JP2003344704A - Optical connector and assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make fine adjustment in positioning possible in the circumferential direction of an optical connector at the time of connection with an optical connector adaptor and also to suppress an increase in production cost, in the optical connector such as an FC type optical connector. <P>SOLUTION: The annular key ring 31 in which a key 33 is projected for positioning around the axis with an optical connector on the female end of an optical connector adaptor 22 for example is fitted outside a tubular frame 34 for storing a ferrule 8 and rotated around the axis of the frame 34. As a result, positioning and aligning can be performed with high accuracy for the ferrule 8 and the optical fiber 35a that is fixedly inserted in the ferrule 8. In addition, the key ring 31 with the positioning completed by rotation can be easily stuck and fixed to the frame 34 by pouring an adhesive into an injection hole 36 formed in the key 33, in this optical connector 30. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, JIS C
The present invention relates to an optical connector for performing axial positioning when connecting to a receiving optical connector such as an optical connector adapter such as an FC optical connector established in 5970, and an optical connector assembling method.

[0002]

2. Description of the Related Art Conventionally, as this type of optical connector, for example, one having a structure shown in FIG. 3 is known (FIG. 3 shows an example of an FC type optical connector). The optical connector 1 includes a substantially cylindrical frame 2, a sleeve-shaped stopper 3 connected to the frame 2, a boot 4 attached to the stopper 3, and a cup rotatably fitted on the frame 2. It has a ring nut 6, a spring 7 housed in the frame 2, and a ferrule 8 inserted in the frame 2. Further, the stopper 3 holds an optical fiber (not shown) whose tip is housed in the ferrule 8 together with a holding component and a boot 4 incorporated therein, and pulls it out from the optical connector 1 rearward (left side in FIG. 3). The holding unit 5 for preventing the above is configured.

The ferrule 8 is of a columnar shape having a flange portion 9 at the rear end thereof, and four engaging grooves 10 are formed at 90 ° intervals on the outer peripheral surface of the flange portion 9.
These locking grooves 10 are formed so as to be locked by locking ridges 11 projecting inside the frame 2 for positioning when the ferrule 8 is inserted into the frame 2, and will be described later. In performing centering (also referred to as centering), the locking groove 10 is selectively inserted into and engaged with the locking strip 11 so that the ferrule 8 can be positioned around the axis. There is. In addition, the ferrule 8 has a locking strip 1
1 can be moved a little in the axial direction of the frame 2 within a range in which the engagement state between the locking groove 1 and the locking groove 10 is maintained, and when the optical connector 1 is pushed to the rear side, the spring 7 is compressed. The spring 7 generates a butting force between the ferrules that are butted when the optical connector 1 is connected. Further, a stopper (not shown) restricts the ferrule 8 from protruding from the frame 2 to the front of the optical connector 1.

A male screw portion 12 is formed on the outer peripheral surface of the frame 2 on the rear end side thereof, and a female screw portion 13 formed on the rear end side of the coupling nut 6 is formed on the male screw portion 12. It is screwed. Here, the female screw portion 13 is formed on the inner peripheral surface of the protruding portion 14 that protrudes inward on the rear end side of the coupling nut 6. The inner diameter of the coupling nut 6 on the tip side is sufficiently larger than the outer diameter of the frame 2, and the inner peripheral surface of the tip side has an optical connector adapter 2 to be described later.
A female screw portion 15 that is screwed into a male screw portion formed on the outer peripheral surface of the second sleeve portion 22a (see FIG. 5) is formed.

Further, a convex portion 16 is formed on the outer peripheral surface of the frame 2 on the tip side of the male screw portion 12. The convex portion 16 extends along the circumferential direction of the frame 2 and comes into contact with the projecting portion 14 of the coupling nut 6 via a washer 17, whereby the coupling nut 6 is attached to the frame. It is prevented from getting out of 2.

On the outer peripheral surface of the frame 2, a key ring 18 is externally attached and attached to the tip side of the convex portion 16. As shown in FIG. 4, the key ring 18 has a ring-shaped key ring main body 19 which is partially cut out and is discontinuous, and a positioning engagement piece 20 (hereinafter, referred to as a “key”) extending to one side of the key ring main body 19. (Also called a key),
A pair of engagement pieces 21 and 2 extending to the side opposite to the key 20.
1 and a resin or metal. Here, the engagement pieces 21, 21 are 9
It is formed at a position of 0 °.

