Page 33 - MetalForming November 2022

Fabrication: Arc Welding
fabricators to adopt robotic welding.” Faster and more intuitive to pro- gram helps make for an easily adapt- able and productive piece of automa- tion, but when weld quality and repeatability also improve, then you’re on to something, and that’s precisely the case at Haake. “We experience little to no spatter,” Rieker confirms, “and part-to-part results are very consistent. We never have to worry about wasting time manually touching up welds or
wire-brushing to remove spatter. “Overall, we’ve experienced a 20- percent improvement in throughput compared to the older cell,” he adds, “and gained probably at least another 10 percent in overall productivity when you include the improvement
in weld quality.”
As An Example
...Rieker describes an assembly it runs regularly through the robotic arc welding cell: thin-gauge stainless-steel weldments for a wastewater-treatment
application. Here, the robotic arc welder joins a 10-gauge base plate to a 22-gauge wrapper. “Throughput on that job has increased by nearly 20 per- cent,” Rieker says.
One final key to success when it comes to robotic welding in a relatively low-volume, high-mix environment such as Haake’s: quick changeovers, and here Rieker identifies a couple of enablers.
“First, the robot carries a multifunc- tion welding torch that makes the changeover from welding stainless or carbon steel to aluminum quick and simple,” he says. “We don’t have to change out the entire torch, only the gun liner, which takes less than 30 min. Second, we design and build our weld fixtures to use common base plates where possible, with tooling inserts so that each fixture can handle multiple part families. We try to not over-engi- neer the fixtures, so they’re easily mod- ified. Of the 50 or so fixtures we’ve built only 15 or 20 are regularly used.” MF
Among the assemblies regularly roboti- cally welded at Haake is this diffuser used in the wastewater-treatment indus- try. It comprises a base plate, of 10- gauge Type 316 stainless steel; wrapper, of 22-gauge Type 316 stainless; and a casting. The robot deposits a 16-in. weld with a production cycle time of 2.5 min., including loading and unloading. “The fix- ture is a sophisticated design,” says Haake vice president Jay Rieker, “that uses a pneumatic clamp to hold every- thing tight.”
30 MetalForming/November 2022
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