JPH0440173Y2 - - Google Patents

Description

[Detailed explanation of the idea]

"Industrial Application Field" This invention relates to ferrules used for connecting optical fibers. "Prior Art" Generally, when trying to connect optical fibers, a connecting tool called a ferrule is used. That is, as shown in FIG. 5, the optical fiber 3 is made by covering the optical fiber 1 with a plastic coating 2. The tip of the ferrule 4 is finished smooth by inserting it to the tip, and the tip of the ferrule 4 is butted against the ferrule at the tip of another similarly processed optical fiber to integrate the two. It is designed to connect optical fibers. As ferrules used for connecting the optical fibers, those shown in FIGS. 2 to 4 are conventionally known. The ferrule A shown in FIG. 2 includes a first support member 6 having a fiber insertion hole 5 in the center, into which an optical fiber is inserted, and a ferrule A that is disposed inside the tip of the first support member 6 to allow the optical fiber to be inserted. and a second support member 8 having a fiber insertion hole 7 into which the pulled out core wire is inserted, and arranged so that the fiber insertion hole 5 and the fiber insertion hole 7 communicate with each other. Further, the first support member 6 is made of stainless steel, and the second support member 8 is made of ceramic. The ferrule B shown in FIG. 3 includes a first support member 11 having a fiber insertion hole 10 in the center into which an optical fiber is inserted, and a core wire insertion hole 12 into which a cored wire of the optical fiber is inserted. A second support member 13 having a second support member 13 is disposed along the insertion direction of the optical fiber, and is disposed so that the fiber insertion hole 10 and the core wire insertion hole 12 communicate with each other. The supporting member 11 is made of stainless steel, and the second supporting member 13 is made of ceramic. In the ferrule C shown in FIG. 4, a fiber insertion hole 14 into which an optical fiber is inserted and a fiber insertion hole 15 into which a cored wire of the optical fiber is inserted are provided in communication along the central axis. It is integrally formed from plastic. ``Problems to be solved by the invention'' By the way, the ferrules A, B, and ferrules made of stainless steel, ceramic, and plastic mentioned above,
C, each has the characteristics shown in Table 1 below (in the table, ferrules made of stainless steel are indicated as "stainless steel", and hereinafter the same applies to "ceramic" and "plastic"). ).

[Table] According to Table 1 shown above, for example, when a ferrule is made of ceramic, it is superior to a ferrule made of stainless steel or plastic in terms of precision, strength, and durability, but the polishing time and The problem is that it is inferior to ferrules made of stainless steel or plastic in terms of manufacturing cost and weight. The accuracy shown in Table 1 above refers to the positioning accuracy of the core wire to reliably connect two optical fibers, and the polishing time refers to the precision required to polish the tip surface of the core wire. refers to time. "Means for solving problems" This idea was made in consideration of the above circumstances, and the purpose is to provide a ferrule that can obtain excellent evaluations in all comparison items.
In order to achieve this purpose, this invention includes a ferrule body made of plastic and having a fiber insertion hole formed in the center into which an optical fiber is inserted; a core wire support member formed of ceramic and having a first core insertion hole formed in the center into which the core wire of the optical fiber is inserted; , and is made of plastic and has a second core wire insertion hole in the center through which the core wire is inserted, and the end surface thereof is polished together with the end surface of the core wire of the optical fiber during polishing. The fiber insertion hole and the first and second core wire insertion holes are arranged with the same axis. "Function" According to this invention, since the ferrule body disposed at the rear is made of plastic, it is easy to mold the flange, for example.
Since the core fiber support member placed in the center and used for overall positioning is made of ceramic, the optical fibers placed in the first and second insertion holes can be positioned with high precision. be able to. Furthermore, since the plate to be polished disposed at the front is made of plastic, it is possible to easily polish the tip end surface of the optical fiber core placed in the second core wire insertion hole. . "Example" An example of this invention will be described with reference to FIG. In the figure, the ferrule indicated by the symbol D is:
There is a flange 19 on the outside formed of plastic.
A ferrule main body 20 having a ferrule main body 20, a core wire support member 21 formed of ceramic such as zirconia or alumina and fixed to the tip of the ferrule main body 20, and a core wire support member 21 formed of plastic,
A cover 22 is fixed to the tip of the core wire support member 21. To explain each component of the ferrule D, the front part of the ferrule main body 20 and the rear part of the core wire support member 21 have a dovetail 20a and a dovetail groove 21a.
are formed, respectively, and the ferrule main body 20 and the core wire support member 21 are held in a connected state by engaging the dovetail grooves 21a with these dovetails 20a. the ferrule main body 20, the core wire support member 21,
Fiber insertion holes 23, 24, and 25 into which optical fibers are inserted are provided in the central axis of the cover 22 so as to communicate with each other. The fiber insertion hole 23 is formed to have approximately the same diameter as the outer diameter of the optical fiber 32 in which the core wire 30 is covered with a coating material 31 such as plastic, and is a fiber insertion hole (first and second core wire insertion hole). 24 and 25 are formed to have approximately the same diameter as the core wire 30 of the optical fiber 32. The optical fiber 32 is inserted into the fiber insertion hole 23 from the direction of arrow a, and the core wire 3 of the optical fiber 32 is inserted into the fiber insertion holes 24 and 25.
0 is inserted from the same direction. By polishing the end surface of the core wire 30 of the optical fiber 32 that has been inserted into the fiber insertion hole 25, the end surface of the core wire 30 of the optical fiber 32 that has been inserted into the fiber insertion hole 25 is polished to match the end surface of the core wire of another optical fiber processed in the same manner. Abutted together, the two ferrules are arranged in connection. The ferrule D described above is manufactured by integrally molding the ferrule main body 20, the core wire support member 21, and the cover 22. That is, the core wire supporting member 21 is placed in the cavity of the mold, and a portion of a molding pin (for example, formed in the same shape as the optical fiber 32 from which the core wire is exposed) corresponding to the core wire is placed. The ferrule D is inserted into the fiber insertion hole 24 of the core wire support member 21, and in this state, the ferrule D is integrally molded by injecting molten plastic into the remaining portion of the cavity. ing. The process of connecting optical fibers using the above ferrule will be explained. First, insert the optical fiber 32 with the core wire 30 out into the fiber insertion hole 2.
3 to 25 from the direction of arrow a, the covering material 31 of the fiber 32 is placed in the insertion hole 23, and the core wire 30 of the fiber 32 is inserted into the fiber 32 from the direction of arrow a.
are arranged in the insertion holes 24 and 25. In this state, cover the tip end surface of the optical fiber 32 with the cover 2.
2, the end face of the fiber 32 is formed flat. The optical fibers 32, 32 are connected by abutting the end surfaces of the core wires 30, 30 of the pair of ferrules D, D, in which the optical fibers 32 are arranged in this manner. That is, the ferrules D, D are inserted into a cylindrical socket (not shown), and the inner circumferential surface of the socket supports the outer circumferential surface of the cable support members 21, 21. , 21 are positioned, the core wires 30, 30 of the optical fibers 32, 32 are arranged in a straight line, and the tip surfaces of the optical fibers 32, 32 are butted against each other. Therefore, in the above optical fiber connection ferrule, since the core wire support member 21 supported by the socket is molded from ceramic, the core wires 30, 3 of the optical fibers 32, 32
Good positioning accuracy with respect to 0. In other words, the core support member 21 directly supported by the socket
Since only the portions are made of ceramic such as zirconia or alumina, which does not easily deform, the optical fibers 32, 32 can be positioned with respect to the core wires 30, 30 with high precision, and the ferrules other than the core wire support member 21 can be positioned with high precision. Since the main body 20 and cover 22 are made of a material such as plastic, manufacturing costs and weight can be kept low compared to conventional ferrules made entirely of ceramic. The features of the ferrule D constructed as described above were compared with a ferrule molded entirely from ceramic (comparative example), and the results are shown in Table 2 below.

