Abstract: An internal combustion engine comprising: an intake opening; an exhaust opening; and a mask part having a wall surface extending toward the inside of the combustion chamber along an outer periphery of the intake opening at an opposite side from the exhaust opening side. The wall surface of the mask part is formed so that a clearance from a passage surface of an edge part of the intake valve at an edge part at the lift direction side is greater than the clearance at the edge part at the opposite lift direction side, and so that between the edge part at the lift direction side and the edge part at the opposite lift direction side, the clearance is a value between the clearance at the edge part at the lift direction side and the clearance at the edge part at the opposite lift direction side.

Abstract: An internal combustion engine includes a plurality of cylinders, and these cylinders are divided into a first group where the air-fuel mixture is burned in the entire operating region and a second group where the air-fuel mixture is not burned in part of the operating region. The engine comprising: an intake opening opened and closed by an intake valve; an exhaust opening opened and closed by an exhaust valve; and a mask part having a wall surface extending along an outer edge of the intake opening toward the inside of the combustion chamber at an opposite side from the exhaust opening side. The mask part is configured so that a clearance from a passage surface of an edge part of the intake valve to the wall surface of the mask part is smaller at each cylinder of the first group than each cylinder of the second group.

Abstract: In a lean-burn engine equipped with a turbocharger, a responsiveness of a supercharging pressure in a lean region is enhanced by control of a valve timing of an exhaust valve while a combustion state is restrained from varying. A variable valve mechanism that can change an opening timing of the exhaust valve while keeping a closing timing of the exhaust valve constant, is included in the lean-burn engine. When a target operation point is located in the lean region, and when an actual supercharging pressure is lower than a target supercharging pressure, supercharging pressure increasing control that advances the opening timing while keeping the closing timing constant is executed by operating the variable valve mechanism.

Abstract: The control apparatus operates an engine water temperature adjustment apparatus so that the temperature of cooling water that passes through an engine head enters a first temperature region in a lean mode, and operates the engine water temperature adjustment apparatus so that the temperature of the cooling water enters a second temperature region that is lower than the first temperature region in a stoichiometric mode. When knocking is detected after switching is started from the lean mode to the stoichiometric mode, the control apparatus performs any one of a first operation to operate a variable valve apparatus so as to retard the closing timing of an intake valve, a second operation to operate an oil jet apparatus so as to increase an oil jet amount, and a third operation to operate an EGR apparatus so as to increase an EGR amount.

Abstract: An internal combustion engine includes two intake openings, opened and closed by intake valves; exhaust openings opened and closed by exhaust valves; a fuel injector having a plurality of nozzle holes; and mask parts having wall surfaces extending along outer edges of the intake openings toward the inside of the combustion chamber. The fuel injector arranged wherein the nozzle holes are positioned at the opposite exhaust opening sides from the intake openings, and the plurality of nozzle holes include a first nozzle hole, injecting in a direction with the smallest angle from a plane perpendicular to the axial direction of the cylinder. The wall surface formed wherein a height in a first nozzle hole ejection region positioned in a range of injection of a fuel spray from the first nozzle hole, when viewed in the axial direction, is lower than a height in the first nozzle hole ejection region.

Abstract: A controller for an internal combustion engine is configured, when the speed of combustion of a fuel in a cylinder changes as the property of the fuel injected from a fuel injection valve changes, to change a combustion limit excess air ratio that is a target value of a fuel injection amount feedforward control according to a first relationship that the combustion limit excess air ratio increases as the speed of combustion of the fuel in the cylinder increases. The controller is also configured, when the speed of combustion of the fuel in the cylinder changes as the property of the fuel injected from the fuel injection valve changes, to change the value of a combustion limit combustion speed parameter that is the target value of a fuel injection amount feedback control according to a second relationship that the speed of combustion of the fuel in the cylinder corresponding to a combustion limit increases as the speed of combustion of the fuel in the cylinder increases.

