Abstract: A direct injection engine includes a fuel injection valve configured to inject fuel into a cylinder, a water injection valve configured to inject water into the cylinder, and a valve variable mechanism configured to change an operation timing of each of an intake valve and an exhaust valve. During an operation in a low load range, a negative overlap period when both of the intake valve and the exhaust valve are closed across an exhaust top dead center is formed by the valve variable mechanism, and fuel is injected from the fuel injection valve and water is injected from the water injection valve respectively during the negative overlap period. This causes a steam reforming reaction such that at least a part of injected fuel and injected water turns to hydrogen and carbon monoxide within the cylinder during the negative overlap period.

Abstract: A homogeneous charge compression ignition engine includes a cylinder configured to accommodate a piston to be reciprocally movable, a fuel injection valve configured to inject fuel into the cylinder, a water injection valve configured to inject water into the cylinder, a fuel injection control module configured to inject fuel from the fuel injection valve into the cylinder at such a timing that a mixture of fuel and air is self-ignited in a latter stage of a compression stroke or in an initial stage of an expansion stroke, and a water injection control module configured to perform at least a basic water injection of injecting water from the water injection valve into the cylinder during a predetermined period, which starts concurrently with or after start of combustion by the self-ignition and which overlaps a combustion period.

Abstract: A control system of an engine including a cylinder and a fuel injector, the fuel mixing with air to form a mixture gas and combusting inside the cylinder is provided, which includes a water injector for injecting supercritical water or subcritical water into the cylinder, and a controller. Within a high engine speed operating range, the controller controls the water injector to inject the one of supercritical water and subcritical water into the cylinder for a given period including a top dead center of the cylinder on compression stroke, such that when an injection amount of the one of supercritical water and subcritical water reaches half of a given injection amount, a crank angle of the engine corresponds to a retarding side of the top dead center, the given injection amount being a total amount of the supercritical water or subcritical water injected for the given period.

Abstract: A control system of an engine including a cylinder, an intake passage, and an exhaust passage is provided, that includes a fuel injector for injecting fuel into the cylinder, an exhaust gas recirculation (EGR) passage communicating the intake passage with the exhaust passage and for recirculating, as EGR gas, a portion of exhaust gas in the exhaust passage back to the cylinder, an EGR valve capable of controlling an EGR ratio by changing an EGR gas amount recirculated to the cylinder, a water injector for injecting water into the cylinder, and a controller. The controller controls the EGR valve to set a target EGR ratio according to an engine operating state so as to bring an actual EGR ratio to the target EGR ratio, and when the target EGR ratio is increased, the controller controls the water injector to increase an amount of the water injected into the cylinder.

Abstract: A control apparatus of an engine including a cylinder into which a piston is reciprocatably fitted is provided. The apparatus includes a fuel injector, a water injector, and a controller. The controller includes an engine load determining module for receiving a parameter and determining whether an engine operating range is within a low high load range or a high load range. Within the low load range, the controller controls the fuel injector to inject fuel into a center region of a combustion chamber. Within the high load range, the controller controls the fuel injector to inject the fuel in a period between a latter half of compression stroke and an early half of expansion stroke, and the water injector to inject supercritical water or subcritical water toward a crown surface of the piston in a period that is after the injection and before a mixture gas ignition.

Abstract: An engine system is provided that includes a cylinder, an exhaust flow part, a purifying system, a water injector for injecting supercritical/subcritical water into the cylinder, a water supply passage connected with the water injector and for supplying the water, a first temperature increasing device disposed at a position of the exhaust flow part and for increasing a water temperature, and a second temperature increasing device including a part of the exhaust flow part and a part of the water supply passage, and for increasing a water temperature. The first device increases the water temperature when an exhaust gas temperature passing through the position of the exhaust flow part exceeds a reference temperature. The second device increases the water temperature when an exhaust gas temperature passing through the part of the exhaust flow part is above a water temperature passing the part of the water supply passage.

Abstract: A direct injection engine includes a fuel injection valve configured to inject fuel into a cylinder, a water injection valve configured to inject water into the cylinder, and a valve variable mechanism configured to change an operation timing of each of an intake valve and an exhaust valve. During an operation in a low load range, a negative overlap period when both of the intake valve and the exhaust valve are closed across an exhaust top dead center is formed by the valve variable mechanism, and fuel is injected from the fuel injection valve and water is injected from the water injection valve respectively during the negative overlap period. This causes a steam reforming reaction such that at least a part of injected fuel and injected water turns to hydrogen and carbon monoxide within the cylinder during the negative overlap period.