The key ring 18 having such a structure
The engaging pieces 21 and 21 (not shown in FIG. 3) are fitted to the frame 2 with the engaging pieces 21 and 21 (not shown in FIG. 3) on the convex portion 16 side, so that the key 20 is attached to the tip side of the frame 2. Is aimed at. here,
In the key ring 18, the engagement pieces 21, 21 of the key ring 18 are the frame 2
The frame 2 is positioned in the direction around the axis by engaging with the outer peripheral surface or the engaging portion (not shown) formed on the convex portion 16, and is fixed by an adhesive or the like. In addition, the key 20 that is directed to the tip side of the frame 2
Is the keyway 23 of the optical connector adapter 22 (see FIG. 5).
By engaging with, the optical connector 1 and the optical connector adapter 22 are positioned.

In the optical connector 1 having such a structure, for example, a pair of optical connectors 1 are connected to both sides of a general optical connector adapter 22 as shown in FIG. By butt connection,
Optical connection between the optical fibers of each optical connector 1 can be realized. That is, in order to connect the optical connector 1 to the optical connector adapter 22, the frame 2 of the optical connector 1 and the ferrule 8 are inserted into the sleeve portion 22 a of the optical connector adapter 22, so that the key ring 23 of the optical connector adapter 22 is keyed. The key 20 of 18 is inserted and engaged, and the coupling nut 6 of the optical connector 1 is screwed onto the male screw portion of the sleeve portion 22 a (see FIG. 5) of the optical connector adapter 22. As a result, the ferrules 8 that are positioned and held in the frame 2 of each optical connector 1 that is connected via the optical connector adapter 22 are separated from each other by the optical connector adapter 2.
A positioning mechanism such as a positioning sleeve built in 2 allows precise positioning and butt connection on the same straight line. Further, by engaging the key groove 23 of the optical connector adapter 22 and the key 20 of the key ring 18, the ferrule 8 of each optical connector 1 is positioned around the axis.

By the way, in such an optical connector 1,
The position of the optical fiber (specifically, the core of the optical fiber) inserted and fixed in the ferrule 8 is adjusted in the optical connector 1 (specifically, the position is adjusted with respect to the frame 2) to optimize the connection loss sufficiently. (Aligning) is widely practiced. In this case, the positional relationship between the optical fiber in the ferrule 8 and the frame 2 is checked by, for example, a monitor device, and as a result, the engaging groove 10 of the flange 9 and the frame 2 are engaged with each other as described above. The optical connector 1 is assembled by adopting one of the combinations of engagement with the stopper 11 that minimizes the connection loss between the optical connectors 1 and 1 connected via the optical connector adapter 22. . If the optical connectors 1 thus assembled are connected via the optical connector adapter 22,
The optical fibers inserted into and fixed to the ferrule 8 of each optical connector 1 are butt-connected with each other with low connection loss.

[0010]

However, in the above-mentioned optical connector 1, although the optical fiber in the ferrule 8 and the frame 2 are aligned with each other by the engaging groove 10 of the flange portion 9 ,. Since only four locking grooves 10 are formed at 90 ° intervals, there is a complaint that fine adjustment cannot be performed. In view of this, the present inventors have already proposed an optical connector and a connecting method capable of positioning a key ring externally attached to a frame by rotating the key ring around the axis (Japanese Patent Application No. 2000-216).
580 (JP 2002-31743A). Hereinafter, also referred to as "proposed technology"). In this proposed technique, the position of the optical fiber inserted into and fixed to the ferrule can be finely adjusted because the position can be finely adjusted by rotating the key ring in the axial direction (that is, the circumferential direction of the frame). Yes, the alignment accuracy can be improved.

