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Before divulging the various tests
and procedures undertaken by
Linde, it is important to understand
the values behind this testing facility.
Linde Material Handling places a key
emphasis on 2 main components
to their development programme:
the humanitarian element, involving
the practical knowledge
and skill of its employees;
and the software- based
testing, coinciding with the
electronically controlled trucks.
Both aspects work in tandem,
helping to ensure product
quality remains consistently
high whilst aiding further
development for future models
to roll off the production line.
“Human experience has always
been indispensable,” claims
Hans-Joachim Wenzel, Head
of vehicle testing. This has
now resulted in virtual testing
becoming indispensable, as
software models mean that test
methods can be implemented,
saving both time and money.
The overall development
process for every Linde truck
is a minimum 800 hours of
driving, tried and testing and
evaluating procedures by the
test drivers. This process runs
twice during the development
stage and once again for final approval
before production.
“Driver impressions and assessments
are a crucial addition to our testing
procedures,” commented Wenzel.
Throughout testing, all truck
characteristics are accumulated
and documented so as to aid in
future developments. Performance
development, reliability, optics and
sounds are all evaluated during testing,
allowing for Linde Material Handling
to add further understanding to their
decades of forklift and
warehouse truck
innovations.
Naturally, with such devotion to testing
and development, customers demand
only the highest quality machines
with the reassurance of extended life
cycle. Linde Material Handling aims
to manufacturer each forklift model to
withstand 20,000 hours of operation,
no matter the environment.
Frozen truck
The cold chamber test is one of
the many testing sections within
the complex. The sight of seeing a
frozen forklift emerge from a freezer,
resembling a seen from ‘The day after
tomorrow’ instantly sparks the desire
to learn more to this testing procedure.
Forklift trucks with an internal
combustion engine must be able to
start and function in temperatures
reaching -15ºC. The main challenge
with low temperatures is the poor
viscosity of the hydraulic oil in the
pump, which is fundamental in lifting
the load and in the case of internal
combustion engine trucks is also used
to drive the hydraulic engines. The
setup for this test requires
that a forklift spends at least
12 hours in the cold chamber,
set at -15ºC. The cold starting
capability is also tested at
high altitude, normally over
2500m, which is crucial as
the performance of internal
combustion engines decreases
in thinner air.
With cold temperature testing,
hot temperature testing also
comes into play, as Linde trucks
are expected to perform at
temperatures exceeding 45ºC.
The roller test stand looks to
validate the cooling concept
for the trucks so as to ensure
the suitability for operating at
such extreme temperatures
without resulting in restrictions
or component failures. The
following operating cycle
consists of the truck driving 30
meters at full speed with 80%
of rated load. The truck then
pulls into a bay, lifts the load 2
meters high and lowers the load and
back out of the bay. This procedure
simulates heavy-duty continuous usage
and the cycle is repeated until the
temperature measured on the truck no
longer show a significant increase due
to the cooling capacity.
Such demanding tests continue with
the stability tests in accordance to IS0
22915 which relates to the safety of
industrial trucks, focussing on tipping
stability. The testing formality consists
of four different test scenarios, based
on realistic driving situation which are
translated into static stability tests.
Two out of the four tests focusses on
braking, both with lifting a load and
with a lowered load or standing
on a ramp. The two other tests
are for starting capabilities,
with both a load retrieved
from a shelf and
whilst standing on
an incline without a
load.
43
Logistics Business Magazine | November 2015
TESTING FORKLIFTS