THE SIX-SPEED ELECTRONIC GEARBOX SYSTEM:
A TECHNOLOGY DEDICATED TO DRIVING COMFORT
six-speed electronic gearbox system combines a manual six-speed
transmission with electronically controlled electro-hydraulic actuators.
This system reduces response times and proves optimal control for
faster and more comfortable gear changes.
In addition, the permanent exchange of information with the Electronic
Stability Program (ESP) ensures a speedy response of the gearbox for
perfect safety when the ESP is active.
six-speed electronic gearbox system features electro-hydraulic controls
of the clutch and the gear changes. As a result, there is no clutch
pedal and the gear lever – which remains present – has no mechanical
link with the gearbox.
The gearbox is managed by a control unit
that controls the two actuators: one – the gearbox actuator – ensures
the selection and engagement of the gears, and the other – the clutch
actuator, controls the clutch.
Gear changes are made as follows:
1. The driver requests a gear change:
either directly in manual mode by issuing a gear
change command with the shift paddles or the shift lever,
indirectly in automated mode by depressing the accelerator, the brake
or as a function of the gradient of the road, engine speed, vehicle
speed and grip conditions.
2. The gearbox control unit detects the request
and processes it.
3. The gearbox control unit takes control of the
engine controller and the clutch actuator.
4. Engine torque is reduced and the clutch is opened
progressively to avoid jolting.
5. When the clutch is open, the gearbox control unit
activates the gearbox actuator.
6. The selector fork is disengaged, the new gear is
selected and synchronized, the selector fork is reengaged.
The gearbox control unit progressively closes the clutch and controls
torque increase to complete the gear change without jolts or rebounds.
These steps are performed in rapid sequence to disrupt the power flow
during acceleration or deceleration as briefly and imperceptibly as
possible. When upshifting, between 0.4 and 1.2 seconds are required to
go from step 1 to step 7.
The mechanical part
automated manual gearbox of the electronic gearbox system is based on a
manual 6-speed gearbox specially designed for being automated. It is
characterized by its: