JP2002243982A - Alignment sleeve and adapter for connecting ferrules having different diameters - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that a defective product is easily produced and the optical fiber connection performance hardly becomes stable because connection loss changes according to the turning posture of the alignment sleeve, and the alignment sleeve is mounted turnably, thereby the limit value of concentricity tolerance is restricted small in the case where the axial center of the first and second cylindrical part of the alignment sleeve of an adapter for connecting ferrules having different diameters are inclined relatively. SOLUTION: The adapter 1 for connecting ferrules having different diameters has the alignment sleeve 10 and a sleeve holder 11 for mounting the alignment sleeve 10. The flange part of the alignment sleeve 10 is mounted in the fitting hole 17 of a holder wall 14 in a fitted state. The alignment sleeve 10 is turned around the axial center to determine a phase position where the connection loss of optical fiber connection is minimalized. The alignment sleeve 10 is mounted in the sleeve holder 11 at the phase position, and its turning is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment sleeve for connecting different diameter ferrules and an adapter for connecting different diameter ferrules, and more particularly, to a rotation posture (phase position) of the alignment sleeve with respect to a sleeve holder in one of a plurality of postures. It is related to what can be set.

[0002]

2. Description of the Related Art Conventionally, as described in Japanese Patent Application Laid-Open No. 2000-39539, when optical fibers are connected to each other via an optical connector and a connection adapter, the optical connector at the end of the optical fiber can be detached from both sides of the connection adapter. And inside the alignment sleeve in the connection adapter, the end faces of the pair of connection ferrules and the pair of optical fibers are concentrically butted to connect. Each optical connector is provided with a connection ferrule through which an optical fiber passes through an axis, and inside the connection adapter, an alignment sleeve for inserting the connection ferrule and a sleeve holder for holding the alignment sleeve are provided. In the alignment sleeve, the axes of both connection ferrules are concentrically positioned with high precision and the two optical fibers are concentrically butted.

In this case, in particular, in the case of a single mode optical fiber, in order to align the end faces of both connection ferrules to be connected and to connect the end faces directly to each other, the axes of both connection ferrules are positioned with high precision. There is a need. A connection ferrule with an outer diameter of 2.5 mmφ is applied to the F04 type single-core optical fiber connector specified by JIS C 5973, and a 1.25 mmφ outer diameter is applied to the F14 type optical fiber connector specified by JIS C 5983. A connection ferrule is applied.

A connecting ferrule having an outer diameter of 2.5 mmφ and an outer diameter of 1.
The connection adapter for connecting the connection ferrule of 25 mmφ is provided with a different diameter ferrule connection alignment sleeve for connecting the connection ferrule of 2.5 mmφ and the connection ferrule of 1.25 mmφ. This alignment sleeve for connecting ferrules of different diameters has a first cylindrical portion for inserting a connection ferrule of 2.5 mmφ and a second cylindrical portion for inserting a connection ferrule of 1.25 mmφ, which are provided concentrically and in series. Also, a flange portion for fixing the alignment sleeve to the sleeve holder is formed at a middle portion in the length direction of the alignment sleeve.

[0005]

The alignment sleeve for connecting ferrules having different diameters is manufactured by cutting a metal wire such as phosphor bronze with a high-precision machine tool. Therefore, it is difficult to form the axis of the first cylindrical portion and the axis of the second cylindrical portion of the different-diameter alignment sleeve completely parallel to each other. Therefore, when the axes are parallel, the connection loss of the optical fiber is the same regardless of the rotational posture (phase position around the axis) of the alignment sleeve, but when the axes are not parallel, 2.
When connecting the connection ferrule of 5 mmφ and the connection ferrule of 1.25 mmφ, the concentricity of both connection ferrules changes and the connection loss of the optical fiber also changes depending on the rotation posture of the alignment sleeve.

[0006] Because the conventional alignment sleeve is rotatably mounted on the sleeve holder, the alignment sleeve is rotated around its axis and in any phase position, the error does not exceed the predetermined concentricity tolerance. We needed to keep it down. As a result, the limit value of the concentricity tolerance has to be set small due to the error (relative inclination) of the parallelism between the axes of the first and second cylindrical portions. Is expensive, the connection loss of the optical fiber is large, the yield of the alignment sleeve and the connection adapter is poor, and when the alignment sleeve is rotated, the connection state of the optical fiber fluctuates and the repeatability is poor. Problems.

