Stock Machines, Workhandlers Tackle Complex Automation Task

The machining alone is a challenge: tough interrupted cuts; sequential facing, center-drilling and between-centers turning at a single station; and +/- 0.0004 in. accuracy. To make it more challenging, all operations were to be fully automated for hands-off production of 240-part batches. The customer is a large automotive parts manufacturer who has several other Amada Wasino automated cells and systems. They're committed to automation because of its competitive advantages.

This particular job is the kind of application that Amada Wasino thrives upon. Applying its standard milling/turning A-Series machine and two LJ-Series turret lathes to the job, it met the machining requirements. And between-machine transfers were achieved with off-the-shelf, bolt-on transfer modules that compressed the cell assembly, application development and delivery time to less than three months.

The workpiece is difficult to hold. A forged, flanged spindle, the part requires front- and back-side work and a pattern of four bolt holes in the flange, which is very thin in cross-section. Machining includes aggressive roughing steps. The forces involved in roughing, plus the accuracy required in finishing, made it necessary to hold the part between centers at the second (roughing) and third (final finishing) workstations.

Automation of the system begins with Amada Wasino's built-in SR gantry loaders. These straight-line, two-axis programmable units are available with different hands for different part configurations. An off-the shelf "shaft hand" was selected for loading and unloading the parts.

Workpiece queuing is addressed with another pre-packaged modular solution, the WP1 Palletizer. The two-axis system stacks 24-workpiece pallets ten-deep and feeds them vertically as each pallet tray is emptied. The only special tooling required are the trays themselves, which are laser-cut to fit the part. Amada Wasino engineers designed the pallet trays to nest and orient the workpieces.

The WR1 Palletizer, the SR-1 gantry robot and the "shaft hand" are all standard, modular components that are each associated with an individual machine. Only one other element is required for full automation: two of Amada Wasino's straight-line between machine transfer units. These, too, are stock items.

The first machine, an A12 with an SR-1 robot, chucks the part on the shaft end and faces, center drills and drills the bolt-hole pattern from the back side of the part. The A12 is a four-axis machining center that holds the workpiece in a lathe-type chuck, and which has full turning capability.

The second machine, an LJ-5 turret lathe with an SR-1 gantry loader, receives the workpiece into a chuck that has two pie-shaped jaws, gripping on the turned outside diameter of the flange. (Amada Wasino engineers achieved better concentricity by going from a three-jaw to a two-jaw pie chuck.) The part is center-drilled and faced before the tailstock quill is actuated. This strategy eliminates an additional setup. The part is then rough-turned on the shaft and the front face.

A third operation finish-turns the shaft end and faces both sides of the flange, between centers. A face driver is used on this machine, another LJ-5 with an SR-1 robot. A tolerance of +/- 0.0004" is held on the main shaft diameter.