Abstract:
A hybrid powertrain unit comprises an engine, and a gearbox device with a primary shaft connectable to a shaft of the engine via a clutch. The gearbox device comprises a secondary shaft with an output pinion meshing with a first crown wheel of a differential, the casing of which is rigidly connected to a casing of the gearbox device. An electric machine is configured to function as an electric motor and an electric generator, having a shaft connected by a transmission to a second crown wheel of the differential. In the transmission, arranged between the electric machine shaft and the second crown wheel is an engagement device that can be actuator driven. The electric machine shaft is connected to the engine shaft, on a side opposite to the gearbox device by a belt transmission that controls vehicle auxiliary devices, which are mounted coaxially with respect to the electric machine.
Abstract:
In an engine having an electronically controlled hydraulic system for variable actuation of intake valves, an operating step of refilling, prior to ignition of the engine, is activated to refill a pressure chamber of the system with fluid when, after prolonged engine inactivity, the chamber has been emptied. In this refilling step, fuel supply to the engine is inhibited, and a camshaft is rotationally driven following upon activation of an engine-starting electrical machine. In this way, a pumping member associated to a tappet for actuating an intake valve is used as a pump for drawing fluid into the pressure chamber from an auxiliary fluid tank. During this step, a control valve is opened and closed in synchronism with movement of the pumping member so as to be open when the pumping member advances towards the pressure chamber and closed when the pumping member moves away from the pressure chamber.
Abstract:
A device for selection and engagement of the gears of a gearbox for motor vehicles has a control shaft mounted rotatable and axially movable with respect to the casing. Mounted on the shaft is a hub having an engagement finger for controlling gear engagement devices, which is configured to oscillate in the space between two fingers of a selection mask, which is mounted on the shaft axially movable therewith and is guided with respect to the casing so as not to follow rotation of the shaft and the hub when a gear is engaged. During displacement of the engagement finger towards an extreme position preliminary to the engagement of the reverse gear, the selection mask is forced to move temporarily into a rotated position, wherein it actuates one or more of the selector devices of the forward gears to enable silent engagement of the reverse gear.
Abstract:
A hybrid powertrain unit comprises an internal combustion engine, and a gearbox device with a primary shaft connectable to the a shaft of the engine via a clutch. The gearbox device comprises a secondary shaft with an output pinion meshing with a first crown wheel of a differential, the casing of which is rigidly connected to a casing of the gearbox device. An electric machine is configured to function as an electric motor and an electric generator, having a shaft connected by a transmission to a second crown wheel of the differential. In the transmission, arranged between the electric machine shaft and the second crown wheel of is an engagement device that can be actuator driven. The electric machine shaft is connected to the engine shaft, on a side opposite to the gearbox device by a belt transmission that controls vehicle auxiliary devices, which are mounted coaxially with respect to the electric machine.
Abstract:
An automotive accelerator device comprising an accelerator member movable in response to driver operation, a position sensor associated with the accelerator member to output a position signal indicating an operation degree of the accelerator member, and signal processing means configured to receive the position signal generated by the position sensor and to generate a command for a motor vehicle engine based on the position signal and a characteristic curve of the accelerator device that defines the command for the motor vehicle engine as a function of the position signal; the signal processing means are further configured to: receive signals indicating a current motor vehicle speed and a target motor vehicle speed, and to dynamically adapt the accelerator device characteristic curve based on the current motor vehicle speed with respect to the target motor vehicle speed; wherein dynamically adapting the accelerator device characteristic curve comprises determining lower, intermediate and upper motor vehicle speed ranges based on the target motor vehicle speed and dynamically adapting the accelerator device characteristic curve based on the current motor vehicle speed and the lower, intermediate and upper motor vehicle speed ranges such that for current motor vehicle speeds within the lower motor vehicle speed range, the command is directly proportional to the position signal, via a first proportionality coefficient, for current motor vehicle speeds within the upper motor vehicle speed range, the command is substantially invariant as the position signal varies, and for current motor vehicle speeds within the intermediate motor vehicle speed range, the command is directly proportional to the position signal, via a second proportionality coefficient lower than the first proportionality coefficient.
Abstract:
An electrically actuated valve includes a first working way and a second working way and a poppet configured for providing a seal on a valve seat set hydraulically between the first working way and the second working way. The poppet includes a first operating position, a second operating position, and a third operating position, and is displaceable by an electrical-actuation device. In the first operating position, a passage area for a hydraulic fluid defined between said valve seat and said poppet has a maximum value. In the second operating position, the passage area is partialized and has a value lower than said maximum value. In the third operating position, the poppet is in contact with the valve seat, and the passage area has a substantially zero value, so that the first working way is isolated from the second working way.
Abstract:
An automotive air conditioning system comprising: an air cooling circuit including a compressor, a condenser, an expansion valve and an evaporator, fluidically connected to be flowed, during operation, by a heat transfer fluid, and a blower fan associated with the evaporator and operable to generate an airflow through the evaporator; an air heating circuit including a liquid/air heater configured to be flowed, during operation, by a heat transfer fluid and arranged close to the evaporator to be flowed also by the airflow generated by the blower fan associated with the evaporator, and a flow rate regulation solenoid valve arranged to regulate the flow rate of the heat transfer fluid through the heater; and an electronic control unit configured to receive a measured evaporator air temperature and a set cabin air temperature and to switch an operating condition of the compressor when the measured evaporator air temperature exhibits a given relation with at least one on/off threshold temperature computed, in at least certain operating conditions, based on the set cabin air temperature.
Abstract:
An internal-combustion engine includes a three-way, three-position solenoid valve, having an inlet communicating with a pressurized-fluid chamber and with a hydraulic actuator of an intake valve, and two outlets communicating with an actuator of another intake valve of a cylinder and the exhaust channel. The solenoid valve has a first position, in which the inlet communicates with both outlets, a second position, in which the inlet communicates only with the outlet connected to the actuator of the intake valve and a third position, in which the inlet does not communicate with any of the two outlets. During at least part of an active stroke of a tappet, the solenoid valve is kept in the third position to render the first intake valve active. During the active stroke of the tappet, the solenoid valve is never brought into the second position so that the second intake valve always remains closed.
Abstract:
A gear change device for a motor vehicle has a braking member for stopping a rotation of a primary shaft before engagement of a reverse gear. The braking member includes a lever pivotally mounted on a gearbox about a separate axis with respect to axes of the primary and secondary shafts of the gear change device. The braking lever is controlled by an electrically-driven actuator by a pusher member displaceable by the actuator in a direction substantially tangential with respect to the primary shaft, towards an operative position in which it interposes with a wedge-like action between the braking lever and a fixed abutment wall, so as to press the brake pad against a cooperating part which is connected in rotation with the primary shaft.
Abstract:
A transmission includes a first primary shaft carrying driving gearwheels for odd gears and reverse, a coaxial second primary shaft carrying driving gearwheels for the even gears, and a secondary shaft carrying idle driven gearwheels meshing with the driving gearwheels. The gearbox has a gear shift device having sliding engagement sleeves each arranged to connect a driven gearwheel corresponding to a given gear for rotation with a secondary shaft. Corresponding sliding shift forks cause an engagement sleeve to slide between a neutral and shift positions. A rotary drum has grooves on its cylindrical surface in which a stud slides, and is connected for translation with a respective shift fork in its sliding direction. An actuation unit rotates the drum stepwise among angular positions corresponding to engagement sleeves' predetermined positions. In a first angular position the engagement sleeves simultaneously engage gear reverse.