JPH09127357A - Fusion splicing connection machine for optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision and reliability of a test of tensile strength which is conducted after the optical fiber is connected, i.e., screening. SOLUTION: After a clamp base 2 which holds the tip part of the optical fiber 1 is moved forward by a driving mechanism 20, the tips of optical fibers are connected by fusion splicing and then the clamp base is energized backward and the test of tensile strength is conducted. Then, the driving mechanism is equipped with a rod 12a, an elastic member 26 which energizes the clamp base backward about the rod, and a driving source such as a micrometer 12 for moving the rod forward and backward; when the fusion splicing is performed, the elastic material moves forward together with the rod and at the time of the screening, the elastic material deforms elastically to make its elastic restoring force operates on the clamp base as a screening force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber fusion splicer, and more particularly to a fusion splicer capable of accurately performing a tensile strength test, so-called screening, performed after splicing.

[0002]

2. Description of the Related Art A general structure of a conventional general fusion splicer will be described with reference to FIG. FIG. 4 shows a mechanism for clamping the optical fiber 1 to be connected and moving it in the axial direction, but since this has a bilateral symmetry across the center line CL, it is shown in FIG. Only half is shown.

In the figure, reference numeral 1 is an optical fiber to be connected, 1a.
Reference numeral 2 denotes a lead-out portion which is a bare fiber portion at the tip end thereof, 2 a clamp base for positioning and holding the optical fiber 1 at a predetermined position in the axial direction of the optical fiber, 3 a clamp lid, and 4 facing 1 A V-groove base for positioning and holding the lead-out portion 1a so that the axes of the pair of optical fibers are aligned with each other, 5 is a fiber clamp, and 6 is a clamp arm. Clamp base 2 above
Is supported by a bracket 7, which is a base, in a slidable state in the horizontal front-rear direction (left-right direction in FIG. 4) via a slide bearing 8, and is driven by a drive mechanism 9 to slide.

The drive mechanism 9 includes a motor 10 fixed to a bracket 7 and a motor gear 1 attached to its rotating shaft.
1, a micrometer 12 mounted on the wall portion 7a of the bracket 7, and a micrometer gear 13 mounted around the micrometer 12 and meshing with the motor gear 11. When the motor 10 is driven, the motor gear 11 , The micrometer 12 is actuated via the micrometer gear 13, and its operating rod 12a
Moves forward to press the front wall portion 2a of the clamp base 2 and slide the clamp base 2 forward (left in FIG. 4).

Further, between the lower portion of the front wall portion 2a of the clamp base 2 and the front wall portion 7b of the bracket 7, the clamp base 2 is biased rearward (to the right in FIG. 4) with respect to the bracket 7. A coil spring 14 as a pressing spring is interposed, and when the clamp base 2 is slid forward by the micrometer 12, the coil spring 14 is elastically compressed and when the pressing by the micrometer 12 is released. The elastic restoring force of the coil spring 14 retracts the clamp base 2 to return it to its original position.

In the conventional fusion splicer having the above structure,
The optical fiber 1 is held on the clamp base 2 and pressed by the clamp lid 3 to be positioned, the lead-out portion 1a is set on the V groove base 4 and is slidably pressed by the fiber clamp 5, and the micrometer 12 is driven by the drive mechanism 9. Although not shown, the optical fiber 1 is pushed forward by sliding the optical fiber 1 forward until the tip portions of the pair of optical fibers facing each other by operating the clamp base 2 reach a predetermined position optimum for fusion splicing. The tips of both optical fibers 1 to be connected are fusion-spliced by the electrodes. As a result, the clamp base slides forward by the stroke L1, and the coil spring 14 is elastically compressed as described above.

After connecting the optical fiber 1 as described above, the motor 10 is rotated in the reverse direction to retract the rod 12a of the micrometer 12 by a constant stroke L2 (L2 <L1). Then, the clamp base 2 by the micrometer 12
The pressing force to the front is released, and the clamp base 2 is urged by the elastic restoring force of the coil spring 14 so as to be pushed back. However, since the optical fiber 1 held by the clamp base 2 is already connected, the backward sliding of the clamp base 2 is restricted, and therefore the connected optical fiber 1 is pulled by the elastic restoring force of the coil spring 1. A stress is generated, and the tensile strength test of the connection portion, that is, screening is performed by using the tensile stress as a screening force.

