JP2920817B2 - Optical connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector for detachably connecting a pair of optical fibers, and more particularly to an optical connector suitable for connecting an optical fiber having a relatively small diameter.

[0002]

2. Description of the Related Art An optical connector for detachably connecting optical fibers to each other is required to make the core end faces of the optical fibers exactly coincide with each other as in the case of fusion splicing the optical fibers. .

[0003] In response to this demand, an optical connector using a ferrule has conventionally been used. FIG. 5 is a longitudinal sectional view showing an optical connector using a conventional ferrule. In FIG. 5, the optical connector includes a distal end portion 71 and a base portion 72 into which the distal end portion 71 is press-fitted. A ferrule 70 to which the optical fiber F is attached, a plug 60 for housing the ferrule 70, and a pair of plugs 60 And an adapter 50 connected from the other side. More specifically,
It looks like this: An optical fiber F whose core wire is exposed by removing the coating by an amount substantially corresponding to the length of the tip portion 71
(In FIG. 5, the coating and the core wire are not distinguished.) Is inserted into the ferrule 70 and fixed, and then the end surface of the tip portion 71 is polished. Then, after attaching the spring 61 to this, it is housed in the cylindrical plug 60, and the assembly including the plug 60 is completed. On the other hand, the adapter 50 has a sleeve 51 as a ferrule receiving portion for receiving the ferrule 70 therein. Then, the plug 60 is inserted into the adapter 50 and the sleeve 51 is
1 of ferrule 70 inserted from both ends
End faces are connected to each other.

The ferrule 70 has a tip 71 made of, for example, zirconia having a diameter of 2.5 mm.
And the front end portion 71 is made up of the press-fitted base portion 72, so that the rigidity is high. For this reason, when the ferrule 70 is inserted into the sleeve 51, due to dimensional variations of the components constituting the optical connector,
Even if a load is applied to the ferrule 70 and the optical fiber F due to the end face of the tip portion 71 of the ferrule 70 hitting the end face of the sleeve 51 or the like, since the ferrule 70 has high rigidity, the ferrule 70 is inserted into the sleeve 51 without breaking. What is connected.

[0005] As described above, the conventional optical connector includes:
Since the ferrule 70 having a high rigidity is connected in the sleeve 51, there is almost no fear of the ferrule 70 being broken at the time of fitting connection.

[0006]

By the way, optical connectors are required to be small, multi-core, and high-density, and a ferrule having a smaller diameter than conventional ferrules is required. In the case of connecting such a small-diameter ferrule, it is necessary to consider the breakage of the ferrule at the time of fitting. That is, a diameter of 2.5 mm and a length of 8 mm
Ferrules made of zirconia will not break unless a load of several tens of kilograms is applied, but a ferrule with a small diameter of 0.5 mm in diameter, which is also 8 mm long and made of zirconia, will only break when a load of several hundred g is applied. There is a problem.

As optical connectors have become smaller, multi-core, and higher in density, each part of the optical connector has become smaller, and the ferrule 7 has a smaller size.
Accidents such as the end surface of the leading end portion 71 colliding with the end surface of the sleeve 51 and the like easily occur, and the problem of ferrule breakage becomes more prominent.

An object of the present invention is to provide an optical connector in which a ferrule having a small diameter is not likely to break.

Another object of the present invention is to provide an optical connector which is reduced in size, multi-core, and has a higher density.

