JPH0894878A - Fiber optic connector - Google Patents

Abstract

(57) [Abstract] [Purpose] The optical fiber and the member connected to the lens unit side can be formed by accurately aligning them concentrically, and the high-power laser light can be reliably focused on the end face of the optical fiber. The optical fiber connector can be surely prevented from being heated or burned, and the structure is simple and the assembly is easy. (EN) Provided is an optical fiber connector capable of completely eliminating the alignment with the lens unit side when the optical fiber is replaced after the alignment with the side. [Structure] Optical fiber 11 from which coating material 14 is removed
A cylindrical ceramic ferrule 16 having a central shaft hole 17 having an inner diameter that allows the optical fiber 11 to be concentrically inserted according to the outer diameter of the connector and an outer peripheral surface concentric with the central shaft hole 17, It is characterized in that it is formed by projecting a predetermined length from 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connector, and more particularly to an optical fiber connector suitable for an end portion of an optical fiber used for transmitting high power laser light.

[0002]

2. Description of the Related Art Generally, in order to perform cutting, soldering, welding, etc. with a high-power laser beam, a high-power laser beam emitted from a laser beam generator 1 is incident on a lens unit as shown in FIG. It is made to be incident on the optical fiber 3 by 2 and transmitted to the processing side, and the high power laser light is irradiated from this optical fiber 3 through the lens unit 4 on the emitting side onto the workpiece 5 to perform a predetermined processing. . The high-power laser light from the incident-side lens unit 2 is focused on the end face of the optical fiber 3, and the reflected laser light reflected from the workpiece 5 is the exit-side lens. The other end surface of the optical fiber 3 is focused through the unit 4.

The lens units 2 and 4 and the optical fiber 3
Conventionally, in order to connect to each other, optical fiber connectors 6 as shown in FIG. 5 have been formed at both ends of the optical fiber 3.

That is, the optical fiber 3 is formed of a core of the central axis portion and a clad outside thereof, and is coated with a coating material 3a to form an optical fiber cable 3b. The optical fiber 3 is in a state where the coating material 3a is removed at the end portion. A fiber guide 7 is concentrically integrally bonded to the outside of the ends of the optical fiber 3 and the optical fiber cable 3b, and all of them are inserted together in a metal protective sleeve 8. Then, the grip claws 9a, 9a formed in the circumferential direction at the inner end of the protective sleeve 8 are divided into three equal parts, and the cap nut body 10 is screwed into the taper screw part 9 formed at the outer peripheral portion thereof. The protective sleeve 8 is concentrically attached to the optical fiber 3 by flexing it inward and tightening the fiber guide 7. Each lens unit side is formed so as to be spigot-connected to the outer peripheral surface 8a of the tip portion of the protective sleeve 8.

[0005]

However, since the manufacturing accuracy of the outer diameter of the optical fiber 3 is ± 5%, the concentricity between the optical fiber 3 and the fiber guide 7 also has an error of ± several%. In the conventional example in which the protective sleeve 8 is concentrically attached to the guide 7, the degree of concentricity between the protective sleeve 8 and the optical fiber 3 also has an error of ± several percent. Therefore, the central axis of each lens unit and the optical fiber 3 connected with the outer peripheral surface 8a of the tip portion of the protective sleeve 8 as a reference for the spigot connection is deviated, and the high power laser light is emitted from the end surface of the optical fiber 3. There is an inconvenience that an end face of the optical fiber 3 and an adhesive agent are burned by being incident on a place other than the above.

The present invention has been made in view of these points, and it is possible to form the optical fiber and the member connected to the lens unit side accurately and concentrically and to form a high power laser beam. Can be surely focused on the end face of the optical fiber, and it is possible to reliably prevent the members constituting the optical fiber connector from being heated or burnt out, and the structure is simple, and the assembly is easy. It is also easy to provide an optical fiber connector capable of completely eliminating the need for alignment with the lens unit side when the optical fiber is exchanged after once aligning with the lens unit side. To do.

[0007]

In order to achieve the above object, the optical fiber connector of the present invention has an inner diameter that allows the optical fiber to be concentrically inserted according to the outer diameter of the optical fiber from which the covering material has been removed. And a cylindrical ferrule made of ceramics, which has a central axis hole having an outer peripheral surface concentric with the central axis hole, and is formed to protrude from the connector body by a predetermined length.

