MULTI-CYLINDER INTERNAL COMBUSTION ENGINE, WITH CYLINDERS EQUIPPED WITH INTAKE VALVE VARIABLE ACTUATION SYSTEMS HAVING HYDRAULIC CIRCUITS WHICH CROSS EACH OTHER

An internal-combustion engine has a plurality of cylinders each provided with two intake valves (V1, V2) that are driven by respective pumping pistons (16) operatively associated to the cams (CAM 1, CAM 2, CAM 3, CAM 4) of a camshaft (11), by means of respective hydraulic circuits. The hydraulic circuit associated to each pumping piston (16) and to the respective cam (CAM 1, CAM 2, CAM 3, CAM 4) has its pressure chamber (C) communicating with hydraulic actuators (21) of two intake valves (V1, V2) associated to two different cylinders (CYL 1, CYL 2, CYL 3, CYL 4) of the engine, so that the two intake valves (V1, V2) of each cylinder (CYL 1, CYL 2, CYL 3, CYL 4) are controlled, via two different hydraulic circuits, by cams associated to two different cylinders. Each cam (CAM 1, CAM 2, CAM 3, CAM 4) is configured in such a way as to give rise to a cycle of opening and closing of each of the intake valves of the engine in an angular range of rotation of the crankshaft considerably less than 180° in such a way that, in each operating cycle of a cylinder, only one first intake valve (V1) initially opens and closes while the second intake valve (V2) remains closed, and then the second intake valve (V2) opens and closes while the first intake valve (V1) remains closed.