JP2016206350A - Optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable which prevents a wrapping member from being damaged when a tear string is pulled out.SOLUTION: A wrapping member 7 is wrapped such that two end sections thereof in a width direction thereof overlaps, creating an overlapped section 15. The overlapped section 15 is located between one of tear strings 11 and one of tension members 9 in a circumferential direction in a cross-section perpendicular to a longitudinal direction of an optical fiber cable 1. In other words, the overlapped section 15 is positioned between one of the tear strings 11 and one of the tension members 9 in such a way that an opening end (of the wrapping member) surely faces a side of the tension member 9.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical fiber cable composed of a plurality of optical fiber core wires.

  In recent years, with the widespread use of the Internet, FTTH (Fiber To The Home) that realizes a high-speed communication service by directly drawing an optical fiber into a general household is rapidly expanding. In general, an optical fiber cable used for FTTH accommodates a collection of optical fibers so as to be compatible with large-capacity data communication.

  As such an optical fiber cable, an optical fiber cable that does not use a slot rod and is covered with a jacket provided with two tension members has been proposed. For example, a yarn (polyester fiber, aramid fiber, PP fiber, or the like) is gathered as a buffer material on the outer periphery of the optical fiber ribbon, and a sheath is coated on the outer periphery (Patent Document 1).

  In addition, there is an optical fiber cable in which a press-wound tape is vertically attached to the outer periphery of an optical fiber ribbon, and a sheath is coated on the outer periphery (Patent Document 2).

JP 2006-337581 A JP 2001-343571 A

  On the other hand, in the slotless type optical fiber cable as described above, in order to take out the optical fiber core wire in the middle portion of the cable, it is necessary to cut the cable jacket using a tear string. At this time, it is not a problem if the tear string is pulled out perpendicular to the cable cross section (the tear angle is 0 °). There is. If the presser winding is damaged, the inner optical fiber core wire is exposed and the optical fiber core wire may be damaged.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an optical fiber cable capable of preventing damage to a presser winding member when a tear string is pulled out.

  In order to achieve the above-described object, the present invention provides a plurality of optical fiber cores, a press-winding member that is vertically wound around the outer periphery of the plurality of optical fiber cores, and a direction perpendicular to the longitudinal direction of the optical fiber cores. In a cross section, in a direction perpendicular to the longitudinal direction of the optical fiber core wire in a direction perpendicular to the longitudinal direction of the optical fiber core wire in a direction perpendicular to the longitudinal direction of the optical fiber core wire, A pair of tear strings provided so as to face each other across the presser winding member, and an outer cover provided so as to cover the tension member, the tear string and the presser roll member, and an end of the press roll member A lap portion where the portions overlap each other is formed in the longitudinal direction of the optical fiber core and is circumferential in a cross section perpendicular to the longitudinal direction of the optical fiber core On the other hand, the wrap portion is disposed between one of the tear strings and one of the tension members, and the opening direction of the wrap portion is directed to the one tension member side. An optical fiber cable.

  The optical fiber cable is preferably a slotless type.

  According to the present invention, the wrap portion where the ends of the presser winding member overlap each other is disposed between the tear string and the tension member, and the opening direction of the wrap portion is directed to the tension member side. It is possible to prevent damage to the presser winding member without entering the opening portion of the presser winding member.

  Such an effect is particularly effective in a slotless type optical fiber cable. For example, in a slotless type optical fiber cable, a tear string can easily enter the opening portion of the presser winding member. In the present invention, even in such a case, it is possible to prevent the torn string from entering the opening portion of the presser winding member and to prevent the presser winding member from being damaged.

  ADVANTAGE OF THE INVENTION According to this invention, the optical fiber cable which can prevent damage to a holding | suppressing winding member at the time of pulling out a tear string can be provided.

1 is a cross-sectional view showing an optical fiber cable 1; It is a figure which shows the state which pulls out the tear string 11 from the optical fiber cable 1, (a) is a perspective view, (b) is sectional drawing. The perspective view which shows the state which pulls out the tear string 11 from the optical fiber cable 1. FIG. (A) is sectional drawing which shows the state which pulls out the tear string 11 from the optical fiber cable 1, (b) is a figure which shows the pull-out direction of the tear string 11. FIG. (A) is sectional drawing which shows the state which pulls out the tear string 11 from the optical fiber cable 1a, (b) is a figure which shows the pull-out direction of the tear string 11. FIG. 2 is a cross-sectional view showing an optical fiber cable 30. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an optical fiber cable 1. The optical fiber cable 1 is a slotless optical fiber cable that does not use a slot, and includes a plurality of optical fiber core wires 3, a presser winding member 7, a tension member 9, a tear string 11, a jacket 13 and the like. In the following description, an assembly of a plurality of optical fiber cores 3 is simply referred to as an optical fiber unit 5.

