A special optical fiber drawing tower

Abstract

The present invention discloses a special optical fiber drawing tower. The optical fiber drawing tower includes a preform rod suspension system, a special drawing furnace, an integrated control system, a wire diameter control system, an optical fiber coating system and a wire collection system; the optical fiber preform rod is fixed to the preform rod suspension system, and the movement of the optical fiber preform rod is controlled by the preform rod suspension system; the optical fiber preform rod is fed into the special drawing furnace, and the special drawing furnace is heated to soften the optical fiber preform rod to reach the drawing state; the optical fiber preform rod softened by the special drawing furnace is drawn by the wire diameter control system and the wire diameter is controlled to obtain an optical fiber of the required specification; finally, the optical fiber is coated and wound and stored by the optical fiber coating system and the wire collection system. The present invention can meet the precision drawing of multi-material composite optical fibers and special structure composite optical fibers, and effectively solves the problem that the existing optical fiber drawing tower is difficult to meet the different drawing requirements of multiple optical fibers.

Description

Technical Field

[0001] The invention belongs to the technical field of special optical fibers, and in particular relates to a special optical fiber drawing tower. Background Art

[0002] As a micron-sized optical waveguide, optical fiber is generally obtained by drawing glass and other materials at high temperature. Therefore, the drawing tower and drawing process determine the quality of the finished optical fiber, including fiber uniformity, non-circularity, core-shell concentricity, core-shell interface bonding, and fiber continuity.

[0003] During the drawing process, the temperature field distribution of the drawing tower directly determines the mechanical equilibrium state of the drawing cone area after the optical fiber preform is softened. For example, when the annular temperature field around the preform is uneven, it will lead to problems such as increased fiber optic non-circularity and uneven fiber diameter; when the longitudinal temperature field height of the preform does not match the preform diameter, it is easy to cause problems such as broken fiber and difficult to control fiber diameter during the fiber drawing process. For traditional commercial quartz optical fibers, their preforms are usually prepared by CVD (chemical vapor deposition) deposition. The preform material and size are relatively fixed. The drawing process is completed by a graphite drawing furnace in conjunction with a high-speed drawing tower. The drawing process and production standards are relatively mature and have certain specifications and standards. Conventional high-speed drawing towers can meet the needs (authorization announcement number: CN210314013U). However, for special optical fibers, due to their special material composition or waveguide structure, conventional drawing towers are often difficult to meet their drawing needs.

[0004] Special optical fiber refers to various types of optical fibers that have other special functions or are used in special environments in addition to conventional quartz optical fibers. According to the optical fiber matrix material, it can be divided into special soft glass optical fiber, semiconductor composite optical fiber, crystal composite optical fiber, ceramic composite optical fiber and plastic optical fiber. For special optical fibers, the preparation method is generally the rod-tube method; and for different optical fiber matrix materials, the size of the preform rods is often quite different, and the temperature field required for drawing is also quite different. For example, from plastic optical fiber to special soft glass optical fiber to quartz glass optical fiber, the drawing temperature can differ by more than 1900 ℃ (100 ~ 2000 ℃), and the temperature field distribution must also be adjusted greatly due to the size of the preform rod. Obviously, for special material preform rods of different sizes and thermal properties, the drawing process has great differences in the thermal system requirements of the drawing tower. Therefore, conventional drawing towers are difficult to meet the drawing needs of special optical fibers. In the face of different special optical fiber preform rods, it is easy to cause uneven optical fibers, damage to optical fiber structures, optical fiber crystallization and broken wires, etc., which seriously wastes special preform rods and causes great losses.

[0005] At present, the heating device of conventional optical fiber drawing towers is an integrated component. When facing special material preforms with different matrix materials, different sizes and different thermal properties, the heating device of the drawing tower cannot quickly adjust and optimize its temperature field; if the temperature field distribution does not match the characteristics of the preform, it is easy to cause the fiber to be out of round, uneven or broken. Therefore, it is necessary to design an optical fiber drawing tower that can quickly adjust the thermal characteristics of the drawing tower heating device and is suitable for a variety of special preforms; thereby improving the success rate and quality of special optical fiber drawing.

[0006] Furthermore, according to the structural characteristics of the optical fiber, the optical fiber can also be divided into step-index optical fiber and special structure composite optical fiber. Special structure composite optical fiber can be divided into multi-core optical fiber, multi-cladding optical fiber, photonic crystal optical fiber, hollow antiresonant optical fiber and spiral optical fiber according to its waveguide structure. For conventional special structure optical fibers such as multi-core optical fiber and photonic crystal optical fiber that do not have axial structural changes, long-distance and efficient preparation can be directly achieved by rod-tube method, bundle drawing method and other methods. However, for optical fibers with periodic axial torsion characteristics, such as spiral optical fibers, they cannot be directly prepared by simple hot drawing method. At present, the preparation method of spiral optical fiber is usually based on the drawn optical fiber, which is prepared by hot melt mechanical torsion method (authorization announcement number: CN210477873U); this method can only prepare spiral optical fiber in sections, which is inefficient, and the optical fiber needs to be heated twice, which is easy to cause damage such as optical fiber crystallization, and it is impossible to prepare spiral optical fiber efficiently and over long distances. Therefore, it is also necessary to design a special drawing tower that can prepare special spiral optical fibers efficiently and in large quantities.

[0007] In summary, in order to meet the current complex preparation needs of special material composite optical fibers and special structure composite optical fibers, there is an urgent need for a special drawing tower that can quickly adjust the temperature field distribution of the drawing tower and control the movement state of the preform rod in multiple dimensions, so as to achieve efficient and large-scale preparation of special optical fibers. Summary of the invention

[0008] In order to solve the deficiencies of the above-mentioned prior art, the present invention provides a special optical fiber drawing tower for drawing special material or structural preform rods. By modularizing the heating device of the special optical fiber drawing tower, rapid and controllable adjustment of the drawing temperature field distribution can be achieved; further, the preform rod suspension system is used to control the preform rod's multi-dimensional motion, so as to solve the current problem that special material composite and structural composite optical fibers are difficult to draw efficiently and over long distances.

