Provided flexible system capable of producing all required parts. Easily achieved 2.08-minute cycle time which is 18.75% faster than 2.56-minute requirement. Met or exceeded customer’s quality expectations.
Project Challenges
- Automate welding of three different models of exhaust manifolds. Steel parts weigh approximately 3 kg (6.6 lbs.) each and are approximately 432 mm (17.0") long and 250 mm (10") high. Each subassembly requires eight circumferential welds and two seam welds.
- Achieve production rate of 280,000 assemblies per year, at 4,750 hours per year.
- Robotically tack-weld subassemblies in 1.60 minutes per part with one robot; and then final weld manifold subassembly in 2.56 minutes with one “jigless” UP50/UP6 robot combination.
- Changeover required in less than five minutes.
Motoman Robotics Solution
- Motoman Robotics provided two highly flexible mirror-image workcells. Each includes:
- One UP20 tack-welding robot with XRC 2001 controller (feeding both sides of the cell).
- Two six-axis Motoman UP50 material handling robots with XRC 2001 controllers (one per side of the cell).
- Two six-axis Motoman UP6 welding robots with XRC 2001 controllers (one per side of the cell).
- Five robot base risers.
- Two flat table stations with 904-kg. (2,000-lb) payload capacity, each with operator control station.
- Three ThermalArc welding packages (Customer supplied), including power sources, wire feeders, torches, and water circulators. Motoman universal welding interfaces, and three contact tip change boxes included.
- Two sets of custom end-of-arm tooling for UP50 robots.
- Two reposition stations with part-present sensors.
- Allen-Bradley SLC 5/04 PLC package with PanelView 1000 operator interface.
- Outfeed conveyor package – with a 5.8-meter (19-ft.) table-top steel chain conveyor and a 4.6-meter (15-ft.) table-top steel chain conveyor with end stop. Part-present sensors and light curtain to detect safe off-loading condition included.
- Three common equipment bases.
- Cell guarding package, including wire safety fencing with four access gates and positive break safety switches, arc flash protection curtains, and robot zone rings.
Fixtures/Tooling Details
End-of-arm tooling for UP50 material handling robots consists of custom pneumatic grippers capable of handling one tack-welded manifold assembly for finish welding by one of the UP6 robots. Since this is a “jigless” operation, the UP50 robot in each cell positions parts for welding by the UP6 robot. Motoman Robotics provided tack-welding fixtures for the flat-table positioners and reposition fixtures for manual part reorientation by the operator.
Ref: ACS-048