JP6565556B2 - Glass base material lifting device - Google Patents

Description

  The present invention relates to an elevating device for a glass base material.

  In the glass base material manufacturing process, if corrosive gas leaks, the metal parts of the manufacturing equipment are corroded, and the metal dust in the indoor atmosphere increases, and many metal impurities are mixed in the glass base material. There is. Therefore, Patent Document 1 discloses an upper lid structure for preventing a corrosive gas such as a chlorine-based gas or a fluorine-based gas from leaking in a glass base material sintering step.

  Also, when the glass base material manufacturing equipment stops abnormally, during unsteady work accompanying recovery after abnormal stop, etc., or during maintenance maintenance, the glass base material lifting device and gas supply device are individually provided. Since the operation can be performed independently, harmful gas in the core tube may leak to the outside if the operation is performed inappropriately. Therefore, Patent Document 2 discloses a method for detecting leakage of corrosive gas due to erroneous operation even during maintenance by detecting that the upper lid is closed in the sintering furnace by the encoder count number of the lifting device.

JP 2008-105904 A JP 2012-121737 A

  The optical fiber preform manufacturing apparatus described in Patent Document 1 discloses prevention of gas leakage from the core tube. However, if gas leaks, there is a possibility that the drive unit inside the lifting device may corrode. It was. Further, Patent Document 2 discloses a device that prevents corrosive gas from leaking even if the operation method at the time of unsteady operation is wrong. Could deteriorate.

  The present invention prevents the silica fine particles and corrosive gas from entering the inside of the lifting device provided in the glass base material manufacturing apparatus, and causes the failure of the lifting device due to corrosion of the driving mechanism and lifting mechanism of the lifting device. The purpose is to prevent.

The glass base material lifting apparatus of the present invention is
An elevating mechanism for elevating and lowering the glass base material;
A drive mechanism for operating the elevating mechanism;
A partition mechanism for partitioning the internal space of the lifting device including at least the drive mechanism section from the outside;
A pressure maintaining mechanism for maintaining the pressure in the internal space at a higher pressure than the outside.

In addition, the glass base material lifting device of the present invention is
An elevating mechanism for elevating and lowering the glass base material;
A drive mechanism for operating the elevating mechanism;
A partition mechanism that partitions the interior space of the lifting device including the sliding portion of the lifting portion and the drive mechanism portion from the outside.

  According to the present invention, silica fine particles and corrosive gas are prevented from entering the inside of the lifting device provided in the glass base material manufacturing apparatus, and at least the lifting device failure caused by corrosion of the components of the drive mechanism section is prevented. Can be prevented.

It is the schematic of the glass base material manufacturing apparatus containing the raising / lowering apparatus of the glass base material which concerns on this invention. It is the sectional view on the AA line of the raising / lowering apparatus of the glass base material shown in FIG. It is the schematic which shows the modification of the raising / lowering apparatus of the glass base material which concerns on this invention.

<Outline of Embodiment of the Present Invention>
First, an outline of an embodiment of the present invention will be described.
The glass base material lifting apparatus according to the present embodiment is
(1) an elevating mechanism for elevating and lowering the glass base material;
A drive mechanism for operating the elevating mechanism;
A partition mechanism for partitioning the internal space of the lifting device including at least the drive mechanism section from the outside;
A pressure maintaining mechanism for maintaining the pressure in the internal space at a higher pressure than the outside.
According to this configuration, silica fine particles and corrosive gas are prevented from entering the inside of the lifting device provided in the glass base material manufacturing apparatus, and the lifting device is prevented from being damaged due to corrosion of the components of the drive mechanism. be able to.

(2) It is preferable that the sliding part of the raising / lowering mechanism part is accommodated in the internal space.
According to this configuration, it is possible to prevent deterioration and failure of the sliding portion of the lifting mechanism portion.

(3) The partition mechanism is preferably a roll curtain.
According to this configuration, intrusion of gas or the like can be reliably prevented with a simple configuration.

(4) The pressure maintaining mechanism is preferably a fan for sending air into the internal space.
According to this configuration, the air outside the lifting device is continuously sent to the internal space by the fan, so that the pressure in the internal space is increased with respect to the outside, and the intrusion of gas or the like can be prevented more reliably.

