JP5867786B2 - Optical fiber cable end processing structure - Google Patents

Description

  The present invention relates to a terminal processing structure for coupling an optical fiber cable formed by inserting an optical fiber and a tensile material into a sheath to an optical connector.

  For example, in an optical communication system used in a vehicle such as an automobile, an optical connector is used for connection between optical fiber cables or connection between an optical fiber cable and an optical transceiver module installed on a circuit board. In an operation of routing an optical fiber cable in this type of optical communication system, the optical fiber cable may be pulled and tension may be applied between the optical fiber cable and the optical connector. For this reason, the optical fiber cable is required to be firmly coupled so as not to be disconnected from the optical connector for a vehicle such as an automobile.

  By the way, a relatively short optical fiber cable used in a vehicle or indoors generally has a structure in which a tensile strength material such as an optical fiber and an aramid fiber is accommodated in a central portion and the periphery thereof is protected by a sheath. In such a configuration, since the tensile strength of the entire optical fiber cable is borne by the tensile strength material, it is necessary to sufficiently increase the fixing strength of the tensile strength material to the optical connector. Further, when an operator pulls the optical fiber cable in an actual routing operation, it is the sheath that the operator pulls directly. In this case, since the tensile strength material and the sheath are not integrated, only the sheath may fall out of the optical connector even if the strength strength of the tensile strength material is sufficient. Therefore, it is necessary to fix both the tensile strength material and the sheath to the optical connector.

  As a coupling structure between an optical fiber cable and an optical connector, for example, a configuration described in Patent Document 1 has been proposed. However, this has a problem that the number of parts and the number of processing steps are large because the tensile strength material and the sheath portion are caulked by separate members. Further, for example, a configuration as described in Patent Document 2 has been proposed. However, since the caulking pedestal is omitted, there is a possibility that sufficient strength cannot be obtained with respect to fixing the sheath.

JP-A-4-97108 JP 2008-191410 A

  Therefore, the inventors of the present invention provide an optical fiber cable with an engagement member that can be coupled to an optical connector, has a reduced number of parts and processing steps, and increases the coupling strength between the engagement member and the optical fiber cable (sheath and tensile material). Proposed a configuration that is possible (unpublished at the time of filing this application). As shown in FIG. 12, the outer ring 120 that can be coupled to the optical connector is fixed to both the sheath 101 and the tensile strength material 102 of the optical fiber cable 100. Specifically, one end side (large diameter portion 121) of the outer ring 120 is overlaid on the outer periphery of the inner ring 110 attached to the outer periphery of the end portion of the sheath 101, and the other end side (small diameter portion 122) is the sheath. It is mounted on the outer periphery of 101 while being compressed. Thereby, the tensile strength material 102 drawn out from the slit 103 formed in the sheath 101 is sandwiched and fixed between the large-diameter portion 121 of the outer ring 120 and the inner ring 110, and the diameter of the outer ring 120 is fixed. The small portion 122 bites into the sheath 101 and is fixed.

  In such a configuration, since the outer ring 120 is configured to fix both the tensile strength material 102 and the sheath 101, the coupling strength between the outer ring 120 and the optical fiber cable 100 is improved. However, when a large tensile force is applied to the tensile material 102, the tensile material 102 may slide between the outer ring 120 and the inner ring 110, and there is still room for improvement.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide an optical fiber cable end processing structure capable of further increasing the fixing strength of a tensile strength material.

The present invention made to solve the above-mentioned problems is a fiber optic cable terminal processing structure in which an optical fiber and a tensile material are inserted into a sheath, and the tip portion of the tensile material formed on the sheath can be pulled out. A slit, an inner ring fitted to the distal end portion of the sheath and pulled out from the slit, the distal end of the tensile strength material being addressed to the outer peripheral surface, and the inner ring being caulked to the outside of the inner ring An outer ring having a large-diameter portion for sandwiching the tensile material and a small-diameter portion that is caulked to the sheath, and the outer peripheral surface of the inner ring is positioned at least at a portion to which the tensile material is applied. A plurality of engaging grooves extending along the circumferential direction of the inner ring are intermittently formed along the axial direction of the optical fiber cable, and the outer ring has Several engaging ribs are formed such that at least one of them enters the engaging groove when crimping of the outer ring, the axial direction of the optical fiber cable of the engagement groove of the plurality of The formation pitch along the direction and the formation pitch along the same direction of the plurality of engagement ribs are characterized in that they are set to be different from each other.

