Pressure amplification device for a hydraulic actuator in an internal combustion engine and engine incorporating such device

摘要

The device (10) has a differential piston cylinder (12) with a differential piston (18) sliding between low pressure chambers (22a, 22b), and a high pressure chamber (28a). A control hydraulic fluid distributor (34) present control positions selectively controlling the refilling or the emptying of the low pressure chambers. A mechanical coupling unit mechanically couples a valve spool (38) and the piston so as to control the commutation of the position of the spool using the piston. An independent claim is also included for a heat engine comprising a hydraulic actuator and a pressure amplification device.