JP2014210647A - Optical fiber wound around reel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber wound around a reel in which slip of a cushion sheet layer relative to a winding barrel is certainly and stably prevented, the optical fiber being wound around a cushion sheet layer formed on an outer periphery of the winding barrel of the reel.SOLUTION: One or more projection parts 13 projecting outward in a radial direction are formed on an outer periphery face of a winding barrel 3, an elastically compressively deformable cushion sheet layer 9 is formed on the outer periphery face of the winding barrel 3 so as to cover the projection parts, an optical fiber is wound around an outer periphery face thereof to form an optical fiber winding layer 11, the cushion sheet layer is elastically compressively deformed in the radial direction by compressive stress in the radial direction of the winding barrel, thereby, the cushion sheet layer bites into the projection parts, and at least a part of the cushion sheet layer contacts with the outer periphery face except the projection parts of the winding barrel in a state of being pressed.

Description

  The present invention relates to an optical fiber wound around a reel, that is, a reel-wound optical fiber including a reel and an optical fiber wound around the reel.

  Shipping optical fiber such as an optical fiber obtained by coating a protective coating layer on a bare optical fiber, or an optical fiber core wire in which one or more of the optical fiber is further coated, Alternatively, when an optical fiber as an intermediate product is provided to the next process during the optical fiber manufacturing process, the optical fiber is usually shipped or provided to the next process in a state of being wound around a reel (bobbin). A state in which the optical fiber (elementary wire or core) is wound around the reel in this way is called a reel-wound optical fiber. Here, as the reel, it is common to use a relatively hard resin such as ABS resin (acrylonitrile butadiene styrene copolymer resin), and when winding an optical fiber on the reel, In order to allow the optical fiber to be wound in an intimate contact state without being lifted up, it is usual to wind it while applying tension to the optical fiber.

  By the way, when an optical fiber is directly wound on a reel drum made of ABS resin or the like while applying tension to the optical fiber, unevenness on the surface of the reel (such as a step at a dividing position in the case of a reel having a divided structure) There is a possibility that the transmission characteristic of the optical fiber changes due to bending stress acting on the optical fiber locally or side pressure acting on the optical fiber. Therefore, if the transmission characteristics of the optical fiber are measured with the optical fiber wound around the reel, the transmission characteristics of the optical fiber in a straight state (when using a general optical fiber) that has been unwound are different. There is a risk that.

  Therefore, conventionally, as shown in Patent Document 1, for example, a sheet having a cushioning property of a soft foamed resin, for example, foamed polyethylene or rubber, on the outer peripheral surface of a reel made of a relatively hard resin such as an ABS resin. A (cushion sheet) is wound, and an optical fiber is wound around the outer peripheral surface of the sheet to form a reel-wound optical fiber. In such a reel-wound optical fiber, the optical fiber is not affected by the irregularities on the outer peripheral surface of the reel of the reel, and the side pressure of the optical fiber taken up by the cushioning property of the cushion sheet can be reduced. Yes. If the optical fiber is wound on the cushion sheet, the optical fiber is less likely to collapse when the reel-wrapped optical fiber is transported or handled.

However, in a reel-wound optical fiber in which a cushion sheet is wound on the outer peripheral surface of a reel winding drum and an optical fiber is wound on the cushion sheet, the reel is rotated when the optical fiber is further wound or when the optical fiber is unwound. In some cases, the cushion sheet may slip around the winding drum. In recent years, the cushion sheet has become particularly popular due to the increased winding and unwinding speeds and increased optical fiber winding amount per reel in order to improve productivity and work efficiency. Sliding is becoming more likely to occur.
That is, the cushion sheet may slip when the optical fiber is wound or unwound, but it is easy to slip particularly when a large force is applied by rapid acceleration / deceleration. For example, in the winding in the screening test for an optical fiber, the reel is suddenly stopped when the optical fiber is disconnected, and slipping is particularly likely to occur. In some cases, reel rotation is suddenly stopped due to device troubles during feeding or winding. Also, if the amount of winding is large, the moment of inertia of the entire reel on which the optical fiber is wound increases, and therefore it becomes easy to slip.

The sliding of the cushion sheet with respect to the outer peripheral surface of the reel drum as described above may cause the following problems A to E.
A: The fixed terminal at the start of winding is pulled with a large tension, and the optical fiber at the terminal is disconnected.
B: The optical fiber of the lower winding layer (the optical fiber winding layer close to the cushion sheet) is entangled, and disconnection or the like occurs at the time of feeding.
C: Rolling out occurs.
D: The cushion sheet is distorted and an uneven lateral pressure is applied to the optical fiber, and the transmission characteristics of the optical fiber cannot be accurately measured in the reel-wrapped optical fiber state.
E: The weight balance of the reel is lost, and a large vibration is generated at the time of feeding.
Therefore, when the cushion sheet is wound around the reel drum, it is strongly desired to prevent the cushion sheet from slipping with respect to the reel.

  Therefore, in Patent Document 2, in order to prevent the cushion layer corresponding to the above-described cushion sheet from slipping with respect to the winding drum of the reel, the cushion layer is preferably fixed to the outer peripheral surface of the winding drum with an adhesive. Has been proposed.

Japanese Examined Patent Publication No. 60-41323 Japanese Patent Laid-Open No. 9-258038

However, as proposed in Patent Document 2, when the cushion sheet is fixed to the reel drum with an adhesive, slipping may occur if the application of the adhesive is insufficient in the bonding process. There is a problem that lacks certainty in preventing slippage. Moreover, there is also a problem that the anti-slip effect decreases with time due to deterioration of the adhesive over time.
Furthermore, different materials must be used for reels that are required to be relatively hard and cushion sheets that are required to have cushioning properties. For example, an appropriate adhesive does not necessarily exist, and it becomes difficult to obtain a sufficient adhesive force, or an expensive adhesive must be used, resulting in an increase in cost. There is a fear. In particular, ABS resin, which is frequently used in reels for winding optical fibers, has few optimum adhesives with foams of polyolefin resins such as polyethylene and polypropylene, which are typical as cushion sheets. The fact is that there were restrictions on the application of.

  The present invention has been made against the background described above. In a reel-wound optical fiber in which a cushion sheet layer is formed on the outer peripheral surface of a reel winding drum and the optical fiber is wound thereon, the cushion sheet for the winding drum is provided. Providing a reel-wound optical fiber that can reliably and stably prevent the occurrence of layer slipping, prevent deterioration of the anti-slip effect over time, and has no restrictions on application in actual products The challenge is to do.

  As a result of repeated experiments and examinations on a technique for solving the above-described problems, in particular, a technique for preventing the occurrence of slipping of the cushion sheet layer with respect to the reel winding drum without relying on an adhesive. The cushion sheet layer is formed on the outer peripheral surface of the cushion sheet layer, the cushion sheet layer is formed on the outer peripheral surface of the cushion sheet layer, and the cushion sheet layer is formed on the outer peripheral surface of the cushion sheet layer. The cushion sheet layer is elastically compressed and deformed in the radial direction of the winding drum by applying a compressive stress in the radial direction of the winding drum, thereby causing the inner surface of the cushion sheet layer to bite into at least the tip portion of the protrusion and the cushion. It is possible to prevent slipping by contacting at least a part of the inner surface of the sheet layer while being pressed against the outer peripheral surface of the region other than the protruding portion of the winding drum. It was found to be effective in.

