
2.EXPLANATION OF OPERATION MODES FANUC AC SPINDLE MOTOR αi series B-65280EN/05
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2.5.4 Explanation of Operation
(i) If spindle synchronous control is commanded when the two
spindles are rotating at different speeds (including stop state), the
two spindles are accelerated or decelerated to the commanded
speed then enter synchronous control state.
(ii) If the synchronous speed command is changed after synchronous
control state is entered, the spindles are accelerated or
decelerated to the new commanded speed with the parameter-set
acceleration while synchronous control state is held. If the
synchronous speed command is 0 min
-1
, the spindles stops in
synchronism.
(iii) If spindle synchronous control at a synchronous speed of 0 min
-1
is commanded when the spindles are in stop state, each spindle
automatically makes two to three turns to detect the position
coder one-rotation signal (as a preparation for spindle phase
synchronous control), then enters synchronous control state.
Next, when the synchronous speed command is changed, the
spindles are accelerated with the parameter-set acceleration while
synchronous control state is held, until the speed command is
changed.
(iv) When the seizure of a uniquely shaped workpiece needs to be
switched between the two spindles, the rotation phase (angular
displacement) of one spindle must match that of the other.
If a spindle phase synchronous control command is entered when
the two spindles are rotating in synchronous control state, each
spindle is controlled to have the parameter-set rotation phase (a
momentary speed change occurs at this time), then enters
synchronous control state again.
A rotation phase match can be secured by matching the reference
positions of the two spindles by parameter setting beforehand.
(v) If the two spindles enter synchronous control state at a specified
synchronous speed of 0 min
-1
, and a phase synchronous control
command is then entered, each spindle rotates and stops to
achieve a parameter-set phase. This operation is performed as if
spindle positioning (spindle orientation) is performed while the
spindles are stopped. As a result, the reference position of one
spindle matches that of the other (phase synchronization).
If the synchronous speed command is changed after the two
spindles seize a uniquely shaped workpiece, the two spindles are
accelerated to the new specified speed with the parameter-set
acceleration while synchronous control state is held.
(vi) Even in the state where the two spindles are seizing a workpiece
in synchronous control state, constant surface speed control can
be exercised.
However, even if a speed change greater than the parameter-set
acceleration is commanded, the speed changes within the
parameter-set acceleration.
(vii) Do not change the rotation direction command (SFRA, SRVA)
during synchronous control.