| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for drawing a glass base material, enabling to lower the total height of the drawing device by disposing a glass base material- cooling mechanism between a heating oven for thermally softening the glass base material and a take-off mechanism. SOLUTION: A glass base material 1 charged into a device for drawing the glass base material is fed into a heating oven 3 with a feeding mechanism 7, and subsequently thermally softened. A cooling gas 42 comprising air or an inert gas, such as He or N2 , containing 20-80% of fog droplets and having high cooling efficiency is flown in a cylindrical member 41 disposed around a formed glass rod and constituting a cooling mechanism e.g. at a flow rate of 20-50 m<3> /min in a case of the N2 to cool the glass rod passing through the center of the cylinder at 600-800 deg.C or lower. The cooling gas 42 may be flown not only in the hollow cylinder but also in the inner part 43 of the cylinder 41, namely in a space between the cylinder and the glass base material. The cooled glass rod 2 is draw and taken up as the product glass rod on a take-off mechanism 6 disposed at a place apart from the heating oven 3 by a distance of 800-1,500 mm. |
