JP4227722B2 - Conversion adapter for optical connectors - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a conversion adapter for an optical connector that connects two optical connectors having different ferrule outer diameters, and in particular, for an optical connector that uses a conversion sleeve that can be aligned with high accuracy with each ferrule aligned with high accuracy. Concerning conversion adapter.
[0002]
[Prior art]
As a conventional conversion adapter for an optical connector, for example, there is one known in JP-A-9-90169. This conventional conversion adapter for an optical connector is an adapter housing in which a sleeve made of a synthetic resin, in which a step is provided on an inner diameter surface into which each of a ferrule having a large diameter and a small diameter, is fitted.
[0003]
The sleeve of such a conventional conversion adapter for an optical connector is provided with a slit (slit) in the longitudinal direction to elastically hold the ferrule, so that the ferrule is aligned without providing such a split. There is something that has been done more precisely. When the sleeve is not split, in the conventional configuration, for example, a concave groove is formed along the axial direction on the inner surface of the inner hole where each ferrule is inserted, so that air trapped in the inner hole is released to the outside. Was given.
[0004]
[Problems to be solved by the invention]
However, in the conventional optical connector conversion adapter using the above-described sleeve without split, when the sleeve is made of synthetic resin, the above-described groove portion for releasing air can be burred or dimensioned. As a result, the shaft misalignment of each ferrule increases and the connection loss increases. If the sleeve is provided with a split, air can escape to the outside through the split portion and the above-mentioned problems can be avoided. However, the provision of the split makes it difficult to align the shaft with higher accuracy.
[0005]
The present invention has been made by paying attention to the above points, and it is possible to precisely align the shaft, and reliably ensure that the air in the inner hole portion is exposed to the outside regardless of which of the large-diameter ferrule and the small-diameter ferrule is inserted first. An object of the present invention is to provide a conversion adapter for an optical connector with a small connection loss that can be missed.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a fixing member that removably fixes two optical connectors having different outer diameters of the ferrule, and a front end portion of the ferrule of each optical connector that is joined to each other. A conversion sleeve for holding an optical connector, wherein the conversion sleeve has a small diameter sleeve portion having an inner hole into which the small diameter ferrule is inserted, and an inner hole into which the large diameter ferrule is inserted, A large-diameter sleeve portion arranged so that a longitudinal central axis thereof coincides with a longitudinal central axis of the small-diameter sleeve portion, and the large-diameter sleeve portion has an inner diameter located in the vicinity of the boundary with the small-diameter sleeve portion. A predetermined portion of the side wall surface located in the vicinity of the boundary between the convex portion provided at a predetermined portion of the surface and contacting a part of the tip portion of the large-diameter ferrule to be inserted, and the small-diameter sleeve portion And a space surrounded by the tip 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. It is.
[0007]
In such a configuration, when two optical connectors having different ferrule outer diameters 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 thereof as a convex portion. The small-diameter ferrule that is held in contact and inserted into the small-diameter sleeve portion is held in a state of being joined to the distal end surface of the large-diameter ferrule. At this time, the air in the space surrounded by the tip 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 tip surface of the large diameter ferrule by the convex portion. Since it is discharged to the outside of the conversion sleeve through the gap and the through hole, it is possible to avoid poor bonding due to air mixing.
[0008]
Moreover, about the said conversion adapter for optical connectors, a large diameter sleeve part may have a recessed part in the predetermined site | part of an outer diameter surface, and it may be made to perform the gate process at the time of shaping | molding corresponding to this recessed part. With this configuration, when the conversion sleeve is formed using a mold, the gate portion corresponding to the material injection portion does not protrude outwardly from the outer diameter of the large-diameter sleeve portion by providing a recess. The gate processing at the time can be easily performed.
[0009]
Further, as a specific configuration of the optical connector conversion adapter, each optical connector may be a MU type optical connector and an SC type optical connector, or may be an LC type optical connector and an SC type optical connector.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing the overall structure of an optical connector conversion adapter according to an embodiment of the present invention. FIG. 2 is a diagram showing the arrangement of optical connectors connected using the optical connector conversion adapter of FIG.
