JPH0289009A - Optical fiber clamping mechanism - Google Patents

Abstract

PURPOSE:To clamp optical fibers with optimum force by constituting a pressing means for pressing the fibers to plural V-grooves in such a manner that the pressing force thereof can be varied. CONSTITUTION:A change lever 69 is moved downward to press the rear surface of a flange part 67c of a 2nd sleeve 67 to the front surface 63c of a flange part 63c of a supporting arm 63 in case of clamping the multiple optical fibers 60. The spring forces of a compression spring 68 and a tension spring 64 act downward on the supporting arm 63 at this time. An operator moves the change lever 69 upward to press the same to the rear surface of the flange part 67a of the 2nd sleeve 67 and further lifts the 2nd sleeve 67 upward in case of clamping the single optical fiber 67. Only the spring force of the tension spring 64 acts on the supporting arm 63 at this time and lifts an upper block 62 downward. Single to plural pieces of the optical fibers can be held by the adequate pressing force in this way and, therefore, the correct axis alignment and fixing are executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber clamp mechanism for clamping optical fibers, and more particularly to an optical fiber clamp mechanism used when fusion splicing optical fibers together.

[Prior art]

The fibers currently in use include single-core type optical fiber cores as shown in Figure 2(a), and multi-core type tape-shaped optical fiber cores as shown in Figure 2(b). There is. When connecting such optical fibers to each other, the coating of the optical fibers 2 and 20 is peeled off and the optical fibers 1 and 10
A fusion splicing device is used that places two pieces facing each other, aligns their optical axes, and heat-seals them. A fusion splicer for splicing single-core optical fibers is used to connect single-core type optical fibers as shown in FIG. 2(a), and as shown in FIG. 2(b). When connecting multi-core optical fiber tape-shaped core wires as shown in FIG. 1, a fusion splicing device for multi-core optical fiber core wire connection is used. These fusion splicing devices are provided with a clamp mechanism for clamping the optical fiber, and this clamp mechanism holds the optical fiber slidably, as shown in FIG. 3(a). First, the optical fiber core t1 is connected using a fusion splicer for splicing single-core optical fibers.
When fusion splicing 2a and 2b, the coating on the tips of the optical fibers 2a and 2b to be connected to each other is peeled off,
Trim the ends and place them facing each other with a distance of about N-2 to 3 mm, and then use the clamp mechanism (clamp <3a1).
3b and align their optical axes. Next, with the relative positions of the clampers 3a and 3b fixed, the optical fiber cores 2a and 2b are moved in the direction of arrow A to bring the tips of the optical fibers 2C% 2a closer to each other, and the distance between them is set to 11-10~ The thickness should be about 20 μm. When bringing these closer together, the optical fibers la and lb are connected to the clamper 3 a s3
Slide inside b. An example of the structure of this clamper 3as3b is shown in FIG. 5(a). The clamper structure shown in FIG. 5(a) is composed of a lower block 40 that holds an optical fiber and an upper block 41 that presses the optical fiber 1a into the V-groove of the lower block 40. The optical fiber 1a is held and fixed in the V-groove in the lower block 40 by being biased downward by a spring 43 or the like.

On the other hand, in the multi-fiber fusion splicing device for multi-core optical fibers, as in the case of single-core optical fibers, the coating at the tips of the optical fibers 20a and 120b is stripped off as shown in FIG. 4(a). , a plurality of optical fibers 10a, 10b are exposed, their tips are trimmed and inserted into clampers 30a, 30b, and the tips are made to face each other to align the optical axes. Next, the fourth
As shown in Figure (b), while sliding the optical fibers 10a and 10b within the clampers 30a and 30b,
The tips of a and 10b were brought close together and were thermally fused by electrical discharge. Here, the clamper 30a.

As shown in FIG. 5(b), the structure of 30b is such that the lower block 50 is designed to align and hold the plurality of optical fibers 10a or 10b in the tape-shaped multi-core optical fibers 20a, 20b. A plurality of V grooves are provided. In order to slidably hold the plurality of optical fibers 10a or 10b, the upper block 51 is pressed with a predetermined force to press the optical fibers in the V-groove against the side surfaces of the V-groove.

In recent years, there has been a need to connect multi-core and single-core composite cables, or to divide multi-core optical fiber ribbons into single-core optical fibers and distribute and connect multi-core optical fibers to single-core optical fibers. is occurring.

Single-core optical fibers have been spliced using such a fusion splicer for splicing multi-core optical fibers. Then, connect the single-core optical fiber (hereinafter referred to as single-core connection)
In this case, as shown in FIG. 6, a single-core optical fiber is clamped at the center of the groove array, and heat fusion splicing is performed as described above. When splicing single-core optical fibers using the multi-core optical fiber fusion splicer described above, it is important to take into account that the optimal thermal fusion temperature differs depending on the number of optical fibers to be thermally fused. However, it was also considered to control the power supply voltage for discharge.

[Problems to be solved by the invention]

However, in the conventional fusion splicing apparatus for multi-core optical fibers, the force F kg that presses the optical fiber against the V-groove of the lower block is always constant. Therefore, when clamping multiple optical fibers, for example n optical fibers, the pressing force applied to each optical fiber is F kg/n, but as shown in Figure 6, the force applied to each optical fiber is F kg/n. In the case of F kg
It becomes. Therefore, when using such a multi-core optical fiber fusion splicer to connect single optical fibers, when the clamper clamps the optical fibers to be spliced and brings them close to the thermal fusion position, the clamping force of the clamper is reduced. The optical fiber is too large and will not slide inside the clamper. Therefore,
If the force for moving the optical fibers is large, the optical fibers will buckle, making it impossible to connect single-core optical fibers. In addition, if the pressing force F kg is reduced to a value suitable for connecting satoshi optical fibers, multi-fiber
When making a bulk connection, the force pressing the optical fiber against the V-groove becomes too small.

As a result, the optical fibers could not be sufficiently fixed in the V-groove, resulting in misalignment of the optical axes of opposing optical fibers to be connected, making it impossible to thermally connect multiple optical fibers at once.

Therefore, there is a need for an optical fiber clamp mechanism that enables connection between various numbers of optical fibers using a multi-core optical fiber fusion splicer.

An object of the present invention is to achieve the above-mentioned problems and provide an optical fiber clamping mechanism that can clamp optical fibers with optimal force regardless of the number of optical fibers to be clamped.

[Means to solve the problem]

The optical fiber clamp mechanism of the present invention includes a holding member having a plurality of linear V grooves for aligning and holding optical fibers;
a holding member disposed on the V-groove side of the holding member for pressing the optical fiber housed in the V-groove against the V-groove; The present invention is characterized in that it includes a pressing means for pressing the holding member against the optical fiber holding member, and a means for making the pressing force of the pressing means variable.

[Effect]

Since the optical fiber clamping mechanism of the present invention is configured as described above, the force for pressing the optical fiber against V@ can be made variable, regardless of the number of optical fibers to be clamped.
Optimize your lamp.

〔Example〕

Embodiments according to the present invention will be described below with reference to the drawings.

Elements with the same reference numerals have the same functions, so duplicate explanations will be omitted.

FIG. 1 shows the configuration of an optical fiber clamping mechanism according to the present invention. FIG. 1(a) shows the clamping operation state during multi-fiber fusion splicing, and FIG. 1(b) shows the state of clamping during single-fiber splicing. Indicates clamp operation status. As shown in the figure, the optical fiber clamp mechanism includes a lower block 61 having a plurality of V grooves for aligning and holding optical fibers 60 from which VL fibers have been removed from the optical fiber cores;
(2) It has an upper block 62 that presses and clamps the optical fiber 60 held in the groove against the side surface of the V-groove.

The V-grooves formed in this lower block 61 are formed parallel to each other to align and hold the optical fibers therein. Furthermore, this groove is formed to a depth such that when the optical fiber 60 is inserted, the upper part of the optical fiber protrudes slightly from the upper surface of the lower block 61. The lower surface 62a of the upper block 62 is formed flat, and the lower surface 62a of the lower block 61
Uniform pressing can apply force to each of the plurality of optical fibers 60 held in the V-groove. This upper block 62 is connected to the support arm 6 via a rotating shaft 63a.
It is supported by 3. As shown in the figure, this support arm 63 has an inverted U-shape, and a flange portion 63b is provided at one end thereof.

A tension spring 64, which is a first pressing means for biasing the lower surface 62g of the upper block 62 toward the lower block 61, is connected to the lower end of the flange portion 63a. One end of this tension spring 64 is connected to a base 65. Furthermore, this flange portion 63
A second pressing means is in contact with the upper surface of b. This second
As shown in the figure, the pressing means includes a first sleeve 66;
It is composed of a second sleeve 67 and a compression spring 68. The first sleeve 66 is a cylindrical member through which the support arm 63 passes, and a flange portion 66a is provided at the upper portion of the first sleeve 66.

This first sleeve 66 is fixed to the base 65. Further, the second sleeve 67 is a cylindrical member through which a part of the first sleeve 66 and the support arm 63 pass, and a flange 67a is provided at the bottom thereof. The compression spring 68 is inserted between the lower surface 66b of the flange portion 66a of the first sleeve 66 and the upper surface 67b of the flange portion 67a of the second sleeve 67, and presses the second sleeve 67 downward. Furthermore, the optical fiber clamp mechanism is provided with a switching lever 69 below the flange portion 67g of the second sleeve 67 for switching the pressing force of the second pressing means so that no force is applied to the upper block 62. Then, by moving the switching lever 69 upward and bringing it into contact with the lower surface of the flange portion 67a of the second sleeve 67, and further pushing the second sleeve 67 upward, the second pressing is performed by the force supported by the means. It is possible to prevent it from acting on the flange portion 63b of the arm 63.

Next, the operating state when clamping a multi-core optical fiber will be explained using FIG. 1(a).

As shown in FIG. 1(a), when clamping a multi-core optical fiber, move the switching lever 69 downward,
The lower surface of the flange portion 67c of the second sleeve 67 is brought into contact with the upper surface 63c of the flange portion 63b of the support arm 63.

In this state, the spring force Fl of the compression spring 68 acts downwardly on the support arm 63, and the spring force F2 of the tension spring 64 also acts downwardly. Therefore, the force Fl+F2 acts downward on the upper block 62, pressing the optical fiber against the V-groove in the lower block 61. Therefore, when clamping five-core optical fibers as shown in Figure 1(a), each optical fiber is pressed against the V-groove with a force of (Fl + F2)15, if the weight of each member is ignored. It will be done.

Next, the operating state when clamping a single optical fiber will be explained using FIG. 1(b).

As shown in FIG. 1(b), when clamping a single-core optical fiber, the optical fiber 60 is inserted into F6 located approximately at the center of the V-groove array. Then, the switching lever 69 is moved upward to come into contact with the lower surface of the flange portion 67a of the second sleeve 67, and the second sleeve 67 is further pushed upward. Due to this pushing up, the lower surface 67c of the flange portion 67a of the second sleeve 67 is connected to the flange 63b of the support arm 63.
The spring force Fl of the compression spring 68 is kept away from the upper surface of the support arm 63 so that it does not act on the support arm 63.

Therefore, the tension spring 6 is attached to the support arm 63.
Only the spring force F2 of No. 4 acts to push the upper block 62 downward. Therefore, if we ignore the weight of each member,
The pressing force acting on the single-core optical fiber 60 is F2.

In addition, in the explanation of the operating state above, the case of a 5-core optical fiber and a single-core optical fiber is explained, but 2.3.4
When clamping the core optical fibers, it is sufficient to clamp them in an operating mode in which the force applied to each optical fiber is close to the optimum value.

In the above embodiment, the spring force of the compression spring 68 is 40 gf,
The spring force of the tension spring 64 was set to 20gf, and the single-core and double-core optical fibers were thermally spliced in the state shown in FIG. 1(b), and in the state shown in FIG. 1(a). 4
A good connection was achieved by thermal fusion splicing of core and five-core optical fibers. ■It varies depending on the surface roughness of the inner surface of the groove and the optical fiber contact surface of the clamper and the coefficient of friction of the material, but generally speaking, the force required to press against the optical fiber is smaller than the force required for clamping one to two optical fibers. 15-30g
For optical fibers with 4 to 5 cores, good thermal fusion splicing can be achieved by setting the weight to about 30 to 60 g.

The present invention is not limited to the above embodiments, and various modifications may be made.

Specifically, although the above embodiment describes a clamping mechanism for optical fibers with the largest helical core, the number of optical fibers to be clamped is not limited to this and may be any number.

In addition, in the above embodiment, an example in which the pressing force can be changed in two stages is explained, but by providing an additional sleeve on the outside of the first and second sleeves, the pressing force can be changed in two stages. It may be possible to change the .

Furthermore, in the above embodiment, force is generated when the optical fiber is pressed using a spring, but the invention is not limited to this; for example, the force is generated when the optical fiber is pressed using electromagnetic force or gravity. It may be made to occur.

Further, in the above embodiments, an example in which the optical fiber clamping mechanism of the present invention is applied to a thermal fusion splicing device has been described, but the present invention is not limited to this, and there is a need to clamp a certain number of optical fibers. It may also be applied to devices.

[Effects of the Invention] As explained above, the optical fiber clamping mechanism according to the present invention can properly press and hold multiple optical fibers from a single fiber with force, so that proper axis alignment and fixation can be achieved, and in particular, When applied to a heat fusion device, it enables good fusion splicing with low loss.

60... Optical fiber, 61... Lower block, 62
...Upper block, 63...Support arm, 64...
・Tension spring, 65...Base, 66...
1st sleeve, 67...2nd sleeve, 68...compression spring, 69...switching lever

[Brief explanation of drawings]

FIG. 1 is a diagram showing an optical fiber clamping mechanism according to the present invention and its operating state, FIG. 2 is a diagram showing a specific example of an optical fiber, and FIG. 3 is a diagram showing a concrete example of a coated optical fiber. FIG. FIG. 4 is a diagram explaining a method of fusion splicing multi-core optical fibers, FIG. 5 is a diagram showing a conventional clamp structure, and FIG. FIG. 3 is a diagram showing a state in which a Rishin optical fiber is attached to the Rishin optical fiber clamp structure.

Claims (1)

[Scope of Claims] 1. A holding member having a plurality of straight V-grooves for aligning and holding optical fibers, and a holding member disposed on the V-groove side of the holding member to hold the optical fibers accommodated in the V-grooves. a pressing member for pressing against the V-groove; pressing means connected to the pressing member for urging the pressing member and pressing the pressing member against the optical fiber holding member; and a pressing force of the pressing means. Optical fiber clamping mechanism equipped with a means to make the value variable. 2. The optical fiber clamp mechanism according to claim 1, wherein the plurality of V grooves are arranged in parallel at a predetermined pitch. 3. The pressing means is composed of a plurality of springs,
3. The optical fiber clamp mechanism according to claim 1, wherein the pressing force of the pressing means that acts on the holding member is made variable by selecting a compression spring that acts on the holding member.