Online casing drawing method and optical fiber

Abstract

The present invention relates to the field of optical fiber production technology, and provides an online sleeve drawing method and optical fiber. The online sleeve drawing method comprises: fusing an extension tube at one end of the sleeve to obtain a first assembly; fusing a prefabricated block at one end of a core rod, and processing the prefabricated block into a positioning block to obtain a second assembly, wherein the positioning block is in the shape of a truncated cone, the diameter of the large diameter end of the positioning block is larger than the inner diameter of the sleeve, and the central axis of the positioning block is collinear with the central axis of the core rod; inserting the second assembly into the first assembly so that the core rod is completely in the sleeve, and the positioning block is clamped in the end opening of the sleeve to obtain a third assembly; installing the third assembly on a drawing tower to perform a drawing operation. The present invention can ensure that the central axis of the core rod is collinear with the central axis of the sleeve, and the prefabricated rod preparation process and the drawing process can be carried out simultaneously, thereby solving the problems of low optical fiber preparation efficiency and poor optical fiber quality caused by core offset in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber production, and in particular to an online sleeve drawing method and an optical fiber. Background Art

[0002] In existing technology, optical fiber preforms consist of two parts: a core and a cladding. These are typically combined and melted together using the sleeve method to form a complete preform. In this method, the core rod is a solid rod, while the sleeve is a hollow tube, serving as the cladding. This method can be performed on a sleeve lathe or a drawing tower.

[0003] When operating in the sleeve workshop, handles must first be welded to the tail ends of the sleeve and the core rod to fix the sleeve and the core rod on both ends of the sleeve lathe. The moving parts at both ends drive the sleeve and the core rod to move relative to each other and rotate. During the relative movement, the core rod is gradually inserted into the sleeve. Subsequently, the sleeve is heated and shrunk to wrap the core rod. The handles on the core rod and the sleeve are cut off to form a preform rod. When drawing, in order to effectively utilize the preform rod, an extension tube with the same outer diameter as the preform rod needs to be welded to the tail end of the preform rod. The extension tube is clamped to avoid waste (because during drawing, the drawing tower needs to fix the preform rod for up and down movement to achieve drawing). This method involves multiple assembly and material transfer processes, resulting in low optical fiber preparation efficiency.

[0004] During the drawing process on the drawing tower, in order to convert all the effective parts of the preform into optical fiber and prevent waste, it is necessary to concentrically fuse the handles at the end of the sleeve and the core rod. To ensure that the sleeve and the core rod are placed concentrically, a positioning component is usually coaxially arranged above the sleeve handle to ensure that the core rod handle and the sleeve handle are concentric after the core rod with the handle is inserted into the sleeve through the positioning component. However, in the actual process of fusing the handles, it is difficult to ensure that the handles connected to the end of the sleeve and the core rod are concentric with the sleeve and the core rod themselves. As a result, although the positioning component can make the core rod handle and the sleeve handle concentric (their central axes are collinear), the core rod may be in a tilted state inside the sleeve, which in turn causes the core of the drawn optical fiber to be offset, which does not meet customer requirements. In addition, the longer the preform is, the more serious the core offset of the optical fiber. Summary of the Invention

[0005] The present invention provides an online sleeve drawing method and an optical fiber, which are used to solve the problems in the prior art of low optical fiber preparation efficiency and poor optical fiber quality caused by optical fiber core deviation.

[0006] In a first aspect, the present invention provides an online casing wire drawing method, comprising:

[0007] An extension pipe is welded to one end of the sleeve to obtain a first assembly;

[0008] A prefabricated block is welded to one end of the mandrel, and the prefabricated block is processed into a positioning block to obtain a second assembly. The positioning block is in the shape of a truncated cone. The end of the positioning block welded to the mandrel is a small-diameter end of the positioning block. The diameter of the small-diameter end is smaller than the inner diameter of the sleeve. The diameter of the large-diameter end of the positioning block is larger than the inner diameter of the sleeve. The diameter of the large-diameter end is smaller than the inner diameter of the extension pipe. The central axis of the positioning block is collinear with the central axis of the mandrel.

