Preparation method of optical fiber core layer

Abstract

The invention provides a preparation method of an optical fiber core layer, an optical fiber comprises a deposition tube, a head tube and a tail tube, and the preparation method comprises the following steps: respectively fixing the head tube and the tail tube at two ends of a deposition lathe through a clamp; a deposition pipe is placed between the head pipe and the tail pipe, a concentric part is placed at the position corresponding to the deposition pipe, and the head pipe, the deposition pipe and the tail pipe are arranged along the same axis through the concentric part; at least one of the opposite ends of the head pipe and the deposition pipe is heated, so that the head pipe and the deposition pipe are welded; at least one of the opposite ends of the tail pipe and the deposition pipe is heated, so that the tail pipe and the deposition pipe are welded; and after the head pipe, the deposition pipe and the tail pipe are welded, a core layer is formed on the head pipe, the deposition pipe and the tail pipe. The concentric parts are arranged in the deposition pipe welding process, so that the deposition pipe, the head pipe and the tail pipe can be kept concentric after being welded, a core layer is deposited uniformly, and the quality of the optical fiber preform is improved.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber preparation, and in particular to a method for preparing an optical fiber core layer. Background Art

[0002] Optical fiber, full name optical fiber, is a fiber made of glass or plastic. Optical fiber is mainly composed of core layer (fiber core), cladding and coating layer. The specific preparation process is: first, the core layer is deposited in the deposition tube by MCVD or PCVD method, and then the deposition tube is melted into a core rod. According to the requirements of the fiber core-to-clad ratio, a sleeve of a certain thickness is placed on the core rod to further melt the core rod and the sleeve into a preform rod. The qualified preform rod is placed on the drawing tower for drawing. During the drawing process, the outer surface of the filament will be evenly coated with the inner coating and coating layer to form an optical fiber. The cladding of the double-clad optical fiber is divided into an inner cladding and an outer cladding. The deposition tube and the sleeve together constitute the inner cladding of the optical fiber, and the inner coating is the outer cladding of the optical fiber; the deposition tube and the sleeve of the single-clad optical fiber together constitute the cladding of the optical fiber.

[0003] During the core layer deposition process, the head tube and tail tube need to be welded at both ends of the deposition tube. First, it is convenient to connect the deposition tube to the fixtures at both ends of the deposition lathe, and second, it can effectively utilize the preform rods to avoid waste. The head tube, deposition tube and tail tube need to be set concentrically to ensure that the deposition tube is in a horizontal position so that the core layer can be deposited evenly. At the same time, the temperature of the outer wall of the deposition tube needs to be detected during the deposition process. The horizontal placement of the deposition tube can also improve the temperature accuracy detected by the detection head, so that the deposition temperature can be accurately adjusted according to needs during the deposition process to improve the quality of the core layer.

[0004] In the prior art, the deposition tube, head tube and tail tube need to be manually welded on a deposition lathe. Due to certain errors in manual operation (such as hand shaking, deviation in the concentric position of the three tubes, etc.), the deposition tube, head tube and tail tube are not welded concentrically, resulting in uneven core layer deposition, affecting the quality of the preform rod, making the optical fiber quality unable to meet customer requirements, and causing economic losses. Summary of the invention

[0005] The present invention provides a method for preparing an optical fiber core layer, which is used to solve the problem that in the existing optical fiber preparation process, the error in manual fusion splicing causes the fusion splicing of the deposition tube, the head tube and the tail tube of the optical fiber to be unequal, thereby causing uneven core layer deposition and affecting the quality of the preform.