[0011]
In each figure, the optical adapter conversion adapter 10 connects, for example, a 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, conversion sleeve 1, and MU conversion sleeve holder 2, MU conversion adapter housing 3, SC sleeve holder 4 and SC adapter housing 5 as fixing members It is prepared for.
[0012]
3A and 3B are diagrams showing a specific configuration example of the conversion sleeve 1, wherein FIG. 3A is a cross-sectional view seen from the front, FIG. 3B is a side view seen from below, and FIG. 3C is seen from the right. FIG.
[0013]
The conversion sleeve 1 shown in FIG. 3 has a small-diameter sleeve portion 11 and a large-diameter sleeve portion 12, and the sleeve portions 11 and 12 are integrally formed using a synthetic resin. As a specific material of the conversion sleeve 1, for example, a thermoplastic resin such as wholly aromatic liquid crystal polymer (LCP) or polyphenylene sulfide (PPS) can be used. However, the material of the conversion sleeve applied to the present invention is not limited to the above.
[0014]
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 such that the outer diameter of the small-diameter ferrule 50A (a ferrule of a general MU-type optical connector) is set so that a force for holding the ferrule (hereinafter referred to as insertion / extraction force) takes a required value. The diameter is preliminarily designed according to 1.249 mm). Here, in order to facilitate the insertion of the ferrule into the small diameter sleeve portion 11, a taper is formed at the opening end portion, but this taper can be omitted.
[0015]
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 holds the large-diameter ferrule 51A at a predetermined position. 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 becomes a required value. Pre-designed. Further, the large-diameter sleeve portion 12 is formed with an air bleeding rib 13 as a convex portion at a predetermined portion of the inner diameter surface located near the boundary b with the small-diameter sleeve portion 11. As shown in FIG. 3C, the air vent rib 13 is formed at three locations on the inner diameter surface, and the surface facing the inserted large diameter ferrule 51A is the tip of the large diameter ferrule 51A. Abuts the part. Further, an air vent hole 14 penetrating from the inside to the outside is formed as a through hole in the side wall surface (one portion of the lower side wall surface in FIG. 3) near the boundary b with the small diameter sleeve portion 11 in the large diameter sleeve portion 12. Has been. The shape and number of the air releasing ribs 13 and the air releasing holes 14 are not limited to the above. Also, here, a taper is formed at the open end of the large-diameter sleeve portion 12, but this taper can be omitted.
[0016]
In addition, a D-cut 15 serving as a concave portion for facilitating the gate processing at the time of forming the sleeve is provided at a predetermined portion of the outer diameter surface of the large diameter sleeve portion 12. That is, when the conversion sleeve 1 is molded by injecting material into the mold, the conversion is finally performed by cutting the gate portion 15A corresponding to the material injection portion as shown in the side view seen from below in FIG. The sleeve 1 is completed. If the gate portion 15A remaining in the conversion sleeve 1 protrudes 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 will be described later. The D-cut 15 avoids the above problems and facilitates the gate processing at the time of forming the sleeve, and lowers the outer diameter surface corresponding to the gate portion 15A to make the tip of the gate portion 15A after the cut. Is inside the outer diameter of the large diameter sleeve portion 12.
[0017]
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 inserted into the SC 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 respectively inserted into the MU conversion adapter housing 3 and the SC adapter housing 5, and the respective parts are fused, etc. A conversion adapter 10 is configured. The SC sleeve holder 4 and the SC adapter housing 5 described above can use the respective parts for SC type connectors used in existing optical connector conversion adapters.
[0018]
Next, the operation of this embodiment will be described.
FIG. 5 is an enlarged cross-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. A state before the ferrules 50A and 51A of each optical connector are inserted into the conversion sleeve 1 is shown, and (B) shows a state after the insertion.
[0019]
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-side 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 as shown in FIG. The tip of the large-diameter ferrule 51A enters along the inner diameter surface of the large-diameter sleeve portion 12 and is in contact with the three air vent ribs 13 formed near the boundary with the small-diameter sleeve portion 11. Fixed. The SC optical connector 51 inserted into the optical connector conversion adapter 10 is held by the structure of the SC sleeve holder 4 and the SC adapter housing 5.