(5) It is preferable that the pressure maintaining mechanism is a mechanism for introducing a compressed gas into the internal space.
According to this configuration, by introducing the compressed gas into the internal space, the pressure of the internal space can be increased with respect to the outside, and intrusion of gas or the like can be prevented more reliably.

The glass base material lifting apparatus according to another example of the present embodiment is
(6) an elevating mechanism for elevating the glass base material;
A drive mechanism for operating the elevating mechanism;
A partition mechanism that partitions the interior space of the lifting device including the sliding portion of the lifting portion and the drive mechanism portion from the outside.
According to this configuration, silica fine particles and corrosive gas are prevented from entering the inside of the lifting device provided in the glass base material manufacturing device, and the drive mechanism part of the lifting device and the components of the lifting mechanism part are corroded. It is possible to prevent a failure of the lifting device due to.
In addition, it is preferable that the said partition mechanism as described in (6) is a roll curtain. Thereby, the penetration | invasion of gas etc. can be prevented reliably with a simple structure.

<Details of Embodiment of the Present Invention>
Hereinafter, an example of an embodiment of a glass base material raising / lowering device according to the present invention will be described with reference to the drawings. In each drawing used for the following description, the scale is appropriately changed for convenience of description.

  As a method for producing a glass base material, first, a glass raw material gas such as silicon tetrachloride is supplied to an oxyhydrogen burner to produce silica fine particles and sprayed onto a glass rod in a reaction vessel to produce a glass fine particle deposit. (VAD method and OVD method) are known. After the glass fine particle deposit is manufactured, the glass fine particle deposit is inserted into the furnace core tube in the dehydration and sintering process, and the furnace core tube is filled with a dehydrated gas atmosphere such as chlorine gas to raise the temperature and dehydrate the glass fine particle deposit. After that, the temperature is further increased and sintering is performed.

FIG. 1 is a schematic view of a glass base material manufacturing apparatus including a glass base material lifting apparatus, and FIG. 2 is a cross-sectional view taken along line AA of the glass base material lifting apparatus shown in FIG. In FIG. 2, illustration of a reaction vessel and a cladding burner described later is omitted.
As shown in FIGS. 1 and 2, the glass base material manufacturing apparatus 1 according to this embodiment is for manufacturing a glass base material 6 by depositing silica fine particles around a glass rod 5 by, for example, the OVD method. The glass base material manufacturing apparatus 1 includes a reaction vessel 2, and a glass rod 5 is suspended from above the reaction vessel 2.

A clad burner 3 which is a burner for generating glass fine particles is disposed in the reaction vessel 2. The cladding burner 3 is supplied with a raw material gas and a flame forming gas by a gas supply device (not shown). The cladding burner 3 is charged with SiCl ₄ as a source gas, H ₂ or O ₂ as a flame forming gas, and N ₂ as a burner seal gas. In the oxyhydrogen flame formed by the cladding burner 3, silica fine particles are generated by a flame hydrolysis reaction. The generated silica fine particles are deposited around the glass rod 5 to form a glass fine particle deposit, thereby producing a glass base material 6 having a predetermined outer diameter. In the manufacturing process of the glass base material 6, corrosive gas such as HCl gas as a by-product and silica fine particles not deposited around the glass rod 5 are sent from the reaction vessel 2 to an abatement apparatus (not shown). Processed.

Above the reaction vessel 2, an elevating device 10 for the glass base material 6 (glass rod 5) is arranged. The lifting device 10 includes a housing 11, a drive mechanism unit 12, and a lifting mechanism unit 20.
The drive mechanism unit 12 is disposed in the internal space S of the lifting device 10 and includes a motor 13 and a gear box 14 in which a reduction gear and a clutch (not shown) are accommodated. A pulley 15 is fixed to the output shaft of the motor 13. A pulley 16 is also fixed to the gear box 14. A timing belt 17 is wound between a pulley 15 fixed to the motor 13 and a pulley 16 fixed to the gear box 14.

