REMOTE LASER BEAM WELDING WITH INLINE SEAM TRACKING. BMW Joining Technology – Body-in-White FIZ, 11.02.2014 Dr.-Ing. Florian Oefele Christian Roos
EALA – European Automotive Laser Applications 2014
REMOTE LASER BEAM WELDING FOR THE NEW MINI. CONTENT. Motivation Remote laser beam welding with inline seam tracking Mini door production Summary and outlook
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MOTIVATION. STRATEGIC TECHNOLOGY GOALS AT BMW. Strategic goals at BMW
Transformation in car body production
Lightweight construction and sustainibility
Innovative joining processes and concepts
Innovation in Design
Development of new joining technologies
Flexibility and transformation ability
Support of industrial integration
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MOTIVATION. PRODUCTION TECHNOLOGY OF BMW DOORS.
Conventional door production
Aluminium laser door production Aluminium laser welding
Steel laser door production Steel tactile laser welding
Steel laser door production Steel tactile laser welding and remote laser welding
Remote
Tactile
Brazing
Steel and hemming flange Seite 4
MOTIVATION. CONVENTIONAL REMOTE LASER WELDING OF DOORS. State of the art: RLW in overlap configuration with pre-set gap
Advantages Stabile process with degassing gap No special position accuracy necessary Disadvantages Additional costs for setting the gap
Additional cycle time for setting the gap
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MOTIVATION UND STATE OF THE TECHNOLOGY. RLW IN CAR BODY PRODUCTION. Innovation: RLW of fillet welds Fillet welds allow a stabile zinc degassing and therefore a good weld quality even with zero gap. Fillet weld with zero gap
Lap weld with zero gap
Advantages No additional costs or cycle time for degassing gap Small flanges for lightweight construction and design flexibility Disadvantage High position accuracy necessary Seite 6
REMOTE LASER BEAM WELDING. PROCESS IN DETAIL. Stabile zinc degassing through upper capillary aperture z
Zn
Capillary Melt pool with spatters Solidified melt pool Zn
Loss of weigth by spatters [mg]
yoff
Process window Z275
70
Z100 Z0 DX54
50 30 10 -10 -0,4
0 +0,4 Beam offset yoff [mm] Df = 640 μm, vs = 3 m/min, α = 0°, β = 25°, WS = CR3 Zxx
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REMOTE LASER BEAM WELDING. PRINCIPLES FOR AN INLINE SEAM DETECTION. Light-Section
Grey scale picture for scanner
(Development with SCANSONIC)
(Development with LESSMÜLLER / BLACKBIRD / SCANLAB)
chsheet Upper Lower sheet
Detection of 3 values / picture Robust against process disturbances
Large working distances possible Integrated process visualisation
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REMOTE LASER BEAM WELDING. DEVELOPMENT AND REALIZATION - ROADMAP. 2011 Supplier BMW FIZ BMW plants
2012 Development Testing BBG
Prototype 32 v. SOP
2013 Optimization Integration Building phase Pre-Series
Prototype 20 v. SOP
SoP MINI 11/2013
Initiator, coordinator, testing
Adaption of scanner optic
Complete Development
Development of control technology Development of sensor
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REMOTE LASER BEAM WELDING. SCANNER WITH INLINE SEAM TRACKING. Laser Camera
Illumination
SCANSONIC
RLW-A
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REMOTE LASER BEAM WELDING. SCANNER WITH INLINE SEAM TRACKING. Laser Camera
Illumination
SCANLAB intelliweld 30FCV LESSMÜLLER weldeye remote BLACKBIRD RSU remote (not shown)
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SYSTEM ACHITECTURE. SCANNER WITH INLINE SEAM TRACKING. Lessmueller Properties for seam detection: ( Illumination duration, exposure time, etc. …)
Blackbird Properties for welding /communication: (Process parameter, seam numbers, error handling, etc. …)
Laser
Remote Laser beam welding with inline seam tracking Dr.-Ing. Florian Oefele, Christian Roos - 11.02.2014
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MINI DOOR PRODUCTION. JOINING CONCEPT. Joining proceses Closing plate
Tactile Laser Welding (outer skin with inner door panel)
Inner door panel Remote Laser Welding (Closing plate with inner door panel)
Outer skin Seite 13
MINI DOOR PRODUCTION. LAYOUT OF THE PRODUCTION PROCESS. Spot welding (for Positioning of Closing Plate + Inner Door panel)
Cycle time: 58 sec.
Tool Storage
Process time for Remote Welding: 28 sec.
Remote Welding
Tactile laser welding (Outer Skin)
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MINI DOOR PRODUCTION. MATERIAL AND SEAM CONCEPT. 27 to 31 weld seams / door Closing plate (DX54D Z100 0,8 mm)
1.1 m seam length / door
Inner door panel anel (DX54D Z100 0,8 mm)
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MINI DOOR PRODUCTION. FRONT DOOR. Live Camera
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MINI DOOR PRODUCTION. PROCESS PARAMETERS. Joining geometry Fillet welds with zero gap CR3 Z100 (0,8 mm)
Laser source and optic TRUMPF TruDisc4001 Scanlab INTELLIWELD 30 FCV
Process parameters PL = 1,8 kW vS = 3 m/min D = 800 μm
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MINI DOOR PRODUCTION. CHALLENGES. Accuracy of beam positioning
Clamping
(Tolerances in car-body-production of ± 0,5mm)
(implementing zero gaps)
± 0,5 mm
Seam
Yoff Spanner Clamp
Seam tracking
Stabile process
(variable edge geometry, surfaces and conditions)
(Crossjet, protection glass, exhaustion)
hS
hG Seite 18
SUMMARY AND OUTLOOK. New process and system technology for RLW of fillet weld in car body production was presented.
For the new MINI the process is industrially implemented with an inline seam tracking and correction on basis of grey scale image evaluation. Control of edge geometry and process conditions are crucial for a robuste seam detecion and an accurate beam positioning. About 1 m of RLW seams per door increase its stiffnes and realize a lightweight construction with small flanges. Further development of the sensor system aim to integrate additional functions concerning quality control. The process will be developed for new materials and applications.
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