[0010]

According to the present invention, there is provided an adapter having a tubular shape, and a plug inserted from a mouth portion of the adapter, wherein the plug has an optical fiber extending in the insertion direction. A ferrule for holding an optical fiber at the distal end side, and the adapter is adapted to receive each of the ferrules such that the end faces of the ferrules of the two plugs inserted from the two cylindrical openings are in contact with each other. In the optical connector having a receiving portion, the ferrule receiving portion has a plate shape, and has a V-shaped groove formed on an upper surface thereof, the V-shaped groove extending in the insertion direction and capable of receiving the ferrule. A guide groove portion having a displacement groove surface extending downwardly and displacing downward from the cylinder mouth toward the vicinity of the ferrule receiving portion; Includes a slidable guide projection to of said guide groove when said plug is inserted into the adapter, the said ferrule of said ferrule receiving portion by which the plug is displaced towards the lower V
An optical connector characterized by being arranged so as to be placed on the U-shaped groove from above is obtained. In addition, the plug includes a guide groove having a displacement groove surface that extends in the insertion direction and is displaced upward while moving from the distal end side to the rear end side. An optical connector having a provided structure is also obtained.

According to the present invention, the adapter further comprises:
The optical connector includes a pressing spring for pressing the ferrule from above toward the V-shaped groove of the ferrule receiving portion.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical connector according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a use state of the optical connector according to the present embodiment, and FIG. 2 is a perspective view showing a state where two plugs are removed from the optical connector of FIG.

1 and 2, the present optical connector has an adapter 10 having a rectangular tubular shape, and two plugs 20 inserted from the cylindrical openings 11a and 11b of the adapter 10, respectively. The distal end of the plug 20 is inserted and fitted into the tube openings 11a and 11b of the adapter 10, and is set to have a slightly smaller opening size than the tube openings 11a and 11b.

The plug 20 is inserted into the optical fiber F such that the core of the optical fiber F from which the coating is peeled extends in the insertion direction.
A ferrule 21 for holding the core wire is provided on the distal end side. At the rear end of the plug 20, a keeper 30 for holding a portion covered with the optical fiber F is attached.

As will be described in detail later, the adapter 10 has two ferrules 21 (only one of which is shown in FIG. 2) of two plugs 10 inserted through the two cylindrical openings 11a and 11b. A ferrule receiving portion that receives each ferrule 21 so as to be in contact therewith is provided. In this embodiment, four pairs of optical fibers having a relatively small diameter are detachably connected to each other.

FIGS. 3A to 3D are longitudinal sectional views for explaining a connection process between the adapter 10 and the plug 20 in the optical connector according to the present embodiment. In addition, FIG.
In (d), only one plug 20 is shown without an optical fiber in order to avoid complexity of illustration. FIGS. 4A and 4B are a cross-sectional view and a vertical cross-sectional view, respectively, showing a state in which the connection between the adapter 10 and the two plugs 20 to which optical fibers are connected is completed.

First, referring to FIG. 3 (a), the adapter 10 has two plugs 10 (only one of which is shown) inserted into the two cylindrical openings 11a and 11b. A ferrule receiving plate 14 that receives each ferrule 21 so as to abut is provided at the center of the cylinder. The ferrule receiving plate 14 has a V-shaped groove 141 extending on the upper surface thereof in the insertion direction of the plug 20 (the left-right direction in the figure) and capable of receiving the ferrule 21 in a number corresponding to the number of optical fiber pairs (in this embodiment, (Four). In addition, it is preferable that the top of the protrusion on the ferrule receiving plate 14 constituting the groove surface of the V-shaped groove 141 is not a horizontal surface or a concave surface but a tapered or R-shaped convex surface. This is, as described later, the ferrule 21
When the ferrule 21 is arranged so as to be placed from above, even if the ferrule 21 is bent left and right, it is to prevent the ferrule 21 from hitting a horizontal surface or a concave surface.

The adapter 10 also has a displacement groove surface that extends in the insertion direction of the plug 20 and that is displaced downward while moving from the tube opening 11a or 11b to the center of the tube near the receiving plate 14. Guide grooves 12 and 13 are provided. When the plug 20 is inserted into the adapter 10, the guide grooves 12 and 13 hold the ferrule 2 of the plug 20.
The V-shaped groove 14 is formed on the ferrule receiving plate 14 in the insertion direction along the plug 20 (the direction perpendicular to the plane of the drawing).
It extends parallel to 1.