Abstract: A homogeneous charge compression ignition engine includes a cylinder configured to accommodate a piston to be reciprocally movable, a fuel injection valve configured to inject fuel into the cylinder, a water injection valve configured to inject water into the cylinder, a fuel injection control module configured to inject fuel from the fuel injection valve into the cylinder at such a timing that a mixture of fuel and air is self-ignited in a latter stage of a compression stroke or in an initial stage of an expansion stroke, and a water injection control module configured to perform at least a basic water injection of injecting water from the water injection valve into the cylinder during a predetermined period, which starts concurrently with or after start of combustion by the self-ignition and which overlaps a combustion period.

Abstract: An engine has an engine body, an injector, and a control section which controls a fuel injection amount and an injection state of the injector. The control section predicts a state of temperature in the combustion chamber, and controls the injector such that a volume of an air-fuel mixture layer formed in the combustion chamber is larger when the predicted temperature is high, than when the predicted temperature is low, even when same fuel amounts are injected.

Abstract: A control apparatus of a premixed charge compression ignition engine that includes an engine body having a cylinder and intake and exhaust passages, and causes a mixture gas to self-ignite inside the cylinder is provided. The apparatus includes a fuel injector for injecting fuel into the cylinder, a water injector for injecting supercritical water or subcritical water into the cylinder, an EGR passage for communicating the exhaust and intake passages and recirculating, as EGR gas, a portion of an exhaust gas discharged from the cylinder to the intake passage, an EGR valve for adjusting an EGR gas recirculation amount, and a controller. The controller includes an engine load determining module for receiving a parameter and determining whether an engine operating state is a first state where the engine load is below a switch load or a second state where the engine load is the switch load or above.

Abstract: A control system of an engine including a cylinder and a fuel injector, the fuel mixing with air to form a mixture gas and combusting inside the cylinder is provided, which includes a water injector for injecting supercritical water or subcritical water into the cylinder, and a controller. Within a high engine speed operating range, the controller controls the water injector to inject the one of supercritical water and subcritical water into the cylinder for a given period including a top dead center of the cylinder on compression stroke, such that when an injection amount of the one of supercritical water and subcritical water reaches half of a given injection amount, a crank angle of the engine corresponds to a retarding side of the top dead center, the given injection amount being a total amount of the supercritical water or subcritical water injected for the given period.

Abstract: An engine system is provided that includes a cylinder, an exhaust flow part, a purifying system, a water injector for injecting supercritical/subcritical water into the cylinder, a water supply passage connected with the water injector and for supplying the water, a first temperature increasing device disposed at a position of the exhaust flow part and for increasing a water temperature, and a second temperature increasing device including a part of the exhaust flow part and a part of the water supply passage, and for increasing a water temperature. The first device increases the water temperature when an exhaust gas temperature passing through the position of the exhaust flow part exceeds a reference temperature. The second device increases the water temperature when an exhaust gas temperature passing through the part of the exhaust flow part is above a water temperature passing the part of the water supply passage.

Abstract: A control system of an engine including a cylinder, an intake passage, and an exhaust passage is provided, that includes a fuel injector for injecting fuel into the cylinder, an exhaust gas recirculation (EGR) passage communicating the intake passage with the exhaust passage and for recirculating, as EGR gas, a portion of exhaust gas in the exhaust passage back to the cylinder, an EGR valve capable of controlling an EGR ratio by changing an EGR gas amount recirculated to the cylinder, a water injector for injecting water into the cylinder, and a controller. The controller controls the EGR valve to set a target EGR ratio according to an engine operating state so as to bring an actual EGR ratio to the target EGR ratio, and when the target EGR ratio is increased, the controller controls the water injector to increase an amount of the water injected into the cylinder.

Abstract: A gasoline direct-injection engine is provided. The engine performs compression self-ignition combustion, and includes a cylinder, an injector, intake and exhaust ports, intake and exhaust valves, and an ozone generating system for generating ozone inside the cylinder. The system includes an electrode projecting into the cylinder while being partially electrically insulated from walls of the cylinder, and a high-voltage control device for applying a controlled pulse-shaped voltage to the electrode. When the voltage is applied, electric discharge occurs between the non-insulated part of the electrode and the walls of the cylinder, and ozone is generated inside the cylinder due to an effect of the electric discharge. A combustion pattern is provided, in which a compression stroke injection is performed and mixture gas formed by the fuel injection self-ignites to combust. When the combustion pattern is applied, the high-voltage control device is operated on intake stroke or the compression stroke.