  The elevating mechanism 20 includes an elevating chuck 21 that protrudes laterally from the elevating device 10. The upper end of the glass rod 5 is held by the lifting chuck 21. The elevating mechanism unit 20 includes a base plate 22 that partitions the drive mechanism unit 12 and the elevating mechanism unit 20 in the internal space S of the elevating device 10. The base plate 22 is provided with a pair of slide rails 23. The lifting chuck 21 is supported by a pair of slide rails 23 so as to be movable in the vertical direction. In addition, in the top view of FIG. 2, a ball screw 24 extending in the vertical direction is provided at the center of the lifting chuck 21. A pulley 25 is disposed below the ball screw 24. Power is transmitted from the gear box 14 to the pulley 25 via the rotating shaft 19 around which the timing belt 18 is wound. A brake 26 is provided at the lower end of the ball screw 24. When the ball screw 24 is rotated forward and backward by driving the motor 13 of the drive mechanism unit 12, the lifting chuck 21 supported by the slide rail 23 is lifted and lowered. The glass rod 5 whose upper end is gripped by the lifting chuck 21 is lifted and rotated by the lifting device 10. The slide rail 23, the ball screw 24, the portion of the elevating chuck 21 that is supported by the slide rail 23 and the portion that is penetrated by the ball screw 24 are defined as “sliding portions”.

  As shown in FIG. 1, a roll curtain 27 (an example of a partition mechanism) is provided outside the ball screw 24 provided in the lifting chuck 21. The roll curtains 27 are respectively disposed above and below the elevating chuck 21 and are fixed with bolts or the like so as to maintain hermeticity with respect to the elevating chuck 21. Rollers 28 are respectively provided on the upper surface and the lower surface of the housing 11, and the roll curtain 27 is wound and released as the rollers 28 rotate as the elevating chuck 21 moves up and down.

  As shown in FIG. 2, an opening 11 </ b> B is provided in the front surface portion 11 </ b> A of the housing 11, and the lifting chuck 21 protrudes outward from the opening 11 </ b> B, and the opening / lowering of the opening 11 </ b> B. A roll curtain 27 is provided so as to close an area other than the chuck 21. With such a configuration, the internal space S of the housing 11 in which the drive mechanism unit 12 and the lifting mechanism unit 20 are arranged can be partitioned so as not to be released to the outside of the housing 11. Note that the space between the roll curtain 27 and the front surface portion 11A of the housing 11 is not completely sealed, and a slight gap may be generated when the roll curtain 27 is wound and released.

In the housing 11, a fan 30 (an example of a pressure maintaining mechanism) is installed on the back surface opposite to the lifting chuck 21. In this example, the upper and lower two fans 30 are arranged on the back surface of the housing 11, but the number and arrangement of the fans 30 are not limited to this. Air is sent from the outside into the internal space S of the housing 11 by the fan 30. The air sent into the internal space S by the fan 30 is released to the outside through a gap generated between the roll curtain 27 and the front surface portion 11 </ b> A of the housing 11. As a result, the internal space S of the housing 11 is maintained in a state where the pressure is higher than the outside, and corrosive gas and silica fine particles are internally contained from the gap generated between the roll curtain 27 and the front surface portion 11A of the housing 11. Intrusion into the space S can be prevented.
In order to prevent the corrosive gas and silica fine particles generated from the reaction vessel 2 and the glass fine particle deposit (glass base material 6) from being taken into the elevating device 10 by the fan 30, the fan 30 is used in the reaction vessel 2. It is preferable to attach to the back surface part or side surface part of the housing | casing 11 away from.

  As described above, in the glass base material manufacturing process, silica fine particles are generated and deposited on the glass rod in the reaction vessel, and corrosive gas such as HCl gas and silica fine particles not deposited are removed from the reaction vessel. Although it is sent to a harmful apparatus for processing, a corrosive gas or silica fine particles may leak from the upper part of the reaction vessel or the like due to pressure fluctuation in the reaction vessel.