Further, the adapter 10 includes a ferrule 21
Of the ferrule receiving plate 14 is pressed against the V-shaped groove 141 of the ferrule receiving plate 14 from above. The pressing spring 15 is not limited to the illustrated example.
A shape or the like in which each of the 0 cylindrical mouth portions 11a and 11b is integrated may be used.

On the other hand, the plug 20 has guide projections 22 and 23 of a position, a shape and a size slidable in the guide grooves 12 and 13 of the adapter 10. The ferrule 21 of the plug 20 includes a cylindrical distal end portion for accommodating a core wire of an optical fiber (not shown) and a base portion that engages with a spring described later.
0 is slightly protruded from the front end side, and the front end face is chamfered. The plug 20 is provided with a spring 24 for pressing the ferrule 21 toward the distal end of the plug 20.

In the present embodiment, the guide grooves 12 and 13 having displacement groove surfaces are provided on the adapter 10, while the guide projections 22 and 23 are provided on the plug 20, but in the present invention, the ferrule is It is sufficient that the entire plug having the structure is displaced toward the ferrule receiving portion at the time of insertion. The guide groove may be provided on the outer surface of the plug, and the guide protrusion slidable in the guide groove may be provided on the inner side surface of the adapter.

Next, FIGS. 3A to 3D and FIG.
With reference to (a) and (b), the optical connector according to the present embodiment will be described in more detail according to the connection process between the adapter 10 and the plug 20.

Now, from the state shown in FIG.
As shown in (b), the plug 20 is inserted into the cylindrical opening 11a of the adapter 10. At this time, the guide projections 22 and 23 of the plug 20 slide in the guide grooves 12 and 13 of the adapter 10. Also, the ferrule 21 of the plug 20
Is located higher than the receiving plate portion 14 of the adapter 10.

When the plug 20 is further pushed in, FIG.
As shown in FIG.
In accordance with the displacement groove surfaces of the guide grooves 12 and 13 at 0, it is displaced downward. Thereby, the plug 20
The whole is displaced downward, and the ferrule 21 provided on the plug 20 also approaches the V-shaped groove 141 of the ferrule receiving plate 14, descends horizontally to the V-shaped groove 141, and is placed in the V-shaped groove 141. It is arranged to be placed.
At this time, the tip of the ferrule 21 of the plug 20 contacts the pressing spring 15.

When the plug 20 is further pushed in, FIG.
As shown in FIG. 7, the ferrule 21 advances in the V-shaped groove 141 while being pressed from above by the pressing spring 15 toward the V-shaped groove 141 of the ferrule receiving plate 14.
Therefore, the vertical position of the ferrule 21 is accurately defined. Further, when the other plug 20 (not shown) is inserted, one ferrule 21 does not ride on the other ferrule 21.

3 (a) to 3 (d), the plug 20 is inserted from the left cylindrical opening 11a of the adapter 10, but the plug 20 is similarly inserted from the right cylindrical opening 11b of the adapter 10. 4 (a) and 4 (b). That is, in the V-shaped groove 141 of the ferrule receiving plate 14, the end faces of the ferrules 21 of the pair of plugs 20 are pressed by the respective springs 24 and abut, and the optical fibers (not shown) are connected. FIG.
In (a) and (b), a keeper 30 for holding the coated portions of the four optical fibers F is attached to the rear ends of the two plugs 20.

As described above, the connection process of the optical connector according to one embodiment of the present invention has been completed. The optical connector according to the present embodiment is of the type in which the ferrule 21 is disposed in the V-shaped groove 141 such that the ferrule 21 is placed from above the ferrule receiving plate 14 as is apparent from the description of FIG. There is no fear of an accident such as the tip of the ferrule 21 hitting the flat side surface of the ferrule receiving plate 14, and even if each part of the optical connector including the ferrule 21 becomes small,
An optical fiber having a small diameter does not break.

