A furnace mouth sealing mechanism and a mother bar drawing device

Abstract

The utility model relates to a kind of furnace mouth sealing mechanism and mother bar stretching equipment, and the moving plate and organ case are lifted by telescopic drive source control, realize that sealing height is infinitely adjustable, can be adapted to different length mother bar, avoid mechanical interference, realize the flexible production of '' one mechanism adapts multiple specifications ''.The structure has good sealing, can sustain low oxygen environment in furnace, effectively protect graphite piece, prolong its service life, reduce consumable cost and maintenance time.Simultaneously, stable furnace environment also improves the uniformity of mother bar heating, help to improve the consistency of optical fiber geometric size and optical performance, improve product quality and yield.

Description

Technical Field

[0001] This utility model relates to the technical field of optical fiber preform production equipment, and in particular to a furnace mouth sealing mechanism and a mother rod stretching device. Background Technology

[0002] In the manufacturing process of optical fiber preforms, stretching is a critical step, and the core equipment is a high-temperature furnace composed of graphite heaters, large insulating tanks, and other graphite components. The equipment powers the graphite heaters via copper electrodes, generating high temperatures, which are maintained by the graphite insulation components. To ensure long-term safe and stable operation, an external circulating water cooling system is installed, and nitrogen gas is introduced at the upper and lower furnace openings to create a protective atmosphere, preventing oxidation of the graphite components at high temperatures.

[0003] However, existing stretching equipment has a serious drawback: poor overall sealing, especially at the upper furnace opening. This directly leads to the following chain of problems: Existing furnace opening seals are mostly fixed structures, which cannot accommodate mother rods of different lengths. The sealing cap at the furnace opening can mechanically interfere with the auxiliary rod, preventing the furnace opening from closing. This allows a large amount of external air (rich in oxygen) to be drawn into the furnace, while a significant amount of the internal nitrogen protective atmosphere escapes, causing turbulent airflow inside the equipment and making it impossible to effectively control the oxygen concentration at a low level. Under continuous high temperatures, oxygen will undergo a violent oxidation reaction with the graphite components, significantly shortening their lifespan and requiring frequent replacements, greatly increasing production costs. Furthermore, unstable airflow and temperature fields directly affect the uniformity of heating of the mother rod, negatively impacting the stretching quality and consistency of the optical fiber.

[0004] Therefore, there is an urgent need for an upper furnace opening mechanism that can dynamically adapt to different lengths of mother rods and achieve efficient sealing, so as to fundamentally protect graphite parts, save production costs, and improve the process level. Utility Model Content

[0005] Therefore, the technical problem to be solved by this utility model is to overcome the fact that the existing master bar stretching equipment cannot adapt to master bars of different lengths, which makes it impossible to effectively seal the upper furnace opening, resulting in a significant reduction in the service life of graphite parts in the furnace, frequent replacement, and a substantial increase in production costs. Furthermore, the unstable airflow and temperature field in the furnace will affect the final quality of the stretched mandrel.

[0006] To solve the above-mentioned technical problems, this utility model provides a furnace opening sealing mechanism for sealing the upper furnace opening of a vertically installed mother bar stretching device and improving the device's versatility for mother bars of different lengths. The mother bar extends into the furnace opening of the stretching device after being hooked by an auxiliary rod. A telescopic drive source is vertically disposed on one side of the master bar stretching device, with the output end of the telescopic drive source facing upward. A movable plate, which is horizontally connected to the output end of the telescopic drive source, and a through hole is vertically opened on the movable plate; A quartz plate, wherein a central through hole is coaxially formed on the quartz plate and is sleeved on the auxiliary rod through the central through hole, the quartz plate is used to cover the through hole and seal it after the main rod is inserted into the furnace opening; The bellows cover has one end connected to the bottom of the quartz plate and coaxial with the central through hole, and the other end connected to the upper furnace opening of the mother rod stretching equipment.

[0007] In one embodiment of this utility model, the output end of the telescopic drive source is provided with a connector, the connector including two L-shaped connecting arms, the two connecting arms are symmetrically arranged and parallel to each other, one end of the two connecting arms is connected to the moving plate, and the other end is vertically connected to a connecting seat, the output end of the telescopic drive source is connected to the connecting seat.

