automotive sector report
Making progress in automotive
Delivery time of more than one year for a forming tool in the automotive sector? This unusual schedule
is only feasible when the tool supplier works closely with the automotive manufacturer, even before
the first prototype crash tests are performed.
BASED in Heiligenstadt, Germany, Rosell
Werkzeugbau & Stanztechnik’s expertise is in
metal stamping. In a project for the Audi Q5,
Rosell, in partnership with customer Griwe
Werkzeug Produktions (a supplier to Audi)
developed a progressive tool for the retainer sill,
which is located under the B-column. The
retainer sill was to be produced using steel with a
tensile strength of 1000 N/mm 2 .
‘Working closely with the customer is an
important part of our tool development’ explains
Franz Rosell, managing director of Rosell
Werkzeugbau & Stanztechnik. ‘Once the order
has been received, we complete a strip layout and
preliminary design for all forming stations and
present the data to our customer’. He explains that
previously such presentations took about an hour:
‘Historically, the customer was presented with a
pile of drawings that were used to detail the
project. It was extremely difficult to present how
the tool would operate and explain the critical
ideas of the tool maker.’
Close to the tool maker
All tool design and manufacture is now
performed using VISI from Vero Software, in
place at Rosell since 2003. The initial tool design is
based on three typical steps:
■ Develop the 2D blank shape from the 3D
model. This is done using VISI Blank, an
integrated solution that provides valuable analysis
of material behaviour during the forming process
such as thinning and wrinkling, allowing
identification of potential problem areas prior to
physical die design. Rosell explains that previously
blank development was calculated using a
collection of tables which often led to errors. .
■ Design the bending/forming stages and the
production of the 3D strip using VISI Progress.
Step by Step unfolding allows the designer to plan
each forming stage by dynamically adjusting
bend angles allowing complete freedom for
unfolding experimentation. Once the forming
stages are complete, it is possible to automatically
generate a 2D strip plan which forms the basis of
the 3D strip. Tools such as automatic blank
alignment and nesting help plan a more efficient
strip and provide the engineer with valuable
information such as material wastage. The 3D
strip can be simulated at any point to validate the
performance of the punching and forming stages.
■ The 3D tool design must be approved by the
customer and it is here that the main benefits
become apparent. Rosell presents the tool in the
form of individual plate components and 3D
details are often adjusted ‘live’ together with the
customer. Standard components such as screws,
dowels, strip lifters and springs are integrated into
the design, and finally the designer uses the 3D
model to automatically generate the 2D views of
individual components.
Design to manufacture
The die plates are pre-milled directly from the 3D
model and then sent for hardening. This allows
the plates to be coated afterwards without
exceeding the tempering temperature of the steel.
Die apertures are machined by EDM, and the
‘white layer’ is subsequently blasted to produce a
clean burr-free finish.
The forming tools are hardened after premilling
with a material oversize allowance and
then hard-milled to size using VISI Machining, a
powerful 3D CAM solution. The old 2D designs
made it very difficult to see whether a form part
would jam during the assembly. Having a 3D
model of the tool assembly allows the engineer to
easily check the relationship between the
individual parts. A VISI viewer has been installed
in the assembly workshop for this purpose. The
tool maker cannot change the data, only
interrogate the model in 3D and extract the
The lower half of the progressive tool
designed using VISI Progress
relevant measurements or create plots if necessary.
Fine-tuning of the tool starts with data
produced using VISI Blank. This is used to drive a
laser to cut a preliminary strip that is then formed
and separated inside the tool. This creates a
prototype component that simulates all cutting,
bending and forming ops. The final component is
scanned using a CMM and quality checked
against the customer’s target model. If any
deviations are detected, the changes are filtered
back through to the 2D blank and a new strip is
cut with the laser and formed until the deviations
are within acceptable tolerances.
Finally, the completed tool is assembled and a
pressing date is arranged with the customer with
the production part again being checked by
CMM. Different moulding presses can generate
different conditions and tolerances in the tool, so
any last minute fine-tuning may take place onsite.
Franz Rosell concludes: ‘It is easy to notice the
progress we have made since switching to VISI
and 3D tool design. We have an excellent
relationship with the software distributor,
Mecadat, and the products have established
themselves as an integral part of our future plans.’
www.vero-software.com
24 MWP july 2009
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