Engine systems

摘要

An engine system includes a valve operable to permit exhaust gas to flow from the exhaust manifold to the air inlet manifold of an engine for the purpose of reducing the noxious gas content of the exhaust. The setting of the valve is dependent upon the amount of fuel supplied to the engine by the pump. A hydraulic signal is generated and this is derived from a supply pump by way of a fixed orifice this pressure being applied to a control valve which regulates the pressure applied to an actuator including a spring loaded piston. A throttle which controls the amount of fuel delivered by the injection pump also forms a further adjustable orifice downstream of the orifice whereby the pressure downstream of the orifice is dependent upon the amount of fuel supplied to the engine.