Renault Modus 1.5 dCi 85 Quickshift

The Quickshift robotized gearbox is essentially a manual transmission modified with a module to support the automatic operation of the clutch and gearshifting.

The system requires control of engine torque output and speed during gearchanging, in order to synchronize clutch operation and optimize the speed of shifting. It is also linked to other technologies such as the fuel-injection system and the electronic control system.

Three main elements control the Quickshift:

• The gearbox computer to control gearchanging. The gearbox computer is connected to the mode and gear selectors, the brake pedal switch and the engine management computer. It can also take into account such factors as the gradient of the road and the driving style of the driver.

• The engine management computer, which, thanks to information supplied by the gearbox computer, correctly adjusts the engine torque output and speed by working through the fuel injection and ignition timing.

• The gearchanging robot which carries out the changing process. It consists of different systems of hydraulic actuators (for releasing and engaging the clutch, and for changing gear) and an electric pump assembly which provides the energy needed for gearchanging.

The Quickshift gearbox allows drivers to select for automatic or manual modes simply by moving the gear lever knob to the left.

In manual mode, gear changes require a simple flick of the joystick type gear lever; a forward flick (+) to change up and a rearward flick (-) to shift down. It is also possible to jump gears. For example, if the driver flicks the lever back three times when travelling in fifth gear, the gearbox will automatically select second gear. This is all done without lifting off the accelerator pedal.

In automatic, six auto-adaptive parameters manages the five-speed transmission.

For example, the “kick down” function triggers instant downshift when the accelerator pedal is floored, while the “brake assistance” function anticipates downshifts under braking to profit from the slowing effects of engine braking and also engages the ideal gear for reacceleration.

Under heavy braking, the box shifts down two gears to increase engine braking and shorten stopping distances.

The principal development with this robotized gearbox is the ability of the driver to override the automatic mode at any time in order to change gears without having to swap modes.

Renault also applies the Quickshift in Twingo and Clio model passenger cars.