TPT July 2008

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J uly 2008 26
Technology Update
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AWS Schäfer Technologie, Germany,
manufactures equipment for pipe forming
and plate forming from complete solutions
to single machines. The company’s hydro-
static pipe lining and calibration press,
branded HFC 380, is equipped to handle a
pipe length of 12.2m.
In order to calibrate the inner stainless
steel pipe into the outer carbon steel shell,
the inner pipe is initially subject to a high
internal water pressure over its full length.
When contact has been made between the
inner lining and the outer shell pipe, the
water pressure is further increased, until
the inner pipe is forced against the outer
shell in a plastic state. The outer shell is
also subject to an elastic deformation under
such high pressure.
The pipe to be calibrated is placed into
a two piece tool by an overhead crane.
During loading, the bottom tool half travels,
by means of a sliding table, into the loading
position. Once the pipe is loaded, the table
travels back into calibration position. The
upper tool half is lowered by means of
hydraulic cylinders onto the bottom tool
half, so that the pipe is fully enclosed by the
two tool halves. The force to hold both tool
halves closed must be sufficient to press
the longitudinally banana-shaped, oval
pipe, into the die.
Two axial cylinders equipped with extension
rods and sealing heads close the pipe
ends hermetically, the two tool halves are
mechanically interlocked to counteract
the forces created during the calibration
operation. The pipe is filled and flushed
with an emulsion, from a tank reservoir,
until there is no air left in the pipe. The force
transmitted on both ends of the pipe by the
axial cylinders is increased automatically
by the machines control program, in direct
relation to the build up of the internal
pressure within the pipe, ensuring a positive
end seal during the process.
As internal pressure increases, the pipe’s
outer surface gradually makes contact
with the internal contours of the tool.
As soon as full contact is achieved, the
internal pressure is raised to the calculated
calibration pressure. On completion of
calibration the internal pressure is relieved
and the axial cylinders are retracted. At the
same time, the pipe is almost completely
emptied of fluid.
The forming liquid is then filtered and
recycled back to the reservoir tank. The tool
locking system is opened, the upper tool
half moves up and the sliding table with the
bottom tool half, together with the calibrated
pipe, travels to the loading/unloading
position. The calibrated pipe is then ready
to be unloaded by an overhead crane.
To cope with different pipe diameters, the
axial cylinder, sealing heads and tools have
to be changed accordingly. The internal
contours of the tooling have to be changed
out to match the required outside diameter
of the pipe. The company recommends the
use of one basic tool for the proposed pipe
diameter range. Dimensions for the basic
machine range are between 101.6 Ø x
8.65mm and 610.0 Ø x 25.4mm.
AWS Schäfer Technologie GmbH –
Germany
Fax: +49 2739 87003 10
Email:
Website:
High definition measurement of small tubes
Tube and wire shorter than 500mm are concealed in many common objects, such as
precise dental drills made from bent wires, and fuel injector rails in automotive engineering.
The quality control of these parts concerns industrial sectors including automotive,
electronic, household appliance, construction, furniture, and medical engineering.
The inspection of the geometries of these very small, thin tubes and wires is not an easy
task. Typically applied metrology is unable to acquire the elements of each individual
small part, and even a common gauge check often proves to be unfeasible.
Aicon 3D Systems GmbH, Germany, has developed TubeInspect HD as a solution to
this problem. The system is based on the technology used in the company’s TubeInspect
and TubeInspect S optical 3D tube measuring systems. While these systems are
designed to measure tubes of any length, the new TubeInspect HD three-dimensionally
inspects short, thin tube and wire with diameters from 1mm to 10mm.
The system checks geometric features including bends, length of part, and end-to-end
distance, and the measuring field comprises a volume of 450mm x 400mm x 200mm.
Accuracy is provided by eight digital cameras positioned close to the workpiece, each
having a resolution of 2 megapixels, and the system uses a glass reference that is
stable both with respect to shape and temperature.
For the determination of the sheath tolerance, the measuring accuracy accounts for
+0.025mm. Measuring results, displayed on the provided notebook computer, are
available within seconds and are presented in a colour-coded method following a gauge
check, enabling the operator to quickly make a decision about the quality of the parts.
The dimensions of TubeInspect HD are 700mm x 700mm x 900mm, making it suitable
for table-top use, for easy integration into existing production environments.
Aicon 3D Systems GmbH – Germany
Fax: +49 531 58 000 60 • Email: • Website :
Hydrostatic pipe lining and calibration press
 The AWS Schäfer hydrostatic pipe lining and
calibration press  Function events of the machine