According to the present invention, since at least one of the plurality of engagement ribs provided on the outer ring to the inner ring a plurality of the engaging groove provided on the outer circumferential surface of the is configured to enter, tensile strength The material is sandwiched so as to meander between the engagement groove and the engagement rib, and even when a tensile force is applied to the strength material in the axial direction of the optical fiber cable, the strength material becomes difficult to come off. . That is, the fixing strength between the inner ring and the outer ring and the tensile strength material is increased.

In addition, a plurality of engagement grooves are intermittently formed along the axial direction of the optical fiber cable, and the caulking type that forms the engagement rib on the outer ring presses the outer ring from the outer peripheral side to engage the engagement rib. when the plurality of the pressing projection extending along the circumferential direction of the outer ring for forming is formed, when mounting the outer circumference of the inner ring outer ring is still engaging rib on the outer ring Is not formed and is in a flat state, so that the mounting operation can be performed smoothly. Then, after the outer ring is mounted on the inner ring, the engagement ribs are formed by compression with a caulking die, whereby the tensile strength material can be firmly fixed between the outer ring and the inner ring.

In addition, the formation pitch of the plurality of engagement grooves along the axial direction of the optical fiber cable and the formation pitch of the plurality of engagement ribs along the same direction are set to be different from each other. Even if the caulking position with the ring is slightly shifted in the axial direction of the optical fiber cable, any of the plurality of engagement grooves and the plurality of engagement ribs can be engaged with each other. Can be high. In addition, variation in fixed strength between products can be reduced.

The disassembled perspective view of the terminal processing structure of the optical fiber cable concerning the reference example of this invention Sectional drawing in the surface containing the slit of the end processing structure of the optical fiber cable concerning the reference example of this invention It is a perspective view which shows the manufacturing process of the end processing structure of the optical fiber cable concerning the reference example of this invention, and is a perspective view which shows the state which penetrated the outer ring to the sheath The perspective view which shows the state which similarly pulled out the tensile material from the slit The perspective view which shows the state which similarly assembled | attached the inner ring to the sheath The perspective view which shows the state which arrange | positioned the tensile material along the inner ring similarly The perspective view which shows the state which similarly attached the outer ring to the outer periphery of the inner ring The perspective view which shows the state which similarly compressed the outer ring and formed the engagement rib The partially expanded sectional view in the surface containing the slit of the end processing structure of the optical fiber cable concerning the reference example of this invention Sectional drawing which shows an example of the coupling | bond part of an optical fiber cable and an optical connector The partially expanded sectional view in the surface containing the slit of the terminal processing structure of the optical fiber cable concerning embodiment of this invention Longitudinal cross-sectional view of a conventional optical fiber cable with an engagement member, including the slit

< Reference example >
Reference examples of the present invention will be described in detail with reference to the drawings. In the following description, the “axial direction” of each member constituting the end processing structure of the optical fiber cable refers to the longitudinal direction of the optical fiber cable based on the state where the end processing structure of the optical fiber cable according to this reference example is completed. And

As shown in the exploded perspective view of FIG. 1, the end structure 10 of the optical fiber cable according to the present reference example includes an optical fiber cable 11, an inner ring 20, and an outer ring 30.

