical fiber hole without the front end of the optical fiber hitting the rear end of the chuck. Objective.

In order to achieve the above object, in the present invention, a fiber hole having both ends opened in the axial direction is provided, and a bottom surface reaching the fiber hole is formed on the side where the abutting connection part of the inserted optical fiber is located. A ferrule that is provided with a horizontal recess, and is fitted into the recess so as to hold down the abutting connection portion on the lower surface side, and has a tapered surface from the front to the rear on the upper surface, and the lower surface on the bottom of the ferrule recess a chuck formed in the corresponding horizontal bottom surface, has a tapered inner surface to the front upper wall to slide in close contact from the outside tapered surface of the chuck, fitted with respective parallel horizontal inner surface to the rear upper wall and front and rear subordinates wall A bushing in which a joint hole is formed at the front end and a guide fiber hole is formed coaxially communicating with the fiber hole of the ferrule, and a fitting hole that fits into the bush from the outside is formed at the front end. Tapered fiber hole communicating with use fiber hole coaxially formed in the rear end portion, a holding member of the cable clamp unit and can be mounted on the rear end portion, the bushing between the front portion and the bushing front end portion of the holding member The bushing is pressed against the pressing elastic force of the elastic member by inserting it into the insertion hole of the frame while pressing and biasing forward, and the taper surface of the chuck and the taper inner surface of the bush are in close contact with each other On the other hand, the elastic expansion force of the elastic member works by detaching it from the insertion hole of the frame, and the bush is urged and moved toward the ferrule side, and the taper surface of the chuck and the taper inner surface of the bush are brought into close contact with each other. In an optical connector comprising a lock member ,
A protrusion is provided behind the lower surface of the chuck so that the rear end of the chuck can be held at a required position above the bottom surface of the recess of the ferrule.

  A total of two protrusions are provided on both sides of the fiber hole provided in the center of the bottom of the ferrule recess.

  Since the present invention is configured as described above, after fitting the chuck to the recess of the ferrule so as to close the fiber hole provided on the bottom surface, the bush is fitted from the outside. An optical fiber is inserted into the fiber hole from the rear end, but the rear end of the chuck is held in a required position above by a protrusion provided on the lower surface thereof and can be prevented from bending downward. The front end of the fiber does not hit the rear end of the chuck, and smooth insertion is possible. Therefore, the assembly workability at the site is excellent.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. Reference numeral 1 shown in FIG. 1 to FIG. 3 is matched with a ferrule (not shown) on the other side, so that This is an on-site assembling type optical connector having a substantially rectangular shape for connection with the inserted optical fiber P. The optical connector 1 includes a bush 3 into which the rear end portion of the ferrule 2 is inserted, a holding member 4 that is inserted so that the bush 3 is slightly movable in the front-rear direction, and a frame 5 that is fitted to the holding member 4. And a knob 6 that covers the outside of the frame 5.

  In the ferrule 2, a fiber hole 2A having both ends opened in a rectangular shape is formed in the axial direction, and reaches the fiber hole 2A on the rear side where the abutting connection portion C of the optical fiber P to be inserted is located. A rectangular recess 8 is provided. In the fiber hole 2A, the optical fiber P 'is inserted in advance on the front side of the optical fiber P to the butting connection portion C, and the front end of the ferrule 2 is polished.

  The recess 8 has a bottom surface 8A formed horizontally and a front end 8B and a rear end 8C formed vertically. The fiber hole 2A formed at the center in the axial direction of the bottom surface 8A is formed with a depth (height) dimension in which the upper end of the optical fiber P ′ to be inserted in advance protrudes slightly.

  Further, a plate-like chuck 7 having a tapered surface 7A inclined forward from the front portion toward the rear portion on the upper surface side and a horizontal bottom surface 7B corresponding to the bottom surface 8A of the concave portion 8 of the ferrule 2 is provided on the lower surface side. Yes.

  Then, by fitting the chuck 7 into the recess 8 of the ferrule 2, an optical fiber P ′ inserted into the fiber hole 2A on the front side of the abutting connection portion C of the core of the optical fiber P; Thereafter, the optical fiber P inserted from the rear of the fiber hole 2A is pressed from above so that the alignment can be accurately maintained.

  By the way, as described above, the chuck 7 fitted in the recess 8 of the ferrule 2 is pressed and urged toward the fiber hole 2A side by fitting the bush 3, for example. In particular, since the rear end of the chuck 7 to which the optical fiber P is not inserted is easily bent downward, when the optical fiber P is inserted into the fiber hole 2A later, the front end P1 of the optical fiber P is moved to the rear of the chuck 7. There is a risk of hitting the edge.