However, as a result of earnest studies by the present inventors, when assembling the optical connector according to the above-mentioned proposed technique, when the key ring, which has been axially positioned with respect to the frame, is adhesively fixed to the frame with an adhesive. There has been a demand for improving the workability of. For example, for the optical connector according to the proposed technology, if you want to adopt an assembly procedure (assembly method) in which the frame, the coupling nut, the ferrule, etc. are assembled in advance and then the key ring is positioned by rotation with respect to the frame, the adhesive fixing is performed. When the completed key ring is bonded and fixed to the frame with an adhesive, the coupling nut and other members assembled in advance become an obstacle, and it is difficult to secure workability. Also, since the key ring before fixing easily displaces due to external force, under the situation where it is difficult to secure workability as described above, the key ring is inadvertently pushed by the adhesive injection nozzle or the like. Cheap.

The present invention has been made in view of the above circumstances, and its object is to rotate a key ring externally attached to a frame for a receiving side optical connector such as an optical connector adapter around an axis of the frame. This makes it possible to align the optical fiber inserted into the ferrule and the frame with the frame easily and with high accuracy.
An object of the present invention is to provide an optical connector and an assembling method of the optical connector, which can easily bond and fix a key ring whose positioning in the axial direction is completed to a frame.

[0013]

In order to achieve the above-mentioned object, the following solution means are provided. The present invention has a cylindrical frame, a ferrule housed in the frame by restricting rotation about an axis with respect to the frame, and a ring-shaped key ring mounted and fixed on the outer peripheral surface of the frame. Then, while inserting the frame and the ferrule into the cylindrical sleeve portion of the receiving side optical connector such as an optical connector adapter, the key protruding from the key ring is inserted into the key groove of the sleeve portion. In the optical connector that is connected to the receiving side optical connector by positioning the key ring around the axis, the key ring can be positioned by rotating around the axis with respect to the frame by being externally attached to the frame. There is an injection hole penetrating the key for injecting an adhesive for fixing the key ring to the frame. To provide an optical connector which is characterized in that there. Further, according to the present invention, a cylindrical frame, a ferrule housed in the frame by restricting rotation about an axis with respect to the frame, and a ring-shaped key ring mounted and fixed on the outer peripheral surface of the frame. And inserting the frame and the ferrule into a cylindrical sleeve portion of a receiving side optical connector such as an optical connector adapter, and inserting a key protruding from the key ring into a key groove of the sleeve portion. A method of assembling an optical connector, which is axially positioned with respect to the sleeve portion and is connected to the receiving side optical connector, wherein the ferrule is accommodated in a cylindrical frame that regulates rotation around the axis. The extrapolated key ring is positioned by rotation about an axis with respect to the frame and then the injection formed through the key. The adhesive is injected to provide a method of assembling an optical connector which is characterized by adhering and fixing the key ring to the frame by the adhesive.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
FIG. 1 is a view for explaining an embodiment of an optical connector and an assembling method thereof according to the present invention, in which reference numeral 30 is an optical connector. The optical connector 30 is different from the optical connector 1 shown in FIG. 3 mainly in the configuration of the key ring. That is, in the optical connector 30 of the present example, as shown in FIG. 2, the key ring 31 has a discontinuous ring-shaped key ring main body 32 with a part cut away (notch 32 a). The key ring body 32 comprises a key 33 which is a protruding piece extending to one side of the key ring main body 32, and has a configuration in which the pair of engaging pieces 21, 21 of the conventional key ring 18 shown in FIG. 4 are eliminated. There is.
With such a configuration, the key ring 31 is provided in the optical connector 3
When the 0 is assembled, the frame 3 is inserted onto the outer peripheral surface of the frame 34 and rotated about the axis of the frame 34, so that the frame 3
The fixed position with respect to 4 can be positioned. Also, the key ring 31 is attached to the key 33 in the frame 3
An injection hole 36 for injecting an adhesive agent to be fixed to 4 is formed therethrough, and the key ring 34 is positioned by the rotation of the frame 34 around its axis as described above, and then the adhesive agent injected into the injection hole 36 is used. It is adhesively fixed to the frame 34.

