JP3504567B2 - Optical connector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector for terminating optical fiber cords in a butt-connectable manner.

[0002]

2. Description of the Related Art Conventionally, field-installed optical connectors for terminating optical fiber connectors at connection sites other than factories have been proposed. Is being considered. The on-site optical connector is an optical connector of a type in which an optical fiber is inserted and fixed in advance in a ferrule whose tip has been polished to omit the connector polishing work after connection. Before connecting the SC type optical connector to the optical fiber other than for field mounting, the optical fiber should be inserted into all connector housing parts such as rubber boots in advance, and after connecting the tip of the optical fiber to the SC ferrule. It was a process of assembling the entire connector by polishing the tip of the connector.

[0003]

However, it is not preferable in terms of work cost and work efficiency to prepare the polishing equipment at the connection site outside the factory or to carry out the polishing assembly work in a place where the working environment is not good. There was a problem.

In view of the above problems, the present applicant has filed Japanese Patent Application No. 9-
5875 and Japanese Patent Application No. 9-5876 have already been filed. These optical connectors are configured to include an SC-type optical connector ferrule into which an optical fiber has been inserted in advance, and a mechanical splice type connection mechanism for connecting the optical fiber protruding from the ferrule and another optical fiber. . To attach this optical connector to the optical fiber cord, the optical fiber exposed at the end of the optical fiber cord is inserted into the connection mechanism and connected to the optical fiber on the ferrule side.

By the way, since the optical fiber cord end is not inserted into the connection mechanism, it is common that there is an exposed optical fiber in the vicinity of the optical connector without being inserted into the connection mechanism. There was a problem that it was easily damaged. For example, JIS C 5973
When the same exposure length as when inserting directly into the ferrule is secured in the optical fiber of the optical fiber cord terminal, such as the standard SC type optical connector established in 1), only the length corresponding to the dimensions of the ferrule and the connection mechanism is used. Since the optical fiber cord end becomes far from the ferrule, it becomes impossible to store the optical fiber in the standard optical connector. Further, if the exposed length of the optical fiber of the optical fiber cord terminal is shortened, the length of the strength member pulled out together with the optical fiber from the optical fiber cord terminal may be insufficient and the optical fiber cord may not be fixed to the optical connector. The process of exposing the optical fiber and the strength member from the optical fiber cord terminal is generally standardized in conformity with the standard SC optical connector. If this process is changed, the manufacturing efficiency will decrease and the cost will decrease. Will lead to a rise.

The present invention has been made in view of the above problems, and (1) protects an optical fiber exposed between the optical fiber cord terminal and the vicinity of a connecting mechanism of an optical connector assembled to the optical fiber cord terminal. The optical characteristics can be maintained by storing and protecting it in the tube. (2) In addition, the protective tube can be easily attached to the optical fiber cord in a short time by the retractable device that can be attached later.
(3) An object of the present invention is to provide an optical connector in which the protective tube can be easily covered with the protective tube from the end of the optical fiber code to the optical fiber in the vicinity of the connection mechanism only by moving the protective tube in the longitudinal direction of the optical fiber cord. Is.

[0007]

The present invention has the following features to attain the object mentioned above. That is, in the present invention, a ferrule in which an optical fiber is internally fixed and whose tip is polished, and a portion which is disposed on the rear end side facing the polished tip of the ferrule and which projects from the ferrule rear end of the optical fiber And another optical fiber are positioned and aligned, but are butt-connected and connected to each other and clamped to maintain a connected state, and the other optical fiber is housed in a covering material and assembled into a terminal of an optical fiber cord. and an optical connector, inserting the optical fiber to expose the optical fiber cord terminal to the connecting mechanism, wherein
From the connection mechanism to the rear which is the opposite direction to the ferrule
The outer diameter of the optical fiber cord is greater than the outer diameter of the optical fiber exposed between the optical fiber cord end located further rearward than the extending hood and the vicinity of the connection mechanism.
A protective tube having an inner diameter is covered, and the protective tube is fixed to the optical fiber cord end by a retractable device that can be attached later .
An optical connector characterized in that it is allowed to bend is the means for solving the above problems. In addition, according to the present invention,
In the protective tube, expose the optical fiber cord end
Also adopts a configuration in which the optical fiber is stored while ensuring slack.
it can.

