Timing control for IC engine

摘要

The timing of the camshaft of an IC engine is varied by a linear drive hydraulic ram (1) whose piston rod drives the adjustment. Both sides of the hydraulic piston are connected to the hydraulic pump (7) via non-return valves (11,12). A 3/3 valve (10) connects either side of the hydraulic piston to a return duct to the fluid reservoir or blocks both sides, and can be replaced by two 2/2 valves or other direct action valves.