JPH06100689B2 - Optical fiber end coating removal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a) Field of Industrial Application The present invention relates to an apparatus for removing a coating of an end portion of an optical fiber by a predetermined length as a pre-process for fusion splicing between the end portions of the optical fiber.

b) Conventional technology The conventional means for removing the coating on the end of an optical fiber is almost the same as the one used for peeling an electric wire, for example, 0.3m in diameter at the tip of pliers.
It is done with a nipper with a hole in the mth position, a stripper with a hole at the tip of scissors, or nose pliers, etc.If only the outer coating is hooked and pulled out of those holes, the coated part will peel off and the central cladding Is exposed.

However, the above work alone cannot completely remove the resin, and the resin for the coating often remains. Therefore, a soft cloth, for example, a felt impregnated with alcohol, or a so-called silicotte, a cotton used by women for makeup at the time of impregnating acetone, etc.
The clad was sandwiched between them and the force was applied in the longitudinal direction to wipe it off.

c) Problems to be Solved by the Invention Needless to say, a high-strength tensile force is applied to an optical fiber cable during use, and even a fusion spliced portion is required to have strength enough to withstand the applied tensile force. .

By the way, the tensile breaking strength of the optical fiber main body excluding the splicing part was recorded as the maximum value of 7.1 kg, the minimum value of 6.38 kg, and the average value of 6.75 kg as a result of the test.

On the other hand, the tensile rupture strength of the optical fiber including the connection part peeled by the above-mentioned known method is about 1/10 of the above value, that is, the maximum value is 0.88 kg, the minimum value is 0.53 kg, and the average value is 0.71 kg. However, it was confirmed that the connection part was very weak against breakage.

Such a tensile strength reduction phenomenon is a physical treatment applied when the coating is peeled off, that is, of course, a pulling process with a nipper or a stripper, and even a friction finish with a felt or a silicot, the surface of the clad has abrasive particles. As a result of the experiment, it was confirmed that the frictional forces act to cause fine scratches (microcracks) and fractures occur at the scratched portions.

Despite such defects, due to the excellent use of optical fibers as communication lines, it is finally in practical use, and it is urgently necessary to make sure the high-strength connection between the end portions of the optical fibers. The place of connection work is forced to be performed not only in a production factory where the work environment is maintained but also in a very limited and narrow field. In other words, the inside and outside of a house, the inside and outside of a manhole, or, in the case of a submarine optical fiber cable, on a laying ship, requires no time and effort, and requires no special skill. I want to connect the end of the optical fiber strongly.
Therefore, as a pre-process of the connecting work, it is desired to enable a work of uniformly and highly efficiently peeling off the jacket of the end portion of the optical fiber. We would like to create a rational and simple coating removal device that can complete the work.

An object of the present invention is, as a pretreatment step of connecting work between optical fiber end portions, a resin tank for forming an optical fiber jacket is worked by a chemical treatment, not by a physical force, so that a work of a normal width is performed. The object is to provide a compact and high-performance device that can be removed quickly, surely, and easily, not only in a space but also in a very limited and narrow space. The object is to provide a device that accurately determines the replacement time of the processing liquid due to the small amount of the liquid, avoids quality deterioration and significant interruption of work, and makes it possible to continue high-quality work. .

d) Means for solving the problem Since microcracks, which cause breakage, are scratched by applying a physical force to the clad of the optical fiber, the adverse effect of the microcracks is re-examined and the optical crack is generated by a chemical treatment. The resin layer forming the fiber jacket is removed.

That is, the present invention, a melting tank containing a liquid that melts the resin layer forming the jacket of the optical fiber, and a cleaning tank containing a cleaning liquid are equidistant from the center of rotation of the horizontally rotatable table, While arranging a plurality of each at equal intervals, a chuck that can move up and down is provided and the end of the optical fiber is hung and fixed on the chuck downward. Then, it is to obtain an apparatus for temporally controlling the vertical movement of the chuck and the horizontal movement of the table so that the chuck is lowered on a plurality of cleaning tanks.