Various conventionally known optical fiber cables can be applied to the optical fiber cable 11. For example, a configuration in which the tensile strength material 13 and the optical fiber 14 are inserted into the sheath 12 is preferable. The sheath 12 is formed of various resin materials such as polyvinyl chloride, polyethylene, and polypropylene, has a tube shape, and can be elastically or plastically deformed when a compressive force is applied from the outer periphery. The tensile strength material 13 is a member for preventing the optical fiber 14 from being broken when an excessive tension is applied to the optical fiber cable 11. For example, a large number of fibers formed of aramid fibers are surrounded by the outer periphery of the optical fiber 14. It is arranged in. The optical fiber 14 is a member that transmits an optical signal, and various conventionally known optical fibers are applied, and one optical fiber 14 is inserted into the sheath 12 in this reference example . In addition, a single slit 15 that penetrates the inside and outside of the sheath through the axial center is formed at the end of the sheath 12 with a predetermined length from the end surface 12A along the axial direction.

  The inner ring 20 is a substantially cylindrical member formed by cutting a metal material, for example, and the through hole 21 has substantially the same diameter as the sheath 12 of the optical fiber cable 11 so that the optical fiber cable 11 can be inserted. It is said that. The length in the axial direction is slightly shorter than the slit 15 described above. Further, on the outer peripheral surface, three engagement grooves 22 that form an annular shape along the circumferential direction are formed at equal intervals in the axial direction.

  On the other hand, the outer ring 30 is formed by, for example, drawing a metal material, and is caulked to the outside of the inner ring 20 so that the tensile strength material 13 of the optical fiber cable 11 can be sandwiched between the inner ring 20 and the outer ring 30. The portion 31 and the small-diameter portion 35 that is crimped to the sheath 12 of the optical fiber cable 11 are integrally formed side by side in the axial direction. The large-diameter portion 31 has a substantially cylindrical shape having a through hole 32 extending in the axial direction. The through hole 32 is externally fitted to the inner ring 20 while holding the tensile strength material 13 between the inner ring 20 and the inner ring 20. In order to be possible, the diameter is slightly larger than the outer diameter of the inner ring 20. The length in the axial direction is slightly longer than the length of the slit 15 described above. The small-diameter portion 35 is also formed in a substantially cylindrical shape having a through hole 36 extending in the axial direction. The through hole 36 is substantially the same as the sheath 12 of the optical fiber cable 11 so that the optical fiber cable 11 can be inserted. The diameter is a slightly larger diameter.

  The outer ring 30 also functions as a coupling portion between the optical fiber cable 11 and the optical connector. For example, the female optical connector 50 located on the left side in FIG. 10 includes a lower housing 51 and an upper housing 52, and a lock protrusion (not shown) provided on the lower housing 51 and a lock receiver (not shown) provided on the upper housing 52. It becomes the structure assembled | attached integrally by engaging a part. In order to connect the female-side optical connector 50 and the optical fiber cable 11, the outer ring 30 of the optical fiber cable 11 is placed in the lower-side outer ring receiving groove 53 of the lower housing 51 in an open state, The upper housing 52 is assembled to the lower housing 51, and the outer ring 30 is secured to be connected to the lower housing 51.

  A configuration in which the inner ring 20 is formed of a material harder than the large-diameter portion 31 of the outer ring 30 is suitable. For example, a configuration in which the inner ring 20 is formed of a copper alloy such as stainless steel or brass and the outer ring 30 is formed of aluminum or an aluminum alloy is suitable. With such a configuration, the outer ring 30 can be firmly crimped to the inner ring 20.

Next, the manufacturing method of the terminal structure 10 of the optical fiber cable concerning this reference example is demonstrated.

  First, as shown in FIG. 3, the optical fiber cable 11 is inserted into the through holes 35 and 32 of the outer ring 30 so that the large-diameter portion 31 of the outer ring 30 is on the end surface 12A side (left side in the figure) of the optical fiber cable 11. Then, the outer ring 30 is set at a retracted position where the slit 15 is exposed.

  Next, as shown in FIG. 4, the tensile strength material 13 is bundled and pulled out to the outside in the radial direction through the slit 15 of the sheath 12.

