| 摘要 |
1485713 Supercharged I C engines; recirculating exhaust gases FRANCE ARMED FORCES MINISTER OF 28 July 1975 [1 Aug 1974] 31575/75 Heading F1B [Also in Division F2] Exhaust gases are recirculated from the downstream end of a combustion chamber 9 to the intakte duct 21 of a compressor 2 driven by a turbine 3 receiving exhaust gases from the combustion chamber. The compressor supplies air to the working chambers 6 of the compression ignition engine 1 and to the chamber 9 which receives exhaust gas from the chambers 6 and fuel from a supply 10. The flow of exhaust gases through the recirculation duct 18 is controlled by a valve 22 which is controlled automatically or by an operator to close the duct when the conditions of air entering the engine after starting permit compression ignition without heating by addition of exhaust gases. A throttle valve 11, e.g. a flap or plug valve, in the combustion chamber air supply passage 15 is operated by a differential piston arrangement 12 to provide a pressure drop in the passage. The valve 22 includes a poppet valve 27 co-operable with a seat 24 and a piston valve 26 controlling bores 20 communicating with the duct 21. A temperature responsive element 30 positions a member 29 connected to the valve rod 31 by a spring-loaded lost-motion connection 28, 32, 33 which permits the rod to move relative to the member. The element responds to the air temperature in the duct 21 or engine coolant temperature and tends decrease the number of bores 20 which are open as the temperature increases. The piston 26 is subject to the exhaust gas pressure and above a predetermined pressure moves relative to the member 29 against the bias of the spring 28. The valve 27 when adjacent its seat has a pressure drop thereacross and it rapidly engages its seat to prevent further exhaust recirculation. The compressor 2 may be supplied by a low-pressure compressor 39 driven by a turbine 40 receiving exhaust gases from the turbine 3. The engine may be a two or four-stroke reciprocating piston engine or a rotary piston engine. |