An object of the present invention is to provide an alignment sleeve for connecting ferrules of different diameters and a connection adapter for connecting ferrules of different diameters, which can increase the limit value of the concentricity tolerance, reduce the connection loss of the optical fiber, and increase the repetition accuracy. It is to provide.

[0008]

An alignment sleeve for connecting ferrules of different diameters according to claim 1 is mounted on a sleeve holder of a connection adapter to connect two connection ferrules having different diameters in a butt state. A sleeve including a series of first and second cylindrical portions for internally fitting connection ferrules having different diameters, and a flange portion located near a boundary between the first and second cylindrical portions; A positioning rotation restricting portion that enables the alignment sleeve to be selectively positioned at a plurality of phase positions rotated around the axis with respect to the holder,
It is characterized in that it is formed on the flange portion.

In the step of assembling the connection adapter, the alignment sleeve is temporarily positioned and mounted on the sleeve holder, and the connection ferrules are inserted into the first and second cylindrical portions, respectively, and they are optically temporarily connected. In this state, while passing light through a pair of optical fibers and measuring the connection loss, the alignment sleeve is selectively and sequentially positioned at a plurality of phase positions rotated around its axis, and the connection is performed. Optimal by finding the phase position (optimal phase position) where the loss is minimized, assembling the alignment sleeve to the sleeve holder so that the optimal phase position is reached, and restricting the rotation via the positioning rotation restricting part formed on the flange part. Hold in phase position.

According to a second aspect of the present invention, there is provided an adapter for connecting ferrules having different diameters, an alignment sleeve for connecting two connection ferrules having different diameters in a butt state, a sleeve holder for mounting and holding the alignment sleeve,
In the adapter for connecting ferrules having different diameters provided with these alignment sleeves and a case for accommodating the sleeve holder, a flange formed at an intermediate portion in the length direction of the alignment sleeve and a flange of the alignment sleeve are fitted. A fitting hole formed in the holder wall of the sleeve holder, the flange portion and the fitting hole are selected at a plurality of phase positions where the alignment sleeve is rotated around the axis with respect to the sleeve holder. It is characterized in that it is configured so as to be able to be positioned uniformly.

At the stage of assembling the connection adapter, the alignment sleeve is mounted on the sleeve holder, the flange portion is fitted inside the fitting hole of the holder wall of the sleeve holder, and connection ferrules having different diameters are inserted into the alignment sleeve. And temporarily connect them optically. In this state, while passing light through a pair of optical fibers and measuring the connection loss, the alignment sleeve is selectively and sequentially positioned at a plurality of phase positions rotated around its axis, and the connection is performed. A phase position where the loss is minimized (optimal phase position) is found, and the connection adapter is used in a state where the alignment sleeve is positioned on the sleeve holder so as to be at the optimal phase position.

According to a third aspect of the present invention, in the adapter of the second aspect, the flange portion has a circular outer shape, and a plurality of engagement recesses are formed on the outer peripheral surface of the flange portion at appropriate circumferential intervals. Formed on the inner periphery of the fitting hole,
An engagement protrusion capable of engaging with the engagement recess is formed. The sleeve holder is formed by selectively engaging the engagement protrusion formed on the inner periphery of the fitting hole of the holder wall of the sleeve holder with the plurality of engagement recesses formed on the outer periphery of the flange. The rotation position can be regulated by positioning the phase position of the alignment sleeve with respect to.

[0013]

Embodiments of the present invention will be described below. As shown in FIG. 1, an adapter 1 for connecting ferrules of different diameters is used to connect an optical fiber 2 and an optical fiber 4, and a small-diameter optical connector 3 at the end of the optical fiber 2 and its ferrule (not shown). ) Is fitted inside the left half of the adapter 1 for connecting a different diameter ferrule, and the large diameter optical connector 5 at the end of the optical fiber 4 and its ferrule (not shown) are connected to the right side of the adapter 1 for connecting a different diameter ferrule. The two optical connectors 3 and 5 are connected by the adapter 1 for connecting ferrules of different diameters, and the optical fibers 2 and 4 are optically connected.

As shown in FIG. 2, the adapter 1 comprises an alignment sleeve 10 for connecting ferrules of different diameters, a sleeve holder 11 for mounting the alignment sleeve 10, and cases 12, 13 for accommodating these. Have been. The sleeve holder 11 has a holder wall 14.
And an engagement cylindrical portion 15 with which the optical connector 5 is engaged, and a pair of engagement pieces 16 integrally formed of a synthetic resin material.
A substantially circular fitting hole 17 for fixing and holding the flange portion 33 of the alignment sleeve 10 is formed in the holder wall 14.

