When the geometric compression ratio of an engine body is set to 13:1 or more and the engine body operates in a preset high load region, the effective compression ratio of the engine body is set to 12:1 or more with a difference from the geometric compression ratio being within 2, a gas to be introduced into a combustion chamber is supercharged by a supercharging system, fuel is injected at least in a compression stroke by an injector, and after the fuel injection is finished, an air-fuel mixture in the combustion chamber is ignited by an ignition device before the compression top dead center and is thus burned by flame propagation in the engine body, and then the unburned air-fuel mixture is burned by compression ignition.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.

A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition, a swirl control valve, a sensor and a controller. The controller is configured to execute a first mode module, a second mode module, and a changing module to change an engine mode from a first mode to a second mode in response to a change demand. The changing module outputs signals to the throttle valve and the injector in response to the demand so that an air-fuel ratio of mixture gas becomes a stoichiometric air-fuel ratio, and outputs a signal to the swirl control valve so that an EGR gas amount decreases more than before the demand, and when the EGR gas amount is determined to be decreased to a given amount, the changing module causes the second mode module to start the second mode.

A gasoline compression ignition engine, a vehicle and a method of operating a gasoline compression ignition engine. An inlet air management system includes a membrane-based separator and an exhaust gas recirculation flowpath that cooperate to deliver a nitrogen enriched air stream to the engine to help reduce exhaust gas emissions. The separator segregates the incoming air into the nitrogen enriched air stream as well as an oxygen enriched air stream such that the latter can be used for various engine load conditions, as well as for supplemental air for a cabin or related passenger compartment within a vehicle that is powered by the engine. Significantly, during an increase in engine load not associated with the cold start and warm-up conditions, the nitrogen enriched air supply that is used for the exhaust gas emissions reduction is provided at least partially by the nitrogen enriched air stream from the separator, as well as increasingly by the nitrogen enriched combustion product stream from the exhaust gas recirculation flowpath.

A gasoline compression ignition engine, a vehicle and a method of operating a gasoline compression ignition engine. An inlet air management system includes a membrane-based separator and an exhaust gas recirculation flowpath that cooperate to deliver a nitrogen enriched air stream to the engine to help reduce exhaust gas emissions. The separator segregates the incoming air into the nitrogen enriched air stream as well as an oxygen enriched air stream such that the latter can be used for various engine load conditions, as well as for supplemental air for a cabin or related passenger compartment within a vehicle that is powered by the engine. Significantly, during an increase in engine load not associated with the cold start and warm-up conditions, the nitrogen enriched air supply that is used for the exhaust gas emissions reduction is provided at least partially by the nitrogen enriched air stream from the separator, as well as increasingly by the nitrogen enriched combustion product stream from the exhaust gas recirculation flowpath.

An engine (21) including a main fuel injection valve (79), a pilot fuel injection valve (82), a liquid fuel supply rail pipe (42), and a pilot fuel supply rail pipe (47). The main fuel injection valve (79) supplies liquid fuel from the liquid fuel supply rail pipe (42) to a combustion chamber (110) during combustion in a diffusion combustion system. The pilot fuel injection valve (82) supplies pilot fuel from the pilot fuel supply rail pipe (47) to the combustion chamber (110) in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe (42) is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe (47) is disposed at the side of the imaginary vertical plane (P1) at which the liquid fuel supply rail pipe (42) is disposed.

An engine (100) operable in a premixed combustion system and a diffusion combustion system. The engine (100) includes a main fuel injection valve (79), a pilot fuel injection valve (82), a liquid fuel tank (33), a main fuel supply path (121), a pilot fuel supply path (122), a pilot fuel filter (141), a pilot fuel high-pressure pump (56), a pilot fuel tank (171), and a pilot fuel supply pump (173). The pilot fuel tank (171) stores pilot fuel sent from the pilot fuel high-pressure pump (56) and not injected by the pilot fuel injection valve (82). This pilot fuel is sent to an automatic backwash filter (174) and a pilot fuel filter (141) while not passing through the liquid fuel tank (33).

A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

An opposed-piston engine system equipped for full hybrid compressed-air/combustion includes capacity for storing air compressed by the engine during a combustion mode of operation. The hybrid opposed-piston engine system includes a control mechanization for operating the opposed-piston engine in a combustion mode by provision of fuel, in a compressed-air mode by provision of stored compressed air, and in a combustion mode supplemented by provision of stored compressed air. A method of operating a hybrid vehicle equipped with an opposed-piston engine includes storing air compressed by the engine during a combustion mode of operation and operating in the vehicle a compressed-air mode by provision of stored compressed air.