Among other improvements, Eaton wanted to incorporate a real-time test data system that could be fully integrated with its plant-control network to facilitate government tracking and record keeping.  



Eaton Aerospace, a subsidiary of Eaton Corp. (Cleveland), assembles a wide range of products for the aviation industry, including everything from cockpit switches and hydraulic motors to the pumps used in the aerial refueling systems employed by the U.S. Air Force.

Recently, the company hired Quality First Systems Inc. (QFSI-Davisburg, MI) to help it upgrade one of the leak-testing machines it uses to ensure the quality of the quick-connect hydraulic control circuit couplings it manufactures.



The company also wanted to eliminate the analog gauges it had been using; eliminate the need for any kind of visual leak inspection; increase the number of parts being tested at a time to increase throughput; reduce operator contact with the machine oils being used; create a fully enclosed and safer machine; and automate the part coupling and decoupling process.

The latter feature was necessary because Easton tests the two halves making up each coupling in both their coupled and uncoupled state.

To solve the coupling problem, QFSI created a customized, automated fixture manifold that can accommodate a half-dozen assemblies at a time and be positioned vertically to within 0.005 inch, using a 3-inch-diameter lead screw coupled to an Allen-Bradley servo system from Rockwell Automation (Milwaukee). The fixture is capable of withstanding up to 47,000 pounds of backpressure during testing, and allows the parts to change out three times faster than previously, when an operator had to do the job manually.

Cleanliness and oil carryover from the tested parts were also significantly improved by adding a fluid purging cycle to the test system, which removes excess fluid from the parts at the end of each test.

In operation, the system uses a compact Allen-Bradley logix PLC with a Panelview Plus color touch screen. The touch screens for this and a number of other automated systems in the Eaton plant have been standardized so that employees can easily shift from one work or test cell to another without the need for extensive training.

The system has also been configured with a bar code scanner to identify the product being tested, automatically recall the product’s specific test parameters from the server, and upload the test data and results to the server file at the end of testing.

Fine resolution, high-quality pressure transducers have been incorporated to record the pressure differentials during the testing. Results are displayed on the touch screen in real time. Warning messages notify an operator in the event the system finds a bad part.

The machine also tracks the number of parts tested, as well as the number of good parts and the number of rejects, allowing Eaton to pinpoint areas of inefficiencies in the manufacturing process.

Other features include a low-fluid warning system, fluid temperature control and an explosion-proof design to accommodate the use of inflammable solvents.

For more on automated test and assembly systems, visit www.qfsi.com or call 248-922-4780.

For more on controllers and other automation components, visit www.ab.com.