[0006] The present invention provides a method for preparing an optical fiber core layer. The optical fiber comprises a deposition tube, a head tube and a tail tube. The preparation method comprises the following steps: Step 1, fixing the head pipe and the tail pipe at two ends of a deposition lathe by means of a clamp respectively; Step 2, placing the deposition tube between the head tube and the tail tube, and placing a concentric component at a position corresponding to the deposition tube, so that the head tube, the deposition tube and the tail tube are arranged along the same axis through the concentric component; Step 3, heating at least one of the opposite ends of the head tube and the deposition tube to weld the head tube and the deposition tube; Step 4, heating at least one of the opposite ends of the tail pipe and the deposition tube to weld the tail pipe and the deposition tube; Step 5: After the head pipe, the deposition pipe and the tail pipe are fused, a core layer is formed on the head pipe, the deposition pipe and the tail pipe.

[0007] According to a method for preparing an optical fiber core layer provided by the present invention, in the step 2, the deposition tube is fixed on the deposition lathe by the concentric component, the concentric component includes a base, two supports and two half-buckle clamps, the base is installed on the deposition lathe, the two supports are vertically arranged on the base and are respectively located on opposite sides of the base; the two half-buckle clamps are respectively arranged on the top of the two supports, and the deposition tube is clamped on the concentric component by the two half-buckle clamps.

[0008] According to a method for preparing an optical fiber core layer provided by the present invention, a plurality of scaled slide grooves are provided on the base, the plurality of slide grooves extend along the length direction and the width direction of the base respectively, the slide grooves extending along the length direction and the width direction of the base are arranged crosswise with each other, the two supports are slidably installed in the slide grooves, and the heights of the two supports in the vertical direction are adjustable; Among them, the step of arranging the head pipe, the deposition tube and the tail pipe along the same axis through the concentric components in step 2 includes: adjusting the positions of the two supports in the slide groove to adjust the position of the deposition tube relative to the head pipe and the tail pipe in the horizontal direction; and / or adjusting the heights of the two supports to adjust the position of the deposition tube relative to the head pipe and the tail pipe in the vertical direction, so that the head pipe, the deposition tube and the tail pipe are arranged along the same axis.

[0009] According to a method for preparing an optical fiber core layer provided by the present invention, the two half-buckle rings are rotatably connected to the two supports respectively, the clamp is rotatably connected to the deposition lathe, and the half-buckle ring is used to drive the deposition tube to rotate and keep rotating in the same direction and speed as the clamp.

[0010] According to a method for preparing an optical fiber core layer provided by the present invention, the diameters of the two half-buckle rings are adjustable, and the contact surfaces between the inner sides of the two half-buckle rings and the deposition tube are both soft contact surfaces.

[0011] According to a method for preparing an optical fiber core layer provided by the present invention, each of the half-buckle clamps is composed of two identical half rings, one end of the two half rings are movably connected, and the other end of the two half rings can be locked or opened by a buckle.

[0012] According to a method for preparing an optical fiber core layer provided by the present invention, in step 1, the two clamps respectively clamp and fix the opposite ends of the head tube and the tail tube at the two ends of the deposition lathe, and the head tube and the tail tube are arranged along the same axis.

[0013] According to a method for preparing an optical fiber core layer provided by the present invention, in step 3, after heating at least one of the opposite ends of the head tube and the deposition tube and before welding the head tube and the deposition tube, the method further comprises the following steps: expanding the heated ends to be expanded in the head tube and the deposition tube; and / or,

[0014] In step 4, after heating at least one of the opposite ends of the tail pipe and the deposition tube and before welding the tail pipe and the deposition tube, the step of expanding the heated ends of the tail pipe and the deposition tube to be expanded is also included.

[0015] According to a method for preparing an optical fiber core layer provided by the present invention, in the step 3, when the flaring operation is performed, at least one of the head tube and the deposition tube that needs to be flared rotates at a constant speed on the deposition lathe; when the fusion operation is performed, the head tube and the deposition tube both rotate at a constant speed on the deposition lathe; In step 4, when the flaring operation is performed, at least one of the tail pipe and the deposition tube that needs to be flared rotates at a constant speed on the deposition lathe; when the welding operation is performed, both the tail pipe and the deposition tube rotate at a constant speed on the deposition lathe.