Alternatively, the present invention is, in addition to the above configuration, additionally provided with a means for vibrating the liquid in the tank.

e) Action First, the end of the optical fiber is fixed downward to the chuck at the elevated position.

Next, the table is rotated so that the melting tank is located immediately below the chak.

When the chuck is lowered and stopped at the lowered position, the end portion of the optical fiber is dipped into the melting tank to a predetermined depth, and the solution in the tank melts the resin tank of the jacket.

The chuck is raised when the set time for completion of melting is reached.

After the chuck has been lifted, the table is rotated to position the cleaning tank directly below the chuck. When the chuck is lowered again and stopped at the lowered position, the end of the optical fiber is dipped in the washing tank to a predetermined depth and washed.

The chuck is raised when the set time for completion of cleaning is reached.

Finally, the optical fiber end is removed from the chuck.

When the liquid in the bath is vibrated when the end of the optical fiber is dipped, the end of the optical fiber is vibrated in the liquid, so that the melting of the jacket and the cleaning after melting can be achieved quickly. It

Further, according to the present invention, in addition to the above basic operation, a plurality of melting tanks and cleaning tanks are arranged at positions equidistant and equally spaced from the center of rotation of the table. With the intermittent rotation, the order of immersion of the optical fiber end into each tank is determined, and the pollution degree due to the melting of the tank liquid is naturally the highest in the first tank liquid. The lowest of the final bath liquids. Therefore, for example, if the removal and cleaning of the jacket at the end of the optical fiber are few from the beginning of the work, the cleaning liquid in the final cleaning tank, such as acetone, will not be contaminated and it will remain clean. However, when the work progresses and the number reaches 10 to 10 or more, acetone in the final cleaning tank is also polluted. Therefore, by observing the degree of contamination of acetone in the final washing tank, and when the degree of contamination reaches a certain level, the treatment liquids in all the tanks including the melting tank and the washing tank are replaced with new ones all at once. And if you try to regenerate,
It is possible to carry out the jacket removal work continuously at all times.

f) Example First, as shown in FIG. 4 and FIG.
Consists of a glass layer consisting of a central core 1a and a clad 1b that wraps the outside thereof, an ultraviolet curable or thermosetting urethane or silicone resin 1c that wraps the outside, and nylon 1d that further wraps the outside. The outer cover formed by the resin layer and to be removed according to the present invention is the resin layer 1c, 1d (dotted line in FIG. 4) within a predetermined length from the end face 1e of the optical fiber, for example, within 5 mm. After being peeled off, the clad 1b made of a glass layer was exposed, and the surface of the clad 1b was finely scratched by the conventional method, leading to breakage. In the present invention, the resin layers 1c and 1d (see FIG.
By chemical treatment of the broken line), peeling is performed without making any fine scratches.

1 to 3, each end of the pair of optical fibers 1 and 1 is suspended and fixed downward by a chuck 2. The holder 3 for supporting the chuck 2 has a female screw hole at its base end, and a male screw rod 4 is screwed into the hole, and the upper and lower ends of the male screw rod are rotatably supported by brackets 5 and 6, respectively. Each bracket is fixed so as to project forward from the frame 7. A bevel gear 8 is provided on the upper end of the male screw rod 4, and the gear is a reversible motor 9
Engages with the bevel gear 10 provided on the output shaft of. On the other hand, the limit switches 11 and
12 is provided, and the contacts 3 and 14 are attached to the holder 3 corresponding thereto.

Therefore, when the holder 3 moves down to the lower limit, the contact 24 operates the limit switch 12 to stop the driving of the reversible motor 9. After the lapse of a set time by a timer (not shown), the motor 9 is driven in the reverse direction, the holder 3 starts to move upward, and the contact 13 operates the limit switch 11 at the upper limit thereof, and the drive of the motor 9 is stopped. , Wait for next command input.

It is more efficient to provide a plurality of chucks 2 for grasping the optical fiber, for example, four to six chucks.

