joining technologies in automotive industry
TRANSCRIPT
Joining technologies in automotive industry
Some examples of Body In White
joining methods
© Valmet Automotive
Overview Used Joining Technologies in the Automotive field (BiW)
3/7/2016 2 Timo Karhu
Welding
Gluing
Sheetmetal Screwing
Riveting
Clinching
Hybrids
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Welding Most common welding processes in Automotive BiW
3/7/2016 3 Timo Karhu
Resistance Welding Laser Welding Arc Welding
Spot Welding MIG / MAG
CMT
TIG
Laser Welding
Electron Beam Welding
Remote / Scanner Deltaspot
Projection Welding
Stud Welding
Laserhybrid
Hardfacing
Used by VA higher tolerances due to self clamping
Partly used by VA
Seam Welding
Usable for Aluminium
moderate tolerances due to gap filling
Requires small tolerances, expensive clamping
Laser Weldinggun
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Welding – Resistance Welding Aluminium Spot Welding - Deltaspot (Fronius)
• Concept
- Influencing the resistance of the material
by adding a driven metal strip. The strip is
”endless” and is driven after every new
spot welded.
• Advantages
- No aloycreation of welding material on the
welding caps
- Can influence the position of the welding
lense and shape, when different material
strenghts and difficult workpiece
geometries are used
- Endless metal strip, has not to be changed
during production time (except 3-Shift)
- Can influence parameters positively
• Disadvantages
- Higher Invest compared to standart SW
tooling
- Changing Metal Strip more complicated
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Deltaspot
Welding Gun
3-Sheetmetal junction of AlMg3 with 17kA, 700ms, 4kN
(0.3mm,1.0mm & 2.0mm)
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Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec)
• Concept
- Multi-ring domed electrodes
- CSS weld schedules
- Aluminum specific equipment set
• Advantages
- Almost normal type of welding equipments
can be used
- Allow different material strenghts and smal
workpiece geometry variation.
- ”Standardized” type of process
• Disadvantages
- Higher Invest compared to standart SW
tooling
- Needs automated electrode cap dressing
and electode cap changer
- Higher weight of welding gun
3/7/2016 5 Timo Karhu
© Valmet Automotive
Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec)
• Concept
- Multi-ring domed electrodes
- CSS weld schedules
- Aluminum specific equipment set
• Multi-Ring Domed Electrodes
- Standard weld cap dressed with custom
cutting blade
- Multi-Ring texture strains the part surface
to reduce contact resistance
- Domed cap improves robustness to non-
idel welding conditions (i.e. off angle, gaps
between parts)
3/7/2016 6 Timo Karhu
© Valmet Automotive
Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec) Cont.
• Concept
- Multi-ring domed electrodes
- CSS weld schedules
- Aluminum specific equipment set
• CSS Weld Schedules
- Conditioning
• Remove effects of part variance
• Seats caps without melting
- Shaping
• Weld nugget initiation at center of
welding location
- Sising
• Nugget growth at lower current levels
• Improve heat affected zone
3/7/2016 7 Timo Karhu
© Valmet Automotive
Welding – Resistance Welding Aluminium Spot Welding - GM (Hirotec) Cont.
• Concept
- Multi-ring domed electrodes
- CSS weld schedules
- Aluminum specific equipment set
• Equipment Set
- MFDC weld control
• 1200 Amp WTC
- Larger weld transformers
• Weld current to 55 kAmps
- Increased gun stiffness
• Weld forces to 5.4 kN
- Automatic tip dressing
• 40 - 80 welds/dress
- Automatic cap changing
• 30 – 60 dresses/cap
3/7/2016 8 Timo Karhu
© Valmet Automotive
Welding – Resistance Welding Projection Welding
• Concept
- Influencing the resistance of the material
by chaniging geometry.
• Advantages
- Can reach corners and other difficult
geometries through adaption of welding
geometry
- Can influence welding parameters
- Low waste on welding caps
- Multiple weldings at once
- Creation of mixted microstructure possible
- Different material strenghts prossible
• Disadvantages
- Additional process needed (forming
geometry)
- Needs special equipment = higher invest
compared to standart SP 3/7/2016 9 Timo Karhu
Melted material
circulates with ca.
20m/s in the
magentic field
Projection
© Valmet Automotive
Welding – Resistance Welding Seam Welding
• Concept
- Continous resistance welding through
replacing electrodes with copper wheels.
