Abstract: A controller is configured to control a vehicle that includes an internal combustion engine and an automatic transmission. The controller is configured to execute a shifting process that switches a gear ratio of the automatic transmission and a lean operation process that operates the internal combustion engine with an air-fuel ratio of the air-fuel mixture in a cylinder leaner than a stoichiometric air-fuel ratio. The controller is further configured to, when executing the shifting process during execution of the lean operation process, set an air-fuel ratio in a case in which the shifting process is being executed to a value closer to the stoichiometric air-fuel ratio than an air-fuel ratio in a case in which the shifting process is not being executed.

Abstract: A controller is configured to control a vehicle that includes an internal combustion engine and an automatic transmission. The controller is configured to execute a shifting process that switches a gear ratio of the automatic transmission and a lean operation process that operates the internal combustion engine with an air-fuel ratio of the air-fuel mixture in a cylinder leaner than a stoichiometric air-fuel ratio. The controller is further configured to, when executing the shifting process during execution of the lean operation process, set an air-fuel ratio in a case in which the shifting process is being executed to a value closer to the stoichiometric air-fuel ratio than an air-fuel ratio in a case in which the shifting process is not being executed.

Abstract: A controller executes a fuel introduction process when stopping combustion in a cylinder under a situation in which a crankshaft is rotating. The fuel introduction process causes a fuel injection valve to inject fuel and causes the fuel to flow out unburned from inside the cylinder to an exhaust passage. The opening degree of an exhaust gas recirculation valve at a point in time when a state in which the execution condition of the fuel introduction process is not satisfied is switched to a state in which the execution condition of the fuel introduction process is satisfied is a preliminary opening degree. During the execution of the fuel introduction process, the recirculation valve controlling section causes the opening degree of the exhaust gas recirculation valve to be smaller than the preliminary opening degree.

Abstract: A controller configured to control a hybrid vehicle includes a catalyst temperature increase control unit configured to execute a catalyst temperature increase control of increasing a temperature of a three-way catalyst device, a motoring control of rotating a crankshaft of an internal combustion engine with power of a motor in a state in which combustion of the internal combustion engine is stopped, and a fuel introduction process of introducing unburned air-fuel mixture into an exhaust passage by performing fuel injection in the internal combustion engine during the execution of the motoring control.

Abstract: A controller for an internal combustion engine includes a fuel introduction process of introducing an air-fuel mixture containing fuel injected by a fuel injection valve into an exhaust passage without burning the air-fuel mixture in a cylinder. The fuel introduction processor is configured to perform, during the execution of the fuel introduction process, a determination process of determining whether afterfire, in which the air-fuel mixture burns at an upstream side of a three-way catalyst device in the exhaust passage, has occurred and a stopping process of stopping the fuel introduction process when determining in the determination process that the afterfire has occurred.

Abstract: When a purge valve opens, a CPU calculates a purge concentration learning value based on an air-fuel ratio detected by an air-fuel ratio sensor. Additionally, under the condition that a temperature increase request of a three-way catalyst is generated, the CPU performs dither control that sets one of a plurality of cylinders as a rich combustion cylinder, which is richer than a theoretical air-fuel ratio, and the remaining cylinders as lean combustion cylinders, which are leaner than the theoretical air-fuel ratio. When the dither control is performed, the CPU forbids the update of the purge concentration learning value.

Abstract: A controller executes a fuel introduction process when stopping combustion in a cylinder under a situation in which a crankshaft is rotating. The fuel introduction process causes a fuel injection valve to inject fuel and causes the fuel to flow out unburned from inside the cylinder to an exhaust passage. The opening degree of an exhaust gas recirculation valve at a point in time when a state in which the execution condition of the fuel introduction process is not satisfied is switched to a state in which the execution condition of the fuel introduction process is satisfied is a preliminary opening degree. During the execution of the fuel introduction process, the recirculation valve controlling section causes the opening degree of the exhaust gas recirculation valve to be smaller than the preliminary opening degree.

Abstract: A controller for an internal combustion engine includes a processing circuit that performs a dither control process on condition that a temperature increase request of a catalyst is made. The processing circuit operates fuel injection valves so that during the dither control process, one or more cylinders are lean combustion cylinders in a first period and another one or more cylinders are rich combustion cylinders and so that the average value of an exhaust gas-fuel ratio is a target air-fuel ratio in a second period including the first period. The dither control process is restricted in a manner that, on condition that the rich process is performed, the degree of richening of the richest exhaust gas-fuel ratio of exhaust gas-fuel ratios in the cylinders is reduced.

Abstract: A controller executes a fuel introduction process when stopping combustion in a cylinder under a situation in which a crankshaft is rotating. The fuel introduction process causes a fuel injection valve to inject fuel and causes the fuel to flow out unburned from inside the cylinder to an exhaust passage. The opening degree of an exhaust gas recirculation valve at a point in time when a state in which the execution condition of the fuel introduction process is not satisfied is switched to a state in which the execution condition of the fuel introduction process is satisfied is a preliminary opening degree. During the execution of the fuel introduction process, the recirculation valve controlling section causes the opening degree of the exhaust gas recirculation valve to be smaller than the preliminary opening degree.

Abstract: A temperature estimation module applied to a control apparatus for an internal combustion engine is configured to execute a virtual temperature estimation process that estimates a virtual temperature, which is a temperature of an exhaust purifying device under an assumption that a dither control process is not executed, based on an operation point of the internal combustion engine during execution of the dither control process. The temperature estimation module is further configured to execute an actual temperature estimation process that estimates an actual temperature of the exhaust purifying device based on a difference between the air-fuel ratio of a rich combustion cylinder and the air-fuel ratio of a lean combustion cylinder and based on the operation point of the internal combustion engine during execution of the dither control process.

