JP2006078676A - In-situ connection optical connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and highly precisely connect optical fibers in-situ. <P>SOLUTION: The in-situ connection optical connector is equipped with: a ferrule inserting hole 17 which is formed in one end of the base 12 to guide a ferrule in an SC type plug to be connected; optical fiber inserting holes 14 (14a, 14b) which are formed penetratingly from the other end of the base 12 to the ferrule inserting hole 17 coaxially therewith and which are inserted with an optical fiber to be mounted in-situ; and an adhesive filling hole 15 which is opened in communication with the optical fiber inserting holes 14 and which is for filling an adhesive for fixing the optical fiber inserted in the optical fiber inserting hole 14. In addition, the optical fiber inserting holes 14 are properly formed in a size larger than the outer diameter of the optical fiber so that, when the adhesive is filled in the adhesive filling hole 15, the adhesive is spread inside the optical fiber inserting holes 14 while roughly evenly wetting the entire circumference of the optical fiber and that the adhesive makes the optical fiber radially stuck with a nearly uniform adhesive power. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an on-site optical connector used when connecting an optical fiber in the field.

  Conventionally, a connector is generally used to connect optical fibers on site. However, such a connector has a very complicated structure, and assembling requires a large-scale device including a resin supply device as a material for the connector housing, and it is possible to carry in the device to the site. It was often difficult.

Further, since high assembly accuracy is required for assembling the connector, it is difficult to improve the work efficiency.
For this reason, there has been a demand for the development of a technique that allows easy connection without requiring a large-scale device on site.

  In view of this, an on-site optical connector configured as shown in FIG. 7 has been proposed (see Patent Document 1). The field-attached optical connector 100 has an end portion 103 of an optical fiber 102 placed on an upper surface 104 of a base 105, and is positioned so that a tip surface of the end portion 103 is flush with a joining end surface 118. A centering part 110 is provided.

  Further, a lid 106 is attached to the base 105, and an adhesive injection hole 131 is formed on the distal end side of the lid 106 so as to communicate from the outer surface 128 to the fiber clamping region 129. The adhesive injection hole 131 is for fixing the optical fiber 102 by injecting an ultraviolet curable adhesive into the vicinity of the aligning portion 110 when the base 105 and the lid 106 are integrated.

  Then, with the lid body 106 being detached from the base 105, the end 103 at the tip of the optical fiber 102 from which the covering material has been peeled is inserted into the V groove 111. When the tip of the end 103 can be inserted into the rear end of the V-groove 111, the base 105 and the lid 106 are fitted together and the optical fiber 102 is pushed.

Thereafter, an ultraviolet curable adhesive is injected into the fiber holding region 129 from the adhesive injection hole 131, and the base 105 is irradiated by covering the periphery of the aligning portion 110 and the optical fiber 102 with the ultraviolet curable adhesive and irradiating the ultraviolet rays. The lid 106 and the optical fiber 102 are integrated.
JP-A-8-262272

  However, in the above configuration, the optical fiber 102 is inserted, the lid body 106 is fitted, the ends are aligned, and the state is maintained in a state where the base 105 and the lid body 106 are not integrated. There is a problem that it is difficult to improve workability because the ultraviolet curable adhesive must be injected and solidified.

  That is, it is preferable to insert the optical fiber 102 along the V-groove 111 because the optical fiber 102 is positioned by the insertion operation. However, when the lid 106 is fitted in this state, the optical fiber 102 moves. , The desired V-shaped groove 111 may be removed. Therefore, when fitting the lid body 106, it is necessary to carefully work to prevent this from occurring.

  Even if the lid 106 can be properly fitted, the lid 106 is not integrated with the base 105, so that the optical fiber 102 may come off when the hand shakes. Therefore, it is necessary to perform work so that such camera shake does not occur.

  Further, when the lid 106 is fitted, it is difficult to notice even if dust or the like is caught in the fitting portion, and if an ultraviolet curable adhesive is injected in such a state, the positioning of the optical fiber becomes insufficient. As a result, the transmission efficiency of the optical signal may be reduced.

  In addition, although the curing rate of the UV curable adhesive is generally high, the portion that is not irradiated with UV does not cure, so the UV curable adhesive is injected into the vicinity of the end portion 103 of the optical fiber from which the coating material has been peeled off. It will be cured. Accordingly, the adhesive force directly acts on the optical fiber from which the coating material has been peeled off. However, since the portion is thin and fragile, there is a possibility that breakage or the like may occur due to a single external force.

