Bosch WBE 5210 Instrucciones De Reparacion página 22

en 22 | WBE 5210 | Auto-diagnosis menu
C-3 60
C-4 60
C-5
Unbalance calibration
Fix firmly the cone flange on the shaft and mount firmly
a medium size car wheel in good condition (wide 5.5",
diameter 14") on the flange itself.
Set up carefully the size of the wheel using the respec-
tive pairs of buttons (+/– WIDTH, DISTANCE and DIAME-
TRE) and make a launch with the wheel. At the end of
the launch the display will show the notice "C-3".
Now, before preparing for the launch, set up the sample
weight (for example 60 g) and modify, if necessary, the
value of grams of the weight chosen for the self-cali-
bration wheel using + and – DIAMETRE, while the right
display shows the value.
Put the weight of the value chosen on the internal side
of the wheel and make the launch At the end of the
launch, remove the calibration weight from the internal
side of the wheel and put it on the external side, sym-
metrically opposed (the display shows "C-4" and the
calibration value which has been chosen).
Now, make the launch again; at the end of the launch
you need to turn the wheel manually so that the calibra-
tion weight is in a perpendicular position, (at 6 o'clock
position, at the bottom, under the main shaft). The dis-
play will show "C-5" and the value of the position angle.
Keep the wheel in this position and press SPLIT (which
has both Leds on).
The calibration is automatically memorized perma-
nently.
NOTES FOR THE ASSISTANCE:
It can happen that after the calibration, the machine
works in a correct way but it does not memorize the
parametres permanently. In order to check you must:
+
turn off the machine;
+
wait until 10sec.;
+
turn it on again;
+
check that the gauges acquire the measures of the
circle in a correct way;
+
verify that the machine balances in a perfect way.
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1 695 654 761 2008-10-17
Setting up of the calibration weight
and launch with the weigh inside
Launch with the weigh outside
Adjustment of the angle
7. Auto-diagnosis menu
On every Bosch balancing machine, you can find an
auto-diagnosis menu that you can use during the assist-
ance in order to check the machine very carefully.
7.1 Msr
The first step in the test menu is checking the pick-ups;
this procedure, that will be analysed in details later on,
is fundamental to identify any sensor problem.
BALANCING SYSTEM
The tool that is used to measure the wheel unbalance
has a mechanic system based on a lever at 1°degree.
The piezoelectric sensors which are in the lower part of
the shaft, at its sides, detect vibrations by converting
the strength into electric tension.
Fig. 2: Position of the piezoelectric sensors
TENSIONS
The piezoelectric sensors, according to where they are,
receive a different stress and weight. In fact, the inter-
nal one, in the left side of the shaft, is excited less than
the external one. So we can say that the ratio between
them is 1.6, that is, the tension measured by the exter-
nal pick-up is 1.6 times higher than the tension meas-
ured by the internal pick-up.
Fig. 3: Stress spread on the shaft
PHASE ANGLE
In general, we use the word phase to identify a particu-
lar moment during a periodical phenomenon (in this
case it is the electrical signal generated by the pick-up
during the launch of the wheel). When we consider two
signals (generated by the internal and the external pick-
up), we can say that there is a phase angle between
them which means that there is a difference between
the tensions. For instance, in this picture, if the black
signal represents the tension of the external pick-up
and the red signal represents the tension of the internal
Robert Bosch GmbH