EuroWire July 2015

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News
Technology
July 2015 44
With manufacturers using wire harnesses
in increasingly challenging functional
and environmental conditions, ultrasonic
welding is becoming the favoured
method of assembly, since it produces
welds with high conductivity and tensile
strength. In fact, it is estimated that at
least two-thirds of the cabling used in
today’s cars is ultrasonically welded.
“Wire harnesses are like the central
nervous systems for equipment in a wide
variety of industries, including consumer
electronics and appliances, data and
telecommunications, lighting, medical,
automobile, marine and aerospace,” said
Melissa Alleman, Sonobond Ultrasonics’
vice president.
Ultrasonic welding has become a
popular alternative to other methods
of welding because it uses vibrational
energy to disperse surface oxides and
create galling on wire strands. This forms
a solid-state metallurgical bond with
high conductivity, producing the lowest
resistance weld available.
“Unlike resistance welding that generates
high heat, in ultrasonic welding the
metals do not melt, so there are no
significant changes in the material
properties, and the lower heat means no
external water cooling is needed,” added
Ms Alleman. Also, unlike soldering –
which cannot be used if the temperature
at the weld during use approaches the
melting point of the solder – ultrasonic
welding requires no flux or filler materials.
Plus, ultrasonic welding uses much less
time and energy than its alternatives.
The ultrasonic welding process begins
with a power supply that converts input
line power into high frequency electrical
power and transmits that energy to a
transducer.
The transducer transforms the electrical
energy into vibratory energy, which is
delivered to the welding area as sound
waves, or ultrasonics. When the vibrating,
shear forces of the ultrasonic waves
are directed by the welding tip to the
interface between two metals, which
are held together under clamping force,
internal stresses cause deformation
where the materials are in contact.
A localised increase in temperature and
interfacial slip breaks up oxides and
surface films, permitting metal-to-metal
contact at many points. Continued
vibration causes further deformation of
the points, increasing the contact area
and essentially creating a weld without
melting, and producing a metallurgical
bond with high conductivity and tensile
strength.
The Wedge-Reed system uses a vertical
vibrating reed, driven by a wedge-shaped
coupler and transducer assembly perpen-
dicular to the reed, allowing high clamp
force without bending stress or stalling.
Sonobond’s Dual Head SpliceRiteTM features
welding heads on both sides of the weld
area, enabling it to provide one-pulse
wire splicing of up to 100mm2 in stranded
bare copper wire and tinned wire to about
60mm2. Also available are a Dual Head Spot
Welder, as well as Sonobond’s SonoWeld®
units, which can be custom-tooled to weld
tinned wire to bare or coated terminals.
Every Sonobond welder is equipped with a
microprocessor controller that can program
welds by height, energy or time, and store
and recall up to 250 jobs.
Additionally, all units have heat-treated,
taper-lock tips that are capable of
achieving up to 100,000 welds and that
are easily replaceable without requiring
machine readjustment or calibration.
Sonobond’s equipment also offers
automatic frequency control and overload
protection, and can detect and prevent
wrong-part or no-part activation.
Sonobond Ultrasonics – UK
Website:
New powerful cable feeding systems
Schleuniger has introduced the new
PreFeeder 3300 and PreFeeder 4300 cable
feeding systems. The systems distinguish
themselves through simple design and
ease of use. For easy reel handling and
fast changeovers, all axes are electrically
driven. Both the PreFeeder 3300 and
PreFeeder 4300 use a shaftless design for
easy loading and unloading of reels.
The PreFeeder 3300 is suitable for reels
weighing up to 150kg (330lb) with
a maximum diameter of 600mm (24") while the PreFeeder 4300 can handle reels
weighing up to 400kg (880lb) with a maximum diameter of 900mm (36"). These
powerful machines can increase production rates and economic efficiency.
Schleuniger North America Inc – USA Website:
▲ ▲ The new PreFeeder 4300 cable feeding systems
Ultrasonic welding the favoured method of
assembly