| 摘要 |
<p>An intake system for an internal combustion engine (10) is described having a plurality of cylinders, at least one intake valve (12) per cylinder and an intake port (14) leading to the intake valve (12). The intake system comprises an intake manifold having a plenum (22) connected to ambient air by way of a main throttle (24) and having a plurality of branches (20) each leading from the plenum (22) to an intake port (14) of a respective one of the engine cylinders. A plurality of storage pipes (30) are each connected in parallel with a respective one of the branches (20) of the intake manifold, each storage pipe (30) being connected at one end (34) to the plenum (22) and at the other end (32) to the associated intake port (14). A plurality of exhaust gas recirculation (EGR) pipes (36) are each connected to supply EGR gases from the exhaust system (40) of the engine to a point along the storage pipe (30). The position along the storage pipe (30) of the connection with the EGR pipe (36) is such that when the associated intake valve (12) is closed, EGR gases are drawn by intake manifold vacuum only into the storage pipe (30) so that when the associated intake valve (12) is subsequently opened, air from the branch (20) of the intake manifold and EGR gases stored in the storage pipe (30) enter the cylinder as parallel streams to form within the cylinder stratified regions of air and EGR. Instead of stratifying EGR gases, an alternative embodiment of the invention stratifies gases drawn from a fuel vapour supply.</p> |
