JP2005015278A - Method and apparatus for manufacturing optical fiber and extractor used for the manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a method and an apparatus for manufacturing an optical fiber wherein productivity can be improved by increasing rate of operation of drawing equipment. <P>SOLUTION: The optical fiber manufacturing apparatus 1 has the drawing equipment 7 which performs heating drawing of a large-diameter preform 3, an extractor 9 which extracts the drawn preform 5 through a drawing passage and a cutter 11 which cuts the extracted preform 5 into a prescribed length. The processes in different equipment are performed in parallel at different treatment positions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber manufacturing method and manufacturing apparatus, and a take-out apparatus used in the manufacturing apparatus, and in particular, it is not necessary to pause the stretching process even during the cutting process, and by parallel processing of the stretching process and the cutting process, The present invention relates to an improvement for enabling efficient production of an optical fiber preform.
[0002]
[Prior art]
As a method of manufacturing an optical fiber, (1) a first step of obtaining a starting core rod by connecting a seed rod or a dummy rod made of quartz by heating and melting at both ends of a glass rod having a core and a part of a cladding; 2) Second step of depositing the generated glass fine particles on the outer periphery of the starting core rod to form a porous glass body to obtain a composite base material. (3) Heating the composite base material into a transparent glass A third step of obtaining a thick preform, (4) a fourth step of drawing the thick preform to a predetermined diameter for drawing, and (5) a preform extended to a predetermined length in the fourth step. 5th step of obtaining a cut stretched base material, (6) a 6th step of machining the end of the stretched base material into a spindle shape, and (7) a dummy rod at one or both ends of the stretched base material after the 6th step. Optical fiber mother for drawing and welding And (8) the eighth step of drawing the optical fiber preform for drawing to the optical fiber in order is proposed, and the fourth and fifth steps are continued. Therefore, a manufacturing apparatus has been proposed in which a cutting machine that cuts a stretched preform into a predetermined length is disposed immediately below a stretching apparatus that performs the fourth step (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-81535
[Problems to be solved by the invention]
However, the preform stretched to a predetermined diameter in the fourth step is quite hot immediately after the stretching treatment and cannot be cut until it is cooled to a certain temperature. Therefore, in the case of the conventional manufacturing method and apparatus in which the cutting process is performed directly under the stretching apparatus, during the cooling of the stretched preform and the cutting process, it is necessary to stop the operation of the stretching apparatus. There has been a problem that productivity is poor due to a reduction in the operating rate of the apparatus.
[0005]
The present invention has been made in view of the above-mentioned problems, and its purpose is to stretch a large-diameter preform to a predetermined diameter for drawing, to cool the stretched preform and to cut it thereafter. There is no need to stop the operation for the process, and the optical fiber manufacturing method and manufacturing apparatus and the manufacturing apparatus can be operated almost continuously and the operating rate of the stretching apparatus can be increased to improve the productivity. It is in providing the taking-out apparatus used for.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an optical fiber manufacturing method according to the present invention includes a stretching step of heating and stretching a large-diameter preform and a stretched high-temperature preform as described in claim 1. It has a taking-out process taken out from an apparatus, and a cutting process which cuts the taken-out preform, and the extending process and the cutting process are carried out at different processing positions.
[0007]
In order to achieve the above object, an optical fiber manufacturing apparatus according to the present invention includes, as described in claim 2, a stretching apparatus for heating and stretching a large-diameter preform, and a stretched high-temperature preform. It is characterized by having a take-out device for taking out and moving the material from the stretching device, and a cutting device for cutting the moved preform.
[0008]
In the optical fiber manufacturing method and manufacturing apparatus configured as described above, the preform stretched to a predetermined diameter in the stretching process performed by the stretching device is, for example, taken out by the take-out device when reaching a certain length. According to the process, it is taken out from the stretching passage directly below the stretching device, transferred to a cutting device at an appropriate position deviated from directly below the stretching device, and cut into a predetermined length.