• Advantages
- Continous seams, saving gluing process
- Easy to paint
- Good optical aperience
- Can create spots and continous seams
• Disadvantages
- Aloy creation on the wheels, when using
Aluminium or zinkplated materials
- No easy reaplacement of wheels possible
- Complex process, hard to stabilze
- More sensors needed trough moving
along a defined path
- no small curves possible 3/7/2016 10 Timo Karhu
Seam on a tube
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Welding – Arc Welding TIG Welding (Tungsten Inert Gas)
• Concept
- Creates an arc between non consumable
tungsten electrode and work piece.
Ignition through short circuit or high
frequency voltage.
• Advantages
- Very good optical seams
- Good control of process
- Mainly used for non ferro metals
(Aluminium, Stainless Steel, Copper,
Magnesium)
- Requires accessabilty only from one side
• Disadvantages
- Very slow compared to other arc welding
processes
- Requires skilled labour
- Not easy to automate with e.g. Industrial
robots 3/7/2016 11 Timo Karhu
© Valmet Automotive
Welding – Laser Welding Standard Laser Welding / Soldering
• Concept
- Focussed laser photones heat up the workpiece
and, if used, suplementary material.
• Advantages
- Very fast welding speed (>4,5m/min)
- Same Hardware used for welding and brazing
- Good looking seams
- Top hat optics get energy density more
homogenious
- Workpiece only heats up at the seam
- No strong deformation of workpiece
- Requires accessabilty only from one side
• Disadvantages
- Very high invest, operational costs & maintenance
- Requires high precision from workpiece and
environment
- High effort for safety (Lasercabins, glasses)
- Reflective material needs very high energy
3/7/2016 12 Timo Karhu
Laser brazing of rear door (Audi A3)
Laser welding
© Valmet Automotive
Welding – Laser Welding Laser Soldering – Valmet (Scansonic)
• System description
- Power source Trumpf TruDisk 4002
- Welding optics Scansonic ALO3
- Wire feeding Binzel
- Welding wire Fontargen A202 M EC 1,0
mm (CuSi3Mn)
3/7/2016 13 Timo Karhu
© Valmet Automotive
Welding – LaserWelding Laser Soldering – Valmet (Scansonic)
3/7/2016 14 Timo Karhu
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Welding – Laser Welding Remote / Scanner Welding (Laser)
• Concept
- Laserbeam is positioned with fast mirriors to the workpiece.
• Advantages
- Very fast positioning and welding speed
- Small seams possible (<0.5mm)
- Also used for lasercutting
- Can be used for gap filling by rotation circles / ellipses
- High distance from workpiece
- Can reach difficult areas
- Workpiece only heats up at the seam
- No strong deformation of workpiece
- Requires accessabilty only from one side
• Disadvantages
- Very high invest, operational costs & maintenance
- Requires high precision from workpiece and environment
- High effort for safety (Lasercabins, glasses) 3/7/2016 15 Timo Karhu
Remote welding door
Up to 200 welds / minute
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Welding – Laser Welding Laser Scanner Welding – Valmet (RobScan)
• System description
- Power source, Trumpf TruDisk 4002
- Welding optics, Trumph PFO
- ”Welding on the fly” - operation
- Machine vision for quality inspection,
Hema electronics GmbH VISIR (Daimler
patented)
• Robscan Weld Seam Characteristic
- Robscan welds consists of 4 operations
per seam
• Dimpling (1)
• Deep penetration welding (2)
• Reheating of the seam for heat
conduction measurement
• Final Heat conduction welding (3)
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Deep penetration weld (2)
Heat conduction weld (3)
Dimple (1)
Vaporization
channel
Metal Sheet
© Valmet Automotive
Welding – Laser Welding Laser Scanner Welding – Valmet (RobScan)
3/7/2016 17 Timo Karhu
Dimples
Welding finished
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Welding – Laser Welding Laser Scanner Welding – Valmet (RobScan)
3/7/2016 18 Timo Karhu
© Valmet Automotive
Welding – Hybrid Welding Laserwelding Gun (IPG Photon)
• Concept
- Combination of concept advantages of spotwelding
with laser technology.