[Table] According to Table 2 above, it can be seen that the ferrule D of the present invention is superior to the ferrule molded from ceramic. Considering each comparison item, in the above ferrule D, since the fiber supporting member 21 is made of ceramic, it can be placed without causing any positional deviation with respect to the socket, and the optical fiber 32 can be positioned easily. can be carried out with high precision, and is also excellent in terms of strength and durability. Furthermore, since the cover 22 at the tip is made of plastic, it is easy to polish the front end surface of the core wire 30, and since the ferrule body 20 is made of plastic, the flange 1 can be easily polished.
It is easy to mold, such as No. 9, and the weight can be reduced compared to the case where the entire body is made of ceramic. Note that an engagement means similar to the dovetail 20a and dovetail groove 21a formed between the ferrule bodies 20 and 21 is provided between the core wire support member 21 and the cover 22, so that the core wire support member 21 and 22 may be firmly connected. "Effects of the invention" According to this invention, since the ferrule body located at the rear is made of plastic, it is easy to mold the flange, for example.
Since the fiber supporting member, which is placed in the center and performs overall positioning, is made of ceramic, the optical fiber placed in the insertion hole can be positioned with high precision. That is, since the part of the core wire support member supported by the socket is formed of ceramic such as zirconia or alumina that is not easily deformed, it is possible to position the optical fiber with respect to the core wire with high precision. Further, since the core wire support member to which force is applied from the outside is made of ceramic, excellent results can be obtained in terms of strength and durability. On the other hand, since the ferrule body other than the core wire support member is made of polished plate plastic, etc., manufacturing costs and weight can be kept low compared to conventional ferrules made entirely of ceramic. Furthermore, since the plate to be polished placed at the tip is made of plastic, it is easy to polish the tip end surface of the optical fiber core placed in the insertion hole. The connection between the core wires of the optical fibers is reliably performed. Therefore, according to the above invention, the advantages of ceramic and plastic can be obtained together. In other words, it is superior in terms of polishing time, manufacturing cost, and weight compared to a model entirely molded from ceramic, and it is superior in precision, strength, and weight compared to a model entirely molded from plastic. It has the effect of being excellent in terms of durability.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing the configuration of an embodiment according to the present invention, FIGS. 2 to 5 are views showing a conventional ferrule, and FIG. 2 is a front sectional view showing the first conventional example. , Fig. 3 is a front sectional view showing the second conventional example, and Fig. 4 is a front sectional view showing the second conventional example.
The figure is a front sectional view showing the third conventional example, and FIG. 5 is an explanatory diagram showing the connection between the ferrule and the optical fiber. D...Ferrule, 20...Ferrule main body,
21... Core wire support member, 22... Cover (plate to be polished), 23... Fiber insertion hole, 24...
Fiber insertion hole (first core wire insertion hole), 25...
...Fiber insertion hole (second core wire insertion hole), 30
... Core wire, 31 ... Covering material, 32 ... Optical fiber.

Claims (1)

[Claims for Utility Model Registration] A ferrule body 20 made of plastic and having a fiber insertion hole 23 in the center into which an optical fiber is inserted; A wire support member 21 having a first wire insertion hole 24 formed in the center thereof into which the core wire 30 of the optical fiber 32 is inserted; It is fixedly fixed and made of plastic, and has a second core wire insertion hole 25 in the center through which the core wire is inserted, and its end surface is polished together with the end surface of the core wire of the optical fiber during polishing. An optical fiber connection comprising: a plate to be polished 22, wherein the fiber insertion hole and the first and second core wire insertion holes are arranged with the same axis. Ferrule.