There is no better way to resolve a problem than by eliminating it entirely. At least that’s how KTH Parts Industries Inc. (St. Paris, OH) regarded its decision to automate a manual equipment changeover process for its robotic welding cells.
KTH selected GA2 utility couplers from ATI Industrial Automation (Apex, NC), to accomplish the feat. Specifically, the new automatic coupling of air and electricity utilities to the cells eliminated roughly 65 hours per year of downtime per line, reduced the total cost of operations, and increased equipment utilization and productivity.
KTH Parts Industries, a global Tier 1 automotive supplier for underbody structural parts, has more than 1100 engineering and manufacturing associates involved with the many phases of automotive parts manufacturing including, product development, product analysis, product formability, prototyping, production stamping, forming, robotic welding, assembly, and parts shipment.
One of KTH’s core competencies is the design and implementation of flexible welding lines for automotive underbody components. Its welding lines use complex fixtures, or jigs, to hold the components in place while a robot welds them together. Each automobile model requires a different jig, which leads to many equipment changeovers in the plant.
To increase flexibility and optimize limited manufacturing floor space, KTH created a dual-sided workcell with a turntable. The objective of this design was to keep the robot active and reduce setup time. Parts are loaded into the jig on one side of the turntable while the robot welds parts together on the other.
Before the installation of ATI’s GA2 utility couplers, KTH relied on manual labor to connect and disconnect cables, and load the jigs onto the turntables. Multiply this by one to two changeovers per line per shift, and you have a staggering amount of human-machine interaction in the process.
Dave Reed, a project leader in KTH’s weld department, had this take on the old process: “Before we started using the ATI utility couplers, we had an air line and a manifold, and needed to plug them together with tie-downs. On the electrical side, we had to mate the 40-pin disconnects by manually twisting them together. This process was repeated many times for each jig change.”
According to KTH, the physical labor demands of the old process were very high, and, of course, any time an associate entered the workcell, there was an inherent risk. Under these conditions, the high frequency of cable failure wasn’t a surprise. Coupling and uncoupling the cables with inconsistent force and torque created excessive wear. Misalignment of connectors led to damaged pins. Without a dedicated storage space for cables not in use, they were left on the floor or on top of other equipment in the cell.
“We had air lines that were cut and leaking, connectors that were damaged,” said Reed. “Maintenance was called to try to assess the problem, but a lot of the time, it was just a bent pin on a connector that would cost us hours of downtime—roughly 65 hours a year per line.”
In addition to excessive human interaction and equipment failures, the old process was a nightmare for the equipment support group. The group’s section leader, Jonah Strapp, noted, “After changeovers, you would have to mess with something in the cell to get it working again. Downtime means money lost. When that occurs, there is quite a bit of pressure to get the lines running.”
KTH was exceptionally motivated to improve the welding jig changeover to enable a smoother flow of operations, increase the safety of employees, and reduce instances of equipment failure. Matt Myers, staff engineer of KTH’s engineering project group, explained: “During our normal operation day, we try to squeeze as much production out of the line as possible. Every time we do a changeover, we are losing production time, which translates to a large financial negative in our books. Anything we can do to reduce the amount of downtime is insanely critical.”
That’s exactly the point at which adopting ATI’s utility couplers presented an efficient time-saving solution. ATI’s utility couplers are well-suited to KTH’s welding line changeover. They provide power, signal, and pneumatic. ATI’s utility couplers have built-in rotational compliance to provide repeatable coupling in a durable package. Since the design is modular, the utility couplers work with ATI’s extensive family of tool changer utility modules.
Together, the utility couplers and modules service a range of network protocols as well, KTH’s Myers explained. “When it comes to new product design, I can rely on the ATI engineering team to quickly design an electrical or pneumatic product that fits our needs, or reference one of the thousands of products [available] on their website.” For this particular system at KTH, ATI configured a utility coupler and a 32-pin discrete I/O electrical module that was easily integrated into existing lines.
“When we first started trying out the utility coupler, it was apparent right away that it was going to make a big difference. The new couplers are very reliable and hands-free. We don’t have to mess with them. They work every time,” Strapp said.
When asked how KTH chose ATI as their supplier, Myers replied, “Based on our previous customer service relationship, the quick lead times, and our local account manager, it was an easy decision to go with ATI.” KTH is a longtime user of ATI’s robotic tool changer products, so the transition to automatic coupling with ATI’s utility couplers worked well.
Dave Reed confirmed the performance of the ATI GA2 utility coupler: "I’ve changed probably hundreds of these jigs in the last year, and I have never had an issue with the ATI system. You set the jig on there, you hit the button, it presses in, clamps up, your pins are all mated, you have zero tolerance in getting bent pins or broken air lines. It’s pretty much a flawless product. It makes life a lot easier."