I.c. engine with control of the number of operative cylinders

摘要

The supply of air and fuel to a pair of cylinders is terminated at low load and their exhaust gases are recirculated. The volume of the manifold branch 34 downstream of the connections of the recirculation pipes 20 up to the connection 50 to the manifold branch 36 of the operative cylinders is greater than the displacement volume of one cylinder so that mixing does not take place between the recirculating and freshly produced gases. Heat is transferred to the recirculating gases and their temperature is influenced by a heat exchanger (44, Fig. 2) connected to the engine coolant circuit or a vehicle passenger compartment.