| 摘要 |
PURPOSE:In a tension control apparatus for applying tension to a strip material at time of transport, to control speed in case of a break in the material and heighten the safety by switching a tension generating motor from current-controlled to speed- controlled, when a break in the material is detected. CONSTITUTION:A bridle roll 2 is controlled by a bridle roll motor control unit 3 in order to apply tension to a strip 2 at time of transporting the strip 2. That is, contacts 14, 17 are turned on and a contact 16 is turned off through a logic circuit 9 when receive a signal ''IN'' of tension to make a bridle roll motor current-controlled through a current controller 11. After T seconds, a tension signal 8 of a tension meter 7 is checked, and if the signal 8 is off, it is judged to be break in the material, so the contacts 14, 17 are turned off, the contact 16 being turned on. Thus, a tension setting device 4 and a speed limiter setting device 5 are disconnected, and a speed reference 6 is connected to change current-controlled to speed-controlled. |
