Internal combustion engine provided with a valve opening variation system and vehicle equipped with such engine
View Patent ↗The present invention is relative to an internal combustion engine equipped with a plurality of combustion chambers such to allow the variation of the opening of the valves of said chambers by means of an actuator. The engine according to the invention comprises a cylinder head having a supporting axle ( 2 ) on which a plurality of bushings ( 16, 16 ′) is mounted. Said bushings are made integral one another in rotation around the supporting axle by means of a plate ( 12 ) rigidly connected at least in the direction of rotation.
1. An endothermic engine, comprising:
a plurality of combustion chambers each provided with at least one valve and a lever ( 11 ) adapted to cause the opening of said valve;
a camshaft ( 1 ) with a plurality of cams adapted to control said levers;
a cylinder head having a supporting axle ( 2 ) on which a plurality of bushings ( 16 , 16 ′), each of which rotationally supports one of said levers, is rotationally and eccentrically mounted;
an actuator ( 8 ) adapted to cause the rotation of said bushings by a predetermined angle;
wherein said bushings are made integral one another in rotation around said supporting axle by means of a plate ( 12 ) rigidly connected at least in the direction of rotation.
2. An engine according to claim 1 , wherein the rotation of said bushings is such to displace the rotation axis of the levers, varying the clearance in the cam-lever-valve chain, so as to activate or deactivate a portion of the cam, with respect to the opening of the valve.
3. An engine according to claim 2 , wherein said valves are exhaust valves and said cam portion is adapted to cause a supplementary opening of the valve useful for decompression braking.
4. A supercharged engine according to claim 1 .
5. An engine according to claim 1 , wherein several combustion chambers are in line and the actuator is connected to one of said bushings, named main bushing ( 16 ), corresponding to a combustion chamber in a central position in said line.
6. An engine according to claim 1 , wherein the plate has the shape of a cylindrical surface sector, having a symmetry axis coinciding with the rotation axis of the bushings, which is preferably the centreline of the supporting axle.
7. An engine according to claim 1 , wherein said plate comprises a series of overlapping foils ( 14 ) having the shape of a cylindrical surface sector.
8. An engine according to claim 1 , wherein the actuator is positioned outside a cover which closes the engine cylinder head.
9. An engine according to claim 1 , wherein the actuator is of a pneumatic type.
10. A vehicle provided with an engine according to claim 1 .