JP2003054982A - Method for winding up optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for winding up optical fiber by which the loss increase due to winding loosening in a first layer or in the vicinity thereof can be suppressed. SOLUTION: The optical fiber f is wound up on an outer periphery of a drum of a bobbin 16 via a guide pulley 11, a first dancer roller 12, a second dancer roller 13, a roller 14 and a winding up guide pulley 15 in turn. Load F given to the first dancer roller 12 and the second dancer roller 13 is adjusted and thereby winding tension at the time of winding the optical fiber f on the outer periphery of the drum of the bobbin 16 is adjusted. The load F at the time of respectively winding the first layer and the second layer is controlled so that winding tension T1 at the time of winding the first layer of the optical fiber f and winding tension T2 at the time of winding the second layer thereof satisfy a relation: T1 =(1+a1 )T2 and 0.05<a1 <0.25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber winding method for winding an optical fiber around the outer circumference of a bobbin barrel.

[0002]

2. Description of the Related Art An optical fiber is manufactured by drawing an optical fiber preform and wound on a bobbin after the drawing. The bobbin barrel is generally made of metal (for example, aluminum alloy) or plastic and has a cylindrical shape and is rigid. Therefore, if the optical fiber is wound directly around the outer circumference of the bobbin barrel, the unevenness on the surface of the bobbin barrel causes the optical fiber to be compressed or slightly bent, resulting in microbend loss of the optical fiber. Will end up. Also, if there is a scratch on the surface of the bobbin body,
The coating of the optical fiber may be damaged and the fiber strength may be reduced. In order to deal with such a problem, a side pressure buffering member that absorbs pressure due to winding is wound around the outer circumference of the bobbin barrel, and an optical fiber is wound around the outer side of this side pressure buffering member, so that microbend loss is lost. It has been attempted to suppress the occurrence of the above-mentioned phenomenon and the decrease of the fiber strength.

[0003]

Conventionally, the winding tension was kept constant when the optical fiber was wound around such a bobbin. However, the present inventor has found that the following problems occur when the winding tension is constant.

That is, as shown in FIG. 4, the relationship between the pressure and the compressibility of the polyethylene-based foamed resin used as the lateral pressure buffer member is such that when the pressure is small, the change in contraction amount with respect to the pressure change is large and the pressure is large. The change in the contraction amount with respect to the change in pressure becomes smaller as it becomes smaller. The higher the compression rate, the greater the compression strength increase amount relative to the compression rate increase amount. To obtain the same amount of compression, 2.5 times more pressure is required when compressing from 25% to 50% than when compressing from 0% to 25%. 9 when compressing from 50% to 75%
Double pressure is required. In this way, the lateral pressure cushioning member
The larger the pressure, the smaller the increase in contraction amount with respect to the increase in pressure.

On the other hand, when the optical fiber is wound around the bobbin with a constant winding tension, as the number of winding layers increases, the pressure applied to the side pressure buffering member increases due to the tightening, and the amount of contraction of the side pressure buffering member increases. Will increase. When the contraction amount of the lateral pressure buffer member increases, the optical fiber becomes loose in the lower layer such as the first layer at the beginning of winding the optical fiber.
The amount of looseness differs depending on various conditions such as the Young's modulus and thickness of the lateral pressure buffer member, the winding tension when the optical fiber is wound around the bobbin barrel, and the spacing in each layer of the optical fiber.

Depending on these conditions, the optical fiber in the lower layer may be loosened as it rises from the gap between the optical fibers in the upper layer. When the optical fiber near the first layer is loosened in this manner, the optical fiber near the first layer is bent by a small radius of curvature due to compression by the optical fiber wound on the optical fiber. The loss increases due to. Then, if the loss of the optical fiber increases due to this bending, the transmission loss of the optical fiber cannot be accurately measured, and therefore, the step of rewinding the optical fiber becomes necessary, and the work efficiency decreases.

In order to solve such a problem, it is conceivable to decrease the foaming rate of the lateral pressure buffer member to increase the hardness, or to reduce the lateral pressure buffer member to reduce the amount of shrinkage. However, in this case, the unevenness of the surface causes the optical fiber to be pressed or slightly bent, which causes microbend loss of the optical fiber, which is contrary to the purpose of providing the lateral pressure buffer member. Become.

The present invention has been made to solve the above problems and provides an optical fiber winding method capable of suppressing an increase in loss due to loosening of the winding in the first layer or its vicinity. With the goal.