  Of course, it is also possible to bond the portion where the coating material is not peeled off with an ultraviolet curable adhesive, but in this case, the portion which is shaded by the coating material (for example, the optical fiber 102 and the base 105 in FIG. 7). It is difficult to solidify the ultraviolet curable adhesive of the ultraviolet curable adhesive injected into the area between the two.

  In addition, when the adhesive easily flows (when the viscosity is low or when the adhesive is injected while being pressurized), there is a problem that the adhesive is likely to adhere to the end portion to be joined.

  Furthermore, the ultraviolet curable adhesive often undergoes a volume change during curing and often has a large viscosity. For this reason, as described above, when the shape of the base side and the lid side in contact with the optical fiber is different, the spreading property of the ultraviolet curable adhesive is poor, and it is difficult to wrap around between the optical fiber and the base. When processing is performed, non-uniform adhesive force acts in the radial direction of the optical fiber (mainly adhesive force acting mainly in the opening direction of the adhesive injection hole 131), and the optical fiber Could cause misalignment.

  Accordingly, an object of the present invention is to provide an on-site connector that can easily and accurately attach an optical fiber to the field.

  In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a base forming a main body part of a field-mounted connector, and a ferrule insertion that is formed at one end of the base and guides insertion of a ferrule in a connected SC-type plug. From the other end of the base to the ferrule insertion hole, the optical fiber insertion hole through which the optical fiber to be attached in-situ is inserted is communicated with the optical fiber insertion hole. And an adhesive injection hole into which an adhesive for fixing the optical fiber inserted into the optical fiber insertion hole is injected, and the adhesive is injected into the adhesive injection hole In addition, the optical fiber insertion hole is formed so that the adhesive spreads in the optical fiber insertion hole while wetting the entire circumference of the optical fiber substantially uniformly, and bonds the optical fiber in the radial direction with a substantially uniform force. It is obtained by forming appropriately larger size than the outer diameter of the optical fiber dimensions.

  As a result, when the optical fiber is inserted into the optical fiber insertion hole and the adhesive is injected from the adhesive injection hole, the adhesive spreads and solidifies while wetting the entire circumference of the optical fiber substantially uniformly. Bonding is performed with a substantially uniform adhesive force in the radial direction. Therefore, even if the diameter of the optical fiber insertion hole differs from that of the optical fiber due to processing margins, etc., the optical fiber axis and the ferrule insertion hole axis can be easily connected with high accuracy. Is possible.

  According to a second aspect of the present invention, the optical fiber insertion hole is a two-stage hole whose hole diameter decreases in the optical fiber insertion direction, and the large-diameter optical fiber insertion hole is in a state where the coating material is not peeled off. The outer diameter of the optical fiber is set to a size appropriately larger than the outer diameter of the optical fiber, communicates with the adhesive injection hole, and the side wall of the adhesive injection hole on the ferrule insertion hole side is smooth toward the ferrule insertion hole side. The optical fiber insertion hole on the small-diameter side is covered with an adhesive supply reservoir when the adhesive spreads into the optical fiber insertion hole. Light that is set to a size that is appropriately larger than the outer diameter of the optical fiber from which the material has been peeled off, and that has a taper that smoothly reduces the step when moving from the large diameter side to the small diameter side. Insert the fiber It is intended to de.

As a result, when the optical fiber is inserted into the optical fiber insertion hole, the tapered portion guides the insertion of the optical fiber, so that the end face of the optical fiber is hardly damaged during the insertion.
In addition, since the taper part in the adhesive injection hole forms an adhesive supply reservoir, sufficient adhesion is achieved to spread the optical fiber insertion hole while wetting the entire circumference of the optical fiber where the coating material is not peeled off substantially uniformly. The agent can be supplied smoothly, and the optical fiber can be bonded in the radial direction with a substantially uniform force.

  According to the present invention, an optical fiber insertion hole formed coaxially with the ferrule insertion hole is formed, an adhesive injection hole communicating with the optical fiber insertion hole is formed, and the adhesive is removed from the adhesive injection hole. When injected, this adhesive spreads and solidifies while wetting the entire circumference of the optical fiber substantially uniformly, so that the optical fiber can be fixed with a substantially uniform adhesive force in the radial direction of the optical fiber. In addition, it is possible to align the optical fiber axis with the axis of the ferrule insertion hole with high accuracy.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a field-installed connector according to the present invention, FIG. 1 (a) is a top view, FIG. 1 (b) is a cross-sectional view taken along line AA in FIG. 1 (a), and FIG. These are the side views seen from arrow B in Drawing 1 (a). FIG. 2 is a partially broken perspective view of the field-attached connector. FIG. 3 is a structural view of a holder for maintaining the engagement between the field-attached connector and an SC (Single Core) type plug, FIG. 3 (a) is a top view thereof, and FIG. 3 (b) is FIG. 3 (a). 3C is a side view in the direction of arrow C, FIG. 3C is a cross-sectional view taken along the line CC in FIG. 3B, and FIG. 4 is a partial cross-sectional view when these are assembled.