Therefore, the reel-wound optical fiber according to the basic aspect (first aspect) of the present invention is:
In a reel-wound optical fiber in which an optical fiber is wound around a reel winding cylinder having a cylindrical winding drum,
On the outer peripheral surface of the winding drum, at least one or more protrusions projecting outward in the radial direction of the wound copper are formed,
A cushion sheet layer made of a soft material that can be elastically compressed and deformed is formed on the outer circumferential surface of the wound copper so as to cover the protrusion, and the optical fiber is wound on the outer circumferential surface of the cushion sheet layer. An optical fiber winding layer is formed,
In addition, the cushion sheet layer is elastically compressed and deformed in the radial direction of the winding drum by the compressive stress in the radial direction of the winding drum, whereby the inner surface of the cushion sheet layer bites into at least the tip portion of the protrusion, and At least a part of the inner surface of the cushion sheet layer is in contact with the outer peripheral surface of the region other than the protruding portion in the winding drum in a pressed state.

  In such a reel-wound optical fiber according to the first aspect, the inner surface of the cushion sheet layer bites into at least the tip portion of the protruding portion protruding from the outer peripheral surface of the winding drum, so that the biting portion is a cushion sheet for the winding drum. Since the slippage of the layer is prevented and the biting is performed by elastic compression deformation in the winding drum radial direction due to the compressive stress in the winding drum radial direction, the inner surface of the cushion sheet is at least the outer surface of the projection at the tipping portion. It is in close contact with each other, and the slip of the cushion sheet layer can be surely prevented, and the biting state is less likely to be released over time. Further, at least a part of the inner surface of the cushion sheet layer comes into contact with the outer peripheral surface of the region other than the protrusions in the winding drum by elastic compression deformation in the winding drum radial direction due to the compressive stress in the winding drum radial direction. Therefore, in the contact region, the frictional resistance between the cushion sheet layer and the winding drum outer peripheral surface plays a role of preventing the cushion sheet layer from slipping. In this way, both the biting of the cushion sheet layer with respect to the protrusion and the pressing contact with the outer peripheral surface of the winding drum due to the elastic compression deformation in the winding drum radial direction due to the compressive stress in the winding drum radial direction are combined. It is possible to effectively prevent the occurrence of slipping of the cushion sheet layer against the above.

  Here, if the cushion sheet layer does not bite into the protruding portion, the cushion sheet layer is lifted by the tip of the protruding portion, and not only does the slip prevention effect due to the biting in, but also the outer periphery of the winding drum excluding the protruding portion There is also a risk that the contact area with respect to the surface becomes small, and on the contrary, it becomes slippery. However, in the case of the present invention, the slip prevention effect can be surely and stably achieved by both the biting into the protrusion and the pressing contact with the outer peripheral surface of the winding drum.

Also, here, if it is intended to prevent slipping by only biting into the protrusion, the thickness of the cushion sheet layer is reduced or the height of the protrusion is reduced in order to sufficiently secure the amount of protrusion of the protrusion against the cushion sheet layer. In that case, there is a possibility that a lateral pressure is indirectly applied from the protrusion to the optical fiber in the optical fiber winding layer outside the cushion sheet layer made of a soft material. In this case, since not only the protrusions bite but also the pressing contact with the outer peripheral surface of the winding drum is used in combination, the thickness of the cushion sheet layer is excessively decreased or the protrusions are excessively increased in height. The anti-slip effect can be exerted without having to squeeze, so even if there is a protrusion, it is avoided that a lateral pressure is applied to the optical fiber due to the protrusion. Rukoto can. Further, since the cushion sheet layer itself is made of an elastic material, the force from the optical fiber winding layer is dispersed and uniformed by its stress dispersion characteristics, and the optical fiber winding is also performed at the contact portion of the cushion sheet layer with the outer periphery of the winding drum. Since the force from the collecting layer is borne, it is possible to effectively prevent a large lateral pressure from being applied to the optical fiber locally.
Here, the cushion sheet layer is elastically compressed and deformed in the radial direction of the winding drum by the compressive stress, the inner surface of the cushion sheet layer bites into at least the tip portion of the protrusion, and at least one of the inner surfaces of the cushion sheet layer. The part is in contact with the outer peripheral surface of the region other than the protrusions in the winding cylinder in a pressed state. The optical fiber is unwound from the reel-wound optical fiber, and only one layer of the optical fiber remains on the winding cylinder. It is desirable to maintain the state up to the state.

  The reel-wound optical fiber according to the second aspect of the present invention is the reel-wound optical fiber according to the first aspect, wherein the plurality of protrusions are spaced apart in the circumferential direction of the outer peripheral surface of the winding drum as the protrusions. It is characterized by being formed.

  According to the reel-wound optical fiber of the second aspect as described above, the plurality of protrusions are formed at intervals in the circumferential direction of the outer peripheral surface of the winding drum. It can be demonstrated more reliably.

  The reel-wound optical fiber according to the third aspect of the present invention is the reel-wound optical fiber according to the first or second aspect, wherein the plurality of protrusions are parallel to the central axis of the winding drum. It is characterized by being formed at intervals in the direction.

  According to such a reel-wound optical fiber of the third aspect, since the plurality of protrusions are formed at intervals in a direction parallel to the central axis of the winding cylinder, the occurrence of slipping of the cushion sheet layer is prevented. , Can be demonstrated more reliably.

  A reel-wound optical fiber according to a fourth aspect of the present invention is the reel-wound optical fiber according to any one of the first to third aspects, wherein the compressive stress of the cushion sheet layer is a value when the optical fiber is wound. It is characterized by a take-up tension.

  Here, when winding the optical fiber to form the optical fiber winding layer on the outer peripheral surface of the cushion sheet layer, the optical fiber is wound while applying tension (so-called winding tension). The optical fiber winding layer is in a state where tensile stress is applied in the circumferential direction of the winding drum. The circumferential tensile stress of the optical fiber winding layer is applied to the inner cushion sheet layer as a force inward in the radial direction of the winding drum. Here, since the position of the inner surface of the cushion sheet layer is regulated by the outer peripheral surface of the winding drum and the protrusion, compressive stress is generated in the cushion sheet layer in the radial direction of the winding drum. Since the winding drum is made of a soft material that can be elastically compressed and deformed, the cushion sheet layer is formed by the compressive stress in the radial direction of the winding drum so that the protrusions of the winding drum and the outer peripheral surface of the winding drum as described above. It will be pushed towards.

  The reel-wound optical fiber according to the fifth aspect of the present invention is the reel-wound optical fiber according to the fourth aspect, wherein the cushion sheet layer has a compressive stress in addition to the winding tension at the time of winding the optical fiber. It is based on the cushion sheet winding tension when the sheet layer is formed on the outer peripheral surface of the winding drum.

  Here, the cushion sheet layer is usually a belt-like sheet (cushion sheet) made of a soft material that can be elastically compressed and deformed. The cushion sheet layer is wound around the outer periphery of the winding drum, but both end faces are welded or bonded together. In general, the sheet is joined by an agent or the like. In that case, when the belt-like sheet is wound on the outer periphery of the winding drum, tension is usually applied to the sheet. Therefore, the sheet is also elastically compressed and deformed in the thickness direction by the winding tension (tension in the circumferential direction of the winding drum), and a compressive stress is applied to the cushion sheet layer on the winding drum.

  Furthermore, the reel-wound optical fiber according to the sixth aspect of the present invention is the reel-wound optical fiber according to any one of the first to fifth aspects, wherein the entire area of the inner surface of the cushion sheet layer is the surface of the protrusion. And the outer peripheral surface of the winding drum other than the protrusions.