[0016] According to a method for preparing an optical fiber core layer provided by the present invention, in step 3, the step of fusing the head tube and the deposition tube comprises: heating at least one of the opposite ends of the head tube and the deposition tube to a molten state, and then contact-fusing the opposite ends of the head tube and the deposition tube; In step 4, the step of welding the tail pipe and the deposition tube includes: heating at least one of the opposite ends of the tail pipe and the deposition tube to a molten state, and then contact welding the opposite ends of the tail pipe and the deposition tube.

[0017] The above technical solution of the present invention has the following beneficial effects: The preparation method of the optical fiber core layer provided by the present invention, by arranging a concentric component at the position below the deposition tube during the deposition tube fusion process, the concentric component can keep the deposition tube, the head tube and the tail tube concentric after fusion, and can avoid the problem of unequal fusion of the deposition tube, the head tube and the tail tube due to manual operation errors (such as hand shaking, observation deviation), and this high degree of concentricity ensures that the core layer material can be evenly distributed on the tube wall of the deposition tube, the head tube and the tail tube during the deposition process, avoiding the quality fluctuation caused by uneven deposition, and significantly improving the uniformity and consistency of the core layer. Since the uniformity of the core layer deposition is significantly improved, the prepared optical fiber preform is also more uniform in structure, reducing internal defects and stress concentration points, thereby improving the overall quality of the optical fiber preform. This high-quality preform can significantly reduce the adverse factors such as attenuation and dispersion of the optical fiber when it is subsequently drawn into an optical fiber, improve the transmission performance of the optical fiber, and meet the customer's demand for high-quality optical fiber; at the same time, it also reduces the fiber unqualified rate, reduces rework and waste caused by quality problems, and thus significantly reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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 creative work.

[0019] Figure 1 It is a flow chart of a method for preparing an optical fiber core layer provided by an embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram of an optical fiber core layer deposition operation platform provided in an embodiment of the present invention.

[0021] Figure 3 It is a schematic diagram of the base structure of the concentric components provided in an embodiment of the present invention.

[0022] Figure 4 is a cross-sectional schematic diagram of a flaring component provided by an embodiment of the present invention; Figure 5 It is a front view of the first conical cylinder or the second conical cylinder of the flaring component provided in an embodiment of the present invention.

[0023] Reference numerals: 1: head pipe; 2: flared end of head pipe; 3: tail pipe; 4: flared end of tail pipe; 5: deposition tube; 6: first clamp; 7: second clamp; 8: base; 9: first support; 10: second support; 11: first half-buckle; 12: second half-buckle; 13: first buckle; 14: second buckle; 15, first conical column; 16, second conical column; 17, handle; 18, first handle slot; 19, second handle slot; 20, third handle slot; 100, flaring component; 801: slide groove. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Combine the following Figure 1-Figure 5 The method for preparing the optical fiber core layer of the present invention is described in detail. Figure 1 is a flow chart of the method for preparing the optical fiber core layer provided by the present invention, Figure 2 Schematic diagram of the optical fiber core layer deposition operation platform provided by the present invention. Figure 1 As shown, the method for preparing the optical fiber core layer of the present invention comprises the following steps: Step 1, fix the head pipe 1 and the tail pipe 3 on both ends of the deposition lathe by means of a clamp; Step 2, placing the deposition tube 5 between the head tube 1 and the tail tube 3, and placing a concentric component at the position corresponding to the deposition tube 5, so that the head tube 1, the deposition tube 5 and the tail tube 3 are arranged along the same axis through the concentric component; Step 3, heating at least one of the opposite ends of the head pipe 1 and the deposition tube 5 to weld the head pipe 1 and the deposition tube 5; Step 4, heating at least one of the opposite ends of the tail pipe 3 and the deposition tube 5 to weld the tail pipe 3 and the deposition tube 5; Step 5: After the head pipe 1 , the deposition pipe 5 and the tail pipe 3 are fused, a core layer is formed on the head pipe 1 , the deposition pipe 5 and the tail pipe 3 .