[0009] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0010] A special optical fiber drawing tower, comprising: a preform rod suspension system, a special drawing furnace, an integrated control system, a wire diameter control system, an optical fiber coating system and a wire collection system;

[0011] The preform rod suspension system, special drawing furnace, wire diameter control system, optical fiber coating system and wire collection system are multiple subsystems at the same level; the integrated control system is a higher-level system, which monitors the working status and operating parameters of each subsystem in real time. After the working parameters of each subsystem are fed back to each other, the integrated control system actively or passively corrects the working status of each subsystem based on the operating parameters, and finally realizes the operation of the drawing tower; the preform rod suspension system is used to fix the optical fiber preform and control the optical fiber preform to achieve multi-dimensional movement; the special drawing furnace is used to soften the optical fiber preform to reach the drawing state; the wire diameter control system is used to draw the optical fiber preform softened by the special drawing furnace and control the wire diameter to obtain optical fiber of required specifications; the optical fiber coating system is used to coat the optical fiber, and the wire collection system is used to coat the optical fiber and wind the wire for storage.

[0012] Further, the preform suspension system comprises a vertical feeding motor, a precision lead screw, a suspension arm, an axial torsion motor, a preform connecting rod and an air path joint;

[0013] Among them, the vertical feeding motor and the precision screw are tightly connected through a coupling, and the vertical feeding motor can drive the precision screw to rotate at a uniform speed; one end of the suspension arm is meshed with the precision screw through a gear, and the other end is connected to the axial torsion motor. The rotation of the precision screw can control the suspension arm to move up and down at a uniform speed. The suspension arm is a double-layer structure and can slide in both directions forward, backward, left and right; the axial torsion motor and the preform rod connecting rod are tightly connected through a flange, and the axial torsion motor can drive the preform rod connecting rod to twist concentrically, thereby controlling the torsion of the optical fiber preform; the preform rod connecting rod is sealed and connected to one end of the optical fiber preform, thereby fixing the optical fiber preform, the preform rod connecting rod is hollow inside and connected to the hollow part of the optical fiber preform, and the other end of the optical fiber preform is sealed; one end of the air path connector is connected to the air pump, and the other end is connected to the hollow part of the preform rod connecting rod, thereby controlling the increase or decrease of the internal pressure of the optical fiber preform; the above multiple components can simultaneously control the optical fiber preform to achieve its multi-dimensional stable movement;

[0014] The working process of the preform suspension system is as follows:

[0015] The optical fiber preform is sealed and fixed by the preform connecting rod, and the preform connecting rod is connected to the air pump through the air circuit joint; the optical fiber preform is controlled by the vertical feeding motor and the precision screw to realize the up and down movement of the Z axis, and the optical fiber preform is controlled by the suspension arm to realize the forward, backward, left and right movement of the XY axis; the optical fiber preform is controlled by the axial torsion motor and the preform connecting rod to realize the torsion movement of the R axis; the optical fiber preform is controlled to realize the movement of the four dimensions of XYZR by the simultaneous operation of the vertical feeding motor to the air circuit joint, and the air pressure contraction or expansion of the internal space of the optical fiber preform is regulated.

[0016] Further, the special wire drawing furnace comprises: an upper furnace mouth fixing ring, an upper openable and closable sealed cavity cover, a furnace shell, an insulation layer, a replaceable heating body, a heating body support platform, a lower sealed cavity cover, a lower furnace mouth fixing ring and an atmosphere system;

[0017] Among them, the furnace shell is the main body of the special wire drawing furnace, and the replaceable heating body runs through the center of the furnace shell; the furnace shell and the replaceable heating body are filled with an insulation layer; the lower part of the replaceable heating body is embedded and fixed on the heating body support platform; the outer ring surface of the heating body support platform is in contact with the inner ring surface of the insulation layer, and the bottom surface of the heating body support platform is in contact with the lower sealed cavity cover; the lower furnace mouth fixing ring is tightly fixed to the lower surface of the lower sealed cavity cover by high temperature resistant bolts; the atmosphere system is located inside the lower sealed cavity cover and connected to the external gas; the upper furnace mouth fixing ring is fixed to the upper openable and closable sealed cavity cover, and is located on the top of the furnace shell and in contact with it;

[0018] The working process of the special wire drawing furnace is as follows:

[0019] First, select a matching replaceable heating element, open the upper sealed cavity cover and insert the replaceable heating element;

[0020] Then, turn on the wire drawing furnace PID self-tuning function in the integrated control system. The PID self-tuning function can realize the automatic calibration and correction of the temperature control accuracy of the wire drawing furnace, and is the self-correction of the internal software parameters of the integrated control system.

[0021] Subsequently, the protective gas is filled into the replaceable heating body through the atmosphere system;

[0022] Finally, the heating rate is set, the replaceable heating element is powered on to generate heat, and then the special wire drawing furnace starts to work and heat up.

[0023] Furthermore, the replaceable heating body comprises a protective outer sleeve, a high temperature resistance type heating material and a wire winding tube;

[0024] In the replaceable heating body, the wire winding tube is located in the center, the high temperature resistance type heating material is surrounded by the outside of the wire winding tube and is closely fitted with the wire winding tube, and the protective outer sleeve is located outside the high temperature resistance type heating material;

[0025] The protective outer sleeve, high temperature resistance heating material and wire winding tube are coaxial structures, which can be quickly replaced as a whole after assembly to adjust the temperature field distribution of the special wire drawing furnace.

[0026] Further, the high temperature resistance type heating material is a resistance type heating material, including electric heating wire, double helix silicon carbon tube or graphite;

[0027] Depending on the different replaceable heating elements, the working temperature of the special wire drawing furnace is 100~2000℃, and the heating rate is 1~35℃ / min;

[0028] When the resistance heating material is electric heating wire, the working temperature of the special wire drawing furnace is 100~900℃;

[0029] When the resistance heating material is double helix silicon carbon tube, the working temperature of the special wire drawing furnace is 800~1500℃;

[0030] When the resistance heating material is graphite, the operating temperature of the special wire drawing furnace is 1400~2000 ℃.

[0031] Furthermore, the caliber of the replaceable heating body is 35-75 mm, which is suitable for special preform rods with a diameter of 10-60 mm.