The protective tube is preferably made of a flexible material, which enables efficient protection of the optical fiber covered with the protective tube. Further, since the protective tube is fixed to the optical fiber cord end by the retractor, the protective state of the optical fiber by the protective tube can be always maintained good, and the optical characteristics of the optical fiber can be maintained for a long period of time. The protective tube has a length for accommodating all or part of the optical fiber exposed between the connection mechanism and the optical fiber cord end. The retractor can be retrofitted so that the protective tube can be fixed in place. The protective tube covers the optical fiber exposed between the connecting mechanism and the end of the optical fiber cord after inserting the optical fiber of the optical fiber cord into the connecting mechanism. The protective tube does not need to cover the entire length of the optical fiber exposed from the connection mechanism to the optical fiber cord end, but it is more preferable to cover it in a longer dimension. The storage length of the optical fiber in the protective tube can be easily adjusted by the fixing position of the protective tube to the optical fiber cord end. Since the retractor is retrofitted, it can easily correspond to the position where the protective tube is fixed to the optical fiber cord end.

Further, according to the present invention, as described in claim 2,
It is more preferable to employ a configuration in which the tip of the protective tube arranged near the connection mechanism is sandwiched and fixed between fixing parts arranged near the connection mechanism.
The protection tube is stably supported at a predetermined position in the optical connector, and the optical fiber can be stably stored in the protection tube. This optical connector can be applied to a multi-core optical fiber cord as well as a single-core optical fiber cord. An optical connector compatible with multi-core optical fiber cords employs a multi-core ferrule, a connection mechanism, and the like.

According to a third aspect of the present invention, when the protective tube is insertable outside the optical fiber cord and is movable in the longitudinal direction of the optical fiber cord before being fixed, The work of coating the optical fiber with the protective tube can be performed efficiently. In this configuration, the protective tube is inserted in advance at a position separated from the optical fiber cord terminal, the optical fiber exposed at the optical fiber cord terminal is inserted into the connection mechanism, and then the protective tube is moved toward the optical fiber cord terminal. To cover the optical fiber exposed between the optical fiber cord and the connection mechanism. When inserting the optical fiber exposed at the optical fiber cord end into the connection mechanism, the protective tube can be moved to a position away from the optical fiber cord end, so that the protective tube does not interfere with the work of inserting the optical fiber into the connection mechanism. It can be prevented. Further, since the protective tube is inserted into the optical fiber cord, it is possible to prevent inconvenience such as dropping. After inserting the optical fiber into the connection mechanism, when covering the optical fiber exposed between the optical fiber cord terminal and the connection mechanism with the protective tube,
All that is required is to move the protective tube along the optical fiber cord to accommodate the optical fiber. At this time, the storage length of the optical fiber follows the fixing position of the protective tube to the optical fiber cord. Since the protective tube is fixed to the optical fiber cord by the retractable device that can be attached later, it is possible to easily correspond to the fixed position.

[0011]

FIG. 1 shows an optical connector 1 according to one embodiment of the present invention. In the figure, reference numeral 2 is a frame, 3 is a ferrule, 4 is a caulking ring, 4a is a ring, 5 is a spring, 6 is a stop ring, 7 is a hood , and 8 is a knob. The ferrule 3 is applied to an optical connector defined in JIS C 5973, and includes a ferrule body 9 in which an optical fiber is internally fixed, a ferrule hold 10 holding the ferrule body 9, and a connection mechanism 11. It is configured. An optical fiber 12 (bare fiber) is previously inserted and fixed in the ferrule body 9, and the tip surface 13 of the ferrule body 9 is polished by PC (Physical Contact) polishing or the like.

The connecting mechanism 11 is installed behind the ferrule hold 10 (on the back side of the plane of FIG. 1).
The connecting mechanism 11 includes a split rod-shaped element 14 and a C-shaped spring 15 mounted on the outside of the element 14 and having a C-shaped cross section. The element 14 has an aligning groove (not shown) such as a V groove and a U groove inside, and the optical fiber 12 inserted into this aligning groove and aligned is positioned by the clamping force of the C-shaped spring 15 inside. It is designed to be clamped to. At the rear end of the element 14 in the longitudinal direction (the back side in the plane of FIG. 1), an optical fiber 17 (optical fiber single-core wire) exposed by removing the coating material 16a (jacket) of the end of the optical fiber cord 16 is aligned. The optical fiber introducing part 18 for introducing into the groove is provided.

In this connecting mechanism 11, the optical fiber 17 introduced into the element 14 from the optical fiber introducing portion 18 and the optical fiber 12 on the ferrule 3 side are positioned and aligned in the aligning groove in the element 14 for butt connection. Further, the C-shaped spring 15 is clamped in the element 14 by the clamping force to maintain the connected state. Element 14
The bare fiber 17a is previously exposed at the tip of the optical fiber 17 to be inserted into
17a are butt-connected to each other. A portion of the optical fiber 17 where the bare fiber 17a is not exposed is also inserted into the element 14 and clamped and fixed to the element 14.

