A hydraulic actuator for a globe valve in an internal combustion engine, which is known from German Patent No. 38 36 725, has a piston connected to the valve shaft and guided in a cylindrical working space, with a spring-loaded arrangement provided at both ends of the piston so that the piston is forced, when rest, into a central position in which the globe valve is partially open.GLOBE VALVE To move the globe valve into an open or closed position, hydraulic pressure can be alternately applied to the piston from a pressure source. Globe ValvesA feed pump serving as the pressure source and a switchable multiway valve are provided for this purpose.

A hydraulic valve controller for a globe valve in an internal combustion engine, which is known from German Patent No. 195 01 495, has a helical compression spring that loads the globe valve in the closing direction as well as hydraulic spring means that can be connected alternately to a pressure source and a pressure sink by a switchable multi-way valve, with these spring means being able to move the globe valve in the opening direction via a stem piston that can move along with the globe valve.

Hydraulic control mechanisms for a gas exchange globe valve in an internal combustion engine are known from German Patent No. 196 21 951 and German Patent No. 196 21 719, in which first spring means loading the valve in the closing direction and second spring means loading the valve in the opening direction via a stem piston are assigned to the globe valve, with these spring means including a series arrangement of one mechanical and one hydraulic spring. The second spring means form a spring arrangement with a progressive total spring characteristic, with the hydraulic spring being prestressed by a force exceeding the maximum force of the helical spring as a function of the opening work of the globe valve. A correspondingly high supply pressure for the control mechanism is provided for this purpose.

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