JP6288056B2 - Glass base material manufacturing apparatus and manufacturing method - Google Patents

Description

  The present invention relates to a glass base material manufacturing apparatus and manufacturing method.

  Patent Document 1 discloses an optical fiber preform manufacturing apparatus that deposits glass fine particles on the outer periphery of a starting material while pulling up while rotating the starting material. The manufacturing apparatus includes a rotatable jig that is provided on a support base that is mounted so as to be movable in the vertical direction and supports the lower end portion of the starting material. By pulling, a constant force can always be applied to the lower end of the starting material to suppress the deviation between the rotation axis and the starting material central axis.

JP-A-7-109142

  In the optical fiber preform manufacturing apparatus described in Patent Document 1, when the starting material is moved at a high speed, the jig on the support base does not catch up with the high-speed movement of the starting material and cannot follow. For this reason, when it is necessary to move the starting material up and down at high speed, such as in the OVD method, it is not possible to sufficiently suppress the occurrence of deviation between the rotating shaft and the starting material central axis (so-called starting material swinging). If the glass fine particles are deposited in a state where the rotation axis and the starting material central axis are deviated from each other, uneven thickness is generated in the case of a glass pipe, and the core eccentricity characteristic is deteriorated in the case of an optical fiber preform.

  An object of this invention is to provide the manufacturing apparatus and manufacturing method of a glass base material which can suppress the whirling of the glass rod at the time of high-speed movement.

The glass base material manufacturing apparatus of the present invention comprises:
The upper end portion of the glass rod is gripped by the upper end gripping portion, the lower end portion of the glass rod is supported by the lower end support portion, and the glass particles are formed on the outer periphery of the glass rod while reciprocating up and down while rotating the glass rod. An apparatus for producing a glass base material to be deposited,
The lower end support portion includes an elevating mechanism that moves up and down independently of the upper end gripping portion, and an elastic member provided at a contact portion with the glass rod,
A determination unit configured to determine that a deformation amount of the elastic member due to the pressing of the contact portion against the glass rod has reached a predetermined amount;

Moreover, the manufacturing method of the glass base material of the present invention includes
A glass base material manufacturing method for depositing glass particles on the outer periphery of the glass rod while reciprocating up and down while rotating the glass rod,
Grasping the upper end of the glass rod by the upper end gripping part,
Raising the lower end support part supporting the lower end part of the glass rod independently of the upper end grip part;
The lower end support part is brought into contact with the glass rod at the contact part,
When the elastic member provided in the contact portion is deformed by a predetermined amount due to the contact of the contact portion with the glass rod, the lower end support portion is stopped rising;
Thereafter, the glass rod is reciprocated up and down while synchronizing the upper end gripping portion and the lower end support portion.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing apparatus and manufacturing method of a glass base material which can suppress the whirling of the glass rod at the time of high-speed movement can be provided.

It is the schematic of the manufacturing apparatus of the glass base material which concerns on this invention. It is the schematic which shows the initial position setting of the glass rod by the manufacturing apparatus shown in FIG. It is a flowchart which shows the manufacturing method of the glass base material which concerns on this invention. It is a graph which shows the weight measurement result of the glass base material manufactured with the manufacturing apparatus which concerns on this invention, and the weight measurement result of the glass base material manufactured with the manufacturing apparatus which concerns on a prior art example.

<Outline of Embodiment of the Present Invention>
First, an outline of an embodiment of the present invention will be described.
The manufacturing apparatus of the glass base material concerning this embodiment is as follows.
(1) The upper end portion of the glass rod is gripped by the upper end gripping portion, and the lower end portion of the glass rod is supported by the lower end support portion. An apparatus for producing a glass base material on which fine glass particles are deposited,
The lower end support portion includes an elevating mechanism that moves up and down independently of the upper end gripping portion, and an elastic member provided at a contact portion with the glass rod,
A determination unit configured to determine that a deformation amount of the elastic member due to the pressing of the contact portion against the glass rod has reached a predetermined amount;
According to this configuration, the glass rod can be supported with an appropriate pushing strength while the supporting device follows the high-speed movement of the glass rod. Therefore, it is possible to provide a glass base material manufacturing apparatus capable of suppressing the whirling of the glass rod during high-speed movement.