  In the reel-wound optical fiber of the present invention, basically, as described above, the inner surface of the cushion sheet layer bites into at least the tip portion of the protrusion on the winding drum, and the protrusion to the protrusion on the inner surface of the cushion sheet layer. If at least a part of the portion excluding the biting portion is in contact with the outer peripheral surface of the region other than the protrusion in the winding drum in a state of being pressed, the anti-slip effect of the cushion sheet layer can be exhibited, In particular, as described in the sixth aspect, if the entire area of the inner surface of the cushion sheet layer is in contact with either the surface of the protrusion and the outer surface of the winding drum other than the protrusion, If there is no contact area and the cushion sheet layer is entirely in contact with the winding drum side, the anti-slip effect can be exhibited more reliably and stably.

On the other hand, the reel-wound optical fiber according to the seventh aspect of the present invention is the reel-wound optical fiber according to any one of the first to fifth aspects,
The inner surface of the cushion sheet layer is in contact with the outer peripheral surface of the winding drum and the surface of the protruding portion between a portion that bites into the tip of the protruding portion and a region that is in contact with the outer peripheral surface of the winding drum other than the protruding portion. There is a non-contact area, and the cushion sheet layer inner surface of the non-contact area has a shape that is convex and curved toward the rising portion of the projection from the outer peripheral surface of the winding drum It is.

In the reel-wound optical fiber of the present invention, even if the entire area of the inner surface of the cushion sheet layer is not in contact with the outer surface of the protrusion and the outer peripheral surface of the winding drum (that is, there is a non-contact area). As long as the conditions described in the first aspect are satisfied, an anti-slip effect can be achieved. For example, when a part of the inner surface of the cushion sheet layer does not contact a part of the outer surface of the protruding part (the outer surface of the base end part excluding the tip part) or a part of the outer peripheral surface of the winding cylinder that follows, that is, the base of the protruding part Even if there is a non-contact region near the end, the cushion sheet layer can be prevented from slipping.
Thus, the seventh aspect defines the case where the non-contact region exists near the base end of the protrusion. In the seventh aspect, the outer peripheral surface of the winding drum and the surface of the protruding portion are in contact between the portion biting into the tip of the protruding portion and the region in contact with the outer peripheral surface of the winding drum other than the protruding portion. When there is no non-contact area, the cushion sheet layer inner surface of the non-contact area has a curved shape toward the rising portion (base end) of the protrusion from the outer peripheral surface of the winding drum. Then, since the inner surface of the cushion sheet layer is close to the outer surface of the protrusion (particularly the outer surface near the base end) by the convex curve, the effect of preventing the cushion sheet layer from slipping by the protrusion is large. Become.

Furthermore, the reel-wound optical fiber according to the eighth aspect of the present invention is the reel-wound optical fiber according to any one of the first to seventh aspects,
The protrusion is asymmetrical in the circumferential direction of the winding drum, and the inclination angle of the outer surface on one side in the circumferential direction of the winding drum and the other side in the circumferential direction of the winding drum in at least the tip portion of the protrusion. The inclination angle of the outer surface is different.

  Here, the greater the inclination angle of the outer surface of the protrusion, the greater the effect of preventing the cushion sheet layer from slipping. However, if the inclination angle of the outer surface of the protrusion is increased as a symmetrical shape in the circumferential direction of the winding drum, the protrusion However, there is a problem that the shape becomes sharp and sharp, the strength is lowered, defects are easily generated, and durability is inferior. Therefore, in consideration of the direction in which slippage is most likely to occur during actual use, the inclination angle of the outer surface that exhibits the most effective anti-slip effect is increased with respect to the slip direction, and the outer surface on the opposite side Has a relatively small inclination angle, that is, it is asymmetrical, while ensuring an anti-slip effect, it does not have a sharply shaped protrusion, ensuring the strength of the protrusion and improving durability Can be.

Furthermore, the reel-wound optical fiber according to the ninth aspect of the present invention is the reel-wound optical fiber according to the eighth aspect,
A plurality of protrusions are formed as the protrusions, and among the plurality of protrusions, at least one of the protrusions is an outer surface on one side in the circumferential direction of the winding drum at least at the tip portion. The inclination angle of the outer surface on the other side is larger than the inclination angle of the outer surface of the other side, and the other one or more protrusions have an inclination angle of the outer surface on the one side in the circumferential direction of the winding drum at least at the tip portion. It is smaller than the inclination angle of the outer surface on the side.

In such a reel-wound optical fiber of the ninth aspect, as shown in the eighth aspect, protrusions that are asymmetric in the circumferential direction of the winding drum are dispersed and mixed in different directions in the circumferential direction of the winding drum. Therefore, the effect of preventing the cushion sheet layer from slipping can be surely and stably obtained regardless of the winding direction, the feeding direction, acceleration, and deceleration.
In other words, when using an actual reel-wound optical fiber, the direction of winding and unwinding may vary depending on the winder and unwinder in the optical fiber manufacturing process, etc., and an empty reel can be used as a winder or unwinder. Usually, it varies depending on the mounting direction when mounting. Moreover, even if the direction of winding and the direction of feeding are constant, the direction of slipping of the cushion sheet layer is reversed during acceleration and deceleration. However, if a plurality of asymmetric protrusions are dispersed and mixed in different directions in the circumferential direction of the winding drum, no matter which direction the slip occurs, any of the outer surfaces of the plurality of protrusions It is possible to reliably prevent the occurrence of slipping of the cushion sheet layer by any one of the outer surfaces having a large inclination angle.

Furthermore, the reel-wound optical fiber according to the tenth aspect of the present invention is the reel-wound optical fiber according to any one of the first to ninth aspects,
In the region of the inner surface of the cushion sheet layer that is in contact with the outer peripheral surface of the winding drum, the cushion sheet layer is bonded to the outer peripheral surface of the winding drum with an adhesive or an adhesive.

In the reel-wound optical fiber of the present invention, basically, as already described, the cushion sheet layer bites into the protrusions due to the elastic compression deformation in the winding drum radial direction due to the compressive stress in the winding drum radial direction, and the winding. Combined with the pressing contact (friction resistance) with the outer peripheral surface of the cylinder, it is possible to effectively prevent the cushion sheet layer from slipping with respect to the winding cylinder. However, as defined in the tenth aspect, In particular, if an adhesive or a pressure-sensitive adhesive is used, the occurrence of slipping of the cushion sheet layer can be prevented more reliably.
Here, even if the bonding force by the adhesive or the adhesive material is not sufficient, the effect of preventing the occurrence of slipping is not sufficient due to the biting into the protrusion and the frictional resistance against the outer periphery of the winding drum. Can be avoided. Therefore, the range of selection of the adhesive or the pressure-sensitive adhesive material is much wider than that proposed in Patent Document 2.

Furthermore, the reel-wound optical fiber according to the eleventh aspect of the present invention is the reel-wound optical fiber according to any one of the first to tenth aspects,
In an arbitrary cross section orthogonal to the rotation axis of the winding drum, even if the compressive strain in the region of the cushion sheet layer that is in contact with the outer peripheral surface of the winding drum is the lowest guaranteed environmental temperature during transportation and use An optical fiber winding layer is formed by winding an optical fiber on the cushion sheet layer with a tension that is greater than zero.

  The material of the reel often has a positive coefficient of thermal expansion.In that case, in a low temperature use environment, the reel is thermally contracted, and the pressing force from the optical fiber winding layer to the winding drum is reduced. Slip occurs between the cushion sheet layer and the optical fiber take-up layer, or the roll is easily collapsed. However, in the reel-wound optical fiber according to the eleventh aspect, since the tension of the optical fiber is maintained by the residual stress even in a low-temperature use environment, it is possible to prevent slippage from being easily generated or collapsed. be able to.

