JPH0741331A - Method and device for production optical-fiber preform - Google Patents

Abstract

PURPOSE:To provide an optical-fiber preform without changing the chucking of a starting rod when the rod is transferred to a dehydrating and sintering furnace from the deposition chamber. CONSTITUTION:An even number of deposition chambers D1 and sintering furnaces S1 are isometrically and alternately provided around the center axis YY, chucks 4 for the respective deposition chambers D1 and sintering furnace S1 are rotated back and forth around a rotary column 1 to an angle of 360 deg./(total number of furnaces and chambers), and an optical-fiber preform 7 suspended from each chuck 4 is positioned alternately in the chamber D1 and in the furnace S1 without being chucked by another chuck.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing an optical fiber preform, and more particularly, to an optical fiber which does not re-grip a starting rod when being transferred from a deposition chamber to a dehydration sintering furnace. The present invention relates to a method and an apparatus for manufacturing a fiber preform.

[0002]

2. Description of the Related Art In the case of manufacturing an optical fiber preform by the VAD method, first, a starting rod is grasped and suspended by a chuck of a deposition chamber, and a required soot is adhered and deposited on the starting rod in the deposition chamber. When forming the optical fiber preform and then transferring to the dehydration sintering process,
The step of removing the starting rod from the chuck of the deposition chamber and replacing it with the chuck in the sintering furnace is taken.

[0003]

When the chucking of the starting rod is changed, the optical fiber preform is accidentally dropped and damaged, or the optical fiber preform is damaged by the vibration at the time of changing the grip. was there.

[0004]

The present invention has been made to solve this problem, and the means of the invention according to claim 1 for solving the problem is to provide a starting rod in a deposition chamber. In the method for producing an optical fiber preform, in which a required soot is deposited and grown on the optical fiber preform to produce an optical fiber preform, and thereafter, the optical fiber preform is dehydrated and sintered in a sintering furnace. In the method for manufacturing an optical fiber preform, the suspension support of the starting rod is carried out with the chuck held in the deposition chamber and the chuck is not gripped again when it is transferred to a sintering furnace.

Further, the solution means of the invention of claim 2 is that the rotating column is provided so as to be rotatable around the central axis, and an even number of equiangularly arranged around the rotating column is vertically moved up and down. A free horizontal arm, a chuck that is rotatably provided with respect to the horizontal arm and should hold a starting rod, and is arranged below the horizontal arm in a conformal and angular direction alternately around the central axis. The manufacturing apparatus for an optical fiber preform has a deposition chamber and a sintering furnace, which are provided in the same number as the horizontal arms in total, and a drive means for rotating the rotation column around the central axis.

According to the invention of claim 3, there is provided a horizontal arm which is equiangularly provided around the fixed column and which is vertically movable by screwing on a feed screw shaft extending in the vertical direction. A chuck rotatably provided for gripping the starting rod, a guide shaft extending vertically in parallel with the feed screw shaft and rotatable about this axis, and the guide shaft around the feed screw shaft. An optical fiber mother having a link plate and a driving means to be rotated, and a deposition chamber and a sintering furnace, which are alternately arranged equiangularly around the central axis of each of the feed screw shafts at a position below the horizontal arm. This is a material manufacturing device.

[0007]

With respect to the deposition chamber and the sintering furnace, which are equiangularly and alternately provided around the central axis, the rotating column is provided with the same number of chucks as the total number of furnaces and chambers. Alternatively, by reciprocating the horizontal arm about the central axis by an angle of 360 ° / (total number of furnaces and chambers), the optical fiber preforms suspended and supported by the chucks are deposited. It can be located alternately in the chamber and in the sintering furnace.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to an embodiment of the present invention will be described with reference to FIGS. A substantially columnar rotating column 1 is provided so as to be rotatable around a vertically extending central axis YY. The cross section of the rotating column 1 is, for example, square as shown in the figure, and horizontal arms 2 extending horizontally outward in the radial direction are provided on the four side surfaces corresponding to the respective sides, respectively.
It can be lifted up and down.

A chuck 4 rotated by a drive motor 6 is provided on the horizontal arm 2, and a starting rod 5 is vertically held by each chuck 4. As is well known, the required soot is deposited and deposited on the starting rod 5 so as to form the optical fiber preform 7.

Below the horizontal arm 2, an even number (a total of four in this embodiment) of deposition chambers D1 are positioned conformally around a central axis YY and are rotatable about this axis YY. , D2 and sintering furnaces S1, S2 are alternately arranged in the angular direction. Speaking of the installation position, the center of each of the furnaces D and S is approximately the center of the chuck 4 described above.
It is made to match the position of.

The structure in the deposition chamber D is similar to that of a normal one, and for example, a burner 11 for forming soot is used.
Is provided. Further, the inside of the sintering furnace S is similar to the ordinary one, and the heating means 10 is appropriately arranged around the heating cylinder arranged inside the heat insulating layer. Reference numeral 8 indicates a common lid shared by both the deposition chamber D1 and the sintering furnace S1, and is attached and detached by a lid lifting cylinder 9.

