JP2011248221A - Optical cable and optical active cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long optical cable which uses an optical loose cable and can prevent an optical fiber from buckling even when the optical cable is wound.SOLUTION: The optical cable comprises an optical loose cable 2 storing multiple optical fibers 4 in a sheath 5, and a clamp base 3. The clamp base 3 comprises: a sheath fixing part 6, provided at an end of the optical loose cable 2, to which the sheath 5 is fixed; an engaging part 7 to be engaged with a case of an optical device to be connected; and an insertion hole 8 to which the multiple optical fibers 4 are inserted, for guiding the multiple optical fibers 4 to the case. The insertion hole 8 is filled with an adhesive, the filled adhesive is solidified to form an adhesion part 19, and the multiple optical fibers 4 inserted to the insertion hole 8 are fixedly bonded to the clamp base 3.

Description

  The present invention relates to an optical cable and an optical active cable.

  For communication between supercomputers and high-end servers, an optical active cable in which an optical transceiver having an optical-electrical conversion function (optical transceiver) is provided at the end of an optical cable has been used. Optical active cables are smaller and lighter than conventional metal cables, and are suitable for high-speed and long-distance transmission.

  By the way, in the optical active cable for long-distance transmission, since the optical cable is long, the optical cable is often wound and handled. However, when an optical cable is used, for example, a general optical cable in which a sheath is provided on the outer periphery of a plurality of optical fibers (that the plurality of optical fibers cannot move freely in the sheath), when the optical cable is wound, the radial direction Some optical fibers are buckled due to the path difference (so-called inner / outer ring difference) between the optical fiber located on the inner side and the optical fiber located on the outer side in the radial direction, or the shrinkage of the sheath due to temperature change. Problems arise.

  In order to avoid such a problem, an optical loose cable has been used as an optical cable in an optical active cable for long-distance transmission.

  As shown in FIG. 9, the optical loose cable 2 is one in which a plurality of optical fibers 4 are loosely accommodated in a sheath 5 with a gap. In the optical loose cable 2, the plurality of optical fibers 4 can move to some extent within the sheath 5, so that buckling of the optical fiber due to winding can be suppressed.

  As prior art document information related to the invention of this application, there are Patent Documents 1 and 2.

US Patent Application Publication No. 2003/0063869 Japanese Patent No. 3967228

  However, when the optical loose cable 2 is wound, there is a problem that the protruding amount of the optical fiber 4 (the exposed length of the optical fiber 4 exposed from the end of the optical loose cable 2) varies. Specifically, for example, as shown in FIGS. 10A and 10B, when the 10 m optical loose cable 2 is wound at φ90 mm in an environment of 85 ° C., the protruding amount of the optical fiber 4 is 2 mm. It will fluctuate to some extent.

  When the optical loose cable 2 is used as an optical active cable, the optical fiber 4 is optically connected to the photoelectric conversion unit of the optical transceiver at the end of the optical fiber 4 exposed from the end of the optical loose cable 2. A multi-fiber optical connector such as a MT (Mechanically Transferable) ferrule is collectively provided. Therefore, if the protruding amount of the optical fiber 4 fluctuates, a part of the optical fiber 4 buckles in the vicinity of the optical connector such as the MT ferrule, the optical characteristics deteriorate, or the unit breaks (breaks) per unit time. ) There is a risk that the probability will increase and the product life will be shortened.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and an optical cable capable of preventing buckling of an optical fiber even when the optical cable is wound in a long optical cable using an optical loose cable. And providing an optical active cable.

  The present invention was devised to achieve the above object, and is provided with an optical loose cable in which a plurality of optical fibers are loosely accommodated in a sheath, and provided at an end of the optical loose cable, and the sheath is fixed. A sheath fixing portion that engages with a housing of the optical device to be connected, and an insertion for guiding the plurality of optical fibers into the housing. A plurality of the light beams inserted into the insertion holes, filling the insertion holes with an adhesive and solidifying the filled adhesive to form an adhesive portion. An optical cable in which a fiber is bonded and fixed to the clamp base.

  The bonding portion includes a first bonding portion formed in the insertion hole on the optical device side, and a second bonding portion formed in the insertion hole on the optical loose cable side than the first bonding portion. The second adhesive portion may be formed using an adhesive having a higher viscosity than the adhesive used for the first adhesive portion and low elasticity after solidification.

  The end of the insertion hole on the optical device side may be formed in a tapered shape whose diameter gradually increases toward the optical device side.

  A branching projection for dividing the plurality of optical fibers into two groups may be provided in the insertion hole of the clamp base.

