Solution meets project goals and objectives for productivity increase and quality improvement. Robotic system provides consistent welds and quality parts. System is capable of welding 81 pre-tacked parts per shift – approximately 25% more than required 65 parts per shift. Pre-tacking fixture and procedures developed to minimize box distortion during welding.
Project Challenges
- Provide a multi-process system able to weld several models of pre-tacked parts (heavy-walled steel and aluminum boxes). Part dimensions range from 508-1,524 mm L x 330.2-685.8 mm W x 457.2-812.8 mm H (20-60" L x 13-27" W x 18-32" H).
- Increase productivity through welding automation while improving weld quality and appearance.
- Allow welding operators to be redeployed to other operations within the plant, resulting in overall labor savings.
- Achieve estimated cycle time of approximately 65 box assemblies per 7.5-hour shift.
Motoman Robotics Solution
Motoman Robotics provided a modified FabWorld solution, including:
- Motoman HP50-20 extended reach robot with NX100 controller.
- Fronius TPS-4000 weld package (for steel and aluminum welding), including:
- Multi-process, fully synergic microprocessor-controlled inverter pulse power source controller.
- Push-pull water-cooled torch package.
- Motoman TS-2 200V high-speed touch-sensing function.
- Torch reamer/sprayer nozzle cleaning station with pneumatic wire cutter, mounted on accessory stand.
- ToolSight® comprehensive tool control point/torch alignment package.
- MHT-450 headstock/tailstock positioner with 450-kg (992-lb) rated load; 4-second 180-degree rotation; 9.8 rpm headstock speed. Includes MotoMount™ compliant tool mounting system.
- MHT-1500 headstock/tailstock positioner with 3,000-kg (6,615-lb) rated load; 180-degree sweep in 3.32-seconds; 106 rpm headstock speed. Includes MotoMount™ compliant tool mounting system.
- (2) Operator stations (one master, one slave), mounted in NEMA enclosure on stand-alone pedestal; palm buttons for cycle-start activation; ready signal light and alarm indication light; positioner auto/manual switch and manual jog joystick; lock-out key switch; and two-digit thumbwheel selector. Functions include: Job start, Emergency Stop, Hold, Alarm Reset, and Servo Power-up.
- Robotic fixture package.
- Tacking fixture package.
- Common equipment base.
- Customer was responsible for cell guarding.
Fixtures/Tooling Details
Motoman Robotics provided two robotic weld fixturing packages for the MHT-450 and MHT-1500 positioners with adjustable locating details and four pneumatically actuated swing-arm clamps designed to accommodate a range of box sizes. Fixtures have hardened details and are mounted on a spanner frame between the headstock/tailstock faceplates. Manual changeover is required between box sizes. Motoman also provided a tacking fixture package. The tacking fixture is manually adjustable to accommodate different box sizes. A main table base is approximately 24" from the floor. Two manual top clamps and four pneumatic clamps are used to locate parts. Manual changeover is required between box types.
Ref: ACS-070