JP2001235657A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent exposure of an optical fiber near an optical connector, at the assembly of the optical connector equipped with a ferrule with the tip end ground, in which an optical fiber is preliminarily internally loaded and fixed and equipped with a connecting mechanism in which the optical fiber projecting from the ferrule is butt-connected to an optical fiber exposed at the end part of an optical fiber cord. SOLUTION: The optical connector 1 is constituted such that the optical fiber 17 exposed at the end part of the optical fiber cord 16 is inserted into the connecting mechanism 11 for connecting to an optical fiber on the ferrule side, that the optical fiber 17 exposed in-between the end part of the optical fiber cord 16 and near the connecting mechanism 11 is conversed with a protective tube 25, and that the protective tube 25 is fixed to the end part of the optical fiber cord 16 by means of a anchor 26 attachable later.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector which terminates optical fiber cords so that they can be connected to each other.

[0002]

2. Description of the Related Art Conventionally, on-site optical connectors for terminating an optical fiber connector at a connection site other than a factory have been proposed. Accordingly, various types of on-site SC optical connectors 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 into a ferrule having a polished tip so that a connector polishing operation after connection is omitted. For the connection work between the SC type optical connector and the optical fiber other than for the on-site installation, the optical fiber is inserted into all the connector housing parts such as rubber boots in advance, and after connecting the tip of the optical fiber to the SC ferrule. This was a step of polishing the connector tip and assembling the entire connector.

[0003]

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

[0004] In view of the above problems, the present applicant has filed Japanese Patent Application No.
An optical connector described in Japanese Patent Application No. 5875 and Japanese Patent Application No. 9-5876 has already been filed. These optical connectors are configured to include a ferrule of an SC type optical connector in which an optical fiber is inserted in advance, and a mechanical splice type connection mechanism for connecting an optical fiber protruding from the ferrule to another optical fiber. . To attach the optical connector to the optical fiber cord, the optical fiber exposed at the end of the optical fiber cord is inserted into a connection mechanism and connected to the optical fiber on the ferrule side.

Incidentally, since the optical fiber cord terminal is not inserted into the connection mechanism, there is generally an optical fiber which is not inserted into the connection mechanism and is exposed near the optical connector. There is a problem that it is easily damaged. For example, JIS C 5973
When the same exposure length as when directly inserted into a ferrule is secured to the optical fiber of the optical fiber cord terminal, as in the case of a standard SC optical connector stipulated in Japan, only the length equivalent to the dimensions of the ferrule and connection mechanism Since the optical fiber cord terminal is far from the ferrule, the optical fiber cannot be stored in the standard optical connector. In addition, if the length of the exposed optical fiber of the optical fiber cord terminal is reduced, the length of the strength member that is pulled out from the optical fiber cord terminal together with the optical fiber may be insufficient, and the optical fiber cord may not be fixed to the optical connector. The process of exposing an optical fiber or a tensile member from an optical fiber cord terminal is generally standardized in accordance with a standard SC type optical connector, and if this process is changed, reduction in manufacturing efficiency and cost will occur. Will lead to a rise.

The present invention has been made in view of the above-mentioned problems, and (1) protects an optical fiber exposed between an optical fiber cord terminal and the vicinity of a connection mechanism of an optical connector assembled to the optical fiber cord terminal. The optical characteristics can be maintained by storing and protecting the inside of the tube. (2) Moreover, the protection tube can be easily and quickly fastened to the optical fiber cord by a fastening tool that can be retrofitted.
(3) An object of the present invention is to provide an optical connector that can easily cover a protective tube from an optical fiber cord terminal to an optical fiber near a connection mechanism simply by moving the protective tube in the longitudinal direction of the optical fiber cord. It 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 the optical fiber is internally fixed and the tip of the ferrule is polished, and a portion which is disposed on the rear end side opposite to the polished tip of the ferrule and protrudes from the rear end of the ferrule of the optical fiber And a connection mechanism for maintaining the connection state by positioning and aligning the other optical fiber and butt-connecting and clamping, and assembling the terminal of the optical fiber cord in which the another optical fiber is housed in a coating material. An optical connector, the optical fiber exposed to the optical fiber cord terminal is inserted into the connection mechanism, covering the optical fiber exposed from the optical fiber cord terminal to the vicinity of the connection mechanism with a protective tube, An optical connector characterized in that the protective tube is fixed to the optical fiber cord terminal by a fastening tool that can be retrofitted. It was determined means.

