JPH0342405Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber connector used for connecting optical fibers.

Optical fibers are very thin, with a diameter of about 100 μm or less, and connecting them requires precise alignment. Conventional optical connectors for achieving this purpose have a common structure in which an optical fiber is inserted into a hole in a sleeve, and the sleeves are inserted into a connector outer cylinder and brought together. However, with this structure, the hole in the sleeve must be machined with extremely high precision, making it difficult to manufacture.Also, if the diameter of the optical fiber changes, the hole diameter in the sleeve must be changed accordingly, so each time the hole diameter is changed, The unavoidable drawback was that the specifications of the sleeve had to be changed.

The present invention eliminates the drawbacks of conventional devices and proposes an optical fiber connector that ensures optical axis alignment and can easily handle changes in optical fiber diameter. A pair of connector inner cylinders to be inserted into the connector are each formed with a tapered hole that gradually decreases in diameter toward the connection end surface, which connects to the tip of the shaft hole, and the optical fiber holding cylinder is inserted into the shaft hole of the connector inner cylinder. The tapered hole is divided into two or more parts, and the tapered hole has an outer taper corresponding to the taper of the tapered hole and a shaft V groove into which the end of the optical fiber to be connected is inserted. The present invention is characterized in that an optical fiber clamping member made of a truncated cone is inserted, and the optical fiber clamping member is pressed against the connecting end surface of the optical fiber by the optical fiber holding tube.

The invention will now be described with reference to the illustrated embodiments. FIG. 1 shows the connected state of the optical fiber connector according to the present invention, in which a pair of connector inner tubes 5, 5 are inserted into the connector outer tube 1 so as to be movable in the axial direction. The inner diameter of the outer cylinder 1 and the outer diameter of the inner cylinder 5 are both machined with high dimensional accuracy so that they fit together without any play.
Expanding diameter tapered parts 2, 2 are formed at both ends of the inner diameter part of the connector outer cylinder 1 to facilitate insertion of the inner cylinder 5, and external threads 3, 3 are formed on the outer periphery to screw together the fastening rings 4, 4.
is screwed on. The fastening rings 4, 4 have their flange parts 4a, 4a in contact with the outer ends of the connector inner cylinders 5, 5, and when they are tightened, the inner end connecting end surfaces 1 of the inner cylinders 5, 5
8 and 18 are in close contact.

A shaft hole 7 is formed in the connector inner cylinders 5, 5, and the tip end (inner end) of the shaft hole 7 is a tapered hole 7a whose diameter gradually decreases toward the connection end surface side. Optical fiber clamping members 8, 8, the details of which are shown in FIGS. 2 to 4, are inserted into the tapered hole 7a. The clamping members 8, 8 are made of truncated cones having an outer taper of the same taper as the taper of the tapered hole 7a, and the radius changes continuously from t1 to t2 as shown in FIG. It has the shape of a truncated cone divided into two by a plane passing through its center line, and a V-groove 9 with a depth t0 is provided at its center axis. The ends of the optical fibers 13 to be connected are sandwiched between the V-grooves 9, 9 of the clamping members 8, 8, and the V-grooves 9, t0, t1, and t2 are machined with high dimensional accuracy. .

The shaft hole 7 has a large diameter portion 11 of the optical fiber holding cylinder 10.
is inserted. The shaft hole 10a of the holding tube 10 has an inner diameter slightly larger than the protective coating 14 of the optical fiber 13 in order to hold the protective coating 14 on its shaft, and the optical fiber clamping member 8, It has a small diameter portion 12 that abuts on the portion 8 . The diameter of this small diameter portion 12 is the radius t2 of the optical fiber clamping member 8.
It is set smaller than twice.

Male threads 16, 16 are threaded on the outer periphery of the protruding ends of the connector inner cylinders 5, 5 from the fastening rings 4, 4, and second fastening rings 17, 17 are screwed into the male threads 16. When this second fastening ring 17 is tightened, the flange portion 17a is tightened to the optical fiber holding tube 1.
0, the small diameter portion 12 of this holding cylinder pushes out the optical fiber clamping members 8, 8 toward the connection end surface side. Note that the rear end portions of the V-grooves 9, 9 of the optical fiber clamping members 8, 8 are provided with diameter-enlarging tapered portions 1 to facilitate insertion of the optical fibers.
5 and 15 are formed.

For example, the optical fiber connection operation using the present optical fiber connector having the above configuration is performed as follows. First, from the state shown in FIG. 1, the fastening rings 4, 4 are removed, and the connector inner cylinders 5, 5, to which the second fastening rings 17, 17 are screwed together at the rear, are removed. After that, when the second fastening ring 17 is loosened, the optical fiber holding cylinder 10 and the optical fiber clamping members 8, 8 can be retreated, and the clamping members 8, 8
When the V-grooves 9 move backward, the space between the V-grooves 9 and 9 of the shaft portions opens, allowing insertion of the optical fiber 13. In this state, the optical fiber 13 is inserted into the shaft hole 10a of the optical fiber holding cylinder 10 together with the protective coating 14, and the connecting end of the optical fiber 13 without the protective coating is positioned between the clamping members 8, 8. After that, when the second fastening ring 17 is tightened, the optical fiber clamping members 8, 8 are attached to the tapered hole 7.
Since the clamping members 8 and 8 are pressed in the direction in which the diameter of
The central axis of the optical fiber 13 sandwiched between the V-grooves 9 and 9 of the shaft portion 8 coincides with the axis of the connector inner cylinder 5.
The above dimensions t0 of the clamping members 8, 8 and the V grooves 9, 9,
Since t1 and t2 are processed with high precision, the distances t4 and t4 (the distances t4 and t4 from the part where the outer tapers of the two divided clamping members 8, 8 contact the taper hole 7a to the center of the optical fiber 13) 3) are equal to each other regardless of the diameter of the optical fiber 13, and therefore, the central axis of the optical fiber of any diameter can be made to coincide with the axis of the connector inner cylinder 5. Note that during this connection work, the optical fiber 1
3, fill the shaft hole 7 and the tapered hole 7a, including between the holding tube 10 and the optical fiber protective coating 14 and between the optical fiber 13 and the V-groove 9, with adhesive. In addition, optical fiber 1
In order to reduce the end face loss of connector 3, it is preferable to polish the end face to the same surface as the connecting end face 18 of the connector inner cylinder 5.

