JP2008088037A - Method of manufacturing fine-glass-particle deposited body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a high grade fine-glass-particle deposited body by accurately measuring the deposited quantity of fine glass particles during the manufacture. <P>SOLUTION: The method of manufacturing the fine-glass-particle deposited body is provided by which a glass rod 11 is vertically held while gripping the upper end of a glass rod 11 and vertically moved while being rotated and a plurality of deposited layers of the fine glass particles are deposited on the circumference of the glass rod 11 using a burner. The method is characterized in that the glass rod 11 and a gripping part 12 are hung on a weight measuring part to measure the weight of the hung part, a plurality of feed conditions of gas to the burner 26 is changed based on the change in the measured weight, a whirling vibration suppressing tool 30 arranged in the vicinity of the lower end of the glass rod 11 is brought into contact with the whirling vibration of the lower end of the glass rod 11 to suppress the whirling vibration and the whirling vibration suppressing tool 30 is moved with the vertical movement of the glass rod 11 while vertically moving the weight measuring part 13 by a frame 21. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method for producing a glass fine particle deposit by depositing glass fine particles generated by a burner around a rod and forming a plurality of glass fine particle deposition layers.

  In general, as a method for producing a glass particulate deposit, the glass particulate deposit is grown in the axial direction by depositing glass particulates on the outer periphery thereof while rotating the rod supporting the upper end in the axial direction while rotating the rod. Examples thereof include a VAD method and an OVD method of growing in the radial direction.

When the glass fine particle deposit is manufactured by the above manufacturing method, if the rod becomes long, the swing around the rod rotates and the amount of glass fine particles deposited on the rod may be non-uniform. For this reason, the apparatus for producing a glass particulate deposit body is provided with a rod vibration isolator that holds and stabilizes not only the upper end but also the lower end in order to prevent the rod from swinging and prevent non-circularity and uneven thickness. Are known (for example, see Patent Document 1).
This glass rod vibration isolator is provided with a vibration isolating cap formed from a metal such as aluminum that contacts the lower end of the glass rod that moves in the axial direction.

JP 2004-10377 A

  By the way, when manufacturing a glass particle deposit by the above manufacturing method, a deposition amount measuring device (weight measuring device) is installed in the gripping portion of the rod in order to confirm the amount of glass particle deposition. In some cases, a glass particulate deposit is produced while monitoring the change as the amount of deposited glass particulates.

  However, since the vibration isolator as described above has a structure in which a dish-shaped or pipe-shaped jig is pressed against the tip of the rod to suppress the vibration, the value measured by the deposition amount measuring apparatus is It will be in the state where the force of pressing is added. In addition, if the rod is moved up and down, the force acting on the rod from the vibration isolator fluctuates during ascent and descent, so the measured value of the accumulated amount becomes unstable, and the measured value for each movement of the rod is reliable. Will be low. Therefore, it is difficult to accurately adjust the deposition amount according to the measurement value of the deposition amount.

  The present invention provides a method for producing a glass particulate deposit capable of producing a high-quality glass particulate deposit by accurately measuring the amount of deposited glass particulate during production and appropriately adjusting the deposition amount. It is intended to provide.

  The method for producing a glass particulate deposit according to the present invention that can solve the above-mentioned problems is a burner that generates glass particulates by holding the upper end of a rod vertically while holding it vertically and moving the rod up and down while rotating the rod. Is a method for producing a glass particulate deposit body in which a plurality of glass particulate deposition layers are formed around the rod, wherein the rod and the gripping portion for gripping the upper end of the rod are suspended from a weight measuring portion, and the weight of the suspended portion And changing a gas supply condition to the burner for generating the glass fine particles based on the measured change in weight, and arranging a whirling suppression jig near the lower end of the rod, When the whirling restraining jig contacts the whirling at the lower end of the rod, the whirling is restrained and the weight measuring unit is moved up and down by the rod moving table. To, it is characterized by moving together the whirling suppressed jig moving up and down the rod.

Further, it is preferable that the whirling suppression jig does not follow the movement of the glass rod when the rod moves upward from a predetermined position.
At that time, the whirling restraining jig is pushed up to the predetermined position by the push-up mechanism that pushes up the whirling restraining jig or the jig fixing portion that fixes the whirling restraining jig. It is preferable that the fixture fixing portion abuts on the rod moving table and moves together with the rod moving table.

  According to the method for producing a glass particulate deposit of the present invention, the whirling suppression jig is in contact with the whirling of the lower end of the rod, and is further moved in accordance with the vertical movement of the rod. Therefore, without changing the measurement value of the weight measurement unit with the whirling suppression jig, the amount of glass fine particles deposited is accurately measured during production, and the gas is supplied to the burner based on the measured weight change. By appropriately adjusting the deposition amount by changing the conditions, a high-quality glass particulate deposit can be produced.

Hereinafter, an example of an embodiment of a method for producing a glass fine particle deposit according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a manufacturing apparatus for carrying out the method for manufacturing a glass fine particle deposit according to the present embodiment.