A sleeve holder 11 with the alignment sleeve 10 mounted thereon is inserted into the case 12, and a pair of engagement pieces 16 of the sleeve holder 11 is engaged with an engagement portion of the case 12, thereby providing an alignment sleeve. 10
And the sleeve holder 11 are attached to the case 12 in a retaining shape. A connector connecting member (not shown) that engages with the optical connector 3 is fitted inside the case 13, and the flange 18 of the case 12 and the flange 19 of the case 13 are positioned via the positioning pins 20. The flanges 18 and 19 are engaged holes 2
1 and the engagement protrusion 22.

Next, as shown in FIG. 3, the alignment sleeve 10 includes a first cylindrical portion 31 for tightly fitting a small-diameter connection ferrule (outer diameter: 1.25 mm) of the optical connector 3, and an optical connector. 5 large diameter connection ferrule (outer diameter 2.
(50 mm) are integrally formed by cutting a phosphor bronze wire into a second cylindrical portion 32 for tightly fitting the inside and a flange portion 33 having a larger diameter than the second cylindrical portion 32. First
The second cylindrical portions 31 and 32 are formed concentrically and in series, and the second cylindrical portion 32 is formed to be approximately twice as long as the first cylindrical portion 31. The flange portion 33 includes the first and second cylindrical portions 3.
It is formed in the vicinity of the boundary between 1, 32, that is, in the middle part in the length direction. The alignment sleeve 10 can be made of a metal material other than phosphor bronze or a synthetic resin material.

The first ferrule of the optical connector 3 is fitted in the first cylindrical portion 31 so as to be elastically held therein.
The cylindrical portion 31 is formed with a pair of notched elongated holes 34 extending from its free end toward the second cylindrical portion 32, and a pair of notched lengths is formed in the middle portion of the first cylindrical portion 31 in the longitudinal direction. A pair of elongated holes 35 having a phase position different from that of the hole 34 by 90 degrees are formed. Similarly, the second cylindrical portion 32 is provided with a first cylindrical portion 3 from its free end so that the connection ferrule of the optical connector 5 can be elastically held by being fitted inside the second cylindrical portion 32.
A pair of notched elongated holes 36 extending to two sides and a pair of elongated holes 37 located at the same phase position as the notched elongated holes 36 and on the flange portion 33 side are formed. These notched elongated holes 36 and elongated holes are formed. 1 whose phase position differs from 37 by 90 degrees and is somewhat longer in the axial direction
A pair of elongated holes 38 are formed.

The flange portion 33 and the fitting hole 17 are provided in order to selectively position the alignment sleeve 10 with respect to the sleeve holder 11 at a plurality of phase positions rotated around the axis thereof. It is configured as follows. The flange portion 33 is formed in an outer circular shape, and serves as a positioning rotation regulating portion 39 for selectively positioning the alignment sleeve 10 with respect to the sleeve holder 11 at a plurality of phase positions. Four engagement concave portions 40 are formed in a square groove shape at four equally spaced positions on the circumference of
On the holder wall 14 of the sleeve holder 22, one engagement projection 41 projecting from the peripheral surface of the fitting hole 17 and one engagement projection that can be selectively engaged with the four engagement recesses 40. A part 41 is formed.

Next, the operation and effects of the alignment sleeve 10 for connecting different diameter ferrules and the adapter 1 for connecting different diameter ferrules described above will be described. FIG. 4 shows that the optical connector 2 is attached to the alignment sleeve 10 in the adapter 1.
4 shows a state in which the connection ferrules 3a and 5a are inserted and the optical fibers 2 and 4 are connected. In the single mode optical fibers 2 and 4, the concentricity tolerance of the axial center is 0.5 μm.
m or less. If the deviation of the concentricity tolerance or the parallelism of the axis increases, the connection loss increases, and such an alignment sleeve 10 and the adapter 1 are defective.

In the alignment sleeve 10, the first
The axis 31a of the cylindrical portion 31 and the axis 32a of the second cylindrical portion 32
Are parallel and the concentricity tolerance is about 0.5 μm or less. However, the concentricity tolerance between the two axes 31a and 32a at the boundary between the first and second cylindrical portions 31 and 32 is 0.5 μm.
Even in the following cases, in many cases, the other is slightly inclined with respect to one of the two axes 31a and 32a. In such a case, the connection ferrule 3 is rotated by rotating the alignment sleeve 10 with respect to the connection ferrules 3a and 5a.
a of the optical fiber 2 at the center of the a and the connection ferrule 5
It is possible to change the relative positional relationship between the axes of the optical fibers 4 at the axis center of a.