[0008]

In the above case, the elastic restoring force T of the coil spring 14 which is the screening force is given by the equation T = K (L1-L2) where K is the elastic coefficient of the coil spring 14. Usually, the forward stroke L1 during fusion and the backward stroke L2 during screening
Is kept constant, the elastic restoring force T of the coil spring 14, which is a screening force, is also constant. Therefore, L1 and L2 are set to appropriate values so that the elastic restoring force T matches a predetermined tensile stress. Here, L1 is the initial position of the opposing clamp bases, the set position of the optical fiber, the length of the bare fiber portion, that is, the exit portion, the final position between the tip portions,
Etc.

However, in the above-mentioned conventional fusion splicer, there is a room such that the set position of the optical fiber with respect to the opposing clamp base is displaced forward and backward, and the length of the exit portion of the optical fiber tip is slightly changed. Therefore, the forward stroke L1 of the clamp base 2 is changed when the tip ends of the optical fibers are slid to reach a predetermined final position. Therefore, the forward stroke L1
When is changed, the value of the elastic restoring force T given to the optical fiber 1 as the screening force after fusion is changed as is apparent from the above equation. That is, when the optical fiber 1 is set to be displaced forward from the proper position, the forward stroke L1 of the clamp base 2 becomes smaller, and the elastic deformation amount of the coil spring 14 becomes smaller accordingly, so that the elastic restoring force thereof. T is also smaller than when it is appropriate. On the contrary, when the optical fiber 1 is set to be displaced rearward from the proper position, the clamp base 2
Coil spring 1 as much as the forward stroke L1 of
Therefore, the amount of elastic deformation of No. 4 increases, and therefore the elastic restoring force T thereof also increases. This means that even if the optical fiber 1 is set in the proper position,
Even when the lead-out length of the optical fiber 1 (the length of the lead-out portion 1a) has an error with respect to an appropriate value, the forward stroke L1 of the clamp base 2 at the time of fusing changes, and the same occurs.

If the screening force changes depending on the set position of the optical fiber 1 with respect to the clamp base 2 and the length of the lead-out as described above, the screening cannot always be performed under the same conditions. There has been a demand for effective improvement measures for further improving accuracy and reliability.

[0011]

In view of the above circumstances, the present invention has a pair of clamp bases arranged so as to face each other so as to approach and separate from each other, and holds the optical fibers to be connected to the clamp bases, respectively, and at least one of the clamp bases is held. An optical fiber fusion splicer having a structure in which a clamp base is moved forward by a drive mechanism so that the ends of the optical fibers are fusion-spliced together, wherein the drive mechanism is an axially forward / backward rod and the rod. An elastic member interposed between the tip of the clamp base and the clamp base to urge the clamp base in a direction of retracting the clamp base, and a drive source for moving the rod forward and backward, The drive source pushes the clamp base together with the elastic material to move the rod forward by advancing the rod, and the elastic material causes the drive source to retract the rod. Elastically deformed is characterized in that it is configured to provide a biasing force in a direction retracting the elastic restoring force to the clamp base when the. As the drive source, a micrometer or a structure in which the rod is moved back and forth by rotation of a cam is suitable.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. The fusion splicer of this embodiment is based on the conventional one shown in FIG. Therefore, the same components as those of the related art will be designated by the same reference numerals and detailed description thereof will be omitted.

First, a first embodiment will be described with reference to FIG. The fusion splicer of the first embodiment differs from the conventional fusion splicer in the structure of the drive mechanism for sliding the clamp base 2. That is, the conventional drive mechanism 9 has a structure in which the tip of the rod 12a of the micrometer 12 as a drive source is simply brought into contact with the clamp base 2 and pushed forward, whereas the drive mechanism in the present embodiment. A pressing member 21 is connected and fixed to the tip of the rod 12a of the micrometer 12 as a driving source, and the tip end of the pressing member 21 is connected to the clamp base 2 via a connecting mechanism 22. There is.

