JP5626091B2 - Optical fiber manufacturing method - Google Patents

Description

  The present invention relates to a method of manufacturing an optical fiber in which an optical fiber drawn in a drawing process is wound around a large bobbin, and is divided into small bobbins and wound.

  In the process of manufacturing an optical fiber, an ultraviolet curable resin is applied to a glass optical fiber obtained by drawing a glass base material, and is temporarily wound around a large bobbin. Then, it is colored as necessary, wound around a small bobbin with a predetermined length, and shipped as a product. However, it is necessary to remove optical fiber abnormal points (glass outer diameter abnormal part, bubble generating part, coating outer diameter abnormal part, bump generating part, etc.) generated in the drawing process so as not to be included in the product.

  As a technology to eliminate abnormal points, in-line inspection is performed from the beginning to the end of winding of the striate during winding of a large bobbin, and the inspection information corresponds to the length from the start to the end of winding of the striatum. It is known that the abnormal part is detected by taking the inspection information in the reverse direction from the end of winding to the beginning of winding and matching it with the position of the striatum when the striatum is cut into small bobbins. (For example, refer to Patent Document 1).

  In addition, a magnetic paint is applied in the vicinity of the abnormal point in the drawing process, and is cut and divided in the subsequent process (see, for example, Patent Document 2), the coating diameter of the abnormal part in the drawing process is changed, and in the subsequent process Techniques such as discarding (see, for example, Patent Document 3), storing the position of an abnormal part in the drawing process, and not coloring the abnormal part in the coloring process (for example, see Patent Document 4) are also known. .

JP-A-5-338917 JP-A-4-59639 JP-A-2005-75664 JP 2005-97038 A

  When removing abnormal points online during drawing in order to determine the presence or absence of abnormal points and to divide them into small bobbins, it is necessary to cut the optical fiber once and switch the winding when an abnormal part occurs. At the same time, the drawing speed must be reduced. At that time, it takes time to increase the linear velocity again, or the amount of optical fiber to be discarded increases. In addition, when an abnormal part is manually discarded, an incorrect point position input error, an incorrect part and a calculation error before and after the discarding may occur, and the abnormal point is not removed in the next process. May flow out while contained in the product.

  Therefore, for example, it is necessary to store the abnormal part in a computer or the like as in Patent Document 1 and automatically calculate the position of the abnormal part. However, as in the technique of Patent Document 1, information on the position of the abnormal part is simply used. If you just determine the presence or absence of an abnormal part, there is a possibility that the abnormal part may be mixed into a good part due to a measurement error when dividing into small bobbins, and whether the bobbin to be separated next is good or defective It is difficult to determine the length of the optical fiber and how much the winding length is to be determined, and it is difficult to divide the optical fiber into an optimum length corresponding to the small bobbin. In addition, the techniques of Patent Documents 2 to 4 also have a problem that a defective portion is similarly mixed into a good portion, or it is difficult to divide into an optimum length according to a small bobbin.

  An object of the present invention is to provide an optical fiber manufacturing method capable of winding an optical fiber drawn in a drawing process onto a large bobbin, appropriately removing an abnormal portion, and dividing the optical fiber into small bobbins with an optimal length. Is to provide.

The optical fiber manufacturing method of the present invention that can solve the above-described problem is a second method of winding the optical fiber drawn in the drawing step into a small bobbin after the first winding step of winding up the optical fiber drawn into the large bobbin. An optical fiber manufacturing method for performing the winding process of
In the first winding step, the optical fiber is wound while storing the abnormal point information generated in the drawing step in a computer,
In the second winding step, winding is performed based on the winding instruction length to the next small bobbin calculated from the set value according to the type of the small bobbin and the abnormal point information, and the good part is determined to be a good product. The optical fiber is divided while discriminating between a non-defective bobbin that is wound as a defective bobbin that is wound as a defective product with a good part or a defective part ,
The set value according to the type of the small bobbin is the minimum length that is the minimum length of the good part that can be wound as a good bobbin, the full length that is the maximum length of the good part that can be wound as a good bobbin Take up as a good quality bobbin, which is the maximum length that can wind up the length, lower opening defective part and good part as a good bobbin, or can take up the good part and bad part as a bad bobbin It is characterized by using the maximum winding length of the lower defective portion, which is the maximum length of the lower defective portion that can be formed.

