Variable compression height piston arrangement

An arrangement for controlling the oil feed into a control chamber of a piston with variable compression height, particularly for internal-combustion engines, said control chamber being arranged between an interior piston part coupled to a connecting rod and an exterior piston part that is guided at the interior piston part on the outside, and the oil feed being controlled by a control valve that is inserted into a longitudinal bore of the connecting rod, said control valve having a valve body that can be moved in a valve chamber between a bore portion of the longitudinal bore on the side of the crank pin and a bore portion of the longitudinal bore on the piston side, said valve body closing off the bore portion on the side of the crank pin when resultant forces act in the direction of the crankshaft, wherein the valve body is guided in the bore portion on the piston side and is provided with a flow-through bore that determines the oil inflow volume from the idling operation to the nominal rotational speed, as well as with an additional control bore that is opened only during the starting process for the control of an additional oil inflow volume.