Need to Measure or Verify Spring Rates, Insertion Force
or Assembly Forces at Very High Speeds?
The Signature Technologies
SA-2000
“SAM” module, and Signature
Technologies “SamView™” Software
package can be used to measure the rate of force change versus component
displacement of specific features on manufactured parts such as connector parts
or small contacts. High speed is a
natural for this application. This
application can also verify insertion force.
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
the proper dynamic characteristics. FOR
EXAMPLE the individual keys on a keyboard could be tested for compliance to a
given “feel” specification. The
load cell shown with modification can be used in insertions tests for
connectors.
The system works by compressing, or deflecting the element to
be tested with a load cell specifically designed for the purpose.
The illustration is of a cell designed to measure the “rate” of
spring or flexure components. The load cell is attached to an oscillating mechanism
(possibly the forming press slide), and the SAM™
module captures the force information as the test piece is deflected.
It can also be used for Insertion / withdrawal force measurements.
The measurement can either be calibrated, or comparative depending on the
application. Calibrated
measurements will give the force vs. flexure displacement of the test piece at
the testing point. Post processing
can be done to supply slope and spring rate information.
Inertial compensation is used for high-speed oscillatory service to
eliminate inertial forces from the measurement.
In slow applications the inertial compensation is not required.
Multiple sensors can be used in cases where there are
several different features to measure, or where multiple measurements are
required to insure proper formation of a single feature.
The SAM™
module can handle inputs in groups of 8 up to 56 total points.
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.
For a .pdf file copy of this bulletin please click here.
