Patent ID: 9441509
Filing Date: 2016-09-13
CPC Classification: F01L

Claim Text:
1. An internal-combustion engine, comprising, for each cylinder: a combustion chamber; at least two intake ducts and at least one exhaust duct, which open out into said combustion chamber; at least two intake valves and at least one exhaust valve, which are associated to said intake and exhaust ducts and are provided with respective return springs that push them into a closed position; a camshaft for actuating the intake valves, by means of respective tappets; wherein each intake valve of the intake valves is controlled by the respective tappet against the action of the return spring by interposition of hydraulic means including a pressurized-fluid chamber facing a pumping plunger connected to the tappet of the valve, said pressurized-fluid chamber being designed to communicate with the chamber of a hydraulic actuator associated to each intake valve of the intake valves; a single solenoid valve, associated to the intake valves of each cylinder and designed to set in communication said pressurized-fluid chamber with an exhaust channel in order to decouple the intake valve from the respective tappet and cause fast closing of the intake valves as a result of the respective return springs; and electronic control means, for controlling said solenoid valve so as to vary the instant of opening and/or the instant of closing and the lift of each intake valve of the intake valves as a function of one or more operating parameters of the engine, the solenoid valve associated to each cylinder being a three-way, three-position solenoid valve, comprising: said solenoid valve having the following three operating positions: said electronic control means being programmed for implementing, in one or more given operating conditions of the engine, a mode of control of said solenoid valve, wherein: during at least part of the active stroke of the tappet said electrically actuated valve is kept in said third position so as to render the first intake valve active, whereas, through the entire active stroke of the tappet, the electrically actuated valve is never brought into said second position so that said second intake valve always remains closed.