Driving device of motors for rolling rolls

Abstract

A driving device driving motors of rolling rolls that corrects asymmetry between top and bottom roll driving systems of a twin-drive rolling mill in which top and bottom rolling rolls are driven by upper and lower motors, respectively, so that torques propagate to the top and bottom rolling rolls simultaneously. To this end, an upper/lower axis system imbalance correction section that corrects inequalities of torques propagating to the top and bottom rolling rolls is provided in either one or both of an upper motor control section that controls the upper motor and a lower motor control section that controls the lower motor in a driving device of motors for rolling rolls used in a rolling mill. The top and bottom rolling rolls are driven by the upper motor and the lower motor, respectively, and one of the upper motor and the lower motor is located on a rolled material. Thus, torques propagate to the top and bottom rolling rolls simultaneously.

1 . A driving device driving motors of rolling rolls in a rolling mill in which top and bottom rolling rolls are driven by an upper motor and a lower motor, respectively, and one of the upper motor and the lower motor is located on a rolled material side, as compared to the other motor, comprising:
 an upper motor control section that controls the upper motor, and   a lower motor control section that controls the lower motor, wherein at least one of the upper control section and the lower control section includes an upper/lower axis system imbalance correction section that corrects inequalities of torques propagating to the top and bottom rolling rolls.   
   
   
       2 . The driving device driving motors of rolling rolls according to  claim 1 , wherein
 the upper motor control section comprises
 an upper motor speed controller that receives, as an input, deviation of actual speed of the upper motor from a speed standard for the upper motor and obtains a torque standard for the upper motor, and 
 upper motor torque control means that controls torque of the upper motor so that the deviation of the actual speed of the upper motor from the speed standard for the upper motor becomes zero, 
   the lower motor control section comprises
 a lower motor speed controller that receives, as an input, deviation of actual speed of the lower motor from a speed standard for the lower motor and obtains a torque standard for the lower motor, and 
 lower motor torque control means that controls torque of the lower motor so that the deviation of the actual speed of the lower motor from the speed standard for the lower motor becomes zero, and 
   the upper/lower axis system imbalance correction section precedes at least one of the upper motor control section and the lower motor control section.   
   
   
       3 . The driving device driving motors of rolling rolls according to  claim 1 , wherein
 the upper motor control section comprises
 an upper motor speed controller that receives, as an input, deviation of actual speed of the upper motor from a speed standard for the upper motor and obtains a torque standard for the upper motor, and 
 upper motor torque control means that controls torque of the upper motor so that the deviation of the actual speed of the upper motor from the speed standard for the upper motor becomes zero, 
   the lower motor control section comprises
 a lower motor speed controller that receives, as an input, deviation of actual speed of the lower motor from a speed standard for the lower motor and obtains a torque standard for the lower motor, and 
 lower motor torque control means that controls torque of the lower motor so that the deviation of the actual speed of the lower motor from the speed standard for the lower motor becomes zero, and 
   the upper/lower axis system imbalance correction section is within a speed control loop of at least one of the upper motor control section and the lower motor control section.   
   
   
       4 . The driving device driving motors of rolling rolls according to  claim 1 , further comprising a load balance calculation section that suppresses load imbalance of the upper and lower motors by adding an imbalance correction amount, calculated from torque current standards for the upper motor and the lower motor, directly to the torque current standards, wherein the load balance calculation section precedes the upper/lower axis system imbalance correction section. 
   
   
       5 . The driving device driving motors of rolling rolls according to  claim 1 , wherein the upper/lower axis system imbalance correction section corrects inequalities of torques propagating to the top and bottom rolling rolls by using physical parameters of a spring and mass system that approximately express a top roll axis system extending from the upper motor to the top rolling roll and a bottom roll axis system extending from the lower motor to the bottom rolling roll. 
   
   
       6 . The driving device driving motors of rolling rolls according to  claim 5 , wherein the spring and mass system that approximately expresses the top and bottom roll axis systems is a two-mass point system. 
   
   
       7 . The driving device driving motors of rolling rolls according to  claim 2 , further comprising a load balance calculation section that suppresses load imbalance of the upper and lower motors by adding an imbalance correction amount, calculated from torque current standards for the upper motor and the lower motor, directly to the torque current standards, wherein the load balance calculation section precedes the upper/lower axis system imbalance correction section. 
   
   
       8 . The driving device driving motors of rolling rolls according to  claim 3 , wherein
 the driving device further comprises
 a load balance calculation section that suppresses load imbalance of the upper and lower motors by adding an imbalance correction amount, calculated from torque current standards for the upper motor and the lower motor, directly to the torque current standards, wherein the load balance calculation section precedes in front of the upper/lower axis system imbalance correction section. 
   
   
   
       9 . The driving device driving motors of rolling rolls according to  claim 2 , wherein the upper/lower axis system imbalance correction section corrects inequalities of torques propagating to the top and bottom rolling rolls by using physical parameters of a spring and mass system that approximately express a top roll axis system extending from the upper motor to the top rolling roll and a bottom roll axis system extending from the lower motor to the bottom rolling roll. 
   
   
       10 . The driving device driving motors of rolling rolls according to  claim 3 , wherein the upper/lower axis system imbalance correction section corrects inequalities of torques propagating to the top and bottom rolling rolls by using physical parameters of a spring and mass system that approximately express a top roll axis system extending from the upper motor to the top rolling roll and a bottom roll axis system extending from the lower motor to the bottom rolling roll. 
   
   
       11 . The driving device driving motors of rolling rolls according to  claim 4 , wherein the upper/lower axis system imbalance correction section corrects inequalities of torques propagating to the top and bottom rolling rolls by using physical parameters of a spring and mass system that approximately express a top roll axis system extending from the upper motor to the top rolling roll and a bottom roll axis system extending from the lower motor to the bottom rolling roll. 
   
   
       12 . The driving device driving motors of rolling rolls according to  claim 7 , wherein the upper/lower axis system imbalance correction section corrects inequalities of torques propagating to the top and bottom rolling rolls by using physical parameters of a spring and mass system that approximately express a top roll axis system extending from the upper motor to the top rolling roll and a bottom roll axis system extending from the lower motor to the bottom rolling roll. 
   
   
       13 . The driving device driving motors of rolling rolls according to  claim 8 , wherein the upper/lower axis system imbalance correction section corrects inequalities of torques propagating to the top and bottom rolling rolls by using physical parameters of a spring and mass system that approximately express a top roll axis system extending from the upper motor to the top rolling roll and a bottom roll axis system extending from the lower motor to the bottom rolling roll. 
   
   
       14 . The driving device driving motors of rolling rolls according to  claim 9 , wherein the spring and mass system that approximately expresses the top and bottom roll axis systems is a two-mass point system. 
   
   
       15 . The driving device driving motors of rolling rolls according to  claim 10 , wherein the spring and mass system that approximately expresses the top and bottom roll axis systems is a two-mass point system. 
   
   
       16 . The driving device driving motors of rolling rolls according to  claim 11 , wherein the spring and mass system that approximately expresses the top and bottom roll axis systems is a two-mass point system. 
   
   
       17 . The driving device driving motors of rolling rolls according to  claim 12 , wherein the spring and mass system that approximately expresses the top and bottom roll axis systems is a two-mass point system. 
   
   
       18 . The driving device of driving motors for of rolling rolls according to  claim 13 , characterized in that the spring and mass system that approximately expresses the top and bottom roll axis systems is a two-mass point system.