(2) It is preferable that the said upper end holding part is connected with the weight measuring instrument which measures the weight of the said glass rod, and the deposition amount of the said glass particulates deposited on the said glass rod.
According to this configuration, it is possible to improve the accuracy of the weight measurement of the glass fine particles when the glass fine particles are deposited on the glass rod.

Moreover, the manufacturing method of the glass base material concerning this embodiment is as follows.
(3) A glass base material manufacturing method in which glass fine particles are deposited on the outer periphery of the glass rod while reciprocating up and down while rotating the glass rod,
Grasping the upper end of the glass rod by the upper end gripping part,
Raising the lower end support part supporting the lower end part of the glass rod independently of the upper end grip part;
The lower end support part is brought into contact with the glass rod at the contact part,
When the elastic member provided in the contact portion is deformed by a predetermined amount due to the contact of the contact portion with the glass rod, the lower end support portion is stopped rising;
Thereafter, the glass rod is reciprocated up and down while synchronizing the upper end gripping portion and the lower end support portion.
According to this structure, the manufacturing method of the glass base material which can suppress the whirling of the glass rod at the time of high-speed movement can be provided.

(4) It is preferable to measure the weight of the glass rod and the amount of the glass fine particles deposited on the glass rod by a weight measuring device provided on the upper end gripping portion.
According to this configuration, it is possible to improve the accuracy of the weight measurement of the glass fine particles when the glass fine particles are deposited on the glass rod.

(5) The predetermined deformation amount of the elastic member is preferably 0.1 kg or more and less than or equal to the weight of the glass rod in terms of the pushing force of the glass rod by the contact portion.
From the viewpoint of suppressing the whirling of the glass base material and improving the accuracy of measuring the amount of deposited glass fine particles, it is preferable that the pushing force of the glass rod by the contact portion is in the above range.

<Details of Embodiment of the Present Invention>
Hereinafter, an example of an embodiment of a manufacturing apparatus and a manufacturing method of a glass base material concerning the present invention is explained with reference to drawings.

As shown in FIG. 1, the glass base material manufacturing apparatus 10 of this embodiment deposits glass fine particles around the glass rod 20 by, for example, the OVD method.
The production apparatus 10 includes a reaction vessel 11, and a glass rod 20 is suspended from above the reaction vessel 11. An elevating and rotating device 12 is disposed above the reaction vessel 11. It arrange | positions so that the upper end holding part 13 may protrude toward the side from the raising / lowering rotation apparatus 12. As shown in FIG. The upper end portion of the glass rod 20 is held by the upper end holding portion 13.

  The glass rod 20 whose upper end is gripped by the upper end gripping portion 13 of the lifting / lowering rotating device 12 is moved up and down and rotated by the lifting / lowering rotating device 12. In the lifting / lowering rotating device 12, the lifting / lowering speed and the rotating speed are controlled by the control device 14 so that the outer diameter of the glass particulate deposit 21 deposited on the outer periphery of the glass rod 20 is uniform. A weight measuring device 15 is disposed in the vicinity of the upper end gripping portion 13. The weight measuring device 15 measures the weight of the glass rod 20 and the deposition amount of the glass particulate deposit 21 deposited on the outer periphery of the glass rod 20.

  A clad burner 16 that is a burner for generating glass fine particles is disposed inside the reaction vessel 11. The cladding burner 16 is a multi-tube burner such as an octuplic tube. A raw material gas and a flame forming gas are supplied to the cladding burner 16 by a gas supply device 17. The gas supply amount of the gas supply device 17 is controlled by the control device 14.

The cladding burner 16 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 16, glass fine particles are generated by a flame hydrolysis reaction. The generated glass fine particles are deposited around the glass rod 20 to form a glass fine particle deposit 21, thereby producing a glass base material 22 having a predetermined outer diameter.