The protective tube is preferably made of a flexible material, so that the optical fiber covered with the protective tube can be efficiently protected. Further, since the protective tube is fixed to the optical fiber cord terminal by the anchoring tool, the state of protection of the optical fiber by the protective tube can always be maintained in a good condition, and the optical characteristics of the optical fiber can be maintained for a long time. The protective tube has a length that accommodates all or a part of the optical fiber exposed between the connection mechanism and the optical fiber cord terminal. Since the fastening tool can be retrofitted, the protection tube can be fixed at an appropriate position. After inserting the optical fiber of the optical fiber cord into the connection mechanism, the protective tube covers the exposed optical fiber between the connection mechanism and the optical fiber cord terminal. The protective tube need not cover the entire length of the optical fiber exposed to the optical fiber cord terminal from the connection mechanism, but it is more preferable to cover the protective tube with a longer dimension. The storage length of the optical fiber by the protective tube can be easily adjusted by the fixing position of the protective tube to the optical fiber cord terminal. Since the retaining tool is retrofitted, it can easily correspond to the position where the protective tube is fixed to the optical fiber cord terminal.

Further, in the present invention, as described in claim 2,
It is more preferable to adopt a configuration in which the distal end of the protective tube disposed near the connection mechanism is fixed by being sandwiched between fixed components disposed 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 is applicable to a multi-core optical fiber cord in addition to a single-core optical fiber cord. In an optical connector corresponding to a multi-core optical fiber cord, a multi-core ferrule and a connection mechanism are adopted.

According to a third aspect of the present invention, there is provided a structure in which the protective tube is insertable outside the optical fiber cord and is movable in the longitudinal direction of the optical fiber cord before fixing. 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, and after the optical fiber exposed to the optical fiber cord terminal is inserted into the connection mechanism, 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 to the optical fiber cord terminal into the connection mechanism, the protective tube can be moved to a position separated from the optical fiber cord terminal, so that the protective tube does not interfere with the work of inserting the optical fiber into the connection mechanism. 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 a protective tube,
All that is required is to move the protective tube along the optical fiber cord to house the optical fiber. At this time, the storage length of the optical fiber depends on the position where the protective tube is fixed to the optical fiber cord. Since the protective tube is fixed to the optical fiber cord by a post-installable anchor, it is possible to easily correspond to the fixing position.

[0011]

FIG. 1 shows an optical connector 1 according to one embodiment of the present invention. In the figure, reference numeral 2 denotes a frame, 3 denotes a ferrule, 4 denotes a caulking ring, 4a denotes a ring, 5 denotes a spring, 6 denotes a stop ring, 7 denotes a boot, and 8 denotes a knob. The ferrule 3 is applied to an optical connector defined by JIS C 5973, and includes a ferrule body 9 to which an optical fiber is internally fixed and a ferrule body 9
, And a connection mechanism 11. An optical fiber 12 (bare fiber) is inserted and fixed in the ferrule main body 9 in advance, and the distal end surface 13 of the ferrule main body 9 is polished such as PC (Physical Contact) polishing.

The connection mechanism 11 is installed behind the ferrule hold 10 (on the rear side in FIG. 1).
The connection mechanism 11 includes a split rod-shaped element 14 and a C-shaped spring 15 having a C-shaped cross section mounted on the outside of the element 14. The element 14 has an aligning groove (not shown) such as a V-groove or a U-groove therein. The optical fiber 12 inserted and aligned in the aligning groove is internally moved by the clamping force of the C-shaped spring 15. To be clamped. An optical fiber 17 (single-core optical fiber), which is obtained by removing a coating material 16a (jacket) of an optical fiber cord 16 at the rear end in the longitudinal direction of the element 14 (the back side of the paper surface in FIG. 1), is aligned. An optical fiber introduction part 18 for introducing the light into the groove is provided.

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

On the side of the element 14, a wedge insertion groove 20 for inserting a wedge 19 for opening the element 14 is formed, and the opening 21 of the C-shaped spring 15 matches the wedge insertion groove 20. . The assembled optical connector 1 further includes a connection mechanism 1
The wedge insertion opening 22 opened on the side surface of the stop ring 6 for accommodating the wedge 1 corresponds to 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 swaging ring 4 is
Tensile strength member 23 exposed at the end of optical fiber cord 16
(Kevlar) is caulked between the stop ring 6 and fixed.
Furthermore, the covering material 16a is caulked and fixed between the ring 4a. The spring 5 is inserted into the stop ring 6, and presses the element 14 to urge the ferrule 3 forward (to the left in FIG. 2). As shown in FIG. 1, the protrusion of the ferrule 3 from the frame 2 is restricted by the engagement of the flange portion 24 of the ferrule hold 10 with the frame 2.