  Therefore, two small projections 7C are provided at the rear end of the horizontal bottom surface 7B of the chuck 7 and on both sides of the fiber hole 2A so as to protrude downward, and when the chuck 7 is fitted into the recess 8 of the ferrule 2. Each protrusion 7C abuts on both sides of the fiber hole 2A on the bottom surface 8A of the recess 8 so that the rear end of the chuck 7 can be held at a required upper position. As a result, there is no hindrance to smooth insertion of the optical fiber P into the fiber hole 2A. A guide roundness is formed at the lower edge of the rear end of the chuck 7. Further, a notch 7D that can be fitted and held in the front end 8B of the recess 8 of the ferrule 2 is formed at the front end of the horizontal bottom surface 7B of the chuck 7.

  The fiber hole 2 </ b> A provided in the axial direction of the ferrule 2 extends from the bottom surface 8 </ b> A of the recess 8 through the rear end 8 </ b> C to the end of the ferrule 2. At the end of the ferrule 2, a diverging guide fiber hole 2B having a diameter larger than that of the fiber hole 2A is formed.

  Further, a bush 3 is provided in which a guide fiber hole 3A having a diameter larger than that of the fiber hole 2A of the ferrule 2 and extending toward the opening end is formed on the rear end side. A rectangular fitting hole 9 into which the ferrule 2 and the chuck 7 are fitted is formed in the bush 3 at the front end, and after assembly, the bush 3 is coaxially connected to the fiber hole 2A of the ferrule 2. It is.

  A tapered inner surface 9A is formed on the upper surface of the inner wall in front of the rectangular fitting hole 9 so as to be in close contact with the tapered surface 7A of the chuck 7, and a horizontal upper inner surface 9B communicates with the tapered inner surface 9A on the upper surface of the rear inner wall. A horizontal lower inner surface 9C is formed on the lower surface of the front and rear inner walls so as to be parallel to the horizontal upper inner surface 9B. As shown in FIG. 7, the horizontal upper and lower inner surfaces 9 </ b> B and 9 </ b> C are slightly so as to absorb the warp of the rear end of the chuck 7 caused by the protrusion 7 </ b> C hitting the bottom surface 8 </ b> A of the recess 8. A gap a is formed.

  Further, a rectangular holding member 4 is provided in which a tapered fiber hole 4A having a diameter larger than that of the fiber hole 2A and further diverging toward the opening end on the rear end side is formed at the rear end. The holding member 4 is formed with a rectangular fitting hole 4 </ b> C that fits into the bush 3 from the outside, and communicates coaxially with the guiding fiber hole 3 </ b> A of the bush 3 after assembly. It is like that. A cable clamp unit 21 to be described later can be attached to the rear end of the holding member 4.

  In the rectangular annular space S1 formed between the front end portion of the holding member 4 and the flange-like engaging portion 3B formed on the outer surface side of the front end portion of the bush 3, for example, a coil spring as the elastic member 10 is provided. However, the bush 3 is interposed and disposed.

  The frame 5 is formed in a rectangular cylinder shape so that the rectangular holding member 4 can be inserted. A flange-like locking projection 4B is formed on the outer surface side of the holding member 4, and the frame 5 is engaged with the locking projection 4B. A tongue-like engagement claw piece 5A slightly inclined toward the inner side of the cylinder of the frame 5 is provided so as to be held on the rack. In addition, a pair of two lock member insertion holes 5C penetrating vertically are provided at predetermined intervals on the left and right sides of the frame 5 on the slightly forward side.

  Further, the bush 3 is moved to the holding member 4 side by insertion, and the taper surface 7A of the chuck 7 and the taper inner surface 9A of the fitting hole 9 of the bush 3 are released, while the bush 3 is removed by being removed. Is moved to the mating ferrule 2 side, and a lock member 11 is provided for bringing the tapered surface 7A of the chuck 7 and the tapered inner surface 9A of the fitting hole 9 of the bush 3 into close contact with each other.

  The lock member 11 is erected with a predetermined interval on both sides of the lock plate 12 and the lock plate 12, that is, an interval that allows insertion into the insertion hole 5 </ b> C of the frame 5 while passing through both sides of the ferrule 2. A bifurcated leg 13 is provided. Each bifurcated leg portion 13 is formed with a wide base at the base side and a narrow width at the tip side through a tapered portion 13a.

  Thus, when the bifurcated leg portion 13 of the lock member 11 is inserted from one insertion hole 5C of the frame 5, an inward projection 5B projecting from the cylinder inner wall surface of the frame 5 and the bush 3 outer surface side are formed. Further, it is inserted into the other insertion hole 5C through both sides of the ferrule 2 of the space portion S2 formed between the flange-shaped locking portions 3B, and the narrow tip protrudes and is held outward of the frame.