Furthermore, the reel-wound optical fiber according to the twelfth aspect of the present invention is the reel-wound optical fiber according to any one of the first to eleventh aspects,
The cushion sheet when the optical fiber loss begins to increase when the maximum compressive strain amount of the region of the cushion sheet layer that is bitten by the protrusion is wound on a reel having the same shape and the same dimension without the protrusion. The height of the protrusion and the winding tension are adjusted so that the amount of strain does not exceed the amount of compressive strain of the layer.

  If the optical fiber is wound too tightly when winding the optical fiber, the loss of light transmitted through the optical fiber increases. This only increases the loss temporarily, and the transmission loss of the optical fiber after unwinding returns to the original small value, but there is a problem in the measurement in the state of the reel-wound optical fiber. Therefore, in the twelfth aspect, the optical fiber loss increases when the maximum amount of compressive strain of the cushion sheet layer in the region biting into the protrusion is wound on a reel having the same shape and the same dimension without the protrusion. It was decided to adjust so that the amount of strain does not exceed the amount of compressive strain (loss increase limit strain amount) of the cushion sheet layer at the start. By adjusting in this way, the loss of the optical fiber in the state of being wound on the reel due to the compressive stress of the cushion sheet layer is increased, and an error in the inspection of the optical fiber in the state of the reel-winding optical fiber is increased. It can be prevented from becoming large.

  According to the present invention, in the reel-wound optical fiber in which the cushion sheet layer is formed on the outer peripheral surface of the reel winding drum and the optical fiber is wound thereon, the cushion sheet layer slips with respect to the reel winding drum. It can be reliably and stably prevented, and the effect of preventing slipping with time does not occur, and there is an effect that there is no restriction in application to an actual product.

It is a partial notch perspective view which shows the whole reel winding optical fiber of one Embodiment of this invention. It is a side view which shows an example of the reel used for the reel wound optical fiber shown by FIG. FIG. 3 is a longitudinal front view of a reel taken along line III-III in FIG. 2. FIG. 2 is a longitudinal front view of the reel-wrapped optical fiber shown in FIG. 1. It is a vertical front view which expands and shows the principal part of FIG. It is a vertical front view which expands and shows the principal part of the reel winding optical fiber of another embodiment of this invention. It is a vertical front view which expands and shows the principal part of the reel winding optical fiber of another embodiment of this invention. It is a side view which shows another example of the reel used for the reel winding optical fiber of this invention. It is a side view which shows another example of the reel used for the reel winding optical fiber of this invention. It is a vertical front view which expands and shows the principal part of the reel winding optical fiber of another embodiment of this invention. It is a vertical front view which expands and shows the principal part of the reel wound optical fiber of another embodiment using the protrusion part shown by FIG. It is typical front sectional drawing which shows the various examples of the projection part on the winding drum of the reel used for the reel winding optical fiber of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 shows the overall configuration of a reel-wound optical fiber 1 according to an embodiment of the present invention. FIGS. 2 and 3 show a reel 7 used in the reel-wound optical fiber 1 according to the embodiment. 4 shows a cross section of the reel-wound optical fiber 1 of the embodiment, and FIG. 5 shows an enlarged part of the cross section of the reel-wound optical fiber 1 of the embodiment.

  1 to 5, a reel-wound optical fiber 1 includes a reel 7 having flanges 5 provided at both ends in the axial direction of a cylindrical winding drum 3, and a predetermined reel on the outer periphery of the winding drum 3 of the reel 7. The cushion sheet layer 9 is provided with a thickness, and the optical fiber winding layer 11 is formed by winding an optical fiber on the outer periphery of the cushion sheet layer 9.

  The reel 7 is only required to include a cylindrical winding drum 3 on which the optical fiber is wound on the outer periphery, and the flanges 5 provided on both sides in the axial direction. Except that the protrusion 13 is formed on the outer peripheral surface of the winding drum 3 as described in the above, it may be the same as that of a reel conventionally used for winding an optical fiber. In the present embodiment, the flange portion 5 is formed with, for example, an opening window portion 5A that is cut in a slit shape from the outer peripheral edge portion toward the inner side to the outer peripheral surface extension position of the winding drum 3. In addition, this opening window part 5A may be an independent hole shape formed at a position corresponding to the cushion sheet layer 9 instead of the slit shape.

The reel 7 may be made as a whole, or may have a multi-divided structure of two or more parts as appropriate, and a plurality of reel divisions joined together. Further, the dividing position and the joining method of the divided body in the case of the multi-divided structure are not particularly limited.
The material of the reel 7 is typically ABS resin, but other metals such as aluminum, plastics such as vinyl chloride resin, nylon, polycarbonate, and high density polyethylene can be used.

  On the outer peripheral surface of the winding drum 3 of the reel 7, one or more projecting portions 13 projecting at a height H (see FIG. 5) toward the radially outer side of the reel 7 are formed. In the present embodiment, the protrusion 13 is a rib-shaped protrusion continuously extending in a direction parallel to the rotation center axis O of the reel 7 and a plurality of rib-shaped protrusions (six in the illustrated example). The portions 13 are formed at predetermined intervals in the circumferential direction of the winding drum 3. The rib-shaped protrusion 13 is formed such that a cross section orthogonal to the rotation center axis O of the reel 7 forms a triangular shape (mountain shape). That is, the protrusion 13 protrudes in a triangular cross section toward the outer side in the radial direction of the winding drum 3. In the case of this embodiment, the triangular shape of the cross section orthogonal to the rotation center axis O of the reel 7 in the rib-shaped protrusion 13 is symmetric in the outer circumferential direction of the winding drum 3 (and hence the rotation direction of the reel 7). Thus, the isosceles triangle is used, and the inclination angles of the outer surfaces (inclined surfaces) 13A and 13B of the projection 13 are the same. The rib-like protrusion 13 has a length in the direction parallel to the rotation center axis O of the reel 7 that is the same as the width of the winding drum 3 (the distance between the pair of flanges) in this embodiment. It is formed so that it may continue from one collar part to the other collar part.

  Furthermore, a cushion sheet layer 9 is formed on the outer periphery of the winding drum 3 with a predetermined thickness T (see FIG. 5) so as to cover the rib-shaped protrusion 13. The cushion sheet layer 9 is made of a cushioning material, that is, a soft material that can be elastically compressed and deformed. Typical examples include foams of polyolefin resins such as polyethylene and polypropylene, and rubber. In addition, polyethylene, polypropylene, vinyl chloride resin, ABS resin, phenol resin, saturated polyester, unsaturated polyester, polystyrene, styrene resin, methacrylic resin, etc. Various resins such as resin, acrylic resin, nylon, urethane, isoprene resin, nitrile resin, and silicon resin, copolymers thereof, or foams obtained by adjusting the hardness and the like by foaming these resins are used. The formation method of the cushion sheet layer 9 is not particularly limited. Usually, a belt-like sheet (cushion sheet) made of the above-described material is wound around the outer periphery of the winding drum 3, and both end surfaces thereof are butted to each other. In general, the gap is joined by welding or an adhesive. Further, when the reel 7 has a split structure, the cushion sheet layer can also be formed by previously forming the above material into a hollow cylindrical shape and fitting the cushion sheet hollow cylindrical body into the winding drum 3. is there.