  Next, as shown in FIG. 5, the inner ring 20 is fitted to the outer periphery of the sheath 12 of the optical fiber cable 11. At this time, the inner ring 20 is pushed in the axial direction (right side in the figure) of the optical fiber cable 11 until the end surface 20A of the inner ring 20 and the end surface 12A of the sheath 12 are flush with each other. When the inner ring 12 is thus fitted to the outer periphery of the sheath 12, the slit 15 formed in the sheath 12 is prevented from expanding. Further, the tensile strength material 13 is pushed into the bottom 15A side of the slit 15 by the inner ring 20, and is pulled out from the portion of the slit 15 slightly exposed from the edge of the inner ring 20 to the outside of the sheath 12 (FIG. 2).

  Next, as shown in FIG. 6, the tensile material 13 drawn out is spread while being tilted along the outer surface of the inner ring 20, and then the outer ring 30 in the retracted position is moved to the end side of the optical fiber cable 11 ( The large diameter portion 31 is fitted to the outer periphery of the inner ring 20 (see FIG. 7). At this time, the outer ring 30 is moved toward the end of the optical fiber cable 11 until the end face 30A of the outer ring 30 and the inner ring 20 and the end faces 20A, 12A of the sheath 12 are flush with each other. Then, the tensile strength material 13 drawn out from the slit 15 is sandwiched between the inner peripheral surface of the large-diameter portion 31 of the outer ring 30 and the outer peripheral surface of the inner ring 20. Further, the small-diameter portion 35 of the outer ring 30 is located in a portion of the sheath 12 that is slightly deeper than the bottom portion 15A of the slit 15 (see FIG. 2).

  Next, the entire outer ring 30 is compressed in the radial direction by a crimping device (not shown). The caulking type of the caulking device is composed of an upper die and a lower die having two types of semi-cylindrical compression surfaces with different diameters that can compress the large diameter portion 31 and the small diameter portion 35 of the outer ring 30 in the radial direction. . The upper mold is formed with three pressing protrusions for pressing the outer ring 30 from the outer peripheral side to form an engagement rib 33 described later so as to extend along the circumferential direction of the outer ring 30. The formation pitch of the pressing protrusions is set to be equal to the formation pitch of the three engagement grooves 22 of the inner ring 20.

  The optical fiber cable 11, the inner ring 20, and the outer ring 30 assembled as shown in FIG. 7 are arranged on the lower mold of such a caulking device so that the slit 15 of the sheath 12 is positioned at the center of the upper mold. Close the caulking type. Then, the outer ring 30 receives a compressive force in the radial direction by the caulking die, and is reduced in diameter while being plastically deformed. In the large-diameter portion 31, as shown in FIG. 8, a caulking projection 34 that protrudes radially outward is formed in the caulking-type butted portion along the axial direction. Further, a portion (upper side in the figure) of the large-diameter portion 31 that is compressed into the upper mold is partially pushed in by the pressing protrusions formed at the same pitch as the engaging grooves 21 of the inner ring 20 described above, Three engagement ribs 33 are pushed out to the peripheral surface side. As shown in FIG. 9, these engagement ribs push the tensile material 13 into the engagement groove 22 of the inner ring 20, so that the tensile material 13 engages the engagement rib 33 of the outer ring 30 with the inner ring 20. It is pinched so as to meander between the grooves 22, whereby the entire tensile strength material 13 is firmly fixed so as not to slip.

  Further, the small diameter portion 35 of the outer ring 30 is plastically deformed so as to be smaller than the outer diameter of the sheath 12, so that it bites into the sheath 12 and is firmly fixed.

As described above, according to the end processing structure 10 of the optical fiber cable of the present reference example , the outer ring 30 and the inner ring 20 firmly hold the tensile strength material 13 by the uneven engagement between the engagement groove 21 and the engagement rib 33. Since it can be pinched, the coupling strength of the outer ring 30, the tensile strength material 13, and the inner ring 20 is increased.
< Embodiment >

The optical fiber cable end processing structure 40 of the present embodiment is different from the reference example in the engagement groove 42 formed in the inner ring 41. For other parts not described are similar to Reference Example, the component parts similar to those of the reference example are denoted by the following same reference numerals.

