JP2014071175A - Reinforcement sleeve, reinforcement method of optical fiber connection section, and reinforcement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement sleeve or the like that is small in size and has high reinforcement workability of a connection section.SOLUTION: A thermofusion member 5 is a cylindrical member, and has a substantially circular cross section. The thermofusion member 5 is made of ethylene vinyl acetate based resin, for example. Preferably, the thermofusion component 5 is fused at a temperature lower than a heat shrinkable temperature of a heat shrinkable tube 3. A reinforcement core material 7 as a tensile strength body is a rod-like member. The reinforcement core material 7 is made of steel, carbon, glass, or the like. The reinforcement core material 7 is inserted into the thermofusion member 5, namely covered with the thermofusion member 5. In a reinforcement sleeve 1, the reinforcement core material 7 covered with the thermofusion member 5 can be inserted into or removed from the heat shrinkable tube 3 (arrow A direction in Figure). The outer diameter of the thermofusion member 5 is slightly shorter than the inner diameter of the heat-shrinkable tube 3.

Description

  The present invention relates to a reinforcing sleeve, a method for reinforcing a connecting portion of an optical fiber core wire, and a reinforcing structure.

  Conventionally, for example, when optical cords are connected to each other, the optical fibers accommodated therein are fusion-connected. Such a fusion splicing portion is reinforced by providing a reinforcing member.

  Various such reinforcing structures have been devised. For example, there is an optical connector in which a fusion splicing portion is covered with a protective sleeve and the protective sleeve itself is accommodated in the connector (Patent Document 1).

  Also, the fusion part reinforcement sleeve having the thermoplastic resin is moved to the inner side that has been extrapolated to the optical cord, and the fusion part is reinforced by covering the fusion splice between the optical fiber with the built-in ferrule and the optical fiber of the optical cord. A fusion splicing portion that is a heat shrinkable tube while accommodating a fusion splicing portion in the sleeve, heating the fusion bonding portion reinforcing sleeve and the thermoplastic resin, and heating and melting the thermoplastic resin inside the fusion bonding portion reinforcing sleeve. There is a method of heat shrinking (Patent Document 2).

  Further, there is a method in which, for example, a cut is provided in the longitudinal direction of the reinforcing member, a tensile body is provided inside the heat-meltable reinforcing member, and a heat-shrinkable tube is disposed on the outer periphery to heat (Patent Document 3).

JP 2008-197622 A JP 2011-107590 A JP 59-28113 A

  FIGS. 7A and 7B are diagrams showing a reinforcing process of a connecting portion between optical fibers when a reinforcing sleeve 100 is used as an example of a conventional reinforcing sleeve, FIG. 7A is a front view, and FIG. It is the HH sectional view taken on the line of Fig.7 (a). The optical cord 109 is provided with a tensile member (not shown) and an optical fiber core wire 113 inside the jacket 111. The optical fiber core wire 113 is a glass optical fiber 115a covered with a resin coating portion. The reinforcing sleeve 100 is configured by providing a reinforcing core member 107 and a heat melting tube 105 inside a heat shrinkable tube 103. The optical fiber core wire 113 is provided so as to penetrate the heat melting tube 105.

  First, as shown in FIG. 7A, at the end of the optical cord 109, the outer cover 111 is removed with a length that allows the reinforcing sleeve 100 to be retracted, and furthermore, the glass optical fibers can be fusion-spliced. The glass optical fibers 115a and 115b are exposed to a certain extent. The reinforcing sleeve 100 is retracted to the outer periphery of the optical fiber core wire 113. Further, the glass optical fibers 115a and 115b are opposed to each other. In this state, by discharging from the electrode 119, the glass optical fibers 115a and 115b are fused.

  In this state, the glass optical fiber 115b fixed to the ferrule 117 and the glass optical fiber 115a of the optical cord 109 are fused and connected. FIG. 8A is a diagram showing a state where the glass optical fibers 115 a and 115 b are fused at the connection portion 121.