The connecting mechanism 22 fixes a cylindrical connecting body 23 on the rear surface side of the front wall portion 2a of the clamp base 2 so as to project rearward, and encloses the pressing body 21 therein. Further, the thrust bearing 24 and the spring receiver 25 are arranged on the rear surface side of the flange portion 21a provided at the tip of the pressing body 21, and the pressing spring is provided between the spring bearing 25 and the rear end portion of the connecting body 23. Coil spring (elastic material) 2
6 is interposed. Therefore, the connecting mechanism 22 is pressed by the biasing force of the coil spring 26.
Also, the rod 12a connected and fixed thereto is always biased forward (leftward in FIG. 1) with respect to the clamp base 2 via the spring bearing 25 and the thrust bearing 24.

In the drive mechanism 20 of the first embodiment in which the tip end portion of the pressing body 21 is connected to the clamp base 2 via the connecting mechanism 22 as described above, the clamp base 2 is used during fusion bonding.
When pushing the rod forward, the motor 10 is driven to actuate the micrometer 12 via the motor gear 11 and the micrometer gear 13 in the same manner as in the conventional case, whereby the rod 12a and the pressing body 21 move forward and press. The tip of the body 21 abuts on the front wall portion 2a of the clamp base 2, and the pressing body 21 directly presses the clamp base 2 to move it forward, so that the end portions of the optical fibers facing each other come to a predetermined final position. Move until At this time, the forward stroke L1 changes in accordance with the set position of the optical fiber 1 with respect to the clamp base 2 and the lead length, as in the conventional case. The rod 1
When the clamp base 2 is advanced by the pressing body 21 by advancing 2a, the connecting body 2 fixed to the clamp base 2
3 and thrust bearing 2 built into it
4, the spring receiver 25, and the coil spring 26 naturally advance integrally, and the coil spring 26 does not elastically deform at this point. In addition, the pressing body 2 is activated by the operation of the micrometer 12.
Although 1 rotates with the rod 12a, rotation of the pressing body 21 is allowed by the thrust bearing 24, and the coil spring 26 and the spring receiver 25 do not rotate.

Then, in the screening after the fusion splicing is completed, the motor 10 is reversed to rotate the rod 12
The a and the pressing body 21 are integrally retracted by a constant stroke L2. Then, although the clamp base 2 tries to retreat, the retreat of the clamp base 2 is restrained because the optical fiber 1 is already connected, and thus the coil spring 26 is elastically compressed and its elastic restoring force T is coupled. It acts on the clamp base 2 via the body 23, and therefore the elastic restoring force T of the coil spring 26 causes a tensile stress in the optical fiber 1, which serves as a screening force.

In this case, the elastic restoring force T of the coil spring 26
That is, the screening force applied to the optical fiber 1 has nothing to do with the forward stroke L1 at the time of fusion because the coil spring 26 simply advances and is not elastically deformed at the time of fusion, and the screening force does not affect the rod 12a at the time of screening. It will be determined only by the backward stroke L2. That is, in the first embodiment, the elastic restoring force T of the coil spring 26, which is the screening force, is T, where K is the elastic coefficient of the coil spring 26.
= KL2, and if the retreat stroke L2 is constant, the tensile stress T generated in the optical fiber 1, that is, the screening force is always constant.

Then, the backward stroke L of the rod 12a
Since 2 is determined by the operation amount of the micrometer 12, the operation amount of the micrometer 12 or the rotation amount of the motor 10 that operates the micrometer 12, and further, the operation time when the rotation speed is constant. It is possible to obtain a constant screening power only by always maintaining the constant value, and as a result, it is possible to improve the accuracy and reliability of the screening. It should be noted that, as described above, maintaining the operating amount of the micrometer 12, or the rotating amount and operating time of the motor 10 at a constant level can be easily performed by a manual operation. For example, as shown in FIG. When the operation amount of the micrometer 12 is detected by the encoder 31 via the gear 30 meshing with the gear 13, and the motor 10 is feedback-controlled by the control circuit 32 based on the detected value,
Control can be performed more easily and with high accuracy. Moreover, with such a configuration, if necessary, the operation amount of the micrometer 12 can be intentionally changed to make the screening force variable, or the rotation speed can be intentionally changed to adjust the screening time. It can be done easily.

