JPH0458002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a plug constituting an optical fiber connector used for butt-connecting optical fibers at a connection work site.

(2) Prior art and its problems In conventional optical fiber connectors, the insertion hole of the plug is filled with adhesive, the optical fiber is inserted, and after the optical fiber is fixed in the insertion hole, the plug end face is The end face of the optical fiber protruding from the insertion hole was polished to a mirror finish. According to this, a sufficient polishing effect cannot be expected in the field, and variations in connector performance are unavoidable. In addition, it was necessary to bring a polisher to the connection site, and depending on the number of connections, a lot of time was required for polishing, so in reality, it was nearly impossible to assemble the connectors at the work site. It was.

In response, an on-site assembly type connector plug shown in FIG. 1 has been proposed. This plug 1 is
An optical fiber strand insertion hole 2 is provided in the axial direction from the connector connection side end surface 4, and
A small hole 3 is provided perpendicularly to this wire insertion hole 2,
A small piece of optical fiber f1 is inserted and fixed from the end face 4 on the connector connection side to the center 5 of the small hole 3.
At the connection work site, the optical fiber cord F is inserted into the plug 1 through the large-diameter cord insertion hole 6, and its strands f2 are butted against each other at the center 5 of the small hole 3.

Here, when we conducted an experiment based on the above proposal, we found that in the central part 5 of the small hole 3, the small optical fiber piece f1 and the optical fiber piece f2 are separated by the small hole 3.
It was found that shaft misalignment was unavoidable because the two were butted together with loose fit.

Further, the wire insertion hole 2 must be formed by adding the length of the optical fiber wire piece f1 to the length required for butting. This is because unless the length of the insertion hole 2 is made as long as possible, it is not possible to reduce the phenomenon of shaft breakage at the abutting portion.
Depending on the diameter of the optical fiber f2, for example 125~
Forming a long wire insertion hole 2 of about 130 microns is difficult in actual processing. Furthermore, although the wire insertion hole 2 is required to be a perfect circle on the connector connection side end surface 4, it is difficult to form the wire insertion hole 2 accurately in roundness due to the above-mentioned length. It was hot. Therefore, in reality, the connection loss was large and it was not suitable for practical use.

(3) Purpose of the Invention The present invention was developed in order to eliminate the above-mentioned drawbacks, and its purpose is to make it possible to perform connections with high accuracy at the connection work site and to make it possible to realize them in terms of processing. That is.

(4) Features of the Invention The on-site assembly type optical fiber connector plug according to the present invention is characterized in that the sleeve having the insertion hole for the optical fiber wire is divided into a holding sleeve and a butt sleeve, which are arranged coaxially apart from each other. In addition, an adhesive layer is formed therebetween, and a small piece of optical fiber is inserted and fixed in advance approximately in the middle between the holding sleeve and the abutting sleeve. The description will be given below based on the drawings.

(5) One Embodiment of the Invention FIG. 2 is a sectional view showing an embodiment of the field-assembled optical fiber connector plug according to the present invention.

As shown in the figure, the plug base 10 includes a holding sleeve 20 having a wire insertion hole 21 as an insertion hole.
A matching sleeve 30 having an alignment hole 31 as an insertion hole, and an adhesive sleeve 40 having a cord insertion hole 41 are fixed to each other.

To be more specific, the plug base 10 is provided with a first fitting hole 12 that extends in the axial direction from the plug end surface 11, and a second fitting hole with a large diameter that communicates with the first fitting hole 12. 13 is provided, and a protrusion 14 is formed on its outer periphery to be attached to a connector (not shown). A holding sleeve 20 is fixed to the first fitting hole 12, and a butting sleeve 30 and an adhesive sleeve 40 are fixed to the second fitting hole 13, which is spaced apart from the holding sleeve 20 in the axial direction. An adhesive layer 15 is formed between the holding sleeve 20 and the butting sleeve 30 with a space between them.

The wire insertion hole 21 of the holding sleeve 20 is formed to have approximately the same diameter as the optical fiber wire, and the length of the sleeve is such that the hole can be easily machined. The length of the sleeve is sufficient as long as it can hold one end of the optical fiber piece f1 without shifting the axis, and specifically, it should be about 1/4 to 1/2 of the length of the optical fiber piece f1. Enough. The holding sleeve 20 is formed to have a diameter as small as possible so that the wire insertion hole 21 is located in a perfect circle of the connector connection side end surface 22. A tapered hole 23 is formed in the other end surface of the holding sleeve 20.

Further, the abutting sleeve 30 has a larger diameter than the holding sleeve 20, and is positioned so that one end surface 32 thereof abuts against the stepped portion 16 of the second fitting hole 13. A tapered hole 32 is provided on the other end surface of the butt sleeve 30 . Furthermore, one end surface of the reduced diameter portion 42 of the adhesive sleeve 40 is abutted against the other end surface. In the figure, 43 is a filling hole.

An assembly method and usage method based on the above configuration will be explained.

First, the holding sleeve 20 is fitted into the first fitting hole 12 and fixed. The wire insertion hole 21 and the spaced apart portion of the holding sleeve 20 are filled with adhesive to form an adhesive layer 15, and the butt sleeve 40 is fitted into the second fitting hole 13 before the adhesive hardens. Next, a small optical fiber piece f1 whose other end surface is mirror-finished is inserted from the butt sleeve side, and the holding sleeve 2
It is made to protrude from the connector connection side end surface 22 of the wire insertion hole 21 of No. 0 together with the adhesive. The protruding part is held and pulled out further, and the other mirror-finished end face is butted and positioned in the middle part of the sleeve 30, and after the optical fiber piece f1 is fixed with adhesive, it protrudes from the connector connection side end face 22. Cut out the parts and give them a mirror finish. Furthermore, after filling the matching sleeve 30 with matching oil or the like, the adhesive sleeve 40 is inserted through the second fitting hole 13 and fixed, thereby completing an on-site assembly type optical fiber connector plug. The above assembly work is performed in a factory or the like.

At the connection work site, the optical fiber f2 whose end surface is mirror-finished is inserted from the adhesive sleeve 40 side and butted against the other end surface of the optical fiber small piece f1, and then filled with adhesive from the filling hole 43 to make the optical fiber. The connection is completed by fixing the fiber cord F.

As explained above, according to the above embodiment, since the holding sleeve 20 and the matching sleeve 30 are divided, matching oil or the like can be used even if the adhesive layer 15 is interposed. The most significant feature is that the optical fiber piece f1 is fixed by the holding sleeve 20, the butt sleeve 30, and the adhesive layer 15 between both 20, 30, so that the holding distance can be increased, and the light It is possible to reduce the phenomenon of shaft breakage of the fiber piece f1.

(6) Other Embodiments of the Invention In the above embodiment, the plug base 1 and the connection sleeve 40 are separate bodies, but even if the two 1 and 40 are integrated, there is no difference in accuracy. There is no effect.

(7) Effects of the Invention As explained above, the present invention provides the following effects.

A sleeve having an insertion hole for the optical fiber strand is divided into a holding sleeve and a butt sleeve, which are arranged coaxially, and a small piece of the optical fiber strand is inserted and fixed in advance from the holding sleeve to a substantially intermediate portion of the butt sleeve. As a result, we were able to provide a field-assembled optical fiber connector plug that has good precision and can withstand practical use.

By dividing into a retaining sleeve and a butt sleeve and providing an adhesive layer between the two,
By configuring the abutting margin to be long, it is possible to prevent axis deviation at the abutting portion, and by holding the small piece of optical fiber across both sleeves, the phenomenon of axis bending can be eliminated, and connection loss can be kept to a minimum.

For the above reasons, the length of the butt sleeve can be set without considering the length of the optical fiber piece, and from this point of view as well, processing is easy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional field-assembled optical fiber connector plug, and FIG. 2 is a sectional view showing an embodiment of the field-assembled optical fiber connector plug according to the present invention. 10...Plug base, 15...Adhesive layer, 20
...Holding sleeve, 21...Element wire insertion hole, 30...
...Butt sleeve, 31...Matching hole, 40...
Adhesive sleeve, 41... Cord insertion hole, 43...
Filling hole.

Claims (1)

[Claims] 1. A sleeve having a hole through which the optical fiber wire is inserted is divided into a holding sleeve and a butting sleeve, which are arranged coaxially and spaced apart, and an adhesive layer is formed therebetween, and a substantially intermediate portion of the butting sleeve is separated from the holding sleeve. This is an on-site assembly type optical fiber connector plug in which a small piece of optical fiber wire with a mirror finish is inserted and fixed in advance.