Got problems with spring back of
bending angles?
The Signature
Technologies
SA-2000 “SAM” module, and Signature
Technologies “SamView™” software package can be used to monitor bend
angles of manufactured parts. Not only that, but you can use it in closed
loop mode to make adjustments on the fly to get every part out right!
Instead
of sampling selected parts using an off-line gauging fixture, the
illustrated method can perform the same type of test every stroke of the machine
so that each part can be individually verified as having been formed acceptably
to tolerance. The measurement can
either be calibrated, or comparative depending on the application. Calibrated
measurements will give the dimensional variation at the sensing point.
Measurements can be performed with a variety of transducers but analog proximity
sensors usually have the best performance/cost ratio.
The system works by measuring the
displacement of the bent portion of the work piece relative to the dimensional
sensor implanted into the forming die. Timing of the measurement is critical, since
the measurement must wait until the part is no longer being held in an abnormal
position by the wipe down iron. Not signature-based measurement does not
work since it does not measure the part in the relaxed condition.
The
Graph
to the right shows the measurement signature, indicating the area of
the stroke where the part has been released by the forming tool, but is still
held in registration by the pressure pads.
Two
or more sensors can be used on wider work pieces to insure parallelism,
or flatness of the formed portion. The
SAM™
module can handle inputs in groups of 8 up to 56 total points.
If desired, Signature Technologies can provide
controls to adjust the forming station(s) dynamically based on the dimensional
measurements.
Signature
Technologies
can supply a wide variety of solutions
to various manufacturing process problems dealing with measurement, verification
of properties, tool condition, and machine health.
We can also “close the loop” by performing process adjustments in
response to specific variations in force, location, or shape of the work piece,
as well as more simple controls which can track and reject specific parts which
don’t meet specific quality criteria.