  As is well known, an optical fiber is composed of a core having a diameter of 10 to 50 μm and a clad of about 125 μm surrounding the core, and a covering material is covered thereon. In connecting optical fibers, it is necessary that the guided optical signals pass through the contact surface with high efficiency by properly aligning and contacting the cores of the optical fibers facing each other.

  In the present invention, it is assumed that one optical fiber is set in an existing SC-type plug. This SC type plug is provided with a ferrule having an optical fiber inserted into the shaft center, an optical fiber attached in-situ is brought into contact with one end face of the ferrule, and the optical fiber is already connected to the other end face It has become.

Therefore, as an on-site connector, it is attached to an SC-type plug, and at that time, the optical fiber core of the ferrule and the optical fiber core on the on-site connector side are brought into contact with each other with a desired accuracy Is required.
Of course, in order to maintain this contact state even after contact, it is necessary to fix the optical fiber on the site-mounted connector side to the field-mounted connector.

  From this point of view, in the field-attached connector 10 according to the present invention, the sleeve portion 11 having a ferrule insertion hole 17 that guides the insertion of the ferrule in the SC-type plug at the tip of the base 12 that is substantially rectangular and forms the main body portion. These are formed by a synthetic resin having the same thermal expansion as that of glass.

  The base 12 communicates with the optical fiber insertion hole 14 through which the optical fiber is inserted through the ferrule insertion hole 17, the holder engagement protrusion 16 for engaging with the holder 30, and the optical fiber insertion hole 14. An adhesive injection hole 15 or the like for injecting an adhesive for fixing the optical fiber inserted into the optical fiber insertion hole 14 is provided.

  In the connection of the optical fiber, the coating material on the distal end side (connection end side) of the optical fiber is peeled and abutted with the optical fiber inserted along the axis of the ferrule in the SC type plug. For this reason, the optical fiber insertion hole 14 is set to the size of the optical fiber from which the coating material is peeled off in the middle.

  Actually, the size is appropriately set in consideration of the thermal expansion of the base 12 and the like, the processing margin, the diffusibility of the adhesive, and the like. Hereinafter, the optical fiber insertion hole 14 through which the optical fiber from which the covering material has been peeled is inserted is referred to as a connection hole 14a, and the optical fiber insertion hole 14 up to the connection hole 14a is referred to as an introduction hole 14b.

  In a state where the coating material of the optical fiber is peeled off, the diameter is as thin as 125 μm, for example. Therefore, the connection hole 14a for positioning the optical fiber is formed with a high accuracy of about +1 μm in consideration of the thermal expansion, processing margin, adhesive diffusibility and the like described above with respect to the diameter of the optical fiber.

  Therefore, if the stepped portion 14c when moving from the introduction hole 14b to the connecting hole 14a is stepped, the tip of the inserted optical fiber may abut against the stepped surface of the stepped portion 14c, without being noticed. If the insertion is continued, the optical fiber may be broken or the end surface polished by PC (Physical Contact) may be damaged.

  Therefore, in the present invention, the stepped surface of the stepped portion 14c when moving from the introducing hole 14b to the connecting hole 14a is tapered so that the optical fiber can be smoothly guided to the connecting hole 14a.

  Such a tapered portion is also formed on the inlet 14d of the introduction hole 14b and the side wall 14e on the side of the connection hole 14a in the adhesive injection hole 15 to help the insertion of the optical fiber and be broken or damaged. Does not occur.

  The adhesive injection hole 15 is a hole formed to a depth that is substantially half the depth of the optical fiber insertion hole 14, so that the adhesive can be poured from here and the optical fiber inserted into the optical fiber insertion hole 14 can be fixed to the base 12. It has become. The reason why the adhesive injection hole 15 is formed to a depth that is substantially half the depth of the optical fiber insertion hole 14 is to leave the function of guiding the optical fiber to be inserted.

  Adhesives such as UV curable adhesives and instant adhesives such as instant adhesives can be used as adhesives, but as will be described later, adhesives are low in viscosity and cure in a short time. Is preferred.