A wedge insertion groove 20 for inserting a wedge 19 for opening the element 14 is formed on a side portion of the element 14, and the opening 21 of the C-shaped spring 15 is aligned with the wedge insertion groove 20. . The assembled optical connector 1 further includes the connection mechanism 1
The wedge insertion opening 22 opened on the side surface of the stop ring 6 for accommodating 1 is aligned with the wedge insertion groove 20 and the opening 21. Therefore, the wedge 19 is inserted into the wedge insertion groove 20 through the wedge insertion opening 22 of the stop ring 6 and the opening 21 of the C-shaped spring 15.

FIG. 2 shows the vicinity of the caulking ring 4 of the assembled optical connector 1. In FIG. 2, the caulking ring 4 is
Strength member 23 exposed at the end of the optical fiber cord 16
Secure (Kevlar) between the stop ring 6 and
Further, the covering material 16a is caulked and fixed to the ring 4a. The spring 5 is inserted into the stop ring 6 and presses the element 14 to urge the ferrule 3 forward (left side in FIG. 2). As shown in FIG. 1, the protrusion of the ferrule 3 from the frame 2 is restricted by the flange portion 24 of the ferrule hold 10 engaging with the frame 2.

Reference numeral 25 in FIG. 1 is a protective tube. In FIG. 1, the protection tube 25 has an inner diameter larger than the outer diameter of the optical fiber cord 16 and is movable in the longitudinal direction of the optical fiber cord 16 (direction of arrow A in FIG. 1). Further, the protective tube 25 is formed of a flexible material such as synthetic resin and can protect the optical fiber cord 16 and the optical fiber 17 housed therein from being damaged.

In FIG. 1, reference numeral 26 is a retractor (C-shaped clip).
Is. The retractor 26 is made of an elastic material such as plastic and has a C-shaped cross section.
5 is fitted to the boot 27 fixed to the rear end 25a (back right of FIG. 1) of FIG.
Is fixed at an appropriate position on the optical fiber cord 16. For example, for an optical fiber cord with an outer diameter of 1.5 mm, a protective tube 25 having a boot with an outer diameter of 2.35 mm is adopted, and a C-shaped clip with an inner diameter of 2.0 mm is applied.

In FIG. 2, the optical fiber 17 exposed at the end of the optical fiber cord 16 is inserted into the element 14 from the optical fiber introducing portion 18. The end of the optical fiber cord 16 is located behind the hood 7 of the optical connector 1 (on the right side in FIG. 2). The optical fiber 17 has an exposed length of several tens of mm from the element 14 to the end of the optical fiber cord 16. The optical fiber 17 exposed between the end of the optical fiber cord 16 and the caulking ring 4 has a protective tube 2
5 is covered. Therefore, the optical fiber 17 is not exposed between the hood 7 and the end of the optical fiber cord 16 and the optical characteristics of the optical fiber 17 can be maintained.

The boot 27 is arranged behind the hood 7 of the optical connector 1 and is fixed near the end of the optical fiber cord 16 by a retractor 26. On the other hand, the tip 25b of the protective tube 25 is expanded in diameter and is arranged outside the caulking ring 4, and is fixed by being sandwiched between the caulking ring 4 and the ring 4a fixed by caulking from the outside. This allows
Since the protective tube 25 is supported at a fixed position in the optical connector 1 to prevent vibration and the like, the optical fiber 17 is stably stored in the protective tube 25, and the desired optical characteristics can be reliably maintained for a long period of time. it can. Here, the caulking ring 4 and the ring 4a correspond to the fixing component according to the second aspect.

Further, since the bending of the optical fiber 17 is allowed inside the protective tube 25, for example, if the optical fiber 17 having secured slack is housed in the protective tube 25, the optical fiber 17 will not be affected even if tension is applied to the strength member 23. It is possible to prevent tension from acting on 17. In this case, even if the optical fiber 17 has a sufficient slack, the optical fiber 17 does not project outward from the protective tube 25, so it is possible to prevent the optical fiber 17 from interfering with surrounding members,
The optical characteristics of the optical fiber 17 can be maintained.

