JPS59160117A - Plug for preventing projection of optical fiber - Google Patents

Abstract

PURPOSE:To enable maintaining flush the end faces of a fiber core and an aligning plug at all times and to stabilize the coupling efficiency of the optical fiber and a photoelectric element by providing a fixing plug and an aligning plug adhered and fixed with the fiber core and combining relatively movably the two plugs. CONSTITUTION:An aligning plug 5 fixed with a fiber core 26 and a fixing plug 4 fixed with the 2nd sheath 29 and a reinforcing material 28 are combined via an elastic ring 6. Even if there is a change in temp., the plug 5 is immobile, and the core 26 does not project from the end face of the plug 5. The sheath 29 and the material 28 can displace freely with each other. If there is a difference in thermal expansion between the sheaths 27, 29 and the fiber core 26, the difference is absorbed by the change in the degree of the deformation of the ring 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber protrusion 1Ijj stopper plug that prevents the tip of an optical fiber from advancing or retracting from the end face of a plaque.

In optical communication systems, optical fiber cables are often used as transmission paths for optical signals.

The optical fiber cable and a charging element such as a light emitting element or a light receiving element must be connected on the transmitting side or receiving side (JIJ), respectively.

In some cases, it may be necessary to connect fiber optic cables to each other.

In order to connect the optical fiber cable and the opto-electronic device or other optical fiber cable, an optical connector of suitable structure is used; in the optical connector, to support the tip of the optical fiber h,
, a plaque is fixed to the tip of the optical fiber.

FIG. 6 is a IIr+r plane view, not showing the state in which the tip of the optical fiber cable is fixed to the plug according to the conventional example.

The optical fiber cable 25 has a fiber core wire 26 made of fiber, glass, plastic, etc. at the center, and a first sheath 27 is provided around the fiber core wire 26. The first sheath 27 is made of nylon, for example.

A reinforcing layer 28 is provided on the outside of the first sheath, and a second sheath 29 is provided on the outermost side.

The second sheath is, for example, a soft polyvinyl chloride sheath.

The plaque 30 is a single elongated circle of brass. In the axial direction, a through hole is bored whose inner diameter becomes narrower from the rear to the front.

A thick fiber coat trace hole 31 is provided at the rear. Subsequently, a first sheath through hole 32 is bored in the intermediate portion.

The second sheath 29 at the tip of the optical fiber cord 25 is peeled off, and the reinforcing material 28 is folded back.

After the first sheath 27 is exposed, a portion is further peeled off to expose the fiber core wire 26.

A fixed amount of adhesive is poured into the through hole 31 of the plaque 30.

Insert the tip of the stripped optical fiber cord into the plug 30 containing the adhesive and insert it into the fiber cord passage hole 31 of the plug 30.
Insert from. Then, before the adhesive has hardened, the rear part 35 of the plug is caulked (to provide an adhesive effect).

If you leave it as is, the adhesive will harden. Fiber core wire 2
6 and the end face of the plug so that they are flush with each other, the end face of the plug is polished. FIG. 6 shows such a state.

Insert the plug 30 into the optical connector [I-γ prevents the plug from coming out forward with the flange 34,
4 from the rear with a spring 1) Press it toward IJ.

Such plugs are already widely used.

This type of integrated plaque had the following drawbacks.

The fiber core R'fJ4 lb is made of quartz, glass, or plastic. The second sheath 29 is often made of vinyl chloride. The first sheath 27 is nylon.

There is a difference in thermal expansion coefficient between the fiber core X126 and the sheath 27.29.

The contact agent mainly acts between the second sheath 29 and the inner wall surface of the plug 30.

Although adhesive Ail is also attached between the first sheath 27 and the inner wall surface of the plug, it is not very strong.

There is almost no adhesive between the fiber core wire 26 and the core accommodating hole 33. The fiber core can move relative to the through hole 33.

The temperature range in which the optical fiber table is used is -40'C ~
The range is 100°C.

Since the sheath 27, 29 and the fiber core wire 26 have different coefficients of thermal expansion, and the plug and sheath are bonded together, the fiber core wire 26 protrudes or retreats from the end face of the plug.

The amount of movement of the fiber core in the axial direction is approximately 0°l Mm. Some are large and can move 0°5 am.

If the fiber core protrudes from or retreats from the plaque end face, it becomes a major cause of power loss when transmitting optical signals.

Further, if the protrusion is large, the element or the end face of the fiber may come into contact and be scratched.

The present invention aims to solve these difficulties.

The plug of the present invention is not composed of one single rigid body like conventional plaques, but is a combination of two plaques t'', 15 pieces that can be moved relative to each other.

