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: 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 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: A control apparatus for an internal combustion engine having an air flow control valve which changes intake air flow achieves the stratified lean combustion, in place of the homogeneous lean combustion, in a specific combustion stroke of a specific cylinder, when it switches the opening of the air flow control valve, if all of or a part of a specific intake stroke overlaps with a switching period of the air flow control valve, the specific combustion stroke following the specific intake stroke of the specific cylinder. As a result, even when the opening of the air flow control valve is changed, it is possible to make combustion stable. Thereby, the occurrence of torque fluctuation is suppressed.

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: 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 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 EGR apparatus includes a EGR passage and an EGR valve provided in the EGR passage to regulate an EGR flow rate in the EGR passage. An ECU closes the EGR valve from an open state prior to start of deceleration of the engine based on engine rotation speed detected by a rotation speed sensor, accelerator opening degree detected by an accelerator sensor, and actual opening degree of the EGR valve. During deceleration of the engine, the ECU obtains a target opening degree of the EGR valve according to the separately detected engine rotation speed and accelerator opening degree from a target opening degree map and starts to close the EGR valve when a difference between an actual opening degree and the target opening degree of the EGR valve exceeds a predetermined value.

Abstract: A control apparatus for an internal combustion engine having an air flow control valve which changes intake air flow achieves the stratified lean combustion, in place of the homogeneous lean combustion, in a specific combustion stroke of a specific cylinder, when it switches the opening of the air flow control valve, if all of or a part of a specific intake stroke overlaps with a switching period of the air flow control valve, the specific combustion stroke following the specific intake stroke of the specific cylinder. As a result, even when the opening of the air flow control valve is changed, it is possible to make combustion stable. Thereby, the occurance of torque fluctuation is suppressed.

Abstract: An exhaust circulation apparatus that can improve fuel combustion and suppress discharged NOx by expanding an operating region in which homogeneous lean combustion is possible. The exhaust circulation apparatus includes a homogeneous lean combustion unit for performing homogeneous lean combustion in a predetermined lean-burn region, and an EGR apparatus for performing EGR that recirculates a portion of gas that flows through an exhaust system of the internal combustion engine to an intake system. When performing homogeneous lean combustion, the exhaust circulation apparatus controls the EGR apparatus to perform EGR. An LPL-EGR apparatus that recirculates gas flowing through an exhaust passage on a downstream side of a turbine to an intake passage on an upstream side of a compressor is used as the EGR apparatus. Preferably, an air-fuel ratio is controlled so as to be 22:1 and an EGR rate is controlled so as to be between 10% and 20%.

Abstract: The control device executes transition control when the operating state of the air flow control valve is switched during implementation of the lean burn operation, and the NOx storage amount which is estimated is smaller than a determination value. According to the transition control, a combustion air-fuel ratio in a cycle of which an intake stroke overlaps a time period of switching the operating state of the air flow control valve is made fuel-leaner than the theoretical air-fuel ratio and fuel-richer than the predetermined air-fuel ratio. When the estimated value of the NOx storage amount is the determination value or more, rich spike is executed during a predetermined time period including the time period of switching the operating state of the air flow control valve.

Abstract: An amount of NOx discharged from an internal combustion engine at the time of reducing the NOx stored in an NOx storage reduction catalyst is decreased.

Abstract: An amount of NOx discharged from an internal combustion engine at the time of reducing the NOx stored in an NOx storage reduction catalyst is decreased.

Abstract: A spark plug includes a housing portion; an insulator that is retained in the housing portion; a center electrode that is exposed from the insulator; and a ground electrode that forms a discharge gap between the ground electrode and the center electrode. A plug pocket is formed between the housing portion and the insulator. In the spark plug, a tapered portion is provided on an inside of one of two portions of a tip end portion of the housing portion that face each other in a radial direction of the housing portion, and the ground electrode is provided on the other portion.

Abstract: An exhaust circulation apparatus that can improve fuel combustion and suppress discharged NOx by expanding an operating region in which homogeneous lean combustion is possible. The exhaust circulation apparatus includes a homogeneous lean combustion unit for performing homogeneous lean combustion in a predetermined lean-burn region, and an EGR apparatus for performing EGR that recirculates a portion of gas that flows through an exhaust system of the internal combustion engine to an intake system. When performing homogeneous lean combustion, the exhaust circulation apparatus controls the EGR apparatus to perform EGR. An LPL-EGR apparatus that recirculates gas flowing through an exhaust passage on a downstream side of a turbine to an intake passage on an upstream side of a compressor is used as the EGR apparatus. Preferably, an air-fuel ratio is controlled so as to be 22 and an EGR rate is controlled so as to be between 10% and 20%.

Abstract: The cooling device is provided with an engine including a cylinder block, a cylinder head, and a W/J which is a single system as a whole and which causes coolant to flow from the cylinder block to the cylinder head. The W/J branches into first and second inner paths within the cylinder block, and joints together within the cylinder head. The first inner path is provided with an opening and closing valve for permitting and prohibiting the flow of the coolant based on the pressure of the coolant.

Abstract: A cooling apparatus 1A includes an engine 50A having a cylinder head 52A having a head side W/J 521A equipped with partial W/J 521aA through 521dA individually incorporated into four different cooling systems, first recess/projection portions P capable of generating a flow separation of cooling water in accordance with a change of the flow rate within a range of a maximum flow rate of the cooling water being provided to the head side W/J 521A, and control means for executing a control of changing the flow rate of the cooling water that flows through the first cooling medium passageway in accordance with operating conditions of the engine including a case where the control means partially changes in each of the plurality of the partial cooling medium passageways.

Abstract: An EGR apparatus includes a EGR passage and an EGR valve provided in the EGR passage to regulate an EGR flow rate in the EGR passage. An ECU closes the EGR valve from an open state prior to start of deceleration of the engine based on engine rotation speed detected by a rotation speed sensor, accelerator opening degree detected by an accelerator sensor, and actual opening degree of the EGR valve. During deceleration of the engine, the ECU obtains a target opening degree of the EGR valve according to the separately detected engine rotation speed and accelerator opening degree from a target opening degree map and starts to close the EGR valve when a difference between an actual opening degree and the target opening degree of the EGR valve exceeds a predetermined value.

Abstract: A cooling device 1A includes an engine 50A provided with W/Js 501, 502, and 503A, and a first control valve 31. The W/J 501 is provided at an intake side in a cylinder block 51A. The W/J 502 is provided at an exhaust side in the cylinder block 51A. The W/J 503A diverges from a given position of the W/J 501. Also, the W/J 503A is provided toward the exhaust side through the intake side of the cylinder head 52A. The first control valve 31 makes the coolant flowing state changeable between a state where the coolant is caused to flow in the W/J 501 and a state where the coolant is caused to flow in the W/Js 501 and 503A.

Abstract: In an internal combustion engine, on a cylinder head side, a tumble flow is formed that is directed from an intake vent opened on the cylinder head to an exhaust vent opened on the cylinder head. A direct injection valve injects fuel directly into a combustion space. The direct injection valve injects the fuel toward a section where a piston top surface intersects with a cylinder inner surface, at a point closer to an intake top dead center than a middle between the intake top dead center and an intake bottom dead center, and thereafter injects the fuel into the combustion space again.