Therefore, for example, the cutting device is disposed at an appropriate position away from directly below the stretching device, and the transfer of the take-out device is performed so that the cooling time of the stretched preform is the time during the transfer process from the stretching device to the cutting device. If the loading operation is set, as described above, the stretching process and the cutting process can be performed in parallel at different processing positions.
[0009]
In addition, it is preferable that the take-out device has a plurality of chucks for gripping the preform at a plurality of locations in the longitudinal direction.
In this case, for example, a part of a plurality of chucks that are spaced apart in the axial direction of the preform is equipped so as to be movable in the axial direction of the preform, and the preform taken out from the stretching device. Is a cutting device that feeds the preform removed from the stretching device in the axial direction for a predetermined length by combining on / off of the gripping operation by the chuck equipped with the fixed and on / off of the movement operation of the chuck equipped to be movable The amount of feed can be adjusted.
[0010]
Further, as described in claim 4, it is preferable that the preform contact portion of the chuck is formed of a heat resistant material.
In this way, when the high-temperature preform immediately after being stretched by the stretching apparatus is gripped, the preform contact portion is not damaged by heat.
Also, if the preform contact portion is equipped so as to be replaceable, only the preform contact portion can be replaced when it is damaged by long-term use.
[0011]
According to a fifth aspect of the present invention, the chuck may be configured to be swingable with respect to the central axis of the preform.
In this way, even if the preform stretched by the stretching device is bent, the chuck can swing according to the bend, thereby preventing the contact area of the chuck with respect to the preform from fluctuating. .
[0012]
According to a sixth aspect of the present invention, the take-out device may be provided with a sensor for preventing interference with the optical fiber holding chuck in the drawing device.
The position of the chuck for holding the optical fiber in the stretching apparatus moves downward as the stretching process proceeds, and the position fluctuates.If the sensor is equipped as described above, the position of the chuck on the take-out apparatus side is changed. By adjusting the movement, interference between both chucks can be prevented.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical fiber manufacturing method and manufacturing apparatus according to a preferred embodiment of the present invention and a take-out apparatus used in the manufacturing apparatus will be described below in detail with reference to the accompanying drawings.
First, after describing an embodiment of an optical fiber manufacturing apparatus according to the present invention and a take-out apparatus used in the apparatus, the optical fiber manufacturing of the present invention is carried out by the manufacturing apparatus according to the embodiment. A method will be described.
[0014]
As shown in FIG. 1, an optical fiber manufacturing apparatus 1 according to an embodiment of the present invention is a preform 3 having a predetermined diameter suitable for processing with a wire drawing machine. 5, a drawing device 9 for heating and drawing, a take-out device 9 for taking out the drawn high-temperature preform 5 from a drawing passage extending vertically directly under the drawing device 7, and cutting for cutting the taken-out preform 5 into a predetermined length The apparatus 11 is comprised.
[0015]
The stretching device 7 has a fitting portion 21 a that supports the upper end of the preform 3 at the lower end, a support rod 21 that can be lifted and lowered by the upper end being gripped by the chuck 19, and a plug suspended on the lower end of the support rod 21. The heater 23 that heats the outer periphery of the reform 3, the furnace body 25 that covers the periphery of the heater 23 and the preform 3, and the preform 5 that is stretched and fed out below the furnace body 25 are separated at two positions in the axial direction. It has a pair of chucks 27 and 28 to support. The pair of chucks 27 and 28 are provided so as to be individually movable up and down.
[0016]
The large-diameter preform 3 attached to the stretching device 7 is connected to, for example, (1) both ends of a glass rod having a core and a part of a clad by heating and melting a quartz seed rod or a dummy rod. A first step of obtaining a starting core rod, (2) a second step of forming a porous glass body by depositing the generated glass fine particles on the outer periphery of the starting core rod, and (3) The composite base material is formed into a predetermined large diameter by performing a third step or the like to obtain a large diameter preform by heating and converting to a transparent glass.