  Next, as shown in FIG. 8B, the reinforcing sleeve 100 is moved to the outer periphery of the connecting portion 121 (arrow I in the figure). By doing so, the glass optical fibers 115 a and 115 b and the connection portion 121 can be covered with the reinforcing sleeve 100.

  In this state, the reinforcing sleeve 100 is heated as shown in FIG. As a result, the heat-shrinkable tube contracts, and the reinforcing sleeve 100 comes into close contact with the glass optical fibers 115a and 115b.

  FIG.9 (b) is the JJ sectional view taken on the line of Fig.9 (a). The melting temperature of the internal heat melting tube is lower than the heating temperature of the heat shrinkable tube. For this reason, as shown in FIG. 9B, after heating, the reinforcing core member 107 and the glass optical fibers 115a and 115b are integrated by the heat melting member and the heat shrinkable tube. Thus, the reinforcement of the connecting portion between the glass optical fibers by the reinforcing sleeve 100 is completed.

  However, in such a reinforcing structure, as described above, it is necessary to retract the reinforcing sleeve 100 when the glass optical fibers are fused. Therefore, it is necessary to remove the jacket 111 at the end of the optical cord 109 with a length that can retract the reinforcing sleeve 100. Therefore, the length of the outer cover removal at the connecting portion becomes longer, which causes the connector to become larger.

  This also applies to the method disclosed in Patent Document 1, and since the fusion part is accommodated in the connector, there is a problem that the length of the connector is increased depending on the length of the fusion sleeve. This is because, as described above, in addition to the design for accommodating the fusion sleeve in the connector, it is necessary to lengthen the outer circumference of the optical cord by the length of the fusion sleeve when creating the connector.

  Moreover, by using a fusion sleeve thicker than the jacket of the optical cord as in the method of Patent Document 2, the fusion sleeve can be inserted through the optical cord without peeling off the jacket. However, for example, in the above-described example, if the diameter of the reinforcing sleeve 100 is increased so that it can be retracted to the outer periphery of the jacket 111, the shrinkage allowance of the heat-shrinkable tube is insufficient, and the connection portion can be covered completely. There is a risk of disappearing. Also, normally, when assembling the connector, the outer diameter of the reinforcing sleeve needs to be smaller than the inner diameter of the frame part of the connector. Therefore, the use of a thick fusion sleeve increases the size of the connector itself. For this reason, it is difficult to reduce the size of the optical connector.

  Further, in Patent Document 3, a fusion sleeve is set immediately before fusion so that dust or the like does not enter the inside of the heat fusion tube. It is difficult to insert into the notch. Moreover, there exists an operation | work which accommodates a fusion | melting member and a tension body in a shrinkable tube simultaneously, and workability | operativity is bad.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a reinforcing sleeve and the like that are small in size and excellent in the reinforcing workability of a connecting portion.

  In order to achieve the above-described object, the first invention is a reinforcing sleeve for reinforcing a connecting portion of a glass optical fiber, which is a heat-melting member, a reinforcing core member inserted through the heat-melting member, and the reinforcement A core material and a heat shrinkable tube into which the heat melting member can be inserted and removed, and the reinforcing core coated with the heat melting member on the heat shrinkable tube with a glass optical fiber inserted into the heat shrinkable tube. It is a reinforcement sleeve characterized by being able to insert a material.

  As described above, the reinforcing core member and the heat melting member can be inserted into and removed from the heat shrinkable tube. Therefore, in a state where it is inserted through a jacket having a large outer diameter, the heat-melting member or the like is removed, and the heat-melting member and the reinforcing core material are inserted into the heat-shrinkable tube only when necessary. For this reason, it is not necessary to enlarge the outer diameter of the heat shrinkable tube excessively. Moreover, since the heat-shrinkable tube can be retracted to the outer periphery of the outer jacket, the length of the outer jacket removed at the connection portion can be shortened.

  Moreover, since the reinforcing core material which is a tensile body is covered with the heat melting member, the reinforcing core material and the glass optical fiber do not come into direct contact with each other. Therefore, it is possible to prevent the glass optical fiber or the like from being damaged during the connection work.

