Hydraulic valve system for controlling flow of gas into or out of a variable volume chamber of an internal combustion engine or compressor

Abstract

The present invention relates to a valve system for controlling flow of gas into or out of a variable volume chamber (8) of an internal combustion engine or a compressor. The valve system comprises a gas flow control valve (5) which opens to permit flow of gas into or out of the variable volume chamber (8); a hydraulic actuator (4) connected to the gas flow control valve (5); a pump (1) for pressurizing hydraulic fluid; a reservoir of hydraulic fluid (6); and a control system (2, 3, 21, 22, 23, 24, 25, 26, 27, 28, 29) which controls opening and closing of the gas control valve (5) by controlling flow of hydraulic fluid to the hydraulic actuator (4) from the pump (1) and flow of hydraulic fluid from hydraulic actuator (4) to the reservoir (6). The control system comprises an electrically controlled flow direction control valve (3) which controls direction of flow of hydraulic fluid to the actuator (4) to control whether the hydraulic actuator (4) opens or closes the gas flow control valve (5); and an electrically controlled switching valve (2) which controls whether or not any hydraulic fluid flows to the hydraulic actuator (4) and thereby controls the time of opening and closing of the gas flow control valve(s). The pump (1) is an electrically controlled variable flow rate pump (1) which controls the rate of opening or closing of the gas flow control valve (5) by controlling the rate of flow of hydraulic fluid to the hydraulic actuator. Operation of the pump (1), flow direction control valve (5) and the switching valve (2) is controlling by an electronic controller (21).

Dependencies are inferred from the claim text.