  Therefore, in the lifting device 10 of the present embodiment, the interior space S of the casing 11 in which the lifting mechanism unit 20 for lifting the glass base material 6 and the drive mechanism unit 12 for operating the lifting mechanism unit 20 are accommodated is externally provided. A roll curtain 27 for partitioning and a fan 30 for maintaining the pressure in the internal space S at a higher pressure than the outside, and the corrosive gas and silica particles leaked from the reaction vessel 2 are removed from the casing 11 of the lifting device 10. To prevent intrusion. Thereby, it is possible to prevent corrosive gas and silica fine particles from coming into contact with the motor 13 and the pulleys 15 and 16 of the drive mechanism unit 12, the slide rail 23 of the elevating mechanism unit 20, the ball screw 24, and the like. As a result, corrosion and failure of the lifting device 10 can be avoided, and the glass base material 6 that is stable over a long period can be manufactured.

In particular, the slide rail 23 and the ball screw 24 of the elevating mechanism 20 have a sliding portion for moving the elevating chuck 21 up and down. If the surface of the sliding portion rusts or silica particles adhere, The moving part deteriorates or wears down, leading to reduced accuracy and failure.
On the other hand, in the present embodiment, the sliding portion (the slide rail 23, the ball screw 24, and the slide rail 23 of the lifting chuck 21) of the lifting mechanism portion 20 is placed in the internal space S partitioned from the outside by the roll curtain 27. The supported part and the part penetrated by the ball screw 24) are arranged. Therefore, deterioration of a sliding part can be prevented and the precision of the raising / lowering operation | movement of the glass rod 5 can be maintained.

  In addition, although the structure of this embodiment was demonstrated to the example of the raising / lowering apparatus 10 of the glass base material manufacturing apparatus 1 in a glass particulate deposition process, this implementation is carried out to the glass base material raising / lowering apparatus in the glass base material dehydration sintering process, for example. A configuration of forms can be applied. Even in the dehydration and sintering configuration, a small amount of dehydrated gas in the core tube may leak from the upper portion of the core tube, and even in such a case, the configuration of the present embodiment can be applied to prevent corrosion and failure of the glass base material lifting device. Can do.

Furthermore, the structure which concerns on the raising / lowering apparatus of this embodiment is applicable also to the vertical flame polisher etc. which are used at the process of flame-polishing the surface of a glass base material. The flame polishing step is a step of heating the glass base material with an oxyhydrogen burner to convert SiO ₂ on the surface of the glass base material into SiO (gas), thereby smoothing the irregularities on the surface of the glass base material and cleaning / smoothing. It is. In the flame polishing step, silica particles are generated and released to the outside when SiO ₂ on the surface of the glass base material is vaporized. Therefore, it is very useful to employ the configuration of the present embodiment in a glass base material lifting device used in a vertical flame polisher to prevent silica fine particles from entering the lifting device.

(Example)
In the vertical flame polisher used in the flame polishing process of the glass base material, the drive mechanism part and the lift mechanism part of the glass base material lifting device are partitioned by a roll curtain, and a fan that blows outside air into the partitioned interior is installed. In such a vertical flame polisher, the surface of the glass base material was continuously subjected to flame polishing while the rotating portion and the sliding portion of the drive mechanism portion were periodically greased. As a result, even if 100 glass base materials were continuously flame-polished, no failure occurred in the drive mechanism or the like.

(Comparative example)
On the other hand, using a vertical flame polisher in which the drive mechanism unit and the lifting mechanism unit are not partitioned from the outside air, the grease of the rotating part of the driving mechanism unit and the sliding part of the lifting mechanism unit is periodically periodically as in the above embodiment. While performing up, flame polishing of the surface of the glass base material was continuously performed. As a result, at the stage where 30 glass base materials were flame-polished continuously, the vibration of the glass base material increased and it was impossible to polish at a desired thickness. As a cause, it is thought that the vibration increased due to the rust of the slide rail and the ball screw due to the intrusion of the silica fine particles into the drive mechanism and the lifting mechanism and the adhesion of the silica fine particles.

  By installing a roll curtain and a fan in the glass base material lifting device according to the above-mentioned examples and comparative examples, it is possible to prevent silica fine particles and corrosive gas from entering the inside of the lifting device, and the rotating part of the drive mechanism unit. It has been confirmed that failure of the lifting device due to corrosion or deterioration of the sliding portion of the lifting mechanism and the like can be prevented.