Therefore, the connector inner tubes 5, 5 holding the optical fiber 13 in the shaft portion in this manner are connected to the connector outer tube 1.
By inserting the optical fibers from both sides and tightening the fastening rings 4, 4 to bring the connection end surfaces 18, 18 into close contact, the optical axes of the pair of optical fibers will coincide, and accurate connection between the optical fibers can be achieved.

FIG. 5 shows another embodiment of the optical fiber clamping member 8, in which V is provided on the tapered outer wall as a forward/retreat guide.
A groove 19 is formed in the axial direction along the outer taper. The tapered hole 7a of the connector inner cylinder 5 is provided with a V protrusion that fits into the guide V groove 19, and the direction of movement of the clamping member is regulated by the V groove and the V protrusion. According to this example, the shaft V groove 9 is connected to the connector inner cylinder 5.
There is no possibility of tilting with respect to the axis of the optical fiber 13, thus making it easier to insert the optical fiber 13 into the shaft V-groove 9. As described above, the diameter-expanding taper portion 15 at the rear end of the shaft V-groove 9 facilitates insertion of the optical fiber. It is clear that the guide groove 19 and the protrusion may have a shape other than the V-shape, such as a square shape or a semicircular shape.

In the above embodiment, the optical fiber clamping members 8, 8 are of a two-part type, but it is also possible to have three or more parts. In other words, a truncated cone whose radius changes continuously from t1 to t2 is divided into multiple pieces of the same size along a plane passing through its central axis, and a V-groove for holding an optical fiber is provided in each central axis. If so, the present invention is valid.

In summary, the optical fiber connector of the present invention is
An optical fiber to be connected is held between two or more divided truncated cone-shaped optical fiber clamping members between the V-grooves of the shank, and this clamping member is formed in the shank of a pair of connector inner cylinders. Since they are inserted into each hole and pressed against the connection end surface, the optical axis of the optical fiber to be connected can be adjusted by matching the taper of the truncated cone and the taper of the tapered hole, regardless of the diameter of the optical fiber. Since the optical fiber connectors are aligned correctly and held so as not to shift from their positions, the optical fiber connector can be used for general purposes.

Furthermore, in the present invention, both connector inner cylinders holding the optical fibers centered are inserted into the connector outer cylinder from both sides, and the fastening rings are tightened to bring the connection end faces into close contact.
Accurate alignment of optical fibers. Even if the smoothness or transparency of the optical fiber end face is impaired, it can be easily polished so that it is flush with the connection end face of the connector inner cylinder before inserting it into the connector outer cylinder. transmission loss can be reduced.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing an embodiment of the optical fiber connector of the present invention in a connected state, Fig. 2 is a perspective view of a pair of optical fiber clamping members in an assembled state, Fig. 3 is a front view of the same, and Fig. 4 is a perspective view of a pair of optical fiber clamping members in an assembled state. This figure is a perspective view of a single optical fiber clamping member, and FIG. 5 is a perspective view showing another embodiment of the optical fiber clamping member. 1... Connector outer cylinder, 4... Fastening ring, 5... Connector inner cylinder, 7... Shaft hole, 7a... Taper hole, 8
...Optical fiber clamping member, 9...V groove, 10...
Optical fiber holding cylinder, 13... Optical fiber, 14...
...Optical fiber protective coating, 17...Second fastening ring, 1
8... Connection end surface.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A connector outer cylinder; a pair of connector inner cylinders that are fitted into this connector outer cylinder from both sides; A fastening ring that holds the pair of connector inner cylinders with their connecting end faces in close contact with each other; a shaft hole formed in each of the pair of connector inner cylinders on the outer end side; an optical fiber holding tube that holds an optical fiber and is movably inserted into the shaft hole of the connector inner tube; and a tapered hole of the connector inner tube; A truncated cone having an outer taper corresponding to the taper and a shaft V-groove into which the end of the optical fiber to be connected held in the optical fiber holding tube is fitted, and divided into two or more on a plane passing through the axis. the optical fiber clamping member; a second fastening ring that is screwed onto the outer end of the connector inner cylinder and presses the optical fiber holding cylinder toward the optical fiber connection end surface; An optical fiber connector, wherein the optical fiber connector is inserted into the tapered hole of the pair of connector inner cylinders, and is pressed toward the connecting end surface of the optical fiber by the optical fiber holding cylinder. (2) In claim 1 of the utility model registration claim, there is provided an optical fiber connector in which the rear end of the V-groove of the shaft portion of the fiber clamping member is formed with an enlarged diameter tapered portion to facilitate insertion of the optical fiber. . (3) In claim 1 of the utility model registration claim, one of the tapered hole of the inner cylinder of the connector and the outer taper of each optical fiber clamping member has a groove or protrusion extending in the axial direction, and the other has a groove or protrusion that fits therein. An optical fiber connector in which a protrusion or a groove is formed, and the optical fiber clamping member is inserted into each of the tapered holes of the pair of connector inner cylinders, and is guided forward and backward along the fitting groove and the protrusion.