Abstract: A controller for an internal combustion engine is configured to execute a dither control process and an exhaust gas recirculation (EGR) control process. The dither control process includes, when a request to increase a temperature of a catalyst is made, operating the fuel injection valves corresponding to respective cylinders to control the air-fuel ratio in some of the cylinders to become lean and control the air-fuel ratio in other cylinders to become rich. The EGR control process includes operating an adjustment actuator to control an EGR rate. The EGR control process includes operating the adjustment actuator such that the EGR rate is lower when the dither control process is being executed than when the dither control process is not being executed.

Abstract: When stopping combustion in a cylinder under a situation in which the crankshaft of an internal combustion engine having an ignition device is rotating, a controller executes a fuel introduction process of injecting fuel from a fuel injection valve and introducing the fuel from inside the cylinder to the exhaust passage without burning the fuel. Also, the controller executes a storing process before starting the fuel introduction process. In the storing process, the controller stores oxygen in a three-way catalyst by executing a fuel cutoff process of stopping fuel injection of the fuel injection valve under a situation in which the crankshaft is rotating.

Abstract: A controller includes an air-fuel ratio control unit that calculates an air-fuel ratio F/B correction value and an air-fuel ratio learning value and corrects an amount of fuel supplied to each cylinder based on the air-fuel ratio F/B correction value FAF and the air-fuel ratio learning value KG. The controller further includes a dither control unit that executes dither control to adjust the amount of fuel supplied to each cylinder, corrected by the air-fuel ratio control unit, so that at least one of the cylinders is set to a rich combustion cylinder and at least a further one of the cylinders is set to a lean combustion cylinder. When the dither control is executed, the air-fuel ratio control unit prohibits execution of air-fuel ratio learning control and executes air-fuel ratio feedback control.

Abstract: A controller for an internal combustion engine includes processing circuitry that performs a dither control process on condition that a temperature increase request of a catalyst is made. The processing circuitry operates fuel injection valves so that during the dither control process, one or more cylinders are lean combustion cylinders in a first period and another one or more cylinders are rich combustion cylinders and so that the average value of an exhaust gas-fuel ratio is a target air-fuel ratio in a second period including the first period. The dither control process is restricted in a manner that, on condition that the rich process is performed, the degree of richening of the richest exhaust gas-fuel ratio of exhaust gas-fuel ratios in the cylinders is reduced.

Abstract: A controller for an internal combustion engine includes processing circuitry configured to execute: a dither control process of operating fuel injection valves to designate at least one of cylinders as a lean combustion cylinder, in which an air-fuel ratio is leaner than a stoichiometric air-fuel ratio, and to designate at least another one of the cylinders as a rich combustion cylinder, in which an air-fuel ratio is richer than the stoichiometric air-fuel ratio; and an idle-time limiting process of causing an absolute value of a difference between the air-fuel ratio in the lean combustion cylinder and the air-fuel ratio in the rich combustion cylinder to be smaller when the internal combustion engine is idling than when the internal combustion engine is not idling.

Abstract: A controller is configured to execute a dither control process of operating fuel injection valves such that at least one of cylinders is a lean combustion cylinder, in which the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, and at least another one of the cylinders is a rich combustion cylinder, in which the air-fuel ratio is richer than the stoichiometric air-fuel ratio, and a limiting process of limiting the dither control process such that the difference in the air-fuel ratio between the cylinders is smaller in a change period, in which a gear ratio of the multi-speed transmission is changed, than in periods except for the change period.

Abstract: A control device for an internal combustion engine includes an electronic control unit configured to perform dither control processing for controlling the fuel injection valve based on a requested injection amount such that a part of cylinders among a plurality of cylinders becomes a lean combustion cylinder and cylinders different from the part of cylinders among the cylinders become a rich combustion cylinder, and restriction processing for, in a case where the requested injection amount is equal to or greater than a first injection amount, making no restriction on the dither control processing, and in a case where the requested injection amount is within a second injection amount range of an injection amount smaller than the first injection amount, restricting the dither control processing to a side where a leaning degree of an air-fuel ratio of a cylinder having a leanest air-fuel ratio among the cylinders decreases.

Abstract: A controller executes a fuel introduction process when stopping combustion in a cylinder under a situation in which a crankshaft is rotating. The fuel introduction process causes a fuel injection valve to inject fuel and causes the fuel to flow out unburned from inside the cylinder to an exhaust passage. The opening degree of an exhaust gas recirculation valve at a point in time when a state in which the execution condition of the fuel introduction process is not satisfied is switched to a state in which the execution condition of the fuel introduction process is satisfied is a preliminary opening degree. During the execution of the fuel introduction process, the recirculation valve controlling section causes the opening degree of the exhaust gas recirculation valve to be smaller than the preliminary opening degree.

Abstract: When stopping combustion in a cylinder under a situation in which the crankshaft of an internal combustion engine having an ignition device is rotating, a controller executes a fuel introduction process of injecting fuel from a fuel injection valve and introducing the fuel from inside the cylinder to the exhaust passage without burning the fuel. Also, the controller executes a storing process before starting the fuel introduction process. In the storing process, the controller stores oxygen in a three-way catalyst by executing a fuel cutoff process of stopping fuel injection of the fuel injection valve under a situation in which the crankshaft is rotating.

Abstract: A controller configured to control a hybrid vehicle includes a catalyst temperature increase control unit configured to execute a catalyst temperature increase control of increasing a temperature of a three-way catalyst device, a motoring control of rotating a crankshaft of an internal combustion engine with power of a motor in a state in which combustion of the internal combustion engine is stopped, and a fuel introduction process of introducing unburned air-fuel mixture into an exhaust passage by performing fuel injection in the internal combustion engine during the execution of the motoring control.