JP2005031237A - Mechanical splice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a mechanical splice capable of assuring stable matching accuracy at the mutual splicing part of optical fibers by pressing down individual optical fibers uniformly in performing multi-fiber splicing. <P>SOLUTION: In a pressure plate 27 which presses down optical fibers 25, 26 placed on the V grooves 22 of a substrate 23, an opening window 27a is formed at a position corresponding to the mutual splicing place 24 of a plurality of optical fibers 25, 26 laid on the V grooves 22, a holding member 29 which presses down the mutual splicing place 24 of the optical fibers 25, 26 is fit and attached to the opening window 27a to be attachable to and detachable from the window, and the holding member 29 is brought into contact with a clamping spring 33 with the projected part 29a which is formed at the center of an upper face. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical splice for connecting optical fibers, and more particularly to an improvement for obtaining a stable connection by pressing each optical fiber with an equal pressing force when multi-fiber connection is made.
[0002]
[Prior art]
In the communication field, optical fibers capable of high-speed and large-capacity transmission have become the mainstream of transmission lines, and most medium- and long-distance trunk lines have already been replaced with optical fiber cables instead of conventional metal cables. Furthermore, efforts are being made at a rapid pace toward the realization of an optical subscriber transmission system that is going to use optical fiber for the transmission lines to homes several years later.
[0003]
Conventionally, fusion connection or connection by a connector has been performed for butt connection between optical fibers.
However, fusion splicing is highly reliable because it melts the abutment surface of the optical fiber, but it takes time to reinforce after connection, the fusion device is expensive, and the fusion device is activated. The problem is that a power source is required for the operation.
In addition, the connection using the connector requires time and effort for mounting the connector on the end of each optical fiber, the connector itself costs considerably, the connector increases the bulk of the connection, and the storage of the connection is large. The need to secure storage space has become a problem.
[0004]
Therefore, a mechanical splice 51 shown in FIG. 3 has been proposed as an apparatus that can easily and inexpensively realize a butt connection between optical fibers.
The mechanical splice 51 includes a substrate 55 on which a V-groove 54 for positioning the core wire 53 of the optical fiber 52 is formed, a presser plate 56 that presses and fixes the core wire 53 from above, and these substrates 55. And a clamp spring 57 that clamps and holds the presser plate 56 from above and below.
When connecting the optical fiber 52 to the V-groove 54, as shown in FIG. 3 (b), the wedge 59 is inserted into the wedge insertion groove 58 between the substrate 55 and the holding plate 56 and spread. After inserting the optical fiber 52 from both ends into the gap and butting the core wires 53 with each other, the wedge 59 is pulled out as shown in FIG. 3 (c), so that it is inserted into the V groove 54 by the restoring force of the clamp spring 57. The optical fiber 52 is pressed and fixed by the holding plate 56, and the optical fibers abutted on the V groove 54 are connected to each other (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-318836 [0006]
The mechanical splice 51 shown in FIG. 3 is for a single core, but there is also a four-fiber mechanical splice 61 as shown in FIG. In this mechanical splice 61, V grooves 62 are formed in four rows, and each core wire 63 is inserted into the V groove 62, respectively.
[0007]
By the way, in recent years, due to an increase in the amount of information to be transmitted, for example, cables using 8-core optical fibers are frequently used for main trunk lines and the like. For this reason, a mechanical splice used to connect optical fibers is required to have a multi-core structure capable of connecting four-core optical fibers or eight-core optical fibers.
However, in the case of a mechanical splice in which the number of V grooves formed on the substrate is simply increased as shown in FIG. It is difficult to press with a uniform pressing force, and there is a possibility that inconveniences such as a decrease in alignment accuracy may occur at some optical fiber joints due to variations in pressing force.
[0008]
Therefore, a mechanical splice shown in FIG. 5 has been proposed.
