Electro-hydraulic valve with ball lifting for variable compression ratio engine hydraulic unit

The valve (250) has two balls or shutters (251, 252) operating as a non-return valve when the balls held on seats (253, 254) by springs (255, 256) allow the oil in a stage of a multi-stage pressure amplifier (241) to travel towards a high-pressure circuit of a variable compression ratio engine hydraulic unit and not return from the high-pressure circuit. The balls allow the oil from a low-pressure circuit to enter the stage and not to re-emerge from the low-pressure circuit. Lifting units (260) lift the balls from the seats and allow the oil to enter and leave the stage of the amplifier.