JP2013137348A - Terminal anchoring structure of optical cable and optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal anchoring structure of an optical cable, which allows an entire circumference of a sheath to be uniformly caulked without damaging the sheath, and an optical module.SOLUTION: In the terminal anchoring structure of an optical cable, an optical cable terminal fixing member 30 includes: a cylindrical body part 31 which includes a sheath fixing part 33 having an outer peripheral surface smoothly processed so as to fix thereto a sheath 18 and a cable insertion path 35 to which a coated optical fiber 14 is to be inserted; and a crimping part 32 which is to be caulked to the outer peripheral surface of the sheath fixing part 33 and has an inner peripheral surface smoothly processed. The coated optical fiber 14 is inserted through the cable insertion path 35, the sheath 18 is put over the sheath fixing part 33, and the crimping part 32 is caulked from the outer periphery of the sheath fixing part 33 throughout the circumference of the outer peripheral surface of the sheath fixing part 33.

Description

  The present invention relates to an optical cable terminal fixing structure and an optical module.

  A conventional optical module includes a circuit board on which a photoelectric conversion unit connected to an optical fiber of an optical cable is mounted, and a metal housing that houses the circuit board. In this optical module, an input / output electric signal is converted into an optical signal by a photoelectric conversion unit, and signal transmission using the optical signal is performed.

  In the optical cable used in this optical module, tensile strength fibers for increasing the tensile strength of the optical cable are vertically attached to the outside of the single-core or multi-core optical fiber, and the outer side is covered with a jacket (for example, patent Reference 1).

  In the terminal fixing structure of the optical cable, the outer cover of the end portion of the optical cable is removed, and the tensile strength fiber is exposed. The exposed tensile strength fiber is provided in the housing of the optical connector, and is crimped and fixed to a fixing portion having a thread groove by a sleeve member. The sleeve member has a non-cylindrical shape, and is provided with a plurality of engagement pieces that are engaged with each other during pressure bonding.

JP-A-11-231171

However, in the terminal fixing structure of the optical cable, when the tensile strength fiber is crimped and fixed to the fixing portion, the outer cover may be damaged by the screw groove of the fixing portion.
In addition, since the sleeve member for fixing the jacket of the optical cable is a non-cylindrical shape, it is easily crushed into an ellipse shape when caulked, and a gap is formed between the sleeve member and the jacket, so that the entire circumference of the jacket is uniform. There is a possibility that the fixing force may be insufficient.

  An object of the present invention is to provide an optical cable terminal fixing structure and an optical module capable of uniformly caulking the entire circumference of the jacket without damaging the jacket.

An optical cable terminal fixing structure according to the present invention capable of solving the above-mentioned problems is an optical cable terminal fixing structure having a jacket on the outside of an optical fiber,
A cylindrical main body having a jacket fixing portion whose outer peripheral surface is processed smoothly so as to fix the jacket, and a cable insertion path through which the optical fiber is inserted inside the jacket fixing portion;
An optical cable terminal fixture provided with a crimped portion that is crimped to the outer peripheral surface of the outer jacket fixing portion and whose inner peripheral surface is processed smoothly;
The optical fiber is inserted through the cable insertion path, the outer cover is covered by the outer cover fixing part, and the crimping part is crimped from the outer periphery over the entire outer periphery of the outer cover fixing part. It is characterized by being.

  Further, in the optical cable terminal fixing structure according to the present invention, the crimping portion has a crimping piece on both ends thereof and a notch portion adjacent to the crimping piece, and the notch portion on one end side has the notch portion on the other end side. It is preferable that the crimping piece is crimped.

  Moreover, it is preferable that the optical cable according to the present invention has a metal layer outside the optical fiber and inside the jacket, and the metal layer covers the jacket fixing portion.