[0009]

An optical fiber winding method according to the present invention is a method of winding an optical fiber around the outer circumference of a bobbin barrel, in which the nth layer (n) of the optical fiber is wound around the outer circumference of the bobbin barrel.
Is an integer greater than or _equal to 1) and the winding tension when winding the first layer of the optical fiber is T ₁
And the winding tension T ₂ when winding the second layer satisfy the relational expression: T ₁ = (1 + a ₁ ) T ₂ 0.05 <a ₁ <0.25. This suppresses the occurrence of loosening of the first layer of the optical fiber, and suppresses an increase in loss due to bending.

In the optical fiber winding method according to the present invention, the winding tension T ₂ when winding the second layer of the optical fiber and the winding tension T ₃ when winding the third layer are T ₂ = (1 + a ₂ ) T ₃ 0 ≦ a ₂ <0.25, and the winding tension T ₃ when winding the third layer of the optical fiber and the winding tension T ₄ when winding the fourth layer are T ₃ = It is preferable that the relational expression (1 + a ₃ ) T ₄₀ ≦ a ₃ <0.25 is satisfied. In this case, the occurrence of looseness in the vicinity of the first layer of the optical fiber is suppressed, and the increase in loss due to bending is suppressed.

In the optical fiber winding method according to the present invention, the winding tension T ₁ when winding the first layer of the optical fiber is 686 mN.
It is preferably (70 g) or less, and the winding tension when winding the fourth and subsequent layers of the optical fiber is preferably 392 mN (40 g) or more. In this case, the occurrence of looseness of the optical fiber is suppressed when the winding tension setting value of each layer is changed.

In the optical fiber winding method according to the present invention, it is preferable that a lateral pressure buffer member is provided on the outer periphery of the bobbin body and the optical fiber is wound around the lateral pressure buffer member. In this case, when the first layer is wound, the lateral pressure cushioning member shrinks sufficiently,
The contraction of the lateral pressure cushioning member is small during the winding of the second and subsequent layers. This suppresses the occurrence of loosening of the first layer of the optical fiber, and suppresses an increase in loss due to bending.

In the optical fiber winding method according to the present invention, the winding tension at the time of winding the optical fiber is adjusted by adjusting the load of the dancer roller provided on the traveling path of the optical fiber reaching the bobbin. Is preferred. Also, set the winding layer when winding the optical fiber around the bobbin barrel,
It is preferable to adjust the winding tension when winding the optical fiber based on the information of the set winding layer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 is a block diagram of an optical fiber winding device. The optical fiber winding device 1 shown in this figure is provided at a subsequent stage or the like of a drawing device for drawing an optical fiber preform to manufacture an optical fiber f.
The first dancer roller 12, the second dancer roller 13, the roller 14, the winding guide pulley 15, the bobbin 16, the fixed portion 17, the movable portion 18, the first sensor 21, the second sensor 22 and the control portion 23 are provided.

In this optical fiber winding device 1, the optical fiber f includes a guide pulley 11 and a first dancer roller 1.
2, the second dancer roller 13, the roller 14, and the winding guide pulley 15 in this order, and the winding is performed on the outer circumference of the body of the bobbin 16. The weights of the first dancer roller 12 and the second dancer roller 13 placed on the first dancer roller 12 and the second dancer roller 13 can be adjusted, or the rotation torque can be adjusted. Accordingly, the load F applied to the first dancer roller 12 and the second dancer roller 13 is adjusted, and the winding tension when the optical fiber f is wound around the outer circumference of the bobbin 16 barrel is adjusted. A lateral pressure buffer member is provided on the outer periphery of the body of the bobbin 16, and the optical fiber f is wound around the lateral pressure buffer member.

The winding guide pulley 15 is supported by a movable portion 18 capable of reciprocating traverse with respect to the fixed portion 17, and by this reciprocating traverse, the optical fiber f is wound over the entire length of the bobbin 16 in the longitudinal direction of the barrel. Let it take. First
The sensor 21 detects that the take-up guide pulley 15 has reached one end side during the reciprocal traverse.
The sensor 22 detects that the winding guide pulley 15 has reached the other end side during reciprocal traverse. The control unit 23 receives the detection results of the first sensor 21 and the second sensor 22, respectively, and recognizes, based on the detection results, what layer of the optical fiber f is wound around the barrel of the bobbin 16. In addition, the load F applied to the first dancer roller 12 and the second dancer roller 13 is controlled based on the recognition result. Thus, the winding tension when the optical fiber f is wound is adjusted based on the information of the winding layer when the optical fiber f is wound around the outer circumference of the bobbin 16.

