
B–63833EN–1/02
9. SPINDLE SPEED FUNCTION
438
NOTE
If a specified voltage of 10 V is already higher than the
acceptable input voltage for the spindle drive system,
calculate the spindle speed that corresponds to 10 V using
a proportional calculation method and use it instead. Now,
in response to the specified S code, the speed command
and gear select commands (GR3O, GR2O, GR1O) are
output to the spindle motor as shown in Fig. 9.3. (a).
D Gear change point during tapping cycle mode (G84, G74)
In case of G84 (tapping cycle) or G74 (counter tapping cycle) the gear
shift speed is changed by parameter SGT(No. 3705#3). In this case,
gear shift is performed at the speed set by parameter nos. 3761 and
3762 (Fig. 9.3 (b)).
D : Gear shift point (parameter No. 3761) for low/high speed change (or low/medium speed change) (set by
parameter as min
–1
value) during tapping.
E : Gear shift point (parameter No. 3762) (3-stage gear) for medium/high speed change (set by parameter as
min
–1
value) during tapping.
GR2O
GR1O
10V
AB
CDE
Spindle motor speed command
(analog voltage output)
Upper limit
voltage of
spindle
motor speed
(Vc)
Spindle speed
command
(S code input)
Vc: Voltage for upper limit of spindle motor speed
Fig. 9.3 (b) S code input and output voltage (in tapping)
D M type gear change method B (M series) (Fig. 9.3 (c))
The speed (min
–1
) at which the low-speed and the high-speed gears are
changed over can be set as a parameter (No.3751, 3752) by setting
parameter SGB (No. 3705# 2). When a 3-stage gear is used, it is possible
to set the speeds (min
–1
) for switching low-speed and medium-speed
gears, and medium-speed and high-speed gears, using parameters No.
3751, 3752.