  Further, on the outer peripheral surface side of the cushion sheet layer 9, an optical fiber winding layer 11 formed by winding optical fibers in multiple layers is formed. Here, when the optical fiber is wound, the optical fiber is wound while applying a tension (so-called winding tension) to the optical fiber. Therefore, a tensile stress is applied to the optical fiber winding layer 11 in the circumferential direction of the winding drum 3. It is in the state that was. The circumferential tensile stress of the optical fiber winding layer 11 is applied to the cushion sheet layer 9 in contact with the inner side as a force inward in the radial direction of the winding drum 3. Here, since the position of the inner surface of the cushion sheet layer 9 is regulated by the outer peripheral surface of the winding drum 3 and the protrusion 13, a compressive stress is generated in the cushion sheet 9 in the radial direction of the winding drum 3. Since the winding drum 3 is made of a material that can be elastically compressed and deformed, such as a foam of a polyolefin resin, the cushion sheet layer 9 is projected by the compressive stress in the radial direction of the winding drum 3. It will be pressed toward the outer peripheral surface of the part 13 and the winding drum 3. And the location corresponding to the projection part 13 in the cushion sheet layer 9 will be in the state which bite into at least the front-end | tip part of the projection part 13. FIG. Here, a region of the inner surface of the cushion sheet layer 9 that bites into the protruding portion 13 and is in contact with the outer surfaces (inclined surfaces) 13A and 13B of the protruding portion 13 is referred to as a protruding portion biting region 9A. In addition, at least a part of the region other than the protrusion biting region 9A on the inner surface of the cushion sheet layer 9 is at least a part of the outer peripheral surface of the winding drum 3 (a portion of the cylindrical surface excluding the portion where the protrusion 13 is formed). In the pressed state. Here, the area | region which is contacting the winding drum outer peripheral surface in the inner surface of the cushion sheet layer 9 shall be called the winding drum outer peripheral surface contact area 9B.

  Here, in the case of the embodiment shown in FIGS. 4 and 5, the inner surface of the cushion sheet layer 9 bites into the entire protruding portion 13 (and thus touches the entire outer surface of the protruding portion 13) to the width of the protruding portion 13. A corresponding protrusion biting area 9A is formed, and all the areas excluding the protrusion biting area 9A are the winding drum outer peripheral surface contact area 9B.

  On the other hand, in FIG. 6, the cushion sheet layer 9 bites into only the tip portion of the projection 13 at a position corresponding to the projection 13 on the inner surface of the cushion sheet layer 9, and the region other than the projection bite area 9 </ b> A Of these, a state is shown in which a region away from a position spaced from the base end (rising portion) of the protrusion 13 by a small distance is a winding drum outer peripheral surface contact region 9B. In this case, in the vicinity of the base end of the protruding portion 13 (a portion between the protruding portion biting region 9A and the winding drum outer peripheral surface contact region 9B), a region that does not contact the outer surface of the protruding portion 13 and the outer peripheral surface of the winding drum 3 (non-contacting) Region) 9C exists. Even when such a non-contact region exists, the anti-slip effect according to the present invention can be exhibited.

  In the above embodiment, the cushion sheet layer 9 has its inner surface biting into at least the tip portion of the protrusion 13, and therefore the cushion sheet layer 9 is likely to slide with respect to the winding drum 3 during winding or unwinding of the optical fiber. Even in this case, the sliding is prevented by the protrusion 13.

  Specifically, for example, when the reel 7 rotates in the direction of the arrow D1 in FIGS. 5 and 6 to wind up the optical fiber, the rotation of the reel 7 is rapidly decelerated due to disconnection during the screening test. Then, the cushion sheet layer 9 tends to slip in the direction D1 relative to the winding drum 3 due to the inertial force in the direction D1, but the slip in that direction is inclined on one side of the protrusion 13. Blocked by face 13A.

  In the case where the optical fiber is drawn out from the optical fiber winding layer 11 in the direction of the arrow D1 in FIGS. 5 and 6, at the initial stage of the drawing, a tension in the direction of D2 is applied to the optical fiber, The tension of the layer 11 is applied to the cushion sheet layer 9, so that the cushion sheet layer 9 tends to slip relative to the winding drum 3 in the direction D <b> 2. It is blocked by the inclined surface 13B on the other side. In this way, slipping of the cushion sheet layer 9 is prevented by any one of the inclined surfaces 13A and 13B of the protrusion 13.

  As described above, the inner surface of the cushion sheet layer 9 bites into at least the tip portion of the protrusion 13, that is, the presence of the protrusion biting area 9A, the acceleration is performed during winding or unwinding. The cushion sheet layer 9 can be prevented from slipping with respect to the winding drum 3 at both time and deceleration.

  Moreover, in the protruding portion biting region 9A of the cushion sheet layer 9, since the compressive stress is applied to the inside of the cushion sheet layer 9, the cushion sheet layer 9 is inclined to the inclined surface 13A of the protruding portion 13 in a state where a so-called pressure is applied. Therefore, the above-described slippage prevention function can be sufficiently exhibited.

Furthermore, the winding drum outer peripheral surface contact region 9B on the inner surface of the cushion sheet layer 9 is in contact with the outer peripheral surface of the winding drum pressed by elastic compression deformation in the winding drum radial direction due to compressive stress in the winding drum radial direction. In the contact region 9B, the frictional resistance between the cushion sheet layer 9 and the outer circumferential surface of the winding drum plays a role of preventing the cushion sheet layer 9 from slipping.
Therefore, the anti-slip effect can be produced reliably and stably by both the biting into the protrusion 13 and the pressing contact with the outer peripheral surface of the winding drum.

  Here, in the case of the embodiment shown in FIGS. 4 and 5, the protruding portion biting area 9 </ b> A of the cushion sheet layer 9 bites into the entire protruding portion 13 (therefore, on the entire inclined surfaces 13 </ b> A and 13 </ b> B of the protruding portion 13). In addition, all the regions except the protruding portion biting region 9A are winding drum outer peripheral surface contact regions 9B. That is, all the areas of the inner surface of the cushion sheet layer 9 are in contact with either the outer surfaces (inclined surfaces) 13A and 13B of the protruding portion 13 and the outer peripheral surface of the winding drum other than the protruding portion 13. If there is no region and such a configuration, the anti-slip effect can be exhibited most effectively, but as shown in FIG. 6, the vicinity of the base end of the protrusion 13 (the protrusion biting region 9A and Even if there is a region (non-contact region) 9C that does not contact the outer surface of the protrusion 13 and the outer peripheral surface of the winding drum 3 at a location between the winding drum outer peripheral surface contact region 9B), an anti-slip effect can be achieved. it can.

  However, when the non-contact region 9C exists, as shown in FIG. 6, the inner surface of the cushion sheet layer in the non-contact region 9C is directed toward the base end (rising portion) of the protrusion 13 from the outer peripheral surface of the winding drum. It is desirable that the shape bend and convex. By convexly bending in this manner, the cushion sheet layer inner surface is close to the outer surface near the base end of the protrusion 13 in the non-contact region 9C, so that the anti-slip effect is greater than when the convex sheet is not bent.

  When forming the optical fiber winding layer 11 by winding the optical fiber on the cushion sheet 9 layer, the compressive strain of the winding drum outer peripheral surface contact region 9B in the cushion sheet layer 9 is orthogonal to the rotation axis of the winding drum 3. In any cross section, it is desirable to wind up the optical fiber with a tension that is greater than 0 even when the guaranteed environmental temperature during transportation and use is reached. That is, the material of the reel 7 often has a positive thermal expansion coefficient. In this case, the reel 7 is thermally contracted in a low temperature use environment, and the pressing force from the optical fiber winding layer 11 to the winding drum 3 is reduced. Becomes smaller, and slipping occurs between the cushion sheet layer 9 and the optical fiber winding layer 11 or the winding collapse easily occurs. However, if the tension at the time of winding is adjusted as described above, the tension of the optical fiber is maintained by the residual stress even in a low-temperature usage environment. Can be prevented.

