| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for controlling the outer diameter of a glass preform and an apparatus for drawing the glass preform which enable the outer diameter of the glass preform to be uniform after being drawn. <P>SOLUTION: In the method for controlling the outer diameter of the glass preform, comprising controlling the outer diameter of the glass preform to be constant after drawing by controlling the feeding speed of the glass preform 10 to be drawn and the taking-up speed of the softened glass preform, the outer diameter D1 of the fed glass preform 10 to be drawn is measured at a prescribed interval, and at the same time, the measured values are successively stored, further the outer diameter D2 of the softened part 23 where the diameter is reduced, of the glass preform 10 is measured, and a control outer diameter setting value D2s of the softened part 23 is calculated from the stored outer diameter D1 of the glass preform 10 before being drawn corresponding to the measured outer diameter D2 of the softened part 23 and a target outer diameter D3s, and thereafter, the feeding speed and the taking-up speed are controlled so that the measured outer diameter D2 of the softened part becomes the control outer diameter setting value D2s. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