The optical fiber 1 is provided in the protective tube 25.
In addition to 7, the tensile strength member 23 is also stored. The strength member 23 is pulled out into the caulking ring 4 from the tip 25b of the protective tube. Since the protective tube distal end 25b is fixed to the outside of the crimp ring 4, it does not interfere with the strength member 23 fixed by crimping between the stop ring 6 and the crimp ring 4 mounted on the outside of the stop ring 6.

To assemble the optical connector 1, first, the knob 8 to the stop ring 6 shown in FIG. 1 are assembled, and the caulking ring 4 to the hood 7 and the protective tube 25 are inserted into the optical fiber cord 16. deep. Then, the optical fiber 17 exposed at the end of the optical fiber cord 16 is moved from the stop ring 6 to the optical fiber introducing section 1
The optical fiber 12 on the ferrule 3 side is abutted and connected in the connection mechanism 11 by inserting it into the element 14 via 8.
At this time, the protective tube 25 is arranged at a position separated from the end of the optical fiber cord 16 (right side of arrow A in FIG. 1). As a result, the protection tube 25 can be prevented from interfering with the work of inserting the optical fiber 17 into the element 14, and the workability of insertion and the workability of connection are improved.

Next, as shown in FIG. 2, the tensile strength member 23 is fixed by the caulking ring 4 mounted on the outer side of the stop ring 6.
Secure by crimping. Next, the protection tube 25 is moved in the direction of the stop ring 6 to fix the caulking ring 4 which has been fixed.
The protection tube tip 25b is arranged on the outside of the above, and the ring 4a is caulked and fixed from the outside to fix the protection tube tip 25b. As a result, the optical fiber 17 and the strength member 2
3 is stored in the protection tube 25.

In the process of assembling the optical connector 1, if the protective tube 25 is appropriately moved in the direction of the ferrule 3 to store and protect the optical fiber 17, the tensile strength member 23 is obtained.
Since it is possible to prevent the optical fiber 17 from interfering with the fixing work, etc., the assembling work can be efficiently advanced without damaging the optical fiber 17. Needless to say, when the protective tube 25 interferes with the work, the protective tube 25 is retracted in the direction away from the ferrule 3. For example, when the insertion length of the optical fiber 17 into the connection mechanism 11 of the optical fiber 17 is known in advance, the insertion length of the tip of the optical fiber 17 is left and the other portion is housed and protected in the protective tube 25 before the optical fiber is inserted. By inserting 17 into the element 14, it is possible to prevent a sharp bend or the like from acting on the optical fiber 17 during the inserting operation. Also at this time,
Since the tip of the optical fiber 17 is exposed at the tip of the protective tube 25, there is no fear of impairing the workability of inserting the optical fiber 17 into the connection mechanism 11.

When the caulking and fixing of the strength member 23 and the protective tube tip 25b is completed, the retractor 26 is used to boot 2.
7 to the optical fiber cord 16 terminal, optical connector 1
Build up. Since the retractor 26 can be retrofitted, it is easy to fix the boot 27 at an appropriate position on the end of the optical fiber cord 16. Since the fixed position of the boot 27 at the optical fiber cord 16 terminal has a large degree of freedom, it is only necessary to adjust the fixed position of the boot 27 at the optical fiber cord 16 terminal to the optical fiber from the optical fiber cord 16 terminal to the caulking ring 4. The length of 17 can be easily accommodated.

Therefore, according to this optical connector 1,
Almost the entire length of the optical fiber 17 exposed at the end of the optical fiber cord 16 can be housed and protected in the protective tube 25, and the optical characteristics of the optical fiber 17 can be reliably maintained. Moreover, since the optical fiber 17 can be housed and protected by the protective tube 25 even during the assembling work of the optical connector 1, the assembling workability of the optical connector 1 is improved, and the assembled optical connector 1 has the desired optical characteristics. You can definitely get it.

The optical connector of the present invention is not limited to the above-mentioned embodiment, and it is possible to employ, for example, a retractor or a fixed part whose design is changed. As the fixing component, a configuration other than the crimp ring 4 and the ring 4a can be adopted.

[0028]

As described above, according to the optical connector of the present invention, the following excellent effects can be obtained. (A) The optical fiber exposed from the optical fiber cord end is inserted into the connection mechanism, and the optical fiber exposed between the optical fiber cord end and the vicinity of the connection mechanism is covered and protected by a protective tube. It is possible to stably maintain the light characteristics of the above. (B) Since the protective tube is fixed to the optical fiber cord terminal by the retractable device that can be attached later, the fixing work is easy, and the fixing work can be performed without interfering with the assembling work of other parts of the optical connector. This improves the workability of assembling the optical connector. (C) By adjusting the mounting position of the protective tube to the optical fiber cord end, it is possible to easily cope with the length of the optical fiber exposed between the optical fiber cord end and the vicinity of the connection mechanism. Storage workability is improved.
In addition, bending of the optical fiber is allowed inside the protective tube.
Therefore, for example, an
When stored in a cable, the optical fiber will not be affected even if tension is applied to the strength member.
It is possible to prevent tension from acting on the iva. This
In this case, even if sufficient slack is secured in the optical fiber, the optical fiber
Since the bar does not project outside from the protective tube,
This prevents the optical fiber from interfering with the surrounding
The optical characteristics of the fiber can be maintained.