An optical module according to the present invention capable of solving the above problems is made of a metal that houses an optical cable having a jacket on the outside of an optical fiber and a circuit board on which a photoelectric conversion unit to which the optical fiber is connected is mounted. A housing,
An optical module in which a terminal portion of the optical cable is fixed to one end of the housing,
A cylindrical main body having a jacket fixing portion whose outer peripheral surface is processed smoothly so as to fix the jacket, and a cable insertion path through which the optical fiber is inserted inside the jacket fixing portion;
A crimping part that is crimped to the outer peripheral surface of the outer jacket fixing part and whose inner peripheral surface is processed smoothly, and an optical cable terminal fixture,
The optical fiber is inserted through the cable insertion path, the outer cover is covered by the outer cover fixing part, and the crimping part is crimped from the outer periphery over the entire outer periphery of the outer cover fixing part. It is characterized by being.

  In the optical module according to the present invention, the optical cable has a metal layer on the outer side of the optical fiber and on the inner side of the jacket, and the metal layer is placed on the jacket fixing portion, and the outer periphery of the jacket It is preferable that the crimping portion is crimped over the entire circumference of the outer peripheral surface of the jacket fixing portion. Furthermore, it is preferable that the metal layer is soldered to the housing.

  According to the optical cable terminal fixing structure and the optical module according to the present invention, the outer cover is placed on the outer cover fixing portion, and the crimping portion is crimped from the outer periphery of the outer peripheral surface of the outer cover fixing portion. The entire circumference of the jacket can be uniformly crimped and fixed without damaging the jacket.

1 is a perspective view showing an embodiment of an optical module according to the present invention. It is sectional drawing of the optical cable of FIG. It is a perspective view which shows the housing | casing inside the optical module of FIG. 1 is a perspective view showing an embodiment of an optical cable terminal fixture according to the present invention. It is a perspective view which shows the attachment state of the optical cable terminal fixture of FIG. It is a perspective view which shows the crimping state of the optical cable terminal fixture of FIG. It is sectional drawing in the AA of FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of an optical cable terminal fixing structure and an optical module according to the invention will be described with reference to the drawings.

  An optical module is used for transmission of signals (data) in optical communication technology, etc., and is electrically connected to an electronic device such as a connected personal computer, and converts an input / output electric signal into an optical signal. An optical signal is transmitted.

  As shown in FIG. 1, in the optical module 10 of this embodiment, a connector module is connected to an end portion of an optical cable 11. This connector module includes an electrical connector 12 provided on the distal end side, and an exterior housing 13 that covers a metal housing 20 (see FIG. 3) that houses a circuit board 22. A connection portion between the optical cable 11 and the housing 20 is covered with a boot 19.

  As shown in FIG. 2, the optical cable 11 has an optical fiber ribbon 14a in the center as seen in its cross section. The optical fiber ribbon 14a is obtained by integrating a plurality (four in this example) of optical fibers 14 in parallel on a plane and integrating them in a tape shape with a coating resin. The optical fiber ribbon 14 a is accommodated inside the inner tube 15. An intervening layer 16 is provided around the inner tube 15 along a bundle of tensile strength fibers. A metal layer 17 composed of a plurality of metal strands is provided on the outer periphery of the intervening layer 16. A jacket 18 made of an insulating resin is provided on the outer periphery of the metal layer 17.

  As the optical fiber core 14, an optical fiber (AGF: All Glass Fiber) whose core and clad are quartz glass, an optical fiber (HPCF: Hard Plastic Clad Fiber) whose clad is made of hard plastic, and the like can be used. When a thin HPCF having a glass core diameter of 80 μm is used, it is difficult to break even if the optical fiber 14 is bent to a small diameter. The plurality of optical fiber core wires 14 can be accommodated in the inner tube 15 as a single core without being taped. However, when the optical fiber core wires 14 are taped, the single optical fiber core wires 14 cross each other and the lateral pressure is increased. The occurrence of microbend loss due to this can be prevented. A plurality of optical fiber ribbons 14a may be provided.