In the first embodiment, the clamp base 2
12 as a driving source for moving the vehicle back and forth
However, as long as it is possible to move forward and backward by a predetermined stroke with high accuracy, it is of course possible to adopt a drive source of another type as well as the micrometer 12.
In the first embodiment, the pressing body 21 is connected and fixed to the tip of the rod 12a of the micrometer 12. However, it goes without saying that the form of the pressing body 21 can be appropriately changed. The tip portion 12a itself is pressed by the pressing body 21.
Of course, it may be formed in the form of. Further, the first
In the embodiment, the micrometer 12 is adopted as the driving source,
Therefore, since the rod 12a rotates when the micrometer 12 operates, the thrust bearing 24 is also used. However, the thrust bearing 24 may be omitted and a lubricant such as grease may be used. In the case where the rod 12a is simply moved forward and backward without rotating instead of using the micrometer 12, it is not necessary. Further, the forms of the connecting body 23 and the coil spring 26 constituting the connecting mechanism 22 are arbitrary as long as they have the functions as described above, and in particular, instead of the coil spring 26, a leaf spring, a disc spring, a torsion spring, a bellows, etc. It goes without saying that an elastic material of the form can be arbitrarily adopted.

Further, in the first embodiment, the micrometer can be manually driven. The retract stroke length in this case can be adjusted by reading the scale of the micrometer.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, the structure of the drive mechanism 39 for moving the clamp base 2 forward and backward is different from that of the first embodiment.
The drive mechanism 39 is configured to include a cam 40 as a drive source, a rod 41, and a coil spring (elastic material) 44. That is, in the second embodiment, the bracket 7
The rod 41 is attached to the wall portion 7a of the rod so that the rod 41 can move forward and backward, and the coil spring 42 as a push spring is interposed between the flange portion 41a formed at the base end portion of the rod 41 and the wall portion 7a of the bracket 7. The rod 41 is always biased rearward by the biasing force of the coil spring 42, and the base end thereof is pressed against the circumferential surface of the cam 40. The cam 40 has a spiral peripheral surface and is adapted to be rotated by the motor 10 via the motor gear 11 and the cam gear 43. By rotating the cam 40 clockwise from the state shown in FIG. 3, the circumferential surface of the cam 40 advances the rod 41 against the urging force of the coil spring 42, and a flange formed in the intermediate portion of the rod 41. The portion 41b is attached to the front wall portion 2 of the clamp base 2.
The clamp base 2 can be pushed out by being brought into contact with a and advanced. Further, a flange portion 41c is also formed on the tip end portion of the rod 41, and the flange portion 41c is formed.
A coil spring (elastic material) 44 as a push spring is also interposed between c and the front wall portion 2a of the clamp base 2. This coil spring 44 is for giving a screening force, and its elastic coefficient is set smaller than that of the coil spring 42. That is, this coil spring 44
Is a spring weaker than the coil spring 42 described above.
Instead of these coil springs 42 and 44, it is possible to employ an elastic material in the form of a leaf spring, a disc spring, a torsion spring, a bellows or the like.

In the second embodiment, upon fusion, the cam 40 is rotated to push the rod 41 forward as described above, whereby the flange portion 41b at the intermediate portion of the rod 41 is pushed.
Thus, the clamp base 2 is pushed forward and moved forward, and the tip ends of the optical fibers facing each other are moved forward until a predetermined final position is reached. The forward stroke L1 at this time changes in accordance with the set position of the optical fiber 1 and the lead-out length similarly to the conventional one and the first embodiment, and the cam 40 of the cam 40 corresponds to the forward stroke L1. The rotation angle changes. Further, although the coil spring 42 is elastically compressed as the rod 41 advances, the coil spring 44 does not
It simply moves forward with and does not elastically deform.

At the time of screening after fusion bonding, the cam 40 is rotated in the reverse direction by the motor 10. Then, the rod 41 pressed against the circumferential surface of the cam 40 is retracted by the urging force of the coil spring 42, and accordingly, the coil spring 44.
The clamp base 2 which is biased to the rear side by the rod 41 also tries to retract, but since the optical fiber 1 is already connected, the clamp base 2 is restrained from retracting, and the elasticity of the coil spring 44 of the clamp base 2 is restrained. Since the elastic restoring force of the coil spring 42 exceeds the restoring force, the coil spring 44
Is elastically compressed, and its elastic restoring force T acts on the clamp base 2 as a screening force. The screening force generated at this time is not related to the forward stroke L1 at the time of fusion, and is determined only by the backward stroke L2 of the rod 41 at the time of screening. Therefore, the backward stroke L2 is determined as in the case of the first embodiment. Only by keeping it constant, a constant screening ability can be obtained.