  Moreover, this invention is an optical active cable which provided the optical transmitter / receiver as the said optical device in the edge part of the said optical cable.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where an optical cable is wound in the long optical cable using an optical loose cable, the optical cable and optical active cable which can prevent buckling of an optical fiber can be provided.

It is a figure which shows the optical cable which concerns on one embodiment of this invention, (a) is a perspective view, (b) is the AA 'line sectional perspective view, (c) is an AA' line sectional view. . (A) is sectional drawing when the optical cable of FIG. 1 is attached to an optical device, FIG.2 (b) is the principal part enlarged view. FIG. 2 is a diagram for explaining that a tensile strength line is caulked and fixed by a tensile strength caulking ring in the optical cable of FIG. 1. It is a perspective view of the optical active cable using the optical cable of FIG. FIG. 5 is a top view of the optical active cable of FIG. 4 when the upper housing is removed. FIG. 5A is a perspective view when the upper housing is removed from the optical active cable of FIG. 4, and FIG. 5B is a perspective view when the boot is further removed. It is a figure which shows the optical cable which concerns on one embodiment of this invention, (a) is a perspective view, (b) is the BB 'sectional view perspective view, (c) is a BB' sectional view. . It is a figure which shows the optical cable which concerns on one embodiment of this invention, (a) is sectional drawing, (b) is a perspective view. It is a cross-sectional view of an optical loose cable. (A), (b) is a figure explaining the protrusion amount of an optical fiber changing when a long optical loose cable is wound.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  1A and 1B are diagrams showing an optical cable according to the present embodiment, wherein FIG. 1A is a perspective view, FIG. 1B is a cross-sectional perspective view taken along line AA ′, and FIG. 1C is a cross-sectional view taken along line AA ′. is there. FIG. 2A is a cross-sectional view when the optical cable according to the present embodiment is attached to the optical device, and FIG. 2B is an enlarged view of a main part thereof. For simplification of the drawing, the boot 18 is omitted in FIGS. 1A to 1C, and the optical fiber 4 and the bonding portion 19 are omitted in FIGS. 2A and 2B. Yes.

  As shown in FIGS. 1A to 1C and FIGS. 2A and 2B, an optical cable 1 includes an optical loose cable 2 and a clamp base 3 provided at an end of the optical loose cable 2. It has.

  The optical loose cable 2 is one in which a plurality of optical fibers 4 are loosely accommodated in a sheath 5 with a gap. In the present embodiment, a case will be described in which a total of 24 optical fibers 4 of 12 transmission-side optical fibers 4a and 12 reception-side optical fibers 4b are used. In the sheath 5, a tensile strength line (tensile strength fiber, see FIG. 3) 12 is accommodated together with the optical fiber 4.

  The clamp base 3 is made of a hard material such as metal. In the present embodiment, the case where a clamp base 3 made of metal is used will be described.

  The clamp base 3 includes a sheath fixing portion 6 to which an end portion of the sheath 5 of the optical loose cable 2 is fixed, an engaging portion 7 to be engaged with the housing 10 of the optical device 9 to be connected, and a plurality of light beams. An insertion hole 8 is provided for inserting the fiber 4 and guiding the plurality of optical fibers 4 into the housing 10.

  The sheath fixing part 6 is formed in a hollow cylindrical shape. A tensile strength caulking ring 11 for caulking and fixing the tensile strength wire is provided on the outer periphery of the sheath fixing portion 6. As shown in FIG. 3, the tensile strength wire 12 is caulked and fixed to the outer periphery of the sheath fixing portion 6 of the clamp base 3 by the tensile strength caulking ring 11.

  A sheath caulking ring 13 for caulking and fixing the sheath 5 is provided on the outer periphery of the tensile strength caulking ring 11. A slit 5a having a predetermined length is formed at the end of the sheath 5 along the longitudinal direction. The end of the sheath 5 is disposed on the outer periphery of the tensile strength caulking ring 11 while expanding the slit 5a. The sheath 5 is fixed to the clamp base 3 (sheath fixing portion 6) by caulking and fixing the end portion thereof with the sheath caulking ring 13.

  The engaging portion 7 is formed in a hollow cylindrical shape continuous with the sheath fixing portion 6, and two flange portions 14 and 15 are formed on the outer periphery thereof. The 1st flange part 14 is formed in the front-end | tip part (left side edge part in FIG.1 (c)) of the engaging part 7, and is formed in a substantially rectangular shape by front view. The second flange portion 15 is formed at a predetermined interval behind the first flange portion 14 (on the right side in FIG. 1C) and is formed in a circular shape when viewed from the front. By engaging the cylindrical portion 16 between the first flange portion 14 and the second flange portion 15 with the engagement groove 17 formed in the housing 10 of the optical device 9, the clamp base 3 ( The joint portion 7) is fixed to the housing 10 of the optical device 9.