This mechanical splice 1 includes a substrate 4 in which V-grooves 3 for supporting and aligning the optical fibers 2 and 7 facing each other are aligned in multiple rows, and optical fibers 2 and 7 inserted in the V-groove 3. A pressing plate 5 having a flat surface for pressing, and a clamp spring 6 for holding the optical fiber 2 and 7 by sandwiching the substrate 4 and the pressing plate 5, and the substrate 4 inside the clamping spring 6 A convex portion 11 extending along the optical axis direction is formed on the presser plate 5 side, and the presser plate 5 further has a surface on the side opposite to the surface in contact with the optical fibers 2 and 7 inserted from the arrangement width of the optical fibers. A recess 12 having a narrow width is formed along the optical axis direction, and a flat spacer substrate 14 is provided between the press plate 5 and the clamp spring 6 in which the recess 12 is formed (for example, , See Patent Document 2).
The point that the optical fibers 2 and 7 are inserted into the V-groove 3 in a state where the wedge is inserted into the wedge-inserting groove 8 formed on the abutting surface of the substrate 4 and the holding plate 5 is the same as the conventional one.
[0009]
[Patent Document 2]
Japanese Patent Laid-Open No. 2001-201668
In the above configuration, the elastic urging force that the clamp spring 6 acts on the substrate 4 and the presser plate 5 is improved so as to be concentrated on the narrow width by the convex portion 11, and it is thin and easily deformed. A thick spacer substrate 14 is interposed on the presser plate 5, and the elastic biasing force of the clamp spring 6 is indirectly transmitted through the spacer substrate 14, so that the presser plate 5 is bent. Be regulated. As a result, even when multi-core optical fibers having four or more cores are butt-connected, it is possible to achieve uniform pressing on each optical fiber and suppress a decrease in matching accuracy at the connection portion between the optical fibers. .
[0011]
[Problems to be solved by the invention]
However, in the mechanical splice 1 disclosed in Patent Document 2, the increase in the number of components due to the addition of the spacer substrate 14 not only causes an increase in cost, but the mechanical splice 1 is equivalent to the thickness of the added spacer substrate 14. There was also a problem that the thickness dimension increased and the mechanical splice was increased in size.
Moreover, in the mechanical splice of Patent Document 2, when an optical fiber is inserted into the V-groove 3 of the substrate 4, since the joint where the tip of each optical fiber abuts cannot be seen from the outside, the actual alignment state is confirmed. Even if some of the optical fibers have poor alignment, the connection work may be completed without confirmation.
[0012]
The present invention has been made in view of the above-described problems, and an object of the present invention is to hold down each optical fiber evenly without using a spacer substrate that causes an increase in thickness when multi-core connection is made. In addition, it is possible to prevent variations in alignment accuracy at the connection portion between optical fibers, and thus to provide a mechanical splice that can achieve high-accuracy alignment while preventing an increase in size of the apparatus. Therefore, it is possible to provide a mechanical splice in which a stable connection can be easily obtained by appropriate alignment because the connection operation can be performed while visually confirming the alignment state of the optical fibers in the section.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a mechanical splice according to the present invention includes a substrate on which a plurality of V-grooves are formed, and a press plate that holds the optical fiber superimposed on the upper surface of the substrate. And a clamp spring that presses and holds the substrate and the presser plate in close contact with each other, and is attached to the presser plate at a position corresponding to a connection portion between a plurality of optical fibers disposed opposite to each other in the V-groove. An opening window formed, and a gripping member that is detachably fitted to the opening window and presses each optical fiber at the connection site with an urging force of the clamp spring,
On the upper surface of the gripping member, a convex portion with which the clamp spring makes elastic contact is projected and formed along the V-groove direction.
[0014]
In the mechanical splice configured as described above, the gripping member is provided in a nested structure with respect to the presser plate, and even if it secures a sufficient thickness that does not easily cause deformation due to the elastic biasing force from the clamp spring. Most of the thickness is received by the thickness of the presser plate to be inserted, and the increase in the thickness of the apparatus can be suppressed to a very small amount as compared with the conventional correspondence in which the spacer substrate is provided.
