Abstract: An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

Abstract: An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

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 device for a compression-ignition engine in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of a mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the remaining mixture gas to self-ignite is executed at least within a part of an engine operating range is provided, which includes a detector configured to detect a given parameter that changes as combustion progresses inside the cylinder, an A/F (air-fuel ratio) controller configured to change an air-fuel ratio of air to fuel introduced into the cylinder, and a combustion controller configured to determine combustion stability based on the detected parameter of the detector and control the A/F controller to reduce the air-fuel ratio when it is confirmed that during the partial compression-ignition combustion the combustion stability is low.

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 device for a compression-ignition engine is provided, in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, an EGR (exhaust gas recirculation) controller configured to change an EGR ratio being a ratio of exhaust gas introduced into the cylinder, and a combustion controller configured to control the EGR controller to increase the EGR ratio when a noise index value specified based on the detected parameter of the detector is confirmed to exceed a given threshold during the partial compression-ignition combustion.

Abstract: Intake ports include a second port configured such that a flow rate of flowing gas is adjusted via a swirl control valve. When a surge tank is viewed in a cylinder axis direction, first and second branched passages are connected with a space being interposed therebetween in a cylinder array direction, and are connected to the surge tank on extension lines, each of which extends from an upstream end portion of an independent passage connected to the second port to an opposite side of each cylinder.

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 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 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 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 device for an engine in which partial compression-ignition combustion including SI combustion performed by forcibly combusting a portion of mixture gas inside a cylinder 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 operating range of the engine, is provided. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, a memory configured to store a characteristic defining a relationship between a start timing of the CI combustion and a combustion noise index, and a processor configured to specify a given combustion noise index value based on the detection value of the detector, and control the start timing of the CI combustion.

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.