  As shown in FIG. 1, the glass particle deposit manufacturing apparatus 10 holds the glass rod 11 vertically while holding the upper end of the glass rod 11 with the holding portion 12, and rotates the glass rod 11 with the holding portion 12. The weight measuring unit 13 for suspending the unit 12 is moved up and down by a frame (rod moving table) 21 of the rod moving device 20 to move the glass rod 11 up and down, and around the glass rod 11 by a burner 26 that generates glass fine particles. A glass fine particle deposit G is produced by forming a plurality of glass fine particle deposition layers. In the glass particle deposit manufacturing apparatus 10, the whirling suppression jig 30 is arranged in the vicinity of the lower end of the glass rod 11, and the whirling suppression jig 30 comes into contact with the whirling suppression at the lower end of the glass rod 11. The surroundings are suppressed, and the whirling suppression jig 30 is moved in accordance with the vertical movement of the glass rod 11.

  The grip portion 12 that grips the upper end of the glass rod 11 is connected to a rotating shaft 16 of the motor 14, and rotates the glass rod 11 by rotating by the rotational drive of the motor 14. The motor 14 is installed on the upper surface of a support 15 having a short cylindrical shape with an open bottom, and the gripping portion 12 is attached to the inside of the support 15 via a bearing 18. The support 15 is disposed on the weight measuring unit 13 installed on the frame 21 of the rod moving device 20, and the weight of the motor 14, the bearing 18, the grip 12, the glass rod 11, and the glass particulate deposit G together with the support 15. Are suspended by the weight measuring unit 13, and the weights of these suspended portions are measured by the weight measuring unit 13 and can be monitored by the control unit 24. The weight measuring unit 13 may be, for example, load cells arranged at three locations along the circumferential direction of the support 15.

  The rod moving device 20 has a weight measuring unit 13 installed on the upper part of a frame 21 as a rod moving table, and has a structure for moving the gripping unit 12 and the like supported via the weight measuring unit 13 up and down. A ball screw 22 and a rail 23 provided in the vertical direction are attached to the frame 21. That is, the frame 21 is moved up and down in the axial direction of the ball screw 22 by the rotation of the ball screw 22 while being guided by the rail 23.

  As described above, the upper end of the glass rod 11 is gripped by the grip portion 12, and the glass rod 11 is moved up and down by the rod moving device 20. On the other hand, in the vicinity of the lower end of the glass rod 11, a whirling suppression jig 30 that suppresses whirling while being in contact with the whirling of the lower end of the glass rod 11 is disposed. As shown in FIG. 2, the whirling suppression jig 30 is formed with a cylindrical hole 35 on the inside, and when the glass rod 11 swings, the glass rod 11 comes into contact with the outer periphery of the glass rod 11. It is designed to suppress the whirling around. The inner diameter of the hole 35 is set to a size having a slight clearance with respect to the inserted glass rod 11 so as to prevent the glass rod 11 from being swung while allowing the glass rod 11 to be inserted. The depth of the hole 35 allows the glass rod 11 to move up and down slightly with respect to the whirling suppression jig 30 and moves the glass rod 11 in the axial direction when the glass rod 11 is attached to and detached from the grip portion 12. The length is movable as much as possible. The material of the whirling suppression jig 30 is preferably aluminum, carbon, or ceramic in consideration of heat resistance and corrosion resistance when depositing glass particles.

  Further, the whirling suppression jig 30 is supported by a jig fixing portion 31 disposed below the rod moving device 20. The jig fixing portion 31 is urged upward by a push-up mechanism 34 while being guided by a rail 33 provided in a vertical direction. Further, the jig fixing portion 31 is in contact with the lower end of the frame 21 of the rod moving device 20 at the contact portion 32, and becomes the upper limit of the stroke that the push-up mechanism 34 pushes up by the action of the push-up biasing force of the push-up mechanism 34. Below a predetermined position, it moves up and down together with the frame 21 while being in contact with the frame 21.

  That is, a predetermined position that is the upper limit for the whirling suppression jig 30 to rise with the frame 21 is determined, and the rod moving device 20 is further lifted from the state in which the whirling suppression jig 30 is in the predetermined position. The glass rod 11 can be detached from the whirling suppression jig 30, and the glass rod 11 can be easily attached to and detached from the grip portion 12.

  The predetermined position of the whirling suppression jig 30 is set to a position above the vertical movement range when the glass particles are deposited on the glass rod 11, and the glass particle deposit G is formed. In this case, the whirling suppression jig 30 always moves together with the glass rod 11. The push-up mechanism 34 may be an air cylinder or a coil spring.

  The apparatus 10 for producing a glass particulate deposit body provided with the above-described whirling suppression jig 30 includes a burner 26 for producing glass particulates fixed to the glass rod 11, and is produced by the burner 26. The glass particulates are deposited on the outer peripheral surface of the glass rod 11 that moves up and down while rotating, forming a plurality of deposited layers, and the glass particulate deposit G grows.

