Abstract: An engine control device is provided. A fuel injection valve performs a pre-injection and a main injection on a retarding side of the pre-injection so that pressure waves resulting from combustions caused by the injections cancel each other out. The control device secures a fuel injection amount to be supplied to a combustion chamber in one cycle by at least the pre-injection, the main injection, and a middle injection. The control device causes the fuel injection valve to perform the pre-injection at a timing when a piston is located at an advancing side of compression top dead center for premix combustion, to start the main injection during a combustion period of the fuel injected by the pre-injection for diffuse combustion, and to perform the middle injection at a timing between the other two injections with a fuel injection amount less than the other injections.

Abstract: A control device for a compression ignition engine is provided, which causes an injector to perform a pre-injection and a main injection, sets fuel injection timings of these injections so that an interval between a first peak of a heat release rate resulting from the combustion of fuel injected by the pre-injection and a second peak of the heat release rate resulting from the combustion of fuel injected by the main injection becomes an interval to make pressure waves caused by these combustions cancel each other out, and when an increase of an intake air temperature is detected, controls the injector to reduce the injection amount of the pre-injection and retard the injection timing of the pre-injection compared with a case where the increase of the intake air temperature is not detected under a condition that engine load and speed are the same.

Abstract: A control device for a compression ignition engine is provided, which causes an injector to perform a pre-injection and a main injection, sets fuel injection timings of these injections so that an interval between a first peak of a heat release rate resulting from the combustion of fuel injected by the pre-injection and a second peak of the heat release rate resulting from the combustion of fuel injected by the main injection becomes an interval to make pressure waves caused by these combustions cancel each other out, and when an increase of a wall surface temperature of a combustion chamber is detected, controls the injector to reduce the injection amount and retard the injection timing of the pre-injection compared with a case where the temperature increase is not detected, under a condition that engine load and speed are the same.

Abstract: A control device for an engine is provided. A cavity formed in a crown surface of a piston of the engine includes a first cavity part disposed in a radially center area, a second cavity part disposed radially outward of the first cavity part, and a connecting part connecting these two parts. The control device causes a fuel injection valve to perform a first injection in which fuel is injected at a timing when the piston is located at an advancing side of CTDC and an injection axis thereof intersects with the connecting part, a second injection in which fuel is injected toward the first cavity part at a retarding side of the first injection, and a middle injection in which fuel is injected at a timing between the first and second injections, for a period shorter than each of the first and second injections.

Abstract: A control device for a compression ignition engine is provided, which causes an injector to perform a pre-injection and a main injection, sets fuel injection timings of these injections so that an interval between a first peak of a heat release rate resulting from the combustion of fuel injected by the pre-injection and a second peak of the heat release rate resulting from the combustion of fuel injected by the main injection becomes an interval to make pressure waves caused by these combustions cancel each other out, and when an increase of an oxygen concentration of intake air supplied to a combustion chamber is detected, controls the injector to reduce the injection amount and retard the injection timing of the pre-injection compared with a case where the concentration increase is not detected under a condition that engine load and speed are the same.

Abstract: A control device for a compression ignition engine is provided, which causes an injector to perform a pre-injection and a main injection, sets fuel injection timings of these injections so that an interval between a first peak of a heat release rate resulting from the combustion of fuel injected by the pre-injection and a second peak of the heat release rate resulting from the combustion of fuel injected by the main injection becomes an interval to make pressure waves caused by these combustions cancel each other out, and when an increase of a wall surface temperature of a combustion chamber is detected, controls the injector to reduce the injection amount and retard the injection timing of the pre-injection compared with a case where the temperature increase is not detected, under a condition that engine load and speed are the same.

Abstract: A control device for a compression ignition engine is provided, which causes an injector to perform a pre-injection and a main injection, sets fuel injection timings of these injections so that an interval between a first peak of a heat release rate resulting from the combustion of fuel injected by the pre-injection and a second peak of the heat release rate resulting from the combustion of fuel injected by the main injection becomes an interval to make pressure waves caused by these combustions cancel each other out, and when an increase of an intake air temperature is detected, controls the injector to reduce the injection amount of the pre-injection and retard the injection timing of the pre-injection compared with a case where the increase of the intake air temperature is not detected under a condition that engine load and speed are the same.

