What started over 40 years ago with the rebuilding of tractors for
the forestry industry has now developed into Normet, a
world-leading player in machines for underground use.
Normet Oy develops and produces vehicles and mobile equipment
for the mining and tunnel-building industries. Besides specialist
vehicles for use in underground excavating, explosive charging,
scaling, concrete spraying and transport, the company's programme
also includes the world's first specially designed mine car. To
date, over 7,000 vehicles have been supplied worldwide. The largest
single markets areEuropeand the CIS countries. However, North and
South America, Asia, Africa andAustraliahave all also received
deliveries.
A pallet and workpiece, total weight 7 - 8 tonnes,
is lifted in, positioned and secured in a few
minutes.
The extreme conditions in mines and tunnels are exceedingly
tough on machines. Humidity, corrosive conditions and temperatures
that fluctuate between -20 and +40°Cmean that "life time care"
(LTC) is a vital part of the company's operations.
Normet currently has 450 employees, 350 of these in the 23 000
m2 development and production facility in Iisalmi,
centralFinland. With 12 manual stations and an automatic robot
cell, welding dominates production. Three stations take care of
cutting to tolerances of0.05 mm. There are also shops for painting
and final assembly. A two-shift system is used.
On finishing his university studies two years ago, Janne Korhonen
was appointed as a development engineer. He had then not finished
the thesis he had started at Normet.
Janne Korhonen: "Delphin BIG's impact on production
capacity has exceeded all our expectations."
Normet had capacity problems in its largest milling machine.
This was used for machining, amongst other things, chassis and
booms - hefty workpieces weighing up to a couple of tonnes. As a
rule, these were machined in two separate set-ups. The total
machining time was 5 - 6 hours.
Korhonen's assignment was to evaluate possible ways of
increasing capacity. Was a new machine necessary? Or were there
other solutions?
Janne Korhonen relates: "When I began looking at the machine's
spindle hours, I saw that they werea littleover 50%. This was due
to the long and involved retoolings on the machine table with the
machine at a stop. It certainly didn't seem a good idea to invest
in a new, expensive machine to then have two machines that were
only being half used."
Janne Korhonen wondered whether palletisation of the workpieces
might be a solution. Setting up might then be moved away from the
machine and carried out while the machine processed another
workpiece. Furthermore, investing in a pallet system would only be
a fraction of the cost of a new machine. A cautious calculation
showed that palletised workpieces might increase the machine's
spindle hours by up to 30 percent. However, who had ever heard of a
pallet system for workpieces weighing as much as a couple of
tonnes?
A meticulous investigation was started into what the market had to
offer as regards the palletisation of heavy workpieces. In April,
Janne Korhonen saw System 3R's Delphin BIG at the FinnTec fair
inHelsinki.
Janne Korhonen: "I was impressed by the capacity, the accuracy
and the simple handling - a very user-friendly pallet system." A
simple calculation showed that the entire investment could pay for
itself in eight months. These figures were presented to the
company's senior management and a decision was rapidly reached.
The pallet system was installed in August. It included eight
hydraulic Delphin BIG chucks on the machine table and, weighing 5
tonnes each, two in-house manufactured pallets (4,000 x 2,000 x85
mm). Only three days were needed to prepare the machine table -
i.e. install the eight chucks, fit the stops/robust guides (for
easier loading of the pallets) and mount a cover (to protect
hydraulic lines and for simpler cleaning).
In October, it was clear that the machine's capacity had doubled
from between 20 and 25 chassis a month to 50. Thus, instead of the
expected 30 percent, the capacity increase turned out to be 100
percent! Two other machines are now scheduled for similar
attention.
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