[0032] Furthermore, an atmosphere system is provided inside the sealed cavity cover at the lower part of the drawing furnace, wherein a gas supply pipe faces the outside of the furnace shell and is connected to the external gas, and the required gas can be introduced through the gas supply pipe, and the air inlet hole faces the inside of the replaceable heating body, and the gas is passed into the inside of the replaceable heating body through the air inlet hole;

[0033] In the atmosphere system, three gas supply pipes are evenly distributed at an angle of 120° inside the lower sealed chamber cover. There are 12 air inlet holes, evenly distributed at an angle of 30° on the inner ring edge of the lower sealed chamber cover. The diameter of the air inlet hole is 3 mm, and the center of the circle is 5 mm away from the inner ring edge of the lower sealed chamber cover.

[0034] Furthermore, the wire diameter control system includes a bare fiber wire diameter gauge and a traction motor; the bare fiber wire diameter gauge is located 0.5 to 1 m below the special wire drawing furnace, and the traction motor is located below the bare fiber wire diameter gauge;

[0035] The working process of the wire diameter control system is as follows:

[0036] The optical fiber preform rod, which has been heated and softened in a special drawing furnace, is placed in the traction motor to maintain a stable feeding speed and drawing speed to form a stable drawing state; the integrated control system regulates the drawing speed of the traction motor, and at the same time monitors the bare fiber diameter through the bare fiber diameter meter to ensure that the bare fiber diameter is within the set range.

[0037] Furthermore, the optical fiber coating system includes: a coating mold, a UV curing device and a coated optical fiber wire diameter gauge; the coating mold is located below the bare fiber wire diameter gauge, the UV curing device is located below the coating mold, and the coated optical fiber wire diameter gauge is located below the UV curing device; the entire optical fiber coating system is located between the bare fiber wire diameter gauge and the traction motor;

[0038] The working process of the optical fiber coating system is as follows:

[0039] The optical fiber prepared by the wire diameter control system enters the coating mold, so that the surface of the optical fiber is wrapped by the organic polymer; the coated optical fiber passes through the UV curing device, and the coating layer on the surface of the optical fiber is rapidly cured under the irradiation of ultraviolet rays to obtain a finished optical fiber; the integrated control system monitors the diameter of the coated optical fiber through the coated optical fiber wire diameter meter and measures the coating thickness.

[0040] Furthermore, the wire collection system comprises a guide wheel, a traction wheel and a wire collection drum;

[0041] In the wire collection system, the guide wheel, traction wheel and wire collection drum are arranged in series. The specific working process is as follows:

[0042] The finished optical fiber is redirected by a guide wheel, and then passes through a traction wheel and is connected to a take-up drum, which winds and stores the finished optical fiber.

[0043] Furthermore, when drawing a helical optical fiber, after the drawing temperature and speed are stabilized, the optical fiber preform is controlled by an axial torsion motor to achieve R-axis rotation, and then a special helical optical fiber with periodic torsion characteristics can be drawn as required.

[0044] The special optical fiber drawing tower described in the present invention is a special drawing furnace based on a modular design. It can independently select appropriate heating bodies, optimize the drawing temperature field distribution, and can continuously and stably draw special material composite optical fibers. At the same time, based on its preform rod suspension system, it can control the XYZR multi-dimensional stable movement of the preform rod, thereby realizing the drawing of special structure composite optical fibers. Compared with the traditional integrated drawing tower, the drawing temperature field of the special optical fiber drawing tower described in the present invention can be adjusted according to the characteristics of the preform rod, and the replaceable heating body can be replaced quickly; and it can realize the long-distance and efficient drawing of spiral optical fibers, effectively solving the problem of difficulty in drawing special material composite optical fibers, special structure composite optical fibers or other special fibers.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The special optical fiber drawing furnace of the present invention adopts a modular design, and a heating body matching the characteristics of different special preform rods can be selected to achieve accurate control of the drawing temperature, heating rate and temperature field distribution range, so as to draw the special material composite optical fiber uniformly, continuously and efficiently.

[0047] (2) The preform suspension system of the present invention can realize multi-dimensional motion control of the preform, including coordinated control of horizontal, vertical and torsional motion states, and realize long-distance and efficient drawing of special structure composite optical fibers.

[0048] (3) The special glass optical fiber drawing tower of the present invention has a wide range of applications and is compatible with special optical fiber preforms with a diameter of 10 to 60 mm; bare fiber diameters of 80 to 250 μm and coated fiber diameters of 100 to 350 μm; and an operating temperature range of 100 to 2000 °C. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a structural block diagram of the special optical fiber drawing tower described in Example 1;

[0050] Figure 2a It is a schematic cross-sectional structure diagram of the special wire drawing furnace described in Example 2;

[0051] Figure 2b Different viewing angles of the cross-sectional structure of the special wire drawing furnace described in Example 2;

[0052] Figure 3 This is a schematic diagram of the 35 mm caliber replaceable heating body described in Example 2, and the wire drawing case of the wire drawing tower in this state;

[0053] Figure 4 This is a schematic diagram of a 55 mm caliber replaceable heating body and a wire drawing tower in this state as described in Example 3;

[0054] Figure 5 This is a schematic diagram of a 75 mm caliber replaceable heating body and a wire drawing tower in this state as described in Example 4;

[0055] Figure 6 Schematic diagram of the special spiral optical fiber drawing case described in Example 5. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and drawings, but the present invention is not limited to the embodiments.

[0057] Embodiment 1:

[0058] A special optical fiber drawing tower, comprising: a preform suspension system 1, a special drawing furnace 2, an integrated control system 3, a wire diameter control system 4, an optical fiber coating system 5 and a wire collection system 6;

[0059] The preform suspension system 1, the special drawing furnace 2, the wire diameter control system 4, the optical fiber coating system 5 and the wire collection system 6 are multiple subsystems at the same level; the integrated control system 3 is a higher-level system, which monitors the working status and operating parameters of each subsystem in real time. After the working parameters of each subsystem are fed back to each other, the integrated control system 3 actively or passively corrects the working status of each subsystem based on the operating parameters, and finally realizes the operation of the drawing tower; the working process of the drawing tower is as follows:

[0060] First, the optical fiber preform is fixed to the preform suspension system 1, and the preform suspension system 1 controls the movement of the optical fiber preform;

[0061] Secondly, the optical fiber preform is fed into the special drawing furnace 2, and the special drawing furnace 2 is heated to soften the optical fiber preform to reach the drawing state;

[0062] Then, the fiber preform softened by the special drawing furnace 2 is drawn by the wire diameter control system 4 and the wire diameter is controlled to obtain an optical fiber of the required specification;

[0063] Finally, the optical fiber is coated and wound for storage by the optical fiber coating system 5 and the wire collection system 6 .