When the viscosity of the adhesive is reduced, the entire circumference of the optical fiber 33 is substantially uniformly wetted by the adhesive 34 and solidifies as shown in FIG.
On the other hand, when the viscosity of the adhesive 34 is large, as shown in FIG. 6, only part of the side surface of the optical fiber 33 is likely to get wet with the adhesive 34 and solidify.

  5 (a) and 6 (a) are partial cross-sectional views of the on-site connector when the SC type plug including the adhesive injection hole 15 and the optical fiber insertion hole 14 is mounted, FIG. 5 (b). 6 (b) is an enlarged view, and FIGS. 5 (c) and 6 (c) are DD cross-sectional views and EE cross-sectional views in FIGS. 5 (b) and 6 (b). FIG.

At this time, the number 21 is an optical fiber inserted into the ferrule 35 including the core 21a and the clad 21b, and the number 33 is the above-mentioned optical fiber attached on the site, which includes the core 33a, the clad 33b, and the covering material 33c. ing.
Reference numerals f1 and f2 indicate radial forces that the optical fiber 33 receives from the adhesive 34.

  As described above, generally, the adhesive 34 often changes in volume when solidified. Therefore, as shown in FIG. 6, when the adhesive is attached only to a part of the side surface of the optical fiber, the optical fiber 33 is bonded in the direction of the adhesive 34 by receiving the adhesive force f2. As a result, the axis P1 of the optical fiber 33 is displaced from the axis P2 of the ferrule 35, and the degree of adhesion between the core 33a and the core 21b is reduced.

  Since this volume change is proportional to the amount of the adhesive 34, for example, as described in the prior art in FIG. 7, when the optical fiber is guided by the V-shaped groove 111 and pressed by the lid 106. Since the support shape of the optical fiber is different between the V-groove 111 and the lid body 106, the amount of adhesive differs between the V-groove 111 and the lid body 106, and the volume change amount varies accordingly. Therefore, a deviation between the axis of the optical fiber to be bonded and the axis of the ferrule is likely to occur.

  On the other hand, in the present invention, the optical fiber insertion hole 14 has a similar shape to the optical fiber 33, the viscosity of the adhesive 34 is low, and the dimension of the adhesive 34 is substantially the entire circumference of the optical fiber 33 due to capillary action or the like. The inside of the introduction hole 14b is spread while being evenly wetted.

  In the present invention, a capillary phenomenon is assumed as a driving force for the adhesive 34 to expand in the introduction hole 14b. However, the present invention is not limited to this. In the case of the capillary phenomenon, it is necessary to set the inner diameter of the optical fiber insertion hole 14 to such a dimension that the capillary phenomenon effectively occurs while taking into consideration the processing margin, thermal expansion, insertion property of the optical fiber 33, and the like.

  Further, when an instantaneous adhesive is used as the adhesive 34, irradiation with ultraviolet rays or the like is not required, so that the adhesive 34 spreads between the optical fiber 33 and the base 12 from which the covering material 33 c has not been peeled. , Function as an adhesive.

  As a result, the optical fiber 33 is pulled with a uniform adhesive force f1 in the radial direction, and the coincidence between the axis of the optical fiber 33 and the axis of the optical fiber 21 as shown in FIG. As a result, the degree of adhesion between the core 33a and the core 21a can be easily increased.

  In the state where the adhesive 34 is not solidified, the axis of the optical fiber 33 and the axis of the optical fiber insertion hole 14 coincide, but this is because the surface tension of the adhesive 34 acts uniformly in the radial direction. It is the result.

As shown in FIGS. 3 and 4, the holder 30 includes a plug engaging portion 38 that engages with an existing SC-type plug 44 and a connector engaging portion 39 to which the on-site connector 10 is attached.
In the plug engaging portion 38, an engaging claw 41 that engages with an engaging groove 40 (see FIG. 4) provided in the SC plug 44 is provided, and the SC portion 44 is provided in the case portion. A plug positioning groove 42 into which the rotational position regulating rib 43 is inserted is provided.
On the other hand, the connector engaging portion 39 is provided with a connector engaging claw 45 into which the holder engaging protrusion 16 is fitted.

  Using the on-site connector 10 having such a configuration, an on-site operation of an optical fiber will be described. First, the covering material 33 c at the tip of the optical fiber 33 whose end face is clean-cut is peeled off and inserted into the optical fiber insertion hole 14. At this time, since the introduction hole 14b and the connection hole 14a are tapered, the tip of the optical fiber 33 abuts on the stepped portion 14c or the like, and the end surface is not damaged, and the optical fiber can be easily obtained. 33 can be inserted.