  Further, at least one end of the heat shrinkable tube may have a tapered shape with an enlarged inner diameter. A groove may be formed in the longitudinal direction on the inner surface of the heat shrinkable tube. The cross-sectional shape of the heat shrinkable tube may be elliptical.

  By doing in this way, it becomes easy to insert a reinforcement core material and a heat fusion member with respect to a heat contraction tube.

  A second invention is a method for reinforcing an optical fiber connecting portion using the reinforcing sleeve according to the first invention, wherein a predetermined length of glass is removed at the end of the optical cord by removing a jacket of a predetermined length. In the state where the optical fiber is exposed and the heat-shrinkable tube is disposed on the outer periphery of the outer sheath of the optical cord, the glass optical fiber to be connected and the glass optical fiber of the optical cord are fused and connected, The heat shrinkable tube is moved so as to cover the connection portion between the glass optical fibers, the reinforcing core material covered with the heat melting member is inserted into the heat shrinkable tube, and the heat shrinkable tube and the heat melting are inserted. And heating the member to shrink the heat-shrinkable tube and melt the heat-melting member, thereby integrating the reinforcing core member and the glass optical fiber connecting portion. Part is a method of reinforcement.

  According to the second invention, since the heat shrinkable tube is disposed on the outer periphery of the outer jacket in a state where the reinforcing core member and the heat melting member are removed, it is not necessary to excessively increase the inner diameter of the heat shrinkable tube. The removal length can be shortened. Further, since the reinforcing core material covered with the heat melting member is inserted after moving to the position covering the connecting portion, the reinforcing core material and the glass optical fiber do not come into direct contact. Moreover, a glass optical fiber and a core material can be integrated by heating in this state.

  3rd invention is the reinforcement structure of the optical fiber connection part using the reinforcement sleeve concerning 1st invention, Comprising: The jacket of predetermined length was removed in the edge part of an optical cord, and glass of predetermined length The optical fiber is exposed and the glass optical fiber fixed to the ferrule and the glass optical fiber of the optical cord are fusion-connected, and the connection portion between the glass optical fibers is integrated with the reinforcing core member by the heat melting member. The distance from the end portion of the heat shrinkable tube to the end portion of the jacket is shorter than the distance from the ferrule to the connection portion between the glass optical fibers. Reinforcement structure.

  According to the third aspect of the invention, the glass optical fiber and the reinforcing core are integrated with each other, and the ends of the heat-shrinkable tube are integrated. Since the distance from the part to the end of the jacket is short, a more compact connector can be obtained.

  According to the present invention, it is possible to provide a reinforcing sleeve or the like that is small in size and excellent in the workability of reinforcing the connecting portion.

FIG. 2 is an exploded perspective view showing a reinforcing sleeve 1. It is a figure which shows the reinforcement process of the connection part of the glass optical fibers using the reinforcement sleeve 1, (a) is a front view, (b) is the BB sectional drawing of (a). The figure which shows the reinforcement process of the connection part of glass optical fibers using the reinforcement sleeve. It is a figure which shows the reinforcement process of the connection part of the glass optical fibers using the reinforcement sleeve 1, (a), (b) is a front view, (c) is the EE sectional view taken on the line of (b). It is a figure which shows the reinforcement process of the connection part of the glass optical fibers using the reinforcement sleeve 1, (a) is a front view, (b) is the FF sectional view taken on the line of (a). The figure which shows other embodiment of a heat contraction tube. It is a figure which shows the reinforcement process of the connection part of the glass optical fibers using the conventional reinforcement sleeve 100, (a) is a front view, (b) is the HH sectional view taken on the line of (a). The figure which shows the reinforcement process of the connection part of the glass optical fibers using the conventional reinforcement sleeve 100. FIG. It is a figure which shows the reinforcement process of the connection part of the glass optical fibers using the conventional reinforcement sleeve 100, (a) is a front view, (b) is the JJ sectional view taken on the line of (a).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view showing the reinforcing sleeve 1. The reinforcing sleeve 1 includes a heat shrinkable tube 3, a heat melting member 5, a reinforcing core member 7, and the like. The heat shrinkable tube 3 is a cylindrical member. The heat-shrinkable tube 3 has a substantially circular cross section. The heat shrinkable tube 3 is made of, for example, a polyethylene resin.

