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Automated Manual Transmission
10
Line Pressure Sensor:
It is fitted directly on the hydraulic unit, is
made up of a sensitive capacitive element
that generates a signal processed by a special
custom circuit located inside the metal body,
and provides the control unit with a voltage
proportional to the pressure read with refer-
ence to the supply voltage of the sensor.
The supply voltage for the control unit is 5 +/-
0.5 V with absorption of about 10 mA. The
maximum pressure value read is about 80
bar.
Clutch Rpm Sensors:
It is fitted on the gearbox input directly on
the gearbox casing. It is an electromagnetic
sensor and supplies the control unit with a
sinusoidal signal whose frequency is propor-
tional to the speed of a pinion mounted on
the main transmission shaft. The winding re-
sistance is 1200 ohm +/- 10% at 20°C. The
gap is between 0.2 and 1 mm, the rotation
(speed) of a gear on the main transmission
shaft is read.
Engagement and Selection Position Sensors:
The sensors which transmit the position of
the gear selection and engagement actuators
to the TCU are Hall effect sensors fitted di-
rectly on the electro hydraulic unit. They are
supplied with 5 V +/- 0.5 V directly by the
control unit.
The voltage response that arrives at the TCU
depends on the sensor rotation and is linked
to the magnetic field variation.
The two sensors of the same type fitted on
the electro hydraulic unit are:
P.S. Gear selection position sensor
P.I. Gear engagement position sensor
CSC Clutch Actuator:
The CSC is a traditional hydraulic cylinder,
coaxial with the gearbox main shaft. Its (an-
nular) piston is in contact with the clutch
diaphragm spring by means of the thrust
bearing. The piston is held in rest position by
the reaction of the diaphragm spring. Conse-
quently, the clutch is normally closed if there
is no pressure from the robot. A position sen-
sor is present.