  The insertion hole 8 is formed so as to penetrate the sheath fixing portion 6 and the engaging portion 7. An optical fiber 4 (transmission-side optical fiber 4 a and reception-side optical fiber 4 b) extending from the end of the optical loose cable 2 is inserted into the insertion hole 8 so that the optical fiber 4 is guided into the housing 10. To be.

  At the end of the insertion hole 8 on the optical device 9 side (the left end in FIG. 1C), a tapered portion 8a formed in a tapered shape whose diameter gradually increases toward the optical device 9 is formed. Is done. This is a device for preventing the optical fiber 4 extending from the insertion hole 8 from being damaged by interference with the edge of the insertion hole 8.

  In the optical cable 1, a boot 18 is provided so as to cover the end of the optical loose cable 2 and a part of the clamp base 3 (the sheath fixing portion 6 and the second flange portion 15 of the engaging portion 7). The boot 18 is made of a resin having flexibility, elasticity, and flexibility, such as rubber and elastomer. A flange portion 18 a is formed at the tip of the boot 18, and the boot 18 is fixed to the housing 10 by engaging the flange portion 18 a with a boot engaging groove 21 formed in the housing 10. . By fixing the clamp base 3 and the boot 18 to the housing 10, as a result, the relationship between the clamp base 3 and the boot 18 is also fixed.

  Now, in the optical cable 1 according to the present embodiment, the insertion hole 8 of the clamp base 3 is filled with an adhesive, and the filled adhesive is solidified to form an adhesive portion 19, which is inserted into the insertion hole 8. A plurality of optical fibers 4 are bonded and fixed to the clamp base 3. As the adhesive used for the bonding portion 19, for example, a thermosetting resin, a room temperature curable resin, an ultraviolet curable resin, or the like may be used. In addition, as an adhesive used for the bonding portion 19, in order to suppress the stress from being concentrated on the optical fiber 4 (particularly, the optical fiber 4 on the optical device 9 side) in the vicinity of the bonding portion 19, It is desirable to use one having appropriate elasticity.

  The clamp base 3 is formed with an injection port 20 for injecting an adhesive. The injection port 20 is formed at the tip of the clamp base 3 (the end on the left front side in FIG. 1A). In the present embodiment, the notch-shaped injection port 20 is formed from the first flange portion 14 of the engaging portion 7 to the cylindrical portion 16. In addition, you may make it inject | pour an adhesive directly into the insertion hole 8 using a syringe etc., without forming the injection hole 20. FIG.

  The adhesion portion 19 is formed over the entire length of the insertion hole 8 excluding the taper portion 8a. Further, the adhesive portion 19 is not formed on the optical loose cable 2 behind the clamp base 3. This is because, since the optical loose cable 2 has flexibility, when the adhesive portion 19 is formed on the optical loose cable 2 behind the clamp base 3, the optical loose cable 2 is bent in the vicinity of the adhesive portion 19 when the optical loose cable 2 is bent. This is because stress concentrates on the optical fiber 4 and the optical fiber 4 may be broken (broken). As an adhesive used for the bonding portion 19, an adhesive having an appropriate viscosity may be used so that the adhesive does not flow out to the optical loose cable 2 behind the clamp base 3 during filling.

  Next, an optical active cable using the optical cable 1 will be described with reference to FIGS.

  4 is a perspective view of the optical active cable according to the present embodiment, FIG. 5 is a top view when the upper housing is removed, and FIG. 6A is a diagram when the upper housing is removed. FIG. 6B is a perspective view when the upper housing and the boot are removed.

  As shown in FIGS. 4 to 6, the optical active cable 41 is provided with an optical transceiver 42 as an optical device 9 at the end of the optical cable 1.

  The optical transceiver 42 converts the electrical signal into an optical signal and outputs it to the transmission side optical fiber 4a, and converts the optical signal received from the reception side optical fiber 4b into an electrical signal and outputs it. A receiving-side photoelectric conversion unit 44.

  The transmission-side photoelectric conversion unit 43 includes a light-emitting element array (not shown) such as a VCSEL (Vertical Cavity Surface Emitting Laser) array, a driver IC (not shown) that drives the light-emitting element array, the light-emitting element array, and the transmission side A mirror member (not shown) for optically coupling the optical fiber 4a. A 12-core MT ferrule 45 as an optical connector is provided at the end of the transmission side optical fiber 4a, and the light emitting element array and the transmission side optical fiber 4a are optically connected via the MT ferrule 45 and a mirror member. Connected.