[0020]
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, air in the space surrounded by the ferrules 50A and 51A and the inner hole of the conversion sleeve 1 passes through the air vent hole 14 formed in the large-diameter sleeve portion 12 so as to escape out of the conversion sleeve 1. Become. For this reason, the small-diameter ferrule 50A can approach the tip of the large-diameter ferrule 51A with almost no air resistance. Since the air vent path 13 is provided with the air vent rib 13, a gap is formed between the inner diameter surface of the conversion sleeve 1 and the front end surface (including the tapered portion) of the large diameter ferrule 51A. It is ensured even when the tip of the ferrule 50A is close to the tip of the large-diameter ferrule 51A. As a result, air is not trapped in the conversion sleeve 1, and the tip surfaces of the small-diameter ferrule 50A and the large-diameter ferrule 51A are surely brought into close contact with 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.
[0021]
The air discharged out of the conversion sleeve 1 through the air vent hole 14 passes through a gap along the longitudinal direction between the conversion sleeve 1, the SC sleeve holder 4 and the MU conversion sleeve holder 2, and is converted for the optical connector. It is discharged outside the adapter 10. Further, here, as shown in FIG. 6 which is an enlarged view of the range (a) of FIG. 1, the positional relationship is such that a part of the air vent hole 14 opens to the R portion of the SC sleeve holder 4. This makes air discharge more reliable and smooth. However, even in the case of the SC sleeve holder 4 without the R portion as described above, there is a gap between the conversion sleeve 1 and the sleeve holders 2 and 4 as long as they are not in close contact with each other. Existence of air is possible.
[0022]
In the above description, it is assumed that the SC-type optical connector 51 is attached before the MU-type optical connector 50, but it is of course possible to attach the MU-type optical connector 50 first. In this case, the tip of the small-diameter ferrule 50A of the MU-shaped optical connector 50 that is inserted first does not come into contact with the air vent rib 13, so that the contact surface between the air vent rib 13 and the large-diameter ferrule 51A Rather than the large-diameter ferrule 51A side. When the SC-type optical connector 51 is attached in such a state, the tip of the large-diameter ferrule 51A is fixed in contact with the air vent rib 13 while pushing down the tip of the small-diameter ferrule 50A. Even in such a series of states, a path for extracting 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 with each other.
[0023]
When removing the MU type optical connector 50 and the SC type optical connector 51 attached to the optical adapter conversion adapter 10, the conversion sleeve 1 and each sleeve holder 2, As the air flows into the conversion sleeve 1 through the gap with the air gap 4 and the air vent hole 14, each of the optical connectors 50 and 51 can be removed smoothly.
[0024]
As described above, according to the conversion adapter 10 for the optical connector, the air release rib 13 and the air release hole 14 are formed in the precision type conversion sleeve 1 that is not provided with a split. Since the air in 1 is surely discharged, it is possible to eliminate poor bonding due to air mixing. Thereby, it becomes possible to provide the conversion adapter for optical connectors which reduced the connection loss of the different diameter ferrule significantly. Further, the formation of the air vent rib 13 and the air vent 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. Furthermore, since the conversion sleeve 1 as described above can be integrally formed with a synthetic resin as a material by a mold, it can be made inexpensive, and in addition, if a D-cut 15 is provided, gate processing at the time of molding can be facilitated. It is also excellent in mass productivity. Further, since the SC sleeve holder 4 and the SC adapter housing 5 can use existing parts, it is possible to provide a conversion adapter for an optical connector at a lower price.
[0025]
In the above-described embodiment, the MU-SC conversion type adapter has been described. However, the present invention is not limited to this. For example, an LC-SC conversion type adapter that connects an LC type optical connector and an SC type optical connector can also be applied in the same manner as in the above-described embodiment.
[0026]
FIG. 7 is a view showing an example of a conversion adapter for optical connector (LC-SC conversion type) according to the present invention together with an LC type optical connector and an SC type optical connector. In addition, the same code | symbol is attached | subjected to the part same as the structure of embodiment mentioned above.
