DEVICE FOR CONTROLLING A CROSS-SECTION OF AN OPENING IN THE COMBUSTION CYLINDER OF AN INTERNAL COMBUSTION ENGINE

摘要

The invention relates to a device for controlling a cross-section of an opening in the combustion cylinder of an internal combustion engine, said device comprising a gas exchange valve which is integrated into the combustion cylinder and an actuator (16) which drives the valve element (15) in a closing and opening movement. In order to reduce the impact speed of the valve closing body of the valve element on the valve seat during the closing movement of the valve element, a valve brake (50) acts during the final closing course of the valve element. Said valve brake comprises a hydraulic damping element (31) having a fluid displacement volume which flows over a cross-section of a throttling orifice (35), and a control unit (49) for controlling said cross-section according to the viscosity of the displacement volume.