Ultralow-loss optical fiber drawing preparation device

Abstract

The invention provides an ultralow-loss optical fiber drawing preparation device which is characterized in that a drawing furnace is used for melting a preform and drawing the preform into an optical fiber, an air guide ring is arranged in the drawing furnace and used for guiding airflow entering the drawing furnace, a heat conduction central pipe is arranged on the outer side of the air guide ring, and a heat conduction heater is arranged on the outer side of the heat conduction central pipe; the heat conduction central pipe is used for transferring heat of the heat conduction heater to the gas guide ring, and the heat conduction heater, the heat conduction central pipe and the gas guide ring are matched with one another to reduce vortex entering the wire drawing furnace and temperature fluctuation in the wire drawing furnace, so that the problems of unstable airflow, temperature fluctuation and the like existing in a traditional device are solved; according to the utility model, accurate guiding and heating of airflow entering the fiber drawing furnace are realized, so that eddy current generated by cold and hot intersection is reduced, the temperature uniformity in the fiber drawing furnace is improved, the influence of temperature fluctuation on the quality of optical fibers is reduced, the problems of core diameter fluctuation, Mie scattering loss and the like are effectively reduced, and the strength and low-loss attenuation performance of the optical fibers are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber drawing, and in particular to an ultra-low loss optical fiber drawing preparation device. Background Art

[0002] Ultra-low-loss optical fiber, as a key physical medium for long-distance transmission of optical signals, has extremely stringent requirements on optical and mechanical properties. Its manufacturing process is not only sophisticated and complex, but also requires more advanced equipment and processes than conventional optical fibers, and even puts forward higher requirements in some aspects. However, when faced with the manufacturing needs of ultra-low-loss optical fibers, traditional optical fiber drawing preparation has exposed a series of obvious deficiencies, which seriously restrict the further development of ultra-low-loss optical fibers in terms of attenuation reduction and strength improvement.

[0003] Specifically, the existing optical fiber drawing preparation methods are unable to meet the dual requirements of optical fiber strength and low loss attenuation performance of high-end products of 200kPs i. Among them, the most prominent problem is that the airflow management and temperature control in the drawing furnace have always been a difficult problem restricting the improvement of optical fiber quality.

[0004] First of all, the airflow conditions in the drawing furnace have an important impact on the preparation quality of the optical fiber. If the airflow is unstable or there are eddies, it will not only cause defects on the optical fiber surface, but also affect the uniformity and transmission performance of the optical fiber. When these room temperature gases flow downward, they will meet with part of the hot air flow flowing upward, thus forming an obvious cold and hot intersection area in the drawing furnace. In this area, the cold and hot air flows intertwine and collide with each other, forming a complex eddy structure. These eddies not only aggravate the unevenness of the temperature field in the drawing furnace, causing fluctuations in the diameter of the bare fiber, but also have a serious erosion effect on the graphite parts, causing powder to fall off on the surface. Once these fallen graphite powders adhere to the surface of the optical fiber, they will have an adverse effect on its strength. More seriously, the uneven temperature field caused by the eddy current will further cause core diameter fluctuations and Mie scattering loss problems, thereby seriously reducing the transmission performance of ultra-low loss optical fiber.

[0005] Secondly, the temperature fluctuation in the drawing furnace is also a key factor affecting the quality of optical fiber. Temperature fluctuations will cause changes in the melting rate and drawing rate of the optical fiber, which in turn affects the uniformity and consistency of the optical fiber. During the drawing process, a stable temperature environment needs to be maintained to ensure that the preform can be melted evenly and smoothly drawn into optical fiber. However, due to the complexity of the internal structure of the drawing furnace and the interference of the external environment, temperature fluctuations are often difficult to completely avoid, which will have an adverse effect on the preparation efficiency and yield rate of the optical fiber.

[0006] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application, nor does it necessarily provide technical guidance. In the absence of clear evidence that the above content has been disclosed before the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0007] In order to solve technical problems such as unstable airflow and temperature fluctuations existing in traditional devices, the present invention proposes an ultra-low loss optical fiber drawing preparation device, which solves technical problems such as unstable airflow and temperature fluctuations existing in traditional devices, and not only realizes the precise guidance and heating of the airflow entering the drawing furnace, thereby reducing the eddy currents generated by the intersection of cold and hot, but also improves the temperature uniformity in the drawing furnace, reduces the impact of temperature fluctuations on optical fiber quality, effectively reduces core diameter fluctuations and Mie scattering loss, and ensures optical fiber strength and low loss attenuation performance.

[0008] In order to achieve the above object, the technical solution of the present invention is as follows:

[0009] The present invention provides an ultra-low loss optical fiber drawing preparation device, comprising: a drawing furnace, the drawing furnace is used to melt a preform rod and draw it into an optical fiber, an air guide ring is arranged in the drawing furnace, the air guide ring is used to guide the airflow entering the drawing furnace, a heat-conducting central tube is arranged on the outer side of the air guide ring, a heat-conducting heater is arranged on the outer side of the heat-conducting central tube, the heat-conducting central tube is used to transfer the heat of the heat-conducting heater to the air guide ring, the heat-conducting heater, the heat-conducting central tube and the air guide ring cooperate with each other to reduce eddy currents entering the drawing furnace and temperature fluctuations in the drawing furnace.