[0026] It should be noted that the opposite ends of the head pipe 1 and the deposition tube 5 refer to one end of the head pipe 1 close to (or facing) the deposition tube 5 and one end of the deposition tube 5 close to (or facing) the head pipe 1; similarly, the opposite ends of the tail pipe 3 and the deposition tube 5 refer to one end of the tail pipe 3 close to (or facing) the deposition tube 5 and one end of the deposition tube 5 close to (or facing) the tail pipe 3.

[0027] Specifically, in this embodiment, the fixture includes a first fixture 6 and a second fixture 7, and the first fixture 6 and the second fixture 7 are respectively arranged at two ends of the deposition lathe. In step 1, the first fixture 6 and the second fixture 7 respectively clamp and fix the opposite ends of the head pipe 1 and the tail pipe 3 (i.e., the ends of the head pipe 1 and the tail pipe 3 that are away from each other), and the head pipe 1 and the tail pipe 3 are arranged along the same axis.

[0028] In step 2, the deposition tube 5 is fixed on the deposition lathe by a concentric component. Specifically, the concentric component can be arranged below the deposition tube 5. The concentric component includes a base 8, two supports (i.e., a first support 9 and a second support 10) and two half-buckle rings (i.e., a first half-buckle ring 11 and a second half-buckle ring 12). The base 8 is installed on the deposition lathe, and the first support 9 and the second support 10 are both vertically arranged on the base 8 and are respectively located on opposite sides of the base 8. The first half-buckle ring 11 and the second half-buckle ring 12 are respectively arranged on the top of the first support 9 and the second support 10, and the deposition tube 5 is clamped on the concentric component by the first half-buckle ring 11 and the second half-buckle ring 12.

[0029] Combination Figure 2 and Figure 3 As shown, the base 8 is provided with a plurality of graduated slide grooves 801, which extend along the length direction and the width direction of the base 8 respectively, and the slide grooves 801 extending along the length direction and the width direction of the base 8 are arranged crosswise with each other, and the first support 9 and the second support 10 are both slidably installed in the slide grooves 801, and the first support 9 and the second support 10 can move forward, backward, left and right on the base 8 through the slide grooves 801. In addition, the height of the first support 9 and the second support 10 in the vertical direction is adjustable. Among them, the height adjustment method of the first support 9 and the second support 10 is not limited here.

[0030] Specifically, in step 2, the step of arranging the head pipe 1, the deposition tube 5 and the tail pipe 3 along the same axis through concentric components includes: adjusting the positions of the first support 9 and the second support 10 in the slide groove 801, thereby adjusting the position of the deposition tube 5 relative to the head pipe 1 and the tail pipe 3 in the horizontal direction; and / or adjusting the height of the first support 9 and the second support 10, thereby adjusting the position of the deposition tube 5 relative to the head pipe 1 and the tail pipe 3 in the vertical direction, so that the head pipe 1, the deposition tube 5 and the tail pipe 3 can be arranged along the same axis, thereby avoiding the problem of unequal welding of the deposition tube, the head pipe and the tail pipe due to errors such as manual visual operation.

[0031] Furthermore, the first half-buckle clamp 11 and the second half-buckle clamp 12 are rotatably connected to the first support 9 and the second support 10 respectively, the first clamp 6 and the second clamp 7 are rotatably connected to the deposition lathe respectively, the first half-buckle clamp 11 and the second half-buckle clamp 12 are both used to clamp the deposition tube 5 and jointly drive the deposition tube 5 to rotate, and the first clamp 6 and the second clamp 7 are respectively used to drive the head pipe 1 and the tail pipe 3 to rotate.

[0032] Furthermore, the diameters of the first half buckle type snap ring 11 and the second half buckle type snap ring 12 are adjustable. Specifically, each half buckle type snap ring is composed of two identical half rings, which are buckled relative to each other, wherein one end of the two half rings is movably connected, and the other end of the two half rings can be locked or opened by a buckle (the first buckle 13 or the second buckle 14).

