HUF North America

HUF NA was producing a lock housing from their zinc die cast machine at a rate of one part every 22 seconds. Their desire was to complete manufacturing of this part prior to sending it for assembly at another plant. This part had (2) features to be cut, part probing to be done, and load/unload to be done in 22 seconds or less.

Assessment
The part needed two operations to complete the manufacturing process. We needed to put a groove in the throat of the casting and then tap (2) holes on top of the part. In addition the customer wanted to probe this groove feature to assure we are within the part tolerance of +/-.004. The automation process had it's own challenges. Not only did the Fanuc robot we were installing have to load and unload two machine fixture locations in a short period of time, it also needed to be interfaced with the existing Reis robot that was unloading the die cast machine.

Solution
The solution offered by Ellison Technologies consisted of supplying a Fanuc M6iB robot to interface with their existing Reis robot. The Fanuc robot would then be coupled to a Fanuc Robodrill, machining center, model T14iD with pallet changer. Other options required on the Robodrill were high pressure through the spindle coolant and gauging. The product flow would be as such. The Reis robot would unload the die cast machine and place the part on a staging fixture. The Fanuc robot would then take the part and load it onto a fixture mounted on a pallet in the Robodrill. The fixture would hold two parts. One in an upright position, for machining the I.D. groove in the throat. The other laying flat, for the tapping of the two holes. The Robodrill holds two pallets with two exact fixtures mounted to them. Fixtures incorporated seat sense for proper part loading and live hydraulics for clamping the parts. The Fanuc Robot would then load an additional part and clamp the fixture. Once clamp and part seat were confirmed the robot would cycle start the Robodrill. The Robodrill would then machine the groove, then form tap the two holes and then gauge the depth of the groove in the throat if the cycle required and offset the machine accordingly. During the machining process the Fanuc robot would be unloading and loading two more parts on the next pallet. As soon as the parts were loaded, the other pallet would be coming out and the process would keep going. The finished parts were placed on an exit conveyor and there was a set cycle for the robot to set parts on an inspection conveyor at a given interval. The Robodrill was also programmed to output the last twenty five offsets made from the gauging routine to a printer.

End Result
The end result was a very satisfied cusomer! We were able to achieve a cycle time of 21 seconds per part. We assured limited defect by probing the part every 10th piece. The Fanuc RoboDrill's fast rapids, tapping speeds and pallet change time kept the cycle time below the goal of 22 seconds per part. The M6iB robot provided an unmanned cell with constant and predictable throughput.