[0010] The present invention proposes an ultra-low loss optical fiber drawing preparation device, which solves technical problems such as unstable airflow and temperature fluctuations existing in traditional devices. It not only realizes the precise guidance and heating of the airflow entering the drawing furnace, thereby reducing the eddy currents generated by the intersection of cold and hot, but also improves the temperature uniformity in the drawing furnace, reduces the impact of temperature fluctuations on optical fiber quality, effectively reduces problems such as core diameter fluctuations and Mie scattering loss, and ensures the optical fiber strength and low-loss attenuation performance.

[0011] As a preferred technical solution, the inner cavity of the air guide ring is provided with an S-shaped air flow guiding groove.

[0012] As an optimal technical solution, a rod hanging platform is provided on one end of the wire drawing furnace, a preform rod is connected to the rod hanging platform, the preform rod passes through one end of the wire drawing furnace and is arranged in the inner cavity of the air guide ring, and the other end of the wire drawing furnace is connected to one end of the distributed annealing furnace.

[0013] As a preferred technical solution, the distributed annealing furnace includes: multiple independent heating sections, each independent heating section is electrically connected to an independent temperature control system, and the inner cavity of the distributed annealing furnace first gradually expands its inner diameter from the independent heating section close to the wire drawing furnace to the independent heating section in the middle position, and then gradually reduces its inner diameter from the independent heating section in the middle position to the independent heating section far away from the wire drawing furnace.

[0014] As a preferred technical solution, the other end of the distributed annealing furnace is arranged corresponding to one end of a bare fiber diameter gauge, and the bare fiber diameter gauge is used to monitor in real time the diameter of the bare optical fiber prepared by the distributed annealing furnace, and the bare optical fiber diameter gauge is electrically connected to the PID controller, and the PID controller is electrically connected to the rod hanging platform and the drawing furnace, controls the working state of the rod hanging platform to adjust the feeding amount of the preform rod, and controls the working state of the drawing furnace to adjust the drawing speed of the drawing furnace to achieve automatic tuning of the diameter of the bare optical fiber.

[0015] As a preferred technical solution, the other end of the bare optical fiber diameter gauge is arranged corresponding to one end of the optical fiber coating mold base, and the optical fiber coating mold base is used to coat the bare optical fiber to form a coating. The optical fiber coating mold base includes: an inner coating mold core and an outer coating mold core, and the spacing between the inner coating mold core and the outer coating mold core is reduced to 4 to 6 mm;

[0016] By calculating the periodic change of the actual drawing coating tension of the optical fiber coating die seat and comparing it with the set tension value, the change trend of the drawing coating tension is obtained to self-coordinate the power of the drawing furnace.

[0017] As a preferred technical solution, the other end of the optical fiber coating mold base is arranged corresponding to one end of the optical fiber curing furnace, and the optical fiber curing furnace is used to cure the coating of the optical fiber. The other end of the optical fiber curing furnace is arranged corresponding to the optical fiber upper positioning wheel, and the optical fiber upper positioning wheel is used to transmit the optical fiber after the cured coating to the inlet of the optical fiber travel cooling component. The optical fiber travel cooling component outlet is provided with an optical fiber lower positioning wheel, and the optical fiber lower positioning wheel transmits the cooled optical fiber coating to the optical fiber coating thermometer.

[0018] As a preferred technical solution, the optical fiber travel cooling component includes: a plurality of elastic guide wheels, the plurality of elastic guide wheels are alternately arranged in multiple layers to form a heat dissipation channel between every two adjacent layers, each of the elastic guide wheels is connected to a guide wheel driving member, the optical fiber coating thermometer is used to monitor in real time the surface temperature of the optical fiber coating after cooling, the optical fiber coating thermometer is electrically connected to a PID controller, the PID controller is electrically connected to a guide wheel driving member, and the guide wheel driving member is controlled to drive the elastic guide wheel to move to adjust the spacing of the heat dissipation channel.

[0019] As a preferred technical solution, the optical fiber coating temperature meter is arranged corresponding to one end of the optical fiber coating diameter gauge, and the optical fiber coating diameter gauge is used to monitor the diameter of the optical fiber coating in real time. The optical fiber coating diameter gauge is electrically connected to the PID controller, and the PID controller is electrically connected to the optical fiber coating mold seat to control the working state of the optical fiber coating mold seat to adjust the temperature and pressure when applying the coating to achieve automatic tuning of the optical fiber coating diameter.

[0020] As a preferred technical solution, the other end of the optical fiber coating diameter gauge is arranged corresponding to the optical fiber steering wheel, and the optical fiber steering wheel is used to transfer the coated optical fiber to the optical fiber coating tension wheel, and the optical fiber coating tension wheel continues to transfer the coated optical fiber to the optical fiber main traction assembly, and the optical fiber main traction assembly includes: a wrapped satellite wheel, and the wrapped satellite wheel is used to realize traction and high-speed drawing of the optical fiber, and the optical fiber main traction assembly finally transfers the coated optical fiber to the optical fiber take-up assembly for take-up.

