JPH06230253A - Method for connecting and fixing optical fiber terminal - Google Patents

Abstract

PURPOSE:To lessen the mispositioning loss of the optical axes of light signals arising from a fitting gap at the time of attaching and detaching at the optical fiber terminal of a screw-fastening system in which a ferrule is inserted into a sleeve hole and connected and fixed by means of a coupling nut. CONSTITUTION:The fitting part of the ferrule 1 is provided with a mechanism of generating acting force in the direction orthogonal to axis by mounting the coupling nut 6 so that the mispositioning generated by the fitting gap is removed. The reproducibility of the fixing position by the repeating operation of the ferrule 1 in the optical fiber connector in the sleeve is improved by the simple structure. As a result, there is an effect of improving the transmission efficiency of light energy at the time of connecting the respective segments in an optical transmission circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting and fixing a ferrule of an optical fiber terminal used for an optical transmission circuit.

[0002]

14 and 15 are sectional views showing a conventional method for connecting and fixing an optical fiber terminal. FIG. 14 shows a connecting method in an optical connector and FIG. 15 shows a connecting method in an optical element module. In FIG. 14, 1 is a ferrule,
Reference numeral 2 is an optical fiber held by the ferrule 1, 3 is an adapter having a sleeve hole into which the ferrule 1 is inserted and aligned, and male threads 5 are provided at both ends, and 6 is a female thread engaging with the male thread 5. 7, a ferrule 1 is inserted into the adapter 3 from both ends, and the ferrule 1 is fastened and connected by a coupling nut 6. In addition, as another example, as shown in FIG.
The optical element 9 is incorporated at the end and the sleeve hole 4 is inserted through the lens 10.
Optical element module 8 for collecting the optical output of the optical element 9 on the end face of the optical element
There is. Also in this case, the method of inserting the ferrule 1 into the sleeve hole 4 and fastening and connecting with the coupling nut 6 is common.

Next, the operation will be described. An optical fiber is used as the transmission medium in the optical transmission circuit. When the transmission line of an optical fiber is relatively long or is connected between different devices, the transmission line is divided into a plurality of segments, and the different segments are ferrules for connecting the segments to each other. Are connected using a separate fiber optic connector having a. The main design rule for such ferrules is to minimize the loss of optical energy as the optical signal passes from the end of one segment of one transmission line to the other segment adjacent to that transmission line. It is to be. For example, in the case of an adapter for joining an optical fiber and an optical fiber, when one cross section and the other cross section are in contact with each other, that is, when the transmission lines are connected in an end-to-end relationship, two optical fiber transmission lines The transmission efficiency of light energy is maximized when the axes are correctly aligned. On the contrary, if the cross section of the transmission line, that is, the center of the end does not coincide with each other and is misaligned in the lateral direction, light energy is lost. Therefore, many ferrules and each segment are designed to be as perfect as possible in axial alignment. An example of the method used to achieve this design standard is to insert the ferrule 1 into the sleeve hole 4 as shown in FIGS. The sleeve hole 4 is designed so that the clearance between the ferrule 1 and the ferrule 1 can be reduced by using the sleeve hole 4 that has been accurately processed. Thereby, even if the ferrule 1 is repeatedly attached to and detached from the sleeve hole 4, the fixed position of the optical fiber 2 is accurately reproduced and connected.

[0004]

The conventional connection and fixing of optical fibers is generally constructed as described above, and it is caused by the gap required for attachment and detachment and the variation due to the tolerance of the sleeve hole and the ferrule. When repeatedly connected and fixed, the fixing position of the optical fiber has a problem of causing misalignment in the gap.

The present invention has been made to solve the above problems, and when each segment of an optical transmission circuit having a sleeve hole as its fitting component is fitted to a ferrule, the sleeve hole is It is an object of the present invention to provide a method for connecting and fixing an optical fiber terminal, which has a function of improving reproducibility by repeating the fixed position of a ferrule inside the device.

[0006]

According to a method of connecting and fixing an optical fiber terminal according to the present invention, a coupling nut is fastened to an adapter having a connection function between respective segments of an optical transmission circuit such as a transmitting optical module or an adapter. By doing so, a part of the wall surface of the sleeve hole is pushed down, and the ferrule is fixed to the sleeve hole.

[0007]

In the ferrule according to the present invention, the ferrule is pressed against the inner wall surface of the sleeve hole which each segment has as a fitting part in a certain direction, and the ferrule is aligned with the inner wall surface as a reference, so that a clearance required for attachment and detachment is obtained. In addition, the misalignment due to the clearance caused by the tolerance between the sleeve hole and the ferrule can be reduced, that is, the reproducibility of the fixed position of the ferrule inside the sleeve hole due to the repeated operation can be improved.

[0008]

【Example】

Embodiment 1 An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view showing a connecting portion of an optical fiber terminal according to the present invention. In the figure, 1 is a ferrule used for accurately aligning an optical fiber 2 which is an optical signal transmission medium, 3 is an adapter, and a male screw 5 engaging a coupling nut 6 and a ferrule 1 are aligned at both ends. It has a sleeve hole 4, and as shown in FIG.
Two rows of slits 11 are inserted in the axial direction, and a segment 12 sandwiched between the slits and a hole are provided in the segment 12 in the vicinity of the fitting end of the coupling nut 6, and self-tapping is performed in this hole. It has a structure in which a protrusion 13 made of a possible resin is embedded.

Next, the operation will be described. In the above-mentioned structure, the ferrule 1 is inserted into the adapter 3 from both ends, the coupling nut 6 is tightened to connect the optical fiber 2, but when the coupling nut 6 is completely tightened, the projection 13 is elastically deformed due to an incomplete screw. Then, the segment 12 is pushed down and the ferrule 1 is fixed in the sleeve hole 4 without any gap. As a result, the optical fibers 3 held by the ferrule 1 are aligned and connected and fixed with good reproducibility.

Embodiment 2 This embodiment will be described with reference to FIG. FIG. 3 is a partial cross-sectional view for explaining the gist of the present invention. As with FIG. 2, the adapter 12 is provided with the segment 12, but the threaded portion of the segment 12 is provided with a shallow valley diameter 14 in advance. There is.

Therefore, the coupling nut 6 is tightened and connected as in the above embodiment, but the coupling nut 6 is connected.
When shutting off, the shallow valley diameter 14 causes interference, and the segment 12 is pushed down and the angle A is fixed.

Although the adapter 3 is complicated by machining, it can be easily realized by integral molding of resin, and a predetermined elastic force is easily obtained, which is suitable for connection and fixation.

Embodiment 3 An embodiment of the present invention will be described with reference to FIGS. Figure 4
FIG. 3 is a sectional view showing a connecting portion of an optical fiber terminal according to the present invention. In the figure, 1 is a ferrule used for accurately aligning an optical fiber 2 which is an optical signal transmission medium, 3 is an adapter, and coupling nuts 6 are provided at both ends.
It has a male screw 5 that engages with the ferrule 1 and a sleeve hole 4 that aligns the ferrule 1. Further, as shown in FIG. 5, two rows of slits 11 are axially inserted at both ends and sandwiched between the slits 11. And a slope 15 is provided in the vicinity of the fitting end of the coupling nut 6.

In the above construction, the ferrule 1 is inserted into the adapter 3 from both ends, and the coupling nut 6 is inserted.
Although the optical fiber 2 is connected, the female screw 5 interferes with the inclined surface 15 when the coupling nut 6 is completely tightened, the segment 12 is pushed down, and the ferrule 1 is fixed in the sleeve hole 4 without any gap. As a result, the optical fibers 3 held by the ferrule 1 are aligned and connected and fixed with good reproducibility.

Embodiment 4 This embodiment will be described with reference to FIG. FIG. 6 is a partial cross-sectional view of the adapter 3, in which two rows of slits 11 penetrating the sleeve holes 4 are inserted in the axial direction, and the male screw 5 of the section 12 formed between the slits 11 is fitted. A hole is provided in the vicinity of the end of the joint, and a protrusion 13 made of resin capable of self-tapping is installed in this hole, and the sleeve hole 4 is circumferentially divided into three equal parts based on the above-mentioned segment 12. Each has a raised portion 16.

In the structure as described above, the ferrule 1 is inserted into the adapter 3 from both ends and the coupling nut 6 is tightened to connect the optical fiber 2 in the same manner as in FIG. 1, but when the coupling nut 6 is completely tightened, the protrusion 13 is formed. Is elastically deformed due to an incomplete screw, the segment 12 is pushed down, and the ferrule 1 comes into contact with the raised portion 16 and is fixed in a three-point supported state.
As a result, the optical fibers 3 held by the ferrule 1 are aligned and connected and fixed with good reproducibility.

Embodiment 5 Although the construction is similar to that of Embodiment 4, the shallow valley diameter 14 shown in FIG. 3 is provided as an alternative to the protrusion 13 of the adapter 3 shown in FIG. 6, and further shown in FIG. 6 similarly to Embodiment 4. The raised portion 16 is provided and the adapter is formed by resin integral molding.

As in FIG. 1, the ferrule 1 is inserted into the adapter 3 from both ends and the coupling nut 6 is tightened to connect the optical fiber 2. However, when the coupling nut 6 is completely tightened, the shallow valley diameter 14 as shown in FIG. The section 12 interferes with each other, the segment 12 is pushed down, and the ferrule 1 is raised to the ridge 16.
It comes into contact with and is fixed in a three-point supported state.

Embodiment 6 This embodiment will be described with reference to FIG. FIG. 7 is a partial cross-sectional view of the adapter 3, in which two rows of slits 11 penetrating the sleeve hole 4 are axially inserted, and the male screw 5 of the section 12 formed between the slits 11 is fitted. A slope 15 is provided in the vicinity of the end of the joint, and the above-mentioned piece 1 is inserted in the sleeve hole 4.
The raised portions 16 are provided at positions that are divided into three substantially equal parts in the circumferential direction from the reference point 2.

In the above-mentioned structure, the ferrule 1 is inserted into the adapter 3 from both ends and the optical fiber 2 is connected by tightening the coupling nut 6 as in FIG. Female screw 5
Interfere with each other, the segment 12 is pushed down, and the ferrule 1 comes into contact with the raised portion 16 and is fixed in a three-point supported state.

Embodiment 7 This embodiment will be described with reference to FIG. FIG. 8 is a partial cross-sectional view of the adapter 3, in which two rows of slits 11 penetrating the sleeve hole 4 are inserted in the axial direction, and a segment 12 formed between the slits 11 is formed at a position of about 120 °. The adapter 3 has a structure in which two holes are provided in the vicinity of the fitting end portion of the male screw 5 of these pieces 12, and a projection 13 made of resin capable of self-tapping is embedded in the hole.

In the structure as described above, the ferrule 1 is inserted into the adapter 3 from both ends and the coupling nut 6 is tightened to connect the optical fiber 2 as in the case of FIG. 1, but when the coupling nut 6 is completely tightened, the protrusion 13 is formed. Is elastically deformed due to an incomplete screw, the segment 12 is pushed down, and the ferrule 1 comes into contact with the two segments 12 and is fixed in a three-point supporting state. As a result, the optical fibers 3 held by the ferrule 1 are aligned and connected and fixed with good reproducibility.

Embodiment 8 Although the construction is similar to that of Embodiment 7, a shallow valley diameter 14 shown in FIG. 3 is provided as an alternative to the protrusion 13 of the adapter 3 in FIG. 8 to form the adapter by resin integral molding.

As in FIG. 1, the ferrule 1 is inserted into the adapter 3 from both ends, the coupling nut 6 is tightened to connect the optical fiber 2, and when the coupling nut 6 is completely tightened, the shallow valley diameter 14 is applied as shown in FIG. The portions interfere with each other, the segment 12 is pushed down, and the ferrule 1 comes into contact with the two segments 12 and is fixed in a three-point supporting state. As a result, the optical fibers 3 held by the ferrule 1 are aligned and connected and fixed with good reproducibility.

Embodiment 9 This embodiment will be described with reference to FIG. FIG. 9 is a partial cross-sectional view of the adapter 3, in which two rows of slits 11 penetrating the sleeve hole 4 are inserted in the axial direction, and a segment 12 formed between the slits 11 is located at a position of about 120 °. The adapter 3 has a structure in which two slopes 15 are provided near the fitting end portion of the male screw 5 of these pieces 12.

In the structure as described above, the ferrule 1 is inserted into the adapter 3 from both ends and the coupling nut 6 is tightened to connect the optical fiber 2 as in the case of FIG. 1, but when the coupling nut 6 is completely tightened, the ferrule 1 is attached to the slope 15. Female screw 5
Interfere with each other and the segment 12 is pushed down, and the ferrule 1 is fixed in a three-point supporting state.

Embodiment 10 This embodiment will be described with reference to FIGS. FIG. 10 is a partial perspective view of the adapter 3, in which a key groove 17 penetrating the sleeve hole 4 is inserted in the axial direction, and further intersects with the key groove 17 in a direction orthogonal to the key groove 17 and has a smaller diameter than the root diameter of the male screw 5. Ring groove 18
Is provided. Further, as shown in FIG. 11, a tapered key 19 which fits into the key groove 17 is provided on the outer peripheral surface, and a projection 20 is provided on the inner peripheral surface facing the tapered key 19 and a notch 21 is formed on a part of the outer periphery. And a thin ring 22 that engages with the ring groove 18 is prepared.

In the structure as described above, the adapter 3 is provided with a thin ring 22 in the ring groove 18 and a taper key 19
The push-out ring groove 18 is preliminarily mounted so that the top of the is positioned on the back side. After that, as in Figure 1, ferrule 1
Is inserted into the adapter 3 from both ends, and the coupling nut 6 is tightened to connect the optical fiber 2. However, when the coupling nut 6 is completely tightened, the taper key 19 of the thin ring 22 interferes with the female screw 5 and the protrusion 20 is pushed down. The ferrule 1 is fixedly connected.

Embodiment 11 This embodiment will be described with reference to FIG. FIG. 12 is a partial sectional view for explaining the gist of the present invention.
The configuration is similar to the above, but the difference is that the raised portions 16 are provided in the sleeve hole 4 of the adapter 3 at positions substantially divided into three in the circumferential direction from the protrusion 20 as a base point.

Therefore, as shown in FIG. 1, the ferrule 1
Is inserted into the adapter 3 from both ends, and the coupling nut 6 is tightened to connect the optical fiber 2. However, when the coupling nut 6 is completely tightened, the taper key 19 of the thin ring 22 interferes with the female screw 5 and the protrusion 20 is pushed down. The ferrule 1 contacts the raised portion 16 and is fixed in a three-point supporting state.

Twelfth Embodiment This embodiment will be described with reference to FIG. FIG. 13 is a partial sectional view for explaining the gist of the present invention.
The configuration is similar to that of the thin-walled ring 2 except that the adapter 3 is provided with keyways 17 at two positions of approximately 120 °.
Also in No. 2, a taper key 19 and a protrusion 20 are provided in a portion facing the key groove 17.

Therefore, as shown in FIG.
Is inserted into the adapter 3 from both ends, and the coupling nut 6 is tightened to connect the optical fiber 2. However, when the coupling nut 6 is completely tightened, two taper keys 19 of the thin ring 22 interfere with the female screw 5 and the protrusion 20 Is pushed down and the ferrule 1 is fixed in a three-point supporting state.

[0033]

As described above, according to the present invention, as shown in the first to twelfth embodiments, the shape of each component may be simple in any case, and the ferrule may be formed on the inner wall surface of the sleeve hole of the adapter. Since it can be fixed without a gap, it is possible to suppress variations in signals generated when the optical fiber connector is attached and detached. This has the effect of improving the transmission efficiency of light energy when connecting each segment in the optical transmission circuit.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical fiber terminal for explaining a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a main part of FIG. 1 of the present invention.

FIG. 3 is a partial cross-sectional view of main parts for explaining a second embodiment of the present invention.

FIG. 4 is a sectional view of an optical fiber terminal for explaining a third embodiment of the present invention.

5 is a perspective view illustrating a part of the main part of FIG. 4 of the present invention. FIG.

FIG. 6 is a cross-sectional view of main parts for explaining a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view of main parts for explaining a sixth embodiment of the present invention.

FIG. 8 is a cross-sectional view of main parts for explaining a seventh embodiment of the present invention.

FIG. 9 is a sectional view of a main part for explaining a ninth embodiment of the present invention.

FIG. 10 is a partial perspective view of the main parts for explaining the tenth embodiment of the present invention.

FIG. 11 is a perspective view of main parts for explaining the tenth embodiment of the present invention.

FIG. 12 is a cross-sectional view of main parts for explaining an eleventh embodiment of the present invention.

FIG. 13 is a sectional view of a main part for explaining an twelfth embodiment of the present invention.

FIG. 14 is a sectional view of an optical fiber terminal for explaining a conventional example.

FIG. 15 is a sectional view of an optical fiber terminal for explaining another conventional example.

[Explanation of symbols]

 1 Ferrule 2 Optical Fiber 3 Adapter 4 Sleeve Hole 6 Coupling Nut 12 Section 13 Projection 14 Shallow Valley Diameter 15 Slope 16 Protrusion 17 Key Groove 18 Ring Groove 19 Taper Key 20 Projection

Claims (8)

[Claims] 1. An optical fiber terminal of a screw fastening type in which a ferrule is fitted in a sleeve hole provided in an adapter, and is connected and fixed by a coupling nut, wherein an outer peripheral portion of a male screw engaged with the coupling nut of the adapter is provided. Two rows of slits that penetrate to the sleeve hole are inserted in the axial direction, a hole is provided near the coupling nut mating end of the male screw of the section formed between these slits, and self-tapping is possible in this hole A method for connecting and fixing an optical fiber terminal, characterized in that a protrusion made of a different resin is installed, and a coupling nut is fastened to push down the protrusion to fix the ferrule in the sleeve hole. 2. A screw fastening type optical fiber terminal in which a ferrule is fitted in a sleeve hole provided in an adapter and connected and fixed by a coupling nut, wherein the adapter is integrally molded of resin and engages with the coupling nut. Two rows of slits penetrating to the sleeve hole are axially inserted in the outer circumference of the male screw, and the valley diameter is provided near the coupling nut fitting end of the male screw of the section formed between the slits. Connection of an optical fiber terminal characterized in that a threaded portion having a shallower diameter or a larger thread diameter is provided, and the ferrule is fixed in the sleeve hole by pushing down the threaded portion of the above section by fastening the coupling nut. Fixing method. 3. An optical fiber terminal of a screw fastening type in which a ferrule is fitted in a sleeve hole provided in an adapter, and is connected and fixed by a coupling nut, wherein a male screw outer peripheral portion engaging with the coupling nut of the adapter is provided. Two rows of slits penetrating to the sleeve hole are inserted in the axial direction, and the section formed between these slits is provided with a wedge-shaped inclined surface that interferes with the female screw near the coupling nut fitting end, A method for connecting and fixing an optical fiber terminal, characterized in that a ferrule is fixed in a sleeve hole by pushing down the above-mentioned section by fastening a coupling nut. 4. A sleeve hole is provided with ridges at respective positions which are divided into three substantially in the circumferential direction from the base point of the section, and a coupling nut is fastened to the ridge section of the sleeve hole and the section at three points. The method for connecting and fixing an optical fiber terminal according to claim 1, 2 or 3, wherein the ferrule is fixed. 5. The outer peripheral portion of the male screw engaging with the coupling nut is provided with two rows of slits penetrating up to the sleeve hole in two axial positions at positions of about 120 ° in the circumferential direction. The method of connecting and fixing an optical fiber terminal according to claim 1, claim 2 or claim 3. 6. An optical fiber terminal of a screw fastening type in which a ferrule is fitted in a sleeve hole provided in an adapter, and is connected and fixed by a coupling nut, wherein an outer peripheral portion of a male screw engaging with the coupling nut of the adapter is provided. A key groove that penetrates to the sleeve hole is provided, and a ring groove with a diameter smaller than the root diameter of the coupling nut fitting screw is formed by intersecting the groove in the direction orthogonal to the groove. A tapered ring is provided to prepare a thin ring that engages the ring groove with a protrusion on the inner peripheral surface facing the tapered key, and the thin ring is placed so that the top of the tapered key is located on the back side. It is installed in the ring groove of the connector and the coupling nut is tightened to push down the taper key to fix the ferrule in the sleeve hole. A method for fixing and fixing optical fiber terminals. 7. An optical fiber terminal of a screw fastening type in which a ferrule is fitted in a sleeve hole provided in an adapter and connected and fixed by a coupling nut, wherein an outer peripheral portion of a male screw engaged with the coupling nut of the adapter is provided. A key groove that penetrates to the sleeve hole is provided, and further, a ring groove that intersects in the direction orthogonal to this groove and has a diameter smaller than the root diameter of the coupling nut fitting screw is provided. Protrusions are provided at positions roughly divided into three equal parts in the direction, and then a taper key that fits into the key groove is provided on a part of the outer circumference and a protrusion is attached to the inner peripheral surface facing the taper key. Prepare a thin-walled ring that engages with the above-mentioned ring groove, attach this thin-walled ring to the ring groove of the adapter so that the top of the taper key is located on the back side, and tighten the coupling nut. Thus, the taper key is pushed down to fix the ferrule in the sleeve hole at the three points of the protrusion and the protrusion of the sleeve hole. 8. An optical fiber terminal of a screw fastening type in which a ferrule is fitted in a sleeve hole provided in an adapter and connected and fixed by a coupling nut, wherein an outer peripheral portion of a male screw engaged with the coupling nut of the adapter is provided. Insert a key groove that penetrates to the sleeve hole in the axial direction at two locations at a position of about 120 ° in the circumferential direction, and further intersect the direction orthogonal to this groove to make a ring groove with a diameter smaller than the root diameter of the coupling nut fitting screw. Next, two taper keys that fit into the key groove are provided on a part of the outer circumference, and a thin ring that engages with the ring groove with a protrusion is provided on the inner peripheral surface facing the taper key. , This thin ring is installed in the ring groove of the adapter so that the top of the taper key is located on the back side, and the coupling nut is tightened to push down the taper key and press the three Connecting and fixing method of an optical fiber terminal being characterized in that so as to secure the ferrule into the hole.