  The receiving-side photoelectric conversion unit 44 includes a light receiving element array (not shown) such as a PD (Photo Diode) array, an amplifier IC (not shown) that amplifies an electric signal from the light receiving element array, and the light receiving element array and the receiving side. A mirror member (not shown) for optically coupling the side optical fiber 4b. A 12-fiber MT ferrule 46 as an optical connector is provided at the end of the reception side optical fiber 4b, and the light receiving element array and the reception side optical fiber 4b are optically connected via the MT ferrule 46 and a mirror member. Connected.

  The transmission side photoelectric conversion unit 43 and the reception side photoelectric conversion unit 44 are mounted on a substrate 47. A connection terminal 48 is formed at an end of the substrate 47 (the left end in FIG. 5), and a card edge connector 49 is formed.

  In the optical transceiver 42, a housing 50 is provided so as to cover the substrate 47. The housing 50 has a two-divided configuration of an upper housing 50a and a lower housing 50b. An engagement groove 17 for engaging the engagement portion 7 of the clamp base 3 is formed at the rear end portion (the right end portion in FIG. 5) of the lower housing 50b. With the substrate 47 placed on the lower housing 50 b and the engaging portion 7 of the clamp base 3 engaged with the engaging groove 17, the upper housing 50 a is disposed above the substrate 47, and the upper housing The optical transceiver 42 and the optical cable 1 are fixed by fixing and integrating the 50a and the lower casing 50b by screwing or the like.

  The upper casing 50a is provided with a latch mechanism 51 for detachably holding the optical transceiver 42 in a cage (not shown) provided in the information system device to be connected. The latch mechanism 51 is configured such that a latch release member 53 is slidably received in a slide groove 52 formed on the upper surface of the upper housing 50a, and a cover 54 is provided so as to cover the upper part. A locking claw 55 that engages with an engagement hole formed on the upper surface of the cage from above is formed at the front end of the latch release member 53, and the rear end protrudes rearward of the upper housing 50a. A lever portion 56 is formed. In the latch mechanism 51, by pulling the lever portion 56 rearward, the latching claw 55 is pulled upward, and the optical transceiver 42 is detached from the cage.

  The operation of the present embodiment will be described.

  In the optical cable 1 according to the present embodiment, the insertion hole 8 of the clamp base 3 is filled with an adhesive, and the filled adhesive is solidified to form an adhesive portion 19, and a plurality of pieces inserted through the insertion hole 8. The optical fiber 4 is bonded and fixed to the clamp base 3.

  Thus, even when the optical loose cable 2 is made long and the optical loose cable 2 is wound, the protruding amount of the optical fiber 4 (the exposed length of the optical fiber 4 exposed from the end of the optical loose cable 2). ) Will not fluctuate. Therefore, even when multi-fiber optical connectors such as the MT ferrules 45 and 46 are collectively provided at the end of the optical fiber 4, some of the optical fibers 4 are not buckled in the vicinity of the optical connector, There is no possibility that the optical characteristics will deteriorate or the probability of breakage (breakage) per unit time will increase and the product life will be shortened. In addition, the fluctuation | variation of the protrusion amount of the optical fiber 4 at the time of winding the optical loose cable 2 is absorbed by the optical loose cable 2 behind the clamp base 3.

  Moreover, in the optical cable 1, since the edge part by the side of the optical device 9 of the insertion hole 8 is formed in the taper shape which a diameter becomes large gradually toward the optical device 9 side, the optical fiber 4 extended from the insertion hole 8 is formed. It can suppress that it interferes with the edge of the insertion hole 8, and damages.

  Next, another embodiment of the present invention will be described.

  The optical cable 71 shown in FIGS. 7A to 7C has basically the same configuration as the optical cable 1 in FIG. 1, and the bonding portion 19 is an insertion hole on the optical device 9 side (left side in FIG. 7C). A first adhesive portion 19a formed on the optical loose cable 2 side (right side in FIG. 7C) from the first adhesive portion 19a and a second adhesive portion 19b formed on the insertion hole 8 on the optical loose cable 2 side. Is different. The 2nd adhesion part 19b is formed using the 2nd adhesive whose viscosity is higher than the 1st adhesive used for the 1st adhesion part 19a, and low elasticity after solidification. 7A to 7C, the boot 18 is omitted for simplification of the drawing.

