JPH0990169A - Conversion adapter - Google Patents

Abstract

(57) An object of the present invention is to provide a conversion adapter for an optical connector-connecting ferrule that can repeatedly and closely hold ferrules of different diameters and can be easily and inexpensively processed. SOLUTION: A large-diameter inner hole portion 8 with a large diameter ferrule 7 fitted therein and a small-diameter inner hole portion 10 with a small diameter ferrule 9 fitted therein, which have the same central axis, are continuously provided to form a step on the inner diameter surface. The provided sleeve holder 1 is integrally formed of elastic synthetic resin. Then, the sleeve holder 1 is configured by being housed in an adapter housing 2 into which an optical connector plug 5 having a large ferrule diameter and an optical connector plug 6 having a small ferrule diameter are respectively fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conversion adapter used when connecting optical connectors having different ferrule diameters.

[0002]

2. Description of the Related Art As an optical connector used for facilitating connection and disconnection between optical fibers or between an optical fiber and an optical element, an optical fiber such as an SC type optical connector is used. A method of inserting the core into the core and inserting the core into the alignment sleeve to bring the end faces of the ferrule into contact with each other is now widely used.

In order to directly align and connect both ferrules to be connected by the above method, it is necessary to align each axis with extremely high accuracy because the diameter of the core is small, and the axis alignment accuracy is about 1 μm. Is required.

In the above-mentioned aligning sleeve, there are cases where plugs of optical connectors having the same ferrule diameter are connected and cases where plugs of optical connectors having different ferrule diameters are connected. At present, as a sleeve for connecting optical connector plugs of different diameter ferrules, one having a structure as shown in FIGS. 5 to 8 is known.

That is, in the sleeve shown in FIG. 5, a small-diameter inner hole b into which a small-diameter ferrule (not shown) is fitted is formed at one end of a large-diameter inner hole a into which a large-diameter ferrule (not shown) is fitted. It is a split sleeve in which a slit c is cut so as to elastically hold the ferrule in the length direction, and is integrally formed of metal or plastic.

The sleeve shown in FIG. 6 is a precision sleeve in which a large-diameter inner hole a and a small-diameter inner hole b are continuously provided on the same axis, and a step is formed on the inner diameter surface. The sleeve is integrally formed of metal. There is.

The sleeve shown in FIG. 7 is a precision sleeve formed in a double type by fitting a metal small-diameter sleeve e to a metal large-diameter sleeve d integrally.

The sleeve shown in FIG. 8 is a split sleeve type precision formed by fitting a metal small diameter precision sleeve g to one end of a metal large diameter split sleeve f provided with a slit c in the length direction. It is a sleeve.

FIG. 9 shows a stepped ferrule k having a large diameter cylindrical rod portion h and a small diameter cylindrical rod portion i having the same central axis, and an optical fiber j inserted through the central axis. ,
Split sleeves are fitted to both ends of the stepped ferrule k, and fitting sleeves for inserting and holding the optical connector plugs are externally fitted to the protruding ends of the split sleeves so as to be housed in the adapter housing.

[0010]

However, the sleeve shown in FIG. 5 is not only difficult in structure to hold two holding forces for holding a large-diameter ferrule and a small-diameter ferrule evenly. It is difficult to judge the strength.

Since the sleeve shown in FIG. 6 has a clearance for fitting and removing the ferrule with respect to the large-diameter inner hole a and the small-diameter inner hole b, the accuracy of axial alignment of both ferrules to be connected is lowered and reproduced. In addition, since the above-mentioned alignment accuracy depends on the processing accuracy, the processing cost is inevitably high.

According to the sleeve shown in FIG. 7, it is difficult to obtain the coaxiality of both the large diameter and small diameter inner holes as compared with the integral type sleeve, and there is a clearance like the sleeve shown in FIG. There is the same problem as described above.

Further, in the sleeve shown in FIG.
Since the concentricity of the large-diameter and small-diameter inner holes a and b depends on the processing accuracy of the inner small-diameter precision sleeve g, the sleeve g concerned
Is required to be processed with high precision, which results in high processing cost, which is also expensive.

In the ferrule shown in FIG. 9, the fiber j
Since the eccentricity of both ferrules to be connected affects the connection loss of the optical connector, a cumbersome polishing step is required for the coaxiality processing and the end face processing in the axial direction of the large diameter cylindrical rod portion h and the small diameter cylindrical rod portion i. Therefore, there is a problem that the processing cost increases.

The present invention has been made in view of the above-mentioned problems of the above-mentioned prior art, and a large-diameter inner hole portion and a small-diameter inner hole portion having the same central axis are connected in series. The sleeve holder with a step on the inner diameter surface is integrally molded with elastic synthetic resin, and the sleeve holder is configured to be housed inside the adapter housing. It is an object of the present invention to provide a conversion adapter for an optical connector connecting ferrule, which has a constant force, allows the ferrules to be closely aligned using their own elasticity, and is easy to process and inexpensive.

