Bottlenecks can occur anywhere on the production line. A common place for this problem to occur is the 90-degree corner, where products usually fail to move as efficiently and quickly as they do on straightaways.
Brake and suspension systems manufacturer BWI Group (BWI) of Kettering, OH, is well acquainted with this challenge. In early 2021, the company took steps to remove an ongoing bottleneck caused by a right-angle turn that serves as a buffer transfer point between its fully automated valve assembly and testing lines.
BWI explored several ways to transfer small parts in this compact space, including a conveyor system, which proved to be inefficient and cumbersome. Plant management then looked into using a robot to pick and place the parts. This involved working with Korvis, a company that engineers and builds multi-axis precision motion and positioning systems, to help choose and integrate the best robot and peripherals for the material handling application.
The two companies agreed that a practical choice would be a Motoman robot from Yaskawa America Inc., since BWI already had a Yaskawa robot installed at the plant. Taking this approach would make it easier to standardize operations.
Light Experts from both companies considered using a cobot in the tight corner area, but then rejected the idea since the application required no direct robot-human interaction. After further deliberation, they agreed on installing a four-axis MYS450F SCARA robot with a 6-kilogram payload capacity and end of arm tooling featuring a vacuum mechanism, and Keyence presence and optical sensors.
Although BWI system operators were familiar with Yaskawa robot programming, two workers attended Yaskawa Academy robot training to learn the ins and outs of the MYS450F. Another concern for BWI during installation was the robot’s ability to integrate well with other machinery on the production line. To better facilitate this, company leaders upgraded the SCARA robot’s software to perform well with BWI’s Siemens PLC.
During operation, the robot lifts each compact (6 by 12 by 60 millimeters) and lightweight (100 grams) valve part and moves it from the assembly zone to the testing one. Throughput is optimized because the robot is never idle.
If the test zone becomes out of synch with the robot for some reason and is not ready for part transfer, the robot places the assembly part into an opening on a 100-piece grid buffer tray (10 rows by 10 columns) that serves as a reserve part supply. However, if the assembly zone becomes out of synch with the robot for some reason, it picks an available assembly part from the grid tray and places it into the test zone load position.
Since being installed, the robot has eliminated the bottleneck by moving parts in a systematic and timely manner with high-speed precision. It also allows BWI to now perform part transfer six days per week, 20 hours a day. Management estimates current productivity to be around 80 percent, but anticipates reaching 90 percent in the near future.
Part pick-and-place is just one capability of the MYS450F, which has a horizontal reach of 450 millimeters and a vertical reach of 180 millimeters. Others include assembly, dispensing, part kitting, case packing, packaging, and solar and semiconductor processing. For more information, call 937-847-3200 or visit www.motoman.com/en-us.