The plaque of the present invention consists of a fixing plaque that supports the reinforcing material, the second sheath, and the kufla, and an alignment plug to which a fiber core wire is adhesively fixed, and the alignment plug is attached to the front end of the fixing plaque. , is axially movable and supported by an elastic ring so as to be pushed forward.

Embodiments will be described below with reference to drawings showing examples.

FIG. 1 is a sectional view of a plug and a connector connected together according to an embodiment of the present invention.

FIG. 2 shows a cross-sectional view in an exploded state before joining.

The plaque 1 is fixed to the tip of the optical fiber cord passage 25,
It is inserted into the connector 2 and fixed with a cap 3.

The plug 1 includes a fixing plaque 4 at the rear that supports the second sheath 29 and the reinforcing material 28, an alignment plaque 5 that supports the fiber core 26 at the front, and an alignment plaque 5 that supports the fiber core 26 at the front. It consists of an elastic ring 6 that presses forward against the fixing plaque 4.

FIG. 3 is a perspective view showing the state of the fixing plug 4 before it is caulked.

The fixing plaque 4 has a cylindrical shape, and a second sheath passage hole 7 is bored from the rear side. A small portion of the front end is an alignment plaque through hole 8 with a narrower inner diameter.

Fixing plug 4. A flange portion 9 is formed at the rear edge of the flange. This is because it comes into contact with the end surface of the connector 2 and is fixed by the cap 3.

Two kite grooves 10, upper and lower, are cut along the cylindrical generatrix from the rear end of the fixing plug 4 to the front. The kite groove 10 ends at the north side 11 of the protrusion, leaving a small portion at the front.

The fixing plaque 4 is made of metal or plastic. The fixing plug may have to be caulked in the middle, so if it is caulked, it is better to use metal. In the case of plastic, use a separate metal caulking ring.

FIG. 4 is a perspective view of the alignment plug 5.

The alignment plug 5 has a cylindrical shape. At the rear end, there are two upper and lower locks and a protrusion 12 for preventing rotation. The retaining protrusion 12 is a fixing bracket with a diameter of F11″η10.
fit loosely into

The Wl core plug 5 is provided with a through hole or two stages of holes in the axial direction.

A thick first sheath through hole 13 is bored a short distance from the rear end surface, and a thin core wire through hole 14 is formed forward of this.

FIG. 5 is a perspective view of the elastic ring 6.

This has a simple cylindrical shape and uses a rubber ring or the like.

The procedure for attaching the optical fiber cable 25 and the plug 1 is as follows.

A second sheath 29- at the tip of the optical fiber cable 25.

A portion of the first sheath 27 is peeled off.

The alignment plug 5 is passed through the elastic ring 6 in advance, the first sheath 27 of the optical fiber cable 25, and the fiber core wire 26.
Glue to.

Fiber core? J2G and alignment plug 5 are fixed,
The core wire 26 does not move in the axial direction.

1. Insert the core plug 5 from the rear of the fixing plaque 4. The retaining protrusion 12 enters the guide groove 10 of the fixing plug 4.

The retaining protrusion 12 or the protrusion north side 1 on the front of the fixing plug 4
1, the optical fine cable reinforcement 28 and second sheath 29 are fixed to the fixing plug 4.

For example, the fixing mechanism can be implemented by applying adhesive 15 to t=J between the second sheath 29, the reinforcing material 28, and the inner surface of the fixing plug 4.
This is done by gluing the two together.

Instead of the adhesive 15, the second sheath 29 and the reinforcing material 28 may be fixed by caulking the middle of the fixing plug 4. If it is a metal plaque, the clinching portion 1G is directly formed to hold down the second sheath 29. If it is a plastic plug, a metal fastening ring (not shown) may be subjected to f4 and plastically deformed.

There is no problem in using both adhesion and caulking.

Since the fixing plaque 4 does not have an alignment function, it does not matter if the outer surface of the plaque is deformed. Therefore, it is possible.

The connector supports a light emitting device or a light receiving device or other fiber optic cable, and when the plaque of the present invention is inserted,
It efficiently couples an optical fiber cable and a photoelectric device or optical fiber.

The connector 2 shown in FIGS. 1 and 2 has a photoelectric element 1°γ
An example with built-in is shown below.

The photoelectric element 17 is a light receiving element such as a photodiode or an avalanche photodiode, or a light emitting element such as a light emitting diode or a laser diode.

The connector 2 has a cylindrical shape, and is provided with a through hole whose inner diameter changes stepwise in the axial direction.

