JPS6337362B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a connector for connecting optical fibers used in optical communications.

In optical communications, means for removably connecting optical fibers are employed at various locations, and one such connection method is called a connector connection.

In this connector connection method, a connector is used as a connection jig, and this connector includes a plug and an adapter that can be fitted with each other.

Among these, the plug is integrally formed on the outer periphery of the end of each optical fiber to be connected to each other, and the adapter is formed in a cylindrical shape and a groove shape so that the two connectors can be fitted therein.

When connecting two optical fibers in the longitudinal direction, the plugs at the ends of each optical fiber are inserted into the adapter in abutting state and fixed by appropriate means, whereby the two optical fibers are connected in axial alignment. be done.

Recently, attempts have been made to manufacture the above connector plugs by resin molding, and although considerable success has been achieved with single-core optical fibers, it has been found that multiple optical fibers in parallel are integrally coated with a flat coating layer. In multi-core optical fibers, or multiple single-core optical fibers arranged in parallel, a single resin-molded connector is provided over the outer periphery of each optical fiber end. In the case where multiple optical fibers are connected at once using two sets of connectors and corresponding adapters, high precision plug forming equipment is required to accurately align each optical fiber. There were considerable difficulties in ensuring accuracy and mass production.

In view of the above-mentioned problems, the present invention has been devised so that when manufacturing plugs for this type of connector, plug accuracy can be ensured by a simple means without relying on the accuracy of the molding equipment, and at the same time mass productivity can be achieved. I did it,
The method will be explained below with reference to illustrated embodiments.

1 to 5 are diagrams explaining the basic principle of the present invention.

The multi-core optical fibers ( _{sometimes referred} to as multi-core optical transmission bodies and multi-core optical _cables ) with _a flat cross section in FIG.
1 ₅ and 1 ₆ are arranged parallel to each other with a high degree of parallelism, and a covering layer 2 made of plastic or the like is formed on the outer periphery thereof.

In the multi-core optical fiber shown in FIG. 1, by removing a part of the coating layer 2 at the middle in the longitudinal direction, each of the optical fibers 1 ₁ to 1 ₆ is removed from the coating removal section 3.
is exposed.

Forming devices 4A, 4 schematically shown in FIGS. 2 and 3
Only the molding spaces 5A and 5B are shown in B, and both molding devices 4A and 4B contain the optical fibers 1 ₁ to 1 ₆ and pin-shaft molded bodies 6 and 6' for molding reference holes. It is now possible to set the

A holding device 7, also shown in FIG. 4, is interposed between the opposing portions of the molding devices 4A, 4B.

This holding device 7 includes a pair of upper and lower holding members 8, 8'.
The overlapping surfaces of both the holding members 8, 8' are provided with V-shaped, concave, etc. grooves 9, 9, 9, etc., and 9', 9', in which the optical fibers ₁₁ to ₁₆ can be fitted and held. ,9'...
... are formed as shown in FIG. 5A, or 9, 9, 9... are formed only on one holding member 8 as shown in FIG. 5B.
... is formed.

Further, in both or one of the holding members 8, 8', there are grooves 10, into which the molded bodies 6, 6' can be held.
10' or 10 is formed.

Each of these grooves 9, 9, 9......, 9', 9',
9'..., 10, 10' are parallel to each other.

In the present invention, as shown in FIGS. 2 and 3, the multi-core optical fibers and molded bodies 6, 6' shown in FIG. 1 are set in molding spaces 5A, 5B of both molding devices 4A, 4B.

In this state, each of the optical fibers 1 ₁ to 1 ₆ exposed in the coating removal section 3 crosses both molding spaces 5A, 5B, and both ends of the molded bodies 6, 6' are connected to each molding space 5A, 5B. The optical fibers 1 ₁ to 1 ₆ and the molded bodies 6, 6' are inserted into the spaces 5A, 5B, and the grooves 9, 9, 9...9' of the aforementioned holding members 8, 8'. ,9',9',10,1
0', etc., so that each set state and parallel state are maintained.

