C.r.f. Societa Consortile Per Azioni

Sara Sottano

Marco Garabello

Gianluigi Pregnolato

Giancarlo Osella

Attilio Porta

Pierpaolo Antonioli

Cristiana Davide

Massimo Osella

Attillio Porta

An electro-hydraulic control apparatus for a motor-vehicle transmission having at least five forward gears and one reverse gear, including first, second and third shift forks, each movable in at least one engagement position to engage a respective gear, first, second and third hydraulic actuators each arranged to control the movement of a respective shift fork in the respective at least one engagement position, and a slide valve selectively movable into one of at least three operating positions in each of which the slide valve selects a respective hydraulic actuator, wherein a first operating position is an end-of-travel position and corresponds to the selection of the first hydraulic actuator, and wherein a second operating position is also an end-of-travel position and corresponds to the selection of the second hydraulic actuator.

Electro-hydraulic control apparatus for a motor-vehicle transmission with at least five forward gears and one reverse gear

The control apparatus comprises, in its version intended for a double-clutch transmission, first, second and third shift forks each movable between first and second engagement positions to engage a respective gear, of which the first shift fork is able to engage at least the first gear and the second shift fork is able to engage at least the second gear, first, second and third double-acting hydraulic actuators arranged to control each the movement of a respective shift fork between the first and second engagement position, of which the first hydraulic actuator is associated to the first shift fork and the second hydraulic actuator is associated to the second shift fork, a slide valve selectively movable into one of at least three operating positions in each of which the slide valve selects a respective hydraulic actuator, and first and second gear shift solenoid valves for controlling the supply of fluid to the hydraulic actuator each time selected by the slide valve or the connection of that actuator to a tank. The first shift fork is moved into the engagement position of the first gear upon energization of the first gear shift solenoid valve, whereas the second shift fork is moved into the engagement position of the second gear upon energization of the second gear shift solenoid valve.

Electro-hydraulic control apparatus for a motor vehicle transmission with at least five forward gears and one reverse gear

The control apparatus comprises, in its version intended for a double-clutch transmission with six or seven forward gears and one reverse gear, a first shift fork for engaging the first gear or the third gear, respectively, a second shift fork for engaging the reverse gear or the fifth gear, respectively, a first hydraulic actuator arranged to control the movement of the first shift fork, a second hydraulic actuator arranged to control the movement of the second shift fork, a selection slide valve which can be moved into a first operating position in which the first hydraulic actuator is selected and a second operating position in which the second hydraulic actuator is selected, a pilot solenoid valve for controlling the movement of the slide valve between the first and second operating positions, and first and second gear shift solenoid valves for controlling the supply of fluid to the hydraulic actuator each time selected by the slide valve or the connection of said actuator with a tank. The slide valve is configured in such a manner that the first and second operating positions are end-of-travel positions, wherein the first operating position is a rest position, in which the pilot solenoid valve does not generate any hydraulic pilot control signal and the slide valve is held by resilient means against a first mechanical stop, and wherein the second operating position is a maximum-control position, in which the pilot solenoid valve generates a hydraulic control signal such that the slide valve is brought against a second mechanical stop opposite to the first one.

The gearbox comprises an engagement sleeve movable between a neutral position and one engagement position for engagement of one given gear, and a shift fork operatively connected to the engagement sleeve for controlling the movement thereof between the neutral position and the engagement position. The shift fork is slidably mounted on a stationary support rod, which is provided with a pair of bushes defining a first axial abutment surface for stopping the movement of the shift fork in the direction from the neutral position to the engagement position and a second axial abutment surface for stopping the movement of the shift fork in the direction from the engagement position to the neutral position. The neutral position of the shift fork is axially spaced from the second axial abutment surface.

Motor-vehicle gearbox

A method of assessing operation of a common-rail injection system of an internal combustion engine; the injection system having a number of injectors, a high-pressure circuit supplying high-pressure fuel to the injectors, and a low-pressure circuit supplying fuel to the high-pressure circuit; and the method including the steps of hydraulically isolating the high-pressure circuit from the low-pressure circuit and the engine; and assessing operation of the injection system as a function of the fuel pressure drop in the high-pressure circuit.

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Orbassano, Italy

Sara Sottano