Things to Consider for Automated Arc Welding

Transcription

1 Things to Consider for Automated Arc Welding NRAWC June Steve Massey

2 Agenda Existing part tolerances and upstream processes Fixturing and access requirements Optional functions Basic maintenance requirements Robotic arc welding personnel

3 Existing Part Tolerances and Upstream Processes

4 Existing Parts and Processes Processes used to prepare parts Machining Stamping Thermal cutting (manual, mechanized, or automatic) Laser High-definition plasma Plasma Oxy-fuel Forming or bending Manual or CNC Cast or forged components Turret punch Consistency is important

5 Existing Parts and Processes What are the tolerances on your components and assemblies? in. or 0.5-in.? Within one wire diameter is usually considered tolerable for robotic gas metal arc welding (GMAW) Bad parts can be ok as long as they are consistently bad

6 Existing Parts and Processes Currently using manual or mechanized welding? Talk to your welders to see where they continually have to do something special to deal with part prep issues Identify up-stream processes that could present a problem for automation Welders automatically adapt Robots do not DO NOT look at robots to fix your welding problems It will only make them worse If a person cannot handle it, a robot certainly cannot

7 Fixturing and Access Requirements

8 Fixturing and Access Fixturing (or tooling) will be a considerable portion of the cost for a new robotic welding system Do not underestimate or skimp on this Maximize amount of robotic weld Fixture design may be difficult Robot arm Torch cable Proper torch angle May be able to reach but not with proper angle Tooling details

9 Fixturing and Access High-volume production fixtures Custom designed and built specifically for each application May contain high level of automation Sensors and automatic clamps High-mix low-volume fixtures Flexible tooling Highly manual in application

10 Fixturing and Access Large components Tack fixtures with robotic holding fixtures Ability to carry the required load Courtesy of Wolf Robotics

11 Optional Functions Productivity Improvements or Flexible Enhancements

12 Touch Sensing Automatically generated search routines for complex search patterns Fillet sensor V-Groove detecting Single bevel groove detecting Groove width detecting Courtesy of Miller Welding Automation

13 Multi-Layer Functionality Program only one pass Shift original path for multiple passes Continuous welding in 1GR position Alternate direction for non continuous welding Courtesy of Miller Welding Automation

14 Adaptive Welding Calculated volume adaptive welding Through the arc volume adaptive welding Camera volume adaptive welding Courtesy of Wolf Robotics

15 Adaptive Welding Accounts for variations in groove Proper level of fill based on groove geometry Regulates weave width and travel speed Narrow width requires higher travel speed Wider width requires lower travel speed 3mm 10mm Root gap 3mm 10mm Root gap Courtesy of Miller Welding Automation

16 Offline Programming Minimize production downtime Create new programs while robot is running Modify or create programs at PC workstation instead of teaching pendant Requires calibration for best results Courtesy of Miller Welding Automation

17 Basic Maintenance Requirements

18 Basic Maintenance Tool Center Point (TCP) alignment Scheduled contact tip changes Off joint or arc instability Use proper tools not an 18-in. adjustable wrench See TCP alignment Automatically change torch necks Tool Center Point (TCP) alignment Regular nozzle cleaning Porosity or electrical short between contact tip and nozzle Can be automated Tool Center Point (TCP) alignment

19 Basic Maintenance Keep tooling clean and free of spatter Spatter build up could place parts incorrectly Maintain any air hoses or air connections near welds Flame retardant sheaths Porosity Tool Center Point (TCP) alignment Have a good initial definition and reference location Influences robot path most critical on small diameter circular path Use of automatic in-process software adjustment ok as long as initial reference is defined well Must have ability to recover initial physical alignment Straightened / new torch neck installed New torch installed

20 Robotic Arc Welding Personnel AKA - The most important component

21 Robotic Arc Welding Personnel Buy-in is critical for success Involve people that have to live with the automation early in the procurement process Personnel certification Minimum set of skills Certified Robotic Arc Welding Technician (CRAW-T) AWS D16

22 Robotic Arc Welding Personnel Who are the proper people to select for programmers/operators? CNC machine programmers Video gamers Manual welders Mechanical Engineers CAD Jockeys Computer programmers Mechanized welding operators Maintenance personnel It depends - The welding process is the hard part!!!

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