Abstract: A control device of a gasoline direct-injection engine is provided. The control device includes an engine body, an injector, and a controller. Within a high load operating range, the controller causes the injector to perform a pre-injection and a post injection. In the pre-injection, the fuel is injected to cause a fuel concentration within an in-cylinder radially peripheral section to be higher than a fuel concentration within an in-cylinder radially central section at a timing for the fuel to ignite. In the post injection, the fuel is injected to cause the fuel concentration within the radially central section to be higher than the fuel concentration within the radially peripheral section at a timing for the fuel to ignite. The timing for the fuel injected in the post injection to ignite is after an oxidative reaction of the fuel injected in the pre-injection occurs and after a compression top dead center.

Abstract: A control apparatus of an engine including a cylinder into which a piston is reciprocatably fitted is provided. The apparatus includes a fuel injector for injecting fuel into the cylinder, a water injector for injecting supercritical or subcritical water into the cylinder, and a controller. The controller includes an operating range determining module for receiving a parameter and determining whether an engine operating range is within a water injection range. Within the water injection range, the controller controls the fuel injector to inject a portion of the fuel on an intake stroke or in an early half of compression stroke, and the water injector to inject the water toward a piston crown surface in a period that is between a latter half of the compression stroke and an early half of expansion stroke, after the fuel injection, and before a mixture gas is ignited inside the cylinder.

Abstract: A control apparatus of a premixed charge compression ignition engine that includes an engine body having a cylinder and causes a mixture gas containing fuel and air to self-ignite inside the cylinder is provided. The apparatus includes a fuel injector for injecting the fuel into the cylinder, a water injector for injecting supercritical water or subcritical water into the cylinder, and a controller. The controller includes an operating range determining module for receiving a parameter and determining whether an operating range of the engine body is within a water injection range. Within the water injection range, the controller controls the fuel and water injectors to inject the supercritical water or subcritical water between a latter half of compression stroke and an early half of expansion stroke, and to start this injection at a timing that is after the fuel injection and before ignition of the mixture gas.

Abstract: A control apparatus of a premixed charge compression ignition engine that includes an engine body having a cylinder and intake and exhaust passages, and causes a mixture gas to self-ignite inside the cylinder is provided. The apparatus includes a fuel injector for injecting fuel into the cylinder, a water injector for injecting supercritical water or subcritical water into the cylinder, an EGR passage for communicating the exhaust and intake passages and recirculating, as EGR gas, a portion of an exhaust gas discharged from the cylinder to the intake passage, an EGR valve for adjusting an EGR gas recirculation amount, and a controller. The controller includes an engine load determining module for receiving a parameter and determining whether an engine operating state is a first state where the engine load is below a switch load or a second state where the engine load is the switch load or above.

Abstract: A control apparatus of an engine including a cylinder into which a piston is reciprocatably fitted is provided. The apparatus includes a fuel injector, a water injector, and a controller. The controller includes an engine load determining module for receiving a parameter and determining whether an engine operating range is within a low high load range or a high load range. Within the low load range, the controller controls the fuel injector to inject fuel into a center region of a combustion chamber. Within the high load range, the controller controls the fuel injector to inject the fuel in a period between a latter half of compression stroke and an early half of expansion stroke, and the water injector to inject supercritical water or subcritical water toward a crown surface of the piston in a period that is after the injection and before a mixture gas ignition.

Abstract: A gasoline direct-injection engine is provided. The engine causes a self-ignition of a fuel injected into a cylinder by an injector and at least containing gasoline. The engine includes a controller for controlling the fuel injection by the injector. A geometric compression ratio of the engine is 15:1 or higher. The controller causes the injector to perform a pre-injection for keeping a variation of an in-cylinder temperature after a compression top dead center within a predetermined temperature range by injecting an amount of the fuel that causes an oxidative reaction without resulting in a hot flame reaction. The controller causes the injector to perform a main injection for causing self-ignition combustion of the fuel after the compression top dead center while the variation of the in-cylinder temperature is kept within the predetermined temperature range, by injecting the fuel after the pre-injection.