The through holes are, in order from the side facing the plug, a fixed plug through hole 18, a smaller diameter 1:i core plug through hole 19, a small diameter and short communication hole 20, and an element storage for storing an element. It is room 21.

The entire fixed plug 4 fits into the fixed plug through hole 18.

The iy core plug through hole 19 is L) 4 of the alignment plug 5.
The g part fits in correctly.

The outer periphery of the aligning plaque 5 and A'! Plaque through hole 1 for 1 core
The inner circumference of 9 must be finished with high precision.

The connecting hole 20 is located between the optical fiber core 26 and the photoelectric element 17, where the optical signal is propagated through the air. The length is approximately 0°lman to 065mm.

In order to support the tip of the aligning plaque 5 by the step=lS 22, only the connecting hole 20 remains. If the first alignment plug 5 can be pressed directly against the photoelectric element 17, the communication hole 2u will not be formed.

The outer periphery of the connector 2 is provided with one or more locking claws 23.

The cap 3 is inserted into the optical fiber cable 25 before the plug 1 is inserted.

The cap 3 fixes the plug 1 inside the connector 2 by engaging with the connector 2.

There is a locking hole 24 in the side wall of the cap 3, and the connector 2
It fits into the locking claw 23 of.

The flange portion 9 of the fixing plug 4 is held between the end surface of the connector 2 and the inward side of the cap 3.

The alignment plug 5 is inserted into the alignment plug through hole 19, but the length of the alignment plug through hole 19 is slightly short, and the alignment plug 5 is pushed backward. The elastic ring 6 is compressed.

The alignment plug 5 is pressed toward the photoelectric element 17 by the elastic force of the elastic ring 6 .

In addition to those with built-in photoelectric elements, connectors can also be used with other optical fibers,
It can be applied in the same way even if it has a built-in IVA cable.

The plug 1 and the cap 3 may be integrated in advance.

When the plug 1 and the camp 3 are separate bodies, the connector 2 and the cap 3 may be connected with a screw. That is, a male thread is cut on the outside 11ij of the connector 2, and the cap 3 is made into a cap.

Describe the effects.

A 71rB core plug to which a fiber core wire is fixed, and a fixing plaque to which a second sheath and reinforcing material are fixed are combined via an elastic ring. Even if there is a temperature change, the alignment plug 5 does not move. The fiber core wire does not protrude beyond the end face of the alignment plug 5.

The first sheath 27, the second sheath 29, and the reinforcing member 28 can be freely displaced relative to each other.

Even if there is a difference in thermal expansion between the sheath and the fiber core, this difference can be absorbed by changing the degree of deformation of the elastic ring.

The key is to always keep the fiber core wire and the end face of the alignment plug flush, so that the coupling efficiency between the optical fiber and the photoelectric element does not fluctuate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a state in which a plaque, an optical fiber cable, and a connector are connected according to an embodiment of the present invention. FIG. 2 is a sectional view showing a disassembled state of the plug, connector, and cap according to the embodiment before they are combined. FIG. 3 is a perspective view of the fixing plug. FIG. 4 is a perspective view of the alignment plug. FIG. 5 is a perspective view of the elastic ring. FIG. 6 is a cross-sectional view of a conventional plug and optical 7 AIHA cable in a fixed state. 1 ・・・ ・・・ ・・・ pla
2 ・・・ ・・・ ・ Connector 3 ・・・ ・・
・ ・・・ Gap 4 ・・・
・・・・・・ Fixing plaque 5 ・・・・・・・・・
Alignment plaque 6 ...... Elastic ring 7 ...... Second sheath through hole 8 ・
・・・・・・・・・ Alignment plug through hole 9 ・・・・・・
.../Flange portion 10 ... Guide groove 11 ... Protrusion stop edge 12 ... Retaining protrusion 13 ... First sheath through hole 14・・・・・・
... Core wire through hole - 15 ... Adhesive 16 ... ... Caulking part 17
・・・・・・ Photoelectric element 18 ・
・・・・・・ Fixed plug through hole 19 ・・・・・・
Alignment plug through hole 21...Element storage chamber 23...Locking claw 24
...... Locking hole 25 ...
... Optical fiber cable 26 ... Fiber core wire 27 ... First sheath 28 ... Reinforcement 29 ...
...Second C.S.

Claims (1)

[Claims] It consists of a fixing plug that fixes the sleeve of the optical fiber cable and the second sheath, and an alignment plug that fixes the fiber core, and the alignment plug is attached to the front end of the fixing plug and is movable in the axial direction. An optical fiber protrusion prevention device [L plaque] characterized by being supported so as to be pushed forward by an elastic ring.