  A support device 30 (an example of a lower end support portion) is disposed below the reaction vessel 11, and the lower end portion of the glass rod 20 protruding downward from the inside of the reaction vessel 11 is supported by the support device 30. . The support device 30 includes a contact portion 31 that contacts the lower end portion of the glass rod 20, and an elevating mechanism 33 that is disposed below the contact portion 31. The contact portion 31 supports the glass rod 20 by being in contact with the lower end portion of the glass rod 20 in order to suppress swinging of the glass rod 20. A support bar 32 extends downward from the contact portion 31, and a spring 34 is disposed around the support bar 32. Further, the upper end of the spring 34 is fixed in contact with the lower part of the contact part 31, and the lower end of the spring 34 is fixed in contact with the upper part of the lifting mechanism 33.

  The raising / lowering mechanism 33 is controlled by the control device 14 so that the raising / lowering speed of the raising / lowering mechanism 33 can be raised or lowered independently or in synchronization with the upper end gripping part 13 that grips the upper end part of the glass rod 20. The lower end portion of the support bar 32 is inserted into the elevating mechanism 33. A sensor 35 (an example of a determination unit) is disposed on the side of the lifting mechanism 33. As shown in FIG. 2, when the elevating mechanism 33 rises and approaches the abutting portion 31, the lower end portion of the support bar 32 is moved downward inside the elevating mechanism 33, and the sensor 35 has its measurement point S. It is possible to detect the position of the lower end portion of the support bar 32 inserted into the lifting mechanism 33. When the lower end portion of the support bar 32 reaches the measurement point S of the sensor 35, the sensor 35 determines that the spring 34 has reached a predetermined deformation amount (contraction amount), and the elevation of the elevating mechanism 33 is stopped. Thereby, since the spring 34 maintains a predetermined amount of contraction, the pushing-up force of the glass rod 20 by the contact portion 31 is maintained at a constant strength.

  Note that the predetermined deformation amount (shrinkage amount) of the spring 34 by bringing the elevating mechanism 33 closer to the contact portion 31 is 0.1 kg or more in terms of the pushing force of the glass rod 20 by the contact portion 31. It is preferable that the weight is not more than the weight of the glass rod (for example, about 4.5 kg). When the pushing-up force of the glass rod 20 by the contact part 31 is smaller than 0.1 kg, it is difficult to obtain the effect of suppressing the whirling of the glass base material 22. On the other hand, if the pushing force of the glass rod 20 by the contact portion 31 is larger than the weight of the glass rod 20 gripped by the upper end gripping portion 13, the gripping portion of the glass rod 20 floats or comes off from the upper end gripping portion 13. As a result, an error occurs in the measurement of the weight of the glass rod and the amount of deposited glass particles by the weight measuring device 15. Therefore, it is preferable that the pushing-up force of the glass rod 20 by the contact portion 31 is in the above range.

Next, the manufacturing method of the glass base material 22 is demonstrated below. FIG. 3 is a flowchart showing a method for manufacturing the glass base material 22.
First, as shown in FIG. 1, the upper end portion of the glass rod 20 is grasped by the upper end grasping portion 13 and suspended in the reaction container 11 (step S1). Next, the upper end gripping portion 13 (elevating and rotating device 12) and / or the supporting device 30 supporting the lower end portion of the glass rod 20 are moved up and down independently of each other, and the abutting portion 31 is brought into contact with the lower end portion of the glass rod 20 (Step S2).

  Next, as shown in FIG. 2, the elevating mechanism 33 is raised in a state where the contact portion 31 is in contact with the lower end portion of the glass rod 20 (step S <b> 3). Thereby, the contact part 31 is pressed against the glass rod 20, and the lower end part of the support bar 32 is moved downward in the raising / lowering mechanism 33 (step S4). In this way, the spring 34 disposed on the outer periphery of the support bar 32 is (compressed) deformed.

  Subsequently, the detection process by the sensor 35 is started (step S5). While the lower end of the support bar 32 is not detected by the sensor 35 (NO in step S5), the elevating mechanism 33 continues to rise. When the sensor 35 detects the lower end of the support bar 32 (Yes in step S5), that is, when the sensor 35 determines that the spring 34 has reached a predetermined deformation amount, the lifting of the elevating mechanism 33 is stopped. (Step S6). When the lifting of the elevating mechanism 33 is stopped, the spring 34 is fixed so as to maintain a predetermined amount of contraction, whereby the support process of the glass rod 20 by the support device 30 is completed.