Abstract: The control apparatus operates an engine water temperature adjustment apparatus so that the temperature of cooling water that passes through an engine head enters a first temperature region in a lean mode, and operates the engine water temperature adjustment apparatus so that the temperature of the cooling water enters a second temperature region that is lower than the first temperature region in a stoichiometric mode. When knocking is detected after switching is started from the stoichiometric mode to the lean mode, the control apparatus performs any one of a first operation to operate a variable valve apparatus so as to retard the closing timing of an intake valve, a second operation to operate an oil jet apparatus so as to increase an oil jet amount, and a third operation to operate an EGR apparatus so as to increase an EGR amount.

Abstract: When switching an operation mode from a stoichiometric mode to a lean mode, a rich spike that supplies excessive fuel relative to a theoretical air-fuel ratio is executed. If the temperature of the SCR is greater than or equal to an upper limit temperature at a time of the switching, after execution of the rich spike, the switching to the lean mode is executed after executing transient control that makes the EGR rate higher than EGR rate in the lean mode and makes the in-cylinder air-fuel ratio an air-fuel ratio between the theoretical air-fuel ratio and the air-fuel ratio in the lean mode.

Abstract: Assume that a boundary on the air-fuel ration operation is changed from a boundary (i) to a boundary (ii). Then, after the boundary is changed, a high EGR operation region where a target EGR rate is set to a high value overlaps partially with a rich operation region. Therefore, when it is determined that the current operating point exists in the overlapped region, the target EGR rate is forcibly lowered. In addition, the boundary on a drive cam for an intake valve is changed from a boundary (I) to a boundary (II) thereby a region where a small cam is selected is enlarged.

Abstract: A control device for an internal combustion engine is provided. The internal combustion engine includes a cylinder, an in-cylinder pressure sensor, a fuel injection valve, and an alcohol concentration sensor. The control device includes an electronic control unit. The electronic control unit is configured to: carry out learning of fuel properties with the fuel injected from the fuel injection valve as a target; calculate a combustion speed parameter, showing a combustion speed, within the cylinder, of the fuel that is a learning target of the fuel properties, on a basis of the in-cylinder pressure; and determine that water is included in the fuel when the capacitance of the fuel detected by the alcohol concentration sensor is larger than a preset first threshold, and when the combustion speed of the fuel within the cylinder is smaller than a preset second threshold.

Abstract: An exhaust gas purification system of an internal combustion engine according to the present invention includes: processing means for executing at least one of a process of increasing an air-fuel ratio of an air-fuel mixture burned in the internal combustion engine and a process of increasing EGR gas recirculated by an EGR apparatus, when increasing a NO2 proportion in exhaust gas; and control means for controlling the processing means so that an increase in the air-fuel ratio becomes larger, and an increase in the EGR gas becomes smaller when a temperature of the exhaust gas purification apparatus is high as compared to when the temperature of the exhaust gas purification apparatus is low.

Abstract: An internal combustion engine includes an intake air temperature adjustment apparatus that adjusts the temperature of intake air, and a control apparatus that operates at least the intake air temperature adjustment apparatus. When the internal combustion engine operates in a stoichiometric EGR mode, the control apparatus operates the intake air temperature adjustment apparatus so that the temperature of intake air entering a combustion chamber enters a first temperature region. When the internal combustion engine operates in a lean mode, the control apparatus operates the intake air temperature adjustment apparatus so that the temperature of intake air entering a combustion chamber enters a second temperature region that is a lower temperature region than the first temperature region.

Abstract: An operating range boundary for switching a cam for driving an intake valve (drive cam) is changed in a direction of decreasing an engine load if a target EGR rate is predicted to increase across the contour line shown in FIG. 3. By changing the boundary, the drive cam is switched from a large cam to a small cam before an operating point is transferred from a partitioned range R2 to a partitioned range R1. When the small cam is selected as the drive cam, suction efficiency is frequently lowered as compared to a case where the large cam is selected as the drive cam. Therefore, the drive cam is switched to the small cam before the operating point is transferred from the partitioned range R2 to the partitioned range R1, thereby enabling the suction efficiency to be lowered in many cases.

Abstract: An electronic control unit is configured to select a first cam as a driving cam of an intake valve in a first operation range where a target value of an EGR rate is set to a specified EGR rate, and is configured to select a second cam as the driving cam in a second operation range smaller in valve duration and lift amount than the first cam. Accordingly, in most of the operation regions, the first cam is selected, and the second cam is selected only in a high-torque and high-speed region. When the second cam is selected in the high-torque and high-speed region, the state where an actual compression ratio is high can be eliminated, and suction efficiency can be decreased. Therefore, decrease in a knocking limit can be suppressed.

