JPH0423214Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical fiber terminal structure of an optical fiber connector in optical communication equipment, such as an optical data link.

[Prior art]

FIG. 5 shows a schematic structure of an optical connector, in which 11 is a plug and 12 is a module equipped with a receptacle 12'. This module 12 consists of a receptacle 12', internal elements 17 and 18, and electronic circuitry connected thereto. The optical fiber cords 13 and 14 are connected to other equipment separately or collectively, and have their ends connected to the plug 11. That is, the tips of the optical fiber cords 13 and 14 are exposed from the coating, and cylindrical metal ferrules 15 and 1 are used to protect these exposed parts.
The ferrules 15, 15 protrude an appropriate length from the casing portion 16 of the plug 11, which restrains and holds the optical fiber cords 13, 14 or the proximal ends of the ferrules 15, 15.

The module 12 includes a photo/electric conversion element 17 and an electric/electric conversion element 17.
A light conversion element 18 is installed and held inside, and these elements 17 and 18 are connected to a receiving side circuit and a transmitting side circuit, respectively, which are not shown. Elements 17, 18
Cylindrical members 19, 19 into which the ferrules 15, 15 are to be fitted are arranged concentrically with the elements 17, 18, respectively, on the front side thereof. The cylindrical members 19, 19 are open at the distal end surface of the casing 20 of the receptacle 12'.

The optical fiber was fixed in the ferrule 15 as follows. The ferrule 15, which has a stepped cylindrical shape in FIG. 6, has two slotted portions 15a, 15a at its base end, and the outer diameter of the distal end portion protruding from the casing portion 16 (see FIG. 5). has a small diameter, and the optical fiber cord 1
The jacket 10a of the core wires 10 in 3 and 14 is peeled off to form an optical fiber (core part and cladding part) 10b.
The buffer layer 10c covered with the ferrule 10c is exposed and inserted up to the tip of the ferrule 15. Then, the state in which the optical fiber core wire 10 is inserted (the sixth
), the press-fit ring 2 is fitted onto the ferrule 15.
1 is press-fitted in the direction of the base end of the ferrule 15 (in the direction of the white arrow in FIG. 6) until it abuts on the flange 15b formed at the base end of the ferrule 15, the slotted portions 15a, 15a disappear, and the ferrule 15 is removed. The inner diameter of the jacket 10a is reduced, and the jacket 10a is caulked.
The optical fiber core wire 10 was crimped and fixed in the ferrule 15 by the pressing force of the press-fit ring 21 (7th
figure).

[Problem that the invention attempts to solve]

When the optical fiber having the terminal structure as described above is caulked and fixed, the ferrule 15 only bites into the jacket 10a, so that slippage occurs between the jacket 10a and the buffer layer 10c, causing the optical fiber 10b covered with the buffer layer 10c to slip. There were disadvantages in that protrusion occurred and the caulking was insufficient.

[Means for solving problems]

The present invention was developed in view of the above circumstances, and its purpose is to appropriately peel off the jacket and buffer layer from one end of the optical fiber core to expose the buffer layer and optical fiber to an appropriate length. By inserting the optical fiber end into the ferrule and fixing the optical fiber core with a press-fit ring, both the jacket and the buffer layer are pressed, and the jacket is pressed to give it mechanical strength. It is an object of the present invention to provide an optical fiber terminal structure as described above, in which protrusion of the optical fiber is eliminated by pressing the buffer layer, and the caulking and fixation are sufficient.

The terminal structure of the optical fiber according to the present invention has a slotted part at the base end of an optical fiber cord consisting of a coating, a jacket, a buffer layer, and an optical fiber (core part and cladding part), where the coating is exposed. This proximal end has a larger diameter than the distal end and is inserted into a ferrule with a tapered middle part, and a press-fit ring with an inner diameter larger than the outer diameter of the distal end of the ferrule and smaller than the outer diameter of the proximal end is inserted into the ferrule. In an optical fiber terminal structure of an optical fiber connector in which the ferrule is crimped by fitting outward from the distal end side to the proximal end, the length of the portion of the jacket inserted into the ferrule is shorter than the length of the slotted portion. , a part of the jacket and a part of the buffer layer are pressed at the time of pressing and fixing, and the buffer layer is pressed against the optical fiber.

[Effect]

In the optical fiber terminal structure according to the present invention, the ferrule presses the jacket and the buffer layer, so the jacket pressing part has mechanical strength, and the buffer layer pressing part fixes the optical fiber, so caulking is completely achieved. It is.

〔Example〕

The present invention will be explained below based on drawings showing embodiments thereof. In FIG. 5 showing the schematic structure of an optical connector, optical fiber cords 13 and 14 are connected to a plug 11.
Inside, the tip is exposed from the vinyl coating, and this exposed part is attached to the ferrule 15,1.
5 is fitted and fixed inside.

FIG. 1 is a half-cut sectional view of the end of the optical fiber, showing the end structure of the optical fiber fitted into the ferrules 15, 15. FIG. The optical fiber core 1 has a jacket 1a and a buffer layer 1c at one end thereof.
The optical fibers (core portion and cladding portion) 1b and buffer layer 1c are each exposed to appropriate lengths. These exposed lengths are determined according to the internal structure of the ferrule 5, which will be described later.

Next, regarding the caulking and fixing when using the optical fiber terminal structure according to the present invention, we will explain the details based on FIGS. 2 and 3 showing the state, and FIG. Explain.

In FIG. 2, the stepped cylindrical ferrule 5 has two slotted portions 5a, 5a spaced apart by 180° in the circumferential direction at its base end, and the outer diameter of the ferrule 5 is the same as that of the casing portion 16 (the fifth The distal portion protruding from the (see figure) has a small diameter, the proximal portion has a large diameter, and the middle portion has an intermediate diameter. A taper 5c is formed at the boundary, and a flange 5b is formed at the base end. The slotted portions 5a, 5a are formed from the base end of the ferrule 5 to the position where the taper 5c is formed. The inner diameter is small at the tip, medium at the middle, and thick at the base, and is approximately equal to the diameter of the optical fiber 1b, the outer diameter of the buffer layer 1c, and the outer diameter of the jacket 1a, respectively. Further, a cylindrical press-fit ring 2 whose inner diameter is approximately equal to the outer diameter of the middle part of the ferrule 5 is attached to the ferrule 5.
It is used to fit onto the ferrule 5 from the tip end side.

Then, the jacket 1a and the buffer layer 1c at the ends of the optical fibers 1 in the optical fiber cords 13 and 14 (see FIG. 5) are peeled off as appropriate from the proximal end side of the ferrule 5, and the buffer layer 1c is removed as shown in FIG. 1c and the optical fiber 1b are exposed to an appropriate length, and inserted into the ferrule 5, and the optical fiber core 1 is positioned so that the tip of the optical fiber 1b slightly protrudes from the tip surface of the ferrule 5 (Fig. 2). . The exposed length here is a little longer than the length of the tip of the ferrule where the optical fiber 1b has a small inner diameter, and the length of the buffer layer 1c is approximately equal to the length of the middle part of the ferrule where the inner diameter is intermediate.

Next, the optical fiber core 1 is inserted (second
), fit the press-fit ring 2 onto the ferrule 5 from the distal end side of the ferrule 5, and taper the taper 5c toward the proximal end of the ferrule 5 (in the direction of the white arrow in FIG. 2).
The optical fiber core 1 is press-fitted until it passes through the flange 5b and comes into contact with the flange 5b, the slotted parts 5a and 5a disappear, the inner diameter of the ferrule 5 is reduced, and the jacket 1a and the buffer layer 1c are caulked to attach the optical fiber core 1 to the ferrule 5. It is crimped and fixed inside by the pressing force of the press-fit ring 2. Finally, the portion of the optical fiber 1b protruding from the tip of the ferrule 5 is cut to form an end face (FIG. 3).

In this embodiment, both the jacket 1a and the buffer layer 1c are pressed, so that there is no slippage and the caulking is sufficient.

Note that if a hole having a diameter larger than the gap between the slotted parts 5a, 5a is formed at one end of the slotted parts 5a, 5a of the ferrule 5, the caulking condition will be further improved.

〔effect〕

As described in detail above, in the optical fiber terminal structure according to the present invention, the diameter of the proximal end portion having the slotted portion is larger than that of the distal end portion, and the ferrule with the tapered intermediate portion is used as the optical fiber cord. Insert a press-fit ring into the exposed part of the ferrule, and insert a press-fit ring whose inner diameter is larger than the outer diameter of the distal end of the ferrule and smaller than the outer diameter of its proximal end from the distal end of the ferrule, through the taper in the middle, and into the proximal end. Since the press-fit ring is externally fitted to the ferrule, the work of externally fitting the press-fit ring to the ferrule can be done smoothly and quickly, resulting in excellent workability. Since the ferrule bites into the jacket indirectly, it has mechanical strength at the jacket pressing part, and the optical fiber is fixed at the buffer layer pressing part, preventing slippage between the jacket and the buffer layer and between the buffer layer and the optical fiber. There is no protrusion of the optical fiber, and the caulking and fixation are sufficient.

[Brief explanation of drawings]

Fig. 1 is a half-cut sectional view of the end of the optical fiber showing the terminal structure of the optical fiber according to the present invention, and Fig. 2 is a half-cut sectional view showing the state before caulking and fixing with the terminal structure of the optical fiber according to the present invention. , Fig. 3 is a half-cut sectional view showing the state in which it is fixed by caulking, Fig. 4 is a sectional view taken along the - line in Fig. 2, Fig. 5 is a schematic structural diagram of the optical connector, and Fig. 6 is a conventional terminal structure. FIG. 7 is a half-cut sectional view showing a state before the optical fiber is caulked and fixed, and FIG. 7 is a half-cut sectional view showing the same state after caulking and fixing. 1... Optical fiber core wire, 1a... Jacket,
1b...Optical fiber (core part and clad part),
1c...buffer layer, 2...press-fit ring, 5...
Ferrule, 5a...slotted part.

Claims (1)

[Scope of Claim for Utility Model Registration] An optical fiber cord consisting of a coating, a jacket, a buffer layer, and an optical fiber (core part and cladding part) has a slotted part at the base end of the part where the coating is exposed, This proximal end has a larger diameter than the distal end and is inserted into a ferrule with a tapered middle part, and the inner diameter is larger than the outer diameter of the distal end of the ferrule.
In an optical fiber terminal structure of an optical fiber connector in which the ferrule is crimped by fitting a press-fit ring smaller than the outer diameter of the proximal end from the distal end side of the ferrule to the proximal end thereof, the part to be inserted into the ferrule of the jacket. The length of the optical fiber is shorter than the length of the slotted portion, and when the jacket is pressed and fixed, a part of the jacket and a part of the buffer layer are pressed, and the buffer layer is pressed against the optical fiber. terminal structure.