The frame 34 on which the key ring 31 is externally inserted has almost the same structure as the frame 2 shown in FIG. 3, except that the key ring 18 shown in FIG. 4 is engaged with the frame 34. The point is that there is no engaging portion (not shown) that engages the pieces 21, 21. However, even if it has this engaging portion, there is no problem in use as long as it is a structure that can realize stable rotation of the key ring 31 around the axis of the frame, and therefore, as the frame 34 of the optical connector 30 of the present invention. It is possible to use.

The optical connector 30 can be connected to the above-mentioned optical connector adapter 22 in the same manner as the conventional optical connector 1. The connection target of the optical connector 30 is not limited to the optical connector adapter 22. For example, various optical connectors such as an optical connector receptacle (receiving side optical connector, including the optical connector adapter 22) can be adopted.

An optical connector adapter 22 is adopted as a receiving side optical connector, and a case of connecting a pair of optical connectors 30 via the optical connector adapter 22 will be described as an example. The sleeve portion is similar to the conventional optical connector 1. 22a
By connecting the optical connectors 30 on both sides of the optical connector 30, the ferrules 8 of the optical connectors 30 are abutted and connected in the optical connector adapter 22, and the optical fibers 35a (optical fiber cords or the like, which are inserted and fixed in the ferrules 8 are connected. An optical fiber is provided at the tip of the optical fiber 35. Here, bare optical fibers are optically connected to each other. However, the positioning of the ferrule 8 of the optical connector 30 about the axis with respect to the ferrule that is butt-connected to the ferrule 8, in other words, the positioning of the optical connector 30 about the axis with respect to the sleeve portion 22a is outside the frame 34. The key 33 of the key ring 31 that has been adhesively fixed to is inserted into and engaged with the key groove 23 of the sleeve portion 22a. In the case of a receiving side optical connector other than the optical connector adapter 22 such as an optical connector receptacle, the key 33 of the key ring 31 of the optical connector 30 is inserted into and engaged with the key groove of the receiving side optical connector side so that the optical connector The configuration in which the ferrule on the receiving side optical connector side and the ferrule 8 on the optical connector 30 side are butted and connected to each other by positioning around the axis of 30 is common to the above-described optical connector adapter 22.

In this optical connector 30, in the assembling process, the alignment of the optical fiber 35a inserted and fixed in the ferrule 8 is aligned with the engagement groove 10 of the flange portion 9 which engages with the engagement line 11 of the frame 34. In addition to the selection, by adjusting the fixed position of the key ring 31 in the axial direction of the frame 34 (in other words, the circumferential direction), high alignment accuracy can be easily obtained, thereby reducing the connection loss. Can be realized.

In assembling the optical connector 30, a method of aligning the optical fiber 35a to reduce the connection loss will be specifically described. First, as in the conventional case, the connection loss is reduced by using a monitor device or the like. In order to do so, a combination of the locking strip 11 of the frame 34 and the locking groove 10 of the flange portion 9 is selected and engaged. Next, the key ring 31 is extrapolated to the frame 34, and the key ring 31
The key ring 31 is rotated around the axis of the frame 34 on the outer peripheral surface of the frame 34 while observing the positional relationship between the key 33 and the optical fiber 35a in the ferrule 8, and the key ring 31 is at the best position where the connection loss can be reduced. To position. When the positioning of the key ring 31 is completed, the injection hole 3
Inject adhesive from 6 and attach key ring 31 to frame 34
Adhesively fixed to.

As described above, the centering of the optical fiber 35a inserted and fixed in the ferrule 8 is selected in addition to the selection of the locking groove 10 of the flange portion 9 which engages with the locking strip 11 of the frame 34, and the frame 34 If the configuration is such that the fixed position of the key ring 31 is adjusted by rotating the optical fiber 35a with respect to the frame 34, the position of the key ring 31 is adjusted by rotating the frame 34 about its axis.
It is possible to finely adjust the position of
As compared with the centering by selecting the combination of 1 and the engagement groove 10 of the flange portion 9, it is possible to easily obtain a high centering accuracy and easily reduce the connection loss.