  A presser winding member 7 is provided on the outer periphery of the optical fiber unit 5. The presser winding member 7 is disposed so as to collectively cover the plurality of optical fiber units 5 by vertical auxiliary winding. In other words, the longitudinal direction of the press-winding member 7 is substantially aligned with the axial direction of the optical fiber cable 1, and the optical fiber unit 5 is vertically attached so that the width direction of the press-winding member 7 is the circumferential direction of the optical fiber cable 1. It is wound.

  A jacket 13 is provided on the outer periphery of the presser winding member 7. The jacket 13 is a layer for covering and protecting the optical fiber cable 1. In the cross section perpendicular to the longitudinal direction of the optical fiber cable 1, a pair of tension members 9 are provided inside the jacket 13 at positions facing each other with the optical fiber unit 5 interposed therebetween. Further, a tear string 11 is provided in a direction substantially orthogonal to the opposing direction of the tension member 9 so as to face each other with the presser winding member 7 interposed therebetween. The tension member 9 and the tear string 11 are embedded in the jacket 13.

  Here, the end portions in the width direction of the presser winding member 7 are wrapped together to form a wrap portion 15. The wrap portion 15 has one tear string 11 (for example, the upper tear string 11 in the figure) and one tension member 9 (for example, the left side in the figure) with respect to the circumferential direction in the cross section perpendicular to the longitudinal direction of the optical fiber cable 1. It is arranged between the tension member 9) (range A in the figure).

  The wrap portion 15 is disposed between the one tear string 11 and the one tension member 9 because the position of the end surface in the width direction of the presser winding member 7 located on the outer peripheral side is the one described above. It is arranged between the tear string 11 and one tension member 9. In this case, the position of the end surface in the width direction of the presser winding member 7 also includes being positioned immediately below the tear string 11 (inner peripheral side) and directly below the tension member 9 (inner peripheral side).

  Further, the opening direction of the wrap portion 15 is directed to the tension member 9 side. Here, the opening direction of the wrap portion 15 is a direction in which an end portion of the presser winding member 7 that wraps on the outer peripheral side of the wrap portion 15 opens to the outer peripheral side, and the width of the presser winding member 7 positioned on the outer peripheral side. This is the direction in which the direction end face faces. That is, the wrap portion 15 is disposed between the one tear string 11 and the one tension member 9, and at this time, the wrap portion 15 is disposed such that the opening direction is always directed to the tension member 9 side. In the example shown in the figure, the wrap portion 15 is positioned between the upper tear string 11 and the left tension member 9 so that the opening direction is directed to the left tension member 9 side.

  Next, the process of pulling out the tear string 11 will be described in detail. FIG. 2A is a perspective view showing a state in which the tear string 11 is pulled out from the optical fiber cable 1, and FIG. 2B is a cross-sectional view perpendicular to the longitudinal direction of the optical fiber cable 1. As shown in FIGS. 2 (a) and 2 (b), in this example, the tear string 11 is drawn straight to the outer peripheral side in the radial direction with respect to the center of the optical fiber cable 1 (C in the figure). .

  That is, the tear string 11 is drawn to the outer peripheral side in the same direction as the center line (D in the drawing) of the optical fiber cable 1 passing through the tear string 11. Hereinafter, the pulling angle of the tear string 11 at this time is 0 °.

  As shown in FIG. 2 (b), the tear string 11 is pulled out while tearing the outer jacket 13, but at this time, the tear string 11 does not come into contact with another structure (for example, the presser winding member 7). Absent. Therefore, if the pulling angle of the tear string 11 is 0 °, the tear string 11 can be pulled out without any problem, and then a branching operation such as taking out the inner optical fiber core 3 can be performed.

  3 is a perspective view showing a state in which the tear string 11 is pulled out from the optical fiber cable 1, and FIG. 4A is a cross-sectional view perpendicular to the longitudinal direction of the optical fiber cable 1. In FIG. 3 and FIG. 4A, the tear string 11 is drawn out to the outer peripheral side in the radial direction at a predetermined angle with respect to the center of the optical fiber cable 1.