[0008] In one embodiment of this utility model, a proximity switch is provided on the connector, and the detection end of the proximity switch faces upward.

[0009] In one embodiment of this utility model, a controller is included, which is connected to the proximity switch and the telescopic drive source respectively.

[0010] In one embodiment of the present invention, the top of the movable plate is provided with an annular protrusion coaxial with the through hole, and at least one annular groove is coaxially formed on the top of the annular protrusion, and an annular first sealing element is embedded in the annular groove.

[0011] In one embodiment of this utility model, an annular second sealing element is coaxially disposed on the inner wall of the central through hole.

[0012] In one embodiment of this utility model, the accordion cover is made of a combination of high silica cloth and fiberglass aluminum foil cloth.

[0013] In one embodiment of this utility model, a fixing plate is further included, which is disposed on one side of the mother bar stretching device, and the telescopic drive source is mounted on the fixing plate.

[0014] In one embodiment of this utility model, the telescopic drive source is a servo electric cylinder.

[0015] A mother bar stretching device includes a furnace mouth sealing mechanism as described in any of the above.

[0016] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art: This utility model discloses a furnace mouth sealing mechanism and a mother rod stretching device. By using a telescopic drive source to move the moving plate and bellows cover, the sealing height is infinitely adjustable, dynamically adapting to mother rods of different lengths. This completely avoids mechanical interference caused by changes in the length of the mother rod or auxiliary rod, achieving flexible production with "one mechanism adapting to multiple specifications," greatly improving the equipment's versatility and production scheduling flexibility. The excellent sealing performance keeps the oxygen concentration inside the furnace at an extremely low level, fundamentally inhibiting the oxidation reaction of graphite parts at high temperatures, significantly extending the service life of graphite parts, reducing the replacement frequency due to oxidation loss, and directly lowering the core consumable costs and maintenance downtime of the equipment. It also ensures the stability of the thermal and airflow fields inside the furnace, making the mother rod more evenly heated during stretching, significantly improving the consistency of the optical fiber's geometric dimensions and optical performance, directly improving the stretching quality and yield of the product. Attached Figure Description

[0017] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. Figure 1 This is a schematic diagram of the overall structure of the furnace mouth sealing mechanism according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the moving plate of the furnace mouth sealing mechanism in a preferred embodiment of the present invention.

[0018] Explanation of the reference numerals in the instruction manual's attached drawings: 1. Telescopic drive source; 2. Moving plate; 21. Annular protrusion; 3. Quartz plate; 4. Bellows cover; 5. Connector; 51. Connecting arm; 52. Connecting seat; 6. Proximity switch; 7. Fixing plate. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0020] Example 1, refer to Figure 1 and Figure 2 As shown, this utility model discloses a furnace opening sealing mechanism for sealing the upper furnace opening of a vertically installed mother bar stretching device and improving the device's versatility for mother bars of different lengths. The mother bar extends into the furnace opening of the stretching device after being hooked by an auxiliary rod. Telescopic drive source 1 is vertically installed on one side of the mother bar stretching device, with the output end of the telescopic drive source 1 facing upwards. The movable plate 2 is horizontally connected to the output end of the telescopic drive source 1, and a through hole is vertically opened on the movable plate 2. Quartz plate 3, with a central through hole coaxially opened on the quartz plate 3 and sleeved on the auxiliary rod through the central through hole, is used to cover the through hole and seal it after the mother rod is inserted into the furnace mouth. The bellows cover 4 has one end connected to the bottom of the quartz plate 3 and coaxial with the central through hole, and the other end connected to the upper furnace opening of the mother rod stretching equipment.

