
B-63783EN-1/01 9.SPINDLE FUNCTION
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9.11 SPINDLE SPEED FLUCTUATION DETECTION
General
If the actual spindle speed becomes lower or higher than that specified
because of the condition of the machine, an overheat alarm (SP0242) is
issued, and spindle speed fluctuation detection alarm signal SPAL is
output. This signal can be used to prevent the guide bushing from
burning out.
Method for detecting spindle speed fluctuation
If a difference between the actual spindle speed and the specified
spindle speed becomes larger than the allowable fluctuation width
specified in the address R and I commands in a G26 command block or
parameter Nos. 5702 and 5721 (if the following two conditions are
satisfied), an alarm is issued to indicate that the fluctuation has become
higher than a permissible level.
(1) |Sc - Sa| ≥ Sr
(2) |Sc - Sa| ≥ Si
Sc: Specified spindle speed
Sa: Actual spindle speed
Sr: Spindle speed fluctuation range calculated from spindle speed
fluctuation ratio (address R command in a G26 block or
parameter No. 5702)
If parameter FLR (bit 1 of parameter No. 5808) is 0
Sr = Sc * r / 100
If parameter FLR (bit 1 of parameter No. 5808) is 1
Sr = Sc * r / 1000
Si: Permissible range of fluctuation that does not cause a spindle speed
fluctuation detection alarm to be output (address I command in a
G26 block or parameter (No. 5721) setting)
NOTE
Even when the conditions for issuing an alarm related to
spindle speed fluctuation detection have not been
satisfied in spindle speed detection enabled mode (G26),
a spindle speed fluctuation detection overheat alarm is
issued if:
- A spindle speed has been specified, and the actual
spindle speed remains at 0 min
-1
for at least one second.