| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost method for drawing a glass rod by a glass lathe. SOLUTION: This method comprises having a means for measuring the glass diameter of a tapered part of a drawn body and heating and drawing the glass rod in a furnace while controlling a chuck speed so as to counteract deviation from the set value of the glass diameter of the tapered part. In this case, when the finished diameter of the drawn body is deviated from the set value, the glass rod is drawn while correcting the set value of the glass diameter of the tapered part. The correction of the set value of the glass diameter is carried out by estimating the finished diameter of the drawn body from an average value for a fixed time of difference between a set value V1 of a chuck speed when the travel speed of chucks for griping the upper and the lower ends of the glass body, respectively is controlled for a fixed time and a chuck speed V2 after the control or by estimating the finished diameter of the drawn body from an average value for a fixed time of difference between a set value R1 of the glass diameter of the tapered part and a measured value R2 of the glass diameter of the tapered time so as to correct the set value R1 . |
