Systems and methods for controlling fuelling of dual fuel internal combustion engines are disclosed. The control techniques maximize the substitution rate of gaseous fuel for the liquid fuel by determining a target fuelling amount for the liquid fuel and then regulating an actual fuelling amount of the liquid fuel in response to engine speed and power variations and by modulating the flow rate of the gaseous fuel to the engine.

A control device for an engine is provided, which includes a fuel injector attached to the engine, a spark plug disposed to be oriented into a combustion chamber, a swirl control valve provided in an intake passage, and a controller connected to the fuel injector, the spark plug, and the swirl control valve and configured to control the fuel injector, the spark plug, and the swirl control valve. The swirl control valve closes in a given operating state of the engine. The fuel injector injects fuel after the swirl control valve is closed, between intake stroke and an intermediate stage of compression stroke. The fuel injector injects the fuel after the first fuel injection. The spark plug performs the ignition after the second fuel injection so that the mixture gas starts combustion by flame propagation and then unburned mixture gas self-ignites.

A control system for a compression-ignition engine is provided, which includes an engine having a combustion chamber, an injector, a spark plug, a swirl valve provided to an intake passage of the engine, and a controller connected to the injector, the spark plug, and the swirl valve to control them. The controller includes a processor configured to execute a swirl adjusting module to control an opening of the swirl valve so as to make the opening of the swirl valve smaller as an engine speed decreases and output a control signal to the injector to inject the fuel after the control of the swirl valve, and a combustion controlling module to output an ignition instruction to the spark plug so as to ignite at a given ignition timing after the EGR ratio adjustment, so that partial compression-ignition combustion is performed.

An engine device of the present invention includes including: an intake manifold configured to supply air into a cylinder; an exhaust manifold configured to output exhaust gas from the cylinder; a gas injector which mixes a gaseous fuel with the air supplied from the intake manifold; and a main fuel injection valve configured to inject a liquid fuel into the cylinder for combustion. At the time of switching from a gas mode in which the gaseous fuel is supplied into the cylinder to a diesel mode in which the liquid fuel is supplied into the cylinder, a supply-start timing of the liquid fuel is delayed relative to a supply-stop timing of the gaseous fuel.

A control apparatus for an engine includes an engine, an EGR system, a spark plug, a controller, and a supercharging system. While a supercharging system is performing supercharging and the EGR system is introducing burned gas into a combustion chamber, in response to a control signal from the controller, the spark plug ignites air-fuel mixture at predetermined timing so that unburned air-fuel mixture combusts by autoignition after the air-fuel mixture starts to combust by the ignition.

A control apparatus for a compression autoignition engine includes an engine, a state quantity setting device, a spark plug, and a controller. After the spark plug ignites air-fuel mixture to start combustion, unburned air-fuel mixture is combusted by autoignition. The controller changes, according to an operation state of the engine, a heat amount ratio that represents an index associated with a ratio of an amount of heat generated by air-fuel mixture being combusted by flame propagation, to a total amount of heat generated by air-fuel mixture in the combustion chamber being combusted.

A control apparatus for an engine includes an engine, a state quantity setting device, a spark plug, and a controller. After the spark plug ignites air-fuel mixture to start combustion, combustion of unburned air-fuel mixture is caused by autoignition. The controller outputs a control signal to the state quantity setting device such that, when a number of revolutions of the engine is high, a temperature in a combustion chamber before start of compression is higher than that when the number of revolutions of the engine is low.

A method for operating an internal combustion engine with multiple cylinders. Each cylinder of the internal combustion engine includes at least one fuel injector, and each fuel injector is activated for opening and closing via a solenoid valve of the respective fuel injector. Structure-borne sound waves emitted by the fuel injectors and/or accelerations caused by the fuel injectors are detected by measurement. The structure-borne sound waves detected by measurement and/or the accelerations detected by measurement are evaluated, and based on the evaluation, characteristics of the fuel injectors are automatically determined.

A control apparatus for an engine includes an engine, an EGR system, a spark plug, a controller, and a supercharging system. While a supercharging system is performing supercharging and the EGR system is introducing burned gas into a combustion chamber, in response to a control signal from the controller, the spark plug ignites air-fuel mixture at predetermined timing so that unburned air-fuel mixture combusts by autoignition after the air-fuel mixture starts to combust by the ignition.

A control device for a compression autoignition engine includes an engine, a state quantity setting device, a spark plug, a controller, and a sensor. The spark plug receives a control signal from the controller and ignites air-fuel mixture at predetermined ignition timing such that the ignited air-fuel mixture is combusted by flame propagation and then unburned air-fuel mixture in a combustion chamber is combusted by autoignition. The controller outputs a control signal to an injector such that preceding injection and succeeding injection are performed in a compression stroke.