  Specifically, as shown in FIG. 4A, the tear string 11 is in the direction of angle G (F in the figure) with respect to the center line (D in the figure) of the optical fiber cable 1 passing through the tear string 11. It is pulled out to the outer peripheral side. Hereinafter, the pulling angle of the tear string 11 at this time is represented by G.

  As described above, the tear string 11 is pulled out while tearing the outer jacket 13. At this time, the tear string 11 is pulled out along the presser winding member 7. Specifically, the tear string 11 passes through the gap between the outer cover 13 and the presser winding member 7 (E in the figure), and tears the outer cover 13 from the vicinity of the tension member 9 toward the outer side in the radial direction. It is pulled out (F in the figure).

  The pulling angle of the tear string 11 is ± 90 ° at the maximum. For example, even if the tear string 11 is pulled out at an angle of 90 ° or more, the pulling direction of the tear string 11 is regulated by the tension member 9, and therefore the angle at which the tear string 11 is pulled out along the outer periphery of the presser winding member 7. This is because the maximum angle is 90 °. That is, when the pull-out angle of the tear string 11 is ± 90 °, the length that the tear string 11 is pulled out along the outer peripheral surface of the presser winding member 7 is the longest.

  FIG. 4B is a conceptual diagram showing a pulled state of the tear string 11 when the tear string 11 is pulled out at a pulling angle of 90 °. In addition, in FIG.4 (b), illustration is abbreviate | omitted about the structure of the jacket 13 and tension member 9.

  In the example shown in the figure, the tear string 11 is disposed above the wrap portion 15, and the tension member 9 (not shown) is positioned below the wrap portion 15. That is, the tear string 11 and the tension member 9 are disposed with the wrap portion 15 interposed therebetween.

  First, when the tear string 11 is pulled out to the tension member 9 (not shown) at a pulling angle of 90 °, a part of the tear string 11 is pulled out along the presser winding member 7 as described above (H1 in the figure). Further, when the tear string 11 is pulled out in the same direction, the tear string 11 is pulled out in a pulling direction along the outer surface of the presser winding member 7 from a predetermined embedding position (H2 and H3 in the figure).

  At this time, the tear string 11 gets over the wrap portion 15 of the presser winding member 7. In the example shown in the figure, in the region I, the tear string 11 is pulled out so as to slide on the lap portion 15 from the upper side to the lower side.

  In the present invention, since the opening direction of the wrap portion 15 is the tension member 9 side, the tear string 11 rides on the wrap portion 15 from the direction opposite to the opening direction and is pulled out in the opening direction. Therefore, the tear string 11 does not enter into the gap between the inner and outer presser winding members 7 in the wrap portion 15.

  In FIG. 4A, when the tear string 11 is pulled out in the −90 ° direction, the tear string 11 does not come into contact with the wrap portion 15. For this reason, the tear string 11 does not enter the gap between the inner and outer presser winding members 7 in the wrap portion 15.

  Thus, in the present invention, since the opening direction of the wrap portion 15 is always directed to the side where the tear string 11 is pulled out, the tear string 11 is caught by the wrap portion 15 of the presser winding member 7, 15 does not open or the presser winding member 7 is not damaged.

  On the other hand, FIG. 5 (a) is a cross-sectional view showing the optical fiber cable 1a in which only the opening direction of the wrap portion 15 is opposite, and FIG. 5 (b) shows that the tear string 11 is pulled out at a pulling angle of 90 °. It is a conceptual diagram which shows the pulling-out state of the tear string 11 at the time of hitting. In FIG. 5B, the illustration of the configuration of the jacket 13 and the tension member 9 is omitted.

  As described above, when the tear string 11 is pulled out toward the tension member 9 (not shown) at a pulling angle of 90 °, a part of the tear string 11 is pulled out along the presser winding member 7 (E and E in FIG. 5A). J1 in FIG. 5B. Further, when the tear string 11 is pulled out in the same direction, the tear string 11 is pulled out in the pull-out direction along the outer surface of the presser winding member 7 from a predetermined embedded position (J2 in FIG. 5B). , J3).

  At this time, the tear string 11 gets over the wrap portion 15 of the presser winding member 7. In the example shown in the figure, in the region K, the tear string 11 is pulled out so as to slide on the lap portion 15 from above to below.