[0064] Furthermore, the preform suspension system 1 comprises a vertical feeding motor 101, a precision lead screw 102, a suspension arm 103, an axial torsion motor 104, a preform connecting rod 105 and an air path joint 106;

[0065] Among them, the vertical feeding motor 101 and the precision screw 102 are tightly connected through a coupling, and the vertical feeding motor 101 can drive the precision screw 102 to rotate at a constant speed; one end of the suspension arm 103 is meshed with the precision screw 102 through a gear, and the other end is connected to the axial torsion motor 104. The rotation of the precision screw 102 can control the suspension arm 103 to move up and down at a constant speed. The suspension arm 103 is a double-layer structure and can slide in both directions forward, backward, left and right; the axial torsion motor 104 and the preform rod connecting rod 105 are tightly connected through a flange, and the axial torsion motor 104 can drive the preform rod to rotate. The preform rod connecting rod 105 is twisted concentrically to control the twisting of the optical fiber preform rod; the preform rod connecting rod 105 is sealed and connected to one end of the optical fiber preform rod to fix the optical fiber preform rod, the preform rod connecting rod 105 is hollow inside and communicated with the hollow part of the optical fiber preform rod, and the other end of the optical fiber preform rod is sealed; one end of the air circuit connector 106 is connected to the air pump, and the other end is connected to the hollow part of the preform rod connecting rod 105, thereby controlling the increase or decrease of the internal pressure of the optical fiber preform rod; the above multiple components can simultaneously control the optical fiber preform rod to achieve its multi-dimensional stable movement;

[0066] The working process of the preform suspension system 1 is as follows:

[0067] The optical fiber preform is sealed and fixed by the preform connecting rod 105, and the preform connecting rod 105 is connected to the air pump through the air circuit joint 106; the optical fiber preform is controlled by the vertical feeding motor 101 and the precision screw 102 to realize the up and down movement of the Z axis, and the optical fiber preform is controlled by the suspension arm 103 to realize the forward, backward, left and right movement of the XY axis; the optical fiber preform is controlled by the axial torsion motor 104 and the preform connecting rod 105 to realize the torsion movement of the R axis; the vertical feeding motor 101 to the air circuit joint 106 are operated simultaneously to control the optical fiber preform to realize the four-dimensional movement of XYZR, and adjust the air pressure contraction or expansion of the internal space of the optical fiber preform.

[0068] Furthermore, if Figure 2a , Figure 2b As shown, the special wire drawing furnace 2 includes: an upper furnace mouth fixing ring 201, an upper openable and closable sealed cavity cover 202, a furnace shell 203, an insulation layer 204, a replaceable heating body 205, a heating body support platform 206, a lower sealed cavity cover 207, a lower furnace mouth fixing ring 208 and an atmosphere system 209;

[0069] Among them, the furnace shell 203 is the main body of the special wire drawing furnace 2, and the replaceable heating body 205 runs through the center of the furnace shell 203; the insulation layer 204 is filled between the furnace shell 203 and the replaceable heating body 205; the lower part of the replaceable heating body 205 is embedded and fixed on the heating body support platform 206; the outer ring surface 2061 of the heating body support platform 206 is in contact with the inner ring surface of the insulation layer 204, and the bottom surface 2062 of the heating body support platform 206 is in contact with the lower sealed cavity cover 207; the lower furnace mouth fixing ring 208 is tightly fixed to the lower surface of the lower sealed cavity cover 207 by high temperature resistant bolts; the atmosphere system 209 is located inside the lower sealed cavity cover 207 and is connected to the external gas; the upper furnace mouth fixing ring 201 is fixed to the upper openable and closable sealed cavity cover 202, and is located at the top of the furnace shell 203 and is in contact with it;

[0070] The working process of special wire drawing furnace 2 is as follows:

[0071] First, select a matching replaceable heating body 205, open the upper openable and closable sealed cavity cover 202 and insert the replaceable heating body 205;

[0072] Then, turn on the PID self-tuning function of the wire drawing furnace in the integrated control system 3. The PID self-tuning function can realize automatic calibration and correction of the temperature control accuracy of the wire drawing furnace, and is a self-correction of the internal software parameters of the integrated control system. PID control is a very commonly used control principle in the fields of machinery, electric heating, etc. The controller controls the real-time working status of the system through three parameters. PID self-tuning means that the system self-regulates the three parameters of PID by monitoring its own working status to achieve a stable working state. In this embodiment, it is to calibrate and correct the temperature and temperature control accuracy of the wire drawing furnace to avoid temperature fluctuations, overloads, lags, etc.

[0073] Subsequently, protective gas is charged into the replaceable heating body 205 through the atmosphere system 209;

[0074] Finally, the heating rate is set, and the switch is turned on, and the replaceable heating body 205 is powered on and heated, and then the special wire drawing furnace 2 starts to work and heat up.

[0075] Furthermore, the replaceable heating body 205 includes a protective outer sleeve 2051, a high temperature resistance type heating material 2052 and a wire winding tube 2053;

[0076] In the replaceable heating body 205, the wire winding tube 2053 is located in the center, the high temperature resistance type heating material 2052 is surrounded by the outside of the wire winding tube 2053 and is closely attached to the wire winding tube 2053, and the protective outer sleeve 2051 is located outside the high temperature resistance type heating material 2052;

[0077] The protective outer sleeve 2051 , the high temperature resistance type heating material 2052 and the wire winding tube 2053 are coaxial structures, and after assembly, they can be quickly replaced as a whole to adjust the temperature field distribution of the special wire drawing furnace 2 .

