| 摘要 |
PURPOSE:To execute hot drawing of glass with high precision of the outside diameter by measuring the outside diameter of the glass previously to the hot drawing and controlling the moving velocity of a drawing mathine, heating device, etc. basing on the measured value. CONSTITUTION:A glass bar 1 is set across both chucks 4A, 4B, and revolved in the direction expressed by the arrow mark R. A heating device 5 is moved by a motor 8 and a feed shaft 9 in the direction of an arrow mark X1. A column 3B is moved by amotor 6 and a feed shaft 7 in the direction of an arrow mark X2; thus, hot-drawing of a glass bar 1 is performed. Previously to the hot drawing, an outside sia. measuring device 10 is operated to scan from a right end toward a left end of the external periphery of the glass 1 to measure the outside dia. in the range over an effective length of the glass 1, and the measured value is inputted to an operational treating device 11. Operated control signals areinputted into control units 12, 13 in the stage of hot drawing and a driving system contg. the motor 6 and a driving system contg. the motor 8 are controlled respectively, thus, the moving velocity of the heater 5 and the drawing device are set appropriately corresponding to the variation of the outside dia. of the glass. |
