Egr control system and apparatus in the supply system of boosted internal combustion engines

The invention concerns a system and a control and adjustment apparatus of exhaust gas recirculation (EGR) in a supply plant of an internal combustion engine (MCI), boosted in terms of temperature and flow rate of the recirculation gases, both in stationary and in transient conditions. According to the invention, the main flow rate of burnt gases is sent to a turbine (4), for the actuation thereof, while a share of exhaust gas, drawn upstream of the turbine, flows through an adjustor valve (6) and is channelled through a heat exchanger (7) ("EGR cooler"), dedicated to gas cooling. This share of cooled exhaust gas is led to a flow deflector (8), wherefrom - depending on the instant operation conditions of the engine (MCI), it is sent - to a Venturi assembly (10), arranged downstream of the compressor (5), to be mixed there with the air coming from the compressor (5) and then conveyed to an intercooler (9), where the gases are further cooled and then sent to a throttle valve (3), which adjusts the supply thereof to the combustion chamber of the engine (MCI), or - directly downstream of the throttle valve (3), where mixing with the air coming from the intercooler device (9) occurs. The EGR control is actuated, through electric actuations of the adjustor valve (6), of the gas deflection means (8) and of the cooling fluid circulation device (13 or 14), of an electronic control system which uses a dedicated microprocessor, independent but cooperating with the electronic system (ECU) for the general control of the engine supply (MCI).