| 摘要 |
An emission control system for an internal combustion engine having an inlet manifold 11, an exhaust manifold 12 and an exhaust system including a catalytic converter 13 has a connection between the exhaust manifold 12 and inlet manifold 11 for recirculating exhaust gases from the exhaust manifold 12 to the inlet manifold 11, a first gas flow control valve 14 controlling flow of exhaust gases from the exhaust manifold 12 to the inlet manifold 11; a connection to the exhaust manifold 12 by which air may be supplied to the exhaust manifold 12, a second gas flow control valve 16 being provided to control flow of air to the exhaust manifold 12 the first and second gas flow control valves 14, 16 each being driven by a fluid pressure differential actuator 60-72; 140-154, a common regulatable pressure source 21 being adapted to selectively drive either the first gas flow control valve 14 or the second gas flew control valve 16. <IMAGE> |