Abstract: A control device for a compression ignition engine is provided, which causes an injector to perform a pre-injection and a main injection, sets fuel injection timings of these injections so that an interval between a first peak of a heat release rate resulting from the combustion of fuel injected by the pre-injection and a second peak of the heat release rate resulting from the combustion of fuel injected by the main injection becomes an interval to make pressure waves caused by these combustions cancel each other out, and when an increase of an oxygen concentration of intake air supplied to a combustion chamber is detected, controls the injector to reduce the injection amount and retard the injection timing of the pre-injection compared with a case where the concentration increase is not detected under a condition that engine load and speed are the same.

Abstract: A control device for an engine is provided. A cavity formed in a crown surface of a piston of the engine includes a first cavity part disposed in a radially center area, a second cavity part disposed radially outward of the first cavity part, and a connecting part connecting these two parts. The control device causes a fuel injection valve to perform a first injection in which fuel is injected at a timing when the piston is located at an advancing side of CTDC and an injection axis thereof intersects with the connecting part, a second injection in which fuel is injected toward the first cavity part at a retarding side of the first injection, and a middle injection in which fuel is injected at a timing between the first and second injections, for a period shorter than each of the first and second injections.

Abstract: An engine control device is provided. A fuel injection valve performs a pre-injection and a main injection on a retarding side of the pre-injection so that pressure waves resulting from combustions caused by the injections cancel each other out. The control device secures a fuel injection amount to be supplied to a combustion chamber in one cycle by at least the pre-injection, the main injection, and a middle injection. The control device causes the fuel injection valve to perform the pre-injection at a timing when a piston is located at an advancing side of compression top dead center for premix combustion, to start the main injection during a combustion period of the fuel injected by the pre-injection for diffuse combustion, and to perform the middle injection at a timing between the other two injections with a fuel injection amount less than the other injections.

Abstract: A control system of an engine is provided, which includes a piston formed with a cavity and configured to reciprocate in a cylinder along a center axis of the cylinder, and a fuel injector disposed facing a top surface of the piston and configured to inject fuel along an injection axis. When the piston is located near a top dead center of compression stroke, the fuel injector performs a first injection so that the fuel flows from the fuel injector toward the cavity along the injection axis, collides with an inner surface of the cavity, then flows back toward the fuel injector along the inner surface of the cavity from a position offset from the injection axis. The fuel injector performs a second injection toward the cavity at a timing after the first injection and at which the fuel of the first injection flows back.

Abstract: The control device that controls fuel injection of a diesel engine includes a split injection control module that causes a fuel injection valve to execute pre-injection and post-injection, a setting module that sets a fuel injection amount or a fuel injection timing in the pre-injection so that a target heat release rate characteristic, by which a ratio between a first peak and a second peak, which are peaks of an increase rate of combustion pressure accompanying the pre- and post-injection, becomes a target value set in advance, can be obtained, a prediction module that predicts an occurrence time or a peak value of the first peak based on the injection amount or injection timing and a parameter related to a combustion environmental factor, and a correction module that corrects the fuel injection amount or the fuel injection timing set by the setting module.

Abstract: A control system that controls fuel injection of a diesel engine includes a split injection control module that causes a fuel injection valve to execute pre-injection for injecting fuel at a predetermined first timing, and post-injection for injecting fuel at a second timing later than the pre-injection, a setting module that sets a fuel injection amount or a fuel injection timing in the pre-injection or the post-injection so that a difference between a first peak and a second peak, which are peaks of an increase rate of combustion pressure accompanying the pre- and post-injection, falls within a predetermined range, and a calculation module that calculates the first and second peaks in an increase rate of the combustion pressure by excluding motoring pressure, which is an in-cylinder pressure at the time of non-combustion of the combustion chamber.

Abstract: A control system of an engine is provided, which includes a piston formed with a cavity and configured to reciprocate in a cylinder along a center axis of the cylinder, and a fuel injector disposed facing a top surface of the piston and configured to inject fuel along an injection axis. When the piston is located near a top dead center of compression stroke, the fuel injector performs a first injection so that the fuel flows from the fuel injector toward the cavity along the injection axis, collides with an inner surface of the cavity, then flows back toward the fuel injector along the inner surface of the cavity from a position offset from the injection axis. The fuel injector performs a second injection toward the cavity at a timing after the first injection and at which the fuel of the first injection flows back.

