Abstract: A control unit performs a vehicle attitude control to reduce a torque generated by an engine when an increase in a steering angle exceeds a standard increase, and a spark ignition controlled compression ignition combustion in a predetermined operating range. In the spark ignition controlled compression ignition combustion, switching of an air-fuel ratio mode is performed between a first air-fuel ratio mode (?>1) is formed and a second air-fuel ratio mode (in which a mixed gas of ??1) is formed. If the switching of the air-fuel ratio mode is requested without the vehicle attitude control, the control unit allows performing the requested switching of the air-fuel ratio mode. In contrast, if the mode switching is requested in a state where the vehicle attitude control is requested, the control unit disallows switching of the air-fuel ratio mode even when the switching of the air-fuel ratio mode is requested.

Abstract: An engine control method includes a step of setting combustion mode in which a first combustion mode in which a mixed gas is combusted by propagating flame or a second combustion mode in which the mixed gas is combusted by self-ignition is selected, a step of setting air-fuel ratio mode in which a lean first air-fuel ratio mode or a second air-fuel ratio mode equal to or richer than a theoretical air-fuel ratio is selected, a step of setting torque reduction in which a torque reduction amount by which a torque generated by an engine is reduced based on a steer angle of a steering wheel, and a suppressing step in which reducing the torque generated by the engine based on the torque reduction amount set in the step of setting torque reduction is suppressed.

Abstract: An engine control method includes a step of setting combustion mode in which a first combustion mode in which a mixed gas is combusted by propagating flame or a second combustion mode in which the mixed gas is combusted by self-ignition is selected, a step of setting air-fuel ratio mode in which a lean first air-fuel ratio mode or a second air-fuel ratio mode equal to or richer than a theoretical air-fuel ratio is selected, a step of setting torque reduction in which a torque reduction amount by which a torque generated by an engine is reduced based on a steer angle of a steering wheel, and a suppressing step in which reducing the torque generated by the engine based on the torque reduction amount set in the step of setting torque reduction is suppressed.

Abstract: A control unit performs a vehicle attitude control to reduce a torque generated by an engine when an increase in a steering angle exceeds a standard increase, and a spark ignition controlled compression ignition combustion in a predetermined operating range. In the spark ignition controlled compression ignition combustion, switching of an air-fuel ratio mode is performed between a first air-fuel ratio mode (?>1) is formed and a second air-fuel ratio mode (in which a mixed gas of ??1) is formed. If the switching of the air-fuel ratio mode is requested without the vehicle attitude control, the control unit allows performing the requested switching of the air-fuel ratio mode. In contrast, if the mode switching is requested in a state where the vehicle attitude control is requested, the control unit disallows switching of the air-fuel ratio mode even when the switching of the air-fuel ratio mode is requested.

Abstract: A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition plug, a sensor, and a controller. A changing module outputs a signal to the throttle valve so that an air amount increases more than before the change demand, outputs to the injector a signal to increase the fuel amount according to the increase in the air amount so that an air-fuel ratio of the mixture gas becomes a stoichiometric air-fuel ratio or a substantially stoichiometric air-fuel ratio, and performs a torque adjustment so that an increase of the engine torque caused by the increase in the fuel amount is reduced. When the air amount is determined to have reached a given amount, the changing module ends the increasing of the fuel amount and the torque adjustment, and permits that a second mode module starts the second mode.

Abstract: A control system for a compression ignition engine includes a combustion chamber, a throttle valve, an injector, an ignition plug, an EGR system, a sensor device and a controller. The controller includes a first mode module, a second mode module and a changing module configured 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 or a substantially stoichiometric air-fuel ratio, and outputs a signal to the EGR system 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 permits that the second mode module starts the second mode.

Abstract: A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition plug, a sensor, and a controller. A changing module of the controller outputs a signal to the throttle valve so that an air amount increases more than before a demand of changing from a first mode to a second mode, and outputs to the injector a signal to increase a fuel amount according to the air amount increase so that an air-fuel ratio of mixture gas becomes at or substantially at a stoichiometric air-fuel ratio, and outputs to the ignition plug a signal to retard an ignition timing so that an engine torque increase caused by the fuel amount increase is reduced. The changing module reduces the retarding of the ignition timing when the ignition timing is determined to have reached a retard limit.

Abstract: A control system for a compression ignition engine is provided, which includes a sensor and a cylinder count control module which changes between all-cylinder and reduced-cylinder operations when the compression ignition combustion is performed at a given lean air-fuel ratio. The cylinder count control module executes a preparation control to change from the all-cylinder operation to the reduced-cylinder operation when the change is demanded. In the preparation control, the cylinder count control module outputs a signal to a throttle valve to execute an air amount increase processing, outputs a signal to a fuel injection valve to execute a fuel amount increase processing, and outputs a signal to an ignition plug to execute a retard processing. The cylinder count control module ends the fuel amount increase processing and the retard processing when it is determined that an air-fuel ratio is in a given air-fuel ratio state, and starts the reduced-cylinder operation.