[0021] The present invention provides an ultra-low loss optical fiber drawing and preparation device, which has the following beneficial effects:

[0022] 1) It solves the technical problems of unstable airflow and temperature fluctuation in traditional devices. It not only realizes the precise guidance and heating of the airflow entering the drawing furnace, thereby reducing the eddy currents generated by the intersection of cold and hot, but also improves the temperature uniformity in the drawing furnace, reduces the impact of temperature fluctuations on the quality of optical fiber, effectively reduces the core diameter fluctuation and Mie scattering loss, and ensures the strength and low loss attenuation performance of optical fiber;

[0023] 2) The air guide ring is located inside the drawing furnace, and its main function is to guide the airflow entering the drawing furnace; the inner cavity of the air guide ring is preferably provided with an S-shaped airflow guide groove, which can ensure that the flow path of the airflow in the drawing furnace is more stable and reduce the formation of vortices; the heat-conducting central tube transfers the heat of the heat-conducting heater to the air guide ring. When the room temperature gas is heated by the air guide ring and the heat-conducting central tube, its temperature tends to be consistent with the temperature in the drawing furnace, and at the same time ensures that the gas is more evenly distributed in the drawing furnace; in this way, the intersection of cold and hot is greatly reduced, thereby reducing the formation of vortices. The reduction of vortices helps to stabilize the stretching of the optical fiber during the drawing process and reduces the fluctuation of the optical fiber quality caused by vortices;

[0024] The cooperation between the thermal conductive heater, the thermal conductive center tube and the gas guide ring not only heats the gas entering the drawing furnace, but also improves the temperature uniformity in the drawing furnace through heat conduction. By optimizing the airflow and temperature uniformity in the drawing furnace, the core diameter fluctuation and Mie scattering loss problems caused by temperature fluctuations are reduced, thereby improving the transmission efficiency and performance of the optical fiber.

[0025] 3) The change in the inner cavity structure of the distributed annealing furnace used in this application is helpful to form a more reasonable temperature gradient, so that the optical fiber can gradually adapt to different temperature environments during the heating process. The inner cavity of the distributed annealing furnace first gradually expands its inner diameter from the independent heating section close to the drawing furnace to the independent heating section in the middle position. The heating section close to the drawing furnace may be set at a higher temperature to ensure that the optical fiber is fully heated and softened in the initial stage; the inner cavity of the distributed annealing furnace then gradually reduces its inner diameter from the independent heating section in the middle position to the independent heating section far away from the drawing furnace. As the optical fiber anneals backward, the temperature gradually decreases, which helps the gradual cooling and solidification of the optical fiber and reduces the internal stress caused by temperature mutations;

[0026] The independent temperature control system equipped in each independent heating section can accurately control the temperature of the area, thereby ensuring the temperature uniformity during the entire annealing process. This design helps to reduce temperature fluctuations and improve the consistency and quality of optical fiber annealing. Precise temperature control and stable annealing process help to reduce the generation of thermal stress, optimize the mechanical properties of the optical fiber, and improve the surface quality and optical performance.

[0027] 4) The present application utilizes a bare fiber diameter gauge to perform real-time monitoring of the bare fiber drawn from the distributed annealing furnace, and the PID controller receives the bare fiber diameter data from the bare fiber diameter gauge, compares the real-time monitored fiber diameter data with the preset diameter setting value, calculates the deviation, and according to the deviation, the PID controller adjusts the parameters such as the amount of preform rods entering the drawing furnace through the rod hanging platform and the drawing speed of the drawing furnace. The adjusted control parameters are responded by the rod hanging platform and the drawing furnace, and the rod hanging platform and the drawing furnace adjust their working states according to the received signals, thereby realizing precise control of the fiber diameter. The above control system realizes automated control of the optical fiber preparation process, reduces manual intervention and the generation of errors, which helps to improve production efficiency and reduce production costs.

[0028] 5) The present invention redesigns and adjusts the feeding method of the mold, thereby greatly reducing the distance between the inner coating mold core and the outer coating mold core to about 5 mm, reducing the coating resistance, reducing the generation of coating bubbles and defects, and improving the strength of the optical fiber;

[0029] According to the calculated tension change trend, the control system formulates an adjustment strategy for the drawing furnace power; when the optical fiber coating die seat sensor detects that the actual drawing coating tension is higher than the set tension, the PID controller receives the signal that the actual drawing coating tension is higher than the set tension and controls to reduce the drawing furnace power to reduce the tensile force of the optical fiber during the coating process; when the optical fiber coating die seat sensor detects that the actual drawing coating tension is lower than the set tension, the PID controller receives the signal that the actual drawing coating tension is lower than the set tension and controls to increase the drawing furnace power to increase the tensile force of the optical fiber during the coating process to reach the preset tension value; the PID controller adjusts the drawing furnace power by regulating the current or voltage of the heating element (such as the induction coil) of the drawing furnace; the adjusted power will directly affect the heating temperature and softening degree of the optical fiber, thereby affecting the tensile force and tension of the optical fiber during the coating process. This automated control helps to reduce manual intervention and improve production efficiency and product quality.

