June 3, 2016
Recently a global supplier of compressors decided to rethink its process for making a series of bearing housings. According to the Production Manager, “After analyzing quality control and machine maintenance data we determined it was time to replace some of our machine tools. However, we didn’t want to simply buy new machines, we wanted to find a better way to make this part. At that time, we were performing two operations on a turning machine, manually moving the part to a horizontal milling machine for two more operations, removing the part to press a babbitt insert into place, and then taking the part to a grinder for two finishing operations.
“Obviously this meant making multiple setups and requiring our machine operators to handle the workpiece several times. Additionally, we had quite a bit of Work-In-Process at any given time. Because of the way the process flowed, we would have 3 – 4 parts staged for turning, another 3 – 4 staged for milling and the same for grinding. So reducing WIP became an important goal.”
Realizing that the answer was to replace the turning and milling machines with a single, multi-function machine tool, the manufacturer looked at a number of options and, with assistance from CNC machine dealer Morris South, selected an Okuma Multus B400 X 1500 twin spindle, multi axis machine that could complete all of the machining operations in one setup.
However, while replacing the turning and milling machines with the Multus was a significant improvement, they needed to take an additional step to enable one operator to handle both the machining center and the grinding machine, while also reducing WIP. Morris Sales Engineer Mark Lind and Application Engineer Jeff Pullen suggested adding a robot to load and unload the parts from the machining center.
Okuma America’s authorized robotics integrator, Gosiger Automation, was brought in to develop a solution that met all of the company’s requirements. Now the operator loads raw castings onto an inbound conveyor that carries the workpieces to the pick-up station. There, a Fanuc R-1000iA/80F industrial robot uses iRVision to identify the radial orientation of the casting, after which the robot places the part into the main (left hand) spindle for the first operation. Once the part is loaded into the main spindle, the robot repositions to unload a finished part from the sub (right hand) spindle where secondary operations were performed, and sets it on an outbound conveyor. Next the part travels to the unload station where it is inspected and the babbitt insert is pressed into place. Finally, the part is placed in the grinding machine for finish grinding the babbitt insert I.D. and one O.D. on the housing.
As a result, the bearing housings are now machined in a true one-and-done process. Thus there are no partially machined parts waiting for the next phase. According to the Production Manager, “We’ve reduced WIP by 80%, seen a significant improvement in part quality and the robotic automation means 30% less labor costs than if we operated the machining center manually. Also the new system provides extra capacity, so we’re able to process additional parts in the cell. Gosiger Automation and Morris South worked closely with us on the cell design and installation, trained our people to operate the existing process and also adapt the process to make additional parts.”
Gosiger Automation specializes in machine tool loading/unloading, material handling, palletizing, automated inspection, and material removal applications backed by 90+ years of machine tool experience. To learn more call (937) 228-5174.