TPT March 2011

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Automotive Tube & Pipe Manufacturing
Officine MTM SpA, Italy, is the manufacturer
of tube mills for the automotive industry.
The company began manufacture of these
mills in 1984, with the first application
being a complete tube mill for tubes in high
tensile carbon steel, with small OD and thick
material.
Since that time several tube mills have
been developed specifically for automotive
products, for carbon steel, stainless steel and
aluminum alloys in different applications.
MTM currently has a comprehensive range
that can satisfy most requirements of tubes for
automotive industry. For carbon steel tubes,
the company offers its expertise with complete
tube mills for seats, shafts, engine supports
and frames. Exhausts are made in aluminized
and galvanized carbon steel as well as in HF
welded stainless steel.
For aluminium radiator and heat
exchangers, MTM has a specific range
of complete solutions for welded and
folded tubes, as well as charging air cooler
sections. The company also has experience
in manufacturing tube mills for hydroforming
applications.
Due to its partnership with Atomat, a
worldwideleaderindesignandmanufacturing
of roll sets for the tube industry, MTM can
offer turnkey plants complying with the
highest quality standard.
Officine MTM SpA – Italy
Fax: +39 041 999611
Email:
Website:
Tube mills developed for automotive products
RSA, a German sawing technology
specialist, has launched the Rasacut XS,
a high-performance circular saw for tube
diameters from 6 to 25mm. The machine
was developed as a response to recent
technological developments in the field of
circular saws that have generally been
aimed at high output of the 10-100mm
diameter range.
The minimisation of variants in the
automotive industry is leading to larger
batches for the production of semi-finished
products made from tube, hollow sections
and solid bars. However, quality demands
are also increasing. A machine concept
aimed at a wide spectrum of workpieces
can cope only to some extent with demands
made by highly specific parts, eg line systems
in the automotive sector, where extremely
strict requirements are applied concerning
the degree of purity and precision of the
tubes. However, the large quantities allow
comparatively low piece costs.
Multi-cut or bundle cut saws are generally
used for the production of large batches in
the diameter range up to 25mm. However,
aimed at an improvement in quality and
lowering of piece costs, the new RSA
development counts on the single cut. The
fully automatic processing cycle – even for
large fixed lengths of 2,000mm or longer –
presents an essential advantage.
When working with bundle cut saws,
tubes are manually bundled. The workpieces
are counted, fixed with an adhesive tape and
inserted into a prismatic guide that feeds the
tube bundle to the saw. With the Rasacut
XS, tubes are automatically singled and
fed. This method also allows one person to
operate several saws.
The new RSA system is beneficial during
further processing of tubes after cutting.
In case of bundle cut saws, fixed lengths
can fall apart after cutting – the so-called
‘mikado effect’. The feeding of the tubular
sections to another processing step, such
as deburring, requires further logistics –
either an automatic singling machine or the
manual feeding of a magazine.
The Rasacut XS can be modularly
expanded into a processing centre,
combining in one line the processes of
sawing, deburring or facing and chamfering,
checking of lengths, roundness or chamfer,
cleaning and stacking.
RSA claims that the Rasacut XS
achieves in a single cut output values
that are as high as those of multi-cut or
bundle cut saws – and depending on the
dimensional range, even more – due to the
reduction of ancillary times. Material is fed
by means of a gripper with an acceleration
of up to 40m/s². The next tube is fed during
the current sawing process, avoiding a
loss of time during the changeover to the
next stock length.
On the basis of the Rasacut XS output
values, around 150 changeovers to the
next stock length are required per hour
for a tube with 8mm diameter and a fixed
length of 250mm, for a stock length of
the random material of 6,000mm. This
example shows the importance of ancillary
times with regard to the total output. As
an example of output: round tube with a
diameter of 12mm and a wall thickness of
1mm, material E235. For a fixed length of
150mm the output of the saw adds up to
4,014 pieces per hour.
Forward feed and drive of the saw is
effected through servomotors. The saw
blade diameters are between 175 and
200mm, and depending on the material,
HSS, carbide or solid-carbide saw blades
can be used. The specific tuning of the teeth
profiles with the material and workpiece
characteristics of the parts to be cut is done
by RSA.
RSA Entgrat- u. Trenn-Systeme
GmbH & Co KG – Germany
Email:
Website:
RSA Cutting & Deburring Systems Ltd
– UK
Fax: +44 1952 580511
Email:
Website:
Saw specifically designed for small diameters