Abstract: In a Diesel engine with variably actuated valves, the cam controlling each inlet valve is shaped to provoke the opening of the respective inlet valve during the engine's normal exhaust phase and thus realize exhaust gas recirculation within the engine, due to the fact that during the normal exhaust phase, part of the exhaust gas passes from the cylinder into the inlet port, from where it returns to the cylinder during the next induction phase, while part of the exhaust gas that had previously passed into the exhaust port returns to the cylinder during the induction phase due to the additional opening of the exhaust valve, in consequence of which the exhaust gas charges that return to the cylinder are subjected to further combustion in the next engine cycle.

Abstract: Described herein is an internal-combustion engine provided with an electro-hydraulic device of an improved type for controlling variable actuation of the valves of the engine.

Abstract: Described herein is an internal-combustion engine provided with an electro-hydraulic device of an improved type for controlling variable actuation of the valves of the engine.

Abstract: In a Diesel engine with variably actuated valves, the cam controlling each inlet valve is shaped to provoke the opening of the respective inlet valve during the engine's normal exhaust phase and thus realize exhaust gas recirculation within the engine, due to the fact that during the normal exhaust phase, part of the exhaust gas passes from the cylinder into the inlet port, from where it returns to the cylinder during the next induction phase, while part of the exhaust gas that had previously passed into the exhaust port returns to the cylinder during the said induction phase due to the additional opening of the exhaust valve, in consequence of which the exhaust gas charges that return to the cylinder are subjected to further combustion in the next engine cycle.

Abstract: In an internal combustion engine having a hydraulic system for valve variable actuation and a hydraulic braking device for slowing down the valve during the final portion of its closing travel, this hydraulic braking device is arranged so as to be substantially insensitive to variations in viscosity of the fluid resulting from variations of the temperature.

Abstract: A multi-cylinder Diesel engine, for trucks, particularly of the type supercharged by a turbo-supercharger actuated by the exhaust gases, is provided with a variable valve actuation system for actuating the intake and exhaust valves, which, in combination with a specific geometry of the cams driving the valves, provides the possibility of a plurality of different modes of operation of the engine which can be selected according to the conditions of operation of the engine and including, in addition to the regular mode of operation, at least one mode of operation of the engine as a brake.

Abstract: An internal combustion engine having a hydraulic system for valve variable actuation and a hydraulic braking device for braking the valve in the final stage of its closing travel. A passage is provided for excluding the above mentioned braking when the engine is in operative conditions in which the fluid used in the device has a viscosity greater than a predetermined value.

Abstract: A variable valve actuating system for an internal combustion engine includes an auxiliary pressure accumulator having a one-way type of operation, provided with pawl-like stop means to hold a piston at a position reached due to an increase of pressure within the chamber of the accumulators, against the action of return spring means. When the engine is started, the stop means are deactivated.

Abstract: An internal combustion engine has two intake valves for each cylinder which can be uncoupled from the respective tappets by drawing fluid under pressure out of a chamber interposed between each tappet and the respective valve. To each engine cylinder there are associated two intake valves, one of which is actuated only at high speed and high loads of the engine. The engine is deprived of the conventional throttle valve. The two intake conduits associated with each cylinder have different specific shapes.

Abstract: In a Diesel engine with variably actuated valves, the cam controlling each inlet valve is shaped to provoke the opening of the respective inlet valve during the engine's normal exhaust phase and thus realize exhaust gas recirculation within the engine, due to the fact that during the normal exhaust phase, part of the exhaust gas passes from the cylinder into the inlet port, from where it returns to the cylinder during the next induction phase, while part of the exhaust gas that had previously passed into the exhaust port returns to the cylinder during the induction phase due to the additional opening of the exhaust valve, in consequence of which the exhaust gas charges that return to the cylinder are subjected to further combustion in the next engine cycle.