Abstract: An engine control device is provided, which includes an oxidation catalyst provided in an exhaust passage to oxidize unburned fuel within exhaust gas, a NOx catalyst provided integrally with or downstream of the oxidation catalyst, a PM filter provided in the exhaust passage downstream of the oxidation catalyst to capture fine particulate matter within the exhaust gas, a fuel injector, and a controller. When the particulate matter is accumulated by a given amount, the controller starts a PM filter regeneration control to remove the particulate matter, and after this control is started and when the accumulation amount decreases by a given amount, the controller starts a NOx catalyst regeneration control to switch between a first state in which an air-fuel ratio of the exhaust gas is a stoichiometric air-fuel ratio or less and a second state in which the air-fuel ratio is higher than the stoichiometric air-fuel ratio.

Abstract: An engine control device is provided, which includes an oxidation catalyst provided in an exhaust passage to oxidize unburned fuel within exhaust gas, a NOx catalyst provided integrally with or downstream of the oxidation catalyst, a PM filter provided in the exhaust passage downstream of the oxidation catalyst to capture fine particulate matter within the exhaust gas, a fuel injector, and a controller. When the particulate matter is accumulated by a given amount, the controller starts a PM filter regeneration control to remove the particulate matter, and after this control is started and when the accumulation amount decreases by a given amount, the controller starts a NOx catalyst regeneration control to switch between a first state in which an air-fuel ratio of the exhaust gas is a stoichiometric air-fuel ratio or less and a second state in which the air-fuel ratio is higher than the stoichiometric air-fuel ratio.

Abstract: An exhaust emission control system of an engine is provided, which includes a NOx catalyst disposed in an exhaust passage for storing NOx within exhaust gas when an air-fuel ratio of the exhaust gas is lean, and reducing the stored NOx when the air-fuel ratio is approximately stoichiometric or rich. A processor executes a NOx reduction controlling module for performing, when the NOx stored amount exceeds a given amount, a NOx reduction control in which a fuel injector performs a post injection of fuel to continuously control the air-fuel ratio to a target ratio so that the stored NOx is reduced to be below a given amount, the target air-fuel ratio being a ratio at which the stored NOx is reducible, the post injection causing the injected fuel to combust inside a cylinder, the execution of the control permitted when an engine load is within a medium load range.

Abstract: An exhaust emission control system of an engine is provided, which includes a NOx catalyst disposed in an exhaust passage for storing NOx within exhaust gas when an air-fuel ratio of the exhaust gas is lean, and reducing the stored NOx when the air-fuel ratio is approximately stoichiometric or rich. A processor executes a NOx reduction controlling module for performing, when the NOx stored amount exceeds a given amount, a NOx reduction control in which a fuel injector performs a post injection of fuel to continuously control the air-fuel ratio to a target ratio so that the stored NOx is reduced to be below a given amount, the target air-fuel ratio being a ratio at which the stored NOx is reducible, the post injection causing the injected fuel to combust inside a cylinder, the execution of the control permitted when an engine load is within a medium load range.

Abstract: This disclosure provides a method of controlling a diesel engine, which includes executing a premix combustion pattern fuel injection containing one or more injections at a first timing, while introducing an amount of EGR gas according to an operating condition of the engine into a cylinder, when an engine load is low, to operate in a premix combustion mode, executing a diffusion combustion pattern fuel injection containing one or more injections at a second timing that is later than the first timing, when the engine load is high, to operate in a diffusion combustion mode, and executing a diffusion combustion pattern fuel injection at a third timing that is later than the second timing, while introducing the amount of EGR gas according to the operating condition of the engine into the cylinder, when shifting from the diffusion combustion mode to the premix combustion mode with a decrease in engine load.

Abstract: This disclosure provides a method of controlling a diesel engine, which includes executing a premix combustion pattern fuel injection containing one or more injections at a first timing, while introducing an amount of EGR gas according to an operating condition of the engine into a cylinder, when an engine load is low, to operate in a premix combustion mode, executing a diffusion combustion pattern fuel injection containing one or more injections at a second timing that is later than the first timing, when the engine load is high, to operate in a diffusion combustion mode, and executing a diffusion combustion pattern fuel injection at a third timing that is later than the second timing, while introducing the amount of EGR gas according to the operating condition of the engine into the cylinder, when shifting from the diffusion combustion mode to the premix combustion mode with a decrease in engine load.

Abstract: To suppress deposition of fuel injected at an early timing on a wall surface for preventing the degradation in fuel efficiency and increase in the amount of harmful components in an exhaust gas, in a direct-injection diesel engine which controls the injector to cause a combustion configuration dominated by the compressive ignition of the premixture while the engine is in the premixed combustion region defined on a low load side. When fuel is injected at an early timing to form the premixture, at least one of the pulse width to be inputted into the injector and the fuel pressure is or are adjusted according to the change in the injection timing, and corrected according to the intake air temperature or the intake pressure. If an allowable pulse width is insufficient to inject fuel in the amount corresponding to a target torque, fuel is injected in a divided manner.

Abstract: To optimize an ignition timing of premixture for improving fuel efficiency regardless of significant change in an EGR ratio or a fluctuation in temperature of recirculated exhaust gas and temperature in a combustion chamber, there is provided a control apparatus for a diesel engine which controls an injector extending into the combustion chamber to execute a main-injection for injecting fuel and increasing the EGR ratio, so as to attain the premixed compressive ignition combustion while the engine is in the premixed combustion region on the low load side. Just before or after a cool flame reaction occurs in the mixture formed by the main-injection, an auxiliary-injection is executed so that the latent heat of vaporization of the fuel decreases the temperature of the mixture to delay the ignition to a timing near TDC. The auxiliary-injection amount is adjusted according to the estimated value of EGR ratio or the change in the crank angular velocity to optimize the ignition timing of the mixture.

Abstract: To optimize an ignition timing of premixture for improving fuel efficiency regardless of significant change in an EGR ratio or a fluctuation in temperature of recirculated exhaust gas and temperature in a combustion chamber, there is provided a control apparatus for a diesel engine which controls an injector extending into the combustion chamber to execute a main-injection for injecting fuel and increasing the EGR ratio, so as to attain the premixed compressive ignition combustion while the engine is in the premixed combustion region on the low load side. Just before or after a cool flame reaction occurs in the mixture formed by the main-injection, an auxiliary-injection is executed so that the latent heat of vaporization of the fuel decreases the temperature of the mixture to delay the ignition to a timing near TDC. The auxiliary-injection amount is adjusted according to the estimated value of EGR ratio or the change in the crank angular velocity to optimize the ignition timing of the mixture.

Abstract: To suppress deposition of fuel injected at an early timing on a wall surface for preventing the degradation in fuel efficiency and increase in the amount of harmful components in an exhaust gas, in a direct-injection diesel engine which controls the injector to cause a combustion configuration dominated by the compressive ignition of the premixture while the engine is in the premixed combustion region defined on a low load side. When fuel is injected at an early timing to form the premixture, at least one of the pulse width to be inputted into the injector and the fuel pressure is or are adjusted according to the change in the injection timing, and corrected according to the intake air temperature or the intake pressure. If an allowable pulse width is insufficient to inject fuel in the amount corresponding to a target torque, fuel is injected in a divided manner.