Abstract: A control system for a compression ignition engine configured to start compression ignition combustion by igniting mixture gas formed by injecting fuel into combustion chambers is provided, which includes combustion chambers each defined in respective cylinders so that displacements of the combustion chambers change by respective pistons reciprocating, a throttle valve, ignition plugs, injectors, a sensor having measuring parts including an atmospheric-pressure detector configured to detect an atmospheric pressure, and configured to measure parameters related to operation of the engine, and a controller. The controller executes a lean compression ignition combustion control in which compression ignition combustion is performed at a given lean air-fuel ratio higher than a stoichiometric air-fuel ratio.

Abstract: 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.

Abstract: A control device for a compression-ignition (CI) engine in which partial CI combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark ignition followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an engine operating range, is provided, including an EGR (exhaust gas recirculation) controller configured to change an EGR ratio, and a combustion controller configured to control the EGR controller during the partial compression-ignition combustion to switch a combustion mode between first and second modes in which the EGR ratio is higher than the first mode. After the first mode is switched to the second mode, if a condition is satisfied, the combustion controller causes the resumption to the first mode after a given period of time has elapsed from the switching.

Abstract: 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.

Abstract: A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition plug, a sensor, and a controller. A changing module of the controller outputs a signal to the throttle valve so that an air amount increases more than before a demand of changing from a first mode to a second mode, and outputs to the injector a signal to increase a fuel amount according to the air amount increase so that an air-fuel ratio of mixture gas becomes at or substantially at a stoichiometric air-fuel ratio, and outputs to the ignition plug a signal to retard an ignition timing so that an engine torque increase caused by the fuel amount increase is reduced. The changing module reduces the retarding of the ignition timing when the ignition timing is determined to have reached a retard limit.

Abstract: A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition plug, a sensor, and a controller. A changing module outputs a signal to the throttle valve so that an air amount increases more than before the change demand, outputs to the injector a signal to increase the fuel amount according to the increase in the air amount so that an air-fuel ratio of the mixture gas becomes a stoichiometric air-fuel ratio or a substantially stoichiometric air-fuel ratio, and performs a torque adjustment so that an increase of the engine torque caused by the increase in the fuel amount is reduced. When the air amount is determined to have reached a given amount, the changing module ends the increasing of the fuel amount and the torque adjustment, and permits that a second mode module starts the second mode.

Abstract: A control system for a compression ignition engine is provided, which includes a sensor and a cylinder count control module which changes between all-cylinder and reduced-cylinder operations when the compression ignition combustion is performed at a given lean air-fuel ratio. The cylinder count control module executes a preparation control to change from the all-cylinder operation to the reduced-cylinder operation when the change is demanded. In the preparation control, the cylinder count control module outputs a signal to a throttle valve to execute an air amount increase processing, outputs a signal to a fuel injection valve to execute a fuel amount increase processing, and outputs a signal to an ignition plug to execute a retard processing. The cylinder count control module ends the fuel amount increase processing and the retard processing when it is determined that an air-fuel ratio is in a given air-fuel ratio state, and starts the reduced-cylinder operation.

Abstract: A control system for a compression ignition engine configured to start compression ignition combustion by igniting mixture gas formed by injecting fuel into combustion chambers is provided, which includes combustion chambers each defined in respective cylinders so that displacements of the combustion chambers change by respective pistons reciprocating, a throttle valve, ignition plugs, injectors, a sensor having measuring parts including an atmospheric-pressure detector configured to detect an atmospheric pressure, and configured to measure parameters related to operation of the engine, and a controller. The controller executes a lean compression ignition combustion control in which compression ignition combustion is performed at a given lean air-fuel ratio higher than a stoichiometric air-fuel ratio.

Abstract: A control system for a compression ignition engine includes a combustion chamber, a throttle valve, an injector, an ignition plug, an EGR system, a sensor device and a controller. The controller includes a first mode module, a second mode module and a changing module configured 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 or a substantially stoichiometric air-fuel ratio, and outputs a signal to the EGR system 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 permits that the second mode module starts the second mode.

Abstract: A control device for a compression-ignition (CI) engine in which partial CI combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark ignition followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an engine operating range, is provided, including an EGR (exhaust gas recirculation) controller configured to change an EGR ratio, and a combustion controller configured to control the EGR controller during the partial compression-ignition combustion to switch a combustion mode between first and second modes in which the EGR ratio is higher than the first mode. After the first mode is switched to the second mode, if a condition is satisfied, the combustion controller causes the resumption to the first mode after a given period of time has elapsed from the switching.