  In addition, in the reel 7 shown in FIG. 1, since the opening window part 5A is formed in the collar part 5, from the opening window part 5A, the thickness and gap of the cushion sheet layer 9 can be confirmed. It is possible to confirm the state of distortion of the cushion sheet layer 9. In addition, it is possible to test in advance around a transparent bobbin having the same shape and the same size, or to check the state of distortion of the cushion sheet layer 9 using a pressure sensor.

  Furthermore, in the reel-wound optical fiber of the present invention, when the maximum compressive strain amount of the protrusion biting region 9A in the cushion sheet layer 9 is wound on a reel having the same shape and the same size without the protrusion 13, the optical fiber loss is reduced. It is desirable to adjust the height of the protrusion 13 and the winding tension so that the amount of strain does not exceed the amount of compressive strain (loss increase limit strain amount) of the cushion sheet layer 9 when it begins to increase.

If the optical fiber is wound too tightly when winding the optical fiber, the loss of light transmitted through the optical fiber increases. This only increases the loss temporarily, and the transmission loss of the optical fiber after unwinding returns to the original small value, but there is a problem in the measurement in the state of the reel-wound optical fiber. Therefore, when the maximum compressive strain amount of the cushion sheet layer 9 in the region 9A biting into the protrusion 13 is wound on a reel having the same shape and the same dimension without the protrusion 13, the optical fiber loss starts to increase. It is desirable to adjust so that the amount of distortion does not exceed the amount of compressive strain (loss increase limit strain amount) of the cushion sheet layer.
In addition, the distortion amount of the cushion sheet layer 9 can be visually confirmed from the opening window portion 5A of the flange portion 5, or may be detected by a sensor. Further, the loss increase limit strain can be known by experimentally changing the winding tension, the winding amount, etc., examining the loss increase limit, and measuring the thickness of the cushion sheet layer at that time.

Furthermore, in the winding drum outer peripheral surface contact region on the inner surface of the cushion sheet layer 9, the cushion sheet layer 9 is joined to the outer peripheral surface of the winding drum 3 with an adhesive or an adhesive material 17 as shown in FIG. 7. You can leave it.
In the reel-wound optical fiber of the present invention, basically, as described above, both the biting of the cushion sheet layer 9 with respect to the protrusion 13 and the pressing contact (friction resistance) with respect to the outer peripheral surface of the winding cylinder are incompatible. Thus, the occurrence of slipping of the cushion sheet layer 9 with respect to the winding drum 3 can be effectively prevented, but if the adhesive or the adhesive material 17 is used supplementarily, the occurrence of slipping of the cushion sheet layer 9 can be more reliably performed. Can be prevented. The type of the adhesive or pressure-sensitive adhesive material 17 is not particularly limited, and an appropriate material may be selected according to the materials of the cushion sheet layer 9 and the reel 7. However, even if the bonding force by the adhesive or the adhesive material is not sufficient, it is avoided that the effect of preventing the occurrence of slipping is not sufficient due to the biting into the protrusion 13 and the frictional resistance against the outer peripheral surface of the winding drum. Therefore, the selection of the adhesive or the pressure-sensitive adhesive material 17 is wide, and even if there is no optimum adhesive or pressure-sensitive adhesive material, there is no practical problem.

  In the above-described embodiment, the protrusion 13 has a rib shape that is continuous in a direction parallel to the rotation center axis of the reel 7. However, the protrusion 13 is not necessarily required to have a rib shape that is continuous in the above direction. An independent peak-shaped protrusion may be used. And when comprised by the discontinuous independent protrusion part in this way, the number of the protrusion parts was made into two or more, and it separated on the outer peripheral surface of the winding drum 3 at intervals in the direction parallel to the rotation center axis line of the reel 7. It is desirable to form in a state. Furthermore, it is desirable to form it in a discrete state at intervals in the circumferential direction of the winding drum. An example of the reel in that case is shown in FIG. 8, and another example is shown in FIG.

  In the example of FIG. 8, each protrusion 13 has, for example, a conical shape, and a large number of the conical protrusions 13 are spaced in a direction parallel to the rotation center axis O of the reel 7, and It forms so that it may protrude from the outer peripheral surface of the winding drum 3 in the discrete state at intervals also in the circumferential direction.

  In the example of FIG. 9, each of the protrusions 13 has a triangular (mountain) cross-sectional shape orthogonal to the rotation center axis O of the reel 7, for example, but its cross section in a direction parallel to the rotation center axis O of the reel 7. It remains in the shape of a triangle and extends in a length shorter than the width of the winding drum 3 (= distance between the flanges 5 and 5 on both sides), and a plurality of protrusions 13 of that shape are connected to the rotation center axis O of the reel 7. It is formed so as to protrude from the outer peripheral surface of the winding drum 3 in a discrete state with an interval in the parallel direction and also in the circumferential direction of the winding drum 3.

  In the above-described embodiment, the cross-sectional shape perpendicular to the rotation center axis O of the reel 7 in the protrusion 13 is shown as being line-symmetric with respect to the radial line of the winding drum 3. Here, for example, in the case of the triangular protrusion 13, the inclined surface on the side facing (facing) the sliding direction of the cushion sheet layer 9 functions to prevent sliding, and in that case The larger the inclination angle of the inclined surface, the more effectively the slip can be prevented. However, if the inclination angle is increased while maintaining the symmetrical shape, the protrusion 13 becomes a sharp pointed shape, the strength is lowered, the defect is liable to occur, and the durability is deteriorated. Therefore, in consideration of the direction in which slippage is most likely to occur during actual use, the inclination angle of the inclined surface on the side that exhibits the anti-slip effect most effectively with respect to the slip direction is increased, and the other inclination By making the surface a relatively small angle of inclination, that is, asymmetric, the anti-slip effect is ensured, but the protrusion does not have to be so sharp, and the strength of the protrusion is ensured. Durability can be improved.

An example when the protrusion 13 is asymmetric is shown in FIG.
In the example of FIG. 10, the protrusion 13 has a triangular shape in a cross section orthogonal to the rotation center axis O of the reel 7, but is asymmetric with respect to the radial line of the winding drum 3. Yes. That is, the inclination angles θa and θb of the two inclined surfaces 13A and 13B constituting the outer surface of the protruding portion 13 are different, with one inclined surface 13A having a large inclination angle θa and the other inclined surface 13B having a small inclination angle θb. ing.

  Here, slipping of the cushion sheet layer 9 is likely to occur when the actual reel-wound optical fiber is used, such as rapid deceleration at the winding stage, such as a sudden stop of the reel when the optical fiber screening test is broken, and light. This is the acceleration at the start of fiber drawing, but compared to the acceleration at the start of drawing, the deceleration at the time of disconnection during winding of the optical fiber, such as the disconnection in the screening test, is more rapid and slippage occurs. Cheap. Therefore, it is only necessary to determine the direction of the protrusion so that the inclined surface 13A having a large inclination angle θa faces the direction of the slip that occurs during winding.

  Specifically, as shown in FIG. 10, if the winding direction (the direction of rotation of the reel during winding) is D1, the cushion sheet layer 9 is moved up to that point by rapid deceleration during winding. Due to the inertial force, slipping tends to occur in the direction D1 with respect to the winding drum. On the other hand, since tension in the direction of arrow D2 is applied to the side of the optical fiber winding layer 11 during unwinding, the cushion sheet layer is likely to slip in the direction of D2 with respect to the winding drum at the start of unwinding. However, since the rapid deceleration during winding is more rapid than the acceleration at the start of feeding, in the example of FIG. 10, the inclined surface 13A having a large inclination angle θa is relative to the slip direction D1 due to the rapid deceleration during winding. Thus, the direction of the protrusion 13 is determined.

