PURPOSE: To roll a blank pipe in a steady state, and to equalize the torques of respective motors, by controlling a field system so that the magnetic flux density of a roll driving motor at the pipe feeding side is larger than that of a motor at the other side, after the pipe has been placed between two rolls.
CONSTITUTION: At the time of detecting the elapse of a given time by a timer from the time of detecting the start of biting a blank pipe 14 by load cells, etc. fitted respectively to a right roll 11 and a left roll 12, the magnetic flux density of a motor 11A for driving the right roll 11 is increased by increasing or decreasing the field current of the motor 11A. Accordingly, the load current, i.e. the torque of the motor 11A for driving the right roll 11 and the load current, i.e. the torque of a motor 12A for driving the left roll 12 are equalized. Thus, the productivity of a reeler is improved by reducing the overloads of the motors 11A, 12A and the cycle time of rolling.
MASUDA TOSHIICHI
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