JPH0334042B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method of manufacturing an optical connector.

In the optical fiber connector connection method adopted in the optical communications sector, the outer circumference of one optical fiber end,
A connector portion is formed on the outer periphery of the other end of the optical fiber, and the ends of both optical fibers are butted against each other via the connector portion, thereby achieving a reproducible optical connection.

At this time, the abutting state of both connector parts is maintained by means such as fitting a cylindrical adapter onto the outer periphery of these parts, or fitting pins provided in both connector parts into pinholes.

The above connector connection method is applied not only to connecting one pair of optical fibers, but also to connecting many pairs of optical fibers at once.

In addition, the optical connectors required for this are being manufactured in factories to simplify on-site work, and in-factory production is also changing from metal processing to plastic molding for the purpose of mass production. It's starting to change.

However, when making optical connectors using plastic molding, existing methods have problems with accuracy, molding pressure, burrs, and molding cycles, making it impossible to mold connectors as expected. There is.

In other words, as a precision problem, the pressure of plastic injection into the mold cavity causes bending at the end of the optical fiber, and when the end face is polished after molding the plastic, the above bending causes light beams at the end face of the connector part. Situations have arisen where the fiber end face is displaced from a predetermined position.

Regarding molding pressure and burrs, when plastic is injected into the mold cavity, the plastic leaks out from the V-shaped holding groove for the optical fiber that communicates with the inside of the cavity, making it impossible to obtain high molding pressure. Many burrs have also been generated due to the leaked plastic.

Another problem with the molding cycle is that the optical fiber is held in place by the V-shaped holding groove in the mold during the setting operation, which takes time to heat the mold, and the setting operation also causes the mold to reach a high temperature. It is also not possible to preheat the mold to a certain temperature, thus lengthening the molding cycle.

The present invention has been made to address the above-mentioned problems, and a specific method therefor will be explained below with reference to illustrated embodiments.

In FIGS. 1 and 2, 1A and 1B are a pair of upper and lower molds (molds), and these molds 1A,
1B has cavities 2a, 2b, and rectangular grooves 4a, 4b and semicircular grooves 5a, 5b, 6a, 6 on the front edge side of the molding surfaces 3a, 3b.
b are formed, and rectangular grooves 7a, 7b are formed on the rear edge side of each mold mating surface 3a, 3b.

The mold 1A is also provided with a plastic material injection part 8.

Reference numeral 9 denotes a plastic holding plate, and the holding plate 9 has a pair of left and right through holes 10a, 10b for holding pins, and a through hole 11 for holding an optical fiber between the two through holes 10a, 10b. ₁ , 11 ₂ , 11 ₃ , 11 ₄
are arranged in rows at predetermined intervals.

In addition, each of the through holes 11 ₁ to 11 ₄ formed in the holding plate 9 in the above is connected to a tapered portion 12 and a non-tapered portion 13 having a constant diameter, respectively, as shown in FIG.
It has

14 is a tape-shaped multi-core coated optical fiber;
Optical fibers 15 ₁ , 15 ₂ , 15 ₃ , and 15 ₄ are drawn out from the ends of the multi-core coated optical fiber 14 by removing the coating.

Furthermore, 16 ₁ and 16 ₂ are a pair of pins made of metal or the like.

In the present invention, as shown in _{FIG .}
After passing the ends of the pins 16 1 and 16 2 through the holes 11 ₁ to 11 ₄ of the holding plate 9, and passing the pins 16 ₁ and 16 ₂ through the holes 10a and 10b of the same plate 9, respectively,
These optical fibers 15 ₁ to 15 ₄ and pins 16 ₁ ,
16 ₂ and the holding plate 9 are temporarily fixed using plastic putty applied around the ends of each through hole.

In this way, the optical fibers 15 ₁ to 15 ₄ , the pins 16 ₁ ,
After holding 16 ₂ at a predetermined interval by the holding plate 9,
These are set in the lower mold 1A, but at this time, the coated portion of the multi-core coated optical fiber 14 and the tips of the optical fibers 15 ₁ to 15 ₄ are inserted into the grooves 7a and 4a, respectively, while straddling the cavity 2a.
At the same time, the tips of the pins 16 ₁ and 16 ₂ are fitted into the grooves 5a and 6b, and the retaining plate 9
When this is installed inside the cavity 2a, its front surface is brought into contact with the front side of the cavity 2a.

Next, the lower mold 1 after the above set state is completed.
In A, by overlapping the upper mold 1B, the grooves 4b, 5b, 6b, and 7b are covered with the upper surfaces of the above-mentioned parts, and both molds 1A and 1B are clamped, as shown in FIG. state.

In the following, plastic 17 in an uncured state with a predetermined viscosity is poured into molds 1A and 1 from injection part 8.
After the plastic 17 is filled into the cavities 2a and 2b of B and cured by heat, the plastic molded product is taken out through various operations such as opening and demolding.

FIG. 4 shows a pair of connector parts 18, ₁₈ ' formed in this way. The tip of ₄ has been cut off, and its connector end face has also been polished.

In the case of FIG. 4, one connector portion 18' has pinholes 16 ₁ ' and 16 ₂ ', which can be formed by removing the aforementioned pins 16 ₁ and 16 ₂ .

In addition, the connector part 1 having pins 16 ₁ and 16 ₂
8, when polishing the end face of this pin 16 ₁ , 1
6. Remove _{the 2} , and after polishing it, insert the pin again.

Next, various embodiments of the method of the present invention will be explained, including specific details.