  Thereafter, the upper gripping portion 13 and the support device 30 are moved by the control device 14 while the amount of contraction of the spring 34 is maintained, that is, the pushing-up force of the glass rod 20 by the contact portion 31 is maintained at a constant strength. The glass rod 20 is reciprocated up and down while being synchronized (step S7). And glass fine particles are deposited on the outer periphery of the glass rod 20, and the glass base material 22 is produced (step S8). At this time, the weight measuring device 15 arranged in the vicinity of the upper end gripping part 13 measures the weight of the glass rod 20 and the amount of the glass particulate deposit 21 deposited on the outer periphery of the glass rod 20 to obtain a predetermined weight (deposition). When the amount reaches, the deposition of glass particles on the outer periphery of the glass rod 20 is terminated. Thus, the glass base material 22 is produced.

  As described above, in the present embodiment, the support device 30 includes the lifting mechanism 33 that moves up and down independently of the upper end gripping portion 13 and the spring 34 provided in the contact portion 31 with the glass rod 20. And a sensor 35 for determining that the amount of deformation of the spring 34 due to the pressing of the contact portion 31 against the glass rod 20 has reached a predetermined amount. According to this configuration, even when the glass rod 20 moves at a high speed, the support device 30 can be made to follow the moving speed of the glass rod 20 and the spring 34 can be moved at a position where the spring 34 is contracted by a predetermined amount. By performing the positioning, the glass rod 20 can be supported by the support device 30 with a constant pushing strength. Therefore, even when the glass rod 20 moves at a high speed, the swinging of the glass rod 20 can be sufficiently suppressed. By suppressing the whirling of the glass rod 20, it is possible to obtain a glass pipe with less uneven thickness in the case of a glass pipe, and to obtain an optical fiber preform with good core eccentricity characteristics in the case of an optical fiber preform. be able to.

  In the present embodiment, the upper end gripping portion 13 is connected to a weight measuring device 15 that measures the weight of the glass rod 20 and the amount of glass particles deposited on the glass rod 20. Since the swinging of the glass rod 20 can be sufficiently suppressed by the support device 30, it is possible to improve the accuracy of the weight measurement of the glass fine particles by the weight measuring device 15 when the glass fine particles are deposited on the glass rod 20.

  In the present embodiment, the sensor 35 determines that the amount of deformation of the spring 34 is 0.1 kg or more and less than the weight of the glass rod 20 in terms of the pushing force of the glass rod 20 by the contact portion 31. When this happens, the raising and lowering of the elevating mechanism 33 is stopped so that the spring 34 maintains a predetermined contraction amount. By making the pushing-up force of the glass rod 20 by the contact part 31 within the above range, it is more preferable from the viewpoint of suppressing the swinging of the glass base material 22 and improving the accuracy of measuring the amount of deposited glass particles.

(Example)
FIG. 4 is a graph showing a result of weight measurement of a glass base material manufactured by the manufacturing apparatus according to the present embodiment and a result of weight measurement of a glass base material manufactured by the manufacturing apparatus according to the conventional example. In FIG. 4, the result of having measured the weight of the glass base material 22 produced with the manufacturing apparatus 10 provided with the support apparatus 30 which concerns on this embodiment as Example 1 (Example) is shown along time passage. . On the other hand, as Example 2 (conventional example), unlike the support device 30 according to the present embodiment, the glass when the lower end portion of the glass rod is supported by a jig that does not have a mechanism for adjusting the push-up force of the glass rod. The weight measurement result of the base material is shown. In Example 1 and Example 2, the weight of the glass rod held by the glass base material manufacturing apparatus (the upper end holding part) is 5 kg, and in Example 1, the pushing force of the glass rod by the support device is 4.2 kg. is there.
As a result, as shown in FIG. 4, it was confirmed that Example 1 can significantly suppress the variation in the weight (deposition amount) of the glass fine particles as compared with Example 2. The instantaneous large fluctuations that appear periodically are due to the turning up and down of the glass rod.
Further, the swing of the glass rod when the glass fine particles are deposited by the glass base material manufacturing apparatus of Example 1 is 0.5 mm, and the glass rod swings when the glass fine particles are deposited by the glass base material manufacturing apparatus of Example 2 The circumference was 3.0 mm. Thus, it was confirmed that the whirling of the glass rod can be significantly suppressed by using the glass base material manufacturing apparatus including the support device according to the present embodiment.

