| 摘要 |
<p>An exhaust system is described for an internal combustion engine which comprises a downpipe (54) and at least one branch (32, 36) leading from an individual exhaust port (16) of the engine to the downpipe (54). To avoid overheating of a close coupled catalytic converter (52) in the downpipe (54), the exhaust system is provided with a gas storage (40) reservoir that is also connected to the exhaust port (16). The size of the reservoir (40) and the connection between the reservoir (40) and the exhaust port (16) are such as to catch and to store in the reservoir (40) the major proportion of exhaust gases discharged from the exhaust port during the blowdown phase of each exhaust period when the engine exhaust valve associated with the exhaust port first opens. Exhaust gases stored in the reservoir (40) are cooled by a heat exchanger (42) and returned to the downpipe (54) at a later stage in the engine cycle.</p> |