In addition, the gripping member receives the elastic biasing force of the clamp spring in a concentrated manner by a convex portion protruding at the center of the width, and the received elastic biasing force is around the connection part where each optical fiber is abutted with each other. Therefore, the unreasonable dispersion of the elastic urging force acting from the clamp spring is suppressed, and each optical fiber can be pressed evenly.
[0015]
The width dimension of the convex portion provided on the upper surface of the gripping member has a great influence on the size of the uniform pressing area on the contact surface of the gripping member with the optical fiber.
Therefore, several types of gripping members are prepared in which the width dimension of the convex portion that contacts the clamp spring is changed in accordance with the number of connecting cores, and the entire number of connecting cores is determined in accordance with the number of connecting cores. It is preferable to select and use a convex portion that can obtain a uniform pressing force.
In this way, even when the number of connecting cores is changed, it is possible to ensure a uniform pressing force at the connecting portion of each optical fiber only by changing the gripping member.
[0016]
The mechanical splice according to claim 2 is characterized in that, in order to achieve the above object, in the mechanical splice according to claim 1, the gripping member is further a transparent member.
[0017]
In the mechanical splice configured as described above, the connection operation can be performed while visually confirming the alignment state of the optical fibers at the connection site.
[0018]
The mechanical splice according to claim 3 is characterized in that, in order to achieve the above object, in the mechanical splice according to claim 1 or 2, the gripping member further has a lens action. .
[0019]
In the mechanical splice configured as described above, the alignment state of the connecting portions of the optical fibers can be enlarged and visually recognized by the lens action, so that it is easy to find a slight misalignment or the like.
[0020]
Preferably, as described in claim 4, a clamp spring that presses the gripping member is provided independently of a clamp spring that presses the presser plate.
[0021]
In this case, for example, when the gripping member to be used is changed in accordance with the change in the number of connecting cores, etc., the clamp plate of the gripping member is held while the presser plate is fixed to the substrate with the dedicated clamp spring. Only the gripping member can be easily replaced by simply removing it.
Furthermore, even when it is desired to change the spring pressure necessary for pressing the gripping member, the clamp spring on the presser plate side does not need to be changed.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a mechanical splice according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
1 and 2 show an embodiment of a mechanical splice according to the invention. FIG. 1 is a perspective view in an assembled state, and FIG. 2 is a cross-sectional view of a main part.
[0023]
The mechanical splice 21 of this embodiment is installed in the V-groove 22 so as to overlap with the substrate 23 on which a plurality of V-grooves 22 for aligning the optical fibers 26 and 26 to be connected are formed, and on the upper surface of the substrate. A plurality of optical fibers 25 that are provided with a pressing plate 27 that holds the optical fibers 25 and 26 and a clamp spring 31 that presses and holds the substrate 23 and the pressing plate 27 in close contact with each other, and are disposed to face each other in the V groove 22. 26, an opening window 27a formed on the holding plate 27 at a position corresponding to the connection part 24 between each other, and each light of the connection part 24 by a biasing force by a dedicated clamp spring 33 that is detachably fitted to the opening window 27a. And a gripping member 29 that presses the fiber.
[0024]
On the upper surface of the holding member 29, a convex portion 29a with which the clamp spring 33 is elastically contacted is formed so as to protrude along the V-groove direction of the substrate 23. In addition, the lower surface of the gripping member 29 that is in contact with the optical fibers 25 and 26 is finished to be a flat surface. The convex portion 29a is provided over the entire length of the gripping member 29 along the V-groove direction.
In the case of the present embodiment, the holding member 29 is appropriately formed of a transparent member made of a resin material or the like.
[0025]
Further, the gripping member 29 is devised in the shape and the like of the convex portion 29a so as to have a lens action for enlarging the connecting portion of the optical fibers 25 and 26.
