41
about 25% is used to power pumps.
Drilling down a bit more, for mach-
ine tools, 24% of the total energy
consumption is for the cutting fuid
system. So the institute initiated a
research project with machine tool
builder DMG MORI ( us.dmgmori.
com ), cutting tool manufacturer
Sandvik Coromant ( sandvik.
coromant.com ), pump manufacturer
Grundfos ( us.grundfos.com ), and
fuid system supplier Bosch Rexroth
( boschrexroth.com ) to determine
the correlation between cutting
fuids and tool life with the objec-
tive of reducing the amount of
energy required for the system.
They tested turning, milling and
drilling operations, assessing the
correlation between the volume
fow of fuids and tool life. They
concluded that there is an optimal
fow rate based on the tool, the
operation and process parameters.
So, for example, in an external
cylindrical turning operation that
was run at v
c
= 150 m/min, a
p
=
3 mm and d = 0.25 mm. The fow
was adjusted from 2.2 to 6.8 liters/
min. And the determination was
made that the optimal rate of fow
is 4.5 liters/min, and that by using
that setting, the amount of power
required by the pump is 67%,
without having a negative impact
on tool life.
Other tests were conducted on rough
and fnish milling, with adjustments
made to the energy supplied to the
pump. In one test, they were able to
reduce the overall energy consump-
tion of the machine by 37% without
sacrifcing part quality or productivity.
Evidently, even if a company isn't
machining parts in Germany, there
is a huge advantage that can be
realized in energy use reduction by
paying attention to details, like the
amount of fuid fow used during
machining.
t Although the cutting fuid system
may not seem to be a major factor
in terms of energy use, an industry-
academic research project found that by
adjusting the amount of fuid pumped
during a machining operation, there can
be a considerable efect on the overall
energy consumption of a machine
without having a deleterious efect on
part quality or productivity.
0714ADP FEATURE Energy -- Digital Version.indd 41 6/17/2014 1:09:49 PM