The burner 26 has a port for ejecting a glass raw material gas containing silicon tetrachloride (SiCl ₄ ), a port for ejecting oxygen (O ₂ ) as an auxiliary combustion gas, and hydrogen (H ₂ ) as a combustion support gas. And a port for jetting, generating an oxyhydrogen flame with the jetted oxygen and hydrogen, and jetting a glass raw material gas into the oxyhydrogen flame, thereby producing silica (SiO ₂ ) by a hydrolysis reaction, whereby glass fine particles are produced. Generate.

  The plurality of gases supplied to the burner 26 are respectively adjusted to a desired flow rate and supplied from the gas supply unit 25. The gas supply unit 25 changes the supply amount of each gas according to a command from the control unit 24.

  In the method for producing a glass fine particle deposit according to the present embodiment, the supply conditions (supply amount and ratio) of the gas supplied to the burner 26 are changed according to the glass fine particle deposition amount. As the gas for changing the supply conditions, one or more kinds of silicon tetrachloride, oxygen, hydrogen, and the like can be selected as appropriate. Since the accumulation amount of the glass fine particles corresponds to the increase amount of the value measured by the weight measuring unit 13, for example, the accumulation amount of the glass fine particles while the glass rod 11 is reciprocated once up and down is determined by the weight measuring unit 13. The control unit 24 calculates and monitors from the measured value, and issues a command related to the gas supply condition from the control unit 24 to the gas supply unit 25 so as to correct the deviation of the measured value with respect to the preset target value.

  At this time, the measured value of the weight measuring unit 13 tends to be larger when the glass rod 11 is raised than when the glass rod 11 is lowered due to the influence of the acceleration of gravity and the moving speed of the glass rod 11. May be based on the average value of the measured values during the period in which the glass rod 11 reciprocates up and down once.

  When the glass rod 11 moves up and down, the whirling suppression jig 30 slidably contacts when the lower end of the glass rod 11 swings to suppress the whirling, and the glass particles are uniformly deposited in the circumferential direction of the glass rod 11. Like to do. The whirling suppression jig 30 moves up and down together with the glass rod 11 because it moves in a state where the jig fixing portion 31 is in contact with the rod moving device 20. No vertical force acts between the restraining jig 30. Therefore, the whirling suppression jig 30 does not fluctuate the measurement value of the weight measuring unit 13 and can accurately measure the deposition amount of the glass fine particles. Therefore, since accurate gas supply control based on accurate measurement of the deposition amount can be performed, the deposition amount of each round trip of the glass rod 11 can be adjusted promptly in response to the deposition failure of the glass fine particles. The glass particulate deposit G can be grown.

In the above embodiment, the rod on which the glass particles are deposited is a glass rod, but may be a carbon rod or a ceramic rod.
The push-up mechanism 34 is configured to push up the whirling suppression jig 30 by pushing up the jig fixing portion 31 that supports the whirling suppression jig 30. It may be pushed up.
The shape of the whirling suppression jig 30 is not limited to the shape shown in FIG. 2, and may be any shape that contacts the whirling near the lower end of the glass rod 11 and does not push up the glass rod 11.

  Further, if the frame 21 that is the rod moving base and the swing-out restraining jig 30 are integrated, and the swing-out restraining jig 30 has a halved structure that can be opened and closed appropriately, the push-up mechanism 34 is not used. Good.

It is a schematic block diagram which shows an example of the manufacturing apparatus which enforces the manufacturing method of the glass fine particle deposit body concerning this invention. It is sectional drawing of the whirling suppression jig | tool shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Glass fine particle manufacturing apparatus 11 Glass rod 12 Grasping part 13 Weight measuring part 20 Rod moving device 21 Frame (rod moving stand)
24 Control Unit 25 Gas Supply Unit 26 Burner 30 Swing Suppression Jig 34 Push-up Mechanism

Claims (3)

A glass particulate deposit body in which the upper end of the rod is held vertically and the rod is moved up and down while rotating, and a plurality of glass particulate deposition layers are formed around the rod by a burner that generates glass particulates. A manufacturing method of
Suspend the grip part that grips the rod and its upper end on a weight measurement part, measure the weight of the suspended part,
Changing the gas supply conditions to the burner to produce the glass particulates based on the measured change in weight;
A whirling suppression jig is disposed near the lower end of the rod, and the whirling suppression jig is in contact with the whirling lower end of the rod to suppress whirling,
A method for producing a glass particulate deposit, wherein the weight measuring unit is moved up and down by a rod moving table, and the whirling suppression jig is moved in accordance with the vertical movement of the rod.   2. The method for producing a glass particulate deposit according to claim 1, wherein the whirling suppression jig does not follow the movement of the glass rod when the rod moves upward from a predetermined position.   By the push-up mechanism that pushes up the swing-around suppression jig or the jig fixing portion that fixes the swing-out suppression jig, the swing-out suppression jig is moved up to the predetermined position until the predetermined position. 3. The method for producing a glass particle deposit according to claim 2, wherein the abutment is in contact with the rod moving table and moves together with the rod moving table.

Images