[0026]
Furthermore, in the case of the present embodiment, the clamp spring 33 that presses the holding member 29 is provided independently of the clamp spring 31 that presses the presser plate 27, and an elastic biasing force according to the number of connecting cores. Several types are available.
[0027]
The substrate 23 has a rectangular parallelepiped shape elongated in the axial direction of the optical fibers 25 and 26 to be connected, and a plurality of V grooves 22 are formed on the upper surface of the substrate 23 along the axial direction of the optical fibers 25 and 26.
[0028]
The clamp spring 31 is formed by bending a plate material such as spring steel into a U-shaped cross section with the substrate 23 and the holding plate 27 sandwiched from above and below.
Similarly to the clamp spring 31, the clamp spring 33 is formed by bending a plate material such as spring steel into a U-shaped cross section sandwiching the substrate 23 and the gripping member 29 from above and below.
[0029]
As shown in the figure, a wedge insertion groove 36 for inserting a wedge is provided at the end of the abutting surface between the substrate 23 and the holding plate 27. By inserting the wedge into the wedge insertion groove 36, the space between the substrate 23 and the holding plate 27 is opened against the urging force of the clamp spring 31, and the optical fibers 25 and 26 are inserted into and removed from the fiber placement portions 23c. The point is the same as the conventional mechanical splice.
[0030]
In the mechanical splice 21 described above, the gripping member 29 is provided in a nested structure with respect to the presser plate 27, and it may be possible to secure a sufficient thickness that does not easily cause deformation due to the elastic biasing force from the clamp spring 33. Most of the thickness is received by the thickness of the presser plate 27 to be inserted, and the increase in thickness as a device can be suppressed to a very small amount as compared with the conventional correspondence in which the spacer substrate is provided.
In addition, the holding member 29 receives the elastic biasing force of the clamp spring 33 in a concentrated manner by the convex portion 29a projecting at the center of the width thereof, and the received elastic biasing force is connected to each optical fiber. Since the action is limited to the specified range around the portion 24, the undue dispersion of the elastic biasing force acting from the clamp spring is suppressed, and each optical fiber can be pressed evenly.
[0031]
Therefore, when using multi-fiber connection, the optical fibers 25 and 26 are pressed evenly without using a spacer substrate that causes an increase in the thickness dimension, so that the alignment accuracy at the connection portion 24 between the optical fibers 25 and 26 can be improved. Since variations can be prevented, high-precision matching can be obtained while preventing an increase in the size of the apparatus.
[0032]
The width dimension W (see FIG. 2) of the convex portion 29a provided on the upper surface of the gripping member 29 has a great influence on the size of the uniform pressing area on the contact surface of the gripping member 29 with the optical fiber.
Accordingly, the gripping member 29 is prepared in several types in which the width dimension or the like of the convex portion 29a that contacts the clamp spring is changed according to the number of connecting cores. It is preferable to select and use one having a convex portion 29a that can obtain a uniform pressing force.
By doing in this way, even when changing the number of connecting cores, it is possible to ensure an equal pressing force on the connecting portion of each optical fiber simply by changing the gripping member 29. A stable connection with proper matching can be realized.
[0033]
In addition, since the gripping member 29 of the present embodiment is formed of a transparent member, the connection work can be performed while visually confirming the alignment state of the optical fibers 25 and 26 in the connection portion 24. Therefore, it is possible to easily obtain a stable connection by proper matching while preventing oversight of misalignment of the optical fiber.
[0034]
In addition, since the gripping member 29 of the present embodiment has a lens action, the alignment state of the connection portion 24 between the optical fibers can be enlarged and visually recognized. Therefore, it is easy to find a slight misalignment and the like. Improvements can further facilitate stable connections with proper alignment.