  When manufacturing the optical cable 71, first, the second adhesive is injected into the insertion hole 8 from the cut 5a of the sheath 5, and this is solidified to form the second adhesive portion 19b. Since the second adhesive has a high viscosity, it does not flow out to the optical loose cable 2 behind the clamp base 3 due to a capillary phenomenon or the like. Moreover, since the elasticity of the 2nd adhesion part 19b becomes low (that is, it becomes hard) by using the thing with low elasticity after solidification as a 2nd adhesive agent, the optical fiber 4 can be firmly bonded and fixed to the clamp base 3. It becomes possible. Note that the optical fiber 4 behind the second adhesive portion 19b is protected by the sheath 5 and the boot 18 and is not likely to be bent at a steep angle, so even if the elasticity of the second adhesive portion 19b is lowered, There is no possibility that the optical fiber 4 will buckle in the vicinity of the second adhesive portion 19b.

  Then, the 1st adhesive agent is inject | poured from the injection hole 20 formed in the engaging part 7 of the clamp base 3, and this is solidified, and the 1st adhesion part 19a is formed. When the first adhesive is injected, since the second adhesive portion 19b is already formed, the second adhesive portion 19b serves as a weir, and the first adhesive is an optical loose cable behind the clamp base 3. 2 will not flow out. Moreover, since the elasticity of the 1st adhesion part 19a becomes high (that is, it becomes soft) by using a thing with high elasticity after solidification as a 1st adhesive agent, the optical fiber 4 extended from the 1st adhesion part 19a is made to be somewhat steep. Even if the optical fiber 4 is bent at an angle, the optical fiber 4 can be prevented from buckling in the vicinity of the first bonding portion 19a.

  In addition, although the case where the adhesion part 19 was comprised in two steps, the 1st adhesion part 19a and the 2nd adhesion part 19b was demonstrated here, not only this but the adhesion part 19 is good also as a structure of two or more steps. In this case, the bonding portion 19 may be configured so that the elasticity gradually increases from the optical loose cable 2 side to the optical device 9 side.

  The optical cable 81 shown in FIGS. 8A and 8B is used to divide a plurality of optical fibers 4 into two groups (transmission side optical fiber 4a and reception side optical fiber 4b) in the insertion hole 8 of the clamp base 3. The branching projection 82 is provided. For simplification of the drawing, the boot 18 is omitted in FIG. 8A, and the boot 18, the optical fiber 4, and the bonding portion 19 are omitted in FIG. 8B.

  The branching protrusion 82 is formed in the vicinity of the exit of the insertion hole 8 (in the vicinity of the end on the optical device 9 side), and here, is formed in the insertion hole 8 immediately behind the taper portion 8a. The branching protrusion 82 is formed in a substantially triangular shape (isosceles triangular shape) in a top view, and is formed so that the apex thereof faces the optical loose cable 2 side.

  Here, the branching protrusion 82 is formed so as to protrude to the vicinity of the center of the insertion hole 8. However, the present invention is not limited to this, and the branching protrusion 82 is extended to the inner wall of the opposing insertion hole 8. The insertion hole 8 may be divided into two by 82.

  By forming the branching protrusion 82, the optical fiber 4 can be easily divided into the transmission side optical fiber 4a and the reception side optical fiber 4b.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Optical cable 2 Optical loose cable 3 Clamp base 4 Optical fiber 5 Sheath 6 Sheath fixing | fixed part 7 Engagement part 8 Insertion hole 19 Bonding part

Claims (5)

An optical loose cable that loosely accommodates a plurality of optical fibers in a sheath;
A sheath fixing portion provided at an end of the optical loose cable, to which the sheath is fixed, an engagement portion to be engaged with a housing of an optical device to be connected, and the plurality of optical fibers are inserted; A clamp base having an insertion hole for guiding the plurality of optical fibers into the housing, and
Filling the insertion hole with an adhesive, solidifying the filled adhesive to form an adhesive portion, and bonding and fixing the plurality of optical fibers inserted into the insertion hole to the clamp base Features an optical cable. The bonding portion includes a first bonding portion formed in the insertion hole on the optical device side, and a second bonding portion formed in the insertion hole on the optical loose cable side than the first bonding portion. ,
The optical cable according to claim 1, wherein the second adhesive portion is formed using an adhesive having a viscosity higher than that of the adhesive used for the first adhesive portion and low elasticity after solidification.   The optical cable according to claim 1, wherein an end of the insertion hole on the optical device side is formed in a tapered shape having a diameter that gradually increases toward the optical device.   The optical cable according to claim 1, wherein a branching projection for dividing the plurality of optical fibers into two groups is provided in the insertion hole of the clamp base.   An optical active cable comprising an optical transceiver as the optical device at an end of the optical cable according to claim 1.

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