  The inner ring 41 in the end processing structure 40 of the optical fiber cable of the present embodiment has a configuration in which four engagement grooves 42 having a narrower formation pitch than the inner ring 20 of the first embodiment are formed.

  When the outer ring 30 is fitted to the outer periphery of the inner ring 40, a slight positional deviation (error) may occur in the axial direction (see FIG. 11), but the engagement of the inner ring 41 as in this embodiment. When the formation pitch of the joint grooves 42 and the formation pitch of the engagement ribs 33 of the outer ring 30 are set to be different from each other, any of the plurality of engagement ribs 33 is formed on the plurality of engagement grooves 42. Since the concave / convex engagement is possible in any one of them, the tensile strength material 13 can be firmly held in the portion (engagement groove 42A and engagement rib 33A in FIG. 11) where the concave / convex engagement has been performed. . As a result, the variation in the fixing strength between products is reduced.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) The number of engagement grooves and engagement ribs is not limited to the above embodiment, and can be set arbitrarily. Further, in the above embodiment, the engagement rib 33 of the outer ring 30 is provided only on the half circumference centered on the slit 15. However, for example, the engagement rib 33 may be provided on the entire circumference. In short, the tensile strength material is pulled out from the sheath. It may be formed in any range as long as it is formed in a portion to be formed (portion in which the slit is formed) and can firmly fix the tensile strength material. Further, the engagement groove 22 of the inner ring 20 is not limited to the entire circumference, and may be formed only around the slit.

  (2) In the above embodiment, an example in which one slit 15 is formed in the sheath 12 has been shown, but any number of slits may be formed. At this time, in the configuration in which the plurality of slits are formed, it is preferable that the amount of the tensile material drawn from each slit is the same. Further, as described above, it is preferable to form the engagement ribs of the outer ring and the engagement grooves of the inner ring at the positions where the slits are formed.

  (3) In the above embodiment, the outer ring 30 is drawn. However, it may be cut. In the conventional configuration, drawing is difficult to maintain the hardness of the material used, and costly cutting is performed. However, in the configuration of the present invention, even a relatively soft material can be used against a tensile strength material. As a result, a high fixing force can be realized, so that drawing can be performed.

  (4) In the above embodiment, the inner ring 20 and the outer ring 30 are formed of different materials, but may be formed of the same material. Also, the processing method is not limited to drawing or cutting, and other methods can be employed.

  (5) In the above-described embodiment, the outer ring is a cylindrical member. However, for example, a member having a C-shaped cross section having a slit in the axial direction may be used.

  (6) The optical fiber cable is not limited to the above configuration. Any configuration can be applied as long as the optical fiber cable includes a sheath and a tensile strength material.

DESCRIPTION OF SYMBOLS 10, 40 ... End processing structure 11 of optical fiber cable 11 ... Optical fiber cable 12 ... Sheath 13 ... Tensile material 14 ... Optical fiber 15 ... Slit 20, 41 ... Inner ring 22, 42 ... Engaging groove 30 ... Outer ring 31 ... Large diameter part 33 ... engaging rib 35 ... small diameter part

Claims (1)

An optical fiber cable end treatment structure in which an optical fiber and a tensile material are inserted into a sheath, and is fitted to the distal end of the sheath, and a slit formed in the sheath and capable of pulling out the distal end of the tensile material. An inner ring in which the tip of the tensile material drawn out from the slit is directed to the outer peripheral surface, a large diameter portion that is crimped to the outside of the inner ring and sandwiches the tensile material between the inner ring and the sheath An outer ring having a small diameter portion that can be crimped to
On the outer peripheral surface of the inner ring, a plurality of engaging grooves intermittently extending along the axial direction of the optical fiber cable are located at least at a portion to which the tensile material is addressed and extend along the circumferential direction of the inner ring. As it is formed,
In the outer ring, a plurality of engagement ribs are formed so that at least one of them enters the engagement groove when the outer ring is crimped ,
The formation pitch of the plurality of engagement grooves along the axial direction of the optical fiber cable and the formation pitch of the plurality of engagement ribs along the same direction are set to be different from each other. Optical fiber cable end processing structure.

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