[0016]

In order to achieve the above object, the conversion adapter of the present invention includes a large-diameter inner hole portion in which a large-diameter ferrule is fitted and a small-diameter ferrule having the same central axis. An optical connector plug with a large ferrule diameter and an optical fiber with a thin ferrule are formed by integrally molding a sleeve holder with a small diameter inner hole to be fitted and a step on the inner diameter surface of the synthetic resin with elasticity. It is characterized in that the connector plugs are housed in the respective adapter housings to which they are fitted.

Of the above two types of optical connector plugs, an optical connector plug having a large ferrule diameter is used as a large fitting sleeve in the adapter housing, and an optical connector plug having a small ferrule diameter is used as a small fitting sleeve in the adapter housing. When each is pushed in, the hooks of the large and small fitting sleeves are spread by the plug frames in the radial direction, so that each optical connector plug is inserted into each fitting sleeve, and when it is inserted to a predetermined position. The respective hooks return to the inside due to the spring property of the hooks, and are engaged with the engaging portions provided on the outer surface of each plug frame.

In this way, when the two types of optical connector plugs are fitted to the large and small fitting sleeves, the large-diameter inner hole portion of the sleeve holder arranged at the shaft center of the both plugs. The large-diameter and small-diameter ferrules are fitted in the small-diameter inner hole portion, and the tip surfaces of the ferrules are butted on the same axis. The end surface of the fiber, which is elastically attached to the tip end surface of each ferrule by the urging force in the pushing direction by the intervening spring, and is inserted into the axial center of each ferrule, is held in a close contact state.

The sleeve holder is integrally formed of elastic synthetic resin, and the inner diameters of the large diameter inner hole portion and the small diameter inner hole portion are the outer diameters of the large diameter ferrule and the small diameter ferrule of the two types of optical connectors. The ferrule holding force of both the large diameter and the small diameter inner hole portions is always kept constant because the ferrules are aligned and held by utilizing the elasticity of the sleeve holder. In addition, there is no play (play) between the sleeve holder and each ferrule, and high-precision axial alignment of two types of optical connectors having different ferrule diameters is possible.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a half sectional view showing a state where two types of optical connector plugs having different ferrule diameters are fitted to the conversion adapter of the present invention, FIG. 2 is a half sectional view of the conversion adapter of the present invention, and FIG. 3 is a sleeve holder. FIG.

1 to 3, reference numeral 1 denotes a sleeve holder. 1 and 2, 2 is an adapter housing, 3 is a large fitting sleeve, and 4 is a small fitting sleeve. In FIG. 1, 5 is an optical connector plug with a large ferrule diameter, and 6 is an optical connector plug with a small ferrule diameter.

The sleeve holder 1 is integrally formed of a synthetic resin having an appropriate elasticity, for example, a synthetic resin containing glass fiber, and the ferrule 7 having a large diameter in the optical connector plug 5 is fitted in the same axial center. A large-diameter inner hole portion 8
A step is formed in the inner diameter by continuously providing the small-diameter inner hole portion 10 into which the small-diameter ferrule 9 in the optical connector plug 6 is fitted.

The large diameter inner hole portion 8 and the small diameter inner hole portion 10 are
The ferrules 7 and 9 are formed to have an inner diameter slightly smaller than the outer diameters of the ferrules 7 and 9, and the ferrules 7 and 9 are held by utilizing the elasticity of the sleeve holder 1. Further, in order to make it easier to fit the ferrules 7 and 9 into the large-diameter and small-diameter inner hole portions 8 and 10, respectively, tapered holes 8a and 10a are formed at the respective opening end portions.

Further, the outer diameter of the sleeve holder 1 is provided with a step, and the stepped portion is provided with a mounting flange 11 for mounting in the adapter housing 2.

As shown in FIGS. 1 and 2, the sleeve holder 1 described above is internally mounted on the center line of the adapter housing 2 by means of left and right large fitting sleeves 3 and small fitting sleeves 4. It The adapter housing 2 is 2
The individual housings 2a and 2b are abutted on the same line, and the respective flanges 2c and 2d are fixed by eyelets 2e ... Then, the large fitting sleeve 3 is fixed on the same axis as the adapter housing 2 by fixing the flange 3a provided around the base end thereof between the housings 2a and 2b, and at the same time, The fitting sleeve 4 is integrally formed inside the housing 2b.

Therefore, as shown in FIGS. 1 and 2, in the sleeve holder 1, the large diameter portion penetrates the shaft center hole 3b of the large fitting sleeve 3 and the flange 11 is provided around the opening of the shaft center hole 3b. Butt the outer diameter step with the housing 2
The sleeve holder 1 is fixed to the center line in the adapter housing 2 without rattling in the axial direction and the radial direction.