According to a second aspect of the present invention, when a configuration is adopted in which the tip of the protective tube arranged near the connecting mechanism is sandwiched between fixing parts arranged near the connecting mechanism and fixed, (d) the protective tube is The optical fiber can be stably supported at a predetermined position in the optical connector, and the optical fiber can be stably stored in the protective tube. (E) (d) makes it possible to more reliably maintain the optical characteristics of the optical fiber, The assembled optical connector has an excellent effect that a desired optical loss can be maintained for a long period of time.

According to a third aspect of the present invention, when the protective tube can be inserted outside the optical fiber cord and is movable in the longitudinal direction of the optical fiber cord before being fixed, (F) When inserting the optical fiber exposed at the optical fiber cord end into the connection mechanism, the protective tube can be moved to a position away from the optical fiber cord end, so the protective tube interferes with the work of inserting the optical fiber into the connection mechanism. (G) By inserting the protective tube into the optical fiber cord, it is possible to prevent inconveniences such as dropping during the assembly work of the optical connector. (3) After inserting the optical fiber into the connection mechanism, place the protective tube along the optical fiber cord. Protective tube to the optical fiber exposed between the only optical fiber cord terminal and the connecting mechanism moves Te can easily covered, excellent effects such as the assembly operation of the optical connector is improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an optical connector of the present invention.

FIG. 2 is a view showing a state where the optical connector of FIG. 1 is assembled, and is a front sectional view showing the vicinity of a caulking ring.

[Explanation of symbols]

1 ... Optical connector, 3 ... Ferrule, 4 ... Caulking ring (fixed part), 4a ... Fixed part (ring), 7 ... Fu
De, 11 ... connecting mechanism, 12 ... optical fiber (bare fiber), 16 ... optical fiber cord, 16a ... covering material (envelope), 17 ... optical fiber (optical fiber single fiber), 17a
… Optical fiber (bare fiber), 25… Protective tube, 2
5b ... Tip, 26 ... Retractor (C-shaped clip).

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Arikawa 1440 Rokuzaki, Sakura City, Chiba Fujikura Co., Ltd. Sakura Works (72) Inventor Masaaki Takatani 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Incorporated (72) Inventor Shinji Nagasawa 2-3-1, Otemachi, Chiyoda-ku, Tokyo Within Nippon Telegraph and Telephone Corporation (56) Reference JP 2000-9965 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/36

Claims (4)

(57) [Claims] 1. A ferrule (3) in which an optical fiber (12) is internally fixed and has a tip polished, and a ferrule (3) disposed on the rear end side facing the polished tip of the ferrule. A connecting mechanism (11) for maintaining the connection state by aligning the part protruding from the end and another optical fiber (17, 17a) for locating, butt-connecting and clamping, and covering the other optical fiber. Optical fiber cord (16) housed in (16a)
The optical connector assembled to the terminal, inserting the optical fiber to expose the optical fiber cord terminal (17, 17a) to the connection mechanism, the splicer
Extends backward from the structure, which is the opposite direction to the ferrule
The outer diameter of the optical fiber cord is larger than the outer diameter of the optical fiber exposed between the optical fiber cord end located further rearward of the hood (7) and the vicinity of the connection mechanism.
Covered with a protective tube (25) having an inner diameter, which is fixed to the optical fiber cord terminal by retrofitted possible anchor device (26) the protective tube, curved acceptable of said optical fiber in said protective tube
Optical connector (1) characterized by being 2. The protective tube tip (25b) arranged near the connecting mechanism is fixed by being sandwiched between fixing parts (4, 4a) arranged near the connecting mechanism. Optical connector. 3. The protective tube is insertable outside the optical fiber cord, and is movable in the longitudinal direction of the optical fiber cord before being fixed. Optical connector. 4. The optical fiber in the protective tube.
Secure the slack in the optical fiber exposed at the cord end
It is stored by storing in any one of claims 1 to 3.
The optical connector described.