[0017]
As shown in FIGS. 1 and 2, the take-out device 9 includes a pair of chucks 31 and 32 (FIG. 2 omits the chuck 32) for gripping the preform 5 at two positions spaced apart in the longitudinal direction. ), A chuck position adjusting mechanism 34 that supports the pair of chucks 31 and 32 so as to be movable along the axial direction of the preform 5, an opening / closing operation (on / off operation) of the pair of chucks 31 and 32, and a chuck A main body 36 incorporating a control mechanism for controlling the amount of movement of the pair of chucks 31, 32 by the position adjusting mechanism 34, and an unillustrated take-out movement that enables the main body 36 to move within a horizontal plane perpendicular to the axis of the preform 5. Mechanism.
[0018]
As shown in FIG. 2, the pair of chucks 31 and 32 in the take-out device 9 and the chucks 27 and 28 of the stretching device 7 come into contact with the outer peripheral surface of the preform 5 from one side of the preform 5. The cross section includes a first arm 43 having a preform contact portion 41 and a second arm 47 having a preform contact portion 45 at a position facing the preform contact portion 41.
[0019]
In the pair of chucks 27, 28, 31, and 32, at least one of the first arm 43 and the second arm 47 is equipped to be movable in the horizontal direction, and the preform contact portion 41 and the preform that face each other. The preform 5 is gripped by sandwiching the preform 5 with the contact portion 45.
[0020]
In the present embodiment, the chuck position adjusting mechanism 34 provided in the take-out device 9 rotationally drives a feed screw 34a screwed to a chuck body 49 that supports the first arm 43 and the second arm 47 by a motor 34b. Then, as shown by an arrow (A) in FIG.
In the present embodiment, although not shown, the chuck 32 is also provided with a similar chuck position adjustment mechanism, and the chucks 31 and 32 are individually movable up and down.
[0021]
In the case of this embodiment, the preform contact portions 41 and 45 of the pair of chucks 27 and 28 provided in the stretching device 7 and the pair of chucks 31 and 32 provided in the take-out device 9 are made of polyimide or the like. It is formed of a non-metallic heat-resistant material and is attached to the first arm 43 and the second arm 47 that support them in a replaceable manner.
[0022]
More specifically, the preform contact portion 41 having a substantially V-shaped cross section has a pair of heat-resistant pieces 42 attached to each of the V-shaped surfaces, as shown in FIGS. As shown in FIGS. 2 and 3B, a single heat-resistant piece 46 is attached to the tip of the preform contact portion 45 facing the V-shaped surface.
The heat-resistant piece 42 has a flat plate shape in which the upper and lower edge portions 42a are slightly bent in the same direction and formed in a U-shaped cross section, and the upper and lower edge portions 42a are respectively engaged with the upper and lower surfaces of the preform contact portion 41. Screw 53 is fixed.
The heat-resistant piece 46 is fixed to the tip of the preform contact portion 45 with a screw 55. A countersunk screw is used as the screw 55, and the screw top portion 55 a is configured to slightly sink from the surface of the heat-resistant piece 46 and to be out of contact with the preform 5.
[0023]
In the case of this embodiment, as shown by arrows (A) and (B) in FIGS. 1 (a) and 4 (a) and 4 (b), the chucks 31 and 32 provided in the take-out device 9 are With respect to the central axis of the preform 5, the preform 5 is swingable at a predetermined angle α in the horizontal direction and a predetermined angle β in the vertical direction. The swing structure will be described later.
[0024]
Further, in the case of the present embodiment, as shown in FIG. 2, the take-out device 9 is equipped with a sensor 51 for preventing interference with the optical fiber holding chucks 27 and 28 in the stretching device 7.
In the sensor 51 shown here, the detection piece 51a fixedly provided around the chucks 27 and 28 on the stretching device 7 side and the detection piece 51b provided on the chucks 31 and 32 on the take-out device 9 side have a predetermined amount or more. If the close distance is approached, the chucks may interfere with each other, and the positions of the chucks 31 and 32 on the take-out device 9 side are corrected. The detection pieces 51a and 51b can be composed of light receiving and emitting elements.