[0008]

According to the present invention, the optical fiber is inserted into the optical fiber connector having the ferrule in which the central axis hole corresponding to the outer diameter of the optical fiber from which the coating material has been removed is bored, thereby automatically The optical fiber and the outer peripheral surface of the ferrule are aligned coaxially.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

1 to 3 show one embodiment of the optical fiber connector of the present invention.

FIG. 1 and FIG. 2 show an optical fiber 1 of the central axis portion.
1 shows the state in which the optical fiber connector 12 of this embodiment is attached to one end portion, and FIG. 3 shows only the optical fiber connector 12.

The optical fiber 11 is formed of a core at the center and a clad outside thereof, and the outside thereof is covered with a covering material 14 to form an optical fiber cable 13.

The optical fiber connector 12 is mainly a connector body 15 in which the portion of the optical fiber cable 13 that covers the optical fiber 11 with the coating material 14 is installed.
And the ferrule 16 in which the optical fiber 12 from which the coating material 14 has been removed is installed.

One ferrule 16 is made of ceramics and is formed in a relatively long cylindrical shape having an outer peripheral surface 18 concentric with the central shaft hole 17. The ferrule 16 in this embodiment is formed of opaque zirconia, alumina or mica-based ceramics such as macerite (trade name of Mitsui Mining and Materials Co., Ltd.). Since this ferrule 16 is made of ceramics, it can be manufactured with high manufacturing accuracy. For example, the central shaft hole 17 and the outer peripheral surface 1 can be manufactured.
The concentricity of 8 has an accuracy of several μ units, and the inner diameter of the central shaft hole 17 and the outer diameter of the outer peripheral surface 18 each have an accuracy of several μ units. In the present embodiment, only by inserting the optical fiber 11 into the central axis hole 17 of the ferrule 16 having high dimensional accuracy, the outer peripheral surface 18 of the ferrule 16 and the optical fiber 11 are automatically aligned concentrically. It is what makes me. On the other hand, the manufacturing accuracy of the outer diameter of the optical fiber 11 itself, which is composed of the central core and the outer cladding, is ± 5.
%, For example, in the optical fiber 11 having a nominal outer diameter of 500 μm, the actual outer diameter is 475 μm to 5 μm.
It becomes a wide range of 25 μm, and there are cases where μ-order concentric alignment is impossible. Therefore, in the present embodiment, as the ferrule 16, the dimensional error range of the outer diameter of the optical fiber 11 is equally divided into a plurality of parts, and a central axis having a nominal inner diameter equal to the nominal outer diameter at the center of each divided range. Hole 17
A plurality of types of ferrules 16 formed by drilling are prepared, and the ferrule 16 having the central axis hole 17 having the inner diameter dimension corresponding to the actual outer diameter dimension of the optical fiber 11 is made to correspond. . A large diameter portion 17a is formed at the tip of the central shaft hole 17 of the ferrule 16.

The other connector body 15 is provided with a metallic protective sleeve 19 into which the ferrule 16 is projected at a predetermined length and fitted therein, and an outer side of the protective sleeve 19 which is axially movable and rotatable. hand,
It is formed by a fixed cylinder 20 or the like in which a female screw portion 20a that is screwed with a fixed cylinder (not shown) on the lens unit side is formed. More specifically, the protective sleeve 19 is formed in a substantially pipe shape, and has a rear end portion 21a of the central shaft hole 21.
Is an optical fiber cable 1 in which the covering material 14 is not removed
The size is such that three parts can be inserted, and the intermediate part 21b
Has a size into which the optical fiber 11 from which the coating material 14 has been removed can be inserted, and the distal end portion 21c has a size into which the ceramic ferrule 16 is press-fitted. In addition, an engaging projection 22 is provided on the tip end surface of the protective sleeve 19 so as to be connected to the lens unit so as not to rotate relative to the lens unit. A compression spring 24 is interposed between the stepped portion 23 on the outer circumference of the protective sleeve 19 and the fixed cylinder 20.

Next, the operation of this embodiment will be described.