[0021] This utility model provides a furnace opening sealing mechanism that uses a telescopic drive source 1 to drive a moving plate 2 and a bellows cover 4 to rise and fall, achieving infinitely adjustable sealing height. This mechanism can dynamically adapt to master rods of different lengths, completely avoiding mechanical interference problems caused by changes in the length of the master rod or auxiliary rod. Whether the master rod is of standard or special length, it ensures complete closure of the upper furnace opening, achieving flexible production with "one mechanism adapting to multiple specifications," greatly improving the equipment's versatility and production scheduling flexibility. The excellent sealing performance keeps the oxygen concentration inside the furnace at an extremely low level, fundamentally inhibiting the oxidation reaction of expensive graphite components such as graphite heaters and insulation tanks at high temperatures. This significantly extends the service life of graphite components, reduces the replacement frequency due to oxidation loss, directly lowers the core consumable costs and maintenance downtime, and is of great significance for saving production costs. Simultaneously, this mechanism ensures the stability of the thermal and airflow fields inside the furnace, making the master rod more evenly heated during the stretching process, significantly improving the consistency of the geometric dimensions and optical properties of the stretched mandrel, directly improving the stretching quality and yield of the product.

[0022] Furthermore, the output end of the telescopic drive source 1 is provided with a connector 5, which includes two L-shaped connecting arms 51. The two connecting arms 51 are symmetrically arranged and parallel to each other, and one end of the two connecting arms 51 is connected to the moving plate 2, while the other end is vertically connected to a connecting seat 52. The output end of the telescopic drive source 1 is connected to the connecting seat 52. Specifically, the telescopic drive source 1 (such as a servo electric cylinder) typically performs linear motion in the vertical direction. The connector 5 reliably transmits the vertical thrust of the drive source to the horizontal moving plate 2, ensuring that the moving plate 2 can smoothly rise and fall vertically. Through the two symmetrically distributed connecting arms 51, the concentrated force of the drive source is evenly distributed to two points on the moving plate 2, avoiding plate jamming or uneven force that may be caused by single-point drive.

[0023] Furthermore, a proximity switch 6 is provided on the connector 52, with the detection end of the proximity switch facing upwards. The proximity switch 6 is used to detect whether the moving plate 2 or the connector 5 has reached a preset limit position, thereby realizing position feedback and ensuring the safe operation of the equipment.

[0024] Furthermore, a controller is included, which is connected to the proximity switch 6 and the telescopic drive source 1 respectively. The controller enables automatic control of each component, improving the automation level and efficiency of the equipment.

[0025] Furthermore, the top of the movable plate 2 is provided with an annular protrusion 21 coaxial with the through hole. At least one annular groove is coaxially formed on the top of the annular protrusion 21, and an annular first sealing element is embedded in the annular groove. Specifically, compared with a complete planar contact, the design of the annular protrusion 21 makes its top contact area with the quartz plate 3 smaller, thereby increasing the pressure acting on the first sealing element. This concentrated high pressure can ensure that the first sealing element undergoes sufficient elastic or plastic deformation, tightly filling the microscopic unevenness between the contact surface with the quartz plate 3, thereby forming a sealing interface with excellent airtightness.

[0026] Furthermore, a second annular seal is coaxially disposed on the inner wall of the central through hole. Specifically, when the quartz plate 3 covers the through hole of the movable plate 2, the first seal can fit tightly against the bottom of the quartz plate 3, forming an effective sealing barrier to prevent external air from entering the furnace. The second seal is also made of a material with good sealing performance. It can tightly wrap around the auxiliary rod A, further enhancing the sealing effect and preventing gas from leaking from the gap between the auxiliary rod and the central through hole, ensuring that the nitrogen protective atmosphere inside the furnace is not destroyed.

[0027] Furthermore, the bellows cover 4 is woven from a combination of high-silica fabric and fiberglass aluminum foil. This material combination gives the bellows cover 4 excellent high-temperature resistance, good flexibility, and tear resistance. The high-silica fabric has extremely high high-temperature resistance and can withstand high-temperature environments without melting or decomposing; the fiberglass aluminum foil not only has good thermal insulation properties but also enhances the strength and abrasion resistance of the bellows cover 4.

[0028] Furthermore, it also includes a fixing plate 7, which is disposed on one side of the mother bar stretching device B, and the telescopic drive source 1 is mounted on the fixing plate 7. Specifically, the fixing plate 7 provides stable support and fixing points for the telescopic drive source 1, ensuring that it will not shift or shake during operation. At the same time, the fixing plate 7 also serves to connect and integrate other components, enabling the entire sealing mechanism to be tightly integrated with the mother bar stretching device, working together to complete the stretching and sealing work of the mother bar.