[0030] 6) The main function of the optical fiber curing furnace is to heat and cure the coating on the optical fiber. The upper optical fiber positioning wheel and the lower optical fiber positioning wheel are jointly responsible for first transferring the optical fiber from the optical fiber curing furnace to the optical fiber travel cooling component, and then transferring the cooled optical fiber to the optical fiber coating temperature meter; these positioning wheels ensure that the optical fiber maintains a stable path during the transmission process, preventing the optical fiber from being damaged or deviating from the predetermined path during the transmission process;

[0031] At the same time, the fully cooled coated optical fiber has high robustness when entering the optical fiber main pulling assembly and the optical fiber take-up assembly, is not easy to be flattened, and maintains good geometric roundness, thereby improving the roundness of the coated optical fiber;

[0032] The present application adopts an optical fiber coating thermometer to monitor the surface temperature of the optical fiber coating after cooling in real time, and feeds back the temperature data to the PID controller. The PID controller controls the guide wheel driver to drive the elastic guide wheel to move according to the fed-back temperature data to adjust the spacing of the heat dissipation channel. The PID controller controls the guide wheel driver to drive the multiple layers of elastic guide wheels arranged alternately to move to form heat dissipation channels with larger spacing or smaller spacing, allowing more or less air to flow in the heat dissipation channel, thereby effectively taking away the heat of the optical fiber, realizing rapid cooling of the optical fiber, and stably controlling the temperature of the optical fiber coating surface at the outlet of the optical fiber travel cooling component within a reasonable range, thereby realizing the control of the thermal stress of the optical fiber coating after curing, improving the uniformity of the optical fiber coating stress, and facilitating further reduction of optical fiber attenuation.

[0033] 7) The optical fiber coating diameter gauge continuously emits a light beam and receives reflected light. By measuring the intensity and waveform changes of the reflected light signal, the diameter data of the optical fiber coating is calculated. This data is fed back to the PID controller in real time. After receiving the diameter data, the PID controller compares and analyzes it with the preset diameter standard value. If there is a deviation between the actual diameter of the optical fiber coating and the standard value of the optical fiber coating, the PID controller will start the adjustment program. Through PID calculation, the PID controller calculates the temperature and pressure value parameters that need to be adjusted. Then, it sends these parameter adjustment instructions to the optical fiber coating mold holder. The optical fiber coating mold holder adjusts the temperature and pressure when applying the coating according to the control instructions of the PID controller. By precisely controlling these parameters, the optical fiber coating mold holder can gradually reduce the deviation between the actual diameter of the optical fiber coating and the standard value of the optical fiber coating, and realize automatic tuning of the coating diameter. The automatic adjustment ensures the uniformity of the optical fiber coating. The diameter of the optical fiber coating will be stably maintained within the standard range without manual operation, thereby improving the quality and production efficiency of optical fiber products.

[0034] 8) The optical fiber main traction assembly of the present application eliminates the belt and adopts a wrapped satellite wheel to achieve high-speed optical fiber drawing by traction. The wrapped satellite wheel will not slip during operation, and the reliability of the length meter is maintained. This method reduces the non-roundness of the optical fiber coating and improves the additional attenuation of the optical fiber coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of an ultra-low loss optical fiber drawing and preparation device provided by the present invention;

[0036] Figure 2 A partial structural schematic diagram of an ultra-low loss optical fiber drawing and preparation device provided by the present invention;

[0037] Figure 3 A schematic structural diagram of an air guide ring in an ultra-low loss optical fiber drawing preparation device provided by the present invention.

[0038] Among them: 1-rod hanging platform; 2-preform rod; 3-drawing furnace air inlet position; 4-thermal heater; 5-thermal center tube; 6-air guide ring; 7-drawing furnace; 8-distributed annealing furnace; 81-independent heating section; 82-independent heating section in the middle position; 9-bare fiber diameter gauge; 10-optical fiber coating mold base; 11-optical fiber curing furnace; 12-optical fiber upper positioning wheel; 13-optical fiber travel cooling component; 131-elastic guide wheel; 132-heat dissipation channel; 14-optical fiber lower positioning wheel; 15-optical fiber coating temperature meter; 16-optical fiber coating diameter gauge; 17-optical fiber steering wheel; 18-optical fiber coating tension wheel; 19-wrapped satellite wheel; 20-optical fiber main traction upper positioning wheel; 21-optical fiber take-up positioning wheel; 22-optical fiber take-up drum. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] like Figure 1-3 As shown, the present invention provides an ultra-low loss optical fiber drawing preparation device, comprising: a drawing furnace 7, the drawing furnace 7 is used to melt the preform 2 and draw it into an optical fiber, an air guide ring 6 is arranged inside the drawing furnace 7, the air guide ring 6 is used to guide the airflow entering the drawing furnace, a heat-conducting central tube 5 is arranged on the outside of the air guide ring 6, a heat-conducting heater 4 is arranged on the outside of the heat-conducting central tube 5, the heat-conducting central tube 5 is used to transfer the heat of the heat-conducting heater 4 to the air guide ring 6, the heat-conducting heater 4, the heat-conducting central tube 5 and the air guide ring 6 cooperate with each other to reduce the eddy current entering the drawing furnace 7 and the temperature fluctuation in the drawing furnace 7.

[0041] The present invention proposes an ultra-low loss optical fiber drawing preparation device, which solves technical problems such as unstable airflow and temperature fluctuations existing in traditional devices. It not only realizes the precise guidance and heating of the airflow entering the drawing furnace, thereby reducing the eddy currents generated by the intersection of cold and hot, but also improves the temperature uniformity in the drawing furnace, reduces the impact of temperature fluctuations on optical fiber quality, effectively reduces problems such as core diameter fluctuations and Mie scattering loss, and ensures the optical fiber strength and low-loss attenuation performance.