In this embodiment, when the winding tension when winding the n-th layer (n is an integer of 1 or more) of the optical fiber f around the outer circumference of the barrel of the bobbin 16 is expressed as T _n , each winding tension is The load F applied to the first dancer roller 12 and the second dancer roller 13 so that T _n satisfies the following relationship.
Is controlled. FIG. 2 is an explanatory diagram of the optical fiber winding method according to the present embodiment.

As shown in this figure, the winding tension T ₁ when winding the first layer of the optical fiber f is higher than the winding tension T ₂ when winding the second layer so that the winding tension T ₁ is higher than that of the first layer. The load F when winding each of the two layers is controlled. Preferably, the winding tension T when winding the first layer of the optical fiber f
₁ and the second layer so that the winding tension T ₂ when winding the second layer satisfies the relational expression T ₁ = (1 + a ₁ ) T ₂ 0.05 <a ₁ <0.25. The load F when winding each layer is controlled.

[0020] By winding tension T ₁ of the thus first layer is larger than the winding tension T ₂ of the second layer, side pressure-absorbing member during the winding of the first layer is sufficiently deflated, the second layer and subsequent winding At the time of taking, the contraction of the lateral pressure cushioning member becomes small. This allows
The occurrence of loosening of the first layer of the optical fiber f is suppressed, and an increase in loss due to bending is suppressed. Furthermore, this allows the transmission loss of the optical fiber f to be accurately measured, the frequency of the process of rewinding the optical fiber f to be reduced, and the work efficiency to be improved.

Further, the winding tension T ₂ when winding the second layer of the optical fiber f and the winding tension T ₃ when winding the third layer are as follows: T ₂ = (1 + a ₂ ) T ₃ 0≤a ₂ < It is preferable that the load F when winding each of the second layer and the third layer is controlled so as to satisfy the relational expression of 0.25. Furthermore, the winding tension T ₃ when winding the third layer of the optical fiber f and the winding tension T ₄ when winding the fourth layer are as follows: T ₃ = (1 + a ₃ ) T ₄ 0 ≦ a ₃ <0 It is preferable that the load F when winding each of the third layer and the fourth layer is controlled so as to satisfy the relational expression of 0.25.

By doing so, the lateral pressure buffering member is sufficiently contracted when winding the vicinity of the first layer, and the contraction of the lateral pressure buffering member is small when winding the layer above the first layer. This suppresses the occurrence of looseness in the vicinity of the first layer of the optical fiber f, and suppresses an increase in loss due to bending. Furthermore, this allows the transmission loss of the optical fiber f to be accurately measured, the frequency of the process of rewinding the optical fiber f to be reduced, and the work efficiency to be improved.

If the set value of the winding tension T ₁ of the first layer is too large and the difference between the winding tensions of the layers is too large, the traverse direction of the winding guide pulley 15 is reversed so that the next winding layer is rotated. There is a possibility that the optical fiber f may be loosened when the winding tension set value is changed when shifting to the winding layer. In order to suppress the occurrence of the looseness of the optical fiber f when changing the winding tension set value, the coefficient a ₁ to
Each a ₃ is preferably 0.15 or less,
More preferably, it is 0.10 or less. The winding tension T ₁ when winding the first layer of the optical fiber f is 686 mN.
(70 g) or less is preferable, and the winding tension when winding the fourth and subsequent layers of the optical fiber f is 392 mN.
It is preferably (40 g) or more.

Next, the optical fiber winding method according to the present embodiment.
An example of the method will be described. FIG. 3 shows examples and ratios.
Incompatibility when each optical fiber winding method is used
It is a figure which shows a rating. In the first embodiment, the optical fiber f
Winding tension T when winding one layer ₁To 588 mN (60 g)
And the winding tension when winding the second and subsequent layers is 490 mN.
(50 g). In the second embodiment, the first optical fiber f
Winding tension T when winding layers₁To 637 mN (65 g)
And the winding tension T when winding the second layer₂To 539 mN (5
5g) and the winding tension when winding the third and subsequent layers is 490
It was set to mN (50 g). In the comparative example, each of the optical fibers f
The winding tension when winding the layer is 490mN (50g)
It was fixed. The reject rate was wound up on bobbin 16
The loss near the lowermost layer of the optical fiber f exceeds the standard value,
It is the rate at which it is determined that rewinding is necessary.

