JP2005181832A - Optical connector connecting structure and guide pin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct positioning of ferrules having slantingly ground connection end faces by a pin engaging positioning system so as not to generate axial deviation of optical fibers. <P>SOLUTION: A guide pin 16 is divided into two guide pin pieces 17 and 18 so that slanted joint surfaces 17a and 18a are provided at a middle section. The guide pin pieces 17 and 18 are respectively fitted in pin holes 3 of ferrules 2. When pressing forces are operated from both sides of opposing ferrules 2, forces A and B are reacted along opposite directions on a slantingly ground surface 2a of each ferrule 2. At that time, the slanted joint surfaces 17a and 18a of the guide pin pieces 17 and 18 are contacted, the guide pin pieces 17 and 18 respectively receive forces M and N along opposite directions and the pieces 17 and 18 respectively comes in contact with hole inner walls of opposite sides within the pin holes 3 having clearance. Thus, the guide pin 16 consisting of a pair of the guide pin pieces 17 and 18, becomes equivalent to fitting in the pin hole 3 without clearance, both ferrules 2 do not deviate in top and bottom directions and no axial deviation is generated for optical fibers 4a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical connector connection structure for performing alignment between a pair of ferrules having connection end surfaces that are obliquely polished by a pin fitting alignment method, and a guide pin used therefor.

An optical connector of the pin fitting position alignment system has a structure in which, for example, a guide pin for alignment is inserted into a pin hole provided in a ferrule made of square resin, and the ferrules are aligned.
With this type of optical connector, a so-called MT optical connector (corresponding to the F12 type multi-fiber optical connector defined in JIS C 5981) in which two opposed ferrules are sandwiched from both longitudinal sides by clips is used. The tip surface is ground into a right angle surface.
On the other hand, a so-called MPO optical connector (corresponding to an F13 type multi-core optical fiber connector defined in JIS C 5982) described later generally has a distal end surface of a ferrule 2 as in the optical connector 1 (1A) shown in FIG. Obliquely polished. An obliquely polished connection end face (obliquely polished connection end face) is denoted by 2a. In the figure, 3 is a pin hole for fitting a guide pin, 4 is an optical fiber tape to which the optical connector 1 is attached, 4a is an individual optical fiber built in the ferrule 2, and 5 is a flange portion of the ferrule 2. .

FIG. 6 shows an MPO optical connector 7 having a conventional optical connector connection structure. Generally, as shown in FIG. In this structure, the coupling 9 is provided so as to be movable, and the coupling 9 is provided on the outer periphery thereof, and the coupling 9 is inserted into the adapter 10 for connection.
In the conventional optical connector connection structure, as shown in FIG. 6, a guide pin 6 is fitted into the pin hole 3 of the ferrule 2 of one optical connector 1A, and this one guide pin 6 is inserted as shown in FIG. Are fitted into the pin holes 3 of the ferrule 2 of the mating optical connector 1'A, and the ferrules are aligned with each other. That is, the conventional optical connector connection structure is a structure in which one guide pin 6 is fitted into the pin holes 3 of both ferrules 2.
JP-A-6-54008

  When the MPO optical connector 7 is connected, as shown by an arrow P in FIG. 7 (a), a pressing force by a spring force is applied to the opposing ferrule 2 from the rear end side (see FIG. 7 ( (B) shows that both ferrules 2 are not affected by the force). Since each of the ferrules 2 has its tip end surface 2a polished obliquely, when the pressing force P is applied, the ferrules 2 tend to face in opposite directions as indicated by arrows. Originally, there is a clearance c between the guide pin 6 for alignment and the pin hole 3 of the ferrule 2 as shown in the figure, so that each ferrule 2 is shifted up and down by the force in the opposite direction generated by the inclination. However, at this time, the optical fiber 4a is misaligned as shown in FIG.

In order to reduce the optical connector connection loss, it is important to eliminate the optical fiber axis misalignment at the time of connector connection. Measures need to be taken.
As a countermeasure therefor, there is a countermeasure in which the vertical position of the optical fiber hole is slightly shifted from the center line of the pin hole, taking into account the amount of deviation up and down of the ferrule. Thereby, when each ferrule 2 shifts up and down, the axes of the optical fibers 4a coincide.
Further, in Patent Document 1, a pair of pin holes are relatively displaced by a predetermined distance within a range represented by an equation of [δ + ε + 1] μm to [δ + ε−1] μm in the acute angle direction of the inclined surface. Is adopted.

However, in each of the above measures, it is necessary to consider the clearance between the guide pin and the pin hole, and then the position of the pin hole must be set with high accuracy.
The present invention has been made based on the above background, and provides an optical connector connection structure that can easily prevent fiber axis misalignment between butted ferrules without considering the clearance between guide pins and pin holes. With the goal.

The present invention that solves the above-described problems is a pin fitting alignment method in which alignment of a pair of ferrules having a connection end surface for oblique polishing is performed by fitting a guide pin into an alignment pin hole provided on each of the ferrules. An optical connector connection structure according to
The guide pin is divided into two guide pin pieces so as to have an inclined alignment surface at the connection end face position of the opposing ferrule, and the divided guide pin pieces are respectively fitted in the pin holes of the ferrules. Features.

According to a second aspect of the present invention, in the optical connector connection structure according to the first aspect, the inclination direction of the inclined alignment surface of the guide pin piece is opposite to the inclination direction of the connection end surface of the ferrule oblique polishing.
A third aspect of the present invention is the optical connector connection structure according to the first or second aspect, wherein the angle of the inclined alignment surface of the guide pin piece is 40 ° or less.

The invention of claim 4 is a guide pin used for the optical connector connection structure of claim 1, comprising two guide pin pieces divided so as to have an inclined alignment surface at the connection end face position of the opposing ferrule. Features.

  According to the present invention, when both ferrules are brought into contact with each other by the pressing force from the rear end sides of the opposing ferrules when the optical connector is connected, as shown in FIG. The guide pin pieces 17 and 18 are also abutted. At this time, since the mating surfaces 17a and 18a are inclined, the guide pin pieces 17 and 18 are directed in opposite directions as indicated by arrows in the respective pin holes 3 having a clearance, and the inner walls of the holes on the opposite sides. To touch. In this state, the opposite surfaces (outer peripheral surfaces) of the inclined alignment surfaces 17 a and 18 a of the guide pin pieces 17 and 18 are fitted over the pin holes 3 of the two ferrules 2. Accordingly, the guide pin 16 composed of the pair of guide pin pieces 17 and 18 in contact with the inclined alignment surfaces 17a and 18a is equivalent to being fitted in the pin hole 3 without a clearance. Therefore, no vertical displacement occurs between the opposing ferrules 2, and no axial displacement occurs in each optical fiber 4 a built in each ferrule 2. As described above, the axial deviation of the optical fiber 4a can be prevented without considering the clearance between the guide pin and the pin hole, and it is extremely simple and sufficiently accurate as a measure for preventing the optical fiber axial deviation. .

  When the inclination direction of the inclined alignment surface of the guide pin piece is opposite to the inclination direction of the oblique polishing connection end face of the ferrule as in claim 2, the tip portion of the guide pin piece is fitted into the pin hole of the mating ferrule Since the length can be increased, a stable fitting state can be obtained.

  As a result of various trial manufactures and experiments on the angle of the inclined alignment surface, a stable fitting state could be obtained when the angle of the inclined alignment surface of the guide pin piece was 40 ° or less as in claim 3.

  The optical connector connection structure embodying the present invention will be described below with reference to the drawings.

1 to 5 show an optical connector connection structure according to an embodiment of the present invention. The optical connector 1 itself in the optical connector connection structure of this embodiment is the optical connector 1 shown in FIG. 5 described above, and is used for positioning in the pin holes 3 provided on the left and right of the front end surface of the ferrule 2 made of square resin. The guide pin is inserted to align the ferrules, and the front end surface of the ferrule 2 is obliquely polished. An obliquely polished connection end face (obliquely polished connection end face) is denoted by 2a. In the figure, 4 is an optical fiber tape to which the optical connector 1 is attached, 4a is an individual optical fiber built in the ferrule 2, and 5 is a collar portion of the ferrule 2. The material of the ferrule is generally PPS (polyphenylene sulfide).
In the optical connector connection structure of the embodiment, the optical connector 1 is used for an MPO optical connector (corresponding to an F13 type multi-core optical fiber connector defined in JIS C 5982) basically similar to FIG. With this, the optical connector is connected.

  1 and 2 show the ferrules 2 of the pair of optical connectors 1 and 1 'in the MPO optical connector connection. FIG. 1 is a cross-sectional view of a state before the ferrules 2 are brought into contact with each other, and FIG. FIG. 5 is a cross-sectional view showing that the ferrules 2 are merely in contact with each other without receiving a force. As shown in these drawings, the guide pin 16 fitted in the pin hole 3 of the ferrule 2 has two guide pin pieces 17 so as to have inclined alignment surfaces 17a and 18a at the connection end surface 2a position of the opposing ferrule 2. The divided guide pin pieces 17 and 18 are respectively fitted in the pin holes 3 of the ferrules 2. FIG. 4 is a perspective view of the guide pin piece 17 (18). The material of the guide pin pieces 17 and 18 is arbitrary, but stainless steel can be used, and tungsten carbide (WC), ceramic (zirconia, etc.) can also be used.