Therefore, when assembling the alignment sleeve 10 inside the adapter 1, the connection ferrule 3 is attached to the first and second cylindrical portions 31, 32 of the alignment sleeve 10.
In the state where the optical fibers 2 and 4 are connected by inserting the optical fibers 2 and 5a, the alignment sleeve 10 is rotated around its axis while measuring the connection loss by passing the light through the optical fibers 2 and 4, and the connection loss is measured. Find a phase position at which is approximately minimized. In this case, the connection loss is measured while the flange portion 33 of the alignment sleeve 10 is fitted into the fitting hole 17, and the engagement protrusion 41 is sequentially engaged with the four engagement recesses 40. Is found, and when assembling the alignment sleeve 10 to the sleeve holder 11, the alignment sleeve 10 is mounted on the sleeve holder 11 so that the connection loss has the minimum phase position.

In this way, the alignment sleeve 10 can be assembled to the sleeve holder 11 so as to be at the phase position where the connection loss is substantially minimized, and thereafter, the rotation can be restricted from the phase position. In addition to improving the connection loss associated with the optical fiber connection in the above, the limit value of the concentricity tolerance of the first and second cylindrical portions 31 and 32 of the alignment sleeve 10 can be relaxed to reduce the manufacturing cost of the alignment sleeve 10, The occurrence rate of defective products of the adapter 1 for connecting different diameter ferrules and the alignment sleeve 10 for connecting different diameter ferrules can be remarkably reduced, and the reliability (repeatability) of the connection of the optical fiber in the alignment sleeve 10 can be ensured. Can be.

Next, a modified example in which the alignment sleeve 10 and the sleeve holder 11 are partially modified will be briefly described. 1) The number of the engagement projections 41 provided in the fitting hole 17 of the sleeve holder 11 is not necessarily one, and four engagement projections 41 may be provided so as to correspond to the engagement recesses 40.
It is also possible to provide one or three. In addition, the engagement recess 4
The number of 0 is not limited to four, but may be three or five or more.

2) As shown in FIG. 5, the flange portion 33A of the alignment sleeve 10 is formed in a substantially circular outer shape, and one or a plurality of engaging protrusions 42 (corresponding to a positioning rotation restricting portion) are formed on the outer peripheral portion thereof. Is formed, and a plurality of engagement concave portions are formed at a plurality of equally circumferential positions on the outer peripheral portion of the fitting hole 17 of the holder wall 14 of the sleeve holder 11.

3) As shown in FIG. 6, flat portions 43 (corresponding to positioning rotation restricting portions) are formed on both sides of the flange portion 33B of the alignment sleeve 10, and fitted to the holder wall 14 of the sleeve holder 11. The hole 17 is also formed in the same shape as the flange portion 33B, so that the alignment sleeve 10 can be selectively positioned at two phase positions with respect to the fitting hole 17.

4) As shown in FIG. 7, the flange portion 33C of the alignment sleeve 10 is formed in a shape having a square outer shape, and the fitting hole 17 of the sleeve holder 11 is formed into a square outer shape in which the flange portion 33C is fitted. Form into shape.
The alignment sleeve 10 can be selectively positioned at an optimum position among the four phase positions to regulate the rotation.

5) As shown in FIG. 8, the flange portion 33D of the alignment sleeve 10 is formed in a shape having a regular hexagonal outer shape, and the fitting hole 17 of the sleeve holder 11 is formed into a regular hexagonal shape in which the flange portion 33D fits. It is formed in the shape of
The alignment sleeve 10 can be selectively positioned at an optimum position among the six phase positions to restrict the rotation. In addition, without departing from the spirit of the present invention,
Various changes can be added to the above-described embodiment and the modified embodiment.

[0028]

According to the alignment sleeve for connecting ferrules having different diameters according to the first aspect, a plurality of phase positions are selected on the flange portion of the alignment sleeve with respect to the sleeve holder by rotating the alignment sleeve around its axis. Since the positioning rotation restricting part that can be positioned uniformly is provided, at the stage of assembling the connection adapter, a phase position where the connection loss is minimized is found, and the alignment sleeve is attached to the sleeve holder so that the phase position is reached. ,
After that, the rotation of the alignment sleeve can be regulated, the connection loss when connecting the optical fiber can be reduced, the limit value of the concentricity tolerance of the alignment sleeve can be relaxed, and the production cost can be reduced. The occurrence rate of defective products of the sleeve and the connection adapter can be reduced, and the reliability does not decrease due to the rotation of the alignment sleeve.