In this optical connector 30, the ferrule 8,
Even when the frame 34, the coupling nut 6 and the like are assembled and the assembly method of attaching the key ring 31 to the frame 34 in the subsequent work is adopted, the frame 34
The workability of adhering the key ring 31 to the optical connector 30 can be well secured, and the entire optical connector 30 can be efficiently assembled.
That is, when the ferrule 8, the frame 34, the coupling nut 6 and the like are assembled and the key ring 31 is attached to the frame 34 in the subsequent work, for example, the key ring 3 that has completed the axial positioning of the frame 34.
1 and the frame 34 are bonded and fixed by injecting an adhesive agent between the key ring body 32 and the frame 34 from the tip side of the frame 34, the coupling nut 6
Is an obstacle and it is very difficult to inject the adhesive. Further, in the first place, the space between the key ring main body 32 and the frame 34 is very narrow in view of ensuring the positioning accuracy of the key ring 31, and even if an adhesive is injected into such a place, the adhesive hardly enters. , Work takes time.

In the optical connector 30 according to the present invention, an injection hole 36 for injecting an adhesive for adhering and fixing the key ring 31 to the frame 34 is provided from the key ring main body 32 to the optical connector 3.
The key 33 is formed on the key 33 protruding toward the front side of 0 (the insertion tip side with respect to the receiving side optical connector), and the injection hole 36 is formed at a position where the coupling nut 6 is movable in the front-rear direction (the coupling nut 6 is movable). The movable range is the frame 34
The contact position with the convex portion 16 protruding from the front end is the front end, and the contact position with the stopper 3 is the rear end).
The injection hole 36 can be exposed by simply moving it backward. Therefore, in the optical connector 30, the work of injecting the adhesive into the injection hole 36 can be efficiently performed while avoiding the interference with the coupling nut 6 and the like (improvement of the workability of adhesion). Moreover, with such a structure that can improve the bonding workability, it is possible to effectively prevent the inconvenience of accidentally pushing the key ring 31 during the bonding work.

Further, in the key ring 31 exemplified in this embodiment, the ring-shaped key ring main body 32 discontinuous by the notches 32a functions like a spring to enhance sliding friction with the frame 34. Also, the positional displacement of the key ring 31 during the bonding work is effectively prevented.

Further, if the adhesive is injected into the injection hole 36, it can be performed in a short time and easily as compared with the operation of injecting into a narrow region where the key ring body 32 of the key ring 31 and the frame 34 are in contact with each other. Since the injection work can be performed, there is also an advantage that the assembly time of the optical connector 30 can be shortened. For example, a configuration in which a groove that reaches the injection hole 36 from the key ring main body 32 is formed on the inner surface side of the key ring 31 facing the frame 34 side, and the adhesive injected into the injection hole 36 also enters the inner surface of the key ring main body 32. Can also be adopted, which is effective in that the adhesive can be more efficiently injected between the key ring 31 and the frame 34.

With such an optical connector 30 and the assembling method thereof, even when the ferrule 8, the frame 34, the coupling nut 6 and the like are assembled and the key ring 31 is attached to the frame 34 in the subsequent work. , The optical fiber 35 inserted into and fixed to the ferrule 8
The positioning and alignment of a can be performed with high accuracy, and furthermore, the key ring 31 which has completed the positioning around the axis of the frame 34 can be easily fixed to the frame 34 in a short time. The assembly work efficiency of can be improved. Therefore, for example, the optical connector 3
0 is supplied to the user in a state where the assembly of the ferrule 8, the frame 34, the coupling nut 6 and the like is completed,
Even when the user side assembles the optical connector 30 by positioning and adhesively fixing the key ring, the optical connector 30 can be easily assembled, and the optical fiber 35a inserted and fixed in the ferrule 8 is highly aligned. It is also easy to ensure accuracy.

Further, in such an optical connector 30, since the shape of the key ring 31 is made simpler than that of the conventional one, it is easier to manufacture than the conventional key ring 18 shown in FIG. For example, the key ring 31 can be obtained even if the engaging pieces 21, 21 of the key ring 18 are cut, so that the key ring 31 can be manufactured at a low cost, and thus an increase in manufacturing cost can be suppressed. Furthermore, the workability of bonding between the key ring 31 and the frame 34 can be improved by a very simple measure such as forming an injection hole 36 for an adhesive in the key 33 of the key ring 31, and the portion other than the key ring of the optical connector 30 can be improved. Since almost no design change is required, it is possible to improve the bonding workability without increasing the size of the optical connector 30 and increasing the cost.

