JP2967884B2 - Processing method of tape fiber coating removal part - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a coating removal portion of an optical communication fiber, and requires a sufficient tensile strength for an optical fiber such as a submarine optical communication cable. The present invention is effective in improving the tensile strength of the connecting portion in the connection and improving the connection accuracy of the multi-core wire.

(Prior art and problems of the present invention)

At the time of cable laying, high-level proof tests are performed on optical communication cables in which a large tensile force acts on the cable during the service period, especially undersea optical communication cables, in order to confirm the strength reliability such as tensile strength in advance. Done. Particularly problematic in this proof test are the connection part in the middle of the cable and the connection part in the repeater.

Optical fiber connected by conventional connection method (125φμm)
The tensile strength of the connection part is limited to 0.4 to 0.8 kg. In order to improve the strength reliability of the optical fiber, it is indispensable to improve the tensile strength of the connection.

It is well known that the tensile strength of an optical fiber connection is significantly reduced by the presence of microscopic microscopic flaws on the connection surface.

Fine scratches on the surface of the connection portion are highly likely to occur in the coating removal operation, the connection end surface setting operation, and the fusion splicing operation.
As a method for minimizing the possibility of damaging the optical fiber surface in the coating removing operation and the fusion splicing operation, an optical fiber connection method described in JP-A-63-184712 is known. is there. The outline of the features of this known optical fiber connection method is as follows.

I. B. Chemically removing the connection end of the optical fiber using a chemical (prevention of scratches on the optical fiber surface due to mechanical removal of the coating using a tool such as a stripper); A method of coating and curing a thin UV light curable resin (hereinafter referred to as “UV resin”) on the exposed part except the optical fiber connection tip, and then clamping the coated part with the clamp of the optical fiber fusion splicer. It is.

According to the above (1), scratches on the surface of the optical fiber caused by mechanically removing the coating using a tool such as a stripper are prevented, the exposed portion of the optical fiber is directly clamped by the clamp (2), and the optical fiber is connected by the clamp. This is intended to prevent the surface of the optical fiber from being scratched or abraded by pushing the end in the axial direction.

This conventional optical fiber connection method (hereinafter referred to as "conventional technology") is a solution to the problem sufficiently to significantly improve the optical fiber connection technology. However, in recent years, tapes of optical fibers have been used in order to respond to a demand for increasing the capacity of optical fiber cables. When applying the single-core method of the tape fiber, a bridge of a coating resin, for example, a UV resin is formed between adjacent optical fibers, and a method for a tape fiber is desired.

〔Constitution〕

(I) Regarding the Invention According to Claim 1 [Means Taken for Solving the Problems] The means of the invention according to claim 1 taken for solving the above problems, that is, the solving means are the following elements (a) to (c). ).

(B) A portion of the portion of the tape fiber near the end that is to be fusion spliced is partially removed, and of the coating portion adjacent to the removed section, the portion far from the end is gripped by the fiber clamp and the exposed portion of each fiber is exposed. Of these, the part close to the end is held by a holder directly above the fiber clamp. (B) Each fiber is held under a weak tension. (C) The thin film forming tool is directed toward each fiber exposed part. To move the thin film forming tool into the resin ball held by the thin film forming tool, and then move the thin film forming tool in the axial direction of each fiber to form a resin coating on the exposed portion of each fiber. thing.

In addition, positioning the position of the holder in the above element (a) directly below the clamp is equivalent to the element (a).
Moving each exposed fiber portion of the element (C) toward the thin film forming tool is equivalent to that of the element (C).

[Action]

The holder is located directly above the clamp and straightens by applying tension to each fiber exposed part, so that each fiber exposed part is accurately positioned in the middle of the resin ball of the thin film forming tool, and Does not change during the movement in the direction of each fiber axis.

In addition, since both ends of the exposed portion of each fiber are held at a fixed interval by a holder and a clamp, and tension is applied to all the fibers, the entire length of each exposed portion of the fiber is always mutually reciprocal during resin coating. The spacing is kept constant.

Therefore, the fibers do not approach each other at the exposed portions of the fibers, and a resin bridge is not formed between the fibers, and nonuniform resin coating does not occur.

As described above, the object is sufficiently solved by the means of the present invention.

(2) Regarding the invention according to claim 2 [Means taken for solving the problem] The means of the invention according to claim 2 are the elements (a) to (c) of the means according to claim 1 and the following: And (a ').