  In the optical fiber manufacturing method of the present invention, based on the abnormal point information, it is preferable to calculate the length of the defective portion using the front and rear length of the abnormal point that is the length of the front and rear discarded from the abnormal point during the drawing process. .

  According to the present invention, based on the setting value according to the type of the small bobbin and the abnormal point information, the winding instruction length to the next small bobbin is divided into small bobbins and wound up. It can be appropriately divided into a non-defective bobbin that winds up a good part as a non-defective product and a defective bobbin that winds up a good part or a defective part as a defective product.

It is a figure which shows an example of the manufacturing apparatus used at the drawing process in the manufacturing method of the optical fiber which concerns on this invention. It is a figure which shows an example of the coloring apparatus which performs a rewinding process. It is a schematic diagram which shows an example of the calculation method of the favorable part and defective part based on abnormal point information. It is a calculation flowchart of the winding instruction length by the setting value according to the kind of small bobbin. It is a schematic diagram which calculates winding instruction | indication length by the case 1 selected by the flowchart of FIG. It is a schematic diagram which calculates winding instruction | indication length by the case 2 selected by the flowchart of FIG. It is a schematic diagram which calculates winding instruction | indication length by the case 3 selected by the flowchart of FIG. It is a schematic diagram which calculates winding instruction | indication length by case 4 selected by the flowchart of FIG. It is a schematic diagram which calculates winding instruction | indication length by case 5 selected by the flowchart of FIG. It is a schematic diagram which calculates winding instruction | indication length by case 6 selected by the flowchart of FIG. It is a schematic diagram which calculates winding instruction | indication length by case 7 selected by the flowchart of FIG.

Hereinafter, an example of an embodiment of an optical fiber manufacturing method according to the present invention will be described with reference to the drawings.
First, the drawing process will be described. FIG. 1 shows a schematic configuration of an optical fiber manufacturing apparatus 1. As shown in FIG. 1, an optical fiber manufacturing apparatus 1 includes a heating furnace 2 that heats an optical fiber preform G on the upstream side of an optical fiber travel line. The heating furnace 2 is a cylindrical furnace core tube. 4 and a heating element 3 that is a heater surrounding the furnace core tube 4. By causing the heating element 3 to generate heat, the optical fiber preform G is heated and softened. A gas supply unit 31 is provided in the heating furnace 2, and a purge gas for purging the inside of the heating furnace 2 is supplied.

  The upper part of the optical fiber preform G is gripped by the feeding means 5 and fed into the heating furnace 2 so that the lower end portion is located inside the furnace core tube 4, and is drawn downward to be reduced in diameter. As a result, a glass fiber G1 is formed. A cooling device 6 is provided on the downstream side of the heating furnace 2, and after the glass fiber G1 is cooled, its outer diameter is measured by, for example, a laser beam type outer diameter measuring instrument 7. In addition to measuring the outer diameter, the outer diameter measuring device 7 can also detect a glass outer diameter abnormal portion and a bubble generating portion, and the detection results are appropriately stored in the memory of the computer 15 of the manufacturing apparatus 1. Is done.

  On the downstream side of the outer diameter measuring device 7, a die 8 for applying an ultraviolet curable resin to the glass fiber G1 is provided. Further, on the downstream side of the die 8, there is provided an ultraviolet irradiation device 9 for irradiating the ultraviolet curable resin with ultraviolet rays and curing it. Thereby, the glass fiber G1 becomes an optical fiber G2 in which a primary resin and a secondary resin are applied to the outer peripheral side thereof to form a two-layer coating layer.