First, regarding the plastic 17 that is the molding material for the connector parts 18, 18', thermosetting resin such as epoxy resin, unsaturated polyester resin, phenol resin, etc. is used, and thermoplastic resin may be used in some cases. .

On the other hand, regarding the holding plate 9, it is also mainly made of plastic, but it may also be made of metal, and if it is made of plastic, the plate 9 may be of the same kind as the plastic 17 or of a different kind. good.

However, if this retaining plate 9 is made of the same material as the plastic 17, the integration with the connector part during molding will be improved.

Each of the optical fiber through holes 11 ₁ to 11 ₄ bored in the holding plate 9 is connected to the tapered portion 12 as described above.
and a non-tapered portion 13.

The tapered portion 12 at this time is for facilitating the insertion of the optical fiber into the through hole, and its slope is
The angle is 30° to 40°, and the length in the axial direction is about 1 mm.

On the other hand, the non-tapered part 13 has a size that fits closely with the outer periphery of the optical fiber, and the hole diameter of the non-tapered part 13 is usually 125 to 150 μm.
m) +2 to 3 μm, and the length is about 0.5 mm.

In addition, the holding plate 9 may contain ferrite powder to impart magnetic force to it. In such a case, the holding plate 9 will be attracted to the inner surfaces of the molds 1A and 1B, so that the holding plate 9 will be attracted to the inner surfaces of the molds 1A and 1B. stability is increased.

In addition, projecting pieces are provided on the inner surfaces of the cavities 2a and 2b, and corresponding hook-shaped hook pieces are provided on the holding plate 9 so that these projecting pieces and the hook pieces are engaged with each other. However, the same stability as above can be obtained.

In the case shown in FIG. 4, connector connection via both connector portions 18, 18' can be made by fitting the pins 16 ₁ and 16 ₂ into the pin holes 16 ₁ ′ and 16 ₂ ′.

Of course, even when using a single coated optical fiber and arranging the optical fibers as described above, the connector part can be formed, and in this case, the cavity 2
In addition to the holding plate 9 that is brought into contact with the front surfaces of the cavities 2a and 2b, a holding plate with through holes (not shown) that is brought into contact with the rear surfaces of the cavities 2a and 2b is also used to maintain the alignment of each optical fiber. hold.

As explained above, the method of the present invention is a method for manufacturing an optical connector in which a connector portion is formed on the outer periphery of the ends of a plurality of optical fibers aligned in a desired arrangement state, and the tips of the ends of the optical fibers are attached to a holding plate. After pulling through the respective through holes, these retaining plates,
It is characterized in that the end of each optical fiber is set in a mold, and a connector portion is formed on the outer periphery of each end of the optical fiber using plastic filled into the mold.

In the present invention having such characteristics, the key parts of each optical fiber end located at the abutting surface of the optical connector are firmly held by the holding plate in the mold, so that the plastic injected into the mold is As a result, there is no possibility that the above-mentioned key points of each optical fiber end are shifted or the mutual spacing between these key points is distorted, so that a high-precision optical connector can be manufactured.

Further, even though the above-mentioned holding plate has through holes through which each optical fiber end can be passed through, these through holes can be tightly fitted with the outer periphery of the optical fiber end. A leakage gap such as a shape-retaining groove does not occur; rather, the presence of this retaining plate increases the sealing effect between the inside and outside of the mold.

Therefore, during the predetermined plastic molding process, the molding pressure will not be reduced due to plastic leakage, and a good connector part can be obtained with a sufficiently high molding pressure, and of course, the generation of many burrs can be prevented.

Furthermore, the spacing and arrangement state of each optical fiber end can be set via a holding plate without depending on the mold, and the mold can be preheated to a predetermined temperature during handling, making it possible to Cycles are shorter and efficiency is increased.

[Brief explanation of the drawing]

The drawing shows one embodiment of the method of the present invention,
Figure 1 is a perspective view showing the mold in the open state, Figure 2
3 is a partially enlarged sectional view of a holding plate, and FIG. 4 is a perspective view of an optical connector manufactured by the method of the present invention. 1A, 1B...Mold, 2a, 2b...Cavity, 9...Holding plate, 11 ₁ to 11 ₄ ...Through hole, 1
5 ₁ to 15 ₄ ... Optical fiber, 17 ... Plastic, 18, 18' ... Connector section.

Claims (1)

[Claims] 1. An optical fiber in which the ends of a plurality of optical fibers aligned in a desired arrangement are set in a mold and a connector portion is formed on the outer periphery of the ends of the optical fibers by filling the mold with plastic. In the method for manufacturing a connector, before setting the end portion of the optical fiber in the mold, a through hole for holding the optical fiber provided in a straight line and a pair of through holes for holding the pin provided on both sides of the through hole are formed. The ends of the optical fibers are respectively pulled through the optical fiber holding holes of the holding plate having a holding plate, and the pins are respectively pulled through the pair of pin holding holes to form a penetrating state, and then the holding plate is held. A method of manufacturing an optical connector, in which a plate, each optical fiber end, and both pins are set in a mold, and a connector part is formed around the outer periphery of each optical fiber end using plastic filled in the mold. 2. The method of manufacturing an optical connector according to claim 1, wherein the holding plate is made of the same type of plastic as the plastic forming the connector portion. 3. The method of manufacturing an optical connector according to claim 1, wherein the holding plate is made of a plastic different from the plastic forming the connector portion. 4. The method for manufacturing an optical connector according to claim 1, 2, or 3, wherein the holding plate contains a magnetic material.