JP2002023016A - Conversion adaptor for optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conversion adaptor for an optical connector, an adaptor with small connection loss by enabling precise alignment and surely releasing air inside conversion sleeves to the outside at the time of insertion of different diameter ferrules. SOLUTION: This conversion adaptor 1 for optical connector is structured such that it is attached to an MU conversion sleeve holder 2 and an SC sleeve holder 4; that, in the large diameter sleeve 12 part of the conversion sleeve 1 connecting and holding each of a small and a large diameter ferrule, an air vent rib 13 is provided at a prescribed part of the inner bore face situated near the boundary with the small diameter sleeve 11, while an air vent hole 14 is formed at a prescribed part of the side wall face; and that a space surrounded by the tip end face of each ferrule and inner bore face of the conversion sleeve 1 is opened to the outside through the air vent hole 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conversion adapter for an optical connector for connecting two optical connectors having different outer diameters of ferrules, and more particularly, to an inexpensive conversion capable of performing high-accuracy alignment of each ferrule. The present invention relates to a conversion adapter for an optical connector using a sleeve.

[0002]

2. Description of the Related Art As a conventional conversion adapter for an optical connector, there is one known in, for example, Japanese Patent Application Laid-Open No. 9-90169. This conventional conversion adapter for an optical connector has a sleeve made of a synthetic resin having a step formed on an inner diameter surface in which the large-diameter and small-diameter ferrules are fitted inside, in an adapter housing.

The sleeve of such a conventional optical connector conversion adapter is provided with a slit (slit) in the longitudinal direction so as to elastically hold the ferrule. There is one that performs more precise axis alignment. In the case of a sleeve having no split, in the conventional configuration, for example, a concave groove is formed along the axial direction on the inner surface of the inner hole portion into which each ferrule is inserted,
The device was designed to escape the air trapped in the inner hole to the outside.

[0004]

However, in the conventional conversion adapter for an optical connector using a sleeve having no split as described above, when the sleeve is formed of a synthetic resin, the above-described concave groove for releasing air is used. There is a problem that burrs are formed on the portion and the size varies, so that the axis deviation of each ferrule becomes large and the connection loss increases. If the sleeve is provided with a split, the air escapes to the outside through the split, thereby avoiding the above-mentioned problem. However, providing the split makes it difficult to align the axis with higher precision.

The present invention has been made in view of the above points, and enables precise axis alignment, and removes air in the inner hole portion to the outside regardless of which of the large-diameter ferrule and the small-diameter ferrule is inserted first. It is an object of the present invention to provide a conversion adapter for an optical connector having a small connection loss, which can be reliably removed.

[0006]

In order to achieve the above object, the present invention provides a fixing member for detachably fixing two optical connectors having different outer diameters of ferrules, and an optical connector attached to the fixing member. A conversion sleeve for joining the tip portions of the ferrules to each other and holding the same, wherein the conversion sleeve has a small-diameter sleeve portion having an inner hole into which the small-diameter ferrule is inserted, and a large-diameter ferrule. A large-diameter sleeve portion having an inner hole to be inserted and arranged with the central axis in the longitudinal direction coinciding with the central axis in the longitudinal direction of the small-diameter sleeve portion,
The large-diameter sleeve portion is provided at a predetermined portion of the inner diameter surface located near the boundary with the small-diameter sleeve portion, and a convex portion that abuts a part of the distal end portion of the inserted large-diameter ferrule, and a small-diameter sleeve portion. A through-hole formed at a predetermined portion of the side wall surface located near the boundary, and a space surrounded by the distal end surfaces of the small-diameter ferrule and the large-diameter ferrule and the inner diameter surface of the conversion sleeve is formed through the through-hole. It is configured to be open to the outside.

In this configuration, when two optical connectors having different outer diameters of ferrules are connected to the optical connector conversion adapter, the large diameter ferrule inserted into the large diameter sleeve portion has a part of the tip portion. The small-diameter ferrule held in contact with the convex portion and inserted into the small-diameter sleeve portion is
It is held in a state of being joined to the distal end surface of the large diameter ferrule.
At this time, air in the space surrounded by the distal end surface of each ferrule and the inner diameter surface of the conversion sleeve is formed between the inner diameter surface of the large diameter sleeve portion and the distal end surface of the large diameter ferrule by the convex portion. Since it is released to the outside of the conversion sleeve through the gap and the through-hole, poor joining due to the incorporation of air can be avoided.

