Patent ID: 7475659
Filing Date: 2009-01-13
Classification: F01L,Y10T

Abstract:
1. A device for controlling valve movements in an internal combustion engine, the device comprising at least one inlet valve and at least one exhaust valve for controlling a connection between a combustion chamber in a cylinder and an intake system or an exhaust system, respectively, a rotating camshaft having a cam curve, the cam curve comprising a rising ramp and a falling ramp, the camshaft being adapted to interact, via a rocker arm, with a valve mechanism for operating the inlet or exhaust valve by means of a valve spring, the valve mechanism comprising a timing gear which allows a return movement of the valve mechanism to be controlled during a closing phase of the inlet valve or exhaust valve, independently of the falling ramp of the cam curve, and in which the timing gear is designed so that closure of the valve can be retarded for an adjustable time interval by means of a hydraulically adjustable force counteracting a closing force of the valve spring, and the rocker arm and the valve mechanism are separated during the period of retardation, so that there is no interchange of force between them, and a resilient element arranged between the rocker arm and a fixed point on the internal combustion engine in a way that the rocker arm continuously follows the cam curve as the camshaft rotates and the valve spring force is adjusted to a moving mass of the valve mechanism and to a force counteracting the valve closure, and the force exerted by the resilient element is adjusted to a mass of the rocker arm.