The large fitting sleeve 3 and the small fitting sleeve 4 are provided with hooks 3c and 4a for engaging and holding the optical connector plugs 5 and 6, as is known.

4A and 4B show another example of the sleeve holder. As shown in the figure, a single or a plurality of axially long concave grooves 12 for allowing air to escape are formed on the inner surface of the large-diameter inner hole portion 8, and the others are the same as in the above-described example.

When the recessed groove 12 is provided in this manner, when the small diameter ferrule 9 is inserted into the small diameter inner hole portion 10 of the sleeve holder 1 and then the large diameter ferrule 7 is fitted into the large diameter inner hole portion 8, Since the air in the large-diameter inner hole portion 8 escapes to the outside through the concave groove 12, the large-diameter ferrule 7 can be easily and accurately fitted to a predetermined position without receiving air resistance.

In FIG. 1, 5a and 6a are plug frames, 5b and 6b are stop rings, and 5c and 6c are springs for urging the ferrules 7 and 9 in the pushing direction.
d, 6d are knobs, 5e, 6e are fiber cords, 5
Reference characters f and 6f respectively indicate crimping.

[0031]

Since the present invention is constructed as described above, the elasticity of the sleeve holder itself can be used to enable close matching of the ferrules, and the high precision of ferrules of different diameters can be achieved. It is possible to easily achieve accurate axis alignment.

Further, since the ferrule holding force of the sleeve holder is constant, the ferrule can be repeatedly attached and detached, and at the time of "fitting" between the inner hole of the sleeve holder and the ferrule, the inner hole is tightly fitted. Since it only has to be formed, high processing accuracy is not required, it is excellent in productivity and can be processed easily and inexpensively.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an example of a conversion adapter of the present invention in a state where two types of optical connector plugs having different ferrule diameters are fitted.

FIG. 2 is a half sectional view showing the above example.

FIG. 3 is a vertical sectional view showing a sleeve holder in the above example.

FIG. 4 is a cross-sectional view showing another example of the sleeve holder.

FIG. 5 is a vertical sectional view of a split sleeve in a conventional conversion adapter.

FIG. 6 is a longitudinal sectional view showing an integral type precision sleeve in the same adapter.

FIG. 7 is a vertical sectional view showing a double type precision sleeve in the above adapter.

FIG. 8 is a vertical cross-sectional view showing a sleeve of a type in which a split sleeve and a precision sleeve are combined in the same adapter.

FIG. 9 is a vertical cross-sectional view showing a conventional stepped ferrule.

[Explanation of symbols]

 1 Sleeve holder 2 Adapter housing 5 Optical connector plug with large ferrule diameter 6 Optical connector plug with small ferrule diameter 7 Large diameter ferrule 9 Small diameter ferrule 8 Large diameter inner hole 10 Small diameter inner hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Kawahara 4-15-9 Nakano, Nakano-ku, Tokyo Sanwa Denki Kogyo Co., Ltd. (72) Yuji Shinagawa 4-15-9 Nakano, Nakano-ku, Tokyo Issue Sanwa Denki Kogyo Co., Ltd. (72) Inventor Ryo Nagase 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Shinichi Iwano 1-1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo No. 6 Japan Telegraph and Telephone Corporation (72) Inventor Kazunori Kanayama 1-1-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Kuniharu Kato 1-1-1, Uchisaiwaicho, Chiyoda-ku, Tokyo No. 6 In Nihon Telegraph and Telephone Corporation (72) Inventor Tatsuomi Matsumoto 5-5-23 Osaki, Shinagawa-ku, Tokyo Hirose Electric Co., Ltd. (72) Inventor Takashi Nishiyama Tokyo 5-5-23 Osaki, Shinagawa-ku Hirose Electric Co., Ltd. (72) Inventor Toshiaki Nakano 6-18-12 Meguro Honmachi, Meguro-ku, Tokyo Honda Communication Industry Co., Ltd. (72) Fumiaki Mochida Tokyo Meguro, Tokyo 6-18-12 Meguro Honmachi, Honda Communication Co., Ltd.

Claims (1)

[Claims] 1. A step is provided on the inner diameter surface by continuously connecting a large-diameter inner hole portion in which a large-diameter ferrule is fitted and a small-diameter inner hole portion in which a small-diameter ferrule is fitted with the same central axis. A conversion, characterized in that the sleeve holder is integrally molded with elastic synthetic resin, and the sleeve holder is housed in an adapter housing into which an optical connector plug with a large ferrule diameter and an optical connector plug with a small ferrule diameter are respectively fitted. adapter.