In the above-mentioned optical connector conversion adapter, the large-diameter sleeve portion may have a concave portion at a predetermined portion of the outer diameter surface, and the gate processing may be performed at the time of molding corresponding to the concave portion. Good. With this configuration, when the conversion sleeve is molded using the mold, the gate portion corresponding to the material injection portion does not protrude outside the outer diameter of the large-diameter sleeve portion due to the provision of the concave portion. Gate processing at the time can be easily performed.

Further, as a specific configuration of the optical connector conversion adapter, each optical connector may be an MU type optical connector and an SC type optical connector.
The C-type optical connector and the SC-type optical connector may be used.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the entire structure of a conversion adapter for an optical connector according to an embodiment of the present invention. FIG. 2 is a diagram showing an arrangement of each optical connector connected using the optical connector conversion adapter of FIG.

In each of the drawings, the present optical connector conversion adapter 10 includes, for example, an MU type optical connector 50 having a relatively small diameter ferrule 50A and an SC type optical connector 51 having a relatively large diameter ferrule 51A. MU-SC conversion type adapter, specifically, a conversion sleeve 1 and M as a fixing member.
It comprises a U conversion sleeve holder 2, an MU conversion adapter housing 3, an SC sleeve holder 4, and an SC adapter housing 5.

FIG. 3 is a diagram showing a specific example of the structure of the conversion sleeve 1, wherein FIG.
(B) is a side view seen from below, and (C) is a side view seen from right.

The conversion sleeve 1 shown in FIG. 3 has a small-diameter sleeve portion 11 and a large-diameter sleeve portion 12, and the respective sleeve portions 11, 12 are integrally formed using a synthetic resin. As a specific material of the conversion sleeve 1, for example,
It is possible to use a thermoplastic resin such as a wholly aromatic liquid crystal polymer (LCP) or polyphenylene sulfide (PPS). However, the material of the conversion sleeve applied to the present invention is not limited to the above.

The small-diameter sleeve portion 11 has a structure in which the small-diameter ferrule 50A of the MU-type optical connector 50 is inserted from the left opening in FIG. 3A, and holds the small-diameter ferrule 50A at a predetermined position. The diameter of the inner hole of the small-diameter sleeve portion 11 is set so that the force for holding the ferrule (hereinafter referred to as the insertion / extraction force) becomes a required value.
(The ferrule diameter of a general MU-type optical connector is 1.249 mm). In addition,
Here, a taper is formed at the opening end to facilitate the insertion of the ferrule into the small-diameter sleeve portion 11, but this taper can be omitted.

The large-diameter sleeve portion 12 has a structure in which the large-diameter ferrule 51A of the SC type optical connector 51 is inserted from the right opening in FIG. 3A, and the large-diameter ferrule 51A is held at a predetermined position. have. The diameter of the inner hole of the large-diameter sleeve portion 12 depends on the outer diameter of the large-diameter ferrule 51A (the ferrule diameter of a general SC-type optical connector is 2.499 mm) so that the insertion / extraction force has a required value. Designed in advance. In addition, the large-diameter sleeve portion 12 has the small-diameter sleeve portion 1 attached thereto.
An air bleeding rib 13 is formed as a convex portion at a predetermined portion of the inner diameter surface located near the boundary b with 1. As shown in FIG. 3 (C), the air release ribs 13 are formed at three locations on the inner diameter surface, and the surface facing the inserted large diameter ferrule 51A faces the large diameter ferrule 51A.
Abuts the tip of the Further, the large-diameter sleeve portion 12 has a side wall surface near the boundary b with the small-diameter sleeve portion 11 (FIG. 3).
The air vent hole 14 penetrating from the inside to the outside is formed as a through hole at one location on the lower side wall surface. In addition,
The shapes and numbers of the air release ribs 13 and the air release holes 14 are not limited to the above. Also, here, the tapered portion is formed at the opening end of the large-diameter sleeve portion 12, but the tapered portion can be omitted.