[0009] Inserting the second assembly into the first assembly so that the core rod is completely located in the sleeve and the positioning block is clamped in the end opening of the sleeve to obtain a third assembly;

[0010] The third assembly is installed on a drawing tower to perform a drawing operation.

[0011] According to the online sleeve wire drawing method provided by the present invention, the step of processing the prefabricated block into the positioning block includes:

[0012] Rotating the mandrel and the prefabricated block with the central axis of the mandrel as a rotation axis;

[0013] The prefabricated block is cut and polished to obtain the positioning block.

[0014] According to the online sleeve drawing method provided by the present invention, the step of installing the third assembly on the drawing tower includes:

[0015] The extension tube is fixed on the drawing tower so that the sleeve is located below the extension tube and is in a vertical state.

[0016] According to the online casing wire drawing method provided by the present invention, the wire drawing operation further includes:

[0017] The lower end of the third assembly is heated, and at the same time, a vacuum operation is performed on the inside of the sleeve.

[0018] According to the online sleeve wire drawing method provided by the present invention, the vacuuming operation inside the sleeve further includes: welding the contact portion between the positioning block and the sleeve.

[0019] According to the online sleeve wire drawing method provided by the present invention, before inserting the second assembly into the first assembly, it also includes: cutting the positioning block so that when the second assembly is inserted into the first assembly, an exhaust hole is formed between the cutting surface of the positioning block and the inner wall of the sleeve.

[0020] According to the online sleeve wire drawing method provided by the present invention, the step of performing a vacuum operation on the sleeve includes:

[0021] sealing the top opening of the extension tube;

[0022] Insert one end of the vacuum tube into the first assembly to perform vacuuming.

[0023] According to the online sleeve wire drawing method provided by the present invention, a chuck is provided on the top of the exhaust duct, and the chuck blocks the top opening of the extension pipe. The chuck has at least one through hole, and the exhaust duct passes through the through hole and the exhaust hole in sequence, thereby extending into the gap between the sleeve and the core rod.

[0024] According to the online sleeve wire drawing method provided by the present invention, when the positioning block is clamped in the end opening of the sleeve, the center of gravity of the positioning block is located inside the sleeve.

[0025] In a second aspect, the present invention further provides an optical fiber, which is prepared by the online sleeve drawing method as described in any one of the above items.

[0026] The online sleeve drawing method and optical fiber of the present invention obtain a first assembly by fusing an extension tube at one end of the sleeve; then, a prefabricated block is fusing at one end of a core rod, and the prefabricated block is processed into a positioning block so that the central axis of the positioning block is collinear with the central axis of the core rod. The core rod and the positioning block together constitute a second assembly. After the second assembly is inserted into the first assembly, the core rod completely enters the sleeve, and the positioning block can be clamped at the end opening of the sleeve. The first assembly and the second assembly together constitute a third assembly. When the positioning block is clamped at the end opening of the sleeve, the central axis of the positioning block is collinear with the central axis of the sleeve, thereby The central axis of the core rod is made collinear with the central axis of the sleeve, so that when the third assembly is drawn, the core rod will not tilt relative to the sleeve, resulting in unqualified drawn optical fiber; secondly, the third assembly needs to be heated when it is drawn, and the existing sleeve also needs to be heated when it is melted to wrap the core rod to prepare a preform rod. Therefore, the online sleeve drawing method of the present invention can also carry out the preform rod preparation process and the drawing process simultaneously, thereby improving the optical fiber preparation efficiency, saving time and labor costs, and effectively solving the problems of low optical fiber preparation efficiency and poor optical fiber quality caused by the core offset of the optical fiber in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 11 is a schematic flow chart of an online casing wire drawing method provided by an embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of a third assembly provided by an embodiment of the present invention;

[0030] Figure 3 It is a partial top view of the third assembly provided by an embodiment of the present invention.

