Abstract: A diesel engine system has a piston in which a cavity is formed in a crown surface. The cavity has a bottom part, a peripheral part dented so as to be convex radially outward in a cross-sectional view, and a lip part formed above the peripheral part and protruding so as to be convex radially inward in the cross-sectional view. An injection controller causes an injector to perform, during operation in a given operating range, a main injection in which injected fuel is directed to the lip part, and an after-injection in which a smaller amount of fuel than the main injection is injected at a given period later than the main injection in an expansion stroke. An injection interval period that is a period of time from an end of the main injection to a start of the after-injection is shorter as an injection pressure of fuel increases.

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 diesel engine system has a piston in which a cavity is formed in a crown surface. The cavity has a bottom part, a peripheral part dented so as to be convex radially outward in a cross-sectional view, and a lip part formed above the peripheral part and protruding so as to be convex radially inward in the cross-sectional view. An injection controller causes an injector to perform, during operation in a given operating range, a main injection in which injected fuel is directed to the lip part, and an after-injection in which a smaller amount of fuel than the main injection is injected at a given period later than the main injection in an expansion stroke. An injection interval period that is a period of time from an end of the main injection to a start of the after-injection is shorter as an injection pressure of fuel increases.

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 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 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: 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.