[0042] Preferably, if Figure 3 As shown, the inner cavity of the air guide ring 6 is provided with an S-shaped airflow guiding groove. The design of the S-shaped airflow guiding groove enables the airflow entering the wire drawing furnace 7 to flow along a relatively smooth and continuous path. This design avoids the airflow from forming a sharp turn or collision in the furnace, thereby reducing the vortex generated when the cold and hot air flows meet, and at the same time improving the temperature uniformity in the wire drawing furnace; at the same time, through the guidance of the S-shaped airflow guiding groove, the pressure distribution of the airflow in the furnace becomes more uniform, maintaining a stable wire drawing environment and improving product quality.

[0043] Preferably, if Figure 1-2 As shown, the material of the thermal conductive center tube 5 is preferably graphite, and the material of the thermal conductive heater 4 is preferably graphite; graphite has good thermal conductivity, high thermal conductivity, and can quickly transfer heat, which makes graphite the preferred material for the thermal conductive center tube 5, because it can ensure that heat is quickly and evenly distributed in the thermal conductive center tube 5, thereby improving the thermal efficiency of the entire system; graphite has good electrical conductivity and electrical resistance. When electricity is applied, graphite will generate heat and quickly transfer it to the heated object, which makes graphite an ideal material for the thermal conductive heater 4, because it can quickly transfer heat to the target object and improve the heating efficiency.

[0044] Preferably, if Figure 1-2As shown, a rod hanging platform 1 is provided on one end of the wire drawing furnace 7, and a preform rod 2 is connected to the rod hanging platform 1. The preform rod 2 passes through one end of the wire drawing furnace 7 and is arranged in the inner cavity of the air guide ring 6. The other end of the wire drawing furnace 7 is connected to one end of the distributed annealing furnace 8. It has a simple structure and is easy to operate.

[0045] Preferably, if Figure 1 As shown, the distributed annealing furnace 8 comprises: a plurality of independent heating sections 81, each independent heating section 81 is electrically connected to an independent temperature control system, and the inner diameter of the inner cavity of the distributed annealing furnace 8 is gradually expanded from the independent heating section 81 close to the wire drawing furnace 7 to the independent heating section 82 in the middle, and then gradually reduced from the independent heating section 82 in the middle to the independent heating section 81 far away from the wire drawing furnace 7;

[0046] The traditional annealing process has the following shortcomings: insufficient temperature control accuracy and uniformity during the annealing process, which has an adverse effect on the performance of the optical fiber;

[0047] The inner cavity structure change of the distributed annealing furnace 8 adopted in the present application is helpful to form a more reasonable temperature gradient, so that the optical fiber can gradually adapt to different temperature environments during the heating process. The inner cavity of the distributed annealing furnace 8 first gradually expands its inner diameter from the independent heating section 81 close to the drawing furnace 7 to the independent heating section 82 in the middle position. The heating section close to the drawing furnace may be set at a higher temperature to ensure that the optical fiber is fully heated and softened in the initial stage; the inner cavity of the distributed annealing furnace 8 gradually reduces its inner diameter from the independent heating section 82 in the middle position to the independent heating section 81 far away from the drawing furnace 7. As the optical fiber is annealed backward, the temperature gradually decreases, which helps the gradual cooling and solidification of the optical fiber and reduces the internal stress caused by temperature mutation.

[0048] The independent temperature control system equipped in each independent heating section 81 can accurately control the temperature of the area, thereby ensuring the temperature uniformity during the entire annealing process. This design helps to reduce temperature fluctuations and improve the consistency and quality of optical fiber annealing. Precise temperature control and a stable annealing process help to reduce the generation of thermal stress, optimize the mechanical properties of the optical fiber, and improve the surface quality and optical performance.

[0049] Preferably, if Figure 1 As shown, the other end of the distributed annealing furnace 8 is arranged corresponding to one end of a bare fiber diameter gauge 9, and the bare fiber diameter gauge 9 is used to monitor the diameter of the bare fiber prepared by the distributed annealing furnace 8 in real time. The bare fiber diameter gauge 9 is electrically connected to the PID controller, and the PID controller is electrically connected to the rod hanging platform 1 and the drawing furnace 7, and controls the working state of the rod hanging platform 1 to adjust the rod feeding amount of the preform rod 2 and controls the working state of the drawing furnace 7 to adjust the drawing speed of the drawing furnace 7 to achieve automatic tuning of the diameter of the bare fiber;

[0050] The present application utilizes a bare fiber diameter gauge 9 to perform real-time monitoring of the bare fiber drawn from the distributed annealing furnace 8, and the PID controller receives the bare fiber diameter data from the bare fiber diameter gauge 9, compares the real-time monitored fiber diameter data with a preset diameter setting value, calculates the deviation, and according to the deviation, the PID controller adjusts the rod feeding amount of the preform rod 2 entering the drawing furnace 7 of the rod hanging platform 1 and the drawing speed of the drawing furnace 7. The adjusted control parameters are responded by the rod hanging platform 1 and the drawing furnace 7, and the rod hanging platform 1 and the drawing furnace 7 adjust their working states according to the received signals, thereby realizing precise control of the fiber diameter. The above control system realizes automated control of the optical fiber preparation process, reduces manual intervention and the generation of errors, which helps to improve production efficiency and reduce production costs.