[0033] In the above step 2, after placing the concentric components under the deposition tube 5, first adjust the inner diameters of the first half buckle snap ring 11 and the second half buckle snap ring 12 to make them the same as the diameter of the deposition tube 5; then open the first half buckle snap ring 11 and the second half buckle snap ring 12, place the deposition tube 5 in the first half buckle snap ring 11 and the second half buckle snap ring 12, close the first half buckle snap ring 11 and the second half buckle snap ring 12, and fix the first half buckle snap ring 11 through the first buckle 13 and the second buckle 14. and locked with the second half-buckle clamp 12; then, by adjusting the height and position of the first support 9 and the second support 10, the head pipe 1, the deposition tube 5 and the tail pipe 3 are placed concentrically; finally, the rotation direction and rotation speed of the first half-buckle clamp 11 and the second half-buckle clamp 12 are set through the control system, so that the first half-buckle clamp 11 and the second half-buckle clamp 12 drive the deposition tube 5 to rotate in the same direction and rotation speed as the first clamp 6 and the second clamp 7 during the welding operation.

[0034] Furthermore, the control system is connected to the driving components of the first half-buckle clasp 11 and the second half-buckle clasp 12 and the driving components of the first clamp 6 and the second clamp 7, so as to control the first half-buckle clasp 11 and the second half-buckle clasp 12 to rotate in the same direction and speed as the first clamp 6 and the second clamp 7 at both ends of the deposition lathe, thereby ensuring that the deposition tube 5, the head tube 1, and the tail tube 3 rotate in the same direction and speed, further improving the concentricity of the three-tube welding.

[0035] In one embodiment, the contact surfaces between the inner sides of the first half-buckle clasp 11 and the second half-buckle clasp 12 and the deposition tube 5 are both soft contact surfaces, so as to avoid damage to the deposition tube 5 when the first half-buckle clasp 11 and the second half-buckle clasp 12 contact the deposition tube 5.

[0036] In one embodiment, after heating at least one of the opposite ends of the head pipe 1 and the deposition tube 5 and before welding the head pipe 1 and the deposition tube 5, the above step 3 further includes the following steps: expanding the heated ends of the head pipe 1 and the deposition tube 5 to be expanded so that the head pipe 1 and the deposition tube 5 can be better welded.

[0037] Specifically, the step of expanding the heated ends of the head pipe 1 and the deposition tube 5 to be expanded includes: using an expanding component to expand the heated ends of the head pipe 1 and the deposition tube 5 to be expanded, so that the diameters of the two ends of the head pipe 1 and the deposition tube 5 that are close to each other are the same.

[0038] It is understandable that the diameters of the head tube, deposition tube and tail tube are not necessarily the same. The purpose of the expansion operation is to make the two tubes that are fused to each other maintain the same diameter at the fusion point, so as to better complete the fusion and improve the uniformity of the core layer deposition. The expansion operation can be to expand the smaller diameter of the two adjacent tubes, or to expand both adjacent tubes, which is not limited here.

[0039] Combination Figure 4 and Figure 5 As shown, the flaring part of the flaring component 100 is cone-shaped. Specifically, the flaring component 100 includes a first conical cylinder 15, a second conical cylinder 16 and a handle 17. The diameters of the first conical cylinder 15 and the second conical cylinder 16 are different, and the bottoms of the first conical cylinder 15 and the second conical cylinder 16 are fixedly connected at a preset angle. The first conical cylinder 15 and the second conical cylinder 16 are respectively provided with a first handle slot 18 and a second handle slot 19 at the center of the bottom, and a third handle slot 20 is provided at the bottom of the connection between the first conical cylinder 15 and the second conical cylinder 16. The handle 17 is connected to the first conical cylinder 15 and / or the second conical cylinder 16 through one of the first handle slot 18, the second handle slot 19 and the third handle slot 20. Of course, in other embodiments, the handle 17 can also be connected to the first conical cylinder 15 and / or the second conical cylinder 16 in other ways.

[0040] Combination Figure 2 , Figure 4 and Figure 5 As shown, the steps of using the expanding component 100 to expand the heating ends to be expanded in the head pipe 1 and the deposition tube 5 include: inserting the top end of the first conical column 15 or the second conical column 16 of the expanding component 100 into the heating ends to be expanded of the head pipe 1 and / or the deposition tube 5, so that the heating ends to be expanded form corresponding expanded ends.

[0041] Specifically, when the top end of the first conical cylinder 15 is inserted into the heating end of the head tube 1 and / or the deposition tube 5 to be expanded, the handle 17 is fixed to the first conical cylinder 15 through the first handle clamping groove 18, and the handle 17 is coaxially arranged with the first conical cylinder 15. When the top end of the second conical cylinder 16 is inserted into the heating end of the head tube 1 and / or the deposition tube 5 to be expanded, the handle 17 is fixed to the second conical cylinder 16 through the second handle clamping groove 19, and the handle 17 is coaxially arranged with the second conical cylinder 16.

[0042] Among them, when the flaring operation is performed, at least one of the head pipe 1 and the deposition tube 5 that needs to be flared rotates at a uniform speed on the deposition lathe, and the end of the head pipe 1 and the deposition tube 5 that needs to be flared is heated by the lathe heating flame torch. When the end of the head pipe 1 and the deposition tube 5 that needs to be flared is in a molten state, the flaring operation is performed to form a uniformly symmetrical flared end.

[0043] From the perspective of saving process and simplifying the manufacturing process, when the diameters of the head tube 1 and the deposition tube 5 are different, the one with the smaller diameter can be expanded. For example, when the diameter of the head tube 1 is smaller than the diameter of the deposition tube 5, before the head tube 1 and the deposition tube 5 are welded, the end of the head tube 1 close to the deposition tube 5 is expanded as needed to form the expanded end 2 of the head tube, so that the diameter of the expanded end 2 of the head tube is consistent with the diameter of the opposite side of the deposition tube 5, so that the head tube 1 and the deposition tube 5 can be better welded.

[0044] And / or, after heating at least one of the opposite ends of the tail pipe 3 and the deposition tube 5 and before welding the tail pipe 3 and the deposition tube 5, the above step 4 further includes the following steps: expanding the heated ends of the tail pipe 3 and the deposition tube 5 to be expanded so that the tail pipe 3 and the deposition tube 5 can be better welded.

[0045] Specifically, the step of expanding the heated ends of the tail pipe 3 and the deposition tube 5 to be expanded includes: using an expanding component to expand the heated ends of the tail pipe 3 and the deposition tube 5 to be expanded so that the diameters of the two ends of the tail pipe 3 and the deposition tube 5 close to each other are the same.

[0046] Combination Figure 2 , Figure 4 and Figure 5 As shown, the steps of using the expanding component 100 to expand the heating ends to be expanded in the tail pipe 3 and the deposition tube 5 include: inserting the top end of the first conical column 15 or the second conical column 16 of the expanding component 100 into the heating ends to be expanded in the tail pipe 3 and / or the deposition tube 5, so that the heating ends to be expanded form corresponding expanded ends.

[0047] Specifically, when the top end of the first conical cylinder 15 is inserted into the heating end of the tail pipe 3 and / or the deposition tube 5 to be expanded, the handle 17 is fixed to the first conical cylinder 15 through the first handle slot 18, and the handle 17 is coaxially arranged with the first conical cylinder 15. When the top end of the second conical cylinder 16 is inserted into the heating end of the tail pipe 3 and / or the deposition tube 5 to be expanded, the handle 17 is fixed to the second conical cylinder 16 through the second handle slot 19, and the handle 17 is coaxially arranged with the second conical cylinder 16.

[0048] When the expansion operation is performed, at least one of the tail pipe 3 and the deposition tube 5 that needs to be expanded rotates at a uniform speed on the deposition lathe, and the end of the tail pipe 3 and the deposition tube 5 that needs to be expanded is heated by the lathe heating flame torch. When the end of the tail pipe 3 and the deposition tube 5 that needs to be expanded is in a molten state, the expansion operation is performed to form a uniformly symmetrical expanded end.

[0049] From the perspective of saving process and simplifying the manufacturing process, when the diameters of the tail pipe 3 and the deposition tube 5 are different, the one with the smaller diameter can be expanded. For example, when the diameter of the tail pipe 3 is smaller than the diameter of the deposition tube 5, before the tail pipe 3 and the deposition tube 5 are welded, the end of the tail pipe 3 close to the deposition tube 5 is expanded as needed to form the tail pipe expanded end 4, so that the tail pipe 3 and the deposition tube 5 can be better welded.

[0050] Further, step 3, based on the above embodiments, comprises the step of welding the head pipe 1 and the deposition tube 5, comprising: heating at least one of the opposite ends of the head pipe 1 and the deposition tube 5 to a molten state by a lathe heating flame torch, and then contact welding the opposite ends of the head pipe 1 and the deposition tube 5. When the welding operation is performed, the head pipe 1 and the deposition tube 5 are both rotated at a constant speed on the deposition lathe.

[0051] Exemplarily, the flared end 2 of the head pipe (or the end of the head pipe 1 close to the deposition tube 5) is heated by a lathe heating flame torch, and when the flared end 2 of the head pipe (or the end of the head pipe 1 close to the deposition tube 5) is in a molten state, it is contact-welded with the deposition tube 5.

[0052] Step 4 Based on the above embodiments, the step of welding the tail pipe 3 and the deposition tube 5 includes: heating at least one of the opposite ends of the tail pipe 3 and the deposition tube 5 to a molten state by a lathe heating flame torch, and then contact welding the opposite ends of the tail pipe 3 and the deposition tube 5. When the welding operation is performed, the tail pipe 3 and the deposition tube 5 are both rotated at a constant speed on the deposition lathe.

[0053] Exemplarily, the flared end 4 of the tail pipe (or the end of the tail pipe 3 close to the deposition tube 5) is heated by a lathe heating flame torch, and when the flared end 4 of the tail pipe (or the end of the tail pipe 3 close to the deposition tube 5) is in a molten state, it is contact-welded with the deposition tube 5.

[0054] The method for preparing the optical fiber core layer provided by the present invention can avoid the problem of non-concentricity of the deposition tube, the head tube and the tail tube due to manual operation by setting a concentric component during the deposition tube fusion process, and can keep the deposition tube, the head tube and the tail tube concentric after fusion, so as to make the core layer deposition uniform, improve the quality of the preform rod, reduce the optical fiber failure rate, and save costs. In addition, the concentric component has the advantages of portability, height and position adjustment, can clamp deposition tubes of different specifications, can make the deposition tube rotate synchronously with the head tube and the tail tube, and is convenient for the head tube, the deposition tube and the tail tube to keep concentric when they are fused. When multiple tubes need to be fused concentrically or other concentric operations are performed, the concentric component can be used, and it has good adaptability in the optical fiber preparation process.

[0055] 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 embodiments of the present invention.

Claims

1. A method for preparing an optical fiber core layer, characterized in that: The optical fiber comprises a deposition tube, a head tube and a tail tube, and the preparation method comprises the following steps: Step 1, fixing the head pipe and the tail pipe at two ends of a deposition lathe by means of a clamp respectively; Step 2, placing the deposition tube between the head tube and the tail tube, and placing a concentric component at a position corresponding to the deposition tube, so that the head tube, the deposition tube and the tail tube are arranged along the same axis through the concentric component; Step 3, heating at least one of the opposite ends of the head tube and the deposition tube to weld the head tube and the deposition tube; Step 4, heating at least one of the opposite ends of the tail pipe and the deposition tube to weld the tail pipe and the deposition tube; Step 5: After the head pipe, the deposition pipe and the tail pipe are fused, a core layer is formed on the head pipe, the deposition pipe and the tail pipe.