  On the downstream side of the ultraviolet irradiation device 9, for example, a laser beam type outer diameter measuring device 10 is provided. In the outer diameter measuring device 10, in addition to measuring the outer diameter, the coated outer diameter abnormal portion, It is also possible to detect a bump (unevenness) generating part, and the detection result is appropriately stored in the memory of the computer 15 of the manufacturing apparatus 1.

  Thereafter, the optical fiber G2 is taken up by the capstan 16 via the roller 11 directly below, and a predetermined tension is applied. The optical fiber G2 taken up by the capstan 16 is wound around the large bobbin 24 via the guide roller 21 and the dancer rollers 22 and 23. As described above, the winding of the large bobbin 24, which is the first winding process, causes the computer 15 to store the abnormal point information (the type of abnormality and the occurrence position in the optical fiber length direction) generated in the drawing process. While done.

  Next, the rewinding process (second winding process) will be described. FIG. 2 shows a coloring device 20 when coloring is performed by forming a colored layer on an optical fiber, and the rewinding step can be performed using the coloring device 20.

In the coloring device 20, the optical fiber G 2 is unwound from the large bobbin 24, passes through the guide roller 25, passes through the coloring die 26 and the ultraviolet irradiation furnace 27, and the colored optical fiber G 3 is taken up by the capstan device 28. . The optical fiber G3 taken by the capstan device 28 is screened by the screening device 29, wound around the small bobbin 30 through the guide roller 25, and divided. The small bobbin 30 is replaced as appropriate.
In addition, although the case where the coloring apparatus 20 is illustrated and wound around the small bobbin 30 is described here, the coloring device 20 may be divided into small bobbins 30 while being wound without being colored. In that case, although the coloring die 26 and the ultraviolet irradiation furnace 27 are not provided in the coloring device 20, the other device configuration is the same as that of the coloring device 20.

  The optical fiber G2 wound and stored on the large bobbin 24 is divided into a plurality of small bobbins 30 and wound, for example, by the coloring device 20 shown in FIG. 2 (second winding step). In this second winding process, the small part was cut into small bobbins based on the set value according to the type of the small bobbin and the abnormal point information stored in the first winding process, and the good part was wound as a good product. The non-defective product bobbin and the defective product bobbin obtained by winding the good part or defective part as a defective product are discriminated while being discriminated. The type of small bobbin refers to the type of bobbin corresponding to the bobbin size, shape, shipping destination, and the like, and the set values such as the minimum length and full winding length are determined depending on the type of small bobbin.

FIG. 3 shows an example of a method for calculating a good part and a defective part based on abnormal point information.
In FIG. 3, the winding lower opening of the large bobbin is the right end, and the winding upper opening is the left end. The abnormal points are as shown in Table 1 below. Of the abnormal points, minor abnormal points that are set unless they are removed depending on the type of abnormal points or the like are not regarded as defective.

Abnormalities 2 and 3 are section abnormalities in which abnormalities have occurred continuously, and abnormal 1 is a point abnormality in which abnormalities have occurred locally. The abnormal part longitudinal length x is added to these abnormal parts as follows.
-If the section is abnormal, subtract x from the winding length at the start point and add x to the winding length at the end point.
・ In case of point abnormality, the starting point is the abnormal point position -x and the end point is the abnormal point position + x.
Note that the front / rear length of the abnormal part is the length of front / rear removal from the abnormal point during the drawing process, and is a value determined in advance in consideration of measurement errors in order to ensure that the abnormal part is included in the defective part. is there. As the distance from the upper mouth becomes longer, the measurement error becomes larger. Therefore, as an example, “x = y (km) + (abnormal point distance from the upper mouth) × z (%)” is calculated.