[0078] Further, the high temperature resistance type heating material 2052 is a resistance type heating material, including electric heating wire, double helix silicon carbon tube or graphite;

[0079] According to different replaceable heating bodies 205, the working temperature of the special wire drawing furnace 2 is 100~2000℃, and the heating rate is 1~35℃ / min;

[0080] When the resistance type heating material 2052 is an electric heating wire, the working temperature of the special wire drawing furnace 2 is 100~900℃;

[0081] When the resistance type heating material 2052 is a double helix silicon carbon tube, the working temperature of the special wire drawing furnace 2 is 800-1500°C;

[0082] When the resistance heating material 2052 is graphite, the working temperature of the special wire drawing furnace 2 is 1400~2000°C.

[0083] Furthermore, the caliber of the replaceable heating body 205 is 35-75 mm, which is suitable for special preform rods with a diameter of 10-60 mm.

[0084] Furthermore, an atmosphere system 209 is provided inside the sealed chamber cover 207 at the lower part of the drawing furnace, wherein a gas supply pipe 2092 faces the outside of the furnace shell 203 and is connected to the external gas, and the required gas can be introduced through the gas supply pipe 2092, and the gas inlet hole 2091 faces the inside of the replaceable heating body 205, and the gas is passed into the inside of the replaceable heating body 205 through the gas inlet hole 2091;

[0085] In the atmosphere system 209, three gas supply pipes 2092 are evenly distributed at an angle of 120° inside the lower sealed chamber cover 207. There are 12 air inlet holes 2091, which are evenly distributed at an angle of 30° on the inner ring edge of the lower sealed chamber cover 207. The diameter of the air inlet hole 2091 is 3 mm, and the center of the circle is 5 mm away from the inner ring edge of the lower sealed chamber cover 207.

[0086] Furthermore, the wire diameter control system 4 includes a bare fiber wire diameter gauge 401 and a traction motor 402; the bare fiber wire diameter gauge 401 is located 0.5 to 1 m below the special wire drawing furnace 2, and the traction motor 402 is located below the bare fiber wire diameter gauge 401;

[0087] The working process of the wire diameter control system 4 is as follows:

[0088] The optical fiber preform rod heated and softened by the special drawing furnace 2 is placed in the traction motor 402 to form a stable drawing state; the integrated control system 3 adjusts the drawing speed of the traction motor 402, and at the same time monitors the bare fiber diameter through the bare fiber diameter meter 401, so that the bare fiber diameter is within the set range.

[0089] Furthermore, the optical fiber coating system 5 includes: a coating mold 501, a UV curing device 502 and a coated optical fiber wire diameter meter 503; the coating mold 501 is located below the bare fiber wire diameter meter 401, the UV curing device 502 is located below the coating mold 501, and the coated optical fiber wire diameter meter 503 is located below the UV curing device 502; the entire optical fiber coating system 5 is located between the bare fiber wire diameter meter 401 and the traction motor 402;

[0090] The working process of the optical fiber coating system 5 is as follows:

[0091] The optical fiber prepared by the aforementioned wire diameter control system 4 enters the coating mold 501, so that the surface of the optical fiber is wrapped by the organic polymer; the coated optical fiber passes through the UV curing device 502, and the coating layer on the surface of the optical fiber is rapidly cured under the irradiation of ultraviolet rays to obtain a finished optical fiber; the integrated control system 3 monitors the diameter of the coated optical fiber through the coated optical fiber wire diameter meter 503 to measure the coating thickness.

[0092] Furthermore, the wire collection system 6 includes a guide wheel 601, a traction wheel 602 and a wire collection drum 603;

[0093] In the wire collection system 6, the guide wheel 601, the traction wheel 602 and the wire collection drum 603 are arranged in series, and the specific working process is as follows:

[0094] The finished optical fiber is redirected by the guide wheel 601, and then passes through the traction wheel 602 and is connected to the wire-collecting drum 603, which winds and stores the finished optical fiber.

[0095] Furthermore, when drawing a helical optical fiber, after the drawing temperature and speed are stabilized, the optical fiber preform is controlled by the axial torsion motor 104 to realize R-axis rotation, and then a special helical optical fiber with periodic torsion characteristics can be drawn as required.

[0096] The special optical fiber drawing tower described in this embodiment adopts a modular design scheme, and multiple systems can coordinate and control the precise operation of the drawing tower. In particular, its special drawing furnace system has the ability to quickly adjust the temperature field and thermal system, and the rod suspension system has the function of multi-dimensionally controlling the movement of preform rods. The special optical fiber drawing tower is suitable for special material composites and special structure composite optical fibers, and is a precision device for preparing special fibers.

[0097] Embodiment 2:

[0098] This embodiment provides a 35 mm caliber replaceable heating body 205 and an assembled special drawing tower wire drawing case.

[0099] Reference Figure 3 First, a modular replaceable heating body 205 suitable for special optical fiber drawing furnace is provided, which is composed of a protective outer sleeve 2051, a high temperature resistance type heating material 2052 and a wire winding tube 2053. The wire winding tube 2053 has a diameter of 35 mm, the high temperature resistance type heating material 2052 is an electric heating wire with a winding height of 30 mm, and the outer diameter of the protective outer sleeve 2051 is 100 mm. The modular replaceable heating body 205 is suitable for special preforms with a diameter of 10 to 30 mm.

[0100] Secondly, if Figure 3 In (a), this embodiment also provides a wire drawing case of a special wire drawing tower equipped with a 35 mm diameter heater. In the wire drawing case, the preform is made of germanate glass material, has a step-type structure, and an outer diameter of 10 mm. Figure 3 (b) in the figure.

[0101] When drawing wire, the operation process of the drawing tower is as follows:

[0102] (1) Open the upper retractable sealed cavity cover 202 of the special wire drawing furnace 2, insert the replaceable heating body 205 described in this embodiment, and start the PID self-tuning function of the wire drawing furnace to automatically optimize the temperature control accuracy of the wire drawing furnace;

[0103] (2) After setting the temperature field of the special wire drawing furnace, the preform rod is fixed to the preform rod suspension system 1, and the preform rod is sent to the high temperature zone of the special wire drawing furnace 2 through the suspension system 1; Ar gas protection is filled into the replaceable heating body 205 (inside the furnace chamber), and the temperature is raised to the drawing temperature of 790°C at a rate of 10°C / min; after the preform rod is softened, the wire root is led out by the lower furnace mouth fixing ring 208 of the special wire drawing furnace 2 and enters the wire diameter control system 4.

