JPH04204406A - Manufacturing device for optical fiber cable, slot rod, and cable - Google Patents

Abstract

PURPOSE:To obtain an optical fiber improved in transmission loss even in a state of being wound around a drum by setting a reverse twisted groove so that the minimum connection virtual line takes a gentle helical shape where the twisting direction is reversed at every specified intervals. CONSTITUTION:The shape of a reverse twisted groove 2 is determined so that the minimum connection virtual line 4 connecting alternate reversal points A1 and A2 at the minimum distance along a surface 1a of the slot rod 1 forms a spiral shape of a gentle and long twisting pitch. Therefore, as for the optical fiber cable 10, since the optical fiber 3... is contained inside such reverse twisted groove 2..., the optical fiber 3, as a matter of course, has the minimum connection virtual line 4 alternately connecting reversal points S-Z and forming the gentle helical shape, also. When the optical fiber cable utilizing such a slot rod 1 is wound a multiple number of times around drums, etc., the reflection twisting groove 2 (optical fiber) where the reflecting point comes to the position outside periphery side (1) is sequentially changed. Thus, even in a state where it is wound around the drum, etc., the improved transmission loss of the optical fiber can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber cable, a slot loft used therein, and an optical fiber cable manufacturing apparatus.

[Intelligence that conventional technology and inventions try to solve] Generally,
In order to facilitate branching and connection work during optical fiber cable installation work, S-Z is installed on the surface of the slotted rod.
An optical fiber cable is used in which one or more reverse twist grooves are formed in the shape of the cable and an optical fiber is housed in the groove.

By the way, a conventional optical fiber cable of this type has a reverse twist angle of ±180°, as shown in FIG. 1 (El). That is, FIG. 1(n) representatively shows a conventional slot rod 31 and one of the plurality of S-Z-shaped inverted twisted grooves 32 recessed in its surface. It shows. The optical fiber 33 is housed in the reverse twist groove 32, so in the simplified drawing, the reverse twist groove 32 and the optical fiber 33 therein are shown by a single line that coincides with each other. be. As is clear from the figure, since the reverse twist angle is ±180°, the reverse twist locations of the reverse twist grooves A, , B, , A, .
The imaginary line 34 sequentially connecting . . . is a straight line and parallel to the center line of the slot rod.

When an optical fiber cable using such a conventional slot rod is wound around a drum, the reversal points A+ and B
1. Az... will be located only in a certain direction. For example, in FIG. 4, when it is wound around the drum 35 of radius R,
2... is assumed to be 8 lines,) Reversed point A in Figure 1 (II)
1 comes to the position numbered ■ on the outer periphery side, then the other reversed points B,, A, ... of the same reversed twisting groove 32 (and the optical fiber 33 therein) are also located at the numbered position located in between. come into position. When observing each optical fiber 33 and the inverted P groove 32 in this manner, the inverted portions are located at the same numbered positions in FIG.

In the case of S-Z type reverse twisting, the twist angle changes within the reverse twist pitch P, so if we observe the single optical fiber 33 shown in the first [ffl (It), we can see that the slot rod 31 In which direction should it be curved? In other words, should it be curved so that the inverted points A, B, A2, etc. are at number ■ in Figure 4, or should it be curved so that it is at numbers ■, ■, etc. □- Accordingly, the amount of strain on the optical fiber 33 differs, and the stress applied to the optical fiber 33 also differs. Specifically, numbers ■ to ■■ in Fig. 4 are always inverted points A, , B, , A2.
The amount of strain in the optical fiber 33 with .

Therefore, in the optical fiber cable using the conventional slot rod as described above, the strength and reliability of the optical fiber deteriorate when stored for a long time in a drum-wound state. On the other hand, the drum-wound state causes deterioration in transmission loss of the optical fiber. (Optical fiber transmission loss occurs even in a short period of time.) The purpose of the present invention is to make it possible to obtain good optical fiber transmission loss even in a drum-wound state, and to make it possible to obtain a good optical fiber transmission loss even in a drum-wound state. The point where the distortion state between is the same,
The amount of distortion is sufficiently smaller than that of the conventional method, and high reliability can be obtained even during long-term storage.

