Kawasaki robot upgrade at Norgren delivers benefits

Installed over 13 years ago, the original robots, both Kawasaki units, operate between five to seven days a week, three shifts a day in Norgren's Automotive/Truck air-brake fittings section. Loading and unloading brass fittings into a rotary transfer machine, with a six seconds cycle time, has seen the robots in virtually continuous operation for the period of installation. "Generally the robots have been reliable, but, as expected, after 13 years hard labour there have been some joint wear issues," explains Mark Clark, manufacturing engineer at Norgren. "Although Kawasaki recently gave them [the robots] 'a clean bill of health' for another year, ongoing investment by Norgren in the automotive fittings section made this a good replacement opportunity to upgrade interface electronics and remove risks of obsolescence." The new Kawasaki RS robots load and unload brass fittings to two rotary transfer machines, which have been moved to new bays in the plant.The cells are programmed to produce up to 100 variants of fitting produced in batches. Brass stampings enter the cell, randomly positioned, on a conveyor belt. A vision camera over the conveyor belt pick up point, illuminated by a structured light source, provides the robot with co-ordinates to pick the component correctly. The robot has a double gripper and moves to the transfer machine load point, removes a finished machined fitting and loads the un-machined fitting. The complete machine cycle is complete in 6 seconds. "The new robots are quicker – they work well within the machine cycle time and present the part to the machine before its cycle is finished, and that's what we want," continues Mr Clark. "In addition, the old robots had a shorter reach, which meant they needed to be moved, on a slide fixture, away from the transfer machine to facilitate tool setup. This had a potential to introduce inaccuracies and effectively slowed down tool changes – this process isn't necessary now, as the new Kawasaki RS06L has a longer reach. So we now have faster tool changes and zero risk of the robot being out of position. "We've received excellent support from Kawasaki – moving a transfer line is complex and they've worked around us well, when we've been able to make the system available to them."