[0031] Reference numerals:

[0032] 1. Sleeve; 2. Extension pipe; 3. Mandrel; 4. Positioning block; 41. Exhaust hole; 5. Chuck. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0034] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "center", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0037] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0038] The following combination Figures 1 to 3 The invention describes an online sleeve drawing method and an optical fiber.

[0039] like Figures 1 to 3 As shown, an embodiment of the present invention provides an online casing wire drawing method, comprising:

[0040] S100: An extension pipe is welded to one end of the sleeve to obtain a first assembly.

[0041] S200: A prefabricated block is welded to one end of the core rod, and the prefabricated block is processed into a positioning block to obtain a second assembly. The positioning block is in the shape of a truncated cone. The end where the positioning block is welded to the core rod is the small diameter end of the positioning block. The diameter of the small diameter end is smaller than the inner diameter of the sleeve. The diameter of the large diameter end of the positioning block is larger than the inner diameter of the sleeve. The diameter of the large diameter end is smaller than the inner diameter of the extension pipe. The central axis of the positioning block is collinear with the central axis of the core rod.

[0042] S300: inserting the second assembly into the first assembly so that the core rod is completely in the sleeve, and the positioning block is clamped at the end opening of the sleeve to obtain a third assembly.

[0043] S400: Install the third assembly on the drawing tower to perform the drawing operation.

[0044] Specifically, the extension pipe 2 is first welded to one end of the sleeve 1, and the central axis of the sleeve 1 is as collinear as possible with the central axis of the extension pipe 2. The outer diameter of the sleeve 1 is equal to the outer diameter of the extension pipe 2, and the inner diameter of the sleeve 1 is smaller than the inner diameter of the extension pipe 2.

[0045] Furthermore, a prefabricated block is welded to one end of the core rod 3, and then the prefabricated block is processed into a positioning block 4 that meets the requirements. The core rod 3 and the positioning block 4 together constitute a second assembly. Compared with directly welding the positioning block 4 that meets the requirements to the core rod 3, welding the core rod 3 to the prefabricated block first and then processing the prefabricated block can avoid the defects caused by welding. If the positioning block 4 that meets the requirements is directly welded to the core rod 3, it is difficult to ensure that the central axis of the positioning block 4 and the central axis of the core rod 3 are always collinear before and after welding. However, if the core rod 3 and the prefabricated block are first welded and then the prefabricated block is processed, even if the core rod 3 and the prefabricated block are not welded according to the preset relative orientation during welding, the shape of the prefabricated block can still be processed so that the central axis of the positioning block 4 obtained is collinear with the central axis of the core rod 3.

[0046] Furthermore, the second assembly is inserted into the first assembly, and the core rod 3 passes through the interior of the extension tube 2 and completely enters the sleeve 1. Since the diameter of the small diameter end of the positioning block 4 is smaller than the inner diameter of the sleeve 1, and the diameter of the large diameter end is larger than the inner diameter of the sleeve 1, the positioning block 4 only partially enters the sleeve 1, and the positioning block 4 is clamped at the end opening of the sleeve 1. Since the positioning block 4 is in the shape of a truncated cone, the end opening of the existing sleeve 1 is also circular. When the positioning block 4 is clamped at the end opening of the sleeve 1, the positioning block 4 is straightened under the action of the gravity of the positioning block 4 itself and the core rod 3, so that the central axis of the positioning block 4 must be collinear with the central axis of the sleeve 1, and then the central axis of the core rod 3 inside the sleeve 1 is collinear with the central axis of the sleeve 1. The first assembly and the second assembly together constitute a third assembly. The third assembly is installed on the drawing tower for wire drawing.

