| 摘要 |
PURPOSE:To ensure the stability of production by a method wherein casting is performed under the state that the tension of a wire-shaped electrode is controlled to be constant. CONSTITUTION:In order to control the tension of a wire, at first, a target tension is determined and a torque is roughly calculated so as to set the input voltage of a torque motor 4. The torque of a brake motor is set a little larger than that of the torque motor 4. The tension, which is roughly set as mentioned above and indicated with a tension detecting mechanism 7, is made equal to the target tension by finely controlling the input voltage of the torque motor. In this case, care must be taken to keep the torque of the brake motor larger than that of the torque motor at all times. Under the above-mentioned setting condition, even when the tension gets loose due to the linear expansion of the wire, the torque motor automatically rotate so as to keep the tension constant. Further, when the change of the tension is intended, the change of the set value of the torque motor is enough. |