[0025]
As shown in FIGS. 4 (a) and 4 (b), the preform contact portions 41, 45 are arranged on the outer surface of the chuck body 49 of the stretching device 7 and the take-out device 9 as shown in FIGS. In this configuration, the first arm 43 and the second arm 47 provided so as to be movable in a horizontal direction on the installed guide rail 56 are swingably attached. 4A is a plan view in which a part of the pair of chucks 27, 28, 31, 32 is omitted, and FIG. 4B is a side view of the main part of the pair of chucks 27, 28, 31, 32. .
[0026]
As shown in FIG. 4A, the preform contact portion 41 is fixed to the tip of a shaft 58 that passes through a yoke 43 a formed on the first arm 43 via a bearing 70. A compression spring 72 is wound around the shaft 58, and the compression spring 72 swings the preform contact portion 41 perpendicularly to the center axis of the preform 5 at a predetermined angle β (left and right swinging). ) To return. 4A is a plan view seen from the line P-P in FIG. 4B.
Further, as shown in FIG. 4B, the preform contact portion 41 has two pairs of compression springs 74 and 75 interposed between the upper and lower end portions of the yoke 43 a, and these compression springs 74 and 75. Is a return action when the preform contact portion 41 swings at a predetermined angle α in the horizontal direction with respect to the central axis of the preform 5 (vertical swing).
[0027]
The preform contact portion 45 is provided such that a shaft 77 fixed to the second arm 47 is inserted and can be swung up and down via a bearing 79 interposed between the preform 77 and the shaft 77.
[0028]
As shown in FIG. 1 (c), the cutting device 11 is equipped to be horizontally movable at a position away from the stretching passage directly below the stretching device 7.
The cutting device 11 includes a preform positioning cylinder 61 and a positioning chuck 63 into which the preform 5 is inserted, and a cutting rotation for cutting the preform 5 fixed by the preform positioning cylinder 61 and the chuck 63 at a fixed position. When the preform 5 is fed into the preform positioning cylinder 61 from the take-out device 9, the preform 5 that has been fed is cut into a predetermined length.
The preform cut to a predetermined length is sent to the next step by a conveying means (not shown) to be shaped as an optical fiber preform for drawing.
[0029]
Next, the manufacturing method of the optical fiber implemented by the manufacturing apparatus 1 demonstrated above is demonstrated.
First, as illustrated in FIG. 1A, the stretching device 7 performs a stretching process in which the large-diameter preform 3 is heated and stretched to the preform 5 having a predetermined diameter. When the manufactured preform 5 reaches a predetermined length, the take-out device 9 evacuated to the side of the stretching passage directly below the stretching device 7 advances to the stretching passage and stretches the high-temperature preform 5. The extraction process to take out from the passage is performed. Only during this take-out operation, the stretching process by the stretching device 7 is suspended.
[0030]
As shown in FIG. 1B, the take-out device 9 holds the preform 5 with a pair of chucks 31 and 32, and moves in the horizontal direction or the vertical direction with respect to the drawing path directly below the drawing device 7. Then, as shown in FIG. 1 (c), the preform 5 having a predetermined length is taken out from the stretching passage and sent to the cutting device 11. As soon as the preform 5 is removed from the stretching passage by the movement of the take-out device 9, the stretching device 7 starts the next stretching step.
As shown in FIG. 1C, the cutting device 11 that has received the preform 5 from the take-out device 9 cuts the preform 5 supported by the preform positioning cylinder 61 and the chuck 63 into a predetermined length by the cutting rotary blade 65. A cutting step is performed.
[0031]
The above-described stretching process, taking-out process, and cutting process can be performed in parallel by setting the processing position shifted for each process.
[0032]
In the manufacturing method performed by the optical fiber manufacturing apparatus 1 configured as described above, the preform 5 stretched to a predetermined diameter in the stretching process performed by the stretching apparatus 7 is, for example, taken out when reaching a certain length. By the take-out process carried out by the device 9, it is taken out from the drawing passage directly under the drawing device 7, transferred to the cutting device 11 at an appropriate position deviated from directly under the drawing device 7, and cut into a predetermined length.
Accordingly, as shown in the drawing, the cutting device 11 is disposed at an appropriate position away from directly below the stretching device 7, and the cooling process time of the preform 5 stretched during the transfer process from the stretching device 7 to the cutting device 11 is as follows. As described above, if the transfer operation of the take-out device 9 is set, the stretching step, the take-out step, and the cutting step can be performed in parallel as described above.