When connecting the MPO optical connector, a pair of MPO optical connectors are respectively inserted into the adapter (adapter 10 in FIG. 6) from the opposite side, and the engagement protrusions at the tip of the coupling (the engagement protrusions 9a of the coupling 9 in FIG. 6). ). At that time, since the opposing ferrules 2 are each subjected to the pressing force of the spring from the rear end side, both the ferrules 2 are elastically abutted in the adapter. At this time, the pressing force by the spring is generated between the ferrules 2 through the state shown in FIG. 2 at the moment when the opposing ferrules 2 come into contact with each other (as shown in FIG. 3). In addition, forces A and B in opposite directions act on the connection end surface 2 a of the oblique polishing of each ferrule 2.
However, at this time, since the inclined alignment surfaces 17a and 18a of the respective guide pin pieces 17 and 18 come into contact with each other, the respective guide pin pieces 17 and 18 receive forces M and N in opposite directions, respectively, and the clearance is reduced as shown in the figure. Each pin hole 3 is in contact with the opposite hole inner wall. In this state, the opposite surfaces (outer peripheral surfaces) of the inclined alignment surfaces 17 a and 18 a of the guide pin pieces 17 and 18 are fitted over the pin holes 3 of the two ferrules 2.
Therefore, the guide pin 16 composed of a pair of guide pins 17 and 18 in contact with the inclined alignment surfaces 17a and 18a is equivalent to being fitted in the pin hole 3 without a clearance, and the opposing ferrules 2 are mutually connected. No vertical deviation occurs between them, and no axial deviation occurs in each optical fiber 4 a built in each ferrule 2. As described above, the axial deviation of the optical fiber 4a can be prevented without considering the clearance between the guide pin and the pin hole, and it is extremely simple as a measure for preventing the optical fiber axial deviation, and sufficient accuracy can be secured. .

In this case, since the inclination direction of the inclined alignment surfaces 17a and 18a of the guide pin pieces 17 and 18 is opposite to the inclination direction of the connection end surface 2a of the ferrule oblique polishing, the opposite end of the guide pin pieces 17 and 18 The insertion length L with respect to the pin hole 3 of the side ferrule 2 can be made long, and therefore a stable fitting state can be obtained.
In addition, although the angle of the inclined alignment surface in the illustrated example is about 20 °, in order to obtain a stable fitting state as a result of various trial manufactures and experiments, the angle of the inclined alignment surfaces 17a and 18a should be 40 ° or less. It turns out to be appropriate.

  In the above description, the longitudinal restraint state of each guide pin piece 17, 18 has not been described, but at least one guide pin piece is fixed to the ferrule or biased by a spring. The other guide pin piece may be in a state of being freely fitted, but it is appropriate that the other guide pin piece is biased to the other side by a spring.

The optical connector connection structure of the present invention is most appropriate when applied to an optical connector corresponding to a so-called MPO optical connector, but is not necessarily limited to that case. It is also conceivable to apply to a so-called MT optical connector in which a clip is sandwiched from both sides in the longitudinal direction.
In addition, the present invention can be generally applied to an optical connector (optical ferrule) having an obliquely inclined connection end surface of a pin fitting position alignment method, and therefore, other connector housings other than the MPO housing, adapter fitting It can be used in an optical connector having a method.
Further, although the present invention is suitably applied to a multi-core optical fiber, it is not excluded that the fiber hole is applied to a single-fiber optical connector with a square ferrule.

The optical connector connection structure of one Example of this invention is shown, and is sectional drawing of the state before matching ferrules. In the optical connector connection structure of FIG. 1, it is sectional drawing of the state which the ferrules are only contacting, without receiving pressing force from both sides. In FIG. 2, it is the principal part enlarged view which showed the state in which the ferrules received the pressing force and were faced | matched. It is the perspective view which showed the guide pin fitted to one optical connector in said optical connector connection structure. It is a figure common to this invention and a prior art example, and is a perspective view of the state without a guide pin of one optical connector in an optical connector connection structure. It is a perspective view of the MPO optical connector by the conventional optical connector connection structure. The conventional optical connector connection structure is shown. (A) is a cross-sectional view of the ferrules in contact with each other without receiving a pressing force from both sides, (B) is the pressing force between the ferrules in (A). It is the principal part enlarged view which showed the state received and faced | matched.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connector 2 Ferrule 2a Connection end surface 3 of slant grinding | polishing 4 Pin hole 4 Optical fiber tape 4a Optical fiber 5 Ridge part 16 Guide pin 17, 18 Guide pin piece 17a, 18a Inclined alignment

Claims (4)

An optical connector connection structure based on a pin fitting alignment method in which alignment of a pair of ferrules having a connection end surface of oblique polishing is performed by fitting a guide pin into an alignment pin hole provided in each,
The guide pin is divided into two guide pin pieces so as to have an inclined alignment surface at the connection end face position of the opposing ferrule, and the divided guide pin pieces are respectively fitted in the pin holes of the ferrules. Optical connector connection structure.   2. The optical connector connection structure according to claim 1, wherein an inclination direction of the inclined alignment surface of the guide pin piece is opposite to an inclination direction of a connection end surface of the ferrule oblique polishing.   The optical connector connection structure according to claim 1, wherein an angle of an inclined alignment surface of the guide pin piece is 40 ° or less. The guide pin used for the optical connector connection structure according to claim 1, comprising two guide pin pieces divided so as to have an inclined alignment surface at a connection end face position of an opposing ferrule.

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