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 control device of a compression-ignition engine is provided. The control device includes the engine having a cylinder, an exhaust gas recirculation system for introducing exhaust gas into the cylinder, and a controller for operating the engine by compression-ignition combustion of mixture gas inside the cylinder within a predetermined compression-ignitable range on a low engine load side. Within the compression-ignitable range, the controller sets an EGR ratio higher as the engine load becomes lower, and the controller sets the EGR ratio to a predetermined highest EGR ratio when the engine load is at a specific load that is on the low engine load side within the compression-ignitable range. When the engine load is lower than the specific load, the controller sets the EGR ratio to be lower than the highest EGR ratio.

Abstract: A direct injection engine includes an ignition assistance section applying energy to fuel injected into a cylinder using an injector to assist auto-ignition combustion of the fuel when the engine is within an auto-ignition combustion operation range. A start time of fuel injection is set within a period from a terminal stage of a compression stroke to a compression top dead center. The energy is applied to the fuel injected into the cylinder in a period from start of the fuel injection to an initial stage of an expansion stroke such that a time of a specific crank angle when an increase rate of in-cylinder pressure, which is a ratio of a change in the in-cylinder pressure to a change in a crank angle in motoring the engine, reaches a negative maximum value overlaps a combustion period when a combustion mass percentage of the fuel ranges from 10% to 90%.

Abstract: A controller performs switching between a compression ignition mode in which compression ignition combustion is performed to operate an engine body, and a spark ignition mode in which spark ignition combustion is performed to drive a spark plug to ignite and combust an air-fuel mixture in a cylinder. The controller reduces an EGR ratio to be lower than an EGR ratio set in the compression ignition mode to operate the engine body in a transitional mode in which the compression ignition combustion is performed in switching from the spark ignition mode to the compression ignition mode.

Abstract: Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine, and a supercharger which supercharges air into the combustion chamber. One example method comprises, injecting fuel into the combustion chamber multiple times so that a first part of the fuel is self ignited and a last part of the fuel being injected during the compression stroke or later in a cylinder cycle when a desired torque of said internal combustion engine system is in a first range; and increasing a pressure of air which the supercharger charges into the combustion chamber as amount of fuel injected into the combustion chamber during a cylinder cycle increases when the desired torque is in the first range.

Abstract: When a catalytic converter in an exhaust passage is in an un-activated state, an intake air amount is increased, as compared to when the converter is in an activated state under the same engine operation condition, and an ignition timing is retarded beyond a TDC of a compression stroke. The ignition timing is set such that a retard amount thereof from the TDC becomes larger as an external load causing a rotational resistance of an engine becomes lower. A valve opening start timing of an exhaust valve is set such that, when the external load is lower than a given reference load, the valve starts opening, before an in-cylinder pressure reaches a peak, according to combustion of an air-fuel mixture ignited at the above ignition timing, in a subsequent expansion stroke, wherein the in-cylinder pressure is based on an assumption that the valve is maintained in a valve-closed state.

Abstract: A spark-ignition direct injection engine is provided. The engine includes an engine body, a fuel injection valve, a fuel pressure setting mechanism, an ignition plug, and a controller. Within a low engine speed operating range of a predetermined high engine load range, the fuel pressure setting mechanism sets a fuel pressure to 30 MPa or above, the fuel injection valve injects fuel between late stage of compression stroke and early stage of expansion stroke, and the ignition plug performs spark-ignition after the fuel injection completes. Within a high engine speed operating range of the high engine load range, the fuel injection valve injects fuel between intake stroke to mid-stage of compression stroke, and the ignition plug performs the spark-ignition. The ignition timing is changed according to an octane number, the changing width of the ignition timing is shorter within the low engine speed range than the high engine speed range.

Abstract: A controller performs switching between a compression ignition mode in which compression ignition combustion is performed to operate an engine body, and a spark ignition mode in which spark ignition combustion is performed to drive a spark plug to ignite and combust an air-fuel mixture in a cylinder. The controller reduces an EGR ratio to be lower than an EGR ratio set in the compression ignition mode to operate the engine body in a transitional mode in which the compression ignition combustion is performed in switching from the spark ignition mode to the compression ignition mode.

Abstract: A controller injects fuel into a cylinder at a high fuel pressure of 30 MPa or higher, at least in a period between a terminal stage of a compression stroke and an initial stage of an expansion stroke when an operating mode of an engine body is at least in a first specified sub-range of a low load range, and at least in a second specified sub-range of a high load range. The controller sets an EGR ratio in the first specified sub-range to be higher than an EGR ratio in the second specified sub-range, and advances start of fuel injection in the first specified sub-range to start of fuel injection in the second specified sub-range.

Abstract: A control device of a compression-ignition engine is provided. The device includes an engine having a cylinder, a fuel injection valve for injecting a fuel, an exhaust valve mechanism for switching an operation mode of an exhaust valve between a normal mode and an open-twice mode, a throttle valve disposed on an intake passage, and a controller for operating the engine by compression-ignition combustion of mixture gas inside the cylinder at least within a low engine load range. The controller suspends the fuel injection by the fuel injection valve when a predetermined fuel cut condition is met while the engine decelerates, and the controller fully closes the throttle valve and controls the exhaust valve mechanism to operate in the open-twice mode during the fuel cut. When a predetermined fuel resuming condition is met, the controller restarts the fuel injection, opens the throttle valve, and causes the compression-ignition combustion.

Abstract: A control device of a compression-ignition engine is provided. The control device includes the engine having a cylinder, an exhaust gas recirculation system for introducing exhaust gas into the cylinder, and a controller for operating the engine by compression-ignition combustion of mixture gas inside the cylinder within a predetermined compression-ignitable range on a low engine load side. Within the compression-ignitable range, the controller sets an EGR ratio higher as the engine load becomes lower, and the controller sets the EGR ratio to a predetermined highest EGR ratio when the engine load is at a specific load that is on the low engine load side within the compression-ignitable range. When the engine load is lower than the specific load, the controller sets the EGR ratio to be lower than the highest EGR ratio.

Abstract: A direct injection engine includes an ignition assistance section applying energy to fuel injected into a cylinder using an injector to assist auto-ignition combustion of the fuel when the engine is within an auto-ignition combustion operation range. A start time of fuel injection is set within a period from a terminal stage of a compression stroke to a compression top dead center. The energy is applied to the fuel injected into the cylinder in a period from start of the fuel injection to an initial stage of an expansion stroke such that a time of a specific crank angle when an increase rate of in-cylinder pressure, which is a ratio of a change in the in-cylinder pressure to a change in a crank angle in motoring the engine, reaches a negative maximum value overlaps a combustion period when a combustion mass percentage of the fuel ranges from 10% to 90%.

Abstract: A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body by using a coolant, and a controller for controlling a temperature of the coolant and changing the number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and expands the reduced-cylinder operating range to a higher engine load side as the coolant temperature becomes lower.

Abstract: A spark-ignition direct injection engine is provided. The engine includes an engine body, a fuel injection valve, a fuel pressure setting mechanism, an ignition plug, and a controller. The controller switches between a compression-ignition mode where the engine body is operated to perform compression-ignition combustion and a spark-ignition mode where the engine body is operated to perform spark-ignition combustion. Immediately after switching from the spark-ignition mode to the compression-ignition mode, the controller operates the engine body in a compression-ignition initial mode where the fuel pressure is set to be 30 MPa or above and the fuel injection valve is controlled to perform the fuel injection in a period from a late stage of the compression stroke to an early stage of the expansion stroke so that the gas mixture self-ignites to combust.

Abstract: A spark-ignition direct injection engine is provided. The engine includes an engine body, a fuel injection valve, a fuel pressure setting mechanism, an ignition plug, and a controller. Within a low engine speed operating range of a predetermined high engine load range, the fuel pressure setting mechanism sets a fuel pressure to 30 MPa or above, the fuel injection valve injects fuel between late stage of compression stroke and early stage of expansion stroke, and the ignition plug performs spark-ignition after the fuel injection completes. Within a high engine speed operating range of the high engine load range, the fuel injection valve injects fuel between intake stroke to mid-stage of compression stroke, and the ignition plug performs the spark-ignition. The ignition timing is changed according to an octane number, the changing width of the ignition timing is shorter within the low engine speed range than the high engine speed range.

Abstract: Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, and a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine. One example method comprises, when a desired torque for the internal combustion engine system is in a first range, injecting a first stage fuel into the combustion chamber so that it ends during a middle stage of a compression stroke at the latest in a cylinder cycle; determining combustion of the first stage fuel initiated by its compression self-ignition; and injecting a second stage fuel into the combustion chamber in a period when the determined combustion of the first stage fuel continues at a timing determined so as to cause combustion of the second stage fuel with its compression self-ignition.

Abstract: Disclosed is a supercharged direct-injection engine, which comprises a supercharging device (25, 30) for compressing intake air, and an injector 10 for directly injecting fuel into a combustion chamber 5. In the engine, an excess air factor ? as a ratio of an actual air-fuel ratio to a stoichiometric air-fuel ratio, at least in an engine warmed-up mode, is set to 2 or more in the entire engine-load region. Further, compressed self-ignited combustion is performed in a low engine-load region, and a supercharging amount by the supercharging device (25, 30) is increased along with an increase in engine load in a high engine-load region to allow the excess air factor ? to be kept at 2 or more. The engine of the present invention can effectively reduce NOx emission, while improving fuel economy.

Abstract: There is provided, in one aspect of the present description, a method of controlling a spark ignited internal combustion engine having a fuel injector which injects fuel directly into its combustion chamber. The method comprises stopping the fuel injection if a desired torque for the engine is a predetermined torque or less and a speed of the engine is a predetermined speed or greater. The method comprises resuming the fuel injection by injecting a first amount of fuel directly into the combustion chamber during a negative pressure period and injecting a second amount of the fuel into the combustion chamber during an intake period. The method further includes resuming the fuel injection by injecting a third amount of the fuel directly into the combustion chamber during the negative pressure period and injecting a fourth amount of the fuel into the combustion chamber during the intake period.

Abstract: There is provided a method for starting a spark ignition engine having multiple cylinders. The method may comprise supplying air and fuel for restart into a first cylinder before said engine completely stops, and igniting the mixture of said air and said fuel in said first cylinder in response to an engine restart request, wherein said first cylinder is on an expansion stroke when said engine stops. The method may also include, after said piston in said first cylinder starts moving, injecting fuel into a second cylinder that is on a compression stroke when said engine stops, on a compression stroke where a piston of said second cylinder is moving in a direction opposite to an operative direction of said piston in said first cylinder.