Therefore, the stretching apparatus 7 that stretches the large-diameter preform 3 to a predetermined diameter for drawing does not need to be stopped for cooling the stretched preform 5 or for a subsequent cutting step, and is almost continuously performed. The operation rate of the stretching device 7 can be increased, and the productivity can be improved.
[0033]
The take-out device 9 shown in the present embodiment includes a pair of chucks 31 and 32 that are spaced apart from each other in order to grip the preform 5, and the pair of chucks 31 and 32 are arranged on the shaft of the preform 5. Since it is equipped so as to be movable in the direction, the preform 5 removed from the stretching device 7 can be axially combined by appropriately combining on / off of the gripping operation by the chucks 31 and 32 and on / off of the moving operation. The feeding amount to the cutting device 11 can be adjusted by feeding out a predetermined length, and the cutting length in the cutting device 11 can be arbitrarily adjusted.
[0034]
Further, in the take-out device 9 shown in the present embodiment, since the preform contact portions 41 and 45 are formed of a heat-resistant material, even if the high-temperature preform 5 immediately after being stretched by the stretching device 7 is gripped, the preform is in contact. The reform contact portions 41 and 45 are less likely to be damaged by heat and can be safely taken out.
Moreover, since the heat-resistant material used for the preform contact portions 41 and 45 is a non-metallic material such as polyimide, the contamination of the molten metal material mixed as an impurity as compared with the case where it is formed of a metal material such as stainless steel. Occurrence can be prevented.
Furthermore, since the preform contact portions 41 and 45 are exchangeably equipped, if the use is damaged by long-term use, only the preform contact portions 41 and 45 can be replaced, and the initial gripping can be performed at low cost. Performance and heat resistance can be restored.
[0035]
Further, in the take-out device 9 shown in the present embodiment, the pair of chucks 31 and 32 equipped for gripping the preform 5 can swing at a predetermined angle with respect to the preform 5. Even if the preform 5 is bent, the chuck swings according to the bend, so that the contact area of the chuck with respect to the preform 5 can be prevented from changing, and the preform 5 can be bent. An acceptable and stable grip can be maintained.
[0036]
In addition, the position of the lower chuck 28 for holding the optical fiber in the stretching device 7 moves downward as the stretching process proceeds and the position fluctuates. Since the sensor 51 for preventing the interference with the fiber holding chuck 28 is provided, the position of the chuck 32 on the take-out device 9 side is moved and adjusted in accordance with the output of the sensor 51, whereby both chucks are adjusted. Can be prevented, and the stretched preform 5 can be taken out smoothly and safely.
[0037]
In the present invention, the number of the chucks for gripping the preform provided in the take-out device 9 for taking out the preform 5 drawn by the drawing device 7 is not limited to the above embodiment. In order to stably hold the preform 5 and send the preform 5 to the cutting device 11, if necessary, the number of chucks can be increased to an arbitrary number.
[0038]
Further, in the above embodiment, the pair of chucks 31 and 32 provided in the take-out device 9 are movable along the axial direction of the preform 5, but at least one chuck moves in the axial direction of the preform 5. If equipped, it is possible to realize the feeding of the cutting device 11, and it is not always necessary to make all the chucks equipped in the take-out device 9 movable along the axial direction of the preform 5.
[0039]
【The invention's effect】
According to the optical fiber manufacturing method and manufacturing apparatus of the present invention, since the preform stretched by the stretching device can be quickly moved from directly under the stretching device by the take-out device, for example, the cutting device is moved away from just below the stretching device. If the transfer operation of the take-out device is set so as to be the cooling processing time of the preform that has been placed in an appropriate position and during the transfer process from the stretching device to the cutting device, as described above, the stretching step The extraction step and the cutting step can be performed in parallel.
Therefore, the stretching device that stretches the large-diameter preform to a predetermined diameter for drawing does not need to be stopped for cooling the stretched preform and the subsequent cutting process, and should be operated almost continuously. The productivity can be increased by improving the operating rate of the stretching apparatus.