[0104] (3) The wire drawing is stabilized and the fiber diameter is regulated by the wire diameter control system 4. The final controlled wire drawing parameters are: feeding speed 1 mm / min, wire drawing speed about 15.63 m / s, such as Figure 3 In (c), the bare fiber diameter is 100 μm.

[0105] Figure 3 (b) and (c) respectively show the schematic diagram of the taper region of the special germanate glass preform and the finished optical fiber under the drawing temperature field of this embodiment. The schematic diagram of the cross section of the obtained optical fiber is shown in Figure 3 In (c), from outside to inside, there are cladding 0301 and core 0302. The 35 mm caliber replaceable heating body described in this embodiment can realize the rapid switching of the temperature field of the drawing tower. The drawing case shows that the heating body is suitable for the drawing of special preform rods with a diameter of 10-30 mm.

[0106] Embodiment 3:

[0107] This embodiment provides a 55 mm diameter replaceable heating body and an assembled special drawing tower wire drawing case.

[0108] Reference Figure 4 First, a modular replaceable heating body 205 suitable for special optical fiber drawing furnace is provided, which is composed of a protective outer sleeve 2051, a high temperature resistance type heating material 2052 and a wire winding tube 2053. The wire winding tube 2053 has a diameter of 55 mm, the high temperature resistance type heating material 2052 is a graphite electric heating material with a winding height of 60 mm, and the outer diameter of the protective outer sleeve 2051 is 100 mm. The replaceable heating body 205 is suitable for special preforms with a diameter of 30-40 mm.

[0109] Secondly, if Figure 4 In (a), this embodiment also provides a wire drawing case of a special wire drawing tower equipped with a 55 mm diameter heating body. Figure 4 In (b), in the wire drawing case, the preform is made of quartz glass material, has a double cladding structure, and has an outer diameter of 40 mm.

[0110] When drawing wire, the operation process of the drawing tower is as follows:

[0111] (1) Open the upper retractable sealed cavity cover 202 of the special wire drawing furnace 2, insert the replaceable heating body 205 described in this embodiment, and start the PID self-tuning function of the wire drawing furnace to automatically optimize the temperature control accuracy of the wire drawing furnace;

[0112] (2) After setting the temperature field of the special wire drawing furnace, the preform rod is fixed to the preform rod suspension system 1, and the preform rod is sent to the high temperature zone of the special wire drawing furnace 2 through the suspension system 1; He / Ar mixed gas is filled into the replaceable heating body 205 (inside the furnace chamber) for protection, and the temperature is raised to 2000°C drawing temperature at a rate of 35°C / min; after the preform rod is softened, the wire root is led out by the lower furnace mouth fixing ring 208 of the special wire drawing furnace 2 and enters the wire diameter control system 4.

[0113] (3) The wire drawing is stabilized and the fiber diameter is regulated by the wire diameter control system 4. The special optical fiber is coated by the fiber coating system 5, and the coating mold controls the coating thickness. The final controlled drawing parameters are: feeding speed 0.5 mm / min, drawing speed about 12.8 m / s, bare fiber diameter 250 μm, and coating layer diameter 350 μm.

[0114] Figure 4 The following is a schematic diagram of the taper region of the special double-clad quartz glass preform and a schematic diagram of the finished optical fiber under the drawing temperature field of this embodiment. Figure 4 In (c), from outside to inside, there are coating layer 0401, outer cladding layer 0402, inner cladding layer 0403 and core 0404. The 55 mm caliber replaceable heating body described in this embodiment can realize the rapid switching of the temperature field of the drawing tower. The drawing case shows that the heating body is suitable for the drawing of special preform rods with a diameter of 30-40 mm.

[0115] Embodiment 4:

[0116] This embodiment provides a 75 mm caliber replaceable heating body and an assembled special drawing tower wire drawing case.

[0117] Reference Figure 5 First, a modular replaceable heating body 205 suitable for a special optical fiber drawing furnace is provided, which is composed of a protective outer sleeve 2051, a high temperature resistance type heating material 2052 and a wire winding tube 2053. The wire winding tube 2053 has a diameter of 75 mm, the high temperature resistance type heating material 2052 is an electric heating wire with a winding height of 80 mm, and the outer diameter of the protective outer sleeve 2051 is 100 mm. The modular replaceable heating body 205 is suitable for special preforms with a diameter of 40 to 60 mm.

[0118] Secondly, if Figure 5 In (a), this embodiment also provides a wire drawing case of a special wire drawing tower equipped with a 75 mm diameter heating body. Figure 5 In (b), in the wire drawing case, the preform is made of polymer material, has a photonic crystal structure, and has an outer diameter of 60 mm.

[0119] When drawing wire, the operation process of the drawing tower is as follows:

[0120] (1) Open the upper retractable sealed cavity cover 202 of the special wire drawing furnace 2, insert the replaceable heating body 205 described in this embodiment, and start the PID self-tuning function of the wire drawing furnace to automatically optimize the temperature control accuracy of the wire drawing furnace;

[0121] (2) After setting the temperature field of the special wire drawing furnace, the preform is fixed to the preform suspension system 1, and the preform is sent to the high temperature zone of the special wire drawing furnace 2 through the suspension system 1; N is charged into the replaceable heating body 205 (inside the furnace); 2 Protection, the temperature is raised to the drawing temperature of 150°C at a rate of 1°C / min; after the preform is softened, the wire root is led out by the lower furnace mouth fixing ring 208 of the special drawing furnace 2 and enters the wire diameter control system 4.

[0122] (3) The wire drawing is stabilized and the fiber diameter is regulated by the wire diameter control system 4. The final controlled wire drawing parameters are: feeding speed 0.2 mm / min, wire drawing speed about 18 m / s, and the obtained polymer fiber diameter is 200 μm. Figure 5 (c) in.

[0123] Figure 5 The schematic diagram of the taper region of the special photonic crystal polymer material preform and the schematic diagram of the finished optical fiber under the drawing temperature field of this embodiment are given. The schematic diagram of the cross section of the obtained optical fiber is shown in Figure 5 In (c), from outside to inside, there are solid outer cladding 0501, air hole inner cladding 0502 and fiber core 0503. The 55 mm caliber replaceable heating body described in this embodiment can realize the rapid switching of the temperature field of the drawing tower. The drawing case shows that the heating body is suitable for the drawing of special preforms with a diameter of 40-60 mm, and the special drawing of the present invention is suitable for structural composite special preforms with complex structures, such as the photonic crystal fiber described in this example.