(A ') After the resin coating is cured, the tip of the coating and the tip of each fiber are gripped by a clamp, and a fine cut is made by a cutter at a point ahead of the tip of the resin coating, and the tip of the resin coating and the fine A fiber connection end face is formed by pressing two points, one point ahead of a point where a notch is made, and folding it at the point where the notch is made.

[Action]

In the resin coating step and the curing step, the surface of the portion between the clamp for gripping the tip of the coating and the holder for gripping the tip of each fiber exposed portion is not damaged at all. Since two points, the tip of the resin coating and one point ahead of the tip, are pressed and folded between the two points to generate each fiber connection end face, the fiber between this connection end face and the resin coating tip, that is, the fiber, The part used for fusion splicing
In this connection end face generating operation, there is no contact with anything. Thus, its surface is completely intact. For this reason, a decrease in the strength of the fiber due to fine scratches on the outer peripheral surface of the fiber used for fusion splicing is completely prevented.

(Embodiment)

(I) The thin film forming tool of the element (C) of the invention according to claim 1 is a thin film formed plate with slots.

Forming a slot for passing each fiber in the plate, holding the resin ball by dropping resin on this slot, the supporting area for the resin ball is large, so the resin ball is on both the front and back surfaces of the plate. The resin pool of the convex curved surface having a low height is formed by spreading widely.

Therefore, when a resin coating having a uniform resin pool shape is formed on each fiber surface of the tape fiber, the shape becomes close to an ideal shape.

(II) As for the exposed portion of each fiber in the element (A) of the invention according to claim 1, a part of the coating is left at the tip of the exposed portion.

By leaving part of the coating at the tip of each fiber,
Each fiber has its tip held at a fixed interval, preventing each fiber from crossing each other, making it easy to hold the tip of the exposed portion with a holder while holding each fiber at a fixed interval, Can be easier.

(III) V of V-groove alignment tool on vertical line passing through clamp
Fit the end of each fiber exposed part into the groove.

Fit the tip of the exposed part of each fiber into the V groove of the alignment tool,
By applying a weak tension to each fiber, the tip of the exposed portion of each fiber can be easily, easily, and accurately positioned.

〔Example〕

Hereinafter, an example in which the present invention is applied to a tape fiber connection device will be described with reference to FIGS. 1, 2, and 3. FIG.

One end of the tape fiber T is coated with a coating residue S '
To remove the length L, thereby exposing the fiber f. In this example, there are four fibers f.

The removal of the coating is performed using a chemical so as not to damage the fiber surface. For details, refer to the above-mentioned published gazette and JP-A-63-184712.

The coating S of each fiber is gripped by the ordinary fiber clamp 1, and the upper end of the exposed portion is fitted one by one into the V-groove g of the alignment tool 5, and each fiber f is stretched straight under a weak tension. The fiber f is gripped by the holder 4 located directly below the alignment tool 5 and having a fixed positional relationship with respect to the clamp 1. As a result, the fibers f are held substantially parallel to each other and at a substantially vertical angle with a constant spacing.

The UV resin is dropped into the slot 6 of the thin film forming plate 2 as a thin film forming tool to hold the UV resin balls 3 on the thin film forming plate. Thereafter, the thin film forming plate 2 is moved toward the optical fiber f (movement in the direction of arrow A), and the optical fiber f is inserted into the slot 6 and positioned in the middle of the UV resin ball 3. Thereafter, the thin film forming plate 2 is lowered to the position of the coating S in parallel with the optical fiber f (arrow B). As a result, a UV resin coating is formed on the fiber f over the length l of the portion above the coating S.

When the tape fiber pitch is small,
Since a UV resin bridge is formed between the fibers, in this case, the pitch of the V grooves g of the alignment tool 5 is made larger than the core wire pitch of the tape fiber, and the fiber interval of the portion to be coated with the UV resin is made smaller than the fiber pitch. Also increase.

The thickness of the UV resin thin film formed on the outer surface of each fiber f depends on the viscosity of the UV resin and the lowering speed of the thin film forming plate 2. Since it is practically difficult to adjust the viscosity of the UV resin in order to adjust the thickness of the thin film, it is better to adjust the lowering speed of the thin film forming plate.

When the viscosity of the UV resin at room temperature is 6500 (± 1000) CPS, the outer diameter of the coating is 140μ when the descent speed is 0.07mm / sec.
m (fiber wire diameter 125 μm) ± 5 μm. The lower the lowering speed of the thin film forming plate, the larger the thickness of the UV resin thin film.