In addition, a D-cut 15 is provided at a predetermined portion of the outer diameter surface of the large-diameter sleeve portion 12 as a concave portion for facilitating gate processing at the time of forming the sleeve. That is, when the conversion sleeve 1 is formed by injecting a material into a mold, as shown in a side view seen from below in FIG. 4, a gate portion 15A corresponding to a material injection portion is cut to finally convert. The sleeve 1 is completed. If the gate portion 15A remaining in the conversion sleeve 1 projects outside the outer diameter of the large-diameter sleeve portion 12, the large-diameter sleeve portion 12 cannot be attached to the SC sleeve holder 4 as described later. In order to avoid the above-mentioned inconveniences and facilitate gate processing at the time of forming the sleeve, the D-cut 15 lowers the outer diameter surface corresponding to the gate portion 15A by one step, and cuts the tip of the gate portion 15A after cutting. Is located inside the outer diameter of the large-diameter sleeve portion 12.

In the conversion sleeve 1 as described above, as shown in FIGS. 1 and 2, the small-diameter sleeve portion 11 is inserted into the MU conversion sleeve holder 2, and the large-diameter sleeve portion 12 is
It is inserted into the C sleeve holder 4. Further, the MU conversion sleeve holder 2 and the SC sleeve holder 4 into which the conversion sleeve 1 is inserted are inserted into the MU conversion adapter housing 3 and the SC adapter housing 5, respectively, and the respective parts are fused or the like, so that the optical connector is used. The conversion adapter 10 is configured. The SC sleeve holder 4 and the SC adapter housing 5 can use the respective components for the SC type connector used in the existing optical connector conversion adapter.

Next, the operation of the embodiment will be described. FIG. 5 is an enlarged sectional view of the conversion sleeve 1 when the MU-type optical connector 50 and the SC-type optical connector 51 are attached to the present optical connector conversion adapter 10, and FIG. The state before the ferrules 50A and 51A of each optical connector are inserted into the conversion sleeve 1 is shown, and the state after the insertion is shown in FIG.

First, the case where the SC type optical connector 51 is attached to the optical connector conversion adapter 10 before the MU type optical connector 51 will be described. When the right-hand large-diameter ferrule 51A is inserted into the conversion sleeve 1 from the state shown in FIG. 5A, the small-diameter ferrule 50A is inserted at this stage as shown in FIG. 5B. No), the tip of the large-diameter ferrule 51A enters along the inner diameter surface of the large-diameter sleeve 12 and the small-diameter sleeve 1
3 air bleeding ribs 1 formed near the boundary with 1
3 is fixed in a state of contact. The SC optical connector 51 inserted into the optical connector conversion adapter 10 is
It is held by the structure of the SC sleeve holder 4 and the SC adapter housing 5.

Next, when the small diameter ferrule 50A is inserted into the conversion sleeve 1 in such a state, the tip of the small diameter ferrule 50A enters along the inner diameter surface of the small diameter sleeve portion 11. At this time, each ferrule 50A, 51A
In addition, the air in the space surrounded by the inner hole of the conversion sleeve 1 passes through the air vent hole 14 formed in the large-diameter sleeve portion 12 and flows out of the conversion sleeve 1. Therefore, the small-diameter ferrule 50A can approach the tip of the large-diameter ferrule 51A with almost no air resistance. In the above-described air bleeding path, a gap is formed between the inner diameter surface of the conversion sleeve 1 and the distal end surface (including the tapered portion) of the large-diameter ferrule 51A by providing the air bleeding rib 13, so that a small diameter is obtained. It is secured even when the tip of the ferrule 50A approaches the tip of the large diameter ferrule 51A. As a result, no air is trapped in the conversion sleeve 1 and the small-diameter ferrule 50A
In addition, the tip surfaces of the large-diameter ferrule 51A surely adhere to each other. The MU-type optical connector 50 inserted into the optical connector conversion adapter 10 is held by the structure of the MU conversion sleeve holder 2 and the MU conversion adapter housing 3.

