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Automatic Connecting Rod Assembly
Gage
 Gage
Parameters
GAGING SYSTEM: Air-to-electronic
OPERATION: Automatic
NUMBER OF CHECKS: 10
READOUT: MicroCAGTM
CLASSIFICATION: Size
FEATURES: Automatic measuring, laser engraving, and sorting into two
sizes based on crank bore sizes.
The Challenge
A common dilemma in assembly operations is matching mating parts
when there are incremental sizes from which to choose. A case in
point is Harley-Davidson. The motorcycle manufacturer often had
trouble matching the correct size cranks, bearings and connecting
rods for its engines. The company needed to be able to sort the rods
into two different sizes so that operators could assemble the
correct crank bearing into each rod for proper fit.
The Solution
Edmunds Gages developed an automatic gage consisting of a
free-standing gage base, machine control cabinet, air gaging
fixtures, robotic pick and place mechanism, and our MicroCAGTM
microprocessor readout.
In addition to the
classification and Julian date, the automatic gage can also
laser mark the part with the Harley-Davidson logo.
In operation, an operator manually loads a rod and initiates the gaging
cycle. The gaging fixture is comprised of a four-station rotary
table with interchangeable part nests and air gage tooling. The
connecting rod crank bore is measured in four places to acquire ten
measurements. A good part within tolerance is categorized by the
minimum size witnessed during measurement.
The MicroCAGTM then directs the part, based on that size, to
another station in the gage where the part is laser marked with a
two-digit code so that assemblers can readily view which mating part
goes with it. Simultaneously, the gage also has the capability to
engrave the date and the company logo.
Once the part is measured and laser marked, it is picked up by
the robot and placed into one of two conveyors, classified by size,
and transported to separate areas in the assembly department. Parts
detected out of tolerance after initial measurement are returned to
the operator for visual assessment and distribution.
 The
Result
The gage cycle time is 15 seconds per part, laser marking included,
which is a great time and cost savings over manual gaging,
considering a total of 10 measurements are taken. Further, there are
no misassembled bearings on the final engine test stand.
Harley-Davidson now enjoys an infallible assembly process. Since the
gage has been installed, there have been zero connecting rod
assembly mistakes.
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