When the bifurcated leg portion 13 of the lock member 11 is inserted into the insertion hole 5C of the frame 5 in this way, the bush 3 is directed toward the holding member 4 against the pressure expansion elastic force of the coil spring which is the elastic member 10. The pressing is performed so that the taper is pushed away, and the taper surface 7A of the chuck 7 and the taper inner surface 9A of the fitting hole 9 of the bush 3 are released from each other. Incidentally, the bush 3 on the way this insertion is pushed gradually toward the holding member 4 side by the locking portion 3B is sliding from the tapered portion 13a to the base side of the thick width of the bifurcated legs 13, moves.

  On the other hand, when the bifurcated leg portion 13 of the lock member 11 is removed from the insertion hole 5C of the frame 5, the bush 3 is directed toward the ferrule 2 by leaving the pressure expansion elastic force of the coil spring as the elastic member 10 to the left. The abutting connection portion C is pressed on the lower surface side of the chuck 7 by urging and moving the taper surface 7A of the chuck 7 and the taper inner surface 9A of the fitting hole 9 of the bush 3 in close contact with each other.

  The ferrule 2 has a rectangular shape up to a depth near the fiber hole 2A facing the space S2 formed between the inward projection 5B of the frame 5 and the flange-like locking portion 3B on the outer surface side of the bush 3. A groove portion 14 is provided. In addition, a slit 15 for mounting the filter is formed in the groove 14 from the bottom to a position where the optical fiber P ′ in the fiber hole 2 </ b> A is cut and reaches the ferrule 2. The groove 14 is covered with a metal cylindrical holder 16 with a flange. At this time, the filter mounting slit portion 15 is disposed so as to be located directly below the intermediate portion of the holder 16.

  On the other hand, as shown in FIG. 4, the cable clamp unit 21 has a central optical fiber through hole 22 through which the optical fiber P passes and an outer jacket Q that is torn to the left and right with respect to the optical fiber P. It is provided with a jacket insertion groove 23 branched into left and right forks that can be inserted and held. That is, a structure in which the outer cover Q of the two cores is torn and suppressed so that the bending of the optical fiber P is absorbed by the cable clamp unit 21, and the outer cover Q divided into two branches is, for example, a pair of holding metal fittings in the shape of comb teeth 24A. 24 is held firmly.

  The cable clamp unit 21 is formed of two molded parts including a body portion 25 having an optical fiber through hole 22 and a jacket insertion groove 23, and a lid portion 26 formed of a transparent member. . By forming the lid portion 26 with a transparent member in this way, the state of the space portion and the state of the optical fiber P and the jacket Q can be seen through the transparent member, and connection work, maintenance, etc. are easy. can do. A boot 27 is fitted on the outer periphery of the cable clamp unit 21.

Next, in order to explain an example of use and assembly of the best mode configured as described above, first, the optical fiber P is attached to the cable clamp unit 21.
In other words, the optical fiber P core wire is passed through the optical fiber through hole 22 in the center of the cable clamp unit 21 and at the same time the jacket insertion groove 23 branched into the left and right bifurcated is bifurcated to the left and right with respect to the optical fiber P. After the jacket Q that has been torn apart is inserted, the jacket Q is sandwiched and fixed via a pair of holding fittings 24. In this way, since the outer jacket Q that has been split into two is fixed by the left and right outer jacket insertion grooves 23, a long degree of freedom is imparted to allow the optical fiber P that has come out of the central optical fiber through hole 22 to bend. It is.

  Next, the cable clamp unit 21 is connected to the optical connector 1. That is, the bifurcated leg portion 13 of the lock member 11 is inserted into the insertion hole 5C of the frame 5 in advance. At this time, when the bifurcated leg portion 13 is inserted into the space S2 between the frame 5 and the bush 3, the bush 3 is moved to the holding member 4 side, and the tightening force to the chuck 7 is released. At this time, the protrusion 7C provided on the lower surface of the rear end of the chuck 7 allows the front end P1 of the optical fiber P to be smoothly inserted without hitting the rear end of the chuck 7, as described above.

  After the cable clamp unit 21 is connected to the optical connector 1, the bifurcated leg portion 13 of the lock member 11 is removed from the insertion hole 5 </ b> C of the frame 5 after abutment at the connection portion C of the core wire into which the optical fiber P is inserted. By detaching, the bushing 3 is biased and moved toward the counterpart ferrule 2 by the pressure expansion elastic force of the elastic member 10, and a clamping force is applied to the chuck 7, and the taper surface 7A of the chuck 7 and the bush Thus, the abutting connection portion C and the vicinity thereof are pressed on the lower surface side of the chuck 7 by bringing the tapered inner surfaces 9A of the three fitting holes 9 into close contact with each other.