In FIG. 1, reference numeral 25 denotes a protective tube. In FIG. 1, the protective 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 (the direction of arrow A in FIG. 1). The protective tube 25 is formed of a flexible material such as a synthetic resin, and can protect the optical fiber cord 16 and the optical fiber 17 housed therein so as not to be damaged.

In FIG. 1, reference numeral 26 denotes a retaining tool (C-shaped clip).
It is. The retainer 26 is formed of an elastic material such as plastic and has a C-shaped cross section.
5 is fitted from the outside to the boot 27 fixed to the rear end 25a (the right rear part in FIG. 1) of the boot 27 by bonding or the like.
At an appropriate position of the optical fiber cord 16. For example, for an optical fiber cord having an outer diameter of 1.5 mm, a protection tube 25 having a boot having an outer diameter of 2.35 mm is adopted, and a C-shaped clip having an inner diameter of 2.0 mm is applied.

In FIG. 2, an optical fiber 17 exposed at an end of an optical fiber cord 16 is inserted into an element 14 from an optical fiber introducing portion 18. The optical fiber cord 16 terminal is located behind the hood 7 of the optical connector 1 (right side in FIG. 2). The optical fiber 17 has an exposure length of about several tens mm from the element 14 to the end of the optical fiber cord 16. The optical fiber 17 exposed from the end of the optical fiber cord 16 to 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 to the vicinity of the end of the optical fiber cord 16 by an anchor 26. On the other hand, the distal end 25b of the protection tube 25 is expanded and arranged outside the caulking ring 4, and is fixed so as to be sandwiched between the caulking ring 4 and the ring 4a caulked from the outside. This allows
Since the protection tube 25 is supported at a fixed position in the optical connector 1 and vibrations and the like are prevented, the optical fiber 17 is stably stored in the protection 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.

Since the bending of the optical fiber 17 is allowed in the protection tube 25, for example, if the loosened optical fiber 17 is housed in the protection tube 25, the optical fiber 17 is not affected even if tension is applied to the tensile strength member 23. 17 can be prevented from acting on tension. In this case, even if a sufficient slack is secured in the optical fiber 17, the optical fiber 17 does not protrude outward from the protective tube 25, so that the optical fiber 17 can be prevented from interfering with surrounding members,
The optical characteristics of the optical fiber 17 can be maintained.

An optical fiber 1 is placed in the protective tube 25.
7, a tensile strength member 23 is also stored. The tensile member 23 is drawn into the caulking ring 4 from the protection tube tip 25b. Since the protection tube tip 25b is fixed outside the caulking ring 4, it does not interfere with the strength member 23 caulked and fixed between the stop ring 6 and the caulking ring 4 mounted outside 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 through 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 is inserted into the element 14 via the connector 8 and butt-connected to the optical fiber 12 on the ferrule 3 side in the connection mechanism 11.
At this time, the protection tube 25 is disposed at a position separated from the end of the optical fiber cord 16 (right side of arrow A in FIG. 1). Thereby, it is possible to prevent the protection tube 25 from interfering with the operation of inserting the optical fiber 17 into the element 14, and the insertion workability and the connection workability are improved.

Next, as shown in FIG. 2, the strength member 23 is fixed by the caulking ring 4 attached to the outside of the stop ring 6.
And fix it. Next, the protection tube 25 is moved in the direction of the stop ring 6, and the caulking ring 4 having been fixed is completed.
The protection tube tip 25b is fixed by caulking and fixing the ring 4a from the outside. Thereby, the optical fiber 17 and the tensile member 2
3 is stored in the protection tube 25.

In the process of assembling the optical connector 1, when 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
It is possible to prevent the optical fiber 17 from interfering with the fixing work, etc., so that the assembling work can proceed efficiently without damaging the optical fiber 17. Needless to say, when the protection tube 25 obstructs the work, the protection tube 25 is retracted in a 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 other portion is stored and protected in the protective tube 25 except for the insertion length at the tip of the optical fiber 17, and then the optical fiber 17 is removed. When the element 17 is inserted into the element 14, it is possible to prevent the optical fiber 17 from being suddenly bent or the like during the insertion operation. Also, at this time,
Since the distal end of the optical fiber 17 is exposed at the distal end of the protective tube 25, there is no fear that the workability of inserting the optical fiber 17 into the connection mechanism 11 is impaired.