  The heat melting member 5 is a cylindrical member. The hot melt member 5 has a substantially circular cross section. The heat melting member 5 is made of, for example, an ethylene vinyl acetate resin. The heat melting member 5 is desirably melted at a temperature lower than the heat shrink temperature of the heat shrinkable tube 3.

  The reinforcing core member 7 which is a strength member is a rod-shaped member. The reinforcing core member 7 is made of, for example, steel, carbon, glass, or the like. The reinforcing core member 7 is inserted into the heat melting member 5. That is, the reinforcing core member 7 is covered with the heat melting member 5.

  In the reinforcing sleeve 1, a reinforcing core member 7 covered with the heat melting member 5 can be inserted into and removed from the heat shrinkable tube 3 (in the direction of arrow A in the figure). The outer diameter of the heat melting member 5 is slightly smaller than the inner diameter of the heat shrinkable tube 3.

  Next, a method for reinforcing the connecting portion between the glass optical fibers using the reinforcing sleeve 1 will be described. FIGS. 2A and 2B are diagrams showing a reinforcing process of the connecting portion between the glass optical fibers using the reinforcing sleeve 1, FIG. 2A is a front view, and FIG. 2B is a BB line in FIG. It is sectional drawing. The optical cord 9 is provided with a tensile body and a jacket 11 (not shown) on the outer periphery of the optical fiber core wire 13. The optical fiber core 13 is a glass optical fiber 15a provided with a resin coating on the outer periphery.

  First, as shown in FIG. 2A, the outer cover 11 at the tip of the optical cord 9 is cut by a predetermined length. Further, the resin coating of the optical fiber core wire 13 is removed to expose the glass optical fiber 15a for a predetermined length. At this time, the exposed length of the optical fiber core wire 13 (resin coating portion) of the optical cord 9 may be sufficiently shorter than the reinforcing sleeve 1.

  In this state, the heat shrinkable tube 3 is inserted through the outer periphery of the outer jacket 11. As shown in FIG. 2B, in this state, the reinforcing core member 7 and the heat melting member 5 are extracted from the heat shrinkable tube 3. Therefore, the optical cord 9 having the jacket 11 is inserted into the heat shrinkable tube 3. Thus, the inner diameter of the heat shrinkable tube 3 is slightly larger than the outer diameter of the outer cover 11 so that the optical cord 9 can be inserted into the heat shrinkable tube 3.

  The tip of the glass optical fiber 15a is disposed to face the tip of the glass optical fiber 15b to be connected. The glass optical fiber 15 b is fixed to the ferrule 17. The connection target may be not only the glass optical fiber 15b fixed to the ferrule 17 as shown, but also an optical fiber fixed to another optical cord or the like. That is, it can also be used for connection between optical fibers fixed to the optical cord or connection between optical fibers fixed to the ferrule. In this state, the glass optical fibers 15a and 15b are fused and connected by the discharge of the electrode 19. Accordingly, the exposed length of the glass optical fibers 15a and 15b may be set to such an extent that a fusion splicing operation can be performed in a fusion machine or the like.

  As shown in FIG. 3A, after the glass optical fibers 15a and 15b are connected by the connection portion 21, as shown in FIG. 3B, the connection portion 21 and the glass optical fibers 15a and 15b are covered. The heat-shrinkable tube 3 is moved along the optical cord 9 (in the direction of arrow C in the figure). At this time, the heat shrinkable tube 3 is moved so as not to overlap the outer periphery of the outer cover 11. Accordingly, the glass optical fibers 15 a and 15 b and a part of the optical fiber core wire 13 are located inside the heat shrinkable tube 3.

  Next, as shown in FIG. 4A, the reinforcing core material 7 covered with the heat melting member 5 is inserted into the heat shrinkable tube 3 (in the direction of arrow D in the figure). FIG. 4B is a view showing a state in which the heat-melting member 5 and the reinforcing core member 7 are completely inserted into the heat-shrinkable tube 3, and FIG. 4C is a view taken along line EE in FIG. It is line sectional drawing.