As can be seen from FIG. 3, the rejection rate was about 11% in the comparative example, whereas the rejection rate was about 4% in Example 1, and the rejection rate was in Example 2. Is 2%
It was about. Compared with the comparative example in which the winding tension was constant, the winding tension of the first layer was 10% higher than that of the second and subsequent layers.
In Example 1, which was larger by g, the rejection rate was reduced to less than half. Further, in Example 2, as compared with Example 1, the winding tension of the first layer is larger than that of the second layer by 10 g and the winding tension of the second layer is larger than that of the third and subsequent layers by 10 g. The rejection rate has been cut in half.

[0026]

As described above in detail, according to the present invention, the winding tension when winding the n-th layer (n is an integer of 1 or more) of the optical fiber around the outer circumference of the bobbin barrel is _expressed as T _n. Winding tension T when winding the first layer of the optical fiber
₁ is larger than the winding tension T ₂ when winding the second layer, and satisfies the relational expression T ₁ = (1 + a ₁ ) T ₂ 0.05 <a ₁ <0.25. This suppresses the occurrence of loosening of the first layer of the optical fiber, and suppresses an increase in loss due to bending.

Further, preferably, the winding tension T ₂ when winding the second layer of the optical fiber and the winding tension T ₃ when winding the third layer are T ₂ = (1 + a ₂ ) T ₃ 0 ≦ a ₂ <0.25, and the winding tension T ₃ when winding the third layer of the optical fiber and the winding tension T ₄ when winding the fourth layer of the optical fiber.
And satisfy the relational expression T ₃ = (1 + a ₃ ) T ₄₀ ≦ a ₃ <0.25. In this case, the first optical fiber
The occurrence of loosening near the layers is suppressed, and the increase in loss due to bending is suppressed.

By setting the winding tension when winding each layer of the optical fiber in this way, the transmission loss of the optical fiber can be accurately measured, and the frequency of rewinding the optical fiber can be reduced. Work efficiency is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical fiber winding device.

FIG. 2 is an explanatory diagram of an optical fiber winding method according to the present embodiment.

FIG. 3 is a diagram showing a rejection rate when the optical fiber winding methods of Examples and Comparative Examples are performed.

FIG. 4 is a diagram showing a relationship between pressure and compressibility in a polyethylene-based foamed resin used as a lateral pressure buffer member.

[Explanation of symbols]

1 ... Optical fiber winding device, 11 ... Guide pulley, 12 ...
First dancer roller, 13 ... Second dancer roller, 14
... Roller, 15 ... Winding guide pulley, 16 ... Bobbin, 1
7 ... Fixed part, 18 ... Movable part, 21 ... First sensor, 22 ...
2nd sensor, 23 ... Control part.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 6/00 336 G02B 6/00 336

Claims (6)

[Claims] 1. A method of winding an optical fiber around the outer circumference of a bobbin barrel, wherein a winding tension when winding the n-th layer (n is an integer of 1 or more) of the optical fiber around the outer circumference of the bobbin barrel is T
When represented as _n , the winding tension T ₁ when winding the first layer of the optical fiber and the winding tension T ₂ when winding the second layer are T ₁ = (1 + a ₁ ) T ₂ 0.05 An optical fiber winding method, wherein the relational expression <a ₁ <0.25 is satisfied. 2. The winding tension T ₂ when winding the second layer of the optical fiber and the winding tension T ₃ when winding the third layer are T ₂ = (1 + a ₂ ) T ₃ 0 ≦ a ₂ < And the winding tension T ₃ when winding the third layer of the optical fiber and the winding tension T ₄ when winding the fourth layer of the optical fiber are: T ₃ = (1 + a ₃ ) T ₄₀ The optical fiber winding method according to claim 1, wherein the relational expression ≦ a ₃ <0.25 is satisfied. 3. The winding tension T ₁ when winding the first layer of the optical fiber is 686 mN or less, and the winding tension T when winding the fourth layer or later of the optical fiber is 392 mN or more. The optical fiber winding method according to claim 1. 4. The method of winding an optical fiber according to claim 1, wherein a lateral pressure buffering member is provided on the outer circumference of the body of the bobbin, and the optical fiber is wound around the lateral pressure buffering member. 5. The winding tension when winding the optical fiber is adjusted by adjusting the load of a dancer roller provided on the traveling path of the optical fiber reaching the bobbin. 1. The optical fiber winding method described in 1. 6. A winding layer for winding the optical fiber is set on the outer circumference of the body of the bobbin, and a winding tension for winding the optical fiber is adjusted based on information of the set winding layer. The optical fiber winding method according to claim 1, wherein: