JP2673818B2 - Method and apparatus for coating optical fiber fusion spliced portion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a method for coating a fusion spliced portion of an optical fiber and an apparatus used for the method.

[Prior art]

When fusion splicing two optical fibers,
The coatings are peeled off at the ends of both optical fibers, and then the two are abutted and fused together. Therefore, after fusion splicing, it is necessary to cover the peeled connection portion. Conventionally, in order to form a coating having the same outer shape as the original coating, an injection molding method is used to cover the fusion spliced portion with a resin. That is, as a mold for injection molding, a mold that is divided into two parts that forms a cavity having the same shape as the original coating is used, and after the fusion splicing part is set in the cavity, these molds are joined, An ultraviolet curable resin is injected through an injection hole provided in the mold. Then, the mold is made of an ultraviolet-transparent material, and after the resin is injected, ultraviolet rays are irradiated from the outside of the mold to cure the resin.

[Problems to be solved by the invention]

However, according to the conventional coating method, the ultraviolet curable resin filled in the injection hole connected to the cavity is also cured by the irradiation of ultraviolet rays and remains as a so-called burr after the mold is removed and remains in the form of protrusions. Therefore, not only the work of removing this burr is required, but also the shape of the coating portion is greatly damaged by the deburring process, making it difficult to finish the same shape as the original coating. There is a problem in that the transmission loss increases after the core is damaged. According to the present invention, it is possible to cover the fusion splicing portion so as not to generate burrs, thereby eliminating the deburring work and solving the problem in the deburring process. An object of the present invention is to provide a method and an apparatus for coating an optical fiber fusion spliced portion.

[Means for Solving the Problems]

In order to achieve the above object, in the method for coating an optical fiber fusion splicing portion according to the present invention, an elongated groove for forming a cavity having a shape substantially equal to the coating outer shape of the optical fiber is provided, and An ultraviolet-impermeable member and an ultraviolet-transmissive member are arranged in the longitudinal direction, and a resin injection hole communicating with the groove is provided in the ultraviolet-impermeable member. In the groove
The optical fiber fusion-spliced portion with the coating removed is positioned so that the optical fiber fusion-spliced portion is merged, and then the ultraviolet-curable resin is injected from the injection hole to fill the inside of the cavity and the optical fiber with the coating removed. Fill the periphery of the fusion splicing portion, and then move the fused mold relative to the optical fiber so that the optical fiber slides along the elongated groove. Allow all the peeled parts to reach the position surrounded by the UV-transparent member of the above mold, and then irradiate UV through the UV-transparent member to cure the UV-curable resin in the cavity. ing. Further, the apparatus used for this coating method is such that elongated grooves are formed in each of them so that a hollow portion having a shape substantially equal to the outer shape of the coating of the original optical fiber is formed at the time of merging, and ultraviolet rays are not applied in the longitudinal direction of the grooves. A divided mold in which a transparent member and an ultraviolet-transparent member are arranged, and a resin injection hole communicating with the groove is provided in the ultraviolet-impermeable member, and the cavity forming groove is covered. Of the optical fiber fusion spliced portion of the removed, the combination mechanism for combining the mold, and the mold in the combined state, the optical fiber slides along the elongated groove, to the optical fiber The relative movement relative to each other, the moving mechanism to reach the position where all the peeled portions of the fusion-spliced portion are surrounded by the ultraviolet-transparent member of the mold, and the ultraviolet-transparent member of the mold. Flip comprising a light source for irradiating ultraviolet rays to the cavity portion.

[Action]

Make a mold for resin injection molding in advance. This type is
It is divided, and each is provided with an elongated groove, and when the molds are combined, these grooves form a cavity having a shape substantially equal to the outer shape of the coating of the optical fiber. An ultraviolet impermeable member and an ultraviolet transparent member are arranged in the longitudinal direction of the groove to form a divided mold. Then, the ultraviolet ray non-transmissive member is provided with a resin injection hole communicating with the groove. The molds are united so that the optical fiber fusion splicing portion is sandwiched between the grooves. At this time, the part of the optical fiber fusion spliced part where the coating is removed is set in the groove. Therefore, an ultraviolet curable resin is injected through the resin injection hole to fill the cavity. Then, the resin around the fusion spliced portion of the optical fiber from which the coating has been removed is filled. Since the shape of the cavity formed by the groove is made substantially the same as the outer shape of the original coating, the outer shape of the resin covering the peeled portion becomes the same as the outer shape of the coating. Next, the mold is moved relative to the optical fiber in the length direction of the optical fiber in the combined state. This causes the optical fiber to slide along the elongated groove.
This movement is performed until all the fusion-spliced portions from which the coating of the optical fiber has been peeled off reach the position where they are covered with the above-mentioned UV-transmissive member. When the portion where the coating is peeled off reaches a position where it is entirely covered by the ultraviolet-transparent member, the above movement is stopped, and the cavity is irradiated with ultraviolet rays through the ultraviolet-transparent member. Then, the portion where the coating is peeled off, that is, the fusion-spliced portion filled with the resin before curing is irradiated with ultraviolet rays through the ultraviolet ray transmitting member, and the resin in this portion is cured. On the other hand, since the irradiated ultraviolet rays do not pass through the ultraviolet ray non-transmissive member, the resin injection hole provided in this portion, that is, the resin therein, is not irradiated with the ultraviolet rays. Therefore, only the resin around the fusion spliced portion is cured by the irradiation of ultraviolet rays, and the resin in the injection hole is not cured. Moreover, the fact that the fusion-bonded portion is entirely surrounded by the UV-transmissive member means that the injection hole is provided on the side of the UV-impermeable member, which means that the fusion-bonded portion is surrounded by the UV-permeable member. This means that the resin and the resin in the injection hole are not connected. for that reason,
When the mold is removed after curing, burrs do not occur in the resin portion around the cured fusion-spliced portion.

【Example】

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an example of an apparatus used for carrying out a coating method according to an embodiment of the present invention. As shown in FIG. 1, a holder 11 for holding an optical fiber in a longitudinal direction on a main frame 1, 12 is fixed, and further, the main frame 1 holds a movable substrate 2 so that the optical fibers held by the holders 11 and 12 can be moved in the longitudinal direction, that is, in the vertical direction in this example. The moving substrate 2 is forcibly moved up and down by a motor or the like (not shown). Then, slide bases 21 and 22 which are slidable to the left and right are attached to the movable board 2, and when the knobs 23 and 24 are turned, the slide bases 21 and 22 are moved to the left and right via an appropriate gear mechanism or the like. Thus, the position in the left-right direction can be finely adjusted. Molds 3 and 4 for injection molding are fixed to the slide bases 21 and 22, respectively, and ultraviolet light sources 5 and 6 are fixed by arms not shown. The molds 3 and 4 are two-divided molds for injection molding, in which the ultraviolet non-transmissive members 31 and 41 and the ultraviolet transmissive members 32 and 42 are joined and integrated by an adhesive or screws. Thus, the grooves 33 and 43 are formed at the opposite positions on the facing side. The grooves 33 and 43 form a cavity filled with the ultraviolet curable resin when the molds 3 and 4 are closely adhered to each other. In this embodiment, the cross section of the optical fiber is circular as will be described later. The groove has a semicircular cross section with a radius equal to the radius of the outer shape. Further, in this embodiment, an injection hole 34 connected to the groove 33 on the mold 3 side is provided in the ultraviolet ray non-transmissive member 31. In such a coating device, as shown in FIG.
First, the optical fibers 7 and 8 that are fusion-spliced to each other are held in a holder.
Hold at 11 and 12. The coating of the fusion splicing portion 72 is peeled off, and the upper end of this portion 72, that is, the lower end of the coating of the optical fiber 7
71 so that it is located slightly above the position of the injection hole 34,
The moving substrate 2 is moved. Next, the positions of the slide bases 21 and 22 are finely adjusted by turning the blocks 23 and 24 so that the center axes of the held optical fibers 7 and 8 coincide with the center axes of the grooves 33 and 43. To adhere. Then, the cavities formed by the grooves 33 and 43 are blocked by the coating of the optical fibers 7 and 8 above and below, except for the fusion splicing portion 72, and open to the outside only through the injection hole 34. Therefore, the injection hole 34
Further, an ultraviolet curable resin is injected into the above cavity to fill the periphery of the fusion spliced portion 72 where the coating is peeled off (second
See figure). Next, the moving substrate 2 is moved upward while applying the injection pressure to the resin. Then, the molds 3 and 4 move upward relative to the optical fibers 7 and 8 held by the holders 11 and 12. That is, the optical fibers 7 and 8 are in the groove 3
It slides in 3, 43 and goes downwards with respect to the molds 3, 4. Then, as shown in FIG. 3, boundaries 35 and 45 between the ultraviolet non-transmissive members 31 and 41 and the ultraviolet transmissive members 32 and 42 of the molds 3 and 4, respectively.
However, the moving substrate 2 is moved until it is above the upper end 71 of the fusion splicing portion 72. At this time, since the resin is applied with the injection pressure, the resin is always filled with a predetermined pressure inside the cavity formed by the molds 3 and 4, and therefore, air is mixed in due to this movement, Alternatively, there is no fear of running out of resin. When in such a state as shown in FIG. 3, the light sources 5 and 6 emit ultraviolet rays. Then, the ultraviolet rays pass through the ultraviolet ray transmitting members 32 and 42 and are applied to the fusion splicing portion 72 to cure the resin filling the portions. The injection hole 34 is provided in the ultraviolet non-transmissive member 31, and the upper end of the fusion splicing portion 72 is located below the boundaries 35, 45 between the ultraviolet non-transmissive members 31, 41 and the ultraviolet transmissive members 32, 42. Since the resin filled in the fusion spliced portion 72 and the resin filled in the injection hole 34 are completely cut off, the resin filled in the injection hole 34 is not exposed to ultraviolet rays and the resin in this portion is not cured. Therefore, the fusion splicing part
After the resin of 72 is sufficiently cured, the molds 3 and 4 are opened, and the optical fibers 7 and 8 are removed from the holders 11 and 12.
It can be realized that 72 is coated so that it has the same outer shape as the coating of other parts, and burrs etc. are not possible. For this reason, the coating having the same outer shape as the coating of the original optical fibers 7 and 8 is formed in the state of being removed, and the deburring work is unnecessary, the working time can be shortened, and the deburring process is caused. It is possible to solve the problems of deformation and transmission loss, and to improve the reliability of the fusion splicing part.

【The invention's effect】

According to the optical fiber fusion splicing portion coating method and apparatus of the present invention, it is possible to form a coating having the same outer shape as the original coating on the fusion splicing portion in a state where the fusion splicing portion is kept removed from the mold, and deburring work is performed. Since it is not necessary, work time can be shortened, and moreover,
The problems of deformation and transmission loss due to the deburring process can be solved, and the reliability of the fusion splicing portion can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an embodiment of the present invention, and FIGS. 2 and 3 are sectional views showing respective steps. 1 ... Main frame, 11, 12 ... Optical fiber holder, 2
...... Moving board, 21, 22 …… Slide base, 23,24 ……
Knob for fine adjustment of position 3, 4 ...... 2 divided molds for injection molding, 31, 41 ...... UV non-transmissive member, 32, 42 ...... UV transmissive member, 33, 43 ...... Groove, 34 ...... Injection holes, 7, 8 ...
Optical fiber, 72 ... fusion splicing part.

Claims (2)

(57) [Claims] 1. An elongated groove for forming a cavity having a shape substantially equal to the outer shape of a coating of an optical fiber is provided, and an ultraviolet ray non-transmissive member and an ultraviolet ray transmissive member are arranged in the longitudinal direction of the groove. In the ultraviolet impermeable member, a resin injection hole communicating with the groove is provided, the divided mold, in the groove for forming the cavity, the optical fiber fusion splicing portion with the coating removed. Positioning so that, after being combined, the ultraviolet curing resin is injected from the injection hole to fill the cavity to fill the periphery of the optical fiber fusion spliced part where the coating is removed, and then the above The combined mold of (1) is moved relative to the optical fiber so that the optical fiber slides along the elongated groove, and all the portions where the coating of the fusion splicing portion is peeled off are the ultraviolet light of the mold. Surrounded by transparent material Until allowed to reach, and thereafter,
A method for coating an optical fiber fusion splicing portion, wherein ultraviolet rays are radiated through the ultraviolet ray transmitting member to cure the ultraviolet ray curable resin in the cavity. 2. An elongated groove is formed in each of the hollows so that a hollow portion having a shape substantially equal to the outer shape of the coating of the original optical fiber is formed at the time of merging, and the ultraviolet ray non-transmissive member and the ultraviolet ray are provided in the longitudinal direction of the groove. A transparent mold is arranged with a transparent member, and a resin injection hole communicating with the groove is provided in the ultraviolet impermeable member, and a light with the coating removed in the cavity forming groove. A combination mechanism for combining the molds so that the fiber fusion splicing portion is located, and the mold in the combined state, so that the optical fiber slides along the elongated groove, and relatively to the optical fiber. The cavity is moved to a position where all the peeled portions of the fusion spliced portion are surrounded by the UV-transmissive member of the mold and a UV mechanism is provided to the cavity through the UV-transmissive member of the mold. Coating apparatus of the optical fiber fusion splicing part comprising a light source for irradiating.