JPS58143309A - Optical fiber connector - Google Patents

Abstract

PURPOSE:To align the axial centers of optical fibers to each other with good accuracy, by forming a guide cylinder in such a way that the outside circumferential surfce thereof guides needless and that the guide cylinder is thus inserted. CONSTITUTION:This aligning sleeve 31 consists of a cylindrical body 35 consisting of an elastic material such as rubber or plastics and three pieces of metallic needles 36. The needles 36 are embedded in the body 35 respectively in parallel with the axis of said body in such a way that part of the outside circumferential surfaces thereof project to the inside wall surface of the body 35, and in the positions where the circumferential direction is trisected. The outside diameter of the body 35 is formed roughly equal to the inside diameter of the holes drilled in the axial central parts of receptacle members 32, 33. The inside diameter of the body 35 is formed larger than the outside diameter of a guide cylinder 13 and is so formed that the diameter of the imaginary circle in contact with the projecting surfaces of the needles 36 is equal to the outside diameter of the cylinder 13 or slightly smaller than said outside diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber connector, and particularly relates to an improved alignment sleeve for aligning the optical axes of optical fibers by abutting the distal ends of the optical fibers against each other. Many connectors with similar configurations to electrical coaxial connectors are used.

That is, the optical fiber 11a having the protective liquid 112a is connected to the bushing tube integrated with the plug member 14, and the rubber coating 1 fitted into the coupling end of the bushing 16.
8 and from which the protective coating has been removed is biased toward the coupled end under the action of a spring 15, and is slid by the guide tube 13 which can be moved toward the non-coupled end by pressing the end. freely supported.

Furthermore, screws 17 are attached to the outer peripheral portion of the plug member 14, and these constitute a plug 10 for joining optical fibers.

A protective liquid 1112 to which this optical fiber 11a is to be joined
The optical fiber 11b having a diameter of 1.b is also held by a plug 20 having a similar configuration.

On the other hand, for tightening, a screw that engages with the screw 17 is provided on the outer periphery.
An alignment sleeve 31 that fits into the guide tube 13 is attached to the axial center of the receptacle members 32 and 33 whose flange portions are mutually fastened by machine screws 34, and these constitute the receptacle 30.

Thus, plugs 10 and 20 are placed at both ends of receptacle 30.
When the plugs are connected, the tips of the guide tubes 13 of each plug are inserted into the alignment sleeve 31, and at the same time they are butted against each other, the optical fibers 11 are also butted against each other,
As a result, the optical fibers 11 are optically coupled.

Note that when connecting the plugs 10 and 20 to the receptacle 30, the plug member 14 has an annular convex portion and the receptacle members 32 and 33 have an annular concave portion so that the rotational force of the tightening screw 17 does not act on the optical fiber 11. They are provided respectively and fitted together.

Generally, the main function of an optical fiber connector is to hold a pair of optical fibers so that their optical axes are correctly aligned. The inner diameter of the tube 13, the outer diameter of the guide tube 13, and the inner diameter of the alignment sleeve 31 are finished in such a manner that they fit together without any gaps.

As shown in the enlarged cross-section in FIG.
Air is trapped in the internal space 31a of 1, and a complete connection cannot be achieved until this air leaks outside.

One way to solve this problem is to provide a crack groove 31b in the alignment sleeve 31 as shown in FIG. 3, and allow the internal air to escape from there. It is clear that this affects the accuracy of the inner diameter, and furthermore, forming the crack groove 31b was itself a fairly difficult task.

The present invention has been made in order to eliminate the drawbacks of the conventional ones described above, and when inserting the guide tubes that hold the optical fibers at the axial center from both open ends of the alignment sleeve, the air inside the alignment sleeve is removed. It is an object of the present invention to provide an optical fiber connector that can be easily released to the outside, is easy to manufacture, and can align the axes of optical fibers with each other with high precision.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 4 is a perspective view showing the structure of an alignment sleeve of an optical fiber connector according to the present invention, and FIGS. 5(a) and 5(b) are a side view and a longitudinal cross-sectional view of this alignment sleeve.

This alignment sleeve includes a cylindrical body 35 made of an elastic material such as rubber or plastic, and three metal needles 36.
These needles 36 each have a cylindrical body 35.
The cylindrical body 35 is parallel to the axis of the cylindrical body 35 and a part of its outer circumferential surface protrudes from the inner wall surface of the cylindrical body 35, and is implanted at a position dividing the circumferential direction into three equal parts.

In addition, the outer diameter of the cylindrical body 35 as well as the receptacle member 3
2 and 33 (FIG. 1), the inner diameter of this cylindrical body 35 is larger than the outer diameter of the guide tube 13, and this cylindrical body body 35
The diameter of the virtual circle in contact with the protruding surface of the needle 36 implanted in the inner wall □ of the guide I! 113, or is formed to be slightly smaller than this outer diameter.

On the other hand, the needle 36 is longer than the length in the axial direction of the cylindrical body 35 by an amount corresponding to its diameter, and its end surface is machined into a hemispherical shape and protrudes equally from both end surfaces of the cylindrical body 35.