[0029] Furthermore, the telescopic drive source 1 adopts a servo electric cylinder. The servo electric cylinder has the advantages of high precision, high speed, high thrust and good controllability, and can accurately control the lifting and lowering of the moving plate 2 to adapt to the mother rod of different lengths.

[0030] Working principle: In the initial state or when replacing the mother rod, the telescopic drive source 1 is in the retracted state, driving the moving plate 2 to descend. At this time, the bellows cover 4 connected between the moving plate 2 and the furnace opening on the equipment is in the compressed state, making room for the auxiliary rod and its suspended mother rod, allowing it to enter the furnace without obstruction; Once the mother rod is positioned inside the furnace, the telescopic drive source 1 is activated, driving the moving plate 2 to move upwards. The rise of the moving plate 2 causes the bellows cover 4 to extend and lengthen upwards, forming a flexible sealed cavity that can completely cover the part of the mother rod extending out of the furnace opening. Finally, the annular protrusion 21 on the top of the moving plate 2 and its first sealing element fit tightly against the quartz plate 3 sleeved on the auxiliary rod, completing the sealing of the through hole of the moving plate 2.

[0031] At this point, the upper furnace opening is effectively sealed, and nitrogen gas can be introduced into the furnace to form a protective atmosphere. The entire process adapts to mother rods of different lengths, achieving dynamic and effective sealing.

[0032] Example 2: This utility model also discloses a mother rod stretching device, including the furnace mouth sealing mechanism as in Example 1.

[0033] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A furnace opening sealing mechanism for sealing the upper furnace opening of a vertically installed mother bar stretching device and improving the device's versatility for mother bars of different lengths, wherein, The mother bar, after being attached by an auxiliary bar, extends into the furnace opening of the stretching equipment. Its characteristic is that it includes: A telescopic drive source is vertically disposed on one side of the mother bar stretching device, with the output end of the telescopic drive source facing upward. A movable plate, which is horizontally connected to the output end of the telescopic drive source, and a through hole is vertically opened on the movable plate; A quartz plate, wherein a central through hole is coaxially formed on the quartz plate and is sleeved on the auxiliary rod through the central through hole, the quartz plate is used to cover the through hole and seal it after the main rod is inserted into the furnace opening; The bellows cover has one end connected to the bottom of the quartz plate and coaxial with the central through hole, and the other end connected to the upper furnace opening of the mother rod stretching equipment.

2. The furnace mouth sealing mechanism according to claim 1, characterized in that: The output end of the telescopic drive source is provided with a connector, which includes two L-shaped connecting arms. The two connecting arms are symmetrically arranged and parallel to each other. One end of the two connecting arms is connected to the moving plate, and the other end is vertically connected to a connecting seat. The output end of the telescopic drive source is connected to the connecting seat.

3. The furnace mouth sealing mechanism according to claim 2, characterized in that: A proximity switch is provided on the connector, and the detection end of the proximity switch faces upward.

4. The furnace mouth sealing mechanism according to claim 3, characterized in that: It includes a controller, which is connected to the proximity switch and the telescopic drive source respectively.

5. The furnace mouth sealing mechanism according to claim 1, characterized in that: The top of the movable plate is provided with an annular protrusion coaxial with the through hole, and at least one annular groove is coaxially formed on the top of the annular protrusion, and an annular first sealing element is embedded in the annular groove.

6. The furnace mouth sealing mechanism according to claim 1, characterized in that: A second annular seal is coaxially disposed on the inner wall of the central through hole.

7. The furnace mouth sealing mechanism according to claim 1, characterized in that: The accordion cover is made of a combination of high-silica cloth and fiberglass aluminum foil cloth.

8. The furnace mouth sealing mechanism according to claim 1, characterized in that: It also includes a fixing plate, which is disposed on one side of the mother bar stretching device, and the telescopic drive source is mounted on the fixing plate.

9. The furnace mouth sealing mechanism according to claim 1, characterized in that: The telescopic drive source is a servo electric cylinder.

10. A mother bar stretching device, characterized in that: Includes the furnace opening sealing mechanism as described in any one of claims 1-9.

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