[0051] Preferably, if Figure 1 As shown, the other end of the bare fiber diameter gauge 9 is arranged corresponding to one end of the optical fiber coating mold base 10, and the optical fiber coating mold base 10 is used to coat the bare optical fiber to form a coating. The optical fiber coating mold base 10 includes: an inner coating mold core and an outer coating mold core, and the distance between the inner coating mold core and the outer coating mold core is reduced to 4 to 6 mm;

[0052] By calculating the periodic change of the actual drawing coating tension of the optical fiber coating die seat and comparing it with the set tension value, the change trend of the drawing coating tension is obtained to self-coordinate the power of the drawing furnace.

[0053] In the design of the traditional coating mold, the optical fiber needs to be coated with two layers of coating, inner and outer, at one time. Generally, it first passes through the inner coating mold core, and then enters the outer coating mold core after passing through a channel about 20 mm long, and the travel is relatively long. The present invention redesigns and adjusts the feeding method of the mold, thereby greatly reducing the distance between the inner coating mold core and the outer coating mold core to about 5 mm, reducing the coating resistance, reducing the generation of coating bubbles and defects, and improving the strength of the optical fiber.

[0054] By calculating the periodic change of the actual drawing coating tension of the optical fiber coating die holder 10 and comparing it with the set tension value, the change trend of the drawing coating tension is obtained to perform self-coordination of the power of the drawing furnace 7;

[0055] According to the calculated tension variation trend, the control system formulates an adjustment strategy for the power of the drawing furnace 7; when the optical fiber coating die seat sensor detects that the actual drawing coating tension is higher than the set tension, the PID controller receives the signal that the actual drawing coating tension is higher than the set tension and controls to reduce the power of the drawing furnace to reduce the tensile force of the optical fiber during the coating process; when the optical fiber coating die seat sensor detects that the actual drawing coating tension is lower than the set tension, the PID controller receives the signal that the actual drawing coating tension is lower than the set tension and controls to increase the power of the drawing furnace to increase the tensile force of the optical fiber during the coating process to reach the preset tension value; the PID controller adjusts the power of the drawing furnace 7 by regulating the current or voltage of the heating element (such as an induction coil) of the drawing furnace 7; the adjusted power will directly affect the heating temperature and softening degree of the optical fiber, thereby affecting the tensile force and tension of the optical fiber during the coating process. This automated control helps to reduce manual intervention and improve production efficiency and product quality.

[0056] Preferably, if Figure 1 As shown, the other end of the optical fiber coating mold base 10 is arranged corresponding to one end of the optical fiber curing furnace 11, and the optical fiber curing furnace 11 is used to cure the coating of the optical fiber. The other end of the optical fiber curing furnace 11 is arranged corresponding to the optical fiber upper positioning wheel 12, and the optical fiber upper positioning wheel 12 is used to transmit the optical fiber after the coating is cured to the entrance of the optical fiber travel cooling component 13. The optical fiber travel cooling component 13 is provided with an optical fiber lower positioning wheel 14 at the exit, and the optical fiber lower positioning wheel 14 transmits the cooled optical fiber coating to the optical fiber coating temperature meter 15;

[0057] The main function of the optical fiber curing furnace is to heat and cure the coating on the optical fiber. The optical fiber upper positioning wheel 12 and the optical fiber lower positioning wheel 14 are jointly responsible for first transmitting the optical fiber from the optical fiber curing furnace 11 to the optical fiber travel cooling component 13, and then transmitting the cooled optical fiber to the optical fiber coating temperature meter 15; these positioning wheels ensure that the optical fiber maintains a stable path during the transmission process, preventing the optical fiber from being damaged or deviating from the predetermined path during the transmission process;

[0058] At the same time, the fully cooled coated optical fiber has high robustness when entering the optical fiber main traction component and the optical fiber take-up component, is not easy to be flattened, and maintains good geometric roundness, thereby improving the roundness of the coated optical fiber.

[0059] Preferably, if Figure 1As shown, the optical fiber travel cooling assembly 13 includes: a plurality of elastic guide wheels 131, the plurality of elastic guide wheels 131 are alternately arranged in multiple layers to form a heat dissipation channel 132 between every two adjacent layers, each of the elastic guide wheels 131 is connected to a guide wheel driving member (not shown), the optical fiber coating temperature meter 15 is electrically connected to a PID controller, the PID controller is electrically connected to a guide wheel driving member (not shown), and the guide wheel driving member (not shown) is controlled to drive the elastic guide wheel 131 to move so as to adjust the spacing of the heat dissipation channel 132 between every two adjacent layers;

[0060] In the prior art, after the optical fiber comes out of the optical fiber curing furnace, its surface temperature is usually high, and usually simple natural cooling or forced cooling with a helium tube passing water is adopted. However, the cost is high after adding helium, and the simple self-heating cooling effect is poor. It is impossible to ensure that the optical fiber deformation and breakage caused by the high temperature of the coating or the coating stress will increase the risk of attenuation and strength deterioration.

