| 摘要 |
PURPOSE:To prevent the fluctuation in the rotating speed of pinch rolls occurring in the mechanical backlash of a driving system for rolls by dividing the plural pinch rolls to two groups, and giving a difference to the field currents of the DC motors of the respective groups. CONSTITUTION:Pinch rolls 2 are divided to two groups; A and B in a continuous casting installation. Electricity is fed from a common electric power source 5 for speed control to the armature circuits of DC motors 3a, 3b in both groups and the command for the rotating speed corresponding to the drawing speed of an ingot is inputted. Individual field current controllers 6a, 6b are provided to field circuits 4a, 4b of both blocks, and an electric current smaller than the circuit 4a is supplied to the circuit 4b from a field power source 7. Then, the thrust of the pinch rolls 2 of the other group act as a brake. On the other hand the pinch rolls 2 of the one group are reduced by the own weight of the ingot 1 and since the thrust does not exceed the resistance force between the ingot 1 and the rolls 2, the rolls act always as a propulsive machine. |