[0124] Embodiment 5:

[0125] This embodiment provides a drawing operation case of a helical composite optical fiber based on the special drawing tower described in Embodiments 1 to 4. In the drawing case, the preform is made of phosphate glass material, has a double-core structure, and an outer diameter of 30 mm.

[0126] When drawing wire, the specific process is as follows:

[0127] (1) Open the upper retractable sealed cavity cover 202 of the special wire drawing furnace 2, insert the replaceable heating body 205 with a diameter of 35 mm, and start the PID self-tuning function of the wire drawing furnace to automatically optimize the temperature control accuracy of the wire drawing furnace;

[0128] (2) After setting the temperature field of the special wire drawing furnace, the preform is fixed to the preform suspension system 1, and the preform is sent to the high temperature zone of the special wire drawing furnace 2 through the suspension system 1; N is charged into the replaceable heating body 205 (inside the furnace); 2 protection, and the temperature is raised to the drawing temperature of 650°C at a rate of 5°C / min; after the preform rod is softened, the wire root is led out by the lower furnace mouth fixing ring 208 of the special wire drawing furnace 2 and enters the wire diameter control system 4.

[0129] (3) The fiber diameter d is gradually adjusted by the fiber diameter control system 4, and the drawing speed V is stabilized. 1 After the fiber diameter and drawing speed are stable, the axial torsion motor 104 in the preform suspension system 1 is turned on, and the speed V of the axial torsion motor 104 is adjusted. 2 , then the pitch of the helical fiber is .

[0130] The final drawing parameters are: feeding speed 0.1 mm / min, drawing speed V 1 is 5.76 m / s, and the rotation speed of the torsion motor V 1 The speed is 10 turns / s; the diameter of the obtained spiral fiber is 125 μm and the pitch is about 0.58m.

[0131] (4) Fiber optic collection: The optical fiber is wrapped and packaged by the collection system 6.

[0132] Figure 6 Given the drawing temperature field, drawing speed, and preform rod twisting speed of this embodiment, Figure 6 (a) in the figure shows the preform taper region of the special helical structure optical fiber and the finished optical fiber. The obtained optical fiber cross-section diagram is shown in Figure 6 (b), from outside to inside, it is cladding 0601, spiral side core 0602 and core 0603. The case of drawing spiral structure composite optical fiber described in this embodiment shows that the special optical fiber drawing tower provided by the present invention has the ability to draw special optical fiber with axial structure twisting change, and the pitch generated by axial twisting is determined by the drawing speed and the speed of the twisting motor. The drawing tower of the present invention can solve the problem that it is difficult to draw axial twisted special optical fiber uniformly at high speed over a long distance.

[0133] The above-mentioned embodiments only express several implementation methods of the present invention, but should not be understood as limiting the protection scope of this patent. It should be pointed out that for those skilled in the art to which the present invention belongs, the supplement or optimization made to the present invention without departing from the concept of the present invention still falls within the protection scope of the present invention.

Claims

1. A special optical fiber drawing tower, characterized in that: include: Preform rod suspension system (1), special wire drawing furnace (2), integrated control system (3), wire diameter control system (4), optical fiber coating system (5) and wire collection system (6); The preform rod suspension system (1), the special wire drawing furnace (2), the wire diameter control system (4), the optical fiber coating system (5) and the wire collection system (6) are multiple subsystems at the same level; the integrated control system (3) is a higher-level system that monitors the working state and operating parameters of each subsystem in real time. After the working parameters of each subsystem are fed back to each other, the integrated control system (3) corrects the working state of each subsystem based on the operating parameters, and finally realizes the operation of the wire drawing tower; The preform rod suspension system (1) is used to fix the optical fiber preform rod and control the optical fiber preform rod to achieve multi-dimensional movement; the special drawing furnace (2) is used to soften the optical fiber preform rod to reach the drawing state; the wire diameter control system (4) is used to draw the optical fiber preform rod softened by the special drawing furnace (2) and control the wire diameter to obtain an optical fiber of required specifications; the optical fiber coating system (5) is used to coat the optical fiber, and the wire collection system (6) is used to coat the optical fiber and store the wire in a winding manner; The special wire drawing furnace (2) comprises: an upper furnace mouth fixing ring (201), an upper openable and closable sealed cavity cover (202), a furnace shell (203), a heat insulation layer (204), a replaceable heating body (205), a heating body support platform (206), a lower sealed cavity cover (207), a lower furnace mouth fixing ring (208) and an atmosphere system (209); The furnace shell (203) is the main body of the special wire drawing furnace (2), and the replaceable heating body (205) runs through the center of the furnace shell (203); the furnace shell (203) and the replaceable heating body (205) are filled with an insulation layer (204); the lower part of the replaceable heating body (205) is embedded and fixed on the heating body support platform (206); the outer ring surface of the heating body support platform (206) is in contact with the inner ring surface of the insulation layer (204), and the bottom surface of the heating body support platform (206) is in contact with the lower sealing cavity cover (207); the lower furnace mouth fixing ring (208) is tightly fixed to the lower surface of the lower sealing cavity cover (207) by high temperature resistant bolts. ; The atmosphere system (209) is located inside the lower sealed chamber cover (207) and is connected to the outside gas; the upper furnace mouth fixing ring (201) is fixed to the upper openable and closable sealed chamber cover (202) and is located on the top of the furnace shell (203) and fits therewith; the replaceable heating body (205) is inserted from the upper openable and closable sealed chamber cover (202); the wire drawing furnace PID self-tuning function in the integrated control system (3) realizes automatic calibration and correction of the temperature control accuracy of the wire drawing furnace; the protective gas is filled into the replaceable heating body (205) through the atmosphere system (209); the replaceable heating body (205) is powered on and generates heat at a set heating rate; The replaceable heating body (205) comprises a protective outer sleeve (2051), a high-temperature resistance-type heating material (2052) and a wire winding tube (2053); In the replaceable heating body (205), the wire winding tube (2053) is located at the center, the high-temperature resistance type heating material (2052) is surrounded by the outside of the wire winding tube (2053) and is tightly fitted with the wire winding tube (2053), and the protective outer sleeve (2051) is located outside the high-temperature resistance type heating material (2052); The protective outer sleeve (2051), the high-temperature resistance type heating material (2052) and the wire winding tube (2053) are coaxial structures and can be replaced as a whole after assembly to adjust the temperature field distribution of the special wire drawing furnace (2).