  By adopting such a configuration, slipping due to sudden deceleration during winding can be prevented by the inclined surface 13A having a large inclination angle, and slipping due to acceleration at the start of feeding has a relatively small inclination angle. Although the inclined surface 13B is subjected to the acceleration, the acceleration at the start of the feeding is relatively moderate. Therefore, even the inclined surface 13B having a small inclination angle can prevent the slip.

Furthermore, on the premise of the asymmetrical protrusion 13 as described above, in order to obtain the slip prevention effect of the cushion sheet layer 9 reliably and stably regardless of the direction of winding / unwinding, acceleration, or deceleration. An example of the configuration is shown in FIG.
In FIG. 11, a plurality of protrusions 131 and 132 are formed at intervals in the circumferential direction of the winding drum 3. Here, a certain protrusion is denoted by reference numeral 131, and another protrusion adjacent to the protrusion 131 in the circumferential direction of the winding drum 3 is denoted by reference numeral 132. Each of the protrusions 131 and 132 has a triangular shape in a cross section perpendicular to the rotation center axis of the reel 7, but is asymmetric with respect to the radial line of the winding drum 3. That is, the inclination angles of the two inclined surfaces 131A, 131B; 132A, 132B constituting the outer surfaces of the protrusions 131, 132 are different. Moreover, the arrangement of the protrusions 131 and 132 is determined so that the inclined surface 132A with the large inclination angle of the other protrusion 132 is positioned on the side close to the inclined surface 131A with the large inclination angle of one protrusion 131. Yes. That is, when viewed in one circumferential direction D1 of the winding drum 3, the inclination angles of the inclined surfaces of the protrusions 131 and 132 are alternately reversed.

In such an embodiment, the cushion sheet layer 9 can be prevented from slipping reliably and stably regardless of the direction of rotation of the reel 7 during winding or unwinding in the optical fiber manufacturing process, acceleration, or deceleration. An effect can be obtained.
In other words, when using an actual reel-wound optical fiber, the direction of winding and unwinding may vary depending on the winder and unwinder in the optical fiber manufacturing process, etc., and an empty reel can be used as a winder or unwinder. Usually, it varies depending on the mounting direction when mounting. Moreover, as already described, even if the winding direction and the feeding direction are constant, the direction of slipping of the cushion sheet layer 9 is reversed between acceleration and deceleration. However, as shown in FIG. 11, the cross-sectional shapes of the protrusions 131 and 132 are asymmetric, and the inclination angles of the inclined surfaces of the adjacent protrusions 131 and 132 are alternately reversed in the circumferential direction of the winding drum. By setting so that one of the inclined surfaces of each of the protrusions 131 and 132 has a small inclination angle, the cushion sheet layer 9 slips in any direction of D1 and D2. Even when trying to do so, it is possible to reliably prevent the occurrence of slipping of the cushion seat layer by the inclined surfaces 131A, 132B of the inclined portions 131A, 131B; Become.

  Further, in the above-described embodiment, the outer shape (projection contour) of the protrusion 13 in the cross section orthogonal to the rotation center axis O of the reel 7 is a triangle (mountain shape). Needless to say, the outer shape is not limited to a triangle, and it suffices that the outer shape has a surface that crosses the circumference concentric with the outer circumference of the winding drum 3. 12A to 12E show typical examples of the outer shape of the protrusion 13 in the cross section, including the case of the above-described embodiment.

  The protrusion 13 shown in FIG. 12A corresponds to the protrusion in each of the above-described embodiments, and the outer shape in a cross section perpendicular to the rotation center axis of the reel 7 is a triangular shape (mountain shape). In this case, the greater the inclination angle θ of the outer surfaces (inclined surfaces) 13A and 13B of the protrusion 13, the greater the anti-slip effect. Therefore, it is usually desirable that the top of the protrusion 13 has an acute angle. As described above, the direction parallel to the rotation center axis of the reel 7 may be a rib shape continuous in that direction or a discontinuous independent shape. In the case of discontinuity, the protrusion may be conical or pyramidal.

  The protruding portion 13 shown in FIG. 12B has a side surface that rises perpendicularly from the outer peripheral surface of the winding drum, and the outer shape in a cross section perpendicular to the rotation center axis of the reel 7 is a rectangular shape (quadrangle). In this case as well, the direction parallel to the rotation center axis of the reel 7 may be a rib shape continuous in that direction or a discontinuous independent shape. In the case of discontinuity, the protruding portion may be either a columnar shape or a prismatic shape. In the case of a protrusion having a rectangular (quadrangle) cross section, it is desirable to reduce the height or reduce the width in order to ensure biting.

  The protrusion 13 shown in FIG. 12C has a curved shape such as a semicircle or a part of a circle in a cross section orthogonal to the rotation center axis of the reel 7. In this case as well, the direction parallel to the rotation center axis of the reel 7 may be a rib shape continuous in that direction or a discontinuous independent shape. In the case of discontinuity, the protruding portion can have a shape protruding in a hemisphere (or a part of a sphere) or a shape of a part of an elliptic sphere.

  As shown in FIG. 9C, the protrusion 13 shown in FIG. 12D has a curved shape such as a semicircle or a part of a circle, as shown in FIG. Similar to the protrusions in B), the protrusions rise vertically from the outer peripheral surface of the winding drum. In this case as well, the direction parallel to the rotation center axis of the reel 7 may be a rib shape continuous in that direction or a discontinuous independent shape.

  Further, the protrusion 13 shown in FIG. 12E has a trapezoidal outer shape in a cross section perpendicular to the rotation center axis of the reel 7. In this case as well, the direction parallel to the rotation center axis of the reel 7 may be a rib shape continuous in that direction or a discontinuous independent shape.

  In the case of the triangular (mountain) projection shown in FIG. 12 (A), it has already been explained with reference to FIGS. 10 and 11 that the rotational direction of the reel may be asymmetric. Also in the case of the protrusion shape as shown in FIGS. 12C to 12E, it can be asymmetric in the reel rotation direction. In that case, according to FIG. 11, a plurality of protrusions can be provided, and protrusions having different inclination directions can be mixed.

Here, as shown in FIG. 5, it is desirable that the height H of the protrusion 13 is at least a height that does not exceed the thickness T of the cushion sheet layer 9. If the height H of the protrusion 13 exceeds the thickness T of the cushion sheet layer 9, the cushion sheet layer 9 may be lifted and the inner surface thereof may not contact the outer periphery of the winding drum, or even if contacted, no compressive stress is generated. There will be no sufficient slip prevention effect. In practice, it is desirable that the height of the protrusion 13 is about half of the thickness T of the cushion sheet layer 9. In the foam of the polyolefin resin, which is a typical cushion sheet material for an optical fiber reel, if the compressive strain exceeds 50%, the compressive stress becomes extremely large. If the thickness exceeds half, the optical fiber loss may increase. From the viewpoint of enhancing the anti-slip effect without increasing the loss of the optical fiber, it is desirable to arrange a large number of small protrusions 13 having a low height.
On the other hand, the minimum allowable height of the protrusion 13 varies depending on the hardness of the cushion sheet layer 9 and the like. For example, when foamed plastic is 0.3 mm or more, preferably 0.5 mm or more, a sufficient anti-slip effect is exhibited. be able to.

