Abstract: An engine system is provided, including a controller which controls devices of an engine at a given engine speed so that, when a demanded engine load is a first load, a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel is a first G/F and mixture gas inside the cylinder combusts by flame-propagation, when the demanded load is a second load (<the first load), the G/F is a second G/F (>the first G/F) and an injection center-of-gravity is at a timing such that the entire mixture gas combusts by CI combustion, and when the demanded load is between the first and second loads, the G/F is at a third G/F (between the first and second G/Fs) and the injection center-of-gravity is at a later timing such that at least part of the mixture gas combusts by the CI combustion.

Abstract: An engine system is provided, including a controller which estimates an intake-valve-closing temperature inside a cylinder. When an engine operates at a given speed and a demanded engine load is a first load or a second load (>the first load), the controller controls so that a mixture gas inside the cylinder combusts by compression ignition, and controls so that, at the first load, the entire mixture gas combusts by compression ignition when the intake-valve-closing temperature is above a first temperature, and at least part of the mixture gas combusts by flame propagation when the intake-valve-closing temperature is below the first temperature, whereas at the second load, the entire mixture gas combusts by compression ignition when the intake-valve-closing temperature is above a second temperature (<the first temperature), and at least part of the mixture gas combusts by flame propagation when the intake-valve-closing temperature is below the second temperature.

Abstract: An engine system is provided, including a controller which estimates a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel, and controls devices of an engine at a given engine speed so that, while a demanded engine load is a first load, at least part of a mixture gas inside the cylinder combusts by flame-propagation when the estimated G/F is below a first G/F, and the entire mixture gas combusts by compression ignition when the estimated G/F is above the first G/F, whereas while the demanded load is a second load (>the first load), at least part of the mixture gas combusts by flame-propagation when the estimated G/F is below a second G/F (<the first G/F), and the entire mixture gas combusts by compression ignition when the estimated G/F is above the second G/F.

Abstract: An engine system is provided, including a controller which controls devices of an engine at a given engine speed so that, when a demanded engine load is a first load, a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel is a first G/F and mixture gas inside the cylinder combusts by flame-propagation, when the demanded load is a second load (<the first load), the G/F is a second G/F (>the first G/F) and an injection center-of-gravity is at a timing such that the entire mixture gas combusts by CI combustion, and when the demanded load is between the first and second loads, the G/F is at a third G/F (between the first and second G/Fs) and the injection center-of-gravity is at a later timing such that at least part of the mixture gas combusts by the CI combustion.

Abstract: An engine system is provided, including a controller which estimates an intake-valve-closing temperature inside a cylinder. When an engine operates at a given speed and a demanded engine load is a first load or a second load (>the first load), the controller controls so that a mixture gas inside the cylinder combusts by compression ignition, and controls so that, at the first load, the entire mixture gas combusts by compression ignition when the intake-valve-closing temperature is above a first temperature, and at least part of the mixture gas combusts by flame propagation when the intake-valve-closing temperature is below the first temperature, whereas at the second load, the entire mixture gas combusts by compression ignition when the intake-valve-closing temperature is above a second temperature (<the first temperature), and at least part of the mixture gas combusts by flame propagation when the intake-valve-closing temperature is below the second temperature.

Abstract: An engine system is provided, including a controller which estimates a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel, and controls devices of an engine at a given engine speed so that, while a demanded engine load is a first load, at least part of a mixture gas inside the cylinder combusts by flame-propagation when the estimated G/F is below a first G/F, and the entire mixture gas combusts by compression ignition when the estimated G/F is above the first G/F, whereas while the demanded load is a second load (>the first load), at least part of the mixture gas combusts by flame-propagation when the estimated G/F is below a second G/F (<the first G/F), and the entire mixture gas combusts by compression ignition when the estimated G/F is above the second G/F.

Abstract: A control device for a compression self-ignition engine includes a fuel injection system and an injection controller. While the engine is operated by CI combustion under a given first condition, a first injection is carried out in which fuel is injected at a first timing in a compression stroke and at which the fuel goes toward a part radially outward of a cavity formed in a crown surface of a piston, and a second injection is suspended. While the engine is operated by the CI combustion under a second condition in which a temperature inside a combustion chamber at a close timing of an intake valve becomes lower than the first condition, at least the second injection is carried out in which the fuel is injected at a second timing later than the first timing in the compression stroke and at which the fuel goes toward the cavity.

Abstract: A control device for a compression self-ignition engine includes a fuel injection system and an injection controller. While the engine is operated by CI combustion under a given first condition, a first injection is carried out in which fuel is injected at a first timing in a compression stroke and at which the fuel goes toward a part radially outward of a cavity formed in a crown surface of a piston, and a second injection is suspended. While the engine is operated by the CI combustion under a second condition in which a temperature inside a combustion chamber at a close timing of an intake valve becomes lower than the first condition, at least the second injection is carried out in which the fuel is injected at a second timing later than the first timing in the compression stroke and at which the fuel goes toward the cavity.

Abstract: A compression ignition gasoline engine includes a fuel injection valve for injecting fuel containing gasoline as a main component into a cylinder; an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; an octane number determination unit for determining whether fuel injected from the fuel injection valve has a prescribed octane number; and a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion occurs within the cylinder. The combustion control unit controls the EGR device, in at least a partial load operating range in which HCCI combustion is performed, in such a way that the EGR rate increases, as compared with a case where fuel is determined to have a prescribed octane number, when fuel is determined not to have a prescribed octane number.