FIGS. 6(a) and 6(b) are a side view and a vertical cross-sectional view of the guide tube 13 inserted into this alignment sleeve.
3 is in line contact with each of the three needles 36.
A space W is formed between the outer circumferential surface of the guide tube 13 and the inner wall surface of the cylindrical body 35, which are supported from one side to the other. That is, this space W allows the air inside the alignment sleeve to escape easily to the outside.

In addition, the cylindrical body 35 is made of an elastic material, and the diameter of the virtual circle in contact with the protruding surface of the needle 36 is set to the diameter of the guide cylinder 13.
By making the outer diameter slightly smaller than the outer diameter of the guide tube 13, when the guide tube 13 is inserted here, the needle 36 is pushed open radially outward, and at the same time, the guide tube 13, once inserted, is pushed radially inward. become. As a result, the outer diameters of the guide tubes 13 that are butted against each other are maintained under substantially equal conditions.

Therefore, by processing the outer diameters of the mutually coupled guide tubes 13 with emphasis on making them equal, or by simply selecting guide tubes with similar outer diameters, the optical fiber 1
1a and 111) can be correctly aligned.

That is, in conventional optical fiber connectors, the optical axes could not be aligned correctly unless the absolute accuracy of the outer diameter of the guide tube 13 and the inner diameter of the alignment sleeve was improved, but here, the cylindrical body 35 is made of an elastic material, and the diameter of the virtual circle in contact with the protruding surface of the needle 36 is determined by the guide cylinder 1.
By making the outer diameter somewhat smaller than No. 3, the optical axes can be easily aligned.

On the other hand, since the diameter of the virtual circle in contact with the protruding surface of the needle 36 is made smaller than the outer diameter of the guide tube 13, the guide tube 1
In order to solve this problem, the end of the needle is formed into a hemispherical shape.

Here, it is necessary to select a needle 36 that has excellent abrasion resistance and is resistant to oxidation. In this sense, stainless steel wire is suitable, and if it is in a place where there is no risk of rust, hardened piano wire may also be used. good.

In the above embodiment, plastic or rubber is used as the cylindrical body 35, but any material other than these may be used as long as it has elasticity. The needle 36 that is
It goes without saying that the position is not limited to the equally divided position, but any other position may be used as long as the guides and the dowels 13 abutting each other at an angle can be obtained under approximately equal conditions.

Furthermore, in the above embodiment, the inner wall surface of the cylindrical body 35 is formed into a circular shape, but other shapes may be used as long as the needle 36 can be implanted in a predetermined position and the internal air can be easily released to the outside. It may be a shape.

As is clear from the above description, according to the optical fiber connector of the present invention, air within the alignment sleeve can be easily released to the outside, and the alignment sleeve is composed of a plurality of needles and a cylindrical body made of an elastic material. In view of this, it is possible to form the connector using a mold, and compared to conventional optical fiber connectors, the number of high-precision processing steps can be significantly reduced.

In addition, since the alignment sleeve is made of an elastic material, the axis of the optical fiber can be precisely aligned by simply making the diameter of the virtual circle in contact with the outer peripheral surface of the needle slightly smaller than the outer diameter of the guide tube.
The excellent effect of matching can be obtained. □

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the configuration of a conventional optical fiber connector, Fig. 2 is a partially enlarged sectional view to explain the state of this optical fiber connector when it is connected, and Fig. 3 is a configuration of this optical fiber connector. FIG. 4 is a perspective view showing the main component configuration of an embodiment of the optical fiber connector according to the present invention, FIGS. Figures 6(a) and 6(b) are a side view and a vertical cross-sectional view of the main parts showing the coupled state of this optical fiber connector. 10.20...Plug, 11a, 11b...
... Optical fiber, 12a, 12b ... Protective coating, 13 ... Guide tube, 14 ... Plug member, 15 ... Spring, 16 ... ...
・Bushing, 17... Tighten with screw, 18.
...Rubber coating, 30...Receptacle,
31...Alignment sleeve, 32.33...
・Receptacle member, 34...Machine screw, 35・
...Cylindrical body, 36... Needle. Patent applicant Showa Musen Kogyo Co., Ltd.-11-

Claims (1)

[Claims] 1. A plug having a guide tube that slidably supports the tip of an optical fiber in its axial direction, and an alignment sleeve having a through hole that fits into the guide tube. and a receptacle which is held at the axial center and has the plug connected to both ends so that the guide tube and the distal end surface of the optical fiber are brought into abutment in the through hole of the alignment sleeve. consists of a cylindrical body made of an elastic material and a plurality of metallic needles, and these needles are parallel to the axis of the cylindrical body, and a part of the outer peripheral surface of the needles is parallel to the axis of the cylindrical body. An optical fiber connector, characterized in that the optical fiber connector is installed on an inner wall surface so as to protrude from the inner wall surface, and is configured such that the outer circumferential surface of the guide tube guides the needle into the inner wall surface. 2. The optical fiber connector according to claim 1, wherein the needles marked # are arranged on three equal parts in the circumferential direction of the cylindrical body. 3. The optical fiber connector according to claim 1, wherein the needle protrudes from both end surfaces of the guide tube and is formed into a hemispherical shape. 4. The optical fiber connector according to claim 1, wherein the cylindrical body is made of rubber. 5. The optical fiber connector according to claim 1, wherein the cylindrical body is made of planar material.