Motoman Robots Arc Welding Crane Outriggers (Construction Equipment)

Three Motoman HP20 robots equipped with tandem-arc GMAW torches perform heavy-deposition welding on construction crane outrigger beams fixtured on two MHT-3000 headstock/tailstock positioners using hydraulically clamped adjustable-length tooling.

Summary

Flexible robotic solution meets or exceeds project goals and objectives, and can weld all required parts. Motoman system welds parts significantly faster than the 27-minute cycle time requirement. Some parts are welded in 13 minutes. Most parts average 17-18 minutes. Customer was able to bring all out-sourced production back in-house, saving time and money. Robotic tandem-arc GMAW system consistently produces high-quality heavy-deposition welds and enables skilled manual welders to be redeployed elsewhere in the plant.

Project Challenges

Provide flexible robotic system capable of welding 26 different outrigger beam models distributed across three part families. Mild steel parts range from approximately 1,524-3,657.6 mm (5'-12') L, 6.4-19.1 mm (0.25"-0.75") thick and weigh 226.8-771.1 kg (500-1,700 lbs). Each beam requires 7-10 welds, ranging from approximately 50.8-3,048 mm (2"-10') L.
Achieve 27-minute cycle time for all models (one part every 0.45 hours). Depending on model, beams take 3-4 hours to weld manually.
Increase throughput and productivity to enable out-sourced beams to be brought back in-house.
Improve weld quality and consistency.
Allow skilled manual welders to be redeployed to other jobs within the plant.

Motoman Robotics Solution

Motoman Robotics provided a flexible triple HP20 welding system, including:

(3) HP20 robots with individual NX100 controllers.
(3) Robot base risers.
(3) Fronius TimeTwin TPS 5000 digital weld packages.
(3) Fronius Robacta Twin Compact 900-amp water-cooled tandem-arc GMAW torch packages.
(3) Nozzle cleaning stations for tandem-arc torches. Reamer-type with wire cutter and anti-spatter spray.
(6) ComArc (200-V) seam-tracking and touch-sensing packages.
(2) Motoman MHT-3000 headstock/tailstock positioners with 3,000 kg (6,615-lb) rated load. MotoMount™ fixture mounting system included.
Common equipment base for NX100 controllers with table for welding power supplies.
Fixture package – adjustable spanner and hydraulic fixtures that accommodate required range of part lengths and models.
Operator station.
Cell guarding package that complies with ANSI/RIA R15.06-1999 standard, including 2.4-m (8') woven-wire perimeter safety fence; arc flash protection curtains; (4) sliding gates with positive-break safety switches at positioner load/unload station for part flow-through; and three-color status beacon.

Fixtures/Tooling Details

Motoman Robotics provided hydraulic clamping fixtures for the two headstock/tailstock positioners. A large spanner between the HS/TS faceplates is adjustable to accommodate various beam lengths. Two alignment clamps and two swing arms per fixture hold each part for welding. Fixtures include part-present and clamp open/closed sensors.