Next, the circular table 15 has its rotary shaft 16 rotatably supported by a pair of horizontal frames 17 and 18, and the rotary shaft 16 is further provided with a Geneva driven gear 19 having six grooves.

On the other hand, a counter shaft 20 is also rotatably attached to the pair of horizontal frames 17 and 18, and a Geneva driving gear 21 is provided on the shaft, and the Geneva driven gear 19 is provided.
Engage with.

A bevel gear 22 is provided at the lower end of the counter shaft 20,
The gear engages with a bevel gear 24 provided on the output shaft of the motor 23.

Therefore, the output of the motor 23 is transmitted to the Geneva driving gear 21 on the counter shaft 20 via the bevel gears 24 and 22, and the Geneva driven gear 19 driven by the Geneva driven gear 19 is 1/6 rotation, that is, 60.
Intermittent rotation is performed by intermittently performing angular displacement of °, and intermittent rotation feed is provided to the rotary shaft 16 and the table 15 which are integral with the rotary rotation 16 and the table 15.

25, 25a, 25b ... are the outer circumference of the lower surface of the table 15 and are spaced by 60 ° 6
On the other hand, the micro switch 26 is provided on the horizontal frame 17 and the contactor
The switch 26 is operated by 25, 25a, 25b ..., and the drive of the motor 23 is stopped each time the switch is operated.
The driving of the motor 23, which has been stopped, is restarted after the elapse of a time set by a timer (not shown).

Now, the recesses (see FIG. 2) for placing the tanks are provided at six positions at equal intervals along the circumference equidistant from the center of rotation on the circular table 15.

In order to chemically remove the resin layers 1c and 1d which are the jackets of the optical fiber 1, first, the resin layers are melted by immersing them in a bath of concentrated sulfuric acid, and then they are immersed in a bath of acetone. Therefore, it is necessary to thoroughly wash off the concentrated sulfuric acid that has adhered and the molten resin tank, and in the illustrated embodiment, three melting tanks and three cleaning tanks are provided, as described in detail below. .

There are two types of tanks to be installed, the first of which is a melting tank 27, 27a, 27b in which a liquid that dissolves the resin layers 1c and 1d forming the optical fiber jacket, for example, concentrated sulfuric acid, is put, and the second is cleaning. Cleaning tank 28, 28a, 28b containing a liquid, for example, acetone
These tanks are small bottles that are easy to carry, in which the solution is put in advance and set in the dent each time to be used.

In order to promote the reaction in the melting tanks 27, 27a, 27b, it is better to raise the liquid temperature to 60 ° C to 120 ° C. Therefore, oil tanks 29, 29a, 29b are provided outside the tanks, respectively, and immersed therein, and further, heaters 30, 30a, 30b and a temperature sensor (not shown) are respectively inserted in the oil tanks. , Keep the temperature of oil in the tank at a predetermined level at all times.

The cleaning tanks 28, 28a, 28b are used at room temperature.

In order to perform melting and washing quickly, a vibration generator (not shown) is provided at the bottom of each tank to give vibration to each liquid in the tank.

The following is an example of the time required for the end of the optical fiber to be dipped in each tank.

Therefore, the drive of the two motors 9 and 23 is controlled based on the setting of such time.

When the acetone contamination level of the final cleaning tank 28b reaches a certain level, the processing solutions in all six tanks are replaced with new ones and the operation is continued.

In FIG. 2, 31 is an operation panel, 32 is a manual button, 33
Is an automatic button, 34 is a power on / off switch, 35 is a start button, 36 is an emergency stop button, 37 is an emergency rise command button,
38 is an emergency lowering command button, 39 is a manual button for moving each tank to the operating position, 40 is an operation switch for controlling the ascending / descending of the optical fiber, and 41 is a table forward / reverse rotation operation switch.

g) Effects As described in detail above, the present invention can be applied not only to the work in the factory where the environment is maintained but also to the work in the site where the space is remarkably limited, and the treatment liquid which can be carried to the site. Considering measures that assume an absolute shortage,
In order to solve the above two problems, firstly, the number of processing tanks is not limited to one or the minimum number, and a small-sized multiple arrangement method, which is contrary to downsizing, is adopted. Therefore, it is possible to restrict the expansion of the pollution level of the processing liquid in a stepwise manner, so that the consumption of the processing tank can be suppressed to a small amount, while all the processing tanks can be treated based on the pollution degree of the processing tank in the final immersion order. Since it is possible to timely determine the simultaneous replacement and regeneration of the treatment liquid of the above, it is possible to continue the efficient work without significantly interrupting the outer skin removing work of the optical fiber end and without degrading the quality. became.