The rotating column (1) is rotatably supported by a column rotating shaft 12 extending along the central axis YY.
The fluid pressure cylinder 13 provided on the lower side makes a reciprocating rotation of 90 degrees in the case of this embodiment.

Finally, how to use the apparatus of this embodiment will be described. It will be easy to understand since it will be obvious from the above-mentioned configuration. The starting rods 5 are attached to every other chuck 4.
The corresponding horizontal arm 4 is lowered and these starting rods 5 are first placed in the deposition chambers D1, D2.

When the soot is deposited and the optical fiber preform 7 having a desired size is formed, the horizontal arm 2 is pulled up. Then, the driving means 13 is operated to rotate the rotating column 1 and position the optical fiber preform 7 generated in the original deposition chamber D1 so as to correspond to the sintering furnace S1. After that, the horizontal arm 2 is lowered so that the optical fiber preform 7 is now in the sintering furnace S1, and the dehydration sintering process is performed.

Next, another embodiment of the apparatus of the present invention will be described with reference to FIGS. 3 and 4. In this embodiment, the column is provided as a fixed column 1A that does not rotate, and each horizontal arm 2 rotates about the feed screw shaft 3. A guide shaft 15 for guiding the vertical screw feed of the horizontal arm 2 is provided in parallel with the feed screw shaft 3, and is connected to the feed screw shaft 3 by the upper and lower link plates 14. The link plate 14 and the feed screw shaft 3 are rotatable with respect to each other.

As clearly shown in FIG. 4, a long groove is formed in the link plate 16, and the guide shaft 15 is sandwiched in the long groove.
Engage with. The link plate 16 feeds the guide shaft 15 to the feed screw shaft 3 by driving means 17 such as a fluid pressure cylinder.
Rotate around the central axis of. That is, by rotating the guide shaft 15 around the feed screw shaft 3, the horizontal arm 2 can be rotated between two positions as shown by the solid line and the broken line in FIG.

[0017]

According to the present invention, the rotating column or each horizontal arm is rotated back and forth about the central axis by an angle of 360 degrees / (total number of furnaces and chambers), thereby making this rotation. Fiber optic preforms suspended in a number of chucks equal to the total number of furnaces and chambers, which are equiangularly arranged with an angular spacing equal to the moving angle, are alternately located in the deposition chamber and the sintering furnace. Therefore, there is an advantage that the deposition and dehydration-sintering processes can be efficiently performed without re-grabbing the starting rod, which has a high risk of falling damage.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an apparatus according to an embodiment of the present invention, which is a sectional view taken along the line I-I of FIG.

FIG. 2 is a plan view of the device of FIG. 1 seen from above.

FIG. 3 is a side sectional view showing an apparatus according to another embodiment of the present invention.

FIG. 4 is a partial plan view showing a rotating mechanism of a horizontal arm.

[Explanation of symbols]

 1 Rotating Column 2 Horizontal Arm 3 Feed Screw Shaft 4 Chuck 5 Starting Rod 6 Driving Motor 7 Optical Fiber Base Material 8 Common Lid 9 Lid Lifting Cylinder 10 Heating Means 11 Burner 12 Column Rotating Shafts 13, 17 Driving Means 14, 16 Link Plate 15 Guide axis D Deposition chamber S Sintering furnace YY Center axis

Claims (3)

[Claims] 1. A required soot is deposited and grown on a starting rod (5) in a deposition chamber (D) to produce an optical fiber preform (7), and then this optical fiber preform (7). In the method for producing an optical fiber preform in which sintering is performed in a sintering furnace (S), the starting rod (5) is suspended when being transferred from the deposition chamber (D) to the sintering furnace (S). Support the deposition chamber (D)
The method for producing an optical fiber preform, wherein the chuck gripping is performed as it is and the chuck gripping is not changed. 2. A turning column (1) rotatably provided around a central axis (YY), and an even number of equiangularly provided around the turning column (1) so as to be vertically movable. Horizontal arm (2), a chuck (4) that is rotatably provided with respect to the horizontal arm (2) and should hold a starting rod (5), and the central axis line is located below the horizontal arm (2). (YY) are arranged equiangularly and angularly alternately, and a total of the same number of horizontal chambers (2) as the deposition chambers (D) and sintering furnaces (S) and the rotating column are provided. An apparatus for manufacturing an optical fiber preform, comprising: a drive means (13) for rotating (1) around the central axis (YY). 3. A horizontal arm (2) which is equiangularly provided around the fixed column (1A) and is vertically movable by being screwed onto a feed screw shaft (3) extending in the vertical direction, and the horizontal arm (2). A chuck (4) which is rotatably provided with respect to (2) and should grip a starting rod (5), and a guide shaft (which extends vertically parallel to the feed screw shaft (3) and can be rotated around this axis. 1
5), a link plate (16) for rotating the guide shaft (15) around the feed screw shaft (3) and a driving means (17), and the feeds below the horizontal arm (2). An apparatus for producing an optical fiber preform having a deposition chamber (D) and a sintering furnace (S), which are alternately arranged conformally around a central axis of a screw shaft (3).