2. A special optical fiber drawing tower according to claim 1, characterized in that: The preform rod suspension system (1) comprises a vertical feeding motor (101), a precision lead screw (102), a suspension arm (103), an axial torsion motor (104), a preform rod connecting rod (105), and an air path joint (106); The vertical feeding motor (101) and the precision lead screw (102) are connected via a coupling, driving the precision lead screw (102) to rotate at a constant speed; one end of the suspension arm (103) is meshed with the precision lead screw (102) via a gear, and the other end is connected to the axial torsion motor (104), and the rotation of the precision lead screw (102) controls the suspension arm (103) to move up and down at a constant speed; the suspension arm (103) is a double-layer structure, and can slide in both directions, front and back, left and right; the axial torsion motor (104) and the preform rod connecting rod (105) are connected via a flange, and the axial torsion motor (104) drives the preform rod connecting rod (105) to twist concentrically, thereby controlling the twisting of the optical fiber preform; the preform rod connecting rod (105) is sealed and connected to one end of the optical fiber preform, thereby fixing the optical fiber preform, and the interior of the preform rod connecting rod (105) The optical fiber preform is hollow and communicated with the hollow part of the optical fiber preform, and the other end of the optical fiber preform is sealed; one end of the air path connector (106) is connected to the air pump, and the other end is connected to the hollow part of the preform connecting rod (105), thereby controlling the increase or decrease of the internal pressure of the optical fiber preform; the optical fiber preform is controlled to achieve Z-axis up and down movement through the vertical feeding motor (101) and the precision lead screw (102), and the optical fiber preform is controlled to achieve XY-axis forward and backward left and right movement through the suspension arm (103); the optical fiber preform is controlled to achieve R-axis torsional movement through the axial torsion motor (104) and the preform connecting rod (105); and the optical fiber preform is controlled to achieve XYZR four-dimensional movement through the simultaneous operation of the vertical feeding motor (101) to the air path connector (106), and the air pressure contraction or expansion of the internal space of the optical fiber preform is regulated.

3. A special optical fiber drawing tower according to claim 1, characterized in that: The high temperature resistance type heating material (2052) is a resistance type heating material, including a heating wire, a double helix silicon carbon tube or graphite; The working temperature of the special wire drawing furnace (2) is 100-2000°C, and the heating rate is 1-35°C / min; When the resistance-type heating material (2052) is an electric heating wire, the working temperature of the special wire drawing furnace (2) is 100-900°C; When the resistance-type heating material (2052) is a double-helix silicon carbon tube, the working temperature of the special wire drawing furnace (2) is 800-1500°C; When the resistance-type heating material (2052) is graphite, the operating temperature of the special wire drawing furnace (2) is 1400-2000°C.

4. A special optical fiber drawing tower according to claim 1, characterized in that: The caliber of the replaceable heating body (205) is 35-75 mm.

5. The special optical fiber drawing tower according to claim 1, characterized in that: An atmosphere system (209) is provided inside the sealed chamber cover (207) at the lower part of the drawing furnace. The gas supply pipe (2092) of the atmosphere system (209) faces the outside of the furnace shell (203) and is connected to the external gas. The required gas can be introduced through the gas supply pipe (2092). The gas inlet hole (2091) faces the inside of the replaceable heating body (205). The gas is passed into the inside of the replaceable heating body (205) through the gas inlet hole (2091); In the atmosphere system (209), three gas supply pipes (2092) are evenly distributed at an angle of 120° inside the lower sealed chamber cover (207), and there are 12 air inlet holes (2091) evenly distributed at an angle of 30° on the inner ring edge of the lower sealed chamber cover (207). The diameter of the air inlet holes (2091) is 3 mm, and the center of the circle is 5 mm away from the inner ring edge of the lower sealed chamber cover (207).

6. A special optical fiber drawing tower according to claim 1, characterized in that: The wire diameter control system (4) comprises a bare fiber wire diameter gauge (401) and a traction motor (402); the bare fiber wire diameter gauge (401) is located 0.5 to 1 m below the special wire drawing furnace (2), and the traction motor (402) is located below the bare fiber wire diameter gauge (401); the optical fiber preform rod heated and softened by the special wire drawing furnace (2) is placed in the traction motor (402) to form a stable wire drawing state; the integrated control system (3) regulates the wire drawing speed of the traction motor (402) and simultaneously monitors the bare fiber wire diameter through the bare fiber wire diameter gauge (401), so that the bare fiber wire diameter is within a set range.

7. A special optical fiber drawing tower according to claim 6, characterized in that: The optical fiber coating system (5) comprises: a coating mold (501), a UV curing device (502) and a coated optical fiber wire diameter meter (503); the coating mold (501) is located below the bare fiber wire diameter meter (401), the UV curing device (502) is located below the coating mold (501), and the coated optical fiber wire diameter meter (503) is located below the UV curing device (502); the entire optical fiber coating system (5) is located between the bare fiber wire diameter meter (401) and the traction motor (402); the optical fiber prepared by the wire diameter control system (4) enters the coating mold (501), so that the surface of the optical fiber is wrapped by an organic polymer; the coated optical fiber passes through the UV curing device (502), and the coating layer on the surface of the optical fiber is rapidly cured under the irradiation of ultraviolet rays to obtain a finished optical fiber; the integrated control system (3) monitors the diameter of the coated optical fiber through the coated optical fiber wire diameter meter (503) to measure the thickness of the coating layer.

8. A special optical fiber drawing tower according to any one of claims 1 to 7, characterized in that: The wire collecting system (6) comprises a guide wheel (601), a traction wheel (602) and a wire collecting drum (603); In the wire collection system (6), the guide wheel (601), the traction wheel (602) and the wire collection drum (603) are arranged in a series structure. The finished optical fiber changes direction through the guide wheel (601), then passes through the traction wheel (602) and is connected to the wire collection drum (603), and the wire collection drum (603) winds the finished optical fiber.

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