Motoman Robots Handling and Welding Heavy Vehicle Axle Housings
System is up to 20 percent faster than requirement for 175-part/shift average for mix of heavy and light parts. Achieved 175 part/shift for heavy parts, and 210 parts/shift for light parts. System produces welds with required part penetration that meet visual inspection criteria and CPK requirements
- Weld 18 different part numbers in both runs, with manual changeover between fixture setups.
- Fit-up and part length vary from one manually pre-tacked part to the next. Gap ranges from 0-1.016 mm (0"-0.040"), offset ranges from 0-1.524 mm (0"-0.060"), and part length varies from 0-6.35 mm (0-0.25").
- Achieve minimum of 55% weld penetration near inboard with 100% penetration for last 152.4 mm (6") of each weld on both sides of the part (from transition to end).
- Meet SPC requirements of 1.67 CPK on weld penetration.
- Meet AWS welding criteria for visual inspection.
- Weld a minimum of 175 parts per 7.6-hour shift (2-3 shifts per day). Required rate is an average, assuming a mix of heavy and light parts. Heaviest parts are 7 mm (0.67") thick mild steel weighing up to 107 kg (236 lbs.) each. Light parts are 9 mm (0.35") thick and weigh approximately 36-41 kg (80-90 lbs) each. Each part gets four heavy-deposition welds.
Motoman Robotics Solution
Motoman Robotics provided a flexible material handling and heavy deposition welding system, including:
- Motoman SK150 robot with air-conditioned MRC controller.
- Custom pneumatic end-of-arm tooling (gripper) with five sets of gripper fingers.
- Four Motoman SK6 robots with air-conditioned DR2C MRC controllers. (Two robots per positioner.) MRCs have expanded memory and MARIO boards.
- Four Tough Gun™ 650-amp water-cooled welding packages (one per SK6 robot).
- Four Banner laser height detection units for seam-finding.
- Four Miller Deltaweld™ 652 power sources with Robotic II interfaces.
- Start-up kits, 1/16" solid-core steel wire. Customer will add bulk wire feeders on-site.
- Four Tregaskiss nozzle reamers with anti-spatter sprayers.
- Four Motoman ToolSight® torch alignment packages.
- Two 3,000-lb capacity, heavy-duty Koike-Aronson headstock/tailstock positioners with 1,500-lb capacity per HS/TS (3,000-lb total capacity).
- Custom steel robot risers and base and spanners for positioners and robots.
- 5.2-m (17-ft) over/under palletized conveyor with pneumatic part elevators at both ends. Includes powered chain-driven infeed conveyor and gravity pallet return conveyor with part-present sensors.
- Custom pallet fixtures.
- Custom fixtures on headstock/tailstock positioners with automatic hydraulic clamping.
- Four copper/tungsten alloy welding back-up bars, located by eight pneumatic cylinders.
- Two hydraulic pumps, plus hydraulic intensifiers for welding fixtures.
- Two intermediate part stands and one outfeed stand.
- Allen-Bradley SLC/503 PLC with Remote I/O.
- Allen-Bradley PanelView™ 600 operator interface.
- Integrated safety package, including light curtains and photo eyes at operator load station, arc curtains, elevator guarding, wire safety fence with arc screens and three safety interlocked gates.