In the above embodiment, the optical connector 3 is used.
Although the type of the optical fiber 35 connected to 0 is not limited, the present invention is particularly applicable to PANDA (Polarizati).
When applied to the optical connection of polarization maintaining optical fiber such as fiber, it exerts its effect better. That is,
The optical connector 30 of the present invention has a key ring 31 for alignment.
Since it is possible to make fine adjustments by rotating the, it is more suitable than polarization-maintaining optical fiber with a structure in which a stress-applying part is provided in the clad and anisotropic strain is added to the core Can be aligned to the position
Therefore, a better connection can be easily made.

If a high alignment accuracy can be secured to the ferrule to some extent by inserting the locking groove on the ferrule side into the locking line on the frame side, the ferrule side engaged with the locking line on the frame side can be secured. It is also possible to omit the selection of the locking groove and perform the centering of the optical fiber inserted and fixed in the ferrule only by rotating the key ring. In this case, the number of forming the locking strips on the frame side and / or the locking grooves on the ferrule side can be reduced, so that the manufacturing efficiency can be improved and the cost can be reduced.

[0029]

As described above, according to the present invention, the position of the key of the key ring can be freely changed by rotating the key ring externally inserted in the frame around the frame axis, and the key ring is fixedly inserted into the ferrule. It is possible to improve the alignment accuracy of the optical fiber and the aligning workability.
Moreover, the workability of the adhesive fixing of the key ring to the frame can be improved by forming the injection hole of the adhesive for adhering and fixing the key ring that has completed the positioning in the direction around the frame axis on the key of the key ring. After the assembly of the frame, ferrule, etc.,
When positioning and fixing the key ring by rotation on the outer peripheral surface of the frame, the workability of adhesively fixing the key ring to the frame can be effectively improved.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining a schematic configuration of an embodiment of an optical connector of the present invention.

FIG. 2 is a perspective view showing a schematic configuration of a key ring in the optical connector shown in FIG.

FIG. 3 is a side sectional view showing a schematic configuration of an example of a conventional optical connector.

4 is a perspective view showing a schematic configuration of a key ring in the optical connector shown in FIG.

FIG. 5 is a perspective view showing a schematic configuration of an optical connector adapter.

[Explanation of symbols]

8 ... Ferrule, 22 ... Receiving side optical connector (optical connector adapter), 23 ... Key groove, 30 ... Optical connector,
31 ... Key ring, 33 ... Key, 34 ... Frame, 35a ... Optical fiber (naked optical fiber), 36 ...
Injection hole.

Claims (2)

[Claims] 1. A cylindrical frame, a ferrule housed in the frame by restricting rotation about an axis with respect to the frame, and a ring-shaped key ring mounted and fixed on the outer peripheral surface of the frame. By inserting the frame and the ferrule into a receiving side optical connector such as an optical connector adapter, the key protruding from the key ring is inserted into and engaged with a key groove of the receiving side optical connector. In an optical connector that is positioned around an axis and is connected to the receiving side optical connector, the key ring can be positioned by rotating in an axial direction with respect to the frame by being externally attached to the frame, Is characterized in that an injection hole for injecting an adhesive for fixing the key ring to the frame is formed therethrough. Connector. 2. A cylindrical frame, a ferrule housed in the frame by restricting rotation around the axis with respect to the frame, and a ring-shaped key ring mounted and fixed on the outer peripheral surface of the frame. By inserting the frame and the ferrule into a receiving side optical connector such as an optical connector adapter, the key protruding from the key ring is inserted into and engaged with a key groove of the receiving side optical connector. A method of assembling an optical connector that is connected to the receiving-side optical connector by performing positioning around an axis, wherein a key ring is externally inserted into a cylindrical frame that regulates rotation of the ferrule about an axis, Positioned by rotation about an axis relative to the frame, then
An optical connector assembling method characterized in that an adhesive is injected into an injection hole formed through the key, and the key ring is adhesively fixed to the frame by the adhesive.