  The inner tube 15 is made of an insulating resin such as PVC (Polyvinylchloride) which is a non-halogen flame retardant resin. For example, the inner tube 15 has an outer diameter of 2.0 mm and a thickness of 0.55 mm. The intervening layer 16 is, for example, an ultrafine-diameter aramid fiber, and is built in the optical cable 11 in a bundled state. The intervening layer 16 has a tensile strength function in the optical cable 11. Hereinafter, the intervening layer 16 is referred to as a tensile strength fiber.

  The metal layer 17 is formed by braiding a plurality of tin-plated conductive wires, for example, and has a function as a heat dissipation layer. The braid density of the metal layer 17 is 70% or more, and the knitting angle is 45 ° to 60 °. The outer diameter of the metal wire constituting the metal layer 17 is about 0.05 mm. The thermal conductivity of the metal layer 17 is 400 W / m · K, for example. The metal layer 17 is preferably arranged at a high density in order to ensure good heat conduction. For example, the metal layer 17 is preferably composed of a rectangular tin-plated lead wire. The jacket 18 is made of an insulating resin such as polyolefin. The jacket 18 has, for example, an outer diameter of 4.2 mm and a thickness of 0.5 mm. The optical cable 11 having such a configuration is excellent in the lateral pressure characteristics of the optical fiber core wire 14, the flexibility as the cable, and is excellent in heat dissipation.

  As shown in FIG. 3, the housing 20 is a cylindrical housing member having a substantially rectangular cross section, and houses a circuit board 22 on which a photoelectric conversion unit 21 to which the optical fiber core wire 14 is connected is mounted. The storage space is defined. In addition, the housing 20 is provided with an electrical connector 12 at the front end, and an optical cable terminal fixture 30 that fixes the optical cable 11 is connected to the rear end. The housing 20 is made of a metal material having high thermal conductivity (preferably 100 W / m · K or more) such as steel (Fe-based), tin (tin-plated copper), stainless steel, copper, brass, and aluminum. Yes.

  As shown in FIG. 4, the optical cable terminal fixture 30 of the present embodiment has a two-part configuration of a main body portion 31 and a crimping portion 32. The main body 31 includes a jacket fixing portion 33 that fixes the jacket 18, a cable insertion passage 35 through which the optical fiber core wire 14 is inserted, and a flat plate-like base portion 34 that is disposed at the front end of the main body 31. , Is composed of. Since the outer peripheral surface of the outer cover fixing portion 33 is smoothed by surface processing, it can be smoothly performed without damaging the metal layer 17 and the outer cover 18 by caulking. On both sides of the cable insertion path 35 of the base portion 34, there are concave portions 36 for drawing the tensile strength fibers 16 of the optical cables 11 bundled in a plurality to the rear side of the jacket fixing portion 33.

  The crimping part 32 is a U-shaped crimping tool that is crimped to the outer peripheral surface of the jacket fixing part 33, and has a crimping piece 38 at both ends and a notch 39 adjacent to the crimping piece 38. . In the crimping portion 32, the crimping piece 38 on the other end side is crimped on the cutout portion 39 on the one end side when crimping to the jacket fixing portion 33. The inner peripheral surface 37 of the crimping part 32 is smoothed by surface processing. As described above, the inner peripheral surface 37 of the crimping portion 32 and the outer peripheral surface of the outer cover fixing portion 33 are smoothly processed, so that the caulking operation can be smoothly performed without damaging the outer cover 18.

Next, an example of a procedure for attaching the optical cable 11 to the optical cable terminal fixture 30 will be described.
As shown in FIG. 5, the metal layer 17 exposed by peeling off the outer cover 18 of the optical cable 11 is folded back to the outer peripheral side of the outer cover 18. Next, the optical fiber core wire 14, the inner tube 15, and the tensile strength wire 16 of the optical cable 11 are inserted into the cable insertion passage 35 of the main body portion 31, and the metal layer 17 and the jacket 18 are disposed on the outer periphery of the jacket fixing portion 33. It is put on.

