hp tooling 2020 #1

machining center
forceps halves in just three minutes. Thanks to the automation
system, it can do this around the clock, largely
without supervision. The machine also features impressive
repeat accuracy and thus quality of manufactured parts. In
addition, it significantly surpasses the throughput performance
of the other machining centers installed on site.
Development partnership in automation
We chose SW first of all because we were impressed by the
productivity of the double spindle concept. Another aspect
was their impeccable references as well as the rela tive proximity,
which would mean short response and travel times
both during the joint development phase to come and also
for any service calls that might be needed. The initial contacts
in the summer of 2017 led to a partnership-based collaboration
during which the possibilities for automation
BA 321
The BA 321 is the two-spindle version of a series
that is available as a one-, two- or four-spindle
machining center depending on the task. It is
suitable for machining workpieces made of aluminum,
cast iron, titanium or steel.
The heart of the monoblock is the working area with
dimensions of 300 x 500 x 375 mm and the spindles,
which are movable in three-axes. The spindles with
HSK-A63 interface reach speeds up to 17,500 rpm
with an output of 32 kW (4200 rpm, 40 % duty
cycle) and a torque of 72 Nm. The spindle distance is
300 mm. The weight of the system is about 8500 kg,
while the standard installation dimensions are
3.60 x 3.13 x 6.00 m (w x h x d). The series 3 is available
as a single-station machine or with a double
swivel carrier.
The feed of the three-axis unit is provided by sturdy
ball screw drives, with rapid traverse axis reaching
speeds of 65/75/75 m/min (x-, y-, z-direction) and axis
acceleration rates of 10, 10 and 15 m/s 2 respectively
with a maximum feed force of 8000 N. The pick-up
tool changing system has a capacity from 2 x 20 to
max. 2 x 60 tools in the two-spindle variant. Tools up
to Ø 70 mm (160 mm with free adjacent slot) with a
maximum length of 275 mm and a maximum weight
of 7.5 kg can be picked up. The chip-to-chip time is
about 2.5 s. The Sinumerik 840 D sl, Bosch Rexroth
IndraMotion MTX or Fanuc 30i are available as
control unit.
of machining processes was clarified. This was followed by
joint design and development of a special machine based
on the model BA 321.
Special press-drawn sections in three different dimensions
are used as raw material. The forceps halves are
carved out of the sections and are not separated by sawing
until the last work cycle. This neatly sidesteps clamping
problems with the extremely slender and delicate forceps
halves from the outset. The final saw cut is made so that
a minimal amount of burr remains to prevent the pieces
from falling down. Otherwise the very delicate tips of the
forceps could be damaged.
The forceps are removed by special adapters loaded into
the spindles from the tool maga zine. They are used to hold
the forceps parts and break off remaining burrs. Then
they are deposited individually on a transport drawer and
moved by conveyor belt to the removal station, where they
are manually inserted in basket racks for the next work
cycles. “The joint development of automation was very
efficient,thanks to the professiona lism of both teams,”
recalls Frank Pauschert.
Delivery and commissioning
Joint development and project planning as well as setup
and trials up to acceptance lasted until June 2018. The necessary
tools were implemented during this phase and an
initial NC program was created based on customer requirements.
After acceptance was completed, the system was
placed in operation at the operating site in June/July 2018.
Since then there have been tests as well as programming
for a total of 18 product variants. The actual ramp-up
began in November 2018. Production has already been
running in 24/6 operation since March 2019, with the system
sometimes running for up to a week with no human
interaction other than supplying material and removing
finished milled parts.
Satisfied with quality, support and service
Thanks to "life startUp" production monitoring in the first
week after commissioning, the employees became familiar
with operating the machine quickly and were able to work
independently with it. With “life data”, an online service
of SW, the machine is continually connected online
to SW, where essential machine parameters are moni tored
nonstop. If problems come up, action is taken immediately.
Good use has already been made of this service, as the machine
operator was supported by remote diagnostics.
“life help” also turned out to be very helpful: when
problems occasionally came up, it provided quick and very
competent consulting, and if a service employee was needed
at all, he was often on site for less than an hour. Without
this service there is much that would not have worked,
or would have taken much longer. An additional BA 321
has already been ordered.
further information: www.sw-machines.de
no. 1, 2020, March
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