Further, according to the present invention, in order to solve the above two points, the small number of small-sized processing tanks are arranged in a circle on a table without simply arranging them, and the table can be rotated. Further, since the rotation operation of the table and the vertical movement of the optical fiber end fixing chuck can be temporally operated according to a certain dipping order, the whole device can be compact and compact. It is possible to respond to use in a limited work space reliably, easily and quickly.

[Brief description of drawings]

The drawings illustrate one specific embodiment of the inventive device. FIG. 1 is a right side view in vertical section along line 1-1 of FIGS. 2 and 3, FIG. 2 is a plan view, FIG. 3 is a front view, and FIG. FIG. 5 is a side view of the end portion of the fiber, and FIG. 5 is an enlarged view of the end surface of the optical fiber seen from the right side in FIG. 1 ... Optical fiber, 1a ... Core, 1b ... Clad, 1c ... Urethane-based or silicone-based resin, 1d ... Nylon, 1e ... Optical fiber end, 1e ... Chuck, 3 ... Holder, 4 …… Male screw rod, 5 and 6 …… Bracket, 7 …… Frame, 8 …… Bevel gear, 9 …… Variable motor, 10 …… Bevel gear, 11 and 12 …… Limit switch, 13 and 14 …… Contact, 15 …… Table, 16 …… Rotary shafts, 17 and 18 …… A pair of horizontal frames, 19 …… Geneva driven gear, 20 …… Counter shaft, 21 …… Geneva drive gear, 22 …… Bevel gear, 23 …… Motor , 24 …… Bevel gear, 25,25a, 25b …… Contact, 26 …… Micro switch, 27,27a, 27b …… Melting tank, 28,28a, 28b …… Cleaning tank, 29,29a, 29b …… Oil Tank, 30, 30a, 30b ... Heater (with temperature sensor).

Claims (5)

[Claims] 1. A vertically movable chuck capable of suspending and fixing an end portion of an optical fiber downward, a melting tank containing a liquid that melts a resin layer forming a jacket of the optical fiber, and a cleaning liquid. And a horizontally rotatable table in which a plurality of cleaning tanks are placed at equidistant and equidistant positions from the center of rotation, and the chuck in the ascending position is first moved to the plurality of chucks according to a certain dipping order. The vertical movement of the chuck and the horizontal movement of the table are temporally related to each other so as to be lowered on each of the melting tanks and then on the plurality of cleaning tanks. A device for removing coating from the end of an optical fiber. 2. A vertically movable chuck capable of suspending and fixing an end of an optical fiber downward, a melting tank containing a liquid that melts a resin layer forming an outer cover of the optical fiber, and a cleaning liquid. And a cleaning tank, each of which is horizontally rotatable at a position equidistant from the center of rotation, and which is capable of vibrating the liquid in the tank. , According to a certain dipping order, first, on the plurality of melting tanks, and then on the plurality of cleaning tanks, the chuck is moved up and down and the table is moved horizontally. An apparatus for removing coating at the end of an optical fiber, characterized by performing temporally related control. 3. The apparatus according to claim 1 or 2, wherein the liquid contained in the melting tank is concentrated sulfuric acid. 4. The apparatus according to claim 1 or 2, wherein the liquid contained in the cleaning tank is acetone. 5. In order to keep the liquid in the melting tank at a temperature of 60 ° C. to 120 ° C., the tank is immersed in an oil tank of a heater overheat type. The apparatus according to item 3.