  Next, the tensile strength wire 16 inserted through the cable insertion passage 35 is drawn from the surface side of the base portion 34 to the outer jacket fixing portion 33 side through the recess 36. The crimping portion 32 is moved to the metal layer 17 that is folded back on the outer peripheral side of the jacket 18, and the drawn tensile strength line 16 is pushed into the inner peripheral surface 37 side of the crimping portion 32.

  Next, as shown in FIG. 6, the crimping portion 32 is crimped over the entire circumference of the outer peripheral surface of the metal layer 17 by a dedicated crimping jig. At this time, the crimping piece 38 on the other end side is crimped on the notch 39 on the one end side, so that the entire circumference of the jacket 18 can be crimped uniformly with a simple structure. As a result, as shown in FIG. 7, the optical cable 11 is held and fixed to the optical cable terminal fixture 30, and the jacket 18, the metal layer 17, and the tensile wire 16 are interposed between the jacket fixing portion 33 and the crimping portion 32. It is pinched.

  Finally, the optical cable terminal fixture 30 is coupled to the rear end portion of the housing 20 so that the housing 20 and the optical cable terminal fixture 30 are physically and thermally connected. That is, the housing 20 and the metal layer 17 of the optical cable 11 are thermally connected.

  Although an example in which the end portion of the metal layer 17 of the optical cable 11 is folded back to the outer peripheral side of the jacket 18 has been described, it may be crimped or soldered to the housing 20 without being folded. Further, the metal layer 17 can be joined to the base 34 of the main body 31 by soldering. Thereby, the optical cable terminal fixture 30 and the metal layer 17 are thermally connected, and the heat generated in the housing 20 can be dissipated from the optical cable terminal fixture 30.

  As described above, the end fixing structure of the optical cable according to the present embodiment has a cylindrical shape including the outer cover fixing portion 33 where the optical cable end fixing tool 30 fixes the outer cover 18 and the cable insertion path 35 through which the optical fiber core wire 14 is inserted. Main body portion 31 and a crimping portion 32 that is crimped to the outer peripheral surface of the jacket fixing portion 33. Then, the optical fiber core wire 14 is inserted into the cable insertion path 35, the jacket 18 is covered with the jacket fixing portion 33, and the crimping portion 32 extends from the outer periphery of the outer peripheral surface of the jacket fixing portion 33. It is crimped.

  According to the terminal fixing structure of the optical cable having the above-described configuration, the outer sheath 18 is covered with the outer sheath fixing portion 33, and the crimping portion 32 is crimped over the entire outer periphery of the outer sheath fixing portion 33 from the outer periphery. The entire circumference of the jacket 18 can be crimped uniformly without damaging the wire 16 or the jacket 18.

  The optical module 10 of the present embodiment includes an optical cable 11 having an intervening layer (tensile fiber) 16 around the optical fiber core wire 14 and an outer sheath 18 on the outer periphery of the intervening layer 16, and the optical fiber core wire 14. And a metal housing 20 that houses a circuit board 22 on which the photoelectric conversion unit 21 to be connected is mounted. In addition, the optical module 10 is caulked to the outer peripheral surface of the outer casing fixing portion 33, the cylindrical main body portion 31 having the outer casing fixing portion 33 for fixing the outer casing 18, the cable insertion passage 35 for inserting the optical fiber. An optical cable terminal fixture 30 having a crimping portion 32 is provided. In the optical module 10, the optical fiber core wire 14 is inserted into the cable insertion path 35, the jacket 18 is covered with the jacket fixing portion 33, and the crimping portion 32 extends from the outer periphery to the outer periphery of the jacket fixing portion 33. It is crimped over the entire circumference of the surface.