[0047] The online sleeve wire drawing method of the present invention obtains a first assembly by welding an extension pipe 2 at one end of a sleeve 1; then, a prefabricated block is welded at one end of a core rod 3, and the prefabricated block is processed into a positioning block 4, so that the central axis of the positioning block 4 is collinear with the central axis of the core rod 3, and the core rod 3 and the positioning block 4 together constitute a second assembly. After the second assembly is inserted into the first assembly, the core rod 3 completely enters the sleeve 1, and the positioning block 4 can be clamped at the end opening of the sleeve 1. The first assembly and the second assembly together constitute a third assembly, and when the positioning block 4 is clamped at the end opening of the sleeve 1, the central axis of the positioning block 4 is collinear with the central axis of the sleeve 1. , thereby making the central axis of the core rod 3 and the central axis of the sleeve 1 colinear, so that when the third assembly is drawn, the core rod 3 will not tilt relative to the sleeve 1, resulting in unqualified drawn optical fiber; secondly, the third assembly needs to be heated when it is drawn, and the existing sleeve 1 is melted to wrap the core rod 3 to prepare the preform rod, and it also needs to be heated. Therefore, the online sleeve drawing method of the present invention can also carry out the preform rod preparation process and the drawing process simultaneously, thereby improving the optical fiber preparation efficiency, saving time and labor costs, and effectively solving the problems of low optical fiber preparation efficiency and poor optical fiber quality caused by the core offset of the optical fiber in the prior art.

[0048] like Figure 2 As shown, in some embodiments, when the positioning block 4 is clamped in the end opening of the sleeve 1 , the center of gravity of the positioning block 4 is located inside the sleeve 1 .

[0049] Specifically, the center of gravity of the positioning block 4 is located inside the sleeve 1, which can prevent the positioning block 4 from easily tilting due to an excessively high center of gravity. Optionally, the diameter of the large-diameter end of the positioning block 4 is slightly larger than the inner diameter of the sleeve 1, so that the positioning block 4 is almost completely inside the sleeve 1, making the positioning block 4 more stable and less likely to tilt, ensuring that the central axis of the core rod 3 is always collinear with the central axis of the sleeve 1.

[0050] In some embodiments, the step of processing the prefabricated block into the positioning block 4 includes:

[0051] The core rod 3 and the prefabricated block are rotated with the central axis of the core rod 3 as the rotation axis.

[0052] The prefabricated block is cut and polished to obtain the positioning block 4.

[0053] Specifically, the rotating prefabricated block is cut and ground using cutting and grinding tools, thereby processing the prefabricated block into a truncated cone shape. Since the prefabricated block rotates about the central axis of the core rod 3, the central axis of the positioning block 4 obtained after cutting must be collinear with the central axis of the core rod 3. The shape and size of the prefabricated block should be sufficient to obtain a positioning block 4 that meets the requirements through cutting, grinding, etc. The prefabricated block can be cylindrical or truncated cone-shaped. By selecting this conventional structure as the prefabricated block, the prefabricated block is not only easy to obtain, but also has less material loss when the prefabricated block is processed into the positioning block 4, which helps save costs.

[0054] In some embodiments, the step of installing the third assembly on the drawing tower includes:

[0055] The extension pipe 2 is fixed on the drawing tower so that the sleeve 1 is located below the extension pipe 2 and is in a vertical position.

[0056] Specifically, the drawing tower fixes the entire third assembly by clamping the extension tube 2. The sleeve 1 is located below the extension tube 2, and the sleeve 1 is in a vertical state, so that the gravity direction of the positioning block 4 and the core rod 3 is along the central axis of the sleeve 1, preventing the positioning block 4 from tilting or detaching from the end opening of the sleeve 1; secondly, the vertical state of the sleeve 1 also makes it easier to carry out the wire drawing process. During the wire drawing process, the drawing tower drives the entire third assembly to rise and fall. Since the drawing tower does not clamp the sleeve 1, but clamps the extension tube 2, during the wire drawing process, the entire sleeve 1 together with the core rod 3 inside the sleeve 1 can be used for wire drawing, without causing loss and avoiding waste.

[0057] In some embodiments, the wire drawing operation is performed, and the process also includes:

[0058] The lower end of the third assembly is heated, and at the same time, a vacuum operation is performed on the inside of the sleeve 1.

[0059] Specifically, before drawing, the third assembly is driven up and down by the drawing tower, so that the lower end of the third assembly is extended into the heating furnace for heating, thereby turning the lower end of the sleeve 1 and the lower end of the core rod 3 into a molten state. At the same time, the interior of the sleeve 1 is vacuumed, so that the interior of the sleeve 1 is under negative pressure. Under the negative pressure, the molten sleeve 1 will shrink inward, thereby wrapping the core rod 3 to form a molten preform rod. The molten preform rod is drawn to obtain an optical fiber. Secondly, the vacuum operation can also prevent bubbles from appearing inside the preform rod. It should be noted that the above-mentioned heating and vacuuming processes continue until the end of the drawing process.

[0060] In some embodiments, the vacuuming operation is performed on the sleeve 1 , and before that, the step further includes: welding the contact portion between the positioning block 4 and the sleeve 1 .

[0061] Specifically, while the inside of the sleeve 1 is being vacuumed, the lower ends of the sleeve 1 and the core rod 3 are both in a molten state. By fusing the contact portion of the positioning block 4 with the sleeve 1, the core rod 3 is prevented from swinging due to the pressure difference inside and outside the sleeve 1. This prevents the core rod 3 from swinging up and down, resulting in the core-to-clad ratio of the drawn optical fiber being different from the preset value, and also prevents the core rod 3 from tilting, resulting in the quality of the finally drawn optical fiber being unqualified.

[0062] like Figures 2 to 3 As shown, in some embodiments, before the second assembly is inserted into the first assembly, the method further includes: cutting the positioning block 4 so that when the second assembly is inserted into the first assembly, an air extraction hole 41 is formed between the cutting surface of the positioning block 4 and the inner wall of the sleeve 1.

[0063] Specifically, the two opposite sides of the positioning block 4 are cut, and the cutting direction is along the axial direction of the positioning block 4. When the second assembly is inserted into the first assembly, two exhaust holes 41 with the same structure are formed between the two cutting surfaces of the positioning block 4 and the inner wall of the sleeve 1. By constructing the exhaust holes 41, the vacuum operation inside the sleeve 1 is facilitated.

[0064] In some embodiments, the step of performing a vacuum operation on the cannula 1 includes:

[0065] Seal the top opening of the extension pipe 2.

[0066] Insert one end of the vacuum tube into the first assembly to perform vacuuming.

[0067] Specifically, the top opening of the extension tube 2 is first sealed to prevent outside air from entering the first assembly. An air extraction conduit is then inserted into the first assembly. The other end of the air extraction conduit is connected to a vacuum pump or other vacuum extraction component, which extracts air from the first assembly. It should be noted that since the extension tube 2 and the cannula 1 are connected via the air extraction hole 41, in this embodiment, the air extraction conduit can be inserted into either the extension tube 2 or the cannula 1.

[0068] like Figure 2 As shown, in some embodiments, a chuck 5 is provided at the top of the exhaust duct, which blocks the top opening of the extension tube 2. The chuck 5 has at least one through hole, and the exhaust duct passes through the through hole and the exhaust hole 41 in sequence, thereby extending into the gap between the sleeve 1 and the core rod 3.

[0069] Specifically, there are two through holes on the chuck 5, and there are also two exhaust tubes. One exhaust tube passes through one of the through holes and one of the exhaust holes 41 in sequence, and the other exhaust tube passes through the other through hole and the other exhaust hole 41 in sequence. Vacuuming is performed jointly by the two exhaust tubes, which can improve efficiency.

[0070] Furthermore, although the air pressure in the extension tube 2 and the sleeve 1 will decrease when vacuum is drawn, the air extraction tube extends into the sleeve 1 and directly extracts the air in the sleeve 1, which will cause the air pressure in the sleeve 1 to be lower than the air pressure in the extension tube 2. Under the action of the air pressure difference, the positioning piece will be firmly pressed at the end opening of the sleeve 1, which helps prevent the positioning block 4 from shaking.

[0071] Furthermore, when the exhaust duct passes through the through hole, the outer wall of the exhaust duct fits tightly against the inner wall of the through hole to prevent air from flowing through the gap between the exhaust duct and the inner wall of the through hole. The gap between the exhaust duct and the inner wall of the through hole can also be sealed by providing a gasket or other sealing means.

[0072] The present invention also provides an optical fiber, which is prepared by the online sleeve 1 drawing method in any of the above embodiments.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An online casing wire drawing method, characterized in that: include: An extension pipe is welded to one end of the sleeve to obtain a first assembly; A prefabricated block is welded to one end of the mandrel, and the prefabricated block is processed into a positioning block to obtain a second assembly. The positioning block is in the shape of a truncated cone. The end of the positioning block welded to the mandrel is a small-diameter end of the positioning block. The diameter of the small-diameter end is smaller than the inner diameter of the sleeve. The diameter of the large-diameter end of the positioning block is larger than the inner diameter of the sleeve. The diameter of the large-diameter end is smaller than the inner diameter of the extension pipe. The central axis of the positioning block is collinear with the central axis of the mandrel. Inserting the second assembly into the first assembly so that the core rod is completely located in the sleeve and the positioning block is clamped in the end opening of the sleeve to obtain a third assembly; The third assembly is installed on a drawing tower to perform a drawing operation.

2. The online sleeve wire drawing method according to claim 1, characterized in that: The step of processing the prefabricated block into the positioning block comprises: Rotating the mandrel and the prefabricated block with the central axis of the mandrel as a rotation axis; The prefabricated block is cut and polished to obtain the positioning block.

3. The online sleeve wire drawing method according to claim 1, characterized in that: The step of installing the third assembly on the drawing tower includes: The extension tube is fixed on the drawing tower so that the sleeve is located below the extension tube and is in a vertical state.

4. The online sleeve wire drawing method according to claim 3, characterized in that: The wire drawing operation further includes: The lower end of the third assembly is heated, and at the same time, a vacuum operation is performed on the inside of the sleeve.

5. The online sleeve wire drawing method according to claim 4, characterized in that: The vacuuming operation inside the sleeve also includes: welding the contact portion between the positioning block and the sleeve.

6. The online sleeve wire drawing method according to claim 4, characterized in that: Before inserting the second assembly into the first assembly, the method further includes: cutting the positioning block so that when the second assembly is inserted into the first assembly, an air extraction hole is formed between the cutting surface of the positioning block and the inner wall of the sleeve.

7. The online sleeve wire drawing method according to claim 6, characterized in that: The step of performing a vacuum operation on the casing includes: sealing the top opening of the extension tube; Insert one end of the vacuum tube into the first assembly to perform vacuuming.

8. The online sleeve wire drawing method according to claim 7, characterized in that: A chuck is provided at the top of the exhaust duct, which blocks the top opening of the extension tube. The chuck has at least one through hole, and the exhaust duct passes through the through hole and the exhaust hole in sequence, thereby extending into the gap between the sleeve and the core rod.

9. The online sleeve wire drawing method according to any one of claims 1 to 8, characterized in that: When the positioning block is clamped in the end opening of the sleeve, the center of gravity of the positioning block is located in the sleeve.

10. An optical fiber, characterized in that: The optical fiber is prepared by the online sleeve drawing method according to any one of claims 1 to 9.

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