Roland R4000 Manual page 20

System description
2.4.3 Placement device for the sensor
The decision at which position the sensor should measure along the axis of the weld is very
important. Especially for tubes with a length > 50 cm the twist of the weld can affect the weld
positioning (weld start and weld end have different circumferential positions). For tubes with small
diameter / wall thickness a variation of up to 10° per meter can be observed. on 1m length. In such
cases it is advisable to place the sensor either at the centre of the tube or at the place where the
weld position is considered to be most important.
Important:
When placing the sensor take into account the twist of the weld seam!
Other requirements are:
Stable, good reproducibility of placement
•
path compensation for different tube diameters
•
Soft, shock-and impact-free touchdown on tube surface
•
Availability of compensation of mounting tolerances and tube geometry
•
Availability of lateral displacement of the axis
•
Clear view on sensor
•
Fig. 4: NS9S Application
A stable placement device is considered to be a device which can place the sensor correctly on the
tube with a high degree of reproducibility. Proven solutions are:
a parallel guide that guides the sensor at right angles to the tube surface
•
the entire device can be aligned with the tube admission, to compensate for mounting
•
tolerances
damping elements and air pressure adjuster when using pneumatic cylinders to enable a soft
•
touch down and allow for sideways movement (adaption) during placement and removal of the
sensor.
the adjusting force is approximately the same as the weight of the sensor
•
the sensor is mounted using the supplied rubber buffers, so compensation for deviations in the
•
tube geometry is possible. This includes ovality and banana effect
the rubber buffers are mounted on the two narrow sides
•
the placing device is mounted on a separate axis so that it can be placed on another measuring
•
spot providing the length of the tube allows for this
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ROLAND ELECTRONIC GmbH · Otto-Maurer-Str. 17 · DE 75210 Keltern · Phone +49 (0)7236-9392-0 · Fax +49 (0)7236-9392-33
Weld Seam Detection System R4000 SND40
for Tubes, Cans and Drums
NS9S, mounted with rubber buffers in a tube
rotator
Manual
B0059001 / Rev. 2.3