PURPOSE: To have an optimum control of tension in a continuous annealing plant for strips by calculating the mean value of load currents of drive motors and controlling load current in each section into balanced condition by the use of obtained mean value.
CONSTITUTION: The sensed value by the load current sensor device 10 in each section is placed into a mean current calculating device 11, and the mean value of load currents obtained thereby controls the load current in each section into balanced condition with the aid of a field generating current regulator device 12. A tension setting device 13 gives out a tension reference value for each section on the basis of the tension pattern stored in memory in accordance with the seam tracking between the preceding and the subsequent strip. This reference value is compared with tension values from the sensors 6aW6d and sent through a voltage regulator 5 and a power supply 4 to perform field control of motors. Thus the whole can be controlled using a pattern while the task for every motor in the section is restricted within a certain extent.
MATSUYAMA YOSHITAKE
KATAYAMA NATSUNOBU