  Thus, the alignment and holding of the core of the optical fiber P are performed simultaneously. That is, one side of the bush 3 contacts the ferrule 2 and the other side contacts the tapered surface 7A of the chuck 7 to convert the elastic force of the elastic member 10 into the fiber tightening direction. Thereafter, a boot 27 is fitted on the outer periphery of the cable clamp unit 21. A knob 6 is fitted on the outer side of the frame 5 of the optical connector 1 to be in a completed state.

The main part of the optical connector in the best form for implementing this invention is shown, (a) is sectional drawing of the state which pressed the bush toward the holding member side with the inserted locking member, (b) FIG. 6 is a cross-sectional view of a state where the bush is moved toward the ferrule side by the removed lock member. It is a disassembled perspective view of the optical connector principal part. Similarly, the whole optical connector is shown, (a) is a cross-sectional view seen from the plane side, (b) is a partially cut-away cross-sectional view seen from the side surface side. The cable clamp unit is shown, (a) is a side view, (b) is an XX sectional view of (a), and (c) is a YY sectional view of (a). It is an expanded sectional view which shows the principal part of an optical connector same as the above. It is the perspective view seen from the back surface side of the chuck | zipper which comprises a principal part same as the above. It is an expanded sectional view of a part of the main part same as the above showing a state where an optical fiber is inserted. It is a partial expanded sectional view which shows the state in the middle of insertion of an optical fiber. It is sectional drawing which shows the conventional optical connector whole. It is an expanded sectional view which shows the principal part of an optical connector same as the above.

Explanation of symbols

P, P 'Optical fibers S1, S2 Space C Butting connection 1 Optical connector 2 Ferrule 2A Fiber hole 2B Guide fiber hole 3 Bushing 3A Guide fiber hole 3B Locking part 4 Holding member 4A Tapered fiber hole 4B Stop protrusion 4C Fitting hole 5 Frame 5A Engaging claw piece 5B Inner protrusion 5C Lock member insertion hole 6 Knob 7 Chuck 7A Tapered surface 7B Horizontal bottom surface 7C Protrusion 7D Notch 8 Recess 8A Bottom surface 8B Front end 8C Rear end 9 Fitting Hole 9A Tapered inner surface 9B Horizontal upper inner surface 9C Horizontal lower inner surface 10 Elastic member 11 Lock member 12 Lock plate 13 Forked leg portion 13a Tapered portion 14 Groove portion 15 Slit portion 16 Holder 21 Cable clamp unit 22 Optical fiber through hole 23 Covering groove 24 Holding bracket 25 Body 26 Lid 27 Boot Q Outer jacket

Claims (2)

A ferrule that has a fiber hole having both ends opened in the axial direction and a bottom surface that reaches the fiber hole on the side where the abutting connection portion of the optical fiber to be inserted is located is provided with a horizontal recess, and an abutting connection portion the fitted into the recess so to press the lower surface side, has a tapered surface from the front to the upper surface side toward the rear, a chuck formed in the horizontal bottom surface corresponding to the lower surface to the bottom surface of the recess of the ferrule chuck taper has a tapered inner surface to the front upper wall to slide in close contact from the outside surface, the rear upper wall and fitting holes each having a parallel horizontal inner surface in the longitudinal subordinates wall formed at the front end portion, and the fiber holes of the ferrule A bush formed with a guide fiber hole that communicates coaxially and a fitting hole that fits into the bush from the outside are formed at the front end portion, and a tapered fiber that communicates coaxially with the guide fiber hole of the bush. Bar hole is formed in the rear end portion, a holding member of the cable clamp unit and can be mounted on the rear end portion, and the bush is interposed while pressing urged forward between the front portion and the bushing front end portion of the holding member By inserting the elastic member into the insertion hole of the frame, the bush is pressed against the pressing elastic force of the elastic member, and the taper surface of the chuck and the taper inner surface of the bush are released from each other. In the optical connector provided with a lock member that causes the pressure expansion elastic force of the elastic member to work by detaching and urging and moving the bush toward the ferrule side so that the taper surface of the chuck and the taper inner surface of the bush are in close contact with each other .
A field assembly optical connector characterized in that a protrusion is provided on the rear surface of the lower surface of the chuck so as to abut against the bottom surface of the concave portion of the ferrule so that the rear end of the chuck can be held at a required upper position.   2. The field assembly optical connector according to claim 1, wherein a total of two protrusions are provided on both sides of a fiber hole provided in the center of the bottom of the ferrule recess.

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