  At this time, since the opening direction of the wrap portion 15 is the tear string 11 side, the tear string 11 rides on the wrap portion 15 from the opening direction and is pulled out to the opposite side to the opening direction. Therefore, the tear string 11 may enter the gap between the inner and outer presser winding members 7 in the wrap portion 15.

  When the tear string 11 enters the mouth opening portion of the wrap portion 15, the presser winding member 7 may be opened or damaged, and the optical fiber core wire 3 may jump out. For this reason, there exists a possibility that the optical fiber core wire 3 may be damaged.

  In the present invention, since the opening direction of the wrap portion 15 is directed to the side from which the tear string 11 is pulled out, it is possible to prevent the presser winding member 7 from being damaged when the tear string 11 is pulled out.

  As described above, the position of the piercing portion may be within a range of 90 ° from the position of the tear string 11 to the tension member 9, but the position of the piercing portion is in the longitudinal direction of the optical fiber cable 1. Since the direction of the tear string 11 is 0 ° and the direction of the tension member 9 is 90 °, for example, it is desirable to design the position of the mouth portion in a range of 15 to 75 °. Moreover, since the direction where the distance of the tearing cord 11 and a mouth opening part (lap | wrap part) is separated can suppress the damage of the opening part vicinity by the tearing cord 11, it is 45-75 degree more desirably. It is desirable to design the position of the mouth opening in the range.

  As described above, according to the present embodiment, since the opening direction of the wrap portion 15 is directed to the side where the tear string 11 is pulled out, the presser winding member 7 is damaged when the tear string 11 is pulled out. Can be prevented.

  In particular, the slotless type optical fiber cable 1 is apt to be crushed by the cushioning material or the like inside the wrapping member 7, but according to the present invention, even if the wrapping member 7 is crushed, the tear string 11 does not enter the opening portion of the presser winding member 7, and the presser roll member 7 can be prevented from being damaged.

  Next, a second embodiment will be described. FIG. 6 is a diagram illustrating the optical fiber cable 30. In the following description, components having the same functions as those of the optical fiber cable 1 are denoted by the same reference numerals as those in FIG.

  The optical fiber cable 30 has substantially the same configuration as the optical fiber cable 1, but is different in that a support line 31 is provided. The optical fiber cable 30 is a self-supporting optical fiber cable, and the support line 31 and the cable portion are connected via a neck portion. The support wire 31 is, for example, a steel wire or the like, and is configured integrally with the cable portion (the same configuration as the optical fiber cable 1) by the jacket 13.

  Also in the optical fiber cable 30, the wrap portion 15 includes one tear string 11 (for example, the tear string 11 on the left side in the drawing) and one tension member with respect to the circumferential direction in the cross section perpendicular to the longitudinal direction of the optical fiber cable 30. 9 (for example, the upper tension member 9 in the figure). Further, the opening direction of the wrap portion 15 is directed to the tension member 9 side. For this reason, when pulling out the tear string 11, it is possible to prevent the presser winding member 7 from being damaged.

  According to the second embodiment, an effect similar to that of the first embodiment can be obtained. Thus, in the present invention, the cross-sectional structure of the optical fiber cable is not limited.

  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.

1, 1a, 30 .... Optical fiber cable 3 ... Optical fiber core 5 ... Optical fiber unit 7 ... Pressing member 9 ... Tension member 11 ... Tear string 13 ... Outside Cover 15 ... Lap 31 ... Support line

Claims (2)

A plurality of optical fiber cores;
A holding member wound longitudinally around the outer periphery of the plurality of optical fiber cores;
In a cross section perpendicular to the longitudinal direction of the optical fiber core wire, a pair of tension members provided at positions facing each other with the presser winding member interposed therebetween;
In a cross section perpendicular to the longitudinal direction of the optical fiber core wire, a pair of tear strings provided so as to be opposed to each other with the pressing roll member interposed therebetween in a direction substantially perpendicular to the opposing direction of the tension member;
A jacket provided so as to cover the tension member, the tear string and the presser winding member;
Comprising
A wrap portion where ends of the presser winding member overlap each other is formed in the longitudinal direction of the optical fiber core wire,
For the circumferential direction in the cross section perpendicular to the longitudinal direction of the optical fiber core wire, the wrap portion is disposed between one of the tear strings and one of the tension members,
An optical fiber cable, wherein an opening direction of the wrap portion is directed toward the one tension member.   The optical fiber cable according to claim 1, wherein the optical fiber cable is a slotless type.

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