[0040]
The take-out device used in the optical fiber manufacturing method and manufacturing apparatus according to the present invention can be removed from the stretching device by equipping a part of the plurality of chucks equipped so as to be movable in the axial direction of the preform. The preform can be fed out in the axial direction for a predetermined length to adjust the feed amount to the cutting device, and the cutting length in the cutting device can be arbitrarily adjusted.
[0041]
Further, the take-out device used in the optical fiber manufacturing method and manufacturing apparatus of the present invention is such that the preform contact portion is not damaged by heat when the high-temperature preform immediately after being stretched by the stretching device is gripped. Can be safely removed and operated. Furthermore, when the preform contact portion hurts due to long-term use, only the preform contact portion can be replaced, and the original gripping performance and heat resistance performance can be restored at low cost.
[0042]
In addition, the take-out device used in the optical fiber manufacturing method and manufacturing apparatus of the present invention allows the chuck to swing according to the bending even if the preform stretched by the stretching device is bent. It is possible to prevent the contact area of the chuck from fluctuating with respect to the reform, and to allow the preform to bend and maintain a stable grip.
[0043]
Further, the take-out device used in the optical fiber manufacturing method and manufacturing apparatus of the present invention prevents both chucks from interfering with each other regardless of the position of the chuck on the stretching device side that has moved down as the stretching process proceeds. The stretched preform can be taken out smoothly and safely.
[Brief description of the drawings]
1A and 1B are explanatory diagrams of an operation procedure of an embodiment of an optical fiber manufacturing apparatus according to the present invention, in which FIG. 1A is an explanatory diagram of a state in which a preform is stretched, and FIG. FIG. 5C is an explanatory diagram of a state where the reformer has been taken out, and FIG. 5C is an explanatory diagram of a state where the preform that has been taken out is delivered to the cutting device.
FIG. 2 is an enlarged perspective view of the take-out device shown in FIG.
FIGS. 3A and 3B are views of a preform contact portion for explaining a state of attaching a heat-resistant piece, in which FIG. 3A is an exploded perspective view of a preform contact portion having a substantially V-shaped cross section, and FIG. It is a disassembled perspective view of a reform contact part.
4A and 4B are diagrams for explaining a swinging structure of the chuck, in which FIG. 4A is a plan view of the chuck with a part omitted, and FIG. 4B is a side view of the main part of the chuck.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical fiber manufacturing apparatus 3 Thick diameter preform 5 Preform 7 Stretching apparatus 9 Extraction apparatus 11 Cutting apparatus 21 Support rod 23 Heater heater 25 Furnace bodies 27 and 28 Chuck 31 and 32 Chuck 34 Chuck position adjustment mechanism 34a Feed screw 36 Main body 41 Preform contact portion 42, 46 Heat-resistant piece 43 First arm 45 Preform contact portion 47 Second arm 51 Sensor 61 Preform positioning cylinder 63 Chuck 65 Cutting rotary blade 70 Bearing 72, 74, 75 Compression spring 79 Bearing

Claims (6)

A stretching step for heating and stretching a large-diameter preform; a taking-out step for taking out the stretched high-temperature preform from a stretching device; and a cutting step for cutting the taken-out preform. The stretching step and the cutting step Is a method of manufacturing an optical fiber, which is performed at different processing positions. A stretching device for heating and stretching a large-diameter preform, a take-out device for taking out and moving the stretched high-temperature preform from the stretching device, and a cutting device for cutting the moved preform. An optical fiber manufacturing apparatus. The take-out device, wherein the take-out device has a plurality of chucks for gripping the preform at a plurality of locations in the longitudinal direction. The take-out apparatus according to claim 3, wherein the preform contact portion of the chuck is formed of a heat-resistant material. The take-out device according to claim 3 or 4, wherein the chuck is provided so as to be swingable with respect to a central axis of the preform. The take-out apparatus according to any one of claims 3 to 5, wherein the take-out apparatus is equipped with a sensor for preventing interference with an optical fiber holding chuck in the drawing apparatus. .

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