  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.

  The glass base material manufacturing apparatus 10 according to the embodiment described above is applied to a full-length traverse method in which a single cladding burner 16 is provided and the glass base material 22 is formed over the entire length by the single cladding burner 16. However, the present invention is not limited to this example. For example, in the partial traverse method in which a plurality of burners are arranged vertically in the reaction vessel 11 and the glass base material is partially formed by each burner, the glass base material manufacturing apparatus 10 according to the above embodiment is applied. Also good.

  Moreover, in the said embodiment, after the support process of the glass rod 20 by the support apparatus 30 is complete | finished, the upper end holding part 13 and the support apparatus 30 are synchronized, and the glass rod 20 is reciprocated up and down, and glass particle | grains are made. Although deposition is performed, a plurality of sensors 35 are arranged on the side of the lifting mechanism 33 of the support device 30 to detect a change in the lower end portion of the support rod 32, and the amount of contraction of the spring 34 is reduced even during the glass particle deposition process. You may make it adjust suitably. Thereby, the glass rod 20 can be always supported with a constant pushing force even during the glass fine particle deposition step, and the whirling of the glass rod 20 can be more sufficiently suppressed.

DESCRIPTION OF SYMBOLS 10: Manufacturing apparatus of glass base material 11: Reaction container 12: Elevating rotation apparatus 13: Upper end holding part 14: Control apparatus 15: Weight measuring device 16: Burner for clad 17: Gas supply apparatus 20: Glass rod 21: Glass particulate deposition Body 22: Glass base material 30: Support device (an example of a lower end support part)
31: Contact part 32: Support rod 33: Elevating mechanism 34: Spring (an example of an elastic member)
35: Sensor (an example of a discrimination unit)

Claims (5)

The upper end portion of the glass rod is gripped by the upper end gripping portion, the lower end portion of the glass rod is supported by the lower end support portion, and the glass particles are formed on the outer periphery of the glass rod while reciprocating up and down while rotating the glass rod. An apparatus for producing a glass base material to be deposited,
The lower end support portion includes an elevating mechanism that moves up and down independently of the upper end gripping portion, and a spring provided at a contact portion with the glass rod,
The spring is disposed on the outer periphery of the support bar so that a support bar extending downward from the contact portion is inserted into the spring.
An apparatus for manufacturing a glass base material, comprising: a determination unit configured to determine that the amount of deformation of the spring due to pressing of the contact portion against the glass rod has reached a predetermined amount.   2. The glass base material manufacturing apparatus according to claim 1, wherein the upper end gripping unit is connected to a weight measuring device that measures a weight of the glass rod and a deposition amount of the glass fine particles deposited on the glass rod. A glass base material manufacturing method for depositing glass particles on the outer periphery of the glass rod while reciprocating up and down while rotating the glass rod,
Grasping the upper end of the glass rod by the upper end gripping part,
Raising the lower end support part supporting the lower end part of the glass rod independently of the upper end grip part;
The lower end support part is brought into contact with the glass rod at the contact part,
Arranged on the outer periphery of the support rod so that the support rod provided in the contact portion by the contact of the contact portion with the glass rod and extending downward from the contact portion is inserted inside the support rod. When the spring that has been deformed by a predetermined amount, the lower end support part stops rising,
Thereafter, the glass rod is reciprocated up and down while synchronizing the upper end gripping part and the lower end support part.   The method for producing a glass base material according to claim 3, wherein the weight of the glass rod and the deposition amount of the glass fine particles deposited on the glass rod are measured by a weight measuring device provided at the upper end gripping part. The said predetermined deformation amount of the said spring is 0.1 kg or more converted into the pushing-up force of the said glass rod by the said contact part, and is below the weight of a glass rod. Manufacturing method of glass base material.

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