Abstract: A diesel engine of the present invention includes a turbocharger including: a turbine provided on an exhaust passage; a compressor provided on an intake passage; and a plurality of nozzle vanes provided around the turbine to control a flow velocity of an exhaust gas colliding with the turbine, angles of the nozzle vanes being changeable. In a case where a ratio of a volume of a combustion chamber when the intake valve is closed to a volume of the combustion chamber when a piston is located at a top dead center is denoted by an effective compression ratio ?e, and a total displacement of the engine is denoted by V (L), the effective compression ratio ?e is set to satisfy Formula (1) “?0.67×V+15.2??e?14.8.

Abstract: The disclosure provides a diesel engine, which includes an engine body mounted in a vehicle and having a cylinder to be supplied with fuel containing diesel fuel as its main component, a geometric compression ratio ? of the cylinder being set within a range of 12:1 to 15:1, and an EGR system for allowing a part of burned gas to exist inside of the engine body cylinder when the engine body is at least in a particular operating state where an engine load and an engine speed are relatively low. The EGR system includes an EGR passage at least partially formed inside the engine body, and having a predetermined or shorter passage, an EGR control valve provided in a course of the EGR passage and for adjusting a flow rate of the burned gas inside the EGR passage, and a controller for controlling an opening of the EGR control valve.

Abstract: This disclosure provides a method of controlling a diesel engine. The method includes adjusting an EGR ratio according to an engine load so that a cylinder O2 concentration decreases gradually to a predetermined load with an increase in the load of the engine, while the O2 concentration increases gradually above the predetermined load, operating the engine in a premix combustion mode where the fuel injection is terminated before a top dead center of a compression stroke in a low load operating range including the predetermined load where the O2 concentration is lowest and, after that, the fuel ignites and combusts, and operating in a diffusion combustion mode where the fuel injection is executed in parallel to the ignition and combustion of the fuel in an operating range where the load is higher than that of the operating range in the premix combustion mode and the O2 concentration is relatively high.

Abstract: This disclosure provides a control device for a diesel engine. When the engine is within a particular operating range with a low engine speed and a partial engine load and in a low temperature state where a cylinder temperature at a compression stroke end is lower than a predetermined temperature, a forced induction system sets a forcibly inducting level higher than a predetermined level that is higher than that in a high temperature state where the cylinder temperature is above the predetermined temperature. At least within the particular operating range, an injection control module performs a main injection where a fuel injection starts at or before a top dead center of the compression stroke to cause main combustion mainly including diffusion combustion and performs a pre-stage injection where the fuel injection is performed at least once prior to the main injection to cause pre-stage combustion before the main combustion starts.

Abstract: A diesel engine body is provided with a geometric compression ratio ? within a range of 12:1 to 15:1. The engine body has an intake valve for opening and closing an intake passage of a cylinder, an exhaust valve for opening and closing an exhaust passage of the cylinder, and an exhaust gas re-circulation passage communicating with the intake and exhaust passages and for partially re-circulating exhaust to the intake passage. During low engine load and rotation speed conditions, the exhaust valve is opened during an intake stroke, and the intake passage is choked. The exhaust valve is closed before the intake valve in the later stage of the intake stroke. An opening area SE of the exhaust valve is set so that a ratio of SE to an opening area SI of the intake valve meets a relation of: 0.01×(15??)+0.02?SE/SI?0.17.

Abstract: The disclosure provides a diesel engine, which includes an engine body mounted in a vehicle and having a cylinder to be supplied with fuel containing diesel fuel as its main component, a geometric compression ratio ? of the cylinder being set within a range of 12:1 to 15:1, and an EGR system for allowing a part of burned gas to exist inside of the engine body cylinder when the engine body is at least in a particular operating state where an engine load and an engine speed are relatively low. The EGR system includes an EGR passage at least partially formed inside the engine body, and having a predetermined or shorter passage, an EGR control valve provided in a course of the EGR passage and for adjusting a flow rate of the burned gas inside the EGR passage, and a controller for controlling an opening of the EGR control valve.