[Means for Solving the Problems] The optical fiber cable according to the present invention is an optical fiber cable in which an optical fiber is housed in the reverse twist groove of a slot rod having at least one reverse twist groove. so that the shortest connecting imaginary line along one surface of the slot rod, which connects every reversal point of the reversal twist groove, draws a gentle spiral shape in which the twist direction is reversed every predetermined length. The shape of the second reversal twisting groove was set.

In addition, the throat l-mouth and do of the present invention have at least one inverted twist groove recessed on the surface, and the inverted points of each of the inverted twist grooves are connected at every one of the inverted twist grooves along the surface. The shape of the reversal twist groove was set so that the shortest connecting virtual line drew a gentle spiral shape in which the twist direction was reversed every predetermined length.

The manufacturing apparatus according to the present invention is an apparatus for manufacturing an optical fiber cable including a slot rod having at least one reverse twist groove and an optical fiber housed in the reverse twist groove of the slot rod. A fixed eye plate, a first rotary eye plate, and a second rotary eye plate are sequentially arranged from upstream to downstream to guide the plurality of optical fibers around the slot rod that is fed in the longitudinal direction. However, the first rotary eye plate is configured to rotate at a sufficiently lower speed than the second rotary eye plate which rotates in phase synchronization with the rotary twisting die downstream of the second rotary eye plate.

[Function] With respect to one inverted twist groove of the slot rod and the optical fiber therein, the inverted location is sequentially rotated and shifted to either the right or the left. Furthermore, the direction of rotation is reversed at a sufficiently long distance # (pitch), and the rotation is repeated alternately. Therefore, when an optical fiber cable using such a slot rod is wound around a drum or the like many times, the inverted twisted grooves (optical fiber) whose inverted points are at the positions numbered ■ on the outer circumference side in Figure 4 will be alternated in sequence. do. In other words, when one inverted twisted groove (optical fiber) is observed, the positions of numbers ■■ in FIG. 4, where inverted locations appear one after another, rotate and change.

Therefore, regarding multiple inverted twist grooves, number ■
■...The probability that a reversal point will appear in the position is averaged, and the amount of strain and internal stress of all optical fibers become the same. Therefore, when the optical fiber is wound around a drum or the like and stored for a long period of time, adverse effects such as deterioration in strength and reliability of the optical fiber do not occur. Furthermore, no deterioration in transmission loss occurs when the optical fiber is wound on a drum.

Next, according to the optical fiber cable manufacturing apparatus, the slot rod runs sequentially from upstream to downstream, passing through the center of each of the fixed batten, the first rotary batten, and the second rotary batten, and connects the rotary twisting port. Coming to the dice. On the other hand, a large number of optical fibers are fed out from a feeding bobbin, first guided by a fixed batten,
The rotary twisting die passes through a first rotary perforation plate which rotates slowly, and then through a second rotary perforation plate which rotates sufficiently faster than this and synchronizes with the reversal of the reversal twisting groove of the S-Z shape. At this point, the optical fiber is accurately guided and housed in the reverse twist groove of the slot rod.

If the twist direction of the imaginary line connecting every reverse point of the slot rod's reverse twist groove is reversed every predetermined length, the first rotary eye plate is rotated in accordance with the direction of twist that includes this reversal. I'll let it happen.

〔Example〕

The present invention will be explained below based on illustrated embodiments.

FIG. 2 shows a cross-sectional view of an example of the optical fiber cable 10. 1 is, for example, a slot rod made of plastic and having eight inverted twist grooves 2 . As shown in FIGS. 2 and 3, a plurality of optical fibers 3 are housed in each inverted twist groove 2 of this slot rod. This optical fiber 3 is shown in the case where eight optical fibers are arranged in each reverse twisted groove 2, for example, as a two-core tape type optical fiber.

The slotted rod 1 has a middle 1C bow and a cylindrical ring 5, and the outside of the slotted rod 1 is covered with a presser winding 6 and a sauce 7.

Therefore, in FIG. 1 (1), the slot rod l is shown in a simplified diagram, and in particular, only one of the plurality of reverse twisted grooves 2 is illustrated as a representative example, and S- Let us consider an imaginary line that connects every one of the reversal points A+, B+, Ax, etc. of the reversal twist groove 2 which is recessed in a Z-shape so as to be reversed at a predetermined reversal twist pitch P. That is, the shortest connecting virtual line 4 that connects every other reversal point A and A2 at the shortest distance along the surface 1a of the stontronod l is a gentle □, for example, 10 m-
The shape of the inverted twist groove 2 is determined so as to draw a □ spiral shape with a long twist pitch of 100 m.

