Original Date: 05/12/1997
Revision Date: 01/18/2007
Information : Unit Assembly Test Stands
Cincinnati Milacron’s Machine Tool Group (MTG) has developed and implemented four subassembly test units (Tool Changer Tester, Tool Storage Unit Tester, Subtable Unit Tester, and Automatic Work Changer Tester) for its assembly process. Developed as low cost and low technology ideas, these units reduce costs and runoff time of the machining centers; improve the quality and reliability of products; ensure consistent test procedures are followed; and reduce runoff times for acceptance testing of finished products.
The Tool Changer Tester simulates the tool mounting system of the machining center including the spindle, chain, and transfer arm. The unit verifies the electrical system and hydraulic line connections, checks cycle times, and runs reliability tests to ensure a proven subassembly is provided for final assembly. Benefits include reducing electrical technicians’ time by two hours per machine and eliminating rework by 95% at the machine runoff.
The Tool Storage Unit Tester is used to run-in the tool storage transfer chain, so that proper tension and clearances can be adjusted after the initial two-hour run. After the initial run, the chain tension will loosen up and must be reset to the proper specifications. The unit also verifies that the electrical connections and components are working properly.
The Subtable Unit Tester simulates the table interface with the machine to verify electrical continuity, good hydraulic seals, and proper tubing connections, and to ensure there are no leaks. Proper interface between the table and the machine is critical due to the intense labor required to remove and repair the machine should any problems occur after mounting. The unit is also used to set the pallet registration to a master gauge, which ensures table positioning accuracies. The Subtable Unit Tester has reduced the runoff time for the finished machine by 20 hours and produced an overall savings of 12 hours per machine.
The Automatic Work Changer Tester is a simulated table, load station, and pallet load capacity tester. The unit tests the extensive wiring required for assembly, and sets up the stops and proximity switches prior to final assembly to the machine and the installation of covers and guards. The Automatic Work Changer Tester has reduced electrical start ups by eight hours per machine, and provides the necessary reliability tests to ensure proper positioning and transfer of fully-loaded pallets.
The use of subassembly units, prior to the assembly of finished machines, has proven beneficial to Cincinnati Milacron. These units are very cost effective in reducing runoff test times and improving the quality and reliability of finished machines.
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