When the crimping of the tensile member 23 and the protection tube tip 25b is completed, the boot 2 is
7 is fixed to the optical fiber cord 16 terminal, and the optical connector 1
Assemble. Since the anchor 26 can be retrofitted, it is easy to fix the boot 27 at an appropriate position at the end of the optical fiber cord 16. Since the fixing position of the boot 27 at the terminal of the optical fiber cord 16 has a large degree of freedom, only by adjusting the fixing position of the boot 27 at the terminal of the optical fiber cord 16, the optical fiber from the terminal of the optical fiber cord 16 to the caulking ring 4 is adjusted. 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 stored and protected in the protective tube 25, and the optical characteristics of the optical fiber 17 can be reliably maintained. In addition, since the optical fiber 17 can be stored and protected by the protective tube 25 even during the assembling work of the optical connector 1, the workability of assembling the optical connector 1 is improved and the assembled optical connector 1 has desired optical characteristics. Can be obtained reliably.

The optical connector of the present invention is not limited to the above-described embodiment. For example, it is possible to employ a retaining tool or a fixed component whose design has been changed. A configuration other than the caulking ring 4 and the ring 4a can be adopted as the fixed component.

[0028]

As described above, according to the optical connector of the present invention, the following excellent effects can be obtained. (B) The optical fiber exposed from the optical fiber cord terminal was inserted into the connection mechanism, and the optical fiber exposed from the optical fiber cord terminal to the vicinity of the connection mechanism was covered with a protective tube and stored and protected. Can be stably maintained over a long period of time. (B) Since the protective tube is fixed to the optical fiber cord terminal by a post-installable anchor, the fixing operation is easy, and the fixing operation can be performed without interfering with the assembling operation of other parts of the optical connector. As a result, the workability of assembling the optical connector is improved. (C) By adjusting the mounting position of the protective tube to the optical fiber cord terminal, it is possible to easily cope with the length of the optical fiber exposed between the optical fiber cord terminal and the vicinity of the connection mechanism. The storage workability is improved.

According to a second aspect of the present invention, when the tip of the protective tube arranged near the connection mechanism is fixed by sandwiching it between fixed parts arranged near the connection mechanism, The optical fiber is stably supported at a predetermined position in the optical connector, and the optical fiber can be stably stored in the protective tube. (E) (D), the optical characteristics of the optical fiber can be more reliably maintained, The assembled optical connector has an excellent effect that the intended optical loss can be maintained for a long time.

According to a third aspect of the present invention, when the protective tube is configured to be insertable outside the optical fiber cord and to be movable in the longitudinal direction of the optical fiber cord before being fixed, (F) When inserting the optical fiber exposed to the optical fiber cord terminal into the connecting mechanism, the protective tube can be moved to a position away from the optical fiber cord terminal, so that the protective tube interferes with the work of inserting the optical fiber into the connecting mechanism. (G) Inserting the protective tube into the optical fiber cord prevents inconveniences such as dropping during the assembly of the optical connector. (H) 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 the drawings]

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

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical connector, 3 ... Ferrule, 4 ... Caulking ring (fixed part), 4a ... Fixed part (ring), 11 ... Connection mechanism, 12 ... Optical fiber (bare fiber), 16 ... Optical fiber cord, 16a ... Coating material (Coat), 17: Optical fiber (single optical fiber), 17a: Optical fiber (bare fiber), 25: Protective tube, 25b: Tip, 26: Retainer (C-shaped clip).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Tamaki 1440 Mutsuzaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Office Co., Ltd. 72) Inventor Masaaki Takaya 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Shinji Nagasawa 3-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Stock Company F-term (reference) 2H036 KA02 LA03 NA01 PA02 QA12 QA24 QA29 QA45 QA56

Claims (3)

[Claims] 1. A ferrule (3) having an optical fiber (12) internally fixed and polished at a tip thereof, and a ferrule (3) disposed at a rear end side of the ferrule facing the polished tip of the optical fiber, the ferrule being disposed after the ferrule of the optical fiber. A connection mechanism (11) for positioning and aligning a portion protruding from the end with another optical fiber (17, 17a) to maintain a connected state by butt-connecting and clamping, and covering the another optical fiber with a coating material; Optical fiber cord (16) housed in (16a)
The optical fiber (17, 17a) exposed to the optical fiber cord terminal is inserted into the connection mechanism, and is exposed between the optical fiber cord terminal and the vicinity of the connection mechanism. An optical connector (1), characterized in that a protective tube (25) is put on the optical fiber thus obtained, and the protective tube is fixed to the optical fiber cord terminal by a fastening tool (26) that can be retrofitted. 2. The protection tube tip (25b) arranged near the connection mechanism is fixed by being sandwiched between fixing parts (4, 4a) arranged near the connection mechanism. Optical connector. 3. The optical fiber cord according to claim 1, wherein the protective tube is insertable outside the optical fiber cord, and is movable in a longitudinal direction of the optical fiber cord before fixing. Optical connector.