Abstract: A control device for an internal combustion engine is provided. The internal combustion engine includes a cylinder, an in-cylinder pressure sensor, a fuel injection valve, and an alcohol concentration sensor. The control device includes an electronic control unit. The electronic control unit is configured to: carry out learning of fuel properties with the fuel injected from the fuel injection valve as a target; calculate a combustion speed parameter, showing a combustion speed, within the cylinder, of the fuel that is a learning target of the fuel properties, on a basis of the in-cylinder pressure; and determine that water is included in the fuel when the capacitance of the fuel detected by the alcohol concentration sensor is larger than a preset first threshold, and when the combustion speed of the fuel within the cylinder is smaller than a preset second threshold.

Abstract: A controller for an internal combustion engine is configured, when the speed of combustion of a fuel in a cylinder changes as the property of the fuel injected from a fuel injection valve changes, to change a combustion limit excess air ratio that is a target value of a fuel injection amount feedforward control according to a first relationship that the combustion limit excess air ratio increases as the speed of combustion of the fuel in the cylinder increases. The controller is also configured, when the speed of combustion of the fuel in the cylinder changes as the property of the fuel injected from the fuel injection valve changes, to change the value of a combustion limit combustion speed parameter that is the target value of a fuel injection amount feedback control according to a second relationship that the speed of combustion of the fuel in the cylinder corresponding to a combustion limit increases as the speed of combustion of the fuel in the cylinder increases.

Abstract: In a lean-burn engine equipped with a turbocharger, a responsiveness of a super-charging pressure in a lean region is enhanced by control of a valve timing of an exhaust valve while a combustion state is restrained from varying. A variable valve mechanism that can change an opening timing of the exhaust valve while keeping a closing timing of the exhaust valve constant, is included in the lean-burn engine. When a target operation point is located in the lean region, and when an actual supercharging pressure is lower than a target supercharging pressure, supercharging pressure increasing control that advances the opening timing while keeping the closing timing constant is executed by operating the variable valve mechanism.

Abstract: A control device for an engine, the engine includes an exhaust gas control apparatus that is configured to store NOx and react NOx with a reduction agent. The control device includes an electronic control unit. The electronic control unit is configured to: (i) execute a rich spike control, the rich spike control is a control executed to temporarily change an in-cylinder air-fuel ratio from a leaner air-fuel ratio than the stoichiometric air-fuel ratio to the stoichiometric air-fuel ratio or a richer air-fuel ratio than the stoichiometric air-fuel ratio, and (ii) vary an overlap amount of an intake valve and an exhaust valve such that the overlap amount is less during non-execution of the rich spike control than during execution of the rich spike control, in an operation range where a pressure of the intake port becomes higher than a pressure of the exhaust port.

Abstract: A controller for an internal combustion engine is provided. The engine includes a compressor, a three way catalyst, a canister, an evaporated fuel passage, an ejector, and a purge control valve. The controller includes an ECU. The ECU is configured to decrease an opening degree of the purge control valve in response to an increase in pressure on the downstream side of the compressor in a lean supercharging range. The is a range in which an operation air-fuel ratio of the internal combustion engine is leaner than a theoretical air-fuel ratio of the internal combustion engine, and in which the pressure on the downstream side of the compressor is higher than pressure on the upstream side of the compressor.

Abstract: When an internal combustion engine operates in a stoichiometric mode, a control apparatus operates a cooling system so that the temperature of intake air becomes 45° C. When the internal combustion engine operates in a lean mode, the control apparatus operates the cooling system so that the temperature of intake air becomes 35° C. Also, the control apparatus calculates a crank angle period from an ignition timing until a crank angle at which a mass fraction burned becomes 10% and adjusts a fuel injection amount so that the SA-CA10 coincides with a target SA-CA10. Then, the control apparatus sets the target SA-CA10 short immediately after switching from the stoichiometric mode to the lean mode and extends the target SA-CA10 in accordance with a decrease in the temperature of intake air.