[0029]

According to the optical connector of the present invention, the ferrule receiving portion has a plate-like shape and has a V-shaped groove formed on the upper surface thereof so as to extend in the insertion direction to receive the ferrule, and the adapter extends in the plug insertion direction. A guide groove having a displacement groove surface that is displaced downward from the cylinder mouth toward the vicinity of the ferrule receiving portion; a guide protrusion that allows the plug to slide in the guide groove; When the ferrule is inserted into the ferrule, the plug is displaced downward so that the ferrule is placed in the V-shaped groove of the ferrule receiving portion from above, so that no excessive force acts on the ferrule. There is no fear that the ferrule having a small diameter is broken. Therefore, miniaturization, multi-core, and high density can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a use state of an optical connector according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state where two plugs are removed from the optical connector shown in FIG. 1;

FIG. 3 is a longitudinal sectional view for explaining a connection process between an adapter and a plug in the optical connector shown in FIG. 1;
(A) is a state before insertion, (b) is a state immediately after the start of insertion,
(C) shows a state during insertion, and (d) shows a state when insertion is completed.

FIG. 4 is a diagram showing a state in which connection between the adapter and two plugs in the optical connector shown in FIG. 1 has been completed;
(A) is a transverse sectional view, (b) is a longitudinal sectional view.

FIG. 5 is a longitudinal sectional view showing an optical connector according to a conventional example.

[Explanation of symbols]

 10, 50 Adapter 11a, 11b Tube opening 12, 13 Guide groove 14 Ferrule receiving plate 15 Pressing spring 20, 60 Plug 21, 70 Ferrule 22, 23 Guide projection 24 Spring 30 Keeper 51 Sleeve 61 Spring 71 Tip 72 Base 141 V F-shaped groove F Optical fiber

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasuhiro Ando 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-61-252510 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B ^6/ 36-6/40

Claims (3)

(57) [Claims] 1. An adapter having a cylindrical shape, and a plug inserted from a cylindrical opening of the adapter, wherein the plug has a ferrule holding an optical fiber such that the optical fiber extends in a direction of insertion. In the optical connector, the adapter is provided with a ferrule receiving portion for receiving each of the ferrules such that end faces of the ferrules of the two plugs inserted from the two cylindrical openings are in contact with each other. The ferrule receiving portion has a plate shape, and has a V-shaped groove formed on the upper surface thereof, which extends in the insertion direction and can receive the ferrule, and the adapter has
A guide groove portion having a displacement groove surface extending in the insertion direction and displacing downward from the cylinder mouth toward the vicinity of the ferrule receiving portion, wherein the plug slides in the guide groove portion A possible guide projection, wherein when the plug is inserted into the adapter, the plug is displaced downward so that the ferrule is placed from above into the V-shaped groove of the ferrule receiving part. Optical connector characterized by being arranged as follows. 2. An adapter having a cylindrical shape, and a plug inserted from a cylindrical opening of the adapter, wherein the plug has a ferrule for holding an optical fiber so that the optical fiber extends in a direction of the insertion. In the optical connector, the adapter is provided with a ferrule receiving portion for receiving each of the ferrules such that end faces of the ferrules of the two plugs inserted from the two cylindrical openings are in contact with each other. The ferrule receiving portion has a plate shape, and has a V-shaped groove formed on the upper surface thereof, which extends in the insertion direction and is capable of receiving the ferrule, and the plug extends in the insertion direction and extends from the front end to the rear end. It has a guide groove with a displacement groove surface that is displaced upward while heading toward
The adapter includes a guide protrusion slidable in the guide groove, and when the plug is inserted into the adapter, the plug is displaced downward so that the ferrule receives the ferrule receiving portion. The optical connector is disposed so as to be mounted on the V-shaped groove portion from above from above. 3. The optical connector according to claim 1, wherein the adapter includes a pressing spring that presses the ferrule from above toward the V-shaped groove of the ferrule receiving portion.