24
Intelligent machining
– Adaptive Feed Control option (AFC)
Besides the feed rate for each block or
cycle, HEIDENHAIN controls have always
allowed the programmer to enter a manual
compensation through the override
potentiometer to adjust for the actual
machining situation. But this always
depends on the experience and, of course,
the presence of the operator.
Adaptive feed rate control (AFC) automati-
cally regulates the feed rate of the TNC,
taking into consideration the respective
spindle power and other process data. In
a teach-in cut, the TNC records the maxi-
mum spindle power. Then, before actual
machining, you define in a table the re-
spective limit values between which the
TNC can influence the feed rate in the
“control” mode. Of course, various overl-
oad reactions can be provided for, which
can also be defined by your machine tool
builder.
Adaptive feed rate control offers various
advantages:
Optimizing the machining time
Fluctuations in dimensions or material
(blowholes) can occur, particularly in cast
parts. With a corresponding adaptation of
the feed rate, the control tries to keep the
previously “learned” maximum spindle
power during the entire machining time.
The total machining time is shortened by
an increased feed rate in the machining
zones with less stock removal.
Tool monitoring
The TNC's adaptive feed rate control
continuously compares the spindle power
with the feed rate. As a tool becomes
blunt, the spindle power increases. As a
result, the TNC reduces the feed rate. As
soon as the feed rate falls below a defined
minimum, the TNC reacts with an error
message or by switching off. This helps to
prevent further damage after a tool breaks
or is worn out.
Protection of the machine mechanics
Reducing the feed rate down to the
reference value whenever the learned
maximum permissible spindle power is
exceeded also reduces the strain and wear
on the machine. It effectively protects the
spindle from overload.
To Next Page
Loading...
