Robot systems dramatically improved productivity. Depending on part number, weldments that previously required 3 hours to weld manually can be robotically welded in 50 minutes; others that required 5-6 hours to weld manually can be robotically welded in only 90 minutes. System robotically welds areas that are ergonomically difficult for manual welders, such as 1.2-m (4') down into a channel between two plates. Robotic welding improved quality and consistency. Due to part design limitations (torch access), project would have been considered a success if the robots were able to weld 70% of the total weld length. However, robots far exceeded customer’s expectations and are able to access and weld more than 90% of the total weld length.
Project Challenges
- Provide two duplicate systems for processing large, pre-tacked heavy equipment weldments from four part families, with interchangeability to quickly adapt production from one part type to another.
- Provide a compact welding cell that utilizes the minimum floorspace that production and safety concerns allow.
- Provide the most cost-effective solution, giving priority to the most difficult-to-reach sheet-to-bottom plate internal welds, with secondary importance to brackets and other components within the same cavity.
- Robotically weld parts with access that is difficult for manual welders to reach.
- Improve productivity and provide consistent, quality welds.
Motoman Robotics Solution
Motoman Robotics provided two dual-robot systems. Each includes:
- (2) Motoman EA1900N “Expert Arc” welding robots.
- (2) NX100 robot DR2C Controllers.
- (2) Servo tracks with 4.0-m (13.1') L travel.
- (2) Miller 450-Amp Auto-Axcess® weld packages.
- (2) Weld dress-out packages
- Motoman ComArc dual-robot seam-tracking and 200V touchsensing packages.
- (2) Binzel 45-degree torch packages – 600-Amp, water-cooled with water circulators.
- (2) Reamer/sprayer nozzle cleaning stations with wire cutters.
- (2) ToolSight™ comprehensive torch alignment packages.
- MHT-3100 headstock/tailstock positioner with 6,300 kg (13,889.5-lb) maximum load at 90 mm (3.5") offset CG and 5-second, 180-degree rotation. Includes MotoMount™- compliant tool mounting system.
- Operator station on stand-alone pedestal.
- Enable/disable key operated station – fence-mounted in NEMA enclosure on inside of fence. Disable position prevents servo power from being engaged in Teach or Play mode.
- Common equipment base and table.
- Cell guarding that meets ANSI-RIA R15.06-1999 safety standard, including: 2.5-m (8') woven wire perimeter safety fence with one interlocked personnel access gate; (2) interlocked load/unload gates (one at each end of cell); arc flash protection curtains; audible alarm horn; and teach interlock to identify gate as being open.
Fixtures/Tooling Details
The customer was responsible for providing manually clamped fixtures for this project. Details in the fixtures are manually changed out to accommodate four different part families.
Ref: ACS-104