The air discharged out of the conversion sleeve 1 through the air vent hole 14 passes through the gap along the longitudinal direction between the conversion sleeve 1 and the SC sleeve holder 4 and the MU conversion sleeve holder 2 to emit light. It is discharged to the outside of the connector conversion adapter 10. Further, here, as shown in FIG. 6 which is an enlarged view of the range (a) of FIG. 1, a positional relationship is set such that a part of the air vent hole 14 is open to the R portion of the SC sleeve holder 4. This makes air discharge more reliable and smoother. However, even in the SC sleeve holder 4 in which the R portion is not provided as described above, as long as the conversion sleeve 1 and each of the sleeve holders 2 and 4 are not tightly fixed, there is a gap between them. Existence allows air to be exhausted.

In the above description, it is assumed that the SC optical connector 51 is attached before the MU optical connector 50, but it is of course possible to attach the MU optical connector 50 first. In this case, since the tip of the small-diameter ferrule 50A of the MU-type optical connector 50 inserted first does not abut the air-releasing rib 13, the contact surface between the air-releasing rib 13 and the large-diameter ferrule 51A. Than the large-diameter ferrule 51A. When the SC optical connector 51 is attached in such a state, the distal end of the large-diameter ferrule 51A abuts and is fixed to the air release rib 13 while pushing down the distal end of the small-diameter ferrule 50A. Even in such a series of states, a path for bleeding air from the conversion sleeve 1 is always secured, so that the tips of the ferrules 50A and 51A can be brought into close contact.

When the MU-type optical connector 50 and the SC-type optical connector 51 mounted on the optical connector conversion adapter 10 are to be removed, the conversion sleeve 1 and the respective sleeves are reversed in the above-described manner. When the air flows into the conversion sleeve 1 through the gap between the holders 2 and 4 and the air vent hole 14, the optical connectors 50 and 51 can be smoothly removed.

As described above, according to the optical connector conversion adapter 10, the air connector rib 13 and the air vent hole 14 are formed in the precision type conversion sleeve 1 having no split, thereby mounting the optical connector. At this time, the air in the conversion sleeve 1 is reliably discharged, so that the joining failure due to the mixing of the air can be eliminated. This makes it possible to provide a conversion adapter for an optical connector in which the connection loss of the different-diameter ferrule is significantly reduced. Forming the air bleeding rib 13 and the air bleed hole 14 in the conversion sleeve 1 is less affected by burrs and dimensional variations than in the case of forming a concave groove as in the prior art. Can be performed with higher accuracy. Further, the conversion sleeve 1 as described above
Can be made inexpensively because it can be integrally molded with a mold using synthetic resin as a material. In addition, if the D-cut 15 is provided, gate processing at the time of molding can be facilitated, so that mass productivity is excellent. . Further, since existing parts can be used for the SC sleeve holder 4 and the SC adapter housing 5, it is possible to provide a conversion adapter for an optical connector at a lower cost.

In the above embodiment, the MU-SC
Although the conversion type adapter has been described, the present invention is not limited to this. For example, an LC-SC conversion type adapter for connecting the LC type optical connector and the SC type optical connector can be applied in the same manner as in the above-described embodiment.

FIG. 7 is a view showing an example of an optical connector conversion adapter (LC-SC conversion type) according to the present invention, together with an LC type optical connector and an SC type optical connector. The same parts as those in the above-described embodiment are denoted by the same reference numerals.

Conversion adapter 1 for optical connector shown in FIG.
At 0 ′, L having a relatively small diameter ferrule 52A
A C-type optical connector 52 (a ferrule diameter of a general LC-type optical connector is 1.249 mm) is connected to an SC-type optical connector 51 having a ferrule 51A having a relatively large diameter. The difference between the configuration of this optical connector conversion adapter 10 'and the configuration of the MU-SC conversion type described above is that
The MU conversion sleeve holder 2 used in the -SC conversion type is omitted, and an LC conversion adapter housing 6 is provided instead of the MU conversion adapter housing 3. Therefore, the conversion sleeve 1 and the configuration on the SC side (SC sleeve holder 4 and SC adapter housing 5) are the same as those of the MU-SC conversion type.

The above-described LC-SC conversion type adapter 10 'can provide the same operation and effects as those of the MU-SC conversion type adapter 10. In addition, even if adapters of different conversion types are used, some parts such as the conversion sleeve 1 can be shared, so that the conversion adapter for optical connectors can be further reduced in cost.

[0029]

As described above, the conversion adapter for an optical connector according to the present invention is provided with a projection and a through-hole in the large-diameter sleeve portion of the conversion sleeve which is not split, so that the conversion sleeve can be installed when the optical connector is mounted. The air is reliably discharged to the outside, so that it is possible to eliminate the joining failure due to the mixing of the air. Accordingly, it is possible to provide an inexpensive optical connector conversion adapter in which the axes of the different diameter ferrules can be aligned with high accuracy and the connection loss is significantly reduced. In addition, if a concave portion is provided on the outer diameter surface of the large-diameter sleeve portion, the gate processing at the time of molding can be facilitated, so that mass productivity is excellent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the entire structure of a conversion adapter for an optical connector according to an embodiment of the present invention.

2 is a diagram showing an arrangement of each optical connector connected by using the optical connector conversion adapter of FIG. 1;

3A and 3B are diagrams showing a specific configuration example of a conversion sleeve used in the embodiment of the present invention, wherein FIG. 3A is a cross-sectional view as viewed from the front, FIG. 3B is a side view as viewed from below, and FIG. ) Is a side view as viewed from the right.

FIG. 4 is a diagram illustrating a D-cut of a conversion sleeve used in the embodiment of the present invention.

FIG. 5 is a cross-sectional view showing, in an enlarged manner, a conversion sleeve when a MU-type optical connector and an SC-type optical connector are attached to an optical connector conversion adapter according to the embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a range (a) in FIG. 1;

FIG. 7 is a diagram showing an example in which the present invention is applied to an LC-SC conversion type adapter together with each optical connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conversion sleeve 2 MU conversion sleeve holder 3 MU conversion adapter housing 4 SC sleeve holder 5 SC adapter housing 6 LC conversion adapter housing 10, 10 'Conversion connector for optical connectors 11 Small diameter sleeve part 12 Large diameter sleeve part 13 Air release rib 14 Air vent hole 15 D cut 15 A Gate 50 MU type optical connector 51 SC type optical connector 52 LC type optical connector 50 A, 51 A, 52 A Ferrule

Continued on the front page (72) Inventor Mikiya Komatsu 821 Miyamaecho, Omiya-shi, Saitama Nisshin Kaseinai F-term (reference) 2H036 QA00 QA47 2H037 BA31 CA00

Claims (4)

[Claims] 1. A fixing member for detachably fixing two optical connectors having different outer diameters of ferrules, and a conversion sleeve attached to the fixing member and joining and holding the tip ends of the ferrules of the respective optical connectors to each other. Wherein the conversion sleeve has a small-diameter sleeve portion having an inner hole into which a small-diameter ferrule is inserted, and an inner hole into which a large-diameter ferrule is inserted, and has a longitudinal central axis. A large-diameter sleeve portion arranged so as to coincide with the longitudinal center axis of the small-diameter sleeve portion, and the large-diameter sleeve portion has a predetermined inner diameter surface located near a boundary with the small-diameter sleeve portion. Provided at the site, a convex portion abutting a part of the tip portion of the large diameter ferrule to be inserted, and a predetermined portion of the side wall surface located near the boundary with the small diameter sleeve portion Having a through hole formed therein, wherein a space surrounded by the distal end surfaces of the small diameter ferrule and the large diameter ferrule and the inner diameter surface of the conversion sleeve is opened to the outside through the through hole. A conversion adapter for an optical connector. 2. The light according to claim 1, wherein the large-diameter sleeve portion has a concave portion at a predetermined portion of an outer diameter surface, and a gate process at the time of molding is performed corresponding to the concave portion. Conversion adapter for connectors. 3. The optical connector according to claim 1, wherein each of said optical connectors is an MU type optical connector and an SC type optical connector.
Or the conversion adapter for an optical connector according to 2. 4. The optical connector according to claim 1, wherein said optical connectors are an LC type optical connector and an SC type optical connector.
Or the conversion adapter for an optical connector according to 2.