[0061] The present application adopts an optical fiber coating thermometer 15 to monitor the surface temperature of the optical fiber coating after cooling in real time, and feeds back the temperature data to the PID controller. The PID controller controls the guide wheel driving member (not shown) to drive the elastic guide wheel 131 to move according to the fed-back temperature data to adjust the spacing of the heat dissipation channel 132. The PID controller controls the guide wheel driving member (not shown) to drive the multiple layers of elastic guide wheels 131 arranged alternately to move to form heat dissipation channels 132 with larger spacing or smaller spacing, allowing more or less air to flow in the heat dissipation channel 132, thereby effectively taking away the heat of the optical fiber, realizing rapid cooling of the optical fiber, and stably controlling the temperature of the optical fiber coating surface at the outlet of the optical fiber travel cooling component 13 within a reasonable range, thereby realizing the control of the thermal stress of the optical fiber coating after curing, improving the uniformity of the optical fiber coating stress, and facilitating the further reduction of optical fiber attenuation, while reducing production costs.

[0062] Preferably, if Figure 1 As shown, the optical fiber coating temperature meter 15 is arranged corresponding to one end of the optical fiber coating diameter gauge 16, and the optical fiber coating diameter gauge 16 is used to monitor the diameter of the optical fiber coating in real time. The optical fiber coating diameter gauge 16 is electrically connected to the PID controller, and the PID controller is electrically connected to the optical fiber coating mold base 10 to control the working state of the optical fiber coating mold base 10 to adjust the temperature and pressure when applying the coating to achieve automatic tuning of the optical fiber coating diameter;

[0063] The optical fiber coating diameter gauge 16 continuously emits a light beam and receives reflected light, and calculates the diameter data of the optical fiber coating by measuring the intensity and waveform change of the reflected light signal. This data is fed back to the PID controller in real time. After receiving the diameter data, the PID controller compares and analyzes it with the preset diameter standard value. If there is a deviation between the actual diameter of the optical fiber coating and the standard value of the optical fiber coating, the PID controller will start the adjustment program. Through the PID operation, the PID controller calculates the temperature and pressure value parameters that need to be adjusted, and then it sends these parameter adjustment instructions to the optical fiber coating mold base 10. The optical fiber coating mold base 10 adjusts the temperature and pressure when applying the coating according to the control instructions of the PID controller; by accurately controlling these parameters, the optical fiber coating mold base 10 can gradually reduce the deviation between the actual diameter of the optical fiber coating and the standard value of the optical fiber coating, and realize automatic tuning of the coating diameter. The automatic adjustment ensures the uniformity of the optical fiber coating, and the diameter of the optical fiber coating will be stably maintained within the standard range without manual operation, thereby improving the quality and production efficiency of optical fiber products.

[0064] Preferably, if Figure 1 As shown, the optical fiber main traction assembly includes: a wrapped satellite wheel 19 and an optical fiber main traction upper positioning wheel 20, the optical fiber take-up assembly includes: an optical fiber take-up positioning wheel 21 and an optical fiber take-up drum 22, the other end of the optical fiber coating diameter gauge 16 is arranged corresponding to the optical fiber steering wheel 17, the optical fiber steering wheel 17 is used to transmit the coated optical fiber to the optical fiber coating tension wheel 18, the optical fiber coating tension wheel 18 continues to transmit the coated optical fiber to the wrapped satellite wheel 19, the wrapped satellite wheel 19 is used to realize high-speed optical fiber drawing driven by traction, the wrapped satellite wheel 19 continues to transmit the coated optical fiber to the optical fiber main traction upper positioning wheel 20, the optical fiber main traction upper positioning wheel 20 finally transmits the coated optical fiber through the optical fiber take-up positioning wheel 21 to the optical fiber take-up drum 22 for take-up;

[0065] Existing optical fiber main traction uses belts to clamp the optical fiber, which can easily flatten the optical fiber coating, resulting in increased out-of-roundness. At the same time, the pressure applied to the coating remains in the coating, which is detrimental to the subsequent optical fiber attenuation.

[0066] The optical fiber main traction assembly of the present application eliminates the belt and adopts a wrapped satellite wheel 19 to achieve high-speed optical fiber drawing by traction. The wrapped satellite wheel 19 will not slip during operation, and the reliability of the length meter is maintained. This method reduces the non-roundness of the optical fiber coating and improves the additional attenuation of the optical fiber coating.

[0067] like Figure 1-3As shown, the present invention provides an ultra-low loss optical fiber drawing preparation device, which optimizes each link in the optical fiber drawing preparation production process, including airflow heating design, five-stage annealing temperature control, coating core spacing optimization, automatic control system, beltless traction design and other key technical innovations, and the mutual cooperation and optimization of each link in the entire production process, which not only achieves the minimization of optical fiber attenuation, maximization of strength and uniformity of surface quality, but also ensures the high quality, low loss and high stability of the optical fiber, and achieves breakthroughs in production efficiency and consistency of optical fiber quality.

[0068] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all various changes or equivalent substitutions falling within the scope of the claims of the present application are included. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope protected by the present invention.

Claims

1. An ultra-low loss optical fiber drawing and preparation device, characterized in that: include: A wire drawing furnace, the wire drawing furnace is used to melt preform rods and draw them into optical fibers, an air guide ring is provided inside the wire drawing furnace, the air guide ring is used to guide the air flow entering the wire drawing furnace, a heat-conducting central tube is provided on the outside of the air guide ring, a heat-conducting heater is provided on the outside of the heat-conducting central tube, the heat-conducting central tube is used to transfer the heat of the heat-conducting heater to the air guide ring, the heat-conducting heater, the heat-conducting central tube and the air guide ring cooperate with each other to reduce eddy currents entering the wire drawing furnace and temperature fluctuations in the wire drawing furnace.