  The number of the protrusions 13 is not particularly limited, and it is possible to exert an anti-slip effect even if it is formed only at one place on the outer peripheral surface of the winding drum, but in order to obtain a reliable and stable anti-slip effect, As shown in each embodiment, it is desirable to form the winding drum 3 at a plurality of locations at intervals in the circumferential direction. Further, when the protruding portion 13 has an independent peak shape that is not continuous in the direction parallel to the rotation axis of the reel 7, the protrusion 13 is formed at a plurality of locations at intervals in the direction parallel to the rotation axis of the reel 7. It is desirable. In this way, when the protrusions 13 are formed at a plurality of locations, if the distance between the adjacent protrusions 13 is too small, the contact area with respect to the outer peripheral surface of the winding drum at the portion other than the protrusions 13 becomes small, and slipping occurs. In view of this, it is desirable to appropriately determine the interval between the protrusions 13.

The manufacturing method of the reel 7 having the protrusion 13 on the winding drum 3 is not particularly limited. For example, when the reel 7 is formed of resin, a shape corresponding to the protrusion is engraved in the molding die, and the protrusion 13 is formed. A method of forming integrally with the reel 7 is representative. In that case, the integrally formed protrusion 13 may be further cut by machining or the like to be adjusted to an appropriate shape and height.
In addition, a groove for embedding the protruding portion may be provided on the surface of the winding drum during resin molding of the reel 7 or by subsequent cutting, and a member for the protruding portion may be embedded in the groove and fixed with a solvent or the like. Or you may affix the sheet | seat in which the projection part is formed previously on the outer peripheral surface of the winding drum 3 with an adhesive agent.

  On the other hand, the cushion sheet layer may be formed with a recess in which at least the tip of the protrusion on the surface of the winding drum is inserted on the surface of the winding drum. In this case, if the depth of the recess is somewhat smaller than the thickness of the cushion sheet layer, the compressive stress in the protruding portion biting area is reduced, and the lateral pressure on the optical fiber becomes more uniform. In this case, the depth of the concave portion of the cushion sheet layer may be smaller than the height of the protruding portion.

  The cushion sheet layer is not limited to one layer, and may have a multilayer structure of two or more layers. In the case of a multi-layer structure, it is possible to select a combination of a material suitable for slip prevention and a material effective for suppressing loss increase of the optical fiber. In that case, for example, it is conceivable to select a slightly harder material on the winding drum side than on the optical fiber winding layer side.

In the actual use of the reel-winding optical fiber of the present invention, as a method for confirming the occurrence of slipping of the cushion sheet layer, for example, the winding start end of the optical fiber is in a tensioned state (not loosened). There is a method of fixing to the buttocks. In this case, if slipping occurs, the winding start end portion of the optical fiber is loosened, so that slipping can be visually confirmed. Alternatively, there is also a method in which a marker is provided on a part of the side surface of the cushion sheet layer, and the movement of the marker position due to slip is visually confirmed from the opening window of the collar.
Furthermore, if the opening window part of the buttock is used, the thickness of the cushion sheet layer due to winding, the presence or absence of a gap between the cushion sheet layer and the surface of the winding drum, and the protrusion bite into the cushion sheet layer It is possible to check the situation.

  Although preferred embodiments of the present invention have been described above, the present invention is of course not limited to these embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Reel winding optical fiber, 3 ... Winding drum, 7 ... Reel, 9 ... Cushion sheet layer, 11 ... Optical fiber winding layer, 13 ... Projection part

Claims (12)

In a reel-wound optical fiber in which an optical fiber is wound around a reel winding cylinder having a cylindrical winding drum,
On the outer peripheral surface of the winding drum, at least one or more protrusions projecting outward in the radial direction of the wound copper are formed,
A cushion sheet layer made of a soft material that can be elastically compressed and deformed is formed on the outer circumferential surface of the wound copper so as to cover the protrusion, and the optical fiber is wound on the outer circumferential surface of the cushion sheet layer. An optical fiber winding layer is formed,
In addition, the cushion sheet layer is elastically compressed and deformed in the radial direction of the winding drum by the compressive stress in the radial direction of the winding drum, whereby the inner surface of the cushion sheet layer bites into at least the tip portion of the protrusion, and A reel-wound optical fiber, wherein at least a part of the inner surface of the cushion sheet layer is in contact with the outer peripheral surface of a region other than the protrusions in the winding drum in a pressed state.   The reel-wound optical fiber according to claim 1, wherein a plurality of protrusions are formed as the protrusions at intervals in the circumferential direction of the outer peripheral surface of the winding drum.   The plurality of protrusions as the protrusions are formed at intervals in a direction parallel to the central axis of the winding drum. Reel wound optical fiber.   The reel-wound optical fiber according to any one of claims 1 to 3, wherein the compressive stress of the cushion sheet layer is due to a winding tension at the time of winding the optical fiber.   The compressive stress of the cushion sheet layer is due to the cushion sheet winding tension when the cushion sheet layer is formed on the outer peripheral surface of the winding drum in addition to the winding tension at the time of winding the optical fiber. Item 5. A reel-wound optical fiber according to Item 4.   All the area | regions of the inner surface of the said cushion sheet layer are contacting either the surface of the said projection part, and the winding drum outer peripheral surface other than a projection part. A reel-wound optical fiber according to any one of the claims.   The inner surface of the cushion sheet layer is in contact with the outer peripheral surface of the winding drum and the surface of the protruding portion between a portion that bites into the tip of the protruding portion and a region that is in contact with the outer peripheral surface of the winding drum other than the protruding portion. There is a non-contact area, and the inner surface of the cushion sheet layer in the non-contact area has a shape that is convex and curved toward the rising portion of the protrusion from the outer peripheral surface of the winding drum. The reel-wound optical fiber according to any one of claims 1 to 5.   The protrusion is asymmetrical in the circumferential direction of the winding drum, and the inclination angle of the outer surface on one side in the circumferential direction of the winding drum and the other side in the circumferential direction of the winding drum in at least the tip portion of the protrusion. The reel-wound optical fiber according to any one of claims 1 to 7, wherein an inclination angle of the outer surface is different.   A plurality of protrusions are formed as the protrusions, and among the plurality of protrusions, at least one of the protrusions is an outer surface on one side in the circumferential direction of the winding drum at least at the tip portion. The inclination angle of the outer surface on the other side is larger than the inclination angle of the outer surface of the other side, and the other one or more protrusions have an inclination angle of the outer surface on the one side in the circumferential direction of the winding drum at least at the tip portion. The reel-wound optical fiber according to claim 8, wherein the reel-wound optical fiber is smaller than an inclination angle of a side outer surface. The cushion sheet layer is joined to the outer peripheral surface of the winding drum by an adhesive or an adhesive material in a region in contact with the outer peripheral surface of the winding drum on the inner surface of the cushion sheet layer. The reel-wound optical fiber according to any one of claims 9 to 10.   In an arbitrary cross section orthogonal to the rotation axis of the winding drum, even if the compressive strain in the region of the cushion sheet layer that is in contact with the outer peripheral surface of the winding drum is the lowest guaranteed environmental temperature during transportation and use 11. The optical fiber winding layer is formed by winding an optical fiber on the cushion sheet layer with a tension such that the optical fiber winding layer is greater than zero. A reel-wound optical fiber as described in 1. The cushion sheet when the optical fiber loss begins to increase when the maximum compressive strain amount of the region of the cushion sheet layer that is bitten by the protrusion is wound on a reel having the same shape and the same dimension without the protrusion. The reel winding according to any one of claims 1 to 11, wherein the height of the protrusion and the winding tension are adjusted so that the amount of strain does not exceed the amount of compressive strain of the layer. Optical fiber.

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