[0035]
Furthermore, in the present embodiment, the clamp spring 33 that presses the gripping member 29 is provided independently of the clamp spring 31 that presses the presser plate 27, so that it can be used, for example, when the number of connecting cores is changed. When the holding member 29 to be replaced is replaced, the holding plate 27 is simply fixed to the substrate with the exclusive clamp spring 31 and the holding member 29 is simply replaced by simply removing the clamping spring 33 of the holding member 29. The troublesome disassembly work can be minimized.
Furthermore, even when it is desired to change the spring pressure required for pressing the gripping member 29, the clamp spring 31 on the presser plate 27 side does not need to be changed, and the improvement is facilitated.
[0036]
【The invention's effect】
According to the mechanical splice of the present invention, the gripping member that presses the connection portion between the optical fibers is provided in a nested structure with respect to the presser plate, and has a sufficient thickness that is not easily deformed by the elastic biasing force from the clamp spring. Even if the thickness is ensured, most of the thickness is received by the thickness of the presser plate to be inserted, and the increase in the thickness of the device can be suppressed to a very small amount compared with the conventional correspondence in which the spacer substrate is provided. it can.
Further, the gripping member receives the elastic biasing force of the clamp spring in a concentrated manner by the convex portion projecting at the center of the width, and the received elastic biasing force is received at the connection portion where the optical fibers are abutted with each other. Since the action is limited to the peripheral specified range, the undue dispersion of the elastic biasing force acting from the clamp spring is suppressed, and each optical fiber can be pressed evenly.
Therefore, even in the case of multi-fiber connection, high-precision alignment can be realized while preventing an increase in the size of the apparatus, and if the gripping member is made of a transparent member or has a lens action, the optical fibers can be connected to each other. It is possible to proceed with the connection work while visually confirming the alignment state, and it is possible to easily obtain a stable connection with proper alignment.
Furthermore, if the gripping member is configured to be pressed by a dedicated clamp spring, when the gripping member is replaced when the number of connecting cores is changed, the clamp spring on the presser plate side remains as it is. Only by removing the clamp spring of the member, only the gripping member can be easily replaced, and the troublesome disassembling work can be minimized.
[Brief description of the drawings]
FIG. 1 is a perspective view of an embodiment of a mechanical splice according to the present invention.
FIG. 2 is a cross-sectional view in which a gripping member of the mechanical splice shown in FIG. 1 is mounted.
FIGS. 3A and 3B are explanatory views of the structure of a conventional mechanical splice, where FIG. 3A is a perspective view and a cross-sectional view before inserting an optical fiber, and FIG. 3B is a wedge insertion between a mechanical splice substrate and a presser plate; (C) is a perspective view and a cross-sectional view of a fixed state of the optical fiber inserted on the substrate.
FIG. 4 is a cross-sectional view showing the configuration of still another conventional mechanical splice.
FIG. 5 is a cross-sectional view of a conventional improved mechanical splice.
[Explanation of symbols]
21 Mechanical splice 23 Substrate 23b V-groove 23c Fiber placement portion 25, 26 Optical fiber 27 Press plate 27a Opening window 29 Holding member 31, 33 Clamp spring 36 Wedge insertion groove

Claims (4)

A substrate on which a plurality of V-grooves are formed, a pressing plate that is superimposed on the upper surface of the substrate and presses the optical fiber, and a clamp spring that presses and holds the substrate and the pressing plate in close contact with each other. An opening window formed in the presser plate at a position corresponding to a connection portion between a plurality of optical fibers arranged opposite to each other in the groove, and a detachable fitting and mounting on the opening window, and an urging force by the clamp spring A gripping member that presses each optical fiber at the connection site,
A mechanical splice characterized in that a convex portion with which the clamp spring makes elastic contact is formed on the upper surface of the gripping member so as to protrude along the V-groove direction. The mechanical splice according to claim 1, wherein the gripping member is a transparent member. The mechanical splice according to claim 1 or 2, wherein the gripping member has a lens action. The mechanical splice according to any one of claims 1 to 3, wherein a clamp spring that presses the gripping member is provided independently of a clamp spring that presses the presser plate.

Images