Motoman Robotics provided a robotic spot welding solution that met or exceeded project goals and objectives. Robot system is able to reach around fixtures to spot weld in tight areas on two different planes. Robot system achieves or is slightly faster than required cycle time of 94 spot welds in 211 seconds for panel assemblies and 56 spot welds in 119 seconds for rail assemblies.
Project Challenges
- Provide a robotic cell to spot weld new panel assemblies and rail assemblies that have spot welds that are very close together in some places.
- Stamped parts made of mild steel approximately 1 mm (0.040") thick. Panels are approx. 1,470 mm L x 360 mm W (57.9" L x 14.2" W) and rails are approximately 1,090 mm L x 200 mm W (42.9" L x 7.9" W).
- Panel assemblies require 94 spot welds each and rails require 56 each. Many of the spot welds are close together and difficult to access.
- Cycle time to process panel assemblies will be 211 seconds, and cycle time to process rails assemblies will be 119 seconds.
Motoman Robotics Solution
- Motoman ES165N robot with NX100 controller
- Robot base plate
- Medar 3006 integrated weld control system with programming pendant
- Centerline C-type servo gun package
- Pneumatic tip dresser
- MRM2-500TX positioner – AC servo-driven, dual-headstock/tailstock trunnion positioner with 500 kg (1,102.5-lb capacity per side, balanced within 250 kg (551.3 lbs.) Features 3-m (9.8 ft) distance between headstock and tailstock and 4-5 second sweep time
- Fixture package
- Allen-Bradley SLC 5/05 programmable controller package
- MotoHMI
- Common equipment base for robot controller and welder
- Cell guarding package that meets ANSI/RIA 15.06-1999 safety standard, including 2.4-m (8') woven-wire perimeter safety fence, access gate with positive-break safety switch, flash protection curtains, and light curtains at the weld station.
Fixtures/Tooling Details
Motoman Robotics provided four fixtures. One spanner fixture frame is for the panel and rail subassembly fixtures and the other is for the panel and rail final assembly fixtures. The two subassembly fixtures are located on one side of the dual headstock/tailstock trunnion positioner and the two final assembly fixtures are located on the opposite side. The panel assembly fixtures include locating details and sensing for nut plates. Fixtures are pneumatically clamped, and include part-present and clamp-closed sensors.
Ref: ACS-117