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APPLICATION NOTE: 1746sc-INI4vi
in the Automotive Industry
 "A
lot is riding on your tires" is a common phrase used by the automobile
industry. This is often interpreted that there is more to an automobile
than meets the eye. Spectrum Controls, with the help of Rockwell
Automation distributor Kendall Electric, located in Indiana, found
out the truthfulness of this statement.
Guide Engineering, a systems integrator
in Fort Wayne, Indiana, designed a bearing installation system
for Dana Corporation, a major automotive parts manufacturer. Dana
Corporation supplies auto and truck differentials to Chrysler, Renault,
Nissan, etc.
The application consists of a press
system that aligns and inserts axle wheel bearings into the differential
housing. These wheel bearings support the drive axles and brake
assemblies. The bearings must be properly seated in the housing
in order to function properly and insure long life. Alignment errors
can result in premature bearing failures.
The machine consists of bearing alignment
fixtures and press arms. The bearing is placed in the alignment
fixture and the differential assembly is moved into place.
 The
press arms then insert the bearings into each axle tube housing.
Load cells are fixed to the bearing
insertion arms. The load cell provides a linear force scale, based
on an insertion pressure, which correlates to a bearing insertion
distance. The load cells provide a 0 to10 volt signal that is read
by the Spectrum Controls 1746sc-INI4vi module.
 The
machine operator can view a plot showing force against distance
as the bearing is inserted into the axle housing. Abnormalities
in the plot can help to diagnose bearing alignment issues; insertion
errors, bearing housing seating problems, and machine wear issues.
The PLC used in this process is an
Allen-Bradley SLC-500 with Spectrum Controls' 1746sc-INI4vi four
(4) channel isolated input module. The customer selected the
176sc-INI4VI particular
module for the following features:
- 16-bit analog resolution - The high
resolution allows the end user to view small changes in insertion
force.
- On the fly configuration and enable/disable
feature, handled without the need of circuit jumpers - Simplified
module configuration minimizes system downtime should the system
fail.
- Four selectable filter frequency
settings for each channel - The machine resides in a high noise
environment. The selectable filters allow the inputs to be tuned
to minimize the effect of floor noise.
- 750V channel-to-channel isolation
- There are a numbers of sources of electrical noise in the operating
environment. Channel to channel isolation insures that signal
cross talk does not effect module performance.
The harsh conditions of an assembly
line are a challenging environment for PLC operation. Spectrum Controls
I/O modules are designed for these types of environments. Features
such as high levels of channel-to-channel isolation can save the
day for the end-user.
Spectrum Controls I/O modules offer a
lot more than meets the eye.
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