2. The method for preparing an optical fiber core layer according to claim 1, characterized in that: In step 2, the deposition tube is fixed on the deposition lathe through the concentric component, and the concentric component includes a base, two supports and two half-buckle clamps. The base is installed on the deposition lathe, and the two supports are vertically arranged on the base and are respectively located on opposite sides of the base; the two half-buckle clamps are respectively arranged on the top of the two supports, and the deposition tube is clamped on the concentric component by the two half-buckle clamps.

3. The method for preparing an optical fiber core layer according to claim 2, characterized in that: The base is provided with a plurality of graduated slide grooves, the plurality of slide grooves respectively extending along the length direction and the width direction of the base, the slide grooves extending along the length direction and the width direction of the base are arranged crosswise with each other, the two supports are both slidably installed in the slide grooves, and the heights of the two supports in the vertical direction are adjustable; Among them, the step of arranging the head pipe, the deposition tube and the tail pipe along the same axis through the concentric components in step 2 includes: adjusting the positions of the two supports in the slide groove to adjust the position of the deposition tube relative to the head pipe and the tail pipe in the horizontal direction; and / or adjusting the heights of the two supports to adjust the position of the deposition tube relative to the head pipe and the tail pipe in the vertical direction, so that the head pipe, the deposition tube and the tail pipe are arranged along the same axis.

4. The method for preparing an optical fiber core layer according to claim 2 or 3, characterized in that: The two half-buckle rings are rotatably connected to the two supports respectively, the fixture is rotatably connected to the deposition lathe, and the half-buckle ring is used to drive the deposition tube to rotate and keep rotating in the same direction and speed as the fixture.

5. The method for preparing an optical fiber core layer according to claim 4, characterized in that: The diameters of the two half-buckle rings are adjustable, and the contact surfaces between the inner sides of the two half-buckle rings and the deposition tube are both soft contact surfaces.

6. The method for preparing an optical fiber core layer according to claim 5, characterized in that: Each of the half-buckle type clasps is composed of two identical half rings, one end of the two half rings is movably connected, and the other end of the two half rings can be locked or opened by a buckle.

7. The method for preparing an optical fiber core layer according to claim 1, characterized in that: In step 1, the two clamps respectively clamp and fix the opposite ends of the head pipe and the tail pipe at two ends of the deposition lathe, and the head pipe and the tail pipe are arranged along the same axis.

8. The method for preparing an optical fiber core layer according to claim 1, characterized in that: In step 3, after heating at least one of the opposite ends of the head tube and the deposition tube and before welding the head tube and the deposition tube, the following steps are further included: expanding the heated ends of the head tube and the deposition tube to be expanded; and / or, In step 4, after heating at least one of the opposite ends of the tail pipe and the deposition tube and before welding the tail pipe and the deposition tube, the step of expanding the heated ends of the tail pipe and the deposition tube to be expanded is also included.

9. The method for preparing an optical fiber core layer according to claim 8, characterized in that: In step 3, when the flaring operation is performed, at least one of the head tube and the deposition tube that needs to be flared rotates at a constant speed on the deposition lathe; when the welding operation is performed, both the head tube and the deposition tube rotate at a constant speed on the deposition lathe; In step 4, when the flaring operation is performed, at least one of the tail pipe and the deposition tube that needs to be flared rotates at a constant speed on the deposition lathe; when the welding operation is performed, both the tail pipe and the deposition tube rotate at a constant speed on the deposition lathe.

10. The method for preparing an optical fiber core layer according to claim 1 or 8, characterized in that: In step 3, the step of welding the head pipe and the deposition tube comprises: heating at least one of the opposite ends of the head pipe and the deposition tube to a molten state, and then contact welding the opposite ends of the head pipe and the deposition tube; In step 4, the step of welding the tail pipe and the deposition tube includes: heating at least one of the opposite ends of the tail pipe and the deposition tube to a molten state, and then contact welding the opposite ends of the tail pipe and the deposition tube.

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