Here, the relationship between the backward stroke length and the rotation angle of the cam 40 is determined by the cam curve of the circumferential surface of the cam 40, and the backward stroke length can be controlled by the rotation amount of the motor 10. Therefore, as in the first embodiment, the screening ability can be controlled easily and with high accuracy.

The cam 40 can be manually driven in the second embodiment. In this case, the backward stroke length can be adjusted by providing the cam 40 with a dial having a scale or the like.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various design changes can be made. For example, the encoder 31 and the control circuit 32 exemplified in the first embodiment.
Also applies the cam curve to the control circuit 3 in the second embodiment.
It can be applied in the same manner by storing it in No. 2. Further, the configurations illustrated in the first and second embodiments may be appropriately combined, and for example, the cam 40 as in the second embodiment is used instead of the micrometer 12 as the drive source in the first embodiment. Or the rod 4 in the second embodiment
1, the rod 12a and the pressing body 2 as in the first embodiment.
1. Various configurations are conceivable, such as employing the connection mechanism 22.

Further, in the above embodiment, the present invention is applied to a fusion splicer in which a pair of clamp bases having a drive mechanism in the axial direction are installed symmetrically with respect to the center line CL. It was an example. In this case, the screening force urging means by the backward stroke of the present invention, that is, the coil spring 26 in the first embodiment and the coil spring 44 in the second embodiment may be attached to the drive mechanism of both clamp bases. It may be attached to the drive mechanism of one of the clamp bases.

Further, as in the case of a simple type fusion splicer,
When the driving mechanism is provided only on one of the clamp bases and the other clamp base is fixed, the screening biasing means by the backward stroke is attached to the drive mechanism of the one clamp base to implement the present invention. be able to.

Furthermore, the present invention can be applied to either a single-core fusion splicer or a multi-core fusion splicer.

[0030]

As described above, according to the present invention, the driving mechanism for moving the clamp base forward and backward is provided with the rod that can move forward and backward in the axial direction and the direction in which the clamp base moves backward with respect to the rod. It is composed of an elastic material that urges and a drive source for moving the rod forward and backward, and the drive source pushes the clamp base together with the elastic material through the rod to move forward,
At the time of screening, the elastic material is elastically deformed and its elastic restoring force is given as a biasing force in the direction of retracting with respect to the clamp base, so the retracting stroke of the rod of the drive source during screening is kept constant. By only maintaining it, the elastic restoring force of the elastic material can be kept constant and the screening force can always be kept constant.Therefore, regardless of the forward stroke of the clamp table during fusion bonding, screening is always performed under the same conditions. As a result, the accuracy of screening and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of an optical fiber fusion splicer according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a drive source control mechanism in the same connection machine.

FIG. 3 is a schematic configuration diagram of a main part of an optical fiber fusion splicer according to a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of essential parts showing an example of a conventional general optical fiber fusion splicer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 1a Output part 2 Clamp stand 10 Motor 12 Micrometer (driving source) 12a Rod 20 Driving mechanism 26 Coil spring (elastic material) 31 Encoder 32 Control circuit 39 Driving mechanism 40 Cam (driving source) 41 Rod 44 Coil spring (elasticity) Material)

Claims (3)

[Claims] 1. A pair of clamp bases are arranged to face each other so as to approach and separate from each other, hold optical fibers to be connected to the clamp bases respectively, and at least one of the clamp bases is moved forward by a drive mechanism to move the optical fibers. An optical fiber fusion splicer configured to splice the tips together, wherein the drive mechanism includes an axially forward / backward rod and an interposition between the tip of the rod and the clamp base. And a driving source for moving the rod forward and backward. The driving source advances the rod to move the rod forward and backward. The clamp base is pushed out together with the elastic material and moved forward, and the elastic material is elastically deformed when the drive source retracts the rod, so that the elastic restoring force is generated. Fusion splicer of the optical fiber, characterized in that it is configured to provide a biasing force in a direction to retreat the lamp base. 2. An optical fiber fusion splicer according to claim 1, wherein the drive source is a micrometer. 3. The optical fiber fusion splicer according to claim 1, wherein the drive source is configured to move the rod forward and backward by rotation of a cam. Connection machine.