Constant Torque Control; Outline - Mitsubishi Electric M800VW Series Programming Manual

M800V/M80V Series PLC Programming Manual (2/2)
14 PLC Help Function

14.31 Constant Torque Control

14.31 Constant Torque Control

14.31.1 Outline

 Constant torque control
By setting "Constant torque control request axis" signal to ON from PLC, the servo motor of the designated axis outputs
torque set by the parameter in a constant direction. By using this function for a servo motor which drives a bar feeder, the bar
feeder can press the workpiece with constant torque regardless of whether it is during movement, stop, or acceleration/
deceleration.
By setting "Proportional torque stopper control request axis" signal to ON from PLC, proportional torque stopper control
enables a servo motor of the designated axis to generate torque set by the parameter in the stopper direction. When position
droop is generated, the motor generates torque in proportion to the position droop in the stopper direction to keep the stopper
position.
Note
(1) Do not cancel the constant torque control or the proportional torque stopper control for an axis moving under manual or
automatic operation. Otherwise the fixed workpiece, fixed turret, etc., may get loose, and it is dangerous.
[Example of constant torque control]
Chuck
Cutting-off tool
(closed)
Retraction
 Droop cancel under constant torque control
Droop cancel under constant torque control cancels the position droop generated during constant torque control without
moving an axis.
Note that the droop cancel under constant torque control must be commanded while the axis is pressed against the
workpiece, etc.
 Proportional constant torque control
Proportional torque stopper control generates constant torque in the stopper direction according to the value designated to
the parameter. When position droop is generated, the motor generates torque in proportion to the position droop in the
stopper direction and to keep the stopper position.
Spindle
Workpiece
Constant torque control axis
Z axis
Chuck (opened)
Chuck (closed)
Bar feeder pressing arrow
Constant torque stopper
Constant torque stopper
Movement command tracking
constant torque stopper
783 IB-1501668-B