Patent ID: 9376966
Filing Date: 2016-06-28
CPC Classification: F02B,F02D

Claim Text:
1. A method of controlling a compression ratio of a variable compression ratio engine, the method comprising: measuring an angular position of a crankshaft of the engine; opening at least one electrovalve configured and positioned to open or close at least one hydraulic fluid duct extending between a top chamber above a jack piston connected to a control rack and a bottom chamber below the jack piston to reduce the compression ratio of the engine only when a measured angular position of the crankshaft coincides with a force being applied to the control rack which urges the control rack to move in a direction that reduces the compression ratio of the engine; opening the at least one electrovalve to increase the compression ratio of the engine only when a measured angular position of the crankshaft coincides with a force being applied to the control rack which urges the control rack to move in a direction that increases the compression ratio of the engine; and repeating at least one of opening the at least one electrovalve only when a measured angular position of the crankshaft coincides with a force being applied to the control rack which urges the control rack to move in the direction that reduces the compression ratio of the engine and opening the at least one electrovalve only when a measured angular position of the crankshaft coincides with a force being applied to the control rack which urges the control rack to move in the direction that increases the compression ratio of the engine until a position of the control rack corresponds to a required compression ratio of the engine.