Abstract: A compression ignition gasoline engine includes a fuel injection valve for injecting fuel containing gasoline as a main component into a cylinder; an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; and a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion in which fuel injected from the fuel injection valve self-ignites within the cylinder occurs. The combustion control unit controls the EGR device, in at least a partial load operating range in which HCCI combustion is performed, in such a way that the EGR rate increases, as compared with a low load condition, in a high load condition in which G/F being a ratio between a total amount of gas and a fuel amount within the cylinder decreases.

Abstract: A compression ignition gasoline engine includes a fuel injection valve for injecting fuel containing gasoline as a main component into a cylinder; an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; an octane number determination unit for determining whether fuel injected from the fuel injection valve has a prescribed octane number; and a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion occurs within the cylinder. The combustion control unit controls the EGR device, in at least a partial load operating range in which HCCI combustion is performed, in such a way that the EGR rate increases, as compared with a case where fuel is determined to have a prescribed octane number, when fuel is determined not to have a prescribed octane number.

Abstract: A compression ignition gasoline engine includes a fuel injection valve for injecting fuel containing gasoline as a main component into a cylinder; an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; and a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion in which fuel injected from the fuel injection valve self-ignites within the cylinder occurs. The combustion control unit controls the EGR device, in at least a partial load operating range in which HCCI combustion is performed, in such a way that the EGR rate increases, as compared with a low load condition, in a high load condition in which G/F being a ratio between a total amount of gas and a fuel amount within the cylinder decreases.

Abstract: A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

Abstract: A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

Abstract: Injection of the fuel by the injector 43 creates a gas flow in the combustion chamber. The gas expands in a radial fashion from an axis of a cylinder toward a radial outside of the cylinder, and then flows from the radial outside along the cylinder head bottom face 221 toward the axis of the cylinder. The spark plug 41 has a gap positioned away from the axis of the cylinder toward the radial outside of the cylinder at a predetermined distance, and placed radially inwardly from a position opposite a rim of an opening of the cavity 242. A side electrode extends to be oriented in a direction perpendicular to the flow of the gas along the cylinder head bottom face. The gap has a center positioned near the cylinder head bottom face, and closer to an interior of a combustion chamber than to the cylinder head bottom face.

Abstract: A control device for a compression ignition engine includes a controller configured to operate an engine body by compression ignition combustion when the engine body operates in a compression ignition range. When the engine body operates in a low load range with a load lower than a predetermined load in the compression ignition range, the controller sets a time of fuel injection with the fuel injection valve in a first half of a compression stroke or earlier, and allows the ozonator to introduce the ozone into the cylinder. When the engine body operates in the low load range, the controller controls an ozone concentration to be lower at a higher speed than at a low speed.

Abstract: A control device of an engine is provided. The engine is operated at a high compression ratio, a geometric compression ratio of the engine being 14:1 or higher. The control device includes a fuel injection controller for controlling a fuel injector of the engine to start a fuel injection in a latter half of a compression stroke within an engine operating range where an engine speed is below a predetermined value and an engine load is above a predetermined value, and an ignition controller for controlling an ignition plug of the engine to retard an ignition timing when a timing for the fuel injection controller to start the fuel injection is on a retarding side of a predetermined timing, the ignition timing being retarded based on a retarding amount of the fuel injection start timing from the predetermined timing.

Abstract: A control device for a compression ignition engine includes a controller configured to operate an engine body by compression ignition combustion when the engine body operates in a predetermined compression ignition range. When the engine body operates in a predetermined high load range of the compression ignition range, the controller maximizes a filling amount of the cylinder using a gas state adjustment system, and lowers an EGR ratio so that the air-fuel mixture in the cylinder is lean with an excess air ratio ? higher than 1 in a lower speed range, and maximizes the filling amount of the cylinder, and increases the EGR ratio so that the air-fuel mixture in the cylinder has the excess air ratio ? of 1 or lower in a higher speed range than the lower speed range.

Abstract: Injection of the fuel by the injector 43 creates a gas flow in the combustion chamber. The gas expands in a radial fashion from an axis of a cylinder toward a radial outside of the cylinder, and then flows from the radial outside along the cylinder head bottom face 221 toward the axis of the cylinder. The spark plug 41 has a gap positioned away from the axis of the cylinder toward the radial outside of the cylinder at a predetermined distance, and placed radially inwardly from a position opposite a rim of an opening of the cavity 242. A side electrode extends to be oriented in a direction perpendicular to the flow of the gas along the cylinder head bottom face. The gap has a center positioned near the cylinder head bottom face, and closer to an interior of a combustion chamber than to the cylinder head bottom face.

Abstract: When a specific condition requiring a rise in exhaust gas temperature is satisfied, a required fuel amount to be injected from an injector (21) is injected in a split manner, such that the fuel injection is divided to: a main injection (X1) to be initiated a given period before a compression top dead center; an auxiliary injection (X2) to be initiated after initiation of auto-ignited combustion of an air-fuel mixture consisting of air and the fuel injected by the main injection (X1) and before an assumed peak timing (Pk?) of a heat release rate (RH) from the combustion based on the main injection (X1); and a post injection (X3) to be initiated after the assumed peak timing (Pk?) and before completion of combustion based on the main injection (X1) and the auxiliary injection (X2). This makes it possible to raise an exhaust gas temperature while sufficiently ensuring auto-ignitability and fuel economy performance.