Therefore, in the optical fiber cable 10 (see Fig. 2), the optical fibers 3 and 3 are placed in such reverse twist grooves 2.
Since the optical fiber 3 is accommodated, the shortest connecting imaginary line 4, which connects the S-Z reversal points every other way, naturally forms a gentle spiral shape.

The reason why the twisting pitch of this virtual line 4 is set to lOm -100m is that if it is less than 10m, it will be difficult to pull out the optical fiber 3 from the reverse twisting groove 2 of the optical fiber cable IO (during branching work, etc.). If the pitch exceeds 100 m, problems similar to those of the conventional method shown in FIG. It is better to set it to 50m.

By the way, FIG. 5 is a simplified explanatory diagram in which this shortest connecting virtual line 4 is scaled only in the longitudinal direction.

The torsion pitch of the above-mentioned virtual line 4 is indicated by L. Therefore, if the above explanation is expressed as an inequality, 10 m≦L≦100 m, and preferably 20 m≦L≦50 m. As is clear from the figure, the imaginary line 4 is not a spiral shape that simply turns in one direction, but a spiral shape in which the twist direction is reversed every predetermined length (twist pinch) L.

Also, the reverse twist angle of the S-Z shape of this virtual line 4 is ±180'
is desirable, but it is also free to decrease it to ±150° or increase it as desired.

Although not shown in FIG. 1, the shortest connecting imaginary line connecting the next reversal point on the right side outside the drawing and the reversal point B is also the fifth
Draw a similar S-Z type inverted spiral twist shape as shown.

Next, a transmission loss comparison test was conducted between the product according to the present invention and the conventional product.

(1) Implementation product of the present invention (see FIG. 1 (T)): As shown in FIGS. 2 and 3, the slot rod 1 has eight reverse twist grooves 2... Each dimension of 2 is groove bottom width C=2
The groove opening width E=4, the groove depth F=2.5-, and eight optical fibers 3 in the form of a two-core tape are housed in each inverted twist groove 2. The tape-shaped optical fiber 3 had a radius G of 0.7 m and a thickness H of 0.4 m. Figure 1 (1
The reverse twist pitch P shown in ) is 2301, and the reverse twist angle is a small reverse twist groove 2 of about 150''.The outer diameter of the slot rod 1 is 16 mφ, and the outer diameter of the sheath 7 shown in FIG. The diameter is set to 21 mφ.The locus of the shortest connecting virtual line 4 that connects every reversal point of the reversal twist groove 2, as shown in Fig. Set to draw an inverted state with a large degree of °.

(II) Conventional product (see FIG. 1 (II)): The cross-sectional shape and dimensions of the optical fiber cable are the same as those of the product according to the present invention, and the optical fiber in the slot rod is also completely the same.

Then, as shown in Figure 1 ([1), the inversion angle is adjusted to ±1
80", the shape of the reverse twist groove was set so that the temporary LJI 34 was a straight line and parallel to the center line of the optical fiber cable. Reverse twist groove.

ChiP is 230 cabinets. Further, the outer diameter dimension and the sheath outer diameter are the same as those of the product according to the present invention.

The product according to the present invention and the conventional product each have a length of 1
4. Assuming that the drum diameter is 10,000 m and the drum diameter is 10,001-1, that is, in FIG. m was measured.

The measurement results are shown in Tables 1 and 2. In addition, there are 16 optical fibers in each reverse twist groove, and the minimum value (MIN) and maximum value (MAX) of optical transmission loss among them, and
1e core 0) Average 1M (AV E ) is shown.

(Leaving space below) Table 1 2. 4bx selection of the product implementing the present invention (unit: dB/Km) Table 2: I trace iron of the conventional product (unit: dB/Km) Q: If it exceeds 4dB/km, it is considered a defective product. It was judged. 1st
From the table and Table 2, there are no defective products in the products implemented according to the present invention.
In addition, the optical fibers in any of the reverse twist grooves exhibit a small, approximately average transmission loss.On the other hand, in Table 2, the numbers ■ to ■ of the reverse twist grooves correspond to those in Figure 4, and the drum The winding is reversed on the outer circumferential side of the state A+, B+, Bt...
The transmission loss of the optical fiber in the reverse twist groove corresponding to ■■■ was large, and the maximum number of defective fibers occurred (11 cores/16 cores).