  While the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. In addition, the number, position, shape, and the like of the constituent members described above are not limited to the above-described embodiments, and can be changed to a number, position, shape, and the like that are suitable for carrying out the present invention.

In the above embodiment, the fan 30 is installed as a pressure maintaining mechanism that maintains the pressure in the internal space S of the housing 11 higher than the pressure outside the housing 11, but is not limited to this example. .
As in the lifting device 110 shown in FIG. 3, the piping 40 is connected to the housing 111 instead of the fan 30, and compressed gas such as compressed air is introduced into the internal space S from the outside of the housing 111 through the piping 40. Also good. The compressed gas introduced into the casing 111 through the pipe 40 is discharged to the outside from the casing 111 (for example, from a gap generated between the roll curtain 27 and the casing 111), so that the inside of the lifting device 110 The pressure in the space S can be maintained higher than the outside. In addition, it is preferable to provide an air filter in the inside of the pipe 40 and remove dust from the compressed gas passing through the pipe 40 to obtain clean air.

  Further, instead of the roll curtain 27, for example, bellows type covers may be installed on the upper and lower sides of the elevating chuck 21, and the bellows type covers may be used as a partitioning mechanism with the outside.

  In the above embodiment, the roll curtain 27 is provided above and below the lifting chuck 21 outside the ball screw 24 so as to partition the drive mechanism 12 and the lifting mechanism 20 from the outside. Not limited. The base plate 22 that divides the drive mechanism unit 12 and the lifting mechanism unit 20 may be used as a partitioning mechanism with the outside, so that at least corrosive gas and silica fine particles can be prevented from entering the drive mechanism unit 12.

  Furthermore, in the said embodiment, although the fan 30 is installed in the housing | casing 11 of the raising / lowering apparatus 10, and the pressure of the internal space S of the raising / lowering apparatus 10 is made higher than the exterior, it is not restricted to this example. Instead of providing the fan 30, only the roll curtain 27 may be installed to prevent the invasion of corrosive gas and silica fine particles.

1: Glass base material manufacturing apparatus 2: Reaction vessel 3: Clad burner 5: Glass rod 6: Glass base material 10, 110: Lifting device 11, 111: Case 12: Drive mechanism 13: Motor 14: Gear box 20 : Lift mechanism 21: Lift chuck 22: Base plate 23: Slide rail 24: Ball screw 27: Roll curtain 30: Fan 40: Piping

Claims (6)

A lifting device that lifts and lowers the glass base material in the reaction vessel,
An elevating mechanism for elevating and lowering the glass base material;
A drive mechanism for operating the elevating mechanism;
A partitioning mechanism for partitioning an internal space of the lifting device including at least the drive mechanism part from the outside, the partitioning mechanism being spaced apart from the reaction vessel;
A pressure maintaining mechanism for maintaining the pressure in the internal space at a higher pressure than the outside;
With
The glass base material elevating device, wherein the partition mechanism prevents corrosive gas or silica fine particles leaked from the reaction vessel from entering the elevating device. A lifting device that lifts and lowers the glass base material in the furnace core tube,
An elevating mechanism for elevating and lowering the glass base material;
A drive mechanism for operating the elevating mechanism;
A partitioning mechanism for partitioning an internal space of the lifting device including at least the drive mechanism part from the outside, the partitioning mechanism being spaced apart from the reaction vessel;
A pressure maintaining mechanism for maintaining the pressure in the internal space at a higher pressure than the outside;
With
The glass base material elevating device, wherein the partition mechanism prevents dehydrated gas leaked from the furnace core tube from entering the elevating device.   The glass base material lifting / lowering apparatus according to claim 1 or 2, wherein a sliding portion of the lifting mechanism is accommodated in the internal space.   The glass base material lifting device according to any one of claims 1 to 3, wherein the partition mechanism is a roll curtain.   The said pressure maintenance mechanism is a raising / lowering apparatus of the glass base material as described in any one of Claims 1-4 which is a fan for sending air into the said interior space. The said pressure maintenance mechanism is a raising / lowering apparatus of the glass base material as described in any one of Claims 1-4 which is a mechanism which introduces compressed gas in the said internal space .

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