  As a result of adding the front and back length x of the abnormal part, if the abnormal part overlaps, they are grouped as one defective part, the starting point is the starting point closest to the lowest exit of the included abnormal point, and the end point is included The end point farthest from the abnormal point to be displayed.

The good part and bad part calculated in this way are as shown in Table 2 below.

Also, when rewinding to a small bobbin, the winding length from the top of the large bobbin is specified, so the position of the defective part is converted from the top of the large bobbin for the calculation. It is necessary to keep. The position of the upper end of the large bobbin uses the remaining length of the large bobbin, and the conversion formula is as follows.
(Equivalent distance from the upper entrance) = (Remaining length of large bobbin)-(Distance from the lower entrance of the start point or end point)

Then, the setting value according to the type of each small bobbin and the winding instruction length to the next small bobbin are calculated from the good part and the bad part calculated in this way, and based on these, the small bobbin is transferred to the small bobbin. Take up. FIG. 4 shows an example of a calculation flow of the winding instruction length based on the set value according to the type of the small bobbin.
In the following description, it is described that the good portion wound around the small bobbin has a good overall length from the lower opening, but the extra length for use in the inspection is set to the small bobbin lower opening side (lead winding portion). Etc.) and a defective portion having a fixed length may be wound around the lower opening. Further, the fixed length of the defective portion wound around the lower mouth side may be provided as a set value according to the type of the small bobbin.

  First, the quality of the upper opening of the large bobbin is determined (step S01). If the upper opening is a good part (S01: Yes), it is determined whether or not the length of the good part is not less than the minimum length (step S02). The minimum length here is a set value according to the type of the small bobbin, and is the minimum length of the good portion that can be wound as a good bobbin. If the length of the good portion is not less than the minimum length (S02: Yes), it is determined whether the length of the good portion is not less than the full winding length (step S03). The full winding length here is a set value according to the type of the small bobbin, and is the maximum length of the good portion that can be wound as a good bobbin.

  If the length of the good portion is equal to or greater than the full winding length (S03: Yes), winding is performed based on the winding instruction length of the case 1 as shown in FIG. If so (S03: No), winding is performed based on the winding instruction length of case 2 as shown in FIG. In case 1, the winding instruction length is full, the good part is wound from the upper opening to the full winding, and the small bobbin is shipped as a good bobbin. In case 2, the winding instruction length is the length to the end point of the good part, the good part is wound on the small bobbin from the upper opening to the end point of the good part, and the small bobbin is shipped as a good bobbin.

  In step S02, if the length of the good portion is less than the minimum length (S02: No), winding is performed based on the winding instruction length of case 3 as shown in FIG. In case 3, the winding instruction length reaches the end of the good part, the good part is wound up from the upper opening to the end of the good part, and the length of the good part is less than the minimum length. Are discarded as defective bobbins.

  In step S01, if the upper opening is a defective part (S01: No), it is determined whether or not the length of the defective part is equal to or longer than the maximum winding length of the lower opening defective part (step S04). Note that the lower winding portion maximum winding length here is a set value according to the type of the small bobbin, and is the maximum length of the lower opening defective portion that can be wound as a non-defective bobbin. If the length of the defective portion is equal to or longer than the maximum winding length of the lower defective portion (S04: Yes), it is determined whether or not the length to the starting point of the next good portion is equal to or longer than the total winding length (step). S05). The total winding length referred to here is a set value according to the type of the small bobbin, and the lower opening defective portion and the good portion can be wound as a good bobbin, or the good portion and the defective portion are defective. The maximum length that can be wound as a bobbin.

  If the length to the next good part start point is equal to or greater than the total take-up length (S05: Yes), winding is performed based on the winding instruction length of case 4 as shown in FIG. If the length is less than the total winding length (S05: No), winding is performed based on the winding instruction length of the case 5 as shown in FIG. In case 4, the winding instruction length is the total winding length, the defective portion is wound up from the upper opening to the total winding length on a small bobbin, and the small bobbin is discarded as a defective bobbin. In case 5, the winding instruction length is the length to the next good part starting point, the defective part is wound up from the upper opening to the next good part starting point, and the small bobbin is discarded as a defective bobbin. The

  In step S04, if the length of the defective portion is less than the maximum winding length of the lower opening defective portion (S04: No), it is determined whether or not the length of the next good portion is equal to or greater than the full winding length (step). S06). If the length of the next good portion is equal to or greater than the full winding length (S06: Yes), winding is performed based on the winding instruction length of the case 6 as shown in FIG. If it is less than the full winding length (S06: No), winding is performed based on the winding instruction length of the case 7, as shown in FIG. In case 6, the winding instruction length becomes the full winding length, the defective portion of the upper mouth and the next good portion are wound on the small bobbin from the upper mouth to the full winding length, and the small bobbin includes the defective portion in the lower mouth. Shipped as a good bobbin in the state. In case 7, the winding instruction length is the length to the end point of the good part, and the defective part of the upper mouth and the next good part are wound on the small bobbin from the upper mouth to the end point of the good part. Shipped as a good bobbin with a defective part in its mouth.

  When the winding is performed by any of the cases 1 to 7, the process returns to step S01, and it is determined again from the upper mouth where the large bobbin remains to determine which of the cases 1 to 7, and Repeat until the large bobbin optical fiber is gone. As a result, the optical fiber of the large bobbin is appropriately divided into a non-defective bobbin obtained by winding a good part as a non-defective product and a defective bobbin obtained by winding a good part or a defective part as a defective product.

  Thus, according to the manufacturing method of the optical fiber according to the embodiment, based on the set value according to the type of the small bobbin and the winding instruction length to the next small bobbin calculated from the abnormal point information, Divide into small bobbins and take up. As a result, the abnormal part is appropriately removed from the optical fiber wound around the large bobbin, and it is suitable for the non-defective product bobbin obtained by winding the good part as a good product and the good product or the defective product bobbin taken up as a defective product. Can be divided into

Further, since the defective part is calculated based on the abnormal point information generated in the drawing process by adding the front and rear length of the abnormal part to the abnormal point, it is possible to reliably prevent the abnormal part from being included in the good part. .
Furthermore, since the minimum length, full winding length, total winding length, and maximum winding length of the lower opening defective portion are used as set values according to the small bobbin, the optical fiber is set to an optimum length according to the small bobbin. Can be divided.

  1: optical fiber manufacturing apparatus, 2: heating furnace, 7, 10: outer diameter measuring device, 24: large bobbin, 30: small bobbin, G: optical fiber preform, G1: glass fiber, G2: optical fiber

Claims (2)

An optical fiber manufacturing method for performing a second winding step of winding the optical fiber drawn in the drawing step into a small bobbin after the first winding step of winding the optical fiber on a large bobbin,
In the first winding step, the optical fiber is wound while storing the abnormal point information generated in the drawing step in a computer,
In the second winding step, winding is performed based on the winding instruction length to the next small bobbin calculated from the set value according to the type of the small bobbin and the abnormal point information, and the good part is determined to be a good product. The optical fiber is divided while discriminating between a non-defective bobbin that is wound as a defective bobbin that is wound as a defective product with a good part or a defective part ,
The set value according to the type of the small bobbin is the minimum length that is the minimum length of the good part that can be wound as a good bobbin, the full length that is the maximum length of the good part that can be wound as a good bobbin The length, lower opening defective part and good part can be wound up as a good bobbin, or the good part and bad part can be taken up as a defective bobbin. A method for producing an optical fiber, wherein a maximum winding length of a lower defective portion that is the maximum length of the lower defective portion that can be used is used . An optical fiber manufacturing method according to claim 1,
Based on the abnormal point information, the length of the defective part is calculated using the length before and after the abnormal point, which is the length of the front and rear discarded from the abnormal point during the drawing process.

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