• Advantages
- Very fast positioning and welding speed (80mm/s)
- Speed andvantage over spot welding up to 50%
- Small seams possible (<0.5mm)
- Workpiece only heats up at the seam
- No strong deformation of workpiece
- No high requirement in accuracy of workpiece
- No Lasercabin needed
- Can be used on Aluminium
• Disadvantages
- Requires accessabilty from both sides
- Combination with glue is questionable
- high invest, operational costs & maintenance
- Needs flat workpiece geometry
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Classical SW 10,5 sec
Laserweldinggun 5,0 sec
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Gluing General Gluing information
• Concept
• Advantages
- Nearly all kind of materials can be
combined
- Big areas are easier to cover than with
other joining technologies
- Good damping properties
- Lightweight
- No microstructure damage of material
- Sealing
- ”Cold” connection – needs usually curing
• Disadvantages
- Preparation processes needed
- Not as resistend towards temperature
- Aging
- Not testable (destructionfree) 3/7/2016 20 Timo Karhu
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Gluing Application in BIW
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Gluing Application in BIW
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Gluing Application in BIW
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Screwing – Sheetmetal screws FDS – Flow Drill Screw
• Concept
- The friction heat, generated through
high force (600-2000N) and turn
speeds (2000-6000rpm), melts a
hole. After reduction of the rpms a
will then form a screw thread which
is thicker than the original material
• Advantages
- Thicker screw thread than with
normal sheet metal screws
- No chipping
- Fast process
- Accessabilty only from one side
- Can be loosend afterwards
• Disadvantages
- Screw can be tightend again
- can’t be used on visible surfaces 3/7/2016 24 Timo Karhu
© Valmet Automotive
Riveting Piercing & Non Piercing
• Concept
- Riveting using friction and clamping forces
to connect workpieces. Piercing rivets are
used mainly in sheetmetal production as
BiW
• Advantages
- Can combine nearly any material
combinations
- High forces through frictional and clamping
connection
- Cold connection
- Can be easily combined with glue
• Disadvantages
- Slow process compared to welding
- Requires accessibility from both sides
- Contact corrosion between rivet and
material possible 3/7/2016 25 Timo Karhu
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Non Piercing Riveting
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Riv
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Pu
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Piercing Riveting
© Valmet Automotive
Clinching Point form / Flat form
• Concept
- Assembly parts from sheet metal and
formable materials are stacked in the
joining position and fixed. A press ram into
the die and deformes the parts plastically.
• Advantages
- Cool joining technology
- No special treadment of the parts before
or after
- Better surface than rivets
- One side easy to paint
• Disadvantages
- Requires accessabilty from both sides
- Slower than spot welding
- Contact corrosion possible
3/7/2016 26 Timo Karhu
© Valmet Automotive
Hybrid – Clinchriveting Fraunhofer IWU & TOX (Tox patented)
• Concept
- Using a rivet as a stamp for clinching,
which remains in the connection. The used
rivets are piercing or hollow punch rivets
without penetrating the workpieces
• Advantages
- Higher resistance of the connection
- Better combination with glue (no airgaps)
- Better surface quality (no hole)
• Disadvantages
- More complex
- Slow process
3/7/2016 27 Timo Karhu
TOX Clinchriveting
Center Deep
drawing
Flow Rivet de-
.formation
IWU Clinchriveting
Anvil replaces the matrix
© Valmet Automotive
Hybrid – Aluminium Weldbrazing In Development - patented by VW
• Concept
- Joining Aluminium and form hardned
steel (22MnB5) with a spotwelding
method. Creating CMT suplementary
material depots on the steel before to
perform a welding and brazing process
at once.
• Advantages
- Combination of most important actual
materials in BiW through a fast and well
known process
- Nearly no change in production
equipment
- Can be combined with gluing
• Disadvantages
- Addittional processes needed to create
solder depots
- Aluminium alloys to welding gun
electrodes and needs more ”cleaning”
(polishing, milling, scraping)
3/7/2016 28 Timo Karhu
22MnB5
AlMg3
Depot
Spotwelding
electrodes
Weakest spot = AlMg3 Structure
Soldered / brazed
connection
Welded
connection
© Valmet Automotive
Hybrid – Rivet Welding In Development - patented by VW
• Concept
- Spotwelding a rivet like metal pin to the
carrier material and clamping the inner
surface material
• Advantages
- Combination of different materials
- Ideal for composite and lightweight design
- Very good surface on the carrier material
- Can be combined with glueing
• Disadvantages
- Addittional processes needed for holes
- Addtional parts needed (rivets)
- Contact corrision not solved
- Needs accessabilty from 2 sides
3/7/2016 29 Timo Karhu
Carrier
material
Inner
surface
Rivet
Spotwelding
electrodes
Rivet
© Valmet Automotive 30
Thank you
for your attention!