| 摘要 |
The invention relates to an exhaust gas recirculation (EGR) system for controlling EGR flow in an internal combustion engine. The system comprises an EGR passage (39, 40) and an EGR valve (28) in the passage, opening and closing of the EGR valve being controlled by vacuum provided from the engine manifold (30). A vacuum regulator (29) regulates engine manifold vacuum and passes a regulated manifold vacuum to the EGR valve. A vacuum trap (1) is arranged between the vacuum regulator (29) and the EGR valve (28) to trap in the EGR valve a predetermined level of vacuum, the vacuum trap comprising a valve (12, 13) adapted to close when the level of manifold vacuum drops below a predetermined level, and a bleed passage (24, 26) which allows the trapped vacuum to decay. <IMAGE> |