[0027]
In the optical adapter conversion adapter 10 ′ shown in FIG. 7, an LC type optical connector 52 having a relatively small diameter ferrule 52A (a ferrule diameter of a general LC type optical connector is 1.249 mm) and a relatively large diameter. The SC-type optical connector 51 having the ferrule 51A is connected. This optical connector conversion adapter 10 'differs from the MU-SC conversion type configuration described above in that the MU conversion sleeve holder 2 used in the MU-SC conversion type is omitted and the MU conversion adapter housing 3 is omitted. Instead of this, an LC conversion adapter housing 6 is provided. Therefore, the conversion sleeve 1 and the SC side configuration (SC sleeve holder 4 and SC adapter housing 5) are the same as the MU-SC conversion type.
[0028]
Also in the LC-SC conversion type adapter 10 ′ as described above, the same operation and effect as in the case of the MU-SC conversion type adapter 10 can be obtained. Further, even with adapters of different conversion types, some components such as the conversion sleeve 1 can be shared, so that it is possible to further reduce the price of the optical adapter conversion adapter.
[0029]
【The invention's effect】
As described above, the conversion adapter for an optical connector according to the present invention is provided with a convex portion and a through hole in the large-diameter sleeve portion of the split conversion sleeve, so that the air in the conversion sleeve is exposed to the outside when the optical connector is mounted. Since it is reliably released, it is possible to eliminate poor bonding due to air mixing. As a result, it is possible to provide an inexpensive optical adapter conversion adapter that can perform axial alignment of different-diameter ferrules with high accuracy and at the same time significantly reduce connection loss. Further, 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 the mass productivity is excellent.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall 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 optical connectors connected 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, in which FIG. 3A is a cross-sectional view seen from the front, FIG. 3B is a side view seen from below, and FIG. ) Is a side view seen from the right.
FIG. 4 is a diagram illustrating a D-cut of a conversion sleeve used in an embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view of a conversion sleeve in a state where a MU type optical connector and an SC type optical connector are attached to an optical connector conversion adapter according to an embodiment of the present invention.
6 is an enlarged cross-sectional view of a range (a) in FIG.
FIG. 7 is a diagram showing an example where the present invention is applied to an LC-SC conversion type adapter together with optical connectors.
[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 'Optical connector conversion adapter 11 Small diameter sleeve portion 12 Large diameter sleeve portion 13 Air release rib 14 Air vent hole 15 D cut 15A Gate part 50 MU type optical connector 51 SC type optical connector 52 LC type optical connector 50A, 51A, 52A Ferrule

Claims (4)

A fixing member that detachably fixes two optical connectors having different outer diameters of the ferrule, and a conversion sleeve that is attached to the fixing member and that holds the ferrule tip portions of the optical connectors joined to each other. In conversion adapter for optical connector,
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 a central axis in the longitudinal direction is set to a central axis in the longitudinal direction of the small-diameter sleeve portion. A large-diameter sleeve portion arranged to match,
The large-diameter sleeve portion is provided at a predetermined portion of the inner diameter surface located in the vicinity of the boundary with the small-diameter sleeve portion, and a convex portion that abuts a part of a tip portion of the large-diameter ferrule to be inserted; And a through hole formed in a predetermined part of the side wall surface located in the vicinity of the boundary with
A conversion for an optical connector, characterized in that a space surrounded by the tip surfaces of the small-diameter ferrule and the large-diameter ferrule and the internal diameter surface of the conversion sleeve is opened to the outside through the through hole. adapter. 2. The optical adapter conversion adapter according to claim 1, wherein the large-diameter sleeve portion has a concave portion at a predetermined portion of the outer diameter surface, and gate processing at the time of molding is performed corresponding to the concave portion. The optical connector conversion adapter according to claim 1, wherein each of the optical connectors is a MU type optical connector and an SC type optical connector. The optical connector conversion adapter according to claim 1, wherein each of the optical connectors is an LC type optical connector or an SC type optical connector.

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