| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass preform and a sintering furnace for manufacturing a glass preform, which avoid an unsintered part and prevent excessive heating of a seed rod, so that drawn elongation can be avoided. <P>SOLUTION: In the sintering furnace 10 for manufacturing the glass preform, a heat shield tool 20 having a lower tool 22 capable of being positioned is directly fixed to a starting seed rod 3 and the lower tool 22 is disposed near the upper tapered part 2 of a glass fine particle deposited body 1. Thereby, since heat shield is achieved so as to avoid transfer of heat from a heater 12 to the starting seed rod 3, drawn elongation of the starting seed rod 3 can be reliably prevented. Since the upper part of the glass fine particle deposited body 1 can be brought close to the heater 12, the region of an unsintered part in the upper end of the glass fine particle deposited body 1 can be made small. Since the lower tool 22 can be positioned in the longitudinal direction of the glass fine particle deposited body 1, positioning of the heat shield plate can be performed for each glass fine particle deposited body 1 without being brought into contact with the glass fine particle deposited body 1. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