According to the adapter for connecting ferrules having different diameters according to the second aspect, a flange portion is formed at an intermediate portion in the length direction of the alignment sleeve, and the flange portion of the alignment sleeve is fitted to the holder wall of the sleeve holder so as to be fitted therein. A fitting hole is formed, and the flange portion and the fitting hole are configured so as to be selectively positioned at a plurality of phase positions where the alignment sleeve is rotated around its axis with respect to the sleeve holder. At the stage of assembling the adapter, among the plurality of phase positions of the alignment sleeve with respect to the sleeve holder, the alignment sleeve is positioned at a phase position at which the connection loss of the optical fiber is as small as possible, and the alignment sleeve is mounted on the sleeve holder. It can be regulated to reduce connection loss when connecting optical fibers. Can, it is possible to reduce the production cost by loosening the limit value of the concentricity tolerance of the alignment sleeve,
The occurrence rate of defective products of the alignment sleeve and the connection adapter can be reduced, and the reliability does not decrease due to the rotation of the alignment sleeve.

According to the third aspect of the present invention, the flange portion has a circular outer shape, and a plurality of engagement recesses are formed on the outer peripheral surface of the flange portion at appropriate circumferential intervals. Since an engagement protrusion which can be engaged with the engagement concave portion is formed on the inner peripheral portion of the mating hole, the engagement protrusion of the sleeve holder is formed by a plurality of engagement protrusions formed on the outer peripheral surface of the flange portion. The phase position of the alignment sleeve with respect to the sleeve holder can be easily determined by engaging with any of the engagement recesses. Since the engagement concave portion is formed in the flange portion having the outer circular shape of the alignment sleeve, it is advantageous in reducing the material cost of the alignment sleeve in the stage of manufacturing the alignment sleeve.

[Brief description of the drawings]

FIG. 1 is a plan view of an adapter for connecting ferrules of different diameters and an optical connector according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a different diameter ferrule connection adapter.

FIG. 3 is a perspective view of an alignment sleeve.

FIG. 4 is a sectional view of an alignment sleeve.

FIG. 5 is an end view of an alignment sleeve according to a modification.

FIG. 6 is an end view of an alignment sleeve according to another modification.

FIG. 7 is an end view of an alignment sleeve according to another modification.

FIG. 8 is an end view of an alignment sleeve according to another modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adapter for connecting ferrules of different diameters 10 Alignment sleeve 11 Sleeve holder 17 Fitting hole 31 First cylindrical part 32 Second cylindrical part 33, 33A to 33D Flange part 39 Positioning rotation restricting part 40 Engagement concave part 41 Engagement projection

Claims (3)

[Claims] An alignment sleeve for connecting two connection ferrules having different diameters in a butt state in a state of being mounted on a sleeve holder of a connection adapter, wherein an alignment sleeve for internally fitting connection ferrules having different diameters is provided. A plurality of first and second cylindrical portions, and a flange portion located near a boundary between the first and second cylindrical portions, wherein the alignment sleeve is rotated about the axis with respect to the sleeve holder. An alignment sleeve for connecting ferrules of different diameters, wherein a rotation restricting portion for positioning that can be selectively positioned at the phase position is formed on the flange portion. 2. An alignment sleeve for connecting two connection ferrules having different diameters in a butt state,
In a different diameter ferrule connection adapter comprising a sleeve holder for mounting and holding the alignment sleeve, and a case for accommodating the alignment sleeve and the sleeve holder, a flange portion formed at an intermediate portion in a length direction of the alignment sleeve And a fitting hole formed in the holder wall of the sleeve holder for fitting the flange portion of the alignment sleeve into the fitting holder, wherein the flange portion and the fitting hole move the alignment sleeve with respect to the sleeve holder. An adapter for connecting ferrules having different diameters, wherein said adapter is configured to be selectively positioned at a plurality of phase positions rotated around a center. 3. The flange portion has a circular outer shape, and a plurality of engagement recesses are formed on the outer peripheral surface of the flange portion at appropriate intervals in the circumferential direction. The adapter for connecting ferrules of different diameters according to claim 2, wherein an engagement protrusion that can be engaged with the recess is formed.