Page 32 - Metalforming Magazine April 2022

Fabrication: Robotic Welding Cells
Truform maintains a large inventory of weld-fixture decks to serve the robotic welding cells. Quick-change electrical and pneumatic components ease job changeover, with the connections signaling load of the correct program into the robot control.
to partition its robotic welding work according to the type and size of weld- ing wire needed, with 40 percent of the robotic cells dedicated to welding mild steel, for automotive steering members, and 60 percent to stainless steel, for exhaust components.
Focus on Mistake-Proofing
Parts stamped at Truform represent the vast bulk of nourishment for the hungry robotic welding cells, with poka-yoke mistake-proofing and error- proofing mechanisms helping to ensure quality throughout welding operations.
“Poka-yoke is very big for us,” says Beaton. “We try to incorporate poka- yoke mechanisms in our weld tooling as much as possible to enable in- process inspection. Sometimes, heat generated by welding prohibits the use of sensors, so we have employed vision systems on occasion, which have worked well.”
Inhouse Capabilities with Integration Assist
With a fully stocked toolroom and experienced tool designers and builders, Truform fabricates a good portion of its weld fixturing inhouse depending on capacity and workflow, according to Beaton and Crumpton.
“Our tool designers can design the fixtures using 3D CAD programs, then our machine shop uses our wire-EDM, CNC mill and conventional NC machines to build them,” Beaton says. “Our inhouse CMM then verifies every- thing. From there, controls engineers wire up the interfaces and teach the robots to the new fixtures.”
While Truform often integrates new welding fixtures with the robots, the robot cells themselves initially are installed turnkey, already inte- grated with GMAW setups and power supplies.
InMotion LLC, an ABB system-inte- gration partner, has supported design, installation and operation of the weld- ing cells at Truform, dating back to the
The high number of welding cells added at Truform obviously boost pro- ductivity, but so, too, do cell features. For example, the FlexArc configuration allows an operator to load or unload components on one side of the cell while the robot welds on the other. Another productivity aid: the “bulls- eye,” as Beaton calls it.
“This feature calculates the tool cen- terpoint,” he explains. “As someone performs preventive maintenance on the cell—changing tips or nozzles, for example—the welding end point can shift. But using the smart bullseye rou- tine, the robot calculates the correct centerpoint to properly run the job without requiring reteaching. That’s a key feature for us.”
Such features enable more work, and with so many jobs running through the cells, the ability to switch from one to the next efficiently becomes para- mount.
“Just like with our stamping presses, we’ve set up our robotic welding cells with quick changeover,” Beaton says.
To accomplish this, Truform designed custom welding fixtures for each job, with quick-connect/disconnect electri-
cal and pneumatic connections. “When we plug in those connections from the fixture decks,” he explains, “the robot control knows which weld-
ing program to call up.”
And, each robotic welding cell can
accommodate any fixturing.
“We can place any fixture deck on
any robot out there,” says Jody Crump- ton, Truform manufacturing manager. “We don’t run every job on every robot, but for redundancy and contingency, we have that ability.”
Plant-floor operators, too, demon- strate flexibility and contingency capa- bility through common platforms and Truform’s cross-training efforts.
“Our workforce can run any one of our 14 robotic welding cells (the 12 ABB cells and two other cells, one each from OTC Daihen and Yaskawa Motoman),” Beaton says. “The robotic welding cells feature common controls and common tooling decks. And, brought about due to the pandemic, our team is cross-trained to run com- mercial-appliance and assembly oper- ations as well.”
While operators and tooling decks can run on any robot, Truform tends
30 MetalForming/April 2022
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