  According to the optical module 10 having the above-described configuration, the optical cable 11 has the metal layer 17 between the tensile fiber 16 and the jacket 18, and the metal layer 17 is interposed between the jacket fixing portion 33 and the jacket 18. 17 is crimped over the entire circumference of the outer peripheral surface of the outer casing fixing portion 33 from the outer periphery of the outer casing 18 by a crimping portion 32 crimped to the outer peripheral surface of the outer casing fixing portion 33. By doing so, the metal layer 17 is firmly and thermally connected to the jacket fixing portion 33, and heat can be released from the housing 20 connected to the jacket fixing portion 33 to the optical cable 11 side. Then, heat can be efficiently released from the metal layer 17 through the jacket 18 to the outside.

  Furthermore, as described above, the optical cable terminal fixture 30 that is thermally connected by soldering the metal layer 17 to the casing 20 is more firmly coupled to the casing 20, so that the casing 20 and the optical cable terminal are connected. The fixture 30 is thermally connected. Thereby, the heat generated in the housing 20 can be dissipated more efficiently from the optical cable terminal fixture 30, and the heat-resistant optical module 10 can be obtained.

  The optical cable terminal fixing structure and the optical module according to the present invention are not limited to the above-described embodiments, and can be appropriately modified and improved.

DESCRIPTION OF SYMBOLS 10 ... Optical module, 11 ... Optical cable, 14 ... Optical fiber core wire, 15 ... Inner tube, 16 ... Intervening layer (tensile strength fiber), 17 ... Metal layer, 18 ... Outer casing, 20 ... Housing, 21 ... Photoelectric conversion part , 22 ... circuit board, 30 ... optical cable terminal fixture, 31 ... body part, 32 ... crimping part, 33 ... jacket fixing part, 34 ... base part, 35 ... cable insertion path, 36 ... concave part, 37 ... inner peripheral surface, 38 ... crimp piece, 39 ... notch

Claims (6)

An optical cable terminal fixing structure having a jacket on the outside of an optical fiber,
A cylindrical main body having a jacket fixing portion whose outer peripheral surface is processed smoothly so as to fix the jacket, and a cable insertion path through which the optical fiber is inserted inside the jacket fixing portion;
An optical cable terminal fixture provided with a crimped portion that is crimped to the outer peripheral surface of the outer jacket fixing portion and whose inner peripheral surface is processed smoothly;
The optical fiber is inserted through the cable insertion path, the outer cover is covered by the outer cover fixing part, and the crimping part is crimped from the outer periphery over the entire outer periphery of the outer cover fixing part. An optical cable terminal fixing structure characterized by comprising: In the optical cable terminal fixing structure according to claim 1,
The crimping part has a notch part adjacent to the crimping piece and the crimping piece at both ends thereof,
An end fixing structure for an optical cable, wherein the crimping piece on the other end side is crimped on the cutout portion on the one end side. In the terminal fixing structure of the optical cable according to claim 1 or 2,
The optical cable has a metal layer outside the optical fiber and inside the jacket;
An end fixing structure for an optical cable, wherein the metal layer is put on the outer cover fixing portion. An optical cable having a jacket on the outside of the optical fiber, and a metal housing that houses a circuit board on which a photoelectric conversion unit to which the optical fiber is connected is mounted,
An optical module in which a terminal portion of the optical cable is fixed to one end of the housing,
A cylindrical main body having a jacket fixing portion whose outer peripheral surface is processed smoothly so as to fix the jacket, and a cable insertion path through which the optical fiber is inserted inside the jacket fixing portion;
A crimping part that is crimped to the outer peripheral surface of the outer jacket fixing part and whose inner peripheral surface is processed smoothly, and an optical cable terminal fixture,
The optical fiber is inserted through the cable insertion path, the outer cover is covered by the outer cover fixing part, and the crimping part is crimped from the outer periphery over the entire outer periphery of the outer cover fixing part. An optical module. The optical module according to claim 4,
The optical cable has a metal layer outside the optical fiber and inside the jacket;
The optical module is characterized in that the metal layer is placed on the outer cover fixing portion and is pressed from the outer periphery of the outer cover to the outer peripheral surface of the outer cover fixing portion by the crimping portion. The optical module according to claim 5,
An optical module, wherein the metal layer is soldered to the housing.

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