  As shown in FIG. 4C, glass optical fibers 15 a and 15 b (optical fiber core wire 13) are inserted into the heat shrinkable tube 3. The glass optical fibers 15 a and 15 b (optical fiber core wire 13) are sufficiently small with respect to the outer diameter of the jacket 11. For this reason, a space for inserting the heat melting member 5 and the reinforcing core member 7 is formed. Therefore, the heat melting member 5 and the reinforcing core member 7 can be inserted into the heat shrinkable tube 3 together with the glass optical fibers 15 a and 15 b (optical fiber core wire 13).

  Here, the reinforcing core member 7 is covered with the heat melting member 5. Therefore, the glass optical fibers 15a and 15b (optical fiber core wire 13) do not directly contact the reinforcing core member 7. For this reason, the glass fiber 15a, 15b (optical fiber core wire 13) is not damaged by the reinforcing core material 7.

  The reinforcing sleeve 1 is heated from this state. Fig.5 (a) is a figure which shows the state which heated the reinforcement sleeve 1, FIG.5 (b) is a FF sectional view taken on the line of Fig.5 (a). When the heat-shrinkable tube 3 is heated, the heat-shrinkable tube 3 contracts due to the heating. Moreover, the hot-melt member 5 which melts below the heating temperature is melted by heating. Therefore, as shown in FIG. 5B, the heat shrinkable tube 3 and the heat melting member 5 are integrated. That is, the glass optical fibers 15a and 15b and the reinforcing core member 7 are integrated by the heat melting member 5 (heat shrinkable tube 3). As described above, the vicinity of the connecting portion between the glass optical fibers 15a and 15b can be reinforced.

  Normally, in order to fuse the glass optical fibers 15a and 15b, it is necessary to retract the heat-shrinkable tube 3 at least as long as the length from the ferrule 17 to the connecting portion 21. Therefore, in the conventional reinforcing sleeve 100 shown in FIGS. 7 to 9, the outer jacket 111 is removed by at least a length longer than that to form an exposed portion of the optical fiber core wire 113 (a retracting portion of the reinforcing sleeve 100). There is a need to.

  On the other hand, in the present invention, since the reinforcing sleeve 1 (heat-shrinkable tube 3) is retracted to the position of the jacket 11, the length of the exposed portion of the optical fiber core wire 13 can be shortened. For example, in FIG. 5A, the exposed length of the optical fiber core wire 13 (the length from the end of the reinforcing sleeve 1 to the end of the jacket 11) with respect to the length G from the ferrule 17 to the connecting portion 21. ) Can be made sufficiently small. Therefore, the length of the connection portion can be shortened.

  As described above, according to the present embodiment, the reinforcing core member 7 and the heat melting member 5 can be inserted into and removed from the heat shrinkable tube 3. For this reason, when the heat-shrinkable tube 3 is retracted from the connecting portion at the time of fusion splicing, the heat-melting member 5 and the reinforcing core member 7 can be extracted from the heat-shrinkable tube 3. Therefore, the heat-shrinkable tube 3 can be retracted to the outer periphery of the jacket 11. At this time, since the inner diameter of the heat-shrinkable tube 3 only needs to be slightly larger than the outer diameter of the jacket 11, it is not necessary to make the heat-shrinkable tube 3 excessively large.

  Further, since the heat-shrinkable tube 3 can be retracted to the outer periphery of the jacket 11, the removal length of the jacket 11 at the tip of the optical cord 9 can be shortened. Therefore, the connector etc. which connect the optical cord 9 can be shortened.

  Further, since the reinforcing core material 7 is covered with the heat melting member 5, when the reinforcing core material 7 is inserted into the heat shrinkable tube 3, the reinforcing core material 7 and the glass optical fibers 15a and 15b may be in direct contact with each other. Absent. For this reason, damage to the glass optical fibers 15a and 15b at the time of work can be prevented.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, it can also be set as the taper shape by which the internal diameter of one edge part was expanded like the heat contraction tube 3a shown to Fig.6 (a). By doing in this way, it becomes easy to insert the heat-melting member 5 and the reinforcement core material 7 in the heat-shrinkable tube 3 (arrow D direction in the figure).

