
B–64112EN/01
13. FUNCTIONS TO SIMPLIFY
PROGRAMMING
NC FUNCTION
119
Bell–shaped acceleration/deceleration can be used for rigid tapping.
Generally, using bell–shaped acceleration/deceleration can reduce the
required acceleration/deceleration time because the time constant of rigid
tapping can be decreased.
For bell–shaped acceleration/deceleration for rigid tapping, the linear
acceleration/deceleration constant and the time corresponding to the
bell–shaped curve are specified using parameters.
The bell–shaped acceleration/deceleration time for rigid tapping is the
sum of the time constant of linear acceleration/deceleration for the spindle
and rigid tapping axis (conventional parameter setting T1) and the time
corresponding to the curved portion (parameter setting T2).
Maximum per-
missible spindle
rotation speed
Time
Spindle rotation speed
T1
T2
2
T2
2
T1 = Time constant of linear acceleration/deceleration for
the spindle and rigid tapping axis
T2 = Time constant for the curved portion of bell–shaped
acceleration/deceleration
T1 + T2 = Time required for acceleration/deceleration
The actual time constant of liner acceleration/deceleration for the spindle
and tapping axis, T1, is determined according to a ratio of the maximum
permissible spindle rotation speed to the actually specified S. However,
the time constant for the curved portion of bell–shaped acceleration/
deceleration is not proportional to the actual S instruction, so a constant
acceleration/deceleration (specified using a parameter) is always
maintained.
13.2.2
Rigid Tapping
Bell–shaped
Acceleration/
Deceleration (M series)
M series