JPH0546003Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an optical transmission adapter that couples two optical connectors. [Background Art and Problems thereof] Recently, many optical fibers have been developed as a result of research and development of optical fibers. Among them, the GI type for long distance transmission has a core diameter of 50μm and a cladding diameter of 50μm.
For FC type optical connectors using 125μm quartz fiber, the material of the ferrule of the optical connector is
Hard materials such as SUS440C and ceramics. Therefore, the optical fiber portion on the end face of the optical connector can be polished into a concave spherical shape so that the optical fiber does not protrude from the ferrule end face of the optical connector. When optical connectors are connected to each other, light is reflected multiple times by the concave spherical surface of the optical fiber at the end face of the optical connector, which has a positive effect on the reproducibility of connection loss of the optical connectors. However, in optical connectors using optical fibers for short and medium distances, the ferrule is made of a soft material such as brass, so only the optical fiber portion on the end face of the optical connector is polished into a concave spherical shape. It was difficult to polish the optical fiber so that it did not protrude from the end face of the ferrule. Therefore, when connecting optical connectors, if you design an optical transmission adapter so that the ferrule end faces of the optical connectors touch each other, reproducibility may deteriorate or the optical fibers protruding from the ferrule end faces of the optical connectors may A cracking phenomenon occurs,
This had a large impact on optical transmission loss. Also, if you design an optical transmission adapter so that there is a gap between the ferrules of the optical connector so that the optical fibers do not touch each other, the phenomenon of optical fibers breaking will disappear, but
Due to the dimensional tolerance of the adapter, the dimensional tolerance of the optical connector, the polishing tolerance of the ferrule of the optical connector, etc., it becomes difficult to manage the gap between the ferrules of the optical connector, resulting in a problem that the reproducibility of the connection loss of the optical connector deteriorates. Therefore, an optical transmission adapter as shown in FIG. 5 has been proposed. This optical transmission adapter includes a spacer 5 having a through hole 4 larger than the core diameter of the optical fiber cable between the ferrule 3 of the first optical connector 1 and the ferrule 3 of the second optical connector 2. It was established. However, with this optical transmission adapter,
When the adapter body 6 is molded with resin, the dimensional accuracy of the hole diameter for fitting and aligning the ferrules 3 of both optical connectors 1 and 2 cannot be achieved, resulting in a large connection loss and also making manufacturing difficult. There was a problem. In the figure, 7 is an annular recess, and this annular recess allows the spacer 5 to move in the axial direction inside the adapter body 6. [Purpose of the invention] The purpose of the invention is to provide an optical transmission adapter that solves the above-mentioned problems, improves connection loss of an optical connector, and facilitates manufacturing. [Summary of the invention] This invention includes a metal sleeve on the inside of the adapter body in which the ferrule of the first optical connector and the ferrule of the second optical connector are fitted and aligned. This is an optical transmission adapter arranged so that the through groove portion of the sleeve corresponds to the sleeve. [Embodiment of the invention] The optical transmission adapter of this invention is constructed as shown in FIG. 1, and the same parts as those in FIG. 5 are given the same symbols. That is, the cylindrical adapter main body 6 made of resin has a window 8 for inserting a spacer formed near the center thereof. Furthermore, a metal sleeve 9 is disposed inside the adapter body 6. In this case, a through hole 10 is formed in the adapter body 6, and a metal sleeve 9 is press-fitted into this through hole 10. This metal sleeve 9 is, for example, as shown in FIG.
It is constructed as shown in b, c, and d, with a through groove 11 for inserting a spacer formed in the center, and large diameter portions at both ends. Also, the outer diameter of both ends is through hole 10.
is slightly larger than the inner diameter of the A flat portion 12 is formed in this large diameter portion as a rotation prevention mechanism. Furthermore, on the inner peripheral surface of the metal sleeve 9,
A circumferential recess 16 is formed corresponding to the transparent portion 11 . Moreover, this metal sleeve 9 is
Accurately molded with inner diameter accuracy within 5μm. As for the assembly procedure, first, such a metal sleeve 9 is inserted into the through hole 1 of the adapter body 6 as described above.