  The tip position of the inserted optical fiber is positioned by inserting a known tip positioning jig from the tip of the connector and bringing the tip of the optical fiber into contact with the jig.

  When the insertion of the optical fiber 33 is completed, the adhesive 34 is injected from the adhesive injection hole 15. Then, the adhesive 34 spreads in the introduction hole 14b due to a capillary phenomenon or the like, and at that time, the entire circumference of the optical fiber 33 spreads and solidifies substantially uniformly.

  At this time, since the side wall 14e of the adhesive injection hole 15 is also tapered, a large amount of the adhesive 34 is stored in the tapered portion, and as an adhesive supply pool when the adhesive 34 spreads into the introduction hole 14b. By acting, it becomes possible for the adhesive to sufficiently spread into the introduction hole 14b.

  Then, due to the surface tension of the adhesive 34 that has spread in the introduction hole 14b in this way, the axis of the optical fiber 33 automatically coincides with the axis of the introduction hole 14b, and the axis of the optical fiber 33 is aligned. It becomes possible to match the axis of the optical fiber in the ferrule inserted into the ferrule insertion hole 17 with high accuracy.

  When the adhesive 34 is solidified, the on-site attaching operation is completed, and the on-site connector 10 is attached to the holder 30 and the SC-type plug 44 is attached as shown in FIG.

  Since the portion where the optical fiber 33 is bonded and fixed is a portion where the covering material is not peeled off, even if an external force such as a pulling force is applied to the optical fiber 33, this force is applied to the covering material, Since the optical fiber 33 is not directly applied to the optical fiber 33, the optical fiber 33 is hardly damaged by breakage or the like, and the reliability can be improved.

It is a figure which shows the structure of the field attachment connector which concerns on this invention. FIG. 2 is a partially broken perspective view of the on-site connector shown in FIG. 1. It is a figure which shows the structure of the holder used when connecting a field attachment connector to SC type | mold plug. It is a fragmentary sectional view at the time of connecting a field installation connector and SC type plug using a holder. It is a figure for demonstrating the condition of an optical fiber when the substantially uniform adhesive force arises in the radial direction of an optical fiber. It is a figure for demonstrating the condition of the optical fiber when the nonuniform adhesive force arises in the radial direction of an optical fiber. It is an exploded view of the field attachment connector applied to description of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Connector 11 Sleeve part 12 Base 14a Connection hole 14b Introduction hole 14c Step part 14d Inlet 14e Side wall 14 Optical fiber insertion hole 15 Adhesive injection hole 16 Holder engagement protrusion 17 Ferrule insertion hole 21 Number 33 Optical fiber 33a Core 33b Clad 33c Covering material 34 Adhesive 35 Ferrule

Claims (2)

A base that forms the body of the on-site connector,
A ferrule insertion hole that is formed at one end of the base and guides the insertion of the ferrule in the SC-type plug to be connected;
From the other end of the base to the ferrule insertion hole, penetrated coaxially with the ferrule insertion hole, and an optical fiber insertion hole into which an optical fiber attached in the field is inserted,
An adhesive injection hole that is opened to communicate with the optical fiber insertion hole and into which an adhesive for fixing the optical fiber inserted into the optical fiber insertion hole is injected; and
When the adhesive is injected into the adhesive injection hole, the adhesive spreads in the optical fiber insertion hole while substantially uniformly wetting the entire circumference of the optical fiber, and the optical fiber is approximately in the radial direction. An on-site optical connector characterized in that the size of the optical fiber insertion hole is appropriately larger than the outer diameter of the optical fiber so as to be bonded with a uniform force. The optical fiber insertion hole is a two-stage hole whose hole diameter decreases in the insertion direction of the optical fiber,
The optical fiber insertion hole on the large-diameter side is set to a size that is appropriately larger than the outer diameter of the optical fiber in which the coating material is not peeled, and communicates with the adhesive injection hole, and the adhesive injection hole The side wall on the ferrule insertion hole side is formed into a taper shape that smoothly reduces toward the ferrule insertion hole side, and the insertion of the optical fiber is guided, and the adhesive is connected to the optical fiber insertion hole. The adhesive supply pool when spreading inside,
The optical fiber insertion hole on the small diameter side is set to a size that is appropriately larger than the outer diameter of the optical fiber from which the coating material has been peeled off, and the stepped portion when moving from the large diameter side to the small diameter side is smoothly reduced. 2. The field-attached optical connector according to claim 1, wherein the optical fiber connector is formed in a taper shape to guide insertion of the optical fiber from which the covering material has been peeled off.

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