GB1224168A - Hydraulic actuating systems for internal combustion engine poppet valves - Google Patents

Abstract

1,224,168. I.C. engine valve gear; hydraulic apparatus. BRYCE BERGER Ltd. July 10, 1968 [July 21, 1967], No.33640/67. Headings F1B and F1P. A hydraulic system for actuating a spring-loaded poppet valve 30, e.g. a dual fuel I.C. engine gas inlet valve, includes a valve actuating plunger 22 movable axially within the cylinder 24 by liquid under pressure acting on its inner end. The plunger 22 has a helical groove 35 which co-operates with a spill port 25 in the cylinder 24 to determine the position of the plunger in which the valve 30 is open. The plunger is angularly adjustable in the cylinder by a sleeve 33 and worm wheel 34 in order to vary the stroke of the plunger. The reduced portion 27 of the plunger co-operates with the bore 28 to cushion motion of the plunger under the action of the spring 23. Actuating liquid is supplied to the inner end of the cylinder 24 through the pipe 32 by a cam-actuated piston 11 having helical edges 13A and 13B and driven by the engine. The piston 11 is angularly adjustable relative to a spill port 14 by a rack 37 to determine the instant and the duration of liquid supply to the valve actuating cylinder 24. To prevent cavitation the cylinder 36 may be connected to the chamber 15, communicating with a liquid supply reservoir, through the non- return valve 17, during the return stroke of the plunger 11.