At this time, the metal sleeve 9 is fixed so that the window portion 8 and the through groove portion 11 correspond to each other. Then, the corresponding window part 8 and the transparent groove part 1
1, a rotation prevention mechanism for the sleeve 9, that is, a flat portion 12 is provided. Furthermore, when the ferrule 3 of the first optical connector 1 and the ferrule 3 of the second optical connector 2 are fitted and aligned to face each other in the metal sleeve 9, the distance between the end faces of each ferrule 3 is as follows. In order to make the connection loss uniform and to reduce variations in connection loss, a spacer 5 is provided between the two ferrules 3, 3, that is, in the recess 16. This spacer 5 has a thickness of 0.1mm
The following is a plate shape having a semicircular part corresponding to the recess 16 of, for example, 0.05 mm, and approximately in the center has a diameter larger than the core diameter of the optical fibers of the first and second optical connectors 1 and 2 , and a diameter of the ferrules 3 and 3. It has a smaller through hole 4. Such a spacer 5 is inserted into the recess 16 in the metal sleeve 9 from the outside through the window 8 of the adapter body 6 and the groove 11 of the metal sleeve 9, that is, the ferrule 3 of the first optical connector 1 and the second ferrule 3 of the first optical connector 1 . is inserted between the ferrule 3 of the optical connector 2 and the ferrule 3 of the optical connector 2. Thereafter, the window 8 is closed with a cap 13. As is clear from FIGS. 2a and 2b, the metal sleeve 9 has a small diameter part at the center and large diameter parts at both ends. When cutting, the shavings are removed from the groove 11.
This is to prevent it from being blocked. Note that FIG. 3c is a sectional view, and FIG. d is a sectional view taken along line A-A' in FIG. [Effects of the invention] According to this invention, when the sleeve 9 is press-fitted into the adapter body 6, the flat part 1 of the outer circumference of the sleeve 9
2 allows the sleeve 9 to be inserted without rotating, so that the groove 11 of the sleeve 9 does not shift from the window 8 when the spacer 5 is inserted into the sleeve 9. In addition, the ferrule 3 of the first optical connector 1 and the second
Since the sleeve 9 is used in the part where the ferrule 3 of the optical connector 2 is fitted, the accuracy of the hole diameter can be improved. Furthermore, the gap between each ferrule 3 of the first optical connector 1 and the second optical connector 2 is also filled with a spacer 5.
Therefore, each optical connector 1 , 2
An optical transmission adapter with low connection loss and good reproducibility can be obtained. [Modifications of the invention] FIGS. 3a and 3b and 4a and 4b show modifications of the metal sleeve, and the same effects as in the above embodiment can be obtained. That is, in the case of FIGS. 3a and 3b, uneven portions 14 are formed on the outer periphery of the large diameter portion at both ends of the metal sleeve as a rotation prevention mechanism. In addition, in the case of Fig. 4 a and b, the metal sleeve 9
A protrusion 15 is formed on the outer periphery of the large diameter portion at both ends as a rotation prevention mechanism.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an optical transmission adapter according to an embodiment of the invention, and Fig. 2 a, b, c, and d are front and side views showing a sleeve used in the optical transmission adapter of this invention. 3A and 4B are front and side views showing modified examples of the sleeve, and FIG. 5 is a sectional view showing a proposed optical transmission adapter. 1 ...Optical connector, 2 ...Optical connector, 3...
Ferrule, 4...Through hole, 5...Spacer, 6...
...Adapter body, 9...Metal sleeve, 11...
...Permeable groove part, 12... Flat part, 14... Uneven part, 1
5... Protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) An adapter body made of resin; first and second optical connectors each having at least a ferrule and an optical fiber cable that are coupled to each other within the adapter body; and the inside of the adapter body. The ferrule of the first optical connector and the second
a metal sleeve in which the ferrules of the optical connector are fitted and aligned, and the ferrule of the first optical connector and the ferrule of the second optical connector are disposed between the metal sleeve and the ferrule is larger than the core diameter of the optical fiber cable. An optical transmission adapter characterized in that it has a through hole and a spacer that sets a certain gap between the ferrules of the first and second optical connectors. (2) Utility model registration claim 1, characterized in that a rotation prevention mechanism is provided on the outer periphery of the sleeve.
Optical transmission adapter described in section. (3) The optical transmission adapter according to claim 2, wherein the rotation prevention mechanism is a flat portion parallel to the axial direction formed on the outer periphery of the sleeve. (4) The metal sleeve has a through groove for arranging the spacer, and the adapter body has a window corresponding to the through groove, and the window is closed by the cap. The optical transmission adapter according to claim 1, characterized in that the optical transmission adapter is closed.