JP2620331B2 - Optical fiber clamp mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber clamp mechanism for clamping an optical fiber, and more particularly, to an optical fiber clamp mechanism used for fusion splicing optical fibers.

(Prior art)

Currently used optical fibers include a single-core type optical fiber core as shown in FIG. 2 (a), and FIG. 2 (b)
And a multi-core type optical fiber ribbon. When such optical fiber cores are connected to each other, a fusion splicing device that removes the coating of the optical fiber cores 2 and 20 so that the optical fibers 1 and 10 face each other, aligns their optical axes, and thermally fuses them is known. It is used. In order to connect single-core optical fibers as shown in FIG. 2 (a), a fusion splicer for connecting single-core optical fibers is used, and FIG. 2 (b) In order to connect multi-core optical fiber ribbons as shown in (1), a fusion splicing device for connecting multi-core optical fibers is used. These fusion splicers are provided with a clamp mechanism for clamping the optical fiber, and the clamp mechanism slidably holds the optical fiber as shown in FIG. 3 (a). First, an optical fiber core 2a, a fusion splicer for connecting a single optical fiber core,
In the case of fusion-splicing 2b, the coatings of the tips of the optical fibers 2a and 2b to be connected to each other are peeled off, the tips are trimmed, and they are opposed to each other at a distance of about 1 to 2 to 3 mm. It is sandwiched between clampers 3a and 3b, which are mechanisms, and their optical axes are aligned. Next, with the relative positions of the clampers 3a and 3b fixed, the optical fibers 2a and 2b are
In the direction, the ends 2c and 2d of the optical fiber are brought closer to each other, and the distance between them is set to about 1 to 10 to 20 μm. When approaching, the optical fibers 1a and 1b slide in the clampers 3a and 3b. An example of the structure of the clampers 3a and 3b is shown in FIG.
Shown in The clamper structure shown in FIG. 5A includes a lower block 40 for holding an optical fiber and an upper block 41 for pressing the optical fiber 1a into the V-groove of the lower block 40. The optical fiber 1a is urged downward by a spring 43 or the like to hold and fix the optical fiber 1a in a V groove in the lower block 40.

On the other hand, in the multi-core batch fusion splicer for multi-core optical fiber,
As in the case of a single-core optical fiber, the coatings at the tips of the optical fibers 20a and 20b are peeled off as shown in FIG.
The plurality of optical fibers 10a and 10b are exposed, the tips are trimmed and sandwiched between the clampers 30a and 30b, the tips are opposed to each other, and the optical axes are aligned. Next, as shown in FIG. 4 (b), while the optical fibers 10a, 10b were slid within the clampers 30a, 30b, the tips of the optical fibers 10a, 10b were brought close to each other, and heat fusion was performed by electric discharge. Here, as shown in FIG. 5 (b), the structure of the clampers 30a, 30b is to align and hold the plurality of optical fibers 10a or 10b in the tape-shaped multi-core optical fibers 20a, 20b. The lower block 50 is provided with a plurality of V grooves. Then, the plurality of optical fibers 10a
Or, to hold 10b slidably,
Is pressed against the side surface of the V-groove with a predetermined pressing force.

In recent years, it has become necessary to connect multi-core and single-core composite cables or divide multi-core optical fiber ribbons into single-core optical fiber cores, and distribute and connect multi-core optical fiber cores to single-core optical fiber cores. Is emerging. Then, the single-core optical fiber core is connected by such a fusion splicer for connecting a multi-core optical fiber core. When connecting a single-core optical fiber (hereinafter, referred to as a single-core connection), the single-core optical fiber is clamped at the center of the V-groove array as shown in FIG. The fusion splicing was performed by the method. When connecting single-core optical fibers using the multi-core optical fiber fusion splicer as described above, it is necessary to consider that the optimal heat fusion temperature differs depending on the number of optical fibers to be thermally fused. It has also been considered to control the power supply voltage for discharging.

[Problems to be solved by the invention]

However, in the conventional fusion splicer for multi-core optical fiber,
The force Fkg for pressing the optical fiber against the V-groove of the lower block was always constant. Therefore, when a plurality of optical fibers, for example, n optical fibers are clamped, the pressing force applied to each one of the optical fibers is Fkg / n.
As shown in the figure, in the case of one cable, it becomes Fkg.
Therefore, when such a fusion splicer for multi-core optical fibers is used in a single-core optical fiber connection, when the optical fibers to be connected are clamped with a clamper and approached to the heat fusion position, the clamping force of the clamper is reduced. The optical fiber is too large and does not slide in the clamper. For this reason, if the force for moving the optical fiber is large, the optical fiber is buckled, and the single-core optical fiber cannot be connected. Also, if the pressing force Fkg is reduced to a value suitable for connecting single-core optical fibers, the force pressing the optical fibers to the V-grooves becomes too small when multiple cores are connected collectively. As a result, the optical fibers could not be sufficiently fixed in the V-grooves, and the optical axes of the opposing optical fibers to be connected were shifted from each other.

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

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical fiber clamping mechanism capable of achieving the above object and clamping an optical fiber with an optimum force regardless of the number of optical fibers to be clamped.

[Means for solving the problem]

In the optical fiber clamp mechanism of the present invention, a fiber holding member having a plurality of V grooves for aligning and holding an optical fiber, and an optical fiber disposed on the V groove side of the fiber holding member and housed in the V groove, A fiber pressing member for pressing against the groove and supporting the fiber pressing member at the tip,
A supporting arm for moving the fiber pressing member in a pressing direction and a pressing releasing direction to the V-groove, first and second springs for urging the tip of the supporting arm in the pressing direction, and urging forces of the second spring. An invalidating lever for reducing the force applied to the fiber holding member, and operating the urging force reducing lever to enable or disable the urging force of the second spring, thereby providing the fiber holding member with It is characterized in that the applied force is switched in two stages.

[Action]

Since the optical fiber clamp mechanism of the present invention is configured as described above, the urging force reducing lever is operated to
The force for pressing the optical fiber against the V-groove can be switched between two stages by making the biasing force of the spring effective or invalid. That is, when the number of optical fibers accommodated in each V-groove of the fiber holding member is large, the urging force of the second spring is made effective to increase the force applied to the fiber holding member, and to increase the force of the fiber holding member. When the number of optical fibers accommodated in each V-groove is small, the urging force of the second spring is invalidated, and the force applied to the fiber pressing member can be reduced. As described above, by switching the force applied to the fiber pressing member in two stages,
The pressing force applied to each optical fiber can be adjusted to an appropriate value.
For this reason, the pressing force applied to each optical fiber is not too weak to cause axial misalignment, and the pressing force applied to each optical fiber is not so strong that the optical fibers are distorted.

〔Example〕

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

Elements denoted by the same reference numerals have the same functions, and duplicate descriptions will be omitted.

FIG. 1 shows the configuration of an optical fiber clamp mechanism according to the present invention. FIG. 1 (a) shows a clamp operation state at the time of multi-core batch fusion splicing, and FIG. 1 (b) shows a clamp at the time of single fiber splicing. Indicates the operating state. As shown in the figure, the optical fiber clamping mechanism comprises a lower block 61 which is a fiber holding member having a plurality of V-grooves for aligning and holding the optical fiber 60 whose optical fiber core is stripped, The optical fiber 60 has an upper block 62 which is a fiber pressing member for pressing the optical fiber 60 against the side surface of the V-groove to clamp it. This lower block 61
The V-grooves formed therein are formed parallel to one another and hold the optical fibers aligned therein. This V
The groove is formed so that the upper portion of the optical fiber projects slightly from the upper surface of the lower block 61 when the optical fiber 60 is inserted. The lower surface 62a of the upper block 62 is formed flat so that a uniform pressing force can be applied to each of the plurality of optical fibers 60 held in the V-grooves in the lower block 61. The upper block 62 is supported at the tip of a support arm 63 via a rotation shaft 63a. The support arm 63 has an inverted U-shape as shown in the figure, and a flange 63b is provided at a base end thereof. When the support arm 63 moves up and down, the upper block 62 can be moved in the direction of the lower block 61 (the pressing direction) and in the direction opposite to this direction (the pressing release direction).

A tension spring 64, which is a first spring for urging the lower surface 62a 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 a base 65
It is connected to the. Further, pressing means is in contact with the upper surface of the flange portion 63b. The pressing means includes a first sleeve 66, a second sleeve 67, and a second sleeve 67, as shown in FIG.
And a compression spring 68. The first sleeve 66 is a cylindrical member through which the support arm 63 penetrates.
a is provided. The first sleeve 66 is fixed to the base 65. The second sleeve 67 is a cylindrical member through which a part of the first sleeve 66 and the support arm 63 penetrate.
Is provided. The compression spring 68 is the first sleeve 66
Between the lower surface 66b of the flange portion 66a of the second sleeve 67 and the upper surface 67b of the flange portion 67a of the second sleeve 67.
67 is pushed down. Further, the pressing force of the compression spring 68 is applied to the optical fiber clamp mechanism by the upper block.
A switching lever 69, which is a biasing force reducing lever that switches so as not to act on 62, is provided below the flange portion 67 a of the second sleeve 67. 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, so that the pressing force of the compression spring 68 is reduced by the support arm 63.
On the flange portion 63b.

Next, an operation state when a multi-core optical fiber is clamped will be described with reference to FIG.

As shown in FIG. 1A, when clamping a multi-core optical fiber, the switching lever 69 is moved downward,
The lower surface of the flange portion 67c of the second sleeve 67 is
Abuts on the upper surface 63c of the flange portion 63b.
In such a state, a compression spring 68 is attached to the support arm 63.
Spring force F1 acts downward, and the tension spring 64
Spring force F2 also acts downward. Therefore, the force of F1 + F2 acts on the upper block 62 downward, and presses the optical fiber against the V groove in the lower block 61. Therefore, the first
In the case of clamping a 5-fiber optical fiber as shown in FIG. 5 (a), each optical fiber is pressed against the V-groove with a force of (F1 + F2) / 5, ignoring the weight of each member. .

Next, an operation state when a single optical fiber is clamped will be described with reference to FIG.

As shown in FIG. 1 (b), when clamping a single-core optical fiber, the optical fiber 60 is inserted into a V-groove located substantially at the center of the V-groove row. Then, the switching lever 69 is moved upward to abut the lower surface of the flange portion 67a of the second sleeve 67, and further pushes the second sleeve 67 upward. By this pushing up, the lower surface 6 of the flange portion 67a of the second sleeve 67
7c is separated from the upper surface of the flange 63b of the support arm 63, so that the spring force F1 of the compression spring 68 does not act on the support arm 63. Therefore, only the spring force F2 of the tension spring 64 acts on the support arm 63, and pushes the upper block 62 downward. Therefore, if the own weight of each member is ignored, the pressing force acting on the single-core optical fiber 60 is F2.

In the description of the operating state, the case of the five-core optical fiber and the single-core optical fiber is described.
When four optical fibers are clamped, they may be clamped in an operation mode in which the pressing force acting on each optical fiber is close to the optimum value.

In the above embodiment, the spring force of the compression spring 68 is set to 40 gf, and the spring force of the tension spring 64 is set to 20 gf. In the state shown in FIG. And four-fiber and five-fiber optical fibers were heat-spliced in the state shown in FIG. 1 (a), and good connection was realized. Although it depends on the surface roughness of the inner surface of the V-groove and the optical fiber contact surface of the clamper and the friction coefficient of the material, in general, the pressing force on the optical fiber is 1 to 2 cores.
About 15 ~ 30g with optical fiber clamp of heart, 4 ~ 5
Good heat fusion splicing can be performed by setting the weight of the optical fiber of the core to about 30 to 60 g.

The present invention is not limited to the above embodiment, and various modifications can be considered.

Specifically, in the above embodiment, a description has been given of a mechanism for clamping an optical fiber having a maximum of five fibers. However, the number of optical fibers to be clamped is not limited to this, and may be any number.

Further, in the above embodiments and the like, an example in which the optical fiber clamp mechanism of the present invention is applied to a heat fusion splicing apparatus has been described. However, the present invention is not limited to this, and is applicable to an apparatus that needs to clamp various optical fibers. May be applied.

〔The invention's effect〕

As described above, the optical fiber clamp mechanism according to the present invention can hold an appropriate pressing force from a single core to a plurality of optical fibers, so that the pressing force applied to each optical fiber is too weak to cause axial misalignment, The pressing force applied to each optical fiber is not so strong that the optical fibers are not distorted. For this reason, proper alignment and fixing can be realized. In particular, when applied to a heat fusion device, it enables low fusion and good fusion splicing.

[Brief description of the drawings]

FIG. 1 is a view showing an optical fiber clamp mechanism and an operation state according to the present invention, FIG. 2 is a view showing a specific example of an optical fiber core, and FIG. 3 is a fusion of single optical fibers. FIG. 4 is a diagram for explaining a method for connecting the optical fibers, FIG. 4 is a diagram for explaining a method for fusion-splicing multi-core optical fibers, FIG. 5 is a diagram showing a conventional clamp structure, and FIG. It is a figure showing the state where a single core optical fiber was attached to a core optical fiber clamp structure. 60 ... optical fiber, 61 ... lower block, 62 ... upper block, 63 ... support arm, 64 ... tension spring, 65 ... base, 66 ... first sleeve, 67 ... second sleeve, 68 ... compression spring, 69 ... switching lever.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Noboru Kawasaki 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-59-72413 (JP, A) 64-55907 (JP, U)

Claims (1)

(57) [Claims] A fiber holding member having a plurality of V-grooves for aligning and holding an optical fiber; and an optical fiber disposed on the V-groove side of the fiber holding member and housed in the V-groove. A fiber pressing member for pressing against the groove, a support arm for supporting the fiber pressing member at the distal end, and moving the fiber pressing member in the pressing direction to the V-groove and the pressing release direction, and the distal end of the supporting arm First and second springs for urging the fiber in the pressing direction, and a urging force reducing lever for invalidating the urging force of the second spring and reducing the force applied to the fiber pressing member. By operating the urging force reducing lever to enable or disable the urging force of the second spring, the force applied to the fiber pressing member is cut in two stages. An optical fiber clamp mechanism characterized by replacement.