The fiber coated with the UV resin film is irradiated with ultraviolet light (UV) to cure the resin film. The ultraviolet irradiation is the same as that in the prior art. The timing of irradiating the ultraviolet rays should be as early as possible after the formation of the thin film. As time elapses after the formation of the coating, the uncured coating is deformed by gravity and the uniformity of the thickness is hindered.

After curing the UV resin coating, holder 4 for fiber f
The parts held by must be removed. This removal operation will be described with reference to FIG.

The coating S and the exposed portion of the optical fiber f are gripped by the clamps 10 and 11, and at a point slightly away from the tip of the portion C coated with the UV resin, a very fine surface is formed on the lower surface of the fiber f by the cutter 12. Make a notch,
The distal end surface of the pressing member 13 having an inverted U-shaped cross section is brought into contact with the coated portion C and the exposed fiber portion, and is pushed downward (arrow P) to bend the optical fiber f downward.
Due to this bending, the optical fiber f is broken from the cut point by the cutter 12, and a connection end face is generated. This fractured surface becomes a mirror surface and is extremely smooth. Since this connection end face generating operation is performed by using a pressing member having a tip with an inverted U-shaped cross section, there is no material in a portion to be subjected to fusion splicing of an optical fiber (a portion ahead of the coated portion C). Not even touch. Accordingly, there is no damage to the surface of this portion, and the strength of the connection portion is significantly improved.

The tape fiber pretreated as described above is set in an optical fiber fusion splicing apparatus, a portion coated with a UV resin film is gripped by a clamp, and connected by a conventionally well-known discharge fusion splicing method.

〔effect〕

The subject of the present invention is a new subject. Therefore, solving the problems inherent in the prior art as described above, which solves the above-described problems, is a remarkable effect unique to the present invention.

In addition, according to the present invention, a part of the coating can be left at the tip of the tape fiber (since the connection end face is generated immediately before the fusion splicing step), so that the tips of a large number of core wires have a fixed interval. Since it is held in a state where it is kept, it is extremely easy to attach the tape fiber to the resin coating device,
This has the great advantage that it can be done quickly and that the fibers can be prevented from rubbing against each other and scratching the surface.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a view taken along the line II in FIG. 1, and FIG. 3 is a schematic diagram for explaining a connection end face generating apparatus of the present invention. DESCRIPTION OF SYMBOLS 1 ... Fiber clamp 2 ... Thin film forming plate 3 ... UV resin ball 4 ... Holder 5 ... Alignment tool 6 ... Slot 10, 11 ... Clamp 12 ... Cutter 13 ... Press member T ... Tape fiber S: coating S ': remaining coating f: fiber g: V-groove C: part coated with UV resin

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tsuyoshi Yamada 1440 Mutsuzaki, Sakura-shi, Chiba Pref. 20508 (JP, A) JP-A-64-63905 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02B ^6/ 24-6/255

Claims (6)

(57) [Claims] A portion of a portion of a tape fiber to be fusion spliced which is close to a terminal is partially removed, and a portion of the coating portion adjacent to the removed section, which is far from the terminal, is gripped by a fiber clamp, and each fiber is clamped. Of the exposed part, the part close to the end of the exposed part is held by a holder directly above the fiber clamp with a low tension applied to each fiber, and the thin film forming tool holding the resin ball is moved toward each fiber exposed part. Then, putting the exposed portion of each fiber into the resin ball held by the thin film forming tool, and then moving the thin film forming tool in the axial direction of each fiber to form a resin coating on the exposed portion of each fiber. A method for treating a tape fiber coating removal section. 2. After curing of the resin coating on each fiber, the tip of the coating and the tip of each fiber are gripped by a clamp,
2. The method according to claim 1, wherein the fiber coating is bent at a point ahead of the tip of the resin coating to form a fiber connection end face. 3. The method according to claim 1, wherein the coating is removed by leaving a part of the coating at one end of each fiber. 4. A fine cut is made in the lower surface of each fiber by a cutter, and each fiber is folded by pressing two points, the tip of the resin film and the other point ahead of the fine cut. 3. A fusion splicing end face is formed by applying heat.
A method for treating a stripped portion of a tape fiber according to the above. 5. The method according to claim 1, wherein the resin thin film forming tool is a resin thin film forming plate having a slot. 6. A fiber-exposed portion is fitted to a V-groove of an alignment tool having a V-groove on a vertical line passing through a clamp for grasping a coated tip, and then the fiber-exposed portion is gripped by a holder with a low tension applied to the fiber. 2. The method according to claim 1, wherein the tape fiber coating is removed.