First, the outer diameter of the optical fiber 11 from which the coating material 14 has been removed is measured, and the inner diameter of the central axis hole 17 of the ferrule 16 fixed to the connector body 15 is determined as the optical fiber 1.
Optical fiber connector 12 corresponding to the actual outer diameter of 1
Select and prepare.

Next, the adhesive 25 is applied only to the outer peripheral surface of the optical fiber cable 13 of the optical fiber 11, and the protective sleeve 19 of the prepared hollow optical fiber connector 12 is applied.
The optical fiber 11 is inserted into the central axis hole 21 from the rear end 21a side. At this time, the optical fiber 11 from which the coating material 14 has been removed penetrates the central axis hole 21 of the protective sleeve 19 and is then gradually inserted into the central axis hole 17 of the ferrule 16. The tip of the covering material 14 of the optical fiber cable 13 is inserted until it comes into contact with the front end of the rear end portion 21a of the central shaft hole 21 of the protective sleeve 19, and the covering material 14 of the optical fiber cable 13 is held with the adhesive 25.
And the protective sleeve 19 are bonded.

In this way, in this embodiment, the optical fiber 11 from which the coating material 14 has been removed is inserted into the central axis hole 17 of the ferrule 16, so that the central axis hole 17 inserts the optical fiber 11 concentrically. Because of the narrow inner diameter, the optical fiber 11 and the outer peripheral surface 18 of the ferrule 16 are automatically and reliably aligned concentrically. This concentric positioning operation is extremely simple compared to the conventional example. Moreover, the structure is simple, the optical fiber connector 12 itself can be easily assembled, and the cost is low.

Further, in the optical fiber 11 and the optical fiber connector 12 assembled in this way, the connecting cylinder on the lens unit side is spigot-connected to the outer peripheral surface 18 of the ferrule 16 and engaged with the engaging projection 22. The mating recesses are engaged with each other so that they are aligned with each other, and the mutual fixed cylinders 20
It is fixedly connected so that it will not be displaced. At this time, since the optical fiber 11 and the outer peripheral surface 18 of the ferrule 16 are aligned concentrically, the lens unit side and the optical fiber 11 may be aligned once, and the optical fiber 11 thereafter. When replacing, the alignment can be omitted. Therefore, on the incident side and the emitting side of the optical fiber 11, the high-power laser light can always be accurately focused on the end face of the optical fiber 11, and the end face of the optical fiber 11 is reliably prevented from being burnt out.

Further, for example, the optical fiber 11 and the ferrule 1
Even if high-power laser light is incident on the inner surface of the central axis hole 17 of No. 6, since the central axis hole 17 is relatively long, it is diffused while traveling between the two, and the covering material 14
The part is also prevented from being burnt out.

Although the optical fiber 11 and the inner surface of the central axis hole 17 of the ferrule 16 are not adhered to each other in the above embodiment, they may be adhered to each other if high power laser light is not incident between them. You may

Further, the present invention is not limited to the above embodiment, but can be modified as necessary.

[0024]

As described above, since the optical fiber connector of the present invention is constructed and operates, it is possible to form the optical fiber and the ferrule connected to the lens unit side by accurately aligning them concentrically. It is possible to surely focus the high-power laser light on the end face of the optical fiber, and it is possible to reliably prevent the members constituting the optical fiber connector from being heated or burned. Is simple and easy to assemble, and it is possible to completely eliminate the need for alignment with the lens unit side when the optical fiber is replaced after once aligning with the lens unit side. Play.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which an optical fiber is attached to one embodiment of an optical fiber connector of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a sectional view showing an embodiment of the optical fiber connector of the present invention.

FIG. 4 is a schematic configuration diagram showing an outline of a processing system using an optical fiber.

FIG. 5 is a sectional view showing an example of a conventional optical fiber connector.

[Explanation of symbols]

 11 optical fiber 12 optical fiber connector 14 coating material 15 connector body 16 ferrule 17 center axis hole 18 outer peripheral surface

Claims (1)

[Claims] 1. A cylinder having a central shaft hole having an inner diameter that allows the optical fiber to be concentrically inserted according to the outer diameter of the optical fiber from which the coating material has been removed, and an outer peripheral surface concentric with the central shaft hole. An optical fiber connector, characterized in that a ferrule made of ceramics is formed by protruding a predetermined length from the connector body.