2. The ultra-low loss optical fiber drawing and preparation device according to claim 1, characterized in that: The inner cavity of the air guide ring is provided with an S-shaped air flow guiding groove.

3. The ultra-low loss optical fiber drawing and preparation device according to claim 1 or 2, characterized in that: A rod hanging platform is provided on one end of the wire drawing furnace, a preform rod is connected to the rod hanging platform, the preform rod passes through one end of the wire drawing furnace and is arranged in the inner cavity of the air guide ring, and the other end of the wire drawing furnace is connected to one end of the distributed annealing furnace.

4. The ultra-low loss optical fiber drawing and preparation device according to claim 3, characterized in that: The distributed annealing furnace comprises: a plurality of independent heating sections, each of which is electrically connected to an independent temperature control system. The inner diameter of the inner cavity of the distributed annealing furnace is gradually expanded from the independent heating section close to the wire drawing furnace to the independent heating section in the middle position, and then the inner diameter is gradually reduced from the independent heating section in the middle position to the independent heating section far away from the wire drawing furnace.

5. The ultra-low loss optical fiber drawing and preparation device according to claim 3, characterized in that: The other end of the distributed annealing furnace is arranged corresponding to one end of a bare optical fiber diameter gauge, and the bare optical fiber diameter gauge is used to monitor in real time the diameter of the bare optical fiber prepared by the distributed annealing furnace. The bare optical fiber diameter gauge is electrically connected to the PID controller, and the PID controller is electrically connected to the rod hanging platform and the drawing furnace, and controls the working state of the rod hanging platform to adjust the feeding amount of the preform rod and controls the working state of the drawing furnace to adjust the drawing speed of the drawing furnace to achieve automatic tuning of the diameter of the bare optical fiber.

6. The ultra-low loss optical fiber drawing and preparation device according to claim 5, characterized in that: The other end of the bare fiber diameter gauge is arranged corresponding to one end of the optical fiber coating mold base, and the optical fiber coating mold base is used to coat the bare optical fiber to form a coating. The optical fiber coating mold base includes: an inner coating mold core and an outer coating mold core, and the distance between the inner coating mold core and the outer coating mold core is reduced to 4-6 mm; By calculating the periodic change of the actual drawing coating tension of the optical fiber coating die seat and comparing it with the set tension value, the change trend of the drawing coating tension is obtained to self-coordinate the power of the drawing furnace.

7. The ultra-low loss optical fiber drawing and preparation device according to claim 6, characterized in that: The other end of the optical fiber coating mold base is arranged corresponding to one end of the optical fiber curing furnace, and the optical fiber curing furnace is used to cure the coating of the optical fiber. The other end of the optical fiber curing furnace is arranged corresponding to the optical fiber upper positioning wheel, and the optical fiber upper positioning wheel is used to transmit the optical fiber after the cured coating to the inlet of the optical fiber travel cooling component. The optical fiber travel cooling component outlet is provided with an optical fiber lower positioning wheel, and the optical fiber lower positioning wheel transmits the cooled optical fiber coating to the optical fiber coating thermometer.

8. The ultra-low loss optical fiber drawing and preparation device according to claim 7, characterized in that: The optical fiber travel cooling component includes: a plurality of elastic guide wheels, the plurality of elastic guide wheels are alternately arranged in multiple layers to form a heat dissipation channel between every two adjacent layers, each of the elastic guide wheels is connected to a guide wheel driving member, the optical fiber coating thermometer is used to monitor the surface temperature of the optical fiber coating after cooling in real time, the optical fiber coating thermometer is electrically connected to a PID controller, the PID controller is electrically connected to a guide wheel driving member, and the guide wheel driving member is controlled to drive the elastic guide wheel to move to adjust the spacing of the heat dissipation channel.

9. The ultra-low loss optical fiber drawing and preparation device according to claim 7, characterized in that: The optical fiber coating temperature meter is arranged corresponding to one end of the optical fiber coating diameter gauge, and the optical fiber coating diameter gauge is used to monitor the diameter of the optical fiber coating in real time. The optical fiber coating diameter gauge is electrically connected to the PID controller, and the PID controller is electrically connected to the optical fiber coating mold seat to control the working state of the optical fiber coating mold seat to adjust the temperature and pressure when applying the coating to achieve automatic tuning of the optical fiber coating diameter.

10. The ultra-low loss optical fiber drawing and preparation device according to claim 9, characterized in that: The other end of the optical fiber coating diameter gauge is arranged corresponding to the optical fiber steering wheel, and the optical fiber steering wheel is used to transfer the coated optical fiber to the optical fiber coating tension wheel, and the optical fiber coating tension wheel continues to transfer the coated optical fiber to the optical fiber main traction assembly, and the optical fiber main traction assembly includes: a wrapped satellite wheel, and the wrapped satellite wheel is used to realize traction and high-speed optical fiber drawing. The optical fiber main traction assembly finally transfers the coated optical fiber to the optical fiber take-up assembly for take-up.

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