Transfer molding was used here to lower the molding pressure and prevent strain on the optical fiber.
A pretreated resin, such as a thermosetting resin such as epoxy or silicone, or a thermoplastic resin such as polycarbonate or PBT, is injected into the molding spaces 5A and 5B, thereby molding a connector plug.

Figure 6 shows the plug 11 formed in this way.
A and 11B are shown taken out from the molding devices 4A and 4B.

Then, both the plugs 11A and 11B are separated into left and right sides by a cutting line along the - line in FIG.
The end faces to be butted against each other (these end faces are perpendicular to the parallel direction of the optical fibers) are processed to be smooth, resulting in the state shown in FIG. 7.

In this state, the plugs 11A, 11B have reference holes 12A, 12A', 12B formed by the molded bodies 6, 6'.
12B' is also formed.

Plugs 11A, 11 obtained as above
A plurality of optical fibers 1 ₁ to _{1 6} , 1 ₁ to
1 _{and 6} , for example, insert both plugs 11A and 11B into an adapter (not shown) and abut their end surfaces against each other, and at this time, connect the plugs 11A and 11B to each other across the reference holes 12A and 12B, and 12A' and 12B' as shown in the figure. This allows the optical fibers 1 ₁ to 1 ₆ on the plug 11A side and the optical fibers 1 1 to _{1 6} on the plug 11B side to be connected.
Connect the axially.

As explained above, in the present invention, the optical fiber 1
Since the two plugs _11A and 11B are provided in the optical fibers 1 _{to 16} at once, mass productivity during plug molding can be achieved, and even if each of the optical fibers ₁₁ to ₁₆ is separated after plug molding, Since the plug is integrated at the time of molding, there are two molding spaces 5A,
The operation of setting the plugs into the plug 5B can be easily performed, and even when the two plugs 11A and 11B are clamped during molding, only one position needs to be held with one holding device.

After molding the two plugs 11A and 11B for the optical fibers ₁₁ to ₁₆ , both plugs 11
By cutting each of the optical fibers 1 ₁ to 1 ₆ at the boundary between A and 11B, two multi-core optical fibers with plugs are obtained.

In this case, the optical fibers 1 ₁ to _{1 6} that are cut after plug molding are initially integrated as described above, and therefore the optical fibers 1 ₁ to 1 ₆ , 1 ₁ to 1 after being cut are ₆ , there is no dimensional difference or mismatch in arrangement spacing, and both plugs 11A, 11
When connecting the connector via B, both plugs 11
By accurately abutting the end faces of A and 11B, complete alignment (aligned state) of each optical fiber 1 ₁ to 1 ₆ and 1 ₃ to _{1 6} can be obtained.

Of course, the above-mentioned state of alignment is based on the reference holes 12A, 12A', 12B, 12 which are parallel to each of the optical fibers ₁₁ to ₁₆ that are parallel to each other.
Insert the pin shaft into B' and plug both plugs 11A and 11B.
In addition, each reference hole 12A, 12A', 12B, 12B' is set in the molding space 5A, 5B so as to be parallel to each optical fiber ₁₁ to ₁₆ during plug molding. This will give you the required accuracy.

Therefore, high precision is not required for the molding devices 4A, 4B, and the difficulty in manufacturing the molds and the like is also alleviated.

In the above case, each optical fiber 1 ₁ to _{1 6}
Although the plugs 11A and 11B are provided in the multi-core optical fiber shown in FIG. 1, which is integrally coated with the coating layer 2, it is also possible to set a plurality of single-core optical fibers in parallel in both forming devices 4A and 4B. Even in this case, two plugs can be molded at once in the same way as above.

Next, the specific molding apparatus according to the present invention will be explained in the eighth section.
This will be explained with reference to FIGS.

As shown in FIG. 8, the above-mentioned molding devices 4A and 4B are disposed in the longitudinal direction with a holding device 7 interposed between their opposing portions.

As is clear from FIGS. 9 and 10, one of the molding devices 4A consists of a lower mold 13 having two parallel molding spaces 5A, 5A and a corresponding upper mold 14. The upper mold 14 has a press mold 1
5 is also combined.

