Arrangement for actuating gas-change valves

摘要

A hydraulic system for actuating gas-change valves in internal combustion engines or compressors wherein the output piston associated with each gas-change valve is capable of being moved against the force of a closing spring through a control circuit filled with control fluid by an input piston operable by a cam, with means for venting the control fluid at the highest point of the hydraulic system, and wherein the input cylinder communicates with a system for refilling with control fluid. The means for venting the control fluid are formed as permanent venting means, a variable area restrictor determining the amount of control fluid in the hydraulic system during operation is provided which is located in a discharge circuit, and the cam actuating the output piston is formed with a pre-ramp and a post-ramp.