Patent ID: 6981476
Filing Date: 2006-01-03
Classification: F01L

Abstract:
1. A multi-cylinder internal combustion engine, comprising: at least an intake valve and at least an exhaust valve for each cylinder, each provided with respective spring return means which thrust the valve towards a closed position, to control respective intake and exhaust conduits, at least a camshaft, for actuating the intake valves and the exhaust valves of the engine cylinders by means of respective tappets, in which each intake valve is actuated by the respective tappet, against the action of the aforesaid spring return means, by the interposition of hydraulic means including a pressurized fluid chamber, which is faced by a pumping piston connected to the tappet of the intake valve, said pressurized fluid chamber being able to be connected by means of a solenoid valve with an exhaust channel, in order to uncouple the intake valve from the respective tappet and cause the rapid closure of the valve by effect of the respective spring return means, electronic control means for controlling each solenoid valve in such a way as to vary the time and travel of opening of the respective intake valve as a function of one or more operative parameters of the engine, wherein: both the intake valves and the exhaust valves of the engine are actuated by respective cams carried by a single camshaft of the engine, the exhaust valves of the engine are actuated mechanically by the respective cams of the single camshaft, the intake valves of the engine have the respective pumping pistons actuated by the respective cams of the single camshaft by means of rocker arm members co-operating with said cams of the intake valves, characterized in that pressurized fluid chamber (C) communicates through said solenoid valve (