It should be noted that the present invention is not limited to the illustrated embodiment, and is of course free to change the design. For example, one slotted rod l may have one inverted twist groove 2, and Fiber 3: The fiber may be a single-core round shape, or may be a tape-type fiber having three or more cores. Furthermore, the S-Z reversal twist angle can be freely selected as long as it is less than ±180°. It is also preferable to assemble a plurality of optical fiber units shown in FIG. 2 into a cable.

Next, regarding the above-mentioned optical fiber cable manufacturing equipment,
explain.

Figure 6 shows an example of this manufacturing device, with a diameter of 11.12°13
, 14 is a stand, which is erected at a predetermined interval between a supply device equipped with a supply bobbin (not shown on the left) and a cable take-up device (not shown on the right). A fixed tube 9 through which the slot rod 1 is inserted is fixed to the stand 11 on the most upstream side, and a disk-shaped tube 9 is fixed to the stand 11 on the most upstream side, and a disk-shaped tube 9 is fixed to the stand 11, into which the slot rod 1 is inserted. A fixed batten 15 is fixed. A cylindrical rotating roll 16 made of a material such as fluorocarbon resin having a low coefficient of friction is fitted onto the fixed cylinder 9 . A plurality of holes 15a through which the optical fibers 3 pass are provided in the fixed eye plate 15 in the circumferential direction.

A first rotary eye plate 17 and a second rotary eye plate 18 are attached to the stand 12 and the stand 13, respectively, via bearings 19.20.
It is rotatably supported.

The second rotary eye plate 18 is composed of a eye plate main body 21 fitted to the inner periphery of the bearing 20 and a cylindrical fitting body 22 fitted and fixed to the inner periphery of the eye plate main body 21.

The stand 14 has a first rotary eye plate 17 and a second rotary eye plate 1.
The optical fiber 3 that has been guided through the guide holes 17a and 18a of the slot rod 1 is inserted into the inverted twist groove 2 of the slot rod 1.
A rotary rod 23 for storing the inside is rotatably supported via a bearing 24.

This rotary twisting die 23 includes an annular body 25 attached to the inner periphery of a bearing 24 and a cylindrical fitting body 26 on the inner periphery side.

The distance N between the second rotary eye plate 18 and the rotary twisting die 23 is
It is equal to twice the reverse twist pitch P in FIG. 1(1). That is,
Set N=2P.

As shown in FIG. 7, the fitting body 22, 26 is composed of a cylindrical portion 27 having a radial threaded hole, and a screw 28 that is screwed into the threaded hole so as to be adjustable in forward and backward directions.

The tip of the neck 2B is tapered, and the throat 1
into the reverse twist groove 2 from the radial direction. If there are eight inverted twist grooves 2 as in the specific example shown in FIG. 2, the fitting body 22
．． It is sufficient that each of the lines 26 in 26 has at least one line, but preferably two lines arranged diagonally in view of manufacturing stability.

In this way, the guide projections projecting in the inner radial direction are formed on the rotary eye plate 18 and the rotary twisting die 23 at equal intervals on the circumference by the screws 28 .

On the upstream side of the annular body 25 of the rotary twisting die 23, an eighth
A depressed portion 29 illustrated in the figure is installed. That is, a toric body 41 is attached to the toric body 41 so as to be rotatable relative to the annular body 25 through a mounting member and a bearing (not shown in detail), and a radial protruding body 42 is attached to the toric body 41 so that the position can be freely adjusted in the radial direction.・
will be established. The tips of the protrusions 42 fit into the inverted twist grooves 2 of the slot rod l, and the inverted twist grooves 2...
The toric body 41 rotates to follow the torsion. A guide hole 43 through which the optical fiber 3 is inserted and guided is provided near the tip of the protrusion 42 . In addition, as a mechanism for adjusting the protrusion length in the radial direction of the protrusion 42, a long hole and a fixing screw are used in the case of rotation. Note that a taping head is provided near this rotary twisting die 23 (not shown). omitted), second
The presser winding 6 shown in the figure is performed.

From the above description, it can be seen that the second rotating eye plate 18 and the drop-in portion 29
It becomes clear that the rotating twisting die 23 is tuned to the twisting of the reverse twisting groove 2 of the slotted rod l.

That is, corresponding to each position of the S-Z type reverse twist groove 2..., the second rotary eye plate 18, the drop-in part 29, and the rotary twist die 23 rotate synchronously alternately on the left and right, and this rotation The speed is relatively high, and left/right flips are frequent.

However, as described in FIG. 1(1) and FIG. Reversal point A of twist groove 2,,
Since the shortest connecting imaginary line 4 connecting A, . It is in the point of doing.

In this way, the first rotating eye plate 17 rotates at a sufficiently low speed.

Moreover, since this virtual #s4 is also reversed in the S-Z shape as shown in FIG. 5, the first rotary plate 17 itself is naturally reversed in a long period in the left and right directions. The slow rotation control of the first rotating eye plate 17 can be controlled electrically or mechanically.

Since the shape of the reversing twisting grooves 2 is set so that the virtual line 4 is alternately reversed left and right, the supply device having the supply bobbin outside the left view of FIG. 6 is connected to the slot rod. There is no longer a need to rotate the take-up and take-up device outside the right side of Figure 6 around the slot rod L, and a special or complicated rotation mechanism is no longer required. , which has the advantage of being omissible.

[Effects of the Invention] The optical fiber cable according to the present invention provides good optical fiber transmission loss when wound around a drum or the like.

Furthermore, even in this drum winding state, each inverted twist groove 2
The amount of strain of the optical fibers 3 in ... becomes the same. The amount of distortion is sufficiently small, and the optical fiber can be stored wrapped around a drum or the like for a long period of time without deterioration in strength or reliability of the optical fiber. Furthermore, manufacturing is facilitated (because the twisting direction of the spiral virtual line 4 is reversed every predetermined length).

According to the manufacturing apparatus according to the present invention, a means for manufacturing the above-mentioned excellent optical fiber cable at low cost is provided. In particular, by adding the first rotary eye plate 17, the reverse twist groove 2.
The shortest connecting virtual line 4 connecting the reversal points A, A2, ... along the surface of the slot rod 1 preferably connects the optical fiber 3 to a spiral shape in which the twist direction is reversed every predetermined length. It is possible to supply while following... Moreover, the optical fiber supply device including the supply bobbin and the like can be fixed, and the equipment can be simplified and reduced.

[Brief explanation of the drawing]

Fig. 1 is a simplified plan view for comparing and explaining the present invention and a conventional example, Fig. 2 is a cross-sectional view of an example of an optical fiber cable, Fig. 3 is a cross-sectional view for explaining the dimensional relationship, and Fig. 4 is a diagram of the present invention. FIG. 5 is an explanatory diagram of the essential parts of the present invention, and FIG. 6 is an embodiment of the manufacturing apparatus of the present invention. FIG. 7 is a cross-sectional view of the fitted body, and FIG. 8 is a front view of the main part of the depressed portion. l...Slotted rod, 1a...Surface, 2...Reverse twisted groove, 4...Shortest connecting virtual line, 15...Fixed eye plate, 17...First rotating eye plate, 18. ...Second rotary plate,
23...Rotating twist die.

Claims (1)

[Claims] 1. In an optical fiber cable in which an optical fiber is housed in the reverse twist groove of a slot rod having at least one reverse twist groove, the reverse points of each of the above reverse twist grooves are aligned. Along the surface of the above slotted rod, tied with a skip,
An optical fiber cable characterized in that the shape of the reversal twist groove is set so that the shortest connecting virtual line draws a gentle spiral shape in which the twist direction is reversed every predetermined length. 2. At least one inverted twist groove is recessed on the surface, and the shortest connecting imaginary line along the surface, which connects the inverted points of each of the inverted twist grooves at every predetermined length, A slot rod characterized in that the shape of the reversal twist groove is set so as to draw a gentle spiral shape in which the twist direction is reversed. 3. An apparatus for manufacturing an optical fiber cable comprising a slot rod having at least one reverse twist groove and an optical fiber housed in the reverse twist groove of the slot rod, the cable being fed in the longitudinal direction. A fixed eye plate, a first rotary eye plate, and a second rotary eye plate for guiding the plurality of optical fibers are sequentially arranged from upstream to downstream around the slot rod, and the second rotary eye plate guides the plurality of optical fibers. The first rotating plate rotates in phase synchronization with the rotary twisting die downstream of the plate.
A cable manufacturing device characterized in that a rotating eye plate is configured to rotate at a sufficiently low speed.