  Moreover, you may form the groove | channel 23 along the longitudinal direction in the inner surface of the heat contraction tube 3b like the heat contraction tube 3b shown in FIG.6 (b). By doing in this way, the hot-melt member 5 and the reinforcing core material 7 can be easily inserted, and the inner diameter of the heat-shrinkable tube 3 can be reduced.

  Further, like the heat-shrinkable tube 3c shown in FIG. 6C, the cross-sectional shape of the heat-shrinkable tube 3c can be an elliptical shape instead of a substantially perfect circle shape. By doing in this way, the insertion operation | work of the hot-melt member 5 and the reinforcement core material 7 becomes easy.

DESCRIPTION OF SYMBOLS 1 ......... Reinforcement sleeve 3, 3a, 3b, 3c ......... Heat-shrinkable tube 5 ......... Heat-melting member 7 ......... Reinforcement core material 9 ......... Optical cord 11 ......... Wrap 13 ......... Light Fiber cores 15a, 15b ......... Glass optical fiber 17 ......... Ferrule 19 ......... Electrode 21 ......... Connector 23 ......... Groove 100 ......... Reinforcement sleeve 103 ......... Heat shrinkable tube 105 ......... Heat-melting member 107... Reinforcing core material 109... Optical cord 111 ....... Outer sheath 113... Optical fiber core wires 115 a, 115 b ... Glass optical fiber 117 ... Ferrule 119 ... Electrode 121 ……… Connection

Claims (6)

A reinforcing sleeve that reinforces the connection portion of the glass optical fiber,
A heat melting member;
A reinforcing core member inserted through the heat-melting member;
A heat shrinkable tube into which the reinforcing core member and the heat melting member can be inserted and removed;
Comprising
A reinforcing sleeve, wherein the reinforcing core material covered with the heat melting member can be inserted into the heat shrinkable tube in a state where a glass optical fiber is inserted into the heat shrinkable tube.   The reinforcing sleeve according to claim 1, wherein at least one end of the heat-shrinkable tube has a tapered shape with an enlarged inner diameter.   The reinforcing sleeve according to claim 1 or 2, wherein a groove is formed in an inner surface of the heat shrinkable tube in a longitudinal direction.   The reinforcing sleeve according to any one of claims 1 to 3, wherein a cross-sectional shape of the heat-shrinkable tube is an ellipse. A method for reinforcing an optical fiber connecting portion using the reinforcing sleeve according to any one of claims 1 to 4,
At the end of the optical cord, the predetermined length of the jacket is removed to expose the predetermined length of the glass optical fiber,
In a state where the heat-shrinkable tube is disposed on the outer periphery of the outer jacket of the optical cord, the glass optical fiber to be connected and the glass optical fiber of the optical cord are fused and connected,
The heat shrinkable tube is moved so as to cover the connection portion between the glass optical fibers, and the reinforcing core material covered with the heat melting member is inserted into the heat shrinkable tube,
Heating the heat-shrinkable tube and the heat-melting member, shrinking the heat-shrinkable tube and melting the heat-melting member, thereby integrating the reinforcing core member and the connection portion of the glass optical fiber; A method for reinforcing an optical fiber connecting portion. A reinforcing structure of an optical fiber connecting portion using the reinforcing sleeve according to any one of claims 1 to 4,
At the end of the optical cord, the jacket of a predetermined length is removed, and a glass optical fiber of a predetermined length is exposed,
The glass optical fiber fixed to the ferrule and the glass optical fiber of the optical cord are fusion spliced,
The connection portion between the glass optical fibers is integrated with the reinforcing core member by the heat melting member,
The reinforcing structure of an optical fiber connection portion, wherein a distance from an end portion of the heat shrinkable tube to an end portion of the jacket is shorter than a distance from the ferrule to a connection portion between the glass optical fibers.

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