The lower mold 13 is supported on a base plate 16, and a plate body 18 having a dowel pin 17 is positioned below the lower mold 13 in the same state, so that the dowel pin 17 can be inserted into the lower mold 13. Together with the upper mold 14
is supported by a support member 19 that is vertically movable.

Note that the other molding device 4B, the explanation of which has been omitted, also
It has two parallel molding spaces 5B, 5B and is configured similarly to the molding apparatus 4A.

FIG. 10 shows the clamping molding state of the molding device 4A, and according to these molding devices 4A and 4B, the aforementioned plugs 11A and 11B are obtained in a parallel double state.

Further, the holding device 7 is made up of a pair of upper and lower holding members as described above, and the molded bodies 6, 6' are assembled together.

As explained above, the present invention provides a connector plug provided on the outer periphery of a plurality of parallel optical fibers, and a reference for aligning the optical fibers parallel to each optical fiber from the end face of the plug toward the inside thereof. A method for manufacturing a connector for an optical fiber in which a hole is formed extends over two symmetrical molding spaces that are longitudinally aligned with mutually opposing spacing, and in both molding spaces there are holes that are parallel to each other. A plurality of optical fibers are arranged in parallel, and a molded body for forming a reference hole is arranged in parallel with each optical fiber, and then resin is injected into each of the molding spaces to form each of the above. At the same time, the two plugs are molded around the outer periphery of the optical fiber, and the reference hole is formed in both plugs through the molded body. After the molding, each optical fiber is cut between the two plugs, and the molded body is is characterized by being pulled out from the reference holes of both plugs.

According to the present invention, two plugs can be obtained at once by simply setting a plurality of optical fibers and a molded body for molding a reference hole in two molding spaces, and injecting resin into both molding spaces. Therefore, optical fiber connector plugs can now be mass-produced using simple means, without increasing the precision of the molding equipment.
Satisfactory plug accuracy can be ensured.

In particular, in the case of the present invention, since the method is to mold two plugs simultaneously and separately, after molding both plugs, it is possible to separate the two plugs by cutting only the optical fiber, which does not require cutting the plugs. At this time, there is no risk of damaging the important end face of the plug due to cutting, and the optical fiber can be cut with plenty of time, which simplifies the subsequent end face treatment. Compared to the case where plugs and optical fibers of different materials and hardnesses are cut at the same time, the difficulty of cutting is alleviated, and there are almost no fatal cutting errors that cause large damage.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the optical fiber, Figs. 2 and 3 are a schematic front view and a schematic plan view showing the principle of the manufacturing method of the present invention, Fig. 4 is a side view of the holding device, and Fig. 5 A and B are main part explanatory diagrams showing each example of the holding device;
FIG. 6 is a front view showing one example of a plug molded according to the present invention, FIG. 7 is an end view of two plugs separated after molding according to the present invention, and FIGS. 8 to 10 are 8 is a sectional view of the molding device in an open state taken along the line Y-Y in FIG. 9, and FIG. 10 is a sectional view of FIG. 8 Z-
It is a sectional view of the molded state along the Z line. 1 ₁ to 1 ₆ ...... Optical fiber, 5A, 5B ... Molding space, 6, 6' ... Molded object for forming reference hole, 1
1A, 11B...Plug, 12A, 12A', 1
2B, 12B'...Reference hole.

Claims (1)

[Claims] 1. An optical device in which a connector plug is provided on the outer periphery of a plurality of parallel optical fibers, and a reference hole for aligning the optical fibers is formed from the end face of the plug toward the inside of the optical fiber. In a method for manufacturing fiber connectors, two symmetrical molding spaces are arranged in the longitudinal direction with mutually opposing intervals, and within these molding spaces, a plurality of light beams are arranged in parallel to each other. At the same time as arranging the fibers, a molded body for forming a reference hole is placed in parallel with each optical fiber, and then resin is injected into both molding spaces, and the plug is placed around the outer periphery of each optical fiber. At the same time, the reference holes are formed in both plugs through the molded body, and after the molding, each of the optical fibers is cut between the plugs, and the molded body is pulled out from the reference holes of both plugs. A method of manufacturing an optical fiber connector, characterized in that: