Patent ID: 6978748

Claim:
A hydraulically controlled actuator for actuation of an exhaust-side gas exchange valve of an internal combustion engine, comprising: a cylinder; a control piston that is displaceable within the cylinder and, with piston sides facing away from one another, delimits a first pressure chamber and a second pressure chamber, wherein: the first pressure chamber impinges upon the gas exchange valve in a closing direction, and the second pressure chamber impinges upon the gas exchange valve in an opening direction; at least one spring element capable of being brought into a preloaded state by the control piston moving in the closing direction of the gas exchange valve, a stored potential energy of the at least one spring element being capable of accelerating the gas exchange valve in the opening direction at least at a beginning of an opening phase; and an entraining element connected to the control piston, wherein: the at least one spring element is connected mechanically in parallel with the control piston and, with the gas exchange valve still in a closed position, accelerates in the opening direction an entraining element, the entraining element striking against a stop of the gas exchange valve; a motion of the control piston in the closing direction can be transferred by the at least one spring element to the gas exchange valve; the at least one spring element is braced under a preload between the entraining element and a shaft end of a first shaft of the gas exchange valve; and with the gas exchange valve completely closed, the at least one spring element can be even further preloaded by a motion of the control piston in the closing direction over a preload travel, the entraining element being configured such that during the motion, the entraining element comes out of engagement with the stop.